283 research outputs found
USING LOOP THERMOSYPHON TO WASTE HEAT REMOVAL FROM POWER ELECTRONIC COMPONENT
Loop thermosyphon is a simple and reliable device providing several times higher heat transfer than convectional coolers used in cooling electronic. The paper deals with the cooling of power electronic component by means of this device. The main object of the paper is design and construction of the device to provide heat removal from the electronic component. Paper describes function principle of loop thermosyphon, testing of the function and measurement of cooling efficiency in dependence on input electric power of the electronic component. The findings from measurement of loop thermosyphon cooling efficiency are compared with natural convective alumina cooler on the end of paper
Signalling and control of locomotion in a T lymphocyte line
This study explored the intracellular signals that control the acquisition and maintenance of locomotory capacity in T lymphocyte line Jurkat. The majority of the actively dividing Jurkat cells show an immotile morphology. It was possible to induce the polarization and locomotion in the majority of these cells by culture in the presence of dibutyryl cyclic AMP for at least 3 days. Such culture resulted in a decrease in the Jurkat cell size, in a block in the first gap phase of the cell cycle and in an increased surface expression of CD3. These cells displayed a constitutively motile behaviour which was temperature and energy dependent. The polarization of the Jurkat cells was permanently reversed, in a short-term assay, by PH A and drugs which increase the phosphorylation of intracellular proteins (phorbol esters and phosphatase inhibitors) and which increase intracellular concentrations of cAMP. In contrast, the polarization was reversed transiently following a stimulation of the T cell receptor complex by an CD3 monoclonal antibody or when the intracellular Ca2+ stores were emptied as a result of the inhibition of Ca2+ pump by thapsigargin. The effect involving PH A, CD3 and thapsigargin is dependent on the presence of extracellular Ca2+. The evidence suggests that PKC is the most important and common element in the inhibition of the polarization process in Jurkat cells. Indeed, the activity of most agents could be partially and dose-dependently inhibited using PKC inhibitors. The signal, which leads to the inhibition of polarization in dbcAMP- cultured Jurkat cells is coupled by a tyrosine kinase as well as by a pertussis toxin-sensitive G protein
Testing key messages about extending cervical screening intervals
Objectives: We tested the impact of different messages about the rationale for extended screening intervals on acceptability of an extension.
Methods: Women in England aged 25-49 years (n=2931) were randomised to read different messages about extending intervals from 3 to 5 years. Outcome measures were general acceptability and six components from the Theoretical Framework of Acceptability (TFA).
Results: The control group were less likely to find the change acceptable (43%) than the groups who saw additional messages (47-63%). Women who saw messages about interval safety, test accuracy or the speed of cell changes had more positive affective attitudes, higher ethicality beliefs, a better understanding of the reasons for the interval change and were more likely to believe that 5-year intervals would be safe. Being up-to-date with screening and previous abnormal results were associated with finding 5-yearly screening unacceptable.
Conclusions: Emphasising the slow development of cell changes following an HPV negative result and the safety of longer intervals, alongside messages about the accuracy of HPV primary screening is important
THE IMPACT OF LHP POSITION TO REMOVE WASTE HEAT FROM THE POWER COMPONENTS
Given the rapid progress in the electronics industry, the thermal management of electronics components becomes an important and serious issue. Natural and forced cooling are often deficient. One possibility for heat dissipation for high heat flux is using loop heat pipe. A loop heat pipe (LHP) is a two-phase device with extremely high effective thermal conductivity that utilizes pressure difference in wick to circulate working fluid. It was invented in Russia in the early 1980’s. LHP is composed by an evaporator, a condenser, a compensation chamber (reservoir) and a vapor and liquid lines. Only the evaporator and part of the compensation chamber are equipped with a wick structure. The use of the wick structure in the evaporator provides a stable physical interface between the liquid and the vapor phases in the LHP. This work deals with the design of LHP for cooling of Insulated gate bipolar transistor and impact of tilt angle of LHP on temperature of transistor. The LHP position is changed from the vertical position (90°) to the horizontal position (0°) during the measurement. The LHP evaporator is made up with copper pipe and alumina saddle. Inside of the evaporator is wick structure and it is made from copper powder. The condenser is made as a tube heat exchanger. The water temperature for cooling is set at 20°C and it is regulated by a thermostat. The temperatures are measured with the thermocouples. As the working fluid was used distilled water. The maximum permissible temperature of transistor is 100°C
The impact of age-relevant and generic infographics on knowledge, attitudes and intention to attend cervical screening: A randomized controlled trial
