Chang Huang, Shuzhan Bai, Guoxiang Li^*, Ke Sun^*

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.1, pp. 83-93, 2023, DOI:10.32604/fdmp.2022.021662

Abstract The influence of heterogeneous flow injection of urea at different velocities and temperatures on NOx conversion efficiency, ammonia storage and ammonia leakage is investigated experimentally. A diesel engine employing a selective catalytic reduction (SCR) technology is considered. It is found that for a fixed injection velocity, the degree of ammonia leakage changes depending on the temperature. The higher the temperature, the faster the catalytic reduction reaction and the smaller the degree of ammonia leakage. The temperature has a great influence on the catalytic reduction reaction rate. At an injection velocity of 10000/h, the average reaction rate at 420 C is… More >

Surajo Muhammad^1,*, Jun Jiat Tiang¹, Sew Kin Wong¹, Jamel Nebhen², Amjad Iqbal¹

CMC-Computers, Materials & Continua, Vol.69, No.1, pp. 487-501, 2021, DOI:10.32604/cmc.2021.018292

Abstract This paper proposed the design of a dual-port rectifier with multi-frequency operations. The RF rectifier is achieved using a combination of L-section inductive impedance matching network (IMN) at Port-1 with a multiple stubs impedance transformer at Port-2. The fabricated prototype can harvest RF signal from GSM/900, GSM/1800, UMTS/2100, Wi-Fi/2.45 and LTE/2600 frequency bands at (0.94, 1.80, 2.10, 2.46, and 2.63 GHz), respectively. The rectifier occupies a small portion of a PCB board at 0.20 λg × 0.15 λg. The proposed circuit realized a measured peak RF-to-dc (radio frequency direct current) power conversion efficiency (PCE) of (21%, 22.76%, 25.33%, 21.57%, and… More >

Surajo Muhammad^1,*, Jun Jiat Tiang¹, Sew Kin Wong¹, Amjad Iqbal¹, Amor Smida², Mohamed Karim Azizi³

CMC-Computers, Materials & Continua, Vol.68, No.1, pp. 167-184, 2021, DOI:10.32604/cmc.2021.016133

Abstract This paper presents a compact multi-band rectifier with an improved impedance matching bandwidth. It uses a combination of п–matching network (MN) at Port-1, with a parallel connection of three cell branch MN at Port-2. The proposed impedance matching network (IMN) is adopted to reduce circuit complexity, to improve circuit performance, and power conversion efficiency (PCE) of the rectifier at low input power. The fabricated rectifier prototype operates at 0.92, 1.82, 2.1, 2.46 and 2.65 GHz covering GSM/900, GSM/1800, UMTS2100, and Wi-Fi/2.45–LTE2600. The size of the compact rectifier on the PCB board is 0.13λ_g × 0.1λ_g. The fabricated rectifier achieved an… More >