An Investigation on the Parameters that Affect the Performance of Hydrogen Fuel Cell

AbstractMost of the energy used in the world is obtained from fossil fuels. Some reasons like air and environmental pollution, high-energy costs and depletion of fossil fuels, increased the importance of studies about new and renewable energy sources in the world. Among the new and renewable energy sources hydrogen has great importance. Hydrogen which exists in great amounts in the world has the highest energy content per unit mass. The subject of fuel cells is one of the main research topics in hydrogen energy. The purpose of this study, is to analyze the performance of fuel cells. to do this a model of fuel cell is created in Finite element method program. membrane thickness and electrolyte type of fuel cell is selected as variables

Fen bilgisi öğretmen adaylarının bilgi ve iletişim teknolojilerini kullanmaları ve bu teknolojileri öğrenme - öğretme sürecine entegrasyonları hakkındaki görüşleri

Bu çalışmanın amacı, fen bilgisi öğretmen adaylarının bilgi ve iletişim teknolojilerini (BİT) kullanım düzeyleri ve bu teknolojileri öğrenme öğretme sürecine entegrasyonları hakkındaki görüşlerini incelemektir. Bu amaçla birlikte, fen bilgisi öğretmen adaylarının BİT kullanım düzeylerinin bazı demografik değişkenler açısından farklılık gösterip göstermediği ve bunun yanında BİT'in öğrenme-öğretme sürecine entegrasyonu hakkındaki görüşleri de araştırılmıştır. Araştırmanın katılımcılarını Fırat Üniversitesi Eğitim Fakültesi Fen Bilgisi Öğretmenliği 3. ve 4. sınıflarında öğrenimlerine devam eden 144 öğretmen adayı oluşturmaktadır. Araştırma verileri "Bilgi ve İletişim Teknolojileri Kullanım Düzeyi Anketi" ve yarı yapılandırılmış görüşme yöntemi ile toplanmıştır. Elde edilen veriler, betimsel istatistikler ve bağımsız gruplar t Testi kullanılarak analiz edilmiştir. Görüşmeler ses kayıt cihazı ile kayıt altına alınmıştır. Görüşmelerin analizinde içerik ve betimsel analiz yöntemleri kullanılmıştır. Araştırmada elde edilen verilerin analizi sonucunda, fen bilgisi öğretmen adaylarının BİT kullanım düzeyleri açısından kendilerini orta düzeyde yeterli gördükleri belirlenmiştir. Ayrıca fen bilgisi öğretmen adayları BİT’in öğrenme-öğretme sürecine entegrasyonunun çok faydalı olduğunu, kendilerine zaman kazandırdığını, işlerini kolaylaştırdığını ve öğrencilerin derse olan ilgisini artıracağını belirtmişlerdir.The aim of this study is to examine the level of science teacher candidates' use of information and communication technologies (ICT) and their opinions on the integration of these technologies into the teaching-learning process. For this purpose, it was researched whether the ICT use levels of science teacher candidates differ significantly in terms of some demographic variables, as well as their opinions on the integration of ICT into the learning-teaching process. The participants of the research constitute 144 teacher candidates studying in the 3rd and 4th grades of Science Teacher Training Department of Fırat University Faculty of Education. The research data were collected using the "ICT Usage Survey" and the semistructured interview method. The obtained data were analyzed by using descriptive statistics and independent groups t Test. The interviews were recorded with a voice recorder. Content and descriptive analysis methods were used in the analysis of the interviews. The study results reveal that the science teacher cantidates considered themselves intermediate grade in terms of ICT usage levels. In addition, science teacher candidates have indicated that the integration of ICT into the learning-teaching process is so beneficial and it saves them time, facilitates their work, and increases the interest of students in the classroom

Transcatheter Closure of Atrial Septal Defect and the Effects on Right Ventricular Function; Strain and Strain Rate Echocardiography

29th Turkish Cardiology Congress of the Turkish-Society-of-Cardiology (TSC) with International Participation -- OCT 26-29, 2013 -- Antalya, TURKEYWOS: 000329858400409Turkish Soc Cardio

