Kondo effect under the influence of spin–orbit coupling in a quantum wire

The analysis of the impact of spin–orbit coupling (SOC) on the Kondo state has generated considerable controversy, mainly regarding the dependence of the Kondo temperature T K on SOC strength. Here, we study the one-dimensional (1D) single impurity Anderson model (SIAM) subjected to Rashba (α) and Dresselhaus (β) SOC. It is shown that, due to time-reversal symmetry, the hybridization function between impurity and quantum wire is diagonal and spin independent (as it is the case for the zero-SOC SIAM), thus the finite-SOC SIAM has a Kondo ground state similar to that for the zero-SOC SIAM. This similarity allows the use of the Haldane expression for T K, with parameters renormalized by SOC, which are calculated through a physically motivated change of basis. Analytic results for the parameters of the SOC-renormalized Haldane expression are obtained, facilitating the analysis of the SOC effect over T K. It is found that SOC acting in the quantum wire exponentially decreases T K while SOC at the impurity exponentially increases it. These analytical results are fully supported by calculations using the numerical renormalization group (NRG), applied to the wide-band regime, and the projector operator approach, applied to the infinite-U regime. Literature results, using quantum Monte Carlo, for a system with Fermi energy near the bottom of the band, are qualitatively reproduced, using NRG. In addition, it is shown that the 1D SOC SIAM for arbitrary α and β displays a persistent spin helix SU(2) symmetry similar to the one for a 2D Fermi sea with the restriction α = β.VL acknowledges a PhD scholarship from the Brazilian Agency Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), process 160071/2015-1, and financial support from the Generalitat Valenciana through Grant reference Prometeo 2017/139. MM acknowledges a PhD scholarship from the Brazilian Agency Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES). GBM acknowledges financial support from CNPq, processes 424711/2018-4 and 305150/2017-0. EVA acknowledges financial support from CNPq, process 306000/2017-2

Caracterización química y espectroscópica de material particulado en aire extramuros en la ciudad de La Plata y alrededores

Este trabajo se centra en la caracterización química y espectroscópica de material particulado (MP10 y MP2.5) en la ciudad de La Plata y alrededores, que cuenta con alto tránsito vehicular y un polo petroquímico cercano, diferenciando tres zonas: residencial, urbano e industrial. Se analizó su contenido en metales pesados (Cd, Cr, Cu, Mn, Ni y Pb) y se realizó un análisis morfológico del MP mediante microscopía electrónica de barrido (SEM-EDS). Los niveles de MP evidencian mayores valores tanto para MP2.5 como para MP10 en la zona industrial, seguida por la zona urbana y por último por la zona residencial. Respecto a los metales se confirma la presencia de los metales Cr, Cu, Mn y Pb en ambas fracciones de MP y para las distintas zonas de estudio, con valores de concentración desde 0.0003 μg/m3 hasta 0.0491 μg/m3. Mediante la técnica SEM-EDS los resultados obtenidos muestran partículas mayoritariamente ricas en elementos como Si, C y O, y en menor medida en Al, Ca, Na, N y con presencia de partículas de morfología relacionadas al tráfico vehicular

Implementation of DMAs in Intermittent Water Supply Networks Based on Equity Criteria

[EN] Intermittent supply is a common way of delivering water in many developing countries. Limitations on water and economic resources, in addition to poor management and population growth, limit the possibilities of delivering water 24 h a day. Intermittent water supply networks are usually designed and managed in an empirical manner, or using tools and criteria devised for continuous supply systems, and this approach can produce supply inequity. In this paper, an approach based on the hydraulic capacity concept, which uses soft computing tools of graph theory and cluster analysis, is developed to define sectors, also called district metered areas (DMAs), to produce an equitable water supply. Moreover, this approach helps determine the supply time for each sector, which depends on each sector¿s hydraulic characteristics. This process also includes the opinions of water company experts, the individuals who are best acquainted with the intricacies of the network.Ilaya-Ayza, AE.; Martins-Alves, C.; Campbell-Gonzalez, E.; Izquierdo Sebastián, J. (2017). Implementation of DMAs in Intermittent Water Supply Networks Based on Equity Criteria. Water. 9(11):1-20. doi:10.3390/w9110851S12091

