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کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: Progress in Color, Colorants and Coatings
- نوع مقاله: Journal Article
- کلمات کلیدی: Antioxidant Activity,Antibacterial activity,Azo dye,2,4,thiazolidinone,Tautomerism
- چکیده:
- چکیده انگلیسی: In the present study, nine bis-azo dyes based on 5-arylidene-2,4-thiazolidinone were obtained in two steps, using Knoevenagel condensation and azo coupling reactions. The structure of the dyes was confirmed on the basis of spectral data. Analysis of spectroscopic data shows that there is equilibrium between the azo and hydrazone tautomers for all dyes in solutions. Investigation of antioxidant activity of compounds was carried out by 2,2-dipheny l-1-picrylhydrazyl DPPH and ferric reducing antioxidant power FRAP methods. The antibacterial activity towards three Gram negative and two Gram positive bacteria was also investigated. The activity data show that the synthesized dyes 3a-i have promising antibacterial activity, comparable with their precursor 1.
- انتشار مقاله: 11-10-1348
- نویسندگان: A. Mohammadi,H. Ghafoori,M. Rassa,M. Safarnejad
- مشاهده
- جایگاه : پژوهشی
- مجله: Progress in Color, Colorants and Coatings
- نوع مقاله: Journal Article
- کلمات کلیدی: Azo dye,Azo,substituent effect,Absorption spectra,Schiff,Base,azomethine
- چکیده:
- چکیده انگلیسی: The reaction of some carbocyclic and heterocyclic Schiff bases with the synthesized 1-bromo, 4-[4-(4-nitrophenylazo) phenoxy] butane and formation of novel linear azo-azomethine compounds in good to excellent yields were investigated. The compounds were fully characterized by UV-Vis, FT-IR, 1H NMR spectroscopic techniques and elemental analysis. Effects of various solvents on their visible absorption spectra at a concentration of 10-5-10-6 M were estimated. The color of the dyes is discussed with respect to the substituent therein. Introduction of an electron-withdrawing group into the para-position of azomethines produces bathochromic shift of the absorption peak in all solvents. The key features of these reactions are, in turn, their operational simplicity, mild reaction conditions and easily-accessed starting materials.
- انتشار مقاله: 09-09-1390
- نویسندگان: A. Mohammadi,M.R. Yazdanbakhsh,N. Mahmoodi
- مشاهده
- جایگاه : پژوهشی
- مجله: SCIENTIA IRANICA
- نوع مقاله: Journal Article
- کلمات کلیدی: Factor analysis,Cluster analysis,Case Study,Safety attitude,Vehicle type choice,Subjective Variables,Fuel economy level,Vehicle emission
- چکیده:
- چکیده انگلیسی: In recent years, researchers have paid specific attention to safety, air pollution, and energy consumption, which are all affected by the vehicle type. The primary objective of this study is to achieve a thorough understanding of the relationships between transportation attitudes, safety attitudes, personality, as well as lifestyle and vehicle type for the first time in Iran, as a developing country. For this purpose, an interview questionnaire was designed, and 740 participants were interviewed in Tehran. Vehicle types are categorized into seven groups: mini, compact, medium, heavy, SUV, pickup, and motorcycle. In the first stage, factor analysis was used to identify the latent variables regarding transportation attitudes, safety attitudes, personality, and lifestyle. In the second step, by using these latent variables, individuals are classified, and a two-level clustering is formed. The correlation analysis performed in the third step shows a significant relationship between each category of people and the type of car. Likewise, the analyses carried out in this study reveal the significant relations between the vehicle type (classified based on fuel economy level, production country, vehicle emission, and vintage) and the attitudes of its owner. This information is beneficial to both vehicle manufacturers and transportation planners.
- انتشار مقاله: 13-09-1397
- نویسندگان: A. Mohammadi,M. Kermanshah
- مشاهده
- جایگاه : پژوهشی
- مجله: AUT Journal of Mechanical Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: Homotopy Perturbation Method,variational iteration method,Nonlinear Vibration,Buckled functionally graded nanobeam
- چکیده:
- چکیده انگلیسی: The present study aims at investigating nonlinear free vibration of thermally buckled functionally graded nanobeam. The nonlocal nonlinear Euler-Bernoulli beam theory as well as linear eigenmodes of a functionally graded nanobeam vibrating around the first buckling configuration are employed to derive a system of ordinary differential equations via the Galerkin method. Semi-analytical solutions are obtained based on both the homotopy perturbation method and the variational iteration method. Results show that the difference between nonlinear and linear frequencies increases with a rise in the maximum lateral initial deflection, small scale parameter value, and index of the power law. Investigating the effect of the ratio of length to thickness on the variance between the nonlinear and linear frequencies shows that the aspect ratio makes no difference on the classical ratio of nonlinear to linear frequencies although the difference between the nonlocal nonlinear and linear frequencies decreases with a rise in the aspect ratio. In contrast to the ratio of the first nonlinear frequency to the first linear one which will decrease if compressive axial load increases, the values of the compressive axial load which are beyond the load bearing capacity of the functionally graded nanobeam do not affect the ratio of the second nonlinear to linear frequencies.
