The mechanism of heterogeneous nucleation of β-form L-glutamic acid was deeply investigated in cooling crystallization. The present study found that the β-form crystals were epitaxially grown on the α-form crystals and they were preferably crystallized on the (011) and (001) surfaces instead of the (111) surfaces of α- form crystals. This result was explained via the molecular simulation. The molecular simulation indicated that the different surfaces of α-form crystals provided different functional groups, resulting in different sites for the heterogeneous nucleation of β-form crystals. Here, the functional group were COO- , C=O and O-H on the (011) and (001) surfaces of α-form crystals, respectively, while it was the NH3 + on the (111) surfaces of α-form crystals. As such, the degree of lattice matching (E) between the β-form crystals and the various surfaces of α- form crystal was distinguished, where the degree of lattice matching (E) between the β-form crystals and the (011), (001) and (111) surfaces of α-form crystal were estimated as 5.30, 5.25 and 2.39, respectively, implying that the (011) and (001) surfaces of α-form crystal were more favorable to generate the heterogeneous nucleation of β-form crystals than the (111) surfaces of α-form crystal
Mr. Nitin Kanwale presented on using pharmaceutical co-crystals to improve the solubility of poorly water soluble drugs. Co-crystals involve crystallizing an active pharmaceutical ingredient with another compound, using interactions like hydrogen bonding and pi-stacking. This can enhance solubility and bioavailability. The presentation evaluated using spray drying as a technique for large-scale co-crystal production and characterized the co-crystals of carbamazepine and nicotinamide produced through this method. Phase solubility diagrams and in vitro dissolution studies confirmed improved solubility relative to the pure drugs.
Biological and mechanical properties of pmma based bioactive bone cements bio...Mohamed Moh
The document evaluates the mechanical properties and apatite-forming ability of PMMA bone cements containing varying amounts of wollastonite. Setting times, maximum temperature reached during setting, and compressive strength decreased as wollastonite content increased from 0% to 68%. Cements containing 19-39% wollastonite met the minimum compressive strength requirement of 70 MPa. XRD and SEM analysis showed apatite formation on the surfaces of cements containing 39-49% wollastonite after 21 days of immersion in simulated body fluid, indicating their potential bioactivity.
The document presents a research project on preparing and evaluating co-crystals of atorvastatin calcium with saccharin and urea. The objectives are to prepare the co-crystals using solvent drop grinding and solvent evaporation methods, characterize them using various techniques, and evaluate their solubility. The document outlines the materials, methods, results and discussion sections of the project including pre-formulation studies of atorvastatin calcium and the co-formers, characterization of the prepared co-crystals using FTIR, DSC and solubility testing, and evaluation of drug-excipient compatibility. The project aims to develop co-crystal formulations to improve the solubility and dissolution rate of the poorly soluble at
Co-crystals for improved physicochemical properties of poorly soluble drug Sana Roohi
Role of co-crystals in enhancement of physicochemical properties like flowability, chemical stability, dissolution characteristics of poorly soluble drugs
Preparation and characterization of co-crystals for improved physicochemical ...Sana Roohi
The document discusses various aspects of pharmaceutical co-crystals including definitions, types, characterization techniques, preparation methods and applications based on a literature review. Key points include: co-crystals can improve properties like solubility, bioavailability of APIs; common preparation methods are solvent evaporation, slurry conversion and solvent drop grinding; characterization involves techniques like PXRD, DSC, FTIR; literature examples demonstrate enhanced dissolution and bioavailability of drugs like atorvastatin, meloxicam through co-crystallization.
This document summarizes literature on cocrystal systems published in 2011 that are of interest to pharmaceutical scientists. It begins with an introduction to cocrystal systems and relevant review articles. It then discusses general articles on cocrystal engineering principles and characterization methods. The majority of the document summarizes literature on preparation methods for cocrystal systems and specific pharmaceutical cocrystal systems that were reported. It concludes with a discussion of regulatory guidance on pharmaceutical cocrystals.
Mr. Nitin Kanwale presented on using pharmaceutical co-crystals to improve the solubility of poorly water soluble drugs. Co-crystals involve crystallizing an active pharmaceutical ingredient with another compound, using interactions like hydrogen bonding and pi-stacking. This can enhance solubility and bioavailability. The presentation evaluated using spray drying as a technique for large-scale co-crystal production and characterized the co-crystals of carbamazepine and nicotinamide produced through this method. Phase solubility diagrams and in vitro dissolution studies confirmed improved solubility relative to the pure drugs.
Biological and mechanical properties of pmma based bioactive bone cements bio...Mohamed Moh
The document evaluates the mechanical properties and apatite-forming ability of PMMA bone cements containing varying amounts of wollastonite. Setting times, maximum temperature reached during setting, and compressive strength decreased as wollastonite content increased from 0% to 68%. Cements containing 19-39% wollastonite met the minimum compressive strength requirement of 70 MPa. XRD and SEM analysis showed apatite formation on the surfaces of cements containing 39-49% wollastonite after 21 days of immersion in simulated body fluid, indicating their potential bioactivity.
The document presents a research project on preparing and evaluating co-crystals of atorvastatin calcium with saccharin and urea. The objectives are to prepare the co-crystals using solvent drop grinding and solvent evaporation methods, characterize them using various techniques, and evaluate their solubility. The document outlines the materials, methods, results and discussion sections of the project including pre-formulation studies of atorvastatin calcium and the co-formers, characterization of the prepared co-crystals using FTIR, DSC and solubility testing, and evaluation of drug-excipient compatibility. The project aims to develop co-crystal formulations to improve the solubility and dissolution rate of the poorly soluble at
Co-crystals for improved physicochemical properties of poorly soluble drug Sana Roohi
Role of co-crystals in enhancement of physicochemical properties like flowability, chemical stability, dissolution characteristics of poorly soluble drugs
Preparation and characterization of co-crystals for improved physicochemical ...Sana Roohi
The document discusses various aspects of pharmaceutical co-crystals including definitions, types, characterization techniques, preparation methods and applications based on a literature review. Key points include: co-crystals can improve properties like solubility, bioavailability of APIs; common preparation methods are solvent evaporation, slurry conversion and solvent drop grinding; characterization involves techniques like PXRD, DSC, FTIR; literature examples demonstrate enhanced dissolution and bioavailability of drugs like atorvastatin, meloxicam through co-crystallization.
This document summarizes literature on cocrystal systems published in 2011 that are of interest to pharmaceutical scientists. It begins with an introduction to cocrystal systems and relevant review articles. It then discusses general articles on cocrystal engineering principles and characterization methods. The majority of the document summarizes literature on preparation methods for cocrystal systems and specific pharmaceutical cocrystal systems that were reported. It concludes with a discussion of regulatory guidance on pharmaceutical cocrystals.
Crimson Publishers-In vitro Bioactivity Assessment of Novel Composites Based ...CrimsonPublishersRDMS
In vitro Bioactivity Assessment of Novel Composites Based on Calcium Aluminate Cement by Cortés-Hernández DA in Research & Development in Material Science
The document summarizes research on producing hydroxyapatite (HAp) prototypes from gypsum/polyvinyl alcohol (PVA) composites. Porous gypsum blocks were produced by adding PVA to gypsum powder and molding. The blocks were then converted to HAp through chemical reaction in ammonium phosphate and hydroxide solutions. Characterization techniques confirmed the structures of gypsum, PVA composite, and final HAp. HAp prototypes after 36 hours of reaction showed predominant HAp peaks via XRD and EDS identified calcium and phosphorus. The HAp had high porosity (80%) and low compression strength (3.5 MPa) suitable for bone growth.
This document discusses co-crystals, which are crystalline materials composed of two or more components in the same crystal lattice. It outlines several advantages of co-crystals such as increased stability and solubility compared to amorphous forms. Common preparation methods include solution methods, grinding, and antisolvent techniques. Key characterization techniques are X-ray powder diffraction, infrared spectroscopy, and solubility analysis. Several marketed drug formulations utilizing co-crystals are also mentioned.
This document summarizes research on synthesizing a hydrate cocrystal of the antitubercular drug isoniazid and the antioxidant protocatechuic acid in a 1:1 ratio. The cocrystal was characterized using Fourier transform infrared spectroscopy, single crystal X-ray diffraction, and differential scanning calorimetry. Solubility and stability studies showed the cocrystal was less soluble but more stable than isoniazid alone. Single crystal X-ray diffraction confirmed hydrogen bonding between the nitrogen of isoniazid's pyridine ring and the hydrogen of protocatechuic acid's carboxylic acid group. This cocrystal formation may improve isoniazid's tablet
This document discusses the co-crystal technique for enhancing the solubility of poorly water soluble drugs. It introduces co-crystals as crystalline materials comprised of an active pharmaceutical ingredient and one or more co-crystal formers. Co-crystals can improve solubility and bioavailability through interactions like hydrogen bonding and pi-stacking. The document outlines various methods for preparing co-crystals, including solution methods, grinding, and supercritical fluid technology. It also discusses selecting appropriate co-formers, solvents, and evaluation methods like powder X-ray diffraction and solubility analysis. Several marketed drug products incorporating co-crystal technology are presented as examples.
The document discusses co-crystals, which are crystalline materials composed of an active pharmaceutical ingredient and a co-crystal former. Co-crystals can improve properties like dissolution rate and stability. They are formed through hydrogen bonding, pi-stacking, or van der Waals forces between components. Common preparation methods include solution crystallization, grinding, and antisolvent crystallization. Co-crystals are characterized using techniques like infrared spectroscopy, X-ray crystallography, and thermal analysis. Examples of co-crystallized drugs discussed include itraconazole, caffeine, and carbamazepine.
