In practical engineering problems, uncertainty exists not only in external excitations but also in structural parameters. This study investigates the influence of structural geometry, elastic modulus, mass density, and section dimension uncertainty on the stochastic earthquake response of portal frames subjected to random ground motions. The North-South component of the El Centro earthquake in 1940 in California is selected as the ground excitation. Using the power spectral density function, the two-dimensional finite element model of the portal frame’s base motion is modified to account for random ground motions. A probabilistic study of the portal frame structure using stochastic finite elements utilizing Monte Carlo simulation

Extraction and Description of Urease Enzyme Produced from Staphylococcus saprophyticus and study of its effect on kidney and bladder of white mice

       This study was conducted to the college of education ( Ibn Al- Haitham ) – University of Baghdad ( 2001 – 2002 ) to evaluate the barley ( Hordeum vulgare L. ) response to effect of salinity  and salinity with calcium in the growth medium . Seed germination was carried out in petridishs by using the nutrient solution of Arnon and Hoagland containing different concentrations of NaCl ( 0,50,100 and 150 mM ) and these  concentrations with 5mM calcium  sulfate . Plant growth was continued in hydroponic culture in green house for 4 weeks .       Results showed that salinity caused a decrease in the percentage of germination, plant growth ,  pro

The present work aimed to study the SiO2μPs, and NPs effect on the biodegradability of St/PVA blends. The samples were prepared by casting method as PVA, St/PVA blends with different concentrations (30, 40, 50, and 60 %). FTIR test was carried out for the samples preparation. The results proved some changes which might be related to changing in crystallinity of St/PVA matrix as well as physical incorporation of SiO2 μPs, and NPs addition. The enzymatic test and water uptake results proved that increase in weight loss with increases of starch ratio. The lowest weight loss was PVA; the highest weight loss is 60% St/PVA whereas the lowest weight loss is 30%St/PVA for blends involved. SiO2μPs (753.7 nm), and NPs (263.1 nm) were added at d

Nanomaterials have an excellent potential for improving the rheological and tribological properties of lubricating oil. In this study, oleic acid was used to surface-modify nanoparticles to enhance the dispersion and stability of Nanofluid. The surface modification was conducted for inorganic nanoparticles (NPs) TiO₂ and CuO with oleic acid (OA) surfactant, where oleic acid could render the surface of TiO₂-CuO hydrophobic. Fourier transform infrared spectroscopy (FTIR), and Scanning electron microscopy (SEM) were used to characterize the surface modification of NPs. The main objective of this study was to investigate the influence of adding modified TiO₂-CuO NPs with weight ratio 1:1 on thermal-physical propertie

In this study porcelain was prepared by using composition consisting of raw materials with in following fractions , 50% kaolin , 25% feldspar, and 25% silica( SiO2) tested by XRay diffraction (XRD) method .Study the effect additives at different concentration from zirconia (ZrO2) (2,5,10,15,20) Wt% on some physical properties of porcelain, the sample is prepared by the conventional manufacturing method , It is found that some physical properties of porcelain changes considerably with the substituent sample, It was found that the increase of zrconia (ZrO2) additive of all our sample produce. Increasing in dielectric constant and bulk density and decreasing with open porosity and dielectric loss tangent

Vacuum evaporation technique was used to prepare pure and doped ZnS:Pb thin films at10% atomic weight of Pb element onto glass substrates at room temperature for 200 nm thickness. Effect of doping on a.c electrical properties such as, a.c conductivity, real, and imaginary parts of dielectric constant within frequency range (10 KHz - 10 MHz) are measured. The frequency dependence of a.c conductivity is matched with correlated barrier hoping especially at higher frequency. Effect of doping on behavior of a.c mechanism within temperature range 298-473 K was studied.

This research studying the phenomenon of Doppler (frequency Doppler) as a method through which the direction and speed of the blood cells flows in blood vessels wear measured. This Doppler frequency is relied upon in medicine for measuring the speed of blood flow, because the blood flow is an important concept from the concepts of medicine. It represents the function and efficient of the heart and blood vessels in the body so any defect in this function will appear as a change in the speed of blood flow from the normal value assumed. As this speed changes alot in cases of  disease and morbidity  of the heart, so in order to identify the effect of changing the Doppler frequency on the speed of blood flow and the relationship of