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Investigating Peak stresses in fitting and repair patches of buried polyethylene gas pipes

Frontiers of Structural and Civil Engineering 2020年第1期14卷 147-168页

作者： Reza KHADEMI ZAHEDI Pouyan ALIMOURI Hooman KHADEMI ZAHEDI Mohammad SHISHESAZ Institute of Structural Mechanics Bauhaus-Universitat WeimarMariensrtaβe 15Weimar 99423Germany Mechanical Engineering Department Shahid Chamran University of AhvazAhvazIran Mechanical Engineering Department Islamic Azad UniversityNorth Tehran BranchIran

Nowadays,polyethylene composes a large number of natural gas distribution pipelines installed under the ground.The focus of the present contribution is two fold.One of the objectives is to investigate the applicability of polyethylene fittings in joining polyethylene gas pipes which are electrofused onto the pipe ends and buried under the ground,by estimating stress distribution using finite element method.The second objective is to study the effectiveness of polyethylene repair patches which are used to mend the defected pipelines by performing a finite element analysis to calculate Peak stress values.Buried polyethylene pipelines in the natural gas industry,can be imposed by sever loadings including the soil-structure interaction,traffic load,soil’s column weight,internal pressure,and thermal loads resulting from daily and/or seasonal temperature changes.Additionally,due to the application of pipe joints,and repair patches local stresses superimposed on the aforementioned loading effects.The pipe is assumed to be made of PE80 resin and its jointing socket,and the repair patch is PE100 material.The computational analysis of stresses and the computer simulations are performed using ANSYS commercial software.According to the results,the Peak stress values take place in the middle of the fitting and at its internal surface.The maximum stress values in fitting and pipe are below the allowable stresses which shows the proper use of introduced fitting is applicable even in hot climate areas of Ahvaz,Iran.Although the buried pipe is imposed to the maximum values of stresses,the PE100 socket is more sensitive to a temperature drop.Furthermore,all four studied patch arrangements show significant reinforcing effects on the defected section of the buried PE gas pipe to transfer applied loads.Meanwhile,the defected buried medium density polyethylene gas pipe and its saddle fused patch can resist the imposed mechanical and thermal loads of 22℃ temperature increase.Moreover,increasing the saddle fusion patch length to 12 inch

关键词： Ansys software polyethylene buried pipelines polyethylene joints polyethylene patches Peak von Mises stress soil-pipe interaction temperature variation

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Spectrum-effect relationship between HPLC fingerprints and bioactive components of Radix Hedysari on increasing the Peak bone mass of rat

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Journal of Pharmaceutical Analysis 2019年第4期9卷 266-273页

作者： Xin-Yue Chen San-Hu Gou Zhi-Qiang Shi Zhi-Yuan Xue Shi-Lan Feng School of Pharmacy Lanzhou University

The traditional Chinese medicine of Radix Hedysari plays an important role in invigorating gas for ascending, benefiting blood for promoting production of fluid, and promoting circulation for removing obstruction in collaterals, which is consistent with the principle of treatment for osteoporosis. This study is designed to investigate the bioactive components on increasing Peak bone mass (PBM) by exploring the spectrum-effect relationship between chromatography fingerprints and effect. Multiple indicators are selected to evaluate the pharmacological activity. In fingerprints, 21 common Peaks are obtained, five of which are identified. Furthermore, gray relational analysis (GRA) is a quantitative method of gray system theory and is used to describe the correlation degree of common Peaks and pharmacological activities with relational value. 21 components are then divided into three different regions, of which ononin and calycosin play an extremely significant role in increasing PBM. In addition, factor analysis and hierarchical cluster analysis (HCA) are used to screen the optimal producing area for Radix Hedysari. This provides a comprehensive and efficient method to improve the quality evaluation of Radix Hedysari, confirming the bioactive components for PBM-enhancement and further develop its medicinal value.

关键词： Factor analysis Gray relational analysis Hierarchical cluster analysis Peak bone mass Radix Hedysari Spectrum-effect relationship

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Practical assessment of rock damage due to blasting

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International Journal of Mining Science and Technology 2019年第3期29卷 379-385页

作者： Jhon Silva Tristan Worsey Braden Lusk Department of Mining Engineering University of KentuckyLexingtonKY 40508USA Department of Mining and Nuclear Engineering Missouri University of Science and TechnologyRollaMO 65409USA

