Oxygen transport across the cathode gas diffusion layer (GDL) in polymer electrolyte membrane (PEM) fuel cells was examined by varying the O2/N2 ratio and by varying the area of the GDL extending laterally from the gas flow channel under the bipolar plate (under the land). As the cathode is depleted of oxygen, the current density becomes limited by oxygen transport across the GDL. Oxygen deplet...

Encoded video streams present numerous problems in bandwidth allocation, multi-plexing and admission control as a result of their Variable Bit Rate(VBR) characteristics. In particular, since video signals show a large range of variability, peak rate allocation results in very low bandwidth utilization. However, other allocation schemes tend to cause cell loss, delay and delay jitter which make ...

In this paper, we analyze the system utilization of a deployed radio communication network operated by a public safety agency. The network consists of a central site and a number of cells, each cell having a different capacity (number of available radio channels). The network is circuitswitched. Hence, the system utilization is a distribution of the number of concurrent calls in each cell vs. t...

This paper describes how to coordinate autonomous mobile multi-agents, whose agents stochastically move over a finite resource consisting of cells in accordance with transition probabilities. We assume there are interactions or coordination among agents such that (1) each agent cannot move to a destination cell occupied by agents more than the agents of a current cell and (2) their agents have ...

This paper is in search of designing the cellular manufacturing systems (CMSs) under dynamic and flexible environment. CM is proper for small-to-medium lot production environment that helps the companies to produce variable kind of productions with at least scraps. The most important benefits of CM are decline in material handling, reduction in work-in-process, reduction in set-up time, increme...

Glycerol is a promising feedstock for microbial cultivation and production of 1,3 propanediol (1,3 PDO). Here we report a newly isolated bacterial strain BA11 from soil, capable of fermenting glycerol to 1,3 PDO, and has been identified to be a strain of Klebsiella pneumoniae. Strain BA11 was fast growing showing peak 1,3 PDO production in 6 h of cultivation with productivity of 1.2 g/...

Titratable systems are common tools in metabolic engineering to tune the levels of enzymes and cellular components as part of pathway optimization. For nonmodel microorganisms with limited genetic tools, inducible sugar utilization pathways offer built-in titratable systems. However, these pathways can exhibit undesirable single-cell behaviors that hamper the uniform and tunable control of gene...

drug utilization evaluation (due) studies are designed to assess drug usage appropriateness. we aim to evaluate the drug utilization of intravenous ciprofloxacin and imipenem, two of the broad spectrum antibiotics that consume a significant proportion of our hospitals’ outlay, in different wards of a teaching hospital in zabol. during a 5 months period (december 2010 to may 2011), 263 patients ...

this study was performed to assess the incidence of medication errors and irrational use of human albumin in two wards of our hospital and also aimed to evaluate the ability of pharmaceutical care center and pharmacists in improving patient care. albumin administration was evaluated for patients who received albumin during the study period, in gastroenterology and general surgery wards. the ind...