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1 - Zeolite catalyzed alkylation of toluene by alcohol
F. Sheikhoslamy M. Yari K. AhzanVapor-phase methylation of toluene using methanol and its isopropylation with 2-propanol has been investigated ina down flow reactor under atmospheric conditions using N2 carrier over a series of surface modified andunmodified ZSM-5 (Si/Al= 60-170) loaded with H3PO4, di أکثرVapor-phase methylation of toluene using methanol and its isopropylation with 2-propanol has been investigated ina down flow reactor under atmospheric conditions using N2 carrier over a series of surface modified andunmodified ZSM-5 (Si/Al= 60-170) loaded with H3PO4, differing in the external surface treatment of the zeolites.The feed molar ratios of toluene/methanol and toluene/2-propanol were varied over a wide range (8-0.125), andthe optimum feed ratio of toluene/alcohol was less than 0.5 in both cases. Space velocity employed in toluenemethylation reported as WHSV (toluene) = 1.2114, and the space velocity employed in toluene isopropylationreported as WHSV (toluene) = 0.8 III. The methylation reactions were carried out in the temperature range of 623-773 K, and the isopropylation reactions were carried out in the temperature range of 483-583 K. Atmosphericpressures was maintained in all runs. Catalysts containing 0-4.9 wt.% P were prepared using modified andunmodified ZSM-5 zeolites, and their catalytic performance for vapor-phase alkylation of toluene with methanoland 2-propanol were investigated. The optimum phosphorous content for methylation was 2.1 wt.% P which wasgreater than the optimum phosphorous loading for isopropylation (0.7 wt.% P) تفاصيل المقالة -
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2 - Copper Nanoparticles as efficient catalyst for the transesterification of p -ketoesters
A.R. Abbaspour P. MoaveniTransesterification, one of the most effective methods for ester synthesis, is usually conducted under acid or basicconditions. Although quite a few methods have been reported for transesterification, they are not general as far asp-ketoesters are concerned. Some of the أکثرTransesterification, one of the most effective methods for ester synthesis, is usually conducted under acid or basicconditions. Although quite a few methods have been reported for transesterification, they are not general as far asp-ketoesters are concerned. Some of these methods used toxic, expensive reagents and in relatives large amount. Inthis research, transesterification reaction six types P-ketoesters achieved in present of Cu powder and Cunanoparticles as catalyst and P-ketoesters prepared using this method. Copper Nanoparticles is an efficient catalystfor the transesterification of p-ketoesters with several kinds of alcohols, leading to good yields with highselectivity. تفاصيل المقالة -
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3 - بررسی حذف زایلن از آب به وسیله نانو اکسید روی به عنوان جاذب نفت
بهناز صالحی امیرحسام حسنی همایون احمد پناهی سید مهدی برقعیزمینه و هدف : با توجه به اثرا ت نا مطلوب زیست محیطی و خسارات غیر قابل جبران مواد شیمیایی موجود در ترکیبات نفتی نظیر بنزن، تولوئن ، اتیل بنزن و زایلن بر سلامت جانداران، حذف موثر و کارامد این آلاینده ها بیش از پیش مورد توجه قرار گرفته است تا با ابداع روش های نوین کارایی و أکثرزمینه و هدف : با توجه به اثرا ت نا مطلوب زیست محیطی و خسارات غیر قابل جبران مواد شیمیایی موجود در ترکیبات نفتی نظیر بنزن، تولوئن ، اتیل بنزن و زایلن بر سلامت جانداران، حذف موثر و کارامد این آلاینده ها بیش از پیش مورد توجه قرار گرفته است تا با ابداع روش های نوین کارایی و تاثیر فرایند های حذف بهبود بخشیده شود. در این تحقیق استفاده از نانو ذرات روی اصلاح شده با شاخه های آلی در حذف زایلن از محیط های آبی مورد بررسی قرار گرفته است. روش کار: نانوذرات اکسید روی (Zno) توسط