1,224 research outputs found
Comparison of satellite based cloud retrieval methods for cirrus and stratocumulus
One difficulty in using satellite remote sensing data is the spatial variability of cloud properties on scales smaller than most meteorological satellite fields of view (approx. 4 to 8 km). The variation is examined of satellite derived cloud cover as a function of the satellite sensor spatial resolution for seven cloud cover retrieval methods: (1) Reflectance threshold; (2) Temperature threshold; (3) ISCCP; (4) HBTM (Hybrid Bispectral Threshold Method); (5) NCLE; (6) Spatial coherence; and (7) Functional Box Counting. The first two methods are simple single spectral thresholds which specify a satellite pixel as cloud filled if the measured reflectance is greater than the threshold, or if the measured equivalent blackbody temperature is less than the threshold. The next three methods are bispectral, using one visible wavelength window channel and one thermal infrared wavelength window. The final two algorithms rely on the spatial variability within the cloud field to determine cloud cover. Spatial coherence assumes only that the cloud field occurs in a single layer and that the clouds are optically thick in the infrared window. LANDSAT Thematic Mapper (TM) data is used to test the spatial resolution dependence of the cloud algorithms. The ISCCP bispectral threshold applied to the full resolution data is used as the reference or truth cloud cover, after which the retrieval methods are applied to the spatial resolutions. Studies of the fraction of pixels in the scene at cloud edge, and of the profile of reflectance and temperature near cloud edges indicate an uncertainty in the reference cloud fraction of 1 to 5 percent
Locoregional techniques for dogs undergoing tibial plateau leveling osteotomy : a literature review, anesthesiologist survey, and future directions
Over the past several decades there have been significant advancements in our understanding and ability to provide effective analgesia to animals undergoing elective orthopedic surgery through methods that can help us minimize the risk of adverse effects. In dogs, one of the most common elective orthopedic surgeries performed on the pelvic limb is the tibial plateau levelling osteotomy (TPLO) for the treatment of cranial cruciate ligament disease (CCLD). While historically the lumbosacral epidural has been considered the primary method of locoregional therapy for dogs undergoing TPLO, the development of peripheral nerve blocks has been a rapidly growing area of veterinary research. An in-depth knowledge of the pain cycle and ways to intervene in nociception is an immense area of interest in both the human and veterinary worlds. This thesis examines the pain cycle and how protective pain becomes pathologic, along with an exploration of the various pharmaceuticals and locoregional techniques that can be utilized for the lumbosacral epidural, peripheral nerve block, and the peri-incisional infiltration technique. Additional information about locoregional analgesic preferences is gleaned through a survey-based study of board-certified veterinary anesthesiologists. This study demonstrated that newer graduates prefer the use of bupivacaine-dexmedetomidine for peripheral nerve blocks in dogs undergoing TPLO and that analgesic decision-making in the clinical setting is multi-factorial. Overall, this research demonstrates that while significant advancements have occurred in the veterinary anesthesia and analgesia, further research into the effectiveness of various techniques as well as the clinical application of these methods is needed.Includes bibliographical references
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Common themes and missing pieces: the educational value of postgraduate teaching development programmes
The purpose of this article is to present and discuss the findings of a literature review undertaken by three members of staff based at City University London, who are also members of a programme team that runs a professional development programme for higher education teachers. The original purpose of the literature review was to provide a deeper and more research-informed mechanism for evaluating and developing the aforementioned programme. Whilst focused in its intentions, the results of the review suggest that the existing research terrain about such programmes might be characterised in terms of common themes (areas for which there is already a range of published research) and missing pieces (areas for which there appears to be a paucity of published material). The authors are now using these results to continue developing their own programme, and as a starting point for follow-up research. However, it is hoped that the review will be of relevance to a wider audience, encouraging others to undertake research to address the missing pieces and as a source for others to enhance their own teaching development programmes
Foam-on-Tile Damage Model
An impact model was developed to predict how three specific foam types would damage the Space Shuttle Orbiter insulating tiles. The inputs needed for the model are the foam type, the foam mass, the foam impact velocity, the foam impact incident angle, the type being impacted, and whether the tile is new or aged (has flown at least one mission). The model will determine if the foam impact will cause damage to the tile. If it can cause damage, the model will output the damage cavity dimensions (length, depth, entry angle, exit angle, and sidewall angles). It makes the calculations as soon as the inputs are entered (less than 1 second). The model allows for the rapid calculation of numerous scenarios in a short time. The model was developed from engineering principles coupled with significant impact testing (over 800 foam impact tests). This model is applicable to masses ranging from 0.0002 up to 0.4 pound (0.09 up to 181 g). A prior tool performed a similar function, but was limited to the assessment of a small range of masses and did not have the large test database for verification. In addition, the prior model did not provide outputs of the cavity damage length, entry angle, exit angle, or sidewall angles
