Influence of latitude wind pressure distribution on the responses of hyperbolodial cooling tower shell

Jun-Feng Zhang,Yao-Jun Ge,Lin Zhao 한국풍공학회 2013 Wind and Structures, An International Journal (WAS Vol.16 No.6

Interference effects are of considerable concern for group hyperboloidal cooling towers, but evaluation methods and results are different from each other because of the insufficient understanding on the structure behavior. Therefore, the mechanical performance of hyperboloidal cooling tower shell under wind loads was illustrated according to some basic properties drawn from horizontal rings and cantilever beams. The hyperboloidal cooling tower shell can be regarded as the coupling of horizontal rings and meridian cantilever beams, and this perception is beneficial for understanding the mechanical performance under wind loads. Afterwards, the mean external latitude wind pressure distribution, CP(θ), was artificially adjusted to pursue the relationship between different CP(θ) and wind-induced responses. It was found that the maximum responses in hyperboloidal cooling tower shell are primarily dominated by the non-uniformity of CP(θ) but not the local pressure amplitude CP or overall resistance/drag coefficient CD. In all the internal forces, the maximum amplitude of meridian axial tension shows remarkable sensitivity to the variation of CP(θ) and it’s also the controlling force in structure design, so it was selected as an indicator to evaluate the influence of CP(θ) on responses. Based on its sensitivity to different adjustment parameters of CP(θ), an comprehensive response influence factor, RIF, was deduced to assess the meridian axial tension for arbitrary CP(θ).

Enhanced Whole-cell Biodehydrogenation of 11β-hydroxyl Medroxyprogesterone in a Biphasic System Containing Ionic Liquid

Jun-Yao He,Pu Wang,Yu-Fen Yang,Song-Lin Xie 한국생물공학회 2011 Biotechnology and Bioprocess Engineering Vol.16 No.5

A hydrophilic ionic liquid, 1-butyl-3-methylimidazolium (L)-lactate ([bmim][lactate]), was successfully employed as a co-solvent to improve the biodehydrogenation of steroid 11β-hydroxyl medroxyprogesterone (HMP)to pregna-1,4-diene-6α-methyl-3,20-dione-11β,17α-dihydroxy (PDMDD) in an aqueous-organic biphasic system using Arthrobacter simplex UR106 cells. First, a suitable biphasic system was constituted, composed of toluene and Tris-HCl buffer (0.05 mol/L, pH 7.6) at a 0.4 (V_(org)/V_(aq))volumetric phase ratio. Investigation of biodehydrogenation with the addition of [bmim][lactate] to the aqueous phase was then performed. The results demonstrate that biodehydrogenation is more efficient in a biphasic system containing 2% [bmim][lactate] as a co-solvent compared to an aqueous-toluene two-phase system. Higher bioconversion (83.2% versus 56.4%) was observed after 16 h at a substrate concentration of 80 mg HMP in 8 mL of toluene.

Adsorption of Ammonia on Municipal Solid Waste Incinerator Bottom Ash Under the Landfill Circumstance

( Jun Yao ),( Qing Na Kong ),( Hua Yue Zhu ),( Zhen Zhang ),( Yu Yang Long ),( Dong Sheng Shen ) 한국화학공학회 2015 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.53 No.4

The adsorption characteristics of ammonia on MSWI bottom ash were investigated. The effect of the variation of the landfill environmental parameters including pH, anions and organic matter on the adsorption process was discussed. Results showed that the adsorption could be well described by pseudo-second-order kinetics and Langmuir model, with a maximum adsorption capacity of 156.2 mg/g. The optimum adsorption of ammonia was observed when the pH was 6.0. High level of ion and organic matter could restrict the adsorption to a low level. The above results suggested that MSWI bottom ash could affect the migration of ammonia in the landfill, which is related to the variation of the landfill circumstance.