روش هم رسوبی شیمیایی تهیه گردید. به منظور افزایش راندمان جذب، در ابتدا اصلاح نانو ذرات صورت گرفت و در مرحله بعد مونومر عامل دار شده تهیه گردید و بر روی بدنه نانو ذرات اصلاح شده پیوند داده شد. عملکرد این جاذب در حذف زایلن به عنوان شاخص آلودگی نفتی مورد مطالعه قرار گرفت و اثر پارامتر های مختلف بر میزان جذب از قبیل pH محیط، زمان تماس و غلظت جاذب بررسی شد. یافته ها: نتایج بدست آمده نشان داد که بیشترین میزان جذب نانو جاذب سنتز شده در pH برابر با 6 و پس از گذشت 25 دقیقه از زمان تماس می باشد. همچنین نتایج نشان داد که با افزایش غلظت نانو جاذب درصد حذف نیز افزایش می یابد. بحث و نتیجه گیری: با توجه به بررسی های انجام شده کارایی بالای استفاده از نانواکسید روی اصلاح شده در حذف زایلن از محیط های آبی تایید گردید و امکان استفاده از آن در حذف آلاینده های نفتی از آب مطرح شد. تفاصيل المقالة -
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4 - Selective Catalytic Oxidation of O-xylene to Phthalic Anhydride over VPO/HZSM-5: An Optimization Study
Ali Monajemi Vahid MahdaviSelective gas-phase oxidation of o-xylene to phthalic anhydride over VPO/HZSM-5 catalysts was investigated. The catalysts with various P/V ratio were facilely synthesized by impregnation method. The prepared catalysts were characterized by several techniques such as SEM أکثرSelective gas-phase oxidation of o-xylene to phthalic anhydride over VPO/HZSM-5 catalysts was investigated. The catalysts with various P/V ratio were facilely synthesized by impregnation method. The prepared catalysts were characterized by several techniques such as SEM, TPD-NH3, H2-TPR, FT-IR, BET and XRD. The effects of P/V ratio (1.6–2.4), reaction temperature (350–450 ◦C), Ox/O2 ratio (0.15–0.60) and gas hourly space velocity (G.H.S.V) of O2/N2 (600–1200 h-1) on yield of PA were studied by Box–Behnken design. The influence of independent factors and their quadratic interactions were examined by means of the Analysis of Variance (ANOVA). Present results indicate that P/V ratio has a different effect on the conversion and selectivity of PA. The catalyst with P/V ratio = 2.0, Ox/O2 ratio = 0.37, G.H.S.V of 770 h-1 and reaction temperature of 370 ◦C produced maximum yield of PA (80.7 %). The analysis revealed that the predicted results agree well with the experimental data (P/V ratio = 2.0, Ox/O2 ratio = 0.38, G.H.S.V of the carrier gas = 900 h-1 and reaction temperature of 400 ◦C with 74.3% yield). تفاصيل المقالة -
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5 - مطالعه فرایند جذب سطحی 4 نیترو زایلن از محلول های آبی بر روی اکسید گرافن
پروین غربانی4نیترو زایلن از جمله ترکیبات خطرناک و سمی می باشد که از پسابهای صنایع تولید کننده انواع حشره کش ها وارد منابع آبی شده و باعث الوده شدن ذخایر آبی و محیط زیست می شود. در این مقاله،از اکسید گرافن برای حذف ترکیب سمی 4 نیترو زایلن از محلول های آبی به روش جذب سطحی استفاده شد. أکثر4نیترو زایلن از جمله ترکیبات خطرناک و سمی می باشد که از پسابهای صنایع تولید کننده انواع حشره کش ها وارد منابع آبی شده و باعث الوده شدن ذخایر آبی و محیط زیست می شود. در این مقاله،از اکسید گرافن برای حذف ترکیب سمی 4 نیترو زایلن از محلول های آبی به روش جذب سطحی استفاده شد. در این راستااثر پارامترهای مختلف از جمله غلظت اولیه 4 نیترو زایلن ، زمان تماس، pH آغازین، دوز جاذب و دما بر روی حذف 4 نیترو زایلن مطالعه شد. نتایج نشان داد که فرایند جذب سطحی در 90 دقیقه به تعادل می‌رسد و مقدار حذف 4 نیترو زایلن با افزایش دوز جاذب و دما افزایش می‌یابد. بیشترین میزان حذف نیز در =7 pH رخ داد. اما افزایش غلظت 4 نیترو زایلن رابطه معکوس با درصد حذف داشته و با افزایش غلظت 4 نیترو زایلن درصد حذف کاهش می یابد. مطابق نتایج 001/0 گرم از اکسید گرافن قادر به حذف 69/95% از 4 نیترو زایلن در غلظت اولیه-1 mg L10000 و در6/6 pH=است.بنابراین اکسید گرافن جاذب پرقدرتی برای حذف ترکیب سمی 4 نیترو زایلن می باشد. تفاصيل المقالة -
