Proyectos

[vc_section el_class="container mx-auto align-items-center circle--pattern" css=".vc_custom_1648956589196{padding-top: 3rem !important;}"][vc_row el_class="pb-5"][vc_column][vc_wp_custommenu nav_menu="6"][uoh_breadcrumb_component automatic_breadcrumb="true"][uoh_title_component title_dropdown="big" title_decorator="true"]{{title}}[/uoh_title_component][vc_column_text css=""]Far from simple steric repulsion, i.e., volumetric repulsion, the dynamics of granular systems are driven by a menagerie of interactions: dissipative collisions, van der Waals forces, electrostatic Coulomb and polarization forces, viscous drag and, in the presence of even minute amounts of liquid, capillary bridges or ice coatings. Despite its importance and the development of many powerful experimental, numerical and theoretical tools, until now, a unified description of granular media is lacking, even for the simplest model situation of perfectly spherical, impenetrable and dissipative particles. One of the most important topics in granular media research is clustering, for both fundamental and applied reasons. Clustering produces large gradients, which makes usual gradient perturbations schemes more difficult, which even poses questions about the validity of continuum approaches for these systems. Clustering and coarsening are also relevant for many industrial applications, including grain and powder storage, transport and manipulation, in the food, mining and chemical industries, to mention a few. Electrostatically–induced granular clustering has emerged as a mechanism with fundamental and practical implications. The electrification of such systems occurs through tribocharging—the exchange of charge between contacting surfaces. Despite its importance, how insulators transfer such large amounts of charge during contact is not well-understood. How this can also occur for identical materials during contact is puzzling as well. Furthermore, the nature of the charge carrier is also not settled. Concerning applications, just recently electrostatically–induced granular clustering has been revealed as a possible enhancing mechanism for granular coarsening in a very important and unsolved issue: the formation of planetesimals, which can be considered as baby planets (from 1 km size it is expected that gravity should be the driving accretion force). Indeed, despite clear evidence, our current theoretical understanding is that rocky planets should not exist; a basic ingredient seems to be missing for explaining the clustering of grains in the sub- mm to cm range. We propose that electrification through tribocharging is the missing ingredient. Thus, the main objective of this proposal is to address how different pair-wise interactions and, in general, particle and collisional properties, lead to sustained cluster growth. We are developing two experimental systems to make concrete steps toward this goal. In the first, we are using a free-fall apparatus to observe collisions between sub-mm particles in vacuum and zero-gravity conditions. In the second, we are forging into the new territory of interactions between millimeter-scale particles or clusters with a controlled acoustic levitation setup. In order to understand the microphysics of grain growth in the sub-mm to cm range, our immediate objective is to characterize the sticking efficiencies and dominant forces—including the possibility of same-material tribocharging—in a variety of conditions. In the first experimental setup, we will focus on few-particle interactions and clustering. In the second, we will study controlled collisions between a few up to many-particle clusters. Working on these two experiments in tandem will enable us to characterize collisions over decades of data in cluster size and impact energy, and quantify same-material tribocharging. For both experiments we will use standard dielectric materials (as ZrO2:SiO2 composites) as a benchmark. Then, we will use analog meteorite materials (e.g. San Carlos Olivine) in both setups, and original meteorite grains (Allende meteorite) with the ultrasonic setup, where controlled collisions can be done for smaller amounts of material. The outcome of such experiments will be a phase portrait of collisional aggregation efficiency covering features ranging from particle and cluster size to particle interactions, particle composition and impact energy. One particular contribution we will focus on is the effect of tribocharging on the formation efficiency of larger clusters, which should be relevant toward our current understanding of asteroid and planetesimal formation.[/vc_column_text][/vc_column][/vc_row][/vc_section][vc_section css=".vc_custom_1649209804184{background-color: #f6faff !important;}" el_class="p-md-0 pt-md-5"][vc_row el_class="container mx-auto align-items-center p-md-0 pt-5"][vc_column el_class="p-0"][/vc_column][/vc_row][/vc_section][vc_section css=".vc_custom_1649210787516{background-color: #f6faff !important;}" el_class="p-md-0 pt-md-5 pb-md-5"][vc_row el_class="container mx-auto align-items-center"][vc_column][/vc_column][/vc_row][/vc_section]

