Physics Commons^™

Artificial Olfactory System For Multi-Component Analysis Of Gas Mixtures., Alexander Aleksandrovich Larin

Electronic Theses and Dissertations

Gas analysis is an important part of our world and gas sensing technology is becoming more essential for various aspects of our life. A novel approach for gas mixture analysis by using portable gas chromatography in combination with an array of highly integrated and selective metal oxide (MOX) sensors has been studied. We developed a system with small size (7 x 13 x 16 inches), low power consumption (~10 W) and absence of special carrier gases designed for portable field analysis (assuming apriori calibration). Low ppb and even sub-ppb level of detection for some VOCs was achieved during the analysis …

Numerical Investigation Of Drop Impingement On Dry And Wet Surfaces., Yisen Guo

Electronic Theses and Dissertations

In-flight icing due to supercooled large droplets (SLDs) imposes great danger on aviation safety. Because of the large size, SLDs have different characteristics than typical cloud droplets that most icing encounters involve. As a result, SLDs more likely hit the wing surface and move into areas not protected by de-icing devices to form ice, which can lead to loss of lift, increase in drag, altered controllability, and eventually stall and loss of control of the aircraft. The phenomenon of droplet splashing is considered as the most important aspect of the SLD icing accretion problem. Although previous studies have established splashing …

All-Optical Switching In Ferromagnetic Superlattices., Faren Hoveyda Marashi

Electronic Theses and Dissertations

The unexpected observation of ultrafast demagnetization (UDM) and subsequent time-resolved studies of laser-induced magnetization switching opened a new door to both fundamental physics and technological applications of magnetic materials. All-optical switching (AOS) can be initiated faster than the precession limit, hinting to its potential in increasing the writing speed and data storage density. However, notwithstanding considerable research interest, the mechanism of AOS in ferromagnetic materials remained unclear.

Ferromagnetic superlattices were deposited on glass substrates with e-beam evaporation and sputtering. Magnetization curves were measured in magneto-optical and vibrating sample magnetometer experiments. A femtosecond Ti:S laser was utilized in a writing setup …

Fabrication And Functionalization Of Carbon Nanocages For Use In Cfx Batteries., Nathan Smith

Electronic Theses and Dissertations

A relatively inexpensive method for obtaining high quality lithium-CF_x batteries is reported. Nickel acetate and citric acid are used to synthesize a precursor which is then annealed and subsequently etched to fabricate highly uniform 3 nm radius pristine CNCs. These CNCs are then functionalized with fluorine using an RF plasma system. The resulting fluorinated CNCs are then combined with a carbon binder and pressed onto a stainless steel mesh to form a CF_x cathode. This cathode is then tested in a coin cell primary battery with a lithium anode. Results indicate that a specific capacity of 660 mAh/g …

Synthesis And Fundamental Property Studies Of Energy Material Under High Pressure., Meysam Akhtar

Electronic Theses and Dissertations

Recently, high-pressure science and technology has flourished and rapidly advanced to impact a wide domain of materials and physical sciences. One of the most substantial technological developments is the integration of samples at ultrahigh pressure with a wide range of in-situ probing techniques. Applications of extreme pressure have significantly enriched our understanding of the electronic, phonon, and doping effects on the newly emerged two-dimensional (2D) materials. Under high pressure, materials’ atomic volume radically decreases, and electronic density rises, which will lead to extraordinary chemical reaction kinetic and mechanisms. The promising capability of high pressure combine with the significance of novel …