INTEGRATED STEADY-STATE AND DYNAMIC SIMULATION OF MULTI-UNIT AIR CONDITIONERS BASED ON TWO-PHASE FLUID NETWORK MODEL

HONGBO XU,SHUANGQUAN SHAO,Huiming Zou,Changqing Tian 대한설비공학회 2012 International Journal Of Air-Conditioning and Refr Vol.20 No.4

An integrated simulation model is developed to investigate the steady-state and dynamic performance of multi-unit air conditioners (MUACs). It is built as two-phase fluid network which is able to describe different systems by incidence matrixes. And the submodels are embedded in the system framework, where the submodels can be either steady-state or dynamic model, distributed parameter or lumped parameter model. For this case, the numerical submodels are employed with moving-boundary models of condenser and evaporator, steady-state models of compressor and electronic expansion valve. The comparison with experimental data shows that it cannot only predict the steady-state performance, but also catch dynamic trends with high accuracy, for example, the differences of evaporating pressure < ${\pm}4%$, condensing pressure < ${\pm}3%$, compressor discharge temperature < ${\pm}4^{\circ}C$, superheating degree < ${\pm}2^{\circ}C$ and subcooling degree < ${\pm}1^{\circ}C$. Therefore, the simulation model is confirmed as an effective tool to analyze the steady and transient characteristics and optimize the design and control algorithm of MUACs.

An Interactive Strategy of Grid and Electric Vehicles Based on Master‑Slaves Game Model

Hongbo Cheng,Tong Luo,Chen Kang,Jianbo Xin,Hua Wan,Feng Pei,Xu Tian 대한전기학회 2020 Journal of Electrical Engineering & Technology Vol.15 No.1

In order to avoid the adverse efects of the grid caused by disorder large-scale electric vehicles and improve supporting function of energy storage battery on the power grid, interaction model of electric vehicles (EVs) and the power grid is constructed according to a master-slave game method. Then, the utility functions of each participant are established, and the dynamic constraints of the batteries for EVs are established considering the travel demand of users. Then, based on the YALMIP/CPLEX solver, the optimal response strategy of the EVs can be obtained, and the genetic algorithm is used to solve the Nash equilibrium solution of the master-slaves game model. Moreover, the Monte Carlo method is employed to simulate the user travel data and the basic parameters of EVs in a certain area. Based on these data, the optimal time-of-use price in this area is ofered, and the optimal response strategy of EVs under this price is analyzed. Finally, the study of the case show that the proposed game model can make the strategies of both the EVs and the grid, which can restrict the load fuctuation of the grid and improve the beneft of EVs without afecting their travel.

Structural behavior of aluminum reticulated shell structures considering semi-rigid and skin effect

Hongbo Liu,Zhihua Chen,Shuai Xu,Yidu Bu 국제구조공학회 2015 Structural Engineering and Mechanics, An Int'l Jou Vol.54 No.1

The aluminum dome has been widely used in natatorium, oil storage tank, power plant, coal, as well as other industrial buildings and structures. However, few research has focused on the structural behavior and design method of this dome. At present, most designs of aluminum alloy domes have referred to theories and methods of steel spatial structures. However, aluminum domes and steel domes have many differences, such as elasticity moduli, roof structures, and joint rigidities, which make the design and analysis method of steel spatial structures not fully suitable for aluminum alloy dome structures. In this study, a stability analysis method, which can consider structural imperfection, member initial curvature, semi-rigid joint, and skin effect, was presented and used to study the stability behavior of aluminum dome structures. In addition, some meaningful conclusions were obtained, which could be used in future designs and analyses of aluminum domes.

