Texture and colour kinetics of change in blanched carrots

Five Isothermal heating experiments, at different temperatures and at predetermined time intervals, were carried out on diced carrots. The objective of this study was to determine the degradation kinetics of colour (a and a/b parameters) and texture (work and maximum force) along blanching. The best model to fit the degradation kinetic data was the fractional conversion and the temperature effect was well described by the Arrhenius equation. The k 800c and Ea values were 0.2, 0.05, 0.5 and 0.05 min -1 and 12x103, 18x103, 49x103 and 192x103J/mol, respectively for a, a/b, maximum force and work

Mechanical properties and cytotoxic evaluation of the Ti-3Nb-13Zr alloy

Ti-13Nb-13Zr is a new titanium alloy that was originally developed for medical implant applications. This alloy combines a low elastic modulus, high strength, excellent hot and cold workability, and superior corrosion resistance. Research on this alloy has shown that the mechanical properties can be controlled over a significant range through hot working, heat treatment and cold-working. The present study describes the mechanical properties and cytotoxic evaluation of the Ti-13Nb-13Zr alloy, which was produced by furnace arc melting in argon atmosphere. The elemental constituents were unalloyed Ti, Nb and Zr sheets. The obtained ingots, which initial diameter were about 15 mm, have undergone sequences of cold-working and heat treatments in order to achieve a final diameter of 6 mm. The tensile strength of Ti-13Nb-13Zr achieved 1270 MPa (cold-worked – 60% reduction in area) and 860 MPa after heat treatment (60% reduction in area + 1000 o C/1h + water quenched). The elastic module were 52 GPa and 60 GPa respectively. Furthermore, the toxic effect of this alloy on cells was evaluated by a cytotoxicity test, a quantitative method of colony suppression assay using Chinese Hamster Ovary (CHO) cultured cells in contact with diluted extracts of the biomaterials. The results showed that Ti-13Nb-13Zr alloy obtained by furnace arc melting isn’t cytotoxic.Peer Reviewe

Geochemistry of groundwater from Graciosa Island (Azores): A contribution to the hydrothermal system conceptual model

Graciosa island is located in the Azores Archipelago, along the so-called Terceira Rift, a major tectonic structure that makes the NE boundary of the Azores Plateau. In general terms, it includes a basaltic plataform on the NW and a silicic poligenetic volcano with caldera on the SE, the Graciosa Caldera Volcano. This volcano has produced significant tephra falls, pyroclastic flows, lahars, and lava flows, both of basaltic s.l. and trachitic s.l. composition. The hydrothermal system shows fumarolic emissions inside the volcano caldera and thermal springs located along the shoreline. This system is exploitated in a thermal building through shallow and deep (110 m) boreholes, near the coast. In Graciosa two types of Na-Cl groundwater systems can be identified: 1) a cold one emerging at springs and exploited by wells for public water supply, and 2) a hydrothermal system with temperatures around 40-44 °C. The cold groundwaters have pH higher than 7 and different degree of mineralization, according to the proximity to the sea. The thermal waters show mixing with seawater, pH varying between 6.20 and 6.94, 166 mg/L of SiO2, and significant concentration of metals, such as Mn, Fe, Co, Ni, Cu and Zn. The thermal water mineralization varies strongly, showing EC from 8.87 mS/cm (shallow water) to 47.4 mS/cm (deeper water). The higher mineralized water is rich in CO2(g), with 2130 mg/L of total dissolved CO2. Geothermometers application reveals aquifer temperature around 167 °C and immature/mixed waters, not reaching complete equilibrium with reservoir rock. The geochemistry of the thermal waters indicates the occurrence of seawater/host rock interaction processes at high temperature and slightly acid conditions, favored by CO2(g) input, and a different degrees of mixing with cold and shallow groundwaters

B(E1) Strengths from Coulomb Excitation of 11Be

The $B$(E1;$1/2^+\to1/2^-$) strength for $^{11}$Be has been extracted from intermediate energy Coulomb excitation measurements, over a range of beam energies using a new reaction model, the extended continuum discretized coupled channels (XCDCC) method. In addition, a measurement of the excitation cross section for $^{11}$Be+$^{208}$Pb at 38.6 MeV/nucleon is reported. The $B$(E1) strength of 0.105(12) e$^2$fm$^2$ derived from this measurement is consistent with those made previously at 60 and 64 MeV/nucleon, i n contrast to an anomalously low result obtained at 43 MeV/nucleon. By coupling a multi-configuration description of the projectile structure with realistic reaction theory, the XCDCC model provides for the first time a fully quantum mechanical description of Coulomb excitation. The XCDCC calculations reveal that the excitation process involves significant contributions from nuclear, continuum, and higher-order effects. An analysis of the present and two earlier intermediate energy measurements yields a combined B(E1) strength of 0.105(7) e$^2$fm$^2$. This value is in good agreement with the value deduced independently from the lifetime of the $1/2^-$ state in $^{11}$Be, and has a comparable p recision.Comment: 5 pages, 2 figures, accepted for publication in Phys. Lett.

