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1 - تبیین مولفه های مؤثر بر دلبستگی به مکان از منظر گروه نوجوان در شهر تهران
زهرا خدائی مجتبی رفیعیان هاشم داداش پور علی اکبر تقواییاین تحقیق به بررسی و سنجش مولفه های اثر گذار بر دلبستگی به مکان و تبیین معناداری یا عدم معناداری آنها در محله های منتخبی از شهر تهران می پردازد. روش این مطالعه از نوع توصیفی- تحلیلی بوده است و داده ها با توزیع 475پرسشنامه با نوجوانان در رده سنی (12- 16) ساله که به روش أکثراین تحقیق به بررسی و سنجش مولفه های اثر گذار بر دلبستگی به مکان و تبیین معناداری یا عدم معناداری آنها در محله های منتخبی از شهر تهران می پردازد. روش این مطالعه از نوع توصیفی- تحلیلی بوده است و داده ها با توزیع 475پرسشنامه با نوجوانان در رده سنی (12- 16) ساله که به روش طبقه ای سیستماتیک انتخاب شده اند، انجام شد. در این مقاله، شاخص دلبستگی به مکان به تفکیک در چهار محله مورد بررسی قرار گرفت. بدین منظور از آزمون پارامتریک F و نیز آزمون Tukey (تفاوت معناداری) استفاده شد تا بتوان محله های منتخب را خوشه بندی و به این سئوال پاسخ داد که کدام محله ها، شبیه به هم و کدام محله ها با هم متفاوت هستند. در انتها، محله ها از نظر شاخص دلبستگی به مکان مقایسه شده و مولفه های دلبستگی به محله با استفاده از ضریب لامبدا مورد تبیین قرار گرفتند. تفاصيل المقالة -
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2 - Reactivity and aromaticity of hexasiline derivatives Si6XH5 (X = H, F, Cl, Br, COOH, NO2, NH2, CH3 and tBu)
Mehdi NabatiDuring recent years, the silicon organic-inorganic compounds play the key role in medicinal chemistry and pharmaceutical industry. This is because of their similar chemical properties with carbon compounds. The second reason is related to their easy transfer from the ce أکثرDuring recent years, the silicon organic-inorganic compounds play the key role in medicinal chemistry and pharmaceutical industry. This is because of their similar chemical properties with carbon compounds. The second reason is related to their easy transfer from the cell membranes. So, molecular simulation and study the properties of novel organosilicon compounds can be more important. From this sight of view, we designed and investigated silicon analogs of benzene ring before. Here, the various derivatives of hexasiline molecule will be discussed in the following. Our investigations are based on the density functional theory (DFT) computations. The present research work was focused on investigation of the structural and spectral properties and reactivity of hexasiline using B3LYP/cc-pVDZ level of theory. The Fukui indices (local reactivity) showed that the electrophilic attacks happen on the Si4 atoms of the molecules. On the other hand, the molecules containing electron-donating and electron-withdrawing substituents prefer do nucleophilic reactions on their Si4 and Si3 positions, respectively. تفاصيل المقالة -
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3 - Theoretical structural analysis of 3-CHLORO-4-FLUORO-ANILINE.
Muhammad Aziz Sohail Nadeem Muhammad AnwarThis study was designed to compute the spectroscopic properties of aniline family, and educates the 3chloro-4-fluoro-aniline, which have unique pharmaceutical important. The structural and spectroscopic properties were investigated using a quantum calculation. The densi أکثرThis study was designed to compute the spectroscopic properties of aniline family, and educates the 3chloro-4-fluoro-aniline, which have unique pharmaceutical important. The structural and spectroscopic properties were investigated using a quantum calculation. The density functional theory approach at B3LYP/631G(d) data set is apply. IR and UV-Visible spectrophotometric estimated through GAMESS, Raman spectrogram was obtain through Gaussian and NMR C1 and C13 spectrums were also predicted through computational methods. After obtaining the results, they were tabulated. The results of current computational analysis is in sense useful to predict even a complex aniline precursor and advantage of the current computational strategy is beneficial for other aniline molecules containing chlorine and fluorine atoms. The success of this Density function theoretical results opens a pathway to apply a correct algorithm and a force field for the assignments of aniline family spectroscopy property. تفاصيل المقالة -
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4 - The effect of Environmental exposure to some chemical solvents on DPPC as important component of lung surfactant: an ab initio study