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6 - The antinociceptive and anti-inflammatory effects of hydro alcoholic extract of Satureja bachtiarica on mouse
فیروزه سقایی صادق معتمدیBackground & Aim: The use of anti-nociceptive and anti-inflammatory drugs in clinical medicine is necessary and unavoidable. Since the use of synthetic drugs is associated with numerous side effects, the application of complementary therapies such as herbal medicine أکثرBackground & Aim: The use of anti-nociceptive and anti-inflammatory drugs in clinical medicine is necessary and unavoidable. Since the use of synthetic drugs is associated with numerous side effects, the application of complementary therapies such as herbal medicine can accompany with less side effects while having anti-inflammatory and analgesic properties. Satureja bachtiarica contains different active compounds such as Thymol, Para syman, Menton and Carvacrol which may be involved in the control of nociception and/or inflammation. Experimental: 75 male mice (weighing 30 -20 g) were divided to 15 groups. Analgesic and anti-inflammatory effects of hydroalcoholic Satureja bachtiarica extract at doses of 400, 600, 800 mg/kg were evaluated by writhing, formalin and xylene tests. Morphine (10 mg /kg) and dexamethasone (10 mg/kg) were considered as positive controls in analgesic and anti-inflammatory tests, respectively. Results & Discussion: Different doses of hydroalcoholic extract of Satureja bachtiarica significantly reduced pain in comparison to control groups, however, the anti-inflammatory effect of this drug evaluated by xylene test, has not been established which needs further examination through other tests. Industrial / Practical recommendation: According to present results, the analgesic effect of Satureja bachtiarica was comparable to morphine. However, it seems that further research is needed in the future to take advantage of this plant in relieving pain. تفاصيل المقالة -
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7 - Preparation and characterization of template-free mordenite type zeolite and comparison of m-xylene isomerization reaction over mordenite and SAPO-11
Zahra Vosoughi Rahbari Mehrji Khosravan Ali Nemati KharatIn this work, Mordenite zeolite was successfully synthesized with Si/Al ratio of 18 in absence of organic template. The hydrothermal method was applied for synthesis under optimum conditions: 24 h synthesis time, 180°C temperature and 2 days aging time. The obtained أکثرIn this work, Mordenite zeolite was successfully synthesized with Si/Al ratio of 18 in absence of organic template. The hydrothermal method was applied for synthesis under optimum conditions: 24 h synthesis time, 180°C temperature and 2 days aging time. The obtained zeolite was characterized by X-ray powder diffraction (XRD), Brunauer-Emmett-Teller (BET), X-ray fluorescence (XRF), Fourier Transforms infrared Spectroscopy (FT-IR) and Scanning Electron Microscopy (SEM). The prepared sample had total (BET) surface area of 331.63 m2g-1, whereas total pore volume was 0.278 cm3g-1. The catalytic performance of this catalyst was investigated for meta-xylene isomerization reaction in a fixed bed reactor at the 10 bars Pressure, 380°C temperature and 3.35 h-1 Weight hourlyspace velocity (WHSV) of feed. The results compared with a commercial SAPO-11 catalyst (Si/Al = 20) and showed that the mordenite gave better Para/Ortho ratio (63%) and fewer amount of xylene loss (2.11%) compared to SAPO-11. تفاصيل المقالة -
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8 - The Correlation of Blood Xylene Levels and Neurological Disorders among Informal Car Painters
