21 research outputs found

    Optimization of metal working fluids treatment using calcium chloride by response surface methodology

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    Background: Extensive use of metal working fluids degrades their chemical composition. They should be treated using a safe method. Chemical coagulation-flocculation process is one the treatment methods. Objective: The aim of this study was to optimize the coagulation-flocculation process using calcium chloride in metal working fluids treatment. Methods: This laboratory based study was performed in School of Health affiliated to Qazvin University of Medical Sciences in 2014. Using calcium chloride and a six-compartment jar, the efficiency of coagulation-flocculation process was assessed for removal of chemical oxygen demand (COD) and turbidity and amount of released oil. Central composite design (CCD) and response surface methodology (RSM) were applied to optimize the treatment operation parameters (pH and dosage of coagulant). Quadratic models were developed for calculation of the three responses (COD, turbidity, and released oil). Findings: The optimum condition for coagulation-flocculation process was seen after treatment with 4.2 g/L calcium chloride at pH 3.71 in which COD and turbidity removal efficiency were 93% and 96.9%, respectively and the amount of released oil was 31.8 ml. The level of desirability was 91.2%. The values of laboratory study were in good agreement with the values predicted by the model. Conclusion: Metal working fluids treatment with calcium chloride was efficient in the removal of pollution parameters. Dosage of calcium chloride was similar to the conventional coagulants such as Alum, but its efficiency was higher. Keywords: Treatment, Metal Working Fluid, Flocculation, Calcium Chloride, Response Surface Methodolog

    Amphistome Species in Cattle in South Coast of Caspian Sea

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    Background: Knowledge about the amphistomid fauna in Iranian domestic ruminants depends on the studies conducted almost 30 years ago. The last situation in cattle is introduced here in the provinces in south coast of Caspian Sea.Methods: Amphistomid species were collected from cattle at slaughter houses of the provinces Gilan and Mazanderan in 2010. Median sagittal sections were prepared by the conventional method. Species were identified by the histomorphological pecularities of the muscular argans.Results: Five amphistomid speciesrum Carmyerius spatiosus and Gastrothylax compressus, recovered. Calicophoron calicophorum is a new species for Iran. Criteria used in identification of the species were illustrated.Conclusion: Iran has a rich amphistomid fauna and mostly under the influence of oriental conditions

    Optimization of metal working fluids treatment using calcium chloride by response surface methodology

    No full text
    Background: Extensive use of metal working fluids degrades their chemical composition. They should be treated using a safe method. Chemical coagulation-flocculation process is one the treatment methods. Objective: The aim of this study was to optimize the coagulation-flocculation process using calcium chloride in metal working fluids treatment. Methods: This laboratory based study was performed in School of Health affiliated to Qazvin University of Medical Sciences in 2014. Using calcium chloride and a six-compartment jar, the efficiency of coagulation-flocculation process was assessed for removal of chemical oxygen demand (COD) and turbidity and amount of released oil. Central composite design (CCD) and response surface methodology (RSM) were applied to optimize the treatment operation parameters (pH and dosage of coagulant). Quadratic models were developed for calculation of the three responses (COD, turbidity, and released oil). Findings: The optimum condition for coagulation-flocculation process was seen after treatment with 4.2 g/L calcium chloride at pH 3.71 in which COD and turbidity removal efficiency were 93% and 96.9%, respectively and the amount of released oil was 31.8 ml. The level of desirability was 91.2%. The values of laboratory study were in good agreement with the values predicted by the model. Conclusion: Metal working fluids treatment with calcium chloride was efficient in the removal of pollution parameters. Dosage of calcium chloride was similar to the conventional coagulants such as Alum, but its efficiency was higher

    The acoustic performance of 3D printed multiple jet nozzles with different configurations

