Academic literature on the topic '2D abstract visualization'

<p><strong>Abstract.</strong> In a transformation process to become a climate-neutral city campus, universities have to deal with the sustainable concept. Since “human factor” plays a significant role in the transformation process, providing easy access to environmental data to influence building occupants’ behavior is essential. By utilizing energy-related data without spatial attribute and existing building geospatial data, data visualization in a web browser can be established for both 2D and 3D platforms. Our implementation presents a visualization of indoor sensor measurement data, where the same geospatial data can be used for both 2D and 3D visualizations even though the 3D platform needs an adjustment. Our approach results in a monitoring tool prototype based on visualization of indoor sensors measurement data, which can be accessed easily in a web browser by all building occupants.</p>

Abstract This article presents a 2D visualization of stellar spectra, obtained in Rozhen NAO.The aim is to convert one-dimensional arrays into two-dimensional images with the possibility of adjusting the degree of gray. This allows us to visualize the curves of the radial velocities and to determine their half-amplitudes even more precisely. The results of the observed stars NSVS 254037 and TYC3621-711 are presented.

Introduction: Most of recent research in the field of education strongly recommends the use of visualization in the daily teacher’s practice, especially when it comes to teaching science. Objectives: We investigated the impact of different kinds of visualization on student’s accomplishments, and the relationship between 2D and 3D visualization on the learning outcomes in biochemistry teaching, as well as gender-related differences in 2D vs 3D perception abilities. Materials and Methods: The research study was conducted on a sample of 149 senior secondary school students, devided into three groups: control group (usual teaching approach), and two experimental groups taught using different kinds of visualization: E1 (2D and 3D static visualization tools), and E2 (3D dynamic visualization tools, in addition). Discussion and results: We measured the students’ learning outcomes in biochemistry, as well as the level of satisfaction with different teaching methods. The data were interpreted by performing statistical measures and analyses. In order to validate our hypothesis, we used one-tail and two-tail ANOVA analyses (along with the t-test).Conclusions: There was no statistical significance regarding 2D vs 3D visualization tools in biochemistry teaching. Although there existed some gender-related differences in students’ achievements (in favor of females), it was not established that they were related to the type of visualization (2D or 3D) tools applied. However students from the E2 group (additional computer animations) were more interested and involved in this kind of teaching. Although the results do not show a statistical significance in favor of 3D visualization, we must conclude that in teaching biochemistry it is certainly a more efficient approach than traditional teacher-oriented lessons. By using this kind of visualization tools in everyday teaching practice, chemistry teachers are given the opportunity to enlighten students with somewhat complex and abstract biochemical concepts.

Abstract Objective Some vendors have created algorithms that generate synthetic 2D (s2D) images from a digital breast tomosynthesis (DBT) dataset to reduce the radiation from obtaining a separate 2D digital mammography (DM). This study evaluated the visibility of amorphous calcifications on 2D DM versus s2D on screening mammography. Methods This IRB-approved, retrospective, reader study included screening mammograms from 36 women who received screening DBT exams where both 2D DM and s2D images were obtained: 28 screening mammograms that were eventually given BI-RADS category 4 or 5 for amorphous calcifications and 8 BI-RADS category 1 or 2 screening exams. Two rounds of interpretation were conducted with a six-week washout period. Cases were randomized to display either the 2D DM or s2D images, which were then alternated in the second round. Four fellowship-trained breast radiologists determined whether a study merited recall for calcifications. If so, they rated calcification visibility on a scale of 1 to 5. McNemar chi-square tests were conducted to assess differences in recall rates and Wilcoxon signed rank tests were used to examine shifts in visibility. Results There was no difference in detection rates of amorphous calcifications between 2D DM and s2D, which were 75.9% and 75.0%, respectively (P = 1.000). Collectively, amorphous calcifications were more visible on s2D than 2D DM, with mean visibility scores of 3.4 versus 3.0, respectively (P = 0.005). Conclusion Synthetic 2D did not change identification of amorphous calcifications compared to 2D DM, and readers considered them more visible on average.

Visualization of characteristic equations describing guided waves The article describes the 2D and 3D visualization of characteristic equations associated with waves supported by various guided structures at microwave, mm wave, and optical wavelengths. The graphical facilities of a PC are used to ease the abstract mathematical burden that students find in such problems.

