غلامرضا ابراهیم زاده

Background & objectives:

Considering the importance of sanitizing vegetables before consumption, this study aims to evaluate the effectiveness of different stages of the most common vegetable disinfection methods in Iran in reducing total coliform and fecal coliform for the most consumed edible vegetables.

Three stages of disinfection were done, including
Scraping and pre-wash of vegetables (first step),
Separation of parasites by 3-5 droplets of detergent per liter for 5 minutes (second step), and
Disinfection of vegetables with calcium hypochlorite solution (200 mg/l free chlorine) for 5 min (third step).
Finally, disinfected vegetables were washed out with water. MPN test was used to determine total and fecal coliform. The efficiency of each stage was determined using the difference between total and fecal coliforms before and after each and total disinfection stage. 

The fecal coliform amount did not reach zero even after all the disinfection steps in vegetables with more foliage and hidden holes (such as basil and onion). Besides, according to this study's results, radish, onion, and coriander leaves had the highest contamination, and lettuce had the lowest total and fecal coliform. The highest total coliform removal efficiency related to beets (93.3%) was obtained under calcium hypochlorite disinfection, and the highest fecal coliform removal efficiency related to leeks, parsley, and beets (100%) under calcium hypochlorite disinfection.

To achieve the highest efficiency in reducing microbial agents in vegetables, it is necessary to complete the different disinfection stages following its instructions. In this regard, the efforts of the media and health experts are essential.

Nowadays, the COVID-19 pandemic has become a global problem that new methods must be used to prevent it. The virus is highly contagious and is mainly transmitted through the air. Ozone is a powerful oxidant that can be used to inactivate a wide range of viruses that may be resistant to other disinfectants. The purpose of this study was to review the use and effect of ozone in inactivating indoor viruses.

To conduct this review study, the keywords such as ozone, virus and air were used to search the PubMed and Scopus databases. Articles were searched from 2010 to 2020. As a result of the search, 57 articles in this field were selected and their content and results were used in this review study. 

This review study showed that ozone has been successfully used to prevent several viral diseases such as COVED-19. In addition, some viruses, such as coronaviruses, contain sulfhydryl functional groups containing cysteine and tryptophan that react better with ozone gas. The infected person's sneezing may result in the formation of 40,000 droplets in the air. The droplets can be transferred to the nearest surface up to approximately 2 meters before falling and also may remain in the air for 30 hours.

The use of ozone gas has many potential applications in inactivating viruses in enclosed spaces. Given the importance of virus-containing aerosols in the transmission of COVED-19, ozone can be a promising way to prevent the disease. The degree of inactivation of viruses by ozone gas depends on the gas concentration, contact time, temperature, humidity and type of virus. In general, studies in this field have shown the use of ozone gas in preventing the spread of viral diseases such as COVED-19. Necessary safety measures and precautions are also recommended in using this gas.

The purpose of the present study was to develop a causal model of academic satisfaction based on academic self-confidence and academic optimism mediated by cognitive strategies among male students.

The research method was correlational descriptive type. The statistical population included male high school students in Hamedan in the academic year 2019-2020. The sample size consisted of 338 persons which were selected randomly through two-stage cluster sampling method. The research tools included Lent et al satisfaction questionnaire, Azadichrs academic self-confidence, Tschannen‐Moran et al Academic Optimism Scale, and Karamichrs meta-cognitive strategies. Data were, then analyzed by means of structural equation modeling approach.

The findings obtained from statistical analysis showed that there was a significant causal relationship between academic self-confidence and academic optimism with metacognitive strategies and academic satisfaction. It was also found that the causal relationship between metacognitive strategies and academic satisfaction was significant.

Finally, the results emphasized the mediating role of metacognitive strategies in establishing the relationship between these variables. Based on the findings, it is suggested to use metacognitive strategies, academic self-confidence and academic optimism to increase studentschracademic satisfaction.

The aim of this study was to investigate the development of a causal model of academic satisfaction based on academic self-confidence and academic optimism through the mediation of metacognitive strategies and its effectiveness on academic Self-actualization of male high school students in Hamadan. This research was conducted in two stages. The research method was descriptive-correlational in the first stage. The second stage was a quasi-experimental research method with a pretest-posttest design with a control group. Using the available sampling method, in the first study, 338 people were selected as the statistical sample size based on Morgan table, and in the second study, 30 people (15 people in the experimental group and 15 people in the control group) were selected as the statistical sample size. ) were chosen. The experimental group received 10 sessions of 90 minutes and the control group did not receive training. Research tools in this study include the standard questionnaire of student satisfaction (Lent, 2017), the questionnaire of academic self-confidence (Azadi, 1394), the questionnaire of academic optimism (Schennemoran et al., 2018), the questionnaire of academic Self-actualization (Silson and Salasi, 2003) and The questionnaire was metacognitive strategies (Karami, 2015). In this study, structural equation modeling and analysis of covariance were used to analyze the data. It should be noted that these analyzes were performed with the help of SPSS and AMOS software version 23 at the error level of 0.05. Findings showed that academic self-confidence and academic optimism have a significant causal relationship with metacognitive strategies and academic satisfaction. It was also found that the causal relationship between metacognitive strategies and academic satisfaction is significant. Finally, the results confirmed the mediating role of metacognitive strategies in the relationship between these variables. The results also showed that the educational program based on academic satisfaction is effective on students' academic Self-actualization.

