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Critical movement of large rocks in currents and waves

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International Journal of Sediment Research 2019年第4期34卷 387-398页

作者： L.C.van Rijn LVR-Sediment consultancy

Cobbles, boulders, and rocks often are used in a bed protection layer near a structure to protect the underlying sand bed against erosion by combined current and waves. The design of a bed protection layer consisting of loose rocks(rubble mound) requires knowledge of the stability and movement(as bed load) of very coarse materials. If some movement(or damage) is acceptable, the rock diameter can be designed to be smaller. This paper addresses the stability and movement of very coarse materials(cobbles, boulders, and rocks) based on the concept of the critical Shields mobility number. It is shown that the bed load transport of large cobbles, boulders, and rocks can be described by the equations of Meyer-Peter and Mueller(MPM) and Cheng. Both are valid for relatively small Shields mobility *** and general equations for the design of a bed protection layer(including some permissible damage)in conditions with a current with or without waves are proposed based on the Shields mobility parameter and the bed load transport equation of Cheng. Laboratory and field data of critical velocities for pebbles, cobbles, boulders, and rocks have been analyzed and compared to the computed results of the proposed equations. Practical applications are given to demonstrate the general applicability of the proposed equations.

关键词： Rock stability Bed protection Critical movement Bed load transport Rocks

How will biomining be applied in future?

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中国有色金属学会会刊：英文版 2008年第6期18卷 1302-1310页

作者： C.L.BRIERLEY Brierley consultancy LLC P.O.Box 630012Highlands Ranch

这篇论文在全世界考察商业 biomining 操作的当前的地位，识别作为一种处理技术驾驶 biomining 的选择的因素，描述挑战到利用这些革新，并且与 biomining 的未来的讨论得出结论。Biomining 商业地用设计垃圾场，堆和搅动的坦克被使用... 详细信息

这篇论文在全世界考察商业 biomining 操作的当前的地位，识别作为一种处理技术驾驶 biomining 的选择的因素，描述挑战到利用这些革新，并且与 biomining 的未来的讨论得出结论。Biomining 商业地用设计垃圾场，堆和搅动的坦克被使用。克服阴沉的费用的技术挑战，处理在矿的低档，低质量、复杂的矿石和利用存在大写的投资要求微生物引起的活动和创新工程的更好的理解。克服 biomining 广告挑战必要改进采矿 company/biomining 改革者合作和知识产权控制。

关键词：生物采矿生物浸取应用技术研究

Investigation of MS and Anti-segregation Process HSS Flat Broaching Tools

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厦门大学学报（自然科学版） 2002年第S1期41卷 106-107页

作者： Mohammed Sarwar Industrial Research & consultancy Centre

An investigation has been carried out to compare th e cutting performance and tool life evaluation of high speed steel broach samp les. The comparison has been done between conventional M2 and Anti-Segregation Process (ASP) ASP53 and ASP30 high speed steel broach samples. The ASP53 was a development material. The cutting performance was evaluated by measuring the c utting forces and calculating the specific cutting energy, an indicator of cutti ng performance. As the roughness of the machined surface is an important criter ion in the evaluation of performance of a tool, the surface roughness of the workpiece was studied as a function of undeformed chip thickness. The workpiec e material was 150M36 alloy steel used in manufacture of automobile engines. Th e performance tests were conducted at two cutting speeds, which were 0 7 m/min and 10.5 m/min respectively. This allowed a better understanding of the effect of cutting speed on tool performance. The wear tests were performed at a cuttin g speed on 10.5 m/min. The cutting edges of ASP broach samples were finer compared to that of M2. Ther e was no practical difference in the cutting forces and the specific cutting ene rgy while cutting with MS, ASP30 and ASP53 broach samples. The ASP30 and ASP53 tools have a better surface roughness on the machined surface than that of M2 at both cutting speeds. The ASP30 gave 2.25 times the life and an improved surfac e finish compared to M2 steel. The ASP53 gave 1.3 times the life of M2 steel. These results should prove useful to the tool designer and manufacturing enginee r.

