2,490 research outputs found

    Aplicaciones de la digitalización 3D del patrimonio

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    [ES] La digitalización 3D se ha convertido en un herramienta habitual en arqueología. No obstante, el procesamiento de los datos generados por los escáneres láser sigue siendo complejo, y la utilidad dada a los modelos obtenidos es aún muy limitada.En este trabajo analizamos algunos de los puntos más conflictivos en el procesamiento de las nubes de puntos, revisamos algunas de las aplicaciones usuales de los modelos digitales y proponemos un marco conceptual para la utilización de los modelos 3D en la documentación arqueológica.[EN] 3D digitalization has become a common tool in archaeology. However, the post processing of the data produced by the scanners is still quite complex, and the computer models generated are given very few practical applications.In this paper, we analyse the key steps involved in the processing of the point clouds. We also review some of the more usual applications for the digital models and propose a conceptual framework for the use of this models in the documentation of cultural heritage.Ministerio de Ciencia y Tecnología y los fondos FEDER (TIN2007-67474-C03-02), Consejería de Innovación Ciencia y Empresa, Junta de Andalucía ( TIC-401.)Torres, JC.; Cano, P.; Melero, J.; España, M.; Moreno, J. (2010). Aplicaciones de la digitalización 3D del patrimonio. Virtual Archaeology Review. 1(1):51-54. https://doi.org/10.4995/var.2010.4768OJS515411AGNELLO, F. et al. (2003): Cultural heritage and information systems, an investigation into a dedicated hypertext. The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol. 34, Part 5.BESORA, I. et al.(2008): "Real-Time Exploration of the Virtual Reconstruction of the Entrance of the Ripoll Monastery", en Actas del XIX Congreso Español de Informática Gráfica CEIG'08.CALLIERI, M. et al.(2008):Virtual Inspector: "A Flexible Visualizer for Dense 3D Scanned Models". IEEE Computer Graphics and Applications, vol. 28, no.1, pp. 44-54 http://dx.doi.org/10.1109/MCG.2008.20GRANDE LEON, A. (2002): "Italica virtual. Un proyecto educativo que hace Historia", en PH Boletín del Instituto Andaluz del Patrimonio Histórico, no 40/41, pp. 241-247.HODAČ J. (2005): 3D Information System of Historical Site - Proposal and Realisation of a Functional Prototype. Acta Polytechnica. Vol. 45 No. 1IOANNIDIS, C. et al. (2003): An integrated spatial information system for the development of the archaeological site of mycenae. International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol. 34, Part 5.LAMOLDA F. et al. (2008): "Registro mediante la utilizacion de escaner 3D del estado previo a la intervencion de la Fuente de los Leones". Taller en el IX Congreso Internacional de Rehabilitación del Patrimonio Arquitectónico y Edificación, Sevilla.MELERO J. et al. (2005): "Combining SP-octrees and impostors for the visualisation of multiresolution models". Computer & Graphics, vol. 29, pp: 225-233 http://dx.doi.org/10.1016/j.cag.2004.12.008MEYER, E. et al. (2006): "Intra-site Level Cultural Heritage Documentation: Combination of Survey, Modeling and Imagery Data in a Web Information System". 7th International Symposium on Virtual Reality, Archaeology and Cultural Heritage. VAST.NAGLIČ K.K. (2003): "Cultural Heritage Information System in The Republic of Slovenia". ARIADNE 5 Workshop on Documentation, Interpretation, Presentation and Publication of Cultural Heritage. Prague.PAPAGIANNAKIS, G. et al. (2005): "Mixing Virtual and Real scenes in the site of ancient Pompeii". Computer Animation and Virtual Worlds, 16(1), 11-24. http://dx.doi.org/10.1002/cav.53OKAMOTO, Y.,(2008): "Editing, Retrieval, and Display System of Archeological Information on Large 3D Geometric Models". Digitally Archiving Cultural Objects, chapter 21 http://dx.doi.org/10.1007/978-0-387-75807_21SCOPIGNO R. et al. (2003): "Using optically scanned 3D data in the restoration of Michelangelo's David. Optical Metrology for Arts and Multimedia". Proceedings of the SPIE, Vol. 5146, pp. 44-53 http://dx.doi.org/10.1117/12.49992

    Band-gap engineering of Cu2ZnSn1-xGe xS4 single crystals and influence of the surface properties

