714 research outputs found
Hilbert Lattice Equations
There are five known classes of lattice equations that hold in every infinite
dimensional Hilbert space underlying quantum systems: generalised
orthoarguesian, Mayet's E_A, Godowski, Mayet-Godowski, and Mayet's E equations.
We obtain a result which opens a possibility that the first two classes
coincide. We devise new algorithms to generate Mayet-Godowski equations that
allow us to prove that the fourth class properly includes the third. An open
problem related to the last class is answered. Finally, we show some new
results on the Godowski lattices characterising the third class of equations.Comment: 24 pages, 3 figure
Directional Detection of Dark Matter with MIMAC
Directional detection is a promising search strategy to discover galactic
Dark Matter. We present a Bayesian analysis framework dedicated to Dark Matter
phenomenology using directional detection. The interest of directional
detection as a powerful tool to set exclusion limits, to authentify a Dark
Matter detection or to constrain the Dark Matter properties, both from particle
physics and galactic halo physics, will be demonstrated. However, such results
need highly accurate track reconstruction which should be reachable by the
MIMAC detector using a dedicated readout combined with a likelihood analysis of
recoiling nuclei.Comment: 4 pages, 2 figures, to appear in the proceedings of the TAUP 2011
conference held in Munich (5 - 9 September, 2011
Agroforestry farming practices of smallholders in Leyte and implications for agroforestry systems design
This paper examines evidence from the Leyte Island smallholder socio-economic survey, on the agroforestry systems adopted by smallholders in terms of timber trees and other crops. A number of broad categories of agroforestry systems may be identified, in terms of smallholders growing various tree and crop species and raising livestock on the same land parcels. However, there do not appear to be any favoured and widely adopted species mixtures with particularly high performance that could be rolled-out more widely. Also, at a land-use block level, survey data provides little evidence of widely-adopted specific agroforestry systems
Smallholder tree growing and timber marketing practices on Leyte Island
This paper reports the results of an analysis of part of the data from a socio-economic survey conducted in seven randomly selected municipalities in Leyte and Southern Leyte Province in the Philippines. It focuses on the management of smallholder tree farmers as well as their experiences in timber selling, and their technical knowledge. The survey examined the intentions and aspirations of smallholders with regard to adopting tree farming on Leyte Island. It was found that most of the respondents relied on their own knowledge and experience in nursery and plantation establishment and maintenance. More than half the respondents had harvested timber in the last three years. Gmelina and mahogany were the species most often harvested
Low energy measurements with Helium Micromegas micro-TPC
The measurement of the ionization produced by particles in a medium presents
a great interest in several fields from metrology to particule physics and
cosmology. The ionization quenching factor is defined as the fraction of energy
released by ionisation by a recoil in a medium compared with its kinetic
energy. At low energy, in the range of a few keV, the ionization falls rapidly
and systematic measurement are needed. We have developped an experimental setup
devoted to the measurement of low energy (keV) ionization quenching factor for
the MIMAC project. The ionization produced in the gas has been measured with a
Micromegas detector filled with Helium gas mixture.Comment: Proceedings of the fourth international symposium on large TPCs for
