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1

TEP process flow diagram  

International Nuclear Information System (INIS)

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.

2

Fuel Retrieval System Process Flow Diagrams Mass Balance Calculations for K West Basin  

International Nuclear Information System (INIS)

This calculation justifies the numbers used for the material balance on the process flow diagrams for the KW Basin Fuel Retrieval Subproject. The purpose of these calculations is to develop the material balances that are documented in the Fuel Retrieval System (FRS) Process Flow Diagrams for future reference. The attached mass calculations were prepared in support of revising the fuel retrieval system process flow diagrams for the 105K West Basin. The calculations refer to diagram H-1-81164

3

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

CERN Document Server

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

Automation of process accountability flow diagrams at Los Alamos National Laboratory's Plutonium Facility  

International Nuclear Information System (INIS)

Many industrial processes (including reprocessing activities; nuclear fuel fabrication; and material storage, measurement and transfer) make use of process flow diagrams. These flows can be used for material accountancy and for data analysis. At Los Alamos National Laboratory (LANL), the Technical Area (TA)-55 Plutonium Facility is home to various research and development activities involving the use of special nuclear material (SNM). A facility conducting research and development (R and D) activities using SNM must satisfy material accountability guidelines. All processes involving SNM or tritium processing, at LANL, require a process accountability flow diagram (PAFD). At LANL a technique was developed to generate PAFDs that can be coupled to a relational database for use in material accountancy. These techniques could also be used for propagation of variance, measurement control, and inventory difference analysis. The PAFD is a graphical representation of the material flow during a specific process. PAFDs are currently stored as PowerPoint files. In the PowerPoint format, the data captured by the PAFD are not easily accessible. Converting the PAFDs to an accessible electronic format is desirable for several reasons. Any program will be able to access the data contained in the PAFD. For the PAFD data to be useful in applications such as an expert system for data checking, SNM accountability, inventory difference evaluation, measurement control, and other kinds of analysis, it is necessary to interface directly with the information contained within the PAFD. The PAFDs can be approved and distributed electronically, eliminating the paper copies of the PAFDs and ensuring that material handlers have the current PAFDs. Modifications to the PAFDs are often global. Storing the data in an accessible format would eliminate the need to manually update each of the PAFDs when a global change has occurred. The goal was to determine a software package that would store the PAFDs in an accessible format that could be interfaced by various programs. After evaluating several commercial relational database and graphing software packages, VISIO Enterprise was selected. LANL is in the process of completing conversion of the existing PAFDs into VISIO Enterprise. A number of the PAFDs have been converted to VISIO Enterprise, and the data from the drawings have been exported to an ACCESS database. After the conversion has taken place, the data contained in the PAFDs will be accessible for various programs. The data that was once stored in PowerPoint will now be available for tools, including expert analysis, propagation of a variance, SNM accountability, inventory difference analysis, measurement control, and other analysis tools that have yet to be identified. Converting from the PowerPoint format to a drawing stored as a relational database will improve the ability of plant personnel to interface with the PAFD

5

Business Process Flow Diagrams in Tissue Bank Informatics System Design, and Identification and Communication of Best Practices: The Pharmaceutical Industry Experience.  

Science.gov (United States)

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

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

7

Software Tool Integrating Data Flow Diagrams and Petri Nets  

Science.gov (United States)

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

8

Teaching Verbal Chains Using Flow Diagrams and Texts  

Science.gov (United States)

A discussion of the recent diagram and attention theory and research surprisingly suggests that a single flow diagram with instructive questions constitutes an effective learning medium in terms of verbal chaining. (Author)

Holliday, William G.

1976-01-01

9

The Delunification Process and Minimal Diagrams  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A link diagram is said to be lune-free if, when viewed as a 4-regular plane graph it does not have multiple edges between any pair of nodes. We prove that any colored link diagram is equivalent to a colored lune-free diagram with the same number of colors. Thus any colored link diagram with a minimum number of colors (known as a minimal diagram) is equivalent to a colored lune-free diagram with that same number of colors. We call the passage from a link diagram to an equival...

Jablan, Slavik; Kauffman, Louis; Lopes, Pedro

2014-01-01

10

Introducing the Circular Flow Diagram to Business Students  

Science.gov (United States)

The circular flow of income diagram is a simplified representation of the functioning of a free-market economic system. It illustrates how businesses interact with the other economic participants within the key macroeconomic markets that coordinate the flow of income through the national economy. Therefore, it can provide students of business with…

Daraban, Bogdan

2010-01-01

11

Concept and development of information flow diagram for literature survey  

International Nuclear Information System (INIS)

The Information Flow Diagram for Literature Survey (IFDLS) has been developed to manage information and procedure in the literature survey phase of the PTAs selection process. It is a tool utilizing information technology, which can organize, analyze, and evaluate information from literature survey and manage their process systematically. IFDLS is able to show the flow of information and data, and the history of information management processing. Information coverage and quality is not homogenous throughout the country and, in some areas, there may not even be sufficient data available to be able to reach a judgment on conformity with the site-specific evaluation factors (SSEF). Literature surveys could only be conducted on a volunteer area before it is nominated as a PIA. However, the absence of information on any factor mentioned will not constitute disqualification of the area. On the contrary, an attempt to compare these sites with analogous areas in Japan will be done to assemble sufficient data and consequently make a decision on whether to proceed further. The application of IFDLS to literature survey phase of the PIA selection process is being proposed. The concept, construction, application and evolution of IFDLS towards application phase on a trial basis are discussed. (authors)

12

Some bifurcation diagrams for Taylor vortex flows  

International Nuclear Information System (INIS)

The numerical continuation and bifurcation methods of Keller [H. B. Keller, in Applications of Bifurcation Theory (Academic, New York, 1977), pp. 359--384] are used to study the variation of some branches of axisymmetric Taylor vortex flow as the wavelength in the axial direction changes. Closed ''loops'' of solutions and secondary bifurcations are determined. Variations with respect to Reynolds number show the same phenomena. The results presented here show that Taylor vortices with periodic boundary conditions exist in a wider range of wavelengths, lambda, than observed in the Burkhalter/Koschmieder experiments [Phys. Fluids 17, 1929 (1974)]. They also show that there is possibly a lambda subinterval within the neutral curve of Couette flow such that there are no Taylor vortex flows with smallest period in this interval

13

Evaluation of the Synthoil process. Volume III. Unit block flow diagrams for a 100,000 barrel/stream day facility  

Energy Technology Data Exchange (ETDEWEB)

This volume consists of individual block flowsheets for the various units of the Synthoil facility, showing the overall flows into and out of each unit. Material balances for the following units are incomplete because these are proprietary processes and the information was not provided by the respective vendors: Unit 24-Claus Sulfur Plant; Unit 25-Oxygen Plant; Unit 27-Sulfur Plant (Redox Type); and Unit 28-Sour Water Stripper and Ammonia Recovery Plant. The process information in this form was specifically requested by ERDA/FE for inclusion in the final report.

Salmon, R.; Edwards, M.S.; Ulrich, W.C.

1977-06-01

14

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

15

Flow phase diagrams for concentration-coupled shear banding  

CERN Document Server

After surveying the experimental evidence for concentration coupling in the shear banding of wormlike micellar surfactant solutions, we present flow phase diagrams spanned by shear stress (or strain-rate) and concentration in the two-fluid, non-local Johnson-Segalman (d-JS-phi) model. We also present macroscopic flow curves for a range of (average) concentrations. For any concentration high enough to give shear banding, the flow curve shows the usual non-analytic kink at the onset of banding, followed by a coexistence ``plateau'' that slopes upwards. As the concentration is reduced, the width of the coexistence regime diminishes, then terminates at a non-equilibrium critical point. We outline the way in which the flow phase diagram can be reconstructed from a family of such flow curves measured for several different average concentrations. This reconstruction could be used to check new measurements of concentration differences between the coexisting bands. Our d-JS-phi model contains two spatial gradient term...

Fielding, S M; Fielding, Suzanne M; Olmsted, Peter D

2003-01-01

16

Microsoft Visio 2013 business process diagramming and validation  

CERN Document Server

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

17

Feynchois: System For Automating The Process Of Feynman Diagram Generation  

CERN Document Server

We have developed a DTD (Document Type Definition) for an XML (Extensible Markup Language) document for describing Feynman rules of quantum field theoretical models—the document is called FeynPage. A FeynPage can be any XML document that conforms to the FeynPage DTD. A FeynPage can be understood by a human or a computer program that is aware of the FeynPage DTD. We have also developed a Feynman diagram generator, which has been named FeynChois. It provides a user with a full GUI (Graphical User Interface) environment. More importantly, FeynChois knows how to read FeynPage. When FeynChois is asked by a user to generate diagrams, it will first look up the rules in the FeynPage; then, it will generate diagrams according to the rules for any process specified by the user. If the Feynman rules in a FeynPage are modified, FeynChois will generate diagrams according to the modified rules. What FeynChois generates are actually Java™ objects that represent Feynman diagrams. These objects are graphi...

Choi, C

2004-01-01

18

Andreas Acrivos Dissertation Prize Lecture: Stability of inviscid flows from bifurcation diagrams exploiting a variational argument  

Science.gov (United States)

Steady fluid solutions play a special role in the dynamics of a flow: stable states may be realized in practice, while unstable ones may act as attractors. Unfortunately, determining stability is often a process far more laborious than finding steady states; indeed, even for simple vortex or wave flows, stability properties have often been the subject of debate. We consider here a stability idea originating with Lord Kelvin (1876), which involves using the second variation of the energy, 2?E, to establish bounds on a perturbation. However, for numerically obtained flows, computing 2?E explicitly is often not feasible. To circumvent this issue, Saffman & Szeto (1980) proposed an argument linking changes in 2?E to turning points in a bifurcation diagram, for families of steady flows. Later work has shown that this argument is unreliable; the two key issues are associated with the absence of a formal turning-point theory, and with the inability to detect bifurcations (Dritschel 1995, and references therein). In this work, we build on ideas from bifurcation theory, and link turning points in a velocity-impulse diagram to changes in 2?E; in addition, this diagram delivers the direction of the change of 2?E, thereby providing information as to whether stability is gained or lost. To detect hidden solution branches, we introduce to these fluid problems concepts from imperfection theory. The resulting approach, involving ``imperfect velocity-impulse" diagrams, leads us to new and surprising results for a wide range of fundamental vortex and wave flows; we mention here the calculation of the first steady vortices without any symmetry, and the uncovering of the complete solution structure for vortex pairs. In addition, we find precise agreement with available results from linear stability analysis.

Luzzatto-Fegiz, Paolo

2011-11-01

19

Data Flow Sequences: A Revision of Data Flow Diagrams for Modelling Applications using XML  

Directory of Open Access Journals (Sweden)

Full Text Available Data Flow Diagrams were developed in the 1970’s as a method of modelling data flow when developing information systems. While DFDs are still being used, the modern web-based which is client-server based means that DFDs are not as useful. This paper proposes a modified form of DFD that incorporates, amongst other features sequences. The proposed system, called Data Flow Sequences (DFS is better able to model real world systems in a way that simplifies application development. The paper also proposes an XML implementation for DFS which allows analytical tools to be used to analyse the DFS diagrams. The paper discusses a tool that is able to detect orphan data flow sequences and other potential problems.

James PH Coleman

2013-06-01

20

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

 
 
 
 
21

Merging Object and Process Diagrams for Business Information Modeling  

CERN Document Server

While developing an information system for the University of Bern, we were faced with two major issues: managing software changes and adapting Business Information Models. Software techniques well-suited to software development teams exist, yet the models obtained are often too complex for the business user. We will first highlight the conceptual problems encountered while designing the Business Information Model. We will then propose merging class diagrams and business process modeling to achieve a necessary transparency. We will finally present a modeling tool we developed which, using pilot case studies, helps to show some of the advantages of a dual model approach.

Chénais, Patrick

2008-01-01

22

What can we learn by comparing students' diagram-construction processes with the mathematical conceptions inferred from their explanations with completed diagrams?  

Science.gov (United States)

Despite recent research interest in student-created diagrams, little research has systematically investigated students' diagram- construction processes, meaning the order and manner in which students create markings as they physically generate diagrams. In this study, we characterize the various processes students use to create diagrams that represent a quadratic motion situation involving increasing speed, and we explore how these diagram-construction processes are related to students' conceptions of speed as inferred from their explanations with their completed diagrams. Previous literature suggests contrasting predictions regarding whether or not students' diagram-construction processes are closely related (from our perspective as researchers) to students' inferred conceptions. We see the study as having value for research and practice by raising new questions related to diagram-construction processes, pointing to the potential formative assessment value of attending to diagram-construction processes, and demonstrating the need for the development of theory to explain the relationships identified by this study.

Lobato, Joanne; Hohensee, Charles; Diamond, Jaime Marie

2014-09-01

23

Simultaneous and Successive Processing of Circuit Diagrams Having Different Amounts of Detail.  

Science.gov (United States)

The instructional effectiveness of diagrams has been substantiated by research; however, research findings are limited for the identification of the conditions that are necessary for learning from diagrams. The study reported in this paper investigated certain properties of diagrams and how they relate to cognitive processes that students use when…

Winn, Bill

24

Query Processing for Probabilistic State Diagrams Describing Multiple Robot Navigation in an Indoor Environment  

Energy Technology Data Exchange (ETDEWEB)

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.

Czejdo, Bogdan [ORNL; Bhattacharya, Sambit [North Carolina Fayetteville State University; Ferragut, Erik M [ORNL

2012-01-01

25

Lifting business process diagrams to 2.5 dimensions  

Science.gov (United States)

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

26

Flow regimes and phase diagram of inertial particle suspensions  

CERN Document Server

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

27

Derivation of a Fundamental Diagram for Urban Traffic Flow  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Despite the importance of urban traffic flows, there are only a few theoretical approaches to determine fundamental relationships between macroscopic traffic variables such as the traffic density, the utilization, the average velocity, and the travel time. In the past, empirical measurements have primarily been described by fit curves. Here, we derive expected fundamental relationships from a model of traffic flows at intersections, which suggest that the recently measured f...

Helbing, Dirk

2008-01-01

28

Phase Diagrams and Fluid Properties of H2O-NaCl for Flow Simulations  

Science.gov (United States)

The system H2O-NaCl is the simplest proxy to saline fluids in the earth's crust. Such fluids play a central role in processes ranging from basinal fluid flow through hydrothermal heat transport along mid-ocean ridges to ore formation in magmatic-hydrothemal systems. Addition of NaCl strongly modifies the phase diagram of water (Driesner & Heinrich, 2007). The temperature-pressure conditions of vapor+liquid coexistence are greatly enlarged, and new phase regions of vapor+salt, liquid+salt, and vapor+liquid+salt are encountered. High contrasts in salinity, density and viscosity of vapor and liquid have profound effects on fluid flow in hydrothermal convection. Flow simulations of H2O-NaCl can be performed by choosing enthalpy, pressure and salinity as state variables. Temperature, pressure and salinity can be chosen as well and require iteration until thermal equilibrium between rock and fluid is reached. Carefully accounting for numerical precision issues and steep gradients is key to make such iterations work routinely. Two- and three-phase adiabatic compressibilities need to be employed if strict consistency of the scheme is required and to avoid singularities along the pure water boiling curve. The general setup of a numerical scheme as well as applications to natural examples will be shown. Driesner, T., and Heinrich, C.A. (2007),Geochimica et Cosmochimica Acta 71, 4880-4901.

Driesner, T.

2011-12-01

29

Applying state diagrams to food processing and development  

Science.gov (United States)

The physical state of food components affects their properties during processing, storage, and consumption. Removal of water by evaporation or by freezing often results in formation of an amorphous state (Parks et al., 1928; Troy and Sharp, 1930; Kauzmann, 1948; Bushill et al., 1965; White and Cakebread, 1966; Slade and Levine, 1991). Amorphous foods are also produced from carbohydrate melts by rapid cooling after extrusion or in the manufacturing of hard sugar candies and coatings (Herrington and Branfield, 1984). Formation of the amorphous state and its relation to equilibrium conditions are shown in Fig. 1 [see text]. The most important change, characteristic of the amorphous state, is noticed at the glass transition temperature (Tg), which involves transition from a solid "glassy" to a liquid-like "rubbery" state. The main consequence of glass transition is an increase of molecular mobility and free volume above Tg, which may result in physical and physico-chemical deteriorative changes (White and Cakebread, 1966; Slade and Levine, 1991). We have conducted studies on phase transitions of amorphous food materials and related Tg to composition, viscosity, stickiness, collapse, recrystallization, and ice formation. We have also proposed that some diffusion-limited deteriorative reactions are controlled by the physical state in the vicinity of Tg (Roos and Karel, 1990, 1991a, b, c). The results are summarized in this article, with state diagrams based on experimental and calculated data to characterize the relevant water content, temperature, and time-dependent phenomena of amorphous food components.

Roos, Y.; Karel, M.

1991-01-01

30

Fundamental Diagrams of 1D-Traffic Flow by Optimal Control Models  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Traffic on a circular road is described by dynamic programming equations associated to optimal control problems. By solving the equations analytically, we derive the relation between the average car density and the average car flow, known as the fundamental diagram of traffic. First, we present a model based on min-plus algebra, then we extend it to a stochastic dynamic programming model, then to a stochastic game model. The average car flow is derived as the average cost pe...

