Comment on Reply to Comment of Finger et al. (2013) on: 'Evidence for an Early-Middle Miocene age of the Navidad Formation (central Chile): Paleontological, paleoclimatic and tectonic implications' of Gutiérrez et al. (2013, Andean Geology 40 (1): 66-78)

Indexación: Web of Science; ScieloIn their answer to our Comment (Finger et al., 2013), Le Roux et al. (2013) misunderstand several of our remarks and present what we view as f lawed arguments, principally their case for a shallow-marine environment for part of the Navidad Formation. We do not wish to see this exchange evolve into an endless discussion, but we feel obligated to clarify some points. We think this is necessary because of history and importance of the Navidad Formation as the reference for the marine Miocene of Chile. Here we also expound upon some concepts relevant to the distinction between shallow-and deep-marine environments

Augmented nodal matrices and normal trees

AbstractAugmented nodal matrices play an important role in the analysis of different features of electrical circuit models. Their study can be addressed in an abstract setting involving two- and three-colour weighted digraphs. By means of a detailed characterization of the structure of proper and normal trees, we provide a unifying framework for the rank analysis of augmented matrices. This covers in particular Maxwell’s tree-based determinantal expansions of (non-augmented) nodal matrices, which can be considered as a one-colour version of our results. Via different colour assignments to circuit devices, we tackle the DC-solvability problem and the index characterization of certain differential–algebraic models which arise in the nodal analysis of electrical circuits, extending several known results of passive circuits to the non-passive context

Index analysis of semistate systems without passivity restrictions

In the last decades, there has been an increasing interest on semistate models based on differential-algebraic equations (DAEs) for the analysis and simulation of non-linear electrical circuits. Modelling techniques such as Node Tableau Analysis (NTA), Augmented Nodal Analysis (ANA), or Modified Nodal Analysis (MNA), the latter used e.g. in the circuit simulation programs SPICE and TITAN, set up network equations in differentialalgebraic form[48, 59, 60, 139]. The index of a DAE circuit model becomes a standard measure for the analytical and numerical difficulties faced in simulations [16, 60, 65]. Roughly speaking, the notion of the index can be thought of as the number of steps that are necessary to split the original differential-algebraic systemin to two uncoupled systems: an algebraic one, and an explicit differential one. In particular, index zero systems amount to explicit ODEs, while for index one DAEs the aforementioned splitting can be obtained in a relatively simple manner. Differential-algebraic systems with an index higher than one, usually called higher index systems, are more difficult and specific approaches are necessary for their simulation (see e.g. [65, Chap. VII]). In this direction, the topological characterization of low index (index less than two) circuit configurations has become increasingly important, and it is performed by current circuit simulators [46]. Characterizations of this type do not only place analytical conditions on the circuit devices but they also demand the existence or absence of certain configurations on the circuit digraph, which retains the electrical nature of the circuit elements but not their specific constitutive equations. In previous works, passivity assumptions on circuit devices have been very helpful to simplify the characterization of the index for the resulting models [48, 131, 139]. These assumptions amount to the positive definiteness of the incremental conductance and reactance matrices, this being equivalent to demanding that all conductances and reactances are positive in uncoupled circuits. Restricting the coupling effects allowed in the circuit, the present work introduces novel tree-based methods allowing us to characterize the index of common nodal models in a more general framework, based on algebraic assumptions on certain trees within the network. This tree-based index calculation generalizes previous results, making it possible to characterize the index of uncoupled circuits including both passive and active devices. Our results focus mainly on the augmented nodal analysis and the modified nodal analysis formulations. While modified nodal analysis models have been widely studied froma non-linear DAE perspective [45, 48, 95, 130, 139], the augmented nodal analysis formulation was presented in [131] as an intermediate step between MNA and NTA, preserving the index one conditions of node tableau. In the present work, we employ different types of trees for the characterization of low index configurations in the different models. Index one ANA systems are characterized by certain conditions on the proper trees in the circuit. In turn, index one conditions for MNA are stated in terms of normal trees. Proper and normal trees were introduced by Bashkow [11] and Bryant [21, 22, 23], respectively. A key step in our proofs is the factorization of the matrices describing index one for ANA and MNA, where the Cauchy-Binet formula allows us to split the topological component of the circuit from the characteristics of the devices. The study of the above-mentioned matrices, in particular of those describing index zero for MNA and index one for ANA, leads to the notion of an augmented nodal matrix. In the abstract terms of a coloured digraph, this type of matrix allows us not only to characterize low index configurations but also to analyze other problems in circuit theory, such as the DC-solvability condition for equilibriump oints of well-posed circuits [31, 46, 54, 55, 130, 137, 138]. In this context, the characterization of proper and normal trees in abstract coloured digraphs defines a result of independent interest, which allows us to delve into the kernel of the augmented nodal matrix. Regarding this problem, we prove that the normal trees of a green/blue connected graph are defined by all possible combinations of a forest of the green subgraph and a tree of the so-called blue-cut minor. Similarly, for three-colour connected graphs, we show that normal trees can be characterized in terms of red-cut minors and normal forests of the green/blue subgraph. Finally, in order to study the rank of augmented nodal matrices for problems including couplings or controlled branches, we present the novel notions of a balanced tree and a regular tree pair. Although they are introduced in the simpler and more general context of coloured digraphs, both notions can be directly transposed to a circuit theoretic setting. This allows us to examine networks including coupled capacitors or Voltage-Controlled Current Sources (VCCS), which are present in most integrated circuits [5, 87, 136]. Specifically, we present here characterizations of the DC-solvability problemand index one configurations in ANA models of circuits including controlled sources. Additionally, index zero configurations in MNA models are examined for circuits including coupled capacitors

