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Hydrologic and water quality performance of alaboratory scale bioretention unit

Jun Xia, Hongping Wang, RichardL. Stanford, Guoyan Pan, Shaw L. Yu

《环境科学与工程前沿（英文）》 2018年 第12卷 第1期 doi: 10.1007/s11783-018-1011-5

摘要： A bioretention unit (BRU) or cell is a green infrastructurepractice that is widely used as a low impact development (LID) techniquefor urban stormwater management. Bioretention is considered a goodfit for use in China’s sponge city construction projects. However,studies on bioretention design, which incorporates site-specific environmentaland social-economic conditions in China are still very much needed.In this study, an experimental BRU, consisted of two cells plantedwith and ,was tested with eighteen synthesizedstorm events. Three levels (high, median, low) of flows and concentrationsof pollutants (TN, TP and COD) were fed to the BRU and the performanceof which was examined. The results showed that the BRU not only delayedand lowered the peak flows but also removed TN, TP and COD in variousways and to different extents. Under the high, medium and low inflowrate conditions, the outflow peaks were delayed for at least 13 minutesand lowered at least 52%. The two cells stored a maximum of 231 mmand 265 mm for turf grass and respectively. For both cells the total depth available for storagewas 1,220 mm, including a maximum 110 mm deep ponding area. The largestinfiltrate rate was 206 mm/h for both cells with different plants.For the eighteen events, TP and COD were removed at least 60% and42% by mean concentration, and 65% and 49% by total load, respectively.In the reservoir layer, the efficiency ratio of removal of TN, TPand COD were 52%, 8% and 38%, respectively, within 5 days after runoffevents stopped. Furthermore, the engineering implication of the hydrologicaland water quality performances in sponge city construction projectsis discussed.

关键词： Bioretention unit     Spongecity     Stormwater runoff     Peak reduction     Pollutant removal    

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Migration and fate of polycyclic aromatic hydrocarbons in bioretention systems with different media:

《环境科学与工程前沿（英文）》 2023年 第18卷 第4期 doi: 10.1007/s11783-024-1802-9

摘要：

● Bioretention systems showed > 92% load reduction rates of PAHs.

关键词： Bioretention     Polycyclic aromatic hydrocarbons     HYDRUS-1D     Model simulation     Migration    

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Hydrologic experiments and modeling of two laboratory bioretention systems under different boundary conditions

Ruifen Liu, Elizabeth Fassman-Beck

《环境科学与工程前沿（英文）》 2017年 第11卷 第4期 doi: 10.1007/s11783-017-0951-5

摘要： Hydrologic performance of bioretention systems is significantly influenced by the media composition and underdrain configuration. This research measured hydrologic performance of column-scale bioretention systems during a synthetic design storm of 25.9 mm, assuming a system area:catchment area ratio of 5%. The laboratory experiments involved two different engineered media and two different drainage configurations. Results show that the two engineered media with different sand aggregates were able to retain about 36% of the inflow volume with free drainage configuration. However, the medium with marine sand is better at delaying the occurrence of drainage than the one with pumice sand, denoting the better detention ability of the former. For both engineered media, an underdrain configuration with internal water storage (IWS) zone lowered drainage volume and peak drainage rate as well as delayed the occurrence of drainage and peak drainage rate, as compared to a free drainage configuration. The USEPA SWMM v5.1.11 model was applied for the free drainage configuration case, and there is a reasonable fit between observed and modeled drainage-rates when media-specific characteristics are available. For the IWS drainage configuration case, air entrapment was observed to occur in the engineered medium with marine sand. Filling of an IWS zone is most likely to be influenced by many factors, such as the structure of the bioretention system, medium physical and hydraulic properties, and inflow characteristics. More research is needed on the analysis and modeling of hydrologic process in bioretention with IWS drainage configuration.

关键词： Bioretention     Hydrologic process     Underdrain configuration     SWMM     Modeling    

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A critical literature review of bioretention research for stormwater management in cold climate and future

