Integrating Pulsed High Power Light Emitting Diodes for Schlieren Imaging

This honors thesis describes the development of a light source for schlieren imaging that is based on pulsed high-brightness light emitting diodes. Schlieren imaging is an optical technique that enables the visualization of density gradients in flows. The work involves the customization and fabrication of the circuit for the purpose of imaging of supersonic wind tunnel flows and includes the design of the circuit enclosure and the integration of the lamp into the schlieren system. The final product is demonstrated in the High-Speed Wind Tunnel at the J.J. Pickle Research Campus at UT Austin. Several prototypes were tried, and the final design offers a safe, easy to use pulsed light source, which can be integrated into many schlieren systems.Mechanical Engineerin

Book Review: Brownfields: A Comprehensive Guide to Redeveloping Contaminated Property

Brownfields: A Comprehensive Guide to Redeveloping Contaminated Property by Todd S. Davis and Kevin D. Margolis, with a preface by Vice President Al Gore is a guide for assisting individuals with understanding Brownfields. Based on her years of experience as a practitioner in the field, the reviewer believed that this book is an excellent tool for lawyers who wish to become acquainted with the complexities of brownfields redevelopment. The reviewer states that the book does an excellent job at not limiting its analysis to any one point of view. The reviewer noted that the book begins by clearly defining the term, and then proceed with analyzing the subject of brownfields redevelopment from a multiple of perspectives, including developers , regulators, environmental groups, health professionals, bankers, and property owners. No matter which one of these interested parties is the client, this book contains valuable information so that a lawyer may successfully assist any client involved in a brownfields redevelopment project

Effects of Impoundments on the Community Assemblage and Gene Flow of Stream Crayfishes

Dams and their impoundments block movement of stream organism and change stream physiochemical properties, which subsequently changes biological assemblages and creates barriers to gene flow. While changes in species assemblages and gene flow have been assessed for numerous impoundments and stream organisms, no study has assessed the effects of large impoundments on crayfish assemblages and population genetic diversity and connectivity. I examined the physiochemical, biological, and genetic effects of impoundments on crayfishes. Between May 2015 and August 2017, I sampled multiple sites up- and downstream of three impounded streams, and along the lengths of two unimpounded streams, in the Bear Creek and Cahaba River drainages in Alabama, USA. First, I assessed the most effective sampling methods for collecting crayfishes in high gradient southern Appalachian streams. A combination of kick seining and electroshocking were most effective at collecting crayfishes, with higher species richness and decreased sampling biases when using both methods. Once effective methods were established, I assessed the effects of impoundments and their subsequent changes to crayfish assemblages and their habitats. Impoundments altered crayfish assemblages up- and downstream of impoundments. Crayfish abundances and species diversity were lower in impounded than unimpounded streams. Assemblages up- and downstream of impoundments were similar, but in unimpounded streams, gradual shifts in dominant species occurred from up- to downstream. Assemblage differences between impounded and unimpounded streams were associated with more stable temperature and flow regimes, decreases in crayfish refuge habitats (i.e., aquatic vegetation, interstitial space), and increased abundances of predatory fishes in impounded streams. Nonetheless, with distance downstream of impoundments, crayfish assemblages began to recover and resemble unimpounded stream assemblages. Impoundments also impacted gene flow and genetic structure of crayfishes. Impounded streams’ crayfish populations were genetically isolated, and unidirectional downstream gene flow, or no gene flow, was detected between up- and downstream populations. The degree of impact of impoundments on gene flow was species-specific, with intrinsic biological and life history characteristics, such as dispersal ability and physiological tolerance, determining the degree of impact. With already declining crayfish populations, decreases in species and genetic diversity due to impoundments can decrease the persistence of hundreds of crayfish species in thousands of impounded streams. These changes in crayfish populations can cause cascading effects throughout stream ecosystems by altering the numerous ecosystem services provided by crayfishes

Ruby\u27s Choice, 1989

1989 Menu from Ruby\u27s Choice restaurant, 116 Free Street. The popular lunch spot was a perennial winner of newspaper readers\u27 polls for best burger in Portland, and was in business on Free Street from late 1985 through 1997.1986 Photographs of Ruby\u27s Choice can be seen at this link.https://digitalcommons.portlandlibrary.com/menus/1048/thumbnail.jp

Optimizing an Electron\u27s Path to Ionization Using a Genetic Algorithm

A Rydberg atom is an atom with a highly excited and weakly bound valence electron. A widespread method of studying quantum mechanics with Rydberg atoms is to ionize the electron and measure its arrival time. We use a Genetic Algorithm (GA) to control the electron\u27s path to ionization. The Rydberg electron\u27s energy levels are strongly shifted by the presence of an electric field. The energy levels shift and curve, but never cross. At an avoided crossing the electron can jump from one level to the next. By engineering the electric field\u27s time dependence, we thereby control the path to ionization. A GA is an optimization method modeled on natural selection. We use a GA to evolve electric field pulses to achieve a target path to ionization. Our algorithm initially generates random members of a population and then assigns each member a fitness score based on how well they achieve our target solution. We use elitism to pass the best members of the population directly into the next generation. We use tournament style selection to choose fit members to mate and pass their genes to the next generation. We then mutate the offspring to provide genetic diversity to our population. We present our results on the effects of varying GA parameters and modifying the GA to better model the experiment

