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1

Energy Technology Data Exchange (ETDEWEB)

This presentation describes the development of the proposed Process Flow Diagram (PFD) for the Tokamak Exhaust Processing System (TEP) of ITER. A brief review of design efforts leading up to the PFD is followed by a description of the hydrogen-like, air-like, and waterlike processes. Two new design values are described; the mostcommon and most-demanding design values. The proposed PFD is shown to meet specifications under the most-common and mostdemanding design values.

Wilms, R Scott [Los Alamos National Laboratory; Carlson, Bryan [Los Alamos National Laboratory; Coons, James [Los Alamos National Laboratory; Kubic, William [Los Alamos National Laboratory

2008-01-01

2

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Many quality and safety improvement methods in healthcare rely on a complete and accurate map of the process. Process mapping in healthcare is often achieved using a sequential flow diagram, but there is little guidance available in the literature about the most effective type of process map to use. Moreover there is evidence that the organisation of information in an external representation affects reasoning and decision making. This exploratory study examined whether the type of process map - sequential or hierarchical - affects healthcare practitioners' judgments. Methods A sequential and a hierarchical process map of a community-based anti coagulation clinic were produced based on data obtained from interviews, talk-throughs, attendance at a training session and examination of protocols and policies. Clinic practitioners were asked to specify the parts of the process that they judged to contain quality and safety concerns. The process maps were then shown to them in counter-balanced order and they were asked to circle on the diagrams the parts of the process where they had the greatest quality and safety concerns. A structured interview was then conducted, in which they were asked about various aspects of the diagrams. Results Quality and safety concerns cited by practitioners differed depending on whether they were or were not looking at a process map, and whether they were looking at a sequential diagram or a hierarchical diagram. More concerns were identified using the hierarchical diagram compared with the sequential diagram and more concerns were identified in relation to clinical work than administrative work. Participants' preference for the sequential or hierarchical diagram depended on the context in which they would be using it. The difficulties of determining the boundaries for the analysis and the granularity required were highlighted. Conclusions The results indicated that the layout of a process map does influence perceptions of quality and safety problems in a process. In quality improvement work it is important to carefully consider the type of process map to be used and to consider using more than one map to ensure that different aspects of the process are captured.

Potts Henry WW

2010-01-01

3

Quantifying the implicit process flow abstraction in SBGN-PD diagrams with Bio-PEPA

For a long time biologists have used visual representations of biochemical networks to gain a quick overview of important structural properties. Recently SBGN, the Systems Biology Graphical Notation, has been developed to standardise the way in which such graphical maps are drawn in order to facilitate the exchange of information. Its qualitative Process Diagrams (SBGN-PD) are based on an implicit Process Flow Abstraction (PFA) that can also be used to construct quantitative representations, which can be used for automated analyses of the system. Here we explicitly describe the PFA that underpins SBGN-PD and define attributes for SBGN-PD glyphs that make it possible to capture the quantitative details of a biochemical reaction network. We implemented SBGNtext2BioPEPA, a tool that demonstrates how such quantitative details can be used to automatically generate working Bio-PEPA code from a textual representation of SBGN-PD that we developed. Bio-PEPA is a process algebra that was designed for implementing quant...

Loewe, Laurence; Hillston, Jane

2009-01-01

4

Quantifying the implicit process flow abstraction in SBGN-PD diagrams with Bio-PEPA

Directory of Open Access Journals (Sweden)

Full Text Available For a long time biologists have used visual representations of biochemical networks to gain a quick overview of important structural properties. Recently SBGN, the Systems Biology Graphical Notation, has been developed to standardise the way in which such graphical maps are drawn in order to facilitate the exchange of information. Its qualitative Process Diagrams (SBGN-PD are based on an implicit Process Flow Abstraction (PFA that can also be used to construct quantitative representations, which can be used for automated analyses of the system. Here we explicitly describe the PFA that underpins SBGN-PD and define attributes for SBGN-PD glyphs that make it possible to capture the quantitative details of a biochemical reaction network. We implemented SBGNtext2BioPEPA, a tool that demonstrates how such quantitative details can be used to automatically generate working Bio-PEPA code from a textual representation of SBGN-PD that we developed. Bio-PEPA is a process algebra that was designed for implementing quantitative models of concurrent biochemical reaction systems. We use this approach to compute the expected delay between input and output using deterministic and stochastic simulations of the MAPK signal transduction cascade. The scheme developed here is general and can be easily adapted to other output formalisms.

Jane Hillston

2009-10-01

5

Pfizer, Inc.'s Tissue Bank, in conjunction with Pfizer's BioBank (biofluid repository), endeavored to create an overarching internal software package to cover all general functions of both research facilities, including sample receipt, reconciliation, processing, storage, and ordering. Business process flow diagrams were developed by the Tissue Bank and Informatics teams as a way of characterizing best practices both within the Bank and in its interactions with key internal and external stakeholders. Besides serving as a first step for the software development, such formalized process maps greatly assisted the identification and communication of best practices and the optimization of current procedures. The diagrams shared here could assist other biospecimen research repositories (both pharmaceutical and other settings) for comparative purposes or as a guide to successful informatics design. Therefore, it is recommended that biorepositories consider establishing formalized business process flow diagrams for their laboratories, to address these objectives of communication and strategy. PMID:23386924

McDonald, Sandra A; Velasco, Elizabeth; Ilasi, Nicholas T

2010-12-01

6

New Working Diagram for Membrane Separation Processes.

First a short presentation of the work diagram for rectification processes (McCabe-Thiele-diagram) is given. Then a new work diagram suitable for membrane separation processes is developed. The application in pervaporation and gas separation under cross f...

K. Hattenbach

1985-01-01

7

Digital Repository Infrastructure Vision for European Research (DRIVER)

Pfizer, Inc.'s Tissue Bank, in conjunction with Pfizer's BioBank (biofluid repository), endeavored to create an overarching internal software package to cover all general functions of both research facilities, including sample receipt, reconciliation, processing, storage, and ordering. Business process flow diagrams were developed by the Tissue Bank and Informatics teams as a way of characterizing best practices both within the Bank and in its interactions with key internal and external stake...

Mcdonald, Sandra A.; Velasco, Elizabeth; Ilasi, Nicholas T.

2010-01-01

8

Formalization of the Data Flow Diagram Rules for Consistency Check

Directory of Open Access Journals (Sweden)

Full Text Available In system development life cycle (SDLC, a system model can be developed using Data Flow Diagram(DFD. DFD is graphical diagrams for specifying, constructing and visualizing the model of a system.DFD is used in defining the requirements in a graphical view. In this paper, we focus on DFD and itsrules for drawing and defining the diagrams. We then formalize these rules and develop the tool based onthe formalized rules. The formalized rules for consistency check between the diagrams are used indeveloping the tool. This is to ensure the syntax for drawing the diagrams is correct and strictly followed.The tool automates the process of manual consistency check between data flow diagrams.

Rosziati Ibrahim

2010-10-01

9

Flow phase diagram for helium superfluids

International Nuclear Information System (INIS)

The existence of the flow phase diagram predicted by Volovik is discussed based on available experimental data for He II and 3He-B. The effective temperature-dependent but scale-independent Reynolds number Reeff = 1/q ? (1-?')/?, where ? and ?' are the mutual friction parameters and the superfluid Reynolds number characterizing the circulation of the superfluid component in units of the circulation quantum are used as the dynamic parameters. In particular, the flow diagram allows identification of experimentally observed turbulent states I and II in counterflowing He II with the classical and quantum turbulent regimes suggested by Volovik

2004-10-01

10

Flow Phase Diagram for the Helium Superfluids

The flow phase diagram for He II and $^3$He-B is established and discussed based on available experimental data and the theory of Volovik [JETP Letters {\\bf{78}} (2003) 553]. The effective temperature - dependent but scale - independent Reynolds number $Re_{eff}=1/q=(1+\\alpha')/\\alpha$, where $\\alpha$ and $\\alpha'$ are the mutual friction parameters and the superfluid Reynolds number characterizing the circulation of the superfluid component in units of the circulation quantum are used as the dynamic parameters. In particular, the flow diagram allows identification of experimentally observed turbulent states I and II in counterflowing He II with the turbulent regimes suggested by Volovik.

Skrbek, L

2004-01-01

11

Study flow diagrams in Cochrane systematic review updates: an adapted PRISMA flow diagram.

Cochrane systematic reviews are conducted and reported according to rigorous standards. A study flow diagram must be included in a new review, and there is clear guidance from the PRISMA statement on how to do this. However, for a review update, there is currently no guidance on how study flow diagrams should be presented. To address this, a working group was formed to find a solution and produce guidance on how to use these diagrams in review updates.A number of different options were devised for how these flow diagrams could be used in review updates, and also in cases where multiple searches for a review or review update have been conducted. These options were circulated to the Cochrane information specialist community for consultation and feedback. Following the consultation period, the working group refined the guidance and made the recommendation that for review updates an adapted PRISMA flow diagram should be used, which includes an additional box with the number of previously included studies feeding into the total. Where multiple searches have been conducted, the results should be added together and treated as one set of results.There is no existing guidance for using study flow diagrams in review updates. Our adapted diagram is a simple and pragmatic solution for showing the flow of studies in review updates. PMID:24886533

Stovold, Elizabeth; Beecher, Deirdre; Foxlee, Ruth; Noel-Storr, Anna

2014-01-01

12

Shape diagram of vesicles in Poiseuille flow

Digital Repository Infrastructure Vision for European Research (DRIVER)

Soft bodies flowing in a channel often exhibit parachute-like shapes usually attributed to an increase of hydrodynamic constraint (viscous stress and/or confinement). We show that the presence of a fluid membrane leads to the reverse phenomenon and build a phase diagram of shapes --- which are classified as bullet, croissant and parachute --- in channels of varying aspect ratio. Unexpectedly, shapes are relatively wider in the narrowest direction of the channel. We highlight...

Coupier, Gwennou; Farutin, Alexander; Minetti, Christophe; Podgorski, Thomas; Misbah, Chaouqi

2012-01-01

13

Shape diagram of vesicles in Poiseuille flow

Soft bodies flowing in a channel often exhibit parachute-like shapes usually attributed to an increase of hydrodynamic constraint (viscous stress and/or confinement). We show that the presence of a fluid membrane leads to the reverse phenomenon and build a phase diagram of shapes --- which are classified as bullet, croissant and parachute --- in channels of varying aspect ratio. Unexpectedly, shapes are relatively wider in the narrowest direction of the channel. We highlight the role of flow patterns on the membrane in this response to the asymmetry of stress distribution.

Coupier, Gwennou; Minetti, Christophe; Podgorski, Thomas; Misbah, Chaouqi

2012-01-01

14

Using Functional Flow Diagrams to Enhance Technical Systems Understanding.

A treatment group of 20 aviation students used training manuals that presented functional flow diagrams before schematic diagrams. Comparison of data from 10 controls on a card-sort task showed that functional flow diagrams enhanced understanding of technical systems. (SK)

Satchwell, Richard E.

1997-01-01

15

Software Tool Integrating Data Flow Diagrams and Petri Nets

Data Flow Diagram - Petri Net (DFPN) is a software tool for analyzing other software to be developed. The full name of this program reflects its design, which combines the benefit of data-flow diagrams (which are typically favored by software analysts) with the power and precision of Petri-net models, without requiring specialized Petri-net training. (A Petri net is a particular type of directed graph, a description of which would exceed the scope of this article.) DFPN assists a software analyst in drawing and specifying a data-flow diagram, then translates the diagram into a Petri net, then enables graphical tracing of execution paths through the Petri net for verification, by the end user, of the properties of the software to be developed. In comparison with prior means of verifying the properties of software to be developed, DFPN makes verification by the end user more nearly certain, thereby making it easier to identify and correct misconceptions earlier in the development process, when correction is less expensive. After the verification by the end user, DFPN generates a printable system specification in the form of descriptions of processes and data.

Thronesbery, Carroll; Tavana, Madjid

2010-01-01

16

Energy Technology Data Exchange (ETDEWEB)

First a short presentation of the work diagram for rectification processes (McCabe-Thiele-diagram) is given. Then a new work diagram suitable for membrane separation processes is developed. The application in pervaporation and gas separation under cross flow is demonstrated. 16 figs., 1 tab.

Hattenbach, K.

1985-01-01

17

A Formal Model for Data Flow Diagram Rules

Directory of Open Access Journals (Sweden)

Full Text Available A formal model for data flow diagram (DFD rules is developed by introducing a syntax and semantics for its rules. DFD has been chosen because it is an approach for specifying, constructing and visualizing the model of a system graphically and has been in practical use on a very wide basis but still lacks formal and precise understanding. This formal model can be used to check the correctness of the diagrams and consistency among the diagrams.

Rosziati Ibrahim

2011-05-01

18

Activated sludge process control--development of operational diagrams.

Hindered batch settling experiments were performed on activated sludge generated from dairy wastewater and combined (Dairy-Domestic mixture 1:3) wastewater for different initial Mixed Liquor Suspended Solids (MLSS) concentrations from 2g/L to 20 g/L for varied Mean Cell Residence Time (MCRT) for 5 to 15 days. Bio kinetic coefficients of combined wastewater were determined using a bench scale Continues Flow Stirred Tank Reactor (CFSTR). Vesilind parameters were also determined experimentally. Operational diagrams for long-term fluctuations in plant inflow and substrate concentration have been prepared. The allowable overflow rate to prevent process failure can be predicted from the chart. The adjustments to be made in recycling ratio and MCRT in case of fluctuations could also be predicted from the operational diagrams. From the operating diagrams plotted for both dairy and combined wastewater, it was noticed that, combined wastewater treatment provide greater operational flexibility than treating dairy waste separately. PMID:17365299

Jeyanthi, J; Saseetharan, M K

2007-02-15

19

Material flow of production process

Directory of Open Access Journals (Sweden)

Full Text Available This paper deals with material flow of the production process. We present the block diagram of material flow and capacities of engine in various plants each other. In this paper is used IPO (Input ? Process ? Output diagram. IPO diagram described process with aspect to input and output. Production program regards string of precision, branch and paralel processes with aspect IPO diagram.Process is not important with aspect to events. We are looking on the process as a ?black box?. For process is used different materials and raw materials. The foudation for material analysis is detailed model of production process with defined flow material, energy, waste etc.Material flow is organised move of mass (material, money, informations, people etc.. Material analysis is made against destination of material flow (i.e. from ending to beginning. Material analysis is performed on the detection demand of individual materials, stocks, forms, etc.For elementary materials and raw materials in which is based production program and which to create better part of production costs is mainly necessary to dedicate the remark. The fluency of material flow concentrates on the respect of the capacitive parameters for individual node from aspect to standardized qualitative parameters and allowed limits.

Hanzelová Marcela

2001-12-01

20

AUTO-LAY: automatic layout generation for procedure flow diagrams

International Nuclear Information System (INIS)

Nuclear Power Plant Procedures can be seen from essentially two viewpoints: the process and the information management. From the first point of view, it is important to supply the knowledge apt to solve problems connected with the control of the process, from the second one the focus of attention is on the knowledge representation, its structure, elicitation and maintenance, formal quality assurance. These two aspects of procedure representation can be considered and solved separately. In particular, methodological, formal and management issues require long and tedious activities, that in most cases constitute a great barrier for procedures development and upgrade. To solve these problems, Ansaldo is developing DIAM, a wide integrated tool for procedure management to support in procedure writing, updating, usage and documentation. One of the most challenging features of DIAM is AUTO-LAY, a CASE sub-tool that, in a complete automatical way, structures parts or complete flow diagrams. This is a feature that is partially present in some other CASE products, that, anyway, do not allow complex graph handling and isomorphism between video and paper representation AUTO-LAY has the unique prerogative to draw graphs of any complexity, to section them in pages, and to automatically compose a document. This has been recognized in the literature as the most important second-generation CASE improvement. (author). 5 refs., 9 figs

1995-06-04

21

The Exergy of Lift and Aircraft Exergy Flow Diagrams

Directory of Open Access Journals (Sweden)

Full Text Available Aside from incidental, auxiliary loads, in level flight the principal load on the aircraft propulsion engine is the power required to provide the continuous lift. To construct an exergy flow diagram for an aircraft – for example, for the purpose of pinpointing inefficiencies and for costing – an expression is needed for the exergy delivered to and by the wings. That is, an expression is needed for the exergy of lift. The purpose of this paper is to present an expression developed for the exergy of lift, applicable not only in level flight but in other modes of flight as well. In order to illustrate the relevance of exergy of lift, two exergy flow diagrams are presented for a light aircraft, one for level flight, and one for climb.

Richard A. Gaggioli

2003-12-01

22

Microsoft Visio 2013 business process diagramming and validation

Microsoft Visio 2013 Business Process Diagramming and Validation provides a comprehensive and practical tutorial including example code and demonstrations for creating validation rules, writing ShapeSheet formulae, and much more.If you are a Microsoft Visio 2013 Professional Edition power user or developer who wants to get to grips with both the essential features of Visio 2013 and the validation rules in this edition, then this book is for you. A working knowledge of Microsoft Visio and optionally .NET for the add-on code is required, though previous knowledge of business process diagramming

Parker, David

2013-01-01

23

Fundamental Diagram of Traffic Flows on Urban Roads Local Versus Whole-Link Approaches

Digital Repository Infrastructure Vision for European Research (DRIVER)

Fundamental diagrams of traffic flow variables have been quite useful in determining freeway operations quality. However, they are usually not used for that purpose on urban roads. This work is an approach toward utilizing the fundamental diagram on urban roads. On the basis of a host of empirical and simulation work, the first steps toward a routine application of the fundamental diagram are sketched. In addition, two approaches are compared, the first uses a traditional fundamental diagram ...

Wagner, Peter; Brockfeld, Elmar; Gartner, Nathan H.; Sohr, Alexander

2009-01-01

24

Improving The Decisional Process By Using UML Diagrams

Directory of Open Access Journals (Sweden)

Full Text Available In the last years, the world has moved from predominantly industrial society to information society, governed by a new set of rules, which allows access to digital technologies, processing, storage and transmission of information. Organizations include in their decisional process Business Intelligence components, which help the decision-makers to establish the conditions of financial equilibrium, to highlight weaknesses and strengths, to make predictions.Particularly, Unified Modelling Language (UML, as a formal and standardized language, allows the control of the system’s complexity, shows different but complementary views of the organization and ensures independence towards the implementation language and the domain of application. This article aims to show the way UML diagrams are used as support in a decisional process for a hotel company. UML diagrams designed help decisionmakers to analysis and discover the causes, to design and simulation of possible scenarios, to implement and measuring the results.

Udrica Mioara

2012-06-01

25

Phase diagrams properties of the mixed traffic flow on a crossroad

Based on the Ishibashi and Fukui crossroad traffic flow model [Y. Ishibashi and M. Fukui. J. Phys. Soc. Japan. 70 (2001) 2793], mixed traffic flow (i.e., the fast and slow vehicles with different maximum velocities are mixed) is investigated in this work. According to the numerical simulation results and the principle for constructing the phase diagram, phase diagrams for mixed traffic flow are constructed. It is noted that the topology of these phase diagrams is similar to that of phase diagrams for homogeneous vehicles (which refers to slow vehicles only). From the phase diagrams, it is evident that mixed traffic flow is influenced by the mixing rate f (fraction of slow and fast vehicles) in regions II and V, but not in other regions. Although a mixture of fast and slow vehicles is introduced in the crossroad traffic flow model, the separation between phases in the phase diagrams remains linear. For a given q (the vehicle density on the northbound road), one flow plateau appears in regions IIx or IVy, while two maximum flow plateaus appear in region V in each of the phase diagrams. The maximum flow values in region V reflect the maximum traffic capacity for the traffic system as defined in this work. Since mixed traffic flow is a common phenomenon in real traffic, this work may offer help in real traffic simulations and traffic management.

Li, Qi-Lang; Wang, Bing-Hong; Liu, Mu-Ren

2010-11-01

26

Design of processes with reactive distillation line diagrams

Energy Technology Data Exchange (ETDEWEB)

On the basis of the transformation of concentration coordinates, the concept of reactive distillation lines is developed. It is applied to study the feasibility of a reactive distillation with an equilibrium reaction on all trays of a distillation column. The singular points in the distillation line diagrams are characterized in terms of nodes and saddles. Depending on the characterization of the reactive distillation line diagrams, it can be decided whether a column with two feed stages is required. On the basis of the reaction space concept, a procedure for identification of reactive distillation processes is developed, in which the reactive distillation column has to be divided into reactive and nonreactive sections. This can be necessary to overcome the limitations in separation which result from the chemical equilibrium. The concentration profile of this combined reactive/nonreactive distillation column is estimated using combined reactive/nonreactive distillation lines.

Bessling, B. [BASF Ludwigshafen (Germany). Engineering Research and Development; Schembecker, G.; Simmrock, K.H. [Univ. of Dortmund (Germany). Dept. of Chemical Engineering

1997-08-01

27

Thermodynamic methodology of energy-flow framework diagram for technical energy systems

International Nuclear Information System (INIS)

This paper presents a novel thermodynamic analysis tool, the energy-flow framework diagram (EFD), and proposes a new method called the EFD graphic analysis method. It is a visual method of energy analysis and integration and is fairly convenient to analyze variety of complicated information, with the aim at bring forward a creative energy-saving system. It is proved that the new method is effective and useful through an application study on a 560 kt/a methanol synthesis process by means of the EFD and the revelatory criteria

2002-07-03

28

Thermodynamic methodology of energy-flow framework diagram for technical energy systems

Energy Technology Data Exchange (ETDEWEB)

This paper presents a novel thermodynamic analysis tool, the energy-flow framework diagram (EFD), and proposes a new method called the EFD graphic analysis method. It is a visual method of energy analysis and integration and is fairly convenient to analyze variety of complicated information, with the aim at bring forward a creative energy-saving system. It is proved that the new method is effective and useful through an application study on a 560 kt/a methanol synthesis process by means of the EFD and the revelatory criteria. (author)

Zheng, D.; Yao, R. [Beijing University of Chemical Technology (China). School of Chemical Engineering; Jin, H. [Chinese Academy of Sciences, Beijing (China). Institute of Engineering Thermophysics

2002-12-01

29

Thermodynamic methodology of energy-flow framework diagram for technical energy systems

Energy Technology Data Exchange (ETDEWEB)

This paper presents a novel thermodynamic analysis tool, the energy-flow framework diagram (EFD), and proposes a new method called the EFD graphic analysis method. It is a visual method of energy analysis and integration and is fairly convenient to analyze variety of complicated information, with the aim at bring forward a creative energy-saving system. It is proved that the new method is effective and useful through an application study on a 560 kt/a methanol synthesis process by means of the EFD and the revelatory criteria.

Zheng, D.; Yao, R.; Jin, H

2004-12-01

30

Process Technical Basis Documentation Diagram for a solid-waste processing facility

Energy Technology Data Exchange (ETDEWEB)

The Process Technical Basis Documentation Diagram is for a solid-waste processing facility that could be designed to treat, package, and certify contact-handled mixed low-level waste for permanent disposal. The treatment processes include stabilization using cementitious materials and immobilization using a polymer material. The Diagram identifies several engineering/demonstration activities that would confirm the process selection and process design. An independent peer review was conducted at the request of Westinghouse Hanford Company to determine the technical adequacy of the technical approach for waste form development. The peer review panel provided comments and identified documents that it felt were needed in the Diagram as precedence for Title I design. The Diagram is a visual tool to identify traceable documentation of key activities, including those documents suggested by the peer review, and to show how they relate to each other. The Diagram is divided into three sections: (1) the Facility section, which contains documents pertaining to the facility design, (2) the Process Demonstration section, which contains documents pertaining to the process engineering/demonstration work, and 3) the Regulatory section, which contains documents describing the compliance strategy for each acceptance requirement for each feed type, and how this strategy will be implemented.

Benar, C.J.; Petersen, C.A.

1994-02-01

31

Directory of Open Access Journals (Sweden)

Full Text Available This paper describes the syntax and semantics of multi-level state diagrams to support probabilistic behavior of cooperating robots. The techniques are presented to analyze these diagrams by querying combined robots behaviors. It is shown how to use state abstraction and transition abstraction to create, verify and process large probabilistic state diagrams.

Bogdan Czejdo

2011-01-01

32

Lifting business process diagrams to 2.5 dimensions

In this work, we describe our visualization approach for business processes using 2.5 dimensional techniques (2.5D). The idea of 2.5D is to add the concept of layering to a two dimensional (2D) visualization. The layers are arranged in a three-dimensional display space. For the modeling of the business processes, we use the Business Process Modeling Notation (BPMN). The benefit of connecting BPMN with a 2.5D visualization is not only to obtain a more abstract view on the business process models but also to develop layering criteria that eventually increase readability of the BPMN model compared to 2D. We present a 2.5D Navigator for BPMN models that offers different perspectives for visualization. Therefore we also develop BPMN specific perspectives. The 2.5D Navigator combines the 2.5D approach with perspectives and allows free navigation in the three dimensional display space. We also demonstrate our tool and libraries used for implementation of the visualizations. The underlying general framework for 2.5D visualizations is explored and presented in a fashion that it can easily be used for different applications. Finally, an evaluation of our navigation tool demonstrates that we can achieve satisfying and aesthetic displays of diagrams stating BPMN models in 2.5D-visualizations.

Effinger, Philip; Spielmann, Johannes

2010-01-01

33

International Nuclear Information System (INIS)

Trajectories of renormalization group flows of N=2 super Landau-Ginzburg field theories are mapped out on the phase diagram N=2 superconformal field theories (SCFTs). It is shown that coupling constants flow on one and the same bifurcation set due to the non-renormalization theorem and the scaling properties of the bifurcation sets. (author). 17 refs, 2 figs

1989-01-01

34

Flow regimes and phase diagram of inertial particle suspensions

The aim of this Letter is to characterize the flow regimes of suspensions of finite-size solid particles in a viscous fluid at finite inertia. We explore the system behavior as function of the particle volume fraction and the Reynolds number (the ratio of flow and particle inertia to viscous forces). Unlike single phase flows where a clear distinction exists between the laminar and the turbulent regime, three different states can be identified in the presence of a particulate phase, with smooth transitions between them. At low volume fractions, the flow becomes turbulent when increasing the Reynolds number, transitioning from the laminar regime dominated by viscous forces to the turbulent regime characterized by enhanced momentum transport by turbulent eddies. At larger volume fractions, we identify a new state characterized by an even larger increase of the wall friction. The wall friction increases with the Reynolds number (inertial effects) while the turbulent transport is unaffected, as in a state of inte...

Lashgari, Iman; Breugem, Wim-Paul; Brandt, Luca

2014-01-01

35

Reporting of participant flow diagrams in published reports of randomized trials

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Background Reporting of the flow of participants through each stage of a randomized trial is essential to assess the generalisability and validity of its results. We assessed the type and completeness of information reported in CONSORT (Consolidated Standards of Reporting Trials) flow diagrams published in current reports of randomized trials. Methods A cross sectional review of all primary reports of randomized trials which included a CONSORT flow diag...

Hopewell Sally; Hirst Allison; Collins Gary S; Mallett Sue; Yu Ly-Mee; Altman Douglas G

2011-01-01

36

Interpreting Evolutionary Diagrams: When Topology and Process Conflict

The authors argue that some diagrams in biology textbooks and the popular press presented as depicting evolutionary relationships suggest an inappropriate (anagenic) conception of evolutionary history. The goal of this research was to provide baseline data that begin to document how college students conceptualize the evolutionary relationships…

Catley, Kefyn M.; Novick, Laura R.; Shade, Courtney K.

2010-01-01

37

Information Flow in the Launch Vehicle Design/Analysis Process

This paper describes the results of a team effort aimed at defining the information flow between disciplines at the Marshall Space Flight Center (MSFC) engaged in the design of space launch vehicles. The information flow is modeled at a first level and is described using three types of templates: an N x N diagram, discipline flow diagrams, and discipline task descriptions. It is intended to provide engineers with an understanding of the connections between what they do and where it fits in the overall design process of the project. It is also intended to provide design managers with a better understanding of information flow in the launch vehicle design cycle.

Humphries, W. R., Sr.; Holland, W.; Bishop, R.

1999-01-01

38

Prediction of Forming Limit Diagrams for 22MnB5 in Hot Stamping Process

Hot stamping of ultra-high strength steels possesses many superior characteristics over conventional room temperature forming process and is fairly attractive in improving strength and reducing weight of vehicle body product. However, the mechanical and failure behavior of hot stamping boron steel 22MnB5 are both strongly affected by strain hardening, temperature, strain rate, and microstructure. In this paper, the material yield and flow behavior of 22MnB5 within the temperature and strain rate range of hot stamping are described by an advanced anisotropic yield criterion combined with two different hardening laws. The elevated temperature forming limit diagram (ET-FLD) is constructed using the M-K theoretical analysis. The developed model was validated by comparing our predicted result with experimental data in the literature under isothermal conditions. Based on the verified model, the influence of temperature and strain rate on the forming limit curve for 22MnB5 steel under equilibrium isothermal condition are discussed. Furthermore, the transient forming limit diagram is developed by performing a transient forming process simulation under non-isothermal transient condition.

Li, Hongzhou; Wu, Xin; Li, Guangyao

2013-08-01

39

XML transformation flow processing

Digital Repository Infrastructure Vision for European Research (DRIVER)

The XSLT language is both complex to use in simple cases (like tag renaming or element hiding) and restricted in complex ones (requiring the processing of multiple stylesheets with complex information flows). We propose a framework improving on XSLT. It provides simple-to-use and easy-to-analyze macros for the basic common transformation tasks. It provides a superstructure for composing multiple stylesheets, with multiple input and output documents, in ways that are not accessible within XSLT...

Euzenat, Je?ro?me; Tardif, Laurent

2001-01-01

40

XML transformation flow processing

Digital Repository Infrastructure Vision for European Research (DRIVER)

The XSLT language is both complex to use in simple cases (like tag renaming or element hiding) and restricted in complex ones (requiring the processing of multiple stylesheets with complex information flows). We propose a framework improving on XSLT. It provides simple-to-use and easy-to-analyze macros for the basic common transformation tasks. It provides a superstructure for composing multiple stylesheets, with multiple input and output documents, in ways that are not accessible within XSLT...

Euzenat, Je?ro?me; Tardif, Laurent

2002-01-01

41

Non-resonant diagrams in radiative four-fermion processes

International Nuclear Information System (INIS)

The complete tree level cross section for e"+e"- ? e"-?-bar_eud-bar? is computed and discussed in comparison with the cross sections for e"+e"- ? e"-V-bar_e u d-bar and e"+e"- ? u-bar d u d-bar. Event generators based on the GRACE package for the non-radiative and radiative case are presented. Special interest is brought to the effect of the non-resonant diagrams overlooked so far in other studies. Their contribution to the total cross section is presented for the LEP II energy range for future linear colliders (?s = 500 GeV). (author)

1994-04-10

42

Non-resonant diagrams in radiative four-fermion processes

Energy Technology Data Exchange (ETDEWEB)

The complete tree level cross section for e{sup +}e{sup -} {yields} e{sup -}{nu}-bar{sub e}ud-bar{gamma} is computed and discussed in comparison with the cross sections for e{sup +}e{sup -} {yields} e{sup -}V-bar{sub e} u d-bar and e{sup +}e{sup -} {yields} u-bar d u d-bar. Event generators based on the GRACE package for the non-radiative and radiative case are presented. Special interest is brought to the effect of the non-resonant diagrams overlooked so far in other studies. Their contribution to the total cross section is presented for the LEP II energy range for future linear colliders ({radical}s = 500 GeV). (author). 10 refs.

Fujimoto, J.; Ishikawa, T.; Kawabata, S.; Kurihara, Y.; Perret-Gallix, D. [Grenoble-1 Univ., 74 - Annecy (France). Lab. de Physique des Particules Elementaires; Shimizu, Y. [National Lab. for High Energy Physics, Tsukuba, Ibaraki (Japan)

1994-06-01

43

International Nuclear Information System (INIS)

In the present study the annealing behavior of 60% reduced and stress relieved Zircaloy-4 nuclear fuel cladding tube is studied over a temperature range of 300-1000 deg. C and an annealing time range of 103 to 105 s. The annealing effects were monitored using Knoop microhardness measurements and flow stress diagrams were developed to study the mechanical anisotropy evolution in the tubing. The determined values of the mechanical anisotropy ratios show that the tubing undergoes a significant mechanical anisotropy evolution during annealing

2008-02-15

44

Power diagrams and interaction processes for unions of discs

DEFF Research Database (Denmark)

Â We study a flexible class of finite-disc process models with interaction between the discs. We let U denote the random set given by the union of discs, and use for the disc process an exponential family density with the canonical sufficient statistic depending only on geometric properties of U such as the area, perimeter, Euler-PoincarÃ© characteristic, and the number of holes. This includes the quermass-interaction process and the continuum random-cluster model as special cases. Viewing our model as a connected component Markov point process, and thereby establishing local and spatial Markov properties, becomes useful for handling the problem of edge effects when only U is observed within a bounded observation window. The power tessellation and its dual graph become major tools when establishing inclusion-exclusion formulae, formulae for computing geometric characteristics of U, and stability properties of the underlying disc process density. Algorithms for constructing the power tessellation of U and for simulating the disc process are discussed, and the software is made public available. Udgivelsesdato: JUN

MÃ¸ller, Jesper; Helisova, Katerina

2008-01-01

45

Digital analysis and potato tissue image processing at the application of voronofs diagrams*

Directory of Open Access Journals (Sweden)

Full Text Available In this paper image processing is presented from the point of view of obtaining cell wall image. We also proposed some measurement and analysis methods. Because of non-continuos character of plant structure, the authors applied Voronoi's diagrams. This model allows for application of some point co-ordinates and segment lengths only. Also Voronoi's diagrams make easier obtaining a few parameters important for geometrical properties of cell wall. Color microscope images have been converted from RGB system into HLS system which enabled to obtain information about the space configuration of point of objects being investigated and to identify structural elements.

A. Guc

1995-12-01

46

Non-compact lattice QED with two charges phase diagram and renormalization group flow

The phase diagram of non-compact lattice QED in four dimensions with staggered fermions of charges 1 and -1/2 is investigated. The renormalized charges are determined and found to be in agreement with perturbation theory. This is an indication that there is no continuum limit with non-vanishing renormalized gauge coupling, and that the theory has a validity bound for every finite value of the renormalized coupling. The renormalization group flow of the charges is investigated and an estimate for the validity bound as a function of the cut-off is obtained. Generalizing this estimate to all fermions in the Standard Model,it is found that a cut-off at the Planck scale implies that \\alpha_R has to be less than 1/80. Due to spontaneous chiral symmetry breaking, strongly bound fermion-antifermion composite states are generated. Their spectrum is discussed.

Khan, A A

1996-01-01

47

Ring diagram analysis of near-surface flows in the Sun

Ring diagram analysis of solar oscillation power spectra obtained from MDI data is carried out to study the velocity fields in the outer part of the solar convection zone. The three dimensional power spectra are fitted to a model which has a Lorentzian profile in frequency and which includes the advection of the wave front by horizontal flows, to obtain the two components of the sub-surface flows as a function of the horizontal wave number and radial order of the oscillation modes. This information is then inverted using OLA and RLS methods to infer the variation in horizontal flow velocity with depth. The average rotation velocity at different latitudes obtained by this technique agrees reasonably with helioseismic estimates made using frequency splitting data. The shear layer just below the solar surface appears to consist of two parts with the outer part up to a depth of 4 Mm, where the velocity gradient does not show any reversal up to a latitude of 60 degrees. In the deeper part the velocity gradient sho...

Basu, S; Tripathy, S C; Basu, Sarbani

1999-01-01

48

Development of the web-based site investigation flow diagram in repository development program

International Nuclear Information System (INIS)

In siting a repository for high level radioactive wastes (HLW), it is essential for consensus building intelligibly and visually present why and how the area is selected as a suitable site. However 'information asymmetry' exists especially between society and an implementation body because various types of investigation, analysis and assessment are implemented in site characterization on the basis of a wide variety of advanced science and technology. Communication between experts (e.g. surveyors and modelers) is also important for efficient and reliable site investigation/ characterization. The Web-based Site Investigation Flow Diagram (SIFD) has been developed as a tool for information sharing among stake holders and society-jointed decision making. To test applicability of the SIFD, virtual site characterization ('dry run') is performed using the existing site investigation data. It is concluded that the web-based SIFD enhance traceability and transparency of the site investigation/ characterization, and therefore it would be a powerful communication tool among experts for efficient and reliable site investigation/characterization and among stake holders for consensus building

2005-11-01

49

From State Diagram to Class Diagram

DEFF Research Database (Denmark)

UML class diagram and Java source code are interrelated and Java code is a kind of interchange format. Working with UML state diagram in CASE tools, a corresponding xml file is maintained. Designing state diagrams is mostly performed manually using design patterns and coding templates - a time consuming process. This article demonstrates how to compile such a diagram into Java code and later, by reverse engineering, produce a class diagram. The process from state diagram via intermediate SAX parsed xml file to Apache Velocity generated Java code is described. The result is a fast reproducible Java code minimizing maintenance.

Borch, Ole; Madsen, Per Printz

2009-01-01

50

A new approach to construct generalized local Voronoi diagrams via digital image processing

A robot navigating in an unknown environment depends on its sensors to obtain distance information of the obstacles with which it encounters. By using the collected distance information, a point robot is able to construct Generalized Local Voronoi Diagram (GLVD) of the area that is lying in vicinity of itself. In this paper, a method is proposed to build GLVDs via processing the digital images captured by a camera attached to a point robot which remains on a constant height platform. The robot under consideration collects several discrete images around itself. These images are processed by an algorithm which extracts the distance information of the three dimensional obstacles around the robot and constructs discrete images which are parts of the top view of the area. The resulting discrete images are then assembled to build a complete image of the top view of the region around the robot, at the center of which the robot is located. This local panoramic image is then used to construct the GLVD of the area under consideration. A case study is presented to demonstrate and verify the capabilities of the approach introduced. To the best of authors' knowledge, this is the first study which employs a camera attached to the robot itself and digital image processing to create Generalized Local Voronoi Diagrams.

Yümer, M. Ersin; Koçer, Bilge; Tosun, M. Bilgehan

2010-02-01

51

Flow Logic for Process Calculi

DEFF Research Database (Denmark)

Flow Logic is an approach to statically determining the behavior of programs and processes. It borrows methods and techniques from Abstract Interpretation, Data Flow Analysis and Constraint Based Analysis while presenting the analysis in a style more reminiscent of Type Systems. Traditionally developed for programming languages, this article provides a tutorial development of the approach of Flow Logic for process calculi based on a decade of research. We first develop a simple analysis for the Ï?-calculus; this consists of the specification, semantic soundness (in the form of subject reduction and adequacy results), and a Moore Family result showing that a least solution always exists, as well as providing insights on how to implement the analysis. We then show how to strengthen the analysis technology by introducing reachability components, interaction points, and localized environments, and finally, we extend it to a relational analysis. A Flow Logic is a program logic---in the same sense that a Hoareâ??s logic is. We conclude with an executive summary presenting the highlights of the approach from this perspective including a discussion of theoretical properties as well as implementation considerations. The electronic supplements present an application of the analysis techniques to a version of the Ï?-calculus incorporating distribution and code mobility; also the proofs of the main results can be found in the electronic supplements.

Nielson, Hanne Riis; Nielson, Flemming

2012-01-01

52

Meaning and Abduction as Process-Structure: A Diagram of Reasoning

Directory of Open Access Journals (Sweden)

Full Text Available This paper is informed by Charles Sanders Peirce’s philosophy as semiotics or the doctrine of signs. The paper’s purpose is to explore Peirce’s category of abduction as not being limited to the inference to the best explanation. In the context of the logic of discovery, abduction is posited as a necessary although not sufficient condition for the production of meanings. The structure of a genuine sign is triadic and represents a synthesis between precognitive ideas and conceptual representations. The novel model of reasoning is offered, based on the mathematical formalism borrowed from Gauss’ interpretation of the complex number. It is suggested that this model in a form of a diagram not only represents a semiotic process-structure but also overcomes the long-standing paradox of new knowledge. For Peirce, it is a diagram as a visual representation that may yield solutions to the otherwise unsolvable logical problems. What appears to us as a paradox is the very presence of abductive, or hypothetical, inference, as Peircean generic category of Firstness within the Thirdness of the total thought-process. Firstness (feeling, Secondness (action, and Thirdness (reason together constitute a dynamic structure of experience.

Inna Semetsky

2009-11-01

53

These online resources offer varied opportunities to work with Venn diagrams, one of many tools used in logic and reasoning. Their use is especially helpful in learning foundational notions of definition and set theory. One of the five Process Standards promoted by NCTM, Reasoning and Proof requires middle school students to sharpen such skills as they learn to develop mathematical argument.

National Science Digital Library (NSDL) Middle School Portal Staff

2008-03-10

54

Evolution of the Near-surface Flows Inferred from High-resolution Ring-diagram Analysis of HMI Data

Ring-diagram analysis of acoustic waves observed at the photosphere provides in principle a relatively robust determination of the sub-surface flows at a particular time under a particular region. The depth of penetration of the waves is related to the size of the region, hence the depth extent of the measured flows is inversely proportional to the spatial resolution. Most ring-analysis has focused on regions of extent ~15 deg (200 Mm) or more in order to provide reasonable mode sets for inversions. The HMI analysis pipeline however also provides a set of ring fit parameters on a scale three times smaller. These provide flow estimates for the outer 1% (7 Mm) of the Sun only, with very limited depth resolution, but with spatial resolution adequate to map structures.potentially associated with the belts and regions of magnetic activity. There are a number of systematic effects affecting the determination of flows from local helioseismic analysis of regions over different parts of the observable disc, not all well-understood. In this study we characterize those systematic effects with higher spatial resolution. This enable us to remove them more effectively as we map the temporal and spatial evolution of the flows, leaving open the question of their mean structure which is most affected by the systematics. We present results for the ring-diagram determination of the flow anomalies corresponding to the torsional oscillation pattern in differential rotation and analogous patterns in the meridional cell structure over the early part of the current solar cycle observed by HMI.

Bogart, Richard S.; Baldner, Charles; Basu, Sarbani

2014-06-01

55

ISSUES CONCERNING THE USE OF UML DIAGRAMS TO DEFINE THE UNDERLYING PROCESS MODEL SIMULATION

Directory of Open Access Journals (Sweden)

Full Text Available Diagrams are a graphical representation of the information contained in a UML model, and are an essential feature of UML modelling. Each UML diagram is designed to let you view a software system from a different perspective and to varying levels of abstraction.

MIOARA UDRIC?

2011-01-01

56

International Nuclear Information System (INIS)

Between 13th and 16th January 2005, NOA active region 10720 was the site of several large flares, one of which induced a solar quake. The expanding wave front of the quake was visible across the surface, causing both horizontal and vertical plasma displacements. Using a new temporal scanning technique for ring diagram analysis of SOHO/MDI (Michelson Doppler imager on board the Solar and Heliospheric Observatory) dopplergrams, we have calculated the horizontal and vertical velocity flows within the active region and the surrounding areas to a depth of 15Mm. We have been able to prove that it is possible to determine changes to a steadily varying subsurface flow, over time scales of hours.

