Optimal Burnable Absorber Assignment for PWR Core Reload Design

A new method has been developed to assign burnable poison loadings in the optimization of Pressurized Water Reactor core reload design. The method utilizes successive linear programming to determine the desired burnable poison loading. The optimum loading is selected after the evaluation of all candidate loadings close to the desired loading. The design method was implemented as a sub-program in the nodal core analysis code SIMULATE. The technique was applied to re-design Commonwealth Edison\u27s Zion Unit-1 cycles 9 and 10. Significant improvements were achieved in cycle length, number of BP rods required, and power peaking. The present work completely automates the core reload design problem, significantly decreasing the time and effort required of the designer

Unifying disparate experimental views on shear-thickening suspensions

Shear thickening denotes the rapid and reversible increase in viscosity of a suspension of rigid particles under external shear. This ubiquitous phenomenon has been documented in a broad variety of multiphase particulate systems, while its microscopic origin has been successively attributed to hydrodynamic interactions and frictional contact between particles. The relative contribution of these two phenomena to the magnitude of shear thickening is still highly debated and we report here a discriminating experimental study using a model shear-thickening suspension that allows us to tune independently both the surface chemistry and the surface roughness of the particles. We show here that both properties matter when it comes to continuous shear thickening (CST) and that the presence of hydrogen bonds between the particles is essential to achieve discontinuous shear thickening (DST) by enhancing solid friction between closely contacting particles. Moreover, a simple argument allows us to predict the onset of CST, which for these highly-textured particles occurs at a critical volume fraction much lower than that previously reported in the literature. Finally, we demonstrate how mixtures of particles with opposing surface chemistry make it possible to finely tune the shear-thickening response of the suspension at a fixed volume fraction, paving the way for a fine control of shear-thickening transition in engineering applications.Comment: 8 pages, 5 figure

HEALTH LEGACY FOUNDATIONS AND THE PURSUIT OF CHARITABLE HEALTHCARE

Endowed with proceeds from transactions involving nonprofit healthcare assets, health legacy foundations (HLFs) embody tremendous potential to improve health and healthcare in communities across the nation. This dissertation represents the culmination of a systematic search for HLFs, provides community-level analyses of needs where HLFs are established, and describes how HLFs articulate their intent to pursue a charitable health purpose. The first phase of this research entailed the development of a new, comprehensive database of HLFs, which includes 306 foundations in forty-three states; aggregate HLF assets in 2010 totaled more than $26 billion. The next phase of this study examined health determinants in communities where HLFs have been formed from the sale of local nonprofit hospitals. Compared to non-HLF counties, HLF counties had significantly higher proportions of racial minorities and multiple socioeconomic indicators that render them more vulnerable to health disparities and poor health. The final phase of this research explored the charitable health intent of HLFs formed from hospitals as revealed through their self-defined missions. Although the majority of HLFs adopted an explicit health-related purpose, most depicted health in vague terms. Broadly construed mission statements allow grantmakers the freedom to choose the combination of services and beneficiaries that maximizes utility for their communities. While this flexibility is important for HLFs to address broad health determinants and respond to changing community needs, careful public oversight is critical to ensure that nonprofit healthcare proceeds are strategically redeployed

A comparison between Asian and Australasia backpackers using cultural consensus analysis

This study tests the differences in the shared understanding of the backpacker cultural domain between two groups: backpackers from Australasia and backpackers from Asian countries. A total of 256 backpackers responded to a questionnaire administered in Kuala Lumpur, Bangkok and Krabi Province (Thailand). Cultural consensus analysis (CCA) guided the data analysis, to identify the shared values and the differences in the backpacker culture of the two groups. The findings revealed that while the two groups share some of the backpacker cultural values, some other values are distinctively different from one another. The study provides the first empirical evidence of the differences in backpacking culture between the two groups using CCA. Based on the study findings, we propose some marketing and managerial implications

Results of WICOVIR Gargle Pool PCR Testing in German Schools Based on the First 100,000 Tests

Background: Opening schools and keeping children safe from SARS-CoV-2 infections at the same time is urgently needed to protect children from direct and indirect consequences of the COVID-19 pandemic. To achieve this goal, a safe, efficient, and cost-effective SARS-CoV-2 testing system for schools in addition to standard hygiene measures is necessary. Methods: We implemented the screening WICOVIR concept for schools in the southeast of Germany, which is based on gargling at home, pooling of samples in schools, and assessment of SARS-CoV-2 by pool rRT-PCR, performed decentralized in numerous participating laboratories. Depooling was performed if pools were positive, and results were transmitted with software specifically developed for the project within a day. Here, we report the results after the first 13 weeks in the project. Findings: We developed and implemented the proof-of-concept test system within a pilot phase of 7 weeks based on almost 17,000 participants. After 6 weeks in the main phase of the project, we performed >100,000 tests in total, analyzed in 7,896 pools, identifying 19 cases in >100 participating schools. On average, positive children showed an individual CT value of 31 when identified in the pools. Up to 30 samples were pooled (mean 13) in general, based on school classes and attached school staff. All three participating laboratories detected positive samples reliably with their previously established rRT-PCR standard protocols. When self-administered antigen tests were performed concomitantly in positive cases, only one of these eight tests was positive, and when antigen tests performed after positive pool rRT-PCR results were already known were included, 3 out of 11 truly positive tests were also identified by antigen testing. After 3 weeks of repetitive WICOVIR testing twice weekly, the detection rate of positive children in that cohort decreased significantly from 0.042 to 0.012 (p = 0.008). Interpretation: Repeated gargle pool rRT-PCR testing can be implemented quickly in schools. It is an effective, valid, and well-received test system for schools, superior to antigen tests in sensitivity, acceptance, and costs

