1,298 research outputs found

    Trend Analysis of Air Quality Index in Catania from 2010 to 2014

    Get PDF
    Abstract Information on air quality in urban areas represents an important objective to raise awareness and participation of citizens towards those measures aimed at containing and reducing vehicular traffic. For several years at the international level, evaluation procedures have been adopted by indices. One of the first synthetic indices, adopted by the United States Environmental Protection Agency (US-EPA), was the Pollution Standard Index (PSI). In 1999, the EPA replaced the PSI index with Air Quality Index (AQI), which includes two new sub-indices, the ozone at ground level and fine particulate. Despite the European Decisions 97/101/EC and 2001/752/EC, have established an exchange of information from networks and individual stations measuring ambient air pollution in Member States, the use of a single index has not yet been defined that allows you to compare different realities. This heterogeneity emerges in Italy as well, where only a few Environmental Protection Agencies disclose indexes to inform citizens. In this article, the Air Quality Index (AQI) currently used by the United States Environmental Protection Agency has been applied to the metropolitan city of Catania, in order to analyze the level of pollution daily from 2010 to 2014. Through the use of the AQI it was possible to synthesize in a single daily value, concentrations of major pollutants in urban areas (NO2, O3, CO, SO2, PM10) for the entire period. For the calculation procedure of the AQI, the data concentrations were provided by Municipal Ecology and Environment Office. The data relates to three monitoring stations, whose locations have not changed over the years. This also made it possible to evaluate the change in frequency of AQI agglomerations where the monitoring units have been positioned. The value obtained by the AQI for each station has been ranked in six levels of pollution; each level has been associated with a particular coloring allowing this information to be more intuitive. Lastly, it was possible to reach the air quality assessment in urban environment from the frequency variations of each level derived from the year 2010 until 2014

    Customer satisfaction in the Brazilian Fast Food Franchise Segment

    Get PDF
    In a market with great competition, store image associated with quality and brand  become an important competitive tool, meanly when it was associated to perceived customer satisfaction. The main objective of this study was to analyze the influence of image, brand and quality on customer satisfaction in the fast food segment. Data analysis was conducted through multivariate techniques to verify the significance of the relationship between variables analyzing two of the five biggest fast food channels in Brazil. The results showed that brand and quality were the most valued variables according to perceived customer satisfaction. In the model used, brand presented the greatest explanatory power. Based on the multiple coefficient of determination (adjusted R2), quality, image and brand as a group explained about 62.7% (Franchise 1) and 61.3% (Franchise 2) of the search for satisfaction, being that only quality and brand were statistically significant.

    Experimental Analysis of a Plume Dispersion Around Obstacles

    Get PDF
    Abstract Nowadays, transport and deposition of aerosol particles (PM 2.5 , PM 10 , TSP) caused by industrial plants, environmental applications and transports, are of great concern to public health. Despite the establishment by the European Union of emission standards (European directive 2008/50/CE e.g) to control the limits of particulates in the air, the emissions by industrial plants are still not accurately monitored. In particular, the interaction between plume dispersion and obstacles, such as buildings, is not currently well studied. A lot of theoretical researches were carried out in this field with a lack of experimental data comparison. This paper focuses on a laboratory work made to better explain the interaction of a continuous plume released from a point source and various obstacles. First of all a vertical pipe was reproduced, a continuous aerosol emitter was characterized in terms of a specified and controlled mass flow and the ratio between smoke emission and the total suspended particulates thanks to use of the certified gravimetric calculation of PM 10 . The experimental campaigns were conducted by means of a wind tunnel all the data collected were validated. The characterization of plume was made by the use of several sensors and calculation of velocity in several points of the field. Moreover, the plume dispersion was studied also by using digital image analysis. It was then investigated downwind the influence of obstacles of various shapes and distances from source in terms of aerosol concentration in several points

    Antiulcer Activity of Salvadora persica on Experimental ASA-Induced Ulcer in Rats: Ultrastructural Modifications

    Get PDF
    The lyophilized decoction of Salvadora persica L. roots possesses a significant protective effect on ulceration induced by ethanol, indomethacin and cold restraint stress in rats. In this work, we study the effect of chronic intragastric administration of S. persica decoction on experimental acetylsalicylic acid (ASA)-induced ulcer in rats. The ulcer index significantly decreased (U.I. 0.9 ± 1.6; P < 0.05) after treatment with a lyophilized decoction of S. persica (500 mg/kg, os), once daily for seven days, with respect to controls (U.I. 11.4 ± 2.3). The modification of gastric mucosa was observed by transmission electronic microscopy (TEM) confirming this result. In fact, in treated rats, the mucosa recovered to normal distribution. After S. persica treatment, some changes were detected in profiles of various cytoplasm organelles of parietal cells. Particularly, the intracellular canaliculi show an enlarged lumen with an increase in the number and length of microvilli. These morphological features of ..

