Estimation of full moment tensors, including uncertainties, for earthquakes, volcanic events, and nuclear explosions

Thesis (Ph.D.) University of Alaska Fairbanks, 2016We present a catalog of full seismic moment tensors for 63 events from Uturuncu volcano in Bolivia. The events were recorded during 2011-2012 in the PLUTONS seismic array of 24 broadband stations. Most events had magnitudes between 0.5 and 2.0 and did not generate discernible surface waves; the largest event was Mw 2.8. For each event we computed the misfit between observed and synthetic waveforms, and we used first-motion polarity measurements to reduce the number of possible solutions. Each moment tensor solution was obtained using a grid search over the six-dimensional space of moment tensors. For each event we show the misfit function in eigenvalue space, represented by a lune. We identify three subsets of the catalog: (1) 6 isotropic events, (2) 5 tensional crack events, and (3) a swarm of 14 events southeast of the volcanic center that appear to be double couples. The occurrence of positively isotropic events is consistent with other published results from volcanic and geothermal regions. Several of these previous results, as well as our results, cannot be interpreted within the context of either an oblique opening crack or a crack-plus-double-couple model. Proper characterization of uncertainties for full moment tensors is critical for distinguishing among physical models of source processes. A seismic moment tensor is a 3×3 symmetric matrix that provides a compact representation of a seismic source. We develop an algorithm to estimate moment tensors and their uncertainties from observed seismic data. For a given event, the algorithm performs a grid search over the six-dimensional space of moment tensors by generating synthetic waveforms for each moment tensor and then evaluating a misfit function between the observed and synthetic waveforms. 'The' moment tensor M₀ for the event is then the moment tensor with minimum misfit. To describe the uncertainty associated with M₀, we first convert the misfit function to a probability function. The uncertainty, or rather the confidence, is then given by the 'confidence curve' P(V), where P(V) is the probability that the true moment tensor for the event lies within the neighborhood of M that has fractional volume V. The area under the confidence curve provides a single, abbreviated 'confidence parameter' for M0. We apply the method to data from events in different regions and tectonic settings: 63 small (Mw 4) earthquakes in the southern Alaska subduction zone, and 12 earthquakes and 17 nuclear explosions at the Nevada Test Site. Characterization of moment tensor uncertainties puts us in better position to discriminate among moment tensor source types and to assign physical processes to the events

Artefatos e campos de ação

The aim of this paper is to defend a theory of artifacts based on the concept of field of action, as an alternative to functional, intentional and double-nature theories. The proposed theory is realistic about the existence of entities that are artifacts, and praxiological about the nature of such entities. The basis of the theory is the concept of action; from this concept, the concepts of field of action and participants in a field of action, namely, agents and objects, are introduced. An artifact is defined as an object that has a part and role in the achievement of an action.O objetivo desse texto é defender uma teoria dos artefatos com base no conceito de campo de ação, como uma alternativa às teorias funcionalistas, intencionalistas e também às de dupla natureza. A teoria proposta é realista quanto à existência de entidades que são artefatos, e praxiológica quanto à natureza de tais entidades. A base da teoria é o conceito de ação; a partir desse conceito introduzem-se os conceitos de campo de ação e de partícipes de um campo de ação, a saber, agentes e objetos. Um artefato é definido como um objeto que tem parte e papel na consecução de uma ação.O objetivo desse texto é defender uma teoria dos artefatos com base no conceito de campo de ação, como uma alternativa às teorias funcionalistas, intencionalistas e também às de dupla natureza. A teoria proposta é realista quanto à existência de entidades que são artefatos, e praxiológica quanto à natureza de tais entidades. A base da teoria é o conceito de ação; a partir desse conceito introduzem-se os conceitos de campo de ação e de partícipes de um campo de ação, a saber, agentes e objetos. Um artefato é definido como um objeto que tem parte e papel na consecução de uma ação

Preface - Personal perspectives in nonlinear science : Looking back, looking forward

Peer reviewedPublisher PD

Resiliently evolving supply-demand networks

Peer reviewedPublisher PD

Understanding the Factors That Make Public Participation Effective in Health Policy and Planning: A Realist Synthesis

Although researchers argue for the importance of involving the public in developing health policy, there has been little focus on central research questions – such as what techniques of public participation work, in what circumstances, and why. This paper presents a realist synthesis which identifies and explains the underlying mechanisms and specific contextual factors that lead to effective public participation in health policy and planning. Peer-reviewed, English language literature was searched, which resulted in 77 articles for review and synthesis. This synthesis uncovered the underlying mechanism of ‘political commitment’ that generates public participation effectiveness. The other three possible underlying mechanisms, namely: ‘partnership synergy’, ‘inclusiveness’ and ‘deliberativeness’, were found to potentially provide further explanation on public participation effectiveness for health policy and planning. The findings of this review provide evidence that can be useful to health practitioners and decision-makers to actively involve the public when drafting public health policies and programs and, more importantly, guide them in deciding which strategies to best employ for which contexts

