842 resultados para Diffusion of innovations
Resumo:
El municipio es considerado como un espacio donde sus habitantes comparten no sólo el territorio sino también los problemas y los recursos existentes. La institución municipal -como gobierno local- es el ámbito en el cual se toman decisiones sobre el territorio, que implican a sus habitantes. En cuanto a los actores, estos pueden ser funcionarios, empleados y la comunidad (individual y organizada en ongs), todos aportan sus conocimientos y valores, pero tienen diferentes intereses y diferentes tiempos. Vinculada a las decisiones, encontramos que la forma en que se gestiona la información territorial, es determinante si se pretende apuntar hacia acciones con impacto positivo, y sustentables en lo ambiental y en el tiempo. Este trabajo toma tres municipios: San Salvador de Jujuy, capital de la provincia localizada en los Valles Templados; San Pedro de Jujuy, principal municipio de la región de las Yungas y Tilcara en la Quebrada de Humahuaca. El aporte de la Inteligencia Territorial, a través del observatorio OIDTe, permite analizar los modos de gestión de la información, especialmente mediante el uso de las tecnologías de la información y comunicación (pagina web municipal, equipamiento informático en las oficinas, estrategias de comunicación y vinculación con la población) y mediante la organización de las estructuras administrativas (organigrama) por las cuales circula la información municipal. Además, con la participación enriquecedora de equipos multidisciplinarios en las diferentes etapas. Se busca, a partir de un diagnóstico, generar estrategias para la introducción de innovaciones con los propios actores municipales, a partir de las situaciones y modos culturales propios de cada lugar, incorporando los marcos conceptuales de la Inteligencia Territorial. En este sentido el OIDTe al promover el entendimiento entre los actores, institucionales y la sociedad, facilita la coordinación de diferentes intereses propiciando la toma de decisiones por acuerdos. Asimismo, el método Portulano, puede orientar la introducción de innovaciones en la coordinación de la información cartográfica, para que las diferentes oficinas puedan complementar sus aportes y la comunicación hacia fuera de la institución. En la fase de diagnóstico, se aplicaron entrevistas a informantes claves, se realizó un workshop con técnicos de planta permanente y funcionarios de áreas que manejan información territorial, y de planificación. También por la importancia de la capacidad instalada de recursos humanos, se analizó el nivel de instrucción y la capacitación con que cuenta el personal de planta permanente de cada área
Resumo:
El municipio es considerado como un espacio donde sus habitantes comparten no sólo el territorio sino también los problemas y los recursos existentes. La institución municipal -como gobierno local- es el ámbito en el cual se toman decisiones sobre el territorio, que implican a sus habitantes. En cuanto a los actores, estos pueden ser funcionarios, empleados y la comunidad (individual y organizada en ongs), todos aportan sus conocimientos y valores, pero tienen diferentes intereses y diferentes tiempos. Vinculada a las decisiones, encontramos que la forma en que se gestiona la información territorial, es determinante si se pretende apuntar hacia acciones con impacto positivo, y sustentables en lo ambiental y en el tiempo. Este trabajo toma tres municipios: San Salvador de Jujuy, capital de la provincia localizada en los Valles Templados; San Pedro de Jujuy, principal municipio de la región de las Yungas y Tilcara en la Quebrada de Humahuaca. El aporte de la Inteligencia Territorial, a través del observatorio OIDTe, permite analizar los modos de gestión de la información, especialmente mediante el uso de las tecnologías de la información y comunicación (pagina web municipal, equipamiento informático en las oficinas, estrategias de comunicación y vinculación con la población) y mediante la organización de las estructuras administrativas (organigrama) por las cuales circula la información municipal. Además, con la participación enriquecedora de equipos multidisciplinarios en las diferentes