امیر ادیب زاده

Healthcare providers have a high workload due to different work shifts, so they are always exposed to increasing sleep disorders, decreasing resilience, and thus decreasing job satisfaction. The purpose of this study was to investigate the relationship between mental workload, job burnout, job satisfaction, resilience, and sleep disorders among nurses in 2021. Research tools included demographic information questionnaire, NASA-TLX questionnaire, Maslach job burnout questionnaire (MBI), Minnesota job satisfaction questionnaire (MSQ), Petersburg sleep quality questionnaire, and resilience questionnaire (CD. RSC). The data were analyzed using SPSS version 25 and AMOS version 24 software. In this study, 171 women (62.4%) and 103 men (37.6%) were examined. Based on the fit indices (χ2/df=1.650, RMSEA=0.049, TLI=0.906, CFI=0.912), a good fit was observed between the model and the data. The results indicate that mental workload has a positive and significant effect on job burnout (P<0.001, β=0.202). Also, the negative effect of mental workload on resilience (P<0.001, β=0.334) and job satisfaction (P<0.001, β=0.356) have been accepted. The results confirm the positive effect of mental workload on sleep disorders (β=0.166, P<0.05). In addition, the results showed that job burnout has a positive effect on sleep disorders (β=0.153, P<0.05). It is suggested that with proper planning, training, and management of the factors investigated in this study, it is possible to play an important role in increasing the health of nurses and consequently improving their services to patients.

Exposure to impact noise (short-term, high intensity) higher than permitted levels results in injury to the auditory system. Armed forces are one of the occupational groups exposed to these types of noises resulting from gunshots. In this study, relevant articles and research on the adverse effects of impact noise, hearing loss, and tinnitus in armed forces and effective control methods are reviewed.

In this review study, the databases of Web of Science, Scopus, PubMed, Science Information Database (SID), Islamic World Science Citation Center (ISC), and Science Direct were searched with the keywords including noise-induced hearing loss, armed forces, impact noise, control and exposure in armed forces and shooting range. Through determining entrance and exit indicators and consultations among writers, from 68 evaluated articles, 42 entered the study, and 26 were removed.

Several studies measured the gunshot noise level and found that exposure to this noise resulted in different auditory complications depending on the frequency and intensity of exposure. Baseline characteristics and lifestyle are parameters involved in developing noise-induced hearing loss. Active and passive noise control methods and the use of hearing protection devices are among the measures adopted to reduce the intensity of exposure and decrease the detrimental effects of noise on the auditory system.

The use of hearing protection with an active noise cancellation has been developing during the past years, however, it is recommended to use both noise control engineering and hearing protection to reduce the highest level of harmful noise possible when firing a weapon. It should be noted that to prevent hearing loss in the military staff, it is necessary to build medical records upon recruitment for hearing monitoring and conduct periodic examinations.

There are different species of arthropods and rodents in different parts of Iran that are important in terms of medicine and health. To make a proper decision for the control of vectors, it is necessary to have accurate and complete information about the current status of insects control methods for plan and provide appropriate solutions based on it. Therefore, this study aimed to survey the use of chemical insecticides to control vectors in selected categories of military units.

This descriptive cross-sectional study was performed in 2021 on health officials and staff of selected categories of military units. After the necessary coordination, permission to complete the questionnaire was issued for 30 units. Descriptive statistical methods were used to analyze the obtained data.

Among the different controlling methods for insects and rodents, the chemical method has been the most used. DDT and chlordane insecticides were most used in the chlorine group. In this study, only 44.10% of the health managers of military units were aware of the principles of control of vectors and the application of insecticides. In total, 36.22% of them had the necessary skills for operational control of vectors, and 47.52% of them had acquaintance with principles of safety and observed safety issues for control of vectors. As well as, there was no comprehensive protocol for the preparation, distribution, and application of insecticides and safety principles.

In general, knowledge, skills, and observance of safety points among environmental health officials of selected military units have not been at the desired or acceptable level. Codification of the comprehensive protocol on the preparation, distribution, and application of insecticides, as well as, holding long and short-term training courses is recommended for military personnel to increase their knowledge and skills

The olive oil industry wastewater contains significant amounts of oil and this can cause serious problems if it is discharged into the wastewater treatment system, so the oil in the wastewater must be removed and seperated prior to any action. Therefore, the oil in the sewage should be removed and separated prior to taking any measure. There are several ways to remove oil. According to the above, in the present study, the efficiency of the electro coagulation process in reducing soluble COD synthetic wastewater containing olive oil was investigated.

In this study, iron and galvanized electrodes were used. Firstly, the optimum values of current density, initial pH, and electrolyte concentration were determined. Thereafter, the effect of time variations on electrode corrosion, voltage, decreased COD concentration, and energy consumption was investigated. The kinetics of Grade 1, Grade 2, and WeberMorris were also investigated for two electrodes.

