Amnart Boonloi^a, Withada Jedasadaratanachai^b,*

Frontiers in Heat and Mass Transfer, Vol.5, pp. 1-15, 2014, DOI:10.5098/hmt.5.19

Abstract 3D numerical investigations for heat transfer characteristics and flow configurations in a fin–and-oval-tube heat exchanger with V-tip pointing downstream delta winglet pairs (DDWP) are examined. The DDWPs are placed on the fin surface with pointing downstream and the oval tube row number is set at three in a staggered arrangement. The flow attack angles (θ = 15°, 30°, 45° and 60°) and the distance from V-tip to the oval tube center in transverse axis (a = 3.77, 4.77 and 5.77 mm) are investigated for Reynolds number based on hydraulic diameter, Re = 500 – 2500. The numerical results are compared… More >

Withada Jedsadaratanachai^a, Amnart Boonloi^b,*

Frontiers in Heat and Mass Transfer, Vol.6, pp. 1-19, 2015, DOI:10.5098/hmt.6.13

Abstract Numerical investigations on flow topology, heat transfer behavior and thermal performance evaluation in a circular tube heat exchanger with the punched delta winglet vortex generators (PDWVG) inserted in the middle of the test section are presented. The effects of the flow attack angles that converging to the center of the tube; α = 0°, 5°, 10°, 15°, 20°, 25°, and flow directions; winglet tips pointing downstream and upstream, are investigated for the Reynolds numbers; Re = 100 – 2000. The finite volume method and SIMPLE algorithm are used for the current study. The results are presented in terms of flow… More >

Minghua Cao^1,*, Konstantinos P. Baxevanakis¹, Vadim V. Silberschmidt¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.26, No.3, pp. 1-1, 2023, DOI:10.32604/icces.2023.09086

Abstract Compacted graphite iron (CGI) was attractive as an important material for the industry since its introduction in the last century. Thanks to its high strength, great wear resistance and thermal conductivity, CGI became extensively applied in the automotive industry as engine parts: brake drums, cylinder heads and exhaust manifolds. As a metal-matrix composite, CGI contains two microstructural phases: graphite inclusions and a metallic matrix. The main fracture mechanism of CGI under high-temperature service conditions at macroscale is linked to graphite-matrix (interfacial) debonding, formation of microcracks and their networks, and final failure of the material at microscale because of the mismatch… More >

Amit V. Patel¹, Arpan Desai¹, Issa Elfergani^2,3,*, Hiren Mewada⁴, Chemseddine Zebiri⁵, Keyur Mahant¹, Jonathan Rodriguez², Raed Abd-Alhameed³

CMES-Computer Modeling in Engineering & Sciences, Vol.137, No.3, pp. 2867-2879, 2023, DOI:10.32604/cmes.2023.026200

Abstract A four-element compact dual-band patch antenna having a common ground plane operating at 28/38 GHz is proposed for millimeter-wave communication systems in this paper. The multiple-input-multiple-output (MIMO) antenna geometry consists of a slotted ellipse enclosed within a hollow circle which is orthogonally rotated with a connected partial ground at the back. The overall size of the four elements MIMO antenna is 2.24λ × 2.24λ (at 27.12 GHz). The prototype of four-element MIMO resonator is designed and printed using Rogers RT Duroid 5880 with ε_r = 2.2 and loss tangent = 0.0009 and having a thickness of 0.8 mm. It covers… More >

Qi Liu¹, Zihao Wu^1,*, Xiaodong Liu²

Journal on Internet of Things, Vol.4, No.3, pp. 169-181, 2022, DOI:10.32604/jiot.2022.040368

Abstract This study proposed a lightweight but high-performance convolution network for accurately classifying five upper limb movements of arm, involving forearm flexion and rotation, arm extension, lumbar touch and no reaction state, aiming to monitoring patient’s rehabilitation process and assist the therapist in elevating patient compliance with treatment. To achieve this goal, a lightweight convolution neural network TMCA-Net (Time Multiscale Channel Attention Convolutional Neural Network) is designed, which combines attention mechanism, uses multi-branched convolution structure to automatically extract feature information at different scales from sensor data, and filters feature information based on attention mechanism. In particular, channel separation convolution is used… More >

