Effect of shear-coupled grain boundary motion on coherent precipitation

We examine the interaction between precipitates and grain boundaries, which undergo shear-coupled motion. The elastic problem, emerging from grain boundary perturbations and an elastic mismatch strain induced by the precipitates, is analysed. The resulting free elastic energy contains interaction terms, which are derived numerically via the integration of the elastic energy density. The interaction of the shear-coupled grain boundary and the coherent precipitates leads to potential elastic energy reductions. Such a decrease of the elastic energy has implications on the grain boundary shape and also on the solubility limit near the grain boundary. By energy minimisation we are able to derive the grain boundary shape change analytically. We apply the results to the Fe-C system to predict the solubility limit change of cementite near an $\alpha$-iron grain boundary.Comment: 8 page

A review of stencil printing for microelectronic packaging

PurposeThe purpose of this paper is to present a detailed overview of the current stencil printing process for microelectronic packaging.Design/methodology/approachThis paper gives a thorough review of stencil printing for electronic packaging including the current state of the art.FindingsThis article explains the different stencil technologies and printing materials. It then examines the various factors that determine the outcome of a successful printing process, including printing parameters, materials, apparatus and squeegees. Relevant technical innovations in the art of stencil printing for microelectronics packaging are examined as each part of the printing process is explained.Originality/valueStencil printing is currently the cheapest and highest throughput technique to create the mechanical and electrically conductive connections between substrates, bare die, packaged chips and discrete components. As a result, this process is used extensively in the electronic packaging industry and therefore such a review paper should be of interest to a large selection of the electronics interconnect and assembly community.</jats:sec

Exploring the bullwhip effect by means of spreadsheet simulation.

An important supply chain research problem is the bullwhip effect: demand fluctuations increase as one moves up the supply chain from retailer to manufacturer. It has been recognized that demand forecasting and ordering policies are two of the key causes of the bullwhip effect. In this paper we present a spreadsheet application, which explores a series of replenishment policies and forecasting techniques under different demand patterns. It illustrates how tuning the parameters of the replenishment policy induces or reduces the bullwhip effect. Moreover, we demonstrate how bullwhip reduction (order variability dampening) may have an adverse impact on inventory holdings. Indeed, order smoothing may increase inventory fluctuations resulting in poorer customer service. As such, the spreadsheets can be used as an educational tool to gain a clear insight into the use or abuse of inventory control policies and improper forecasting in relation to the bullwhip effect and customer service. Keywords: Bullwhip effect, forecasting techniques, replenishment rules, inventory fluctuations, spreadsheet simulationBullwhip; Bullwhip effect; Forecasting techniques; Inventory fluctuations; Replenishment rule; Simulation; Spreadsheet simulation;

Exploring the bullwhip effect by means of spreadsheet simulation.

One of the main supply chain deficiencies is the bullwhip effect: demand fluctuations increase as one moves up the supply chain from retailer to manufacturer. The Beer Distribution Game is widely known for illustrating these supply chain dynamics in class. In this paper we present a spreadsheet application, exploring the two key causes of the bullwhip effect: demand forecasting and the type of ordering policy. We restrict our attention to a single product two-echelon system and illustrate how tuning the parameters of the replenishment policy induces or reduces the bullwhip effect. We also demonstrate how bullwhip reduction (dampening the order variability) may have an adverse impact on inventory holdings and/or customer service. As such, the spreadsheets can be used as an educational tool to gain a clear insight into the use of inventory control policies and forecasting in relation to the bullwhip effect and customer service.Bullwhip effect; Replenishment rules; Forecasting techniques; Spreadsheet simulation; Beer distribution game;