فهرست مطالب hosseini

In this note, I argue that Fine's pure logic of ground is nothing but the structural fragment of RM. This result raises a problem for discriminating between ground and relevantistic deduction in Fine's theory of ground.

Successful market entry, cost, and risk management are some of the most important challenges, facing organizations in today's highly competitive and dynamic markets. Changing attitudes toward competition on one hand and the high cost of the entrance, on the other hand, led to the formation of new concepts such as coopetition. Despite the importance, there is no comprehensive research on this issue. So the purpose of this research is to explain the coopetition model for market entry and by considering Iran's Information and Communication Technology (ICT) industry coopetition projects, it has been selected as the statistical population for this research. data gathered through two phases including systematic literature review over the past 15 years and interviews with 16 ICT experts, then data analyzed through Multi Grounded Theory (MGT). Finally and after a focus group composing of ICT experts, a conceptual model is developed about market entry through coopetition, which composed of three constructs: "coopetition antecedents", " shaping and managing coopetition", and "coopetition performance", 51 variables, 22 relates to coopetition antecedents, 17 relates to shaping and managing and 12 relates to coopetition performance.

Linear flux switching motors with simple passive segmented secondary, referred as Segmented Secondary Linear Flux Switching Motors (SSLFSMs), have low cost secondary and therefore are applicable to transportation systems like Maglev. However, it is shown that the SSLFSMs suffer from high thrust ripples. In this paper, minimizing SSLFSM thrust ripples besides maximizing its developed thrust are performed by considering the motor dimensions as design variables. Since the optimization of the motor is a high dimensional problem, a multi-level optimization method is employed to improve the machine performances and efficiency. According to the effects of the design variables on the optimization objectives, a sensitivity analysis is carried out to divide the design variables into two levels: mild-sensitive level and strong-sensitive level. Then, the two levels of design variables are optimized based on a mathematical model. Two different optimization methods as the Design of Experiment (DOE) and the Response Surface Method (RSM) are used in mild-sensitive level and the Genetic Algorithm (GA) is also used in strong-sensitive level. Based on FEM analysis, electromagnetic performance of the original motor and the optimal one are compared and the validity of the proposed optimization method is verified. Also, the effectiveness of the mathematical model used in thrust and thrust ripples calculations is evaluated and verified.

The aim of this study was to investigate the effect of different levels of replacement of full fat soybean meal with soybean meal. In this study, the average daily growth rate, feed intake, feed conversion ratio, relative weight rate, specific growth rate, carcass characteristics, meat quality, and fat oxidation rate of roast muscle were measured in Zel fattening lambs. The lambs had a mean age of three months at the initiation of fattening and a weight of 19.44±0.1 kg. At 14 weeks of experiment (two weeks of habituation and 12 weeks of fattening), the lambs were divided into four treatments (0, 33, 66 and 100% high fat soybean meal replacement, respectively) and each treatment with five replicates. The results showed that the average daily growth rate, relative weight percentage and specific growth rate increased with increasing soybean percentage. At the end of the experiment, 12 lambs (three lambs from each group) were slaughtered and in carcass dissection, weight, carcass, heart, liver, four parts stomach, the hands, thighs and the shoulder and hip carcass showed significant increase by increasing the amount of soybeans diet. Taste quality, overall acceptability and meat texture were also improved (P<0.05). By increasing the shelf life of the shelf muscle (one and two months), the oxidation rate of meat fat was significantly reduced (P<0.05). The results of this study showed that the use of high-fat soybean increased the growth performance indices in lambs and also reduced the oxidation rate and improved the meat quality indices during cold storage.

