Improved calorimeter provides accurate thermal measurements of space batteries

Isothermal continuous flow calorimeter measures the thermal characteristics of space batteries undergoing typical orbital cycling. This is 28 times as sensitive as calorimeters previously used

Experimental L-band SST satellite communications/surveillance terminal study. Volume 1 - Study summary

Study of design for experimental L band supersonic transport communications/surveillance termina

Research into fundamental phenomena associated with spacecraft electrochemical devices - calorimetry of nickel-cadmium cells Progress report, 1 Oct. 1966 - 31 Dec. 1966

Cycling, charge efficiency, and transducer studies with nickel-cadmium cell for spacecraft power supply system

Experimental L-band SST satellite communications/surveillance terminal study. Volume 5 - Aircraft terminal definition

Aircraft terminal designs for experimental and operational supersonic transport for L band satellite air traffic contro

Effect of GPS Feedback on Lactate Threshold Pacing in Intercollegiate Distance Runners

International Journal of Exercise Science 6(1) : 74-80, 2013. In their roles as coaches, the authors have observed that first-year collegiate distance runners often have difficulty running at prescribed training paces during lactate threshold (LT) training runs. Previous research has validated the accuracy of global positioning system (GPS) devices in providing distance and velocity feedback during running. The purpose of this study was to determine the efficacy of using the Garmin Forerunner 305 GPS watch (Garmin) to reduce deviations from prescribed training paces during LT runs with first-year collegiate runners. Participants were two groups of varsity cross country runners who completed a three-week LT training intervention either with (n = 5) or without (n = 6) a Garmin device. Prescribed training paces were based off an initial time-trial. In both the pre- and post-test runs, in which all runners ran without a Garmin device, differences were calculated between the prescribed pace and actual pace. The comparisons revealed a significant difference between the training groups in the post-test. Those runners who trained with the Garmin device had a significant decrease in pacing variability. This suggests that GPS pacing feedback appears to be an effective tool at improving LT pacing in first-year collegiate distance runners

Dipolar and scalar 3^3He and 129^{129}Xe frequency shifts in mm-sized cells

We describe a $^{3}$He-$^{129}$Xe comagnetometer operating in stemless anodically bonded cells with a 6 mm$^3$ volume and a $^{129}$Xe spin coherence time of 300 sec. We use a $^{87}$Rb pulse-train magnetometer with co-linear pump and probe beams to study the nuclear spin frequency shifts caused by spin polarization of $^{3}$He. By systematically varying the cell geometry in a batch cell fabrication process we can separately measure the cell shape dependent and independent frequency shifts. We find that a certain aspect ratio of the cylindrical cell can cancel the effects of $^3$He magnetization that limit the stability of vapor-cell comagnetometers. Using this control we also observe for the first time a scalar $^{3}$He-$^{129}$Xe collisional frequency shift characterized by an enhancement factor $\kappa_{\text{HeXe}} = -0.011\pm0.001$.Comment: 4 pages, 4 figure

Accuracy of Voice-Announcement Pedometers for Youth with Visual Impairment

Thirty-five youth with visual impairments (13.5 plus or minus 2.1 yrs, 13 girls and 22 boys) walked four 100-meter distances while wearing two units (right and left placement) of three brands of voice-announcement (VA) pedometers (Centrios[TM] Talking Pedometer, TALKiNG Pedometer, and Sportline Talking Calorie Pedometer 343) and a reference pedometer (NL2000). Registered pedometer steps for each trial were recorded, compared to actual steps assessed via digital video. Inter-unit agreement between right and left VA pedometer placement was low (ICC range 0.37 to 0.76). A systematic error was observed for the VA pedometers on the left placement (error range 5.6% to 12.2%), while right placement VA pedometers were at or below plus or minus 3% from actual steps (range 2.1% to 3.3%). The reference pedometer was unaffected by placement (ICC 0.98, error approximately 1.4%). Overall, VA pedometers demonstrated acceptable accuracy for the right placement, suggesting this position is necessary for youth with visual impairments. (Contains 3 tables and 2 figures.

The Core of the Participatory Budgeting Problem

In participatory budgeting, communities collectively decide on the allocation of public tax dollars for local public projects. In this work, we consider the question of fairly aggregating the preferences of community members to determine an allocation of funds to projects. This problem is different from standard fair resource allocation because of public goods: The allocated goods benefit all users simultaneously. Fairness is crucial in participatory decision making, since generating equitable outcomes is an important goal of these processes. We argue that the classic game theoretic notion of core captures fairness in the setting. To compute the core, we first develop a novel characterization of a public goods market equilibrium called the Lindahl equilibrium, which is always a core solution. We then provide the first (to our knowledge) polynomial time algorithm for computing such an equilibrium for a broad set of utility functions; our algorithm also generalizes (in a non-trivial way) the well-known concept of proportional fairness. We use our theoretical insights to perform experiments on real participatory budgeting voting data. We empirically show that the core can be efficiently computed for utility functions that naturally model our practical setting, and examine the relation of the core with the familiar welfare objective. Finally, we address concerns of incentives and mechanism design by developing a randomized approximately dominant-strategy truthful mechanism building on the exponential mechanism from differential privacy

Ligament Tissue Engineering and Its Potential Role in Anterior Cruciate Ligament Reconstruction

Tissue engineering is an emerging discipline that combines the principle of science and engineering. It offers an unlimited source of natural tissue substitutes and by using appropriate cells, biomimetic scaffolds, and advanced bioreactors, it is possible that tissue engineering could be implemented in the repair and regeneration of tissue such as bone, cartilage, tendon, and ligament. Whilst repair and regeneration of ligament tissue has been demonstrated in animal studies, further research is needed to improve the biomechanical properties of the engineered ligament if it is to play an important part in the future of human ligament reconstruction surgery. We evaluate the current literature on ligament tissue engineering and its role in anterior cruciate ligament reconstruction