فهرست مطالب a. . mohammadi

Based on the theory of Relative Deprivation, children who feel relatively deprived have lower expectations from their parents. To discover what factors affect the parents-related expectations of adolescents in South Khorasan Province, a cluster sample of 580 students, aged 13-18 years, was given a questionnaire of assumed validity and reliability on deprivation and expectation. Data analyses revealed that mean scores on generational gap, peer group, and sensing relative deprivation are higher than other factors, i.e. parental control over children, media usage, parental life style, and children’s consumerism. While the mean score for expectation was 59.1, it showed a positive and significant correlation with generational gap, children’s consumerism, parental life style, peer group, and media usage. The correlation between expectation and relative deprivation and parental control of children was significantly negative.

In this research, polystyrene-poly (ethylene glycol)-polystyrene (PS-b-PEG-b-PS) amphiphilic triblock copolymer was synthesized by atom transfer radical polymerization (ATRP) method. The results of FTIR and NMR analyses were confirmed the successful synthesis of the presented triblock copolymer. The experiments of hydrate inhibition performanc testing were carried out in the presence of methane gas using rocking-cell reactor at initial pressure of 68 bar and 1.5oC, respectively. The potential kinetic inhibitory effect of synthesized PS-b-PEG-b-PS copolymer was investigated at the conectrations of 0.05 and 0.1 wt% and compared with the similar data of commercial inhibitors including polyvinylpyrrolidone (PVP) and Luvicap EG as a polyvinylcaprolactam (PVCap)-based kinetic inhibitor from BASF. The obtained results showed that the synthesized PS-b-PEG-b-PS at concentration of 0.1% wt had about 92% inhibitory performance, while PVP as a commercial inhibitor had up to 84% inhibitory performance. Furthermore, the rate of gas consumption in the presence of the synthesized PS-b-PEG-b-PS was decreased about 6 times compared to Luvicap EG and 2 times less than to PVP one. The synthesized amphiphilic triblock PS-b-PEG-b-PS copolymer by ATRP method could be introduced as a new potential kinetic gas hydrate inhibitor.

This study aimed to develop and validate a model for predicting productivity in university administrative staff.

In this cross-sectional study, 614 participants completed a survey that included the Job Stress Questionnaire, Job Security Scale, Role Clarity Scale, Distributive Justice Subscale, Procedural Justice Subscale, Job Content Subscale, Physical Health Questionnaire, Depression, Anxiety, and Stress Scale, and Stanford Presenteeism Scale. To validate the proposed model, structural equation modeling was conducted using SPSS 23 and AMOS 23 software.

Distributive justice, job content, and procedural justice had the greatest direct impact on employee productivity. Additionally, workload, colleague support, management support, role clarity, and procedural justice were found to have significant positive relationships with mental health. Workload, management support, and job content also showed significant positive relationships with physical health, and both mental health and physical health positively predicted presenteeism. The findings revealed a mediating pathway in the relationship between mental health, physical health, and productivity. The data further suggested that mental health has a substantial impact on physical health. Moreover, mental health was found to mediate the relationship between job stressors and presenteeism through its effect on physical health.

Psychosocial factors, including distributive justice, job content, and procedural justice, have the greatest impact on employee productivity.

The present research was conducted with the aim of exploring and explaining organizational factors affecting third-party liability insurance violations in the Iranian insurance industry.

The current study is based on a descriptive-exploratory mixed methodology. The statistical population of the qualitative part of the study includes experts from the fields of insurance management and economic sociology and development. The survey was conducted using a purposive and snowball sampling method of 26 experts until saturation. The statistical population of the quantitative part of the study included employees of Tehran insurance companies. A total of 354 people were selected as a statistical sample using a cluster sampling method. The instrument for data collection was semi-structured interviews with experts in the qualitative part and questionnaires in the quantitative part. The validity of the questionnaire was confirmed by form and content methods and its reliability by the Cronbach's alpha method. The data from the qualitative part of the study was analyzed using the thematic analysis method and the data from the quantitative part using confirmatory factor analysis with the Amos21 software.