Neoerysiphe nevoi on Crepis kotschyana and Hedypnois rhagadioloides, Leveillula linariae on Linaria melanogramma and Golovinomyces asterum var. moroczkovskii on Symphyotrichum squamatum are newly reported from Iran. Nine new host-powdery mildew combinations are reported from Iran: Neoerysiphe galii − Galium aparine; Podosphaera xanthii − Phlox paniculata; Erysiphe syringae-japonicae − Ligustrum sp.; Erysiphe cruciferarum − Barbarea sp.; Golovinomyces depressus − Centaurea depressa; Golovinomyces montagnei − Notobasis syriaca; Golovinomyces orontii − Papaver somniferum; Golovinomyces cynoglossi − Lithospermum arvense; Leveillula picridis − Launaea acanthodes. The following host plants are reported as Matrix nova for their related fungal species: Crepis kotschyana and Hedypnois rhagadioloides for Neoerysiphe nevoi; Phlomis herba-venti subsp. kopetdaghensis for Neoerysiphe galeopsidis; Euphorbia hebecarpa and Papaver macrostomum for Leveillua taurica s.str.; Paracaryum rugulosum for Golovinomyces cynoglossi; Euphorbia tithymaloides for Podosphaera euphorbiae; Iranecio paucilobus for Leveillula lappae.

Calcium is one of the most important minerals involved in determining the quality of the fruit. Excessive waste and quality loss of seedless barberry (Berberis vulgaris L.) during harvesting, post-harvest, and storage are some of the important problems in production areas. Foliar application with minerals can increase the quality, yield, marketability, and reduce post-harvest losses through the provision of plant nutritional needs. Therefore, in this study, the effect of foliar application of calcium chloride and calcium nitrate on the quantitative and qualitative characteristics of barberry fruit was carried out in a randomized complete block design. Treatments included control (distilled water), calcium chloride (0.5%), and calcium nitrate (0.5%). The foliar spray was performed in four stages of the growing season. The results showed that the highest mean number of panicles per branch, the number of berries per panicle, the number of berries per branch, and the fruit yield on the branches belonged to the calcium chloride treatment and the lowest amount in the control. The calcium chloride treatment increased the fresh weight diameter and length of branch compared to the control treatment. The highest amount of chlorophylls a and b and total chlorophyll was observed in the leaves of control trees. The effect of calcium chloride and calcium nitrate treatments on the appearance quality and texture of barberry fruit was significant, although it did not affect the chemical properties of the fruit. In general, the results showed that foliar application with calcium chloride and calcium nitrate salts improved the quantitative and qualitative characteristics of the fruit compared to control.

Rosmarinic acid (RA) is considered as one of the most important polyphenols. It is an ester of 3, 4-dihydroxyphenyl actic and caffeic acids and as an antioxidant significantly reduces the DNA damage induced by the anticancer compound doxorubicin. Hairy roots of Dracocephalum kotschyi Boiss contain rosmarinic acid with biological and anticancer activities. However, due to the high production of phenolic compounds in liquid medium, the hairy roots encounter with tissue browning and death problem. In this study, the effect of antioxidant compounds on growth of D. kotschyi hairy roots and inhibition of tissue browning has been surveyed. In vitro Hairy roots were induced by inoculation of two-weeks-old cotyledons of D. kotschyi via Agrobacterium rhizogenes (15834 strain). Gene transformation confirmed by PCR using rol B gene specific primers. In order to optimize the growth and prevent the tissue browning, hairy roots were cultured in ½MS liquid medium containing different buffers and antioxidants including ascorbic acid (0.05 and 0.1 g/L), MES buffer (2.66 and 5.33 g/L), activated charcoal (1.5 and 3 g/L) and polyvinyl pyrrolidone (0.5 and 1.5 g/L) in two concentrations. In order to record the quality of hairy roots under the influence of different chemicals, the phytochemical properties of samples (total phenol and flavonoid, antioxidant activity and antioxidant enzymes activity) were analyzed by spectrophotometer. Results after 21 days showed that the maximum biomass (1.64 g) and the lowest tissue browning was obtained in ½MS media containing activated charcoal (1.5 g/L). And after AC the highest biomass was observed on both PVP concentrations (1.36 g) and the highest browning and growth loss was observed in the control samples. The maximum and minimum amount of total phenol and flavonoid were observed in control samples and 1.5 g/L of activated charcoal treatment, respectively. The highest and the lowest levels of total antioxidant activity and antioxidant enzymes were related to 1.5 g/L of activated charcoal and control samples, respectively. It is considerable that the inhibition of PAL enzyme by using antioxidants such as activated charcoal and PVP has a potential to reduce biosynthesis of phenolic compounds and prevent the browning.

