Calculation procedure for transient heat transfer to a cooled plate in a heated stream whose temperature varies arbitrarily with time

Heat transfer equations have been developed to calculate surface temperature and surface heat flux for cooled flat plate when temperature of fluid passing over leading edge varies arbitrarily

Application of differential similarity to finding nondimensional groups important in tests of cooled engine components

The method of differential similarity is applied to the partial differential equations and boundary conditions which govern the temperature, velocity, and pressure fields in the flowing gases and the solid stationary components in air-cooled engines. This procedure yields the nondimensional groups which must have the same value in both the test rig and the engine to produce similarity between the test results and the engine performance. These results guide the experimentalist in the design and selection of test equipment that properly scales quantities to actual engine conditions. They also provide a firm fundamental foundation for substantiation of previous similarity analyses which employed heuristic, physical reasoning arguments to arrive at the nondimensional groups

The Effects of Repeated Dyspnea Exposure on Response Inhibition

In order to treat dyspnea (=breathlessness) successfully, response inhibition (RI) as a major form of self-regulation is a premise. This is supported by research showing that self-regulation is associated with beneficial behavioral changes supporting treatment success in patients. Recent research showed that dyspnea has an impairing effect on RI, but the effects of repeated dyspnea exposure on RI remain unknown. Therefore, the present study tested the effects of repeated resistive load-induced dyspnea on RI over a 5-day period. Healthy volunteers (n = 34) performed the standard version of the Stroop task during baseline and dyspnea conditions on the first and fifth testing day and underwent an additional dyspnea exposure phase on each testing day. Variables of interest to investigate RI were reaction time, accuracy as well as the event-related potentials late positive complex (LPC) and N400 in the electroencephalogram. Reduced accuracy for incongruent compared to congruent stimuli during the dyspnea condition on the first testing day were found (p < 0.001). This was paralleled by a reduced LPC and an increased N400 for incongruent stimuli during the induction of dyspnea (p < 0.05). After undergoing dyspnea exposure, habituation of dyspnea intensity was evident. Importantly, on the fifth testing day, no differences between baseline, and dyspnea conditions were found for behavioral and electrophysiological measures of RI. These findings demonstrate that the impairing effect of dyspnea on RI disappeared after repeated dyspnea exposure in healthy participants. Translated to a clinical sample, it might cautiously be suggested that dyspnea exposure such as dyspnea perceived during physical exercise could reduce the impairing effect of dyspnea on RI which might have the potential to help increase self-regulation abilities and subsequent treatment efforts in dyspneic patients

Делистинг как инструмент управления ценностью для акционеров

Цель: выделить драйверы, влияющие на решение о делистинге, с целью построения инвестиционной стратегии для потенциальных бенефициаров сделок ухода публичных компаний с биржи Задачи: 1) Провести теоретический обзор проблемы исследования с идентификацией природы и принципов феномена делистинга; 2) Проанализировать главные причины для добровольного делистинга; 3) Провести обзор процедур ухода с биржи; 4) Провести эмпирическое исследование относительно оценки влияния независимы переменных на решение о делистинге; 5) Предложить рекомендации для менеджеров и индивидуальных инвесторов; 6) Сделать общее заключение, суммируя результаты и подтверждая достижение цели. Основные результаты: Рекомендации сформированы в таблицы для распространения между определенными целевыми группами. Данные материалы считаются удобными в использовании и не требуют глубокого профессионального погружения в вопросы феномена делистинга. Предложена инвестиционная стратегия для бенефициаров сделок ухода публичных компаний с биржи.Goal: to identify drivers of delisting process in order to build investment strategy for potential beneficiaries of the going private transactions Objectives: 7) To make the theoretical overview of the research problem with identification of nature and principles related to delisting phenomena; 8) To analyze the main reasons for voluntary delisting; 9) To overview procedures for going private transactions; 10) To conduct an empirical study regarding evaluation of variables influenced the decision to delist; 11) To provide the recommendations applicable for managers and individuals; 12) To make a general conclusion on the research paper summing up all the results and confirming of achievement the stated goal. Main results: The recommendations are formed in tables for distribution among particular target groups and considered to be user-friendly and adopted for different level of diving into voluntary delisting topic. The managerial implications suggest built investment strategy for those who are interested in obtaining benefits from public-to-private transactions

