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\n 20_P-XRF<\/b> \/ CARACTERIZAÇÃO DE UMA MOEDA ROMANA POR EDXRF E MICRO CT\n <\/div>\n
\n LICIANE PLOUVIER\n <\/div>\n <\/div>\n
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\n A utilização de técnicas não destrutivas na análise de material arqueológico é recomendada a fim de garantir sua preservação. Neste estudo foi analisada uma moeda do Império Romano datada do século IV D.C. do governo de Constantine II. Sua composição química superficial foi obtida de forma qualitativa através da técnica de Fluorescência de Raios X por Energia Dispersiva (EDXRF) e a homogeneidade da liga foi avaliada por Microtomografia Computadorizada (µ-CT). A leitura por EDXRF em três pontos distintos da moeda é apresentado na Tabela 1. É possível perceber um aumento da quantidade de prata e chumbo no ponto b em relação aos outros pontos medidos. A µ-CT revelou uma variação de densidade na superfície da moeda, especialmente na região do ponto b, como pode ser observado na Figura 1. Estes resultados são compatíveis com o processo térmico\/mecânico conhecido como enriquecimento superficial de prata, que promove a migração destes metais para a superfície e confere um brilho prateado à moeda.\n <\/div>\n <\/div>\n<\/div>\n
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\n 17_P-XRF<\/b> \/ COMPOSIÇÃO QUÍMICA INORGÂNICA DE OTÓLITOS DE PESCADA BRANCA (Plagioscion squamosissimus) PELO MÉTODO DE FLUORESCÊNCIA DE RAIOS-X POR DISPERSÃO DE ONDAS\n <\/div>\n
\n Hugo Rafael do Amaral Carvalho\n <\/div>\n <\/div>\n
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\n A espécie Plagioscion squamosissimus, pertence à família Scianidae, conhecida popularmente como corvina ou pescada branca, sendo originária da bacia amazônica e amplamente comercializada nas regiões norte e nordeste do Brasil. Alimenta-se de peixes menores e camarões. Como peixe ósseo possui três pares de corpos inorgânicos chamados otólitos, cada par tendo um nome especifico. São eles: sagittae, lapillus e asteriscus, sendo o sagittae, em várias espécies, mais notório em dimensão e objeto de vários estudos. Otólitos são concreções calcárias em volta de uma matriz protéica, presentes no ouvido dos peixes ósseos (atrás dos olhos), com funções específicas de equilíbrio, sentido de direção e receptor de vibrações sonoras. Nele está contida informações da idade, crescimento, local de nascimento, padrões migratórios, determinação de eventos importantes no ciclo de vida do peixe. Com a determinação química inorgânica do otólito é possível saber como o peixe está interagindo com o meio, uma vez que biomineraliza os minerais que consome por meio de sua alimentação. Os otólitos utilizados para análise foram retirados de exemplares coletados na região pesqueira de Manacapuru, interior do Amazonas, Baixo Solimões, os mesmos triturados e aglutinados em pastilhas de ácido bórico para análise qualitativa e quantitativa no equipamento de fluorescência de raios-x por dispersão de ondas. Os elementos encontrados nas amostras foram Ca, Na, Al, Si, P, S, Cl, K, Fe, Sr, Ag, Rb e Mo, sendo o cálcio presente em maior quantidade, uma vez que os otólitos são concreções calcárias sob a forma mineral de aragonita.\n <\/div>\n <\/div>\n<\/div>\n
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\n 13_P-XRD<\/b> \/ CORE-LEVEL RIXS AS A TOOL FOR ANALYZE CHARGE-RELATED VARIATIONS ON THE LI4TI5O12 COMPOUND\n <\/div>\n
\n Juan José Leani\n <\/div>\n <\/div>\n
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\n Nowadays, renewable energy resources as well as more efficient energy storage systems have taken a starring role, since more sustainable energy systems are being demanded due mainly to the increasing needs of modern society together with the collateral effects of conventional energy sources. This situation has driven to a search for improved electrochemical storage systems that can safely store energy from sustainable sources, proving the energy needed, for example, for transportation and residential uses.\r\nAs an example of everyday technology, the use of portable electronic devices has been feasible thanks to the lithium-ion batteries (LIB). The energy storage capacity of the LIB system is 5 times higher than lead-acid batteries, and it shows an average voltage of 3.8 V per cell in comparison with the average 2.0-2.2 V of the lead-acid batteries. In addition, lithium-ion batteries have the advantage of lower weight, higher energy density and faster charge and discharge rates compared to other similar battery technologies.