2011-01-01

57

Top-down versus bottom-up processing of influence diagrams in probabilistic analysis

International Nuclear Information System (INIS)

Recent work by Phillips and Selby has shown that influence diagram methodology can be a useful analytical tool in reactor safety studies. In some instances an influence diagram can be used as a graphical representation of probabilistic dependence within a system or event sequence. Under these circumstances, Bayesian statistics is employed to transform the relationships depicted in the influence diagram into the correct expression for a desired marginal probability (e.g. the top node). Top-down and bottom-up algorithms have emerged as the dominant methods for quantifying influence diagrams. The purpose of this paper is to demonstrate a potential error in employing the bottom-up algorithm when dealing with interdependencies

1986-06-15

58

Petri net to ladder logic diagram converter and a batch process simulation

Directory of Open Access Journals (Sweden)

Full Text Available Discrete-event dynamic systems (DEDS are characterized by a set of states which the system can take, and by the set of asynchronous events that cause the state changes at discrete time points. Programmable logic controllers (PLCs are still important special purpose computers used to automate the DEDS in industry. Ladder logic diagrams (LLDs are still the most popular graphical programming tools of the PLCs; but the major problem is that programming is done heuristically and the LLDs are difficult to be used for both analysis and performance evaluation. Petri nets (PNs are nowadays the most effective modeling environment for both the design and implementation of DEDS. This paper proposes a PN to LLD conversion tool, used for graphical editing of a PN net model of a DEDS controller and for converting this PN into the equivalent LLD for programming a PLC. The conversion algorithm is presented, considering many types of transitions, places, and arcs with generality that many types of PNs can be considered. This paper also presents a simulation of a batch process, on a personal computer from one side, interfaced with a real PLC from the other side, that is programmed using a LLD obtained from the conversion of a suitable PN model using the proposed conversion tool. Compared with a LDD got heuristically, the LLD got from a PN conversion is simpler, understandable, and meeting all the characteristics obtained from the PN analysis.

Mostafa M. Gomaa

2011-02-01

59

International Nuclear Information System (INIS)

Transient freezing of molten UO2 and UO2-steel mixtures in steel channels is an important functional heat transfer process which occurs in the course of Liquid Metal-Cooled Fast Breeder Reactor (LMFBR) Hypothetical Core Disruptive Accidents (HCDA). Fuel freezing processes can influence both the transient overpower (TOP) and transient undercooling (TUC) accidents. In the absence of freezing, either fuel sweepout or continuous fuel removal can lead to shutdown with a largely coolable geometry in the TOP case and greatly reduce concerns over recriticality in the TUC case. However, with fuel freezing either case may lead to a temporarily ''bottled-up core'' condition which is relieved by melting of the initially formed plugs. Whether further freezing occurs in either the upward or downward direction through the core support structure is of interest in determining the decay heat level for Post-Accident Heat Removal (PAHR). Attention is focused on the freezing of ceramic fuel in steel channels. A discussion of the conduction-controlled and bulk freezing mechanisms is given first. A fuel crust stability criterion is proposed, and an explicit formula providing a rough estimate of critical fuel crust disintegration conditions is developed. A comparison of the crust stability criterion with a number of explanatory experimental results is made. A steel ablation-fuel freezing mechanism is identified. If the conditions in the fuel flow are such to prevent fuel crust growth, then the steel wall melting can become catastrophic. Steel ablation rapidly leads to fuel freezing in a bulk manner via turbulent mixing between the relatively ''cold'' molten steel and hot molten fuel. Based on this ablation-freezing concept, simple equations are developed for molten fuel penetration into steel channels. Comparison of the equations with the available experimental results proves favorable

1977-01-01

60

Energy Technology Data Exchange (ETDEWEB)

Having an instruction for a chemical analysis (e.g. german DIN-Norm, ISO-Standard) in its textual representation is not very helpful for the laboratory assistant. Therefore it is recommended to transform it into a graphical diagram. The symbols being used for this is a must and they are defined in the DIN 32650. Using the program `Analyse-Ablaufplan-Editor (AAE)`, i.e. `analytical flowing diagram editor`, enables you to make this transformation by computer. The data stored by this program can also be used for controlling and supervising the analysis in the laboratory. Function and handling of the AAE-program is described in this paper. (orig.) [Deutsch] Um eine in Textform verfasste DIN-Norm bzw. ISO-Standard fuer chemische Analysevorschriften fuer den Laboranten uebersichtlicher zu gestalten, empfiehlt sich die Umsetzung in eine grafische Darstellung. Die dafuer zu verwendenden grafischen Symbole sind festgelegt in der DIN 32650. Mit dem Programm Analyse-Ablaufplan-Editor (AAE) kann diese Umsetzung per Computer gemacht werden. Die damit erfassten Daten bilden gleichzeitig die Basis zur Steuerung und Ueberwachung der Analysen im Labor. Im folgenden Bericht wird die Handhabung und die Funktionsweise des AAE beschrieben. (orig.)

Orth, H.; Zilly, G.; Rosenbeck, P. [Rosenbeck, Woerth a.d. Donau (Germany)

1993-10-01

61

We present phase diagrams of the single red blood cell and biconcave capsule dynamics in dilute suspension using three-dimensional numerical simulations. The computational geometry replicates an in vitro linear shear flow apparatus. Our model includes all essential properties of the cell membrane, namely, the resistance against shear deformation, area dilatation, and bending, as well as the viscosity difference between the cell interior and suspending fluids. By considering a wide range of shear rate and interior-to-exterior fluid viscosity ratio, it is shown that the cell dynamics is often more complex than the well-known tank-treading, tumbling, and swinging motion and is characterized by an extreme variation of the cell shape. As a result, it is often difficult to clearly establish whether the cell is swinging or tumbling. Identifying such complex shape dynamics, termed here as “breathing” dynamics, is the focus of this article. During the breathing motion at moderate bending rigidity, the cell either completely aligns with the flow direction and the membrane folds inward, forming two cusps, or it undergoes large swinging motion while deep, craterlike dimples periodically emerge and disappear. At lower bending rigidity, the breathing motion occurs over a wider range of shear rates, and is often characterized by the emergence of a quad-concave shape. The effect of the breathing dynamics on the tank-treading-to-tumbling transition is illustrated by detailed phase diagrams which appear to be more complex and richer than those of vesicles. In a remarkable departure from the vesicle dynamics, and from the classical theory of nondeformable cells, we find that there exists a critical viscosity ratio below which the transition is independent of the viscosity ratio, and dependent on shear rate only. Further, unlike the reduced-order models, the present simulations do not predict any intermittent dynamics of the red blood cells.

Yazdani, Alireza Z. K.; Bagchi, Prosenjit

2011-08-01

62

Phase diagram of sustained wave fronts opposing the flow in disordered porous media

Using lattice Boltzmann simulations, we analyze the different regimes of propagation of an autocatalytic reaction front in heterogenous porous media. The heterogeneities of the porous medium are characterized by the standard deviation of its log-normal distribution of permeability and its correlation length. We focus on the situation where chemical reaction and flow field act in opposite directions. In agreement with previous experiments we observe upstream, downstream fronts as well as static, frozen ones over a range of flow velocity which depends drastically on the heterogeneities of the flow field. The transition between the static regime and the downstream one account for large enough low-velocity zones, whereas the transition from static to upstream regime is found to be given by a kind of percolation path.

Saha, Sandeep; Atis, Severine; Salin, Dominique; Talon, Laurent

2013-02-01

63

Prolog Visualization System Using Logichart Diagrams

We have developed a Prolog visualization system that is intended to support Prolog programming education. The system uses Logichart diagrams to visualize Prolog programs. The Logichart diagram is designed to visualize the Prolog execution flow intelligibly and to enable users to easily correlate the Prolog clauses with its parts. The system has the following functions. (1) It visually traces Prolog execution (goal calling, success, and failure) on the Logichart diagram. (2) Dynamic change in a Prolog program by calling extra-logical predicates, such as `assertz' and `retract', is visualized in real time. (3) Variable substitution processes are displayed in a text widget in real time.

Adachi, Yoshihiro

2009-01-01

64

Chemical reactions and processes under flow conditions

Pharmaceutical and fine chemical products are typically synthesised batchwise which is an anomaly since batch processes have a series of practical and economical disadvantages. On the contrary, flow continuous processes present a series of advantages leading to new ways to synthesise chemical products. Flow processes - * enable control reaction parameters more precisely (temperature, residence time, amount of reagents and solvent etc.), leading to better reproducibility, safer and more reliable processes * can be performed more advantageously using immobilized reagents or catalysts * improve t

Luis, Santiago V; Clark, James H

2009-01-01

65

International Nuclear Information System (INIS)

The comprehensive survey and estimation flow diagram for the Preliminary Investigation (PI) was constructed by simulating the PI, and the validity of the consideration which is set up in this study was examined. Also, the element technologies were developed for the efficient and upgraded PI. The basic concept of the PI such as how to select the area for PI was set up and proposed as a postulate for this study. By simulating the PI, the survey and estimation flow diagram from the view point of engineering and geological long stability were constructed, then the comprehensive survey and estimation flow diagram was integrated by considering the spatiotemporal relationship of both flow diagrams. The PI in the various geological conditions was simulated and it is examined whether we can collect enough data to check the consideration. This resulted that most data to check the consideration could be collected through the PI. Among the existing technologies making up the PI, some technologies extracted for the efficient and upgraded PI were developed. (author)

2011-03-01

66

Czech Academy of Sciences Publication Activity Database

BORM DiagramsKód oboru RIV: IN - Informatika http://library.utia.cas.cz/separaty/2012/ZOI/papik-efficient transformation of use case main success scenario steps into bussiness object relation (borm) diagrams for effective bussiness process requirement analysis.pdf

Podaras, A.; Moravec, J.; Papík, Martin

67

ROLE OF UML SEQUENCE DIAGRAM CONSTRUCTS IN OBJECT LIFECYCLE CONCEPT

Digital Repository Infrastructure Vision for European Research (DRIVER)

When modeling systems and using UML concepts, a real system can be viewed in several ways. The RUP (Rational Unified Process) defines the "4 + 1 view": 1. Logical view (class diagram (CD), object diagram (OD), sequence diagram (SD), collaboration diagram (COD), state chart diagram (SCD), activity diagram (AD)), 2.Process view (use case diagram, CD, OD, SD, COD, SCD, AD), 3. Development view (package diagram, component diagram), 4. Physical view (deployment diagram), and 5. Use case view (use ...

Miroslav Grgec; Robert Mužar

2007-01-01

68

Fluid flow processes at basin scale

Digital Repository Infrastructure Vision for European Research (DRIVER)

[EN] Subsurface fluid flow plays a significant role in many geologic processes and is increasingly being studied in the scale of sedimentary basins and geologic time perspective. Many economic resources such as petroleum and mineral deposits are products of basin scale fluid flow operating over large periods of time. Such ancient flow systems can be studied through analysis of diagenetic alterations and fluid inclusions to constrain physical and chemical conditions of fluids and rocks during ...

Trave?, A.; Bitzer, K.; Carmona, J. Mari?a

2001-01-01

69

Fluid flow processes at basin scale

Digital Repository Infrastructure Vision for European Research (DRIVER)

S u b s u r face fluid flow plays a significant role in many geologic processes and is increasingly being studied in the scale of sedimentary basins and geologic time perspective. Many economic resources such as petroleum and mineral deposits are products of basin scale fluid flow operating over large periods of time. Such ancient flow systems can be studied through analysis of diagenetic alterations and fluid inclusions to constrain physical and chemical conditions of fluids and rocks during...

Bitzer, Klaus; Trave? I Herrero, Anna; Carmona Pe?rez, Jose? Ma

2001-01-01

70

Directory of Open Access Journals (Sweden)

Full Text Available Flange tube, Glass shell, Lead in Wire (LIW, Filament (Coil and Cap are the most important raw materials in case of Lamp Production Process. Manufacturing processes tend to produce operational wastages due to various reasons, which can be reduced by identifying and eliminating those reasons. It has been a very challenging engineering problem particularly in a multistage manufacturing, where maximum number of processes and activities are performed. With the help of Pareto diagrams, which are mostly used to identify critical areas, the manufacturing process defects in the each stage of the production belt have been prioritized by arranging them in decreasing order of importance. Then cause and effect diagram is being applied to explore possible causes/factors of defects and to determine the causes/factors, which has the greatest effect.

**Key words:** Lamp production process; Multistage manufacturing; Pareto diagrams; Production belt; Cause and effect diagram

Nafis Ahmad

2011-09-01

71

We critically discuss the concept of ``synchronized flow'' from a historical, empirical, and theoretical perspective. Problems related to the measurement of vehicle data are highlighted, and questionable interpretations are identified. Moreover, we propose a quantitative and consistent theory of the empirical findings based on a phase diagram of congested traffic states, which is universal for all conventional traffic models having the same instability diagram and a fundamental diagram. New empirical and simulation data supporting this approach are presented as well. We also give a short overview of the various phenomena observed in panicking pedestrian crowds relevant from the point of evacuation of buildings, ships, and stadia. Some of these can be applied to the optimization of production processes, e.g. the ``slower-is-faster effect''.

Helbing, D; Fasold, D; Treiber, M; Vicsek, T

2002-01-01

72

In this number sorting activity students must use a Carroll Diagram to determine which two categories each number fits into. This activity can be completed in pairs or groups on printable versions or it can be completed as a whole class using the interactive white board (IWB). Included with this resource are printable versions of the Carroll Diagrams, guiding questions, extension and support suggestions, and a link to more challenging "More Carroll Diagrams".

Team, Nrich

2012-01-01

73

Digital Repository Infrastructure Vision for European Research (DRIVER)

Based on comprehensive measurements of plankton abundance and production, quantitative carbon flow diagrams were established for the pelagic community of a large lake (L. Constance) for ten successive time intervals during the seasonal course of 1987. Using reasonable diet compositions and parameters (e.g. trophic transfer efficiencies in the range of l0-35%), mass-balance conditions could be fulfilled for individual compartments and the entire food web, provided that ciliate growth rates use...

1994-01-01

74

A Feynman Diagram Analyser DIANA

Digital Repository Infrastructure Vision for European Research (DRIVER)

A C-program DIANA (DIagram ANAlyser) for the automatic Feynman diagram evaluation is presented. It consists of two parts: the analyzer of diagrams and the interpreter of a special text manipulating language. This language is used to create a source code for analytical or numerical evaluations and to keep the control of the process in general.

Tentyukov, M.; Fleischer, J.

1999-01-01

75

Fluid Flow Properties of WAG Injection Processes

Digital Repository Infrastructure Vision for European Research (DRIVER)

Immiscible water-alternating-gas (IWAG) experiments performed on equilibrated fluids are summarised together with the corresponding two-phase gas-oil and water-oil displacements. Experimental studies at reservoir condition and also mechanistic experiments over many years have shown accelerated oil production and higher core flood oil recovery as a result of three-phase flow. The three-phase effects that are included and analysed are; trapped gas, and mobility for secondary processes (ex. wate...

Dale, Elisabeth Iren; Skauge, Arne

2008-01-01

76

Anisotropic Young diagrams and infinite-dimensional diffusion processes with the Jack parameter

We construct a family of Markov processes with continuous sample trajectories on an infinite-dimensional space, the Thoma simplex. The family depends on three continuous parameters, one of which, the Jack parameter, is similar to the beta parameter in random matrix theory. The processes arise in a scaling limit transition from certain finite Markov chains, the so called up-down chains on the Young graph with the Jack edge multiplicities. Each of the limit Markov processes is ergodic and its stationary distribution is a symmetrizing measure. The infinitesimal generators of the processes are explicitly computed; viewed as selfadjoint operators in the L^2 spaces over the symmetrizing measures, the generators have purely discrete spectrum which is explicitly described. For the special value 1 of the Jack parameter, the limit Markov processes coincide with those of the recent work by Borodin and the author (Prob. Theory Rel. Fields 144 (2009), 281--318; arXiv:0810.3751). In the limit as the Jack parameter goes to ...

Olshanski, Grigori

2009-01-01

77

Patient flow scorecards capture complexity in the patient flow process.

To get a larger, more holistic view of the patient flow process, a multidisciplinary improvement team at Children's Hospital of Philadelphia (CHOP) developed a five-domain patient flow scorecard. Each domain has several weighted sub-metrics that add up to 20 points, so the maximum number of points in the composite score is 100. Improvement team leaders say the approach has helped them home in on specific reasons for hold-ups so that resources can be focused in the most effective way. The "ED and ED-to-inpatient transition" domain includes eight sub-metrics that cover five specific time intervals, the leave-without-being-seen (LWBS) rate, and two adjustment measures that are used to account for high volumes and high admission rates from the ED. The other domains cover bed management, the discharge process, room turnover and environmental services, and scheduling and utilization. Administrators say it is important to establish metrics that can be captured easily along with entry points that tie in with workflows. PMID:24968570

2014-07-01

78

Multi-Particle Processes in the Standard Model without Feynman Diagram

International Nuclear Information System (INIS)

A method to efficiently compute, in a automatic way, helicity amplitudes for arbitrary scattering processes at leading order in the Standard Model is presented. The scattering amplitude is evaluated recursively through a set of Dyson-Schwinger equations. The computational cost of this algorithm grows asymptotically as 3n, where n is the number of particles involved in the process, compared to n! in the traditional Feynman graphs approach. Unitary gauge is used and mass effects are available as well. Additionally, the color and helicity structures are appropriately transformed so the usual summation is replaced by Monte Carlo techniques. Some results related to the production of vector bosons and the Higgs boson in association with jets are also presented. (author)

2005-11-01

79

International Nuclear Information System (INIS)

Scenario development is a key component of the performance assessment (PA) process for radioactive waste disposal, the primary objective being to ensure that all relevant factors associated with the future evolution of the repository system are properly considered in PA. As part of scenario development, a list of features, events and processes (FEPs) are identified and assembled, representing the Process System, with interactions/influences between FEPs incorporated in a Process Influence Diagram (PID). This report documents the technical work conducted between 1997 and the end of 1999 under the Systems Studies Project. The overall objective of this project has been the construction of a PID for the SFR-1 repository (final repository for reactor waste), this PID being the first stage in the identification of scenarios to describe future evolution of this repository. The PIDs discussed in this report have been created using two software applications: existing commercial software (Business Modeller, Infotool AB. Stockholm, Sweden) and, more recently, a newly developed software tool SPARTA (Enviros QuantiSci, Henley, U.K.). Although the focus of this report is on the application of SPARTA to PID development, it is important to document the work carried out prior to SPARTA being available, in order to provide a complete record of the entire SFR-1 PID development effort as well as preserving the context of the multi-year project. Following a description of the different disposal sections of the SFR-1 and the various near-field barriers, the sequential development (i.e. near-field of Silo, BMA, BLA, BTF sections; far-field; integrated near-field + far-field) of the PID for SFR-1 repository system using Business Modeller is described. Owing to the complexity of the repository, in terms of number of both different disposal sections (Silo, BLA, BMA, BTF) and barriers associated with each section, the two-dimensional (2D) PID created for SFR-1 using Business Modeller is visually complex and potentially difficult to interpret. Primarily for this reason, the need for an alternative approach was recognised in 1996 and the decision was taken to develop new software for this purpose. Following a consensus on the specific requirements of the new software, a first version of SPARTA became available towards the end of 1998, with subsequent versions being released during 1999. SPARTA is used to generate a three-dimensional (3D) PID consisting of a series of layers, each underlying layer providing additional (more detailed) information about the Process System. The uppermost layer or diagram may be regarded as a top-level view of the repository system (near-field, far-field and biosphere). In the PID developed for SKI, underlying layers or diagrams often have some physical meaning, e.g. sections of the repository (Silo, BLA, BMA, BTF sections, repository zone), or barriers of a section (e.g. for the Silo - backfill, reinforced shell, porous grout or mortar, waste package). Other layers contain groups of related FEPs, e.g. geochemical FEPs. A total of 95 drawings, typically consisting of 6-8 FEPs each, describe the SFR-1 repository system. The two PIDs developed for the SFR-1 repository provide different representations of the near-field and far-field of the repository system; the first PID being two-dimensional and the later one three-dimensional. Despite the different approaches, the primary objective of constructing each PID has been the same: firstly, to ensure that all FEPs relevant to the future evolution of the repository system are considered, and secondly, that all 'essential' influences are identified so that they may be incorporated in the subsequent modelling of the system's evolution

2001-01-01

80

Energy Technology Data Exchange (ETDEWEB)

Scenario development is a key component of the performance assessment (PA) process for radioactive waste disposal, the primary objective being to ensure that all relevant factors associated with the future evolution of the repository system are properly considered in PA. As part of scenario development, a list of features, events and processes (FEPs) are identified and assembled, representing the Process System, with interactions/influences between FEPs incorporated in a Process Influence Diagram (PID). This report documents the technical work conducted between 1997 and the end of 1999 under the Systems Studies Project. The overall objective of this project has been the construction of a PID for the SFR-1 repository (final repository for reactor waste), this PID being the first stage in the identification of scenarios to describe future evolution of this repository. The PIDs discussed in this report have been created using two software applications: existing commercial software (Business Modeller, Infotool AB. Stockholm, Sweden) and, more recently, a newly developed software tool SPARTA (Enviros QuantiSci, Henley, U.K.). Although the focus of this report is on the application of SPARTA to PID development, it is important to document the work carried out prior to SPARTA being available, in order to provide a complete record of the entire SFR-1 PID development effort as well as preserving the context of the multi-year project. Following a description of the different disposal sections of the SFR-1 and the various near-field barriers, the sequential development (i.e. near-field of Silo, BMA, BLA, BTF sections; far-field; integrated near-field + far-field) of the PID for SFR-1 repository system using Business Modeller is described. Owing to the complexity of the repository, in terms of number of both different disposal sections (Silo, BLA, BMA, BTF) and barriers associated with each section, the two-dimensional (2D) PID created for SFR-1 using Business Modeller is visually complex and potentially difficult to interpret. Primarily for this reason, the need for an alternative approach was recognised in 1996 and the decision was taken to develop new software for this purpose. Following a consensus on the specific requirements of the new software, a first version of SPARTA became available towards the end of 1998, with subsequent versions being released during 1999. SPARTA is used to generate a three-dimensional (3D) PID consisting of a series of layers, each underlying layer providing additional (more detailed) information about the Process System. The uppermost layer or diagram may be regarded as a top-level view of the repository system (near-field, far-field and biosphere). In the PID developed for SKI, underlying layers or diagrams often have some physical meaning, e.g. sections of the repository (Silo, BLA, BMA, BTF sections, repository zone), or barriers of a section (e.g. for the Silo - backfill, reinforced shell, porous grout or mortar, waste package). Other layers contain groups of related FEPs, e.g. geochemical FEPs. A total of 95 drawings, typically consisting of 6-8 FEPs each, describe the SFR-1 repository system. The two PIDs developed for the SFR-1 repository provide different representations of the near-field and far-field of the repository system; the first PID being two-dimensional and the later one three-dimensional. Despite the different approaches, the primary objective of constructing each PID has been the same: firstly, to ensure that all FEPs relevant to the future evolution of the repository system are considered, and secondly, that all 'essential' influences are identified so that they may be incorporated in the subsequent modelling of the system's evolution.

Stenhouse, M.J. [Monitor Scientific, LLC, Denver, CO (United States); Miller, W.M.; Chapman, N.A. [QuantiSci Ltd., Melton Mowbray (United Kingdom)

2001-05-01

81

International Nuclear Information System (INIS)

The microstructures attendant to specific peak strains along the strain axis of the stress-strain diagram for type 304-stainless steel and nickel have been examined and compared by transmission electron microscopy from epsilon = 0.05% to epsilon 55% in the former and from epsilon = 0.05% to epsilon = 35% in the latter. The onset of flow is characterised by the emission of dislocations from grain boundary ledge sources which form emission profiles resembling dislocation pile-ups in the stainless steel, and a random distribution of dislocations with evidence for very short emission profiles near the grain boundaries in nickel. The results are presented and discussed. (author)

1982-01-01

82

Digital image processing in flow visualization

International Nuclear Information System (INIS)

Flow visualization results from the interactions between light and matter. Classical methods such as shadowgraphy, schlieren photography, and interferometry visualize variation in the index of refraction induced by changes in density, pressure, or temperature. Nonuniformities of these physical observables modify the phase of optical waves, rendered visible by free-space propagation (shadowgraphy), optical processing in the back focal plane of a lens (schlieren photography), or interference with a reference wave (interferometry). The classical methods visualize variations of the index of refraction or spatial derivatives thereof integrated along the light path through the fluid. Three-dimensional space is projected onto a plane with the corresponding reduction in degrees of freedom. Except for axial symmetric or two-dimensional flows, spatial structures cannot be recovered from a single image

1988-01-01

83

Process Flow and Functional Analysis of the Iter Cryogenic System

The ITER cryogenic system is presently under design by a large international collaboration. It will start commissioning at Cadarache, south of France in 2015. The system is designed to provide an equivalent refrigeration capacity of 65 kW at 4.5 K for the superconducting magnet and 1300 kW at 80 K for the cryoplant pre-cooling stages and the Cryostat Thermal Shields (CTS). The cryoplant consists of three 4.5 K refrigerators and two 80 K helium loops coupled with two LN2 modules. Two 4.5 K modules are dedicated to the magnet system and a small one is devoted to the cryopumps and Pellet Injection System. One Interconnection box interfaces the cryoplant and a complex cryodistribution system which includes 5 Auxiliary Cold Boxes dedicated to each cryogenic subsystem. The ITER cryogenic system will have to cope with various normal and abnormal operational modes including superconducting magnets quench recovery and fast energy discharge. We will present the general Process Flow Diagram of the cryoplant and cryodistribution system and the operation requirements. The functional analysis of the cryogenic system will be performed leading to a proposal of the cryogenic control system architecture. The instrumentation and control requirements will also be outlined.

Henry, D.; Chalifour, M.; Forgeas, A.; Kalinin, V.; Monneret, E.; Serio, L.; Vincent, G.; Voigt, T.

2010-04-01

84

Chaos and bifurcation in dynamical evolution process of traffic assignment with flow 'mutation'

International Nuclear Information System (INIS)

Considering such a fact that the traffic demands freshly entering a network do not have perfect information about traffic condition and may then choose routes randomly, in this paper, we present an improved network traffic flow evolution model. The model's properties and fixed points are investigated. Numerical results obtained from a grid network show that the system can converge to one or more fixed points without requiring of positive route flows at initial time, and can be used to approximately simulate the process of realizing user equilibrium state. It is found that oscillations and such apparently irregular behaviors as chaos occur when the model parameter representing intensity of adjusting route flow and OD demand exceeds some values. Bifurcation diagrams of some route flows and OD demands with respect to this model parameter are presented.

2009-08-15

85

The perceptual flow of phonetic feature processing

DEFF Research Database (Denmark)

How does the brain process spoken language? It is our thesis that word intelligibility and consonant identification are insufficient by themselves to model how the speech signal is decoded - a finer-grained approach is required. In this study, listeners identified 11 different Danish consonants spoken in a Consonant + Vowel + [l] environment. Each syllable was processed so that only a portion of the original audio spectrum was present. Three-quarter-octave bands of speech, centered at 750, 1500, and 3000 Hz, were presented individually and in combination with each other. The conditional, posterior probabilities associated with phonetic-feature decoding were computed from confusion matrices in order to deduce the temporal flow of phonetic processing. Decoding the feature, Manner-of-Articulation, depends on accurate decoding of the feature Voicing (but not vice-versa), and decoding Place-of-Articulation requires precise decoding of Manner (but not the converse). From these data, we conclude that Voicing is processed prior to Manner-of-Articulation, and that Manner is decoded prior to Place-of-Articulation. Voicing and Manner cues are often correctly decoded in conditions where Place is not. This asymmetric pattern of feature decoding may provide extra-segmental information of utility for speech processing, particularly in adverse listening conditions.

Greenberg, Steven; Christiansen, Thomas Ulrich

2008-01-01

86

Digital Repository Infrastructure Vision for European Research (DRIVER)

Flange tube, Glass shell, Lead in Wire (LIW), Filament (Coil) and Cap are the most important raw materials in case of Lamp Production Process. Manufacturing processes tend to produce operational wastages due to various reasons, which can be reduced by identifying and eliminating those reasons. It has been a very challenging engineering problem particularly in a multistage manufacturing, where maximum number of processes and activities are performed. With the help of Pareto diagrams, which are...

2011-01-01

87

Stochastic diagrams and Feynman diagrams

International Nuclear Information System (INIS)

We study the relationship between ordinary perturbation theory and perturbation theory obtained from stochastic quantization. We give a simple proof that, except in gauge theories, the several stochastic diagrams of a given topology are together equivalent to the corresponding Feynman diagram. Our analysis is presented in Minkowski space, but most of it may readily be adapted to euclidean space. The field propagator may be a non-diagonal matrix, such as is the case in real-time thermal field theory. We present a new version of the Langevin equation which directly reproduces the usual axial-gauge perturbation theory. Otherwise, we find that for gauge theories the relationship between ordinary and stochastic perturbation theory is not simple, and we present a recursive method of reconstructing Feynman diagrams from stochastic diagrams, without the need explicitly to introduce ghost fields. We consider both the original Parisi-Wu version of the Langevin equation, and Zwanziger's modified version with its stochastic gauge-fixing term. (orig.)

1985-10-28

88

The RiverFish Approach to Business Process Modeling: Linking Business Steps to Control-Flow Patterns

Despite the recent advances in the area of Business Process Management (BPM), today’s business processes have largely been implemented without clearly defined conceptual modeling. This results in growing difficulties for identification, maintenance, and reuse of rules, processes, and control-flow patterns. To mitigate these problems in future implementations, we propose a new approach to business process modeling using conceptual schemas, which represent hierarchies of concepts for rules and processes shared among collaborating information systems. This methodology bridges the gap between conceptual model description and identification of actual control-flow patterns for workflow implementation. We identify modeling guidelines that are characterized by clear phase separation, step-by-step execution, and process building through diagrams and tables. The separation of business process modeling in seven mutually exclusive phases clearly delimits information technology from business expertise. The sequential execution of these phases leads to the step-by-step creation of complex control-flow graphs. The process model is refined through intuitive table and diagram generation in each phase. Not only does the rigorous application of our modeling framework minimize the impact of rule and process changes, but it also facilitates the identification and maintenance of control-flow patterns in BPM-based information system architectures.

Zuliane, Devanir; Oikawa, Marcio K.; Malkowski, Simon; Alcazar, José Perez; Ferreira, João Eduardo

89

We study the steady-state behavior of a driven non-equilibrium lattice gas of hard-core particles with next-nearest-neighbor interaction. We calculate the exact stationary distribution of the periodic system and for a particular line in the phase diagram of the system with open boundaries where particles can enter and leave the system. For repulsive interactions the dynamics can be interpreted as a two-speed model for traffic flow. The exact stationary distribution of the periodic continuous-time system turns out to coincide with that of the asymmetric exclusion process (ASEP) with discrete-time parallel update. However, unlike in the (single-speed) ASEP, the exact flow diagram for the two-speed model resembles in some important features the flow diagram of real traffic. The stationary phase diagram of the open system obtained from Monte Carlo simulations can be understood in terms of a shock moving through the system and an overfeeding effect at the boundaries, thus confirming theoretical predictions of a re...

Antal, T

2000-01-01

90

Human Factors Operability Timeline Analysis to Improve the Processing Flow of the Orion Spacecraft

This slide presentation reviews the use of Human factors and timeline analysis to have a more efficient and effective processing flow. The solution involved developing a written timeline of events that included each activity within each functional flow block. Each activity had computer animation videos and pictures of the people involved and the hardware. The Human Factors Engineering Analysis Tool (HFEAT) was improved by modifying it to include the timeline of events. The HFEAT was used to define the human factors requirements and design solutions were developed for these requirements. An example of a functional flow block diagram is shown, and a view from one of the animations (i.e., short stack pallet) is shown and explained.

Stambolian, Damon B.; Schlierf, Roland; Miller, Darcy; Posada, Juan; Haddock, Mike; Haddad, Mike; Tran, Donald; Henderon, Gena; Barth, Tim

2011-01-01

91

Control Flow Pattern Recognition for BPMN Process Models

Digital Repository Infrastructure Vision for European Research (DRIVER)

Business process modeling is the first and the most important task in business process management (BPM). Business process models are implicitly composed of a set of control flow patterns, such as the Parallel Split, Synchronization, Exclusive Choice, and Simple Merge, etc. Several studies have proposed the concepts and definitions of control flow patterns. But, few analyzed the structure of process models to identify the constituent control flow patterns. This research proposes a three-phased...

2013-01-01

92

Hanford Site Treated Effluent Disposal Facility process flow sheet

International Nuclear Information System (INIS)

This report presents a novel method of using precipitation, destruction and recycle factors to prepare a process flow sheet. The 300 Area Treated Effluent Disposal Facility (TEDF) will treat process sewer waste water from the 300 Area of the Hanford Site, located near Richland, Washington, and discharge a permittable effluent flow into the Columbia River. When completed and operating, the TEDF effluent water flow will meet or exceed water quality standards for the 300 Area process sewer effluents. A preliminary safety analysis document (PSAD), a preconstruction requirement, needed a process flow sheet detailing the concentrations of radionuclides, inorganics and organics throughout the process, including the effluents, and providing estimates of stream flow quantities, activities, composition, and properties (i.e. temperature, pressure, specific gravity, pH and heat transfer rates). As the facility begins to operate, data from process samples can be used to provide better estimates of the factors, the factors can be entered into the flow sheet and the flow sheet will estimate more accurate steady state concentrations for the components. This report shows how the factors were developed and how they were used in developing a flow sheet to estimate component concentrations for the process flows. The report concludes with how TEDF sample data can improve the ability of the flow sheet to accurately predict concentrations of components in the process

1993-06-20

93

Process flow measurement based on tracer techniques

International Nuclear Information System (INIS)

Flow measurement methods based on the tracer techniques are the transit time method as well as methods based on tracer dilution. These methods can be applied to the on-site calibration of flowmeters and to measuring the flowrate where no flowmeter is installed. The accuracy of the tracer methods depends on the prevailing measuring conditions. In this report the accuracy of the transit time method under field conditions is estimated to be 1-2% on the 99,7% confidence level. The accuracy of the isotope dilution method is estimated as slightly better, namely about 0.5% at its best. An even better accuracy, about 0.2%, could be achieved by developing the method and the measuring equipment. Tests were carried out with the transit time method for water and steam flow. While measuring water flow the effect of different measuring parameters upon the repeatability of the method were looked into. Such were the number of the detectors and the distance between the measuring points. Different means of tracer injection were tested, as well. These had less effect than expected. The accuracies achieved in steam flow measurements were of the same order of magnitude as in water flow measurements. The tracers used were 137mBa for water flow and 41Ar for steam flow measurements

1988-01-01

94

Ultrasonic flow meter proves its worth on vacuum tower bottoms; Process flow measurement

Energy Technology Data Exchange (ETDEWEB)

Process conditions at the bottom of vacuum distillation towers make flow measurement challenging. In this case study, a clamp-on ultrasonic flow meter proves more reliable than the traditional orifice plate. (Author)

Wetzel, Rainer

2009-07-01

95

A Stability Diagram for Dense Suspensions of Model Colloidal Al2O3-Particles in Shear Flow

Digital Repository Infrastructure Vision for European Research (DRIVER)

In Al2O3 suspensions, depending on the experimental conditions very different microstructures can be found, comprising fluid like suspensions, a repulsive structure, and a clustered microstructure. For technical processing in ceramics, the knowledge of the microstructure is of importance, since it essentially determines the stability of a workpiece to be produced. To enlighten this topic, we investigate these suspensions under shear by means of simulations. We observe cluste...

Hecht, Martin; Harting, Jens; Herrmann, Hans J.

2006-01-01

96

Computation of Reacting Flows in Combustion Processes

The objective of this research is to develop an efficient numerical algorithm with unstructured grids for the computation of three-dimensional chemical reacting flows that are known to occur in combustion components of propulsion systems. During the grant period (1996 to 1999), two companion codes have been developed and various numerical and physical models were implemented into the two codes.

Keith, Theo G., Jr.; Chen, K.-H.

2001-01-01

97

Digital signal processing of ultrasonic signals for blood flow measurement.

This paper describes the application of advanced digital signal processing techniques in a noninvasive ultrasonic Doppler flowmeter used to measure extracorporeal blood flow during open heart surgery. The use of ultrasound to determine blood flow rates started in the 1950's with much of this work focused on measurement of blood flow in a patient by a variety of means, both invasive and noninvasive. Although the use of ultrasonics to measure blood flow is not in itself a new concept, the application of advanced digital signal processing techniques in the system being described has resulted in a unique product for accurate and reliable blood flow measurements. The flowmeter system is intended for use with a centrifugal blood pump and will measure blood flow in the flexible tubing used during surgery to an accuracy of better than +/- 10%. This paper describes the development and implementation of the digital flowmeter and its application to flow measurement. PMID:2663094

Smith, D R; Christmann, H A; Weaver, B L; Betten, W R; Nazarian, R A

1989-01-01

98

Control Flow Pattern Recognition for BPMN Process Models

Directory of Open Access Journals (Sweden)

Full Text Available Business process modeling is the first and the most important task in business process management (BPM. Business process models are implicitly composed of a set of control flow patterns, such as the Parallel Split, Synchronization, Exclusive Choice, and Simple Merge, etc. Several studies have proposed the concepts and definitions of control flow patterns. But, few analyzed the structure of process models to identify the constituent control flow patterns. This research proposes a three-phased framework to recognize the constituent control flow patterns and their interrelationship for a Business Process Modeling Notation (BPMN process model. The conceptual phase first describes the conceptual process for identifying the control flow patterns from a process model. The design phase then develops the detailed procedure and methods based on the proposed conceptual process to recognize the control flow patterns for a BPMN process model. Finally, the implementation phase carries out the proposed procedure and methods by developing a workflow pattern representation system for BPMN process models.

Yeh-Chun Juan

2013-06-01

99

Flow-based analyses of metal deformation processes: An overview

Flow based analysis of metal deformation processing provides a new design perspective to assess optimum process variables and workpiece material behavior. Components of flow based analysis include finite element computation of process mechanics, realistic constitutive equations for workpiece plastic flow, and analytical models for workability during processing. Process requirements such as press loads and maximum limiting strains are determined by process variables such as temperature and performance design. In principle the strain history of each element in the workpiece can be determined and used to predict the distribution of properties within the product. The material characterization necessary to implement flow based analysis is illustrated for the hot forging behavior of the high strength aerospace titanium alloy, Ti-6242.

Thomas, J. F., Jr.

1984-09-01

100

Separation of hydrogen isotopes by a flowing bed process

International Nuclear Information System (INIS)

Results of an experimental study on a flowing bed process for continuous hydrogen isotope separation are presented. Separation performance was low with a 25% by weight palladium on alumina adsorbent, resulting in a high tritium inventory. In addition, significant breakdown of the solid adsorbent occurred as it recirculated through the process equipment and the product streams were contaminated by the adsorbent carrier gas. Due to these problems, this flowing bed process is predicted to be uneconomic for a full scale plant

1987-01-01

101

Flow measurements in semiconductor processing; New advances in measurement technology

Gas flow measurement, control, and distribution are an integral part in meeting present and future semiconductor processing requirements (1). Changes in processing and environmental concerns have put additional pressure not only on accurate measurement of the gas flow, but also in reducing flows. To address the need for more accurate metering of gas flows, NIST has developed primary flow standards which have uncertainties of 0.1% of reading or better over the flow range of 10-9 mol/s to 10-3 mol/s (0.001 sccm to 1000 sccm). These standards have been used to test NIST-designed high repeatability flow transfer standards (2) which can be used to document and improve flow measurements in the semiconductor industry (3). In particular two flowmeters have been developed at NIST; the first is a pressure-based flow sensor and the second a Doppler-shift flowmeter, both of which can be used for in-situ calibration of thermal mass flow controllers or for direct metering of process gases.

Tison, S. A.; Calabrese, A. M.

1998-11-01

102

Simulator for concurrent processing data flow architectures

A software simulator capability of simulating execution of an algorithm graph on a given system under the Algorithm to Architecture Mapping Model (ATAMM) rules is presented. ATAMM is capable of modeling the execution of large-grained algorithms on distributed data flow architectures. Investigating the behavior and determining the performance of an ATAMM based system requires the aid of software tools. The ATAMM Simulator presented is capable of determining the performance of a system without having to build a hardware prototype. Case studies are performed on four algorithms to demonstrate the capabilities of the ATAMM Simulator. Simulated results are shown to be comparable to the experimental results of the Advanced Development Model System.

Malekpour, Mahyar R.; Stoughton, John W.; Mielke, Roland R.

1992-01-01

103

Condensation processes in compressible flow of moist air around airfoils

Compressible flow of moist air with various condensation processes around thin airfoils is investigated. This study is based on an extended transonic small-disturbance model by Rusak and Lee^1 which includes the effects of heat addition to the flow due to condensation. Two possible limit types of condensation processes are considered. In the nonequilibrium and homogeneous process, which typically occurs in moist air with purified water vapor, the condensate mass fraction is calculated according to the classical nucleation and droplet growth rate models of Wegener and Mack^2 and Hill.^3 In the equilibrium and heterogeneous process, which usually happens in moist air with many foreign nuclei, the condensate mass fraction is calculated by assuming that the process is isentropic. The flow and condensation equations are solved numerically by iterative computations. Under the same upstream flow conditions, the results of the flow structure, the field of condensate, and the pressure distribution on airfoils' surfaces are described for the two condensation processes. It is found that the flow characteristics, such as the position and strength of shock waves and the airfoils' pressure drag, are different in the two cases. Yet, in each case, heat addition as a result of condensation causes significant changes in the flow behavior and affects the aerodynamic performance of airfoils. 1. Rusak and Lee, 1999, J. Fluid Mechanics, 403, 173-199. 2. Wegener and Mack, 1958, Adv. App. Mech., 5, 307-447. 3. Hill, 1966, J. Fluid Mechanics, 25, 3, 593-620.

Lee, J.-C.; Rusak, Z.

2000-11-01

104

Breviz: Visualizing Spreadsheets using Dataflow Diagrams

Spreadsheets are used extensively in industry, often for business critical purposes. In previous work we have analyzed the information needs of spreadsheet professionals and addressed their need for support with the transition of a spreadsheet to a colleague with the generation of data flow diagrams. In this paper we describe the application of these data flow diagrams for the purpose of understanding a spreadsheet with three example cases. We furthermore suggest an additional application of the data flow diagrams: the assessment of the quality of the spreadsheet's design.

Hermans, Felienne; van Deursen, Arie

2011-01-01

105

Stochastic flows with interaction and measure-valued processes

Directory of Open Access Journals (Sweden)

Full Text Available We consider the new class of the Markov measure-valued stochastic processes with constant mass. We give the construction of such processes with the family of the probabilities which describe the motion of single particles. We also consider examples related to stochastic flows with the interactions and the local times for such processes.

Andrey A. Dorogovtsev

2003-11-01

106

Documentation of a Conduit Flow Process (CFP) for MODFLOW-2005

This report documents the Conduit Flow Process (CFP) for the modular finite-difference ground-water flow model, MODFLOW-2005. The CFP has the ability to simulate turbulent ground-water flow conditions by: (1) coupling the traditional ground-water flow equation with formulations for a discrete network of cylindrical pipes (Mode 1), (2) inserting a high-conductivity flow layer that can switch between laminar and turbulent flow (Mode 2), or (3) simultaneously coupling a discrete pipe network while inserting a high-conductivity flow layer that can switch between laminar and turbulent flow (Mode 3). Conduit flow pipes (Mode 1) may represent dissolution or biological burrowing features in carbonate aquifers, voids in fractured rock, and (or) lava tubes in basaltic aquifers and can be fully or partially saturated under laminar or turbulent flow conditions. Preferential flow layers (Mode 2) may represent: (1) a porous media where turbulent flow is suspected to occur under the observed hydraulic gradients; (2) a single secondary porosity subsurface feature, such as a well-defined laterally extensive underground cave; or (3) a horizontal preferential flow layer consisting of many interconnected voids. In this second case, the input data are effective parameters, such as a very high hydraulic conductivity, representing multiple features. Data preparation is more complex for CFP Mode 1 (CFPM1) than for CFP Mode 2 (CFPM2). Specifically for CFPM1, conduit pipe locations, lengths, diameters, tortuosity, internal roughness, critical Reynolds numbers (NRe), and exchange conductances are required. CFPM1, however, solves the pipe network equations in a matrix that is independent of the porous media equation matrix, which may mitigate numerical instability associated with solution of dual flow components within the same matrix. CFPM2 requires less hydraulic information and knowledge about the specific location and hydraulic properties of conduits, and turbulent flow is approximated by modifying horizontal conductances assembled by the Block-Centered Flow (BCF), Layer-Property Flow (LPF), or Hydrogeologic-Unit Flow Packages (HUF) of MODFLOW-2005. For both conduit flow pipes (CFPM1) and preferential flow layers (CFPM2), critical Reynolds numbers are used to determine if flow is laminar or turbulent. Due to conservation of momentum, flow in a laminar state tends to remain laminar and flow in a turbulent state tends to remain turbulent. This delayed transition between laminar and turbulent flow is introduced in the CFP, which provides an additional benefit of facilitating convergence of the computer algorithm during iterations of transient simulations. Specifically, the user can specify a higher critical Reynolds number to determine when laminar flow within a pipe converts to turbulent flow, and a lower critical Reynolds number for determining when a pipe with turbulent flow switches to laminar flow. With CFPM1, the Hagen-Poiseuille equation is used for laminar flow conditions and the Darcy-Weisbach equation is applied to turbulent flow conditions. With CFPM2, turbulent flow is approximated by reducing the laminar hydraulic conductivity by a nonlinear function of the Reynolds number, once the critical head difference is exceeded. This adjustment approximates the reductions in mean velocity under turbulent ground-water flow conditions.

