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On-going nitrification in chloraminated drinking water distribution system(DWDS) is conditioned by hydraulics and disinfection strategies

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Journal of Environmental Sciences 2020年第10期32卷 151-162页

作者： Yi Shi Akintunde Babatunde Bettina Bockelmann-Evans Qijie Li Liang Zhang National Engineering Laboratory for Cereal Fermentation Technology Jiangnan UniversityWuxi 214122China Discipline of Ciuil Engineering Cardiff University School of EngineeringThe ParadeCardiffCF243AAUK School of Civil Engineering University of LeedsLeedsLS29JTUK

Within the drinking water distribution system(DWDS)using chloramine as disinfectant,nitrification caused by nitrifying bacteria is increasingly becoming a concern as it poses a great challenge for maintaining water *** investigate efficient control strategies,operational conditions including hydraulic regimes and disinfectant scenarios were controlled within a flow cell experimental *** test phases were conducted to investigate the effects on the extent of nitrification of three flow rates(Q=2,6,and 10 L/min)and four disinfection scenarios(total Cl2=1 mg/L,Cl2/NH3-N=3:1;total Cl2=1 mg/L,Cl2/NH3-N=5:1;total Cl2=5 mg/L,Cl2/NH3-N=3:1;and total Cl2=5 mg/L,Cl2/NH3-N=5:1).Physico-chemical parameters and nitrification indicators were monitored during the *** characteristics of biofilm extracellular polymetric substance(EPS)were evaluated after the *** main results from the study indicate that nitrification is affected by hydraulic conditions and the process tends to be severe when the fluid flow transforms from laminar to turbulent(2300

关键词： Nitrification Drinking water distribution system(DWDS) Biofilm hydraulics Disinfection

Non-contact cylindrical rotating triboelectric nanogenerator for harvesting kinetic energy from hydraulics

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Nano Research 2020年第7期13卷 1903-1907页

作者： Nan Zhang Cheng Qin Tianxing Feng Jun Li Zhirui Yang Xiupeng Sun Erjun Liang Yanchao Mao Xudong Wang MOE Key Laboratory of Materials Physics School of Physics and MicroelectronicsZhengzhou UniversityZhengzhou 450001China Department of Materials Science and Engineering University of Wisconsin-MadisonMadisonWI53706USA

hydraulics provide a unique and widely existed mechanical energy source around us,such as in water or oil pipes,and ***,a non-contact cylindrical rotating triboelectric nanogenerator(TENG)was developed to harvest the mechanical energy from water *** of the TENG was based on the non-contact free-rotating between a curved Cu foil and a flexible nanostructured fluorinated ethylene propylene(FEP)polymer *** free-standing distance between two rotating interfaces avoided abrading of electrode *** TENG was able to effectively convert mechanical energy of the water flow into *** driven by water flow,the output voltage and current of the TENG reached 1,670 V and 13.4 uA,*** any energy storage component,the produced electricity could instantaneously power 12 white light emitting diodes(LEDs)bulbs and a digital *** non-contact rotating TENG would provide new opportunities for harvesting energy from many types of hydraulics as a self-sustainable power source for sensing,detection,and protection.

关键词： mechanical energy hydraulics triboelectric nanogenerator nanowire thin films non-contact

Characteristics of helical flow in slim holes and calculation of hydraulics for ultra-deep wells

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Petroleum Science 2010年第2期7卷 226-231页

作者： Fu Jianhong Yang Yun Chen Ping Zhao Jinhai State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum University ChengduSichuan 610500 China Changqing Engineering Technology Research Institute Chuanqing Drilling Engineering Company Limited Xi＇an Shaanxi710021 China Drilling Technology Research Institute SINOPEC Shengli Oilfield Dongying Shandong 257017 China

Due to the slim hole at the lower part of the ultra-deep and deep wells, the eccentricity and rotation of drill string and drilling fluid properties have great effects on the annular pressure drop. This leads to the fact that conventional computational models for predicting circulating pressure drop are inapplicable to hydraulics design of deep wells. With the adoption of helical flow theory and H-B rheological model, a computational model of velocity and pressure drop of non-Newtonian fluid flow in the eccentric annulus was established for the cases where the drill string rotates. The effects of eccentricity, rotation of the drill string and the dimensions of annulus on pressure drop in the annulus were analyzed. Drilling hydraulics was given for an ultra-deep well. The results show that the annular pressure drop decreases with an increase in eccentricity and rotary speed, and increases with a decrease in annular flow area. There is a great difference between static mud density and equivalent circulating density during deep well drilling.

