Northern Illinois University

About: Northern Illinois University is a education organization based out in DeKalb, Illinois, United States. It is known for research contribution in the topics: Large Hadron Collider & Population. The organization has 8818 authors who have published 20008 publications receiving 632341 citations. The organization is also known as: NIU.

A dependence of J/ psi and psi ' production at 800 GeV/c.

Abstract: The yield of {ital J}/{psi} and {psi}{prime} vector-meson states has been measured for 800-GeV protons incident on deuterium, carbon, calcium, iron, and tungsten targets. A depletion of the yield per nucleon from heavy nuclei is observed for both {ital J}/{psi} and {psi}{prime} production. This depletion exhibits a strong dependence on {ital x}{sub {ital F}} and {ital p}{sub {ital t}}. Within experimental errors the depletion is the same for the {ital J}/{psi} and the {psi}{prime}.

Teacher attitudes toward mainstreaming: a cross‐cultural study in six nations

Abstract: Attitudes of teachers toward the educational mainstreaming of special needs students in six nations ‐ the United States, Germany, Israel, Ghana, Taiwan, and the Philippines ‐ were compared Also investigated were teacher background variables associated with attitudes toward integration Findings revealed that the most supportive views were expressed by teachers in the United States followed by educators in Germany Attitudes of teachers in the other nations represented mainly a neutral disposition toward mainstreaming The lowest attitude scores were obtained for Israeli non‐kibbutz educators Several variables were associated with attitudes: training in special education, grade level, age, teaching experience, and experience with individuals who are disabled The role that teacher preparation programs and effective mainstreaming practices have in the development of teacher support for integration are discussed

Supporting Efficient Execution in Heterogeneous Distributed Computing Environments with Cactus and Globus

Abstract: Improvements in the performance of processors and networks make it both feasible and interesting to treat collections of workstations, servers, clusters, and supercomputers as integrated computational resources, or Grids. However, the highly heterogeneous and dynamic nature of such Grids can make application development difficult. Here we describe an architecture and prototype implementation for a Grid-enabled computational framework based on Cactus, the MPICH-G2 Grid-enabled message-passing library, and a variety of specialized features to support efficient execution in Grid environments. We have used this framework to perform record-setting computations in numerical relativity, running across four supercomputers and achieving scaling of 88% (1140 CPU's) and 63% (1500 CPUs). The problem size we were able to compute was about five times larger than any other previous run. Further, we introduce and demonstrate adaptive methods that automatically adjust computational parameters during run time, to increase dramatically the efficiency of a distributed Grid simulation, without modification of the application and without any knowledge of the underlying network connecting the distributed computers.

Measurement of inclusive jet and dijet cross sections in proton-proton collisions at 7 TeV centre-of-mass energy with the ATLAS detector

Abstract: Jet cross sections have been measured for the first time in proton-proton collisions at a centre-of-mass energy of 7 TeV using the ATLAS detector. The measurement uses an integrated luminosity of 17 nb-1 recorded at the Large Hadron Collider. The anti-kt algorithm is used to identify jets, with two jet resolution parameters, R = 0.4 and 0.6. The dominant uncertainty comes from the jet energy scale, which is determined to within 7% for central jets above 60 GeV transverse momentum. Inclusive single-jet differential cross sections are presented as functions of jet transverse momentum and rapidity. Dijet cross sections are presented as functions of dijet mass and the angular variable $\chi$. The results are compared to expectations based on next-to-leading-order QCD, which agree with the data, providing a validation of the theory in a new kinematic regime.

Pressure Tuning of the Spin-Orbit Coupled Ground State in Sr2IrO4

Abstract: X-ray absorption spectroscopy studies of the magnetic-insulating ground state of ${\mathrm{Sr}}_{2}{\mathrm{IrO}}_{4}$ at ambient pressure show a clear deviation from a strong spin-orbit (SO) limit ${J}_{\mathrm{eff}}=\frac{1}{2}$ state, a result of local exchange interactions and a nonzero tetragonal crystal field mixing SO split ${J}_{\mathrm{eff}}=\frac{1}{2}$, $\frac{3}{2}$ states. X-ray magnetic circular dichroism measurements in a diamond anvil cell show a magnetic transition at a pressure of $\ensuremath{\sim}17\text{ }\text{ }\mathrm{GPa}$, where the ``weak'' ferromagnetic moment is quenched despite transport measurements showing insulating behavior to at least 40 GPa. The magnetic transition has implications for the origin of the insulating gap and the nature of exchange interactions in this SO coupled system. The expectation value of the angular part of the SO interaction, $⟨\mathbf{L}\ifmmode\cdot\else\textperiodcentered\fi{}\mathbf{S}⟩$, extrapolates to zero at $\ensuremath{\sim}80--90\text{ }\text{ }\mathrm{GPa}$ where an increased bandwidth strongly mixes ${J}_{\mathrm{eff}}=\frac{1}{2}$, $\frac{3}{2}$ states and SO interactions no longer dominate the electronic ground state of ${\mathrm{Sr}}_{2}{\mathrm{IrO}}_{4}$.