Shoemaker, W. Barclay; Kuniansky, Eve L.; Birk, Steffen; Bauer, Sebastian; Swain, Eric D.

2007-01-01

107

Phase Diagrams for Traffics on the Crossroad

The traffic flows on two one-lane roads, crossing at a point, are studied on the basis of the local occupation probability method. The phase diagrams are constructed for the cases of various maximum car velocities. It has turned out that the phase diagrams consist essentailly of five regions.

Ishibashi, Yoshihiro; Fukui, Minoru

2001-09-01

108

A multi-phase flow model for electrospinning process

Directory of Open Access Journals (Sweden)

Full Text Available An electrospinning process is a multi-phase and multi-physicical process with flow, electric and magnetic fields coupled together. This paper deals with establishing a multi-phase model for numerical study and explains how to prepare for nanofibers and nanoporous materials. The model provides with a powerful tool to controlling over electrospinning parameters such as voltage, flow rate, and others.

Xu Lan

2013-01-01

109

Accurate, reliable control of process gases by mass flow controllers

Energy Technology Data Exchange (ETDEWEB)

The thermal mass flow controller, or MFC, has become an instrument of choice for the monitoring and controlling of process gas flow throughout the materials processing industry. These MFCs are used on CVD processes, etching tools, and furnaces and, within the semiconductor industry, are used on 70% of the processing tools. Reliability and accuracy are major concerns for the users of the MFCs. Calibration and characterization technologies for the development and implementation of mass flow devices are described. A test facility is available to industry and universities to test and develop gas floe sensors and controllers and evaluate their performance related to environmental effects, reliability, reproducibility, and accuracy. Additional work has been conducted in the area of accuracy. A gravimetric calibrator was invented that allows flow sensors to be calibrated in corrosive, reactive gases to an accuracy of 0.3% of reading, at least an order of magnitude better than previously possible. Although MFCs are typically specified with accuracies of 1% of full scale, MFCs may often be implemented with unwarranted confidence due to the conventional use of surrogate gas factors. Surrogate gas factors are corrections applied to process flow indications when an MFC has been calibrated on a laboratory-safe surrogate gas, but is actually used on a toxic, or corrosive process gas. Previous studies have indicated that the use of these factors may cause process flow errors of typically 10%, but possibly as great as 40% of full scale. This paper will present possible sources of error in MFC process gas flow monitoring and control, and will present an overview of corrective measures which may be implemented with MFC use to significantly reduce these sources of error.

Hardy, J.; McKnight, T.

1997-02-01

110

Recent Results in Ring-Diagram Analysis

The ring-diagram technique was developed by Frank Hill 25 years ago and matured quickly during the late 1990s. It is nowadays one of the most commonly used techniques in local helioseismology. The method consists in the power spectral analysis of solar acoustic oscillations on small regions (2° to 30°) of the solar surface. The power spectrum resembles a set of trumpets nested inside each other and for a given frequency, it looks like a ring, hence the technique's name. It provides information on the horizontal flow field and thermodynamic structure in the layers immediately below the photosphere. With data regularly provided by MDI, GONG, and more recently HMI, many important results have been achieved. In recently years, these results include estimations of the meridional circulation and its evolution with solar cycle; flows associated with active regions, as well as, flow divergence and vorticity, and thermal structure beneath and around active regions. Much progress is expected with data now provided by HMI's high spatial resolution observations and high duty cycle. There are two data processing pipelines (GONG and HMI) providing free access to the data and the results of the ring-diagram analysis. Here we will discuss the most recent results and improvements in the technique, as well as, the many challenges that still remain.

Rabello-Soares, M. C.

2013-12-01

111

DEFF Research Database (Denmark)

Safety-barrier diagrams and the related so-called 'bow-tie' diagrams have become popular methods in risk analysis. This paper describes the syntax and principles for constructing consistent and valid safety-barrier diagrams. The relation of safety-barrier diagrams to other methods such as fault trees and Bayesian networks is discussed. A simple method for quantification of safety-barrier diagrams is proposed. It is concluded that safety-barrier diagrams provide a useful framework for an electronic data structure that integrates information from risk analysis with operational safety management.

Duijm, Nijs Jan

2008-01-01

112

Multi-phase Flow Modeling applied to Metallurgical Processes

Digital Repository Infrastructure Vision for European Research (DRIVER)

Multiphase flow models have been improved significantly during the last two decades. Together with the development of more advanced numerical techniques and faster and cheaper computers we now see that computational fluid dynamics (CFD) becomes a powerful tool in predicting the performance of complex industrial processes. In particular the processes faced by the metallurgical industries may serve as examples of such complexity.

Johansen, Stein T.

2002-01-01

113

Information Flow Security in Tree-Manipulating Processes

Digital Repository Infrastructure Vision for European Research (DRIVER)

By enterprise workflows and web service technologies data is frequently represented in the form of XML documents. In the same time, these systems are highly security critical, because they may be in control of important processes of organizations, while communicating with external partners over the network. Therefore, this work describes three methods to verify information flow properties of processes manipulating tree-structured data.

Kova?cs, Ma?te? Amade?

2014-01-01

114

Self-Sustaining Nonlinear Dynamo Process in Keplerian Shear Flows

International Nuclear Information System (INIS)

A three-dimensional nonlinear dynamo process is identified in rotating plane Couette flow in the Keplerian regime. It is analogous to the hydrodynamic self-sustaining process in nonrotating shear flows and relies on the magnetorotational instability of a toroidal magnetic field. Steady nonlinear solutions are computed numerically for a wide range of magnetic Reynolds numbers but are restricted to low Reynolds numbers. This process may be important to explain the sustenance of coherent fields and turbulent motions in Keplerian accretion disks, where all its basic ingredients are present

2007-06-22

115

Energy Technology Data Exchange (ETDEWEB)

Optimality principles have been used for investigating physical processes in different areas. This work attempts to apply an optimal principle (that water flow resistance is minimized on global scale) to steady-state unsaturated flow processes. Based on the calculus of variations, we show that under optimal conditions, hydraulic conductivity for steady-state unsaturated flow is proportional to a power function of the magnitude of water flux. This relationship is consistent with an intuitive expectation that for an optimal water flow system, locations where relatively large water fluxes occur should correspond to relatively small resistance (or large conductance). Similar results were also obtained for hydraulic structures in river basins and tree leaves, as reported in other studies. Consistence of this theoretical result with observed fingering-flow behavior in unsaturated soils and an existing model is also demonstrated.

Liu, H. H.

2010-09-15

116

Two-Phase Flow Analyses During Throttling Processes

This study presents an experimental investigation of the throttling process of saturated fluorocarbon refrigerants (such as R116, R218, and R610) inside capillary tubes. For the detailed two-phase flow analyses, refrigerant R218 was selected. A divided capillary tube was prepared with a set of precise pressure and temperature sensors providing detailed information about the refrigerant flow behavior inside the tube. The metastable flow regions of the superheated liquid and of the two-phase vapor-liquid mixture were clearly detected. A correlation for the ‘underpressure’ of vaporization applicable for capillary flow of fluorocarbon refrigerants was determined. New experimental data were compared with a modified numerical model simulating all four capillary flow regions. A negative effect of non-condensing gases present within the cooling circuit on the overall capillary tube performance was experimentally noted.

Vacek, V.; Vinš, V.

2009-05-01

117

Constraints on rift thermal processes from heat flow and uplift

The implications of heat flow data available from five major Cenozoic continental rift systems for the processes of continental rifting are discussed, and simple thermal models of lithospheric thinning which predict uplift are used to further constrain the thermal processes in the lithosphere during rifting. Compilations of the heat flow data are summarized and the salient results of these compilations are briefly discussed. The uplift predictions of the slow and rapid thinning models, in which thinning is assumed to occur at a respectively slower and faster rate than heat can be conducted into the lithosphere, are presented. Comparison of uplift rates with model results indicates that the lithosphere is in a state between the two models. While uplift is predicted to continue after thinning has ceased due to thermal relaxation of the lithosphere, the rapid thinning model is always predicted to apply to surface heat flow, and an anomaly in this flow is not predicted to develop until after thinning has stopped.

Morgan, P.

1983-01-01

118

Numerical Modeling of Fluid Flow in the Tape Casting Process

Digital Repository Infrastructure Vision for European Research (DRIVER)

The flow behavior of the fluid in the tape casting process is analyzed. A simple geometry is assumed for running the numerical calculations in ANSYS Fluent and the main parameters are expressed in non-dimensional form. The effect of different values for substrate velocity and pressure force on the flow pattern as well as resultant tape thickness is evaluated. The analysis deals with the case of parallel blades and focuses on the ratio between the present hydrostatic pressure and the magnitude...

Jabbari, Masoud; Hattel, Jesper Henri

2011-01-01

119

OF.CPP: Consistent Packet Processing for OpenFlow

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper demonstrates a new class of bugs that is likely to occur in enterprise OpenFlow deployments. In particular, step-by-step, reactive establishment of paths can cause network-wide inconsistencies or performance- and space-related inefficiencies. The cause for this behavior is inconsistent packet processing: as the packets travel through the network they do not encounter consistent state at the OpenFlow controller. To mitigate this problem, we propose to use transactional semantics at ...

2013-01-01

120

Rotating Thermal Flows in Natural and Industrial Processes

Rotating Thermal Flows in Natural and Industrial Processes provides the reader with a systematic description of the different types of thermal convection and flow instabilities in rotating systems, as present in materials, crystal growth, thermal engineering, meteorology, oceanography, geophysics and astrophysics. It expressly shows how the isomorphism between small and large scale phenomena becomes beneficial to the definition and ensuing development of an integrated comprehensive framework. This allows the reader to understand and assimilate the underlying, quintessential mechanisms w

Lappa, Marcello

2012-01-01

121

On-line sample processing methods in flow analysis

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this chapter, the state of the art of flow injection and related approaches thereof for automation and miniaturization of sample processing regardless of the aggregate state of the sample medium is overviewed. The potential of the various generation of flow injection for implementation of in-line dilution, derivatization, separation and preconcentration methods encompassing solid reactors, solvent extraction, sorbent extraction, precipitation/coprecipitation, hydride/vapor generation and d...

Miro?, Manuel; Hansen, Elo Harald

2007-01-01

122

POST-PROCESSING TECHNIQUES SUITABILITY FOR MESOLEVEL FREE BOUNDARY FLOWS

Digital Repository Infrastructure Vision for European Research (DRIVER)

Reliable flow simulation software is inevitable to determine an optimal injection strategy in Liquid Composite Molding processes. Several methodologies can be implemented into standard software in order to reduce CPU time. Post-processing techniques might be one of them. Post-processing a finite element solution is a well-known procedure, which consists in a recalculation of the originally obtained quantities such that the rate of convergence increases without the need for expe...

Dimitrovova?, Zuzana

2010-01-01

123

Subsea flow assurance and process monitoring via gamma radiation

International Nuclear Information System (INIS)

Condition monitoring and process control with the use of gamma radiation is considered to be the most reliable detection principle for a wide range of applications throughout the oil and gas industries, from measuring mechanical integrity to dynamic process fluid monitoring. The growing numbers of advanced subsea processing projects and pipeline flow assurance studies currently adds an increasing number of subsea applications to the radiation measurement reference list (author) (ml)

2007-01-01

124

Modeling a novel glass immobilization waste treatment process using flow

Energy Technology Data Exchange (ETDEWEB)

One option for control and disposal of surplus fissile materials is the Glass Material Oxidation and Dissolution System (GMODS), a process developed at ORNL for directly converting Pu-bearing material into a durable high-quality glass waste form. This paper presents a preliminary assessment of the GMODS process flowsheet using FLOW, a chemical process simulator. The simulation showed that the glass chemistry postulated ion the models has acceptable levels of risks.

Ferrada, J.J.; Nehls, J.W. Jr.; Welch, T.D.; Giardina, J.L.

1996-01-25

125

This exercise should be used after you think students know what AFM diagrams are and how they work. This is sort of a quiz - to see if they can properly interpret the diagrams. There is no point moving on to real projects that involve AFM diagrams if the students don't understand the basics.

Perkins, Dexter

126

Digital Repository Infrastructure Vision for European Research (DRIVER)

Although the field of entrepreneurship abounds in studies attempting to explain the creation of new ventures from an array of theoretical perspectives, the answer to the critical question regarding "how" the process unfolds over time remains unsolved. The main goal of this paper is to demonstrate the importance of integrating an engineering point of view with the new business creation process in order to find the answer. This study will dig deeper into the issue by proposing the use of SADT (...

Hernandez Rico, Tatiana; Dubois, Patrice; Le Coq, Marc

2011-01-01

127

Selected topics on the nonrelativistic diagram technique

International Nuclear Information System (INIS)

The construction of the diagrams describing various processes in the four-particle systems is considered. It is shown that these diagrams, in particular the diagrams corresponding to the simple mechanisms often used in nuclear and atomic reaction theory, are readily obtained from the Faddeev-Yakubovsky equations. The covariant four-dimensional formalism of nonrelativistic Feynman graphs and its connection to the three-dimensional graph technique are briefly discussed

1983-01-01

128

Blood flow determination using recursive processing: a digital radiographic method.

Temporal filtration of fluoroscopic video sequences is being used as an alternative to pulsed digital subtraction angiography. Using the same image processing architecture and a slight modification in processing logic a parametric image can be synthesized from such a temporally filtered image sequence in virtual real time, i.e., an image sequence that spans T seconds takes exactly T seconds to process. Off-line computer processing is not required. Initial phantom studies imply that the time to maximum opacification (tmax) can be used to determine absolute and relative blood flow with a high confidence level (r greater than .989). Phantom and animal examples are presented. PMID:6351164

Kruger, R A; Bateman, W; Liu, P Y; Nelson, J A

1983-10-01

129

Blood flow determination using recursive processing: a digital radiographic method

International Nuclear Information System (INIS)

Temporal filtration of fluoroscopic video sequences is being used as an alternative to pulsed digital subtraction angiography. Using the same image processing architecture and a slight modification in processing logic a parametric image can be synthesized from such a temporally filtered image sequence in virtual real time, i.e., an image sequence that spans T seconds takes exactly T seconds to process. Off-line computer processing is not required. Initial phantom studies imply that the time to maximum opacification (t/sub max/) can be used to determine absolute and relative blood flow with a high confidence level (r > .989). Phantom and animal examples are presented

1983-01-01

130

Purex co-processing of spent LWR fuels: flow sheet

International Nuclear Information System (INIS)

Purex co-processing of spent LWR fuel is investigated. In purex co-processing, uranium and plutonium in spent fuel are processed and recovered together as a single stream, while in standard purex reprocessing uranium and plutonium are obtained as separate streams. A two-step (co-decontamination and co-stripping) flow sheet for purex co-processing is devised; concentrations, recoveries and decontamination factors are calculated; and methods to co-convert uranium-plutonium nitrate to mixed oxide are reviewed. A closed nuclear fuel cycle in which at no point uranium and plutonium are separated from each other is reached

2005-01-01

131

We use boundary layer analysis for an open system consisting of two parallel totally asymmetric simple exclusion processes with Langmuir kinetics under a biased lane-changing rule. The two kinds of phase transitions—bulk transitions and surface transitions—have been examined. The dynamics of shock and their dependence on the system parameters have been investigated. We find a reduction in the number of steady-state phases with increase in lane-changing rate.

Gupta, Arvind Kumar; Dhiman, Isha

2014-02-01

132

Analysis of Nike distribution facility's outbound process flow

Digital Repository Infrastructure Vision for European Research (DRIVER)

A simulation study was conducted to run different scenarios on the outbound process flow affected by the Soccer World Cup 2010 event. Along with Excel spreadsheets this simulation proved to be vital in the decision making of the build up for the World Cup.

Wagenaar, Werner

2009-01-01

133

Coaching, lean processes and the concept of flow

DEFF Research Database (Denmark)

The chapter takes us inside Nordea Bank to look at how coaching was used to support their leadership development as they underwent a major change effort implementation. Drawing on the literature on Lean processes, flow and coaching, itÂ demonstrates some of the challenges and opportunities of working with coaching in a systematic way acrossÂ broader initiatives in organizations.

Skytte GÃ¸rtz, Kim Erik

2008-01-01

134

Features, Events, and Processes in UZ Flow and Transport

International Nuclear Information System (INIS)

Unsaturated zone (UZ) flow and radionuclide transport is a component of the natural barriers that affects potential repository performance. The total system performance assessment (TSPA) model, and underlying process models, of this natural barrier component capture some, but not all, of the associated features, events, and processes (FEPs) as identified in the FEPs Database (Freeze, et al. 2001 [154365]). This analysis and model report (AMR) discusses all FEPs identified as associated with UZ flow and radionuclide transport. The purpose of this analysis is to give a comprehensive summary of all UZ flow and radionuclide transport FEPs and their treatment in, or exclusion from, TSPA models. The scope of this analysis is to provide a summary of the FEPs associated with the UZ flow and radionuclide transport and to provide a reference roadmap to other documentation where detailed discussions of these FEPs, treated explicitly in TSPA models, are offered. Other FEPs may be screened out from treatment in TSPA by direct regulatory exclusion or through arguments concerning low probability and/or low consequence of the FEPs on potential repository performance. Arguments for exclusion of FEPs are presented in this analysis. Exclusion of specific FEPs from the UZ flow and transport models does not necessarily imply that the FEP is excluded from the TSPA. Similarly, in the treatment of included FEPs, only the way in which the FEPs are included in the UZ flow and transport models is discussed in this document. This report has been prepared in accordance with the technical work plan for the unsaturated zone subproduct element (CRWMS MandO 2000 [153447]). The purpose of this report is to document that all FEPs are either included in UZ flow and transport models for TSPA, or can be excluded from UZ flow and transport models for TSPA on the basis of low probability or low consequence. Arguments for exclusion are presented in this analysis. Exclusion of specific FEPs from UZ flow and transport models does not necessarily imply that the FEP is excluded from the TSPA. Similarly, in the treatment of included FEPs, only the way in which FEPs are included in UZ flow and transport models is discussed in this document

2001-01-01

135

Engineered Barrier System Degradation, Flow, and Transport Process Model Report

International Nuclear Information System (INIS)

Performance of a potential Yucca Mountain high-level radioactive waste repository depends on both the natural barrier system (NBS) and the engineered barrier system (EBS) and on their interactions. Although the waste packages are generally considered as components of the EBS, the EBS as defined in the Engineered Barrier System Degradation, Flow, and Transport Process Model Report (PMR), herein referred to as the EBS PMR, includes all engineered components outside the waste packages. Waste packages and waste-form performance is described and modeled in other PMRs. Performance of the drip shield as a means of diverting water is included here, both as-built and following degradation because of various processes. The specific mechanisms and rates of drip shield failure from corrosion and seismic activity are described and modeled in the WP PMR. To evaluate the postclosure performance of a potential repository at Yucca Mountain, a total system performance assessment (TSPA) will be conducted. A set of nine PMRs, of which this document is one, is being developed to summarize the technical basis for each of the process models supporting the TSPA model. These reports cover the following areas: Integrated Site Model; Unsaturated Zone Flow and Transport; Near Field Environment; Engineered Barrier System Degradation, Flow, and Transport; Waste Package Degradation; Waste Form Degradation; Saturated Zone Flow and Transport; Biosphere; and Disruptive Events

2000-01-01

136

Efficient Inference on Generalized Fault Diagrams

Digital Repository Infrastructure Vision for European Research (DRIVER)

The generalized fault diagram, a data structure for failure analysis based on the influence diagram, is defined. Unlike the fault tree, this structure allows for dependence among the basic events and replicated logical elements. A heuristic procedure is developed for efficient processing of these structures.

Shachter, Ross D.; Bertrand, Leonard

2013-01-01

137

Irreversible transfer processes of thermoelectric generators

We discuss a novel tool based on heat flow diagrams for analyzing irreversible processes associated with thermoelectric devices and discuss some ambiguous descriptions and errors in related investigations. We consider thermoelectric generators as a paradigm of a heat engine cycle and determine the heat flow distribution by treating the one-dimensional heat transfer differential equation. Representative heat flow diagrams are used to study the influence of internal and external irreversible processes of heat conduction and Joule heat generation.

Chen, Min; Rosendahl, Lasse; Bach, Inger; Condra, Thomas; Pedersen, John

2007-09-01

138

Digital Repository Infrastructure Vision for European Research (DRIVER)

The Voronoi diagram of a finite set of objects is a fundamental geometric structure that subdivides the embedding space into regions, each region consisting of the points that are closer to a given object than to the others. We may define various variants of Voronoi diagrams depending on the class of objects, the distance function and the embedding space. In this paper, we investigate a framework for defining and building Voronoi diagrams for a broad class of distance functions called Bregman...

Boissonnat, Jean-daniel; Nielsen, Frank; Nock, Richard

2010-01-01

139

Flow processes in the meshed fissure rock model

Energy Technology Data Exchange (ETDEWEB)

Assuming an idealized, schematic form of fissure systems and based on the known laws of fissure flow, the influence of fissure distribution and fissure aperture size on the flow processes in rock has been studied. Based on the assumed parameters of fissures, 40 cases with different fissure geometry have been solved. The computer programme has been developed from an existent programme for meshed pipe networks. By means of some selected examples the most essential results are presented as patterns of potential and flow distribution. The comprehensive interpretation of the model results permits conclusions to be drawn for practical application in groundwater hydrology. The results obtained are of importance, for example in evaluating the effects to be expected as a result of groundwater drawdown in the construction of deep rock excavations or of drawdown due to wells. Conclusions regarding the migration of contaminants and localization of contamination sources may also be drawn.

Schwille, F.; Ubell, K.

1982-12-01

140

Flow processes in the meshed fissure rock model

International Nuclear Information System (INIS)

Assuming an idealized, schematic form of fissure systems and based on the known laws of fissure flow, the influence of fissure distribution and fissure aperture size on the flow processes in rock has been studied. Based on the assumed parameters of fissures, 40 cases with different fissure geometry have been solved. The computer programme has been developed from an existent programme for meshed pipe networks. By means of some selected examples the most essential results are presented as patterns of potential and flow distribution. The comprehensive interpretation of the model results permits conclusions to be drawn for practical application in groundwater hydrology. The results obtained are of importance, for example in evaluating the effects to be expected as a result of groundwater drawdown in the construction of deep rock excavations or of drawdown due to wells. Conclusions regarding the migration of contaminants and localization of contamination sources may also be drawn. (orig.)

1982-12-01

141

Multilevel flow modelling of process plant for diagnosis and control

International Nuclear Information System (INIS)

The paper describes the multilevel flow modelling methodology which can be used to construct functional models of energy and material processing systems. The models describe mass and energy flow topology on different levels of abstraction and represent the hierarchical functional structure of complex systems. A model of a nuclear power plant (PWR) is presented in the paper for illustration. Due to the consistency of the method, multilevel flow models provide specifications of plant goals and functions and may be used as a basis for design of computer-based support systems for the plant operator. Plant control requirements can be derived from the models and due to independence of the actual controller implementation the method may be used as basic for design of control strategies and for the allocation of control tasks to the computer and the plant operator. (author)

1982-09-02

142

Semantics of UML 2.0 Activity Diagram for Business Modeling by Means of Virtual Machine

The paper proposes a more formalized definition of UML 2.0 Activity Diagram semantics. A subset of activity diagram constructs relevant for business process modeling is considered. The semantics definition is based on the original token flow methodology, but a more constructive approach is used. The Activity Diagram Virtual machine is defined by means of a metamodel, with operations defined by a mix of pseudocode and OCL pre- and postconditions. A formal procedure is described which builds the virtual machine for any activity diagram. The relatively complicated original token movement rules in control nodes and edges are combined into paths from an action to action. A new approach is the use of different (push and pull) engines, which move tokens along the paths. Pull engines are used for paths containing join nodes, where the movement of several tokens must be coordinated. The proposed virtual machine approach makes the activity semantics definition more transparent where the token movement can be easily tra...

Vitolins, V; Vitolins, Valdis; Kalnins, Audris

2005-01-01

143

In this activity, students practice placing big and small shapes into Venn diagrams depending on the rules of the diagram. Students can either specify these rules or have the applet assign the rules so they can try to figure them out by placing shapes in the diagram. This activity allows students to explore Venn diagrams and the terms associated with set theory. This activity includes supplemental materials, including background information about the topics covered, a description of how to use the application, and exploration questions for use with the java applet.

2010-01-01

144

Recharge and flow processes in a till aquitard

DEFF Research Database (Denmark)

Eastern Denmark is primarily covered by clay till. The transformation of the excess rainfall into laterally diverted groundwater flow, drain flow, stream flow, and recharge to the underlying aquifer is governed by complicatedinterrelated processes. Distributed hydrological models provide a framework for assessing the individual flow components and forestablishing the overall water balance. Traditionally such models are calibrated against measurements of stream flow, head in the aquiferand perhaps drainage flow. The head in the near surface clay till deposits have generally not been measured and therefore not consideredin the calibration procedure.In a 16 km2 rural catchment, 15 shallow wells were installed in the upstream end for continuous measurements of the fluctuations in hydraulic head. In addition data were obtained from two wells penetrating to the deeper artesian aquifer, one located near the shallow wells and one in the valley adjacent to the stream. Precipitation and stream flow gauging along with potential evaporation estimates from a nearby weather station provide the basic data for the overall water balance assessment. The geological composition was determined from geoelectrical surveys along three transects, supported by geophysical logs in deepwells, lowflow records at the outlet of the catchment and three tributaries, and soil maps. Slug tests were carried to obtain data forhydraulic conductivity.The time series of hydraulic head depth in the shallow wells were analyzed using linear transfer noise functions on driving input timeseries and kriging techniques in order to identify correlation structures in time and space among the wells.The distributed and physically based hydrological model code MIKE SHE was applied to the catchment. The model considers one-dimensional flow in the unsaturated zone and three-dimensional below. Drainage flow isempirically modelled as a linear reservoir using a time constant related to drain pipe capacity, spacing and soil hydraulic conductivity.Key parameters are calibrated against records of precipitation, potential evaporation and stream flow. Simulation based on historicalrecords prior to the installation of subsurface drainage in 1/3 of the catchment was carried out in order to investigate the impact ofdrainage on streamflow and access the use of the linear reservoir assumption. Subsequently, data from the shallow wells wereconsidered in order to analyse the value of such data in the calibration procedure and particularly in estimating the areal variation inrecharge.

SchrÃ¸der, Thomas Morville; HÃ¸gh Jensen, Karsten

1999-01-01

145

Validation of traffic flow models on processed GPS data

Digital Repository Infrastructure Vision for European Research (DRIVER)

Macroscopic traffic flow models allow describing the spatio-temporal evolution of traffic density. Their sound mathematical structure consisting of partial differential equations of hyperbolic type and the related efficient numerical schemes enable fast computations to monitor traffic evolution. The aim of the internship was to validate these models against processed data provided by the industrial partners Autoroutes Trafic and VINCI Autoroutes. Targeted applications included congestion dete...

Cabassi, Alessandra; Goatin, Paola

2013-01-01

146

The process flow and structure of an integrated stroke strategy

Digital Repository Infrastructure Vision for European Research (DRIVER)

Introduction: In the Canadian province of Alberta access and quality of stroke care were suboptimal, especially in remote areas. The government introduced the Alberta Provincial Stroke Strategy (APSS) in 2005, an integrated strategy to improve access to stroke care, quality and efficiency which utilizes telehealth. Research question: What is the process flow and the structure of the care pathways of the APSS?Methodology: Information for this article was obtained using documentation, archival ...

Bussel, Emma F.; Jeerakathil, Thomas; Schrijvers, A. J. P.

2013-01-01

147

Production process flow optimization at Euro-Plastifoam (Pty) Ltd

Digital Repository Infrastructure Vision for European Research (DRIVER)

Various methods, tools and techniques will be applied in order to improve, and ultimately optimize, the production process flow at Euro-Plastifoam. Work measurement will be performed, followed by value stream analysis as well as the application of problem identification methods. This again, will be followed by layout analysis and improvement. Other proposed solutions include the introduction of a Kanban system, 5S House keeping and Single Minute Exchange of Dies (SMED).

Zietsman, Ignatius

2011-01-01

148

Monte Carlo simulation is used to explore the effects of the Eley-Rideal (ER) process on the phase diagram of the Langmuir Hinshelwood (LH) type monomer dimer (CO O2) catalytic reaction on the surface and subsurface of a body-centred cubic structure, which extends to only two layers in the z-direction. The dimer (O2) is adsorbed in such a way that it takes one surface site whereas the second site is from the subsurface. For this mechanism, an interesting situation develops. The production rate of CO2 is found to be consistent with experiment. The qualitative trend of the surface oxygen coverage is not consistent with the experimental situation in one model while it is found to be consistent with that in another model, i.e. the coverage of surface oxygen decreases slowly with increase of concentration of CO (yCO). Moreover, the production of CO2 can be predicted in the form of a mathematical relation.

Qaisrani, A. U.; Khalid, M.; Musa Kaleem, Baloch

2004-09-01

149

Characterization of Mixing Process in a Microchannel Flow

The use of micro scale fluid devices in biological sample preparation and delivery has received increasing attention in recent years. These devices are usually operated at very low Reynolds numbers due to their small sizes and the use of turbulence for effective mixing is not feasible. A preliminary study of using a pulsed source-sink system to enhance mixing in a microchannel flow is undertaken. We are interested in studying possible generation of chaotic advection for mixing enhancement. The channel (200 by 500 microns) is fabricated using DeepRIE and anodic glass bonding processes. The flow rate is controlled by a motorized syringe pump system with the channel Reynolds number varying between 1 to 1,000. Two fluid streams, independently controlled by a split valve, merge at the inlet to form the main channel flow. The interface of the two streams is made visible by staining one stream with fluorescent dye. The mixing process is then visualized by an epi-fluorescent microscope system. Finally, a micro-PIV system is used to study quantitatively the mixing process.

Lee, Y.-K.; Shih, C.; Ho, C.-M.

1999-11-01

150

Coronary artery disease continues to be the leading cause of death for adults in the United States. Magnetic resonance imaging (MR) has the potential to dramatically impact the diagnosis of heart disease by noninvasively providing a wide range of anatomic and physiologic information. Previous research has shown that coronary flow, one component of a complete examination, can be accurately measured in the left anterior descending artery in vivo. The current work validates MR flow measurements in canine circumflex arteries using transit time ultrasound as a standard. The circumflex artery experiences greater in-plane motion and is a more stringent test for flow measurement accuracy. This work also compares two methods of processing MR velocity data, phase difference and complex difference techniques, and examines the sources of error present in the animal validation model. Phase difference processing with a 30% magnitude threshold best matched the mean ultrasound flow values (30% PD = 1.04 x US + 1.49, r = 0.94), but it was very sensitive to vessel boundary identification. The complex difference process was less sensitive to vessel boundary identification and correlated well with the transit time ultrasound despite systematic underestimations. The reasons for the discrepancies are shown to stem from a number of possible sources including variability of the ultrasound standard, low signal-to-noise ratios in the MR images, sensitivity of the MR technique to vessel boundary identification, and motion artifacts in the images. PMID:9797147

Wedding, K L; Grist, T M; Folts, J D; Maalej, N; Vigen, K K; Peters, D C; Osman, H; Mistretta, C A

1998-11-01

151

Hydrothermal Processing of Macroalgal Feedstocks in Continuous-Flow Reactors

Energy Technology Data Exchange (ETDEWEB)

Wet macroalgal slurries can be converted into a biocrude by hydrothermal liquefaction (HTL). High levels of carbon conversion to gravity-separable oil product were accomplished at relatively low temperature (350 ?C) in a pressurized (sub-critical liquid water) environment (20 MPa). As opposed to earlier work in batch reactors reported by others, direct oil recovery was achieved without the use of a solvent and biomass trace mineral components were removed by processing steps so that they did not cause processing difficulties. In addition, catalytic hydrothermal gasification was effectively applied for HTL byproduct water cleanup and fuel gas production from water soluble organics. As a result, high conversion of macroalgae to liquid and gas fuel products was found with low levels of organic contamination in byproduct water. Both process steps were accomplished in continuous-flow reactor systems such that design data for process scale-up was generated.

Elliott, Douglas C.; Hart, Todd R.; Neuenschwander, Gary G.; Rotness, Leslie J.; Roesijadi, Guritno; Zacher, Alan H.; Magnuson, Jon K.

2014-02-18

152

RANS-based simulation of turbulent wave boundary layer and sheet-flow sediment transport processes

DEFF Research Database (Denmark)

A numerical model coupling the horizontal component of the incompressible Reynolds-averaged Navierâ??Stokes (RANS) equationswith two-equation kâ??Ï? turbulence closure is presented and used to simulate a variety of turbulent wave boundary layer processes. The hydrodynamic model is additionally coupled with bed and suspended load descriptions, the latter based on an unsteady turbulent-diffusion equation, for simulation of sheet-flow sediment transport processes. In addition to standard features common within such RANS-based approaches, the present model includes: (1) hindered settling velocities at high suspended sediment concentrations, (2) turbulence suppression due to density gradients in the waterâ??sand mixture, (3) boundary layer streaming due to convective terms, and (4) convergingâ??diverging effects due to a sloping bed. The present model therefore provides a framework for simultaneous inclusion of a number of local factors important within cross-shore wave boundary layer and sediment transport dynamics. The hydrodynamic model is validated for both hydraulically smooth and rough conditions, based on wave friction factor diagrams and boundary layer streaming profiles, with the results in excellent agreement with experimental and/or previous numerical work. The sediment transport model is likewise validated against oscillatory tunnel experiments involving both velocity-skewed and acceleration-skewed flows, as well as against measurements beneath real progressive waves.Model capabilities are exploited to investigate the importance of boundary layer streaming effects on sediment transport in selected velocity-skewed conditions. For the medium sand grain conditions considered, the model results suggest that streaming effects can enhance onshore sediment transport rates by asmuch as a factor of two.Moreover, for fine sand conditions streaming (and related convective) effects are demonstrated to potentially reverse the direction of net transport (i.e. from offshore to onshore) relative that predicted in oscillatory tunnel conditions. The developed model is implemented within the popular Matlab environment, and hence may be attractive for both research and educational purposes.

Fuhrman, David R.; SchlÃ¸er, Signe

2013-01-01

153

Hopf algebra approach to Feynman diagram calculations

The Hopf algebra structure underlying Feynman diagrams which governs the process of renormalization in perturbative quantum field theory is reviewed. Recent progress is briefly summarized with an emphasis on further directions of research.

Ebrahimi-Fard, K; Ebrahimi-Fard, Kurusch; Kreimer, Dirk

2005-01-01

154

Numerical Modeling of Fluid Flow in the Tape Casting Process

The flow behavior of the fluid in the tape casting process is analyzed. A simple geometry is assumed for running the numerical calculations in ANSYS Fluent and the main parameters are expressed in non-dimensional form. The effect of different values for substrate velocity and pressure force on the flow pattern as well as resultant tape thickness is evaluated. The analysis deals with the case of parallel blades and focuses on the ratio between the present hydrostatic pressure and the magnitude of the viscous force. A new non-dimensional height for the tape thickness is proposed and the effect of the substrate velocity is evaluated. The results of the modeling show that a relatively uniform tape thickness can be achieved. Moreover, the results are compared with selected experimental and analytical data from literature and good agreement is found.

Jabbari, Masoud; Hattel, Jesper

2011-09-01

155

Numerical Modeling of Fluid Flow in the Tape Casting Process

DEFF Research Database (Denmark)

The flow behavior of the fluid in the tape casting process is analyzed. A simple geometry is assumed for running the numerical calculations in ANSYS Fluent and the main parameters are expressed in non-dimensional form. The effect of different values for substrate velocity and pressure force on the flow pattern as well as resultant tape thickness is evaluated. The analysis deals with the case of parallel blades and focuses on the ratio between the present hydrostatic pressure and the magnitude of the viscous force. A new non-dimensional height for the tape thickness is proposed and the effect of the substrate velocity is evaluated. The results of the modeling show that a relatively uniform tape thickness can be achieved. Moreover, the results are compared with selected experimental and analytical data from literature and good agreement is found.

Jabbari, Masoud; Hattel, Jesper Henri

2011-01-01

156

Flow processes at low temperatures in ultrafine-grained aluminum

International Nuclear Information System (INIS)

Experiments were conducted to evaluate the flow behavior of pure aluminum at low temperatures. Samples were processed by equal-channel angular pressing (ECAP) to give a grain size of ?1.2 ?m and compression samples were cut from the as-pressed billets and tested over a range of strain rates at temperatures up to 473 K. The results show the occurrence of steady-state flow in these highly deformed samples and a detailed analysis gives a low strain rate sensitivity and an activation energy similar to the value for grain boundary diffusion. By using depth-sensing indentation testing and atomic force microscopy, it is shown that grain boundary sliding occurs in this material at low temperatures. This result is attributed to the presence of high-energy non-equilibrium boundaries in the severely deformed samples

2006-10-25

157

Flow processes at low temperatures in ultrafine-grained aluminum

Energy Technology Data Exchange (ETDEWEB)

Experiments were conducted to evaluate the flow behavior of pure aluminum at low temperatures. Samples were processed by equal-channel angular pressing (ECAP) to give a grain size of {approx}1.2 {mu}m and compression samples were cut from the as-pressed billets and tested over a range of strain rates at temperatures up to 473 K. The results show the occurrence of steady-state flow in these highly deformed samples and a detailed analysis gives a low strain rate sensitivity and an activation energy similar to the value for grain boundary diffusion. By using depth-sensing indentation testing and atomic force microscopy, it is shown that grain boundary sliding occurs in this material at low temperatures. This result is attributed to the presence of high-energy non-equilibrium boundaries in the severely deformed samples.

Chinh, Nguyen Q. [Department of General Physics, Eoetvoes University of Budapest, 1117 Budapest, Pazmany P. setany 1/A. (Hungary)]. E-mail: chinh@metal.elte.hu; Szommer, Peter [Department of General Physics, Eoetvoes University of Budapest, 1117 Budapest, Pazmany P. setany 1/A. (Hungary); Csanadi, Tamas [Department of General Physics, Eoetvoes University of Budapest, 1117 Budapest, Pazmany P. setany 1/A. (Hungary); Langdon, Terence G. [Departments of Aerospace and Mechanical Engineering and Materials Science, University of Southern California, Los Angeles, CA 90089-1453 (United States); Materials Research Group, School of Engineering Sciences, University of Southampton, Southampton SO17 1BJ (United Kingdom)

2006-10-25

158

Post-processing methods of PIV instantaneous flow fields for unsteady flows in turbomachines

Digital Repository Infrastructure Vision for European Research (DRIVER)

The Particle Image Velocimetry is undoubtedly one of the most important technique in Fluid-dynamics since it allows to obtain a direct and instantaneous visualization of the flow field in a non-intrusive way. This innovative technique spreads in a wide number of research fields, from aerodynamics to medicine, from biology to turbulence researches, from aerodynamics to combustion processes. The book is aimed at presenting the PIV technique and its wide range of possible applications so as to p...

Cavazzini, Giovanna; Dazin, Antoine; Pavesi, Giorgio; Dupont, Patrick; Bois, Ge?rard

2012-01-01

159

Characterizing Communication Channel Deadlocks in Sequence Diagrams

Digital Repository Infrastructure Vision for European Research (DRIVER)

UML sequence diagrams (SDs) are a mainstay of requirements specifications for communication protocols. Mauw and Reniers' algebraic (MRA) semantics formally specifies a behaviour for these SDs that guarantees deadlock free processes. Practitioners commonly use communication semantics that differ from MRA, which may result in deadlocks. For example FIFO, token ring, etc. We define a process algebra that is an extension of the MRA semantics for regular sequence diagrams. Our algebra can descr...

Mitchell, Bill

2008-01-01

160

The Classroom as Rhizome: New Strategies for Diagramming Knotted Interactions

This article calls attention to the unexamined role of diagrams in educational research and offers examples of alternative diagramming practices or tools that shed light on classroom interaction as a rhizomatic process. Drawing extensively on the work of Latour, Deleuze and Guattari, and Chatelet, this article explores the power of diagramming as…

de Freitas, Elizabeth

2012-01-01

161

ROLE OF UML SEQUENCE DIAGRAM CONSTRUCTS IN OBJECT LIFECYCLE CONCEPT

Directory of Open Access Journals (Sweden)

Full Text Available When modeling systems and using UML concepts, a real system can be viewed in several ways. The RUP (Rational Unified Process defines the "4 + 1 view": 1. Logical view (class diagram (CD, object diagram (OD, sequence diagram (SD, collaboration diagram (COD, state chart diagram (SCD, activity diagram (AD, 2.Process view (use case diagram, CD, OD, SD, COD, SCD, AD, 3. Development view (package diagram, component diagram, 4. Physical view (deployment diagram, and 5. Use case view (use case diagram, OD, SD, COD, SCD, AD which combines the four mentioned above. With sequence diagram constructs we are describing object behavior in scope of one use case and their interaction. Each object in system goes through a so called lifecycle (create, supplement object with data, use object, decommission object. The concept of the object lifecycle is used to understand and formalize the behavior of objects from creation to deletion. With help of sequence diagram concepts our paper will describe the way of interaction modeling between objects through lifeline of each of them, and their importance in software development.

Robert Mužar

2007-06-01

162

Bibliographic Notes on Voronoi Diagrams.

The paper presents a comprehensive annotated bibliography on various theoretical and algorithmic aspects of Voronoi diagrams and related diagrams. Bibliographic notes on the relationship between Voronoi diagrams and solutions to the Euclidean traveling sa...

J. Bernal

1993-01-01

163

A traffic flow model for bio-polymerization processes.

Bio-polymerization processes like transcription and translation are central to proper function of a cell. The speed at which the bio-polymer grows is affected both by the number of pauses of elongation machinery, as well the number of bio-polymers due to crowding effects. In order to quantify these effects in fast transcribing ribosome genes, we rigorously show that a classical traffic flow model is the limit of a mean occupancy ODE model. We compare the simulation of this model to a stochastic model and evaluate the combined effect of the polymerase density and the existence of pauses on the instantaneous transcription rate of ribosomal genes. PMID:23404039

Davis, Lisa; Gedeon, Tomáš; Gedeon, Jakub; Thorenson, Jennifer

2014-02-01

164

Procedure level data flow processing on dynamic structure multimicroprocessors

Energy Technology Data Exchange (ETDEWEB)

Topstar, a highly parallel multi-microprocessor system is designed and constructed. It executes procedure level data flow processing (one data flow node is one procedure). Topstar is composed of two kinds of modules (CMS and PMS). Each module is a conventional micro computer system. The connective structure of Topstar is a locally connected bipartite graph. The control right belongs to each CM (which keeps unenabled data), and distributed control mechanism is attained. The load balancing problem is solved by the free competition rule. Five kinds of basic nodes are prepared for programming in the data flow graph language. Most Petri nets, involved in the free-choice Petri net subclass, can be realized by using these basic nodes. System software is implemented. The overflow in data buffers is avoided by introducing inhibitors (of the Petri net). Plural data buffers are attached to each node, and tokens can get ahead of others to provide more pipeline parallelism. Several program structures (such as conditional branch, loop and recursion) are available. Topstar-II consisting of 24 microprocessors is constructed and working with some applications. They are parallel mergesort, simulation of logical circuits, some arithmetic calculation, etc. Actually measured results in the case of parallel merge-sort are also reported. 9 references.

