D. Munoz-Paniagua - Academia.edu (original) (raw)
Papers by D. Munoz-Paniagua
Journal of Pharmacy & Pharmaceutical Sciences, 2013
Purpose. We investigated elemental strontium and/or bisphosphonate drug incorporation upon the co... more Purpose. We investigated elemental strontium and/or bisphosphonate drug incorporation upon the compositional and biomechanical properties of vertebral bone, in a rat model of Osteoporosis secondary to ovariectomy. Methods. Six month old female rats were ovariectomized (OVX) and divided into untreated OVX-Vehicle, OVX-RIS (Risedronate bisphosphonate [BP] treated), OVX-SrR (Strontium Ranelate [Protos®] treated), combination OVX-RIS+SrR, and sham-operated controls. After 16 weeks of treatment, rats were euthanized and lumbar vertebra were dissected. Micro-Computed Tomography (micro-CT), Electron Probe Micro-Analysis (EPMA), mechanical testing in compression and nano-indentation testing were then undertaken to evaluate bone morphometry, elemental composition, material properties and strength. Results. Bone Volume was significantly reduced in the OVX-Vehicle (133±10mm3) compared with OVX-RIS (169±22mm3), OVX-SrR (145±2mm3), and OVX-RIS+SrR (172±8mm3). EPMA mapped elemental Sr deposition ...
Wear, 2007
The nanomechanical properties of antiwear films formed from zinc dialkyl-dithiophosphates (ZDDPs)... more The nanomechanical properties of antiwear films formed from zinc dialkyl-dithiophosphates (ZDDPs) on steel have been studied by nanoindentation techniques as a function of temperature. X-ray absorption P K-and L-near edge structure (XANES) spectroscopy has shown that films prepared from oils containing ZDDPs on 52100 steel (pin on flat coupons) consist primarily of medium chain polyphosphates with sulphur (S K-edge) predominantly present as sulphide. Using various scanning probe techniques, high-resolution topographic images and mechanical properties can be extracted at the same length scale. Using focused ion beam (FIB) milling we have compared real cross-sectional film thickness with a value estimated from the P K-edge XANES. We report the first measurements of the elastic modulus of the antiwear films at elevated temperatures relevant to the automobile operating conditions (T ≤ 200 • C). The antiwear films demonstrated a relatively constant indentation modulus over a wide range of temperatures consistent with their efficacy in reducing wear by preventing asperity contact.
Nanotechnology in Construction 3, 2009
Nanotechnology emerges out of fundamental science through capability for accurate, repeatable and... more Nanotechnology emerges out of fundamental science through capability for accurate, repeatable and reproducible measurements on the nanoscale which allows scientists and engineers to accumulate knowledge. Understanding the measurement science is the first step towards development of new ideas. This paper describes some research initiatives which underpin the development of nanotechnology. Programs underway at the National Research Council of Canada include: development of metrological scanning-probe microscope instrumentation for dimensional calibration, materials characterization, development of artefacts designed specifically for dimensional calibration, investigation of metrology for application to soft materials and investigation of intrinsic length standards for realization of the SI metre at the nanoscale.
Thin Solid Films, 2006
Dissolved hydrogen is known to reduce the corrosion resistance of a passive oxide film on iron an... more Dissolved hydrogen is known to reduce the corrosion resistance of a passive oxide film on iron and its alloys, especially towards pitting corrosion. Electrochemical techniques have been used to show that the passive films are changed by dissolved hydrogen in an alloy substrate, but direct confirmation of the chemical and compositional profiles and changes has been missing. In this paper we report the direct profiling and compositional analysis of the 4 nm passive film on X-70 steel by Auger electron spectroscopy (AES), secondary ion mass spectrometry (SIMS), X-ray photoelectron spectroscopy (XPS) and nuclear reaction analysis (NRA) while hydrogen (deuterium) is charged into the alloy samples from the reverse, unpassivated side. The only route for D to the passive film is therefore by dissolution and diffusion. We show that the original duplex structure of the passive film is converted to a more continuous film containing hydroxyl groups, by reaction with the dissolved hydrogen. This...
