Reduced Order Modeling of a Shipboard Power System

Reduced-order average-value models form the basis of a computationally efficient approach for studying shipboard power systems. As a result of neglecting fast states, this approach generally involves solving a set of differential algebraic equations. Although the reduced-order average-value modeling approach has been well studied in the literature, as simulation languages evolve the most programmatic approach to addressing the non-linear algebraic portion of the model changes as well. In this work, a number of approaches for implementing reduced-order average-value models of a small power system are compared.Center for Electromechanic

The Physics of Star Cluster Formation and Evolution

© 2020 Springer-Verlag. The final publication is available at Springer via https://doi.org/10.1007/s11214-020-00689-4.Star clusters form in dense, hierarchically collapsing gas clouds. Bulk kinetic energy is transformed to turbulence with stars forming from cores fed by filaments. In the most compact regions, stellar feedback is least effective in removing the gas and stars may form very efficiently. These are also the regions where, in high-mass clusters, ejecta from some kind of high-mass stars are effectively captured during the formation phase of some of the low mass stars and effectively channeled into the latter to form multiple populations. Star formation epochs in star clusters are generally set by gas flows that determine the abundance of gas in the cluster. We argue that there is likely only one star formation epoch after which clusters remain essentially clear of gas by cluster winds. Collisional dynamics is important in this phase leading to core collapse, expansion and eventual dispersion of every cluster. We review recent developments in the field with a focus on theoretical work.Peer reviewe

Assessment of Bus Drivers’ Exposure to Respirable Particles (PM10) in Sari

AbstractBackground and purpose: High concentrations of respirable particles may cause high incidence of respiratory diseases and mortality in public populations and in particular in public transportation workers. Epidemiological exposure studies showed that respirable particles that emitted from traffic sources have more potential effects on more incidence of hospitalization or mortality caused by cardiovascular diseases. In this study personal exposures of bus drivers to respirable particles (PM10) and factors that caused high personal exposure were studied in Sari city.Materials and Methods: In this study, a calibrated real time monitor (MicroDust Pro) with a personal sampling pump with 2 lit/min flow rate were used to measure Sari’s bus drivers personal exposure to PM10 concentrations on 3 main routs. This study was carried out during a one calendar year and all possible effective factors on personal exposure were recorded in a questionnaire.Results: The mean personal exposures to PM10 concentrations among bus drivers were varied in different months. Exposure to PM10 concentrations were higher in autumn and winter and increased to 300µgm-3 in some days. Personal exposures to these particles were increased in the evening and on high traffic flow routs. Other factors such as rainy weather and temperature, number of passengers, bus' model year, picking up and dropping off the passengers were the most effectiveg factors on driver's personal exposures.Conclusion: Bus drivers' exposure to respirable particles PM10 in Sari was varied in different time. It was due to entrance of outdoor particulate air pollutants into the bus during the picking up and getting off the passengers and resuspension of settled fine particles

Assesing the result of exercise test on the patients with typical and atypical chest pain referring to the Mazandaran Cardiac Center in 2007

Background: The main signs of cardiac disease (particularly the coronary disease) was chest pain and the shortness of breath. ETT is a prognostic and diagnostic tool for assessing the ischemic heart patients. The aim of present study was to determine the results of applicating ETT for patients with typical and atypical chest pain complaints referring to the Mazandaran Cardiac Center 2007. Materials and Methods: This descriptive study was conducted on 500 patients with typical and non Typical pain referring to the heart centers of Mazandaran province. After the interview, examination and laboratory tests, attended by the researcher and cardiologist, the patients under went ETT (Exercise Tolerance Test) with Tread mill according to Bruce protocol (Bruce Protocol) in four steps.Results: The present study showed the positive effect of exercise test in 80(16) of cases. The positive test results of exercise test in the cases with typical heart pain was 25 times more than the cases with atypical heart pain. 43(53.75) of the cases with positive test were male the majority of whom were (41caseses,51.25) in age range of 51-65 years. 12.5 of cases with positive test and also 78.6 with negative test had atypical pain.Conclusion: getting serious signs and symptoms of various disease serious (especially of the typical and atypical chest pain) is among the main educational priorities for the prevention of cardiac infarction

Electrochemical removal of acid red 18 dye from synthetic wastewater using a three-dimensional electrochemical reactor

Electro-oxidation degradation of acid red18 (AR18) dye from synthetic wastewater was investigated using a three-dimensional (3D) electrochemical reactor with granular activated carbon (GAC) as a particle electrode. The effect of operating parameters such as pH, current density, particle electrode dose, dye concentration and electrolysis time was studied and the optimization was performed using Taguchi fractional factorial design. The results showed that maximum removal of AR18 (96.5) and COD (84.8) were obtained under pH of 3, current density of 20 mA/cm2, initial concentration of dye of 100 mg/L, GAC dose of 250 mg/L and time of 45 min. High R2 and P value < 0.05 showed the excellent fitting of the selected model with experimental data. In addition, the experimental results showed that current density was the most important factor in the removal of the AR18 and COD. The result of comparative tests showed higher electrocatalytic activity, higher H2O2 production and lower energy consumption of 3D electrochemical reactor compared to the electrolysis process alone. The reusability and stability tests demonstrated that GAC, as a particle electrode, has a high potential for catalytic degradation of AR18 from aqueous solution at six consecutive runs. Finally, the 3D electrochemical process can be considered as a good alternative to treat wastewater containing AR18 dye. © 2019 Desalination Publications

