This presentation gives a summary of work carried out in the Chemical Engineering Department at Cambridge on the rheology and processing of ink jet fluids. The linear viscoelastic properties are captured using a PAV rheometer and the non linear extensional behaviour using a "Cambridge Trimaster".
The Cambridge Multipass Rheometer (MPR) is capable of performing rheology measurements under varied temperature, pressure, flow, and time conditions. It has four models that can impose temperature from -10 to 210°C, pressure from 1 to 200 bar, flow from 1 to 100,000 reciprocal seconds, and time from milliseconds to hours. The MPR uses enclosed volumes and interchangeable inserts to perform experiments in different flow modes like pressure variation, flow curves, and cross-slot flow. It has been used to study materials like polymers, foods, foams and other complex fluids.
This presentation was given in Cardiff at the European Society of Rheology Conference in 2009. The presentation is about research in "extreme" areas of rheology and includes work on measuring the viscoelasticity of low viscosity fluids and the limiting extensional viscosity of high viscosity fluids.
This document summarizes experimental work validating numerical simulations of precise polymer melt processing using the Cambridge Multipass Rheometer (MPR). [1] The MPR was used to perform slit flow and cross-slot flow experiments on polymer melts like polystyrene. [2] Both the Pom-Pom and Rolie-Poly constitutive models were able to simulate the rheology and match experimental pressure drop and flow patterns when appropriate relaxation spectra and nonlinear parameters were used. [3] The validation demonstrates the ability of numerical simulation to accurately model complex viscoelastic flows.
This presentation is for my last Cambridge Rheology course lecture. The presentation links course work with research that had been carried out in the Department. The presentation has been modified a little to aid web clarity.
This document discusses slurry conveying systems used in mining applications to transport mining waste and concentrates. It covers Newtonian slurries characterized by small particle sizes and low concentrations. Key aspects summarized include rheological models for viscosity, methods for calculating settling velocity, and steps to design a slurry transport system, including characterizing flows, determining pipe diameter, head losses, and pump selection. Slurry transport is affected by particle size, concentration, and pipe diameter, with minimum flow rates defined by settling velocity limits.
The Cambridge Multipass Rheometer (MPR) is capable of performing rheology measurements under varied temperature, pressure, flow, and time conditions. It has four models that can impose temperature from -10 to 210°C, pressure from 1 to 200 bar, flow from 1 to 100,000 reciprocal seconds, and time from milliseconds to hours. The MPR uses enclosed volumes and interchangeable inserts to perform experiments in different flow modes like pressure variation, flow curves, and cross-slot flow. It has been used to study materials like polymers, foods, foams and other complex fluids.
This presentation was given in Cardiff at the European Society of Rheology Conference in 2009. The presentation is about research in "extreme" areas of rheology and includes work on measuring the viscoelasticity of low viscosity fluids and the limiting extensional viscosity of high viscosity fluids.
This document summarizes experimental work validating numerical simulations of precise polymer melt processing using the Cambridge Multipass Rheometer (MPR). [1] The MPR was used to perform slit flow and cross-slot flow experiments on polymer melts like polystyrene. [2] Both the Pom-Pom and Rolie-Poly constitutive models were able to simulate the rheology and match experimental pressure drop and flow patterns when appropriate relaxation spectra and nonlinear parameters were used. [3] The validation demonstrates the ability of numerical simulation to accurately model complex viscoelastic flows.
This presentation is for my last Cambridge Rheology course lecture. The presentation links course work with research that had been carried out in the Department. The presentation has been modified a little to aid web clarity.
This document discusses slurry conveying systems used in mining applications to transport mining waste and concentrates. It covers Newtonian slurries characterized by small particle sizes and low concentrations. Key aspects summarized include rheological models for viscosity, methods for calculating settling velocity, and steps to design a slurry transport system, including characterizing flows, determining pipe diameter, head losses, and pump selection. Slurry transport is affected by particle size, concentration, and pipe diameter, with minimum flow rates defined by settling velocity limits.
This document describes a simulation tool for efficiently modeling general adsorption cycles. The tool uses a finite volume method to discretize the gas phase and an orthogonal collocation method to discretize the solid phase. It solves the resulting differential algebraic equations using a robust solver to accelerate convergence to cyclic steady state. The tool allows fast simulation of adsorption processes, which are complex multiphysics problems, to aid in experimental analysis and process optimization.
Separation of Macromolecules by Their Size: The Mean Span Dimensioncypztm
Size Exclusion Chromatograpphy (SEC, also called GPC) separates polymer molecules by their size in dilute solution, but which size parameter to use has been a matter of debate. This presentation contains a brief summary of our work on this problem.
Structural Design of 38 m Special Purpose Vessel in Aluminium AlloyMurat TOSUN
The general objective of the thesis is to carry out the structural design process of a high speed special purpose vessel which is a supply unit for offshore platforms, suitable for transporting technical personnel, cargo on deck and liquid cargo: fresh water and gasoil with a flash point above 60°C.
The design is developed in Rodriquez Cantieri Navali Spa. which has good experience with aluminium alloy vessels. Although the thesis aims to investigate the structural design of the vessel, it is needed to follow from preliminary design stages by providing its main particulars, hull form, capacity plan, stability analysis as well as the general arrangement.
The document describes a computational study conducted by Ignasi Buch to model the binding process of the ligand benzamidine to the enzyme bovine beta-trypsin. Hundreds of all-atom molecular dynamics simulations were performed to simulate the free ligand binding. The data was analyzed using a Markov state model to describe the system as a network of conformational substates and transitions between them. This allowed quantitative prediction of experimental binding kinetics and a qualitative description of the binding mechanism.
This document summarizes a simulation of a steam coal gasifier using computational fluid dynamics (CFD) and plug flow modeling approaches. The CFD model tracks the fluid and particle phases using mass and momentum equations, while the plug flow model uses a material balance. Results show reasonable agreement between the models in predicting effluent concentrations. The plug flow model allows for faster investigation of a wider range of conditions, while CFD provides more detailed hydrodynamic insights but requires more time to set up and run. Both methods provide complementary understanding of gasifier performance.
This document provides an introduction to techniques for compensating for solidification shrinkage in castings. It outlines seven rules for designing effective feeder systems:
1) The feeder must solidify at the same time or later than the casting (Chvorinov's rule).
2) The feeder must contain sufficient liquid to satisfy the volume contraction of the casting.
3) The junction between the casting and feeder must not create a hot or cold spot.
4) There must be a path for feed metal to reach all parts of the casting.
5) The feeder design must consider pressure requirements.
