Search

The aim of this study is to determine the thermal comfort conditions of workers in the industry and to provide measures for the effects of cold and heat. The measurements were carried out in accordance with ISO 7726 standard at 123 points between February 2016 and October in 9 enterprises operating in this scope in the Kocaeli region. The evaluations are divided into three main groups; normal, cold and hot environments. PMV, IREQ and WBGT methods were used to evaluate these environments, respectively. A special order has been followed in the use of the methods. In addition, questionnaires were used to determine the sociodemographic characteristics of the employees and their complaints and suggestions related to the environment. As a result of the measurements made, the IREQ value at 20 points was lower than the suit insulation value. At 10 points, the WBGT value exceeded the reference value. At 36 points, the temperature was very close to the WBGT limit value. According to the surveys, it was observed that the employees were generally disturbed by the lack of ventilation, work clothes and the effect of draft (air flow).

In this study, a proton exchange membrane fuel cell operating at low temperatures with a single channel is modeled. The prepared model has been compared with experimental data and its accuracy has been proved. Using this model, the impact of the change of the channel width on the cell performance with the channel height being constant and the change of the channel geometry with the channel cross-sectional area being constant was investigated. It has been found that the enlargement of the area where the reactant contacts the diffusion layer provides an increase in performance. However, when working at low voltages, it has been observed that increasing concentration losses decrease with increasing base angle and channel width.

Amaç: Bu çalışmanın amacı, 2016-2017 Sezonunda Türkiye Futbol Süper Liginde atılan ilk gollerin maç sonucuna etkisini göstermek ve gollerin analiziyle elde edilen sonuçlarla antrenörlere maç stratejilerini geliştirmede bilimsel veriler sunabilmektir. Materyal ve Yöntem: Bu araştırmanın örneklemini Türkiye Futbol Süper Liginde mücadele eden 18 futbol takımı oluştururken 2016-2017 sezonunda bu takımların oynadığı 306 maç ve bu maçlarda atılan 828 gol analiz edilmiştir. Çalışmada gözlem ve notasyonel analiz ile bilgisayar yardımlı maç analiz yöntemi kullanılmıştır. Analiz edilecek her bir kriter için ayrı bir gözlem formu oluşturulmuştur. 828 gol incelenirken ilk golleri oluşturan hücum biçimleri, hücum yönleri, vuruş alanları ve maçlarda atılan ilk gollerin maç sonucuna nasıl etki ettiği analiz edilmiştir. Bulgular: Yapılan analizler neticesinde ilk gol ile maçı galip olarak tamamlamak arasında pozitif yönde anlamlı bir ilişki tespit edilmiştir (p

BackgroundHemodynamic stress, conditioned by the morphology of the surrounding vasculature, plays an important role in aneurysm formation. Our goal was to identify image-based location-specific parameters that are associated with posterior communicating artery (PCoA) aneurysms.MethodsThree-dimensional morphological parameters obtained from CT angiography or digital subtraction angiography from 187 patients with unilateral PCoA aneurysms, diagnosed at the Brigham and Women’s Hospital and Massachusetts General Hospital between 1990 and 2016, were evaluated. In order to control for genetic and clinical risk factors, we chose the contralateral unaffected PCoA as a control group. We examined diameters and angles of the surrounding parent and daughter vessels. Univariable and multivariable statistical analyses were performed to determine statistical significance. Sensitivity analyses with small aneurysms (≤5 mm) only and an unmatched analysis of 432 PCoA aneurysms and 197 control patients without PCoA aneurysms were also performed.ResultsIn a multivariable conditional logistic regression model we showed that smaller diameter size ratio (OR 1.45×10−5, 95% CI 1.12×10−7 to 1.88×10−3) and larger daughter-daughter angle (OR 1.04, 95% CI 1.02 to 1.07) were significantly associated with PCoA aneurysm presence after correcting for other variables. In subgroup analyses of small aneurysms (≤5 mm) and in an unmatched analysis the significance and direction of these results were preserved.ConclusionsLarger daughter-daughter angles and smaller diameter size ratio are significantly associated with the presence of PCoA aneurysms. These simple parameters can be utilized to guide the risk assessment for the formation of PCoA aneurysms in high risk patients.

