علی صفری واریانی

 Shift work among industrial workers can lead to poor sleep quality, which instead is associated with stress, anxiety, and depression. This study aimed to investigate the relationship between sleep quality and stress, anxiety, and depression in shift workers in one of the food industries.

 The participants in this descriptive-analytical study were 208 production line workers in one of the food industries. Data were collected using a demographic questionnaire, Pittsburgh Sleep Quality Questionnaire (PSQI), and depression, anxiety, and stress (DASS-21). Spearman's statistical test was used to investigate the relationship between sleep quality and depression, anxiety, and stress. The data were analyzed using SPSS-23 software.

 About 42% of workers reported undesirable sleep quality (score more than 5). Almost half of the workers reported a level of normal stress, anxiety, and depression. The results showed that there is a positive and significant correlation between sleep quality and stress (r=0.20, P<0.01) and sleep quality and depression (r=0.172, P≤0.01) so that the quality of sleep, stress, and depression interact with each other and have a mutual effect.

 According to the results of this study, reducing stress and depression can improve the sleep quality of workers, and in turn, good sleep quality can lead to reducing stress and depression in shift workers. Therefore, identifying the influencing factors and corrective strategies to reduce stress, anxiety, and depression can play an important role in improving the sleep quality of shift workers.

Using backpacks has arisen complaints regarding musculoskeletal pains among students. The aim of this study is to investigate the relationship between demographic information and bag weight with Neck Disability Index (NDI), angles and head and neck postures among students.

This descriptive-analytical and cross-sectional study was conducted among 80 students who were selected randomly. Demographic information and NDI questionnaires were used for data collection. The head and neck tilt angles and the amount of change in the forward head posture were determined using the photogrammetry method and Kinovea software.

A negative and significant correlation was observed between head tilt angle with age (r = - 0.27) and neck tilt angle with body mass index (r = - 0.37). Also, a positive and significant correlation was observed between the amount of change in the forward head posture and body weight (r = 0.24). The head tilt angle was significantly different in male and female students at different educational levels. NDI (r = 0.23) and neck tilt angle (r = 0.26) also increased significantly with increasing bag weight.

Reviewing the standard weight of bag and changing the lifestyle can play an important role in improving the head and neck angles and postures.

The purpose of the current study was to predict the percentage of the sway index from the static balance point based on the anthropometric dimensions of construction workers.

This descriptive-analytical study was conducted on 114 construction workers. First, the construction workers were asked to complete the demographic questionnaire and the inclusion criteria were determined. Then, the anthropometric dimensions were measured. Afterward, the static balance of participants was assessed with their open eyes and standing position using a Stabilometer device. The obtained data were analyzed using Pearson correlation and multiple linear regression.

29.8% of construction workers were in weak and very weak classes in terms of static balance. The Pearson and spearman’s correlation coefficient showed a significant relationship between age, weight, and sway index of individuals. In addition, multiple linear regression showed that age, weight, and foot surface of construction workers can predict the percentage of the sway index from the static balance point among construction workers.

The results of the current study indicated that demographic information such as age, anthropometric parameters of weight, and foot surface are effective factors on static balance in a healthy construction workers’ community with a normal body mass index.

Punch press is contributed as one of the major industrial machines to produce metal objects, which typically propagates hazardous noise. Acoustic enclosure is the most common method to mitigate noise transmitted from industrial equipment. This study aimed to assess the role of opening dimension and location in a partial acoustic enclosure on occupational noise exposure of punch press’s operator.

A punch press with the capacity of 60 tons in an automotive manufacturing company was considered as a real noise source. Equivalent noise exposure level was measured with reference to ISO 9612 using Cassella Cell-450 sound meter, before and after noise control intervention. Rubber sheet and mineral wool as insulation and absorption acoustical material with the thickness of 2 and 50 mm, respectively, applied to build acoustic enclosure. Rubber sheet sound transmission loss was measured using BSAW SW 477 acoustic impedance tube to predict acoustic performance of enclosure. In addition, Partial acoustic enclosure with the dimensions of 1.4 by 1.2 by 3 meter was constructed and opening areas which was equal to 2, 3, 5 and 7 percentage of total area of enclosure was created in front of punch press operator. Finally, an opening equals to 2 percentage of total area of enclosure was created on the left sidewall of enclosure to assess the location of opening on noise level.

Punch press operator noise exposure level was measured to be 89 and 67 dBA before and after using full acoustic enclosure respectively.  After using partial acoustic enclosure with open area percentage of 2, 3.5 and 7 on the front side of press, operator noise exposure level was measured 78, 79, 78 dBA, respectively which was a little bit more than predicted noise. As the opening position was relocated from the front wall to the sidewall of the enclosure, operator noise exposure was reduced from 78 to 69 dBA respectively. Although, there was not significant differences between mean sound level of the punch press after relocation of opening. 

