MIXED METAL CARBIDES: UNDERSTANDING THE SYNTHESIS, SURFACE PROPERTIES AND CATALYTIC ACTIVITIES

Metal carbides are formed when carbon is inserted into the lattice of the metal, and metal-carbon bonds are formed. In fact, formation of the carbon-metal bonds causes a change in the electronic structure of the metal in a way that metal carbides can catalyze the reactions that usually are catalyzed by the noble metals. The effect of variation of the amount of nonmetal (carbon or oxygen) on the catalytic activity of metal carbides was investigated. The metal carbides are pyrophoric materials, and they need to be passivated before coming in contact with the ambient. The results show that water or CO₂ cannot passivate Mo₂C at low temperatures, and at high temperatures they damage the surface of metal carbides by removal of carbidic carbon. However, oxygen can passivate metal carbides at low temperatures. Passivation in 0.1%O₂/Ar instead of 1%O₂/Ar will cause generation of more active sites during reduction. The results revealed that increasing the amount of carbidic carbon or decrease of the amount of oxygen on the (sub) surface of metal carbides results in an increasing the hydrogenation activity. Also, there is a carbon dynamics (adding or removing carbon) on the surface of metal carbide which can alter the catalytic activity of metal carbides. Metal oxycarbides have bifunctional activity. The conversion of toluene was used to test the bifunctionality of metal (oxy) carbides. Mo₂C has strong metallic behavior and at 20 bar H₂ pressure and 400 °C, hydrogenation and hydrogenolysis products are predominant. In order to modify the metallic behavior of Mo₂C in favor of acid-catalyzed behavior, oxygen was introduced on the surface of Mo₂C to form molybdenum oxycarbide. However, oxygen can be removed at reaction conditions required for ring contraction of six-membered rings to five-membered rings. As a remedy, Mo₂C was mixed with another metal with a higher oxophilicity such as tungsten or niobium. The results indicate that molybdenum-tungsten carbides still have strong metallic behavior with predominant hydrogenation and hydrogenolysis products. However, molybdenum-niobium oxycarbides with cubic NbC structure have lower selectivity to hydrogenolysis products and higher selectivity to ring contraction products compared to Mo-Nb (oxy) carbides with hexagonal Mo₂C structure. The results show that at 400 °C and 20 bar H₂ pressure mixed metal carbides have better stability compared to their corresponding monometallic carbides

The Mediating Role of Psychological Capital in the Effect of Authentic Leadership on Job Satisfaction and Life Satisfaction

The main purpose of this research was to study mediating role of psychological capital in the effect of authentic leadership on job satisfaction and life satisfaction. The study was correlational and statistical population included all employees of organization, out of which 112 employees were selected through convenience sampling method, in autumn 1396. The research instruments consisted of authentic leadership, Job Satisfaction, Life Satisfaction and Psychological Capital. The data were analyzed with use of structural equation modeling (SEM). Results revealed that, there were significant positive effect of authentic leadership on psychological capital, job satisfaction and life satisfaction. Moreover, there were significant positive effects of psychological capital on job satisfaction and life satisfaction. Furthermore, result of structural equation modeling showed that there was significant positive indirect effect of authentic leadership on job satisfaction and life satisfaction through psychological capital. According to the findings of this study, it can be concluded that authentic leadership directly affects psychological capital and through the effect on the psychological capital, increases job and life satisfaction

