Thermal emittance enhancement of graphite-copper composites for high temperature space based radiators

Graphite-copper composites are candidate materials for space based radiators. The thermal emittance of this material, however, is a factor of two lower than the desired emittance for these systems of greater than or equal to 0.85. Arc texturing was investigated as a surface modification technique for enhancing the emittance of the composite. Since the outer surface of the composite is copper, and samples of the composite could not be readily obtained for testing, copper was used for optimization testing. Samples were exposed to various frequencies and currents of arcs during texturing. Emittances near the desired goal were achieved at frequencies less than 500 Hz. Arc current did not appear to play a major role under 15 amps. Particulate carbon was observed on the surface, and was easily removed by vibration and handling. In order to determine morphology adherence, ultrasonic cleaning was used to remove the loosely adherent material. This reduced the emittance significantly. Emittance was found to increase with increasing frequency for the cleaned samples up to 500 Hz. The highest emittance achieved on these samples over the temperature range of interest was 0.5 to 0.6, which is approximately a factor of 25 increase over the untextured copper emittance

Dynamic range and mass accuracy of wide-scan direct infusion nanoelectrospray fourier transform ion cyclotron resonance mass spectrometry-based metabolomics increased by the spectral stitching method

Direct infusion nanoelectrospray Fourier transform ion cyclotron resonance mass spectrometry (DI nESI FT-ICR MS)offers high mass accuracy and resolution for analyzing complex metabolite mixtures. High dynamic range across a wide mass range, however, can only be achieved at the expense of mass accuracy, since the large numbers of ions entering the ICR detector induce adverse spacecharge effects. Here we report an optimized strategy for wide-scan DI nESI FT-ICR MS that increases dynamic range but maintains high mass accuracy. It comprises the collection if multiple adjacent selected ion monitoring (SIM) windows that are stitched together using novel algorithms. The final SIM-stitching method, derived from several optimization experiments, comprises 21 adjoining SIM windows each of width m/z 30 (from m/z 70 to 500; adjacent windows overlap by m/z 10) with an automated gain control (AGC) target of 1 105 charges. SIMstitching and wide-scan range (WSR; Thermo Electron)were compared using a defined standard to assess mass accuracy and a liver extract to assess peak count and dynamic range. SIM-stitching decreased the maximum mass error by 1.3- and 4.3-fold, and increased the peak count by 5.3- and 1.8-fold, versus WSR (AGC targets of 1 x 105 and 5 x 105, respectively). SIM-stitching achieved an rms mass error of 0.18 ppm and detected over 3000 peaks in liver extract. This novel approach increases metabolome coverage, has very high mass accuracy, and at 5.5 min/sample is conducive for high- throughput metabolomics

Sequential comparison of tiotropium to high-dose ipratropium in patients with chronic obstructive pulmonary disease in a practice setting

Umair Gauhar, Mark Dransfield, J Allen D CooperPulmonary Section, Birmingham Veterans Affairs Medical Center and Division of Allergy, Pulmonary and Critical Medicine University of Alabama at Birmingham, AL, USAObjective: To determine the effect of changing anticholinergic therapy in patients with COPD from ipratropium to tiotropium on pulmonary function.Methods: We examined records of patients prescribed high-dose ipratropium, who were subsequently converted to tiotropium. Spirometric values were obtained within 2 days of the change in medication and after 56 to 224 days of the switch to tiotropium.Results: 15 subjects were documented to have filled a prescription for ipratropium-containing medications the month prior to the change. Medication compliance over the 6 months prior to the switch in these patients was 72% ± 31% (mean ± SD) for ipratropium compared to 87% ± 14% for tiotropium over the 6-month period after the switch (P = 0.1). FEV1 improved from 1.12 ± 0.39 L at baseline to 1.37 ± 0.49 L after the change to tiotropium (P = 0.01). FVC also improved from 2.45 ± 0.73 L at baseline to 2.72 ± 0.69 L after the change (P = 0.04). Maximal voluntary ventilation was also increased from 39.67 ± 10.7 L/min to 45.13 ± 15.8 L/min (P = 0.045).Conclusions: We conclude that replacing high-dose ipratropium with tiotropium therapy significantly improves pulmonary function in a clinical setting.Keywords: ipratropium, tiotropium, COPD, pulmonary function, exacerbation rat

Improved fidelity of triggered entangled photons from single quantum dots

We demonstrate the on-demand emission of polarisation-entangled photon pairs from the biexciton cascade of a single InAs quantum dot embedded in a GaAs/AlAs planar microcavity. Improvements in the sample design blue shifts the wetting layer to reduce the contribution of background light in the measurements. Results presented show that >70% of the detected photon pairs are entangled. The high fidelity of the (|HxxHx>+|VxxVx>)/2^0.5 state that we determine is sufficient to satisfy numerous tests for entanglement. The improved quality of entanglement represents a significant step towards the realisation of a practical quantum dot source compatible with applications in quantum information.Comment: 9 pages. Paper is available free of charge at http://www.iop.org/EJ/abstract/1367-2630/8/2/029/, see also 'A semiconductor source of triggered entangled photon pairs', R. M. Stevenson et al., Nature 439, 179 (2006