Based on the results of the qualitative part, a total of 52 basic themes, 18 organizing themes and 5 inclusive themes (organizational justice, organizational commitment, informal organization, organizational culture and legality) were identified. According to the results of the quantitative part, organizational justice and organizational commitment have a negative and inverse effect with -0.84 and -0.56, respectively, and the variable of informal organization has a positive and direct effect with 0.54 on the violations of employees of insurance companies operating in the field of third-party liability insurance. The variable of organizational justice had an effect on the violations of insurance company employees through the influence on organizational commitment and informal organization.

Based on the research findings, it is suggested that the organizational factors presented in this study should be considered in the strategic plans of the insurance industry in addressing insurance violations and should be emphasized by insurance companies. In the area of organizational justice, it is suggested that in order to restore organizational justice, the mentioned values should be considered among the employees of the insurance companies and the implementation of justice in the organizational processes. In terms of organizational commitment, it is suggested that the dimensions of organizational commitment considered in this research should be considered as a basis for improving the organizational commitment of employees. In relation to informal organization, it is also suggested that if there is a positive attitude towards informal organizations, their existence should be used in line with the objectives and strategies of insurance companies.

The identification of principles and methods of social training that are based on three sociological approaches of holistic, reductionist, and combinatory requires the combination of introductions and realistic descriptions of both the ultimate goals and methods in these three approaches. Using William K. Frankena’s method of reconstructed practical comparison the following sets of principles and methods were drawn: Holistic principles of cooperation, group participation in training activities, creation of equal opportunities for all students, and strengthening the spirit of empathy with members of the society and methods such as group investigations; Reductionist principles of the development of students’ personal identity, their freedom of choice throughout the educational process, and preparation of opportunities for the development of their wisdom as well as methods value clarification and doing personal projects; Combinatory principles of identification and attention to students’ interests and needs, as well as preparation for creation of social norms, as well as methods like interaction and inquisitive confrontation.

One of the criteria for the progress of science production in academic societies is to write a scientific-research article. The publication of scientific-research articles in the contemporary period is a good opportunity to share the findings of researchers and inform the audience about the latest scientific achievements. Despite the quantitative growth of the publication of such articles in the last decade, not enough attention has been paid to their evaluation and criticism. In the field of Persian language and literature, one of the fields of research is the examination of the texts of mystics and mystics such as Hafez, Sana'i, and Molavi. In the meantime, Molavi is one of the people who have written many scholars about his opinions and thoughts and have shown his views according to his works. Among Maulavi's works, his spiritual Masnavi has a special place in introducing Maulavi's thoughts and many articles have been written about Maulavi. The purpose of this essay is to review and analyze these works due to their large volume.

In this article, 355 scientific-research articles published on Masnavi, in various academic and non-academic publications in Persian language from 2001 to 2013, with a descriptive-analytical method in two forms, the time of publication and the subject of the articles under review, review and classification It has been classified and the weak points of these articles have been examined in terms of structure.

In many of these articles, there are shortcomings and disadvantages such as the inconsistency of the title with the content, the disproportion of the abstract of the article, inattention or lack of attention to the background of the research, the use of inappropriate language, the descriptive and superficial nature of the articles, the lack of approach to analytical research, there is the repetitiveness of the subject, and the imposition of meaning on the text.

From the examination of the mentioned damages, it can be concluded that despite the large number of articles about Maulavi's Masnavi in the period of 2001 to 2013, the quality of these articles is not very favorable and since some of these damages are affecting the articles published in There are also academic and scientific-research journals, it is hoped that with the implementation of reform approaches and more accuracy of journals in accepting and publishing works, Masnavi's articles will be of better quality.

The theory of learned helplessness was presented by Martin Seligman in the late 60s and the early 70s. According to this theory, the previous mental learning had a tremendous impact on future performance. Learned helplessness is a cognitive process that teaches people that staying in such a state leads them to passivity and inactivity, and can keep people stuck in the quagmire of backwardness. Previously, some authors presented articles on the theory of learned helplessness and development, but in this article, the connection between the two and the effect that learned helplessness has on self-concept is discussed. The purpose of this article is to identify the factors that play a role in the lack of development of societies in order to guide them to the path of development by raising developed people. In this research, there is a kind of correlation and causal relationship between two variables: the independent variable - the role of learned helplessness - on the dependent variable - development process. The method of collecting data is in the form of library and documentary studies. The difference between the real self and the ideal self is the beginning of tension and intellectual conflict, and such a process is associated with the thinking that no matter how much effort is made to get out of helplessness, success and progress will not be achieved, and this is exactly the basics that Seligman teaches us in Learned Helplessness.

