Md Nahin Mahmood^*, Boyun Guo

Energy Engineering, Vol.120, No.12, pp. 2707-2720, 2023, DOI:10.32604/ee.2023.042996

Abstract The energy industry faces a significant challenge in extracting natural gas from offshore natural gas hydrate (NGH) reservoirs, primarily due to the low productivity of wells and the high operational costs involved. The present study offers an assessment of the feasibility of utilizing geothermal energy to augment the production of natural gas from offshore gas hydrate reservoirs through the implementation of the methane-CO₂ swapping technique. The present study expands the research scope of the authors beyond their previous publication, which exclusively examined the generation of methane from marine gas hydrates. Specifically, the current investigation explores the feasibility of utilizing the… More >

Baofeng Ji^1,2,3,*, Ying Wang^1,2,3, Weixing Wang¹, Shahid Mumtaz⁴, Charalampos Tsimenidis⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.138, No.2, pp. 1885-1905, 2024, DOI:10.32604/cmes.2023.030872

Abstract The utilization of mobile edge computing (MEC) for unmanned aerial vehicle (UAV) communication presents a viable solution for achieving high reliability and low latency communication. This study explores the potential of employing intelligent reflective surfaces (IRS) and UAVs as relay nodes to efficiently offload user computing tasks to the MEC server system model. Specifically, the user node accesses the primary user spectrum, while adhering to the constraint of satisfying the primary user peak interference power. Furthermore, the UAV acquires energy without interrupting the primary user’s regular communication by employing two energy harvesting schemes, namely time switching (TS) and power splitting… More >

Ying Zhang¹, Weiming Niu², Supu Xiu^1,3, Guangchen Mu^3,*

CMES-Computer Modeling in Engineering & Sciences, Vol.138, No.2, pp. 1865-1884, 2024, DOI:10.32604/cmes.2023.030114

Abstract In this paper, we investigate the energy efficiency maximization for mobile edge computing (MEC) in intelligent reflecting surface (IRS) assisted unmanned aerial vehicle (UAV) communications. In particular, UAV can collect the computing tasks of the terrestrial users and transmit the results back to them after computing. We jointly optimize the users’ transmitted beamforming and uploading ratios, the phase shift matrix of IRS, and the UAV trajectory to improve the energy efficiency. The formulated optimization problem is highly non-convex and difficult to be solved directly. Therefore, we decompose the original problem into three sub-problems. We first propose the successive convex approximation… More >

Ying Zhang^1,*, Weiming Niu², Leibing Yan¹

CMES-Computer Modeling in Engineering & Sciences, Vol.138, No.1, pp. 885-902, 2024, DOI:10.32604/cmes.2023.029234

Abstract In this paper, we consider mobile edge computing (MEC) networks against proactive eavesdropping. To maximize the transmission rate, IRS assisted UAV communications are applied. We take the joint design of the trajectory of UAV, the transmitting beamforming of users, and the phase shift matrix of IRS. The original problem is strong non-convex and difficult to solve. We first propose two basic modes of the proactive eavesdropper, and obtain the closed-form solution for the boundary conditions of the two modes. Then we transform the original problem into an equivalent one and propose an alternating optimization (AO) based method to obtain a… More >

Yonghui Lin¹, Zhengyu Zhu^2,*

CMES-Computer Modeling in Engineering & Sciences, Vol.138, No.1, pp. 663-677, 2024, DOI:10.32604/cmes.2023.028584

Abstract In this paper, we investigate IRS-aided user cooperation (UC) scheme in millimeter wave (mmWave) wireless-powered sensor networks (WPSN), where two single-antenna users are wireless powered in the wireless energy transfer (WET) phase first and then cooperatively transmit information to a hybrid access point (AP) in the wireless information transmission (WIT) phase, following which the IRS is deployed to enhance the system performance of the WET and WIT. We maximized the weighted sum-rate problem by jointly optimizing the transmit time slots, power allocations, and the phase shifts of the IRS. Due to the non-convexity of the original problem, a semidefinite programming… More >

