[EN] Power and flow oscillations in a BWR are very undesirable. One of the major concerns is to ensure, during power oscillations, compliance with GDC 10 and 12. GDC 10 requires that the reactor core be designed with appropriate margin to assure that specified acceptable fuel design limits will not be exceeded during any condition of normal operation, including the effects of anticipated operational occurrences. GDC 12 requires assurance that power oscillations which can result in conditions exceeding specified acceptable fuel design limits are either not possible or can be reliably and readily detected and suppressed. If the oscillation amplitude is large, before the scram occurs the fuel rods may experience periodic dry-out and rewetting, or if the oscillation is larger enough, extended dry-out. The Decay Ratio (DR) is the typical linear stability figure of merit. For analytical estimation of DR frequency domain codes are very useful. These types of codes are very fast and their results are very robust in comparison with time domain codes, whose results may be dependent on numeric scheme and nodalization. The only drawback of frequency domain is that you are limited to the linear domain; however, because of regulatory requirements imposed by GDC-12, reactors must remain stable and, thus, reactors always operate in the linear domain. LAPUR is a frequency domain stability code that contains a mathematical description of the core of a boiling water reactor. It solves the steady state governing equations for the coolant and fuel, and the dynamic equations for the coolant, fuel and the neutron field in the frequency domain. Several improvements have been performed to the current version of the code, LAPUR5, in order to upgrade it for use with new fuel design types. The channel geometry has been changed from constant area to variable area. The local losses due to the spacers and contractions along the flow path have been upgraded to use industry standard correlations. This new version is LAPUR 6. In this work, in order to check the correct implementation of these changes, a two-fold LAPUR 6 validation has been performed: First, an exhaustive validation of the models implemented has been performed, comparing single channels LAPUR 6 outputs against SIMULATE-3 results. Cofrentes NPP SIMULATE-3 thermal-hydraulic models have been independently validated against experimental data. Second, a Methodology for calculating Decay Ratios with LAPUR 6 has been developed, defining a validation matrix against analytical and plant measured decay ratios. Analysis of measured data from the Cofrentes NPP has shown that decay ratios have values lower than 0.3 confirming the large stability margin of Cofrentes NPP when proper operating procedures are followed, and the comparison with LAPUR shows deviations less than +/- 0.1. Past experience suggests that the uncertainty in low decay ratio ranges is usually larger than with higher decay ratio values. Finally a BWR noise generator has been used for estimating the uncertainty of the signal analyses methods used in this work for experimental estimation of decay ratio from the autocorrelation function of the APRM or LPRM power signals. / [ES] Las oscilaciones de potencia y caudal en un BWR no son deseables. Una de las principales preocupaciones es asegurar, durante oscilaciones de potencia, el cumplimiento de la GDC 10 y 12. GDC 10 requiere que el núcleo del reactor se haya diseñado con un margen adecuado para asegurar que los límites admisibles establecidos en el diseño del combustible no se excederán en cualquier condición de operación normal, incluyendo los efectos de los sucesos operacionales anticipados. GDC 12 requiere garantías de que las oscilaciones de potencia que pueden resultar en condiciones que excedan los límites admisibles establecidos de diseño del combustible, o bien no son posibles o puedan ser detectadas y suprimidas de forma pronta y segura. Si la amplitud de la oscilación es grande, antes de que se produzca el scram las varillas de combustible pueden experimentar secados y remojados periódicos, o si las oscilaciones son suficientemente grandes, un secado extendido. La tasa de amortiguamiento (DR) es la típica figura de mérito de la estabilidad lineal. Para la estimación analítica de la DR los códigos en el dominio de la frecuencia son muy usados. Este tipo de códigos son muy rápidos y sus resultados son muy robustos en comparación con los códigos en el domino temporal, cuyos resultados pueden depender del esquema numérico y la nodalización. El único inconveniente de los códigos en el dominio de la frecuencia es