In this research, a spectrum variety of AUSM-family, including AUSM+, AUSM+UP, SLAU, and AUSM+M, in a numerical framework, based on the finite volume method to solve preconditioned two-dimensional Eulerian equations, was developed in an unstructured grid and the performance of this family has been investigated in incompressible flow. Where fluid velocity is low, convergence rate of density base solvers is distorted. Turkle's preconditioning method based on the conservation variable has been utilized to remedy the poor convergence at low speeds flows. In addition, at low speeds, the imbalance between the elements in this family's convective and pressure fluxes results in a deterioration of accuracy. Therefore, the necessary mathematical literature has been developed to solve the imbalance problem raised at the low speeds of the AUSM family. In addition, to further accelerate the convergence rate and reduce the stiffness of the equations at low speeds, the time part of the equations has been discretized utilizing the modified second-order Bashforth-Moulton method. To investigate the accuracy and efficiency of the developed AUSM family, steady two-dimensional inviscid tests around the NACA0012 airfoil, three-element 30P-30N airfoil, and half-cylindrical have been constructed for a wide range of low and highly- low Mach numbers. The results show no optimal trade-off between convergence rate and accuracy improvement within AUSM family. The accuracy improvement is not accompanied by reduced convergence time necessarily in low velocity flow field.

In order to improve the process of selection and appointment of ministerial administrators in education, the design, and validation of a competency model was deemed necessary. To this end, a sample of 22 experts was interviewed and their responses were content analyzed. Additionally, a sample of 86 ministerial administrators from among 115 such individuals in Tehran were given a questionnaire with an acceptable validity. These data were analyzed through factor analysis. Results brought about an initial list of 63 competencies of which 58 were confirmed through factor analysis. These competencies are categorized in two dimensions of general and special with six main categories and 17 subcategories.

Gas hydrate formation is a new technology to uptake carbon dioxide. In the present work, the kinetics of changes in the volume of unreacted water, the formed carbon dioxide hydrate, and also the unreacted gas inside the reactor were investigated with the passage of time. Experiments were performed in a stagnant 169 cm3 double-walled reactor at a temperature of 275.15 K and a pressure of 3 MPa. The tests were done by using the isochoric-isothermal method. The results of the experiments showed that the volume of unreacted water decreased with respect to time and the volume of hydrate formed increased. Taking into account the different molar volumes of hydrate formed and the molar volume of reacted water in the test conditions, the changes in gas volume inside the reactor were calculated with the passage of time. The gas volume inside the reactor decreased from 144 cm3 at the beginning of the process to 141.62 cm3 at the end of the reaction. By decreasing the pressure during carbon dioxide hydrate formation process, the amount of hydration number increased from 6.047 mol/mol to 6.109 mol/mol.

In this research, the effect of adding SiC nanoparticles on the hardness and wear behavior of A380 aluminum alloy was investigated. A380 aluminum powder and SiC nanoparticles with values of 0, 0.5, 1, and 2 wt.% were ground in a planetary ball mill in argon atmosphere for 10 hours. The weight ratio of ball to powder and the rotation speed was adjusted at 1:10 and 250 rpm, respectively. After the milling process, a hot press was used to produce the samples. The products were produced through a graphite mold with a diameter of 15 mm at a heating rate of 10 °C/min to a final sintering temperature of 520 °C and a holding time of 30 minutes in vacuum under pressure of 50 MPa and were placed in the hot press machine. The microstructure and hardness of the samples were examined using an optical microscope and Vickers hardness tester apparatus, respectively. The wear resistance was evaluated by pin-on-disk method. The greatest hardness of the samples was related to the aluminum alloy containing 0.5 wt.% SiC nanoparticles. AlA380-2 wt.% SiC nanocomposite represented the highest wear resistance compared to the other experimented samples.

The permissible exposure time to vibration for the operator is one of the key factors in maintaining the operator's health while optimizing machinery and equipment. The tractor studied was the ITM475, manufactured in Iran. The purpose of this study was to calculate the operator's permissible vibration exposure time while using the tractor to ensure the driver can maintain good bodily health.

