Phosphorus solubility in basaltic glass: limitations for phosphorus immobilization in glass and glass-ceramics

The composition of sewage sludge from urban wastewater treatment plants is simulated using P-doped basalts. Electron microscopy analyses show that the solubility of P in the basaltic melt is limited by the formation of a liquid-liquid immiscibility in the form of an aluminosilicate phase and a Ca-Mg-Fe-rich phosphate phase. The rheological behavior of these compositions is influenced by both phase separation and nanocrystallization. Upon a thermal treatment, the glasses will crystallize into a mixture of inosilicates and spinel-like phases at low P contents and into Ca-Mg-Fe phosphate at high P contents. Hardness measurements yield values between 5.41 and 7.66 GPa, inside the range of commercial glasses and glass-ceramics. Leaching affects mainly unstable Mg2+-PO43- complexes

Private and public modes of bicycle commuting: a perspective on attitude and perception

BACKGROUND: Public bicycle-sharing initiatives can act as health enhancement strategies among urban populations. The aim of the study was to determine which attitudes and perceptions of behavioural control toward cycling and a bicycle-sharing system distinguish commuters with a different adherence to bicycle commuting. METHODS: The recruitment process was conducted in 40 random points in Barcelona from 2011 to 2012. Subjects completed a telephone-based questionnaire including 27 attitude and perception statements. Based on their most common one-way commute trip and willingness to commute by bicycle, subjects were classified into Private Bicycle (PB), public bicycle or Bicing Bicycle (BB), Willing Non-bicycle (WN) and Non-willing Non-bicycle (NN) commuters. After reducing the survey statements through principal component analysis, a multinomial logistic regression model was obtained to evaluate associations between attitudinal and commuter sub-groups. RESULTS: We included 814 adults in the analysis [51.6% female, mean (SD): age 36.6 (10.3) years]. BB commuters were 2.0 times [95% confidence interval (CI) = 1.1-3.7] less likely to perceive bicycle as a quick, flexible and enjoyable mode compared to PB. BB, WN and NN were 2.5 (95% CI = 1.46-4.24), 2.6 (95% CI = 1.53-4.41) and 2.3 times (95% CI = 1.30-4.10) more likely to perceive benefits of using public bicycles (bicycle maintenance and parking avoidance, low cost and no worries about theft and vandalism) than did PB. CONCLUSION: Willing non-bicycle and public-bicycle commuters had more favourable perception toward public-shared bicycles compared to private cyclists. Hence, public bicycles may be the impetus for those willing to start bicycle commuting, thereby increasing physical activity levels

Potential of tungsten tailings as glass raw materials

Glasses from different types of tungsten mine tailings were obtained and studied to determine their ability to be used as raw materials of commercial glass. Tailings of granitic composition from Barruecopardo, of calc-silicate wastes from Morille, and of schists and quartz from Panasqueira, were used as raw materials. The addition of CaCO3 and NaCO3 was necessary for the manufacture of the glass. Samples were characterised by XRF, XRD, HSM and DTA-TG. Furthermore, the expansion coefficient, Vickers microhardness and leaching properties were measured. The results show that all the tungsten mine tailings used were suitable for the manufacture of commercial glass, with the addition of calcium and soda. The calc-silicate tailing needs less additive content to produce a glass. Also, they present lower workability temperatures and higher durability. Glasses obtained from all the tested tailings retain the potentially toxic elements in their structure and prevents the environmental pollution.</p

Physical performance and physical activity in older adults: associated but separate domains of physical function in old age.

Background: Physical Function Is A Crucial Factor In The Prevention And Treatment Of Health Conditions In Older Adults And Is Usually Measured Objectively With Physical Performance Tests And/or Physical Activity Monitoring. Objective: To Examine Whether 1) Physical Performance (PP) And Physical Activity (PA) Constitute Separate Domains Of Physical Function; 2) Differentiation Of PA Classes Is More Informative Than Overall PA. Design: Cross-Sectional Study To Explore The Relationships Within And Among PP And PA Measures. Methods In 49 Older Participants (83±7 Years; M±SD), Performance-based Tests Were Conducted And PA Was Measured For One Week. Activity Monitor Data Were Reduced In Terms Of Duration, Periods, And Mean Duration Of Periods Of Lying, Sitting, Standing And Locomotion. The Relation Between And Within PP Scores And PA Outcomes Were Analysed Using Rank Order Correlation And Factor Analysis. Results: Factor Structure After Varimax Rotation Revealed Two Orthogonal Factors Explaining 78% Of The Variance In The Data: One Comprising All PA Variables And One Comprising All PP Variables. PP Scores Correlated Moderately With PA In Daily Life. Differentiation Of Activity Types And Quantification Of Their Duration, Intensity And Frequency Of Occurrence Provided Stronger Associations With PP, As Compared To A Single Measure Of Acceleration Expressing Overall PA. Limitations: For Independent Validation, The Conclusions About The Validity Of The Presented Conceptual Framework And Its Clinical Implications Need To Be Confirmed In Other Studies. Conclusions: PP And PA Represent Associated But Separate Domains Of Physical Function, Suggesting That An Improvement Of PP Does Not Automatically Imply An Increase Of PA, I.e. A Change To A More Active Lifestyle. Differentiation Of Activity Classes In The Analysis Of PA Provides More Insights Into PA And Its Association With PP Than Using A Single Overall Measure Of Acceleration

