665 research outputs found

    Study of effect of shear wall in the seismic response of the existing buildings

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    In Iraq, it has been observed that an increase in seismic activity, and that most existing buildings are not seismically designed and that can suffer serious damage or collapse, thus causing loss of life. In this paper, a numerical simulation of the experimental laboratory sample on the subject of non-seismically designed buildings and methods of strengthening them was performed using a seismic strengthening technique using an infill RC wall in order to maintain the risk of earthquakes. This study was carried out through the work of verifying the numerical and practical model by matching the results of laboratory work with the results of numerical analysis using the analysis finite element analysis method (FEAM) by Abaqus CAE 2019 software and then using the model to study the effect of openings in the infill RC walls and the extent of its impact on the response of the building. The practical model is a full four-story building tested laboratory in Elsa, Italy using pseudo dynamic test (PSD). The experimental model is a sample of not seismically design buildings (gravity design only) and ways to improve them by adding new RC walls with different contact details to the existing building. The goal of the experimental test was to study the effectiveness of adding RC infill walls with two types (North and South) infill RC walls, including designing it and the contribution of two types of dowels that connect the new infill walls to the existing RC building. In other words, it’s a way of strengthening by converting selected bays into RC walls with two types of reinforcement and connection between new infill RC walls and existing builders called (north and south) frames. The results of analytical modeling show that the percentage of differences in X- Direction of top story displacement between Abaqus software and Experimental tested at ELSA results are 2.47% in positive and 3.12% for negative X direction, which refer to a very good similarity and accurate building simulation

    Study the tensile strength for epoxy composite reinforced with fibers and particles

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    : This research include the study of tensile strength for the polymer and the composite materials, we using the epoxy resin as matrix for the reinforced materials that consist of artificial fibers (Kevlar, glass and PVC fibers) also aluminum powder for reinforcing.The slates made of composite materials and hybrid composite materials for both volume fractions 20% and 40% from the reinforced materials, Twenty one slates were made from the composite materials, all these slates were cut into samples with measurement (10x 80mm) in order to execute the tensile strength test for both volume fractions 20% and 40%. The results and laboratory examinations for these samples shows increase in the tensile strength for composite materials when the volume fraction increase from 20% to 40% for reinforced material, the samples from type (EK) have tensile strength is higher than all samples for both volume fraction

    Enhancement of the Tensile and the Compression Properties for Heat- Cured Acrylic Resin Denture Base Materials

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    This work aims to investigate the tensile and compression strengths of heat- cured acrylic resin denture base material by adding styrene-butadiene (S- B) to polymethyl methacrylate (PMMA). The most well- known issue in prosthodontic practice is fracture of a denture base. All samples were a blend of (90%, 80%) PMMA and (10%, 20%) S- B powder melted in Oxolane (Tetra hydro furan). These samples were chopped down into specimens of dimensions 100x10x2.5mm to carry out the requirements of tensile tests. The compression strength test specimens were shaped into a cylinder with dimensions of 12.7mm in diameter and 20mm in length. The experimental results show a significant increase in both tensile and compression strengths when compared to control (standard) results for the preparation material

    Node-Replication Attack Detection in Vehicular Ad-hoc Networks based on Automatic Approach

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    Recent advances in smart cities applications enforce security threads such as node replication attacks. Such attack is take place when the attacker plants a replicated network node within the network. Vehicular Ad hoc networks are connecting sensors that have limited resources and required the response time to be as low as possible. In this type networks, traditional detection algorithms of node replication attacks are not efficient. In this paper, we propose an initial idea to apply a newly adapted statistical methodology that can detect node replication attacks with high performance as compared to state-of-the-art techniques. We provide a sufficient description of this methodology and a road-map for testing and experiment its performance

    Synthesis , characterization and electrical properties of conductive polyaniline/ functionalized MWCNT nanocomposites

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    by in situ polymerization of aniline monomer, conducting polyaniline (PANI) nanocomposites containing various concentrations of carboxylic acid functionalized multi-walled carbon nanotubes (f-MWCNT) were synthesized. The morphological and electrical properties of pure PANI and PANI /MWCNT nanocomposites were examined by using Fourier transform- infrared spectroscopy (FTIR), X-ray diffraction (XRD) and Atomic Force Microscopy (AFM) respectively. FTIR spectra shows that the carboxylic acid groups formed at the both ends of the sidewalls of the MWCNTs. The aniline monomers were polymerized on the surface of MWCNTs, depending on the -* electron interaction between aniline monomers and MWCNTs and hydrogen bonding into interaction between the amino groups of aniline monomers and carboxylic acid group of f-MWCNT. The AC, DC, electrical conductivities of pure PANI and PANI/MWCNT nanocomposite have been measured in frequency range (10Hz-100KHz) and in the temperature range from (30 to 160 C°). the results shows the electrical conductivity of the nanocomposite is higher than pure PANI. AC conductivity at low frequencies is independent of frequencies and increased by increasing the MWCNTs concentration

