Dynamic characteristics of a space-station solar wing array

A solar-wing-array concept is described which meets space-station requirements for minimum fundamental frequency (0.4 Hz), component modularity, and growth potential. The basic wing-array design parameters are varied, and the resulting effects on the array vibration frequencies and mode shapes are assessed. The transient response of a free-free space station (incorporating a solar-wing-array point design) to a load applied at the space-station center is studied. The use of the transient response studies in identifying critically loaded structural members is briefly discussed. The final 150-kW space-station configuration has a fundamental elastic frequency of 0.403 Hz

Structural design of an in-line bolted joint for the space shuttle solid rocket motor case segments

Results of a structural design study of an in-line bolted joint concept which can be used to assemble Space Shuttle Solid Rocket Motor (SRM) case segments are presented. Numerous parametric studies are performed to characterize the in-line bolted joint behavior as major design variables are altered, with the primary objective always being to keep the inside of the joint (where the O-rings are located) closed during the SRM firing. The resulting design has 180 1-inch studs, an eccentricity of -0.5 inch, a flange thickness of 3/4 inch, a bearing plate thickness of 1/4 inch, and the studs are subjected to a preload which is 70% of ultimate. The mass penalty per case segment joint for the in-line design is 346 lbm more than the weight penalty for the proposed capture tang fix

Lightweight structural design of a bolted case joint for the space shuttle solid rocket motor

The structural design of a bolted joint with a static face seal which can be used to join Space Shuttle Solid Rocket Motor (SRM) case segments is given. Results from numerous finite element parametric studies indicate that the bolted joint meets the design requirement of preventing joint opening at the O-ring locations during SRM pressurization. A final design recommended for further development has the following parameters: 180 one-in.-diam. studs, stud centerline offset of 0.5 in radially inward from the shell wall center line, flange thickness of 0.75 in, bearing plate thickness of 0.25 in, studs prestressed to 70 percent of ultimate load, and the intermediate alcove. The design has a mass penalty of 1096 lbm, which is 164 lbm greater than the currently proposed capture tang redesign

Amputation on Account of Enlargement of the Knee-Joint

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Effect of wind turbine generator model and siting on wind power changes out of large WECS arrays

Methods of reducing the WECS generation change through selection of the wind turbine model for each site, selection of an appropriate siting configuration, and wind array controls are discussed. An analysis of wind generation change from an echelon and a farm for passage of a thunderstorm is presented. Reduction of the wind generation change over ten minutes is shown to reduce the increase in spinning reserve, unloadable generation and load following requirements on unit commitment when significant WECS generation is present and the farm penetration constraint is satisfied. Controls on the blade pitch angle of all wind turbines in an array or a battery control are shown to reduce both the wind generation change out of an array and the effective farm penetration in anticipation of a storm so that the farm penetration constraint may be satisfied

Facts about Fowl Cholera

Fowl cholera is a specific infectious disease which affects nearly all species of poultry. Quite frequently it occurs as an acute disease, but sub-acute and chronic infections are also common. It is one of the oldest of the poultry diseases, the infectious nature having been recognized for a century. Fowl cholera was first reported in the United States in 1880. From that time to the present the disease has accounted for an enormous loss of poultry. It is not of equal importance in all parts of the country. In some areas cholera occurs only sporadically; other areas show a decline in numbers of outbreaks as compared to· 15 to 20 years ago. This decline may be due, in part, to better poultry management practices. In other areas fowl cholera is prevalent every year, affecting many flocks and accounting for a high mortality. (See more in text

The Effect of Magnetization upon the Elasticity of Rods

In the Physical Review, Vol. II, No. 4 and Vol. III., No. 6, is described a series of important experiments which show the relation between temperature and elasticity in wire. In one of the papers the statement was made that the results seem to indicate that the magnetizing effect of the current through the wire increases the modulus of elasticity. The increase in temperature in the wire was produced by sending a current directly through it, and also by sending a current through the helix that surrounded it. The author stated that the magnetization produced by the first method had no appreciable effect on the result, and that if there is any difference in the effects produced upon the elasticity of a wire by magnetizing it, that difference is too small to be detected with any certainty by this experiment. This paper contains the results of some experiments whose object was to test the effect of magnetization upon the modulus of elasticity by the application of interference methods of measurement

