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کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: Nanochemistry Research
- نوع مقاله: Journal Article
- کلمات کلیدی: Tetrahydrobenzo[b]pyran,Bipyridine,Dihydropyrano[3,2-c]chromenes,Dihydropyrano[4,3-b]pyrans,Nanosilica supported catalyst
- چکیده:
- چکیده انگلیسی: A novel rice-husk-silica supported n-propyl bipyridinium chloride (RHPrBPCl) has been prepared. Due to the basicity of RHPrBPCl, it was decided to evaluate its catalytic activity in the one-pot preparation of tetrahydrobenzo[b]pyran, dihydropyrano[3,2-c]chromene and dihydropyrano[4,3-b]pyran derivatives. The catalyst was characterized by FT-IR, SEM and TGA analyses. This methodology offers several advantages including easy work-up procedure, high yields of the products, short reaction times, recyclable catalyst and green reaction medium.
- انتشار مقاله: 02-10-1394
- نویسندگان: Ali Reza Kiasat,Sheida Hamid,Seyyed Jafar Saghanezhad
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Nanoanalysis
- نوع مقاله: Journal Article
- کلمات کلیدی: Phase transfer catalyst,Nucleophilic substitution,Porous catalyst,Benzyl halides
- چکیده:
- چکیده انگلیسی: In the present study, application of porous acidic catalyst functionalized with an imidazole
ionic liquid ([SBA-Im]HSO4) as a phase transfer catalyst for the facile preparation of benzyl
thiocyanates and azides in water has been described. The catalyst has been characterized by
Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), transmission
electron microscopy (TEM), thermogravimetric analysis (TGA) and derivative thermogravimetric
analysis (DTG). The polymeric phase transfer catalyst, easily recovered by simple
filtration, shows no appreciable loss of activity when recycled several times.- انتشار مقاله: 04-03-1397
- نویسندگان: Jamal Davarpanah,Ali Reza Kiasat
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Nanoanalysis
- نوع مقاله: Journal Article
- کلمات کلیدی: Sol-gel method,Rice husk,Silica Nanoparticles,Polyvinyl sulfuric acid,Unsymmetrical ethers
- چکیده:
- چکیده انگلیسی: The methodology involves preparing polyvinyl sulfuric acid as a solid acid by simple mixing of
polyvinyl alcohol with chlorosulfonic acid in CH2Cl2 at room temperature. The catalytic ability of
the solid acid was investigated for the facile conversion of benzylic alcohols to the unsymmetrical
ethers with aliphatic alcohols in the presence of the solid acid. Results show that the solid acid is
an appropriate catalytic agent for these condensation reactions. The silica was also extracted from
low-cost rice husk and the amorphous silica gel nanoparticles were prepared with sol- gel method.
The polyvinyl sulfuric acid was supported on nano rice husk silica. Then the catalytic effect of this
system was investigated for synthesis of unsymmetrical ethers which consisted of a combination of
high acidic power for this solid acid and high- surface area of nanoparticles. Results show that totally
catalytic effect of polyvinyl sulfuric acid supported on nano silica is more suitable than polyvinyl
sulfuric acid. The reason for this is in its ability to produce the end products in shorter reaction times
while having high isolated yields.- انتشار مقاله: 26-02-1396
- نویسندگان: Roya Moeinzadeh,Hadi Asareh,Ali Reza Kiasat
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of System Management
- نوع مقاله: Journal Article
- کلمات کلیدی: customer loyalty,knowledge management,Customer Relationship Management
- چکیده:
- چکیده انگلیسی: In present study, effects of knowledge management on the customer relationship management is studied. Study technique is descriptive and survey. To test the study hypotheses firstly a questionnaire with 30 items was designed and applied to 80 managers survivor and directors of various parts of Hormozgan oil company. Then achieved information's were categorized in excel and their statistical properties were studied. Then study architecture model was adapted using smartPLS software to examine the relationship between the variables. In the fitness stage, 4 items were deleted due to lack of suitable relationship with the study variables and then the final model was extracted. Relevance and reliability of the construction and model was examined and after assuring the accuracy and reliability of test tool, study hypotheses were examined. Results of this study indicates that knowledge management with mediatory role of customer loyalty has a significant relationship with customer relationship.