Transient Heat Transfer between a Plate and a Fluid whose Temperature Varies Periodically with Time

Using the method of complex temperature in conjunction with the Laplace transformation, an exact analytical solution is found for the transient, conjugate, forced convection problem consisting of a plate, whose base is insulated, interacting with a fluid, moving in a steady slug fashion, whose temperature, at points far from the plate, varies sinusoidally with time. Simple quasi-steady results are derived for comparison. Also presented is a method for determining the qualitative conditions under which one might expect a quasi-steady analysis to be valid in a general problem.</jats:p

Etude moléculaire des étapes initiales d'importation de protéines mitochondriales

Mitochondria play an important role in numerous eukaryotic cellular processes with 99% of their ~1500 different proteins being encoded by the nuclear genome and synthesized in the cytosol. Consequently, the proper functioning of mitochondria depends on correct import, localization and folding of these so-called precursor/client proteins. The translocase of the outer membrane (TOM) complex specifically recognizes the precursor proteins via their targeting signals and enables their translocation through the outer membrane. Among the import machineries downstream from the TOM complex, a sole chaperoning system of the intermembrane space, TIM holdase chaperones, is ensuring aggregation-free transport of highly hydrophobic membrane proteins through the intermembrane space.In the first part I am showing the characterization of the membrane protein client binding on two TIM chaperones which explains the TIM’s chaperones substrate specificity on an atomic level. Previously, the conserved hydrophobic binding site on TIM9.10 chaperone has been revealed integrating solution NMR experiments with different biophysical and biochemical assays and molecular modeling. The “fuzzy” mode of interaction, where the client binds in an unfolded, translocation-competent state, sampling a multitude of conformations, supports apparent contradictory role of TIM chaperones: protecting highly hydrophobic membrane clients from the aggregation by tight binding, and also the transfer of the client to the downstream insertase without any significant energetic barrier. Here we show that a small pool of membrane protein clients with additional soluble domain shows preference in binding to the other, non-essential TIM8.13 chaperone. We showed that for this type of client, the binding is not only mediated by the hydrophobic patches on the chaperone, but that it additionally involves a network of polar interactions at a distinct binding site that only TIM8.13 provides. Integrating NMR, SAXS and molecular dynamic simulations provides us with two models of chaperone-client binding for two structurally very similar chaperones.In the second part I am showing the interaction studies of the three cytosolic receptor domains of the TOM import machinery. The Tom receptors, Tom20, Tom22 and Tom70, specifically recognize their clients, the precursor proteins, via the targeting signals of the client. Due to receptors partially overlapping function shown in vivo, the mechanism of client recognition and interaction between three different receptors on the atomic level remains to be characterized. We used solution NMR spectroscopy, biochemical and biophysical techniques to study and characterize: (i) the apo cytosolic domains of the Tom receptors, (ii) Tom receptor--client protein complexes, (iii) interactions between the individual Tom receptors and (iv) Tom receptor(s) interactions with the cytosolic co-chaperone Xdj1. These are challenging studies due to the dynamic, flexible - and in case of Tom70, relatively big - nature of the Tom receptor domains. Our results reveal an interaction pattern of cytosolic, intrinsically disordered domain of Tom22 with the other two receptors and the cytosolic co-chaperone, suggesting an universal role of Tom22 as a client replacement in the Tom20, Tom70 and Xdj1 client binding site. Such interaction may be required for the release of the client protein and its transfer from the Tom20 receptor (or Tom70 or Xdj1) through the outer membrane Tom40 pore. Together, obtained results are providing functional clues about the sequence of the events during the first steps of the mitochondrial protein import.Chez les eucaryotes, les mitochondries jouent un rôle important dans de nombreux processus cellulaires. 