Reactor Core Isolation Cooling Pump Performance in Multiphase Conditions

The Reactor Core Isolation Cooling (RCIC) system is found in certain boiling water reactor power plants. The RCIC system is meant to provide coolant to the reactor pressure vessel (RPV) in certain cases when the vessel is isolated from the main steam turbines and condensers. In 2011, the Great East Tohoku earthquake in Japan caused the operation of three reactors at the Fukushima Daiichi nuclear site to be interrupted. The seismic activity initiated the shutdown of the three reactors and the RCIC system came online in the two reactors equipped with a RCIC system. The RPV must have decay heat removal after shutdown. In the Fukushima Daiichi nuclear accident the RCIC system, it is believed, removed this decay heat from units 2 and 3 for 70 and 20 hours respectively. This greatly exceeds the expected RCIC run time of 4-8 hours, which is why the RCIC system has drawn great amounts of attention since the accidents. Experimental demonstration of this extended operation of the RCIC system shows that the system could be more capable of providing cooling than previously thought. As this performance in practice is far greater than the anticipated operation duration, the RCIC system merits increased study into its performance, specifically, in beyond design accidents and station blackout conditions. A Computational Multiphase Fluid Dynamics (CMFD) simulation was developed herein for implementation in STAR-CCM+. This simulation studied the RCIC pump performance and degradation due to changes in turbine performance and heat up of the Suppression Pool. As the RCIC pump and turbine are physically on the same shaft, the turbine’s performance has direct implications on the performance of the pump. One of the pump suction sources is the Suppression Pool, so a heat up of the Suppression pool could introduce two-phase flow at the pump inlet. A centrifugal pump similar to those used in RCIC Systems was created in the CMFD model to explore the pump performance as it is affected by Gas Void Fraction, and impeller rotational speed. The goal of this thesis is to develop, implement, and apply detailed mathematical models of the RCIC system pump so its performance in beyond design accident and station blackout conditions can be better understoo

High magnetic field superconducting properties of Nb3Sn films Final report

High magnetic field superconducting properties of niobium stannide films and shielding characterictics of stannide layer

Reactor Core Isolation Cooling Pump Performance in Multiphase Conditions

The Reactor Core Isolation Cooling (RCIC) system is found in certain boiling water reactor power plants. The RCIC system is meant to provide coolant to the reactor pressure vessel (RPV) in certain cases when the vessel is isolated from the main steam turbines and condensers. In 2011, the Great East Tohoku earthquake in Japan caused the operation of three reactors at the Fukushima Daiichi nuclear site to be interrupted. The seismic activity initiated the shutdown of the three reactors and the RCIC system came online in the two reactors equipped with a RCIC system. The RPV must have decay heat removal after shutdown. In the Fukushima Daiichi nuclear accident the RCIC system, it is believed, removed this decay heat from units 2 and 3 for 70 and 20 hours respectively. This greatly exceeds the expected RCIC run time of 4-8 hours, which is why the RCIC system has drawn great amounts of attention since the accidents. Experimental demonstration of this extended operation of the RCIC system shows that the system could be more capable of providing cooling than previously thought. As this performance in practice is far greater than the anticipated operation duration, the RCIC system merits increased study into its performance, specifically, in beyond design accidents and station blackout conditions. A Computational Multiphase Fluid Dynamics (CMFD) simulation was developed herein for implementation in STAR-CCM+. This simulation studied the RCIC pump performance and degradation due to changes in turbine performance and heat up of the Suppression Pool. As the RCIC pump and turbine are physically on the same shaft, the turbine’s performance has direct implications on the performance of the pump. One of the pump suction sources is the Suppression Pool, so a heat up of the Suppression pool could introduce two-phase flow at the pump inlet. A centrifugal pump similar to those used in RCIC Systems was created in the CMFD model to explore the pump performance as it is affected by Gas Void Fraction, and impeller rotational speed. The goal of this thesis is to develop, implement, and apply detailed mathematical models of the RCIC system pump so its performance in beyond design accident and station blackout conditions can be better understoo

Self-reported Needs of Youth and Families: Informing System Change and Advocacy Efforts

