Sensors, Vol. 16, Pages 1249: Comparative Study of Two Different TiO2 Film Sensors on Response to H2 under UV Light and Room Temperature

An anatase TiO2 film sensor was prepared by a facile in-situ method on the interdigitated Au electrode deposited on the alumina substrate. The structure, morphology and the optical properties of the in-situ TiO2 film sensor were characterized by X-ray diffraction, Scanning Electron Microscopy, and UV-vis diffuse reflectance spectra. The photo-assisted gas sensitivities of the prepared film towards H2 gas were evaluated at room temperature in N2 and synthetic air atmospheres. As compared to TiO2 film sensor prepared by drop-coating method, this in-situ TiO2 film sensor exhibited a more compact structure composed of uniform TiO2 microspheres as well as a better gas sensitivity towards H2 under UV irradiation, especially in synthetic air. The photo-electrochemical measurements suggest that these improvements may be associated with the efficient charge transfer in the TiO2 interface induced by the TiO2 microsphere structure. This study might offer a feasible approach to develop photo-assisted gas sensors at ambient temperature.

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Sustainability, Vol. 8, Pages 767: Research of Sustainable Use of Tire Shreds in Landfill

Studies are on-going to establish the suitability of tire shreds in the landfill bottom drainage layer, to minimize clogging. Four experimental columns were constructed in which were 500 mm long and 200 mm in diameter. They were filled with different fillers and with a different amount of tire shreds. The most important problem with drainage filler in landfills is clogging. Over long periods of time in landfill operation, the drainage layer clogs (the pores of the layer become smaller and the porosity of the layer becomes smaller). The experiment was carried out for 365 days. Although the landfill for this period represents only one-fiftieth or less of the operation time, the laboratory tests found that the drainage layer bandwidth of reduction in one year can have a negative impact in the long run over time. The main elements that influence the decrease of conductivity are the total suspended solids and calcium and iron compounds. The change of these compounds was observed during the column study, where the concentration of each month in all the columns was decreasing. The results showed that the waste of rubber (tire shreds) used for creating fillers in columns provided greater porosity of the layer. It is a beneficial reason to use a rubble and tire shreds waste mix for forming the drainage layer in landfills.

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Mathematics, Vol. 4, Pages 50: Complete Classification of Cylindrically Symmetric Static Spacetimes and the Corresponding Conservation Laws

In this paper we find the Noether symmetries of the Lagrangian of cylindrically symmetric static spacetimes. Using this approach we recover all cylindrically symmetric static spacetimes appeared in the classification by isometries and homotheties. We give different classes of cylindrically symmetric static spacetimes along with the Noether symmetries of the corresponding Lagrangians and conservation laws.

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IJGI, Vol. 5, Pages 139: Spatiotemporal Modeling of Urban Growth Predictions Based on Driving Force Factors in Five Saudi Arabian Cities

This paper investigates the effect of four driving forces, including elevation, slope, distance to drainage and distance to major roads, on urban expansion in five Saudi Arabian cities: Riyadh, Jeddah, Makkah, Al-Taif and Eastern Area. The prediction of urban probabilities in the selected cities based on the four driving forces is generated using a logistic regression model for two time periods of urban change in 1985 and 2014. The validation of the model was tested using two approaches. The first approach was a quantitative analysis by using the Relative Operating Characteristic (ROC) method. The second approach was a qualitative analysis in which the probable urban growth maps based on urban changes in 1985 is used to test the performance of the model to predict the probable urban growth after 2014 by comparing the probable maps of 1985 and the actual urban growth of 2014. The results indicate that the prediction model of 2014 provides a reliable and consistent prediction based on the performance of 1985. The analysis of driving forces shows variable effects over time. Variables such as elevation, slope and road distance had significant effects on the selected cities. However, distance to major roads was the factor with the most impact to determine the urban form in all five cites in both 1985 and 2014.

http://ift.tt/2aUe7BA

IJGI, Vol. 5, Pages 138: Occlusion-Free Visualization of Important Geographic Features in 3D Urban Environments

Modern cities are dense with very tall buildings, which often leads to features of interest (FOIs, e.g., relevant roads and associated landmarks) being occluded by clusters of buildings. Thus, from any given point of view, users can see only a small area of the city. However, it is currently an important technical problem to maintain the visibility of FOIs while preserving the urban shapes and spatial relationships between features. In this paper, we present a novel automatic visualization method to generate occlusion-free views for FOIs in real time. Our method integrates with three effective cartographic schemes: route broadening, building displacement, and building scaling, using an optimization framework A series of distortion energies are presented to preserve the urban resemblance, considering the view position and the urban features based on spatial cognition to maintain spatial and temporal coherence. Our approach can be used to visualize large urban environments at interactive framerates in which the visibility of the occluded FOIs is maximized while the deformation of the landscape's shape is minimized. Using this approach, the visual readability of such 3D urban maps can be much improved.

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Life, Vol. 6, Pages 32: Ultra Large Gene Families: A Matter of Adaptation or Genomic Parasites?

Gene duplication is an important mechanism of molecular evolution. It offers a fast track to modification, diversification, redundancy or rescue of gene function. However, duplication may also be neutral or (slightly) deleterious, and often ends in pseudo-geneisation. Here, we investigate the phylogenetic distribution of ultra large gene families on long and short evolutionary time scales. In particular, we focus on a family of NACHT-domain and leucine-rich-repeat-containing (NLR)-genes, which we previously found in large numbers to occupy one chromosome arm of the zebrafish genome. We were interested to see whether such a tight clustering is characteristic for ultra large gene families. Our data reconfirm that most gene family inflations are lineage-specific, but we can only identify very few gene clusters. Based on our observations we hypothesise that, beyond a certain size threshold, ultra large gene families continue to proliferate in a mechanism we term "run-away evolution". This process might ultimately lead to the failure of genomic integrity and drive species to extinction.

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JMSE, Vol. 4, Pages 46: Application of a Spectral Wave Model to Assess Breakwater Configurations at a Small Craft Harbour on Lake Ontario

A surface wave model using three nested grids is applied to the eastern end of Lake Ontario to investigate wave propagation from an open lake environment to a small craft harbour protected by a breakwater. The Simulating WAves Nearshore (SWAN) spectral wave model, coupled with the Delft3D hydrodynamic model, is applied to simulate a series of storms in November, 2013. The model results are compared to observations from two pressure sensors, and used to quantify wave properties around existing and future breakwaters to evaluate the bulk changes to the harbour configuration. Overall, the results indicate that the rubblemound breakwater reduces wave heights in the existing harbour by 63% compared to no breakwater, and that the addition of a surface breakwater extension could reduce wave heights by an additional 54%. Wave height attenuation was found to be highly dependent on the incident wave direction relative to breakwater orientation. The spectral wave model is useful for simulating wave transformation for broad directional spectra in wind-sea conditions over large scales to semi-protected areas such as small craft harbours.

http://ift.tt/2aTs5oW