Ali Öz

This study investigates the potential relationship between occupational health and safety (OHS) standards in academic laboratories and the quality of scientific research output. Using a dataset of 102 peer-reviewed publications extracted from the Scopus database between 1987 and 2025, this study conducted a bibliometric analysis to explore trends, thematic patterns, institutional contributions, and citation impacts in the context of applied sciences. Rather than analyzing OHS as a research topic, this paper adopts a structural perspective: considering how the presence or absence of OHS practices may influence research productivity, visibility, and overall impact. The results reveal a concentration of high-impact publications originating from institutions in countries with mature safety regulations and well-established research infrastructures. The study concludes by framing OHS not just as a regulatory concern but as a potentially overlooked driver of academic excellence, urging further integration of safety culture into research evaluation frameworks.

Çalışmada, NUTS2 TR-61 (Batı Akdeniz) Bölgesi’nde yer alan ve 1.000 kişi başına otomobil sayısı bakımından sırasıyla 5. ve 9. sırada yer alan Isparta ve Burdur illerinde ikamet eden otomobil satın alma isteğinde olan hanehalklarının otomobil yakıt türü tercihlerini etkileyen faktörler incelenmiştir. Bu bağlamda, 307 haneden toplanan veriler Multinomial Probit (MNP) modeli ile analiz edilmiştir. Sonuçlar, fosil yakıtlı araç tercih edenlerin oranının en yüksek olduğunu, bunu elektrikli ve hibrit araç tercih edenlerin izlediğini göstermektedir. Çalışmada, gelir düzeyi ve CO2 salınımı hassasiyetinin elektrikli otomobil sahipliğini olumlu yönde etkilediği; elektrikli otomobillerin hanehalkları tarafından genellikle şehir-içi kullanım için ikinci otomobil olarak tercih edildiği ve dolayısıyla otomobilin kadın sahipliğine atfedildiği, elektrikli otomobillerin ön lisans ve lisans eğitimine sahip kişilerce daha fazla tercih edildiği; hanehalkı büyüklüğünün elektrikli otomobil tercihini pozitif etkilediği belirlenirken hane yakınında şarj istasyonunun varlığı ve araç performansına verilen önem elektrikli otomobil tercihini negatif etkilediği belirlenmiştir. Eğitim düzeyinin lise ve altı olması ise hibrit otomobil tercihini negatif etkilemektedir. Hanehalklarının elektrikli ve hibrit otomobiller hakkındaki bilgi düzeyinin arttırılması, şarj istasyonu sayısının yanında ülke genelinde ve tüm rotalar arasında dağılımının düzenlenmesi ve servis ağı, menzil sorunu, yanma vb. gibi teknik sorunların çözülmesi bu otomobillerin tercih edilme oranını arttıracak politikalar arasında yer almaktadır.

Bu çalışmada, piston oyukları düşük ısı iletim katsayısına sahip bir malzemeyle kaplanmış direkt püskürtmeli bir dizel motorun yanma odası ısı transfer karakteristikleri incelenmiştir. Testler, sabit devirde ve dört farklı motor yükünde yapılmıştır. Piston oyukları plazma sprey yöntemiyle itriya stabilize zirkonya maddesi ile kaplanmıştır. Isı taşınım katsayısı hesaplanmasında dizel motorlar için literatürde sıklıkla kullanılan Hohenberg, Eichelberg ve Woschni modelleri esas alınmıştır. Başlıca ısı geçişi parametreleri olarak ısı transfer katsayısı, ısı akısı, birim krank açısında toplam ısı çıkışı ve ısı geçişi ele alınmıştır. Yapılan çalışma sonucunda; artan motor yükü ve piston kaplama uygulamasıyla birlikte yanma odasında ısı taşınım katsayısının, ısı akısının, toplam ısı çıkışının ve ısı akısının önemli oranda arttığı gözlenmiştir. Sıkıştırma periyodunda, Hohenberg modelinin genel olarak daha yüksek ısı transfer oranı değerleri verdiği buna karşılık Woschni modelinin daha düşük ısı transfer oranı değerleri verdiği tespit edilmiştir. Isı geçişi parametreleri düşük yükte Woschni modeliyle en düşük değerdeyken en yüksek yükte maksimum değerlere ulaşmıştır. En yüksek yükte her iki motorda da toplam ısı çıkışı değerleri kullanılan tüm modellerle birbirine oldukça yakın bulunmuştur.

