作者机构：
[Zhao, Fu-Yun; Cai, Yang; Zhang, Dong-Dong] Wuhan Univ, Minist Educ, Key Lab Hydraul Machinery Transients, Wuhan, Hubei, Peoples R China.;[Zhao, Fu-Yun; Cai, Yang; Zhang, Dong-Dong] Wuhan Univ, Hubei Key Lab Waterjet Theory & New Technol, Wuhan, Hubei, Peoples R China.;[Zhao, Fu-Yun; Cai, Yang; Zhang, Dong-Dong] Wuhan Univ, Sch Power & Mech Engn, Wuhan, Hubei, Peoples R China.;[Liu, Di] China Univ Petr, Coll Pipeline & Civil Engn, Qingdao, Shandong, Peoples R China.;[Wang, Han-Qing] Univ South China, Sch Civil Engn, Hengyang, Hunan, Peoples R China.
通讯机构：
[Zhao, Fu-Yun] W;[Liu, Di] C;Wuhan Univ, Sch Power & Mech Engn, Wuhan, Hubei, Peoples R China.;China Univ Petr, Coll Pipeline & Civil Engn, Qingdao, Shandong, Peoples R China.
关键词：
Air source energy;Domestic water heating;Low energy built ventilation;Thermoelectric heat pumps
摘要：
An air-source thermoelectric heat pump (AS-THP) system is proposed in the present work, and it actively exploits ambient air source energy serving for cold air delivery and hot water supply simultaneously. A mathematical model, combining thermoelectric theory and the effectiveness-number of transfer units (ε-NTU), is firstly conducted to predict the performance of AS-THP system. Subsequently, the effects of thermoelectric input current, inlet air/water temperatures, thermal conductance, mass flow rate in both cold and hot sides, and the number of thermoelectric coolers on the performance of AS-THP system are sensitively investigated. Modeling results demonstrate that the thermal conductance and specific heat allocations in heat exchanger hot and cold sides could put heavy effects on the total cooling capacity (Qc,all), coefficient of performance (COP), outlet water temperature (Tc,out) and outlet air temperature (Th,out). Further modeling on the thermal parameters in both sides has shown that overall efficiency of AS-THP system could be achieved to nearly 90%. Also, with the increase of unit number, the cooling load for each thermoelectric unit would be reduced while the input power increases inversely. Present research could be beneficial for extensive utilization of thermoelectric heat pump in daily life by the use of ambient air source energy.
作者机构：
[Shen, Haichen; Ke, Guojun] Univ South China, Sch Civil Engn, Hengyang 421001, Peoples R China.;[Shen, Haichen; Ke, Guojun] Univ South China, Key Lab Special High Performance Concrete, Hengyang 421001, Peoples R China.;[Yang, Pengfei] Univ South China, Sch Chem & Chem Engn, Hengyang 421001, Peoples R China.
通讯机构：
[Yang, Pengfei] U;Univ South China, Sch Chem & Chem Engn, Hengyang 421001, Peoples R China.
关键词：
basalt;mechanism;synthesis;zeolites
摘要：
Traditional hydrothermal method (TH) and alkali fusion-assisted hydrothermal method (AFH) were evaluated for the preparation of zeolites from waste basalt powder by using NaOH as the activation reagent in this study. The synthesized products were characterized by BET, XRD, FTIR and SEM. The effects of acid treatment, alkali/basalt ratio, calcination temperature and crystallization temperature on the synthesis process were studied. The results showed that AFH successfully synthesized zeolite X with higher crystallinity and no zeolite was formed by TH. The specific surface area of synthetic zeolite X was 486.46 m(2).g(-1), which was much larger than that of original basalt powder (12.12 m(2).g(-1)). Acid treatment and calcination temperature had no effect on zeolite types, but acid treatment improved the yield and quality of zeolite. Alkali/basalt ratio and crystallization temperature not only affected the crystallinity of synthesized zeolites but also affected its type. The optimum synthesis condition of zeolite X are as follows: acid treatment of 5 wt% HCl solution, NaOH/basalt ratio of 1:1, a calcination temperature of 650 degrees C and crystallization temperature of 120 degrees C. The work shows that basalt can be used as a raw material to prepare zeolite.
摘要：
A comprehensive mathematical model to simulate a serial composite process for biomass and coal co-gasification has been built. The process is divided into combustion stage and gasification stage in the same gasifier, it is a new process for the co-gasification of biomass and coal. The model is based on reaction kinetic, hydrodynamics, mass and energy balances, it is a one-dimensional, K-L three-phase, unsteady state model. The model is divided into two sub-models, one is the combustion sub-model, the other is the coal-biomass serial gasification sub-model. Combustion sub-model includes coal pyrolysis, dense phase combustion, and dilute phase combustion model. Gasification sub-model includes biomass pyrolysis, dense phase coal gasification, dense phase biomass gasification, and dilute phase gasification model. The model studies the effects of key parameters on gasification properties, including gasification temperature, S/B, B/C, and predicts the composition of product gas and gas calorific value along the reactor's axis at different time. The model predictions agree well with experimental results and can be used to study and optimize the operation of the process.
