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Go to Editorial ManagerThe objective of the present paper is to evaluate the effects of the soil-structure interaction on the seismic evaluation in the building when a framed building is supported on raft foundation. Also the foundation-soil interaction effect has been considered by replacing it with equivalent springs. Nonlinear static pushover analyses of eight-storey reinforced concrete hospital building located at Delhi-India has been performed using the Capacity Spectrum Method of ATC-40. The deformations define the state of damage in the structure through three limit states of the NEHRP Guidelines and the FEMA-356 have been used to evaluate the performance level of the building for drift, the plastic hinge stage of the crack and shear under the condition of the fixed base and the effect of the soil-structure interaction. The performance of the building and individual components has been estimated for Design Basis Earthquake and Maximum Considered Earthquake. The weight of the slab was distributed as triangular and trapezoidal loads to the surrounding beams as per IS 456:2000. The weight of the brick masonry was distributed uniformly on the beams. The results show that the soil structure interaction has marked effect on the roof displacement, storey drift, design base shear, effective damping and crack pattern for beams and columns while there is a minor effect on the torsional behavior of the building. The building is more critical in the performance level when considering the soil flexibility.
Nowadays, it is crucial to assess power system contingencies resulting from line outages or generator failures, as they might cause breaches of system constraints. This is a vital part of ensuring the security of modern power supplies. Another hindrance to providing electricity to consumers is the increased system losses and voltage fluctuations resulting from increased demand and diminished power generation capacity. The DG connection is a crucial subject regarding these harmful consequences. This study is focused on clarifying the effect of distribution generators (DG) on mitigating congestion in electrical power transmission lines, minimizing power losses, and enhancing the voltage profile of the Iraqi national grid system. An optimization method is used to identify the optimal size and position based on fitness indicators such as voltage, power losses, and line congestion. The PSO algorithm is executed as proposed. The outcomes illustrate the effectiveness of the proposed technique for estimating the optimal size and placement of distributed generators (DG). At the same time, it reduces congestion and improves the voltage level of the bus. The proposed technique was implemented using the MATLAB/R2018a programming language.
Construction projects are complex projects and their organisations are characterised by a high degree of fragmentation since they are distributed in large areas and clearly they involves of many activities, each one being divided into sub-activities and so on. Hear clear and good communication between projects stakeholders leads to the project being more successful in contrast to when the communication is weak. This paper compares two methods of communication used in Iraqi construction projects during the implementation stage, namely the Face to Face (FTF) approach which is characterised as expensive and disruptive and Computer Mediated Communication (CMC) which represents the modern method in the communication field. The results show that the CMC method is more productive and economic than FTF and takes less time when completing an implementation work; in addition, the people are less affected by emotional factors in the construction project in contrast to FTF.
This study is to investigate the effect of partially replacement of coarse aggregate by waste plastic and using the paper sludge as additive material at concrete, on the hardened concrete properties and its impact on structural behavior of the reinforced concrete members (slab, column, and beam). Plastics and paper are widely used in daily life in huge amounts. Both incineration and landfilling are options for disposing of plastic and paper waste, but either one could be harmful to the environment. Therefore, reducing waste or increasing its value can reduce pollution and reduce disposal costs. The variables of the experimental program include the ratio of waste plastic and paper sludge, the used ratios for plastic and paper were (5%, 10%, and 15%) by volume. Hardened concrete properties were investigated for concrete include: flexural strength, modulus of elasticity, and splitting tensile strength. For each structural reinforced member, the (Load – Deflection) curve has been extracted. The study shows that the plastic waste negatively affects most of concrete properties. The research indicates that using waste plastic in reinforced concrete members with percentage of (5% and 10%) by volume as a partially replacement of coarse aggregate giving acceptable results. However, when adding (5%) by mixture volume of waste paper in reinforced concrete members, the load-deflection behavior and ultimate load-bearing capacity have been improved. In general, using waste plastic and paper sludge in concrete mixtures lead to reduction in ultimate load ranging between (4.62%-10.82%) for slab under point load, (4.85-18.99%) slab under distributed load, (3.72%-12.21%) column, and (1.78%-7.16%) beam specimens respectively.