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    Thin film solar cells based on Cu2ZnSn(S,Se)4 are very promising, because they contain earth-abundant elements and show high absorptivity. However, the performance of these solar cells needs to be improved in order to reach efficiencies as high as that reported for Cu(In,Ga)Se 2-based devices. This study investigates the potential of band-gap engineering of Cu2ZnSn1-xGexS 4 single crystals grown by chemical vapour transport as a function of the [Ge]/([Sn] + [Ge]) atomic ratio. The fundamental band gap E0 is found to change from 1.59 to 1.94 eV when the Ge content is increased from x = 0.1 to x = 0.5, as determined from spectroscopic ellipsometry measurements. This knowledge opens a route to enhancing the performance of kesterite-based photovoltaic devices by a Ge-graded absorber layer. Furthermore, the formation of GeO2 on the surface of the as-grown samples was detected by X-ray photoelectron spectroscopy, having an important impact on the effective optical response of the material. This should be also taken into account when designing photovoltaic solar cellsRC acknowledges financial support from Spanish MINECO within the program Ramón y Cajal (RYC-2011-08521). This work was supported by the Marie Curie-IRSES project (PVICOKEST, GA: 269167), MINECO projects (KEST-PV, ENE2010-21541-C03-01/-02/-03) and Marie Curie-ITN project (KESTCELL, GA: 316488

    Fracturas del macizo trocantéreo. Estudio comparativo Ender-DHS: revision de 114 casos

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    Se presenta un estudio retrospectivo de 114 fracturas pertrocantéreas tratadas con enclavado elástico de Ender (71) y tornillo placa deslizante, DHS (43). Se efectuó un estudio estadístico descriptivo-comparativo entre los 2 grupos de pacientes según la técnica quirúrgica empleada. Se constató un mayor índice de estabilidad usando el DHS (81%), frente al 6 1 % del otro grupo. La tasa de complicaciones fue del 16% y 55% respectivamente. Los resultados clínicos fueron mejores en los enfermos tratados con DHS, fundamentalmente en cuanto a la deambulación que se consiguió en el 98% (Ender 75%), ausencia de dolor y movilidad conservada. Los autores piensan que la estabilidad preoperatoria no influye en la solidez del montaje usando el DHS, pero con la técnica de Ender ésta disminuye en las fracturas inestables; por ello, la técnica de Ender estaría solamente indicada en el tratamiento de fracturas estables en pacientes de edad avanzada o con mal estado general, aunque en clara competencia con el DHS.A retrospective study of 114 intertrochanteric fractures operated on either with Ender's rods (71) or dynamic hip screws, DHS (43) is presented. A statistical descriptive-comparative study between the 2 groups was attempted. There was a greater index of stability using the DHS (82%) than Ender's rods (61%). The rate of complications was 16% and 55% respectively. The clinical outcome was better in cases treated with DHS, specially for walking ability, which was regained in the 98% of cases (Ender 75%), painless and preserved mobility. The authors think that the stability before operation do not influence the solidity of the assembly using the DHS device. On the contrary, with the Ender's technique the fixation is no satisfactory in unstables fractures. Ender's rods would only be suitable for treatment of stable fractures in older patient or with serious associated diseases, although in clear competition with the DHS

    Microbial Communities in Pre-Columbian Coprolites

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    The study of coprolites from earlier cultures represents a great opportunity to study an “unaltered” composition of the intestinal microbiota. To test this, pre-Columbian coprolites from two cultures, the Huecoid and Saladoid, were evaluated for the presence of DNA, proteins and lipids by cytochemical staining, human and/or dog-specific Bacteroides spp. by PCR, as well as bacteria, fungi and archaea using Terminal Restriction Fragment analyses. DNA, proteins and lipids, and human-specific Bacteroides DNA were detected in all coprolites. Multidimensional scaling analyses resulted in spatial arrangements of microbial profiles by culture, further supported by cluster analysis and ANOSIM. Differences between the microbial communities were positively correlated with culture, and SIMPER analysis indicated 68.8% dissimilarity between the Huecoid and Saladoid. Proteobacteria, Bacteroidetes and methanogens were found in all coprolite samples. Propionebacteria, Shewanella and lactic acid bacteria dominated in the Huecoid samples, while Acidobacteria, and peptococci were dominant in Saladoid samples. Yeasts, including Candida albicans and Crypotococcus spp. were found in all samples. Basidiomycetes were the most notable fungi in Huecoid samples while Ascomycetes predominated in Saladoid samples, suggesting differences in dietary habits. Our study provides an approach for the study of the microbial communities of coprolite samples from various cultures

