Large restricted sumsets in general abelian group

Let A, B and S be three subsets of a finite Abelian group G. The restricted sumset of A and B with respect to S is defined as A\wedge^{S} B= {a+b: a in A, b in B and a-b not in S}. Let L_S=max_{z in G}| {(x,y): x,y in G, x+y=z and x-y in S}|. A simple application of the pigeonhole principle shows that |A|+|B|>|G|+L_S implies A\wedge^S B=G. We then prove that if |A|+|B|=|G|+L_S then |A\wedge^S B|>= |G|-2|S|. We also characterize the triples of sets (A,B,S) such that |A|+|B|=|G|+L_S and |A\wedge^S B|= |G|-2|S|. Moreover, in this case, we also provide the structure of the set G\setminus (A\wedge^S B).Comment: Paper submitted November 15, 2011. To appear European Journal of Combinatorics, special issue in memorian Yahya ould Hamidoune (2013

Improved analytical method for chemical analysis of cast irons. Application to castings with chunky graphite

Chunky graphite is a particular form of graphite degeneracy that appears in the centre of large iron castings, with a well-defined transition from the outer unaffected area and the inner affected one. All previous works that looked for macrosegration to explain the phenomenon concluded that there are no significant composition differences between the inner and outer parts of such castings. This was challenged again because the analytical methods generally used for chemical analysis are not efficient for low-level elements. Accordingly, an ICP-MS procedure has been developed and validated to replace the usual ICP-OES method. Together with the usual methods for analysis of C, S and Si, this ICP-MS procedure has been applied to characterize chemical heterogeneities in a large block with chunky graphite in its centre, and to a standard part for comparison. It could be concluded that no macrosegregation has built up during the solidification process of the block investigated, i.e. that chunky graphite appearance is not related to any composition changes at the scale of the cast parts, in particular of elements known to affect graphite shape such as Ce, Mg, Sb, S,

Global Equilibrium Exchange Rates: Euro, Dollar, "Ins," "Outs," and Other Major Currencies in a Panel Cointegration Framework

This paper presents a methodology for the calculation of bilateral equilibrium exchange rates for a panel of currencies in a way that guarantees consistency at the global level. A theoretical model, which encompasses the balance of payments and the Balassa-Samuelson approaches to real exchange rate determination, shows that the stock of net foreign assets and the evolution of sectoral prices are the fundamentals underlying the behavior of the real exchange rate. An unobserved components methodology in a cointegration framework allows us to identify a time-varying equilibrium real exchange rate, and deviations from this equilibrium provide an estimate of the degree of multilateral misalignment. Finally, an algebraic transformation converts these multilateral equilibrium real rates into bilateral equilibrium nominal rates. The results uncover, inter alia, that by the start of Stage III of EMU the euro was significantly undervalued against the dollar and even more against the pound, but overvalued relative to the yen. Regarding EMU currencies, it is shown that the four major EMU currencies locked their parities with the euro at a rate close to equilibrium.

Preparación y caracterización de compuestos poliméricos a base de aceite de linaza epoxidado y nanotubos de carbono

Establecer las condiciones de preparación de compuestos poliméricos a base de aceite de linaza y nanotubos de carbono no modificados y modificados químicamente, y llevar a cabo su caracterización por FT-IR, SEM, propiedades eléctricasSe alcanzó el objetivo del proyecto. Se analizó el efecto de la funcionalización de nanotubos de carbono de pared múltiple (NTCPM) en la dispersión en una matriz polimérica. Esa dispersión se evaluó indirectamente mediante la medición de la resistencia eléctrica y posterior cálculo de la resistividad de películas de los compuestos poliméricos a base de Aceite de linaza epoxidado (ALE) y NTCPM sin modificar y modificados superficialmente por oxidación química, a diferentes composiciones de NTCPM. El método de dispersión y la observación cualitativa de ésta, se realizó como se estableció en la metodología, observando cada hora, en diferentes disolventes, un concentración dada de NTCPM , en un microscopio óptico. Se determinó como el tiempo de dispersión adecuado, aquel en donde se observaron en mayoría, NTCPM individuales, siendo el mejor disolvente la Dimetil Formamida (DMF). El tiempo varió acorde al tipo de NTC empleados. Con los datos de resistividad, se construyeron las curvas de percolación de las tres series de compuestos generadas y se modeló la concentración crítica

