نتایج جستجو برای: soil pore system

تعداد نتایج: 2424367  

اوحدی, وحیدرضا , گودرزی, امیررضا ,

Considering the importance of micro-structural characteristics of clayey soils on their behavior, the main objective of this research is to investigate the effect of pore fluid properties variations on clayey soils and their physical and micro-structural changes. For experimental purposes, soil-electrolyte solutions with the ratio of 1:50 prepared. A series of physical experiments, as well as, ...

2014
Yuying Wang Chunsheng Hu Hua Ming Oene Oenema Douglas A. Schaefer Wenxu Dong Yuming Zhang Xiaoxin Li

The production and consumption of the greenhouse gases (GHGs) methane (CH4), carbon dioxide (CO2) and nitrous oxide (N2O) in soil profile are poorly understood. This work sought to quantify the GHG production and consumption at seven depths (0-30, 30-60, 60-90, 90-150, 150-200, 200-250 and 250-300 cm) in a long-term field experiment with a winter wheat-summer maize rotation system, and four N a...

Earthquake and its catastrophic failures has been one of the disturbance worry of Civil Engineers. In geotechnical science, liquefaction is one of the most important phenomenons induced by earthquake. A change in pore water pressure follows a change in effective stress, and in a critical state in which pore water pressure equals the total stress in soil particles, soil strength is suddenly lost...

Journal: :Chemosphere 2008
Rahel C Brändli Thomas Hartnik Thomas Henriksen Gerard Cornelissen

Organic pollutants (e.g. polyaromatic hydrocarbons (PAH)) strongly sorb to carbonaceous sorbents such as black carbon and activated carbon (BC and AC, respectively). For a creosote-contaminated soil (Sigma15PAH 5500 mg kg(dry weight(dw))(-1)) and an urban soil with moderate PAH content (Sigma15PAH 38 mg kg(dw)(-1)), total organic carbon-water distribution coefficients (K(TOC)) were up to a fact...

2014
Luiz F. Pires André B. Pereira

Soil porosity (ϕ) is of a great deal for environmental studies due to the fact that water infiltrates and suffers redistribution in the soil pore space. Many physical and biochemical processes related to environmental quality occur in the soil porous system. Representative determinations of ϕ are necessary due to the importance of this physical property in several fields of natural sciences. In...

Failure of the quay walls due to earthquakes results in severe economic loss. Because of hazards threatening such inexpensive nodes of national and international transportation networks, seismic design of quay walls is still an evolving topic in marine structural engineering. This study investigates the sensitivity of the gravity-type quay wall stability respect to uncertain soil and seismic pr...

2005
K.-J. S. Kung

1981; Gish and Jury, 1983; Edwards et al., 1993). Both physical and biological processes have temporal and Structural pores associated with macropore-type preferential flow spatial patterns of formation and destruction cycles pathways can accelerate chemical transport in unsaturated soils, thereby potentially causing groundwater contamination. To predict chemical (Gupta et al., 2002). Tillage p...

2010
Vladimir A. Samarkin Michael T. Madigan Marshall W. Bowles Karen L. Casciotti John C. Priscu Christopher P. McKay Samantha B. Joye

Nitrous oxide is a potent atmospheric greenhouse gas1 that contributes to ozone destruction2. Biological processes such as nitrification and denitrification are thought to drive nitrous oxide production in soils, which comprise the largest source of nitrous oxide to the atmosphere1. Here we present measurements of the concentration and isotopic composition of nitrous oxide in soil pore spaces i...

Journal: :Journal of contaminant hydrology 2004
S Hoeg H F Schöler J Warnatz

This paper presents results of a numerical investigation of soil vapor extraction (SVE) systems at the laboratory scale. The SVE technique is used to remove volatile chlorinated hydrocarbons (VCHC) from the water-unsaturated soil zone. The developed numerical model solves equations of flow, transport and interfacial mass transfer regarding an isothermal n-component and three-phase system. The m...

2011
Feike A. Dijkstra Jack A. Morgan Joseph C. von Fischer Ronald F. Follett

[1] Semiarid rangelands are a significant global sink for methane (CH4), but this sink strength may be altered by climate change. Methane uptake is sensitive to soil moisture showing a hump‐shaped relationship with a distinct optimum soil moisture level. Both CO2 and temperature affect soil moisture, but the direction of CH4 uptake response may depend on if the system is below or above the soil...

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