The document provides an overview of practical rheology and discusses its applications across many industries and materials. It describes how the American Society for Testing and Materials (ASTM) has established standards for rheological characterization and testing of a wide variety of products, including foods, biological fluids, petroleum products, polymers, paints, adhesives, and cosmetics. Many of these are complex formulations like emulsions or suspensions that require tailored rheological properties for optimal performance. Rheology is presented as an effective tool for characterizing industrial materials and ensuring consistent quality.
Seminar on "Crystal habit modification & it's industrial importance" prepared by Kishor Prajapati ( Final Year Chemical Engg. Student at Faculty of Technology & Engg.,M.S.University, Vadodara)
The Importance of Amorphous Stability: Mesoporous Silica for Poor Glass FormersMerck Life Sciences
Access the interactive recording: https://bit.ly/2SApPJr
Abstract: Historically, polymeric solid dispersions have been the technology of choice for amorphous formulation. However, this approach may have some downfalls when considering the ability to stabilize compounds in the amorphous form, especially poor glass former compounds with high propensity to re-crystallize. This webinar will examine amorphous stability from a theoretical perspective in the context of polymeric solid dispersions and mesoporous silica formulations. Finally, we will present recent data demonstrating the potential of mesoporous silica for superior amorphous stabilization of poor glass formers.
This document describes the osazone test, which is used to identify sugars. The test involves reacting sugars with phenylhydrazine at boiling point to form osazone crystals. Different sugars form characteristic crystal shapes that can be examined under a microscope to identify the type of sugar. The time it takes for crystals to form also helps in identification, with fructose forming crystals within two minutes while galactose takes 15-19 minutes. The test is useful for identifying reducing sugars.
A study of correlation of field data and Simulation of cement raw mixes and estimation of potential kiln feed as well as formed clinker made using a computer program through fitting of results obtained with field data. This enables production control by controlling quality of clinker within required specifications
SIMONA CAVALU_Microstructure and bioactivity of acrylic bone cementsSimona Cavalu
Polymer-ceramic composites based on polymethyl methacrylate are widely used in orthopaedics as suture materials and
fixation devices due to their biocompatibility and ability to support bony growth (osteoconductive) and also bone bioactive
(to form a calcium phosphate layer on its surface). In this study are compared the microstructure, bioactivity and
biocompatibility of two different types of biocomposites: BIOLOS3®and ANTIBIOTIC SIMPLEX®. They are investigated in
vitro in simulated body fluid using electrochemical measurements, SEM microscopy and ATR-FTIR spectroscopy in order to
evaluate the properties of the surface layer.
This document discusses pre-formulation studies, which involve investigating the physical and chemical properties of drug substances alone and when combined with excipients. Some key areas covered include polymorphism, hygroscopicity, particle size characterization, and solubility analysis. Thermal analysis techniques like DSC and XRD are described as useful for characterizing polymorphs. The importance of solubility studies at various pH levels and temperatures is highlighted for developing oral dosage forms with appropriate dissolution profiles.
Influence of processing and sterilisation on PCL Polymers, Rubber, Composites...Dr Neill Weir
This document discusses how processing and sterilization can affect the properties of poly-e-caprolactone (PCL), a biodegradable polymer. PCL pellets were either injection molded or extruded and then sterilized using ethylene oxide gas. Testing showed that processing and sterilization did not significantly change the polymer's molecular weight. However, crystallinity was affected. Injection molding increased crystallinity by 5%, and sterilization further increased crystallinity in all materials by approximately 10%. While properties like mechanical strength were not influenced by sterilization, the results suggest that sterilization does cause annealing of PCL and increases its crystallinity.
The document summarizes research on fluoridating and sintering hydroxyapatite material and measuring its resulting mechanical properties. Hydroxyapatite samples were prepared using a sol-gel technique with the addition of aluminum isopropoxide and teflon powder. The samples were then sintered at various temperatures between 1200-1460°C. Characterization of the sintered samples found they consisted of fluoridated hydroxyapatite crystals. Mechanical testing found that as sintering temperature increased, grain size increased up to 18.76 micrometers, while density and mechanical properties like hardness decreased. Sintering at 1250°C produced samples with the highest hardness and strength.
Processing, annealing and sterilisation of poly-l-lactide, Biomaterials, 2003Dr Neill Weir
1) The document examines how processing, annealing, and sterilization affect the properties of poly-l-lactide (PLLA), including its crystallinity, molecular weight, and mechanical properties.
2) It finds that compression molding and extrusion significantly reduced the crystallinity of PLLA pellets, but annealing increased crystallinity. Crystallinity further increased after sterilization with ethylene oxide gas.
3) A slight decrease in molecular weight was observed for extruded PLLA after processing, annealing, and sterilization. Mechanical properties like Young's modulus and tensile strength generally increased with higher crystallinity.
This document discusses preformulation studies, which focus on the physical and chemical properties of a new drug compound and how those properties could impact drug performance and dosage form development. The goals of preformulation studies are to establish the physicochemical parameters, kinetics, stability, and compatibility of a new drug compound alone and when combined with excipients. Key physicochemical properties investigated include particle size, shape, crystallinity, solubility, hygroscopicity, and stability. Understanding these properties helps with rational dosage form design and evaluation of product efficacy and stability.
This document discusses an experimental study on the effect of phosphate ions on the preparation of fly ash-based geopolymers. Fly ash was activated using a solution of sodium aluminium phosphate, with curing done atmospherically and through accelerated heating. Compressive strength was found to increase with higher activator concentrations and longer curing times. Accelerated curing at 60°C produced strengths 70% of the final strength within 4-5 hours. FTIR analysis showed structural changes after geopolymerization. The presence of phosphate ions was found to improve the strength properties of the fly ash geopolymers.
Industrial production of chemical acids glutamic acid 2Esam Yahya
Corynebacterium glutamicum is a soil bacterium that is used industrially for large-scale production of glutamic acid and lysine through fermentation. It was discovered in 1957 by Japanese researchers who found strains that could produce up to 10g/L of glutamic acid. Through genetic engineering, modern strains can produce over 100g/L. C. glutamicum extracts alpha-ketoglutarate from its metabolic pathway to produce glutamic acid through reductive amination. It is believed that low levels of an enzyme in its metabolic cycle force it to overproduce glutamic acid. C. glutamicum is now a major industrial producer of glutamic acid and lysine, with
Amino acids are produced through various methods including chemical synthesis, isolation from natural materials, fermentation, and chemo-enzyme methods. Fermentation is a widely used method that involves growing amino acid-producing microorganisms. There are different types of fermentation including batch, fed-batch, and continuous. Downstream processing is then required to separate and purify the amino acid produced, using methods like centrifugation, filtration, crystallization, and ion exchange. Monosodium glutamate is a common amino acid product that is produced through a fermentation process involving microorganisms and sugar cane, followed by purification steps to form the crystal product.
The document discusses the production of polyglutamic acid (PGA) by Bacillus subtilis isolates. Key points:
- Sixty-eight B. subtilis isolates were obtained from sugarcane fields, seawater, and marshes water, of which 21 could produce PGA. The highest PGA yields were obtained using isolates SC10 and SW5 in modified media.
- PGA was purified through various steps and identified using tests like ninhydrin, TLC, and spectroscopy. Molecular weights of PGA ranged from 97-131 kDa.
- Hydrogels were formed by treating PGA with gamma rays, alpha rays, beta rays and neutrons, with
Crimson Publishers-In vitro Bioactivity Assessment of Novel Composites Based ...CrimsonPublishersRDMS
In vitro Bioactivity Assessment of Novel Composites Based on Calcium Aluminate Cement by Cortés-Hernández DA in Research & Development in Material Science
The document summarizes research on producing hydroxyapatite (HAp) prototypes from gypsum/polyvinyl alcohol (PVA) composites. Porous gypsum blocks were produced by adding PVA to gypsum powder and molding. The blocks were then converted to HAp through chemical reaction in ammonium phosphate and hydroxide solutions. Characterization techniques confirmed the structures of gypsum, PVA composite, and final HAp. HAp prototypes after 36 hours of reaction showed predominant HAp peaks via XRD and EDS identified calcium and phosphorus. The HAp had high porosity (80%) and low compression strength (3.5 MPa) suitable for bone growth.
This document discusses co-crystals, which are crystalline materials composed of two or more components in the same crystal lattice. It outlines several advantages of co-crystals such as increased stability and solubility compared to amorphous forms. Common preparation methods include solution methods, grinding, and antisolvent techniques. Key characterization techniques are X-ray powder diffraction, infrared spectroscopy, and solubility analysis. Several marketed drug formulations utilizing co-crystals are also mentioned.
This document summarizes research on synthesizing a hydrate cocrystal of the antitubercular drug isoniazid and the antioxidant protocatechuic acid in a 1:1 ratio. The cocrystal was characterized using Fourier transform infrared spectroscopy, single crystal X-ray diffraction, and differential scanning calorimetry. Solubility and stability studies showed the cocrystal was less soluble but more stable than isoniazid alone. Single crystal X-ray diffraction confirmed hydrogen bonding between the nitrogen of isoniazid's pyridine ring and the hydrogen of protocatechuic acid's carboxylic acid group. This cocrystal formation may improve isoniazid's tablet
This document discusses the co-crystal technique for enhancing the solubility of poorly water soluble drugs. It introduces co-crystals as crystalline materials comprised of an active pharmaceutical ingredient and one or more co-crystal formers. Co-crystals can improve solubility and bioavailability through interactions like hydrogen bonding and pi-stacking. The document outlines various methods for preparing co-crystals, including solution methods, grinding, and supercritical fluid technology. It also discusses selecting appropriate co-formers, solvents, and evaluation methods like powder X-ray diffraction and solubility analysis. Several marketed drug products incorporating co-crystal technology are presented as examples.
