4,407 research outputs found
Thermoelectric properties of Bi2Sr2Co2O9 whiskers under hydrostatic pressure
We report the temperature dependence of thermopower (S) in the ab plane of Bi2Sr2Co2O9 {BC-222} single crystalline whiskers under high pressure up to 1.2 GPa. Special modifications were made to our high-pressure transport measurement system to improve the measurement accuracy of S for whiskers with high resistance. Pressure improved the contact resistance dramatically. We observed a slight decrease of S and four-wire electrical conductivity (sigma) under high pressure. As a result, the power factor (S2sigma) was decreased less than 20% by pressure. From the temperature dependence of sigma, the band gap of BC-222 whiskers increase very slightly under high pressure
Experiment definition phase shuttle laboratory (LDRL-10.6 experiment): Shuttle sortie to elliptical orbit satellite
The following topics were reviewed: (1) design options for shuttle terminal, (2) elliptical orbit satellite design options, (3) shuttle terminal details, (4) technology status and development requirements, (5) transmitter technology, and (6) carbon dioxide laser life studies
Parametric analysis of microwave and laser systems for communication and tracking. Volume 3 - Reference data for advanced space communication and tracking systems
Reference data for advanced microwave and laser communication and tracking systems - Vol.
Literacy skills of Australian Indigenous school children with and without otitis media and hearing loss
This study examined the relationship between reading, spelling, and the presence of otitis media (OM) and co-occurring hearing loss (HL) in metropolitan Indigenous Australian children, and compared their reading and spelling outcomes with those of their non-Indigenous peers. OM and HL may hinder language development and phonological awareness skills, but there is little empirical evidence to link OM/HL and literacy in this population. Eighty-six Indigenous and non-Indigenous children attending pre-primary, year one and year two at primary schools in the Perth metropolitan area participated in the study. The ear health of the participants was screened by Telethon Speech and Hearing Centre EarBus in 2011/2012. Participants’ reading and spelling skills were tested with culturally modifi ed sub-tests of the Queensland University Inventory of Literacy. Of the 46 Indigenous children, 18 presented with at least one episode of OM and one episode of HL. Results indicated that Indigenous participants had significantly poorer non-word and real word reading and spelling skills than their non-Indigenous peers. There was no significant difference between the groups of Indigenous participants with OM and HL and those with normal ear health on either measure. This research provides evidence to suggest that Indigenous children have ongoing literacy development difficulties and discusses the possibility of OM as one of many impacting factors
Development and initial validation of the Northwick Park Therapy Dependency Assessment
Objectives: To describe the development and initial validation of the Northwick Park Therapy Dependency Assessment (NPTDA) as a measure of therapy interventions in neurorehabilitation
RECOMMENDATIONS FOR IMPROVING SOFTWARE COST ESTIMATION IN DOD ACQUISITION
Acquisition initiatives within the Department of Defense (DOD) are becoming increasingly reliant on software. While the DOD has ample experience in estimating costs of hardware acquisition, expertise in estimating software acquisition costs is lacking. The objective of this capstone project is to summarize the current software cost estimating methods, analyze existing software cost estimating models, and suggest areas and methods for improvement. To accomplish this, surveys were conducted to gather program cost data, which was run through existing cost estimating models. From here, the outputs were compared to actual program costs. This established a baseline for the effectiveness of existing methods and guided suggestions for areas of improvement. The Software Resource Data Reports (SRDR) data used seemed to have spurious data reporting from at least one source, and the base cost estimation models were not found to be sufficiently accurate in our study. The capstone finds that calibrating the cost models to the data available improved those models dramatically. In all, the capstone recommends performing data realism checks upon SRDR submissions to ensure data accuracy and calibrating cost models for each contractor with the available data before using them to estimate DOD Acquisition costs.Civilian, Department of the ArmyCivilian, Department of the ArmyCivilian, Department of the ArmyCivilian, Department of the ArmyApproved for public release. Distribution is unlimited
Calibration of optical tweezers with positional detection in the back-focal-plane
We explain and demonstrate a new method of force- and position-calibration
for optical tweezers with back-focal-plane photo detection. The method combines
power spectral measurements of thermal motion and the response to a sinusoidal
motion of a translation stage. It consequently does not use the drag
coefficient of the trapped ob ject as an input. Thus, neither the viscosity,
nor the size of the trapped ob ject, nor its distance to nearby surfaces need
to be known. The method requires only a low level of instrumentation and can be
applied in situ in all spatial dimensions. It is both accurate and precise:
true values are returned, with small error-bars. We tested this experimentally,
near and far from surfaces. Both position- and force-calibration were accurate
to within 3%. To calibrate, we moved the sample with a piezo-electric
translation stage, but the laser beam could be moved instead, e.g. by
acousto-optic deflectors. Near surfaces, this precision requires an improved
formula for the hydrodynamical interaction between an infinite plane and a
micro-sphere in non-constant motion parallel to it. We give such a formula.Comment: Submitted to: Review of Scientific Instruments. 13 pages, 5 figures.
Appendix added (hydrodynamically correct calibration
Brief of Amici Curiae Michael L. Rosin, David G. Post, David F. Forte, Michael Stokes Paulsen, and Sotirios Barber in Support of Presidential Electors
The Framers of the Constitution crafted the Electoral College to be an independent institution with the responsibility of selecting the President and Vice-President. Therefore, they intended each elector to exercise independent judgment in deciding whom to vote for. A state cannot revise the Constitution unilaterally by reducing the elector to a ministerial agent who must vote in a particular way or face a sanction. The question of each elector’s moral or political obligation is not before the Court. Nor is the desirability of the current electoral system. Rather, this case turns on what the Constitution allows, and what it prohibits. The historical record strongly supports the notion that the Constitution allows an elector to exercise independent judgment and prohibits a State from interfering with an elector’s ability to do so—a position Congress has consistently reaffirmed.
This robust historical record supports only one conclusion: Our constitutional framework allows each elector to vote as he or she chooses
An Empirical Charge Transfer Potential with Correct Dissociation Limits
The empirical valence bond (EVB) method [J. Chem. Phys. 52, 1262 (1970)] has
always embodied charge transfer processes. The mechanism of that behavior is
examined here and recast for use as a new empirical potential energy surface
for large-scale simulations. A two-state model is explored. The main features
of the model are: (1) Explicit decomposition of the total system electron
density is invoked; (2) The charge is defined through the density decomposition
into constituent contributions; (3) The charge transfer behavior is controlled
through the resonance energy matrix elements which cannot be ignored; and (4) A
reference-state approach, similar in spirit to the EVB method, is used to
define the resonance state energy contributions in terms of "knowable"
quantities. With equal validity, the new potential energy can be expressed as a
nonthermal ensemble average with a nonlinear but analytical charge dependence
in the occupation number. Dissociation to neutral species for a gas-phase
process is preserved. A variant of constrained search density functional theory
is advocated as the preferred way to define an energy for a given charge.Comment: Submitted to J. Chem. Phys. 11/12/03. 14 pages, 8 figure
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