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Isolation and phylogenetic analysis of heterotrophic nitrobacteria

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Journal of Harbin Institute of Technology(New Series) 2008年第6期15卷 790-793页

作者：苏俊峰马放郭静波侯宁高珊珊王弘宇 School of municipal and environmental engineering Harbin Institute of Technology School of environmental and municipal engineering Xi'an University of Architecture and Technology dept.of municipal engineering Wuhan University

A method about the isolation of heterotrophic nitrosobactria and the characteristics of heterotrophic nitrosobactria were *** can be seen from the fluorescence in situ hybridization results of the bio-membrane sample from the bio-ceramic reactor,the spots of green nitrosobacteria are obviously more than those of orange *** heterotrophic nitrobacteria were isolated from the bio-ceramic *** sequencing 16SrDNA and establishing the phylogenic tree,they were identified physiologically and biochemically as Pseudomonas sp..After 12 d,the COD removal efficiency of wgy55 and wgy68 were 45.03% and 50.85%,the NH4-N removal efficiency of them were 80.12% and 85.93%,and the TN removal efficiency of them were 69.71% and 64.7%.The final concentration of NO2-N of wgy55 and wgy68 was 0.753 mg/L and 0.601 mg/L,and that of NO3-N was 3.21 mg/L and 3.38 mg/*** results show that wgy55 and wgy68 have the capability of nitrification and they are heterotrophic nitrobacteria.

关键词： bio-ceranfic reactor fluorescence in situ hybridization heterotrophic nitrification

Performance of Sewage Sludge Treatment and Electricity Generation by Different Configuration Microbial Fuel Cells

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Journal of Harbin Institute of Technology(New Series) 2013年第4期20卷 1-6页

作者： Jun-Qiu Jiang Kun Wang Xue-Xuan Peng Qing-Liang Zhao Yun-Shu Zhang Xiu-Dong Zhou dept.of municipal and environmental & engineering Harbin Institute of Technology Institute of Fuzhou Electric Power Design

This paper compared the degradation efficiency of sludge organic matters and electric-production by two typical microbial fuel cells——dual-chamber microbial fuel cell(DMFC)and single chamber air cathode microbial fuel cell(SAMFC),and the variations of sludge protein,polysaccharide and ammonia nitrogen within the systems were also *** results showed that the concentration of sludge soluble chemical oxygen demand,protein and carbohydrate of DMFC are higher than these of SAMFC during the systems operation,while DMFC can achieve a better ammonia nitrogen removal than *** the same operation condition,the stable voltage output of DMFC and SAMFC is 0.61 V and 0.37 V;the maximum power density of DMFC and SAMFC is 2.79 W/m3and 1.25 W/m3;TCOD removal efficiency of DMFC and SAMFC is 34.14%and 28.63%for 12 d,***,DMFC has a higher coulomb efficiency than SAMFC,but both are less than5%.The results showed that DMFC present a better performance on sludge degradation and electric-production.

关键词： sewage sludge dual-chamber microbial fuel cell(DMFC) single chamber air cathode microbial fuel cell(SAMFC) degradation electricity production

Experimental study of vibration mitigation of mast arm signal structures with particle-thrust damping based tuned mass damper

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Earthquake engineering and engineering Vibration 2019年第1期18卷 219-231页

作者： Zhang Yunfeng Liu Heng dept.of Civil & environmental engineering University of Maryland College Park

Large amplitude vibration of mast arm structures due to wind loads are the primary contributing factor to the reduced fatigue life of signal support structures. To alleviate this problem of wind-induced in-plane vibration of mast arm signal structures, a particle-thrust damping based turned mass damper(PTD-TMD) device is adopted and its damping effect is characterized experimentally. The particle-thrust damping is a passive damping device that does not require electric power and is temperature independent. Based on the calibration test, an equivalent dynamic model of the PTD-TMD device is developed and used for numerical simulation study. The damping effects of this PTD-TMD device on signal support structures was investigated through both numerical analysis and laboratory testing of a 50-ft(15.24 m) mast arm structure including both free vibration and forced vibration tests. The experimental test and numerical study results show that vibration response behavior of mast arm signal support structures can be significantly reduced by installing the PTD-TMD that can increase the critical damping ratio of the mast arm signal structures to 4%. The stress range at the welded connection between the mast arm and traffic pole is also reduced.