Fuel cells are promising alternative energy converters in terms of preventing pollution, efficiency, and noise. Direct borohydride fuel cells (DBFCs) which are defined as a sub-class of polymer electrolyte membrane fuel cells (PEMFCs) and direct liquid fuel cells (DLFC) have increased attention recently since they offer a solution for hydrogen storage problem. However, the commercialization of DBFC is hindered by the need of high platinum loadings. Therefore, reducing the platinum content is crucial to develop cost-effective DBFC without compromising performance. This research focuses on the effects of operational parameters on the DBFC performance with low level Pt/C catalyst loading (anode: 0.32 mg/cm(2), cathode: 0.36 mg/cm(2)). The gas diffusion electrode was prepared by spray-coating technique. The peak power density of 19.95 mW/cm(2) was obtained at 80 degrees C when 1 mL/ min was used as a flow rate of fuel. (c) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Intake port geometry is the most significant parameter for air supply of engines into combustion space. Especially because only air is supplied into combustion spaces of diesel engines and the fuel is sprayed over the air, intake port geometry should form a specific horizontal turbulence ratio in formation of fuel-air mixture. In this study, the impact of cylinder heads of intake port of a single cylinder compression ignition engine produced with 3 different geometries on performance and emissions of the engine was analysed experimentally. Additionally, the impact of intake port geometry produced with old and new moulds on 3 different geometries was researched. As a result of the study; power, torque, specific fuel consumption, exhaust gas temperatures, intake air flow and soot emission were measured. It was found out that the different intake port designs had impact on performance parameters, specific fuel consumption and soot emission following the study. Moreover, it was shown that the change of intake port didn’t have any impact on the flow of the air intake in low speed. It was observed that the cylinder heads produced with old and new mould cores had a significant impact. It is predicted that the main reason for the poor performance of the port geometry, which is called Y-type and creates a wider auger around the intake valve, may be due to the low turbulence intensity it creates in the cylinder. X and Z type ports gave better results by about 15% in power and torque values. Z type intake port gave the best performance in terms of exhaust gas temperature and soot emission.

Objectives: The pathogenesis of intracranial aneurysms is multifactorial and includes genetic, environmental, and anatomic influences. We aimed to identify image-based morphological parameters that were associated with middle cerebral artery (MCA) bifurcation aneurysms. Materials and methods: We evaluated three-dimensional morphological parameters obtained from CT angiography (CTA) or digital subtraction angiography (DSA) from 317 patients with unilateral MCA bifurcation aneurysms diagnosed at the Brigham and Women's Hospital and Massachusetts General Hospital between 1990 and 2016. We chose the contralateral unaffected MCA bifurcation as the control group, in order to control for genetic and environmental risk factors. Diameters and angles of surrounding parent and daughter vessels of 634 MCAs were examined. Results: Univariable and multivariable statistical analyses were performed to determine statistical significance. Sensitivity analyses with smaller (≤ 3 mm) aneurysms only and with angles excluded, were also performed. In a multivariable conditional logistic regression model we showed that smaller diameter size ratio (OR 0.0004, 95% CI 0.0001–0.15), larger daughter-daughter angles (OR 1.08, 95% CI 1.06–1.11) and larger parent-daughter angle ratios (OR 4.24, 95% CI 1.77–10.16) were significantly associated with MCA aneurysm presence after correcting for other variables. In order to account for possible changes to the vasculature by the aneurysm, a subgroup analysis of small aneurysms (≤ 3 mm) was performed and showed that the results were similar. Conclusions: Easily measurable morphological parameters of the surrounding vasculature of the MCA may provide objective metrics to assess MCA aneurysm formation risk in high-risk patients.

