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متن کامل


نویسندگان: 

نشریه: 

Environ Proces

اطلاعات دوره: 
  • سال: 

    0
  • دوره: 

    7
  • شماره: 

    4
  • صفحات: 

    1111-1127
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    116
  • دانلود: 

    0
کلیدواژه: 
چکیده: 

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بازدید 116

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اطلاعات دوره: 
  • سال: 

    1401
  • دوره: 

    12
  • شماره: 

    47
  • صفحات: 

    33-54
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    168
  • دانلود: 

    22
چکیده: 

Improving participation in voluntary activities in Iran is important because increasing productivity among young people, given the country's young population, contributes to community sustainability. Therefore, a better understanding of volunteer motivation in Iranian youth is needed. The Volunteer Functions Inventory (VFI) for assessing volunteer motivations has good psychometric properties and is adapted to several languages, but no validated Iranian translation yet exists. The purpose of this study was to investigate the psychometric Characteristics of voluntary functions inventory in members of Iranian RED Crescent Society. Sample size was 595 members of Youth Organization of Iranian RED Crescent Society from 31 provinces and 175 cities of Iran that were selected by multi-stage cluster sampling method and responded to voluntary functions inventory. Data were collected using a demographic sample and voluntary functions inventory (VFI). Confirmatory factor analysis using principal components method was used for data analysis. The results of the present study showed that the voluntary functions inventory had validity and reliability. Also, the factor structure showed that 29 items and 6 factors well assess people's attitudes to volunteering, and the structure of this inventory was well-fitted and confirmed all goodness of fit models. The present study provides the use of the Iranian translation of the Voluntary Functions Inventory (6 scales and 29 items) to assess volunteer motivation among young Iranian volunteers.

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نشریه: 

علوم زمین

اطلاعات دوره: 
  • سال: 

    1390
  • دوره: 

    20
  • شماره: 

    80
  • صفحات: 

    113-118
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    1491
  • دانلود: 

    412
چکیده: 

معدن بوکسیت جاجرم به عنوان بزرگ ترین معدن بوکسیت شناخته شده در ایران با ذخیره بیش از 20 میلیون تن بوکسیت دیاسپوری در استان خراسان شمالی واقع شده است که توان تامین خوراک کارخانه آلومینای جاجرم را برای یک دوره 20 ساله ندارد. در همین راستا به بررسی امکان استفاده از بوکسیت معادن شاه بلاغی در استان تهران و سرخ چشمه در استان خراسان شمالی پرداخته شد. در این پژوهش بوکسیت ها از نظر مسائل فرایندی تولید آلومینا مانند انحلال و ته نشینی گل سرخ مورد ارزیابی قرار گرفتند. نتایج آزمایش های انجام شده نشان داد که استفاده از این ذخایر به دلیل پایین بودن بازده انحلال و سرعت ته نشینی گل سرخ به تنهایی امکان پذیر نیست. از این رو متغیرهای دیگری نیز مانند دمای انحلال، درصد سنگ آهک افزوده و غلظت Na2Oc تحت کنترل و ارزیابی قرار گرفتند. آمیختگی 50-50 بوکسیت شاه بلاغی با جاجرم دارای بهترین نتیجه به همراه بالاترین بازده انحلال و کمترین تلفات آلومینا در گل سرخ بود.

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مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources
اطلاعات دوره: 
  • سال: 

    2013
  • دوره: 

    10
  • شماره: 

    2
  • صفحات: 

    305-314
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    305
  • دانلود: 

    0
چکیده: 

In this study, feasibility of using seawater to neutralize alkaline RED MUD for its safe disposal has been studied using Taguchi’s design of experimental methodology. Parameters such as weight of RED MUD, volume of seawater, stirring time and temperature were tested at three levels to study their effect on response characteristic, i.e., pH of the neutralized slurry. The analysis of variance showed that volume of seawater added and quantity of RED MUD are the two significant parameters with 53.59 and 44.92% contribution each, respectively. Under the optimized parameters, pH value of RED MUD slurry reaches to about 8.0 which is within disposable limits. When seawater or other Ca- and Mg-rich brines are added to caustic RED MUD, the pH of the mixture is REDuced causing hydroxide, carbonate or hydroxy carbonate minerals to be precipitated. This mechanism of neutralization process has been explained with emphasis on chemical analysis, mineralogy and morphology of the neutralized RED MUD. The process improved the physical characteristics of RED MUD with entrained liquor becoming non-hazardous water with REDuced alkalinity. The results would be extremely useful in the process of safe disposal of RED MUD.

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اطلاعات دوره: 
  • سال: 

    1392
  • دوره: 

    2
  • شماره: 

    1
  • صفحات: 

    1-11
تعامل: 
  • استنادات: 

    4
  • بازدید: 

    926
  • دانلود: 

    186
چکیده: 

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اطلاعات دوره: 
  • سال: 

    2013
  • دوره: 

    1
  • شماره: 

    1
  • صفحات: 

    36-43
تعامل: 
  • استنادات: 

    4
  • بازدید: 

    459
  • دانلود: 

    0
چکیده: 

Background: and purpose: Dye is one of the problems of industrial effluent such as textile industries. The dyes can be removed by various methods. Therefore, the aim of this study was the evaluation of adsorption rate of reactive RED 198 from aqueous solution by activated RED MUD.Materials and methods: This research was a lab study. Activated RED MUD was used as an adsorbent to remove reactive RED 198 dye. The effect of various parameters on performance of adsorbent was investigated and the isotherm of adsorption was determined. The dye concentration was measuRED in wavelength of 518 nm by spectrophotometer.Results: The results indicated that the adsorption efficiency REDuced by increasing of initial dye concentration. Increasing of contact time and adsorbent dose can lead to increasing of the removal efficiency. The maximum removal efficiency was occurRED pH between 2 to 3. The data was best fitted on Frandlich and Temkin isotherms.Conclusion: The RED MUD had a satisfactory quality in dye adsorption. It can be used as effective and inexpensive adsorbents for treatment of textile effluent.