6) There must be an appropriate pressure gradient in the feed
The document summarizes a resilient modulus model developed for unbound pavement layers that accounts for the effects of moisture, stress state, and freezing/thawing. Key aspects include:
- A "universal" resilient modulus model relates MR to confining pressure, deviator stress, and moisture.
- MR decreases nonlinearly with increased moisture content according to sigmoid curves developed for coarse-grained and fine-grained materials.
- Freezing/thawing is modeled using adjustment factors based on material type and season to account for very high or reduced modulus.
- The model is implemented in the Mechanistic-Empirical Pavement Design Guide to predict seasonal variations in MR at the node and layer
1) NMR-diffusometry was used to study the structure and fluid mobility inside polymeric multilayer membranes.
2) Diffusion decays and time-dependent diffusion coefficients were measured for porous PA-6, PEI/PAAc multilayers, and PEI/PAAc multilayers produced in NaCl solution.
3) Pore sizes were estimated between 4.2-5.8 μm for the different materials. Molecular exchange between water in pores and outside pores was observed for PA-6 but not for PEI/PAAc multilayers.
This document summarizes a multiphysics simulation of a packed bed reactor. It presents the reactor geometry, kinetic reaction models, and approaches taken for both lumped and heterogeneous models. Results shown include temperature distributions, average temperature and conversion profiles along the reactor length, as well as conversions for specific segments. The conclusion suggests further modeling to study hot spots near the inlet and potential intra-pellet heat transfer effects.
The document provides information about the tables of information and equation tables that will be provided to students taking the AP Physics exams. It notes that students cannot bring their own copies to the exam but can use them in their classes. It describes the contents and organization of the tables, including defining symbols, explaining conventions used, and listing some equations that are not included. The tables are identical for Physics B and C exams except where noted.
This document is an exam paper for the Cambridge International Examinations (CIE) Physics A-Level exam. It consists of multiple choice and structured questions related to various physics concepts. The first question provides measurements for a metal wire sample and asks students to identify the instruments used, calculate resistivity, and determine uncertainty. The second question defines work done and shows a diagram of a car traveling downhill, providing information about its mass and the road's angle.
The summary identifies the source as a physics exam from CIE, provides an overview of the types of questions asked (multiple choice and structured), and briefly summarizes the key details and tasks required by the first two questions. It does so in 3 sentences as requested,
This experiment investigates how the concentration of hydrochloric acid (HCl) affects the conductivity when zinc is added. Five trials were conducted with varying molar concentrations of HCl (4M, 2M, 1M, 0.5M, and 0.25M) and the conductivity was measured over time. The results show that conductivity decreases more slowly at lower HCl concentrations. Specifically, the conductivity rate decreases from 2.532 μS/cm/s for 4M HCl to 3.425 μS/cm/s for 0.25M HCl. Thus, lower HCl concentrations lead to smaller decreases in conductivity over time when zinc is added.
This document summarizes NMR measurements on core plugs from an iron-rich, glauconitic sandstone reservoir in Australia that showed the mineral iron content affected NMR T2 relaxation times. Capillary pressure measurements showed the standard 30 msec T2 cutoff needed to be lowered to calibrate irreducible water saturation from NMR. Although iron affected T2 distributions, permeability could still be estimated accurately from NMR. High iron content (3-31% glauconite, 1-17% total iron) in this reservoir raised concerns about NMR surface relaxation effects.
This document summarizes an experimental study on the evolution of turbulent patches in dilute polymer solutions. Key findings include:
1) Polymer solutions resulted in a smoother turbulent/non-turbulent interface compared to water, with lower flow length scales and consistently lower entrainment rates.
2) Inside the turbulent patches, polymer solutions exhibited higher kinetic energy densities compared to water.
3) Future work is planned using 3D particle tracking velocimetry to further validate results and provide more insight into the interface dynamics.
This summary provides the key insights from the quantum mechanical analysis of donor-acceptor interactions in organometallic complexes:
1) Calculated parameters for bidentate phosphine ligands, such as the CO stretching frequency and H-H distance in nickel complexes, followed trends similar to unidentate phosphine ligands and provided insight into electronic and structural properties.
2) Electron donating phosphine ligands increased π-backbonding in nickel-dihydrogen complexes, lengthening the H-H bond, while electron withdrawing ligands increased σ-donation, shortening the H-H bond.
3) Calculations showed that a methane tautomer could be stabilized relative to a methyl hydride t
This document discusses different types and measurements of porosity in geological formations. It defines total, effective, isolated, macro, and micro porosities based on specific criteria. It introduces the concept of "producible porosity," which refers to the interconnected pore volume that contains movable fluids like water and hydrocarbons, excluding irreducible water trapped by capillary forces or bound to clay. The document examines how total porosity measured by well logs can overestimate core porosity measurements in shaley formations, and describes using mineralogical models to more accurately calculate total porosity from logs.
This document discusses plastics and polyethylene (PE) specifically. It notes that while plastics are fantastic due to their diverse uses, low production costs, and material properties, they also have environmental downsides when not disposed of properly. PE has a wide range of microstructures that give it varying properties and uses. It is one of the world's largest commodities, with over 80 million tonnes produced annually for a huge diversity of applications. However, plastic waste in the environment is a current issue that requires better recycling and disposal practices.
This was my last Departmental seminar given in Chemical Engineering at Cambridge. It tells the story of apparatus and process invention. I have included pictures that influenced my career.
NYSAS Solid State Spectroscopy Of Materials (Polymorphism)Mark_Sullivan
This document discusses polymorphism in solid-state materials and spectroscopy techniques for characterizing polymorphs. It provides examples of polymorphic drugs and outlines the importance of identifying and quantifying polymorphs. Techniques like FTIR, Raman, terahertz spectroscopy, solid-state NMR, and vibrational spectroscopy combined with multivariate analysis can be used to distinguish, identify, and quantify polymorphs in materials. Understanding polymorphism is crucial for developing drugs and ensuring consistent quality and performance throughout development and commercialization.
This document describes a simulation tool for efficiently modeling general adsorption cycles. The tool uses a finite volume method to discretize the gas phase and an orthogonal collocation method to discretize the solid phase. It solves the resulting differential algebraic equations using a robust solver to accelerate convergence to cyclic steady state. The tool allows fast simulation of adsorption processes, which are complex multiphysics problems, to aid in experimental analysis and process optimization.
Separation of Macromolecules by Their Size: The Mean Span Dimensioncypztm
Size Exclusion Chromatograpphy (SEC, also called GPC) separates polymer molecules by their size in dilute solution, but which size parameter to use has been a matter of debate. This presentation contains a brief summary of our work on this problem.