关键词： fatigue mast arm signal support structures tuned mass damper vibration

Modeling and cyclic behavior of segmental bridge column connected with shape memory alloy bars

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Earthquake engineering and engineering Vibration 2012年第3期11卷 375-389页

作者： Hwasung Roh Andrei M.Reinhorn Jong Seh Lee dept.of Civil and environmental engineering Hanyang University dept.of Civil Structural and Environmental EngineeringUniversity at Buffalo The State University of New York

This paper examines the quasi-static cyclic behavior, lateral strength and equivalent damping capacities of a system of post-tensioned segmental bridge columns tied with large diameter martensitic Shape Memory Alloy （SMA） link-bars. Moment-curvature constitutive relationships are formulated and analysis tools are developed for the PT column, including a modified four-spring model prepared for the SMA bars. The suggested system is exemplified using a column with an aspect ratio of 7.5 and twelve 36.5 mm diameter NiTi martensitic SMA bars. A post-tensioning force of 40% to 60% of the tendon yield strength is applied in order to obtain a self re-centering system, considering the residual stress of the martensitie SMA bars. The cyclic response results show that the lateral strength remains consistently around 10% of the total vertical load and the equivalent viscous damping ratios reach 10%-12% of critical. When large diameter NiTi superelastic SMA bars are incorporated into the column system, the cyclic response varies substantially. The creep behavior of the superelastic SMA bar is accounted for since it affects the re-centering capability of the column. Two examples are presented to emphasize the modeling sensitivities for these special bars and quantify their cyclic behavior effects within the column assembly.

关键词： segmental rocking columns shape memory alloy bars cyclic response energy dissipation damping recentering

Removal of nickel from spent electroless nickel-plating bath with nickel foam cathode

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Journal of Harbin Institute of Technology(New Series) 2002年第4期9卷 332-335页

作者：于秀娟郑彤魏杰周定 dept.of environmental engineering and Science

The electrochemical method was used to remove nickel ion from spent electroless nickel plating bath (pH=5 3). An electrolytic cell was composed of a porous nickel foam cathode and an inert RuO 2/Ti anode. Nickel ions were reduced and deposited on the surface of the nickel foam cathode. The effect of current density (i), linear velocity of wastewater(v), gap between cathode and anode(d C/A) and reaction time(t) on nickel removal rate and current efficiency were studied. As reaction time prolonged, nickel removal rate increased while current efficiency decreased. And larger v and smaller d C/A can enhance nickel removal rate and increase current efficiency by promoting mass transfer and dropping concentration polarization. The effect of current density on nickel removal by electrochemistry was related to other parameters. After three hours’ electrolysis with i=1 0 A/dm2, v=18 5 cm/min and d C/A=0 5 cm, nickel removal rate and current efficiency reached 85 6% and 29 1%, respectively.

关键词： spent electroless nickel plating bath electrochemical treatment nickel foam cathode

Probabilistic characterization of cyclic shear modulus reduction for normally to moderately over-consolidated clays

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Earthquake engineering and engineering Vibration 2016年第3期15卷 495-508页

作者： Iok-Tong Ng Ka-Veng Yuen Ngai-Kuan Lao dept.of Civil and environmental engineering Faculty of Science and Technology University of Macao

Evaluation of the cyclic shear modulus of soils is a crucial but challenging task for many geotechnical earthquake engineering and soil dynamic issues. Improper determination of this property unnecessarily drives up design and maintenance costs or even leads to the construction of unsafe structures. Due to the complexities involved in the direct measurement, empirical curves for estimating the cyclic shear modulus have been commonly adopted in practice for simplicity and economical considerations. However, a systematic and robust approach for formulating a reliable model and empirical curve for cyclic shear modulus prediction for clayey soils is still lacking. In this study, the Bayesian model class selection approach is utilized to identify the most significant soil parameters affecting the normalized cyclic shear modulus and a reliable predictive model for normally to moderately over-consolidated clays is proposed. Results show that the predictability and reliability of the proposed model out performs the well-known empirical models. Finally, a new design chart is established for practical usage.

