Radhia Mansour, Abdessalem El Ghali

Revue Internationale de Géomatique, Vol.29, No.3, pp. 339-360, 2019, DOI:10.3166/rig.2019.00093

Abstract Flash floods are a type of natural disaster that poses a major threat to the population, urban constructions and road infrastructure and the environment. In Tunisia, this phenomenon is known since the sixties and has continued until today. The most important ones were recorded during the rainy years of 1969, 1983, 2003 and 2012. In order to identify areas at risk of flooding and reduce the vulnerability of the stakes, a Flash Flood Risk Mapping (FFRM) approach has been adopted for the development of a flood risk prevention plan (PPRI) in northeastern Tunisia. This method consists in: 1) integrating into… More >

Le Anh Duc^a , Nguyen Hay^a, Pham Van Kien^b,*

Frontiers in Heat and Mass Transfer, Vol.18, No.1, pp. 1-7, 2022, DOI:10.5098/hmt.18.44

Abstract This study determined the most appropriate thin layer drying model, the effective moisture diffusivity and the activation energy of moisture within Ganoderma lucidum in radio frequency (RF) assisted heat pump drying method. The thin layer drying experiments were conducted with input drying parameters such as: drying temperature of 40, 45 and 50°C and RF power of 0.65, 1.3 and 1.95 kW. In order to select a suitable form of drying curve, seven different thin layer drying models (Lewis, Page, Modified Page, Henderson and Pabis, Verma, Midilli, and Wang and Singh) were fitted to the experimental data. The Verma model was… More >

Le Anh Duc^a , Pham Van Kien^b,*, Nguyen Thanh Tan^b, Doan Thanh Son^b, Nhanh Van Nguyen^c, Ngoc Xuan Nguyen^d

Frontiers in Heat and Mass Transfer, Vol.20, No.1, pp. 1-6, 2023, DOI:10.5098/hmt.20.25

Abstract This study focused on the heat and mass transfer in radio (RF) assisted heat pump (HP) drying of carrots. The experimental drying of carrot by RF assisted HP drying method was conducted to evaluate the effect of RF power on drying efficiency including drying rate and heating rate. The input drying parameters were drying air temperature of 45oC, drying air velocity of 2.5 m/s and RF power of 0, 0.5 and 1.5 kW, in which, RF power of 0 was corresponding to HP drying method. The experimental drying results showed that in RF assisted HP drying method, the drying rate… More >

Yuhang He, Rongzhuo Zhang, Yifan Zhang, Zheng Wang^*

Journal of Renewable Materials, Vol.11, No.6, pp. 2729-2743, 2023, DOI:10.32604/jrm.2023.025867

Abstract In order to better meet the objective requirements of the use safety of the high-rise glulam building floor structure and the living comfort of the residents, the transient excitation, environmental excitation and frequency spectrum identification methods were used to carry out experimental modal test in-site on the three rooms numbered A, B and C of the same glulam structural building. The three rooms have different functions, different floor sizes and different floor supporting structures. The research results have shown that the first-order bending frequency of the floor structure of Room A is 27.50 Hz, the transverse second-order bending frequency is… More > Graphic Abstract

Fawad Nasim^1,2,*, Sohail Masood^1,2, Arfan Jaffar^1,2, Usman Ahmad¹, Muhammad Rashid³

Computer Systems Science and Engineering, Vol.46, No.3, pp. 3175-3190, 2023, DOI:10.32604/csse.2023.034550

Abstract An intelligent sound-based early fault detection system has been proposed for vehicles using machine learning. The system is designed to detect faults in vehicles at an early stage by analyzing the sound emitted by the car. Early detection and correction of defects can improve the efficiency and life of the engine and other mechanical parts. The system uses a microphone to capture the sound emitted by the vehicle and a machine-learning algorithm to analyze the sound and detect faults. A possible fault is determined in the vehicle based on this processed sound. Binary classification is done at the first stage… More >