- انتشار مقاله: 25-07-1396
- نویسندگان: S. Ziaee,S. A. Mohammadi
- مشاهده
- جایگاه : پژوهشی
- مجله: AUT Journal of Mechanical Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: Distance,Thermal load,Refrigerator,Thermo-acoustic,Plate stack
- چکیده:
- چکیده انگلیسی: This article aims to investigate the effects of various parameters on the thermal load. The governing equations include continuity and Navier-Stokes equations for the flow field and the energy equation for the temperature distribution in transient mode. Numerical simulation of the thermoacoustic refrigerator by taking the non-zero thickness of the plate stack into account, that is a conjugate heat transfer problem, in a form of 2D has been performed in FLUENT software. Real simulation of thermoacoustic refrigerators needs a consideration of both heat exchangers, whereas in most simulations one or both heat exchangers have been neglected. Results are influenced by the steady state. Input dynamic pressure should be adjusted according to the temperature of the heat exchanger. The results demonstrate the effect of the distance of the plates on the average thermal load suggesting that the distance between the plates should be four times of the thickness of the plates so that the device works properly. By increasing the distance of the plates thermal load decreases. This is mainly because of pressure amplitude reduction induced by an increase in the distance between the plates.
- انتشار مقاله: 21-03-1395
- نویسندگان: A. Mohammadi,S. M. A. Alavi
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Structural Engineering and Geotechnics
- نوع مقاله: Journal Article
- کلمات کلیدی: Shear wave velocity,maximum shear modulus,Seismic Piezocone (SCPTu),Resonant Column,Cyclic Triaxial Test
- چکیده:
- چکیده انگلیسی: Seismic piezocone device (SCPTu) together with Resonant Column and Cyclic Triaxial test apparatus are employed to measure small strain shear modulus (G0) of carbonate sandy and clayey soils of southern coasts of Iran. A large area of southern regions of Iran is formed from clay, silt and sand. In this study, maximum shear modulus that is derived from both field (by seismic piezocone) and laboratory (by Resonant Column and Cyclic Triaxial) tests on soil samples from the southern region, indicated a meaningful effect of sample disturbance. Results show that in laboratory tests, loose samples tend to become denser and therefore exhibit greater stiffness whereas dense samples tend to become looser, showing a reduction in stiffness. According to the results of the present study, there are narrow limits of soils shear moduli for which the laboratory tests and the field measurements yield approximately the same amounts. This limit of shear moduli is about 30-50(MPa) for clay deposits and 70-100 (MPa) for sandy deposits. Since the shear moduli of soils in small strains can also be computed from the shear wave velocity, also correlations based on parameters derived from SCPTu test for shear wave velocity determination of sandy and clayey soils of the studied area are presented. This study shows that shear wave velocity can be related to both corrected tip resistance and total normal stress. Regarding the shear moduli and the damping ratio, due to the disturbances of the stiff deposits in the sampling process and great deviations of laboratory results from field results, the laboratory measurements of these parameters out of the above limits are not recommended.
- انتشار مقاله: 12-10-1392
- نویسندگان: Seyed Majdedin Mir Mohammad Hosseini,A.A. Hajimohammadi
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Ornamental Plants
- نوع مقاله: Journal Article
- کلمات کلیدی: perlite,Chlorophyll,postharvest life,Growth medium
- چکیده: To study the effect of different concentrations of potassium in the
nutrient solution and water stress on the quality and quantity yield of Lilium LA cv.Termoli, a pot experiment was conducted based on completely randomized design in sand and perlite medium (50:50) in three levels of potassium (Kfree, 6 mM K and and 12 mM K in Hoagland solution) with three replications. In the present study, the growth indices, post-harvest life of flower and potassium and chlorophyll contents were measured in shoots. The results showed that the plant dry/fresh weight and vegetative height was highest in 6 mM potassium treatments. Lily postharvest life at 6 mM K was increased 5.7 days relative to k-free conditions. The chlorophyll a, b and total content in nutrient solution without K were lower than in nutrient solution with 6 and 12 mM potassium.- چکیده انگلیسی: To study the effect of different concentrations of potassium in the
nutrient solution and water stress on the quality and quantity yield of Lilium LA cv.Termoli, a pot experiment was conducted based on completely randomized design in sand and perlite medium (50:50) in three levels of potassium (Kfree, 6 mM K and and 12 mM K in Hoagland solution) with three replications. In the present study, the growth indices, post-harvest life of flower and potassium and chlorophyll contents were measured in shoots. The results showed that the plant dry/fresh weight and vegetative height was highest in 6 mM potassium treatments. Lily postharvest life at 6 mM K was increased 5.7 days relative to k-free conditions. The chlorophyll a, b and total content in nutrient solution without K were lower than in nutrient solution with 6 and 12 mM potassium.- انتشار مقاله: 21-05-1394
- نویسندگان: A. Mohammadi Torkashvand,T. Toofighi Alikhani
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Ornamental Plants
- نوع مقاله: Journal Article
- کلمات کلیدی: Calcium,Plants Nutrition,Soilless,Tresor Lily