Health legacy foundations and the pursuit of charitable healthcare

Endowed with proceeds from transactions involving nonprofit healthcare assets, health legacy foundations (HLFs) embody tremendous potential to improve health and healthcare in communities across the nation. This dissertation represents the culmination of a systematic search for HLFs, provides community-level analyses of needs where HLFs are established, and describes how HLFs articulate their intent to pursue a charitable health purpose. The first phase of this research entailed the development of a new, comprehensive database of HLFs, which includes 306 foundations in forty-three states; aggregate HLF assets in 2010 totaled more than $26 billion. The next phase of this study examined health determinants in communities where HLFs have been formed from the sale of local nonprofit hospitals. Compared to non-HLF counties, HLF counties had significantly higher proportions of racial minorities and multiple socioeconomic indicators that render them more vulnerable to health disparities and poor health. The final phase of this research explored the charitable health intent of HLFs formed from hospitals as revealed through their self-defined missions. Although the majority of HLFs adopted an explicit health-related purpose, most depicted health in vague terms. Broadly construed mission statements allow grantmakers the freedom to choose the combination of services and beneficiaries that maximizes utility for their communities. While this flexibility is important for HLFs to address broad health determinants and respond to changing community needs, careful public oversight is critical to ensure that nonprofit healthcare proceeds are strategically redeployed

Trente ans de relance pastorale en Ariège : le temps de la maturité. Les enseignements de l'enquête pastorale de 1999 et du recensement agricole de 2000

Thirty years of pastoral revival in Ariège : the time for maturity. the finds of the 1999 pastoral enquiry and of the 2000 agricultural census. The results of the 1999 pastoral enquiry and of the 2000 agricultural census question the classical picture of an archaic and old-fashioned agriculture in the Pyrénées, with low technical yields. The analysis of the census, for the whole of the massif to begin with, then more precisely concerning Ariège, sets in light the spectacular modernization of mountain agriculture, which has become strongly specialized and rejuvenated, at the cost however of the disappearance of a very large number of farms. Together with reorganizing their structures, the breeders took up again the mountain pastures in hand ; they knew how to organize themselves and their « mountains », with the help of various support programmes deriving from the 1972 pastoral law.Les résultats de l'enquête pastorale de 1 999 et du recensement agricole de 2000 permettent de remettre en cause l'image classique d'une agriculture pyrénéenne vieillie et archaïque, aux performances techniques médiocres. L'analyse de ces deux recensements, sur l'ensemble du massif dans un premier temps, puis plus précisément en Ariège, met en évidence la spectaculaire modernisation de l'agriculture de montagne, qui s'est profondément rajeunie et spécialisée, au prix cependant de la disparition d'un très grand nombre d'exploitations. Cette restructuration s'est accompagnée d'une véritable reprise en main des estives par des éleveurs qui ont su à la fois s'organiser et aménager leurs « montagnes », avec l'appui des différents programmes de soutien initiés par les lois pastorales de 1972.Treinta anos de resurgimiento del pastoralismo en el departamento del Ariège : época de madurez. las enseñanzas de la encuesta ganadera de 1999 y del censo agrícola de 2000. Los resultados de la encuesta ganadera de 1999 y del censo agrícola de 2000 permiten cuestionar la imagen clásica de una agricultura anticuada y arcaica, con rendimientos técnicos mediocres. El análisis de ambos censos, sobre la totalidad de los Pirineos en un primer tiempo, luego más precisamente en Ariège, evidencia la espectacular modernización de la agricultura de montaña, que ha rejuvenecido y se ha especializado, originando sin embargo la desaparición de un gran número de explotaciones. Con esta restructuración se efectúa una verdadera recuperación de los puertos estivales por los ganaderos que han sabido a la vez organizarse y organizar sus « montañas », con la ayuda de los diferentes programas de apoyo iniciados por las leyes ganaderas de 1972.Eychenne-Niggel Corinne. Trente ans de relance pastorale en Ariège : le temps de la maturité. Les enseignements de l'enquête pastorale de 1999 et du recensement agricole de 2000. In: Sud-Ouest européen, tome 16, 2003. Pastoralisme et environnement (Coordonné par Jean-Paul Métailié) sous la direction de Jean-Paul Métailié. pp. 5-13