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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Effects of soluble soybean polysaccharide as filling agent on the properties of leathers

Tang, Zhenye, Zhong, Jide, Feng, Xianqing, Zhang, Yafei, Hu, Yadi, Liu, Hui, Liu, Jie, Ferah, Cem Emre, Tang, Keyong 28 June 2019 (has links)
Content: Soluble soybean polysaccharide (SSPS) is good in emulsification, and stable emulsion may be formed with the addition of SSPS in fatliquoring agents. In this paper, with wet blues as raw materials, after being retanned and neutralized, fatliquoring and filling up with SSPS were carried out at the same time, with different amounts of SSPS, i.e., 1%, 3%, 5%,7% in weight. The leather samples were dried at room temperature. The effects of SSPS amounts on the thickness, air permeability and water vapor permeability of the crust leather were studied. The tensile properties of the leathers filled by SSPS were analyzed. The results indicated that with increasing the amounts of SSPS, the thickness and the water vapor permeability of the leathers increase, while the air permeability decreases slightly. The maximum stress-strain capacity of leathers decreases with increasing the SSPS amount. At the SSPS amount of 3%, the leather is good in softness, as well as in physical and mechanical properties. Take-Away: 1.SSPS from soybean dregs is an acidic polysaccharide, which is rich in raw materials and low in cost. 2.Leathers filled with SSPS have good performance.
2

The application of systems engineering to a Space-based Solar Power Technology Demonstration Mission

Chemouni Bach, Julien 07 June 2012 (has links)
This thesis presents an end-to-end example of systems engineering through the development of a Space-based Solar Power Satellite (SSPS) technology demonstration mission. As part of a higher education effort by NASA to promote systems engineering in the undergraduate classroom, the purpose of this thesis is to provide an educational resource for faculty and students. NASA systems engineering processes are tailored and applied to the development of a conceptual mission in order to demonstrate the role of systems engineering in the definition of an aerospace mission. The motivation for choosing the SSPS concept is two fold. First, as a renewable energy concept, space-based solar power is a relevant topic in today's world. Second, previous SSPS studies have been largely focused on developing full-scale concepts and lack a formalized systems engineering approach. The development of an SSPS technology demonstration mission allows for an emphasis on determining mission, and overall concept, feasibility in terms of technical needs and risks. These are assessed through a formalized systems engineering approach that is defined as an early concept or feasibility study, typical of Pre-Phase A activities. An architecture is developed from a mission scope, involving the following trade studies: power beam type, power beam frequency, transmitter type, solar array, and satellite orbit. Then, a system hierarchy, interfaces, and requirements are constructed, and cost and risk analysis are performed. The results indicate that the SSPS concept is still technologically immature and further concept studies and analyses are required before it can be implemented even at the technology demonstration level. This effort should be largely focused on raising the technological maturity of some key systems, including structure, deployment mechanisms, power management and distribution, and thermal systems. These results, and the process of reaching them, thus demonstrate the importance and value of systems engineering in determining mission feasibility early on in the project lifecycle. / text

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