Shear viscosity of a model for confined granular media

The shear viscosity in the dilute regime of a model for confined granular matter is studied by simulations and kinetic theory. The model consists on projecting into two dimensions the motion of vibrofluidized granular matter in shallow boxes by modifying the collision rule: besides the restitution coefficient that accounts for the energy dissipation, there is a separation velocity that is added in each collision in the normal direction. The two mechanisms balance on average, producing stationary homogeneous states. Molecular dynamics simulations show that in the steady state the distribution function departs from a Maxwellian, with cumulants that remain small in the whole range of inelasticities. The shear viscosity normalized with stationary temperature presents a clear dependence with the inelasticity, taking smaller values compared to the elastic case. A Boltzmann-like equation is built and analyzed using linear response theory. It is found that the predictions show an excellent agreement with the simulations when the correct stationary distribution is used but a Maxwellian approximation fails in predicting the inelasticity dependence of the viscosity. These results confirm that transport coefficients depend strongly on the mechanisms that drive them to stationary states

Carbon (CI) and energy intensity (EI) dataset for retail stores

Transparency data associated with this article can be found in the online version at: https://doi.org/10.1016/j.dib.2018.10.080This data article presents data collected from the 250 highest revenue retailers around the world, assessed according to publicly available data from the fiscal year 2016, in order to determine retailer?s overall carbon intensity (CI) and energy intensity (EI). Data collection included additional variables such as retailers? revenue rank, operational typology, number of stores, store sales area and number of workers. CI and EI benchmarks were calculated for food and non-food retailers, applying the statistic function first quartile (Q1) for the best practice, second (Q2) and third (Q3) quartiles for conventional practice and fourth quartile (Q4) for worst practice. Correlations were tested between the variables "EI", "CI" and "retailer revenue", applying the statistic function CORREL. Finally, a cluster analysis was performed for food and non-food retailers, to identify possible segmentation patterns between the variables ?EI?, ?CI? and ?retailer revenue?. The information provided in this data article is useful for furthering research developments on the influence of isolated variables on retail EI and CI and in assisting retailers, architects, engineers, and policy makers in establishing optimal energy performance goals for the design and operation of retail stores. For further data interpretation and discussion, see the article ?Combined carbon and energy intensity benchmarks for sustainable retail stores?[1], of the same authors.This work was supported by FCT - Fundação para a Ciência e Tecnologia [grant number PD/BD/127852/2016] under the Doctoral Program EcoCoRe - Eco-Construction and Rehabilitation.info:eu-repo/semantics/publishedVersio

Combined carbon and energy intensity benchmarks for sustainable retail stores

Retail stores are amongst the building typologies with the highest carbon (CI) and energy intensities (EI). However, previous studies have only explored the EI of food and non-food retailers. This study is the first of its kind to examine the link between CI and EI. Establishing the nature of this link will allow a deeper understanding of how to decarbonize the retail sector. Here, we hypothesised whether in retail low EI correlated with low CI and how corporate revenue affected these variables. ?Best practice? and ?conventional practice? benchmarks were then developed to assess retail buildings' sustainability. These represent missing and highly desirable tools in retail sustainable management. Average EI and CI of food retailers were twice that of non-food retailers (EI-548 vs 238?kWh/m2/y; CI266 vs 132?kg CO?eq/m2/y). The correlation found between EI and CI indicates that low energy consumption leads to low greenhouse gas (GHG) emissions. CI variability resulted mostly of energy-efficiency strategies, of the energy production process and of GHG emissions from refrigeration systems. EI variability resulted mostly from store typology, volume and usage. The proposed benchmarks help to set energy and carbon reference performance levels in retail buildings and to stimulate best sustainable practice amongst retailers.This work was supported by FCT - Fundação para a Ciência e Tecnologia [grant number PD/BD/127852/2016] under the Doctoral Program EcoCoRe - Eco-Construction and Rehabilitation. Support from CERIS and Instituto Superior Técnico is also acknowledged.info:eu-repo/semantics/publishedVersio

Economic valuation of life cycle environmental impacts of construction products - A critical analysis

The aim of this paper is to identify existing methods for economic valuation or monetisation of life cycle environmental impacts and to assess its applicability in the broad European context. Although environmental awareness is more and more important in several industrial sectors, including the construction sector, easy to understand data are still missing for professionals to assess and manage impacts related to the whole life cycle of a building. Life Cycle Assessment (LCA) is one of the most commonly accepted methodologies to calculate potential life cycle environmental impacts of a product or service. However, the results of such method, even when published in an Environmental Product Declaration, meant for business to business communication, are not always comparable or easily understandable by non-practitioners. Economic valuation or monetisation of LCA results is a weighting step that can make it easier for non-practitioners to use LCA results to support decision-making. From the several monetisation methods analysed, it is discussed the one that is most suitable for use when LCA results already exist. It is concluded that further work is needed to improve such weighting methods or develop a common one that can be representative at a broader geographical level (for instance, Europe-wide).This work was supported by FCT - Fundação para a Ciência e Tecnologia [grant number PD/BD/127850/2016] under the Doctoral Program EcoCoRe - Eco-Construction and Rehabilitation. Support from CERIS and Instituto Superior Técnico is also acknowledged

Uma auditoria confiável adiciona valor?

This article studies the impact of the year 2002 audit failures on the auditors’ clients’ stock prices. Specifically, we examine the Big 5’s clients stock market impact surrounding various dates on which one of the Big 5’s audit procedures and independence were under scrutiny: Omnicom, Merck, WorldCom, Qwest, Xerox, Bristol Meyers, Duke Energy, El Paso and AOL events. In general, on failures involving Arthur Andersen, Andersen’s former client’s and clients of the auditor in place experienced statistically negative market reactions. On events involving other Big 4, clients didn’t experience statistically negative market reactions. The SEC order to CEO’s certification causes volatility but not statistically negative market reactions.Este artigo estuda o impacto das falhas de auditorias sobre os preços das ações dos clientes dos auditores. Examinamos especificamente o impacto no valor de mercado dos clientes das 5 Grandes, cobrindo eventos de 2002 nos quais os procedimentos de auditoria de uma delas e sua independência encontravam-se sob escrutínio: Omnicon, Merck, WorldCom, Qwest, Xerox, Bristol Meyers, Duke Energy, El Paso e AOL. Em geral, nas falhas envolvendo a Arthur Andersen, seus clientes e os clientes da auditoria responsável à época do reconhecimento da falha experimentaram reações de mercado estatisticamente negativas. Em eventos envolvendo as outras 4 Grandes, os clientes não experimentaram reações estatisticamente negativas. A ordem da SEC para certificação dos Diretores-Presidentes (CEO) causa volatilidade mas não reações estatisticamente negativas

O Prêmio pela Maturidade na Estrutura a Termo das Taxas de Juros Brasileiras

This paper tests the Rational Expectations Hypothesis in Brazil from July 1996 to December 2001 for maturities ranging from 1 day to 1 year. It shows that (i) the estimated coefficients in the regressions of the short-run changes of the long rate on the yield spread and in the regressions of the long-run changes of the short rate on the yield spread are imprecise and unable to reject the REH. On the other hand, (ii) yield spreads highly correlated with the rational expectations forecasts of the perfect foresight spreads, but significantly more volatile than these, suggest the rejection of the REH. The alternative hypothesis of overreaction of the yield spread to the present short rate (or under-reaction of the long rate to the present short rate) seems to be a reasonable explanation to the findings that (iii) the estimated coefficients are significantly lower than unit and (iv) the residual are orthogonal to the agents information set in the regressions of the rational expectations forecasts on the yield spreads.