This study sought to explore caregiver-reported needs of youth and families receiving services within a System of Care (SOC). Data were collected to augment the in-depth, standardized interview protocols that are part of the National Evaluation of SOCs in order to identify gaps in the local delivery of services and supports to youth with severe emotional and/or behavioral disorders and their families. Primary caregivers of youth receiving services within the SOC were asked to report on the current need(s) of the youth and the current need(s) of the family. These open-ended responses were coded and examined for themes.  The most common needs of the youth were Services and Life Management, while the most common needs of the family were Services and Financial.  Focus groups conducted with youth and caregivers confirmed these themes.  Findings from this study shed light on the diverse needs of these families, indicate that families believe they are not receiving adequate supports and services, underscore that youth have distinct views, and highlight that providing a way for the typically disenfranchised youth and families to express their perspective is central to the functioning of SOCs.  Study findings were used by a local nonprofit organization to inform their advocacy efforts, and were incorporated into an enrollment process at a local mental health agency are part of a programmatic change pilot effort

Self-reported Needs of Youth and Families: Informing System Change and Advocacy Efforts

This study sought to explore caregiver-reported needs of youth and families receiving services within a System of Care (SOC). Data were collected to augment the in-depth, standardized interview protocols that are part of the National Evaluation of SOCs in order to identify gaps in the local delivery of services and supports to youth with severe emotional and/or behavioral disorders and their families. Primary caregivers of youth receiving services within the SOC were asked to report on the current need(s) of the youth and the current need(s) of the family. These open-ended responses were coded and examined for themes.  The most common needs of the youth were Services and Life Management, while the most common needs of the family were Services and Financial.  Focus groups conducted with youth and caregivers confirmed these themes.  Findings from this study shed light on the diverse needs of these families, indicate that families believe they are not receiving adequate supports and services, underscore that youth have distinct views, and highlight that providing a way for the typically disenfranchised youth and families to express their perspective is central to the functioning of SOCs.  Study findings were used by a local nonprofit organization to inform their advocacy efforts, and were incorporated into an enrollment process at a local mental health agency are part of a programmatic change pilot effort

Expansion and functional diversification of a leucyl aminopeptidase family that encodes the major protein constituents of Drosophila sperm

<p>Abstract</p> <p>Background</p> <p>The evolutionary diversification of gene families through gene creation (and loss) is a dynamic process believed to be critical to the evolution of functional novelty. Previous identification of a closely related family of eight annotated metalloprotease genes of the M17 Merops family in the <it>Drosophila </it>sperm proteome (termed, Sperm-LeucylAminoPeptidases, S-LAPs 1-8) led us to hypothesize that this gene family may have experienced such a diversification during insect evolution.</p> <p>Results</p> <p>To assess putative functional activities of S-LAPs, we (i) demonstrated that all S-LAPs are specifically expressed in the testis, (ii) confirmed their presence in sperm by two-dimensional gel electrophoresis and mass spectrometry, (iii) determined that they represent a major portion of the total protein in sperm and (iv) identified aminopeptidase enzymatic activity in sperm extracts using LAP-specific substrates. Functionally significant divergence at the canonical M17 active site indicates that the largest phylogenetic group of S-LAPs lost catalytic activity and likely acquired novel, as yet undetermined, functions in sperm prior to the expansion of the gene family.</p> <p>Conclusions</p> <p>Comparative genomic and phylogenetic analyses revealed the dramatic expansion of the S-LAP gene family during <it>Drosophila </it>evolution and copy number heterogeneity in the genomes of related insects. This finding, in conjunction with the loss of catalytic activity and potential neofunctionalization amongst some family members, extends empirical support for pervasive "revolving door" turnover in the evolution of reproductive gene family composition and function.</p

Alterations in integrin expression modulates invasion of pancreatic cancer cells

Background Factors mediating the invasion of pancreatic cancer cells through the extracellular matrix (ECM) are not fully understood. Methods In this study, sub-populations of the human pancreatic cancer cell line, MiaPaCa-2 were established which displayed differences in invasion, adhesion, anoikis, anchorage-independent growth and integrin expression. Results Clone #3 displayed higher invasion with less adhesion, while Clone #8 was less invasive with increased adhesion to ECM proteins compared to MiaPaCa-2. Clone #8 was more sensitive to anoikis than Clone #3 and MiaPaCa-2, and displayed low colony-forming efficiency in an anchorage-independent growth assay. Integrins beta 1, alpha 5 and alpha 6 were over-expressed in Clone #8. Using small interfering RNA (siRNA), integrin β1 knockdown in Clone #8 cells increased invasion through matrigel and fibronectin, increased motility, decreased adhesion and anoikis. Integrin alpha 5 and alpha 6 knockdown also resulted in increased motility, invasion through matrigel and decreased adhesion. Conclusion Our results suggest that altered expression of integrins interacting with different extracellular matrixes may play a significant role in suppressing the aggressive invasive phenotype. Analysis of these clonal populations of MiaPaCa-2 provides a model for investigations into the invasive properties of pancreatic carcinoma