- چکیده: The Asiatic hybrid lily, a bulbous ornamental plant, has a special position in the horticulture as cut flower. To overcome some problems in nutrition of bulb flowers, the use of hydroponic system and nutrient solution is important in the cultivation of these flowers. The Asiatic Hybrid Lilium bulbs “Tresor” cultivar, used for the current research were planted under 3 different calcium levels including 2, 4 and 6 mM as randomised completely designed with five replications. Comparing the mean values of the data showed that 6 mM calcium produced maximum height of the plant, stem diameter, procreative height, number of buds, flower diameter and longevity of cut flowers
- چکیده انگلیسی: The Asiatic hybrid lily, a bulbous ornamental plant, has a special position in the horticulture as cut flower. To overcome some problems in nutrition of bulb flowers, the use of hydroponic system and nutrient solution is important in the cultivation of these flowers. The Asiatic Hybrid Lilium bulbs “Tresor” cultivar, used for the current research were planted under 3 different calcium levels including 2, 4 and 6 mM as randomised completely designed with five replications. Comparing the mean values of the data showed that 6 mM calcium produced maximum height of the plant, stem diameter, procreative height, number of buds, flower diameter and longevity of cut flowers
- انتشار مقاله: 19-05-1394
- نویسندگان: N. Seyedi,A. Mohammadi Torkashvand,M.S. Allahyari
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Ornamental Plants
- نوع مقاله: Journal Article
- کلمات کلیدی: Vermicompost,Marigold,Peat,Growth medium
- چکیده: In order to investigation of vermicompost effect on growth and yield of marigold in pot medium, an experiment was done by a randomized completely block design in three raplications. Treatmnets were included control (30% v/v of soil plus 70% v/v of sand) and three levels of vermicompost (20, 40, 60 % v/v of vermicompost+30% v/v of sand and soil) that applied in three lit. pots. Marigold seeds (Tagetes erecta cv. Tiashan) were planted in media. The shoots were cut and it was measured the bush heigh, the lateral branches, size and flower weight, dry weight of shoot, and the concertretion of nutrient elements. The results showed that added vermicompost to the growth media tend to improve the growth and yield of marigold than in the control. The Vermicompost (60%) had the highest weight, size and dry weight of shoot, but the maximum bush height was obtained by 20% vermicompost. The most lateral branches was belong to 40% vermicompost treatment. The results showed that the plants which cultivated on 60% vermicompost medium had the most amount of nitrogen, phosphorus and calcium. The most amount of potassium was ralated to 40% vermicompost treatment.
- چکیده انگلیسی: In order to investigation of vermicompost effect on growth and yield of marigold in pot medium, an experiment was done by a randomized completely block design in three raplications. Treatmnets were included control (30% v/v of soil plus 70% v/v of sand) and three levels of vermicompost (20, 40, 60 % v/v of vermicompost+30% v/v of sand and soil) that applied in three lit. pots. Marigold seeds (Tagetes erecta cv. Tiashan) were planted in media. The shoots were cut and it was measured the bush heigh, the lateral branches, size and flower weight, dry weight of shoot, and the concertretion of nutrient elements. The results showed that added vermicompost to the growth media tend to improve the growth and yield of marigold than in the control. The Vermicompost (60%) had the highest weight, size and dry weight of shoot, but the maximum bush height was obtained by 20% vermicompost. The most lateral branches was belong to 40% vermicompost treatment. The results showed that the plants which cultivated on 60% vermicompost medium had the most amount of nitrogen, phosphorus and calcium. The most amount of potassium was ralated to 40% vermicompost treatment.
- انتشار مقاله: 25-05-1394
- نویسندگان: F. Shadanpour,A. Mohammadi Torkashvand,K. Hashemi Majd
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Simulation and Analysis of Novel Technologies in Mechanical Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: Abrasive particles,Magnet,Ferromagnetic particles,Surface finishing,helical ball screw
- چکیده:
- چکیده انگلیسی: Surface finishing is one of the most significant steps in industries which are engaged with surface quality. Finishing by magnetic field is a new method of surface finishing. In this process, machining is executed in mechanical way and semi-homogeneous abrasive slurry performs finishing of surfaces. Needed force to grind surfaces is made by magnetic field. Therefor this method is considered as an advanced machining method. One of application of advanced machining methods is working in situation which conventional methods are not applicable. Nowadays helical and spiral parts have an important position in industry. This result in more attention about manufacturing and finishing of parts. This mechanism is used to finish helical ball screw in CNC machine using magnetic field created by Nd-Fe-B permanent magnet. In executed experiments four parameters which affected on surface quality were investigated. These parameters included feed rate, particles size and amount of ferromagnetic particles. The effect of most parameters was positive and caused to improve surface quality, but generally each parameter had an optimum amount in which by reaching this amount, reducing in efficiency and surface quality was observed. Also, some parameters such as cutting speed had lower effect. The initial specimen had surface roughness of 1.017 µm and the best resultant surface quality was 0.325 µm.
- انتشار مقاله: 16-08-1394
- نویسندگان: A. Mohammadi,A.H. Azizi
- مشاهده