In this study, experiments were conducted using a 3-axis vibration meter based on the ISO 2631 standard. The obtained data were analyzed through a factorial experiment using 18 treatments and 3 replications. The factors studied were engine rotation speed (at three levels of 1000, 1500, and 2000 rpm), road type (dirt and asphalt), and gear position (at three levels of 1, 2, and 3).

Various total vibration models were obtained for the tractor, and their determination coefficient varied from 90.11% for gear No. 3 on an asphalt road to 100% for gear No. 1 on an asphalt road and gear No. 2 on a dirt road. The maximum whole-body vibration, and consequently the minimum permissible exposure time, was observed for gear No. 3 at an engine rotation speed of 2000 rpm on a dirt road, which was 1.49 and 1.16 hours, respectively.

The maximum whole-body vibration experienced during an 8-hour tractor-driving session was measured at 0.85 m s-2. It is important to note that the permissible exposure time decreases as vibration levels increase, and it reaches a limit of 1.16 hours. To ensure drivers adhere to these permissible exposure times across various driving conditions, measures must be implemented to reduce tractor vibration and minimize its transmission to the driver. By reducing overall tractor vibration and minimizing its impact on the driver, it becomes possible to increase the permissible exposure time for drivers.

Having timely statistics and information from existing uses is a requirement for proper management of natural and urban areas. Considering the extensive changes in land use and the need for managers and planners to be aware of the changes that have occurred in order to make policies and find solutions to solve the existing problems, it seems necessary to reveal the changes in order to determine their time trends. Land use is one of the vital aspects in managing natural resources and evaluating environmental changes. The main goal of this research was to use remote sensing techniques along with GIS and Landsat TM and ETM+ satellite data in the period from 1975 to 2021 to detect changes in land use in Kerman region.

Classification of land use classes, analytical methods and changes were implemented using ENVI 5.3 and ArcGIS 10.3 software. The first step in this study included transferring the coordinates of sample points on satellite images to different land use classes. These points along with the objective data collected from field visits and unsupervised classification maps that show the spectral characteristics of the ground surface using different applications were used as training points for analysis.

The findings of this research after creating maps using Land and detailed analysis shows important changes in the way land is used during the studied period. In particular, urban and residential areas have increased from 1184 hectares to 2160 hectares from 1975 to 2020, which indicates a significant and sustainable growth. This rapid growth of urbanization has happened especially from 1995 to 2015 and has increased by 60% from 975.6 hectares to 2478 hectares. Along with the increase of residential areas, the studied area has also seen a significant increase in dry and unused lands. In the 2021 land use map, about 18% of the areas are classified as unused land. Considering the environmental conditions of the region, such changes may cause serious risks to the people of the region. It is necessary to emphasize that the environmental effects of these changes in land use should be considered. Climatic conditions and higher vulnerability compared to other areas require comprehensive and planned changes in land use. These changes have not only changed the landscape of the region, but may also endanger the ecological balance and sustainability of the region.

Land use maps are essential tools for national and regional development planning. They provide information that shows the current state of land use, allows comparison of capabilities and potential, and designs measures to meet current and future needs. Through the analysis of land use changes in Kerman during the last 45 years, this study shows the impact of urbanization and population growth on the landscape of the region. Its results emphasize that responsible and sustainable changes in land management are necessary to reduce harmful environmental impacts and promote long-term growth. In addition, it emphasizes the great importance of remote sensing technologies and GIS in monitoring and managing changes in land use and provides valuable data for informed decisions by authorities and related organizations.

Human fear of large carnivores can affect human willingness to share the landscape with these species. Also, fear has the potential to influence decision-making processes and the implementation of management interventions. People who fear of large carnivores show more opposition to protect these carnivores and are more likely to support killing them. This study was conducted to investigate the factors affecting the fear of local communities toward brown bears in Kohgiluyeh and Boyer-Ahmad province. In order to find out the attitude of the local communities towards the bear, a specialized questionnaire was designed and the sample size was estimated at 332, using Cochran's formula. Social network analysis was used to assess the vulnerability of local communities towards brown bears. Based on the results, inadequate knowledge of local communities about bears leads to fear and behavioral changes, when facing this species. Efforts to reduce the human fear of bears should be focused on communication with local people. In order to reduce the conflict between human and bears, it is recommended to increase knowledge and awareness of local communities about the brown bear behavior along with other management measures.