Suzuki, T.; Kurihara, K.; Tanaka, H.; Moto-oka, T.

1982-01-01

165

This is a line drawing of a Windows PC keyboard complete with labels for each key. This diagram is used on tests where students are asked to circle the keys that would be used to perform various functions.

Ward, Charles

2011-01-21

166

Groundwater flow and sorption processes in fractured rocks (I)

Energy Technology Data Exchange (ETDEWEB)

This study is objected to characterize groundwater flow and sorption processes of the contaminants (ground-water solutes) along the fractured crystalline rocks in Korea. Considering that crystalline rock mass is an essential condition for using underground space cannot be overemphasized the significance of the characterizing fractured crystalline rocks. the behavior of the groundwater contaminants is studied in related to the subsurface structure, and eventually a quantitative technique will be developed to evaluate the impacts of the contaminants on the subsurface environments. The study has been carried at the Samkwang mine area in the Chung-Nam Province. The site has Pre-Cambrian crystalline gneiss as a bedrock and the groundwater flow system through the bedrock fractures seemed to be understandable with the study on the subsurface geologic structure through the mining tunnels. Borehole tests included core logging, televiewer logging, constant pressure fixed interval length tests and tracer tests. The results is summarized as follows; 1) To determine the hydraulic parameters of the fractured rock, the transient flow analysis produce better results than the steady - state flow analysis. 2) Based on the relationship between fracture distribution and transmissivities measured, the shallow part of the system could be considered as a porous and continuous medium due to the well developed fractures and weathering. However, the deeper part shows flow characteristics of the fracture dominant system, satisfying the assumptions of the Cubic law. 3) Transmissivities from the FIL test were averaged to be 6.12 x 10{sup -7}{sub m}{sup 2}{sub /s}. 4) Tracer tests result indicates groundwater flow in the study area is controlled by the connection, extension and geometry of fractures in the bedrock. 5) Hydraulic conductivity of the tracer-test interval was in maximum of 7.2 x 10{sup -6}{sub m/sec}, and the effective porosity of 1.8 %. 6) Composition of the groundwater varies with that of contacting geomedia and the significant change occurs in K and Fe. 7) Metal ions in groundwater were found to be sorbed onto groundwater particulates. (author). 128 refs., 39 tabs., 49 figs.

Kim, Won Young; Woo, Nam Chul; Yum, Byoung Woo; Choi, Young Sub; Chae, Byoung Kon; Kim, Jung Yul; Kim, Yoo Sung; Hyun, Hye Ja; Lee, Kil Yong; Lee, Seung Gu; Youn, Youn Yul; Choon, Sang Ki [Korea Institute of Geology Mining and Materials, Taejon (Korea, Republic of)

1996-12-01

167

Coded Ultrasound for Blood Flow Estimation Using Subband Processing

DEFF Research Database (Denmark)

This paper investigates the use of coded excitation for blood flow estimation in medical ultrasound. Traditional autocorrelation estimators use narrow-band excitation signals to provide sufficient signal-to-noise-ratio (SNR) and velocity estimation performance. In this paper, broadband coded signals are used to increase SNR, followed by subband processing. The received broadband signal is filtered using a set of narrow-band filters. Estimating the velocity in each of the bands and averaging the results yields better performance compared with what would be possible when transmitting a narrow-band pulse directly. Also, the spatial resolution of the narrow-band pulse would be too poor for brightness-mode (B-mode) imaging, and additional transmissions would be required to update the B-mode image. For the described approach in the paper, there is no need for additional transmissions, because the excitation signal is broadband and has good spatial resolution after pulse compression. This means that time can be saved by using the same data for B-mode imaging and blood flow estimation. Two different coding schemes are used in this paper, Barker codes and Golay codes. The performance of the codes for velocity estimation is compared with a conventional approach transmitting a narrow-band pulse. The study was carried out using an experimental ultrasound scanner and a commercial linear array 7 MHz transducer. A circulating flow rig was scanned with a beam-to-flow angle of 60Â°. The flow in the rig was laminar and had a parabolic flow-profile with a peak velocity of 0.09 m/s. The mean relative standard deviation of the velocity estimate using the reference method with an 8-cycle excitation pulse at 7 MHz was 0.544% compared with the peak velocity in the rig. Two Barker codes were tested with a length of 5 and 13 bits, respectively. The corresponding mean relative standard deviations were 0.367% and 0.310%, respectively. For the Golay coded experiment, two 8-bit codes were used, and the mean relative standard deviation was 0.335%.

Gran, Fredrik; Udesen, Jesper

2008-01-01

168

Coded ultrasound for blood flow estimation using subband processing

DEFF Research Database (Denmark)

This paper investigates the use of coded excitation for blood flow estimation in medical ultrasound. Traditional autocorrelation estimators use narrow-band excitation signals to provide sufficient signal-to-noise-ratio (SNR) and velocity estimation performance. In this paper, broadband coded signals are used to increase SNR, followed by subband processing. The received broadband signal is filtered using a set of narrow-band filters. Estimating the velocity in each of the bands and averaging the results yields better performance compared with what would be possible when transmitting a narrow-band pulse directly. Also, the spatial resolution of the narrow-band pulse would be too poor for brightness-mode (B-mode) imaging, and additional transmissions would be required to update the B-mode image. For the described approach in the paper, there is no need for additional transmissions, because the excitation signal is broadband and has good spatial resolution after pulse compression. This means that time can be saved by using the same data for B-mode imaging and blood flow estimation. Two different coding schemes are used in this paper, Barker codes and Golay codes. The performance of the codes for velocity estimation is compared with a conventional approach transmitting a narrow-band pulse. The study was carried out using an experimental ultrasound scanner and a commercial linear array 7 MHz transducer. A circulating flow rig was scanned with a beam-to-flow angle of 60 degrees. The flow in the rig was laminar and had a parabolic flow-profile with a peak velocity of 0.09 m/s. The mean relative standard deviation of the velocity estimate using the reference method with an 8-cycle excitation pulse at 7 MHz was 0.544% compared with the peak velocity in the rig. Two Barker codes were tested with a length of 5 and 13 bits, respectively. The corresponding mean relative standard deviations were 0.367% and 0.310%, respectively. For the Golay coded experiment, two 8-bit codes were used, and the mean relative standard deviation was 0.335% Udgivelsesdato: 2008/10

Gran, F.; Udesen, J.

2008-01-01

169

Soil Heat Flow. Physical Processes in Terrestrial and Aquatic Ecosystems, Transport Processes.

These materials were designed to be used by life science students for instruction in the application of physical theory to ecosystem operation. Most modules contain computer programs which are built around a particular application of a physical process. Soil heat flow and the resulting soil temperature distributions have ecological consequences…

Simpson, James R.

170

Transient processes in turbulent dissociating coolant flow in a pipeline

International Nuclear Information System (INIS)

Mathematical models are proposed to investigate transient processes in the flow of turbulent dissociating coolant N2O4 reversible 2NO2 reversible 2NO+O2 in a pipeline. The models are obtained on the basis of the conservation equation with utillization of the Reyhardt model of turbulant exchange. The investigation of the transient processes has beeen conducted by way of numerical solution on the BESM-6 computer for linear variation in time of wall temperature and inlet gas with different velocities. The results for mid-mass value of the parameters have been compared with the computation according to one-dimensional model which is common practice in engineer experience. It is shown that the possibility of one-dimensional model utilization depends on the velocity and the values of parameter variations. Considerable difference of the transient value of the Nu number from the stationary one is recognized with deep disturbances occuring practically momentarily

1981-01-01

171

Features, Events and Processes in UZ Flow and Transport

Energy Technology Data Exchange (ETDEWEB)

The purpose of this report is to evaluate and document the inclusion or exclusion of the unsaturated zone (UZ) features, events, and processes (FEPs) with respect to modeling that supports the total system performance assessment (TSPA) for license application (LA) for a nuclear waste repository at Yucca Mountain, Nevada. A screening decision, either Included or Excluded, is given for each FEP, along with the technical basis for the screening decision. This information is required by the U.S. Nuclear Regulatory Commission (NRC) in 10 CFR 63.114 (d, e, and f) [DIRS 173273]. The FEPs deal with UZ flow and radionuclide transport, including climate, surface water infiltration, percolation, drift seepage, and thermally coupled processes. This analysis summarizes the implementation of each FEP in TSPA-LA (that is, how the FEP is included) and also provides the technical basis for exclusion from TSPA-LA (that is, why the FEP is excluded). This report supports TSPA-LA.

P. Persoff

2005-08-04

172

Features, Events, and Processes in UZ Flow and Transport

International Nuclear Information System (INIS)

The purpose of this report is to evaluate and document the inclusion or exclusion of the unsaturated zone (UZ) features, events, and processes (FEPs) with respect to modeling that supports the total system performance assessment (TSPA) for license application (LA) for a nuclear waste repository at Yucca Mountain, Nevada. A screening decision, either ''Included'' or ''Excluded'', is given for each FEP, along with the technical basis for the screening decision. This information is required by the U.S. Nuclear Regulatory Commission (NRC) in 10 CFR 63.114 (d, e, and f) [DIRS 156605]. The FEPs deal with UZ flow and radionuclide transport, including climate, surface water infiltration, percolation, drift seepage, and thermally coupled processes. This analysis summarizes the implementation of each FEP in TSPA-LA (that is, how the FEP is included) and also provides the technical basis for exclusion from TSPA-LA (that is, why the FEP is excluded). This report supports TSPA-LA

2004-01-01

173

Features, Events and Processes in UZ Flow and Transport

International Nuclear Information System (INIS)

The purpose of this report is to evaluate and document the inclusion or exclusion of the unsaturated zone (UZ) features, events, and processes (FEPs) with respect to modeling that supports the total system performance assessment (TSPA) for license application (LA) for a nuclear waste repository at Yucca Mountain, Nevada. A screening decision, either Included or Excluded, is given for each FEP, along with the technical basis for the screening decision. This information is required by the U.S. Nuclear Regulatory Commission (NRC) in 10 CFR 63.114 (d, e, and f) [DIRS 173273]. The FEPs deal with UZ flow and radionuclide transport, including climate, surface water infiltration, percolation, drift seepage, and thermally coupled processes. This analysis summarizes the implementation of each FEP in TSPA-LA (that is, how the FEP is included) and also provides the technical basis for exclusion from TSPA-LA (that is, why the FEP is excluded). This report supports TSPA-LA

2005-01-01

174

On the conversion of ordinary Voronoi diagrams into Laguerre diagrams

DEFF Research Database (Denmark)

We present some geometric relationships between the ordinary Voronoi diagram, and the Voronoi diagram in the Laguerre geometry. We derive from these proper- ties an algorithm for the conversion of ordinary Voronoi diagrams into Voronoi diagrams in the Laguerre geom- etry.

Anton, FranÃ§ois; Mioc, Darka

1999-01-01

175

Modelling of energy flows in potato crisp frying processes

International Nuclear Information System (INIS)

Food frying is very energy intensive and in industrial potato crisp production lines frying is responsible for more than 90% of the total energy consumption of the process. This paper considers the energy flows in crisp frying using a First Law of Thermodynamics modelling approach which was verified against data from a potato crisp production line. The results indicate that for the frying process considered, most of the energy used is associated with the evaporation of water present in the potato and on the surface of potato slices. The remainder is from evaporation of frying oil and air of the ventilation system and heat losses from the fryer wall surfaces by convection and radiation. The frying oil is heated by an industrial gas furnace and the efficiency of this process was calculated to be 84%. The efficiency of the overall frying process which was found to be of the order of 70% can be improved by employing exhaust heat recovery and optimising other operating and control parameters such as exhaust gas recirculation.

2012-01-01

176

Processes | Special Issue : Design and Engineering of Microreactor and Smart-Scaled Flow Processes

...units has established and supplemented the numbering-up concept (parallelization of microchannels/-reactors operated under equal conditions). New innovations and enabling technologies ...Open Access Article: Rapid Determination of Optimal Conditions in a Continuous Flow Reactor Using Process Analytical Technology by Michael F. Roberto, Thomas ...Hide Abstract | Download PDF Full-text (609 KB) | Download XML Full-text Abstract: Continuous flow reactors (CFRs) are an emerging technology that offer several advantages ... CFR reproducibility can be attributed to the reactors achieving and maintaining a steady state once all physical and chemical conditions have stabilized. ...

177

Engineered Barrier System Degradation, Flow, and Transport Process Model Report

Energy Technology Data Exchange (ETDEWEB)

The Engineered Barrier System Degradation, Flow, and Transport Process Model Report (EBS PMR) is one of nine PMRs supporting the Total System Performance Assessment (TSPA) being developed by the Yucca Mountain Project for the Site Recommendation Report (SRR). The EBS PMR summarizes the development and abstraction of models for processes that govern the evolution of conditions within the emplacement drifts of a potential high-level nuclear waste repository at Yucca Mountain, Nye County, Nevada. Details of these individual models are documented in 23 supporting Analysis/Model Reports (AMRs). Nineteen of these AMRs are for process models, and the remaining 4 describe the abstraction of results for application in TSPA. The process models themselves cluster around four major topics: ''Water Distribution and Removal Model, Physical and Chemical Environment Model, Radionuclide Transport Model, and Multiscale Thermohydrologic Model''. One AMR (Engineered Barrier System-Features, Events, and Processes/Degradation Modes Analysis) summarizes the formal screening analysis used to select the Features, Events, and Processes (FEPs) included in TSPA and those excluded from further consideration. Performance of a potential Yucca Mountain high-level radioactive waste repository depends on both the natural barrier system (NBS) and the engineered barrier system (EBS) and on their interactions. Although the waste packages are generally considered as components of the EBS, the EBS as defined in the EBS PMR includes all engineered components outside the waste packages. The principal function of the EBS is to complement the geologic system in limiting the amount of water contacting nuclear waste. A number of alternatives were considered by the Project for different EBS designs that could provide better performance than the design analyzed for the Viability Assessment. The design concept selected was Enhanced Design Alternative II (EDA II).

E.L. Hardin

2000-07-17

178

Engineered Barrier System Degradation, Flow, and Transport Process Model Report

International Nuclear Information System (INIS)

The Engineered Barrier System Degradation, Flow, and Transport Process Model Report (EBS PMR) is one of nine PMRs supporting the Total System Performance Assessment (TSPA) being developed by the Yucca Mountain Project for the Site Recommendation Report (SRR). The EBS PMR summarizes the development and abstraction of models for processes that govern the evolution of conditions within the emplacement drifts of a potential high-level nuclear waste repository at Yucca Mountain, Nye County, Nevada. Details of these individual models are documented in 23 supporting Analysis/Model Reports (AMRs). Nineteen of these AMRs are for process models, and the remaining 4 describe the abstraction of results for application in TSPA. The process models themselves cluster around four major topics: ''Water Distribution and Removal Model, Physical and Chemical Environment Model, Radionuclide Transport Model, and Multiscale Thermohydrologic Model''. One AMR (Engineered Barrier System-Features, Events, and Processes/Degradation Modes Analysis) summarizes the formal screening analysis used to select the Features, Events, and Processes (FEPs) included in TSPA and those excluded from further consideration. Performance of a potential Yucca Mountain high-level radioactive waste repository depends on both the natural barrier system (NBS) and the engineered barrier system (EBS) and on their interactions. Although the waste packages are generally considered as components of the EBS, the EBS as defined in the EBS PMR includes all engineered components outside the waste packages. The principal function of the EBS is to complement the geologic system in limiting the amount of water contacting nuclear waste. A number of alternatives were considered by the Project for different EBS designs that could provide better performance than the design analyzed for the Viability Assessment. The design concept selected was Enhanced Design Alternative II (EDA II)

2000-01-01

179

Infiltration condition and mouldability diagram in resin injection moulding

Directory of Open Access Journals (Sweden)

Full Text Available This paper deals with the modelling of injection moulding processes taking into account the deformability of the preform and the polymerisation of the resin. The coupled flow-deformation problem in the infiltrated and dry region is formulated with the corresponding boundary conditions and with the proper evolution equations determining the motion of the boundaries. An approximated analytical discussion is performed to obtain some estimates on the infiltration velocity, helping in identifying a window of applicability in the parameters space (i.e., the mouldability diagram, which fits well with the numerical simulations.

Luca Mesin

2007-01-01

180

Features, Events, and Processes in SZ Flow and Transport

International Nuclear Information System (INIS)

This analysis report evaluates and documents the inclusion or exclusion of the saturated zone (SZ) features, events, and processes (FEPs) with respect to modeling used to support the total system performance assessment (TSPA) for license application (LA) of a nuclear waste repository at Yucca Mountain, Nevada. A screening decision, either Included or Excluded, is given for each FEP along with the technical basis for the decision. This information is required by the U.S. Nuclear Regulatory Commission (NRC) at 10 CFR 63.11(d), (e), (f) [DIRS 173273]. This scientific report focuses on FEP analysis of flow and transport issues relevant to the SZ (e.g., fracture flow in volcanic units, anisotropy, radionuclide transport on colloids, etc.) to be considered in the TSPA model for the LA. For included FEPs, this analysis summarizes the implementation of the FEP in TSPA-LA (i.e., how the FEP is included). For excluded FEPs, this analysis provides the technical basis for exclusion from TSPA-LA (i.e., why the FEP is excluded)

2005-01-01

181

Features, Events, and Processes in SZ Flow and Transport

International Nuclear Information System (INIS)

This analysis report evaluates and documents the inclusion or exclusion of the saturated zone (SZ) features, events, and processes (FEPs) with respect to modeling used to support the total system performance assessment (TSPA) for license application (LA) of a nuclear waste repository at Yucca Mountain, Nevada. A screening decision, either ''Included'' or ''Excluded'', is given for each FEP along with the technical basis for the decision. This information is required by the U.S. Nuclear Regulatory Commission (NRC) at 10 CFR 63.114 (d), (e), (f) (DIRS 156605). This scientific report focuses on FEP analysis of flow and transport issues relevant to the SZ (e.g., fracture flow in volcanic units, anisotropy, radionuclide transport on colloids, etc.) to be considered in the TSPA model for the LA. For included FEPs, this analysis summarizes the implementation of the FEP in TSPA-LA (i.e., how the FEP is included). For excluded FEPs, this analysis provides the technical basis for exclusion from TSPA-LA (i.e., why the FEP is excluded)

2004-01-01

182

Measuring information flow in networks of stochastic processes

Social networks are considered in this paper as networks of interacting stochastic processes. We study the problem of inferring the circulation of information between network nodes. To take into account feedback between signals, as well as instantaneous interaction, we show that the adequate measures of information flow are the directed information and the causal conditional directed information. We relate the framework based on directed information theory to the theory of Granger causality in multivariate time series. An important result of the paper is the proof that linear implementation of Granger causality and directed information theory are equivalent in the Gaussian case. This is proved for the bivariate analysis as well as for the multivariate analysis, for which we extend some of Geweke's results. The relations between directed information and transfer entropy are provided. A simulation illustrates the main results obtained in the paper through the problem of inferring effective connectivity in a net...

Amblard, Pierre-Olivier

2009-01-01

183

Qualitative Assessment of Flow and Transport Mechanisms in Bioremediation Processes

Recent studies suggest that time-lapse crosshole geophysical methods may be effective in monitoring subsurface hydrological and biochemical mechanisms. These methods have potential to provide a minimally invasive, cost-effective, high resolution, field relevant means to gain information previously limited to wellbore data. Our study area is located at a DOE Hanford site, an area heavily polluted with toxic chromate. Time- lapse crosshole seismic and radar data sets have been collected in order to monitor spatio-temporal responses to these processes. Before using these data for parameter estimation and monitoring hydrobiogeochemical processes, we need to 1) identify the critical parameters involved in these processes; 2) determine the sensitivity of seismic/radar responses to these parameters; and 3) choose the most appropriate forward modeling approach for forward and inverse modeling. In this study, we treat critical parameters (e.g., hydraulic conductivity, flow rate, and the dispersion coefficients) as random variables, which can be described by their probabilistic density distributions. Then we adopt stochastic sampling method within the Minimum relative entropy (MRE) framework to generate many realistic models based on the welllog data. From here, the geophysical (crosshole seismic and radar) responses are computed using different forward models to study the sensitivity of the responses to those aforementioned parameters, and the performances of the different forward modeling approaches are compared. Finally, geophysical data are used for hydrobiogeochemical parameter estimation through Bayesian inverse modeling. Our study provides guidance on favorable situations in which borehole geophysical data can be effectively used for monitoring subsurface hydrobiogeochemical processes.

Terry, N.; Hou, Z.

2008-12-01

184

Power supply - Interpretation of phase vector diagrams

International Nuclear Information System (INIS)

This article discusses the problems involved in providing real-time measurement and billing of active and reactive power for the various players in the liberalised electricity market. Large amounts of data have to be made available to various instances and meet stringent standards at the same time. The article discusses one of the factors involved, i.e. the interpretation of concatenated vector diagrams that represent active and reactive power flow. The basics of how active and reactive power are represented are presented and the conventions agreed on by the various players in the market are noted. Four-quadrant diagrams are described on the basis of an example taken from practice.

2009-01-01

185

Eigenanalysis of a neural network for optic flow processing

International Nuclear Information System (INIS)

Flies gain information about self-motion during free flight by processing images of the environment moving across their retina. The visual course control center in the brain of the blowfly contains, among others, a population of ten neurons, the so-called vertical system (VS) cells that are mainly sensitive to downward motion. VS cells are assumed to encode information about rotational optic flow induced by self-motion (Krapp and Hengstenberg 1996 Nature 384 463-6). Recent evidence supports a connectivity scheme between the VS cells where neurons with neighboring receptive fields are connected to each other by electrical synapses at the axonal terminals, whereas the boundary neurons in the network are reciprocally coupled via inhibitory synapses (Haag and Borst 2004 Nat. Neurosci. 7 628-34; Farrow et al 2005 J. Neurosci. 25 3985-93; Cuntz et al 2007 Proc. Natl Acad. Sci. USA). Here, we investigate the functional properties of the VS network and its connectivity scheme by reducing a biophysically realistic network to a simplified model, where each cell is represented by a dendritic and axonal compartment only. Eigenanalysis of this model reveals that the whole population of VS cells projects the synaptic input provided from local motion detectors on to its behaviorally relevant components. The two major eigenvectors consist of a horizontal and a slanted line representing the distribution of vertical motion components across the fly's azimuth. They are, thus, ideally suited for reliably encoding translational and rotational whole-field optic flow induced by respective flight maneuvers. The dimensionality reduction compensates for the contrast and texture dependence of the local motion detectors of the correlation-type, which becomes particularly pronounced when confronted with natural images and their highly inhomogeneous contrast distribution

2008-01-01

186

International Nuclear Information System (INIS)

This monography contains critically compiled equilibrium diagrams of binary systems of iron with all the elements of the Periodic Chart (except the halogens), updated and in an improved form (raster paper). It is based essentially on experimental data but includes the results of thermochemcial calculations where applicable. The work represents information up to the end of 1981. (GSCH)

1981-01-00

187

Multiple representations are a valuable tool to help students learn and understand physics concepts. Furthermore, representations help students learn how to think and act like real scientists. These representations include: pictures, free-body diagrams, energy bar charts, electrical circuits, and, more recently, computer simulations and…

Rosengrant, David

2011-01-01

188

Homotopy Diagrams of Algebras.

Czech Academy of Sciences Publication Activity Database

. Ro?. 69, - (2002), s. 161-180. ISSN 0009-725X.[Winter School "Geometry and Physics" /21./. Srní, 13.01.2001-20.01.2001]Grant CEP: GA ?R GA201/99/0675Klí?ová slova: colored operad%cofibrant model%homotopy diagramKód oboru RIV: BA - Obecná matematika

Markl, Martin

189

Energy Technology Data Exchange (ETDEWEB)

The report describes progress made in the various thrust areas of the project, which include internal drives for oil recovery, vapor-liquid flows, combustion and reaction processes and the flow of fluids with yield stress.

Yorstos, Yannis C.

2003-03-19

190

Fractional Flow Theory Applicable to Non-Newtonian Behavior in EOR Processes:

Digital Repository Infrastructure Vision for European Research (DRIVER)

The method of characteristics, or fractional-flow theory, is extremely useful in understanding complex Enhanced Oil Recovery (EOR) processes and in calibrating simulators. One limitation has been its restriction to Newtonian rheology except in rectilinear flow. Its inability to deal with non-Newtonian rheology in polymer and foam EOR has been a serious limitation. We extend fractional flow methods for two-phase flow to non-Newtonian fluids in one-dimensional cylindrical flow, where rheology c...

Rossen, W. R.; Venkatraman, A.; Johns, R. T.; Kibodeaux, K. R.; Lai, H.; Moradi Tehrani, N.

2011-01-01

191

We present measurements of phi-meson production and elliptic flow (v2) at mid-rapidity in Au + Au collisions at = 7.7 – 200 GeV. Energy dependence of nuclear modification factor (RCP) of phi meson is presented. The phi-meson RCP has a value >= 1.0 for pT) for = 11.5 GeV compared to higher beam energies. The number-of-constituent quark (NCQ) scaling of v2 has been studied at various beam energies. The NCQ scaling holds for particles and anti-particles separately including the phi meson for >= 19.6 GeV, which can be considered as an evidence of partonic collectivity. We observe that phi-meson v2 falls off the trend from the other hadrons at highest measured pT values by 1.8? and 2.3? at = 7.7 and 11.5 GeV, respectively.

Nasim, Md; Star Collaboration

2014-05-01

192

Variations in G.S. process flow sheet (Preprint No. PD-12)

International Nuclear Information System (INIS)

Variations have been seen in Girdler Sulfide process flow sheet as compared to the flow sheet used at HWP (Kota). These involve movement of deuterium to higher stages by gas and keeping liquid of 2nd and 3rd stages in total recirculation. Working further on these concepts a revised flow sheet for a typical exchange unit has been developed and given along with original flow sheet of HWP (KOTA) for comparison. The drawings show equipments and process control features. (author). 3 figs

1989-01-01

193

Directory of Open Access Journals (Sweden)

Full Text Available Problem statement: Building UML diagrams is a very important and time consuming task for both requirements and design phases. However, some of these diagrams, such as use-case and class diagrams can be considered as a transition between the two phases. Approach: Through this study, the event table will be used to derive the use-case and class diagrams. Results: A new CASE tool to automate the proposed approach will be introduced, that is, the UML diagrams generator (UMLdg. Conclusion: It is clearly noted that the proposed CASE tool (UMLdg gives an ideal and reasonable methodology to construct the intended use-case and class diagrams from any comprehensive event table. Furthermore, this tool will save the time for the building process of such diagrams.

Mohammad I. Muhairat

2010-01-01

194

The function design of the Input/Output (I/O) services for the Advanced Information Processing System (AIPS) proof of concept system is described. The data flow diagrams, which show the functional processes in I/O services and the data that flows among them, are contained. A complete list of the data identified on the data flow diagrams and in the process descriptions are provided.

1985-01-01

195

INDUSTRIAL PROCESS PROFILES FOR ENVIRONMENTAL USE: CHAPTER 26. TITANIUM INDUSTRY

The titanium industry produces two principal products, titanium metal and titanium dioxide. For purposes of analyses, therefore, the industry is considered in two segments: titanium metal production and titanium dioxide production. Two industrial process flow diagrams and eleven ...

196

On the Development and Usability of a Diagram-based Collaborative Brainstorming Component:

Digital Repository Infrastructure Vision for European Research (DRIVER)

The need for computer-supported collaboration has grown over the last years and made collaboration an important factor within organizations. This trend has resulted in the development of a variety of tools and technologies to support the various forms of collaboration. Many collaborative processes, e.g. strategy building, scenario analysis, root cause analysis and requirements engineering, require various collaboration support tools. Data flow, fishbone and brainstorming diagrams, play an imp...

Azevedo, D.; Fonseca, B.; Paredes, H.; Lukosch, S. G.; Janeiro Lopes Da Silva, J.; Briggs, R. O.

2013-01-01

197

Does the butterfly diagram indicate asolar flux-transport dynamo?

We address the question whether the properties of the observed latitude-time diagram of sunspot occurence (the butterfly diagram) provide evidence for the operation of a flux-transport dynamo, which explains the migration of the sunspot zones and the period of the solar cycle in terms of a deep equatorward meridional flow. We show that the properties of the butterfly diagram are equally well reproduced by a conventional dynamo model with migrating dynamo waves, but without transport of magnetic flux by a flow. These properties seem to be generic for an oscillatory and migratory field of dipole parity and thus do not permit an observational distinction between different dynamo approaches.

Schüssler, M

2004-01-01

198

An Introduction to Tree Diagrams

This brief article describes the use of tree diagrams in calculating probabilities. The author provides examples of how tree diagrams are used to calculate specific probabilities and why the language chosen relates to the operations used to find the probability.

Cork, Stu

2014-01-01

199

Pattern Recognition of Logic Diagrams.

This paper presents the development of line following and line analysis pattern recognition routines to automatically computer read hand-drawn logic diagrams. The decision criterion used was based on a tree analysis of segmented lines. The logic diagrams ...

D. A. Naegele

1973-01-01

200

DEFF Research Database (Denmark)

Some very good arguments can be given in favor of the Augustinean wisdom, according to which it is impossible to provide a satisfactory definition of the concept of time. However, even in the absence of a proper definition, it is possible to deal with conceptual problems regarding time. It can be done in terms of analogies and metaphors. In particular, it is attractive to make use of Peirce's diagrams by means of which various kinds of conceptual experimentation can be carried out. This paper investigates how Peircean diagrams can be used within the study of time. In particular, we discuss 1) the topological properties of time, 2) the implicative structure in tense logic, 3) the notions of open future and branching time models, and finally 4) tenselogical alternatives to branching time models.

Ã?hrstrÃ¸m, Peter

2011-01-01

201

We first derive a new ``commutation technique'' for an exciton interacting with electrons, inspired from the one we recently developed for excitons interacting with excitons. These techniques allow to take \\emph{exactly} into account the possible exchanges between carriers. We use it to get the $\\mathrm{X}^-$ trion creation operator in terms of exciton and free-electron creation operators. In a last part we generate the ladder diagrams associated to these trions. Although similar to the exciton ladder diagrams, with the hole replaced by an exciton, they are actually much more tricky : (i) Due to the composite nature of the exciton, one cannot identify an exciton-electron potential similar to the Coulomb potential between electron and hole ; (ii) the spins are unimportant for excitons while they are crucial for trions, singlet and triplet states having different energies.

Combescot, M

2002-01-01

202

Compressing Binary Decision Diagrams

DEFF Research Database (Denmark)

The paper introduces a new technique for compressing Binary Decision Diagrams in those cases where random access is not required. Using this technique, compression and decompression can be done in linear time in the size of the BDD and compression will in many cases reduce the size of the BDD to 1-2 bits per node. Empirical results for our compression technique are presented, including comparisons with previously introduced techniques, showing that the new technique dominate on all tested instances

Hansen, Esben Rune; Satti, Srinivasa Rao

2008-01-01

203

Digital Repository Infrastructure Vision for European Research (DRIVER)

In [math.AT/9907138] we proved that strongly homotopy algebras are homotopy invariant concepts in the category of chain complexes. Our arguments were based on the fact that strongly homotopy algebras are algebras over minimal cofibrant operads and on the principle that algebras over cofibrant operads are homotopy invariant. In our approach, algebraic models for colored operads describing diagrams of homomorphisms played an important role. The aim of this paper is to give a...

Markl, Martin

2001-01-01

204

Processes of hydrodynamics and heat exchange in descending bubble flows

International Nuclear Information System (INIS)

This paper examines the gas content, hydraulic resistance, heat transfer, and structure of descending bubble flows in the regimes of concurrent flow and of hovering of the gas phase. A comparison of the data on hydraulic resistance and on heat transfer reveals their qualitative similarity

1986-02-01

205

Power diagrams and their applications

We remark that the power diagrams from computer science are the spines of amoebas in algebraic geometry, or the hypersurfaces in tropical geometry. Our concept of a Morse poset generalizes to power diagrams. We show that there exists a discrete Morse function on the coherent triangulation, dual to the power diagram, such that its critical set equals the Morse poset of the power diagram. In the final section we use Maslov dequantization to compute the medial axis.

van Manen, M; Manen, Martijn van; Siersma, Dirk

2005-01-01

206

Supporting UML Sequence Diagrams with a Processor Net Approach

Digital Repository Infrastructure Vision for European Research (DRIVER)

UML sequence diagrams focus on the interaction between different classes. For distributed real time transaction processing it is possible to end up with complex sequence diagrams, containing messages related to system processes. It is difficult to examine alternative combinations of message passing. A...

Tony Spiteri Staines

2007-01-01

207

Generalized performance diagrams for steam turbine systems

International Nuclear Information System (INIS)

Two generalized diagrams have been prepared for the steam turbine performance estimate. The diagrams can predict the turbine net heat rate for various turbine exhaust pressures and loadings. The turbine systems covered in these diagrams have the steam conditions either supercritical or subcritical, and the power output in the range of 400,000 kW to 800,000 kW. The turbine has 4 or 6 exhaust flows and the last stage blade length 23, 26, 30 or 33.5 inches. The basic approach is to normalize the turbine heat rates and express them in terms of turbine heat rates and express them in terms of turbine output per unit area of exhaust flow. The turbine exhaust pressure is treated as a parameter. Approximately 30 steam turbine system have been simulated by computer and the performance data were utilized in the construction of the generalized diagrams. The values predicted by this approach are in good agreement with the actual data

1986-01-01

208

Influence diagram in evaluating the subjective judgment

International Nuclear Information System (INIS)

The author developed the idea of the subjective influence diagrams to evaluate subjective judgment. The subjective judgment of a stake holder is a primary decision making proposition. It involves a basic decision process an the individual attitude of the stake holder for his decision purpose. The subjective judgment dominates the some final decisions. A complex decision process may include the subjective judgment. An influence diagram framework is a simplest tool for analyzing subjective judgment process. In the framework, the characters of influence diagrams generate the describing the analyzing, and the evaluating of the subjective judgment. The relationship between the information and the decision, such as independent character between them, is the main issue. Then utility function is the calculating tool to evaluation, the stake holder can make optimal decision. Through the analysis about the decision process and relationship, the building process of the influence diagram identically describes the subjective judgment. Some examples are given to explain the property of subjective judgment and the analysis process

1997-04-14

209

Computational Fluid Dynamics (CFD) simulations can be very computationally expensive, especially for Large Eddy Simulations (LES) and Direct Numerical Simulations (DNS) of turbulent ows. In LES the large, energy containing eddies are resolved by the computational mesh, but the smaller (sub-grid) scales are modeled. In DNS, all scales of turbulence are resolved, including the smallest dissipative (Kolmogorov) scales. Clusters of CPUs have been the standard approach for such simulations, but an emerging approach is the use of Graphics Processing Units (GPUs), which deliver impressive computing performance compared to CPUs. Recently there has been great interest in the scientific computing community to use GPUs for general-purpose computation (such as the numerical solution of PDEs) rather than graphics rendering. To explore the use of GPUs for CFD simulations, an incompressible Navier-Stokes solver was developed for a GPU. This solver is capable of simulating unsteady laminar flows or performing a LES or DNS of turbulent ows. The Navier-Stokes equations are solved via a fractional-step method and are spatially discretized using the finite volume method on a Cartesian mesh. An immersed boundary method based on a ghost cell treatment was developed to handle flow past complex geometries. The implementation of these numerical methods had to suit the architecture of the GPU, which is designed for massive multithreading. The details of this implementation will be described, along with strategies for performance optimization. Validation of the GPU-based solver was performed for fundamental bench-mark problems, and a performance assessment indicated that the solver was over an order-of-magnitude faster compared to a CPU. The GPU-based Navier-Stokes solver was used to study film-cooling flows via Large Eddy Simulation. In modern gas turbine engines, the film-cooling method is used to protect turbine blades from hot combustion gases. Therefore, understanding the physics of this problem as well as techniques to improve it is important. Fundamentally, a film-cooling configuration is an inclined cooling jet in a hot cross-flow. A known problem in the film-cooling method is jet lift-off, where the jet of coolant moves away from the surface to be cooled due to mutual vortex induction by the counter-rotating vortex pair embedded in the jet, resulting in decreased cooling at the surface. To counteract this, a micro-ramp vortex generator was added downstream of the film-cooling jet, which generated near-wall counter-rotating vortices of opposite sense to the vortex pair in the jet. It was found that the micro-ramp vortices created a downwash effect toward the wall, which helped entrain coolant from the jet and transport it to the wall, resulting in better cooling. Results are reported using two film-cooling configurations, where the primary difference is the way the jet exit boundary conditions are prescribed. In the first configuration, the jet is prescribed using a precursor simulation and in the second the jet is modeled using a plenum/pipe configuration. The latter configuration was designed based on previous wind tunnel experiments at NASA Glenn Research Center, and the present results were meant to supplement those experiments.

Shinn, Aaron F.

210

Evolution of Plastic Strain During a Flow Forming Process

The distribution of equivalent plastic strain through the thickness of several AISI 1020 steel plates formed under different conditions over a smooth cylindrical mandrel using a single-roller forward flow forming operation was studied by measuring the local micro-indentation hardness of the deformed material. The equivalent plastic strain was higher at the inner and outer surfaces and lowest at the center of the workpiece. Empirical expressions are presented which describe the contribution of the roller and mandrel to the total local equivalent plastic strain within the flow formed part. The dependence of these expressions upon the thickness reduction during flow forming is discussed.

Roy, M J; Wood, J T; 10.1016/j.jmatprotec.2008.03.030

2011-01-01

211

Voronoi diagrams on the sphere

Digital Repository Infrastructure Vision for European Research (DRIVER)

Given a set of compact sites on a sphere, we show that their spherical Voronoi diagram can be computed by computing two planar Voronoi diagrams of suitably transformed sites in the plane. We also show that a planar furthest-site Voronoi diagram can always be obtained as a portion of a nearest-site Voronoi diagram of a set of transformed sites. Two immediate applications are an O(nlog n) algorithm for the spherical Voronoi diagram of a set of circular arcs on the sphere, and an ...

Na, H. -s; Lee, C. -n; Cheong, O.

2001-01-01

212

Simulation of fluid flow system in process industries

Digital Repository Infrastructure Vision for European Research (DRIVER)

A comprehensive and integrated suite of computer software has been developed to simulate the steady, one-dimensional, incompressible fluid flow in pipeline networks. The computer program accommodates Newtonian liquids, but does not generally apply to gas flow unless the assumption of constant density is acceptable. The computer program is written in C language, to solve the basic pipe system equations using the linear theory method. This computer program is written to analyse steady state...

Khamkham, Nasser E.

2000-01-01

213

Identification of the molten glass flow process in tank furnaces

International Nuclear Information System (INIS)

A mathematical model for the evaluation of flow dynamics of molten glass within a tank furnace has been developed. The technological and dynamical parameters were obtained for an industrial and a model tank furnace using "1"4"0La as a tracer. The results are in good agreement with theoretical values computed on the basis of a complex flow model (Wolf-Resnick model) with the aid of the MARMOD code

1986-01-01

214

Equivalent Temperature-Enthalpy Diagram for the Study of Ejector Refrigeration Systems

Directory of Open Access Journals (Sweden)

Full Text Available The Carnot factor versus enthalpy variation (heat diagram has been used extensively for the second law analysis of heat transfer processes. With enthalpy variation (heat as the abscissa and the Carnot factor as the ordinate the area between the curves representing the heat exchanging media on this diagram illustrates the exergy losses due to the transfer. It is also possible to draw the paths of working fluids in steady-state, steady-flow thermodynamic cycles on this diagram using the definition of “the equivalent temperature” as the ratio between the variations of enthalpy and entropy in an analyzed process. Despite the usefulness of this approach two important shortcomings should be emphasized. First, the approach is not applicable for the processes of expansion and compression particularly for the isenthalpic processes taking place in expansion valves. Second, from the point of view of rigorous thermodynamics, the proposed ratio gives the temperature dimension for the isobaric processes only. The present paper proposes to overcome these shortcomings by replacing the actual processes of expansion and compression by combinations of two thermodynamic paths: isentropic and isobaric. As a result the actual (not ideal refrigeration and power cycles can be presented on equivalent temperature versus enthalpy variation diagrams. All the exergy losses, taking place in different equipments like pumps, turbines, compressors, expansion valves, condensers and evaporators are then clearly visualized. Moreover the exergies consumed and produced in each component of these cycles are also presented. The latter give the opportunity to also analyze the exergy efficiencies of the components. The proposed diagram is finally applied for the second law analysis of an ejector based refrigeration system.

Mohammed Khennich

2014-05-01

215

Perturbative Results Without Diagrams

Higher-order perturbative calculations in Quantum (Field) Theory suffer from the factorial increase of the number of individual diagrams. Here I describe an approach which evaluates the total contribution numerically for finite temperature from the cumulant expansion of the corresponding observable followed by an extrapolation to zero temperature. This method (originally proposed by Bogolyubov and Plechko) is applied to the calculation of higher-order terms for the ground-state energy of the polaron. Using state-of-the-art multidimensional integration routines 2 new coefficients are obtained corresponding to a 4- and 5-loop calculation.

Rosenfelder, R

2007-01-01

216

International Nuclear Information System (INIS)

Methods for computing loop diagrams in confined scalar and gauge theories are developed. We construct propagators with different types of boundary conditions in boxes (rectangular cavities) using the method of image charges, which allows for a separation of the short-distance singularities. The techniques are illustrated by a calculation of the Casimir effect in a box using a covariant gauge, and of the energy shift of a photon in confined scalar QED. The relevance of such a calculation for a proposed model for the QCD vacuum is discussed

1982-07-15

217

Stochastic Modelling of Shiroro River Stream flow Process

Directory of Open Access Journals (Sweden)

Full Text Available Economists, social scientists and engineers provide insights into the drivers of anthropogenic climate change and the options for adaptation and mitigation, and yet other scientists, including geographers and biologists, study the impacts of climate change. This project concentrates mainly on the discharge from the Shiroro River. A stochastic approach is presented for modeling a time series by an Autoregressive Moving Average model (ARMA. The development and use of a stochastic stream flow model involves some basic steps such as obtain stream flow record and other information, Selecting models that best describes the marginal probability distribution of flows. The flow discharge of about 22 years (1990-2011 was gotten from the Meteorological Station at Shiroro and analyzed with three different models namely; Autoregressive (AR model, Autoregressive Moving Average (ARMA model and Autoregressive Integrated Moving Average (ARIMA model. The initial model identification is done by using the autocorrelation function (ACF and partial autocorrelation function (PACF. Based on the model analysis and evaluations, proper predictions for the effective usage of the flow from the river for farming activities and generation of power for both industrial and domestic us were made. It also highlights some recommendations to be made to utilize the possible potentials of the river effectively

Musa, J. J

2013-01-01

218

We encode the genealogy of a continuous-state branching process associated with a branching mechanism $\\Psi$ - or $\\Psi$-CSBP in short - using a stochastic flow of partitions. This encoding holds for all branching mechanisms and appears as a very tractable object to deal with asymptotic behaviours and convergences. In particular we study the so-called Eve property - the existence of an ancestor from which the entire population descends asymptotically - and give a necessary and sufficient condition on the $\\Psi$-CSBP for this property to hold. Finally, we show that the flow of partitions unifies the lookdown representation and the flow of subordinators when the Eve property holds.

Labbé, Cyril

2012-01-01

219

Sn60Pb40 solder powders produced by the planar flow casting atomization process

Digital Repository Infrastructure Vision for European Research (DRIVER)

Conventional planar flow casting (PFC) is one of rapid solidification processes for the fabrication of microcrystalline or amorphous ribbons. Based on the conventional PFC process, the planar flow casting atomization (PFCA) process has been developed, which is a new rapid solidification process for the production of metal powder directly from alloy melts. A prototype experimental apparatus was designed and manufactured. With the apparatus, Sn60Pb40 alloy solder powders were prepared, and the ...