Abstract The main idea behind this work is to present three-dimensional (3D) image visualization through two-dimensional (2D) images that comprise various images. 3D image visualization is one of the essential methods for excerpting data from given pieces. The main goal of this work is to figure out the outlines of the given 3D geometric primitives in each part, and then integrate these outlines or frames to reconstruct 3D geometric primitives. The proposed technique is very useful and can be applied to many kinds of images. The experimental results showed a very good determination of the reconstructing process of 2D images.

TITLE: Assessment of hazard perception from packages shapes: a comparison of visualization methos ABSTRACT User safety could be increased by package designs that promote an adequate hazard perception. Different methodologies are available to conduct studies about the influence of package variables on users’ perceptions. This paper presents a comparative study of two visualization methods (2D vs 3D) to assess hazard perception from household packages’ shape. Household Packages, Hazard Perception, Virtual Reality

Abstract. The spread of COVID-19 has motivated a wide interest in visualization tools to represent the pandemic’s spatio-temporal evolution. This tools usually rely on dashboard environments which depict COVID-19 data as temporal series related to different indicators (number of cases, deaths) calculated for several spatial entities at different scales (countries or regions). In these tools, diagrams (line charts or histograms) display the temporal component of data, and 2D cartographic representations display the spatial distribution of data at one moment in time. In this paper, we aim at proposing novel visualization designs in order to help medical experts to detect spatio-temporal structures such as clusters of cases and spatial axes of propagation of the epidemic, through a visual analysis of detailed COVID-19 event data. In this context, we investigate and revisit two visualizations, one based on the Growth Ring Map technique and the other based on the space-time cube applied on a spatial hexagonal grid. We assess the potential of these visualizations for the visual analysis of COVID-19 event data, through two proofs of concept using synthetic cases data and web-based prototypes. The Grow Ring Map visualization appears to facilitate the identification of clusters and propagation axes in the cases distribution, while the space-time cube appears to be suited for the identification of local temporal trends.

Abstract. Urban platforms are becoming a vital role player in city resources management for achieving the right balance between social and economic services and their impact on the environment. More and more cities are starting to benefit from an urban platform to state the city conditions and re-coin the shape of life depending on data gathered from different city systems. However, urban platforms need further support of data analytics in respect of reaching a smart city platform helping city planners with better decision making. Besides, the majority of operational urban platforms consider 2D data only, missing out on the possible information that could be obtained from 3D city models. This work proposes a concept for an urban platform that supports data manipulation and visualization plus interactive analytic functionalities. As a prototype, an urban platform is implemented for integrating and processing 3D city models and 2D traffic data to derive air pollutants emission rates with analytic visualization, leading urban planning to concentrate on the most affected areas. In addition, interactive features are implemented, including filtering, querying, and classifying data to support the analytic visualization in the developed urban platform.

<p><strong>Abstract.</strong> With the rapid development of geographic information technology, the web-based 3D visualization technology is constantly updated with the development of computers. However, the traditional 3D geographic data visualization software based on the rich-client model it has significant limitations in the display and analysis of geospatial information and it is difficult to install and use, result in that difficult to meet the application of Geo-dynamic simulation, visual analysis, and collaborative decision-making of the geographic process. In order to show the realism of spatial data more directly, this paper introduces a 3D visualization process design method of geographic information and analyses the 3D data modelling building and visualization efficiency. The process combines multiple data sources are loaded automatically, cross platform, 2D &amp;amp; 3D integration, and make a wider range of customers easily access to the visualization effect of 3D spatial data.</p>

