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Modification and Validation of an Automotive Data Processing Unit, Compessed Video System, and Communications Equipment
The primary purpose of the "modification and validation of an automotive data processing unit (DPU), compressed video system, and communications equipment" cooperative research and development agreement (CRADA) was to modify and validate both hardware and software, developed by Scientific Atlanta, Incorporated (S-A) for defense applications (e.g., rotary-wing airplanes), for the commercial sector surface transportation domain (i.e., automobiles and trucks). S-A also furnished a state-of-the-art compressed video digital storage and retrieval system (CVDSRS), and off-the-shelf data storage and transmission equipment to support the data acquisition system for crash avoidance research (DASCAR) project conducted by Oak Ridge National Laboratory (ORNL). In turn, S-A received access to hardware and technology related to DASCAR. DASCAR was subsequently removed completely and installation was repeated a number of times to gain an accurate idea of complete installation, operation, and removal of DASCAR. Upon satisfactory completion of the DASCAR construction and preliminary shakedown, ORNL provided NHTSA with an operational demonstration of DASCAR at their East Liberty, OH test facility. The demonstration included an on-the-road demonstration of the entire data acquisition system using NHTSA'S test track. In addition, the demonstration also consisted of a briefing, containing the following: ORNL generated a plan for validating the prototype data acquisition system with regard to: removal of DASCAR from an existing vehicle, and installation and calibration in other vehicles; reliability of the sensors and systems; data collection and transmission process (data integrity); impact on the drivability of the vehicle and obtrusiveness of the system to the driver; data analysis procedures; conspicuousness of the vehicle to other drivers; and DASCAR installation and removal training and documentation. In order to identify any operational problems not captured by the systems testing and evaluation, the validation plan also addressed a short-term pilot research program to manipulate DASCAR under operational conditions using "naive" drivers. The effort exercised the fill capabilities of the data acquisition system. ORNL subsequently evaluated and pilot tested the data acquisition system using the validation plan. The plan was implemented in full at the NHTSA East Liberty, OH test facility, and was carried out as a cooperative effort with the Vehicle Research and Test Center staff. ORNL determined the reliability of the sensors and systems by exercising DASCAR For one vehicle type, ORNL evaluated systems reliability over a continuous period of 30 days with particular attention paid to maintenance of calibration and data integrity
Approximation of conformal mappings by circle patterns
A circle pattern is a configuration of circles in the plane whose
combinatorics is given by a planar graph G such that to each vertex of G
corresponds a circle. If two vertices are connected by an edge in G, the
corresponding circles intersect with an intersection angle in .
Two sequences of circle patterns are employed to approximate a given
conformal map and its first derivative. For the domain of we use
embedded circle patterns where all circles have the same radius decreasing to 0
and which have uniformly bounded intersection angles. The image circle patterns
have the same combinatorics and intersection angles and are determined from
boundary conditions (radii or angles) according to the values of (
or ). For quasicrystallic circle patterns the convergence result is
strengthened to -convergence on compact subsets.Comment: 36 pages, 7 figure
Quasi-Equatorial Gravitational Lensing by Spinning Black Holes in the Strong Field Limit
Spherically symmetric black holes produce, by strong field lensing, two
infinite series of relativistic images, formed by light rays winding around the
black hole at distances comparable to the gravitational radius. In this paper,
we address the relevance of the black hole spin for the strong field lensing
phenomenology, focusing on trajectories close to the equatorial plane for
simplicity. In this approximation, we derive a two-dimensional lens equation
and formulae for the position and the magnification of the relativistic images
in the strong field limit. The most outstanding effect is the generation of a
non trivial caustic structure. Caustics drift away from the optical axis and
acquire finite extension. For a high enough black hole spin, depending on the
source extension, we can practically observe only one image rather than two
infinite series of relativistic images. In this regime, additional non
equatorial images may play an important role in the phenomenology.Comment: 13 pages, 9 figures. Improved version with detailed physical
discussio
Identification of differentially expressed small non-coding RNAs in the legume endosymbiont Sinorhizobium meliloti by comparative genomics
Bacterial small non-coding RNAs (sRNAs) are being recognized as novel widespread regulators of gene expression in response to environmental signals. Here, we present the first search for sRNA-encoding genes in the nitrogen-fixing endosymbiont Sinorhizobium meliloti, performed by a genome-wide computational analysis of its intergenic regions. Comparative sequence data from eight related α-proteobacteria were obtained, and the interspecies pairwise alignments were scored with the programs eQRNA and RNAz as complementary predictive tools to identify conserved and stable secondary structures corresponding to putative non-coding RNAs. Northern experiments confirmed that eight of the predicted loci, selected among the original 32 candidates as most probable sRNA genes, expressed small transcripts. This result supports the combined use of eQRNA and RNAz as a robust strategy to identify novel sRNAs in bacteria. Furthermore, seven of the transcripts accumulated differentially in free-living and symbiotic conditions. Experimental mapping of the 5′-ends of the detected transcripts revealed that their encoding genes are organized in autonomous transcription units with recognizable promoter and, in most cases, termination signatures. These findings suggest novel regulatory functions for sRNAs related to the interactions of α-proteobacteria with their eukaryotic hosts
Relativistic theory of elastic deformable astronomical bodies: perturbation equations in rotating spherical coordinates and junction conditions
In this paper, the dynamical equations and junction conditions at the
interface between adjacent layers of different elastic properties for an
elastic deformable astronomical body in the first post-Newtonian approximation
of Einstein theory of gravity are discussed in both rotating Cartesian
coordinates and rotating spherical coordinates. The unperturbed rotating body
(the ground state) is described as uniformly rotating, stationary and
axisymmetric configuration in an asymptotically flat space-time manifold.
Deviations from the equilibrium configuration are described by means of a
displacement field. In terms of the formalism of relativistic celestial
mechanics developed by Damour, Soffel and Xu, and the framework established by
Carter and Quintana the post Newtonian equations of the displacement field and
the symmetric trace-free shear tensor are obtained. Corresponding
post-Newtonian junction conditions at interfaces also the outer surface
boundary conditions are presented. The PN junction condition is an extension of
Wahr's one which is a Newtonian junction conditions without rotating.Comment: Revtex4, 14 page
Unravelling an allochthonous, subaqueously-deposited volcanic-epiclastic to subaerial andesitic lava assemblage in Hong Kong: age, stratigraphy and provenance studies of the Middle Jurassic Tuen Mun Formation
The Middle Jurassic Tuen Mun Formation, Hong Kong, is a fault-bounded block of rare andesitic and related rocks that preserve a snapshot of the developing SE China continental arc system during the late Mesozoic. The forearc depositional setting is considered to have been dominated by an emergent andesitic volcanic massif, which shows a transition to a fluvialdominated volcanic plain, and then to an offshore marine environment. The youngest laser ablation inductively coupled plasma mass spectrometry U–Pb detrital zircon ages obtained from the three packages define a coherent group (n = 396; MSWD = 1.8) suggesting a maximum depositional age of 169.5 ± 0.3 Ma. The dominance of large euhedral and concentrically zoned zircons reflects a common volcanic provenance. Hf isotope data (εHf(t) = 0 to −11) on the youngest representative zircon grains imply derivation of magmas from dominantly recycled crustal sources. The detrital zircon age signatures and Hf isotope data show no indication of magmatic interaction with adjacent late Palaeozoic and Early to Middle Jurassic sedimentary rocks, or Middle Jurassic to Early Cretaceous magmatic rocks of Hong Kong. On the basis of the structural, zircon age and isotope data, the Tuen Mun Formation is interpreted to be an allochthonous block, emplaced in the Hong Kong region during the late Middle Jurassic
Neutron Scattering Study of Crystal Field Energy Levels and Field Dependence of the Magnetic Order in Superconducting HoNi2B2C
Elastic and inelastic neutron scattering measurements have been carried out
to investigate the magnetic properties of superconducting (Tc~8K) HoNi2B2C. The
inelastic measurements reveal that the lowest two crystal field transitions out
of the ground state occurat 11.28(3) and 16.00(2) meV, while the transition of
4.70(9) meV between these two levels is observed at elevated temperatures. The
temperature dependence of the intensities of these transitions is consistent
with both the ground state and these higher levels being magnetic doublets. The
system becomes magnetically long range ordered below 8K, and since this
ordering energy kTN ~ 0.69meV << 11.28meV the magnetic properties in the
ordered phase are dominated by the ground-state spin dynamics only. The low
temperature structure, which coexists with superconductivity, consists of
