A. Ravve

Bio: A. Ravve is an academic researcher. The author has contributed to research in topics: Reversible addition−fragmentation chain-transfer polymerization & Step-growth polymerization. The author has an hindex of 1, co-authored 1 publications receiving 2019 citations.

Principles of polymer chemistry

Abstract: Physical Properties and Physical Chemistry of Polymers.- Free-Radical Chain-Growth Polymerization.- Ionic Chain-Growth Polymerization.- Ring-Opening Polymerizations.- Common Chain-Growth Polymers.- Step-Growth Polymerization and Step-Growth Polymers.- Naturally Occurring Polymers.- Reactivity and Chemical Modifications of Polymers.- Polymeric Materials for Special Applications.

Membrane Technology and Applications

Abstract: Overview of membrane science and technology membrane transport theory membrane and modules concentration polarization reverse osmosis ultrafiltration microfiltration gas separation pervaporation ion exchange membrane processes - electrodialysis carrier facilitated transport medical applications of membranes other membranes processed.

Hansen Solubility Parameters: A User's Handbook

Abstract: Solubility Parameters - An Introduction C.M. Hansen Hildebrand Parameters and Basic Polymer Solution Thermodynamics Hansen Solubility Parameters Methods and Problems in the Determination of Partial Solubility Parameters Calculation of the Dispersion Solubility Parameter deltad Calculation of the Polar Solubility Parameter deltap Calculation of the Hydrogen Bonding Solubility Parameter deltah Supplementary Calculations And Procedures Hansen Solubility Parameters for Water Theory - The Prigogine Corresponding States Theory, the c12 Interaction Parameter, and the Hansen Solubility Parameters C.M. Hansen Hansen Solubility Parameters (HSP) Resemblance Between Predictions of Hansen Solubility Parameters and Corresponding States Theories The c12Parameter and Hansen Solubility Parameters Comparison of Calculated and Experimental c12 Parameters General Discussion Postscript Statistical Thermodynamic Calculations of the Hydrogen Bonding, Dipolar, and Dispersion Solubility Parameters C. Panayiotou Theory Applications Discussion and Conclusions Appendix I: The Acid Dimerization Appendix II: An Alternative Form of the Polar Term Appendix III: A Group-Contribution Method for the Prediction of delta and deltaD Hansen Solubility Parameters (HSP) in Thermodynamic Models for Polymer Solutions G.M. Kontogeorgis Group Contribution Methods for Estimating Properties of Polymers Activity Coefficients Models Using the HSP Conclusions and Future Challenges Appendix I: An Expression of the FH Model for Multicomponent Mixture Methods of Characterization - Polymers C.M. Hansen Calculation of Polymer HSP Solubility - Examples Swelling - Examples Melting Point Determinations - Effect of Temperature Environmental Stress Cracking Intrinsic Viscosity Measurements Other Measurement Techniques Methods of Characterization - Surfaces C.M. Hansen Hansen Solubility Parameter Correlations with Surface Tension (Surface Free Energy) Method to Evaluate the Cohesion Energy Parameters for Surfaces A Critical View of the Critical Surface Tensions A Critical View of the Wetting Tension Additional Hansen Solubility Parameter Surface Characterizations and Comparisons Self-Stratifying Coatings Maximizing Physical Adhesion Methods of Characterization for Pigments, Fillers, and Fibers C.M. Hansen Methods to Characterize Pigment, Filler, and Fiber Surfaces Discussion - Pigments, Fillers, and Fibers Hansen Solubility Parameter Correlation of Zeta Potential for Blanc Fixe Carbon Fiber Surface Characterization Controlled Adsorption (Self-Assembly) Applications - Coatings and Other Filled Polymer Systems C.M. Hansen Solvents Techniques for Data Treatment Solvents and Surface Phenomena in Coatings (Self-Assembly) Polymer Compatibility Hansen Solubility Parameter Principles Applied to Understanding Other Filled Polymer Systems Hansen Solubility Parameters of Asphalt, Bitumen and Crude Oils P. Redelius Models of Bitumen Asphaltenes Molecular Weight Polarity Solubility Parameters of Bitumen Testing of Bitumen Solubility Hildebrand Solubility Parameters Hansen Solubility Parameters (HSP) The Solubility Sphere Computer Program for Calculation and Plotting of the Hansen 3D Pseudosphere Components of Bitumen Bitumen and Polymers Crude Oil Turbidimetric Titrations BISOM Test Determination of Hansen Solubility Parameter Values for Carbon Dioxide L.L. Williams Methodology One-Component Hildebrand Parameter as a Function of Temperature and Pressure Three-Component (Hansen) Solubility Parameters - Pure CO2 Temperature and Pressure Effects on HSPs: deltad Temperature and Pressure Effects on HSPs: deltap Temperature and Pressure Effects on HSPs: deltah Addendum Appendix I: Ideal Solubility of Gases in Liquids and Published CO2 Solubility Data Use of Hansen Solubility Parameters to Identify Cleaning Applications for "Designer" Solvents J. Durkee A Variety of Solvents Pathology of Soils HSP of Multiple-Component Soils Method for Calculating HSP of Composites (Soils or Solvents) More Realistic View About Evaluating HSP of Composite Soils Method for Choice of Suitable Solvents Reference Soils for Comparison Identification of Designer Solvents An Open Question - Answered Limiting RA Value For Expected Good Cleaning Performance Application of HSP Methodology to Cleaning Operations Analysis of Capability of Designer Solvents Applications - Chemical Resistance C.M. Hansen Chemical Resistance - Acceptable-or-Not Data Effects of Solvent Molecular Size Chemical Resistance - Examples Special Effects with Water Applications - Barrier Polymers C.M. Hansen Concentration-Dependent Diffusion Solubility Parameter Correlations Based on Permeation Phenomena Solubility Parameter Correlation of Polymer Swelling Solubility Parameter Correlation of Permeation Coefficients for Gases General Considerations Applications - Environmental Stress Cracking in Polymers C.M. Hansen ESC Interpreted Using HSP ESC With Nonabsorbing Stress Cracking Initiators Hansen Solubility Parameters - Biological Materials C.M. Hansen and T. Svenstrup Poulsen Hydrophobic Bonding and Hydrophilic Bonding (Self-Association) DNA Cholesterol Lard Human Skin Proteins - Blood Serum and Zein Chlorophyll and Lignin Wood Chemicals and Polymers Urea Water Surface Mobility Chiral Rotation, Hydrogen Bonding, and Nanoengineering Absorption and Diffusion in Polymers C.M. Hansen Steady State Permeation The Diffusion Equation Surface Resistance Side Effects Film Formation by Solvent Evaporation Anomalous Diffusion (Case II, Super Case II) Applications - Safety and Environment C.M. Hansen Substitution Alternative Systems Solvent Formulation And Personal Protection For Least Risk The Danish Mal System - The Fan Selection of Chemical Protective Clothing Uptake of Contents by a Plastic Container Skin Penetration Transport Phenomena The Future Hansen Solubility Parameter Data and Data Quality Group Contribution Methods Polymers as Points - Solvents as Spheres Characterizing Surfaces Materials and Processes Suggested for Further Attention Theoretical Problems Awaiting Future Resolution Appendices Hansen Solubility Parameters for Selected Solvents with the major contribution of Hanno Priebe Hansen Solubility Parameters for Selected Correlations Solubility Data for the Original 33 Polymers and 88 Solvents Index * Each Chapter contains an Abstract, an Introduction, and a Conclusion. Many chapters may also include Acknowledgements, Additional Discussions or General Comments/Considerations, and chapter-specific Key Words, Abbreviations, and Symbols