Avec le développement des technologies d’infographie, les données spatiales peuvent être mieux visualisées dans leur environnement 3D afin que les spectateurs puissent observer clairement les formes et les positions 3D. Parallèlement, les visualisations abstraites en 2D peuvent présenter des informations résumées, visualiser des données supplémentaires et contrôler la vue 3D. La combinaison de ces deux représentations en une seule interface peut aider les utilisateurs à entreprendre des tâches complexes, en particulier dans les domaines scientifiques, bien qu’il y ait un manque de directives générales de conception pour l’interaction. En général, les experts doivent analyser de volumineuses données scientifiques pour mener à bien des tâches difficiles. Par exemple, dans le domaine biologique, les biologistes doivent construire l’arbre de lignage cellulaire d’un embryon contenant plus de 200 cellules. Dans ce cas, le travail manuel peut être long et fastidieux, et les algorithmes d’apprentissage automatique ont le potentiel d’alléger certains des processus manuels fastidieux en fournissant des annotations ou prédictions initiales aux experts. Dans le cas du lignage cellulaire, ces prédictions contiennent toutefois des informations hiérarchiques et multicouches, et il est essentiel de les visualiser de manière séquentielle ou progressive. De plus, les représentations 3D et 2D, ainsi que les prédictions d’apprentissage automatique, doivent être connectées visuellement et interactivement dans le système.Dans cette thèse, le problème du lignage cellulaire des embryons de plantes a été le leitmotiv pour concevoir et étudier un système de visualisation qui utilise des combinaisons de représentations 3D et 2D ainsi que des visualisations pour l’apprentissage automatique. Nous avons d’abord étudié les techniques d’interaction pour la sélection 3D au sein d’un embryon de plante. Les cellules d’un embryon de plante sont jointives et constituent un ensemble d’objets 3D dense dans toutes les dimensions spatiales. Nous avons mené une étude pour évaluer trois techniques de sélection différentes, et nous avons montré que la combinaison de la technique de Sélection par Explosion et de la technique de Sélection par Liste fonctionne bien pour désigner et observer les cellules d’un embryon. Ces techniques peuvent égale- ment être étendues à d’autres données 3D denses et similaires. Deuxièmement, nous avons conçu un système de visualisations et d’interaction combiné afin que les biologistes puissent examiner les cellules de l’embryon et enregistrer l’histoire du développement dans l’arbre de lignage hiérarchique. Nous prenons en charge la construction de la hiérarchie dans deux directions, à la fois en construisant l’historique de haut en bas de l’arbre en utilisant la sélection lasso dans l’environnement 3D et de bas en haut selon le flux de travail traditionnel pour construire un arbre de lignage cellulaire hiérarchique. Nous avons également ajouté un modèle de réseau neuronal pour fournir aux biologistes des prédictions initiales sur les filiations. Nous avons réalisé une évaluation avec des biologistes ; celle- ci a montré que les représentations 3D et 2D facilitent les prises de décisions et que l’outil peut enrichir leur vision des embryons. Cependant, la performance du modèle d’apprentissage automatique n’était pas idéale. Aussi, pour faciliter le processus et améliorer les performances du modèle, dans une version plus aboutie de notre système, nous avons entraîné cinq modèles de classification différents, visualisé les prédictions et leurs incertitudes associées. Nous avons réalisé une évaluation auprès des utilisateurs ; les résultats ont indiqué que les représentations des classifieurs que nous avons conçues sont faciles à comprendre, et que le nouvel outil peut améliorer significativement les prises de décision pour la validation du lignage cellulaire
As computer graphics technologies develop, spatial data can be better visualized in the 3D environment so that viewers can observe 3D shapes and positions clearly. Meanwhile, 2D abs- tract visualizations can present summarized information, visualize additional data, and control the 3D view. Combining these two parts in one interface can assist people in finishing complicated tasks, especially in scientific domains, though there is a lack of design guidelines for the interaction. Generally, experts need to analyze large scientific data to finish challenging tasks. For example, in the biological field, biologists need to build the hierarchy tree for an embryo with more than 200 cells. In this case, manual work can be time- consuming and tedious, and machine learning algorithms have the potential to alleviate some of the tedious manual processes to serve as the basis for experts. These predictions, however, contain hierarchical and multi-layer information, and it is essential to visualize them sequentially and progressively so that experts can control their viewing pace and validation. Also, 3D and 2D representations, together with machine learning predictions, need to be visually and interactively connected in the system.In this thesis, we worked on the cell lineage problem for plant embryos as an example to investigate a visualization system and its interaction design that makes use of combinations of 3D and 2D representations as well as visualizations for ma- chine learning. We first investigated the 3D selection interaction techniques for the plant embryo.The cells in a plant embryo are tightly packed together, without any space in between. Traditionaltechniques can hardly deal with such an occlusion problem. We conducted a study to evaluate three different selection techniques, and found out that the combination of the Explosion Selection technique and the List Selection technique works well for people to get access and observe plant cells in an embryo. These techniques can also be extended to other similar densely packed 3D data. Second, we explored the visualization and interaction de- sign to combine the 3D visualizations of a plant embryo with its associated 2D hierarchy tree. We designed a system with such combinations for biologists to examine the plant cells and record the development history in the hierarchy tree. We support the hierarchy building in two directions, both constructing the history top-down using the lasso selection in 3D environment and bottom-up as the traditional workflow does in the hierarchy tree. We also added a neural network model to give predictions about the assignments for biologists to start with. We conducted an evaluation with biologists, which showed that both 3D and 2D representations help with making decisions, and the tool can inspire insights for them. One main drawback was that the performance of the machine learning model was not ideal. Thus, to assist the process and enhance the model performance, in an improved version of our system, we trained five different ML models and visualized the predictions and their associated uncertainty. We performed a study, and the results indicated that our designed ML representations are easy to understand, and that the new tool can effectively improve the efficiency of assigning the cell lineage