\r\nEven though they are the most widely batteries employed in portable electronics, it is important to attend several issues regarding safety, and to improve its energy storage capacity in order to be used at larger scales, in, for example, electric vehicles. Lithium titanate, Li4Ti5O12 (LTO), is a promising candidate for anode material at the moment because of many its advantages. Due to this, a better knowledge regarding the LTO structure and how changes are related with its ulterior performance is of great importance. \r\nIn this work, Resonant Inelastic X-ray Scattering (RIXS) has been used for studying titanium local environment changes in the LTO molecule when different levels of charge are applied. As complementary technique, XANES spectra of the Ti-K edge were also measured. \r\nThe measurements were carried out at the Brazilian Synchrotron Light Source (LNLS, Campinas) in the D09B beamline and at ELETTRA Sincrotrone Trieste (Italy) in the IAEA end-station of the XRF-beamline. Several samples with different levels of charge (not charged, partially charged and fully charged) were studied. Reflection geometry was used together with monochromatic photons of 4900 eV (just beneath the K absorption edge of titanium) for the RIXS measurements and XANES spectra were acquired scanning the incident beam energy in the range 4930-5080 eV, i.e., around the Ti-K edge. \r\nFor data analysis, and in order to discriminate the changes on the titanium chemical state of the LTO molecule, Principal Component Analysis (PCA) was used on both RIXS and XANES spectra. \r\nThe results show that RIXS allows the detection of minor changes in the structure of the lithium-based compound due to the particular level of charge. In this way, typical chemical studies as the ones performed with conventional absorption techniques (XANES, EXAFS) can be achieved with this technique, with the advantageous characteristics of shorter measuring times and suppressing any energy scan during the analysis, between others.\n <\/div>\n <\/div>\n<\/div>\n
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\n 11_P-XRF<\/b> \/ DETERMINAÇÃO DE ESPESSURA DE OURO USANDO FLUORESCÊNCIA DE RAIOS X PORTÁTIL E CALIBRAÇÃO MULTIVARIADA \n <\/div>\n
\n Fabio lopes\n <\/div>\n <\/div>\n
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\n Métodos de análise multivariada tais como, PLS tem sido amplamente utilizado em conjunto com outras técnicas analíticas para estudos de objetos arqueológicos e do patrimônio cultural. O procedimento de PLS utilizando compreende duas etapas: a validação e calibração. A etapa de calibração é utilizada para o estabelecimento de uma relação entre a matriz de dados X (sinais instrumentais, variáveis independentes) e as propriedades amostras usando amostras de referência (variáveis dependentes) organizadas na matriz Y. A etapa de validação permite a verificação se o modelo é capaz de prever as propriedades das novas amostras. Foi estudado uma moldura dourada da peça intitulada Mulher Enxugando o Braço Esquerdo (Após o Banho) realizada em 1884, de autoria do pintor Degas, Hilaire-Germain Edgar de Gas com dimensões de 58 x 64 cm. Seis pontos foram analisados por PXRF durante 300 segundos. Para obter os padrões (variáveis dependentes) utilizados no modelo PLS folhas de ouro com espessuras conhecidas foram utilizadas correspondendo aos valores 0,094, 0,188, 0,564, 1,128, 2,068 µm, respectivamente. Para a regressão PLS, os dados dos espectros de calibração foram arranjados em uma matriz 5x1024 (X) e uma matriz de 5x1 (Y) com os valores de espessuras. Os dados de validação foram arranjados em uma matriz 6x1024 (X) com os espectros a partir da moldura. Foi usado um filtro de média como um passo de pré-processamento dos dados, e todos os espectros foram normalizados para o mesmo tempo de medição. A metodologia proposta com base em uma abordagem PLS foi capaz de prever as espessuras de Au numa moldura de madeira dourada de uma pintura. A diferença relativa entre os dois métodos permaneceu entre 6 até 16%, e os valores de espessura podem ser consideradas equivalentes, dentro das barras de erro. \n <\/div>\n <\/div>\n<\/div>\n
