The reaction of cellulose with water produces swelling and structural changes of the fibres, both effects being of crucial importance for the understanding of paper formation. It was investigated how the treatment of pulp with deep eutectic
solvents affects the swelling kinetics of the fibres. Unbleached kraft pulp was treated with three deep eutectic solvents containing choline chloride (ChCl) – ChCl:lactic acid (1:9), ChCl:oxalic acid (1:1) and ChCl:malic acid (1:1) – and with the system alanine:lactic acid (1:9). The rate and maximum swelling of the
pulp in water were determined using a modified monitoring unit for measuring swelling ability. Since paper swells extremely rapidly in water even at 23°C, this apparatus made it possible for the first time to obtain accurate rate data on the swelling of DES-delignified pulp in water.
Behaviors of Pulp During Delignification in Solutions of Deep Eutectic Solven...Michal Jablonsky
In this short communication, the degradation of cellulose for delignified pulp by deep eutectic solvents was evaluated. The pulp was delignified using different DES systems based on choline chloride and lactic acid (1:9), oxalic acid dehydrate (1:1), malic acid (1:1), and system alanine : lactic acid (1:9). This paper shows that cellulose degradation can be characterized in terms of the percentage degree of polymerization loss of cellulose. Among the investigated DES (Choline chloride:oxalic acid; choline chloride:malic acid; alanine:lactic acid; choline chloride:lactic acid), the most suitable seemed to be a treatment using the alanine:lactic acid system that provided a relatively low degradation of cellulose and high delignification efficiency for the removed of lignin from pulp.
This document provides an introduction to membrane distillation, including:
1. It describes four main membrane distillation configurations: direct contact, air gap, sweeping gas, and vacuum membrane distillation.
2. It discusses common membrane module designs including tubular and plate and frame modules.
3. It outlines common membrane materials for membrane distillation including polypropylene, polyvinylidene fluoride, and polytetrafluoroethylene in both hollow fiber and flat sheet configurations.
Utilization of waste paper sludge in construction industrySandeep Jain
This technical note is recapitulation of the work carried out by researchers round the globe on characterization of waste paper sludge based on physical, chemical and mineralogical properties, activation mechanisms, pozzolanic reactivity, reaction kinematics and durability; for its possible utilization in construction industry as supplementary cementitious material, mineral admixture, partial replacement of binders in concrete, raw material for clay brick manufacturing, production of ceramics, soil stabilization in road works, reduction in carbon-dioxide emission etc., in order to encash various socio-economic and environmental benefits.
Application of Paper Waste in Cement ConcreteIJERA Editor
This document summarizes a study on the use of paper waste as an additional material in concrete mixes. Four concrete mixes were prepared with 0%, 10%, 15%, and 20% paper waste. The compressive strength, density, water absorption, and slump of the mixes were determined and compared to a control mix. The results showed that mixes with 10% and 15% paper waste had slightly higher compressive strength and density compared to the control, while the 20% mix showed lower strength. Water absorption decreased with higher paper waste content. Inclusion of 10% paper waste also provided a cost savings over the control mix. The study concluded that up to 15% paper waste could be used without significantly affecting concrete properties.
This document discusses the development and evaluation of nanosuspensions to improve the solubility and bioavailability of poorly soluble drugs. It begins by explaining the challenges of oral delivery for class II and IV drugs in the Biopharmaceutical Classification System due to their poor solubility. Several techniques to overcome poor solubility are then reviewed, including particle size reduction through nanosuspension formation. The key methods of preparing nanosuspensions - media milling, high pressure homogenization, and homogenization in nonaqueous media - are described in detail. Media milling uses high shear forces to break down drug particles, while high pressure homogenization applies intense pressures. Homogenization in nonaqueous media avoids issues with water by using alternative
This document discusses the Hindustan Latex Limited (HLL) Lifecare company and its effluent treatment plant. HLL Lifecare operates two factories in Trivandrum, India - one in Peroorkada that produces condoms and one in Akkulam that produces other medical products. The effluent treatment plant at Peroorkada uses various tanks and processes like lime mixing, FeCl3 mixing, aeration, settling, and filtration to treat wastewater before recycling or disposal. Sludge from the treatment plant is dried on beds and could potentially be used to make bricks.
IRJET- A Study on Effect of Addition of Paper Waste on Shear Behavior of ...IRJET Journal
This document summarizes a study on the effect of adding paper waste to cohesive soil to improve its shear behavior. The study included:
1) Analyzing the properties of the soil through tests like sieve analysis, liquid limit, plastic limit, and specific gravity.
2) Classifying the soil based on its plasticity index using a plasticity chart.
3) Conducting unconfined compression tests on soil samples with 2.5% and 5% paper waste by weight to analyze the improvements in shear strength.
The results showed that adding randomly oriented paper strips to clayey soil enhanced its shear strength and stability, making it a viable, sustainable option for soil stabilization.
This document provides an overview of membrane distillation, including:
- A brief history noting its first proposal in 1967 in Greece and early research in India in the 1970s.
- An explanation of the basic principle of using a hydrophobic membrane to allow vapor transport but prevent liquid transport for distillation.
- A description of the main types of membrane modules and common membrane materials used.
- Details on the heat and mass transfer processes during membrane distillation and equations governing vapor flux.
- Advantages of membrane distillation like high rejection rates and low energy costs compared to disadvantages like low permeate flux.
- Potential applications in water purification and food industries.
- A conclusion that membrane
Behaviors of Pulp During Delignification in Solutions of Deep Eutectic Solven...Michal Jablonsky
In this short communication, the degradation of cellulose for delignified pulp by deep eutectic solvents was evaluated. The pulp was delignified using different DES systems based on choline chloride and lactic acid (1:9), oxalic acid dehydrate (1:1), malic acid (1:1), and system alanine : lactic acid (1:9). This paper shows that cellulose degradation can be characterized in terms of the percentage degree of polymerization loss of cellulose. Among the investigated DES (Choline chloride:oxalic acid; choline chloride:malic acid; alanine:lactic acid; choline chloride:lactic acid), the most suitable seemed to be a treatment using the alanine:lactic acid system that provided a relatively low degradation of cellulose and high delignification efficiency for the removed of lignin from pulp.
This document provides an introduction to membrane distillation, including:
1. It describes four main membrane distillation configurations: direct contact, air gap, sweeping gas, and vacuum membrane distillation.
2. It discusses common membrane module designs including tubular and plate and frame modules.
3. It outlines common membrane materials for membrane distillation including polypropylene, polyvinylidene fluoride, and polytetrafluoroethylene in both hollow fiber and flat sheet configurations.
Utilization of waste paper sludge in construction industrySandeep Jain
This technical note is recapitulation of the work carried out by researchers round the globe on characterization of waste paper sludge based on physical, chemical and mineralogical properties, activation mechanisms, pozzolanic reactivity, reaction kinematics and durability; for its possible utilization in construction industry as supplementary cementitious material, mineral admixture, partial replacement of binders in concrete, raw material for clay brick manufacturing, production of ceramics, soil stabilization in road works, reduction in carbon-dioxide emission etc., in order to encash various socio-economic and environmental benefits.
Application of Paper Waste in Cement ConcreteIJERA Editor
This document summarizes a study on the use of paper waste as an additional material in concrete mixes. Four concrete mixes were prepared with 0%, 10%, 15%, and 20% paper waste. The compressive strength, density, water absorption, and slump of the mixes were determined and compared to a control mix. The results showed that mixes with 10% and 15% paper waste had slightly higher compressive strength and density compared to the control, while the 20% mix showed lower strength. Water absorption decreased with higher paper waste content. Inclusion of 10% paper waste also provided a cost savings over the control mix. The study concluded that up to 15% paper waste could be used without significantly affecting concrete properties.
This document discusses the development and evaluation of nanosuspensions to improve the solubility and bioavailability of poorly soluble drugs. It begins by explaining the challenges of oral delivery for class II and IV drugs in the Biopharmaceutical Classification System due to their poor solubility. Several techniques to overcome poor solubility are then reviewed, including particle size reduction through nanosuspension formation. The key methods of preparing nanosuspensions - media milling, high pressure homogenization, and homogenization in nonaqueous media - are described in detail. Media milling uses high shear forces to break down drug particles, while high pressure homogenization applies intense pressures. Homogenization in nonaqueous media avoids issues with water by using alternative
This document discusses the Hindustan Latex Limited (HLL) Lifecare company and its effluent treatment plant. HLL Lifecare operates two factories in Trivandrum, India - one in Peroorkada that produces condoms and one in Akkulam that produces other medical products. The effluent treatment plant at Peroorkada uses various tanks and processes like lime mixing, FeCl3 mixing, aeration, settling, and filtration to treat wastewater before recycling or disposal. Sludge from the treatment plant is dried on beds and could potentially be used to make bricks.
IRJET- A Study on Effect of Addition of Paper Waste on Shear Behavior of ...IRJET Journal
This document summarizes a study on the effect of adding paper waste to cohesive soil to improve its shear behavior. The study included:
1) Analyzing the properties of the soil through tests like sieve analysis, liquid limit, plastic limit, and specific gravity.
2) Classifying the soil based on its plasticity index using a plasticity chart.
3) Conducting unconfined compression tests on soil samples with 2.5% and 5% paper waste by weight to analyze the improvements in shear strength.
The results showed that adding randomly oriented paper strips to clayey soil enhanced its shear strength and stability, making it a viable, sustainable option for soil stabilization.
This document provides an overview of membrane distillation, including:
- A brief history noting its first proposal in 1967 in Greece and early research in India in the 1970s.
- An explanation of the basic principle of using a hydrophobic membrane to allow vapor transport but prevent liquid transport for distillation.
- A description of the main types of membrane modules and common membrane materials used.
- Details on the heat and mass transfer processes during membrane distillation and equations governing vapor flux.
- Advantages of membrane distillation like high rejection rates and low energy costs compared to disadvantages like low permeate flux.
- Potential applications in water purification and food industries.
- A conclusion that membrane
The physio chemical and mineralogical properties of mbaduku clay and its suit...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
This document reviews advances in membrane distillation technology for water desalination and purification. It discusses the fundamental heat and mass transfer processes in membrane distillation, recent developments in membrane materials and module designs, as well as applications and economics. Key configurations of membrane distillation include direct contact, air gap, vacuum, and sweep gas membrane distillation. While membrane distillation was introduced in the 1960s, limitations in membrane technology and economics previously hindered widespread adoption; however, new membrane materials and improved understanding of mass and heat transfer principles have renewed interest in membrane distillation in recent decades.
This study examined the degradation of poly(lactic acid) (PLA) medical implants over time. PLA specimens were submerged in saline solution at body temperature to simulate degradation in the body. The degradation process occurred in four stages: (1) initial water diffusion with little property change, (2) constant degradation rate controlled by water concentration, (3) autocatalytic degradation resulting in property decline, and (4) mass loss and specimen disintegration. Testing methods measured properties like molecular weight, mass change, mechanical properties, crystallinity, and glass transition temperature to characterize each degradation stage. The goal was to better understand PLA degradation to inform development of resorbable medical implants.
Effect of ascorbic acid, ethanol and acetone on adhesion between the treated ...Reza Talebian
This study evaluated the effect of ascorbic acid, ethanol, and acetone on bond strength between fiber posts and composite resin cores. 24 fiber posts were treated with hydrogen peroxide and then one of the following: no treatment (control), 10% ascorbic acid, 70% ethanol, or 70% acetone. Composite cores were built up and sections were tested for bond strength. Acetone treatment produced the highest bond strength, followed by ethanol, ascorbic acid, and the control. All failures occurred at the interface. The authors concluded that ascorbic acid, ethanol, and acetone can increase bond strength after hydrogen peroxide treatment by neutralizing oxygen radicals, with acetone being most effective.
Self-healing dental polymer:mechanism and uses in dentistry.
This presentation discusses briefly the definition ,mechanism and uses of self-healing polymers in dentistry.
This document summarizes an article that appeared in a journal published by Elsevier. The attached copy is for the author's internal non-commercial use, including instruction and sharing with colleagues. Other uses like reproduction, distribution, selling or posting to websites are prohibited without permission. Authors are allowed to post their version of the article to their personal or institutional websites or repositories, with some restrictions on commercial use. The document provides a link to Elsevier's full copyright and archiving policies.
