An Investigation of the Influences of the Voltage Sag on the Doubly Fed Induction Generator using Tuned PI Controllers

The paper presents dynamic and transient behavior of the doubly fed induction generator (DFIG) in the wind farms in the normal and faulted grid respectively. When Voltage sag or any fault occurs in the network, the variables in the Doubly Fed Induction Generators are varying severely. If a voltage sag occurs, active and reactive power generated by the DFIG start to oscillate. The DC-link voltage will be bigger and will have fluctuation, and the rotor current will increase. In this paper, proportional integral (PI) controllers are used to control the DFIG in the wind farms for driving of the electronic devices including Rotor Side Converter (RSC) and Grid Side Converter (GSC) and controlling the active and reactive power of DFIG. PI parameters are tuned by particle swarm optimization algorithm (PSO). Whereas the model of DFIGs and electronic device in the paper are nonlinear so PI controllers cannot protect and control the DFIG as well. Hence, effect of PI parameters is investigated on the DFIG with simulating in MATLAB software. Also, low voltage ride through (LVRT) feature for DFIG is explored in presence of PI controllers. The results of the simulation present DC-link over voltage and rotor and stator over current in the DFIG. In addition, it will explore the effect of proportional integral controllers when three-phase short circuit fault occurs

Comparison of death anxiety, self-concept and attitudes to old age in the elderly living on their own, residing in nursing homes full-time or part-time, or living with extended families in Kermanshah, Iran

Background and Objective: Old age is an important period of life, and paying attention to the issues and needs of this course is a social necessity. Therefore, the present study aimed to compare death anxiety, self-concept and attitudes to old age in the elderly living on their own, residing in nursing homes full-time or part-time, or living with extended families in Kermanshah, Iran. Materials and Methods: In this descriptive and causal-comparative study, the statistical population consisted of the elderly living on their own, residing in nursing homes full-time or part-time, or living with extended families in Kermanshah, Iran over 2016-2017. A total of 304 subjects were selected through random sampling and convenience sampling. As for data collection, three questionnaires were employed:  Templer's Death Anxiety Scale  (1970), Beck’s Self-concept Inventory (1990), and Kogan's Attitudes toward Older People Scale (KAOPS) (1961). Results: The mean scores of just death and general factor of the variable of death anxiety and the mean scores of negative and positive attitudes of the elderly residing in nursing homes full-time were lower than those of other groups. In addition, the mean score of self-concept of the elderly living on their own was higher than those of other groups. Discussion and Conclusion: The levels of death anxiety and attitudes towards old age in the elderly residing in nursing homes were lower than those in other groups. It was also concluded that the level of self-concept of the elderly living on their own was higher than those of other groups

The causes of consent to and refusal of organ donation by relatives of brain dead patients in Chaharmahal and Bakhtiari Province, Iran; A letter to the editor

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Optimization of the production of a self-stable powder from date fruit variety ‘Shahani’

The objective of this study was to prepare a self-stable powder from date paste. The concept of glass transition temperature (Tg) was used to predict the stability of powder at room temperature. The effect of maltodextrin (MD) as a drying additive in the range of 28 - 55%, tricalcium phosphate (TCP) as an anti-caking agent and glycerol monostearate (GMS) as a flowability agent in the range of 0.3 - 3% on some physico-chemical and thermal properties of the date powder was studied, using response surface methodology (RSM). Proposed mathematical models were successfully capable to fit the experimental results for different physico-chemical properties of the powder such as moisture content, bulk density, solubility, Tg, hygroscopicity and color index (L*, a*) with high R2 values (R2 > 0.9). The optimal combination of additives was determined as 35% MD, 3% TCP and 3% GMS with the overall desirability of 82.3%

Survey factors related to consent to organ donation in families of brain death patients in hospitals affiliated with Shahrekord University of Medical Sciences

In the past decades, the need for organ donation has increased while consent rate continues to remain inadequate. One of the most important limiting factors in organ donation is families’ refusal to grant consent, and therefore it is important to determine the circumstances influencing the phenomenon. The aim of this study was to investigate the factors affecting consent to organ donation in families of brain death patients in hospitals affiliated with Shahrekord University of Medical Sciences. For this purpose, a self-made questionnaire was distributed among 54 family members of brain death patients admitted in hospitals affiliated with Shahrekord University of Medical Sciences between 2003 and 2013. The data were reported as mean, frequency and percentage using the SPSS16 software. The average age of the deceased was 31.38 ± 13.72 years, and car accidents were the most frequent cause of brain death (59.3%) in this study. In addition, 72.2% of the deceased were male and 90.7% of them lived in or around the city of Shahrekord. About 37% of the families consented to organ donation. The average age of the family members who participated in the study was 42.15 ± 8.9 years. The most frequent reasons affecting families’ consent to organ donation were religious rewards (100%), confidence in the medical team and staff (100%), and confidence in physician diagnosis (100%).The findings of the study show that religion, faith and family ties affect the willingness for organ donation, and therefore specific attention should be given to these factors in educational programs. In the present study, religious beliefs and confidence in the performance of health care workers were highlighted as the most effective factors in consent to organ donation in brain dead patients' families. Consequently, in order to increase organ donation rate, special attention to these factors and proper planning is necessary

Assessment of Uncivil Behaviors of Teachers and Students in Nursing and Midwifery faculties of Shahrekord