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\n 12_P-XRD<\/b> \/ DOSE RATES IN REAL TIME FOR INTERVENTIONAL FLUOROSCOPY PROCEDURES\n <\/div>\n
\n JOSE C C LOURENCO\n <\/div>\n <\/div>\n
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\n In interventional procedures using fluoroscopy, the medical staff is exposed to ionizing radiation, often above the limit allowed to occupationally exposed individuals and are only seen at the end of the procedure or after a month when using individual dosimeters. The aim of this study was to develop a system to estimate the equivalent dose of ionizing radiation in real time during the interventional medical procedure using fluoroscopy. The performance of the remote-controlled fluoroscopy system of scattered radiation measurements was operated at 50 kVp and 30 mA and 9DP model ionization chamber Ludlum and phantom PMMA. Dose rates were collected by the ionization chamber for the regions of the gonads, 90 cm, the trunk 128 cm eyes, 166 cm and the distance of the main beam 19, 38, 76 and 152 cm, alternately turning 45.O and 45.O around the fluoroscopy table. The rates above 10μSv\/h doses and the reproducibility of the measurements were considered. The criterion of Chauvenet was used to eliminate the discrepant results data, and were calculated the mean and standard deviation for each position. The result of this selection was used to construct isodose curves using interpolation techniques. System linearity tests were conducted by varying the voltage obtaining the correlation coefficient of 0.97 and 0.99 respectively for the interventional physician and nurse positions. For viewing in real time dose rates ionization chamber was set at the top of the fluoroscopy table as a fixed reference point. The collected data were sent to the computer to determine the dose rates estimated indirectly in relation to the predetermined isodose and positioning of the medical staff in interventional procedure. Dose rates and the estimated cumulative dose are shown in real time via a TV monitor located visibly showing the intensities of dose rates with a visual indication of color scale to the doses received by members of the medical team. Student's test was used to validate the system with p < 0.05. The exposure of ionizing radiation was reduced when the medical team changed its position or increasing distance in relation to the main beam during the interventional procedure.\n <\/div>\n <\/div>\n<\/div>\n
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\n 44_P-XRF<\/b> \/ ESPECTROMETRO POR FLUORESCENCIA DE RAYOS X PARA ANÁLISIS DE TRAZAS METÁLICAS EN MUESTRAS BIOLÓGICAS\n <\/div>\n
\n Falchini Gisele Evangelina\n <\/div>\n <\/div>\n
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\n La técnica de fluorescencia de rayos X (XRF) permite la identificación y cuantificación de elementos en muestras de diversa naturaleza. En particular su aplicación en tejidos biológicos es ventajosa porque no exige una preparación de muestras compleja en comparación con técnicas instrumentales alternativas. Los estudios por XRF permiten realizar un seguimiento de las concentraciones de elementos metálicos contribuyendo de esta manera al entendimiento de diversos procesos fisiológicos de los organismos vivos donde los metales son partícipes esenciales. Sin embargo, las concentraciones de metales en tejidos biológicos se encuentran en niveles traza por lo que su análisis requiere una cuidadosa optimización de la sensitividad del espectrómetro y del proceso de preparación de muestras.\r\n\r\nEn este trabajo se desarrolló un dispositivo compacto que permita modificar el haz de excitación en energía y tamaño, para esto fue utilizado un cristal de silicio (100) y colimadores de láminas paralelas de vidrio tanto en el canal de excitación como en el canal de detección tanto antes como después del cristal. El dispositivo se acopló a un tubo de rayos X de difracción Philips modelo PW2275\/20 con ánodo de molibdeno de modo de seleccionar la línea Kα de emisión característica. El haz de rayos x de excitación resultante es altamente monocromatizado (\uf044E= 0,8 keV), intenso y con sección transversal de 1mm×3,5mm, permitiendo registrar espectros por XRF con muy baja señal de fondo y alta tasa de conteo, lo cual incrementa considerablemente la sensitividad del espectrómetro. Para alcanzar límites de detección en el orden de las partes por millón, las muestras de tejidos biológicos deben además ser liofilizadas. En el presente trabajo se muestran los resultados de la caracterización del espectrómetro desarrollado (límites de detección, propiedades del haz de excitación) y algunas aplicaciones sobre tejidos biológicos (especialmente tumores malignos de mama).\r\n\n <\/div>\n <\/div>\n<\/div>\n
