555 resultados para swd: Imam-bara
Resumo:
Vegetation changes, such as shrub encroachment and wetland expansion, have been observed in many Arctic tundra regions. These changes feed back to permafrost and climate. Permafrost can be protected by soil shading through vegetation as it reduces the amount of solar energy available for thawing. Regional climate can be affected by a reduction in surface albedo as more energy is available for atmospheric and soil heating. Here, we compared the shortwave radiation budget of two common Arctic tundra vegetation types dominated by dwarf shrubs (Betula nana) and wet sedges (Eriophorum angustifolium) in North-East Siberia. We measured time series of the shortwave and longwave radiation budget above the canopy and transmitted radiation below the canopy. Additionally, we quantified soil temperature and heat flux as well as active layer thickness. The mean growing season albedo of dwarf shrubs was 0.15 ± 0.01, for sedges it was higher (0.17 ± 0.02). Dwarf shrub transmittance was 0.36 ± 0.07 on average, and sedge transmittance was 0.28 ± 0.08. The standing dead leaves contributed strongly to the soil shading of wet sedges. Despite a lower albedo and less soil shading, the soil below dwarf shrubs conducted less heat resulting in a 17 cm shallower active layer as compared to sedges. This result was supported by additional, spatially distributed measurements of both vegetation types. Clouds were a major influencing factor for albedo and transmittance, particularly in sedge vegetation. Cloud cover reduced the albedo by 0.01 in dwarf shrubs and by 0.03 in sedges, while transmittance was increased by 0.08 and 0.10 in dwarf shrubs and sedges, respectively. Our results suggest that the observed deeper active layer below wet sedges is not primarily a result of the summer canopy radiation budget. Soil properties, such as soil albedo, moisture, and thermal conductivity, may be more influential, at least in our comparison between dwarf shrub vegetation on relatively dry patches and sedge vegetation with higher soil moisture.
Resumo:
In 2001, a weather and climate monitoring network was established along the temperature and aridity gradient between the sub-humid Moroccan High Atlas Mountains and the former end lake of the Middle Drâa in a pre-Saharan environment. The highest Automated Weather Stations (AWS) was installed just below the M'Goun summit at 3850 m, the lowest station Lac Iriki was at 450 m. This network of 13 AWS stations was funded and maintained by the German IMPETUS (BMBF Grant 01LW06001A, North Rhine-Westphalia Grant 313-21200200) project and since 2011 five stations were further maintained by the GERMAN DFG Fennec project (FI 786/3-1), this way some stations of the AWS network provided data for almost 12 years from 2001-2012. Standard meteorological variables such as temperature, humidity, and wind were measured at an altitude of 2 m above ground. Other meteorological variables comprise precipitation, station pressure, solar irradiance, soil temperature at different depths and for high mountain station snow water equivalent. The stations produced data summaries for 5-minute-precipitation-data, 10- or 15-minute-data and a daily summary of all other variables. This network is a unique resource of multi-year weather data in the remote semi-arid to arid mountain region of the Saharan flank of the Atlas Mountains. The network is described in Schulz et al. (2010) and its further continuation until 2012 is briefly discussed in Redl et al. (2015, doi:10.1175/MWR-D-15-0223.1) and Redl et al. (2016, doi:10.1002/2015JD024443).
Resumo:
Observations of snow properties, superimposed ice, and atmospheric heat fluxes have been performed on first-year and second-year sea ice in the western Weddell Sea, Antarctica. Snow in this region is particular as it does usually survive summer ablation. Measurements were performed during Ice Station Polarstern (ISPOL), a 5-week drift station of the German icebreaker RV Polarstern. Net heat flux to the snowpack was 8 W/m**2, causing only 0.1 to 0.2 m of thinning of both snow cover types, thinner first-year and thicker second-year snow. Snow thinning was dominated by compaction and evaporation, whereas melt was of minor importance and occurred only internally at or close to the surface. Characteristic differences between snow on first-year and second-year ice were found in snow thickness, temperature, and stratigraphy. Snow on second-year ice was thicker, colder, denser, and more layered than on first-year ice. Metamorphism and ablation, and thus mass balance, were similar between both regimes, because they depend more on surface heat fluxes and less on underground properties. Ice freeboard was mostly negative, but flooding occurred mainly on first-year ice. Snow and ice interface temperature did not reach the melting point during the observation period. Nevertheless, formation of discontinuous superimposed ice was observed. Color tracer experiments suggest considerable meltwater percolation within the snow, despite below-melting temperatures of lower layers. Strong meridional gradients of snow and sea-ice properties were found in this region. They suggest similar gradients in atmospheric and oceanographic conditions and implicate their importance for melt processes and the location of the summer ice edge.