low energy rare event detection, Paris, France, Dec. 2008 To appear in
Journal of Physic
Sistema innovador de cultivos in vitro inoculados con simbiontes rizosférico MVA y bacterias surfactantes como fitoremediador de suelos contaminados con agrotóxicos
La presente innovación se basa en el empleo de cultivos in vitro, (vitro plantas) con la finalidad de propiciar la fitorremediación de suelos contaminados con agrotóxicos, en particular por el uso mantenido de herbicidas, mediante un sistema compuesto por suelo-plantas inoculadas con simbiontes micorizosférico MVA y bacterias surfactantes. En la investigación, se aplicó el herbicida triazínico ametrina de gran persistencia en el suelo y evaluaron tres especies de MVA: Rhizophagus intrarradices; Glomus. fasciculatum y Fummeliformis moseae inoculadas a plántulas de banano (Musa paradisiaca) clon tetraploide FHIAT comercial 0630 en fase de adaptación, incorporando la bacteria productora de agentes surfactantes Pseudomonas fluorescens cepa PsFS520505. Entre los resultados, se comprobó el alto grado de micorrización alcanzado, superior con R. intrarradices (77%) seguido por G. fasciculatum (67%) y F. mosseae (43%). En cambio, la capacidad fitorremediadora del sistema evaluado en fase de alistamiento, resultó más efectivo con G. fasciculatum (60.7%); seguido por R. intrarradices (51.2 %) y F. mosseae (4.2 %). Se realizó la extensión en campo con la mejor variante integral MVA G. fasciculatum, y P. fluorescens lográndose a los 30 días la biodegradación del 38.4 % de la ametrina residual y el 80 % de sobrevivencia de las plantas lo que le confiere trascendental importancia, al demostrarse una vía agroecológica para la integración de la lucha química y el medio ambiente en el contexto del uso de herbicidas. En campo los resultados duplicaron el efecto fitoremediador del sistema logrando biodegradar el 90% del agrotóxico en un plazo de 60 días
Cerâmicas da Idade do Ferro II do depósito votivo de Garvão
Garvão foi um importante local sagrado da Idade do Ferro II, onde em 1982 foi
acidentalmente descoberto um impressionante depósito votivo [1]. Na escavação foram
recuperados uma enorme variedade de materiais, sobretudo cerâmica, os quais foram
depositados intencionalmente e cuidadosamente organizados de modo a optimizar o espaço
disponível. A cerâmica recuperada mostra que durante a Idade do Ferro este sítio
arqueológico foi um ponto de fusão das sociedades ibéricas com fortes influências celtas
(interior da Península Ibérica) e do mundo Mediterrâneo.
A análise estilística das cerâmicas permitiu a classificação do conjunto cerâmico em
diferentes grupos tipológicos. Relacionando o estudo material com aspectos geológicos
pretende-se contribuir para uma melhor compreensão das sociedades que produziram estas
cerâmicas e das suas interacções no SW da Península durante a Idade do Ferro II. Deste
modo, estabeleceu-se uma metodologia de estudo multi-analítica. Aplicando técnicas
modernas das ciências dos materiais e os princípios da ciências físicas (por exemplo,
geologia e química) pode-se obter respostas e uma melhor compreensão da importância de
Garvão nesta área da Península Ibérica. A combinação de técnicas como microscopia
electrónica com possibilidade de análise elementar, difracção de raios-X e análise térmica
permitem identificar a composição mineralógica destas cerâmicas que extrapolada para a
geologia regional, permitem importantes contributos para o conhecimento das sociedades
que produziram estes materiais de uso comum. Especial ênfase é concedida à fonte de
proveniência das matérias-primas, aos aspectos tecnológicos e, às rotas de circulação de
mercadorias, ideias e crenças religiosas.
Os primeiros resultados [2] são sobre um grupo de cerâmicas em que foram utilizados dois
tipos de matérias-primas: um núcleo inicial com desengordurantes mais grosseiros e a
construção da peça com material mais fino.
