Microstructure assessment of suspension plasma spraying coatings from multicomponent submicronic Y-TZP/Al2O3/SiC particles

In this research, Suspension Plasma Spraying (SPS) technique was used for the thermal deposition of a multicomponent mixture made up of an Y-TZP/Al₂O₃ matrix with SiC particles. Two suspensions of Y-TZP and Al₂O₃ with different SiC particles content (6?wt% and 12?wt%) were tested as feedstocks in the SPS process. Three stand-off distances were varied in order to assess coating microstructure and evaluate the presence of SiC in the final coatings. Coatings were characterised in terms of porosity, microstructure and phase distribution. The estimate of the amount of SiC in the coating was carried out by XRD technique.Findings showed typical cauliflower-like SPS microstructure which intensifies with stand-off distance. Coatings porosity varied significantly between 8% and 25% whereas minimum porosity was found for the intermedium stand-off distance of 40?mm.Microstructure analysis also revealed the presence of SiC particles in the coatings which was confirmed by EDX analysis, overall XRD tests as well as TG analysis. Finally, evaluation of SiC content in the final coatings by means of XRD analysis showed that most of SiC particles (c.a 80%) of the feedstocks were preserved in the final coatings.     

Molecular Epidemiology of Enteroaggregative Escherichia coli (EAEC) Isolates of Hospitalized Children from Bolivia Reveal High Heterogeneity and Multidrug-Resistance

Enteroaggregative Escherichia coli (EAEC) is an emerging pathogen frequently associated with acute diarrhea in children and travelers to endemic regions. EAEC was found the most prevalent bacterial diarrheal pathogen from hospitalized Bolivian children less than five years of age with acute diarrhea from 2007 to 2010. Here, we further characterized the epidemiology of EAEC infection, virulence genes, and antimicrobial susceptibility of EAEC isolated from 414 diarrheal and 74 non-diarrheal cases. EAEC isolates were collected and subjected to a PCR-based virulence gene screening of seven virulence genes and a phenotypic resistance test to nine different antimicrobials. Our results showed that atypical EAEC (a-EAEC, AggR-negative) was significantly associated with diarrhea (OR, 1.62, 95% CI, 1.25 to 2.09, p < 0.001) in contrast to typical EAEC (t-EAEC, AggR-positive). EAEC infection was most prevalent among children between 7–12 months of age. The number of cases exhibited a biannual cycle with a major peak during the transition from warm to cold (April–June). Both typical and a-EAEC infections were graded as equally severe; however, t-EAEC harbored more virulence genes. aap, irp2 and pic were the most prevalent genes. Surprisingly, we detected 60% and 52.6% of multidrug resistance (MDR) EAEC among diarrheal and non-diarrheal cases. Resistance to ampicillin, sulfonamides, and tetracyclines was most common, being the corresponding antibiotics, the ones that are frequently used in Bolivia. Our work is the first study that provides comprehensive information on the high heterogenicity of virulence genes in t-EAEC and a- EAEC and the large prevalence of MDR EAEC in Bolivia.     

Synthesis,characterization and rheological properties of multiblock associative copolymers by RAFT technique

Polymer Bulletin - Preparation of associating multiblock copolymer electrolytes mediated by radical addition–fragmentation chain transfer (RAFT) technique has been evaluated and reported in...     

Explanations for over-constrained problems using QuickXPlain with speculative executions

Conflict detection is used in various scenarios ranging from interactive decision making (e.g., knowledge-based configuration) to the diagnosis of potentially faulty models (e.g., using knowledge base analysis operations). Conflicts can be regarded as sets of restrictions (constraints) causing an inconsistency. Junker’s QuickXPlain is a divide-and-conquer based algorithm for the detection of preferred minimal conflicts. In this article, we present a novel approach to the detection of such conflicts which is based on speculative programming. We introduce a parallelization of QuickXPlain and empirically evaluate this approach on the basis of synthesized knowledge bases representing feature models. The results of this evaluation show significant performance improvements in the parallelized QuickXPlain version.

     

Study on the influence of maintenance operations on energy consumption and emissions in healthcare centres by fuzzy cognitive maps

The present work is aimed at performing a qualitative analysis of the effect of maintenance intensity on energy consumption, energy costs and emissions in healthcare centres. Most relevant variables involved in the maximization of the building efficiency were determined by means of fuzzy cognitive maps. Twelve variables were observed to show a direct connection to the energy and environmental efficiency as well as to its maintenance condition. The joint effect of these factors was seen to improve the overall performance of the building in terms of efficiency. However, even though maintenance appeared as one of the most highly-rated variables, it did not seem to affect the overall performance by itself, but it was rather due to the synergistic action of the remaining variables. The behaviour of those variables was evidenced to show a significant change for buildings below 1250?m² floor area as compared to those exceeding such threshold value.     

GC–MS Characterization of Volatile Compounds in Habanero Pepper (Capsicum chinense Jacq.) by Optimization of Headspace Solid-Phase Microextraction Conditions

Food Analytical Methods - The habanero pepper (Capsicum chinense Jacq.) is very aromatic and is the hottest pepper in the world. In this study, a headspace solid-phase microextraction/gas...     

Key factors that influence the UX of a dual-player game for the cognitive stimulation and motor rehabilitation of older adults

Universal Access in the Information Society - In this work, the results of usability and user experience (UX) evaluation of a serious video game for the cognitive stimulation and motor...