The objective of this research is to measure nitrogen dioxide in Beyhaqi Terminal of Tehran and model the release of this pollutant.

In 3 selected stations, sampling was done once a month during the year and three days a month and 3 times a day. For sampling, NIOSH method No. 6004 and Saltzman method were used with the help of Impinger and Saltzman absorbent solution with a flow rate of 0.2 L/min and then the concentration of this pollutant was determined using a spectrophotometer. Austal view, version 7 software was used for modeling.

In both scenarios regarding the one-hour distribution, the pollutant concentration is high at the beginning, and then due to atmospheric conditions and pollutant chemistry, the pollutant concentration decreases, especially in the western direction, but in 3 directions, south, north, and west, from a maximum distance of 300 meters. , the pollutant concentration is greatly reduced. Of course, it decreases much faster from the western side, and the pollution zone continues more towards the east. According to the American National Ambient Air Quality Standard (NAAQS), the allowable amount of this pollutant in a 1-hour average is 100 ppb, no area is in this zone. Also, according to the standard of the World Health Organization, the hourly limit of this pollutant is 200 ppb, and on this basis, there is no limit beyond the standard.

By using management and engineering solutions such as reducing the stopping time of cars, not turning on in place and using exhaust absorbent filters, it is possible to reduce pollutant emissions.

Rotavirus (RV) is the most common cause of acute gastroenteritis in early childhood worldwide. Gastroenteritis is a preventable disease by the vaccine, and vigorous efforts were made to produce attenuated oral rotavirus vaccines. In recent years, despite the existence of three types of live attenuated rotavirus vaccines, several countries, such as China and Vietnam, have intended to produce indigenous vaccines based on rotavirus serotypes circulating among their population. In this study, the immunogenicity of homemade human-bovine reassortant RV candidate vaccine was tested in an animal model. Rabbits were randomly distributed into eight experimental groups with three animals per group. Afterward, three rabbits in each test group designated as P1, P2, and P3 were experimentally inoculated with the 106, 107, and 108 tissue culture infectious dose 50 (TCID50) of the reassortant virus, respectively. The N1 group received the reassortant rotavirus vaccine containing 107 TCID50+zinc. The N2, N3, and N4 groups received rotavirus vaccine strain, RV4 human rotavirus, and bovine rotavirus strain, respectively, and the control group received phosphate-buffered saline. It is noteworthy that three rabbits have been included in each group. The IgA total antibody titer was measured and evaluated by non-parametric Mann-Whitney and Kruskal-Wallis tests. The antibody titer produced in the studied groups did not significantly differ. The candidate vaccine showed immunogenicity, protectivity, stability, and safety. The findings of this study indicated a critical role of IgA production, which can induce immunity against a gastroenteritis viral pathogen. Regardless of purification, candidate reassortant vaccine and cell adapted animal strains could be used as a vaccine candidate for production.

From 1990 to 2020, carbon dioxide emissions have dramatically increased (50%). It has already caused global warming and affected the environment and human health care. Moreover, carbon dioxide has dramatically increased up to 2 times in atmosphere since BCE, and the temperature of earth surface also raised 1°C from the past fifty years. Although novel technologies integrated carbon capture utilization and storage (CCUS) has been already proposed, there are still significant challenges such as cost, economic barriers, and uncertainties on environmental impacts. One promising way to mediate these issues is to utilization of carbonic anhydrase (CA) as enzyme in a eco-friendly manner without any secondary pollutants. In order to utilize CAs in carbon sequestration, high stable CAs on the extreme and harsh environment is essential. This review aims to present advanced developments in CA, efficient engineering strategies to improve the productivity and stability, immobilization techniques towards an industrial operating system. Recent challenges in industrial CAs application as well as its usage perspective in environmental protection have been also discussed.

Family physicians in Iran suffer from lack of relevant knowledge, competencies, and skills. Improving the training program requires examining the currently provided education in the field of Family Physician. This study aimed to evaluate the current status of Family Physician’s Education and training in Iranian medical schools.

This cross-sectional study was conducted using mixed methods combining the elements of quantitative and qualitative research. Data was collected using both close-ended and open-ended author-made questionnaires. Participants in the study were all vice chancellors or heads of social and family departments of public and private Medical Sciences Universities and International Campuses in the country.