Control and operation of a three-phase local energy router for prosumers in a smart community

UID/EEA/00066/2019From the electrical energy point of view, the smart community (SC) concept is meant to be as a sustainable and environmentally friendly alternative to the classical configuration. The SC includes small-scale renewable energy sources (RES) and small-scale energy storage system (ESS). The SC energy management system acts as an aggregator, aiming to assure benefits for community stakeholders. These trends led to the energy routers (ERs) concept. This study proposes and describes the control strategies for these ERs to contribute to the SC goals. The approach of these strategies increases the RES adjustability, contributing to maintain the ESS state of health. The ER is able to operate simultaneously with active and reactive power control, besides compensating SC grid voltage imbalances, and providing ancillary services to the SC. The proposed control strategies are validated by simulations and experiments.publishersversionpublishe

O ensino da disciplina de contabilidade de gestão em Portugal

O objectivo do presente estudo centra-se no tipo de temáticas que actualmente integram os conteúdos programáticos ao nível dos bacharelatos e licenciaturas em que estas disciplinas são leccionadas. Os resultados do inquérito realizado aos responsáveis/regentes da disciplina Contabilidade Analítica, de Custos e/ou de Gestão evidenciam, ao nível dos bacharelatos e licenciaturas, um ensino da disciplina cuja ênfase ainda se centra nas temáticas tradicionais, com forte conotação em termos de aplicabilidade prática ao sector da transformação. É ao nível dos cursos de pós-graduação e de mestrado que se observa a inclusão de temáticas mais avançadas, indo de encontro ao ensino da verdadeira Contabilidade de Gestão.The purpose of this study is to focus on the type of themes that are included in curriculum programmes of bachelor’s and licentiate’s degrees where these disciplines are taught. The results of the questionnaire carried out to professors teaching the discipline: Analytical Accounting, Cost Accounting and/or Management Accounting, show us that according to bachelor’s and licentiate’s degrees, teaching still emphasizes traditional topics with strong connotation in terms of pratices in the manufacturing sector. More advanced issues are included in post-graduation and master’s degrees leading to knowledge and teaching of real Management Accounting

A model for predicting the Ms temperatures of steels.

Using neural networks in a Bayesian framework, a model has been derived for the Ms temperature of steels over a wide range of compositions. By its design and by use of a more extensive database, this model improves over existing ones, by its accuracy and its ability to avoid wild predictions.NPL for provision of MTDATA and Neuromat for provision of the Model Manager.Peer reviewe

Drivers and trends in the size and severity of forest fires endangering WUI areas: a regional case study

[EN] This study explored, for the first time, the drivers shaping large fire size and high severity of forest fires classified as level-2 in Spain, which pose a great danger to the wildland–urban interface. Specifically, we examined how bottom-up (fuel type and topography) and top-down (fire weather) controls shaped level-2 fire behavior through a Random Forest classifier at the regional scale in Galicia (NW Spain). We selected for this purpose 93 level-2 forest fires. The accuracy of the RF fire size and severity classifications was remarkably high (>80%). Fire weather overwhelmed bottom-up controls in controlling the fire size of level-2 forest fires. The likelihood of large level-2 forest fires increased sharply with the fire weather index, but plateaued at values above 40. Fire size strongly responded to minimum relative humidity at values below 30%. The most important variables explaining fire severity in level-2 forest fires were the same as in the fire size, as well as the pre-fire shrubland fraction. The high-fire-severity likelihood of level-2 forest fires increased exponentially for shrubland fractions in the landscape above 50%. Our results suggest that level-2 forest fires will pose an increasing danger to people and their property under predicted scenarios of extreme weather conditionsSIProject 4Map4Health is selected in the call ERA-Net CHIST-ERA (2019) and funded by the State Research Agency of Spain (reference PCI2020-120705-2/AEI/10.13039/501100011033). PMF and JMFG were supported by National Funds from FCT—Portuguese Foundation for Science and Technology, under the project UIDB/04033/2020. JMFG was supported by a postdoctoral fellowship granted by the Ramón Areces Foundatio

