Uncertainty Analysis for the Evaluation of a Passive Runway Arresting System

This paper considers the stopping distance of an aircraft involved in a runway overrun incident when the runway has been provided with an extension comprised of a material engineered to induce high levels of rolling friction and drag. A formula for stopping distance is derived that is shown to be the product of a known formula for the case of friction without drag, and a dimensionless constant between 0 and 1 that quantifies the further reduction in stopping distance when drag is introduced. This additional quantity, identified as the Drag Reduction Factor, D, is shown to depend on the ratio of drag force to friction force experienced by the aircraft as it enters the overrun area. The specific functional form of D is shown to depend on how drag varies with speed. A detailed uncertainty analysis is presented which reveals how the uncertainty in estimates of stopping distance are influenced by experimental error in the force measurements that are acquired in a typical evaluation experiment conducted to assess candidate overrun materials

Social Attitudes of Field Instructors

In both the classroom setting and field practicum, social work students begin to develop competence in practice with diverse populations. Field instructors play a critical role in educating students on diversity issues and preparing students to practice without bias. A cross-sectional study was conducted to better understand social attitudes of field instructors participating in a Seminar in Field Instructor (SIFI) training (N=88). The field instructors had generally positive attitudes. Results indicated that field instructors’ comfort level and demographic variables were predictors of social attitudes. Implications for social work field instruction are discussed

TACT: A Set of MSC/PATRAN- and MSC/NASTRAN- based Modal Correlation Tools

This paper describes the functionality and demonstrates the utility of the Test Analysis Correlation Tools (TACT), a suite of MSC/PATRAN Command Language (PCL) tools which automate the process of correlating finite element models to modal survey test data. The initial release of TACT provides a basic yet complete set of tools for performing correlation totally inside the PATRAN/NASTRAN environment. Features include a step-by-step menu structure, pre-test accelerometer set evaluation and selection, analysis and test result export/import in Universal File Format, calculation of frequency percent difference and cross-orthogonality correlation results using NASTRAN, creation and manipulation of mode pairs, and five different ways of viewing synchronized animations of analysis and test modal results. For the PATRAN-based analyst, TACT eliminates the repetitive, time-consuming and error-prone steps associated with transferring finite element data to a third-party modal correlation package, which allows the analyst to spend more time on the more challenging task of model updating. The usefulness of this software is presented using a case history, the correlation for a NASA Langley Research Center (LaRC) low aspect ratio research wind tunnel model. To demonstrate the improvements that TACT offers the MSC/PATRAN- and MSC/DIASTRAN- based structural analysis community, a comparison of the modal correlation process using TACT within PATRAN versus external third-party modal correlation packages is presented

ABSTRACT TACT: A SET OF MSC/PATRAN- & MSC/NASTRAN-BASED MODAL CORRELATION TOOLS

This paper describes the functionality and demonstrates the utility of the Test Analysis Correlation Tools (TACT), a suite of MSC/PATRAN Command Language (PCL) tools which automate the process of correlating finite element models to modal survey test data. The initial release of TACT provides a basic yet complete set of tools for performing correlation totally inside the PATRAN/NASTRAN environment. Features include a step-by-step menu structure, pre-test accelerometer set evaluation and selection, analysis and test result export/import in Universal File Format, calculation of frequency percent difference and cross-orthogonality correlation results using NASTRAN, creation and manipulation of mode pairs, and five different ways of viewing synchronized animations of analysis and test modal results. For the PATRAN-based analyst, TACT eliminates the repetitive, time-consuming and error-prone steps associated with transferring finite element data to a thirdparty modal correlation package, which allows the analyst to spend more time on the more challenging task of model updating. The usefulness of this software is presented using a case history, the correlation for a NASA Langley Research Center (LaRC) low aspect ratio research wind tunnel model. To demonstrate the improvements that TACT offers the MSC/PATRAN- and MSC/NASTRAN-based structural analysis community, a comparison of the modal correlation process using TACT within PATRAN versus external thirdparty modal correlation packages is presented

An innovative biofloc technology for the nursery production of Pacific whiteleg shrimp, Penaeus vannamei in tanks