Utilizing full acoustic enclosure constructed from insulation material recommended in this study, reduced punch press operator noise exposure remarkably. Although, opening area of partial acoustic enclosure was increased to some general extent to feed punch press, there was a slight change in noise exposure of press operator. On the other hand, press operator noise exposure was plummeted with the relocation of opening. Therefore, front opening dimension could be chosen fairly wide to access and feed operation zone of punch press without exposing operator with more noise level. Furthermore, repositioning the opening from the front wall to the side wall of the enclosure and automatically feeding the press through side opening could substantially reduce the operator noise exposure.

Work-related musculoskeletal disorders (WMSDs) are one of the most important causes of absenteeism, increased costs and human injuries, which are very common in computer users. The purpose of this study was to investigate the effect of 8 weeks of corrective exercise on reducing the prevalence of musculoskeletal disorders (MSDs) in computer users working in a gas company.

This cross-analytical study was conducted on 101 computer users working in a Gas Company in Qazvin city in 2019. Fourteen people participated in 8 weeks correction training intervention program (16 sessions in 1 hour and 2 times a week). Nordic questionnaire and body map were used in order to investigate the prevalence and severity of MSDs. The data were analyzed using Kolmogorov-Smirnov, Cramer V, McNamar, Paired sample t-test and Wilcoxon tests in SPSS version 23 software.

The most common disorders were shoulder (64.3%), waist (42.9%) and neck (35.7%) regions among computer users during the last week before intervention. The prevalence of MSDsby strength and flexion exercises in neck and shoulder regions with 95% and 99% confidence showed a significant decrease before and after intervention. The incidence of discomfort in the waist region decreased by 35.8% after intervention and in other regions decreased by at least 7.1%.

The results of this study showed that implementation of corrective training intervention program by exercise specialists can increase muscle stretch and consequently decrease the prevalence of MSDs7.1%- 64.3%.

Safety training is believed to be one of the pioneering safety measures to improve the safety culture in organizations. The aim of this study was to determine the impact of training and technical interventions on providing a work environment with proper safety culture and understanding the risk of dangerous situations at height among construction workers.

In this interventional study, 394 workers of different job groups in construction companies including impact driver operators, masonry workers, ironworkers and concrete vibrating operators were entered. Data were collected using “demographic”, “safety culture” and “the risk of dangerous situations at height” questionnaires. Questionnaires were completed and collected in three stages: before the intervention, two months after the first intervention and two months after the second intervention (eight months after the first intervention). The data were analyzed using Bonferron's modulation tests (follow-up tests in variance analysis) and binary logistic regression test in SPSS version 23 software.

The findings of the present study revealed the significant impact of safety training on all components of the safety culture and also the empowerment of workers in understanding of risk of dangerous situations at height. The findings of this study, also revealed the significant improvements in safety culture, indicating the role of training along with technical intervensions as crucial factors in improving workers safety in organizations.

Industries can prevent occupational accidents and their consequences by adopting proper safety and hygiene measures and engineering design through a coherent training program and achieve a sustainable industrial and development prosperity. In this regard, the findings of the present study showed that conducting training courses by involving workers and encouraging group discussion and expressing the importance of safety in the workplace as well as technical measures can positively influence workers' safety behaviors and promote safety culture. Exchange of views and sharing experiences, well-designed training programs, and devoting enough time can also be effective in promoting safe behaviors.

Clean air is one of the most important components of health and sustainable development. Every person breathes about 10 kg of air per day and if it contains pollutants, it will have a serious impact on their health. Indoor air quality (IAQ) is one of the major health issues that have been addressed in recent years with changes in lifestyle patterns. Usually, due to the increased time of presence and activity in these environments and reduced air exchange with the outdoor environment, indoor air quality is poorer than outdoor environments. Toluene is a Volatile organic compound with widespread applications. VOCs has a high vapor pressure and high emission rate to environment. Due to its adverse effects on human and environment health, they must be controlled before discharging to the environment. Photo catalytic oxidation process is one of the environment-friendly and effective methods for the remove the organic compounds from the air which likely to be better in combination with other methods such as adsorption. Through the process of PCO, UV radiation adsorption on TiO 2 is associated with forming electron and holes from electron escape. The resulted electrons have got high levels of oxidation power and act as a strong oxidant producing superoxide ion. The resulted holes have good oxidation potential; with superoxide ions, they make good conditions for oxidation of most organic compounds to less hazardous compounds such as carbon dioxide and aqueous vapor.  The most important limitation of Photo catalytic oxidation process is the dependence of the contaminant removal on the surface chemistry and the residence time of the contaminant on the photo catalyst surface. The most important limitation of the adsorption method is the decrease in adsorption removal efficiency and elimination capacity due to the filling of the adsorption sites.According to this, by combining adsorption and photo catalytic oxidation, it is possible to increase the time of contaminant presence at photo catalytic oxidation sites and to enhance the surface chemistry and on the other hand, to restore the adsorption sites. This study is conducted with the aim at examining the effects of combination Activated carbon and Titanium dioxide (TiO2) on the toluene removal efficiency.

