Guolin Li^*

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.3, pp. 549-559, 2020, DOI:10.32604/fdmp.2020.09219 - 25 May 2020

Abstract The rational design of heating ventilation and air conditioning systems is an important means to achieve energy conservation and sustainable development. The simulation of air-conditioning systems with finite element methods has gradually become an important auxiliary means of complex airspace design. In this paper, a k-ε turbulence model is used to conduct 3D simulations and optimize the summer air conditioning system of a lecture hall. Various conditions are considered in terms of fresh air temperature and flow rate towards the end to improve comfort. The approach used in this paper could also be used in More >

Daoming Shen^1,2,*, Chao Gui¹, Jinhong Xia¹, Songtao Xue^2,3

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.3, pp. 489-500, 2020, DOI:10.32604/fdmp.2020.08969 - 25 May 2020

Abstract The performances of a refrigeration unit relying on compressors working in parallel have been investigated considering the influence of the compressor volumetric efficiency and isentropic efficiency on the compression ratio. Moreover, the following influential factors have been taken into account: evaporation temperature, condensation temperature and compressor suction-exhaust pressure ratio for different opening conditions of the compressor. The following quantities have been selected as the unit performance measurement indicators: refrigeration capacity, energy efficiency ratio (COP), compressor power consumption, and refrigerant flow rate. The experimental results indicate that the system refrigeration capacity and COP decrease with a More >

Jing Sun^1,2,3,*, Dehua Liu^1,2,3, Xiang Zhu^1,2,3, Wenjun Huang^1,2,3, Liang Cheng^1,2,3

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.3, pp. 425-440, 2020, DOI:10.32604/fdmp.2020.08531 - 25 May 2020

Abstract Low permeability tight sandstone reservoirs have a high filtrational resistance and a very low fluid flow rate. As a result, the propagation speed of the formation pressure is low and fluid flow behaves as a non-Darcy flow, which typically displays a highly non-linear behavior. In this paper, the characteristics and mechanism of pressure propagation in this kind of reservoir are revealed through a laboratory pressure propagation experiment and through data from an actual tight reservoir development. The main performance mechanism is as follows: A new pressure cage concept is proposed based on the pressure variation… More >

Yifei Wei^{1, *}, Yu Gong¹, Qiao Li¹, Mei Song^{1, *}, Xiaojun Wang²

CMC-Computers, Materials & Continua, Vol.64, No.1, pp. 501-514, 2020, DOI:10.32604/cmc.2020.010048 - 20 May 2020

Abstract In this paper, maximizing energy efficiency (EE) through radio resource allocation for renewable energy powered heterogeneous cellular networks (HetNet) with energy sharing, is investigated. Our goal is to maximize the network EE, conquer the instability of renewable energy sources and guarantee the fairness of users during allocating resources. We define the objective function as a sum weighted EE of all links in the HetNet. We formulate the resource allocation problem in terms of subcarrier assignment, power allocation and energy sharing, as a mixed combinatorial and non-convex optimization problem. We propose an energy efficient resource allocation More >

Nithya Rekha Sivakumar^{1, *}

CMC-Computers, Materials & Continua, Vol.64, No.1, pp. 81-96, 2020, DOI:10.32604/cmc.2020.08851 - 20 May 2020

Abstract In the past few decades, Energy Efficiency (EE) has been a significant challenge in Wireless Sensor Networks (WSNs). WSN requires reduced transmission delay and higher throughput with high quality services, it further pays much attention in increased energy consumption to improve the network lifetime. To collect and transmit data Clustering based routing algorithm is considered as an effective way. Cluster Head (CH) acts as an essential role in network connectivity and perform data transmission and data aggregation, where the energy consumption is superior to non-CH nodes. Conventional clustering approaches attempts to cluster nodes of same… More >

Marion Thébault¹, Larysa Kutuzova², Sandra Jury¹, Iris Eicher¹, Edith-Martha Zikulnig-Rusch¹, Andreas Kandelbauer^2,*

