[en] Sulfur dioxide pollutant was treated in the laboratory with hydrated lime particles having a mean diameter of 9.1 μm in a continuously operating binary fluidized bed reactor also containing inert sand particles with sizes varying from 500 to 590 μm. The influence of temperature (500, 600, 700 and 800 deg. C) on the reaction medium, of the superficial velocity of the gas (0.8, 1.0 and 1.2 m/s), and of the Ca/S molar ratio (1, 2 and 3) on the SO₂ removal efficiency were investigated for an inflow gas concentration of 1000 ppm and an initially static bed height of 10.0 cm. The pollutant removal efficiency proved to depend on the temperature and the velocity of the gaseous flow and was strongly influenced by the Ca/S molar ratio. The maximum efficiency of 97.7% was achieved at a temperature of 700 deg. C, a Ca/S ratio of 3 and a velocity of 0.8 m/s. The lime particles' mean residence time was determined by an indirect method, which consisted of integrating the gas concentration curves normalized with respect to time. Based on a calculation of the critical transition velocities, it was concluded that the reactor operated in a bubbling regime under each condition investigated here

[en] The authors report a case of sphenoid sinus mucocele which exhibited unusual MRI features. However a review of the literature shows that these lesions may present with different MRI appearances probably related to the variability of the cyst content. Further series are needed for a better definition of the MRI behaviour of the lesions. (orig.)

[en] A remarkable result has emerged from the first several years of data taking at RHIC--the high temperature and density phase of QCD matter created in heavy ion collisions at RHIC is best described as a near perfect fluid--the strongly interacting Quark-Gluon-Plasma (sQGP). This state is characterized by a small viscosity to entropy ratio, and a high density of color charges which induces huge energy losses of partons transversing the medium. The task for the future is to understand the characteristics of the sQGP, and perhaps more importantly--to gain some insight into how and why such a medium is created. The PHENIX detector has been one of the primary experimental tools at RHIC; in particular the electromagnetic calorimeter has been a critical component of many of the measurements leading to this discovery. The coverage of the present PHENIX electromagnetic calorimeter is rather limited, covering half the azimuth and -0.35< η <0.35 Further progress requires larger coverage of electromagnetic calorimetry, both to increase the rate for low cross section phenomena, and to cover a broader range of pseudorapidity to study the rapidity dependence of the medium. A pair of Nosecone Calorimeters (NCC) has been designed covering both positive and negative rapidity regions 1< |η| <3 of the PHENIX detector. The NCC will make it possible to perform tomographic studies of the jet energy dependence of energy loss and medium response, by using direct photons as trigger particles over a large rapidity range. The technique of correlating trigger hadrons with low momentum hadrons has been powerfully exploited at RHIC to study the evolution of back to back jets [1, 2] and hence the response of the medium. The NCC will make it possible to do such studies using direct photons as the trigger particles. The direct photon in such ''photon-jet'' events tags the transverse momentum of outgoing parton which then fragments into lower energy particles. Together with the Forward Silicon Vertex detector (FVTX), the NCC will make PHENIX a large acceptance spectrometer, capable of detecting photons, electrons, muons, and hadrons. Our prime motivation is to provide precision measurements of direct photons, π⁰s and dielectrons in A+A, p(d)+A, and polarized p+p collisions. The upgrade will provide access to physics observables that are not currently accessible to PHENIX or that are now available only indirectly with very limited accuracy

[en] Clear optical fibers were used as a Cerenkov sampling media in Pb (electromagnetic) and Cu (hadron) absorbers in spaghetti calorimeters, for high rate and high radiation dose experiments, such as the forward region of high energy colliders. The fiber axes were aligned close to the direction of the incident particles (1 degree--7 degree). The 7 λ deep hadron tower contained 2.8% by volume 1.5 mm diameter core clear plastic fibers. The 27 radiation length deep electromagnetic towers had packing fractions of 6.8% and 7.2% of 1 mm diameter core quartz fibers as the active Cerenkov sampling medium. The energy resolution on electrons and pions, energy response, pulse shapes and angular studies are presented

