Advanced ramjet concepts program

Uniquely advantageous features, on both the performance and weight sides of the ledger, can be achieved through synergistic design integration of airbreathing and rocket technologies in the development of advanced orbital space transport propulsion systems of the combined cycle type. In the context of well understood advanced airbreathing and liquid rocket propulsion principles and practices, this precept of synergism is advanced mainly through six rather specific examples. These range from the detailed component level to the overall vehicle system level as follows: using jet compression; achieving a high area ratio rocket nozzle; ameliorating gas generator cycle rocket system deficiencies; using the in-duct special rocket thrust chamber assembly as the principal scramjet fuel injection operation; using the unstowed, covered fan as a duct closure for effecting high area ratio rocket mode operation; and creating a unique airbreathing rocket system via the onboard, cryogenic hydrogen induced air liquefaction process

Plantar Fasciitis: Etiology and Treatment

Plantar fasciitis is a repetitive injury which causes microtrauma to the attachment of the plantar aponeurosis at the medial calcaneous of the foot. This condition is most prevalent among athletes involved in running sports, but can also occur in a sedentary individual who is overweight. Traditional treatments for plantar fasciitis, including rest, ice, anti-inflammatory drugs, and passive modalities, are helpful in temporarily reducing inferior heel pain. However, recurrence of this condition is common because the potential biomechanical causes of plantar fasciitis are often left unidentified. The purpose of this study is to review the anatomical structures and the biomechanical functions of the plantar fascia, to describe mechanical and non-mechanical etiologic factors involved in plantar fasciitis, and to analyze the inflammatory tissue response of this fibrous connective tissue. Furthermore, the literature review outlines a comprehensive rehabilitation treatment plan, including a conservative course of treatment using therapeutic exercises, taping techniques, and orthotic devices as well as possible surgical procedures in the most severe cases

Improving Reading Skills in Social Studies

The focus of this study was to determine whether the introduction of reading strategies in the social studies classroom could increase student achievement in social studies. The study collected data from ninth graders in a regular educational Global Studies classroom. Student-generated data collected included formative assessments such as pre and post-tests, map quizzes, unit tests and exit slips. Reading strategies outcomes were analyzed from a student perspective via student exit slips and information gathered instudent-teacher conferencing. The implementation of the reading strategy was successful. Statistics showed greater improvement for girls than for boys. The majority of students found the introduction of reading strategies beneficial for social studies. Implementing graphic organizers and other reading strategies will be implemented in future courses

Selection Portfolio: Applying Modern Portfolio Theory to Personnel Selection

Modern Portfolio Theory (MPT) is a framework for building a portfolio of risky assets such that the ratio of risk to return is minimized. While this theory has been used in the field of financial economics for over sixty years, the method has not yet been applied to compensatory personnel selection. A common method for personnel selection is multiple regression to maximize the predicted performance of the selected group given a cut-off score on the predictor(s). Recognizing that maximizing the performance of the selected group is not the only consideration, and that, for many jobs and organizations, the outcomes of false positives and false negatives can be drastically different in terms of costs, is central to this study. MPT is offered as an additional method for generating weights that produce fewer false positives than multiple regression. MPT generates a set of all possible combinations of predictors within the plane of risk and return and finds an optimal set of weights on the efficient frontier, the hyperbola that represents the best possible set of trade-offs between risk and return. This study uses Monte Carlo simulations to estimate boundary conditions where MPT can outperform multiple regression. Comparisons are drawn between MPT, multiple regression, and unit weighting, applying weights uniformly across all predictors. Comparisons between the methods are drawn consistent with Signal Detection Theory, categorizing prediction-criterion pairs in terms of correct selections, false positives, correct rejections, and false negatives. Boundaries for suitability for initial sample size, applicant pool size, and cutoff score of the performance measure are explored. Finally, an application of MPT for reducing adverse impact and promoting diversity by choosing combinations of variables that reduce the weight given to cognitive ability is explored

Working And Providing Care: Increasing Student Engagement For Part-Time Community College Students

