Identification of viruses isolated from sewage,riverwater and coastal seawater in Barcelona

In a virological survey carried out in Barcelona, enteric viruses were isolated in samples from a sewage outlet (90% positive isolations), from two rivers (92 and 80% positive isolations) and from three beaches (17, 17 and 8% positive isolations). Viral identifications revealed that Poliovirus was detected in all kinds of water under study, the prevalent strain being vaccine type 3.     

Stress-dependent method for calculating the modulus improvement factor in geocell-reinforced soil layers

This paper presents an analytical method for determining the modulus improvement factor (MIF) in geocell-reinforced soil layers. Using a modified version of the hyperbolic soil model as a constitutive model, the method is developed based on the soil-reinforcement interaction relating nonlinear elastic soil behavior to the linear elastic response of the reinforcement. The proposed method, in an original way, explicitly takes into account the geometry of the geocell pocket, effects of soil and geocell-reinforcement stiffness, compaction-induced stresses, soil strength and strain compatibility. The method can be used both analytically and using simple and presented non-dimensional charts. Parametric analyses show that the reinforcement, soil relation and the stresses induced during the compaction procedure are the major factors influencing MIF. An evaluation using data from several laboratory, full-scale and field experiments in works is presented showing good predictive capability of proposed method. An application procedure for calculating MIF is presented.     

Functional properties of raw and heat processed cashew nut (Anacardium occidentale, L.) kernel protein isolates

The functional properties viz. solubility, water and oil absorption, emulsifying and foaming capacities of the protein isolates prepared from raw and heat processed cashew nut kernels were evaluated. Protein solubility vs. pH profile showed the isoelectric point at pH 5 for both isolates. The isolate prepared from raw cashew nuts showed superior solubility at and above isoelectric point pH. The water and oil absorption capacities of the proteins were slightly improved by heat treatment of cashew nut kernels. The emulsifying capacity of the isolates showed solubility dependent behavior and was better for raw cashew nut protein isolate at pH 5 and above. However, heat treated cashew nut protein isolate presented better foaming capacity at pH 7 and 8 but both isolates showed extremely low foam stability as compared to that of egg albumin.     

Simultaneous and Direct Determination of As, Bi, Pb, Sb, and Se and Co, Cr, Cu, Fe, and Mn in Milk by Electrothermal Atomic Absorption Spectrometry

Tungsten permanent modifier with coinjection of Pd(NO₃)₂ and W–Ru permanent modifiers are proposed for the direct and simultaneous determination of As, Bi, Pb, Sb, and Se (group 1) and Co, Cr, Cu, Fe, and Mn (group 2), respectively, in milk by graphite furnace atomic absorption spectrometry. The performance of modifiers was evaluated by means of thermal behavior of analytes, sensitivity, atomic signal profile, repeatability, graphite tube lifetime, and background intensity. An air-assisted pyrolysis step was necessary to quantitative elimination of the organic matter. After methods optimization, 14 commercial milk samples were analyzed. The found concentrations of As, Bi, Pb, Sb, Se, Co, and Cr were lower than their limit of detection (2.13, 2.21, 1.49, 1.63, 2.05, 1.0, and 1.2 μg L⁻¹, respectively). Concentrations of Cu, Fe, and Mn were in the 1.58–5.74 μg L⁻¹, 9.79–49.3 μg L⁻¹, and 2.25–4.08 μg L⁻¹ intervals, respectively. The limits of detection for Cu, Fe, and Mn were 1.7, 5.3, and 2.0 μg L⁻¹, respectively. The accuracy of methods was checked after analysis of two milk standard materials. Results for Cr, Cu, Fe, Mn, Pb, and Mn were in agreement with certified values of SRMs at the 95% confidence level. Accuracy was also evaluated by addition–recovery tests and recoveries in the 86–127% range were obtained for all elements. The use of pretreat platform of graphite tubes with W or W–Ru allowed enlarging the lifetime of atomizer in 750 heating cycles.     

Use of the stable isotope (57) Fe to track the efficacy of the foliar application of lignosulfonate/Fe(3+) complexes to correct Fe deficiencies in cucumber plants

