Heat and mass transfer analysis for crud coated PWR fuel

In water-cooled nuclear reactors, various species are present in the coolant, either in ionic solution, or entrained as very fine particles. Most arise from corrosion of primary circuit surfaces, or from chemicals, such as boric acid, lithium hydroxide, zinc and hydrogen, deliberately added to the coolant. These materials deposit on the surfaces of fuel pins, typically in the upper regions of the core, forming what is generally termed “crud”. This thesis reports a study of the thermal-hydraulic consequences of this deposit. These crud deposits are generally found to contain a large population of through-thickness chimneys, and it is believed that this gives rise to a wick-boiling mechanism of heat transfer. A coupled two-dimensional model of the processes of heat conduction, advection and species diffusion in the crud has been developed. An iterative scheme has been employed to solve the set of coupled equations of each process. The wick boiling process has been found to be an efficient heat transfer mode, taking away about 80% of the heat generated. It has also been found that consideration of heat transfer in the clad can increase the predicted solute concentration in the crud. The effects of some important parameters, such as chimney density, chimney radius, porosity of the crud, crud thickness, clad heat flux and boron concentration in the coolant have been investigated. The fuel thermal performance has been characterized in terms of an effective crud thermal conductivity, and the non-linear dependence this has on parameters such as crud thickness and chimney density had been determined. Lastly, it is observed that plausible pore sizes of the crud, coupled with higher temperatures in the crud, may be such that a film of vapour is generated at the base of the crud. Initial estimates are presented of the cladding temperatures and solute concentration that may be generated as a consequence of this vapour layer

Pakistan’da hadis tartışmaları

06.03.2018 tarihli ve 30352 sayılı Resmi Gazetede yayımlanan “Yükseköğretim Kanunu İle Bazı Kanun Ve Kanun Hükmünde Kararnamelerde Değişiklik Yapılması Hakkında Kanun” ile 18.06.2018 tarihli “Lisansüstü Tezlerin Elektronik Ortamda Toplanması, Düzenlenmesi ve Erişime Açılmasına İlişkin Yönerge” gereğince tam metin erişime açılmıştır.Semavî dinlerin temel gayesi insan ve cin olmak üzere mükellef olan mahlûkata Allah'ın isteğine uyumlu hayat düzeni sunarak, onlara dünya ve ahirette başarılı olabilme imkânı sağlamaktır. Mezkûr esastan hareketle karşımıza çıkan ilk soru dinin nereden öğrenileceğidir. Bu sorunun cevabı olarak bütün semâvî dinler esas olarak peygamberi referans göstermiştir. Fakat peygamberin kendisine indirilen vahye (kitaba) getirdiği açıklamalar ile diğer davranışlarının dindeki yeri ve bağlayıcılığı gibi önemli konular üzerinde farklı tartışmalar gerçekleşmiştir. Bu çalışmada bahsi geçen konunun farklı yönleriyle ilgili Pakistan'daki düşünürlerin görüşleri incelenmiştir. Çalışma, giriş, dört bölüm ve sonuçtan oluşmaktadır. Giriş kısmında tezin konusu ve önemi, araştırmanın amacı ve yöntemiyle birlikte bazı kaynaklar hakkında bilgi verilmiştir. Birinci bölüm Hz. Peygamber'in otoritesiyle alakalıdır. Bu bölümde Hz. Peygamber'e Kur'ân dışında vahiy verilip verilmeme meselesi ele alınmıştır. Daha sonra ise Hz. Peygamber'in otoritesinin mahiyeti, yani onun davranışlarının bağlayıcılığının sınırları hakkındaki görüş farklılıkları üzerinde durulmuştur. İkinci bölüm Hz. Peygamber'e nispet edilen söz, fiil ve takrirlerinin (hadis/sünnet) dindeki yerine ilişkindir. Bu bölümde hadis/sünnet kavramı, hücciyeti, Kur'ân'la olan ilişkisi, bunların tespit ölçütleri ve anlama esasları hakkındaki tartışmalardan bahsedilmiştir. Üçüncü bölümde, hadis tarihi ve usulü hakkındaki tartışmalar işlenmiştir. Burada hadis rivâyetinin ne zaman ve neden başladığı, hadislerin yazılması ve tedvini hakkındaki bazı hususlar, hadis uydurma hareketlerinin başlangıcı ve bunun kimi sebeplerinden bahsedilirmiştir. Ayrıca hadisçiler tarafından, hadis ve sünnetin tespiti için ortaya konulan usuller üzerindeki tartışmalar zikredilmiştir. Dördünce bölümde ise önceki bölümlerde zikredilen farklı görüşlerden hareketle bazı hadisler hakkında metin açısından cereyan eden tartışmalar ele alınmıştır. Nihayet tez sonuç kısmıyla tamamlanmıştır.The heavenly religions aim to provide believers the code of life in harmony with Allah's will and to enable them to succeed in the world and the hereafter. The first question that arises from the aforementioned principle is from where to learn the religion. As an answer to this question, all revelation-based religions mainly referred to their respective prophets. Contrary to this, there were different debates on important issues such as the significance of Prophet's explanations, teachings and deeds in relation to his revelations (Book). This study examines the different aspects of opinions of Pakistani scholars about the above mentioned issues. The study consists of introduction, four chapters and conclusion. The introductory part includes significance, objectives and research methodology of the study. The first chapter is about the authority of the Prophet Muhammad (PBUH). It discusses the issue of whether or not revelation excluding the Holy Qur'an was revealed to him (PBUH). Different opinions about the nature of the authority of the Prophet (PBUH) and the boundaries of the binding of his behaviour are also emphasized. The second chapter discusses the difference of opinions about the terms of hadith and sunnah, its authority and authenticity, its relationship with the Holy Qur'an. Their determined criteria and principles of understanding are also discussed. The third chapter discusses the history of hadith, its process of narration, compilation, beginning of the hadith fabrication movements and their reasons. In addition, the discussions about the methods put forward by muhaddithin to examine the authenticity hadiths also are mentioned. The fourth chapter includes discussions on some specific hadiths from textual aspect which have been considered unauthentic or fabricated. The final part is based upon conclusions of the thesis

