1,321 research outputs found
Strange Particle Production in Nuclear Collisions at CERN-NA49
In order to quantify isospin effects in the comparison of elementary to
nuclear collisions, p-p and n-p interactions have been studied in the NA49
experiment in addition to p-Pb and Pb-Pb reactions. Together with first
measurements of cascade hyperon and Omega production in p-p collisions,
isospin-corrected K/pi ratios and cascade yields are discussed. The
Antiomega/Omega ratio in p-p collisions is found to be less than 0.5 with 95%
confidence level.Comment: 4 pages, 5 figures, Proceedings of "Rencontres de Moriond, 2002
Cogeneration Technology Alternatives Study (CTAS). Volume 1: Summary
Various advanced energy conversion systems that can use coal or coal-derived fuels for industrial cogeneration applications were compared to provide information needed by DOE to establish research and development funding priorities for advanced-technology systems that could significantly advance the use of coal or coal-derived fuels in industrial cogeneration. Steam turbines, diesel engines, open-cycle gas turbines, combined cycles, closed-cycle gas turbines, Stirling engines, phosphoric acid fuel cells, molten carbonate fuel cells, and thermionics were studied with technology advancements appropriate for the 1985-2000 time period. The various advanced systems were compared and evaluated for wide diversity of representative industrial plants on the basis of fuel energy savings, annual energy cost savings, emissions savings, and rate of return on investment as compared with purchasing electricity from a utility and providing process heat with an on-site boiler. Also included in the comparisons and evaluations are results extrapolated to the national level
Coherent control for the spherical symmetric box potential in short and intensive XUV laser fields
Coherent control calculations are presented for a spherically symmetric box
potential for non-resonant two photon transition probabilities. With the help
of a genetic algorithm (GA) the population of the excited states are maximized
and minimized. The external driving field is a superposition of three intensive
extreme ultraviolet (XUV) linearly polarized laser pulses with different
frequencies in the femtosecond duration range. We solved the quantum mechanical
problem within the dipole approximation. Our investigation clearly shows that
the dynamics of the electron current has a strong correlation with the
optimized and neutralizing pulse shape.Comment: 11 Pages 3 Figure
Segmented scintillation detectors with silicon photomultiplier readout for measuring antiproton annihilations
The Atomic Spectroscopy and Collisions Using Slow Antiprotons (ASACUSA)
experiment at the Antiproton Decelerator (AD) facility of CERN constructed
segmented scintillators to detect and track the charged pions which emerge from
antiproton annihilations in a future superconducting radiofrequency Paul trap
for antiprotons. A system of 541 cast and extruded scintillator bars were
arranged in 11 detector modules which provided a spatial resolution of 17 mm.
Green wavelength-shifting fibers were embedded in the scintillators, and read
out by silicon photomultipliers which had a sensitive area of 1 x 1 mm^2. The
photoelectron yields of various scintillator configurations were measured using
a negative pion beam of momentum p ~ 1 GeV/c. Various fibers and silicon
photomultipliers, fiber end terminations, and couplings between the fibers and
scintillators were compared. The detectors were also tested using the
antiproton beam of the AD. Nonlinear effects due to the saturation of the
silicon photomultiplier were seen at high annihilation rates of the
antiprotons.Comment: Copyright 2014 American Institute of Physics. This article may be
downloaded for personal use only. Any other use requires prior permission of
the author and the American Institute of Physics. The following article
appeared in Review of Scientific Instruments, Vol.85, Issue 2, 2014 and may
be found at http://dx.doi.org/10.1063/1.486364
The effect of lipophilicity on the antibacterial activity of some 1-benzylbenzimidazole derivatives