Arie Kurnianto Tri Martiana Nemeskéri Zsolt István Ágoston Soedjajadi KemanA provisional study was conducted to analyze the correlation of xylene exposure in the air at the workplace with levels of xylene in blood and neurological symptoms among informal car painting in Surabaya. This research was designed as an observational study and conduct أکثرA provisional study was conducted to analyze the correlation of xylene exposure in the air at the workplace with levels of xylene in blood and neurological symptoms among informal car painting in Surabaya. This research was designed as an observational study and conducted by the cross-sectional technique involving 51 informal car painters. Neurologic symptoms were meant by the German version of the Q18 form while resolving xylene levels within the blood have measured with ELISA. This study has also observed the characteristics of workers and working activity factors. Significant correlations have been shown based on Pearson correlation analysis, which was the age, working period, and duration of work. Meanwhile, Spearman correlation analysis showed that the habit of using a PPE mask, smoking habits, and xylene levels in the blood were strongly considered to have a significant association with neurological symptoms in workers. Simple linear regression s used to analyze the correlation coefficient (R-square), which was 0.718. In conclusion, blood levels of xylene are related to neurological symptoms in informal car painters. The monitoring of xylene levels in the blood and the regular use of PPE masks demonstrated the relationship between xylene exposure and neurological symptoms. تفاصيل المقالة -
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9 - Evaluation of Air Pollutants Caused by Benzene, Toluene, and Xylene at Kazakhstan Petrochemical Industries Inc. LLP in 2022
Kuanysh Syman Zuhra Muter Saleh Ahmed Hasoon Farah A. Dawood Zinah Salem Awfi Luau Ali Khaleel Bekenova Nazym Omarov Nazarbek Bakytbekovich Aldiyar E. MasalovVolatile organic compounds (VOCs) such as benzene, toluene, and xylene are toxic air pollutants which are released into the atmosphere by various human activities such as gasoline production and use, chemical manufacturing and incineration of certain waste. These pollut أکثرVolatile organic compounds (VOCs) such as benzene, toluene, and xylene are toxic air pollutants which are released into the atmosphere by various human activities such as gasoline production and use, chemical manufacturing and incineration of certain waste. These pollutants are also harmful to the environment, causing harm to plants, aquatic life, and soil quality. Therefore, it is important to implement measures to reduce emissions from these substances. The purpose of this paper is to evaluate the air pollutants caused by benzene, toluene, and xylene at Kazakhstan Petrochemical Industries Inc. LLP in 2021–2022. In order to calculate the sample size for this cross-sectional study, the preliminary evaluation findings from a related study that measured the concentration of hydrocarbons in petrochemical facilities were employed. 281 samples were gathered between the winter and summer of 2022. The national institute for occupational safety and health (NIOSH) methods of 1501 was applied to conduct the sampling and analysis of pollutants. The air was sampled using a charcoal tube sampler that was attached to a pump. The chemicals were then extracted using the solvent carbon disulfide (CS2), and samples were then analyzed using a capillary-equipped gas chromatography-mass spectrometer. The collected data were analyzed by SPSS software version 23.0. The findings demonstrated that benzene concentrations in the sampling areas throughout the winter and summer were higher than the recommended value advised by the American conference of governmental industrial hygienists (ACGIH). تفاصيل المقالة
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