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Abstract The need to identify ammonia is necessary because of its harmful effects on the environment and humans. In this study, a colorimetric method was also developed for the detection of ammonia using silver nanoparticles (AgNPs) synthesized with the green approach. Biosynthesis of AgNPs was performed by silver nitrate as a silver precursor and Smyrnium cordifolium extract as a reducing and stabilizing agent. Plant extract was studied by FTIR and LC/Mass techniques. The optimization of the effective parameters was carried out with central composite design according to silver nitrate concentration, plant extract volume, pH, and temperature. Biosynthetic nano-silver was characterized with XRD, EDS/EDX, FE-SEM, FTIR, TGA, and DLS methods. The AgNPs was validated for ammonia colorimetric detection. Biosynthesis of AgNPs were increased in 20 mM AgNO3, 5 ml Smyrnium cordifolium extract, pH 10, and the temperature of 70 °C. Crystal form of AgNPs characterized with XRD at 2Ѳ value of 38.34°, 44.19°, 64.74°, and 77.59° and spherical shape highlighted in the range between 77.8 and 93 nm. Plant extract consisted of polyphenol (phenolic acid, flavonoid, and terpenoid), fatty acid, amino acid, sugar, purine, and organic acid. AgNPs were used for colorimetric detection of ammonia by shifting the λmax from 580 to 490 nm. A method for ammonia detection was set up, with linear range of 0.5–200 ppm, detection limit of 0.028 ppm and recovery level of 96.3 ± 6.5%. In conclusion, a new biosynthetic method by specified local plant was developed to propose a simple and sensitive colorimetric method for soluble ammonia detection.

Removing hydrogen sulfide (H2S) from the air stream in the workplace is important because this toxic gas can cause health problems for workers and destructive effects on equipment. Metal-organic frameworks (MOFs) are one of the most suitable materials for H2S removal and separation. This review study attempted to comprehensively collect the studies and research regarding the removal of H2S from the air stream using MOFs as an effective adsorbent. The databases of Google Scholar, Pub-Med, Scopus, and Web of Science were used in this study. All sections of the articles were reviewed to extract the required data. Keywords such as hydrogen sulfide, metal-organic frameworks, air purification, removal, and adsorption were used to extract the relevant articles. The results showed that UIO-66 and TOUO were the most commonly used MOFs for H2S absorption. The average H2S absorption among all MOFs was 14.92 mg/g. Advances in MOF design, stability, regeneration efficiency, and process integration further enhance their performance, making them more attractive for industrial-scale applications in gas purification and other separation processes. This review article could provide useful information and insight into the remarkable progress in the field of H2S adsorption by MOFs.

Abstract MicroRNAs (miRNAs) are a class of non-coding RNAs (ncRNAs) with a short length of 19–22 nucleotides. miRNAs are posttranscriptional regulators of gene expression involved in various biological processes like cell growth, apoptosis, and angiogenesis. miR-184 is a well-studied miRNA, for which most studies report its downregulation in cancer cells and tissues and experiments support its role as a tumor suppressor inhibiting malignant biological behaviors of cancer cells in vitro and in vivo. To exert its functions, miR-184 affects some signaling pathways involved in tumorigenesis like Wnt and β-catenin, and AKT/mTORC1 pathway, oncogenic factors (e.g., c-Myc) or apoptotic proteins, such as Bcl-2. Interestingly, clinical investigations have shown miR-184 with good performance as a prognostic/diagnostic biomarker for various cancers. Additionally, exogenous miR-184 in cell and xenograft animal studies suggest it as a therapeutic anticancer target. In this review, we outline the studies that evaluated the roles of miR-184 in tumorigenesis as well as its clinical significance.

Background: Today, the usage of artificial intelligence systems and computational intelligence is increasing. This study aimed to determine the fuzzy system algorithms to model and predict the amount of air pollution based on the measured data in subway stations. Methods: In this study, first, the effective variables on the concentration of particulate matter were determined in metro stations. Then, PM2.5, PM10, and total size particle (TSP) concentrations were measured. Finally, the particles’ concentration was modeled using fuzzy systems, including the fuzzy inference system (FIS) and adaptive neuro-fuzzy inference system (ANFIS). Results: It was revealed that FIS with modes gradient segmentation (FIS-GS) could predict 76% and ANFIS-FCM with modes of clustering and post-diffusion training algorithm (CPDTA) could predict 85% of PM2.5, PM10, and TSP particle concentrations. Conclusion: According to the results, among the models studied in this work, ANFIS-FCM-CPDTA, due to its better ability to extract knowledge and ambiguous rules of the fuzzy system, was considered a suitable model.

