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On the Study of Magneto-Hydrodynamic Non-Newtonian Fluid Flow throughout Curvilinear Channel with Corrugated Walls  [PDF]
Seyed Ali Madani Tonekaboni, Hamid Reza Gharahi, Mohammad Hossein Motevaselian, Seyed Fouad Karimian, Sara Jahromi
Open Journal of Modelling and Simulation (OJMSi) , 2014, DOI: 10.4236/ojmsi.2014.24014
Abstract: This article aims to numerically investigate the flow pattern for Newtonian and power law non-Newtonian fluid in a semi-half circular channel with corrugated walls under the influence of a magnetic field. The results indicate that, presence of a magnetic field affects the flow field in several aspects, especially in the vortex creation and dissipation. In addition, the analysis is carried out for different Reynolds numbers to ascertain the influence of magnetic field on each flow regime. Eventually, the analysis is carried out for a range of power indices including pseudo plastic (shear-thinning) to dilatants (shear-thickening) fluids. The results show that by increasing the power-index, the vortices begin to form and grow gradually so that in the shear-thickening fluid an extra vortex is formed and created nearby the corrugated part of the channel.
Radioactive Anomalies in 1:50000 Dehbakri Sheet, South of Kerman Province, Iran  [PDF]
Hamid Reza Jafari, Abdollah Yazdi
Open Journal of Geology (OJG) , 2014, DOI: 10.4236/ojg.2014.48031
Abstract:

Using airborne radiometric geophysical data, one can easily investigate a wide region in a short time and with little cost to finally find areas that are rich in radioactive elements. In this research, the uranium exploration data were first organized, filtered and classified and then the frequency distribution tables and histograms were drawn. After drawing the histograms, the statistical parameters for radioactive elements were calculated. The separation of anomaly populations was done on the basis of distribution around mean value, that is, the resulting mean, mean + 1SD, mean + 2SD, and mean + 3SD were assumed to equal to background, threshold value, the possible anomaly and the probable anomaly, respectively. In the end, representative maps of anomalies and separation of anomaly populations from the background were presented based on classical statistical calculations.

3D Analysis and Investigation of Traffic Noise Impact from Hemmat Highway Located in Tehran on Buildings and Surrounding Areas  [PDF]
Hamid Reza Ranjbar, Ali Reza Gharagozlou, Ali Reza Vafaei Nejad
Journal of Geographic Information System (JGIS) , 2012, DOI: 10.4236/jgis.2012.44037
Abstract: This study analyzes and investigates the impact of traffic noise on high rise buildings and surrounding areas by the side of Hemmat Highway that links west of Tehran to the east. In this study, a 3D traffic noise simulation model is applied on a GIS system. Visualized noise levels are formulated by the proposed model for noise mapping on all surfaces of the buildings and surrounding ground in a 3D platform. The investigation shows that there is a high traffic noise impact on the foreground and front facades of buildings, rendering these areas unsuitable for residential purposes. The ground area by the sides of buildings and the building side panels receive a lower noise impact. Most of these areas are still not acceptable for residential and even commercial use, only the back yards and back panels, have the lowest traffic noise impact. It also shows that the building height is not an effective factor for reducing motorway noise on the upper part of the building. Finally, construction cantilever barriers with a height of seven meters, close to the outer edge of the highway was presented as an effective way to reduce noise within the allowable range of noise pollution for commercial and residential purposes.
Maximum Ratio Combining Precoding for Multi-Antenna Relay Systems  [PDF]
Hamid Reza Bahrami, Tho Le-Ngoc
Communications and Network (CN) , 2010, DOI: 10.4236/cn.2010.22016
Abstract: This paper addresses the design of practical communication strategies for multi-antenna amplify-and-forward and decode-and-forward relay systems. We show that simple linear techniques at the source and destination in conjunction with maximum ratio combining can provide an optimal transmission strategy in terms of received SNR without imposing a huge computational load over the relay node(s). Besides, the structures of precoding matrices are very similar at the source and relay nodes, which reduces the complexity as all nodes can play the role of source and relay nodes without changing their transmission structure. Numerical results show that the proposed transmission and reception techniques can improve the received SNR, and hence enhance the ergodic capacity.
Video Frame’s Background Modeling: Reviewing the Techniques  [PDF]
Hamid Hassanpour, Mehdi Sedighi, Ali Reza Manashty
Journal of Signal and Information Processing (JSIP) , 2011, DOI: 10.4236/jsip.2011.22010
Abstract: Background modeling is a technique for extracting moving objects in video frames. This technique can be used in ma-chine vision applications, such as video frame compression and monitoring. To model the background in video frames, initially, a model of scene background is constructed, then the current frame is subtracted from the background. Even-tually, the difference determines the moving objects. This paper evaluates a number of existing background modeling techniques in term of accuracy, speed and memory requirement.
Mechanical Characteristics of Superaustenitic Stainless Steel Type 30Cr25Ni32Mo3 at Elevated Temperatures  [PDF]
Gholam Reza Ebrahimi, Hamid Keshmiri, Hadi Arabshahi
Materials Sciences and Applications (MSA) , 2010, DOI: 10.4236/msa.2010.16047
Abstract: In making tubes of corrosion resistant and hardly deformed steels and alloys, the pilger rolling method is used for hot rolling of final thick-walled tubes or mother tubes of large diameters (above 300 mm) and small quantities of other size tubes when no other, more efficient tube rolling or extrusion equipment is available. To clarify individual parameters of the production process and make choice of the deformation-and-temperature parameters, mechanical properties of the alloy type 30Cr25Ni32Mo3 Superaustenitic Stainless Steel at various temperatures were studied. The tests have been performed using samples taken from the forged 400 mm diameter billet to determine strength and plastic properties of the billet metal at various temperatures and its macro- and microstructure. The test results will be used in the choice of optimum conditions of preheating of the billets and hot rolling of tubes. On the whole, it should be stated that as-forged alloy 30Cr25Ni32Mo3 features a favorable combination of strength and plastic properties in the hot-working temperature range of 1075-1200?C.
User Selection and Precoding Schemes Based on Partial Channel Information for Broadcast MIMO Systems  [PDF]
Hamid Reza Bahrami, Tho Le-Ngoc
Int'l J. of Communications, Network and System Sciences (IJCNS) , 2010, DOI: 10.4236/ijcns.2010.34043
Abstract: Due to the large number of users and the time-varying characteristics of wireless channels, it is very tough to inform the transmitter of full channel information in real multi-user MIMO broadcast systems. On the other hand, the capacity of multi-user systems greatly depends on the knowledge of the channel at the transmitter while this is not always the case in single-user MIMO systems. In this paper, we investigate combined user selection and zero-forcing precoding schemes that use partial channel information, i.e., very low amount of channel information at the base station. We show that while greatly reducing the complexity and channel knowledge feedback load, the proposed schemes preserve the optimality of zero-forcing scheme in term of achievable ergodic sum capacity in limit of large number of active users.
The Evaluation of Industrial Cement Production Plant on the Environmental Pollution Using Magnetic Susceptibility Technique  [PDF]
Hadi Ghorbani, Ali Aghababaei, Hamid Reza Mirkarimi
Agricultural Sciences (AS) , 2013, DOI: 10.4236/as.2013.412108
Abstract:

