Blood volume changes

Analysis of radionuclide volume determinations made for the crewmembers of selected Gemini and Apollo missions showed that orbital spaceflight has an effect on red cell mass. Because the methods and the protocol developed for earlier flights were used for the crews of the three Skylab missions, direct comparisons are possible. After each Skylab mission, decreases were found in crewmembers' red cell masses. The mean red cell mass decrease of 11 percent or 232 milliliters was approximately equal to the 10 percent mean red cell mass decrease of the Apollo 14 to 17 crewmembers. The red cell mass drop was greatest and the postrecovery reticulocyte response least for crewmembers of the 28-day Skylab 2 mission. Analyses of data from the red cell mass determinations indicate that the red cell mass drops occurred in the first 30 days of flight and that a gradual recovery of the red cell mass deficits began approximately 60 days after launch. The beginning of red cell mass regeneration during the Skylab 4 flight may explain the higher postmission reticulocyte counts

Strong Pinning Enhancement in MgB2 Using Very Small Dy2O3 Additions

0.5 to 5.0 wt.% Dy2O3 was in-situ reacted with Mg + B to form pinned MgB2. While Tc remained largely unchanged, Jc was strongly enhanced. The best sample (only 0.5 wt.% Dy2O3) had a Jc of 6.5 x 10^5 A/cm^2 at 6K, 1T and 3.5 x 10^5 A/cm^2 at 20K, 1T, around a factor of 4 higher compared to the pure sample, and equivalent to hot-pressed or nano-Si added MgB2 at below 1T. Even distributions of nano-scale precipitates of DyB4 and MgO were observed within the grains. The room temperature resistivity decreased with Dy2O3 indicative of improved grain connectivity.Comment: 13 pages, 4 figures and 1 tabl

Improved Current Densities in MgB2 By Liquid-Assisted Sintering

Polycrystalline MgB2 samples with GaN additions were prepared by reaction of Mg, B, and GaN powders. The presence of Ga leads to a low melting eutectic phase which allowed liquid phase sintering and produces plate-like grains. For low-level GaN additions (5% at. % or less), the critical transition temperature, Tc, remained unchanged and in 1T magnetic field, the critical current density, Jc was enhanced by a factor of 2 and 10, for temperatures of \~5K and 20K, respectively. The values obtained are approaching those of hot isostatically pressed samples.Comment: 12 pages, 1 table, 4 figures, accepted in Applied Physics Letter

Languages and Learning at Key Stage 2: A Longitudinal Study Final Report

In 2006, The Open University, the University of Southampton and Canterbury Christ Church University were commissioned by the then Department for Education and Skills (DfES), now Department for Children, Schools and Families (DCSF) to conduct a three-year longitudinal study of languages learning at Key Stage 2 (KS2). The qualitative study was designed to explore provision, practice and developments over three school years between 2006/07 and 2008/09 in a sample of primary schools and explore children’s achievement in oracy and literacy, as well as the possible broader cross-curricular impact of languages learning

Chaotic memristor

We suggest and experimentally demonstrate a chaotic memory resistor (memristor). The core of our approach is to use a resistive system whose equations of motion for its internal state variables are similar to those describing a particle in a multi-well potential. Using a memristor emulator, the chaotic memristor is realized and its chaotic properties are measured. A Poincar\'{e} plot showing chaos is presented for a simple nonautonomous circuit involving only a voltage source directly connected in series to a memristor and a standard resistor. We also explore theoretically some details of this system, plotting the attractor and calculating Lyapunov exponents. The multi-well potential used resembles that of many nanoscale memristive devices, suggesting the possibility of chaotic dynamics in other existing memristive systems.Comment: Applied Physics A (in press

Mercury mobilization and episodic stream acidification during snowmelt: Role of hydrologic flow paths, source areas, and supply of dissolved organic carbon

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95317/1/wrcr11826.pd

Two-subband quantum Hall effect in parabolic quantum wells

The low-temperature magnetoresistance of parabolic quantum wells displays pronounced minima between integer filling factors. Concomitantly the Hall effect exhibits overshoots and plateau-like features next to well-defined ordinary quantum Hall plateaus. These effects set in with the occupation of the second subband. We discuss our observations in the context of single-particle Landau fan charts of a two-subband system empirically extended by a density dependent subband separation and an enhanced spin-splitting g*.Comment: 5 pages, submitte

Counting statistics and super-Poissonian noise in a quantum dot

We present time-resolved measurements of electron transport through a quantum dot. The measurements were performed using a nearby quantum point contact as a charge detector. The rates for tunneling through the two barriers connecting the dot to source and drain contacts could be determined individually. In the high bias regime, the method was used to probe excited states of the dot. Furthermore, we have detected bunching of electrons, leading to super-Poissonian noise. We have used the framework of the full counting statistics (FCS) to model the experimental data. The existence of super-Poissonian noise suggests a long relaxation time for the involved excited state, which could be related to the spin relaxation time

Legacy mercury and stoichiometry with C, N, and S in soil, pore water, and stream water across the upland‐wetland interface: The influence of hydrogeologic setting

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/99104/1/2012JG002250R_Appendix_C_120728.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99104/2/jgrg20066.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99104/3/2012JG002250R_Appendix_B_100903.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99104/4/2012JG002250R_Appendix_A_100907.pd