[vc_section el_class="container mx-auto align-items-center circle--pattern" css=".vc_custom_1648956589196{padding-top: 3rem !important;}"][vc_row el_class="pb-5"][vc_column][vc_wp_custommenu nav_menu="6"][uoh_breadcrumb_component automatic_breadcrumb="true"][uoh_title_component title_dropdown="big" title_decorator="true"]{{title}}[/uoh_title_component][vc_column_text css=""]Far from simple steric repulsion, i.e., volumetric repulsion, the dynamics of granular systems are driven by a menagerie of interactions: dissipative collisions, van der Waals forces, electrostatic Coulomb and polarization forces, viscous drag and, in the presence of even minute amounts of liquid, capillary bridges or ice coatings. Despite its importance and the development of many powerful experimental, numerical and theoretical tools, until now, a unified description of granular media is lacking, even for the simplest model situation of perfectly spherical, impenetrable and dissipative particles. One of the most important topics in granular media research is clustering, for both fundamental and applied reasons. Clustering produces large gradients, which makes usual gradient perturbations schemes more difficult, which even poses questions about the validity of continuum approaches for these systems. Clustering and coarsening are also relevant for many industrial applications, including grain and powder storage, transport and manipulation, in the food, mining and chemical industries, to mention a few. Electrostatically–induced granular clustering has emerged as a mechanism with fundamental and practical implications. The electrification of such systems occurs through tribocharging—the exchange of charge between contacting surfaces. Despite its importance, how insulators transfer such large amounts of charge during contact is not well-understood. How this can also occur for identical materials during contact is puzzling as well. Furthermore, the nature of the charge carrier is also not settled. Concerning applications, just recently electrostatically–induced granular clustering has been revealed as a possible enhancing mechanism for granular coarsening in a very important and unsolved issue: the formation of planetesimals, which can be considered as baby planets (from 1 km size it is expected that gravity should be the driving accretion force). Indeed, despite clear evidence, our current theoretical understanding is that rocky planets should not exist; a basic ingredient seems to be missing for explaining the clustering of grains in the sub- mm to cm range. We propose that electrification through tribocharging is the missing ingredient. Thus, the main objective of this proposal is to address how different pair-wise interactions and, in general, particle and collisional properties, lead to sustained cluster growth. We are developing two experimental systems to make concrete steps toward this goal. In the first, we are using a free-fall apparatus to observe collisions between sub-mm particles in vacuum and zero-gravity conditions. In the second, we are forging into the new territory of interactions between millimeter-scale particles or clusters with a controlled acoustic levitation setup. In order to understand the microphysics of grain growth in the sub-mm to cm range, our immediate objective is to characterize the sticking efficiencies and dominant forces—including the possibility of same-material tribocharging—in a variety of conditions. In the first experimental setup, we will focus on few-particle interactions and clustering. In the second, we will study controlled collisions between a few up to many-particle clusters. Working on these two experiments in tandem will enable us to characterize collisions over decades of data in cluster size and impact energy, and quantify same-material tribocharging. For both experiments we will use standard dielectric materials (as ZrO2:SiO2 composites) as a benchmark. Then, we will use analog meteorite materials (e.g. San Carlos Olivine) in both setups, and original meteorite grains (Allende meteorite) with the ultrasonic setup, where controlled collisions can be done for smaller amounts of material. The outcome of such experiments will be a phase portrait of collisional aggregation efficiency covering features ranging from particle and cluster size to particle interactions, particle composition and impact energy. One particular contribution we will focus on is the effect of tribocharging on the formation efficiency of larger clusters, which should be relevant toward our current understanding of asteroid and planetesimal formation.[/vc_column_text][/vc_column][/vc_row][/vc_section][vc_section css=".vc_custom_1649209804184{background-color: #f6faff !important;}" el_class="p-md-0 pt-md-5"][vc_row el_class="container mx-auto align-items-center p-md-0 pt-5"][vc_column el_class="p-0"][/vc_column][/vc_row][/vc_section][vc_section css=".vc_custom_1649210787516{background-color: #f6faff !important;}" el_class="p-md-0 pt-md-5 pb-md-5"][vc_row el_class="container mx-auto align-items-center"][vc_column][/vc_column][/vc_row][/vc_section]