IRJET- Comparision of Mud Brick, Sand Mud Brick and Plastic Sand Mud BrickIRJET Journal
This document compares mud bricks, sand mud bricks, and plastic sand bricks. It summarizes research that produced plastic sand bricks by melting plastic waste and mixing it with sand at percentages of 5%, 10%, and 15%. The plastic sand bricks were then tested for compressive strength and water absorption. Testing found that compressive strength increased with higher percentages of plastic, and could potentially be further increased with the addition of super plasticizers. Producing plastic sand bricks in this way helps address the problem of plastic waste disposal while utilizing plastic as a construction material.
This document describes research on modifying cellulose nanocrystals (CNC) through surface chemical reactions to improve their dispersion and mechanical reinforcement properties when used in wood coatings. CNC was reacted with either alkyl quaternary ammonium bromides or acryloyl chloride to introduce new surface functional groups. The modified CNC showed better dispersion in aqueous acrylic coatings and conferred improved scratch resistance when incorporated into coatings applied to sugar maple wood, with abrasion test results indicating improvements of 24-38% over coatings containing unmodified CNC. Characterization of the modified CNC confirmed the introduction of new surface functionalities without significantly altering the CNC structure.
1) The document studies parameters that control abrasive water jet technology, including erosion and impact velocity for ductile and brittle materials.
2) It analyzes experimental data that found water pressure and nozzle traverse speed influence the smooth depth of surface cuts. Higher pressures and slower speeds produced smoother cuts.
3) Results showed that traverse speed and water pressure affect cut quality and smooth depth, with lower speeds and higher pressures producing better quality cuts and deeper smooth depths. Material properties also influence smoothness.
Functionalizing a dentin bonding resin to become bioactive (Tobias Tauböck)DrMarkHogan
OBJECTIVES: To investigate chemo-mechanical effects of incorporating alkaline bioactive glass nanoparticles into a light-curable dental resin matrix.
METHODS: An unfilled Bis-GMA/TEGDMA material was infiltrated with up to 20wt% of ultrafine SiO2-Na2O-CaO-P2O5-Bi2O3 particles. The unfilled and filled resins were investigated regarding their viscosity before setting and compared to commercially available materials. Set specimens were immersed for 21 days in phosphate buffered saline at 37°C. Water uptake, pH, Knoop hardness, and degree of conversion of freshly polymerized and stored samples were investigated. Resin surfaces were viewed and mapped in a scanning electron microscope for the formation of calcium phosphate (Ca/P) precipitates. In addition, Raman spectroscopy was performed. Numeric values were statistically compared (p<0.01).><0.01).><0.01) increased the degree of conversion after 21 days. Ca/P precipitates formed on specimens filled with 20wt% of the particles, while they were scarce on counterparts loaded with 10wt%, and absent on unfilled resin surfaces.
SIGNIFICANCE: The results of the current study show that a Bis-GMA-based resin can be functionalized using alkaline nanoparticles. A material with bioactive properties and similar hardness as the unfilled resin was obtained by incorporating 20wt% of ultrafine SiO2-Na2O-CaO-P2O5-Bi2O3 particles into the resin matrix.
Mechanical Properties of Concrete with Marine Sand as Partial Replacement of ...IJERA Editor
The process of depleting sources of natural aggregates challenges the production of technically and
environmentally adequate concrete. Alternative material from marine sources is good enough for the
replacement of fine aggregate in the concrete. The material was stockpiled in the open air and no washing,
drying or decontamination process was carried out. Physical and chemical properties of DMS material were
determined. All the materials used in the concrete were selected and tested as per the standard procedures of the
Indian standards. A unique design mix will be done based on the entire material test results. Different mixtures
were produced using DMS in different proportions from 15% to 100% as per the finalized trial of the design
mix. The concrete were submitted to compressive strength testsafter 7, 28 and 90 days of moist curing, as well
as flexure and splitting tensile strength tests for M-25 grade.
IRJET- CharactCharacteristic Study on Behaviour of Integral Crystalline Water...IRJET Journal
This document discusses the use of integral crystalline waterproofing concrete where cement is partially replaced with fly ash, GGBS, silica fume, or rice husk ash along with the addition of a crystalline waterproofing agent. Compressive strength tests were performed on concrete cubes at 7, 14, and 28 days that used each replacement material at different percentages along with 2% crystalline waterproofing agent. The results showed that concrete with 10% fly ash replacement and 2% crystalline waterproofing agent had the lowest 28-day compressive strength, while concrete with 20% GGBS replacement and 2% crystalline waterproofing agent had the highest 28-day compressive strength. In conclusion, the addition of crystalline
Crystal Growth and Studies of Dihydrogen Phosphates of Potassium and Ammonium...IJERA Editor
A nonlinear optical (NLO) material Potassium dihydrogen phosphates (KDP) and Ammonium dihydrogen
phosphates (ADP) are grown by slow evaporation solution growth technique. The FTIR studies confirm the
presence of the functional group in the grown crystal. The optical transmittance studies show that the crystal has
transparence in the entire visible and IR region. The thermal stability of the materials was assessed by TG/DTA
analysis. The mechanical stability of the grown crystals was analyzed by Vicker’s microhardness test. The
dielectric behavior of the crystals was tested by dielectric analysis. The second harmonic generation (SHG) of
KDP is confirmed by Kurtz and Perry powder technique using Nd: YAG laser.
Preparation and properties of calcium-silicate filled resins for dental restoration. Part I: Chemical-physical characterization and apatite-forming ability.
Profeta AC.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Effect Of Solvent Type On Microtensile Bond Strength Of TotalEtch One-Bottle ...iosrjce
IOSR Journal of Dental and Medical Sciences is one of the speciality Journal in Dental Science and Medical Science published by International Organization of Scientific Research (IOSR). The Journal publishes papers of the highest scientific merit and widest possible scope work in all areas related to medical and dental science. The Journal welcome review articles, leading medical and clinical research articles, technical notes, case reports and others.
Study the rheological and mechanical properties of pva cu cl2 by ultrasonicAlexander Decker
The document studies the rheological and mechanical properties of polyvinyl alcohol (PVA) solutions with the addition of copper (II) chloride (CuCl2). PVA solutions were prepared with varying amounts of CuCl2 added. Ultrasonic measurements were taken to analyze properties including density, viscosity, velocity, bulk modulus, compressibility, transmittance, absorption coefficient, and relaxation amplitude. The results showed that adding CuCl2 increased viscosity and absorption coefficient, which decreased velocity, bulk modulus, and transmittance. This is because more CuCl2 molecules in solution lead to greater attenuation of ultrasonic waves. Overall, the intermolecular interactions between PVA and CuCl2 influenced the rhe
Mechanical Properties of Pulp Delignified by Deep Eutectic SolventsMichal Jablonsky
Mechanical properties were evaluated for pulp delignified by four deep eutectic solvents (DES). The DES systems were based on choline chloride and lactic acid (1:9), oxalic acid:dihydrate (1:1), malic acid (1:1), and the system alanine:lactic acid (1:9). The results indicated that the type of DES system used influenced the delignified pulp's mechanical properties including tensile, burst and tear indexes, tensile length, and stiffness. The most suitable DES systems were choline chloride:malic acid (1:1) and alanine:lactic acid (1:9), which achieved the best aforementioned mechanical properties compared to the other DES systems. The weakest performance in the process of pulp delignification was the system with choline chloride and oxalic acid dihydrate (1:1).
Deep Eutectic Solvent Delignification: Impact of Initial LigninMichal Jablonsky
This study investigated the effect of initial lignin content in hardwood kraft pulps on pulp delignification using deep eutectic solvents (DESs). Pulps with different initial Kappa numbers were treated with four DES systems and oxygen delignification for comparison. The results showed that DES delignification decreased the Kappa number by 37.8-43.3% depending on the DES, with alanine:lactic acid being most efficient. DESs caused less degradation than oxygen delignification as shown by smaller decreases in viscosity and degree of polymerization. The pulp with higher initial lignin had a greater fraction of easily removed lignin fragments.
Delignification of pulp with two ternary deep eutectic solvents: Urea-acetami...Michal Jablonsky
Using deep eutectic solvents (DESs), which ones act as solvent systems, offer an interesting green alternative to conventional technology in materials science, especially in the biomass processing. There is lack of information dealing with the delignification and bleaching effect of DESs in broad-leaved fiber process. This work describes application of various DESs on unbleached pulp, to study the influence of dissolution of lignin and protection of cellulose in the delignification process. In this work, two ternary deep eutectic solvents (urea-acetamide-glycerol) in molar ratio 1 : 2 : 3 and (malic acid-proline-lactic acid) in molar ratio 1 : 2 : 4 were synthesized and their density was studied in a temperature range of 25 to 75 0 C. Unbleached pulp (Kappa 14) was treated with prepared ternary deep eutectic solvents. The treatment was carried out in a water bath at present temperature of 60 0 C and atmospheric pressure for 2 hours. Solubility tests of cellulose were performed using pure cellulose (Whatman paper) in the DESs reagents. In 50 mL glass bottles, 0.5 g of the respective component was added separately into 20 mL of DES reagent and then incubated at 60 0 C for 2 h. The samples were filtered through glass fiber filters and dried at 105 0 C to constant weight. The weight of dried residual solid components was calculated in order to evaluate the % solubility in the DES reagent. Density of urea-acetamide-glycerol (molar ratio 1 : 2 : 3) decreased with a temperature from 1,220 to 1,199 g/cm 3 and density of malic acid-proline-lactic acid (molar ratio 1 : 2 : 4) decreased from 1,292 to 1,220 g/cm 3. Application of DESs to the lignocellulosic matrix pulp does not resulted in a significant decrease of lignin content. Deep eutectic solvent (urea-acet-amide-glycerol) in molar ratio 1 : 2 : 3 removed 5,4 % and DES (malic acid-proline-lactic acid) in molar ratio 1 : 2 : 4 removed 1.4 % lignin from unbleached pulp. The solubility of cellulose in ternary deep eutectic solvents was zero. Results show that prepared ternary deep eutectic solvents are able to delignify the pulp. However, the efficiency of delignification is not comparable to that of oxygen delignification. At the same time, used deep eutectic solvents do not cause dissolution of cellulose in pulp fibers.
The physio chemical and mineralogical properties of mbaduku clay and its suit...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
This document reviews advances in membrane distillation technology for water desalination and purification. It discusses the fundamental heat and mass transfer processes in membrane distillation, recent developments in membrane materials and module designs, as well as applications and economics. Key configurations of membrane distillation include direct contact, air gap, vacuum, and sweep gas membrane distillation. While membrane distillation was introduced in the 1960s, limitations in membrane technology and economics previously hindered widespread adoption; however, new membrane materials and improved understanding of mass and heat transfer principles have renewed interest in membrane distillation in recent decades.
This study examined the degradation of poly(lactic acid) (PLA) medical implants over time. PLA specimens were submerged in saline solution at body temperature to simulate degradation in the body. The degradation process occurred in four stages: (1) initial water diffusion with little property change, (2) constant degradation rate controlled by water concentration, (3) autocatalytic degradation resulting in property decline, and (4) mass loss and specimen disintegration. Testing methods measured properties like molecular weight, mass change, mechanical properties, crystallinity, and glass transition temperature to characterize each degradation stage. The goal was to better understand PLA degradation to inform development of resorbable medical implants.
Effect of ascorbic acid, ethanol and acetone on adhesion between the treated ...Reza Talebian
This study evaluated the effect of ascorbic acid, ethanol, and acetone on bond strength between fiber posts and composite resin cores. 24 fiber posts were treated with hydrogen peroxide and then one of the following: no treatment (control), 10% ascorbic acid, 70% ethanol, or 70% acetone. Composite cores were built up and sections were tested for bond strength. Acetone treatment produced the highest bond strength, followed by ethanol, ascorbic acid, and the control. All failures occurred at the interface. The authors concluded that ascorbic acid, ethanol, and acetone can increase bond strength after hydrogen peroxide treatment by neutralizing oxygen radicals, with acetone being most effective.