Nursery production of shrimp is usually done in small ponds; however, the use of small and circular tanks with plastic liners is gaining popularity. From an industry standpoint, there is still a need to assess how nursery systems can be of benefit to the shrimp production cycle. Hence, the use of small circular tanks coupled with the incorporation of biofloc technology was assessed in terms of its viability during the nursery production of the Pacific whiteleg shrimp, Penaeus vannamei. A 450m2 plastic lined circular tank was installed and prepared for the stocking of P. vannamei postlarvae (PLs) at a density of 500 PLs per m2. Biofloc was produced and maintained throughout the nursery phase using brown sugar as carbon source at a carbon to nitrogen (C:N) ratio of 10. Water quality was monitored daily, while presumptive Vibrios were enumerated weekly. Sampling for growth was done at the 14th day post-stocking and weekly until harvest on the 30th day. The different water quality parameters were within optimum levels required for shrimp growth. Presumptive Vibrios were dominated by the yellow colonies. At the end of the nursery phase, there was 100% survival and the shrimp attained an average body weight of 1.26 g and a feed conversion ratio (FCR) of 0.43. Our results indicate that the use of small circular tanks with biofloc during the nursery production phase of whiteleg shrimp is feasible and can be incorporated in the grow-out culture of this shrimp species.This research study is part of the project, “Bioflocbased Nursery Tank Production of Shrimp for Quality and Sustainable Supply of Aquaculture Products in the New Normal” funded by the Department of Science and Technology (DOST) through the Science for Change Program (S4CP) – Collaborative Research and Development to Leverage Philippine Economy (CRADLE) and monitored by DOST – Philippine Council for Agriculture, Aquatic and Natural Resources Research and Development (PCAARRD) with Project Number 8444 awarded to CMA Caipang. The support provided by our respective institutional affiliations and Marmi Agricultural Corporation is gratefully acknowledged

Innofloc: Innovative biofloc technology for the nursery production of shrimp, Litopenaeus vannamei in tanks

Nursery systems are valuable production tools in shrimp aquaculture and are effective biosecurity facilities for the high-density culture of shrimp postlarvae (PL), resulting in healthy and uniform-sized juveniles. The nursery production of shrimp is usually carried out in small ponds; however, the use of small and circular tanks with plastic liners is gaining popularity. From an industry standpoint, there is a need to assess how nursery systems can improve the productivity of the shrimp production cycle. Hence, the use of small circular tanks coupled with the incorporation of biofloc technology was assessed in terms of its viability during the nursery production of the Pacific whiteleg shrimp, Litopenaeus vannamei. A 450m2 plastic-lined circular tank was installed and prepared for the stocking of L. vannamei postlarvae (PLs) at a density of 500 PLs per m2. Biofloc was produced and maintained throughout the nursery phase by adding brown sugar as a carbon source at carbon to nitrogen (C:N) ratio of 10. Daily monitoring of the various water quality parameters was carried out, while presumptive Vibrios were enumerated weekly. The shrimp juveniles were sampled for their body weight on the 14th day post-stocking and weekly until harvest on the 30th day of culture. The different water quality parameters were within optimum levels required for shrimp growth. Presumptive Vibrios were dominated by the yellow colonies. The shrimp attained 100% survival with an average body weight of 1.26 g and a feed conversion ratio (FCR) of 0.43 at the end of the nursery production phase. Our results indicate that the use of small circular tanks with biofloc during the nursery production phase of whiteleg shrimp is feasible and can be incorporated during the grow-out culture for improved and continuous production of this shrimp species.Department of Science and Technology (DOST) through the Science for Change Program (SC4P) – Collaborative Research and Development to Leverage Philippine Economy (CRADLE) for the funding and the Philippine Council for Agriculture, Aquatic and Natural Resources Research and Development (PCAARRD) for assisting and monitoring the project activities

Regional Research-Practice-Policy Partnerships in Response to Climate-Related Disparities: Promoting Health Equity in the Pacific.

