569 research outputs found
Payload crew interface design criteria and techniques. Task 1: Inflight operations and training for payloads
Guidelines are developed for use in control and display panel design for payload operations performed on the aft flight deck of the orbiter. Preliminary payload procedures are defined. Crew operational concepts are developed. Payloads selected for operational simulations were the shuttle UV optical telescope (SUOT), the deep sky UV survey telescope (DUST), and the shuttle UV stellar spectrograph (SUSS). The advanced technology laboratory payload consisting of 11 experiments was selected for a detailed evaluation because of the availability of operational data and its operational complexity
Oxygen and carbon dioxide effects on the photosynthetic and photorespiratory carbon pools in Glycine max
PSI-ECRIT(S): a hybrid magnetic system with a mirror ratio of 10 for H-like heavy ion production and trapping
At the Paul Scherrer Institut ( PSI, Switzerland) an experimental program is started to measure the ground state shift and width of pionic hydrogen. To calibrate the crystal spectrometer X-ray transitions in hydrogen-like heavy ions (e.g. Ar17+) produced by ECR ion sources, are necessary. In PSI a superconducting cyclotron trap magnet originally developed for high energy experiments will be transformed into an ECR Ion Trap (ECRIT). The SC-magnet can deliver more than 4 Tesla magnetic fields with a mirror ratio of 2. A careful calculation showed this mirror ratio can be increased upto 10 and the trap can operate with frequencies between 5 and 20 GHz. To form a closed resonance zone a relatively large open structure (LBL-AECRU-type) NdFeB hexapole will be applied. The first tests will be performed with 6.4 GHz. Later higher frequencies (10 or 14.5 GHz) and the 2-frequency heating (6.4+10, 6.4+14.5 or 10+14.5) are planned to be applied to get enough quantity of H-like heavy ions. Since the main goal of this machine is to be a trap no extraction is necessary. However, for the fine-tuning of the plasma for very high charge states might require ion charge state spectrums to be analyzed. If this is the case a simple beamline at negative potential will be built. The present paper shows the results of the magnetic system calculations in details and summarises the present state of the ECRIT(S) overall design
Symmetry-breaking in chiral polymerisation
We propose a model for chiral polymerisation and investigate its symmetric
and asymmetric solutions. The model has a source species which decays into
left- and right-handed types of monomer, each of which can polymerise to form
homochiral chains; these chains are susceptible to `poisoning' by the opposite
handed monomer. Homochiral polymers are assumed to influence the proportion of
each type of monomer formed from the precursor. We show that for certain
parameter values a positive feedback mechanism makes the symmetric steady-state
solution unstable. The kinetics of polymer formation are then analysed in the
case where the system starts from zero concentrations of monomer and chains. We
show that following a long induction time, extremely large concentrations of
polymers are formed for a short time, during this time an asymmetry introduced
into the system by a random external perturbation may be massively amplified.
The system then approaches one of the steady-state solutions described above.Comment: 26pages, 6 Figure
Ion Behavior and Gas Mixing in electron cyclotron resonance plasmas as sources of highly charged ions (concept
Operation of the GTS-LHC Source for the Hadron Injector at CERN
The GTS-LHC ion source, designed and build by CEA Grenoble, was installed and commissioned at CERN in 2005. Since than the source has delivered oxygen and lead ion beams (O4+ and Pb27+ from the source, Pb54+ from the linac) for the commissioning of the Low Energy Ion Ring (LEIR). Results of this operation and attempts to improve the source performance and reliability, and the linac performance will be presented in this paper
Situs inversus totalis in a fetus with a deletion at 7q36.2 detected on microarray analysis
Laterality disorders are a heterogeneous group of disorders associated with maternal diseases (maternal IDDM), maternal exposures to teratogens (retinoic acid), chromosome abnormalities and single gene disorders (ZIC3 mutation). We report on a fetus with a submicroscopic deletion at 7q36.2 with right atrial isomerism (RAI). CASE: The mother was a 30y G4P1SA2L1 and the father was 35y. Both were healthy and non-consanguineous and their family history was non-contributory. They had a healthy son and daughter and had two miscarriages. MSS was negative. Detailed fetal U/S and echocardiography at 20w showed: RAI with ...postprin
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