Self-healing dental polymer:mechanism and uses in dentistry.
This presentation discusses briefly the definition ,mechanism and uses of self-healing polymers in dentistry.
This document summarizes an article that appeared in a journal published by Elsevier. The attached copy is for the author's internal non-commercial use, including instruction and sharing with colleagues. Other uses like reproduction, distribution, selling or posting to websites are prohibited without permission. Authors are allowed to post their version of the article to their personal or institutional websites or repositories, with some restrictions on commercial use. The document provides a link to Elsevier's full copyright and archiving policies.
IRJET- Comparision of Mud Brick, Sand Mud Brick and Plastic Sand Mud BrickIRJET Journal
This document compares mud bricks, sand mud bricks, and plastic sand bricks. It summarizes research that produced plastic sand bricks by melting plastic waste and mixing it with sand at percentages of 5%, 10%, and 15%. The plastic sand bricks were then tested for compressive strength and water absorption. Testing found that compressive strength increased with higher percentages of plastic, and could potentially be further increased with the addition of super plasticizers. Producing plastic sand bricks in this way helps address the problem of plastic waste disposal while utilizing plastic as a construction material.
This document describes research on modifying cellulose nanocrystals (CNC) through surface chemical reactions to improve their dispersion and mechanical reinforcement properties when used in wood coatings. CNC was reacted with either alkyl quaternary ammonium bromides or acryloyl chloride to introduce new surface functional groups. The modified CNC showed better dispersion in aqueous acrylic coatings and conferred improved scratch resistance when incorporated into coatings applied to sugar maple wood, with abrasion test results indicating improvements of 24-38% over coatings containing unmodified CNC. Characterization of the modified CNC confirmed the introduction of new surface functionalities without significantly altering the CNC structure.
1) The document studies parameters that control abrasive water jet technology, including erosion and impact velocity for ductile and brittle materials.
2) It analyzes experimental data that found water pressure and nozzle traverse speed influence the smooth depth of surface cuts. Higher pressures and slower speeds produced smoother cuts.
3) Results showed that traverse speed and water pressure affect cut quality and smooth depth, with lower speeds and higher pressures producing better quality cuts and deeper smooth depths. Material properties also influence smoothness.
Functionalizing a dentin bonding resin to become bioactive (Tobias Tauböck)DrMarkHogan
OBJECTIVES: To investigate chemo-mechanical effects of incorporating alkaline bioactive glass nanoparticles into a light-curable dental resin matrix.
METHODS: An unfilled Bis-GMA/TEGDMA material was infiltrated with up to 20wt% of ultrafine SiO2-Na2O-CaO-P2O5-Bi2O3 particles. The unfilled and filled resins were investigated regarding their viscosity before setting and compared to commercially available materials. Set specimens were immersed for 21 days in phosphate buffered saline at 37°C. Water uptake, pH, Knoop hardness, and degree of conversion of freshly polymerized and stored samples were investigated. Resin surfaces were viewed and mapped in a scanning electron microscope for the formation of calcium phosphate (Ca/P) precipitates. In addition, Raman spectroscopy was performed. Numeric values were statistically compared (p<0.01).><0.01).><0.01) increased the degree of conversion after 21 days. Ca/P precipitates formed on specimens filled with 20wt% of the particles, while they were scarce on counterparts loaded with 10wt%, and absent on unfilled resin surfaces.
SIGNIFICANCE: The results of the current study show that a Bis-GMA-based resin can be functionalized using alkaline nanoparticles. A material with bioactive properties and similar hardness as the unfilled resin was obtained by incorporating 20wt% of ultrafine SiO2-Na2O-CaO-P2O5-Bi2O3 particles into the resin matrix.
Mechanical Properties of Concrete with Marine Sand as Partial Replacement of ...IJERA Editor
The process of depleting sources of natural aggregates challenges the production of technically and
environmentally adequate concrete. Alternative material from marine sources is good enough for the
replacement of fine aggregate in the concrete. The material was stockpiled in the open air and no washing,
drying or decontamination process was carried out. Physical and chemical properties of DMS material were
determined. All the materials used in the concrete were selected and tested as per the standard procedures of the
Indian standards. A unique design mix will be done based on the entire material test results. Different mixtures
were produced using DMS in different proportions from 15% to 100% as per the finalized trial of the design
mix. The concrete were submitted to compressive strength testsafter 7, 28 and 90 days of moist curing, as well
as flexure and splitting tensile strength tests for M-25 grade.
IRJET- CharactCharacteristic Study on Behaviour of Integral Crystalline Water...IRJET Journal
This document discusses the use of integral crystalline waterproofing concrete where cement is partially replaced with fly ash, GGBS, silica fume, or rice husk ash along with the addition of a crystalline waterproofing agent. Compressive strength tests were performed on concrete cubes at 7, 14, and 28 days that used each replacement material at different percentages along with 2% crystalline waterproofing agent. The results showed that concrete with 10% fly ash replacement and 2% crystalline waterproofing agent had the lowest 28-day compressive strength, while concrete with 20% GGBS replacement and 2% crystalline waterproofing agent had the highest 28-day compressive strength. In conclusion, the addition of crystalline
Crystal Growth and Studies of Dihydrogen Phosphates of Potassium and Ammonium...IJERA Editor
A nonlinear optical (NLO) material Potassium dihydrogen phosphates (KDP) and Ammonium dihydrogen
phosphates (ADP) are grown by slow evaporation solution growth technique. The FTIR studies confirm the
presence of the functional group in the grown crystal. The optical transmittance studies show that the crystal has
transparence in the entire visible and IR region. The thermal stability of the materials was assessed by TG/DTA
analysis. The mechanical stability of the grown crystals was analyzed by Vicker’s microhardness test. The
dielectric behavior of the crystals was tested by dielectric analysis. The second harmonic generation (SHG) of
KDP is confirmed by Kurtz and Perry powder technique using Nd: YAG laser.
Preparation and properties of calcium-silicate filled resins for dental restoration. Part I: Chemical-physical characterization and apatite-forming ability.
Profeta AC.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Effect Of Solvent Type On Microtensile Bond Strength Of TotalEtch One-Bottle ...iosrjce
IOSR Journal of Dental and Medical Sciences is one of the speciality Journal in Dental Science and Medical Science published by International Organization of Scientific Research (IOSR). The Journal publishes papers of the highest scientific merit and widest possible scope work in all areas related to medical and dental science. The Journal welcome review articles, leading medical and clinical research articles, technical notes, case reports and others.
Study the rheological and mechanical properties of pva cu cl2 by ultrasonicAlexander Decker
The document studies the rheological and mechanical properties of polyvinyl alcohol (PVA) solutions with the addition of copper (II) chloride (CuCl2). PVA solutions were prepared with varying amounts of CuCl2 added. Ultrasonic measurements were taken to analyze properties including density, viscosity, velocity, bulk modulus, compressibility, transmittance, absorption coefficient, and relaxation amplitude. The results showed that adding CuCl2 increased viscosity and absorption coefficient, which decreased velocity, bulk modulus, and transmittance. This is because more CuCl2 molecules in solution lead to greater attenuation of ultrasonic waves. Overall, the intermolecular interactions between PVA and CuCl2 influenced the rhe
Mechanical Properties of Pulp Delignified by Deep Eutectic SolventsMichal Jablonsky
Mechanical properties were evaluated for pulp delignified by four deep eutectic solvents (DES). The DES systems were based on choline chloride and lactic acid (1:9), oxalic acid:dihydrate (1:1), malic acid (1:1), and the system alanine:lactic acid (1:9). The results indicated that the type of DES system used influenced the delignified pulp's mechanical properties including tensile, burst and tear indexes, tensile length, and stiffness. The most suitable DES systems were choline chloride:malic acid (1:1) and alanine:lactic acid (1:9), which achieved the best aforementioned mechanical properties compared to the other DES systems. The weakest performance in the process of pulp delignification was the system with choline chloride and oxalic acid dihydrate (1:1).
Deep Eutectic Solvent Delignification: Impact of Initial LigninMichal Jablonsky
This study investigated the effect of initial lignin content in hardwood kraft pulps on pulp delignification using deep eutectic solvents (DESs). Pulps with different initial Kappa numbers were treated with four DES systems and oxygen delignification for comparison. The results showed that DES delignification decreased the Kappa number by 37.8-43.3% depending on the DES, with alanine:lactic acid being most efficient. DESs caused less degradation than oxygen delignification as shown by smaller decreases in viscosity and degree of polymerization. The pulp with higher initial lignin had a greater fraction of easily removed lignin fragments.
Delignification of pulp with two ternary deep eutectic solvents: Urea-acetami...Michal Jablonsky
Using deep eutectic solvents (DESs), which ones act as solvent systems, offer an interesting green alternative to conventional technology in materials science, especially in the biomass processing. There is lack of information dealing with the delignification and bleaching effect of DESs in broad-leaved fiber process. This work describes application of various DESs on unbleached pulp, to study the influence of dissolution of lignin and protection of cellulose in the delignification process. In this work, two ternary deep eutectic solvents (urea-acetamide-glycerol) in molar ratio 1 : 2 : 3 and (malic acid-proline-lactic acid) in molar ratio 1 : 2 : 4 were synthesized and their density was studied in a temperature range of 25 to 75 0 C. Unbleached pulp (Kappa 14) was treated with prepared ternary deep eutectic solvents. The treatment was carried out in a water bath at present temperature of 60 0 C and atmospheric pressure for 2 hours. Solubility tests of cellulose were performed using pure cellulose (Whatman paper) in the DESs reagents. In 50 mL glass bottles, 0.5 g of the respective component was added separately into 20 mL of DES reagent and then incubated at 60 0 C for 2 h. The samples were filtered through glass fiber filters and dried at 105 0 C to constant weight. The weight of dried residual solid components was calculated in order to evaluate the % solubility in the DES reagent. Density of urea-acetamide-glycerol (molar ratio 1 : 2 : 3) decreased with a temperature from 1,220 to 1,199 g/cm 3 and density of malic acid-proline-lactic acid (molar ratio 1 : 2 : 4) decreased from 1,292 to 1,220 g/cm 3. Application of DESs to the lignocellulosic matrix pulp does not resulted in a significant decrease of lignin content. Deep eutectic solvent (urea-acet-amide-glycerol) in molar ratio 1 : 2 : 3 removed 5,4 % and DES (malic acid-proline-lactic acid) in molar ratio 1 : 2 : 4 removed 1.4 % lignin from unbleached pulp. The solubility of cellulose in ternary deep eutectic solvents was zero. Results show that prepared ternary deep eutectic solvents are able to delignify the pulp. However, the efficiency of delignification is not comparable to that of oxygen delignification. At the same time, used deep eutectic solvents do not cause dissolution of cellulose in pulp fibers.
Delignification of pulp using deep eutectic solventsMichal Jablonsky
Lot of works during the last decades have been focused on the new modes of pulp processing. One promising technology is the use of deep eutectic solvents. Deep eutectic solvents (DES) have opportunities to open new paths in the field of delignification methods. This study was conducted to investigate the effects of deep eutectic solvent treatment on physical and chemical properties of delignified pulp. In the following experiment we used as an initial pulp the kraft pulp (Kappa No. 21.7; Degree of polymerization 1157). The pulp was treated with two different DES system based on choline chloride with lactic acid (1 : 9), and system alanine : lactic acid (1 : 9). The efficiency of delignification expressed as a decrease in kappa number on the unit change of the initial kappa number of pulp. The order by the delignification efficiency growth is as follows: choline chloride : lactic acid (37.8%) > alanine : lactic acid (43.3%). During delignification by DESs, a degradation of pulp chain occurs, however a decrease in degree of polymerization was only 23 units versus kraft unbleached pulp, which represents maximum decrease by 2%. Delignified pulp with DESs has a brightness 34% and unbleached pulp achieved brightness 27%, therefore, it achieves the increase in brightness by 26%.The physical strength properties of DES delignified pulps were assessed in terms of tensile, tear and burst index and stiffness. Application of deep eutectic solvents were achieved to reduce tensile index by 13.2%, burst index by 14.3% and a tear index by 9.8%, and the pulp stiffness was increased by 4% again the unbleached pulp. The results indicate that application of DESs might be an interesting alternative to oxygen delignification of pulp following kraft cooks.