Farhi, Nadir

2010-01-01

31

Interpreting Evolutionary Diagrams: When Topology and Process Conflict  

Science.gov (United States)

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

32

Phase diagrams of laser-processed nanoparticles of brass  

International Nuclear Information System (INIS)

Nanoparticles of brass are prepared by ablation of a brass target in ethanol using radiation of a copper-vapor laser at various laser fluences. The nanoparticles are characterized by TEM and optical spectroscopy. The multipulse laser irradiation leads to formation both the nanoparticles in liquid and well-ordered micro-structures on a surface of a target. It is revealed that both the morphology and absorption spectra of brass nanoparticles depend on presence of the micro-structures. Nanoparticles with the various phase diagrams are formed from a flat brass surface and from the same surface with micro-structures. The results are compared with a model of phase diagrams, in which size and composition effects are taken into account

33

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

Science.gov (United States)

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

34

Flow Effects on the Flammability Diagrams of Solid Fuels: Microgravity Influence on Ignition Delay  

Science.gov (United States)

The possibility of an accidental fire in space-based facilities is a primary concern of space exploration programs. Spacecraft environments generally present low velocity air currents produced by ventilation and heating systems (of the order of 0.1 m/s), and fluctuating oxygen concentrations around that of air due to CO2 removal systems. Recent experiments of flame spread in microgravity show the spread rate to be faster and the limiting oxygen concentration lower than in normal-gravity. To date, there is not a material flammability-testing protocol that specifically addresses issues related to microgravity conditions. The present project (FIST) aims to establish a testing methodology that is suitable for the specific conditions of reduced gravity. The concepts underlying the operation of the LIFT apparatus, ASTM-E 1321-93, have been used to develop the Forced-flow Ignition and flame-Spread Test (FIST). As in the LIFT, the FIST is used to obtain the flammability diagrams of the material, i.e., graphs of ignition delay time and flame spread rate as a function of the externally applied radiant flux, but under forced flow rather than natural convection conditions, and for different oxygen concentrations. Although the flammability diagrams are similar, the flammability properties obtained with the FIST are found to depend on the flow characteristics. A research program is currently underway with the purpose of implementing the FIST as a protocol to characterize the flammability performance of solid materials to be used in microgravity facilities. To this point, tests have been performed with the FIST apparatus in both normal-gravity and microgravity conditions to determine the effects of oxidizer flow characteristics on the flammability diagrams of polymethylmethacrylate (PMMA) fuel samples. The experiments are conducted at reduced gravity in a KC- 135 aircraft following a parabolic flight trajectory that provides up to 25 seconds of low gravity. The objective of the experiments is to obtain data of ignition delay and flame spread rate at low flow velocities (0.1 to 0.2 m/s), which cannot be obtained under normal gravity because of the natural convection induced flows (approx. 0.5 m/s). Due to the limited reduced gravity time, the data can only be obtained for high radiant fluxes, and are consequently limited in scope. These tests do, however, provide insight into the flammability diagram characteristics at low velocity and reduced gravity, and also into the implications of the flow-dependence of the flammability properties under environments similar to those encountered in space facilities.

Cordova, J. L.; Walther, D. C.; Fernandez-Pello, A. C.; Steinhaus, T.; Torero, J. L.; Quintere, J. G.; Ross, H. D.

1999-01-01

35

Quantitative carbon partitioning diagrams for Waspaloy and their application to chemistry modifications and processing  

International Nuclear Information System (INIS)

Partitioning of carbon between MC, M23C6 and a solid solution was measured for Waspaloy in support of homogenization, chemistry modification, and thermomechanical processing programs. Carbon partitioning diagrams were developed for high, medium, and low carbon ingots. Analysis of wrought samples with selected heat treatments permitted extrapolation of ingot diagrams to wrought structures. Changes in carbon partitioning, resulting from lower cobalt and the addition of niobium, were determined

36

Development of the Functional Flow Block Diagram for the J-2X Rocket Engine System  

Science.gov (United States)

The J-2X program calls for the upgrade of the Apollo-era Rocketdyne J-2 engine to higher power levels, using new materials and manufacturing techniques, and with more restrictive safety and reliability requirements than prior human-rated engines in NASA history. Such requirements demand a comprehensive systems engineering effort to ensure success. Pratt & Whitney Rocketdyne system engineers performed a functional analysis of the engine to establish the functional architecture. J-2X functions were captured in six major operational blocks. Each block was divided into sub-blocks or states. In each sub-block, functions necessary to perform each state were determined. A functional engine schematic consistent with the fidelity of the system model was defined for this analysis. The blocks, sub-blocks, and functions were sequentially numbered to differentiate the states in which the function were performed and to indicate the sequence of events. The Engine System was functionally partitioned, to provide separate and unique functional operators. Establishing unique functional operators as work output of the System Architecture process is novel in Liquid Propulsion Engine design. Each functional operator was described such that its unique functionality was identified. The decomposed functions were then allocated to the functional operators both of which were the inputs to the subsystem or component performance specifications. PWR also used a novel approach to identify and map the engine functional requirements to customer-specified functions. The final result was a comprehensive Functional Flow Block Diagram (FFBD) for the J-2X Engine System, decomposed to the component level and mapped to all functional requirements. This FFBD greatly facilitates component specification development, providing a well-defined trade space for functional trades at the subsystem and component level. It also provides a framework for function-based failure modes and effects analysis (FMEA), and a rigorous baseline for the functional architecture.

White, Thomas; Stoller, Sandra L.; Greene, WIlliam D.; Christenson, Rick L.; Bowen, Barry C.

2007-01-01

37

Power diagrams and interaction processes for unions of discs  

DEFF Research Database (Denmark)

 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-Poincaré 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

MØller, Jesper; Helisova, Katerina

2008-01-01

38

Multi-Particle Processes in QCD without Feynman Diagrams  

CERN Document Server

A way to efficiently compute helicity amplitudes for arbitrary tree-level scattering processes in QCD is presented. The scattering amplitude is evaluated recursively through a set of Dyson-Schwinger equations. The computational cost of this algorithm grows asymptotically as 3^n, 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 the Monte Carlo techniques.

Papadopoulos, C G; Papadopoulos, Costas G.; Worek, Malgorzata

2006-01-01

39

Multi-particle processes in QCD without Feynman diagrams  

International Nuclear Information System (INIS)

A way to efficiently compute helicity amplitudes for arbitrary tree-level scattering processes in QCD 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 the Monte Carlo techniques

40

The organization of intrinsic computation: Complexity-entropy diagrams and the diversity of natural information processing  

Science.gov (United States)

Intrinsic computation refers to how dynamical systems store, structure, and transform historical and spatial information. By graphing a measure of structural complexity against a measure of randomness, complexity-entropy diagrams display the different kinds of intrinsic computation across an entire class of systems. Here, we use complexity-entropy diagrams to analyze intrinsic computation in a broad array of deterministic nonlinear and linear stochastic processes, including maps of the interval, cellular automata, and Ising spin systems in one and two dimensions, Markov chains, and probabilistic minimal finite-state machines. Since complexity-entropy diagrams are a function only of observed configurations, they can be used to compare systems without reference to system coordinates or parameters. It has been known for some time that in special cases complexity-entropy diagrams reveal that high degrees of information processing are associated with phase transitions in the underlying process space, the so-called "edge of chaos." Generally, though, complexity-entropy diagrams differ substantially in character, demonstrating a genuine diversity of distinct kinds of intrinsic computation.

Feldman, David P.; McTague, Carl S.; Crutchfield, James P.

2008-12-01

 
 
 
 
41

The organization of intrinsic computation: complexity-entropy diagrams and the diversity of natural information processing.  

Science.gov (United States)

Intrinsic computation refers to how dynamical systems store, structure, and transform historical and spatial information. By graphing a measure of structural complexity against a measure of randomness, complexity-entropy diagrams display the different kinds of intrinsic computation across an entire class of systems. Here, we use complexity-entropy diagrams to analyze intrinsic computation in a broad array of deterministic nonlinear and linear stochastic processes, including maps of the interval, cellular automata, and Ising spin systems in one and two dimensions, Markov chains, and probabilistic minimal finite-state machines. Since complexity-entropy diagrams are a function only of observed configurations, they can be used to compare systems without reference to system coordinates or parameters. It has been known for some time that in special cases complexity-entropy diagrams reveal that high degrees of information processing are associated with phase transitions in the underlying process space, the so-called "edge of chaos." Generally, though, complexity-entropy diagrams differ substantially in character, demonstrating a genuine diversity of distinct kinds of intrinsic computation. PMID:19123616

Feldman, David P; McTague, Carl S; Crutchfield, James P

2008-12-01

42

Phase diagram of the symbiotic two-species contact process  

Science.gov (United States)

We study the two-species symbiotic contact process, recently proposed by de Oliveira, Santos, and Dickman [Phys. Rev. E 86, 011121 (2012), 10.1103/PhysRevE.86.011121]. In this model, each site of a lattice may be vacant or host single individuals of species A and/or B. Individuals at sites with both species present interact in a symbiotic manner, having a reduced death rate ? species may be vulnerable to sudden extinction under increasingly adverse conditions.

de Oliveira, Marcelo Martins; Dickman, Ronald

2014-09-01

43

FMEF Electrical single line diagram and panel schedule verification process  

International Nuclear Information System (INIS)

Since the FMEF did not have a mission, a formal drawing verification program was not developed, however, a verification process on essential electrical single line drawings and panel schedules was established to benefit the operations lock and tag program and to enhance the electrical safety culture of the facility. The purpose of this document is to provide a basis by which future landlords and cognizant personnel can understand the degree of verification performed on the electrical single lines and panel schedules. It is the intent that this document be revised or replaced by a more formal requirements document if a mission is identified for the FMEF

44

Dinosaur Extinction: Causal Loop Diagram of Earth Feedback System  

Science.gov (United States)

This site features a causal loop diagram from system dynamics methodology showing the solar-earth-space energy flow system (the dominant flow system driving earth's surficial systems, including the biosphere) and interactive natural earthly processes that influence it. Also included is a discussion of the diagram, and a link to a page that explains how to read causal loop diagrams.

Mclean, Dewey M.; Tech, Virginia

45

IGDS/TRAP Interface Program (ITIP). Software User Manual (SUM). [network flow diagrams for coal gasification studies  

Science.gov (United States)

This specification establishes the requirements, concepts, and preliminary design for a set of software known as the IGDS/TRAP Interface Program (ITIP). This software provides the capability to develop at an Interactive Graphics Design System (IGDS) design station process flow diagrams for use by the NASA Coal Gasification Task Team. In addition, ITIP will use the Data Management and Retrieval System (DMRS) to maintain a data base from which a properly formatted input file to the Time-Line and Resources Analysis Program (TRAP) can be extracted. This set of software will reside on the PDP-11/70 and will become the primary interface between the Coal Gasification Task Team and IGDS, DMRS, and TRAP. The user manual for the computer program is presented.

Jefferys, S.; Johnson, W.; Lewis, R.; Rich, R.

1981-01-01

46

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

47

High-energy, large-momentum-transfer processes: Ladder diagrams in ?3 theory. Pt. 1  

International Nuclear Information System (INIS)

Relativistic quantum field theories may give us useful guidance to understanding high-energy, large-momentum-transfer processes, where the center-of-mass energy is much larger than the transverse momentum transfers, which are in turn much larger than the masses of the participating particles. With this possibility in mind, we study the ladder diagrams in ?3 theory. In this paper, some of the necessary techniques are developed and applied to the simplest cases of the fourth- and sixth-order ladder diagrams. (orig.)

48

Display the CIE 1931 color chromaticity diagram with digital image processing  

Science.gov (United States)

The chromaticity diagram is also needed in the instrument of a non-contact system for measuring color of printed material. The purpose of this paper is to design the color chromaticity diagram identical with the CIE 1931 and its program in MATLAB with digital image processing is realized. The chromaticity diagram in a binary format representation as black and white is used and the boundary for every color is confined by a closed black real line. More than 20 kinds of colors are selected by the psychophysiology of vision according to the CIE 1931 and their values in RGB are also are given. After every region colors are put in, the closed black real lines are wiped away and their values of RGB are updated according to the value for the nearest color region. The program including the filters in RGB space run until the all steps between every two colors up to the psychophysiology of vision, the chromaticity diagram is obtained. The values of RGB in every position in the chromaticity diagram can be presented.

Zhao, Hong-Dong; Yao, Yi-Yang; Sun, Fei; Zhang, Qin; Yang, Xiao-Hui

2013-12-01

49

High-energy, large-momentum-transfer processes: Ladder diagrams in var-phi 3 theory  

International Nuclear Information System (INIS)

Relativistic quantum field theories may help one to understand high-energy, large-momentum-transfer processes, where the center-of-mass energy is much larger than the transverse momentum transfers, which are in turn much larger than the masses of the participating particles. With this possibility in mind, the author studies ladder diagrams in var-phi 3 theory. He shows that in the limit s much-gt |t| much-gt m2, the scattering amplitude for the N-rung ladder diagram takes the form s-1|t|-N+1 times a homogeneous polynomial of degree 2N - 2 and ln s and ln |t|. This polynomial takes different forms depending on the relation of ln |t| to ln s. More precisely, the asymptotic formula for the N-rung ladder diagram has points of non-analytically when ln |t| = ? ln s for ? = 1/2, 1/3, hor-ellipsis, 1/N-2

50

Phase diagrams of heterogeneous traffic flow at a single intersection in a deterministic Fukui-Ishibashi cellular automata traffic model  

Science.gov (United States)

This paper studies heterogeneous traffic flow that comprises two types of vehicles with different lengths at a single intersection consisting of two perpendicular one-lane roads. Based on theoretical analysis and computer simulations, we have presented the phase diagrams which consist of five regions and the topological structure of which is independent of the maximum velocity of vehicles m. The analytical formulas of the flows on the two roads have been obtained in all regions of the phase diagram, which depends on whether m is even or odd or m = 1. The analytical formulas are in good agreement with simulation results.

Li, Qi-Lang; Jiang, Rui; Min, Jie; Xie, Jia-Rong; Wang, Bing-Hong

2014-10-01

51

Clustering and state diagram of charged colloids with short-range attraction in shear flows  

Science.gov (United States)

Under static conditions, the superposition of short-range (e.g. van der Waals) attraction and electrostatic repulsion gives rise to interesting phases such as equilibrium clusters in globular protein suspensions. What is much less understood is their behavior under external flow, which is important for the physiological aggregation of proteins and for industrial systems as well. I will present theoretical and experimental results showing that clustering of these systems in shear flow is characterized by the crossover from a reaction-limited clustering kinetics at low shear into a convection-dominated aggregation regime at high Peclet numbers. The kinetics may rise by up to many orders of magnitude in the crossover regime. This behavior is due to the singularly-perturbed character of the governing diffusion equation where the shear drift term induces a singularity and a boundary-layer at large interparticle distances. This understanding, together with a theoretical description of cluster breakup, is used to rationalize the peculiar nonequilibrium state diagram (including gelation) of these colloidal suspensions in shear flow with applications ranging from microfluidic self-assembly to proteins.

Zaccone, Alessio; Morbidelli, Massimo

2013-03-01

52

Padé approximants, optimal renormalization scales, and momentum flow in Feynman diagrams  

CERN Document Server

We show that the Padé Approximant (PA) approach for resummation of perturbative series in QCD provides a systematic method for approximating the flow of momentum in Feynman diagrams. In the large-$\\beta_0$ limit, diagonal PA's generalize the Brodsky-Lepage-Mackenzie (BLM) scale-setting method to higher orders in a renormalization scale- and scheme-invariant manner, using multiple scales that represent Neubert's concept of the distribution of momentum flow through a virtual gluon. If the distribution is non-negative, the PA's have only real roots, and approximate the distribution function by a sum of delta-functions, whose locations and weights are identical to the optimal choice provided by the Gaussian quadrature method for numerical integration. We show how the first few coefficients in a perturbative series can set rigorous bounds on the all-order momentum distribution function, if it is positive. We illustrate the method with the vacuum polarization function and the Bjorken sum rule computed in the large...

Brodsky, S J; Gardi, E; Karliner, M M; Samuel, Mark A; Brodsky, Stanley J.; Ellis, John; Gardi, Einan; Karliner, Marek; Samuel, Mark. A.

1997-01-01

53

Determining the stability of steady inviscid flows through ``Imperfect Velocity-Impulse'' diagrams  

Science.gov (United States)

More than a century ago, Lord Kelvin proposed a variational argument for determining the stability of steady inviscid flows; while the underpinnings of the method are well established, its application has been the subject of extensive debate. Considering, for example, a vortex configuration rotating at a rate ? with impulse J and energy E, Kelvin argued that an equilibrium corresponds to a stationary point of H = E -?J. Since H is conserved, the second variation 2?H constrains the dynamics and can be used to assess stability. Unfortunately, computation of 2?H is often impossible or impractical. Saffman & Szeto (1980) suggested that extrema in a plot of E vs J could be used to identify changes in 2?H. However, Dritschel (1985) later pointed out the lack of a firm link between 2?H and a plot of E vs J. Furthermore, he stated that even if such link could be proven, changes of stability could also occur, at bifurcations, away from extrema in E and J. We address both issues by proposing a new approach. We introduce a theorem from dynamical systems theory to prove that extrema in a plot of J vs ? (instead of E vs J) are indeed related to the properties of 2?H, while we use ideas from imperfection theory to ensure that bifurcations are detected by means of an ``imperfect velocity-impulse'' (IVI) diagram. By applying our approach to several classical flows, we obtain stability results in agreement with linear analysis, while additionally discovering new steady solutions.