Mathematical explanation on the POD applications for wind pressure fields with or without mean value components

Jun-Feng Zhang,Yao-Jun Ge,Lin Zhao,Huai Chen 한국풍공학회 2016 Wind and Structures, An International Journal (WAS Vol.23 No.4

The influence mechanism of mean value components, noted as P0, on POD applications for complete random fields PC(t) and fluctuating random fields PF(t) are illustrated mathematically. The critical philosophy of the illustration is introduction of a new matrix, defined as the correlation function matrix of P0, which connect the correlation function matrix of PC(t) and PF(t), and their POD results. Then, POD analyses for several different wind pressure fields were presented comparatively as validation. It's inevitable mathematically that the first eigenmode of PC(t) resembles the distribution of P0 and the first eigenvalue of PC(t) is close to the energy of P0, due to similarity of the correlation function matrixs of PC(t) and P0. However, the viewpoint is not rigorous mathematically that the first mode represents the mean pressure and the following modes represent the fluctuating pressure when PC(t) are employed in POD application. When PC(t) are employed, POD results of all modes would be distorted by the mean value components, and it's impossible to identify P0 and PF(t) separately. Consequently, characteristics of the fluctuating component, which is always the primary concern in wind pressure field analysis, can only be precisely identified with P0 excluded in POD.

Studies on the influence factors of wind dynamic responses on hyperbolic cooling tower shells

Jun-Feng Zhang,Qing-Shuai LIU,Yao-Jun Ge,Lin Zhao 국제구조공학회 2019 Structural Engineering and Mechanics, An Int'l Jou Vol.72 No.5

Wind induced dynamic responses on hyperbolic cooling tower (HCT) shells are complicated functions of structure and wind properties, such as the fundamental frequency fmin, damping ratio ζ, wind velocity V, correlationship in meridian direction and so on, but comprehensions on the sensitivities of the dynamic responses to these four factors are still limited and disagree from each other. Following the dynamic calculation in time domain, features of dynamic effects were elaborated, focusing on the background and resonant components σB and σR, and their contributions to the total rms value σT. The σR is always less than σB when only the maximum σT along latitude is concerned and the contribution of σR to σT varies with responses and locations, but the σR couldn’t be neglected for structural design. Then, parameters of the above four factors were artificially adjusted respectively and their influences on the gust responses were illustrated. The relationships of σR and the former three factors were expressed by fitted equations which shows certain differences from the existing equations. Moreover, a new strategy for wind tunnel tests aiming at surface pressures and the following dynamic calculations, which demands less experiment equipment, was proposed according to the influence from meridian correlationship.

Effects of stiffening rings on the dynamic properties of hyperboloidal cooling towers

Jun-Feng Zhang,Huai Chen,Yao-Jun Ge,Lin Zhao,Shi-Tang Ke 국제구조공학회 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.49 No.5

As hyperboloidal cooling towers (HCTs) growing larger and slender, they become more sensitive to gust wind. To improve the dynamic properties of HCTs and to improve the wind resistance capability, stiffening rings have been studied and applied. Although there have been some findings, the influence mechanism of stiffening rings on the dynamic properties is still not fully understood. Based on some fundamental perceptions on the dynamic properties of HCTs and free ring structures, a concept named “participation degree” of stiffening rings was proposed and the influence mechanism on the dynamic properties was illustrated. The “participation degree” is determined by the modal deform amplitude and latitude wave number of stiffening rings. Larger modal deform amplitude and more latitude waves can both result in higher participation degree and more improvement to eigenfrequencies. Also, this concept can explain and associate the pre-existing independent findings.

