Dielectric function and its predicted effect on localized plasmon resonances of equiatomic Au-Cu

© 2015 IOP Publishing Ltd. Equiatomic (Au,Cu) solid solution orders below 658 K to form a tetragonal AuCu (I) phase with significant changes in physical properties and the crystal structure. The effect of ordering on the dielectric function of the material is controversial however, with inconsistent results reported in the literature. Since the nature of any localized surface plasmon resonance (LSPR) in the nanostructures is very sensitive to the dielectric function, this uncertainty hinders the use of AuCu in plasmonic devices or structures. Therefore, we re-examine the question using a combination of measurements and computations. We find that no significant change in the dielectric function occurs when this material becomes ordered, at least over the range of photon energies relevant to LSPRs. The likely properties of LSPRs in plasmonic devices made of AuCu are analyzed. Use of the alloy offers some advantages over pure Cu, however pure Au would still be the superior option in most situations

Overview of SRF Deflecting and Crabbing Cavities

Developments over the past few years on novel superconducting deflecting and crabbing cavities have introduced advanced rf geometries with improved performance, in comparison to the typical squashed elliptical cavities operating in TM110 type mode. These new structures are compact geometries operating in either TEM type or TE11-like mode. One of the key applications of such cavities is the use of crabbing systems for circular colliders in increasing the luminosity. Crabbing systems are an essential component in future colliders with intense beams and proposed electron-ion colliders. High luminosity upgrade of LHC is planned to implement crabbing systems at two interaction points. Recently, a two-cavity cryomodule with double quarter wave crabbing cavity was installed in SPS at CERN and successfully tested with the proton beam. We present the details of different superconducting deflecting and crabbing cavities and their applications, as well as the recent results of the crabbing systems test at SPS

Thermal stability of nanoporous raney gold catalyst

© 2015 by the authors; licensee MDPI, Basel, Switzerland. Nanoporous “Raney gold” sponge was prepared by de-alloying an Au-Al precursor alloy. Catalytic tests using a micro-reactor confirmed that Raney gold can serve as an active heterogeneous catalyst for CO oxidation, reduction of NO to N2, and oxidation of NO to NO2. In general, the specific surface area of a heterogeneous catalyst has an influence on its catalytic efficacy. Unfortunately, gold sponges coarsen readily, leading to sintering of their structure and reduction in surface area. This potentially places constraints on their upper operating temperature in catalytic reactors. Here we analyzed the behavior of Raney gold when the temperature was raised. We examined the kinetics and mechanism of coarsening of the sponge using a combination of in situoptical measurements and Metropolis Monte Carlo modeling with a Lennard-Jones interatomic potential. Modeling showed that the sponges started with an isotropic “foamy” morphology with negative average “mean curvature” but that subsequent thermally activated coarsening will drive the morphology through a bi-continuous fibrous state and on, eventually, to a sponge consisting of sintered blobs of predominantly positive “mean curvature”

Copper Containing Silicates as Catalysts for Liquid Phase Cyclohexane Oxidation

Copper containing silicates have been prepared by an acid-catalyzed sol-gel process. The materials were characterized by X-ray diffraction and fluorescence, EPR spectroscopy, elemental analysis, N2-physisorption, thermogravimetry, differential scanning calorimetry, temperature-programmed reduction, FTIR and UV/VIS spectroscopy. The silicates were shown to be efficient catalysts for the oxidation of cyclohexane with tert-butyl hydroperoxide as oxidant. Cyclohexanol and cyclohexanone were obtained as the main products. The metal was shown to be weakly bound to the silicate matrix and metal leaching was observed. Leaching was quantified by X-ray fluorescence and leaching tests showed that the catalytic activity is due to supported copper species. Leached copper showed no activity in the homogeneous phase.Silicatos contendo cobre foram preparados pelo processo sol-gel catalisado por ácido. Os materiais foram caracterizados por difração e fluorescência de raios X, espectroscopia EPR, análise elementar, fisissorção de N2, termogravimetria, calorimetria diferencial de varredura, redução à temperatura programada, espectroscopia FTIR e UV/VIS. Os silicatos mostram-se catalisadores eficientes para a oxidação do cicloexano com hidroperóxido de tert-butila como oxidante e obtiveram-se cicloexanona e cicloexanol como produtos principais da reação. O metal mostrou-se fracamente ligado à matriz de sílica e foi observada lixiviação do metal para a fase líquida. A lixiviação foi quantificada por fluorescência de raios X. Testes de lixiviação mostraram que a atividade catalítica é devida às espécies de cobre suportadas. O cobre lixiviado não mostrou nenhuma atividade catalítica em fase homogênea.170176Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Measurement of Surface Resistance Properties With Coaxial Resonators - Review

Achieving ever decreasing surface resistance at higher field in superconducting RF accelerating structures is one of most outstanding developments in modern accelerators. The BCS theory has been used widely to estimate the surface resistance and to direct the technology. However, recent research results show that the behavior of the surface resistance further deviates from the BCS theory. So far the study on surface resistance was performed usually with cavities of single frequency which limited the study of frequency dependent surface resistance. The Center for Accelerator Science at Old Dominion University has designed and built several half wave coaxial cavities to study the frequency, temperature, and RF field dependence of surface resistance. TRIUMF in Canada also joined this line of research using such multi frequency quarter wave and half wave coaxial cavities. This type of multi mode cavity will allow us to systematically study the parameters affecting surface resistance on the same cavity surface. In this paper, we review the results ODU and TRIUMF collected so far and proper analysis methods

Rascunhos e esboços: indícios do processo criativo na literatura e no design gráfico.