Hannah Kratky, Zhan Li, Yijun Chen, Chengjin Wang, Xiangfei Li, Tong Yu

《环境科学与工程前沿（英文）》 2017年 第11卷 第4期 doi: 10.1007/s11783-017-0982-y

摘要： Bioretention is a popular best management practice of low impact development that effectively restores urban hydrologic characteristics to those of predevelopment and improves water quality prior to conveyance to surface waters. This is achieved by utilizing an engineered system containing a surface layer of mulch, a thick soil media often amended with a variety of materials to improve water quality, a variety of vegetation, and underdrains, depending on the surrounding soil characteristics. Bioretention systems have been studied quite extensively for warm climate applications, but data strongly supporting their long-term efficacy and application in cold climates is sparse. Although it is apparent that bioretention is an effective stormwater management system, its design in cold climate needs further research. Existing cold climate research has shown that coarser media is required to prevent concrete frost from forming. For spring, summer and fall seasons, if sufficient permeability exists to drain the system prior to freezing, peak flow and volume reduction can be maintained. Additionally, contaminants that are removed via filtration are also not impacted by cold climates. In contrary, dissolved contaminants, nutrients, and organics are significantly more variable in their ability to be removed or degraded via bioretention in colder temperatures. Winter road maintenance salts have been shown to negatively impact the removal of some contaminants and positively impact others, while their effects on properly selected vegetation or bacteria health are also not very well understood. Research in these water quality aspects has been inconsistent and therefore requires further study.

关键词： Bioretention     Cold climate     Low impact development     Stormwater    

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A solution to stochastic unit commitment problem for a wind-thermal system coordination

B. SARAVANAN,Shreya MISHRA,Debrupa NAG

《能源前沿（英文）》 2014年 第8卷 第2期   页码 192-200 doi: 10.1007/s11708-014-0306-x

摘要： Unit commitment (UC) problem is one of the most important decision making problems in power system. In this paper the UC problem is solved by considering it as a real time problem by adding stochasticity in the generation side because of wind-thermal co-ordination system as well as stochasticity in the load side by incorporating the randomness of the load. The most important issue that needs to be addressed is the achievement of an economic unit commitment solution after solving UC as a real time problem. This paper proposes a hybrid approach to solve the stochastic unit commitment problem considering the volatile nature of wind and formulating the UC problem as a chance constrained problem in which the load is met with high probability over the entire time period.

关键词： unit commitment (UC)     randomness     wind generation     univariate     chance constrained    

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Solving unit commitment problem using a novel version of harmony search algorithm

Roozbeh MORSALI,Tohid JAFARI,Amirhossein GHODS,Mohammad KARIMI

《能源前沿（英文）》 2014年 第8卷 第3期   页码 297-304 doi: 10.1007/s11708-014-0309-7

摘要： In this context, a novel structure was proposed for improving harmony search (HS) algorithm to solve the unit comment (UC) problem. The HS algorithm obtained optimal solution for defined objective function by improvising, updating and checking operators. In the proposed improved self-adaptive HS (SGHS) algorithm, two important control parameters were adjusted to reach better solution from the simple HS algorithm. The objective function of this study consisted of operation, start-up and shut-down costs. To confirm the effectiveness, the SGHS algorithm was tested on systems with 10, 20, 40 and 60 generating units, and the obtained results were compared with those of the simple HS algorithm and other related works.

关键词： generation scheduling     harmony search (HS) algorithm     intelligent technique     unit commitment    

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A solution to the unit commitment problem—a review

B. SARAVANAN, Siddharth DAS, Surbhi SIKRI, D. P. KOTHARI

《能源前沿（英文）》 2013年 第7卷 第2期   页码 223-236 doi: 10.1007/s11708-013-0240-3

摘要： Unit commitment (UC) is an optimization problem used to determine the operation schedule of the generating units at every hour interval with varying loads under different constraints and environments. Many algorithms have been invented in the past five decades for optimization of the UC problem, but still researchers are working in this field to find new hybrid algorithms to make the problem more realistic. The importance of UC is increasing with the constantly varying demands. Therefore, there is an urgent need in the power sector to keep track of the latest methodologies to further optimize the working criterions of the generating units. This paper focuses on providing a clear review of the latest techniques employed in optimizing UC problems for both stochastic and deterministic loads, which has been acquired from many peer reviewed published papers. It has been divided into many sections which include various constraints based on profit, security, emission and time. It emphasizes not only on deregulated and regulated environments but also on renewable energy and distributed generating systems. In terms of contributions, the detailed analysis of all the UC algorithms has been discussed for the benefit of new researchers interested in working in this field.

