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Total stress rapid drawdown analysis of the Pilarcitos Dam failure using the finite element method

Daniel R. VANDENBERGE

《结构与土木工程前沿（英文）》 2014年 第8卷 第2期   页码 115-123 doi: 10.1007/s11709-014-0249-7

摘要： Rapid drawdown is a critical design condition for the upstream or riverside slope of earth dams and levees. A new total stress rapid drawdown method based on finite element analysis is used to analyze the rapid drawdown failure that occurred at Pilarcitos Dam in 1969. Effective consolidation stresses in the slope prior to drawdown are determined using linear elastic finite element analysis. Undrained strengths from isotropically consolidated undrained (ICU) triaxial compression tests are related directly to the calculated consolidation stresses and assigned to the elements in the model by interpolation. Two different interpretations of the undrained strength envelope are examined. Strength reduction finite element analyses are used to evaluate stability of the dam. Back analysis suggests that undrained strengths from ICU tests must be reduced by 30% for use with this rapid drawdown method. The failure mechanism predicted for Pilarcitos Dam is sensitive to the relationship between undrained strength and consolidation stress.

关键词： rapid drawdown     finite element     total stress     slope stability    

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two saturated natural soils and their saturated remoulded soils under three consolidated undrained stress

Mingjing JIANG, Haijun HU, Jianbing PENG, Serge LEROUEIL

《结构与土木工程前沿（英文）》 2011年 第5卷 第2期   页码 225-238 doi: 10.1007/s11709-011-0108-8

摘要： In this paper, an experimental investigation is conducted to study the mechanical behavior of saturated natural loess, saturated natural filling in ground fissure and their corresponding saturated remoulded soils under three consolidated undrained triaxial stress tests, namely, conventional triaxial compression test (CTC), triaxial compression test (TC) and reduced triaxial compression test (RTC). The test results show that stress-strain relation, i.e. strain-softening or strain-hardening, is remarkably influenced by the structure, void ratio, stress path and confining pressure. Natural structure, high void ratio, TC stress path, RTC stress path and low confining pressures are favorable factors leading to strain-softening. Excess pore pressure during shearing is significantly affected by stress path. The tested soils are different from loose sand on character of strain-softening and are different from common clay on excess pore water pressure behavior. The critical states in ′– space in CTC, TC and RTC tests almost lie on one line, which indicates that the critical state is independent of the above stress paths. As for remoulded loess or remoulded filling, the critical state line (CSL) and isotropic consolidation line (ICL) in -log ′ space are almost straight, while for natural loess or natural filling, in -log ′ space there is a turning point on the CSL, which is similar to the ICL.

关键词： stress paths     static liquefaction     natural soil     remoulded soil     loess     structure     total strength indices     excess pore pressure    

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Advantages of intermittently aerated SBR over conventional SBR on nitrogen removal for the treatment of digested piggery wastewater

Xiaoyan Song, Rui Liu, Lujun Chen, Baogang Dong, Tomoki Kawagishi

《环境科学与工程前沿（英文）》 2017年 第11卷 第3期 doi: 10.1007/s11783-017-0941-7

摘要： An intermittently aerated sequencing batch reactor (IASBR) and a traditional sequencing batch reactor (SBR) were parallelly constructed to treat digested piggery wastewater, which was in high NH -N concentration but in a low COD/TN ratio. Their pollutant removal performance was compared under COD/TN ratios of 1.6–3.4 d and hydraulic retention times of 5–3 d. The results showed that the IASBR removed TN, NH -N and TOC more efficiently than the SBR. The average removal rates of TN, NH -N and TOC were 83.1%, 96.5%, and 89.0%, respectively, in the IASBR, significantly higher than the corresponding values of 74.8%, 82.0%, and 86.2% in the SBR. Mass balance of organic carbon revealed that the higher TN removal in the IASBR might be attributed to its efficient utilization of the organic carbon for denitrification, since that 48.7%–52.2% of COD was used for denitrification in the IASBR, higher than the corresponding proportion of 43.1%–47.4% in the SBR. A pre-anoxic process in the IASBR would enhance the ammonium oxidation while restrict the nitrite oxidation. Anoxic duration of 40–80 min should be beneficial for achieving stable nitritation.