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\n 12_P-XRF<\/b> \/ PORTABLE X-RAY FLUORESCENCE APPLIED TO MEASUREMENT OF V2O5 NANOMETRIC THIN FILMS\n <\/div>\n
\n Fabio lopes\n <\/div>\n <\/div>\n
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\n Intended primarily for decoration, currently thin films are used as the basis of high technology. Among the physical quantities that characterize it, thickness strongly influences other properties of the film. Thickness measurements are performed using sophisticated and high cost equipment, which often need a proper treatment of the sample to accomplish the desired measurement. Thus, the methodology of X-Ray Fluorescence with portable equipment (PXRF) shows a highly suitable tool to determine these thicknesses. Thus, it was proposed and developed a procedure for the determination of film thickness by PXRF employing K lines attenuation. The thin films were deposited by thermal evaporation from the pellets with 100 mg, 70 mg and 35 mg of V2O5 powder (Sigma-Aldrich, 99.9%). Knowing that Calcium (Ca) is one of the constituents of the glass substrate, it is used the differential attenuation of the K lines of this element after traversing the layer of V2O5. It was employed a Portable X-ray Fluorescence system (PXRF) composed of a Si-Pin detector with a 6 mm2 crystal and 500 μm thickness, a 12.5 μm thickness Beryllium window and a silver anode X-ray tube with silver collimator and filter. Thickness obtained by PXRF was compared with the measurements obtained by scanning electron microscopy. Through the PXRF technique values of 54, 98 and 167 nm for film thicknesses of 35, 70 and 100 mg were obtained. These values are in good agreement with measures by electron microscopy, 50 ± 7, 110 ± 3 and 160 ± 5 nm, respectively. It is observed that the values of the calculated thicknesses are slightly larger than the values measured by the scanning micrographs, due to the fact that a small residual deposits in the boat evaporation. Thus, the PXRF methodology is a highly suitable tool to determine the thickness of nanometric thin.\n <\/div>\n <\/div>\n<\/div>\n
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\n 10_P-XRD<\/b> \/ PRELIMINARY XRF&XRD SCREENING OF METALLIC OBJECTS FOUND IN ARCHAEOLOGICAL EXCAVATIONS AT PYRENEES MOUNTAINS (CATALONIA, NE SPAIN)\n <\/div>\n
\n Ignasi QUERALT\n <\/div>\n <\/div>\n
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\n During the last 20 years the archaeological research in the Oriental Pyrenees, especially in the Cerdanya region (Girona, NE Spain), has evidenced the presence of an important Iron Age population, the Cerretani, mentioned in the ancient literary sources. They occupied the central valleys of the eastern Pyrenees, from the planes (up to 1100 m. asl) to the main hills and the pasture lands (up to 2.000 m. asl). This cerretani were settled in several oppida, the typical Iron age hill forts, of modest dimensions (0,6 Ha.), placed along the course of the Segre river.\r\n\r\nThe main site discovered, the Castellot oppidum (Bolvir), has been excavated in the last ten years, showing the presence of a limited population (about 200-250 people) since the beginning of the 4th c. B.C. The excavations have shown the presence of an Iberian community but with some specificities, like the importance of the livestock strategies or the low presence of imported materials. The recent discovery of several objects in archaeological context in the Oriental Pyrenees (la Cerdanya region, Catalonia) has aroused the question of the Roman presence in this mountain area, and the development of some metallurgical activities in this previously considered marginal zone. \r\n.