Density and gender segregation effects in the culture of the caridean ornamental red cherry shrimp Neocaridina davidi Bouvier, 1904 (Caridea: Atyidae)

The effect of density on growth, sex ratio, survival, and biochemical composition of the red cherry shrimp, Neocaridina davidi Bouvier, 1904, was studied to determine optimum rearing conditions in this ornamental species. It was tested whether gender segregation affected growth and survival of the species. To test the effect of density (Experiment 1), hatched juvenile shrimp were kept at three different densities: 2.5, 5, and 10 individuals l-1 (D2.5, D5 and D10, respectively). To test the effect of gender segregation (Experiment 2), 30-day juveniles were reared in three conditions: culture with only females, culture with only males, and mixed culture (females: males 1:1) at 5 individuals l-1 density. Experiments lasted 90 days, and shrimp were weighted either every 30 days (Experiment 1) or 15 days (Experiment 2). At day 90, females kept at D2.5 weighted 45% more than females stocked at D10 (P 0.05). Males at D2.5 weighted 29% more than D5 and D10 (P < 0.05). Survival was high and unaffected by treatment. Sexual differentiation did not differ among treatments. Females from D2.5 had the lowest lipid and protein content, which would occur if they had a higher spawning. Males from D2.5 had higher content of proteins, probably due to their larger size. Gender segregation had no effect over growth and survival; females grew up to a larger size than males both in monosex and mixed culture. It was shown that given to their non-aggressive behavior, N. davidi is tolerant to a highdensity condition, which makes it feasible as an ornamental species.Fil: Vázquez, Nicolás Darío. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; ArgentinaFil: Delevati Colpo, Karine. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Limnología "Dr. Raúl A. Ringuelet". Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Limnología; ArgentinaFil: Sganga, Daniela Eliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; ArgentinaFil: Lopez, Laura Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; Argentin

La Infraestructura Verde como alternativa ante la expansión urbana en Santiago de Chile