The document discusses co-crystals, which are crystalline materials composed of an active pharmaceutical ingredient and a co-crystal former. Co-crystals can improve properties like dissolution rate and stability. They are formed through hydrogen bonding, pi-stacking, or van der Waals forces between components. Common preparation methods include solution crystallization, grinding, and antisolvent crystallization. Co-crystals are characterized using techniques like infrared spectroscopy, X-ray crystallography, and thermal analysis. Examples of co-crystallized drugs discussed include itraconazole, caffeine, and carbamazepine.
The document provides an overview of practical rheology and discusses its applications across many industries and materials. It describes how the American Society for Testing and Materials (ASTM) has established standards for rheological characterization and testing of a wide variety of products, including foods, biological fluids, petroleum products, polymers, paints, adhesives, and cosmetics. Many of these are complex formulations like emulsions or suspensions that require tailored rheological properties for optimal performance. Rheology is presented as an effective tool for characterizing industrial materials and ensuring consistent quality.
Seminar on "Crystal habit modification & it's industrial importance" prepared by Kishor Prajapati ( Final Year Chemical Engg. Student at Faculty of Technology & Engg.,M.S.University, Vadodara)
The Importance of Amorphous Stability: Mesoporous Silica for Poor Glass FormersMerck Life Sciences
Access the interactive recording: https://bit.ly/2SApPJr
Abstract: Historically, polymeric solid dispersions have been the technology of choice for amorphous formulation. However, this approach may have some downfalls when considering the ability to stabilize compounds in the amorphous form, especially poor glass former compounds with high propensity to re-crystallize. This webinar will examine amorphous stability from a theoretical perspective in the context of polymeric solid dispersions and mesoporous silica formulations. Finally, we will present recent data demonstrating the potential of mesoporous silica for superior amorphous stabilization of poor glass formers.
This document describes the osazone test, which is used to identify sugars. The test involves reacting sugars with phenylhydrazine at boiling point to form osazone crystals. Different sugars form characteristic crystal shapes that can be examined under a microscope to identify the type of sugar. The time it takes for crystals to form also helps in identification, with fructose forming crystals within two minutes while galactose takes 15-19 minutes. The test is useful for identifying reducing sugars.
A study of correlation of field data and Simulation of cement raw mixes and estimation of potential kiln feed as well as formed clinker made using a computer program through fitting of results obtained with field data. This enables production control by controlling quality of clinker within required specifications
SIMONA CAVALU_Microstructure and bioactivity of acrylic bone cementsSimona Cavalu
Polymer-ceramic composites based on polymethyl methacrylate are widely used in orthopaedics as suture materials and
fixation devices due to their biocompatibility and ability to support bony growth (osteoconductive) and also bone bioactive
(to form a calcium phosphate layer on its surface). In this study are compared the microstructure, bioactivity and
biocompatibility of two different types of biocomposites: BIOLOS3®and ANTIBIOTIC SIMPLEX®. They are investigated in
vitro in simulated body fluid using electrochemical measurements, SEM microscopy and ATR-FTIR spectroscopy in order to
evaluate the properties of the surface layer.
This document discusses pre-formulation studies, which involve investigating the physical and chemical properties of drug substances alone and when combined with excipients. Some key areas covered include polymorphism, hygroscopicity, particle size characterization, and solubility analysis. Thermal analysis techniques like DSC and XRD are described as useful for characterizing polymorphs. The importance of solubility studies at various pH levels and temperatures is highlighted for developing oral dosage forms with appropriate dissolution profiles.
Influence of processing and sterilisation on PCL Polymers, Rubber, Composites...Dr Neill Weir
This document discusses how processing and sterilization can affect the properties of poly-e-caprolactone (PCL), a biodegradable polymer. PCL pellets were either injection molded or extruded and then sterilized using ethylene oxide gas. Testing showed that processing and sterilization did not significantly change the polymer's molecular weight. However, crystallinity was affected. Injection molding increased crystallinity by 5%, and sterilization further increased crystallinity in all materials by approximately 10%. While properties like mechanical strength were not influenced by sterilization, the results suggest that sterilization does cause annealing of PCL and increases its crystallinity.
The document summarizes research on fluoridating and sintering hydroxyapatite material and measuring its resulting mechanical properties. Hydroxyapatite samples were prepared using a sol-gel technique with the addition of aluminum isopropoxide and teflon powder. The samples were then sintered at various temperatures between 1200-1460°C. Characterization of the sintered samples found they consisted of fluoridated hydroxyapatite crystals. Mechanical testing found that as sintering temperature increased, grain size increased up to 18.76 micrometers, while density and mechanical properties like hardness decreased. Sintering at 1250°C produced samples with the highest hardness and strength.
Processing, annealing and sterilisation of poly-l-lactide, Biomaterials, 2003Dr Neill Weir
1) The document examines how processing, annealing, and sterilization affect the properties of poly-l-lactide (PLLA), including its crystallinity, molecular weight, and mechanical properties.
2) It finds that compression molding and extrusion significantly reduced the crystallinity of PLLA pellets, but annealing increased crystallinity. Crystallinity further increased after sterilization with ethylene oxide gas.
3) A slight decrease in molecular weight was observed for extruded PLLA after processing, annealing, and sterilization. Mechanical properties like Young's modulus and tensile strength generally increased with higher crystallinity.
This document discusses preformulation studies, which focus on the physical and chemical properties of a new drug compound and how those properties could impact drug performance and dosage form development. The goals of preformulation studies are to establish the physicochemical parameters, kinetics, stability, and compatibility of a new drug compound alone and when combined with excipients. Key physicochemical properties investigated include particle size, shape, crystallinity, solubility, hygroscopicity, and stability. Understanding these properties helps with rational dosage form design and evaluation of product efficacy and stability.
This document discusses an experimental study on the effect of phosphate ions on the preparation of fly ash-based geopolymers. Fly ash was activated using a solution of sodium aluminium phosphate, with curing done atmospherically and through accelerated heating. Compressive strength was found to increase with higher activator concentrations and longer curing times. Accelerated curing at 60°C produced strengths 70% of the final strength within 4-5 hours. FTIR analysis showed structural changes after geopolymerization. The presence of phosphate ions was found to improve the strength properties of the fly ash geopolymers.
Industrial production of chemical acids glutamic acid 2Esam Yahya
Corynebacterium glutamicum is a soil bacterium that is used industrially for large-scale production of glutamic acid and lysine through fermentation. It was discovered in 1957 by Japanese researchers who found strains that could produce up to 10g/L of glutamic acid. Through genetic engineering, modern strains can produce over 100g/L. C. glutamicum extracts alpha-ketoglutarate from its metabolic pathway to produce glutamic acid through reductive amination. It is believed that low levels of an enzyme in its metabolic cycle force it to overproduce glutamic acid. C. glutamicum is now a major industrial producer of glutamic acid and lysine, with
Amino acids are produced through various methods including chemical synthesis, isolation from natural materials, fermentation, and chemo-enzyme methods. Fermentation is a widely used method that involves growing amino acid-producing microorganisms. There are different types of fermentation including batch, fed-batch, and continuous. Downstream processing is then required to separate and purify the amino acid produced, using methods like centrifugation, filtration, crystallization, and ion exchange. Monosodium glutamate is a common amino acid product that is produced through a fermentation process involving microorganisms and sugar cane, followed by purification steps to form the crystal product.
The document discusses the production of polyglutamic acid (PGA) by Bacillus subtilis isolates. Key points:
- Sixty-eight B. subtilis isolates were obtained from sugarcane fields, seawater, and marshes water, of which 21 could produce PGA. The highest PGA yields were obtained using isolates SC10 and SW5 in modified media.
- PGA was purified through various steps and identified using tests like ninhydrin, TLC, and spectroscopy. Molecular weights of PGA ranged from 97-131 kDa.
- Hydrogels were formed by treating PGA with gamma rays, alpha rays, beta rays and neutrons, with
Monosodium glutamate (MSG) is a flavor enhancer invented in 1908 that is the sodium salt of the naturally occurring amino acid glutamic acid. MSG is a white crystal with a melting point of 232°C that is soluble in water, and excessive consumption has been linked to health issues like obesity, diabetes, headaches and nausea. While MSG can enhance food flavors, studies suggest it is unhealthy to consume in large amounts.
Glutamate production and regulation of ionotropic glutamate receptors.pptx+ f...dariush Gholami
Dr. Dariush Ghulami presented on glutamate production and ionotropic glutamate receptors. Some key points:
- Glutamate is the main excitatory neurotransmitter in the central nervous system, acting on ionotropic glutamate receptors.
- It is commercially produced primarily through fermentation and used in food/feed additives and pharmaceuticals.
- Ionotropic glutamate receptors are ligand-gated ion channels that include NMDA, AMPA, and kainate receptors. The NMDA receptor requires binding of glutamate and glycine and is permeable to calcium.
- NMDA receptor activation plays a role in long-term potentiation involved in learning and memory
Industrial production of chemical acids glutamic acidEsam Yahya
Glutamic acid is an important amino acid that is produced industrially through fermentation using the microorganism Corynebacterium glutamicum. There are four main types of fermentation used - batch, fed-batch, continuous, and cell recycle batch fermentation. Batch fermentation is commonly used and involves inoculating a closed system with nutrients and microbes and allowing growth until nutrients are depleted. C. glutamicum is well-suited for industrial fermentation due to its rapid growth, ability to produce high yields of glutamic acid, and lack of pathogenicity. After fermentation, purification processes such as centrifugation, crystallization, and ion exchange are used to isolate glutamic acid.
Industrial Production of L-Lysine by FermentationKuldeep Sharma
Lysine is an essential amino acid that is used in the biosynthesis of proteins. Lysine is required for the nutrition of animals and humans. Lysine is useful as medicament, chemical agent, food material (food industry) and feed additives (animal food). It's demand has been steadily increasing in recent years. Several thousand tones of L-lysine are annually produced worldwide, almost by microbial fermentation.