    Theoretical and Experimental Study of Gaussian Plume Model in Small Scale System

    Get PDF
    Abstract Atmospheric dispersion pollution modelling is of great and actual concern in the scientific international community. Many dispersion models have been developed and used to estimate the downwind ambient concentration of air pollutants from sources such as industrial plants, vehicular traffic or accidental chemical release. Among them, Gaussian model is perhaps the most commonly used model type. It is often used to predict the dispersion of air pollution plumes originated from ground-level or elevated sources. In this research an experimental campaign was carried out in the wind tunnel of the Industrial Engineering Department of University of Catania. It was tested an emission plume of particulate matters and the concentrations of PM 10 were evaluated in several points downwind beyond the emitter. Both the wind velocity and PM 10 mass flow were varied in order to test the differences in terms of PM10 concentrations in the sampling points. A Gaussian plume mathematical model was developed according the boundaries conditions of the experimental campaign. The results of the model were compared with experimental ones in order to identify the limits and the advantages of this model in such a small scale system

    Optimizing HIV therapy. A consensus project on differences between cytidine analogues and regime compactness

    Get PDF
    The identification of the most effective HAART regimens in different clinical settings is still an issue. The aim of the study was to analyze how the compactness of HAART regimens is perceived and if differences between lamivudine (3TC) and emtricitabine (FTC) do exist according to a panel of Italian HIV/AIDS clinicians, using the Delphi method

    A segmentation proposal to the consumers’ brazilian beer sector / Proposta de segmentação do mercado brasileiro de cerveja

    Get PDF
    The objective of this research was to identify the different segments of beer consumers based on the behavior presented during the purchase decision process. A field survey was carried out with a convenience sample of 422 respondents, using questionnaires, available in the authors' relationship networks. In the data analysis, the statistical technique cluster analysis was applied, which allowed the identification of four consumer segments: high involvement consumers, medium consumption consumers, occasion buyers, and low consumption consumers. Results obtained from the investigation show that consumers with high levels of involvement (Group 1) seek a lot of information before consumption. For consumers of average consumption (Group 2), the search for knowledge and references on beers is limited to previous experiences they had and to friends, and they choose beers mainly by the taste and by the country of origin. Occasional consumers (Group 3) usually buy the same brands of beer, but use flavor and brand as a selection criterion. Finally, low-consumption consumers (Group 4) had a consumption of beer for special occasions. They often do not seek information about the product, and they do not do any kind of word-of-mouth marketing. The Main theoretical contribution is the new segmentation proposal method originated from the research. The relevance of this study is related to the new segmentation framework proposed segments that could be used to future studies in other competitive markets

    Ultralow loading electroless deposition of IrOx on nickel foam for efficient and stable water oxidation catalysis

    Get PDF
    Abstract Photocatalysis and electrolysis are crucial processes for the development of a sustainable, clean energy system, since they enable solar fuel production, such as hydrogen by water splitting, as well as CO2 reduction. In these processes efficient and robust catalysts for water oxidation are required and the reduction of employed amount of noble metals is crucial to reduce costs and increase the sustainability of the technology. To obtain extremely low iridium loading on nickel foam electrodes we have employed electroless deposition by spontaneous galvanic displacement as a simple, low cost, highly scalable technique. After deposition the Ir oxidation has been achieved by annealing in air at 250 °C. By varying the deposition parameters, an optimal condition has been achieved, with an overpotential for water oxidation of 360 mV at 10 mA cm−2 in 1.0 M KOH solution. The Ni foam coverage with Ir oxide has also a positive impact on the electrode stability, strongly decreasing the degradation rate, compared to the case of bare Ni foam. The average amount of noble metal in the best performing electrode is only 35 μg cm−2 for a 1.6 mm thick Ni foam electrode. The proposed approach is highly promising for gas diffusion electrodes, and can be implemented in electrolytic cells, as well as in fuel cells

    Biodegradation and metabolic pathway of the neonicotinoid insecticide thiamethoxam by Labrys portucalensis F11

    Get PDF
    Thiamethoxam (TMX) is an effective neonicotinoid insecticide. However, its widespread use is detrimental to non-targeted organisms and water systems. This study investigates the biodegradation of this insecticide by Labrys portucalensis F11. After 30 days of incubation in mineral salt medium, L. portucalensis F11 was able to remove 41%, 35% and 100% of a supplied amount of TMX (10.8 mg L−1) provided as the sole carbon and nitrogen source, the sole carbon and sulfur source and as the sole carbon source, respectively. Periodic feeding with sodium acetate as the supplementary carbon source resulted in faster degradation of TMX (10.8 mg L−1); more than 90% was removed in 3 days. The detection and identification of biodegradation intermediates was performed by UPLC-QTOF/MS/MS. The chemical structure of 12 metabolites is proposed. Nitro reduction, oxadiazine ring cleavage and dechlorination are the main degradation pathways proposed. After biodegradation, toxicity was removed as indicated using Aliivibrio fischeri and by assessing the synthesis of an inducible β-galactosidase by an E. coli mutant (Toxi-Chromo test). L. portucalensis F11 was able to degrade TMX under different conditions and could be effective in bioremediation strategies.info:eu-repo/semantics/publishedVersio
    • …
    corecore