M. Monajjemi S. Afsharnezhad J. Yousefi M.R. Jaafari B. Honarparvar M. Mirsadraiee T. Abdolahi S. Ghadri A. Nikosade S.A. BadieeyanOne of the main components of lung alveoli is surfactant. DPPC (Dipalmitolphosphatidylcholine) is thepredominant lipid component in lung surfactant that is responsible for lowering surface tension in alveoli in thisarticle. We used a very approximate model with computat أکثرOne of the main components of lung alveoli is surfactant. DPPC (Dipalmitolphosphatidylcholine) is thepredominant lipid component in lung surfactant that is responsible for lowering surface tension in alveoli in thisarticle. We used a very approximate model with computational method of Ab initio to describe the interactionsbetween DPPC as important component of lung surfactant and some chemical solvents such as Benzene,Toluene, Heptane, Acetone and Ethanol which cause Lung injuries that contribute to respiratory distress such asARDS. The effect of these solvents on the conformation and disordering DPPC head group has beeninvestigated with calculation at the Hatree-Fock level using the 6-31G basis set with Onsager continuumsalvation, GAIO and frequency models. In concern with conformational energy, Water could be the mostsuitable solvent for DPPC. It could be in polar medium DPPC conformer becomes additionally stabilized byintermolecular ionic and hydrogen bond interactions with polar neighboring molecules. On the other hand, thisstudy shows that Ethanol has the most effect on conformation and lipid disorder DPPC head group of lungsurfactant in our model. تفاصيل المقالة -
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5 - A Theoretical Study on Interaction between Nitrobenzene and Carbon Nanotube (A DFT approach)
N. Malmir B. Naderi F. NaderiThe Density Functional Theory (DFT) and the Natural Bond Orbital (NBO) calculations basedmethod B3LYP/6-31G* were carried out to study the interaction of carbon nanotube (8,0) withnitrobenzene in two situations perpendicular and parallel. Formation energies of compounds أکثرThe Density Functional Theory (DFT) and the Natural Bond Orbital (NBO) calculations basedmethod B3LYP/6-31G* were carried out to study the interaction of carbon nanotube (8,0) withnitrobenzene in two situations perpendicular and parallel. Formation energies of compounds,charges, the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular'orbital (LUMO) and the HOMO-LUMO band gap were calculated. The parallel direction is morestable than the perpendicular direction. The lower HOMO-LUMO gaps confirm this stability. تفاصيل المقالة -
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6 - Impact of Lewis acid catalyst on the regioselectivity and kinetics of 1,3-dipolar cycloaddition reaction of azidobenzene with acrolein: a theoretical study using DFT
F. Shams S. R. Emamian E. ZahediIn the present work, impact of Lewis acid (LA) catalysts BF3, BCl3, and BBr3 on the kinetics andregioselectivity of 1,3-dipolar cycloaddition (1,3-DC) reaction between azidobenzene and acroleinwas theoretically studied using B3LYP/6-31G* level. Our results indicate whil أکثرIn the present work, impact of Lewis acid (LA) catalysts BF3, BCl3, and BBr3 on the kinetics andregioselectivity of 1,3-dipolar cycloaddition (1,3-DC) reaction between azidobenzene and acroleinwas theoretically studied using B3LYP/6-31G* level. Our results indicate while the uncatalyzed 1,3-DC reaction under investigation takes place via a non-polar, non-regioselective, and lowasynchronous process, the LA catalyzed 1,3-DC reaction takes place via a polar, regioselective, andhigh asynchronous process. In addition, the barrier height of the studied 1,3-DC reaction isconsiderably reduced in the presence of LA catalysts, and the catalytic activity of LAs in order toincrease the electrophilicity character of acrolein and, consequently, to reduce barrier height ofreaction, is increased with the increase of halogen atom size; BBr3> BCl3> BF3. Regioselectivity inthese LA catalyzed 1, 3-DC reactions appears to be controlled by steric repulsion effects between theLA catalyst and the azide phenyl substituent instead of the electronic effects. تفاصيل المقالة -
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7 - Synthesis of 1, 3-diaryl Substituted Iodobenzene Derivatives
Farnaz Abolfazli- Khosroshahi Akbar SaeidniyaThe synthesis and characterization a new derivatives of 2'-iodo-meta terphenyl from the reaction ofexcess aryl-Grignard and 2, 6- dichloroiodobenzene with quenching of m-terphenyl-2'-magnesiumbromide by iodine is reported. Via the reactions three carbon-carbon bonds are أکثرThe synthesis and characterization a new derivatives of 2'-iodo-meta terphenyl from the reaction ofexcess aryl-Grignard and 2, 6- dichloroiodobenzene with quenching of m-terphenyl-2'-magnesiumbromide by iodine is reported. Via the reactions three carbon-carbon bonds are constructed and mterphenylsare obtained in good yields. تفاصيل المقالة -