Visualizing multidimensional spatial data is an essential visual analysis strategy, it helps us interpret and communicate how different variables correlate to geographical information. In this study, we proposed an abstract contextual visualization that encodes data on the boundaries of spatial distributions and developed a new algorithm, AuroraMap. AuroraMap projects the spatial data to the boundaries of the distributions and color-encodes the densities continuously. We further conducted the user experiments, and the results show users can detect the relative locations and scopes of the clusters. Furthermore, users can quantitatively determine the peak value of each cluster’s density. The method provides three contributions: (1) freeing up and saving the graphical visualization space; (2) assisting the users to quantitatively estimate the clusters inside distributions; (3) facilitating the visual comparisons for multiple and multivariate spatial distributions. In the end, we demonstrated two applications with real-world religious infrastructural data by AuroraMap to visualize geospatial data within complex boundaries and compare multiple variables in one graph.

AbstractIn this chapter we present an accurate derivation of the distribution of scalar invariants with quadratic behavior represented as continuous histograms. The anisotropy field, computed from a two-dimensional piece-wise linear tensor field, is used as an example and is discussed in all details. Histograms visualizing an approximation of the distribution of scalar values play an important role in visualization. They are used as an interface for the design of transfer-functions for volume rendering or feature selection in interactive interfaces. While there are standard algorithms to compute continuous histograms for piece-wise linear scalar fields, they are not directly applicable to tensor invariants with non-linear, often even non-convex behavior in cells when applying linear tensor interpolation. Our derivation is based on a sub-division of the mesh in triangles that exhibit a monotonic behavior. We compare the results to a naïve approach based on linear interpolation on the original mesh or the subdivision.

Abstract This chapter describes the state-of-the-art of the potential of Digital Earth for progressively better solutions for disaster mitigation. The chapter illustrates the use of strong Digital Earth tools for data sharing and important potential for users, such as 2D or multi-D visualizations. Milestones of developments in early warning, disaster risk management and disaster risk reduction concepts are highlighted as a continuous movement between sustainable development and original concepts of disaster risk reduction. Improved solutions have been based on new research directions formulated in Sustainable Development Goals tasks and by expanding the possibilities of new effective solutions via newly organized data ecosystems generated by the United Nations Global Geospatial Information Management, the Group on Earth Observations and the Group on Earth Observations System of Systems, Copernicus and, more recently, the Digital Belt and Road initiative. The new trends in spatial big data are emphasized; the most important for disaster risk reduction are the basic theses of the U.N. Conference in Sendai. This chapter describes three aspects: innovative Digital Earth development, national and local disaster risk assessment and the benefits arising from the use of maps and dynamic data, and analyses of the contributions of cartography to disaster risk reduction.

Abstract One-dimensional (1D) systems provide examples of many of the most import- ant features of quantum mechanics, but it is also instructive to consider two-dimensional (hereafter 2D or planar) systems for several reasons:Systems with two spatial degrees of freedom provide more opportunities to study multivariable probability concepts, separation of coordinates tech- niques, and new mathematical methods and special functions. They also allow for the visualization of many quantum phenomena which arise in more real- istic three-dimensional (3D) systems, but which are obviously difficult to plot in 3D.

Abstract The three-dimensional (3D) visualization and analysis of structures is of such considerable importance to investigators in many biomedical and other disciplines that it requires no justification. A fundamental difficulty in many subjects is that the 30 structures of interest are either opaque or too small to be seen without microscopical facilities. The smallest of structures requires the use of the electron microscope, which immediately places several important constraints upon the investigator. First, only extremely small portions of a structure can be analysed. Second, only dead and biased representations of the biological structures can be studied. Third, the most likely specimen preparation to be of use is a section of sufficient thinness to allow either light or a beam of electrons to penetrate, to yield a visible image or generate a photographic negative. Such a section is variously either relatively ‘thick’ or ‘thin’ according to the dimensions of the test objects under study, which is either limited in the total amount of information it contains or possesses inherent artefacts limiting adequate visualization when examined by two dimensional (2D) microscopical techniques in which all images are essentially projections.

