Technology of Education Journal
Year:2009 | Volume:3 | Issue:2|Papers Count:8

Panel construction has played an important role in building construction in recent decades. These buildings are different from the conventional frame structures because of lack of usual beam and column elements. It seems that structural engineers have reservations in using these construction systems, due to some ambiguities in the seismic behavior and specially in choosing the proper value for the seismic response modification factor.Study of this factor in panel buildings dealt with in this paper by investigation on three different panel structures with similar plan layouts and different heights. PERFORM-3D software is employed to model the nonlinear behavior of these structures with the capability of finite element analysis by making use of the multilayer fiber section shell elements. Doing so, the response modification factors are calculated and discussed.According to the drawn conclusions, it seems that there exist a considerable difference between the obtained results and the values suggested by the related standards, which implies a need for revision due to apparently excess conservatism.

The main aims of this study were to compare the effectiveness of Polyaluminum Chloride (PACI) and Ferric Chloride, to optimization the coagulation/flocculation process, to investigate the effect of adding bentonite (as a coagulant aid) and to compare the residual Aluminum after adding PACI and Alum. Samples were collected from influent of Jalalieh water treatment plant, Tehran, Iran. In the first phase, the effectiveness of PACI and Ferric Chloride was compared. In this phase, the optimum coagulant dosages were 40 and 35 mg/L for Ferric Chloride and PACI, respectively. In the second phase, with adding 20 mg/L of bentonite, the optimum coagulant dosages were reduced to 25 and 15 mg/L for Ferric Chloride and PACI, respectively. The results of third phase of this study showed that PACI leaves less residual Aluminum than Alum.

This study investigated the relationship between globalization and the necessity for EFL curriculum reform in Iran. It also analyzed challenges and opportunities created for curriculum and syllabus designers in this process. The qualitative analysis of the Perspective of Islamic Republic of Iran in 1404, and Development Plans 4 and 5 was done in order to find out the country's policy toward globalization. The status of EFL program in Iran was described by carrying out two further analyses: (1) a comparative study of Iranian and Middle Eastern examinees’ TOEFL scores from 2002 to 2007, and (2) a review study of problems of teaching and learning English in Iranian high schools. The results of the analyses showed that: (1) Iran has taken an active role in facing globalization by appreciating its Iranian-Islamic values; (2) EFL program in Iran has serious problems, and (3) EFL curriculum reform in Iran is essential and inevitable in the process of globalization.

This paper proposed a new method for face recognition with principal component analysis in the feature extraction phase, and devised a modified version of Mixture of Experts in which each expert is an MLP, instead of linear networks in order to improve the performance of the expert networks, and consequently the whole network performance; Therewith, we use a Momentum term in training the MLP experts, which speeds up the adjustment of weight greatly. We explore three different Mixture of Experts constructing a neural network. Our proposed model, achieved a correct recognition rate on Yale and ORL datasets. Comparisons with other algorithms demonstrate that our method performs better in terms of higher recognition rate, with smaller number of epochs in human face recognition.

The non-dimensional Navier stokes equations in rotational form for the boundary layer flow is solved using direct numerical simulation. The length scale and velocity scale of the base flow the boundary layer thickness and the inviscid velocity outside the layer are used as the length and velocity scales at the inlet boundary of the computational domain are used as two characteristics to define the flow Reynolds number. The governing equations are discritised in the streamwise direction using a sixth order compact finite difference scheme, and in the cross-direction using a mapped compact finite difference scheme. An algebraic mapping is used to map the physical domain into the computational domain .The compact third order of Runge-kutta method is used for the time-advancement purpose. The convective outflow boundary condition is employed to create a non-reflective type boundary condition at the outlet. The simulation resuhs of this flow were compared by Blasius solution that show accuracy program. In this study, also, characteristics of laminar boundary layer flow verification for accuracy program with divided the lengths and velocity by length of plane and uniform velocity of environment respectively. Profiles and contours of velocity and vorticity have planed in flow arrow and self- similar have seen.

Reactive sintering is a kind of combustion synthesis processes for synthesize of new materials. In this research, the mentioned process was used for production of titanium aluminide/alumina composite from starting materials of titanium dioxide and aluminum. According to the obtained results, composite particles including TiO2/Al with a size around 100 nm can be produced. Densification of produced powders via cold isostatic pressing machine following by reaction sintering lead to produce a composite body consisting titanium aluminids and alumina.

Eutectic Silicon phases form as the coarse and acicular shape in Aluminum-Silicon alloys.These phases have detrimental effect on mechanical properties of casting parts. Modification process has been used to change the shape of these phases to fibrous morphology. In this research different level of strontium; in the form of Al-10%Srmaster alloy; have been added to 319 aluminum alloy to investigate their effects on modification. Thermal Analysis has been used as a technique to study the cooling curves and first derivative curves. Effect of strontium on solidification parameters such as nucleation temperature (TN,si), and growth temperature (TG,Si) of eutectic silicon has been determined. (TN,si)and (TG,Si) have been reduced by increasing strontium content. (DTEGAl-Si) can be used as a parameter to control the modification of eutectic silicon. The results of this research indicate that thermal analysis technique can be used as an accurate and quick device of on-line quality control in production lines of aluminum casting industries.