75 research outputs found
An approach for energy management of renewable energy sources using electric vehicles and heat pumps in an integrated electricity grid system
The demand for electricity has been increasing worldwide and it is predicted that this trend will be particularly reinforced in developing countries by the gradual electrification of the transport sector and heat generation in buildings. The energy supply infrastructure required to meet the additional electricity demand should be carefully managed in light of the climate change carbon emission targets and commitments. A large proportion of the new electricity loads will be met from renewable sources. Therefore, means of power storage become vital to smooth out the intermittent nature of these energy supplies. The introduction of Electric Vehicles (EVs) could provide a viable and dynamic power storage solution through the concept of Vehicle-to-everything (V2X). This involves the storage of renewable energy (RE) in EV batteries during the charging cycle and restitution to the grid (V2G) or homes (V2H) when needed. In this context, this paper presents a methodology involving several strategies to stabilise the grid system and examines the impact of various types of EVs and heat pumps (HPs) for supplying heat in buildings. The results of this research approach show that the synergy of using V2H could reduce the carbon footprint of a typical domestic building in the United Kingdom (UK) by up to 87% and potentially recover up to 21.9 kWh/day of surplus renewable energy
Investigation the effect of propranolol, metoprolol and carvedilol on spermatogenesis in rat testis
Background: Coronary arterial diseases are one of the increasing disease around the worldwide. Because of common using of the beta blockers, we aimed to investigate the effect of different beta-adrenergic receptor blockers on spermatogenesis in male rats.Methods: Adult male Sprague Dawley rats were obtained. Totally 32 rats homogenized according to their weight and divided into four groups that each one includes eight rats. Three of groups were determined as drug groups and remained groups were determined as a control group. Propranolol 40mg/kg, Metoprolol succinate 60mg/kg, Carvedilol 30mg/kg dosage was given by oral gavage within the saline solution, and the only saline solution was given to control group for 21 days, respectively. After 21 days rats were sacrificed, and testis were extracted. Then, histopathologic evaluation was performed.Results: There was statistical significance both right and left testis volume of experimental between control and carvedilol groups (p<0.05). There was statistical histopathological significance between control and carvedilol (p<0.05), control and propranolol (p<0.05), metoprolol succinate and propranolol (p<0.05), metoprolol succinate and carvedilol groups (p<0.05), respectively.Conclusions: Beta-adrenergic receptor blockers have adverse effects on spermatogenesis. Especially propranolol and carvedilol that were non-selective, effects spermatogenesis worse than selective beta blockers such as metoprolol succinate. Extensive use of these drugs may affect spermatogenesis in male, so male patients who have a complaint of infertility should be questioned regarding the use of beta blockers
Towards sustainable urban living: A holistic energy strategy for electric vehicle and heat pump adoption in residential communities
Electric vehicles (EVs) and heat pumps (HPs) are key in reducing carbon emissions from transportation and domestic heating, yet their adoption may increase peak load demands on electrical networks. One of the aims of this research is to assess the potential impact of uncontrolled EV charging on community-scale distribution networks, exploring how this could stress the existing electrical infrastructure. It also explores the role of EVs in Vehicle-to-Grid (V2G) and smart charging applications, aiming to enhance community distribution systems. The study investigates the maximum stabilisation level achievable under various scenarios, highlighting the importance of smart energy management in integrating renewable energy and addressing uncertainties in the modelling process. Additionally, this study discusses the proposed systems' scalability, consumer behaviours' impact on the suggested energy solutions, and the potential implications of recent technological advancements for simulated communities. The research employs a sophisticated, integrative approach, combining stochastic methods with several robust energy software. Key findings suggest that uncontrolled EV charging can lead to grid capacity issues at high EV penetration levels, particularly during colder months. While smart charging and V2G technologies can moderate peak loads in many scenarios, achieving 100% sustainable technology integration requires enhanced energy management or increased network capacity, especially in winter. Wind and solar power integration demonstrates strategic complementarity, particularly in winter, enhancing the reliability and stability of the community grid. It is also observed that peak solar generation hours misalign with the community's highest demand times, posing challenges for solar energy utilisation in EV charging in residential-based area
The effects of supraphysiological oestrogen levels on ventricular repolarisation parameters
Background: The frequency of arrhythmic death developing without a structural cardiac disease is higher in women. Also, female sex is an independent risk factor regarding development of torsades de pointes. Several studies have been conducted on the physiological and therapeutic effects of sex hormones on the cardiac conduction system.
Aim: In this study we aim to examine the effect of hormonal changes, especially supraphysiological E2 level changes occurring during in vitro fertilisation treatment, on ventricular repolarisation parameters.