[vc_section el_class="container mx-auto align-items-center circle--pattern" css=".vc_custom_1648956589196{padding-top: 3rem !important;}"][vc_row el_class="pb-5"][vc_column][vc_wp_custommenu nav_menu="6"][uoh_breadcrumb_component automatic_breadcrumb="true"][uoh_title_component title_dropdown="big" title_decorator="true"]{{title}}[/uoh_title_component][vc_column_text css=""]Transferencia y adopción de Tecnologías para la Gestión de Riesgo en el Proceso Productivo de la Cereza: hacia una agricultura de precisión para la Región de O’Higgins[/vc_column_text][/vc_column][/vc_row][/vc_section][vc_section css=".vc_custom_1649209804184{background-color: #f6faff !important;}" el_class="p-md-0 pt-md-5"][vc_row el_class="container mx-auto align-items-center p-md-0 pt-5"][vc_column el_class="p-0"][/vc_column][/vc_row][/vc_section][vc_section css=".vc_custom_1649210787516{background-color: #f6faff !important;}" el_class="p-md-0 pt-md-5 pb-md-5"][vc_row el_class="container mx-auto align-items-center"][vc_column][/vc_column][/vc_row][/vc_section]

[vc_section el_class="container mx-auto align-items-center circle--pattern" css=".vc_custom_1648956589196{padding-top: 3rem !important;}"][vc_row el_class="pb-5"][vc_column][vc_wp_custommenu nav_menu="6"][uoh_breadcrumb_component automatic_breadcrumb="true"][uoh_title_component title_dropdown="big" title_decorator="true"]{{title}}[/uoh_title_component][vc_column_text css=""]Transferencia y adopción de Tecnologías para la Gestión de Riesgo en el Proceso Productivo de la Cereza: hacia una agricultura de precisión para la Región de O’Higgins[/vc_column_text][/vc_column][/vc_row][/vc_section][vc_section css=".vc_custom_1649209804184{background-color: #f6faff !important;}" el_class="p-md-0 pt-md-5"][vc_row el_class="container mx-auto align-items-center p-md-0 pt-5"][vc_column el_class="p-0"][/vc_column][/vc_row][/vc_section][vc_section css=".vc_custom_1649210787516{background-color: #f6faff !important;}" el_class="p-md-0 pt-md-5 pb-md-5"][vc_row el_class="container mx-auto align-items-center"][vc_column][/vc_column][/vc_row][/vc_section]

[vc_section el_class="container mx-auto align-items-center circle--pattern" css=".vc_custom_1648956589196{padding-top: 3rem !important;}"][vc_row el_class="pb-5"][vc_column][vc_wp_custommenu nav_menu="6"][uoh_breadcrumb_component automatic_breadcrumb="true"][uoh_title_component title_dropdown="big" title_decorator="true"]{{title}}[/uoh_title_component][vc_column_text css=""]Objetivo general: sesarrollar un modelo de balance hídrico en acuífero de roca fracturada. Objetivos específicos: (i) identificar un sitio piloto de roca fracturada; (ii) instrumentar el piloto para monitorear los flujos hídricos; (iii) diseñar e implementar la metodología de balance hídrico en acuíferos de roca fracturada.[/vc_column_text][/vc_column][/vc_row][/vc_section][vc_section css=".vc_custom_1649209804184{background-color: #f6faff !important;}" el_class="p-md-0 pt-md-5"][vc_row el_class="container mx-auto align-items-center p-md-0 pt-5"][vc_column el_class="p-0"][/vc_column][/vc_row][/vc_section][vc_section css=".vc_custom_1649210787516{background-color: #f6faff !important;}" el_class="p-md-0 pt-md-5 pb-md-5"][vc_row el_class="container mx-auto align-items-center"][vc_column][/vc_column][/vc_row][/vc_section]

