Time-domain spectral matching commonly used to define seismic inputs to dynamic analysis in terms of acceleration time history compatible with a specific target response spectrum is used in this study to investigate the second-order geometric effect of P-delta on the seismic response of base-isolated high-rise buildings. A synthetic time series is generated by adjusting reference time series that consist of available readings from a past earthquake of the 1940 El Centro earthquake adopted as an initial time series. The superstructure of a 20-story base isolated building is represented by a 3-D finite element model using ETABS software. The results of the base isolated building show that base isolation technique significantly reduces inter-story drift and acceleration of the superstructure. Results presented reflect the potential of synthetic time history analysis to capture base isolator characteristics and to show their effect on the results of the dynamic analysis when compared to target response spectrum analysis. Geometric nonlinear analysis due to P-delta reveals that p-delta effect reduces base shear and story acceleration by about 5%, whereas inter-story drifts increased by about 3%. This study shows that including geometric nonlinearity due to p-delta reduces pseudo acceleration of the superstructure and hence the earthquake-induced forces in the structure.
In this paper, a dynamic investigation is done for strip, rectangular and square machine foundation at the top surface of two-layer dry sand with various states (i.e., loose on medium sand and dense on medium sand). The dynamic investigation is performed numerically using finite element programming, PLAXIS 3D. The soil is expected as a versatile totally plastic material that complies with the Mohr-Coulomb yield criterion. A harmonic load is applied at the base with an amplitude of 6 kPa at a frequency of (2 and 6) Hz, and seismic is applied with acceleration – time input of earthquake hit Halabjah city north of Iraq. A parametric study is done to evaluate the influence of changing L/B ratio (Length=12,6,3 m and width=3 m), type of sand
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Heritage is considered as the civilization and cultural wealth accumulated over the . centuries, whereas architectural heritage is the physical witness of that civilization. Despite the fact that architectural heritage is the most important effort for economic development of any communit,، it suffers from deterioration and neglection especially in the Arab communities. Recently awareness has increased about the importance of investing on architectural heritage generally and sustainable investment particularly. The goal of investment process in heritage areas is to revive economic activity in addition to attempt to revive the heritage and community values. Research aims to examine the relationship between sustainable investment and
... Show MoreEn el contexto iraquí, el análisis de las dificultades léxicas de los estudiantes de ELE es fundamental para poder llevar a cabo prácticas que respondan dos necesidades concretas. Por un lado, ofrecer experiencias de aula que garanticen el desarrollo de competencias comunicativas que optimicen el uso adecuado de la lengua española (L2); por otro, atender a las exigencias que se hacen desde el PCIC y el MCER para tener unos parámetros claros de evaluación. Así las cosas, en este artículo se propone la caracterización de la competencia léxica como parte de las competencias lingüísticas desde la perspectiva del MCER, para señalar cuál es el alcance de su optimización para los estudiantes arabófonos en general y los ira
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Background: Fracture of different types of acrylic denture base is a common problem associated with dental prosthesis. Studies suggested that the repair strength may be improved by several means including surface treatment with chemical agents. The aim of the study was to evaluate the effect of surface treatment with acrybond-bonding agent and monomer on fractured denture base in respect to transverse, tensile and shear bond strength and evaluation of the mode of failure by light microscope. Materials and methods: Two hundred seventy specimens were prepared and divided into 3 groups according to the material used (regular conventional, rapid simplified and high impact) heat cure acrylic. The specimen in each groups were prepared specificall
... Show MoreThe hydraulic behavior of the flow can be changed by using large-scale geometric roughness elements in open channels. This change can help in controlling erosions and sedimentations along the mainstream of the channel. Roughness elements can be large stone or concrete blocks placed at the channel's bed to impose more resistance in the bed. The geometry of the roughness elements, numbers used, and configuration are parameters that can affect the flow's hydraulic characteristics. In this paper, velocity distribution along the flume was theoretically investigated using a series of tests of T-shape roughness elements, fixed height, arranged in three different configurations, differ in the number of lines of roughness element
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Abstract A descriptive (cross sectional) study was conducted to assess psychosocial domain of quality of life for (100) women who had hysterectomy for non malignant indications during 6-12 months post operative. The study carried out in both consultation clinics of Al-Elwiya Maternity Hospital and Baghdad Teaching Hospital from January 5th 2003 to July 10th 2003). The results of the study show that hysterectomy achieved a highly successful outcome in terms of psychological and social adjustments for hysterectomies women, a highly significant differences between quality of life (QoL) and some of demographic cha
Background: preparation of root canals is an important step in root canal treatment. Mechanical instrumentation of root canals cause an irregular layer of debris, known as the smear layer. As a result, several studies reported that preferring the removal of the smear layer. Objective: To study the influence of the energy (100 mJ) of Erbium, Chromium: Yttrium Scandium Gallium Garnet (Er,Cr:YSGG) laser at short pulse duration (60 μs) on smear layer removal of apical third after using Photon induced photoacoustic streaming technique. Materials and methods: Eighteen straight single-rooted mandibular premolars were used. The roots length were uniform to 14mm from the anatomic apex and
... Show MoreThe aim of the current research to determine the extent of logical intelligence in the book of chemistry for the fifth grade of science and to achieve the goal the researcher has prepared a special criterion in the areas of logical intelligence main and sub-to be included in the book after reviewing the previous literature and studies in this regard may be the final form after presentation to experts and arbitrators in the field of Educational and psychological sciences, curricula and teaching methods from (3) main areas and (21) sub-fields, then the researcher analyzed the book Bibih and applied branches and adopted the idea of both explicit and implicit as a unit of registration and repet
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