Structure of shock compressed model basaltic glass: Insights from O K-edge X-ray Raman scattering and high-resolution ^(27)Al NMR spectroscopy

The detailed atomic structures of shock compressed basaltic glasses are not well understood. Here, we explore the structures of shock compressed silicate glass with a diopside–anorthite eutectic composition (Di_(64)An_(36)), a common Fe-free model basaltic composition, using oxygen K-edge X-ray Raman scattering and high- resolution ^(27)Al solid-state NMR spectroscopy and report previously unknown details of shock-induced changes in the atomic configurations. A topologically driven densification of the Di_(64)An_(36) glass is indicated by the increase in oxygen K-edge energy for the glass upon shock compression. The first experimental evidence of the increase in the fraction of highly coordinated Al in shock compressed glass is found in the ^(27)Al NMR spectra. This unambiguous evidence of shock-induced changes in Al coordination environments provides atomistic insights into shock compression in basaltic glasses and allows us to microscopically constrain the magnitude of impact events or relevant processes involving natural basalts on Earth and planetary surfaces

What\u27s Going Wrong in Nevada? A Comparative Analysis of California and Nevada Gun Control Laws as They Relate to Gun Violence

The recent mass shooting on October 1, 2017 in Las Vegas, Nevada has been marked in history as the worst mass shooting in the United States to this point. The details of the shooting beg the question, is it coincidence that it happened in Nevada, a state with some of the least restrictive gun control laws? Mass shootings have become an unfortunate part of reality in the United States, but these are fairly uncommon occurrences. While they are horrific and deserve attention, daily gun violence cannot be forgotten. In the face of such a multitude of gun violence, what can be done to prevent future violence from occurring? This paper compares Nevada and California, two states that are geographically similar, but could not be more different when it comes to gun control. The paper draws connections between state gun control laws and gun violence trends in an attempt to determine what the best course of action is for addressing the problem

Accessibility evaluation of chats and forums in e-learning environments

Proceedings of: 2013 International Conference on Frontiers in Education: Computer Science & Computer Engineering (FECS'13): WORLDCOMP'13, July 22-25, 2013, Las Vegas, Nevada (USA)Collaborative learning is useful for students in their learning process. Nowadays, most e-learning systems include Computer Supported Collaborative Learning (CSCL) tools like chats and forums; however, are they accessible for everybody? This paper presents a heuristic evaluation of accessibility of two CSCL tools (chat and forum) in four web-based, open-source Learning Content Management Systems (LCMS): Moodle, ATutor, dotLRN and Claroline. The evaluation results show that the CSCL tools evaluated present accessibility barriers which are a handicap for many students who want to use the LCMSs Moreover, some recommendations are offered in order to improve the accessibility of the evaluated tools. Considering these recommendations in the development of the evaluated tools, all students could participate actively in the collaborative tasks proposed by teachersThis research work has been supported by the Regional Government of Madrid under the Research Network MA2VICMR (S2009/TIC-1542) and by the Spanish Ministry of Economy under the project MULTIMEDICA (TIN2010-20644-C03-01)Publicad

Surface Hydrologic Modeling and Analyzing Watershed Hydrologic Response to Landcover Change

Urban flooding is the most frequently occurring disaster in rapidly urbanizing cities. Rapid urbanization in general, is characterized by an increase in the total impervious surface area, which means less soil cover for the stormwater to infiltrate and a greater volume of runoff from the area in case of a storm event. This increased volume of surface runoff, if not drained, results in urban flooding. Urban flooding can cause serious economic and environmental damages by disrupting transportation and spreading pollution. It is therefore, essential to understand the cause, behavior and effects of urban flooding so as to minimize the risks and costs associated with urban floods. Hydrologic models are useful tools for understanding hydrologic processes and for designing urban stormwater drainage infrastructure to reduce the risks of floodings. This research aims to study urban hydrology by estimating surface runoff from an urban area using an event based distributed parameter hydrologic model. In this research, an event-based distributed parameter hydrologic model is developed, which uses Green-Ampt infiltration model to estimate the surface runoff from a given catchment. The developed model is tested on two small catchments. The ‘rainfall-runoff modeling’ part of the developed model is calibrated for the rainfall events of May 22, 2017 and, May 24, 2017 over the Moores Run study area, and, validated for the rainfall event of April 17, 2017. The ‘flood-modeling’ part of the developed model is validated for the rainfall event of Sep 11, 2012 over the Parking-lots area at UNLV. The results of the rainfall-runoff simulation and flood depth and extent estimation for different land-cover change scenarios over the Parking-lots catchment is also provided. The testing on Moores Run study area resulted in calibration at 30-m resolution DEM and a hydraulic conductivity value of 0.19 cm/hr. for soil group D. The error in the model’s estimation of the catchment area is 7.75%. The model over-predicted the runoff volume from the catchment for the first rainfall event while under-predicted the runoff volume from the catchment for the second rainfall event. The average error in estimation of the runoff volume is 1.8%. The model also over-predicts the ‘time-to-peak’ and under-predicts ‘peak runoff’ in both cases. The average of RMSE between the predicted hydrograph and actual hydrograph for the two rainfall events is 0.0071 m3/s in calibration, and, 0.011 m3/s in validation. The testing on UNLV Parking-lots area resulted in calibration at 10-m resolution DEM. For the rainfall event of Sep 11, 2012, the model predicts over predicts the peak flood depth and under-predicts the maximum extent of flooding. The error in flood depth estimation is found be 12.9%. From watershed hydrologic response to landcover change analysis, it is observed that Manning’s roughness coefficient doesn’t affect the total volume of runoff, however, the time to peak is significantly delayed for landcover with higher values of Manning’s roughness co-efficient. This research provides an insight into surface hydrologic modeling. It also provides an overview of calibration against DEM resolution and hydraulic conductivity values. Finally, it provides an understanding of watershed hydrologic response to different landcovers with various Manning’s roughness values

