3,630 research outputs found
Electroweak phase transition in the economical 3-3-1 model
We consider the EWPT in the economical 3-3-1 (E331) model. Our analysis shows
that the EWPT in the model is a sequence of two first-order phase transitions,
at the TeV scale and at the
GeV scale. The EWPT is triggered by the new
bosons and the exotic quarks; its strength is about if the mass ranges
of these new particles are . The
EWPT is strengthened by only the new bosons; its
strength is about if the mass parts of , and
are in the ranges . The
contributions of and to the strengths of both EWPTs may
make them sufficiently strong to provide large deviations from thermal
equilibrium and B violation necessary for baryogenesis.Comment: 17 pages, 9 figure
Strong efficiency improvement of SOI-LEDs through carrier confinement
Contemporary silicon light-emitting diodes in silicon-on-insulator (SOI) technology suffer from poor efficiency compared to their bulk-silicon counterparts. In this letter, we present a new device structure where the carrier injection takes place through silicon slabs of only a few nanometer thick. Its external quantum efficiency of 1.4 • 10−4 at room temperature, with a spectrum peaking at 1130 nm, is almost two orders higher than reported thus far on SOI. The structure diminishes the dominant role of nonradiative recombination at the n+ and p+contacts, by confining the injected carriers in an SOI peninsula.\ud
With this approach, a compact infrared light source can be fabricated using standard semiconductor processing steps.\u
FullSWOF_Paral: Comparison of two parallelization strategies (MPI and SKELGIS) on a software designed for hydrology applications
In this paper, we perform a comparison of two approaches for the
parallelization of an existing, free software, FullSWOF 2D (http://www.
univ-orleans.fr/mapmo/soft/FullSWOF/ that solves shallow water equations for
applications in hydrology) based on a domain decomposition strategy. The first
approach is based on the classical MPI library while the second approach uses
Parallel Algorithmic Skeletons and more precisely a library named SkelGIS
(Skeletons for Geographical Information Systems). The first results presented
in this article show that the two approaches are similar in terms of
performance and scalability. The two implementation strategies are however very
different and we discuss the advantages of each one.Comment: 27 page
Influence of dislocation loops on the near infrared light emission from silicon diodes
The infrared light emission of forward-biased silicon diodes is studied. Through ion implantation and anneal, dislocation loops were created near the diode junction. These loops suppress the light emission at the band-to-band peak around 1.1 μm. The so-called D1 line at 1.5 μm is strongly enhanced by these dislocation loops. We report a full study of photoluminescence and electroluminescence of these diodes. The results lead to new insights for the manufacturing approach of practical infrared light sources in integrated circuit
Electrochemical reduction of CO2 to methanol
An efficient method to convert CO2 to fuels using renewable energy could displace crude oil without increasing CO2 emission and provide high-density energy storage reservoirs similar to liquid fuels or batteries. Although photoelectrochemical conversion of CO2 is possible, solar-to-fuel efficiencies are lower than the combination of conventional photovoltaics (up to 40% efficiency) and electrochemical cells (up to 80% Faradaic efficiency). In the electrochemical case, electrical energy from renewable sources may be converted to hydrocarbons or alcohols using electrocatalysts. The direct reduction of CO2 to CH3OH is known to occur at several types of electrocatalysts including oxidized Cu electrodes. In this thesis, we first examine the yield behavior of an electrodeposited cuprous oxide thin film and explore relationships between surface chemistry and reaction behavior relative to air-oxidized and anodized Cu electrodes. CH3OH yields and Faradaic efficiencies observed at cuprous oxide electrodes are remarkably higher than air-oxidized or anodized Cu electrodes suggesting Cu(I) species may play a critical role in selectivity to CH3OH. Experimental results also show CH3OH yields are dynamic and the copper oxides are reduced to metallic Cu in a simultaneous process. In order to improve CH3OH activity and electrode surface’s stability, single crystal ZnO (10-10) is considered as a support since ZnO support are well known for methanol synthesis in an industrial hydrogenation reaction scale. Although experimental conditions pose challenging barriers to repeatability, Infrared Spectroscopy and yields suggest the oxide may provide stable surfaces with selectivity to CH3OH. Yield behavior is discussed in comparison with photoelectrochemical and hydrogenation reactions where the improved stability of Cu(I) species may allow relatively constant CH3OH generation
Effects of yeast extract and methyl jasmonate on the enhancement of solasodine biosynthesis in cell cultures of Solanum hainanense Hance
In this work, the effects of the elicitors methyl jasmonate (MeJA) and yeast extract (YE) on the growth and solasodine production of Solanum hainanense cells were investigated. The results showed that various concentrations of MeJA (50-250 µM) and YE (1-4 g/L) have different eliciting influences. The increase of solasodine content induced by the elicitation of 3 g/L of YE and 50 µM of MeJA at the beginning of cell culture was about 1.9- and 1.3-fold, respectively, as compared with that of the non-elicitated cells. In general, YE (biotic elicitor) was more effective in enhancing solasodine production than MeJA (abiotic elicitor)
VNINDEX INDEX: A VIEW FROM QUANTITATIVE ANALYSIS
The financial strategy towards 2030 in Decision no. 368/QD-TTg enacted on 21/3/2022 by the Vietnam Prime Minister had set developmental goals for the stock market to become a channel to promote mid-and-long term capital raising for the economy, to continue changing the structure to be more appropriate for the monetary, the capital, the stock, and the bonds market. In the past two years, the stock market in Vietnam has manifested impressive growth. A prime example is the active growth of private investors. However, many challenges and loopholes still exist in the stock market. The stock market is a special market as the fluctuation of the VN-index index is affected by many factors including the expectations of the investor. When the market shows trends of increases in points then investors expect the next session to grow as well, leading to a rise in sales even for stocks with inflating costs, thus the VNindex will increase and vice versa. The structure of the econometric is utilized to assess the impacts of the VN-index of the previous month on the index of the following month on the Vietnamese stock market in the period from January 2019 to May 2022. The conclusion of the quantitative analysis shows that if the VN-index of the previous month increases by 1% then the VNindex of the following month will increase by 0.965% or vice versa. From the results of the analysis, the research team has proposed a few discussion points intending to stabilize the stock market in the upcoming time and develop the market according to the financial strategy towards 2030 in Decision no. 368/QD-TTg by the Vietnam Prime Ministe
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