T HE diaphragm stethoscope is usually credited to R. C. M. Bowles, an engineer of Suffolk County, Massachusetts, who was issued Letters Patent No. 526-802, October 2, 1894. Previous instruments had employed diaphragms but they were carefully recessed to avoid contact with the skin. Bowles concluded from his studies that sound conveyed by such instruments resulted from vibrations transmitted fro...

Background: Cryopreservation of ovaries is an important technique in assisted reproduction technology. Physical forces like hydrostatic pressure have a pivotal role in reproduction systems. Due to changes in intrafollicular pressure during ovulatory process, this study designed to examine the effects of hydrostatic pressure on oocyte maturation and cell death in cumulus cells from cryopreserved...

composite pressure vessel cng made of epoxy – carbon material with nonmetal liner is 60% lighter than aluminum vessel under the same conditions. one of the important parameters in the pressure vessels design is their resistance against impact and prevention of explosion. in this paper, the effects of low velocity impact on composite pressure vessel are investigated using fe analysis. the vessel...

background: in previous studies, the neuroprotective effect of 17&beta-estradiol; in diffuse traumatic brain injury has been shown. this study used ici 182,780, a non-selective estrogen receptor antagonist, to test the hypothesis that the neuroprotective effect of 17&beta-estradiol; in traumatic brain injury is mediated by the estrogen receptors. methods: the ovariectomized rats were divided in...

one of the bellows producing method is hydroforming process .whereas some factor of hydroforming process specially internal pressure affects on final characteristics produced bellows such as bursting, wrinkling and wall thickness distribution. in this paper the effect of internal pressure factor in final quality of produced bellows will be investigated. in simulation of process, abaqus/explicit...

co2/ch4 gas separation is a very important applicatable process in upgrading the natural gas and landfil gas recovery. in this work, to investigate the membrane separation process performance, the gas permeation results andco2/ch4 separation characteristics of different prepared membranes (via blending different molecular weights of polyethylene glycol (peg) as a modifier with acrylonitrile-but...

Joule-Thomson cooling systems are used in refrigeration processes such as cryogenic gas liquefaction. Although extensive studies have been carried out by researchers, most of them include cryogenic heat exchangers and their associated fields. In the current study, an attempt was made to indicate the effect of using inappropriate operational conditions in a cryogenic Joule-Thomson cooling system...

Objective: Type 2 diabetes mellitus (DM-2) is a chronic and progressive metabolic disorder known as a serious threatening condition in the individual and society. Type 2 diabetes mellitus is known as the major cause of cardiovascular diseases (CVD). Contradictory evidences about the effect of omega-3 fatty acids on CVD risk factors, particularly hypertension. The aim of this study was to determ...