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Dry sliding wear tests were performed on a CW614 brass alloy coated with Ni-Cr layers using a pin-on-disk configuration. In order to characterize the surface durability and wear process of Ni-Cr electrodeposition, a parametric study was conducted to provide data on the friction coefficient, wear, and contact surface temperature within a load range of 10-25 N and sliding velocity ranging from 0.78 to 2.35 m/s. Two main wear modes have been observed: (i) micro-transfer phenomenon associated with delamination wear for mild loading conditions, and (ii) macro-transfer along with intensive plastic deformations and oxidative wear for severe loading conditions. The mild-to-severe wear mechanism transitions have been summarized in a wear-friction map. [ABSTRACT FROM AUTHOR]

This paper presents a new tribometer developed for a study of the tribological and the viscoelastic behaviour of seat materials used in ball valve. This device simulates the contact configuration and the loading conditions produced during service process (opening-closing valve). The originality of such tribometer lies in the possibility of coupling/decoupling the stress relaxation from the tribological behaviour that allows the evaluation of the interaction between tribology and viscoelastic behaviour. Besides, the tribometer concept and manufactured solution of the same subassemblies as well as the measure system and software for data acquisition and processing results are described. This paper also reports the results of a very first set of experiments conducted on polytetrafluoro ethylene materials under dry rolling conditions. The results obtained show a good correlation with the results found in literature, which encourages more investigation into seats ball valve. [ABSTRACT FROM AUTHOR]

Invasive candidiasis has emerged as an important nosocomial infection, causing significant morbidity and mortality especially among critically ill patients. The aim of our study was to determine specie distribution and resistance profiles of Candida species isolated from blood cultures. Materials and Methods: We conducted a retrospective study of all episodes of candidemia diagnosed in our laboratory from January 2006 to May 2009. The susceptibility to antifungal agents of all Candida isolates was tested by using a Sensititre YeastOne panel. Results: A total of 130 Candida isolates were recovered from blood cultures. Candida tropicalis was the most frequent specie (37.7%), followed by C. albicans (22.3%), C. glabrata (19.2%), and C. parapsilosis (12.2%). All the isolates were inhibited by ≤1 μg/ml of amphotericin B and ≤2 μg/ml of caspofungin. For fluconazole, 7.3% of clinical isolates were resistant. It was most active against C. parapsilosis (100% susceptible), C. albicans (95.8% susceptible), and C. tropicalis (94% susceptible). All of the fluconazole-susceptible isolates were susceptible to voriconazole, as were 83.3% of the fluconazole-susceptible-dose-dependent isolates. Among fluconazole-resistant isolates, 85.7% were susceptible to voriconazole. Conclusions: In our institution, C. tropicalis was the most frequent specie isolated from the bloodstream. Caspofungin had an excellent in vitro activity against Candida isolates and was the drug of choice among fluconazole-resistant isolates. [ABSTRACT FROM AUTHOR]