this paper presents noise problems associated with the use of air-turbine drills in dental practice. two hundred and fifty dentists (male and female) were randomly selected from the faculty of dentistry as well as the dentists who worked private in tehran. the results indicated that the mean value of sound pressure level produced by the high-speed drills was 69.1 db. most of the energy from the...

Oxygen is an essential part of the most important metabolic pathways in aerobic organisms. Oxygen delivery is merely dependent on blood, rendering blood loss a devastating event. Traumatic pre-hospital liver bleeding is a major cause of early trauma deaths in human and animals, with no established therapeutic method yet. Increasing intra-abdominal pressure (IAP) has been shown to reduce liver b...

background: obesity has been associated with several co ‑ morbidities such as diabetes and increased mortality. in general, the use of medication promotes only a modest weight loss in the range of 2 to 10 kg, usually most effective during the first 6 months of therapy; however, studies have shown positive effects on other risk factors such as blood pressure and serum glucose levels, but there...

in this paper, a new combined power and refrigeration cycle is proposed, which combines the rankin power cycle and the ejector refrigeration cycle. this combined cycle produces both power output and refrigeration output simultaneously. this cycle is driven by the flue gas of gas turbines, industrial waste heats, solar energy and geothermal energy. an exergy analysis is performed to guide the th...

Overweight is an increasingly prevalent condition throughout the world. Current estimates, which are probably conservative, indicate that at least 500 000 000 people worldwide are overweight as defined by a body mass index (BMI) of between 25.0 and 29.9 and an additional 250 000 000 are obese with a BMI of 30.0 or higher.1 In the United States, recent data indicate that as much as 66% of the ad...

abstract background: previous studies have indicated an unspecific correlation between noise exposure and blood pressure disturbances. blood pressure disturbances could be caused by the environmental hazards such as noise exposure. the aim of this study is to analyze whether there is a relationship between noise exposure and hypertension. methods: atotal sample of 218 workers working in a small...

since knowledge on hydrodynamic torque of a butterfly valve is very important for butterfly valve design, its hydrodynamic torque is investigated in this paper. in reality, the investigation of the loss coefficient and torque from some experiments will take a long time and a lot of money. this paper presents a statistical study of the flow past the butterfly valve in a static analysis using com...