in this study, the performance of an irreversible regenerative brayton cycle is sought through power maximizations using finite-time thermodynamic concept in finite-size components. optimizations are performed using a genetic algorithm. in order to take into account the finite-time and finite-size concepts in the current problem, a dimensionless mass-flow rate parameter is used to deploy time v...

Introduction: Stereotactic body radiotherapy delivers hypofractionated irradiation with high dose per fraction through complex treatment techniques. The increased complexity leads to longer dose delivery times for each fraction. The purpose of this study is to investigate the impact of prolonged fraction delivery time with high-dose hypofractionation on the killing of cultured ACHN cells.Method...

the supercapacitive behavior of polyaniline/mno2-carbon black (pani/mno2-cb), mno2-cb nanocompositesand cb was studied. mno2-cb made by the in situ direct coating method to deposit mno2 onto cb; then pani coating was coated on it. morphology of the nanocomposite was studied by x-ray diffraction (xrd), fourier transform infrared (ft-ir) spectroscopy and scanning electron microscopy (sem). the el...

plants are naturally exposed to frequent changes in environmental conditions such as salt stress affecting their growth and development, and consequently a considerable reduction in total productivity. monodehydroascorbate reductase (mdhar), a key enzyme in ascorbate-glutathione cycle, serves as an important antioxidative enzyme in scavenging of reactive oxygen spices (ros). in this study, mdha...

when the degree of saturation at intersection approaches one, webster’s optimum cycle length equation becomes inapplicable, because the cycle length will becomes very big when the degree of saturation approaches one and will be fully unrealistic when the degree of saturation becomes greater than one. this is not a problem for hcm2000 method. but optimum cycle length calculation in this method h...

Recently, environmental concern and demand for a catalyst’s high performance have increased and many research activities focused on the operation of a three-way catalyst (TWC) at the end of its lifetime. Catalyst aging is the loss of catalytic activity over time that has crucial importance in emission of three-way catalyst.  The aim of this paper is, investigating experimentally the performanc...

In this paper we consider an imperfect production system which produces good and defective items and assume that defective items can be reworked. Due to the nature of rework process we do not restrict the rework rate to be equal to normal production rate or constant and assume that it is a random variable with an arbitrary distribution function. We also assume as it is true in most real world s...

this article proposes an optimization model for preventing the waste of time in the educational and research activities' cycle of an organization such as a university. for this purpose and in order to increase efficiency and prevent the waste of time; the graph theory models have been used. the educational and research activities diagrams of a supposed university is drawn by the use of graphs t...

The theoretical treatment of cycle-effects on total pi-electron energy, mainly elaborated by Nenad Trinajstic and his research group, is re-stated in a general and more formal manner. It enables to envisage several other possible ways of measuring the cycle-effects and points at further directions of research.