etapas. Se busca, a partir de un diagnóstico, generar estrategias para la introducción de innovaciones con los propios actores municipales, a partir de las situaciones y modos culturales propios de cada lugar, incorporando los marcos conceptuales de la Inteligencia Territorial. En este sentido el OIDTe al promover el entendimiento entre los actores, institucionales y la sociedad, facilita la coordinación de diferentes intereses propiciando la toma de decisiones por acuerdos. Asimismo, el método Portulano, puede orientar la introducción de innovaciones en la coordinación de la información cartográfica, para que las diferentes oficinas puedan complementar sus aportes y la comunicación hacia fuera de la institución. En la fase de diagnóstico, se aplicaron entrevistas a informantes claves, se realizó un workshop con técnicos de planta permanente y funcionarios de áreas que manejan información territorial, y de planificación. También por la importancia de la capacidad instalada de recursos humanos, se analizó el nivel de instrucción y la capacitación con que cuenta el personal de planta permanente de cada área
Resumo:
Este estudio tiene como primer objetivo conocer el volumen y evolución de la producción científica española en psicología a partir de las bases de datos del Web of Science (Thomson Reuters) y Scopus (Elsevier), durante el periodo 2000-2009. A partir de allí, se propone determinar cuáles son las revistas científicas más utilizadas por los psicólogos españoles para difundir sus trabajos a nivel internacional y comparar la cobertura y solapamiento de revistas y documentos que presentan ambas bases de datos. Se ofrecen datos cuantitativos, se estudia la posible correlación entre las dos bases de datos y se analiza el solapamiento de documentos y de revistas, el modelo de crecimiento que presentan y la dispersión de los trabajos, entre otros. Los resultados muestran que ambos sistemas de información son complementarios pero no excluyentes, así como la relevancia e importancia de las revistas españolas de psicología en la difusión de la investigación de esta disciplina en el contexto internacional de la ciencia
Resumo:
The effects of desiccation on photochemical processes and nitrogenase activity were evaluated in Nostoc commune s.l. colonies in situ from a wet thufur meadow at Petuniabukta, Billefjorden, Central Svalbard, during the 2009 arctic summer. The colonies were collected in the fully hydrated state, and were subjected to slow desiccation at ambient temperatures (5 - 8°C) and low light (30 - 80 µmol/m**2/s). For each colony the weight, area, photochemical performance, and nitrogenase activity were determined at the beginning, as well as on every day during the first four days of the experiment; thereafter, on every second day until desiccation was complete. The photochemical performance was evaluated from variable chlorophyll fluorescence parameters (FV/FM, Phi(PSII) , qP, and NPQ), and the nitrogenase activity was estimated by an acetylene-ethylene reduction assay. A significant decrease in the photochemically active area was recorded from the third day, when the colony had lost approximately 40% of its original weight indicating some changes in the extracellular matrix, and stopped on the 14th to 18th day. No effects of the desiccation on the main photochemical parameters (FV/FM, Phi(PSII), qP) were observed up to the sixth to eighth days of desiccation. Slightly lower values of FV/FM and Phi(PSII) recorded in fully-hydrated colonies could be caused by impaired diffusion of CO2 into cells. The steep reduction of photochemical activity occurred between the eighth and tenth day of the experiment, when the colony had lost approximately 80% of its fully-hydrated weight. The nitrogenase activity was highest on the first day, probably due to improved diffusion of N2 into cells, then declined, but was detectable until the sixth day of the experiment. Since Nostoc commune s.l. colonies were capable of photosynthesis and nitrogen fixation to the level of ca. 60% of its fully-hydrated weight, even partly-hydrated colonies contribute substantially to carbon and nitrogen cycling in the High Arctic wet meadow tundra ecosystem.