que está limitado al dominio lineal; sin embargo, como los requerimientos regulatorios impuestos por el GDC-12, los reactores deben permanecer estables y, por lo tanto, los reactores deben operar siempre en el dominio lineal. LAPUR es un código de estabilidad en el dominio de la frecuencia que contiene una descripción matemática del núcleo de un reactor de agua en ebullición. Resuelve las ecuaciones de conservación en estado estacionario para el refrigerante y el combustible, las ecuaciones dinámicas para el refrigerante, el combustible y el campo neutrónico en el dominio de la frecuencia. Se han realizado varias mejoras a la versión actual del código, LAPUR 5, con el fin de actualizarlo para su uso con los nuevos tipos de diseño de combustible. La geometría del canal se ha cambiado, el área ha pasado de ser constante a poder considerar área variable. El cálculo de las pérdidas locales debido a los espaciadores y contracciones a lo largo del camino que sigue el flujo se han actualizado, pasando a utilizar correlaciones estándar de la industria. Esta nueva versión del código se ha denominado LAPUR 6. En este trabajo, con el fin de verificar la correcta implementación de estos cambios, se ha realizado una doble validación del código LAPUR 6: En primer lugar se ha realizado una validación exhaustiva de los modelos implementados, comparando los valores de salida de LAPUR 6 para un canal con los resultados de SIMULATE-3. Los modelos termohidráulicos de la CN Cofrentes de SIMULATE-3 han sido validados de forma independiente con los datos experimentales. En segundo lugar se ha desarrollado una metodología para el cálculo de la tasa de amortiguamiento con LAPUR 6, definiendo una matriz de validación de los valores de tasa de amortiguamiento analíticos con valores medidos en la planta. Las tasas de amortiguamiento medidos en la Central Nuclear de Cofrentes tienen valores inferiores al 0.3, confirmando el gran margen de estabilidad de la Central Nuclear de Cofrentes cuando se siguen los procedimiento de operación adecuados, y la comparación con los resultados de LAPUR muestra desviaciones de menos de +/- 0.1. La experiencia acumulada sugiere que la incertidumbre para los rangos bajos de tasas de amortiguamiento es generalmente más grande que para los valores altos. Por último se ha utilizado un generador de señales BWR para la estimación de la incertidumbre de los métodos de análisis de señales utilizados en este trabajo para la estimación experimental de la DR, a partir de la funci / [CAT] Les oscil·lacions de potència i flux en un BWR són molt poc desitjades. Una de les majors preocupacions és assegurar-se, durant les oscil·lacions de potència, del compliment de GDC 10 i 12. GDC 10 requerix que el nucli del reactor estiga dissenyat amb un marge apropiat per a assegurar que els limits admissibles establerts en el disseny del combustible no siguen superats davall cap condició d'operació normal, incloent els incidents esperats d'operació. GDC 12 requerix assegurar que les oscil·lacions de potència que poden resultar en condicions on es superen els limits admissibles establerts en el disseny del combustible no siguen possibles o puguen ser detectades de manera segura e immediata i suprimides. Si l'amplitud de les oscil·lacions és gran, abans que el scram ocórrega les barres experimenten un assecat i remullat periòdic, o si l'oscil·lació és prou gran, un assecat estés. La taxa d'amortiment (DR) és la típica figura de mèrit de l'estabilitat lineal. Per a l'estimació analítica de la DR són molt usats els codis en el domini de la freqüència. Este tipus de codis són molt ràpids i els seus resultats són molt robustos en comparació amb els codis en el domini temporal, els resultats del qual són molt dependents de l'esquema numèric i la nodalizació. L'únic inconvenient del domini de la freqüència és que està limitat al domini lineal, no obstant això, com els requeriments reguladors imposats pel GDC-12, els reactors han de mantener-se estables i, per tant, els reactors han d'operar sempre en el domini lineal. LAPUR és un codi d'estabilitat en el domini de la freqüència que conté una descripció matemàtica del nucli d'un reactor d'aigua en ebullició. Resol les equacions de govern estacionàries del refrigerant i el combustible, les equacions dinàmiques del refrigerant, el combustible i el camp neutrònic en el domini de la freqüència. S'han realitzat diverses millores a la versió anterior del codi, LAPUR 5, amb l'objectiu d'actualitzar-ho per al seu ús amb nous tipus de disseny de combustibles. La geometria del canal s'ha canviat d'àrea constant a variable. Les pèrdues locals