关键词： Anoxic stress     Carbon source     Digested piggery wastewater     Intermittently aerated SBR (IASBR)     Total nitrogen    

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Simultaneous removal of total oxidizable carbon, phosphate and various metallic ions from HO solution

《化学科学与工程前沿（英文）》 2023年 第17卷 第4期   页码 470-482 doi: 10.1007/s11705-022-2231-6

摘要： Amino-functionalized zirconia was synthesized by the co-condensation method using zirconium butanol and 3-aminopropyltriethoxy silane for the simultaneous removal of various impurities from aqueous 30% H2O2 solution. The results of Fourier transform infrared (FTIR) and Zeta potential showed that the content of N in amino-functionalized zirconia increased with the added amount of 3-aminopropyltriethoxy silane. Accordingly, the removal efficiency of total oxidizable carbon, phosphate and metallic ions from the H2O2 solution increased. The adsorbent with an N content of 1.62% exhibited superior adsorption performance. The removal efficiency of 82.7% for total oxidizable carbon, 34.2% for phosphate, 87.1% for Fe3+, 83.2% for Al3+, 55.1% for Ca2+ and 66.6% for Mg2+, with a total adsorption capacity of 119.6 mg·g–1, could be achieved. The studies conducted using simulated solutions showed that the adsorption process of phosphate on amino-functionalized zirconia is endothermic and spontaneous, and the behaviors could be well described by the pseudo-second-order model and Langmuir model with a maximum adsorption capacity of 186.7 mg·g–1. The characterizations of the spent adsorbents by Zeta potential, FTIR and X-ray photoelectron spectroscopy revealed that the adsorption mechanism of phosphate is predominantly electrostatic attraction by the protonated functional groups and complementary ligand exchange with zirconium hydroxyl groups.

关键词： adsorption     zirconia     total oxidizable carbon     phosphate     metallic ions     hydrogen peroxide    

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Implementation of total Lagrangian formulation for the elasto-plastic analysis of plane steel frames

Bing XIA, Yuching WU, Zhanfei HUANG

《结构与土木工程前沿（英文）》 2012年 第6卷 第3期   页码 257-266 doi: 10.1007/s11709-012-0163-9

摘要： In this paper, the co-rotational total Lagrangian forms of finite element formulations are derived to perform elasto-plastic analysis for plane steel frames that either experience increasing external loading at ambient temperature or constant external loading at elevated temperatures. Geometric nonlinearities and thermal-expansion effects are considered. A series of programs were developed based on these formulations. To verify the accuracy and efficiency of the nonlinear finite element programs, numerical benchmark tests were performed, and the results from these tests are in a good agreement with the literature. The effects of the nonlinear terms of the stiffness matrices on the computational results were investigated in detail. It was also demonstrated that the influence of geometric nonlinearities on the incremental steps of the finite element analysis for plane steel frames in the presence of fire is limited.

关键词： co-rotational     total Lagrangian     geometrical nonlinearity     fire     elasto-plastic    

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Exergy and exergoeconomic analyses for integration of aromatics separation with aromatics upgrading