关键词： Investigation of MS and Anti-segregation Process HSS Flat Broaching Tools MS

Integrated “Generate, Make, and Test” for Formulated Products using Knowledge Graphs

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Data Intelligence 2021年第3期3卷 340-375页

作者： Sagar Sunkle Deepak Jain Krati Saxena Ashwini Patil Tushita Singh Beena Rai Vinay Kulkarni Tata consultancy Services Research Pune MaharashtraIndia411013

In the multi-billion dollar formulated product industry, state of the art continues to rely heavily on experts during the "generate, make and test" steps of formulation design. We propose automation aids to each step with a knowledge graph of relevant information as the central artifact. The generate step usually focuses on coming up with new recipes for intended formulation. We propose to aid the experts who generally carry out this step manually by providing a recommendation system and a templating system on top of the knowledge graph. Using the former, the expert can create a recipe from scratch using historical formulations and related data. With the latter, the expert starts with a recipe template created by our system and substitutes the requisite constituents to form a recipe. In the current state of practice, the three steps mentioned above operate in a fragmented manner wherein observations from one step do not aid other steps in a streamlined manner. Instead of manually operated labs for the make and test steps, we assume automated or robotic labs and in-silico testing, respectively. Using two formulations, namely face cream and an exterior coating, we show how the knowledge graph may help integrate and streamline the communication between the generate, the make, and the test steps. Our initial exploration shows considerable promise.

关键词： Formulated product design Formulation recommendation Formulation template Robotic labs In-silico testing Integrated generate-make-test

Representation of classifier distributions in terms of hypergeometric functions

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China Particuology 2007年第4期5卷 274-283页

作者： B.Venkoba Rao Engineering and Industrial Services Tata Consultancy Services Ltd.1 Mangaldas RoadPune 411001India

This paper derives alternative analytical expressions for classifier product distributions in terms of Gauss hypergeometric function, 2F1, by considering feed distribution defined in terms of Gates-Gaudin-Schumann function and efficiency curve defined in terms of a logistic function. It is shown that classifier distributions under dispersed conditions of classification pivot at a common size and the distributions are difference similar. The paper also addresses an inverse problem of classifier distributions wherein the feed distribution and efficiency curve are identified from the measured product distributions without needing to know the solid flow split of particles to any of the product streams.

关键词： Classifier Efficiency curve Inverse problem

Extraction of tectonic imprints using geospatial techniques:Evidence from Mandakini River basin,Uttarakhand,India

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Journal of Mountain Science 2024年第11期21卷 3720-3738页

作者： Atul Kumar PATIDAR Girish Ch.KOTHYARI Manmohan KAUSHIK Sushil KHANDURI Department of Petroleum Engineering and Earth Sciences UPESDehradun 248007India KainGeotech consultancy Dehradun 248007India

The existing literature discussed only the aerial aspect and provided a brief description of tectonic-geomorphic correlation with field *** present study we applied power law equations to estimate basin asymmetry factor(AF),Transverse topographic asymmetric factor(T),Hypsometric Integral(HI),longitudinal profile,stream length gradient index(SL),steepness index(Ksn),Chi(χ),and knick point(Kp)analysis to examine the response of tectono-climatic fluctuations in the Mandakini River basin,central Uttarakhand *** decouple the causative tectono-climatic factors,we employed geospatial and Stream Power Incision Modeling(SPIM)*** is a globally accepted tool to predict an equilibrium state between fluvial erosion rates and the escalating function of stream *** is actively applied in modeling the transformation of river systems especially in rugged topographic *** present study covers SPIM-based morphometric assessment of the tectonically sensitive Mandakini River basin between Ramgarh Thrust(RT)and Vaikrita Thrust(VT)in the central region of Uttarakhand *** the upper reaches of the basin,U-shaped glaciated valleys dominate the landscape,while a rolling topography and deeply incised narrow valleys are depicted towards the ***,to understand the response of active tectonic over geomorphology,the drainage basin has been divided into two separate zones from the confluence point near the Rampur *** modeling outcomes indicate that the Mandakini drainage basin is in a disequilibrium state where channels are actively incising to ***,AF of 32 and 70 indicate leftward tilting in the upper reaches and rightward tilting in the lower reaches of the basin,*** HI value of 0.38 indicates a stage of maturity,characterized by a concave shape *** on the analysis it may be concluded that the fragile lithology and tectono-climatic fluctuations are dominantly controlling the topography and valle

