Adaptive Rat Swarm Optimization for Optimum Tuning of SVC and PSS in a Power System

This paper presents a new approach for the coordinated design of a power system stabilizer- (PSS-) and static VAR compensator- (SVC-) based stabilizer. For this purpose, the design problem is considered as an optimization problem, while the decision variables are the controllers' parameters. This paper proposes an effective optimization algorithm based on a rat swarm optimizer, namely, adaptive rat swarm optimization (ARSO), for solving complex optimization problems as well as coordinated design of controllers. In the proposed ARSO, instead of a random initial population, the algorithm starts the search process with fitter solutions using the concept of the opposite number. In addition, in each iteration of the optimization, the new algorithm replaces the worst solution with its opposite or a random part of the best solution to avoid getting trapped in local optima and increase the global search ability of the algorithm. The performance of the new ARSO is investigated using a set of benchmark test functions, and the results are compared with those of the standard RSO and some other methods from the literature. In addition, a case study from the literature is considered to evaluate the efficiency of the proposed ARSO for coordinated design of controllers in a power system. PSSs and additional SVC controllers are being considered to demonstrate the feasibility of the new technique. The numerical investigations show that the new approach may provide better optimal damping and outperform previous methods

Ileal intussusception secondary to both lipoma and angiolipoma: a case report

Lipoma and angiolipoma are common benign neoplasms that occur in the subcutaneous tissue and rarely in the gastrointestinal tract. These tumors are usually asymptomatic but may present with abdominal pain, bleeding and obstruction. We present a 53-years-old woman with abdominal discomfort for several weeks accompanied with bloody diarrhea and recurrent vomiting. Ileo-ileal invagination was diagnosed by computed tomography scan. Laparotomy revealed five intraluminal masses that caused intussusception. Histopathological study showed that one was angiolipoma and other lesions were lipoma. We have described some aspects of diagnosis and treatment of this rare cause of intestinal intussusception

Light Intensity and Ultraviolet Radiation in the Libraries and Computer Sites of Ilam Universities

Background: Light is an important and adjustable physical factor in the job environment.This study aimed to determine the intensity of natural and mixed light and also the level of ultraviolet radiation in libraries and computer sites of Ilam universities in spring 2011. Methods: In this cross-sectional study, 10 libraries, 16 study saloons, and 7 computer sites were selected. Luminosity assessing form was used to collect related data about selected places. Light intensity measuring device (Hanger-EC1) and ultraviolet radiation­ intensity measuring device (Hanger- EC1) were used to measure these two variables. Measurement was performed according to the suggested method by IESNA and data analysis was done by SPSS17 software. Results: Mean general light intensity of libraries in mixed and natural conditions, were respectively 235.2±140.2 lux and 198.2±154.6 lux. Maximum mean of Ultraviolet Radiation in mixed and natural conditions were 0.012±0.0131 and 0.008±0.007 w/m2 respectively. These show that light intensity and ultraviolet radiation in the majority of studied units were significantly higher in mixed conditions (natural and artificial light) than in the natural conditions. Conclusion: Improper design and light source selection, oldness of the constructions, and altering the applications of the constructions from administrative places into libraries, studying saloons, and computer sites have caused light intensity lower than the standard levels in these places. Therefore, redesigning the light systems is necessary. Keywords: Light intensity, Ultraviolet radiation, Library, Ila

The Efficiency of Modified Wheat Brad in Reactive Black 5 Dye Removal from Aqueous Solutions

Background: Surface absorption using low cost materials has been an appropriate method to treat lots of industrial wastewater. The aim of this study was application of wheat brad as a low cost adsorbent for reactive black 5 removal from textile wastewater. Methods: In this study, modified wheat brad was used for dye removal from textile wastewater at laboratory scale. Cetylpyridinium chloride monohydrate (CPC) at 2.5 mmol/L was applied for modification of wheat brad. The experiments were conducted at batch system and the effects of parameters such as pH, adsorbent dose, initial dye concentration and contact time on RB5 adsorption by modified wheat brad were studied. Results: According to the results of this study, the minimum and maximum dye removal efficiency were obtained at pH solution 1 and 7 that were 61.54% and 83.15%, respectively. With increasing contact time and adsorbent dose, dye removal efficiency increased. Furthermore, by increasing the dye initial concentration in solution, dye removal rate increased and dye removal efficiency decreased. Based on the results, the Langmuir isotherm and second order kinetics are the best modules for explanation of RB5 adsorption onto modified wheat brad. Conclusion: Considering the high cost of other methods in dye removal, modified wheat brad could be used as a relatively efficient and low cost adsorbent in dye removal from textile wastewater. Keywords: Adsorption, Reactive black 5, Aqueous solutions, Wheat bra

