A Stable Optical Trap from a Single Optical Field Utilizing Birefringence

We report a stable double optical spring effect in an optical cavity pumped with a single optical field that arises as a result of birefringence. One end of the cavity is formed by a multilayer Al$_{0.92}$Ga$_{0.08}$As/GaAs stack supported by a microfabricated cantilever, with a natural mode frequency of $274$ Hz. The optical spring shifts the resonance to $21$ kHz, corresponding to a suppression of low frequency vibrations by a factor of more than $10^{4}$. The stable nature of the optical trap allows the cavity to be operated without any external feedback and with only a single optical field incident

Multi-objective optimization of the economic feasibility for mobile on-site oil and gas produced water treatment and reuse

2021 Summer.Includes bibliographical references.Development of unconventional oil and gas wells has resulted in large volumes of produced and flowback water that require careful handling to minimize environmental and human health risks due to high concentrations of salt and other contaminants. Common practice is to truck the wastewater from well sites to Environmental Protection Agency (EPA) Class II underground injection control (UIC) wells. The cost of transportation often accounts for much of the handling costs. As an alternative, on-site desalination followed by surface water discharge of the water product for downstream reuse has the potential to lower handling cost by reducing the volume of water requiring transport to UIC wells while additionally alleviating strain on water supplies in arid regions. In contrast to centralized FP water treatment, capacity factor for on-site desalination is highly dependent on management strategy and shale bed characteristics. Therefore, this work studies how accounting for capacity factor might determine the attributes of an optimal management strategy and the cost of produced water treatment. The volume of wastewater to be treated by desalination, the method for desalination unit deployment, desalination unit capacity, and desalination technology (membrane distillation, mechanical vapor compression, and reverse osmosis) are decision variables defining a management strategy. This work explores different produced and flowback water management strategies in Weld County, Colorado, to determine a set of Pareto optimal produced water management strategies from a techno-economic and environmental perspective optimizing economics and water reclamation. Results show that as the desired level of water reclamation increases there is an increase in the marginal cost of water reclamation. Ultimately, the optimal volume of wastewater to be reused was determined to be between 50% and 88% of the total produced costing between $5.82 and$9.79 per m3, respectively, in Weld County, CO where business as usual operation (injection) cost is $7.68 per m3. Generally, optimal management strategies, when accounting for capacity factors, utilized packaged desalination units of 100 m3/d capacity with deployment location reevaluated on a 1-6 month planning horizon

Senior Recital: Gabriella Paul, cello

This recital is presented in partial fulfillment of requirements for the degree Bachelor of Music in Music Education. Ms. Paul studies cello with Prof. Charae Krueger.https://digitalcommons.kennesaw.edu/musicprograms/2361/thumbnail.jp

Novel radiographic presentation of primary syphilis of the tonsil

A 61-year-old HIV+ male presented to an infectious disease clinic with a complaint of sore throat. A painless ulcerated mass was discovered on the right tonsil resulting in further evaluation with a CT scan of the neck. Imaging confirmed the presence of a mass centered on the palatine tonsil and associated lymphadenopathy. A presumptive diagnosis of HPV-related squamous cell carcinoma was made due to patient risk factors. However, multiple biopsies found no evidence of carcinoma, but instead revealed the presence of spirochetes that stained positive fo

Mapping the optical absorption of a substrate-transferred crystalline AlGaAs coating at 1.5 µm

The sensitivity of 2nd and 3rd generations of interferometric gravitational wave detectors will be limited by thermal noise of the test-mass mirrors and highly reflective coatings. Recently developed crystalline coatings show a promising thermal noise reduction compared to presently used amorphous coatings. However, stringent requirements apply to the optical properties of the coatings as well. We have mapped the optical absorption of a crystalline AlGaAs coating which is optimized for high reflectivity for a wavelength of 1064nm. The absorption was measured at 1550nm where the coating stack transmits approximately 70% of the laser light. The measured absorption was lower than (30.2 +/- 11.1)ppm which is equivalent to (3.6 +/- 1.3)ppm for a coating stack that is highly reflective at 1530nm. While this is a very promising low absorption result for alternative low--loss coating materials, further work will be necessary to reach the requirements of <1ppm for future gravitational wave detectors. Jessica Steinlechner, Iain W Martin, Angus Bell, Garrett Cole, Jim Hough, Steven Penn, Sheila Rowan, Sebastian Steinlechne