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Clemson University

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Articles 31 - 35 of 35

Full-Text Articles in Physics

Comparison Of Thermoelectric Properties Of Arc-Melted And Hot-Pressed Half-Heuslers, Brad Edwards Aug 2007

Comparison Of Thermoelectric Properties Of Arc-Melted And Hot-Pressed Half-Heuslers, Brad Edwards

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Relatively low thermal conductivity and great electrical properties in combination with wide tuning parameters through doping make half-Heuslers high potential thermoelectric materials. In this study we plan to investigate the effects of hot-pressing and arc-melting on the thermoelectric properties of ZrNiSn0.975Sb0.025, and Hf0.75Zr0.25NiSn0.975Sb0.025 samples. Also, the effects of electron and phonon scattering due to the insertion of small 50 nm particles within the sample were investigated in ZrNiSn0.975Sb0.025 +4% Al2O3 and Hf0.75Zr0.25NiSn0.975Sb0.025 +4% Al2O …


The Thermoelectric Properties Investigation Of Ir3Ge7 Typed Representatives, Huqin Zhang Aug 2007

The Thermoelectric Properties Investigation Of Ir3Ge7 Typed Representatives, Huqin Zhang

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Energy conversion is employed to power generation utilizing the Seebeck effect or cooling utilizing the Peltier effect. Herein, we study several Ir3Ge7 typed semiconductor materials for potential thermoelectric energy conversion. Mo3Sb7, crystallizing in Ir3Ge7 type, can be rendered semiconducting by a partial Sb-Te substitution without noticeable structure changes, resulting in Mo3Sb5Te2 with 55 valence electrons per formula unit. Meanwhile, large cubic voids in the Mo3Sb5Te2 crystal structure provide the possibility of filling the voids with small cations to decrease the …


Comparison Between Steady State And Laser Flash Techniques, Justine Andrews Aug 2007

Comparison Between Steady State And Laser Flash Techniques, Justine Andrews

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Thermoelectrics is a promising avenue of energy conservation. A material is deemed a good thermoelectric material when it portrays certain material characteristics. These characteristics include a high thermopower and electrical conductivity and a low thermal conductivity. This thesis focuses on the methods of measuring a material's thermal conductivity.
The steady state method is a measurement technique used in the low temperature thermal conductivity measurements. This technique assures that the system and sample are at equilibrium before a measurement point is taken. As a result the measurements are both precise and accurate.
The laser flash technique measures a sample's thermal conductivity …


Carbon Nanomaterials In Biological Systems, Sijie Lin Aug 2007

Carbon Nanomaterials In Biological Systems, Sijie Lin

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This thesis intends to present, from the biophysical viewpoint, my study on understanding carbon nanomaterials in biological and environmental systems. Carbon nanotubes and fullerenes represent a major family of carbon nanoparticles which possess distinct electrical, optical and mechanical properties. However, the major hurdle for making carbon nanomaterials bioavailable lies in their tendency toward bundling, driven by hydrophobic interaction, van der Waals force, and pi-stacking. To overcome this problem, we used non-covalent binding of zwitterionic lysophopholipids (LPL) onto the external surfaces of single-walled carbon nanotubes (SWNTs). This method affords superior SWNT solubility in aqueous solution. The stability of SWNT-LPL complex …


Assembly And Modification Of A Hyperthermal And Low Energy Ion Beamline For Detecting Electron-Hole Pair Production In Schottky Diodes, Matthew Ray Dec 2006

Assembly And Modification Of A Hyperthermal And Low Energy Ion Beamline For Detecting Electron-Hole Pair Production In Schottky Diodes, Matthew Ray

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A hyperthermal and low energy ion beamline to measure electron-hole pair production due to ion bombardment of Schottky diodes has been modified and assembled.
A brief overview of the instrument is given and the reason for operating the ion beamline in the hyperthermal and low energy regime is discussed. The capabilities of the ion beamline are unique and provide the means to measure quantities that offer insight into various energy exchange mechanisms that occur at surfaces. Combined with the ability to accept Schottky diode samples, the beamline is capable of measuring both charge transfer and electron-hole pair production caused by …