4,237 research outputs found

    Evaluation of the effects of space environment exposure on index of refraction and extinction coefficients of Apollo window materials

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    Temperature and radiation effects on index of refraction and extinction coefficients of Apollo window material

    Sustainable utilization of lime kiln dust as active filler in hot mix asphalt with moisture damage resistance

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    The Australian flexible road pavement network is experiencing a considerable degree of reveling and stripping damage in association with moisture. The next generation of hot mix asphalt (HMA) mixtures in Australia needs to have excellent engineering properties as well as higher resistance to moisture damage. Hydrated lime (HL) with a relatively high content of active lime is used in HMA mixtures to improve engineering properties, and particularly to enhance the resistance of HMA mixture to moisture. HL is currently considered a superior mineral filler to crushed rock baghouse dust but it is commercially produced and relatively expensive. Lime kiln dust (LKD) is an industrial by-product which has hydrated lime HMA filler-like properties with similar fineness and a relatively high content of active lime. The lime components in LKD assists in promoting resistance to the stripping common in siliceous acidic aggregates. This project aims to determine an optimum proportion of LKD in an LKD-asphalt binder mixture, based on the properties of viscoelasticity and aggregate adhesion. Dynamic shear rheometer testing and rolling bottle tests were used to evaluate the properties of the LKD-asphalt binder mixtures with varying LKD content. The test results indicated that a 50% LKD content in the LKD-HMA binder mixture provided superior viscoelasticity properties., an acceptable adhesion of asphalt to aggregates was also observed. Last but not the least, a ‘cradle to gate’ life cycle assessment was carried out to capture the benefits of the use of LKD by-product. This showed that GHG emissions and embodied energy demand could potentially be reduced by 18.5% and 2.4%, respectively if a 50% LKD asphalt binder by mass mixture was used in the LKD-HMA mix

    Refusal of Medical Fees at Ass. Offices.

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    Human somatic mutation assays as biomarkers of carcinogenesis.

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    This paper describes four assays that detect somatic gene mutations in humans: the hypoxanthine-guanine phosphoribosyl transferase assay, the glycophorin A assay, the HLA-A assay, and the sickle cell hemoglobin assay. Somatic gene mutation can be considered a biomarker of carcinogenesis, and assays for somatic mutation may assist epidemiologists in studies that attempt to identify factors associated with increased risks of cancer. Practical aspects of the use of these assays are discussed

    Literacy practices of primary education children in Andalusia (Spain): a family-based perspective

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    Primary school children develop literacy practices in various domains and situations in everyday life. This study focused on the analysis of literacy practices of children aged 8–12 years from the perspec- tive of their families. 1,843 families participated in the non-experimental explanatory study. The children in these families speak Spanish as a first language and are schooled in this language. The instrument used was a self-report questionnaire about children’s home-literacy practices. The data obtained were analysed using categorical principal components analysis (CATPCA) and analysis of variance (ANOVA). The results show the complex relationship between literacy practices developed by children in the domains of home and school and the limited development of a literacy-promoting ‘third space’. In conclusion, the families in our study had limited awareness of their role as literacy- promoting agents and thought of literacy learning as restricted to formal or academic spaces

    Electro-Oxidation of Titanium Carbide Nanoparticles in Aqueous Acid Creates TiC@TiO2 Core-Shell Structures

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    Titanium carbide (TiC) is an attractive support material used in electro-catalysis and sensing. We report the electrochemistry of TiC nanoparticles (NPs, 35–50 nm in diameter) in different electrolytes in the pH range of 0 to 8. The TiC NPs undergo irreversible oxidation in acidic, basic, and neutral media, attributed to the partial conversion into titanium dioxide (TiO2) with the amount of oxidation highly dependent on the pH of the solution. In H2SO4 (pH 0), multiple voltammetric scans revealed the conversion to be partial but repeated scans allowed a conversion approaching 100% to be obtained with 20 scans generating a ca 60% level of oxidation. The process is inferred to lead to the formation of TiC@TiO2 core-shell nanoparticles (~12.5 nm core radius and ~5 nm shell width for a 60% conversion) and this value sharply decreases with an increase of pH. Independent measurements were conducted at a single NP level (via nano-impact experiments) to confirm the oxidation of the NPs, showing consistent agreement with the bulk measurements

    Factor Analysis of the Milwaukee Inventory for Subtypes of Trichotillomania-Adult Version

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    The Milwaukee Inventory for Subtypes of Trichotillomania-Adult Version (MIST-A; Flessner et al., 2008) measures the degree to which hair pulling in Trichotillomania (TTM) can be described as “automatic” (i.e., done without awareness and unrelated to affective states) and/or “focused” (i.e., done with awareness and to regulate affective states). Despite preliminary evidence in support of the psychometric properties of the MIST-A, emerging research suggests the original factor structure may not optimally capture TTM phenomenology. Using data from a treatment-seeking TTM sample, the current study examined the factor structure of the MIST-A via exploratory factor analysis. The resulting two factor solution suggested the MIST-A consists of a 5-item “awareness of pulling” factor that measures the degree to which pulling is done with awareness and an 8-item “internal-regulated pulling” factor that measures the degree to which pulling is done to regulate internal stimuli (e.g., emotions, cognitions, and urges). Correlational analyses provided preliminary evidence for the validity of these derived factors. Findings from this study challenge the notions of “automatic” and “focused” pulling styles and suggest that researchers should continue to explore TTM subtypes
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