Delphinidin immobilized on silver nanoparticles for the simultaneous determination of ascorbic acid, noradrenalin, uric acid, and tryptophan

AbstractIn the present study, the fabrication of a new modified electrode for electrocatalytic oxidation of noradrenalin, based on the delphinidin immobilized on silver nanoparticles modified glassy carbon electrode. Cyclic voltammetry was used to investigate the redox properties of this modified electrode. The surface charge transfer rate constant (ks) and the charge transfer coefficient (α) for the electron transfer between the glassy carbon electrode and the immobilized delphinidin were calculated. The differential pulse voltammetry exhibited two linear dynamic ranges and a detection limit of 0.40μM for noradrenalin determination. Moreover, the present electrode could separate the oxidation peak potentials of ascorbic acid, noradrenalin, uric acid, and tryptophan in a mixture. The usefulness of this nanosensor was also investigated for the determination of ascorbic acid, noradrenalin, and uric acid in pharmaceutical and biological fluid samples with satisfactory results

Study of Status Anxiety among Librarians of Central Libraries of Public Universities in Tehran

Objective: The purpose of this research is to investigate the status anxiety and its dimensions among librarians of central libraries of public universities in Tehran. Methodology: This research is an applied and survey research. The research sample was the librarians of central libraries of public universities in Tehran of Tehran. A questionnaire was used to collect the data, which includes 65 questions under three individual, organizational, and socio-cultural dimensions. Descriptive and inferential statistics including Friedman test, independent t test, F test, and Pearson correlation test were used to describe and analyze the data. Findings: The findings showed that the level of status anxiety in terms of the individual dimension is higher than the organizational and socio-cultural dimensions. The average of status anxiety is high in the individual dimension and moderate in the organizational and socio-cultural dimensions. In addition, there is no significant difference in the level of status anxiety in terms of gender, age, and professional experience of librarians, and dignity anxiety is experienced by all librarians of central libraries of public universities in Tehran. Conclusion: Since the librarians of university libraries are part of the official system of university education and research and deal with a diverse range of students in different fields, it is desirable to reduce the status anxiety in their profession and to create a sense of value and self-confidence in them. Training librarians to manage their anxiety, providing fair wages and welfare for librarians as best as possible, and introducing the values of the librarianship profession through mass media and social networks, can help to increase self-confidence and reduce the status anxiety of librarians from the individual, organizational, and socio-cultural point of view

An Investigation into the Relationship between Knowledge Management Infrastructures and Organizational Intelligence in Research Centers of the Ministry of Science, Research and Technology

This study investigates the relationship between knowledge management infrastructures and organizational intelligence in two research centers of Ministry of Science, Research and Technology, namely Iranian Research Institute for Information Science and Technology and Institute for Humanities and Cultural Studies. The research is a survey in descriptive manner. Using two validated questionnaires related to knowledge management infrastructures and organizational intelligence, the research was conducted among 175 faculty members and staff of the two research centers. Collected data were then analyzed by SPSS and PLS software. Factor analysis showed a high factor loading related to the two main variables and all of the items indicated goodness of fit of the questions. Variance mean ratio between two variables was higher than 0.5 indicating a high convergent validity. R squares for organizational intelligence showed fitness of structural equating model. Goodness of fit for Iranian Research Institute for Information Science and Technology was 0.642 lower than Institute for Humanities and Cultural Studies with 0.645. Path analysis indicated a significant relationship between two variables by 95% degree of confidence accepting the two research hypothesis. By comparison, knowledge management infrastructures was more correlated with organizational intelligence in Institute for Humanities and Cultural Studies than Iranian Research Institute for Information Science and Technology. Knowledge management infrastructures in Iranian Research Institute for Information Science and Technology predicted organizational intelligence by 0.826 percent while in the Institute for Humanities and Cultural Studies by 0.848 percent

An Investigation into the Relationship between Knowledge Management Infrastructures and Organizational Intelligence in Research Centers of the Ministry of Science, Research and Technology

This study investigates the relationship between knowledge management infrastructures and organizational intelligence in two research centers of Ministry of Science, Research and Technology, namely Iranian Research Institute for Information Science and Technology and Institute for Humanities and Cultural Studies. The research is a survey in descriptive manner. Using two validated questionnaires related to knowledge management infrastructures and organizational intelligence, the research was conducted among 175 faculty members and staff of the two research centers. Collected data were then analyzed by SPSS and PLS software. Factor analysis showed a high factor loading related to the two main variables and all of the items indicated goodness of fit of the questions. Variance mean ratio between two variables was higher than 0.5 indicating a high convergent validity. R squares for organizational intelligence showed fitness of structural equating model. Goodness of fit for Iranian Research Institute for Information Science and Technology was 0.642 lower than Institute for Humanities and Cultural Studies with 0.645. Path analysis indicated a significant relationship between two variables by 95% degree of confidence accepting the two research hypothesis. By comparison, knowledge management infrastructures was more correlated with organizational intelligence in Institute for Humanities and Cultural Studies than Iranian Research Institute for Information Science and Technology. Knowledge management infrastructures in Iranian Research Institute for Information Science and Technology predicted organizational intelligence by 0.826 percent while in the Institute for Humanities and Cultural Studies by 0.848 percent