Seed fatty acid amounts of some Salvia L. taxa in Elazig

Fatty acid amounts in mature seeds of thirteen Salvia L. taxa were determined by using gas chromatography in this study. Palmitic acid (C 16:0; 4.2-11.7 %) was major saturated fatty acid among in the studied Salvia species. Results of present study indicated that the seed oils of studied Salvia L. taxa have oleic acid (C 18:1 n-9), linoleic acid (C18:2 n-6) and linolenic acid (C 18:3 n-3) as unsaturated major fatty acids. The highest oleic acid (C 18:1 n-9) amount is found in S. tricholoda Bentham (30.7 %) but it is found at the lowest level in S. verticillata L. subsp. verticillata (11.3 %). Also, linoleic acid (C 18:2 n-6) amount was highest in S. euphratica var. leicaliyeina (60.4 %) but it was found at the lowest levels in S. aethiopis (12.1 %). However, linolenic acid (C18:3 n-3) amount of the Salvia L. seeds studied showed the greatest variation (0.5-57.8 %). As a result, present study determined that Salvia L. species had the highest unsaturated fatty acid amounts (81.5-94.4 %) and low saturated fatty acid amounts (5.8-18.3 %).Bu çalışmada, on üç Salvia L. taksonu tohumlarındaki yağ asidi miktarları gaz kromatografisi kullanılarak tespit edildi. Çalışılan Salvia türleri arasında palmitik asit (C:16 0; % 4.2-11.7) başlıca doymuş yağ asididir. Bu çalışmanın sonuçları çalışılan Salvia L. taksonlarının tohumlarında major doymamış yağ asitleri olarak oleik asit (C 18: 1 n-9), linoleik asit (C 18: 2 n-6) ve linolenik asitin (C 18: 3 n-3) olduğunu göstermiştir. En yüksek oleik asit (C 18: 1 n-9) miktarı S. tricholoda Bentham’da (% 30.7) iken en düşük oleik asit miktarı S. verticillata L. subsp. verticillata’da (% 11.3) bulunmuştur. Ayrıca, linoleik asit (C 18:2 n-6) miktarı en yüksek oranda S. euphratica var. leicaliyeina (% 60.4)’da bulunurken en düşük oranda ise S. aethiopis (12.1 %)’te bulunmuştur. Bununla birlikte çalışılan Salvia tohumlarının linolenik asit (C18:3 n-3) miktarları büyük varyasyon göstermiştir (% 0.5-57.8). Sonuç olarak bu çalışma Salvia L. türlerinin yüksek oranda doymamış yağ asidi miktarına (% 81.5-94.4) ve düşük oranda doymuş yağ asidi miktarına (% 5.8-18.3) sahip olduklarını belirlemiştir

Effects of magnesium sulphate on liver ischemia/reperfusion injury in a rat model

Aim: To investigate the protective efficacy of magnesium sulphate in a model of rat liver ischemia-reperfusion (I/R) injury. Method: 32 adult female Wistar-Albino rats (250 to 350 g) were used in this experimental study. Rats were divided into 4 groups according to liver ischemia and magnesium sulfate application methods. Group 1 (C); control, group 2 (M); magnesium sulphate, group 3 (I/R); liver I/R, group 4 (I/R+M); I/R + magnesium sulphate treated. The blood samples were centrifuged for the study of aspartate aminotransferase (AST), alanine aminotransferase, prothrombin time (PT), international normalized ratio (INR) troponin I, total antioxidant status (TAS), total oxidant status (TOS) assays. The livers of the animals were removed at the end of the study and samples were taken for histopathological examination. Results: AST and INR values were significantly decreased in I/R+M group compared to I/R group. There was no significant difference in ALT values of the groups. Although not statistically significant, the TAS values were increased in I/R + M group compared to I/R group rats. In addition, the value of TOS was found to be lower in I/R + M group rats. In the histopathological examination, the mean values of apoptosis and necrosis were lower in the IR+M group compared to the IR group. Conclusion: The main finding of the present study suggested that magnesium sulphate pretreatment moderately decreased the liver damage through its anti-inflammatory and anti-oxidant effects in a rat model of liver I/R

DNA Repair Gene Polymorphism and the Risk of Mitral Chordae Tendineae Rupture

Polymorphisms in Lys939Gln XPC gene may diminish DNA repair capacity, eventually increasing the risk of carcinogenesis. The aim of the present study was to evaluate the significance of polymorphism Lys939Gln in XPC gene in patients with mitral chordae tendinea rupture (MCTR). Twenty-one patients with MCTR and thirty-seven age and sex matched controls were enrolled in the study. Genotyping of XPC gene Lys939Gln polymorphism was carried out using polymerase chain reaction-(PCR-) restriction fragment length polymorphism (RFLP). The frequencies of the heterozygote genotype (Lys/Gln-AC) and homozygote genotype (Gln/Gln-CC) were significantly different in MCTR as compared to control group, respectively (52.4% versus 43.2%, = 0.049; 38.15% versus 16.2%, = 0.018). Homozygote variant (Gln/Gln) genotype was significantly associated with increased risk of MCTR (OR = 2.059; 95% CI: 1.097-3.863; = 0.018). Heterozygote variant (Lys/Gln) genotype was also highly significantly associated with increased risk of MCTR (OR = 1.489; 95% CI: 1.041-2.129; = 0.049). The variant allele C was found to be significantly associated with MCTR (OR = 1.481; 95% CI: 1.101-1.992; = 0.011). This study has demonstrated the association of XPC gene Lys939Gln polymorphism with MCTR, which is significantly associated with increased risk of MCTR

