1,983 research outputs found
Solar residential heating and cooling system
System has been placed in operation to verify technical feasibility of using solar energy to provide residential heating and cooling. Complete system analysis was performed to provide design information
Solar residential heating and cooling system development test program
A solar heating and cooling system is described, which was installed in a simulated home at Marshall Space Flight Center. Performance data are provided for the checkout and initial operational phase for key subsystems and for the total system. Valuable information was obtained with regard to operation of a solar cooling system during the first summer of operation. Areas where improvements and modifications are required to optimize such a system are discussed
Hebb repetition effects for non-verbal visual sequences: determinants of sequence acquisition.
We report four experiments premised upon the work of Horton et al. (2008) and Page et al. (2013), and explore conditions under which the visual Hebb repetition effect is observed. Experiment 1 showed that repetition learning is evident when the items comprising the non- repeated (filler) sequences and the repeated (Hebb) sequences are different (no-overlap). However, learning is abolished when the filler and Hebb sequences comprise the same items (full-overlap). Learning of the repeated sequence persisted when repetition spacing was increased to 6 trials (Experiment 2), consistent with that shown for verbal stimuli (Page et al., 2013). In Experiment 3 it was shown that learning for the repeated sequence is accentuated when the output motor response at test is also repeated for the Hebb sequence, but only under conditions of no-overlap. In Experiment 4, repetition spacing was re-examined with a repeated motor output response (a closer methodological analogue to Page et al., 2013). Under these conditions, the gradient of Hebb repetition learning for 6 trial repetition intervals was markedly similar to that for 3 trial intervals. These findings further support the universality of the Hebb repetition effect across memory and are discussed in terms of evidence for amodality within sequence memory
Tissue-specific expression of high-voltage-activated dihydropyridine-sensitive L-type calcium channels
The cloning of the cDNA for the α1 subunit of L-type calcium channels revealed that at least two genes (CaCh1 and CaCh2) exist which give rise to several splice variants. The expression of mRNA for these α1 subunits and the skeletal muscle α2/δ, β and γ subunits was studied in rabbit tissues and BC3H1 cells. Nucleic-acid-hybridization studies showed that the mRNA of all subunits are expressed in skeletal muscle, brain, heart and aorta. However, the α1-, β- and γ-specific transcripts had different sizes in these tissues. Smooth muscle and heart contain different splice variants of the CaCh2 gene. The α1, β and γ mRNA are expressed together in differentiated but not in proliferating BC3H1 cells. A probe specific for the skeletal muscle α2/δ subunit did not hybridize to poly(A)-rich RNA from BC3H1 cells. These results suggest that different splice variants of the genes for the α1, β and γ subunits exist in tissues containing L-type calcium channels, and that their expression is regulated in a coordinate manner
DIAmante TESS AutoRegressive Planet Search (DTARPS): II. Hundreds of New TESS Candidate Exoplanets
The DIAmante TESS AutoRegressive Planet Search (DTARPS) project seeks to
identify photometric transiting planets from 976,814 southern hemisphere stars
observed in Year 1 of the TESS mission. This paper follows the methodology
developed by Melton et al. (Paper I) using light curves extracted and
pre-processed by the DIAmante project (Montalto et al. 2020). Paper I emerged
with a list of 7,377 light curves with statistical properties characteristic of
transiting planets but dominated by False Alarms and False Positives. Here a
multistage vetting procedure is applied including: centroid motion and crowding
metrics, False Alarm and False Positive reduction, photometric binary
elimination, and ephemeris match removal. The vetting produces a catalog of 462
DTARPS Candidates across the southern ecliptic hemisphere and 310 objects in a
spatially incomplete Galactic Plane list. Fifty-eight percent were not
previously identified as transiting systems. Candidates are flagged for
possible blending from nearby stars based on Zwicky Transient Facility data and
for possible radial velocity variations based on Gaia satellite data. Orbital
periods and planetary radii are refined using astrophysical modeling; the
resulting parameters closely match published values for Confirmed Planets.
Their properties are discussed in Paper III.Comment: 25 pages, 10 figures, submitted to AAS Journals. Machine Readable
Tables and Figure Sets for Tables 1 and 4 are available at
https://drive.google.com/drive/folders/1DyxNcNlfcHHAoCdsaipxxIbP5A2FPeyi?usp=share_lin
DIAmante TESS AutoRegressive Planet Search (DTARPS): III. Understanding the DTARPS Candidate Transiting Planet Catalogs
The DIAmante TESS AutoRegressive Planet Search (DTARPS) project, using novel
statistical methods, has identified several hundred candidates for transiting
planetary systems obtained from 0.9 million Full Frame Image light curves
obtained in the TESS Year 1 southern hemisphere survey (Melton et al. 2022a and
2022b). Several lines of evidence, including limited reconnaissance
spectroscopy, indicate that at least half are true planets rather than False
Positives. Here various population properties of these objects are examined.