[vc_section el_class="container mx-auto align-items-center circle--pattern" css=".vc_custom_1648956589196{padding-top: 3rem !important;}"][vc_row el_class="pb-5"][vc_column][vc_wp_custommenu nav_menu="6"][uoh_breadcrumb_component automatic_breadcrumb="true"][uoh_title_component title_dropdown="big" title_decorator="true"]{{title}}[/uoh_title_component][vc_column_text css=""]Objetivo general: sesarrollar un modelo de balance hídrico en acuífero de roca fracturada. Objetivos específicos: (i) identificar un sitio piloto de roca fracturada; (ii) instrumentar el piloto para monitorear los flujos hídricos; (iii) diseñar e implementar la metodología de balance hídrico en acuíferos de roca fracturada.[/vc_column_text][/vc_column][/vc_row][/vc_section][vc_section css=".vc_custom_1649209804184{background-color: #f6faff !important;}" el_class="p-md-0 pt-md-5"][vc_row el_class="container mx-auto align-items-center p-md-0 pt-5"][vc_column el_class="p-0"][/vc_column][/vc_row][/vc_section][vc_section css=".vc_custom_1649210787516{background-color: #f6faff !important;}" el_class="p-md-0 pt-md-5 pb-md-5"][vc_row el_class="container mx-auto align-items-center"][vc_column][/vc_column][/vc_row][/vc_section]

[vc_section el_class="container mx-auto align-items-center circle--pattern" css=".vc_custom_1648956589196{padding-top: 3rem !important;}"][vc_row el_class="pb-5"][vc_column][vc_wp_custommenu nav_menu="6"][uoh_breadcrumb_component automatic_breadcrumb="true"][uoh_title_component title_dropdown="big" title_decorator="true"]{{title}}[/uoh_title_component][vc_column_text css=""][/vc_column_text][/vc_column][/vc_row][/vc_section][vc_section css=".vc_custom_1649209804184{background-color: #f6faff !important;}" el_class="p-md-0 pt-md-5"][vc_row el_class="container mx-auto align-items-center p-md-0 pt-5"][vc_column el_class="p-0"][/vc_column][/vc_row][/vc_section][vc_section css=".vc_custom_1649210787516{background-color: #f6faff !important;}" el_class="p-md-0 pt-md-5 pb-md-5"][vc_row el_class="container mx-auto align-items-center"][vc_column][/vc_column][/vc_row][/vc_section]

[vc_section el_class="container mx-auto align-items-center circle--pattern" css=".vc_custom_1648956589196{padding-top: 3rem !important;}"][vc_row el_class="pb-5"][vc_column][vc_wp_custommenu nav_menu="6"][uoh_breadcrumb_component automatic_breadcrumb="true"][uoh_title_component title_dropdown="big" title_decorator="true"]{{title}}[/uoh_title_component][vc_column_text css=""][/vc_column_text][/vc_column][/vc_row][/vc_section][vc_section css=".vc_custom_1649209804184{background-color: #f6faff !important;}" el_class="p-md-0 pt-md-5"][vc_row el_class="container mx-auto align-items-center p-md-0 pt-5"][vc_column el_class="p-0"][/vc_column][/vc_row][/vc_section][vc_section css=".vc_custom_1649210787516{background-color: #f6faff !important;}" el_class="p-md-0 pt-md-5 pb-md-5"][vc_row el_class="container mx-auto align-items-center"][vc_column][/vc_column][/vc_row][/vc_section]

