290 research outputs found

    and A.Bourmistrova

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    This paper present a methodology to achieve three dimensional shape optimization of damping liners attached to vibrating panels. It is the initial stage of the development of a flexible CAE design tool to optimize such liners in automotive panels. Noise, vibration and harshness are critical aspects in modern vehicle refinement and passenger perception of quality. Vibration from engine, powertrain and road sources are transmitted through the vehicle structure and excite body panels that add to the tactile vibrations felt by passengers and the noise level. To reduce this, damping materials are commonly attached to panels as uniform layers to absorb and dissipate vibration energy. A redistribution of damping material based on the dynamic response characteristics of the panels constitutes a more efficien

    A Psychometric Evaluation of the BEST in CLASS Adherence and Competence Scale

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    It is critical to utilize treatment integrity instruments to support the evaluation of evidence-based programs in early classroom contexts. However, in the early childhood field, guidelines for collecting treatment integrity data are underdeveloped. Consequently, most treatment integrity instruments employed in the field solely assess adherence, vary in design features and have little psychometric evidence supporting their use. As such, this represents a gap in the field that might slow efforts to implement evidence-based programs. The current study examines the score reliability and validity of an observational treatment integrity instrument (The BEST in CLASS Adherence and Competence Scale [BiCACS]; Sutherland et al., 2014). The BiCACS is designed to assess adherence and competence of the practices found in the BEST in CLASS program, a teacher-delivered evidence-based program for children at-risk for emotional and behavioral disorders. Data were drawn from observations of 179 teachers who were randomized to BEST in CLASS (n = 89) or business-as-usual (n = 90) and 416 children (n = 211 in the BEST in CLASS condition; n = 205 in the business-as-usual condition) at risk for emotional and behavioral disorders. Based on double-coded observations (25% of sample) the mean single-measure intraclass correlation (ICC[2,1]) was .74 (SD = 0.06) for the Adherence items and .46 (SD = 0.14) for the Competence items. The ICC(2,1) for the Adherence and Competence subscales were .81 and .43, respectively. Findings also suggested initial evidence of convergent and discriminant validity at the BiCACS item and subscale levels. The magnitude of correlations among the BiCACS items suggests that the adherence and Competence items overlap the most with items within the same subscale, but also measure distinct BEST in CLASS practices. At the subscale level, the correlation among the Adherence and Competence items are more related to each other than their correlations with scores on measures of child responsiveness, child engagement, closeness, and conflict of student-teacher relationships. Validity evidence at the subscale level suggests that the BiCACS can distinguish between intervention groups and detect change over time. The reliability and validity findings support the use of the BiCACS as a program evaluation instrument. Although, future research is still needed to replicate these findings and test the construct validity of the BiCACS with other instruments that assess adherence and competence. Still, results provide valuable information about the psychometric properties of a treatment integrity instrument used in early classroom contexts and inform the growing knowledge of this area in the field

    The relationship between successional vascular plant assemblages and associated microbial communities on coal mine spoil heaps

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    The aim of the study was to investigate the relationships between the vascular plant species and the associated soil microbial properties at various stages of vegetation development on unclaimed hard coal mine spoil heaps in Upper Silesia (south Poland). The spontaneous vegetation, soil chemistry as well as the activity and structure of microbial communities were recorded on this specific habitat. The colliery heaps were divided into four age classes and the plant species composition and cover abundance were recorded on established plots (2 m × 2 m). The soil microbial activity under the vegetation patches was assessed using fluorescein diacetate hydrolytic activity (FDHA) and the soil microbial biomass and community composition were determined by phospholipid fatty acid (PLFA) biomarkers. Total microbial biomass in soils from the older vegetation plots was significantly higher than those in soils from the younger plots. In all studied samples, microbial communities consisted primarily of bacteria with the dominance of Gram negative bacteria over Gram positive and aerobic microorganisms were more dominant than anaerobic ones. Statistical analysis revealed a correlation between the type of vegetation and microbial community structure

    Adult Hyalomma marginatum tick positive for Rickettsia aeschlimannii in Austria, October 2018

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    We report on a non-indigenous adult Hyalomma marginatum tick in Austria carrying the human pathogenic Rickettsia aeschlimannii; presumably introduced as a nymph via migratory birds and completed the moulting within the same year. It was negative for Crimean-Congo haemorrhagic fever virus, but the finding of R. aeschlimannii represents a potential threat for humans due to its zoonotic character. Awareness of invasive tick species and carried pathogens should be improved in central and northern Europe

    SAWA experiment ? properties of mineral dust aerosol as seen by synergic lidar and sun-photometer measurements

