M. Yakut Ali^a,*, Fanghao Yang^a, Ruixian Fang^a, Chen Li^a, Jamil Khan^a,†

Frontiers in Heat and Mass Transfer, Vol.2, No.3, pp. 1-11, 2011, DOI:10.5098/hmt.v2.3.3003

Abstract This study experimentally investigates single phase heat transfer and pressure drop characteristics of a shallow rectangular microchannel heat sink whose surface is enhanced with copper nanowires (CuNWs). The hydraulic diameter of the channel is 672 μm and the bottom wall is coated with Cu nanowires (CuNWs) of 200 nm in diameter and 50 μm in length. CuNWs are grown on the Cu heat sink by electrochemical synthesis technique which is inexpensive and readily scalable. The heat transfer and pressure drop results of CuNWs enhanced heat sink are compared with that of bare copper surface heat sink using deionized (DI) water… More >

Driss Achemlal^a,† , Mohammed Sriti^b , Mohamed El Haroui^b , Elyazid Flilihi^b , Mounir Kriraa^a

Frontiers in Heat and Mass Transfer, Vol.9, pp. 1-10, 2017, DOI:10.5098/hmt.9.34

Abstract In this paper we study the combined free convection, due to thermal and species diffusion, of a viscous incompressible non Newtonian fluid over a vertical plate embedded in a saturated porous medium with three thermal states of the surface and a constant concentration in the presence of a chemical reaction. The effect of temperature dependent viscosity is also investigated. The Ostwald-de Waele power-law model is used to characterize the non-Newtonian fluid behavior. The governing boundary layer equations along with the boundary conditions are first cast into a dimensionless form by a unique similarity transformation and the resulting coupled differential equations… More >

Nur Fairuz Mohamed Yusof¹, Dahaman Ishak², Muhammad Ammirrul Atiqi Mohd Zainuri^3,*, Muhammad Najwan Hamidi², Zuhair Muhammed Alaas⁴, Mohamed Mostafa Ramadan Ahmed⁵

Intelligent Automation & Soft Computing, Vol.37, No.2, pp. 2441-2457, 2023, DOI:10.32604/iasc.2023.037778

Abstract Grid-connected reactive-load compensation and harmonic control are becoming a central topic as photovoltaic (PV) grid-connected systems diversified. This research aims to produce a high-performance inverter with a fast dynamic response for accurate reference tracking and a low total harmonic distortion (THD) even under nonlinear load applications by improving its control scheme. The proposed system is expected to operate in both stand-alone mode and grid-connected mode. In stand-alone mode, the proposed controller supplies power to critical loads, alternatively during grid-connected mode provide excess energy to the utility. A modified variable step incremental conductance (VS-InCond) algorithm is designed to extract maximum power… More >

Rasool M. Imran^1,2,*, Mohammed R. Saeed¹, Mohammed Amer Mohammed³, Osama A. Suhry³, Ihsan H. Abdulqadder⁴, Hasan Wahhab Salih⁵, Mohammed R. Almallah⁶, Firas M. F. Flaih³

Energy Engineering, Vol.119, No.6, pp. 2447-2467, 2022, DOI:10.32604/ee.2022.021871

Abstract

Usually, rural areas can be electrified via three-phase distribution transformers with relatively large capacities. In such areas, low voltage lines are used for long distances, which cause power losses and voltage drop for different types of consumers. Reducing losses and improving voltage profiles in rural distribution networks are significant challenges for electricity distribution companies. However different solutions were proposed in the literature to overcome these challenges, most of them face difficulties when applied in the conventional distribution network. To address the above issues, an applicable solution is proposed in this paper by installing a number of small-capacity distribution transformers instead… More >

T. J. Thomas Thangam^*, K. Muthu Vel

Intelligent Automation & Soft Computing, Vol.35, No.3, pp. 3459-3478, 2023, DOI:10.32604/iasc.2023.025521

Abstract The generation of electricity based on renewable energy sources, particularly Photovoltaic (PV) system has been greatly increased and it is simply instigated for both domestic and commercial uses. The power generated from the PV system is erratic and hence there is a need for an efficient converter to perform the extraction of maximum power. An improved interleaved Single-ended Primary Inductor-Converter (SEPIC) converter is employed in proposed work to extricate most of power from renewable source. This proposed converter minimizes ripples, reduces electromagnetic interference due to filter elements and the continuous input current improves the power output of PV panel. A… More >

