660 research outputs found

    How\u27d You Like To Spoon With Me?

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    https://digitalcommons.library.umaine.edu/mmb-vp/1618/thumbnail.jp

    Direct reduction of pellets through hydrogen: Experimental and model behaviour

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    This paper presents the hydrogen reduction behaviour of industrial pellets designed for the efficient hydrogen based direct reduction. The pellets were provided with very low non ferrous oxides percentage (0.52 of basicity index) and with the absence on TiO2 oxides. The pellets measured diameters in the range 1.14–1.72 cm and were characterized in terms of porosity, pores size, tortuosity and compression strength. The pellets were reduced in hydrogen atmosphere in a laboratory shaft furnace in the temperature ranges of 600–1200 °C at the pressures of 1 and 5 bar. The pellets' reduction behaviour was analysed in terms of time to reduction, rate of reduction and kinetics constant. All the obtained results were analysed through the employment of a commercial multi-objective optimization tool (modeFrontier) in order to precisely define the effect of each single parameter on the pellets’ reduction. It was also defined the effect of the ongoing reduction rate of the final metallization of the starting iron oxides

    Seasonal hydrological and suspended sediment transport dynamics in proglacial streams, James Ross Island, Antarctica

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    Rapid warming of the Antarctic Peninsula is producing accelerated glacier mass loss and can be expected to have significant impacts on meltwater runoff regimes and proglacial fluvial activity. This study presents analysis of the hydrology and suspended sediment dynamics of two proglacial streams on James Ross Island, Antarctic Peninsula. Mean water discharge during 8 January 2015 to 18 February 2015 reached 0.19 m3 s−1 and 0.06 m3 s−1 for Bohemian Stream and Algal Stream, respectively, equivalent to specific runoff of 76 and 60 mm month−1. The daily discharge regime strongly correlated with air and ground temperatures. The effect of global radiation on proglacial water discharge was found low to negligible. Suspended sediment concentrations of Bohemian Stream were very high (up to 2927 mg L−1) due to aeolian supply and due to the high erodibility of local rocks. Total sediment yield (186 t km−2 yr−1) was high for (nearly) deglaciated catchments, but relatively low in comparison with streams draining more glaciated alpine and arctic catchments. The sediment provenance was mostly local Cretaceous marine and aeolian sediments; volcanic rocks are not an important source for suspended load. High Rb/Sr ratios for some samples suggested chemical weathering. Overall, this monitoring of proglacial hydrological and suspended sediment dynamics contributes to the dearth of such data from Antarctic environments and offers an insight to the nature of the proglacial fluvial activity, which is likely to be in a transient state with ongoing climate change

    Adolescent physical activity and screen time: associations with the physical home environment

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    <p>Abstract</p> <p>Background</p> <p>Previous research on the environment and physical activity has mostly focused on macro-scale environments, such as the neighborhood environment. There has been a paucity of research on the role of micro-scale and proximal environments, such as that of the home which may be particularly relevant for younger adolescents who have more limited independence and mobility. The purpose of this study was to describe associations between the home environment and adolescent physical activity, sedentary time, and screen time.</p> <p>Methods</p> <p>A total of 613 parent-adolescent dyads were included in these analyses from two ongoing cohort studies. Parents completed a Physical Activity and Media Inventory (PAMI) of their home environment. Adolescent participants (49% male, 14.5 ± 1.8 years) self-reported their participation in screen time behaviors and wore an ActiGraph accelerometer for one week to assess active and sedentary time.</p> <p>Results</p> <p>After adjusting for possible confounders, physical activity equipment density in the home was positively associated with accelerometer-measured physical activity (p < 0.01) among both males and females. Most of the PAMI-derived measures of screen media equipment in the home were positively associated with adolescent female's screen time behavior (p ≤ 0.03). In addition, the ratio of activity to media equipment was positively associated with physical activity (p = 0.04) in both males and females and negatively associated with screen time behavior for females (p < 0.01).</p> <p>Conclusions</p> <p>The home environment was associated with physical activity and screen time behavior in adolescents and differential environmental effects for males and females were observed. Additional research is warranted to more comprehensively assess the home environment and to identify obesogenic typologies of families so that early identification of at-risk families can lead to more informed, targeted intervention efforts.</p

    Sparsity and Incoherence in Compressive Sampling

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    We consider the problem of reconstructing a sparse signal x0Rnx^0\in\R^n from a limited number of linear measurements. Given mm randomly selected samples of Ux0U x^0, where UU is an orthonormal matrix, we show that 1\ell_1 minimization recovers x0x^0 exactly when the number of measurements exceeds mConstμ2(U)Slogn, m\geq \mathrm{Const}\cdot\mu^2(U)\cdot S\cdot\log n, where SS is the number of nonzero components in x0x^0, and μ\mu is the largest entry in UU properly normalized: μ(U)=nmaxk,jUk,j\mu(U) = \sqrt{n} \cdot \max_{k,j} |U_{k,j}|. The smaller μ\mu, the fewer samples needed. The result holds for ``most'' sparse signals x0x^0 supported on a fixed (but arbitrary) set TT. Given TT, if the sign of x0x^0 for each nonzero entry on TT and the observed values of Ux0Ux^0 are drawn at random, the signal is recovered with overwhelming probability. Moreover, there is a sense in which this is nearly optimal since any method succeeding with the same probability would require just about this many samples

