Reliability analysis of structural ceramic components using a three-parameter Weibull distribution

Described here are nonlinear regression estimators for the three-Weibull distribution. Issues relating to the bias and invariance associated with these estimators are examined numerically using Monte Carlo simulation methods. The estimators were used to extract parameters from sintered silicon nitride failure data. A reliability analysis was performed on a turbopump blade utilizing the three-parameter Weibull distribution and the estimates from the sintered silicon nitride data

The Geomorphology of Alluvial Fan Deposits on the West Flank of the Blue Ridge, Augusta County, Virginia

Large coalescing alluvial fans mantle the carbonate and shale formations west of the Blue Ridge mountains near Stuarts Draft, Virginia. Fan sediments are predominantly boulder and cobble gravels derived from the Antietam Quartzite, The fan complex consists of three alluvial units of significantly different ages. The surface of each fan unit was mapped using relative geomorphic position, soil color, clay content and thickness of Bt horizons, clast weathering, and degree of removal of depositional surfaces by stream incision. A five-category quartzite clast weathering scale developed for this study was very effective as a measure to distinguish map units. Stratigraphic data and statistical analyses of pedalogic data indicate that fluvial deposition on these fans occurred during discrete pulses separated by long periods of weathering and landscape stability. The map pattern of the three fan units show old fan remnants cluster near the distal margins of the fan complex and younger surfaces lie near the mountain front. Much of this spatial distribution results from the periodic capture of upland streams by piedmont streams. In addition solutional lowering of fan surfaces overlying the Shady Formation probably generated space for young fan sediments high on the fan complex. Order-of-magnitude age estimates are based upon comparisons of soil development and clast weathering criteria in these sediments with dated Coastal Plain deposits. This analysis suggests that the youngest fan deposits are late Pleistocene in age, the intermediate-age deposits are middle Pleistocene or older, and the oldest deposits are Pliocene or older

Reliability Analysis of Structural Ceramic Components Using a Three-parameter Weibull Distribution

This paper describes nonlinear regression estimators for the three-parameter Weibull distribution. Issues relating to the bias and invariance associated with these estimators are examined numerically using Monte Carlo simulation methods. The estimators were used to extract parameters from sintered silicon nitride failure data. A reliability analysis was performed on a turbopump blade utilizing the three-parameter Weibull distribution and the estimates from the sintered silicon nitride data

Evidencing the Need for a National Citizens Clothing Circularity Strategy (NCCCS), White Paper Scottish Parliament

No abstract available

Prevalence of Giardiasis in children Attending Semi-urban daycare centres in Guatemala and comparison of 3 Giardia detection tests

Giardia intestinalis is an intestinal parasite widely prevalent in children attending daycare centres worldwide and has been associated with undernutrition. Stool samples from 48 Guatemalan children (aged 1.5-7 years) attending participating daycare centres were analyzed over five weeks for presence of Giardia intestinalis using light microscopy, ELISA, and rapid dipstick test. Giardia prevalence rates were 43.7% at Week 0 and 44.7% at Week 4, based on ELISA. Intensity, but not prevalence, of infection showed a trend toward decreased weight-for-age (1-tailed p=0.08). We believe that ELISA analysis of stool samples may be further adapted for measuring the intensity of infection in humans

A primate model of severe malarial anaemia: a comparative pathogenesis study.

Severe malarial anaemia (SMA) is the most common life-threatening complication of Plasmodium falciparum infection in African children. SMA is characterised by haemolysis and inadequate erythropoiesis, and is associated with dysregulated inflammatory responses and reduced complement regulatory protein levels (including CD35). However, a deeper mechanistic understanding of the pathogenesis requires improved animal models. In this comparative study of two closely related macaque species, we interrogated potential causal factors for their differential and temporal relationships to onset of SMA. We found that rhesus macaques inoculated with blood-stage Plasmodium coatneyi developed SMA within 2 weeks, with no other severe outcomes, whereas infected cynomolgus macaques experienced only mild/ moderate anaemia. The abrupt drop in haematocrit in rhesus was accompanied by consumption of haptoglobin (haemolysis) and poor reticulocyte production. Rhesus developed a greater inflammatory response than cynomolgus macaques, and had lower baseline levels of CD35 on red blood cells (RBCs) leading to a significant reduction in the proportion of CD35+ RBCs during infection. Overall, severe anaemia in rhesus macaques infected with P. coatneyi has similar features to SMA in children. Our comparisons are consistent with an association of low baseline CD35 levels on RBCs and of early inflammatory responses with the pathogenesis of SMA

Lattice Dynamics and the High Pressure Equation of State of Au

Elastic constants and zone-boundary phonon frequencies of gold are calculated by total energy electronic structure methods to twofold compression. A generalized force constant model is used to interpolate throughout the Brillouin zone and evaluate moments of the phonon distribution. The moments are used to calculate the volume dependence of the Gruneisen parameter in the fcc solid. Using these results with ultrasonic and shock data, we formulate the complete free energy for solid Au. This free energy is given as a set of closed form expressions, which are valid to compressions of at least V/V_0 = 0.65 and temperatures up to melting. Beyond this density, the Hugoniot enters the solid-liquid mixed phase region. Effects of shock melting on the Hugoniot are discussed within an approximate model. We compare with proposed standards for the equation of state to pressures of ~200 GPa. Our result for the room temperature isotherm is in very good agreement with an earlier standard of Heinz and Jeanloz.Comment: 13 pages, 8 figures. Accepted by Phys. Rev.