Remarkable self-organization and unusual conductivity behavior in cellulose n...Pawan Kumar
Aqueous suspensions of cellulose nanocrystals were blended with Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)
[PEDOT:PSS], and cast into thin films. The morphology, structure and electrical properties of the resulting nanocomposite
thin films were thoroughly characterized. We found that the CNC–PEDOT:PSS blends self-organize into a layered vertical
stack with a pitch of 100–200 nm while retaining a continuous percolation network for PEDOT. Atomic force microscopy,
dynamic light scattering and multi-angle light scattering measurements confirmed the wrapping of polymer chains around
the rod-like CNCs. The blended films exhibited improved molecular ordering of the PEDOT chains with concomitant
improvement in the carrier mobility. The remarkable self-organization and enhanced structural order enabled the CNC–
PEDOT:PSS blends to exhibit a high conductivity typical of PEDOT:PSS even when the content of the insulating CNCs in
the nanocomposite was as high as 50 wt%.
Remarkable self-organization and unusual conductivity behavior in cellulose n...Pawan Kumar
The document describes research on nanocomposites made from blending cellulose nanocrystals (CNCs) with PEDOT:PSS. Key findings include:
1) CNC-PEDOT:PSS blends self-organize into layered vertical stacks with a pitch of 100-200nm while maintaining a continuous polymer network.
2) Atomic force microscopy, dynamic light scattering, and multi-angle light scattering confirm wrapping of polymer chains around rod-like CNCs.
3) Blended films exhibit improved molecular ordering of PEDOT chains and enhanced structural order, enabling high conductivity even at 50wt% insulating CNC content.
Remarkable self-organization and unusual conductivity behavior in cellulose n...Pawan Kumar
The document describes research on nanocomposites made of cellulose nanocrystals (CNCs) blended with PEDOT:PSS. Key findings include:
1) CNC-PEDOT:PSS blends were found to self-organize into layered vertical stacks with a pitch of 100-200nm, while maintaining electrical conductivity even at 50wt% CNC loading.
2) Measurements showed the PEDOT polymer chains wrapped around the rod-like CNCs.
3) The blended films exhibited improved molecular ordering of PEDOT chains and enhanced structural order, enabling high conductivity typical of PEDOT:PSS.
Remarkable self-organization and unusual conductivity behavior in cellulose n...Pawan Kumar
Aqueous suspensions of cellulose nanocrystals were blended with Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) [PEDOT:PSS], and cast into thin films. The morphology, structure and electrical properties of the resulting nanocomposite thin films were thoroughly characterized. We found that the CNC–PEDOT:PSS blends self-organize into a layered vertical stack with a pitch of 100–200 nm while retaining a continuous percolation network for PEDOT. Atomic force microscopy, dynamic light scattering and multi-angle light scattering measurements confirmed the wrapping of polymer chains around the rod-like CNCs. The blended films exhibited improved molecular ordering of the PEDOT chains with concomitant improvement in the carrier mobility. The remarkable self-organization and enhanced structural order enabled the CNC–PEDOT:PSS blends to exhibit a high conductivity typical of PEDOT:PSS even when the content of the insulating CNCs in the nanocomposite was as high as 50 wt%.
UV/Vis Spectrometry as a Quantification Tool for Lignin Solubilized in Deep E...Michal Jablonsky
In this short communication, UV/Vis spectrophotometry is described as an analytical tool for the quantification of lignin content in deep eutectic solutions. The lignin was solubilized with different deep eutectic solvent (DES). DESs were prepared as binary mixtures of choline chloride with lactic acid (1:9); (1:10); ethylene glycol (1:2); glycerol (1:2) and alanine:lactic acid (1:9), and betaine:lactic acid (1:2). The UV-Vis spectrometric quantification of the solubilized lignins was independent of the type of solubilized lignin. The approach consists of measuring the absorbance of a solution of lignins dissolved in the deep eutectic solvents at an absorbance of 440 nm.
This document discusses how the pore size distribution affects drying shrinkage in alkali-activated slag concrete (AASC) compared to ordinary Portland cement concrete (OPCC). The main points are:
1) AASC exhibited higher drying shrinkage than OPCC even though OPCC lost more moisture during drying.
2) The pore size distribution of AASC pastes showed a much higher proportion of pores in the mesopore region compared to OPC pastes.
3) The radius of pores where the meniscus forms during drying seems to be a more important factor for shrinkage than the total moisture loss. This supports the theory that capillary tensile forces from drying cause shrinkage.
2018 - Flexible and porous cellulose aerogels-zeolitic imidazolate framework ...DrChimie
la courbe d'étalonnage peut être configurée en mesurant ou en entrant jusqu'à 10 étalons ou en entrant K et B facteursla courbe d'étalonnage peut être configurée en mesurant ou en entrant jusqu'à 10 étalons ou en entrant K et B facteurs
Influence of recycled Waste High Density Polyethylene Plastic aggregate on me...Jackson Kodua
The document examines using waste HDPE plastic as a partial replacement for coarse aggregate in concrete. Tests were conducted on concrete mixtures with 0%, 2%, 4%, 6%, and 8% plastic replacement by weight. Results showed workability decreased with more plastic while compressive and flexural strengths initially decreased marginally but then reduced further with more plastic. Water absorption of the concrete increased along with plastic content. Despite some effects on properties, all results were within acceptable limits, suggesting waste plastic could partially replace aggregates in concrete formulation.
This document analyzes the effects of alkaline and acid solutions on the mechanical properties of glass/epoxy composites. It finds that:
1) Immersion in hydrochloric acid (HCl) and sodium hydroxide (NaOH) solutions decreases the flexural strength and modulus of the composites over time.
2) The alkaline sodium hydroxide solution promotes a higher decrease in flexural properties than the acid hydrochloric solution.
3) Both solutions also decrease the impact strength of the composites with increased exposure time, with the alkaline solution again having a greater effect.
This document discusses various methods for preparing nanocomposites, including sol-gel processing, electrospinning, and melt mixing. It provides details on the sol-gel process, describing how a solution transforms into a gel network through hydrolysis and polycondensation reactions. Electrospinning is outlined as a method for producing polymer nanofibers containing nanofillers. The document concludes that nanocomposites can be made with enhanced properties using inexpensive techniques, and may find applications where light weight and high strength are needed.
This document presents the results of a neutron reflectometry study investigating the hydration of ultrathin antifouling organosilane adlayers on oxidized silicon wafers. The study finds that for a monoethylene glycol silane adlayer, there exists a relatively thick, continuous transition zone of water stemming from within the adlayer. In contrast, for a less effective adlayer lacking internal ether oxygen atoms, this physically distinct interfacial water phase is much thinner and confined to the adlayer-bulk water interface. These results provide further insight into the link between surface hydration and antifouling properties of organosilane adlayers.
This document presents a techno-economic analysis of a novel multi-crystallization system to achieve zero liquid discharge for brine treatment from desalination plants. The system uses an innovative heat recovery system and compressor to separately extract salts like calcite, anhydrite, sodium chloride, and epsomite from seawater brines. It is compared to a conventional brine treatment system in terms of energy demand and economic feasibility. Results found the multi-crystallization system can recover over 99% of water and over 98% of salts, but has a higher levelized cost of water at $13.79/m3 compared to $7.85/m3 for the conventional system. However, the additional
A dual mechanism of the drag reduction by rigid polymers and cationic surfact...eSAT Journals
Abstract
Several approaches have been employed to reduce the high cost of energy associated with the way liquids are transported in pipelines. Polymers have been widely explored to replace the pumping stations and other high energy cost mechanisms, but degrade over a period of time due to the accompanying turbulent mode of such transportation. Surfactants which are better alternatives with the ability to reenact their lost efficiency, are less effective, there is therefore the need for an alternative mechanism for drag reduction. In this present work, drag reduction efficacy of dispersed silica nanoparticle additives with polar additives as complexes and nanofluid have been investigated as a new method to reduce drag. Thus the present work was carried out with Xanthan gum which is able to withstand degradation compared to the flexible polymers, hexadecyltrimethyl ammonium chloride as the surfactant and sodium salicylate as the counterion. In the study both complexes and nanofluid were able to reduce drag as well as withstand shear stresses, although at different concentration which could be as a result of the different approaches of working, about 60% drag reduction was observed. It could thus be concluded that, these materials are able to reduce drag both as complex or nanofluid, only that, they could do that at different concentrations.
Keywords: Nanofluid, Polymers, Surfactants, Drag reduction, rotating disk apparatus, degradation
Spray Coating -A Rapid Method for preparation of nanocellulose filmKirubanandan Shanmugam
This document describes a new method for rapidly producing nanocellulose films using spray coating. Nanocellulose suspensions at consistencies ranging from 1.0-2.0% were sprayed onto stainless steel plates moving at 0.32 cm/s. Films with basis weights from 52.8-193.1 g/m2 could be produced in 1 minute, significantly faster than vacuum filtration which typically takes 10 minutes. The spray coated films had a smoother surface that was in contact with the steel plates compared to the outer surface. This spray coating technique is presented as a rapid and flexible method for producing nanocellulose films at the laboratory scale.
Polyethersulfone (PES) is a polymeric permeable material used in ultrafiltration (UF)
membranes due to its high thermomechanical and chemical stability. The hydrophobic nature of
PES membranes renders them prone to fouling and restricts the practical applications of PES in the
fabrication of water treatment membranes. The present study demonstrates a non-solvent-induced
phase separation (NIPS) approach to modifying PES membranes with different concentrations of
discrete TiO2 nanotubes (TNTs). Zeta potential and contact angle measurements showed enhanced
hydrophilicity and surface negative charge in TNTs/PES nanocomposite membranes compared to
unmodified PES membranes. To discern the antifouling and permeation properties of the TNTs/PES
membranes, steam assisted gravity drainage (SAGD) wastewater obtained from the Athabasca oil
sands of Alberta was used. The TiO2 modified polymer nanocomposite membranes resulted in a
higher organic matter rejection and water flux than the unmodified PES membrane. The addition of
discrete TNTs at 1 wt% afforded maximum water flux (82 L/m2 h at 40 psi), organic matter rejection
(53.9%), and antifouling properties (29% improvement in comparison to pristine PES membrane).
An enhancement in fouling resistance of TNTs/PES nanocomposite membranes was observed in
flux recovery ratio experiments.
Polyethersulfone (PES) is a polymeric permeable material used in ultrafiltration (UF) membranes due to its high thermomechanical and chemical stability. The hydrophobic nature of PES membranes renders them prone to fouling and restricts the practical applications of PES in the fabrication of water treatment membranes. The present study demonstrates a non-solvent-induced phase separation (NIPS) approach to modifying PES membranes with different concentrations of discrete TiO 2 nanotubes (TNTs). Zeta potential and contact angle measurements showed enhanced hydrophilicity and surface negative charge in TNTs/PES nanocomposite membranes compared to unmodified PES membranes. To discern the antifouling and permeation properties of the TNTs/PES membranes, steam assisted gravity drainage (SAGD) wastewater obtained from the Athabasca oil sands of Alberta was used. The TiO 2 modified polymer nanocomposite membranes resulted in a higher organic matter rejection and water flux than the unmodified PES membrane. The addition of discrete TNTs at 1 wt% afforded maximum water flux (82 L/m 2 h at 40 psi), organic matter rejection (53.9%), and antifouling properties (29% improvement in comparison to pristine PES membrane). An enhancement in fouling resistance of TNTs/PES nanocomposite membranes was observed in flux recovery ratio experiments. View Full-Text
Similar to Swelling properties of pulp treated with deep eutectic solvents (20)
Green solvents show several favorable features to be used as extraction and fractionation solvents, such as their ease of preparation and lower cost, and they can be both non-toxic and biodegradable when prepared with natural compounds. Due to their properties, green solvents' application in biomass fractionation has been extensively studied during the past years. The presented work describes the application of several possible combinations to create deep eutectic solvents with the potential to be used in processing different types of biomass. The results of studies suggest that deep eutectic solvents may have an important ability to dissolve lignin molecules from plants and can realize a mild catalytic mechanism (acid-base) that will activate the checked cleavage of non-stable ether linkages between phenylpropane units.
