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1.
Research in Engineering Design - 相似文献
2.
F. Javier Fuentes Vincent Trouvé Emily Blessing Jean-Jacques Cordier Jens Reich 《Fusion Engineering and Design》2013,88(6-8):597-601
The optimization of the manufacturing/assembly tolerances and processes in ITER Experimental Nuclear Fusion Device is one of the key tasks to optimize the fabrication cost, to prevent problems during assembly and to ensure that the critical homogeneity of the magnetic field and the positioning requirements of the plasma facing components can be achieved. This task is further complicated by the strong interplay among the various Tokamak systems, as for instance in the inner region of the machine where the clearances between Central Solenoid, Toroidal Field Coils, Thermal Shield, Vacuum Vessel and In-Vessel components have been minimized for their large influence on the magnetic flux and the overall machine cost.A 3D tolerance simulation analysis of ITER Tokamak machine has been developed based on 3DCS dedicated software. The dimensional variation model is representative of Tokamak functional tolerances and processes, predicting accurate values for the amount of variation on critical areas. In addition, dimensional simulations help to determine the key tolerances that contribute to a particular variation.This paper describes the current status of the Tokamak dimensional variation studies and its management plan, highlighting the status of compliance of allocated tolerances with input requirements. Management of risk issues and corrective actions are also described. 相似文献
3.
Elimination of Perfluorinated Surfactants – Adsorbent Evaluation Applying Surface Tension Measurements 下载免费PDF全文
The adsorption of perfluorooctane sulfonate (PFOS) onto activated carbons, nonfunctionalized polymeric adsorbents, and anion exchange resins was evaluated in batch as well as column experiments. It was found that the total PFOS capacity, adsorption kinetics, breakthrough times, and minimum effluent concentrations were highly dependent on the material properties, such as the inner surface area, pore size, functionalization, and hydrophobic character of the material, and on process parameters like temperature and ionic strength of the solution. The experiments furthermore revealed that surface tension measurements are a suitable method for online determination of PFOS concentrations above a defined value. 相似文献
4.
We present a comprehensive robot development process and its evaluation. We designed this process in the context of a robotics course in high schools. The motivation for designing this new process was improving the robustness and reliability of robots developed by students and preparing students for becoming better designers. The newly designed process proved to be highly successful in designing top quality robots. In the process design, we explored and adapted existing design tools and methods to the specific designers, the nature of the product, the environment, the product needs, and the design context goals. At the end of this thorough design, we selected a synergetic integration of six tools and methods to compose the new comprehensive development process for this product context: conceptual design, fault-tolerant design, atomic requirements, fuzzy logic for control, creative thinking, and microprogramming-based design. The design skills of the students that learned the design process and the performance of robots they designed and participated in an international robotics contest were examined. The high school teams that studied the proposed process won the first places in an international contest. The robots developed by the students had better performance than robots built by engineers and faculty teams. Professional experts rated the robots’ designs as excellent. The students that studied the process demonstrated high level of diverse design skills including creativity and design management capabilities. Additionally, they improved their science subject grades and their attitude toward engineering. Both the results obtained by the study and the authors’ experience in teaching robotics demonstrate that the proposed robot development process could be taught successfully in high school and that it leads to superior robotic products. Our experience also indicates that this process could serve industry design by improving the robustness of robots operating in uncertain environments and supporting fast change management practices. 相似文献
5.
Michael R. Reich 《The International journal of environmental studies》2013,70(3-4):199-207
This paper analyzes Japanese environmental policy to draw lessons about Japanese society and about environmental policy. It critically examines three myths about Japan: the myth of consensus, the myth of centralization, and the myth of rational policy. The paper then discusses the implications of Japan's experiences for the relationship between environmental quality and economic growth, the problems of an administrative system to compensate pollution victims, and the difficulties in establishing a system for environmental impact assessment. Part I of the essay, appears on p. 191 of this journal, examined successes and failures of Japanese environmental policy. 相似文献
6.