Abstract To visualize any new entity, a visualization should be designed and programmed. Investigating approaches for programming new scientific visualizations, we come to the following idea: utilize CinemaScience format to describe 3D scenes. CinemaScience is developed for storing and visualizing supercomputer and physical modelling results, and differs with simplicity both for human and machine. It has a set of interesting features, for example it allows to specify dynamics in views dependent on parameters. However its current known applications are of 2D graphics, and in this paper we extend it for 3D. It’s main idea is to treat Cinema artifacts as visual objects of explicit type. We successfully used the suggested approach in various visualization tasks, examples are presented in the paper. We developed the open-source web application that implements the suggested approach.

Abstract Miscible gas flooding is an effective enhanced oil recovery method, but its sweep efficiency is low due to gravity segregation and viscous fingering. This issue is worse in reservoirs with a high-level heterogeneity. Water-alternating-gas (WAG) injection is often applied to improve sweep efficiency, but with limited success. Polymer flooding is a proven approach to improve sweep efficiency. This study aims to evaluate the performance of CO2 Polymer-Altering-Gas (CO2-PAG) floods through a series of visualized experiments conducted at the lab scale. Simulations were employed to optimize the injection schedule of CO2-PAG. The experiments included continuous gas (CG), WAG, and PAG injection in 2D heterogeneous sand-packs. To visualize and understand the performance of CO2-PAG, a 2D view cell was used, and a layered heterogeneous sand-pack was constructed. During water flooding, the layer with higher permeability was highly swept and the layer with lower permeability was minimally swept. In PAG flooding, the polymer solution selectively swept the lower portion of the higher permeability layer, while the solvent predominantly swept the upper portion of the higher permeability layer. A small portion of the solvent also entered the upper part of the low permeability region. PAG flooding exhibited a higher swept area (than CG and WAG), leading to increased incremental oil recovery. However, gravity segregation remained a challenge, leaving a significant portion of the lower permeability layer upswept. The simulation results show that the injection schedule with more 5 PAG cycles had the highest incremental oil recovery. The introduction of tapering slug sizes did not significantly impact the performance of PAG. These findings provide valuable insights into optimizing the PAG process for enhanced oil recovery.

Abstract In the context of articulated robotic manipulation, reachable and dexterous workspace define regions of space that can be reached by the end-effector or tool center point (TCP) of a robot. This paper presents an approach to teaching the concepts of reachable and dexterous workspace using MATLAB animations. These methods rely on existing MATLAB tools which limit the visualization to two dimensions (2D). Despite this limitation, these tools have produced a qualitative improvement in student understanding. This paper details the visualization approach used including a review of core concepts and algorithms. Results show reachable and dexterous workspace visualizations for three degree-of-freedom (DoF), planar articulated manipulators consisting of various configurations of revolute (rotational) and prismatic (linear) joints. Source code, documentation, and installation functions for the “Visualize Workspace Toolbox” are available at https://github.com/USNA-WRCE/VisualizeWorkspaceToolbox.

Abstract Polymer flood improves the sweep efficiency of viscous oil recovery over water flood. The low-tension polymer (LTP) flood has the potential to improve the displacement efficiency due to low interfacial tension without sacrificing sweep efficiency. The objective of this research is to evaluate the performance of LTP floods as a function of IFT for a viscous oil in a 2D sand pack. Over 20 non-ionic surfactants/co-solvents were tested. A series of sandpack flooding experiments were conducted in a custom-designed 2D visualization cell. The results show that short-hydrophobic surfactants 2EH-xPO-yEO can reduce the IFT to as low as 0.05 dynes/cm. Flooding experiments were performed in sandpacks with and without connate water saturation. For the experiments with connate water saturation, the sandpack was water-wet/intermediate-wet. A base-case polymer flood (without any surfactant) with a viscosity ratio of 10 showed a stable displacement and 82% OOIP oil recovery at the first pore volume injected (PVI).LTP flood with an IFT of 0.1 dynes/cm also showed stable displacement front, but ahigher oil recovery at 1 PVI (90% OOIP).Further reduction in IFT to 0.05 dynes/cm resulted in an unstable displacement and a lower recovery of 65% OOIP. For the experiments without connate water saturation, sandpack was oil-wet, the base-case polymer flood at a viscosity ratio of 10 showed severe fingering and a low oil recovery at 1 PVI (58% OOIP). Adding the nonionic surfactants did not improve displacement efficiency nor oil recovery in oil-wet sandpacks.