- انتشار مقاله: 17-01-1396
- نویسندگان: Ali Ghasemi-Kia,Mohammad Mohebby
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of the Iranian Chemical Research
- نوع مقاله: Journal Article
- کلمات کلیدی: Solvent-free,Protection,Carbonyl compound,Silica sulfuric acid,2,4-Dinitrophenylhydrazone
- چکیده:
- چکیده انگلیسی: Silica sulfuric acid is employed as solid acid catalyst for the clean and less hazardous
protection of carbonyl compounds as 2,4-dinitrophenylhydrazone under solvent-free conditions.- انتشار مقاله: 15-02-1388
- نویسندگان: Mehdi Fallah-Mehrjardi,Ali Reza Kiasat
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Optoelectronical Nanostructures
- نوع مقاله: Journal Article
- کلمات کلیدی: Graphene,Hydrodynamic Equations,Electrostatic Waves,Dispersion Relation
- چکیده:
- چکیده انگلیسی: In this paper, by using a quantum hydrodynamic plasma model which incorporates the important quantum statistical pressure and electron diffraction force, we present the corrected plasmon dispersion relation for graphene which includes a k quantum term arising from the collective electron density wave interference effects (which is integer and constant and k is wave vector). The longitudinal plasmons are the electrostatic collective excitations of the solid electron gas. We have tried to use the quantum hydrodynamic model for studying of propagation of the electrostatic surface wave in single layer graphene, in the presence of an external and uniform magnetic field. The direction of magnetic field was selected in plane of graphene sheet. It shows the importance of quantum term from the collective electron density wave interference effects. By plotting the dispersion relation derived, it has been found that dispersion relation of surface modes depends significantly on these quantum effects (Bohm’s potential and statistical terms) and it should be taken into account in the case of magnetized or unmagnetized plasma; we have noticed successful description of the quantum hydrodynamic model. The quantum corrected hydrodynamic model can effectively describe the Plasmon dispersion spectrum in degenerate plasmas, since it takes into account the full picture of collective electron-wave interference via the quantum Bohm’s potential. By plotting the normalized dispersion relation, the behavior of two different wave types (lower- and higher- branches) was predicted. It was found that the lower-branch should not be propagated to the specific wave number (cut-off frequency). By drawing of the contour curve of the lower- and higher-branches modes, the areas that modes can be propagated were obtained. So, Quantum hydrodynamic model is an effective way to study the waves in various media.
- انتشار مقاله: 23-06-1395
- نویسندگان: Alireza Abdykian,Zahra Safi
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Applied Dynamic Systems and Control
- نوع مقاله: Journal Article
- کلمات کلیدی: LED,photonic crystal,GaN,Finite-Difference Time Domain (FDTD)
- چکیده:
- چکیده انگلیسی: In this paper, a new structure of Light-Emitting Diodes (LEDs) based on the usage of Gallium Nitride (GaN) semiconductors has been proposed in which, in order to improve the efficiency of the output light, a reflective layer along with two Photonic Crystal (PC) layers have been employed. The applied changes and their optimization illustrated increase in output light efficiency as much as 133% with respect to a typical LED.
