466 research outputs found
Disorder Induced Stripes in d-Wave Superconductors
Stripe phases are observed experimentally in several copper-based high-Tc
superconductors near 1/8 hole doping. However, the specific characteristics may
vary depending on the degree of dopant disorder and the presence or absence of
a low- temperature tetragonal phase. On the basis of a Hartree-Fock decoupling
scheme for the t-J model we discuss the diverse behavior of stripe phases. In
particular the effect of inhomogeneities is investigated in two distinctly
different parameter regimes which are characterized by the strength of the
interaction. We observe that small concen- trations of impurities or vortices
pin the unidirectional density waves, and dopant disorder is capable to
stabilize a stripe phase in parameter regimes where homogeneous phases are
typically favored in clean systems. The momentum-space results exhibit
universal features for all coexisting density-wave solutions, nearly unchanged
even in strongly disordered systems. These coexisting solutions feature
generically a full energy gap and a particle-hole asymmetry in the density of
states.Comment: 28 pages, 8 figure
INTERNATIONAL LAW AND âTHIRD WORLDâ APPROACHES: CONTRIBUTIONS OF THE CRITICAL LEGAL THEORY
The purpose of this article is to stimulate a critical reflection on central concepts of international law by throwing some light on colonizing historical continuities that remain subjacent to its construction. Relying on critical theory, it proposes a questioning of non-declared premises that sustain the international legal system, which is here understood through the point of view of the political movement of the âThird Worldâ. The critical theory generally sees international law as an expression of the contradictions of international politics and, in its prognostics, founds itself on a material subversion of the system: a movement that comes from the very contradictions of the political reality. This research delineates some of the contributions of this system of thought to the construction of international law, especially with regard to the inclusion of historically excluded subjects as participants in international decision processes, with a view to produce in the international community a new framework of relations and interactions among all the subjects that are part of it.O presente artigo tenciona estimular uma reflexĂŁo crĂtica sobre conceitos centrais do direito internacional, ao jogar luz sobre certas continuidades histĂłricas colonializantes que permanecem subjacentes na construção da disciplina. Valendo-se da teoria crĂtica, propĂ”e um questionamento de premissas nĂŁo declaradas que sustentam o sistema jurĂdico internacional, aqui compreendido a partir do ponto de vista do movimento polĂtico do âTerceiro Mundoâ. A teoria crĂtica geralmente percebe o direito internacional como expressĂŁo das contradiçÔes da polĂtica internacional e, em seu prognĂłstico, funda-se na subversĂŁo material de um sistema: um movimento que se inicie a partir das contradiçÔes da realidade polĂtica. Essa pesquisa delineia algumas das contribuiçÔes desse sistema de pensamento para a construção do direito internacional, especialmente no que diz respeito Ă inclusĂŁo de sujeitos historicamente excluĂdos na participação nos processos decisĂłrios internacionais, com vistas ao desenvolvimento de um outro framework de relaçÔes e interaçÔes entre todos os sujeitos que fazem parte da comunidade internacional
Techno-Economic Assessment & Life-Cycle Assessment Guidelines for CO2 Utilization
NOTE: Updated version 1.1 available at http://hdl.handle.net/2027.42/162573
Climate change is one of the largest challenges of our time. One of the major causes of anthropogenic climate change, carbon dioxide, also leads to ocean acidification. Left unaddressed, these two challenges will alter ecosystems and fundamentally change life, as we know it. Under the auspices of the UN Framework Convention on Climate Change and through the Paris Agreement, there is a commitment to keep global temperature increase to well below two degrees Celsius. This will require a variety of strategies including increased renewable power generation and broad scale electrification, increased energy efficiency, and carbon-negative technologies.
We believe that Life Cycle Assessment (LCA) is necessary to prove that a technology could contribute to the mitigation of environmental impacts and that Techno-Economic Assessment (TEA) will show how the technology could be competitively delivered in the market. Together the guidelines for LCA and TEA that are presented in this document are a valuable toolkit for promoting carbon capture and utilization (CCU) technology development.Development of standardized CO2 Life Cycle and Techno-economic Assessment Guidelines was commissioned by CO2 Sciences, Inc., with the support of 3M, EIT Climate-KIC, CO2 Value Europe, Emissions Reduction Alberta, Grantham Foundation for the Protection of the Environment, R. K. Mellon Foundation, Cynthia and George Mitchell Foundation, National Institute of Clean and Low Carbon Energy, Praxair, Inc., XPRIZE and generous individuals who are committed to action to address climate change.https://deepblue.lib.umich.edu/bitstream/2027.42/145436/3/Global_CO2_Initiative_TEA_LCA_Guidelines-2018.pdf-
Methanol Worked Examples for the TEA and LCA Guidelines for CO2 Utilization
This document contains worked examples of how to apply the accompanying âGuideline for Techno-Economic Assessment of CO2 Utilizationâ and âGuideline for Life Cycle Assessment of CO2 Utilizationâ. The Guidelines can be downloaded via http://hdl.handle.net/2027.42/145436.