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8 - Application of topological and physicochemical descriptors: QSTR analysis of the toxicity of benzene derivatives
H. Hosseini F. Shafiei -
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9 - تولید کربن فعال میان حفره از مخروط درخت کاج ایرانی (Pinus eldarica) با استفاده از فعّال‌سازی شیمیایی برای جذب سدیم دودسیل بنزن سولفونات از محلول آبی
سهیل ولی زاده حبیب‌الله یونسی نادر بهرامی فرزمینه و هدف: امروزه آلودگی‌های ناشی از فاضلاب‌های حاوی سورفاکتانت‌ها یکی از عوامل عمده و شایع آلودگی‌های محیط زیستی به‌شمار می‌روند. سدیم دودسیل بنزن سولفونات (SDBS)، از مهم ترین و عمده ترین انواع سورفاکتانت ها محسوب می شود. هدف از این مطالعه سنتز کربن فعال میان‌حفره از أکثرزمینه و هدف: امروزه آلودگی‌های ناشی از فاضلاب‌های حاوی سورفاکتانت‌ها یکی از عوامل عمده و شایع آلودگی‌های محیط زیستی به‌شمار می‌روند. سدیم دودسیل بنزن سولفونات (SDBS)، از مهم ترین و عمده ترین انواع سورفاکتانت ها محسوب می شود. هدف از این مطالعه سنتز کربن فعال میان‌حفره از مخروط درخت کاج ایرانی (Pinus eldarica) با استفاده از فعّال سازی شیمیایی به‌منظور حذف سورفاکتانت سدیم دودسیل بنزن سولفونات (SDBS) از محلول آبی در سیستم ناپیوسته می باشد. روش بررسی: برای سنتز کربن فعال از فعال‌سازهای اسید فسفریک، پتاسیم کربنات و پتاسیم هیدروکسید با نسبت‌های اشباع‌سازی متفاوت استفاده گردید. فرایند کربنیزاسیون در کوره سرامیکی تحت جریان گاز نیتروژن با دبی گاز ml/min 100 در دمای°C 750، میزان حرارتی °C/min8 و به مدت 3 ساعت انجام شد. بیشترین سطح ویژه در نمونه فعال‌سازی شده با اسید فسفریک با نسبت اشباع 2:1 معادل m2/g1580 به‌دست آمد. در سیستم ناپیوسته کارایی نمونه‌های کربن فعال تولید شده برای جذب SDBS از محلول آبی مورد ارزیابی قرار گرفت. یافته‌ها: نتایج نشان داد که کربن فعال تولیدشده با استفاده از فعال‌ساز پتاسیم کربنات با درصد اشباع 1: 75/0 دارای بیشترین ظرفیت جذب معادل mg/g 56/97 بوده است. برای بررسی سینتیک واکنش از مدل‌های شبه درجه اول، شبه درجه دوم و نفوذ درون‌ذره‌ای استفاده شد که نتایج بیانگر این بود که مدل شبه درجه دوم با 982/0 R2>از برازش بهتری با داده‌های تجربی برخوردار است. آزمایش واجذب با استفاده از ترکیبات مختلف انجام گرفت، اسیدسولفوریک و اتانول به ترتیب با 67/65 و 03/40 درصد بیشترین میزان واجذب را نشان دادند. تفاصيل المقالة -
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10 - شناسایی ترکیبات فرار و بررسی اثرات ضداکسیدان، ضد میکروب و ضد سرطانی گیاه Tribulu longipetalus Viv.
علی اکبر ایمانیهدف: هدف پژوهش حاضر شناسایی ترکیبات فرّار و بررسی اثرات ضداکسیدان، ضد میکروب و ضد سرطانی گیاه خارخسک بیابانی بود.مواد و روش‌ها: در این پژوهش گیاه خارخسک بیابانی که گیاهی علفی یک‌ساله، دارای انشعاب‌های متعدد، خوابیده روی سطح زمین، دارای ساقه‌هایی با کرک‌های موئی نرم است، أکثرهدف: هدف پژوهش حاضر شناسایی ترکیبات فرّار و بررسی اثرات ضداکسیدان، ضد میکروب و ضد سرطانی گیاه خارخسک بیابانی بود.مواد و روش‌ها: در این پژوهش گیاه خارخسک بیابانی که گیاهی علفی یک‌ساله، دارای انشعاب‌های متعدد، خوابیده روی سطح زمین، دارای ساقه‌هایی با کرک‌های موئی نرم است، مورد بررسی قرار گرفته است. محدوده انتشار جغرافیائی این گیاه در گستره ماسه‌زارهای ریگ بلند بیابان‌های آران و بیدگل می‌باشد. خواص زیستی ازجمله سنجش فعالیت مهار رادیکال آزاد، بررسی میزان کل ترکیبات فنلی، میزان خواص ضد میکروبی و همچنین میزان خواص سمیت سلولی آن بررسی شد. از آنجا که عصاره تام گیاه در تست سمّیت سلولی میگوی آب شور میزان مهار بالایی از خود نشان داد (نزدیک به 70 میکروگرم بر لیتر)، به منظور دستیابی به اجزای مؤثر، استخراج با حلال به کمک قیف دکانتور در دستور کار قرار گرفت. سه جزء به دست آمده هگزانی، اتیل استاتی و آبی به طور جداگانه بررسی شد. همچنین با استفاده از ستون کروماتوگرافی پلی استایرن دی ونیل بنزن، به جداسازی جزء مؤثر که توانایی مهار بالاتری داشته باشد، اقدام گردید. از میان اجزای موثر جز اتیل استاتی دارای قدرت مهار نسبتاً بالایی بود که به کمک دستگاه Hplc شناسای اجزای مؤثر آن صورت گرفت.یافته‌ها: مقایسه قدرت ضد میکروبی گیاه خارخاسک بیابانی با آنتی‌بیوتیک‌ها، نشان داد که این گیاه دارای خاصیت آنتی میکروبیال خوبی است. همچنین با در نظر گرفتن اینکه LC50 برابر با 70 میکروگرم بر میلی‌لیتر تعیین شد. این مقدار نشان‌دهنده قدرت سمّیت سلولی خوب از گیاه خارخاسک بیابانی است. تفاصيل المقالة -
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11 - Natural Bond Orbital (NBO) Population Analysis of Iridabenzene (C5H5Ir)(PH3)3
