Fluid trapping during capillary displacement in fractures

International audienceThe spatial distribution of fluid phases and the geometry of fluid-fluid interfaces resulting from immiscible displacement in fractures cast decisive influence on a range of macroscopic flow parameters. Most importantly, these are the relative permeabilities of the fluids as well as the macroscopic irreducible saturations. They also influence parameters for component (solute) transport, as it usually occurs through one of the fluid phase only. Here, we present a numerical investigation on the critical role of aperture variation and spatial correlation on fluid trapping and the morphology of fluid phase distributions in a geological fracture. We consider drainage in the capillary dominated regime. The correlation scale, that is, the scale over which the two facing fracture walls are matched, varies among the investigated geometries between L/256 and L (self-affine fields), L being the domain/fracture length. The aperture variability is quantified by the coefficient of variation (δ), ranging among the various geometries from 0.05 to 0.25. We use an invasion percolation based model which has been shown to properly reproduce displacement patterns observed in previous experiments. We present a quantitative analysis of the size distribution of trapped fluid clusters. We show that when the in-plane curvature is considered, the amount of trapped fluid mass first increases with increasing correlation scale Lc and then decreases as Lc further increases from some intermediate scale towards the domain length scale L. The in-plane curvature contributes to smoothening the invasion front and to dampening the entrapment of fluid clusters of a certain size range that depends on the combination of random aperture standard deviation and spatial correlation

Axiosphere of Social Advertising Poster about Coronavirus in Russia and China

The axiogenic situation of the pandemic is considered based on the material of social advertising of two countries — Russia and China. The thesis is advanced that the coronavirus pandemic can be considered as a referent that allows a value-marked interpretation. The purpose of the work is to identify a set of universal values objectified in social advertising; characterize verbal and visual codes as means of expressing valuable meanings; determine national specifics of advertising.400 Russian and Chinese advertising texts served as the material for the observations. As a result of the analysis, it was revealed that the axiological space of advertising of both countries is constructed by a set of valuable meanings, united by the absolute value of being — the concept of LIFE. It is noted that the structure of advertising discourse is based on the dichotomy of biological and social. The key value, along with life and its protection, was the strength of unity and cohesion of the nation in the face of a mortal threat. The value of the heroic is objectified in the image of medical workers. It was revealed that Chinese advertising is characterized by a language game associated with homonymy and the transformation of phraseological units, and the absence of weakly creolized texts with a strong cultural and historical component of the visual series. It is concluded that Russian advertising revives the style of the Soviet poster when promoting sanitary and hygienic rules

Molecular insights into structural and dynamic properties of water molecules in calcium silicate hydrate nanopores: The roles of pore size and temperature

Calcium silicate hydrate is the primary hydration product of Portland cement and plays a crucial role in determining the strength of cement-based materials. The structural and dynamic properties of water molecules within calcium silicate hydrate nanopores have significant implications for the mechanical and durability performance of these materials. However, the influences of pore size and temperature on the properties of water molecules have not been fully explored. In this work, using molecular dynamics simulations and theoretical analysis, the evolution and mechanisms of the structural and dynamic properties of water molecules in different scenarios with various pore sizes and temperatures are systematically investigated. It is shown that the diffusion coefficients of water molecules increase with both pore size and temperature. Moreover, water molecules have a tendency to adsorb onto calcium silicate hydrate substrates, forming a distinct layered structure. As a result, the water molecules near the surfaces of calcium silicate hydrate substrates exhibit limited mobility, leading to smaller diffusion coefficients compared to those in other regions. Additionally, the distinctions in properties between water molecules and Ca2+ ions are elucidated and the underlying mechanisms behind these differences are also unveiled. The results and findings in this work deepen the understanding of structural and dynamic properties of water molecules within calcium silicate hydrate nanopores, providing valuable insights for improving the mechanical and durability performance of cement-based materials.Document Type: Original articleCited as: Liu, S., A, H., Tang, S., Kai, M., Yang, Z. Molecular insights into structural and dynamic properties of water molecules in Calcium silicate hydrate nanopores: The roles of pore size and temperature. Capillarity, 2023, 8(2): 23-33. https://doi.org/10.46690/capi.2023.08.0

Wide Viewing Angle Transflective Liquid Crystal Display.