Assessment of academic libraries in Mazandran, Goleston and Babol Medical Universities

Background and purpose: Libraries have a specific place in universities and have also an important role in students' education and research. The aim of this study was to evaluate the situation of academic libraries in Mazandaran, Babol and Golestan Universities of Medical Sciences. Materials and methods: This study is a descriptive survey in 25 academic libraries in Mazandaran, Golestan and Babol medical Universities. The tool of the survey was a standard questionnaire (ACRL), and the libraries were assessed using of checklist and interview. Results: Thirteen librarians (53%) hold a BSc degree, one (4%) with an MSc degree and two (8%) had an AA degree. Regarding to prediction and design of the libraries structure, only 40% (10 libraries) had prior programs. Related to budget, 40% relied on resources from the deputy for research, 12% on faculty current budget and 8% on hospital current budget, (40%) of others libraries did not have a planned budget). 12 libraries (45%) were open 6 days a week, 10 libraries (40%) 5 days a week and 3 libraries (12%) provided services every day. 39665 references were held at central library of Babol Medical Sciences University and less than 1016 at 5 Azar Hospital in Golestan Medical Sciences University. Fifteen libraries (60%) had access to Medline and Elsevier databases and 10 Libraries (40%) did not have any access. Conclusion: University libraries must be standardized to meet the need of the students and staff

A Study on Specific IgE Against Candida Albicans in Atopic Dermatitis Patients Referred to Boali Hospital, Sari- Iran

AbstractBackground and purpose: Candida albicans (C. albicans) as a micro flora of the human could be responsible for a continuous release of allergen and may be responsible for chronic atopic dermatitis (AD) in sensitive patients. Thus, in this study, we analyzed AD patients for total IgE and specific IgE, against C. albicans.Materials and Methods: A total of 120 AD patients (male 52 and female 68) were introduced in this study. The age range varied from 4 months to 60 years (mean about 12.9 years). Serum total IgE was assayed by ELISA kit (RADIM). Solid phase was captured by sandwich ELISA assay, using a micro well format for the determination of serum specific IgE to C. Albicans was used according to the manufacturer’s instructions, (ALerCHEK Allergen specific human IgE).Results: Of the 120 AD patients, 37 subjects (30.8%) had total IgE higher than 100 IU/mL, 44 subjects (63.7 %) 20-100IU/mL and 39 subjects (32.5%) less than 20 IU/mL. 9 (7.5%) of the patients had specific IgE against C. albicans. Among the patients who were positive for specific IgE to C. albicans, 6 (66.7%) were women.Conclusion: The result of our study on serum total IgE in AD patients is concordant with other studies from different countries. In comparison to other studies, our AD patients showed less frequency of specific IgE against Candida albicans. The explanations for the variation in the results obtained in various studies could be due to the age of patients, severity of disease, difference in the antigen preparation, different methods for IgE analysis and total IgE level

Serological survey of anti-Toxoplasma gondii antibodies in goatssheep and cattle in slaughter houses ofMazandaran province, Iran

Background and purpose: Toxoplasmosis is a widespread zoonosis caused by Toxoplasma gondii. In addition to economic losses, this disease is transfer able to human and regarding the special ecological conditions of this parasite in nature of Mazandaran province, it is necessary to determine the situation of the disease. The purpose of this study was to determine the frequency of antibodies against T. gondii in cattle, sheep and goats slaughtered in official slaughterhouses in Mazandaran province, in 2004.Materials and Methods: To determine the prevalence of toxoplasmosis in slaughtered animals, in a descriptive cross-sectional study, 639 blood samples were obtained from cattle, sheep and goats between December 2004 and April 2005, from the three main geographical zones of Mazandaran province, Iran. Nine slaughterhouses were randomly selected in Western, Central and Eastern regions. Sera were extracted from 5mL venous blood samples, by centrifugation at 2000xg for 10 min, and were stored at –20º C prior to testing. Sera were screened for T. gondii antibodies by immunofluorescence antibody test (IFAT) and serum samples showing a titre of 1:16 were further diluted to determine the end point. Data were analyzed using Chi-square (X2) test.Results: Of the 639 serum samples examined, 27.5% (176/639) showed positive titers equal or higher than 1:16 by IFAT. The highest frequency of antibody titres (1:16 titre) were found in sheep and the least in cattle (9%). The highest infection rates in cattle were seen in western region with 5.5 % antibody titres of 1:16. In three regions, 35% of sheep sera showed positive titers with high frequency of 1:16 antibody titre (17.3%) in Western region. Thirty percent of goat sera in 3 regions were seropositive and the highest infection rate was seen in 1:16 titre (18.5%) in Western region.Conclusion: The results of this study show that the presence of T. gondii specific antibodies for sheep and goats in Northern Iran is high, and the consequent risk of acquiring toxoplasmosis from human consumption of sheep and goat meat may be greater in this region