Abstract This paper describes a process which is used to generate three-dimensional computer graphics surface models of gross anatomical structures. Key steps in the generation of these models include acquiring 2D cross-sectional data from macrocryotome slicing, generating 2D cross section contours from edge detection and region segmentation, generating a polygonal mesh surface model by triangulating between the 2D contours, and interactive sculpting of the 3D surface for editing and changing the appearance of the model. The algorithms and development involved with these steps are briefly described here and several images resulting from the process are presented. The main purpose of the paper is not to present the details of implementation of the various algorithms, but rather to present the overall methodology and illustrate the results. Implementation details can be found in other papers referenced here. The most recent results of our efforts, which are presented here, are 3D surface models of the complete human thorax. These models have numerous applications in anatomy and biomechanics visualization and teaching.

Abstract Rapid shape creation and visualization of solid models remains a tedious task despite advances in the field of Computer Aided Design (CAD)/Solid Modeling. CAD systems require a significant level of detail, such as vertices, edges, and faces to be specified by the user, even before the simplest of shapes can be created and viewed. In addition, most CAD systems have an essentially 2D interface for designing artifacts. This makes artifact visualization, for example by interactive rotation, difficult since all manipulations have be achieved by 2D translation of the mouse or by typing in the required angles of rotation. The limited visualization capability and the requirement to create shapes through the specification of low level entities is especially cumbersome in the concept shape design stage. This paper describes the Conceptual Virtual Design System, COVIRDS, a tool for product concept design. COVIRDS provides an intuitive voice and hand input-based interface for modeling of products using a ‘construction’ approach. Product shape models are created by ‘attaching’ simpler parametrically defined ‘Shape Elements’ to other elements to create more complex models. Voice commands are used to instantiate shape elements and change their parameters, for example, the width, length and height of a block element. 3D hand input is used for positioning shape elements during element attachment. The voice and hand input-based interface together with a stereoscopic visual display facilitates rapid creation and visualization of concept shape models.

Abstract Surfactant flooding is among the most studied and widespread EOR technologies that is being introduced into tight and low-permeable reservoirs to mobilize trapped oil. Typically, the selection of formulations for chemical flooding is associated with numerous challenges and constraints such as time-consuming core flooding tests, the high cost of the tests with modern saturation control methods, and a limited amount of core samples. To overcome these issues, microfluidic technology was applied to optimize the screening of surfactant compositions for flooding. The workflow of this project consisted of five main steps: (1) fabrication of microfluidic chips, (2) surfactant screening in bulk, (3) surfactant flooding in microfluidic chips, (4) image analysis and data interpretation. Silicon-glass microfluidic chips, which are 2D representatives of the reservoir porous media, were used in the experiments. The porous structure geometry was developed based on CT images of core samples from a particular field with low permeability. For the selected surfactants, interfacial behavior on the boundary with n-decane was studied and correlated with hydrocarbon recovery ability. The results obtained revealed that the IFT patterns have a significant influence on displacement efficiency. Thus, the surfactant compositions with a lower initial IFT than the equilibrium value achieved higher recovery factors.

Abstract Low Reynolds number flow (Re = 100) over a slitted 2D cylinder was examined to analyze the flow characteristics within the slit and the role it plays on the shedding frequency. The goal of this work is to explore the enhancement of the lift and reduction of the drag for energy harvesting purposes. One way of achieving this goal is by controlling the separation of the incompressible laminar boundary layer through blowing and suction. However, in this work it is passively controlled by the cylinder slit. Different slit orientation (azimuth angles: 0, π/12, π/6, π/4, 5π/12, and π/2) at 10% slit-to-diameter ratio was considered. The work was carried out numerically by seeking solution to the unsteady Navier-Stokes equations. Validation was done experimentally utilizing the 2D vertical soap film tunnel available in our laboratory at Khalifa University. The visualization in soap film tunnel exploits the optical properties of soap film and relies on the wake formation patterns and the frequency at which vortices shed using well developed imaging techniques. These flow visualizations of the vortex shedding behind the cylinder with and without slit were recorded and analyzed to infer its Strouhal number (St = f.D/U). From the common Roshko’s graph (Re vs St) the Reynolds number was determined, and the film property was evaluated. Using common flow as baseline the technique can be used to validate numerous 2D-flow simulations, airfoils, bluff bodies, and even the oscillating flow around them. The details of the soap-film technique and parameters for successful experimentation are provided and demonstrated on slitted cylinder. The results are validated using numerical technique and the results from the literature.

