6,556 research outputs found
Magnetic-flux pump
A magnetic flux pump is described for increasing the intensity of a magnetic field by transferring flux from one location to the magnetic field. The device includes a pair of communicating cavities formed in a block of superconducting material, and a piston for displacing the trapped magnetic flux into the secondary cavity producing a field having an intense flux density
DichroMatch: a website for similarity searching of circular dichroism spectra
Circular dichroism (CD) spectroscopy is a widely used method for examining the structure, folding and conformational changes of proteins. A new online CD analysis server (DichroMatch) has been developed for identifying proteins with similar spectral characteristics by detecting possible structurally and functionally related proteins and homologues. DichroMatch includes six different methods for determining the spectral nearest neighbours to a query protein spectrum and provides metrics of how similar these spectra are and, if corresponding crystal structures are available for the closest matched proteins, information on their secondary structures and fold classifications. By default, DichroMatch uses all the entries in the Protein Circular Dichroism Data Bank (PCDDB) for its comparison set, providing the broadest range of publicly available protein spectra to match with the unknown protein. Alternatively, users can download or create their own specialized data sets, thereby enabling comparisons between the structures of related proteins such as wild-type versus mutants or homologues or a series of spectra of the same protein under different conditions. The DichroMatch server is freely available at http://dichromatch.cryst.bbk.ac.uk
Superconductive magnetic-field-trapping device
An apparatus which enables the establishment of a magnetic field in air that has the same intensity as the ones in ferromagnetic materials is described. The apparatus is comprised of a core of ferromagnetic material and is surrounded by a cylinder made of a material that has superconducting properties when cooled below a critical temperature. A method is provided for producing a magnetic field through the ferromagnetic core. The core can also be split and pulled apart when it is required that the center of the cavity be left empty
Flight and wind-tunnel comparisons of the inlet-airframe interaction of the F-15 airplane
The design of inlets and nozzles and their interactions with the airplane which may account for a large percentage of the total drag of modern high performance aircraft is discussed. The inlet/airframe interactions program and the flight tests conducted is described. Inlet drag and lift data from a 7.5% wind-tunnel model are compared with data from an F-15 airplane with instrumentation to match the model. Pressure coefficient variations with variable cowl angles, capture ratios, examples of flow interactions and angles of attack are for Mach numbers of 0.6, 0.9, 1.2, and 1.5 are presented
Traumatic Myiasis Caused by an Association of <i>Sarcophaga tibialis</i> (Diptera: Sarcophagidae) and <i>Lucilia sericata</i> (Diptera: Calliphoridae) in a Domestic Cat in Italy
received: 2015-05-07 accepted: 2015-06-30 published: 2015-08-25© 2015, Korean Society for Parasitology and Tropical Medicine
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. The attached file is the published version of the article.© 2015, Korean Society for Parasitology and Tropical Medicine
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. The attached file is the published version of the article
A Review of Energy and Environmental Policy for Offshore Liquefied Natural Gas (LNG) Terminals
The Maritime Transportation Security Act of 2002 amended the Deepwater Port Act of 1974 allowing energy industries to construct offshore liquefied natural gas (LNG) terminals. The industry friendly amendments weakened environmental regulations resulting in quick approval of several terminals that utilize environmentally damaging open-loop regasification systems. The objectives of this case study are to determine what influences national energy security and energy industries have in offshore LNG policy development and what energy policy tactics are utilized by the George W. Bush administration. Senate testimony, industry publications, federal legislation, and permit case studies reveal the prominence of concerns for national energy security and industry complaints over terminal siting and permitting process delays. An eco-Marxist argument is visible when the Bush Administration centralizes the policy process by working cooperatively with energy industry elites to promote energy development and attempts to limit the role of certain federal and state agencies and citizens
A Review of Energy and Environmental Policy for Offshore Liquefied Natural Gas (LNG) Terminals