In order to prepare samples, 5g of TiO2 and 5g of TiO2 and 1g of activated carbon dissolve in separate 100 ml distilled water under vigorous stirring. The surface modification was done by dip-coating method. The efficiency of the photocatalytic oxidation of toluene is evaluated in two separate reactors exposed to ultraviolet light. Additionally, to investigate the effect of initial concentration of toluene and airflow rate on the photocatalytic removal efficiency in photocatalytic and photocatalytic-adsorption beds, the RSM method was used to design experiments.Also, Scanning Electron Microscopy was used to determine catalysts surface morphology. First, to obtain the adsorption capacity in both reactors, with the UV lamp being off, the considered concentrations were added to the reactors in 2-5 L/m airflows. Then, adsorption capacity of adsorption beds were evaluated according to the time needed for the outlet concentration to reach 10% of the inlet amount, as the fraction point of the adsorbent and saturated capacity.Next, to compare the removal efficiency of toluene in the two reactors, the lamps were immediately turned on; concentrations were gradually decreased and when the outlet concentration was balanced, the data was collected.

Images from an electron microscope of surfaces of the two catalysts showed that the distribution of nanoparticles on glass wool was similar and the particle size in the non-combined catalyst were smaller than 95 nm, and smaller than 87 nm in the adsorbent catalyst. In other words, the size of nanoparticles led to more contact area of the pollutant with the catalyst, increased reaction as well as removal efficiency. SEM photography confirmed that, combining Ti O2 with activated carbon, the pores in the activated carbon were occupied and it made a good place for Ti O2. Controlling the process of photocatalytic elimination in photocatalysts indicated that in TiO2-AC reactor, removal efficiency and elimination capacity of toluene were higher than TiO2 reactor and combining adsorbent with photocatalyst may lead to enhanced photocatalytic oxidation efficiency of organic compoundsThe results illustrate that the removal efficiency and elimination capacity of toluene in photocatalytic and photocatalytic-adsorption beds are Influenced by airflow rate and inlet concentration of toluene. In optimized operational conditions, the removal efficiency in both combined and non- combined reactors in inlet loadings of 84.5 and 1.65 mg/m3.s and retention time of 2 and 8.5 s, was 99.98% and 95.14%, respectively. Also, elimination capacity in optimized operational points in the two absorbent and non-absorbent photocatalysts was 5008.71 and 1204.85 mg/m3.min, respectively.  As the statistical analysis by Minitab indicated, in the concentration range of 10-40 ppm and the airflow of 2-5 L/min (in 2-8.5 s retention time) in the combined reactor, the removal efficiencies were 90% (min.) and 99% (max.); however, in the non-combined reactor, the minimum of removal efficiency was 10% and the maximum was 90%.The results of this study also indicated that the retention time had a significant effect on the removal efficiency and the elimination capacity of toluene, that is, at the constant inlet concentration (25 ppm) increased with increase in retention time of the non-composite reactor. However, in the adsorbent reactor, lower retention time led to higher removal efficiency. According to the results, toluene removal efficiency and elimination capacity levels in the combined reactor in time retentions of 2, 3.3 and 8.5 s increased compared to the non-combined reactor. Also, evaluation of the effects of initial toluene concentration on removal efficiency and elimination capacity showed that they were higher in the combined vs the non-combined reactor. Removal efficiency of both photocatalysts was influenced by the initial concentration of toluene, so that, in TiO2 higher inlet concentration led to lower removal efficiency. Nevertheless, in the adsorbent photocatalyst, there was an increase in removal efficiency with higher concentrations.According to the findings, the production of CO2 was dependent on toluene inlet concentration and the airflow. In the combined photocatalyst, the minimum and maximum of the produced carbon dioxide were 40 ppm and 80 ppm, respectively. And it was 84.82 in the optimum operational point (46.2 ppm; 5.62 L/min). However, in the non-combined reactor, the produced CO2 was 29.2 ppm in the optimum operational point and its minimum and maximum were 10 ppm and 25 ppm, respectively. The results also reported that in the given concentration and airflow, production of CO2 in TiO2-AC reactor was higher than TiO2.