These worked examples are not intended to be a definitive TEA or LCA report on the process described, but are provided as supporting material to show how the TEA and LCA methodologies described in the guidelines can be specifically applied to tackle the issues surrounding CO2 utilization. This document describes techno-economic assessment and life cycle assessment for methanol production. As methanol production via hydrogenation and PEM electrolysis of water to produce hydrogen are both at high technology readiness levels (TRL7+); a CO2 capture technology currently at a lower TRL (membrane separation at TRL3 or 4) was selected to demonstrate the differences that can be observed in the interpretation phase when working on TEA and LCA studies of processes with lower TRLs. It is acknowledged that there are many unknown variables with membrane capture, and it is not within the remit of this work to draw conclusions on their application. However, it is known that organizations wish to conduct TEA and LCA studies across a range of TRLs and therefore we hope to demonstrate here how this could affect the results. This document is one of several application examples that accompany the parent document âTechno-Economic Assessment & Life-Cycle Assessment Guidelines for CO2 Utilizationâ.Development of standardized CO2 Life Cycle and Techno-economic Assessment Guidelines was commissioned by CO2 Sciences, Inc., with the support of 3M, EIT Climate-KIC, CO2 Value Europe, Emissions Reduction Alberta, Grantham Foundation for the Protection of the Environment, R. K. Mellon Foundation, Cynthia and George Mitchell Foundation, National Institute of Clean and Low Carbon Energy, Praxair, Inc., XPRIZE and generous individuals who are committed to action to address climate change.https://deepblue.lib.umich.edu/bitstream/2027.42/145723/5/Global CO2 Initiative Complete Methanol Study 2018.pd
Size and shape dependent photoluminescence and excited state decay rates of diamondoids
Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugĂ€nglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.We present photoluminescence spectra and excited state decay rates of a series of diamondoids, which represent molecular structural analogues to hydrogen-passivated bulk diamond. Specific isomers of the five smallest diamondoids (adamantaneâpentamantane) have been brought into the gas phase and irradiated with synchrotron radiation. All investigated compounds show intrinsic photoluminescence in the ultraviolet spectral region. The emission spectra exhibit pronounced vibrational fine structure which is analyzed using quantum chemical calculations. We show that the geometrical relaxation of the first excited state of adamantane, exhibiting Rydberg character, leads to the loss of Td symmetry. The luminescence of adamantane is attributed to a transition from the delocalized first excited state into different vibrational modes of the electronic ground state. Similar geometrical changes of the excited state structure have also been identified in the other investigated diamondoids. The excited state decay rates show a clear dependence on the size of the diamondoid, but are independent of the particle geometry, further indicating a loss of particle symmetry upon electronic excitation.DFG, FOR 1282, Controlling the electronic structure of semiconductor nanoparticles by doping and hybrid formatio
Downregulation of organic cation transporters OCT1 (SLC22A1) and OCT3 (SLC22A3) in human hepatocellular carcinoma and their prognostic significance
<p>Abstract</p> <p>Background</p> <p>Organic cation transporters (OCT) are responsible for the uptake and intracellular inactivation of a broad spectrum of endogenous substrates and detoxification of xenobiotics and chemotherapeutics. The transporters became pharmaceutically interesting, because OCTs are determinants of the cytotoxicity of platin derivates and the transport activity has been shown to correlate with the sensitivity of tumors towards tyrosine kinase inhibitors. No data exist about the relevance of OCTs in hepatocellular carcinoma (HCC).</p> <p>Methods</p> <p>OCT1 (<it>SLC22A1</it>) and OCT3 (<it>SLC22A3</it>) mRNA expression was measured in primary human HCC and corresponding non neoplastic tumor surrounding tissue (TST) by real time PCR (n = 53). Protein expression was determined by western blot analysis and immunofluorescence. Data were correlated with the clinicopathological parameters of HCCs.</p> <p>Results</p> <p>Real time PCR showed a downregulation of <it>SLC22A1 </it>and <it>SLC22A3 </it>in HCC compared to TST (p †0.001). A low <it>SLC22A1 </it>expression was associated with a worse patient survival (p < 0.05). Downregulation was significantly associated with advanced HCC stages, indicated by a higher number of T3 tumors (p = 0.025) with a larger tumor diameter (p = 0.035), a worse differentiation (p = 0.001) and higher AFP-levels (p = 0.019). In accordance, <it>SLC22A1 </it>was less frequently downregulated in tumors with lower stages who underwent transarterial chemoembolization (p < 0.001) and liver transplantation (p = 0.001). Tumors with a low <it>SLC22A1 </it>expression (< median) showed a higher <it>SLC22A3 </it>expression compared to HCC with high <it>SLC22A1 </it>expression (p < 0.001). However, there was no significant difference in tumor characteristics according to the level of the <it>SLC22A3 </it>expression.</p> <p>In the western blot analysis we found a different protein expression pattern in tumor samples with a more diffuse staining in the immunofluorescence suggesting that especially OCT1 is not functional in advanced HCC.</p> <p>Conclusion</p> <p>The downregulation of OCT1 is associated with tumor progression and a worse patient survival.</p
Parameterized Games and Parameterized Automata
We introduce a way to parameterize automata and games on finite graphs with natural numbers. The parameters are accessed essentially by allowing counting down from the parameter value to 0 and branching depending on whether 0 has been reached. The main technical result is that in games, a player can win for some values of the parameters at all, if she can win for some values below an exponential bound. For many winning conditions, this implies decidability of any statements about a player being able to win with arbitrary quantification over the parameter values.While the result seems broadly applicable, a specific motivation comes from the study of chains of strategies in games. Chains of games were recently suggested as a means to define a rationality notion based on dominance that works well with quantitative games by Bassett, Jecker, P., Raskin and Van den Boogard. From the main result of this paper, we obtain generalizations of their decidability results with much simpler proofs.As both a core technical notion in the proof of the main result, and as a notion of potential independent interest, we look at boolean functions defined via graph game forms. Graph game forms have properties akin to monotone circuits, albeit are more concise. We raise some open questions regarding how concise they are exactly, which have a flavour similar to circuit complexity. Answers to these questions could improve the bounds in the main theorem
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