\r\nAbout the middle half of 2nd c. B.C. these cerretani oppida were remodelled, as we have documented: the setting up of a new urbanism, the opening of a fortified gate, and specially the uses of new metallurgical technologies, show the potential impact of the Roman presence, probably in a military context. Coming from different sites, we have collected some metallurgical objects (earring, rings and coins) that use gold and silver in an elaborated technology, and pointed out the question of the use of gold in pre-Roman and Roman times in this Pyrenean area. The use of gold and silver in some objects has to be also connected with the recent identification of a metallurgical workshop in the Castellot site, dating from the 2nd half of 2nd c. B.C. It seems the technology of the Gold earring from the Castellot site, and specially the gilded ring from Baltarga, had to be connected directly with the Roman military presence in the region from the middle 2nd c. B.C. The iron and silver ring found in the archaeological sites evidence also the use of a complex metallurgical technology, characterized by X-ray techniques, by the local communities' long time before the Roman presence, and likely the knowledge and exploitation of silver and gold resources. \r\n\n <\/div>\n <\/div>\n<\/div>\n
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\n 16_P-XRD<\/b> \/ SÍNTESIS DEL COMPLEJO MOO2CL2-4,4-DIMETILBIPIRIDINA\n <\/div>\n
\n Laura Natalia Niño Daza \n <\/div>\n <\/div>\n
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\n Se disolvieron 238,mg de MoO2Cl2 (1.2 equiv) en 10mL diclorometano seco bajo atmosfera de nitrógeno en un schlenk, al cual se le adicionaron lentamente 184 mg de dimetilbipiridina disueltos en 10mL diclorometano seco bajo atmosfera de nitrógeno. La reacción se agitó durante 3 horas a temperatura ambiente protegida de la luz. La mezcla de reacción se filtró al vacío y el sólido resultante (3) se lavó varias veces con éter etílico para obtener un sólido gris.\r\nLa caracterización molecular se realizó por diversas técnicas instrumentales y la caracterización cristalográfica por difracción de rayos-X de muestras policirstalinas, obteniendo que el compuesto de interés cristaliza en el sistema monoclínico con constantes de celda: a = 22.343 (1) Å, b = 4.923 (3) Å, c =17.176 (1) Å, ß = 99.78° (6) y V = 1861.71 Å3. \n <\/div>\n <\/div>\n<\/div>\n
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\n 09_P-XRD<\/b> \/ SÍNTESIS Y CARACTERIZACIÓN CRISTALOGRÁFICA DE UN NUEVO METAL-ORGANIC FRAMEWORKS DE ZINC Y ÁCIDO TEREFTÁLICO\n <\/div>\n
\n Gloria Stefany Castillo Rueda \n <\/div>\n <\/div>\n
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\n Se preparó una solución (a temperatura ambiente) de 0,1 mL de trietilamina en 10 mL de tolueno. Posteriormente, se preparó otra solución de 4 mL de DMF con una mezcla de 0,2 g del nitrato de zinc hexahidratado [Zn(NO3)2.6H2O] y 0,08 g del ácido tereftálico diluido en 16 mL de tolueno. Las soluciones anteriores se mezclaron con agitación constante durante 16 horas. Finalmente se filtró al vacío, se secó el producto, obteniendo un sólido blanco con punto de fusión de 211°C. El rendimiento de la reacción fue de 51%. \r\n\r\nEl compuesto fue caracterizado molecularmente por diversas técnicas analíticas y cristalográficamente por difracción de rayos-X obteniendo que cristaliza en el sistema monoclínico con constantes de celda: a = 23.689 (7) Å, b = 5.007 (5) Å, c = 23.349 (9) Å, ß = 115.93° (3) y V = 2491.21 Å3. \r\n\n <\/div>\n <\/div>\n<\/div>\n
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\n 14_P-XRD<\/b> \/ SÍNTESIS Y CARACTERIZACIÓN CRISTALOGRÁFICA DEL COMPUESTO MoO2Cl2-4,7-DIMETILFENANTROLINA\n <\/div>\n
\n Juan Jose Rangel Serrano\n <\/div>\n <\/div>\n
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\n El compuesto MoO2Cl2-4,7-dimetilfenantrolina se obtuvo a partir de la disolución de 238 mg de MoO2Cl2 ( 1.2 equiv) en 10 mL de diclorometano seco bajo atmósfera de nitrógeno en un schlenk al cual se le adicionaron lentamente 28mg de 4,7-dimetil-1,10-fenantrolina disueltos en 15 mL de diclorometano seco bajo atmósfera de nitrógeno. La reacción se agitó durante 4 horas a temperatura ambiente protegida de la luz. La mezcla de reacción se filtró al vacío y el sólido resultante se lavó varias veces con éter etílico para obtener un sólido gris. Posteriormente se realizó la caracterización cristalográfica por difracción de rayos-X policristalinas, encontrando que el compuesto de interés cristaliza en el sistema monoclínico con constantes de celda celda: a = 12.918 (4) Å, b = 9.768 (2) Å, c = 11.998 (4) Å, ß = 101.68° (2) y V = 14826.61 Å3\n <\/div>\n <\/div>\n<\/div>\n