OBJECTIVES: Cervical screening uptake in England is falling. Infographics could strengthen intention to attend, increase positive attitudes and improve knowledge. Age targeting could improve these outcomes further. We tested the impact of generic and age-targeted infographics. DESIGN: A randomized controlled trial using an age-stratified, parallel-group design. METHODS: Women aged 25-64 (n = 2095) were recruited through an online panel and randomized to see one of the three infographics. We tested: (i) impact of a generic cervical screening infographic compared to a control infographic on an unrelated topic with all screening age women and (ii) impact of an age-targeted infographic compared to a generic cervical screening infographic with older women (50-64 years). Intentions, knowledge and attitudes were measured. RESULTS: Women aged 25-64 years who viewed the generic infographic had significantly higher intentions [F(1, 1513) = 6.14, p = .013, η p 2 = .004], more accurate beliefs about the timeline of cervical cancer development (OR: 5.18, 95% CI: 3.86-6.95), more accurate social norms (OR: 3.03, 95% CI: 2.38-3.87) and more positive beliefs about screening benefits (OR: 2.23, 95% CI: 1.52-3.28) than those viewing the control infographic. In the older age group, there was no significant difference in intention between those viewing the generic versus age-targeted versions [F(1, 607) = .03, p = .853, η p 2 < .001], but the age-targeted version was more engaging [F(1, 608) = 9.41, p = .002, η p 2 = .015]. CONCLUSIONS: A cervical screening infographic can result in more positive attitudes and better knowledge and may have a small impact on intentions. Although age targeting did not affect intention, it had a positive impact on engagement and may therefore be useful in encouraging women to read and process materials
The Effects of euro Adoption on the Slovak Economy
In this study we assess the effects of euro adoption from an economic perspective. The benefits and disadvantages of Slovak entry to the euro area were discussed already when the euro adoption strategy was adopted. This analysis utilizes the latest information, using the set euro adoption date and the chosen euro adoption scenario. We attempt to quantify the most important effects, so that the costs and benefits can be compared. The costs and risks related to the euro area entry will depend on economic conditions and policies. Therefore we analyze the economic policies, which should support euro adoption, the issues of optimal timing of euro area entry and the impacts of euro adoption on citizens, businesses and the state administration.
Prevalence of donor-transmitted atherosclerosis—Clinical utility of intracoronary ultrasound early after heart transplantation. A single-center study
AbstractIntroductionCoronary allograft vasculopathy (CAV) is one of the main factors limiting long-term survival following orthotopic heart transplantation (HTx). Whether or not and, if so, how donor-transmitted atherosclerosis (DCA) affects the post-transplant course of the allograft recipient is still unclear. Conventional coronary angiography is a moderately accurate technique for DCA detection as it will reveal only the more gross morphological lesions. By contrast, intravascular ultrasound (IVUS) has been shown to be a much more sensitive technique for CAV and DCA detection. In our study we sought to determine the prevalence of DCA in our HTx patient population and identify main risk factors of DCA based on donor characteristics.Patients and methodsWe performed a retrospective analysis of data of 119 patients (92 men, 27 women) undergoing transplantation in our center from August 2006 through September 2012, who had survived their first post-transplant month and had coronary angiography and IVUS.ResultsDCA was present in 39 patients, and not documented in 80 patients. The main risk factors for DCA included donor age, cigarette smoking, and hypertension; the other parameters were not shown to be statistically significant. In-hospital mortality was low in both groups (DCA positive and DCA negative), with one patient dying in either group. One-year mortality rates post-HTx were likewise almost identical in both groups (15.4% and 15% in DCA positive and negative, respectively).ConclusionThe prevalence of DCA in our patients was 32.8%, with major risk factors for DCA including donor age, cigarette smoking, and hypertension. As age seems to be the strongest predictor, coronary angiography should be a routine examination in individuals aged over 40 years; the examination should be considered in younger individuals with a cluster of several of risk factors. The 1-year survival in this selected patient population was identical in both groups, the implication being that the diagnosis of DCA had no effect on 1-year survival post-HTx
Suffix interference and processing speed effects in young and older adults' visual feature binding
There is debate regarding whether or not working memory for bound visual objects is more age-sensitive than that for individual visual features. To investigate this potential ‘age-related binding deficit’, we administered a visual recognition task to young and healthy older adults. In experiment 1, coloured shapes were sequentially presented, either with or without a subsequent, to-be-ignored, coloured shape (suffix). Performance was generally better with the individual shape memory test relative to binding (coloured shape test), although a greater binding deficit was found in older than young adults, regardless of whether or not a suffix had been presented. Additional analyses identified that the deficit was only observable within the lure (test probe absent) trials, suggesting that it is more likely to be observed in circumstances that encourage overwriting of bound objects at test. A second experiment will also be presented, which was aimed at assessing the potential role of processing speed in visual binding. Both age groups performed the task at relatively slow and fast encoding speeds, tailored to each group, allowing us to explore the circumstances that may lead to binding deficits and/or serial position curves in both young and older adults
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Modeling of Spinel Settling in Waste Glass Melter
Our objective is to determine the fraction and size of spinel crystals in molten HLW glass that are compatible with low-risk melter operation. To this end, we are investigating spinel behavior in HLW glass and obtaining data to be used in a mathematical model for spinel settling in a HLW glass melter. We will modify the current glass-furnace model to incorporate spinel concentration distribution and to predict the rate of spinel settling. Also, we will determine the nucleation agents that control the number density and size of spinel crystals in HLW glass
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