Results of the present study indicated that combining titanium dioxide with activated carbon adsorbent is a useful method in removing toluene gas from air under UV and combining photocatalytic elimination with adsorption process by activated carbon led to increased removal efficiency. Self-cleaning photocatalyst had high efficiency in the present study and the use of photocatalytic-adsorption bed can as a suitable method with high removal efficiency causing adsorption and treatment of the pollutants. In other word, combination Activated carbon with Titanium dioxide improved the functionality of activity of photocatalytic oxidation through promoting adsorption sites and increasing residence time of the pollutant in the bed.Results also indicated that removal efficiency was influenced by initial concentration of toluene and retention time of pollutants on the bed and optimizing these parameters may lead to maximum efficiency in photocatalytic setups. The combined catalysts with surface adsorbents led to improved decomposition efficiency based on photocatalytic decomposition and it is likely that the improvement is mostly the result of increasing adsorption sites compared to limited adsorption sites found in the photocatalyst. On the other hand, with more adsorption site, the pollutant had much more time to have contact with photocatalysts and consequently improved circumstances for surface oxidation reactions Keywords: Indoor Air Quality (IAQ), Titanium Dioxide (TiO2), Activated Carbon, Volatile Organic Compounds, Toluene, Photocatalytic Oxidation, Adsorption-Photocatalytic bed.

Microwave radiations are one of the most environmental workplace factors that exposed too many workers. In microwave spectrum, radar frequency with 1-300 GHz range have varied applications such as satellite, communications, military, Network, navigation, air-traffic Control, navigation, marine and weather. Uncontrolled occupational exposure to radar radiation caused to various disease and disorders such as oxidative stress, different kinds of cancers and other thermal and non-thermal adverse health effects. Regard to the importance of identification work related carcinogenic factors in prevention and decreasing cancer related costs and lack of similar studies, this study was conducted to systematically review the research on the risk of cancer in occupational exposure to radar radiation with frequency ranges 1 to 3000 GHz.

The present systematic search was carried out based on PRISMA guidelines and comprehensive search strategy was focused from March 2017 to September 2018 and update on September 2018 in PubMed, ISI Web of Science, Scopus and Google scholar, MAGIRAN and SID databases with English and Persian articles without time limits were searched .Keywords were selected based on PICO principle and collected from MeSH database. comprehensive search  were accomplishment by the following search  terms  : (worker OR technician OR occupation OR military OR airline OR navy OR police officer OR  Weather )  AND (occupational exposure OR  workplace OR  long-term exposure OR  exposure  OR  radar OR  microwave OR  wireless OR  high frequency range OR  radiofrequency OR radiation OR  electromagnetic) AND (control group, cohort OR prospective OR retrospective OR follow-up OR randomized control trial OR case-control) AND (cancer OR malignant OR melanoma OR metastatic OR non-thermal effect OR biological effect OR health effect OR Adverse Effect OR risk factor OR Sarcoma OR tumor or leukemia OR neoplasm OR Carcinoma OR Hepatoma OR lymphoma OR mortality ) as single or complex terms in titles, abstracts and keywords.Then, taking into inclusion and exclusion criteria, the process of reviewing, screening and limiting the repeated and unrelated articles was carried out. In addition, manual references checking were done to retrieve the related articles. Also, any disagreements were resolved by consensus between reviewers.The inclusion criteria for selection studies were in design of case–control, cohort and randomized control trial studies, with control group and referring to the association between occupational exposure to radar radiation and all types of cancer in workers.The exclusion criteria were as follows: 1) studies without control group 2) reviews, case and field studies, 3) studies with inhumane population such as in vitro, in vivo and animal studies. 4) Studies that radar frequencies were out of considered ranges (1-300 GHz) .5) studies with other occupational or non-occupational carcinogenic risk factors (such as solvents, workplace air pollution, environmental air pollution, smoking and etc).After implementation of inclusion and exclusion criteria, data were extracted after preparation of the full text of included articles.

A total of 533 studies was found. After removal of duplicated references, 272 studies were included for the title, keywords and abstract screening. Then, 219 studies were excluded since they did not meet inclusion criteria. Hence, 53 studies were selected for the eligibility assessment. At the end of selection process and after the quality assessment, 7 studies remained in the systematic review that including 3 case-control studies and 4 cohort studies with no randomized control trial study. A manual search of the reference lists added no more articles in this review. All included studies were from English language and external databases in various countries including USA, Germany, and France. In this systematic review, a study of clinical trials and Persian studies were not found. Finally, based on inclusion and exclusion criteria, 7 articles (4 cohorts and 3 case-control) were included, which were conducted during the 1950 to 2005 with 51898 sample size and range of ages 15–69 years that published from 1993 to 2016. Included studies examined relationship between occupational exposure to radar radiation and cancer strength among workers. Whole of the studies put determination of cancers and risk estimates in military workers. The great majority of included studies reported risk estimates with 95% confidence interval. Most included studies were conducted on testicular cancer (4 from 7 included studies) and brain cancer (4 from 7 included studies). In included studies, Relative risk were estimated, particularly about testicular, leukemia and brain cancers and mortality ratio in various types of cancers has been reported. The included studies reported no significant increase in mortality ratio about testicular cancer but increasing in relative risk were significant in two studies. There was also a significant increase in the relative risk of brain cancer in workers who occupationally exposed to radar radiation. Increase in mortality ratio due to brain cancer were significantly reported in two included studies.