Tribology - Materials, Surfaces & Interfaces, 2007
ABSTRACT The interaction of a friction modifier and a calcium phenate detergent additive, with zi... more ABSTRACT The interaction of a friction modifier and a calcium phenate detergent additive, with zinc dialkyl dithiophosphates (ZDDPs) in the formation of antiwear films on A383, has been studied using synchrotron radiation and nanoindentation techniques. X-ray absorption near edge structure (XANES) spectroscopy has shown that films prepared from oils containing both ZDDP and detergent, and ZDDP and molybdenum dithiocarbamate (MoDTC), are chemically similar to, but thicker than those made from oils containing only ZDDP. In addition, wear was greatly reduced in the presence of the detergent which was correlated with the basicity and the presence of the friction modifier. The phosphorus K and L edge XANES spectra show that the tribofilms are polyphosphate glasses of similar nature to those found on steel, but characterised by a shorter chain length. The sulphur K edge shows a MoS2 like film and under certain conditions, the presence of a sulphate species is detected. High resolution topographic images and mechanical properties were determined by atomic force microscopy and imaging nanoindentation. The films formed in the presence of the detergent exhibited similar mechanical responses independent of the conditions tested. The indentation modulus of the films on the Al matrix always appear much softer than the films formed on the Si grains whether or not the lubricant contains only ZDDP, or both ZDDP and MoDTC.
Tribology Letters, 2006
Phosphorus L-edge and oxygen K-edge X-ray PhotoEmission Electron Microscopy (XPEEM) have been use... more Phosphorus L-edge and oxygen K-edge X-ray PhotoEmission Electron Microscopy (XPEEM) have been used to characterize the chemical nature of the cation present in tribochemical films via comparison with model Fe 2+ and Zn 2+ compounds. The results are contrasted to the P L-edge, P K-edge and S K-edge XANES data. The findings suggest that antiwear pads containing long chain zinc polyphosphate glass are formed at the points of asperity contact, and a thin, short chain zinc polyphosphate film is formed where no asperity contact is made. SEM/EDX measurements helped to elucidate the distribution of the elements, and strong spatial correlations were observed between P, O, Zn and S in the pads, indicating that they are composed mostly of zinc polyphosphates, especially near the surface. The zinc polyphosphate antiwear pads are characterized by a much lower modulus than that observed on the thin film regions, the latter being characteristic of the substrate steel.
Journal of Applied Physics, 2009
... 1, a-Ge transforms to a metallic phase at 67 GPa, either to -tin Ge, or to hda-Ge according ... more ... 1, a-Ge transforms to a metallic phase at 67 GPa, either to -tin Ge, or to hda-Ge according to different studies.914 An in situ XRD study by Imai et al.12 found that, on unload-ing, the metallic phase first transforms to bc-8 Ge Ge-IV, which is unstable at room temperature and ...
Quercus, 2006
Información del artículo Estudio genético del lobo en el País Vasco.
Galemys, Dec 1, 2003
RESUMEN Hemos llevado a cabo una búsqueda de madrigueras de tejón (Meles meles Linnaeus, 1758) o ... more RESUMEN Hemos llevado a cabo una búsqueda de madrigueras de tejón (Meles meles Linnaeus, 1758) o tejoneras, en un área de 112 km2, perteneciente al Parque Natural de Gorbea (Vizcaya, País Vasco), con el fin de realizar un análisis de selección a partir de los datos de uso y disponibilidad de las distintas variables de hábitat. Encontramos una baja densidad de tejoneras (0,142 tejoneras/km2) localizadas, en una elevada proporción, en plantaciones forestales, principalmente de coníferas exóticas, y en menor medida en ...
Quercus, Jul 1, 2006
Biblioteca de la Universidad Complutense de Madrid, Base de datos de artículos de revistas, ...
Voces, 2009
RESUMEN: Ciertos términos zoológicos recogidos en los nomina anima-lium del Laterculus de Polemio... more RESUMEN: Ciertos términos zoológicos recogidos en los nomina anima-lium del Laterculus de Polemio Silvio resultan desconocidos y difíciles de identificar. Unas veces mediante las correcciones oportunas y otras recurriendo a los testimonios escritos que conforman la tradición ...
Nanotechnology in Construction 3, 2009
... JE Decker, A. Bogdanov, BJ Eves, D. Goodchild, L. Johnston, N. Kim, M. McDermott, D. Munoz-Pa... more ... JE Decker, A. Bogdanov, BJ Eves, D. Goodchild, L. Johnston, N. Kim, M. McDermott, D. Munoz-Paniagua, JR Pekelsky, S. Wingar, and S. Zou National ... lithography or e-beam lithography relies in the physical transfer of a 3-D mold or template into an intermediate poly-mer which ...
