Determination of Optimum Compression Ratio: A Tribological Aspect

Internal combustion engines are the primary energy conversion machines both in industry and transportation. Modern technologies are being implemented to engines to fulfill today's low fuel consumption demand. Friction energy consumed by the rubbing parts of the engines are becoming an important parameter for higher fuel efficiency. Rate of friction loss is primarily affected by sliding speed and the load acting upon rubbing surfaces. Compression ratio is the main parameter that increases the peak cylinder pressure and hence normal load on components. Aim of this study is to investigate the effect of compression ratio on total friction loss of a diesel engine. A variable compression ratio diesel engine was operated at four different compression ratios which were "12.96", "15:59", "18:03", "20:17". Brake power and speed was kept constant at predefined value while measuring the in- cylinder pressure. Friction mean effective pressure ( FMEP ) data were obtained from the in cylinder pressure curves for each compression ratio. Ratio of friction power to indicated power of the engine was increased from 22.83% to 37.06% with varying compression ratio from 12.96 to 20:17. Considering the thermal efficiency , FMEP and maximum in- cylinder pressure optimum compression ratio interval of the test engine was determined as 18.8 ÷ 19.6

Water Needs of Black Locust Robinia pseudoacacia L. in the First Three Years of Growing in the Reclamation Plantings in Poland

Black locust, considered an ornamental plant, is often used in the soil reclamation process, because it enriches the soil with nitrogen. High seedling survival rate in the first stage of reclamation depends mainly on sufficient water conditions controlled by irrigation, which in turn requires determining the plant's water needs. The aim of the research was the estimation of black locust water needs during the first three years of growing. Potential evapotranspiration, as the measure of the plant water needs, was calculated in the study. The formula of Blaney-Criddle, modified by Zakowicz for Polish conditions, by using the adjusted crop coefficients, was applied. The calculations were carried out for the growing period (April-October) during the thirty years period (1981-2010), for five agro-climatic regions of PolandVytauto Didžiojo universitetasŽemės ūkio akademij

EUROASPIRE III: A comparison between Turkey and Europe [EUROASPIRE III: Türkiye ile Avrupa'nin karşilaştirilmasi]

PubMed ID: 20675993Objectives: The EUROASPIRE III survey was conducted in 2006-2007 in 22 countries in Europe (76 centers) to describe risk factors, lifestyle and therapeutic management of patients with coronary heart disease (CHD), compliance with current guidelines, and to document changes over time. This study aimed to assess the results of the EUROASPIRE III survey in terms of differences between Turkey and other European countries. Study design: The results of the EUROASPIRE III survey were compared with those of 17 centers from Turkey. Consecutive patients with a diagnosis of CHD (669 medical records, %23.8 women) were identified retrospectively, of which 338 patients (50.5%) were followed-up, interviewed, and examined at least six months after the index event (acute coronary syndrome or interventional procedure). Results: Compared to the EUROASPIRE III data, recordings from Turkey's centers at discharge on classical risk factors did not exhibit remarkable differences; however, data on weight, height, waist circumference, lipid profile, glucose, and HbA1c measurements were more incomplete. In comparison to Europe population, the most important differences were observed in the higher rates of the following: young patients with myocardial infarction (<50 years, 20% vs. 12.7%), persistence in smoking (23.1% vs. 17.2%), immobility, low HDL-cholesterol (50.2% vs. 36.7%), insufficient follow-up by physicians after the index event (12% vs. 2.2%-except Turkey), and insufficient patient education. Conclusion: The data from the Turkey arm of the survey show that efforts for cardiovascular disease prevention fall short of the targets, similar to Europe