(Meta-)stability and Core–Shell Dynamics of Gold Nanoclusters at Finite Temperature

Gold nanoclusters have been the focus of numerous computational studies, but an atomistic understanding of their structural and dynamical properties at finite temperature is far from satisfactory. To address this deficiency, we investigate gold nanoclusters via ab initio molecular dynamics, in a range of sizes where a core–shell morphology is observed. We analyze their structure and dynamics using state-of-the-art techniques, including unsupervised machine-learning nonlinear dimensionality reduction (sketch-map) for describing the similarities and differences among the range of sampled configurations. In the examined temperature range between 300 and 600 K, we find that whereas the gold nanoclusters exhibit continuous structural rearrangement, they are not amorphous. Instead, they clearly show persistent motifs: a cationic core of 1–5 atoms is loosely bound to a shell which typically displays a substructure resulting from the competition between locally spherical versus planar fragments. Besides illuminating the properties of core–shell gold nanoclusters, the present study proposes a set of useful tools for understanding their nature in operando

Inventários corporativos das emissões de gases de efeito estufa da Embrapa Hortaliças dos anos de 2008, 2009, 2010 e 2011.

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Research on the Portuguese building stock and its impacts on energy consumption – an average u-value approach

The article aims to evaluate the Portuguese building stock energy policies and strategy for energy saving in buildings among the EU members. It was found out the average heat transfer coefficients of the main structural elements of Portuguese Buildings and analyzed the U-values of this elements considering different time periods. The fundamentals of this study were funded by the Agency for Development and Innovation (ADI) and co-financed by the European Regional Development Fund (FEDER) through the Operational Program for Competitiveness Factors (POFC) assigned to the Building Physics and Construction Technology Laboratory with the reference SB Tool SPT_2011_4

Avaliação de unidades de reciclagem e compostagem de resíduos sólidos urbanos do Estado de São Paulo.

Diante do exposto, o presente trabalho vem subsidiar a avaliação IQC aplicada nas URC's visando estabelecer um índice mais confiável e completo. O trabalho determina uma nova classificação das unidades pelo cruzamento de informações sobre a avaliação do IQC com as dos parâmetros analisados (valores fora do limite estabelecido).Edited by Claudio da Rocha Brito; Melany M. Ciampi. EHWC 2006

Evolução dos teores de matéria orgânica do solo em uma área cultivada com hortaliças em sistemas conservacionistas.

O presente trabalho teve como objetivo verificar a evolução dos teores de matéria orgânica do solo (MOS) em Latossolo Vermelho Distrófico típico cultivado com hortaliças em sistemas conservacionistas há cinco anos

Características morfológicas e produção de matéria seca da palma forrageira cv. gigante adensada submetida à adubação nitrogenada.

Resumo: Sistemas intensivos de cultivo da palma forrageira no Rio Grande do Norte, com plantio adensado e irrigação, permitem cortes com idades inferiores ao manejo tradicional com dois anos. Dessa forma, objetivou-se avaliar as características morfológicas e a produção de matéria seca da palma forrageira cv. gigante adensada submetida à adubação nitrogenada, seis meses após o plantio. O delineamento experimental adotado foi em blocos ao acaso com quatro tratamentos (0, 38, 76 e 152 kg/N/ha) e seis blocos. Foi avaliado número de cladódios por planta, comprimento, largura, espessura, perímetro, área de cladódio (AC), índice de área de cladódio (IAC) e produção de material seca (PMS). Não houve diferença significativa (P>0,05) entre os tratamentos, apresentando valores médios de 5,5 cladódios/planta; 25 cm; 12 cm; 58 cm; 12,5 mm; 302 cm2; 0,15 e 2,6 t/ha, respectivamente para número de cladódios/planta, comprimento, largura, perímetro, espessura, AC, IAC e produção de matéria seca da palma forrageira gigante aos seis meses de idade. A aplicação da adubação nitrogenada não influenciou no crescimento e na produção de matéria seca da palma forrageira cv. gigante. [Morphological characteristics and dry matter yield of cactus pear cv. gigante dense planted with nitrogen fertilization]. Abstract: Cultivated intensive systems of cactus pear at Rio Grande do Norte State, dense sowed and with irrigation, allow cuts before the traditional management with two years of age. The aim of the study was to evaluate the morphological characteristics and dry matter yield of cactus pear cv. gigante dense planted subjected to nitrogen fertilization at six months after planting. The experimental design was randomized blocks with four treatments (0, 38, 76 and 152 kg N / ha) and six blocks. The evaluated parameters were: number of cladodes per plant, length, width, thickness, perimeter, area of cladodes (AC), cladodes area index (CAI) and dry matter yield (DMY). There was no significant difference (P> 0.05) among treatments, showing average values of 5.5 cladodes per plant, 25 cm, 12 cm, 58 cm, 12.5 mm, 302 cm2, 0.15 and 2.6 t / ha, respectively for number of cladodes per plant, length, width, perimeter, thickness, AC, IAC and dry matter yield of cactus pear cv. gigante at six months old. The nitrogen fertilization had no effect on growth and dry matter yield of cactus pear cv. gigante

Varietal thiols in white wines from portuguese grape varieties

Wines from Antão Vaz, Arinto, Fernão Pires, Verdelho da Madeira and Viosinho grape cultivars, from 2009 and 2010 vintages, were studied in order to characterize the volatile thiols profile, namely 4-mercapto-4-methyl-pentan-2-one (4MMP), 3-mercaptohexan-1-ol (3MH) and 3-mercaptohexyl acetate (3MHA). Volatile thiols profile of these wines was also compared to a Sauvignon blanc wine produced in Portugal. Besides sensory analysis, all wines were analyzed using GC coupled to different detectors, namely FID, FPD, MS and Olfactometry (GC-O). In all wines, GC-O analyses showed the existence of two olfactory zones related to the presence of 4MMP and 3MH. A third olfactory zone for 3MHA was only observed for the youngest wines. The wines produced from Portuguese cultivars presented aromatic intensities comparable or even higher than those obtained in the Sauvignon blanc wine. Indeed, 3MH was found in all wines and the highest amounts were observed in Antão Vaz, Arinto and Viosinho wines. In general, these findings are in agreement with those obtained by sensory analysis