Resumo:
Different generations of complex authigenic carbonates formed in siliceous muds (lithologic Unit IV) and hemipelagic clays (lithologic Unit V) of ODP Site 643, Leg 104 Norwegian Sea. The dominant phase in Unit IV is an early diagenetic Mn, Fe-calcite with a strong negative d13C ( -14 to -16 per mil) signature, and slightly negative d180 values. The strong negative d13C results from extensive incorporation of 12C-enriched CO2 derived from bacterial degradation of marine organic matter into early Mn, Fe - calcite cements. Concomitant framboidal pyrite precipitation and abundant SEM microtextures showing excellent preservation of delicate structures of fragile diatom valves by outpourings with early Mn-calcites strongly support their shallow burial formation before the onset of compaction. Later generations of authigenic mineralizations in lithologic Unit IV include minor amounts of a second generation of calcite with platy crystals, possibly precipitated along with opal-A dissolution, and finally opal-CT crystallization in deeper seated environments overgrowing earlier precipitates with films and lepispheres. The last mineralization is collophane (fluor apatite) forming amorphous aggregates and tiny hexagonal crystals. Authigenic mineral assemblages in lithologic Unit V consist of rhodochrosites, transitional rhodochrosite/manganosiderites, and apatite. A negative d13C ( -7.1 to -15.6 per mil) and a fluctuating d18O signal indicates that the micritic to sparitic rhodochrosites, transitional rhodochrosites/manganosiderites were formed at various burial depths. CO2 resulted from organic matter degradation in the lowermost sulfate reduction zone and from biogenic methane generation in the lowermost sediments, resulting in variable and negative d13C signals. The change in carbonate mineralogy reflects major compositional differences compared to sediments in Unit IV. Most prominent is an increase in altered ash as a primary sediment component and a sudden decrease of siliceous microfossils. Upward diffusion of cations, lowered salinities in pore waters, and elevated temperatures provide diagenetic environments favoring increased remobilization processes.
Resumo:
A shallow gas depth-contour map covering the Skagerrak-western Baltic Sea region has been constructed using a relatively dense grid of existing shallow seismic lines. The digital map is stored as an ESRI shape file in order to facilitate comparison with other data from the region. Free gas usually occurs in mud and sandy mud but is observed only when sediment thickness exceeds a certain threshold value, depending on the water depth of the area in question. Gassy sediments exist at all water depths from approx. 20 m in the coastal waters of the Kattegat to 360 m in the Skagerrak. In spite of the large difference in water depths, the depth of free gas below seabed varies only little within the region, indicating a relatively fast movement of methane in the gas phase towards the seabed compared to the rate of diffusion of dissolved methane. Seeps of old microbial methane occur in the northern Kattegat where a relatively thin cover of sandy sediments exists over shallow, glacially deformed Pleistocene marine sediments. Previous estimates of total methane escape from the area may be correct but the extrapolation of local methane seepage rate data to much larger areas on the continental shelf is probably not justified. Preliminary data on porewater chemistry were compared with the free gas depth contours in the Aarhus Bay area, which occasionally suffers from oxygen deficiency, in order to examine if acoustic gas mapping may be used for monitoring the condition of the bay.
Resumo:
The barium distribution in sediments and pore fluids from five sites drilled in the Japan Sea have been used to illustrate the geochemical behavior of this element as it pertains paleoproductivity reconstructions, diagenetic remobilization, and barite precipitation in authigenic fronts. Sites where sulfate is depleted in the pore fluids also show high concentrations of dissolved barium, reflecting dissolution of biogenic barite. The high rate of sedimentation at Sites 798 and 799 results in a rapid sulfate depletion, which in turn leads to barite dissolution and reprecipitation in diagenetic fronts. The dissolved barium distribution at these sites has been used to quantify the rate of barite dissolution; we estimate a first-order rate constant for barite dissolution to be 2*10**-6/s at Site 799 and 2*10**-7/s at Site 798. Authigenic barite has been documented in sediments from Site 799 at 323 meters below seafloor by scanning electron microscopy and X-ray fluorescence analysis. These results indicate barite precipitation in a diagenetic front near the zone of sulfate depletion by upward migration of dissolved barium and downward diffusion of sulfate. Barite precipitation has also been inferred at Sites 796 and 798 based on sedimentary and dissolved barium distributions. Sulfate is not depleted in the pore fluids of Site 794. The lack of diagenetic remobilization of biogenic barium at this site preserves the high barium signal associated with the high-productivity sequences deposited during the late Miocene to Pliocene. Significantly, the organic carbon distribution does not indicate high accumulation rates during the periods of high opal and barium deposition. Instead, higher organic carbon accumulations are recorded in the Quaternary and middle Miocene sequences; intervals that are also characterized by deposition of siliciclastic turbidites. The presence of a terrestrial component in the organic carbon record renders barium a more useful indicator than organic carbon for paleoproductivity reconstructions in this marginal sea.