Introduction: The aim of this study was determining the uncivil behaviors of teachers and students, in nursery and midwifery schools of Shahrekord in 2016. Methods: This cross-sectional study used a questionnaire containing questions on uncivil behavior (disruptive and threatening). Participants were 20 teachers and 150 students of Nursing and Midwifery department of Shahrekord university of Medical Sciences from three fields (nursing, operating room and midwifery). The collected data was analyzed in the form of mean, standard deviation, percent and frequency and analytical tests such as Pearson, chi-square and Phi. Results: The average age of the fifty participants from each field of study was 54/4 ± 06/22 years. Of the 20 professors participating in the study, 90% were female and the average age was 38/9 ± 43/43 years. According to the findings, the participants thought the prevalence of uncivil behaviors was moderate. Professors found students more responsible for such behaviors (40% vs. 60%) while students believed both groups of participants were guilty. Conclusion: Although the frequency and severity of uncivil behaviors by students and teachers were not considerable, but due to the negative effects of such behaviors in learning and teaching environments, appropriate strategies to improve learning environments is highly necessary

Evaluating the effect of a herb on the control of blood glucose and insulin-resistance in patients with advanced type 2 diabetes (a double-blind clinical trial)

Background: Different benefits of various herbal medicines in decreasing blood sugar have been reported in different clinical trials so far. Considering the growing tendency toward these combinations and the booming market, inappropriate advice is growing accordingly. Hence, it is necessary to evaluate the effects and possible complications of such combinations on health status and blood glucose control. Methods: Two 38-subject groups were formed and a 12-week treatment program was administered for both groups. The inclusion criteria were failure to control blood glucose with two oral medicines, unwillingness to inject insulin. The medicine was prepared in capsules by Booali Company. Each capsule weighed 750 mg and contained nettle leaf 20 (w/w), berry leaf 10 (w/w), onion and garlic 20 (w/w), fenugreek seed 20 (w/w), walnut leaf 20 (w/w), and cinnamon bark 10 (w/w) all in powder. Results: At the beginning of the study, there was no significant difference between the subjects regarding the evaluated parameters, but after the intervention, the level of glucose was significantly lower in fasting (P=0.0001) and 2-hour postprandial(P=0.002) levels. The level of glycated hemoglobin A1c (HbA1c) (P=0.0001) also decreased from 0.33±9.72 to 0.20±8.39 . Finally, the level of insulin resistance reduced from 1.9±4.1 to 1.4±2.6 (P=0.001) after consuming herbal medicine. Conclusion: According to the results of the current study, the herbal combination was effective in controlling blood sugar, and considering the reduction of HbA1c by 1.31 , it seems that the herbal combination is an effective medicine to treat diabetes. &#160

Clinical, Laboratory, and Obstetrics Features of Novel Coronavirus Disease 2019 (COVID-19) during Pregnancy

Background: The novel coronavirus disease 2019 (COVID-19) remains a new entity; the data on its clinical features, complications, and adverse outcomes during pregnancy are still to be identified and described. Several studies have reported a series of COVID-19 infections in pregnancy, the maternal and the neonatal outcome from different ethnicities and geographical regions. Materials and Methods: This retrospective cross-sectional study was conducted in the obstetrics department of Mahdiyeh Hospital of Tehran, Iran, between February and April 2020. We included a series of 23 singleton pregnancies presenting to our department with fever and dry cough. All patients were tested for COVID-19 infection using nasopharyngeal swabs. Results: We included 23 singleton pregnant patients with a mean age of 28.1 ± 6.16 (ranging from 15 to 39) years and gestational age of 29.96±10.2 [ranging from 7 to 40] weeks. Of these patients, 7 (30.4%) tested positive for the SARS‑CoV‑2. Among the total patient population, 16 (69.5%) had elevated serum levels of C-reactive protein (CRP), 1 [4.3%] had lymphopenia, and 8 (34.7%) had elevated erythrocyte sedimentation rate (ESR). Only 2 (8.7%) patients had positive findings of chest CT-scan. Most newborns had acceptable Apgar and birth weight, and only 4 (17.4%) required NICU admission. Conclusion: The clinical characteristics of the COVID-19 infection in pregnant patients were comparable to those of non-pregnant patients. We did not record a high frequency of lymphopenia and leukopenia, probably due to leukocytosis during pregnancy. CRP was a sensitive marker for COVID-19 pneumonia in pregnant patients

Effect of Combination Therapy of Ceftazidime/Amikacin and Monotherapy with Imipenem on the Treatment of Fever and Neutropenia in Patients with Cancers

AIM: This study aimed to compare the effect of Imipenem monotherapy and combination therapy with Ceftazidime/Amikacin in febrile episodes in neutropenic cancer patients.MATERIALS AND METHODS: In this double-blind randomised trial, 122 adult patients with cancer, neutropenia and fever who were treated by chemotherapy were gathered by simple sampling method and were divided randomly to two equal Imipenem (IP) and Ceftazidime/Amikacin (CA) groups. 500 mg of Imipenem was administered every 6 hours IP group and 2 g of Ceftazidimeplus 15 mg/kg/day in 2 equally divided doses of Amikacin was administered in the CA group. The treatment was continued for 72 hours in both groups. Data were analysed with SPSS19.RESULTS: There was a significant difference between the mean temperatures of three days in each group (P < 0.001). There was no significant difference between the two groups regarding microbial response to antibiotics. There was no significant difference between 19 patients of IP and 13 patients of CA groups regarding bacteriologically documented infection (P = 0.3).CONCLUSION: Unmodified therapy by Imipenem is as effective as combinational therapy by Ceftazidime/Amikacin in clinically and bacteriologically documented infection