Apparatus, methods and systems for a transmissive liquid crystal display including a plurality of pixel circuits, each pixel circuit including a reflective region and a transmissive region. The reflective region includes a polarization dependent reflector for reflecting ambient light. The reflective and transmissive regions include an initially homogeneously aligned liquid crystal layer sandwiched between a first and a second substrate. Each pixel further includes at lease one first transparent electrode as the common electrode and at least one second transparent electrode as the pixel electrode both formed on one of the same first and second substrates, wherein substantial fringe fields with rich horizontal electric fields are generated in the liquid crystal layer when voltage is applied to the pixel electrode, making the liquid crystal molecules rotate mainly in the horizontal direction to achieve wide viewing angle

Liquid Crystal Display

A display includes pixel circuits, each pixel circuit including a first electrode, a second electrode, a third electrode, and a liquid crystal layer doped with a chiral material. The first electric is electrically coupled to a first reference voltage. The second electrode receives a pixel voltage corresponding to a gray scale level, the second electrode including a conducting layer having openings. The third electrode is electrically coupled to a second reference voltage. The second electrode is between the first and third electrodes, and the liquid crystal layer is between the first and second electrodes

Transflective Liquid Crystal Display Comprising A Dielectric Layer Between The First And Second Electrodes In The Transmissive Region

A display includes a plurality of pixel circuits, each pixel circuit including a first electrode, a second electrode, a reflective region, and a transmissive region. The reflective region reflects ambient light and includes a first portion of a liquid crystal layer and a polarization dependent reflector. The transmissive region transmits backlight and includes a second portion of the liquid crystal layer. A dielectric layer is between the first and second electrodes in one of the reflective region and the transmissive region, the dielectric layer configured such that when a pixel voltage is applied to the first and second electrodes, the percentage of the pixel voltage applied across the first portion of the liquid crystal layer is different from the percentage of the pixel voltage applied across the second portion of the liquid crystal layer. The display includes a backlight module to generate the backlight

An injectable scaffold based on crosslinked hyaluronic acid gel for tissue regeneration

An injectable scaffold of crosslinked hyaluronic acid gel for tissue regeneration.</p

Transflective LCD with Reflective Layer Connected to Reference Voltage Greater than 0.5 VRMS and Less than LC Threshold Voltage

A transflective display includes pixels each including a first electrode, a second electrode, a liquid crystal layer associated with the first and second electrodes, and a conductive reflective layer between the liquid crystal layer and the second electrode to reflect ambient light. The conductive reflective layer is insulated from the second electrode and covers less than all of the second electrode to allow backlight to be transmitted through a portion of the pixel not covered by the conductive reflective layer

The impact of resilience on the mental health of military personnel during the COVID-19 pandemic: coping styles and regulatory focus

Military personnel encountered multiple stressful events during the COVID-19 lockdown. Reducing non-combat attrition due to mental disorders is crucial for military morale and combat effectiveness. Grounded in stress theory and regulatory focus theory, this study investigates the influence of resilience on military personnel’s mental health; coping style and regulatory focus are considered potential mediators and moderators, respectively. We conducted a routine psychological assessment on 1,110 military personnel in China. The results indicate that: (1) resilience has a negative impact on the psychological symptoms of military groups; (2) mature and mixed coping styles in military personnel mediate the association between resilience and psychological symptoms; and (3) regulatory focus predominance has a negative moderating effect on mature coping styles’ effects on psychological symptoms. Furthermore, this study supports previous findings that resilience and mental health are interrelated; it demonstrates that military personnel can effectively reduce negative psychological symptoms by improving their resilience level and adopting mature coping styles under stressful situations. The current study presents interventional insights regarding coping styles and mental health from a self-regulatory perspective during the COVID-19 pandemic