Este artigo procura identificar pontos de encontro entre os métodos e processos criativos nos campos da literatura e do design gráfico. Tal como ocorre na análise dos rascunhos literários (na área de estudo da Crítica Genética), nota-se também possível compreender melhor o processo criativo em design a partir da análise de esboços e versões desenvolvidos pelo designer, que vão sendo refinados até que se chegue ao resultado final – resquícios que podem ser de grande valia para o entendimento do processo, procurando tornar mais límpida a etapa da criação artística. As percepções descritas neste trabalho levam a crer que os estudos sobre processos criativos, nas áreas mais diversas, parecem poder ter mais pontos de contato do que inicialmente considerado, visto que os procedimentos teórico-metodológicos são similares, com grande potencial para serem estudados em conjunto, de modo que uma área contribua com a outra

A fuzzy expert system in buildings serviceability

The preservation of the built heritage plays an essential role in the revitalization of current societies, being crucial to their social and economic development. The buildings’ service life should be used as a decision criterion in the definition of rehabilitation and maintenance strategies. This study proposes a model to analyse the buildings’ serviceability, which is a complex issue, since the functional service life of buildings and components are usually related with subjective concepts and requirements. For this, an expert system called as Fuzzy Buildings Service Life - FBSL is proposed, it is a computational tool that applies a fuzzy logic model for estimating the functional service life of the buildings under analysis. The fuzzy inference system (FIS) is based on professional expert knowledge and it is implemented in the open access software Xfuzzy 3.0. This model is based on 17 input factors, five related with vulnerability and 12 related with external risks and the model’s output is a functionality index. This research represents a new breakthrough in the field of thefunctionalservice life prediction, where architectural construction is considered as a single element. The expert system has been normalized through the international standard ISO 31000:2011 (risk management, assessment and analysis). This model was initiallyapplied to100heritage buildings (churches built between the 13rdand the 18thcenturies) located in Spain, being posteriorly applied to other buildings located in other European regions. In this approach, an example with five monuments is shown. Also the model was validated through the comparison to another service life prediction model, widely used in the literature, ensuring the model’s accuracy for ranking buildings’ serviceability. This model is able to accurately prioritize proactive rehabilitation actions, which is an essential dimension in order to implement preventive maintenance programs of buildings and architectural heritage set

Limits on different Majoron decay modes of 100^{100}Mo and 82^{82}Se for neutrinoless double beta decays in the NEMO-3 experiment

The NEMO-3 tracking detector is located in the Fr\'ejus Underground Laboratory. It was designed to study double beta decay in a number of different isotopes. Presented here are the experimental half-life limits on the double beta decay process for the isotopes $^{100}$Mo and $^{82}$Se for different Majoron emission modes and limits on the effective neutrino-Majoron coupling constants. In particular, new limits on "ordinary" Majoron (spectral index 1) decay of $^{100}$Mo ($T_{1/2} > 2.7\cdot10^{22}$ y) and $^{82}$Se ($T_{1/2} > 1.5\cdot10^{22}$ y) have been obtained. Corresponding bounds on the Majoron-neutrino coupling constant are $< (0.4-1.9) \cdot 10^{-4}$ and $< (0.66-1.7) \cdot 10^{-4}$.Comment: 23 pages includind 4 figures, to be published in Nuclear Physics

Avaliação do método prático para dimensionamento de estoques (MPDE) no contexto de melhorias na gestão de estoques em uma Empresa de médio porte do setor / Method practical for stocks sizing (MPSS) of assessment in the context of improvements in management stocks on a company average size of timber industry

A proposta deste estudo é verificar a desempenho da metodologia prática de dimensionamento de estoques (MPDE). A MPDE foi desenvolvida visando definir as decisões necessárias para obter o desempenho logístico considerando o cenário em que a empresa alvo está inserida. Tudo isso para oferecer melhorias na decisão de quanto estoque manter na empresa além de ações para diminuir o risco de ruptura de estoque. Este trabalho foi aplicado em uma empresa de médio porte do setor madeireiro no estado do Pará. O estudo de caso fará um diagnóstico da situação anterior à implantação do MPDE e posteriormente comparar e identificar as melhorias e também as ineficiências do método na empresa em questão. Para a realização do estudo optou-se por uma pesquisa tanto qualitativa quanto quantitativa, através de entrevistas com gestores responsáveis pela empresa e também indicadores quantitativos de estoque. Como finalidade, pretende-se diagnosticar as reais mudanças que ocorreram na empresa estudada e como essas mudanças contribuíram ou não para a melhoria da eficácia dos estoques do estudo de caso. 

Mating system of the Eurasian badger, Meles meles, in a high density population

Badgers are facultatively social, forming large groups at high density. Group-living appears to have high reproductive costs for females, and may lead to increased levels of inbreeding. The extent of female competition for reproduction has been estimated from field data, but knowledge of male reproductive success and the extent of extra-group paternity remains limited. Combining field data with genetic data (16 microsatellite loci), we studied the mating system of 10 badger social groups across 14 years in a high-density population. From 923 badgers, including 425 cubs, we were able to assign maternity to 307 cubs, with both parents assigned to 199 cubs (47%) with 80% confidence, and 14% with 95% confidence. Age had a significant effect on the probability of reproduction, seemingly as a result of a deficit of individuals aged two years and greater than eight years attaining parentage. We estimate that approximately 30% of the female population successfully reproduced in any given year, with a similar proportion of the male population gaining paternity across the same area. While it was known there was a cost to female reproduction in high density populations, it appears that males suffer similar, but not greater, costs. Roughly half of assigned paternity was attributed to extra-group males, the majority of which were from neighbouring social groups. Few successful matings occurred between individuals born in the same social group (22%). The high rate of extra-group mating, previously unquantified, may help reduce inbreeding, potentially making philopatry a less costly strategy