Fabrication and repair of graphite/epoxy laminates

New forming and patching methods have been developed for high-quality graphite/epoxy laminates. Laminates range in thickness from 0.012 to 0.018 in. (0.31 to 0.46 mm)

America's Veterans: A Sound Investment

In this report, the authors argue that society should leverage the latest generation of men and women leaving the military, and the skills, expertise and experience they bring to the civilian workforce. The authors examine the employment challenges facing the nation's nearly 2.6 million post-9/11 combat veterans as they transition to civilian jobs. They note that recent veterans "have struggled with unemployment rates that exceed the national average" despite recent survey findings that showed "most managers felt that military veterans were "better" or "much better" than civilians in areas such as teamwork, reliability, openness to other cultures and races, and work ethic." General Caldwell and Major Burke knock down several stereotypes about recent veterans and offer recommendations that business and government can undertake to help veterans successfully navigate the civilian labor market

High Voltage CMOS Control Interface for Astronomy - Grade Charged Coupled Devices

The Pan-STARRS telescope consists of an array of smaller mirrors viewed by a Gigapixel arrays of CCDs. These focal planes employ Orthogonal Transfer CCDs (OTCCDs) to allow on-chip image stabilization. Each OTCCD has advanced logic features that are controlled externally. A CMOS Interface Device for High Voltage has been developed to provide the appropiate voltage signal levels from a readout and control system designated STARGRASP. OTCCD chip output levels range from -3.3V to 16.7V, with two different output drive strenghts required depending on load capacitance (50pF and 1000pF), with 24mA of drive and a rise time on the order of 100ns. Additional testing ADC structures have been included in this chip to evaluate future functional additions for a next version of the chip.Comment: 13 pages, 17 gigure

Exoskeleton master controller with force-reflecting telepresence

A thorough understanding of the requirements for successful master-slave robotic systems is becoming increasingly desirable. Such systems can aid in the accomplishment of tasks that are hazardous or inaccessible to humans. Although a history of use has proven master-slave systems to be viable, system requirements and the impact of specifications on the human factors side of system performance are not well known. In support of the next phase of teleoperation research being conducted at the Armstrong Research Laboratory, a force-reflecting, seven degree of freedom exoskeleton for master-slave teleoperation has been concepted, and is presently being developed. The exoskeleton has a unique kinematic structure that complements the structure of the human arm. It provides a natural means for teleoperating a dexterous, possibly redundant manipulator. It allows ease of use without operator fatigue and faithfully follows human arm and wrist motions. Reflected forces and moments are remotely transmitted to the operator hand grip using a cable transmission scheme. This paper presents the exoskeleton concept and development results to date. Conceptual design, hardware, algorithms, computer architecture, and software are covered

Half-Life of 14^{14}O

We have measured the half-life of $^{14}$O, a superallowed $(0^{+} \to 0^{+})$ $\beta$ decay isotope. The $^{14}$O was produced by the $^{12}$C($^{3}$He,n)$^{14}$O reaction using a carbon aerogel target. A low-energy ion beam of $^{14}$O was mass separated and implanted in a thin beryllium foil. The beta particles were counted with plastic scintillator detectors. We find $t_{1/2} = 70.696\pm 0.052$ s. This result is $1.5\sigma$ higher than an average value from six earlier experiments, but agrees more closely with the most recent previous measurement.Comment: 10 pages, 5 figure

Confinement effects in a guided-wave interferometer with millimeter-scale arm separation

Guided-wave atom interferometers measure interference effects using atoms held in a confining potential. In one common implementation, the confinement is primarily two-dimensional, and the atoms move along the nearly free dimension under the influence of an off-resonant standing wave laser beam. In this configuration, residual confinement along the nominally free axis can introduce a phase gradient to the atoms that limits the arm separation of the interferometer. We experimentally investigate this effect in detail, and show that it can be alleviated by having the atoms undergo a more symmetric motion in the guide. This can be achieved by either using additional laser pulses or by allowing the atoms to freely oscillate in the potential. Using these techniques, we demonstrate interferometer measurement times up to 72 ms and arm separations up to 0.42 mm with a well controlled phase, or times of 0.91 s and separations of 1.7 mm with an uncontrolled phase.Comment: 14 pages, 6 figure

Results of soil moisture flights during April 1974

The results presented here are derived from measurements made during the April 5 and 6, 1974 flights of the NASA P-3A aircraft over the Phoenix, Arizona agricultural test site. The purpose of the mission was to study the use of microwave techniques for the remote sensing of soil moisture. These results include infrared (10-to 12 micrometers) 2.8-cm and 21-cm brightness temperatures for approximately 90 bare fields. These brightness temperatures are compared with surface measurements of the soil moisture made at the time of the overflights. These data indicate that the combination of the sum and difference of the vertically and the horizontally polarized brightness temperatures yield information on both the soil moisture and surface roughness conditions

Ions in solution: Density Corrected Density Functional Theory (DC-DFT)

Standard density functional approximations often give questionable results for odd-electron radical complexes, with the error typically attributed to self-interaction. In density corrected density functional theory (DC-DFT), certain classes of density functional theory calculations are significantly improved by using densities more accurate than the self-consistent densities. We discuss how to identify such cases, and how DC-DFT applies more generally. To illustrate, we calculate potential energy surfaces of HO$\cdot$Cl$^-$ and HO$\cdot$H$_2$O complexes using various common approximate functionals, with and without this density correction. Commonly used approximations yield wrongly shaped surfaces and/or incorrect minima when calculated self consistently, while yielding almost identical shapes and minima when density corrected. This improvement is retained even in the presence of implicit solvent

R-matrix Floquet theory for laser-assisted electron-atom scattering

A new version of the R-matrix Floquet theory for laser-assisted electron-atom scattering is presented. The theory is non-perturbative and applicable to a non-relativistic many-electron atom or ion in a homogeneous linearly polarized field. It is based on the use of channel functions built from field-dressed target states, which greatly simplifies the general formalism.Comment: 18 pages, LaTeX2e, submitted to J.Phys.