Blasting is the most cost effective methodology to break rock for mining or civil engineering applications.A good production blast will break only the rock that is needed to be removed,leaving the host rock with minimal damage.The control of rock damage due to blasting is very important when it comes to mine or construction design,safety,and cost.Damage to the host rock due to a production blast could result in failures,overbreak and unstable ground.Knowing how far the fractures generated by a production blast will go into the host rock is a valuable tool for engineers to design a safe highwall while keeping the actual excavation close to the design.Currently,there are several methods available to predict damage due to blasting.The accuracy of many of these methods is questionable,and in most cases,the methodologies over predict the results.This often leads to inefficient mines and poor construction works.When the current methodologies are reviewed,each one presents sound approaches,but in many cases they also lack consideration of other variables that,according to the authors,need to be included when predicting blast damage.This paper presents a practical methodology to assess the rock damage from blasting by combining other methodologies.The proposed method allows consideration of more variables when compared to available methods,resulting in a more accurate rock damage assessment.The method uses the estimation of the generated levels of Peak particle velocity with the distance from a production blast presented by Persson and Holmberg,the Peak particle velocity damage ranges proposed by Forsyth and the relationship between the static compressive strength and dynamic compressive strength of rocks from Liu.The new methodology was validated using the data published in a large-scale study performed in granite by Siskind.

关键词： Blasting Fracture Fracture extension Peak particle velocity

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Peak关系训练系统：孤独症语言障碍康复的新方法

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心理科学进展 2019年第11期27卷 1896-1905页

作者：白晓宇 Tawanda S.Mutusva 祝卓宏中国科学院心理研究所心理健康重点实验室北京100101 中国科学院心理研究所脑与认知科学国家重点实验室北京100101 中国科学院大学心理学系北京100049

Peak (Promoting the Emergence of Advanced Knowledge,促进高阶知识涌现)关系训练系统是全球首个同时整合了斯金纳的《言语行为》和后斯金纳主义的“关系框架理论”,促进孤独症谱系障碍(Autism spectrumdisorders, ASD)患者的语言、... 详细信息

Peak (Promoting the Emergence of Advanced Knowledge,促进高阶知识涌现)关系训练系统是全球首个同时整合了斯金纳的《言语行为》和后斯金纳主义的“关系框架理论”,促进孤独症谱系障碍(Autism spectrumdisorders, ASD)患者的语言、学习、社交等核心技能发展的语言行为评估训练系统。截至2018 年底, Peak 关系训练系统由以下4 个模块组成:直接训练模块、泛化模块、等价关系模块、功能转化模块。每一模块依据难易程度分别设置了184 个目标能力的评估方法及训练课程。已发表的多项实证研究表明, Peak 关系训练系统打破了《语言行为里程碑评估及安置程序》(Verbal Behavior Milestones and Placement Program, VB-MAPP)对ASD 患者进行里程碑评估时出现的“天花板效应”,有望比VB-MAPP 提供更全面、高阶的语言行为评估体系。此外, Peak 关系训练系统表现出的评估工具的信效度良好、多项效果研究显著、实践中易操作等特性,使其不仅适用于专业人员教学,未来在ASD 患者家庭干预模式中也有潜在的应用价值。

关键词：孤独症谱系障碍关系框架理论 Peak 言语行为 VB-MAPP

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A numerical modelling approach to assess the behaviour of underground cavern subjected to blast loads

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International Journal of Mining Science and Technology 2018年第6期28卷 975-983页

作者： Saikat Kuili Vedala Rama Sastry Department of Civil Engineering National Institute of Technology Karnataka Department of Mining Engineering National Institute of Technology Karnataka

The paper gives an insight into the behaviour of large underground caverns which are subjected to blast loads. Caverns are generally constructed in hard rock formation which compels us to use blasting methods for the excavation works. Comparative study was done between models with intact rock mass and discontinuities to assess the stability of cavern as a result of blast loads. Numerical modelling was performed with 3 dimensional distinct element code(3 DEC) to analyse the performance of cavern walls in terms of displacement and to compute Peak particle velocities(PPV) both around the cavern periphery and at surface of models. Results showed that the velocity wave with higher frequency exhibited large displacements around the periphery of cavern. Computation of PPV showed that model with horizontal joint sets showed lower PPV in comparison to model with intact rock mass. PPV values were also analysed on the surface for model consisting vertical joints spaced at 4 m intervals. Comparative study of PPV on surface vertically above the blast location between models with horizontal joints spaced at 4 m and vertical joints at 4 m intervals were conducted. Results depicted higher magnitudes of PPV for model with vertical joints in comparison to model with horizontal joints.