- انتشار مقاله: 26-11-1398
- نویسندگان: Ali Kian,Ali Kian,Ali Kian
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Veterinary Medicine
- نوع مقاله: Journal Article
- کلمات کلیدی: Broiler chicken,Glutathione peroxidase,Artichoke extract,lipid stability
- چکیده: زمینه مطالعه: عصاره کنگرفرنگی حاوی ترکیبات آنتی اکسیدان طبیعی میتواند بعنوان یک منبع با پتانسیل خوب آنتی اکسیدانی در نظر گرفته شود. هدف: هدف از انجام این مطالعه ارزیابی توانایی آنتی اکسیدان عصاره کنگر فرنگی بر کیفیت گوشت جوجهها بود. روش کار: 200 جوجه گوشتی نژاد رأس به پنج گروه مساوی تقسیم شدند و به ترتیب 100، 200، 300 و 500 عصاره کنگر فرنگی (94%) در آب آشامیدنی (mg/l) و گروه کنترل آب خالص دریافت کردند. پیش از افزودن عصاره به آب آشامیدنی، فعالیت آنتی رادیکالی عصاره توسط روش 1,1-diphenyl-2-picrylhydrazyl (DPPH) و محتوی فنل آن براساس میزان گالیک اسید اندازهگیری شد. جوجههای گوشتی با عصاره کنگر فرنگی از روز 35-21 دوره رشد درمان شدند و نمونههای گوشت ران برای آنالیز بیوشیمیایی در روز 42 از دوره پرورش تهیه شد. نتایج: فعالیت آنتی رادیکالی عصاره و محتوی فنل به ترتیب 35٪ و/100 g 3/3 عصاره بود. در خصوص آنزیمهای آنتی اکسیدانی مانند گلوتاتیون پراکسیداز (GPx) و کاتالاز (CAT)، استفاده ازmg/l200 عصاره کنگرفرنگی بیشترین خاصیت آنتی اکسیدانی را در مقایسه با گروههای دیگر نشان داد (0.05>p). همچنین، افزودن mg/l200 عصاره کنگرفرنگی به آب آشامیدنی کمترین فعالیت را برای آنزیمهای GPx و CAT در مقایسه با گروه کنترل و mg/l300 صاره نشان داد (0.05>p). تفاوتهای معنیداری بین گروه کنترل و گروههای دریافت کننده عصاره برای شاخصهای عملکردی وزن مانند: میزان افزایش وزن، متوسط افزایش وزن روزانه، درصد افزایش وزن در روزهای 35-21 دوره آزمایش نسبت به کل دوره و وزن نهایی وجود نداشت (0.05<p). نتیجهگیرینهایی: این مطالعه نشان داد که تجویز mg/l200 عصاره کنگرفرنگی در آب آشامیدنی در طول دوره رشد فعالیت آنزیمهای آنتی اکسیدانی گلوتاتیون پراکسیداز (GPx) و کاتالاز (CAT) را در گوشت ران جوجههای گوشتی کاهش داد، که احتمالاً نتیجه کاهش بیان ژن برای این آنزیمها میباشد.
- چکیده انگلیسی: Background: Artichoke extract (AE), containing natural antioxidant compounds, can be considered as a good source of antioxidant potential. OBJECTIVES: The aim of this study was to evaluate antioxidant abilities of AE on broiler meat quality. METHODS: 200 Ross chicken broilers were divided into five equal groups and received 100, 200, 300, and 500 mg/liter of AE in drinking water and pure water in the control group, respectively. Antiradical activity and phenolic content of AE were determined by 1,1-diphenyl-2-picrylhydrazyl (DPPH) method and gallic acid measurement before adding extract into drinking water. The broilers received AE extract form 21-35 day of growing phase and the samples from thigh muscles were taken for biochemical analysis in the 42 day of the growing phase. RESULTS: Antiradical activity of AE was 35% and phenolic content was 3.3 g/100g of dry extract. Regarding antioxidant enzymes, such as glutathione peroxidase (GPx) and catalase (CAT), the AE with dosage of 200 mg/l indicated maximum antioxidant ability compared to the other groups (p<0.05). Supplementation of AE200 mg/l also demonstrated the lowest GPx and CAT activities, compared to the control and AE 300 mg/l groups (p<0.05). Regarding performance weight gain, average daily weight gain, percentage of weight gain in 21 to 35 as well as final weight were similar in control and AE-received groups and AE indicated similar effect for all the treatments. CONCLUSIONS: This study showed that administration of 200 mg/l AE in drinking water during growing phase decreased GPx and CAT activities in chicken meat presumably due to down-regulation of gene expression for antioxidant enzymes.