    Development and initial validation of the bronchiectasis exacerbation and symptom tool (BEST)

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    BACKGROUND: Recurrent bronchiectasis exacerbations are related to deterioration of lung function, progression of the disease, impairment of quality of life, and to an increased mortality. Improved detection of exacerbations has been accomplished in chronic obstructive pulmonary disease through the use of patient completed diaries. These tools may enhance exacerbation reporting and identification. The aim of this study was to develop a novel symptom diary for bronchiectasis symptom burden and detection of exacerbations, named the BEST diary. METHODS: Prospective observational study of patients with bronchiectasis conducted at Ninewells Hospital, Dundee. We included patients with confirmed bronchiectasis by computed tomography, who were symptomatic and had at least 1 documented exacerbation of bronchiectasis in the previous 12\u2009months to participate. Symptoms were recorded daily in a diary incorporating cough, sputum volume, sputum colour, dyspnoea, fatigue and systemic disturbance scored from 0 to 26. RESULTS: Twenty-one patients were included in the study. We identified 29 reported (treated exacerbations) and 23 unreported (untreated) exacerbations over 6-month follow-up. The BEST diary score showed a good correlation with the established and validated questionnaires and measures of health status (COPD Assessment Test, r =\u20090.61, p =\u20090.0037, Leicester Cough Questionnaire, r =\u2009-\u20090.52,p =\u20090.0015, St Georges Respiratory Questionnaire, r =\u20090.61,p &lt;\u20090.0001 and 6\u2009min walk test, r =\u2009-\u20090.46,p =\u20090.037). The mean BEST score at baseline was 7.1 points (SD 2.2). The peak symptom score during exacerbation was a mean of 16.4 (3.1), and the change from baseline to exacerbation was a mean of 9.1 points (SD 2.5). Mean duration of exacerbations based on time for a return to baseline symptoms was 15.3\u2009days (SD 5.7). A minimum clinically important difference of 4 points is proposed. CONCLUSIONS: The BEST symptom diary has shown concurrent validity with current health questionnaires and is responsive at onset and recovery from exacerbation. The BEST diary may be useful to detect and characterise exacerbations in bronchiectasis clinical trials

    Iranian Herbalists, But Not Cooks, Are Better at Naming Odors Than Laypeople

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    Odor naming is enhanced in communities where communication about odors is a central part of daily life (e.g., wine experts, flavorists, and some hunter-gatherer groups). In this study, we investigated how expert knowledge and daily experience affect the ability to name odors in a group of experts that has not previously been investigated in this context—Iranian herbalists; also called attars—as well as cooks and laypeople. We assessed naming accuracy and consistency for 16 herb and spice odors, collected judgments of odor perception, and evaluated participants' odor meta-awareness. Participants' responses were overall more consistent and accurate for more frequent and familiar odors. Moreover, attars were more accurate than both cooks and laypeople at naming odors, although cooks did not perform significantly better than laypeople. Attars' perceptual ratings of odors and their overall odor meta-awareness suggest they are also more attuned to odors than the other two groups. To conclude, Iranian attars—but not cooks—are better odor namers than laypeople. They also have greater meta-awareness and differential perceptual responses to odors. These findings further highlight the critical role that expertise and type of experience have on olfactory functions

    Understanding young adult physical activity, alcohol and tobacco use in community colleges and 4-year post-secondary institutions: A cross-sectional analysis of epidemiological surveillance data

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    <p>Abstract</p> <p>Background</p> <p>Young adults experience many adverse health behavior changes as they transition from adolescence into adulthood. A better understanding of the relationships between health promoting and risky health behaviors may aid in the development of health promotion interventions for various types of young adult post-secondary students. Therefore, the purpose of this study was to examine associations between alcohol and tobacco use and physical activity among 2-year and 4-year college students.</p> <p>Methods</p> <p>Cross-sectional analyses were conducted using 2007 survey data, collected as part of an on-going post-secondary health surveillance system in Minnesota. Students were randomly selected to participant from 14 Minnesota colleges and universities (six 2-year community and/or technical colleges, eight 4-year post-secondary institutions). The 2007 surveillance data included 9,931 respondents.</p> <p>Results</p> <p>The prevalence of demographic characteristics and health behaviors (e.g., physical activity, tobacco use) differed between young adults attending 2-year and 4-year post-secondary institutions; in general, those attending 2-year institutions are representative of more at-risk populations. Overall, higher levels of moderate, vigorous and strengthening physical activity were associated with higher levels of alcohol consumption and lower levels of smoking. In general, despite the disparities in the prevalence of these risk behaviors, the associations between the behaviors did not differ substantially between 2-year and 4-year post-secondary populations.</p> <p>Conclusions</p> <p>These findings illustrate links between leading risk behaviors. Interventions targeting multiple risk behaviors among young adults may warrant further consideration. Overall, future research is needed to support and inform young adult health promotion efforts that may be implemented in a wide array of post-secondary institutions.</p
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