Luzzatto-Fegiz, P.; Williamson, C. H. K.

2008-11-01

54

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

55

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

56

Two-state shear diagrams for complex fluids in shear flow  

CERN Document Server

The possible ``phase diagrams'' for shear-induced phase transitions between two phases are collected. We consider shear-thickening and shear-thinning fluids, under conditions of both common strain rate and common stress in the two phases, and present the four fundamental shear stress vs. strain-rate curves and discuss their concentration dependence. We outline how to construct more complicated phase diagrams, discuss in which class various experimental systems fall, and sketch how to reconstruct the phase diagrams from rheological measurements.

Olmsted, P D

1999-01-01

57

Stability of Conservative Flows and New Steady-Fluid Solutions from Bifurcation Diagrams Exploiting a Variational Argument  

Science.gov (United States)

In this Letter, we address two issues affecting the use of a variational argument to determine stability of conservative fluid systems. We build on ideas from bifurcation theory, and thereby for families of steady flows, we link turning points in a velocity-impulse diagram to gains or losses of stability. We further introduce concepts from imperfection theory into these problems, enabling us to reveal hidden solution branches. Our approach applies to a wide range of flows. As an illustration involving a well-defined problem, we study a pair of counterrotating vortices. The approach results in stability boundaries in agreement with linear analysis, yet further enables us to discover a new family of steady vortices, which surprisingly do not exhibit any symmetry. All applications of our approach so far, using imperfect-velocity-impulse (IVI) diagrams, lead us to the discovery of lower-symmetry solutions.

Luzzatto-Fegiz, Paolo; Williamson, Charles H. K.

2010-01-01

58

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 ?-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 Hoare’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 ?-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

59

Systematic fuel cycle systems engineering from 2D flow diagrams to 3D layout  

Energy Technology Data Exchange (ETDEWEB)

The ITER fuel cycle systems are designed to supply deuterium-tritium gas mixtures to the ITER fueling systems and to process return gas streams from the vacuum vessel forming the closed inner fuel cycle. The radioactive nature of tritium requires implementation of a multiple barrier concept in order to assure the confinement of tritium within the process equipment. Ventilation and vent detritiation systems are the part of a dynamic confinement barrier which prevents tritium releases to the environment. The ITER fuel cycle systems, ventilation and tritium confinement systems all together form a rather complex chemical plant - the ITER Tritium Plant. Not only because of the complexity of the inner fuel cycle systems and numerous interfaces to the other systems within tritium plant but also because of the procurement sharing integrated planning is required. Interfaces management, configuration control and systems integration requires proper CAD tools and Project Data Management systems. CATIA V4 has been used in the past in ITER for 3D planning. However, only today's version of the software allows linking of the primarily 2D Pipe and Instrumentation Diagrams (P and IDs) into detailed 3D design and layout. The capabilities of the software were demonstrated through proof of principle activities in the ITER CAD office, eventually leading to the decision to deploy CATIA V5 Equipment and Systems (E and S) as general purpose single CAD tool for the design and integration of the ITER electrical, fluid and mechanical systems. In order to meet engineering requirements of ITER the CATIA V5 E and S project structure and project resources have been established starting from systems classifications, followed by the implementation of the applicable industrial standards, specifications and systems elements libraries into the Project Resources Management (PRM). Catalogues for the piping parts, piping specifications and standards specific for the design of the tritium processing systems and tritium confinement systems will assure implementation of the Design Guidelines and Quality Requirements for the Tritium Plant systems including the standardization of the equipment and design. The paper describes the CATIA V5 E and S project structure, the procedures to develop and maintain the PRM and how the tool is employed to detail the design of Tritium Plant systems. (orig.)

Beloglazov, S.; Glugla, M.; Lux, M.; Wagner, R.; Weber, V. [Forschungszentrum Karlsruhe (Germany); Chiocchio, S.; Kuehn, I.; Martin, E. [ITER Joint Work Site, Cadarache Centre, St Paul lez Durance (France)

2007-07-01

60

Systematic fuel cycle systems engineering from 2D flow diagrams to 3D layout  

International Nuclear Information System (INIS)

The ITER fuel cycle systems are designed to supply deuterium-tritium gas mixtures to the ITER fueling systems and to process return gas streams from the vacuum vessel forming the closed inner fuel cycle. The radioactive nature of tritium requires implementation of a multiple barrier concept in order to assure the confinement of tritium within the process equipment. Ventilation and vent detritiation systems are the part of a dynamic confinement barrier which prevents tritium releases to the environment. The ITER fuel cycle systems, ventilation and tritium confinement systems all together form a rather complex chemical plant - the ITER Tritium Plant. Not only because of the complexity of the inner fuel cycle systems and numerous interfaces to the other systems within tritium plant but also because of the procurement sharing integrated planning is required. Interfaces management, configuration control and systems integration requires proper CAD tools and Project Data Management systems. CATIA V4 has been used in the past in ITER for 3D planning. However, only today's version of the software allows linking of the primarily 2D Pipe and Instrumentation Diagrams (P and IDs) into detailed 3D design and layout. The capabilities of the software were demonstrated through proof of principle activities in the ITER CAD office, eventually leading to the decision to deploy CATIA V5 Equipment and Systems (E and S) as general purpose single CAD tool for the design and integration of the ITER electrical, fluid and mechanical systems. In order to meet engineering requirements of ITER the CATIA V5 E and S project structure and project resources have been established starting from systems classifications, followed by the implementation of the applicable industrial standards, specifications and systems elements libraries into the Project Resources Management (PRM). Catalogues for the piping parts, piping specifications and standards specific for the design of the tritium processing systems and tritium confinement systems will assure implementation of the Design Guidelines and Quality Requirements for the Tritium Plant systems including the standardization of the equipment and design. The paper describes the CATIA V5 E and S project structure, the procedures to develop and maintain the PRM and how the tool is employed to detail the design of Tritium Plant systems. (orig.)

 
 
 
 
61

Preliminary investigation of processing and phase diagram construction in the Y-Sr-Cu-O system  

International Nuclear Information System (INIS)

This paper investigates the Y-Sr-Cu-O system which has been reported to from a K2NiF4-type superconducting phase (Tc ? 40 K) and a 123-type phase (Tc ? 80 K). Difficulties in preparing single phase materials by standard solid state reaction of carbonates and oxides have compelled us to explore other methods. A two-stage solid state processing technique in addition to a coprecipitation method will be discussed along with the relative advantages and disadvantages of each. Using data obtained from XRD and EDS, we have mapped some of the YO1.5SrO-CuO ternary phase diagram in anticipation of continued efforts at single crystal growth

62

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

Science.gov (United States)

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

63

Water conservation and reuse using the Water Sources Diagram method for batch process: case studies  

Directory of Open Access Journals (Sweden)

Full Text Available The water resources management has been an important factor for the sustainability of industrial processes, since there is a growing need for the development of methodologies aimed at the conservation and rational use of water. The objective of this work was to apply the heuristic-algorithmic method called Water Sources Diagram (WSD, which is used to define the target of minimum water consumption, to batch processes. Scenarios with reuse of streams were generated and evaluated with application of the method from the data of water quantity and concentration of contaminants in the operations. Two case studies aiming to show the reduction of water consumption and wastewater generation, and final treatment costs besides investment in storage tanks, were presented. The scenarios showed great promising, achieving reduction up to 45% in water consumption and wastewater generation, and a reduction of around 37% on cost of storage tanks, without the need to allocate regeneration processes. Thus, the WSD method showed to be a relevant and flexible alternative regarding to systemic tools aimed at minimizing the consumption of water in industrial processes, playing an important role within a program of water resources management.

Fernando Luiz Pellegrini Pessoa

2012-04-01

64

CONVERSIÓN DE DIAGRAMAS DE PROCESOS EN DIAGRAMAS DE CASOS DE USO USANDO AToM³ / CONVERSION OF PROCESSES DIAGRAMS IN USE CASE DIAGRAMS USING AToM³  

Scientific Electronic Library Online (English)

Full Text Available SciELO Colombia | Language: Spanish Abstract in spanish Toda pieza de software se origina en el modelo verbal, con el cual se pueden definir los diferentes modelos conceptuales que acerquen el problema a una solución. Las herramientas convencionales para la construcción de los modelos conceptuales no toman en consideración las diferentes reglas de consis [...] tencia que se pueden presentar entre los diferentes modelos. En este artículo se emplea el AToM³ como herramienta para la definición de los meta-modelos del diagrama de procesos y el diagrama de casos de uso, con el fin de reexpresar el primero para obtener algunos elementos básicos del segundo. Abstract in english Every software piece has its origins in the verbal model. With this model, it’s possible to define several conceptual models that allow reaching a solution closer to the problem. Conventional tools for conceptual model building don’t take into account the different consistency rules between differen [...] t models. In this paper we use AToM³ as a tool for the meta-models’ definition of process diagram and use case diagrams, trying to redefine the first to obtain some basic elements from the second.

CARLOS M., ZAPATA J.; CARLOS ALBERTO, ÁLVAREZ..

65

Preliminary velocity flows inside NOA AR 10720 derived by temporally evolving ring diagram analysis of SOHO/MDI dopplergrams  

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.

66

Learning with Diagrams.  

Science.gov (United States)

Argues that diagram interpretation is largely text-dependent and is also dependent upon the use of particular diagram-processing skills which may be very difficult to develop. Discusses some interpretation difficulties and advances strategies to help teachers make more effective use of diagrams. (Contains 20 references.) (Author/WRM)

Henderson, Garry

1999-01-01

67

Twistor diagrams  

International Nuclear Information System (INIS)

The study of twistor diagrams is motivated by analogy with the Feynman diagrams of quantum field theory. The authors discuss the twistor diagrams corresponding to the scalar product of massless free fields and to a phi4-type interactions. (Auth.)

68

P-T-x-phase diagrams and analysis of sublimation processes  

International Nuclear Information System (INIS)

In the review the problem of complete P-T-x-phase diagram olotting and possibilities of mass-spectrometric method application for the purpose are considered. Types of P-T- and T-x-projections of phase diagrams and the character of sublimation of double compounds formed for such systems as KF-ZrF4, LiF-ZrF4, NaF-ThF4 in the temperature range 400-1000 deg C and pressure range 1x10-6-3 mm Hg are analyzed. An attempt is made, using the systems as an example, to show that according to the type of T-x projections of a phase diagram it is possible to make a conclusion on the character of double compound sublimation. Nonvariant and singular points in P-T-x phase diagrams of bicomponent systems are considered

69

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

International Nuclear Information System (INIS)

Recent work by Phillips et al., and Selby et al., has shown that influence diagram methodology can be a useful analytical tool in reactor safety studies. An influence diagram is a graphical representation of probabilistic dependence within a system or event sequence. Bayesian statistics are employed to transform the relationships depicted in the influence diagram into the correct expression for a desired marginal probability (e.g. the top event). As with fault trees, top-down and bottom-up algorithms have emerged as the dominant methods for quantifying influence diagrams. Purpose of this paper is to demonstrate a potential error in employing the bottom-up algorithm when dealing with interdependencies. In addition, the computing efficiency of both methods is discussed

70

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

71

Value of the maximal expiratory flow-volume diagram in a longitudinal study  

Energy Technology Data Exchange (ETDEWEB)

In a 4-year follow-up we have measured the maximal expiratory flow-volume curve in a random sample of the population of a hydrogen chloride air-polluted area. At the first investigation the pressure transducer of our pneumotachograph had shown an unsatisfactory frequency characteristic. Therefore the initial flow of the flow-volume curve (PEF and MEF 75) were underestimated. The values for asymptomatic non-smokers of the restudy were in good accordance with reference values of other authors. On both occasions we found significant differences between smokers and non-smokers and between persons with and without bronchitis. The lung function data correlated also with tobacco consumption. There was no evidence for superiority of the maximal expiratory flow rates over the conventional spirometric parameters FEV1 and FVC.

Evers, H.; Herrmann, H.; Ohme, G.

1985-01-01

72

Dynamics and phase diagrams for highly non-spherical vesicles in shear flow computed with Loop subdivision surfaces  

Science.gov (United States)

Vesicles, particularly those with a low volume to surface area ratio, are challenging to simulate due to the presence of a surface incompressibility constraint and a bending energy that requires a highly accurate estimate of curvature. A boundary integral method based on Loop subdivision surfaces on an unstructured mesh is used to compute phase diagrams and stress dynamics for highly non-spherical vesicles in shear flow. In addition to the most commonly studied prolate family of vesicles, we also investigate the biconcave and stomatocyte shapes. We chronicle the decrease in the viscosity ratio threshold needed to trigger transition between the regimes of tank treading, trembling, tumbling, and kayaking as the reduced volume ratio of a prolate vesicle decreases. For biconcave shapes, we observe three regimes: conversion to prolate, tank treading, and tumbling. We find that biconcave tumbling near the critical viscosity ratio is not merely a rotation motion and includes noteworthy stretching in the vorticity direction.

Spann, Andrew; Zhao, Hong; Shaqfeh, Eric

2011-11-01

73

Global structure of periodicity hubs in Lyapunov phase diagrams of dissipative flows.  

Science.gov (United States)

Infinite cascades of periodicity hubs were predicted and very recently observed experimentally to organize stable oscillations of some dissipative flows. Here we describe the global mechanism underlying the genesis and organization of networks of periodicity hubs in control parameter space of a simple prototypical flow, namely a Rössler's oscillator. We show that spirals associated with periodicity hubs emerge and accumulate at the folding of certain fractal-like sheaves of Shilnikov homoclinic bifurcations of a common saddle-focus equilibrium. The specific organization of hub networks is found to depend strongly on the interaction between the homoclinic orbits and the global structure of the underlying attractor. PMID:21867282

Vitolo, Renato; Glendinning, Paul; Gallas, Jason A C

2011-07-01

74

Visualization and picture processing of turbulent flow  

Science.gov (United States)

The tracer method was used to visualize the three-dimensional structure of turbulent open-channel flow. A horizontal cross-section of the flow was illuminated by light passing through a thin slit. The illuminated cross-section was shifted upward, and at the time, successive pictures of flow patterns were taken. The picture-taking system was then shifted in downstream direction to follow the flow structures. The pictures obtained were processed by computer. Various kinds of physical properties of the flow were quantitatively evaluated and displayed as graphical outputs. These results contribute to the elucidation of the three-dimensional structure of turbulent open-channel flows.

Utami, T.; Ueno, T.

1984-03-01

75

Chemical reactions and processes under flow conditions  

CERN Document Server

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

76

ALGAE REMOVAL BY THE OVERLAND FLOW PROCESS  

Science.gov (United States)

Control of algae production will be necessary when lagoons are utilized as a preapplication treatment process for overland flow. The overland flow process has a surface discharge and must meet secondary treatment limitations to be viable. Brief summaries of other algae removal in...

77

Projection of postgraduate students flow with a smoothing matrix transition diagram of Markov chain  

Science.gov (United States)

This paper presents a case study of modeling postgraduate students flow at the College of Art and Sciences, Universiti Utara Malaysia. First, full time postgraduate students and the semester they were in are identified. Then administrative data were used to estimate the transitions between these semesters for the year 2001-2005 periods. Markov chain model is developed to calculate the -5 and -10 years projection of postgraduate students flow at the college. The optimization question addressed in this study is 'Which transitions would sustain the desired structure in the dynamic situation such as trend towards graduation?' The smoothed transition probabilities are proposed to estimate the transition probabilities matrix of 16 × 16. The results shows that using smoothed transition probabilities, the projection number of postgraduate students enrolled in the respective semesters are closer to actual than using the conventional steady states transition probabilities.

Rahim, Rahela; Ibrahim, Haslinda; Adnan, Farah Adibah

2013-04-01

78

Digital image processing for flow visualization  

International Nuclear Information System (INIS)

The digital image processing for flow visualization pictures, including air-bubble, smoke tunnel, schlieren, and interference are described. The methods of calculating data are provided. The histogram equalization, spatial convolution, exponential transform, and Wallis transform are introduced

79

The diagram of pH values in the liquid and steam phases during a change in the aggregate state of H2O in the process circuit of nuclear and thermal power stations  

Science.gov (United States)

We present data on the effect the pH value of liquid film has on the rate of erosion-corrosion processes in the metal of thermal and nuclear power station elements operating with two-phase flows. We also suggest a calculation diagram and an engineering procedure for determining the pH value of liquid phase in the wet-steam paths of power units depending on the concentration of corrective additions, steam wetness ratio, and temperature.

