Productivity of Federally Financed Research and Development Final Report, May 15, 1963 - May 14, 1966

Research project on federal and industrial patent acquisition and economic implications - NASA PROGRA

A Non-Zeeman Interpretation for Polarized Maser Radiation and the Magnetic Field at the Atmospheres of Late-Type Giants

The linear polarization that is observed, together with likely changes in the orientation of the magnetic field along the line of sight and hence of the optical axes of the medium, can lead to the circular polarization that is observed in the radiation of the circumstellar SiO masers. A magnetic field greater than only about 30 mG is required, in contrast to 10-100 G that would be implied by the Zeeman interpretation. To assess quantitatively the likely changes in orientation of the magnetic field, calculations are performed with representative field configurations that are created by statistical sampling using a Kolmogorov-like power spectrum.Comment: 7 pages Latex (aaspp4.sty), 3 ps-figures. Accepted for publication in Astrophysical Journal Letter

A super-ductile alloy for the die-casting of aluminium automotive body structural components

Super-ductile die-cast aluminium alloys are critical to future light-weighting of automotive body structures. This paper introduces a die-cast aluminium alloy that can satisfy the requirements of these applications. After a review of currently available alloys, the requirement of a die-cast aluminium alloy for automotive body structural parts is proposed and an Al-Mg-Si system is suggested. The effect of the alloying elements, in the composition, has been investigated on the microstructure and mechanical properties, in particular the yield strength, the ultimate tensile strength and elongation. © (2014) Trans Tech Publications, Switzerland.The EPSRC and JLR U

Texture analysis of aggressive and nonaggressive lung tumor CE CT images

This paper presents the potential for fractal analysis of time sequence contrast-enhanced (CE) computed tomography (CT) images to differentiate between aggressive and nonaggressive malignant lung tumors (i.e., high and low metabolic tumors). The aim is to enhance CT tumor staging prediction accuracy through identifying malignant aggressiveness of lung tumors. As branching of blood vessels can be considered a fractal process, the research examines vascularized tumor regions that exhibit strong fractal characteristics. The analysis is performed after injecting 15 patients with a contrast agent and transforming at least 11 time sequence CE CT images from each patient to the fractal dimension and determining corresponding lacunarity. The fractal texture features were averaged over the tumor region and quantitative classification showed up to 83.3% accuracy in distinction between advanced (aggressive) and early-stage (nonaggressive) malignant tumors. Also, it showed strong correlation with corresponding lung tumor stage and standardized tumor uptake value of fluoro deoxyglucose as determined by positron emission tomography. These results indicate that fractal analysis of time sequence CE CT images of malignant lung tumors could provide additional information about likely tumor aggression that could potentially impact on clinical management decisions in choosing the appropriate treatment procedure

Executive computer program for linking independent computer programs: ODINEX

Program controls sequence of execution of network of program elements and maintains data base of common information which forms communication link among them. Approach is applicable to any multiple-program task

Evidence for risk of bias in cluster randomised trials: review of recent trials published in three general medical journals

Objective To examine the prevalence of a risk of bias associated with the design and conduct of cluster randomised controlled trials among a sample of recently published studies. Design Retrospective review of cluster randomised trials published in the BMJ, Lancet, and New England Journal of Medicine from January 1997 to October 2002. Main outcome measures Prevalence of secure randomisation of clusters, identification of participants before randomisation (to avoid foreknowledge of allocation), differential recruitment between treatment arms, differential application of inclusion and exclusion criteria, and differential attrition. Results Of the 36 trials identified, 24 were published in the BMJ, I I in the Lancet, and a single trial in the New England journal of Medicine. At the cluster level, 15 (42%) trials provided evidence for secure allocation and 25 (69%) used stratified allocation. Few trials showed evidence of imbalance at the cluster level. However, some evidence of susceptibility to risk of bias at the individual level existed in 14 (39%) studies. Conclusions Some recently published cluster randomised trials may not have taken adequate precautions to guard against threats to the internal validity of their design

Spectra of Maser Radiation from a Turbulent, Circumnuclear Accretion Disk. III. Circular polarization

Calculations are performed for the circular polarization of maser radiation from a turbulent, Keplerian disk that is intended to represent the sub-parsec disk at the nucleus of the galaxy NGC4258. The polarization in the calculations is a result of the Zeeman effect in the regime in which the Zeeman splitting is much less than the spectral linebreadth. Plausible configurations for turbulent magnetic and velocity fields in the disk are created by statistical methods. This turbulence, along with the Keplerian velocity gradients and the blending of the three hyperfine components to form the $6_{16} - 5_{23}$ masing transition of water, are key ingredients in determining the appearance of the polarized spectra that are calculated. These spectra are quite different from the polarized spectra that would be expected for a two-level transition where there is no hyperfine structure. The effect of the hyperfine structure on the polarization is most striking in the calculations for the maser emission that represents the central (or systemic) features of NGC4258. Information about magnetic fields is inferred from observations for polarized maser radiation and bears on the structure of accretion disks.Comment: Latex, uses aastex, eucal, to be published in the Astrophysical Journa

Patents from government-financed research and development

Data on numbers, sources, and kinds of patented inventions from government financed research and developmen

Microstructural evolution and solidification behavior of Al-Mg-Si alloy in high-pressure die casting

Copyright @ 2013 ASM International. This paper was published in Metallurgical and Materials Transactions A, 44A(7), 3185 - 3197 and is made available as an electronic reprint with the permission of ASM International. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplications of any material in this paper for a fee or for commercial purposes, or modification of the content of this paper are prohibited.Microstructural evolution and solidification behavior of Al-5 wt pct Mg-1.5 wt pct Si-0.6 wt pct Mn-0.2 wt pct Ti alloy have been investigated using high-pressure die casting. Solidification commences with the formation of primary a-Al phase in the shot sleeve and is completed in the die cavity. The average size of dendrites and fragmented dendrites of the primary a-Al phase formed in the shot sleeve is 43 lm, and the globular primary a-Al grains formed inside the die cavity is at a size of 7.5 lm. Solidification inside the die cavity also forms the lamellar Al-Mg2Si eutectic phase and the Fe-rich intermetallics. The size of the eutectic cells is about 10 lm, in which the lamellar a-Al phase is 0.41 lm thick. The Fe-rich intermetallic compound exhibits a compact morphology and is less than 2 lm with a composition of 1.62 at. pct Si, 3.94 at. pct Fe, and 2.31 at. pct Mn. A solute-enriched circular band is always observed parallel to the surface of the casting. The band zone separates the outer skin region from the central region of the casting. The solute concentration is consistent in the skin region and shows a general drop toward the center inside the band for Mg and Si. The peak of the solute enrichment in the band zone is much higher than the nominal composition of the alloy. The die casting exhibits a combination of brittle and ductile fracture. There is no significant difference on the fracture morphology in the three regions. The band zone is not significantly detrimental in terms of the fracture mechanism in the die casting. Calculations using the Mullins and Sekerka stability criterion reveal that the solidification of the primary a-Al phase inside the die cavity has been completed before the spherical a-Al globules begin to lose their stability, but the a-Al grains formed in the shot sleeve exceed the limit of spherical growth and therefore exhibit a dendritic morphologyEPSRC and JL