Continual improvement: A bibliography with indexes, 1992-1993

This bibliography lists 606 references to reports and journal articles entered into the NASA Scientific and Technical Information Database during 1992 to 1993. Topics cover the philosophy and history of Continual Improvement (CI), basic approaches and strategies for implementation, and lessons learned from public and private sector models. Entries are arranged according to the following categories: Leadership for Quality, Information and Analysis, Strategic Planning for CI, Human Resources Utilization, Management of Process Quality, Supplier Quality, Assessing Results, Customer Focus and Satisfaction, TQM Tools and Philosophies, and Applications. Indexes include subject, personal author, corporate source, contract number, report number, and accession number

Systemic side effects of isolated limb perfusion with tumor necrosis factor alpha

The main function of tumor necrosis factor alpha (TNF-a), a small polypeptide shared by all mammals, is probably protection against invading bacteria, parasites and viruses; killing of these microorganisms is facilitated in the presence of TNF-a. However, as its name suggest, TNF-a is also capable of killing tumor cells, in vitro as well as in vivo. This unique capacity has focused the attention on a possible role for this cytokine in the treatment of human cancer. ... Zie: Samenvatting.

MICROELECTRONICS PACKAGING TECHNOLOGY ROADMAPS, ASSEMBLY RELIABILITY, AND PROGNOSTICS

This paper reviews the industry roadmaps on commercial-off-the shelf (COTS) microelectronics packaging technologies covering the current trends toward further reducing size and increasing functionality. Due tothe breadth of work being performed in this field, this paper presents only a number of key packaging technologies. The topics for each category were down-selected by reviewing reports of industry roadmaps including the International Technology Roadmap for Semiconductor (ITRS) and by surveying publications of the International Electronics Manufacturing Initiative (iNEMI) and the roadmap of association connecting electronics industry (IPC). The paper also summarizes the findings of numerous articles and websites that allotted to the emerging and trends in microelectronics packaging technologies. A brief discussion was presented on packaging hierarchy from die to package and to system levels. Key elements of reliability for packaging assemblies were presented followed by reliabilty definition from a probablistic failure perspective. An example was present for showing conventional reliability approach using Monte Carlo simulation results for a number of plastic ball grid array (PBGA). The simulation results were compared to experimental thermal cycle test data. Prognostic health monitoring (PHM) methods, a growing field for microelectronics packaging technologies, were briefly discussed. The artificial neural network (ANN), a data-driven PHM, was discussed in details. Finally, it presented inter- and extra-polations using ANN simulation for thermal cycle test data of PBGA and ceramic BGA (CBGA) assemblies

Prognostics and Health Monitoring for ECU Based on Piezoresistive Sensor Measurements

This dissertation presents a new approach to prognostics and health monitoring for automotive applications using a piezoresistive silicon stress sensor. The stress sensor is a component with promising performance for monitoring the condition of an electronic system, as it is able to measure stress values that can be directly related to the damage sustained by the system. The primary challenge in this study is to apply a stress sensor to system-level monitoring. To achieve this goal, this study firstly evaluates the uncertainties of measurement conducted with the sensor, and then the study develops a reliable solution for gathering data with a large number of sensors. After overcoming these preliminary challenges, the study forms a framework for monitoring an electronic system with a piezoresistive stress sensor. Following this, an approach to prognostics and health monitoring involving this sensor is established. Specifically, the study chooses to use a fusion approach, which includes both model-based and data-driven approaches to prognostics; such an approach minimizes the drawbacks of using these methods separately. As the first step, the physics of failure model for the investigated product is established. The process of physics of failure model development is supported by a detailed numerical analysis of the investigated product under both active and passive thermal loading. Accurate FEM modeling provides valuable insight into the product behavior and enables quantitative evaluation of loads acting in the considered design elements. Then, a real-time monitoring of the investigated product under given loading conditions is realized to enable the system to estimate the remaining useful life based on the existing model. However, the load in the design element may abruptly change when delamination occurs. A developed data-driven approach focuses on delamination detection based on a monitoring signal. The data driven methodology utilizes statistical pattern recognition methods in order to ensure damage detection in an automatic and reliable manner. Finally, a way to combine the developed physics-of-failure and data-driven approaches is proposed, thus creating fusion approach to prognostics and health monitoring based on piezoresistive stress sensor measurements

MACHINABILITY OF ALUMINIUM METAL MATRIX COMPOSITE REINFORCED WITH ALUMINA USING ELECTRO-DISCHARGE MACHINING

Aluminium metal matrix composites (AMMCs) are making inroads in various engineering applications (aviation, marine, automotive parts as diesel engine pistons, cylinder, and brake components) requiring higher strength and stiffness than those offered by conventional aluminium alloys. Traditional machining of AMMCs however is difficult due to hard reinforcement in the AMMC material which tends to wrap around the cutting tool-bit leading to tool breakage. Electro-discharge machining (EDM) has been successfully applied on standard aluminium alloys such as Al 6061 but yet to be tested on 30% Al2O3 reinforced AMMC. In this study, a specific machining performance on 30% Al2O3 reinforced AMMC is assessed in comparison with Al 6061. The characteristics analyzed are surface roughness (Ra), material removal rate (MRR), tool wear ratio (TWR), overcut (OC) and surface morphology. Process parameters used, are peak current, ON-time (pulse duration) and OFF-time (pause duration), were varied in this research to determine the machinability of AMMC reinforced by 30% Al2O3 by using EDM. The research methodology adopted was using design of experiment (DOE) and results from the experiment were analyzed and interpreted. The response surface methodology (RSM) was used to predict the machining performance and empirical mathematical models for Ra, MRR and TWR using Design Expert software. Results showed that peak current, ON-time and OFF-time have influenced on the EDM performance. Machinability of electro-discharge machining of 30% Al2O3 reinforced AMMC composite using electrolytic copper electrode has been proven feasible at certain parameters setting. Nevertheless, EDM machining performance of Al 6061 is better than that of AMMC. For machining at a specific material removal rate, minimal surface roughness, and low overcut can be obtained at low peak current or short ONtime and longer OFF-time however tool wear ratio remains high. Appropriate setting of EDM parameters that results in optimum machining performance have been identified in this research