Half of the DTARPS candidates are hot Neptunes, populating the 'Neptune desert'
found in Kepler planet samples. The DTARPS samples also identify dozens of
Ultra Short Period planets with orbital periods down to 5 hours, high priority
systems for atmospheric transimssion spectroscopy, and planets orbiting
low-mass M stars. DTARPS methodology is sufficiently well-characterized at each
step that preliminary planet occurrence rates can be estimated. Except for the
increase in hot Neptunes, DTARPS planet occurrence rates are consistent with
Kepler rates. Overall, DTARPS provides one of the largest and most reliable
catalog of TESS exoplanet candidates that can be tapped to improve our
understanding of various exoplanetary populations and astrophysical processes.Comment: 29 pages, 16 figures, submitted to the AAS Journals February 13, 202
DIAmante TESS AutoRegressive Planet Search (DTARPS): I. Analysis of 0.9 Million Light Curves
Nearly one million light curves from the TESS Year 1 southern hemisphere
extracted from Full Frame Images with the DIAmante pipeline are processed
through the AutoRegressive Planet Search statistical procedure. ARIMA models
remove trends and lingering autocorrelated noise, the Transit Comb Filter
identifies the strongest periodic signal in the light curve, and a Random
Forest machine learning classifier is trained and applied to identify the best
potential candidates. Classifier training sets include injections of both
planetary transit signals and contaminating eclipsing binaries. The optimized
classifier has a True Positive Rate of 92.8% and a False Positive Rate of 0.37%
from the labeled training set. The result of this DIAmante TESS autoregressive
planet search (DTARPS) analysis is a list of 7,377 potential exoplanet
candidates. The classifier has a False Positive Rate of 0.3%, a 64% recall rate
for previously confirmed exoplanets, and a 78% negative recall rate for known
False Positives. The completeness map of the injected planetary signals shows
high recall rates for planets with 8 - 30 R(Earth) radii and periods 0.6-13
days and poor completeness for planets with radii < 2 R(Earth) or periods < 1
day. The list has many False Alarms and False Positives that need to be culled
with multifaceted vetting operations (Paper II).Comment: 46 pages, 21 figures, submitted to AAS Journals. A Machine Readable
Table for Table 3 is available at
https://drive.google.com/drive/folders/1DyxNcNlfcHHAoCdsaipxxIbP5A2FPey
Comparison of engagement and emotional responses of older and younger adults interacting with 3D cultural heritage artefacts on personal devices
The availability of advanced software and less expensive hardware allows museums to preserve and share artefacts digitally. As a result, museums are frequently making their collections accessible online as interactive, 3D models. This could lead to the unique situation of viewing the digital artefact before the physical artefact. Experiencing artefacts digitally outside of the museum on personal devices may affect the user's ability to emotionally connect to the artefacts. This study examines how two target populations of young adults (18–21 years) and the elderly (65 years and older) responded to seeing cultural heritage artefacts in three different modalities: augmented reality on a tablet, 3D models on a laptop, and then physical artefacts. Specifically, the time spent, enjoyment, and emotional responses were analysed. Results revealed that regardless of age, the digital modalities were enjoyable and encouraged emotional responses. Seeing the physical artefacts after the digital ones did not lessen their enjoyment or emotions felt. These findings aim to provide an insight into the effectiveness of 3D artefacts viewed on personal devices and artefacts shown outside of the museum for encouraging emotional responses from older and younger people
Assessing architectural evolution: A case study
This is the post-print version of the Article. The official published can be accessed from the link below - Copyright @ 2011 SpringerThis paper proposes to use a historical perspective on generic laws, principles,
and guidelines, like Lehman’s software evolution laws and Martin’s design principles, in order to achieve a multi-faceted process and structural assessment of a system’s architectural evolution. We present a simple structural model with associated historical metrics and
visualizations that could form part of an architect’s dashboard. We perform such an assessment for the Eclipse SDK, as a case study of a large, complex, and long-lived system for which sustained effective architectural evolution is paramount. The twofold aim of checking generic principles on a well-know system is, on the one hand,
to see whether there are certain lessons that could be learned for best practice of architectural evolution, and on the other hand to get more insights about the applicability of such principles. We find that while the Eclipse SDK does follow several of the laws and principles, there are some deviations, and we discuss areas of architectural improvement and limitations of the assessment approach
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Dwarf mistletoe survey, Hebgen Lake Ranger District, Gallatin National Forest, Montana
Large areas of dwarf mistletoe-free, all-aged lodgepole pine have been identified in the West Yellowstone Basin. The option of uneven-aged management in these areas remains available to the District
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