376 research outputs found
PCM telemetry data compression study, phase II Quarterly report, 25 Nov. 1965 - 25 Feb. 1966
Model analyses and computer simulations used in data compression study for improved pulse code modulation telemetry link
The Application and Energy Savings Potential of Occupancy Counters/Transmitters in Office Buildings
In conventional office building
design, fresh air requirements are
estimated for full occupancy in the
building. Typically, fresh air requirements
range from 5 to 15 cubic feet per minute
per person expected to occupy the building.
While the design total amount of fresh air
used is satisfactory for full occupancy of
the building, there are many instances less
than the design occupancy. Thus, there may
be many instances in a commercial building
where more fresh air is used than is
actually required because the occupancy is
below the design occupancy.
In hot and humid climates, such as the
Gulf Southwest, a considerable portion of
the cooling energy in a commercial building
is expended cooling and dehumidifying the
air needed to maintain fresh air
requirements. If the total amount of fresh
air could be reduced to just match that
needed by the number of occupants in a
building, it would be possible to reduce
the energy use for cooling.
This paper summarizes the design and
use of an occupancy counter/transmitter
that can be used to count the number of
people entering/leaving a building and make
adjustments in the amount of fresh air used
in the building. Sample economics of the
system, including initial costs and savings
are also provided
PCM telemetry data compression study, phase 1 Final report, 15 Sep. 1964 - 15 Aug. 1965
Pulse Code Modulation /PCM/ telemetry data compression study using S-6 Explorer XVII DAT
The Impacts of Microphysics and Planetary Boundary Layer Physics on Model Simulations of U. S. Deep South Summer Convection
Inspection of output from various configurations of high-resolution, explicit convection forecast models such as the Weather Research and Forecasting (WRF) model indicates significant sensitivity to the choices of model physics parameterizations employed. Some of the largest apparent sensitivities are related to the specifications of the cloud microphysics and planetary boundary layer physics packages. In addition, these sensitivities appear to be especially pronounced for the weakly-sheared, multicell modes of deep convection characteristic of the Deep South of the United States during the boreal summer. Possible ocean-land sensitivities also argue for further examination of the impacts of using unique ocean-land surface initialization datasets provided by the NASA Short-term Prediction Research and Transition (SPoRT Center to select NOAA/NWS weather forecast offices. To obtain better quantitative understanding of these sensitivities and also to determine the utility of the ocean-land initialization data, we have executed matrices of regional WRF forecasts for selected convective events near Mobile, AL (MOB), and Houston, TX (HGX). The matrices consist of identically initialized WRF 24-h forecasts using any of eight microphysics choices and any of three planetary boundary layer choices. The resulting 24 simulations performed for each event within either the MOB or HGX regions are then compared to identify the sensitivities of various convective storm metrics to the physics choices. Particular emphasis is placed on sensitivities of precipitation timing, intensity, and coverage, as well as amount and coverage of lightning activity diagnosed from storm kinematics and graupel in the mixed phase layer. The results confirm impressions gleaned from study of the behavior of variously configured WRF runs contained in the ensembles produced each spring at the Center for the Analysis and Prediction of Storms, but with the benefit of more straightforward control of the physics package choices. The design of the experiments thus allows for more direct interpretation of the sensitivities to each possible physics combination. The results should assist forecasters in their efforts to anticipate and correct for possible biases in simulated WRF convection patterns, and help the modeling community refine their model parameterizations
Field testing for toxic algae with a microarray: initial results from the MIDTAL project
One of the key tasks in the project MIDTAL (MIcroarrays for the Detection of Toxic ALgae) is to demonstrate the applicability of microarrays to monitor harmful algae across a broad range of ecological niches and toxic species responsible for harmful algal events. Water samples are collected from a series of sites used in national phytoplankton and biotoxin monitoring programmes across Europe. The samples are filtered; the rRNA is extracted, labelled with a fluorescent dye and applied to a microarray chip. The signal intensity from >120 probes previously spotted on the chip is measured and analysed. Preliminary results comparing microarray signal intensities with actual field counts are presented
Solid deuterium surface degradation at ultracold neutron sources
Solid deuterium (sD_2) is used as an efficient converter to produce ultracold
neutrons (UCN). It is known that the sD_2 must be sufficiently cold, of high
purity and mostly in its ortho-state in order to guarantee long lifetimes of
UCN in the solid from which they are extracted into vacuum. Also the UCN
transparency of the bulk sD_2 material must be high because crystal
inhomogeneities limit the mean free path for elastic scattering and reduce the
extraction efficiency. Observations at the UCN sources at Paul Scherrer
Institute and at Los Alamos National Laboratory consistently show a decrease of
the UCN yield with time of operation after initial preparation or later
treatment (`conditioning') of the sD_2. We show that, in addition to the
quality of the bulk sD_2, the quality of its surface is essential. Our
observations and simulations support the view that the surface is deteriorating
due to a build-up of D_2 frost-layers under pulsed operation which leads to
strong albedo reflections of UCN and subsequent loss. We report results of UCN
yield measurements, temperature and pressure behavior of deuterium during
source operation and conditioning, and UCN transport simulations. This,
together with optical observations of sD_2 frost formation on initially
transparent sD_2 in offline studies with pulsed heat input at the North
Carolina State University UCN source results in a consistent description of the
UCN yield decrease.Comment: 15 pages, 22 figures, accepted by EPJ-
Field testing for toxic algae with a microarray: initial results from the MIDTAL project
One of the key tasks in MIDTAL (MIcroarrays for the Detection of Toxic ALgae) is to demonstrate
the applicability of microarrays to monitor harmful algae across a broad range of ecological niches
and toxic species responsible for harmful algal events. Water samples are collected from a series of
sites used in national phytoplankton and biotoxin monitoring across Europe. The samples are filtered;
rRNA is extracted, labelled with a fluorescent dye and applied to a microarray chip. The signal
intensity from >120 probes previously spotted on the chip is measured and analysed. Preliminary
results comparing microarray signal intensities with actual field counts are presented.Versión del edito
The evolution of photosynthesis in chromist algae through serial endosymbioses
Chromist algae include diverse photosynthetic organisms of great ecological and social importance. Despite vigorous research efforts, a clear understanding of how various chromists acquired photosynthetic organelles has been complicated by conflicting phylogenetic results, along with an undetermined number and pattern of endosymbioses, and the horizontal movement of genes that accompany them. We apply novel statistical approaches to assess impacts of endosymbiotic gene transfer on three principal chromist groups at the heart of long-standing controversies. Our results provide robust support for acquisitions of photosynthesis through serial endosymbioses, beginning with the adoption of a red alga by cryptophytes, then a cryptophyte by the ancestor of ochrophytes, and finally an ochrophyte by the ancestor of haptophytes. Resolution of how chromist algae are related through endosymbioses provides a framework for unravelling the further reticulate history of red algal-derived plastids, and for clarifying evolutionary processes that gave rise to eukaryotic photosynthetic diversity
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