Phytomass valorization by deep eutectic solvents - achievements, perspectives...Michal Jablonsky
In recent years, a plethora of extraction processes have been performed by a novel class of
green solvents known as deep eutectic solvents (DESs), possessing several environmental, operational,
and economic advantages proven by experience when compared to organic solvents and ionic
liquids. The present review provides an organized overview of the use of DESs as extraction
agents for the recovery of valuable substances and compounds from the original plant biomass,
waste from its processing, and waste from the production and consumption of plant-based food.
For the sake of simplicity and speed of orientation, the data are, as far as possible, arranged in
a table in alphabetical order of the extracted substances. However, in some cases, the isolation
of several substances is described in one paper and they are, therefore, listed together. The table
further contains a description of the extracted phytomass, DES composition, extraction conditions,
and literature sources. With regard to extracted value-added substances, this review addresses their
pharmacological, therapeutic, and nutritional aspects. The review also includes an evaluation of
the possibilities and limitations of using DESs to obtain value-added substances from phytomass.
Involvement of Deep Eutectic Solvents in Extraction by Molecularly Imprinted ...Michal Jablonsky
Substantial research activity has been focused on new modes of extraction and refining
processes during the last decades. In this field, coverage of the recovery of bioactive compounds and
the role of green solvents such as deep eutectic solvents (DESs) also gradually increases. A specific
field of DESs involvement is represented by molecularly imprinted polymers (MIPs). The current state
and prospects of implementing DESs in MIPs chemistry are, based on the accumulated experimental
data so far, evaluated and discussed in this minireview.
Investigation of Total Phenolic Content and Antioxidant Activities of Spruce ...Michal Jablonsky
Extracts from spruce bark obtained using dierent deep eutectic solvents were screened for
their total phenolic content (TPC) and antioxidant activities. Water containing choline chloride-based
deep eutectic solvents (DESs) with lactic acid and 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, and
1,5-pentanediol, with dierent molar ratios, were used as extractants. Basic characteristics of the DESs
(density, viscosity, conductivity, and refractive index) were determined. All the DESs used behave
as Newtonian liquids. The extractions were performed for 2 h at 60 C under continuous stirring.
TPC was determined spectrophotometrically, using the Folin-Ciocalteu reagent, and expressed as
gallic acid equivalent (GAE). The antioxidant activity was determined spectrophotometrically by
2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay. The TPC varied from 233.6 to
596.2 mg GAE/100 g dry bark; radical scavenging activity (RSA) ranged between 81.4% and 95%.
This study demonstrated that deep eutectic solvents are suitable solvents for extracting phenolic
compounds from spruce bark.
Deep Eutectic Solvents: Fractionation of Wheat StrawMichal Jablonsky
Deep eutectic solvents (DESs) are a relatively new topic in science. Their usage is not yet clearly defined, and the areas in which DESs may be applied are constantly growing. A simple and clean fractionation of the main components of biomass represents a very important step in creating a clean, renewable carbon economy. A major challenge is the use of DESs for fractionation of biomass components at lower temperatures, without the use of expensive raw materials. In this work, wheat straw was pretreated with six different DES systems composed of choline chloride with urea (1:2), malonic acid (1:1), lactic (1:9; 1:10), malic (1:1), and oxalic acid (1:1). The pretreated biomass was characterized in terms of lignin content, ash, and holocellulose. A deep eutectic solvent, composed of choline chloride and oxalic acid, was found to produce the best delignification results. The solvents are not selective in the process of delignification.
CITE: Hodasova, L., Jablonsky, M., Skulcova, A., Haz, A. (2015). Lignin, potential products and their market value. Wood Research, 60(6), 973-986.
Author "Michal Jablonsky" gives permission to use information and pictures from publications
Lignin is one of the important components in the valorization of lignocellulosic biomass. Lignin-based materials and chemicals represent potential value-added products for biorefineries. Lignin products have numerous applications and can be divided into three main groups. Group, in which lignin is fragmentized into smaller aromatic compounds such as phenol or benzene, toluene and xylene, is less developed than group where lignin is used as macromolecule, but has greater potential. Lignin as macromolecule is used as additive or polymer blend. Last group of lignin products are carbon materials, which include carbon fibres.
Cellulose protectors for improving ozone bleaching - reviewMichal Jablonsky
The document reviews cellulose protectors that have been used to improve ozone bleaching processes. It systematically classifies protectors into 7 chemical groups and evaluates their effects on viscosity, kappa number, and brightness compared to bleaching without protectors. Alcohols and carboxylic acids are generally the most effective, positively impacting lignin removal while preventing carbohydrate degradation. Inorganic additives usually show no benefits. The protectors are thought to work by scavenging radicals, selective adsorption to cellulose, or forming protective compounds on the cellulose surface. Overall, no single protector was identified that strongly promotes lignin removal without also degrading cellulose.
The pH Behavior of Seventeen Deep Eutectic SolventsMichal Jablonsky
Deep eutectic solvents (DESs) are a unique category of green solvents that have gained attention in biomass processing due to their distinctive properties not offered by traditional solvents. The pH behavior of 17 selected DESs along with their temperature dependence on pH were evaluated in this study. For all investigated DESs, a temperature increase caused a decrease in pH value.
THERMAL STABILITY OF SELECTED DEEP EUTECTIC SOLVENTSMichal Jablonsky
n this study, a new type of " green solvents " named deep eutectic solvents (DESs) has been synthesized combining hydrogen bond acceptors (HBAs) and hydrogen bond donors (HBDs). Choline chloride (ChCl) was chosen as typical HBA, and lactic acid, tartaric acid, citric acid and oxalic acidwere chosen as HBDs. The thermal stability of deep eutectic solvents is an important parameter for their application and limits the maximum operation temperature. The thermal stability of DESs such as lactic, tartaric, citric and oxalic acid with choline chloride showed wide range of application (134.8 – 197.8°C). All DESs were observed in temperature range 25 – 400°C.
Long-term Isothermal Stability of Deep Eutectic SolventsMichal Jablonsky
Deep eutectic solvents play an important role in the clean production of chemicals and the fractionation of renewable sources. When dissolving lignin or cellulose at elevated temperatures, the thermal stability of deep eutectic solvents is of great importance. However, studies concerning the long-term isothermal stability of deep eutectic solvents are scarce. In this study, the thermal stability of deep eutectic solvents, namely, choline chloride with oxalic acid dihydrate, glycerol, glycolic, malic acid, and citric acid monohydrate were investigated using thermogravimetric analysis (TGA). The isothermal decomposition experiments were conducted at a constant temperature (60, 80, 100, and 120 °C) for 10 h. These long-term isothermal thermogravimetric studies of the deep eutectic solvents showed a non-linear weight loss as a function of time at each temperature. According to these studies it is recommended to perform fractionation or dissolution of biomass below 80 °C.
Determination of the Thermal Oxidation Stability and the Kinetic Parameters o...Michal Jablonsky
The use of olive oil with cooking purposes, as final seasoning or within cooked foods is increasing worldwide due to its numerous nutritional and health benefits. These attributes are mainly determined by olive oil chemical composition, which can be altered after thermal processing, oxidation processes, or incorrect practices. For this reason, and due to the numerous factors which have influence in olive oil quality, the correct chemical characterization is highly relevant. In this study, fatty acid composition of four extra virgin olive oil (EVOO) varieties was studied. The major fatty acid (FA) determined was oleic acid (77.1% on average), followed by palmitic (11.5% on average). In addition, thermal oxidation behaviour of the four EVOO samples was studied as an indicator of their quality and stability during thermal processing. This was performed through differential scanning calorimetry (DSC) from a temperature of 40°C at six different heating rates in the range of 0.5–10°C min ⁻¹ . DSC records showed the same pattern and a small shoulder in the thermo-oxidation peak was present for all samples and all heating rates. The presence of initial and final oxidation products (by monitoring K232 and K270 values, respectively) was discarded according to the International Olive Council method.
Pharmacokinetic Properties of Biomass-extracted Substances Isolated by Green ...Michal Jablonsky
According to the literature, approximately 41 nutraceutical compounds have been isolated from different types of biomass using green solvents. It is important to collect information on the pharmacokinetic properties of the nutraceutical substances from biomass isolated according to the published papers. The pharmacokinetic properties of the bioactive substances extracted by green solvents, such as the molecular weight, logP, AlogP, H-bond acceptor, H-bond donor, total polar surface area, atom molar refractivity, number of rotatable bonds, number of atoms, rotatable bond count, number of rigid bonds, number of atom rings, and number of H-bonds, were calculated with a drug-likeness tool. In practical terms, the original and most well-known Lipinski's Rule of Five (Ro5) was applied to 28 substances, namely 3-hydroxytyrosol; apigenin; artemisinin; bergapten; bilobalide; biochanin A; caffeic Acid; caffeoylmalic acid; catechins; cinnamic acid; curcumin; daidzei; daidzin; epicatechin; gallic acid; genistein; ginkgolide A; ginkgolide B; levofloxacin; luteolin; naringenin; p-coumaric acid; protocatechuic acid; psoralen; quercetin; trans-ferulic acid; tyrosol, and vanillin.
Chemical Composition and Thermal Behavior of Kraft LigninsMichal Jablonsky
Lignin has great potential for utilization as a green raw material or as an additive in various industrial applications, such as energy, valuable chemicals, or cost-effective materials. In this study, we assessed a commercial form of lignin isolated using LignoBoost technology (LB lignin) as well as three other types of lignin (two samples of non-wood lignins and one hardwood kraft lignin) isolated from the waste liquors produced during the pulping process. Measurements were taken for elemental analysis, methoxyl and ash content, higher heating values, thermogravimetric analysis, and molecular weight determination. We found that the elemental composition of the isolated lignins affected their thermal stability, activation energies, and higher heating values. The lignin samples examined showed varying amounts of functional groups, inorganic component compositions, and molecular weight distributions. Mean activation energies ranged from 93 to 281 kJ/mol. Lignins with bimodal molecular weight distribution were thermally decomposed in two stages, whereas the LB lignin showing a unimodal molecular weight distribution was decomposed in a single thermal stage. Based on its thermal properties, the LB lignin may find direct applications in biocomposites where a higher thermal resistance is required.
Nutraceuticals as phenolic bioactive compounds analysis of softwood bark and ...Michal Jablonsky
Softwoods have a numerically large group of economically important renewable plants. Waste processing of trees mainly bark, needles are reasonable extent not recovered. The waste contains relatively high levels of phenolic compounds. Phenolic compounds are one of the main components that have a high potential in various fields of food, pharmacy, and other industries. This review focuses on the main uses of softwood bark and overviews the extraction and analytical methods used to determine phenolic bioactive compounds in this matrix. At this time, various extraction techniques are used to obtain secondary metabolites from bark mainly bio-active phenolic compounds. The amount of bioactive compounds derived from the matrix affects the: extraction conditions, choice of the solvent, particle size, content of the water and, in particular, the extraction method. Amount and nature of the isolated compounds greatly depend on the isolation; the isolation is possible to use different methods: extraction in a Soxhlet apparatus, Soxtec extraction, accelerated solvent extraction, ultrasound-assisted, supercritical fluid extraction, pressurized liquid extraction, and microwave assisted extraction. According to literature were selected nutraceuticals phenolic compounds (isolated from softwood bark):Astringin; Catechin; Epicatechin; Ellagic acid; Ferulic acid; Gallic acid; Hydroxymatairesinol; isolariciresinol; Isorhapontigenin; Isorhapontin,lariciresinol; Lariciresinol-9-p-coumarate; Methylthy mol;p-Coumaric acid; Piceatannol; Piceid; Podocarpic acid; Quercetin; Resveratrol; Sesquipinsapol B; Sinapic acid; Tannic acid; Taxifolin; Vanillic acid; Vladinol D. From this viewpoint, it is important to collect information on pharmacokinetic properties of the nutraceuti- cal phenolic substances isolated from bark according to published papers. Pharmacokinetics properties of phenolic bioactive substances extracted by different techniques such as: molecular weight, logP, AlogP, H-bond acceptor, H-bond donor, total polar surface area, atom molar refractivity, number of rotatable bond, number of atom, rotatable bond count, number of rigid bond, number of atom ring, and number of Hydrogen Bond were calculated by DruLito (Drug LiknessTool).
