790 research outputs found
Application of ERTS-1 imagery and underflight photography in the detection and monitoring of forest insect infections in the Sierra Nevada Mountains of California
The author has identified the following significant results. Analysis of ERTS-1 imagery with underflight aerial photo support including U-2, in the Sierra Nevada Mountains of California, indicates promising possibilities of detecting and monitoring forest insect outbreaks visually with some mechanical support utilizing the VP-8 image analyzer. Visually, it is possible at a scale of 1:1,000,000 to discriminate between large areas of damaged and undamaged forests; timbered and non-timbered areas; pasture land and cultivated fields; desert and riparian vegetation. At a scale of 1:80,000 it is possible to distinguish among three classes of tree mortality; defoliated and undefoliated areas; non-host mixed conifers; and mountain meadows, rock domes, lakes and glaciers. Machine tests showed significant differences in image densities among various bands and mortality areas
The use of multispectral sensing techniques to detect ponderosa pine trees under stress from insect or pathogenic organisms
Application of multispectral sensors to detect insect and disease infestation of ponderosa pine tree
Seasonal and daily patterns of the mating calls of the oyster toadfish, Opsanus tau.
Author Posting. © University of Chicago Press, 2019. This article is posted here by permission of [publisher] for personal use, not for redistribution. The definitive version was published in Van Wert, J. C., & Mensinger, A. F. Seasonal and daily patterns of the mating calls of the oyster toadfish, Opsanus tau. Biological Bulletin, 236(2), (2019):97-107, doi:10.1086/701754.Acoustic communication is vital across many taxa for mating behavior, defense, and social interactions. Male oyster toadfish, Opsanus tau, produce courtship calls, or “boatwhistles,” characterized by an initial broadband segment (30–50 ms) and a longer tone-like second part (200–650 ms) during mating season. Male calls were monitored continuously with an in situ SoundTrap hydrophone that was deployed in Eel Pond, Woods Hole, Massachusetts, during the 2015 mating season. At least 10 vocalizing males were positively identified by their unique acoustic signatures. This resident population was tracked throughout the season, with several individuals tracked for extended periods of time (72 hours). Toadfish began calling in mid-May when water temperature reached 14.6 °C with these early-season “precursor” boatwhistles that were shorter in duration and contained less distinct tonal segments compared to calls later in the season. The resident toadfish stopped calling in mid-August, when water temperature was about 25.5 °C. The pulse repetition rate of the tonal part of the call was significantly related to ambient water temperature during both short-term (hourly) and long-term (weekly) monitoring. This was the first study to monitor individuals in the same population of oyster toadfish in situ continuously throughout the mating season.We thank Emily Cardinal for help with data collection and initial hydrophone setup, the Marine Resources Center at Marine
Biological Laboratory for dock space and resources, John Atkins for SoundTrap hydrophone support, and Beth Giuffrida for analysis support. Rosalyn Putland and Jenni Stanley are gratefully acknowledged for coding assistance. We also thank UCSBPSTAT for statistics guidance.We are also grateful to the three anonymous reviewers and the editor for their comments. This study was made possible by National Science Foundation grants IOS 1354745 and DBI 1359230.2020-02-0
Applications of Transmission Electron Microscopy to Coal
Coal consists of a hydrocarbon matrix in which minerals are embedded. The hydrocarbon matter also contains impurities distributed as individual atoms. Thus, coal has phases similar to those in metallic or ceramic alloy systems; a matrix, included precipitates and atoms distributed individually in solid solution. Consequently, techniques of electron microscopy developed to examine metallic and ceramic alloy systems are directly applicable to coal. We report application of microanalytical techniques of electron microscopy to coal using examples of measurements for several coals. Identification and characterization of clays and sulfides is described. Use of x-ray emission spectroscopy for organic element measurement is emphasized
Lateral line sensitivity in free-swimming toadfish Opsanus tau
Author Posting. © The Company of Biologists, 2019. This article is posted here by permission of Company of Biologists for personal use, not for redistribution. The definitive version was published in Journal of Experimental Biology 222(2) (2019): jeb190587, doi:10.1242/jeb.190587.A longstanding question in aquatic animal sensory physiology is the impact of self-generated movement on lateral line sensitivity. One hypothesis is that efferent modulation of the sensory hair cells cancels self-generated noise and allows fish to sample their surroundings while swimming. In this study, microwire electrodes were chronically implanted into the anterior lateral line nerve of oyster toadfish and neural activity was monitored during forward movement. Fish were allowed to freely swim or were moved by a tethered sled. In all cases, neural activity increased during movement with no evidence of efferent modulation. The anterior lateral line of moving fish responded to a vibrating sphere or the tail oscillations of a robotic fish, indicating that the lateral line also remains sensitive to outside stimulus during self-generated movement. The results suggest that during normal swim speeds, lateral line neuromasts are not saturated and retain the ability to detect external stimuli without efferent modulation.Funding was provided by National Science Foundation grants IOS 1354745 and DBI 1359230 and 1659604.2020-01-2
Combination of DROOL rules and Protégé knowledge bases in the ONTO-H annotation tool
