Drops with non-circular footprints

In this paper we study the morphology of drops formed on partially wetting substrates, whose footprint is not circular. This type of drops is a consequence of the breakup processes occurring in thin films when anisotropic contact line motions take place. The anisotropy is basically due to hysteresis effects of the contact angle since some parts of the contact line are wetting, while others are dewetting. Here, we obtain a peculiar drop shape from the rupture of a long liquid filament sitting on a solid substrate, and analyze its shape and contact angles by means of goniometric and refractive techniques. We also find a non--trivial steady state solution for the drop shape within the long wave approximation (lubrication theory), and compare most of its features with experimental data. This solution is presented both in Cartesian and polar coordinates, whose constants must be determined by a certain group of measured parameters. Besides, we obtain the dynamics of the drop generation from numerical simulations of the full Navier--Stokes equation, where we emulate the hysteretic effects with an appropriate spatial distribution of the static contact angle over the substrate

Análisis petro-elástico de velocidades P y S en muestras de la formación Vaca Muerta

La formación Vaca Muerta es una de las principales rocas madre en la cuenca Neuquina, la que durante los últimos años ha cobrado gran notoriedad y relevancia como reservorio para la producción de hidrocarburos no convencionales. La misma está constituida por sedimentitas marinas tipo shales, denominadas margas bituminosas, debido a su alto contenido de materia orgánica. Con el fin de lograr una completa caracterización de estos reservorios, la empresa YPF realizó a partir de 2010 estudios petrofísicos, mineralógicos, geoquímicos, geomecánicos y ultrasónicos sobre un conjunto de muestras de tal formación, extraídas a partir de testigos de pozos. Asimismo, efectuaron análisis PVT para la tipificación de los fluidos del reservorio a la temperatura y presión in situ. La integración de tal conjunto de datos para la calibración de modelos de física de rocas apropiados para estos ambientes constituye la principal motivación de este trabajo. Esta temática ha despertado el interés de numerosos autores quienes han propuesto diversos modelos físicos y workflows para respresentar el comportamiento elástico de estos medios, los que por lo general exhiben anisotropía transversal. Los diferentes modelos tienen el fin de relacionar los parámetros de interés en estos ambientes con las magnitudes observables, tales como velocidades sísmicas, densidad, impedancias elásticas y reflectividades. En el presente trabajo se testean diferentes teorías de medios elásticos y poroelásticos efectivos, integrando la información disponible a los modelos. Considerando la hipótesis de isotropía como primer aproximación, el objetivo consistirá en comparar el grado de ajuste de las velocidades medidas en laboratorio sobre un conjunto de muestras seleccionadas (correspondientes a un mismo pozo), para los diferentes modelos. Como resultado de este análisis se espera correlacionar los errores resultantes de las distintas aproximaciones con la fracción orgánica y de arcillas de las distintas muestras. Asimismo, se analizará la factibilidad de establecer un valor de porosidad crítica razonable para el intervalo en estudio.Eje: Geofísica Aplicada y Ambiental.Facultad de Ciencias Astronómicas y Geofísica

Acoustic and mechanical response of reservoir rocks under variable saturation and effective pressure

We investigate the acoustic and mechanical properties of a reservoir sandstone saturated by two immiscible hydrocarbon fluids, under different saturations and pressure conditions. The modeling of static and dynamic deformation processes in porous rocks saturated by immiscible fluids depends on many parameters such as, for instance, porosity, permeability, pore fluid, fluid saturation, fluid pressures, capillary pressure, and effective stress. We use a formulation based on an extension of Biot's theory, which allows us to compute the coefficients of the stress-strain relations and the equations of motion in terms of the properties of the single phases at the in situ conditions. The dry-rock moduli are obtained from laboratory measurements for variable confining pressures. We obtain the bulk compressibilities, the effective pressure, and the ultrasonic phase velocities and quality factors for different saturations and pore-fluid pressures ranging from normal to abnormally high values. The objective is to relate the seismic and ultrasonic velocity and attenuation to the microstructural properties and pressure conditions of the reservoir. The problem has an application in the field of seismic exploration for predicting pore-fluid pressures and saturation regimes

The role of agency in the emergence and development of social innovations in rural areas. Analysis of two cases of social farming in Italy and the Netherlands