    CT SCAN IMAGES ANALYSIS OF MAXILLARY SINUS DIMENSIONS AS A FORENSIC TOOL FOR SEXUAL AND RACIAL DETECTION IN A SAMPLE OF KURDISH POPULATION

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    Despite the fact that the skull and other bones may be badly disfigured in victims who are incinerated, it became an urgent necessity to gender determination using maxillary sinuses as a useful tool of human skeletons in forensic medicine. The aim of the study: to determine the reliability and accuracy of maxillary sinus dimension measurement as a method for gender and racial identification through the use of reconstructed helical CT images. Material and Methods: This prospective study included cranial computerized tomography images (CT) of 119 (M: 57 and F: 62) of the Kurdish population of Sulaimani city of Iraq with an age range (20 - 75) years. All patients were examined on Spiral Computed Tomography Scanner from October 2014 to March 2015.The greatest measurements were taken from the width, length, and height of the maxillary sinuses. The descriptive and discriminate analyzes were performed by using the SPSS package program. Results The mean of the length, the width, and the height of maxillary sinus in males on both right and left sides were (35.90± 4.71, 36.63 ± 5.34) (25.74 ± 5.69 , 25.36 ± 6.03) and (32.86 ± 7.00 , 33.13± 6.87) mm, respectively but in females were (34.58 ± 4.21, 35.60 ± 3.94 ), (22.54 ± 4.74 and 21.53 ± 4.47) and (29.16 ± 7.20,29.25 ± 6.17 )mm respectively. The present study showed that the left maxillary sinus width was the best discrimination parameter, that could be used to study sex dimorphism with Prediction of 69.4% for female and 52.6% for male (overall accuracy = 61. 3%). The discriminative analysis showed that the accuracy of maxillary sinus measurements-i.e the ability of the maxillary sinus size to identify gender-was 71% in females and 56.1% of males (overall accuracy = 63.9%). Conclusion The study showed that the diameters of the maxillary sinus can be used as a guide and a useful tool for racial and sex determination

    CT SCAN IMAGES ANALYSIS OF MAXILLARY SINUS DIMENSIONS AS A FORENSIC TOOL FOR SEXUAL AND RACIAL DETECTION IN A SAMPLE OF KURDISH POPULATION

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    Despite the fact that the skull and other bones may be badly disfigured in victims who are incinerated, it became an urgent necessity to gender determination using maxillary sinuses as a useful tool of human skeletons in forensic medicine. The aim of the study: to determine the reliability and accuracy of maxillary sinus dimension measurement as a method for gender and racial identification through the use of reconstructed helical CT images. Material and Methods: This prospective study included cranial computerized tomography images (CT) of 119 (M: 57 and F: 62) of the Kurdish population of Sulaimani city of Iraq with an age range (20 - 75) years. All patients were examined on Spiral Computed Tomography Scanner from October 2014 to March 2015.The greatest measurements were taken from the width, length, and height of the maxillary sinuses. The descriptive and discriminate analyzes were performed by using the SPSS package program. Results The mean of the length, the width, and the height of maxillary sinus in males on both right and left sides were (35.90± 4.71, 36.63 ± 5.34) (25.74 ± 5.69 , 25.36 ± 6.03) and (32.86 ± 7.00 , 33.13± 6.87) mm, respectively but in females were (34.58 ± 4.21, 35.60 ± 3.94 ), (22.54 ± 4.74 and 21.53 ± 4.47) and (29.16 ± 7.20,29.25 ± 6.17 )mm respectively. The present study showed that the left maxillary sinus width was the best discrimination parameter, that could be used to study sex dimorphism with Prediction of 69.4% for female and 52.6% for male (overall accuracy = 61. 3%). The discriminative analysis showed that the accuracy of maxillary sinus measurements-i.e the ability of the maxillary sinus size to identify gender-was 71% in females and 56.1% of males (overall accuracy = 63.9%). Conclusion The study showed that the diameters of the maxillary sinus can be used as a guide and a useful tool for racial and sex determination

    EFFECT OF H2SO4 ACID ON FATIGUE FAILURE PROPERTY FOR POLYMER MATRIX COMPOSITE

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    :This research include the study of the fatigue property for the polymer and the composite materials, we using the epoxy resin as matrix for the reinforced materials that consist of artificial fibers (Kevlar, glass and PVC fibers) also aluminum powder for reinforcing. The slates made of composite materials and hybrid composite materials for both volume fractions30% and 40% from the reinforced materials, where we made twenty one slates from the composite materials, all these slates cutting to samples with measurement (10x 70mm) in order to execute the fatigue test accordingly for the fatigue machine characteristics, these samples divided to several groups for both volume fractions 30% and 40%, these groups immersing in H2SO4 acid for fifty day to study the effect of this solution in the fatigue characteristic. The test executed by two steps: - the first step include executing the fatigue testing for the dry samples and comparison these results with each other, the second step include the fatigue test for the samples after immersion in the solution (H2SO4 acid) for fifty day,. The results of fatigue test from the second step comparing with the results from the first group for both volume fractions 30% and 40%. The results and laboratory examinations for these samples show a decreasing in the number of fatigue cycles until the fail when the applied load or applied stress increas
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