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- Aamodt, K., et al.
(författare)
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The ALICE experiment at the CERN LHC
- 2008
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Ingår i: Journal of Instrumentation. - 1748-0221. ; 3:S08002
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Forskningsöversikt (refereegranskat)abstract
- ALICE (A Large Ion Collider Experiment) is a general-purpose, heavy-ion detector at the CERN LHC which focuses on QCD, the strong-interaction sector of the Standard Model. It is designed to address the physics of strongly interacting matter and the quark-gluon plasma at extreme values of energy density and temperature in nucleus-nucleus collisions. Besides running with Pb ions, the physics programme includes collisions with lighter ions, lower energy running and dedicated proton-nucleus runs. ALICE will also take data with proton beams at the top LHC energy to collect reference data for the heavy-ion programme and to address several QCD topics for which ALICE is complementary to the other LHC detectors. The ALICE detector has been built by a collaboration including currently over 1000 physicists and engineers from 105 Institutes in 30 countries, Its overall dimensions are 16 x 16 x 26 m(3) with a total weight of approximately 10 000 t. The experiment consists of 18 different detector systems each with its own specific technology choice and design constraints, driven both by the physics requirements and the experimental conditions expected at LHC. The most stringent design constraint is to cope with the extreme particle multiplicity anticipated in central Pb-Pb collisions. The different subsystems were optimized to provide high-momentum resolution as well as excellent Particle Identification (PID) over a broad range in momentum, up to the highest multiplicities predicted for LHC. This will allow for comprehensive studies of hadrons, electrons, muons, and photons produced in the collision of heavy nuclei. Most detector systems are scheduled to be installed and ready for data taking by mid-2008 when the LHC is scheduled to start operation, with the exception of parts of the Photon Spectrometer (PHOS), Transition Radiation Detector (TRD) and Electro Magnetic Calorimeter (EMCal). These detectors will be completed for the high-luminosity ion run expected in 2010. This paper describes in detail the detector components as installed for the first data taking in the summer of 2008.
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- Ahlquist, Mårten, et al.
(författare)
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Product Protection, the Key to Developing High Performance Methane Selective Oxidation Catalysts
- 2009
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Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 0002-7863 .- 1520-5126. ; 131:47, s. 17110-17115
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Tidskriftsartikel (refereegranskat)abstract
- Selective, direct conversion of methane to methanol might seem an impossible task since the C-H bond energy of methane is 105 kcal mol(-1) compared to the C-H bond energy for methanol of 94. We show here that the Catalytica catalyst is successful because the methanol is protected as methyl bisulfate, which is substantially less reactive than methanol toward the catalyst. This analysis suggests a limiting performance for systems that operate by this type of protection that is well above the Catalytica system.
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- Buechner, Frederike L., et al.
(författare)
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Consumption of vegetables and fruit and the risk of bladder cancer in the European Prospective Investigation into Cancer and Nutrition
- 2009
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Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 125:11, s. 2643-2651
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Tidskriftsartikel (refereegranskat)abstract
- Previous epidemiologic studies found inconsistent associations between vegetables and fruit consumption and the risk of bladder cancer. We therefore investigated the association between vegetable and fruit consumption and the risk of bladder cancer among participants of the European Prospective Investigation into Cancer and Nutrition (EPIC) study. Data on food consumption and complete follow-up for cancer occurrence was available for a total of 478,533 participants, who were recruited in 10 European countries. Estimates of rate ratios were obtained by Cox proportional hazard models, stratified by age at recruitment, gender and study centre, and adjusted for total energy intake, smoking status, duration of smoking and lifetime intensity of smoking. A calibration study in a subsample was used to control for dietary measurement errors. After a mean follow-up of 8.7 years, 1015 participants were newly diagnosed with bladder cancer. Increments of 100 g/day in fruit and vegetable consumption combined did not affect bladder cancer risk (i.e., calibrated HR = 0.98; 95%CI: 0.95-1.01). Borderline statistically significant lower bladder cancer risks were found among fever smokers with increased consumption of fruit and vegetables combined (HR = 0.94 95%CI: 0.87-1.00 with increments of 100 g/day; calibrate HR = 0.92 95%CI 0.79-1.06) and increased consumption of apples and pears (hard fruit; calibrated HR = 0.90 95%CI: 0.82-0.98 with increments of 25 g/day). For none of the associations a statistically significant interaction with smoking status was found. Our findings do not support an effect of fruit and vegetable consumption, combined or separately, on bladder cancer risk. (c) 2009 UICC
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- Tenn, William J., III, et al.
(författare)
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Oxy-Functionalization of Nucleophilic Rhenium(I) Metal Carbon Bonds Catalyzed by Selenium(IV)
- 2009
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Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 0002-7863 .- 1520-5126. ; 131:7, s. 2466-2468
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Tidskriftsartikel (refereegranskat)abstract
- We report that SeO(2) catalyzes the facile oxy-functionalization of (CO)(5)Re(I)-Me(delta-) with IO(4)(-) to generate methanol. Mechanistic studies and DFT calculations reveal that catalysis involves methyl group transfer from Re to the electrophilic Se center followed by oxidation and subsequent reductive functionalization of the resulting CH(3)Se(VI) species. Furthermore, (CO)(3)Re(I)(Bpy)-R (R = ethyl, n-propyl, and aryl) complexes show analogous transfer to SeO(2) to generate the primary alcohols. This represents a new strategy for the oxy-functionalization of M-R(delta-) polarized bonds.
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