Determination of volatile organic compounds emissions from wood processingMichal Jablonsky
Volatile organic compounds (VOCs) have received a great deal of attention due to their high abundance during the drying process of wood particles. This is a potential environmental issue due to being low level ozone precursors. This work aimed to study the emissions of VOCs during drying in the particleboard manufacturing process. In this study, wood particles were dry and VOCs were collected using a sorption tube. The VOCs were analyzed with gas chromatography-mass spectrometry to explore the effect of temperature on the composition of main components. The results indicated that α-pinene and D-limonene were the dominant components. The results also indicated that using natural gas or wood dust as a heat source did not have a major impact on the emission characteristics of VOCs.
Assessing the main opportunities used of biomass, biowaste from forestry, agr...Michal Jablonsky
Valorisation of biomass and food-related wastes including extraction of value-added compounds from these sources represent a dynamically developed area of research and technology. Substantial research activity has been focused on the new types of extraction and refining processes during the last decades. In the presence of green solvents such as deep eutectic solvents (DESs), naturally deep eutectic solvents (NADESs), and low-transition temperature mixtures (LTTMs) the interest for the recovery of new products and bioactive compounds usable as additives and functional ingredients in industrial food sector with the aim to enhance food quality has been renewed and reinforced. DESs, NADES, and LTTMS are attractive solvents for the deconstruction/fractionation (or pretreatment) of biomass and modification of cellulose. The scope of this study consists in identifying the nutritional and nutraceutical potential of raw by-products, and in using possible processes for the production of individual compounds by separation, fractionation, and extraction. Another section is oriented on the application green solvents for fractionation of biomass or delignification/modification of pulp, and their valorisation for the product of added value (fibres, cellulose nanofibrils, cellulose nanocrystals). Acknowledgement This work was supported by the Slovak Research and Development Agency under the contracts No. APVV-15-0052, APVV-0393-14, APVV-16-0088 and VEGA grant 1/0403/19.
Lignin is one of the important components in the valorization of lignocellulosic biomass. Lignin-based materials and chemicals represent potential value-added products for biorefineries.
Lignin products have numerous applications and can be divided into three main groups. Group, in which lignin is fragmentized into smaller aromatic compounds such as phenol or benzene, toluene and xylene, is less developed than group where lignin is used as macromolecule, but has greater potential. Lignin as macromolecule is used as additive or polymer blend. Last group of lignin products are carbon materials, which include carbon fibres.
Comparison of different extraction methods for the extraction of total phenol...Michal Jablonsky
Bark is an attractive renewable raw material, comprised of all types of silviculture vegetation. This renewable resource is a major alternative raw material for the food, chemical and pharmaceutical industry. Valorization is a key component of an economic lignocellulosic biorefinery. In this paper are included three extraction techniques and comparisons of total phenolic content. All extractions were done on milled spruce bark (Picea abies). Microwave assisted extraction; accelerated solvent extraction and extraction with deep eutectic solvents were used as a technique for extracts isolation. Choline chloride-based eutectic solvents with car-boxylic acids (maleic or malic acid) and glycerol were used as extractants. The extractions were performed for 1 h at 60 0 C with continuous stirring. Accelerated solvent extraction (extractant 96.6% ethanol; temperature (120, 140, 160 0 C) with steam pre-treatment (10, 20, 30 min.) was used as another type of extraction technique. The total phenolic content was determined spectrophotometrically at 764nm using the Folin-Ci-ocalteu method. This test is based on the oxidation of phenolic groups by phosphomolybdic and phospho-tungstic acids (FC reagent). Extraction technique using deep eutectic solvents brings results of phenolic contents in ranged from 900 to 2000 mg GAE per 100 g of dry bark. Samples with range of phenolic contents between 136.2 and 230.3 mg GAE per 100 g of dry bark were prepared by using acceleratet solvent extraction. Closed-system microwave assisted extraction (time 3 to 20 min.), and temperature (60; 80; 100 0 C) was applied to extract total phenolics from spruce bark, using 96.6% ethanol as an extractant. The total extracted phenolics, as assessed by Folin-Ciocalteu assay, varied between 90.3 and 321 mg gallic acid equivalence (GAE) per 100 g of dry bark for different temperatures. The results indicated that the highest amount of total phenolic compounds were found in extracts when using extraction by deep eutectic solvents
KINETIC STUDY OF ARTEFACT PAPER DEGRADATION. ASSESS MENT OF DEACIDIFICATION ...Michal Jablonsky
The present study investigates the stabilization of a 60 year old paper artefact via deacidification. Paper sheets
originating from a naturally-aged artefact book were subjected to accelerated ageing performed at 98 °C during 0, 3, 5,
10 and 15 days. A set of samples were deacidified before being subjected to accelerated aging. Deacidification was
performed using magnesium ethoxide and titanium ethoxide (METE) dissolved in hexamethyldisiloxane (HMDO) and
the properties of the thus treated samples were measured and compared to control samples. This study aims at finding
kinetic dependences for the decrease in the degree of polymerization and folding endurance of the paper subjected to
accelerated ageing. The deacidification effects were evaluated by the folding endurance of the paper artefact through
the multifactorial evaluation system developed by Consortium KnihaSK and Library of Congress.
The pH Behavior of Seventeen Deep Eutectic SolventsMichal Jablonsky
Deep eutectic solvents (DESs) are a unique category of green solvents that have gained attention in biomass processing due to their distinctive properties not offered by traditional solvents. The pH behavior of 17 selected DESs along with their temperature dependence on pH were evaluated in this study. For all investigated DESs, a temperature increase caused a decrease in pH value.
Unlocking the mysteries of reproduction: Exploring fecundity and gonadosomati...AbdullaAlAsif1
The pygmy halfbeak Dermogenys colletei, is known for its viviparous nature, this presents an intriguing case of relatively low fecundity, raising questions about potential compensatory reproductive strategies employed by this species. Our study delves into the examination of fecundity and the Gonadosomatic Index (GSI) in the Pygmy Halfbeak, D. colletei (Meisner, 2001), an intriguing viviparous fish indigenous to Sarawak, Borneo. We hypothesize that the Pygmy halfbeak, D. colletei, may exhibit unique reproductive adaptations to offset its low fecundity, thus enhancing its survival and fitness. To address this, we conducted a comprehensive study utilizing 28 mature female specimens of D. colletei, carefully measuring fecundity and GSI to shed light on the reproductive adaptations of this species. Our findings reveal that D. colletei indeed exhibits low fecundity, with a mean of 16.76 ± 2.01, and a mean GSI of 12.83 ± 1.27, providing crucial insights into the reproductive mechanisms at play in this species. These results underscore the existence of unique reproductive strategies in D. colletei, enabling its adaptation and persistence in Borneo's diverse aquatic ecosystems, and call for further ecological research to elucidate these mechanisms. This study lends to a better understanding of viviparous fish in Borneo and contributes to the broader field of aquatic ecology, enhancing our knowledge of species adaptations to unique ecological challenges.
Remote Sensing and Computational, Evolutionary, Supercomputing, and Intellige...University of Maribor
Slides from talk:
Aleš Zamuda: Remote Sensing and Computational, Evolutionary, Supercomputing, and Intelligent Systems.
11th International Conference on Electrical, Electronics and Computer Engineering (IcETRAN), Niš, 3-6 June 2024
Inter-Society Networking Panel GRSS/MTT-S/CIS Panel Session: Promoting Connection and Cooperation
https://www.etran.rs/2024/en/home-english/
ESR spectroscopy in liquid food and beverages.pptxPRIYANKA PATEL
With increasing population, people need to rely on packaged food stuffs. Packaging of food materials requires the preservation of food. There are various methods for the treatment of food to preserve them and irradiation treatment of food is one of them. It is the most common and the most harmless method for the food preservation as it does not alter the necessary micronutrients of food materials. Although irradiated food doesn’t cause any harm to the human health but still the quality assessment of food is required to provide consumers with necessary information about the food. ESR spectroscopy is the most sophisticated way to investigate the quality of the food and the free radicals induced during the processing of the food. ESR spin trapping technique is useful for the detection of highly unstable radicals in the food. The antioxidant capability of liquid food and beverages in mainly performed by spin trapping technique.
Describing and Interpreting an Immersive Learning Case with the Immersion Cub...Leonel Morgado
Current descriptions of immersive learning cases are often difficult or impossible to compare. This is due to a myriad of different options on what details to include, which aspects are relevant, and on the descriptive approaches employed. Also, these aspects often combine very specific details with more general guidelines or indicate intents and rationales without clarifying their implementation. In this paper we provide a method to describe immersive learning cases that is structured to enable comparisons, yet flexible enough to allow researchers and practitioners to decide which aspects to include. This method leverages a taxonomy that classifies educational aspects at three levels (uses, practices, and strategies) and then utilizes two frameworks, the Immersive Learning Brain and the Immersion Cube, to enable a structured description and interpretation of immersive learning cases. The method is then demonstrated on a published immersive learning case on training for wind turbine maintenance using virtual reality. Applying the method results in a structured artifact, the Immersive Learning Case Sheet, that tags the case with its proximal uses, practices, and strategies, and refines the free text case description to ensure that matching details are included. This contribution is thus a case description method in support of future comparative research of immersive learning cases. We then discuss how the resulting description and interpretation can be leveraged to change immersion learning cases, by enriching them (considering low-effort changes or additions) or innovating (exploring more challenging avenues of transformation). The method holds significant promise to support better-grounded research in immersive learning.
Phenomics assisted breeding in crop improvementIshaGoswami9
As the population is increasing and will reach about 9 billion upto 2050. Also due to climate change, it is difficult to meet the food requirement of such a large population. Facing the challenges presented by resource shortages, climate
change, and increasing global population, crop yield and quality need to be improved in a sustainable way over the coming decades. Genetic improvement by breeding is the best way to increase crop productivity. With the rapid progression of functional
genomics, an increasing number of crop genomes have been sequenced and dozens of genes influencing key agronomic traits have been identified. However, current genome sequence information has not been adequately exploited for understanding
the complex characteristics of multiple gene, owing to a lack of crop phenotypic data. Efficient, automatic, and accurate technologies and platforms that can capture phenotypic data that can
be linked to genomics information for crop improvement at all growth stages have become as important as genotyping. Thus,
high-throughput phenotyping has become the major bottleneck restricting crop breeding. Plant phenomics has been defined as the high-throughput, accurate acquisition and analysis of multi-dimensional phenotypes
during crop growing stages at the organism level, including the cell, tissue, organ, individual plant, plot, and field levels. With the rapid development of novel sensors, imaging technology,
and analysis methods, numerous infrastructure platforms have been developed for phenotyping.
When I was asked to give a companion lecture in support of ‘The Philosophy of Science’ (https://shorturl.at/4pUXz) I decided not to walk through the detail of the many methodologies in order of use. Instead, I chose to employ a long standing, and ongoing, scientific development as an exemplar. And so, I chose the ever evolving story of Thermodynamics as a scientific investigation at its best.
Conducted over a period of >200 years, Thermodynamics R&D, and application, benefitted from the highest levels of professionalism, collaboration, and technical thoroughness. New layers of application, methodology, and practice were made possible by the progressive advance of technology. In turn, this has seen measurement and modelling accuracy continually improved at a micro and macro level.
Perhaps most importantly, Thermodynamics rapidly became a primary tool in the advance of applied science/engineering/technology, spanning micro-tech, to aerospace and cosmology. I can think of no better a story to illustrate the breadth of scientific methodologies and applications at their best.
The binding of cosmological structures by massless topological defectsSérgio Sacani
Assuming spherical symmetry and weak field, it is shown that if one solves the Poisson equation or the Einstein field
equations sourced by a topological defect, i.e. a singularity of a very specific form, the result is a localized gravitational
field capable of driving flat rotation (i.e. Keplerian circular orbits at a constant speed for all radii) of test masses on a thin
spherical shell without any underlying mass. Moreover, a large-scale structure which exploits this solution by assembling
concentrically a number of such topological defects can establish a flat stellar or galactic rotation curve, and can also deflect
light in the same manner as an equipotential (isothermal) sphere. Thus, the need for dark matter or modified gravity theory is
mitigated, at least in part.
