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1.
PAPER CURRENT
Non-Hermitian Lagrangian for Quasirelativistic Fermions (2014)
Publication Date: 2014-12-22
Description: We present a Lorentz-symmetry violating Lagrangian for free fermions, which is local but not Hermitian,whereas the correspondingHamiltonian is Hermitian but not local. A specific feature of the model is that the dispersion relation is relativisticin both the IR and the UV but not in an intermediate regime, set by a given mass scale. The consistency of the model is shown by the study ofproperties expected in analogy with the Dirac Lagrangian.
Print ISSN: 1687-9120
Electronic ISSN: 1687-9139
Topics: Mathematics , Physics
Published by Hindawi
2.
PAPER CURRENT
ENSO Teleconnection Pattern Changes over the Southeastern United States under a Climate Change Scenario in CMIP5 Models (2014)
Publication Date: 2014-12-22
Description: A strong teleconnection exists between the sea surface temperature (SST) over the tropical Pacific and the winter precipitation in the southeastern United States (SE US). This feature is adopted to validate the fidelity of Coupled Model Intercomparison Project Phase 5 (CMIP5) in this study. In addition, the authors examine whether the teleconnection pattern persists in the future under a global warming scenario. Generally, most of the eight selected models show a positive correlation between November SST over Niño 3 region and December–February (DJF) mean daily precipitation anomalies over the SE US, consistent with the observation. However, the models with poor realization of skewness of Niño indices fail to simulate the realistic teleconnection pattern in the historical simulation. In the Representative Concentration Pathways 8.5 (RCP8.5) run, all of the models maintain positive and slightly increased correlation patterns. It is noteworthy that the region with strong teleconnection pattern shifts northward in the future. Increased variance of winter precipitation due to the SST teleconnection is shown over Alabama and Georgia rather than over Florida under the RCP8.5 scenario in most of the models, differing from the historical run in which the precipitation in Florida is the most attributable to the eastern Pacific SST.
Print ISSN: 1687-9309
Electronic ISSN: 1687-9317
Topics: Geosciences , Physics
Published by Hindawi
3.
PAPER CURRENT
Publication Date: 2014-12-22
Description: Publication date: 1 January 2015 Source:Agriculture, Ecosystems & Environment, Volume 199
Print ISSN: 0167-8809
Electronic ISSN: 1873-2305
Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Published by Elsevier
4.
PAPER CURRENT
Effervescent-salt-assisted dispersive micro-solid-phase extraction using mesoporous hybrid materials coupled with ultra-performance liquid chromatography for the determination of trace-level compounds in complicated plant preparations (2014)
Publication Date: 2014-12-22
Description: Abstract A novel effervescent-salt-assisted dispersive micro-solid-phase extraction using mesoporous hybrid materials was developed for the extraction of minute traces of constituents in complicated plant preparations. In this study, a special tablet containing carbon dioxide sources (sodium dihydrogenphosphate and sodium carbonate) and the sorbent (mesoporous hybrid materials) was prepared. The effects of different parameters influencing the extraction efficiency such as the concentration of salts, the type and concentration of mesoporous material, pH of diluent, and desorption solvents were investigated and optimized. Results show that the proposed method using green solvents (water) as extraction solutions required low consumption of sample amount and obtained high enrichment efficiency. Moreover, under optimized conditions, the tested tanshinones exhibited good linearity (r 2 > 0.994) in the concentration range of 0.5 to 80 ng mL−1. The limits of detection values were lower than 0.0803 pg using UV–visible detection. The developed method was successfully applied for the analysis of trace tanshinones in compound Danshen dripping pill and Danqi tablet samples. Graphical Abstract Schematic of effervescent salts assisted dispersive micro-solid-phase extraction using mesoporoushybrid materials
Print ISSN: 1618-2642
Topics: Chemistry and Pharmacology
Published by Springer
5.
PAPER CURRENT
Identification and phylogenetic relationship of Mannheimia varigena using the 16S rRNA subunit and the rpoB gene (2014)
Publication Date: 2014-12-22
Description: Abstract The objective of this work was to identify Mannheimia varigena strains in samples of bovine nasal exudates and bovine pneumonic lung using the API 20E bacterial identification system, 16S rRNA gene sequencing, and rpoB gene sequencing, as well as the establishment of the phylogenetic relationship with the Pasteurellaceae family. The API 20E identification system determined the strains correspond to the genus Mannheimia spp. Sequencing of the 16S rRNA gene showed 100 % homology with Mannheimia varigena and sequencing of the rpoB gene showed 99 % homology with M. varigena; phylogenetic analysis confirmed the isolates belong to M. varigena by locating the isolates in a separate and independent clade. In contrast to sequences from bovine pneumonic lung, the amino acid sequence of the rpoB gene from bovine nasal exudates showed two different mutations, the changing of aspartate for asparagine at position 158 and alanine for aspartate at position 160. These mutations are non-synonymous changes that have not been reported in the Mannheimia complex or related species.
Print ISSN: 1590-4261
Electronic ISSN: 1869-2044
Topics: Biology
Published by Springer
6.
PAPER CURRENT
LARGE-SCALE SHIELDING STRUCTURES IN LOW EARTH ORBITS (2014)
Publication Date: 2014-12-22
Description: Publication date: Available online 20 December 2014 Source:Acta Astronautica Author(s): D.V. Panov , M.V. Silnikov , A.I. Mikhaylin , I.S. Rubzov , V.B. Nosikov , E.Yu. Minenko , D.A. Murtazin The problems involved in the design-engineering digital simulation of large-size transformable-screen constructions for protecting spacecraft and equipment from space debris and meteoroids were considered. The engineering principles used to improve the design and efficiency of protective screens are presented. The use of embedded matrix transducers located all over the composite material used for armor tiles is proposed for the construction of protective clad screens; this approach enables efficient detection of damaged areas of the protective screen, the assessment of the level of damage, and the prediction of damage to spacecraft and equipment structures.