[vc_section el_class="container mx-auto align-items-center circle--pattern" css=".vc_custom_1648956589196{padding-top: 3rem !important;}"][vc_row el_class="pb-5"][vc_column][vc_wp_custommenu nav_menu="6"][uoh_breadcrumb_component automatic_breadcrumb="true"][uoh_title_component title_dropdown="big" title_decorator="true"]{{title}}[/uoh_title_component][vc_column_text css=""]Las ondas y las estructuras coherentes están presentes como entidades individuales en varios contextos físicos, astronómicos y geofísicos, y particularmente en los fluidos. Las situaciones realistas generalmente involucran a ambos, lo que lleva a procesos de interacción complejos que son difíciles de separar y desenredar. En esta propuesta nos enfocamos en estudiar experimentalmente cómo la presencia de estructuras coherentes, tales como vórtices o singularidades, afectan las propiedades de las ondas superficiales en un régimen turbulento. Para ello, construiremos dos montajes experimentales para poder estudiar de forma sistemática las propiedades estadísticas de las ondas cuando interactúan con las estructuras mencionadas. Ambos sistemas tienen la ventaja de que, ajustando los parámetros de forzamiento, podemos controlar la aparición e intensidad de las estructuras. Por lo tanto, un estudio sistemático de su influencia en turbulencia de ondas (WT) es sencillo. La naturaleza intermitente del campo de ondas, así como los mecanismos detrás de la ruptura del espectro de WT en presencia de estas estructuras son algunas de las preguntas que pretendemos responder. Para abordar estas preguntas, proponemos realizar mediciones espaciotemporales, como la fotografía de luz difusa (DLP) y la velocimetría de imagen de partículas (PIV). Los resultados que surjan de esta investigación podrían ser de gran importancia para una teoría que, si bien es válida en muchos sistemas, aún está incompleta. Las aplicaciones de los resultados a otros sistemas, como los flujos geofísicos, también podrían ser posibles y bastante relevantes para una amplia comunidad.[/vc_column_text][/vc_column][/vc_row][/vc_section][vc_section css=".vc_custom_1649209804184{background-color: #f6faff !important;}" el_class="p-md-0 pt-md-5"][vc_row el_class="container mx-auto align-items-center p-md-0 pt-5"][vc_column el_class="p-0"][/vc_column][/vc_row][/vc_section][vc_section css=".vc_custom_1649210787516{background-color: #f6faff !important;}" el_class="p-md-0 pt-md-5 pb-md-5"][vc_row el_class="container mx-auto align-items-center"][vc_column][/vc_column][/vc_row][/vc_section]

[vc_section el_class="container mx-auto align-items-center circle--pattern" css=".vc_custom_1648956589196{padding-top: 3rem !important;}"][vc_row el_class="pb-5"][vc_column][vc_wp_custommenu nav_menu="6"][uoh_breadcrumb_component automatic_breadcrumb="true"][uoh_title_component title_dropdown="big" title_decorator="true"]{{title}}[/uoh_title_component][vc_column_text css=""]Las ondas y las estructuras coherentes están presentes como entidades individuales en varios contextos físicos, astronómicos y geofísicos, y particularmente en los fluidos. Las situaciones realistas generalmente involucran a ambos, lo que lleva a procesos de interacción complejos que son difíciles de separar y desenredar. En esta propuesta nos enfocamos en estudiar experimentalmente cómo la presencia de estructuras coherentes, tales como vórtices o singularidades, afectan las propiedades de las ondas superficiales en un régimen turbulento. Para ello, construiremos dos montajes experimentales para poder estudiar de forma sistemática las propiedades estadísticas de las ondas cuando interactúan con las estructuras mencionadas. Ambos sistemas tienen la ventaja de que, ajustando los parámetros de forzamiento, podemos controlar la aparición e intensidad de las estructuras. Por lo tanto, un estudio sistemático de su influencia en turbulencia de ondas (WT) es sencillo. La naturaleza intermitente del campo de ondas, así como los mecanismos detrás de la ruptura del espectro de WT en presencia de estas estructuras son algunas de las preguntas que pretendemos responder. Para abordar estas preguntas, proponemos realizar mediciones espaciotemporales, como la fotografía de luz difusa (DLP) y la velocimetría de imagen de partículas (PIV). Los resultados que surjan de esta investigación podrían ser de gran importancia para una teoría que, si bien es válida en muchos sistemas, aún está incompleta. Las aplicaciones de los resultados a otros sistemas, como los flujos geofísicos, también podrían ser posibles y bastante relevantes para una amplia comunidad.[/vc_column_text][/vc_column][/vc_row][/vc_section][vc_section css=".vc_custom_1649209804184{background-color: #f6faff !important;}" el_class="p-md-0 pt-md-5"][vc_row el_class="container mx-auto align-items-center p-md-0 pt-5"][vc_column el_class="p-0"][/vc_column][/vc_row][/vc_section][vc_section css=".vc_custom_1649210787516{background-color: #f6faff !important;}" el_class="p-md-0 pt-md-5 pb-md-5"][vc_row el_class="container mx-auto align-items-center"][vc_column][/vc_column][/vc_row][/vc_section]