ONTO-H is a semi-automatic collaborative tool for the semantic annotation of documents, built as a Protégé 3.0 tab plug-in. Among its multiple functionalities aimed at easing the document annotation process, ONTO-H uses a rule-based system to create cascading annotations out from a single drag and drop operation from a part of a document into an already existing concept or instance of the domain ontology being used for annotation. It also gives support to the detection of name conflicts and instance duplications in the creation of the annotations. The rule system runs on top of the open source rule engine DROOLS and is connected to the domain ontology used for annotation by means of an ad-hoc programmed Java proxy
Usefulness of the Lang Stereotest with an infant population
Sixty-four healthy full term infants between 6 and 24 months of age were tested using the Lang Stereotest. A full vision examination including visual acuity assessment using the Teller acuity card preferential looking procedure, near point of convergence, Worth test for eccentric fixation, Hirschberg test, and monocular estimate method to measure accommodative posture was performed. Ocular health was also assessed to rule out pathology. Results showed that 90% of the 6.0 to 12.0 month age group, 100% of both the 12.0 to 18.0 and 18.0 to 24.0 month age groups were able to respond positively to at least one stereo image on the Lang Stereotest. Performance showed improvement with age
Photochemistry in the arctic free troposphere: Ozone budget and its dependence on nitrogen oxides and the production rate of free radicals
Abstract. Local ozone production and loss rates for the arctic free troposphere (58–85 ◦ N, 1–6 km, February–May) during the Tropospheric Ozone Production about the Spring Equinox (TOPSE) campaign were calculated using a constrained photochemical box model. Estimates were made to assess the importance of local photochemical ozone production relative to transport in accounting for the springtime maximum in arctic free tropospheric ozone. Ozone production and loss rates from our diel steady-state box model constrained by median observations were first compared to two point box models, one run to instantaneous steady-state and the other run to diel steady-state. A consistent picture of local ozone photochemistry was derived by all three box models suggesting that differences between the approaches were not critical. Our model-derived ozone production rates increased by a factor of 28 in the 1–3 km layer and a factor of 7 in the 3–6 km layer between February and May. The arctic ozone budget required net import of ozone into the arctic free troposphere throughout the campaign; however, the transport term exceeded the photochemical production only in the lower free troposphere (1–3 km) between February and March. Gross ozone production rates were calculated to increase linearly with NOx mixing ratios up to ∼300 pptv in February and for NOx mixing ratio
Photochemistry in the arctic free troposphere: NOx budget and the role of odd nitrogen reservoir recycling
The budget of nitrogen oxides (NOx) in the arctic free troposphere is calculated with a constrained photochemical box model using aircraft observations from the Tropospheric O3 Production about the Spring Equinox (TOPSE) campaign between February and May. Peroxyacetic nitric anhydride (PAN) was observed to be the dominant odd nitrogen species (NOy) in the arctic free troposphere and showed a pronounced seasonal increase in mixing ratio. When constrained to observed acetaldehyde (CH3CHO) mixing ratios, the box model calculates unrealistically large net NOx losses due to PAN formation (62pptv/day for May, 1-3km). Thus, given our current understanding of atmospheric chemistry, these results cast doubt on the robustness of the CH3CHO observations during TOPSE. When CH3CHO was calculated to steady state in the box model, the net NOx loss to PAN was of comparable magnitude to the net NOx loss to HNO3 (NO2 reaction with OH) for spring conditions. During the winter, net NOx loss due to N2O5 hydrolysis dominates other NOx loss processes and is near saturation with respect to further increases in aerosol surface area concentration. NOx loss due to N2O5 hydrolysis is sensitive to latitude and month due to changes in diurnal photolysis (sharp day-night transitions in winter to continuous sun in spring for the arctic). Near NOx sources, HNO4 is a net sink for NOx; however, for more aged air masses HNO4 is a net source for NOx, largely countering the NOx loss to PAN, N2O5 and HNO3. Overall, HNO4 chemistry impacts the timing of NOx decay and O3 production; however, the cumulative impact on O3 and NOx mixing ratios after a 20-day trajectory is minimal. © 2003 Elsevier Science Ltd. All rights reserved
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Thermal Behavior in the Lens Process
Direct laser metal deposition processing is a promising manufacturing technology which
could significantly impact the length oftime between initial concept and finished part. For
adoption ofthis technology in the manufacturing environment, further understanding is required
to ensure robust components with appropriate properties are routinelyfabricated. This requires a
complete understanding ofthe thermal history.during part fabrication and control ofthis behavior.
This paper will describe our research to understand the thermal behavior for the Laser Engineered
Net Shaping (LENS) process!, where a component is fabricated by focusing a laser beam onto a
substrate to create a molten pool in which powder particles are simultaneously injected to build
each layer. The substrate is moved beneath the l~ser beam to deposit a thin cross section, thereby
creating the desired geometry for each layer. After deposition of each layer, the powder delivery
nozzle and focusing lens assembly is incremented in the positive Z-direction, thereby building a
three dimensional component layer additively.
It is important to control the thermal behavior to reproducibly fabricate parts. The
ultimate intent is to monitor the thermal signatures and to incorporate sensors and feedback
algorithms to control part fabrication. With appropriate control, the geometric properties
(accuracy, surface finish, low warpage) as well as the materials' properties (e.g. strength,
ductility) of a component can be dialed into the part through the fabrication parameters. Thermal
monitoring techniques will be described, and their particular benefits highlighted. Preliminary
details in correlating thermal behavior with processing results will be discussed.Mechanical Engineerin
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