Two dual-function regulatory sRNAs in Bacillus subtilis, and their role in RNA degradation and sporulation

This study was conducted to identify a new function of the trans-encoded sRNA SR1 and to characterize a small protein encoded by the new potential dual-function sRNA SR7 in the Gram-positive model organism B. subtilis. The small RNA SR1 was found to inhibit translation of kinA mRNA. Neither the SR1 encoded peptide SR1P plays any role in the regulation of kinA nor SR1 influences the stability of kinA mRNA. The role of SR1 in sporulation was confirmed by analysing its effects on the promoters of downstream genes controlled by KinA through Spo0A. No role of Hfq or CsrA in sporulation was observed. SR1 was found to decelerate sporulation when glucose is exhausted. Moreover, SR1 impacted spore properties. Spores formed in the absence of SR1 exhibited lower resistance to stress conditions and displayed an altered composition of spore coat proteins. The sr7 gene was tagged in its native locus with a C-terminal 3x FLAG tag and the synthesis of the small protein SR7P confirmed in Western blots. Threefold increased amounts of SR7P were produced under different stress conditions. In co-elution experiments the glycolytic enzyme enolase was identified as interaction partner for SR7P. The binding of SR7P to enolase in turn improved the binding of enolase to RNase Y present in the DLN of B. subtilis. By contrast, it had no effect on the interaction of enolase with PfkA also present in the DLN. Enolase carries ten times more RNase Y in the presence of SR7P. RNA is not bridging the interaction between SR7P and enolase. SR7P does not directly bind RNase Y. In vitro RNase Y activity assays revealed a role of SR7P in modulation of the activity of Eno-bound RNase Y. The role of SR7P in modulation of the activity of Eno-bound RNase Y was confirmed in vivo for rpsO mRNA. Taken together, both small RNAs SR1 and SR7 are involved in the regulation of sporulation and modulation of DLN in B. subtilis under glucose limiting and stress conditions

Moonlighting in Bacillus subtilis: The Small Proteins SR1P and SR7P Regulate the Moonlighting Activity of Glyceraldehyde 3-Phosphate Dehydrogenase A (GapA) and Enolase in RNA Degradation

Moonlighting proteins are proteins with more than one function. During the past 25 years, they have been found to be rather widespread in bacteria. In Bacillus subtilis, moonlighting has been disclosed to occur via DNA, protein or RNA binding or protein phosphorylation. In addition, two metabolic enzymes, enolase and phosphofructokinase, were localized in the degradosome-like network (DLN) where they were thought to be scaffolding components. The DLN comprises the major endoribonuclease RNase Y, 30 -50 exoribonuclease PnpA, endo/50 -30 exoribonucleases J1/J2 and helicase CshA. We have ascertained that the metabolic enzyme GapA is an additional component of the DLN. In addition, we identified two small proteins that bind scaffolding components of the degradosome: SR1P encoded by the dual-function sRNA SR1 binds GapA, promotes the GapARNase J1 interaction and increases the RNase J1 activity. SR7P encoded by the dual-function antisense RNA SR7 binds to enolase thereby enhancing the enzymatic activity of enolase bound RNase Y. We discuss the role of small proteins in modulating the activity of two moonlighting proteins

The role of job stress and phychological capital on the relationship between interpersonal mistreatment and individual job outcomes