关键词： unit commitment (UC)     optimization     deterministic load     stochastic load     evolutionary programming (EP)     hybrid    

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Energy saving design of the machining unit of hobbing machine tool with integrated optimization

《机械工程前沿（英文）》 2022年 第17卷 第3期 doi: 10.1007/s11465-022-0694-2

摘要： The machining unit of hobbing machine tool accounts for a large portion of the energy consumption during the operating phase. The optimization design is a practical means of energy saving and can reduce energy consumption essentially. However, this issue has rarely been discussed in depth in previous research. A comprehensive function of energy consumption of the machining unit is built to address this problem. Surrogate models are established by using effective fitting methods. An integrated optimization model for reducing tool displacement and energy consumption is developed on the basis of the energy consumption function and surrogate models, and the parameters of the motor and structure are considered simultaneously. Results show that the energy consumption and tool displacement of the machining unit are reduced, indicating that energy saving is achieved and the machining accuracy is guaranteed. The influence of optimization variables on the objectives is analyzed to inform the design.

关键词： energy saving design     energy consumption     machining unit     integrated optimization     machine tool    

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Low crosstalk switch unit for dense piezoelectric sensor networks

Lei QIU, Shenfang YUAN,

《机械工程前沿（英文）》 2009年 第4卷 第4期   页码 401-406 doi: 10.1007/s11465-009-0047-4

摘要： Structural health monitoring (SHM), on the basis of piezoelectric (PZT) sensors and lamb wave method, is efficient in estimating the state of monitored structures. Furthermore, to monitor large-scale structures, dense piezoelectric sensor networks are required, which usually contain many piezoelectric sensor pairs called actuator-sensor channels. In that case, considering the few data acquisition channels especially in the data acquisition board with a high sampling rate and limited quantity of signal amplifiers used in an integrated computer system, a switch unit is adopted to switch to different channels. Because of the high frequency and power of the lamb wave excitation signal, there exists a crosstalk signal in the switch unit. A large crosstalk signal is mixed into the response signal so that the on/off-line signal processing task is difficult to achieve. This paper first analyzes the crosstalk signal phenomenon, describes its production mechanism, and proposes a method to reduce it. Then a 24-switch channel low crosstalk switch unit based on a digital I/O board PCI7248 produced by Adlink technology is developed. An experiment is implemented to validate it. Its low crosstalk characteristics make it promote the real application of the SHM based active lamb wave method. Finally, a general software program based on LabVIEW software platform is developed to control this switch unit.

关键词： structural health monitoring (SHM)     piezoelectric (PZT) sensor networks     switch unit     crosstalk signal    

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Ensemble unit and AI techniques for prediction of rock strain

Pradeep T; Pijush SAMUI; Navid KARDANI; Panagiotis G ASTERIS

《结构与土木工程前沿（英文）》 2022年 第16卷 第7期   页码 858-870 doi: 10.1007/s11709-022-0831-3

摘要： The behavior of rock masses is influenced by a variety of forces, with measurement of stress and strain playing the most critical roles in assessing deformation. The laboratory test for determining strain at each location within rock samples is expensive and difficult but rock strain data are important for predicting failure of rock material. Many researchers employ AI technology in order to solve these difficulties. AI algorithms such as gradient boosting machine (GBM), support vector regression (SVR), random forest (RF), and group method of data handling (GMDH) are used to efficiently estimate the strain at every point within a rock sample. Additionally, the ensemble unit (EnU) may be utilized to evaluate rock strain. In this study, 3000 experimental data are used for the purpose of prediction. The obtained strain values are then evaluated using various statistical parameters and compared to each other using EnU. Ranking analysis, stress-strain curve, Young’s modulus, Poisson’s ratio, actual vs. predicted curve, error matrix and the Akaike’s information criterion (AIC) values are used for comparing models. The GBM model achieved 98.16% and 99.98% prediction accuracy (in terms of values of R2) in the longitudinal and lateral dimensions, respectively, during the testing phase. The GBM model, based on the experimental data, has the potential to be a new option for engineers to use when assessing rock strain.

关键词： prediction     strain     ensemble unit     rank analysis     error matrix    

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Performance design of a cryogenic air separation unit for variable working conditions using the lumped

