812 research outputs found

    Modeling of Power Losses Caused by Hidden Tree-Related High Impedance Faults

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    The great majority of overhead distribution systems in urban and rural areas of countries such as Australia, Iran and etc., are in interfering with vegetation. This phenomena leads to high impedance faults (HIFs) which not produce enough fault current to be detectable and consequently causes electrical energy losses. In this paper, according to experimental data obtained from measurements, the effective factors in power losses caused by trees are studied and a new numerical model of power loss is presented so as to reflect the effects of environmental conditions and biological classification. The base of this method is according to Samuelson theory. In proposed algorithm, the impacts of species, short-term environmental conditions (temperature and humidity) and long-term environmental conditions (Seasonal variations in physiology) on the power loss estimation are fully considered. Experimental investigations on a real low voltage (380 V) and medium voltage (20 kV) distribution network verify the algorithm\u27s operation

    Effect of ghrelin peripheral administration on growth performance, carcass quality, and selected serum parameters in broiler chickens

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    ΔΕΝ ΔΙΑΤΙΘΕΤΑΙ ΠΕΡΙΛΗΨΗThe aim of present study was to investigate the short-term and long-term effect of the peripheral administration of ghrelin on the growth performance (feed intake, weight gain, and feed conversion ratio), carcass quality, and selected serum biochemical (glucose, total cholesterol, triglyceride, and total protein) and hormonal (T3, T4, and corticostrone) indices in broiler chickens. 240 one-day-old broiler chickens were selected, and allocated into three treatment groups (control and two experimental groups). On day-21 of the rearing period, ghrelin was peripherally administrated to three experimental groups. The control group contained birds without any administration of peptide or solution, groups G50 and G100; included birds with Ip-injection of 50 and 100 (ng/100g BW) ghrelin peptide, respectively. The peripheral administration of exogenous ghrelin did not affect feed intake, body weight gain (BWG), feed conversion ratio (FCR) and carcass characteristics in broiler chickens. In short-term samples taken 12h after ghrelin infusion, the glucose level was increased in ghrelin-treated groups (162 and 151 mg/dl in G50 and G100 compared with 117 mg/dl in control; P< 0.01) and there were significant declines for TC, triglyceride, and TP in the ghrelin-treated groups (G50 and G100) compared with the control. In addition, long-term glucose level has a greater value in G50 and G100 (182 and 200.66 mg/dl) compared with control (133.60 mg/dl) group (P< 0.01). A significant decline was also observed for TC and triglyceride content in the ghrelin-treated groups (P<0.05). There was no significant difference among groups for TP in short-term and long-term samples. There was a significant increase for T4 in ghrelin-treated groups (G50 and G100) compared with the control (4.55 and 4.57 ng/ml vs 4.20 ng/ml respectively; P< 0.05) in long-term samples. In conclusion, the peripheral administration of ghrelin in broiler chickens, during the commercial rearing period did not affect the overall growth performance, carcass quality and feed conversion ratio. The infusion of exogenous ghrelin may increase the levels of serum glucose, decrease total cholesterol and triglyceride, and T4 levels are increased in the long-term (and not in the short-term or 12h after administration)

    THE PREVALENCE OF CUTANEOUS LEISHMANIASIS IN EAST OF AHVAZ COUNTY, SOUTH-WESTERN IRAN

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    Objectives: Cutaneous Leishmaniasis (CL) is a zoonotic parasitological disease. This disease cause always important health challenges for the human communities. It is common in many parts of the globe. This research was designed to determine the epidemiology of CL in East of Ahvaz County during 2003- 2013. Methods: This was a descriptive cross-sectional study. The disease was diagnosed based on clinical examination and microscopic observation of the parasite in the ulcer site. The patient's Information such as age, gender, number and sites of ulcer (s) on the body, month and residence area were recorded. Data analysis was performed using SPSS software. Results: Totally, 2287 cases were detected during 2003 2013. About 53.4 patients were male and 46.4 female. The highest frequency infected age groups were observed in 10-19 years old (n=550 ,24). Nearly 37 of the patients had one and 38.1 had three ulcers. The most common location of ulcers were on hands (n=1022, 44.7) and then on feet (n=501, 21.9). Totally 1877 of the patients were infected in rural areas. Based on the appearance of the lesion it was found that 410 cases (17.9) were of the dry type and 1877 cases (82.1) were wet type. Concluaions: Such high prevalence and incidence rates are alarming and require control and prevention measures. Further epidemiological studies of CL are suggested

    Analysis and Control of mortar Quality with ultrasonic wave attenuation

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    Wave propagation and attenuation on mortar material are discussed in this paper with a Non Destructive Testing (NDT) which can be used to characterize samples of mortars and effect of microstructure of sand in their hardening. Samples were manufactured using same water/cement ration (w/c) 0.65, and cement/sand ration (c/s) 0.5 in order to simulate the attenuation. The characterization of attenuation in mortar material has been performed by ultrasonic reflection technique using a transducer with central frequency 0.5MHz. It is shown that sand particle size exercises significant influence on the evolution of attenuation, the attenuation parameters give information about average state of the hardening of the mortar itself

    A Ranking Method Based on Common Weights and Benchmark Point

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    The highest efficiency score 1 (100% efficiency) is regarded as a common benchmark for Decision Making Units (DMUs). This brings about the existence of more than one DMU with the highest score. Such a case normally occurs in all Data Envelopment Analysis (DEA) models and also in all the Common Set of Weights (CSWs) methods and it may lead to the lack of thorough ranking of DMUs. And ideal DMU based on its specific structure is a unit that no unit would do better than. Therefore, it can be utilized as a benchmark for other units. We are going to take advantage of this feature to introduce a linear programming problem that will produce CSWs. The proposed method assures that the efficiency of all the units is less than that of the benchmark unit. As a result, it provides a comprehensive ranking of DMUs. Moreover, the proposed method is also noteworthy regarding computation. A numerical example is suggested to clarify and explain the proposed method and compare it to two other CSWs methods. Finally, 33 universities in Iran were ranked and compared using the proposed method

    Application of novel Modified Biological Aerated Filter (MBAF) as a promising post-treatment for water reuse: Modification in configuration and backwashing process

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    Biological Aerated Filter (BAF) reactors due to their plentiful biomass, high shockability, high efficiency, good filtration, availability and lack of need for large land areas, are enjoying from great importance in advanced wastewater treatment. Therefore, in this study, Polystyrene Coated by Sand (PCS) was produced as a novel media and its application in a modified down-flow BAF structure for advanced wastewater treatment was assessed in two steps. In step one, the backwash effluent did not return to the system, while in step two backwash effluent returned to increase the water reuse efficiency. The backwash process was also studied through three methods of Top Backwashing (TB), Bottom Backwashing (BB), as well as Top and Bottom Backwashing Simultaneously (TBBS). The results showed that return of backwash effluent had no significant effect on the BAF effluent quality. In the second step similar to the first one with slight differences, the residual average concentrations of TSS, BOD5, and COD at the effluent were about 2.5, 8.2, and 25.5 mg/L, respectively. Additionally, in step two, the mean volume of disposal sludge/volume of treated water (v(ds)/v(tw)) decreased a large extent to about 0.088. In other words, the water reuse has increased to more than 99.91. The backwash time in methods of TB and BB were 65 and 35 min, respectively; however, it decreased in TBBS methods to 25 min. The concentrations of most effluent parameters in this system are in concordance with the 2012 EPA Agriculture Standards, even for irrigation of Non-processed agricultural crops and livestock water consumption. (C) 2017 Elsevier Ltd. All rights reserved
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