Different pollutants in soil, water, and other parts of the environment are so important in portraying environmental pollution, and could come from different source of pollutions including industrial activities. Entering metals into the soil by human activities is an important process in the geochemical cycling of heavy metals. Among the potentially toxic metals, mercury, lead, cadmium, nickel, arsenic, selenium and chromium could be named as the most toxic. Each of these elements is used in industrial activities and most of them are considered as by-products of mining, refining and similar industrial activities. Although the establishment of cement factories is usually associated with job creation and other economic aspects, the purpose of economic interests, is inevitable environmental damage caused by cement factories. Therefore, research on pollution originated from factories appears to be necessary. In order to determine the effect of cement production on farmland around Shahrood cement factory, soil samples were taken from surface soils from depth of 0-30 cm. The samples were analyzed using atomic absorption spectrometer instrument after samples preparation using standard frequently used methods. Soil magnetic susceptibility of the samples was also measured using Saskopto meters MFK1-FA. The results showed that among the parameters studied, the element of Zinc has shown the lowest mean value equal to 0.31 mg·kg-1 and iron has shown the highest mean value equal to 6.36 mg·kg-1.

Prediction of the Microstructural Variations of Cold-Worked Pure Aluminum during Annealing Process  [PDF]
Hamid Reza Rezaei Ashtiani, Peyman Karami
Modeling and Numerical Simulation of Material Science (MNSMS) , 2015, DOI: 10.4236/mnsms.2015.51001
Abstract: The mechanical properties such as hardness and ultimate tensile strength of metals depend on the grain size, which have to be properly controlled and optimized to ensure the better economy and desirable mechanical characteristics of the metals. In order to study the microstructure evolution of AA1070, many experimental tests were conducted at different cold working and annealing conditions. Utilizing the experimental results, the static recrystallization and grain growth behavior of AA1070 have been investigated and the developed equations that can be used to the FEM of the annealing process have been obtained. The agreement between numerical modeling and experimental results is reasonably good for this material. The results showed that the recrystallization and grain growth behavior of AA1070 was evidently affected by both the annealing temperature and plastic strain.
Modeling of Rotary Kiln in Cement Industry  [PDF]
Hamid Reza Goshayeshi, Fariba Kerdar Poor
Energy and Power Engineering (EPE) , 2016, DOI: 10.4236/epe.2016.81003
Abstract: Cement production is a highly energy-intensive process, and the rotary kiln is the most important part of the process. Having a comprehensive model of the kiln in order to reduce manufacturing costs, better performance can be created. In this paper, the influence processes in a simulated cement rotary kiln and operating parameters on the output of the study were to develop and validate the systems using the same batch. The followings were examined: solid phase, gas and coating temperature change in a rotary kiln.
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