The current systematic review was carried out to investigate the cancer among workers with occupational exposure to radar radiation.It is noticeable that previous related studies focused on both environmental and occupational exposure in worker and public population and it clearly did not determine the relationship between occupational radar exposure and cancer risk in workplace. Whilst, our study just focused on occupational exposure to radar radiation that lead to small number of included studies.The results of this study can be useful to prepare the occupational health policies in related to radar radiation and provide some information to conduct associated meta-analysis in future studies. On the limitations of the included studies, the continuation of experimental studies on humans with control groups, and focusing on the study of cancer-causing radar radiation in occupational exposure to workers is necessary.in this line, World Health Organization propose to conduct further differences studies  especially case-control studies.However, it should be mentioned that these results are yielded by a few numbers of available studies with no report in occupational dose and time exposure to radar frequency range. also, considering to some limitation such as few numbers of included studies, lack of data about exposure characterizations (exposure time, dose-response, average of exposure level) and demographic characterizations (average of age, average of experience, radar frequency range) it is better to continue further studies about this topic and future review studies include the congress publications without limitation in language. It is also suggested that other published articles in congresses also be used and the limitation in language of publications in the search process be removed.It is noticeable that, slight researches about occupational cancers in Iran were conducted in yet, such as studies in related to asbestosis, aromatic amines and chromium. Therefore, regarding the fast growing of cancer in developing countries like Iran, determination of occupational cancer risk factors could be useful to provide the cancer prevention and control program. So in this line, designing epidemiologic studies to focus on occupational cancers are very important especially about microwave and radar radiation.

Background and Hospital-acquired infections, are the most important consequence in exposure to bioaerosols in which affect health of staffs and clients. The present study aimed to investigate the relationship between fungal bioaerosols and particulate matter in two educational hospitals in Qazvin city in 2017. This descriptive-analytical study, was performed in 12 of two hospitals indoor wards and outdoor air, during six months. Bioaerosols sampling was done by Quick Take-30 at an airflow rate of 28.3 L/min, for 5-10 min. determination of PM10 and PM2.5 concentrations conducted by a Micro-Dust Pro at flowrate of 3.8 L/min as µg/m3. The data were analyzed using SPSS version 20, non-parametric tests and Spearman's correlation. Results indicated that the highest and lowest of total of microbial density was for EMS1 and operating rooms. Peak of fungal bioaerosols was observed in women’s surgery1 (92.7 CFU/m3). Species of Aspergillus niger was the most frequency fungi. Significant correlation was observed between fungal concentration and PM10, temperature and humidity ratio (p<0.05). In this study the main sources of pollution were related to hospital wards. Thus suggests controlling of microorganisms of air by improving of ventilation system, observance of sanitary and cleanliness regulations and continual assessment of indoor air quality. Because of association between PM2.5 and PM10 and bioaerosols density, measurement of the particulate matter concentration can be used as an easy and quick tool for predicting of the air microbial contamination in healthcare centers.

Discharging compressed air through conventional single jet nozzles or open pipes is a common jet noise in industry. This study is aimed to reduce air blow gun jet noise by designing and fabrication of multiple jet nozzle as a substitute for conventional single jet nozzles. One of the most common commercial air blow gun equipped with a conventional single jet nozzles was considered as a reference. An air Nozzle’s three dimensional model with multiple and smaller openings was designed by solid works software and the designed sketch was fabricated by a three dimensional printer. Noise measurement was made by a Cassella Cell 450 sound level meter with one octave band analyzer. Noise absorption foams were applied to mitigate noise reflection in the testing environment. Air thrust was measured using a digital scale that was placed 30 cm away from nozzle tips. Multiple jet nozzle’s sound pressure level was measured significantly lower than conventional nozzle’s sound pressure level (P Value <0.04). Multiple jet and conventional nozzle’s average sound pressure level in various angles from nozzle axis (30, 90 and 135 degree) was measured to be 75, 76, 76 dB A and 78, 83.3 ,86.3 dB A in pressures of 2,4 and 6 bar respectively. Multiple jet nozzle’s noise reduction in frequencies higher than 500 Hz was significant in comparison with conventional nozzles. Conventional and multiple jet nozzle’s average air thrust in pressures of 2,4 and 6 Bar was measured to be 1.39 and 1.19 N respectively and there was no significant relationship between air thrusts (P Value = 0.7). Multiple jet nozzle with lower noise and the air thrust that is approximately equal to single jet nozzle, can be considered as an appropriate alternative for noise reduction in air blow guns

