The field of structural optimization (optimal design) has grown rapidly over the past decades with many different optimization methods that could be used to produce a structure of minimum weight. This research deals with two aspects, in the first, a general numerical technique based on the finite element analysis and it suggests to investigate the preliminary behavior of metal stiffened plate under action of static load environment. The technique was included a finite element model of the structures using high- order isoparimetric plate elements to be used to create a certain models to obtain their optimum design. The models are characterized such that, each model is builded using different types of stiffener configuration. The second aspect was concerned with the investigation of the optimum design configuration of the structures. The optimization techniques used is called Morphing Evolutionary Structural Optimization (MESO). The Morphing ESO was examined in this research to be applied on stiffened plate structures. The Morphing ESO is based on the simple concept that by slowly removing efficient material from a structure, the residual shape evolves in the direction of making the structure better. The mathematical representation of this method is accomplished in this thesis with full programming and modification required being applicable to a new structure with a new condition. Where the thickness of the plate and stiffeners, and the stiffener height are the design variable. While the objective of the optimization is the structure weight and inequality constraints are the maximum Von Misses stress required for each structure.
In this work, a single pile is physically modeled and embedded in an upper liquefiable loose sand layer overlying a non-liquefiable dense layer. A laminar soil container is adopted to simulate the coupled static-dynamic loading pile response during earthquake motions: Ali Algharbi, Halabjah, El-Centro, and Kobe earthquakes. During seismic events with combined loading, the rotation along the pile, the lateral and vertical displacements at the pile head as well as the pore pressure ratio in loose sandy soil were assessed. According to the experimental findings, combined loading that ranged from 50 to 100% of axial load would alter the pile reaction by reducing the pile head peak ground acceleration, rotation of the pile, and lateral displacem
... Show MoreIn this paper, a theoretical study to the effect of journal misalignment on the static characteristics of oil filled porous journal bearing when lubricated with couple stress fluid has been carried out.
The analytical model used through this work is for a bearing with isotropic permeability. Considering isotropic permeability the Reynolds' equation for the oil film is modified to include a so – called filter term and the effect of fluid coupled stress. The pressure equation for the porous medium is obtained from Darcy's law and continuity equation. The equation which was used to evaluate the oil film thickness was modified to include the effect of possible misalignment in longitudinal and transverse directions. The governing eq
... Show MoreConclusion The observation of the phenomenon of structural evolution of the international system and its instability on a particular situation, by its transition from unipolar to polarity to bipolarism and then to unilateralism in the early 1990s led by the United States, and to the present moment, To say that the structure by which the hierarchy of superpowers or the regime is directed in terms of its various capacities that qualify it, and with the consent of the rest of the States directing the regime to lead and lead the world's first place, has no direct relation to the stability of this system, I hope other more influential in its stability. The structure of the new international order will be completely different in terms of the r
... Show MoreIn this research an experimental study has done for testing the thermal performance of selective surfaces used in solar collectors for substrate of iron, galvanized iron and aluminum which are commercially available. The coating process for the samples has done in two ways, the electroplating and the chemical spray pyrolysis. The results of the thermal performance test of these samples are comparing with the thermal performance of a sample without paint and other paint with black paint without shines commercially available. For the electroplated samples, the performance study has done for different immersion time in plating bath, the
distance between electrical poles, the current density, and area ratio of the sample plated area to
One of the most important virulence factors in Pseudomonas aeruginosa is biofilm formation, as it works as a barrier for entering antibiotics into the bacterial cell. Different environmental and nutritional conditions were used to optimize biofilm formation using microtitre plate assay by P. aeruginosa. The low nutrient level of the medium represented by tryptic soy broth (TSB) was better in biofilm formation than the high nutrient level of the medium with Luria Broth (LB). The optimized condition for biofilm production at room temperature (25 °C) is better than at host temperature (37 °C). Moreover, the staining with 0.1% crystal violet and reading the biofilm with wavelength 360 are considered essential factors in
... Show MoreAn experimental study was carried out to improve the surface roughness quality of the stainless steel 420 using magnetic abrasive finishing method (MAF). Four independent operation parameters were studied (working gap, coil current, feed rate, and table stroke), and their effects on the MAF process were introduced. A rotating coil electromagnet was designed and implemented to use with plane surfaces. The magnetic abrasive powder used was formed from 33%Fe and 67% Quartz of (250µm mesh size). The lubricant type SAE 20W was used as a binder for the powder contents. Taguchi method was used for designing the experiments and the optimal values of the selected parameters were found. An empirical equation representing the r
... Show MoreObjective: to evaluate the benefit of coverage of
the urethral repair by dorsal dartos flap as a second
layer for preventing fistula and V like incision on
the tip of the glans for preventing meatal stenosis.
Patients and Methods:
Forty five children included in this study age
ranged ( 11 months – 7 years), they underwent
hypospadias repair between December 2008 to
March 2012, all cases with distal hypospadias,
same technique used for all patients, a combination
of techniques used for reconstruction starting
withtubularized incised plate urethroplasty with deepithelialized
or stripping of the skin from both
sides of U shaped incision surrounding the urethral
plate, adding a V like incision on t
This experimental research was conducted to quantify the combined effect of the external bonded Carbon Fiber Reinforced Polymer (CFRP) plate width and prestressing on the flexural performance of reinforced concrete (RC) beams in terms of strength improvement. Seven beams (one control and six strengthened) were subjected to two-point loading tests. The experimental methodology consisted of the testing of three different widths of the CFRP plates (25, 40, and 60 mm) in non-prestressed and prestressed conditions. Prestressing was accomplished by tensioning the plates to 23% of the CFRP tensile strength using a novel, locally developed mechanical anchorage system, which is one of the key experimental contributions that distinguishes thi
... Show MoreAbstract: Stories, which are the result of a short text, adventure or experience description, reflect real or possible events-situations. Ömer Seyfettin, the representative of event storytelling in Turkish literature, is an important writer with his nationalist and patriotic identity. Ömer Seyfettin, who wrote many works in the genre of stories, generally addressed the social, historical and psychological issues of the founding years of the Republic of Turkey in these stories, as well as themes such as national values, human psychology, moral issues and social changes. The aim of this study is to examine the sentence structure in Ömer Seyfettin's stories called Miracle. The limitations of the study are determin
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