22 research outputs found

    SBIR Technology Applications to Space Communications and Navigation (SCaN)

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    This slide presentation reviews the mission of the Space Communications and Navigation (SCaN) Office with particular emphasis on opportunities for technology development with SBIR companies. The SCaN office manages NASA's space communications and navigation networks: the Near Earth Network (NEN), the Space Network (SN), and the Deep Space Network (DSN). The SCaN networks nodes are shown on a world wide map and the networks are described. Two types of technologies are described: Pull technology, and Push technologies. A listing of technology themes is presented, with a discussion on Software defined Radios, Optical Communications Technology, and Lunar Lasercom Space Terminal (LLST). Other technologies that are being investigated are some Game Changing Technologies (GCT) i.e., technologies that offer the potential for improving comm. or nav. performance to the point that radical new mission objectives are possible, such as Superconducting Quantum Interference Filters, Silicon Nanowire Optical Detectors, and Auto-Configuring Cognitive Communication

    SUPPLEMENTARY TECHNICAL BASIS FOR ASME SECTION XI CODE CASE N-597-2

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    ABSTRACT Section XI of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code provides rules and requirements for maintaining pressure boundary integrity of components, piping, and equipment during the life of a nuclear power plant. Code Case N-597-2 of Section XI, Requirements for Analytical Evaluation of Pipe Wall Thinning, provides evaluation procedures and acceptance criteria to justify continued operation of Class 1, 2 and 3 piping items subjected to wall thinning by a mechanism such as flow-accelerated corrosion. The acceptance criteria ensure that margins equivalent to those of the ASME B&PV Code are maintained. The technical basis for Code Case N-597-2 was previously presented at the 1999 ASME Pressure Vessels and Piping Conference. Since then, the ASME Section XI Working Group on Pipe Flaw Evaluation has identified the need for further explanation of the technical basis for the Code Case, such as the procedures for evaluation of wall thickness less than the Construction Code Design Pressure-based minimum allowable wall thickness, t min . This paper provides an additional description of the Code Case technical basis and validation against experimental and historic wall thinning events. NOMENCLATURE a = depth of an axial flaw A = reinforcement area required for a Class 1 pipe under internal pressure in accordance with rules in Section III of the ASME B&PV Code A i = predicted inside area of the cross-section of the pipe A o = total cross-sectional area of the pipe based on nominal outside diameter A p = predicted metal cross-sectional area of the pipe A rein = reinforcement area required for a Class 2 or 3 pipe under internal pressure in accordance with rules in Section III of the ASME B&PV Code B = parameter used to calculate maximum allowable length of an axial flaw in ANSI/ASME B31G d = distance from the center of a local thinned area defining the limits of reinforcement for Class 2 and 3 piping in accordance with the Construction Code D o = nominal outside diameter of the piping item f = stress range reduction factor for cyclic conditions for Class 2 and 3 piping i = stress intensification factor for Class 2 and 3 piping i 0 = stress intensification factor based on the design-basis geometry of the piping item k = constant used to describe the assumed linear increase in stress intensification factor i L = maximum extent of a local thinned area with t p < t nom L A = distance used to define limits of reinforcement for Class 1 piping in accordance with rules in Section III of the ASME B&PV Code L ax = maximum allowable length of an axial flaw from ANSI/ASME B31G L m = maximum extent of a local thinned area with t p < t min L m(a) = axial extent of a local thinned area with t p < t min L m(t) = transverse (circumferential) extent of a local thinned area with t p < t min M b = bending moment n = number of load cycles N = number of allowable load cycles N' = number of allowable load cycles corresponding to an assumed linear increase in stress intensification factor i N 0 = number of allowable load cycles based on the as-installed geometry of the piping item P = Design Pressure R = mean radius of the piping item based on nominal outside radius and nominal wall thickness R min = mean radius of the piping item based on nominal outside radius and t min s = stress range due to cyclic loading s 0 = stress range due to cyclic loading based on the design basis geometry of the piping item 1 Copyright © 2006 by ASME = predicted distribution of wall thickness at the end of the evaluation period t p,min = minimum predicted wall thickness at the end of the evaluation period y = factor required by the applicable piping Construction Code in the calculation of t min , and is equal to 0.4 Z min = predicted minimum section modulus of the thinned section of pipe δ = nominal distance between the center of the pipe and the neutral axis of the thinned pipe section σ