In the present paper, the antibacterial activity of some 1-benzylbenzimidazole derivatives were evaluated against the Gram-negative bacteria Escherichia coli. The minimum inhibitory concentration was determined for all the compounds. Quantitative structure–activity relationship (QSAR) was employed to study the effect of the lipophilicity parameters (log P) on the inhibitory activity. Log P values for the target compounds were experimentally determined by the “shake-flask” method and calculated by using eight different software products. Multiple linear regression was used to correlate the log P values and antibacterial activity of the studied benzimidazole derivatives. The results are discussed based on statistical data. The most acceptable QSAR models for the prediction of the antibacterial activity of the investigated series of benzimidazoles were developed. High agreement between the experimental and predicted inhibitory values was obtained. The results of this study indicate that the lipophilicity parameter has a significant effect on the antibacterial activity of this class of compounds, which simplifies the design of new biologically active molecules
Socioeconomic and Demographic Predictors of Women\u27s First Birth at an Early Age: Evidence from Bangladesh’s Demographic and Health Survey, 2004-2014
Women\u27s health is highly influenced by early childbearing in 95% of developing countries such as Bangladesh. Women who have their first child at an early age receive fewer years of schooling, which also influences their employment life. Women\u27s early age at first birth creates health complications, increases both maternal and child mortality, and prolongs the reproductive duration as well as a country\u27s fertility rate. This is a major social and public health problem around the world. This study aims to investigate the existing situation in Bangladesh and to identify the triggering influencing factors of age at first birth. A cross-sectional study design was implemented in this study, where we used the Bangladesh Demographic and Health Survey data from 2004, 2007, 2011, and 2014. Firstly, to identify different factors associated with first birth at an early age, the bi-variate analysis method was carried out. Then a logistic regression analysis was performed to assess the simultaneous effect of socioeconomic and demographic factors. Findings of the study reveal that respondent education level, partner\u27s education level, religion, reading newspaper, and type of place of residence had significant contributions for early age at first birth among the female in Bangladesh. Based on the findings, there seems a decreasing trend of having early childbearing in Bangladeshi women over the years, but still, no optimal fertility rate has been achieved. For complex socio-cultural settings in Bangladesh, it is difficult to reduce the fertility rate. Hence, to reduce the prevalence of the age at early childbearing in Bangladesh, the Government and non-government organizations should take proper initiatives considering our study findings
Progressive managerial bonuses in a spatial Bertrand duopoly
The relationship of managerial bonuses and profit maximization is interesting both from an economic and a managerial viewpoint. Our contribution to this literature is showing that progressive managerial bonuses can increase profits in a spatial Bertrand competition, and furthermore they can help collusion
The mutualistic fungus Piriformospora indica protects barley roots from a loss of antioxidant capacity caused by the necrotrophic pathogen Fusarium culmorum
Fusarium culmorum causes root rot in barley (Hordeum vulgare), resulting in severely reduced plant growth and yield. Pretreatment of roots with chlamydospores of the mutualistic root-colonizing basidiomycete Piriformospora indica (Agaricomycotina) prevented necrotization of root tissues and plant growth retardation commonly associated with Fusarium root rot. Quantification of Fusarium infections with a real-time PCR assay revealed a correlation between root rot symptoms and the relative amount of fungal DNA. Fusarium-infected roots showed reduced levels of ascorbate and glutathione (GSH), along with reduced activities of antioxidant enzymes such as superoxide dismutase (SOD), ascorbate peroxidase (APX), glutathione reductase (GR), dehydroascorbate reductase (DHAR), and monodehydroascorbate reductase (MDHAR). Consistent with this, Fusarium-infected roots showed elevated levels of lipid hydroperoxides and decreased ratios of reduced to oxidized forms of ascorbate and glutathione. In clear contrast, roots treated with P. indica prior to inoculation with F. culmorum showed levels of ascorbate and GSH that were similar to controls. Likewise, lipid peroxidation and the overall reduction in antioxidant enzyme activities were largely attenuated by P. indica in roots challenged by F. culmorum. These results suggest that P. indica protects roots from necrotrophic pathogens at least partly, through activating the plant’s antioxidant capacity
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