We present a cohort of patients with anterior communicating artery (ACoA) aneurysms to investigate morphological characteristics and clinical factors associated with rupture of the aneurysms. 505 patients with ACoA aneurysms were identified at the Brigham and Women’s Hospital and Massachusetts General Hospital between 1990 and 2016, with available CT angiography (CTA). Three-dimensional (3D) reconstructions were performed to evaluate aneurysmal morphologic features, including location, projection, irregularity, the presence of daughter dome, height, height/width ratio, and relationships between surrounding vessels. Patient risk factors assessed included patient age, sex, tobacco use, alcohol use, and family history of aneurysms and aneurysmal subarachnoid hemorrhage. Logistic regression was used to build a predictive ACoA score for rupture. Morphologic features associated with ruptured ACoA aneurysms were the presence of a daughter dome (OR 21.4, 95% CI 10.6–43.1), smaller neck diameter (OR 0.55, 95% CI 0.42–0.71), larger aspect ratio (OR 3.57, 95% CI 2.05–6.24), larger flow angle (OR 1.03, 95% CI 1.02–1.05), and smaller ipsilateral A2-ACoA angle (OR 0.98, 95% CI 0.97–1.00). Tobacco use was predominantly associated with morphological factors intrinsic to the aneurysm that were associated with rupture while younger age was also associated with morphologic features extrinsic to the aneurysm that were associated with rupture. The ACoA score had good predictive capacity for rupture with AUC = 0.92 using the 0.632 bootstrap cross-validation for correction of overfitting bias. Ruptured ACoA aneurysms were associated with morphological features that are simple to assess using a simple scoring system. Tobacco use and younger age were predominantly associated with intrinsic and extrinsic morphological features characteristic of rupture, respectively.

Morphological factors of intracranial aneurysms and the surrounding vasculature could affect aneurysm rupture risk in a location specific manner. Our goal was to identify image-based morphological parameters that correlated with ruptured basilar tip aneurysms. Three-dimensional morphological parameters obtained from CT-angiography (CTA) or digital subtraction angiography (DSA) from 200 patients with basilar tip aneurysms diagnosed at the Brigham and Women’s Hospital and Massachusetts General Hospital between 1990 and 2016 were evaluated. We examined aneurysm wall irregularity, the presence of daughter domes, hypoplastic, aplastic or fetal PCoAs, vertebral dominance, maximum height, perpendicular height, width, neck diameter, aspect and size ratio, height/width ratio, and diameters and angles of surrounding parent and daughter vessels. Univariable and multivariable statistical analyses were performed to determine statistical significance. In multivariable analysis, presence of a daughter dome, aspect ratio, and larger flow angle were significantly associated with rupture status. We also introduced two new variables, diameter size ratio and parent-daughter angle ratio, which were both significantly inversely associated with ruptured basilar tip aneurysms. Notably, multivariable analyses also showed that larger diameter size ratio was associated with higher Hunt-Hess score while smaller flow angle was associated with higher Fisher grade. These easily measurable parameters, including a new parameter that is unlikely to be affected by the formation of the aneurysm, could aid in screening strategies in high-risk patients with basilar tip aneurysms. One should note, however, that the changes in parameters related to aneurysm morphology may be secondary to aneurysm rupture rather than causal.

Determination of the wind energy potential is achieved by point measurement at the place. MERRA software which is generated by NASA provides the point data values. The point data with using Windographer software gives theoretically potential energy of wind turbines in a short time. In this study, the Kocaeli University campus selected a point, where the wind turbines are planned to be implemented. The obtained output power from wind energy will be examined. MERRA software and Windographer software are being used during this energy’s production study. The wind speed and direction analysis within 1 h of resolution is being performed at some points by using MERRA program. Windographer automatically defines wind resource data such as wind speed, standard deviation, vertical wind speed, direction, temperature, pressure, and relative humidity. Within the 4 point coordinates properly identified by the software, point “B” was selected. The annual wind data of the point “B” was analyzed and the annual amount of energy was calculated. In this study, GE 1.7-100 wind turbine was used. The generated energy and turbine output power were calculated by the Windographer program.