- انتشار مقاله: 12-08-1394
- نویسندگان: Maryam Mirderikvandi,Ali Kiani,Majid Khaldari,Masoud Alirezaei
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian journal of Learning and Memory
- نوع مقاله: Journal Article
- کلمات کلیدی: Trend,math teachers,Demographic and personality variables,TIMSS studies
- چکیده:
- چکیده انگلیسی: The purpose of this study was to review the changes in the role of demographic and personality variables of mathematics teachers in predicting the mathematical progress of eighth-grade students in Iran and analyzed the trend of these variables in four international studies. For this purpose, we examined the data from 21434 eighth graders and 877 math teachers who had participated in four TIMSS studies (2003, 2007, 2011 & 2015). Among the educational variables influencing the educational development, ten variables including gender, age, history of teaching, the degree, major, teaching hours, job satisfaction, confidence, interaction with other teachers and teaching method were investigated using statistical methods of Pearson correlation coefficient and multiple regression analysis. The findings related to the demographic variables showed that the students ' mathematical performance changes were almost consonant with the changes of age, history of teaching, and teaching hours in both groups of male and female teachers. This coordination was not similar in the major and academic degrees. The results of multivariate regression showed that the students ' mathematical development was explained by the set of demographic and personality variables. Among these variables, teaching history and self - confidence of the teachers played the most important role in explaining the students ' progress, and the variables of the degree of education and gender did not contribute to the explanation of the students ' math’s progress. The findings show the necessity of paying more attention to the history of teaching and examining the reasons why major and teachers ' degree were not that influential in math development is essential.
- انتشار مقاله: 05-09-1397
- نویسندگان: Nahid Honarmand,Alireza Kiamanesh,Abdolazim Karimi
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Otorhinolaryngology
- نوع مقاله: Journal Article
- کلمات کلیدی: treatment,Effect,Estrogen,Traumatic Wounds
- چکیده:
- چکیده انگلیسی: Introduction:
Acute skin wound healing is a complicated process comprising various phases. Recent animal studies have shown that steroid sex hormones such as estrogen maybe helpful in the regulation of several pathophysiologic stages that are involved in wound healing. In this study we examined the effects of topical estrogen in the treatment of traumatic facial wounds.
Materials and Methods:
Patients referred to Luqman Hospital, Tehran with traumatic wounds were enrolled in this case-control study into two groups of equal size. From the second week of the study, topical estrogen (0.625 mg conjugated topical estrogen ointment) was administered in the case group, while the control group received a Eucerin dressing only. The two groups were then compared in terms of wound healing rate on Day 7,14, and 30.
Results:
Thirty patients with mean age of 16.02+36.23 years were compared in the control and estrogen-treated groups. After treatment, no scars or keloids were observed in either group. The wound area in the estrogen group was lower than that in the control group on Day 14 and 30, but the difference was not significant (P>0.05). Healing rates in the control group on Day 14 (7.1+42.3 vs.50.3+4.9 mm2) and Day 30 (1.9+93.5 vs. + 97.3+0.6 mm2) (were lower than those in the estrogen group, but the differences were not significant (P>0.05). Findings show that the required time for wound healing in the estrogen-treated group was lower than that in the control group, but the difference was not significant (P>0.05).
Conclusion:
Based on this study, topical estrogen has no effect on the rate of wound healing or the rate of wound area .- انتشار مقاله: 03-12-1393
- نویسندگان: Seyed Amirhosein Ghazizadeh Hashemi,Behrooz Barati,Hosein Mohammadi,Masumeh Saeidi,Abbas Bahreini,Mohammad Ali Kiani
- مشاهده