The simulation software for the ATLAS Experiment at the Large Hadron Collider is being used for largescale production of events on the LHC Computing Grid. This simulation requires many components, from the generators that simulate particle collisions, through packages simulating the response of the various detectors and triggers. All of these components come together under the AT-LAS simulation infrastructure. In this paper, that infrastructure is discussed, including that supporting the detector description, interfacing the event generation, and combining the GEANT4 simulation of the response of the individual detectors. Also described are the tools allowing the software validation, performance testing, and the validation of the simulated output against known physics processes.

The χ(b)(nP) quarkonium states are produced in proton-proton collisions at the Large Hadron Collider at sqrt[s] = 7  TeV and recorded by the ATLAS detector. Using a data sample corresponding to an integrated luminosity of 4.4  fb(-1), these states are reconstructed through their radiative decays to Υ(1S,2S) with Υ → μ+ μ-. In addition to the mass peaks corresponding to the decay modes χ(b)(1P,2P) → Υ(1S)γ, a new structure centered at a mass of 10.530 ± 0.005(stat) ± 0.009(syst)  GeV is also observed, in both the Υ(1S)γ and Υ(2S)γ decay modes. This structure is interpreted as the χ(b)(3P) system.

Both high ionic conductivity and selectivity of a membrane are required for efficient salinity gradient energy conversion. An efficient method to improve energy conversion is to align ionic transport along the membrane thickness to address low ionic conductivity in traditional membranes used for energy harvesting. We fabricated a free-standing covalent organic framework membrane (TpPa-SO 3 H) with excellent stability and mechanical properties. This membrane with onedimensional nanochannels and high charge density demonstrated high ionic conductivity and selectivity. Its power density reached up to 5.9 W m À2 by mixing artificial seawater and river water. Based on our results, we attribute the high energy conversion to the high ion conductivity through aligned onedimensional nanochannels and high ion selectivity via the size of the nanochannel at % 1 nm in the membrane. This study paves the way for designing covalent organic framework membranes for high salinity gradient energy conversion.