The effects of copper and high sugar concentrations on growth, fermentation efficiency and volatile acidity production of different commercial wine yeast strains

The effect of high sugar concentrations or the presence of copper residues on fermentation efficiency and volatile acid (VA) production were examined for selected commercial wine yeast strains. Fermentation rate as measured by accumulated mass loss appeared to be least affected by high sugar concentrations during the first few days of fermentation for strains VIN13, WE14, N96 and RJ11. It was, however, only fermentations using VIN13, WE372, N96 and L2056 that contained less than 11 g/L fructose after 21 days. VIN13 and RJ11 produced the lowest VA in the 21^o, 25^o and 28^oBrix musts. Fermentation efficiency of six strains was also studied in must containing 0.25 mM Cu²⁺. Results indicated that strains NT50, Collection Cépage Cabernet (CC) and D80 were not significantly affected, whereas VIN13, NT112 and RJ11 contained significantly more glucose and fructose after fermentation in the must containing copper. Copper addition also increased VA production, with strains RJ11 and NT50 being the most affected.     

Lot sizing algorithms with applications to engineering and economics

This paper presents two new solution procedures for a deterministic lot size problem, a matrix algorithm and a heuristic matrix method. The algorithm is based on the dual of a linear programming model formulation of the lot size problem, and it provides optimal solutions even in the general case of time-varying parameters. A comparison of the efficiency of the new solution procedures with well-known methods is developed. New applications of the techniques described within the fields of engineering (optimal design of a pump-pipe system) and economics (a model for import-planning) are referred to.     

Estimating water storage changes and sink terms in Volta Basin from satellite missions简

The insufficiency of distributed in situ hydrological measurements is a major challenge for hydrological studies in many regions of the world. Satellite missions such as the Gravity Recovery and Climate Experiment （GRACE） and the Tropical Rainfall Measurement Mission （TRMM） can be used to improve our understanding of water resources beyond surface water in poorly gauged basins. In this study we combined GRACE and TRMM to investigate monthly estimates of evaporation plus runoff （sink terms） using the water balance equation for the period from January 2005 to December 2010 within the Volta Basin. These estimates have been validated by comparison with time series of sink terms （evaporation plus surface and subsurface runoff） from the Global Land Data Assimilation System （GLDAS）. The results, for the period under consideration, show strong agreement between both time series, with a root mean square error （RMSE） of 20.2 ram/month （0.67 mm/d） and a correlation coefficient of 0.85. This illustrates the ability of GRACE to predict hydrological quantities, e.g. evaporation, in the Volta Basin. The water storage change data from GRACE and precipitation data from TRMM all show qualitative agreement, with evidence of basin saturation at approximately 73 mm in the equivalent water column at the annual and semi-annual time scales.     

Climbing the steps of viral atomic force microscopy: visualization of Dengue virus particles

In recent years, the application of atomic force microscopy (AFM) to biological systems has highlighted the potential of this technology. AFM provides insights into studies of biological structures and interactions and can also identify and characterize a large panel of pathogens, including viruses. The Flaviviridae family contains a number of viruses that are important human and animal pathogens. Among them, Dengue virus causes epidemics with fatal outcomes mainly in the tropics. In this study, Dengue virus is visualized for the first time using the in air AFM technique. Images were obtained from a potassium-tartrate gradient-purified virus. This study enhances the application of AFM as a novel tool for the visualization and characterization of virus particles. Because flavivirus members are closely related, studies of the morphologic structure of the Dengue virus can reveal strategies that may be useful to identify and study other important viruses in the family, including the West Nile virus.     

The inverse internal model†

The paper studies the servo problem when a disturbance signal is applied at the compensator's input. It is shown that the compensator must provide an ‘ inverse internal model’ (defined in a precise sense) of the disturbance signal besides the (direct) internal model of the signal to be tracked.     

The use of Artificial Neural Networks to estimate seismic damage and derive vulnerability functions for traditional masonry

This paper discusses the adoption of Artificial Intelligence-based techniques to estimate seismic damage, not with the goal of replacing existing approaches, but as a mean to improve the precision of empirical methods. For such, damage data collected in the aftermath of the 1998 Azores earthquake (Portugal) is used to develop a comparative analysis between damage grades obtained resorting to a classic damage formulation and an innovative approach based on Artificial Neural Networks (ANNs). The analysis is carried out on the basis of a vulnerability index computed with a hybrid seismic vulnerability assessment methodology, which is subsequently used as input to both approaches. The results obtained are then compared with real post-earthquake damage observation and critically discussed taking into account the level of adjustment achieved by each approach. Finally, a computer routine that uses the ANN as an approximation function is developed and applied to derive a new vulnerability curve expression. In general terms, the ANN developed in this study allowed to obtain much better approximations than those achieved with the original vulnerability approach, which has revealed to be quite non-conservative. Similarly, the proposed vulnerability curve expression was found to provide a more accurate damage prediction than the traditional analytical expressions.     

Unity and non-unity feedback: a comparison†

The paper compares the unity feedback with the non-unity feedback servo problem from the point of view of sensitivity and the minimum order of the realization. It is proved that the non-unity feedback solution has smaller sensitivity ‘on the band of interest’ and that the ‘dimension’ (defined in a precise sense) of the non-unity feedback solution is never smaller than that of the unity feedback solution.     

A methodology for cellular manufacturing design

A two-phase methodology is presented as an aid to organizing job shop production in a cellular manufacturing system. The first phase (selection/assignment phase) selects the machines to be kept on the shop floor and assigns parts to the machines retained. The second phase (partition/reassignment phase) establishes a partition of the set of parts and corresponding cells of machines and reassigns some of the operations with a view to eliminating some intercell material movements. This phase is repeated until a partition meeting the operator's requirements is obtained. The results obtained with this method on several examples found in the literature are consistently equivalent to or even better than those hitherto proposed, in terms of intercell moves.     

Two-proton sequential decay from excited states of 18Ne

Two-proton radioactivity from 18Ne is discussed in terms of sequential decay. The branch ratios for one- proton emission from excited states are calculated, which including spectroscopic factors, obtained from a Shell- model calculation with realistic interactions. The branch ratios show that the two-proton emission from the 1 state of 16Ne at 7.94 MeV is most likely to go through the sequential decay. The same mechanism is discussed for other excited states at higher energy by different interactions.