Great Lakes all-weather ice information system

A system is described which utilizes an X-band Side-Looking-Airborne-Radar (SLAR) for determining type, location, and aerial distribution of the ice cover in the Great Lakes and an airborne, S-band, short pulse radar for obtaining ice thickness. The SLAR system is currently mounted aboard a U.S. Coast Guard C-130B aircraft. Digitized SLAR data are relayed in real-time via the NOAA-GOES-1 satellite in geosynchronous orbit to the U.S. Coast Guard Ice Center in Cleveland, Ohio. SLAR images along with hand-drawn interpretative ice charts for various winter shipping areas in the Great Lakes are broadcast to facsimile recorders aboard Great Lakes vessels. The operational aspects of this ice information system are being demonstrated by NASA, U.S. Coast Guard, and NOAA/National Weather Service. Results from the 1974-75 winter season demonstrated the ability of this system to provide all-weather ice information to shippers in a timely manner

Life expectancy of persons receiving combination antiretroviral therapy in low-income countries: a cohort analysis from Uganda

Little is known about the effect of combination antiretroviral therapy (cART) on life expectancy in sub-Saharan Africa

Neuromuscular and Bounce Drop-Jump Responses to Different Inter-Repetition Rest Intervals during A Composite Training Session in Hurling Players

The purposes of this study were to a) compare a 4-min to an 8-min rest interval between composite training (jump-sprint combination) repetitions in a single session to allow for the recovery of neuromuscular and bounce drop-jump (BDJ) performance and b) investigate if super compensation would occur after 168hrs of rest. Twelve players were randomly assigned to either a 4-min or an 8-min rest interval group. Participants first completed a BDJ test to identify individual BDJ drop heights followed by a 20m sprint test. Seventy-two hours later, a composite training session of two repetitions (three BDJs followed by a 20m sprint after a 15s rest) with either a 4-min or an 8-min rest interval was performed. A three repetition maximum (3RM) back squat strength test, a BDJ, countermovement jump (CMJ) and a sprint performance test were completed 10-mins pre- and immediately post-session, and 168 hrs post-session. CMJ force (8-min group) and BDJ (height and reactive strength index (RSI)) measures decreased significantly post-session (4-min and 8-min groups; P ≤ 0.05). Pre-session to 168 hrs post-session, relative 3RM back squat strength and 20m sprint performance increased significantly for the 4-min group only (P ≤ 0.05). In conclusion, a 4-min composite training inter-repetition rest interval leads to a significant decline in BDJ measures (RSI and jump height) which may act as fatigue markers for monitoring. However, 4-mins provides sufficient recovery during the session which, in conjunction with 168 hrs of recovery, causes super compensation in neuromuscular performance in hurling players

The Reliability of Countermovement Jump Performance and the Reactive Strength Index in Identifying Drop-Jump Drop Height in Hurling Players

The purpose of this study was to estimate the inter-day reliability of countermovement jump performance (CMJ) and the reactive strength index (RSI) in identifying drop-jump drop height in male hurling players. Eighteen male hurling players volunteered to participate. Subjects performed the CMJ and drop-jump test for RSI during the same sessions on three separate occasions a minimum of 48 hours apart. Subjects performed three CMJs and two drop-jumps from five different heights in an incremental manner (0.20, 0.30, 0.40, 0.50, 0.60 m). The results displayed acceptable levels of relative and absolute reliability for the following CMJ measures: height, velocity, force, power and average eccentric rate of force development measures (RFD). Absolute and relative peak concentric rate of force development from the CMJ test were found to have low levels of absolute reliability due to high CV% values. RSI and identified drop height from the drop-jump test displayed acceptable reliability (ICC single measure = 0.88 and 0.92 respectively; CV% = 6% and 10% respectively). Furthermore, limits of agreement random error displayed acceptable reliability for CMJ and drop-jump measures from estimated feasible minimum a priori sample sizes based upon limits of agreement. In conclusion, CMJ force-time measures (excluding peak concentric RFD measures), RSI and the identified drop height have acceptable absolute and relative reliability. For the sport science practitioner involved in hurling and for hurling players, this means that the CMJ test is reliable for kinetic and kinematic variables and the drop-jump test provides a means of developing a reactive strength profile and a means of individualizing drop height for drop-jump training

Surgical Fixation of Complex Rib Fractures to Sternum for Flail Chest: A Case Report

Rib fractures are among the most common injuries found in a patient presenting from blunt trauma. They are associated with significant morbidity and mortality, largely due to pulmonary complications. Open reduction and internal fixation (ORIF) has been the mainstay treatment for patients with multiple rib fractures. In this report, we present a case of a patient that sustained blunt thoracic trauma with multiple anterolateral rib fractures, including a flail segment. This fail segment involved the costal cartilage and required fixation of ribs to the sternum in order to restore chest wall stabilization and integrity. This was achieved using the Zimmer Biomet rib plate system. The approach utilized should be considered in patients with rib fractures associated with segments of displaced costal cartilage