Jinghua XU, Tiantian WANG, Qianyong CHEN, Shuyou ZHANG, Jianrong TAN

《机械工程前沿（英文）》 2020年 第15卷 第1期   页码 24-42 doi: 10.1007/s11465-019-0558-6

摘要： Large-scale cryogenic air separation units (ASUs), which are widely used in global petrochemical and semiconductor industries, are being developed with high operating elasticity under variable working conditions. Different from discrete processes in traditional machinery manufacturing, the ASU process is continuous and involves the compression, adsorption, cooling, condensation, liquefaction, evaporation, and distillation of multiple streams. This feature indicates that thousands of technical parameters in adsorption, heat transfer, and distillation processes are correlated and merged into a large-scale complex system. A lumped parameter model (LPM) of ASU is proposed by lumping the main factors together and simplifying the secondary ones to achieve accurate and fast performance design. On the basis of material and energy conservation laws, the piecewise-lumped parameters are extracted under variable working conditions by using LPM. Takagi–Sugeno (T–S) fuzzy interval detection is recursively utilized to determine whether the critical point is detected or not by using different thresholds. Compared with the traditional method, LPM is particularly suitable for “rough first then precise” modeling by expanding the feasible domain using fuzzy intervals. With LPM, the performance of the air compressor, molecular sieve adsorber, turbo expander, main plate-fin heat exchangers, and packing column of a 100000 Nm O /h large-scale ASU is enhanced to adapt to variable working conditions. The designed value of net power consumption per unit of oxygen production (kW/(Nm O )) is reduced by 6.45%.

关键词： performance design     air separation unit (ASU)     lumped parameter model (LPM)     variable working conditions     T–S fuzzy interval detection    

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A solution to unit commitment problem using invasive weed optimization algorithm

B. SARAVANAN, E. R. VASUDEVAN, D. P. KOTHARI

《能源前沿（英文）》 2013年 第7卷 第4期   页码 487-494 doi: 10.1007/s11708-013-0279-1

摘要： Unit commitment (UC) is one of the most important aspect of power generation in the world today. Though, there is no method to find the exact optimized solution, there exists several meta-heuristic algorithms to determine the close to exact solution. This paper proposes a novel solution to effectively determine UC and generation cost using the technique of invasive weed optimization (IWO). The existing technique distributes the load demand among all the generating units. The method proposed here utilizes the output of UC obtained by using the Lagrangian relaxation (LR) method and calculates the required generation from only the plants that are ON discarding the OFF generator units and thereby giving a faster and more accurate response. Moreover, the results show the comparison between the LR-particle swarm optimization (PSO) and LR-IWO, and prove that the cost of generation for a 4 unit, 8 hour schedule is much less in the case of IWO when compared to PSO.

关键词： Lagrangian relaxation (LR)     invasive weed optimization (IWO)     economic dispatch     optimization     fuel cost     seed     fitness    

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A building unit decomposition model for energy leakage by infrared thermography image analysis

Yan SU, Fangjun HONG, Lianjie SHU

《能源前沿（英文）》 2020年 第14卷 第4期   页码 901-921 doi: 10.1007/s11708-020-0679-y

摘要： A quantitative energy leakage model was developed based on the thermography image data measured for both external and internal building surfaces. The infrared thermography images of both surfaces of doors, windows, and walls of an office building in the Hengqin Campus of University of Macao were taken at various times in a day for four seasons. The transient heat flux for sample units were obtained based on measurements of the seasonal transient local temperature differences and calculations of the effective thermal conductivity from the multiple-layer porous medium conduction model. Effects of construction unit types, orientations, and seasons were quantitatively investigated with unit transient orientation index factors. The corresponding electric energy consumption was calculated based on the air conditioning system coefficient of performance of heat pump and refrigerator cycles for different seasons. The model was validated by comparing to the electric meter records of energy consumption of the air conditioning system. The uncertainties of the predicted total building energy leakage are about 14.7%, 12.8%, 12.4%, and 15.8% for the four seasons, respectively. The differences between the predicted electric consumption and meter values are less than 13.4% and 5.4% for summer and winter, respectively. The typical daily thermal energy leakage value in winter is the highest among the four seasons. However, the daily electric energy consumption by the air conditioning system in summer and autumn is higher than that in winter. The present decomposition model for energy leakage is expected to provide a practical tool for quantitative analysis of energy leakage of buildings.

关键词： heat conductivity     heat coefficient     heat &fllig     ux     infrared thermography     thermal image    

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Enhanced photoelectrochemical water splitting with a donor-acceptor polyimide

《能源前沿（英文）》 doi: 10.1007/s11708-023-0910-8

摘要： Polyimide (PI) has emerged as a promising organic photocatalyst owing to its distinct advantages of high visible-light response, facile synthesis, molecularly tunable donor-acceptor structure, and excellent physicochemical stability. However, the synthesis of high-quality PI photoelectrode remains a challenge, and photoelectrochemical (PEC) water splitting for PI has been less studied. Herein, the synthesis of uniform PI photoelectrode films via a simple spin-coating method was reported, and their PEC properties were investigated using melamine as donor and various anhydrides as acceptors. The influence of the conjugate size of aromatic unit (phenyl, biphenyl, naphthalene, perylene) of electron acceptor on PEC performance were studied, where naphthalene-based PI photoelectrode exhibited the highest photocurrent response. This is resulted from the unification of wide-range light absorption, efficient charge separation and transport, and strong photooxidation capacity. This paper expands the material library of polymer films for PEC applications and contributes to the rational design of efficient polymer photoelectrodes.

