"This thesis documents the experimental proof of concept study for an ultrasonic method of wake vortex detection. A new acoustic technique is utilized to measure the circulation produced in the wake of lift-generating aircraft. Ultrasonic signals are transmitted in a path around the wake vortex, and are used to determine the average in-line velocity component along the acoustic path. It is shown herein that this velocity component is directly proportional to the net circulation value within the acoustic path. This is the first study to take this methodology and implement it in a realistic airport setting. This project included constructing a prototype and conducting field tests to prove the validity of this technology in a realistic environment setting. During field tests an acoustic path enclosed the vorticity shed behind one wing of a Piper PA-28 aircraft. Fourteen initial test flights were conducted in calm atmospheric conditions, and results show circulation values measured are comparable in magnitude and direction to expected circulations generated by the Piper PA-28 aircraft. Additional testing in various atmospheric conditions revealed the scope of practice for such a measurement technology. This study demonstrates the validity of the acoustic method in detecting aircraft wake vortices. Future investigations and applications utilizing this technique are discussed within."

The mechanical properties of thin-film Li-ion battery electrodes are controlled by the micro structure of the constituent materials. In this work, a non-contact and non-destructive measurement of the mechanical properties of electrode films is performed by measurement of zero group velocity (ZGV) resonances. The ZGV Lamb wave modes of a solid bi-layer consisting of a thin metallic layer and a thin compliant coating layer are shown to be dependent on the Young's moduli, thicknesses, densities and Poisson ratios of the layers. Theoretical models are used to quantify the sensitivity of the ZGV resonances to changes in mechanical properties. Experimental ZGV resonances are excited using a pulsed infrared laser and detected using a laser interferometer. Commercial-grade battery films with different coating materials, densities and thicknesses are measured. Young's moduli of the battery electrode layers are estimated using the combination of a theoretical model and experimental results. The effect of the calendering process on the battery materials is also investigated. Results suggest that the Young's modulus of the electrode coating increases drastically after the battery films are calendered. This technique can be used to quantitatively study the mechanical properties of Li-ion battery electrodes to improve overall battery performance.

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Объектом исследования являются 3 образца нанокерамики на основе Al2O3, и 4 образца кварцевых стекол: КИ, КВ, КУ, КС-4В. Цель данной работы – исследование акустических свойств, обусловленных особенностями микро- (нано)структуры двух категорий материалов микро- и оптоэлектроники – нанокерамики на основе Al2O3 и оптических кварцевых стекол. В процессе работы были: исследованы акустические свойства материалов микро- (нанокерамика на основе Al2O3) и оптоэлектроники (кварцевые стекла), исследованы оптические параметры кварцевых стекол и установлена корреляция между акустическими и оптическими параметрами. В результате исследования был создан оригинальный измерительный стенд и разработана методика измерения значений скоростей поперечных ультразвуковых волн, определены упругие характеристики нанокерамики на основе Al2O3 и кварцевых стекол, а также оптические параметры стекол. В данной работе удалось установить корреляцию между акустическими и оптическими параметрами. Используя измерения скоростей ультразвука и оптического поглощения, были определены фундаментальные характеристики образцов. Это способствует пониманию структурно-чувствительных свойств, а значит, в дальнейшем и влиять на них, создавая материалы с нужными параметрами для лучшей работы приборов микро- и оптоэлектроники. / Objects of research are 3 samples of nanoceramiсs based on Al2O3 and 4 samples of quartz glasses: KI, KU, KV, KS-4V. The aim of this work is the study of the acoustic properties due to the peculiarities of micro- (nano)structures of the two categories of micro- and optoelectronics materials: nanoceramics based on Al2O3 and optical quartz glass. The acoustic properties of materials micro- (nanoceramics based on Al2O3) and optoelectronics (quartz glass) were studied, the optical parameters of quartz glass were investigated, and a correlation between acoustic and optical parameters was found. The original test stand and the method of measuring the transverse ultrasonic waves velocities were created, the elastic characteristics of nanoceramics based on Al2O3 and optical quartz glass and the optical parameters of glass were determine. In this paper we determined a correlation between acoustic and optical parameters. Using measurements of the velocity of ultrasound and optical absorption fundamental characteristics of the samples were determined. This contributes to an understanding of structure-sensitive properties that will help create materials with the necessary parameters for the best performance of micro- and optoelectronics.