Journal of Pharmacy & Pharmaceutical Sciences, 2013
Purpose. We investigated elemental strontium and/or bisphosphonate drug incorporation upon the co... more Purpose. We investigated elemental strontium and/or bisphosphonate drug incorporation upon the compositional and biomechanical properties of vertebral bone, in a rat model of Osteoporosis secondary to ovariectomy. Methods. Six month old female rats were ovariectomized (OVX) and divided into untreated OVX-Vehicle, OVX-RIS (Risedronate bisphosphonate [BP] treated), OVX-SrR (Strontium Ranelate [Protos®] treated), combination OVX-RIS+SrR, and sham-operated controls. After 16 weeks of treatment, rats were euthanized and lumbar vertebra were dissected. Micro-Computed Tomography (micro-CT), Electron Probe Micro-Analysis (EPMA), mechanical testing in compression and nano-indentation testing were then undertaken to evaluate bone morphometry, elemental composition, material properties and strength. Results. Bone Volume was significantly reduced in the OVX-Vehicle (133±10mm3) compared with OVX-RIS (169±22mm3), OVX-SrR (145±2mm3), and OVX-RIS+SrR (172±8mm3). EPMA mapped elemental Sr deposition ...
Wear, 2007
The nanomechanical properties of antiwear films formed from zinc dialkyl-dithiophosphates (ZDDPs)... more The nanomechanical properties of antiwear films formed from zinc dialkyl-dithiophosphates (ZDDPs) on steel have been studied by nanoindentation techniques as a function of temperature. X-ray absorption P K-and L-near edge structure (XANES) spectroscopy has shown that films prepared from oils containing ZDDPs on 52100 steel (pin on flat coupons) consist primarily of medium chain polyphosphates with sulphur (S K-edge) predominantly present as sulphide. Using various scanning probe techniques, high-resolution topographic images and mechanical properties can be extracted at the same length scale. Using focused ion beam (FIB) milling we have compared real cross-sectional film thickness with a value estimated from the P K-edge XANES. We report the first measurements of the elastic modulus of the antiwear films at elevated temperatures relevant to the automobile operating conditions (T ≤ 200 • C). The antiwear films demonstrated a relatively constant indentation modulus over a wide range of temperatures consistent with their efficacy in reducing wear by preventing asperity contact.
Nanotechnology in Construction 3, 2009
Nanotechnology emerges out of fundamental science through capability for accurate, repeatable and... more Nanotechnology emerges out of fundamental science through capability for accurate, repeatable and reproducible measurements on the nanoscale which allows scientists and engineers to accumulate knowledge. Understanding the measurement science is the first step towards development of new ideas. This paper describes some research initiatives which underpin the development of nanotechnology. Programs underway at the National Research Council of Canada include: development of metrological scanning-probe microscope instrumentation for dimensional calibration, materials characterization, development of artefacts designed specifically for dimensional calibration, investigation of metrology for application to soft materials and investigation of intrinsic length standards for realization of the SI metre at the nanoscale.
Thin Solid Films, 2006
Dissolved hydrogen is known to reduce the corrosion resistance of a passive oxide film on iron an... more Dissolved hydrogen is known to reduce the corrosion resistance of a passive oxide film on iron and its alloys, especially towards pitting corrosion. Electrochemical techniques have been used to show that the passive films are changed by dissolved hydrogen in an alloy substrate, but direct confirmation of the chemical and compositional profiles and changes has been missing. In this paper we report the direct profiling and compositional analysis of the 4 nm passive film on X-70 steel by Auger electron spectroscopy (AES), secondary ion mass spectrometry (SIMS), X-ray photoelectron spectroscopy (XPS) and nuclear reaction analysis (NRA) while hydrogen (deuterium) is charged into the alloy samples from the reverse, unpassivated side. The only route for D to the passive film is therefore by dissolution and diffusion. We show that the original duplex structure of the passive film is converted to a more continuous film containing hydroxyl groups, by reaction with the dissolved hydrogen. This...
