Building natural period, T, is a key character in building response for wind and seismic induced forces. In design practice, the period, T, is either estimated from empirical relations proposed by the design codes or determined from analytical or numerical models. The effect of the soil-structure interaction is usually neglected in the design practice and analysis models. This paper uses a sophisticated finite element simulation to investigate the effect of soil-structure modeling on the fundamental period of RC buildings subjected to wind and seismic induced forces. A typical interior building frame has been imitated using the frame element for beams and columns with constrains to model the almost-rigid diaphragm nature for floors and roof while a three-dimensional element has been adopted for the raft foundation and the soil mass. Different sandy soils have been considered. Standard Penetration Test, SPT value, has been taken as an identification index for soil nature. All other soil properties have been estimated based on well-accepted correlations. After applying the gravity dead and live loads, and eigenanalysis has been achieved to show how soil flexibility affects the effective stiffness of the structure and the corresponding natural period. Finally, the results are used to introduce a correction factor to modify the natural period estimated from a linear analysis with ideal supports to reflect the aforementioned effects.
The main objectives of this study were investigating the effects of the maximum size of coarse Attapulgite aggregate and micro steel fiber content on fresh and some mechanical properties of steel fibers reinforced lightweight self-compacting concrete (SFLWSCC). Two series of mixes were used depending on maximum aggregate size (12.5 and 19) mm, for each series three different steel fibers content were used (0.5 %, 1%, and 1.5%). To evaluate the fresh properties, tests of slump flow, T500 mm, V funnel time, and J ring were carried out. Tests of compressive strength, splitting tensile strength, flexural tensile strength, and calculated equilibrium density were done to evaluate mechanical properties. For reference mixes, the
... Show MoreQ-switched lasers widely used in management skin diseases and
sometimes its effect may be inadequate or associated with
cytotoxicity. The current study aimed to investigate the effect of
Q-switched Nd:YAG laser upon cellular elements using in vitro
experimental model. Aqueous solutions of human albumin and pure
calf thymus double strand deoxyribonucleic acid (ctdsDNA)
irradiated with Q-switched Nd:YAG laser at different rates (1, 3 Hz)
and time exposure (up to 60 seconds) using 532 nm (400 mJ) and
1064 (1200 mJ) nm wavelength with fixed spot size of 4 mm. The
effect of laser irradiation on the albumin solution also studied in the
presence of elemental salts of copper, zinc and iron.
Q-switched laser irrad
In the present work, heterojunction diode detectors will be prepared using germanium wafers as a substrate material and 200 nm tin sulfide thickness will be evaporated by using thermal evaporation method as thin film on the substrate. Nd:YAG laser (λ=532 nm) with different energy densities (5.66 J/cm2 and 11.32 J/cm2) is used to diffuse the SnS inside the surface of the germanium samples with 10 laser shots in different environments (vacuum and distilled water). I-V characteristics in the dark illumination, C-V characteristics, transmission measurements, spectral responsivity and quantum efficiency were investigated at 300K. The C-V measurements have shown that the heterojunction were of abrupt type and the maximum value of build-in pot
... Show MoreThe present study aimed to evaluate the effect of lead exposure on hemopoetic system (through the index delta-Aminolevulinic acid dehydratase ?-ALAD activity & hemoglobin concentration (Hb) ) and on iron status (levels of iron Fe, Ferritin Fr, Total iron binding capacity TIBC, percentage of transferine saturation TF%) in 44 Iraqi worker at lead batteries factory. Workers divided into two groups: smokers(n=21) mean aged (37.33±4.82 year)and non smokers(n=23) mean aged(40.78±7.89 year) and 45 healthy subjects mean aged (33.97±5.08)as control group . Activity of ?-ALAD ratio shows significant decrease (p ? 0.05) ,while Hb and hematocrit Hct were non significant (p ? 0.05) in smoker workers more than non smoker as compared to control . The r
... Show MoreIt is well known that monotherapy does not provide therapeutic response in all hypertensive. Somepatients show an excellent response, while in others there is a poor response. Combinationantihypertensive therapy is administered when blood pressure is inadequately controlled bymonotherapy to achieve a balanced and additive antihypertensive effect with minimum adverse effects.Both angiotensin converting enzyme (ACE) inhibitors and dihydropyridine type of calcium antagonistsare well established and widely used in monotherapy. An understanding of differences in themechanism of action of these agents allows a logical approach for the use of these agents as acombination therapy. This study was designed to evaluate the possible beneficial
... Show MoreThe objective of this research to analyze the effectiveness of monetary policy in achieving economic stability and growth for the period 2004-2011 ،This period of time saw a fundamental shift in monetary policy after the issuing new law the Central Bank of the full independence of the monetary authority ،This is Prompt the monetary authority to bring about a change in the philosophy and objectives and the tools used to achieve the desired goals ،Which give them the ability to control the size of the money supply and to achieve price stability Indeed، Monetary policy has been able to achieve the golden triangle of economic stability ،Consisted of staff، exchange rate stability and low and stable general level of prices
... Show MoreThe present paper attempts to find out the role of developmental loans in promoting strategic crops especially the basis stemming from the problem of non - defining economic feasibility study and the negative or positive revenues of developmental loans, directed to Iraqi Agricultural sector in general and Basic strategic crops in particular which resulted in the difficulty of planning and future prediction to grant loans agriculturally directed in terms of quality and quantity and the arbitrary of distributing these loans .the strategic crops have been selected as sample of population where the sample of Basic strategic crops include wheat and barley .The paper has come to several of conclusions mainly are as follows :- the increase in n
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