Tomarov, G. V.; Shipkov, A. A.

2010-07-01

80

Visualization design and verification of Ada tasking using timing diagrams  

Science.gov (United States)

The use of timing diagrams is recommended in the design and testing of multi-task Ada programs. By displaying the task states vs. time, timing diagrams can portray the simultaneous threads of data flow and control which characterize tasking programs. This description of the system's dynamic behavior from conception to testing is a necessary adjunct to other graphical techniques, such as structure charts, which essentially give a static view of the system. A series of steps is recommended which incorporates timing diagrams into the design process. Finally, a description is provided of a prototype Ada Execution Analyzer (AEA) which automates the production of timing diagrams from VAX/Ada debugger output.

Vidale, R. F.; Szulewski, P. A.; Weiss, J. B.

1986-01-01

 
 
 
 
81

Mollier-I, S-Diagrams for Combustion Gases in Data Processing  

Science.gov (United States)

In order to have all the thermal and caloric states of combustion gases accessible in a computer, closed mathematical approximation equations were established for the real factors, the enthalpy and the entropy of a real combustion gas. The equations approximate the various effects of molecular forces real gas influence and dissociation - at temperatures of 200 K to 6,000 K, pressures of 0.001 to 1,000 bar, and in the range from stoichiometric composition to air. A system of subprograms is listed in FORTRAN, by means of which thermodynamic calculations can be carried out in the same manner as with Mollier I,S diagrams.

Zacharias, F.

1982-01-01

82

Carroll Diagrams  

Science.gov (United States)

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

83

Lucidchart: Diagramming  

Science.gov (United States)

For all those who have wrestled with creating charts and diagrams in word processors, the Google Chrome application Lucidchart may be a long-awaited answer. Users can start using the intuitive drag-and-drop interface right away, although a free signup is required to save diagrams. By sharing a link with coworkers, project collaborators can work on the same diagram at the same time. This application is compatible with all computers running Google Chrome.

2012-08-24

84

Investigation of the free flow electrophoretic process  

Science.gov (United States)

The effects of gravity on the free flow electrophoretic process was demonstrated. The free flow electrophoresis chamber used to demonstrate the effects of gravity on the process was of a proprietary design. This chamber was 120 cm long, 16 cm wide, and 0.15 cm thick. Flow in this chamber was in the upward direction and exited through 197 outlets at the top of the chamber. During electrophoresis a stream of sample was injected into the flow near the bottom of the chamber and an electrical field was applied across the width of the chamber. The field caused a lateral force on particles in the sample proportional to the inherent change of the particle and the electric field strength. Particle lateral velocity was then dependent on the force due to viscous drag which was proportional to particle size and particle shape dependent.

Weiss, R. A.; Lanham, J. W.; Richman, D. W.; Walker, C. D.

1980-01-01

85

Stable stationary processes related to cyclic flows  

CERN Document Server

We study stationary stable processes related to periodic and cyclic flows in the sense of Rosinski [Ann. Probab. 23 (1995) 1163-1187]. These processes are not ergodic. We provide their canonical representations, consider examples and show how to identify them among general stationary stable processes. We conclude with the unique decomposition in distribution of stationary stable processes into the sum of four major independent components: 1. A mixed moving average component. 2. A harmonizable (or ``trivial'') component. 3. A cyclic component 4. A component which is different from these.

Pipiras, V; Pipiras, Vladas; Taqqu, Murad S.

2004-01-01

86

Phase diagram and thermodynamics of oxidation-reduction processes of the MgO-V2O5-VO2 system  

International Nuclear Information System (INIS)

The phase diagram of the system MgO-V2O5-VO2 at 953 deg K is studied using the methods of X-ray phase and e.m.f. analysis. The thermodynamic characteristics are determined of the possible oxidation-reduction processes in the given system, hypovanadate MgVO3 and bronze MgV3O8. The phase diagram of oxide vanadium compounds of magnesium depending on the temperature and equilibrium oxygen pressure, is plotted

87

Automation of Feynman diagram evaluations  

International Nuclear Information System (INIS)

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

88

MAPMAN: a user-driven tool to display genomics data sets onto diagrams of metabolic pathways and other biological processes.  

Science.gov (United States)

MAPMAN is a user-driven tool that displays large data sets onto diagrams of metabolic pathways or other processes. SCAVENGER modules assign the measured parameters to hierarchical categories (formed 'BINs', 'subBINs'). A first build of TRANSCRIPTSCAVENGER groups genes on the Arabidopsis Affymetrix 22K array into >200 hierarchical categories, providing a breakdown of central metabolism (for several pathways, down to the single enzyme level), and an overview of secondary metabolism and cellular processes. METABOLITESCAVENGER groups hundreds of metabolites into pathways or groups of structurally related compounds. An IMAGEANNOTATOR module uses these groupings to organise and display experimental data sets onto diagrams of the users' choice. A modular structure allows users to edit existing categories, add new categories and develop SCAVENGER modules for other sorts of data. MAPMAN is used to analyse two sets of 22K Affymetrix arrays that investigate the response of Arabidopsis rosettes to low sugar: one investigates the response to a 6-h extension of the night, and the other compares wild-type Columbia-0 (Col-0) and the starchless pgm mutant (plastid phosphoglucomutase) at the end of the night. There were qualitatively similar responses in both treatments. Many genes involved in photosynthesis, nutrient acquisition, amino acid, nucleotide, lipid and cell wall synthesis, cell wall modification, and RNA and protein synthesis were repressed. Many genes assigned to amino acid, nucleotide, lipid and cell wall breakdown were induced. Changed expression of genes for trehalose metabolism point to a role for trehalose-6-phosphate (Tre6P) as a starvation signal. Widespread changes in the expression of genes encoding receptor kinases, transcription factors, components of signalling pathways, proteins involved in post-translational modification and turnover, and proteins involved in the synthesis and sensing of cytokinins, abscisic acid (ABA) and ethylene revealing large-scale rewiring of the regulatory network is an early response to sugar depletion. PMID:14996223

Thimm, Oliver; Bläsing, Oliver; Gibon, Yves; Nagel, Axel; Meyer, Svenja; Krüger, Peter; Selbig, Joachim; Müller, Lukas A; Rhee, Seung Y; Stitt, Mark

2004-03-01

89

Multiphase Flow Modeling of Biofuel Production Processes  

Energy Technology Data Exchange (ETDEWEB)

As part of the Idaho National Laboratory's (INL's) Secure Energy Initiative, the INL is performing research in areas that are vital to ensuring clean, secure energy supplies for the future. The INL Hybrid Energy Systems Testing (HYTEST) Laboratory is being established to develop and test hybrid energy systems with the principal objective to safeguard U.S. Energy Security by reducing dependence on foreign petroleum. HYTEST involves producing liquid fuels in a Hybrid Energy System (HES) by integrating carbon-based (i.e., bio-mass, oil-shale, etc.) with non-carbon based energy sources (i.e., wind energy, hydro, geothermal, nuclear, etc.). Advances in process development, control and modeling are the unifying vision for HES. This paper describes new modeling tools and methodologies to simulate advanced energy processes. Needs are emerging that require advanced computational modeling of multiphase reacting systems in the energy arena, driven by the 2007 Energy Independence and Security Act, which requires production of 36 billion gal/yr of biofuels by 2022, with 21 billion gal of this as advanced biofuels. Advanced biofuels derived from microalgal biomass have the potential to help achieve the 21 billion gal mandate, as well as reduce greenhouse gas emissions. Production of biofuels from microalgae is receiving considerable interest due to their potentially high oil yields (around 600 gal/acre). Microalgae have a high lipid content (up to 50%) and grow 10 to 100 times faster than terrestrial plants. The use of environmentally friendly alternatives to solvents and reagents commonly employed in reaction and phase separation processes is being explored. This is accomplished through the use of hydrothermal technologies, which are chemical and physical transformations in high-temperature (200-600 C), high-pressure (5-40 MPa) liquid or supercritical water. Figure 1 shows a simplified diagram of the production of biofuels from algae. Hydrothermal processing has significant advantages over other biomass processing methods with respect to separations. These 'green' alternatives employ a hybrid medium that, when operated supercritically, offers the prospect of tunable physicochemical properties. Solubility can be rapidly altered and phases partitioned selectively to precipitate or dissolve certain components by altering temperature or pressure in the near-critical region. The ability to tune the solvation properties of water in the highly compressible near-critical region facilitates partitioning of products or by-products into separate phases to separate and purify products. Since most challenges related to lipid extraction are associated with the industrial scale-up of integrated extraction systems, the new modeling capability offers the prospect of addressing previously untenable scaling issues.

D. Gaston; D. P. Guillen; J. Tester

2011-06-01

90

Application of ISO22000, failure mode, and effect analysis (FMEA) cause and effect diagrams and pareto in conjunction with HACCP and risk assessment for processing of pastry products.  

Science.gov (United States)

The Failure Mode and Effect Analysis (FMEA) model has been applied for the risk assessment of pastry processing. A tentative approach of FMEA application to the pastry industry was attempted in conjunction with ISO22000. Preliminary Hazard Analysis was used to analyze and predict the occurring failure modes in a food chain system (pastry processing plant), based on the functions, characteristics, and/or interactions of the ingredients or the processes, upon which the system depends. Critical Control points have been identified and implemented in the cause and effect diagram (also known as Ishikawa, tree diagram, and fishbone diagram). In this work a comparison of ISO22000 analysis with HACCP is carried out over pastry processing and packaging. However, the main emphasis was put on the quantification of risk assessment by determining the Risk Priority Number (RPN) per identified processing hazard. Storage of raw materials and storage of final products at -18°C followed by freezing were the processes identified as the ones with the highest RPN (225, 225, and 144 respectively) and corrective actions were undertaken. Following the application of corrective actions, a second calculation of RPN values was carried out leading to considerably lower values (below the upper acceptable limit of 130). It is noteworthy that the application of Ishikawa (Cause and Effect or Tree diagram) led to converging results thus corroborating the validity of conclusions derived from risk assessment and FMEA. Therefore, the incorporation of FMEA analysis within the ISO22000 system of a pastry processing industry is considered imperative. PMID:21838557

Varzakas, Theodoros H

2011-09-01

91

Multi-Particle Processes in the Standard Model without Feynman Diagrams  

CERN Document Server

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 3^n, 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.

Papadopoulos, C G; Papadopoulos, Costas G.; Worek, Malgorzata

2005-01-01

92

System studies in PA: Development of process influence diagram (PID) for SFR-1 repository near-field + far-field  

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

93

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

94

Application of quaternary phase diagrams to compound semiconductor processing. Progress report, April 1, 1988--December 31, 1988  

Energy Technology Data Exchange (ETDEWEB)

This paper considers the application of quaternary phase diagrams to understanding and predicting the behavior of II-VI thin film interfaces in photovoltaic devices under annealing conditions. Examples, listed in a table, include semiconductor/insulator/semiconductor (SIS) layered structures, II-VI/II-VI and III-V/II-VI epitaxial heterojunctions and oxidation of ternary compounds. Solid solubility is taken into account for quaternary phase diagrams of semiconductor systems. Using free energies of formation, a method to calculate the quaternary phase diagrams was developed. The Ga-As-II-VI and Cd-Te-Zn-O phase diagrams are reviewed as examples of quaternary phase diagrams without and with solid solubility.

Schwartzman, A.

1988-12-31

95

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.

96

Biological processes, properties and molecular wiring diagrams of candidate low-penetrance breast cancer susceptibility genes  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Recent advances in whole-genome association studies (WGASs for human cancer risk are beginning to provide the part lists of low-penetrance susceptibility genes. However, statistical analysis in these studies is complicated by the vast number of genetic variants examined and the weak effects observed, as a result of which constraints must be incorporated into the study design and analytical approach. In this scenario, biological attributes beyond the adjusted statistics generally receive little attention and, more importantly, the fundamental biological characteristics of low-penetrance susceptibility genes have yet to be determined. Methods We applied an integrative approach for identifying candidate low-penetrance breast cancer susceptibility genes, their characteristics and molecular networks through the analysis of diverse sources of biological evidence. Results First, examination of the distribution of Gene Ontology terms in ordered WGAS results identified asymmetrical distribution of Cell Communication and Cell Death processes linked to risk. Second, analysis of 11 different types of molecular or functional relationships in genomic and proteomic data sets defined the "omic" properties of candidate genes: i/ differential expression in tumors relative to normal tissue; ii/ somatic genomic copy number changes correlating with gene expression levels; iii/ differentially expressed across age at diagnosis; and iv/ expression changes after BRCA1 perturbation. Finally, network modeling of the effects of variants on germline gene expression showed higher connectivity than expected by chance between novel candidates and with known susceptibility genes, which supports functional relationships and provides mechanistic hypotheses of risk. Conclusion This study proposes that cell communication and cell death are major biological processes perturbed in risk of breast cancer conferred by low-penetrance variants, and defines the common omic properties, molecular interactions and possible functional effects of candidate genes and proteins.

Moreno Víctor

2008-12-01

97

Phase diagrams  

Energy Technology Data Exchange (ETDEWEB)

The description is presented of binary phase diagrams of titanium alloyed with the following elements: silver, aluminium, arsenic, gold, boron, barium, beryllium, bismuth, carbon, calcium, cadmium, cobalt, chromium, copper, iron, gallium, germanium, hydrogen, hafnium, indium, iridium, potassium, lithium, magnesium, manganese, molybdenum, nitrogen, sodium, niobium, nickel, oxygen, osmium, phosphorus, lead, palladium, platinum, plutonium, rhenium, lanthanium, cerium, preseodymium, neodymium, gadolinium, erbium, terbium, thulium, lutetium, rhodium, ruthenium, scandium, silicon, tin, strontium, tantalum, technetium, thorium, uranium, vanadium, tungsten, yttrium, ytterbium, zinc and zirconium.

Kubaschewski-von Goldbeck, O. (Technische Hochschule Aachen (Germany, F.R.). Lehrstuhl fuer Metallurgie der Kernbrennstoffe und Theoretische Huettenkunde)

1983-01-01

98

Phase diagrams  

International Nuclear Information System (INIS)

The description is presented of binary phase diagrams of titanium alloyed with the following elements: silver, aluminium, arsenic, gold, boron, barium, beryllium, bismuth, carbon, calcium, cadmium, cobalt, chromium, copper, iron, gallium, germanium, hydrogen, hafnium, indium, iridium, potassium, lithium, magnesium, manganese, molybdenum, nitrogen, sodium, niobium, nickel, oxygen, osmium, phosphorus, lead, palladium, platinum, plutonium, rhenium, lanthanium, cerium, preseodymium, neodymium, gadolinium, erbium, terbium, thulium, lutetium, rhodium, ruthenium, scandium, silicon, tin, strontium, tantalum, technetium, thorium, uranium, vanadium, tungsten, yttrium, ytterbium, zinc and zirconium

99

System studies in PA: Development of process influence diagram (PID) for SFR-1 repository near-field + far-field  

International Nuclear Information System (INIS)

ollowing 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

100

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

Science.gov (United States)

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

 
 
 
 
101

Stability Lobe Diagram for High Speed Machining Processes:Comparison of Experimental and Analytical Methods – A Review  

Directory of Open Access Journals (Sweden)

Full Text Available Chatter is a complicated problem faced by machine tool operators. Chatter is a self-excited vibration that can occur during machining operations. This is an undesirable phenomenon which limits the productivity of the machine. A lot of techniques have been developed to control the chatter. Stability lobe diagram is an effective tool which helps the operator to select specific spindle speeds during production to avoid chatter in machine. Stability lobes are plotted against axial depth of cut Vs spindle speed, which shows a boundary between stable and unstable cutting regions. Numerous experimental and analytical techniques have been developed to establish stability lobe diagram. This paper presents a review on experimental and analytical methods of obtaining stability lobe diagram in high speed milling operation.

PALPANDIAN P

2013-03-01

102

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...

Yeh-Chun Juan; Kuo-Yen Yuan

2013-01-01

103

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

104

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

105

Null flows, positive flows and the structure of stationary symmetric stable processes  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper elucidates the connection between stationary symmetric alpha-stable processes with 0flows on measure spaces by describing a new and unique decomposition of stationary stable processes into those corresponding to positive flows and those corresponding to null flows. We show that a necessary and sufficient for a stationary stable process to be ergodic is that its positive component vanishes.

Samorodnitsky, Gennady

2004-01-01

106

Waste identification diagrams  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The most popular and perhaps the most effective way to represent the material flow in production units is the diagram known as Value Stream Map (VSM). Moreover these maps are also used to help in the identification of waste as well as a tool to support continuous improvement. Nevertheless, many of VSM limitations are known and thus there is room for the creation of other more effective ways to represent productive units as well as helping the identification of production waste. This paper pre...

Sa?, Jose? Carlos; Carvalho, Dinis; Sousa, Rui M.