Recycling of tailings from the Barruecopardo tungsten deposit for the production of glass

Tailings from tungsten mining activities in the vicinity of Barruecopardo (Salamanca) represent high environmental pollution. In this paper we present a study of the use of these wastes as raw materials for the manufacture of glass. This procedure aims to contribute to environmental remediation of mining areas through vitrification, a process which offers an alternative for stabilization of hazardous wastes. In addition, the marketing of the obtained product would provide an additional income to the mining areas. The chemical composition of the tailings to be used as raw materials was determined by X-ray fluorescence and their mineralogy by X-ray diffraction. Wastes are of granitic composition enriched in potentially toxic elements. For this study, a representative sample of mining wastes of sandy grain size was used to make the glass. On the basis of its composition, glass was formulated by adding 29.28 mass% of CaCO3 and 14.03 mass% of Na2CO3 and a green glass was produced. Crystallisation temperatures, obtained by DTA, were 875 and 1022 °C and the melting temperature was 1175 °C. The transition temperature of glass was of 644 °C. The temperatures for the fixed viscosity points, and the working temperatures were obtained. A thermal treatment induced devitrification to produce a glass-ceramic made of nepheline and wollastonite. Leaching tests of the obtained glass confirm its capacity to retain potentially toxic elements

Stratification of COPD patients by previous admission for targeting of preventative care

SummaryBackgroundHospital admissions for exacerbations of chronic obstructive pulmonary disease (COPD) impact considerably on disease evolution and healthcare provision. Building on previous studies, this study postulated that COPD patients could be stratified by risk of admission to determine which groups provide the greatest burden on resources, and how interventions should be targeted to prevent admissions.MethodsCOPD admissions during 1997–2003 in three Strategic Health Authorities in England were analysed (n=80,291). Patients admitted during winter (1 November–31 March) were stratified into three groups according to the number of admissions during the previous year: 0 (NIL), 1–2 (MOD) or ≥3 (FRQ). Winter weeks were classified as “average”, “above average”, “high”, or “very high” risk, compared with the long-term mean.ResultsThe risk of admission during winter for FRQ and MOD patients was 40% and 12% respectively. NIL patients contributed to 70% of winter admissions, and 90% of the variation between “average” and “very high” weeks, versus 9% and 1% for MOD and FRQ.ConclusionsPatients with no previous admissions have lower individual risk, but contribute to a high overall utilisation of health care resources and should be targeted to prevent admissions. Focusing upon high-risk patients (frequent attenders or more severe) may only reduce a small proportion of admissions, and therefore clinicians should ensure that all COPD patients receive appropriate therapy to reduce risk of exacerbations

Validity of instruments to measure physical activity may be questionable due to a lack of conceptual frameworks: a systematic review

BACKGROUND: Regulators' guidance documents for the development and validation of patient reported outcomes (PROs) advise the use of conceptual frameworks, which outline the structure of the concept that a PRO aims to measure. It is unknown if currently available PROs are based on conceptual frameworks. This study, limited to a specific case, aimed (i) to identify conceptual frameworks of physical activity in chronic respiratory patients or similar populations (chronic heart disease patients or the elderly), and (ii) to assess if the development and validation of PROs to measure physical activity in these populations were based on a conceptual framework of physical activity. METHODS: Two systematic reviews were conducted through search in Medline, Embase, Psychinfo, and Cinahl databases up to January 2010. RESULTS: In the first review only 2 references, identified from 581 references about physical activity in the defined populations, provided a conceptual framework of physical activity in COPD patients. In the second review, out of 103 studies developing PROs to measure physical activity or related constructs, none of them was based on a conceptual framework of physical activity. CONCLUSIONS: These findings raise concerns about how the large body of evidence from studies that use physical activity PRO instruments should be evaluated by health care providers, guideline developers, and regulatory bodies