Resumo:
Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.
Resumo:
This study is a first attempt to unravel the almost unexplored domain of abstract conceptual knowledge. Four kinds of abstract concepts (nominal kinds, states of the self, cognitive processes, and emotion concepts) were investigated in two experiments. Emotion concepts displayed a specific pattern in both concreteness/abstractness and imagery ratings (cf. Altarriba et al., 1999), as did the other considered domains of abstract knowledge (Experiment 1). In Experiment 2 we highlighted the specific pattern of information (taxonomic, thematic, attributive, etc) these different abstract domains elicited in a definition production task.
Resumo:
Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.
Resumo:
Samoylov Island is centrally located within the Lena River Delta at 72° N, 126° E and lies within the Siberian zone of continuous permafrost. The landscape on Samoylov Island consists mainly of late Holocene river terraces with polygonal tundra, ponds and lakes, and an active floodplain. The island has been the focus of numerous multidisciplinary studies since 1993, which have focused on climate, land cover, ecology, hydrology, permafrost and limnology. This paper aims to provide a framework for future studies by describing the characteristics of the island's meteorological parameters (temperature, radiation and snow cover), soil temperature, and soil moisture. The land surface characteristics have been described using high resolution aerial images in combination with data from ground-based observations. Of note is that deeper permafrost temperatures have increased between 0.3 to 1.3 °C over the last five years. However, no clear warming of air and active layer temperatures is detected since 1998, though winter air temperatures during recent years have not been as cold as in earlier years.
Resumo:
We present the first ecosystem-scale methane flux data from a northern Siberian tundra ecosystem covering the entire snow-free period from spring thaw until initial freeze-back. Eddy covariance measurements of methane emission were carried out from the beginning of June until the end of September in the southern central part of the Lena River Delta (72°22' N, 126°30' E). The study site is located in the zone of continuous permafrost and is characterized by Arctic continental climate with very low precipitation and a mean annual temperature of -14.7°C. We found relatively low fluxes of on average 18.7 mg/m**2/d, which we consider to be because of (1) extremely cold permafrost, (2) substrate limitation of the methanogenic archaea, and (3) a relatively high surface coverage of noninundated, moderately moist areas. Near-surface turbulence as measured by the eddy covariance system in 4 m above the ground surface was identified as the most important control on ecosystem-scale methane emission and explained about 60% of the variance in emissions, while soil temperature explained only 8%. In addition, atmospheric pressure was found to significantly improve an exponential model based on turbulence and soil temperature. Ebullition from waterlogged areas triggered by decreasing atmospheric pressure and near-surface turbulence is thought to be an important pathway that warrants more attention in future studies. The close coupling of methane fluxes and atmospheric parameters demonstrated here raises questions regarding the reliability of enclosure-based measurements, which inherently exclude these parameters.
Resumo:
Currently, there is increasing use of nanomaterials in the food industry thanks to the many advantages offered and make the products that contain them more competitive in the market. Their physicochemical properties often differ from those of bulk materials, which require specialized risk assessment. This should cover the risks to the health of workers and consumers as well as possible environmental risks. The risk assessment methods must go updating due to more widespread use of nanomaterials, especially now that are making their way down to consumer products. Today there is no specific legislation for nanomaterials, but there are several european dispositions and regulations that include them. This review gives an overview of the risk assessment and the existing current legislation regarding the use of nanotechnology in the food industry.
Resumo:
Las relaciones entre los gabinetes de Comunicación de los clubes de fútbol y los periodistas deportivos se enmarcan en el modelo de Gieber y Johnson (1961) por el que el hecho de que ambos compartan objetivos comunes, donde los gabinetes de Comunicación necesitan que los medios publiquen determinadas informaciones y los periodistas precisan de noticias que publicar, provoca una pérdida de independencia por parte de los periodistas, ya que necesitan a esos departamentos como fuentes. En la actualidad, los departamentos de Comunicación de los clubes de fútbol, como el del FC Barcelona, se han constituido en gatekeepers. Esto ha acentuado las históricas diferencias que existen entre los periodistas y los profesionales de la comunicación corporativa, incrementado por el control informativo de estos departamentos lo que provoca constantes tensiones entre ambos.
