An Investigation of the Effect of Ventilation Inlet and Outlet Arrangement on Heat Concentration in a Ship Engine Room

Τhe ventilation in the ship engine rooms is an essential issue concerning finest performance of engines and diesel generators as well as electric motors. The present study has aimed at the analysis of temperature distribution inside the ship main engine room. In the same way, attempts have been made to identify those points with considerable thermal concentration in main engine room space, so that proper ventilation systems could be engineered and utilized and favorable thermal conditions could be realized. The CFD approach has been utilized in order to analyze impact of the designed ventilation system on the temperature distribution pattern. The Inlet layout and area have been analyzed under a variety of scenarios in order to decrease the average temperature and eliminate the heat concentrations in various points of the engine room. The temperature distribution and location and area of ventilation air inlet have been studied in different modes resulted in temperature distribution pattern, heat concentration outline and average volumetric temperature level in each mode. The results indicated that considerable circulating air volume is required compared to those levels suggested by common practices, calculations and standards in order to eliminate the heat concentration

Construction of Novel Phytochelatins by Overlap Oligonucleotides

Synthetic phytochelatins are protein analogs of phytochelatin with similar heavy metal binding affinities that can be easily produced from a synthetic DNA template. We design synthetic phytochelatin [(Glu-Cys)n Gly] linked to hexahistidine by viral linker peptide and then followed by gene synthesis and cloning of it. Then peptide coding gene (synthetic phytochelatin with linker and hexahistidine) was designed exactly and constructed with step by step methods by overlapping oligonucleotides using T4 DNA Ligase. Finally, synthesized gene amplified by PCR, cloned in pTZ57R/T and transformed to Escherichia coli (DH5α). The results of sequencing show that some types of synthetic phytochelatin (EC4, EC12, and EC20) with linker and hexahistidine were constructed and cloned in vector

Quantitative characteristics and chemical composition in Caspian roach (Rutilus rutilus caspicus) sperm

In this study, quantitative characteristics and chemical composition of in roach (Rutilus rutilus caspicus) sperm were investigated. Sperm traits included sperm movement duration, percentage of motile spermatozoa, sperm density, spermatocrit and sperm volume. Some seminal plasma characteristics (sodium, potassium, calcium, magnesium and chloride) were investigated. In addition, some metabolites of seminal plasma (glucose, cholesterol and protein) were measured. The Na+ and K+ ions correlated negatively with spermatozoa motility (r = -0.0518, p<.05 and r =-0.3597, p<.01) respectively. Also, there were significant positive correlations between Ca2+ and Cl- ions with spermatozoa motility (r = 0.2945, p<.05 and r= 0.1379, p<.01), respectively. Mg+2 was positively correlated with glucose and protein (r = 0.046, p<.05 and r = 0.694, p<.05), respectively. On the other hand, a significant positive relationship was found between Na+ and K+ (r = 0.548, p<.01). These parameters can be used to evaluation of sperm quality and collecting information about developing procedures for artificial fertilization of roach

Estimation of genetic parameters for body weight at different ages in Mehraban sheep

The objective of the present study is to estimate genetic parameters of birth weight (BW, n = 3005), weaning weight (WW, n = 2800), 6 months weight (6 MW, n = 2600), 9 months weight (9 MW, n = 1990) and yearling weight (YW, n = 1450) of Mehraban sheep, collected during 1995 - 2007 at Mehraban sheep Breeding Station in Hamedan province, Iran. (Co)variance components and genetic parameters were estimated with univariate and multivariate animal model using restricted maximum likelihood (REML) procedure. Effect of herd, lamb's sex, and year of birth were significant on all traits (P &lt; 0.05). The estimates of direct heritability for BW, WW, 6MW, 9MW and YW were 0.30±0.05, 0.30±0.04, 0.35±0.05, 0.37±0.04 and 0.43±0.04 respectively. Maternal heritability estimates for mentioned traits were 0.17±0.03, 0.18±0.03, 0.14±0.03, 0.12±0.03 and 0.10±0.02, respectively. The estimates of the direct genetic correlation between BW-WW, BW-6MW, BW-9MW, BW-YW, WW-6MW, WW-9MW, WW-YW, 6MW-9MW, 6MW-YW and 9MW-YW were 0.287±0.09, 0.305±0.09, 0.249±0.03, 0.136±0.07, 0.825±0.34, 0.713±0.05, 0.845±0.52, 0.862±0.06, 0.596±0.09 and 0.712±0.02 respectively. The estimates of the phenotypic correlation between traits were positive and ranged from 0.152 for BW-9MW to 0.835 for 9MW-YW.Key words: Mehraban sheep, heritability, genetic correlation, body weight traits

