High speed machining of space shuttle external tank liquid hydrogen barrel panel

Actual and projected optimum High Speed Machining data for producing shuttle external tank liquid hydrogen barrel panels of aluminum alloy 2219-T87 are reported. The data included various machining parameters; e.g., spindle speeds, cutting speed, table feed, chip load, metal removal rate, horsepower, cutting efficiency, cutter wear (lack of) and chip removal methods

TDOT 25-Year Long-Range Transportation Policy Plan, Safety, Security, and Transportation Reslience Policy Paper

https://digitalcommons.memphis.edu/govpubs-tn-dept-transportation-25-year-transportation-policy/1003/thumbnail.jp

Application of IHSDM: KY 30 Case Study

A section of KY 30 in Jackson and Owsley Counties is targeted for redesign to provide a safer and more efficient corridor that will support economic activity in eastern Kentucky. Data for the existing KY 30 alignment and eight alternative alignments developed by HMB Professional Engineers Inc. were provided to researchers at the Kentucky Transportation Center (KTC). KTC researchers also developed a new alternative that modified the existing alignment to improve the safety of various locations. Researchers applied safety analysis procedures from Part C of the Highway Safety Manual (HSM) to the existing and alternative alignments of KY 30 using the Interactive Highway Safety Design Model (IHSDM). The resulting crash predictions were used to analyze each alternative and perform a benefit-cost analysis. Each alignment’s safety benefits were derived by calculating the total reduction in crashes (i.e., subtracting the number of crashes anticipated for an alternative from the number of crashes that would be expected if the segment were not redesigned). Comprehensive crash costs from the National Safety Council (NSC) were applied to the reduction in crashes to estimate, in monetary terms, the safety benefit. This figure was compared to the estimated cost of each project. KTC’s modified existing alignment had a benefit-cost (B/C) ratio of 0.14, meaning project’s cost outweighs the expected safety benefits. The other new build alternatives had negative B/C ratios, meaning the cost of crashes is expected to increase after their implementation. The increase in crash costs for the new build alternatives is due to the increase in crash severity expected on the new alignments coupled with the current alignment remaining a source of crashes (as the latter would remain open to facilitate the mobility of residents). IHSDM analysis only captures expected safety benefits, however. The selected alternative may be economically justifiable based on a holistic evaluation of the potential benefits it offers — in addition to safety benefits. The potential non-safety benefits of each project alternative should be analyzed to inform and improve the decision-making process for the KY 30 redesign

Communicating health decisions: an analysis of messages posted to online prostate cancer forums

Background  Experiential websites such as message forums and blogs allow Prostate Cancer (PCa) patients to communicate their health decisions to peers. The issues surrounding this form of indirect involvement in public health are little understood. Objective  This paper explores the types of decision-making processes that people are exposed to on PCa online message boards. The kinds of treatment choices patients are making and the reports of their decision-making processes to peers through an online environment are examined in the context of the Heuristic Systematic Model. Method  Messages about treatment decision making were collected from four PCa websites. In total, 137 messages were selected from blogs and online forums and their decision-making processes coded. Results  Men looking online for information about treatment options for PCa are exposed to a range of decision-making processes. Just under half (49.6%) of the messages reported non-systematic decision processes, with deferral to the doctor and proof of cancer removal being the most common. For systematic processing (36.5%), messages most commonly considered treatment outcomes and side-effects. Processes did not vary between the blogs and online forums. Discussion and conclusion  Compared to previous studies far fewer messages reported non-systematic decision processes and only a small number of messages reflected lay beliefs or misbeliefs about PCa treatment. Implications for men and their clinicians of seeking health information online are discussed

Paying for outpatient care in rural China:cost escalation under China's New Co-operative Medical Scheme

China’s New Co-operative Medical Scheme (NCMS), a government-subsidized health insurance programme, was launched in 2003 in response to deterioration in access to health services in rural areas. Initially designed to cover inpatient care, it has begun to expand its benefit package to cover outpatient care since 2007. The impacts of this initiative on outpatient care costs have raised growing concern, in particular regarding whether it has in fact reduced out-of-pocket (OOP) payments for services among rural participants. This study investigates the impacts on outpatient costs by analysing data from an individual-level longitudinal survey, the China Health and Nutrition Survey, for 2004 and 2009, years shortly before and after NCMS began coverage of outpatient services in 2007. Various health econometrics strategies were employed in the analysis of these data, including the Two-Part Model, the Heckman Selection Model and Propensity Score Matching with the Differences-in-Differences model, to estimate the effects of the 2007 NCMS initiative on per episode outpatient costs. We find that NCMS outpatient coverage starting in 2007 had little impact on reducing its participants’ OOP payments for outpatient services. The new coverage may also have contributed to an observed increase in total per episode outpatient costs billed to the insured patients. This increase was more pronounced among village clinics and township health centres—the backbone of the health system for rural residents—than at county and municipal hospitals

The optimum size of the portuguese public hospital

A Work Project, presented as part of the requirements for the Award of a Masters Degree in Economics from the NOVA – School of Business and EconomicsIn a context of intensive structural reform, this paper estimates optimum bed-sizes for the Portuguese public hospitals. Considering costs and production data for the period 2003-2006, we estimate a production-theoretic quadratic cost-function, adjusted to better describe the underlying technology. Room for short-run scale-economies exploitation is found, but long-run scale-diseconomies are unambiguous. In light of these predictions and of an optimum around 233 fully-occupied beds, there is mixed evidence of potential gains from two hospital mergers and from one of the forthcoming constructions of public hospitals. The results are expected to contribute to shape the hospital network in a cost-efficient manner