[en] The TEC/TRD subsystem will track all charged particles and contribute to the particle identification by the measurement of energy loss. The design, construction and testing of the TEC chambers are described

[en] A Hadron Blind Detector (HBD) has been developed, constructed and successfully operated within the PHENIX detector at RHIC. The HBD is a Cherenkov detector operated with pure CF₄. It has a 50 cm long radiator directly coupled in a windowless configuration to a readout element consisting of a triple GEM stack, with a CsI photocathode evaporated on the top surface of the top GEM and pad readout at the bottom of the stack. This paper gives a comprehensive account of the construction, operation and in-beam performance of the detector.

[en] The PHENIX experiment at RHIC has measured the invariant cross section for ω-meson production at midrapidity in the transverse momentum range 2.5< p_T<9.25 GeV/c in p+p and d+Au collisions at √(s_NN)=200 GeV. Measurements in two decay channels (ω→π⁰π⁺π^- and ω→π⁰γ) yield consistent results, and the reconstructed ω mass agrees with the accepted value within the p_T range of the measurements. The ω/π⁰ ratio is found to be 0.85±0.05^stat±0.09^sys in p+p and 0.94±0.08^stat±0.12^sys in d+Au collisions, independent of p_T. The nuclear modification factor R_dA^ω is 1.03±0.12^stat±0.21^sys and 0.83±0.21^stat±0.17^sys in minimum bias and central (0-20%) d+Au collisions, respectively

[en] The properties of jets produced in p+p collisions at √(s)=200 GeV are measured using the method of two-particle correlations. The trigger particle is a leading particle from a large transverse momentum jet while the associated particle comes from either the same jet or the away-side jet. Analysis of the angular width of the near-side peak in the correlation function determines the jet-fragmentation transverse momentum j_T. The extracted value, √(< j_T²>)=585±6(stat)±15(sys) MeV/c, is constant with respect to the trigger particle transverse momentum, and comparable to the previous lower √(s) measurements. The width of the away-side peak is shown to be a convolution of j_T with the fragmentation variable, z, and the partonic transverse momentum, k_T. The < z> is determined through a combined analysis of the measured π⁰ inclusive and associated spectra using jet-fragmentation functions measured in e⁺e^- collisions. The final extracted values of k_T are then determined to also be independent of the trigger particle transverse momentum, over the range measured, with value of √(< k_T²>)=2.68±0.07(stat)±0.34(sys) GeV/c

[en] We present transverse momentum (p_T) spectra of charged hadrons measured in deuteron-gold and nucleon-gold collisions at √(s_NN)=200 GeV for four centrality classes. Nucleon-gold collisions were selected by tagging events in which a spectator nucleon was observed in one of two forward rapidity detectors. The spectra and yields were investigated as a function of the number of binary nucleon-nucleon collisions, ν, suffered by deuteron nucleons. A comparison of charged particle yields to those in p+p collisions show that yield per nucleon-nucleon collision saturates with ν for high momentum particles. We also present the charged hadron to neutral pion ratios as a function of p_T

[en] PHENIX has measured the centrality dependence of midrapidity pion, kaon, and proton transverse momentum distributions in d+Au and p+p collisions at √(s_NN)=200 GeV. The p+p data provide a reference for nuclear effects in d+Au and previously measured Au+Au collisions. Hadron production is enhanced in d+Au, relative to independent nucleon-nucleon scattering, as was observed in lower energy collisions. The nuclear modification factor for (anti)protons is larger than that for pions. The difference increases with centrality but is not sufficient to account for the abundance of baryon production observed in central Au+Au collisions at the BNL Relativistic Heavy Ion Collider (RHIC). The centrality dependence in d+Au shows that the nuclear modification factor increases gradually with the number of collisions encountered by each participant nucleon. We also present comparisons with lower energy data as well as with parton recombination and other theoretical models of nuclear effects on particle production