expansive soils can be found in many parts of the world particularly in arid and semi-arid regions. these soilspose a significant hazard to civil engineering structures due to its high swelling and shrinkage potential. this paperpresents the results of an experimental program developed to investigate the effect of cyclic drying and wetting on theswelling potential of expansive soils with variou...

abstract soil quality is an essential concept for maximum agriculture production without environmental destruction. studying soil physical quality indicators, that express soil structural stability and soil air-water balance in root zone, is one of the most important aspects of soil quality. so determination of optimal range for pore volume distribution is important and this research carried ou...

expansive soils are considered a worldwide problem as they cause extensive damage tocivil engineering structures. an important characteristic of expansive soils is theirsusceptibility to volume change due to the phenomenon of wetting and drying. this paperpresets the effect of pore water quality on the swelling and shrinkage behavior of anexpansive soil during wetting and drying cycles. thirty ...

solute transport processes are affected by soil pore water velocity distribution. pore size distribution, which can be used to infer pore water velocity distribution, can be estimated from a soil water retention curve (n). in this study, a solute breakthrough curve was simulated using soil hydraulic parameters in four different soils. to evaluate the proposed model, predictions were compared to...

constant rate of strain (crs) consolidation is a rapid test method used for determination of compressibility of clayey soils. in a crs test, the appropriate strain rate is selected based on pore water pressure ratio, i.e. the ratio of pore pressure to total stress. in the present study, to investigate the effect of strain rate on variation of relative pore water pressure, four different clay sa...

soilless media have different physical properties. change in air space of mix substrate can cause change in fertigation management and plant growth and yield. physical properties (water holding capacity, effective air-filled pore space, effective pore space) of 50 mixed substrates were measured to evaluate the effect of air-filled pore space on growth of tomato transplant and it's water us...

This paper compares the membrane processes available for water treatment. Membranes have the advantage of currently decreasing capital cost, a relatively small footprint compared to conventional treatment, generally a reduction in chemicals usage and comparably low maintenance requirements. Three membrane processes applicable to water treatment, micro- (MF), ultra- (UF), and nanofiltration (NF)...

biochar and activated carbon, as carbon-rich porous materials, have wide environmental applications. in the present research, rice husk (rh) was used for preparation of biochar at 400, 600, and 800 °c under simple pyrolysis, physically-activated carbon with water steam, chemically-activated carbon with potassium hydroxide (koh), and physiochemically-activated carbon with koh and steam. physical...