The technical quality of the service provided by adventure companies in Spain, Italy and Costa Rica

There are various ways to capture the quality of service in a company. In this case we have tried to identify the level of technical quality, through seventy direct questions divided into seven major blocks of content for adventure tourism. Data collection was skewed in relation to the three countries in which the study was conducted: Costa Rica, Spain and Italy. There was significant differentiation with regard to compliance among the three countries in the different parameters analyzed, and a cultural variable had to be recognized for the final analysis of the results. Specific differentiated conclusions were drawn according to the parameters and the respective country

Radical Titanocene Promoted Coupling of Epoxides and Vinyl Sulfones

[EN]A radical coupling reaction of diverse vinyl sulfones and epoxides was mediated by Cp2TiCl (Cp = cyclopentadienyl) to provide a straightforward synthetic pathway to hydroxy sulfones. The reaction was successfully achieved by using either an excess or a catalytic amount of the TiIII reagent. The scope of the reaction was studied for several different functionalized and substituted epoxides and vinyl sulfones

Radical Cyclization of Epoxy Vinyl- and Allylsulfones Promoted by Titanocene Chloride

[EN]A titanocene-mediated intramolecular radical addition of different epoxy vinyl- and allylsulfones has been achieved. Five- and six-membered ring products were obtained in good to excellent yields in the presence of both 2.2 and 0.2 equiv of Cp2TiCl. A novel double-activation strategy allowed us to achieve small-size rings such as cyclobutanes and cyclopropanes

Titanocene-Promoted Intermolecular Couplings of Epoxides with Nitriles. An Easy Access to β-Hydroxyketones

[EN]Radical couplings of epoxides and nitriles mediated by Cp2TiCl provide a diastereoselective route to the synthesis of β-hydroxyketones. The conditions of this “aldol-like” reaction are mild enough to avoid the dehydration of the β-hydroxyketone. The scope of the coupling reaction with functionalized and tetrasubstituted epoxides has been studied. The radical character of the coupling reactions is demonstrated

Titanocene‐Promoted Eliminations on Epoxy Alcohols and Epoxy Esters

[EN]The reaction of a series of 2,3-epoxy alcohols and the corresponding formates, acetates, and benzoates promoted by Cp2TiCl has been studied. The different outcome of the reaction of epoxy derivatives has been rationalized in terms of mechanistically biased processes. After homolytic oxirane cleavage, four main types of reaction were found: dehydroxylation, decarboxylation, dehydrogenation, and deoxygenation. The reaction products varied according to the substitution pattern. The radical nature of these eliminations is demonstrated

Nuevos antecedentes sobre la evolución tectonosedimentaria de los depósitos Plio-Pleistocenos del Valle Central de Chile, entre los 36°50´Sy 38°50´S

