Eutectic god-tin (Au80Sn20) is widely used as the die-attach material for making radio-frequency (RF) and microwave devices. The metallic bonding is typically achieved by soldering using a gold-tin preform in a forming gas containing hydrogen (H2) and nitrogen (N2) to a peak temperature at 300 ̊C. The performance and reliability of the devices are strongly dependent on the quality of the die-att...

A continuum sensitivity analysis is presented for the computation of the shape sensitivity of ®nite hyperelastic±viscoplastic deformations involving contact with friction using a direct di€erentiation method. Weak shape sensitivity equations are developed that are consistent with the kinematic analysis, constitutive sub-problem as well as the analysis of the contact/friction sub-problem used in...

To ensure a more uniform forging distribution microstructure and improve the service performance of aeroengine disk parts, an automated preform design method is proposed for integrated shape optimization based on non-uniform rational B-spline (NURBS) curve, finite element method, genetic algorithm (GA). First, random graph automatically constructed by NURBS curve criterion. The volume complexit...

The versatility of the textile weaving process has made it a popular method for producing structural composite preforms. Enhanced through-thickness strength by multi-layer weaving, good in-plane strength and the ability to produce 2.5D or 3D shapes, are some of the advantages which have made weaving the most commonly used textile process for composite applications. It is also possible to incorp...

The preform of human mitochondrial uracil-DNA glycosylase (UNG1) contains 35 N-terminal residues required for mitochondrial targeting. We have examined processing of human UNG1 expressed in insect cells and processing in vitro by human mitochondrial extracts . In insect cells we detected a major processed form lacking 29 of the 35 unique N-terminal residues (UNG1Delta29, 31 kDa) and two minor f...

Binder stabilized preforms are getting increased attention in the wind turbine industry with aim to increase automation production of large blades. In this context a preform is stack dry unidirectional glass fiber non-crimp fabrics (UD-NCF), which consolidated using polymeric binder. The manufactured separate mold, and subsequently placed main blade mold. During placement preforms, wrinkling ma...

Hollow core photonic band gap fibers have great potential in low latency data transmission and power delivery applications, but they are currently only fabricated in research scale fabrication facilities, with km-scale lengths. To drive cost reduction and volume manufacturing it is essential to be able to upscale the preform size, but before embarking on costly experimental attempts it is usefu...

The paper presents a modification of capillary optical fibers fabrication method from an assembled glass preform. A change of dimensional proportions in the capillary optical fiber drawn from a single preform is allowed on-line via the control of overpressure and thermal conditions in the outflow meniscus which essentially lowers the manufacturing costs. These conditions are among the solutions...