    Towards the growth of Cu2ZnSn1-xGexS4 thin films by a single-stage process: Effect of substrate temperature and composition

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    Cu2ZnSn1-xGexS4 (CZTGS) thin films prepared by flash evaporation of a Zn-rich Cu2ZnSn0.5Ge0.5S4 bulk compound in powder form, and a subsequent thermal annealing in S containing Ar atmosphere are studied. The effect of the substrate temperature during evaporation and the initial composition of the precursor powder on the growth mechanism and properties of the final CZTGS thin film are investigated. The microstructure of the films and elemental depth profiles depend strongly on the growth conditions used. Incorporation of Ge into the Cu2ZnSnS4 lattice is demonstrated by the shift of the relevant X-ray diffraction peaks and Raman vibrational modes towards higher diffraction angles and frequencies respectively. A Raman mode at around 348-351 cm-1 is identified as characteristic of CZTGS alloys for x = [Ge]/([Sn]+[Ge]) = 0.14-0.30. The supply of Ge enables the reduction of the Sn loss via a saccrifical Ge loss. This fact allows increasing the substrate temperature up to 350º C during the evaporation, forming a high quality kesterite material and therefore, reducing the deposition process to one single stageRC acknowledges financial support from Spanish MINECO within the Ramón y Cajal programme (RYC-2011-08521) and VIR for the Juan de la Cierva fellowship (JCI-2011-10782). GB also acknowledges the CSIC-JAE pre-doctoral program, co-funded by the European Social Fund. This work was supported by the Marie Curie-IRSES project (PVICOKEST, GA: 269167), Marie Curie-ITN project (KESTCELL, GA: 316488), DAAD project (INTERKEST, Ref: 57050358), and MINECO projects (SUNBEAM, ENE2013-49136-C4-3-R) (TEC2012-38901-C02-01). A. Scheu is acknowledged for GDOES measurement

    Towards the growth of Cu2ZnSn1 xGexS4 thin films by a single stage process Effect of substrate temperature and composition

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    Cu2ZnSn1-xGexS4 (CZTGS) thin films prepared by flash evaporation of a Zn-rich Cu2ZnSn0.5Ge0.5S4 bulk compound in powder form, and a subsequent thermal annealing in S containing Ar atmosphere are studied. The effect of the substrate temperature during evaporation and the initial composition of the precursor powder on the growth mechanism and properties of the final CZTGS thin film are investigated. The microstructure of the films and elemental depth profiles depend strongly on the growth conditions used. Incorporation of Ge into the Cu2ZnSnS4 lattice is demonstrated by the shift of the relevant X-ray diffraction peaks and Raman vibrational modes towards higher diffraction angles and frequencies respectively. A Raman mode at around 348-351 cm-1 is identified as characteristic of CZTGS alloys for x = [Ge]/([Sn]+[Ge]) = 0.14-0.30. The supply of Ge enables the reduction of the Sn loss via a saccrifical Ge loss. This fact allows increasing the substrate temperature up to 350º C during the evaporation, forming a high quality kesterite material and therefore, reducing the deposition process to one single stageRC acknowledges financial support from Spanish MINECO within the Ramón y Cajal programme (RYC-2011-08521) and VIR for the Juan de la Cierva fellowship (JCI-2011-10782). GB also acknowledges the CSIC-JAE pre-doctoral program, co-funded by the European Social Fund. This work was supported by the Marie Curie-IRSES project (PVICOKEST, GA: 269167), Marie Curie-ITN project (KESTCELL, GA: 316488), DAAD project (INTERKEST, Ref: 57050358), and MINECO projects (SUNBEAM, ENE2013-49136-C4-3-R) (TEC2012-38901-C02-01). A. Scheu is acknowledged for GDOES measurement

    Towards the growth of Cu2ZnSn1 xGexS4 thin films by a single-stage process: Effect of substrate temperature and composition

