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The effectiveness of five commercial disinfectants used in the food industry was evaluated against different strains isolated from foodborne outbreaks (E. coli O157:H7, Salmonella spp. and L. monocytogenes) and a collection strain (S. aureus) in an aqueous suspension medium. The disinfectants evaluated included quaternary ammonium compounds, aldehydes, hydrogen peroxide and peracetic acid, clorhexidine and a tertiary alkylamine. In the absence of organic matter, all the disinfectants tested were effective with an exposure time of 10 min at the lowest concentration recommended by the manufacturer. However, in the presence of organic matter their effectiveness decreased. The most effective disinfectant against pathogenic bacteria tested was a quaternary ammonium compound based disinfectant combined with non-ionic surfactants, polyphosphates and alkaline salts. The least effective ones were disinfectants containing tertiary alkylamine, peracetic acid and hydrogen peroxide.
Abstract
The nickel-titanium alloys are usually known as Shape Memory alloys because of their ability to return to some previously defined shape or size when subjected to the appropriate thermal procedure. Mechanical properties of a nickel titanium wire were investigated by DMTA using cylindrical tension mode. The Young"s modulus, the maximum strain and residual deformation have been calculated. Recovery of previously deformed samples was observed in constant stress temperature ramp tests. Relaxation stress behaviour at temperatures above the austenitic transformation has been studied. The strain and frequency ranges of linear response have been determined by dynamic experiments. Strain amplitude of 0.1% and frequency of 1 Hz have been chosen for the temperature ramp dynamic experiments. A big change between 65 and 95C is observed in the storage modulus. The values of E' at temperatures below and above the transition are essentially constant. Finally, the effects of the frequency at different temperatures have been examined.
Abstract
Phosphate rocks are used for phosphoric acid production, which is the basis of agricultural phosphate fertilizers. It is known that phosphate ores contain, due to geological reasons, important amounts of natural radioactivity, mainly U-isotopes and daughters. By studying a specific case in Southwestern Spain, it is shown that the operation of phosphate fertilizer factories clearly enhance the natural radiation levels of its close environment. Levels of U-, Th-isotopes, and other natural radionuclides are given for a wide set of different samples, which support such a conclusion. In addition, the study of isotopic ratios gives information on the environmental behavior of such radionuclides.
Activity and functional diversity of rhizosphere bacterial communities and fungal composition were studied in order to assess the effects of different genotypes (N8035, N224 and N8637) of Arabidopsis thaliana on these communities growing in different soils. Genotype effect and soil effect were studied independently. Also, the interactions between both factors (genotypes and soils) were considered. The activity was determined by thymidine and leucine incorporation analysis, and Biolog ECO plates were used to study bacterial functional diversity. Additionally, fungi groups (genera and/or species) were studied in the different rhizospheres. Statistical differences on thymidine incorporation between plant genotypes were only found in two of the soils. In addition, functional diversity (measured by Shanonn-Weaver index), showed statistical differences only in soil 1 for line N8035 (line B) vs . the other lines. Redundancy analysis (RDA) performed with Biolog data indicated and important effect of soil type, but also an effect of genotype since line N8035 (line B) was separated from the other lines within each soil in the RDA ordination, in spite of genotypic differences between them were minimum. Furthermore, carboxylic acids and amino acids were found to be the Biolog plate substrates with more influence in samples ordination in the Redundancy Analysis (RDA). However, fungi seem to be less labile to plant selection than bacteria probably due to a lower turn-over time of fungi than bacteria coupled with the short phenology of Arabidopsis . In this paper, plant-soil-micro-organism relationships in the rhizosphere were studied, and the complex interactions between them were highlighted. More studies are necessary to go deep in these interactions and to be able to asses the impact of genetically modified plants.
Abstract
A survey on the effect of ionic liquids (ILs) over the thermal stability of a heavy Mexican oil was performed. ILs used were based on [Cnim]+ and [Cnpyr]+ organic cations with FeCl4 − metal anion. Mixtures of heavy crude oil (HCO) with ILs show three oxidation zones: low temperature oxidation (LTO), full deposition (FD) and high temperature oxidation (HTO). Thermal stability and mass loss decrease in the LTO zone but increase in the FD and HTO zones for every ILs used. The activation energy of the oxidation is influenced by the ILs in the HTO zone. It decreases when increasing the size of the organic radical substitute in the cation of the ILs while it increases with the presence of hydroxyl groups. The influence of electronic structure and reactivity indexes are rationalized to understand the variations of activation energy obtained of the reaction systems. Among all cations used, cation-3 (IL-3) shows the greater value of HOMO-LUMO gap as well as the lower activation energy.
