2,876 research outputs found
AKARI-CAS --- Online Service for AKARI All-Sky Catalogues
The AKARI All-Sky Catalogues are an important infrared astronomical database
for next-generation astronomy that take over the IRAS catalog. We have
developed an online service, AKARI Catalogue Archive Server (AKARI-CAS), for
astronomers. The service includes useful and attractive search tools and visual
tools.
One of the new features of AKARI-CAS is cached SIMBAD/NED entries, which can
match AKARI catalogs with other catalogs stored in SIMBAD or NED. To allow
advanced queries to the databases, direct input of SQL is also supported. In
those queries, fast dynamic cross-identification between registered catalogs is
a remarkable feature. In addition, multiwavelength quick-look images are
displayed in the visualization tools, which will increase the value of the
service.
In the construction of our service, we considered a wide variety of
astronomers' requirements. As a result of our discussion, we concluded that
supporting users' SQL submissions is the best solution for the requirements.
Therefore, we implemented an RDBMS layer so that it covered important
facilities including the whole processing of tables. We found that PostgreSQL
is the best open-source RDBMS products for such purpose, and we wrote codes for
both simple and advanced searches into the SQL stored functions. To implement
such stored functions for fast radial search and cross-identification with
minimum cost, we applied a simple technique that is not based on dividing
celestial sphere such as HTM or HEALPix. In contrast, the Web application layer
became compact, and was written in simple procedural PHP codes. In total, our
system realizes cost-effective maintenance and enhancements.Comment: Yamauchi, C. et al. 2011, PASP..123..852
Advanced Two-Dimensional Heterojunction Photocatalysts of Stoichiometric and Non-Stoichiometric Bismuth Oxyhalides with Graphitic Carbon Nitride for Sustainable Energy and Environmental Applications
Semiconductor-based photocatalysis has been identified as an encouraging approach for solving the two main challenging problems, viz., remedying our polluted environment and the generation of sustainable chemical energy. Stoichiometric and non-stoichiometric bismuth oxyhalides (BiOX and BixOyXz where X = Cl, Br, and I) are a relatively new class of semiconductors that have attracted considerable interest for photocatalysis applications due to attributes, viz., high stability, suitable band structure, modifiable energy bandgap and two-dimensional layered structure capable of generating an internal electric field. Recently, the construction of heterojunction photocatalysts, especially 2D/2D systems, has convincingly drawn momentous attention practicably owing to the productive influence of having two dissimilar layered semiconductors in face-to-face contact with each other. This review has systematically summarized the recent progress on the 2D/2D heterojunction constructed between BiOX/BixOyXz with graphitic carbon nitride (g-C3N4). The band structure of individual components, various fabrication methods, different strategies developed for improving the photocatalytic performance and their applications in the degradation of various organic contaminants, hydrogen (H2) evolution, carbon dioxide (CO2) reduction, nitrogen (N2) fixation and the organic synthesis of clean chemicals are summarized. The perspectives and plausible opportunities for developing high performance BiOX/BixOyXz-g-C3N4 heterojunction photocatalysts are also discussed
Nitrogen doping of TiO2 photocatalyst forms a second eg state in the Oxygen (1s) NEXAFS pre-edge
Close inspection of the pre-edge in oxygen near-edge x-ray absorption fine
structure spectra of single step, gas phase synthesized titanium oxynitride
photocatalysts with 20 nm particle size reveals an additional eg resonance in
the VB that went unnoticed in previous TiO2 anion doping studies. The relative
spectral weight of this Ti(3d)-O(2p) hybridized state with respect to and
located between the readily established t2g and eg resonances scales
qualitatively with the photocatalytic decomposition power, suggesting that this
extra resonance bears co-responsibility for the photocatalytic performance of
titanium oxynitrides at visible light wavelengths
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Implementation of earlier antibiotic administration in patients with severe sepsis and septic shock in Japan: a descriptive analysis of a prospective observational study.