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مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources
اطلاعات دوره: 
  • سال: 

    2023
  • دوره: 

    14
  • شماره: 

    4
  • صفحات: 

    1295-1305
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    27
  • دانلود: 

    0
چکیده: 

RED MUD is an important solid tailing with strong alkalinity that is obtained during the extraction of alumina in the Bayer process. The global reserve of RED MUD is more than 4 billion tons, and its disposal as tailing has always been a serious environmental problem. This tailing is consideRED as a potential source, due to its high content of valuable metal compounds including iron. In this research work, the extraction of iron in RED MUD is investigated by the method of REDuction roasting. The main influencing factors are also investigated. These methods include REDuction in muffle and tube furnace, and temperature, REDuction agent, and additive type are as important factors. REDuction roasting of the samples in a tube furnace, with Argon gas and vacuum, a mixture of RED MUD, graphite, and sodium carbonate at 700–1000 °C results in the formation of Fe3O4. Magnetic measurements indicate that saturation magnetization increases from 0.239 to 38.205 emu/g due to the formation of Fe3O4. Applying the magnetic field intensity of about 1000 Gauss results in the iron recovery of 89.9%.

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بازدید 27

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نویسندگان: 

WIWANITKIT V.

اطلاعات دوره: 
  • سال: 

    2008
  • دوره: 

    2
  • شماره: 

    2
  • صفحات: 

    0-0
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    327
  • دانلود: 

    0
چکیده: 

Erythrocyte SEDIMENTATION rate is an important laboratory test in hematology. Inclusion body is an abnormal addition within RED blood cell that can occur in cases of many abnormalities. Inclusion body is an object and has mass therefore, it poses its specific weight which can modify the normal SEDIMENTATION of RED blood cell. Here, the author proposed the mechanism that REDuce the erythrocyte SEDIMENTATION rate in splenectomized thalassemia and further imply for other conditions with inclusion body in RED blood cell. It can demonstrate that the increase of additional mass due to inclusion body can REDuce the time for SEDIMENTATION.

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بازدید 327

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اطلاعات دوره: 
  • سال: 

    1393
  • دوره: 

    21
  • شماره: 

    4
  • صفحات: 

    677-684
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    1458
  • دانلود: 

    306
چکیده: 

مواد معدنی موجود در پوسته زمین بسته به ترکیب و خواستگاهی که دارند حاوی مقادیری از رادیونوکولئیدهای پرتوزا هستند. حضور این رادیونوکلوئیدها پیوسته بر میزان دوز دریافتی انسان از محیط تاثیر گذاشته و می تواند در سطوح بالا خطر زا باشند. بوکسیت به عنوان ماده معدنی خام تولید آلومینیوم حاوی مقادیر نسبتا بالایی از این رادیونوکلوئیدها است. فرآیند برداشت بوکسیت می تواند باعث تمرکز بیشتر این رادیونوکلوئیدها در باطله آن یعنی گل قرمز شود. برای کاهش مخاطرات زیست محیطی گل قرمز و نیز به خاطر دارا بودن مقادیر بالای اکسیدهای آهن، از گل قرمز در صنایع سیمان و آجرسازی استفاده می شود. به لحاظ بالا بودن سطح پرتوزایی گل قرمز، باید پیش از استفاده در صنایع، سطح پرتوزایی آن از نظر شاخص ها و استانداردهای وابسته مورد ارزیابی قرار گیرد. از این رو در این پژوهش پرتوزایی نمونه های بوکسیتی و گل قرمز معدن بوکسیت جاجرم را که بزرگ ترین ذخیره بوکسیت ایران است و سالانه حدود 1000000 تن گل قرمز تولید می کند، از نظر شاخص های زیست محیطی مورد بررسی قرار داده ایم. در نهایت با توجه به میانگین سطح پرتوزایی اندازه گیری شده گل قرمز، نسبت اختلاط گل قرمز با خاک رس برای ساخت مصالح ساختمانی با سطح پرتوزایی پایین تر از حد مجاز مورد محاسبه قرار گرفت.

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اطلاعات دوره: 
  • سال: 

    2014
  • دوره: 

    11
  • شماره: 

    4
  • صفحات: 

    10-20
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    769
  • دانلود: 

    0
چکیده: 

In this work, the influence of RED MUD in the pyrolysis of general purpose polystyrene (GPPS) has been studied. The catalytic pyrolysis experiments were carried out using an unstirRED semi-batch stainless steel 6.28 liter reactor under nitrogen atmosphere (air free) with RED MUD as a catalyst. The reaction effluents (oil and gases) were condensed in water-cooled condenser. The condensate was weighted to determine the total yield. Gas Chromatography-Mass Spectroscopy (GC-MS) analysis was used to characterize the condensed liquid organic compounds. According to the GC-MS results, styrene, benzene and its derivatives, toluene, naphthalene and a small amount of the other hydrocarbon compounds were identified in condensate liquid. Density, specific gravity, API gravity, kinematics and dynamic viscosity, flash point, fire point, cloud point and pour point of condensate were also measuRED. Under optimum reaction condition, the yield of pyrolysis reaction was above 90%. The air free reaction condition showed good catalytic pyrolysis of polystyrene with less than 1% coke formation and above 90% selectivity towards formation of aromatic compounds. The specifications of condensate, i.e. density, API gravity, viscosity and flash point observed showed that the liquid obtained can safely be classed as a kerosene. The specific gravity value was close to the specific gravity value of diesel.

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