Although climate change poses a threat to health and well-being globally, a regional approach to addressing climate-related health equity may be more suitable, appropriate, and appealing to under-resourced communities and countries. In support of this argument, this commentary describes an approach by a network of researchers, practitioners, and policymakers dedicated to promoting climate-related health equity in Small Island Developing States and low- and middle-income countries in the Pacific. We identify three primary sets of needs related to developing a regional capacity to address physical and mental health disparities through research, training, and assistance in policy and practice implementation: (1) limited healthcare facilities and qualified medical and mental health providers; (2) addressing the social impacts related to the cooccurrence of natural hazards, disease outbreaks, and complex emergencies; and (3) building the response capacity and resilience to climate-related extreme weather events and natural hazards

Management of coronary disease in patients with advanced kidney disease

BACKGROUND Clinical trials that have assessed the effect of revascularization in patients with stable coronary disease have routinely excluded those with advanced chronic kidney disease. METHODS We randomly assigned 777 patients with advanced kidney disease and moderate or severe ischemia on stress testing to be treated with an initial invasive strategy consisting of coronary angiography and revascularization (if appropriate) added to medical therapy or an initial conservative strategy consisting of medical therapy alone and angiography reserved for those in whom medical therapy had failed. The primary outcome was a composite of death or nonfatal myocardial infarction. A key secondary outcome was a composite of death, nonfatal myocardial infarction, or hospitalization for unstable angina, heart failure, or resuscitated cardiac arrest. RESULTS At a median follow-up of 2.2 years, a primary outcome event had occurred in 123 patients in the invasive-strategy group and in 129 patients in the conservative-strategy group (estimated 3-year event rate, 36.4% vs. 36.7%; adjusted hazard ratio, 1.01; 95% confidence interval [CI], 0.79 to 1.29; P=0.95). Results for the key secondary outcome were similar (38.5% vs. 39.7%; hazard ratio, 1.01; 95% CI, 0.79 to 1.29). The invasive strategy was associated with a higher incidence of stroke than the conservative strategy (hazard ratio, 3.76; 95% CI, 1.52 to 9.32; P=0.004) and with a higher incidence of death or initiation of dialysis (hazard ratio, 1.48; 95% CI, 1.04 to 2.11; P=0.03). CONCLUSIONS Among patients with stable coronary disease, advanced chronic kidney disease, and moderate or severe ischemia, we did not find evidence that an initial invasive strategy, as compared with an initial conservative strategy, reduced the risk of death or nonfatal myocardial infarction

Health status after invasive or conservative care in coronary and advanced kidney disease

BACKGROUND In the ISCHEMIA-CKD trial, the primary analysis showed no significant difference in the risk of death or myocardial infarction with initial angiography and revascularization plus guideline-based medical therapy (invasive strategy) as compared with guideline-based medical therapy alone (conservative strategy) in participants with stable ischemic heart disease, moderate or severe ischemia, and advanced chronic kidney disease (an estimated glomerular filtration rate of <30 ml per minute per 1.73 m2 or receipt of dialysis). A secondary objective of the trial was to assess angina-related health status. METHODS We assessed health status with the Seattle Angina Questionnaire (SAQ) before randomization and at 1.5, 3, and 6 months and every 6 months thereafter. The primary outcome of this analysis was the SAQ Summary score (ranging from 0 to 100, with higher scores indicating less frequent angina and better function and quality of life). Mixed-effects cumulative probability models within a Bayesian framework were used to estimate the treatment effect with the invasive strategy. RESULTS Health status was assessed in 705 of 777 participants. Nearly half the participants (49%) had had no angina during the month before randomization. At 3 months, the estimated mean difference between the invasive-strategy group and the conservative-strategy group in the SAQ Summary score was 2.1 points (95% credible interval, 120.4 to 4.6), a result that favored the invasive strategy. The mean difference in score at 3 months was largest among participants with daily or weekly angina at baseline (10.1 points; 95% credible interval, 0.0 to 19.9), smaller among those with monthly angina at baseline (2.2 points; 95% credible interval, 122.0 to 6.2), and nearly absent among those without angina at baseline (0.6 points; 95% credible interval, 121.9 to 3.3). By 6 months, the between-group difference in the overall trial population was attenuated (0.5 points; 95% credible interval, 122.2 to 3.4). CONCLUSIONS Participants with stable ischemic heart disease, moderate or severe ischemia, and advanced chronic kidney disease did not have substantial or sustained benefits with regard to angina-related health status with an initially invasive strategy as compared with a conservative strategy