The maximum removal efficiency of soluble COD was obtained at 99% for iron and galvanized electrodes at a current density of 12.5 mA/cm 2, electrolyte concentration of 400 mg / l, initial pH 7, and reaction time. The electrical energy consumption in these conditions for these two electrodes was measured at 28.5 and 46.25 KWhr/m3, respectively. Finally, kinetics models, including pseudo-first-order, pseudo-second-order, and Weber Morris, were investigated for these two electrodes. The results revealed that the highest correlation coefficient for both electrodes was related to the pseudo-second-order model.

Although galvanized electrode is more efficient in the reduction of soluble COD concentration, as compared to iron electrode, it consumes more electrical energy. Therefore, the type of electrode must be selected according to the purpose.

Safety climate has been recognized as a powerful tool for predicting occupational accidents. However this has been ignored in some working environments. The aim of the present study was to develop a questionnaire for assessing safety climate among nurses. Using relevant literature, a pool of questions was drafted. Content validity of questions was assessed using the content validity index (CVI) and content validity ratio (CVR). Then, the questions were distributed among nurses with at least three months of experiences from several hospitals in Tehran, Iran, during the summer of 2017. The completed questionnaires were divided into two datasets: the first was used for exploratory factor analysis, and the second for confirmatory factor analysis. The reliability of questionnaire was assessed using Cronbach's alpha coefficient. The effects of safety climate dimensions on safety performance were assessed using the structural equation modeling (SEM) approach. A total of 273 nurses (41 males and 232 females) participated in the study. Most of these nurses had work experience of one to five years and ranged from 25 to 30 years of age. The final questionnaire contained 19 questions and the exploratory factor analysis (EFA) revealed four dimensions; management commitment to safety; supportive environment; safety training; and perceived work pressure. The structure was confirmed to be acceptable by the following confirmatory factor analysis (CFA) (Chi-square/df=1.01, RMSEA: 0.018, TLI: 0.993, and IFI: 0.994). Supportive environment and management commitment to safety were rated as the two dimensions with the highest effects on the safety performance of nurses in hospitals. The management commitment to safety, supportive environment, safety training, and perceived work pressure were the main dimensions of safety climate in hospitals. Management commitment to safety and supportive environment were the best predictors of safety performance of nurses in hospitals.

The purpose of this research was to study both fresh and manganese oxide modified bone char as an adsorbents for the removal of excess fluoride from drinking water. This research was an experimental (laboratory) study. Fresh bone char was obtained from raw bone pyrolysis at 450 °C. For bone char modification thermo-chemical reaction and a manganese compound was applied. Adsorbent surface characteristics and specifications were prepared by a conventional method, BET, BJH, XRD, respectively. The effect of fluoride concentration, the amount of adsorbent and pH on the adsorption capacity were investigated. Also the adsorption data were analyzed using the Langmuir, Freundlich and Temkin adsorption isotherm. The results showed that the adsorption of fluoride in bone char types often follows Freundlich isotherm. Increased concentrations will increase the adsorption rate. An increase in the rate of adsorbent led to increasing the adsorption capacity and can reduce the removal efficiency. The optimum mass of adsorbent and pH were 0.5g and 7 respectively. Modification of Bone char with manganese oxide increases the specific surface area and a higher efficiency in the removal of fluoride will be adsorbed. Results show that this adsorbent can be used for the removal of fluoride in water operating (operational conditions) environments and after adsorption processes would not need to stabilize PH.

Bachgrounds and Oil, gas and petrochemical are known as important sources of air pollutants and emission of green house gases. About 99 percent of sulfur dioxide in the air is produced from human resources.Although several samples have been taken from industries and refineries’ output by environmental experts and private companies, but accurate assessment is not available based on pollutant emissions on product levels (emission coefficients) and on the total amount of the annual emission which, can be used as basic modeling of air pollution and planning. This study was cross sectional and the output of the chimney measured with Testo 350 XL system. Performance standard was determined based on ASTM D6522 EPACTMO30- 41. The amounts of sulfur dioxide were measured from Tehran oil refinery’s outlet from the beginning of the march 2007 till the year 2008 for 20 months. Sampling was carried out on averaged range (9 am to 14 pm) The results showed that Northern Distillation unit produced pollutants’ concentration more than 3 times in the southern Distillation unit. An emission of pollutants from Northern unit was, 2.8 times higher than the Southern unit. The northern emission factor was 5.6 times higher than the value obtained from southern unit. The Concentration, emissions and coefficient of sulfur dioxide in North catalyst convert unit were more than 2 times in comparison with the same South unit. These three factors in northern concentration breakers unit were 3, 2.6 and 2.6 times higher than the Southern concentration breakers unit‚ respectively. Emission rate in all northern units is 2 to 3 times more than similar southern units. The production volumes in northern units are higher than the southern units and the southern units designed properly to remove more pollutants. The use of new technologies in production processes and application of the latest scientific resources can play a major role on pollutants’ reduction.