Aortic distensibility and coronary artery bypass graft patency

<p>Abstract</p> <p>Background</p> <p>Aortic distensibility is an elasticity index of the aorta, and reflects aortic stiffness. Coronary artery disease has been found to be substantially associated with increased aortic stiffness. In this study we aimed to retrospectively analyze the association of angiographically determined aortic distensibility with the patency rates of coronary bypass grafts</p> <p>Methods</p> <p>The study was conducted in the Cardiology department of the Applied Research Centre for Health of Uludağ University. The coronary angiograms of 53 consecutive coronary bypass patients were analysed retrospectively. Aortic distensibility was calculated using the formula: 2 × (change in aortic diameter)/(diastolic aortic diameter) × (change in aortic pressure). The number of stenosed and patent bypass grafts and the patient characteristics like age, risk factors were noted.</p> <p>Results</p> <p>There were 44 male (83%) and 9 female (17%) cases. Eighteen cases had only one saphenous vein grafting. The number of cases with two, three and four saphenous grafting were 18, 11 and 1; respectively. In the control angiograms the number of cases with one, two, three and four saphenous vein graft obstruction were 15 (31.3%), 7 (14.6%), 1 (2.1%) and 1 (2.1%) respectively. The aortic distensibility did not differ in cases with and without saphenous graft occlusion (p > 0.05). Also left internal mammary artery (LIMA) graft patency was not related to the distensibility of the aorta (p > 0.05). We also evaluated the data for cut-off values of 50 and 70 mmHg of pulse pressure and did not see any significant difference between the groups in terms of saphenous or LIMA grafts.</p> <p>Conclusion</p> <p>In this study we failed to show association of angiographically determined aortic distensibility with coronary bypass graft patency in consecutive 53 patients with coronary artery bypass graft surgery (CABG).</p

Exposure to Perchlorate in Lactating Women and Its Associations With Newborn Thyroid Stimulating Hormone

Background: Perchlorate, thiocyanate, and nitrate can block iodide transport at the sodium iodide symporter (NIS) and this can subsequently lead to decreased thyroid hormone production and hypothyroidism. NIS inhibitor exposure has been shown to reduce iodide uptake and thyroid hormone levels; therefore we hypothesized that maternal NIS inhibitor exposure will influence both maternal and newborn thyroid function.Methods: Spot urine samples were collected from 185 lactating mothers and evaluated for perchlorate, thiocyanate, and nitrate concentrations. Blood and colostrum samples were collected from the same participants in the first 48 h after delivery. Thyroid hormones and thyroid-related antibodies (TSH, fT3, fT4, anti-TPO, anti-Tg) were analyzed in maternal blood and perchlorate was analyzed in colostrum. Also, spot blood samples were collected from newborns (n = 185) between 48 and 72 postpartum hours for TSH measurement. Correlation analysis was performed to assess the effect of NIS inhibitors on thyroid hormone levels of lactating mothers and their newborns in their first 48 postpartum hours.Results: The medians of maternal urinary perchlorate (4.00 μg/g creatinine), maternal urinary thiocyanate (403 μg/g creatinine), and maternal urinary nitrate (49,117 μg/g creatinine) were determined. Higher concentrations of all three urinary NIS inhibitors (μg/g creatinine) at their 75th percentile levels were significantly correlated with newborn TSH (r = 0.21, p &lt; 0.001). Median colostrum perchlorate level concentration of all 185 participants was 2.30 μg/L. Colostrum perchlorate was not significantly correlated with newborn TSH (p &gt; 0.05); however, there was a significant correlation between colostrum perchlorate level and maternal TSH (r = 0.21, p &lt; 0.01). Similarly, there was a significant positive association between colostrum perchlorate and maternal urinary creatinine adjusted perchlorate (r = 0.32, p &lt; 0.001).Conclusion: NIS inhibitors are ubiquitous in lactating women in Turkey and are associated with increased TSH levels in newborns, thus signifying for the first time that co-exposure to maternal NIS inhibitors can have a negative effect on the newborn thyroid function

Congenital Diarrhea and Cholestatic Liver Disease: Phenotypic Spectrum Associated with MYO5B Mutations

Myosin Vb (MYO5B) is a motor protein that facilitates protein trafficking and recycling in polarized cells by RAB11- and RAB8-dependent mechanisms. Biallelic MYO5B mutations are identified in the majority of patients with microvillus inclusion disease (MVID). MVID is an intractable diarrhea of infantile onset with characteristic histopathologic findings that requires life-long parenteral nutrition or intestinal transplantation. A large number of such patients eventually develop cholestatic liver disease. Bi-allelic MYO5B mutations are also identified in a subset of patients with predominant early-onset cholestatic liver disease. We present here the compilation of 114 patients with disease-causing MYO5B genotypes, including 44 novel patients as well as 35 novel MYO5B mutations, and an analysis of MYO5B mutations with regard to functional consequences. Our data support the concept that (1) a complete lack of MYO5B protein or early MYO5B truncation causes predominant intestinal disease (MYO5B-MVID), (2) the expression of full-length mutant MYO5B proteins with residual function causes predominant cholestatic liver disease (MYO5B-PFIC), and (3) the expression of mutant MYO5B proteins without residual function causes both intestinal and hepatic disease (MYO5B-MIXED). Genotype-phenotype data are deposited in the existing open MYO5B database in order to improve disease diagnosis, prognosis, and genetic counseling.This research was funded by Jubiläumsfonds der Österreichischen Nationalbank, grant no.16678 (to A.R.J.), grant no. 18019 (to G.-F.V.) and Tiroler Wissenschaftsfonds, grant No. 0404/2386 (toG.-F.V.).info:eu-repo/semantics/publishedVersio