Absorption of water

About: Absorption of water is a research topic. Over the lifetime, 12725 publications have been published within this topic receiving 181715 citations. The topic is also known as: Water absorption.

Physical Properties of Textile Fibres

Abstract: Introduction to fibre structure Testing and sampling Fibre fineness and transverse dimensions Fibre length Fibre density Thermal properties Equilibrium absorption of water Heats of sorption Rate of absorption of moisture The retention of liquid water Swelling Theories of moisture sorption Tensile properties The effects of variability Elastic recovery Rheology Directional effects Thermo-mechanical responses Fibre breakage and fatigue Theories of mechanical properties Dielectric properties Electrical resistance Static electricity Optical properties Fibre friction.

Absorption chillers and heat pumps

Abstract: Introduction Heat Pumps Heat-Driven Heat Pumps Description of Current Absorption Products Outlook for Absorption Technology Absorption Cycle Fundamentals Carnot Cycles Absorption Heat Pump, Type I Absorption Heat Transformer, Type II Absorption Heat Pump as Combination of Rankine Cycles Reversible Analysis with Variable Temperatures Irreversibilities in Absorption Cycle Processes Zero-Order Absorption Cycle Model Absorption Cycle Design Optimization Properties of Working Fluids Analytic Treatment of Thermodynamic Properties Graphical Perspective on Thermodynamic Properties of Absorption Working Fluids Thermodynamic Processes with Mixtures Mixing of Fluids and the Heat of Mixing Specific Heat of Mixtures Desorption Absorption Condensation and Evaporation Compression Pumping Throttling Ammonia Purification Heat Exchangers WATER/LITHIUM BROMIDE SYSTEMS Overview of Water/Lithium Bromide Technology Fundamentals and Operation Crystallization and Absorber Cooling Requirements Corrosion and Materials Compatibility Vacuum Requirements Octyl Alcohol Normal Maintenance and Expected Life Controls Single-Effect Water/Lithium Bromide Technology Single-Effect Water/Lithium Bromide Chiller Operating Conditions Single-Effect with Heat Transfer Models Single-Effect Water/Lithium Bromide Heat Transformer (Type II Heat Pump) Discussion of Available Single-Effect Systems Double-Effect Water/Lithium Bromide Technology Double-Effect Water/Lithium Bromide Cycles Solution Circuit Plumbing Options Operating Conditions of Double-Effect Machines Systems on the Market Advanced Water/Lithium Bromide Cycles Half-Effect Cycle Triple-Effect Cycle Resorption Cycle Additional Water/Lithium Bromide Technology AMMONIA/WATER SYSTEMS Single-Stage Ammonia/Water Systems General Considerations Performance Calculations Examples of Ammonia/Water Absorption Systems in Operations Two-Stage Ammonia/Water Systems Double-Effect Ammonia/Water Systems Double-Lift Ammonia/Water Systems Two-Stage Triple-Effect Ammonia/Water System Generator/Absorber Heat Exchange (GAX) Cycles Concept, Configurations and Design Considerations Branched GAX Systems GAX Cycle Hardware Diffusion Absorption Cycle Introduction Cycle Physics Choice of the Auxiliary Gas Total Pressure of the System Cycle Performance APPENDICES Properties of LiBr/H2O Properties of NH3/H2O Absorption Cycle Modeling Concentration Measurements by Titration Introduction to Engineering Equation Solver Overview of the ABSIM Software Package References Index

Comparison of water absorption in natural cellulosic fibres from wood and one-year crops in polypropylene composites and its influence on their mechanical properties

Abstract: Environmentally beneficial composites can be made by replacing glass fibres with various types of cellulose fibres. Fibres from pine or eucalyptus wood and also one-year crops such as coir, sisal, etc. are all good candidates. The poor resistance towards water absorption is one of the drawbacks of natural fibres/polypropylene composites. New natural fibres/polypropylene composites were made and the water absorption in them was studied by immersion of the composites in water at three different temperatures, 23, 50 and 70 °C. The process of absorption of water was found to follow the kinetics and mechanisms described by Fick's theory. In addition, the diffusivity coefficient was dependent on the temperature as estimated by means of Arrhenius law. A decrease in tensile properties of the composites was demonstrated, showing a great loss in mechanical properties of the water-saturated samples compared to the dry samples. The morphology change was monitored by scanning electron microscopy studies of the samples before and after exposure to water and the devastating effect of water on the fibre structure was shown.

Characterization of natural fiber surfaces and natural fiber composites

Abstract: Experiments have been performed to further the development of natural fiber reinforced composites as a replacement for glass fiber composites. Untreated and treated surfaces of natural fibers were characterized using FTIR, XPS, and ESEM. Changes in the peaks in the FTIR spectrum at 1730, 1625 and 1239 cm −1 indicated that the alkali treatment removes hemicellulose and lignin from natural fiber surfaces. ESEM indicated the presence of silane on treated hemp and kenaf. XPS shows that hemp has a lower O/C ratio than kenaf. Water absorption experiments were also conducted to determine saturation mass gain. Alkali treated fiber composites absorbed more water than silane treated or untreated composites. The natural fiber composites absorbed more water than the glass fiber composites. Hemp composites, in general, performed worse in flexural testing than kenaf composites.