Erick Malédon¹, Elie Nudol¹, Christophe Perrot¹, Marie-Claire Gravillon¹, Ronan Rivallan^2,3, Denis Cornet², Hâna Chair^2,3, Komivi Dossa^1,2,3,*

Phyton-International Journal of Experimental Botany, Vol.92, No.10, pp. 2861-2874, 2023, DOI:10.32604/phyton.2023.042397

Abstract Various biological constraints including erratic and asynchronous flowering between male and female plants hinder successful hybrid development and genetic gains in greater yam breeding programs. Therefore, pollen storage has gained much attention to facilitate artificial pollinations and increase the genetic gains. This 4-year study aimed at developing a practical long-term pollen storage technique for the successful development of yam hybrids. Fresh pollens were collected from two Dioscorea alata males, then lyophilized (two lyophilization treatments were applied), followed by storage at room temperature (24°C–25°C) for 12 months. Moreover, the lyophilized and stored pollens were tested for viability by crossing with four… More >

Shuyu Sun^1,*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.27, No.2, pp. 1-2, 2023, DOI:10.32604/icces.2023.09671

Abstract Two or multiple phases commonly occur as fluid mixture in petroleum industry, where oil, gas and water are often produced and transported together. As a result, petroleum reservoir engineers spent great efforts in the development and production of oil and gas reservoirs by conducting and interpolating the simulation of multiphase flows in porous geological formation. Meanwhile, environmental scientists use subsurface flow and transport models to investigate and compare for example various schemes to inject and store CO2 in subsurface geological formations, such as depleted reservoirs and deep saline aquifers. In this work, we first present an introduction of numerical simulation… More >

Mianmo Meng^1,*, Wenming Ji²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.26, No.4, pp. 1-1, 2023, DOI:10.32604/icces.2023.09159

Abstract Tight reservoirs hold a vast natural gas in Ordos Basin, and efficient development of these resources can offset the energy shortage. Due to the low-porosity and low-permeability, hydraulic fracturing becomes necessary to tap its resources. After fracturing, a large amount of fracturing fluid fills pore space near hydraulic fracture, which will influence the gas production. This study focused on the water occurrence of tight gas reservoirs and its influencing factors. Samples were selected from Upper Paleozoic Taiyuan and Shihezi Formations from Ordos Basin. The main experiments include porosity, permeability, mineral composition, nitrogen adsorption (NA), mercury intrusion porosimetry (MIP), nuclear magnetic… More >

Meng Wang¹, Jun Yao¹, Dongyan Fan^1,*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.26, No.2, pp. 1-1, 2023, DOI:10.32604/icces.2023.08913

Abstract In view of the current situation of the lack of suitable calculation models for the analysis of production dynamics of fractured horizontal well with CO₂ huff and puff in shale reservoirs，based on the process and mechanism of CO₂ huff and puff, an analytical model for the production dynamics of fractured horizontal well with CO₂ huff and puff in shale reservoirs was proposed, in which took into account the changes in crude oil viscosity and volume caused by the difference in CO₂ concentration at different locations in the formation after soaking and the adsorption and desorption process of CO₂ in the… More >

Haoyu Fu^1,2,3, Hua Liu^1,2, Xiaohu Hu^1,2, Lei Wang^1,2,3,*

CMES-Computer Modeling in Engineering & Sciences, Vol.137, No.3, pp. 2285-2309, 2023, DOI:10.32604/cmes.2023.027996

Abstract Well interference has become a common phenomenon with the increasing scale of horizontal well fracturing. Recent studies on well interference in horizontal wells do not properly reflect the physical model of the postfracturing well groups and the realistic fracturing process of infill wells. Establishing the correspondence between well interference causative factors and manifestations is of great significance for infill well deployment and secondary oil recovery. In this work, we develop a numerical model that considers low velocity non-Darcy seepage in shale reservoirs to study the inter-well interference phenomenon that occurs in the Santanghu field, and construct an explicit hydraulic fracture… More >