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Analysis of Pollutant load carrying capacity of the River Tapi Using QUAL2Kw for Surat City

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Journal of Environmental Protection 2023年第2期14卷 96-107页

作者： Hiralkumari B. Patel Namrata D. Jariwala Department of Civil Engineering Sardar Vallabhbhai National Institute of Technology Surat India

River Tapi is the prime water body for Surat city, Gujarat, India. On a long stretch of 22.39 km in Surat city (Kamrej to Causeway) of the Tapi river, there are many identified and non-identified discharge points available. Excessive discharge from these points restricts the efficiency of the self-purification process which ultimately degrades the river water quality. In this paper, an attempt has been made to estimate the pollutant load-carrying capacity at different segments of the river Tapi using the QUAL2Kw tool. The study has been undertaken with different scenarios: First, the QUAL2Kw model was trained with available river water quality and hydraulic data of the Tapi river in which the complete river segment was divided into 21 reaches. The model was calibrated and validated with the actual concentrations of the pollutants entering. In the second phase, all the point source, non-point source, and headwater characteristics were considered and the pollutant load-carrying capacity of the river in terms of BOD, ISS, and N-nitrate was found. In the third phase, all the sources of pollutants entering the river have been removed and only headwater characteristics were considered for the study. The results indicate that reach no. 21 (21.23ºN, 72.82ºE) has the maximum load-carrying capacity of Biochemical Oxygen Demand (BOD) up to 2057.7 kg/day, Inorganic Suspended Solids (ISS) up to 85633.8 kg/day, and Nitrate (NO3) up to 31688.8 kg/day. However, reach no. 4 has the minimum load carrying capacity of BOD up to 1088.1 kg/day, reach 8 carries a minimum of ISS 205341.6 kg/day and NO3 10215.57 kg/day.

关键词： load carrying capacity River Water Quality QUAL2Kw Tapi River

NEW APPROACHES FOR COMPUTING DYNAMIC load-carrying capacity OF MULTIPLE COOPERATING ROBOTIC MANIPULATORS

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维普期刊数据库

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Chinese Journal of Mechanical Engineering 1998年第2期11卷 67-72页

作者： Yang Yulin Lu Ling Zhao Yongsheng Zhou Yulin Yanshan University Yanshan Univ China

A novel unified method for computing the dynamic load carrying capacity(DLCC) of multiple cooperating robotic manipulators is *** this method,the kinematic constraints and the governing dynamic equations of the multiple robot system are formulated in the joint space by using the method of transference of dependence from one set of generalized coordinates to another,and the virtual work principle,which includes the readily available dynamics and joint torques of individual manipulators,and the dynamic of *** on this dynamic model,the upper limit of the DLCC at any points on a given trajectory is obtained by solving a small size linear programming *** method is conceptually straightforward,and it is applicable also to the cases of multi fingered robot hands and multi legged walking machines.

关键词： Robotic manipulators Cooperating Dynamics load carrying capacity

Numerical Analysis of the Hydrodynamic Lubrication of Micro-grooved Friction Pair

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Journal of Donghua University(English Edition) 2016年第1期33卷 159-166页

作者：丁行武陈国栋卜继玲 Zhuzhou Times New Material Technology Co . Ltd.

A growing interest is given to the hydrodynamic lubricated friction pair with surface textured. Because of its relatively simple processing methods and low manufacturing costs,micro-groove has become the most valuable form of surface texture,and definitely has broad application prospects in mechanical engineering. Based on numerical simulation,the present study aims to examine the effects of surface forms and cross-section types of micro-groove on the hydrodynamic lubrication performance,and to find out the optimal structural parameter for designing logical micro-grooves. Different surface form and cross-section types are designed to maximize the texture hydrodynamic effect. The average pressure of such microgrooved surface is evaluated in detail,and the variation trends with changes of the length of micro-groove,lp,or the depth,hp,are discussed. The theoretical results show that micro-grooves with rational design contribute to the improvement of hydrodynamic lubrication performance of friction pair largely. For a specific micro-grooved friction pair,the optimal surface form and crosssection type make the lubrication performance best.

关键词： surface texture hydrodynamic lubrication finite difference method micro-groove load carrying capacity

Flexural behaviors of steel reinforced ECC/concrete composite beams

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Journal of Southeast University(English Edition) 2012年第2期28卷 195-202页

作者：董洛廷潘金龙袁方梁坚凝东南大学混凝土及预应力混凝土教育部重点实验室南京210096 香港科技大学土木及环境工程学系中国香港999077

An engineered cementitious composite （ECC） is introduced to partially substitute concrete in the tension zone of a reinforced concrete beam to form an ECC/reinforced concrete （RC） composite beam, which can increase the ductility and crack resisting ability of the beam. Based on the assumption of the plane remaining plane and the simplified constitutive models of materials, the stress and strain distributions along the depth of the composite beam in different loading stages are comprehensively investigated to obtain calculation methods of the load-carrying capacities for different stages. Also, a simplified formula for the ultimate load carrying capacity is proposed according to the Chinese code for the design of concrete structures. The relationship between the moment and curvature for the composite beam is also proposed together with a simplified calculation method for ductility of the ECC/RC composite beam. Finally, the calculation method is demonstrated with the test results of a composite beam. Comparison results show that the calculation results have good consistency with the test results, proving that the proposed calculation methods are reliable with a certain theoretical significance and reference value.

关键词： engineered cementitious composites (ECC) reinforced concrete composite beam flexural properties load carrying capacity

Finite element failure analysis of continuous prestressed concrete box girders

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Journal of Southeast University(English Edition) 2009年第2期25卷 236-240页

作者：张峰李术才李树忱叶见曙雷笑山东大学土建与水利学院济南250061 东南大学交通学院南京210096

In order to analyze the load carrying capacity of prestressed concrete box girders, failure behaviors of in-situ deteriorated continuous prestressed concrete box girders under loading are experimentally observed and a finite failure analysis method for predicting behaviors of box girders is developed. A degenerated solid shell element is used to simulate box girders and material nonlinearity is considered. Since pre-stressed concrete box girders usually have a large number of curve prestressed tendons, a type of combined element is presented to simulate the prestressed tendons of box girders, and then the number of elements can be significantly reduced. The analytical results are compared with full-scale failure test results. The comparison shows that the presented method can be effectively applied to the failure analysis of in-situ continuous prestressed concrete box girders, and it also shows that the studied old bridge still has enough load carrying capacity.

关键词： full-scale failure test prestressed concrete box girder finite element analysis combined element prestressed tendon load carrying capacity