Daniel Yabrudy Mercado^a,*, Juan Fajardo Cuadro^a, Bienvenido Sarria López^b, Camilo Cardona Agudelo^b

Frontiers in Heat and Mass Transfer, Vol.15, pp. 1-12, 2020, DOI:10.5098/hmt.15.25

Abstract This paper presents the efficiency-centered maintenance method to plan the maintenance intervention of the heat exchangers of a preheat train, taking into account the economic-energy improvement and maintenance cost. An appropriate cleaning schedule is needed to preserve the key performance parameters (KPPs) throughout the operation, if possible, nearest to the design values. The results of this work show that it is possible to schedule maintenance activities based on KPPs such as effectiveness and determine the time of execution and the type of maintenance that is most cost-efficient, without affecting and complementing the criteria for maintenance schedules based on reliability/risk. More >

Rongge Xiao^a,*, Yanwei Zhang^a , Xu Gao^b , Hongping Yu^c , Wangying Wei^a

Frontiers in Heat and Mass Transfer, Vol.15, pp. 1-8, 2020, DOI:10.5098/hmt.15.22

Abstract In order to improve DMR (double mixed refrigerant) liquefaction process and reduce operation cost of natural gas liquefaction plant, a four-stage DMR process optimization simulation calculation model was established through Aspen Hysys v8.4 and the purpose of the optimization model is achieved by using the segmented compression process in this paper. The minimum energy consumption and the highest exergy efficiency were used as the objective functions. By using the optimizer in HYSYS, the process parameters and ingredient proportion of the mixed refrigerant in the fourstage DMR process was optimized, and the best process parameters and ingredient proportion of the mixed… More >

Firas Aziz Ali^a,*, Adnan M. Alsaffawi^b , Karam Hashim Mohammed^a

Frontiers in Heat and Mass Transfer, Vol.15, pp. 1-7, 2020, DOI:10.5098/hmt.15.21

Abstract The augmentation of the heat transfer in heat exchangers is one of the methods to increase efficiency of the system. The double tube heat exchanger is selected to many suitable techniques of heat transfer enhancement. In this study; the friction factor and heat transfer coefficient of double tube is evaluated experimentally. The Al₂O₃ nanoparticles dispersed in ethylene glycol (EG) with a diameter 50 nm and the weight concentration (0.1%, 0.3%, 0.5%, 0.7%, 1%) has been utilized. Then the effect of parallel current and counter current with different ranges of Reynolds number (10,000 to 30,000) on the friction factor and heat… More >

Wakana Hiratsuka^a , Takashi Fukue^b,*, Hidemi Shirakawa^c, Katsuyuki Nakayama^d, Yasushi Koito^e

Frontiers in Heat and Mass Transfer, Vol.15, pp. 1-8, 2020, DOI:10.5098/hmt.15.16

Abstract This paper describes a possibility of heat transfer enhancement in a mm-scale flow channel by using a combination of some projections and pulsating flow. The objective of this research is to develop a novel heat exchanger for miniaturized productions such as high-density packaging electronic equipment by applying pulsating flow to enhance heat transfer while inhibiting an increase of pressure drop. In order to evaluate the possibility of applying pulsating flow to miniature water channels, a three-dimensional flow and heat transfer analysis was performed. Heat transfer performance of a combination of pulsating water flow and a projection was investigated. The mechanism… More >

Abdelmajid Krouma^1,2,*

Phyton-International Journal of Experimental Botany, Vol.92, No.7, pp. 2133-2150, 2023, DOI:10.32604/phyton.2023.029048

Abstract Iron is an essential element for plants as well as all living organisms, functioning in various physiological and biochemical processes such as photosynthesis, respiration, DNA synthesis, and N₂ fixation. In the soil, Fe bioavailability is extremely low, especially under aerobic conditions and at high pH ranges. In contrast, plants with nodules on their roots that fix atmospheric nitrogen need much more iron. To highlight the physiological traits underlying the tolerance of N₂-fixing common bean to iron deficiency, two genotypes were hydroponically cultivated in a greenhouse: Coco nain (CN) and Coco blanc (CB). Plants were inoculated with an efficient strain of… More >

Huwida A. A. Abdel-Kader¹, Naeima Yousef¹, Mohammad Anwar Hossain^2,*, Mona F. A. Dawood^1,*

