ABSTRACT
We investigate the impact of clouds on the atmosphere of GJ 1214b using the radiatively coupled, phase-equilibrium cloud model EddySed coupled to the Unified Model general circulation model. ...We find that, consistent with previous investigations, high metallicity (100 × solar) and clouds with large vertical extents (a sedimentation factor of fsed = 0.1) are required to best match the observations, although metallicities even higher than those investigated here may be required to improve agreement further. We additionally find that in our case which best matches the observations (fsed = 0.1), the velocity structures change relative to the clear sky case with the formation of a superrotating jet being suppressed, although further investigation is required to understand the cause of the suppression. The increase in cloud extent with fsed results in a cooler planet due to a higher albedo, causing the atmosphere to contract. This also results in a reduced day–night contrast seen in the phase curves, although the introduction of cloud still results in a reduction of the phase offset. We additionally investigate the impact the Unified Model’s pseudo-spherical irradiation scheme on the calculation of heating rates, finding that the introduction of nightside shortwave heating results in slower mid-latitude jets compared to the plane-parallel irradiation scheme used in previous works. We also consider the impact of a gamma distribution, as opposed to a lognormal distribution, for the distribution of cloud particle radii and find the impact to be relatively minor.
This communication presents a compact leaky-wave antenna providing circular polarization from a dual-mode hollow waveguide (WG). The monolithic structure is based on a rectangular metallic guide that ...is perforated with crossed slots. The antenna is fed by a standard WR42 port, which is connected to the leaky WG by a transition that allows for dual-mode excitation. The axial ratio (AR) is determined by the size of the WG section and the dimensions of the crosses. In order to preserve the polarization purity, the geometry of the first radiating elements is modulated. Designed at <inline-formula> <tex-math notation="LaTeX">K </tex-math></inline-formula>-band, the present proposal is suitable for space applications since it relies on a full-metal structure. A design methodology is proposed based on the dual-mode dispersion analysis. Selective laser melting is used to monolithically 3-D print the antenna. Measurements are in good agreement with simulations and the AR is 0.92 dB at 20.5 GHz.
A fully reconfigurable dual linearly-polarized phase-shifting unit-cell for reflectarrays is proposed in X-band. It consists of two orthogonal and symmetrical cross-type printed triangular dipoles ...loaded by 2 × 4 pin diodes. To keep independent phase responses both in vertical and horizontal polarizations and to minimize cross-polarization (by preserving the cell symmetry), the diodes are driven by pairs, leading to a maximum possible phase resolution of 2 bits per polarization. Two alternative solutions are described to bias the diode pairs. The corresponding phase responses of the unit-cell are compared for symmetrical and non-symmetrical diode loading of the dipole arms. The numerical results show that the biasing solution with no central via is more robust. They are validated experimentally around 8 GHz. The measured average loss and equivalent bit resolution at the central frequency equal 1.25 dB and 1.8 bit respectively.
This work shows how it is possible to reconstruct SuperKEKB’s beam parameters using a Neural Network with beamstrahlung signal from the Large Angle Beamstrahlung Monitor (LABM) as input. We describe ...the device, the model, and discuss the results.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
This study proposes a new approach to flatten retrodirective corner reflectors. The proposed method enables compact reflectors via Transformation Optics (TO) combined with Surface Impedance ...Modulation (SIM). This combination permits to relax the constraints on the anisotropic material resulting from the TO. Phase gradient approach is generalized to be used within anisotropic media and is implemented with SIM. Different reflector setups are designed, simulated and compared for fop = 8GHz using ANSYS® HFSS® in order to validate the use of such a combination.
(S)-α-ethyl-2-oxopyrrolidine acetamide 2 (levetiracetam, Keppra, UCB S.A.), a structural analogue of piracetam, has recently been approved as an add-on treatment of refractory partial onset seizures ...in adults. This drug appears to combine significant efficacy and high tolerability due to a unique mechanism of action. The latter relates to a brain-specific binding site for 2 (LBS for levetiracetam binding site) that probably plays a major role in its antiepileptic properties. Using this novel molecular target, we initiated a drug-discovery program searching for ligands with significant affinity to LBS with the aim to characterize their therapeutic potential in epilepsy and other central nervous system diseases. We systematically investigated the various positions of the pyrrolidone acetamide scaffold. We found that (i) the carboxamide moiety on 2 is essential for affinity; (ii) among 100 different side chains, the preferred substitution α to the carboxamide is an ethyl group with the (S)-configuration; (iii) the 2-oxopyrrolidine ring is preferred over piperidine analogues or acyclic compounds; (iv) substitution of positions 3 or 5 of the lactam ring decreases the LBS affinity; and (v) 4-substitution of the lactam ring by small hydrophobic groups improves the in vitro and in vivo potency. Six interesting candidates substituted in the 4-position have been shown to be more potent antiseizure agents in vivo than 2 . Further pharmacological studies from our group led to the selection of (2S)-2-(4R)-2-oxo-4-propylpyrrolidin-1-ylbutanamide 83 α (ucb 34714) as the most interesting candidate. It is approximately 10 times more potent than 2 as an antiseizure agent in audiogenic seizure-prone mice. A clinical phase I program has been successfully concluded and 83 α will commence several phase II trials during 2003.
A simple but general modelling of a floating high-frequency surface wave radar is presented. It deals with moving antenna systems and assesses the negative effects of antenna motion on the ...first-order Bragg lines. The various canonical types of movements are considered and simulation results are successfully compared with more specific models or measured data. A realistic configuration supported by the experimental results is also addressed.
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