ferromagnetic sheets of Ho{3+ moments in the a-b plane, with the sheets coupled
antiferromagnetically along the c-axis. The magnetic state that initially forms
on cooling, however, is dominated by an incommensurate spiral antiferromagnetic
state along the c-axis, with wave vector qc ~0.054 A-1, in which these
ferromagnetic sheets are canted from their low temperature antiparallel
configuration by ~17 deg. The intensity for this spiral state reaches a maximum
near the reentrant superconducting transition at ~5K; the spiral state then
collapses at lower temperature in favor of the commensurate antiferromagnetic
state. We have investigated the field dependence of the magnetic order at and
above this reentrant superconducting transition. Initially the field rotates
the powder particles to align the a-b plane along the field direction,
demonstrating that the moments strongly prefer to lie within this plane due to
the crystal field anisotropy. Upon subsequently increasing the field atComment: RevTex, 7 pages, 11 figures (available upon request); Physica
Carbono orgânico dissolvido e biodisponibilidade de N e P como indicadores de qualidade do solo
Nas últimas décadas, qualidade do solo tem se tornado um tópico importante na ciência do solo. Embora esforços consideráveis tenham sido dedicados com o intuito de definir "qualidade do solo", ainda não há um conceito amplamente aceito pela comunidade cientifica. A seleção de índices qualitativos para definir qualidade do solo é uma tarefa extremamente difícil, e diversas propriedades químicas, físicas e biológicas tem sido sugeridas como potenciais indicadores. A matéria orgânica do solo está associada com processos químicos, físicos e biológicos no solo, e, portanto, é considerada um dos melhores indicadores de qualidade do solo. O manejo do solo pode influenciar significativamente a dinâmica do carbono orgânico e o ciclo de N, P, e S. Entretanto, mudanças na concentração total da matéria organica em resposta ao manejo pode ser dificil de ser detectada devido à variabilidade natural do solo. Quando comparada com a matéria orgânica total do solo, a fração mais prontamente disponível, como o carbono orgânico dissolvido (COD), é mais sensível às mudanças no manejo do solo a curto e médio prazo e, portanto, pode ser utilizada como indicador fundamental de qualidade do solo ou das alterações das condições naturais. Embora a fração dissolvida represente apenas uma pequena porção da matéria orgânica total do solo, o COD é móvel no solo e constitui uma importante fonte de C para os microorganismos, podendo facilmente refletir os efeitos de diferentes sistemas de manejo. Inúmeros métodos são utilizados para caracterizar o COD, mas os processos que influenciam sua mineralização e a disponibilidade dos elementos associado com a matéria orgânica (N, P, e S) ainda não são completamente entendidos. Pesquisas futuras devem buscar entender os processos que governam a dinâmica de nutrientes e do COD e como os mesmos afetam a qualidade do solo.Soil quality has become an important issue in soil science. Considerable attempts have been made to define soil quality, but a general concept has not yet been accepted by the scientific community. The selection of quantitative indices for soil quality is extremely difficult, and a considerable number of chemical, physical, and biochemical properties have been suggested as potential indicators of soil quality. Because soil organic matter (SOM) can be associated with different soil chemical, physical and biological processes, it has been widely considered as one of the best soil quality indicator. Land use can significantly influence dynamics of organic carbon and N, P, and S cycle. However, changes in total soil organic carbon (SOC) contents in response to land use may be difficult to detect because of the natural soil variability. In the short to medium term, biological properties and readily decomposable fractions of SOC, such as dissolved organic carbon (DOC), are much more sensitive to soil management than is SOM as a whole, and can be used as a key indicator of soil natural functions. Despite the fact that labile C accounts for a small portion of the total organic matter in the soils, DOC is the most mobile and important C-source for microorganisms, and can easily reflect the effects of land use on soil quality. Although several methods are used to characterize DOC, the factors influencing mineralization and bioavailability of elements associated with organic matter (N, P, and S) remains unclear. Future research should focus on the processes that govern DOC and nutrient dynamics and how they affect soil quality
Theoretical study of electronic Raman scattering of Borocarbide superconductors
The electronic Raman scattering of Borocarbide superconductors is studied
based on the weak coupling theory with -wave gap symmetry. The low energy
behaviors and the relative peak positions can be naturally understood, while
the explanation of the detailed shape of the peak seems to require a
strong inelastic interaction not present in the weak coupling theory.Comment: Revtex 4 file, 9 pages and 5 figure
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