2011-01-01

107

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

108

Hydrogeomorphic processes in a steep debris flow initiation zone  

Science.gov (United States)

Many debris flows initiate in steep channels (>20 degrees), yet studies have focused on lower-gradient streams where failure is controlled by water height above channel deposits. Multiple debris flows in a steep channel in Ohya landslide, central Japan, were linked to infilling processes (i.e., freeze-thaw and dry ravel) and partial saturation of accumulated sediment. Because of very active geomorphic processes in this catchment, 39 debris flows were observed in the past 6 yr. Pre- and post event imagery indicates selective transport of finer materials during most debris flows that comprise saturated and unsaturated flows; however, fluvial sediment processes, important in relation to debris flow initiation in gentler channels, were minimal. Critical conditions for the movement of such unsaturated materials are derived by equating shear stress with solid friction of the channel bed.

Imaizumi, Fumitoshi; Sidle, Roy C.; Tsuchiya, Satoshi; Ohsaka, Okihiro

2006-05-01

109

IGDS/TRAP Interface Program (ITIP). Detailed Design Specification (DDS). [network flow diagrams for coal gasification studies  

Science.gov (United States)

The software modules which comprise the IGDS/TRAP Interface Program are described. A hierarchical input processing output (HIPO) chart for each user command is given. The description consists of: (1) function of the user command; (2) calling sequence; (3) moduls which call this use command; (4) modules called by this user command; (5) IGDS commands used by this user command; and (6) local usage of global registers. Each HIPO contains the principal functions performed within the module. Also included with each function are a list of the inputs which may be required to perform the function and a list of the outputs which may be created as a result of performing the function.

Jefferys, S.; Johnson, W.; Lewis, R.; Rich, R.

1981-01-01

110

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

111

Use of the method of partial pressure diagrams for thermodynamic description of the process of InAs preparation from gaseous phase  

International Nuclear Information System (INIS)

Gas-phase precipitation of InAs in order to obtain epitaxial films is carried out using interactions of gaseous (CH3)3In with AsH3, InCl with AsH3, InCl with AsCl3 and H2, and (CH3)3In with (CH3)3As and H2. The diagrams of partial pressures for four different processes of InAs precipitation depending on the pressure of the initial gaseous compounds are plotted. The (CH3)3In-(CH3)3As-H2 system has the largest InAs region

112

Tracer testing of processes under variable flow and volume  

International Nuclear Information System (INIS)

Continuous flow vessel system of pilot scale was constructed and provided computer control for programmed variation of flow rate and volume of liquid. Radioisotope and chemical tracers pulses were used for determination of residence time distributions (RTDs). It has been shown earlier that the RTDs of such vessels are invariable under variations of flow or volume of flow, if they are presented as a functions of an appropriate, integrated variable, and if the process flow pattern is not affected by the stated variations. The experimental responses of the individual vessels tested were therefore converted to RTD functions of such variable. In turned out that they converged close to each other within a wide range of steady states and dynamic variations of flow and volume. This is considered to indicate the expediency of the integrated variable used and invariance of the vessel flow pattern within the same range. Additional tests with continuous, randomly variable tracer feed support these conclusions. (author)

113

Automatized material and radioactivity flow control tool in decommissioning process  

International Nuclear Information System (INIS)

In this presentation the automatized material and radioactivity flow control tool in decommissioning process is discussed. It is concluded that: computer simulation of the decommissioning process is one of the important attributes of computer code Omega; one of the basic tools of computer optimisation of decommissioning waste processing are the tools of integral material and radioactivity flow; all the calculated parameters of materials are stored in each point of calculation process and they can be viewed; computer code Omega represents opened modular system, which can be improved; improvement of the module of optimisation of decommissioning waste processing will be performed in the frame of improvement of material procedures and scenarios.

114

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

Science.gov (United States)

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

115

True Phase Diagrams  

Science.gov (United States)

With the use of today's computer softwares, phase diagrams can readily be plotted with a wide choice of variables on the axes. Hillert defined a true phase diagram as a diagram where each point uniquely defines the stable phases. He also showed that not all choices of axis variables give true phase diagrams. In this note we will demonstrate that although the rules stated by Hillert are necessary they are not sufficient to have true phase diagrams.

Ågren, John; Schmid-Fetzer, Rainer

2014-10-01

116

Heat flow and geothermal processes in Iceland  

Science.gov (United States)

Heat flow values, derived from temperature measurements in shallow boreholes in Iceland, vary substantially across the country. The near-surface temperature gradients range from almost 0 to 500°C/km. The thermal conductivity of water-saturated rocks varies from 1.6 to 2.0 W/m°C. The temperature gradient in Iceland is mainly dependent on four factors: (1) the regional heat flow through the crust, (2) hydrothermal activity, (3) the permeability of the rock, and (4) residual heat in extinct volcanic centers. As Iceland is mainly made of basaltic material the radiogenic heat production is almost negligible. The thermal conductivity is, on the other hand, mainly influenced by the porosity of the rock; it increases as the porosity decreases. Iceland is made of sequences of flood basalts that formed within the volcanic rift zone—a continuation of the axis of the Mid-Atlantic ridge—and subsequently drifted sideways. Fresh basaltic lava is usually highly porous (30%) and fractured, and heat is mainly transported by convection. Therefore, a very low or even no temperature gradient is observed at shallow levels within the volcanic rift zone. As the basalt becomes buried the pores close due to lithostatic pressure and formation of secondary minerals. Below 500-1000 m depth in an uneroded lava pile, the heat is mainly transported by conduction. In the lowlands and valleys of Iceland outside the volcanic rift zone, 1000-1500 m of the original lava pile has been eroded, leaving thermal conduction as the most important heat transport mechanism. The regional temperature gradient has been measured in drillholes in dense and poorly permeable rocks away from the geothermal fields. The results show that the temperature gradient varies from 50 to 150°C/km. The highest values are found close to the volcanic rift zone and the gradient decreases with distance from the spreading axis. This result is mainly based on numerous shallow boreholes (60-500 m) but in some cases the results have been confirmed by 1000-2000 m deep boreholes. By extrapolating the temperature gradient down and assuming a slight increase in the thermal conductivity with depth, partially molten material can be expected at 10-30 km depth. Geothermal reservoirs are quite common in Iceland. They are primarily convective systems associated with young tectonic fractures, carrying heat from several kilometers depth towards the surface. Within the volcanic rift zone the heat sources seem to be hot intrusions; away from it, the heat is mined from the underlying crust. The highest values of the near-surface temperature gradient are found above the geothermal systems. Drilling of 30-60 m deep boreholes is therefore a powerful tool for geothermal prospecting outside the volcanic rift zone. In the deeper parts of the geothermal systems, a gentle temperature gradient is observed and the temperature is lower than would be expected from the regional temperature gradient. This is due to geothermal convection which has removed heat from the deeper parts of the geothermal systems. Convective geothermal systems must have a downflow part, where cold water is flowing down into the deeper parts of the geothermal systems along fractures. Such downflow areas have been observed and appear as areas with an anomalously low temperature gradient.

Flóvenz, Ólafur G.; Saemundsson, Kristján

1993-09-01

117

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

118

Space Based Multi-level Process Flow and Logistics Analysis  

Directory of Open Access Journals (Sweden)

Full Text Available In order to thoroughly promote the enterprise digital construction and meet the demand of production management, the space based multi-level process data organization model has been put forward. Firstly, according to the practical division situation of enterprise production space, the multi-level organization method of production space has been proposed. Then through analyzing the manufacturing process of the products in different space layers, the space based multi-level process flow idea has been presented. At the same time, the mathematical model and formalized expression of multi-level technological process have been established. Finally, the in-output material flow relationship between different levels process flow units has been analyzed and the source of input object as well as the disposition of the output object of various level process flow units has been put into detailed analysis. At the mean time, particular statistical sum and trace arithmetic are provided so as to profoundly illustrate the essence of manufacturing process in theory. As a result, the models proposed in this study are not only express the manufacturing process flow of the product in an intuitive and clear way, but also satisfy all types of demands of production management.

Zhou Qiu-Zhong

2013-01-01

119

Forming Limit Diagrams of Zircaloy-4 and Zirlo Sheets for Stamping Process of Spacer Grids of Nuclear Fuel Rod  

Science.gov (United States)

We investigated the theoretical forming limit models for Zircaloy-4 and Zirlo used for spacer grid of nuclear fuel rods. Tensile tests were performed to obtain stress-strain curves and anisotropic coefficients, such as r-values. The experimental forming limit diagrams (FLD) for two materials were obtained by dome stretching tests following the specification of NUMISHEET 96. Theoretical FLD depends on forming limit model and yield criterion. To obtain the right hand side of FLD, we applied the forming limit models (Swift's diffuse necking, Marciniak-Kuczynski damage defect, Storen-Rice's vertex theory) to Zircaloy-4 and Zirlo sheets. Hill's local necking theory was adopted for the left side of FLD. To consider the anisotropy of sheets, the yield criteria of Hill (1948) and Hosford (1979) were applied. Comparing the predicted curves with the experimental data, we found that the FLD for Zircaloy-4 can be described by the Swift model with the Hill 48 yield criterion, while the FLD for Zirlo can be explained by the Storen-Rice model and the Hosford yield criterion (a = 8).

Seo, Yunmi; Hyun, Hong Chul; Lee, Hyungyil; Kim, Naksoo

2011-08-01

120

Numerical modelling of multiphase flow and transport processes in landfills.  

Science.gov (United States)

Waste material in municipal landfills can be described as heterogeneous porous media, where flow and transport processes of gases and liquids are combined with local material degradation. This paper deals with the basic formulation of a multiphase flow and transport model applicable to the numerical analysis of coupled transport and reaction processes inside landfills. The transport model treats landfills within the framework of continuum mechanics, where flow and transport processes are described on a macroscopic level. The composition of organic and inorganic matter in the solid phase and its degradation are modelled on a microscopic scale. The degradation model captures the different reaction schemes of various microbial activities. Subsequently, transport and reaction processes have to be coupled, since emissions at the surface and from the drainage layer depend on the flow of leachate and gas, the transport of various substances and heat, and the biodegradation of organic matter. The theoretical considerations presented here are fundamental to the development of numerical models for the simulation of multiphase flow and transport processes inside landfills coupled with biochemical reactions and heat generation. The implicit modelling of leachate and gas flows including growth and decay of micro-organisms are innovative contributions to landfill modelling PMID:16941996

Kindlein, Jonatham; Dinkler, Dieter; Ahrens, Hermann

2006-08-01

 
 
 
 
121

Recent Results in Ring-Diagram Analysis  

Science.gov (United States)

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

122

Establishment of pseudoternary LiO0.5-NiO-MnO2 phase diagram by combinatorial wet process.  

Science.gov (United States)

A pseudoternary LiO0.5-NiO-MnO2 reaction phase diagram was established using a combinatorial high-throughput materials exploration process to find candidate electrode materials for lithium ion secondary batteries. Each powder library was prepared using our combinatorial wet process based on the electrostatic spray deposition method and results obtained at various firing temperatures in an air atmosphere and an oxide atmosphere. In the air atmosphere, newly composed single phase regions of a layered rock salt-type structure were only found around Li2MnO3 at 800 °C. On the other hand, in the oxide atmosphere, most of the powder library showed the multiphase of the spinel and layered rock salt type structure. PMID:24171655

Fujimoto, Kenjiro; Shimura, Yosuke; Ito, Shigeru

2013-12-01

123

Diagramming Complex Activities  

DEFF Research Database (Denmark)

We increasingly live in heterogeneous ever-changing webs of activities where human actions are intertwined with events created by automatic machines.  In order to make such webs understandable to its human participants, their structure should be represented by displays emphasizing their action aspect. The paper suggests thematic roles as a semantics for actions, argues that a selection of well-known diagramming techniques can be defined within this theory, and uses the theory to discuss new issues related to process control and mobile technology.

Andersen, Peter BØgh

2005-01-01

124

EtherNet/IP coriolis flow measurement for process applications  

Energy Technology Data Exchange (ETDEWEB)

The first process automation vendor to launch Ethernet/IP as a digital output was Endress + Hauser. The product was introduced for their Promass Coriolis mass flow meter product line. This paper presents the Ethernet/IP Coriolis flow measurement for process applications. The Ethernet/IP minimizes device complexity and enables a plant to integrate their Coriolis flow meters into existing Rockwell automation logix environments flawlessly. Ethernet/IP allows multiple process variables and device conditions to be converted to user control points. It has speeds of up to 100 mbps and is the world's fastest digital protocol. It is an open standard form of unmodified Ethernet that is well known to users. Results showed that Promass 83 demonstrated superior accuracy in competitive field trials. The customer results included 40% reduction in device commissioning and a 25% reduction in loop identification, device integration and process loop tuning.

NONE

2011-11-15

125

A Conductivity Relationship for Steady-state Unsaturated Flow Processes under Optimal Flow Conditions  

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

126

Rotating Thermal Flows in Natural and Industrial Processes  

CERN Document Server

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

127

Modeling a novel glass immobilization waste treatment process using flow  

International Nuclear Information System (INIS)

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

128

Extrinsic Curvature Embedding Diagrams  

CERN Document Server

Embedding diagrams have been used extensively to visualize the properties of curved space in Relativity. We introduce a new kind of embedding diagram based on the {\\it extrinsic} curvature (instead of the intrinsic curvature). Such an extrinsic curvature embedding diagram, when used together with the usual kind of intrinsic curvature embedding diagram, carries the information of how a surface is {\\it embedded} in the higher dimensional curved space. Simple examples are given to illustrate the idea.

Lu, J L

2003-01-01

129

AFM Diagram Quiz  

Science.gov (United States)

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

130

Flow manipulation and control methodologies for vacuum infusion processes  

Science.gov (United States)

Vacuum Infusion Processes (VIPs) are very attractive composite manufacturing processes since large structures such as fuselages and wind blades can be fabricated in a cost effective manner. In VIPs, the fabric layers are placed on a one sided mold which is closed by enveloping the entire mold with a thin plastic film and evacuating the air out. The vacuum compresses the fabric and when a resin inlet is opened, resin flows into the mold. The resin is allowed to cure before demolding the structure. However, VIPs causes non-repeatable and problematic resin filling patterns due to the heterogeneous nature of the material, nesting between various layers, and the hand labor utilized for laying up the fabric. The design of the manufacturing process routinely involves a trial and error model which make manufacturing costs and development time difficult to estimate. The clear solution to improving the reliability and robustness of VIPs is to implement a system capable of on-line flow control. While on-line flow control has been studied and developed for other composite manufacturing processes, the VIPs have been largely ignored as there are few process parameters that lend themselves to effective flow control. In this work, two new processes were discovered with the goal of on-line control of VIPs in mind. These two processes referred to as Flow Flooding Chamber (FFC) and Vacuum Induced Preform Relaxation (VIPR) will be discussed. They both employ an external vacuum chamber to influence the permeability of the fabric temporarily which allows one to redirect the resin flow to resin starved regions of the mold. The VIPR process in addition uses a low and regulated vacuum pressure in the external chamber to increase the permeability of the fabric in a controllable manner. The objective is to understand how the VIPR process affects the resin flow in order to implement it into a complete flow control and automated environment which will reduce or eliminate the variability experienced. First, the effect on permeability is characterized, so the process can be simulated and the flow front patterns can be predicted. It was found that using the VIPR process in combination with tool side injection gates is a very effective method to control resin flow. Based on this understanding several control algorithms were developed to use the process in an automated manufacturing environment which were tested and validated in a virtual environment. To implement and demonstrate the approach, an experimental workstation was built and various infusion examples were performed in the automated environment to validate the capability of the VIPR process with the control methodologies. The VIPR process with control consistently performed better than the process without control. This contribution should prove useful in making VIPs more reliable in the production of large scale composite structures.

Alms, Justin B.

131

Krohne Flow Indicator and High Flow Alarm Local Indicator and High Flow Alarm of Helium Flow from the SCHe Purge Lines C and D to the Process Vent  

Energy Technology Data Exchange (ETDEWEB)

Flow Indicators/alarms FI/FSH-5*52 and -5*72 are located in the process vent lines connected to the 2 psig SCHe purge lines C and D. They monitor the flow from the 2 psig SCHe purge going to the process vent. The switch/alarm is non-safety class GS.

MISKA, C.R.

2000-09-03

132

TV Trouble-Shooting Manual. Volumes 3-4. Part 1: Block Diagram of Colour TV Receiver and Signal Flow. Student and Instructor's Manuals.  

Science.gov (United States)

These volumes are, respectively, the self-instructional student manual and the teacher manual that cover the first set of training topics in this course for television repair technicians. Both volumes contain the following two sections: (1) Functional Block Diagram of a Colour TV Receiver, including information on the video reproduction circuit,…

Mukai, Masaaki; Kobayashi, Ryozo

133

Digital image processing based mass flow rate measurement of gas/solid two-phase flow  

Energy Technology Data Exchange (ETDEWEB)

With the rapid growth of the process industry, pneumatic conveying as a tool for the transportation of a wide variety of pulverized and granular materials has become widespread. In order to improve plant control and operational efficiency, it is essential to know the parameters of the particle flow. This paper presents a digital imaging based method which is capable of measuring multiple flow parameters, including volumetric concentration, velocity and mass flow rate of particles in the gas/solid two phase flow. The measurement system consists of a solid state laser for illumination, a low-cost CCD camera for particle image acquisition and a microcomputer with bespoke software for particle image processing. The measurements of particle velocity and volumetric concentration share the same sensing hardware but use different exposure time and different image processing methods. By controlling the exposure time of the camera a clear image and a motion blurred image are obtained respectively. The clear image is thresholded by OTSU method to identify the particles from the dark background so that the volumetric concentration is determined by calculating the ratio between the particle area and the total area. Particle velocity is derived from the motion blur length, which is estimated from the motion blurred images by using the travelling wave equation method. The mass flow rate of particles is calculated by combining the particle velocity and volumetric concentration. Simulation and experiment results indicate that the proposed method is promising for the measurement of multiple parameters of gas/solid two-phase flow.

