Direct rapid quality assurance analysis of complex matrix materials: A chemometrics enabled energy dispersive X-ray fluorescence and scattering spectrometry application.

Compared to energy dispersive X-ray fluorescence (EDXRF) that is limited to analysis of elements (Z ≥ 13) via fluorescence and which is hardly direct, energy dispersive X-ray fluorescence and scattering (EDXRFS) spectrometry exploits additionally, scatter radiation to quantify both low- and heavy-Z elements as well as predict various material properties. The goal of this work was to demonstrate proof-of-concept for chemometrics-enabled EDXRFS spectrometry utilizing a weak sample excitation source towards rapid quality assurance (QA) analysis of complex matrix materials. A109Cd source was used to analyse three types of polymer powders - polypropylene (PP), low density polyethene (LDPE) and high density polyethene (HDPE) moulded as âˆ¼ 2.5 g (∅ = 2.5 cm) pellets; and both actual as well as simulate lubricating oils spiked with trace additive metals B, Na, Ca, Mg, Fe and Zn and subjected to thermal degradation between 100 °C and 400 °C for 24 h. EDXRFS combined with principal components analysis (PCA) and soft independent modelling of class analogy (SIMCA) accurately identified polypropylene as well as differentiated it from both low density polyethene (LDPE) and high density polyethene (HDPE). LDPE and HDPE were fairly discriminated on the basis of density. In the second application partial least squares (PLS) modelling successfully determined the viscosity of lubricating oils utilizing the combination of the scatter peak and the Zn fluorescence signature, as well as correlated the lubricating oils viscosity to their thermal degradation. The reported method is applicable in industrial quality assurance due to its non-destructivity and speed.

Sex differentials in the uptake of antiretroviral treatment in Zambia.

This study explores socio-structural factors that influence uptake of antiretroviral treatment (ART) in Zambia and assess differences between men and women. We conducted a case-control study nested in a community- and health facility-based survey, between September 2010 and February 2011. Cases were defined as HIV-positive individuals who, while eligible, never started ART and controls were HIV-positive individuals who were on ART. Cases and controls were matched by place of residence. We performed a conditional logistic regression analysis using a discrete logistic model stratified by sex. Overall, a significantly larger proportion of men (32.7%) than women (25.6%) did not uptake ART (Pearson χ(2) = 5.9135; p = 0.015). In the crude analysis, poor health status and low self-efficacy were common factors associated with non-uptake in both sexes. After adjusting for covariates, men were more likely than women to refuse ART even though men's self-rated health was lower than women's. In general, the adjusted analysis suggests that HIV status disclosure affects uptake in both sexes but women's uptake of ART is largely hampered by poverty-related factors while for men, side effects and social pressure, probably associated with masculinity, are more important barriers. Alarmingly men's health seems to deteriorate until they start treatment, in contrast to women. Understanding gender differences in uptake and attitudes to ART is a crucial component to providing effective and appropriate health care to both men and women living with HIV/AIDS in Zambia.

Feasibility for direct rapid energy dispersive X-ray fluorescence (EDXRF) and scattering analysis of complex matrix liquids by partial least squares.

The greatest challenge to material characterization by XRF technique is encountered in direct trace analysis of complex matrices. We exploited partial least squares (PLS) in conjunction with energy dispersive X-ray fluorescence and scattering (EDXRFS) spectrometry to rapidly (200 s) analyze lubricating oils. The PLS-EDXRFS method affords non-invasive quality assurance (QA) analysis of complex matrix liquids as it gave optimistic results for both heavy- and low-Z metal additives. Scatter peaks may further be used for QA characterization via the light elements.

[Risk perception and representation in construction sites: a preliminary study]. / La percezione e rappresentazione del rischio nei cantieri edili: uno studio esplorativo.

The number of building injuries and professional health disease make evidence of safety problems in this field. The study of human factors may help us in observing this problem in a better way (more global). The aims of this study is to investigate construction workers risk perception and representation. Which are the risk? Which risk is perceived as more dangerous? What is Risk?. These are some question this study try to give an answer, asking about worker perception and representation of risk. Qualitative analysis shows which are the meanings workers use when they talk about risk, underlining the influence of personal, group, organizational and cultural variables.