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    9 págs.; 7 figs.; 2 tabs.Cu2ZnSn1-xGexS4 (CZTGS) thin films prepared by flash evaporation of a Zn-rich Cu2ZnSn0.5Ge0.5S4 bulk compound in powder form, and a subsequent thermal annealing in S containing Ar atmosphere are studied. The effect of the substrate temperature during evaporation and the initial composition of the precursor powder on the growth mechanism and properties of the final CZTGS thin film are investigated. The microstructure of the films and elemental depth profiles depend strongly on the growth conditions used. Incorporation of Ge into the Cu2ZnSnS4 lattice is demonstrated by the shift of the relevant X-ray diffraction peaks and Raman vibrational modes towards higher diffraction angles and frequencies respectively. A Raman mode at around 348-351 cm-1 is identified as characteristic of CZTGS alloys for x = [Ge]/([Sn]+[Ge]) = 0.14-0.30. The supply of Ge enables the reduction of the Sn loss via a saccrifical Ge loss. This fact allows increasing the substrate temperature up to 350º C during the evaporation, forming a high quality kesterite material and therefore, reducing the deposition process to one single stage & 2015 Elsevier B.V. All rights reserved.RC acknowledges financial support from Spanish MINECO within the Ramón y Cajal programme (RYC-2011-08521) and VIR for the Juan de la Cierva fellowship (JCI-2011-10782). GB also acknowledges the CSIC-JAE Pre-doctoral Program, co-funded by the European Social Fund. This work was supported by the Marie Curie-IRSES Project (PVICOKEST, GA: 269167), Marie Curie-ITN project (KESTCELL, GA: 316488), DAAD project (INTERKEST, Ref: 57050358), and MINECO projects (SUNBEAM, ENE2013-49136-C4-3-R) (TEC2012- 38901-C02-01). A. Scheu is acknowledged for GDOES measurements.Peer Reviewe

    A study of the dry forest communities in the Dominican Republic

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    This paper is a floristic and phytosociological study of the dry forest communities of the Dominican Republic. A total of 69 relevés in dry forest biotopes were carried out. The samples were subsequently subjected to Detrended Correspondence Analysis for the determination and study of possible groupings. The study does not cover tree formations growing on serpentines, nor the so-called semideciduous forests, peculiar to areas with higher rainfall. A total of nine phytocoenoses were identified. The most significant results led to the description of six new phytosociological associations: Simaroubetum berteroani (thorny dry forest on coastal dunes), Phyllostylo rhamnoidis-Prosopidetum juliflorae (southern Dominican disturbed dry forest), Consoleo moniliformis-Camerarietum linearifoliae (dry forest on hard limestones), Lemaireocereo hystricis-Prosopidetum juliflorae (northern Dominican disturbed dry forest), Lycio americani-Prosopidetum juliflorae (disturbed dry forest on saline soils) and Guettardo ellipticae-Guapiretum discoloris (dry forest on flat-topped hillocks in Montecristi). This is an important step forward in the phytosociological and floristic studies of the Caribbean territories.Este trabalho apresenta um estudo florístico e fitossociológico das comunidades de florestas secas da República Dominicana. Um total de 69 amostras foram obtidas pelo método relevé em biótopos florestais secos. As amostras foram posteriormente submetidas à análise de correspondência destendenciada para a determinação e estudo de possíveis agrupamentos. O estudo não abrange formações arbóreas desenvolvidas sobre serpentinitos, nem as chamadas florestas semideciduais, peculiares às áreas de maior pluviosidade. Foram identificados nove fitocenoses. Os resultados mais significativos levaram à descrição de seis novas associações fitossociológicas: Simaroubetum berteroani (floresta espinhosa seca em dunas costeiras), Phyllostylo rhamnoidis-Prosopidetum juliflorae (floresta seca perturbada do sul da República Dominicana), Consoleo moniliformis-Camerarietum linearifoliae (floresta seca sobre calcários compactos), Lemaireocereo hystricis-Prosopidetum juliflorae (floresta seca perturbada do norte da República Dominicana), Lycio americani-Prosopidetum juliflorae (floresta seca perturbada desenvolvida em solos salinos) Guettardo ellipticae-Guapiretum discoloris (floresta seca em colinas de topo achatado em Montecristi). O trabalho realizado representa um importante avanço nos estudos fitossociológicos e florísticos dos territórios do Caribe.This research paper was possible thanks to the sponsorship of the Agencia Española de Cooperación Internacional para el Desarrollo (AECID), under the auspices of the Ministerio de Asuntos Exteriores y de Cooperación de España, which funded the project (cod. A/3499/05)
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