many serious accidents have happened in the world, in which systems have been large-scale and complex, and caused heavy damage and a social sense of instability. furthermore, advanced nations have almost finished public infrastructure and rushed into a maintenance period. since maintenance is more important than production and construction, then more maintenance for environmental considerations...

In this study, material and dynamic stress experiments are combined with finite element (FE) simulations to reveal the fracture mechanism of wheelset lifting apparatus, a structural design optimization scheme based on double-layer Kriging surrogate model is proposed. The apparatus first clarified through analysis macro/micro tests. Static strength modal analyses then performed perfect in terms ...

background: methadone is considered a long-acting opioid agonist which is widely used in the treatment of drug addiction. it is believed that opioids can cause erectile dysfunction (ed) by inhibiting gonadotropin and testosterone release. this study is aimed at defining the possible effects of conservative treatment with methadone on erectile dysfunction in the addicts. methods: a total of 382 ...

objective: successful bonding of a dental implant to bone, which was referred to as osseointegration by branemark has been well documented. however, long-term prognosis of an implant depends on adequate maintenance and long-term care. an effective maintenance program is required to preserve the health of peri-implant tissues. several techniques have been suggested for this purpose but it is not...

a retrospective study was done on 130 aml patients treated in shariati and imam hospitals in tehran from 1991 to 1997 to investigate the value of three post-remission methods of treatment. all patients who were in complete remission (cr) (group i) had been treated with ara-c (300 mg/m2/day continuous infusion for 5 days) and daunorubicine (45 mg/m2/day for 3 days) as induction and early consoli...

background the increase in high-risk injections and unsafe sexual behaviors has led to increased hiv infection prevalence among intravenous drug users (idus). the high costs of hiv/aids care and low financial resources necessitate an economic evaluation to make the best decision for the control of hiv/aids. objectives this study was conducted to determine the cost-effectiveness of methadone mai...

the management of machine replacement (specifically tractors) is one of the most critical factors for performing field operations on time. therefore, tractor repair and maintenance costs must be accurately predicted. this research was carried out to evaluate the use of the regression technique in predicting tractor repair and maintenance costs. the study was conducted using empirical data on 60...

in order to perform preventive maintenance (pm), two approaches have evolved in the literature. the traditional approach is based on the use of statistical and reliability analysis of equipment failure. under statistical-reliability (s-r)-based pm, the objective of achieving the minimum total cost is pursued by establishing fixed pm intervals, which are statistically optimal, at which to replac...