Resumo:
A large deposit of ferromanganese oxide coated sands and scattered manganese nodules occurs in the northern portion of Lake Ontario. The Mn and Fe contents of the concretions are similar to those in concretions from other environments, while their Ni, Cu, and Co contents are lower than in deep-sea nodules, but higher than in most previously described lacustrine concretions. Pb and Zn are high in the coatings and exceed the concentrations found in many previously analyzed Mn deposits. Within the deposit, Mn, Ni, Co, and Zn contents are correlated, and they vary inversely with Fe. Mn, Fe, Ni, Cu, and Pb are present in the interstitial waters of the sediments underlying the deposit in higher concentrations than in the overlying lake waters, thus providing a potential source of metals for concretion formation.The origin and compositional variations in the deposit possibly can be explained in terms of the fractionation and precipitation of Fe and Mn as a result of redox variations in the lake sediments. Eh increases from south to north across the deposit in such a way that iron may be selectively oxidized and precipitated in the south and manganese, in the north. The upward diffusion of Mn, Fe, and associated elements from the underlying sediments probably provides the principal source of the metals in the south of the deposit, while metal-enriched bottom waters are probably the principal source in the north.
Resumo:
In an attempt to establish criteria for obtaining reliable K-Ar dates, conventional K-Ar studies of several Deep Sea Drilling Project sites were undertaken. K-Ar dates of these rocks may be subject to inaccuracies as the result of sea-water alteration. Inaccuracies may also result from the presence of excess radiogenic 40Ar trapped in rapidly cooled rocks at the time of their formation. The results obtained for DSDP Leg 34 basalts indicate that lowering of K-Ar dates, which is related to potassium addition by weathering, is a major cause of uncertainty in obtaining reliable K-Ar dates for deep-sea rocks. It could not be determined if the potassium addition to the basalts occurred at the time of formation, t_o, or continuously from t_o to the present. Calculations show that sediment cover is not a significant barrier to the diffusion of potassium into the basalt. 40Ar loss contributes, at least in part, to the lowering of the K-Ar date in rocks that have added potassium. The meaning of the K-Ar results obtained for DSDP Legs 35 and 2 basalts could not be unambiguously established. Because of the problems involved, caution must be used in interpreting the meaning of conventional K-Ar dates for deep-sea rocks.
Resumo:
Porous seep-carbonates are exposed at mud volcanoes in the eastern Mediterranean Sea. The 13C-depleted aragonitic carbonates formed as a consequence of the anaerobic oxidation of methane in a shallow sub-surface environment. Besides the macroscopically visible cavernous fabric, extensive carbonate corrosion was revealed by detailed analysis. After erosion of the background sediments, the carbonates became exposed to oxygenated bottom waters that are periodically influenced by the release of methane and upward diffusion of hydrogen sulphide. We suggest that carbonate corrosion resulted from acidity locally produced by aerobic oxidation of methane and hydrogen sulphide in the otherwise, with respect to aragonite, oversaturated bottom waters. Although it remains to be tested whether the mechanisms of carbonate dissolution suggested herein are valid, this study reveals that a better estimate of the significance of corrosion is required to assess the amount of methane-derived carbon that is permanently fixed in seep-carbonates.