Background and Objectives:

 Critical care nurses always face a lot of professional stress. Resilience is one of the most important human abilities that in tough conditions makes effective adaptability with changes and stressors. The aim of this study was to determine the association between resilience and intention to leave profession in critical care nurses.

This descriptive study was performed on 200 critical care nurses in hospitals affiliated to Birjand University of Medical Sciences by census method in 2018. To collect data, Connor-Davidson Resilience Scale )CD-RISC( and intention to leave profession questionnaire were used. Data was analyzed using descriptive and inferential statistics (Mann-Whitney and Kruskal-Wallis).

The  mean  rank  for  intention  to  leave  and  resilience  was  35.75 and  60.31. Also, there was no significant relationship between resilience and intention to leave profession (r=-0.58, p=0.261).

According to the results of this study, there was no correlation between resilience and intention to leave profession in nurses. Therefore, further inquiry into the relationship between resilience and intention to leave profession is needed. Also considering the moderate level of intention to leave profession in this current study, it is essential that nursing managers and planners attempt to reduce intention to leave profession through more support given to nurses.

Today, the intermediate band solar cell with quantum dots is one of the best options to achieve maximum solar energy conversion efficiency. In this paper, two solar cell models have been designed; the first reference model in with p-i-n structure, and the second model contains the InAs quantum dots implanted in the intrinsic region of the structure. By improving the structure and utilizing proper materials in the p-i-n reference cell, the efficiency increased by 34.03%. Then, in a quantum dot-based solar cell structure, 21.55% energy conversion efficiency improvement achieved and so that the obtained efficiency enhanced up to 55.58% by controlling the size and position of the quantum dots. In fact, the intermediate band solar cell provides a high energy conversion efficiency that have not been reported so far.

Occurrence of heavy floods in rivers causes a lot of damages and losses. In this research, to highlight the river-training reaches in 10.9 km of Babolrud River, first, using topographic map of the area, the Tin layer was created in GIS software. Then, using the HEC-GeoRAS extension, the main route and cross sections of the river were prepared and introduced to the HEC-RAS model. River discharge with return periods of 2 to 200 years was calculated. Flow analysis in the agricultural and urban areas was performed and the areas which need training measures such as flood-retaining walls and levees were specified and designed. The structural design, stability control and sliding was performed based on the Standard No. 518, using RetainWall software, and design and control of levee stability was performed based on the Standard No. 214, using GeoStudio software. The cost of project implementation was estimated based on the Price List of 2017. The output of HEC-RAS software showed that height of flood-retaining wall in 3 urban reaches ranged between 1.73 to 2.8 m and in 5 agricultural reaches ranged between 1.46 to 2.25 m. It was concluded that the overall cost of levee implementation is about 9.01 billion Rials, of gravity concrete flood-retaining wall is about 9.26 billion Rials and of concrete cantilever inverted T shape flood-retaining wall is about 10.05 billion Rials. Thus, using flood-retaining levee is the most economical option.

Civil infrastructures such as bridges and buildings are prone to damage as a result of natural disasters. To understand damages induced by these events, the structure needs to be monitored. The field of engineering focusing on the process of evaluating the location and the intensity of the damage to the structure is called Structural Health Monitoring (SHM). Early damage prognosis in structures is the fundamental part of SHM. In fact, the main purpose of SHM is obtaining information about the existence, location, and the extent of damage in the structure. Since numerous structural damage detection problems can be solved as an inverse problem based on the proposed objective functions by using optimization algorithm, in this paper, related studies are investigated which discussing objective functions based on Modal Strain Energy (MSE) and flexibility methods including Modal Flexibility (MF), and Generalized Flexibility Matrix (GFM). To illustrate the extent of effectiveness of these objective functions based on the above-mentioned modal parameters, an efficiency index called Impact Factor (IF) is defined. Finally, the best objective function is introduced for each numerical case study based on IF by means of evaluating the obtained result.

