Two shell-and-tube heat exchangers (STHXs) using continuous helical baffles instead of segmental used in conventional STHXs were proposed, designed, and tested this study. The two proposed have the same tube bundle but different shell configurations. flow pattern side exchanger with was forced to be rotational due geometry baffles, which results a significant increase transfer coefficient per unit pressure drop exchanger. Properly designed can reduce fouling prevent flow-induced vibration as...

A novel composite cementitious material was constructed by synergistically utilizing multiple industrial solid wastes, including electrolytic manganese residue (EMR), red mud (RM), and ground granulated blast furnace slag (GGBS), with calcium hydroxide [Ca(OH)2] as an alkaline activator. In addition, the mechanical properties of materials were systematically analyzed under different raw ratios, alkali activator dosages, water-binder ratios. To further investigate hydration products...

ABSTRACT In this letter, a compact ultrawideband polarization diversity MIMO antenna system with dual band‐notched characteristics is proposed. The proposed element consists of metal ground stepped slot etched on it. fed by 50‐Ω microstrip line the top layer. Dual notched bands (5G WLAN and 8G X band) are achieved etching an open ended split ring resonator in plane, respectively. Two identical elements arranged orthogonally perpendicularly to obtain enhance port isolation. A simple Y‐shaped...

ABSTRACT A compact coplanar waveguide (CPW) fed ultrawideband (UWB) slot antenna for multiple‐input‐multiple‐output (MIMO)/diversity applications is presented in this letter. The consists of two waveguides (CPWs) feeding circular radiating elements and a protruded stub, which placed at between them. are arrange orthogonally perpendicularly to obtain polarization diversity. Notched band X‐band communication downlinks achieved by etching split ring resonator slots the radiators other notched...

The sound absorption coefficient was evaluated for the acoustic performance of pavement in many studies, which is an evaluation index generated by non-contact interaction between tyre and pavement. impedance tube not enough to simulate noise tyre/pavement interaction. This paper presents findings a lab field characteristics porous asphalt on use tyre-rolling-down (TRD) methods as well OBSI method. effect different factors (pavement type, thickness, void ratio, maximum nominal particle size)...

Nanostructures with different dimensions, including bulk crystals, thin films, nanowires, nanobelts and nanorods, have received considerable attention due to their novel functionalities outstanding applications in various areas.

This study presents a cavity‐backed aperture‐coupled switch beam antenna array for 60‐GHz applications. A 1 × 4‐element patch is adopted as the radiating part, which fed by Butler matrix feed network that consists of couplers, crossovers, and phase shifters. By using cavity can help suppress surface wave propagation along substrate, not only achieves high‐aperture efficiency gain but also maintains wide steering angle in H ‐plane. The designed substrate integrated waveguide (SIW) technology...

A graphene-based plasmonic metasurface which can independently control different polarized electromagnetic waves with reasonably small losses in terahertz regime is proposed and demonstrated this paper. This composed of graphene based elements. Owing to anisotropic resonance the elements, reflected phases magnitudes orthogonally be controlled by varying dimensions element. Four types metasurfaces distributions are synthesized simulated, exhibiting diverse functions such as beam splitting,...

In this letter, a quad-mode bandpass filter is built up based on novel defected ground structure (DGS) resonator which has two symmetric planes. The odd-/even-mode theory applied to analyze the operating principle of four resonances with their equivalent circuit models. can be effectively tuned by adjusting corresponding dimensions. fabricated center frequency 2.45 GHz and wide stopband 7.8 rejection below -30 dB, extends at least 30 -16 dB. Particularly, exhibits an excellent attenuation...

Based on data from core analysis and thin section, the influence of overpressure compaction cementation Paleogene Dongying Formation reservoir is studied quantitatively in northwestern subsag Bozhong sag, Bohai Bay Basin. Reservoir inhibited obviously by because strength sandstones setting weaker than that its overlying normal setting. The primary porosity preserved about 1.1% as pore pressure above hydrostatic every 4 MPa Moreover, affected overpressure: strong adjacent inner-pressure...

A new approach to specify the inlet boundary conditions that considering air jet effect was proposed in this study simulate gas–solid two-phase flows circulating fluidized bed (CFB) risers more accurately. computational fluid dynamics (CFD) model based on Eulerian–Eulerian coupled with kinetic theory of granular flow adopted using conditions. Simulation results were compared experimental data. Good agreement between numerical and data observed under different operating conditions, which...

This letter presents the design and analysis of a compact dual-polarized slot antenna using triple-mode stepped slot-line resonator dual-mode cross-shaped monopole. The orthogonal polarization is achieved by feeding two ports symmetrically at opposite positions slot. All five resonance frequencies can be flexibly adjusted tuning different dimension parameters, so increasing frequency difference between modes, very wide common operating band (1.63-2.93 GHz) obtained also with high port...

The future terahertz (THz) communications utilize the frequency range above 300 GHz and can realize a very high data rate. However, one major challenge is angle of arrival (AoA) estimation because extremely path loss requires adaptive gain directive antennas (e.g. via beamforming). Although, this topic has been comprehensively studied, there so far no adequate method subject to simple hardware design computational effort as well THz channel characteristics. This paper presents an AoA...

ABSTRACT This study investigates discharge phenomena in suspended droplets using needle–needle electrodes. By employing ultrasonic suspension technology for noncontact droplet and high‐speed cameras capturing time‐resolved images, the examines impact of on characteristics morphology. Results show that alter electric field distribution, affecting paths. Low‐conductivity hinder discharge, causing deflection or changes channel, whereas high‐conductivity act as electrodes, facilitating channel...

ABSTRACT In this paper, a coupled‐fed tri‐band multiple‐input‐multiple‐output (MIMO) mobile antenna is proposed for WWAN and LTE applications. The MIMO system composed of two elements they are oriented diagonally at the non‐grounded portion FR‐4 substrate. Each element consists planar inverted‐F (PIFA) by L‐shaped driven strip monopole. By adding parallel‐resonant spiral slit in main ground, bandwidth lower band can be enhanced to cover whole GSM850 GSM900 bands without increasing size....

Abstract A wideband bandpass filter based on dual‐mode defected ground structure resonator (DGSR) is designed and effectively analysed by utilising the even‐/odd‐mode theory equivalent circuit models. The lower upper cutoff frequencies of can be independently tuned adjusing even‐ odd‐mode resonant DGSR, respectively. fabricated prototype centred at 2.27 GHz with a wide bandwidth (FBW 63.4%), low insertion loss (0.386 dB), high selectivity stopband. attenuation slopes in passband transitions...