Development and Preliminary Face and Content Validation of the "Which Health Approaches and Treatments Are You Using?" (WHAT) Questionnaires Assessing Complementary and Alternative Medicine Use in Pediatric Rheumatology

Objective Complementary and alternative medicine (CAM) is commonly used by children with juvenile idiopathic arthritis (JIA), yet no validated questionnaires assess that use. The objective of this study was to develop child self- and parent proxy-report questionnaires assessing CAM use and to determine the face and content validity of the "Which Health Approaches and Treatments are you using?" (WHAT) questionnaires in pediatric rheumatology. Methods A sequential phased mixed methods approach was used to develop the questionnaires. A Delphi Survey of 126 experts followed by an interdisciplinary consensus conference of 14 stakeholders in CAM, general pediatrics and pediatric rheumatology was held to develop consensus on the content of the questionnaires using a nominal group technique. To determine face and content validity of the questionnaires, two groups, including (a) a purposive sample of 22 children with JIA 8 to 18 years and their parents from the Children's Hospital of Eastern Ontario and the Hospital for Sick Children, and (b) 21 Canadian pediatric rheumatology experts, participated in interviews. Participants were independently asked about the goal, understandability and comprehensiveness of the WHAT questionnaires, as well as the relevance of items. Results Consensus was reached on 17 items of the WHAT questionnaires. The domains found to be relevant were child's CAM use, factors associated with CAM use, perceived impact of CAM use, and communication about CAM. A total of 15 items in the parent proxy-report questionnaire and 13 items in the child report questionnaire showed adequate content validity. Conclusions Consensus was reached by experts on the content of a pediatric CAM questionnaire. Face and content validity testing and modifications made to the WHAT questionnaires have helped ensure adequate preliminary validity for use in pediatric rheumatology. This constitutes the basis for further testing of these questionnaires in pediatric rheumatology and for adaptation to other chronic diseases

Academic, clinical and personal experiences of undergraduate healthcare students during the COVID-19 pandemic: A prospective cohort study

BackgroundCoronavirus disease 2019 has impacted upon the role and safety of healthcare workers, with the potential to have a lasting effect on their wellbeing. Limited research has been conducted during previous pandemics exploring how student healthcare workers are impacted as they study and train for their professional careers.ObjectiveThe aim of the current study was to examine the specific impact of COVID-19 on the academic, clinical and personal experiences of healthcare students.MethodUndergraduate students across three year groups within the School of Health Sciences at Ulster University completed online Qualtrics surveys at three timepoints during one academic year (2020/2021). Quantitative survey data was downloaded from Qualtrics into SPSS Version 25 for descriptive analysis of each cross-sectional sample. Qualitative survey data was downloaded into text format, which was thematically analysed using content analysis.Results412 students completed the survey at Time 1 (October 2020), n = 309 at Time 2 (December 2020) and n = 259 at Time 3 (April 2021). Academically, the pandemic had mostly a negative impact on the learning environment, the development of practical skills, the assessment process and opportunities for peer learning and support. Students reported increased stress and challenges managing their workload and maintaining a sense of motivation and routine. Clinically, they felt unprepared by the university for placement where the pandemic had an increasingly negative impact over time on learning and skill development. In terms of personal experiences, despite the majority of students taking steps to keep physically and mentally well, negative impacts on friendships, mental wellbeing and concerns for family were reported. The pandemic had not impacted upon career choice for most students.ConclusionConsideration must be given to the development of practical skills so students feel prepared for their professional careers given the practical nature of their roles. Programme coordinators should adopt a holistic approach to student wellbein

Lees and Moonshine: Remembering Richard III, 1485-1635

Published version of article deposited in accordance with Sherpa Romeo guidelines. © University of Chicago Press, 2010publication-status: AcceptedNot long after Shakespeare’s birth (1564) the last witnesses to the reign of Richard III (1483-85) would have reached the end of their lives. Richard III (c. 1592) occupies a distinctive historical moment in relation to its subject – a period after the extinction of living memory, but still within the horizon of communicative memory, the period in which stories and recollections may be transmitted across multiple generations. This essay explores how memories and “postmemories” of Richard’s reign were preserved, transmitted and transformed over the course of the sixteenth century and into the seventeenth. Whilst reflecting the powerful influence of emerging contexts including the Reformation and, ultimately, Shakespeare’s play, these memories remained distinct from and sometimes at odds with textual history. They survived because they offered their bearers a resource for interpreting and resisting the predicaments of the present, from the problem of tyranny to the legacies of the Reformation