Structural Design of 38 m Special Purpose Vessel in Aluminium AlloyMurat TOSUN
The general objective of the thesis is to carry out the structural design process of a high speed special purpose vessel which is a supply unit for offshore platforms, suitable for transporting technical personnel, cargo on deck and liquid cargo: fresh water and gasoil with a flash point above 60°C.
The design is developed in Rodriquez Cantieri Navali Spa. which has good experience with aluminium alloy vessels. Although the thesis aims to investigate the structural design of the vessel, it is needed to follow from preliminary design stages by providing its main particulars, hull form, capacity plan, stability analysis as well as the general arrangement.
The document describes a computational study conducted by Ignasi Buch to model the binding process of the ligand benzamidine to the enzyme bovine beta-trypsin. Hundreds of all-atom molecular dynamics simulations were performed to simulate the free ligand binding. The data was analyzed using a Markov state model to describe the system as a network of conformational substates and transitions between them. This allowed quantitative prediction of experimental binding kinetics and a qualitative description of the binding mechanism.
This document summarizes a simulation of a steam coal gasifier using computational fluid dynamics (CFD) and plug flow modeling approaches. The CFD model tracks the fluid and particle phases using mass and momentum equations, while the plug flow model uses a material balance. Results show reasonable agreement between the models in predicting effluent concentrations. The plug flow model allows for faster investigation of a wider range of conditions, while CFD provides more detailed hydrodynamic insights but requires more time to set up and run. Both methods provide complementary understanding of gasifier performance.
This document provides an introduction to techniques for compensating for solidification shrinkage in castings. It outlines seven rules for designing effective feeder systems:
1) The feeder must solidify at the same time or later than the casting (Chvorinov's rule).
2) The feeder must contain sufficient liquid to satisfy the volume contraction of the casting.
3) The junction between the casting and feeder must not create a hot or cold spot.
4) There must be a path for feed metal to reach all parts of the casting.
5) The feeder design must consider pressure requirements.
6) There must be an appropriate pressure gradient in the feed
The document summarizes a resilient modulus model developed for unbound pavement layers that accounts for the effects of moisture, stress state, and freezing/thawing. Key aspects include:
- A "universal" resilient modulus model relates MR to confining pressure, deviator stress, and moisture.
- MR decreases nonlinearly with increased moisture content according to sigmoid curves developed for coarse-grained and fine-grained materials.
- Freezing/thawing is modeled using adjustment factors based on material type and season to account for very high or reduced modulus.
- The model is implemented in the Mechanistic-Empirical Pavement Design Guide to predict seasonal variations in MR at the node and layer
1) NMR-diffusometry was used to study the structure and fluid mobility inside polymeric multilayer membranes.
2) Diffusion decays and time-dependent diffusion coefficients were measured for porous PA-6, PEI/PAAc multilayers, and PEI/PAAc multilayers produced in NaCl solution.
3) Pore sizes were estimated between 4.2-5.8 μm for the different materials. Molecular exchange between water in pores and outside pores was observed for PA-6 but not for PEI/PAAc multilayers.
This document summarizes a multiphysics simulation of a packed bed reactor. It presents the reactor geometry, kinetic reaction models, and approaches taken for both lumped and heterogeneous models. Results shown include temperature distributions, average temperature and conversion profiles along the reactor length, as well as conversions for specific segments. The conclusion suggests further modeling to study hot spots near the inlet and potential intra-pellet heat transfer effects.
The document provides information about the tables of information and equation tables that will be provided to students taking the AP Physics exams. It notes that students cannot bring their own copies to the exam but can use them in their classes. It describes the contents and organization of the tables, including defining symbols, explaining conventions used, and listing some equations that are not included. The tables are identical for Physics B and C exams except where noted.
This document is an exam paper for the Cambridge International Examinations (CIE) Physics A-Level exam. It consists of multiple choice and structured questions related to various physics concepts. The first question provides measurements for a metal wire sample and asks students to identify the instruments used, calculate resistivity, and determine uncertainty. The second question defines work done and shows a diagram of a car traveling downhill, providing information about its mass and the road's angle.
The summary identifies the source as a physics exam from CIE, provides an overview of the types of questions asked (multiple choice and structured), and briefly summarizes the key details and tasks required by the first two questions. It does so in 3 sentences as requested,
This experiment investigates how the concentration of hydrochloric acid (HCl) affects the conductivity when zinc is added. Five trials were conducted with varying molar concentrations of HCl (4M, 2M, 1M, 0.5M, and 0.25M) and the conductivity was measured over time. The results show that conductivity decreases more slowly at lower HCl concentrations. Specifically, the conductivity rate decreases from 2.532 μS/cm/s for 4M HCl to 3.425 μS/cm/s for 0.25M HCl. Thus, lower HCl concentrations lead to smaller decreases in conductivity over time when zinc is added.
This document summarizes NMR measurements on core plugs from an iron-rich, glauconitic sandstone reservoir in Australia that showed the mineral iron content affected NMR T2 relaxation times. Capillary pressure measurements showed the standard 30 msec T2 cutoff needed to be lowered to calibrate irreducible water saturation from NMR. Although iron affected T2 distributions, permeability could still be estimated accurately from NMR. High iron content (3-31% glauconite, 1-17% total iron) in this reservoir raised concerns about NMR surface relaxation effects.
This document summarizes an experimental study on the evolution of turbulent patches in dilute polymer solutions. Key findings include:
1) Polymer solutions resulted in a smoother turbulent/non-turbulent interface compared to water, with lower flow length scales and consistently lower entrainment rates.
2) Inside the turbulent patches, polymer solutions exhibited higher kinetic energy densities compared to water.
3) Future work is planned using 3D particle tracking velocimetry to further validate results and provide more insight into the interface dynamics.
This summary provides the key insights from the quantum mechanical analysis of donor-acceptor interactions in organometallic complexes:
1) Calculated parameters for bidentate phosphine ligands, such as the CO stretching frequency and H-H distance in nickel complexes, followed trends similar to unidentate phosphine ligands and provided insight into electronic and structural properties.
2) Electron donating phosphine ligands increased π-backbonding in nickel-dihydrogen complexes, lengthening the H-H bond, while electron withdrawing ligands increased σ-donation, shortening the H-H bond.
3) Calculations showed that a methane tautomer could be stabilized relative to a methyl hydride t
This document discusses different types and measurements of porosity in geological formations. It defines total, effective, isolated, macro, and micro porosities based on specific criteria. It introduces the concept of "producible porosity," which refers to the interconnected pore volume that contains movable fluids like water and hydrocarbons, excluding irreducible water trapped by capillary forces or bound to clay. The document examines how total porosity measured by well logs can overestimate core porosity measurements in shaley formations, and describes using mineralogical models to more accurately calculate total porosity from logs.