BACKGROUND: During the last decade, environmental concerns regarding the use of recalcitrant synthetic chelates to overcome iron chlorosis has increased and new ligands such as lignosulfonates (LS) have been evaluated. However, the efficacy of these products is variable. In this work a hardwood (eucalyptus) and softwood (spruce) LS were compared to try to relate their physico‐chemical characteristics and their efficacy. Also two more products derived from the eucalyptus lignosulfonate were tested. RESULTS: All the LS tested presented a good ability to complex Fe, but only the spruce LS was capable to maintain significant amounts of soluble Fe above pH 8. According to the FTIR data, structural changes related to the Fe source (Fe²⁺ or Fe³⁺) used to form the complex occurred in the LS molecule and might influence their efficacy. Cucumber (Cucumis sativus L. cv Ashley) chlorotic plants were used to test lignosulfonate efficacy when applied through foliar sprays in comparison with FeSO₄ and EDTA/⁵⁷Fe³⁺. The ⁵⁷Fe content of plants sprayed with LS was very low in respect to the EDTA treatment, but this was not reflected in the biomass and re‐greening rates. Eucalyptus LS modifications improve its efficacy for iron chlorosis recovery to levels similar to those found for the spruce LS. Two applications of the LS are recommended. CONCLUSIONS: Lignosulfonates did not require surfactants for their application; they did not burn the leaves, and had a stimulating effect on the vegetative growth of the plants. So these by‐products could be a good alternative when applied through foliar sprays for cucumber plants. Copyright © 2010 Society of Chemical Industry     

An alternative route to produce easily activated nanocrystalline TiFe powder

In this paper, an alternative process route to produce active nanocrystalline TiFe compound was investigated. First, TiH₂ and Fe powders were dry co-milled in a planetary ball mill for 5–40 h. TiH₂ was selected as precursor powder, instead of Ti powder, due its fragility, which has proved to be beneficial to decrease powders adherence on milling tools. In terms of loose powder mass, milling yields ranged from 90 to 95 wt.%. Next, milled powders were post-heated at 873 K under dynamic high-vacuum for TiFe synthesis reaction. First hydrogen absorption was verified in situ during the cooling process of samples (until the room temperature), being the amount of hydrogen absorbed and desorbed by this samples measured by automated Sievert's apparatus, under constant hydrogen flow rate of 9 cm³. min^-1 (dynamic measurements). Besides to allowing the first absorption in situ, the investigated process route also allowed the production of the non-stoichiometric TiFe compound (rich in Ti) in samples milled for shorter times (5 and 10 h), both characteristics associated with maintaining the mechanical compound activity. Each sample absorbed hydrogen at 2 MPa during the cooling process, requiring no additional thermal activation cycles, since the samples milled for shorter times (mainly for 10 h) could absorb hydrogen for the first time more easily. However, the samples milled for longer times (25 and 40 h) shown better results in terms of reversible and storage capacities (0.73 and 0.94 wt.%, respectively).     

Improved quantum-inspired evolutionary algorithm with diversity information applied to economic dispatch problem with prohibited operating zones

The objective of the economic dispatch problem (EDP) of electric power generation, whose characteristics are complex and highly nonlinear, is to schedule the committed generating unit outputs so as to meet the required load demand at minimum operating cost while satisfying all unit and system equality and inequality constraints. Recently, as an alternative to the conventional mathematical approaches, modern meta-heuristic optimization techniques have been given much attention by many researchers due to their ability to find an almost global optimal solution in EDPs. Research on merging evolutionary computation and quantum computation has been started since late 1990. Inspired on the quantum computation, this paper presented an improved quantum-inspired evolutionary algorithm (IQEA) based on diversity information of population. A classical quantum-inspired evolutionary algorithm (QEA) and the IQEA were implemented and validated for a benchmark of EDP with 15 thermal generators with prohibited operating zones. From the results for the benchmark problem, it is observed that the proposed IQEA approach provides promising results when compared to various methods available in the literature.     

Biohydrogen production in anaerobic fluidized bed reactors: Effect of support material and hydraulic retention time

This study evaluated two different support materials (polystyrene and expanded clay) for biohydrogen production in an anaerobic fluidized bed reactor (AFBR) treating synthetic wastewater containing glucose (4000 mg L⁻¹). The AFBRs contained either polystyrene (R1) or expanded clay (R2) as support materials were inoculated with thermally pre-treated anaerobic sludge and operated at a temperature of 30 °C and a pH of approximately 5.5. The AFBRs were operated with a range of hydraulic retention times (HRTs) between 1 and 8 h. For R1 with an HRT of 2 h, the maximum hydrogen yield (HY) was 1.90 mol H₂ mol⁻¹ glucose, with 0.805 mg of biomass (as total volatile solids, or TVS) attached to each g of polystyrene. For R2 operated at an HRT of 2 h, the maximum HY was 2.59 mol H₂ mol⁻¹ glucose, with 1.100 mg of attached biomass (as TVS) g⁻¹ expanded clay. The highest hydrogen production rates (HPR) were 0.95 and 1.21 L h⁻¹ L⁻¹ for R1 and R2, respectively, using an HRT of 1 h. The H₂ content increased from 16–47% for R1 and from 22–51% for R2. No methane was detected in the biogas produced throughout the period of AFBR operation. These results show that the values of HY, HPR, H₂ content, and g of attached biomass g⁻¹ support material were all higher for AFBRs containing expanded clay than for reactors containing polystyrene.