In this study, cellulose fibers were extracted from agricultural date palm waste by carrying out alkali and bleaching treatments.Cellulose NanoFibrers(CNFs) were isolated from extracted cellulose fibers with used 2,2,6,6-Tetramethyl-1-piperidinyloxy (TEMPO) pretreatment and Ball mill mechanical treatment.Then, the nanocellulose hydrogels werenanocellulose aerogels obtained.Field mission scanning electron microscopy (FE-SEM) wasused to investigate the morphology of the isolated cellulose and cellulose nanofibers. Structural analysis and functional groups was carried out by Fourier transform infrared spectroscopy (FTIR) and crystalline index determined with X-ray diffraction (XRD).The qualitative properties of nanocellulose aerogels including porosity were evaluated by BET. The results showed that cellulose fibers and cellulose nanofibers have a rod structure and formedin 3D network. After TEMPO pretreatment, it was found that the carboxyl peak formed in the 1730 cm 0 spectrum, which accelerated the nano-process. The crystallinity of the fibers and nanofibers were 71% and 68%, respectively indicating a high degree of crystallinity in their structure. After freeze drying of nanofibers, nanocellulose aerogels were obtained with weigh of about 0.5(g), low bulk density of 0.0127 (g/cm3) and very high porosity of99.16%. As a result, ultralightweight biopolymer aerogels can beused in a wide range of industries including automotive, aerospace, filtration and construction

Roads are not indispensable in forest management and without them there is no possibility of achieving different management goals and permanent access to different parts of the forest. Economic, protective and service objectives can only be achieved by building a suitable network of access roads to the forest. Since the forests of the north of the country are the only natural source for supplying the timber needed by the country's industries, the significance of these goals is significant. Therefore, the first step in the implementation of any forestry plan is to design and construct a road network with a density and appropriate coverage in the area in question. Without roads, access to most forestry products and services will not be possible, although it should be noted that the construction of a forest road has the greatest impact on forest exploitation operations, which causes the destruction of the forest environment. On the other hand, the forest road is especially important due to the heavy costs associated with design and construction as well as the negative effects on the environment and wildlife. For this reason, at all stages of project preparation and construction of forest roads, the network is being tried The road is designed and constructed to provide the least harm to the environment in addition to easy access to the entire forest level. One of the things that should be considered in designing a road is the discussion of tourist and recreation, which is a perfect road that can be used as a recreational amusement. Thus, in designing the road, it is necessary to maintain the ecological balance of the forest and to preserve biodiversity and maintain the biological bases of endangered species and to preserve the nature of the protective zones of the fishing hunting, other local recreation and economic needs, Social and Demonstration. The study method of this study was qualitative and with the review of library resources. A review of studies has shown that for designing of forest road network, all aspects have to be taken into account and all relevant factors such as physiography, soil science, geology, vegetation and socio-economic factors should be considered for conservation and Optimized productivity.

In many construction projects, cement mortar is affected by wetting-drying cycles, often due to factors such as varying rainfall, evaporation, changes in level of water in reservoirs. Alternative interactions between water and mortar affects the physical and mechanical properties of cement mortar and accelerates its erosion. Therefore, evaluating the effect of wetting-drying cycles on the physical and mechanical properties of cement mortar seems to be essential. For this purpose, a number of cylindrical and disc shaped samples were prepared. Samples were prepared for Uniaxial Compression Test, Brazilian Test, Effective porosity Test, and also determining longitudinal wave velocity. Samples were examined in cycles 0, 1, 5, 10, 15, 20 and 25. In each cycle, the samples were saturated in water for 24 hours and then dried at 105 ° C for 24 hours; then the samples were cooled at room temperature and finally examined. After cycle 25, uniaxial compressive strength, Brazilian tensile strength, modulus of elasticity and longitudinal wave velocity decreased by 37.96, 36.72, 35.44 and 8.1 percent, respectively; while porosity increased by 7.6 percent.

Electronic commerce (E-commerce) is a contemporary concept with huge potential that is fundamentally changing how business is done. This paper describes robust E-commerce strategies for trading agricultural goods and services. The purpose of this study was to enhance the efficiency of E-commerce in the export of agricultural commodities. Since the SWOT method is a key tool used by businesses to formulate strategic plans, this study conducted a SWOT analysis of E‐commerce to identify the strengths, weaknesses, opportunities, and threats faced by E‐commerce in current scenarios. A random sampling method was used to select the statistical population, which was composed of 96 experts from the Ministry of Agriculture. Seventy-five questionnaires were distributed to the experts (N= 75) using Morgan and Krejsi's table, of which 59 questionnaires were filled (n= 59). The questionnaire consisted of strengths, weaknesses, opportunities, and threats to E-commerce development and it was prepared using the Delphi technique. The important results of SWOT analysis constituted a framework to help planners and managers realize their goals and enhance the export of agricultural commodities. The resulting SWOT matrix analysis was located in the area of WO (conservative strategy). Accordingly, it is recommended that for proper exploitation of environmental opportunities, organizational weaknesses should be taken into account. Some important strategies suggested based on this study are enforcing laws and providing effective incentives to reduce production costs relative to global prices as well as creating innovation in the export process using E-commerce.

