2,237 research outputs found

    Adaptive Comparative Judgment for Polytechnic Transformation: Assessment across the Curriculum

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    The authors are investigating potential applications of adaptive comparative judgment (ACJ) across numerous environments and learning scenarios within the Purdue Polytechnic Institute as part of Purdue’s efforts to transform the undergraduate learning experience. Six courses or program areas were selectedfor the study, involving a wide variation in subjects, subject matter, and assessment artifacts. The authors anticipate that positive results from these pilot studies will encourage broader and deeper applications of ACJ in the Purdue Polytechnic, across Purdue University, and in other academic institutions. Results from these scenarios will be disseminated in future conferences and scholarly journals

    Radial Color Gradients in K+A Galaxies in Distant Clusters of Galaxies

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    Galaxies in rich clusters with z ≳\gtrsim 0.3 are observed to have a higher fraction of photometrically blue galaxies than their nearby counterparts. This raises the important question of what environmental effects can cause the termination of star formation between z β‰ˆ\approx 0.3 and the present. The star formation may be truncated due to ram-pressure stripping, or the gas in the disk may be depleted by an episode of star formation caused by some external perturbation. To help resolve this issue, surface photometry was carried out for a total of 70 early-type galaxies in the cluster Cl1358+62, at z ∼\sim 0.33, using two-color images from the Hubble Archive. The galaxies were divided into two categories based on spectroscopic criteria: 24 are type K+A (e.g., strong Balmer lines, with no visible emission lines), while the remaining 46 are in the control sample with normal spectra. Radial color profiles were produced to see if the K+A galaxies show bluer nuclei in relation to their surrounding disks. Specifically, a linear gradient was fit to the radial color profile of each galaxy. We find that the K+A galaxies on average tend to have slightly bluer gradients towards the center than the normals. A Kolmogorov-Smirnov two-sample test has been applied to the two sets of color gradients. The result of the test indicates that there is only a ∼\sim2% probability that the K+A and normal samples are drawn from the same parent distribution. There is a possible complication from a trend in the apparent magnitude vs. color gradient relation, but overall our results favor the centralized star formation scenario as an important process in the evolution of galaxies in dense clusters.Comment: 16 pages, 12 figures, accepted for publication in A

    Xcompact3D: An open-source framework for solving turbulence problems on a Cartesian mesh

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    Xcompact3D is a Fortran 90–95 open-source framework designed for fast and accurate simulations of turbulent flows, targeting CPU-based supercomputers. It is an evolution of the flow solver Incompact3D which was initially designed in France in the mid-90’s for serial processors to solve the incompressible Navier–Stokes equations. Incompact3D was then ported to parallel High Performance Computing (HPC) systems in the early 2010’s. Very recently the capabilities of Incompact3D have been extended so that it can now tackle more flow regimes (from incompressible flows to compressible flows at low Mach numbers), resulting in the design of a new user-friendly framework called Xcompact3D. The present manuscript presents an overview of Xcompact3D with a particular focus on its functionalities, its ready-to-run simulations and a few case studies to demonstrate its impact

    Answer Set Programming Modulo `Space-Time'

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    We present ASP Modulo `Space-Time', a declarative representational and computational framework to perform commonsense reasoning about regions with both spatial and temporal components. Supported are capabilities for mixed qualitative-quantitative reasoning, consistency checking, and inferring compositions of space-time relations; these capabilities combine and synergise for applications in a range of AI application areas where the processing and interpretation of spatio-temporal data is crucial. The framework and resulting system is the only general KR-based method for declaratively reasoning about the dynamics of `space-time' regions as first-class objects. We present an empirical evaluation (with scalability and robustness results), and include diverse application examples involving interpretation and control tasks

    Evolution of level density step structures from 56,57-Fe to 96,97-Mo

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    Level densities have been extracted from primary gamma spectra for 56,57-Fe and 96,97-Mo nuclei using (3-He,alpha gamma) and (3-He,3-He') reactions on 57-Fe and 97-Mo targets. The level density curves reveal step structures above the pairing gap due to the breaking of nucleon Cooper pairs. The location of the step structures in energy and their shapes arise from the interplay between single-particle energies and seniority-conserving and seniority-non-conserving interactions.Comment: 9 pages, including 5 figure

    Stacking sequences for extensionally isotropic, fully isotropic and quasi-homogeneous orthotropic laminates