R. Ghiasi E. Ebrahimi MokaramThe molecular structure of iridabenzene (C5 H5 Ir)(PH3 )3 was calculated by the B3LYP density functional model using LANL2DZ basis set for Ir and 6-31G(d) for other atoms. The results from natural bond orbital (NBO) analysis have provided new insights into Ir–liga أکثرThe molecular structure of iridabenzene (C5 H5 Ir)(PH3 )3 was calculated by the B3LYP density functional model using LANL2DZ basis set for Ir and 6-31G(d) for other atoms. The results from natural bond orbital (NBO) analysis have provided new insights into Ir–ligand bonding, the hybridization of atoms and the electronic structure of the title molecule. The NBO calculations show that σ(Ir-C2) bonds are formed from an sd1.18 hybrid on iridium atom π(Ir–C3) bond is formed from an sd5.21. Also, these calculations determined that strongest electron donation occurs from a lone pair orbital on the phosphorous atoms, LP(1)P to the antibonding acceptor σ*(Ir–C) orbitals. تفاصيل المقالة -
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12 - P-Dodecylbenzenesulfonic acid (DBSA), a Brønsted acidSurfactant Catalyst for Synthesis of α, ά-bis(substituted benzylidene)cycloalkanones with Electron-Withdrawing Substituent in Aqueous Media
Enayatollah Sheikhhosseini Sayed Ali Ahmadi Saleh SadeghiAn array of aromatic aldehydes with electron withdrawing groupunderwent crossed-Aldol condensation with cycloalkanone in the presence of catalytic amounts of DBSA under aqueous media to afford the corresponding α, ά-bis(substituted-benzylidene) cycloalkanones in g أکثرAn array of aromatic aldehydes with electron withdrawing groupunderwent crossed-Aldol condensation with cycloalkanone in the presence of catalytic amounts of DBSA under aqueous media to afford the corresponding α, ά-bis(substituted-benzylidene) cycloalkanones in good yields. The electronic effects on aromatic aldehydes could be observed. The present method is operationally simple and use of water as the reaction medium makes the process environmentally benign. تفاصيل المقالة -
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13 - New and Simple Strategy for Dechlorination of Nitrochlorobenzene over Ni/La-Al2O3 Nanocatalyst
Ebrahim Babaei Nader RostameizadehIn this study simple catalytic test experiment was performed in a flask of rotary evaporator for dechlorination of nitrochlorobenzene (NCB) over two samples of Ni/LaAl2 O3 nanocatalysts (C1 and C2). In the reaction, Ni acts as a catalyst to collect hydrogen gas in aqueo أکثرIn this study simple catalytic test experiment was performed in a flask of rotary evaporator for dechlorination of nitrochlorobenzene (NCB) over two samples of Ni/LaAl2 O3 nanocatalysts (C1 and C2). In the reaction, Ni acts as a catalyst to collect hydrogen gas in aqueous solution and dissociate it to produce active hydrogen atoms for replacing the chlorine. The catalysts were characterized by scanning electron microscope (SEM), X-ray fluorescence (XRF), X-ray diffraction (XRD), BET specific surface area, and particle size analysis (PSA) techniques. The Ni/La-Al2 O3 catalyst prepared by aluminium nitrate exhibits greater specific surface area and higher dechlorination efficiency compared to sample prepared through aluminium triisopropoxide precursor. تفاصيل المقالة -
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14 - سنتز کارآمد بنزو[a]پیرانو[۳,۲-c]فنازین در شرایط بدون حلال با استفاده از کاتالیزگر بر پایه مایع یونی بوتیل-3- متیل ایمیدازولیوم هگزافلوئوروفسفات
حسین نعیمی مهسا خراسانیدر این پژوهش، تراکم 2-هیدروکسی نفتالن-۴،۱- دی ٱن، مالونونیتریل، آلدهیدهای آروماتیک و اورتو فنیلن دی آمین برای سنتز موثر بنزو[a]پیرانو[۳,۲-c]فنازین در شرایط بدون حلال استفاده شد. این واکنش در شرایط سبز و بدون حلال و در حضور مایع یونی بوتیل-3- متیل ایمیدازولیوم هگزافلوئور أکثردر این پژوهش، تراکم 2-هیدروکسی نفتالن-۴،۱- دی ٱن، مالونونیتریل، آلدهیدهای آروماتیک و اورتو فنیلن دی آمین برای سنتز موثر بنزو[a]پیرانو[۳,۲-c]فنازین در شرایط بدون حلال استفاده شد. این واکنش در شرایط سبز و بدون حلال و در حضور مایع یونی بوتیل-3- متیل ایمیدازولیوم هگزافلوئوروفسفات به عنوان یک کاتالیزگر بازی انجام شد. برای جداسازی آسان محصول ها از روش تبلور مجدد استفاده شد. محصول ها با بازده خوب تا عالی در مدت زمان ۱۵ تا ۲۵ دقیقه بدست آمدند. همه محصول ها با تکنیک تعیین نقطه ذوب، FT-IR و 1H NMR شناسایی شدند. تفاصيل المقالة -
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15 - 1,4-bis(triphenyl phosphonium)butane peroxodisulfate: conversion of alkyl benzenes to carbonyl compounds