degudes als espaciadors i contraccions al llarg del camí del flux s'han actualitzat per a utilitzar correlacions estàndard de la indústria. Esta nova versió és LAPUR 6. En este treball, amb l'objectiu de comprovar la correcta implementació d'estos canvis, s'ha realitzat una doble validació del LAPUR 6: Primer, s'ha realitzat una validació exhaustiva dels models implementats, comparant els valors d'eixida per a un canal de LAPUR 6 amb els resultats de SIMULATE-3. Els models termohidraúlics per a SIMULATE-3 de la Central Nuclear de Cofrentes s'han validat independentment amb dades experimentals. Segon, s'ha desenrotllat una Metodologia per al càlcul de la Taxa d'Amortiment amb LAPUR 6, definint una matriu de validació amb valors de taxes d'amortiment analítics i mesurats en la planta. Anàlisis de les dades mesurades en la Central Nuclear de Cofrentes mostren valors de les taxes d'amortiment inferiors al 0.3, confirmant el gran marge d'estabilitat de la Central Nuclear de Cofrentes quan se seguix un adequat procediment d'operació, i la comparació amb LAPUR mostra desviacions inferiors al +/- 0.1. L'experiència acumulada mostra que la incertesa en el rang de taxes d'amortiment baixes és normalment major que per a valors alts de les taxes d'amortiment. Finalment s'ha utilitzat un generador de senyals per a estimar la incertesa dels mètodes d'anàlisi del senyal utilitzats en este treball per a l'estimació experimental de la taxa d'amortiment emprant la funció d'autocorrelació dels senyals de potència APRM o LPRM. / Melara San Román, J. (2016). PREDICTIVE METHODS FOR STABILITY MARGIN IN BWR [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/61307 / TESIS

Thesis: B.S., Massachusetts Institute of Technology, Department of Mechanical Engineering, 1976 / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Includes bibliographical references. / B.S. / B.S. Massachusetts Institute of Technology, Department of Mechanical Engineering

<p>The sex ratio at birth in China has been increasingly skewed in favor of males since 1980 when the government implemented the one-child policy to control population growth. Existing studies commonly point to economic factors and their weakening effect on the Confucian tradition of son preference to understand the male-biased sex ratio at birth; however, a perspective that heavily focuses on economic factors is limited. In this dissertation, I argue that bringing in religion – a key factor shaping individual attitudes and decisions related to son preference – can shed important light upon sex ratio at birth patterns in China.</p><p>This dissertation is divided into three empirical chapters. The first study explores religious effects on county-level sex ratios at birth using data from the 2000 China Population Census and the 2004 China Economic Census. Findings reveal that greater Daoist presence is associated with more imbalanced sex ratios in the county, while the presence of Islamic and Buddhist places of worship helps mitigate male-biased sex ratios. Study two askes how religious groups vary in their preferences for sons and sex selection decisions using data from the 2010 Chinese General Social Survey (CGSS). Findings suggest that Christians stand out for their weak son preference and refrain from sex selection, while Daoists hold strong son preference and more likely to practice sex selection to have many sons. The last study uses the CGSS data to explore whether religion shapes abortion attitudes among Chinese people. It shows that Islam and Christianity have a strong influence on the disapproval of abortion, and while affiliating with Daoism does not affect one’s approval of abortion, living in a neighborhood with more Daoists significantly reduces one’s approval of abortion.</p><div><p>These studies together demonstrate that religion is an important factor shaping not only individual attitudes and behaviors but also demographic trends in society. This dissertation serves as the first study that investigates the linkage between religion and demographic trends by examining how religion – both individual religious affiliation and religious context in a locality – affects the sex ratio at birth via shaping individual son preferences, sex selection decisions, and abortion attitudes. By highlighting religion – a factor that has been overlooked in demographic studies of China – this study contributes to a more nuanced understanding of imbalanced sex ratios and its determinants.</p></div><p></p>