Design and Rationale of the Cognitive Intervention to Improve Memory in Heart Failure Patients Study

BACKGROUND: Memory loss is an independent predictor of mortality among heart failure patients. Twenty-three percent to 50% of heart failure patients have comorbid memory loss, but few interventions are available to treat the memory loss. The aims of this 3-arm randomized controlled trial were to (1) evaluate efficacy of computerized cognitive training intervention using BrainHQ to improve primary outcomes of memory and serum brain-derived neurotrophic factor levels and secondary outcomes of working memory, instrumental activities of daily living, and health-related quality of life among heart failure patients; (2) evaluate incremental cost-effectiveness of BrainHQ; and (3) examine depressive symptoms and genomic moderators of BrainHQ effect. METHODS: A sample of 264 heart failure patients within 4 equal-sized blocks (normal/low baseline cognitive function and gender) will be randomly assigned to (1) BrainHQ, (2) active control computer-based crossword puzzles, and (3) usual care control groups. BrainHQ is an 8-week, 40-hour program individualized to each patient's performance. Data collection will be completed at baseline and at 10 weeks and 4 and 8 months. Descriptive statistics, mixed model analyses, and cost-utility analysis using intent-to-treat approach will be computed. CONCLUSIONS: This research will provide new knowledge about the efficacy of BrainHQ to improve memory and increase serum brain-derived neurotrophic factor levels in heart failure. If efficacious, the intervention will provide a new therapeutic approach that is easy to disseminate to treat a serious comorbid condition of heart failure

Structure and morphology of an active conjugate relay zone, Messina Strait, southern Italy

Messina Strait is a narrow fault-bounded marine basin that separates the Calabrian peninsula from Sicily in southern Italy. It sits in a seismically active region where normal fault scarps and raised Quaternary marine terraces record ongoing extension driven by southeastward rollback of the Calabrian subduction zone. A review of published studies and new data shows that normal faults in the Messina Strait region define a conjugate relay zone where displacement is transferred along strike from NW-dipping normal faults in the northeast (southern Calabria) to the SE-dipping Messina-Taormina normal fault in the southwest (offshore eastern Sicily). The narrow marine strait is a graben undergoing active subsidence within the relay zone, where pronounced curvature of normal faults results from large strain gradients and clockwise rotations related to fault interactions. Based on regional fault geometries and published age constraints, we infer that normal faults in southern Calabria migrated northwest while normal faults in NE Sicily migrated southeast during the past ca. 2–2.5 Myr. This pattern has resulted in tectonic narrowing of the strait through time by inward migration of facing normal faults and rapid mantle-driven uplift

In vivo evidence that truncated trkB.T1 participates in nociception

Brain-Derived Neurotrophic Factor (BDNF) is a central nervous system modulator of nociception. In animal models of chronic pain, BDNF exerts its effects on nociceptive processing by binding to the full-length receptor tropomyosin-related kinase B (trkB.FL) and transducing intracellular signaling to produce nocifensive behaviors. In addition to trkB.FL, the trkB locus also produces a widely-expressed alternatively-spliced truncated isoform, trkB.T1. TrkB.T1 binds BDNF with high affinity; however the unique 11 amino acid intracellular cytoplasmic tail lacks the kinase domain of trkB.FL. Recently, trkB.T1 was shown to be specifically up-regulated in a model of HIV-associated neuropathic pain, potentially implicating trkB.T1 as a modulator of nociception. Here, we report that trkB.T1 mRNA and protein is up-regulated in the spinal dorsal horn at times following antiretroviral drug treatment and hind paw inflammation in which nocifensive behaviors develop. While genetic depletion of trkB.T1 did not affect baseline mechanical and thermal thresholds, the absence of trkB.T1 resulted in significant attenuation of inflammation- and antiretroviral-induced nocifensive behaviors. Our results suggest that trkB.T1 up-regulation following antiretroviral treatment and tissue inflammation participates in the development and maintenance of nocifensive behavior and may represent a novel therapeutic target for pain treatment