Methods: The study included female patients aged between 23 and 39 years, who were administered controlled ovarian hyperstimulation treatment. Patients’ electrocardiograms and blood samples were obtained and analysed before and after the ovarian hyperstimulation treatment.
Results: Mean QTc intervals before ovarian hyperstimulation were 411.9 ± 23.7 ms. Measurements during oestradiol peak were calculated as 420.7 ± 23.3 ms, and the QTc interval increase was significant (p = 0.007). Corrected QT dispersion averages were not significant before or after hyperstimulation (53 ± 17 ms vs. 54.5 ± 18.2 ms, respectively, p > 0.05). Tp-e, J-T peak, and PR dispersion changes were not significant after the ovarian hyperstimulation therapy.
Conclusions: Supraphysiological oestradiol levels that occur during controlled ovarian hyperstimulation cause prolongation of QTc intervals, but not to a pathological level. Although this prolongation is not significant in healthy individuals, it might increase ventricular arrhythmia risk in patients with congenital long QT syndrome and in patients taking medication that prolongs QT
Effects of Chemical Sympathectomy on Contralateral Testicular Histology and Fertility in Unilateral Vasectomy
Unilateral obstruction or injury to the vas deferens can result in significant injury to the contralateral testicle. Although various pathways have been proposed, the mechanism of contralateral testicular deterioration remains controversial. The present animal study was performed to evaluate the effects of unilateral vasectomy on ipsilateral and contralateral testicular histology and fertility in rats that were chemically sympathectomized neonatally. The study comprised 40 male albino rats: 20 received a placebo and the other 20 underwent chemical sympathectomy neonatally. When 60 days old, each group of 20 rats was divided into two groups that underwent either a sham operation or an operation to create unilateral left vasectomy. Eight weeks after surgery, each male rat was housed with two known fertile female rats for 25 days, and then their testes were harvested. Mean seminiferous tubular diameters (MSTD) and mean testicular biopsy scores (MTBS) were determined for each testis. Although MSTD and MTBS were not significantly different between groups, chemical sympathectomy prevented the decrease in total fertility rates of the rats with unilateral left vasectomy in our study. Prevention of this decrease by chemical sympathectomy suggests that the sympathetic nervous system may play a role in the testicular degeneration associated with vasectomy
The possible protective effects of dipyridamole on ischemic reperfusion injury of priapism
Hydroxyurea-associated multiple squamous cell carcinoma developed on the dermatomyositis-like eruption
Examination of Student Growth Using Gain Score and Categorical Growth Models
WOS: 000491859900011In this study, gain score, and categorical growth models were used to examine the role of student (gender and socioeconomic level) and school characteristics (school size and school resources) in the student growth on comprehension skills in language. The participants of this study were 2,416 sixth-grade students in 2011 who became seventh-grade students in 2012. The data was collected through two achievement tests, student and school questionnaires. Two achievement tests were calibrated using the Rasch Model and were scaled using the concurrent estimation method. Moreover, the cut-off scores of these tests were determined by using the bookmark method. Students' growth was modelled with the gain score and categorical growth models. All data was analyzed using multilevel models. Results showed that some students did not achieve sufficient gains to advance to higher performance levels. Although some schools' average gains were higher, their performance was still not significant enough in terms of tests' standards. Moreover, the analyses demonstrated that the student gain scores and growth categories varied significantly among the schools. In addition, the study was able to determine student and school characteristics that have an impact on the students' gain scores and categorical growth. Given the different aspects gained about students' performance with these models, it is recommended to utilize different growth models in schools
The Factors that Predict the Frequency of Activities Developing Students’ Listening Comprehension Skills
AbstractListening comprehension plays an important role in one's educational and daily life. This comprehension skill is not adequately developed in the world and this is a fact that is faced in every aspect of our daily lives. Bearing in mind that listening comprehension affects the students’ success not only course, but also in other subjects and lessons, the necessity in developing such skills becomes significantly apparent. From this perspective, leading and directing the activities that will develop listening comprehension skills is only possible by determining the factors that affect them.The aim of this study is to determine the factors that predict frequency of activities developing student's listening comprehension. Participants of this study carried out with 281 elementary 5th grade students. “Listening Comprehension Activities Test” and “Student Information Questionnaire” have been used for collecting data in. According to the results, writing summary about reading texts in classroom, giving homework related with reading texts, giving free reading time to students and the frequency of student’ using radio, mp3, Cd player and computer have an importance role on developing of student’ listening comprehension
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