895 resultados para EARTHS


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Is it possible for Indigenous ways of knowing, which draw on earth song and storywork, to find a place within the academy? Indigenous peoples recognise that the earth has a song, which we can listen to as story. In return, we can sing our story to the world and of the world. In this paper, the authors explore their own stories and songs. They explain the ways that listening to the earth’s song and working with stories can inform their work in the academy – as teachers who support younglings to hear their voices and develop their own songs, and as the writers and tellers of curriculum. The authors ask whether it is possible for Indigenous academics to combine their academic work with Indigenous ways of knowing. They argue that, not only is the combination possible, it can be used to create a harmonious voice that will help them to reclaim their power as Indigenous academic women.

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Two series of complexes of meconic acid (H3 Mec) with rare-earths have been prepared by varying the preparative procedure. The compounds have the general formulae, [Ln(Mec) (H2O)2]·3 H2O (whereLn=La, Ce, Pr, Nd, Sm, Ho and Y) and [Ln(HMec) (H2 Mec) (H2O)2]·4 H2O (whereLn=La, Pr, Nd and Sm). The infrared spectral data indicate that the carboxylate groups are bound to the rare-earth metal in a bidentate fashion. Thermal studies indicate that two water molecules are coordinated in each case. The complexes are probably polymeric.

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Achieving sustainable consumption patterns is a crucial step on the way towards sustainability. The scientific knowledge used to decide which priorities to set and how to enforce them has to converge with societal, political, and economic initiatives on various levels: from individual household decision-making to agreements and commitments in global policy processes. The aim of this thesis is to draw a comprehensive and systematic picture of sustainable consumption and to do this it develops the concept of Strong Sustainable Consumption Governance. In this concept, consumption is understood as resource consumption. This includes consumption by industries, public consumption, and household consumption. Next to the availability of resources (including the available sink capacity of the ecosystem) and their use and distribution among the Earth’s population, the thesis also considers their contribution to human well-being. This implies giving specific attention to the levels and patterns of consumption. Methods: The thesis introduces the terminology and various concepts of Sustainable Consumption and of Governance. It briefly elaborates on the methodology of Critical Realism and its potential for analysing Sustainable Consumption. It describes the various methods on which the research is based and sets out the political implications a governance approach towards Strong Sustainable Consumption may have. Two models are developed: one for the assessment of the environmental relevance of consumption activities, another to identify the influences of globalisation on the determinants of consumption opportunities. Results: One of the major challenges for Strong Sustainable Consumption is that it is not in line with the current political mainstream: that is, the belief that economic growth can cure all our problems. So, the proponents have to battle against a strong headwind. Their motivation however is the conviction that there is no alternative. Efforts have to be taken on multiple levels by multiple actors. And all of them are needed as they constitute the individual strings that together make up the rope. However, everyone must ensure that they are pulling in the same direction. It might be useful to apply a carrot and stick strategy to stimulate public debate. The stick in this case is to create a sense of urgency. The carrot would be to articulate better the message to the public that a shrinking of the economy is not as much of a disaster as mainstream economics tends to suggest. In parallel to this it is necessary to demand that governments take responsibility for governance. The dominant strategy is still information provision. But there is ample evidence that hard policies like regulatory instruments and economic instruments are most effective. As for Civil Society Organizations it is recommended that they overcome the habit of promoting Sustainable (in fact green) Consumption by using marketing strategies and instead foster public debate in values and well-being. This includes appreciating the potential of social innovation. A countless number of such initiatives are on the way but their potential is still insufficiently explored. Beyond the question of how to multiply such approaches, it is also necessary to establish political macro structures to foster them.

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There are several good reasons why Earth and Space Science should be a part of any science curriculum. Nearly everything we do each day is connected in some way to the Earth: to its land, oceans, atmosphere, plants and animals. By 2025, eight billion people will live on Earth. If we are to continue extracting resources to maintain a high quality of life, then it is important that our children are scientifically literate in a way that allows them to exploit the Earth’s resources in a sustainable way. People who understand how earth systems work can make informed decisions and may be able to help resolve issues surrounding clean water, urban planning and development, global climate change and the use and management of natural resources.

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The monochloroacetates of lanthanum, praseodymium and neodymium of the composition M(ClCH2COO)3·2H2O have been prepared and characterised. The compounds behave as non-electrolytes in dimethylformamide. The infrared spectra are consistent with bidentate coordination of the carboxylate group and show the presence of two types of water molecules, coordinated, and free. With six oxygen atoms from the three acetato groups and one from the water bonded to the metal, a coordination number of seven has been assigned to the rare earths in these compounds. On pyrolysis, the chloroacetates lose water at ~130 °C and yield the oxychlorides at ~500 °C. The X-ray powder patterns of the chloroacetates have been indexed for the monoclinic system, with four molecules per unit cell.

