Frequency and voltage partitioning in presence of renewable energy resources for power system (example: North Chile power network)

This paper investigates techniques for frequency and voltage partitioning of power network based on the graph-theory. These methods divide the power system into distinguished regions to avoid the spread of disturbances and to minimize the interaction between these regions for frequency and voltage control of power system. In case of required active and reactive power for improving the performance of the power system, control can be performed regionally instead of a centralized controller. In this paper, renewable energy sources are connected to the power network to verify the effect of these sources on the power systems partitioning and performance. The number of regions is found based on the frequency sensitivity for frequency partitioning and bus voltage for voltage partitioning to disturbances being applied to loads in each region. The methodology is applied to the north part of Chile power network. The results show the performance and ability of graph frequency and voltage partitioning algorithm to divide large scale power systems to smaller regions for applying decentralized controllers.Peer ReviewedPostprint (published version

Estimation of growth parameters and mortality rates of kingfish (Scomberomorus commerson) in the north of Persian Gulf (Khuzestan Province)

Length composition data from monthly catches of Scomberomorus commerson landed in Choebdeh and Hendijan fish landing places in Khuzestan Province, north Persian Gulf, were collected from 2004 to 2005. We used the data to estimate growth parameters and mortality coefficients of the fish. Response surface analysis produced by the ELEFAN program provided a complete set of Von Bertalanffy growth parameters estimation. We found L infinity =120cm (fork length), K=0.49per year and t_0=-0.11 year for the fish. The length-weight relationship was estimated as W=0.022tL ^2.7575 with r^2=0.978S. Based on the calculated b, we conclude that the fish has an isometric growth pattern. The total, natural and fishing mortality coefficients were estimated as, Z=1.58, M=0.58 and F=1.0, respectively. Exploitation ratio (E) for this species was estimated as 0.63 per year. The E-value indicates that the kingfish in this part of the Persian Gulf has been overexploited. Current fishing pattern in the Khuzestan province shows that 97.07% of the cumulative length frequency and 78.18% of the cumulative weight frequency of the landed fish are under standard size. Results of this study indicate that exploitation of kingfish does not follow an optimum trend and if this trend continues, the stock of Scomberomorus commerson in this area will be threatened

Evaluating the effect of foeniculum vulgar on scopolamin-induced memory impairment in Male Mice

Background: Estrogen is a steroid that regardless of its obvious effects on females’ reproductive functions shows beneficial effects on cognition. Foeniculum vulgar (fennel) has phytoestrogen compounds that might be beneficial in memory performance. This research was performed to understand if this plant can improve memory. Methods: To evaluate memory, novel object recognition task was used in male Balb-c mice, which comprised of three sections: habituation, learning trial (T1) and the test trial (T2). In this method, the difference in the exploration time between a familial (F) and a novel (N) object is taken as an index of memory performance [recognition index (RI) = (N – F)/(N + F) × 100]. Findings: Memory was harmed using 0.5 mg/kg subcutaneous scopolamine [RI (%) = -16.0 ± 3.0]. 50 mg/kg intraperitoneal fennel considerably prevented memory impairment of scopolamine [RI (%) = 35.0 ± 7.1] and this was parallel with the memory index in normal animals [RI (%) = 50.0 ± 5.8]. In addition, 0.2 mg/kg intraperitoneal 17-β estradiol showed similar results as fennel on memory protection [RI (%) = 36.0 ± 6.6]. However, the beneficial effects of fennel were impaired by prior intraperitoneal injection of 1 mg/kg tamoxifen [RI (%) = -29.0 ± 7.1]. Conclusion: The beneficial effect of fennel on memory is achieved by estrogenic receptors present in the brain; by stimulating these receptors, they could cause an increase in acetylcholine release. Therefore, it can competitively prevent the antagonizing effect of scopolamine on cholinergic receptors. © 2015, Isfahan University of Medical Sciences(IUMS). All rights reserved. Evaluating the effect of foeniculum vulgar on scopolamin-induced memory impairment in Male Mice. Available from: https://www.researchgate.net/publication/282273930_Evaluating_the_effect_of_foeniculum_vulgar_on_scopolamin-induced_memory_impairment_in_Male_Mice [accessed Jul 29, 2017]

A Comparative Study on Critical Thinking Skills of Bachelor and Master's Degree Students in Critical Care Nursing

