Abstract:Manufacturing technuiques and principles for determining the resistance of large section CFA piles with a “hard core” is considered. The methods for determining averaged diameters of CFA piles and bearing capacity on ground strength are given. The values of calculated resistance of soils under the lower end and on lateral surfaces of averaged diameter of large section CFA piles with a “hard core” are cited. Carrying capacities of large-section CFA piles with a “hard core” on the ground in the form of averaged diameter are determined and compared with carrying capacity of precast piles of section 30x30, same that of a “hard core” with the same length and ground conditions..
Abstract:Biomass is currently considered as a third largest energy source worldwide. Biomass in a powder form is shown to burn like a gas and, in turn, it could be used as a fuel in internal combustion engines (ICEs). Current record models for biomass powder combustion in literature do not incorporate advanced kinetics model for the pyrolysis process in such fast heat working conditions, e.g., flame working conditions in ICEs. The present study aims at developing an appropriate modelling tools to simulate the fast pyrolysis behaviour of biomass powder in ICEs, e.g., combustion working conditions; such pyrolysis models are compulsory to simulate powder biomass flames precisely in the ICEs. The biomass powder in the current study is non-spherical shape with typical micro-scale size particles of range 25-1400 m in diameter and 80-6000 m in length. Different mechanisms for powder biomass pyrolysis both in parallel and series schemes were proposed including the devolatilization kinetics and the rate constants. During biomass pyrolysis process, tar is formed by a rate of 57 wt.%, and, accordingly, tar formation and cracking sub-processes are also modelled in the current study. The proposed pyrolysis models were tested and validated against experimental data and results showed good agreement. The results showed that the tar is formed and cracked between the temperature range between 700 and 1050 K.
Abstract:In recent years, many extreme ice and snow disasters occurred in China. In order to study the physical and mechanical properties and the damage law of high-slope rock mass located in the part of the area under freeze-thaw cycles, marble samples were collected in the Daye iron mine in Huangshi city of Hubei Province, and the freeze-thaw cycle compression tests were carried out in a total of 30 freeze-thaw cycles. After 0, 10, 15, 20, 25, and 30 freeze-thaw cycles, the quality, volume, wave velocity and SEM image of the samples were measured, and the uniaxial compressive failure tests were also carried out for these samples. To analyze the physical and mechanical properties of rock samples, the relationship between the freeze-thaw damage and the number of freeze-thaw cycles and the relationship between the freeze-thaw damage and the freeze-thaw temperature were analyzed. Meanwhile, based on the theory of significance analysis, the effects of the number of freeze-thaw cycles and the freeze-thaw temperature on the physical and mechanical properties of marble were studied. Research results show that the influence of freeze-thaw cycles on the physical and mechanical properties of marble was significant, and the effect of the freezing temperature was weak. With the increase of the number of freeze-thaw cycles, the mass loss, the loss rate of wave velocity and the strength loss rate and freeze-thaw damage of marble specimens increase, but the elastic modulus and the freeze-thaw coefficient decrease. The freeze-thaw cycle has a positive impact on the microscopic damage and failure of rock mass. With the decrease of the freeze-thaw temperature, the mass loss increase, the strength loss rate and the freeze-thaw coefficient decrease. The influences of other parameters are insignificant.
Abstract:The optimization design plays an important role for obtaining successful composite structures with high efficient and safe uses of materials. In addition, submersibles and submarines are particularly weight sensitive. So, this work presents the optimization of sandwich composite pressure hull of submarine in order to increase buckling load capacity, minimize drag force and weight/displacement ratio. The multi-objective optimization is performed using ANSYS parametric design language (APDL). The model of the pressure hull has been developed using sandwich construction having composite face sheets and foam core. The constraints based on failure strength of the pressure hull, incorporating both Tsai-Wu and maximum stress failure criteria for predicting the first-ply failure. The fiber orientation angle and the thickness in each layer, the radii of the ellipse, the ring beams and the stringers dimensions are taken as design variables. A parametric study is conducted to study the effect of design variables up on objectives functions and constraints.
