Cobalt ferrite nano particles have been of interest to researchers due to their diverse potential applications. In this paper, however, cobalt ferrite nano particles were prepared using the sol-gel ...process. An interest in understanding the role of the crosslinker and the chelating agent included in the sol-gel process is shown, and of the heat treatment on the structure and particle size of powder samples prepared. Several samples of cobalt ferrite powder were obtained by varying the quantity and the quality of the initial parameters of the process in addition to the annealing temperature. X-ray diffraction and scanning electron microscopy were used to identify the structure and morphology of samples respectively showing how the initial parameters affect them. The structure, the particle size and its distribution were found to be crucially influenced by the crosslinker and the chelating agent. PUBLICATION ABSTRACT
In the study of impact attenuation devices, rings/tubes have received a large amount of research due to their adaptability, i.e. they are low in cost and are readily available for selection in the ...design process. They also exhibit desirable force-deflection responses which is important in the design of energy absorbing devices. The function of such a device is to bring a moving mass to a controlled stop and ideally cause the occupant ride down deceleration to be within acceptable limits so as to avoid injuries or to protect delicate structures.
Optimized menus for a bioregenerative life support system have been developed based on measures of crop productivity, food item acceptability, menu diversity, and nutritional requirements of crew. ...Crop-specific biomass requirements were calculated from menu recipe demands while accounting for food processing and preparation losses. Under the assumption of staggered planting, the optimized menu demanded a total crop production area of 453 m2 for six crew. Cost of the bioregenerative food system is estimated at 439 kg per menu cycle or 7.3 kg ESM crew-1 day-1, including agricultural waste processing costs. On average, about 60% (263.6 kg ESM) of the food system cost is tied up in equipment, 26% (114.2 kg ESM) in labor, and 14% (61.5 kg ESM) in power and cooling. This number is high compared to the STS and ISS (nonregenerative) systems but reductions in ESM may be achieved through intensive crop productivity improvements, reductions in equipment masses associated with crop production, and planning of production, processing, and preparation to minimize the requirement for crew labor.
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