What causes natural durability in Eucalyptus bosistoana timber?

This study investigated the natural durability of 8 and 60 year old Eucalyptus bosistoana (coast grey box). The sample’s heartwood compounds were extracted with an optimised extraction process and then incorporated into agar. Trametes versicolor (white rot) and Gloeophyllum trabeum (brown rot) fungi were grown upon these agars and their growth rate was used to assess the fungicidal abilities of the extracts. The extraction method of cell wall compounds was optimised. An Accelerated Solvent Extraction system (ASE) was used with the following settings: • 2 cycles per sample • 70°C extraction temperature • 50% rinse • 5 minute static time Ethanol was found to extract the compounds of the highest fungicidal activity. Ethanol was found to extract similar amounts to water (~13% of dry weight for a 60 year old sample), however analysis of both water and ethanol extracts with a FTIR spectrometer, found that they were of different chemical composition. A difference in fungicidal activity of extracts was found between the 8 year old and 60 year old samples. There was a large difference in the percentage of extracts present between the samples as well as the type of compounds present, shown by FTIR

Исследование кинетики поверхностного растворения в водных дисперсиях некоторых материалов

Приведены результаты исследования кинетики поверхностного растворения в водных дисперсиях ряда материалов. Степень выщелачивания определялась по изменению рН растворов-центрифугатов и электропроводности. Время контакта материала с водой составляло от 6 до 1500 минут. У таких материалов, как магнетитовый концентрат, илы, ташлинский песок, равновесие практически устанавливается в течение 1,5-2 часов. При т:ж=1:4 поверхностное растворение бентонита в первый час значительно меньше, чем у остальных исследованных материалов (х=4-6), а затем резко возрастает до х=40 ом-1. При большем содержании воды диспергирование бентонита происходит быстрее и уже после часового контакта материала с водой; наблюдается значительный рост электропроводности (x=22 ом-1)

Experimental Tests of Discrete Strengthened Elements of Machine-Building Structures

Computer simulation and bench tests of components and full-scale structures of internal combustion engine are performed in order to evaluate discrete and continual strengthening technology. The contact pressure distributions, friction coefficients, wear, roughness and hardness of the contacting surfaces of the tested machine parts were determined. The numerical characteristics that determine the effectiveness of such combined strengthening method are established. Conceptual fundamentals of discrete continual strengthening have been developed. Positive effects in the “load – contact – friction – wear” chain were found due to the proposed strengthening method. The positive effect of the coordination of micro and macroscale processes and states of loaded parts, which are strengthened by the discrete and continuous method, is also established. It is confirmed that the entire set of tribo-mechanical characteristics is improved with such strengthening, in contrast to traditional methods, an application of which results in improvement in some characteristics at the cost of the others

Разработка архитектуры и программных средств витрин данных для предприятия нефтегазовой отрасли

Анализируются проблемы создания отраслевых информационно-аналитических систем, основанных на современных OLAP-технологиях. Рассмотрен вариант архитектуры хранилища данных для крупного нефтегазодобывающего предприятия на примере проектирования тематической витрины данных, включающего анализ специфической предметной области, проектирование многомерных структур данных, постановку аналитических задач и их решение