LOCALIS: Locally-adaptive Line Simplification for GPU-based Geographic Vector Data Visualization

Visualization of large vector line data is a core task in geographic and cartographic systems. Vector maps are often displayed at different cartographic generalization levels, traditionally by using several discrete levels-of-detail (LODs). This limits the generalization levels to a fixed and predefined set of LODs, and generally does not support smooth LOD transitions. However, fast GPUs and novel line rendering techniques can be exploited to integrate dynamic vector map LOD management into GPU-based algorithms for locally-adaptive line simplification and real-time rendering. We propose a new technique that interactively visualizes large line vector datasets at variable LODs. It is based on the Douglas-Peucker line simplification principle, generating an exhaustive set of line segments whose specific subsets represent the lines at any variable LOD. At run time, an appropriate and view-dependent error metric supports screen-space adaptive LOD levels and the display of the correct subset of line segments accordingly. Our implementation shows that we can simplify and display large line datasets interactively. We can successfully apply line style patterns, dynamic LOD selection lenses, and anti-aliasing techniques to our line rendering

CO2-selective, Hybrid Membranes by Silation of Alumina

Hybrid membranes are feasible candidates for the separation of CO2 from gas produced in coal-based power generation since they have the potential to combine the high selectivity of polymer membranes and the high permeability of inorganic membranes. An interesting method for producing hybrid membranes is the silation of an inorganic membrane. In this method, trichloro- or alkoxy-silanes interact with hydroxyl groups on the surface of γ-AlO3 or TiO2, binding organic groups to that surface. By varying the length of these organic groups on the organosilane, it should be possible to tailor the effective pore size of the membrane. Similarly, the addition of “CO2-phillic” groups to the silating agent allows for the careful control of surface affinity and the enhancement of surface diffusion mechanisms. This method of producing hybrid membranes selective to CO2 was first attempted by Hyun [1] who silated TiO2 with phenyltriethoxysilane. Later, Way [2] silated γ-AlO3 with octadecyltrichlorosilane. Both researchers were successful in producing membranes with improved selectivity toward CO2, but permeability was not maintained at a commercially applicable level. XPS data indicated that the silating agent did not penetrate into the membrane pores and separation actually occurred in a thin “polymer-like” surface layer. The present study attempts to overcome the mass transfer problems associated with this technique by producing the desired monolayer coverage of silane, and thus develop a highly-permeable CO2-selective hybrid membrane

High power TiO2 and high capacity Sn-doped TiO2 nanomaterial anodes for lithium-ion batteries

A range of phase-pure anatase TiO2 (∼5 nm) and Sn-doped TiO2 nanoparticles with the formula Ti1-xSnxO2 (where x = 0, 0.06, 0.11 and 0.15) were synthesized using a continuous hydrothermal flow synthesis (CHFS) reactor. Charge/discharge cycling tests were carried out in two different potential ranges of 3 to 1 V and also a wider range of 3 to 0.05 V vs Li/Li+. In the narrower potential range, the undoped TiO2 nanoparticles display superior electrochemical performance to all the Sn-doped titania crystallites. In the wider potential range, the Sn-doped samples perform better than undoped TiO2. The sample with composition Ti0.85Sn0.15O2, shows a capacity of ca. 350 mAh g−1 at an applied constant current of 100 mA g−1 and a capacity of 192.3 mAh g−1 at a current rate of 1500 mA g−1. After 500 charge/discharge cycles (at a high constant current rate of 382 mA g−1), the same nanomaterial anode retains a relatively high specific capacity of 240 mAh g−1. The performance of these nanomaterials is notable, particularly as they are processed into electrodes, directly from the CHFS process (after drying) without any post-synthesis heat-treatment, and they are made without any conductive surface coating

Design of a multiuser virtual trade fair using a game engine

The current world economic situation makes it necessary to develop new ways of establishing commercial relationships. One possible solution is to explore the advantages of virtual worlds, and for this reason online virtual trade fairs are becoming more popular in the business world. They enable companies to establish a trade relationship with their customers without the need to visit them in person. This is very attractive for exhibitors because it can save them money, which is a priority for many companies today. In this line, this article presents a multiuser virtual trade fair developed using 3D game engine technologys. Users represented by avatars can interact with each other while they are visiting the virtual fair, which has some interactive objects included in the stands to provide information about the exhibitors. This virtual world is accessible online, and visitors only require a plug-in on their computers to be able to enter the virtual world. The game technology makes it possible to obtain a high degree of realism: very real lighting, cast shadows, collision detection, etc. Moreover, the virtual world presented builds the 3D objects automatically. Participants in the trade fair can customize their virtual stand and the application will generate the code necessary for its inclusion in the rendered virtual world.This work was supported by the Spanish Ministry of Science and Technology project TIN2010-21089-C03-03. And also by Bancaja, project P1 1B2007-5