[EN] The urban expansionist perspective that governs the Modification of the Metropolitan Regulatory Plan of Santiago de Chile (MPRMS-100), and the absence of an integral management of natural and cultural landscape components, is threatening the integrity of the existing ecological matrix. Given this, the concept of Green Infrastructure is presented as a planning tool, capable of addressing land management aspects, from the spatial to the multifunctional that can reconcile urban growth, social prosperity and environmental protection. In that sense, the article aims to define, from the postulates of Landscape Ecology, the elements for the implementation of a primary Green Infrastructure system in San Bernardo, a peripheral commune of the Metropolitan Region of Santiago. This locality faces important challenges in the future urban context as it concentrates almost 40% of the land proposed to be urbanized by the Plan.[ES] La perspectiva expansionista que rige la Modificación del Plan Regulador Metropolitano de Santiago de Chile (MPRMS-100), y la ausencia de una gestión integral de los componentes paisajísticos de valor natural y cultural, está amenazando la integridad de la matriz ecológica existente. Ante esto, la Infraestructura Verde se presenta como una herramienta de planificación capaz de abordar los aspectos ligados a la gestión del suelo, desde lo espacial a lo multifuncional, que puede reconciliar el crecimiento urbano, bienestar social y protección ambiental. En ese sentido, el artículo tiene como objetivo definir, a partir de los postulados de la Ecología del Paisaje, los elementos para la implementación de un sistema primario de Infraestructura Verde en San Bernardo, una comuna periférica de la Región Metropolitana de Santiago. Esta localidad enfrenta importantes desafíos en el contexto urbano futuro ya que concentra el 40% del suelo urbanizable propuesto por el Plan. Lopez Varela, S.; Granados Ortiz, S. (2020). Green Infrastructure as an alternative facing urban expansion in Santiago de Chile. EN BLANCO. Revista de Arquitectura. 12(28):94-105. https://doi.org/10.4995/eb.2020.13017OJS941051228Alves d'Acampora, Bárbara Heliodora. "La conectividad ecológica en los paisajes de manglares de la región metropolitana de Florianópolis, costa Sur de Brasil." PhD diss., Universidad Politécnica de Madrid, 2018.Astorkiza, Inmaculada y Ana María Ferrero. "Expansión urbana y sostenibilidad: Una dicotomía difícil de conciliar." Revista española de control externo 40 (2012): 47-78.Benedict, Mark A. and McMahon, Edward T. Green Infrastructure. Linking Landscapes and Communities. Washington: Island Press, 2006.BID. Banco Interamericano de Desarrollo. "Sostenibilidad Urbana en América Latina y el Caribe." accessed September 21, 2019. https://publications.iadb.org/es/publicacion/16383/sostenibilidad-urbana-en-america-latina-y-el-caribe.Bresciani, Luis. "Planificar la ciudad desde su espacio natural: Brotes verdes de la planificación urbana." In Cerros Isla de Santiago: Construyendo un nuevo imaginario de ciudad a partir de su geografía, 56-75. Santiago de Chile: Fundación Cerros Isla, 2018.Burel, Francoise and Baudry, Jacques. Ecología del paisaje. Conceptos, métodos y aplicaciones. Madrid: Editorial Mundi Prensa, 2001.CEA. Center for Environmental Studies. "The Urban Green Infrastructure of Vitoria-Gasteiz. "accessed September 15, 2019. www.vitoria-gasteiz.org.Centro de Políticas Públicas UC. "Desafíos en la accesibilidad a áreas verdes en la ciudad y vías de solución, en el marco de la Ley de Aportes al espacio público." accessed October 2, 2019. https://politicaspublicas.uc.cl/.De Block, Greet. "Carefully radical or radically careful. Ecology as design motif." In Revising Green Infrastructure: Concepts Between Nature and Design, 29-47. Londres: Editorial CRC Press, 2014.De la Barrera, Francisco, Pamela Bachmann-Vargas and Antonio Tironi. "Ecosystem services research in Chile: a systematic review." Investigaciones Geográficas 50 (2015): 3-18. https://doi.org/10.5354/0719-5370.2015.41171De Mattos, Carlos, Luis Fuentes and Felipe Link. "Tendencias recientes del crecimiento metropolitano en Santiago de Chile. ¿Hacia una nueva geografía urbana?" Revista INVI 29, no 91 (2014): 193-219. https://doi.org/10.4067/S0718-83582014000200006EEA. European Environment Agency. "Green infrastructure and territorial cohesion- The concept of green infrastructure and its integration into policies using monitoring systems." accessed September 25, 2019. https://www.eea.europa.eu/publications/green-infrastructure-and-territorial-cohesion.European Union. "Building a green infrastructure for Europe. Luxembourg: Office for Official Publications of the European Union." accessed January 9, 2019. http://ec.europa.eu/environment/nature/ecosystems/docs/GI-Brochure-210x210-ES-web.pdf.Feria, José María and Jesús Santiago-Ramos. "Funciones ecológicas del espacio libre y planificación territorial en ámbitos metropolitanos: perspectivas teóricas y experiencias recientes en el contexto español." Scripta Nova. Revista electrónica de Geografía y Ciencias Sociales 299, no. XII (2009).Fernández, Ignacio. "Los Cerros Islas como Hábitats de Fauna y Generadores de Servicios Ambientales para la Ciudad de