Abstract
Here we study the relationship between journal quartile rankings of ISI impact factor (at the 2010) and journal classification in four impact classes, i.e., highest impact, medium highest impact, medium lowest impact, and lowest impact journals in subject category computer science artificial intelligence. To this aim, we use fuzzy maximum likelihood estimation clustering in order to identify groups of journals sharing similar characteristics in a multivariate indicator space. The seven variables used in this analysis are: (1) Scimago Journal Ranking (SJR); (2) H-Index (H); (3) ISI impact factor (IF); (4) 5-Year Impact Factor (5IF); (5) Immediacy Index (II); (6) Eigenfactor Score (ES); and (7) Article Influence Score (AIS). The fuzzy clustering allows impact classes to overlap, thereby accommodating for uncertainty related to the confusion about the impact class attribution for a journal and vagueness in impact classes definition. This paper demonstrates the complex relationship between quartiles of ISI impact factor and journal impact classes in the multivariate indicator space. And that several indicators should be used for a distinct analysis of structural changes at the score distribution of journals in a subject category. Here we propose it can be performed in a multivariate indicator space using a fuzzy classifier.
Soil structure stability depends on several factors and its assessment is conducted using different methods and prediction indices. One of the indicators is soil organic matter (SOM), since this helps to keep mineral particles together against destabilizing forces such as wetting and raindrop impact. However, previous studies have emphasized the relationship between aggregate stability and SOM content without considering its type or quality. Therefore, in this study the association between the quality and content of SOM and the structural stability of the surface layer was evaluated in three soils used for growing malting barley in the southern part of Hidalgo State, Mexico. With simple random sampling nine observation points were selected in each soil, where samples were taken in order to determine the stable aggregate size distribution, particle size distribution, content and fractionation of SOM, and the prediction indices of surface sealing and crusting derived from these characteristics. The soils showed low structural stability (except in Apan), as shown by the percentage runoff recorded in the field. There was a close association between the size (from 4 to 2 mm and <0.25 mm) of water-stable aggregates and the different fractions of SOM, while the fulvic acid (FA) fraction had a negative relationship with smaller aggregates (R = −0.84). Finally, it was found that only the FAO crusting index was able to predict the structural stability level in the soil.
Several approaches have been made in the context of data assimilation in order to improve the estimates of electron density. The key point is to combine different types of data that offer complementary information, thus allowing to obtain a three dimensional description of the electronic content of the ionosphere. In this paper a data assimilation scheme will be proposed in which the complementarity of information will be given by the ground GPS data (horizontal variation) and vertical profiles derived from ionosonde data (vertical variation). The results of this assimilation scheme will be verified by an external source of data, the GPS data gathered from receiver onboard GPSMET, a low earth orbiter at 750km. This comparison will show the feasability of this assimilation scheme. Moreover it will be shown how this method is able to provide with valuable information about the topside ionosphere by means of comparison with the vertical profiles retrieved from Radio Occultations using Abel inversion. To do this the approach of Abel inversion based on a separability hypothesis will be explained, and it will be compared with the classical approach that assumes spherical symmetry.
Abstract
Monotone normality is usually defined in the class of T 1 spaces. In this paper new characterizations of monotone normality, free of T 1 axiom, are provided and it is shown that in this context it is not a hereditary property. Also, a Tietze-type extension theorem for lattice-valued functions for this class of spaces is given.
Abstract
Thermal degradation of orange peel was studied in dynamic air atmosphere by means of simultaneous TG-DSC and TG-FTIR analysis. According to the obtained thermal profiles, the orange peel degradation occurred in at least three steps associated with its three main components (hemicellulose, cellulose and lignin). The volatiles compounds evolved out at 150–400 °C and the gas products were mainly CO2, CO, and CH4. A mixture of acids, aldehydes or ketones C=O, alkanes C–C, ethers C–O–C and H2O was also detected. The E α on α dependence reveled the existence of different and simultaneous processes suggesting that the combustion reaction is controlled by oxygen accessibility, motivated by the high evolution low-molecular-mass gases and volatile organic compounds. These results could explain the non-autocatalytic character of the reactions during the decomposition process.