Phyton-International Journal of Experimental Botany, Vol.92, No.7, pp. 1955-1974, 2023, DOI:10.32604/phyton.2023.028583

Abstract The extensive use of nanoparticles (NPs) in diverse applications causes their localization to aquatic habitats, affecting the metabolic products of primary producers in aquatic ecosystems, such as algae. Synthesized calcium oxide nanoparticles (CaO NPs) are of the scarcely studied NPs. Thus, the current work proposed that the exposure to CaO NPs may instigate metabolic pathway to be higher than that of normally growing algae, and positively stimulate algal biomass. In this respect, this research was undertaken to study the exposure effect of CaO NPs (0, 20, 40, 60, 80, and 100 µg mL⁻¹ ) on the growth, photosynthesis, respiration, oxidative… More >

Yuqin Wang^1,2,3,*, Luxiang Zhou³, Mengle Han¹, Lixiang Shen¹

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.9, pp. 2215-2228, 2023, DOI:10.32604/fdmp.2023.027188

Abstract The main structural parameters of the IR100-80-100A type chemical centrifugal pump have been optimized by means of an orthogonal test approach. The centrifugal pump has been modeled using the CFturbo software, and 16 sets of orthogonal-test schemes have been defined on the basis of 4 parameters, namely, the blade number, blade outlet angle, impeller outlet diameter, and impeller outlet width. Such analysis has been used to determine the influence of each index parameter on the pump working efficiency and identify a set of optimal combinations of such parameters. The internal flow field in the centrifugal pump has been simulated by… More > Graphic Abstract

Hawraa S. Mohammed^*, Mahmoud A. Mashkour

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.9, pp. 2329-2343, 2023, DOI:10.32604/fdmp.2023.026890

Abstract This study considers the effect of Eichhornia Crassipes Biodiesel (ECB) blends on the performances, combustion, and emission characteristics of a direct injection compression ignition engine operated in a dual-fuel mode (DFM) and equipped with an Exhaust gas recirculation technique (EGR). In particular, a single-cylinder, four-stroke, water-cooled diesel engine was utilized and four modes of fuel operation were considered: mode I, the engine operated with an ordinary diesel fuel; mode II, the engine operated with the addition of 2.4 L/min of liquefied petroleum gas (LPG) and 20% EGR; mode III, 20% ECB with 2.4 L/min LPG and 20% EGR; mode IV,… More >

Caifeng Wen^1,2, Qiang Wang^1,*, Yang Cao¹, Liru Zhang^1,2, Wenxin Wang³, Boxin Zhang¹, Qian Du¹

Energy Engineering, Vol.120, No.7, pp. 1603-1619, 2023, DOI:10.32604/ee.2023.027074

Abstract To solve the problems of large losses and low productivity of permanent magnet synchronous generators used in wind power systems, the field-circuit coupling method is used to accurately solve the electromagnetic field and temperature field of the generator. The loss distribution of the motor is accurately obtained by considering the influence of external circuit characteristics on its internal physical field. By mapping the losses to the corresponding part of the three-dimensional finite element model of the motor, the temperature field is solved, and the global temperature distribution of the generator, considering the influence of end windings, is obtained. By changing… More >

Hanan Abdullah Mengash¹, Hamed Alqahtani², Mohammed Maray³, Mohamed K. Nour⁴, Radwa Marzouk¹, Mohammed Abdullah Al-Hagery⁵, Heba Mohsen⁶, Mesfer Al Duhayyim^7,*

CMC-Computers, Materials & Continua, Vol.75, No.3, pp. 4805-4820, 2023, DOI:10.32604/cmc.2023.037810

Abstract With the flexible deployment and high mobility of Unmanned Aerial Vehicles (UAVs) in an open environment, they have generated considerable attention in military and civil applications intending to enable ubiquitous connectivity and foster agile communications. The difficulty stems from features other than mobile ad-hoc network (MANET), namely aerial mobility in three-dimensional space and often changing topology. In the UAV network, a single node serves as a forwarding, transmitting, and receiving node at the same time. Typically, the communication path is multi-hop, and routing significantly affects the network’s performance. A lot of effort should be invested in performance analysis for selecting… More >