Expression and Efficient Purification of Tag-cleaved Active Recombinant Human Insulin-like Growth Factor-II from Escherichia coli

Hongbo Li,Xiaoyan Hui,Peng Li,Aimin Xu,Shiwu Li,Shouguang Jin,Donghai Wu 한국생물공학회 2015 Biotechnology and Bioprocess Engineering Vol.20 No.2

Insulin-like growth factor-II (IGF2) is a growth factor for the control of cell proliferation and apoptosis. To explore the clinical use of human IGF2, an efficient method for production of a large amount of active recombinant hIGF2 is necessary. Human IGF2 cDNA was cloned into pET32 vector where it is under the control of an IPTGinducible T7 promoter. High level soluble thioredoxin (Trx)- hIGF2 fusion protein was produced at room temperature following IPTG induction, amounting up to 20% of the total soluble bacterial proteins. The recombinant TrxhIGF2 fusion protein was purified to an approximate 95% purity using Ni+-NTA affinity chromatography with an overall yield of 120 mg protein per liter of bacterial culture. After cleavage of the Trx fusion fragment by recombinant enterokinase, the tag-free recombinant hIGF2 protein (rhIGF2) was purified by passage through the Ni+-NTA affinity column again. Biological activity of the purified hIGF2 was determined by its ability to support NIH/3T3 cells proliferation and to activate AKT signaling pathways. Our results demonstrate that tag-free active rhIGF2 can easily be obtained for various applications from E. coli using the procedure described in this report.

Robustness Improvement for Adaptive Full Order Observer in Sensorless Induction Motor Drives

Hongbo Wang,Wei Sun,Yong Yu,Gaolin Wang,Dianguo. Xu 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6

The performance of adaptive full order observer for speed sensorless induction motor drives can be improved further though it has been researched for many years. A novel speed estimation algorithm with estimated rotor flux error and the corresponding feedback gain design method are proposed in this paper. Through Lyapunov’s theorem, the stability of proposed speed estimation algorithm is proved. The sensitivity of speed estimation to motor parameter deviation is reduced. Finally the feasibility of proposed two methods is verified by experiments.

Altered Protein Expression Patterns of Mycobacterium tuberculosis Induced by ATB107

Hongbo Shen,Enzhuo Yang,Feifei Wang,Ruiliang Jin,Shengfeng Xu,Qiang Huang,Honghai Wang 한국미생물학회 2010 The journal of microbiology Vol.48 No.3

ATB107 is a potent inhibitor of indole-3-glycerol phosphate synthase (IGPS). It can effectively inhibit the growth of clinical isolates of drug-resistant Mycobacterium tuberculosis strains as well as M. tuberculosis H37Rv. To investigate the mechanism of ATB107 action in M. tuberculosis, two-dimensional gel electrophoresis coupled with MALDI-TOF-MS analysis (2-DE-MS) was performed to illustrate alterations in the protein expression profile in response to ATB107. Results show that ATB107 affected tryptophan biosynthesis by decreasing the expression of protein encoded by Rv3246c, the transcriptional regulatory protein of MtrA belonging to the MtrA-MtrB two-component regulatory system, in both drug-sensitive and drug-resistant virulent strains. ATB107 might present a stress condition similar to isoniazid (INH) or ethionamide for M. tuberculosis since the altered expression in response to ATB107 of some genes, such as Rv3140, Rv2243, and Rv2428, is consistent with INH or ethionamide treatment. After incubation with ATB107, the expression of 2 proteins encoded by Rv0685 and Rv2624c was down-regulated while that of protein encoded by Rv3140 was up-regulated in all M. tuberculosis strains used in this study. This may be the common response to tryptophan absence; however, relations to ATB107 are unknown and further evaluation is warranted.

An efficient process for co-production of γ-aminobutyric acid and probiotic Bacillus subtilis cells

Hongbo Wang,Jinge Huang,Lei Sun,Fuchao Xu,Wei Zhang,Jixun Zhan 한국식품과학회 2019 Food Science and Biotechnology Vol.28 No.1

This study was to establish an integrated processfor the co-production of c-aminobutyric acid (GABA) andlive probiotics. Six probiotic bacteria were screened andBacillus subtilis ATCC 6051 showed the highest GABAproducingcapacity. The optimal temperature and initial pHvalue for GABA production in B. subtilis were found to be30 C and 8.0, respectively. A variety of carbon andnitrogen sources were tested, and potato starch and peptonewere the preferred carbon and nitrogen sources for GABAproduction, respectively. The concentrations of carbonsource, nitrogen source and substrate (sodium L-glutamate)were then optimized using the response surface methodology. The GABA titer and concentration of viable cells ofB. subtilis reached 19.74 g/L and 6.0 9 108 cfu/mL at120 h. The GABA titer represents the highest production ofGABA in B. subtilis. This work thus demonstrates a highlyefficient co-production process for GABA and probiotic B. subtilis cells.