[1] C. Beirão et al., O Arqueólogo Português, 3 (1985) 45-136
[2] L. Rosado et al. In IMA2010, Bonds and Bridges: Mineral sciences and their applications, Budapeste (2010),Livro de Resumos. p. 122
Agradecimentos. Este trabalho é financiado pela FCT através do projecto GODESS e da bolsa de
Doutoramento SFRH/BD/67093/2009. Os autores agradecem o apoio da Câmara Municipal de Ourique
Micromegas micro-TPC for direct Dark Matter search with MIMAC
The MIMAC project is a multi-chamber detector for Dark Matter search, aiming
at measuring both track and ionization with a matrix of micromegas micro-TPC
filled with He3 and CF4. Recent experimental results on the first measurements
of the Helium quenching factor at low energy (1 keV recoil) are presented,
together with the first simulation of the track reconstruction. Recontruction
of track of alpha from Radon impurities is shown as a first proof of concept.Comment: 5 pages, Proc. of the fourth international symposium on large TPCs
for low energy rare event detection, Paris, France, Dec. 2008. To appear in
Journal of Physic
Iron age pottery from Garvão votive deposit
The Iberian Peninsula was an attractive area in ancient times due to its abundance in geological resources. Hence, the Iberian Iron Age is a period of successive social and political transformations, sometimes resulting in conflicts [1]. In 1982, an impressive votive deposit was discovered in Garvão (SW Portugal) revealing an important Iron Age II holy site [2]. Beside some uncertainties, this region is marked by very strong Mediterranean cultural influence but the inhabitants are celtic. The materials recovered (mainly pottery) were intentionally deposited, carefully arranged in order to optimize the available space [2, 3]. The pottery recovered shows that during Iron Age this archeological site was a merging geostrategic point of the Iberian societies with strong influences of the Mediterranean world and the Iberia celtic influences.
Pottery fragments are one of the most common signs of human occupation. Its aesthetic aspects are extensively studied as one of mankind’s earliest expressions of representational art. But the ceramic characteristics depend also on the technology accessibility, the relationship of the societies with their environment, especially with the availability of raw materials, and on the commercial and cultural connections with other societies [4, 5]. Raw materials used by these communities provide essential information to understand specific historical periods. The geological resources are particularly useful for this purpose because even processed they can figure out identifiable signatures of provenance or technology used. Moreover, their intermittent occurrence and human necessity justify the existence of trade routes.
A detailed study of the pottery based on stylistic analysis was envisaged which allowed the classification into different clusters. Special emphasis will be given to the provenance of the pottery, the technological aspects and the relationship between populations and Garvão holy site. The study of geological raw materials applying and combining modern techniques of earth materials sciences and the principles of physical sciences (e.g. geology and chemistry) can provide answers and a better understanding of the Garvão importance in this area of the Iberian Peninsula. A multi-analytical methodology was setup using optical and electron microscopy, infrared spectroscopy, X-ray fluorescence and X-ray diffraction. The combination of these techniques applied to selected Garvão pottery materials allowed the recognition of the ceramic phase composition, firing temperature, kiln atmosphere, ceramic manufacturing processes and origin of raw materials. With this study, connections with Mediterranean areas and with local production areas were underlined revealing that Garvão was a multicultural area.
References
[1] Alfenin, R. & Pariera, R.: Taller Poliorcética, Conclusiones, in “Poliorcética, Fortificación y Patrimonio (Asalto y Defensa de Plazas Fuertes)”, Editorial Universidad Politécnica de Valencia, pp. 307-322, 2005.
[2] Beirão, C. de M., Tavares, C., Soares, J., Varela, M. and Varela, R.: Depósito votivo da II Idade do Ferro de Garvão. Notícia da primeira campanha de escavações, O Arqueólogo Português, 3, 45-136, 1985.
[3] Beirão, C. de M., Tavares, C., Soares, J., Gomes, M. and Varela, R.: Um depósito votivo da II Idade do Ferro, no sul de Portugal, e as suas relações com as culturas da Meseta, Veleia, 2-3, 2017-221, 1985-86.
[4] Maggetti, M. & Galetti, G.: Late La Téne pottery from western Switzerland: one regional or several local workshops? in Maggetti, M. & Messiga, B. (eds) “Geomaterials in Cultural Heritage”. Geological Society, London, Special Publications, 257, 63-80, 2009.
[5] Arnold, D.: Linking society with the compositional analyses of pottery: a model from comparative ethnography. in: Livingstone Smith, A., Bosquet, D. & Marttineau, R. (eds) “Pottery Manufacturing Process: Reconstitution and Interpretation”. British Archaeological Reports International Series. Archaeopress, Oxford, 1349, 1-12, 2001.
Acknowledgments
This work was financial supported by “Fundação para a Ciência e Tecnologia” (FCT) through the project PTDC/HIS-ARQ/108758/2008 and the PhD grant SFRH/BD/67093/2009
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