Tribology - Materials, Surfaces & Interfaces, 2007
ABSTRACT The interaction of a friction modifier and a calcium phenate detergent additive, with zi... more ABSTRACT The interaction of a friction modifier and a calcium phenate detergent additive, with zinc dialkyl dithiophosphates (ZDDPs) in the formation of antiwear films on A383, has been studied using synchrotron radiation and nanoindentation techniques. X-ray absorption near edge structure (XANES) spectroscopy has shown that films prepared from oils containing both ZDDP and detergent, and ZDDP and molybdenum dithiocarbamate (MoDTC), are chemically similar to, but thicker than those made from oils containing only ZDDP. In addition, wear was greatly reduced in the presence of the detergent which was correlated with the basicity and the presence of the friction modifier. The phosphorus K and L edge XANES spectra show that the tribofilms are polyphosphate glasses of similar nature to those found on steel, but characterised by a shorter chain length. The sulphur K edge shows a MoS2 like film and under certain conditions, the presence of a sulphate species is detected. High resolution topographic images and mechanical properties were determined by atomic force microscopy and imaging nanoindentation. The films formed in the presence of the detergent exhibited similar mechanical responses independent of the conditions tested. The indentation modulus of the films on the Al matrix always appear much softer than the films formed on the Si grains whether or not the lubricant contains only ZDDP, or both ZDDP and MoDTC.
Tribology Letters, 2006
Phosphorus L-edge and oxygen K-edge X-ray PhotoEmission Electron Microscopy (XPEEM) have been use... more Phosphorus L-edge and oxygen K-edge X-ray PhotoEmission Electron Microscopy (XPEEM) have been used to characterize the chemical nature of the cation present in tribochemical films via comparison with model Fe 2+ and Zn 2+ compounds. The results are contrasted to the P L-edge, P K-edge and S K-edge XANES data. The findings suggest that antiwear pads containing long chain zinc polyphosphate glass are formed at the points of asperity contact, and a thin, short chain zinc polyphosphate film is formed where no asperity contact is made. SEM/EDX measurements helped to elucidate the distribution of the elements, and strong spatial correlations were observed between P, O, Zn and S in the pads, indicating that they are composed mostly of zinc polyphosphates, especially near the surface. The zinc polyphosphate antiwear pads are characterized by a much lower modulus than that observed on the thin film regions, the latter being characteristic of the substrate steel.
Journal of Applied Physics, 2009
... 1, a-Ge transforms to a metallic phase at 67 GPa, either to -tin Ge, or to hda-Ge according ... more ... 1, a-Ge transforms to a metallic phase at 67 GPa, either to -tin Ge, or to hda-Ge according to different studies.914 An in situ XRD study by Imai et al.12 found that, on unload-ing, the metallic phase first transforms to bc-8 Ge Ge-IV, which is unstable at room temperature and ...
Quercus, 2006
Información del artículo Estudio genético del lobo en el País Vasco.
Galemys, Dec 1, 2003
RESUMEN Hemos llevado a cabo una búsqueda de madrigueras de tejón (Meles meles Linnaeus, 1758) o ... more RESUMEN Hemos llevado a cabo una búsqueda de madrigueras de tejón (Meles meles Linnaeus, 1758) o tejoneras, en un área de 112 km2, perteneciente al Parque Natural de Gorbea (Vizcaya, País Vasco), con el fin de realizar un análisis de selección a partir de los datos de uso y disponibilidad de las distintas variables de hábitat. Encontramos una baja densidad de tejoneras (0,142 tejoneras/km2) localizadas, en una elevada proporción, en plantaciones forestales, principalmente de coníferas exóticas, y en menor medida en ...
Quercus, Jul 1, 2006
Biblioteca de la Universidad Complutense de Madrid, Base de datos de artículos de revistas, ...
Voces, 2009
RESUMEN: Ciertos términos zoológicos recogidos en los nomina anima-lium del Laterculus de Polemio... more RESUMEN: Ciertos términos zoológicos recogidos en los nomina anima-lium del Laterculus de Polemio Silvio resultan desconocidos y difíciles de identificar. Unas veces mediante las correcciones oportunas y otras recurriendo a los testimonios escritos que conforman la tradición ...
Nanotechnology in Construction 3, 2009
... JE Decker, A. Bogdanov, BJ Eves, D. Goodchild, L. Johnston, N. Kim, M. McDermott, D. Munoz-Pa... more ... JE Decker, A. Bogdanov, BJ Eves, D. Goodchild, L. Johnston, N. Kim, M. McDermott, D. Munoz-Paniagua, JR Pekelsky, S. Wingar, and S. Zou National ... lithography or e-beam lithography relies in the physical transfer of a 3-D mold or template into an intermediate poly-mer which ...