Phosphorus is a common ion in wastewater treatment effluents, but excess amount of phosphate concentration in the effluent discharge accelerates eutrophication that affects many natural water bodies. Eutrophication of the water bodies is one of the most important environmental problems. Eutrophication can lead to abundant development of aquatic plants, growth of algae and disturbance to the balance of organisms present in the water. Therefore, in present work, natural and modified yellow and red soil with EDTA was used for removal of phosphorous from aqueous solution.
All experiments were conducted in a batch system. Natural yellow and red soil and its modified one with EDTA were used as adsorbent for removal of phosphorous from aqueous solutions. Effect of various experimental parameters such as pH, initial phosphorus concentration, contact time and adsorbent mass were investigated.
Results showed that the removal efficiency was increased by increasing in contact time, adsorbent mass and initial phosphorus concentration. Higher removal efficiency was observed at 150 min contact time, 10 g/L adsorbent mass, 50 mg/L phosphorus concentration and pH 5. At these conditions, about 65% of phosphorus were removed by natural soils, while 78% was removed by modified adsorbents.
The results of present work well demonstrate that, due to higher content of calcium, red and yellow soil is capable for adsorption of phosphorus and if they be modified with EDTA, their efficiency will be improved remarkably.

Reservoirs and lakes Supply sufficient water for various purpose such as drinking، industry and agriculture. These types of water exposed constantly to variety of pollution. Due to the critical situation of these resources and the lack of previous Studies، in this research concentration of chromium، cadmium، zinc، copper، Nickel، lead، iron and manganese in vertical profile of chahnimeh’s water (no. 3) were investigated. Materials: The Cross - sectional research was performed from April to October 2012 on water of chahnimeh (no. 3) sabot. For this purpose 96 samples were collected from the depths 1، 3، 5، 7، 9، 11، 13، 15 meters and concentration of heavy metals measured by atomic absorption. The results were analyzed by using descriptive statistics and ANOVA test with regard to the significance level P < 0. 05. The average concentration of heavy metals was 0. 098، 0. 05، 0. 04، 0. 04، 0. 013، 0. 006، 0. 002 and zero mg/l for Nickel، zinc، iron، copper، chromium، lead، manganese and cadmium، respectively. In comparison of results with ISIRI recomendatins are concluded that concentration of all heavy metals except Nickel were acceptable. Significant correlation (P < 0. 05) was not observed between the concentration of heavy metals and depths. The results indicated that no significant heavy metals pollutions in the reservoir were available.

Triethyl phosphate (TEP) is one of the most important organophosphate pollutants, used as an industrial catalyst, a polymer resin modifier, an intermediate in the synthesis of pesticides (and other chemicals), and a peroxide stabilizer. The photocatalytic process is based on the irradiation of a semi-conductor compound with ultra-violet lights and subsequent production of high-energy hydroxyl radicals. In this study, the removal of TEP from aqueous solutions was investigated, using photocatalytic oxidation process. Photocatalytic removal of TEP by zinc oxide nanoparticles was studied using a batch reactor, equipped with a UVC lamp at room temperature (25 °C). Parameters affecting the removal of TEP including zinc oxide concentration (700-1200 mg/L), pH (3-10), initial concentration of TEP (30-80 mg/L), and contact time (30-180 min) were investigated. The results showed that the maximum removal rate of TEP is obtained at pH=7, initial concentration of 40 mg/L, nanoparticle dosage of 1200 mg/L, and contact time of three hours. This study showed that organophosphates can be almost completely removed from water in a short time by using photochemical oxidation.

Because of entering organic material and mud, lakes and reservoirs are naturally subject to change. Entrance of macro nutrients (nitrogen and phosphorus) into reservoirs and lakes, leading to the changes in the quality of water. Therefore, this study aimed to determine the parameters of water quality assessment was conducted in 2012 in Zabul of Chahnimeh. In this cross sectional study that was performed for eight months, from early April to October 2012, on water reservoir of Chahnimeh 3 of city of Zabol. At present study every 15 days, samples were collected from the bottom of the reservoir using Nansn bottle and then temperature, turbidity, dissolved oxygen, heavy metals, phosphorus and coliform bacteria levels were measured in the laboratory according to standard procedures. Also, SDT parameter was measured by secci disk. Data collected by spss software using descriptive and analytical statistics were analyzed by statistical tests, one sample t test, and p <0.05 was considered as significant. The mean concentrations of nitrate, phosphate, COD and dissolved oxygen concentration were 11.17, 0.02, 21.13 and 8.7 mg/L, respectively. Average total dissolved solids, sulfate, nitrate and total hardness, respectively, 450/43, 138/41, 11/17, 199/40 mg /l, respectively. Average total coliform and E.coli coliform bacteria in 27/1and 1/1, and a significant relationship between water chemistry values were observed for all parameters (p <0.05). The mean results for all parameters in the standard range and Utility were of drinking. The estimation of reservoir water showed water quality management plan for the protected Chahnimeh 3 requires further.