Design of Compact Planar Diplexer Based on Novel Spiral-Based Resonators

A miniaturized planar diplexer utilizing the novel spiral-based resonators is proposed. The given cell which is initially proposed in this article is composed of two separated rectangular spirals which are asymmetrical to each other and thus, it is called as ‘asymmetrical separated spirals resonator’ (ASSR). ASSR has more superior transmission property than the previous prototype and extremely compact dimension is also achieved. It is demonstrated that ASSR can exhibit bandpass performance with high frequency selectivity and good transmission property within the relatively low frequency band. Based on the given characteristic, one planar diplexer composed of T-junction and two ASSRs is synthesized and the fabricated prototype with compact dimension is achieved, thanks to ASSRs explored. Simultaneously, the transversal dimension of each channel is extremely compact because ASSRs are completely embedded in the feed lines. Both the simulated and measured results indicate that satisfactory impedance matching and high isolation between two channels are achieved. Furthermore, the proposed diplexer is uniplanar and no defected ground structure is introduced

Bis[3-allyl-1-(4-cyanobenzyl)-2-methylbenzimidazolium] di-μ-bromido-bis[bromidocuprate(I)]

The asymmetric unit of the title compound, (C19H18N3)2[Cu2Br4], contains one cation and one half-anion; there is a centre of symmetry mid-way between the two Cu atoms. In the cation, the nearly planar benzimidazole ring system is oriented at dihedral angles of 75.31 (3) and 21.39 (3)° with respect to the cyano­benzyl and allyl groups, respectively. The dihedral angle between cyano­benzyl and allyl groups is 87.94 (3)°. In the crystal structure, inter­molecular C—H⋯Br hydrogen bonds link the mol­ecules. There is a C—H⋯π contact between the cyano­benzyl ring and the anion; π—π contacts also exist between the benzimidazole ring systems as well as between the anion and the cyano­benzyl ring [centroid–centroid distances = 4.024 (1) and 4.617 (1) Å, respectively]

Revealing A Head-on Major Merger in the Nearby NGC 6338 Group with Chandra and VLA observations

By analyzing the Chandra archival data of the nearby NGC 6338 galaxy group, we identify two X-ray bright clumps (N-clump and S-clump) within the central 100 kpc, and detect an arc-like X-ray brightness discontinuity at the south boundary of the N-clump, which is defined as a cold front with a gas flow Mach number of M<0.8. Furthermore, at the north-east boundary of the S-clump (dominated by galaxy NGC 6338) another X-ray edge is detected that corresponds to a weaker cold front. Therefore, the two clumps are approaching each other approximately from opposite directions, and the group is undergoing a head-on collision that is in a stage of pre-core passage. This merger scenario is also supported by the study of the line-of-sight velocity distribution of the group member galaxies. The merger mass ratio is about 1:1.8 as estimated from the central gas temperature of the two clumps, which suggests the merger is most likely to be a major merger. We also analyze the VLA 1.4 and 4.9 GHz radio data, but we do not detect any extended radio emission that is associated with the merger.Comment: Accepted by Ap

Dichlorido(4,5-diaza­fluoren-9-one-κ2 N,N′)palladium(II)

The structure of the title compound, [PdCl2(C11H6N2O)], shows a nearly square-planar geometry for the PdII atom within a Cl2N2 donor set

Study on coupling effect between the time-varying gear backlash and the different time-varying mesh parameters on the gear system

The vibration excitation of the rolling mill mainly comes from the gearbox in the process of rolling strip, and the meshing excitation is the main excitation factor of the gearbox. And the gear backlash plays an important role in the meshing excitation. However, the backlash is inevitable in the process of designing the gear system. Therefore, it is important to select the appropriate gear backlash to reduce the vibration amplitude of the gearbox, to improve the rolling speed and the quality of the steel strip. So, in this paper, the effect of the different variation amplitudes for the time-varying gear backlash (TVGB) on the vibration characteristics of the gear system under various mesh parameters is studied. A new formulation for calculating nonlinear damping and time varying meshing stiffness is applied in this coupling model. The results show that increasing of the load torque, the damping ratio, the system parameter or decreasing the directional rotation radius variation or kinematic transmission error caused the effects of variation amplitudes for the (TVGB) on the dynamic characteristics of the gear system to decrease. Test data from a gearbox experimental table verifies the accuracy of the model. The model is shown to be capable of simulating the mutually coupled effect between the backlash and the different parameters on the gear system. So, the new coupled model can be used as guide to select the appropriate gear backlash values for the rolling mill under different operating conditions

A Comprehensive 3-D Model on Gas Metal Arc Welding

A unified comprehensive model was developed to simulate the transport phenomena occurring during the gas metal arc welding process. An interactive coupling between arc plasma; melting of a continuously fed electrode; droplet formation, detachment, transfer, and impingement onto the workpiece under the influences of several competing forces including gravity, electromagnetic force, arc pressure, plasma shear stress, and surface tension; and weld pool dynamics all were considered. The transient distributions of current density, arc temperature, arc pressure, melt flow velocity and melt temperature in the droplet and in the weld pool were all calculated. Based on the unified model, the following investigations were conducted: 1) the effect of welding current on droplet generation, especially the use of pulsed current to achieve the one-droplet-per-pulse (ODPP) metal transfer; 2) the determination of dynamically stabled wire feed speeds for given welding conditions; 3) the effects of surface active elements (Marangoni effect) on the weld pool flow and solidified weld profile; 4) the fundamental mechanisms leading to the formation of ripples; 5) the issues associated with the beginning and the end of the welding (limited penetration and the formations of crater); 6) the deflection of arc plasma by an external magnetic field

Ethyl (E)-1-(2-styryl-1H-benzimidazol-1-yl)acetate

In the title compound, C19H18NO2, the dihedral angle between the benzimidazole and phenyl ring planes is 18.18 (17)°. The atoms of the ethyl side chain are disordered over two sets of sites in a 0.50:0.50 ratio. In the crystal, inter­molecular C—H⋯O hydrogen bonds and C—H⋯π contacts help to consolidate the packing