关键词： Stream Power Incision Model(SPIM) Transverse Topographic Asymmetry Factor(T) Knick points Hypsometric curve Mandakini River Garhwal Himalaya

Flowing to the East-- Small Hydro in Developing Countries

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Small Hydro Power News 2006年第1期23卷 11-15页

作者： Simon Taylor Drona Upadhyay Maria Laguna engineering consultancy ITpower Project Man-ager at ESHA

While the growth of small hydro has slowed in Europe, things look very different in Asia. The region accounts for two-thirds of the world＇s hydro capacity, and far from slowing down, it is enjoying robust growth. Sim... 详细信息

关键词：发展中国家小水电可持续发展能源利用

Reconciliation of size-density bivariate distributions over a separating node

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Particuology 2008年第3期6卷 167-175页

作者： Bidarahalli Venkoba Rao Vivek Ganvir Sirigeri Jois Gopalakrishna Engineering and Industrial Services Tata Consultancy Services Limited 1Mangaldas RoadPune 411001India Tata Research Development and Design Centre Tata Consultancy Services Limited 54BHadapsar Industrial EstatePune 411013India Department of Mineral Processing Post Graduate CenterSandurKarnataka 583119India

Data reconciliation considers the restoration of mass balance among the noise prone measured data by way of component adjustments for the various particle size or particle density classes or assays over the separating node. In this paper, the method of Lagrange multipliers has been extended to balance bivariate feed and product size-density distributions of coal particles split from a settling column. The settling suspension in the column was split into two product fractions at 40% height from the bottom after a minute settling of homogenized suspension at start. Reconciliation of data assists to estimate solid flow split of particles to the settled stream as well as helps to calculate the profiles of partition curves of the marginal particle size or particle density distributions. In general, Lagrange multiplier method with uniform weighting of its components may not guarantee a smooth partition surface and thus the reconciled data needs further refinement to establish the nature of the surface. In order to overcome this difficulty, a simple alternative method of reconciling bivariate size-density data using partition surface concept is explored in this paper.

关键词： Data reconciliation Size-density partition surface Settling test

Use of incipient motion data for backward erosion piping models

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International Journal of Sediment Research 2019年第5期34卷 401-408页

作者： Vera M.van Beek Bryant A.Robbins Gijs J.C.M.Hoffmans Adam Bezuijen Leo C.van Rijn Deltares U.S.Army Engineer Research and Development Center Ghent University Leovanrijn-Sediment-consultancy

Backward erosion piping involves the gradual removal of granular material under the action of water flow from the foundation of a dam or levee, whereby shallow pipes are formed that grow in the direction opposite to the flow. This pipe-forming process can ultimately lead to failure of a water-retaining structure and is considered one of the most important failure mechanisms for dikes and levees in the Netherlands and the United States. Modeling of this mechanism requires the assessment of hydraulic conditions in the pipe, which are controlled by the particle equilibrium at the pipe wall. Since the pipe’s dimensions are controlled by the inflow to the pipe from the porous medium, the flow through the pipe is thought to be laminar for fine-to medium-grained sands. The literature provides data for incipient motion in laminar flow, which is reviewed here and complemented with data from backward erosion experiments. The experiments illustrate the applicability of the laminar incipient motion data to determine the erosion pipe dimensions and corresponding pipe hydraulics for fine-to medium-grained sands, for the purpose of backward erosion piping modeling.

关键词： Internal erosion Backward erosion piping Cylindrical test Incipient motion Dikes Levees