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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.
31

Time, energy & form

McInnis, Martha Jane January 1982 (has links)
Thesis (M. Arch.)--Massachusetts Institute of Technology, Dept. of Architecture, 1982. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ROTCH. / Includes bibliographical references. / Physical manifestations of time occur in natural forms of all sizes. Architectural form serves as shelter while providing a built envelope of human life, simultaneously influencing and influenced by energetic activities which occur within the containment. Change is either progressive or cyclic, apparently linear or circular. Similarly built form is either discontinuous or continuous, angular or curved. All physical presences, energetic configurations, are fleeting. Physical forms are shaped by time and so reflect the movement of the energy flows through time and space. Specific parts of time-space signify future forms while others revel in the past. / by Martha Jane McInnis. / M.Arch.
32

High-Capacity Freestanding Flexible Si Nanoparticles-Carbon Nanotubes Composite Paper Anodes for Li-Ion Batteries

Unknown Date (has links)
The growing environmental concern over carbon dioxide emission has driven the demand for next-generation green vehicles like electric vehicles (EVs) and hybrid electric vehicles (HEVs). This in turn calls for higher capacity and higher energy rechargeable batteries for supporting long-distance driving of EVs. In this research, freestanding flexible Si nanoparticles-carbon nanotubes (SiNPs-CNTs) composite paper anodes for lithium-ion batteries (LIBs) have been prepared by a simple, inexpensive, and scalable approach of ultrasonication and pressure filtration. No conductive additive, binder or metal current collector is used. The composite using multi-walled CNTs (MWNTs) shows electrochemical properties superior to those using single-walled CNTs (SWNTs) or vertically aligned carbon nanotubes (VACNTs). The SiNPs-MWNTs composite (Si-MW) sample achieves first cycle specific discharge and charge capacities of 2298 and 1492 mAh/g, respectively. The first cycle irreversibility is compensated for by stabilized lithium metal powder (SLMP) prelithiation, leading to reduction of initial capacity loss from 806 to 28 mAh/g and increase of initial coulombic efficiency from 65% to 98%. The relationship between different SLMP loadings and cell performance has been established to understand the prelithiation mechanism of SLMP, optimize the construction of Si-based cells, and enable the exploration of novel cathode materials. The positive effect of FEC as electrolyte additive (10%) on the cyclability is verified. Through control of Si/CNT weight ratio, the optimal combination between the high capacity of SiNPs and the high electrical conductivity and structural stabilization ability of MWNTs is found in the case of the Si-MW 3:2 composite, resulting in improved cycling stability and high rate capability. The reversible capacity can be recovered to 1866 mAh/g when the current rate returns to 100 mA/g during cycling at current rate from 100 to 1000 mA/g. After 100 cycles, the electrode retains a reversible capacity of 1170, 850, and 750 mAh/g at the current rate of 100, 280, and 500 mA/g, respectively. FEC-based electrolytes using FEC as the co-solvent (50 wt%) are compared with the one using FEC as the additive. It is found that the EC-free FEC-based electrolyte achieves higher specific capacity and better capacity retention in terms of long-term cycling. After 500 cycles, the capacity retention of the cell using DEC-FEC (1:1) is increased by 88% and 60% compared to the cells using EC-DEC-FEC (45:45:10) and EC-FEC (1:1), respectively. Through SEM-EDX and XPS analyses, a possible reaction route of formation of fluorinated semicarbonates and polyolefins from FEC is proposed. The inferior cell performance related to the EC-containing electrolytes is likely attributed to the formation of excessive polyolefins which do not favor Li ion migration. The strategy of capacity-control cycling is employed to seek extended cycle life. Stable 326 charge-discharge cycles at designated capacity of 506 mAh/g are attained for the Si-MW 1:1 cell. A self-healing phenomenon is observed by studying the specific capacities and charge/discharge end voltage, and proposed as the possible mechanism behind the improved cycling stability. Prolonged cycling of over 500 cycles under capacity control (500 mAh/g) and the interesting pattern of variation in the discharge/charge end voltage are successfully reproduced with different electrode/electrolyte and current conditions. EIS and SEM-EDX analyses suggest that by setting the capacity/voltage limits for charge-discharge cycling, the growth of SEI can be limited. We believe the 3D network of MWNTs forms a continuous conductive pathway within the composite structure, which ensures sufficient electrical conductivity, holds the Si particles together, and alleviates the volume expansion of Si. Moreover, the freestanding feature of our electrode eliminates the non-active mass, giving rise to specific energy enhanced by 27% compared to current graphite-based cells by theoretical calculation. / A Dissertation submitted to the The Program in Materials Science and Engineering in partial fulfillment of the Doctor of Philosophy. / Summer Semester 2017. / June 23, 2017. / carbon nanotubes, freestanding electrodes, high capcity, lithium ion batteries, silicon nanoparticles / Includes bibliographical references. / Jim P. Zheng, Professor Co-Directing Dissertation; Richard Liang, Professor Co-Directing Dissertation; Susan Latturner, University Representative; Albert E. Stiegman, Committee Member; Mei Zhang, Committee Member; Kenneth Hanson, Committee Member.
33

Sunsphere

Farkas, Andrew Everett, January 2004 (has links) (PDF)
Thesis (M.A.)--University of Tennessee, Knoxville, 2004. / Title from title page screen (viewed May 17, 2004). Thesis advisor: Michael Knight. Document formatted into pages (v, 155 p.). Vita.
34

An experimental investigation of the characteristic energy losses of 3-10 keV lithium particles in thin films

Majure, James Coyt 12 1900 (has links)
No description available.
35

Measurements of electrical double layer interactions in a nonpolar liquid /

Briscoe, Wuge H. Unknown Date (has links)
Thesis (PhD)--University of South Australia, 2001.
36

Acuity of force appreciation in the osteoarthritic knee joint this thesis is submitted to the Auckland University of Technology in partial fulfilment of the requirements for the degree of Master of Health Science (MHSc), School of Physiotherapy, 2007 /

Brereton, Helen. January 2007 (has links)
Thesis (MHSc--Health Science) -- AUT University, 2007. / Primary supervisor : Professor Peter McNair. Includes bibliographical references. Also held in print (xi, 147 leaves : col. ill. ; 30 cm.) in North Shore Campus Theses Collection (T 617.582 BRE)
37

Helical force flow: a new engineering mechanics model for biological materials

Thomas, Jeffery Scott, January 2009 (has links) (PDF)
Thesis (Ph. D.)--Missouri University of Science and Technology, 2009. / Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed May 4, 2009) Includes bibliographical references (p. 103-113).
38

Empowering students' scientific reasoning about energy through experimentation and data analyses

Abdelkareem, Hasan. January 2008 (has links)
Thesis (Ph. D.)--Michigan State University. Dept. of Curriculum, Teaching, and Educational Policy, 2008. / Title from PDF t.p. (viewed on July 7, 2009) Includes bibliographical references (p. 105-109). Also issued in print.
39

The controversy over living force Leibniz to DÁlembert /

Iltis, Carolyn, January 1967 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1967. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.
40

A study of the energy expenditure and mechanical efficiency of young girls and adult women

Thompson, Ethel Marion, January 1940 (has links)
Thesis (Ph. D.)--Columbia University, 1940. / Vita. Bibliography: p. 44-45.

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