Abstract The increase in oil production from hydrocarbon reservoirs has always been of interest due to the increase in global oil consumption. One of the effective and useful methods for enhancing oil recovery from hydrocarbon reservoirs is gas injection. Injectable gas can be injected into two modes, miscible and immiscible. However, to inject more efficiently, different factors, including Minimum Miscibility Pressure (MMP) in the gas near-miscible injection mode, should be investigated and determined. In order to investigate the minimum miscible pressure, different laboratory and simulation methods have been prepared and developed. This method uses the theory of multiple mixing cells to simulate, calculate and compare the minimum miscible pressure in gas injection enriched with Naptha, LPG, and NGL. Also vaporizing and condensing process is also considered in the simulation. The constructed model is presented with a new algorithm. This modeling has been validated and compared with laboratory results. The results showed that dry gas enriched by Naphta due to having more intermediate compounds at lower pressure (16 MPa) is miscible. In addition, dry gas, due to very light compounds, needs higher pressures (20 MPa) than all enriched gases for miscibility. Therefore, Naptha can be a good option for injecting rich gas into oil reservoirs to enrich gas.

Introduction: Risk assessment is a systematic and essential procedure to determine the effects, events, and consequences of human activities on perilous systems. This study aimed to identify the hazards and determine the total risk of various units of Ilam Gas Refinery. Materials & Methods: This descriptive-inferential study assessed the risks on 18 various units of Ilam Gas Refinery through a combination of Bow-tie and FMEA methods. Initially, the top event, threats, consequences, as well as preventive and recovery measures were identified using the Bow-tie method. Afterward, Risk Priority Number (multiplying severity, occurrence, and detection) was obtained by FMEA. Finally, the risk level was divided into three groups of low, moderate, and high crisis. Findings: Based on Bow-Tie, the release activity of H2S gas was introduced as the top event. Furthermore, tank leakage and burst, corrosion and wear of pipes and fittings, human error, poor operating conditions, and natural factors in the threat role, as well as damages to human and environmental resources and financial losses were identified as consequences. Based on FMEA, the hazard of tank leakage and burst with two effects of human and environmental damages was in the level of high (major) crisis and was recognized as the most important hazard. Discussions & Conclusions: Gas refineries are faced with many hazards due to the nature of the work process. The integrated approach of Bow-tie and FMEA is a suitable method for risk assessment in such industries.

Abstract Introduction: Fatigue is defined as extreme weakness and exhaustion by work and physical or mental effort. Sleep disturbances are among the most important causes of fatigue among people in various occupational societies. The aim of this study was to determine the relationship of occupational fatigue with sleep quality and factors affecting it among nurses working in governmental hospitals. Methods: This cross-sectional study was conducted on 240 nurses working in public hospitals selected by convenience sampling method during a two-month period. In order to collect data, the Fatigue Exhaustion / Fatigue Recovery Questionnaire (OFER-15) and the Pittsburgh Sleep Quality Questionnaire (PSQI-18) were administered. The data were analyzed using SPSS software version 16. Furthermore, Chi-Square, Spearman’s correlation, Independent Sample T-test, and one–way analysis of variance were run. Results: In this study, 55% and 70% of the participants were at inappropriate sleep quality status and the moderate level of occupational excessive fatigue, respectively. Spearman’s correlation test showed a direct and significant correlation between occupational excessive fatigue and sleep quality (p

Background:Organophosphorus (OP) compounds are considered among the most common insecticides. The major mechanism of organophosphorus toxicants includes inhibiting cholinesterase enzyme. organophosphorus toxicants cause impaired thyroid hormones through affecting different parts of the hypothalamus-pituitary-thyroid axis. The aim of this study is to determine the effects of chronic exposure to organophosphorus pesticides on thyroid function. Methods: The present descriptive-analytical study was conducted cross-sectionally on male workers employed in a factory producing OP as the exposure group as well as the personnel of the administrative department of the same factory as the control group chosen through census method. According to Helsinki declaration, 5 ml of venous blood was collected, and the activity of TT3, TT4, FT3, FT4, and TSH hormones was measured through CLIA method, while the activity of serum cholinesterase enzyme (CHE) was measured through colorimetry. Results: T-test indicated that there was no significant difference in the mean of activity of hormones and enzyme studied between exposure and control groups (p>0.05). Nevertheless, the activity of TT3, TT4, FT3, FT4 hormones, and CHE enzyme was lower in the exposure group, while that of TSH was higher than in the control group. Pearson correlation test indicated that there was no significant correlation between the activity of all studied hormones and CHE enzyme (p>0.05). Conclusions: In the present study, the workers employed in the factory producing OP did not suffer thyroid disorders. Further, OP did not have a considerable effect on the activity of CHE enzyme.

