Probabilistic Fracture Mechanics and Optimum Fracture Control Analytical Procedures for a Reusable Solid Rocket Motor Case

A methodology for the reliability analysis of a reusable solid rocket motor case is discussed. The analysis is based on probabilistic fracture mechanics and probability distribution for initial flaw sizes. The developed reliability analysis is used to select the structural design variables of the solid rocket motor case on the basis of minimum expected cost and specified reliability bounds during the projected design life of the case. Effects of failure prevention plans such as nondestructive inspection and the material erosion between missions are also considered in the developed procedure for selection of design variables. The reliability-based procedure can be modified to consider other similar structures of reusable space vehicle systems with different failure prevention plans

Probabilistic fracture mechanics and optimum fracture control of the solid rocket motor case of the shuttle

Development of a procedure for the reliability analysis of the solid rocket motor case of the space shuttle is described. The analysis is based on probabilistic fracture mechanics and consideration of a probability distribution for the initial flaw sizes. The reliability analysis can be used to select design variables, such as the thickness of the SRM case, projected design life and proof factor, on the basis of minimum expected cost and specified reliability bounds. Effects of fracture control plans such as the non-destructive inspections and the material erosion between missions can also be considered in the developed methodology for selection of design variables. The reliability-based procedure can be easily modified to consider other similar structures and different fracture control plans

Design of a device for drilling long, small-diameter tunnels

M.S.Robert B. Evan

A Patient\u27s Perspective on Lower Urinary Tract Symptoms

Lower urinary tract symptoms (LUTS) have been increasing in incidence and prevalence in the United States. With a large annual health care cost, an association with a significantly reduced quality of life, and an aging population, LUTS is increasingly becoming more of a burden on the health care system. The American Urological Association created a symptom index in 1992 that assesses for the severity of seven LUTS associated with benign prostatic hyperplasia. This project seeks to address the question of which symptoms from the index score are more common; whether certain symptoms are more concerning from a patient’s perspective.https://scholarworks.uvm.edu/fmclerk/1370/thumbnail.jp

Achieve complete robust path delay fault testability

Recently, Pomeranz and Reddy [7], presented a test point insertion method to improve path delay fault testability in large combinational circuits. A test application scheme was developed that allows test points to be utilized as primary inputs and primary outputs during testing. The placement of test points was guided by the number of paths and was aimed at reducing this number. Indirectly, this approach achieved complete robust path delay fault testability in very low computation times. In this paper, we use their test application scheme, however, we use morre exact measures for guiding test point insertion like test generation and RD fault identification. Thus, we reduce the number of test point needed to achieve complete testability by ensuring that test points are inserted only on paths associated with path delay faults that are necessary to be tested and that are not robustly testable. Experimental results show that an average reduction of about 70% in the number of test points over the approach of [7] can be obtained.

Patient Perspectives on Medication Assisted Therapy in Vermont

Introduction. Medication-Assisted Therapy (MAT) for opioid addiction has dramatically increased in Vermont, supported by a novel statewide system that integrates specialty treatment centers ( Hubs ) with primary care office-based opioid therapy ( Spokes ). In 2010, Vermont had the highest per capita buprenorphine use in the US. Previous studies of patient perspectives of MAT have identified social barriers, rigid program rules, and concerns about withdrawal and relapse as common causes of treatment failure. Our goal was to elicit patient perspectives on barriers and enablers of successful MAT to further inform system refinement. Methods. An interview guide was developed based on previous literature as well as discussions with program leadership, staff and clinicians, and community stakeholders. Responses were organized using thematic content analysis with consensus across seven interviewers and two analysts. The interviews were conducted with 44 patients enrolled in MAT at two Hub sites in Burlington, VT in October 2016. Results. The median age of subjects was 34 years, 34% were employed at least part-time, and 72% were female. Half reported a mental health condition and 20% reported chronic pain. Barriers included transportation (25%), lack of stable housing, and stigma (41%). Enablers included feeling supported (82% felt well-supported; 52% felt supported by healthcare professionals). Subjects expressed high confidence in the treatment system and high self-efficacy for sobriety. Conclusions. Patients in MAT have complex medical, mental health, social, personal, and work lives. A comprehensive system that addresses this wide range of domains is critical to achieving optimal outcomes.https://scholarworks.uvm.edu/comphp_gallery/1245/thumbnail.jp

Effective Utilization of Battery Banks In Multi-Level Inverters for a Residential Photovoltaic Applications

Distributed generation is key to improve reliability, reduced emission and improve power quality. In spite of high initial cost PV is forefront in renewable energy generation. For a residential PV installed application complete utilization of battery banks is key to reduce grid dependency and improve reliability. The present work introduces a novel methodology which leads to reduce the grid dependency and improve reliability for customer by making effective use of battery banks. In order to achieve above objective it’s important to keep battery banks difference or state of charges with in a threshold limit. This objective is attained by switching/shifting isolated panels. Selection of isolated panels through optimization by considering irregularity of roof top and worst case conditions. In addition, a control strategy is developed for switching isolated panels depending on difference in discharge levels. In addition, to decrease grid reliance and improve reliability a switching pattern is developed for a household installed PV system considering generation and load pattern. The present work is verified in MATLAB/Simulink environment

Perioperative nasal and paranasal sinus considerations in transsphenoidal surgery for pituitary disease

Endoscopic endonasal skull base surgery has emerged as the treatment modality of choice for a range of skull base lesions, particularly pituitary adenomas. However, navigation and manipulation of the nasal corridor and paranasal sinuses requires that surgeons are aware of effective techniques to maximize patient outcomes and avoid sinonasal morbidity postoperatively. This paper is a narrative review aimed to provide an updated and consolidated report on the perioperative management of the nasal corridor and paranasal sinuses in the setting of endoscopic skull base surgery for pituitary disease. Anatomic variants and common surgical techniques are discussed. Post-operative complications are evaluated in detail. Understanding the structural implications of the endonasal approach to the sphenoid is crucial to opti

Metastatic model of HPV+ oropharyngeal squamous cell carcinoma demonstrates heterogeneity in tumor metastasis

Human papillomavirus induced (HPV+) cancer incidence is rapidly rising, comprising 60–80% of oropharyngeal squamous cell carcinomas (OPSCCs); while rare, recurrent/metastatic disease accounts for nearly all related deaths. An in vivo pre-clinical model for these invasive cancers is necessary for testing new therapies. We characterize an immune competent recurrent/metastatic HPV+ murine model of OPSSC which consists of four lung metastatic (MLM) cell lines isolated from an animal with HPV+ OPSCC that failed cisplatin/radiation treatment. These individual metastatic clonal cell lines were tested to verify their origin (parental transgene expression and define their physiological properties: proliferation, metastatic potential, heterogeneity and sensitivity/resistance to cisplatin and radiation. All MLMs retain expression of parental HPV16 E6 and E7 and degrade P53 yet are heterogeneous from one another and from the parental cell line as defined by Illumina expression microarray. Consistent with this, reverse phase protein array defines differences in protein expression/activation between MLMs as well as the parental line. While in vitro growth rates of MLMs are slower than the parental line, in vivo growth of MLM clones is greatly enhanced. Moreover, in vivo resistance to standard therapies is dramatically increased in 3 of the 4 MLMs. Lymphatic and/or lung metastasis occurs 100% of the time in one MLM line. This recurrent/metastatic model of HPV+ OPSCC retains the characteristics evident in refractory human disease (heterogeneity, resistance to therapy, metastasis in lymph nodes/lungs) thus serving as an ideal translational system to test novel therapeutics. Moreover, this system may provide insights into the molecular mechanisms of metastasis