Abstract:Pharmaceutical industry has an essential role in eliminating the deadly diseases and to control the life-threatening ailments in humans and animals. Research and development in the pharmaceutical field has entered in new era where new technologies have been evolved which predicts availability of new remedies in future with more promising results. Continuity of the innovative medicine gives hope for longer life with better quality. This study aims to evaluate the innovative anticancer drugs competition with equivalent generic drugs in the domestic market and status of their primary pharmaceutical patents. The results of this study indicate that various anticancer drugs did not have generic drugs in competition although their primary pharmaceutical patents have been expired long ago. Stakeholders should make cohesive policies for early entries of generic drugs when pharmaceutical patents expire to ensure access of anticancer drugs at affordable prices in Pakistan..
Abstract:Social networks usually incorporate activities and interactions between actors that change regularly and vary with time. Consequently, the basic structure of these networks is dynamic and is progressively growing. Exploring how the structure of these networks changes over time offers perceptions into their evolution patterns, issues that produce the changes, and eventually forecast the future structure of these networks. One of the main structural properties of networks is their community structure – set of nodes highly connected between each other. Since networks change over time, their underlying communities change as well, i.e. they are having frequently nodes and links that appear and disappear over time; consequently, those communities may expand and contract over time. The main goal of this paper is to suggest a new and formal framework for identifying communities incrementally in social networks that change over time. We demonstrate the effectiveness and potential of our proposed framework by evaluating it using real datasets and comparing it with two previous methods. The results confirm that our proposed approach is more powerful at identifying resistant communities over time.
Abstract:This study\'s experimental design is focused on the effectiveness of a nonviolent communication training program implemented among elementary school children. The entire training program was consisted of nine workshops, with each session lasting for two 45-minute lessons. The workshops were designed to address the defined 9 (nine) components of nonviolent communication: (1) perception, (2) feelings, (3) needs, (4) demands, (5) types of verbal abuse, (6) student response to aggression, (7) how to recognize emotions, (8) conflict resolution skills, and (9) types of conflict resolution. Data were collected for each workshop separately by means of self-report instruments (tests), which were designed to enable students’ report on the degree of acquisition of specific components of nonviolent communication. The results indicated that the training program contributed to an increased competence in nonviolent communication among 13- and 14-year old pupils. Furthermore, the results revealed that student response to aggression is the component of the most importance for the program. With teachers often employing a violent communication mode, the authors conclude that further researches, with school teachers in their focus, are particularly needed.
Abstract:MapReduce (MR) is a criteria of Big Data processing model with parallel and distributed large data sets. This model knows difficult problems related to low-level and batch nature of MR that gives rise to an abstraction layer on top of MR. Therefore, several High-Level MapReduce Query Languages built on top of MR provide more abstract query languages, extending the MR programming model. These generic High-Level MapReduce Query Languages remove the burden of MR programming away from the developers and make a soft migration of existing competences with SQL skills to Big Data environment. In this paper, we investigate the very used High-Level MapReduce Query Languages built directly on top of MR that translate queries into executable native MR jobs. We evaluate the performance of the four presented High-Level MapReduce Query Languages : JAQL, Hive, Big SQL and Pig regarding their insight perspectives and ease of programming. The baseline metrics reported are increasing input size, scale-out number of nodes and controlling number of reducers. Through our experimental results, we study technical advantages and limitations for each High-Level MapReduce Query Languages. Finally, we make a summary for developers to choose the High-Level MapReduce Query Languages which fulfill their needs and interests.
Abstract:A356 alloy has a wide range of applications due to an excellent combinations of castability and mechanical properties. A356 alloy matrix composites are widely used for high performance applications such as in automotive, military, aerospace and electricity industries. In this study, A356 aluminum alloy MMCs reinforced with different weight fractions of Al2O3 particles were fabricated by stir casting method. The Influence of casting mould wall thickness during solidification on the properties and microstructure of A356 alloy reinforced with alumina particles on the microstructure and mechanical properties of the produced composites will be studied. The mould wall thickness is one of the casting parameters, which affects the rate of solidification. As the mould wall thickness increases the solidification takes place at fasterrate. The rate of cooling also increases as the mould wall thickness increases, and, consequently, the grains become finer. The microstructure of the casting shows a fineto coarse grains from the outer (near to the inner mould wall) into the inner surface of the casting, which results a higher michardness near to the inner mould wall. The effect of reinforcement content on the microstructure, mechanical properties, and wear resistance of composites will be also investigated. The density measurements of the composites showed that the amount of porosity in the composites is increased with increasing the weight fraction of reinforcement particles. From wear results, it is revealed that the wear rate of the composites is decreased significantly with increasing the content of Al2O3 particles.