Structural behavior of aluminum reticulated shell structures considering semi-rigid and skin effect

Liu, Hongbo,Chen, Zhihua,Xu, Shuai,Bu, Yidu Techno-Press 2015 Structural Engineering and Mechanics, An Int'l Jou Vol.54 No.1

The aluminum dome has been widely used in natatorium, oil storage tank, power plant, coal, as well as other industrial buildings and structures. However, few research has focused on the structural behavior and design method of this dome. At present, most designs of aluminum alloy domes have referred to theories and methods of steel spatial structures. However, aluminum domes and steel domes have many differences, such as elasticity moduli, roof structures, and joint rigidities, which make the design and analysis method of steel spatial structures not fully suitable for aluminum alloy dome structures. In this study, a stability analysis method, which can consider structural imperfection, member initial curvature, semi-rigid joint, and skin effect, was presented and used to study the stability behavior of aluminum dome structures. In addition, some meaningful conclusions were obtained, which could be used in future designs and analyses of aluminum domes.

A half subcarrier guard band spectrum assignment scheme for multi-user FBMC systems

( Wei Huang ),( Hongbo Xu ),( Zhongnian Li ) 한국인터넷정보학회 2022 KSII Transactions on Internet and Information Syst Vol.16 No.1

Traditionally, in multi-user multi-carrier systems, the neighboring subband will be gapped by one subcarrier, which is set as guard band to reduce multiple access interference (MAI) between neighboring subbands. The empty subcarrier for guard band will degrade the spectral efficiency of the whole system. In order to enhance the spectral efficiency of multi-user filter bank multiple carrier (FBMC) systems, a new subband allocation method is introduced, in which the neighboring subband is gapped by half subcarrier instead of one subcarrier. Meanwhile, in order to implement the proposed resource allocation scheme, an optimized FBMC prototype filter is designed to decrease the inter-subband interference to the neighboring subband. The detailed simulations about the comparison between the proposed spectrum assignment and traditional FBMC are given, as well as the performance in the different interference scenarios. The simulation results show that the combination of the proposed spectrum assignment scheme and the optimized filter has better performance compared to the traditional scheme. The proposed scheme can be used in the system which serves massive users to get higher spectrum efficiency.

Platelet Nitrogen and Sulfur Co-doped Ordered Mesoporous Carbon with Inexpensive Methylene Blue as a Single Precursor for Electrochemical Detection of Herbicide Amitrole

Shenghai Zhou,Hongbo Xu,Yanjun Wei,Jing Gao,Yue Feng,Ning Wang,Junfeng Gao 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.8

Heteroatom-doped ordered mesoporous carbons (OMCs) have currently been considered as promising electrode materials for electrochemical sensors due to the combined advantages of ordered mesoporous materials and heteroatom-doped carbon materials. Herein, a novel nitrogen and sulfur co-doped OMCs (N,S-OMC) has been prepared via a nanocasting strategy with an inexpensive methylene blue as single precursor. The obtained mesoporous carbon has platelet morphology, short mesoporous channel together with a large surface area (549 m2/g) as well as rich N- and S-containing functional groups (6.8 at.% N and 2.3 at.% S). Compared with the graphene (GR) and carbon nanotube (CNT) electrode material, the N,S-OMC exhibited a higher electrochemical activity towards the oxidation of herbicide amitrole, ascribable to N,S-OMC's open mesoporous structures and abundant electroactive defect sites on the carbon skeleton. And, an amitrole electrochemical sensor with N,S-OMC modified electrode as working electrode was fabricated, exhibiting a good selectivity, stability, reproducibility and wide linear range of 3–750 μM. Moreover, the N,S-OMC-based electrochemical sensor was proved feasible in river water sample analyses, showing a satisfied recovery ranging from 97.03% to 105.42%. The results not only demonstrate cheap methylene blue can be used as single precursor for the N,S-OMC preparation, but also confirm the N,S-OMC is promising in amitrole sensor fabrication.