Heart diseases are rapidly increasing worldwide and in our country. Thisincrease causes difficulties in the diagnosis processes of heart diseases. Consideringthese problems, the studies of engineering applications related to medicalscience give effective results in terms of solutions. By means of engineeringdevices and algorithms, positive contributions are made to medicalapplications. These contributions assist physicians especially in the diagnosisstages and speed up these processes. In this study, a new algorithm isdevelopped so that Atrial Fibrillation (AF), which is the most common type ofarrhythmia encountered, can be automatically detected at a high success rate.Electrocardiogram (ECG) data used in this study were obtained from physiobank ATMdatabase. 31 samples of Atrial Fibrillation Rhythm (AFR) and 31 samples ofNormal Sinus Rhythm (NSR) were obtained from this database. RR Interval (RRI)sequences being 12 hours long are used in the study. The change of the RRIsequences is an important parameter for AF. The RRI sequences are re-sampled usingsignal pre-processing techniques. The Discrete Wavelet Transform (DWT) was thenapplied to the resampled signals. In this way, feature extraction process isperformed and the wavelet energies of these signals are visually examined withboxplot. The wavelet energies of the RRI sequences are classified by the SupportVector Machine (SVM). Finally, AFR and NSR are successfully separated as 99.60%achievement., Kalp hastalıkları dünyagenelinde ve ülkemizde hızlı bir biçimde artmaktadır. Bu artış kalphastalıklarının tanı süreçlerinde zorlukların oluşmasına neden olmaktadır. Busorunlar düşünüldüğünde mühendislik uygulamalarının tıp bilimi ile ilgili olançalışmaları çözümler açısından etkili sonuçlar vermektedir. Mühendisliksayesinde geliştirilen cihazlar ve algoritmalar sayesinde tıp uygulamalarınaolumlu katkılar sağlanmaktadır. Bu uygulamalar özellikle hekimlere tanıaşamalarında yardımcı olmakta ve bu süreçleri hızlandırmaktadır. Bu çalışmadaen sık rastlanan aritmi çeşidi olarak karşımıza çıkan Atriyal Fibrilasyon’un(AF) otomatik olarak tespitinin yüksek başarı oranında yapılmasıtasarlanmıştır. Bu çalışmada kullanılan Elektrokardiyogram (EKG) verileri, PhsiyobankATM veritabanından elde edilmiştir. Bu veritabınından 31 adet AtriyalFibrilasyon Ritmi (AFR) ve 31 adet Normal Sinüs Ritmi (NSR) olan sinyalleralınmıştır. Bu sinyaller 12’şer saatlik uzunlukta olup çalışmada RR Aralıklarıdizileri kullanılmıştır. RRA dizilerinin değişimi AF için önemli bir parametreolarak karşımıza çıkmaktadır. Sinyal işleme teknikleri ile RR Aralıkları zamanekseninde yeniden örneklenmiştir. Ardından yeniden örneklenen sinyallere AyrıkDalgacık Dönüşümü (ADD) uygulanmıştır. Bu sayede özellik çıkarımı işlemiyapılmış ve bu sinyallerin dalgacık enerjileri boxplot ile görsel olarakincelenmiştir. RRA dizilerinin dalgacık enerjileri Destek Vektör Makinası (DVM)ile sınıflandırma işlemine tabi tutulmuş ve %99,60 oranında başarıyla AFR veNSR birbirinden ayrılmıştır.

OBJECTIVEAlthough meningiomas frequently involve the optic nerve, primary optic nerve sheath meningiomas (ONSMs) are rare, accounting for only 1% of all meningiomas. Given the high risk of vision loss with these tumors, surgical intervention is seldom considered, and radiation or observation is commonly applied. Here, the authors describe the visual outcomes for a series of patients who were treated with surgery aiming at maximal tumor resection and highlight their prognostic factors.METHODSThe authors retrospectively analyzed the data for 8 patients with intracanalicular ONSMs who had been surgically treated by the senior author (O.A.) between 1998 and 2016. Meningiomas extending into the optic canal from the intracranial cavity (i.e., clinoid, sphenoid wing, tuberculum sellae, diaphragma sellae) were excluded. Diagnosis was based on ophthalmological, radiological, and intraoperative findings, which were confirmed by the typical histological findings. Preoperative, postoperative, and follow-up visual assessments were performed by neuro-ophthalmologists in all cases.RESULTSThe patients included 7 females and 1 male. The mean age at diagnosis was 45.1 years (range 25.0–70.0 years). Mean duration of follow-up was 38.9 months (range 3.0–88.0 months). All patients reported visual complaints, and all had objective evidence of optic nerve dysfunction. Their evaluation included visual field, visual acuity, funduscopy, and retinal fiber thickness. Total resection was obtained in 4 cases. Comparing preoperative and postoperative visual function revealed that 4 patients had improvement at the last follow-up, 1 patient had stable vision, and 3 patients had decreased function but none had total vision loss. All patients with good preoperative visual acuity maintained this status following surgical treatment. There was no surgical mortality or infection. Operative complications included binocular diplopia in 4 patients, which remitted spontaneously.CONCLUSIONSSurgery can play a beneficial role in the primary treatment of ONSM, especially lesions located in the posterior third of the nerve. Total removal can be achieved with vision preservation or improvement, without major surgical complications, especially at early stages of the disease. Patients with good preoperative vision and CSF flow in the optic sheath have better chances of a favorable outcome than those with poor vision.