Commentary: Data storytelling to aid health system decision-makers with population health issues for a specific location

Modern society is awash in data for health science, health system, and public health decision-making. These public data are often presented in various formats: Data tables, reports with data and bar charts, press releases with data, dashboards of key performance indicators, the traditional professional paper with data table and statistical results, etc. Software can display these data in various ways. The tacit assumption is that the reader/consumer of the data has the means to interpret these often complex health data for individual use and professional decision-making. We do not think that it is reasonable to make this assumption in all situations. Instead, maybe those of us who collect and analyze health data should include data storytelling as a way to make it easier for health system decision-makers to know and appreciate the next steps to be taken in the decision-making process given the data we prepared. The interpretation of data for action using a charticle and other techniques of infographics and health data storytelling may be more useful to health system decision-makers than the presentation of detailed facts and data and a scientific interpretation of those facts and data. This commentary illustrates the process of data storytelling using a charticle to help health system decision-makers interpret health data and use it as a foundation for action

Food Safety Audits, Plant Characteristics, and Food Safety Technology Use in Meat and Poultry Plants

Food safety technology can increase a company’s capacity to prevent a foodborne contamination. A food safety audit—a quality control tool in which an auditor observes whether a plant’s processing practices and technologies are compatible with good food safety practices—can indicate how effectively food safety technology is being used. Fast food restaurants, grocery stores, and other major customers of meat and poultry processing plants conduct their own audits or hire auditors to assess the soundness of a plant’s processing operation. Meat and poultry plants can also audit themselves as a way to help maintain process control. In this report, we document the extent of food safety audits in meat and poultry processing plants. We also examine the associations between the use of audits and plant size, firm structure, and food safety technology use. Results show that larger plants, plants subject to food safety audits, and plants that are part of a multiplant firm use more food safety technology than other plants. Plants subject to both plant-hired and customer-hired audits had greater technology use than single (plant- or customer-hired) audit plants.Meat and poultry processing, safety standards, product recalls, food safety technology, food safety audits, Agribusiness, Food Consumption/Nutrition/Food Safety, Industrial Organization, Livestock Production/Industries,

Awareness of Secondary School Students’ Usage of Mobile Devices for Learning

This study was designed to justify the importance of student’s readiness in resource utilization hence the study investigated senior secondary school students’ level of awareness on the usage of mobile devices for learning purposes. It adopted the descriptive design. A sample of 375 senior school II students data were used. The instrument titled Questionnaire for Students’ Awareness on Mobile Devices Usage for Instructional Purposes (QSAMDU) was developed with a reliability coefficient of 0.89. Data gathered were analyzed using standard deviation and meanwhile, the hypothesis was tested using the independent t-test. The findings revealed that students level of awareness for the use of the mobile device for learning was high and positive while showing that their level of awareness was not dependent on gender. The researchers, therefore, recommend that educators should classify their learners more accurately and adapt their teaching strategies to provide appropriate learning assistance to the learners as they engage meaningfully with their mobile devices

Digital Devices and Digital Literacy Skills Among Library and Information Science Students in Niger Delta University, Wilberforce Island, Bayelsa State, Nigeria

The study focused on Digital Devices and Digital Literacy Skills Among Library and Information Science Undergraduate Students in Niger Delta University, Wilberforce Island, Bayelsa State, Nigeria. Survey design was used. The population of the study covered the 200 and 300-level students of the Department of Library and Information Science, Niger Delta University. The sample size of the study was 165. The total enumeration sampling technique was used to determine the sample size of the study. The instrument used for data collection was a self-constructed questionnaire. Descriptive statistics were used in the analysis. The findings revealed that students of LIS, Niger Delta University, use their own smartphones, laptops, and other types of digital devices. Poor information search skills, epileptic power supply, inability to provide internet connectivity with free access, inability to manage myriads of information sources, were some of the major challenges of the respondents. Arising from the findings, recommendations were made to include the provision of internet services within the school premises for easy access by students of LIS at all times so as to reduce the cost of data subscriptions for daily academic activities in order to keep pace with information creation use and knowledge sharing. Secondly, the issue of epileptic power supply should be tackled and alternatives provided

Factors leading to the establishment of child-headed households: the case of Zimbabwe

This paper analyses factors associated with the establishment of 43 child- and adolescent-headed households in Manicaland, Zimbabwe. Such households result from the rapid increase in numbers of parental deaths leading to overburdening of the capacity of relatives to fulfil their traditional role of caring for orphans. Most children living in child and adolescent headed households have had both parents die in the preceding five years; many of them receive regular visits and support from relatives. Child-headed households represent a new coping mechanism in response to the impact of AIDS on communities. Community groups can help extended families to cope with the burden of orphans by encouraging the establishment of volunteer-based visiting programs to atrisk households and by channelling essential material support to destitute families