Loss of Prestin Does Not Alter the Development of Auditory Cortical Dendritic Spines

Disturbance of sensory input during development can have disastrous effects on the development of sensory cortical areas. To examine how moderate perturbations of hearing can impact the development of primary auditory cortex, we examined markers of excitatory synapses in mice who lacked prestin, a protein responsible for somatic electromotility of cochlear outer hair cells. While auditory brain stem responses of these mice show an approximately 40 dB increase in threshold, we found that loss of prestin produced no changes in spine density or morphological characteristics on apical dendrites of cortical layer 5 pyramidal neurons. PSD-95 immunostaining also showed no changes in overall excitatory synapse density. Surprisingly, behavioral assessments of auditory function using the acoustic startle response showed only modest changes in prestin KO animals. These results suggest that moderate developmental hearing deficits produce minor changes in the excitatory connectivity of layer 5 neurons of primary auditory cortex and surprisingly mild auditory behavioral deficits in the startle response

Development of Practical Supported Ionic Liquid Membranes: A Systematic Approach

Supported liquid membranes (SLMs) are a class of materials that allow the researcher to utilize the wealth of knowledge available on liquid properties to optimize membrane performance. These membranes also have the advantage of liquid phase diffusivities, which are higher than those observed in polymers and grant proportionally greater permeabilities. The primary shortcoming of the supported liquid membranes demonstrated in past research has been the lack of stability caused by volatilization of the transport liquid. Ionic liquids, which may possess high CO2 solubility relative to light gases such as H2, are excellent candidates for this type of membrane since they are stable at elevated temperatures and have negligible vapor pressure. A study has been conducted evaluating the use of a variety of ionic liquids in supported ionic liquid membranes for the capture of CO2 from streams containing H2. In a joint project, researchers at the University of Notre Dame synthesized and characterized ionic liquids, and researchers at the National Energy Technology Laboratory incorporated candidate ionic liquids into supports and evaluated membrane performance for the resulting materials. Several steps have been taken in the development of practical supported ionic liquid membranes. Proof-of-concept was established by showing that ionic liquids could be used as the transport media in SLMs. Results showed that ionic liquids are suitable media for gas transport, but the preferred polymeric supports were not stable at temperatures above 135oC. The use of cross-linked nylon66 supports was found to produce membranes mechanically stable at temperatures exceeding 300oC but CO2/H2 selectivity was poor. An ionic liquid whose selectivity does not decrease with increasing temperature was needed, and a functionalized ionic liquid that complexes with CO2 was used. An increase in CO2/H2 selectivity with increasing temperature over the range of 37 to 85oC was observed and the dominance of a facilitated transport mechanism established. The presentation will detail membrane development, the effect of increasing transmembrane pressure, and preliminary results dealing with other gas pairs and contaminants

Search for the Lepton-Number-Violating Decay Ξ−→pμ−μ−\Xi^- \to p \mu^- \mu^-

A sensitive search for the lepton-number-violating decay $\Xi^-\to p \mu^-\mu^-$ has been performed using a sample of $\sim10^9$ $\Xi^-$ hyperons produced in 800 GeV/$c$ $p$-Cu collisions. We obtain $\mathcal{B}(\Xi^-\to p \mu^-\mu^-)< 4.0\times 10^{-8}$ at 90% confidence, improving on the best previous limit by four orders of magnitude.Comment: 9 pages, 5 figures, to be published in Phys. Rev. Let

An approach to convert vertex-based 3D representations to combinatorial B-splines for real-time visual collaboration

Scientific Visualization and Virtual Reality are increasingly being used for the design of complex systems. These technologies offer powerful capabilities to make decisions that are cost and time effective. The next logical extension is to collaborate with these visual models in real-time, where parts of a design team are geographically separated. Specifically, visual collaboration enables ideas and proposed changes to be discussed exactly on a virtual model of a product. However, high-end visualization hardware and Internet technologies impede widespread use of real-time visual collaboration due to the large amount of data from which these representations are created. These data are typically in the form of 3D vertex-based models, which offer a high degree of realism when displayed, but at a price of storage, rendering speeds and processing efficiency. The more realistic the representation desired, the larger the number of vertices required and hence the higher the file size. In this paper, we propose a new data modeling and handling technique where traditional vertex-based models are converted into combinatorial B-Spline based wire-frame models that allow realtime visual collaboration in the context of typical virtual reality systems. Using appropriate filtering methods, parametric equations are computed for each curved segment in a vertexbased representation and bundled together with sampled linear segments of the model. The computed parametric equation based models occupy only a fraction of the size when compared to the original vertex-based models. These lightweight models can easily be transmitted over the Internet, in real-time, for viewing with a platform independent visual client program. The proposed methods were tested on several example data files to prove the method’s effectiveness