关键词： Large underground caverns Hard rock formation Numerical modelling 3 dimenssional distinct element code Peak particle velocities

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Monitoring of brown stink bug (Hemiptera: Pentatomidae) population dynamics in corn to predict its abundanee using weather data

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Insect Science 2019年第3期26卷 536-544页

作者： Xinzhi Ni Ted E. Cottrell G. David Buntin Xianchun Li Wei Wang Hong Zhuang USDA-ARS Crop Genetics and Breeding Research Unit Tifton Georgia USA USDA-ARS Southeastern Fruit and Tree Nut Research Laboratory Byron Georgia USA Department of Entomology University of Georgia Griffin Georgia USA Department of Entomology University of Arizona Tucson Arizona USA College of Engineering China Agricultural University Beijing China USDA-ARS Quality and Safety Assessment Research Unit Athens Georgia USA

The brown stink bug (BSB), Euschistus servus (Say)(Hemiptera: Pentatomidae), is a serious economic pest of corn production in the southeastern United States. The BSB population dynamics was mon itored for 17 weeks from tasseling to preharvest of corn plants (i.e., late May to mid-September) using pheromone traps in three corn fields from 2005 to 2009. The trap data showed two Peaks in early June and mid-August, respectively. The relationship between trap catch and pregrowing season weather data was examined using correlation and stepwise multiple factor regression analyses. Weather indices used for the analyses were accumulated growing degree day (AGDD), number of days with minimum temperature below 0℃(Subz), accumulated daily maximum (AMaxT) and minimum temperatures (AMinT) and rainfall (ARain). The weather indices were calculated with lower (10℃) and upper (35℃) as biological thresholds. The parameters used in regression analysis were seasonal abundance (or overall mean of BSB adult catch)(BSBm), number of BSB adults caught at a Peak (PeakBSB), and Peak week (Peakwk). The BSBm was negatively related to high temperature (AmaxT or AGDD) consistently, whereas IstPeakBSB was positively correlated to both ARain and Subz, irrespective of weather data durations (the first 4, 4.5, and 5 months). In contrast, the 7-month weather data (AGDD7) were negatively correlated to the BSBm only, but not correlated to the second PeakBSB. The 5-year monitoring study demonstrated that weather data can be used to predict the BSB abundance at its first Peak in tasseling corn fields in the southeastern U.S. states.

关键词： Euschistus servus first trap catch Peak pheromone trap catch population dynamics stepwise regression modeling weekly mean

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Silicon saturation coefficient changes in hydrogarnets during the Bayer process with lime addition

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Chinese Journal of Chemical Engineering 2019年第8期27卷 1965-1972页

作者： Guozhi Lü Ting’an Zhang Xiaofeng Zhu Chaozhen Zheng Yanxiu Wang Weiguang Zhang Zimu Zhang Key Laboratory of Ecological Metallurgy of Multi-metal Intergrown Ores of Ministry of Education School of Metallurgy Northeastern University

The relationship between the silicon saturation coefficient of hydrogarnets and Bayer reaction parameters was studied. The Peak position, crystal plane spacing, and cell edge length of typical hydrogarnet patterns were calculated to find the key factors influencing the relationship. The results showed that the crystal face(420) is the optimal garnet growth direction during hydration and crystal growth along the faces(521) and(611) were not affected significantly by the varying experimental conditions. The reaction temperature significantly influenced the silicon saturation coefficient of hydrogarnets. The silicon saturation coefficient of hydrogarnets increased from 0.2 to about 1.0 in the temperature range of 30–270 °C and a rapid expansion process was observed in the temperature range of 120–150 °C. Moreover, the reaction time, alumina concentration, and C/S were shown to be less important factors. Averaging the results obtained by the 3 methods was shown suitable for calculating the SiO2 saturation coefficient of hydrogarnets. The calculated results of the Al2O3 and SiO2 contents matched the actual ones. However, the actual SiO2 content was about10 % less than the calculated one for SiO2 saturation coefficients higher than 1.