Detrimental effects of interpersonal mistreatments at workplace have drawn unprecedented attention of researchers over the last couple of decades. This research is an attempt to fulfill the gap by examining western theories of interpersonal mistreatments in non-western settings. This research examined major (sexual harassment and workplace ostracism) and minor (workplace incivility) interpersonal mistreatments categories together with the underlying mechanism and consequences. Besides that, the mediated role of job stress with interpersonal mistreatments and their job outcomes (job burnout and turnover intention) was also studied. In addition, this research studied the coping mechanism of job stress by examining psychological capital as a moderator in relationship between job stress and job outcomes. A three wave study design was employed in the research. Multistage sampling technique was applied whereby the respondents were 1850 employees from the telecom sector in Pakistan. In the final wave, 523 responses from the same respondents were used in the analysis. Correlation, regression and structural equation modeling were used for data analysis. Findings suggested that interpersonal mistreatments were positively related to job stress, job burnout and turnover intentions. Job stress has been shown to partially mediate between interpersonal mistreatments and job outcomes. Moreover, results suggested that the relationship between job stress and job burnout was weakened when psychological capital was high. Similarly, the relationship between job stress and employee turnover intention weakened when psychological capital was high. This research generalizes the findings of western theories on interpersonal mistreatments in the non-western culture (Pakistan) and suggests that psychological capital be applied as a strong personal resource to cope with workplace stressors and stress related job outcomes

Intermolecular Communication in Bacillus subtilis: RNA-RNA, RNA-Protein and Small Protein-Protein Interactions

In bacterial cells we find a variety of interacting macromolecules, among them RNAs and proteins. Not only small regulatory RNAs (sRNAs), but also small proteins have been increasingly recognized as regulators of bacterial gene expression. An average bacterial genome encodes between 200 and 300 sRNAs, but an unknown number of small proteins. sRNAs can be cis - or trans -encoded. Whereas cis -encoded sRNAs interact only with their single completely complementary mRNA target transcribed from the opposite DNA strand, trans -encoded sRNAs are only partially complementary to their numerous mRNA targets, resulting in huge regulatory networks. In addition to sRNAs, uncharged tRNAs can interact with mRNAs in T-box attenuation mechanisms. For a number of sRNA-mRNA interactions, the stability of sRNAs or translatability of mRNAs, RNA chaperones are required. In Gram-negative bacteria, the well-studied abundant RNA-chaperone Hfq fulfils this role, and recently another chaperone, ProQ, has been discovered and analyzed in this respect. By contrast, evidence for RNA chaperones or their role in Gram-positive bacteria is still scarce, but CsrA might be such a candidate. Other RNA-protein interactions involve tmRNA/SmpB, 6S RNA/RNA polymerase, the dual-function aconitase and protein-bound transcriptional terminators and antiterminators. Furthermore, small proteins, often missed in genome annotations and long ignored as potential regulators, can interact with individual regulatory proteins, large protein complexes, RNA or the membrane. Here, we review recent advances on biological role and regulatory principles of the currently known sRNA-mRNA interactions, sRNA-protein interactions and small protein-protein interactions in the Gram-positive model organism Bacillus subtilis . We do not discuss RNases, ribosomal proteins, RNA helicases or riboswitches

Masculinidades: Rastreando las Trayectorias de Género en la Poesía de Guerra

This paper critically examines the war songs and poems of men who fought in the post 9/11 Afghanistan war. The study locates the analysis within the socio-cultural influences that left an impact on the ‘manly’ soldiers, allowing a 'micro mapping' of masculinity to be revealed in these men’s writings. Using thematic analysis techniques, fifty war songs and poemsfrom the years 2007 and 2008 are analyzed through the lens of masculinity and its performance. The critical investigation of the war songs and poems found that the performative dimension of masculinities in war spread around the themes of youth warriors; weapons; arms and war machinery; state of politics and need for an Islamic government; the motif of red color; and glorification of death. The religion Islam, their homeland Afghanistan and its traditional culture constantly act as a fuel to evoke overpowering emotions for the soldiers and their passion for fighting. It is furthermore found that the locally constructed masculinities informed the context ofthe Afghanistan War. This has implications for the way we understand masculinities especially in war poetry. As the paper demonstrates, the multiple ways in which the notion of masculinity is manifested in war poems point to the need to break free from the stereotypical understandings of warriors from conservative religious backgrounds.  Este artículo examina de forma crítica las canciones de guerra y los poemas de hombres que lucharon en la guerra afgana posterior al 11/9. El estudio ubica el análisis dentro de las influencias socioculturales que dejaron un impacto en los soldados-hombre, permitiendo que se revelara un "micro mapa" de la masculinidad en los escritos de estos hombres. Usando técnicas de análisis temático, se analizaron cincuenta canciones de guerra y poemas de los años 2007 y 2008 a través del lente del desarrollo de la masculinidad. La investigación sobre las canciones y poemas de guerra encontró que la dimensión performativa de las masculinidades en la guerra se extiende alrededor de los temas de los guerreros jóvenes; armas; armas y maquinaria de guerra; estado de la política y necesidad de un gobierno islámico; el motivo del color rojo; y glorificación de la muerte. La religión del Islam, su tierra natal Afganistán y su cultura tradicional actúan de forma constante como un combustible para evocar emociones abrumadoras para los soldados y su pasión por la lucha. Se observa que las masculinidades construidas localmente informan sobre el contexto de la guerra afgana. Esto tiene implicaciones en la forma en que entendemos las masculinidades especialmente en la poesía de guerra. Como demuestra el artículo, las múltiples formas en que se manifiesta la noción de masculinidad en los poemas de guerra apuntan a la necesidad de liberarse de las comprensiones estereotipadas de guerreros de contextos religiosos conservadores