Rashid Badri Maryam Adlu1,4-bis(triphenyl phosphonium)butane peroxodisulfate(BTPPBPDS) were synthesized by treating 1,4-bis(triphenyl phosphonium)butane dibromide and potassium peroxydisulfate in aqueous solution.This was used mild and efficient reagent for oxidation of alkyl benzenes to their أکثر1,4-bis(triphenyl phosphonium)butane peroxodisulfate(BTPPBPDS) were synthesized by treating 1,4-bis(triphenyl phosphonium)butane dibromide and potassium peroxydisulfate in aqueous solution.This was used mild and efficient reagent for oxidation of alkyl benzenes to their corresponding carbonyl compounds in very good to high yields. تفاصيل المقالة -
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16 - Melamine-terephthalaldehyde supported Copper tetrabenzenecarboxylic acid As An Efficient Heterogeneous Acidic Catalyst (COF-MOF) for the One-pot Preparation of 1,8-Dioxooctahydroxanthenes
Zahra Baymaninezhad Haman Tavakkoli Seyyed Jafar Saghanezhad Elham TahanpesarIn this research article, we report the preparation of from melamine-terephthalaldehyde supported Copper-1,2,4,5-tetrabenzenecarboxylic acid (COF-MOF) as a porous acidic catalyst for the one-pot preparation of 1,8-Dioxooctahydroxanthenes. As a new methodology, this stra أکثرIn this research article, we report the preparation of from melamine-terephthalaldehyde supported Copper-1,2,4,5-tetrabenzenecarboxylic acid (COF-MOF) as a porous acidic catalyst for the one-pot preparation of 1,8-Dioxooctahydroxanthenes. As a new methodology, this strategy offers several advantages including green reaction conditions, high yield of the products, short reaction time, facile work-up, and recyclability of the catalyst. تفاصيل المقالة -
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17 - Electrodeposition of anionic, cationic and nonionic surfactants and gold nanoparticles onto glassy carbon electrode for catechol detection
Soheila Kashanian Maryam Nazari Rezvan MohammadiThree surfactants were selected to modify glassy carbon electrode including sodium dodecylbenzenesulfonate, Tween 80 and cetyltrimethylammonium bromide. The obtained nano-Au/surfactant/GCEs were characterized with scanning electron microscopy and electrochemical techniq أکثرThree surfactants were selected to modify glassy carbon electrode including sodium dodecylbenzenesulfonate, Tween 80 and cetyltrimethylammonium bromide. The obtained nano-Au/surfactant/GCEs were characterized with scanning electron microscopy and electrochemical techniques. Electrochemical behavior of catechol at the nano-Au/surfactant/GCE was thoroughly investigated for modified electrodes. Compared to the unmodified electrode, the peak current obviously increased and the oxidation and reduction peaks potential shifted to the negative and positive potential area, respectively, meaning the peak potential separation is reduced. These changes indicated that the composite nanoparticles possess good electrocatalytic performance on the electrochemical reaction of catechol. The experimental results revealed that the nanoparticle modified electrodes have good performances for catechol sensing, which including convenient fabrication, low detection limits and wide linear ranges. These merits of this sensing system provide high potential to apply in environmental monitoring. In addition, kinetic parameters of catechol redox reaction were determined and the number of electrons was obtained two for the three modified electrodes. تفاصيل المقالة -
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18 - An investigation of carbon nanotubes on shear stress, thermal conductivity and the viscosity of Nanofluids
Aref ShokriThe Nanofluid includes suspensions containing nanoparticles, which are dispersed in the base fluid homogeneously. In this study, nanoparticles called multi-walled carbon nanotubes (MWCNT) were dispersed in a pure water-based fluid. The shape, size, and arrangement of ca أکثرThe Nanofluid includes suspensions containing nanoparticles, which are dispersed in the base fluid homogeneously. In this study, nanoparticles called multi-walled carbon nanotubes (MWCNT) were dispersed in a pure water-based fluid. The shape, size, and arrangement of carbon nanotubes were displayed by the transmittance electron microscope (TEM) and scanning electron microscope (SEM) techniques. The thermal conductivity and viscosity of the resulting nanofluid were measured experimentally. The carbon nanotubes within the nanofluid were stabilized using Sodium dodecyl benzene sulphate. The effect of carbon nanotubes on shear stress, thermal conductivity and viscosity of fluids has investigated. The results showed that at 308K the thermal conductivity was increased from 0.6 to 0.94 w/m.ºC with an increase in the volumetric concentration of MWCNTs from 0 to 0.015%. And the thermal conductivity was increased from 0.74 to 0.94 w/m.ºC with increase in temperature from 298 to 308K. The shear stress was increased from 10.8 to 11.9 N/m2 at 298K by increase in the volumetric concentration of MWCNTs from 0 to 0.015% and it was reduced from 11.9 to 9.2 N/m2 with enhance in temperature from 298 to 308K, respectively. تفاصيل المقالة -