Comparative antibacterial effects of essential oils of Melissa officinalis and Deracocephalum moldavica L. against some pathogenic bacteria in food in vitro

زمینه و هدف: استفاده از نگهدارنده&zwnj;های شیمیایی و مضرات آنها، سبب شده که تولید کنندگان مواد غذایی اخیرا گرایش به استفاده از نگهدارنده&zwnj;های طبیعی در مواد غذایی پیدا کنند. اسانس&zwnj;های گیاهی که همان روغن&zwnj;های فرار (volatile oils) می باشند، روغن&zwnj;های مایع و معطر گیاهان اند. گیاهان معطر حاوی اسانس هایی با خواص ضد میکروبی هستند. در این مطالعه اثرات ضدباکتریایی اسانس&zwnj;های بادرنجبویه (Melissa officinalis) و بادرشبو (Dracocephalum moldavica) علیه 4 باکتری بیماریزای مواد غذایی در شرایط آزمایشگاهی بررسی شد. روش بررسی: در این مطالعه تجربی پس از تهیه باکتری های مورد بررسی، با روش انتشار بر روی دیسک قطر هاله ممانعت از رشد و با روش میکرودایلوشن حداقل غلظت ممانعت از رشد و حداقل غلظت کشندگی برای هر دو اسانس بادرنجبویه و بادرشبو تعیین شد و جهت مقایسه نتایج از نرم افزار SPSS با آزمون T test استفاده گردید و سطح اختلاف معنی دار کمتر از 0/05 انتخاب شد(P&lt; 0/05). یافته ها: نتایج این مطالعه بیانگر تاثیر ضد میکروبی قوی دو اسانس فوق روی این باکتری ها بود. باکتری استافیلوکوکوس اورئوس با حداقل غلظت ممانعت کنندگی mg/mL 1/2 (برای هر دو اسانس) حساس&zwnj;ترین باکتری در مقابل اسانس&zwnj;های بادرنجبویه و بادرشبو بود. در این میان اسانس بادرنجبویه اثرات ضد باکتریایی قوی&zwnj;تری علیه باکتری&zwnj;های مورد آزمایش در مقایسه با اسانس بادرشبو داشت. نتیجه گیری: نتایج حاصل بیانگر توان مهارکنندگی و ضد باکتریایی اسانس های بادرنجبویه و بادرشبو علیه این میکروارگانیسم های بیماریزا می باشد که می تواند بعنوان یک ماده ضد میکروبی گیاهی، جایگزینی مناسب برای ترکیبات شیمیایی ضد باکتری باشد و در صنایع غذایی و داروسازی مورد استفاده قرار گیرد

Interacting Cosmic Fluids in Brans-Dicke Cosmology

We provide a detailed description for power-law scaling FRW cosmological models in Brans-Dicke theory dominated by two interacting fluid components during the expansion of the universe.Comment: 13 pages, 8 figure

Marshall syndrome in children referred to specialist clinic of Imam Khomeini Hospital of Ilam, Iran, 2012