Avian influenza (AI) is an acute infectious disease with worldwide significance causing extensive economic losses in the poultry industry. Avian influenza viruses (AIVs) belong to the family Orthomyxoviridae and categorized in the genus influenza virus A. These viruses have been isolated from more than 100 species of free-living birds. Migratory birds are considered as reservoirs for AIVs and are the major agents responsible for global outbreaks. The Passeriformes are found in most parts of the world and cover a variety of habitats from rural to urban areas. House sparrows are members of the family Passeridae and due to their free flying, are strongly associated with seabirds, indigenous, and industrial poultry. The aim of this study was to determine the role of house sparrows in AIV (H9N2) circulation in the Ahvaz region. The intestinal and tracheal samples were taken from 200 sparrows around Ahvaz during 2017. Reverse transcriptase-polymerase chain reaction (RT-PCR) was performed using specific primers in order to detect M and H9 genes of AIVs. The positive specimens in the PCR for the M gene were inoculated into 9-11-day-old embryonated chicken eggs via the allantoic fluid. The results showed that 11 out of 200 samples were positive for the two genes of M and H9. According to the findings of the present study, house sparrows are infected with H9N2 and pose a threat to commercial poultry. These birds may play a significant role in the transmission of AIV between wildlife and domestic animals. Therefore, this issue is important to be considered in preventive measurements.

Wives of veterans, due to close relationship and taking care of them, are identified as secondary or hidden victims of trauma. This indirect exposure to a stressful event brings psychological consequences for them.

The current study aimed at determining the relationship and predicting role of sleep quality and sexual self-esteem in secondary post-traumatic stress disorder among wives of veterans.

The present descriptive-analytical study was performed on 152 wives of veterans with secondary post-traumatic stress disorder in Kermanshah Province, Iran in 2019. The subjects were selected by purposive sampling method. To collect data, the Pittsburgh sleep inventory, sexual self-esteem index for woman-short form (validation by Farokhi & Shareh), and secondary trauma questionnaire (STQ) were used. Data were analyzed by SPSS version 25 using Pearson correlation coefficient and simple linear regression.

According to the findings, the mean ± standard deviation scores of sleep quality, sexual self-esteem, and secondary traumatic stress disorder were 13.00±3.88, 59.11±11.88, and 63.43±10.53, respectively. The results indicated a positive and significant relationship between low sleep quality and secondary traumatic stress (r= 0.345, P<0.01). In addition, there was a significant and negative correlation between sexual self-esteem and secondary traumatic stress (r = -0.298, P<0.01). The results of regression analysis showed that 32% of changes in secondary traumatic disorder can be explained by sleep quality and sexual self-esteem.

Given the important role of sleep quality and sexual self-esteem in the predicting secondary traumatic stress disorder, it is suggested to consider the role of these factors in intervention programs for secondary traumatic stress disorder.

Ammonium Perchlorate (AP) is one of the most important oxidizer in composite solid propellants. Therefore, synthesis and application of nanoparticles as catalyst for improving thermal decomposition of AP is an important issue in catalysis research. There are a lot of nanomaterials for the thermal decomposition of AP such as nano metal particles, metal oxides, metals salts, and organometallic compounds. In recent years, in order to enhance catalytic activity, nanoparticles deposited on the carbon supports (Such as carbon nanotubes, graphene, graphene aerogels, etc.)to increase active surface and prevent agglomeration of nanoparticles. The synergistic effect between nanoparticles and supports based carbon can enhance catalytic activity . These additives can enhance the burning rate and combustion efficiency of the corresponding solid propellants by changing the thermal conductivity, energy barrier of thermolysis, heat of reaction, and gas-phase reaction mechanisms of the main ingredients of AP. In this paper, the effects of nano metals and nano metal oxides on the thermal decomposition of AP are reviewed and then the effect of these additives on supports based carbon is investigated.