This document discusses plastics and polyethylene (PE) specifically. It notes that while plastics are fantastic due to their diverse uses, low production costs, and material properties, they also have environmental downsides when not disposed of properly. PE has a wide range of microstructures that give it varying properties and uses. It is one of the world's largest commodities, with over 80 million tonnes produced annually for a huge diversity of applications. However, plastic waste in the environment is a current issue that requires better recycling and disposal practices.
This was my last Departmental seminar given in Chemical Engineering at Cambridge. It tells the story of apparatus and process invention. I have included pictures that influenced my career.
NYSAS Solid State Spectroscopy Of Materials (Polymorphism)Mark_Sullivan
This document discusses polymorphism in solid-state materials and spectroscopy techniques for characterizing polymorphs. It provides examples of polymorphic drugs and outlines the importance of identifying and quantifying polymorphs. Techniques like FTIR, Raman, terahertz spectroscopy, solid-state NMR, and vibrational spectroscopy combined with multivariate analysis can be used to distinguish, identify, and quantify polymorphs in materials. Understanding polymorphism is crucial for developing drugs and ensuring consistent quality and performance throughout development and commercialization.
1) In 1969, Prof. Albert Pennings discovered that Taylor vortices in Couette flow could induce elongated "shish kebab" crystal fibers of polyethylene from solution.
2) Also in 1969, Sir Charles Frank concluded that polyethylene could have a Young's modulus of 210 GPa if the chains were all aligned based on its similarity to diamond's unit cell structure.
3) In the 1970s, Frank and Mackley's experiments using opposed jets showed localized chain extension and "shish kebab" crystal formation, but with low overall modulus.
Web- Liquid Crytals and Liquid Crystal Polymers-2015malcolmmackley
The document discusses liquid crystals (LCs) and liquid crystal polymers (LCPs). LCs are formed from small, semi-rigid rod-like molecules that have liquid-like properties but local molecular ordering, giving them useful optical properties. LCPs, discovered in the 1970s, are made from semi-rigid polymer chains and similarly have local anisotropy and birefringence. The document focuses on "disclination" line defects that occur in both LCs and LCPs, influencing their overall orientation. Micrographs show various disclination textures in thermotropic LCPs under different conditions. While LCPs have locally ordered structures, controlling the disclination defect texture across the whole
This presentation gives a summary of how Polyethylene (PE). can crystallise from solution and the melt. The crystallisation of PE is both remarkable and very beautiful. The way PE crystallises is very important in relation to the properties of PE plastic bags, extrusions and high modulus PE fibres.
liquid crystals and their applicationsMinhas Azeem
This document discusses liquid crystals, their properties, types, and applications. It describes how liquid crystals have properties between solids and liquids, with some degree of molecular order. The main types discussed are thermotropic and lyotropic liquid crystals. Thermotropic liquid crystals change phase based on temperature, while lyotropic crystals depend on temperature, concentration, and solvent. Common applications mentioned include digital watches, phones, displays, and electronic devices that take advantage of liquid crystals' response to electric fields.
The document discusses liquid crystals and liquid crystal polymers. It notes that liquid crystals have properties between solids and liquids, with some positional and orientational order. They can exist in nematic, smectic, and cholesteric phases. Liquid crystal phases are important in biological systems like cell membranes and the brain. Liquid crystal polymers are highly resistant to heat and chemicals. They have applications in displays, body armor like Kevlar, and as heat sensors.
Evidence Of Bimodal Crystallite Size Distribution In Microcrystalline Silico...Sanjay Ram
It is known that there is a bimodal size distribution in microcrystalline silicon. How can the deconvolution of the Raman spectra be done with incorporation of a bimodal CSD to obtain more accurate and physical picture of the microstructure in this material?
The document provides information on the dimensions and performance of Kaplan turbines, including diagrams showing dimensions such as diameter, blade height and spacing for turbines in Nigeria and Chile. It also contains graphs depicting hydraulic efficiency and cavitation effects in relation to parameters like speed and blade angle. The example calculation at the end demonstrates how to determine the diameter, blade height and number of vanes given design criteria like power output, head and flow rate.
1. Analyze the ki data for Materials A and B to identify trends between dry, optimum and wet conditions
2. Develop MR prediction models for each material as a function of moisture content using the ki data
3. Validate the models against additional test data to confirm their accuracy in predicting MR values
The document discusses an approach to measuring the electric dipole moment (EDM) of the neutron. It aims to increase the statistical sensitivity to below 10-27 e·cm and systematic sensitivity to below 10-27 e·cm through several methods including increasing UCN density, using a buffer gas to suppress nuclear spin relaxation, using a spherical coil geometry, and implementing various shielding techniques. It also acknowledges collaborators from other institutions. The key ideas are to measure the neutron EDM through Ramsey's method of separated oscillatory fields in a static electric field, and to improve statistical and systematic uncertainties through technical upgrades and experimental design choices.
Field-flow fractionation (AF4) is a separation technique that uses an external cross-flow to fractionate samples based on differences in size, shape, or density. In AF4, an analyte mixture is injected into a thin channel and separated under the influence of a perpendicular laminar flow. Smaller analytes are eluted faster than larger ones. AF4 coupled with detectors like multi-angle light scattering (MALS) and fluorescence allows characterization of size, shape, and structure of macromolecules, nanoparticles, viruses, liposomes, and protein aggregates with high resolution.
Variation of Electrical Transport Parameters with Large Grain Fraction in Hig...Sanjay Ram
The electrical transport and its correlation with the microstructural properties in single phase microcrystalline silicon may be very different from the transport in microcrystalline silicon with a mixed phase of amorphous silicon. We have shown that the transport in single phase microcrystalline silicon may be predicted by the large grain fraction.
National Traceability of GPS Measurements in the Republic of Serbiavogrizovic
This document summarizes a study on establishing traceability of GPS measurements in Serbia. It describes Serbia's caesium atomic clock and time and frequency standard, which provides a reference for GPS measurements. The study established measurement equipment to compare the 1 pulse per second signal from the time standard to other reference points. Measurements showed time differences within nanoseconds. Allan variance analysis found the stability to be within microseconds for measurement intervals of 6 to 10 seconds. The study concluded by recommending full traceability be established from the working standards to the National Metrology Institute and BIPM, and that longer comparison measurements be conducted.
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1) Time reversal acoustics utilizes the time reversal invariance of the acoustic wave equation to focus waves in space and time.
2) A time reversal mirror records acoustic waves from a source and re-emits a time-reversed version of the recorded signal to focus it back to the original source location.