Periodic fever syndrome is a self-inflammatory disease. Since the disease is benign and self-limiting, the present study aimed to achieve a model to detect and differentiate it from other infectious diseases .In this study all children residing in Ilam who were suspected of Marshall Syndrome were examined. We chose a sample comprising children referred to Imam Hospital clinic of Ilam in 2012. Inclusion criteria consisted of more than three periods of fever without a source of infection, fever periods shorter than 5 days and repeated at intervals of about one month. The collected data were analyzed using SPSS software 16. We used both of descriptive and inferential statistics, Kolmogrov smirnov, Chi-square. Significance level of P ≤ 0.05 was considered. The average of patients' age was 4.9 ± 1.8 months and their gender perception was 85.7 male and 14.3 female. In this study the average age of symptoms emergence was 48.33 ± 23.25 month. The average of fever periods in surveyed patients was 4.09 ± 0.88 days (minimum 3 days & maximum 5 days) and the intervals between fever periods was 40.23 ± 16.84 in average. The applied treatments in this study were Prednisolone and Ttonsillectomy. There was significant relationship between age and the symptoms (P<0.007). By having a true perception of Marshall Syndrome using diagnosis criteria, we could prevent uncontrolled prescription of antibiotics and their possible side effects, and it is a positive step towards reducing healthcare costs

Not gendered...but different from each other? A structural equation model for explaining risky road behaviors of female and male pedestrians.

As alternative transportation is getting more and more fashionable, and more people worldwide are 'shifting' to walking trips, even for their daily commuting, traffic crashes suffered by pedestrians are still a great concern for road safety and public health researchers and practitioners. In this regard, risky or 'aberrant' road behaviors have emerged, during the last few years, as a key issue to be considered for crash prevention. Nevertheless, the idea of a 'generic pedestrian' is getting re-evaluated, and analyzing key features, such as gender, seems to be crucial for understanding pedestrians' performance and safety outcomes. Objective: The objective of this study was to examine the effect of gender on pedestrians' both deliberate (traffic violations) and undeliberate (errors) risky walking behaviors, considering a set of theoretically based demographic and psychosocial variables as their potential predictors. Method: For this cross-sectional study, data from 1070 Spanish pedestrians (60 % females and 40 % males, aged between 16 and 79) from the 17 regions of Spain, responding to an electronic questionnaire, were analyzed through a multi-group structural equation modeling (MGSEM) approach. Results: Although age, handheld device-interaction, and sensation-seeking seem to have a similar effect on the errors and violations reported by both genders (similarities), factors such as risk perception, educational level and the misbehaviors observed in other road users are significant predictors only in the case of male pedestrians. On the other hand, road distractions have been shown to play a significant role in females' errors and violations, while males' road distractions seem to only affect their involuntary risky behaviors. Conclusion: The findings of this study support the influence of gender in the statistical explanation of both deliberate and undeliberate walking risky road behaviors, also depicting the differential role of certain demographic and psychosocial factors when we compare male and female pedestrians

Knowledge, Attitude, and Practice toward Prevention of COVID-19 Among Nursing and Midwifery Students: A cross-sectional Study in Gorgan, Northern Iran

Background: Healthcare providers are high-risk groups for the novel coronavirus disease (COVID-19) infection. Nursing students are an essential part of high-risk healthcare providers. The aim of this study was to evaluate the knowledge, attitude, and practice of nursing and midwifery students at Golestan University of Medical Sciences (GOUMS) toward the prevention of COVID-19. Methods: This cross-sectional study was conducted on 174 nursing and midwifery students of GOUMS (northeast of IRAN) in 2020. Data were gathered using an online questionnaire comprising three parts – Knowledge (8 questions), Attitude (10 questions), and Practice (8 questions) toward the prevention of COVID-19. The range of scores in each subscale (knowledge, attitude, and preventive practices) were 8–24, 10–50, and 8–24, respectively. Data were analyzed using the SPSS v.16 software. The Mann–Whitney and Kruskal–Wallis tests were used for the analysis. Results: Overall, in this study, nursing and midwifery students had a good knowledge (mean score: 23.19 ± 2.56), a positive attitude (mean score: 45.48 ± 4.21), and appropriate practice (mean score: 23.30 ± 3.51) regarding COVID-19 prevention. Also, the results revealed a positive correlation between knowledge and attitude (r = 0.1, P = 0.18) and attitude and practice (r = 0.2, P = 0.01) among the students. Conclusion: The findings demonstrated a good preventive knowledge, attitude, and practice toward COVID-19 among nursing and midwifery students