Gamma Coronaviruses (GCoVs) are distributed worldwide, affecting a wide range of bird species, the beluga whale, and bottlenose dolphins. Because of the limited proofreading capability in the viral encoded polymerase, they emerge genetically diverse. There has been no molecular surveillance data to describe the epidemiology of GCOVs in avian species. The present study was conducted to detect GCOVs in Tehran birds’ parks, 2015. Cloacal swabs (267 samples) from eight  different bird species ((Chickens (Gallus gallus), Pheasant (Phasianus colchicus), Turkey (Meleagris gallopavo), Partridge (Perdix perdix), Quail (Coturnix coturnix), Duck (Anas platyrhynchos), Goose (Anserini),and  Guinea fowl (Numididae)) were collected, the viral RNA was extracted, the RT-PCR was performed using QIAGEN one step RT-PCR kit and the primers targeting “3'-UTR” and “Nucleocapsid” genes. The detection rate was approximately 8.99%. GCOVs were detected in the chicken, quail, pheasant, turkey, and the partridge with different prevalence rates. Phylogenetic tree based on partial nucleotide sequences of the N gene clustered the samples into two groups. It is the first report of GCOVs in non-commercial birds in Iran.  According to our results, GCOVs are circulating in different avian species, and further studies are needed to isolate these viruses and evaluate their pathogenesis.

The SPTBN4 gene, a part of the spectrin protein family, plays important roles in various cellular processes, including cell cycle, nerve cell development, and so on. Recently, a new miRNA has been found in this SPTBN4 gene, which was registered at the NCBI database. The aim of the present study was to investigate the expression of this miRNA, called SPTBN4-miR1, in the process of differentiation of human embryonal carcinoma cell line NT2 and also the overexpression effect of this miRNA on the differentiation of these cells. RT-qPCR results indicate that SPTBN4-miR1-5p and SPTBN4-miR1-3p show a significant increase in expression in the process of neural differentiation from day three until the 8th and 14th day of differentiation. Then, after overexpressing the SPTBN4-miR1 precursor in NT2 cells and retinoic acid treatment, the expression of pluripotent and differentiation revealed the role of SPTBN4-miR1-5p and SPTBN4-miR1-3p in promoting differentiation and exclusion from the pluripotent state. It seems that by making further studies and finding out the possible targets of these miRNAs, a distinctive marker can be achieved and used to improve the differentiation process.

 Health is one of the fundamental rights of every human as well as it is a social aim and all governments are responsible for people’s health. This study aimed to investigate the physical and mental health and its related demographic factors in martyr's elderly parents.

 This cross-sectional descriptive study was carried out on martyr’s elderly parents in Tehran, Iran in 2018. 600 individuals were selected by stratified random sampling method. Data collection was conducted using a demographic questionnaire, the activities of daily living (ADL) questionnaire and world health organization (five) well-being index (WHO-5). Data were analyzed by SPSS 23 software through independent t-test, one-way analysis of variance and Tukey’s post-hoc test.

 The mean scores obtained for the activities of daily living was 10.07±3.17 and the mean scores obtained for world health organization (five) well-being index was 11.60±5.87. There was a significant relationship between the ability to doing activities of daily living and mental well-being with demographic characteristics including age, gender, marital status, ability to read and write and the number of income sources (p<0.05).

 Physical and mental health status of martyr's elderly parents in Tehran city is in the low level and it has a relationship with demographic characteristics including age, gender, marital status, ability to read and write and the number of income sources.