Implicações do clima organizacional na qualidade dos serviços públicos autárquicos segundo o modelo da estrutura comum de avaliação: estudo do caso de uma câmara municipal portuguesa

O presente trabalho pretende, partindo-se de algumas das componentes do Modelo da Estrutura Comum de Avaliação (Common Assessement Framework), analisar a influência que a liderança - como meio do referido modelo - terá em alguns dos factores que constituem o clima organizacional e daí extrair qual o impacto destes na qualidade dos serviços públicos autárquicos, através dos resultados relativos às pessoas - resultado do mesmo modelo. Para efeitos do presente trabalho serão considerados dois dos sistemas de liderança de Likert (autocrático-coercivo e participativo), bem como alguns dos factores do clima organizacional (motivação, satisfação, empowerment, conflito e stress).The present work pretends, by starting with some of the components of the Common Assessement Framework Model, to analyse the influence that leadership – as agent of the refered model – have in some of the organizational climate factors and then know what is the impact of such factors in the quality of the public services of the local authorities (city councils) throw the results of the persons - result of the same model. For that we used two of the leardership systems of Likert [authoritarian (autocratic) and participative (democratic)] and some of the organizational climate factors (motivation, satisfaction, empowerment, conflict and stress)

Acclimation and cold storage on postharvest quality of bananas 'nanicão'

This work aimed to evaluate, through physical and chemical parameters, the postharvest quality of banana 'Nanicão' totally green and acclimatized after 17 days of storage, and totally green and submitted to two storage conditions (room temperature and cooling). Fruits were harvested at totally green color stage and the experiment was conducted in a completely randomized design with four treatments: (stored at 13 °C; stored at 25 °C; stored for 17 days at 13 °C, ripened and stored at 13 °C; stored for 17 days at 13 °C, ripened and stored at 25 °C). The performed evaluations were: loss of fresh mass, titratable acidity, pH, soluble solids and total and reducing sugars. Totally green non-acclimatized Bananas 'Nanicão' stored for 38 days at 13 °C and 28 days at 25 °C did not complete the ripening process. Also they exhibited a small increase of soluble solids, total and reducing sugars, and a high percentage of loss of fresh mass. The totally green fruit stored for 17 days at 13 °C and subsequently brought into the process of acclimatization ripened completely. However, these fruits exhibited lower sugar content and high mass loss, regardless the storage temperature. The period of 17 days is not recommended for storage of bananas 'Nanicão' totally green for further acclimatization. The cooling temperature (13 °C) was effective in delaying fruit ripening.Este trabalho teve como objetivo avaliar, por meio de parâmetros físicos e químicos, a qualidade pós-colheita de banana 'Nanicão' totalmente verde e climatizada após 17 dias de armazenamento ou totalmente verde e submetida a duas condições de armazenagem (temperatura ambiente e refrigerada). Os frutos foram colhidos em estágio de cor totalmente verde e o experimento foi instalado em delineamento inteiramente casualizado com quatro tratamentos (frutos totalmente verdes armazenados a 13 °C; frutos totalmente verdes e armazenados 25 °C; frutos armazenados totalmente verdes por 17 dias a 13 °C, amadurecidos e armazenados a 13°C; frutos armazenados totalmente verdes por 17 dias a 13 °C, amadurecidos e armazenados a 25 °C). As análises realizadas foram: perda de massa fresca; acidez titulável; pH; sólidos solúveis e teores de açúcares totais e redutores. As bananas 'Nanicão' de coloração totalmente verdes não climatizadas e armazenadas por 38 dias a 13 °C ou 28 dias a 25 °C não completaram o processo de amadurecimento. Houve reduzido aumento de sólidos solúveis, açúcares totais e redutores, além de elevada perda de massa. Os frutos armazenados totalmente verdes por 17 dias a 13 °C e, posteriormente, levados para o processo de climatização, amadureceram completamente, porém ficaram com menor teor de açúcar e elevada perda de massa, independentemente da temperatura de armazenamento. O período de 17 dias não é recomendado para a estocagem de bananas 'Nanicão' totalmente verdes para posterior climatização. A refrigeração a 13 °C foi eficiente para retardar o amadurecimento dos frutos.735744Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES