4,054 research outputs found

    Application of Cryogenic Treatment to Extend the Life of the TiAlN-Coated Tungsten Carbide Milling Cutter

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    Cutting tools are important to the manufacturing industry since they will affect production efficiency and product quality. Cryogenic treatment can improve the material properties by decreasing residual stress, stabilizing dimensional accuracy, and increasing wear resistance. The purpose of this study is to investigate the feasibility and effect of cryogenic treatment on the performance of TiAlN-coated tungsten carbide milling cutters for machining the Inconel alloy 625 in terms of different testing methods (e.g., hardness, wear resistance, residual stress, microstructure, and tool life test). Experimental results indicate that after cryogenic treatment there is less wear, the microstructure is denser, residual stress is decreased, the adhesion of coating and tungsten carbide is improved, and the tool life is effectively improved

    Automated unit-level testing with heuristic rules

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    Software testing plays a significant role in the development of complex software systems. Current testing methods generally require significant effort to generate meaningful test cases. The QUEST/Ada system is a prototype system designed using CLIPS to experiment with expert system based test case generation. The prototype is designed to test for condition coverage, and attempts to generate test cases to cover all feasible branches contained in an Ada program. This paper reports on heuristics sued by the system. These heuristics vary according to the amount of knowledge obtained by preprocessing and execution of the boolean conditions in the program

    Thermodynamic curvature measures interactions

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    Thermodynamic fluctuation theory originated with Einstein who inverted the relation S=kBlnΩS=k_B\ln\Omega to express the number of states in terms of entropy: Ω=exp(S/kB)\Omega= \exp(S/k_B). The theory's Gaussian approximation is discussed in most statistical mechanics texts. I review work showing how to go beyond the Gaussian approximation by adding covariance, conservation, and consistency. This generalization leads to a fundamentally new object: the thermodynamic Riemannian curvature scalar RR, a thermodynamic invariant. I argue that R|R| is related to the correlation length and suggest that the sign of RR corresponds to whether the interparticle interactions are effectively attractive or repulsive.Comment: 29 pages, 7 figures (added reference 27

    Applying the ARPSO Algorithm to Shafting Alignment Optimization Design

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    Trial-and-error method for shafting alignment at the initial design stage in the shipbuilding industry is mostly carried out by shipyard designers. However, adjusting of a highly sensitive shaft line within a short period in order to obtain a reasonable positive design value for each bearing reaction force (load) and bearing pressure for the entire propulsion shafting system is very difficult. Any minor changes in the bearing location and/or off-set design values may cause different analytical results with a large design deviation, such that the fi nal design result may not comply with the classifi cation society requirements and manufacturers’ design criteria. The innovative ARPSO-SHAALIN design program successfully combines and integrates the Three Moment Equation Method (TMEM) for a continuous beam with the Attractive and Repulsive Particle Swarm Optimization (ARPSO) algorithm. The ARPSO algorithm searches for the values of global optimal design parameter for each bearing off-set and location of the propulsion shafting in the initial design stage in order to create a brand new optimal shafting arrangement. Design results are verifi ed and presented

    The development of a program analysis environment for Ada

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    A unit level, Ada software module testing system, called Query Utility Environment for Software Testing of Ada (QUEST/Ada), is described. The project calls for the design and development of a prototype system. QUEST/Ada design began with a definition of the overall system structure and a description of component dependencies. The project team was divided into three groups to resolve the preliminary designs of the parser/scanner: the test data generator, and the test coverage analyzer. The Phase 1 report is a working document from which the system documentation will evolve. It provides history, a guide to report sections, a literature review, the definition of the system structure and high level interfaces, descriptions of the prototype scope, the three major components, and the plan for the remainder of the project. The appendices include specifications, statistics, two papers derived from the current research, a preliminary users' manual, and the proposal and work plan for Phase 2
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