An Adaptive Geometry Transformation and Repair Method for Hybrid Manufacturing

Author(s):  
Maxwell Praniewicz ◽  
Thomas Kurfess ◽  
Christopher Saldana

Hybrid manufacturing has become particularly attractive for refurbishing of high-value freeform components. Components may experience unique geometric distortions and/or wear-driven material loss in service, which require the use of part-specific, adaptive repair strategies. The current work presents an integrated adaptive geometry transformation method for additive/subtractive hybrid manufacturing based on rigid and nonrigid registrations of parent region material and geometric interpolation of the repair region material. In this approach, rigid registration of nominal part geometry to actual part geometry is accomplished using iterative alignment of profiles in the parent material. Nonrigid registration is used to morph nominal part geometry to actual part geometry by transformation of the profile mean line. Adaptive additive and subtractive tool paths are then used to add material based on constant stock margin requirements, as well as to produce blend repairs with smooth transition between parent and repair regions. A range of part deformation conditions due to profile twist and length changes are evaluated for the case of a compressor blade/airfoil geometry. Accuracy of the resulting adaptive geometry transformation method were quantified by (1) surface comparisons of actual and transformed nominal geometry and (2) blend region surface accuracy. Performance of the adaptive repair strategy relative to a naïve strategy is evaluated by the consideration of material efficiency and process cycle time. It is shown that the adaptive repair strategy resulted in an increase in material efficiency by 42.2% and a decrease in process time by 17.8%, depending on the initial deformation imposed on the part geometry.

2020 ◽  
Vol 251 ◽  
pp. 119731 ◽  
Author(s):  
A. Wippermann ◽  
T.G. Gutowski ◽  
B. Denkena ◽  
M.-A. Dittrich ◽  
Y. Wessarges

2006 ◽  
Vol 3 (1) ◽  
pp. 27
Author(s):  
Mustaffa Samad

The Internet has been an integral part of the Information and Communication Technology (ICT) community in recent years. New internet users have been growing steadily over the years. This has lead to the depletion of new Internet Protocol (IP) addresses worldwide. To overcome this predicament, the new Internet Protocol version 6 (IPv6) had been introduced. The existing Internet Protocol version 4 (IPv4) is expected to be eventually replaced by this IPv6. The changeover from IPv4 to IPv6 is expected to be implemented progressively. During this transition period, these two protocols are expected to coexist for a number of years. IPv4-to-IPv6 transition tools have been designed to facilitate a smooth transition from IPv4 to IPv6. The two most basic IPv4-to-IPv6 transition tools available are the hybrid stack mechanism and tunneling. Tunneling is the encapsulation of IPv6 traffic within IPv4 packets so they can be sent over an IPv4 infrastructure. This project was initiated to set up an experimental IPv6 testbed, in order to study the performance as well as transition and migration issues of IPv6 networks under controlled conditions. This paper looks at how tunneling can be performed over existing internetwork infrastructure at Fakulti Kejuruteraan Elektrik (FKE), UiTM.


2019 ◽  
Author(s):  
john andraos

This paper proposes a standardized format for the preparation of process green synthesis reports that can be applied to chemical syntheses of active pharmaceutical ingredients (APIs) of importance to the pharmaceutical industry. Such a report is comprised of the following eight sections: a synthesis scheme, a synthesis tree, radial pentagons and step E-factor breakdowns for each reaction step, a tabular summary of key material efficiency step and overall metrics for a synthesis plan, a mass process block diagram, an energy consumption audit based on heating and cooling reaction and auxiliary solvents, a summary of environmental and safety-hazard impacts based on organic solvent consumption using the Rowan solvent greenness index, and a cycle time process schedule. Illustrative examples of process green synthesis reports are given for the following pharmaceuticals: 5-HT2B and 5-HT7 receptors antagonist (Astellas Pharma), brivanib (Bristol-Myers Squibb), and orexin receptor agonist (Merck). Methods of ranking synthesis plans to a common target product are also discussed using 6 industrial synthesis plans of apixaban (Bristol-Myers Squibb) as a working example. The Borda count method is suggested as a facile and reliable computational method for ranking multiple synthesis plans to a common target product using the following 4 attributes obtained from a process green synthesis report: process mass intensity, mass of sacrificial reagents used per kg of product, input enthalpic energy for solvents, and Rowan solvent greenness index for organic solvents.<br>


Author(s):  
Jangbae Jeon

Abstract This work presents a novel method of continuous improvement for faster, better and cheaper TEM sample preparation using Cut Look and Measure (CLM). The improvement of the process is executed by operational monitoring of daily beam conditions, end products, bulk thickness control, recipe usage and tool running time. This process produces a consequent decrease in rework rate and process time. In addition, it also increases throughput with better quality TEM samples.


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