Song Ding; Peng Lihui; Lu Geng; Yang Shiyuan [Tsinghua National Laboratory for Information Science and Technology, Department of Automation, Tsinghua University, Beijing, 100084 (China); Yan Yong, E-mail: lihuipeng@tsinghua.edu.c [University of Kent, Canterbury, Kent CT2 7NT (United Kingdom)

2009-02-01

134

Development of databases and generation of stability diagrams pertaining to the modelling of processes during hot corrosion of heat exchanger components  

Energy Technology Data Exchange (ETDEWEB)

The purpose of the project ''Optimisation of In-Service Performance of Boiler Steels by Modelling High Temperature Corrosion'' (G5RD-CT-2001-00593, acronym OptiCorr) was to establish a set of focused procedures, both in terms of applications of thermochemical standard software and in terms of dedicated new developments, which enable a user to investigate the behaviour of boiler components based on the application of rigorous thermodynamics. Thermodynamic databases which cover the materials involved had to be compiled and assessed in order to be able to apply the appropriate software. Particular new results coming from the databases work will be highlighted. The results of phase equilibrium calculations are shown in appropriate diagrams and compared with published experimental data. The thermochemical standard software FactSage permits the investigation of stoichiometric reactions, complex equilibria and phase diagrams. These calculational capabilities have been applied for the purposes of investigation of (1) the composition of complex combustion gases, (2) metal-gas interactions and (3) metal-gas-molten salt interactions, since these have been established to be the key points for the understanding of the corrosion of heat exchanger components. Selected results from these calculations will be demonstrated and discussed. Application specific software has been developed using the approach of local chemical equilibrium calculated by the programmer's library ChemApp and the add-in ChemSheet for Microsoft EXCEL trademark. Two key processes have been treated: The internal corrosion of the metallic material by diffusion of gases and metals and local phase formation as well as the corrosion of heat exchanger material under a molten salt layer which is in contact with an outer gas phase. The general principles of the code development will be outlined while the details of the programs are given in separate presentations in this volume. (Abstract Copyright [2006], Wiley Periodicals, Inc.)

Hack, K.; Jantzen, T. [GTT-Technologies, Kaiserstrasse 100, D-52134 Herzogenrath (Germany)

2006-03-15

135

Functional correlates of optic flow motion processing in Parkinson's disease.  

Science.gov (United States)

The visual input created by the relative motion between an individual and the environment, also called optic flow, influences the sense of self-motion, postural orientation, veering of gait, and visuospatial cognition. An optic flow network comprising visual motion areas V6, V3A, and MT+, as well as visuo-vestibular areas including posterior insula vestibular cortex (PIVC) and cingulate sulcus visual area (CSv), has been described as uniquely selective for parsing egomotion depth cues in humans. Individuals with Parkinson's disease (PD) have known behavioral deficits in optic flow perception and visuospatial cognition compared to age- and education-matched control adults (MC). The present study used functional magnetic resonance imaging (fMRI) to investigate neural correlates related to impaired optic flow perception in PD. We conducted fMRI on 40 non-demented participants (23 PD and 17 MC) during passive viewing of simulated optic flow motion and random motion. We hypothesized that compared to the MC group, PD participants would show abnormal neural activity in regions comprising this optic flow network. MC participants showed robust activation across all regions in the optic flow network, consistent with studies in young adults, suggesting intact optic flow perception at the neural level in healthy aging. PD participants showed diminished activity compared to MC particularly within visual motion area MT+ and the visuo-vestibular region CSv. Further, activation in visuo-vestibular region CSv was associated with disease severity. These findings suggest that behavioral reports of impaired optic flow perception and visuospatial performance may be a result of impaired neural processing within visual motion and visuo-vestibular regions in PD. PMID:25071484

Putcha, Deepti; Ross, Robert S; Rosen, Maya L; Norton, Daniel J; Cronin-Golomb, Alice; Somers, David C; Stern, Chantal E

2014-01-01

136

Functional correlates of optic flow motion processing in Parkinson's disease  

Science.gov (United States)

The visual input created by the relative motion between an individual and the environment, also called optic flow, influences the sense of self-motion, postural orientation, veering of gait, and visuospatial cognition. An optic flow network comprising visual motion areas V6, V3A, and MT+, as well as visuo-vestibular areas including posterior insula vestibular cortex (PIVC) and cingulate sulcus visual area (CSv), has been described as uniquely selective for parsing egomotion depth cues in humans. Individuals with Parkinson’s disease (PD) have known behavioral deficits in optic flow perception and visuospatial cognition compared to age- and education-matched control adults (MC). The present study used functional magnetic resonance imaging (fMRI) to investigate neural correlates related to impaired optic flow perception in PD. We conducted fMRI on 40 non-demented participants (23 PD and 17 MC) during passive viewing of simulated optic flow motion and random motion. We hypothesized that compared to the MC group, PD participants would show abnormal neural activity in regions comprising this optic flow network. MC participants showed robust activation across all regions in the optic flow network, consistent with studies in young adults, suggesting intact optic flow perception at the neural level in healthy aging. PD participants showed diminished activity compared to MC particularly within visual motion area MT+ and the visuo-vestibular region CSv. Further, activation in visuo-vestibular region CSv was associated with disease severity. These findings suggest that behavioral reports of impaired optic flow perception and visuospatial performance may be a result of impaired neural processing within visual motion and visuo-vestibular regions in PD. PMID:25071484

Putcha, Deepti; Ross, Robert S.; Rosen, Maya L.; Norton, Daniel J.; Cronin-Golomb, Alice; Somers, David C.; Stern, Chantal E.

2014-01-01

137

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, it demonstrates some of the challenges and opportunities of working with coaching in a systematic way across broader initiatives in organizations.

Skytte GØrtz, Kim Erik

2008-01-01

138

Features, Events, and Processes in UZ Flow and Transport  

Energy Technology Data Exchange (ETDEWEB)

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 M&O 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.

J.E. Houseworth

2001-04-10

139

Steady flow approximations to the helium r-process  

Science.gov (United States)

A steady flow approximation to the r-process is presented and used for numerical experiments with physical quantities to determine the sensitivity of the process to variations in those quantities. The effect of neutron capture cross sections along the capture path and of recently available improved beta decay rates on the r-process are discussed. The peaks in the observed r-process yield curve near mass numbers 80 and 130 are roughly characterized by a neutron number density of 10 to the 20th per cu/cm; the mean beta decay rates are about 10/s, and the freezing time is comparable to or less than 0.1 s. The peak near mass number 195 is roughly characterized by a neutron number density of 10 to the 21st/cm, the mean beta decay rates are about 100/s, and the freezing time is comparable to or less than 0.01 s. The flow path of the steady state r-process is sensitively dependent upon the neutron capture cross sections in the flow network and on the values of the beta decay rates.

Cameron, A. G. W.; Cowan, J. J.; Klapdor, H. V.; Metzinger, J.; Oda, T.; Truran, J. W.

1983-01-01

140

Transition rate diagrams - A new approach to the study of selective excitation processes: The spectrum of manganese in a Grimm-type glow discharge  

Science.gov (United States)

The emission spectra of manganese observed using a Grimm-type glow discharge in pure argon, argon with 0.3% v/v hydrogen and pure neon were studied in order to identify major excitation and ionization processes of manganese in the plasma. A new procedure is proposed, in which each observed emission line is associated with the corresponding transition between different states of the Mn atom or Mn ion, and, by considering all the observed transitions from and into a specific state, a measure of the total rate is determined at which this state is radiatively populated and depopulated. These resulting population/depopulation rates are then plotted as function of level energy. Such plots, called here “transition rate diagrams”, show the role of individual states in the formation of the observed spectrum and can be used to identify possible selective excitation processes. Also, cascade excitation by radiative decay of higher excited states can be conveniently evaluated in this way. A detailed description of the observed Mn I and Mn II spectra is given for Ar, Ar-H2 and Ne plasmas and relevant excitation/ionization mechanisms are discussed. Matrix effects in analysis of manganese by glow discharge spectroscopy are discussed. A list of important Mn I and Mn II lines excited in the glow discharge plasma is given.

Weiss, Zden?k; Steers, Edward B. M.; Pickering, Juliet C.; Mushtaq, Sohail

2014-02-01

 
 
 
 
141

Braided chord diagrams  

CERN Document Server

The notion of a braided chord diagram is introduced and studied. An equivalence relation is given which identifies all braidings of a fixed chord diagram. It is shown that finite-type invariants are stratified by braid index for knots which can be represented as closed 3-braids. Partial results are obtained about spanning sets for the algebra of chord diagrams of braid index 3.

Birman, J S; Birman, Joan S.; Trapp, Rolland

1998-01-01

142

Sewer system flow components identification using signal processing.  

Science.gov (United States)

The development of a continuous model to simulate the behaviour of sewer systems requires detailed information on each component of the flows contributing to the global discharge. In this paper authors investigate a novel method based on signal processing and long time series data implemented with a 2 min time step (flow rate, conductivity, pH and turbidity) in order to identify the dry weather components in a separated stormwater sewer system draining an industrial catchment. The wavelet analysis is applied to the recorded data to identify main components in dry weather flow after the removing of the signal noise. This paper highlights also a method to detect inflow into sewer system and shows how hydrological modelling can be used to characterise the relevant components. These techniques could be used as a basis for several applications. PMID:20595760

Dorval, F A; Chocat, B; Emmanuel, E; Lipeme Kouyi, G

2010-01-01

143

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)

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.

SchrØder, Thomas Morville; HØgh Jensen, Karsten

1999-01-01

145

Evaluation of the MODFLOW-2005 Conduit Flow Process.  

Science.gov (United States)

The recent development of the Conduit Flow Process (CFP) by the U.S. Geological Survey (USGS) provides hydrogeologic modelers with a new tool that incorporates the non-Darcian, multiporosity components of flow characteristic of karst aquifers. CFP introduces new parameters extending beyond those of traditional Darcian groundwater flow codes. We characterize a karst aquifer to collect data useful for evaluating this new tool at a test site in west-central Florida, where the spatial distribution and cross-sectional area of the conduit network are available. Specifically, we characterize: (1) the potential for Darcian/non-Darcian flow using estimates of specific discharge vs. observed hydraulic gradients, and (2) the temporal variation for the direction and magnitude of fluid exchange between the matrix and conduit network during extreme hydrologic events. We evaluate the performance of CFP Mode 1 using a site-scale dual-porosity model and compare its performance with a comparable laminar equivalent continuum model (ECM) using MODFLOW-2005. Based on our preliminary analyses, hydraulic conductivity coupled with conduit wall conductance improved the match between observed and simulated discharges by 12% to 40% over turbulent flow alone (less than 1%). PMID:20113361

Hill, Melissa E; Stewart, Mark T; Martin, Angel

2010-01-01

146

Restricted Exclusion Processes without Particle Conservation Flows to Directed Percolation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Absorbing phase transition in restricted exclusion processes are characterized by simple integer exponents. We show that this critical behaviour flows to the directed percolation (DP) universality class when particle conservation is broken suitably. The same transition, when studied using the average density as the controlling parameter, yields critical exponents quite different from DP; we argue that these exponents are actually related to DP by a scaling factor $1/\\beta_{D...

Basu, Urna; Mohanty, P. K.

2012-01-01

147

Process monitoring and flow ELISA techniques in biotechnology  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The first chapter of this thesis describes an automated system for rapid on-line process monitoring and harvesting of monoclonal antibody produced in a fermentor. Antibody production was monitored for the first 60 hours. When production reached a plateau, harvesting was initiated, which took 90 hours to complete.^ The following two chapters discuss a flow ELISA methodology for quantitation of mIgG developed in: (i) a bed packed perfusion chromatography media and (ii) a fused silica capilla...

Zhang, Jifeng

1996-01-01

148

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...

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

2013-01-01

149

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

150

Diagrams for quantum oscillators  

International Nuclear Information System (INIS)

Diagrams are constructed for matrix elements associated with perturbed harmonic oscillators in quantum mechanics. The diagrams are shown to enable efficient computation of energy shifts and transmission probabilities. An intuitive approach to the diagrammatic technique is used so that introductory quantum courses can incorporate the methods presented

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 Navier–Stokes (RANS) equationswith two-equation k?? 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 water–sand mixture, (3) boundary layer streaming due to convective terms, and (4) converging–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.; SchlØer, Signe

2013-01-01

153

How to Interpret Circuit Diagrams  

Science.gov (United States)

This site presents an explanation of how to interpret circuit diagrams. Two diagrams show the difference between a "short hand" circuit diagram and a more detailed one. The detailed circuit diagram is useful for those first learning circuits in an effort to eventually understand the "short hand" diagram without difficulty.

Lesurf, Jim

2013-06-07

154

Low resource processing algorithms for laser Doppler blood flow imaging.  

Science.gov (United States)

The emergence of full field laser Doppler blood flow imaging systems based on CMOS camera technology means that a large amount of data from each pixel in the image needs to be processed rapidly and system resources need to be used efficiently. Conventional processing algorithms that are utilized in single point or scanning systems are therefore not an ideal solution as they will consume too much system resource. Two processing algorithms that address this problem are described and efficiently implemented in a field programmable gate array. The algorithms are simple enough to use low system resource but effective enough to produce accurate flow measurements. This enables the processing unit to be integrated entirely in an embedded system, such as in an application-specific integrated circuit. The first algorithm uses a short Fourier transformation length (typically 8) but averages the output multiple times (typically 128). The second method utilizes an infinite impulse response filter with a low number of filter coefficients that operates in the time domain and has a frequency-weighted response. The algorithms compare favorably with the reference standard 1024 point fast Fourier transform in terms of both resource usage and accuracy. The number of data words per pixel that need to be stored for the algorithms is 1024 for the reference standard, 8 for the short length Fourier transform algorithm and 5 for the algorithm based on the infinite impulse response filter. Compared to the reference standard the error in the flow calculation is 1.3% for the short length Fourier transform algorithm and 0.7% for the algorithm based on the infinite impulse response filter. PMID:21316289

Nguyen, Hoang C; Hayes-Gill, Barrie R; Zhu, Yiqun; Crowe, John A; He, Diwei; Morgan, Stephen P

2011-07-01

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

Analysis of stochastic characteristics of the Benue River flow process  

Science.gov (United States)

Stochastic characteristics of the Benue River streamflow process are examined under conditions of data austerity. The streamflow process is investigated for trend, non-stationarity and seasonality for a time period of 26 years. Results of trend analyses with Mann-Kendall test show that there is no trend in the annual mean discharges. Monthly flow series examined with seasonal Kendall test indicate the presence of positive change in the trend for some months, especially the months of August, January, and February. For the stationarity test, daily and monthly flow series appear to be stationary whereas at 1%, 5%, and 10% significant levels, the stationarity alternative hypothesis is rejected for the annual flow series. Though monthly flow appears to be stationary going by this test, because of high seasonality, it could be said to exhibit periodic stationarity based on the seasonality analysis. The following conclusions are drawn: (1) There is seasonality in both the mean and variance with unimodal distribution. (2) Days with high mean also have high variance. (3) Skewness coefficients for the months within the dry season period are greater than those of the wet season period, and seasonal autocorrelations for streamflow during dry season are generally larger than those of the wet season. Precisely, they are significantly different for most of the months. (4) The autocorrelation functions estimated “over time” are greater in the absolute value for data that have not been deseasonalised but were initially normalised by logarithmic transformation only, while autocorrelation functions for i = 1, 2, ..., 365 estimated “over realisations” have their coefficients significantly different from other coefficients.

Otache, Martins Y.; Bakir, Mohammad; Li, Zhijia

2008-05-01

157

Subcellular mapping of dendritic activity in optic flow processing neurons.  

Science.gov (United States)

Dendritic integration is a fundamental element of neuronal information processing. So far, few studies have provided a detailed spatial picture of this process, describing the properties of local dendritic activity and its subcellular organization. Here, we used 2-photon calcium imaging in optic flow processing neurons of the fly Calliphora vicina to determine the preferred location and direction of local motion cues for small branchlets throughout the entire dendrite. We found a pronounced retinotopic mapping on both the subcellular and the cell population level. In addition, dendritic branchlets residing in different layers of the neuropil were tuned to distinct directions of motion. Summing the local receptive fields of all dendritic branchlets reproduced the characteristic properties of these neurons' axonal output receptive fields. Our results corroborate the notion that the dendritic morphology of vertical system cells allows them to selectively collect local motion inputs with particular directional preferences from a spatially organized input repertoire, thus forming filters that match global patterns of optic flow. Furthermore, we suggest that the facet arrangement across the fly's eye shapes the subcellular direction tuning to local motion stimuli. These data illustrate a highly structured circuit organization as an efficient way to hard-wire a complex sensory task. PMID:24647929

Hopp, Elisabeth; Borst, Alexander; Haag, Juergen

2014-05-01

158

Photogrammetric and image processing aspects in quantitative flow visualization.  