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19 - A Soft and Efficient Approach for Removal of Template from Mesoporous Silica using Benzene Sulfonamide
Mohammad Teymouri Abdolraouf Samadi-Maybodi Amir VahidIn this contribution, an effective and soft method for removal of template from nanochannels of mesoporous silica (MCM-41) is proposed. This method is based on chemically-modified solvent extraction which enhanced by means of an auxiliary organic compound, i.e. benzene أکثرIn this contribution, an effective and soft method for removal of template from nanochannels of mesoporous silica (MCM-41) is proposed. This method is based on chemically-modified solvent extraction which enhanced by means of an auxiliary organic compound, i.e. benzene sulfonamide. Template removal was performed in soft condition, i.e. in the presence of diluted sulfuric acid and at ambient temperature. Presence of benzene sulfonamide extremely improves efficiency of template removal process. The template-extracted mesoporous silica was characterized using powder X-ray diffraction, nitrogen adsorption, transmission electron microscopy, thermogravimetry, elemental analysis and FT-IR spectrometry. Results of XRD, nitrogen adsorption, and TEM displayed that well-ordered hexagonal array of mesopores remained intact after extraction. The obtained results from thermogravimetry, elemental analysis and FT-IR spectrometry indicate that at least up to 94 wt % of template was removed in short time. تفاصيل المقالة -
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20 - Electrodeposition of anionic, cationic and nonionic surfactants and gold nanoparticles onto glassy carbon electrode for catechol detection
Maryam Nazari Soheila Kashanian R. MohammadiThree surfactants were selected to modify glassy carbon electrode including sodiumdodecylbenzenesulfonate, Tween 80 and cetyltrimethylammonium bromide. The obtained nano-Au/surfactant/GCEs were characterized with scanning electron microscopy and electrochemicaltechnique أکثرThree surfactants were selected to modify glassy carbon electrode including sodiumdodecylbenzenesulfonate, Tween 80 and cetyltrimethylammonium bromide. The obtained nano-Au/surfactant/GCEs were characterized with scanning electron microscopy and electrochemicaltechniques. Electrochemical behavior of catechol at the nano-Au/surfactant/GCE was thoroughlyinvestigated for modified electrodes. Compared to the unmodified electrode, the peak currentobviously increased and the oxidation and reduction peaks potential shifted to the negative andpositive potential area, respectively, meaning the peak potential separation is reduced. Thesechanges indicated that the composite nanoparticles possess good electrocatalytic performance onthe electrochemical reaction of catechol. The experimental results revealed that the nanoparticlemodified electrodes have good performances for catechol sensing, which including convenientfabrication, low detection limits and wide linear ranges. These merits of this sensing system providehigh potential to apply in environmental monitoring. In addition, kinetic parameters of catecholredox reaction were determined and the number of electrons was obtained two for the threemodified electrodes. تفاصيل المقالة -
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21 - An investigation of carbon nanotubes on shear stress, thermal conductivity and the viscosity of Nanofluids
Aref ShokriThe Nanofluid includes suspensions containing nanoparticles, which are dispersedin the base fluid homogeneously. In this study, nanoparticles called multi-walledcarbon nanotubes (MWCNT) were dispersed in a pure water-based fluid. The shape,size, and arrangement of carbo أکثرThe Nanofluid includes suspensions containing nanoparticles, which are dispersedin the base fluid homogeneously. In this study, nanoparticles called multi-walledcarbon nanotubes (MWCNT) were dispersed in a pure water-based fluid. The shape,size, and arrangement of carbon nanotubes were displayed by the transmittanceelectron microscope (TEM) and scanning electron microscope (SEM) techniques.The thermal conductivity and viscosity of the resulting nanofluid were measuredexperimentally. The carbon nanotubes within the nanofluid were stabilized usingSodium dodecyl benzene sulphate. The effect of carbon nanotubes on shearstress, thermal conductivity and viscosity of fluids has investigated. The resultsshowed that at 308K the thermal conductivity was increased from 0.6 to 0.94w/m.