Immersive Learning That Works: Research Grounding and Paths ForwardLeonel Morgado
We will metaverse into the essence of immersive learning, into its three dimensions and conceptual models. This approach encompasses elements from teaching methodologies to social involvement, through organizational concerns and technologies. Challenging the perception of learning as knowledge transfer, we introduce a 'Uses, Practices & Strategies' model operationalized by the 'Immersive Learning Brain' and ‘Immersion Cube’ frameworks. This approach offers a comprehensive guide through the intricacies of immersive educational experiences and spotlighting research frontiers, along the immersion dimensions of system, narrative, and agency. Our discourse extends to stakeholders beyond the academic sphere, addressing the interests of technologists, instructional designers, and policymakers. We span various contexts, from formal education to organizational transformation to the new horizon of an AI-pervasive society. This keynote aims to unite the iLRN community in a collaborative journey towards a future where immersive learning research and practice coalesce, paving the way for innovative educational research and practice landscapes.
The ability to recreate computational results with minimal effort and actionable metrics provides a solid foundation for scientific research and software development. When people can replicate an analysis at the touch of a button using open-source software, open data, and methods to assess and compare proposals, it significantly eases verification of results, engagement with a diverse range of contributors, and progress. However, we have yet to fully achieve this; there are still many sociotechnical frictions.
Inspired by David Donoho's vision, this talk aims to revisit the three crucial pillars of frictionless reproducibility (data sharing, code sharing, and competitive challenges) with the perspective of deep software variability.
Our observation is that multiple layers — hardware, operating systems, third-party libraries, software versions, input data, compile-time options, and parameters — are subject to variability that exacerbates frictions but is also essential for achieving robust, generalizable results and fostering innovation. I will first review the literature, providing evidence of how the complex variability interactions across these layers affect qualitative and quantitative software properties, thereby complicating the reproduction and replication of scientific studies in various fields.
I will then present some software engineering and AI techniques that can support the strategic exploration of variability spaces. These include the use of abstractions and models (e.g., feature models), sampling strategies (e.g., uniform, random), cost-effective measurements (e.g., incremental build of software configurations), and dimensionality reduction methods (e.g., transfer learning, feature selection, software debloating).
I will finally argue that deep variability is both the problem and solution of frictionless reproducibility, calling the software science community to develop new methods and tools to manage variability and foster reproducibility in software systems.
Exposé invité Journées Nationales du GDR GPL 2024
Deep Software Variability and Frictionless Reproducibility
Swelling properties of pulp treated with deep eutectic solvents
1. See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/329482889
Swelling properties of pulp treated with deep eutectic solvents
Article in Drewno · December 2018
DOI: 10.12841/wood.1644-3985.266.08
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Slovak University of Technology in Bratislava
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Skulcova Andrea
Slovak University of Technology in Bratislava
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Slovak University of Technology in Bratislava
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2. Drewno 2018, Vol. 61, No. 202
DOI: 10.12841/wood.1644-3985.266.08
Michal JABLONSKY, Andrea SKULCOVA, Veronika MAJOVA, Jozef SIMA
SWELLING PROPERTIES OF PULP TREATED WITH DEEP
EUTECTIC SOLVENTS
The reaction of cellulose with water produces swelling and structural changes of
the fibres, both effects being of crucial importance for the understanding of paper
formation. It was investigated how the treatment of pulp with deep eutectic
solvents affects the swelling kinetics of the fibres. Unbleached kraft pulp was
treated with three deep eutectic solvents containing choline chloride (ChCl) –
ChCl:lactic acid (1:9), ChCl:oxalic acid (1:1) and ChCl:malic acid (1:1) – and
with the system alanine:lactic acid (1:9). The rate and maximum swelling of the
pulp in water were determined using a modified monitoring unit for measuring
swelling ability. Since paper swells extremely rapidly in water even at 23°C, this
apparatus made it possible for the first time to obtain accurate rate data on the
swelling of DES-delignified pulp in water.
Keywords: deep eutectic solvents, swelling, WRV, swelling kinetics, pulp
Introduction
The reaction of carbohydrates (cellulose and hemicelluloses) with water causes
swelling and structural changes of the fibres. Water converts the ligno-
-hemicellulose to a microporous gel, where lignin acts as a crosslinking agent
within the wall, and hemicellulose plays the role of a coupling agent between
lignin and cellulose [Salmén and Berthold 1997]. Hemicelluloses promote fibre
swelling, while lignin inhibits it [Niskanen 2000]. Swelling also yields more
flexible fibres, and the increased fibre flexibility promotes conformability, thus
allowing the formation of more fibre-fibre contacts and leading to improved web
strength [Toven 2000]. Deep eutectic solvents (DESs) represent a new
generation of compounds derived from renewable sources that have become
a focus of interest in science and technology in recent years. These technologies
are expected to be available by 2030, and according to forecasts they may come
into full industrial use by 2050. There are several reports on the delignification
Michal JABLONSKY
(michal.jablonsky@stuba.sk), Andrea SKULCOVA (andrea.skulcova@
gmail.com), Veronika MAJOVA (veronmajova@gmail.com), Institute of Natural and Synthetic
Polymers, Department of Wood, Pulp, and Paper, Slovak University of Technology,
Bratislava, Slovakia; Jozef SIMA (jozef.sima@stuba.sk), Department of Inorganic Chemistry,
Slovak University of Technology, Bratislava, Slovakia
3. 154 Michal JABLONSKY, Andrea SKULCOVA, Veronika MAJOVA, Jozef SIMA
of various types of biomass by DESs, and this research area is currently
undergoing significant development [Jablonsky et al. 2015, 2018; Kumar et al.
2015; Skulcova et al. 2016a, 2016b, 2017; Majova et al. 2017]. Deep eutectic
solvents are a breakthrough discovery and open the way to pulp production at
low temperatures and at atmospheric pressure. Delignification with deep eutectic
solvents has important advantages over oxygen delignification. The benefits of
using DESs as a reaction medium include the fact that they are biodegradable,
nontoxic and recyclable, and can be prepared easily using cheap raw materials.
The advantages of DES application include the lower temperature (60°C) and
the use of an unpressurized system, which reduces equipment costs. An apparent
disadvantage may be the necessity to introduce a system for DES recycling;
however, recycled DES can be repeatedly used for delignification. Another
benefit is that the lignin obtained by DES delignification is relatively pure.
Moreover, DES delignification is associated with a lower degree of cellulose
degradation and thus higher selectivity. Given the fact that a similar degree of
delignification is obtained with DES as with oxygen, reduced emissions from the
bleach plant, reduced consumption of bleaching chemicals, and a higher
brightness ceiling in a given bleaching sequence can be expected when using
DES delignification. The aforementioned benefits may contribute to
a broadening of research into the application of DESs in batch delignification,
and later also its introduction into the process of bleached pulp production. It is
important to remember that water penetration and swelling are processes with
specific kinetics [Mantanis et al. 1995; Olejnik 2012; Botkova et al. 2013;
Jablonsky et al. 2014]. Various methods are used to determine the swelling
ability of pulp fibres in water. The most common of these are measurement of
the centrifugal water retention value (WRV), microscopic measurement, and
monitoring of the dimensional changes of pulp sheets immersed in water using
sensors that convert the dimensions into electronic signals. These changes are
reported in a number of studies [Bristow 1972; Stone and Scallan 1967, 1968;
Racz and Borsa 1995, 1997; Botkova et al. 2013; Jablonsky et al. 2014; Geffert
et al. 2017]. In the swollen state, the fibre wall is saturated until it is
delaminated, the surfaces are fibrillated, and a high specific bonding strength in
the papermaking process is achieved. The properties of pulp fibres depend on the
representation of the major chemical components in the cell wall, and hence on
the delignification method [Cao et al. 1998]. The hydroxyl groups are fully
involved in hydrogen bonds [Stone et al. 1966]. From this standpoint, the cell
wall is compact and relatively rigid. The entry of water into the cell wall leads to
disruption of bonds, separation of the material, and change of structure [Scallan
1983]. The intrinsic cohesion of cellulosic fibres, containing inter- and
intramolecular hydrogen bonds, influences the swelling properties and
accessibility to reactive groups [Botkova et al. 2013; Jablonsky et al. 2014].
A critical factor affecting the resulting sheet strength is the chemical
composition of pulp fibres, which affects interfacial and intra-fibrous bonding.
4. Swelling properties of pulp treated with deep eutectic solvents 155
The influence of hemicellulose and lignin content is significant. The degree of
swelling depends on the solvent used, temperature, ionic strength, chemical
composition and internal fibrillation of the cellulose fibres [Salmén and Berthold
1997]. In our case, a modified glass monitoring unit was used to measure the
swelling of pulp delignified by DESs, in addition to the standard measurement
of water retention values. Our main goal was to investigate the change in the
pulp’s properties (swelling, WRV) resulting from the use of DES and to compare
it with pulp that had undergone an oxygen delignification stage.
Materials and methods
Deep eutectic solvent delignification
All chemicals were purchased from Sigma Aldrich (Bratislava, Slovakia). The
solutions were stirred in a water bath to form a homogeneous liquid. Pulp (50 g
absolute dry weight) and 115 mL water were added to a specific DES at a ratio
of 1:20 (wt/wt), with a pulp consistency of 4.8%. The DESs used were
combinations of choline chloride with lactic acid (1:9), oxalic acid (1:1) and
malic acid (1:1), and the system alanine:lactic acid (1:9). Delignification was
carried out for 1 h in a drying oven with a preset temperature of 60°C. The
delignified pulp was washed with water. The characteristics of the pulp and the
effect on its properties resulting from DES delignification [Majova et al. 2017;
Skulcova et al. 2017], expressed by kappa number and degree of polymerization,
are listed in table 1.
Table 1. Characteristics of pulp and effect on its properties after DES
delignification
Kappa no. Degree of polymerization
Kraft pulp* 21.7 ±0.6 1157 ±23
DES1: ChCl:oxalic acid 13.3 ±0.4 930 ±14
DES2: ChCl:malic acid 13.2 ±0.3 1130 ±13
DES3: alanine:lactic acid 12.3 ±0.6 1149 ±11
DES4: ChCl:lactic acid 13.5 ±0.4 1134 ±9
Oxygen-delignified pulp* 11.8 ±0.3 805 ±12
* – Mondi SCP, Ružomberok, Slovakia; ChCl – choline chloride.
5. 156 Michal JABLONSKY, Andrea SKULCOVA, Veronika MAJOVA, Jozef SIMA
Measurement of swelling kinetics
To monitor the swelling kinetics of pulp sheet, a modified monitoring unit for
measuring the swelling ability of wood was used [Solar et al. 2006]. Swelling is
determined as the difference of the current and initial dimensions of the sample
expressed as a percentage (eq.1):
SS =
(Fti−F0 )
F0
×100() (1)
where SS is the swelling in a plane perpendicular to the paper, Fti is the thickness
of the paper during monitoring, ti is any time from 0 to 6000 s, and F0 is the
initial thickness of the paper at the initial moisture content. The relative rate
constant of the initial fast phase of swelling is computed as the gradient of
a tangent drawn through the linear part on the kinetic plot [Solar et al. 2006].
The experiment used samples in the form of sheets with an initial diameter of
4 cm2
. All samples reached equilibrium moisture content; the initial moisture
content of the paper samples ranged between 3.7% and 4.8%. The final reported
values of swelling are averages of four measurements.
Water retention value (WRV) for pulp (fibres plus fines)
To calculate the WRV the following expression was used (eq. 2):
WRV =
m1−m2
m2
×100 (2)
where m1 and m2 are the masses of centrifuged wet pulp and dry pulp
respectively. Determination of the WRV was performed according to ISO 23714.
Centrifugation was carried out at 3000 min−1 for 30 min. After centrifugation,
the samples were weighed and subsequently dried in an oven at 105 ±2°C to
constant mass. Data points represent the average of four replicates, and the
standard deviation is less than 4.6%.