Background: Promoting critical thinking skills is an essential outcome of undergraduate and postgraduate nursing education. Objectives: The current study aims at comparing critical thinking skills of bachelor students of nursing (BSc) and master’s students of critical care nursing (MSc) in the academic year 2014 - 2015. Methods: The current cross-sectional study was conducted on 79 BSc students of nursing and 44 MSc students of critical care nursing in 3 universities of medical sciences including Semnan, Tehran, and Kashan. The California critical thinking test, form B, was used for data collection. Analysis of variance Mann-Whitney, and Kruskal-Wallis tests were used for statistical analyses. Results: Themeanscores of BS and MSc nursing students were 11.14�3.01 and 10.05�3.33, respectively, which were not significantly different. The mean scores of students in Semnan, Tehran, and Kashan universities of medical sciences were 9.84 � 3.13, 9.66 � 3.32, and 11.79 � 2.92, respectively, and the total mean score was 10.46 � 3.24. The scores of critical thinking domains showed that students in Kashan University gained higher scores in interference, and deductive and inductive reasoning domains compared with the students in other universities. Conclusions: The level of critical thinking in BSc students was higher. The overall level of critical thinking skills was low in nursing students. It is suggested that appropriate and effective methods should be employed to create and improve critical thinking in nursing education

Sex ratio and length determination at the onset of maturity of rock oyster Saccostrea cucullata in the Oman Sea

Sex ratio and length at maturity in the rock oyster, Saccostrea cucullata was studied in the Iranian shores of Oman Sea. Monthly sampling was conducted 10 stations within one year period (March 1996 to February 1997). Results indicated that sex ratio is 1:1. Among the first matured age groups, nearly 67 percent of the samples were male and 33 percent were female. With increasing size, the percentage of females were increased, indicating a protandric nature. More than 50 percent of the samples were matured when their length exceeded 36 mm. Smallest matured specimen had a length of 22 mm

A Comparative Study on Critical Thinking Skills of Bachelor and Master�s Degree Students in Critical Care Nursing

Background: Promoting critical thinking skills is an essential outcome of undergraduate and postgraduate nursing education. Objectives: The current study aims at comparing critical thinking skills of bachelor students of nursing (BSc) and master’s students of critical care nursing (MSc) in the academic year 2014 - 2015. Methods: The current cross-sectional study was conducted on 79 BSc students of nursing and 44 MSc students of critical care nursing in 3 universities of medical sciences including Semnan, Tehran, and Kashan. The California critical thinking test, form B, was used for data collection. Analysis of variance Mann-Whitney, and Kruskal-Wallis tests were used for statistical analyses. Results: Themeanscores of BS and MSc nursing students were 11.14�3.01 and 10.05�3.33, respectively, which were not significantly different. The mean scores of students in Semnan, Tehran, and Kashan universities of medical sciences were 9.84 � 3.13, 9.66 � 3.32, and 11.79 � 2.92, respectively, and the total mean score was 10.46 � 3.24. The scores of critical thinking domains showed that students in Kashan University gained higher scores in interference, and deductive and inductive reasoning domains compared with the students in other universities. Conclusions: The level of critical thinking in BSc students was higher. The overall level of critical thinking skills was low in nursing students. It is suggested that appropriate and effective methods should be employed to create and improve critical thinking in nursing education

Morphometric study on Sepia pharaonis in the Persian Gulf and Oman Sea

The pharaoh cuttlefish (Sepia pharaonis) is the most aboundant species in the Persian Gulf and Oman Sea. The stock patterns of this species were studied concerning biological and morphological aspects. In addition to measuring the biological patterns, 20 quantitative factors were measured. The results of LSD test showed that tentacle organ is indicative factor which shows significant difference between male and female specimen of Bushehr and Balouchestan regions. Regarding to length and weight frequencies data the results indicated that males are always bigger than females and also, the cuttlefishes of the Gulf of Oman are bigger than Persian Gulf samples. The results of cluster analysis for both sexes showed that the cuttlefishes of both studied region belong to separate stocks. Taking into consideration the findings of present study including: (1) difference in spawning season, (2) results of dendrograms, (3) observed significant differences in one-way analysis of variance (ANOVA) for morphometric measurements, (4) differences in body length and weight, (5) as well as ecological variations of the Persian Gulf and "the pharaoh cuttlefishes of Bushehr and Oman Sea, have indicated that Balouchestan belong to two separate stocks