This paper presents a novel impedance-based approach for out-of-step (OOS) protection of a synchronous generator. The most popular and commonly used approaches for detecting OOS conditions are based on the measurement of positive sequence impedance at relay location. However, FACTS devices change the measured impedance value and thus disrupt the performance of impedance-based relay function. In this paper, the performance of synchronous generator OOS protection function connected to the transmission line in the presence of a static synchronous compensator (STATCOM) is investigated. Moreover, an analytical adaptive approach is used to eliminate the effect of STATCOM. This approach requires only the remote bus voltage and current phasors to be sent to the relay location via a communication channel. Simulation results show that STATCOM changes impedance trajectory and causes the incorrect operation of OOS relay. Furthermore, the proposed approach corrects the relay mal-operation and improves the accuracy of OOS impedance-based function when the STATCOM is used in the system.​

Listeria monocytogenes, as a foodborne pathogenic bacterium, is considered as major causative agent responsible for serious diseases in both humans and animals. Milk and dairy products are among the main sources of energy supply in the human, therefore contamination of these products with Listeria spp., especially L. monocytogenes, could lead to life threatening infections in a large population of people. Rapid and accurate detection of L. monocytogenes in milk and dairy products, vegetables, meat, poultry, and seafood products is needed to prevent its dissemination through the food chain. Upon contamination of food materials with this pathogen, increase in its antibiotic resistance rate can occur after exposure to preservatives, antibiotics, and stress conditions, which has now become another major public health concern emphasizing the need for special attention on its control along the food chain and management of the disease in the patients. This review provides an overview of researches with respect to the prevalence of Listeria spp., especially L. monocytogenes, in milk and dairy products, methods of their detection and typing, and current status of resistance rates to the antibiotics used for treatment of listeriosis.

Potassium nitrate as oxidant is one of the main components in the some pyrotechnic compounds. This salt is the cheapest amongst the alkali nitrates and naturally available that widely used in pyrotechnic compounds of infrared, flare and delay compounds. Consequently, the investigation its thermal properties have considerable significance such as thermal stability, lifetime, enthalpy, deflagration thermal, thermal decomposition kinetics, etc. are of great importance. In order to estimate these properties, thermal analysis methods such as thermogravimetric analysis, differential scanning thermometry and differential thermal analysis are used. The thermal stability of the composition depends on the amount, type and size of the oxidizing particles and the type of fuel.In orther to, in this paper, a review will be made of the thermal behavior of potassium nitrate form pure and in pyrotechnic mixtures as oxidizing agents in the presence of various fuels (silicon, boron, iron, lactose, aluminum, tin and zirconium). Finally, the effect of heating rate, particle size, aging and also the presence of other nitrates on the thermal behavior of pyrotechnic mixtures containing potassium nitrate will be investigated.

Sleeping is an essential part of living and poor quality sleep can lead to a variety of physical and mental disorders. On the other hand, job stress is one of the main effective factors in reducing productivity in organizations and causing physical and mental complications in personnel. The aim of this study was to determine the job stress and its association with sleep quality among employees of Bid Boland Gas Refinery, Behbahan, Iran.  

In this descriptive study, 180 employees of Behbahan Bid Boland Gas Refinery participated in 2017. The data were collected using the Osipow occupational stress questionnaire and Pittsburgh sleep quality index questionnaire. To analyze the data, descriptive statistics, independent samples t-test, one-way ANOVA, Pearson's correlation coefficient and multiple linear regression analysis were used.

The results of the study showed that the mean and standard deviation of job stress and sleep quality perceived by employees were 167.27±19.66 and 10.72±2.22, respectively. Furthermore, there was a positive significant correlation between these two indexes (p<0.001). The regression model demonstrated that sleep quality was significantly associated with "role insufficiency" ( =0.499, p<0.001) and "role boundary" ( =0.197, p=0.035), the dimensions of Osipow job stress questionnaire. The model coefficient of determination indicated that 30.6% of sleep quality index changes are specified by variables of role insufficiency and role boundary.

The results showed that there was a significant correlation between job stress and sleep quality. Therefore, it is recommended to the gas refinery authorities to design and perform some plans for reducing job stress and sleep quality problems.

This research was funded by Behbahan Faculty of Medical Sciences. Conflict of interest: None declared.

 The Ethics Committee of Behbahan Faculty of Medical Sciences approved the study. (IR.BHN.REC.1395.18) How to cite this article: Asadi N, Hosseini SS. Study of Job Stress and Its Association with Sleep Quality Among Employees of Behbahan Bid Boland Gas Refinery in 2017: A Descriptive Study. J Rafsanjan Univ Med Sci 2019; 18 (8): 797-810. [Farsi]