3) Experiments demonstrate that time reversal focusing works in complex media like random scatterers and waveguides, achieving focusing beyond
SEGMENTATION OF POLARIMETRIC SAR DATA WITH A MULTI-TEXTURE PRODUCT MODELgrssieee
1) The document describes a segmentation algorithm for polarimetric SAR (PolSAR) data that can model both scalar-texture and multi-texture scattering.
2) The algorithm uses log-cumulants and hypothesis testing to determine whether a scalar-texture or dual-texture model best fits the data within each segment.
3) The algorithm is tested on simulated multi-texture PolSAR data and is shown to accurately segment the classes and estimate their texture parameters. However, when applied to real data sets, the algorithm only finds the simpler scalar-texture case.
This document describes a numerical model that couples mechanical and heat and mass transfer processes during manufacturing of medium density fiberboard (MDF) using hot pressing. The model includes:
1) Heat and mass transfer equations accounting for air, water vapor, energy, and resin polymerization kinetics.
2) A mechanical model using an aging linear elastic constitutive law to model compression of the mat.
3) Coupling of the mechanical and heat/mass transfer models using a finite element method with implicit time stepping.
4) Numerical results from the model show good agreement with laboratory experiments and provide temperature, moisture content, and density profiles throughout the pressing process.
1) The document presents calculations to determine the per-unit-length parameters (capacitance C, inductance L, conductance G, and resistance R) of a coaxial cable transmission line.
2) It is shown that for a coaxial cable, the capacitance per unit length is given by C = 2πε0εr/ln(b/a) and the inductance per unit length is given by L = μ0μr/2πln(b/a), where a and b are the inner and outer radii.
3) Expressions are also derived for the conductance per unit length G = 2πσ/ln(b/a) and resistance per unit
The document discusses mechanistic-empirical (M-E) pavement design. It explains that M-E design uses a mechanistic approach to determine failure modes and an empirical approach to develop failure models. The two most common failure modes are tensile strain at the pavement surface causing fatigue cracking, and compressive strain at the subgrade leading to rutting. Seasonal changes in modulus are modeled for different pavement layers. Backcalculation of layer moduli uses deflection basin data from falling weight deflectometers.
This document provides technical properties of GEVACRIL acrylics in three categories: mechanical properties, optical properties, and thermal properties. It lists values for properties like specific weight, impact strength, tensile strength, elongation at break, light transmission, thermal conductivity, heat deflection temperature, and water absorption according to various industry standards. The properties are shown for cast and extruded acrylic sheet as well as polycarbonate for comparison. Notes explain the testing norms and standards used to obtain the property values.
The document discusses quantifying drag reducing additives (DRA) in jet fuel using rotary evaporation and gel permeation chromatography (GPC) detection. It proposes concentrating the DRA in a jet fuel sample using rotary evaporation, then analyzing it using GPC with an evaporative light scattering detector. Simplifications to the method include using a single GPC column, heptane mobile phase, and refractive index detection. Tests show the method can detect DRA at concentrations as low as 50 parts per billion in jet fuel.
Trends in Future CommunicationsInternational Workshop - Renato RabeloCPqD
This document summarizes research on electro-optic tunable sparse gratings in lithium niobate waveguides for applications in dense wavelength division multiplexing (DWDM) communication systems. It describes the fabrication of titanium diffused lithium niobate waveguides with silicon dioxide strain gratings to achieve mode conversion between the transverse electric and transverse magnetic modes. Test results show over 96% polarization conversion efficiency across the C-band with a free spectral range of 9.131 GHz. The device operates by applying a voltage to integrated electrodes to tune the polarization response across a wide wavelength range.
The document discusses using core data from carbonate rock samples to model NMR well log responses. It contains core data like T1 and T2 distributions from NMR experiments on different carbonate rock types. This data is used to simulate raw NMR well logs by matching acquisition parameters and modeling fluid properties. Fluid substitution and inversion modeling are also used to evaluate fluid identification and the effect of acquisition settings on interpretation. The goal is to calibrate well log NMR data using the detailed core measurements and better understand NMR responses in carbonate reservoirs.
This document describes the design and experimental validation of a nozzle intended to generate a laminar flow at low Reynolds numbers for experimental studies of upper airway flow. The nozzle was parameterized with a contraction ratio, length, and diameters to produce uniform mean flow and low turbulence at the exit. Hot film anemometry measurements of the exit flow validated uniform mean profiles and turbulence intensities less than 2%, consistent with a laminar boundary layer. The nozzle was shown to generate the desired laminar flow conditions for upstream applications modeling simplified replicas of the upper airways.
This document summarizes membrane separation technology used to purify anserine-carnosine extracted from chicken meat. It describes the background of membrane separation processes, materials used to prepare a chicken extract, various membrane types tested for separation, and results of experiments investigating the effect of operating pressure and flow rate on permeate flux and rejection rates of key components. It proposes a mathematical model to simulate experimental results and presents a process design for purifying anserine-carnosine from 5 tons of chicken carcass per day using membrane filtration.
Similar to Ink jet rheology and processing-Monash 2009 (20)
Werner Kuhn and Hans Kuhn were brilliant 1940s Swiss polymer scientists who developed theories on random coil statistics and entropy of polymer chains. Their work provided a foundation for understanding rubber elasticity. Andrew Keller, a 1950s-1970s Hungarian physical chemist, made important contributions to understanding polymer crystallization through his work on polyethylene single crystals. Pierre de Gennes, a prominent 20th century French physicist, applied his expertise in areas like superconductivity to develop the theory of polymer reptation. Piet Lemstra and Paul Smith were 1980s Dutch polymer scientists who successfully produced high modulus polyethylene through solution processing techniques.
Polyethylene polymer crystallisation results in beautiful crystalline microstructures. Polyethylene chains can form chain folded single crystals when crystallized from solution, or "shish kebab" fibrous crystals if shear is applied. When crystallized from the melt, polyethylene typically forms spherulite crystals made up of chain folded lamella that are 1-10 microns in diameter. The crystalline structures that form rival diamond in their beauty and molecular organization despite starting as flexible polymer chains.
Flow, Crystallisation and Continuous Processingmalcolmmackley
This presentation reviews the way flow can effect crystallisation. The presentation also reviews different ways continuous processing can be achieved. Continuous crystallisation is of relevance to a number of technologies including pharmaceutical manufacture.
This presentation gives a summary on the development of the Cambridge Trimaster which is an apparatus for studying the fast filament stretching, thinning and break up of low viscosity fluids. The apparatus is particularly relevant to ink jet fluids
This presentation was given in 2010 at a British Society of Rheology meeting on Biorheology held at Nottingham University.
The presentation describes the rheology of certain dysphagia formulations and then introduces "The Cambridge Throat". A mechanical device for following the way fluids are drawn into the throat by a model tongue and then how the fluid flows down the back of the throat.
This presentation was given at CEMEF (Mines ParisTech) Sophia Antipolis in 2005. The presentation is concerned with microstructure mechanisms that can explain certain shear thinning behaviour of certain complex fluids.
This document summarizes research on inventing plastic microcapillary films (MCFs) conducted by Malcolm Mackley and others at the University of Cambridge. The researchers developed a novel process to continuously extrude plastic MCFs with controlled voidage levels below 10% using a single-screw extruder, die design, and gas injection. They characterized the MCF structures and capillary sizes. Further mechanical drawing of the MCFs after extrusion was shown to orient the structure while limiting drawability due to necking in the capillaries. This research advanced engineering of plastic MCFs with tailored properties.
Professor David Moldenhauer is a Fellow of Robinson College and Professor of Process Innovation at the University of Cambridge who has pioneered new methods for shaping chocolate through extrusion and other non-traditional forming techniques by applying his scientific understanding of chocolate's properties and microstructure to invent innovative processing methods.
How to Interpret Trends in the Kalyan Rajdhani Mix Chart.pdfChart Kalyan
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5th LF Energy Power Grid Model Meet-up SlidesDanBrown980551
5th Power Grid Model Meet-up
It is with great pleasure that we extend to you an invitation to the 5th Power Grid Model Meet-up, scheduled for 6th June 2024. This event will adopt a hybrid format, allowing participants to join us either through an online Mircosoft Teams session or in person at TU/e located at Den Dolech 2, Eindhoven, Netherlands. The meet-up will be hosted by Eindhoven University of Technology (TU/e), a research university specializing in engineering science & technology.
Power Grid Model
The global energy transition is placing new and unprecedented demands on Distribution System Operators (DSOs). Alongside upgrades to grid capacity, processes such as digitization, capacity optimization, and congestion management are becoming vital for delivering reliable services.
Power Grid Model is an open source project from Linux Foundation Energy and provides a calculation engine that is increasingly essential for DSOs. It offers a standards-based foundation enabling real-time power systems analysis, simulations of electrical power grids, and sophisticated what-if analysis. In addition, it enables in-depth studies and analysis of the electrical power grid’s behavior and performance. This comprehensive model incorporates essential factors such as power generation capacity, electrical losses, voltage levels, power flows, and system stability.
Power Grid Model is currently being applied in a wide variety of use cases, including grid planning, expansion, reliability, and congestion studies. It can also help in analyzing the impact of renewable energy integration, assessing the effects of disturbances or faults, and developing strategies for grid control and optimization.
What to expect
For the upcoming meetup we are organizing, we have an exciting lineup of activities planned:
-Insightful presentations covering two practical applications of the Power Grid Model.
-An update on the latest advancements in Power Grid -Model technology during the first and second quarters of 2024.
-An interactive brainstorming session to discuss and propose new feature requests.
-An opportunity to connect with fellow Power Grid Model enthusiasts and users.
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Direct losses from downtime in 1 minute = $5-$10 thousand dollars. Reputation is priceless.
As part of the talk, we will consider the architectural strategies necessary for the development of highly loaded fintech solutions. We will focus on using queues and streaming to efficiently work and manage large amounts of data in real-time and to minimize latency.
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Must Know Postgres Extension for DBA and Developer during MigrationMydbops
Mydbops Opensource Database Meetup 16
Topic: Must-Know PostgreSQL Extensions for Developers and DBAs During Migration
Speaker: Deepak Mahto, Founder of DataCloudGaze Consulting
Date & Time: 8th June | 10 AM - 1 PM IST
Venue: Bangalore International Centre, Bangalore
Abstract: Discover how PostgreSQL extensions can be your secret weapon! This talk explores how key extensions enhance database capabilities and streamline the migration process for users moving from other relational databases like Oracle.
Key Takeaways:
* Learn about crucial extensions like oracle_fdw, pgtt, and pg_audit that ease migration complexities.
* Gain valuable strategies for implementing these extensions in PostgreSQL to achieve license freedom.
* Discover how these key extensions can empower both developers and DBAs during the migration process.
* Don't miss this chance to gain practical knowledge from an industry expert and stay updated on the latest open-source database trends.
Mydbops Managed Services specializes in taking the pain out of database management while optimizing performance. Since 2015, we have been providing top-notch support and assistance for the top three open-source databases: MySQL, MongoDB, and PostgreSQL.
Our team offers a wide range of services, including assistance, support, consulting, 24/7 operations, and expertise in all relevant technologies. We help organizations improve their database's performance, scalability, efficiency, and availability.
Contact us: info@mydbops.com
Visit: https://www.mydbops.com/
Follow us on LinkedIn: https://in.linkedin.com/company/mydbops
For more details and updates, please follow up the below links.
Meetup Page : https://www.meetup.com/mydbops-databa...
Twitter: https://twitter.com/mydbopsofficial
Blogs: https://www.mydbops.com/blog/
Facebook(Meta): https://www.facebook.com/mydbops/
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Mobile Security Framework - MobSF is a free and open source automated mobile application security testing environment designed to help security engineers, researchers, developers, and penetration testers to identify security vulnerabilities, malicious behaviours and privacy concerns in mobile applications using static and dynamic analysis. It supports all the popular mobile application binaries and source code formats built for Android and iOS devices. In addition to automated security assessment, it also offers an interactive testing environment to build and execute scenario based test/fuzz cases against the application.
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Using MobSF for static analysis of mobile applications.
Interactive dynamic security assessment of Android and iOS applications.
Solving Mobile app CTF challenges.
Reverse engineering and runtime analysis of Mobile malware.
How to shift left and integrate MobSF/mobsfscan SAST and DAST in your build pipeline.
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Monitoring and Managing Anomaly Detection on OpenShift
Overview
Dive into the world of anomaly detection on edge devices with our comprehensive hands-on tutorial. This SlideShare presentation will guide you through the entire process, from data collection and model training to edge deployment and real-time monitoring. Perfect for those looking to implement robust anomaly detection systems on resource-constrained IoT/edge devices.
Key Topics Covered
1. Introduction to Anomaly Detection
- Understand the fundamentals of anomaly detection and its importance in identifying unusual behavior or failures in systems.
2. Understanding Edge (IoT)
- Learn about edge computing and IoT, and how they enable real-time data processing and decision-making at the source.
3. What is ArgoCD?
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4. Deployment Using ArgoCD for Edge Devices
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5. Introduction to Apache Kafka and S3
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6. Viewing Kafka Messages in the Data Lake
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7. What is Prometheus?
- Get to know Prometheus, an open-source monitoring and alerting toolkit, and its application in monitoring edge devices.
8. Monitoring Application Metrics with Prometheus
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9. What is Camel K?
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10. Configuring Camel K Integrations for Data Pipelines
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11. What is a Jupyter Notebook?
- Overview of Jupyter Notebooks, an open-source web application for creating and sharing documents with live code, equations, visualizations, and narrative text.
12. Jupyter Notebooks with Code Examples
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Folding is a recent technique for building efficient recursive SNARKs. Several elegant folding protocols have been proposed, such as Nova, Supernova, Hypernova, Protostar, and others. However, all of them rely on an additively homomorphic commitment scheme based on discrete log, and are therefore not post-quantum secure. In this work we present LatticeFold, the first lattice-based folding protocol based on the Module SIS problem. This folding protocol naturally leads to an efficient recursive lattice-based SNARK and an efficient PCD scheme. LatticeFold supports folding low-degree relations, such as R1CS, as well as high-degree relations, such as CCS. The key challenge is to construct a secure folding protocol that works with the Ajtai commitment scheme. The difficulty, is ensuring that extracted witnesses are low norm through many rounds of folding. We present a novel technique using the sumcheck protocol to ensure that extracted witnesses are always low norm no matter how many rounds of folding are used. Our evaluation of the final proof system suggests that it is as performant as Hypernova, while providing post-quantum security.
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inQuba Webinar Mastering Customer Journey Management with Dr Graham HillLizaNolte
HERE IS YOUR WEBINAR CONTENT! 'Mastering Customer Journey Management with Dr. Graham Hill'. We hope you find the webinar recording both insightful and enjoyable.
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Key Takeaways:
Understanding the Customer Journey: Dr. Hill emphasized the importance of mapping and understanding the complete customer journey to identify touchpoints and opportunities for improvement.
Personalization Strategies: We discussed how to leverage data and insights to create personalized experiences that resonate with customers.
Technology Integration: Insights were shared on how inQuba’s advanced technology can streamline customer interactions and drive operational efficiency.
1. Seminar Monash University
11th March 2009
The rheology and processing of ink jet fluids.
by
Malcolm Mackley,
With acknowledgement to
Damien Vadillo, and Tri Tuladhar*
Department of Chemical Engineering, Cambridge
*Xaar plc
mrm5@cam.ac.uk
Department of Chemical Engineering
University of Cambridge
Cambridge, CB2 3RA, UK.
1
6. MPR as capillary rheometer
Diethyl phthalate (DEP) Supplier: Sigma Aldrich
BP = 294-296°C; ρ = 1118 kg/m3 ;
σ 20°C = 36 mN/m; η25°C = 10 mPa.s
Polystyrene: Supplier: BASF – Polystyrol VPT granule
M.W ~ 195000
100
ARES data MPR data
90
Apparent viscosity, η (mPa.s)
80
70 DEP
DEP + 1.0 wt% PS
60
DEP + 2.5 wt% Ps
50 DEP + 5.0 wt% PS
40
30
20
10
0
1 10 100 1000 10000 100000 1000000
Shear rate (/s)
6
7. Filament thinning
A.V.Bazilevsky, V.M. Entov and A.N.Rozhkov
3rd European Rheology Conference 1990 Ed D.R.Oliver
The “Russian Rheotester”
C A
B
E
15 cm
D
7
8. Liang and Mackley (1994)- Extensional Rheotester
Newtonian modelling
•
τzz τ zz = − p 0 + 2η γ zz = 0 (11)
•
τrr
Top plate
τ rr = − p 0 + 2η γ rr = −2σ / D (12)
•1•
D= εD (13)
Bottom plate
2
•
Extensional rheotester τ E = τ zz − τ rr = 3η ε = 2σ / D (14)
• 2σ
ε= (15)
3ηD
•
η E = τ E / ε = 3η (16)
σ
D(t ) = D0 − t (17)
3η
8
9. Liang and Mackley (1994)- Viscoelastic fluid
S1 fluid First approximation
1 (18)
D (t ) = D0 exp −
3λ t
R
Viscoelastic modelling
•
τ E = 3η ε d = 2σ / D (19)
• • •
τ E = g ε s = −2σ D/ D 2 (20)
• •
PIB solutions
εd = εs (21)
•
D/ D = − g / 3η (22)
g
D (t ) = D0 exp − t
3η (23)
9
10. MPR Filament stretch Rheometer
Vp
D
R(z,t)
Top Piston
Lf Rmid(t)
L0
Bottom Piston
Vp
(a) Test fluid positioned (b) Test fluid stretched uniaxially (c) Filament thinning and break up
between two pistons. at a uniform velocity. occurrence after pistons has stopped.
t<0 t≥0
10
11. MPR Filament stretching and thinning of DEP solution
DEP
DEP + 5.0 wt% PS
1.2 mm
Piston diameter = 1.2 mm
Initial stretch velocity = 200 mm/s
Initial sample height = 0.35 mm
Final sample height = 1.35 mm
(piston displaced by 0.5 mm each side)
11
12. The CambridgeTrimaster
A dream turning into a reality
Toothed belt Linear guide rail
timing pulley
Carrier
Timing belt
Replaceable top and
bottom plate
Stepper motor
attached to a pulley
12
Graphics courtesy of James Waldmeyer
13. Drive
belt
Piston
Linear
traverse
Motor
drive
a b
High speed camera
Fibre optic light
Cambridge Trimaster
13
14. Piston response
5000
4000 10 mm/s
100 mm/s
Top piston 500 mm/s
position (µm) 3000
2000
1000
c
0
0 100 200 300 400 500 600
Time (ms)
14
15. The ‘TriMaster’ Filament stretch and break up apparatus
piston
sample
belt
pulley
Initial gap ≈ 0.2 mm, Final gap ≈ 1.2 mm
15
Piston diameter ≈ 1.2 mm, Piston velocity ≈ 1 m/s
17. Filament thinning
a
5.3ms 5.8 6.3
6.8 7
7.2 7.7
(a) DEP,
b
(b) DEP + 0.2% PS110,
(c) DEP + 0.5% PS110,
(d) DEP + 1% PS110, 5.3ms 6 6.7
7 7.15
(e) DEP + 2.5% PS110. 7.3 7.6
c
Initial gap size: 0.6mm,
Stretching distance:0.8mm, 5.3ms 6.15 7
7.5 7.65
7.8 8
Stretching velocity:150mm/s
d
5.3ms 7 7.85
8.7 9.6
10.4 10.6
e
5.3ms 8.2 10.2 13.5
15.2
17
16.8 17
18. Mid filament diameter time evolution
1200
1000 0%
0.50%
800 1%
2.50%
D 5%
600
(µ m )
400
200
0
0 10 20 30 40
Time (ms )
18
19. 250
DEP-0%PS
DEP-0.5%PS
200
DEP-1%PS
Trouton ratio DEP-2.5%PS
150 DEP-5%PS
ηE
η0 100
50
0
0 2 4 6 8 10
D
Hencky strain, 2 ln 0
D
t
The transient extensional rheology of DEP solutions as a function of relaxation Hencky strain
for different PS concentrations.