Using water pump in residential buildings to provide the required water pressure is accompanied by noise pollution and the annoyance of residents. So, the purpose of this study is to reduce water pump noise pollution with designed acoustic curtains in a residential building of Qazvin city.
The mean sound pressure level was measured before and after control intervention around the sound source based on ISO 9612, using the sound level meter (Casella-Cell.450). The sound level meter was calibrated using a calibrator(Cell-110/2). The frequency analysis was done in 1.1 octave band and the weighting frequency of A. Acoustical features of acoustic curtains (thickness, material and dimensions)were determined on the base of required sound transmission loss in predominant frequency. The volumetric flow of air required to decrease the temperature inside the enclosure up to 40°C to maintain a reasonable air temperature for pump performance was calculated using the energy-mass conservation law. Temperature inside the enclosure was measured with a mercuric thermometer.
The mean sound pressure level before and after control around the pump was measured 67 dBA and 46 dBA respectively. The required insertion loss in predominant frequency(2000 Hz) to accommodate noise limit in residential buildings was considered to be 26 dB and based on which acoustic curtain surface density was calculated between. The average sound pressure level measured after control(46dBA) with predicted sound pressure level by mathematical calculation after control(47dBA) was not significantly different. The volumetric flow rate required to maintain a temperature of 40°C inside the enclosure was calculated to be 1.2 cubic meters per minute. The temperature was measured inside the enclosure of 38° C.
Control of noise pollution using acoustic curtains with a lower cost and weight, higher installation speed and higher sealing can be considered as one of the proper methods for enclosing noise resources.

Nowadays, demand for protection against radar radiation using electromagnetic shielding is on the rise. Double-layer or multilayer shielding were devised in order to improve the single layer electromagnetic shielding properties. In this study, we tried to prepare a new double-layers electromagnetic shield and investigate the effect of structural factors such as thickness, similarity in layers and mixing time on the shielding effectiveness for double-layers shields.
Material and This study used the Resin Epoxy EI-403 and Nickel Oxide nanoparticles to prepare single layer shields by casting method (with two different mixing time: 10 and 66 min) in 2, 4 and 6 mm thicknesses and 7 wt% Nickel oxide nanoparticles. Then, in order to prepare double-layers shields, single-layer shields were placed on each other without air space. Scattering parameters were measured by a Vector Network Analyzer (V.N.A) and shielding effectiveness were calculated in X-band radar frequency range.
The highest and the lowest averages of shielding effectiveness in single layer shields were 84.14% and 46.05%, respectively. These values were 66.34% and 41.99 %, in double layers electromagnetic shields. The averages of shielding effectiveness values in the double-layers shields (with 10 min in mixing time) in 6, 8 and 10 mm in thickness were 41.99%, 45.45% and 43.25%, respectively. These values in 66 min in mixing time, increased to 54.30%, 62.07% and 66.34%, respectively.
In this study, the shielding effectiveness in double-layers were less than single layer electromagnetic shields. Although the increase in mixing time improved the shielding effectiveness of both single and double layer shields, it could not increase the shielding effectiveness in double layer shields in comparison with single layer. Also, the increase in mixing time in double-layer shields showed that shielding effectiveness decreased with increasing thickness in these shields. Also, it was seen that using a similar single-layer shield in the structural of a double-layer shield led to an increase in skin depth and multi reflections .It finally reduced the shielding efficiency in double layer. It is suggested that in the future, other studies be conduct to improve the shielding effectiveness in these electromagnetic shields.

Background and Fluoride is a major mineral pollutant in groundwater. Long-term exposure to high concentration of fluoride in drinking water causes dental fluorosis, skeletal and nonskeletal fluorosis. Therefore, highly efficient water treatment that could lower the concentration of fluoride in groundwater is a challenge. This study aimed at evaluating the efficiency of Nanofiltration and the effects of pressure and temperature on the removal of fluoride from groundwater.
The study was conducted in laboratory scale by pilot plant using Nanofiltration membrane (FILMTEC-NF90-4040). Raw water fluoride concentration was between 1.50 and 2.17 mg/L and pressures and temperatures were 4 to 12 bars and 10 to 30°C, respectively. Fluoride ion concentration was measured by spectrophotometry using a standard SPADNS method.
The lowest and highest efficiency rates in removal of fluoride were 30% and 70%, respectively. We also observed that increase in pressure and temperature increased efficiency and the membrane permeate flow rate. Fluoride concentrations in all water samples were less than standard levels.
Nanofiltration was found with favorable efficiency in removal of fluoride from groundwater. Operating pressure and temperature are amongst the parameters that affect the performance of the process and increase the efficiency of fluoride removal by Nanofiltration.