Print ISSN: 0094-5765
Electronic ISSN: 1879-2030
Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
7.
PAPER CURRENT
Alkane production by the marine cyanobacterium Synechococcus sp. NKBG15041c possessing the α-olefin biosynthesis pathway (2014)
Publication Date: 2014-12-22
Description: Abstract The production of alkanes in a marine cyanobacterium possessing the α-olefin biosynthesis pathway was achieved by introducing an exogenous alkane biosynthesis pathway. Cyanobacterial hydrocarbons are synthesized via two separate pathways: the acyl-acyl carrier protein (ACP) reductase/aldehyde-deformylating oxygenase (AAR/ADO) pathway for the alkane biosynthesis and the α-olefin synthase (OLS) pathway for the α-olefin biosynthesis. Coexistence of these pathways has not yet been reported. In this study, the marine cyanobacterium Synechococcus sp. NKBG15041c was shown to produce α-olefins similar to those of Synechococcus sp. PCC7002 via the α-olefin biosynthesis pathway. The production of heptadecane in Synechococcus sp. NKBG15041c was achieved by expressing the AAR/ADO pathway genes from Synechococcus elongatus PCC 7942. The production yields of heptadecane in Synechococcus sp. NKBG15041c varied with the expression level of the aar and ado genes. The maximal yield of heptadecane was 4.2 ± 1.2 μg/g of dried cell weight in the transformant carrying a homologous promoter. Our results also suggested that the effective activation of ADO may be more important for the enhancement of alkane production by cyanobacteria.
Print ISSN: 0175-7598
Electronic ISSN: 1432-0614
Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
Published by Springer
8.
PAPER CURRENT
Effect of carbon content on nanostructural, mechanical and electrochemical characteristics of self-organized nc-ZrCN/a-CNx nanocomposite films (2014)
Publication Date: 2014-12-22
Description: Publication date: 1 February 2015 Source:Applied Surface Science, Volume 327 Author(s): Fuzeng Zhou , Kaihu Fu , Bin Liao , Jingjing Yu , Chaolin Yang , Xu Zhang The nanocomposite nc-ZrCN/a-CN x films with a carbon content varying from 34 to 61at.% were deposited by filtered cathodic vacuum arc technique (FCVA) under different C2H2/N2 reactive gas flows. The effect of different carbon contents on compositional, nanostructural characteristics of nanocomposite nc-ZrCN/a-CN x films was investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscope (TEM), Raman scattering spectroscopy (Raman) and X-ray photoelectron spectroscopy (XPS). Results showed that nanocomposite nc-ZrCN/a-CN x films were composed of about 8nm sized ZrCN nanocrystalline embedded in different amount of a-CN x amorphous matrix. Mechanical properties of nanocomposite nc-ZrCN/a-CN x films showed a significant dependency on thickness of a-CN x matrix. Nanocomposite nc-ZrCN/a-CN x film reached the highest hardness (41GPa) and reduced modulus (320GPa) when the thickness of a-CN x matrix was around 0.4nm. Nanocomposite nc-ZrCN/a-CN x film at higher carbon content has lower friction coefficient (0.2) and better wear resistance. The nanocomposite films possess lower I corr and higher R p values than the single phase film.
Print ISSN: 0169-4332
Topics: Physics
Published by Elsevier
9.
PAPER CURRENT
Thermal and optical characterization of Ge–Sn–Se glass system (2014)
Publication Date: 2014-12-22
Description: Abstract Thermal and optical characterization of Ge x Sn10Se90−x (x = 14, 18, 22, 26) glasses has been carried out using differential scanning calorimetry and UV–VIS–NIR spectroscopy, respectively. Bulk samples were prepared using conventional melt quenching technique. Amorphous nature of the prepared samples was confirmed using X-ray diffraction. The transmission spectra of as deposited films, for normal incidence, were recorded in the range 400–2,500 nm. Optical constants such as absorption coefficient, refractive index and extinction coefficients have been determined using the envelope method. Dispersion of refractive index has been analyzed using single-effective oscillator model. Optical band gap has been measured using Tauc plots. Effect of composition variation on thermal and optical properties has been discussed in view of chemical bond approach.
Print ISSN: 0947-8396
Electronic ISSN: 1432-0630
Topics: Technology , Physics
Published by Springer
10.
PAPER CURRENT
Ablation of oxide materials and production of nanopowders by ytterbium fiber laser (2014)
Publication Date: 2014-12-22
Description: Abstract In this paper, laser radiation action on Nd3+:Y2O3 targets having the absorption 13–1.7 × 103 cm−1 is studied. During the experiment, we used the ytterbium fiber laser, which can operate both in continuous and pulse mode with the pulse duration time 0.1–1.9 ms. Laser radiation power was 200–700 W, and power density was (0.2–1.2) × 106 W/cm2. We found out the spike behavior of laser plume luminescence, large statistical variability of delay time of laser plume appearance, and spallation of front surface of the target. Aiming to explain these facts, we developed the numeric model of radiation impact on substance with non-uniform absorption coefficient. We found out the optimal laser oblation mode for nanopowder production. At laser power of 700 W, we received Nd3+:Y2O3 nanopowder with productivity up to 27 g/h. Average size of nanoparticles is 13.6 nm, and their phase is monoclinic.
Print ISSN: 0947-8396
Electronic ISSN: 1432-0630
Topics: Technology , Physics
Published by Springer