摘要：
For hierarchical corrugated sandwich structures with second-order core, the prediction error of failure behavior by existing methods becomes unacceptable with the increase of structure thickness. In this study, a novel analytical model called moderately thick plate model is developed based on Mindlin plate theory, which can be used to analyze the failure behavior of hierarchical corrugated structures with second-order core under compression or shear loads. Then, the analytical expressions of nominal stress for six competing failure modes are derived based on the moderately thick plate model. The results of six different unit structures based on the moderately thick plate model agree quite well the ones by finite element methods. Furthermore, the influence of different structure thicknesses is investigated to validate the applicability of the moderately thick plate model. According to the comparative results with the thin plate model, the proposed moderately thick plate model has a better precision with the increase of the ratio of thickness to width for failure components.
期刊：
IEEE INTERNET OF THINGS JOURNAL,2019年6(3):4782-4790 ISSN：2327-4662
通讯作者：
Wang, Minghua
作者机构：
[Deng, Xianjun; Xu, Minliang; Wang, Minghua] Univ South China, Dept Commun Engn, Hengyang 421001, Peoples R China;[Yang, Laurence T.; Lin, Man] St Francis Xavier Univ, Dept Comp Sci, Antigonish, NS B2G 2W5, Canada;[Yi, Lingzhi] Univ South China, Sch Civil Engn, Hengyang 421001, Peoples R China
通讯机构：
[Wang, Minghua] U;Univ South China, Dept Commun Engn, Hengyang 421001, Peoples R China.
关键词：
Confident information coverage (CIC);energy balance;hole repairing;Internet of Things (IoT);mobile edge computing (MEC)
摘要：
The promising Internet of Things (IoT) provides a powerful platform for practical smart applications. The limited resources of the IoT nodes as well as the emerged coverage holes pose a great challenge on the quality of service of the IoT. Mobile edge computing (MEC), which can improve the IoT nodes energy consumption efficiency and optimize the utilization effectiveness of the limited resources, provides a novel view for coping with the challenge. Based on the MEC, this paper focuses on how to solve the problem of dispatch of mobile edge nodes for confident information coverage holes repairing (DMEN-CICHR) with the goal of maximizing the network lifetime and guaranteeing the network connectivity. To deal with the DMEN-CICHR problem, we develop an energy-balanced and obstacle-adaptive mobile edge node dispatch algorithm called EBOADMEN-CICHR, which restricts the mobile edge nodes from moving too long distance by setting a bound for each CIC hole and repeatedly updating the bound by a competition mechanism. To guarantee the network connectivity, the EBOADMEN-CICHR recursively performs breadth first search on a constructed undirected graph to find all disconnected subgraphs and then dispatches some mobile edge nodes to connect those disconnected subgraphs until the whole network is connected. A number of experiments emulating the realistic scenarios in radiological pollution monitoring in uranium tailings are executed to verify the effectiveness of the proposed EBOADMEN-CICHR solution. Experimental results show the EBOADMEN-CICHR can perform better than other peer methods in term of higher energy efficiency and longer network lifetime.
作者：
Zeng, Taotao*;Rene, Eldon R.;Zhang, Shiqi;Lens, Piet N. L.
期刊：
Process Safety and Environmental Protection,2019年126:150-159 ISSN：0957-5820
通讯作者：
Zeng, Taotao
作者机构：
[Zeng, Taotao; Zhang, Shiqi] Univ South China, Hunan Prov Key Lab Pollut Control & Resources Reu, Hengyang, Peoples R China.;[Rene, Eldon R.; Zeng, Taotao; Lens, Piet N. L.] UNESCO IHE Inst Water Educ, NL-2601 DA Delft, Netherlands.
通讯机构：
[Zeng, Taotao] U;Univ South China, Hunan Prov Key Lab Pollut Control & Resources Reu, Hengyang, Peoples R China.
关键词：
Selenate;Cadmium;Anaerobic granular sludge;Autoclaved biomass;Microbial community
摘要：
The main aim of this work was to evaluate the simultaneous removal of Se(VI) and Cd(II) by anaerobic granular sludge in batch tests. The anaerobic sludge completely removed 10 mg/L Se(VI) and 20 mM (1800 mg/L) lactate within 1.5 d of batch incubation. After 7 d of incubation, 90.7% and 87.7% of 5 mg/L Cd(II) were removed by the sludge in, respectively, the absence or presence of Se(VI). Compared to experiments with autoclaved biomass, Se(VI) and total Se removal 98% and 70 was mainly due to bioreduction instead of adsorption onto anaerobic granular sludge. The increase in the protein and polysaccharide content of the extracellular polymeric substances (EPS) contributed to the adsorption of total Se and Cd(II). The predominant bacterial composition of the samples from the different treatments was similar. However, the abundance of genera in the microbial community gradually changed over the treatment time depending on the Se and/or Cd exposure. Se, as an environmental factor, had a positive impact on the dominance of the Methanosaeta, Syntrophobacter and Methanobacterium genera, while Cd had a positive impact on the dominance of the Methanosaeta genus. (C) 2019 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.