Introduction and Improper posture while working is one of the most important risk factors for musculoskeletal disorders. Regarding this, the aim of this study was to assess the posture of students studying at Qazvin University of Medical Sciences when using the existing best-selling laptop tables using rapid upper limb assessment (RULA) method.
This analytic, cross-sectional study was conducted on 50 male and female dormitory students in 2017. The study population was selected through stratified random sampling technique. The participants’ postures in two different work stations (tables number one and two) were evaluated by means of RULA method. Data analysis was performed in SPSS version 16 using the independent sample t-test and ANOVA test.
According to the results, 36% and 46% of the students obtained scores of 3 and 4, respectively in case of table number one. Furthermore, regarding table number two, scores 3 and 4 were recorded for 48% and 44% of the participants, respectively. Therefore, tables number one and two were found to have 82% and 92% of level two corrective measure, respectively. In addition, a significant relationship was obtained between the demographic variables and RULA score (P As the findings of the present study indicated, table number one was a better case than table number two for fitting with different body structures since it allowed for the adjustment of the height and inclination of the work surface. However, corrective measures were necessary for both tables to provide the users with comfort, convenience, health, and productivity when using these laptop tables.

The increasing use of wireless systems in educational and administrative environments has caused concern People working in these environments about the physical and psychological effects of the waves on health. This study was conducted to assess public exposure to microwave emissions intensity of the wireless system (Wireless) Qazvin University of Medical Sciences.
In this cross-sectional study, were measured the intensity of microwave radiation on 158 stations including the location of access points antennas, teachers room, meeting rooms, lecture classrooms, halls and nearby laptops in schools of Qazvin University of Medical Sciences. Wave intensity was measured using a wave control system (made in Spain) in accordance with standard procedures recommended by the National Institute of America IEEE C95.3. The effective intensity of exposure to microwave radiation emitted in the studied university was equaled to 0.121±0.437 μW/cm2 which was lower than the international exposure limits. Results also showed that there was a significant difference between the intensity of microwave with measurement points and Schools (pv

Objective (s): The purpose of this study was to evaluate the effectiveness of a theory-based educational intervention for increasing exercise to prevent osteoporosis in pre-menopausal women. This study used a randomized controlled design to evaluate an 8-week exercise education intervention program based on the Health Belief Model and Self Regulation construct to prevent osteoporosis in 140 pre-menopausal women. The results of post intervention and 3 months follow up revealed that individuals in the experimental group had a positive and significant progress, whereas no progression occurred in the control group. After the intervention, the experimental group demonstrated significant improvements in physical activity, muscle strength and feasibility, with no significant changes in the control group. These results support the applicability of the integrated model for a physical activity intervention in order to prevent osteoporosis in women.

Treatment of waste air containing volatile organic compounds (VOCs) using cheap and environmentally friendly methods is one of active fields in air pollution control. The aim of this study was to treat air containing triethylamine (TEA) vapor using biotrickling filter inoculated with microbial species decomposing TEA. This experimental study was conducted in the School of Health affiliated to Qazvin University of Medical Sciences in 2014. Biotreatment was performed with biotrickling filter inoculated with microbial species decomposing TEA for two months. The biotrickling filter was set up with air containing TEA as the sole source of carbon, at Empty Bed Residence Times (EBRT) of 36 sec, and inlet concentration of 84 ppm. Data were analyzed using descriptive statistics. Treatment of TEA contaminated air was made after an adaptation period of 11 days. Despite an increase in mass loading to 111 g/m3/h, TEA was eliminated with 109 g/m3/h capacity and 94-100% removal efficiency by zero order kinetics. Elimination capacity and removal efficiency were close to each other and confirmed109 g/m3/h as loading region with critical elimination capacity. With regards to the results, it is possible to treat air containing TEA vapor in biotrickling filter.

