China

  2009 NOV 24 - (VerticalNews.com) -- According to a study from Guangzhou, People's Republic of China, "An ensemble Monte Carlo simulation is presented to investigate the avalanche multiplication process in thin InP avalanche photodiodes (APDs). Analytical band structures are applied to the description of the conduction and valence band, and impact ionization is treated as an additional scattering mechanism with the Keldysh formula. ...read more

  2009 NOV 24 - (VerticalNews.com) -- According to recent research from Adana, Turkey, "Till age affects the chemical, biological and physical properties of agricultural soils and influences several soil quality indicators. We examined the effects of different tillage systems on selected soil quality Indicators In the semi-arid Mediterranean Coastal Plain of Turkey."

  "Five tillage practices were evaluated: conventional tillage with stubble burning (CT1), conventional tillage with stubble (CT2), minimum tillage (MT), rotational tillage (RT) and no-tillage (NT). The tillage treatments were used for winter wheat (Triticum aestivum), summer corn (Zea mays) and crop rotation of corn and winter wheat. Bulk density,. aggregate stability, plant available water, wilting point, field capacity water, organic carbon content and penetration resistance of the soil were evaluated. Conservation tillage systems' (MT, RT and NT) increased organic carbon content, aggregate stability and plant available water. Comparisons between samples collected in 2004 and 2006 showed that MT increased organic carbon by 7% at a soil depth of 0-10 cm whereas RT increased it by 10-20% at a depth of 0-20 cm. Aggregate stability was improved by 8-21% in the CT2, MT, RT and NT plots, but it decreased by 6% in the, CT1 plot at 20-30 cm depth. Available water increased from 11-71% in the MT, RT and NT treatments. The lowest bulk densities were found at the 0-10 cm depth in the MT (1.42 Mg m(-3)), 10-20 cm depth in the CT1 (1.44 Mg m(-3)) and 20-30 cm depth in the NT (1.45 Mg m(-3)) treatments, respectively. Penetration resistance in tilled soils (CT1, CT2 and MT) was lower compared with those in RT or NT treatments from the surface up to 15 cm, but differences among tillage systems' at 15-40 cm depth were not significant," wrote Z.B. Barut and colleagues, Cukurova University ...read more

  2009 NOV 24 - (VerticalNews.com) -- "The current work proposes a model describing the dynamics of coated microbubbles, which simplifies the traditional three-layer model to a two-layer one by introducing a visco-elastic interface with variable surface tension coefficients to connect the gas zone and the liquid zone. In the modified model, the traditional two interfaces boundary conditions are combined into one to simplify the description of the bubble," scientists writing in the journal Chinese Science Bulletin report ...read more