Health impacts quantification attributed to ambient particulate matter in the nearest Iranian city to the main dust source

Urban air contamination is one of the ten most dangerous parameters for human health, which causes cardiovascular disease, respiratory, metabolic diseases, and decreased lung function. Air Q is a reliable software for studying the impacts of atmospheric contaminants on human health, and today, it is widely used in the environment. The purpose of this research was to quantify the mortality and morbidity rates that corresponded to ambient particulate matter (PM) in Rigan City. To perform this, the Air Q software was used. The findings reflected that the yearly mean values of PM10 and PM2.5 are 264.83 and 50.45 μg/m3. The findings indicated that the PM10 and PM2.5 content in Rigan was above standard levels described by WHO. The total number of deaths, cardiovascular deaths, and respiratory deaths due to PM in Rigan were estimated as 70.3, 45.8, and 10.7 persons, respectively. Hospital admissions for cardiovascular and respiratory diseases correlated to PM10 were estimated at 154.2 and 59 persons, respectively. Acute myocardial infarction associated with PM2.5 was 2.7 persons. Overall, the data in this study may be helpful to national and regional policymakers who are responsible for managing and preventing atmospheric contamination and assessing the costs of health risks

Groundwater Quality Assessment Based on Geographical Information System and Groundwater Quality Index

Iran is located in an arid and semi-arid part of the world. Accordingly, the management of the water resources in the country is a priority. In this regard, determining the quality and pollution of surface water and groundwater is very important, especially in areas where groundwater resources are used for drinking. Groundwater quality index (GQI) checks the components of the available water with various quality levels. To assess the quality of drinking groundwater of Yazd-Ardakan plain according to GQI in geographical information system (GIS) environment, the electrical conductivity, sodium, calcium, magnesium, chlorine, pH, sodium adsorption ratio, bicarbonate, sulfate, potassium, water hardness, and all substances dissolved in the waters of 80 wells were determined. The samples were obtained from Yazd Regional Water Organization from 2005 to 2014. Using this data, the map components were plotted by Kriging geostatistical method. Then, the map of GQI was prepared after normalizing each map component, switching to a rating map, and extracting the weight of each component from the rating map. Based on the GQI index map, the index point which was 87 in 2005 has increased to 81 in 2014. These maps show a decline in groundwater quality from west to the east region. This decline in groundwater quality is due to the existence of Neogene Organizations in the east and geomorphologic unit of the bare epandage pediment in the west. The map removal and single-parameter sensitivity analysis showed that GQI index in Yazd-Ardakan plain is more sensitive to the components of electrical conductivity (EC), total dissolved solids (TDS), and total hardness (TH). Therefore, these components should be monitored more carefully and repeatedly

Prevalence of musculoskeletal disorders in Aleshtar city bank staff and its associated factors

Background: Nowadays musculoskeletal disorders are considered as one of the major problems of the workplace and bank staff have been identified as a susceptible group to this disorder. This study aimed to determine the prevalence of bank staffs' musculoskeletal disorders in one of the south western cities of Iran and evaluate their workstations characteristics. Methods: This cross - sectional study was conducted on all bank staffs of one of Lorestan Province's cities in 2012. In order to determine the frequency of musculoskeletal disorders, the standard Nordic questionnaire was used. Workstations were evaluated according to check list. Data analysis was performed by using SPSS16. Results: More than 36 percent of employees had musculoskeletal disorder in one of the nine body zones. Statistically significant associations were found between work experience and musculoskeletal disorders in the neck and lower back; between duration of daily work and disorders of the shoulder; between working extra hours during the week with neck disorders; between marital status and lumbar disorders and between duration of exercise per week and knee disorders. Conclusion: The prevalence of musculoskeletal disorders is high among bank employees and risk factors such as working in sitting position for long hours, working too much with the computer, unadjustable chairs and inappropriate work station design have a significant role in musculoskeletal disorders. These disorders have to be reduced by proper ergonomic arrangement. Keywords: Ergonomic, Musculoskeletal disorders, Bank employee