Resumo:
La consolidación del fútbol en España se produjo a partir de los años veinte del siglo pasado. Entre 1920 a 1936 el fútbol adquirió todos los rasgos personales que hoy le caracterizan. En esta época surgió una literatura técnica y periodística especializada que se configuró como uno de los pilares más importantes para el desarrollo técnico deportivo y del espectáculo de masas. En torno a esta cuestión, el presente artículo busca un doble objetivo: recopilar la literatura técnica y periodística especializada publicada durante el período de 1920 a 1936, y reconocer el alcance social, técnico e ideológico de esta literatura futbolística en el proceso de configuración del fútbol en España. Para abordar este propósito hemos utilizado una metodología heurística y de análisis documental de las fuentes originales. Apreciamos que a través de estas obras podemos conocer mejor el contexto del espacio socio-deportivo del fútbol en España y, también, despertar nuevas líneas potenciales de investigación.
Resumo:
In recent years, depth cameras have been widely utilized in camera tracking for augmented and mixed reality. Many of the studies focus on the methods that generate the reference model simultaneously with the tracking and allow operation in unprepared environments. However, methods that rely on predefined CAD models have their advantages. In such methods, the measurement errors are not accumulated to the model, they are tolerant to inaccurate initialization, and the tracking is always performed directly in reference model's coordinate system. In this paper, we present a method for tracking a depth camera with existing CAD models and the Iterative Closest Point (ICP) algorithm. In our approach, we render the CAD model using the latest pose estimate and construct a point cloud from the corresponding depth map. We construct another point cloud from currently captured depth frame, and find the incremental change in the camera pose by aligning the point clouds. We utilize a GPGPU-based implementation of the ICP which efficiently uses all the depth data in the process. The method runs in real-time, it is robust for outliers, and it does not require any preprocessing of the CAD models. We evaluated the approach using the Kinect depth sensor, and compared the results to a 2D edge-based method, to a depth-based SLAM method, and to the ground truth. The results show that the approach is more stable compared to the edge-based method and it suffers less from drift compared to the depth-based SLAM.
Resumo:
Bakgrund: Kroniska sår innefattas av bensår, fotsår, trycksår, diabetessår, sårskada, tumörer, reumatiska sår och vårdskador vid komplikationer efter kirurgiska ingrepp, som inte har läkt inom 6 veckor. Forskning visar att trots att förebyggande strategier används, utvecklas det sår som kräver behandling. I mötet med vården är en god omvårdnad och en god vårdrelation viktig. Bristen på dessa leder ofta till ett lidande som individen måste kämpa emot med copingstrategier. Syfte: Syftet med denna litteraturstudie var att belysa personers erfarenhet av att leva med kroniska sår. Metod: En litteraturöversikt gjordes i denna studie med 15 vetenskapliga artiklar, som bestod av både kvantitativ och kvalitativ metod. Resultat: 3 huvudkategorier identifierades: begränsningar, lidande samt coping. Deltagarna ansåg att en brist på information samt begränsningar i vardagen påverkade individens sociala umgänge och fysiska aktivitet. Smärta, skam och rädsla ledde till depression. För att hantera detta använde individerna sig av familjen och stöd av vårdpersonalen Slutsats: Det framkom att individernas dagliga liv påverkades av det kroniska såret. Den konstanta smärtan orsakade sömnsvårigheter hos individen, vilket ytterligare försvårade hanteringen av smärtan och vardagen. Kontinuitet hos vårdpersonal och i behandlingen gav personerna en trygghet och en ökad förståelse för sitt tillstånd. Det belystes att det var viktigt att vårdpersonalen ser individen bakom såret, och inte bara lägger sitt fokus på sårläkningen och behandlingen.
Resumo:
In previous studies research has shown that generation y experience resistance from older generations represented in the labor market in USA. The resistance is due to differences between the generations. On the other hand some studies say that differences are more likely to come from other factors such as gender and which stage in life the individual is in. The purpose of this study is to describe how (women in) generation y is experiencing the cooperation with colleagues from other generations and if they considers that differences due to generations exist. The study will also try to determine if the respondents are aware of each generation’s characteristics. To fulfill the purpose of the study a qualitative method was chosen in the shape of a focus group. To be able to answer the purpose an interview guide was developed from previous studies. The guide was divided in three sections; scenarios, exercises and finally questions. The focus group resulted in a two-hour discussion between four individuals belonging to generation y. The result of the study showed that generation y in Falun, Sweden did identify some of the characteristics each generation had. Further did the respondents conform that resistance due to generational differences was a problem. To answer the purpose of the study generation y felt underestimated by the older generations and expressed a certain degree of hopelessness.