The purpose of this study was to examine the relationship among external time obligations of work and care giving by part-time students, their participation within structured group learning experiences, and student engagement. The Structured Group Learning Experiences (SGLEs) explored within this study include community college programming activities of orientation, accelerated developmental education, first-year experience courses, student success courses, and learning communities. Student engagement was measured by the Community College Survey of Student Engagement (CCSSE) Benchmark values. The focus of this research was to explore how differing levels of time spent working for pay and in providing care for dependents impacted participation within structured group learning experiences and student engagement. The data set used for this study was a random subset of the 2014 CCSSE Cohort with survey results from the CCSSE instrument and the CCSSE Special-Focus Items survey. The study found significant relationships between SGLE participation and student engagement with a cumulative effect related to multiple SGLE participation and higher student engagement. The relationship between time spent working for pay and in providing care for dependents was found to have differing impacts on student engagement. The study found time spent working for pay was connected to lower student engagement scores while time spent providing care for dependents had mixed results with some connection to higher engagement scores. This trend was also found in the participation within SGLEs of part-time students. Time spent working for pay was connected to lower participation within SGLEs for part-time students whereas time spent providing care for dependents had limited connections to higher participation within orientation, accelerated developmental education, and student success courses. The key finding of this study showed that time spent providing care for dependents was associated with higher levels of student engagement and limited increases in SGLE participation as opposed to time spent working for pay. Community college professionals can learn from this result, and perhaps, pursue ways to support their students who are navigating these external time obligations. Keywords: Student Engagement, Structured Group Learning Experiences, Community College Survey of Student Engagement, Work for Pay, Caregivin

Assessing a need for a one-stop shop disaster management mobile application by identifying the perceptions and utilization of current disaster preparedness resources in southern Louisiana

The purpose of this sequential explanatory mixed method study was to assess the need for a “one-stop shop” disaster management mobile application. This was done by identifying the perceptions and utilization of current disaster preparedness resources in the southern region of the United States. The perceptions and utilization levels were measured by obtaining statistical, quantitative results from the Leingang Disaster Preparedness and Utilization survey. Individuals at four universities in the Southern disaster prone area of Louisiana were surveyed. The survey yielded a preparedness score for each survey participant. The preparedness score was achieved based on subsequent scores in three categories: knowledge, usage, and technology. Knowledge was defined as simply knowing about that the preparedness resource available. Usage was defined as participants knowing that the resources existed and whether they chose to use it or not. Technology was identified as any medium the participant used to assist in their hurricane preparedness efforts. This included anything from printed resources to mobile applications. Respondents that identified they were available for more in-depth interviews that had the highest and lowest scores at each institution were contacted to further explore their survey results. The availability of a “one-stop shop” disaster management mobile application that is utilized before, during, and after a disaster would allow Louisiana residents to have one place to access the various emergency preparedness resources that are available for them. This study found that residents would be interested in utilizing a “one-stop shop” mobile application during disasters and therefore the researcher recommend modifying current disaster management mobile applications in order to meet this need

Biomaterials Redesign of Microvascular Anastomotic Coupler

The key factors in the redesign of this part include the use of biomaterials, the redesign of the part geometry to include these biomaterials, and the proposition of production scale manufacturing methods suitable for these redesigns. The choice of biodegradable material was guided by previous literature, during which we found the PLGA polymer used in similar predicate devices with a biodegradability timeline similar to our goals. The model of coupler serving as the inspiration for the redesign utilizes two very strong but bioinert materials, polyethylene, and stainless steel. These high strength materials can withstand much greater forces than the biodegradable bulk material chosen for the redesign, so features of the old design were modified for robustness. This included to realize this new design on a production scale, the two most promising possibilities include injection molding with the PLGA polymer or additive manufacturing using stereo lithography printers and biodegradable resins. The commonality of these two processes is the ability to make complex shapes while retaining isotropic materials in the final part, which is essential for the strength of small features such as the pins. Key customer requirements for anastomotic procedures include successful attachments of vessels and low rates of dehiscence. These requirements are related to our coupler by successful attachment rate, max force withstood by coupler before assembly separates, max forces withstood by vessels before ripping. Different models of the coupler device were tested in assembled orientation with one blood vessel surrogate engaged. In both models, tensions upwards of 100N were experienced without a signal failure of the pins. This demonstrates that the pins are exceptionally stronger when assembled into the opposite coupler than when unengaged. Another factor in the improvement of the device is the time taken to film an implementation of the device using dissected cow arteries. The first round of prototypes required several people to affix the coupler and blood vessels and required additional processing of the cow arteries in the form of puncturing pilot holes for the spikes. Overall, the procedure took about an hour to perform. The latest model of prototypes was operated on in only a half hour and required only one person to perform the procedure. The improved placement and orientation of the spikes allow for much easier puncturing of the arterial wall for smoother attachments