Construction and Validation of Citizenship Behavior Questionnaire for Students

IntroductionFrom a social psychology perspective, a citizen, who possesses awareness of their own rights and the rights of society, understands themselves as a member of society, and comprehends the broader societal objectives, has a responsibility to fulfill their obligations towards that society. In the 21st century, citizenship encompasses not only knowledge of one's rights but also the willingness to act independently, ensuring that decisions and behavior consistently reflect moral considerations, social justice, and human dignity. Citizenship encompasses various dimensions, including political, civil, social, environmental, and sustainability. Additionally, the expansion of virtual spaces and media has given rise to new dimensions known as media and digital citizenship within the realm of modern citizenship. An important aspect to consider after discussing the comprehensive dimensions of modern citizenship is that, despite the increasing focus of scientific societies on citizenship education in recent years, it remains challenging to assess the impact of citizenship education without a suitable and comprehensive measurement tool, particularly for Iranian society. A review of available tools from outside of Iran reveals that each tool only addresses a specific aspect of citizenship behaviors. Most of these tools prioritize dimensions, such as attitude, thinking, and knowledge, often neglecting the behavioral dimension. Therefore, the purpose of this study was to construct and validate a citizenship behavior questionnaire that could encompass inclusive and comprehensive dimensions for students. By implementing this validated tool before and after educational interventions, it could be utilized to evaluate citizenship across various domains and assess the effectiveness of educational interventions.  Materials & MethodsTo develop a questionnaire for measuring citizenship behaviors across political, civil, social, environmental, sustainable development, media, and digital dimensions, relevant items were selected from the most suitable existing questionnaires in this field. A comprehensive set of questions was created for each dimension and duplicate items were eliminated. Attitude items were modified to measure behavior and supplementary questions were combined. The resulting questionnaire consisted of 106 items, which were then reviewed by 5 experts in the field to assess content and form validity.The target population for this research comprised students from Isfahan universities during the first half of the academic year 2022-2023. Multi-stage cluster sampling was employed to select the participants. A total of 579 individuals completed the questionnaire, but 22 incomplete responses were excluded from the analysis. Therefore, 557 questionnaires were considered complete and suitable for analysis. A scoring system was established, where a score of 1 represented "never" and a score of 4 represented "always," except for items 30 and 85, which were reverse-scored. Discussion of Results & ConclusionThe majority of participants in this study were female students, who were single, with an average age of 22.99 years. Following the criterion of factor load in the revision process, several items were removed from the questionnaire. Specifically, Question 3 from the political section, Question 8 from the civil section, Question 30 from the social section, and Questions 51 and 65 from the environment and sustainable development section were eliminated. Additionally, Item 94 from the media section and Items 71, 80, and 85 from the digital section were removed. In the subsequent step, Item 86 was also excluded.Exploratory factor analysis was then conducted using the Varimax rotation method. The analysis results obtained through Amos software, version 24, indicated the suitability of the questionnaire (CMIN=1035.408, df=318, P=0.000, IFI=0.910, CFI=0.909, TLI=0.886, RMSEA=0.064, and PCLOSE=0.011). The reliability of the questionnaire and its respective dimensions was assessed using Cronbach's alpha, a measure of internal consistency and reliability. The overall Cronbach's alpha for the political dimension was 0.603 with values ranging from 0.567 to 0.654 for its individual dimensions. The civil dimension had a Cronbach's alpha of 0.760, while the social dimension had an overall alpha of 0.862 with values ranging from 0.436 to 0.807 for its dimensions. The environment and sustainable development dimension had an overall alpha of 0.887 with values ranging from 0.505 to 0.796 for its dimensions. The media dimension had an overall alpha of 0.714 with values ranging from 0.385 to 0.615 for its dimensions. Lastly, the digital dimension had an overall alpha of 0.853 with values ranging from 0.699 to 0.806 for its dimensions. To assess convergent validity, 4 questionnaires were administered simultaneously, yielding favorable correlation results. This research aimed to develop and preliminarily validate a comprehensive citizenship questionnaire for students. Based on the results of this questionnaire, which consisted of 6 sections, the dimensions of political citizenship included 6 questions related to participation and persuasion. The civil citizenship section comprised 7 questions. The social citizenship section encompassed 28 questions across 7 dimensions, including dealing with others, considering others, dealing with differences, expressing opinions, compatibility, responsible communication, and critical participation. The environmental citizenship and sustainable development section consisted of 18 questions across 4 dimensions, covering topics, such as purchase and consumption, maintenance, education, and attention to nutrition. The media citizenship section included 13 questions across 3 dimensions, focusing on awareness of representation and its impact on the audience, critical evaluation, and awareness for participation. Lastly, the digital citizenship section comprised 23 questions across 4 dimensions, including ethics and responsibilities, online participation, digital literacy, and learning.It is hoped that with the utilization of this constructed and introduced questionnaire, it will be possible to assess the state of citizenship behavior and ensure the effectiveness of education in this domain

Relationship between Emotional Exhaustion and Deviant Behaviors: Moderating Role of Big Five Personality Traits