2011-01-01

220

Flow regulation of variable feed pressure stream: process and device

International Nuclear Information System (INIS)

The stream is separated into a main stream and a coaxial control stream. The control stream is formed into a vortex in which the rotational axis is parallel to the flow direction of the main stream. The control stream vortex is directed towards the main stream to ensure the regulation of the fluid flow by direct interaction of the two streams. The device comprises a central tube with perforated plates around it. A structure, through which thin and straight pipes pass, and a cylindrical envelope including outlet pipes inclined with regard to the radial direction of the envelope are set in the central tube. The invention applies, more particularly, to the regulation of the liquid sodium flow rate in the used assemblies of a fast neutron nuclear reactor, during their cooling storage in the reactor vessel

1983-12-09

221

Influence diagrams for contextual information retrieval

Digital Repository Infrastructure Vision for European Research (DRIVER)

The purpose of contextual information retrieval is to make some exploration towards designing user specific search engines that are able to adapt the retrieval model to the variety of differences on user's contexts. In this paper we propose an influence diagram based retrieval model which is able to incorporate contexts, viewed as user's long-term interests into the retrieval process.

Tamine-lechani, Lynda; Boughanem, Mohand

2006-01-01

222

We consider the sum of planar diagrams for open strings propagating on N D3-branes and show that it can be recast as the propagation of a closed string with a Hamiltonian H = H_0 - g_s N P where H_0 is the free Hamiltonian and P is the hole or loop insertion operator. We compute explicitly P and study its properties. When the distance y to the D3-branes is much larger than the string length, y >> l_s, small holes dominate and H becomes a supersymmetric Hamiltonian describing the propagation of a closed string in the full D3-brane supergravity background in a particular gauge that we call sigma-gauge. At strong coupling, g_s N >> 1, there is a region 1 << y << (g_sN)^(1/4) where H is a supersymmetric Hamiltonian describing the propagation of closed strings in AdS_5xS^5. We emphasize that both results follow from the open string planar diagrams without any reference to the existence of a D3-brane supergravity background. A by-product of our analysis is a closed form for the scattering of a generic c...

Kruczenski, M

2008-01-01

223

Modeling field scale unsaturated flow and transport processes

International Nuclear Information System (INIS)

The scales of concern in subsurface transport of contaminants from low-level radioactive waste disposal facilities are in the range of 1 to 1,000 m. Natural geologic materials generally show very substantial spatial variability in hydraulic properties over this range of scales. Such heterogeneity can significantly influence the migration of contaminants. It is also envisioned that complex earth structures will be constructed to isolate the waste and minimize infiltration of water into the facility. The flow of water and gases through such facilities must also be a concern. A stochastic theory describing unsaturated flow and contamination transport in naturally heterogeneous soils has been enhanced by adopting a more realistic characterization of soil variability. The enhanced theory is used to predict field-scale effective properties and variances of tension and moisture content. Applications illustrate the important effects of small-scale heterogeneity on large-scale anisotropy and hysteresis and demonstrate the feasibility of simulating two-dimensional flow systems at time and space scales of interest in radioactive waste disposal investigations. Numerical algorithms for predicting field scale unsaturated flow and contaminant transport have been improved by requiring them to respect fundamental physical principles such as mass conservation. These algorithms are able to provide realistic simulations of systems with very dry initial conditions and high degrees of heterogeneity. Numerical simulation of the movement of water and air in unsaturated soils has demonstrated the importance of air pathways for contaminant transport. The stochastic flow and transport theory has been used to develop a systematic approach to performance assessment and site characterization. Hypothesis-testing techniques have been used to determine whether model predictions are consistent with observed data

1994-01-01

224

Overview of the FAF3 Freight Flow Matrix Construction Process

Energy Technology Data Exchange (ETDEWEB)

PROJECT DESCRIPTION The FAF3 is a FHWA freight data product which provides a national O-D matrix of commodity flows to, from, and within the United States. FAF3 freight flows are reported in terms of both annual tons and annual dollars of freight moved by mode of transportation. Based largely on the 2007 CFS, FAF3 utilizes domestic freight flow characteristics, geographic regions, and the SCTG commodity coding system from CFS. However, many freight flows were not captured by the 2007 CFS due to scope and sample size limitations. Approximately 100,000 establishments were sampled out of some 754,000 freight moving establishments in 2007 and imports are out of scope entirely. To estimate missing data values, the approach taken in FAF3 was to use a combination of a novel Log-linear modeling approach (LLM) with an iterative proportional fitting (IPF) routine that also uses additional data inputs to fill in the missing pieces. The complete FAF3 O-D Commodity Mode database is made up of 131 Origins x 131 Destinations x 43 Commodity Classes x 8 Modal categories, for annual tons and dollars. This poster illustrates how the 2007 CFS data were integrated with several additional data sources using LLM and IPF to create a comprehensive FAF3 national freight flow matrix. More detailed documentation on the sources and methods utilized in the development of FAF3 are available from the FHWA website at the following website: http://www.ops.fhwa.dot. gov/freight/freight_analysis/faf/index.htm.

Sprung, Michael J [ORNL; Southworth, Frank [ORNL; Davidson, Diane [ORNL; Hwang, Ho-Ling [ORNL; Peterson, Bruce E [ORNL; Chin, Shih-Miao [ORNL; Vogt, David P [ORNL; Li, Jan-Mou [ORNL

2011-01-01

225

Influence of Processing Parameters on the Flow Path in Friction Stir Welding

Friction stir welding (FSW) is a solid phase welding process that unites thermal and mechanical aspects to produce a high quality joint. The process variables are rpm, translational weld speed, and downward plunge force. The strain-temperature history of a metal element at each point on the cross-section of the weld is determined by the individual flow path taken by the particular filament of metal flowing around the tool as influenced by the process variables. The resulting properties of the weld are determined by the strain-temperature history. Thus to control FSW properties, improved understanding of the processing parameters on the metal flow path is necessary.

Schneider, J. A.; Nunes, A. C., Jr.

2006-01-01

226

Extended sequence diagram for human system interaction

Energy Technology Data Exchange (ETDEWEB)

Unified Modeling Language (UML) is a modeling language in the field of object oriented software engineering. The sequence diagram is a kind of interaction diagram that shows how processes operate with one another and in what order. It is a construct of a message sequence chart. It depicts the objects and classes involved in the scenario and the sequence of messages exchanged between the objects needed to carry out the functionality of the scenario. This paper proposes the Extended Sequence Diagram (ESD), which is capable of depicting human system interaction for nuclear power plants, as well as cognitive process of operators analysis. In the conventional sequence diagram, there is a limit to only identify the activities of human and systems interactions. The ESD is extended to describe operators' cognitive process in more detail. The ESD is expected to be used as a task analysis method for describing human system interaction. The ESD can also present key steps causing abnormal operations or failures and diverse human errors based on cognitive condition.

Hwang, Jong Rok; Choi, Sun Woo; Ko, Hee Ran; Kim, Jong Hyun [KEPCO International Nuclear Graduate School, Ulsan (Korea, Republic of)

2012-10-15

227

FPGA Implementations of Ladder Diagrams

Directory of Open Access Journals (Sweden)

Full Text Available The performance of programmable logic controllers is often constrained by the microprocessor and the real-time firmware of the controller. Field programmable gate arrays (FPGAs are an attractive potential implementation medium for high-speed control because of their fast and parallel execution and programmable nature. Ladder Diagrams are a standard graphical programming method for industrial controllers, but compilers from Ladder Diagrams to FPGA hardware do not yet exist. This paper explores the comparative speed of four different classes of FGPA implementation of Ladder Diagrams - Interpreted Software, Compiled Software, Interpreted Hardware and Compiled Hardware. It also explores parallel versus serial execution of Ladder Diagrams in hardware, and identifies timers as a major resource user in parallel implementations. Overall, a Shared Timer Serial Compiled Hardware system for FPGA implementation of Ladder Diagrams is recommended. Using comparable FPGA resources to other alternatives it provides a 20-600 times speed improvement over other solutions whilst maintaining correct Ladder Diagram semantics.

Neil William Bergmann

2013-02-01

228

Studies on statics of 1 exstraction of Purex process. Low-acid flow sheet

International Nuclear Information System (INIS)

A steady-state of 16-stage countercurrent extraction process has been studied for the system UO_2(NO_3)_2 - Pu(NO_3)_4 - HNO_3/30% TBP. Three various methods were used for the determination of concentration profiles: experimental, graphical (diagrams X-Y of McCabe-Thiele type) and analytical (an adapted form of Groenier's computer program SEPHIS). Using the computer method, a circulation and accumulation of plutonium was studied as a function of solvent loading with uranium and plutonium and of the feed solution acidity. (author)

1977-01-01

229

Simulations of ductile flow in brittle material processing

Energy Technology Data Exchange (ETDEWEB)

Research is continuing on the effects of thermal properties of the cutting tool and workpiece on the overall temperature distribution. Using an Eulerian finite element model, diamond and steel tools cutting aluminum have been simulated at various, speeds, and depths of cut. The relative magnitude of the thermal conductivity of the tool and the workpiece is believed to be a primary factor in the resulting temperature distribution in the workpiece. This effect is demonstrated in the change of maximum surface temperatures for diamond on aluminum vs. steel on aluminum. As a preliminary step toward the study of ductile flow in brittle materials, the relative thermal conductivities of diamond on polycarbonate is simulated. In this case, the maximum temperature shifts from the rake face of the tool to the surface of the machined workpiece, thus promoting ductile flow in the workpiece surface.

Luh, M.H.; Strenkowski, J.S.

1988-12-01

230

Generating function for web diagrams

We present the description of the exponentiated diagrams in terms of generating function within the universal diagrammatic technique. In particular, we show the exponentiation of the gauge theory amplitudes involving products of arbitrary number of Wilson lines of arbitrary shapes, which generalizes the concept of web diagrams. The presented method gives a new viewpoint on the web diagrams and proves the non-Abelian exponentiation theorem.

Vladimirov, A A

2014-01-01

231

Phase Diagram in Manganese Oxides

Digital Repository Infrastructure Vision for European Research (DRIVER)

We study theoretically the phase diagram of perovskite manganites taking into account the double degeneracy of the $e_g$ orbitals in a $Mn^{3+}$ ion. A rich phase diagram is obtained in the mean field theory at zero temperature as functions of $x$ (hole concentration) and $J_S$ (antiferromagnetic interaction between $t_{2g}$ spins). The global features of the phase diagram is understood in terms of the superexchange and double exchange interactions, which are strongly depend...

Maezono, Ryo; Ishihara, Sumio; Nagaosa, Naoto

1998-01-01

232

Hyperbolic Voronoi diagrams made easy

Digital Repository Infrastructure Vision for European Research (DRIVER)

We present a simple framework to compute hyperbolic Voronoi diagrams of finite point sets as affine diagrams. We prove that bisectors in Klein's non-conformal disk model are hyperplanes that can be interpreted as power bisectors of Euclidean balls. Therefore our method simply consists in computing an equivalent clipped power diagram followed by a mapping transformation depending on the selected representation of the hyperbolic space (e.g., Poincar\\'e conformal disk or upper-...

Nielsen, Frank; Nock, Richard

2009-01-01

233

Degeneracy of Angular Voronoi Diagram

Digital Repository Infrastructure Vision for European Research (DRIVER)

Angular Voronoi diagram was introduced by Asano et al. as fundamental research for a mesh generation. In an angular Voronoi diagram, the edges are curves of degree three. From view of computational robustness we need to treat the curves carefully, because they might have a singularity. We enumerate all the possible types of curves that appear as an edge of an angular Voronoi diagram, which tells us what kind of degeneracy is possible and tells us necessity of considering a...

Muta, Hidetoshi; Kato, Kimikazu

2007-01-01

234

Erosion due to high flow velocities: A description of relevant processes:

Digital Repository Infrastructure Vision for European Research (DRIVER)

Convential models for the erosion of non-cohesive sediments overestimate the erosion rate induced by high flow velocities. These high flow velocities occur, for instance, in breaching of embankments or dunes (flow velocities up to 10 m/s) or in jetting sand with a trailing suction hopper dredger (30 to 60 m/s). At these very large flow velocities the erosion process is significantly influenced by the properties of the soil mass (non-cohesive particles). Governing parameters at higher flow vel...

Bisschop, F.; Visser, P. J.; Rhee, C.; Verhagen, H. J.

2010-01-01

235

Feynman Diagrams and Rooted Maps

The {\\em Rooted Maps Theory}, a branch of the Theory of Homology, is shown to be a powerful tool for investigating the topological properties of Feynman diagrams, related to the single particle propagator in the quantum many-body systems. The numerical correspondence between the number of this class of Feynman diagrams as a function of perturbative order and the number of rooted maps as a function of the number of edges is studied. A graphical procedure to associate Feynman diagrams and rooted maps is then stated. Finally, starting from rooted maps principles, an original definition of the {\\em genus of a Feynman diagram}, which totally differs from the usual one, is given.

Prunotto, A; Czerski, P

2013-01-01

236

Heat flow calorimeter for data-oriented process development

Energy Technology Data Exchange (ETDEWEB)

The implementation of more precise process optimization methods has increased the demand of accurate process data. As a rule the process data required for the production of fine chemicals cannot be found in the standard reference literature; they therefore have to be determined experimentally. This paper presents an automated laboratory reactor system; though it is primarily designed for thermal data acquisition it is also well suited for the determination of other physical parameters (e.g. vapor pressure, vapor-liquid equilibrium, solubility).

Giger, G.; Aichert, A.; Regenass, W.

1982-01-01

237

Modeling of Gas Flows in Steelmaking Decarburization Processes

Digital Repository Infrastructure Vision for European Research (DRIVER)

The purpose of the current study is to increase the understanding of different steelmaking processes at the decarburization stages by use of mathematical modeling. More specifically, two De-Laval nozzles from a VOD (Vaccum Oxygen Decarburization) process, which is used for producing stainless steels with ultra-low carbon grades, was investigated for different vessel pressures. Moreover, the post combustion phenomena in a BOF or LD (Linz-Donawitz) process as well as an AOD (Argon Oxygen Decarb...

Song, Zhili Jack

2013-01-01

238

Novel Process Windows for Enabling, Accelerating, and Uplifting Flow Chemistry

Digital Repository Infrastructure Vision for European Research (DRIVER)

Novel Process Windows make use of process conditions that are far from conventional practices. This involves the use of high temperatures, high pressures, high concentrations (solvent-free), new chemical transformations, explosive conditions, and process simplification and integration to boost synthetic chemistry on both the laboratory and production scale. Such harsh reaction conditions can be safely reached in microstructured reactors due to their excellent transport intensification propert...

Hessel, Volker; Kralisch, Dana; Kockmann, Norbert; Noel, Timothy; Wang, Qi

2013-01-01

239

Comparison of Inflation Processes at the 1859 Mauna Loa Flow, HI, and the McCartys Flow Field, NM

Basaltic lavas typically form channels or tubes during flow emplacement. However, the importance of sheet flow in the development of basalt ic terrains received recognition over the last 15 years. George Walke r?s research on the 1859 Mauna Loa Flow was published posthumously in 2009. In this paper he discusses the concept of endogenous growth, or inflation, for the distal portion of this otherwise channeldominated lava flow. We used this work as a guide when visiting the 1859 flow to help us better interpret the inflation history of the McCartys flow field in NM. Both well preserved flows display similar clues about the process of inflation. The McCartys lava flow field is among the you ngest (approx.3000 yrs) basaltic lava flows in the continental United States. It was emplaced over slopes of processes is responsible for polygonal terrains, and it is po ssible that one explanation is not the sole cause of this morphology between all inflated flows. Often, these smooth surfaces within an inflated sheet display lineated surfaces and occasional squeeze-ups alon g swale contacts. We interpret the lineations to preserve original fl ow direction and have begun mapping these orientations to better interpret the emplacement history. At the scale of 10s to 100s of meters t he flow comprises multiple topographic plateaus and depressions. Some depressions display level floors with surfaces as described above, while some are bowl shaped with floors covered in broken lava slabs. Th e boundaries between plateaus and depressions are also typically smoo th, grooved surfaces that have been tilted to angles sometimes approaching vertical. The upper margin of these tilted surfaces displays lar ge cracks, sometimes containing squeeze-ups. The bottom boundary with smooth floored depressions typically shows embayment by younger lavas. It appears that this style of terrain represents the emplacement of an extensive sheet that experiences inflation episodes within prefer red regions where lateral spreading of the sheet is inhibited, thereby forming plateaus. Depressions are often the result of non-inflation and can be clearly identified by lateral squeeze-outs along the pit walls that form when the rising crust exposes the still liquid core of the sheet. Our current efforts are focused on.

Bleacher, Jacob E.; Garry, W. Brent; Zimbelman, James R.; Crumpler, Larry S.

2012-01-01

240

Supporting UML Sequence Diagrams with a Processor Net Approach

Directory of Open Access Journals (Sweden)

Full Text Available UML sequence diagrams focus on the interaction between different classes. For distributed real time transaction processing it is possible to end up with complex sequence diagrams, containing messages related to system processes. It is difficult to examine alternative combinations of message passing. A solution is to translate these diagrams into an executable processor net model. This is based on the ‘actor model’, Petri net concepts and higher order net constructs. A case study taken from a flight reservation scenario is introduced and used to create a processor net model. This approach offers various advantages like identifying the main processes, executable model creation, verification, formalization, defining schemas and performance analysis.

Tony Spiteri Staines

2007-08-01

241

International Nuclear Information System (INIS)

Highlights: ? The optimality in both heat and fluid flow systems has been investigated. ? A new thermodynamic property has been introduced. ? The second law of thermodynamics was extended to present the temheat balance that included the temheat destruction. ? The principle of temheat destruction minimization was introduced. ? It is shown that the rate of total temheat destruction is minimized in steady heat conduction and fluid flow problems. - Abstract: Heat transfer and fluid flow processes exhibit similarities as they occur naturally and are governed by the same type of differential equations. Natural phenomena occur always in an optimum way. In this paper, the natural optimality that exists in the heat transfer and fluid flow processes is investigated. In this regard, heat transfer and fluid flow problems are treated as optimization problems. We discovered a thermodynamic quantity that is optimized during the steady heat transfer and fluid flow processes. Consequently, a new thermodynamic property, the so called temheat, is introduced using the second law of thermodynamics and the definition of entropy. It is shown, through several examples, that overall temheat destruction is always minimized in steady heat and fluid flow processes. The principle of temheat destruction minimization that is based on the temheat balance equation provides a better insight to understand how the natural flow processes take place.

2012-07-01

242

Process and apparatus for analyzing gas flows inside hollow bodies

International Nuclear Information System (INIS)

This invention concerns a real time technique for analyzing a gas flow moving through a hollow body such as a turbomachine, for obtaining three-dimensional information on the path taken by the gas when it passes through the motor. The difficulties to be overcome are constituted by the rate at which the gases move in the motor, the spreading of the gas flow in the body and the fact that the tracer employed in this analysis contaminates the exhaust gases, and possibly some of the motor, thereby leading to possible pollution hazards. This invention overcomes these troubles by using isotopes specially chosen for their short half life and the high radiation energy they generate, and by ensuring that the irradiation of the tracer substance occurs so as to produce an activity in the isotopes that is as great as possible and at the same time so as to enable the tracer to be injected in the motor as from the irradiation chamber for a very short period. The isotopes can be produced by bombardments of neutrons or by charged particles on to appropriate targets. A cyclotron is preferred as a source of charged particles

1980-01-01

243

Ring-Diagram Analysis: Status and Perspectives

Ring diagram analysis is now more than a decade old. While the details of the technique are still evolving, the application of the method to MDI, TON, Mt. Wilson, HLH, and GONG data is providing intriguing results. Thanks to the work of many people, it is now becoming possible to observationally infer the complicated dynamics in the outer 15 Mm of the solar convection zone, investigate the depth dependence of meridional flow, and get a closer look at zonal jet-stream structures in the mid-latitudes. We may soon be able to similarly investigate the spatio-temporal distribution of scalar fields. As ring diagrams and other local helioseismology methods such as time-distance and acoustic imaging continue to mature, the comparison of results from different techniques on common data sets will provide a useful reality check.

Hill, F.

244

Biodiesel and FAME synthesis assisted by microwaves: homogeneous batch and flow processes

Digital Repository Infrastructure Vision for European Research (DRIVER)

Fatty acids methyl esters (FAME) have been prepared under microwave irradiation, using homogeneous catalysis, either in batch or in a flow system. The quality of the biodiesel obtained has been confirmed by GC analysis of the isolated product. While the initial experiments have been performed in a small scale laboratory batch reactor, the best experiment has been straightforward converted into a stop-flow process, by the use of a microwave flow system. Compared with conventional heating metho...

Hernando, J.; Leto?n Garci?a, Pedro; Mati?a Marti?n, Ma La Paz; Novella Robisco, Jose? Luis; A?lvarez-builla Go?mez, Julio

2007-01-01

245

Model-based decentralised automatic management of product flow paths in processing plants

Digital Repository Infrastructure Vision for European Research (DRIVER)

This work introduces the model of product flow paths as a formal framework for the correct execution of product flow operations in processing plants. A product flow path is a software object responsible for controlling, monitoring and documenting the movement of products along a determined route in the plant, and represents a temporarily and spatially isolated area for the safe and correct transport of products. A formal model provides a guide for the implementation of decentralised object-or...

Quiro?s Araya, Gustavo Arturo

2010-01-01

246

Finite element modelling of plastic instability during ECAP processing of flow-softening materials

International Nuclear Information System (INIS)

A finite element analysis of the equal channel angular pressing (ECAP) of flow-softening materials is presented in this paper. A very fine mesh was used in the simulations, allowing a detailed analysis of the development of localized shear phenomena. Two different flow curves were used in the simulations; one displayed an initial flow-softening followed by perfect plastic behavior, whereas the other followed a constant flow-softening behavior. The flow-softening rate affects the intensity of shear localization. The deformation zone, that is usually concentrated around a fixed shear plane during processing of perfect plastic or strain hardening materials, splits into two parts and its position varies cyclically during the process, leading to oscillations in the punch load during processing. A comparison of the finite element predictions with those from the slip line field theory is also presented

2006-08-25

247

Potential-pH diagrams show the domains of redoxpotential and pH in which major species are most stable. Constructing such diagrams provides students with opportunities to decide what species must be considered, search literature for equilibrium constants and free energies of formation, and practice in using the Nernst equation. (Author/JN)

Barnum, Dennis W.

1982-01-01

248

Cohomology of diagrams of algebras

Digital Repository Infrastructure Vision for European Research (DRIVER)

We consider cohomology of diagrams of algebras by Beck's approach, using comonads. We then apply this theory to computing the cohomology of $\\Psi$-rings. Our main result is that there is a spectral sequence connecting the cohomology of the diagram of an algebra to the cohomology of the underlying algebra.

Robinson, Michael

2008-01-01

249

Flow visualisation methods such as dye tracers have long been a core methodology for the analysis of turbulent flows. These methods are ideally suited to qualitative observations of coherent structures and their past usage has yielded important insights into turbulent flows. However, the analysis of flow visualisation data need not be limited to qualitative observations. Digital image processing and basic form recognition methods largely developed in the context of remote sensing and earth observation can be applied to flow visualisation experiments in order to extract quantitative information. This paper will demonstrate how such methods can be used on digital films of dye tracer experiments. Specifically, we will examine naturally occurring flow structures observed during a dye tracer experiment conducted in a gravel bed river in Quebec, Canada. The image analysis will be applied in order to automatically identify individual coherent flow structures, measure their size, their orientation in the flow and finally their mean downstream velocity. This novel application of image processing methods to dye tracer experiments allows for quantitative flow visualisations which in turn yield a much more detailed description of coherent flow structures.

Carbonneau, P. E.; Marquis, G.; Roy, A. G.

2007-12-01

250

Digital Repository Infrastructure Vision for European Research (DRIVER)

Sediment transport models require appropriate representation of near-bed processes. We aim here to explore the parameterizations of bed shear stress, bed load transport rate and near-bed sediment erosion rate under the sheet flow regime. To that end, we employ a one-dimensional two-phase sheet flow model which is able to resolve the intrawave boundary layer and sediment dynamics at a length scale on the order of the sediment grain. We have conducted 79 numerical simulations to cover a range o...

2010-01-01

251

Aeolian process-induced hyper-concentrated flow in a desert watershed

Aeolian sand supply and the development of the hyper-concentrated flow.Ratio of sandstorm frequency to rainstorm frequency regulating occurrence of the hyper-concentrated flow.Aeolian processes can accelerate sediment losses from aeolian–fluvial interplayed watersheds rather than inhibit them.

Ta, Wanquan; Wang, Haibin; Jia, Xiaopeng

2014-04-01

252

Comparison of Inflation Processes at the 1859 Mauna Loa Flow, HI, and the McCartys Flow Field, NM

Basaltic lavas typically form channels or tubes during flow emplacement. However, the importance of sheet flow in the development of basalt ic terrains received recognition over the last 15 years. George Walke r?s research on the 1859 Mauna Loa Flow was published posthumously in 2009. In this paper he discusses the concept of endogenous growth, or inflation, for the distal portion of this otherwise channeldominated lava flow. We used this work as a guide when visiting the 1859 flow to help us better interpret the inflation history of the McCartys flow field in NM. Both well preserved flows display similar clues about the process of inflation. The McCartys lava flow field is among the you ngest (approx.3000 yrs) basaltic lava flows in the continental United States. It was emplaced over slopes of <1 degree, which is similar to the location within the 1859 flow where inflation occurred. Although older than the 1859 flow, the McCartys is located in an arid environ ment and is among the most pristine examples of sheet flow morphologies. At the meter scale the flow surface typically forms smooth, undula ting swales that create a polygonal terrain. The literature for simil ar features includes multiple explanatory hypotheses, original breakouts from adjacent lobes, or inflation related upwarping of crust or sa gging along fractures that enable gas release. It is not clear which of these processes is responsible for polygonal terrains, and it is po ssible that one explanation is not the sole cause of this morphology between all inflated flows. Often, these smooth surfaces within an inflated sheet display lineated surfaces and occasional squeeze-ups alon g swale contacts. We interpret the lineations to preserve original fl ow direction and have begun mapping these orientations to better interpret the emplacement history. At the scale of 10s to 100s of meters t he flow comprises multiple topographic plateaus and depressions. Some depressions display level floors with surfaces as described above, while some are bowl shaped with floors covered in broken lava slabs. Th e boundaries between plateaus and depressions are also typically smoo th, grooved surfaces that have been tilted to angles sometimes approaching vertical. The upper margin of these tilted surfaces displays lar ge cracks, sometimes containing squeeze-ups. The bottom boundary with smooth floored depressions typically shows embayment by younger lavas. It appears that this style of terrain represents the emplacement of an extensive sheet that experiences inflation episodes within prefer red regions where lateral spreading of the sheet is inhibited, thereby forming plateaus. Depressions are often the result of non-inflation and can be clearly identified by lateral squeeze-outs along the pit walls that form when the rising crust exposes the still liquid core of the sheet. Our current efforts are focused on.

Bleacher, Jacob E.; Garry, W. Brent; Zimbelman, James R.; Crumpler, Larry S.

2012-01-01

253

Effect of deformation diagram on molybdenum structure and properties

International Nuclear Information System (INIS)

Effect of deformation diagram on a tendency to lamination and mechanical properties of disks made of molybdenum alloy is studied. Investigated samples were subjected to hot rolling or forging. X-ray structural analysis of texture is carried out along with estimation of the level of mechanical properties across item cross section. Sample mechanical bending tests were conducted. Sample microstructure is also studied. It is shown that rolled molybdenum has a tendency to lamination, but forged molybdenum is free of such a tendency. Forged sample ductility is practically equal in all directionse but rolled sample ductility in a surface layer is high and decreases with depth. A conclusion is drawn that forged sample grains in a setting surface are equiaxial, but distinct deformation texture is observed for rolled samples and their grains are elongated in the direction of rolling. A conclusion is made that a flow diagram of the process of disk fabrication by forging or stamping ppovides a necessary complex of physicomechanical properties of metal as compared to polling, and metal discharge coefficient decreases sharply in this case

1984-01-01

254

Generalized Fleming-Viot processes with immigration via stochastic flows of partitions

The generalized Fleming-Viot processes were defined in 1999 by Donnelly and Kurtz using a particle model and by Bertoin and Le Gall in 2003 using stochastic flows of bridges. In both methods, the key argument used to characterize these processes is the duality between these processes and exchangeable coalescents. A larger class of coalescent processes, called distinguished coalescents, was set up recently to incorporate an immigration phenomenon in the underlying population. The purpose of this article is to define and characterize a class of probability-measure valued processes called the generalized Fleming-Viot processes with immigration. We consider some stochastic flows of partitions of Z_{+}, in the same spirit as Bertoin and Le Gall's flows, replacing roughly speaking, composition of bridges by coagulation of partitions. Identifying at any time a population with the integers $\\mathbb{N}:=\\{1,2,...\\}$, the formalism of partitions is effective in the past as well as in the future especially when there ar...

Foucart, Clément

2011-01-01

255

Effects of elliptic flow and resonance decay process on the Kurtosis of net baryon distributions

International Nuclear Information System (INIS)

Kurtosis is regarded as a meaningful and promising observable in searching for the possible critical point predicted by QCD. In this paper, the effects of elliptic flow and resonance decay process on the Kurtosis have been studied with Monte Carlo event generators in Au + Au collisions at ? sNN = 200 GeV. The results show that the Kurtosis is not sensitive to elliptic flow and resonance decay process.(authors)

2011-05-01

256

The classification of diagrams in perturbation theory

International Nuclear Information System (INIS)

The derivation of scattering equations connecting the amplitudes obtained from diagrammatic expansions is of interest in many branches of physics. One method for deriving such equations is the classification-of-diagrams technique of Taylor. However, as we shall explain in this paper, there are certain points of Taylor's method which require clarification. First, it is not clear whether Taylor's original method is equivlant to the simpler classification-of-diagrams scheme used by Thomas, Rinat, Afnan, and Blankleider (TRAB). Second, when the Taylor method is applied to certain problems in a time-dependent perturbation theory it leads to the over-counting of some diagrams. This paper first restates Taylor's method, in the process uncovering reasons why certain diagrams might be double-counted in the Taylor method. In then explores how far Taylor's method is equivalent to the simpler TRAB method. Finally, it examines precisely why the double-counting occurs in Taylor's method and derives corrections which compensate for this double-counting. copyright 1995 Academic Press, Inc

1995-06-01

257

Energy Technology Data Exchange (ETDEWEB)

In this report, the thrust areas include the following: Internal drives, vapor-liquid flows, combustion and reaction processes, fluid displacements and the effect of instabilities and heterogeneities and the flow of fluids with yield stress. These find respective applications in foamy oils, the evolution of dissolved gas, internal steam drives, the mechanics of concurrent and countercurrent vapor-liquid flows, associated with thermal methods and steam injection, such as SAGD, the in-situ combustion, the upscaling of displacements in heterogeneous media and the flow of foams, Bingham plastics and heavy oils in porous media and the development of wormholes during cold production.

Yortsos, Yanis C.

2002-10-08

258

Directory of Open Access Journals (Sweden)

Full Text Available Este artigo apresenta um método para a medição de inventário em processo e tempo de atravessamento em um sistema de manufatura. O método consiste em modelar a manufatura por redes de Petri, simular o modelo em computador, alimentando-o com a situação de carga inicial dos processos e com um plano de produção, obtendo os momentos simulados de conclusão de cada ordem do plano. Após este procedimento, com o uso do diagrama de resultados e da fórmula do funil, calcula-se o valor médio simulado de inventário em processo que o plano produzirá na manufatura. Ao fim, faz-se uma discussão na qual explora-se como os resultados do método podem ser úteis em decisões de gestão, envolvendo o inventário admitido, pulmões e restrições da manufatura.This paper presents a method to measure work-in-process and leadtime in a manufacturing system. The method consists of modeling manufacturing by Petri nets, providing as input for the model the initial load of the process and a production plan, running it and obtaining from the simulation the moments of completion of the orders. Using the throughput diagram and the funnel formula, we then calculate the mean simulated value of the work-in-process that the plan will produce in the manufacturing system. Finally, we discuss how the results can be used to underpin management decisions on issues such as actual work-in-process, buffers and manufacturing constraints.

Tiago Facchin

2008-08-01

259

Comparison of Inflation Processes at the 1859 Mauna Loa Flow, HI, and the McCartys Flow Field, NM

Basaltic lavas typically form channels or tubes during flow emplacement. However, the importance of sheet flow in the development of basalt ic terrains received recognition over the last 15 years. George Walke r?s research on the 1859 Mauna Loa Flow was published posthumously in 2009. In this paper he discusses the concept of endogenous growth, or inflation, for the distal portion of this otherwise channeldominated lava flow. We used this work as a guide when visiting the 1859 flow to help us better interpret the inflation history of the McCartys flow field in NM. Both well preserved flows display similar clues about the process of inflation. The McCartys lava flow field is among the you ngest (approx.3000 yrs) basaltic lava flows in the continental United States. It was emplaced over slopes of inflation occurred. Although older than the 1859 flow, the McCartys is located in an arid environ ment and is among the most pristine examples of sheet flow morphologies. At the meter scale the flow surface typically forms smooth, undula ting swales that create a polygonal terrain. The literature for simil ar features includes multiple explanatory hypotheses, original breakouts from adjacent lobes, or inflation related upwarping of crust or sa gging along fractures that enable gas release. It is not clear which of these processes is responsible for polygonal terrains, and it is po ssible that one explanation is not the sole cause of this morphology between all inflated flows. Often, these smooth surfaces within an inflated sheet display lineated surfaces and occasional squeeze-ups alon g swale contacts. We interpret the lineations to preserve original fl ow direction and have begun mapping these orientations to better interpret the emplacement history. At the scale of 10s to 100s of meters t he flow comprises multiple topographic plateaus and depressions. Some depressions display level floors with surfaces as described above, while some are bowl shaped with floors covered in broken lava slabs. Th e boundaries between plateaus and depressions are also typically smoo th, grooved surfaces that have been tilted to angles sometimes approaching vertical. The upper margin of these tilted surfaces displays lar ge cracks, sometimes containing squeeze-ups. The bottom boundary with smooth floored depressions typically shows embayment by younger lavas. It appears that this style of terrain represents the emplacement of an extensive sheet that experiences inflation episodes within prefer red regions where lateral spreading of the sheet is inhibited, thereby forming plateaus. Depressions are often the result of non-inflation and can be clearly identified by lateral squeeze-outs along the pit walls that form when the rising crust exposes the still liquid core of the sheet. Our current efforts are focused on.

Bleacher, Jacob E.; Garry, W. Brent; Zimbelman, James R.; Crumpler, Larry S.

2012-01-01

260

Multilayer roll bonded aluminium foil: processing, microstructure and flow stress

International Nuclear Information System (INIS)

Bulk aluminium has been produced by warm-rolling followed by cold-rolling of commercial purity (99% purity) aluminium foil. The bonding appeared perfect from observation with the naked eye, light and transmission electron microscopy. By comparison with bulk aluminium of similar purity (AA1200) rolled to a similar strain (90%RA), the roll-bonded metal showed a much higher density of high-angle grain boundaries, similar strength and improved thermal stability. This study has implications for a number of applications in relation to the processing of aluminium. Roll bonding is of interest as a method for grain size refinement; oxide-containing materials have increased strength, enhanced work-hardening behaviour, and exhibit alterations in recrystallisation behaviour. The behaviour of the hard oxide film is of interest in aluminium processing, and has been investigated by characterising the size and distribution of oxide particles in the roll-bonded samples

2004-08-02

261

The Hopf algebra approach to Feynman diagram calculations

Energy Technology Data Exchange (ETDEWEB)

The Hopf algebra structure underlying Feynman diagrams which governs the process of renormalization in perturbative quantum field theory is reviewed. Recent progress is briefly summarized with an emphasis on further directions of research. (topical review)

Ebrahimi-Fard, Kurusch [Universitaet Bonn, Physikalisches Institut, Nussallee 12, D-53115 Bonn (Germany); Kreimer, Dirk [CNRS-IHES, Le Bois-Marie, 35, Route de Chartres, F-91440 Bures-sur-Yvette (France); Center for Math. Phys., Boston University, MA (United States)

2005-12-16

262

Numerical simulations of directional solidification of Si melt are performed to study the heat transfer characteristics like stream line flow, Peclet cell number and cell Reynolds number. Dimensionless numbers are of key importance in parametric analysis of non-linear complex transport phenomena of bulk silicon growth process. They are also extremely useful in understanding of the heat and mass transfer of fluid flow on Si melt during crystal growth processes. The flow and thermal pattern influences the quality of the crystal through the convective heat and mass transport. The art of dimensionless numbers like Peclet cell numbers, Reynolds cell numbers on the flow field were studied with the help of numerical simulation. The computations are carried out in a 2D axisymmetric model using the finite-element technique. The results indicate that thermal forces have a dramatic effect on the flow of silicon melt. The simulation results are in reasonable agreement with the predictions of the theoretical approach.

Srinivasan, M.; Ramasamy, P.

2014-04-01

263

On the application of kinematic models to simulate the diffusive processes of debris flows

Directory of Open Access Journals (Sweden)

Full Text Available Debris flows generally propagate along steep mountain torrents with dynamics primarily governed by gravitational and frictional forces. Thus, debris flows modelling can be successfully performed through the application of kinematic models, which consider only the effects of slope and friction and neglect the remaining terms of the momentum equation. However, the diffusion processes that can be observed in the field, such as the spreading of the debris flow wave as it flows downstream, can not be theoretically predicted by kinematic models, since diffusion is a second-order process neglected in the kinematic approximation. In this paper, this issue is discussed and an application for both a generalized diffusion wave model and a kinematic model is proposed of a debris flow which occurred in an Italian instrumented torrent to identify, in a real case scenario, the effective value of the neglected terms in the kinematic approximation.

M. Arattano

2010-08-01

264

[Study of regional blood flow in the prognosis of the process of healing of postoperative wounds].

The authors suggest using the regional blood flow in control over the course of the wound process after various types of laparotomy so as to prognosticate the possibility of suppuration of the postoperative wounds. Examination of 20 patients showed that the regional blood flow values depended on the operative trauma and the character of the inflammatory process in the abdominal cavity. Decrease of the regional blood flow in the wound to 24 ml/min/100 g and lower indicates that purulent inflammation will most probably develop in the postoperative wound. PMID:2528656

Kuleshov, E V; Diachuk, I A; Liapis, M A; Benedikt, V V; Gumeniuk, V V

1989-06-01

265

Recent results in Ring Diagram analysis

The ring-diagram technique was developed by Frank Hill 25 years ago and developed quickly during the late 1990s. It is nowadays one of the most commonly used techniques in local helioseismology. The method consists in the power spectral analysis of solar acoustic oscillations on small regions (2 to 30 degrees) of the solar surface. The power spectrum resembles a set of trumpets nested inside each other and, for a given frequency, it looks like a ring, hence the technique's name. It provides information on the horizontal flow field and thermodynamic structure in the layers immediately below the photosphere. With data regularly provided by MDI (on board SOHO), GONG+ network and more recently HMI (on SDO), many important results have been achieved. In recently years, these results include estimations of the meridional circulation and its evolution with solar cycle; flows associated with active regions, as well as, flow divergence and vorticity; and thermal structure beneath and around active regions. Much progre...

Rabello-Soares, M Cristina

2013-01-01

266

Concrete and abstract Voronoi diagrams

Energy Technology Data Exchange (ETDEWEB)

The Voronoi diagram of a set of sites is a partition of the plane into regions, one to each site, such that the region of each site contains all points of the plane that are closer to this site than to the other ones. Such partitions are of great importance to computer science and many other fields. The challenge is to compute Voronoi diagrams quickly. The problem is that their structure depends on the notion of distance and the sort of site. In this book the author proposes a unifying approach by introducing abstract Voronoi diagrams. These are based on the concept of bisecting curves which are required to have some simple properties that are actually possessed by most bisectors of concrete Voronoi diagrams. Abstract Voronoi diagrams can be computed efficiently and there exists a worst-case efficient algorithm of divide-and-conquer type that applies to all abstract Voronoi diagrams satisfying a certain constraint. The author shows that this constraint is fulfilled by the concrete diagrams based no large classes of metrics in the plane.

Klein, R. (Universitat-Gesamthochschule Essen (DE))

1989-01-01

267

With the development of remote sensing satellites, the data quantity of remote sensing image is increasing tremendously, which brings a huge workload to the image geometric rectification through manual ground control point (GCP) selections. GCP database is one of the effective methods to cut down manual operation. The GCP loaded from database is generally redundant, which may result in a rectification slowdown. How to automatically optimize these ground control points is a problem that should be resolved urgently. According to the basic theory of geometric rectification and the principle of GCP selection, this paper deeply comprehends some existing methods about automatic optimization of GCP, and puts forward a new method of automatic optimization of GCP based on voronoi diagram to filter ground control points from the overfull ones without manual subjectivity for better accuracy. The paper is organized as follows: First, it clarifies the basic theory of remote sensing image multinomial geometric rectification and the arithmetic of how to get the GCP error. Second, it particularly introduces the voronoi diagram including its origin, development and characteristics, especially the creating process. Third, considering the deficiencies of existing methods about automatic optimization of GCP, the paper presents the idea of applying voronoi diagram to filter GCP in order to complete automatic optimization. During this process, it advances the conception of single GCP's importance value based on voronoi diagram. Then by integrating the GCP error and GCP's importance value, the paper gives the theory and the flow of automatic optimization of GCPs as well. It also presents an example of the application of this method. In the conclusion, it points out the advantages of automatic optimization of GCP based on the voronoi diagram.

Li, Ying; Cheng, Bo

2009-10-01

268

Automating First-Principles Phase Diagram Calculations

Devising a computational tool that assesses the thermodynamic stability of materials is among the most important steps required to build a ``virtual laboratory'', where materials could be designed from first-principles without relying on experimental input. Although the formalism that allows the calculation of solid state phase diagrams from first principles is well established, its practical implementation remains a tedious process. The development of a fully automated algorithm to perform such calculations serves two purposes. First, it will make this powerful tool available to large number of researchers. Second, it frees the calculation process from arbitrary parameters, guaranteeing that the results obtained are truly derived from the underlying first-principles calculations. The proposed algorithm formalizes the most difficult step of phase diagram calculations, namely the determination of the ``cluster expansion'', which is a compact representation of the configurational dependence of the alloy's energ...

De van Walle, A

2002-01-01

269

Do students use and understand free-body diagrams?

Directory of Open Access Journals (Sweden)

Full Text Available Physics education literature recommends using multiple representations to help students understand concepts and solve problems. However, there is little research concerning why students use the representations and whether those who use them are more successful. This study addresses these questions using free-body diagrams (diagrammatic representations used in problems involving forces as a type of representation. We conducted a two-year quantitative and qualitative study of students’ use of free-body diagrams while solving physics problems. We found that when students are in a course that consistently emphasizes the use of free-body diagrams, the majority of them do use diagrams on their own to help solve exam problems even when they receive no credit for drawing the diagrams. We also found that students who draw diagrams correctly are significantly more successful in obtaining the right answer for the problem. Lastly, we interviewed students to uncover their reasons for using free-body diagrams. We found that high achieving students used the diagrams to help solve the problems and as a tool to evaluate their work while low achieving students only used representations as aids in the problem-solving process.

David Rosengrant

2009-06-01

270

Digital Repository Infrastructure Vision for European Research (DRIVER)

We encode the genealogy of a continuous-state branching process associated with a branching mechanism $\\Psi$ - or $\\Psi$-CSBP in short - using a stochastic flow of partitions. This encoding holds for all branching mechanisms and appears as a very tractable object to deal with asymptotic behaviours and convergences. In particular we study the so-called Eve property - the existence of an ancestor from which the entire population descends asymptotically - and give a necessary a...

Labbe?, Cyril

2012-01-01

271

Case study: Class diagram restructuring

Directory of Open Access Journals (Sweden)

Full Text Available This case study is an update-in-place refactoring transformation on UML class diagrams. Its aim is to remove clones of attributes from a class diagram, and to identify new classes which abstract groups of classes that share common data features. It is used as one of a general collection of transformations (such as the removal of redundant inheritance, or multiple inheritance which aim to improve the quality of a specification or design level class diagram. The transformation is a typical example of a model refactoring, and illustrates the issues involved in such transformations.