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    This work investigated multiple jet nozzles with various geometrical shape, number of exits, and material on reducing noise radiated from jet flows. Nozzles are categorized in two groups with few and many exit numbers, each with various exit shapes, slot and circular, and geometry. Firstly, nozzles are designed and then fabricated by a 3D printer, Form Labs, Form2USA, with polymeric resin. Also, the nozzle with the most noise reduction made of stainless steel. Noise and air thrust were measured at three air pressure gauges, 3, 5, 7 BAR and directions from nozzle apex, 30°, 90°, 135°. Nozzles with slot exit shape made of both plastic and stainless steel revealed the most noise reduction among all nozzles with few exit numbers, nearly 11-14 dB(A) and 11.5-15 dB(A), respectively. On average, slotted nozzle noise reduction was nearly 5-6 dB(A) more than finned nozzle. However, nozzles with more exit numbers, finned and finned-central exit, illustrated much more noise reduction than nozzles with few exit numbers, by almost 16-18 dB(A), they represented similar sound. All tested nozzles and open pipe demonstrated equal air thrust at each pressure gauges. The nozzles with slotted exit shape, either plastic or stainless steel, can provide reasonable noise reduction in comparison to other configuration with few exit numbers. In contrast, nozzles with more exit numbers demonstrated the most noise reduction. © 2020 Tech Science Press. All rights reserved

    Review the Proportion of university seats with body dimensions of students at the School of Public Health of Qazvin University of Medical Sciences in 1388

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    Background and aims   Educating of students that have the ability to solve society problems, is considered as the most important task of universities. This important issue is achieved through effective education in a safe and stress free environment. Proper design of classroom seats proportional to anthropometric characteristics of students not only can improve academic quality but also prevent musculoskeletal disorders. In addition it may encourage students to practice correct sitting habits. This study was conducted to check the correlation of physical dimensions of students and prevalence of musculoskeletal disorder with educational chair dimensions that provided by companies.   Methods   This descriptive - analytical study was performed on 115 students of 18 to 27 years. 15 anthropometric parameters correlated with sitting on the chair were measured by anthropometry page and anthropometric caliper gauge. Dimensions of two Types of seats provided in the classrooms were compared with the standard seat dimensions.   Results   comparison of dimensions confirmed that seat dimension and students dimensions correspond with one another only in elbow length parameter and other parameters were not correspondent with each other. T-Test showed that there are significant  differences between girl and boy parameters.  conclusion   Comparison of the results of measurement of  physical dimensions and chair dimensions with results of emotional dissatisfaction questionnaire and body map chart showed that plastic chair is better than wooden type in term of comfort, chair kind and slope of back rest, and in using plastic chairs students do not have to change their sitting postures; however,  due to incorrect design of foot rest and high effective depth of sea,،  discomfort and pain in lower limbs is higher in plastic chairs when compared with wooden chairs

    Risk assessment in a foundry unit by energy trace and barrier analysis method (ETBA)

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    Background and aimsAs a Development of Industrial process, human, environment,equipment, material and validity of system has been exposed to hazardous conditions. Regards of32.3 percent of occupations in industries, this study focused on risk assessment of foundry unit byenergy trace and barrier analysis (ETBA) method and presented approaches to control of accident.Methodsthe recent study is as a case study one to risk assessment in a foundry unit in Qazvinindustrial city in1387. In this study risks were founded by ETBA method and evaluated by MILSTD-882B. Data were collected by direct observations, interview with workers and supervisorand engineers, walking-talking through method, documents investigation of operationalprocessors, preventive maintenances, equipment technical properties, accidental and medicaldocuments. Finally ETBA worksheets completed.Findingstotally 154 risks has been found. 40 from total are been unacceptable risk, 68unfavorable and also 46 acceptable but with remediation action. Casting workshop had risks morethan other workshops (with 74 identified risks).Potential and heat energies were founded as mosthazardous energies, with respectively 51 and 38 risk cases.ConclusionThis study recommended to be done actions for identification and control risk,such as: safety training, occupation training, preventive maintenance, contract safety, safetycommunication and safety audit group

    Review the proportion of university seats with body dimensions of students at the school of public health of qazvin university of medical sciences in 1388

