172 research outputs found

    Jaetun pedagogisen johtajuuden ja toimivan tiimityön keskeisiä tekijöitä ja yhtymäkohtia varhaiskasvatuksessa

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    Tiivistelmä. Tämä tutkielma tarkastelee jaettua pedagogista johtajuutta ja toimivaa tiimityötä varhaiskasvatuksessa. Jaettu pedagoginen johtajuus vaikuttaa lapsen kohtaamaan varhaiskasvatuksen laatuun sekä tiimin toimivuuteen ja työntekijöiden hyvinvointiin. Tämän tutkimuksen tavoitteena on selvittää jaetun pedagogisen johtajuuden ja toimivan tiimityön keskeisiä tekijöitä ja yhtymäkohtia suomalaisen varhaiskasvatuksen kontekstissa. Tutkimus suoritettiin kuvailevana kirjallisuuskatsauksena, tarkemmin narratiivisena yleiskatsauksena. Aineistona on käytetty aiheeseen liittyviä kirjoja, tutkimusartikkeleita, väitöskirjoja ja muita julkaisuja. Jaettua pedagogista johtajuutta ja toimivaa tiimityötä tarkastellessamme löysimme useita niitä yhdistäviä tekijöitä. Yhteisiä tekijöitä jaetussa pedagogisessa johtajuudessa ja toimivassa tiimityössä ovat vuorovaikutus, vastuun jakaminen, sitoutuminen yhteisiin arvoihin ja toimintatapoihin sekä tiimin jaettu oppiminen ja pedagogiikan kehittäminen. Varhaiskasvatuksen opettajan rooli tiiminsä pedagogisena johtajana ja tiimijohtajana korostui tutkimustuloksissa. Lisäksi tuloksissamme painottui johtajan rooli tiimin tukijana sekä jaetun pedagogisen johtajuuden ja toimivan tiimityön mahdollistajana toimivia rakenteita luomalla. Jaettua pedagogista johtajuutta tiimityössä pitäisi tutkia enemmän, sillä suoraan siihen kohdistuneita tutkimuksia on niukasti. Myös tiimityöhön pitäisi kohdistaa enemmän tutkimusta, sillä vaikka tiimityö on tunnistettu merkittäväksi tekijäksi varhaiskasvatuksen kontekstissa sitä ei ole tutkittu tarpeeksi. Tutkielmamme tuottaa uutta tietoa jaetun pedagogisen johtajuuden ja toimivan tiimityön yhtymäkohdista sekä nostaa esiin molempien merkitystä varhaiskasvatuksen kontekstissa. Tutkimuksemme välittää tietoa käytännön työhön jaetun pedagogisen johtajuuden ja toimivan tiimityön keskeisistä tekijöistä, jotta varhaiskasvatushenkilöstö voi työssään kiinnittää huomiota näiden tekijöiden arviointiin ja kehittämiseen

    Co-Al spinel-based nanoparticles synthesized by flame spray pyrolysis for glycerol conversion

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    The catalytic properties of Co-Al spinel nanoparticles prepared by liquid-feed flame spray pyrolysis (L-F FSP) were investigated in the glycerol conversion in gas phase in an atmosphere of hydrogen. Reduction at 1123 K of the as-synthesized spinel nanoparticles induced the formation a new phase containing metallic cobalt species. Although, the reducibility of cobalt oxides is greatly decreased due to interaction with aluminium species, this strong interaction may prevent the aggregation of Co particles under the harsh reduction conditions. X-ray photoelectron spectroscopy (XPS) of the reduced spinel nanoparticles at 1123 K revealed that the Co/Al atomic ratio has decreased to Co/Al = 0.11, which may indicate a redistribution of the aluminum and cobalt species at the surface of the sample submitted to the reduction in a flow of hydrogen at 1123 K. X-ray diffraction (XRD) and high resolution electron microscopy (HRTEM) also reinforced the formation of metallic cobalt species after reduction of cobalt from the spinel nanoparticles at 1123 K. The main products obtained from the conversion of glycerol in the gas phase were hydroxyacetone, pyruvaldehyde, lactic acid and lactide. FSP ensured uniform dispersion of the active metal on a support material

    Applicability of heat generation data in determining the degradation mechanisms of cylindrical li-ion batteries

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    The applicability of heat generation data obtained after cylindrical Li-ion cells discharging with a constant current was analyzed thoroughly to determine cell degradation mechanisms. Different commercial and noncommercial cylindrical Li-ion cells, wherein graphite was used for negative electrode creation, were considered in this study and the degradation mechanisms were analyzed during cycling and storage. The heat generation in the cylindrical cells was estimated using heat flux and temperature measurements of the cell surface. The results obtained using analysis of the heat generation data were compared with those obtained using differential voltage analysis. The use of the heat generation data was shown to improve the detection and separation of the degradation mechanisms in Li-ion batteries during cycling and storage. The differential curve, which is based on the heat generation data, was proposed to investigate the degradation mechanisms. Moreover, the effects of the C-rate current and temperature on the form of the proposed differential curve were evaluated

    Variation of Absorption Angstrom Exponent in Aerosols From Different Emission Sources