Growth comparison between post-larvae from cultured and wild spawners of Indian white shrimp, Penaeus indicus, in commercial farms in north Persian Gulf, Bushehr, Iran

Post larvae of wild and cultured spawners of the Indian white shrimp (Penaeus indicus, Milne Edwards, 1837) were reared to market size, in commercial ponds of shrimp farming site of Helleh, in Bushehr Province, during a six months period. Environmental factors, management process and the diet used to feed shrimps were almost similar for both treatments. Averages of the weight, length, specific growth rate, food conversion ratio and survival rate were measured and compared between the two treatments at harvesting time. Results indicated that, the post larvae of wild spawners had better growth, higher survival rate, and lower food conversion ratio. Weight gain of abdominal portion of the body, was higher in wild post larvae (P<0.01), which was in contrast to cephalothorax weight (P<0.01). Length-weight relationship measurements illustrated that, cultured post larvae obtained from wild spawners had similar size and were more acceptable for the market. Broodstock background could be the main reason for given differences, in which, those captured from the sea, had better condition due to receiving appropriate food with higher genetic diversity. To produce high quality post larvae for the expanding shrimp farming industry as an economic activity in the country, it is suggested that broodstocks to be obtained either from the sea as sub-adults or matured spawners, or to be provide from culturing shrimps, raised in conditions closest to the nature (i.e., ambient factors, prepared diets) and also with appropriate genetic diversity

Rapid assessment of the fuel economy capability of parallel and series-parallel hybrid electric vehicles

Efficiently solving the off-line control problem represents a crucial step to predict the fuel economy capability of hybrid electric vehicles (HEVs). Optimal HEV control approaches implemented in literature usually prove to be either computationally inefficient or sub-optimal. Moreover, they often neglect drivability and comfort associated to the generated control actions over time. This paper therefore aims at introducing a rapid near-optimal approach to solve the off-line control problem for parallel and series-parallel HEV powertrains while accounting for drivability criteria such as the frequency of gear shifts and the number of activations of the thermal engine. The performance of the introduced slope-weighted energy-based rapid control analysis (SERCA) algorithm is compared with the global optimal benchmark provided by dynamic programming (DP) for both the parallel and the series-parallel HEV layouts over different driving missions. Results demonstrate how the SERCA algorithm can produce comparable control results with respect to DP by limiting the increase in the estimated fuel consumption within 2.2%. The corresponding computational time can be simultaneously reduced by around 99.5% while ensuring a limited number of gear shifts and engine activations over time. Engineers could therefore potentially implement the proposed SERCA algorithm in design and calibration procedures of parallel and series-parallel HEVs to accelerate the overall vehicle development process

Evaluation of expression ratio of HOXB13:IL17BR in patients with breast cancer by qRT-PCR method using SYBR Green dye

Background and aims: Studies have shown that a HOXB13:IL17BR expression ratio index predicts clinical outcome in ER-positive, lymph node-negative breast cancer patients that treated with adjuvant tamoxifen. All of these experiments were conducted with qReal Time RT-PCR using TaqMan probes. The aim of this study was to determine the ratio using SYBR Green I qReal Time RT-PCR. Methods: In this case- control study, expression levels of HOXB13:IL17BR was measured in 40 paired formalin-fixed, paraffin-embedded primary breast tumor specimens. After extracting RNA from the tissues, cDNA synthesis and amplification with the polymerase chain reaction to obtain the optimum annealing temperature, the expression levels was measured by SYBR Green I qReal Time RT-PCR. To determine and normalize the expression levels, BestKeeper software was used to obtain the BestKeeper Index using the geometric mean of expression levels of housekeeping genes. Comparison of mean expression of genes between tumoral and non-tumoral tissues was performed by t-test and association between patient grouping (high/low risk) and time for disease free survival was assessed by Fisher`s Exact test. Results: HOXB13:IL17BR expression value did not show significant difference between tumoral and non-tumoral tissues. The results showed that there was a direct and significant association between patient grouping (based on HOXB13:IL17BR ratio) and disease free survival status. Conclusion: Results in the current study showed that in spite of using SYBR Green dye (instead of TaqMan probes), there is still a significant correlation between HOXB13:IL17BR ratio and disease free survival status