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\n 18_P-XRF<\/b> \/ STUDY OF CERAMIC GLAZES FROM GAUDI'S MODERNISME ARCHITECTURE: THE TILES OF CASA VICENS\n <\/div>\n
\n Ignasi QUERALT\n <\/div>\n <\/div>\n
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\n Antoni Gaudí was an architect from Catalonia, Spain, who belonged to the Modernist (Art Nouveau) movement and was famous for his unique style and highly individualistic designs. Gaudi is the author of many of the most famous and representative buildings of Barcelona architectural landscape, such as the Sagrada Familia basilique, the Park Guell, Guell Palace, Casa Milá and Casa Batlló. \r\nGaudí studied at the High School of Architecture in Barcelona from 1873 to 1877, obtaining the title of architect in 1878. The newly named architect immediately began to plan and design innovative buildings, and collaborated with the School his entire life. The Modernist movement was prodigious in its use of ceramics not only in Catalonia, but also in other places throughout the Iberian Peninsula or in many other European countries. Ceramics are certainly omnipresent in Gaudí’s work; their use is perhaps one of their most distinctive characteristics.\r\n\r\nIn 1879, Gaudí’s name first appeared on the books of the Pujol I Bausis ceramic factory which mention a shade of yellow called “Gaudí.” This suggests that from his very first projects, Gaudí used ceramic tile overlay as an essential component of his work. All of Gaudí’s works display a notable wealth of ceramic decoration, well represented in one of its first work: Casa Vicens, built between 1883 and 1888. It is significant because it is an outstanding work dominated by ceramic elements with widely contrasting chromaticism. Casa Vicens was named a UNESCO World Heritage Site in 2005 along with a selection of the architect's other works. Nowadays the home is being restored and it is planned to be opened as a museum next year. Casa Vicens suffered several architectural modifications around 1925 and also some restoration ending the 1990's. In each in each of these modifications some of the tiles were replaced with new identical colour but different manufacturing process.\r\n\r\nThe aim of the present work is focussed on identifying the composition of the body ceramic pieces and the characterization the glazes, approaching to their production techniques and the process they were decorated. The complete characterization of the materials used in Cultural Heritage monuments is a crucial step, enabling to make decisions about restoration and preventive conservation methods. We mainly used non-invasive instrumentation, such as "in-situ" and laboratory Energy dispersive X-ray fluorescence, X-ray diffraction, SEM\/EDX and optical microscopy.\r\n\n <\/div>\n <\/div>\n<\/div>\n
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\n 04_P-XRF<\/b> \/ VALIDACIÓN DE METODOLOGIA PARA ANALISIS MINERALÓGICOS ONSITE DE ROCAS DEL SUBSUELO COLOMBIANO\n <\/div>\n
\n Angelica Maria Carreño Parra\n <\/div>\n <\/div>\n
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\n El análisis y control en tiempo real de un yacimiento sea en un pozo exploratorio o un pozo de producción nos permite reducir el tiempo de respuesta durante las decisiones operacionales de perforación o recobro y obtener una correlación más acertada de la litoestratigrafía del yacimiento. Ante la necesidad de optimizar los procesos de exploración y producción en la industria petrolera, los analizadores portables prometen ser una tecnología de fácil operación en las campañas onsite particulares de esta industria.\r\n\r\nEsta metodología propuso el uso del análisis por DRX de montajes desorientados tanto a nivel de la roca total como a nivel de la fracción menor de 2 µm mediante el uso de un difractómetro de rayos-x portable marca Olympus modelo Terra-441 bajo condiciones de ensayo de 30 kV de energía y 350 µA de intensidad. La validación de esta metodología se desarrolló con mezclas de referencia y rocas del subsuelo colombiano de yacimientos convencionales y no convencionales.\n <\/div>\n <\/div>\n<\/div>\n"}