关键词： Bayesian analysis cyclic shear modulus empirical model geotechnical earthquake engineering normally tomoderately over-consolidated clays

A novel experimental setup with sand trunk for heat extraction of geothermal heat exchanger

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Journal of Harbin Institute of Technology(New Series) 2008年第6期15卷 809-813页

作者：姜益强姚杨陈益明马最良 School of municipal and environmental engineering Harbin Institute of Technology dept.of Building Service engineering Hong Kong Polytechnic University

A novel experimental setup was developed to study the heat extraction of geothermal heat exchanger(GHE)in different operational modes under adiabatic and isothermal *** experimental setup consists of a sand trunk,a tailored water chiller,a natural cold source unit,two water boxes containing hot water and cool water,and a data acquisition *** experimental results indicate that the volume flow rate of the entering water is a main factor affecting the heat extraction;furthermore,the heat extraction value per meter pipe decreases gradually along the heat extraction pipe and increases with the increase of the incoming water volume flow ***,this novel experimental setup may be helpful to further study the operation performance of GHE in different types of soil.

关键词： heat extraction GHE experimental setup sand trunk

Performance-based seismic design of nonstructural building components:The next frontier of earthquake engineering

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Earthquake engineering and engineering Vibration 2014年第S1期13卷 17-46页

作者： Andre Filiatrault Timothy Sullivan dept.of Civil Structural and environmental engineering University at BuffaloState University of New York dept.of Civil engineering & Architecture University of Pavia Assistant Professor

With the development and implementation of performance-based earthquake engineering,harmonization of performance levels between structural and nonstructural components becomes vital. Even if the structural components of a building achieve a continuous or immediate occupancy performance level after a seismic event,failure of architectural,mechanical or electrical components can lower the performance level of the entire building system. This reduction in performance caused by the vulnerability of nonstructural components has been observed during recent earthquakes worldwide. Moreover,nonstructural damage has limited the functionality of critical facilities,such as hospitals,following major seismic events. The investment in nonstructural components and building contents is far greater than that of structural components and framing. Therefore,it is not surprising that in many past earthquakes,losses from damage to nonstructural components have exceeded losses from structural damage. Furthermore,the failure of nonstructural components can become a safety hazard or can hamper the safe movement of occupants evacuating buildings,or of rescue workers entering buildings. In comparison to structural components and systems,there is relatively limited information on the seismic design of nonstructural components. Basic research work in this area has been sparse,and the available codes and guidelines are usually,for the most part,based on past experiences,engineering judgment and intuition,rather than on objective experimental and analytical results. Often,design engineers are forced to start almost from square one after each earthquake event: to observe what went wrong and to try to prevent repetitions. This is a consequence of the empirical nature of current seismic regulations and guidelines for nonstructural components. This review paper summarizes current knowledge on the seismic design and analysis of nonstructural building components,identifying major knowledge gaps that w

关键词： nonstructural building components performance-based earthquake engineering seismic design and analysis

Succession and biodiversity indices in eutrophication process of static landscaping water body in northern China

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Journal of Harbin Institute of Technology(New Series) 2008年第5期15卷 711-717页

作者：丛科明刘书宇马放张建祺任南琪 School of municipal and environmental engineering Harbin Institute of Technology Shanghai Applied Radiation Institute Shanghai University dept.of Civil and environmental engineering University of MarylandBaltimore County

Many biodiversity indices were used to indicate the biological contamination degree in studies of lake water or seawater. Some were studied on biodiversity comparison for different areas at the same time, or initial structure succession of some aerial lake water systems. The phytoplankton changed with the development of various dominant species. In this study, the dominant species at these stages were Chlorophyta in the beginning stage, Cyanophyta in the second stage, and Xanthophyta in the last stage. Seven of nine biodiversity indices (Margalef's, IE, Shannon-Wiener, Simpson's, McNaughton's, Species and Odds Measure of Diversity) showed their failure to represent the eutrophication trend, and the other two indices (Menhinick's and Monk) exhibited good efficiency to indicate the eutrophication trend for the static landscaping water body.

关键词： biodiversity indices eutrophication assessment static lake water