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Showing 7 results for Simplex

Behrooz Farshi, Mohammad. Hossein. Faezi,
Volume 9, Issue 1 (12-2009)
Abstract

Abstract There are numerous applications for gas turbine discs in the aerospace industries such as in turbojet engines. These discs normally work under high temperature while subjected to high angular velocities. Minimizing the weight of such items in aerospace applications results in benefits such as low dead weights and lower costs. Optimization of rotating discs is historically, an area of research due to their vast utilization in industry. The gas turbine disc is one of examples to name. Gas turbine discs work mostly at high temperature gradients and are subjected to high angular velocities. High speed results in large centrifugal forces in disc and simultaneous high temperatures reduces the disc material strength, thus the later increases stress in disc automatically. In order to obtain a reliable disc analysis and arrive at the corresponding correct stress distribution, solution should consider changes in material properties due to the temperature field throughout the disc. To this end, an inhomogeneous disc model with variable thickness is considered. Using the variable material properties method, stresses are obtained for the disc under rotation and a steady temperature field. In this paper this is done by modeling the rotating disc as a series of different rings with constant properties. The optimum disc profile is arrived at by sequentially proportioning the thickness of each ring to satisfy stress requirements. In this paper these are done using the simplex method. Simplex algorithm is applied in Ansys software and the results are presented.

Volume 11, Issue 0 (10-2009)
Abstract

Objective: Herpes simplex virus (HSVs) is a widespread human infectious agent, responsible for persistent and latent infections. Herpes simplex virus infections are usually continually recurrent in the normal population and represent a significant cause of complications in immunocompromised patients. Materials and Methods: In this study HSVs were propagated in BK cells and more than 502 samples were taken and analyzed for HSV IgG antibodies using Virus Neutralization Test (VNT) as golden standard test for evaluating in house Enzyme Linked Immunosorbent Assay (ELISA). Results: Based on the results 80.48 % and 81.67% were positive (1.8) in VNT and ELISA respectively. There was a significant correlation between the VNT and ELISA tests in the tested samples (Pearson’s r = 0.96). Conclusions: Our data showed that the in house ELISA can be used for screening and determination of the prevalence of HSV IgG antibodies, which can facilitates patient management using suitable and cost effective laboratory diagnostic tests.
, , Mahdi Fakoor,
Volume 13, Issue 7 (10-2013)
Abstract

In this paper, a new method based on Pareto Simplex Search (PSS) has been employed to find the communications satellite optimal transfer trajectory from geosynchronous transfer orbit (GTO) to geosynchronous orbit (GEO) as the destination operational zone. We solve this problem through using a mathematically efficient algorithm and in all transferring phases, considering transfer orbits to intermediate orbits; it is supposed that the orbital maneuver control unit has continuous performance characteristics. The system governing equations representing the two body system of a spacecraft and primary gravitational source and thrust force applying to spacecraft, are defined in a nonlinear form. In this systematic approach we incorporate system dynamics as the problem constraints, and both minimum-time and fuel consumption using constant acceleration simultaneously as the problem strategy to find the optimal transfer trajectory between two orbits. Set of optimal trajectories are plotted in Pareto Front and transfer trajectory can be selected from these points.

Volume 14, Issue 4 (3-2012)
Abstract

Objective: Infection with herpes simplex virus type 1 induces viral latency in neuron trigeminal ganglions. The late associated transcript (LAT) is uniquely expressed in infected neural cells, however no coding protein associated with these transcripts has been identified in infected cells. It has been shown that six microRNAs transcribed from LAT have the capabilities to affect the cell signaling pathways, thus interfering in pathways such as those of cell differentiation and proliferation. Transforming growth factor beta (TGF-β) pathway is a critical pathway among cell signaling circuits. The Smad4 protein, as an important member of the TGF-β signaling pathway, mediates the connection between membrane receptors, cytoplasmic kinases, and nuclear transcription factors. Methods: This study bioinformatically and experimentally evaluated LAT microRNA expression and assessed microRNA targeting of Smad4 transcripts in human neuroblastoma cells by using real-time PCR. Results: Analysis of two different softwares results showed that the Smad4 gene was targeted by LAT-derived microRNAs at multiple sites. Over-expression of LAT microRNAs in BE2(c) cells caused reduction in Smad4 transcripts. Conclusion: The results of bioinformatical analysis with relative quantification of Smad4 transcripts and its downstream-related genes such as cyclinD, CDK2, and Myc showed that the LAT transcript could control Smad4 expression.
Mohammad Hossein Mozaffari, Mahmud Khodadad,
Volume 14, Issue 10 (1-2015)
Abstract