Background and Objective: Inappropriate atmospheric conditions are harmful factors that cause particular problems in certain seasons (summer or winter). The occupation of confectionery in the regions like Ilam causes severe problems due to the heat generated by the nature of the work (synthetic heat-generating processes) and the heat resulting from the climatic conditions in the region. Exposure to excessive heat, in addition to disrupting the physiology and health of the individuals that may cause many diseases and complications, also affects their efficiency and safety. One of the indices of heat stress is the WBGT index, confirmed by various national and international organizations and institutions as the standard method for measuring heat stress. WBGT index engages important environmental factors directly or indirectly in its computational structure. The Discomfort Index (DI) has been recommended for more than four decades along with the WBGT index for the evaluation of warm environments. Today, the oral temperature is used to determine the heat stress and strain. In addition, oral temperature is one of the important parameters for the validation of indices. Therefore, in order to prevent the occurrence of heat stress complications in occupational environments, a study was conducted to determine the amount of heat stress in the employees of confectionery workshops in Ilam city, so as to identify the factors affecting the heat stress of workers and to provide recommendations for the reduction of these risk factors and to create a healthy working environment. Methods: This descriptive-analytical study was carried out on 104 workers in 35 confectionary workshops in summer of 2017. The sample size was selected based on census method. Prior to the study, the workers were monitored through medical records and interviews, and, two of them did not qualify for inclusion in the study. Measurement of the study variables was performed at the hottest work hours (10 to 14), once for each worker, in the worst workstation (nearest to the heat source). In the present study, four groups of occupations, i.e. workers of oven, mixer, flattener, cleaning and packaging, three types of ovens, i.e. layered, winch and furnace, and three productions of wet and dry pastry, cake and French bread, Baghlava and Ka’ak. Assessment of heat stress was performed by the WBGT (based on ISO7243 standard) and the DI indices. Metabolism and activity of workers were calculated according to the ACGIH standard. Also, the working pattern was 75% of the work-25% of the rest, and according to ISO 9920, the clothing insulation coefficient in WBGT calculations was 0.6 clo. Along with the environmental parameters such as dry bulb temperature, natural wet bulb temperature, globe bulb temperature, relative humidity and dew point temperature, the oral temperature of the workers was measured by a digital medical thermometer. Finally, data analysis was performed using SPSS v.22 and statistical tests of Kolmogorov-Smirnov, Mann-Whitney, Kruskal-Wallis, one-way ANOVA and Pearson correlation were performed. Results: Findings of this study showed that the mean of WBGT index in the workers of oven, mixer, flattener, cleaning and packaging was 33.66±3.96, 29.58±3.05, 31.73±3.61 and 29.87±2.4. Also, this index was 30.94±3.86, 34.14±3.89, and 32.2±2.91 for the winch (wet and dry pastry), layered (cake and French bread), and furnace (Baghlava and Ka’ak) ovens (products). These results show that the amount of heat stress in working with the oven and the cake and French bread product (layered oven) was more than others. Kruskal Wallis tests and one way ANOVA showed a significant difference between the mean of WBGT and DI indices with job variables, type of oven and products (p

Introduction: Job stress is an annoying emotional response caused by a mismatch between the job requirements and the individual's abilities. The aim of this study was to determine the status of occupational stress and its effective factors among the employees of Ilam University of Medical Sciences. Methods: This descriptive-analytic study was conducted on 153 employees of Ilam University of Medical Sciences using simple random sampling method in 2016. Philip. L. Rice's Job Stress Questionnaire was used to collect data. The data were analyzed using SPSS software version 16 and descriptive statistics. Furthermore, one-way ANOVA (Scheffe post hoc test), Chi Square, Independent Sample T-test, and Spearman’s correlation were run. Results: The total mean score of job stress was 152.25 ± 31.29 in the study population. This indicates that 68.6 percent of the participants were at average level of occupational stress. Spearman’s correlation test showed a reverse and significant correlation between the subscales of interpersonal relationships, physical conditions of the work environment, and age group variables among headquarters and campus staff (p