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    The absorption Angstrom exponent (AAE) describes the spectral dependence of light absorption by aerosols. AAE is typically used to differentiate between different aerosol types for example., black carbon, brown carbon, and dust particles. In this study, the variation of AAE was investigated mainly in fresh aerosol emissions from different fuel and combustion types, including emissions from ships, buses, coal-fired power plants, and residential wood burning. The results were assembled to provide a compendium of AAE values from different emission sources. A dual-spot aethalometer (AE33) was used in all measurements to obtain the light absorption coefficients at seven wavelengths (370-950 nm). AAE(470/950) varied greatly between the different emission sources, ranging from -0.2 +/- 0.7 to 3.0 +/- 0.8. The correlation between the AAE(470/950) and AAE(370-950) results was good (R-2 = 0.95) and the mean bias error between these was 0.02. In the ship engine exhaust emissions, the highest AAE(470/950) values (up to 2.0 +/- 0.1) were observed when high sulfur content heavy fuel oil was used, whereas low sulfur content fuels had the lowest AAE(470/950) (0.9-1.1). In the diesel bus exhaust emissions, AAE(470/950) increased in the order of acceleration (0.8 +/- 0.1), deceleration (1.1 +/- 0.1), and steady driving (1.2 +/- 0.1). In the coal-fired power plant emissions, the variation of AAE(470/950) was substantial (from -0.1 +/- 2.1 to 0.9 +/- 1.6) due to the differences in the fuels and flue gas cleaning conditions. Fresh wood-burning derived aerosols had AAE(470/950) from 1.1 +/- 0.1 (modern masonry heater) to 1.4 +/- 0.1 (pellet boiler), lower than typically associated with wood burning, while the burn cycle phase affected AAE variation.Peer reviewe

    Influence of wood species on toxicity of log-wood stove combustion aerosols: A parallel animal and air-liquid interface cell exposure study on spruce and pine smoke

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    Background Wood combustion emissions have been studied previously either by in vitro or in vivo models using collected particles, yet most studies have neglected gaseous compounds. Furthermore, a more accurate and holistic view of the toxicity of aerosols can be gained with parallel in vitro and in vivo studies using direct exposure methods. Moreover, modern exposure techniques such as air-liquid interface (ALI) exposures enable better assessment of the toxicity of the applied aerosols than, for example, the previous state-of-the-art submerged cell exposure techniques. Methods We used three different ALI exposure systems in parallel to study the toxicological effects of spruce and pine combustion emissions in human alveolar epithelial (A549) and murine macrophage (RAW264.7) cell lines. A whole-body mouse inhalation system was also used to expose C57BL/6 J mice to aerosol emissions. Moreover, gaseous and particulate fractions were studied separately in one of the cell exposure systems. After exposure, the cells and animals were measured for various parameters of cytotoxicity, inflammation, genotoxicity, transcriptome and proteome. Results We found that diluted (1:15) exposure pine combustion emissions (PM1 mass 7.7 ± 6.5 mg m− 3, 41 mg MJZahl^{Zahl}) contained, on average, more PM and polycyclic aromatic hydrocarbons (PAHs) than spruce (PM1 mass 4.3 ± 5.1 mg m− 3, 26 mg MJ− 1) emissions, which instead showed a higher concentration of inorganic metals in the emission aerosol. Both A549 cells and mice exposed to these emissions showed low levels of inflammation but significantly increased genotoxicity. Gaseous emission compounds produced similar genotoxicity and a higher inflammatory response than the corresponding complete combustion emission in A549 cells. Systems biology approaches supported the findings, but we detected differing responses between in vivo and in vitro experiments. Conclusions Comprehensive in vitro and in vivo exposure studies with emission characterization and systems biology approaches revealed further information on the effects of combustion aerosol toxicity than could be achieved with either method alone. Interestingly, in vitro and in vivo exposures showed the opposite order of the highest DNA damage. In vitro measurements also indicated that the gaseous fraction of emission aerosols may be more important in causing adverse toxicological effects. Combustion aerosols of different wood species result in mild but aerosol specific in vitro and in vivo effects

    Particulate matter from both heavy fuel oil and diesel fuel shipping emissions show strong biological effects on human lung cells at realistic and comparable in vitro exposure conditions

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    Background: Ship engine emissions are important with regard to lung and cardiovascular diseases especially in coastal regions worldwide. Known cellular responses to combustion particles include oxidative stress and inflammatory signalling. Objectives: To provide a molecular link between the chemical and physical characteristics of ship emission particles and the cellular responses they elicit and to identify potentially harmful fractions in shipping emission aerosols. Methods: Through an air-liquid interface exposure system, we exposed human lung cells under realistic in vitro conditions to exhaust fumes from a ship engine running on either common heavy fuel oil (HFO) or cleaner-burning diesel fuel (DF). Advanced chemical analyses of the exhaust aerosols were combined with transcriptional, proteomic and metabolomic profiling including isotope labelling methods to characterise the lung cell responses. Results: The HFO emissions contained high concentrations of toxic compounds such as metals and polycyclic aromatic hydrocarbon, and were higher in particle mass. These compounds were lower in DF emissions, which in turn had higher concentrations of elemental carbon (“soot”). Common cellular reactions included cellular stress responses and endocytosis. Reactions to HFO emissions were dominated by oxidative stress and inflammatory responses, whereas DF emissions induced generally a broader biological response than HFO emissions and affected essential cellular pathways such as energy metabolism, protein synthesis, and chromatin modification. Conclusions: Despite a lower content of known toxic compounds, combustion particles from the clean shipping fuel DF influenced several essential pathways of lung cell metabolism more strongly than particles from the unrefined fuel HFO. This might be attributable to a higher soot content in DF. Thus the role of diesel soot, which is a known carcinogen in acute air pollution-induced health effects should be further investigated. For the use of HFO and DF we recommend a reduction of carbonaceous soot in the ship emissions by implementation of filtration devices

    Photocatalytic Decomposition of Formic Acid on Mo2C-Containing Catalyst

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    Soluble components in the peripheral blood from experimental exposure of 14 healthy subjects to filtered air and wood smoke. Samples were collected before (pre), at 24 h and 44 h after exposure, to air and wood smoke. Data are given as medians with interquartile range. (DOCX 62 kb
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