Patient safety is an important issue in regard to hospital servicesand any problem can cause adverse consequences. The purpose of this study was to assess the patients’safety culture at educational hospitals in Tehran. The present descriptive-cross sectional study was carried out among 312 health care workers in Baharloo, Amir Aalam, Shariati and Sina hospitals in Tehran, which were selected by cluster sampling. The participants were chosen randomly in each cluster. Safety Culture Survey questionnaire including 12 dimensions was used to assess patient safety culture. Cronbach’s alpha and test-retest coefficient were estimated 81 and 79 percent, respectively. Nurses comprised 61 percent of participants in the study. 42% of staff had less than 5 years work experience. Of the 12 dimensions of patient safety culture, the frequency of reporting and exchange of information had the minimum average of 56 and 55, respectively. Moreover, the dimensions of organizational learning and expectations-management measuresobtained the highestmean score (69)among 12 dimensions of patient safety culture. Total mean patient safety culture in understudy hospitals was 63. It should be noted that paying more attention to the patient safety culture can lead to improve hospitals condition, as a whole, and to have a patient-friendly environment. Special attention should be paid to dimensions with the lowest mean score in order to strengthen them.

The increasing use of productive machines with electromagnetic waves of different frequency and severity has led to perform many studies about the possible impact of the waves on the health of living creatures. The aim of this study was to investigate memory function and reminding in mice, exposed to microwave radiation with a frequency of 950 MHz (GSM signal). In this experimental study, 120 male mices were divided into 10 groups of 12 animals in each group. The exposed 9 groups were under microwave radiation at the power densities of 0.02, 1.3 and 8.6 mW/ cm2 and the time intervals of 2, 4 and 6 hours and one group was considered as control. The analysis of mice’s memory was done with the passive avoidance trial test and by measuring the frequency of animals entering the dark compartment of shuttle box and their entrance latency time in 6, 12, 24, 48 h, 1 and 2 weeks after the last learning stage. The results showed no significant changes among the latency time of animals in entrance to the dark side of compartment, but the frequency of entrance showed significant difference among the exposure groups with the potent of 0, 0.02, 1.3 and 8.6 mW/cm2. Memory function and analysis of animals exposed to mobile radiation show a decrease depending on exposure time and power. The increasing frequency of animal in entrance to the dark field with the memory of electrical shock should be a sign of animal memory impairment with the exposure to the microwave mobile radiation.

there is a great concern for the possible adverse effects of cell phones and noise waves and it looks these weaves effects on the individuals’ health. Thus, the present study was conducted to examine the effect of cell phone waves, severity noise, and simultaneous effect of cell phone waves and severity noise on sperm motility and sexual hormones in adult male rats. this experimental study was performed on twenty eight Wistar adult male rats (200-250 gr). The animals were randomly assigned to four groups (n=7): control group, two-week exposure to cell phone simulated waves group, exposure to noise group, and simultaneous exposure to cell phone simulated waves and sound group. The means of sperm motility in all groups were determined with criterions of WHO and sexual hormones concentration of blood plasma in all groups were determined by RIA. The results were analyzed by one-way ANOVA statistical technique followed by Tukey test using SPSS (version 16) software. sperm motility in the exposure to cell phone simulated waves and simultaneous exposure to cell phone simulated waves and noise groups decreased significantly compared to control group (P<0.05). The testosterone hormone concentration of blood plasma in all exposure groups decreased significantly compared to control group (P<0.05). exposure to cell phone waves and simultaneous exposure to cell phone simulated waves and sharp noise can cause a significant decrease in sperm motility and also, can cause a significant decrease the testosterone hormone concentration in adult male rats resulting in abnormality fertility.

According to the World Health Organization (WHO) reports, the number of patients with diabetes will be doubled by 2050 to reach 250 million. This study aimed to assess the effect of low-power laser, with power of 5 mW, wavelength of 632.8 nm and energy of 4 j/cm2, on wound healing and blood sugar of normal and diabetic rats. 36 male rats, weighing 200 to 250 g, were divided into 4 groups including 9 animals in each group. Groups I and II were considered as two control groups. Group I was the control group without skin wound (normal control) and group II with skin wound (sham operated) treated using laser. Group III was considered as diabetic with skin wound, and group IV with skin wound treated by low-power laser with a wavelength of 632.8 nm and a power of 5 mW. In the time scales of 4, 7 and 10 days after surgery, the wound area was measured to calculate wound healing. Blood sugar levels and urine hydroxyproline were measured via colorimeter. The wound healing in the 7th day of treatment in both second (healthy laser) and forth (diabetic laser) group was significant in comparison with the control group (P < 0.05 and P < 0.01, respectively). On the 10th day, wound healing showed significant difference in the mentioned two groups (P <. 0.05 for both) and third group (P < 0.01) in comparison with the control group. The laser treatment in the wavelength of 632.8 nm, power of 5 mW and energy of 4 j/cm2 showed significant effect on blood sugar levels and wound healing in a time-dependent manner in both normal and diabetic rats. Laser healing effects was confirmed using both histological and biochemical studies on hydroxyproline concentration in the treated groups.