ºC with an increase in the volumetric concentration of MWCNTs from 0 to0.015%. And the thermal conductivity was increased from 0.74 to 0.94 w/m.ºCwith increase in temperature from 298 to 308K. The shear stress was increasedfrom 10.8 to 11.9 N/m2 at 298K by increase in the volumetric concentrationof MWCNTs from 0 to 0.015% and it was reduced from 11.9 to 9.2 N/m2 withenhance in temperature from 298 to 308K, respectively. تفاصيل المقالة -
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22 - An efficient synthesis of 4-aryl-7-benzylidene-hexahydro-2H-cyclopenta[d] pyrimidin-2-ones/thiones catalyzed by p-dodecylbenzenesulfonic acid
Krishnamoorthy Aswin Majid Ghashang Sheik MansoorA new and efficient method has been developed for the synthesis of 4-aryl-7-benzylidene-1,3,4,5,6,7-hexahydro-2H-cyclopenta[d]pyrimidin-2-ones through Biginelli-like reaction of cyclopentanone, with urea/thiourea and aromatic aldehyde employing p-dodecylbenzenesulfonic أکثرA new and efficient method has been developed for the synthesis of 4-aryl-7-benzylidene-1,3,4,5,6,7-hexahydro-2H-cyclopenta[d]pyrimidin-2-ones through Biginelli-like reaction of cyclopentanone, with urea/thiourea and aromatic aldehyde employing p-dodecylbenzenesulfonic acid (DBSA) as a recyclable catalyst under solvent-free condition. The recovered catalyst was recycled for further runs. The product formation takes place via a cross-aldol condensation of benzaldehyde with cyclopentanone in the presence of DBSA to produce benzylidene intermediate and subsequent Michael addition. The present approach offers the advantages of short reaction time, mild reaction conditions, high yields and convenient operation. All the products were obtained in good to excellent yields and the structures of the synthesized compounds were established by advanced spectroscopic data. تفاصيل المقالة -
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23 - Synthesis of arylidinebarbituric acid derivatives catalyzed by dodecylbenzenesulfonic acid (DBSA) in aqueous media
Hadis Hosseini Enayatollah Sheikhhosseini Dadkhoda GhazanfariA series of arylidine barbituric acid derivatives was synthesized by Knoevenagel condensation reaction of aromatic aldehydes with barbituric acid or thiobarbituric acid using dodecylbenzenesulfonic acid as a Brønsted acid-surfactant catalyst in aqueous media. Reg أکثرA series of arylidine barbituric acid derivatives was synthesized by Knoevenagel condensation reaction of aromatic aldehydes with barbituric acid or thiobarbituric acid using dodecylbenzenesulfonic acid as a Brønsted acid-surfactant catalyst in aqueous media. Regardless of the nature of the substitution (electron-donating and -withdrawing), all the reactions were completed within 15-65 min in water at reflux condition. In these reactions, there was no need for the column purification of the products. The present methodology offers several advantages such as excellent yields, simple procedure and work-up steps, short reaction times, as well as inexpensive and non-toxic catalyst. Use of water as the reaction medium makes the process environmentally benign. تفاصيل المقالة -
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24 - A new method for synthesis of tetrahydrobenzo[b]pyrans and dihydropyrano[c]chromenes using p-dodecylbenzenesulfonic acid as catalyst in water
Enayatollah Sheikhhosseini Dadkhoda Ghazanfari Vida Nezamabadip-Dodecylbenzenesulfonic acid (DBSA) was used as a catalyst for a simple and efficient one-pot synthesis of aryl substititued tetrahydrobenzo[b]pyrans and dihydropyrano[c]chromens via initial Knoevenagel, subsequent Micheal and final heterocyclization reactions of aryl أکثرp-Dodecylbenzenesulfonic acid (DBSA) was used as a catalyst for a simple and efficient one-pot synthesis of aryl substititued tetrahydrobenzo[b]pyrans and dihydropyrano[c]chromens via initial Knoevenagel, subsequent Micheal and final heterocyclization reactions of aryl aldehyde, malononitrile and 4-hydroxycoumarin/dimedone in moderate to excellent yields. The present method was operationally simple and use of water as the reaction medium made the process environmentally benign. تفاصيل المقالة -
