Role of Technology in Manufacturing Competitiveness

A manufacturing revolution has emerged in the past 50 years that is as significant as the industrial revolution of the 19th century. From 1950 to 2000, the average productivity growth in manufacturing in the United States was 2.8% per year, and this figure has been accelerating for the past two decades as manufacturing productivity growth has exceeded the average of other sectors by more than one percent per year (please see table below). Stated more simply, a US manufacturing worker can produce four times as much per hour today as compared with fifty years ago. This gain has resulted from competitive pressures, the advent of new technologies, and a series of product and process innovations. It has also resulted in a much higher standard of living for Americans, as products become more useful and more affordable. In order to utilize this new manufacturing capacity, U.S. firms (and others) have expanded their marketing abroad, creating rapid increase in global trade. The perception of a crisis in American manufacturing is the result of one of the most difficult realities of large gains in productivity: additional capacity almost always exceeds increased consumption. This results in an inevitable shift of labor. Industries become more productive as they mature, and competitive pressures increase. These two factors require companies to decrease their workforce and often result in movement of commodity industries overseas. The end result is a loss of jobs in the United States. Displaced workers must shift to new occupations, requiring new skills and abilities. History has shown that this shift can be either detrimental or beneficial to workers; the most important determinant of benefit is the presence of innovative new industries, which, create high value for their markets. The sustainability of growth in the U.S. manufacturing sector is based on the ability of America to continue to innovate. Innovation is the key to a vibrant U.S. manufacturing base and continued generation of new jobs

Simulation and sensitivity analysis of controlling parameters in resistance spot welding

This study was performed to investigate the fundamental parameters controlling the nugget growth. The parameters were categorized into four groups, i.e. material parameters, electrical parameters, thermal parameters and geometrical parameters. In order to quantify the sensitivity of nugget growth to changes in these parameters, a numerical model which incorporates the electrical, mechanical and thermal contact was developed. As a result, a sensitivity index table was constructed and analyzed to ascertain the relative importance of these characteristic parameters. It was found that the most important factor in determining the variability of nugget growth behavior is the ratio of contact radius to electrode radius and the ratio of electrode radius to the square of specimen thickness. In general for a variation of 10%, the geometrical parameters are most important, followed by the material parameters. The electrical parameters and the thermal parameters are the least important. The importance of contact at the faying interface is greater for the contact area than for the contact resistance

Paper Session I-A - In-Space Welding Visions & Realities

This paper establishes the value of having an in-space welding capability and identifies its applications, both near-term for Shuttle-Spacelab missions and Space Station Freedom, and longer-term for the First Lunar Outpost and Manned Mission to Mars. The leading candidate technologies, consisting of Electron Beam, Gas Tungsten Arc, Plasma Arc, and Laser Beam, are examined against the criteria for an in-space welding system. Research and development work to date, striving to achieve an in-space welding capability, is reviewed. Finally, a series of strategic NASA flight experiments is discussed as the remaining development required for achieving a complete in-space welding capability, which can fully serve the Space Exploration Initiative. This paper summarizes the visions and realities associated with in-space welding

Oxygen Transport Ceramic Membranes

The present quarterly report describes some of the initial studies on newer compositions and also includes newer approaches to address various materials issues such as in metal-ceramic sealing. The current quarter's research has also focused on developing a comprehensive reliability model for predicting the structural behavior of the membranes in realistic conditions. In parallel to industry provided compositions, models membranes have been evaluated in varying environment. Of importance is the behavior of flaws and generation of new flaws aiding in fracture. Fracture mechanics parameters such as crack tip stresses are generated to characterize the influence of environment. Room temperature slow crack growth studies have also been initiated in industry provided compositions. The electrical conductivity and defect chemistry of an A site deficient compound (La{sub 0.55}Sr{sub 0.35}FeO{sub 3}) was studied. A higher conductivity was observed for La{sub 0.55}Sr{sub 0.35}FeO{sub 3} than that of La{sub 0.60}Sr{sub 0.40}FeO{sub 3} and La{sub 0.80}Sr{sub 0.20}FeO{sub 3}. Defect chemistry analysis showed that it was primarily contributed by a higher carrier concentration in La{sub 0.55}Sr{sub 0.35}FeO{sub 3}. Moreover, the ability for oxygen vacancy generation is much higher in La{sub 0.55}Sr{sub 0.35}FeO{sub 3} as well, which indicates a lower bonding strength between Fe-O and a possible higher catalytic activity for La{sub 0.55}Sr{sub 0.35}FeO{sub 3}. The program continued to investigate the thermodynamic properties (stability and phase separation behavior) and total conductivity of prototype membrane materials. The data are needed together with the kinetic information to develop a complete model for the membrane transport. Previous report listed initial measurements on a sample of La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-x} prepared in-house by Praxair. Subsequently, a second sample of powder from a larger batch of sample were characterized and compared with the results from the previous batch

