A numerical analysis of NMR pore-pore exchange measurements using micro X-ray computed tomography

Pore-pore relaxation exchange experiments are a recent development and hold great promise to spectrally derive length scales and connectivity information relevant for transport in porous media. However, for large pores, NMR diffusion-relaxation techniques reach a limit because bulk relaxation becomes dominant. A combination of NMR and Xray-CT techniques could be beneficial and lead to better models for regions of unresolved porosity in CT images, increasing the accuracy of image based calculations of transport properties. In this study we carry out numerical NMR pore-pore exchange experiments on selected Xray-CT images of sandstones and carbonate rock, while at the same time tracking information about the geometry and topology of the pore space. We use pore partitioning techniques and geometric distance fields to relate T2-T2 relaxation exchange spectra to underlying structural quantities. It is shown that T2-T2 pore-pore exchange measurements at room temperatures for the samples considered likely reflect exchange between pores and throats or pores and roughness

Atención Primaria de Salud en el siglo XXI.

La Atención Primaria en Salud (APS), inicialmente definida en la Conferencia de Alma-Ata en 1978, como la “asistencia sanitaria esencial basada en métodos y tecnologías prácticos, científicamente fundados y socialmente aceptables, puesta al alcance de todos los individuos y familias de la comunidad, mediante su plena participación y a un costo que la comunidad y el país puedan soportar en todas y cada de las etapas de su desarrollo, con un espíritu de autorresponsabilidad y autodeterminación”. En este artículo será analizado a la luz de las evidencias y transformaciones producidas por esta estrategia en los últimos 25 años, y su interpretación desde la perspectiva de la modernidad.&nbsp

SALUTOGÉNESIS Y SALUD PÚBLICA. REFLEXIONES PRÁCTICAS SOCIALES.

La Salud Pública, en tanto disciplina del campo científico de las ciencias médicas, se ubica en una dualidad propia de las identidades que le son inmanentes. Es decir, por una parte, ha consolidado el desarrollo de sus prácticas sociales o praxis de la cuestión social,  y por otra, su responsabilidad y sentido de pertenencia a un campo científico dominante, que ha desarrollado metodologías y tecnologías, basadas en evidencias. Este trabajo relaciona este campo de conocimiento con la relativamente novedosa Salutogénesis.Palabras claves: Salud pública, Salutogénesis, Vida saludable, Estrategias sanitarias

A numerical analysis of NMR pore-pore exchange measurements using micro X-ray computed tomography

Pore-pore relaxation exchange experiments are a recent development and hold great promise to spectrally derive length scales and connectivity information relevant for transport in porous media. However, for large pores, NMR diffusion-relaxation techniques reach a limit because bulk relaxation becomes dominant. A combination of NMR and Xray-CT techniques could be beneficial and lead to better models for regions of unresolved porosity in CT images, increasing the accuracy of image based calculations of transport properties. In this study we carry out numerical NMR pore-pore exchange experiments on selected Xray-CT images of sandstones and carbonate rock, while at the same time tracking information about the geometry and topology of the pore space. We use pore partitioning techniques and geometric distance fields to relate T2-T2 relaxation exchange spectra to underlying structural quantities. It is shown that T2-T2 pore-pore exchange measurements at room temperatures for the samples considered likely reflect exchange between pores and throats or pores and roughness

A numerical analysis of NMR pore-pore exchange measurements using micro X-ray computed tomography

Pore-pore relaxation exchange experiments are a recent development and hold great promise to spectrally derive length scales and connectivity information relevant for transport in porous media. However, for large pores, NMR diffusion-relaxation techniques reach a limit because bulk relaxation becomes dominant. A combination of NMR and Xray-CT techniques could be beneficial and lead to better models for regions of unresolved porosity in CT images, increasing the accuracy of image based calculations of transport properties. In this study we carry out numerical NMR pore-pore exchange experiments on selected Xray-CT images of sandstones and carbonate rock, while at the same time tracking information about the geometry and topology of the pore space. We use pore partitioning techniques and geometric distance fields to relate T2-T2 relaxation exchange spectra to underlying structural quantities. It is shown that T2-T2 pore-pore exchange measurements at room temperatures for the samples considered likely reflect exchange between pores and throats or pores and roughness