BACKGROUND: Time to antibiotic administration is a key element in sepsis care; however, it is difficult to implement sepsis care bundles. Additionally, sepsis is different from other emergent conditions including acute coronary syndrome, stroke, or trauma. We aimed to describe the association between time to antibiotic administration and outcomes in patients with severe sepsis and septic shock in Japan. METHODS: This prospective observational study enrolled 1184 adult patients diagnosed with severe sepsis based on the Sepsis-2 criteria and admitted to 59 intensive care units (ICUs) in Japan between January 1, 2016, and March 31, 2017, as the sepsis cohort of the Focused Outcomes Research in Emergency Care in Acute Respiratory Distress Syndrome, Sepsis and Trauma (FORECAST) study. We compared the characteristics and in-hospital mortality of patients administered with antibiotics at varying durations after sepsis recognition, i.e., 0-60, 61-120, 121-180, 181-240, 241-360, and 361-1440āmin, and estimated the impact of antibiotic timing on risk-adjusted in-hospital mortality using the generalized estimating equation model (GEE) with an exchangeable, within-group correlation matrix, with "hospital" as the grouping variable. RESULTS: Data from 1124 patients in 54 hospitals were used for analyses. Of these, 30.5% and 73.9% received antibiotics within 1āh and 3āh, respectively. Overall, the median time to antibiotic administration was 102āmin [interquartile range (IQR), 55-189]. Compared with patients diagnosed in the emergency department [90āmin (IQR, 48-164āmin)], time to antibiotic administration was shortest in patients diagnosed in ICUs [60āmin (39-180āmin)] and longest in patients transferred from wards [120āmin (62-226)]. Overall crude mortality was 23.4%, where patients in the 0-60āmin group had the highest mortality (28.0%) and a risk-adjusted mortality rate [28.7% (95% CI 23.3-34.1%)], whereas those in the 61-120āmin group had the lowest mortality (20.2%) and risk-adjusted mortality rates [21.6% (95% CI 16.5-26.6%)]. Differences in mortality were noted only between the 0-60āmin and 61-120āmin groups. CONCLUSIONS: We could not find any association between earlier antibiotic administration and reduction in in-hospital mortality in patients with severe sepsis
Robustness of a local Fermi Liquid against Ferromagnetism and Phase Separation
We study the properties of Fermi Liquids with the microscopic constraint of a
local self-energy. In this case the forward scattering sum-rule imposes strong
limitations on the Fermi-Liquid parameters, which rule out any Pomeranchek
instabilities. For both attractive and repulsive interactions, ferromagnetism
and phase separation are suppressed. Superconductivity is possible in an s-wave
channel only. We also study the approach to the metal-insulator transition, and
find a Wilson ratio approaching 2. This ratio and other properties of
Sr_{1-x}La_xTiO_3 are all consistent with the local Fermi Liquid scenario.Comment: 4 pages (twocolumn format), can compile with or without epsf.sty
latex style file -- Postscript files: fig1.ps and fig2.p
On the optical properties of Ag^{+15} ion-beam irradiated TiO_{2} and SnO_{2} thin films
The effects of 200-MeV Ag^{+15} ion irradiation on the optical properties of
TiO_{2} and SnO_{2} thin films prepared by using the RF magnetron sputtering
technique were investigated. These films were characterized by using UV-vis
spectroscopy, and with increasing irradiation fluence, the transmittance for
the TiO_{2} films was observed to increase systematically while that for
SnO_{2} was observed to decrease. Absorption spectra of the irradiated samples
showed minor changes in the indirect bandgap from 3.44 to 3.59 eV with
increasing irradiation fluence for TiO_{2} while significant changes in the
direct bandgap from 3.92 to 3.6 eV were observed for SnO_{2}. The observed
modifications in the optical properties of both the TiO_{2} and the SnO_{2}
systems with irradiation can be attributed to controlled structural
disorder/defects in the system.Comment: 6 pages, ICAMD-201
A novel three-unit tRNA splicing endonuclease found in ultrasmall Archaea possesses broad substrate specificity
