he presence of moisture in a transformer deteriorates transformer insulation by decreasing both the electrical and mechanical strength. In general, the mechanical life of the insulation is reduced by half for each doubling in water content [l]; the rate of thermal deterioration of the paper is proportional to its water content [2]. Electrical discharges can occur in a high voltage region due to...

This study was conducted to determine the significance of bromacil transport as a function of water and carbon content in soils and to explore the implications of neglecting sorption when making assessments of travel time of bromacil through the vadose zone. Equilibrium batch sorption tests were performed for loamy sand and sandy soil added with four different levels of powdered activated carbo...

The recovery of ethanol from aqueous solutions was studied by using supercritical carbon dioxide. At 333.2 K and 10.0 MPa, vapor /liquid equilibrium data of the mixture CO2 /ethanol /water were determined. No azeotrope was observed. Theoretical calculation of equilibrium stages was performed and compared with countercurrent column experiments. Separation of extract and solvent was optimized by ...

A process for the chemical modification of Chinese fir with alkyl ketene dimer (AKD) was studied. The hydrophobicity of the resulting products was evaluated by characterization of the equilibrium moisture content, water-surface contact angle, water absorption coefficient, and antiswelling efficiency. The results indicated that when 5% AKD solution was used, the modified wood generally showed go...

varieties of st. john’s wort (hypericum perforatum l.) native to iran possess the largest percentage of hypercin in their leaves and flowers. isotherm curves show the relationship between the relative humidity and moisture content of the plant at a constant temperature. it is essential to understand the isotherms curves for successful storage and drying of the plant. this study used adsorption ...

the clay crosslinked hydrogel nanocomposites were synthesized by graft copolymerization of acrylamide and itaconic acid in the presence of different amounts of laponite using ammonium persulfate and n,n,n',n'-tetramethylethylene diamine  )temed) as a free radical initiator and catalyst, respectively. the xrd patterns of nanocomposites showed that the clay layers are completely exfolia...

In slope engineering, soils are commonly at unsaturated state. The question of how to apply unsaturated soil mechanics theory to the slope stability analysis has become a hot spot in today’s geotechnical engineering research. Based on the experimental research of how shear strength of residual soil varies with water content, reasonable computation modules can be created. By using limit equilibr...

A soil-water characteristic (SWC) curve describes the amount of water retained in a soil (expressed as mass or volume water content, m or v) under equilibrium at a given matric potential. An SWC is an important hydraulic property, related to size and connectedness of pore spaces, hence strongly affected by soil texture and structure, and by other constituents, including organic matter. Modeling...

The objective of this study was to investigate the effects of hot water extraction process on the dimensional stability of oriented strand composites. Aspen wood strands were extracted using various severity factor levels. Phenol formaldehyde and polymethylene diphenyl diisocyanate resins were used for production of the oriented strandboard panels. Six panel groups were produced from the extrac...