Ti6Al4V alloy is widely used in aerospace and medical applications. It is classified as a difficult to machine material due to its low thermal conductivity and high chemical reactivity. In this study, hybrid intelligent models have been developed to predict surface roughness when end milling Ti6Al4V alloy with a Physical Vapor Deposition PVD coated tool under dry cutting conditions. Back propagation neural network (BPNN) has been hybridized with two heuristic optimization techniques, namely: gravitational search algorithm (GSA) and genetic algorithm (GA). Taguchi method was used with an L27 orthogonal array to generate 27 experiment runs. Design expert software was used to do analysis of variances (ANOVA). The experimental data were divided randomly into three subsets for training, validation, and testing the developed hybrid intelligent model. ANOVA results revealed that feed rate is highly affected by the surface roughness followed by the depth of cut. One-way ANOVA, including a Post-Hoc test, was used to evaluate the performance of three developed models. The hybrid model of Artificial Neural Network-Gravitational Search Algorithm (ANN-GSA) has outperformed Artificial Neural Network (ANN) and Artificial Neural Network-Genetic Algorithm (ANN-GA) models. ANN-GSA achieved minimum testing mean square error of 7.41 × 10−13 and a maximum R-value of 1. Further, its convergence speed was faster than ANN-GA. GSA proved its ability to improve the performance of BPNN, which suffers from local minima problems.
In this work a hybrid composite materials were prepared containing matrix of polymer (polyethylene PE) reinforced by different reinforcing materials (Alumina powder + Carbon black powder CB + Silica powder). The hybrid composite materials prepared are: • H1 = PE + Al2O3 + CB • H2 = PE + CB + SiO2 • H3 = PE + Al2O3 + CB + SiO2 All samples related to electrical tests were prepared by injection molding process. Mechanical tests include compression with different temperatures and different chemical solutions at different immersion times The mechanical experimentations results were in favour of the samples (H3) with an obvious weakness of the samples (H1) and a decrease of these properties with a rise in temperature and the increasing
... Show Moreالاستثمار الاجنبي المباشر في العراق ودوره في تحقيق التنمية الاقتصادية
Abstract
Tourism is one of the essential economic fields of many countries, both developed and developing. The social plays a greater role in the continuous awareness of a tourist culture based on the need to attract tourists continuously. the tourism heritage and state-owned tourism are the main factors in attracting more tourists. The interest in this strategic sector makes the country the first and most active framework in the development of appropriate mechanisms for investment in this sector, all within the framework of sustainable development of society through the rational use of resources obtained by various bodies in the implementation of seve
... Show MoreThis study aimed to clarify the importance of ecological taxation in achieving sustainable development, by analyzing a set of economic measures such as taxes, taxes levied by the legislation in the field of ecology, to fight against pollution. And we tried to evaluate this initiative in Algeria. The results of the study showed that economic measures of ecological taxation contribute to achieving sustainable development, and Although Algeria has adopted a series of ecological tax mechanisms, it is far from keeping pace with developments in this area.
This paper addresses the nature of Spatial Data Infrastructure (SDI), considered as one of the most important concepts to ensure effective functioning in a modern society. It comprises a set of continually developing methods and procedures providing the geospatial base supporting a country’s governmental, environmental, economic, and social activities. In general, the SDI framework consists of the integration of various elements including standards, policies, networks, data, and end users and application areas. The transformation of previously paper-based map data into a digital format, the emergence of GIS, and the Internet and a host of online applications (e.g., environmental impact analysis, navigation, applications of VGI dat
... Show MoreA field experiment was conducted to grow the wheat crop during the fall season 2020 in Karbala province, north of Ain Al-Tamr District in two locations of different textures and parent materials. The first site (calcareous soil) with a sandy loam texture, is located at (44° 40′ 37′) east longitude and (32° 41′ 34′) north latitude, at an altitude of 32 m above sea level, and an area of 20 hectares. As for the second location (gypsum soil) with a loam texture, it is located at a longitude (45° 41′ 39′) east and a latitude (33° 43′ 34′ north) and at an altitude of 33 m above sea level and an area of 20 hectares. To find out the effect of different tillage systems on water productivity and wheat yield under center pivot irri
... Show MoreThe research aims to derive the efficient industrial plans for Al – shaheed public company under risk by using Target MOTAD as a linear alternative model for the quadratic programming models.
The results showed that there had been a sort of (trade- off) between risk and the expected gross margins. And if the studied company strives to get high gross margin, it should tolerate risk and vice versa. So the management of Al- Shaheed Company to be invited to apply the suitable procedures in the production process, in order to get efficient plans that improves it's performance .
The aim of the research is to determine the extent to which young people watch television sports programs and the impact of viewing on the level of sports culture among young people and the impact of demographic variables on youth over the viewing of sports programs, The study was conducted on a sample of (200) male and female students from the faculties of the University of Baghdad, where a questionnaire form composed of several axes and questions was prepared to measure the effectiveness of sports programs in youth culture, The statistical program used spss to empty data and extract results by frequency, percentages, correlations, The research reached several results, the most important of which is that there is a strong influence of s
... Show MoreThe present study aimed to investigate the histology of the testis in golden hamster during 1, 28 and 60 day of old. Tissue samples were processed, sectioned and subjected to specific stains to reveal histological details. Observation of one day old showed the testicle enclosed by undifferentiated thin layer of testicle capsule which consisted of undifferentiated myoblasts and fibroblasts small size seminiferous tubules appeared, one layer of spermatogonium cells (Type-A) which revealed mitotic figures, at 28 day old the capsule was consisted of thick outer fibromuscular layer and thick inner vascular layer that revealed encouraged blood vessels and cells, Spermatogonial cells type-A & B appeared as large
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