Abstract This paper introduces a novel method for playing dynamic animations of rigid body assemblies with internal motions in virtual reality (VR). Through previous research over a decade ago, an inexpensive, relatively straight-forward process has been developed that entailed using SolidWorks, MATLAB/Simulink, and movie player software to permit one to view 2D MP4 files, such as on a laptop, smart phone, etc. Inspired by the usefulness of these previous results, the approach presented here targets a VR environment, clearly representing a technological leap over viewing 2D MP4 files. It’s made possible by recent advances in VR & gaming software (e.g. Unity) along with some unique software interfacing, including use of CADLink, to permit importation of CAD files, such as from SolidWorks, into Unity. Those interested in VR visualization of their dynamic system can use the step-by-step process presented as a manual to guide them through the hardware and software setup and ultimately learn how to use SolidWorks, MATLAB/Simulink, and Unity interactively to visualize their simulations in VR. Another key point is that the analyst has considerable control and access over each step in the process, including the dynamic modeling, unlike that commonly found in large, structured dynamic simulation software packages. As an example to illustrate the process, a dynamic simulation of a classic pendulum/slider system was created using MATLAB/Simulink, which in effect numerically solves the ordinary differential equations of motion. The time-dependent displacement data for both the slider’s lateral movement and the pendulum’s angle, along with a time vector in incremental difference form, was saved as an Excel file. In turn, it was read by a C# script residing within Unity to permit an animation playback scenario of the SolidWorks CAD model of the entire pendulum/slider system (previously brought into Unity via CADLink with some reassembly), viewed more generally as an assembly with internal motions. Unity, a popular open-source piece of VR game development software used to produce both 2D and 3D video games and simulations, then serves as a platform to access the virtual world with the aid of an Oculus Rift (or Quest) VR headset and two hand controllers. In the end, the VR viewer can physically move around in the VR environment while at the same time view the playback motion of the pendulum/slider system from varying vantage points, just as one would expect in the real world. This work significantly advances the typical visualization experience with respect to dynamic system simulation & animation in addition to being widely applicable to generic mechanical assemblies.

Abstract CO2 foam holds promising potential for conformance improvement and mobility reduction of CO2 injection in fractured systems. However, there still exists two main issues hampering its wide application and development, 1. Instability of CO2 foam lamellae under reservoir conditions, and 2. Uncertainties of foam flow in fracture systems. To address these two issues, we previously developed a series of functional nanocellulose materials to stabilize the CO2 foam (referred to NCF-st-CO2 foam), while the primary goal of this paper is to thoroughly elucidate foam generation, propagation and sweep of NCF-st-CO2 foam in fractured systems by using a self-designed visual heterogeneous fracture network. We found that NCF-st-CO2 foam produced noticeably greater pressure drop (ΔP) than CO2 foam during either co-injection (COI) or surfactant solution-alternating-gas (SAG) injection, and the threshold foam quality (fg*) was approximately 0.67. Foam generation was increased with total flow rate for CO2 foam and stayed constant for NCF-st-CO2 foam in fracture during COI. CO2 breakthrough occurred at high flow rates (&gt;8 cm3/min). For SAG, large surfactant slug could prevent CO2 from early breakthrough and facilitate foaming in-situ. The increase in sweep efficiency by NCF-st-CO2 foam was observed near the producer for both COI and WAG, which was attributed to its better foaming capacity. Film division and behind mainly led to foam generation in the fracture model. Gravity segregation and override was insignificant during COI but became noticeable during SAG, which caused the sweep efficiency decreased by 3~9% at 1.0 fracture volume (FV) injected. Due to the enhanced foam film, the NCF-st-CO2 foam was able to mitigate gravitational effect, especially in the vicinity of producer.