Avaz Naghipour^1,*, Duc Manh Nguyen²

Journal of Quantum Computing, Vol.4, No.2, pp. 113-120, 2022, DOI:10.32604/jqc.2022.033712

Abstract In this paper, hyperbolic geometry is used to constructing new quantum color codes. We use hyperbolic tessellations and hyperbolic polygons to obtain them by pairing the edges on compact surfaces. These codes have minimum distance of at least and the encoding rate near to which are not mentioned in other literature. Finally, a comparison table with quantum codes recently proposed by the authors is provided. More >

B. Gangadhara Rao^a,*, K. Elangovan^b, K. Hema Chandra Reddy^a, M. Arulprakasajothi^c

Frontiers in Heat and Mass Transfer, Vol.16, pp. 1-8, 2021, DOI:10.5098/hmt.16.15

Abstract In this research, the 3-D coupled thermal electric model analyses on a sandwich bus bar are presented for the comparison of F Class & B Class of insulation. IEC defines the maximum temperature limit at the conductor based on the class of insulation. This paper gives the clarity on the variation on the current density i.e, the size of the conductor by varying the class of insulation. The study is conducted on tin plated 2000 A sandwich busbar system. The sandwich bus bar is made of copper conductors with tin plating and enclosed by an aluminum cover along its length.… More >

Muhammad Awais¹, Shahid Bashir¹, Awais Khan^1,2, Muhammad Asif², Nasim Ullah^3,*, Hend I. Alkhammash⁴

CMC-Computers, Materials & Continua, Vol.75, No.1, pp. 669-681, 2023, DOI:10.32604/cmc.2022.033939

Abstract This paper presents a compact Multiple Input Multiple Output (MIMO) antenna with WLAN band notch for Ultra-Wideband (UWB) applications. The antenna is designed on 0.8 mm thick low-cost FR-4 substrate having a compact size of 22 mm × 30 mm. The proposed antenna comprises of two monopole patches on the top layer of substrate while having a shared ground on its bottom layer. The mutual coupling between adjacent patches has been reduced by using a novel stub with shared ground structure. The stub consists of complementary rectangular slots that disturb the surface current direction and thus result in reducing mutual… More >

Awais Khan^1,2,*, Shahid Bashir¹, Salman Ghafoor³, Hatem Rmili^4,5, Jawad Mirza⁶, Ammar Ahmad¹

CMC-Computers, Materials & Continua, Vol.75, No.1, pp. 911-925, 2023, DOI:10.32604/cmc.2023.033866

Abstract Mutual coupling reduction or isolation enhancement in antenna arrays is an important area of research as it severely affects the performance of an antenna. In this paper, a new type of compact and highly isolated Multiple-Input-Multiple-Output (MIMO) antenna for ultra-wideband (UWB) applications is presented. The design consists of four radiators that are orthogonally positioned and confined to a compact 40 × 40 × 0.8 mm³ space. The final antenna design uses an inverted L shape partial ground to produce an acceptable reflection coefficient (S11 < −10 dB) in an entire UWB band (3.1–10.6) giga hertz (GHz). Moreover, the inter-element isolation… More >

Sahar Saleh^1,2, Mohd Haizal Jamaluddin^1,*, Bader Alali^3,4, Ayman A. Althuwayb⁴

CMC-Computers, Materials & Continua, Vol.74, No.3, pp. 5983-5999, 2023, DOI:10.32604/cmc.2023.035585

Abstract Compact fifth-generation (5G) low-frequency band filtering antennas (filtennas) with stable directive radiation patterns, improved bandwidth (BW), and gain are designed, fabricated, and tested in this research. The proposed filtennas are achieved by combining the predesigned compact 5G (5.975 – 7.125 GHz) third-order uniform and non-uniform transmission line hairpin bandpass filters (UTL and NTL HPBFs) with the compact ultrawide band Vivaldi tapered slot antenna (UWB VTSA) in one module. The objective of this integration is to enhance the performance of 5.975 – 7.125 GHz filtennas which will be suitable for modern mobile communication applications by exploiting the benefits of UWB VTSA. Based on… More >