Impacts of climate and land use changes on the hydrological and erosion processes of two contrasting Mediterranean catchments

The impacts of climate and land use changes on streamflow and sediment export were evaluated for a humid (São Lourenço) and a dry (Guadalupe) Mediterranean catchment, using the SWAT model. SWAT was able to produce viable streamflow and sediment export simulations for both catchments, which provided a baseline for investigating climate and land use changes under the A1B and B1 emission scenarios for 2071–2100. Compared to the baseline scenario (1971–2000), climate change scenarios showed a decrease in annual rainfall for both catchments (humid: − 12%; dry: − 8%), together with strong increases in rainfall during winter. Land use changes were derived from a socio-economic storyline in which traditional agriculture is replaced by more profitable land uses (i.e. corn and commercial forestry at the humid site; sunflower at the dry site). Climate change projections showed a decrease in streamflow for both catchments, whereas sediment export decreased only for the São Lourenço catchment. Land use changes resulted in an increase in streamflow, but the erosive response differed between catchments. The combination of climate and land use change scenarios led to a reduction in streamflow for both catchments, suggesting a domain of the climatic response. As for sediments, contrasting results were observed for the humid (A1B: − 29%; B1: − 22%) and dry catchment (A1B: + 222%; B1: + 5%), which is mainly due to differences in the present-day and forecasted vegetation types. The results highlight the importance of climate-induced land-use change impacts, which could be similar to or more severe than the direct impacts of climate change alone

Análise das variáveis que influenciam a adesão das empresas ao índice BM&F Bovespa de sustentabilidade empresarial

This article examines the variables that influence the decision of firms to adhere to the Corporate Sustainability Index of the São Paulo Stock Exchange (Bovespa). We investigated the following variables: firm size, sector of activity, shareholding concentration, location of controlling shareholder, issuance of ADRs and public-sector versus private-sector control. The initial data came from selecting the 150 most liquid shares listed for trading at the BM&F Bovespa, with transactions during at least 50% of the trading sessions in the period from June 2006 to June 2007. From these, we chose 124 firms to compose the final sample, which we classified into firms included and not included in the hypothetical portfolio making up the sustainability index from December 2007 to November 2008. We applied the logit multiple linear regression model to assess the contribution of each variable to explain the chance of adhering to the index. The results suggest there is a statistically significant indication that size and sector influence this inclusion, while the other variables statistically did not have any influence. Key words: corporate social responsibility, corporate sustainability, sector of activity, firm size.Este estudo objetiva analisar as variáveis que influenciam a adesão das empresas ao Índice Bovespa de Sustentabilidade Empresarial (ISE). Foram verificadas as variáveis: tamanho da empresa, setor de atividade, concentração acionária, localização do controle acionário, o fato de a empresa ser emissora de ADR e ser de propriedade estatal. A coleta inicial de dados baseou-se na seleção das 150 ações mais líquidas listadas na BM&F Bovespa presentes em pelo menos 50% dos pregões no período de junho de 2006 a junho de 2007. Foram selecionadas 124 empresas para a composição da amostra. A partir dessa amostra, verificaram-se as empresas detentoras das ações que se enquadraram ou não na carteira teórica anual do ISE – dezembro 2007/novembro 2008. Foi aplicado o modelo Logit de regressão linear múltipla para avaliar a contribuição de cada variável explicativa na chance de adesão ao índice. Concluiu-se que, estatisticamente, há indícios de que o tamanho das empresas e o setor de atividade são determinantes que influenciam a adesão das empresas ao ISE. As variáveis localização, concentração acionária, ser emissora de ADR e ser de propriedade estatal, estatisticamente, não apresentaram relação de influência para a inclusão das empresas ao ISE. Palavras-chave: responsabilidade social corporativa, sustentabilidade empresarial, setor de atividade, tamanho das empresas

Maximally-localized Wannier functions for entangled energy bands

We present a method for obtaining well-localized Wannier-like functions (WFs) for energy bands that are attached to or mixed with other bands. The present scheme removes the limitation of the usual maximally-localized WFs method (N. Marzari and D. Vanderbilt, Phys. Rev. B 56, 12847 (1997)) that the bands of interest should form an isolated group, separated by gaps from higher and lower bands everywhere in the Brillouin zone. An energy window encompassing N bands of interest is specified by the user, and the algorithm then proceeds to disentangle these from the remaining bands inside the window by filtering out an optimally connected N-dimensional subspace. This is achieved by minimizing a functional that measures the subspace dispersion across the Brillouin zone. The maximally-localized WFs for the optimal subspace are then obtained via the algorithm of Marzari and Vanderbilt. The method, which functions as a postprocessing step using the output of conventional electronic-structure codes, is applied to the s and d bands of copper, and to the valence and low-lying conduction bands of silicon. For the low-lying nearly-free-electron bands of copper we find WFs which are centered at the tetrahedral interstitial sites, suggesting an alternative tight-binding parametrization.Comment: 13 pages, with 9 postscript figures embedded. Uses REVTEX and epsf macro