Funnels, pathways, and the energy landscape of protein folding: A synthesis

Abstract: The understanding, and even the description of protein folding is impeded by the complexity of the process. Much of this complexity can be described and understood by taking a statistical approach to the energetics of protein conformation, that is, to the energy landscape. The statistical energy landscape approach explains when and why unique behaviors, such as specific folding pathways, occur in some proteins and more generally explains the distinction between folding processes common to all sequences and those peculiar to individual sequences. This approach also gives new, quantitative insights into the interpretation of experiments and simulations of protein folding thermodynamics and kinetics. Specifically, the picture provides simple explanations for folding as a two-state first-order phase transition, for the origin of metastable collapsed unfolded states and for the curved Arrhenius plots observed in both laboratory experiments and discrete lattice simulations. The relation of these quantitative ideas to folding pathways, to uniexponential vs. multiexponential behavior in protein folding experiments and to the effect of mutations on folding is also discussed. The success of energy landscape ideas in protein structure prediction is also described. The use of the energy landscape approach for analyzing data is illustrated with a quantitative analysis of some recent simulations, and a qualitative analysis of experiments on the folding of three proteins. The work unifies several previously proposed ideas concerning the mechanism protein folding and delimits the regions of validity of these ideas under different thermodynamic conditions. © 1995 Wiley-Liss, Inc.

Stereospecific Olefin Polymerization with Chiral Metallocene Catalysts

Abstract: Current studies on novel, metallocenebased catalysts for the polymerization of α-olefins have far-reaching implications for the development of new materials as well as for the understanding of basic reaction mechanisms responsible for the growth of a polymer chain at a catalyst center and the control of its stereoregularity. In contrast to heterogeneous Ziegler–Natta catalysts, polymerization by a homogeneous, metallocene-based catalyst occurs principally at a single type of metal center with a defined coordination environment. This makes it possible to correlate metallocene structures with polymer properties such as molecular weight, stereochemical microstructure, crystallization behavior, and mechanical properties. Homogeneous catalyst systems now afford efficient control of regio- and stereoregularities, molecular weights and molecular weight distributions, and comonomer incorporation. By providing a means for the homo- and copolymerization of cyclic olefins, the cyclopolymerization of dienes, and access even to functionalized polyolefins, these catalysts greatly expand the range and versatility of technically feasible types of polyolefin materials. For corrigendum see DOI:10.1002/anie.199513681