Adsorption of Nickel and Chromium From Aqueous Solutions Using Copper Oxide Nanoparticles: Adsorption Isotherms, Kinetic Modeling, and Thermodynamic Studies

The research was conducted with an aim to assess the efficiency of copper oxide nanoparticles as an adsorbent to remove Ni and Cr. The effect of pH, adsorbent dosage, contact time, initial concentration of metals (Ni and Cr) on the adsorption rate was evaluated and removal of these elements from aqueous solutions was measured using Atomic Absorption Spectrum System (Conter AA700). Moreover, the kinetic and isotherm besides thermodynamic adsorption models were assessed. The highest Ni and Cr removal rate occurred at an optimal pH of 7, and an initial concentration of 30 mg/L, a time period of 30 minutes, and 1 g/L of copper oxide nanoparticles. In fact, with the increase of adsorbent dosage and contact time, the removal efficiency increased and with initial concentration increase of Ni and Cr ions, the removal efficiency reduced. The correlation coefficient of isotherm models viz. Langmuir, Freundlich, Temkin, Redlich-Peterson, and Koble-Corrigan showed that Ni and Cr adsorption via copper oxide nanoparticles better follows the Langmuir model in relation to other models. The results showed that kinetic adsorption of Ni and Cr via copper oxide nanoparticles follows the second order pseudo model with correlation coefficients above 0.99. In addition, the achieved thermodynamic constants revealed that the adsorption process of metals (i.e., Ni and Cr) via copper oxide nanoparticles was endothermic and spontaneous and the reaction enthalpy values for these metals were 17.727 and 11.862 kJ/mol, respectively. In conclusion, copper oxide nanoparticles can be used as effective and environmentally compatible adsorbents to remove Ni and Cr ions from the aqueous solutions

Assessing Reliability and Validity of an Instrument for Measuring Resilience Safety Culture in Sociotechnical Systems

Background: Safety culture, acting as the oil necessary in an efficient safety management system, has its own weaknesses in the current conceptualization and utilization in practice. As a new approach, resilience safety culture (RSC) has been proposed to reduce these weaknesses and improve safety culture; however, it requires a valid and reliable instrument to be measured. This study aimed at evaluating the reliability and validity of such an instrument in measuring the RSC in sociotechnical systems. Methods: The researchers designed an instrument based on resilience engineering principles and safety culture as the first instrument to measure the RSC. The RSC instrument was distributed among 354 staff members from 12 units of an anonymous petrochemical plant through hand delivery. Content validity, confirmatory, and exploratory factor analysis were used to examine the construct validity, and Cronbach alpha and test-retest were employed to examine the reliability of the instrument. Results: The results of the content validity index and content validity ratio were calculated as 0.97 and 0.83, respectively. The explanatory factor analysis showed 14 factors with 68.29% total variance and 0.88 Kaiser-Meyer-Olkin index. The results were also confirmed with confirmatory factor analysis (relative Chi-square = 2453.49, Root Mean Square Error of Approximation = 0.04). The reliability of the RSC instrument, as measured by internal consistency, was found to be satisfactory (Cronbach α = 0.94). The results of test-retest reliability was r = 0.85, p < 0.001. Conclusion: The results of the study suggest that the measure shows acceptable validity and reliability. Keywords: Instrument, Reliability, Resilience safety culture, Validit

Copper and Nickel Determination in Grape Extract Cultured around Marvast City,Yazd

Background: One of the most critical problems in the field of water and food pollution is the heavy metal pollution. Agricultural products are exposed to this type of contamination through wastewater; industrial activity and population pollutions are also in its area. Since the plant in the affected areas can directly enter heavy metals into the food chain, so, it is important to check their level of contamination. The purpose of this study was to monitor distribution of copper and nickel in the grape cultured in the farms around Marvast in Yazd province. Methods: All chemicals were of analytical grade. In order to determine the level of copper and nickel in grape extracts produced from the most important areas in grape production, 7 samples of grape were taken from these geographic regions. After grinding and homogenizing of samples, the concentration of nickel and copper, heavy metals were measured by atomic absorption spectrometer. The obtained results were analyzed through SPSS software based on statistical methods. Results: The mean value of copper and nickel were 26.4 &plusmn; 3.1 and 12.3 &plusmn; 1.5 &mu;g/kg, respectively. According to the obtained results and their comparison with standards, different amounts of copper and nickel were observed in all samples, however, the highest amount of these metals was observed in one sample. Conclusions: Concentrations of heavy metals in samples from different regions were lower than the maximum allowable concentration of copper and nickel. Although, the amount of these metals in one sample, known as pollution indicator, suggested that this area can be exposed to both

Application of Value Engineering to Improve upon Customer Services Performance in Mazandaran Water and Sewage Company

Over the course of producing and marketing goods and services, it appears that industry faces a new challenge in which information and science form the basis for any organizational movement. In this regard, the competitive preference of the organization concentrates on customer and value creation in the organization. Value engineering recognizes product/service functions and produces those with the maximum value at the lowest cost without the loss of production or service quality and safety. In this paper, using value engineering based on the international job plan of the SAVE (Society of American Value Engineering), various alternatives are proposed to improve upon the performance of Customer Services of Water and Sewage Co. The results indicate possible savings of about 714 Million Rials for the water authority in the city of Sari and 4860 Million Rials across Mazandaran Province