Social innovation is considered a relevant concept to tackle societal challenges and needs in rural areas and to promote smart, inclusive and sustainable growth. The characterising sector of rural areas is agriculture; therefore, the focus of this paper is on social innovation in the field of social farming. Among the many factors leading to the emergence and development of social innovation, agency has been considered relevant in the literature on transformability and transformative social innovation as it is the ability to turn contextual difficulties into opportunities for social innovation and for inclusive growth. This paper proposes an evaluation framework to assess the different dimensions of agency by triangulating quantitative with qualitative data and by using indicators. This paper adopts a case study approach, analysing two cases of social farming in Italy and the Netherlands. The results show that the social innovation idea and the resilience of the agency are among the most relevant dimensions for the emergence and development of social innovations. Finally, this paper discusses the three most relevant factors for agency to lead to social innovation: idea and embeddedness of the agency, transformability of the context through agencys resilience, and agency as catalyst for empowerment

CAPILLARY IMBIBITION TECHNIQUES USED TO CHARACTERIZE THESTRUCTURAL CHANGES IN MICROCRYSTALLINE CELLULOSE DUE TO WET AND DRY PROCESS

In this work we study the change on the wettability and solid properties of microcrystalline cellulose (Avicel PH101)after it was wet and dried, through drop penetration experiments in slightly compacted porous beds. We perform these experiments with water and a silicone oil, (Polidimethilsyloxane–PDMS) and we determine a dimensionless parameter that takes into account all the water penetration factors, including wettability and swelling. We consider three different scenarios, original MCC, and after one and two wetting and drying cycles. For each case we study the particle size effects by considering two subset samples SiA)25<φ<75μm and SiB)75<φ<125μm. We were able to determine, as it was expected, that PDMS penetration dynamics is not affected by the wetting–drying cycles but water is. The penetration rate goes down after cellulose was wet. Finally, we discuss how these behavior may affect the different processes where microcrystalline cellulose is used

PULSATILE FLOW OF VISCOELASTIC FLUIDS IN TUBES

In this study, we present an experimental investigation of the flow structure changes in non-Newtonian fluids subjected to periodic variable fluxes inside rigid-walled tubes. We employ a liquid mixture composed of water and polyacrylamide to account for various rheological properties. We obtain the velocity fields for each experimental case using the Particle Image Velocimetry (PIV) technique and we analyze their variations based on different properties of the pulsatile input signal. Reynolds numbers between 200 and 350 are considered, with a 10 % variation in amplitude

Evaluating the Impact of an Integrated Urban Design of Transport Infrastructure and Public Space on Human Behavior and Environmental Quality: A Case Study in Beijing

Urban transport infrastructure can result in the physical, psychological and environmental separation of neighborhoods, public spaces and pedestrian networks, leading to negative impacts on citizens’ daily commutes, social activities and the quality of the ecosystem. An integrated design of transport infrastructure and public space is beneficial for mediating these negative impacts. In this paper, we propose an integrated methodology, which combines urban design, computational scenario evaluation and decision-making processes, based on a conceptual model of human and ecological needs-driven planning. To evaluate the impacts of the road network and public space design on individual outdoor activities, travel behavior and air pollution, an agent-based model is demonstrated. This model is then applied to a case study in Beijing, leading to hourly traffic volume maps and car-related air pollution heat maps of a baseline road network-public space design

Questioning Mountain Rural Commons in Changing Alpine Regions. An Exploratory Study in Trentino, Italy

Most of rural resources in the Italian mountain territories, such as forests, pastures, huts, mountain paths, have historically been governed through collective organizations and institutions that have guaranteed the balance between productive activities and environmental protection. These systems can be framed according to the literature on commons. Although the model of collective resource management is still strongly rooted in the Alpine region, socioeconomic changes underway call into question the way resources are conceived, used and managed by communities and the very concept of community as a reference for a collective resource. Few studies have focused on the transformation and adaptation of commons to the changes taking place, such as the progressive penetration of global economic and demographic megatrends at the local level, with the aim of decoding the new tension between community needs and societal needs. By referring to the concepts of resilience and transformability of social-ecological systems, this paper aims to reflect on the impact of the socioeconomic transformations underway in mountain rural regions, to search for new approaches for the conceptualization of commons and to investigate how commons can be transformed in order to make them resilient and more socially inclusive. For that, an extensive literature review and an exploratory fieldwork using a case study approach have been performed. The paper´s results are exploratory, from which working hypotheses have been derived to be explored in further studies. These hypotheses relate to socio-economic and cultural practices as well as approaches that would enable the re-embedding of the commons in the economy and society undergoing change