Abstract. Personality traits are very important factors for research and theory and also for understanding various employees' behavior at work settings. The aim of the current inquiry was to investigate the relationships between emotional exhaustion and deviant behaviors with consider moderating effects of big five personality factors among employees of an public sector organization in Tehran, Iran. Using a simple random sampling method, a sample of two hundred and sixty five employees responded the emotional exhaustion, deviant behaviors, and big five personality traits questionnaires. The results revealed that extroversion, agreeableness and neuroticism moderate the relationship between emotional exhaustion and deviant behaviors. That is, in high extroversion and agreeableness, emotional exhaustion not significantly related to deviant behaviors, while in high neuroticism, emotional exhaustion positively and significantly related to deviant behaviors. Result of the current investigation showed that agreeableness and extroversion are two protective personality traits, and neuroticism is a personality risk factor in the relationship between emotional exhaustion and deviant behaviors

Investigating the impact of Lent and Brown social cognitive therapy on the components of academic self-efficacy perception of students at Isfahan University of Medical Sciences

Introduction: One of the indicators influencing the academic success of students is their perception of academic self-efficacy. This study endeavored to investigate the effectiveness of Lent and Brown's social-cognitive therapy on the perception of academic self-efficacy and its sub-components among students at Isfahan University of Medical Sciences. Methods: The population for this semi-experimental study was all conditional students of Isfahan University of Medical Sciences, of which 60 students were selected by easy sampling method and were assigned to two experimental and control groups. The experimental group received Lent and Brown social cognitive counseling and the control group received current counseling from the University Counseling Center. The instrument was the students' academic self-efficacy questionnaire. Inferential tests used in this research included one-way analysis of variance, independent t test and analysis of covariance (ANCOVA) Results: In the experimental group after the intervention, the average score of self-efficacy changed from 92.5±14.3 to 96.9±13.8 and from 94.7±8.9 to 95.5±0.9 in the control group. The change in self-efficacy score in the social intelligence group was 4.4 vs. 0.7 in the control group. The findings revealed that there was a significant difference between the experimental and control groups in the perception of academic self-efficacy as well as the two components of academic skill self-efficacy and academic performance self-efficacy. (p<0.05) Conclusion: According to the results of this study, it is suggested that counseling centers of medical sciences university’s use the effectiveness of Lent and Brown's social cognitive counseling method to counsel students with academic failure

Predicting academic performance through perceptions of the family atmosphere with the mediation of creative thinking

&nbsp;Introduction: Family atmosphere perceptions and creative thinking affect on academic performance. This study aimed to predict academic performance through family atmosphere perceptions with the mediation of creative thinking at the Yazd Farhangian University. Methods: This study was a correlation research using a &quot;causal model&quot;. The population included 1,064 students of Yazd Farhangian University in academic year 2016-2017. &nbsp;405 students were selected on based Morgan table using stratified random sampling model according to gender and semester. Measurement tools included Perceptions of Parents Scale (adult version) and a questionnaire of Torrance creative thinking with 60 items. The previous semester GPA was considered as the academic performance index. Questionnaires' data have been investigated in two parts: descriptive and inferential, using SPSS and AMOS and structural equation modeling approach. Result: Independent variables of family atmosphere perceptions and creative thinking explained 29 percent of the variance in academic performance. As well as the indirect effect of family atmosphere perceptions was statistically significant (p<0.001) on academic performance. Therefore, the variable of creative thinking plays a mediating role between the perceived family atmosphere and academic performance. Conclusion: Since family atmosphere perceptions as well as creative thinking have a significant effect on academic performance, the role of parents towards their children and also creative thinking training is very important.&nbsp

Role of Boron in Enhancing the Catalytic Performance of Supported Platinum Catalysts for the Nonoxidative Dehydrogenation of n-Butane

Platinum-based supported catalysts for hydrocarbon conversion are among the most effective for selective dehydrogenation and isomerization processes. However, high process temperatures and the possibility of coke formation require catalyst modifications to mitigate such effects. One of the emerging approaches to prevent platinum catalyst deactivation is the use of boron additives that have been proposed to prevent coking. Despite such a valuable property of boron, the mechanisms for extending the catalyst lifetime and the decrease in coke formation based on this method are still poorly understood. The type and transformations of boron species on silica surface were investigated as a function of boron introduction, platinum addition, catalyst activation, and catalytic reactivity by a combination of X-ray photoelectron spectroscopy, electron microscopy, solid-state nuclear magnetic resonance spectroscopy, and density functional theory calculations to uncover the possible role of boron modification in improving the catalytic performance. Catalytic nonoxidative dehydrogenation of n-butane revealed that incorporation of boron improved the catalytic activity (similar to 3x) and stability of Pt/SiO2. The role of boron in enhancing catalytic performance was attributed to facilitating the migration of alkyl groups from platinum catalytic centers to tetrahedrally coordinated boron sites