Introduction: Health and the factors affecting it are the most important and effective components in behavior, work performance and productivity of individuals working in different organizations. Universities of medical sciences play a fundamental and functional role in health promotion, transfer of its concepts to the community, and delivery of healthcare services. This study aimed to evaluate the general health status and its effective factors among the staff of Ilam University of Medical Sciences, Ilam, Iran. Materials and Methods: This descriptive cross-sectional and analytical study was performed on 153 of staff working at two sectors of pardis and setad of Ilam University of Medical Sciences. The participants were selected using the random sampling method. General Health Questionnaire (G.H.Q-28), which contains 28 items measuring general health, was used for data collection. To analyze the data, ANOVA, Chi-square test, Spearman correlation, and independent t-test were run in SPSS, version 16. Findings: The results showed that 50.3% of the studied population had health score of 0-22 (healthy group). Spearman correlation test showed a significant correlation between general health and marital status (P0.05). In addition, we did not observe a significant association between general health and variables such as age, gender, work experience, educational level, and type of employment (P>0.05). Conclusion: In this study, work experience and employment type were introduced as the most effective factors on performance and general health. Additionally, the subscale of disruption in social performance was the most effective subscale on general health.

Insufficient knowledge of chemical hazards can cause unsafe behaviors, diseases, and accidents in the laboratory, hence educational interventions are significant. Due to its unique qualities, distance learning via educational applications has grown dramatically. This study aimed to determine the efficacy of a safety training intervention via social media applications on the safety knowledge of staff and students at Shahid Beheshti University of Medical Sciences. A total of 166 staff and students at the laboratories of schools and research centers affiliated with Shahid Beheshti University of Medical Sciences were randomized to an experimental group and a control group. A training package was prepared including text, GIF, and video messages on the Globally Harmonized System of classification and labeling of Chemicals (GHS), and the experimental group received a one month training via a common messenger platform in Iran (Telegram). Participants' chemical safety knowledge was assessed before and after the intervention. A validated questionnaire including 24 multiple-choice items in text format and 13 multiple-choice items in image format as well as demographic items was employed to collect data. Shapiro-Wilk, independent t test, and analysis of covariance were used to analyze the data. In the textual section of the questionnaire, the most frequently answered item concerned the "reason for choosing a respirator", and the least frequently answered ones were "meaning of warning" and "meaning of hazard". Environmental hazard and oxidation risk received the most frequent correct answers in the visual section. After the intervention, the control and experimental groups' knowledge scores were 64.7 ± 10.1 and 79.2 ± 8.4, respectively. According to the covariance test, the training intervention improved participants' knowledge significantly (p < 0.001). Training interventions through social media can improve GHS knowledge. Moreover, visual messages are easier to understand and transfer than textual ones.

The carbon nanotube (CNT) reinforced functionally graded materials (FGM) are expected to be the new generation materials having wide range of unexplored potential applications in various technological areas such as aerospace and structural and chemical industry. The present work deals with the finite element modeling and free vibration analysis of CNT based functionally graded beam using three-dimensional Timoshenko beam theory. It has been assumed that the material properties of CNT based FG beam vary only along the thickness and these properties are evaluated by rule of mixture. The extended Hamilton principle has been applied to find out the governing equations of CNT based FG beam. Finite element method is used to solve governing equation with the exact shape functions. Initial analysis deals with CNTs assumed to be oriented along the length direction only. But practically it is not possible. So, further work deals with the free vibration analysis of functionally graded nanocomposite beams reinforced by randomly oriented straight single walled carbon nanotubes (SWCNTs). The Eshelby-Mori-Tanaka approach based on an equivalent fiber is used to investigate the material properties of the beam. Results are presented in tabular and graphical forms to show the effects of carbon nanotube orientations, slenderness ratios, and boundary conditions on the dynamic behavior of the beam.

A method for application of piezoelectric materials to aeroelasticity of turbomachinery blades is presented. The governing differential equations of an overhung beam are established. The induced voltage in attached piezoelectric sensors due to the strain of the beam is calculated. In aeroelastic self-excited vibrations, the aerodynamic generalized force of a specified mode can be described as a linear function of the generalized coordinate and its derivatives. This simplifies the closed loop system designed for vibration control of the corresponding structure. On the other hand, there is an industrial interest in measurement of displacement, velocity, acceleration, or a contribution of them for machinery condition monitoring. Considering this criterion in quadratic optimal control systems, a special style of performance index is configured. Utilizing the current relations in an aeroelastic case with proper attachment of piezoelectric elements can provide higher margin of instability and lead to lower vibration magnitude.