Microbial Fuel Cell Application for Azoic Dye Decolorization with Simultaneous Bioenergy Production Using Stenotrophomonas sp.

A single‐chamber air‐cathode microbial fuel cell (MFC) was successfully applied for decolorization of the diazoic dye Reactive Black 5 (RB5) with simultaneous production of electricity. An innovative low‐cost medium, the marine water‐glucose‐yeast extract medium (MWGY), was developed which appears as a textile marine effluent in terms of salinity. The anode compartment containing a single bacterial strain of Stenotrophomonas sp. showed almost complete dye decolorization with different RB5 concentrations after seven days of treatment. For the four dye concentrations used, a correlation between dye removal and production of electrical energy was found. The comparison of the decolorization process in the MFC with that in a batch reactor as control experiment highlights the efficiency of the single‐chamber air‐cathode MFC technology which improved the dye removal by the same bacterial strain.     

Pistacia lentiscus extract as a green inhibitor for copper corrosion in 0.5 M of H2SO4: electrochemical characterization and theoretical investigations

Journal of Applied Electrochemistry - The current work aims to study the effect of Pistacia lentiscus (Pil) essential oil originating from Chefchaouen city, which is located in northeastern Morocco...     

Effect of vibroimpact treatment on the physical and mechanical properties of the surface layer of welded joints in rails

The formation of the hardened layer on the surface of the welded joint in the railhead by the method of vibroimpact hardening in an electromagnetic impact action machine is discussed. The procedure and results of investigations of the effect of vibroimpact hardening on the physical and mechanical properties of the welded joints in rails are described.     

Inter-comparative study of quantitative methods of industrial clinker

Impurities from the raw materials, the grinding and the homogenization of the raw materials, the kiln instability and the complexity of the cooling step, all these factors make it difficult to obtain a perfect evaluation of the mineralogical composition of Portland clinker. We studied the limitations of the most commonly used quantitative methods and recommend some procedures to obtain reliable and reproducible results of quantitative analyses. Different clinker samples (provided by the Bizerte Cement Company (Tunisia)) were subjected to an elemental analysis by X-ray fluorescence and the mineralogical composition was determined by the Bogue calculation and by X-ray powder diffraction combined with the Rietveld method (Different softwares were used: XPert High Score Plus version 2.0 and TOPAS version 4.2). We then compared the results obtained by the Rietveld method and the Bogue calculation to the specific peak areas of each phase. The content of each phase, determined by the Rietveld method, varied proportionally to the change in peak area; a significant difference in these results was found by using the elementary Bogue calculation.     

Discarded needles do not increase soon after the opening of a needle exchange program

This study examines the effect of a Needle Exchange Program (NEP) on the quantity and geographic distribution of discarded needles on the streets of Baltimore, Maryland, and presents methods to survey discarded needles in the community. A random sample of 32 city blocks located within high-drug-use census tracts, stratified by east and west sides of the city and by proximity to the NEP, was selected for survey. Three teams surveyed the number of needles and the number of drug vials and unbroken glass bottles ("trash") to control for practice effects. Surveillance was conducted prior to initiation of the NEP in August 1994 and 1 and 2 months thereafter. Over the three study periods, the absolute count of discarded needles was 106, 130, and 128, respectively; the number of vials and bottles was 3,048, 3,825, and 3,796, respectively. The initial nonstatistically significant increase in needles (mean change = 0.38, 95% confidence interval (CI) -0.18 to 0.93) was offset by accounting for background trash. Regression models fitted with the generalized estimating equation method, which accounted for within-block correlation over time, showed no significant increase in the number of needles after adjustment for trash during the first 2 months of the NEP's operation. These data suggest that the initiation of NEPs does not result in an increase in the number of discarded needles on the street.     

Tracking of markers and onset of disease among HIV-1 seroconverters

Repeated measurements on persons infected with HIV-1 indicate that infection has a dynamic impact on several markers of immune suppression and activation. The objectives of this report are: (a) to provide a statistical model for the correlation structure of serial measurements of immunological markers, and (b) to identify features of marker profiles associated with the timing of AIDS diagnoses. We analyse data obtained from 328 seroconverters participating in the Multicenter AIDS Cohort Study on whom the date of HIV-1 seroconversion is known within +/- 4.5 months. Immunological markers considered here are CD4 cell counts, serum beta 2-microglobulin and serum neopterin. The statistical model for HIV-related changes in markers consists of (1) a piecewise linear regression model for the trajectories of markers over time and (2) a two-parameter autocorrelation function that generalizes Markovian and simple random effects autocorrelation structures. Application of this model for marker measurements revealed a high degree of tracking, as the estimated autocorrelation function exhibited sub-exponential decay over time. Though current marker levels are most informative on future values, there is substantial information (memory) in previous measurements. A feature suggested by the analysis of groups formed according to the length of the AIDS-free period, is the sequential divergence of the CD4 trajectories where steeper declines occurred with a two-year lag prior to AIDS onset. For AIDS cases diagnosed 3-5 and 5-7 years after seroconversion, the rates of decline compared with those free of AIDS for at least 4 years were steeper by 95 and 46 per cent respectively at two years prior to AIDS.     

A national study of postoperative mortality associated with coronary artery bypass grafting in Israel. ISCAB Consortium. Israel Coronary Artery Bypass Study

BACKGROUND: Investigation of observed differences in outcomes among medical centers is of major interest to the medical community and the public and has a substantial impact on efforts to improve the quality of medical care. METHODS: This study analyzed data from consecutive patients who underwent isolated coronary artery bypass grafting at 14 medical centers. Data included demographic and clinical information, comorbidity, cardiac catheterization results, and 30-day postoperative vitality status. Logistic regression analysis was used to identify variables associated with mortality. An outlier hospital was defined as one having an observed mortality outside the 95% confidence interval boundaries around the expected mortality rate calculated, given the patient risk factors. RESULTS: The overall crude 30-day mortality rate for isolated coronary artery bypass grafting among the 4,835 patients in this study was 3.1%. The rate varied among centers, ranging from 0.85% to 7.05%. Predictors of 30-day mortality included advanced age, female sex, diabetes mellitus, poor left ventricular function, high creatinine level, high priority of operation, and three-vessel disease (with or without left main coronary artery disease). After adjustment for risk factors, two hospitals were defined as outliers. CONCLUSIONS: The observed disparity in early mortality among patients undergoing coronary artery bypass grafting is not due solely to differences in case mix.