《化学科学与工程前沿（英文）》 2023年 第17卷 第2期   页码 183-193 doi: 10.1007/s11705-022-2192-9

摘要： Methanol to aromatics produces multiple products, resulting in a limited selectivity of xylene. Aromatics upgrading is an effective way to produce more valuable xylene product, and different feed ratios generate discrepant product distributions. This work integrates the aromatics separation with toluene disproportionation, transalkylation of toluene and trimethylbenzene, and isomerization of xylene and trimethylbenzene. Exergy and exergoeconomic analyses are conducted to give insights in the splitting ratios of benzene, toluene and heavy aromatics for aromatics upgrading. First, a detailed simulation model is developed in Aspen HYSYS. Then, 300 splitting ratio sets of benzene and toluene for conversion are studied to investigate the process performances. The results indicate that there are different preferences for the splitting ratios of benzene and toluene in terms of exergy and exergoeconomic performances. The process generates lower total exergy destruction when the splitting ratio of toluene varies between 0.07 and 0.18, and that of benzene fluctuates between 0.55 and 0.6. Nevertheless, the process presents lower total product unit cost with the splitting ratio of toluene less than 0.18 and that of benzene fluctuating between 0.44 and 0.89. Besides, it is found that distillation is the biggest contributor to the total exergy destruction, accounting for 94.97%.

关键词： aromatics separation and upgrading     variant splitting ratios     total exergy destruction     total product unit cost    

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Critical flow-storm approach to total maximum daily load (TMDL) development: an analytical conceptual

Zhang Harry, Yu Shaw

《环境科学与工程前沿（英文）》 2008年 第2卷 第3期   页码 267-273 doi: 10.1007/s11783-008-0058-0

摘要： One of the key challenges in the total maximum daily load (TMDL) development process is how to define the critical condition for a receiving waterbody. The main concern in using a continuous simulation approach is the absence of any guarantee that the most critical condition will be captured during the selected representative hydrologic period, given the scarcity of long-term continuous data. The objectives of this paper are to clearly address the critical condition in the TMDL development process and to compare continuous and event-based approaches in defining critical condition during TMDL development for a waterbody impacted by both point and nonpoint source pollution. A practical, event-based critical flow-storm (CFS) approach was developed to explicitly addresses the critical condition as a combination of a low stream flow and a storm event of a selected magnitude, both having certain frequencies of occurrence. This paper illustrated the CFS concept and provided its theoretical basis using a derived analytical conceptual model. The CFS approach clearly defined a critical condition, obtained reasonable results and could be considered as an alternative method in TMDL development.

关键词： representative hydrologic     occurrence     simulation approach     scarcity     alternative    

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From total quality management to Quality 4.0: A systematic literature review and future research agenda

《工程管理前沿（英文）》 2023年 第10卷 第2期   页码 191-205 doi: 10.1007/s42524-022-0243-z

摘要： Quality 4.0 is an emerging concept that has been increasingly appreciated because of the intensification of competition, continually changing customer requirements and technological evolution. It deals with aligning quality management practices with the emergent capabilities of Industry 4.0 to improve cost, time, and efficiency and increase product quality. This article aims to comprehensively review extant studies related to Quality 4.0 to uncover current research trends, distil key research topics, and identify areas for future research. Thus, 46 journal articles extracted from the Scopus database from 2017 to 2022 were collected and reviewed. A descriptive analysis was first performed according to the year-wise publication, sources of publication, and research methods. Then, the selected articles were analyzed and classified according to four research themes: Quality 4.0 concept, Quality 4.0 implementation, quality management in Quality 4.0, and Quality 4.0 model and application. By extracting the literature review findings, we identify the Quality 4.0 definitions and features, develop the quality curve theory, and highlight future research opportunities. This study supports practitioners, managers, and academicians in effectively recognizing and applying Quality 4.0 to enhance customer satisfaction, achieve innovation enterprise efficiency, and increase organizational competitiveness in the era of Industry 4.0.

关键词： quality management     Quality 4.0     Industry 4.0     literature review     predictive quality    

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A total torque index for dynamic performance evaluation of a radial symmetric six-legged robot

Kejia LI, Xilun DING, Marco CECCARELL

《机械工程前沿（英文）》 2012年 第7卷 第2期   页码 219-230 doi: 10.1007/s11465-012-0320-9

摘要：

This article focuses on the dynamic index and performance of a radial symmetric six-legged robot. At first the structure of the robot is described in brief and its inverse kinematics is presented. Then the dynamic model is formulated as based on the Lagrange equations. A novel index of total torque is proposed by considering the posture of the supporting legs. The new index can be used to optimize the leg’s structure and operation for consuming minimum power and avoiding unstable postures of the robot. A characterization of the proposed six-legged robot is obtained by a parametric analysis of robot performance through simulation using the presented dynamic model. Main influences are outlined as well as the usefulness of the proposed performance index.