Developing a Competency Model for Highway Safety Engineers: A Delphi Method

The primary purpose of this study was to determine the core competencies needed by State DOT Highway Safety Engineers as perceived by Highway Safety experts in the United States. First, a list of competencies was identified. Next, a panel of Highway Safety experts determined the importance of each identified competency for the current year (2020) and for the future (year 2030). Finally, ratings provided by the panel were tested for the presence of consensus. For this study, the researcher used a Delphi Method as classified by Delbecq, Van de Ven, and Gaustafson (1975). Through this method, a panel of forward-thinking experts in the field of Highway Safety were surveyed to find consensus of important and needed technical competencies for current and future Highway Safety Engineers (Gupta & Clarke, 1996). Through three rounds, these panel members were able to suggest and rate competencies, with the option to provide any feedback they deemed necessary. Based on previous literature, a review of various professional organizations, and extensive interviews, 50 competencies were generated. During Round 1, this list of competencies was sent to identified highway safety experts across the U.S. and asked, “Is this competency important for Highway Safety Engineers for the year 2020 (or 2030)?” Here, the panel suggested edits to 9 currently listed competencies and defined 18 additional competencies. In Round 2, participants rated all 68 competencies on a five-point anchored scale. In Round 3, the panel was provided the median scores for each competency listed in Round 2 and asked to keep or change their rating to match the group’s rating and provide any justification as necessary. At the conclusion of Round 3, all competencies were listed as achieving consensus as established a’ priori at greater than 50% indicating a set of core competencies essential to the role of Highway Safety engineers in the year 2020 and 2030. Since the panel was shown to be effective and forward-thinking in their views, the researcher recommends state DOTs and national organizations involved in trainings regarding highway safety engineers move toward the inclusion of all competencies rated substantial or high importance in required training

Pilot to improve linkage of domestic tomato supply chains to local high segment markets

The pilot aims to link smallholder tomato farmers in both Kenya and Tanzania to local high segment markets as supermarkets, hotels, restaurants and hospitals

Towards poly-crystalline silicon thin film solar cells : on the microstructure and the crystallization kinetics of hydrogenated amorphous silicon

Amongst the thin-film based approaches for photovoltaics, which aim to combine high conversion efficiencies (> 10%) and low cost manufacturing (<1$/Wp), poly-crystalline silicon (poly-Si) based solar cells (<10 µm thick) are nowadays considered a promising candidate. Poly-Si couples the high quality crystalline Si technology with the potential for large area and low-cost thin film manufacturing. One of the most followed approaches is the development of poly- Si on inexpensive (e.g. glass) substrates upon solid-phase crystallization (SPC), i.e. an annealing procedure under a controlled temperature ramp up to 600-650 °C, of plasma- deposited amorphous silicon (a-Si:H) films. Here the challenge is the development of large (in the range of few µm) grain poly-Si and large area, high growth rate a-Si:H films have generated in the recent years several (fundamental) research questions. Among these, the impact of the a-Si:H microstructure on the crystallization kinetics (incubation-nucleation-grain development) represents the key towards large grain poly-Si and process up-scaling. The approach chosen in this Ph.D. project initiates from the development of state-of-the art poly-Si layers characterized by grain sizes developing up to a 1 µm in diameter, as obtained upon SPC of expanding thermal plasma deposited a-Si:H layers [1]. Furthermore, a selected experimental approach based on an extensive use of in situ and ex situ surface and bulk film diagnostics is applied with the purpose of disclosing the impact of the a-Si:H film properties on the crystallization kinetics. In particular, a-Si:H bulk parameters such as the hydrogen content and microstructure parameters (hydrogen distribution in several SiHx configurations, medium range order) are studied in depth [2-3]. In detail, larger grains are found to be promoted by an increase in the a-Si:H microstructure parameter R* [2]. R* represents the order (low R*)/disorder (high R*) in the matrix according to the Si-H bond distribution in mono-/di-vacancies (–low stretching mode-LSM) and nano-sized voids (–high stretching mode-HSM), and it is quantified by the integrated IR absorption band ratio IHSM/ (ILSM+IHSM). Furthermore, the incubation time towards nuclei formation appears to be not only controlled by the medium range order in the a-Si:H films, as previously reported in literature, but also by the density of nano-sized voids which undergo a faster hydrogen out-diffusion and chemical bond rearrangement towards a higher medium range order and more ordered microstructure. Next to the insight into the impact of the a-Si:H properties on the crystallization kinetics, an in-depth study is also devoted to the control of the a-Si:H properties by means of a proper tuning of film growth- related parameters such as the ion flux and energy involved during the plasma deposition of thin a-Si:H layers [4]. In view of the manufacturing challenges of high throughput, the expanding thermal plasma approach is further explored [5] for the deposition of high growth rate a-Si:H films, in the range of 11- 58 nm/s. Poly-Si layers characterized by large grains (~1.5 µm) were obtained from disordered a-Si:H films deposited at 11- 25 nm/s. The study confirmed the role of the medium range order and the R* parameter in affecting the crystallization kinetics of a-Si:H, i.e. the incubation time and the grain size development, respectively. The present thesis addresses the results of the research efforts towards high conversion efficiency, high throughput thin-¿lm poly-Si solar cells. It addresses a significant contribution to the insight on the SPC kinetics, the impact of a-Si:H microstructure on the incubation step and grain development and demonstrates the potential for large grain (~1.5 µm), high growth rate (~25 nm/s) poly-Si from SPC of ETP deposited a-Si:H films