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25 - 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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26 - Sources and Seasonal Variance of Ambient Volatile Organic Compounds in the Oil-Based Chemical Industry from 2020 to 2021: A Case Study of Iraq
Amir Fadhil Al-Tu'ma Enas Abdulgader Hassan Ali Taha Ibrahim Mourad Mohammed Zahraa Muhammed Mahdi Ali Abdul Hassan RasuolThe measurement and analysis of pollutants is undoubtedly the first step in controlling them because, without complete knowledge of the quality and quantity of pollutants, it will not be possible to compare them with the permitted limits and ultimately control them. Thi أکثرThe measurement and analysis of pollutants is undoubtedly the first step in controlling them because, without complete knowledge of the quality and quantity of pollutants, it will not be possible to compare them with the permitted limits and ultimately control them. This descriptive-analytical study focused on the oil refineries and chemical industries. Approximately 279 air samples from 18 complexes in an industrial area were collected for this study in the winter of 2020 and 334 samples in the summer of 2021. In this study, 14 volatile organic compounds (VOCs) were examined, measured, and sampled using procedures recommended by the National Institute for Occupational Safety & Health (NIOSH). Finally, GC/FID and GC/MS devices were used to analyze the samples. SPSS version 22.0 was used to analyze the results. In this study, it was determined that the mean of the majority of the compounds in all of the complexes was higher in the summer than in the winter (p<0.05). Additionally, according to the findings, in both the winter and summer seasons, the average ratio of benzene to BTX, BTEX, and all VOCs showed the highest percentage (67.2%) and the average ratio of xylene concentration to these three variables showed the lowest percentage (3.15-7.35%). The findings of this study indicate that the multiplicity of pollution sources and the accumulation of numerous complexes in this area have increased the amount of pollution spread throughout the region's air. As a result, it is advised to use engineering solutions to reduce the amount of pollution. تفاصيل المقالة -
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27 - Investigation Benzene emission from Gas Stations in Tehran’s 22 Districts and its Modeling in Regions with the Highest Emission Levels
maryam chehrehei Seyed Alireza Mirzahosseini Nabiollah Mansouri Mohammad Hassan Behzadi Youssef RashidiVolatile organic compounds including benzene that are produced in industrial activities, especially those emitted from gas stations, can have undesirable effects on the environment and human health. TANKS 4.09 d software was used to calculate benzene emissions from gaso أکثرVolatile organic compounds including benzene that are produced in industrial activities, especially those emitted from gas stations, can have undesirable effects on the environment and human health. TANKS 4.09 d software was used to calculate benzene emissions from gasoline storage tanks in gas stations throughout the 22 Districts in Tehran. Benzene emissions 1.5 m above the ground was modeled for a 12-month statistical period (2018) using AERMOD. Based on the results of emissions, the maps of benzene dispersion and comparison with the number of loading, storage capacity and numbers of storage tanks and active nozzles, In this study, it was identified that benzene emissions have increased due to lack of proportionality between gasoline storage capacity and demand for it and the concentration of gas stations at specific sites without observance of the suitable distance between them. The highest concentration of benzene emissions was recorded in Districts 4,2,15 and 1 (0.143, 0.128, 0.121, 0.118 gr/s respectively) and the lowest in Districts 17 and 14 (0.008, 0.03 gr/s respectively).In heavy traffic Districts, the number of loading and hence benzene emissions have increased due to the high demand for gasoline, the disproportionality between storage capacity and consumer demand for gasoline, and the small number of gas stations. In light traffic Districts, benzene emissions have increased because of the low demand for gasoline, the lack of proportionality between storage capacity and demand for gasoline, and the large number of gas stations that leads to gasoline storage in excess of the demand for it. تفاصيل المقالة
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