K. Lano

2013-11-01

272

Improving Energy Efficiency of Process of Direct Adipic Acid Synthesis in Flow Using Pinch Analysis

Digital Repository Infrastructure Vision for European Research (DRIVER)

Together with transport and chemical intensification, process design intensification is situated under the umbrella of Novel Process Windows and heads for integrated and simplified smart scaled (micro/meso) flow process design in a holistic picture. As a demonstration example, the direct oxidation of cyclohexene with hydrogen peroxide for adipic acid synthesis is considered It provides an innovative alternative to the two-step industrial process currently used It is aimed to design an energy ...

Vural-gursel, I.; Wang, Q.; Noe?l, T.; Hessel, V.; Tinge, Jt

2013-01-01

273

Particles, Feynman Diagrams and All That

Quantum fields are introduced in order to give students an accurate qualitative understanding of the origin of Feynman diagrams as representations of particle interactions. Elementary diagrams are combined to produce diagrams representing the main features of the Standard Model.

Daniel, Michael

2006-01-01

274

Sn60Pb40 solder powders produced by the planar flow casting atomization process

Directory of Open Access Journals (Sweden)

Full Text Available Conventional planar flow casting (PFC is one of rapid solidification processes for the fabrication of microcrystalline or amorphous ribbons. Based on the conventional PFC process, the planar flow casting atomization (PFCA process has been developed, which is a new rapid solidification process for the production of metal powder directly from alloy melts. A prototype experimental apparatus was designed and manufactured. With the apparatus, Sn60Pb40 alloy solder powders were prepared, and the effects of the main technological parameters on the powder size distribution and morphology were experimentally studied. The experimental investigations indicate that the metal powders produced by the PFCA process can be classified by velocity; and fine spherical tin-lead alloy solder powders can be fabricated by adjusting the technical parameters. The new PFCA process has such features as high productivity and efficiency, low energy consumption, simple operation, short technological process, and large gross yield.

Xiang Qingchun

2011-05-01

275

Atemporal diagrams for quantum circuits

A system of diagrams is introduced that allows the representation of various elements of a quantum circuit, including measurements, in a form which makes no reference to time (hence ``atemporal''). It can be used to relate quantum dynamical properties to those of entangled states (map-state duality), and suggests useful analogies, such as the inverse of an entangled ket. Diagrams clarify the role of channel kets, transition operators, dynamical operators (matrices), and Kraus rank for noisy quantum channels. Positive (semidefinite) operators are represented by diagrams with a symmetry that aids in understanding their connection with completely positive maps. The diagrams are used to analyze standard teleportation and dense coding, and for a careful study of unambiguous (conclusive) teleportation. A simple diagrammatic argument shows that a Kraus rank of 3 is impossible for a one-qubit channel modeled using a one-qubit environment in a mixed state.

Griffiths, R B; Yu, L; Cohen, S M; Griffiths, Robert B.; Wu, Shengjun; Yu, Li; Cohen, Scott M.

2005-01-01

276

Diagrams and Proofs in Analysis

DEFF Research Database (Denmark)

The article discusses the role of diagrams in mathematical reasoning based on a case study in analysis. Â In the presented example certain combinatorial expressions were first found by using diagrams. In the published proofs the pictures are replaced by reasoning about permutation groups. This paper argues that, even though the diagrams are not present in the papers, they still play a role in the formulation of the proofs. It is shown that they play a role in concept formation as well as representations of proofs. In addition we note that `visualizaton' is used in different ways. In the first sense visualization denotes our inner mental pictures, which enables us to see that a certain fact holds, whereas in the other sense, `visualization' denotes a diagram or representation of something.

Carter, Jessica M H Grund

2010-01-01

277

Gaussian Process Regression Approach for modeling subsurface flow

Inverse modeling involves repeated evaluations of the forward simulation, which can be computationally prohibitive for large numerical models. To reduce the overall computational burden of these simulations, we study the use of Gaussian process (GP) regression models as numerical surrogates. Similar to most reduced order models (ROMs), GP regression models involve using solutions at different sample points within the parameter space to construct an approximate solution at any point within the parameter space. However, since GP regression models are derived from a statistical Bayesian framework, they provide valuable statistical insights that can be incorporated into parameter estimation and uncertainty quantification algorithms. More importantly, we show that the resulting ROMs perform better than look-up tables, particularly when the number of sample points is small. We also show how these sample points can be optimally chosen to minimize computational efforts without user intervention. The GP regression models are currently implemented as part of a family of ROMs within the inverse modeling framework of iTOUGH2. We will demonstrate how GP regression models can be used within the iTOUGH2 framework to improve performance of uncertainty quantification.

Pau, G.; Zhang, Y.; Finsterle, S.

2012-12-01

278

Phase diagrams of the elements

International Nuclear Information System (INIS)

A summary of the pressure-temperature phase diagrams of the elements is presented, with graphs of the experimentally determined solid-solid phase boundaries and melting curves. Comments, including theoretical discussion, are provided for each diagram. The crystal structure of each solid phase is identified and discussed. This work is aimed at encouraging further experimental and theoretical research on phase transitions in the elements

1975-01-01

279

Introduction to Ternary Phase Diagrams

This exercise is intended as a group exercise to help students learn the fundamentals of using ternary phase diagrams. It is a much better way for students to learn about the diagrams than to lecture to them. Good students will be able to walk through this with little assistance from the instructor.Weaker students will struggle and need help from peers or instructors. The entire exercise takes 1-2 hours for most.

Perkins, Dexter

280

FPGA Implementations of Ladder Diagrams

Digital Repository Infrastructure Vision for European Research (DRIVER)

The performance of programmable logic controllers is often constrained by the microprocessor and the real-time firmware of the controller. Field programmable gate arrays (FPGAs) are an attractive potential implementation medium for high-speed control because of their fast and parallel execution and programmable nature. Ladder Diagrams are a standard graphical programming method for industrial controllers, but compilers from Ladder Diagrams to FPGA hardware do not yet exist. This pape...

2013-01-01

281

Structure and Microhardness of Steel Samples after Pulse Plasma Flows Processing

Digital Repository Infrastructure Vision for European Research (DRIVER)

The phase structure of surfaces of steel samples, modified by pulse plasma processing, was analyzed using XRD and metallographic methods. It has been shown, that after pulse plasma processing under different conditions a modified structure consisting of three new phases, including austenite, iron nitride and carbide, is formed. The dependence of phase transition and microhardness on plasma flow parameters has been studied....

2013-01-01

282

Debris flows in mountain streams and ravines cause severe natural hazards due to their high velocity, large volumes, and immense destructive power. In catchments with high sediment supplies and steep channels, debris flows are generally caused by channel mobilization. In these catchments, there is a possibility that changes in quality and quantity of channel deposits influence the initiation of debris flows, because channel deposits constitute the main material of the flow as well as determine the hydrological initiation conditions. However, temporal changes in quality and quantity of deposits in steep channels have not been evaluated because of difficulties related to field observations. Here we examine changes of channel deposits in the initiation zone based on field observations in upper Ichinosawa catchment of the Ohya landslide in Japan. In spring 1998, a monitoring system was installed consisting of video cameras, ultrasonic sensors, capacitive water depth probes and water pressure sensors to discriminate the occurrence of debris flows and assess the rainfall-runoff processes of the catchment. Channel deposits of upper Ichinosawa catchment were periodically photographed to estimate their volume and diameter. Such measurements indicate that sediment supply by freeze-thaw increases the volume of channel deposits and decreases the diameter of bed surface material, whereas occurrence of debris flows decrease the volume of channel deposits and increase the diameter of bed surface material. Influence of other sediment supply processes (landslide and surface erosion) and bedload and suspended sediment transport on changes in volume and diameter of channel deposits is small compared with freeze-thaw and debris flow processes. Physical analyses indicate that sediment supplies and transport processes are largely influenced by gradients of hillslopes and channels. Field observations show that volume and diameter variations in channel deposits cause changes in rainfall-runoff processes. These seasonal changes in channel deposits may be important for estimating volume and timing of debris flows.

Imaizumi, F.; Sidle, R. C.; Tsuchiya, S.; Ohsaka, O.

2004-12-01

283

A self-sustaining nonlinear dynamo process in Keplerian shear flows

A three-dimensional nonlinear dynamo process is identified in rotating plane Couette flow in the Keplerian regime. It is analogous to the hydrodynamic self-sustaining process in non-rotating shear flows and relies on the magneto-rotational instability of a toroidal magnetic field. Steady nonlinear solutions are computed numerically for a wide range of magnetic Reynolds numbers but are restricted to low Reynolds numbers. This process may be important to explain the sustenance of coherent fields and turbulent motions in Keplerian accretion disks, where all its basic ingredients are present.

Rincon, F; Proctor, M R E

2007-01-01

284

Analysis of different water-sediment flow processes in a mountain torrent

Directory of Open Access Journals (Sweden)

Full Text Available Sediment – water flows occurring in mountain torrents may show a variety of regimes, ranging from water flows with transport of individual particles to massive transport of debris, as it occurs in case of debris flows. Sometimes it is possible, by means of accurate field investigations, to identify the kind of processes that took place in a torrent after the occurrence of an event. However this procedure cannot give indications regarding the development of the process in time. In fact, because of the frequent presence of different surges within the same event, the rheological characteristics of an event can be detected only when some recorded hydrographs or videos are available. For the same reason, since the rheological behaviour of the flow changes according to the solid concentration, the analysis of the materials deposited on the debris fan cannot directly give any information on the particular types of flow that took place: a possible alternation in time of different water sediment surges with different concentrations may have occurred, during the same event. The installation of ultrasonic gauges or videocameras along the torrent might give more information on this issue. To this regard, the analysis of a flow event which occurred in 2002 in the Moscardo torrent watershed, instrumented for debris flow monitoring, has been undertaken, studying the hydrographs recorded at two different ultrasonic gauges placed at a known distance along the torrent. An empirical flow resistance law has been applied analysing the values assumed by its parameters after calibration. The application of this law actually spans from debris flow and immature debris flow to bed load transport. Only field observations and surveys, together with ultrasonic data, may allow to clearly discriminate which type of flow really occurred. The analysis confirms that different water sediment surges alternated in time while the mathematical simulation of the flow compared with field observations revealed that the dynamic behaviour of the flow was different from that of previous debris flow events and might reflect, among the different types of possible rheological behaviors, a dilatant-type behavior typical of stony debris flows.

M. Arattano

2004-01-01

285

Post-Processing of Discrete Flow Field Data for Particle Tracking Velocimetry

Directory of Open Access Journals (Sweden)

Full Text Available To measure the surface flow in a physical river model, a brief introduction was given to the method of Particle Tracking Velocimetry (PTV. According to the characteristics of PTV by seeding particles on the water surface, particle images can be captured by CCD cameras and recognized by image division. PTV algorithm gives one vector for each particle based on the principle the trajectory of an individual particle is continuous. The key problem of analyzing the flow speed field accurately is post-processing of discrete flow field data. Errors of measurement discrete data are removed by the basic law of water movement. To attain the whole flow speed field, the methods of interpolation of discrete flow field data were proposed. In addition, the graphics of streamlines, velocity isolines and vortex isolines were drawn by the theory of hydraulic calculation.

Wang Pengtao

2013-01-01

286

On the self-organizing process of large scale shear flows

International Nuclear Information System (INIS)

Self organization is invoked as a paradigm to explore the processes governing the evolution of shear flows. By examining the probability density function (PDF) of the local flow gradient (shear), we show that shear flows reach a quasi-equilibrium state as its growth of shear is balanced by shear relaxation. Specifically, the PDFs of the local shear are calculated numerically and analytically in reduced 1D and 0D models, where the PDFs are shown to converge to a bimodal distribution in the case of finite correlated temporal forcing. This bimodal PDF is then shown to be reproduced in nonlinear simulation of 2D hydrodynamic turbulence. Furthermore, the bimodal PDF is demonstrated to result from a self-organizing shear flow with linear profile. Similar bimodal structure and linear profile of the shear flow are observed in gulf stream, suggesting self-organization

2013-09-01

287

On the self-organizing process of large scale shear flows

Energy Technology Data Exchange (ETDEWEB)

Self organization is invoked as a paradigm to explore the processes governing the evolution of shear flows. By examining the probability density function (PDF) of the local flow gradient (shear), we show that shear flows reach a quasi-equilibrium state as its growth of shear is balanced by shear relaxation. Specifically, the PDFs of the local shear are calculated numerically and analytically in reduced 1D and 0D models, where the PDFs are shown to converge to a bimodal distribution in the case of finite correlated temporal forcing. This bimodal PDF is then shown to be reproduced in nonlinear simulation of 2D hydrodynamic turbulence. Furthermore, the bimodal PDF is demonstrated to result from a self-organizing shear flow with linear profile. Similar bimodal structure and linear profile of the shear flow are observed in gulf stream, suggesting self-organization.

Newton, Andrew P. L. [Department of Applied Maths, University of Sheffield, Sheffield, Yorkshire S3 7RH (United Kingdom); Kim, Eun-jin [School of Mathematics and Statistics, University of Sheffield, Sheffield, Yorkshire S3 7RH (United Kingdom); Liu, Han-Li [High Altitude Observatory, National Centre for Atmospheric Research, P. O. BOX 3000, Boulder, Colorado 80303-3000 (United States)

2013-09-15

288

Energy Technology Data Exchange (ETDEWEB)

This report is an investigation of various multi-phase and multiscale transport and reaction processes associated with heavy oil recovery. The thrust areas of the project include the following: Internal drives, vapor-liquid flows, combustion and reaction processes, fluid displacements and the effect of instabilities and heterogeneities and the flow of fluids with yield stress. These find respective applications in foamy oils, the evolution of dissolved gas, internal steam drives, the mechanics of concurrent and countercurrent vapor-liquid flows, associated with thermal methods and steam injection, such as SAGD, the in-situ combustion, the upscaling of displacements in heterogeneous media and the flow of foams, Bingham plastics and heavy oils in porous media and the development of wormholes during cold production.

Yortsos, Y.C.

2001-05-29

289

Energy Technology Data Exchange (ETDEWEB)

This project is an investigation of various multi-phase and multiscale transport and reaction processes associated with heavy oil recovery. The thrust areas of the project include the following: Internal drives, vapor-liquid flows, combustion and reaction processes, fluid displacements and the effect of instabilities and heterogeneities and the flow of fluids with yield stress. These find respective applications in foamy oils, the evolution of dissolved gas, internal steam drives, the mechanics of concurrent and countercurrent vapor-liquid flows, associated with thermal methods and steam injection, such as SAGD, the in-situ combustion, the upscaling of displacements in heterogeneous media and the flow of foams, Bingham plastics and heavy oils in porous media and the development of wormholes during cold production.

Yortsos, Yanis C.

2001-08-07

290

Non-Linear Flow Process (NLFP): a new package implementing the Forchheimer equation in MODFLOW

Groundwater flow in porous media is usually considered to be laminar and to follow Darcy's law (i.e. a linear relationship between the specific discharge and the hydraulic gradient). However, flow can become non-linear or turbulent if a critical Reynolds number is exceeded. This is known to occur, for example, within the solution conduits of karst aquifers or in the vicinity of pumping wells. As most of the existing distributive groundwater models such as MODFLOW-2005 are based on Darcy's law, there is a lack of tools accounting for the non-linear or turbulent flow conditions encountered in these settings. For this reason, a new MODFLOW package (Non-Linear Flow Process; NLFP) simulating non-linear flow following the Forchheimer equation was developed and implemented in MODLFOW-2005. This package is essentially based on an iterative modification of the linear conductance used by MODFLOW. The resulting effective Forchheimer conductance decreases with increasing specific discharge and thus mimics the effect of the non-linear term of the Forchheimer equation. The method was implemented such that the different layer types, boundaries conditions, and solvers as well as the wetting capability of MODFLOW are supported. The NLFP package was also successfully integrated in the current version of the conduit flow process CFP (Shoemaker et al., U.S. Geological Survey Techniques and Methods 6-A24, 2008). The correct implementation of the package is demonstrated using three different benchmark scenarios for which analytical solutions are available. Finally, a scenario considering transient flow in a more realistic karst setting and a larger model grid demonstrates that NLFP performs well under more complex conditions, although it converges moderately slower than the standard MODFLOW depending on the non-linearity of flow. Thus, this new tool opens a field of opportunities to non-linear groundwater flow simulation with MODFLOW-2005, especially for core sample simulation or vuggy karstified aquifers as well as for non-linear flow in vicinity of pumping wells.

Mayaud, Cyril; Walker, Patrica; Hergarten, Stefan; Birk, Steffen

2014-05-01

291

Analysis of nuclear material flow for experimental DUPIC fuel fabrication process at DFDF

International Nuclear Information System (INIS)

This report describes facilities necessary for manufacturing experiment for DUPIC fuel, manufacturing process and equipment. Nuclear material flows among facilities, in PIEF and IMEF, for irradiation test, for post examination of DUPIC fuel, for quality control, for chemical analysis and for treatment of radioactive waste have been analyzed in details. This may be helpful for DUPIC project participants and facility engineers working in related facilities to understand overall flow for nuclear material and radioactive waste. (Author). 14 refs., 15 tabs., 41 figs

1999-01-01

292

New Gas Flow System for Long-Tape Reaction Tube of TFA-MOD Process

International Nuclear Information System (INIS)

A multi-turning Reel-to-Reel tape conveyance system of the long YBCO coated conductors using TFA-MOD process is desired to be high production rate without large degradation between tape lines. The numerical simulation, which calculated the YBCO growth kinetics, gas element diffusion and gas flow, shown a possibility that the vertical gas flow onto the tape surface realized high production rate of YBCO conductor even on the wider tape. This possibility was also proved by experimental measurements

2006-06-01

293

This paper presents a review of experimental studies performed at the Aerodynamics Department of ONERA on three-dimensional separation both in incompressible and compressible flows. These studies call upon an intensive use of Laser Doppler Velocimetry as a mean to explore complex flows including separated regions, strong vortical structures, high velocity fluctuations and shock-waves. Special effort has been made to arrive at a clear understanding of the flowfield organization by the use of modern processing techniques including color display.

Chanetz, B.; Molton, P.; Pagan, D.; Pot, T.

294

Digital Repository Infrastructure Vision for European Research (DRIVER)

Experimental and numerical studies of powder flow during the die filling stage in powder metallurgy cold compaction processes are presented. An experimental setting consisting of a horizontal pneumatically activated shoe, a vertical die and high-speed video system has been designed. The experiments show the existence of three flow regimes: continuous, transitory and discrete, which are identified in terms of the particle size, the morphology and the speed of the shoe. ...

Cante Tera?n, Juan Carlos; Riera Colom, Mari?a Dolores; Oliver Olivella, Xavier; Prado Pozuelo, Jose? Manuel

2011-01-01

295

International Nuclear Information System (INIS)

Radioisotope techniques was applied for studying the flow and transport processes in a coastal confined aquifer during an artificial recharge experiment to check the feasibility of controlling salt water intrusion by a hydrodynamic barrier. As no other water source is available, artificial recharge is done using treated wastewaters. Flow and effective velocity, hydraulic conductivity, transmissivity, diffusivity and effective porosity have been determined by means of I-131 radioisotope in single- and multi-well tests. (author)

1998-10-01

296

Development of an Industrial SPECT to Study Dynamic Behavior of Plant Process Flow

Energy Technology Data Exchange (ETDEWEB)

Radioisotope technologies are currently widely used to investigate the spatial distribution, flow pattern, and mixing characteristics of process media. It is still, however, a great challenge to obtain a satisfactory result for a multiphase flow that can be easily found in a refinery, petrochemical plant. The radioactive particle tracking (RPT) technique was recently proposed as a promising method, which can, however, supply only very limited information on the flow dynamics. Legoupil et al. developed an industrial single photon emission computed tomography (SPECT) and applied it to visualizing the flow dynamics of a process system. The industrial SPECT allows a real-time analysis of flow distribution based on the distribution of radioactive tracer injected in the system. In the present study, several different geometries of the industrial SPECT were evaluated for imaging a labscale flow system by the Monte Carlo method, in terms of imaging quality for a {sup 99m}Tc gamma radiation source. Based on the test results, an optimal geometry of the imaging system was determined for imaging the lab-scale flow system.

Park, Jang Guen; Min, Chul Hee; Kim, Chan Hyeong [Hanyang University, Seoul (Korea, Republic of); Kim, Jong Bum; Jung, Sung Hee [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2008-10-15

297

Development of an Industrial SPECT to Study Dynamic Behavior of Plant Process Flow

International Nuclear Information System (INIS)

Radioisotope technologies are currently widely used to investigate the spatial distribution, flow pattern, and mixing characteristics of process media. It is still, however, a great challenge to obtain a satisfactory result for a multiphase flow that can be easily found in a refinery, petrochemical plant. The radioactive particle tracking (RPT) technique was recently proposed as a promising method, which can, however, supply only very limited information on the flow dynamics. Legoupil et al. developed an industrial single photon emission computed tomography (SPECT) and applied it to visualizing the flow dynamics of a process system. The industrial SPECT allows a real-time analysis of flow distribution based on the distribution of radioactive tracer injected in the system. In the present study, several different geometries of the industrial SPECT were evaluated for imaging a labscale flow system by the Monte Carlo method, in terms of imaging quality for a 99mTc gamma radiation source. Based on the test results, an optimal geometry of the imaging system was determined for imaging the lab-scale flow system

2008-10-01

298

Energy Technology Data Exchange (ETDEWEB)

As part of the Oak Ridge National Laboratory's technical support to large coal liquefaction projects, attempts have been made to (1) develop the methodology for characterizing and predicting multicomponent, multiphase, non-Newtonian flow behavior within letdown valves and devices, and (2) analyze the fluid flow in the entire letdown region of the process. An engineering model that can be used in the analysis of multicomponent, multiphase, flashing, flowing systems has been developed. A preliminary version of a user-oriented computer code for this model has been developed and is fully described.

Ott, L. J.; Khan, A. A.

1982-09-01

299

Digital Repository Infrastructure Vision for European Research (DRIVER)

Continuous flow microwave heating is an emerging technology in thermal processing of liquid, viscous, or pumpable food products such as carrot puree. Carrot (Daucus carota) is one of the world's leading vegetable crops. Consumption of carrot has increased due to its pleasant flavor, nutritious content and perceived health benefits related to vitamin A. Conventional thermal processing of carrot puree requires long processing times at high temperatures to inactivate Clostridium botulinum and a...

2012-01-01

300

Phase Diagrams for Traffics on the Crossroad: II. The Cases of Different Velocities

Cell automaton simulations have been performed for the traffic flows on two one-lane roads, crossing at a point, where the maximum velocities of the northbound and the eastbound cars are different. The phase diagrams are constructed, and it has turned out that the phase diagrams consist of six regions. The obtained phase diagrams are interpreted on the basis of the local occupation probability method.

Ishibashi, Yoshihiro; Fukui, Minoru

2001-12-01

301

Method for coding and documentation of reliability block-diagram

International Nuclear Information System (INIS)

Reliability block-diagram is a widely used method in risk, availability and reliability analysis. In comparison with the faulttree method it offers many advantages, eg better functional analogy with the analyzed process. This analogy, however, easily disappears if the amount of details to be modelled is large. This paper describes a method, developed during the PRA of TVO 1, which makes it possible to create reliability block-diagrams in a hierarchial way without loosing any essential information

1986-10-01

302

The natural flow regime paradigm and parallel stream ecological concepts and theories have established the benefits of maintaining or restoring the full range of natural hydrologic variation for physiochemical processes, biodiversity, and the evolutionary potential of aquatic and riparian communities. A synthesis of recent advances in hydroecological research coupled with stream classification has resulted in a new process to determine environmental flows and assess hydrologic alteration. This process has national and international applicability. It allows classification of streams into hydrologic stream classes and identification of a set of non-redundant and ecologically relevant hydrologic indices for 10 critical sub-components of flow. Three computer programs have been developed for implementing the Hydroecological Integrity Assessment Process (HIP): (1) the Hydrologic Indices Tool (HIT), which calculates 171 ecologically relevant hydrologic indices on the basis of daily-flow and peak-flow stream-gage data; (2) the New Jersey Hydrologic Assessment Tool (NJHAT), which can be used to establish a hydrologic baseline period, provide options for setting baseline environmental-flow standards, and compare past and proposed streamflow alterations; and (3) the New Jersey Stream Classification Tool (NJSCT), designed for placing unclassified streams into pre-defined stream classes. Biological and multivariate response models including principal-component, cluster, and discriminant-function analyses aided in the development of software and implementation of the HIP for New Jersey. A pilot effort is currently underway by the New Jersey Department of Environmental Protection in which the HIP is being used to evaluate the effects of past and proposed surface-water use, ground-water extraction, and land-use changes on stream ecosystems while determining the most effective way to integrate the process into ongoing regulatory programs. Ultimately, this scientifically defensible process will help to quantify the effects of anthropogenic changes and development on hydrologic variability and help planners and resource managers balance current and future water requirements with ecological needs.

Kennen, Jonathan G.; Henriksen, James A.; Nieswand, Steven P.

2007-01-01

303

Structure and Microhardness of Steel Samples after Pulse Plasma Flows Processing

Directory of Open Access Journals (Sweden)

Full Text Available The phase structure of surfaces of steel samples, modified by pulse plasma processing, was analyzed using XRD and metallographic methods. It has been shown, that after pulse plasma processing under different conditions a modified structure consisting of three new phases, including austenite, iron nitride and carbide, is formed. The dependence of phase transition and microhardness on plasma flow parameters has been studied. A sharp decrease in the dimensions of ferrite crystallites after the impact of plasma flow is observed. The main purpose of hardening of common steel samples is formation of nano-dimension ferrite with oriented iron carbide on grains.

Anuar Zhukeshov

2013-07-01

304

Directory of Open Access Journals (Sweden)

Full Text Available Continuous flow chemical processes offer several advantages as compared to batch chemistries. These are particularly relevant in the case of heterogeneously catalyzed transformations of biomass-derived platform molecules into valuable chemicals and fuels. This work is aimed to provide an overview of key continuous flow processes developed to date dealing with a series of transformations of platform chemicals including alcohols, furanics, organic acids and polyols using a wide range of heterogeneous catalysts based on supported metals, solid acids and bifunctional (metal + acidic materials.

Antonio A. Romero

2012-07-01

305

Scientific Electronic Library Online (English)

Full Text Available SciELO Venezuela | Language: Spanish Abstract in spanish El artículo presenta la aplicación de dos enfoques no paramétricos que permiten jerarquizar procesos a partir de los múltiples indicadores que los caracterizan: el diagrama de Hasse y la teoría de conjuntos parcialmente ordenados. Procesos como la evaluación de un conjunto de proyectos de ingeniería [...] , pueden ser caracterizados por diversos atributos o indicadores que miden aspectos técnicos, financieros, sociales y ambientales, entre otros. A diferencia de otras técnicas que buscan determinar una valor agregado de calidad para cada proceso, mediante el uso de información subjetiva, las técnicas no paramétricas no requieren información adicional y permiten realizar un análisis a priori para: a) evaluar si es posible definir una única jerarquía en forma natural; b) si existen jerarquías en determinados subconjuntos de objetos; o c) si es necesario utilizar algún método que permita realizar la jerarquización únicamente mediante la información de la matriz de múltiples indicadores. Las técnicas seleccionadas se ilustran en tres ejemplos relacionados con el área de la ingeniería. Abstract in english This paper presents the application of two non-parametric approaches allowing the ranking of processes characterized by a multi-indicator matrix: the Hasse diagram and the partial order set theory. Processes like the assessment of engineering projects, are described by a set of technical, financial, [...] social and environmental attributes, among others. While parametric techniques try to determine an aggregate value for each process using subjective information, non-parametric approaches do not require additional information allowing an a priori analysis for: a) assessing if it is possible to define a unique natural ranking; b) determining if there are set of objects that could be partially ranked; or c) applying selected techniques for determine a ranking based only in the information provided by a multi-indicator matrix. The selected approaches are illustrated in three examples, related to engineering problems.

Claudio M, Rocco S; Elvis, Hernández.

306

PROBLEMS AND TERMS OF THE IMPLEMENTATION OF OPTIMAL FLOW PROCESSES MANAGEMENT

Directory of Open Access Journals (Sweden)

Full Text Available The relevance of the logistics concept concerning the solution of flow processes optimal control problems of industrial enterprises is discussed in the article. Modern tools of logistics make it possible to resolve the existing contradictions in Ukrainian economy by unifying business-structures into a single efficient system.While dealing with enterprise optimal management as a total combination of flow processes, logistics plays the main role as a regulator between an enterprise and resources market on the one hand, and an enterprise and sales market of finished goods on the other hand. Thus, there is a constant exchange (supply of matter, energy and information between the links of a continuous chain (supply chain.Such a definition as "variability" is suggested as a fundamental reason of inconsistency. The concept of variability is explained as any deviation at input / output processes from the desired ideal values. From this points of view the fundamental way to improve system efficiency is to reduce this variability.The current management of an enterprise should take into consideration integration and innovation aspects of economy. It should be based on consistency and compliance of flow processes of an enterprise, and be predictive. The conditions for implementation of optimal (logistics management of flow processes were outlined.

I. Dzobko

2012-06-01

307

Modeling Unsaturated Flow and Transport Processes in Fractured Tuffs of Yucca Mountain

International Nuclear Information System (INIS)

This paper presents a field modeling study characterizing fluid flow and tracer transport in the unsaturated zone of Yucca Mountain, Nevada, a proposed underground repository for storing high-level radioactive waste. The 500 to 700 meter thick unsaturated zone of Yucca Mountain consists of highly heterogeneous layers of anisotropic, fractured ash flow and air fall tuffs. Characterization of fluid flow and heat transfer through such a system has been a challenge due to the heterogeneities prevalent on various scales. Quantitative evaluation of water, gas, and heat flow by means of numerical simulation is essential for design and performance assessment of the repository. A three-dimensional numerical flow and transport model will be discussed. The model has been calibrated against field-measured data and takes into account the coupled processes of unsaturated flow and tracer transport in the highly heterogeneous, unsaturated fractured porous rock. The modeling approach of the model is based on a dual-continuum formulation of coupled multiphase fluid and tracer transport through fractured porous rock. As application examples, effects of current and future climates on the unsaturated zone processes are evaluated to aid in the assessment of the proposed repository's system performance

2003-09-18

308

Study of an ammonia-based wet scrubbing process in a continuous flow system

Energy Technology Data Exchange (ETDEWEB)

A continuous gas and liquid flow, regenerative scrubbing process for CO{sub 2} capture was demonstrated at the bench-scale level. An aqueous ammonia-based solution captures CO{sub 2} from simulated flue gas in an absorber and releases a nearly pure stream of CO{sub 2} in the regenerator. After the regeneration, the solution of ammonium compounds is recycled to the absorber. The design of a continuous flow unit was based on earlier exploratory results from a semi-batch reactor, where a CO{sub 2} and N{sub 2} simulated flue gas mixture flowed through a well-mixed batch of ammonia-based solution. During the semi-batch tests, the solution was cycled between absorption and regeneration steps to measure the carrying capacity of the solution at various initial ammonia concentrations and temperatures. Consequentially, a series of tests were conducted on the continuous unit to observe the effect of various parameters on CO{sub 2} removal efficiency and regenerator effectiveness within the flow system. The parameters that were studied included absorber temperature, regenerator temperature, initial NH{sub 3} concentration, simulated flue gas flow rate, liquid solvent inventory in the flow system, and height of the packed-bed absorber. From this testing and subsequent testing, ammonia losses from both the absorption and regeneration steps were quantified, and attempts were made to maintain steady state during operations. Implications of experimental results with respect to process design are discussed.

Mao, James X.; Lee, Anita S.; Kitchin, John R.; Nulwala, Hunaid B.; Luebke, David R.; Damodaran, Krishnan

2013-01-01

309

Modeling studies for multiphase fluid and heat flow processes in nuclear waste isolation

International Nuclear Information System (INIS)

Multiphase fluid and heat flow plays an important role in many problems relating to the disposal of nuclear wastes in geologic media. Examples include boiling and condensation processes near heat-generating wastes, flow of water and formation gas in partially saturated formations, evolution of a free gas phase from waste package corrosion in initially water-saturated environments, and redistribution (dissolution, transport, and precipitation) of rock minerals in non-isothermal flow fields. Such processes may strongly impact upon waste package and repository design considerations and performance. This paper summarizes important physical phenomena occurring in multiphase and nonisothermal flows, as well as techniques for their mathematical modeling and numerical simulation. Illustrative applications are given for a number of specific fluid and heat flow problems, including: thermohydrologic conditions near heat-generating waste packages in the unsaturated zone; repository-wide convection effects in the unsaturated zone; effects of quartz dissolution and precipitation for disposal in the saturated zone; and gas pressurization and flow corrosion of low-level waste packages. 34 refs; 7 figs; 2 tabs

1988-10-10

310

Automated calculation of Feynman diagrams

International Nuclear Information System (INIS)

Calculating Standard Model predictions in the context of perturbation theory is demanding. The challenge lies in the calculation of more and more complicated Feynman diagrams and in the increasing size of the calculation for scattering events with a large number of particles. New mathematical methods have to be developed and the increasing complexity has to be tamed by automatisation. A short introduction to the subject is given in chapter 2. Subsequent chapters deal with particular contributions to the solution of these problems. In chapter 3 we present a project that is going to be important for the analyses of the LHC data. The goal of the project is the calculation of oneloop corrections to processes with many particles in the final state. The numerical procedure is described and explained. It uses helicity spinors and a new tensor reduction method that avoids problems with inverse Gram determinants to a large extent. A computer program was developed that can perform the calculations automatically. The implementation is described and details about the optimization and verification are presented. Chapter 4 is concerned with analytical methods. An introduction to the xloops project is given, which can calculate various Feynman integrals analytically with arbitrary masses and momentum configurations. The major mathematical methods employed by xloops to solve the integrals are explained. Two ideas for new methods of calculation are presented. On the one hand it is the uniform treatment of one-loop N-point integrals, on the other hand it is the automated series expansion of integral solutions into higher orders of the dimensional regularization parameter ?. First results for the latter method are presented. The usefulness of the methods for automated series expansion from chapter 4 depend on the ability to numerically evaluate the expansion coefficients. The coefficients are in general multiple polylogarithms. In chapter 5 a method for the numerical evaluation of multiple polylogarithms is presented. This new method was implemented into the C++ library GiNaC together with other polylogarithms. (Orig.)

2005-01-01

311

Great Plains Gasification Project process stream design data. Final report

Energy Technology Data Exchange (ETDEWEB)

The Great Plains Coal Gasification Plant (GPGP) in the first commercial coal-to-SNG synthetic fuel plant constructed and operated in the United States. This process stream design data report provides non-proprietary information to the public on the major GPGP process streams. The report includes a simplified plant process block flow diagram, process input/output diagrams and stream design data sheets for 161 major GPGP process and effluent streams. This stream design data provides an important base for evaluation of plant and process performance and for verification of the DOE ASPEN computer simulation models of the GPGP processes. 8 refs.

Honea, F.I.

1985-09-01

312

Integration of fluid flow effects within a risk-based pipeline integrity management (PIM) process

Energy Technology Data Exchange (ETDEWEB)

A quality Pipeline Integrity Management (PIM) process is a risk based, systematic process that identifies the controls required to maintain integrity. Through the application of a risk based PIM process, limited funds and resources can be deployed in the areas of highest risk to reduce the likelihood of internal corrosion failures. The process can easily be applied to any pipeline system from the very simple to the very complex. The failure modes and effects analysis (FMEA) within the PIM process clearly identifies the pipeline function, operating envelopes, deterioration mechanisms, associated risks, and maintenance requirements. Pipeline maintenance controls identified within the PIM process are easily justified, as they are the result of a structured risk based analysis. At the heart of a successful PIM program is accurate characterization of the internal corrosion hazard profile. The paper demonstrates how two-phase flow modelling data is utilized to identify the formation of detrimental fluid flow patterns contributing to corrosive environments in sour gas pipelines, including a description of the protective scale disruption processes that underlies the technical assessment of risk within the FMEA model. Three sour gas production pipeline case studies are presented involving different situations where flow is important for corrosion considerations. (author)

Richardson, D.; McGovern, C. [NeoCorr Engineering Ltd. Calgary (Canada)

1998-07-01

313

Gas Hydrate Stability and Sampling: The Future as Related to the Phase Diagram

Digital Repository Infrastructure Vision for European Research (DRIVER)

The phase diagram for methane + water is explained, in relation to hydrate applications, such as in flow assurance and in nature. For natural applications, the phase diagram determines the regions for hydrate formation for two- and three-phase conditions. Impacts are presented for sample preparation and recovery. We discuss an international study for “Round Robin” hydrate sample preparation protocols and testing.

Dendy Sloan, E.; Koh, Carolyn A.; Sum, Amadeu K.

2010-01-01

314

Hydrodynamic viability of chemical looping processes by means of cold flow model investigation

International Nuclear Information System (INIS)

Highlights: ? Double loop circulating fluidized bed is proposed for chemical looping processes. ? Overview of the cold flow model (CFM) scaling criteria is provided. ? A full scale CFM was built for hydrodynamics validation and scale-up estimations. ? The CFM was tested resembling design conditions, off-design, reforming, etc. ? The CFM performance is described in terms of solids exchange and pressure. -- Abstract: SINTEF Energy Research and the Norwegian University of Science and Technology – NTNU have proposed a 150 kWth reactor system design aiming at further development of chemical looping processes. It consists of a double loop circulating fluidized bed, meant to be used as a platform to study atmospheric chemical looping combustion configurations, as well as other possible chemical looping processes e.g. gas turbine combustion and reforming. The hydrodynamic viability of the design needs to be tested by means of a cold flow model, operated without chemical reactions. An evaluation of the state of the art within cold flow model testing was done. It led to the choice of building a full scale (i.e. 1:1) cold model of the 150 kWth hot rig design, in order to reduce wall-effects which have considerably larger influence at smaller reactor diameters than on larger ones. The cold flow model was extensively tested and experimental results are presented. The aimed design condition, mirroring a chemical looping combustion process adapted to steam generation, was achieved successfully and in a stable way. The performance of the reactor system was further tested in off-design conditions to define operational guidelines for the hot operation. In addition, attempts were done to resemble other chemical looping processes, getting some understanding of how the reactor system may perform and consequently providing solid hydrodynamic bases to improve the design for those applications. In all cases, stable operational sets were found in order to satisfy the cold flow model hydrodynamic requirements consistently with the actual high temperature processes.

2012-09-01

315

Deriving bedform phase diagrams

Students prepare for this activity by working with a unidirectional flume with a sand bed. We adjust water depth, flow velocity, and channel slope to achieve a range of bed states, in an effort for them to understand the controls on bedforms. This portion of the activity could be done in lecture or via another exercise that makes use of digital video of actual experiments. The activity itself is a jigsaw: students form groups of three, each group responsible for plotting depth vs. velocity plots of bedform state for a single sand grain size range (0.10-0.14 mm, 0.5-0.64 mm, and 1.3-1.8 mm). These data are provided to them as Excel files and the data were directly 'stolen' from the original depth vs. velocity plots in Middleton and Southard (1984), Mechanics of Sediment Movement, SEPM Short Course Number 3. Datathief software (available free on the web) was used to steal the data. The data are arranged in columns: depth, velocity, and bedform type. Students must plot each of the different bedform types with a different symbol, then they have to define field boundaries. It is critical that they have never seen the original plots in their textbook. The goal is for them to derive them on their own, not to regurgitate what is in their textbook or elsewhere. After they complete their plots for each grain size range, the groups re-arrange themselves into groups of three with one representative from each of the grain size groups. They then must try to evaluate the effects of changing grain size on bedform state. Finally, after completing the exercise, the bedform analysis is linked to the cross stratification that is produced under conditions of high sediment fallout rates and the given bed state. The activity gives students practice working with realistic datasets, exposure to the role of physical modeling in sedimentary geology, and a chance to plot and interpret real data. Furthermore, it really solidifies the link between cross stratification and its dynamic interpretation from the rock record.

Hickson, Thomas

316

Growth and Improvement of ZnO Nanostructure Using Aged Solution by Flow Coating Process

Digital Repository Infrastructure Vision for European Research (DRIVER)

ZnO nanostructures were prepared on corning glass substrate by flow coating process with different annealing temperature from 100?C to 600?C. Fresh and two days aged solutions were used to investigate the growth behavior and to evaluate the nanostructure of ZnO. The effect of preparation conditions on the deposition of ZnO nanostructure w<...

Kasimayan Uma; Solaiappan Ananthakumar; Ramalinga Viswanathan Mangalaraja; Tetsuo Soga; Takashi Jimbo

2013-01-01

317

Regional scale analysis of the topographic signatures of landslide/debris flow dominated processes

The morphology of alpine headwater basins is strongly influenced by erosion processes. The relationship between landforms and erosion processes has been analyzed based on the relationship between slope and drainage area (Montgomery and Foufoula-Georgiou, 1993), because among parameters derived from a DTM (Digital Terrain Model), slope and drainage area are deemed to be pertinent for studying overall erosion dynamics. Thanks to LiDAR and high resolution topography now is possible to reach a better representation of hillslope morphology, and then recognize in detail the topographic signature of valley incision by landslides and debris flows (Tarolli and Dalla Fontana, 2009). In this work we present a tentative of a regional scale analysis of such signature. In the analysis we derived the slope-area relationship using high-resolution DTMs with 2.5 m cells derived from LiDAR (Light Detection and Ranging) data. We considered 23 catchments, characterized by soil-mantled landscape, and where several debris flows occurred in the year 2009. The results showed that in 83% catchments the topographic signature of debris flow processes is clearly present, while in the remaining catchments only hillslopes, unchanneled valleys and alluvial channels regions are recognized. The slope-area relationships of few catchments where no debris flows were observed during 2009 events, nor reported in the historical database, were then analyzed. For these basins the slope-area relationship does not evidence the topographic signature of debris flow processes. According to these results the presented methodology really can help for a right preliminary analysis and classification of alpine catchments based on their dominant geomorphological processes. The methodology should be used for a first and quick interpretation, in support to field surveys and more complex physically based modeling analysis.

Tarolli, P.; Righetto, A.

2012-04-01

318

Electrical elementary diagrams and operators

Energy Technology Data Exchange (ETDEWEB)

After 40 years of reading and interrupting electrical elementary logic drawings, I have concluded that we need to make a change. We need to write and express our nuclear power plant logic in some other language than relay ladder logic, solid state logic or computer mnemonics. The language should be English, or your native language, and the format should be Descriptive Block Diagrams. (author)

Patterson, B.K. [Human Factors Practical Inc., Dipper Harbour, New Brunswick (Canada)]. E-mail: HumanFactors@netscape.ca

2005-07-01

319

The nonforward QCD ladder diagrams

International Nuclear Information System (INIS)

We extend the standard analysis of the QCD planar ladder diagrams to the nonforward direction. Results are used for calculating exclusive and semiinclusive cross sections of diffractive photoproduction in the small-x region of ep-collisions. As an example we estimate the event rate for diffractive photoproduction of the neutral vector boson at Hera energies. (orig.)

1981-01-01

320

International Nuclear Information System (INIS)

The perturbation theory for the polaron energy is systematically treated on the diagrammatic basis. Feynman diagrams being constructed allow to calculate the polaron energy up to the third order in powers of the coupling constant. Similar calculations are performed for the average number of virtual phonons

1985-01-01

321

Electrical elementary diagrams and operators

International Nuclear Information System (INIS)

After 40 years of reading and interrupting electrical elementary logic drawings, I have concluded that we need to make a change. We need to write and express our nuclear power plant logic in some other language than relay ladder logic, solid state logic or computer mnemonics. The language should be English, or your native language, and the format should be Descriptive Block Diagrams. (author)

2005-06-12

322

Class Diagram Restructuring with GROOVE

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper describes the GROOVE solution to the "Class Diagram Restructuring" case study of the Tool Transformation Contest 2013. We show that the visual rule formalism enables the required restructuring to be formulated in a very concise manner. Moreover, the GROOVE functionality for state space exploration allows checking confluence. Performance-wise, however, the solution does not scale well.