Yunfan Huang¹, Qingquan Lv², Zhenzhen Zhang², Haiying Dong^1,*

Energy Engineering, Vol.120, No.6, pp. 1401-1420, 2023, DOI:10.32604/ee.2023.027365

Abstract The virtual synchronous generator (VSG) can simulate synchronous machine’s operation mechanism in the control link of an energy storage converter, so that an electrochemical energy storage power station has the ability to actively support the power grid, from passive regulation to active support. Since energy storage is an important physical basis for realizing the inertia and damping characteristics in VSG control, energy storage constraints of the physical characteristics on the system control parameters are analyzed to provide a basis for the system parameter tuning. In a classic VSG control, its virtual inertia and damping coefficient remain unchanged. When the grid… More >

Wei Chen¹, Na Sun¹, Zhicheng Ma², Wenfei Liu², Haiying Dong^1,*

Energy Engineering, Vol.120, No.6, pp. 1445-1464, 2023, DOI:10.32604/ee.2023.027158

Abstract To address the frequency fluctuation problem caused by the power dynamic imbalance between the power system and the load when a large number of new energy sources are connected to the grid, a two-layer fuzzy control strategy is proposed for the participation of the energy storage battery system in FM. Firstly, considering the coordination of FM units responding to automatic power generation control commands, a comprehensive allocation strategy of two signals under automatic power generation control commands is proposed to give full play to the advantages of two FM signals while enabling better coordination of two FM units responding to… More > Graphic Abstract

Qi Feng¹, Zhengyue Ren², Dan Wang^3,*

Structural Durability & Health Monitoring, Vol.17, No.1, pp. 71-88, 2023, DOI:10.32604/sdhm.2023.024912

Abstract The dynamic elasticity modulus (E_d) is the most commonly used indexes for nondestructive testing to represent the internal damage of hydraulic concrete. Samples with a specific size is required when the transverse resonance method was used to detect the E_d, resulting in a limitation for field tests. The impact-echo method can make up defects of traditional detection methods for frost-resistance testing, such as the evaluation via the loss of mass or strength. The feasibility of the impact-echo method to obtain the relative E_d is explored to detect the frost-resistance property of large-volume hydraulic concretes on site. Results show that the… More >

Hui Fang¹, Jingsen Zhou¹, Haozheng Wang^2,*, Yanxu Wang², Hongji Xiang¹, Yechun Xin²

Energy Engineering, Vol.120, No.4, pp. 831-850, 2023, DOI:10.32604/ee.2023.025171

Abstract Recently, high-frequency oscillation of the modular multilevel converter (MMC) based high-voltage direct current (HVDC) projects has attracted great attentions. In order to analyze the small-signal stability, this paper uses the harmonic state-space (HSS) method to establish a detailed frequency domain impedance model of the AC-side of the HVDC transmission system, which considers the internal dynamic characteristics. In addition, the suggested model is also used to assess the system's high-frequency oscillation mechanism, and the effects of the MMC current inner loop control, feedforward voltage links, and control delay on the high-frequency impedance characteristics and the effect of higher harmonic components. Finally,… More >

K. Jayanthi^1,*, A. M. Kalpana²

Computer Systems Science and Engineering, Vol.46, No.2, pp. 1689-1705, 2023, DOI:10.32604/csse.2023.034613

Abstract The fifth-generation (5G) wireless technology is the most recent standardization in communication services of interest across the globe. The concept of Multiple-Input-Multiple-Output antenna (MIMO) systems has recently been incorporated to operate at higher frequencies without limitations. This paper addresses, design of a high-gain MIMO antenna that offers a bandwidth of 400 MHz and 2.58 GHz by resonating at 28 and 38 GHz, respectively for 5G millimeter (mm)-wave applications. The proposed design is developed on a RT Duroid 5880 substrate with a single elemental dimension of 9.53 × 7.85 × 0.8 mm³. The patch antenna is fully grounded and is fed with a 50-ohm stepped impedance… More >