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    International audienceWe propose a method of retrieving basic information on mineral dust aerosol particles from synergic sun-photometer and multi-wavelength lidar measurements as well as from the observations of lidar light depolarisation. We use this method in a case study of mineral dust episode in Central Europe. Lidar signals are inversed with a modified Klett-Fernald algorithm. Aerosol optical depth measured with the sun-photometer allows to reduce uncertainties in the inversion procedure through which we estimate vertical profile of aerosol extinction. Next we assume that aerosol particles may be represented by ensemble of randomly oriented, identical spheroids. Having calculated vertical profiles of aerosol extinction coefficients for lidar wavelengths, we compute the profiles of local Angstrom exponent. We use laser beam depolarisation together with the calculated Angstrom exponents to estimate the shapes (aspect ratios) and sizes of the spheroids. Numerical calculations are performed with the transition matrix (T-matrix) algorithm by M. Mishchenko. The proposed method was first used during SAWA measurement campaign in Warsaw, spring 2005, to characterise the particles of desert dust, drifting over Poland with a southern-eastern wind (13?14 April). Observations and T-matrix calculations show that mode radii of spheroids representative for desert aerosols' particles are in the range of 0.15?0.3 ?m, while their aspect ratios are lower than 0.7 or larger than 1.7

    Energy-dispersive x-ray fluorescence analysis of modern coloured glasses from Marinha Grande (Portugal)

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    X-Ray Spectrom. 2003; 32: 396–401The elemental composition (K, Ca, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Sr, Ba, Nd and Pb) of modern coloured glasses was obtained by energy-dispersive x-ray fluorescence (EDXRF) spectrometry. This nondestructive technique is frequently used in the analysis of historical glass objects. Two reference glasses were also measured to assess the overall accuracy of the EDXRF method. Reference and unknown glasses were analysed without any preparation. The coloured glass samples studied belong to the Glass Museum of Marinha Grande and were chosen from two distinct collections, which were characterized by the different concentrations of some elements (K, Ti, Cr, Mn, Fe, Ba and Pb). The determined major elements allowed the identification of two raw materials used in glass manufacture, sand and lime. Multivariate statistical analysis, namely principal component extraction, simplified the identification of some of the colouring chemical elements, associating them with the different colours of the glass objects

    Microscopic description of the surface dipole plasmon in large Na_N clusters (950 < N < 12050)

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    Fully microscopic RPA/LDA calculations of the dipole plasmon for very large neutral and charged sodium clusters, Na_N^Z+, in the size range 950 < N < 12050 are presented for the first time. 60 different sizes are considered altogether, which allows for an in-depth investigation of the asymptotic behavior of both the width and the position of the plasmon.Comment: Latex/Revtex, 4 pages with 4 Postscript figures, accepted for publication in Physical Review

    Variability in black carbon mass concentration in surface snow at Svalbard

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    Black carbon (BC) is a significant forcing agent in the Arctic, but substantial uncertainty remains to quantify its climate effects due to the complexity of the different mechanisms involved, in particular related to processes in the snowpack after deposition. In this study, we provide detailed and unique information on the evolution and variability in BC content in the upper surface snow layer during the spring period in Svalbard (Ny-Ålesund). A total of two different snow-sampling strategies were adopted during spring 2014 (from 1 April to 24 June) and during a specific period in 2015 (28 April to 1 May), providing the refractory BC (rBC) mass concentration variability on a seasonal variability with a daily resolution (hereafter seasonal/daily) and daily variability with an hourly sampling resolution (hereafter daily/hourly) timescales. The present work aims to identify which atmospheric variables could interact with and modify the mass concentration of BC in the upper snowpack, which is the snow layer where BC particles affects the snow albedo. Atmospheric, meteorological and snow-related physico-chemical parameters were considered in a multiple linear regression model to identify the factors that could explain the variations in BC mass concentrations during the observation period. Precipitation events were the main drivers of the BC variability during the seasonal experiment; however, in the high-resolution sampling, a negative association has been found. Snow metamorphism and the activation of local sources (Ny-Ålesund was a coal mine settlement) during the snowmelt periods appeared to play a non-negligible role. The statistical analysis suggests that the BC content in the snow is not directly associated to the atmospheric BC load

    ACE-ASIA - Regional climatic and atmospheric chemical effects of Asian dust and pollution

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    Although continental-scale plumes of Asian dust and pollution reduce the amount of solar radiation reaching the earth's surface and perturb the chemistry of the atmosphere, our ability to quantify these effects has been limited by a lack of critical observations, particularly of layers above the surface. Comprehensive surface, airborne, shipboard, and satellite measurements of Asian aerosol chemical composition, size, optical properties, and radiative impacts were performed during the Asian Pacific Regional Aerosol Characterization Experiment (ACE-Asia) study. Measurements within a massive Chinese dust storm at numerous widely spaced sampling locations revealed the highly complex structure of the atmosphere, in which layers of dust, urban pollution, and biomass-burning smoke may be transported long distances as distinct entities or mixed together. The data allow a first-time assessment of the regional climatic and atmospheric chemical effects of a continental-scale mixture of dust and pollution. Our results show that radiative flux reductions during such episodes are sufficient to cause regional climate change
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