Santiago de Chile." Revista Conservación Ambiental 1 (2011): 9-15.GLA. Greater London Authority. "Green infrastructure and open environments: the All London Green Grid." accessed November 4, 2019. https://www.london.gov.uk/whatwe-do/environment/parks-green-spaces-and-biodiversity/all-london-green-gridGobierno Regional Metropolitano de Santiago. "Política Regional de Áreas Verdes." accessed December 12 , 2019. https://www.gobiernosantiago.cl/wp-content/uploads/2014/doc/estrategia/Politica_Regional_de_Areas_Verdes,_2014.pdfHansen Rieke and Pauleit, Stephan. "From multifunctionality to multiple ecosystem services? A Conceptual framework for multifunctionality in green infrastructure planning for urban areas." Ambio 43, no. 4 (2014): 516-529. https://doi.org/10.1007/s13280-014-0510-2INE. Statistics National Institute. Censo Nacional de Población y de Vivienda. Chile. 2017INE. Statistics National Institute. "Sistema de Indicadores y Estándares del Desarrollo Urbano (SIEDU)." accessed January 6, 2020. http://siedu.ine.cl/index.html.López Varela, Susana. "El Green Belt en Inglaterra: de la contención edilicia al valor del paisaje." PhD diss., Universitat Politècnica de Catalunya, 2013.LUC. Land Use Consultants. "Green Infrastructure Guidance." accessed October 21, 2019. http://publications.naturalengland.org.uk/publication/35033.Mallarach, Josep Maria and Joan Marull. "La Conectividad Ecológica en la planificación y la evaluación estratégica: aplicaciones en el área metropolitana de Barcelona." Ciudad y territorio: Estudios Territoriales 147 (2006): 41-60.MEA. Millenium Ecosystem Assessment. Ecosystem and Human Well-being: Current State and Trends. Washington: Island Press, 2005.Mell, Ian C.. "Can green infrastructure promote urban sustainability?" Engineering Sustainability 162 (2009): 23-34. https://doi.org/10.1680/ensu.2009.162.1.23Ministry of Interior and Public Safety. "Diario Oficial de la República de Chile, Nº 42.479, CVE 1668799. Jueves 17 de octubre." accessed January 6, 2020. https://www.diariooficial.interior.gob.cl/publicaciones/2019/10/17/42479/01/1668799.pdf.MMA. Ministerio del Medio Ambiente. "Resumen diagnóstico ambiental. Recursos hídricos en la Región Metropolitana de Santiago." accessed October 15, 2019. http://metadatos.mma.gob.cl/sinia/articles-39509_pdf_agua.pdf.Montaner, Josep Maria. "El modelo Curitiba: movilidad y espacios verdes." Ecología Política 17 (1999): 69-71.Montoya-Tangarife, Claudia, Francisco De La Barrera, Alejandro Salazar and Luis Inostroza. "Monitoring the effects of land cover change on the supply of ecosystem services in an urban region: A study of Santiago- Valparaíso, Chile." PLoS ONE 12, no. 11 (2017). https://doi.org/10.1371/journal.pone.0188117MPRMS-100. Modification number 100 to the Santiago Metropolitan Regulatory Plan. November 2013.ODEPA. Oficina de Estudios y Políticas Agrarias. "Impacto de la expansión urbana sobre el sector agrícola en la Región Metropolitana de Santiago." Accessed December 7, 2019. https://www.odepa.gob.cl/publicaciones/documentos-einformes/estudio-impacto-de-la-expansion-urbana-sobre-el-sector-agricola-en-laregion-metropolitana-de-santiagoOlivares, Elisabet. "Plan de Espacios Abiertos e Infraestructura Ecológica en Lima. Una apuesta por el territorio en una ciudad fragmentada." Planur-e 10 (2017).PRC San Bernardo. Communal Regulatory Plan of San Bernardo and the locality of Lo Herrera. Local ordinance, May 2006.PRMS. Santiago Metropolitan Regulatory Plan. Ordinance, October 2007.Regional Metropolitan Government of Santiago. "Green Areas Regional Policy." accessed December 12 , 2019. https://www.gobiernosantiago.cl/wp-content/uploads/2014/doc/estrategia/Politica_Regional_de_Areas_Verdes,_2014.pdf.Reyes, Sonia e Isabel Margarita Figueroa. "Distribución, superficie y accesibilidad de las áreas verdes en Santiago de Chile." EURE, Revista de Estudios Urbanos Regionales 109 (2010): 89-110. https://doi.org/10.4067/S0250-71612010000300004Riedel, Tomás. Aprobación PRMS-100; análisis y alcances. Santiago de Chile: Cámara Chilena de la Construcción, CCHC, 2014.Rojas, Carolina, Joan Pino and Edilia Jaque. "Strategic Environmental Assessment in Latin America: A methodological proposal for urban planning in the Metropolitan Area of Concepción (Chile)." Land Use Policy 30, no. 1 (2013): 519-527. https://doi.org/10.1016/j.landusepol.2012.04.018Romero Aravena, Hugo and Alexis Vásquez. "Evaluación ambiental del proceso de urbanización de las cuencas del piedemonte andino de Santiago de Chile." EURE, Revista de Estudios Urbano Regionales 94 (2005): 97-118. https://doi.org/10.4067/S0250-71612005009400006Romero Aravena, Hugo, Claudio Fuentes and Pamela Smith. "Ecología política de los riesgos naturales y de la contaminación ambiental en Santiago de Chile: necesidad de justicia ambiental." Scripta Nova. 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Revista de geografía Norte Grande 63 (2016): 65. https://doi.org/10.4067/S0718-34022016000100005United Nations. "New Urban Agenda. Habitat III Conference." accessed January 8, 2020. http://habitat3.org/wp-content/uploads/NUA-Spanish.pdfUnited Nations. "2018 Revision of world urbanization prospects." accessed January 6, 2020. https://population.un.org/wup