While studying general medicine, the conditions for students’ participation in the field of family medicine in most Medical Universities is not available, so that a maximum of 37% of medical universities in the internship course and at least 12% of universities in the clinical preparation course, have provided the opportunity for students to attend in this area. The lowest number of days dedicated to this program was during the basic sciences course, while the internship course dedicated the highest number of days. Also, qualitative results showed that challenges of the Family Physician’s training program are related to clinical education groups, comprehensive health centers, infrastructure, students, and Family Physician’s education curriculum. It is necessary to reform rules and regulations, structures, education, and motivation to overcome current challenges.

The results indicate that the education and training of family physicians in Iran face many challenges, and any planning to expand the current program without careful consideration and overcoming the challenges related to clinical education groups, comprehensive health centers, infrastructure, students, and curriculum, may lead to failure.

Due to its special position in providing drinking water for the people of Hamadan province of Iran and being on the migration path of migratory birds, Abshineh Dam Wetland is important from an environmental point of view. Considering the provision of numerous and valuable goods and services by this wetland, this study aimed at determining the protection value of Abshineh Wetland and measuring the Hamadan residents' willingness to pay for its protection. For this purpose, conditional valuation method was used in a hypothetical market based on general preference. Also, to estimate the model, the logit model and the maximum likelihood estimation method were used, and the two-dimensional double selection method was used to extract the suggested amounts. Sampling was done using cluster random sampling method and study data was collected through interviews with 209 heads of households in Hamadan city in 2018. The study results showed that the variables of education level, household income, the level of familiarity with the wetland and knowledge about the habitat services of the wetland had positive effects, and the proposed amount variable had a negative effect on the willingness of people to pay for the preservation of the Absheena wetland. The average amount of willingness to pay for the preservation of the wetland was about 27870 IRI Rials and the annual protection value of the wetland was estimated to be more than 38.3 billion IRI Rials.

Acute lymphoblastic leukemia is a malignant hematologic disorder of lymphoid lineage. As a result of chemotherapy side effects, treatment with medicinal plants has recently been considered by researchers. Previous studies on Moringa olifera have shown its anti-cancer properties on some cancer cell lines. The aim of this study was to investigate the cytotoxic effects of Moringa oleifera leaves on Jurket and Raji cell lines of acute lymphoblastic leukemia.

In this experimental study, after preparing aqueous and ethanolic leaf extract of Moringa olifera, Jurket and Raji cells were treated with different concentrations of extracts for 48 hours. Cell groups’viability was assessed by trypan blue staining and MTT assay. Peripheral blood mononuclear cells (PBMC) were used as a control group. Statistical analysis of data was performed using Gragh Pad Prism 6 and one-way ANOVA test.

Treatment of Jurkat and Raji cells with all concentrations of aqueous and ethanolic extracts led to inhibition of cell growth. The highest percentage of growth inhibition was obtained at a concentration of 150 μg/mL of aqueous extract, 48.5% and 47.4% for Jurkat and Raji cell lines, respectively. Also, the highest lethal percentage was obtained at a concentration of 50 μg/mL of ethanolic extract, 73.4% and 78.5% for Jurkat and Raji cell lines, respectively. The IC50 dose was obtained in all study groups at a concentration of 150 μg/mL.

The leaves of Moringa olifera have the capacity to inhibit the growth and viability of Jurkat and Raji cell lines of acute lymphoblastic leukemia.

Scorpions are one of the most venomous animals which cause serious public health problems. The sting of scorpions can sometimes be fatal depending on the scorpion species involved. So far, sixty-six (66) scorpion species have been identified in Iran. Annually, about 40-50000 cases of scorpionism are reported in Iran. Odontobuthus doriae and O. bidentatus are among the most medically important scorpion species in Iran, and they are very similar to each other in coloration, carination, and trichobotrial patterns. This morphometric study aimed to compare some of the important morphological characteristics in order to identify the key differences between these two species. A total of 45 morphological characters were measured using calipers and stereomicroscope, and 55 morphological characters and ratios (relative of length to width ratio of morphological characters of scorpions) were analyzed. The independent sample t-test in SPSS software (version 24) was used for the statistical analyses in this study. The mean total length, carapace width, length of fixed and moveable fingers, and chelicerae length of O. doriae were greater than those of O. bidentatus in our study area. The morphological measurements displayed a clear distinction between O. doriae and O. bidentatus in our study area; therefore, they can be used as morphological identification keys for distinguishing between these two species.