Novel mechanism for evaluating feedback in the grid environment on resource allocation

The primary concern in proffering an infrastructure for general purpose computational grids formation is security. Grid implementations have been devised to deal with the security concerns. The chief factors that can be problematic in the secured selection of grid resources are the wide range of selection and the high degree of strangeness. Moreover, the lack of a higher degree of confidence relationship is likely to prevent efficient resource allocation and utilization. In this paper, we propose an efficient approach for the secured selection of grid resources, so as to achieve secure execution of the jobs. The presented approach utilizes trust and reputation for securely selecting the grid resources by also evaluation user’s feedback on the basis of the feedback already available about the entities. The proposed approach is scalable for an increased number of resources

Finite Difference Modeling of Surface-~Wave Scattering for Shallow Cavity Detection

Data collection and analysis of scattering of Rayleigh-type surface waves are investigated for locating shallowly buried cavities. Surface-based seismic experiments conducted by others at the University of Nevada, Las Vegas (UNLV) Engineering Geophysics Test Site (EGTS) demonstrate scattering of Rayleigh waves caused by buried empty barrels (essentially air-filled cavities). The interpretation of the data is complicated by factors such as the presence of a high-velocity geologic layer just below the cavity. This research uses a finite-difference seismic wave propagation code to compute time histories for a model that represents the Engineering Geophysics Test Site. By adding cavities to a background model, the time histories show scattering of surface waves due to the cavity. Complications in the wave train are caused by the high velocity layer. Starting by modeling a through-going cavity in an otherwise homogeneous soil model allows for identification of essential characteristics of time histories that reveal the presence of the cavity. The same homogeneous model without a cavity serves as a baseline to compare time histories and their frequency content. Layers are added and cavity length is reduced to create a more realistic model for comparing synthetic data with experimental data. This research compares experimental data to synthetic data in the forms of time histories, overtone images, and stacks of overtone images. The stacks of overtone images succeed for complex situations where the other approaches fail. Comparing the synthetic data from the model that represents the EGTS, using a convolved real source, to the experimental data from the EGTS, the stacks of overtone images demonstrate similarities. Variations in amplitude mark the locations of the cavities in both cases. Power spectrums and a cavity characterization parameter proposed by others are also studied for their capacity to indicate the presence and location of the cavities

Discovery of Kangite, (Sc,Ti,Al,Zr,Mg,Ca)_2O_3, A New Ultra-Refractory Mineral in Allende

During a nano-mineralogy investigation of the Allende CV3 carbonaceous chondrite, we identified a new scandia mineral named "kangite" in an irregular ultra-refractory inclusion. It has a cubic Ia3 bixbyite-type structure and a formula unit (Sc,Ti,Al,Zr,Mg,Ca,)_2P_3. Field-emission SEM with EDS and electron back-scatter diffraction, electron microprobe and synchrotron micro-Laue diffraction were used to characterize the composition and structure. We report here the first occurrence of kangite in nature, as a new ultra-refractory oxide among the earliest solids formed in the solar nebula, and discuss its origin and significance for nebular processes. The mineral and the mineral name (kangite) have been approved by the Commission on New Minerals, Nomenclature and Classification of the International Mineralogical Association (IMA 2011-092)

Use of the gLite-WMS in CMS for production and analysis

The CMS experiment at LHC started using the Resource Broker (by the EDG and LCG projects) to submit Monte Carlo production and analysis jobs to distributed computing resources of the WLCG infrastructure over 6 years ago. Since 2006 the gLite Workload Management System (WMS) and Logging \& Bookkeeping (LB) are used. The interaction with the gLite-WMS/LB happens through the CMS production and analysis frameworks, respectively ProdAgent and CRAB, through a common component, BOSSLite. The important improvements recently made in the gLite-WMS/LB as well as in the CMS tools and the intrinsic independence of different WMS/LB instances allow CMS to reach the stability and scalability needed for LHC operations. In particular the use of a multi-threaded approach in BOSSLite allowed to increase the scalability of the systems significantly. In this work we present the operational set up of CMS production and analysis based on the gLite-WMS and the performances obtained in the past data challenges and in the daily Monte Carlo productions and user analysis usage in the experiment

Air Force Institute of Technology Research Report 2011

This report summarizes the research activities of the Air Force Institute of Technology’s Graduate School of Engineering and Management. It describes research interests and faculty expertise; lists student theses/dissertations; identifies research sponsors and contributions; and outlines the procedures for contacting the school. Included in the report are: faculty publications, conference presentations, consultations, and funded research projects. Research was conducted in the areas of Aeronautical and Astronautical Engineering, Electrical Engineering and Electro-Optics, Computer Engineering and Computer Science, Systems and Engineering Management, Operational Sciences, Mathematics, Statistics and Engineering Physics

Air Force Institute of Technology Research Report 2009

This report summarizes the research activities of the Air Force Institute of Technology’s Graduate School of Engineering and Management. It describes research interests and faculty expertise; lists student theses/dissertations; identifies research sponsors and contributions; and outlines the procedures for contacting the school. Included in the report are: faculty publications, conference presentations, consultations, and funded research projects. Research was conducted in the areas of Aeronautical and Astronautical Engineering, Electrical Engineering and Electro-Optics, Computer Engineering and Computer Science, Systems and Engineering Management, Operational Sciences, Mathematics, Statistics and Engineering Physics