2013-01-01

323

Class Diagram Restructuring with GROOVE

Directory of Open Access Journals (Sweden)

Full Text Available This paper describes the GROOVE solution to the "Class Diagram Restructuring" case study of the Tool Transformation Contest 2013. We show that the visual rule formalism enables the required restructuring to be formulated in a very concise manner. Moreover, the GROOVE functionality for state space exploration allows checking confluence. Performance-wise, however, the solution does not scale well.

Wietse Smid

2013-11-01

324

Addendum G. Feynman diagram index

International Nuclear Information System (INIS)

In Appendix G, a formula for the index of any Feynman diagram is derived within the general model of quantum field theory, whose interaction Lagrangian is a polynomial with respect to the boson and fermion fields and their derivatives. Special discussion is devoted to the interaction of boson fields with a spin of one and a nonzero mass. (Z.J.)

1993-01-01

325

Higher Order City Voronoi Diagrams

We investigate higher-order Voronoi diagrams in the city metric. This metric is induced by quickest paths in the L1 metric in the presence of an accelerating transportation network of axis-parallel line segments. For the structural complexity of kth-order city Voronoi diagrams of n point sites, we show an upper bound of O(k(n - k) + kc) and a lower bound of {\\Omega}(n + kc), where c is the complexity of the transportation network. This is quite different from the bound O(k(n - k)) in the Euclidean metric. For the special case where k = n - 1 the complexity in the Euclidean metric is O(n), while that in the city metric is {\\Theta}(nc). Furthermore, we develop an O(k^2(n + c) log n)-time iterative algorithm to compute the kth-order city Voronoi diagram and an O(nc log^2(n + c) log n)-time divide-and-conquer algorithm to compute the farthest-site city Voronoi diagram.

Gemsa, Andreas; Liu, Chih-Hung; Wagner, Dorothea

2012-01-01

326

Voronoi Diagrams and Spring Rain

The goal of this geometry project is to use Voronoi diagrams, a powerful modeling tool across disciplines, and the integration of technology to analyze spring rainfall from rain gauge data over a region. In their investigation, students use familiar equipment from their mathematical toolbox: triangles and other polygons, circumcenters and…

Perham, Arnold E.; Perham, Faustine L.

2011-01-01

327

Phase diagram of electroweak theory

Energy Technology Data Exchange (ETDEWEB)

There is some controversy in the literature concerning the phase diagram of electroweak theory, particularly when {ital W}-boson condensation occurs. Problems with previous calculations are pointed out and the thermodynamic potential is recalculated. Limitations of current theoretical approaches are found and suggestions are made on how to improve the approximations, especially at high temperature and high density.

Kapusta, J.I. (School of Physics, Minneapolis, (MN) Astronomy, University of Minnesota, Minneapolis, MN (USA))

1990-08-01

328

Algorithmic approach to diagram techniques

International Nuclear Information System (INIS)

An algorithmic approach to diagram techniques of elementary particles is proposed. The definition and axiomatics of the theory of algorithms are presented, followed by the list of instructions of an algorithm formalizing the construction of graphs and the assignment of mathematical objects to them. (T.A.)

1980-01-01

329

Analytic Combinatorics of Chord Diagrams

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this paper we study the enumeration of diagrams of n chords joining 2n points on a circle in disjoint pairs. We establish limit laws for the following three parameters: number of components, size of the largest component, and number of crossings. We also find exact formulas for the moments of the distribution of number of components and number of crossings.

Flajolet, Philippe; Noy, Marc

2000-01-01

330

International Nuclear Information System (INIS)

This study presents the development of an image processing technique for studying the dynamic behavior of vapor bubbles in a two-phase bubbly flow. It focuses on the quantitative assessment of some basic parameters such as a local bubble size and size distribution in the range of void fraction between 0.03 < a < 0.07. The image processing methodology is based upon the computer evaluation of high speed motion pictures obtained from the flow field in the region of underdeveloped subcooled flow boiling for a variety of experimental conditions. This technique has the advantage of providing computer measurements and extracting the bubbles of the two-phase bubbly flow. This method appears to be promising for determining the governing mechanisms in subcooled flow boiling, particularly near the point of net vapor generation. The data collected by the image analysis software can be incorporated into the new models and computer codes currently under development which are aimed at incorporating the effect of vapor generation and condensation separately. (author)

1998-09-01

331

Power Network Voronoi Diagram and Dynamic Construction

Directory of Open Access Journals (Sweden)

Full Text Available Objective Voronoi diagrams are important in many fields in a series of sciences. Network Voronoi diagrams are useful to investigate dominance regions in a grid street system or a radial-circular street system. However, all generators may have different effect. To deal with a network Voronoi diagram with varied functions of generators, it must be worth formulating a power network Voronoi diagram. Method Adding weight value on generators, which is used to indicate factors related to are difficult to construct when the position relation of generators. Results A new concept of power network Voronoi diagram are proposed. In accordance with discrete construction method, achieved the construction of power network Voronoi diagram. Conclution The application example shows that the algorithm is both simple and useful, and it is of high potential value in practice. Power network Voronoi diagram both perfected the theory about Voronoi diagrams, and extended the range of applications of Voronoi diagrams.

Yourong Wang

2012-04-01

332

Two mechanisms for optic flow and scale change processing of looming

The detection of looming, the motion of objects in depth, underlies many behavioral tasks, including the perception of self-motion and time-to-collision. A number of studies have demonstrated that one of the most important cues for looming detection is optic flow, the pattern of motion across the retina. Schrater et al. have suggested that changes in spatial frequency over time, or scale changes, may also support looming detection in the absence of optic flow (P. R. Schrater, D. C. Knill, & E. P. Simoncelli, 2001). Here we used an adaptation paradigm to determine whether the perception of looming from optic flow and scale changes is mediated by single or separate mechanisms. We show first that when the adaptation and test stimuli were the same (both optic flow or both scale change), observer performance was significantly impaired compared to a dynamic (non-motion, non-scale change) null adaptation control. Second, we found no evidence of cross-cue adaptation, either from optic flow to scale change, or vice versa. Taken together, our data suggest that optic flow and scale changes are processed by separate mechanisms, providing multiple pathways for the detection of looming.

Calabro, Finnegan J.; Rana, Kunjan D.; Vaina, Lucia M.

2013-01-01

333

CP and T Trajectory Diagrams for a Unified Graphical Representation of Neutrino Oscillations

Recently the CP trajectory diagram was introduced to demonstrate the difference between the intrinsic CP violating effects to those induced by matter for neutrino oscillation. In this paper we introduce the T trajectory diagram. In these diagrams the probability for a given oscillation process is plotted versus the probability for the CP- or the T-conjugate processes, which forms an ellipse as the CP or T violating phase is varied. Since the CP and the T conjugate processes are related by CPT symmetry, even in the presence of matter, these two trajectory diagrams are closely related with each other and form a unified description of neutrino oscillations in matter.

Minakata, H; Parke, S; Minakata, Hisakazu; Nunokawa, Hiroshi; Parke, Stephen

2002-01-01

334

Energy Technology Data Exchange (ETDEWEB)

Imaging flows embedded in structural objects has become increasingly important in industrial processes for the control and the optimization of the process inside of the apparatus involved. Here, a tomographic technique applied to fluid flow visualization is described. For industrial purposes, a relatively high energy tracer has to be used (200 keV to 2 MeV). The procedure implies the comprehension of the detection process relative to geometric response, attenuation, and scatter. This has been achieved by Monte Carlo investigations for four typical media. The formulation of a physical model allowed a set of weighting factors that were incorporated in the reconstruction algorithm. Experimental projections were compared to simulated projections for Monte Carlo validation. Results show that reconstruction of these data from a very limited number of projections is hopeful.

Legoupil, S.; Pascal, G.; Chambellan, D. [CEA CEN Saclay, Gif-sur-Yvette (France); Bloyet, D. [ISMRA-LEI, Caen (France)

1996-04-01

335

Analysis of the mist lift process for mist flow open-cycle OTEC

Energy Technology Data Exchange (ETDEWEB)

Preliminary results are presented of a numerical analysis to study the open-cycle mist flow process for ocean thermal energy conversion (OTEC). Emphasis in the analysis is on the mass transfer and fluid mechanics of the steady-state mist flow. The analysis is based on two one-dimensional models of the mist lift process: a single-group model describes a mist composed of a single size of drops and a multigroup model considers a spectrum of drop sizes. The single-group model predicts that the lift achieved in the mist lift process will be sensitive to the inlet parameters. Under conditions that lead to maximum lift in the model for a single drop size, the multigroup model predicts significantly reduced performance. Because the growth of drops is important, sensitivity of the predicted performance of the mist lift to variations in the collision parameters has been studied.

Davenport, R. L.

1980-06-01

336

International Nuclear Information System (INIS)

This paper examines the conceptualization of multiphase flow processes on the macroscale, as needed in field applications. It emphasizes that upscaling from the pore-level will in general not only introduce effective parameters but will also give rise to ''effective processes,'' i.e., the emergence of new physical effects that may not have a microscopic counterpart. ''Phase dispersion'' is discussed as an example of an effective process for the migration and remediation of non-aqueous phase liquid (NAPL) contaminants in heterogeneous media. An approximate space-and-time scaling invariance is derived for gravity-driven liquid flow in unsaturated two-dimensional porous media (fractures). Issues for future experimental and theoretical work are identified

1995-09-25

337

Normal-flow virus filtration: detection and assessment of the endpoint in bio-processing.

The breakthrough of a model virus, bacteriophage PhiX-174, through normal-flow virus filters was studied using both commercial process fluids and model feed streams. The results indicate that (i) PhiX-174 is a reasonable model for a mammalian parvovirus [MMV (murine minute virus)] in virus filtration studies; (ii) PhiX-174 LRV [log(reduction value)] shows a better correlation with percentage flow decline compared with volume processed under a variety of conditions; (iii) although the extent of decline in virus LRV is dependent on the mechanism of filter fouling, the fouling mechanisms operative in a viral validation study are representative of those likely to be found under actual production conditions. The mechanism of LRV decline by many process streams was proposed to be due to selective plugging of small pores. A theoretical model as well as a predictive equation for LRV decline versus flow decay was derived; experimental results from filtration studies using pore-plugging feed stocks were consistent with the equation. As protein solutions may vary in their adsorptive versus plugging behaviour during filtration, an evaluation of the LRV-versus-flow-decay relationship on a biopharmaceutical-product-specific basis may be warranted. PMID:15901236

Bolton, Glen; Cabatingan, Mark; Rubino, Mike; Lute, Scott; Brorson, Kurt; Bailey, Mark

2005-10-01

338

TERRAIN: A computer program to process digital elevation models for modeling surface flow

Energy Technology Data Exchange (ETDEWEB)

This document provides a step by step procedure, TERRAIN, for processing digital elevation models to calculate overland flow paths, watershed boundaries, slope, and aspect. The algorithms incorporated into TERRAIN have been used at two different geographic scales: first for small research watersheds where surface wetness measurements are made, and second for regional water modeling for entire counties. For small areas methods based on flow distribution may be more desirable, especially if time-dependent flow models are to be used. The main improvement in TERRAIN compared with earlier programs on which it is based is that it combines the conditioning routines, which remove depressions to avoid water storage, into a single process. Efficiency has also been improved, reducing run times as much as 10:1 and enabling the processing of very large grids in strips for regional modeling. Additionally, the ability to calculate the nutrient load delivered any cell in a watershed has been added. These improvements make TERRAIN a powerful tool for modeling surface flow.

Schwartz, P.M.; Levine, D.A.; Hunsaker, C.T. [Oak Ridge National Lab., TN (United States). Environmental Sciences Div.; Timmins, S.P. [Analysas Corp., Oak Ridge, TN (United States)

1995-08-01

339

Evaluation of alternative flow sheets for upgrade of the Process Waste Treatment Plant

International Nuclear Information System (INIS)

Improved chemical precipitation and/or ion-exchange (IX) methods are being developed at the Oak Ridge National Laboratory (ORNL) in an effort to reduce waste generation at the Process Waste Treatment Plant (PWTP). A wide variety of screening tests were performed on potential precipitation techniques and IX materials on a laboratory scale. Two of the more promising flow sheets have been tested on pilot and full scales. The data were modeled to determine the operating conditions and waste generation at plant-scale and used to develop potential flow sheets for use at the PWTP. Each flow sheet was evaluated using future-valve economic analysis and performance ratings (where numerical values were assigned to costs, process flexibility and simplicity, stage of development, waste reduction, environmental and occupational safety, post-processing requirements, and final waste form). The results of this study indicated that several potential flow sheets should be considered for further development, and more detailed cost estimates should be made before a final selection is made for upgrade of the PWTP. 19 refs., 52 figs., 22 tabs

1991-01-01

340

A Semi-Markov Process based Optimization Method for Availability of Hybrid Flow Shop

Directory of Open Access Journals (Sweden)

Full Text Available As Hybrid Flow Shops (HFS are common manufacturing environments, availability of HFS is a basic indicator for measuring usage ability. Optimal maintenance strategy which achieves maximum availability with cost constraints, provides a better platform for its scheduling problems. We propose an availability model in this study by using Semi-Markov Process (SMP under a general maintenance strategy which suit for general distribution of machines’ life time distribution and maintenance time distribution. Based on the availability model, the maintenance site configuration optimization method is with total cost constrains. Furthermore, the method is applied to a simple hybrid flow shop and showed to be effective.

Fei Simiao

2013-01-01

341

POWER FLOW ANALYSIS OF A CONTINUOUS PROCESS PLANT: (A CASE STUDY

Directory of Open Access Journals (Sweden)

Full Text Available For the continuous evaluation of the performance of the power system, power flow solutions are essential for exhibiting suitable control actions in case of requirement. This case study presents analysis of the electrical power system of continuous process plant having its own captive generation along with the provision of the Grid connectivity. The different power system elements are modeled as per the manufacturer’s data sheet. To evaluate the steady state performance, power flow simulations and analysis of the complex power system for various invasive operating conditions are carried out.

SMITA ACHARYA, PRAGATI GUPTA, M.A.MUJAWAR

2013-06-01

342

Energy Technology Data Exchange (ETDEWEB)

This is final report for contract DE-AC26-99BC15211. The report describes progress made in the various thrust areas of the project, which include internal drives for oil recovery, vapor-liquid flows, combustion and reaction processes and the flow of fluids with yield stress. The report consists mainly of a compilation of various topical reports, technical papers and research reports published produced during the three-year project, which ended on May 6, 2002 and was no-cost extended to January 5, 2003. Advances in multiple processes and at various scales are described. In the area of internal drives, significant research accomplishments were made in the modeling of gas-phase growth driven by mass transfer, as in solution-gas drive, and by heat transfer, as in internal steam drives. In the area of vapor-liquid flows, we studied various aspects of concurrent and countercurrent flows, including stability analyses of vapor-liquid counterflow, and the development of novel methods for the pore-network modeling of the mobilization of trapped phases and liquid-vapor phase changes. In the area of combustion, we developed new methods for the modeling of these processes at the continuum and pore-network scales. These models allow us to understand a number of important aspects of in-situ combustion, including steady-state front propagation, multiple steady-states, effects of heterogeneity and modes of combustion (forward or reverse). Additional aspects of reactive transport in porous media were also studied. Finally, significant advances were made in the flow and displacement of non-Newtonian fluids with Bingham plastic rheology, which is characteristic of various heavy oil processes. Various accomplishments in generic displacements in porous media and corresponding effects of reservoir heterogeneity are also cited.

Yannis C. Yortsos

2003-02-01

343

Trigeneration System: Visualization through Ternary Diagrams

Directory of Open Access Journals (Sweden)

Full Text Available The simultaneous production of power, heat and refrigeration in trigeneration plants is potentially more efficient than producing these same utilities in separate facilities, mainly due to the increased opportunities for process integration. Hence, trigeneration is also inherently more cost-effective and thermodynamically efficient, resulting in lower CO2 footprint. Various methods have been developed for the synthesis of such plants. In this study, we propose a graphical approach where power, heat and refrigeration or cooling form the vertices of a ternary diagram. A thermal process unit may thus be represented as a point within the ternary diagram, with its coordinates denoting the ratios of its heat, power and cooling outputs. Thus, units producing two streams lie along the edges of the triangular field while those producing three streams fall inside it. Subsequently sizing of such process units that make up a trigeneration plant can be accomplished using lever-arm mixing rules within this triangular coordinate system. The use of the graphical methodology is illustrated with two case studies.

R.R. Tan

2014-01-01

344

Upscaling of two-phase flow processes in CO2 geological storage

Only few current multiphase flow and reactive transport models take into account the impact of heterogeneity on front spreading and mass transfer between high and low permeability zones of the heterogeneous medium and the impact of physical heterogeneity and chemical heterogeneity on chemical reactions rates. Effective equations are available for single-phase conservative and reactive transport and under development for multiphase flow. In the present work, we aim specifically at the upscaling of the two-phase flow dynamics related to processes of CO2 geological storage. The impact of heterogeneity on the two-phase flow dynamics can be quantified in the framework of a multi-continuum approach. This approach allows for the quantification of mass exchange between mobile (background material) and immobile (inclusions) zones of the medium. In this way it accounts systematically for local scale non-equilibrium and thus for the complex flow dynamics in highly heterogeneous and fractured media. The mass exchange between mobile and immobile zones is taken into account by a Multi-Rate Mass Transfer (MRMT) model. Effective equations were formulated in order to describe the impact of spatial heterogeneity on the large-scale two-phase flow behavior. The model was implemented into a MatLab code. Heterogeneity in the hydraulic conductivity of the storage aquifer was accounted through a Gaussian random field. Numerical simulations of 2D two-phase flow through this heterogeneous media were run to obtain the evolution of the actual CO2-rich phase saturation distribution. An equivalent effective model of 1D two-phase flow in homogenous media with MRMT was used to describe the 2D heterogeneous results. The numerical simulations show that a simple 1D homogeneous model with MRMT, capillarity at mobile-immobile interface and in the mobile zone is able to describe two-phase flow in heterogeneous media. However, gravity and macrodispersion terms still have to be included. Extension to heterogeneous multiphase flow is straightforward. The present methodology could contribute significantly to the quantification of the heterogeneity-induced uncertainty of the predicted large-scale multiphase flow and transport behavior in CO2 geological storage.

Silva, O.; Neuweiler, I.; Dentz, M.; Saaltink, M.; Carrera, J.

2012-04-01

345

Electrical CT image reconstruction technique for powder flow in petroleum refinery process

A new reconstruction method called sampled pattern matching (SPM) was applied to the image reconstruction of an electrical capacitance computed tomography in powder flow in a vertical pipe for petroleum refinery process. This new method is able to achieve stable convergence without the use of an empirical value. Experiments were carried out using fluid catalytic cracking (FCC) catalysts as powder with two air volume flow rates and four powder volume flow rates to measure the capacitance of a pipe cross section. The SPM method is compared with conventional methods in terms of volume fraction, residual capacitance, and correlation capacitance. Overall, the SPM method proved superior to conventional methods without any empirical value because SPM achieves accurate reconstruction by using an objective function that is calculated as the inner product calculation between the experimental capacitance and the reconstructed image capacitance.

Takei, Masahiro; Doh, Deog-Hee; Ochi, Mitsuaki

2008-03-01

346

Basics of introduction to Feynman diagrams and electroweak interactions physics

International Nuclear Information System (INIS)

The Feynman diagrams are the main computational method for the evaluation of the matrix elements of different processes. Although it is a perturbative method, its significance is not restricted to perturbation theory only. In this book, the elements of quantum field theory, the Feynman diagram method, the theory of electroweak interactions and other topics are discussed. A number of classical weak and electroweak processes are considered in details. This involves, first of all, the construction of the matrix elements of the process using both the Feynman diagram method (when perturbation theory can be applied) and the invariance principles (when perturbation theory fails). Then the cross sections and the decay probabilities are computed. The text is providing widely used computational techniques and some experimental data. (A.B.). 32 refs., 7 appendix

1994-01-01

347

Signal processing and statistical descriptive reanalysis of steady state chute-flow experiments

An accurate knowledge of snow rheology is needed for the mitigation against avalanche hazard. Indeed snow avalanches have a significant impact on the livelihoods and economies of alpine communities. To do so, 60 small-scale in-situ flow experiments were performed with various slopes, temperatures and flow depths. The investigation of these data previously seemed to show the dense flow of dry snow may be composed of two layers; a sheared basal layer made of single snow grains and a less sheared upper layer made of large aggregates. These outcomes were mainly based on the mean velocity profile of the flow and on interpretation in terms of rheological behavior of granular materials and snow microstructure [Pierre G. Rognon et al., 2007]. Here, the main objective remains the same, but the rheological and physical viewpoints are put aside to extract as much information contained in the data as possible various using signal processing methods and descriptive statistics methods as the maximum overlap discrete wavelet transform (MODWT), transfer entropy (TE) and maximum cross-correlation (MCC). Specifically, we aim at the improving the velocity estimations as function of the depth particularly the velocity fluctuations around the mean profile to better document the behavior of dense dry snow flows during a steady and uniform chute regime. The data are composed of pairs of voltage signals (right and left), which makes that the velocity is known indirectly only. The MCC method is classically used to determine the time lag between both signals. Previously, the MCC method that showed the mean velocity profile may be fitted by a simple bilinear function [Pierre G. Rognon et al., 2007], but no interesting temporal dynamics could be highlighted. Hence, a new process method was developed to provide velocity series with much better temporal resolution. The process is mainly made of a MODWT-based denoising method and the choice of window size for correlation. The results prove to be good enough in term of reasonable variability and measurement numbers. A statistical descriptive analysis of the velocity results shows a disagreement with the previous outcomes. Indeed, the clustering method and the empirical probability distribution functions show that the vertical velocity profile may reflect three different behaviors, possibly corresponding to three layers and/or to transient flow layers. These flow layers are located at different heights depending on initial conditions of flow experiments (temperature, slope and depth). Keywords: Maximum cross correlation, MODWT, probability distribution function

truong, hoan; eckert, nicolas; keylock, chris; naaim, mohamed; bellot, hervé

2014-05-01

348

Developing a method for digital image processing of two phase fluid flows

International Nuclear Information System (INIS)

A new image processing technique was developed in the current study to understand the effects of various hydrodynamics and geometric parameters on local phase distribution phenomena in non-equilibrium two-phase flow systems. While image processing has been employed extensively in velocimetry, its application to explain the two-phase flow phenomena is new. The present study consisted of developing the technique and using it to extract phase distribution data. This, technique presents an advantage of providing measurements and extracting the bubbles of the two-phase bubbly flow compared with the traditionally used methods: point by point measurement technique or digitization. The image processing method proposed in this study is based on the detachment and tracing of the edges of the bubbles and their background. The conclusions are summarized below. (i) High speed photographic results show different behaviors of the bubbles. Some bubbles slide along the wall and detach by rapid ejection into the flow. The motion of these bubbles into the liquid core cause a violent agitation of the liquid near the heated surface. It was also noted that some bubbles detach the surface and sweep downstream and recondensing slowly in the bulk flow. This difference in bubble behavior indicates that the ejection mechanism is influenced by hydrodynamics or thermal condition and will be of interest for further study. (ii) Vapor bubble departure diameters in forced convection subcooled boiling, have been experimentally obtained over a range of mass flux, D, and heat flux, qw, for the subcooled flow boiling region. (iii) For the flow conditions experimentally investigated, the overwhelming majority of the bubbles leave the nucleation sites by sliding a finite distance along the heating surface lifting off the wall. The results can be utilized in explaining the mechanism of subcooled nucleate flow boiling especially in determining the dynamics of the local void distribution and void behavior, particularly, near the point of net vapor generation. The values of the bubble size and shape, interfacial area, information about void formation. bubble growth or collapse and its size and position as well as the velocity of the bubbles for particular conditions, are also evaluated. (Original)

1999-01-01

349

Subsurface flow constructed wetlands (SFCWs) have proven to be an efficient ecological technology for the treatment of various kinds of wastewaters. The clogging issue is the main operational problem, which limits its wide application. Clogging is a complicated process with physical (such as physical filtration), biogeochemical and plant-related processes. It was generally stated that suspended solids accumulation and biofilm play dominant roles response for clogging. However, the role of plants in SFCWs clogging remains unclear and debatable. In this paper, the performance of plants in the whole clogging process was addressed based on the lab-experiments between planted and unplanted system by measuring effective porosity, coefficient of permeability of the substrate within different operation periods. Furthermore, flow pattern and transport properties of the clogging process in the planted and unplanted wetland systems were evaluated by hydraulic performance (e.g. mean residence time, short-circuiting, volumetric efficiency, number of continuously stirred tank reactors, hydraulic efficiency factor, etc.) with salt tracer experiments. Plants played different roles in different clogging stage. In the earlier clogging stage, there were no obvious different effects on clogging process between planted and unplanted system. The effective porosity and coefficient of permeability slightly decreased within the planted system, which indicated that plant root restricted the flow of water when the pore spaces were lager. In the middle and later clogging stage, especially, in the later stage, the effective porosity and the coefficient of permeability increased considerably in the plant root zone. Furthermore, the longer retention times and higher hydraulic efficiency factors were gained in the planted system compared to that of unplanted, which implied that growing roots might open the new pore spaces in the substrate. The results are expected to be useful in the design of constructed wetland. Key words: clogging; plant root; salt tracers; hydraulic performance; subsurface flow constructed wetlands

Hua, Guofen; Zhao, Zhongwei; Zeng, Yitao

2013-04-01

350

Numerical simulations of the laminar-turbulent transition process in plane Poiseuille flow

International Nuclear Information System (INIS)

Laminar-turbulent transition in plane Poiseuille flow is simulated by numerical integration of the time-dependent three-dimensional Navier-Stokes equations for incompressible flow. The mathematical model of a spatially periodic, timewise developing flow in a moving frame of reference is used to match vibrating-ribbon experiments of Nishioka et al. The numerical discretisation is based on a spectral method with Fourier and Chebyshev polynomial expansions in space and second order finite differences in time. The pressure is calculated using a new method which enforces incompressibility and boundary conditions exactly. This is achieved by deriving the correct boundary conditions for the pressure Poisson equation. The numerical results obtained for two-dimensional finite amplitude disturbances are consistent with nonlinear stability theory. The time-periodic secondary flow is attained by the time-dependent calculation with reasonable accuracy after a long quasi-steady state. No sign of two-dimensional instability, but strong three-dimensional instability as well of the periodic secondary flow as of the quasi-steady state is found. This secondary three-dimensional instability is shown to be responsible for transition. It is shown that the three-dimensional simulations presented here reproduce the experimentally observed transition process up to the spike stage. Detailed comparisons with measurements of mean velocity, rms-values of fluctuation and instantaneous velocity distribution reveal very satisfactory agreement. The formation of peak-valley structure, longitudinal vortices, local high-shear layers and distinct spike-type signals is shown. In addition, the three-dimensional flow field structure before breakdown is investigated. An array of horseshoe vortices similar to those inferred from boundary layer flow visualization experiments is found. Spike signals are produced by local accumulations of low-speed fluid in the downstream loops of these vortices. (orig.)

1982-01-01

351

International Nuclear Information System (INIS)

Geysering may be induced during start-up in natural circulation boiling water reactors. It is necessary for simulation of this flow instability to model the coalescence mechanism and condensation process of slug bubbles. In this work, image data processing technique using a digital video camera has been developed to measure slug flow characteristics. The developed measurement technique velocity field in the wake region and liquid film velocity surrounding a slug bubble and its measurement accuracy are discussed in this paper. (author)

1999-07-01

352

Great Plains Gasification Project process stream design data. [Lurgi Process

Energy Technology Data Exchange (ETDEWEB)

The Great Plains Coal Gasification Plant (GPGP) is the first commercial coal-to-synthetic natural gas plant constructed and operated in the United States. This process stream design data report provides non-proprietary information to the public on the major GPGP process streams. The report includes a simplified plant process block flow diagram, process input/output diagrams, and stream design data sheets for 161 major GPGP process and effluent streams. This stream design data provides an important base for evaluation of plant and process performance and for verification of the Department of Energy's ASPEN (Advanced System for Process Engineering) computer simulation models of the GPGP processes. 8 refs., 22 figs., 2 tabs.

Honea, F.I.

1985-09-01

353

A numerical investigation of the resin flow front tracking applied to the RTM process

Directory of Open Access Journals (Sweden)

Full Text Available Resin Transfer Molding (RTM is largely used for the manufacturing of high-quality composite components and the key stage during processing is the resin infiltration. The complete understanding of this phenomenon is of utmost importance for efficient mold construction and the fast production of high quality components. This paper investigates the resin flow phenomenon within the mold. A computational application was developed to track the resin flow-front position, which uses a finite volume method to determine the pressure field and a FAN (Flow Analysis Network technique to track the flow front. The mass conservation problem observed with traditional FE-CV (Finite Element-Control Volume methods is also investigated and the use of a finite volume method to minimize this inconsistency is proposed. Three proposed case studies are used to validate the methodology by direct comparison with analytical and a commercial software solutions. The results show that the proposed methodology is highly efficient to determine the resin flow front, showing an improvement regarding mass conservation across volumes.

Jeferson Avila Souza

2011-09-01

354

Comparison of Navier-Stokes and DSMC Gas Flow Models in Semiconductor Process Chambers

Validated, fast turnaround simulations of flows in the transition regime are of significant use as computer-aided design tools for the design of vacuum systems in low-pressure semiconductor processing equipment. This work compares a generic Navier-Stokes flow solution (CFD) using slip boundary conditions to previous simulations from a DSMC code and data taken in an instrumented vacuum test cell typical of semiconductor equipment chambers. The CFD solution matched up as well or better than the previous DSMC simulations at pressures and flows between 1 and 5 millitorr and 100 and 500 SCCM of nitrogen, respectively. This good agreement is seen because even though the mean free path at the lowest pressure is about 5 centimeters, the local Knudsen number is smaller than 0.1 in the flow, which is a generally accepted upper limit for applicability of CFD solutions with slip boundary conditions. Since CFD solutions can be obtained an order of magnitude or more faster than corresponding DSMC solutions, the CFD approach can be used to speed up design turnaround times. Additionally, there are no commercially available DSMC codes with the support and ease-of-use features that are seen in many CFD software packages, which are already in common use in the semiconductor equipment industry. Hence, such a validated CFD approach to computing transition regime flows in vacuum chambers can be seen as a preferred design tool in industrial environments, particularly when models need to be three-dimensional and/or require complex geometrical constructs.

Gochberg, Lawrence. A.

2003-05-01

355

High-power transverse flow CW CO 2 laser for material processing applications

A transverse flow transversely excited (TFTE) CW CO 2 with a maximum output power about 15 kW has been developed. This is excited by pulser sustained DC discharge applied between a pair of multi-pins anodes and a common tubular cathode. Though the laser power in convective cooled CO 2 laser scales proportionally with the volumetric gas flow, it did not increase in this laser when the volumetric gas flow was increased by increasing the electrode separation keeping the flow velocity constant. The discharge voltage too remained almost unchanged with increase of the electrode separation. These observations are explained considering the electrical discharge being controlled by ionization instability. Laser materials processing applications often demand programming facilities for laser power modulation. A four-stage cascaded multilevel DC-DC converter-based high-frequency switch mode power supply has been developed to modulate the output power of the laser. Laser was operated up to 15 kW output power in four different modes viz. continuous wave mode, pulse periodic mode, single shot mode and processing velocity-dependent power mode with 1.2 kHz modulation bandwidth. We describe briefly the laser system, the SMPS, and the temporal behavior of laser beam.

Nath, A. K.; Reghu, T.; Paul, C. P.; Ittoop, M. O.; Bhargava, P.

2005-06-01

356

Batch-processed carbon nanotube wall as pressure and flow sensor

International Nuclear Information System (INIS)

A pressure and flow sensor based on the electrothermal-thermistor effect of a batch-processed carbon nanotube wall (CNT wall) is presented. The negative temperature coefficient of resistance (TCR) of CNTs and the temperature dependent tunneling rate through the CNT/silicon junction enable vacuum pressure and flow velocity sensing because the heat transfer rate between CNTs and the surrounding gas molecules differs depending on pressure and flow rate. The CNT walls are synthesized by thermal chemical vapor deposition (CVD) on an array of microelectrodes fabricated on a silicon-on-insulator (SOI) wafer. The CNTs are self-assembled between the microelectrodes and substrate across the thickness of a buried oxide layer during the synthesis process, and the simple batch fabrication results in high throughput and yield. A wide pressure range, down to 3 x 10-3 from 105 Pa, and a nitrogen flow velocity range between 1 and 52.4 mm s-1, are sensed. Further experimental characterizations of the bias voltage dependent response of the sensor as a vacuum pressure gauge are presented.

2010-03-12

357

Modifications to the Conduit Flow Process Mode 2 for MODFLOW-2005

As a result of rock dissolution processes, karst aquifers exhibit highly conductive features such as caves and conduits. Within these structures, groundwater flow can become turbulent and therefore be described by nonlinear gradient functions. Some numerical groundwater flow models explicitly account for pipe hydraulics by coupling the continuum model with a pipe network that represents the conduit system. In contrast, the Conduit Flow Process Mode 2 (CFPM2) for MODFLOW-2005 approximates turbulent flow by reducing the hydraulic conductivity within the existing linear head gradient of the MODFLOW continuum model. This approach reduces the practical as well as numerical efforts for simulating turbulence. The original formulation was for large pore aquifers where the onset of turbulence is at low Reynolds numbers (1 to 100) and not for conduits or pipes. In addition, the existing code requires multiple time steps for convergence due to iterative adjustment of the hydraulic conductivity. Modifications to the existing CFPM2 were made by implementing a generalized power function with a user-defined exponent. This allows for matching turbulence in porous media or pipes and eliminates the time steps required for iterative adjustment of hydraulic conductivity. The modified CFPM2 successfully replicated simple benchmark test problems. ?? 2011 The Author(s). Ground Water ?? 2011, National Ground Water Association.

Reimann, T.; Birk, S.; Rehrl, C.; Shoemaker, W. B.

2012-01-01

358

REPRESENTING MARKOV CHAINS WITH TRANSITION DIAGRAMS

Directory of Open Access Journals (Sweden)

Full Text Available Stochastic processes have many useful applications and are taught in several university programmes. Students often encounter difficulties in learning stochastic processes and Markov chains, in particular. In this article we describe a teaching strategy that uses transition diagrams to represent a Markov chain and to re-define properties of its states in simple terms of directed graphs. This strategy utilises the studentsâ?? intuition and makes the learning of complex concepts about Markov chains faster and easier. The method is illustrated by worked examples. The described strategy helps students to master properties of finite Markov chains, so they have a solid basis for the study of infinite Markov chains and other stochastic processes.

Farida Kachapova

2013-01-01

359

Reliability computation from reliability block diagrams

Computer program computes system reliability for very general class of reliability block diagrams. Four factors are considered in calculating probability of system success: active block redundancy, standby block redundancy, partial redundancy, and presence of equivalent blocks in the diagram.

Chelson, P. O.; Eckstein, E. Y.

1975-01-01

360

Quark diagrams and the ?- nonleptonic decays

International Nuclear Information System (INIS)

The quark-diagram model for nonleptonic two-body baryon decays is discussed and applied to the decay of the ?- particle. Current algebra is not employed, but the relation between the quark diagrams and current algebra is explored

1980-09-01

361

Potts Models on Feynman Diagrams

We investigate numerically and analytically Potts models on ``thin'' random graphs -- generic Feynman diagrams, using the idea that such models may be expressed as the N --> 1 limit of a matrix model. The thin random graphs in this limit are locally tree-like, in distinction to the ``fat'' random graphs that appear in the planar Feynman diagram limit, more familiar from discretized models of two dimensional gravity. The interest of the thin graphs is that they give mean field theory behaviour for spin models living on them without infinite range interactions or the boundary problems of genuine tree-like structures such as the Bethe lattice. q-state Potts models display a first order transition in the mean field for q>2, so the thin graph Potts models provide a useful test case for exploring discontinuous transitions in mean field theories in which many quantities can be calculated explicitly in the saddle point approximation.

Johnston, D A

1997-01-01

362

International Nuclear Information System (INIS)

The dynamic simulation code for the H2SO4 distillation process was developed by the KAERI research group in 2007. The analysis and design of the input and output attributes are usually required for the effective compilation of the dynamic simulation program. The Data Flow Diagram (DFD) and the class diagram have been used for the analysis and design of the input and output attributes. In this paper, the data flows for dynamic simulation of the H2SO4 distillation process have been embodied by using the DFD and the input and output attributes have also been defined by using the class diagram

2009-10-01

363

An evaluation of the rate-controlling flow process in Newtonian creep of polycrystalline ice

International Nuclear Information System (INIS)

Using experimental data and theoretical calculation for Newtonian creep in polycrystalline ice, it is demonstrated that unlike most other materials, in which the rate-controlling flow process is edge dislocation climb under saturated condition, the rate-controlling flow process of polycrystalline ice is dislocation glide along the basal plane under a constant dislocation density. The dislocation density during Newtonian creep of ice is determined by the initial state instead of the magnitude of the Peierls stress. The transition stress (threshold) from power-law creep to Newtonian creep is controlled by the dislocation density instead of the Peierls stress. The activation energy of the Newtonian creep is similar to that of the self-diffusion due to the requirements of the diffusion of protons during dislocation glide

2008-07-15

364

Numerical simulation on the dynamical stall process of airfoils in transonic flow

Energy Technology Data Exchange (ETDEWEB)

In this paper, a method is presented to simulate the dynamic stall process of airfoils in transonic flow. The flowfield around the oscillating airfoil is analyzed by solving the two-dimensional time averaged compressible Navier-Stokes equations with the Baldwin-Lomax turbulence model. An implicit Lower-Upper-factorized algorithm is constructed in a body-fitted coordinate system. In the algorithm, an improved NND (Non-oscillatory, Non-free--parameter, Dissipative) scheme which is a kind of the TVD (Total Variation Diminishing) schemes is adopted. The computation grid is generated by an algebraic method. To save computation time, the grid is rigidly attached to the airfoil. The dynamic stall process is well simulated on NACA 0012 airfoil oscillating in pitch at a high incidence angle in a transonic flow. The pressure distributions and pressure contours at different moment are given to show the movement of shock wave and the change of pressure distributions.

Guo, G.L.; Yang, Y.N.; Ye, Z.Y. [Northwestern Polytechnical Univ., Xian (China)

1994-12-31

365

3D FEM Simulation of the Flow Forming Process Using Lagrangian and ALE Methods

The process of flow forming is numerically modeled using finite element codes based on the Forge2005® software. Two numerical approaches are considered. The first one uses an updated Lagrangian formulation. The problem is solved with help of a self-contact management algorithm. The second approach consists in using an ALE formulation that permits to optimize meshing with an adaptive method based on the Zienkiewicz-Zhu error estimation. The ALE method is well adapted to incremental forming processes such as flow forming and allows dealing with difficulties generated by the contact between the work piece and tools. Both formulations are coupled with complex tool kinematics. The Lagrangian formulation gives realistic results. The ALE formulation is promising with regard to computational time, and simulations on simple configurations show fairly good agreements with Lagrangian results.

Houillon, Marie; Massoni, Elisabeth; Ramel, Eric; Logé, Roland

2007-05-01

366

Goal sketching with activity diagrams

Digital Repository Infrastructure Vision for European Research (DRIVER)

Goal orientation is acknowledged as an important paradigm in requirements engineering. The structure of a goal-responsibility model provides opportunities for appraising the intention of a development. Creating a suitable model under agile constraints (time, incompleteness and catching up after an initial burst of creativity) can be challenging. Here we propose a marriage of UML activity diagrams with goal sketching in order to facilitate the production of goal responsibility models under the...

Boness, Kenneth Duncan; Harrison, Rachel

2008-01-01

367

Hubble's diagram and cosmic expansion

Digital Repository Infrastructure Vision for European Research (DRIVER)

Edwin Hubble's classic article on the expanding universe appeared in PNAS in 1929 [Hubble, E. P. (1929) Proc. Natl. Acad. Sci. USA 15, 168–173]. The chief result, that a galaxy's distance is proportional to its redshift, is so well known and so deeply embedded into the language of astronomy through the Hubble diagram, the Hubble constant, Hubble's Law, and the Hubble time, that the article itself is rarely referenced. Even though Hubble's distances have a large systematic error, Hubble's ve...

Kirshner, Robert P.

2004-01-01

368

Critical point analysis of phase envelope diagram

Phase diagram or phase envelope is a relation between temperature and pressure that shows the condition of equilibria between the different phases of chemical compounds, mixture of compounds, and solutions. Phase diagram is an important issue in chemical thermodynamics and hydrocarbon reservoir. It is very useful for process simulation, hydrocarbon reactor design, and petroleum engineering studies. It is constructed from the bubble line, dew line, and critical point. Bubble line and dew line are composed of bubble points and dew points, respectively. Bubble point is the first point at which the gas is formed when a liquid is heated. Meanwhile, dew point is the first point where the liquid is formed when the gas is cooled. Critical point is the point where all of the properties of gases and liquids are equal, such as temperature, pressure, amount of substance, and others. Critical point is very useful in fuel processing and dissolution of certain chemicals. Here in this paper, we will show the critical point analytically. Then, it will be compared with numerical calculations of Peng-Robinson equation by using Newton-Raphson method. As case studies, several hydrocarbon mixtures are simulated using by Matlab.

Soetikno, Darmadi; Kusdiantara, Rudy; Puspita, Dila; Sidarto, Kuntjoro A.; Siagian, Ucok W. R.; Soewono, Edy; Gunawan, Agus Y.

2014-03-01

369

Euler graph transformations for euler diagram layout

Digital Repository Infrastructure Vision for European Research (DRIVER)

Euler diagrams are frequently used for visualizing information about collections of objects and form an important component of various visual languages. Properties possessed by Euler diagrams correlate with their usability, such as whether the diagram has only simple curves or possesses concurrency. Sometimes, every diagram that represents some given information possesses some undesirable properties, and reducing the number of violations of undesirable properties is beneficial. In this paper ...

2010-01-01

370

Acceptance diagram analysis of the ion implanter

International Nuclear Information System (INIS)

The acceptance diagrams of the components in beam optics system are transformed to a certain point to form the acceptance diagram of the whole system. The task of beam optics calculation is to match the beam emittance diagram with the acceptance diagram of the system. The beam transportation efficiency can then be estimated. The ion implanter of LC-2B type is used as an example to illustrate the application of this technique

1990-01-01

371

Power Network Voronoi Diagram and Dynamic Construction

Digital Repository Infrastructure Vision for European Research (DRIVER)

Objective Voronoi diagrams are important in many fields in a series of sciences. Network Voronoi diagrams are useful to investigate dominance regions in a grid street system or a radial-circular street system. However, all generators may have different effect. To deal with a network Voronoi diagram with varied functions of generators, it must be worth formulating a power network Voronoi diagram. Method Adding weight value on generators, which is used to indicate factors related to are difficu...

Yili Tan; Ye Zhao; Yourong Wang

2012-01-01

372

Selection of the economic objective function for the optimization of process flow sheets

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper highlights the problem of selecting the most suitable economic optimization criteria for mathematical programming approaches to the synthesis, design, and optimization of chemical process flow sheets or their subsystems. Minimization of costs and maximization of profit are the most frequently used economic criteria in technical papers. However, there are manyother financial measures which can lead to different optimal solutions if applied in the objective function. This paper descr...

Novak-pintaric?, Zorka; Kravanja, Zdravko

2012-01-01

373

Simulation of two-phase flow processes in heterogeneous porous media with adaptive methods

Digital Repository Infrastructure Vision for European Research (DRIVER)

In recent years the demand for numerical simulations which help to support the work of engineers has constantly gained weight. In the same way the computational power advances, the complexity of the problems and demands posed to the numerical simulation tools increases, too. This thesis expands the simulation tool MUFTE-UG for two-phase flow processes in porous media with adaptive methods The approaches presented here can be divided into two parts: On the one hand, a space adaptive method is ...