期刊：
IEEE INTERNET OF THINGS JOURNAL,2019年6(6):9217-9225 ISSN：2327-4662
通讯作者：
Deng, Xianjun
作者机构：
[Dai, Lu; Wang, Bang] Huazhong Univ Sci & Technol, Sch Elect Informat & Commun, Wuhan 430074, Hubei, Peoples R China.;[Yang, Laurence T.] St Francis Xavier Univ, Dept Comp Sci, Antigonish, NS B2G2W5, Canada.;[Deng, Xianjun] Univ South China, Sch Elect Engn, Hunan Prov Key Lab Ultra Fast Micro Nano Technol, Hengyang 421001, Peoples R China.;[Yi, Lingzhi] Univ South China, Sch Civil Engn, Hengyang 421001, Peoples R China.
通讯机构：
[Deng, Xianjun] U;Univ South China, Sch Elect Engn, Hunan Prov Key Lab Ultra Fast Micro Nano Technol, Hengyang 421001, Peoples R China.
关键词：
Confident information coverage (CIC);genetic algorithms (GEAs);Industrial Internet of Things (IIoT);Internet of Things (IoT) node deployment;network lifetime
摘要：
The ever-growing Industrial Internet of Things (IoT) provides a powerful method to sense a series of critical industrial environments. This paper studies how to deploy the fixed number of IoT nodes so that the network lifetime is maximized in a sensing field with obstacles while guaranteeing the requirements of confident information coverage, network connectivity, energy efficiency, fault tolerance, and reliability. An IoT node deployment scheme based on an improved nature-inspired genetic algorithm is proposed to solve the defined constrained optimization problem. In the proposed IoT node deployment scheme, we utilize a population initialization based on the Delaunay triangulation to generate the better initial population, a chromosome modification operation to achieve both connectivity and coverage for each chromosome and a chromosome mirror-crossover operation to produce the better offsprings. Experimental results show that our deployment schema equips better performance in terms of longer network lifetime and comparable coverage ratio compared with the other four peer algorithms.
期刊：
Numerical Heat Transfer, Part B: Fundamentals,2019年75(4):265-288 ISSN：1040-7790
通讯作者：
Zhao, Fu-Yun
作者机构：
[Wang, Lei; Zhang, Dong-Dong; Zhao, Fu-Yun] Wuhan Univ, Minist Educ, Key Lab Hydraul Machinery Transients, Wuhan, Hubei, Peoples R China;[Wang, Lei; Zhang, Dong-Dong; Zhao, Fu-Yun] Wuhan Univ, Hubei Key Lab Waterjet Theory & New Technol, Wuhan, Hubei, Peoples R China;[Wang, Lei; Zhang, Dong-Dong; Zhao, Fu-Yun] Wuhan Univ, Sch Power & Mech Engn, Wuhan 430072, Hubei, Peoples R China;[Liu, Di] China Univ Petr, Coll Pipeline & Civil Engn, Qingdao, Shandong, Peoples R China;[Wang, Han-Qing] Univ South China, Sch Civil Engn, Hengyang, Hunan, Peoples R China
通讯机构：
[Zhao, Fu-Yun] W;Wuhan Univ, Sch Power & Mech Engn, Wuhan 430072, Hubei, Peoples R China.
摘要：
In former theoretical researches of nanofluid flows, numerical investigations could not agree with experimental observations, particularly regarding whether the mixing nanoparticles will enhance or deteriorate the heat transfer. In the present work, thermal driven buoyancy flows of nanofluids in a square enclosure were modeled by the use of homogeneous assumptions and the effective kinematic viscosity and thermal conductivity formulas. Thoroughly developed heat transfer coefficient is subsequently proposed, aiming to critically evaluate the performance of nanofluid heat transport. Numerical results are presented over a wide range of thermal Rayleigh number (10(3) <= Ra <= 10(6)) and nanoparticles volume fraction (0.001 <= phi <= 0.04). Present modeling results accurately predict both the enhancement and deterioration of the natural convection heat transfer, fully validated by former experimental observations. Overall, mathematical models and Nusselt number definitions proposed in the present work effectively enhance the reliability of numerical modeling researches on the nanofluid heat transfer. Present clarification research on the Nusselt unifications could benefit future development of thermal carrier fluid enhanced by nano-particles.