A systematic review of psychosocial interventions for family carers of palliative care patients

<p>Abstract</p> <p>Background</p> <p>Being a family carer to a patient nearing the end of their life is a challenging and confronting experience. Studies show that caregiving can have negative consequences on the health of family carers including fatigue, sleep problems, depression, anxiety and burnout. One of the goals of palliative care is to provide psychosocial support to patients and families facing terminal illness. A systematic review of interventions for family carers of cancer and palliative care patients conducted at the start of this millennium demonstrated that there was a dearth of rigorous inquiry on this topic and consequently limited knowledge regarding the types of interventions likely to be effective in meeting the complex needs of family carers. We wanted to discern whether or not the evidence base to support family carers has improved. Furthermore, undertaking this review was acknowledged as one of the priorities for the International Palliative Care Family Carer Research Collaboration <url>http://www.centreforpallcare.org</url>.</p> <p>Methods</p> <p>A systematic review was undertaken in order to identify developments in family carer support that have occurred over the last decade. The focus of the review was on interventions that targeted improvements in the psychosocial support of family carers of palliative care patients. Studies were graded to assess their quality.</p> <p>Results</p> <p>A total of fourteen studies met the inclusion criteria. The focus of interventions included psycho-education, psychosocial support, carer coping, symptom management, sleep promotion and family meetings. Five studies were randomised controlled trials, three of which met the criteria for the highest quality evidence. There were two prospective studies, five pre-test/post-test projects and two qualitative studies.</p> <p>Conclusions</p> <p>The systematic review identified a slight increase in the quality and quantity of psychosocial interventions conducted for family carers in the last decade. More rigorous intervention research is required in order to meet the supportive care needs of family carers of palliative care patients.</p

Variation in Lightning Simulations to Assess Grounding Safety of Corrugated Stainless Steel Tubing (CSST)

Abstract Codes and standards for lightning often rely on simulations due to the difficult nature of lightning testing, as in the case of corrugated stainless steel tubing (CSST). A small set of simulations by CSST manufacturers were previously used to justify the suggestion that grounding CSST would make it safe from perforation in the presence of lightning. Such a small set of simulations does not account for the uncertainty of lightning and the situations where it may interact with CSST. We account for these uncertainties in this work by performing thousands of simulations that use different combinations of simulation parameters. For example, for one scenario we run 2560 simulations with a variety of different waveforms and different impedance values. The waveforms follow IEC 62305 with rise times ranging from 0.25 \upmuμs to 10 \upmuμs and fall times ranging from 100 \upmuμs to 1000 \upmuμs and the impedance values were varied by ± $$25\%$$25%. Our results show that there are cases where grounding may prevent perforation, cases where grounding may reduce the damage but not prevent perforation and cases where grounding increases the chances of perforation. Our results further show that for lightning strikes with peak current greater than the median, there was never a case where grounding could have prevented perforation. Our methods provide a way to perform more comprehensive simulations to replicate what may happen in nature and better inform decisions made about codes and standards. In particular we show grounding of CSST will not prevent fires when assaulted by lightning with any reasonable degree of certainty

Flexible Water Hose Failures: A Case Study and General Design Considerations

Flexible water hoses (or flexible hose connectors) have become commonplace in recent years and provide a low-cost and convenient alternative to rigid pipe. Unfortunately, inadequate designs, particularly with regard to the selection of materials and material parameters, have made some hoses prone to failure. Such failures are often initiated by incidental exposure to corrosive substances commonly found in homes (including chlorides in tap water) that attack and corrode the stainless steel metal braid. A failure of the braid then leads to a rupture of the water-carrying tube. We evaluate the design considerations pertinent to flexible water hose failures and consider a recent failure scenario that illustrates some key points

The matrix of coefficients in order of magnitude scaling

This paper introduces the matrix of coefficients, which summarizes the physical insight into a problem. This matrix is part of a larger methodology, Order of Magnitude Scaling, which provides closed form estimations of the unknowns, their range of validity, and a set of dimensionless groups that indicate the true ratio of driving forces. These results are obtained even when the problems are described by non-linear partial differential equations. Order of Magnitude Scaling focuses on problems with many driving forces and relatively simple geometries. The matrix of coefficients is the starting point for obtaining these results in a systematic way through matrix operations. This methodology can be computationally much faster than methods that numerically integrate the governing equations, and does not present convergence problems.