Lei Ren, Lei Zhang^*

Energy Engineering, Vol.119, No.3, pp. 1179-1196, 2022, DOI:10.32604/ee.2022.018902

Abstract Due to the components at twice the fundamental frequency of output voltage in the instantaneous output power of a two-stage single-phase inverter (TSI), the second harmonic current (SHC) is generated in the front-end dc-dc converter (FDC). To reduce the SHC, optimizing the control strategy of the FDC is an effective and costless approach. From the view of visual impedance, this paper conducts an intensive study on the SHC reduction strategies. Origin of the SHC is illustrated first. Then, the equivalent circuit models of the FDC under different control strategies are proposed to analyse the SHC propagation characteristic. The derived model… More >

Hongchun Shu^1,2, Yaqi Deng^1,2,*, Pulin Cao², Jun Dong², Hongjiang Rao², Zhiqian Bo²

Energy Engineering, Vol.119, No.2, pp. 523-538, 2022, DOI:10.32604/ee.2022.015570

Abstract The arc-suppression coil (ASC) in parallel low resistance (LR) multi-mode grounding is adopted in the mountain wind farm to cope with the phenomenon that is misoperation or refusal of zero-sequence protection in LR grounding wind farm. If the fault disappears before LR is put into the system, it is judged as an instantaneous fault; while the fault does not disappear after LR is put into the system, it is judged as a permanent fault; the single-phase grounding fault (SLG) protection criterion based on zero-sequence power variation is proposed to identify the instantaneous-permanent fault. Firstly, the distribution characteristic of zero-sequence voltage… More >

Nugroho Agung Pambudi^*, Awibi Muhamad Yusuf, Alfan Sarifudin

Energy Engineering, Vol.119, No.1, pp. 275-286, 2022, DOI:10.32604/EE.2022.017356

Abstract Data centers are recognized as one of the most important aspects of the fourth industrial revolution since conventional data centers are inefficient and have dependency on high energy consumption, in which the cooling is responsible for 40% of the usage. Therefore, this research proposes the immersion cooling method to solving the high energy consumption of data centers by cooling its component using two types of dielectric fluids. Four stages of experimental methods are used, such as fluid types, cooling effectiveness, optimization, and durability. Furthermore, benchmark software is used to measure the CPU maximum work with the temperature data performed for… More >

Zun Bi^1,2,3, Ke Jia^1,2,3, Yunfei Liu^1,2,3,*, Yinong Lyu^1,2,3,*

Journal of Renewable Materials, Vol.10, No.2, pp. 431-451, 2022, DOI:10.32604/jrm.2022.016735

Abstract A series of uniform single-phase spherical BaWO₄: Dy³⁺, Tm³⁺, Eu³⁺ phosphors were prepared via a microwave hydrothermal method by using trisodium citrate dehydrate as surfactant. The phase structure, morphology and photoluminescence properties were measured by powder X-ray diffraction, scanning electron microscope and fluorescence spectrometer, respectively. The results show that uniform spherical microcrystals with diameters in the range of 2–4 μm are obtained. And the phase and morphology of samples are not significantly changed by doping rare earth (RE³⁺) ions. Under the excitation wavelength of 356 and 365 nm, the samples BaWO₄: 0.03Dy³⁺, yTm³⁺ can emit cold white light. In order to… More >

Mohamed I. Mossad^1,*, Fahd A. banakhr¹, Sherif S. M. Ghoneim², Tarek A. AbdulFattah³, Mohamed Mahmoud Samy⁴

Intelligent Automation & Soft Computing, Vol.28, No.3, pp. 715-727, 2021, DOI:10.32604/iasc.2021.017534

Abstract This paper introduces voltage self-regulation of a variable speed single-phase induction generator-based wind energy conversion system (WECS) for stand-alone applications. The idea behind the voltage self-regulation technique proposed in this paper is adjusting the fixed capacitor’s effective value for exciting the single-phase induction generator. This adjustment is performed using an inexpensive Sinusoidal PWM (SPWM) switching circuit to short circuit the capacitor during different periods to make a virtual change of the capacitance value extracted from the fixed capacitor. That optimized fixed capacitor size is firstly determined using harmony search (HS) optimization technique. HS is also used to determine the capacitance… More >