±For Education Purpose Only
Downstream processing refers to the stages involved after fermentation or bioconversion, including separation, purification, and packaging of the product. The key stages are removal of insolubles through filtration, centrifugation or flocculation, product isolation using techniques like liquid-liquid extraction or adsorption, product purification using chromatography or crystallization, and product polishing which prepares the product for packaging and storage. Downstream processing aims to recover and purify the target product from the fermentation or reaction broth.
This document summarizes a study that investigated the surface reactivity and biocompatibility of SiO2–TiO2–CaO–Na2O/SrO bioceramics as a function of structure and incubation time in simulated body fluid. Glass and ceramic samples with varying sodium and strontium concentrations were characterized, incubated in simulated body fluid for up to 30 days, and evaluated for calcium phosphate deposition and changes in surface morphology. Cell culture analysis also assessed the effect on cell viability. The addition of strontium reduced solubility and calcium phosphate precipitation compared to sodium-containing materials. Crystallization also decreased reactivity compared to amorphous structures.
Efficient molybdenum(VI) modified Zr-MOF catalysts have been prepared for epoxidation of olefins. Zr-MOF (UiO-66(NH2)) was functionalized with ligands using post-synthesis modification and then loaded with Mo(VI) catalysts via chelating. The Mo(VI) catalysts were highly dispersed on the Zr-MOF, improving contact between substrates and active sites. The Zr-MOF catalysts exhibited high activity for epoxidation of olefins using TBHP or H2O2 as oxidants and showed good thermal stability.
The document discusses the effect of cross-linking modification on the structural and film-forming characteristics of pearl millet starch. Pearl millet starch was modified using different concentrations of epichlorohydrin (EPI) as a cross-linking agent. The degree of cross-linking increased with higher EPI concentrations. Cross-linked starches showed reduced breakdown and setback viscosity but increased pasting temperature. They also had improved resistance to heat, acid, and shear compared to native starch. The cross-linking improved the moisture barrier properties and mechanical strength of edible films formed from the modified starches.
Thermal characteristics and state diagram of freeze dried broccoli 2017Lucía Cassani
study, state diagram of broccoli was developed considering freezing curve, glass line, maximal-freeze-concentration
conditions, solids-melting and BET-monolayer line. The freezing point, glass transition and solidsmelting
were measured and modeled by Chen’s model, Gordon-Taylor model, and Flory-Huggins model, respectively.
The ultimate maximal-freeze-concentration conditions (Tm′)u (i.e. end temperature of freezing) and
(Tg′′′)u [i.e. end glass transition at (Tm′)u] were found as −30.0 °C and −32.2 °C, respectively, and solids content
(i.e. Xs′) at this point was 0.70 g/g sample. The solids-water interaction (χ) during melting was estimated as 0.69
(dimensionless) from Flory-Huggins model, and BET-monolayer was observed as 0.089 g/g dry-solids at 20 °C.
Group5.the influence of phosphorus precursors on the synthesis and bioactivit...Roy Rodriguez Solano
This document summarizes a study that investigated the influence of different phosphorus precursors on the synthesis and bioactivity of sol-gel derived SiO2-CaO-P2O5 bioactive glasses and glass-ceramics. Three phosphorus precursors were used - triethylphosphate, phosphoric acid, and a solution of phosphorus oxide in ethanol. The different precursors affected the gel formation time and crystallization behavior during heat treatment. Samples prepared with phosphoric acid had a lower crystallization onset temperature and higher resistance to devitrification. However, all resulting materials were bioactive. Bioactivity decreased with increasing heat treatment temperature and was favored in crystallized samples containing wollastonite and tricalcium phosphate
The document discusses biodegradable starch-clay nanocomposite films for food packaging. Starch is obtained from plants and is biodegradable, while clay is added to improve properties. The films are prepared by dispersing clay into starch with glycerol and heating. Characterization with FTIR, XRD and SEM show the clay is well dispersed in the starch matrix. The films are insoluble in water but degrade when exposed to microorganisms, suggesting potential use as biodegradable food packaging.
On the origin of surfaces-dependent growth of benzoic acid crystal inferred t...Maciej Przybyłek
Crystal growth behavior of benzoic acid crystals on different surfaces was examined. The performed experiments documented the existence of very strong influence introduced by polar surfaces as glass, gelatin, and polyvinyl alcohol (PVA) on the growth of benzoic acid crystals. These surfaces impose strong orientation effect resulting in a dramatic reduction of number of faces seen with x-ray powder diffractions (XPRD). However, scrapping the crystal off the surface leads to a morphology that is similar to the one observed for bulk crystallization. The surfaces of low wettability (paraffin) seem to be useful for preparation of amorphous powders, even for well-crystallizable compounds. The performed quantum chemistry computations characterized energetic contributions to stabilization of morphology related faces. It has been demonstrated, that the dominant face (002) of benzoic acid crystal, growing on polar surfaces, is characterized by the highest densities of intermolecular interaction energies determining the highest cohesive properties among all studied faces. Additionally, the inter-layer interactions, which stand for adhesive properties, are also the strongest in the case of this face. Thus, quantum chemistry computations providing detailed description of energetic contributions can be successfully used for clarification of adhesive and cohesive nature of benzoic acids crystal faces.
Mech durability of bioactive glass _structure_solubility_incubation timeyiming li
This study investigated the mechanical durability and solubility of bioactive glasses as a function of their structure, solubility, and incubation time. Specifically, it examined a series of glasses that alternated the concentrations of sodium and strontium ions. Ion release profiles, pH changes, and mechanical strength were analyzed after 1, 7, and 30 days of incubation in water. The results showed that ion release and pH changes were reduced when the glasses crystallized compared to their amorphous counterparts. Additionally, hardness significantly decreased over time for amorphous materials but remained higher for crystallized materials. The solubility differences could be attributed to the sodium-containing glasses, which were the most soluble and induced higher pH changes.
Preparation of ZnO Nanostructures by Solvothermail MethodHai Yen Dang
1) ZnO nanostructures were prepared using a solvothermal method with zinc acetate as a precursor at 80°C.
2) The type of solvent used influenced the morphology of the synthesized ZnO, with ethylene glycol producing spherical nanoparticles, ethanol producing nanorods, and a mixture producing semi-spherical structures.
3) Characterization with XRD, TEM, and UV-vis spectroscopy confirmed the successful synthesis of wurtzite phase ZnO nanostructures with sizes and shapes dependent on the solvent environment during preparation.
This study uses molecular dynamics simulations with the BKS potential to model the structures and calculate the enthalpy variations of 13 silica polymorphs over a range of densities. The key findings are:
1) The BKS potential predicts the lattice parameters of most silica phases within 2-3% accuracy and the relative stabilities of different polymorphs in agreement with experiment.
2) Enthalpies of high-density silica polymorphs that lack experimental data, such as CaCl2-type and α-PbO2-type, are predicted.
3) The calculated enthalpies exhibit two distinct regimes - almost independent of volume for low/medium-density phases, and a steep dependence for
Sodium and Strontium -Structure and solubilityyiming li
This document summarizes a study investigating the influence of sodium (Na+) and strontium (Sr2+) on the structure and solubility of bioactive glass. Three glass compositions were synthesized containing either Na+, Sr2+, or equal amounts of both. Characterization techniques found the glasses had similar structures but Sr2+ glasses had higher transition temperatures and hardness. Sr2+ glasses also showed much lower ion release rates than Na+ glasses. Cell studies found the glasses were not cytotoxic and cells adhered to all glass surfaces.
The document discusses a case study on the crystallization and stability of different crystal forms of the protein lysozyme. Specifically:
- Two crystal modifications of lysozyme (tetragonal and needle-shaped) were obtained and their phase diagrams and stability at different pH levels were analyzed.
- The solubility, crystal structures, and phase transition behavior of the two modifications were examined using various techniques like X-ray powder diffraction and microscopy.
- It was found that tetragonal crystals are more stable in acidic solutions while needle crystals are more stable in basic solutions, and the modifications can transition between each other under certain temperature and pH conditions.
On the origin of surface imposed anisotropic growth of salicylic and acetylsa...Maciej Przybyłek
In this paper droplet evaporative crystallization of salicylic acid (SA) and acetylsalicylic acid (ASA) crystals on different surfaces, such as glass, polyvinyl alcohol (PVA), and paraffin was studied. The obtained crystals were analyzed using powder X-ray diffraction (PXRD) technique. In order to better understand the effect of the surface on evaporative crystallization, crystals deposited on glass were scraped off. Moreover, evaporative crystallization of a large volume of solution was performed. As we found, paraffin which is non-polar surface promotes formation of crystals morphologically similar to those obtained via bulk evaporative crystallization. On the other hand, when crystallization is carried out on the polar surfaces (glass and PVA), there is a significant orientation effect. This phenomenon is manifested by the reduction of the number of peaks in PXRD spectrum recorded for deposited on the surface crystals. Noteworthy, reduction of PXRD signals is not observed for powder samples obtained after scraping crystals off the glass. In order to explain the mechanism of carboxylic crystals growth on the polar surfaces, quantum-chemical computations were performed. It has been found that crystal faces of the strongest orientation effect can be characterized by the highest surface densities of intermolecular interactions energy (IIE). In case of SA and ASA crystals formed on the polar surfaces the most dominant faces are characterized by the highest adhesive and cohesive properties. This suggests that the selection rules of the orientation effect comes directly from surface IIE densities.
This document summarizes research on the synthesis of zeolite ZSM3 from faujasite without the addition of structure directing agents. The key points are:
1. Zeolite ZSM3 was successfully synthesized from dealuminated metakaolin through post-synthesis aging and insitu seeding, transforming a matrix containing zeolites X, Y, and sodium aluminosilicate into pure ZSM3.
