Circular thin walled structures have wide range of applications. This type of structure is generally exposed to different types of loads, but one of the most important types is a buckling. In this work, the phenomena of buckling was studied by using finite element analysis. The circular thin walled structure in this study is constructed from; cylindrical thin shell strengthen by longitudinal stringers, subjected to pure bending in one plane. In addition, Taguchi method was used to identify the optimum combination set of parameters for enhancement of the critical buckling load value, as well as to investigate the most effective parameter. The parameters that have been analyzed were; cylinder shell thickness, shape of stiffeners section and the number of stiffeners. Furthermore, to verify the contribution of parameters on buckling response, the analysis of variance technique (ANOVA) method was implemented, which gave the contribution weight as percentages. The analysis of results by these two methods showed that the more effective parameter on the critical buckling load was the thickness of cylinder’s shell and the lowest effective was the number of stiffeners The values of parameters that gave the best critical buckling load combination were: 1) the ratio of cylinder’s diameter to thickness of its shell was 133, 2) the ratio of the depth to thickness of stiffeners was1.6, and 3) the number of stiffeners was 12.
Background: Benign Prostate Hypertrophy(BPH)is a common urological problem worldwide which is defined as denomatous hyperplasia of the periurethralpart of prostate gland that occurs especially in men over 50 years old and that tend to obstruct urination by constriction the urethra Objectives: The study was aimed to investigate the level of Malondialdehyde (MDA), Nitric Oxide (NO) and Superoxide Dismutase (SOD) as an antioxidant, besides other factors such as the level of Lipids Profile (Total Chlosterol (TC), High Density Lipoprotein Cholesterol (HDL-C), Low Density Lipoprotein Cholesterol (LDL-C), Very Low Density Lipoprotein Cholesterol (VLDL-C), and Triglyceride (TG))in patients suffer from BPH . Methods: In this study ;clinical ,spec
... Show MoreBackground: Human leukocyte antigen-G (HLA-G)and Toll-like receptor-9 (TLR-9)play a role in the regulation of autoimmune diseases and inflammatory processes. Aim of the study: To detect the HLA-G + 3142G > C gene polymorphism that associated with the susceptibility to SLE patients and associated with Hepatitis B infection and TLR-9 serum level. Patients and methods: This study was done on 75 SLE patients and 75 healthy control groups. Genotyping of HLA-G + 3142G > C were detected by PCR and PCR-RFLP methods. In addition to the estimation of Hepatitis B surface (HBs)antigen status by immunochromatography technique and TLR-9 serum level by ELISA technique. Results: The HLA-G + 3142G > C gene polymorphism between the SLE patients and controls
... Show MorePure and Fe-doped zinc oxide nanocrystalline films were prepared
via a sol–gel method using -
C for 2 h.
The thin films were prepared and characterized by X-ray diffraction
(XRD), atomic force microscopy (AFM), field emission scanning
electron microscopy (FE-SEM) and UV- visible spectroscopy. The
XRD results showed that ZnO has hexagonal wurtzite structure and
the Fe ions were well incorporated into the ZnO structure. As the Fe
level increased from 2 wt% to 8 wt%, the crystallite size reduced in
comparison with the pure ZnO. The transmittance spectra were then
recorded at wavelengths ranging from 300 nm to 1000 nm. The
optical band gap energy of spin-coated films also decreased as Fe
doping concentra
This research was distributed into two sections, the first section was concerned with the concept of value for De Saussair and its methodological impact on his linguistic structural conceptions with respect of the distinction between synchronism and diachronism, the value role of linking function between the sounds and the though, the basing of his theoretical conception on the language being a form and not a material according to this principle and the value impact on the demonstration that the linguistic element acquires its functional importance from the relations inside the language system. It also stopped at the methodological impact of value on defining the analytical linguistic unit and the value role in semantics through the prin
... Show MoreIn this paper the concept of (m, n)- fully stable Banach Algebra-module relative to ideal (F − (m, n) − S − B − A-module relative to ideal) is introducing, we study some properties of F − (m, n) − S − B − A-module relative to ideal and another characterization is given
ABSTRACT Background: Dental caries is a most common social and intractable infectious disease in human. Saliva is critical for preserving and maintaining oral health and salivary elements had many effects on caries experience. Aim of study: This study was conducted to assess dental caries severity by age and gender and their relation to salivary zinc and copper among a group of adults aged (19-22) years. Materials and methods: After examination eighty persons aged 19-22 years of both gender. Caries severity was documented according to DMFS index. Stimulated salivary samples were collected and chemically analyzed under standardized condition to detect salivary elements zinc and copper. Concentrations of Zinc and copper were measured by using
... Show More