tRNA splicing endonucleases, essential enzymes found in Archaea and Eukaryotes, are involved in the processing of pre-tRNA molecules. In Archaea, three types of splicing endonuclease [homotetrameric: Ī±4, homodimeric: Ī±2, and heterotetrameric: (Ī±Ī²)2] have been identified, each representing different substrate specificity during the tRNA intron cleavage. Here, we discovered a fourth type of archaeal tRNA splicing endonuclease (Īµ2) in the genome of the acidophilic archaeon Candidatus Micrarchaeum acidiphilum, referred to as ARMAN-2 and its closely related species, ARMAN-1. The enzyme consists of two duplicated catalytic units and one structural unit encoded on a single gene, representing a novel three-unit architecture. Homodimeric formation was confirmed by cross-linking assay, and site-directed mutagenesis determined that the conserved L10-pocket interaction between catalytic and structural unit is necessary for the assembly. A tRNA splicing assay reveal that Īµ2 endonuclease cleaves both canonical and non-canonical bulgeāhelixābulge motifs, similar to that of (Ī±Ī²)2 endonuclease. Unlike other ARMAN and Euryarchaeota, tRNAs found in ARMAN-2 are highly disrupted by introns at various positions, which again resemble the properties of archaeal species with (Ī±Ī²)2 endonuclease. Thus, the discovery of Īµ2 endonuclease in an archaeon deeply branched within Euryarchaeota represents a new example of the coevolution of tRNA and their processing enzymes
Self-cleaning and colour-preserving efficiency of photocatalytic concrete: case study of the Jubilee Church in Rome
The Jubilee Church in the south-eastern outskirts of Rome is one of the first buildings constructed with super white reinforced concrete with self-cleaning photocatalytic cement. However, 16 years after the opening of the building, the self-cleaning and colour-preserving properties arising from the titania particles (TiO2) within the concrete mix are not meeting the design requirements and the concrete is showing premature evidence of decay. While the form of the decay is affecting the appearance of the building and not its structural soundness, the ageing pattern of the building's components is resulting in a high maintenance cost, one not easily affordable within the ordinary budget supported by a small parish. This study comprises the first comprehensive step in understanding the causes of the accelerated ageing pattern of the concrete, highlighting methods to improve the long-term durability of the concrete and therefore reduce the cost of its maintenance. Moreover, this research offered the opportunity to test the durability and the effectiveness of the TiO2 in the real conditions on an actual building featuring non-standard geometries. The findings highlight how the ageing pattern directly connects with the geometry of the building and inadequate consideration of the local weathering at the design stage
Auction-based approach to resolve the scheduling problem in the steel making process
Steel production is an extremely complex process and determining coherent schedules for the wide variety of production steps in a dynamic environment, where disturbances frequently occur, is a challenging task. In the steel production process, the blast furnace continuously produces liquid iron, which is transformed into liquid steel in the melt shop. The majority of the molten steel passes through a continuous caster to form large steel slabs, which are rolled into coils in the hot strip mill. The scheduling system of these processes has very different objectives and constraints, and operates in an environment where there is a substantial quantity of real-time information concerning production failures and customer requests. The steel making process, which includes steel making followed by continuous casting, is generally the main bottleneck in steel production. Therefore, comprehensive scheduling of this process is critical to improve the quality and productivity of the entire production system. This paper addresses the scheduling problem in the steel making process. The methodology of winner determination using the combinatorial auction process is employed to solve the aforementioned problem. In the combinatorial auction, allowing bidding on a combination of assets offers a way of enhancing the efficiency of allocating the assets. In this paper, the scheduling problem in steel making has been formulated as a linear integer program to determine the scheduling sequence for different charges. Bids are then obtained for sequencing the charges. Next, a heuristic approach is used to evaluate the bids. The computational results show that our algorithm can obtain optimal or near-optimal solutions for combinatorial problems in a reasonable computation time. The proposed algorithm has been verified by a case study
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