关键词： Ultra-deep well slim hole annular velocity annular pressure drop hydraulics

Hydraulic Geometry,hydraulics and Sediment Properties of Forest Brooks after Extensive Erosion from Upland Peatland Drainage

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Open Journal of Modern Hydrology 2012年第3期2卷 59-69页

作者： Hannu Marttila Simo Tammela Bjorn Klove Water Resources and Environmental Engineering Laboratory University of OuluOuluFinland

Peatland drainage can affect headwater systems, causing changes in bed substrate composition and hydraulic geome-try in small brooks. We studied hydraulic geometry and sediment properties in 14 boreal forest brook reaches (width < 2 m), characterised by well-vegetated banks, high sinuosity and low width-to-depth ratio, in north-east Finland. The aims were to obtain information from channel geometry and to study brook response to extensive sediment load from land use. The results indicate that bed sediment in brooks is almost continuously mobile, which negatively reflect to ecological status of the brooks. These headwater meandering parts have limited sediment transport capacity and require a long period to recover from artificially increased sediment input from peat drainage. However, different reaches can be prioritised for restoration according to the characteristics of silted bed sediment or sediment origins. Brook width appeared to have large natural variation, causing great local velocity variations. This needs to be taken into consideration when restoring straightened reaches in small headwater areas, e.g., width in restored reaches cannot be uniform but should include variations.

关键词： Forest Brook Headwater Hydraulic Geometry hydraulics Peatland Drainage Sediment

Junction matters in hydraulic circuit bio-design of microfluidics

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Bio-Design and Manufacturing 2023年第1期6卷 38-50页

作者： Yao Lin Dongliang He Zerui Wu Yurou Yao Zhanhao Zhang Yuheng Qiu Shan Wei Guangzhu Shang Xingyue Lei Ping Wu Weiping Ding Liqun He Department of Thermal Science and Energy Engineering University of Science and Technology of ChinaHefei 230027China School of Chemistry and Materials Science University of Science and Technology of ChinaHefei 230027China GeneMind Biosciences Company Limited Shenzhen 518023China Department of Electronic Engineering and Information Science University of Science and Technology of ChinaHefei 230027China

Microfluidic channels are at micrometer scales;thus,their fluid flows are laminar,resulting in the linear dependence of pressure drop on flow rate in the length of the *** ratio of the pressure drop to flow rate,referred to as resistance,depends on channel size and dynamic ***,a microfluidic chip is analogous to an electric circuit in design,but the design is adjusted to optimize channel ***,whereas voltage loss is negligible at the nodes of an electric circuit,hydraulic pressure drops at the nodes of microfluidic chips by a magnitude are comparable to the pressure drops in the straight ***,we prove by experiment that one must fully consider the pressure drops at nodes so as to accurately design a precise microfluidic *** the process,we numerically calculated the pressure drops at hydraulic nodes and list their resistances in the range of flows as *** resorted to machine learning to fit the calculated results for complex ***,we obtained a library of node resistances for common junctions and used them to design three established chips that work for single-cell analysis and for precision allocation of solutes(in gradient and averaging concentration microfluidic networks).Endothelial cells were stimulated by generating concentrations of adriamycin hydrochloride from the last two microfluidic networks,and we analyzed the response of endothelial *** results indicate that consideration of junction resistances in design calculation brings experimental results closer to the design values than *** approach may therefore contribute to providing a platform for the precise design of organ chips.

关键词： Junctions hydraulics Microfluidic chip design

Seasonal variation of tidal prism and energy in the Changjiang River estuary： a numerical study

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Chinese Journal of Oceanology and Limnology 2016年第1期34卷 219-230页

作者：张敏 Ian Howard TOWNEND 蔡华阳周云轩 State Key Laboratory of Estuarine and Coastal Research East China Normal University Shanghai 200062 China Ocean and Earth Sciences University of Southampton Southampton SO171B J UK Department of Water Management Faculty of Civil Engineering and Geosciences Delft University of Technology Stevinweg 1 P.O. Box 5048 2600 GA Delft The Netherlands

Tidal rivers are intrinsically complex because tidal propagation is influenced by river discharge. This study aims to examine the seasonal variation of tidal prism and energy variance in the tidal river of the Changjiang(Yangtze) River estuary in China. In order to quantify the behaviour of river and tide,we use numerical modelling that has been validated using measured data. We conduct our analysis by quantifying the discharge and energy variance in separate components for both the river and the tide,during wet and dry seasons. We note various definitions of tidal prism and explore the difference between tidal discharge on the flood and ebb and tidal storage volume. The results show that the river discharge attenuates the tidal motion and reduces the tidal flood discharge but the tidal storage volume is approximately constant with different riverine discharge since part of the fresh water discharge is intercepted and captured in the estuary due to the backwater effect. It appears that the tidal discharge adjusts according to the variation of river discharge to keep a constant tidal storage volume. An analysis of the hydraulics shows that the transition from tidal dominance(at the mouth) to river dominance(upstream) depends on the location of tidal current reversal which varies from wet season to dry season. Duringthe wet season,the Changjiang River estuary is totally dominated by energy from fresh water discharge.