Photochemical cross-linking study of polymers containing diacetylene groups in their main chain and azobenzene compounds as pendant groups

Photochemical cross-linking studies at different temperatures (room temperature, Tg and maximum exothermal of crosslinking peak) are shown for three series of polymers containing diacetylene-groups in the main chain and polar chromophores derived from benzene, azo- and di-azobenzene, as pendant groups. We establish the optimal irradiation time and temperature that permit them being poled and cross-linked with minimal dye-degradation. The degradation process was followed by a diminution of the respective maximum absorption peak. These conditions could extend the mean life-time of the second order nonlinear optical properties, studied previously. Photochemical cross-linking at each polymer´s Tg (50-130°C) was the most convenient process. It took less than 10 min and was monitored by IR spectroscop

Relationship between Polymer Dielectric Constant and Percolation Threshold in Conductive Poly(styrene)-Type Polymer and Carbon Black Composites

Se presenta un criterio fenomenológico para determinar el umbral de percolación en compuestos poliméricos polímero - negro de carbono, en términos de la constante dieléctrica del polímeroSIE

Conductive Polymeric Composites Based on Multiwalled Carbon Nanotubes and Linseed Oil Functionalized and Cross-Linked with Diacetylenes from Propargyl Alcohol

Apoyo a Consolidadión de Cuerpos AcadémicosSe presenta la síntesis y saracterización de compuestos poliméricos a base de nanotubos de carbono con aceite de linaza epoxidadoPRODEP-SE

Waste and recycling materials used in concrete

Materials with higher strength and high performanceprovide excellent benefits. But after a very short useful-life become waste and contribute to environmental degradation. Some investigations are focused on recycling by using innovative and clean technologies. In this work, waste and recycled materials as well as gamma radiation are proposed as tools for improving mechanical properties of concrete; polyethylene terephthalate of bottles, automotive tire rubber as well as cellulose of Tetra Pak packages are studied as materials.Autonomous University of the State of Mexico (UAEM), Grant 3886/2015F