Effects of operation temperature and reactant gas humidity levels on performance of PEM fuel cells

WOS: 000371948400092In this study, the effects of operation conditions on the performance of a polymer electrolyte membrane fuel cell are investigated and the results are presented together with a comprehensive literature review on the related topics. The cells with 25 cm(2) active area are tested for different inlet gas humidification levels and inlet temperatures, operating temperatures and oxidant type. The cells are characterized by the performance curves together with the cell resistance measurements. The results indicate that the humidification of the inlet gases positively affect the cell performance. However, the improvement in the cell performance is higher when the cathode gas is humidified. In addition, the operating temperature and the inlet gas temperatures are found to be the most significant parameters. The cell performance tends to increase significantly with increasing the operating and inlet gas temperatures. The effect of the oxidant type is also considered and the cell tested with pure oxygen shows slightly higher performance. (C) 2016 Elsevier Ltd. All rights reserved

Rule-based Mamdani-type fuzzy modelling of thermal performance of fintube evaporator under frost conditions

Frost formation brings about insulating effects over the surface of a heat exchanger and thereby deteriorating total heat transfer of the heat exchanger. In this study, a fin-tube evaporator is modeled by making use of Rule-based Mamdani-Type Fuzzy (RBMTF) logic where total heat transfer, air inlet temperature of 2 °C to 7 °C and four different fluid speed groups (ua1=1; 1.44; 1.88 m s-1, ua2=2.32; 2.76 m s-1, ua3=3.2; 3.64 m s-1, ua4=4.08; 4.52; 4.96 m s-1) for the evaporator were taken into consideration. In the developed RBMTF system, outlet parameter UA was determined using inlet parameters Ta and ua. The RBMTF was trained and tested by using MATLAB® fuzzy logic toolbox. R2 (%) for the training data and test data were found to be 99.91%. With this study, it has been shown that RBMTF model can be reliably used in determination of a total heat transfer of a fin-tube evaporator

Rule-based Mamdani-type fuzzy modelling of thermal performance of fintube evaporator under frost conditions

Frost formation brings about insulating effects over the surface of a heat exchanger and thereby deteriorating total heat transfer of the heat exchanger. In this study, a fin-tube evaporator is modeled by making use of Rule-based Mamdani-Type Fuzzy (RBMTF) logic where total heat transfer, air inlet temperature of 2 °C to 7 °C and four different fluid speed groups (ua1=1; 1.44; 1.88 m s-1, ua2=2.32; 2.76 m s-1, ua3=3.2; 3.64 m s-1, ua4=4.08; 4.52; 4.96 m s-1) for the evaporator were taken into consideration. In the developed RBMTF system, outlet parameter UA was determined using inlet parameters Ta and ua. The RBMTF was trained and tested by using MATLAB® fuzzy logic toolbox. R2 (%) for the training data and test data were found to be 99.91%. With this study, it has been shown that RBMTF model can be reliably used in determination of a total heat transfer of a fin-tube evaporator

Evaluation Of Central Nervous System In Patients With Glycogen Storage Disease Type 1A

We aimed to evaluate structure and functions of central nervous system (CNS) in children with glycogen storage disease (GSD) type 1a. Neurological examination, psychometric tests, electroencephalography (EEG), magnetic resonance imaging (MRI), visual evoked potentials (VEP) and brainstem auditory evoked potentials (BAEP) were performed. The results were compared between patients with good and poor metabolic control and healthy children. Twenty-three patients with GSD type 1a were studied. Twelve patients were in poor metabolic control group and 11 patients in good metabolic control group. Five patients had intellectual disability, 10 had EEG abnormalities, seven had abnormal VEP and two had abnormal BAEP results. MRI was abnormal in five patients. There was significant correlation between the number of hypoglycemic attacks and MRI abnormalities. Central nervous system may be affected in GSD type 1a even in patients with normal neurologic examination. Accumulation of abnormal results in patients with poor metabolic control supports the importance of metabolic control in GSD type 1a.WoSScopu