One of the most important issues in industry, particular casting industry is to determine the internal structure of objects such as identifying the interfacial boundary configurations between material, identification of impurities or mechanical properties of the material. The objective of the present inverse problem is to identified simultaneously two regular interfacial boundary configurations and mechanical properties of the components of a multiple (three) connected domains using a discrete number of displacement measurements obtained from an uniaxial tension test. A unique combination of a global optimization method i.e. the Imperialist Competitive Algorithm (ICA) and local optimization methods i.e. Simplex Method (SM) along with the inverse application of the Boundary Elements Method (BEM) are employed in an inverse software package. A fitness function, which is the summation of squared differences between the measured displacements and computed at identical locations on the exterior boundary, is minimized. The obtained results (run-time and error-rate), clearly demonstrate the efficiency of this present algorithm (the Imperialist Competitive Algorithm and Simplex Method) to optimize the objective function and the estimation simultaneously two regular interfacial boundary configurations and mechanical properties.
Mousa Rezaee, Reza Fathi, Arash Mohammad Alizadeh Fard,
Volume 14, Issue 14 (3-2015)
Abstract

The forces due to the unbalance in a system cause undesired vibration and noise, and reduce the system life. One of the new and efficient methods used to reduce the unbalance is the use of automatic dynamic ball balancer. The automatic dynamic ball balancer is a typical passive balancer which doesn't need control systems to balance the rotor. Because these devices are used in the systems which have variable unbalance according to the operating conditions and the system may be switched on and off several times a day, therefore reducing the balancing time becomes a necessary task. In practice, the gyroscopic effect is created for several reasons, e.g. when the rotor is located offset from the shaft midspan. Previous studies have not determined the optimum values of the damping ratio and mass of balls of the automatic dynamic ball balancer under the gyroscopic effect. In this study, the effect of damping ratio and the mass of balls of the automatic dynamic ball balancer on the stability and balancing of the system under the gyroscopic effect have been investigated and, using the Nelder-Mead simplex algorithm, the optimum values of these parameters to minimize the time of balancing and converging the Euler angles to zero are obtained.

Volume 18, Issue 3 (5-2016)
Abstract

The detection of Genetically Modified (GM) organisms is becoming a legal necessity. This study was carried out to detect genetically modified events in soybeans imported into Iran using simplex and multiplex PCR. Therefore, five samples of imported soybean were obtained from Bandar Imam Khomeini customs. Modified CTAB method was used to extract DNA from soybean seeds. The result indicates that the modified method is suitable for DNA extraction from soybean seeds and probably can be used for other oilseeds. Using specific primers for CaMV 35S promoter, NOS terminator and epsps gene PCR reactions were performed. In this study soybean lectin gene was used as internal control. The results revealed that soybean samples imported from Canada and Paraguay were genetically modified and they had CaMV 35S promoter, NOS terminator and epsps gene in their genomes. The result of simplex PCR was the same as multiplex PCR, but multiplex PCR detected the GM soybeans very quickly and in a cost-saving and time-consuming way. Based on PCR analysis using GM soybean event-specific primers, it is suggested that the soybean plants may be GTS 40-3-2. No fragment was amplified when the DNA of US or Non-GM soybeans were used as template in the PCR reaction. This is the first report that shows GM soybeans imported to Iran without use of the "GMO" label in the shipment's documentation.

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