Statistical Analyses of Satellite Cloud Object Data From CERES
Three boundary-layer cloud object types, stratus, stratocumulus and cumulus, that occurred over the Pacific Ocean during January-August 1998, are identified from the CERES (Clouds and the Earth s Radiant Energy System) single scanner footprint (SSF) data from the TRMM (Tropical Rainfall Measuring Mission) satellite. This study emphasizes the differences and similarities in the characteristics of each cloud-object type between the tropical and subtropical regions and among different size categories and among small geographic areas. Both the frequencies of occurrence and statistical distributions of cloud physical properties are analyzed. In terms of frequencies of occurrence, stratocumulus clouds dominate the entire boundary layer cloud population in all regions and among all size categories. Stratus clouds are more prevalent in the subtropics and near the coastal regions, while cumulus clouds are relatively prevalent over open ocean and the equatorial regions, particularly, within the small size categories. The largest size category of stratus cloud objects occurs more frequently in the subtropics than in the tropics and has much larger average size than its cumulus and stratocumulus counterparts. Each of the three cloud object types exhibits small differences in statistical distributions of cloud optical depth, liquid water path, TOA albedo and perhaps cloud-top height, but large differences in those of cloud-top temperature and OLR between the tropics and subtropics. Differences in the sea surface temperature (SST) distributions between the tropics and subtropics influence some of the cloud macrophysical properties, but cloud microphysical properties and albedo for each cloud object type are likely determined by (local) boundary-layer dynamics and structures. Systematic variations of cloud optical depth, TOA albedo, cloud-top height, OLR and SST with cloud object sizes are pronounced for the stratocumulus and stratus types, which are related to systematic variations of the strength of inversion with cloud object sizes, produced by large-scale subsidence. The differences in cloud macrophysical properties over small regions are significantly larger than those of cloud microphysical properties and TOA albedo, suggesting a greater control of (local) large-scale dynamics and other factors on cloud object properties. When the three cloud object types are combined, the relative population among the three types is the most important factor for determining the cloud object properties in a Pacific transect where the transition of boundary-layer cloud types takes place
Rethinking How Humanities Think: Daring and 'do / make / think'
Whether the administrative organization of people in the humanities takes the form of a department of English, philosophy, history, or comparative literature, etc., in the modern university, humanistic disciplines continue to reflect the institution in which they reside, even as that institution submits them to "two cultures," "science wars," or corporatization. Neither disciplinary distinctiveness, group identity, nor solidarity within the humanities as a division protect these forms of inquiry and exchange against dominant institutional imperatives and incursions. As a traditional container for academic activity, departments contribute to what is increasingly becoming a black box nexus of activity around the individual players: the black box being a reduction of a complex process to simply its inputs and outputs with the box around process itself
FIRE Cirrus on October 28, 1986: LANDSAT; ER-2; King Air; theory
A simultaneous examination was conducted of cirrus clouds in the FIRE Cirrus IFO-I on 10/28/86 using a multitude of remote sensing and in-situ measurements. The focus is cirrus cloud radiative properties and their relationship to cloud microphysics. A key element is the comparison of radiative transfer model calculations and varying measured cirrus radiative properties (emissivity, reflectance vs. wavelength, reflectance vs. viewing angle). As the number of simultaneously measured cloud radiative properties and physical properties increases, more sharply focused tests of theoretical models are possible
Common themes and missing pieces: the educational value of postgraduate teaching development programmes
The purpose of this article is to present and discuss the findings of a literature review undertaken by three members of staff based at City University London, who are also members of a programme team that runs a professional development programme for higher education teachers. The original purpose of the literature review was to provide a deeper and more research-informed mechanism for evaluating and developing the aforementioned programme. Whilst focused in its intentions, the results of the review suggest that the existing research terrain about such programmes might be characterised in terms of common themes (areas for which there is already a range of published research) and missing pieces (areas for which there appears to be a paucity of published material). The authors are now using these results to continue developing their own programme, and as a starting point for follow-up research. However, it is hoped that the review will be of relevance to a wider audience, encouraging others to undertake research to address the missing pieces and as a source for others to enhance their own teaching development programmes
Developing effective practice learning for tomorrow's social workers
This paper considers some of the changes in social work education in the UK, particularly focusing on practice learning in England. The changes and developments are briefly identified and examined in the context of what we know about practice learning. The paper presents some findings from a small scale qualitative study of key stakeholders involved in practice learning and education in social work and their perceptions of these anticipated changes, which are revisited at implementation. The implications for practice learning are discussed
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