Türkiye’ de Pediatrik Nötropenik Hasta İzlemi

Objective: Infection is a common complication in children with malignancies. There is no consistent guidance for environmental infection control and isolation precautions for neutropenic patients (NP). There are differences between centers. the aim of this questionnaire study was to determine these differences in Turkey. Material and Methods: A multicenter-descriptive questionnaire was conducted on 36 centers from different geografical locations of Turkey. Bone marrow transplantation units were excluded. Each center was contacted at least three-times. Questionnaire was answered by two different doctors from each center. Results: Thirty-six centers including 20 (55.5%) University Hospitals, 12 (%33.3) Research Hospitals, three (8.3%) State Hospital and one Private University Hospital participated in this survey. 94.3% of the centers had a bed capacity of 50 beds and over. Twenty-one (58.3%) centers had pediatric infection ward that followed febrile NP. All centers had an infection control committee. 25% (9/36) of the centers always followed pediatric neutropenic fever patients in a single room. 66.6% (24/36) of the centers had toilet in all patients’ room. the door features of patients’ room included mostly (94.1%, 32/34) manually opened door. Ten (27.7%) centers had hepa filter system, five of them had positive-negative pressure room. Thirteen (38.2%, 13/34) centers prefered hickmann catheter for accessing a patient’s central line. Training was given for catheteter care in all centers. Sixteen (44.4%) centers had determined policies about keeping toys in patient rooms. Visitor restrictions were performed in all centers. None of the centers allowed plants or flowers in hospital rooms. There was a neutropenic diet specific for pediatric NP provided in twenty-seven centers (75%). Conclusion: the prevention and control of infection contributes to the improvement of the prognosis of patients with hematological malignancies. Physicians must be aware of the infection risks and take precautions for infectious complications through the neutropenic period and standard protocols should be established and implemented for patients with hematological malignancies.Giriş: Maligniteli hastaların tedavi sürecindeki en önemli komplikasyonlardan biri enfeksiyonlardır. Nötropenik hastalarda enfeksiyon kontrolü ve izolasyon önlemleri için merkezden merkeze değişen farklı uygulamalar mevcuttur. Anket çalışmasının amacı Türkiye’deki bu farklılıkları ve ihtiyaçları belirlemektir. Gereç ve Yöntemler: Çok merkezli tanımlayıcı çalışmaya Türkiye’nin farklı coğrafik bölgelerinden pediatrik nötropenik hasta takip eden 36 merkez dahil edildi. Kemik iliği transplantasyon üniteleri çalışmaya alınmadı. Her merkezle en az üç kez iletişime geçildi. Anketi her merkezden iki doktor yanıtladı. Anket kişisel, genel hasta bakımı ve nötropenik hasta bakımını içeren 64 sorudan oluşmaktaydı. Bulgular: Çalışmaya katılan merkezlerin 20 (%55.5)’si üniversite hastanesi, 12 (%33.3)’si eğitim araştırma hastanesi, 3 (%8.3)’ ü devlet hastanesi ve bir tanesi de özel üniversite hastanesi idi. Merkezlerin %94.3’ünün yatak kapasitesi 50 yatak ve üzerinde idi. Yirmi bir (%58) merkezin çocuk enfeksiyon hastalıkları servisi mevcuttu. Tüm merkezlerin enfeksiyon kontrol komitesi vardı. Merkezlerin %25 (n= 9)‘inde nötropenik ateş (NPA) tanısı alan çocuk hastalar tek kişilik odalarda izleniyordu. Tüm odalarda tuvalet bulunan merkez sayısı 24 (%66.6) idi. Hasta odalarının büyük çoğunluğunda elle açılıp kapanır kapı (%94.1) ve musluk (%97.1) mevcuttu. on (%27.7) merkezin oda havalandırması için hepa-filtreli sistemi vardı. Beşinde negatif basınçlı oda mevcuttu. on üç merkezde kateter olarak hickman kateter tercih edilmişti. Tüm merkezlerde kateter bakımı için eğitim verilmekte idi. Hiçbir merkezde hasta ziyaretine ve hastane odasında bitki veya çiçek bulundurmaya izin verilmemekteydi. Merkezlerin %45.7’sinde hastanede oyuncak bulundurma ile ilgili hastane politikası vardı. Sonuç: Sonuç olarak, nötropenik hastaları enfeksiyondan korumak için hastanelerde çeşitli yaklaşımlar uygulanmaktadır. Rehberler belirlenip bu rehberler ışığında hastane koşulları düzenlenmeli ve nötropenik hasta izlemi yapılmalıdır

Pediatric Neutropenic Patients Care In Turkey

Objective: Infection is a common complication in children with malignancies. There is no consistent guidance for environmental infection control and isolation precautions for neutropenic patients (NP). There are differences between centers. The aim of this questionnaire study was to determine these differences in Turkey. Material and Methods: A multicenter-descriptive questionnaire was conducted on 36 centers from different geografical locations of Turkey. Bone marrow transplantation units were excluded. Each center was contacted at least three-times. Questionnaire was answered by two different doctors from each center. Results: Thirty-six centers including 20 (55.5%) University Hospitals, 12 (%33.3) Research Hospitals, three (8.3%) State Hospital and one Private University Hospital participated in this survey. 94.3% of the centers had a bed capacity of 50 beds and over. Twenty-one (58.3%) centers had pediatric infection ward that followed febrile NP. All centers had an infection control committee. 25% (9/36) of the centers always followed pediatric neutropenic fever patients in a single room. 66.6% (24/36) of the centers had toilet in all patients' room. The door features of patients' room included mostly (94.1%, 32/34) manually opened door. Ten (27.7%) centers had hepa filter system, five of them had positive-negative pressure room. Thirteen (38.2%, 13/34) centers prefered hickmann catheter for accessing a patient's central line. Training was given for catheteter care in all centers. Sixteen (44.4%) centers had determined policies about keeping toys in patient rooms. Visitor restrictions were performed in all centers. None of the centers allowed plants or flowers in hospital rooms. There was a neutropenic diet specific for pediatric NP provided in twenty-seven centers (75%). Conclusion: The prevention and control of infection contributes to the improvement of the prognosis of patients with hematological malignancies. Physicians must be aware of the infection risks and take precautions for infectious complications through the neutropenic period and standard protocols should be established and implemented for patients with hematological malignancies.WoSScopu

Proceedings Of The 23Rd Paediatric Rheumatology European Society Congress: Part Two

PubMe