72,815 research outputs found

    Ancient and historical systems

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    The complex binder based on Portland cement andash-and-slag wastes from thermal power stations

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    Increase in the balance of boiler and furnace fuel of the energy sector of the Republic of Belarus the proportion of own energy resources (milling peat and wood chips) places priority on resolving the issues of utilization of ash-and-slag wastes and reducing the area of ash-and-slag disposal sites, which cause irreparable damage to the environment. A considerable amount of research has been devoted to the utilization of ash-and-slag wastes. There are more than 300 technologies of their recycling and use. Ash and slag wastes are used in the production of concrete, mortars, ceramics, heat and water insulating materials, road construction. The world experience shows the potential of 70-80% utilization of ash and slag, as, for example, in some European countries. However, the cost of the recycling of ash-and-slag wastes with the production and simultaneous neutralization of wastes can be higher than the cost of the production. One of the directions of the use of ash and slag wastes is the production on their basis of new types of complex binder that have increased strength and low prime cost. The replacement of a part of cement with active mineral additive allows to achieve significant saving of binder. The existing methods of the production of complex binders include the stages of joint or separate grinding of cement clinker and mineral additive with following mixing. Significant energy costs for grinding increase the cost of binder. In this regard, the development of the effective complex binder with the use of ash-and-slag wastes of the Belarussian state district power station in Orekhovsk using resource-saving technology is the actual research objective

    NASA guidelines on report literature

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    NASA seeks for inclusion in its Scientific and Technical Information System research reports, conference proceedings, meeting papers, monographs, and doctoral and post graduate theses which relate to the NASA mission and objectives. Topics of interest to NASA are presented

    Design, fabrication and characterization of monolithic embedded parylene microchannels in silicon substrate

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    This paper presents a novel channel fabrication technology of bulk-micromachined monolithic embedded polymer channels in silicon substrate. The fabrication process favorably obviates the need for sacrifical materials in surface-micromachined channels and wafer-bonding in conventional bulk-micromachined channels. Single-layer-deposited parylene C (poly-para-xylylene C) is selected as a structural material in the microfabricated channels/columns to conduct life science research. High pressure capacity can be obtained in these channels by the assistance of silicon substrate support to meet the needs of high-pressure loading conditions in microfluidic applications. The fabrication technology is completely compatible with further lithographic CMOS/MEMS processes, which enables the fabricated embedded structures to be totally integrated with on-chip micro/nano-sensors/actuators/structures for miniaturized lab-on-a-chip systems. An exemplary process was described to show the feasibility of combining bulk micromachining and surface micromachining techniques in process integration. Embedded channels in versatile cross-section profile designs have been fabricated and characterized to demonstrate their capabilities for various applications. A quasi-hemi-circular-shaped embedded parylene channel has been fabricated and verified to withstand inner pressure loadings higher than 1000 psi without failure for micro-high performance liquid chromatography (µHPLC) analysis. Fabrication of a high-aspect-ratio (internal channel height/internal channel width, greater than 20) quasi-rectangular-shaped embedded parylene channel has also been presented and characterized. Its implementation in a single-mask spiral parylene column longer than 1.1 m in a 3.3 mm × 3.3 mm square size on a chip has been demonstrated for prospective micro-gas chromatography (µGC) and high-density, high-efficiency separations. This proposed monolithic embedded channel technology can be extensively implemented to fabricate microchannels/columns in high-pressure microfludics and high-performance/high-throughput chip-based micro total analysis systems (µTAS)

    Resident research associateships. Postdoctoral and senior research awards

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    Opportunities for research at Marshall Space Flight Center's Materials and Processes Laboratory, Space Sciences Laboratory, and Systems Dynamics Laboratory are described. Information is provided for applicants desiring designation as a research associate and a list of laboratory directors and research advisors is provided

    Fiscal year 1973 scientific and technical reports, articles, papers, and presentations

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    Formal NASA technical reports, papers published in technical journals, and presentations by MSFC personnel in FY73 are presented. Papers of MSFC contractors are also included

    Стійка технологія переробки відходів електричного та електронного обладнання

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    Об’єкт досліджень: технологічні основи «переробки відходів електричного та електронного обладнання». Предмет досліджень: механізм піролізу, отримання рідкого палива, подрібнення друкованих плат після піролізу, вібраційний млин та його сили, які впливають на подрібнення. Вихідні дані для проведення роботи: характеристики друкованих плат та їх переробка у світі. Наукова новизна: відокремлення металевої фракції від наповнювачів, за рахунок ковкості металевої фракції при подрібнені та подальшому розділення при грохочені. Практична цінність: поліпшення екологічної складової за рахунок втілення нових технологій в сектор управління відходів та рециклінгу вже добутих мінералів. Дипломна робота написана англійською мовою та надалі буде захищена в ТУ "Фрайберзька гірнича академія"

    Center for low-gravity fluid mechanics and transport phenomena

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    Research projects in several areas are discussed. Mass transport in vapor phase systems, droplet collisions and coalescence in microgravity, and rapid solidification of undercooled melts are discussed
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