2. XRD and SEM analyses showed the ZSM3 peaks and crystallinity increased over time with aging and reaction progression.
3. Post-synthesis effects like exposure to moisture and residual NaOH were responsible for the faujasite to ZSM3 met
This document summarizes a study that modified the surface of poly(L-co-D,L-lactic acid) (PLDLA) scaffolds through grafting of carboxyl groups and immobilization of collagen type I to create a biomimetic surface. Characterization showed the surface morphology was markedly modified after treatment, with increased pores and roughness. Osteoblast-like cells cultured on the collagen-immobilized scaffolds showed significantly improved adhesion, proliferation, collagen synthesis and maintenance of phenotype compared to unmodified scaffolds, indicating the collagen modification enhanced biocompatibility. The surface modification method provides a strategy for developing biofunctional scaffolds for tissue engineering applications.
This document summarizes a study on the sorption and transport of Crystal Violet dye in and through biobased cryogel membranes made of poly(vinyl alcohol) blended with various biopolymers. The cryogels were characterized using techniques like SEM, DSC, and FTIR. Sorption isotherms and diffusion/permeability coefficients were determined for Crystal Violet dye diffusion into and out of the cryogels. The highest sorption capacity and removal efficiency for Crystal Violet from aqueous solutions was found for cryogels containing scleroglucan bioinsertions.
This document discusses the development of bioactive ceramics for bone regeneration applications. The ceramics were developed in the B2O3-MgO-SiO2-Na2O-CaO-P2O5-ZnO system using a sol-gel technique. Five compositions were prepared with varying amounts of B2O3. Characterization showed the materials were mesoporous and crystallized phases including hydroxylapatite and whitlockite. In vitro tests found the materials degraded appropriately and formed hydroxylapatite layers when soaked in simulated body fluid, indicating their bioactive nature. Biological studies of swelling, drug release, cytotoxicity and cell culture were also conducted. The results suggest these materials are promising
This document summarizes a study that compares the microstructure, bioactivity, and biocompatibility of two types of acrylic bone cements: BIOLOS3® and ANTIBIOTIC SIMPLEX®. Electrochemical measurements, SEM imaging, and FTIR spectroscopy were used to analyze the materials after incubation in simulated body fluid for up to 34 days. The results showed that ANTIBIOTIC SIMPLEX® developed a more intense mineralization layer on its surface, as evidenced by greater calcium phosphate formation and water uptake. Hemolysis testing also indicated ANTIBIOTIC SIMPLEX® had better blood compatibility. In conclusion, the antibiotic-containing cement demonstrated superior in vitro bioactivity and bi
Aquasomes are a novel nanoparticle drug delivery system composed of three layers - a solid ceramic or polymeric core, an oligomeric coating, and biologically active molecules adsorbed to the coating. They are spherical structures 60-300nm in size that mimic water-like properties to preserve the conformational integrity and biochemical stability of fragile molecules. Aquasomes have been investigated for delivery of vaccines, genes, insulin, enzymes, and dyes due to their ability to maintain molecule conformation. They show potential as targeted drug carriers with applications including intracellular gene therapy and development of blood substitutes.
Nucleation and growth process of sodalite and cancrinite from kaolinite rich ...Errol Jaeger
The synthesis of low-silica zeotypes by hydrothermal transformation of kaolinite-rich clay and the nucleation and growth processes of sodalite and cancrinite in the system Na2O–Al2O3–SiO2–H2O at 100 °C were investigated. The synthesis products were characterized by X-ray powder diffraction (XRPD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), 29Si and 27Al Magic Angle Spinning Nuclear Magnetic Resonance (MAS-NMR) and thermogravimetric analysis (TGA). Our data show that the sequence of the transformation of phases is: Poorly crystalline aluminosilicate → zeolite LTA → sodalite → sodalite + cancrinite → cancrinite. Synthesized materials appeared stable thermodynamically under the experimental conditions, with zeolite LTA (a metastable phase) occurring as a minor phase, compared with the presence of sodalite and cancrinite.
Similar to Crystallization of L-Glutamic Acid: Mechanism of Heterogeneous β -Form Nucleation (20)
Experimental Investigation of a Household Refrigerator Using Evaporative-Cool...inventy
The objective of this paper was to investigate experimentally the effect of Evaporative-cooled condenser in a household refrigerator. The experiment was done using HCF134a as the refrigerant. The performance of the household refrigerator with air-cooled and Evaporative-cooled condenser was compared for different load conditions. The results indicate that the refrigerator performance had improved when evaporative-cooled condenser was used instead of air-cooled condenser on all load conditions. Evaporativecooled condenser reduced the energy consumption when compared with the air-cooled condenser. There was also an enhancement in coefficient of performance (COP) when evaporative-cooled condenser was used instead of air-cooled condenser. The Evaporative cooled heat exchanger was designed and the system was modified by retrofitting it, instead of the conventional air-cooled condenser by making drop wise condensation using water and forced circulation over the condenser. From the experimental analysis it is observed that the COP of evaporative cooled system increased by 13.44% compared to that of air cooled system. So the overall efficiency and refrigerating effect is increased. In minimum constructional, maintenance and running cost, the system is much useful for domestic purpose. This study also revealed that combining a evaporative cooled system along with conventional water cooled system under the condition that the defrost water obtained from the freezer is used for drop wise condensation over condenser and water cooled condensation of the condenser at the bottom using remaining defrost water would reduce the power consumption, work done and hence further increase in refrigerating effect of the system. The study has shown that such a system is technically feasible and economically viable
Copper Strip Corrossion Test in Various Aviation Fuelsinventy
This research work takes in to account of corrosiveness test on various aviation fuels in the state of Telengana (India). The purpose of this experiment is to determine the corrosiveness test of fuels. This determination will be accomplished by using copper strip corrosion test by using the copper strip experiment we can determine the corrosive property of the fuel and hence the efficiency of fuel. The research covers the importance of knowing the corrosive property of different petroleum fuels including aviation turbine fuel.
Additional Conservation Laws for Two-Velocity Hydrodynamics Equations with th...inventy
1) The document presents differential identities connecting velocities, pressure, and body force in two-velocity hydrodynamics equations where the pressure in each component is in equilibrium.
2) It summarizes previous work that derived conservation laws and differential equations for two-velocity hydrodynamic systems. Additional conservation laws are derived for these types of systems.
3) The key results are theorems that present differential identities relating the module and direction of a vector field. These identities can be considered additional conservation laws for two-velocity hydrodynamics equations with a single pressure.
Comparative Study of the Quality of Life, Quality of Work Life and Organisati...inventy
People’s lives are increasingly centred on work; they spend at least one-third of their time within the organisations that employ them. Investigating the factors that interfere with employees’ well-being and the organisational environment is becoming an increasing concern in organisations. This article identifies the criteria of the quality of life (QoL), quality of working life (QWL) and organisational climate instruments to point out their similarities. For bibliographic construction and data research, articles were sought in national and international journals, books and dissertations/articles in SciELO, Science Direct, Medline and Pub Med databases. The results show direct relationships amongst QoL, QWL and organisational climate instruments. The relationship between QoL and QWL instruments is based on fair compensation, social interaction, organisational communication, working conditions and functional capacity. QWL and organisational climate instruments are related through social interaction and interfaces. QoL and organisational climate instruments are related based on social interaction, organisational communication, and work conditions.
A Study of Automated Decision Making Systemsinventy
The decision making process of many operations are dependent on analysing very large data sets, previous decisions and their results. The information generated from the large data sets are used as an input for making decisions. Since the decisions to be taken in day to day operations are expanding, the time taken for manual decision making is also expanding. In order to reduce the time, cost and to increase the efficiency and accuracy, which are the most important things for customer satisfaction, many organisations are adopting the automated decision making systems. This paper is about the technologies used for automated decision making systems and the areas in which automated decisions systems works more efficiently and accurately.
Evaluation of Damage by the Reliability of the Traction Test on Polymer Test ...inventy
In recent decades, polymers have undergone a remarkable historical development and their use has been greatly imposed by gradually dethroning most of the secular materials. These polymer materials have always distinguished themselves by their simple shaping and inexpensive price, their versatility, lightness, and chemical stability but despite their massive use in everyday life as well as in advanced technologies. Generally, these materials still not understood which requires a thorough knowledge of their chemical, physical, rheological and mechanical properties. This paper, we study the mechanical behavior of an amorphous polymer: Acrylonitrile Butadiene Styrene “ABS” by means of uniaxial tensile testing on pierced test pieces with different notch lengths ranging between 1 to 14mm.The proposed approach consists in analyzing the evolution of the global geometry of the obtained strain curves by taking into account the zones and characteristic points of these curves as well as the effect of the damage on the mechanical behavior of the polymer ABS, in order to visualize the evolution of the damage by a static model
Application of Kennelly’model of Running Performances to Elite Endurance Runn...inventy
: The model of Kennelly between distance (Dlim) and exhaustion time (tlim) has been applied to the individual performances of 19 elite endurance runners (World-record holders and Olympic winners) from P. Nurmi (1920-1924) to M. Farah (2012) whose individual best performances on several different distances are known. Kennelly’s model (Dlim = k tlim ) can describe the individual performances of elite runners with a high accuracy (errors lower than 2 %). There is a linear relationship between parameters k and exponents of the elite runners and the extreme values correspond to S. Coe (k = 15.8; = 0.851) and E. Zatopek (k = 6.57; = 0.984). Exponent can be considered as a dimensionless index of aerobic endurance which is close to 1 in the best endurance runners. If it is assumed than maximal aerobic speed can be maintained 7 min in elite endurance runners, exponent is equal to the normalized critical speed (critical speed/maximal aerobic speed) computed from exhaustion times equal to 3 and 12.5 min in these runners.
