the paper studies optimization of shell-and-tube heat exchangers using the particle swarm optimization technique. a total cost function is formulated based on initial and annual operating costs of the heat exchangers. six variables – shell inside diameter, tube diameter, baffle spacing, baffle cut, number of tube passes and tube layouts (triangular or square) – are considered as the design para...

primary fallopian tube carcinoma is a rare tumor that histologically and clinically resembles epithelial ovarian cancer. here we introduce a case of tubal carcinoma in a postmenopausal woman. the diagnosis of primary fallopian tube carcinoma is rarely considered preoperatively and is usually first appreciated by the pathologist. because of low frequency of tubal carcinoma, there are few systemi...

background: with respect to physical relations in force and pressure, we hypothesized that the prevalence of traumatic tympanic membrane perforation in patients with a patulous eustachian tube is greater than normal, because in eustachian tube patency, the internal air pressure of the middle ear will not increase after compression, subsequent to trauma. therefore the force upon the tympanic mem...

.hot metal gas forming of tubes can be used in various industries such as automotive and aerospace industries. in this process tube is formed at elevated temperatures, by using gas instead of fluid pressure. lower required pressure and low power are its advantages in comparison to hydroforming process. in this paper, a hot metal gas bulging process of an aluminum alloy tube has been investigate...

a-56-year-old woman underwent carpal tunnel release surgery under general anesthesia. thirty minutes after extubation, the patient complained of chest discomfort with dyspnea. swelling of the neck and upper anterior chest was observed. computed tomography of the chest showed tracheal rupture at the brachiocephalic trunk level, and bronchoscopy demonstrated a 5 cm linear tracheal defect in the p...

chronic otitis media is a common disease which can lead to serious complications or even death. betterment of eustachian tube function is effective on results of operations. the main goal of this study was to determine the effect of eustachian tube function on outcome of graft in tympanoplasty or tympanomastoidectomy for chronic otitis media. we prospectively studied 126 patients who underwent ...

background and objective: the fallopian tube plays an essential role in tubal transportof both gametes and embryos and successful pregnancy. we assessed the histomorphological effect of smoking on the fallopian tubes in rats, in this study. patients and methods: twelve female rats were divided to two groups as subjects (n=7) and controls (n=5). they have been exposed to smoke four times daily f...

background & importance: iniencephaly is a rare cranio-cervical deformity. it belongs to neural tube defects. this disorder is characterized by a retroflexion of head, a very short neck, varying degrees of incomplete posterior closure of vertebrae and cervical and thoracic spinal synostosis. this malformation is associated with central nervous system and systemic malformations. most of patients...