关键词： six-legged robots     dynamic modeling     performance index    

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Total phosphorus concentrations in surface water of typical agro- and forest ecosystems in China, 2004

Juan XIE,Xinyu ZHANG,Zhiwei XU,Guofu YUAN,Xinzhai TANG,Xiaomin SUN,D.J. BALLANTINE

《环境科学与工程前沿（英文）》 2014年 第8卷 第4期   页码 561-569 doi: 10.1007/s11783-013-0601-5

摘要： The concentrations of total phosphorus (TP) from 83 surface water sampling sites in 29 of the Chinese Ecosystem Research Network (CERN) monitored ecosystems, representing typical agro- and forest ecosystems, were assessed using monitoring data collected between 2004 and 2010 from still and flowing surface water. Results showed that, TP concentrations were significantly higher in agro-ecosystems than those in forest ecosystems both for still and flowing surface water. For agro-ecosystems, TP concentrations in the southern area were significantly higher than those in the northern and north-western areas for both still and flowing surface water, however no distinct spatial pattern was observed for forest ecosystems. In general, the median values of TP within agro- and forest ecosystems did not exceed the Class V guideline for still (0.2 mg·L ) or flowing (0.4 mg·L ) surface water, however, surface water at some agro-ecosystem sampling sites was frequently polluted by TP. Elevated concentrations were mainly found in still surface water at the Changshu, Fukang, Linze and Naiman monitored ecosystems, where exceedance (>0.2 mg·L ) frequencies varied from 43% to 78%. For flowing water, elevated TP concentrations were found at the Hailun, Changshu and Shapotou monitored ecosystems, where exceedance (>0.4 mg·L ) frequencies varied from 29% to 100%. Irrational fertilization, frequent irrigation and livestock manure input might be the main contributors of high TP concentrations in these areas, and reduced fertilizer applications, improvements in irrigation practices and centralized treatment of animal waste are necessary to control P loss in these TP vulnerable zones.

关键词： Chinese Ecosystem Research Network (CERN)     total phosphorus (TP)     surface water     ecosystem type     spatial variation    

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Standard method design considerations for semi-quantification of total naphthenic acids in oil sands

Kevin A. Kovalchik, Matthew S. MacLennan, Kerry M. Peru, John V. Headley, David D.Y. Chen

《化学科学与工程前沿（英文）》 2017年 第11卷 第3期   页码 497-507 doi: 10.1007/s11705-017-1652-0

摘要： Naphthenic acids are a complex class of thousands of naturally occurring aliphatic and alicyclic carboxylic acids found in oil sands bitumen and in the wastewater generated from bitumen processing. Dozens of analytical methods have been developed for the semi-quantification of total naphthenic acids in water samples. However, different methods can give different results, prompting investigation into the comparability of the many methods. A review of important methodological features for analyzing total naphthenic acids is presented and informs the design of future standard methods for the semi-quantification of total naphthenic acids using mass spectrometry. The design considerations presented are a synthesis of discussions from an Environment and Climate Change Canada (ECCC) led taskforce of 10 laboratory experts from government, industry and academia during April 2016 and subsequent discussions between University of British Columbia and ECCC representatives. Matters considered are: extraction method, solvent, pH, and temperature; analysis instrumentation and resolution; choice of calibration standards; use of surrogate and internal standards; and use of online or offline separation prior to analysis. The design considerations are amenable to both time-of-flight and Orbitrap mass spectrometers.

关键词： total naphthenic acids     environmental samples     oil sands process affected water     polar organics     mass spectrometry    

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EFFECTS OF TRANSPORT STRESS ON THE INTESTINES INVOLVING NEURONAL NITRIC OXIDE SYNTHASE

《农业科学与工程前沿（英文）》   页码 285-295 doi: 10.15302/J-FASE-2022469

摘要：

● Transport stress declined the level of leukocytes including lymphocytes in rat serum.

