The study of free-living nitrogen-fixing organisms in bulk soil is hampered by the great diversity of soil microbial communities and the difficulty of relating nitrogen fixation activities to individual members of the diazotroph populations. We developed a molecular method that allows analysis of nifH mRNA expression in soil in parallel with determinations of nitrogen-fixing activity and bacter...

To analyze the influence of liquid-nitrogen cooling on damage and failure high-temperature granite, granite samples were heated to 150~600 °C for natural treatment. Brazilian splitting tests carried out as returned room temperature, basic tensile energy evolution parameters obtained. Acoustic emission signal during loading recorded. The experimental results showed that heating process caused sa...

A new type of controlled release fertilizers coated with polyurea was prepared. The granulated urea was firstly changed into a liquid urea by heating as the coating liquid. By spraying uniformly the urea was coated with the polyurea synthesized by the reaction of isocyanates with a liquid urea. The effects of different modifiers on N release characteristics of polyurea-coated urea (PCU) were st...

Title of Document: FLOW AND ATOMIZATION CHARACTERISTICS OF CRYOGENIC FLUID FROM A COAXIAL ROCKET INJECTOR Vivek Gautam, Ph.D., 2007 Directed By: Professor, Ashwani K. Gupta, Department of Mechanical Engineering High thrust-to-weight ratio and consistent performance over a range of operating conditions make cryogenic rocket engines one of the best options for space propulsion. However, future sp...

The removal of biological nitrogen from a synthetic wastewater with different ammonium nitrogen concentrations (50 and 100 mgN-NH4/L) by a nitrification and denitrification process using a sequencing batch biofilm reactor (SBBR) with liquid-phase circulation was studied. The system with a total working volume of 4.6 L (3.7 L in the reactor and 0.9 L in the reservoir) treated 2.1 L of synthetic ...

This experiment attempted to detect the sound wave produced by bubbles in boiling water and liquid nitrogen as an application for LUX, large underground xenon, which is expected to detect weakly interacting massive particles, WIMPs. Currently, there are still several steps needed to be done in order to detect the bubble waveform. Before proceeding any further, it is necessary to change the curr...

The synthesis feasibility of silicon-tin nanocrystals by discharges in liquid nitrogen is studied using a Si-10 at % Sn sintered electrode. Time-resolved optical emission spectroscopy shows that silicon and tin melt almost simultaneously. The presence of both vapours does not lead to the synthesis of alloyed nanocrystals but to the synthesis of separate nanocrystals of silicon and tin with aver...