Islamic Azad University at Maybod

www.maybodiau.ac.ir
Yazd, Iran

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Mohseni Meybodi S.,Islamic Azad University at Maybod | Hosseini S.A.,Iranian Materials and Energy Research Center | Rezaee M.,Amirkabir University of Technology | Sadrnezhaad S.K.,Sharif University of Technology | Mohammadyani D.,Iranian Materials and Energy Research Center
Ultrasonics Sonochemistry | Year: 2012

A sonochemistry-based synthesis method was used to produce nanocrystalline nickel oxide powder with ∼20 nm average crystallite diameter from Ni(OH)2 precursor. Ultrasound waves were applied to the primary solution to intensify the Ni(OH)2 precipitation. Dried precipitates were calcined at 320 °C to form nanocrystalline NiO particles. The morphology of the produced powder was characterized by transmission electron microscopy. Using sonochemical waves resulted in lowering of the size of the nickel oxide crystallites. FT-IR spectroscopy and X-ray diffraction revealed high purity well-crystallized structure of the synthesized powder. Photoluminescence spectroscopy confirmed production of a wide band-gap structure. © 2011 Elsevier B.V. All rights reserved.


Mirjalili F.,Islamic Azad University at Maybod | Chuah L.,University Putra Malaysia | Mohamad H.,Universiti Sains Malaysia
Journal of Ceramic Processing Research | Year: 2011

The present paper tends to explore the effect of stirring time on the synthesis of nano α-Al 2O 3 particles. In this study, alumina nanoparticles were synthesized through an alkoxide route implementing sol-gel method in which aqueous solutions of aluminum isopropoxide and 0.5 M aluminum nitrate nanohydrate were used to prepare an alumina sol. Sodium dodecylbenzen sulfonate was used as the surfactant stabilizing agent. The prepared solution was stirred for different times (24, 36, 48 and 60 hours) at 60 °C. The samples were, then, characterized by Brunauer-Emmet-Teller method, X-ray diffraction, thermogravimetry analysis, differential scanning calorimetry, Fourier transform infrared spectrometry, scanning electron microscopy and transmission electron microscopy. The introduction of different stirring times affected the particle size and shape and the degree of aggregation. By increasing the stirring time (starting from 24 to 48 hours), the particle size decreased, but there was a harder agglomeration for the samples with 60 hours stirring time. The finest particle size (20-30 nm) was obtained at 48 hours stirring time.


Ashrafzadeh A.,Islamic Azad University at Yazd | Sayadian S.,Islamic Azad University at Maybod
Computers in Human Behavior | Year: 2015

Abstract This study attempted to investigate the concerns and perceptions of Iranian EFL university instructors of technology integration in their classes. A sequential mixed method design was used in this study including Hall, George, & Rutherford's (1977) Stages of Concern Questionnaire (SoCQ) and Rogers' (1995) Diffusion of Innovation (DOI) questionnaire followed by a semi-structured interview. There were 91 university instructors asked to participate in the survey, out of whom nine were interviewed and finally, a focus group of five participants was conducted. The findings of the study revealed that the university instructors showed more Self concerns (Informational and Personal stages). "Relative advantage and compatibility" attributes of Diffusion of Innovation model were proved to be significantly different among instructors of different fields of study while the participants' gender revealed a significant difference in their "trialability" attribute. Moreover, based on the quantitative data of the study, lack of administrative facilities, instructors' technology literacy toward technology integration and accessibility of technology for all the students were reported to be the source of the instructors' concerns. © 2015 Elsevier Ltd. All rights reserved.


Yazdi H.A.M.,Islamic Azad University at Maybod | Sulong N.H.R.,University of Malaya
Journal of Constructional Steel Research | Year: 2011

In this paper, a method based on genetic algorithm is proposed for determining the optimum connection point with the highest lateral buckling load in the Off-Centre bracing system. This type of bracing system is mostly used in seismic areas and it allows architects to have more openings in the panel area. In this system, the non-straight diagonal member introduces eccentricity to the system and is connected to the corner of the frame by a third member. In designing this system, designers often use "trial and error" to locate the connection point of the brace elements considering various parameters affecting the design such as opening and frame dimensions, cross sectional areas of brace elements and the location of the brace element connection. Hence, finding the best connection point with maximum lateral buckling load can be problematic by the conventional methods. To demonstrate the effectiveness of the proposed GA method, examples with different frame specifications were presented. © 2011 Elsevier Ltd. All rights reserved.


Mirjalili F.,Islamic Azad University at Maybod
Bulletin of Materials Science | Year: 2014

Nano-α-Al2O3 particles were synthesized by a sol-gel method using aqueous solutions of aluminum isopropoxide and 0·5Maluminum nitrate. Sodium dodecylbenzenesulfonate (SDBS) was used as surfactant stabilizing agents. The solution was stirred for 48 h at 60 °C. The microstructural observation showed that surfactant with 48 h stirring time nanoscale α-Al2O3 powder was produced at 1200 °C in the range of 20-30 nm in the presence of SDBS as a surfactant with 48 h stirring time. Temperature reduction of α-Al2O3 formation has been achieved by introducing fluoride in the alumina precursor. The effects of ZnF2 additive and milling on the phase transformation as well as micrograph of the prepared α-Al2O3 particles were investigated. The samples were characterized by different techniques such as X-ray diffraction, thermogravimetry analysis, differential scanning calorimetry, Fourier transform infrared spectra, scanning electron microscopy and transmission electron microscopy. Results indicated that using zinc fluoride (ZnF2) additive accompanied by milling led to retardation of the transformation temperature and modification of the alumina particle shape. The finest size for nonagglomerated nano-plate-like α-Al2O3 particles (15-20 nm) was achieved at 950 °C. © Indian Academy of Sciences.