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    Background and aim: Educating of students that have the ability to solve society problems, is considered as the most important task of universities. This important issue is achieved through effective education in a safe and stress free environment. Proper design of classroom seats proportional to anthropometric characteristics of students not only can improve academic quality but also prevent musculoskeletal disorders. In addition it may encourage students to practice correct sitting habits. This study was conducted to check the correlation of physical dimensions of students and prevalence of musculoskeletal disorder with educational chair dimensions that provided by companies. Method: This descriptive - analytical study was performed on 115 students of 18 to 27 years. 15 anthropometric parameters correlated with sitting on the chair were measured by anthropometry page and anthropometric caliper gauge. Dimensions of two Types of seats provided in the classrooms were compared with the standard seat dimensions. Results: comparison of dimensions confirmed that seat dimension and students dimensions correspond with one another only in elbow length parameter and other parameters were not correspondent with each other. T-Test showed that there are significant differences between girl and boy parameters. Conclusion: Comparison of the results of measurement of physical dimensions and chair dimensions with results of emotional dissatisfaction questionnaire and body map chart showed that plastic chair is better than wooden type in term of comfort, chair kind and slope of back rest, and in using plastic chairs students do not have to change their sitting postures; however, due to incorrect design of foot rest and high effective depth of sea,' discomfort and pain in lower limbs is higher in plastic chairs when compared with wooden chairs

    Evaluation of Nuisance Dust Health Effects on the Workers in a Tile Industry

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    Background and objectivesAir pollution in the occupational fields and its economical effects on the health care system is studied from different viewpoints such as products quality, equipment damage, environment preservation, and air pollution control. Nowadays, a lot of attention has been turned toward health effects of air pollution. The objective of this study is detection of the total dust concentration and assessment of the health effect of nuisance dust among workers in a tile production factory.MethodsIn this study airborne dust concentration was measured and evaluated by using NIOSH 0500 method. In order to determine the health effects, a standard questionnaire was used. All of personnel of workshop 1 (n=50) and workshop 2 (n=50) were assigned to the case group and one hundreds of factory employees were assigned to the control group. Results analyzed using Z test.ResultsAccording to the obtained results, concentration of dust in workshop 1 corridor was higher than that of workshop 2 corridor (59.262 mg/m3 and 32.158 mg/m3 respectively). Also, these results showed that there are significant differences between two groups in incidence of symptoms such as dry cough, eye irritation, skin redness, shortness of breath, blurred vision, skin irritation, hoarseness of voice, dry mouth and throat, throat itching and skin itching (P<0.05). However, there were not significant differences in incidence of headache, chest pain, epiphora of eyes, mucus cough, sinus problems and chest wheezing between two groups.ConclusionOn the basis of these results it was revealed that nuisance dust can affect human health and performance. This in turn can increase the medical service load and costs. As a result of inadequate control systems established in the industries, lack of information and appropriate training, and lack of personal protective equipment all across the industries, we suggest a more comprehensive research project to evaluate the effects of industrial air pollution on the workers in order to improve quality of their lives and work.Keywords: Air Pollution; Dust; Nuisance; Health Effects; Tile Industr

    The Study of Refractive Errors among Carpet Weaver Women in Rural Sephidehkesh of Qazvin, Qazvin, Iran

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    Background and Objectives: Carpet weaver women due to long working in inappropriate environment are at risk for certain eye disease. The aim of this study is to determine the refractive errors among carpet weavers women in rural Sephidehkesh of Qazvin.Methods: 28 Carpet weaver women were under optometric eye examinations. Light Intensity at work stations was measured, using luxmeter and eye examinations were done by using the ophthalmoscope and retinoscop. Data were analyzed using one-side T-test.Results: The result of this study showed, general and local light intensity in 13 carpet weaving workshops, respectively 160 and 154 Lux that was much less than the minimum and maximum recommended values of 200 to 300 Lux. Only one of 28 Carpet weaver women was healthy and others were visually impaired. In addition to poor eyesight, workers complained of headache, itching and burning eyes.Conclusion: The results show, due to inappropriate working condition in carpet weaving workshops, most young workers are suffering from eye impairment and is predicted the severity of myopia to increase with working experience and age
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