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

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

RAE-1 ligands for the NKG2D receptor are regulated by E2F transcription factors, which control cell cycle entry.

The NKG2D stimulatory receptor expressed by natural killer cells and T cell subsets recognizes cell surface ligands that are induced on transformed and infected cells and facilitate immune rejection of tumor cells. We demonstrate that expression of retinoic acid early inducible gene 1 (RAE-1) family NKG2D ligands in cancer cell lines and proliferating normal cells is coupled directly to cell cycle regulation. Raet1 genes are directly transcriptionally activated by E2F family transcription factors, which play a central role in regulating cell cycle entry. Induction of RAE-1 occurred in primary cell cultures, embryonic brain cells in vivo, and cells in healing skin wounds and, accordingly, wound healing was delayed in mice lacking NKG2D. Transcriptional activation by E2Fs is likely coordinated with posttranscriptional regulation by other stress responses. These findings suggest that cellular proliferation, as occurs in cancer cells but also other pathological conditions, is a key signal tied to immune reactions mediated by NKG2D-bearing lymphocytes

Mechanical and SEM analysis of artificial comet nucleus samples

Since 1987 experiments dealing with comet nucleus phenomena have been carried out in the DFVLR space simulation chambers. The main objective of these experiments is a better understanding of thermal behavior, surface phenomena and especially the gas dust interaction. As a function of different sample compositions and exposure to solar irradiation (xenon-bulbs) crusts of different hardness and thickness were measured. The measuring device consists of a motor driven pressure foot (5 mm diameter), which is pressed into the sample. The applied compressive force is electronically monitored. The microstructure of the crust and dust residuals is investigated by scanning electron microscopy (SEM) techniques. Stress-depth profiles of an unirradiated and an irradiated model comet are given

Automated unit-level testing with heuristic rules

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

Applying the ARPSO Algorithm to Shafting Alignment Optimization Design

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

Applying the ARPSO Algorithm to Shafting Alignment Optimization Design

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

A Microcantilever-based Gas Flow Sensor for Flow Rate and Direction Detection

The purpose of this paper is to apply characteristics of residual stress that causes cantilever beams to bend for manufacturing a micro-structured gas flow sensor. This study uses a silicon wafer deposited silicon nitride layers, reassembled the gas flow sensor with four cantilever beams that perpendicular to each other and manufactured piezoresistive structure on each micro-cantilever by MEMS technologies, respectively. When the cantilever beams are formed after etching the silicon wafer, it bends up a little due to the released residual stress induced in the previous fabrication process. As air flows through the sensor upstream and downstream beam deformation was made, thus the airflow direction can be determined through comparing the resistance variation between different cantilever beams. The flow rate can also be measured by calculating the total resistance variations on the four cantilevers.Comment: Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/handle/2042/16838

Thermodynamic curvature measures interactions

Thermodynamic fluctuation theory originated with Einstein who inverted the relation $S=k_B\ln\Omega$ to express the number of states in terms of entropy: $\Omega= \exp(S/k_B)$. 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 $R$, a thermodynamic invariant. I argue that $|R|$ is related to the correlation length and suggest that the sign of $R$ corresponds to whether the interparticle interactions are effectively attractive or repulsive.Comment: 29 pages, 7 figures (added reference 27