Production and Characterization of High Repetition Rate Terahertz Radiation in Femtosecond-Laser-Induced Air Plasma

The purpose of this research was to produce and characterize high repetition rate terahertz radiation in ionized air plasma. An 800 nanometer, 50 femtosecond, 0.35 Watt, 40 KHz, pulsed Ti:Sapphire laser system was used as the source infrared beam. This beam was focused onto a second harmonic generation crystal to produce a collinear, perpendicularly polarized secondary beam at 400 nm. After realigning the polarization of the fundamental to the second harmonic and compensating for group velocity dispersion introduced by the optics, both beams were recombined and focused by a 3.75 cm focal length mirror to form an air plasma. An electrical bias of up to 27 kV/cm was applied across the plasma to enhance the terahertz and plasma signal. The air plasma intensity was measured using a 40 kHz ultrasonic transducer, while the terahertz radiation was measured by a silicon bolometer. Terahertz of reasonable power was detected and characterized using this method. Both the terahertz and the plasma were characterized concurrently throughout this experiment in an effort to determine the feasibility of using the ultrasonic transducer as an alignment aid. The characterization included the effects of polarization, bias, and delay on the plasma and terahertz signals. During the course of this research it was also discovered that silicon, often used as a filter to isolate the detector from the laser in terahertz research, was a significant source of terahertz as well. This experiment represents the first time THz was generated using the two color interaction modified by an external applied bias

Drill control studies with formulations of Polystream and Sevin for 1963

During 1963 , the Virginia Institute of Marine Science conducted a series of tests on oyster drill control with formulations of Polystream , a chlorinated hydrocarbon and Sevin , an insecticide . The utility of these two compounds had previously been investigated by the U. S. Fish and Wildlife Service in Long Is land Sound, in the laboratory and in field trials on commercial beds. Several of these earlier fie ld studies indicated that the treatment prescribed was effective in drill control. Consequently, application was made to the U. S. Department of Agriculture for an experimental permit. The permit was granted , laying the groundwork for further experimental field trials supervised by state or federal agencies

Treatment Of Shell Cultch With Polystream To Increase The Yield Of Seed Oysters, Crassostrea Virginica

A commercial scale study was conducted on the Eastern Shore of Virginia during 1964, 1965 and 1966 to evaluate treatment of shell cultch with Polystream. Three intertidal reefs of the same approximate size were shelled with similar amounts of untreated shells

Automatic Labeling of Special Diagnostic Mammography Views from Images and DICOM Headers.

Applying state-of-the-art machine learning techniques to medical images requires a thorough selection and normalization of input data. One of such steps in digital mammography screening for breast cancer is the labeling and removal of special diagnostic views, in which diagnostic tools or magnification are applied to assist in assessment of suspicious initial findings. As a common task in medical informatics is prediction of disease and its stage, these special diagnostic views, which are only enriched among the cohort of diseased cases, will bias machine learning disease predictions. In order to automate this process, here, we develop a machine learning pipeline that utilizes both DICOM headers and images to predict such views in an automatic manner, allowing for their removal and the generation of unbiased datasets. We achieve AUC of 99.72% in predicting special mammogram views when combining both types of models. Finally, we apply these models to clean up a dataset of about 772,000 images with expected sensitivity of 99.0%. The pipeline presented in this paper can be applied to other datasets to obtain high-quality image sets suitable to train algorithms for disease detection

Examining The Perceptions Of Brand Images Regarding Competing MBA Programs

In today’s economic environment, it is crucial to create a strong, consistent brand image within a graduate business program. This study examines the perceptions that students at Southeastern Louisiana University hold about its MBA program and the MBA programs of its main competitors. A focus group was conducted to indentify competitors and factors used to compare MBA programs. A questionnaire was designed and distributed and the results were analyzed using perceptual maps

Galactic Center Pulsars with the ngVLA

Pulsars in the Galactic Center (GC) are important probes of General Relativity, star formation, stellar dynamics, stellar evolution, and the interstellar medium. Despite years of searching, only a handful of pulsars in the central 0.5 deg are known. The high-frequency sensitivity of ngVLA will open a new window for discovery and characterization of pulsars in the GC. A pulsar in orbit around the GC black hole, Sgr A*, will provide an unprecedented probe of black hole physics and General Relativity.Comment: To be published in the ASP Monograph Series, "Science with a Next-Generation VLA", ed. E. J. Murphy (ASP, San Francisco, CA

Respiratory Control: Central and Peripheral Mechanisms

Understanding of the respiratory control system has been greatly improved by technological and methodological advances. This volume integrates results from many perspectives, brings together diverse approaches to the investigations, and represents important additions to the field of neural control of breathing. Topics include membrane properties of respiratory neurons, in vitro studies of respiratory control, chemical neuroanatomy, central integration of respiratory afferents, modulation of respiratory pattern by peripheral afferents, respiratory chemoreception, development of respiratory control, behavioral control of breathing, and human ventilatory control. Forty-seven experts in the field report research and discuss novel issues facing future investigations in this collection of papers from an international conference of nearly two hundred leading scientists held in October 1990. This research is of vital importance to respiratory physiologists and those in neurosciences and neurobiology who work with integrative sensory and motor systems and is pertinent to both basic and clinical investigations. Respiratory Control is destined to be widely cited because of the strength of the contributors and the dearth of similar works. The four editors are affiliated with the University of Kentucky: Dexter F. Speck is associate professor of physiology and biophysics, Michael S. Dekin is assistant professor of biological sciences, W. Robert Revelette is research scientist of physiology and biophysics, and Donald T. Frazier is professor and chairman of physiology and biophysics. Experts in the field report current research and discuss novel issues facing future investigations. —SciTech Book Newshttps://uknowledge.uky.edu/upk_biology/1002/thumbnail.jp

HEAT: Hydraulic and Electric Animation Team

Each New Years’ Day, the Cal Poly Rose Float presents a flower-covered float to the world at the Tournament of Roses parade. This floral display, paired with moving mechanical animations, shows off Cal Poly to the world. This project strove to keep Cal Poly on the cutting edge of technology both in parade floats, and in engineering, by creating a completely electric-powered animation system. To accomplish this, a group of students set out to make the fully electric animation system that can power both the hydraulic and electric mechanisms on the Float. This was accomplished through months of planning and development leading up to manufacturing, assembling, and testing the system. The students used deep cycle lead acid batteries to power an electric motor. This motor turns a hydraulic pump that pumps fluid throughout the animated mechanism actuators. Aside from being cutting edge, this new animation system is both quieter and a lower-profile on the float. This allows for the design of the float to be lower, more unique, and beautiful. It also creates less noise pollution during animation testing and makes communication easier during this time