Results and discussion
The spreading of liquids into paper is an intricate process. The kinetics of
cellulose handsheet swelling are affected by several factors, such as the initial
moisture of the sheets, temperature, pressure, type of swelling media used, and
method of pulp treatment and bleaching. The diffusion of liquid into the paper
can be described [Karppinen 2008] as a process of the movement of water within
capillaries, pores and cavities [Gupta and Chatterjee 2003]. In our case water is
transported to the sheet sample through the paper cross-section and from all
directions at the beginning of the measurement. Here, the inhomogeneity of the
6. Swelling properties of pulp treated with deep eutectic solvents 157
sheet samples is due to the different arrangements of fibres in single sheets of
paper.
Figure 1 shows swelling profiles of unbleached kraft pulp, oxygen-
-delignified pulp (fig. 1a) and pulp delignified with the DES systems (fig. 1b), in
the form of plots of percentage swelling against time. The kinetic curves indicate
two distinct phases: a short and fast initial phase, lasting for only a few seconds,
with a high swelling gain, where the swelling rate reaches a maximum, followed
by a long but slow phase with a low swelling increment, where the swelling rate
approaches zero (final swelling). In this phase, the fibres become fully saturated
and equilibrium is established. The maximum equilibrated swelling is reached
after about 1 hour of swelling in water at 23 ±2°C. The swelling kinetics were
evaluated by regression analysis (eq. 3):
y1=A⋅(1−e
−kt
) (3)
where y1 is the swelling (%), A is the maximum swelling (%), k is the rate
constant determining the rate of attainment of the limiting (maximal) value
A (s-1
), and t is the swelling time (s).
Fig. 1a. Swelling profiles of unbleached kraft pulp and oxygen-delignified pulp
0 50 100 150 4000 6000
0
5
10
15
20
25
30
35
Oxygen delignified pulp
Swelling[%]
Time [s]
Kraft pulp
7. 158 Michal JABLONSKY, Andrea SKULCOVA, Veronika MAJOVA, Jozef SIMA
Fig. 1b. Swelling profiles of sheets of paper with different DES treatments. DES1:
ChCl:oxalic acid; DES2: ChCl:malic acid; DES3: alanine:lactic acid; DES4:
ChCl:lactic acid
The results in table 2 show the maximum swelling values and swelling rates
of paper sheet. The rate constant of swelling for kraft pulp samples is 0.1549 s-1,
and the maximum swelling is 31.15%. This is the highest rate constant, and
delignification leads to a very large decrease in its value. The rate constant of
swelling for delignified pulp is 1.4-2.4 times smaller, and the maximum swelling
is 1.5-2.2 times lower, than for the kraft pulp. For oxygen-delignified pulp
45.6% of the lignin content of the kraft pulp was removed. As a result, the pulp
had a maximum swelling rate constant of 0.0648 s-1
and a maximum swelling of
21%. The data for the rate constant and saturation on swelling are given in
table 2, and document the differences resulting from the use of particular DESs.
Irrespective of the delignification method, both swelling rate constant and
maximum swelling are lower for delignified pulp than for untreated kraft pulp.
The pulp delignified using the choline chloride systems with lactic acid and
malic acid had approximately the same maximum swelling (21.1% and 20.5%).
A short and fast initial phase with a rate constant of 0.1152 s-1
was obtained for
DES4 (ChCl:lactic acid); for DES2 (ChCl:malic acid) the value was 0.0746 s-1.
For pulp delignified with DES1 and DES3 the maximum swelling was 15.9%
and 14.2% respectively.
0 50 100 150 4000 6000
0
5
10
15
20
25
DES 2
Swelling[%]
Time [s]
DES 4
DES 3
DES 1
8. Swelling properties of pulp treated with deep eutectic solvents 159
Table 2. Maximum swelling values and swelling rates of samples
Sample
k
(s1
)
Maximum swelling
(%)
WRV
(%)
Moisture
(%)
Kraft pulp 0.1549 31.15 ±4.61 111 ±1.9 4.77
Oxygen-delignified pulp 0.0648 21.01 ±3.81 117 ±2.5 4.25
DES1: ChCl:oxalic acid 0.0853 15.88 ±3.16 95 ±1.6 3.71
DES2: ChCl:malic acid 0.0746 20.48 ±3.35 101 ±4.1 3.79
DES3: alanine:lactic acid 0.0854 14.18 ±2.39 95 ±3.2 4.65
DES4: ChCl:lactic acid 0.1152 21.08 ±1.10 99 ±2.4 4.08
ChCl – choline chloride
Fibres immersed in water are first wetted on the surface, and then the water
penetration continues to the interfibre areas, lumens and capillary cell walls. The
penetration rate for liquids is higher in larger capillaries, which actuate the liquid
flow to a greater degree than narrow capillaries and have much greater suction
power. The process of delignification can affect the properties of fibres. In
previous reports [Sirviö et al. 2015; Li et al. 2017] the fibrillation effect of deep
eutectic solvents on cellulose has been described. In these processes the
fibrillation is facilitated by an increase in the anionic charges on the fibre
surfaces with the introduction of charged groups. The fibre surface changes
influenced the effect of swelling on the pulp. Inhibition of water penetration into
the fibre leads to debonding and thus separation of the structural elements in the
fibre wall, as well as softening of its structure. The swelling of the structure has
a direct impact on the flexibility of the fibres. It was therefore decided to
compare the swelling parameters discussed above with the water retention value
(WRV) for pulp delignified by different DESs. The WRV values for pulp
delignified with DES1, DES2, DES 3 and DES4 were respectively 95%, 101%,
95% and 99%. The original untreated kraft pulp has a WRV of 111%. On oxygen
delignification the WRV of the pulp increased to 117%. It is clear that there is no
correlation between the measured swelling parameters and WRV. This result, and
the scattered attempts at rationalization of the pulp swelling process in the
literature, have led us to the conclusion that the process deserves a more detailed
discussion. Comparing the results of the swelling analyses obtained by these
methods, it may be noted that in each of the methods the analysis is based on
a different principle. For the continuous analysis of swelling kinetics using
a modification of the monitoring unit, the method describes the real behaviour of
9. 160 Michal JABLONSKY, Andrea SKULCOVA, Veronika MAJOVA, Jozef SIMA
the fibre on penetration of water into the paper structure and the cell walls. WRV
measurement is a standardized method for determination of the quantity of water
bound to the fibre after standardized centrifugation of the sample [Lindström
1980]. The fibre phase volume is referred to as the Donnan volume and is
approximately equivalent to the water retention value (WRV) [Towers and
Scallan 1996]. Donnan’s theory probably describes the swelling of the gel phase
(i.e. the fibre wall) [Grignon and Scallan 1980]. On the other hand, the WRV
method explains different aspects of fibre behaviour and has been used for the
calculation of the distribution of ions in pulp suspensions [Scallan 1989]. In
a nutshell, one of the methods describes the behaviour of fibres on water
penetration into a sheet of paper, while the other method relates to the behaviour
of a fibre suspension from the standpoint of forces and properties of the paper
that enable the retention of water in its structure; it therefore describes bound
water in pulp and paper structures. The degree of swelling of the fibre is a result
of a balance between swelling forces and the restraining network forces of the
fibrillary fibre wall. As the yield of the pulping process decreases there will be
less lignin in the fibre wall and hence also more empty space, giving rise to
a less rigid fibre wall that may respond to the swelling forces induced by the
charges in that wall [Fält 2003]. This effect was not unequivocally confirmed in
our work. Despite the additional removal of lignin, the individual delignified
pulps behave differently. This can be explained by the involvement of other
factors that influence the swelling process, especially fibre fibrillation,
hemicellulose degradation and the impact of interactions. The swelling of the
fibre is affected mainly by the content of hydroxyl groups in the fibres and the
content of ions in the swelling medium. The contribution to adsorption from
a hydroxyl group in cellulose is assumed to be the same as the contribution to
adsorption from a hydroxyl group in hemicellulose or in lignin [Berthold et al.
1996]. Additional swelling can take place if dissociable groups attached to the
fibres are ionized. The observed swelling effect is determined, however, not only
by the charge density but also by the degree of crosslinking of the fibre wall and
the chemical environment around the fibres [Fält 2003]. Delignified wood or
softwood kraft is more flexible and also more sensitive to different chemical
conditions [Carlsson et al. 1983]. At higher degrees of delignification, there are
few charges left in the pulp, due to the dissolution of hemicelluloses, and thus
the swelling effect also decreases [Lindström 1980]. Depending on the
conditions and degree of delignification, a broad range of differently charged
fibres with different stiffness can hence be obtained. The balance between these
two entities, i.e. the swelling forces induced by the charges in the fibre wall and
the rigid fibrillary network, determine the swelling behaviour of the fibre wall. It
should also be noted that a certain rigidity of the fibrillary network is necessary
in order to restore the elasticity of the fibre wall [Fält 2003]. At higher
temperatures, the water molecule penetrates into the fibre structure more easily
because the strength of association of water molecules is lessened. The motion
10. Swelling properties of pulp treated with deep eutectic solvents 161
of molecular chain segments is activated at higher temperatures [Sumi and Kanai
1962]. On the other hand, it has been reported [Eriksson et al. 1991] that
holocellulose, which is free from lignin, showed a high degree of swelling at
20°C, but as in the case of cellulose, the WRV was not affected by an increase in
temperature. This effect was eliminated because deionized water at temperature
23°C was used in the swelling measurements. Eriksson et al. [1991] also
identified the relation between swelling and the relative amount of cellulose and
hemicellulose in delignified pulps. Authors such as Eriksson et al. [1991] and
Carlsson et al. [1983] have confirmed the increase in swelling with increasing
delignification. In the work of Kumar et al. [2011] it was confirmed that the
accessibility of the cellulose, as indicated by the increase in the WRV value,
increased with increasing lignin removal. Earlier works [Ahlgren and Goring
1971; Ahlgren et al. 1971] showed that chlorite delignification solubilized the
high-molecular-weight lignin and consequently increased fibre swelling. When
pulp is dried, the hysteresis phenomenon provides a substantial reduction in the
WRV of the pulp [Foelkel 2007]. On the other hand, dried pulps, with lower
WRV, have much better drainage in the wet end. However, excessive fibre
swelling and hydration may be help to reduce hornification. Also, they facilitate
refinement to some extent, and the desired strengths are attained more easily.
The elasticity of the fibre wall and its ability to respond to swelling in different
environments, as well as to create a rigid network, are extremely important in
many paper products at industrial level.
Conclusions
The main outcome of this study was the continuous measurement of pulp fibre
swelling in pulp that had been delignified using various deep eutectic solvents.
The described method and apparatus made it possible to obtain accurate kinetic
data on paper swelling. In addition, the WRV was used to describe the swelling.
These two methods are based on different measurement principles. WRV testing
provides an indication of the pulp’s ability to take up water and swell, while the
monitoring of swelling by continuous measurement describes the actual
behaviour of the fibres and the paper structure due to the action of water. It was
found that treatment and additional delignification (both DES and oxygen
delignification) led to a rate constant that was 1.4-2.4 times smaller than for the
original untreated kraft pulp, and a maximum swelling that was 1.5-2.2 times
smaller. The WRV values following treatment with DES1 (ChCl:oxalic acid),
DES2 (ChCl:malic acid), DES3 (alanine:lactic acid) and DES4 (ChCl:lactic
acid) were respectively 95%, 101%, 95% and 99%, substantially smaller than
the WRV of the original kraft pulp (111%) or oxygen-delignified pulp (117 %).
11. 162 Michal JABLONSKY, Andrea SKULCOVA, Veronika MAJOVA, Jozef SIMA
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Acknowledgements
This work was supported by the Slovak Research and Development Agency
under contracts no. APVV-16-0088, and APVV-15-0052. This work was also
partially supported by the Slovak Scientific Grant Agency under the contracts
VEGA 1/0403/19 and VEGA 1/0543/15. The authors would like to thank the
STU Grant scheme for the Support of Young Researchers under contract No.
1696 and 1697 for financial assistance.
Submission date: 2.01.2018
Online publication date: 7.12.2018
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