Master of Science, The Ohio State University, 2005, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Science, The Ohio State University, 1968, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Science, University of Akron, 2019, Chemical Engineering

The next generation electronic devices are expected to be small in size and of magnified capacity. Denser packaging of the active components is important to miniaturize the electronic devices. Denser packaging is feasible only when heat generated by heat sources is quickly and effectively carried away to the heat sink. Next generation electronic devices with high performance microprocessors and integrated circuits along with diminished volume have led to major heat dissipation issue. Heat dissipation helps to control the temperature of the electronic devices at a desired level. Heat is dissipated to the heat sink from heat generator by the process of thermal conduction. Due to irregularities on the surfaces of the heat generator and heat sink, air is entrapped, and the air gap is formed in the path of thermal conduction. Air gap disturbs the thermal conduction as air is a really poor thermal conductor with a thermal conductivity of 0.026 W/mK at room temperature. Air acts as a thermal barrier preventing the effective heat transfer between the heat source and heat sink. Different kind of thermal interface materials are used to fill up the air gap between the heat generator and the heat sink to improve thermal conduction. Introduction of thermal interface material can significantly increase the performance of electronic device. In a typical power electronic package, a grease is used as thermal interface material. Thermal conductive paste with high thermal conductivity (much greater than air) fills up all the air gaps between the heat generator and the heat sink to improve the thermal conduction. Development of the thermal conductive paste with low thermal resistance, high thermal conductivity and low electric conductivity is challenging and the most important aspect in today's electronic industries. In the current study, we have tried to overcome this challenge by developing a thermally conductive grease with low thermal resistance, high thermal conductivity and low (open full item for complete abstract)

Committee: Jiahua Zhu PhD (Advisor); Rajeev Gupta PhD (Committee Member); Zhenmeng Peng PhD (Committee Member) Subjects: Chemical Engineering; Engineering; Polymers

Doctor of Philosophy, The Ohio State University, 1986, Graduate School

Committee: Not Provided (Other) Subjects: Physics

Doctor of Philosophy, The Ohio State University, 1973, Graduate School

Committee: Not Provided (Other) Subjects: Physics

Doctor of Philosophy, The Ohio State University, 1968, Graduate School

Committee: Not Provided (Other) Subjects: Engineering

Doctor of Philosophy, The Ohio State University, 1968, Graduate School

Committee: Not Provided (Other) Subjects: Engineering

Doctor of Philosophy, The Ohio State University, 1965, Graduate School

Committee: Not Provided (Other) Subjects: Physics

Master of Science (MS), Ohio University, 2008, Geological Sciences (Arts and Sciences)

The Western Allegheny Plateau Ecoregion (WAP) and Shade River Watershed in SE Ohio were investigated to determine the chemical composition of waters and sediments, and their relationship with geology, land-use and biological indices. Ninety-three sites were sampled within the WAP with twenty-two sites in the Shade River. Chemical concentration of the waters in the Shade River fell within the USEPA criteria for the protection of aquatic life except DO, iron, manganese and phosphate while the causes of impairment within the WAP included pH, DO, EC, alkalinity, phosphate, iron, manganese, nitrate and sulfate. The waters were Ca-HCO3 dominated with weathering being the main process controlling the water chemistry. Biological indicator such as Index of Biotic Integrity (fish) was sensitive to PO4, Na, K, Ca, Mg, Cl and DO while Invertebrate Community Index (macroinvertebrate) correlated with pH, acidity and DO. Periphyton Index of Biotic Integrity (algae) showed no relationship with water chemistry.

Committee: Dina L. Lopez L (Advisor); Keith Milam (Committee Member); Greg Nadon (Committee Member) Subjects: Geology