Current forensic DNA analysis utilizes capillary electrophoresis (CE) to separate short tandem repeat (STR) fragments based on their length. Next generation sequencing (NGS) is the next evolution of forensic DNA profiling, and though dedicated forensics protocols are still fairly new, it is only a matter of time before NGS becomes the new standard for forensic DNA profiling. Stutter has been a problem ever since forensic STR testing was first implemented. The slipped strand mispairing model is the proposed mechanism for how stutter occurs, and it appears to be an intrinsic part of the polymerase chain reaction (PCR). Samples that were run via the ForenSeq™ DNA Signature Prep Kit were amplified using the DNA Primer Mix A (DPMA) and then sequenced on a MiSeq FGx™ Forensics Genomics System. Samples were also amplified using the GlobalFiler™ PCR Amplification kit and fragment separation was done via capillary electrophoresis. Stutter ratios were calculated by dividing the read count /relative fluorescence unit of the stutter allele by the read count / relative fluorescence unit of the parent allele. Stutter ratio comparisons were made between the ForenSeq™ and GlobalFiler™ kits as well as between the parents and the children in the family pedigree, though only samples tested using the ForenSeq™ kit were used. Comparison of overall stutter ratios revealed that the ForenSeq™ kit produced higher stutter across all STR loci, except for D13S317 and D2S441, when compared to the GlobalFiler™ kit. The different chemistries between the two kits, potential usage of different polymerases, and the fact that the ForenSeq™ kit requires two rounds of amplification can serve as likely explanations for this difference. There was also quite a bit of variability observed for the stutter ratios between loci in the samples run using the ForenSeq™ kit. Possible explanations for this could be that the cluster generation step could produce more clusters for some stutter products over others. Comparison of the stutter ratios for the pedigree obtained from the Coriell Institute revealed no differences between the parents and the respective alleles inherited by the children when tested with the ForenSeq™ kit. Some loci showed a difference between the parent and children, but that could simply be due to the sample size. The utilization of NGS for STR testing can result in two alleles of the same length but different sequences, called isoalleles. Analysis of isoalleles present at D21S11 in the children samples from the Coriell Institute pedigree showed that the isoalleles had different mean stutter ratios. The results open the possibility of potentially utilizing sequence-specific stutter filters in the ForenSeq™ Universal Analysis Software. The model of the longest uninterrupted stretch (LUS) has been around for some time, though recently the block length of missing motif (BLMM) has been proposed as a better predictor for stutter ratios. The results of stutter ratio analysis at D21S11 show that as the length of the BLMM increases, so too does the stutter ratio.

Revenue insurance with shallow loss protection for farmers has been introduced recently. A common attribute of most shallow loss proposals is that they would be arearevenue triggered. The impact on optimal hedge ratios of combining these shallow loss insurance proposals with deep loss farm-level insurance is examined. Since crop insurance, commodity programs and forward pricing are commonly used concurrently to manage crop revenue risk, the optimal combinations of these tools are explored. Numerical analysis in the presence of yield, basis and futures price variability is used to find the futures hedge ratio which maximizes the certainty equivalent of a risk averse producer. The results generally reveal a lower optimal hedge ratio with area-insurance than with individual insurance and show that shallow loss revenue insurance tends to slightly increase optimal hedge ratios.

<p> The primary purpose of this study was to date the last metamorphism of a metanorthosite near Parry Sound, Ontario, by the Rb-Sr method on the mineral phases: biotite, hornblende and plagioclase. Due to problems with the mass spectrometer, the prepared samples could not be run. </p> <p> K/Rb ratios on biotites and plagioclase give a calculated K/Rb whole rock ratio for the mafic rich bands of about 230, consistent with the main trend of igneous rocks. The plagioclase K/Rb ratio, however, is much higher, and the anorthosite body as a whole may have a much higher K/Rb ratio, consistent with oceanic tholeiites and achondritic meteorites and indicating a possible lower crustal or mantle origin. </p> / Thesis / Bachelor of Science (BSc)

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