The Maritime Transportation Security Act of 2002 amended the Deepwater Port Act of 1974 allowing energy industries to construct offshore liquefied natural gas (LNG) terminals. The industry friendly amendments weakened environmental regulations resulting in quick approval of several terminals that utilize environmentally damaging open-loop regasification systems. The objectives of this case study are to determine what influences national energy security and energy industries have in offshore LNG policy development and what energy policy tactics are utilized by the George W. Bush administration. Senate testimony, industry publications, federal legislation, and permit case studies reveal the prominence of concerns for national energy security and industry complaints over terminal siting and permitting process delays. An eco-Marxist argument is visible when the Bush Administration centralizes the policy process by working cooperatively with energy industry elites to promote energy development and attempts to limit the role of certain federal and state agencies and citizens
Young star clusters in interacting galaxies - NGC 1487 and NGC 4038/4039
We estimate the dynamical masses of several young (~10 Myr) massive star
clusters in two interacting galaxies, NGC 4038/4039 ("The Antennae") and NGC
1487, under the assumption of virial equilibrium. These are compared with
photometric mass estimates from K-band photometry and assuming a standard
Kroupa IMF. The clusters were selected to have near-infrared colors dominated
by red supergiants, and hence to be old enough to have survived the earliest
phases of cluster evolution when the interstellar medium is rapidly swept out
from the cluster, supported by the fact that there is no obvious Halpha
emission associated with the clusters. All but one of the Antennae clusters
have dynamical and photometric mass estimates which are within a factor ~2 of
one another, implying both that standard IMFs provide a good approximation to
the IMF of these clusters, and that there is no significant extra-virial
motion, as would be expected if they were rapidly dispersing. These results
suggest that almost all of the Antennae clusters in our sample have survived
the gas removal phase as bound or marginally bound objects. Two of the three
NGC 1487 clusters studied here have M_dyn estimates which are significantly
larger than the photometric mass estimates. At least one of these two clusters,
and one in the Antennae, may be actively in the process of dissolving. The
process of dissolution contributes a component of non-virial motion to the
integrated velocity measurements, resulting in an estimated M_dyn which is too
high relative to the amount of measured stellar light. The dissolution
candidates in both galaxies are amongst the clusters with the lowest
pressures/densities measured in our sample.Comment: 17 pages, 14 Figures, A&A accepte
Transcription factors involved in retinogenesis are co-opted by the circadian clock following photoreceptor differentiation
The circadian clock is known to regulate a wide range of physiological and cellular processes, yet remarkably little is known about its role during embryo development. Zebrafish offer a unique opportunity to explore this issue, not only because a great deal is known about key developmental events in this species, but also because the clock starts on the very first day of development. In this study, we identified numerous rhythmic genes in zebrafish larvae, including the key transcriptional regulators neurod and cdx1b, which are involved in neuronal and intestinal differentiation, respectively. Rhythmic expression of neurod and several additional transcription factors was only observed in the developing retina. Surprisingly, these rhythms in expression commenced at a stage of development after these transcription factors are known to have played their essential role in photoreceptor differentiation. Furthermore, this circadian regulation was maintained in adult retina. Thus, once mature photoreceptors are formed, multiple retinal transcription factors fall under circadian clock control, at which point they appear to play a new and important role in regulating rhythmic elements in the phototransduction pathway
Dynamical Masses of Young Star Clusters in NGC 4038/4039
In order to estimate the masses of the compact, young star clusters in the
merging galaxy pair, NGC 4038/4039 (``the Antennae''), we have obtained medium
and high resolution spectroscopy using ISAAC on VLT-UT1 and UVES on VLT-UT2 of
five such clusters. The velocity dispersions were estimated using the stellar
absorption features of CO at 2.29 microns and metal absorption lines at around
8500 \AA, including lines of the Calcium Triplet. The size scales and light
profiles were measured from HST images. From these data and assuming Virial
equilibrium, we estimated the masses of five clusters. The resulting masses
range from 6.5 x 10^5 to 4.7 x 10^6 M_sun. These masses are large, factor of a
few to more than 10 larger than the typical mass of a globular cluster in the
Milky Way. The mass-to-light ratios for these clusters in the V- and K-bands in
comparison with stellar synthesis models suggest that to first order the IMF
slopes are approximately consistent with Salpeter for a mass range of 0.1 to
100 M_sun. However, the clusters show a significant range of possible IMF
slopes or lower mass cut-offs and that these variations may correlate with the
interstellar environment of the cluster. Comparison with the results of
Fokker-Planck simulations of compact clusters with properties similar to the
clusters studied here, suggest that they are likely to be long-lived and may
lose a substantial fraction of their total mass. This mass loss would make the
star clusters obtain masses which are comparable to the typical mass of a
globular cluster.Comment: 16 pages, 12 figures, A&A accepte
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