关键词： polyimide (PI) film     photoelectrochemistry     band structure engineering     aromatic unit    

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Allocation of grassland, livestock and arable based on the spatial and temporal analysis for food demand in China

Huilong LIN, Ruichao LI, Yifan LIU, Jingrong ZHANG, Jizhou REN

《农业科学与工程前沿（英文）》 2017年 第4卷 第1期   页码 69-80 doi: 10.15302/J-FASE-2017140

摘要： To explore the distribution of food demand and the projected trend in future food demand in China, this paper analyzed the change in current (1998–2012) per-capita demand for grain, grain-consuming and herbivorous livestock products, and predicted the food demand in 2020. The results indicated that in 1998–2012, the national per-capita consumption of grain ration declined by about 36.66%, and the per-capita consumption of grain-consu-ming and herbivorous livestock products increased by about 48% and 34.09%, respectively. The grain-consu-ming livestock products have become the primary source of both calories and protein for consumers. The proportion of herbivorous livestock products in consumer diets has increased steadily and there has been huge potential in substituting beef and mutton for pork in this dynamic market. The demand for food in different provinces of China is highly variable, which is important for planning grassland agriculture development and ensuring food safety. The demand for grain, and grain-consuming and herbivorous livestock products will increase by about 3.3%, 20% and 14% respectively by 2020. Based on the food demand and trend in the development of grassland agriculture, the 31 provinces in China are divided into three priority groups for grassland agriculture development.

关键词： arable land equivalent unit (ALEU)     food equivalent unit (FEU)     food security     grassland agriculture     time trend prediction    

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标题 作者 时间 类型 操作

Hydrologic and water quality performance of alaboratory scale bioretention unit

Jun Xia, Hongping Wang, RichardL. Stanford, Guoyan Pan, Shaw L. Yu

期刊论文

Migration and fate of polycyclic aromatic hydrocarbons in bioretention systems with different media:

期刊论文

Hydrologic experiments and modeling of two laboratory bioretention systems under different boundary conditions

Ruifen Liu, Elizabeth Fassman-Beck

期刊论文

A critical literature review of bioretention research for stormwater management in cold climate and future

Hannah Kratky, Zhan Li, Yijun Chen, Chengjin Wang, Xiangfei Li, Tong Yu

期刊论文

A solution to stochastic unit commitment problem for a wind-thermal system coordination

B. SARAVANAN,Shreya MISHRA,Debrupa NAG

期刊论文

Solving unit commitment problem using a novel version of harmony search algorithm

Roozbeh MORSALI,Tohid JAFARI,Amirhossein GHODS,Mohammad KARIMI

期刊论文

A solution to the unit commitment problem—a review

B. SARAVANAN, Siddharth DAS, Surbhi SIKRI, D. P. KOTHARI

期刊论文

Energy saving design of the machining unit of hobbing machine tool with integrated optimization

期刊论文

Low crosstalk switch unit for dense piezoelectric sensor networks

Lei QIU, Shenfang YUAN,

期刊论文

Ensemble unit and AI techniques for prediction of rock strain

Pradeep T; Pijush SAMUI; Navid KARDANI; Panagiotis G ASTERIS

期刊论文

Performance design of a cryogenic air separation unit for variable working conditions using the lumped

Jinghua XU, Tiantian WANG, Qianyong CHEN, Shuyou ZHANG, Jianrong TAN

期刊论文

A solution to unit commitment problem using invasive weed optimization algorithm

B. SARAVANAN, E. R. VASUDEVAN, D. P. KOTHARI

期刊论文

A building unit decomposition model for energy leakage by infrared thermography image analysis

Yan SU, Fangjun HONG, Lianjie SHU

期刊论文

Enhanced photoelectrochemical water splitting with a donor-acceptor polyimide

期刊论文

Allocation of grassland, livestock and arable based on the spatial and temporal analysis for food demand in China

Huilong LIN, Ruichao LI, Yifan LIU, Jingrong ZHANG, Jizhou REN

期刊论文