Study of One Kind of Extended Proportional Guidance Law

Yao Jun,Feng Hai-tao,Sun Peng 보안공학연구지원센터 2014 International Journal of Hybrid Information Techno Vol.7 No.6

One kind of extended proportional guidance law is presented. This guidance law can be used without restriction about the motion speed of missile and target, and this is a different point with the classical proportional guidance law. In the case of random alter the tracking target curvature radius, compared with classical proportional guidance law under the proper random quantity, the normal overload of trajectory is relatively small, and has certain advantage, so the study has significant reference value in actual application. And interception time and normal overload have good performance. Tracking performance for high maneuverability target is better than the classical proportional guidance law. A target intercepting simulation based on MATLAB of the proportional coefficients and line-of-sight angular velocities is generated to analyze the trajectory properties. The effect of guidance coefficients on trajectory properties is studied. Through simulation, we simplify the problem by ignoring the actual factors so that a certain level of error is expected. The situation in practical requires more in-depth analysis and research.

Study of Increment Proportional Guidance Law for High Maneuvering Target

Yao Jun,Wei Zhou Fei,Wang Xin 보안공학연구지원센터 2015 International Journal of Signal Processing, Image Vol.8 No.6

For the inadequacies of the classical proportional navigation law, the mathematical model of increment proportional navigation law is established in this paper. According to the mathematical model comes to attacking targets uniform linear motion trajectory simulation. The trajectory simulation of classical proportional navigation law and incremental proportional navigation law about attacking high maneuvering target are compared. Simulation results show that incremental proportional navigation law can reduce the meet time, and stabilize the missile desired normal overload beating phenomenon in the end of the curve, also it can hit the high maneuvering target in the design requirements, and its performance is superior to classical proportional navigation law.

Wind-excited stochastic vibration of long-span bridge considering wind field parameters during typhoon landfall

Yao-Jun Ge,Lin Zhao 한국풍공학회 2014 Wind and Structures, An International Journal (WAS Vol.19 No.4

With the assistance of typhoon field data at aerial elevation level observed by meteorological satellites and wind velocity and direction records nearby the ground gathered in Guangzhou Weather Station between 1985 and 2001, some key wind field parameters under typhoon climate in Guangzhou region were calibrated based on Monte-Carlo stochastic algorithm and Meng's typhoon numerical model. By using Peak Over Threshold method (POT) and Generalized Pareto Distribution (GPD), Wind field characteristics during typhoons for various return periods in several typical engineering fields were predicted, showing that some distribution rules in relation to gradient height of atmosphere boundary layer, power-law component of wind profile, gust factor and extreme wind velocity at 1-3s time interval are obviously different from corresponding items in Chinese wind load Codes. In order to evaluate the influence of typhoon field parameters on long-span flexible bridges, 1:100 reduced-scale wind field of type B terrain was re-illustrated under typhoon and normal conditions utilizing passive turbulence generators in TJ-3 wind tunnel, and wind-induced performance tests of aero-elastic model of long-span Guangzhou Xinguang arch bridge were carried out as well. Furthermore, aerodynamic admittance function about lattice cross section in mid-span arch lib under the condition of higher turbulence intensity of typhoon field was identified via using high-frequency force-measured balance. Based on identified aerodynamic admittance expressions, Wind-induced stochastic vibration of Xinguang arch bridge under typhoon and normal climates was calculated and compared, considering structural geometrical non-linearity, stochastic wind attack angle effects, etc. Thus, the aerodynamic response characteristics under typhoon and normal conditions can be illustrated and checked, which are of satisfactory response results for different oncoming wind velocities with resemblance to those wind tunnel testing data under the two types of climate modes.

Senwot Wharton, a new genus for the Oriental region with description of two new species from Thailand (Hymenoptera: Braconidae: Alysiinae)

Junli Yao,Cornelis van Achterberg,Michael J. Sharkey,Eric G. Chapman,Jiahua Chen 한국응용곤충학회 2019 Journal of Asia-Pacific Entomology Vol.22 No.1

SenwotWharton 1983, is a small braconid genus with only two previously described species. The genus is revised using morphological characters and a phylogenetic analysis of COI sequence. Senwot Wharton is reported for the first time from Thailand and two new species: Senwot yinxianggaoae Yao n. sp. and Senwot jiyuanyaoi Yao n. sp. are described and illustrated. A key to species of the genus Senwot is presented.