50,487 research outputs found
Brane webs in the presence of an -plane and 4d class S theories of type D
In this article we conjecture a relationship between 5d SCFT's, that can be
engineered by 5-brane webs in the presence of an -plane, and 4d class S
theories of type D. The specific relation is that compactification on a circle
of the former leads to the latter. We present evidence for this conjecture. One
piece of evidence, which is also an interesting application of this, is that it
suggests identifications between different class S theories. This can in turn
be tested by comparing their central charges.Comment: 30 pages, 18 figures; v2 minor revision, version published in JHE
Impact of alloy disorder on the band structure of compressively strained GaBiAs
The incorporation of bismuth (Bi) in GaAs results in a large reduction of the
band gap energy (E) accompanied with a large increase in the spin-orbit
splitting energy (), leading to the condition that
which is anticipated to reduce so-called CHSH Auger
recombination losses whereby the energy and momentum of a recombining
electron-hole pair is given to a second hole which is excited into the
spin-orbit band. We theoretically investigate the electronic structure of
experimentally grown GaBiAs samples on (100) GaAs substrates by
directly comparing our data with room temperature photo-modulated reflectance
(PR) measurements. Our atomistic theoretical calculations, in agreement with
the PR measurements, confirm that E is equal to for
9. We then theoretically probe the inhomogeneous
broadening of the interband transition energies as a function of the alloy
disorder. The broadening associated with spin-split-off transitions arises from
conventional alloy effects, while the behaviour of the heavy-hole transitions
can be well described using a valence band-anticrossing model. We show that for
the samples containing 8.5% and 10.4% Bi the difficulty in identifying a clear
light-hole-related transition energy from the measured PR data is due to the
significant broadening of the host matrix light-hole states as a result of the
presence of a large number of Bi resonant states in the same energy range and
disorder in the alloy. We further provide quantitative estimates of the impact
of supercell size and the assumed random distribution of Bi atoms on the
interband transition energies in GaBiAs. Our calculations support
a type-I band alignment at the GaBiAs/GaAs interface, consistent
with recent experimental findings
Grow rich and clean up later? International assistance and the provision of environmental quality in low- and middle-income countries
This paper deals with the question whether low- and middle-income countries that are politically better integrated into the international system are able to provide higher levels of environmental quality than could be expected only according to their national income levels. Using time-series cross-section regression analysis of 110 countries for the period 1950-1999 it can be shown that those countries that have signed and ratified more environmental treaties, have significantly lower SO2 emissions than countries that are less integrated into the international system. However, in contrast to theoretical predictions democratic low- and middle-income countries despite their stronger integration into the international system exhibit higher SO2 emissions indicating lower environmental quality than autocratic countries. --
Developing a LCA software in Hungary
In Hungary the first steps of LCA application can be observed. The objectives of the project are to establish a
fundamental online database of LCA compatibility with international software. This database can help designing
from the aspect of environment and can be used in education and research. We have classified the domestic
power plants on the basis of applied technology and energy sources. But data collection presents some difficulty.
Complex analysis of electric- and electronic equipment would be another important scope of the system. And we
would like to popularize the LCA application for the small and medium sized enterprises
How to be an Actualist and Blame People
The actualism/possibilism debate in ethics concerns the relationship between an agent’s free actions and her moral obligations. The actualist affirms, while the possibilist denies, that facts about what agents would freely do in certain circumstances partly determines that agent’s moral obligations. This paper assesses the plausibility of actualism and possibilism in light of desiderata about accounts of blameworthiness. This paper first argues that actualism cannot straightforwardly accommodate certain very plausible desiderata before offering a few independent solutions on behalf of the actualist. This paper then argues that, contrary to initial appearances, possibilism is subject to its own comparably troubling blameworthiness problem
A Comparative Life Cycle Assessment between a Metered Dose Inhaler and Electric Nebulizer
Life cycle assessment (LCA) evaluates the environmental impact of a product based on the materials and processes used to manufacture the item as well as the item’s use and disposal. The objective of this LCA was to evaluate and compare the environmental impact of a metered dose inhaler, specifically the Proventil® HFA inhaler (Merk & Co., Inc., Kenilworth, NJ, USA), and an electric nebulizer, specifically the DeVilbiss Pulmo-Aide® nebulizer (DeVilbiss, Port Washington, NY, USA). GaBi LCA software was used to model the global warming potential (GWP) of each product by using substantiated data and well-justified assumptions for the components, manufacturing, assembly, and use of both devices. The functional unit used to model each device was one dose of the active drug, albuterol sulfate. The inhaler’s GWP, 0.0972 kg CO2-eq, was greater than the nebulizer’s even when uncertain parameters were varied ±100x. During the use phase ofa the inhaler, which accounted for approximately 96% of the inhaler’s total GWP, HFA 134a is used as a propellant to deliver the drug. The total GWP for the electric nebulizer was 0.0294 kg CO2-eq assuming that the mouthpiece was cleaned in a dishwasher, while it was 0.0477 kg CO2-eq when the nebulizer mouthpiece was hand washed between uses. The GWP breakeven scenario between dishwashing and hand washing occurred when the mouthpiece accounted for 10% of the dishwasher load
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