Journal of Renewable Materials, Vol.8, No.6, pp. 603-630, 2020, DOI:10.32604/jrm.2020.09616 - 12 May 2020

Abstract Here, the effects of substituting portions of fossil-based phenol in phenol formaldehyde resin by renewable lignin from two different sources are investigated using a factorial screening experimental design. Among the resins consumed by the wood-based industry, phenolics are one of the most important types used for impregnation, coating or gluing purposes. They are prepared by condensing phenol with formaldehyde (PF). One major use of PF is as matrix polymer for decorative laminates in exterior cladding and wet-room applications. Important requirements for such PFs are favorable flow properties (low viscosity), rapid curing behavior (high reactivity) and… More >

Sheng Xiao^{1, 2, *}, Jing Selena He³, Xi Yang⁴, Yazhe Wang¹, Lu Jin¹

CMC-Computers, Materials & Continua, Vol.63, No.3, pp. 1357-1371, 2020, DOI:10.32604/cmc.2020.09929 - 30 April 2020

Abstract As nanoscale processing becomes the mainstream in IC manufacturing, the crosstalk problem rises as a serious challenge, not only for energy-efficiency and performance but also for security requirements. In this paper, we propose a register reallocation algorithm called Nearby Access based Register Reallocation (NARR) to reduce the crosstalk between instruction buses. The method includes construction of the software Nearby Access Aware Interference Graph (NAIG), using data flow analysis at assembly level, and reallocation of the registers to the software. Experimental results show that the crosstalk could be dramatically minimized, especially for 4C crosstalk, with a More >

Xiaoli He^{1, 2}, Hong Jiang^{1, *}, Yu Song^{1, 3}, Muhammad Owais⁴

CMC-Computers, Materials & Continua, Vol.63, No.3, pp. 1273-1296, 2020, DOI:10.32604/cmc.2020.09908 - 30 April 2020

Abstract This paper investigates the power control and routing problem in the communication process of an energy harvesting (EH) multi-hop cognitive radio network (CRN). The secondary user (SU) nodes (i.e., source node and relay nodes) harvest energy from the environment and use the energy exclusively for transmitting data. The SU nodes (i.e., relay nodes) on the path, store and forward the received data to the destination node. We consider a real world scenario where the EH-SU node has only local causal knowledge, i.e., at any time, each EH-SU node only has knowledge of its own EH… More >

Qin Liu^*, Ruliang Zhang

Energy Engineering, Vol.117, No.2, pp. 89-98, 2020, DOI:10.32604/EE.2020.010373 - 23 April 2020

Abstract With the development of urbanization in China, the problem of garbage disposal has become increasingly serious. Among the existing waste treatment technologies, pyrolysis is an emerging treatment technology, which has obvious advantages in terms of reduction and secondary pollution. It has good development prospects. This article first compares the advantages and disadvantages of various existing waste treatment technologies, and proposes an organization method that combines thermogravimetric analysis, kinetic analysis, tube furnace experiments, and domestic waste pyrolysis and low-calorie heat the decomposed gases burn together. Urban garbage is one of the main pollution sources of modern… More >

Wuxiong Zhang^{1, 2}, Weidong Fang^{1, 2, *}, Qianqian Zhao^{1, 2}, Xiaohong Ji³, Guoqing Jia³

CMC-Computers, Materials & Continua, Vol.63, No.2, pp. 787-811, 2020, DOI:10.32604/cmc.2020.07620 - 01 May 2020

Abstract Energy efficiency is very important for the Internet of Things (IoT), especially for front-end sensed terminal or node. It not only embodies the node’s life, but also reflects the lifetime of the network. Meanwhile, it is also a key indicator of green communications. Unfortunately, there is no article on systematic analysis and review for energy efficiency evaluation in IoT. In this paper, we systemically analyze the architecture of IoT, and point out its energy distribution, Furthermore, we summarized the energy consumption model in IoT, analyzed the pros and cons of improving energy efficiency, presented a More >