Development and Application of a Failure Monitoring System by Using the Vibra...inventy
In this project, a failure monitoring system is developed by using the vibration and location information of balises in railway signaling. A lot of field equipment in railway are loosening and broken in time period so that they need maintenance due to the vibrations that occur due to high speed trains traffic and railway vehicles impact. Among the field equipment, balises have very important role of communication in terms of transmitting information to trains. In this scope, it is aimed to make maintenance works more efficient, have no delayed trains, detect previously failure location and intervene in failure timely, by detecting and controlling balise cases such as loosening, out of place and the data consistency error that happens because of balise physical state. In this project, the communication is provided with I2C, Modbus RTU (Remote Terminal Unit) and RS485 standards by using Arduino Uno cards and MPU6050 IMU (Inertial Measurement Unit) sensors in laboratory. Each used sensors are in slave mode and computer interface designed with C# is in master mode. Fault situations in the system are checked instant by the interface. (it is assumed to mount the IMU sensor and the Arduino circuit on the balise) it is seen that the interface responds to the sensor movements instant and the system works well in the end of test processes.
The Management of Protected Areas in Serengeti Ecosystem: A Case Study of Iko...inventy
This document summarizes a study that assessed the management of protected areas in Serengeti ecosystem, using Ikorongo and Grumeti Game Reserves as a case study. The study aimed to identify natural resource management strategies used, examine their impacts and hindrances, and identify ways to improve performance. It found that strategies have successfully reduced poaching by 96% and improved community relations. However, challenges remain like loss of life/property from wildlife conflicts and lack of access to water sources. The study concluded strategies have been fairly sustainable but need more participatory local approaches and benefit sharing to achieve collaborative management across the ecosystem. It recommended solutions like equitable benefit sharing, more funding, non-lethal deterrents, and strengthened
Size distribution and biometric relationships of little tunny Euthynnus allet...inventy
This study is taken from data of commercial fishing of the little tunny, Euthynnus alletteratus (Rafinesque, 1810) caught in the Algerian coast, sampled between november 2011 and april 2016. Data were collected in order to determine size distributions of the population and biometric relationships of species including the size - weight relationships. A total of 601 fish ranged from 30.9 and 103 cm fork length (FL) were observed. The size distribution of Euthynnus alletteratus shows multiple modal values witch the most important cohort corresponds to the age class 2 (42-46 cm). The value of the allometric coefficient (b) of the FL/TW relationship is lower than 3, indicating a negative allometric growth.
Removal of Chromium (VI) From Aqueous Solutions Using Discarded Solanum Tuber...inventy
Industrial polluting effluents containing heavy metals are of serious environmental concern in India. Chromium is frequently used in industries like electroplating, metal finishing, cooling towers, dyes, paints, anodizing and leather tanning and is found as traces in effluents finding their way to natural water bodies causing hazardous toxicity to the health of humans, animals and aquatic lives directly or indirectly. Many methods for the removal of Chromium such as chemical reduction, precipitation, ion exchange, electrochemical reduction, evaporation, reverse osmosis and adsorption using activated carbon etc. have been reported but all being expensive and complicated to operate. Experimental practices reveal that adsorption by agricultural and horticultural wastes are quite simple, inexpensive and efficient method. Agra is famous for Potato farming, a lot of discarded potato waste from cold storages is thrown along road side drains causing solid waste generated which either creates solid waste disposal problem or otherwise it finds way to Yamuna river resulting high BOD and posing a serious threat to the aquatic environment. For developing countries like India adsorption studies using discarded potato (Solanum tuberosum) waste from cold storages (DPWC) a solid waste as low cost adsorbent for Chromium removal was dual beneficial i.e., an ideal solution to these solid wastes disposal problem of Agra and removal of Chromium from tannery effluents and thereby saving aquatic life from Chromium contamination in Yamuna river. Keeping this in view batch experiments were designed to study the feasibility of discarded potato waste from cold storages to remove chromium (VI) from the aqueous solutions. During the study various affecting parameters, such as pH, adsorbent does, initial concentration, temperature, contact time, adsorbent grain size and start up agitation speed were optimized as 5.0, 10-20 g/l, 50 mg/l, 250C, 135 minutes, average size and 80 rpm respectively on chromium removal efficiency. Various Isotherms such as Langmuir, Freundlich, Tempkin also fitted suitably and various corresponding constants determined from these Isotherms favor and support the adsorption. Thermodynamic constants ∆G, ∆H and ∆S were found to be 0.267 KJ/mole, 0.288 KJ/mole and 0.0013 KJ/mole respectively.
Effect of Various External and Internal Factors on the Carrier Mobility in n-...inventy
The effect of various external (temperature, electric field, light) and intracrystalline (doping, initial resistivity) factors on the mobility of carriers in layered n-InSe semiconductor experimentally have been investigated. Scientific explanations of the results are proposed
Transient flow analysis for horizontal axial upper-wind turbineinventy
This study is to carry out a transient flow field analysis on the condition that the wind turbine is working to generate turbine, the wind turbine operating conditions change over time, Purpose of this study is try to find out the rule from the wind turbine changing over time . In transient analysis, the wind velocity on inlet boundary and rotation speed in the rotor field will change over time, and an analytical process is provided that can be used for future reference. At present, the wind turbine model is designed on the concept of upwind horizontal axis type. The computer engineering software GH Bladed is used to obtain the relationship between the rotor velocity and the wind turbine. Then the ANSYS engineering software is used to calculate the stress and strain distribution in the blades over time. From the analytical result, the relationship between the stress distribution in the blades and the rotor velocity is got to be used as a reference for future wind turbine structural optimization.
Choice of Numerical Integration Method for Wind Time History Analysis of Tall...inventy
Wind tunnel tests are being performed routinely around the world for designing tall buildings but the advent of powerful computational tools will make time-history analysis for wind more common in near future. As the duration of wind storms ranges from tens of minutes to hours while earthquake durations are typically less than a three to four minutes, the choice of a time step size (Δt) for wind studies needs to be much larger both to reduce the computational time and to save disk space. As the error in any numerical solution of the equation of motion is dependent on step size (Δt), careful investigations on the choice of numerical integration methods for wind analyses are necessary. From a wide variety of integration methods available, it was decided to investigate three methods that seem appropriate for 3D-time history analysis of tall buildings for wind. These are modal time history analysis, the Hilber-Hughes-Taylor (HHT) method or α-method with α=- 0.1, and the Newmark method with β=0.25 and γ=0.5 ( i.e., trapezoidal rule). SAP2000, a common structural analysis software tool, and a 64-story structure are used to conduct all the analyses in this paper. A boundary layer wind tunnel (BLWT) pressure time history measured at 120 locations around the building envelope of a similar structure is used for the analyses. Analyses performed with both the HHT and Newmark-method considering P-delta effects show that second order effects have a considerable impact on both displacement and acceleration response. This result shows that it is necessary to account P-delta effect for wind analysis of tall buildings. As the direct integration time history analysis required very large computation times and very large computer physical memory for a wind duration of hours, a modal analysis with reduced stiffness is considered as a good alternative. For that purpose, a non-linear static analysis of the structure with a load combination of 1.0D + 1.0L is performed in SAP2000 and the reduced stiffness of the structure after the analysis is used to conduct an eigenvalue analysis to extract the mode shapes and frequencies of this structure. Then the first 20- modes are used to perform a modal time history analysis for wind load. The result shows that the responses from modal analysis with “20-mode (reduced stiffness)” are comparable with that from the P-Δ analyses of Newmark-method
Impacts of Demand Side Management on System Reliability Evaluationinventy
This summary provides an overview of the impacts of demand side management (DSM) techniques on power system reliability in Saudi Arabia:
1. DSM techniques like load shifting can improve power system reliability by transferring load from peak to off-peak periods, reducing peak demand and allowing generators to operate more efficiently.
2. The study models load shifting and adding renewable energy sources to the Riyadh power system and calculates reliability indices like loss of load probability (LOLP) and expected energy not served (EENS) to analyze the impacts on reliability.
3. Preliminary results show load shifting can reduce peak demand and renewable energy from solar and wind can further contribute to reliability by providing generation during peak periods.
Reliability Evaluation of Riyadh System Incorporating Renewable Generationinventy
In this paper, the experience of Saudi Electricity Company (SEC) in analyzing the generation adequacy for Year 2013 is presented. This analysis is conducted by calculating several reliability indices for Riyadh system hourly load during all four seasonal periods. The reliability indices are gauged against the international utility practice. SEC also plans to introduce renewable energy into the network in order to secure the environmental standards and reduce fuel costs of conventional generation. Thus, the reliability improvement due to different integration levels of Solar and Wind generating sources has also been investigated. The capacity value provided by these variable renewable energy sources (VERs) to reliably meet the system load has been calculated using effective load carrying capability (ELCC) technique with a loss of load expectancy metric.
The effect of reduced pressure acetylene plasma treatment on physical charact...inventy
The capacitors are increasingly being used as energy storage devicesin various power systems. The scientists of the world are tryingto maximize the electrical capacity of the supercapacitors. To achieve this purpose, numerous method sare used: the surface activation of electrodes, the surface etching using the electronbeam, the electrode etching with variousgasplasma, etc. The purpose of this work is toresearch how the properties of carbon electrodes depend on the plasma parameters at whichtheywere formed. The largest surface area ofcarbonelectrodeof47.25m2 /gis obtainedat 15 ofAr/C2H2gasratio. Meanwhile, theSEMimages show that the disruption of structures with low bond energies and the formation of new onesare taking place when the carbon electrodes are etched at acetylene plasma and placed on carbon electrode. The measurements of capacitance showthat capacitors with affectedelectrodes have about10-15% highercapacity than those not treated with acetyleneplasma.