The weight function prescribing the sensitivity of the electromagnetic flowmeter (EM}') to the changes in the velocity profiles must be as much as possible uniformly distributed through the measuring volume. The most commonly used criterion of the weight function distribution is a statistical quantity ( e criterion) which deals with only the axial component of the weight vector. In the present work, attempt 10 introduces a more revealing and accurate criterion to the EMF performance was studied. The curl of the weight function vector over the measuring volume has been considered and formulated (and termed as e ) in such a mathematical expression that takes Into account the contributions of the three components of the weight vector regardless of the geometry of the cross-sectional area of the flow. In addition, a numerical solution of a previously defined criterion (ey) is presented here for the first time in order to compare the validity of the newly introduced criterion. The results showed that the present new criterion e is closely harmonious with the previously defined criteria 8 and Si.. in the conventional flow cases. The results and the configuration of the formula of the present criterion, which is independent of the flow cross-sectional led us to conclude that is more reliable and applicable than other existing criteria.
Al-Robat and Al-Jubyla creeks, which composes the study area, are two of the main six creeks branched from Shatt Al- Arab river in Basrah province, south of Iraq. They are used as open drains for discharging untreated sanitary sewage which caused the depletion of their dissolved oxygen and subsequently the deterioration of their water quality. To study the impact of discharging untreated sanitary sewage on study area water quality, measured in terms of dissolved oxygen concentration, it is necessary to determine the values of deoxygenation coefficient ( K 1 ). The aim of this study is to find K 1 values for the study area using laboratory results of BOD time series analyses. For this purpose, water samples were collected from eight locations distributed along the study area. Thomas graphical method was applied to calculate K 1 . The results showed that the K 1 values for Al-Robat and Al-Jubyla creeks ranged from 0.279 to 0.488 day ˗ 1 at 20 °C with ultimate BOD values varied over the range (40.5-258.6) mg/l. These results revealed that the water in Al-Robat and Al-Jubyla creeks has the characteristics of raw sewage.
The use of fiber-optic links as the connecting media in wireless microcellular networks can be provide uniform radio coverage to spatially distributed mobile users in cost effective manner. This paper investigates theoretically the performance of fiber distribution system for mobile phone networks that uses a single high power Nd:YAG laser in the base station and shared by many microcells. Analytical expressions are derived for the bit-error-rate (BER) floor characteristics and optimum operating conditions. The results indicate clearly that the laser power can be reduced significantly when the modulation index is optimized.
The surge tank is one of important control devices in reducing water Hummer effect on distributed network piping system and hydropower stations. An experimental study was conducted into a simple surge tank of 0.044 m in a diameter with upstream constant head reservoir of a height, 0.881 m and a water transporting pipe of a size 0.0202 m. Results indicate that rapid closure of a downstream valve causes under-damped stable oscillation in a surge tank. Experimental response agreed well with theoretical results when friction factor is considered to be variable, but with 85 % increases in settle time and more oscillations when constant friction factor is recognized at initial value before valve closure. Doubling surge tank area does not improve the dynamics properties; otherwise, Thoma area must be avoided for small sizes. Comsol multiphysics software 3.5 is used to deal with the dynamics of the surge tank numerically.
In this paper, a new approach for the positioning (localization) of multi-node systems is presented. Each node including the beacon node contains two types of sensors: one for the distance sensing and the other type is for communication. The main idea of our proposed approach is to use the control of beacon to construct a nodes' tree which is going to be used later by the nodes to know the paths in which the information will flow. During the tree construction the identities of nodes will be known. Every node except the beacon will use the information obtained from its previous neighbor in the tree to find its own location and orientation. Several simulations using visual basic 2012 are implemented to discern the performance of this algorithm.
An investigation was conducted to study the effect of loading level with respect to shear center and span length on lateral torsional buckling of steel I-section beams using linear and nonlinear finite element analysis available in ANSYS (version 12.0) computer program. The steel beams which have been studied included prismatic beams and linearly web- tapered beams with web tapering ratio of (0.5). The maximum height of all beams was 300 mm with span length of 4, 6 and 8 m. The critical buckling loads for prismatic and linearly tapered cantilever and simply supported beams subjected to point load and uniformly distributed load were determined. The results showed that, the bottom flange loading gives a buckling loads higher than that of the top flange loading with percentage increases of 148% and 155% for the linear and nonlinear analysis respectively for the prismatic beams. While for the tapered beams, these percentages increases were 61% and 67% respectively.