From DSM-Based Planning to Design Process Simulation: A Review of Process Scheme Logic Verification Issues 总被引:1,自引:0,他引:1
Planning product development processes (PDP), and particularly new product development (NPD) processes, is complex and challenging. The plan should reflect the product-related knowledge, including the influences of performing changes in one product component on the need to rework the design of other components. Given the complexity, dynamics, and uncertainties of design processes (DPs), the plan evaluation requires simulation tools. The design structure matrix (DSM) is a known method for DP planning. However, the DSM itself does not express all the relevant information required for defining process logic. Many logic interpretations are applicable in different business cases; yet, a consistent method of transforming a DSM-based plan to a logically correct concurrent process model in the case of iterative activities is lacking. A gap was identified between the literature concerning activities sequencing based on DSM and the process modeling literature concerning process verification. This survey systematically classifies the approaches used in DSM-based process planning, and discusses their strengths and limitations with problems related to process modeling logic verification of iterative processes. Demonstration of the logic differences emphasizes the need for simulation-based decision making according to the specific process attributes. 相似文献
7.
8.
Sabrina Reich Dr. Hans Wolfgang Hoeffken Dr. Bettina Rosche Dr. Bettina M. Nestl Prof. Dr. Bernhard Hauer 《Chembiochem : a European journal of chemical biology》2012,13(16):2400-2407
The crystal structure of the “ene” nicotinamide‐dependent cyclohexenone reductase (NCR) from Zymomonas mobilis (PDB ID: 4A3U) has been determined in complex with acetate ion, FMN, and nicotinamide, to a resolution of 1.95 Å. To study the activity and enantioselectivity of this enzyme in the bioreduction of activated α,β‐unsaturated alkenes, the rational design methods site‐ and loop‐directed mutagenesis were applied. Based on a multiple sequence alignment of various members of the Old Yellow Enzyme family, eight single‐residue variants were generated and investigated in asymmetric bioreduction. Furthermore, a structural alignment of various ene reductases predicted four surface loop regions that are located near the entrance of the active site. Four NCR loop variants, derived from loop‐swapping experiments with OYE1 from Saccharomyces pastorianus, were analysed for bioreduction. The three enzyme variants, P245Q, D337Y and F314Y, displayed increased activity compared to wild‐type NCR towards the set of substrates tested. The active‐site mutation Y177A demonstrated a clear influence on the enantioselectivity. The loop‐swapping variants retained reduction efficiency, but demonstrated decreased enzyme activity compared with the wild‐type NCR ene reductase enzyme. 相似文献
9.
The analogy of lateral particle migration in shear flows has been used to investigate the entrainment of oil particles in the inlet region where a Poiseuille flow is assumed. Previous researchers have studied the particle segregation positions and the particle size effect through two-dimensional simulations. In this paper, both two-dimensional and three-dimensional simulations were conducted. The two-dimensional analysis showed that there are two stable off-center segregation positions and one neutrally stable center segregation position for the small particles, while only one stable center segregation position was found for the large particles. The results are similar in three-dimensional simulations except that the center segregation position is more stable than in the two-dimensional case. It should be noted that all the segregation positions are within the backflow region, which means all the oil particles will be rejected from the contact region if the interparticle collisions are ignored. This is supported by experimental observations. 相似文献
10.
S. Reich G. Leitus R. Popovitz-Biro A. Goldbourt S. Vega 《Journal of Superconductivity and Novel Magnetism》2009,22(4):343-346
Magnetic susceptibility measurements of WO3 crystals hydrogen doped on the surface suggest 2D local non-percolated superconductivity with an onset temperature of 120 K.
Observed zero field cooled vs. field cooled magnetization response is characteristic of type II superconductivity. The diamagnetic
response at the critical temperature is field dependent, and is suppressed by a magnetic field of ∼1700 Oe. 相似文献