Science.gov (United States)

The development of a measurement system for the visualization, topological classification, and quantitative analysis of complex flows in large-scale wind tunnel experiments is described. A new approach was sought in which the topological features of the flow (e.g., stream lines, separation and reattachment regions, stagnation points, and vortex lines) were extracted directly and preferably visualized in real-time in a virtual wind tunnel environment. The system was based on a stereo arrangement of two CCD cameras. A frame rate of 120 fps allowed measurements at high flow velocities. The paper focuses on the problem of fast and accurate reconstruction of path lines of helium filled soap bubbles in three dimensions (3D). A series of simple algorithmic steps was employed to ensure fast data processing. These included fast image segmentation, a spline approximation of the path lines, a camera model, point correspondence building, calculation of path line points in 3D and creation of a three-dimensional spline representation. The path lines, which contained both velocity and topological information, were analyzed to extract the relevant information. PMID:12495995

Machacek, Matthias; Rosgen, Thomas

2002-10-01

159

Modelling of scattering diagrams  

International Nuclear Information System (INIS)

Scattering methods are most suitable for studying the structure of unknown systems. Especially colloidal objects are of interest for both fundamental and applied science. Therefore an enormous amount of work has been done to extract structure information of such systems out of scattering diagrams. In particular the correlation between the structure of colloidal systems and the scattering diagrams is not fully understood yet. To gain more insight into this topic we numerically calculated scattering diagrams of simple colloidal objects. In general experimental samples exhibit a significant polydispersity. In models, however, one usually assumes monodisperse particles. Consequently, we investigated the influence of a polydisperse distribution of diameters on scattering diagrams to determine the validity of the analysis. (orig.)

160

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

 
 
 
 
161

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°. 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

162

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

163

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

164

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

165

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

166

Phase diagrams of self-organizing maps  

Science.gov (United States)

We present a method which allows the analytic determination of phase diagrams in the self-organizing map, a model for the formation of topographic projection patterns in the brain and in signal processing applications. The method only requires an ansatz for the tesselation of the data space induced by the map, not for the explicit state of the map. We analytically obtain phase diagrams for various examples, including models for the development of orientation and ocular-dominance maps. The latter phase diagram exhibits transitions to broadening ocular-dominance patterns as observed in a recent experiment.

Bauer, H.-U.; Riesenhuber, M.; Geisel, T.

1996-09-01

167

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.

168

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

169

Analysis of deposition process of solid solutions of the composition Gasub(1-y)Insub(y)Assub(1-x)Psub(x) from gaseous phase using partial pressure diagram method  

International Nuclear Information System (INIS)

The partial pressure diagrams, describing the process of epitaxial deposition of solid solutions of the composiiton Gasub(1-y)Insub(y)Assub(1-x)Psub(x) (0.2 <= x <= 1.0; 01. <= y <= 0.9) from gaseous phase according to chloride-hydride technology at 1000 K, are constructed. It is shown, that the value of the solid solution crystallization range monotonely changes, depending on x, y and psub(HCl) in the system

170

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

171

Upgrading Diagnostic Diagrams  

Science.gov (United States)

Diagnostic diagrams of forbidden lines have been a useful tool for observers in astrophysics for many decades now. They are used to obtain information on the basic physical properties of thin gaseous nebulae. Moreover they are also the initial tool to derive thermodynamic properties of the plasma from observations to get ionization correction factors and thus to obtain proper abundances of the nebulae. Some diagnostic diagrams are in wavelengths domains which were difficult to take either due to missing wavelength coverage or low resolution of older spectrographs. Thus they were hardly used in the past. An upgrade of this useful tool is necessary because most of the diagrams were calculated using only the species involved as a single atom gas, although several are affected by well-known fluorescence mechanisms as well. Additionally the atomic data have improved up to the present time. The new diagnostic diagrams are calculated by using large grids of parameter space in the photoionization code CLOUDY. For a given basic parameter the input radiation field is varied to find the solutions with cooling-heating-equilibrium. Empirical numerical functions are fitted to provide formulas usable in e.g. data reduction pipelines. The resulting diagrams differ significantly from those used up to now and will improve the thermodynamic calculations.

Proxauf, B.; Kimeswenger, S.; Öttl, S.

2014-04-01

172

Features, Events, and Processes in SZ Flow and Transport  

Energy Technology Data Exchange (ETDEWEB)

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).

S. Kuzio

2005-08-20

173

Features, Events, and Processes in SZ Flow and Transport  

Energy Technology Data Exchange (ETDEWEB)

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).

K. Economy

2004-11-16

174

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)

175

Manufacturing process planning optimisation in reconfigurable multiple parts flow lines  

Directory of Open Access Journals (Sweden)

Full Text Available Purpose: This paper explores the capabilities of genetic algorithms in handling optimization of the criticalissues mentioned above for the purpose of manufacturing process planning in reconfigurable manufacturingactivities. Two modified genetic algorithms are devised and employed to provide the best approximate processplanning solution. Modifications included adapting genetic operators to the problem specific knowledge andimplementing application specific heuristics to enhance the search efficiency.Design/methodology/approach: The genetic algorithm methodology implements a genetic algorithmthat is augmented by application specific heuristics in order to guide the search for an optimal solution.The case study is based on the manufacturing system. Raw materials enter the system through an input stageand exit the system through an output stage. The system is composed of sixteen (16 processing modulesthat are arranged in four processing stages.Findings: The results indicate that the two genetic algorithms are able to converge to optimal solutionsin reasonable time. A computational study shows that improved solutions can be obtained by implementinga genetic algorithm with an extended diversity control mechanism.Research limitations/implications: This paper has examined the issues of MPP optimization in a reconfigurablemanufacturing framework with the help of a reconfigurable multiparts manufacturing flow line.Originality/value: The results of the case illustration have demonstrated the practical use of diversity controlimplemented in the MGATO technique. In comparison to MGAWTO, the implemented MGATO improves thepopulation diversity through a customized threshold operator. It was clear that the MGATO can obtain bettersolution quality by foiling the tendency towards premature convergence.

N. Ismail

2008-12-01

176

29 CFR 1926.64 - Process safety management of highly hazardous chemicals.  

Science.gov (United States)

...10544-72-6 250 Nitrogen Trifluoride 7783-54-2 5000 Nitrogen Trioxide 10544-73-7...64—Block Flow Diagram and Simplified Process...P&Ids or other diagrams useful to the information...topics such as two phase flow for...

2010-07-01

177

29 CFR 1910.119 - Process safety management of highly hazardous chemicals.  

Science.gov (United States)

...10544-72-6 250 Nitrogen Trifluoride 7783-54-2 5000 Nitrogen Trioxide 10544-73-7...119—Block Flow Diagram and Simplified Process...P&IDs or other diagrams useful to the information...topics such as two phase flow for...

2010-07-01

178

Minkowski Diagram Model  

Science.gov (United States)

The Minkowski Diagram model displays the spacetime diagrams for two inertial observers. One or two events may be displayed and moved with the mouse. Optionally, the corresponding light cones may be shown, as well as the simultaneity lines in both reference frames. The spacetime interval is automatically computed. The simulation may be used to discuss simultaneity and causality in special relativity. You can modify this simulation if you have Ejs installed by right-clicking within the plot and selecting "Open Ejs Model" from the pop-up menu item. The Minkowski Diagram model was created using the Easy Java Simulations (Ejs) modeling tool. It is distributed as a ready-to-run (compiled) Java archive. Double clicking the ejs_ehu_special_relativity_minkowski.jar file will run the program if Java is installed. Please note that this resource requires at least version 1.5 of Java (JRE).

Aguirregabiria, Juan

2011-09-09

179

Qualitative Assessment of Flow and Transport Mechanisms in Bioremediation Processes  

Science.gov (United States)

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

180

Similarity between the spiral arms of Galaxy M51 image and the interface curve of Yin-Yang balance in the Ancient Tai-Chi diagram  

Science.gov (United States)

The particle paths of the Lagrangian flow field between two cylinders simulate well the spiral arms of Galaxy M51 image [1] and the interface curve of the Yin-Yang balance in the ancient Tai-Chi diagram [2]. The particle paths of the Lagrangian flow field involve four parameters. The normalization of the system of equations significantly simplifies the formulation of the flow process and reduces the original four parameters to only one parameter. Furthermore it provides the similarity between the formulation of the spiral arms of Galaxy M51 and that of the interface curve of the Yin-Yang balance in the ancient Tai-Chi diagram.

Lin, Sui

2009-03-01

 
 
 
 
181

Eigenanalysis of a neural network for optic flow processing  

Energy Technology Data Exchange (ETDEWEB)

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.

Weber, F; Eichner, H; Borst, A [Department of Systems and Computational Neuroscience, Max-Planck-Institute of Neurobiology, Martinsried (Germany); Cuntz, H [Wolfson Institute for Biomedical Research, Department of Physiology, University College London (United Kingdom)], E-mail: weberf@neuro.mpg.de

2008-01-15

182

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

183

Probing the QCD phase diagram with measurements of phi-meson production and elliptic flow in heavy-ion collisions at STAR  

Science.gov (United States)

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 = 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

184

Impulse-Momentum Diagrams  

Science.gov (United States)

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

185

Investigation of Multiscale and Multiphase Flow, Transport and Reaction in Heavy Oil Recovery Processes  

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

186

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

187

A semantic model of data flow networks based on process algebras  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Data flow networks are a paradigm for concurrent computations in which a collection of parallel processes communicate asynchronously. For data flow many compositional semantics models have been defined, however, it is extremely complex to reason about their semantic behaviour. To perform the semantic analysis of data flow networks, we define a transformation from data flow to specifications in the process algebras formalism which preserves the traces of the networks. The main contribution of ...

Bernardeschi, Cinzia; Bondavalli, Andrea; Simoncini, Luca

1993-01-01

188

OP-0001-P1 GTEx Specimen Collection Supplies and Shipping Kit Process Flow  

Science.gov (United States)

Kit Receipt Supply Shipping Procedure Process Flow Biospecimen Source Site Processing Centers Kit Supplies to the BSSs Shipping Processing Collection Event & Packing Work Instruction for Packing & Shipping Green Kit (OP-0001-W2) [Alert Courier & Obtain

189

Transport phenomena of reactive fluid flow in heterogeneous combustion processes.  

Science.gov (United States)

A previously developed computer program was used to model two transient hybrid combustion processes involving tubes of solid Plexiglas. In the first study, representing combustion of a hybrid rocket, the oxidizing gas was oxygen, and calculations were continued sufficiently long to obtain steady-state values. Systematic variations were made in reaction rate constant, mass flow rate, and pressure, alternatively using constant and temperature dependent regression rate models for the fuel surface. Consistent results were obtained, as is evidenced by the values for the mass function of the reaction product and the flame temperature, for which plots are supplied. In the second study, fire initiation in a duct was studied, with an air mixture as the oxidizing gas. It was demonstrated that a satisfactory flame spread mechanism could be reproduced on the computer. In both of the above applications, the general, transient, two-dimensional conservation equations were represented, together with chemical reactions, solid-fuel interface conditions, and heat conduction in the solid fuel.

Hung, W. S. Y.; Chen, C. S.; Haviland, J. K.

1972-01-01

190

An Introduction to Tree Diagrams  

Science.gov (United States)

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

191

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

Science.gov (United States)

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 ...

192

Damping of unsteady flows in the physical vapor transport process  

Science.gov (United States)

The dynamics of the flow field during physical vapor transport of mercurous chloride is analyzed computationally for practical crystal growth conditions to distinguish between unsteady flow and thermal stress as the cause of crystal inhomogeneity. We analyze the flow field over the parametric range of 1.56 multiplied by 102 less than or equal to Ra less than or equal to 2.08 multiplied by 105, .011 less than or equal to Ar less than or equal to .112, and show that the effect of thermal stress as the cause of crystal inhomogeneity can be investigated by performing experiments with low aspect ratio enclosures for Ar less than .028 and Ra less than 2.4 multiplied by 103 for which the flow becomes diffusive-advective. Dynamical characteristics of the flow field indicate a transition from chaotic flow Ra equals 2.08 multiplied by 105 to steady flow Ra less than 1.4 multiplied by 104 occurs through period doubling. A microgravity environment can be used effectively to grow high quality crystals, if thermal stresses are not the cause of crystal inhomogeneity, since unsteady flows are damped regardless of the aspect ratio of the enclosure.

Duval, Walter M. B.; Singh, N. B.; Glicksman, M. E.

1997-07-01

193

Composite Hubble diagram  

International Nuclear Information System (INIS)

The composite Hubble diagram for 663 normal galaxies, 235 radio galaxies, and 265 quasi-stellar objects is given. The least squares solution to the Hubble diagram slope for each of the three classes of objects is compatible, within the errors, with that expected for a homogeneous, isotropic, expanding universe. If the Hubble constant H0=50 km s-1 Mpc-1, then =-21.150, =1043.96 ergs s-1, and sigma/subM/=0.887 for normal galaxies; =-23.061, =1044.72 ergs s-1, and sigma/subM/=0.684 for radio galaxies; and =-25.784, =1045.81 ergs s-1 and sigma/subM/=1.451 for the quasi-stellar objects. Here denotes the mean absolute visual magnitude, denotes the mean absolute optical luminosity, and sigma/subM/ denotes the dispersion in magnitude. It is shown that the uncertainty in the slope of the Hubble diagram for QSOs is comparable to that obtained for normal galaxies over a similar range in magnitude. This means that the scatter in the QSO Hubble diagram should not be used in arguments which question their cosmological nature. It is shown that the absolute optical luminosity of extragalactic objects increases with increasing redshift, and that any given object class occurs infrequently in the magnitude and redshift range of the others. These facts suggest an evolutionary sequence in which bright young QSutionary sequence in which bright young QSOs evolve into older, less luminous radio galaxies, which in turn evolve into the weaker, still older normal galaxies

194

Homotopy Diagrams of Algebras  

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

195

Features, Events, and Processes in UZ Flow and Transport  

International Nuclear Information System (INIS)

luded 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

196

The Massive Thermal Basketball Diagram  

CERN Document Server

The "basketball diagram" is a three-loop vacuum diagram for a scalar fieldtheory that cannot be expressed in terms of one-loop diagrams. We calculatethis diagram for a massive scalar field at nonzero temperature, reducing it toexpressions involving three-dimensional integrals that can be easily evaluatednumerically. We use this result to calculate the free energy for a massivescalar field with a phi^4 interaction to three-loop order.

Andersen, J O; Strickland, Michael T; Andersen, Jens O.; Braaten, Eric; Strickland, Michael

2000-01-01

197

VennDiagram: a package for the generation of highly-customizable Venn and Euler diagrams in R  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Visualization of orthogonal (disjoint or overlapping datasets is a common task in bioinformatics. Few tools exist to automate the generation of extensively-customizable, high-resolution Venn and Euler diagrams in the R statistical environment. To fill this gap we introduce VennDiagram, an R package that enables the automated generation of highly-customizable, high-resolution Venn diagrams with up to four sets and Euler diagrams with up to three sets. Results The VennDiagram package offers the user the ability to customize essentially all aspects of the generated diagrams, including font sizes, label styles and locations, and the overall rotation of the diagram. We have implemented scaled Venn and Euler diagrams, which increase graphical accuracy and visual appeal. Diagrams are generated as high-definition TIFF files, simplifying the process of creating publication-quality figures and easing integration with established analysis pipelines. Conclusions The VennDiagram package allows the creation of high quality Venn and Euler diagrams in the R statistical environment.

Boutros Paul C

2011-01-01

198

Large eddy simulations of turbulent flows on graphics processing units: Application to film-cooling flows  

Science.gov (United States)

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.

199

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

200

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

 
 
 
 
201

Modeling Yin-Yang balance in tai-chi diagram with a melting-freezing rotating device part 3 — The contemporary tai-chi diagram, the yuan-chi diagram and the Fu Xi's eight trigrams  

Science.gov (United States)

The physical model describing the Yin-Yang balance in the tai-chi diagram via the melting and freezing processes in a rotating device presented in parts 1 and 2 is further developed for the contemporary tai-chi diagram and in the yuan-chi diagram. The contemporary tai-chi diagram shown in Fig.1 is a simplification form of the ancient tai-chi diagram presented in Reference [2]. There are two semi-circles forming the interface curve between the yin and yang in the contemporary tai-chi diagram. By knowing the location of the interface between the yin and yang in the contemporary tai-chi diagram, the requirement for the simulation model is to find the condition to match the interface location. The simplification changes not only the structure but also the physical insight of the ancient tai-chi diagram, which will be described in the present study. The yuan-chi diagram shown in Fig.2 is the combination of the Master Chen’s tai-chi diagram presented in References [1,2] and the contemporary tai-chi diagram. The formulation of the yuan-chi diagram is similar to that of contemporary tai-chi diagram. The Fu Xi’s eight trigrams present three levels of yin-yang relation that are a natural result from the contemporary tai-chi diagram, which will be described in the last part of this study.

