this study analyzed the relationship between the vertical distribution of root biomass and soil organic carbon (soc)content in the arid shrub lands of semnan province in iran. three sites were selected based on differences in canopy coverof artemisia sieberi (5%, 10% and 15%). average density of shrubs, root biomass and soc were determined at differentdepths (0-20, 20-40, 40-60, 60-80 cm) in 20...

in the processing of carbon/carbon composites using polymer resin as the matrix precursor, it is inevitable that a porous structure was formed after carbonization. as a result, densification by liquid phase impregnation followed by recarbonization is required to obtain a densified composite. consequently, the char formability of resin is an important factor in reducing the number of densificati...

the unique properties of air-cooled bainitic steels have been described. a series of mn containing air-cooled bainitic steels invented by authors is presented in this paper: including low carbon granular bainitic steels, low carbon grain-boundary allotriomorphic ferrite/granular bainite duplex steels, medium and medium high carbon bainite/martensite duplex steel, and low carbon carbide free bai...

objective: soil organic carbon has been the most important soil quality measurement factors and has intense relation with soil physical, chemical and biological characteristics. organic matter and its components are important factors of soil aggregates constitution and stability and play significant role in its structure. so, this research has been done for achieving this purpose. methods: this...

Thick wafer-silicon is the dominant solar cell technology. It is of great interest to develop ultra-thin solar cells that can reduce materials usage, but still achieve acceptable performance and high solar absorption. Accordingly, we developed a highly absorbing ultra-thin crystalline Si based solar cell architecture using periodically patterned front and rear dielectric nanocone arrays which p...

Recent developments in nanophotonics have provided a clear roadmap for improving the efficiency of photonic devices through control over absorption and emission of devices. These advances could prove transformative for a wide variety of devices, such as photovoltaics, photoelectrochemical devices, photodetectors, and light-emitting diodes. However, it is often challenging to physically create t...

Silicon has been driving the great success of semiconductor industry, and emerging forms of silicon have generated new opportunities in electronics, biotechnology, and energy applications. Here we demonstrate large-area free-standing ultrathin single-crystalline Si at the wafer scale as new Si materials with processability. We fabricated them by KOH etching of the Si wafer and show their unifor...

global warming and climate change have drawn special attention to soil and its potential for stable carbon sequestration. soils are the largest stores of carbon in terrestrial carbon cycle and contain about three times more carbon than vegetation cover and two times more than that of atmosphere. studying the effects of grazing on soil carbon storage is important because of the major role soil o...

.soil microorganisms are important agents in nutrient cycling and energy flow. they are extremely sensitive to environmental changes. soil microbial biomass has been proposed as an index of soil stress and disturbance. the objective of this study was to determine the effects of barley (hordeum vulgare l.) residue amounts, burning, nitrogen fertilizer levels and tillage management on organic car...