11,933 research outputs found
Rectenna system design
The function of the rectenna in the solar power satellite system is described and the basic design choices based on the desired microwave field concentration and ground clearance requirements are given. One important area of concern, from the EMI point of view, harmonic reradiation and scattering from the rectenna is also designed. An optimization of a rectenna system design to minimize costs was performed. The rectenna cost breakdown for a 56 w installation is given as an example
Tourists’ representations of coastal managed realignment as a climate change adaptation strategy.
In coastal destinations climate change adaptation is needed to address coastal erosion due to a combination of sea level rise and more frequent extreme weather events leading to loss of natural features and tourism infrastructure. Managed realignment is increasingly adopted as a strategy to address coastal change; however, this has often proved a contentious strategy with stakeholder groups. This study explores tourists' representational framework of managed realignment and how this frames understanding of the concept, understanding of how coastal resources might change and implications for future visitation. Data compiled using a questionnaire adopted a social representations theory perspective to analyse how collective tourists’ ideas may serve to mobilise the public in various ways. In general tourists have a poor understanding of managed realignment anchored to historic coastal management strategies and contextualised by use values with consequent implications for tourism planning and coastal management decision making
Tourism and the smartphone app: capabilities, emerging practice and scope in the travel domain.
Based on its advanced computing capabilities and ubiquity, the smartphone has rapidly been adopted as a tourism travel tool.With a growing number of users and a wide varietyof applications emerging, the smartphone is fundamentally altering our current use and understanding of the transport network and tourism travel. Based on a review of smartphone apps, this article evaluates the current functionalities used in the domestic tourism travel domain and highlights where the next major developments lie. Then, at a more conceptual level, the article analyses how the smartphone mediates tourism travel and the role it might play in more collaborative and dynamic travel decisions to facilitate sustainable travel. Some emerging research challenges are discussed
VLA 1.4GHz observations of the GOODS-North Field: Data Reduction and Analysis
We describe deep, new, wide-field radio continuum observations of the Great
Observatories Origins Deep Survey -- North (GOODS-N) field. The resulting map
has a synthesized beamsize of ~1.7" and an r.m.s. noise level of ~3.9uJy/bm
near its center and ~8uJy/bm at 15', from phase center. We have cataloged 1,230
discrete radio emitters, within a 40' x 40' region, above a 5-sigma detection
threshold of ~20uJy at the field center. New techniques, pioneered by Owen &
Morrison (2008), have enabled us to achieve a dynamic range of 6800:1 in a
field that has significantly strong confusing sources. We compare the 1.4-GHz
(20-cm) source counts with those from other published radio surveys. Our
differential counts are nearly Euclidean below 100uJy with a median source
diameter of ~1.2". This adds to the evidence presented by Owen & Morrison
(2008) that the natural confusion limit may lie near ~1uJy. If the Euclidean
slope of the counts continues down to the natural confusion limit as an
extrapolation of our log N - log S, this indicates that the cutoff must be
fairly sharp below 1uJy else the cosmic microwave background temperature would
increase above 2.7K at 1.4 GHz.Comment: Accepted for publication in ApJS. 16 pages, 19 figures. Radio data
and source list can be found at http://www.ifa.hawaii.edu/~morrison/GOODSN
Dorsalization of the neural tube by the non-neural ectoderm
The patterning of cell types along the dorsoventral axis of the spinal cord requires a complex set of inductive signals. While the chordamesoderm is a well-known source of ventralizing signals, relatively little is known about the cues that induce dorsal cell types, including neural crest. Here, we demonstrate that juxtaposition of the non-neural and neural ectoderm is sufficient to induce the expression of dorsal markers, Wnt-1, Wnt-3a and Slug, as well as the formation of neural crest cells. In addition, the competence of neural plate to express Wnt-1 and Wnt-3a appears to be stage dependent, occurring only when neural tissue is taken from stage 8–10 embryos but not from stage 4 embryos, regardless of the age of the non-neural ectoderm. In contrast to the induction of Wnt gene expression, neural crest cell formation and Slug expression can be induced when either stage 4 or stage 8–10 neural plates are placed in contact with the non-neural ectoderm. These data suggest that the non-neural ectoderm provides a signal (or signals) that specifies dorsal cell types within the neural tube, and that the response is dependent on the competence of the neural tissue
Land surface hydrology in a general circulation model: global and regional fields needed for validation
For the last two decades most general circulation models (GCMs) have included some kind of surface hydrology submodel. The content of these submodels is becoming increasingly complex and realistic. It is still easy to identify defects in present treatments. Yet, to improve our ability to model the contribution of land hydrology to climate and climate change, we must be concerned not with just the surface hydrology submodel per se, but also with how it works in the overall context of the GCM
Historical Sketch Of the Christian Woman\u27s Board of Missions
https://digitalcommons.acu.edu/crs_books/1119/thumbnail.jp
Historcial Sketch of the Christian Woman\u27s Board of Missions
A revised brief history on the acquisition of the Morehead Normal School by the Christian Woman\u27s Board of Missions in 1900.https://scholarworks.moreheadstate.edu/college_histories/1342/thumbnail.jp
Analysis of somitogenesis using multiphoton laser scanning microscopy (MPLSM)
In order to study complex cellular interactions in the developing somite and nervous system, we have been refining techniques for labeling and imaging individual cells within the living vertebrate embryo. Most recently, we have been using MPLSM to analyze cellular behaviors, such as cell migration, filopodial extension, cell process collapse, and neuron pathfinding using time-lapse microscopy in 3-dimensions (3-d). To enhance the efficiency of two-photon excitation in these samples, we have been using a Zeiss LSM 510 NLO fiber delivery system with a Grating Dispersion Compensator (GDC). This system not only offers the convenience of fiber delivery for coupling our Ti:Sapphire laser to the microscope, but also affords us precise control over the pulsewidth of the mode- locked beam. In addition, we have developed a novel peptide/non-cationic lipid gene delivery system to introduce GFP plasmid into somite cells. This approach has allowed us to generate detailed 3-d images of somite cell morphologies at various stages of somite development in a way that best preserves the vitality of the cells being imaged
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