99 % des ~1500 protéines mitochondriales sont codées par le génome nucléaire et synthétisées dans le cytosol. Par conséquent, le bon fonctionnement des mitochondries dépend de l'importation, de la localisation et du repliement correct de ces protéines dites précurseurs/clientes. Le TOM complexe formant la translocase de la membrane externe (TOM) reconnaît spécifiquement les protéines précurseures via leurs signaux d’adressage et permet leur translocation à travers la membrane externe. En aval du complexe TOM, un seul système de chaperonnes de l'espace intermembranaire, les chaperonnes TIM, assurent le transport des protéines membranaires hautement hydrophobes à travers l'espace intermembranaire.Dans la première partie, je montre la caractérisation de la liaison de différentes protéines membranaires clientes à deux chaperonnes TIM, en cherchant à expliquer leur spécificité à un niveau atomique. Auparavant, en intégrant des expériences de RMN en solution avec différentes techniques biophysiques et biochimiques ainsi que la modélisation moléculaire, le site de liaison hydrophobe conservé sur la chaperonne TIM9.10 a été révélé. Le mode d'interaction "flou", où le client se lie dans un état déplié et translocation-compétent, échantillonnant une multitude de conformations, soutient le rôle apparemment contradictoire des chaperonnes TIM: protéger les clients membranaires hautement hydrophobes de l'agrégation par une liaison étroite, en autorisant simultanément leur transfert à l'insertase en aval sans barrière énergétique significative. Nous montrons ici qu'un petit groupe de clients de protéines membranaires possédant un domaine supplémentaire soluble, montre une préférence pour la chaperonne TIM8.13, non essentielle dans la levure. Pour ce type de client, la liaison n'est pas seulement médiée par les patches hydrophobes de la chaperonne, mais elle implique également un réseau d'interactions polaires sur un site de liaison distinct que seul TIM8.13 fournit. L'intégration des données RMN et SAXS avec des simulations de dynamique moléculaire nous fournit deux modèles de liaison chaperonne-client pour deux chaperonnes structurellement très similaires.Dans la deuxième partie, je présente les études d'interaction des domaines cytosoliques de trois récepteurs de la machinerie d'importation TOM. Les récepteurs Tom20, Tom22 et Tom70 reconnaissent spécifiquement les protéines précurseurs via les signaux d’adressage. En raison du chevauchement partiel des fonctions de ces récepteurs démontrées in vivo, le mécanisme de reconnaissance des clients ainsi que l'interaction entre les trois récepteurs reste à caractériser au niveau atomique. Nous avons utilisé la spectroscopie RMN en solution, ainsi que des techniques biochimiques et biophysiques pour étudier et caractériser (i) les domaines cytosoliques des récepteurs en absence de client, (ii) les complexes récepteur-protéine cliente, (iii) les interactions entre les récepteurs et (iv) les interactions entre les récepteurs Tom et une co-chaperonne cytosolique. Ces études constituent un défi en raison de la nature dynamique, flexible et, dans le cas de Tom70, relativement grande des domaines des récepteurs. Nos résultats révèlent un modèle d'interaction du domaine cytosolique intrinsèquement désordonné de Tom22 avec les deux autres récepteurs et avec la co-chaperonne cytosolique Xdj1. Ce modèle suggère un rôle universel de Tom22 qui implique le remplacement du client dans son site de liaison sur Tom20, Tom70 et Xdj1. Une telle interaction peut être nécessaire pour la libération de la protéine cliente et son transfert du récepteur Tom20 (ou Tom70 ou Xdj1) à travers le pore Tom40 de la membrane externe. Ensemble, les résultats obtenus fournissent des indications fonctionnelles sur les premières étapes de l'importation des protéines mitochondriales