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We report x-ray photoelectron spectroscopic investigation of RuSr2Eu1.5Ce0.5Cu2O10 with ferromagnetic T-C similar to 100 K and a superconducting transition temperature of similar to 30 K compared with RuSr2EuCeCu2O10, which is a ferromagnetic (T-C similar to 150 K) insulator. Our results show that the rare earths, Eu and Ce, are in 3+ and 4+ states, respectively. Comparing the Ru core level spectra from these compounds to those from two Ru reference oxides, we also show that Ru in these ruthenocuprates is always in 5+ state, suggesting that the doped holes in the superconducting compound arising from the substitution of Ce4+ by Eu3+ are primarily in the Cu-O plane, in close analogy to all other doped high-T-C cuprates. Analysis of Cu 2p spectra in terms of a configuration interaction model provides a quantitative description of the gross electronic structures of these ruthenocuprates.

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A hydrothermal reaction of the acetate salts of the rare-earths, 5-aminoisophthalic acid (H(2)AIP), and NaOH at 150 degrees C for 3 days gave rise to a new family of three-dimensional rare-earth aminoisophthalates, M(mu(2)-OH)(C8H5NO4)] M = Y3+ (I), La3+ (II), Pr3+ (III), Nd3+ (IV), Sm3+ (V), Eu3+ (VI), Gd3+ (VII), Dy3+ (VIII), and Er3+ (IX)]. The structures contain M-O(H)-M chains connected by AIP anions. The AIP ions are connected to five metal centers and each metal center is connected with five AIP anions giving rise to a unique (5,5) net. To the best of our knowledge, this is the first observation of a (5,5) net in metal-organic frameworks that involve rare-earth elements. The doping of Eu3+/(3+) ions in place of Y3+/ La3+ in the parent structures gave rise to characteristic metal-centered emission (red = Eu3+, green = Tb3+). Life-time studies indicated that the excited emission states in the case of Eu3+ (4 mol-% doped) are in the range 0.287-0.490 ms and for Tb3+ (4 mol-% doped) are in the range of 1.265-1.702 ms. The Nd3+-containing compound exhibits up-conversion behavior based on two-photon absorption when excited using lambda = 580 nm.

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A wet chemical route is developed for the preparation of Sr2CeO4 denoted the carbonate-gel composite technique. This involves the coprecipitation of strontium as fine particles of carbonates within hydrated gels of ceria (CeO2.xH(2)O, 40earths is carried out at the co-precipitation stage. The photoluminescence (PL) observed for Sr2CeO4 originates from the Ce4+-O2- charge-transfer (CT) transition resulting from the interaction of Ce4+ ion with the neighboring oxide ions. The effect of next-nearest-neighbor (NNN) environment on the Ce4+-O2- CT emission is studied by doping with Eu3+, Sm3+ or Yb3+ which in turn, have unique charge-transfer associated energy levels in the excited states in oxides. Efficient energy transfer occurs from Ce4+-O2- CT state to trivalent lanthanide ions (Ln(3+)) if the latter has CT excited states, leading to sensitizer-activator relation, through non-resonance process involving exchange interaction. Yb3+-substituted Sr2CeO4 does not show any line emission because the energy of Yb3+-O2- CT level is higher than that of the Ce4+-O2- CT level. Sr2-xEuxCeO4+x/2 shows white emission at xless than or equal to0.02 because of the dominant intensities of D-5(2)-F-7(0-3) transitions in blue-green region whereas the intensities of D-5(0)-F-7(0-3) transitions in orange-red regions dominate at concentrations xgreater than or equal to0.03 and give red emission. The appearance of all the emissions from D-5(2), D-5(1) and D-5(0) excited states to the F-7(0-3) ground multiplets of Eu3+ is explained on the basis of the shift from the hypersensitive electric-dipole to magnetic-dipole related transitions with the variation in site symmetry with increasing concentration of Eu3+. White emission of Sr2-x SmxCeO4+x/2 at xless than or equal to0.02 is due the co-existence of Ce4+-O2- CT emission and (4)G(4)(5/2)-H-6(J) Sm3+ transitions whereas only the Sm3+ red emission prevails for xgreater than or equal to0.03. The above unique changes in PL emission features are explained in terms of the changes in NNN environments of Ce4+. Quenching of Ce4+-O2- CT emission by other Ln(3+) is due to the ground state crossover arising out of the NNN interactions.

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In last 30 years innovative research in the area of auto exhaust catalysis is being developed and CeO2 has been found to play a major role in this area due to its unique redox properties. In this review, auto exhaust emission and its impact on earth’s environment, global concern and recent advances in science and technology in automotive exhaust catalysis have been documented. A new preparative method of dispersing metal ions by solution combustion technique over CeO2 and TiO2 resulting mainly Ce1−xMxO2−δ, Ti1−xMxO2−δ and Ce1−x−yTixMyO2−δ (M = Pd, Rh and Pt) catalysts, structure of these materials, their catalytic properties towards auto exhaust catalysis, structure–property relation and mechanism of catalytic reactions are accounted here. In these materials, metal ions are incorporated into substrate matrix to a certain limit in the solid solution form and we have established a new direction in heterogeneous catalysis by turning to the concept of dispersed metal ions as catalytically active sites from the conventionally nurtured idea of metal particles as active centers for catalysis.