Paul, Maren

2003-01-01

374

A realization of an automated data flow for data collecting, processing, storing and retrieving

International Nuclear Information System (INIS)

GEONET is a database system developed at the Stanford Linear Accelerator Center for the alignment of the Stanford Linear Collider. It features an automated data flow, ranging from data collection using HP110 handheld computers to processing, storing and retrieving data and finally to adjusted coordinates. This paper gives a brief introduction to the SLC project and the applied survey methods. It emphasizes the hardware and software implementation of GEONET using a network of IBM PC/XT's. 14 refs., 4 figs

1987-10-04

375

Directory of Open Access Journals (Sweden)

Full Text Available Flying generates predictably different patterns of optic flow compared with other locomotor states. A sensorimotor system tuned to rapid responses and a high bandwidth of optic flow would help the animal to avoid wasting energy through imprecise motor action. However, neural processing that covers a higher input bandwidth itself comes at higher energetic costs which would be a poor investment when the animal was not flying. How does the blowfly adjust the dynamic range of its optic flow-processing neurons to the locomotor state? Octopamine (OA is a biogenic amine central to the initiation and maintenance of flight in insects. We used an OA agonist chlordimeform (CDM to simulate the widespread OA release during flight and recorded the effects on the temporal frequency coding of the H2 cell. This cell is a visual interneuron known to be involved in flight stabilization reflexes. The application of CDM resulted in i an increase in the cell's spontaneous activity, expanding the inhibitory signalling range ii an initial response gain to moving gratings (20 – 60 ms post-stimulus that depended on the temporal frequency of the grating and iii a reduction in the rate and magnitude of motion adaptation that was also temporal frequency-dependent. To our knowledge, this is the first demonstration that the application of a neuromodulator can induce velocity-dependent alterations in the gain of a wide-field optic flow-processing neuron. The observed changes in the cell’s response properties resulted in a 33% increase of the cell’s information rate when encoding random changes in temporal frequency of the stimulus. The increased signalling range and more rapid, longer lasting responses employed more spikes to encode each bit, and so consumed a greater amount of energy. It appears that for the fly investing more energy in sensory processing during flight is more efficient than wasting energy on under-performing motor control.

KitD.Longden

2010-11-01

376

Investigating preferential flow processes in soils using anisotropy in electrical resistivity

Macropores occupy a small volume fraction of the pore space in the vadose zone. Water and solutes can quickly bypass the vadose zone through these macropores in a process known as macropore preferential flow. In the last few decades, many efforts were made to improve understanding the macropore preferential flow processes because of their importance in transporting agrochemicals and contaminants to the groundwater. Unfortunately, very few measurement methods provide insights into these preferential flow processes. In this context, the objective of this study is to evaluate whether anisotropy in electrical resistivity can be used to identify the existence of flow in macropores and perhaps even to characterize the exchange between macropores and bulk soil. In a first step, infiltration into a soil column with an artificial macropore was simulated using the HYDRUS software package that solves the pseudo three-dimensional axisymmetric Richards equation. The simulated temporal development of the resistivity anisotropy was obtained by solving the Poisson equation in MATLAB after converting the simulated water content distributions to electrical resistivity distributions. At the beginning of the simulation, a small anisotropy ratio was simulated because of the presence of the empty ('deactivated') macropore in the moist matrix. As soon as the infiltration process started, macropore flow occurred and both the horizontal and vertical resistivity decreased strongly. However, the vertical and horizontal resistivity reacted differently because of the presence of the conductive ('activated') macropore, which led to anisotropy in the resistivity. As soon as infiltration into the macropore stopped, water re-distributed from the macropore to the matrix domain and contrasts in electrical resistivity decreased within the column. To verify the simulation results in the laboratory, we measured the temporal dynamics of the anisotropy in resistivity during water infiltration into a soil column of 9 cm diameter and 40 cm length with an artificial macropore of 2 cm diameter in the center of the column. The first experimental results confirmed that the anisotropy in electrical resistivity can indeed be used to identify and perhaps even quantify macropore flow.

Al-Hazaimay, S.; Huisman, J. A.; Zimmermann, E.; Kemna, A.; Vereecken, H.

2012-12-01

377

Process Modelling of Gas Permeation Plants.

A review about the different models of gas permeation is given together with the mathematical handling. A new work diagram for cross flow permeation is evaluated. At last an example of a two-stage process is discussed. With 8 figs.. (ERA citation 13:00918...

K. Hattenbach

1987-01-01

378

Identification and Check of Inconsistencies between UML Diagrams

Directory of Open Access Journals (Sweden)

Full Text Available Relationships between Unified Modeling Language (UML diagrams are complex. The complexity leads to inconsistencies between UML diagrams easily. This paper focus on how to identify and check inconsistencies between UML diagrams. 13 consistency rules are given to identify inconsistencies between the most frequent 6 types of UML diagrams in the domain of information systems analysis and design. These diagrams are as follows: Use Case Diagrams, Class Diagrams, Activity Diagrams, State Machine Diagrams, Sequence Diagrams and Communication Diagrams. 4 methods are given to check inconsistencies between UML diagrams as follows: manual check, compulsory restriction, automatic maintenance, dynamic check. These rules and methods are helpful for developers to model information systems.

Xianhong Liu

2013-03-01

379

Optimization of process of the cadmium zone refining in hydrogen flow

International Nuclear Information System (INIS)

The values of technological parameters of zone refining, minimizing the process duration under preset restrictions for pure cadmium extraction percentage and degree of its refining, are determined. Under conditions of cadmium zone refining the most suitable way to search for optimal process parameters is to follow the successive stages: synthesis of necessary adequate statistical models, statement of the corresponding optimization problem on their basis and taking into account concrete technological restrictions, numerical problem solution on computer. The refined cadmium extraction percentage and impurity content in the final ingot part, determined according to total content of copper, lead, indium and gallium impurities, are considered. The obtained optimal conditions for cadmium zone refining in a hydrogen flow differs from the previously used one by less process time, that has enabled to reduce labour intensity of the process and power consumption

1987-01-01

380

Nash Bargaining on Maximum Flow Time Scheduling with Changeable Processing Time?

Directory of Open Access Journals (Sweden)

Full Text Available In the real world, there often exists the situation where one person is not able to undertake all the jobs alone in a large project. In this paper, we consider the situation where two persons cooperate in the performance of a project. We discuss the (two?person Nash Bargaining problem, where job processing time is a linear function of its start time, each person offers a single machine to process jobs, and his processing cost is defined as his minimized maximum flow time. By proposing a proper division of those jobs, we use the two corresponding subset of jobs, assigned to the two persons respectively, to yield a reasonable cooperative (processing profit allocation scheme acceptable to them.?

TANG Guo?chun

2012-07-01

381

Light-Element Reaction flow and the Conditions for r-Process Nucleosynthesis

We deduce new constraints on the entropy per baryon ($s/k$), dynamical timescale ($\\tau_{dyn}$), and electron fraction ($Y_{e}$) consistent with heavy element nucleosynthesis in the r-process. We show that the previously neglected reaction flow through the reaction sequence \\atg (n,$\\gamma$)\\Li significantly enhances the production of seed nuclei. We analyze the r-process nucleosynthesis in the context of a schematic exponential wind model. We show that fewer neutrons per seed nucleus implies that the entropy per baryon required for successful r-process nucleosynthesis must be more than a factor of two higher than previous estimates. This places new constraints on dynamical models for the r-process.

Sasaqui, T; Mathews, G J

2005-01-01

382

Directory of Open Access Journals (Sweden)

Full Text Available A non-identifier-based adaptive PI controller is designed using a gradient approach to improve the performance of a control system when device aging and environmental factors degrade the efficiency of the process. The design approach is based on the model reference adaptive control technique. The controller drives the difference (error between the process response and desired model output to zero asymptotically at a rate constrained by the desired characteristics of the model. The tuning rules are designed and justified for a non-linear process with dominant dynamics of second order. The advantage of this method for tracking and regulation compared to adaptive MIT control was validated in real time by conducting experiments on a laboratory air flow control system using the dSPACE interface in the SIMULINK software. The experimental results show that the process with adaptive PI controller has better dynamic performance and robustness than that with traditional adaptive MIT controller.

Sivakumar Dakshinamurthy

2010-07-01

383

Fractal-Markovian scaling of turbulent bursting process in open channel flow

International Nuclear Information System (INIS)

The turbulent coherent structure of flow in open channel is a chaotic and stochastic process in nature. The coherence structure of the flow or bursting process consists of a series of eddies with a variety of different length scales and it is very important for the entrainment of sediment particles from the bed. In this study, a fractal-Markovian process is applied to the measured turbulent data in open channel. The turbulent data was measured in an experimental flume using three-dimensional acoustic Doppler velocity meter (ADV). A fractal interpolation function (FIF) algorithm was used to simulate more than 500,000 time series data of measured instantaneous velocity fluctuations and Reynolds shear stress. The fractal interpolation functions (FIF) enables to simulate and construct time series of u', v', and u'v' for any particular movement and state in the Markov process. The fractal dimension of the bursting events is calculated for 16 particular movements with the transition probability of the events based on 1st order Markov process. It was found that the average fractal dimensions of the streamwise flow velocity (u') are; 1.73, 1.74, 1.71 and 1.74 with the transition probability of 60.82%, 63.77%, 59.23% and 62.09% for the 1-1, 2-2, 3-3 and 4-4 movements, respectively. It was also found that the fractal dimensions of Reynold stress u'v' for quadrants 1, 2, 3 and 4 are 1.623, 1.623, 1.625 and 1.618, respectively

2005-07-01

384

An Improved Experimental Method for Simulating Erosion Processes by Concentrated Channel Flow

Rill erosion is an important process that occurs on hill slopes, including sloped farmland. Laboratory simulations have been vital to understanding rill erosion. Previous experiments obtained sediment yields using rills of various lengths to get the sedimentation process, which disrupted the continuity of the rill erosion process and was time-consuming. In this study, an improved experimental method was used to measure the rill erosion processes by concentrated channel flow. By using this method, a laboratory platform, 12 m long and 3 m wide, was used to construct rills of 0.1 m wide and 12 m long for experiments under five slope gradients (5, 10, 15, 20, and 25 degrees) and three flow rates (2, 4, and 8 L min?1). Sediment laden water was simultaneously sampled along the rill at locations 0.5 m, 1 m, 2 m, 3 m, 4 m, 5 m, 6 m, 7 m, 8 m, 10 m, and 12 m from the water inlet to determine the sediment concentration distribution. The rill erosion process measured by the method used in this study and that by previous experimental methods are approximately the same. The experimental data indicated that sediment concentrations increase with slope gradient and flow rate, which highlights the hydraulic impact on rill erosion. Sediment concentration increased rapidly at the initial section of the rill, and the rate of increase in sediment concentration reduced with the rill length. Overall, both experimental methods are feasible and applicable. However, the method proposed in this study is more efficient and easier to operate. This improved method will be useful in related research.

Chen, Xiao-Yan; Zhao, Yu; Mo, Bin; Mi, Hong-Xing

2014-01-01

385

International Nuclear Information System (INIS)

Amongst chemical decontamination techniques, the foam cleaning process has the advantage of reducing the amount of liquid used, thus limiting the quantity of the chemical reagents and the secondary waste volume. In order to improve this process, it is essential to understand the behaviour of the foam in the vicinity of the contaminated surface. Two methods of study have been initiated. Firstly, the characterization of the liquid film formed on the wall, and secondly, the characterization of the foam bed. Furthermore, our goal is to set up a drainage model which enables a choice of process parameters. Flush-mounted conductance probes have been developed in order to determine the thickness of the liquid film at the surface and the foam liquid fraction. The influence of the foam on the film structure and the interpretation of the thickness measured is discussed. The process studied consists of filling the facility with foam and letting the foam drain once the facility is full. It was demonstrated that the liquid film thickness varies between a few microns and 50 ?m and that the value depends on position and time. Furthermore, a strong correlation links the film thickness and the foam liquid fraction. A drift-flux model has been built to describe the drainage of the upstream flow or static foam. The model is solved by using the method of characteristics. Analytical solutions are obtained and the liquid fraction evolution can easily be represented on a single diagram. The parameters of the void-drift closure law have been deducted from the experiments. The comparison to experimental data has shown that the model is well adapted. The laboratory therefore has experimental and theoretical equipment to study any foam. Finally, the model is applied to realistic decontamination configurations in order to present how determine the parameters of the process. (author)

2002-01-01

386

Phase Diagrams in Chemical Engineering: Application to Distillation and Solvent Extraction

Digital Repository Infrastructure Vision for European Research (DRIVER)

A phase diagram in physical chemistry and chemical engineering is a graphical representation showing distinct phases which are in thermodynamic equilibrium. Since these equilibrium relationships are dependent on the pressure, temperature, and composition of the system, a phase diagram provides a graphical visualization of the effects of these system variables on the equilbrium behavior between the phases. Phase diagrams are essential in the understanding and development of separation processe...

2012-01-01

387

Overland flow generation processes in sub-humid Mediterranean forest stands

Forest soils in north and central Portugal have suffered and continue to suffer major structural changes as a result of forest management techniques, such as clear-felling and as a result of wildfire and rip-ploughing, which is carried out to prepare the ground for planting tree seedlings. In soils that have undergone these changes, the characteristics tend to be different for coniferous plantations, where the root system tends to die when the trees are cut following fire and subsequently may be consumed by fire to form a macropore network, and other types of tree plantations where the root system remains alive and allows regrowth from the sawn tree stumps. Overland flow thresholds decrease sharply as a result of rip-ploughing and forest fires and increase following clear-felling. The time taken for trees to reach maturity after wildfire differs markedly betwen the two main species (Pinus pinaster Aiton and Eucalyptus globulus Labill.) stands. In this paper, overland flow is considered in relation to rainfall, throughfall and throughflow, both in terms of hydrology and hydrochemistry in an attempt to understand overland flow generation mechanisms for a variety of forest land uses (mature pine and eucalyptus, pine seedling regrowth and eucalyptus regrowth from tree stumps, eucalyptus plantations and burned pine). Overland flow generation processes change sharply, even within a single rainfall event, as reflected in the soil hydrological processes and the hydrochemical fingerprints. These effects result from the different contact times for water and soil, which cause differences in the absorption and exhudation processes for the two species

Ferreira, A. J. D.; Ferreira, C. S. S.; Coelho, C. O. A.; Walsh, R. P. D.; Shakesby, R. A.

2012-04-01

388

Applying Genetic Algorithm for Prioritization of Test Case Scenarios Derived from UML Diagrams

Directory of Open Access Journals (Sweden)

Full Text Available Software testing involves identifying the test cases which discover errors in the program. However, exhaustive testing of software is very time consuming. In this paper, a technique is proposed to prioritize test case scenarios by identifying the critical path clusters using genetic algorithm. The test case scenarios are derived from the UML activity diagram and state chart diagram. The testing efficiency is optimized by applying the genetic algorithm on the test data. The information flow metric is adopted in this work for calculating the information flow complexity associated with each node of the activity diagram and state chart diagram. If the software requirements change, the software needs to be modified and this requires re - testing of the software. Hence, to take care of requirements change, a stack based approach for assigning weights to the nodes of activity diagram and state chart diagram has also been proposed. In this paper, we have extended our previous work of generating test case scenarios from activity diagram by also considering the concurrent activities in nested activity diagram.

Sangeeta Sabharwal

2011-05-01

389

Directory of Open Access Journals (Sweden)

Full Text Available Based on the research and development about Web service, the business platform topology of ac-service flow is deepened from architecture-centric perspective. For Web service’s dynamic composition and self-adaptation meeting user requirement, architecture-centric merging among flows is put forward, in order to get this goal, optimizing previous flow granularities’ selection and composition. To satisfy flexible building and mapping of flows, the evolution algorithm E-DPSO based on discrete particle Swarm is designed. With dynamic character of service composition and the integrity of flow sequence, ac-service flow’s implementation strategy is given and finished demonstration. ac-service flow is viewed as the business organization clue, the platform framework structure of service implementation process is built for planning and decision-making.

Xiaona Xia

2012-07-01

390

Embedding theorem for spike trains and active processes in chaotic flows

This thesis contains two separate topics. The first topic concerns proof of a theorem that justifies the method of reconstruction of dynamics using inter-event time intervals. In particular, we prove that the function from an invariant set of a typical dynamical system into R d, defined by successive inter-event time intervals from integrate-and-fire dynamics, is prevalently a topological embedding. This allows topological information about a dynamical attractor to be inferred from spike trains. The second topic is the active processes of particles advected by chaotic flows. While previous studies focused on the active processes of massless point particles, or an ideal tracer, we discuss the particles with finite mass and size. Their equations of motion are inherently dissipative, due to the Stokes drag. The dynamics of the advected particles can be chaotic even with a flow field that is simply time-periodic. Similarly to the case of ideal tracers, whose dynamics is Hamiltonian, chemical or biological activity involving such particles advected by fluid flows can be analyzed using the theory of chaotic dynamics. We choose the cellular vortex flow field with periodically varying vorticity as an example, and analyze the dynamics of the reaction of autocatalytic type, A + B ? 2 B, and of coalescence type, B + B ? B. Another assumption that the previous studies on the active processes had, was that the reaction of all particles in the system occurs simultaneously. Here we investigate the effect of asynchronism of the autocatalytic reaction taking place in an open hydrodynamical flow, by assigning each particle in the system with a phase to differentiate the timing of their reactions, but not their periodicity. The chaotic saddle in the flow dynamics acts as a catalyst and enhances the reaction in the same fashion as in the case of synchronous reaction that was studied previously. However, we show that, in certain range of a parameter, the group of particles with a particular phase can be favored over the others, thus occupying a larger part of the available space, or eventually, leading to extinction of the unfavored phase.

Nishikawa, Takashi

2000-10-01

391

Energy Technology Data Exchange (ETDEWEB)

A three-dimensional transient computational fluid dynamics (CFD) model was developed to investigate the material flow and heat transfer during friction stir processing (FSP) in an AZ31B magnesium alloy. The material was assumed to be a non-Newtonian viscoplastic fluid, and the Zener-Hollomon parameter was used to describe the dependence of material viscosity on temperature and strain rate. The material constants used in the constitutive equation were determined experimentally from compression tests of the AZ31B Mg alloy under a wide range of strain rates and temperatures. A dynamic mesh method, combining both Lagrangian and Eulerian formulations, was used to capture the material flow induced by the movement of the threaded tool pin. Massless inert particles were embedded in the simulation domain to track the detailed history of material flow. The actual FSP was also carried out on a wrought Mg plate where temperature profiles were recorded by embedding thermocouples. The predicted transient temperature history was found to be consistent with that measured during FSP. Finally, the influence of the thread on the simulated results of thermal history and material flow was studied by comparing two models: one with threaded pin and the other with smooth pin surface.

Yu, Zhenzhen [ORNL; Zhang, Wei [ORNL; Choo, Hahn [ORNL; Feng, Zhili [ORNL

2012-01-01

392

Process Based Prediction of Flow Distribution at Ungauged Himalayan Catchments using Satellite Data

In-line hydropower (IHP), whereby micro hydropower turbines are integrated in gravity fed rural water supply systems, is a promising yet underutilized infrastructure synergy in rural mountainous areas of developing countries. In Nepal, although institutional and economic considerations are critical, the available local hydropower potential - in particular the flow availability to drive turbines - is the key feasibility criterion. Yet flow projections in remote areas remain a significant challenge largely due to difficult access and data scarcity. We recently showed that satellite data could be successfully adjusted to generate parameters describing the frequency and intensity of daily rainfall. The flow predictions needed for hydropower siting relate primarily to a frequency domain description, specifically the fluw duration curves, which are closely controlled by these rainfall parameters. This project combines bias-corrected satellite rainfall parameters with remotely sensed stationary watershed data to predict the flow duration curves at ungauged Himalayan watersheds. In particular, we compare the performance of several approaches with different levels of process representation, applied to sparsely gauged, snow-fed and topographically complex catchments with highly seasonal rainfall.

Muller, M. F.; Thompson, S. E.

2013-12-01

393

Non-equilibrium reacting gas flows. Kinetic theory of transport and relaxation processes

Energy Technology Data Exchange (ETDEWEB)

In the present monograph, we develop the kinetic theory of transport phenomena and relaxation processes in the flows of reacting gas mixtures and discuss its applications to strongly non-equilibrium conditions. The main attention is focused on the influence of non-equilibrium kinetics on gas dynamics and transport properties. Closed systems of fluid dynamic equations are derived from the kinetic equations in different approaches. We consider the most accurate approach taking into account the state-to-state kinetics in a flow, as well as simplified multi-temperature and one-temperature models based on quasi-stationary distributions. Within these approaches, we propose the algorithms for the calculation of the transport coefficients and rate coefficients of chemical reactions and energy exchanges in non-equilibrium flows; the developed techniques are based on the fundamental kinetic theory principles. The theory is applied to the modeling of non-equilibrium flows behind strong shock waves, in the boundary layer, and in nozzles. The comparison of the results obtained within the frame of different approaches is presented, the advantages of the new state-to-state kinetic model are discussed, and the limits of validity for simplified models are established. The book can be interesting for scientists and graduate students working on physical gas dynamics, aerothermodynamics, heat and mass transfer, non-equilibrium physical-chemical kinetics, and kinetic theory of gases. (orig.)

Nagnibeda, Ekaterina; Kustova, Elena [St. Petersburg State Univ. (Russian Federation). Dept. of Mathematics and Mechanics

2009-07-01

394

Flow regimes of condensation processes in the emergency condenser test facility. Final report

International Nuclear Information System (INIS)

Within the framework of research project 15 NU 09485, 'Calculation and configuration of the passive emergency condenser of an innovative, natural-convection BWR (SWR600) using the ATHLET code', which is closely connected with research project 15 NU 9050, 'Emergency condenser for a medium-output BWR - experiments for performance assessment', measurements were carried out at the NOKO experimental facility for identification of flow regimes and condensation processes. The task was to measure the flow regimes in the NOKO tube by means of needle-type conductuivity probes. The probes were placed into a single heat transfer tube (NOKO single tube) specifically installed for this purpose at the NOKO experimental facility. Several probes were inserted in each of two selected flow sections so that the phase distribution could be measured dynamically during liquid level lowering, i.e. at the probes positioned in downward level direction. The shape of the phase boundaries was reconstructed from the measured data. This arrangement of the probes detects and yields measured data of the various flow regimes occurring. (orig./DG)

1997-01-01

395

Characteristics of two-phase condensing flow by visualization using computed image processing

International Nuclear Information System (INIS)

The mechanics of the condensing behavior of vapor bubbles in a subcooled bulk flow is complicated and influenced by both heat and mass transfer. To examine the characteristics of such thermal-nonequilibrium two-phase flow, experimental and analytical researches have been made. In the experiment, the movement of each vapor bubble in a flowing channel was recorded on video tapes and analyzed by an image processing system. As result, the distributions of void fraction along the test section were obtained. In the analysis, a simple analytical model was introduced to predict the distributions of void fraction and liquid subcooling temperature. By considering the rate of vapor condensation along the flow direction, the differntial equation of energy balance between two phases was obtained. Integration of this equation yielded the void fraction and bulk liquid subcooling at any position. The condensation rate was estimated as a function of the local liquid subcooling, interfacial area and mass velocity. Finally, a close fit between calculated results and experimental data was obtained. (orig.)

1993-06-01

396

Fluid flow and heat transfer in an optical fiber coating process

Energy Technology Data Exchange (ETDEWEB)

The optical fiber coating process, using a die and applicator system, was numerically simulated. The coupled partial differential equations, governing the fluid flow and heat transfer, were solved on a transformed, non-uniform, staggered grid. A finite volume method, with conjugate heat transfer, boundary-fitted grid, and variable transport properties, was employed. The pressure was calculated using a SIMPLE-based algorithm. An isothermal case was first modeled, where the effect of the Reynolds number (Re) was studied for different geometries. Different coating fluids were considered. A conjugate boundary condition was employed at the fiber-fluid interface for the non-isothermal flow. A free surface boundary condition was used at the fiber entry into the coating fluid. The meniscus was prescribed on the basis of prior experimental work. Regardless of fiber speed, a circulating flow was observed in the applicator. High shear rates at the dynamic contact point suggest that air can be entrained with a fast moving fiber. It was also found that pressures at the coating fluid inlet did not play a major role, for typical fiber speeds, whereas the thermal conditions that affect the properties of the fluid, such as viscosity, made a significant impact on both the flow and the thermal field. This work could be used to determine the parameters that are critical for improving the quality of the coating, particularly its uniformity, and the production rate. (author)

Yoo, Sang-Yeoun; Jaluria, Yogesh [Department of Mechanical and Aerospace Engineering, Rutgers, The State University of New Jersey, 98 Brett Road, Piscataway, NJ 08854-8058 (United States)

2007-03-15

397

Temporal and spatial distribution of tracer elements and subsurface flow processes were investigated to study relationship between storm hydrograph components and behavior of subsurface water in a headwater catchment of Toyota Hill, Aichi prefecture, central Japan. The catchment has an area of 0.857 ha with an altitude of 60 to 100 m, and is underlain by granite. The soil depth revealed by sounding test ranges from 0.5 to 4.0 m. Rain, stream, soil and ground waters were sampled once in a week, and the stream water was sampled at 5 to 60 minute intervals during rainstorms. The pressure head of subsurface water was monitored using tensiometers and piezometers nests, and the stream flow was monitored using V-notch weir. The stable isotopic ratios of deuterium and oxygen 18 and inorganic ion concentrations were determined on all water samples. The oxygen 18 isotopic ratio in stream water decreased with rainfall during the rainstorms. The ratio of event water component to the total runoff water at the peak discharge ranged from 16 to 92 %, and the event water ratio correlated with the peak discharge rate and rainfall intensity. The tesiometric data showed that the shallow subsurface water with low isotopic ratios at the lower slope discharged directly to the stream during the heavy rainstorms. The shallow subsurface flow at the lower slope and overland flow on the raiparian zone contributed much to the stream water chemistry during heavy rainstorms.

Tsujimura, M.; Asai, K.; Takei, R.

2001-05-01

398

The flow in a confined container induced by an ultrasonic horn is measured by Particle Image Velocimetry (PIV). This flow is caused by acoustic streaming and highly influenced by the presence of cavitation. The jet-like experimentally observed flow is compared with the available theoretical solution for a turbulent free round jet. The similarity between both flows enables a simplified numerical model to be made, whilst the phenomenon is very difficult to simulate otherwise. The numerical model requires only two parameters, i.e. the flow momentum and turbulent kinetic energy at the position of the horn tip. The simulated flow is used as a basis for the calculation of the time required for the entire liquid volume to pass through the active cavitation region. PMID:22658635

Schenker, M C; Pourquié, M J B M; Eskin, D G; Boersma, B J

2013-01-01

399

Modeling of the flow stress for AISI H13 Tool Steel during Hard Machining Processes

International Nuclear Information System (INIS)

In general, the flow stress models used in computer simulation of machining processes are a function of effective strain, effective strain rate and temperature developed during the cutting process. However, these models do not adequately describe the material behavior in hard machining, where a range of material hardness between 45 and 60 HRC are used. Thus, depending on the specific material hardness different material models must be used in modeling the cutting process. This paper describes the development of a hardness-based flow stress and fracture models for the AISI H13 tool steel, which can be applied for range of material hardness mentioned above. These models were implemented in a non-isothermal viscoplastic numerical model to simulate the machining process for AISI H13 with various hardness values and applying different cutting regime parameters. Predicted results are validated by comparing them with experimental results found in the literature. They are found to predict reasonably well the cutting forces as well as the change in chip morphology from continuous to segmented chip as the material hardness change

2007-04-07

400

Development of an entrained flow gasifier model for process optimization study

Energy Technology Data Exchange (ETDEWEB)

Coal gasification is a versatile process to convert a solid fuel in syngas, which can be further converted and separated in hydrogen, which is a valuable and environmentally acceptable energy carrier. Different technologies (fixed beds, fluidized beds, entrained flow reactors) are used, operating under different conditions of temperature, pressure, and residence time. Process studies should be performed for defining the best plant configurations and operating conditions. Although 'gasification models' can be found in the literature simulating equilibrium reactors, a more detailed approach is required for process analysis and optimization procedures. In this work, a gasifier model is developed by using AspenPlus as a tool to be implemented in a comprehensive process model for the production of hydrogen via coal gasification. It is developed as a multizonal model by interconnecting each step of gasification (preheating, devolatilization, combustion, gasification, quench) according to the reactor configuration, that is in entrained flow reactor. The model removes the hypothesis of equilibrium by introducing the kinetics of all steps and solves the heat balance by relating the gasification temperature to the operating conditions. The model allows to predict the syngas composition as well as quantity the heat recovery (for calculating the plant efficiency), 'byproducts', and residual char. Finally, in view of future works, the development of a 'gasifier model' instead of a 'gasification model' will allow different reactor configurations to be compared.

Biagini, E.; Bardi, A.; Pannocchia, G.; Tognotti, L. [Consorzio Pisa Ric, Pisa (Italy). Div Energia Ambiente

2009-10-15

401

Process Development for Hydrothermal Liquefaction of Algae Feedstocks in a Continuous-Flow Reactor

Energy Technology Data Exchange (ETDEWEB)

Wet algae slurries can be converted into an upgradeable biocrude by hydrothermal liquefaction (HTL). High levels of carbon conversion to gravity-separable biocrude product were accomplished at relatively low temperature (350 ?C) in a continuous-flow, pressurized (sub-critical liquid water) environment (20 MPa). As opposed to earlier work in batch reactors reported by others, direct oil recovery was achieved without the use of a solvent and biomass trace components were removed by processing steps so that they did not cause process difficulties. High conversions were obtained even with high slurry concentrations of up to 35 wt% of dry solids. Catalytic hydrotreating was effectively applied for hydrodeoxygenation, hydrodenitrogenation, and hydrodesulfurization of the biocrude to form liquid hydrocarbon fuel. Catalytic hydrothermal gasification was effectively applied for HTL byproduct water cleanup and fuel gas production from water soluble organics, allowing the water to be considered for recycle of nutrients to the algae growth ponds. As a result, high conversion of algae to liquid hydrocarbon and gas products was found with low levels of organic contamination in the byproduct water. All three process steps were accomplished in bench-scale, continuous-flow reactor systems such that design data for process scale-up was generated.

Elliott, Douglas C.; Hart, Todd R.; Schmidt, Andrew J.; Neuenschwander, Gary G.; Rotness, Leslie J.; Olarte, Mariefel V.; Zacher, Alan H.; Albrecht, Karl O.; Hallen, Richard T.; Holladay, Johnathan E.

2013-10-01

402

Liftings of diagrams of semilattices by diagrams of dimension groups

We investigate categorical and amalgamation properties of the functor Idc assigning to every partially ordered abelian group G its semilattice of compact ideals Idc G. Our main result is the following. Theorem 1. Every diagram of finite Boolean semilattices indexed by a finite dismantlable partially ordered set can be lifted, with respect to the Idc functor, by a diagram of pseudo-simplicial vector spaces. Pseudo-simplicial vector spaces are a special kind of finite-dimensional partially ordered vector spaces (over the rationals) with interpolation. The methods introduced make it also possible to prove the following ring-theoretical result. Theorem 2. For any countable distributive join-semilattices S and T and any field K, any (v,0)-homomorphism $f: S\\to T$ can be lifted, with respect to the Idc functor on rings, by a homomorphism $f: A\\to B$ of K-algebras, for countably dimensional locally matricial algebras A and B over K. We also state a lattice-theoretical analogue of Theorem 2 (with respect to the Conc ...

Tuma, J; Tuma, Jiri; Wehrung, Friedrich

2005-01-01

403

Energy Technology Data Exchange (ETDEWEB)

Silver-copper alloys with a composition entering a liquid-solid domain of the phase diagram are condensed on a titled molybdenum substrate, regulated in temperature. Droplets containing nodular crystals, for the most part in contact with the substrate, condense and coalesce to form a film. The film forms more quickly in the solid-liquid than in the fully liquid areas. It indicates that the crystals constitute pinning points for the droplets. A correlation between the condensate thickness and the local solid fraction at the transition between film and droplets is given. In the film areas, the gravity-dependent effect plays an important role. In case of the silver-rich condensate, the solid-phase is expected to be more easily driven by the liquid flow. (authors)

Leroux, S.; Gueneau, Ch.; Le Ny, J. [CEA/Saclay, Dept. de Protection de l' environnement (DPE), 91 - Gif-sur-Yvette (France); Camel, D.; Drevet, B.; Granier, J. [CEA/Grenoble, Dept. d' Etudes des Materiaux (DEM), 38 (France)

1999-07-01

404

Macroscopic fundamental diagrams for Stockholm using FCD data

Digital Repository Infrastructure Vision for European Research (DRIVER)

Macroscopic fundamental diagrams (MFD) reveal the relations among flow, speed and density in a large geographic region. After literature review on macroscopic analysis, the similar methodology is applied in this thesis. The purpose of the thesis is to find the evidence that is able to prove MFD existing in Stockholm urban region. Both floating car data (FCD) based on global positioning system (GPS) data from taxis travelling in Stockholm region and traffic data from fixed detectors data sourc...

Feng, Gao

2011-01-01

405

Directory of Open Access Journals (Sweden)

Full Text Available This paper explores the use of flow length and travel time as a pre-processing step for incorporating spatial precipitation information into Artificial Neural Network (ANN models used for river flow forecasting. Spatially distributed precipitation is commonly required when modelling large basins, and it is usually incorporated in distributed physically-based hydrological modelling approaches. However, these modelling approaches are recognised to be quite complex and expensive, especially due to the data collection of multiple inputs and parameters, which vary in space and time. On the other hand, ANN models for flow forecasting are frequently developed only with precipitation and discharge as inputs, usually without taking into consideration the spatial variability of precipitation. Full inclusion of spatially distributed inputs into ANN models still leads to a complex computational process that may not give acceptable results. Therefore, here we present an analysis of the flow length and travel time as a basis for pre-processing remotely sensed (satellite rainfall data. This pre-processed rainfall is used together with local stream flow measurements of previous days as input to ANN models. The case study for this modelling approach is the Ganges river basin. A comparative analysis of multiple ANN models with different hydrological pre-processing is presented. The ANN showed its ability to forecast discharges 3-days ahead with an acceptable accuracy. Within this forecast horizon, the influence of the pre-processed rainfall is marginal, because of dominant influence of strongly auto-correlated discharge inputs. For forecast horizons of 7 to 10 days, the influence of the pre-processed rainfall is noticeable, although the overall model performance deteriorates. The incorporation of remote sensing data of spatially distributed precipitation information as pre-processing step showed to be a promising alternative for the setting-up of ANN models for river flow forecasting.

M. K. Akhtar

2009-09-01

406

Directory of Open Access Journals (Sweden)

Full Text Available This paper explores the use of flow length and travel time as a pre-processing step for incorporating spatial precipitation information into Artificial Neural Network (ANN models used for river flow forecasting. Spatially distributed precipitation is commonly required when modelling large basins, and it is usually incorporated in distributed physically-based hydrological modelling approaches. However, these modelling approaches are recognised to be quite complex and expensive, especially due to the data collection of multiple inputs and parameters, which vary in space and time. On the other hand, ANN models for flow forecasting are frequently developed only with precipitation and discharge as inputs, usually without taking into consideration the spatial variability of precipitation. Full inclusion of spatially distributed inputs into ANN models still leads to a complex computational process that may not give acceptable results. Therefore, here we present an analysis of the flow length and travel time as a basis for pre-processing remotely sensed (satellite rainfall data. This pre-processed rainfall is used together with local stream flow measurements of previous days as input to ANN models. The case study for this modelling approach is the Ganges river basin. A comparative analysis of multiple ANN models with different hydrological pre-processing is presented. The ANN showed its ability to forecast discharges 3-days ahead with an acceptable accuracy. Within this forecast horizon, the influence of the pre-processed rainfall is marginal, because of dominant influence of strongly auto-correlated discharge inputs. For forecast horizons of 7 to 10 days, the influence of the pre-processed rainfall is noticeable, although the overall model performance deteriorates. The incorporation of remote sensing data of spatially distributed precipitation information as pre-processing step showed to be a promising alternative for the setting-up of ANN models for river flow forecasting.

M. K. Akhtar

2009-04-01

407

This paper explores the use of flow length and travel time as a pre-processing step for incorporating spatial precipitation information into Artificial Neural Network (ANN) models used for river flow forecasting. Spatially distributed precipitation is commonly required when modelling large basins, and it is usually incorporated in distributed physically-based hydrological modelling approaches. However, these modelling approaches are recognised to be quite complex and expensive, especially due to the data collection of multiple inputs and parameters, which vary in space and time. On the other hand, ANN models for flow forecasting are frequently developed only with precipitation and discharge as inputs, usually without taking into consideration the spatial variability of precipitation. Full inclusion of spatially distributed inputs into ANN models still leads to a complex computational process that may not give acceptable results. Therefore, here we present an analysis of the flow length and travel time as a basis for pre-processing remotely sensed (satellite) rainfall data. This pre-processed rainfall is used together with local stream flow measurements of previous days as input to ANN models. The case study for this modelling approach is the Ganges river basin. A comparative analysis of multiple ANN models with different hydrological pre-processing is presented. The ANN showed its ability to forecast discharges 3-days ahead with an acceptable accuracy. Within this forecast horizon, the influence of the pre-processed rainfall is marginal, because of dominant influence of strongly auto-correlated discharge inputs. For forecast horizons of 7 to 10 days, the influence of the pre-processed rainfall is noticeable, although the overall model performance deteriorates. The incorporation of remote sensing data of spatially distributed precipitation information as pre-processing step showed to be a promising alternative for the setting-up of ANN models for river flow forecasting.

Akhtar, M. K.; Corzo, G. A.; van Andel, S. J.; Jonoski, A.

2009-09-01

408

Temporal evolution of the convective plasma flow during a reconnection process

International Nuclear Information System (INIS)

An extension of the nonlinear reconnection model of the Petschek type which suggests that the efficiency of the energy conversion from magnetic into kinetic energy of the plasma may be essentially enhanced by shock waves, is presented in order to describe the large-scale temporal evolution of the shocks in a reconnection configuration. At the shock waves fronts, currents flow and a nonzero normal magnetic field component exists. From the balance of the tangential stress across the switch-off shock waves, it is found that in the downstream or field reversal (FR) region the plasma moves approximately with Alfven speed. At a certain time the reconnection process in the diffusion region may stop and consequently, the FR-regions sever at the origin and flow in opposite directions. 13 references

1984-07-07

409

Phase Diagram of Janus Particles

We thoroughly investigate a simple model representative of the recently synthesized Janus particles, i.e., colloidal spherical particles whose surface is divided into two areas of different chemical composition. When the two surfaces are solvophilic and solvophobic, these particles constitute the simplest example of surfactants. The phase diagram includes a colloidal-poor (gas), colloidal-rich (liquid) demixing region, which is progressively suppressed by the insurgence of micelles, providing the first model in which micellization and phase separation are simultaneously observed. The coexistence curve is found to be negatively sloped in the temperature-pressure plane, suggesting that Janus particles can provide a colloidal system with anomalous thermodynamic behavior.

Sciortino, Francesco; Giacometti, Achille; Pastore, Giorgio

2009-12-01

410

Optical generation of Voronoi diagram.

We present results of experiments of diffraction by an amplitude screen, made of randomly distributed circular holes. By careful selection of the experimental parameters we obtain an intensity pattern strongly connected to the Voronoi diagram (VD) generated by the centers of the apertures. With the help of simulations we give a description of the observed phenomenon and elucidate the optimal parameters for its observation. Finally, we also suggest how it can be used for a fast, all-optical generation of VDs. PMID:18542580

Giavazzi, F; Cerbino, R; Mazzoni, S; Giglio, M; Vailati, A

2008-03-31

411

The Hubble diagram - a rediscussion

International Nuclear Information System (INIS)

A rederivation of the deceleration parameter q0 basing on new observational data (Gunn and Oke 1075) and using more conventional analysis with a particular attention to the Scott effect is reported. The resulting value of q0 obtained on the assumption of no evolution is q0 obtained on the assumption of no evolution is q0=0.54+-0.52 or about 0.5 larger than that reported by Gunn and Oke. The additional uncertainty sets of photometric observations may also introduce an appreciable error into resulting q0. At present the Hubble diagram analysis is evidently not yet sufficient for discrimination between the open and closed universes. (author)

1976-01-01

412

Simulation of drop deposition process in annular mist flow using three-dimensional particle method

International Nuclear Information System (INIS)

The three-dimensional moving particle semi-implicit (MPS) method is employed to simulate the deposition process of single droplet on the liquid film. The model accounts for the presence of inertial, gravitation, viscous and surface tension and is validated by comparison with experimental results. The parameters of liquid droplets and film are calculated by a one-dimensional mixture model in which correlations and methods on void fraction, entrainment fraction and droplet velocity and size distribution are employed. The simulation results are analyzed to study the effect of splash on the deposition and re-entrainment processes in annular-mist flow. It is found that splash plays an important role in the deposition and re-entrainment processes in high quality conditions of BWR

2005-07-01

413

International Nuclear Information System (INIS)

Highlights: ? We generate complex networks of dislocations in Cu nanopillars by atomistic method. ? Their evolution during compression is examined as a function of pillar diameter. ? Sub-75nm Cu pillars show same flow stress scaling than past compression experiments. ? A deformation mechanism map is developed for Cu crystals with different diameters. ? We elucidate the atomistic origin of size-dependent plasticity in Cu nanocrystals. - Abstract: The size dependence of strength observed in submicrometer face-centered-cubic (fcc) metallic crystals under uniform deformation depends on the interaction of pre-existing dislocations with surfaces. To date, however, the dislocation processes controlling flow stress scaling in fcc crystals less than 100 nm in size have remained an open question due to limited knowledge on microstructural evolution during deformation in such small volumes. Here, molecular dynamics computer simulations employing a technique of high-temperature annealing and quenching on porous crystals were used to generate complex dislocation microstructures in sub-75 nm Cu pillars with high initial dislocation densities of 1016 m-2, which made it possible to quantitatively examine their evolution during compression as a function of pillar diameter. These simulations reveal a transition from a state of dislocation exhaustion, where mobile dislocations are lost at the free surface and the dislocation density steadily decreases, to a regime of intermittent plastic flow between elastic loading and source-limited activation inside the pillars. It is shown that plastic flow stresses predicted during dislocation exhaustion regime exhibit little to no size dependence, while pronounced size effects are found during source-limited activation. Remarkably, the relationship between flow stress predicted at 5% strain and diameter is found to follow closely the power-law dependence reported in past experiments with larger Cu crystals and smaller densities. A deformation mechanism map, expressed in terms of diameter, is developed and used to elucidate the origin of size-dependent plasticity in nanoscale fcc crystals.

2011-05-01

414

Jerky flow behavior in a rapid solidification processed Al-Li alloy

Energy Technology Data Exchange (ETDEWEB)

The specific jerky flow behavior in a rapid solidification processed (RSP) Al-Li alloy has been studied systematically. The results show that stress-strain curves of the as-quenched RSP Al-Li alloy tensioned with a moderate strain rate (6.9 x 10{sup -4} s{sup -1}) show a typical plateau step feature with obvious physical yielding; the width of each plateau (except for the yield plateau) increases linearly with increasing total strain, while the height of the steps is almost the same for one specimen. Small and regular serrations usually begin to appear beyond the third plateau of transverse specimens, and the size of serrations in each plateau is equal, while that on the latter plateau is larger than that on the former. The specific jerky flow behavior of the RSP Al-Li alloy is suggested to be formed by initiation and propagation of a local deformation band during the tensile deformation process, which is caused by the combined effects of static and dynamic strain aging of Li and Mg atoms. The yield plateau is thought to be related to the static strain aging that occurred in the time period between aging treatment and tensile tests. Other plateaus are suggested to be caused by the first stage of dynamic strain aging (DSA I), while small and regular serrations on plateaus are attributed to the second stage of dynamic strain aging (DSA II). High Li content, high volume fraction of {delta}` phase and very fine grains in the RSP Al-Li alloy are major causes leading to the specific jerky flow behavior. The plateau step characteri