关键词： intestine     nNOS     nNOS-positive neurons     transport stress    

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Evaluation of groundwater quality in the Xinjiang Plain Area

Jinlong ZHOU, Xinguang DONG, Yiping WANG, Guomin LI, Xiaojing GUO,

《环境科学与工程前沿（英文）》 2010年 第4卷 第2期   页码 183-186 doi: 10.1007/s11783-010-0021-8

摘要： Groundwater is the main source of drinking water for the urban and rural residents in the plain area of the Xinjiang Uygur Autonomous Region, China. The quality of groundwater has a direct relationship with human health. Thus, 386 groundwater samples collected from April to August in 2003 were analyzed. The samples were collected in basic evaluation units which are determined on the basis of watersheds. Total dissolved solids, total hardness, pH value, NH–N, CHOH, Chemiluminescence detection of permanganate index (COD) and intestinal germ group were evaluated according to the guidelines of Groundwater Quality Standard (GB/T14848-93). The quality of the groundwater in each evaluation unit was classified by using the One Veto Method (a unified approach stipulated by the Ministry of Water Resources). The results indicate that the groundwater in the mainstream area of the Tarim Basin and the Yerqiang River Sub-basin belongs to Category V; the groundwater in the Wulungu River Sub-basin, the Kaidu-Kongque River Sub-basin, the Kashgar River Sub-basin, the Cherchen River Sub-basin and the Hotan River Sub-basin belongs to Category IV; the groundwater in the Aibi Lake System belongs to Category II, and the groundwater of other evaluation units belongs to Category III. The causes of water quality formation were concisely analyzed. The results can be useful for the evaluation and management of water resources in the Xinjiang Plain Area.

关键词： groundwater quality     evaluation     one veto method     total dissolved solids (TDS)     pH     total hardness    

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Analysis on annealing-induced stress of blind-via TSV using FEM

Jie SHAO, Tielin SHI, Li DU, Lei SU, Xiangning LU, Guanglan LIAO

《机械工程前沿（英文）》 2018年 第13卷 第3期   页码 401-410 doi: 10.1007/s11465-017-0457-7

摘要：

Copper-filled through silicon via (TSV) is a promising material owing to its application in high-density three-dimensional (3D) packaging. However, in TSV manufacturing, thermo-mechanical stress is induced during the annealing process, often causing reliability issues. In this paper, the finite element method is employed to investigate the impacts of via shape and SiO2 liner uniformity on the thermo-mechanical properties of copper-filled blind-via TSV after annealing. Top interface stress analysis on the TSV structure shows that the curvature of via openings releases stress concentration that leads to ~60 MPa decrease of normal stresses, sxx and syy, in copper and ~70 MPa decrease sxx of in silicon. Meanwhile, the vertical interface analysis shows that annealing-induced stress at the SiO2/Si interface depends heavily on SiO2 uniformity. By increasing the thickness of SiO2 linear, the stress at the vertical interface can be significantly reduced. Thus, process optimization to reduce the annealing-induced stress becomes feasible. The results of this study help us gain a better understanding of the thermo-mechanical behavior of the annealed TSV in 3D packaging.

关键词： through silicon via (TSV)     annealing-induced stress     interface stress     plastic deformation     finite element method    

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Modified pretreatment method for total microbial DNA extraction from contaminated river sediment