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Eu3+-activated layered LnOCl (Ln=La and Gd) phosphors were synthesized by the conventional solid-state method at relatively low temperature (700 degrees C) and shorter duration of 2 h. The structural parameters were refined by the Rietveld refinement analysis and confirmed by the high resolution transmission electron microscopy (HRTEM). Both the compounds were crystallized in the tetragonal structure with space group P4/nmm (No. 129). The homogeneity of the elements were analyzed by TEM mapping and found to be uniformly distributed. The photoluminescence spectra revealed that the intensity of D-5(0)-> F-7(2) transition (619 nm) was more intense in Eu3+-activated GdOCl compared to LaOCl. This was due to the property of Gd3+ ions to act as an intermediate sublattice to facilitate the energy transfer to Eu3+ ions. Intensity parameters and radiative properties such as transition probabilities, radiative lifetime and branching ratio were calculated using the Judd-Ofelt theory. The CIE color coordinates result revealed that the Eu3+-activated GdOCl (0.641, 0.354) phosphor was close to the commercial red phosphors like, Y2O3:Eu3+ (0.645, 0.347), (Y2OS)-S-2:Eu3+ (0.647, 0.343) and National Television System Committee (NTSC) (0.67, 0.33). The results suggest that the present GdOCl:Eu3+ compound acts as a potential candidate for red phosphor materials.

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Large earthquakes can be viewed as catastrophic ruptures in the earth’s crust. There are two common features prior to the catastrophe transition in heterogeneous media. One is damage localization and the other is critical sensitivity; both of which are related to a cascade of damage coalescence. In this paper, in an attempt to reveal the physics underlying the catastrophe transition, analytic analysis based on mean-field approximation of a heterogeneous medium as well as numerical simulations using a network model are presented. Both the emergence of damage localization and the sensitivity of energy release are examined to explore the inherent statistical precursors prior to the eventual catastrophic rupture. Emergence of damage localization, as predicted by the mean-field analysis, is consistent with observations of the evolution of damage patterns. It is confirmed that precursors can be extracted from the time-series of energy release according to its sensitivity to increasing crustal stress. As a major result, present research indicates that the catastrophe transition and the critical point hypothesis (CPH) of earthquakes are interrelated. The results suggest there may be two cross-checking precursors of large earthquakes: damage localization and critical sensitivity.

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The melt flow and temperature distribution in a 200 mm silicon Czochralski furnace with a cusp magnetic field was modeled and simulated by using a finite-volume based FLUTRAPP ( Fluid Flow and Transport Phenomena Program) code. The melt flow in the crucible was focused, which is a result of the competition of buoyancy, the centrifugal forces caused by the rotations of the crucible and crystal, the thermocapillary force on the free surfaces and the Lorentz force induced by the cusp magnetic field. The zonal method for radiative heat transfer was used in the growth chamber, which was confined by the crystal surface, melt surface, crucible, heat shield, and pull chamber. It was found that the cusp magnetic field could strength the dominant counter-rotating swirling flow cell in the crucible and reduce the flow oscillation and the pulling-rate fluctuation. The fluctuation of dopant and oxygen concentration in the growing crystal could thus be smoothed.

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数值实验是地幔对流研究的基本方法。本文概述了近二十年地幔对流研究的主要进展,介绍并评价了每个研究阶段所提出的新概念和新思想。最后,着重讨论了上地幔与全地幔对流的论争。

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The mission of the National Oceanic and Atmospheric Administration (NOAA) is to understand and predict changes in the Earth’s environment and conserve and manage coastal and marine resources to meet our nation’s economic, social and environmental needs (NOAA, 2004). In meeting its marine stewardship responsibilities, NOAA seeks to ensure the sustainable use of resources and balance competing uses of coastal and marine ecosystems, recognizing both their human and natural components (NOAA, 2004). Authorities for executing these responsibilities come from over 90 separate pieces of Federal legislation, each with unique requirements and responsibilities. Few of these laws explicitly mandate an ecosystem approach to management (EAM) or supporting science. However, resource managers, the science community, and increasingly, the public, are recognizing that significantly greater connectedness among the scientific disciplines is needed to support management and stewardship responsibilities (Browman and Stergiou, 2004; 2005). Neither NOAA nor any other science agency can meet the increasing demand for ecosystem science products addressing each of its mandates individually. Even if it was possible, doing so would not provide the integration necessary to solve the increasingly complex array of management issues. This focus on the integration of science and management responsibilities into an ecosystem view is one of the centerpieces of the U.S. Commission on Ocean Policy’s report (USCOP, 2004), and the Administration’s response to that report in the U.S. Ocean Action Plan (CEQ, 2004). (PDF contains 100 pages)