    Archeological Investigations at the Santa Maria Creek Site (41CW104) Caldwell County, Texas

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    The excavations by Atkins at the Santa Maria Creek site (41CW104) described in the following report have succeeded in bringing together a myriad of information regarding aboriginal occupations in eastern Central Texas at the dawn of the Historic period. The analysis of the materials recovered from National Register of Historic Places testing and data recovery has demonstrated that even a site buried in sandy, bioturbated sediments can still significantly add to the archeological record. This becomes even more important for areas such as Caldwell County, Texas, which have witnessed few such investigations. The report utilized a wide array of analytical techniques to unravel the site, including extensive ethnohistorical research, artifact analysis, special studies, and experimental archeology

    Effects of 12 Months of Vagus Nerve Stimulation in Treatment-Resistant Depression: A Naturalistic Study

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    Background: The need for effective, long-term treatment for recurrent or chronic, treatment-resistant depression is well established. Methods: This naturalistic follow-up describes outpatients with nonpsychotic major depressive (n = 185) or bipolar (I or II) disorder, depressed phase (n = 20) who initially received 10 weeks of active (n = 110) or sham vagus nerve stimulation (VNS) (n = 95). The initial active group received another 9 months, while the initial sham group received 12 months of VNS. Participants received antidepressant treatments and VNS, both of which could be adjusted. Results: The primary analysis (repeated measures linear regression) revealed a significant reduction in 24-item Hamilton Rating Scale for Depression (HRSD24) scores (average improvement, .45 points [SE = .05] per month (p \u3c .001). At exit, HRSD24 response rate was 27.2% (55/202); remission rate (HRSD24 ≤ 9) was 15.8% (32/202). Montgomery Asberg Depression Rating Scale (28.2% [57/202]) and Clinical Global Impression-Improvement (34.0% [68/200]) showed similar response rates. Voice alteration, dyspnea, and neck pain were the most frequently reported adverse events. Conclusions: These 1-year open trial data found VNS to be well tolerated, suggesting a potential long-term, growing benefit in treatment-resistant depression, albeit in the context of changes in depression treatments. Comparative long-term data are needed to determine whether these benefits can be attributed to VNS

    Effects of 12 Months of Vagus Nerve Stimulation in Treatment-Resistant Depression: A Naturalistic Study

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    Background: The need for effective, long-term treatment for recurrent or chronic, treatment-resistant depression is well established. Methods: This naturalistic follow-up describes outpatients with nonpsychotic major depressive (n = 185) or bipolar (I or II) disorder, depressed phase (n = 20) who initially received 10 weeks of active (n = 110) or sham vagus nerve stimulation (VNS) (n = 95). The initial active group received another 9 months, while the initial sham group received 12 months of VNS. Participants received antidepressant treatments and VNS, both of which could be adjusted. Results: The primary analysis (repeated measures linear regression) revealed a significant reduction in 24-item Hamilton Rating Scale for Depression (HRSD24) scores (average improvement, .45 points [SE = .05] per month (p \u3c .001). At exit, HRSD24 response rate was 27.2% (55/202); remission rate (HRSD24 ≤ 9) was 15.8% (32/202). Montgomery Asberg Depression Rating Scale (28.2% [57/202]) and Clinical Global Impression-Improvement (34.0% [68/200]) showed similar response rates. Voice alteration, dyspnea, and neck pain were the most frequently reported adverse events. Conclusions: These 1-year open trial data found VNS to be well tolerated, suggesting a potential long-term, growing benefit in treatment-resistant depression, albeit in the context of changes in depression treatments. Comparative long-term data are needed to determine whether these benefits can be attributed to VNS

    Cross-Disorder Genomewide Analysis of Schizophrenia, Bipolar Disorder, and Depression

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    Family and twin studies indicate substantial overlap of genetic influences on psychotic and mood disorders. Linkage and candidate gene studies have also suggested overlap across schizophrenia (SCZ), bipolar disorder (BPD), and major depressive disorder (MDD). The objective of this study was to apply genomewide association study (GWAS) analysis to address the specificity of genetic effects on these disorders

    Archeological Investigations at the Santa Maria Creek Site (41CW104) Caldwell County, Texas

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    Report on the excavations at the Santa Maria creek site in Caldwell County, Texas during 2006 and 2007. The report includes a discussion of research methods, analysis of the findings, and history of the area
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