In this study, the relationship between the pressure drop on the channels due to the methanol flow and the geometry of the flow channels on the anode side of a direct methanol fuel cell (DMFC) has been investigated. Parallel type channels are used as flow channels. The active area of the fuel cell is 5 x 5 cm(2). The system consists of channels that are optimally placed in the active area, with channel widths and distance of the channels kept constant. Combinations of 1, 1.5, 2, 2.5, 3 mm measurements were used for flow channel width and distance between channels. The ratio of the area created by the prepared geometries to the active area (percentage of contact area) is defined as a new parameter. The main motivation of this study is to be able to determine the effect of the geometric measurements of the designed flow channels on the intra-channel pressure drop by statistical method. There was a statistically significant difference between the flow channel widths and the distance between the channels and the pressure. Among the selected parameters, the effect of the channel width on the pressure drop was highest but it had a statistically moderate relationship. However, there was no significant relationship between the distance between channels and the pressure drop. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

In this study, a techno-economic analysis of offgrid PV LED road lighting systems is made for Antalya province of Turkey. DIALux software is used for road lighting calculations and HOMER software is used in modelling, sizing, and optimization of the energy systems. Calculations are made to determine whether maximum or minimum pole spacing options for both twin-bracket central and opposite lighting arrangements provide the optimal system design for off-grid PV LED road lighting systems under the M3 lighting class in Antalya. The techno-economic analysis of the energy system in case of dimming LED luminaires after midnight is made. Since the payback periods of the systems are found to be above the system lifetime (20 years) with and without dimming, in addition to the current case, future projections, in which electricity unit prices increase and cost of PV system component and battery costs decrease, are examined.

While Coronavirus disease-2019 (COVID-19) affects the whole world, most affected group is geriatric individuals. There is a need for strategies for geriatric individuals returning to society and their social life. The aim of this study is to investigate the effect of an 8-week home-based Pulmonary Rehabilitation program on quality of life, depression, anxiety and functional capacity in geriatric individuals with COVID-19. Twenty-five patients were included in this prospective study. Patients over 65 years of age with COVID-19 were evaluated. Physical capacity with the 6-minute walking test (6MWT), dyspnea status with the Medical Research Council Dyspnea Scale, quality of life with the Short Form-36 (SF-36), depression and anxiety with the Hospital Anxiety and Depression Scale were evaluated. The mean age of the patients included in the study was 68.9 ± 6.4 years. 56% of the patients were men and 44% were women. When pre-treatment and post-treatment values were compared, a significant improvement was found in the 6MWT, dyspnea scores, SF-36 and all subgroups, anxiety and depression scores (p, Coronavirüs hastalığı-2019 (COVID-19) tüm dünyayı etkilerken en çok etkilenen grup geriatrik bireylerdir. Geriatrik bireylerin topluma ve sosyal yaşamlarına dönmeleri için bazı stratejilere ihtiyaç vardır. Bu çalışmanın amacı, COVID-19'lu geriatrik bireylerde 8 haftalık ev temelli Pulmoner Rehabilitasyon programının yaşam kalitesi, depresyon, anksiyete ve fonksiyonel kapasite üzerine etkisini araştırmaktır. Bu prospektif çalışmaya 25 hasta dahil edildi. COVID-19 geçirmiş 65 yaş üstü hastalar değerlendirildi. Fiziksel kapasite 6 dakikalık yürüme testi (6DYT) ile, dispne durumlar Medical Research Council Dispne Skalası ile, yaşam kalitesi Kısa Form-36 (KF-36) ile, depresyon ve anksiyete durumları ise Hastane Anksiyete ve Depresyon Ölçeği ile değerlendirildi. Çalışmaya dahil edilen hastaların ortalama yaşı 68.9 ± 6.4 idi. Hastaların% 56'sı erkek,% 44'ü kadındı. Tedavi öncesi ve tedavi sonrası değerler karşılaştırıldığında 6DYT, dispne skorları, SF-36, anksiyete ve depresyon skorlarında anlamlı iyileşme saptandı (p