Recent Advances in \u3cem\u3eStylosanthes\u3c/em\u3e Research in Tropical America

The potential of neotropical savannas is very large for pasture-based livestock systems. There are 250 million ha of well-drained lowland savannas in the American tropics. Over 200 million ha are situated in the Cerrados region of Brazil. The Cerrados support 42% of the national herd. Although these ranges support large populations of livestock, productivity is generally low. Poor nutritive value of native pastures and monospecific swards of Brachiaria spp. is the principal cause of this low productivity, especially in the dry season when these grasslands often provide no more than 60% of the animal\u27s maintenance requirements. The best option to increase pasture/livestock productivity is the use of improved pastures, particularly those based on adapted tropical legume-grass associations. Research in tropical America was concentrated on the evaluation and selection of Stylosanthes species adapted to low fertility acid-soils and resistant to anthracnose (Colletotrichum gloeosporioides). Anthracnose is considered the major limitation to the commercial use of Stylosanthes on a world-wide basis

Phenylethyl isothiocyanate extracted from watercress by-products with aqueous micellar systems: development and optimisation

Phenylethyl isothiocyanate (PEITC) was reported as a useful antioxidant, anti-inflammatory, and chemopreventive agent. Due to technological and stability issues, it is necessary to be able to extract PEITC from its natural matrix (watercress) through sustainable and scalable methodologies. In this article, we explored, for the first time, the extractive capacity of aqueous micellar systems (AMSs) of two non-ionic surfactants. For this, we compared the AMSs with conventional organic solvents. Furthermore, we developed and optimised a new integral PEITC production and extraction process by a multifactorial experimental design. Finally, we analysed the antioxidant capacity by the oxygen radical absorbance capacity (ORAC) and ABTS methods. As results, the AMSs were able to extract PEITC at the same level as the tested conventional solvents. In addition, we optimised by response surface methodology the integrated process (2.0% m/m, 25.0 C, pH 9.0), which was equally efective (ca. 2900 g PEITC/g watercress), regardless of the surfactant used. The optimal extracts showed greater antioxidant capacity than pure PEITC, due to other antioxidant compounds extracte in the process. In conclusion, by the present work, we developed an innovative cost-effective and low environmental impact process for obtaining PEITC extracts from watercress by-products.N/

Crecimiento de renovales de Drimys winteri después de 16 años de aplicados distintos tratamientos de raleo en las cordilleras de los andes y de la costa en Chile

Secondary Drimys winteri forests are among the most common and productive forests in south-central Chile. However, their management has been scarce or many times inadequate due to lack of silvicultural knowledge. In 1986 and 1990 three field experiments were installed; one in the Coastal range of the province of Ranco (40° 09' S) and two in the Andean range of the province of Llanquihue (41° 30' S), to evaluate the effects of different intensities of thinning on the growth and mortality of 28-year-old Drimys winteri secondary forests. After 16 and 10 years of evaluation, great differences were observed among treatments within and between the three experiments. In Hueicoya (Coastal Range) plots thinned at a distance of 3 m had the highest productivity. In Lenca A (Andean Range) the high mortality rates due to windfalls in the plots with trees spaced at 3 and 4 m caused the control plots to have the highest productivity rates. In Lenca B (Andean Range) plots thinned at 2.5 m distance between trees had no significant differences with control plots. At an equal thinning intensity the responses were very different among experiments. We discuss that site quality, residual composition, exposure to winds and rooting characteristics may have influenced these results. In general, it is recommended to thin at 25-45% residual densities (2-3 m distance between trees at the age of thinning of 9-12 cm quadratic stand diameter), but always depending on the risk of windfall

Coherent and incoherent J/ΨJ/\Psi photoproduction in PbPbPbPb collisions at the LHC, HE -- LHC and FCC

The coherent and incoherent $J/\Psi$ photoproduction in $PbPb$ collisions are investigated considering the possible states of nucleon configurations in the nuclear wave function and taking into account of the non - linear corrections to the QCD dynamics. The cross sections and the rapidity and transverse momentum distributions are estimated for the energies of the next run of the LHC, High -- Energy LHC and Future Circular Collider. Our results indicate that a future experimental analysis of these processes will be useful to discriminate between different approaches for the QCD dynamics as well to improve our description of the gluon saturation effects.Comment: 7 pages, 3 figures, 1 tabl