Experimental Investigation of Mini Cooler cum Freezerinventy
In general cases the refrigerator could be converted into an air conditioner by attaching a fan. Thus a cooler as well as freezer is obtained in a single set up. The freezer can be converted to an air conditioner when the outside air is allowed to flow beside the cooling coil and is forced outside by an exhaust fan. In this case a mini scale cooler cum freezer using R134a as refrigerant was fabricated and tested In our mini project work we had designed, fabricated and experimentally analysed a mini cooler cum freezer. From the observations and calculations, the results of mini cooler cum freezer are obtained and are compared.
Growth and Magnetic properties of MnGeP2 thin filmsinventy
We have successfully grown MnGeP2 thin films on GaAs (100) substrate. A ferromagnetic transition near 320 K has been observed by temperature dependent magnetization and resistance measurements. Field dependent magnetization experiments have shown that the coercive fields at 5, 250, and 300 K are 3870, 1380 and 155 Oe, respectively. Magnetoresistance and Hall measurements have displayed that hole conduction is dominant in MnGeP2. PACS: 75.50.Pp, 75.70.-i, 85.70.-w, 73.50.-h
Some Natural Herbs in India and Their Effectiveness in Water Purificationinventy
This document summarizes a study on the effectiveness of natural herbs in India for water purification. The study tested extracts from leaves and fruits of Ocimum Sanctum, Azadirachta indica, Triticum aestivum, Phyllanthus emblica, and Strychnos potatorum individually and in mixtures for their ability to remove E. coli bacteria from water. Testing showed that a 1% concentration of each herb extract was most effective at removing E. coli. Of the individual herbs, Ocimum Sanctum was the most effective at removing E. coli, with 82.15% removal observed. A mixture of Ocimum Sanctum, Azadirachta indica, and
Literature Review Basics and Understanding Reference Management.pptxDr Ramhari Poudyal
Three-day training on academic research focuses on analytical tools at United Technical College, supported by the University Grant Commission, Nepal. 24-26 May 2024
Presentation of IEEE Slovenia CIS (Computational Intelligence Society) Chapte...University of Maribor
Slides from talk presenting:
Aleš Zamuda: Presentation of IEEE Slovenia CIS (Computational Intelligence Society) Chapter and Networking.
Presentation at IcETRAN 2024 session:
"Inter-Society Networking Panel GRSS/MTT-S/CIS
Panel Session: Promoting Connection and Cooperation"
IEEE Slovenia GRSS
IEEE Serbia and Montenegro MTT-S
IEEE Slovenia CIS
11TH INTERNATIONAL CONFERENCE ON ELECTRICAL, ELECTRONIC AND COMPUTING ENGINEERING
3-6 June 2024, Niš, Serbia
Introduction- e - waste – definition - sources of e-waste– hazardous substances in e-waste - effects of e-waste on environment and human health- need for e-waste management– e-waste handling rules - waste minimization techniques for managing e-waste – recycling of e-waste - disposal treatment methods of e- waste – mechanism of extraction of precious metal from leaching solution-global Scenario of E-waste – E-waste in India- case studies.
Harnessing WebAssembly for Real-time Stateless Streaming PipelinesChristina Lin
Traditionally, dealing with real-time data pipelines has involved significant overhead, even for straightforward tasks like data transformation or masking. However, in this talk, we’ll venture into the dynamic realm of WebAssembly (WASM) and discover how it can revolutionize the creation of stateless streaming pipelines within a Kafka (Redpanda) broker. These pipelines are adept at managing low-latency, high-data-volume scenarios.
International Conference on NLP, Artificial Intelligence, Machine Learning an...gerogepatton
International Conference on NLP, Artificial Intelligence, Machine Learning and Applications (NLAIM 2024) offers a premier global platform for exchanging insights and findings in the theory, methodology, and applications of NLP, Artificial Intelligence, Machine Learning, and their applications. The conference seeks substantial contributions across all key domains of NLP, Artificial Intelligence, Machine Learning, and their practical applications, aiming to foster both theoretical advancements and real-world implementations. With a focus on facilitating collaboration between researchers and practitioners from academia and industry, the conference serves as a nexus for sharing the latest developments in the field.
Understanding Inductive Bias in Machine LearningSUTEJAS
This presentation explores the concept of inductive bias in machine learning. It explains how algorithms come with built-in assumptions and preferences that guide the learning process. You'll learn about the different types of inductive bias and how they can impact the performance and generalizability of machine learning models.
The presentation also covers the positive and negative aspects of inductive bias, along with strategies for mitigating potential drawbacks. We'll explore examples of how bias manifests in algorithms like neural networks and decision trees.
By understanding inductive bias, you can gain valuable insights into how machine learning models work and make informed decisions when building and deploying them.
Electric vehicle and photovoltaic advanced roles in enhancing the financial p...IJECEIAES
Climate change's impact on the planet forced the United Nations and governments to promote green energies and electric transportation. The deployments of photovoltaic (PV) and electric vehicle (EV) systems gained stronger momentum due to their numerous advantages over fossil fuel types. The advantages go beyond sustainability to reach financial support and stability. The work in this paper introduces the hybrid system between PV and EV to support industrial and commercial plants. This paper covers the theoretical framework of the proposed hybrid system including the required equation to complete the cost analysis when PV and EV are present. In addition, the proposed design diagram which sets the priorities and requirements of the system is presented. The proposed approach allows setup to advance their power stability, especially during power outages. The presented information supports researchers and plant owners to complete the necessary analysis while promoting the deployment of clean energy. The result of a case study that represents a dairy milk farmer supports the theoretical works and highlights its advanced benefits to existing plants. The short return on investment of the proposed approach supports the paper's novelty approach for the sustainable electrical system. In addition, the proposed system allows for an isolated power setup without the need for a transmission line which enhances the safety of the electrical network
We have compiled the most important slides from each speaker's presentation. This year’s compilation, available for free, captures the key insights and contributions shared during the DfMAy 2024 conference.
Advanced control scheme of doubly fed induction generator for wind turbine us...IJECEIAES
This paper describes a speed control device for generating electrical energy on an electricity network based on the doubly fed induction generator (DFIG) used for wind power conversion systems. At first, a double-fed induction generator model was constructed. A control law is formulated to govern the flow of energy between the stator of a DFIG and the energy network using three types of controllers: proportional integral (PI), sliding mode controller (SMC) and second order sliding mode controller (SOSMC). Their different results in terms of power reference tracking, reaction to unexpected speed fluctuations, sensitivity to perturbations, and resilience against machine parameter alterations are compared. MATLAB/Simulink was used to conduct the simulations for the preceding study. Multiple simulations have shown very satisfying results, and the investigations demonstrate the efficacy and power-enhancing capabilities of the suggested control system.
Advanced control scheme of doubly fed induction generator for wind turbine us...
Crystallization of L-Glutamic Acid: Mechanism of Heterogeneous β -Form Nucleation
1. Research Inventy: International Journal of Engineering And Science
Vol.7, Issue 1 (January 2017), PP -22-27
Issn (e): 2278-4721, Issn (p):2319-6483, www.researchinventy.com
22
Crystallization of L-Glutamic Acid: Mechanism of Heterogeneous
β -Form Nucleation
Khuu Chau Quang1,2
, Dang Truong Giang1
, Trinh Thi Thanh Huyen1
,
Nguyen Anh Tuan1,2
1
Institute of Chemical Technology, Vietnam Academy of Science & Technology (VAST), Vietnam
2
Graduate University of Science and Technology, Vietnam Academy of Science & Technology (VAST), Vietnam
Abstract: The mechanism of heterogeneous nucleation of β-form L-glutamic acid was deeply investigated in
cooling crystallization. The present study found that the β-form crystals were epitaxially grown on the α-form
crystals and they were preferably crystallized on the (011) and (001) surfaces instead of the (111) surfaces of α-
form crystals. This result was explained via the molecular simulation. The molecular simulation indicated that
the different surfaces of α-form crystals provided different functional groups, resulting in different sites for the
heterogeneous nucleation of β-form crystals. Here, the functional group were COO-
, C=O and O-H on the (011)
and (001) surfaces of α-form crystals, respectively, while it was the NH3
+
on the (111) surfaces of α-form
crystals. As such, the degree of lattice matching (E) between the β-form crystals and the various surfaces of α-
form crystal was distinguished, where the degree of lattice matching (E) between the β-form crystals and the
(011), (001) and (111) surfaces of α-form crystal were estimated as 5.30, 5.25 and 2.39, respectively, implying
that the (011) and (001) surfaces of α-form crystal were more favorable to generate the heterogeneous
nucleation of β-form crystals than the (111) surfaces of α-form crystal.
Keywords: crystallization, crystallography, crystal growth, nucleation, polymorphism.
I. Introduction
Crystallization is significant separation, purification and particle technology, which is widely used in
the life-science industries including pharmaceutical, food and agrochemicals [1-2]. In crystallization,
polymorphism is a very important and interested phenomenon, where the solid product can adopt more than one
crystal structure due to the different packing arrangement and conformation of molecules in the crystal lattice.
The different polymorphic solid forms exhibit a marked difference in the physical-chemical properties including
bio-availability, solubility, hardness, stability, etc. In the pharmaceutical industry, there are more than 90%
products commercialized in the solid forms, and at least 50% of these products has the polymorphism, meaning
that control of polymorphism becomes a vital issue in any pharmaceutical crystallization process [3-6].
