the present paper deals with development of a simulation model for the performance evaluation of feed water system of a thermal power plant using markov birth-death process and probabilistic approach. in present paper, the feed water system consists of four subsystems. after drawing transition diagram for feed water system, differential equations are developed and then solved recursively using ...

this study examined the effect of urbanization on agricultural production in abia state. specifically, it categorized the land tenancy status of the farmers, analyzed the effect of urbanization on agricultural productivity and identified the constraints to agricultural productivity. multistage random sampling technique was used to select the respondents. primary data collected using structured ...

background: in the recent years nanostructured materials have been the focus of researches due to their wide-spread possibilities to provide new shapes and structures for some materials. microemulsions can provide uniform nano-sized droplets for templating. microemulsions are isotropic, thermodynamically-stable systems of oil, water and surfactant with a 20-200 nm droplet size. they can be prep...

in this paper, we study different methods of solving joint redundancy-availability optimization for series-parallel systems with multi-state components. we analyzed various effective factors on system availability in order to determine the optimum number and version of components in each sub-system and consider the effects of improving failure rates of each component in each sub-system and impr...

background & aim :facilitating people’s access to necessary health services is one of the most important strategies to reach social justice within countries’ health system. therefore in-time access to health cares and ensuring desirable results are essential. this study was conducted to evaluate the perception of martyrs’ parents of accessing the services of health monitoring plan. materials an...

to effectively design daylight in buildings, daylight availability data are necessary. although there is a great potential for daylight energy in iran, its use has been hampered by the absence of measured data. in this paper the illuminance data on the vertical south facing surfaces of tehran were estimated using the iesna model. for this propose an illuminance measuring set was used in order t...

the impact of the international sanctions on the central bank of iran in 2013 and also accessibility of medicines in this country have received a lot of media coverage. in this study we used the data collected from a group of pharmacies all located in tehran to assess the potential effects of the banking sanctions on access to asthma medicines. data were collected from forty community pharmacie...

In this paper, an exact geometric algorithm is presented for solving two-job sequencing and scheduling problems in flexible flow shop and job shop environments while the resources are (un)available in some time periods and processors (un)availability is the same in all work centers. This study seems utterly new and it is applicable to any performance measure based on the completion time. The in...