Electron beam melting (EBM) is among the modern additive manufacturing processes whereby metal powders are selectively melted to produce very complicated components with superior mechanical properties. In this study, microstructure, hardness, and surface roughness of EBM fabricated Ti6Al4V samples were characterized. The results showed that the microstructure consisted of epitaxially-grown primary columnar β phase transformed to basketweave and Widmanstatten-type α phase during the subsequent rapid cooling. Martensitic needle-type α phase was also observed on the surfaces of the specimens. It was shown that higher parts of the sample had finer microstructures than the lower parts reaching to less than 340 nm in average thickness of the α layers due to distancing from the hot build platform rendering less opportunity for diffusional β → α+β transformation. The porosity content of the samples was lower than that of some other additive manufacturing processes. Vickers micro-hardness of the samples was measured to be around 337 HV which was higher than those reported for other additive manufacturing processes of the alloy.

Semiclathrate hydrate formers such as tetra-n-butylammonium bromide (TBAB), chloride (TBAC) and fluoride (TBAF) are promising compounds that mild the thermodynamic conditions of gas hydrates, considerably. The Clausius-Clapeyron equation is employed in this manuscript to calculate the dissociation enthalpies of methane/carbon dioxide/nitrogen + TBAF semiclathrate hydrates. A 460 cm3 stirred batch reactor was used to measure the phase equilibria of gas + TBAF semiclathrate hydrates at various concentrations of tetra-n-butylammonium fluoride. The dissociation P-T data were obtained using an isochoric pressure-search method in the temperature range of 275.15 to 304.7 K and the pressure range of 0.53 to 10.24 MPa at 0.0 - 0.4482 mass fraction of TBAF. Investigating the obtained dissociation data showed that the addition of TBAF to the solution increases the amount of dissociation enthalpy of semiclathrate hydrates per mole of the hydrated gas. Increasing the mass fraction of tetra-n-butylammonium fluoride, showed a straight relation with the amount of dissociation enthalpy per mole of hydrated gas.

Social media is an integral part of modern society that has become a huge industry for companies to reach loyal customers. The purpose of this study is to investigate the effect of social networks on ethical brand-customer relationships and to provide a model in this regard.

The research method used is a combined research method. In the qualitative part, the Delphi method was used. The statistical population was elites and university professors and experts in the field of marketing and consumer behavior, from which 10 people were selected as a sample by purposive sampling. In the quantitative part it was a descriptive-correlation method. The statistical population of the study was social network users, marketing professionals and business managers active in the online environment in Tehran, of which 384 people were selected by random sampling. The analysis tool was a researcher-made questionnaire. Data were analyzed using structural equation technique and Smart PLS software.

The results of this study show that the empirical and functional benefits of social networks have a significant effect on brand-customer ethical relationships. Also, social networks mediate the online brand experience on the ethical brand-customer relationship has a positive and significant effect.

The dimensions of social networks (empirical interests, functional interests) play an important role in determining the ethical brand-customer relationship and also the ethical brand-customer relationship on its own dimensions (love, commitment, dependence, responsibility). And trust) has an effective and important impact. Customers and brands behave differently under different circumstances and their motivations are different. Therefore, various factors may intervene from the moment a person receives information online through social networks to the end.

In this research, a novel nonlinear control strategy along with its simulation for a quadrotor helicopter is proposed. In the present work, a six-DOF dynamic equations of the quadrotor system subjected to unknown external disturbances based on the Newton-Euler equations is developed completely and without any simplification. Considering the under-actuated and strongly coupled characteristics of quadrotor helicopter, a nonlinear control method is designed using integral backstepping combined with the sliding mode control (integral BS-SMC) to stabilize the qudrotor attitude and to tracking the desired trajectory. The designed controllers based on the hierarchical control scheme can be used to control the rotational and translational movements and their stability are validated by the Lyapunov stability theorem. Using the proposed controller, the chattering phenomenon and discontinuousness of the control inputs faced by traditional sliding mode control (SMC) can be avoided. The feasibility and performance of the presented control approach is verified by the simulations under different scenarios. The results show that the proposed nonlinear control method not only has a better tracking performance than PID controller, but also has a higher robustness when unknown disturbances occur.