Once the polymorphism can affect the quality, safety and efficacy of the pharmaceutical solid products,
the Food and Drug Administration (FDA) in US requires all the pharmaceutical company to submit the approval
of a new drug application as if this drug has the polymorphic forms. Also, the FDA has provided a detail of the
tree recommendation in order to monitor and control polymorphic pharmaceutical products. In present study, the
amino acid L-glutamic acid was chosen as a model crystal product to demonstrate the control of polymorphism
in crystallization. Here, the amino acid L-glutamic acid has widely applied in all the food and pharmaceutical
industry, where it has two kinds of polymorphism including metastable α-form and stable β-form crystal. In the
L-glutamic acid crystallization, the polymorphic nucleation phenomenon is very complicated and elusive
because it depends on many crystallization conditions. For example, Lai et al [7] indicated that the α-form
nucleation was facilitated at low temperature of 250
C, while the β-form nucleation was promoted at high
temperature of 450
C in the continuous MSMPR crystallizer. In order to increase the recovery of β-form crystal
product at low temperature of 250
C, Florence et al [8] reported that the seeding technique was really effective as
using the continuous Oscillatory baffles crystallizer (OBC). Recently, Tahri et al [9] revealed that the nucleation
of α-form and β-form crystal were both generated in the stirred condition, while the only β-form nucleation was
performed under the stagnant condition, meaning that the agitation condition was also important since it
impacted on the polymorphic nucleation of L-glutamic acid, etc.
In contrast to previous study, our current work investigated the mechanism of heterogeneous nucleation
of β-form L-glutamic acid in the stirred cooling crystallization, which was not fully described in the previous
studies. As such, the mechanism of polymorphic nucleation L-glutamic acid in stirred cooling crystallization
would be more understood. In addition, although the crystallization research is very common in the developed
countries such as USA, EU, Japan, Korea, China, India, Singapore, etc, it is still limited in the South and East
Asian countries including Vietnam, Indonesia, Philippine, Malaysia, etc [10-11], meaning that the crystallization
research should be developed in these countries.
2. Crystallization Of L-Glutamic Acid: Mechanism Of Heterogeneous β -Form Nucleation
23
II. Experimental
L-glutamic acid material (>98% purity) was bought from Sigma Aldrich company and the feed solution
was prepared by dissolving material into the distilled water at 700
C. The standard stirred tank crystallizer with
400 ml working volume was designed by Nguyen et al [4-6]. Initially, the stirred tank crystallizer was fully
filled with feed solution at concentration of 40 (g/L) and then operated as the batch mode cooling crystallization
at cooling rate of 6.0 (0
C/min) and agitation speed of 300rpm. The temperature of crystallizer was controlled via
the circulating coolant from the chiller. The suspension products were periodically taken from the crystallizers
and quickly filtered by using a vacuum pump. The crystal samples were then dried in a desiccator and analyzed
to define properties of products including the shape, structure and crystal fraction of α-form and -form. Here,
the shape and structure of crystal product were monitored and confirmed by Video microscope and XRD
patterns (M18XHF-SRA, Japan), respectively, while the crystal fraction was estimated by the FTIR
spectroscopy (Perkin Elmer, System 2000 FT-IR, U.S.A.). The molecular simulation was carried out via the
crystallographic software including Encifer, Mercury, Diamon and GRACE.
III. Results And Discussions
1. Polymorphism of α-form and β-form crystal product: The morphology of α-form and β-form crystals was
clearly different via the prism shape of α-form and needle shape of β-form crystal, respectively, as shown in
Figure 1. Moreover, the crystal structure of two polymorphs was distinguished via the characteristic peaks at
100
, 150
, 160
, 180
, 210
, 230
, 26.50
, 27.50
degrees of XRD pattern, as depicted in Figure 2.
Figure 1. Morphology of α-form and β-form crystal product
Therefore, L-glutamic acid has two kinds of polymorphism including α-form and β-form crystal. For a
deeper insight into differences of crystal structure, the crystallography of two polymorphs was studied. Here, the
parameters and position of each atom of unit cell were obtained from the previous studies [12-13], and then
coded via the Encifer software. The conformation and packing of L-glutamic acid molecules in unit cell were
simulated via the Mercury and Diamon software. As shown in Figure 3, the conformation of molecule L-
glutamic acid in α-form crystal was different from that of β-form crystal. For instance, the O(1)-C(1)-C(2)-N
torsional angles were -50.41 in the α-form, while they were -42.26 in the β-form. Furthermore, although the
crystal system and number of molecules in a unit cell of two polymorphs are orthorhombic with space group
P212121 and Z=4, respectively, the unit cell parameters and packing of molecules of two polymorphs were
definitely distinguished. Here, the unit cell parameters of α-form crystal were a = 7.068, b = 10.277, c = 8.755
Å, while those of β-form crystal were a = 5.159, b = 17.300, c = 6.948 Å, as depicted in Figure 4. Plus, the
different packing of molecules of two polymorphs was clearly recognized at the “c” and “a” direction, as shown
in Figure 4.
Figure 2. Crystal structure of α-form and β-form crystal product
3. Crystallization Of L-Glutamic Acid: Mechanism Of Heterogeneous β -Form Nucleation
24
Figure 3. Conformation of molecules in α-form and β-form crystal product
Figure 4. Packing of molecules in “c” and “a” direction in unit cell of α-form and β-form crystal product
2. Heterogeneous nucleation of β-form crystal product: In L-glutamic acid cooling crystallization, the
metastable phase α-form crystal was initially crystallized and then completely transformed into the stable phase
β-form crystal after a crystallization time of 40 hours [14]. As such, it took a long time to complete the phase
transformation from α-form to β-form crystal. Based on our previous study [14], the phase transformation of α-
form to β-form crystal should be significantly promoted if the nucleation of β-form crystal was accelerated. In
addition, it is well known that the heterogeneous nucleation is dominant in the stirred industrial crystallization
due to the sweep of fluid hydrodynamic on the surface of mother crystal and collision between crystal and
crystal, crystal and crystallizer’s wall, crystal and impeller, etc. Thus, the mechanism of heterogeneous
nucleation of β-form was certainly important and should be deeply investigated in the stirred cooling
crystallization of L-glutamic acid. As shown in Figure 5, the heterogeneous nucleation of β-form crystal was
obviously occurred and epitaxially grown on the surfaces of α-form crystal, meaning that the surfaces of α-form
crystal were considered as the substrate to generate the heterogeneous nucleation of β-form crystal. This result
was expected in terms of a low free energy barrier of the substrate in order to generate the heterogeneous
nucleation [1-2]. However, the favorable site for the heterogeneous nucleation of β-form on a specific surface of
α-form crystal was not fully understood in the stirred cooling crystallization of L-glutamic acid. Thus, in present
study, the formation of heterogeneous nucleation of β-form on a specific surface of α-form crystal was
investigated. Since the epitaxial growth of β-form molecules on a specific surface of α-form crystal directly
depended on the functional group of molecules oriented on the surfaces of α-form, the distinguished functional
group of molecules on each α-form surface should be clearly clarified. As shown in Figure 6, the various
surfaces of α-form crystal including (011), (001) and (111) and the heterogeneous nucleation of β-form possibly
occurred on these surfaces were estimated via the (hkl) Miller planes method [1-2].
4. Crystallization Of L-Glutamic Acid: Mechanism Of Heterogeneous β -Form Nucleation
25
Figure 5. Heterogeneous nucleation of β-form occurred on surface of α-form crystal
Figure 6. Schematic heterogeneous nucleation of β-form possibly occurred on the different surfaces of α-form
crystal
The functional group of L-glutamic acid molecules oriented on the surface of α-form crystal was
estimated via the Diamon software, as displayed in Figure 7. This result showed that there was a significant
difference of functional group on three surfaces, in which the functional group including C=O, O-H and COO-
appeared on the (001) and (011) surfaces, respectively, while it was NH3
+
on the (111) surface. As such, the
different functional groups on the surfaces of α-form crystal might provide distinguished sites for the
heterogeneous nucleation of β-form crystal. This hypothesis was concreted by the different degree of lattice
5. Crystallization Of L-Glutamic Acid: Mechanism Of Heterogeneous β -Form Nucleation
26
matching (E) between the β-form molecules aggregate and a specific surface of α-form crystal, where the degree
of lattice matching (E) was estimated via the GRACE software with varied azimuth angles from -900
to 900
degree and a search area of 100A0
x 100A0
[15]. As shown in Figure 8, the result showed that the prominent
peaks of (001) and (011) surfaces were both appeared at = 900
, while the characteristic peak of (111) surfaces
was observed at = 150
. Plus, the degrees of lattice matching E of (011), (001) and (111) surfaces were
calculated as 5.30, 5.25 and 2.39, respectively, meaning that the (011) and (001) surface were more favorable
site for the heterogeneous nucleation of β-form crystal compared to the (111) surfaces of α-form crystal. This
result was consistent with the experimental result as illustrated in Figure 5, where the needle shape of β-form
crystal was predominant on the (011) and (001) surface instead of the (111) surfaces of α-form crystal.
Figure 7. Different functional group oriented on the various surfaces of α-form crystal
Figure 8. Lattice matching (E) between β-form molecules and the surface of α-form crystal
IV. Conclusions
The present study provided a proposed mechanism of heterogeneous nucleation of β-form L-glutamic
acid in the stirred cooling crystallization. Here, the heterogeneous nucleation of β-form was preferably
performed on the (011) and (001) surfaces of α-form crystal instead of the (111) surfaces at feed concentration
of 40 (g/L) and agitation speed of 300 rpm. This result was successfully explained via the molecular simulation,
where the molecular simulation result showed that the functional group of molecules on the (011) and (001)
surfaces were COO-
, C=O and O-H, respectively, while it was the NH3
+
on the (111) surface of α-form crystals.
Thus, the degree of lattice matching (E) between the β-form crystal and surfaces of α-form crystal was certainly
distinguished. Here, the degrees of lattice matching (E) between the β-form crystal and the (011), (001) and
(111) surfaces of α-form crystal were estimated as 5.30, 5.25 and 2.39, respectively, meaning that the (011) and
(001) surfaces of α-form crystal were the more favorable place for generating the heterogeneous nucleation of β-
form crystal in the stirred cooling crystallization of L-glutamic acid.
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