El Valle Central de Chile se encuentra situado entre la Cordillera de la Costa y la Cordillera de los Andes y se extiende en dirección N-S desde el sur de Santiago hasta la Península de Taitao. El Valle Central posee un relleno Cenozoico compuesto por unidades volcánicas y sedimentarias marinas y continentales. Los depósitos más jóvenes han sido asignados al periodo Plio?Pleistoceno y se habrían depositado sobre las unidades marinas y volcánicas del Oligo-Mioceno. Las secuencias han sido asignadas previamentea la Formación Mininco, Formación Banco del Laja, Formación La Montaña, Formación Malleco, Abanico Volcanoclástico de Muco, Conglomerados Raluncoyán y Rodados Multicolores. Dichas unidades han sido interpretadas en trabajos anteriores como sucesiones lagunares, glaciares, fluviales, aluviales y laháricas. Estos trabajos se realizaron sin estudios estratigráficos ni análisisde facies detallados, por lo que existe una problemática en cuanto a la cronoestratigrafía y el ambiente sedimentario de estos depósitos. En este trabajo se llevan a cabo estudios estratigráficos y análisis de facies en las unidades que afloran a lo largo del Valle Central, entre los 36°50´S y 38°50´S. Los principales resultados y conclusiones son:1. La Fm Malleco se correlaciona con la Fm La Montaña, sobreyace a la Fm Mininco y se interdigita con la Fm Banco del Laja, la que a su vez se correlaciona con la unidad Abanico Volcanoclástico de Muco. Se desconoce la relación de estasunidades con los Conglomerados Raluncoyán.2. Los depósitos se disponen en inconformidad sobre rocas intrusivas del Batolito Costero y en discordancia sobre rocas volcánicas Oligo-Miocenas en el Valle Central, que se presentan en forma de cerros islas.3. Se postula una equivalencia entre los Rodados Multicolores y la Fm Malleco.4. Los depósitos en cuestión corresponderían principalmente a sucesiones fluviales y laháricas provenientes desde la Cordillera de los Andes a excepción de los Conglomerados Raluncoyán los cuales tienen un aporte sedimentario local proveniente desde la Formación Pilmahue.5. Las características litoestratigráficas de estos depósitos sugieren una gran denudación del margen andino, que estaría relacionada con un alzamiento de este durante el Plio-Pleistoceno.6. Una subsidencia en el Valle Central entre el Plio-Pleistoceno habría permitido la acumulación de estos depósitos y la ocurrencia de knickpoints indicarían un alzamiento reciente en parte de este.Fil: Anavalon, Anibal. Universidad de Concepción; ChileFil: Encinas, Alfonso. Universidad de Concepción; ChileFil: Sagripanti, Lucía. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; ArgentinaFil: Otero, Joaquin. Universidad Austral de Chile; ChileXV Congreso Geológico ChilenoConcepciónChileUniversidad de ConcepciónColegio de Geólogos de ChileSociedad Geológica de Chil

Methodology for ranking customer segments by their suitability for distributed energy resources applications

[EN] A massive implementation of distributed energy resources (DER) requires the development of innovative approaches to identify, based on the energy market requirements, fast track options for such implementation. These approaches should assess the potential for DER of the different customer segments and simulate DER adoption for those with highest potential in order to evaluate accurately the impact of this implementation on the different energy actors. This paper introduces a methodology to asses the DER implementation potential of customer segments based on a multi-criteria analysis, considering DER as including distributed generation (DG), distributed storage (DS) and local trading strategiest(1) (LTS). Application of the methodology to the commercial sector for DG installation, considering different motivations (cogeneration, renewable, emergency generator and peaking power) and the obtained results for five different segments in this sector are presented. (C) 2006 Elsevier Ltd. All rights reserved.This work was completed in the framework of the EUDEEP Integrated Project of the 6th EU RTD Framework Programme. The authors deeply thank all the participants in the projects for their help and support that made this work possible.Alfonso-Solar, D.; Pérez-Navarro, Á.; Encinas Redondo, N.; Álvarez, C.; Rodríguez-García, J.; Alcázar-Ortega, M. (2007). Methodology for ranking customer segments by their suitability for distributed energy resources applications. Energy Conversion and Management. 48(5):1615-1623. doi:10.1016/j.enconman.2006.11.006S1615162348