Stochastic Flexible Power System Expansion Planning, Based on the Demand Response Considering Consumption and Generation Uncertainties

This paper presents the generation and transmission expansion planning (GTEP) considering the switched capacitive banks (SCBs) allocation in the power system, including the demand response program (DRP). This scheme is based on the system flexibility. The objective function of the scheme minimizes the expected planning cost that is equaled to the summation of the total construction costs of the SCBs, the generation units (GUs) and the transmission lines (TLs), and the operating cost of the GUs. It is concerned with the AC power flow constraints, the planning-operation model of the mentioned elements, the DRP operation formulation, and the operating and flexibility limits of the network. In the following, the scenario-based stochastic programming is used to model the uncertainty parameters, such as the load and renewable power of wind farms. Then, the hybrid evolutionary algorithm, based on the combination of the crow search algorithm and the grey wolf optimizer, is used to determine the optimal point with the approximate unique solution. Finally, the scheme is applied on the transmission networks, the numerical results confirm the capabilities of the proposed scheme in simultaneously improving the flexibility, operation, and economic situation of the transmission network, so that the hybrid algorithm achieves the optimal solution in a shorter computation time, compared with the non-hybrid algorithms. This algorithm has a low standard deviation of about 92% in the final response. The proposed scheme with the optimal planning of the lines, sources, and capacitor banks, together with the optimal operation of the DRP succeeded in improving the energy loss and the voltage deviation by about 30–36% and 25–30%, compared with those of the power flow studies

Biodegradation of crystal violet dye by Saccharomyces cerevisiae in aqueous medium

Crystal violet (CV) is an azo dye with cationic nature, belonging to the triphenylmethane group. This study was designed to optimize CV removal by S. cerevisiae from aqueous solutions using BBD model. Harvested cells of S. cerevisiae were locally obtained from Iran Science and Technology Research Organization (ISTRO). The decolorization tests were performed in a laboratory container containing a 100 cc of reaction solution under different variables, including yeast dose (0.5–1.5 g/L), pH (4–10), dye concentration (10–100 mg/L), and the reaction time of 24 h. After stirring with a magnetic shaker at a speed of 400 rpm, 10 cc of each sample was taken and centrifuged at 4000 rpm for 10 min to separate the biomass from dye solution. Then, the supernatant was filtered and finally the remaining CV was measured by a spectrophotometer at λmax 590 nm. After the optimization of the factors mentioned above, the removal efficiency of this dye was investigated at the reaction times of 0.5–72 h. The findings indicated that CV removal ranged from 53.92 to 84.99%. The maximum CV removal was obtained at the CV concentration of 100 mg/L, the pH of 7, and the S. cerevisiae dose of 1.5 g/L. The findings showed that the elimination efficiency is directly related to the initial CV concentration, pH, and S. cerevisiae dose. However, during the reaction time, the elimination efficiency decreased slightly. The findings of this study proved that CV can be removed from aqueous solutions with an easy and low-cost method based on the use of indigenous microorganisms

Effect of Low-Dose Naloxone on Pain Severity and Side Effects of Opioids on Patients Undergoing Laparoscopic Cholecystectomy

Background: Previous studies have assessed effect of naloxone on pain severity and side effects of opioids however, their results are inconsistent. Our study was design to determine effect of low-dose naloxone on pain, nausea, vomiting, pruritus and urine retention on patients undergoing laparoscopic cholecystectomy. Materials & Methods: In this study 60 patients who need laparoscopic cholecystectomy participated and divided into two groups: naloxone (0.25 mg/kg/h naloxone plus 20 mg/kg/h morphine) and placebo (20 mg/kg/h morphine). Patients were evaluated 2, 4, 8 and 16 h after surgery and severity of pain and side effects including nausea, vomiting, pruritus and urine retention were recorded by a nurse. Results: Prevalence of nausea, vomiting, pruritus and urine retention in naloxone group was significantly lower than placebo 2, 4, 8 and 16 h after surgery. There was no significant difference on pain severity between two groups. Conclusion: Our results indicated that naloxone administration significantly decreased side effects of opioid including nausea, vomiting, pruritus and urine retention with no effect on pain severity