关键词： hydrodynamics estuary convergence tidal prism hydraulics energy tidal river

Leaf habit differentiation explains trait tradeoffs across savanna woody plants

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Forest Ecosystems 2024年第3期11卷 287-295页

作者： Yangsiding Wang Da Yang German Vargas G. Guangyou Hao Jennifer S.Powers Yan Ke Qin Wang Yunbing Zhang Jiaolin Zhang CAS Key Laboratory of Tropical Forest Ecology Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesMenglaYunnan 666303China University of Chinese Academy of Sciences Beijing 100049China School of Biological Sciences University of UtahSalt Lake CityUT 84112USA CAS Key Laboratory of Forest Ecology and Management Institute of Applied EcologyChinese Academy of SciencesShenyang 110016China Department of Ecology Evolution and BehaviorUniversity of MinnesotaSt PaulMN 55108USA

Identifying how leaf habit subdivisions link to the fast–slow and avoidance–tolerance trait tradeoffs can provide new insight into divergence in ecophysiological strategies among plant functional groups. Here, we tested a hypothesis that the differentiation across deciduous, semi-deciduous and evergreen woody species contributes to physiological trait tradeoffs in a dry-hot valley savanna. We investigated 11 photosynthetic, morphological and hydraulic traits of 24 species including 8 deciduous, 10 semi-deciduous and 6 evergreen species. Deciduous species were grouped in the fast and avoidance side associated with high values of maximum photosynthetic rates,stomatal conductance and leaf size, while evergreen species were grouped in the slow and tolerance side associated with high photosynthetic water use efficiency, leaf mass per area, sapwood density, Huber value, leaf water potential at turgor loss point and water potential causing 50% loss of stem hydraulic conductance. Semideciduous species generally had intermediate trait values and represented different physiological characteristics when compared to deciduous and evergreen species. The physiological trait tradeoffs showed a close linkage to the differentiation of these three leaf habits. Our findings clearly reveal trait tradeoffs related to fast–slow and avoidance–tolerance strategies among diverse savanna plants, suggesting a syndrome in multiple ecophysiology strategies across different leaf habits.

关键词： Dry-hot habitat Gas exchange hydraulics Phenology Tolerance Valley savanna

River bank protection from ship-induced waves and river flow

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Water Science and Engineering 2019年第2期12卷 129-135页

作者： Sahameddin Mahmoudi Kurdistani Giuseppe R. Tomasicchin Felice D’Alessandro Leila Hassanabadi Department of Engineering for Innovation University of Salento

A new equation is proposed for the design of armor units on protected river banks under the combined action of ship-induced waves and river *** observed field and experimental data in the literature have been examined and a valuable database has been *** conditions,including the river water depth,flow velocity,river bank slope,Froude number,wave height,wave period,and wave obliquity have been *** from an empirical equation (Bhowmik,1978) that only considers the maximum wave height and river bank slope have been compared with the results calculated by the newly developed *** results have also been verified against field *** show that not only the maximum wave height and river bank slope but also the water depth,flow velocity,wave length,wave obliquity,and wave period are important parameters for predicting the mean diameter of the armor units,highlighting the multivariate behavior of protecting the river bank in the presence of ship-induced waves and river flow velocity.

关键词： River bank protection hydraulics Ship-induced waves River flow velocity Wave period Wave obliquity Multivariate phenomenon

Investigation of Controlling Factors for Growth in Stromatolites of the Tieling Formation,Jixian,Tianjin

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Acta Geologica Sinica(English Edition) 2017年第1期91卷 347-348页

作者： HUANG Min LU Chenming JIANG Zikun LIU Benpei CHU Zhihui ZHAO Yanxu Chinese Academy of Geological Sciences Beijing 100037 China China University of Geosciences Beijing 100083 China School of Ocean and Earth Science Tongji University Shanghai 200092 China Seismic Station of Luoyang Henan Province Luoyang 471021 Henan China

Objective The Yan-Liao Aulacogen is located in the northern SinoKorean Plate,buried under huge Meso-Neoproterozoic sedimentation,and is widely distributed in Beijing,Tianjin and *** these strata,several microbial mats occur,represented by four stromatolite assemblages within the Upper Precambrian stratotype section at Jixian,Tianjin.

关键词： STROMATOLITES SEDIMENTARY structures hydraulics WATER depth WATER currents SEDIMENTATION & deposition