Microorganism activity in the biological reactor converts contaminants to harmless products. Bio-filter is a continuous biological reactor and a new technology for decomposing different contaminants. This study aimed to evaluate of acclimatization Thiobacillus thioparus to removal hydrogen sulfide in a bio-filteration system with used seashell for packing media. For reproduction and microbial activation, it require to prepare special culture medium, vitamin and trace elements solution. After made three solutions we cultivate the bacteria. The bio-filter column were constructed using transparent plexyglass with a height of 40 cm and diameter of 15 cm and bed depth of 27.5 cm, fulled by seashell packing media. The porosity of seashell packing media is 63 percent. Bio-filter has four inlet pipes in above space. This pipes use for injecting air flow, injecting polluted gas, effluent readings for H2S, injecting nutrient and culture medium. Bacterial activity have been surveyed for 15 week and removal efficiency by T. thioparus were evaluated and various concentrations, less than 20 mg/m3 to more than 100 mg/m3. The best performance observed in 29oC. Also optimum pH was 7-7.5 for a stable system. The number of measured samples were 550 and for each concentration at least 6 reading at different time. The results observed that, the removal efficiency was increasing so the adaptation process was increasing. It was possible that increase of concentration inlet polluted gas without affect on the removal efficiency. It means that the bio-filter is stable. The obtained results observed that polluted gas concentration has not significant effects on gas treatment process and removal efficiency were 78-88 percent, when the T. thioparus acclimated in the desirable conditions for removal polluted gas. Also removal efficiency will remain well when the humidity rate was 77-93 percent and temperature was 20.5-30oC in growth and reproduction of T. thioparus. When T. thioparus acclimated and obtained stable conditions in seventh week, biomass production rate would be increasing and upward until fifthly week.

The hydrogen sulfide is a toxic, flammable and colorless gas. Traditionally, the control of H2S emissions includes direct air stripping, precipitation and chemical oxidation. Considering the advantages of biological methods, this study aimed at treating H2S using biofiltration. Three types of media; a pearl medium, a compost medium and an activated carbon medium, were evaluated for sulfur inhibition and capacity for removal of hydrogen sulfide (H2S). In this study, the biofilter columns were constructed using transparent plexyglass pipes with a diameter of 15 cm and a height of 40 cm, with a bed depth of 27.5 cm. Have been measured, produced H2S gas was passed through the three different biofilter media and effluent readings for H2S at the outlet points of three different columns were measured. The three biofilters with different media blends were operated in parallel for ten weeks continuously treating hydrogen sulfide, at various flow rates and concentrations. After being stabilized, the overall removal efficiencies of three different columns were measured at the outlet points and observed that the efficiency of the column packed with activated carbon remained ~100% at different flow rates, concentrations and empty bed retention times (EBRT). The overall removal efficiency of compost and seashell media columns was similar in about 88-90% and 80-90%, respectively. Biological treatment of air emissions is a cost-effective, environmentally friendly and sustainable control technology for industrial and municipal facilities. Having lesser pollution potential in end products as well as lower operational and maintenance costs are the other advantages of these systems.

Introduction. Giardia, a flagellate protozoan, is a sort of intestinal parasite in human and animal bodies. Despite of man-to-man conventional method of transferring, this parasite is one of the main causes of water born diseases, and addition of conventional rates of chlorine to water cannot remove it. Ozone is an excellent disinfectant and can inactivate the most resistant microorganisms. It is used periodically to disinfect drinking water. The aim of this study is to evaluate the rate of ozone used for removal of giardia cysts in water.Material and Methods. This is an experimental study and corona discharge method is used to generate ozone. Giardia cysts were separated by concentration density slope with sucrose, counted 10 times with Thoma lam and then the mean was calculated. This solution, containing 120,000 cysts/lit, was ozonated in 5, 7 and 9 min with the density of 1.3 mg/lit in city water, distillated water and physiology serum. In another test, the effect of elapsed time on ressistance of giardia cyst was evaluated for a 6-day period, in the first, 3rd and the 6th day for various minutes of 1, 3, 5, 7 and 9 with the density of 2 mg/lit in the city water.Results. Durations of 5 and 7 minutes could not remove all of the cysts, but after ozonation for 9 minutes, all of the cysts were removed. When tests were performed in distillated water and physiology serum, all of the cysts were removed completely. In another test, all of the cysts were removed in the durations of 7 and 9 minutes of the first day, while in the third and the sixth day, the efficiency of cyst removal rate decrease in the 7 and 9 minutes and fresh cysts were observed.Conclusion. Distillated water and physiology serum caused disturbance in the test and resulted in incorrect data, so decolorized city water is used in this pilot study. As time elapsed, environmental conditions caused difficulties for cyst life continuing. Cyst's cell wall gets resistant and removal of all of giardia cysts with first day Ct is impossible.