Electrostatic phase separation: a review

The current understanding and developments in the electrostatic phase separation are reviewed. The literature covers predominantly two immiscible and inter-dispersed liquids following the last review on the topic some 15 years. Electrocoalescence kinetics and governing parameters, such as the applied field, liquid properties, drop shape and flow, are considered. The unfavorable effects, such as chain formation and partial coalescence, are discussed in detail. Moreover, the prospects of microfluidics platforms, non-uniform fields, coalescence on the dielectric surfaces to enhance the electrocoalescence rate are also considered. In addition to the electrocoalescence in water-in-oil emulsions the research in oil-in-oil coalescence is also discussed. Finally the studies in electrocoalescer development and commercial devices are also surveyed. The analysis of the literature reveals that the use of pulsed DC and AC electric fields is preferred over constant DC fields for efficient coalescence; but the selection of the optimum field frequency a priori is still not possible and requires further research. Some recent studies have helped to clarify important aspects of the process such as partial coalescence and drop–drop non-coalescence. On the other hand, some key phenomena such as thin film breakup and chain formation are still unclear. Some designs of inline electrocoalescers have recently been proposed; however with limited success: the inadequate knowledge of the underlying physics still prevents this technology from leaving the realm of empiricism and fully developing in one based on rigorous scientific methodology

Encoding Presentation Emphasis Algorithms for Graphs

. While graphs can effectively visualize one or more relations on a set of elements, drawings of large graphs can be difficult to understand. As such, many presentation emphasis techniques for visualizing graphs such as fisheye views have been proposed. A recent survey paper [9] described an abstract space of techniques and identified common shortcomings. Here we outline a highlevel language that addresses several of these limitations; the language is used to: 1) select subsets of graph elements; 2) compute a real-valued priority for each element; and, 3) encode presentation strategies that automatically emphasize elements based on subset membership and priority. 1 Introduction Despite a growing body of literature in automatic graph drawing, one of the most pervasive obstacles for practical graph-based information systems remains the inability of user interfaces to effectively cope with large or highly detailed graphs. Aside from computational complexity issues, the fact remains that e..

A Space of Presentation Emphasis Techniques for Visualizing Graphs

The graph topo-visual formalism has been shown to be well-suited to the task of visualizing complex relations on a set of elements. Unfortunately, most visual formalisms do not scale very well. This observation is particularly true of graphs, which even when hand-drawn by an artist, are seldom meaningful when the number of nodes or links exceeds a very modest threshold -- typically only a few hundred elements. This severe limitation has prompted many researchers to seek alternative visualization techniques that may eliminate, or, at the very least, raise this threshold. In this paper we analyze these recent efforts, describe an abstract space of presentation emphasis techniques, and locate the current approaches within this space. The contributions of this paper are several: (1) a significant portion of recent work is collected and reviewed; (2) a common set of criteria and a taxonomy of graph views are proposed; these, (3) permit a more direct comparison of previous work; which helps ..

Layout-independent Fisheye Views of Nested Graphs

Although a graph can be a useful device for visualizing complex relationships, drawings of large graphs can be difficult to comprehend. As one remedy, we formulated a novel generalized approach for generating fisheye views of nested graphs with multiple variable focal points, and devised an algorithm that creates fisheye views in the absence of application specific distance metrics. Previous solutions produced fisheye views by filtering or distorting drawings of graphs. Since these approaches relied on geometric notions of distance, they could only be applied effectively in limited cases. By contrast, our approach treats fisheye view generation as a phase that precedes graph layout, rather than as a technique that alters an existing drawing, and does not suffer these drawbacks. 1 Introduction The graph topovisual formalism [6] is well-suited to the task of visualizing complex relations on a set of elements [2, 13, 15, 17, 20]. Large information spaces, however, must be depicted by lar..

Exploring Large Hyperdocuments: Fisheye Views of Nested Networks

Browsing large hypertexts by following links can be difficult and confusing, especially if links span distant nodes. Often, a user would like to explore several regions of a network simultaneously, when studying the end points of one or more links, for example. Although this can be achieved by displaying each area of interest in a separate zoomed-in window, the union of such views is not always meaningful. In particular, valuable context showing the relationships between the views is lost. By balancing local detail and global context, fisheye views display information at several levels of abstraction simultaneously. We have devised a novel technique for generating fisheye views of hierarchically nested structures with multiple variable strength focal points. In this paper we demonstrate its feasibility as a tool for exploring large nested hypertext networks. Keywords: nested hypertext networks, navigation, overviews, fisheye views. 1 Introduction Although hypertext and hypermedia sys..

Automating the generation of interactive applications

As user interfaces become more powerful and easier to use they are often harder to design and implement. This has caused a great demand for interface tools. While existing tools ease interface creation, they typically do not provide mechanisms to simplify application development and are too low-level. Furthermore, existing tools do not provide effective mechanisms to port interactive applications across user interfaces. While some tools provide limited mechanisms to port applications across user interfaces which belong to the same class (e.g., the class of all standard graphical direct-manipulation user interfaces), very few can provide the ability to port applications across different interface classes (e.g., command-line, hypermedia, speech recognition and voice synthesis, virtual reality, etc.). With my approach, the programmer uses an abstract model to describe the structure of the application including the information that the application must exchange with the user, rather than describing a user interface which realizes these characteristics. By specifying application semantics at a very high level of abstraction it is possible to obtain a much greater separation between the application and the user interface. Consequently, the resulting applications can be ported not only across user interfaces which belong to a common interface class, but across interfaces which belong to distinct classes. This can be realized through simple recompilation - source code does not have to be modified. NAAG (Not Another Application Generator), a tool which embodies these ideas, enables programmers to create interactive applications with minimal effort. An application is modelled as a set of operations which manipulate objects belonging to user-defined object classes. The input to NAAG is a source program which describes classes, operations and their inputs and outputs, and the organization of operations within the application. Classes and operations are implemented as data structures and functions in a conventional programming language such as C. This model simplifies not only the specification and generation of the user interface, but the design and implementation of the underlying application. NAAG utilizes existing technology such as macro-preprocessors, compilers, make programs, and low-level interface tools, to reduce the programming task. An application that is modified by adding, removing, or reorganizing artifacts (classes, operations, and menus), can be regenerated with a single command. Traditionally, software maintenance has been a very difficult task as well. Due to the use of a simple abstract model, NAAG applications are also easier to maintain. Furthermore, this approach encourages software reuse: applications consisting of arbitrary collections of original and pre-existing artifacts can be composed easily; functions which implement abstract operations are independent of both, user interface aspects, and the context in which they are employed. Application development is further simplified in the following ways: the programmer describes the semantics of the user interface - a conventional explicit specification is not required; output primitives are defined in an interface-independent manner; many programming tasks such as resource management, event processing, and communication, are either handled directly by the tool or else simplified greatly for the programmer. NAAG is currently used by the members of the Laboratory for Computational Vision at the University of British Columbia to maintain a sophisticated image processing system.Science, Faculty ofComputer Science, Department ofGraduat