Resumo:
Sea cucumbers are dominant invertebrates in several ecosystems such as coral reefs, seagrass meadows and mangroves. As bioturbators, they have an important ecological role in making available calcium carbonate and nutrients to the rest of the community. However, due to their commercial value, they face overexploitation in the natural environment. On top of that, occurring ocean acidification could impact these organisms, considered sensitive as echinoderms are osmoconformers, high-magnesium calcite producers and have a low metabolism. As a first investigation of the impact of ocean acidification on sea cucumbers, we tested the impact of short-term (6 to 12 days) exposure to ocean acidification (seawater pH 7.7 and 7.4) on two sea cucumbers collected in SW Madagascar, Holothuria scabra, a high commercial value species living in the seagrass meadows, and H. parva, inhabiting the mangroves. The former lives in a habitat with moderate fluctuations of seawater chemistry (driven by day-night differences) while the second lives in a highly variable intertidal environment. In both species, pH of the coelomic fluid was significantly negatively affected by reduced seawater pH, with a pronounced extracellular acidosis in individuals maintained at pH 7.7 and 7.4. This acidosis was due to an increased dissolved inorganic carbon content and pCO2 of the coelomic fluid, indicating a limited diffusion of the CO2 towards the external medium. However, respiration and ammonium excretion rates were not affected. No evidence of accumulation of bicarbonate was observed to buffer the coelomic fluid pH. If this acidosis stays uncompensated for when facing long-term exposure, other processes could be affected in both species, eventually leading to impacts on their ecological role.
Resumo:
Next generation telecommunications infrastructures are considered as a principal example of a new technology for sustainable economic growth. From their deployment it is expected that a wealth of innovations – hopefully converted into economic growth – new sources of employment and improved quality of life will result. In line with these prospects, public administrations at supranational, national, regional and local levels have encouraged the development of these new infrastructures. Moreover, in times of economic crisis, public assistance to deploy such networks encompasses the promise of placing a weak economy on the road to prosperity. However, such arguments and political claims clearly require rigorous assessment. In particular, any such assessment must adequately address the appropriate form of modelling that best captures key elements for identifiable progress from next generation access networks (NGAN).
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The obtaining of multiferroicBiFeO3 as a pure single-phase product is particularly complex since the formation of secondary phases seems to be unavoidable. The process by which these secondary impurities are formed is studied by analyzing the diffusion and solidstate reactivity of the Bi2O3–Fe2O3 system. Experimental evidence is reported which indicates that the progressive diffusion of Bi3+ ions into the Fe2O3 particles governs the solidstatesynthesis of the perovskite BiFeO3 phase. However a competition is established between the diffusion process which tends to complete the formation of BiFeO3, and the crystallization of stable Bi2Fe4O9 mullite crystals, which tend to block that formation reaction.
Resumo:
Next generation access networks (NGAN) will support a renewed electronic communication market where main opportunities lie in the provision of ubiquitous broadband connectivity, applications and content. From their deployment it is expected a wealth of innovations. Within this framework, the project reviews the variety of NGAN deployment options available for rural environments, derives a simple method for approximate cost calculations, and then discusses and compares the results obtained. Data for Spain are used for practical calculations, but the model is applicable with minor modifications to most of the rural areas of European countries. The final part of the paper is devoted to review the techno-economic implications of a network deployment in a rural environment as well as the adequacy and possible developments of the regulatory framework involved
Resumo:
Next generation access networks (NGAN) will support a renewed communication structure where opportunities lie in the provision of ubiquitous broadband connectivity, a wide variety of new applications, appealing contents and a general support to the sustainable growth of diverse sectors. From their deployment it is expected a wealth of innovations, jobs creation and a new wave of economic growth. In this paper we discuss which could be the role of Hybrid Fibre Coax (HFC) in the Next Generation Access Network (NGAN) roadmap. Thus, we propose a simplified model for making approximate cost calculations for HFC deployment based on the geographic and sociodemographic characteristics of Spain. Considering the latest evolution of HFC based on DOCSIS 3.0 from integrated (I-CMTS) towards modular (M-CMTS), the results from the model are compared with the most competitive NGAN for ultrabroadband speeds: Fibre to the Home (FTTH) based on Gigabitcapable Passive Optical Networks (GPON)