The selection of refrigerant is one of the most important parameters when designing a cooling system. Hydrocarbon refrigerants have low primary energy requirements for effective cooling capacity and favourable thermodynamic properties that reduce both direct and indirect greenhouse gas emissions. In this study, a comparative performance and environmental analysis of the vapor compression refrigeration cycle using C-Pentane as the refrigerant was performed. The cooling performance and environmental effect of C-Pentane has been compared with the cooling performance and environmental effect of R134A, R407C and R404A refrigerants in the cooling system. During the analysis, the cooling system was examined under different operating conditions. The highest coefficient of performance (COP) value in the analysis was 6.485 for the refrigeration cycle using C-Pentane, and this value was obtained at 0 oC evaporator temperature and 25 oC condenser temperature operating condition. According to the Life Cycle Climate Performance (LCCP) analysis for refrigerants, the lowest total emission value belongs to C-Pentane. Direct Emission (DE) value and indirect emission (IE) value of C-Pentane are 57.5 kgCO2 and 24928.04 kgCO2, respectively.

In this study, the effect of weather conditions on on-street parking variables is examined. In this context, data sets consist of 17 variables such as parking capacity, employee personnel, off-duty personnel, turn-over rate, first-hour parking price, daily parking price, number of transactions, number of cash transactions, average cash parking duration, 0-15 min parking duration, average parking duration, number of subscription, parking subscription price, daily transactions of subscription, subscription parking duration and income on the on-street parking spaces in the Anatolian Side of Istanbul for two years (2017-2018). In this study, turnover rate, parking duration, cash parking duration, and parking income variables are investigated by multiple regression analysis with dummy variables. Daily general weather data during this period are classified into 11 categories as sunny, cloudy, partly cloudy, light rain, rain, short-term heavy rainfall, heavy rainfall, light snow, light snowfall, snow, and a heavy snowstorm- as dummy variables. Based on the estimation results, it is found that both sunny and light snow + light snowfall + snow + heavy snowstorm weather variables decrease parking duration by 0.528 and 1.293 min, respectively. Moreover, results also indicated that the same variables increase cash parking duration by 1.21 and 3.29 min, respectively. Both sunny and cloudy + partly cloudy weather variables increase parking income by 719 TL and 580 TL, respectively. Light snow + light snowfall + snow + heavy snowstorm weather variable decreases parking income by 1143 TL.

In the rapidly developing automotive technology, the efforts to achieve high performance with less fuel consumption is one of the most important issues today. The purpose of the supercharged systems developed for this reason is to send more air into the cylinder. For high engine performance and low exhaust emission values, the intake air temperature, which is heated in the turbo-compressor and has the oxygen concentration (the amount of oxygen in the unit air) decreased, must be kept at certain levels. Therefore, the heated air between the compressor outlet and the cylinder inlet must be cooled. In this study, different types of intercoolers were designed and analyzed with the help of ANSYS Fluent (CFD) program, and optimum conditions were tried to be obtained by comparing them with each other.

The friction force in mechanical systems not only reduces their efficiency but also causes wear in the machine components, resulting in financial losses. As in every sector, in agricultural production, the problem of abrasion, particularly in soil tillage, is extremely important. Studies have been conducted examining the different methods for minimizing wear on tillage machinery. In this study, the cultivator blades of a boron-alloyed 30MnB5 steel substrate were coated with WC–10Co–4Cr ceramic powder by way of the Diamond Jet high-velocity oxygen-fuel (DJ-HVOF) technique. The microstructure of the sample and its wear properties under field conditions were then investigated. The microstructure, porosity, hardness, surface roughness and wear properties of the samples were revealed. The coating was observed to be well bonded, both mechanically and metallurgically, and the hardness of the coating was three times higher than that of the uncoated substrate material. In the field trials, the wear was found to be six times lower due to the hardness of the WC–10Co–4Cr coating and the hard carbide phases in its microstructure. As a result, the HVOF coating was shown to minimize wear, which is a big problem in tillage machinery. This can extend the economic life of machinery and make agricultural production more efficient.

This study was carried out to investigate the micro and chemical structure of particulate matter and nitrogen oxide from motor vehicle exhaust fumes. In this context, particulate matter microstructure was determined with the help of scanning electron microscope; elements such as C, O, N, F, Na, Mg, Br, Al, Si, Hg, S, Pb, Cl, Cd, K, Ca, Ba, Ti, V, Mn, Fe, Ni, V and Zn which constitute the source of pollution were determined by energy dispersive spectrometer; nitrogen oxide compounds were determined with X-ray diffraction spectrometer; and photonic properties were determined by means of photoluminescence spectrophotometer. The data obtained in this study provide important source information to understand the effects of exhaust fume on environmental pollution.