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    Stacking sequence listings are presented for fully uncoupled Extensionally Isotropic (EILs), Fully Isotropic (FILs) and Quasi-Homogeneous Orthotropic (QHOLs) angle-ply Laminates, with up to 21 plies. All are sub-sets of a definitive list of Fully Orthotropic Laminates (FOLs), containing generally non-symmetric stacking sequences that are characterized in terms of angle- and cross-ply sub-sequence symmetries. Dimensionless parameters are given for each stacking sequence, from which the ABD matrix is readily derived. Expressions relating these dimensionless parameters to the well-known lamination parameters are also given, together with graphical representations of the feasible domains for Pi/3 and Pi/4 EILs and angle-ply QHOLs containing two and three ply orientations. The feasible domain for Pi/3 FILs is represented graphically by a single point, whereas the domain for angle-ply QHOLs containing four ply orientations is represented by a single stacking sequence

    Formalization of hydrocarbon conversion scheme of catalytic cracking for mathematical model development

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    The issue of improving the energy and resource efficiency of advanced petroleum processing can be solved by the development of adequate mathematical model based on physical and chemical regularities of process reactions with a high predictive potential in the advanced petroleum refining. In this work, the development of formalized hydrocarbon conversion scheme of catalytic cracking was performed using thermodynamic parameters of reaction defined by the Density Functional Theory. The list of reaction was compiled according to the results of feedstock structural-group composition definition, which was done by the n-d-m-method, the Hazelvuda method, qualitative composition of feedstock defined by gas chromatography-mass spectrometry and individual composition of catalytic cracking gasoline fraction. Formalized hydrocarbon conversion scheme of catalytic cracking will become the basis for the development of the catalytic cracking kinetic model

    Midlatitude Oceanic Cloud and Precipitation Properties as Sampled by the ARM Eastern North Atlantic Observatory

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    An edited version of this paper was published by AGU. Copyright 2019 American Geophysical Union.Marine low clouds are critical to the climate system because of their extensive coverage and associated controls on boundary layer dynamics and radiative energy balance. The primary foci for this study are marine low cloud observations over a heavily instrumented site on the Azores archipelago in the Eastern North Atlantic and their associated raindrop size distribution (DSD) properties, relative low cloud contributions to the precipitation, and additional sampling (instrument, environmental) considerations. The contribution from low clouds (e.g., cloud top < 4 km) to the overall precipitation over midlatitude oceans is poorly understood, in part because of the lack of coupled, high‐quality measurements of precipitation and low cloud properties. Cloud regime and precipitation breakdowns performed for a multiyear (2014–2017) record emphasize diurnal precipitation and raindrop size distribution characteristics for both low and deeper clouds, as well as differences between the two disdrometer types used. Results demonstrate that marine low clouds over this Eastern North Atlantic location account for a significant (45%) contribution to the total rainfall and exhibit a diurnal cycle in cloud (thickness, top, and base) and precipitation characteristics similar to satellite records. Additional controls on observed surface rainfall characteristics of low clouds allowed by the extended ground‐based facility data sets are also explored. From those analyses, it is suggested that the synoptic state exerts a significant control on low cloud and surface precipitation properties

    Large enhancement of radiative strength for soft transisitons in the quasicontinuum

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    Radiative strength functions (RSFs) for the 56,57-Fe nuclei below the separation energy are obtained from the 57-Fe(3-He,alpha gamma)56-Fe and 57-Fe(3-He,3-He' gamma)57-Fe reactions, respectively. An enhancement of more than a factor of ten over common theoretical models of the soft (E_gamma ~< 2 MeV) RSF for transitions in the quasicontinuum (several MeV above the yrast line) is observed. Two-step cascade intensities with soft primary transitions from the 56-Fe(n,2gamma)57-Fe reaction confirm the enhancement.Comment: 4 pages including 3 figure

    Isospin Character of the Pygmy Dipole Resonance in 124Sn

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    The pygmy dipole resonance has been studied in the proton-magic nucleus 124Sn with the (a,a'g) coincidence method at E=136 MeV. The comparison with results of photon-scattering experiments reveals a splitting into two components with different structure: one group of states which is excited in (a,a'g) as well as in (g,g') reactions and a group of states at higher energies which is only excited in (g,g') reactions. Calculations with the self-consistent relativistic quasiparticle time-blocking approximation and the quasiparticle phonon model are in qualitative agreement with the experimental results and predict a low-lying isoscalar component dominated by neutron-skin oscillations and a higher-lying more isovector component on the tail of the giant dipole resonance
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