659 research outputs found
Catalogue of lunar craters cross sections. I - Craters with peaks Research report no. 16
Lunar craters with centrally located peaks - tables and profile graph
Persistent Diaper Need Identified During the COVID-19 Pandemic
Diaper need refers to the lack of a sufficient supply of diapers to keep an infant or child clean, dry, and healthy. More than 1 in 3 households (36%) experienced diaper need in the first year of the COVID-19 pandemic
Mesoscale acid deposition modeling studies
The work performed in support of the EPA/DOE MADS (Mesoscale Acid Deposition) Project included the development of meteorological data bases for the initialization of chemistry models, the testing and implementation of new planetary boundary layer parameterization schemes in the MASS model, the simulation of transport and precipitation for MADS case studies employing the MASS model, and the use of the TASS model in the simulation of cloud statistics and the complex transport of conservative tracers within simulated cumuloform clouds. The work performed in support of the NASA/FAA Wind Shear Program included the use of the TASS model in the simulation of the dynamical processes within convective cloud systems, the analyses of the sensitivity of microburst intensity and general characteristics as a function of the atmospheric environment within which they are formed, comparisons of TASS model microburst simulation results to observed data sets, and the generation of simulated wind shear data bases for use by the aviation meteorological community in the evaluation of flight hazards caused by microbursts
A chirped-pulse Fourier-transform microwave/pulsed uniform flow spectrometer. I. The low-temperature flow system
We report the development of a new instrument that combines chirped-pulse microwave spectroscopy with a pulsed uniform supersonic flow. This combination promises a nearly universal detection method that can deliver isomer and conformer specific, quantitative detection and spectroscopic characterization of unstable reaction products and intermediates, product vibrational distributions, and molecular excited states. This first paper in a series of two presents a new pulsed-flow design, at the heart of which is a fast, high-throughput pulsed valve driven by a piezoelectric stack actuator. Uniform flows at temperatures as low as 20 K were readily achieved with only modest pumping requirements, as demonstrated by impact pressure measurements and pure rotational spectroscopy. The proposed technique will be suitable for application in diverse fields including fundamental studies in spectroscopy, kinetics, and reaction dynamics.National Science Foundation (U.S.) (Award MRI-ID 1126380
Cognitive Information Processing
Contains research objectives and summary of research on five research projects.National Science Foundation (Grant SED74-12653-A01)Joint Services Electronics Program (Contract DAAB07-76-C-1400)National Science Foundation (Grant ENG74-24344)Associated Press (Grant)National Institutes of Health (Grant 1 ROI GM22547-01)National Institutes of Health (Grant 2 PO1 GM19428-04
Pervious concrete: The art of improving strength properties
Urban cities in Malaysia are highly vulnerable to flash floods due to improper drainage system and the impermeable road surface. The Pervious Concrete (PC) Pavement for urban water management indicates the implementation of this system shows promising results to reduce flash flood volume and among the mitigation that can be applied is by adopting the permeable pavement systems. This was based on a case study of Sponge City in China. Since the properties normally consist of coarse aggregate only / or less fine aggregate to fill in the void structure. Regardless of the high advantage of these systems to reduce the flooding impact, this permeable pavement is known for its lower strength. Due to this fact, it is rare and impossible for this permeable pavement to be utilized at the main road and highway. Whereas, currently in Malaysia, the permeable concrete is only accustomed to light traffic loadings such as walkways and car park. This paper was discussing the way to improve the strength properties of PC pavements with a focus on sustainable development
Optical study of the electronic phase transition of strongly correlated YbInCu_4
Infrared, visible and near-UV reflectivity measurements are used to obtain
conductivity as a function of temperature and frequency in YbInCu_4, which
exhibits an isostructural phase-transition into a mixed-valent phase below
T_v=42 K. In addition to a gradual loss of spectral weight with decreasing
temperature extending up to 1.5 eV, a sharp resonance appears at 0.25 eV in the
mixed-valent phase. This feature can be described in terms of excitations into
the Kondo (Abrikosov-Suhl) resonance, and, like the sudden reduction of
resistivity, provides a direct reflection of the onset of coherence in this
strongly correlated electron system.Comment: 4 pages, 3 figures (to appear in Phys. Rev. B
Supersymmetric QCD correction to top-quark production at the Tevatron
We calculate the supersymmetric QCD correction to top-quark production at the
Fermilab Tevatron, allowing for arbitrary left-right mixing of the squarks. We
find that the correction is significant for several combinations of gluino and
squark masses, e.g. +33% for m_{\tilde g}=200 GeV, m_{\tilde t} = m_{\tilde q}
=75 GeV.Comment: To appear Phys. Rev. D, added discussion of some references, two
figures replaced with one, 15 pages, 7 ps figures include
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