Whose knowledge, whose voices? Power, agency and resistance in disability studies for the global south

Meekosha (2011) maintains that research and theories about disability derive mainly from the global North. Disability Studies rarely include non-metropolitan thinkers. Even when they do, these studies tend to be seen as context specific, and the social theories which emanate from these studies are rarely refered to in research theorizing disability in the North. This chapter sets out to investigate how this one way transfer of knowledge affects the way Disability Studies is conceptualised - whose experiences are incorporated within these studies; and whose are left out. Multilateral debate and dialogue between Disability Studies academics and activists in different locations around the world would help add on to the knowledge already available in the field, while keeping others informed about what is taking place in 'similar' situations elsewhere.peer-reviewe

Caspase Inhibition Blocks Cell Death and Enhances Mitophagy but Fails to Promote T-Cell Lymphoma

Caspase-9 is a component of the apoptosome that mediates cell death following release of cytochrome c from mitochondria. Inhibition of Caspase-9 with a dominant negative construct (Casp9DN) blocks apoptosome function, promotes viability and has been implicated in carcinogenesis. Inhibition of the apoptosome in vitro impairs mitochondrial function and promotes mitophagy. To examine whether inhibition of the apoptosome would enhance mitophagy and promote oncogenesis in vivo, transgenic mice were generated that express Casp9DN in the T cell lineage. The effects of Casp9DN on thymocyte viability, mitophagy and thymic tumor formation were examined. In primary thymocytes, Casp9DN delayed dexamethasone (Dex)-induced cell death, altered mitochondrial structure, and decreased oxidant production. Transmission electron microscopy (TEM) revealed that inhibition of the apoptosome resulted in structurally abnormal mitochondria that in some cases were engulfed by double-membrane structures resembling autophagosomes. Consistent with mitochondria being engulfed by autophagosomes (mitophagy), confocal microscopy showed colocalization of LC3-GFP and mitochondria. However, Casp9DN did not significantly accelerate T-cell lymphoma alone, or in combination with Lck-Bax38/1, or with Beclin 1+/− mice, two tumor-prone strains in which altered mitochondrial function has been implicated in promoting tumor development. In addition, heterozygous disruption of Beclin 1 had no effect on T-cell lymphoma formation in Lck-Bax38/1 mice. Further studies showed that Beclin 1 levels had no effect on Casp9DN-induced loss of mitochondrial function. These results demonstrate that neither inhibition of apoptosome function nor Beclin 1 haploinsufficiency accelerate T-cell lymphoma development in mice

Assimilation of phytate-phosphorus by the extracellular phytase activity of tobacco (Nicotiana tabacum) is affected by the availability of soluble phytate

Phytate, the major organic phosphorus in soil, is not readily available to plants as a source of phosphorus (P). It is either complexed with cations or adsorbed to various soil components. The present study was carried out to investigate the extracellular phytase activities of tobacco (Nicotiana tabacum variety GeXin No.1) and its ability to assimilate external phytate-P. Whereas phytase activities in roots, shoots and growth media of P i-fed 14-day-old seedlings were only 1.3-4.9% of total acid phosphatase (APase) activities, P starvation triggered an increase in phytase secretion up to 914.9 mU mg -1 protein, equivalent to 18.2% of total APase activities. Much of the extracellular phytase activities were found to be root-associated than root-released. The plants were not able to utilize phytate adsorbed to sand, except when insoluble phytate salts were preformed with Mg 2+ and Ca 2+ ions for supplementation. Tobacco grew better in sand supplemented with Mg-phytate salts (31.9 mg dry weight plant -1; 0.68% w/w P concentration) than that with Ca-phytate salts (9.5 mg plant -1; 0.42%), presumably due to its higher solubility. We conclude that insolubility of soil phytate is the major constrain for its assimilation. Improving solubility of soil phytate, for example, by enhancement of citrate secretion, may be a feasible approach to improve soil phytate assimilation. © Springer 2006.postprin