Initial distance 0.6mm, final distance: 1.4mm.
The line represent are obtained from the exponential fitting of the evolution of the thinning of the diameter.
The geometrical factor “X” is fitted using the experimental data at low Hencky strain.
19
20. Breakup a
0ms 4 5.5
6.2 6.35 6.5
7
DEP, b
DEP + 0.5% PS110,
0ms 5 6.5
DEP + 1% PS110, 7.7 8.2 8.35
DEP + 2.5% PS110, 8.5
DEP + 5% PS110.
tial gap size: 0.6mm, c
etching distance: 1.6mm,
etching velocity: 150mm/s
0ms 6.7 8
9.35 9.85 10.15
10.35
d
0ms 7.5 10.65 14.15 17
17.15 17.35
e
0ms
38
10.7
39.15
22.35 31
39.35
20
21. Drop on demand ink jet process
(d) (e)
1
(a) (b) (c)
(f) (g)
2
3
(h) (i)
21
22. 1
Tail Filament a
Main drop
2 3
Ligament
Drop thread b
Newtonian “Optimum”
Viscoelastic
Viscoelastic
a b c
22
23. Measurement of Linear Viscoelasticity (LVE)
Piezo Axial Vibrator (PAV)
Developed by Prof Wolfgang Pechold
University of Ulm. Germany
Upper lid
Sample
Gap (steel ring foil)
Lower plate with
overflow ditch
Probe head
Piezoelectric (PZT)
elements stuck on a
square copper tube
Section of PAV
23
24. Mechanical equivalent model of PAV
2R The lower plate oscillates with constant force F (∝
m1
x1
excitation volt Uref) for a given frequency.
K* Sample d
With blank test: Dynamic compliance of the
m0
x0 lower plate is measured. ∆x ~ U eiδ
K1 K1
0
2 2
F 0 U ref
K01 F
With sample: Modulated compliance of the
x2 *
K02 m2 sample is measured ∆x U iδ
~ e
F U ref
Mechanical equivalent
model of the PAV. Complex squeeze stiffness K* of the material can
be calculated from the ratio of ∆x0 and ∆x*.
K02 K01 K* K1
m2 m0 m1
For linear viscoelasticity
2 d3 ρω 2 d 2
F G* = K * 1 +
+ ....
x2 x0 x1 3π R 4 10G *
G '2 +G"2
Mechanical representation G * (ω ) = G ' (ω ) + iG" (ω ) η* =
24 ω
with springs.
25. High frequency linear viscoelastic data of DEP-10% PS210 at 25°C
Parallel plate rheometer
1000 10000
η*
Complex viscosity, η*, (mPa.s)
Elastic (G') and Viscous (G")
1000
100
modulus, (Pa)
100
10
10 G"
1
G'
1 0.1
0.1 1 10 100 1000 10000
Frequency (Hz)
25
26. High frequency linear viscoelastic data of DEP-10% PS210 at 25°C
Parallel plate rheometer PAV data
1000 10000
η*
Complex viscosity, η*, (mPa.s)
Elastic (G') and Viscous (G")
1000
Open: ARES
100 Close: PAV
modulus, (Pa)
100
10
10 G"
1
G'
1 0.1
0.1 1 10 100 1000 10000
Frequency (Hz)
26
27. Effect of Polymer on the Linear Viscoelastic response of ‘model’
fluid containing different polymer concentration
Polystyrene MW = 210k in Diethyl phthalate solvent
1000 1000
0.1%
100 100 0.2%
Loss Modulus
G’’ 0% Elastic Modulus 0.4% C%
10 G’ 10 1%
Pa 0.1% 0%
0.2% Pa
1 1
0.4%
1%
0.1 0.1
1 10 100 1000 10000 100 1000 10000
Frequency (Hz) Frequency (Hz)
2.00E-02 1
0%
0.1% 0%
Complex 1.75E-02 0.2% Modulus ratio 0.1%
viscosity 0.4%
1%
G’/ G* 0.2%
0.4%
C%
η∗ 1.50E-02 0.1
Pa.s 1%
1.25E-02
1.00E-02 0.01
1 10 100 1000 10000 100 1000 10000
Frequency (Hz) Frequency (Hz)
27
27
28. 1% PS70
Eff: 1.08
Photo, courtesy of Dr Steve Routh
28
29. The effect of polymer addition
Polystyrene MW = 210k in Diethyl phthalate solvent
PAV Trimaster
1000
Elastic Modulus C%
G’ 100
Pa
10 1%
0.4%
1 0.2%
0.1%
0.1
100 1000 10000
Frequency (Hz)
No Polymer With Polymer
Development of the elasticity
as function of polymer Development of a long ligament
molecular weight for same
complex viscosity
29
30. Link between inkjet rheology and printability for printing inks
Work carried out in conjunction with IFM
G'/G* at 5 kHz frequency and 25°C
30%
Satellite Single drop Filaments / beads
No release
Dimensionless elastic modulus, G'/G*, (-)
25%
20%
Modulus
Ratio
G’/G* 15%
10%
5%
0%
DEP PS20- LB016- PS70- JSB1-B- PS110- JSB1-A- PS210- LB016- PS488-
5.0% 47 2.7% jetting 2.0wt% Non 1.7% 48 1.0%
30 jetting 30
31. The “Ulm” Torsion Resonator
The non linear viscoelastic behaviour (NLVE)
The piezoelectric sensor oscillates at its
two resonance frequencies, 26kHz and
77kHz respectively.
With blank test: Determination of the
apparatus constant K for each frequency
Piezoelectric
sensor With sample: Measure of the resonance
frequency shift Df and the damping shift
Sample
DD at each resonance frequency.
K ∆D 2
− ( ∆f )
2
Fluid vessel G =
'
ρ sample 2
with
Temperature K
control vessel G '' = ∆D.∆f
ρ sample
31
31
33. Conclusions
Piezo Axial Vibrator (PAV)
Can quantify LVE response of low viscosity viscoelastic fluids
Cambridge Trimaster
Can follow filament break up process of low viscosity fluids
Acknowledgments
EPSRC and industrial partners in
Next Generation Ink Jet Consortium
33