Yun FANG,Meiying XU,Xingjuan CHEN,Guoping SUN,Jun GUO,Weimin WU,Xueduan LIU

《环境科学与工程前沿（英文）》 2015年 第9卷 第3期   页码 444-452 doi: 10.1007/s11783-014-0679-4

摘要： Extraction of high-quality microbial DNA from contaminated environmental samples is an essential step in microbial ecological study. Based on previously published methods for soil and sediment samples, a modified pretreatment method was developed for extracting microbial DNA from heavily contaminated river sediment samples via selection of optimal pretreatment parameters (i.e., reagent solution, reaction duration, and temperature). The pretreatment procedure involves washing the river sediment sample for three times with a solution containing 0.1 mol·L ethylene diamine tetraacetic acid (EDTA), 0.1 mol·L Tris (pH 8.0), 1.5 mol·L NaCl, 0.1 mol·L NaH PO , and Na HPO at 65°C with 180 r·min for 15 min to remove humic materials and heavy metals prior to the employment of standard DNA extraction procedures. We compared the results of standard procedure DNA extraction following pretreatment, without pretreatment, and with using a commercial PowerSoil DNA Isolation Kit. The results indicated that the pretreatment significantly improved the DNA quality based on DNA yield, DNA fragment length, and determination of prokaryotic diversity. Prokaryotic diversity exhibited in the DNA with the pretreatment was also considerably higher than that extracted with the PowerSoil DNA Isolation Kit only. The pretreatment method worked well even with a small amount of sediment sample (0.25 g or even lower). The method provides a novel, simple, cost-effective tool for DNA extraction for microbial community analysis in environmental monitoring and remediation processes.

关键词： river sediment     DNA extraction     contaminant     pretreatment     microbial community    

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标题 作者 时间 类型 操作

Total stress rapid drawdown analysis of the Pilarcitos Dam failure using the finite element method

Daniel R. VANDENBERGE

期刊论文

two saturated natural soils and their saturated remoulded soils under three consolidated undrained stress

Mingjing JIANG, Haijun HU, Jianbing PENG, Serge LEROUEIL

期刊论文

Advantages of intermittently aerated SBR over conventional SBR on nitrogen removal for the treatment of digested piggery wastewater

Xiaoyan Song, Rui Liu, Lujun Chen, Baogang Dong, Tomoki Kawagishi

期刊论文

Simultaneous removal of total oxidizable carbon, phosphate and various metallic ions from HO solution

期刊论文

Implementation of total Lagrangian formulation for the elasto-plastic analysis of plane steel frames

Bing XIA, Yuching WU, Zhanfei HUANG

期刊论文

Exergy and exergoeconomic analyses for integration of aromatics separation with aromatics upgrading

期刊论文

Critical flow-storm approach to total maximum daily load (TMDL) development: an analytical conceptual

Zhang Harry, Yu Shaw

期刊论文

From total quality management to Quality 4.0: A systematic literature review and future research agenda

期刊论文

A total torque index for dynamic performance evaluation of a radial symmetric six-legged robot

Kejia LI, Xilun DING, Marco CECCARELL

期刊论文

Total phosphorus concentrations in surface water of typical agro- and forest ecosystems in China, 2004

Juan XIE,Xinyu ZHANG,Zhiwei XU,Guofu YUAN,Xinzhai TANG,Xiaomin SUN,D.J. BALLANTINE

期刊论文

Standard method design considerations for semi-quantification of total naphthenic acids in oil sands

Kevin A. Kovalchik, Matthew S. MacLennan, Kerry M. Peru, John V. Headley, David D.Y. Chen

期刊论文

EFFECTS OF TRANSPORT STRESS ON THE INTESTINES INVOLVING NEURONAL NITRIC OXIDE SYNTHASE

期刊论文

Evaluation of groundwater quality in the Xinjiang Plain Area

Jinlong ZHOU, Xinguang DONG, Yiping WANG, Guomin LI, Xiaojing GUO,

期刊论文

Analysis on annealing-induced stress of blind-via TSV using FEM

Jie SHAO, Tielin SHI, Li DU, Lei SU, Xiangning LU, Guanglan LIAO

期刊论文

Modified pretreatment method for total microbial DNA extraction from contaminated river sediment

Yun FANG,Meiying XU,Xingjuan CHEN,Guoping SUN,Jun GUO,Weimin WU,Xueduan LIU

期刊论文