关键词： Hydrogarnet Saturation coefficient Peak position Crystal plane spacing Cell edge length

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China's pre-2020 CO2 emission reduction potential and its influence

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Frontiers in Energy 2019年第3期13卷 571-578页

作者： Hailin WANG Jiankun HE Institute of Energy Environment and Economy Institute of Climate Change and Sustainable DevelopmentTsinghua UniversityBeijing 100084China Institute of Energy Environment and Economy Modem Management Research CenterInstitute of Climate Change and Sustainable DevelopmentTsinghua UniversityBeijing 100084China

China achieved the reduction of CO2 intensity of GDP by 45% compared with 2005 at the end of 2017, realizing the commitment at 2009 Copenhagen Conference on emissions reduction 3 years ahead of time. In future implementation of the "13th Five-Year Plan (FYP)," with the decline of economic growth rate, decrease of energy consumption elasticity and optimization of energy structure, the CO2 intensity of GDP will still have the potential for decreasing before 2020. By applying KAYA Formula decomposition, this paper makes the historical statistics of the GDP energy intensity decrease and CO2 intensity of energy consumption since 2005, and simulates the decrease of CO2 intensity of GDP in 2020 and its influences on achieving National Determined Contribution (NDC) target in 2030 with scenario analysis. The results show that China's CO2 intensity of GDP in 2020 is expected to fall by 52.9%-54.4% than the 2005 level, and will be 22.9%-25.4% lower than 2015. Therefore, it is likely to overfulfill the decrease of CO2 intensity of GDP by 18% proposed in the 13th FYP period. Furthermore, the emission reduction potentiality before 2020 will be conducive to the earlier realization of NDC objectives in 2030. China's CO2 intensity of GDP in 2030 will fall by over 70% than that in 2005, and CO2 emissions Peak will appear before 2030 as early as possible. To accelerate the transition to a low-carbon economy, China needs to make better use of the carbon market, and guide the whole society with carbon price to reduce emissions effectively. At the same time, China should also study the synergy of policy package so as to achieve the target of emission reduction.

关键词： China's National Determined Contribution emission reduction potential scenario analysis CO2 emissions Peak

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An Empirical Study on China＇s Energy Supply-and-Demand Model Considering Carbon Emission Peak Constraints in 2030

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Engineering 2017年第4期3卷 512-517页

作者： Jinhang Chen China Datang Corporation Beijing 100033 China

China’s energy supply-and-demand model and two related carbon emission scenarios, including a planned Peak scenario and an advanced Peak scenario, are designed taking into consideration China’s economic development, technological progress, policies, resources, environmental capacity, and other factors. The analysis of the defined scenarios provides the following conclusions: Primary energy and power demand will continue to grow leading up to 2030, and the growth rate of power demand will be much higher than that of primary energy demand. Moreover, low carbonization will be a basic feature of energy supply-and-demand structural changes, and non-fossil energy will replace oil as the second largest energy source. Finally, energy-related carbon emissions could Peak in 2025 through the application of more efficient energy consumption patterns and more low-carbon energy supply modes. The push toward decarbonization of the power industry is essential for reducing the Peak value of carbon emissions.

关键词： Carbon emission Peak Energy supply and demand Model Scenario

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Different Flooding Behaviors Due to Varied Urbanization Levels within River Basin: A Case Study from the Xiang River Basin,China

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International Journal of Disaster Risk Science 2019年第1期10卷 89-102页

作者： Juan Du Linlin Cheng Qiang Zhang Yumeng Yang Wei Xu Key Laboratory of Environmental Change and Natural Disaster Ministry of Education Beijing Normal University State Key Laboratory of Earth Surface Processes and Resource Ecology Beijing Normal University State Key Laboratory of Remote Sensing Science Beijing Normal University Academy of Disaster Reduction and Emergency Management Faculty of Geographical Science Beijing Normal University

Booming urbanization due to a fast-growing population results in more impervious areas, less infiltration,and hence greater flood Peak and runoff. Clear understanding of flood responses in regions with different levels and expansions of urbanization is of great importance for regional urban planning. In this study, comparison of flooding responses to urbanization processes in terms of flood Peak and runoff volume in the upper, middle,and lower Xiang River Basin(XRB), China, was carried out using the Hydrologic Engineering Center-Hydrologic Modeling System(HEC-HMS) model. From 2005 to 2015, urbanization level and intensity were higher in the lower XRB compared to the upper and middle XRB, and the overall expansion rate of urban areas was 112.8%.Modeling results by the HEC-HMS model indicate elevated flood Peak discharges and volumes due to fast urbanization in the XRB from the 1980 s to 2015. This rapid increase is particularly the case in the lower XRB. The study also revealed different hydrological responses of flood regimes—urbanization tends to have larger impacts on Peak flood flow rather than on flood volume in the lowerXRB, which further corroborated urbanization-induced intensifying flood processes in terms of Peak flood flow.Urbanization has increasing impacts on flood volume from the upper to the lower XRB, which can be attributed to accumulated runoff down the river system. This study provides a reference for basin-wide land use and urban planning as well as flood hazard mitigation.

关键词： Flood volume Flooding processes HECHMS Peak flood flow Urbanization level Xiang River Basin China

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