Mirjalili F.,Islamic Azad University at Maybod
Journal of Composite Materials | Year: 2014

Polypropylene nanocomposites containing 1-5?wt% of nano α-alumina particles are prepared using a Hake internal mixer. Mixing of nano α-alumina particles is performed at 170°C and 50 rotational per minute is set for the rotor speed. To improve the dispersion of the nanoparticles, sodium dodecylbenzenesulfonate is used. X-ray analyses reveal that the basal spacing of polypropylene/nano α-Al2O3 composites compared to the pure polypropylene spreads out. The peak intensity for polypropylene / nano α-Al2O3 composites is stronger and narrower with larger amounts of the nano α-Al2O3 filler, in comparison with the virgin polypropylene. According to differential scanning calorimetry, the crystallinity of the nanocomposites is increased with increases in nano α-Al2O3 filler loading. The storage and loss modulus of the nanocomposites are found to be higher than that of pure polypropylene, because nanofiller increases the stiffness of the nanocomposites. The tensile strength and tensile modulus of the polypropylene nanocomposites are slightly improved up to 4% of nano α-Al2O3 particle filler adding. The addition of filler content higher than that amount leads to the reduction of these properties. The formation of filler agglomeration site within the matrix body affects the decreasing of properties. Transmission electron microscopy observations confirm these results. © 2013 The Author(s).


Kargar M.J.,Islamic Azad University at Maybod
International Journal of Advancements in Computing Technology | Year: 2011

The Web is becoming the most important scholarly communication tool and it makes more and more scientific information accessible. In recent years, university Web rankings have become in importance around the world. The central hypothesis of the ranking is that the university's web presence reflects its global performance, the quality of its departments and services, the impact of its outputs and its international prestige. One of the most important dimensions in university Website ranking is visibility factor and usability. The dimension includes qualitative and quantitative criteria. The current paper attempts to priorities usability criteria for university Website then evaluate selected universities' websites as a case study by some of the qualitative sub-criteria. The results show there are strong correlation between usability factors and university Website ranking.


Mirjalili F.,Islamic Azad University at Maybod
Composite Interfaces | Year: 2014

In this study, nano α-alumina particles were synthesized by a sol-gel method using aqueous solutions of aluminum isopropoxide and 0.5 M aluminum nitrate. 1/3-benzene disoulfonic acid disodium salt (SDBS) and fluoride were used as surfactant stabilizing agent and additive, respectively. Results indicated that the finest size for nonagglomerated nanoalumina particles (15-20 nm) was achieved at 950 °C. The next part was about preparing PP nanocomposite containing nano α-Al2O3 particles. Mechanical tests, such as tensile, flexural, and impact tests showed that mechanical properties of the composite were enhanced by addition of nano α-Al2O3 particles and dispersant to the polymer. However, higher concentration of nano α-Al2O3 loading resulted in reduction of those mechanical properties, which could be due to agglomeration of nano α-Al2O3 particles. Transmission and scanning electron microscopic observations of the nanocomposites also showed that fracture surface became more roughened by increasing the content of filler loading from 1 to 4% wt. © 2014 Taylor & Francis.


Kargar M.J.,Islamic Azad University at Maybod
Proceedings of the International Conference on Uncertainty Reasoning and Knowledge Engineering, URKE 2011 | Year: 2011

The vast amount of information on the World Wide Web is created and published by many different types of providers. Unlike books and journals, most of this information is not subject to editing or peer review by experts. This lack of quality control and the explosion of web sites make the task of finding quality information on the web especially critical. Meanwhile new facilities for producing web pages such as Blogs make this issue more significant because Blogs have simple content management tools enabling non-experts to build easily updatable web diaries or online journals. On the other hand despite a decade of active research in information quality (IQ) there is no framework for measuring information quality on the Blogs yet. This paper attempts to evaluate and prioritize selected IQ criteria in the Weblog. The present study adapted the AHP methodology to the measurement of the selected IQ criteria priorities. The results shows there are significant difference for priorities in Blog context in compare of common Websites. © 2011 IEEE.


Yazdi H.M.,Islamic Azad University at Maybod
International Journal of Steel Structures | Year: 2016

Uncertainty and vagueness of required data, boundary conditions, incomprehensive modeling of objective functions and their level of importance are among numerous problems with which designers are dealing in optimizing structures. In this regard, the importance levels of the objective functions such as material weight and system stiffness, which are presented by linguistic statements, are very important to improve the optimization results. In this paper, a novel two-grade evaluation method is proposed to model the pre-set condition statements. Then, for optimization of structure with multiple functions, a multi - objective genetic algorithm is integrated with the fuzzy logic inference system. To validate the proposed method, an Off Center Braced frame system (OCB) is modeled. Then, a MATLAB program is developed for the fuzzy multi-objective calculations. The results demonstrated good accuracy of the proposed method in structural optimization by using designer linguistic information.Hence, by this method designer’s experiences can be applied as linguistic statements in designing procedures to catch the optimum results which is more precise than other methods using only Genetic Algorithms. © 2016, Korean Society of Steel Construction and Springer-Verlag Berlin Heidelberg.

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