Lin, Sui; Chen, Tzu-Fang

2002-11-01

202

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

... The batch polymerizations were carried out in a series of different glass vessels, using either magnetic or overhead stirring, and different modes of heating: Microwave irradiation or conductive heating in an oil bath. The continuous process was conducted in a prototype tubular flow reactor, consisting of 6 mm ID stainless steel tubing, fitted with static mixers. Both reactor types were tested for polymerizations of the ... Levitation positions of single bubbles were optically characterized. A correlation was developed for the drag force coefficient, CD, including wall effects based on the force equilibrium. A linear decrease of bubble diameters was identified with and without chemical reaction, which is referred to as a rigid bubble surface area. Measured Sherwood numbers agree well with the literature values for the investigated Reynolds number range. ...

203

Design of image processing embedded systems using multidimensional data flow  

CERN Document Server

This book presents a new set of embedded system design techniques called multidimensional data flow, which combine the various benefits offered by existing methodologies such as block-based system design, high-level simulation, system analysis and polyhedral optimization. It describes a novel architecture for efficient and flexible high-speed communication in hardware that can be used both in manual and automatic system design and that offers various design alternatives, balancing achievable throughput with required hardware size. This book demonstrates multidimensional data flow by showing it

Keinert, Joachim

2010-01-01

204

Parallel Computation of Feynman diagrams with DIANA  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Co-operation of the Feynman DIagram ANAlyzer (DIANA) with the underlying operational system (UNIX) is presented. We discuss operators to run external commands and a recent development of parallel processing facilities and an extension in the spirit of a component model.

Tentyukov, M.; Fleischer, J.

2003-01-01

205

Warped penguin diagrams  

International Nuclear Information System (INIS)

We present an analysis of the loop-induced magnetic dipole operator in the Randall-Sundrum model of a warped extra dimension with anarchic bulk fermions and an IR brane-localized Higgs. These operators are finite at one-loop order and we explicitly calculate the branching ratio for ??e? using the mixed position/momentum space formalism. The particular bound on the anarchic Yukawa and Kaluza-Klein (KK) scales can depend on the flavor structure of the anarchic matrices. It is possible for a generic model to either be ruled out or unaffected by these bounds without any fine-tuning. We quantify how these models realize this surprising behavior. We also review tree-level lepton flavor bounds in these models and show that these are on the verge of tension with the ??e? bounds from typical models with a 3 TeV Kaluza-Klein scale. Further, we illuminate the nature of the one-loop finiteness of these diagrams and show how to accurately determine the degree of divergence of a five-dimensional loop diagram using both the five-dimensional and KK formalism. This power counting can be obfuscated in the four-dimensional Kaluza-Klein formalism and we explicitly point out subtleties that ensure that the two formalisms agree. Finally, we remark on the existence of a perturbative regime in which these one-loop results give the dominant contribution.

206

Impact decision support diagrams  

Science.gov (United States)

One way to frame the job of planetary defense is to “find the optimal approach for finding the optimal approach” to NEO mitigation. This requires a framework for defining in advance what should be done under various circumstances. The two-dimensional action matrix from the recent NRC report “Defending Planet Earth” can be generalized to a notional “Impact Decision Support Diagram” by extending it into a third dimension. The NRC action matrix incorporated two important axes: size and time-to-impact, but probability of impact is also critical (it is part of the definitions of both the Torino and Palermo scales). Uncertainty has been neglected, but is also crucial. It can be incorporated by subsuming it into the NEO size axis by redefining size to be three standard deviations greater than the best estimate, thereby providing a built-in conservative margin. The independent variable is time-to-impact, which is known with high precision. The other two axes are both quantitative assessments of uncertainty and are both time dependent. Thus, the diagram is entirely an expression of uncertainty. The true impact probability is either one or zero, and the true size does not change. The domain contains information about the current uncertainty, which changes with time (as opposed to reality, which does not change).

Boslough, Mark

2014-10-01

207

Transformation of Debris Flows Into Turbidity Currents: a key Process for Hazard Prediction  

Science.gov (United States)

Although landslides start as a dense mass of sediment, flow transformation into more dilute flows can alter flow properties and thus associated hazards. A good understanding of the transformation process is therefore critical for accurately predicting hazard potential. To improve understanding of flow transformations in gravity currents, three series of lock exchange laboratory experiments were undertaken, for cohesive flows, non-cohesive flows and mixed flows containing both cohesive and non-cohesive material. These experiments had a flow volume of 120 litres and initial volumetric concentrations ranging from 4 % to 40 %. Flows travelled along a 5.5 m long, 0.2 m wide channel, within a larger (6 m by 0.5 m by 1.5 m) glass-walled flume. Velocity was measured using a vertical array of ten 2 MHz Ultrasonic Velocity Probes and concentration was measured using an Ultrasonic High Concentration Meter in conjunction with siphon sampling. Video cameras were used at several positions along the flume to track flow behaviour. A full suite of flows was observed, from flows that underwent rapid transformation to flows that underwent almost no dilution and transformation. These experiments enable the effects of sediment type (e.g., cohesive, non-cohesive), velocity and concentration on flow transformation to be quantified for the first time.

Felix, M.; Peakall, J.

2002-12-01

208

Influence of surface processes on gas flow in nanoscale capillaries  

International Nuclear Information System (INIS)

Theoretical study of free molecular gas flow in nanoscale capillary taking into account joint effect of different schemes of molecule scattering by the capillary wall and surface diffusion of adsorbed molecules is conducted. The problem of radiation-induced drift of molecules in capillaries is discussed. Influence of adsorbable foreign gases on phase transitions in nanoscale capillaries is considered. (authors)

209

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

210

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

211

Using Eye Tracking to Investigate Semantic and Spatial Representations of Scientific Diagrams During Text-Diagram Integration  

Science.gov (United States)

We investigated strategies used by readers when reading a science article with a diagram and assessed whether semantic and spatial representations were constructed while reading the diagram. Seventy-one undergraduate participants read a scientific article while tracking their eye movements and then completed a reading comprehension test. Our results showed that the text-diagram referencing strategy was commonly used. However, some readers adopted other reading strategies, such as reading the diagram or text first. We found all readers who had referred to the diagram spent roughly the same amount of time reading and performed equally well. However, some participants who ignored the diagram performed more poorly on questions that tested understanding of basic facts. This result indicates that dual coding theory may be a possible theory to explain the phenomenon. Eye movement patterns indicated that at least some readers had extracted semantic information of the scientific terms when first looking at the diagram. Readers who read the scientific terms on the diagram first tended to spend less time looking at the same terms in the text, which they read after. Besides, presented clear diagrams can help readers process both semantic and spatial information, thereby facilitating an overall understanding of the article. In addition, although text-first and diagram-first readers spent similar total reading time on the text and diagram parts of the article, respectively, text-first readers had significantly less number of saccades of text and diagram than diagram-first readers. This result might be explained as text-directed reading.

Jian, Yu-Cin; Wu, Chao-Jung

2014-10-01

212

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

213

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

214

A Regime Diagram for Subduction  

Science.gov (United States)

Regime diagrams and associated scaling relations have profoundly influenced our understanding of planetary dynamics. Previous regime diagrams characterized the regimes of stagnant-lid, small viscosity contrast, transitional, and no-convection for temperature-dependent (Moresi and Solomatov, 1995), and non-linear power law rheologies (Solomatov and Moresi, 1997) as well as stagnant-lid, sluggish-lid, and mobile-lid regimes once the finite strength of rock was considered (Moresi and Solomatov, 1998). Scalings derived from such models have been the cornerstone for parameterized models of thermal evolution of rocky planets and icy moons for the past decade. While such a theory can predict the tectonic state of a planetary body, it is still rather incomplete in regards to predicting tectonics. For example, the mobile-lid regime is unspecific as to how continuous lithospheric recycling should occur on a terrestrial planet. Towards this goal, Gerya et al., (2008) advanced a new regime diagram aiming to characterize when subduction would manifest itself as a one-sided or two-sided downwelling and either symmetric or asymmetric. Here, we present a regime diagram for the case of a single-sided, asymmetric type of subduction (most Earth-like type). Using a 3-D numerical model of a free subduction, we describe a total of 5 different styles of subduction that can possibly occur. Each style is distinguished by its upper mantle slab morphology resulting from the sinking kinematics. We provide movies to illustrate the different styles and their progressive time-evolution. In each regime, subduction is accommodated by a combination of plate advance and slab rollback, with associated motions of forward plate velocity and trench retreat, respectively. We demonstrate that the preferred subduction mode depends upon two essential controlling factors: 1) buoyancy of the downgoing plate and 2) strength of plate in resisting bending at the hinge. We propose that a variety of subduction regimes are generated primarily as a product of two mechanisms. The first mechanism is that of the competition between the weight of the slab and the strength of the plate, which can be understood in terms of the applied bending moment, and this competition results in a particular radius of curvature (for which we provide a simple scaling theory). The second mechanism is the interaction between the slab and the more viscous lower mantle, which produces each regime's distinct slab morphology. Thus, the emergence of five distinct styles of subduction is a direct consequence of the presence of the modest barrier to flow into the lower mantle. Although only 2 of these styles presently operate on Earth, the possibility exists that other modes may have been the predominant mode in the past. Based on these models, we propose that the lithosphere is the primary factor in describing key elements of the plate tectonics system over time, rather than the convecting mantle. We discuss the various factors that may have influenced secular changes in Earth's tectonic behavior, some of which may have interesting consequences for the geochemical evolution of the Earth.

Stegman, D. R.; Farrington, R.; Capitanio, F. A.; Schellart, W. P.

2009-12-01

215

Aerodynamic Structures and Processes in Rotationally Augmented Flow Fields  

DEFF Research Database (Denmark)

Rotational augmentation of horizontal axis wind turbine blade aerodynamics currently remains incompletely characterized and understood.To address this, the present study concurrently analysed experimental measurements and computational predictions, both of which were unique and of high quality. Experimental measurements consisted of surface pressure data statistics used to infer sectional boundary layer state and to quantify normal force levels.Computed predictions included high-resolution boundary layer topologies and detailed above-surface flow field structures. This synergy was exploited to reliably identify and track pertinent features in the rotating blade boundary layer topology as they evolved in response to varying wind speed.Subsequently,boundary layer state was linked to abovesurface flow field structure and used to deduce mechanisms underlying augmented aerodynamic force production during rotating conditions.

Schreck, Scott J.; SØrensen, Niels

2007-01-01

216

Aerodynamic structures and processes in rotationally augmented flow fields  

DEFF Research Database (Denmark)

Rotational augmentation of horizontal axis wind turbine blade aerodynamics currently remains incompletely characterized and understood. To address this, the present study concurrently analysed experimental measurements and computational predictions, both of which were unique and of high quality. Experimental measurements consisted of surface pressure data statistics used to infer sectional boundary layer state and to quantify normal force levels. Computed predictions included high-resolution boundary layer topologies and detailed above-surface flow field structures. This synergy was exploited to reliably identify and track pertinent features in the rotating blade boundary layer topology as they evolved in response to varying wind speed. Subsequently, boundary layer state was linked to above-surface flow field structure and used to deduce mechanisms; underlying augmented aerodynamic force production during rotating conditions. Copyright (C) 2007 John Wiley & Sons, Ltd.

SØrensen, Niels N.

2007-01-01

217

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

218

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 UO2(NO3)2 - Pu(NO3)4 - HNO3/30% 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)

219

Digital video image processing applications to two phase flow measurements  

International Nuclear Information System (INIS)

Liquid spraying is common in various fields (combustion, cooling of hot surfaces, spray drying,...). For two phase flows modeling, it is necessary to test elementary laws (vaporizing drops, equation of motion of drops or bubbles, heat transfer..). For example, the knowledge of the laws related to the behavior of vaporizing liquid drop in a hot airstream and impinging drops on a hot surface is important for two phase flow modeling. In order to test these different laws in elementary cases, the authors developed different measurement techniques, associating video and microcomputers. The test section (built in perpex or glass) is illuminated with a thin sheet of light generated by a 15mW He-Ne laser and appropriate optical arrangement. Drops, bubbles or liquid film are observed at right angle by a video camera synchronised with a microcomputer either directly or with an optical device (lens, telescope, microscope) providing sufficient magnification. Digitizing the video picture in real time associated with an appropriate numerical treatment allows to obtain, in a non interfering way, a lot of informations relative to the pulverisation and the vaporization as function of space and time (drop size distribution; Sauter mean diameter as function of main flow parameters: air velocity, surface tension, temperature; isoconcentration curves, size evolution relative to vaporizing drops, film thickness evolution spreading on a hot surface...)..)

220

Generating function for web diagrams  

Science.gov (United States)

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 an 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.

2014-09-01

 
 
 
 
221

Box diagram in Yukawa theory  

International Nuclear Information System (INIS)

We present a light-front calculation of the box diagram in Yukawa theory. The covariant box diagram is finite for the case of spin-1/2 constituents exchanging spin-0 particles. In light-front dynamics, however, individual time-ordered diagrams are divergent. We analyze the corresponding light-front singularities and show the equivalence between the light-front and covariant results by taming the singularities

222

Hopf diagrams and quantum invariants  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The Reshetikhin-Turaev invariant, Turaev's TQFT, and many related constructions rely on the encoding of certain tangles (n-string links, or ribbon n-handles) as n-forms on the coend of a ribbon category. We introduce the monoidal category of Hopf diagrams, and describe a universal encoding of ribbon string links as Hopf diagrams. This universal encoding is an injective monoidal functor and admits a straightforward monoidal retraction. Any Hopf diagram with n legs yields a n-...

Bruguieres, Alain; Virelizier, Alexis

2005-01-01

223

(?, ?) uniform-scale chromaticity diagram  

Science.gov (United States)

The non-uniformity of scale in the usual chromaticity diagrams is a very old problem in colour measurements. This program computes the transformation from the CIE 1931 ( x, y) chromaticity diagram to the recent uniform scale (?, ?) diagram and vice-versa. Moreover the program evaluates the most important colorimetric quantities for a comparison with the experimental data. Finally the chromatic gamut needed for TV applications is shown.

Oleari, Claudio; Formaleoni, Guido

1992-02-01

224

Petrologic hypothesis testing with Pearce element ratio diagrams: derivation of diagram axes  

Science.gov (United States)

In petrology, Pearce element ratio (PER) diagrams have been used: i) to determine whether members of a rock suite are co-genetic, ii) to identify the minerals involved in differentiation processes, and iii) to evaluate the extent to which those mineral are involved. The axis coefficients of each diagram are chosen such that sorting of minerals or combinations of minerals will generate unique and predictable trends. Unfortunately, selection of the optimal combination of axis coefficients is a difficult task, especially if the system being investigated has a large number of phases or complicated solid solution minerals. Our work has established a formal set of rules and matrix operations which facilitate the determination of PER diagram axes coefficients. This methodology can be used to determine the unit molar vector displacement caused by the addition or subtraction of a specific mineral, given a set of axis coefficients. It can also be used to create PER diagrams on which minerals have predetermined vector displacements. By designating all vector displacements to be parallel, axis coefficients for assemblage test diagrams can be determined to test the following hypothesis: the observed chemical variation is due to the addition ( or removal) of a specific set of minerals. Alternatively, by designating all vector displacements to be mutually perpendicular, phase discrimination diagrams can be created which test whether the observed chemical variations require a specific phase to be involved in differentiation. Phase discrimination diagrams also provide a means to estimate the extent of that involvement. This methodology facilitates construction of powerful yet simple PER diagrams which provide an effective means of testing alternative differentiation hypotheses.

Stanley, C. R.; Russell, J. K.

1989-09-01

225

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

226

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

227

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

228

PRACTICAL ASPECTS OF QUALITY ASSURANCE AND IMPROVEMENT IN TROUSERS MANUFACTURING PROCESS  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The paper presents a case-study for trousers manufacturing and more specific, an analysis of quality control system and action plan for improving the quality level. Using data collected in specific check points, the statistical tools as control chart, Pareto diagram, flow chart, histograms, and Fishbone diagram are applied in order to adjust the manufacturing process and improve the quality.

Raluca Brad; Remus Brad

2012-01-01

229

Gas/slurry flow in coal-liquefaction processes (fluid dynamics in 3 phase flow columns)  

Science.gov (United States)

The 6000 T/D SRC-I demonstration plant will employ vertical tublar reactors feeding slurry and gas concurrently upward. This reactor is essentially an empty vessel with only a distributor plate located near the inlet. Because the commercial plant represents a considerable scale-up over either Wilsonville or Ft. Lewis, this program is addressing the need for additional data on the behavior of three phase systems in large vessels. Parameters are being studied at conditions that relate directly to the projected demonstration plant operating conditions. Air/water/sand three phase flow system in both a 5-inch diameter and a 12-inch diameter column is used in this cold-flow simulation study program.

Ying, D. H. S.; Sivasubramanian, R.; Givens, E. N.

1980-12-01

230

Electrical Processes in a Flowing Plasma with Cold Electrodes  

International Nuclear Information System (INIS)

The voltage-current characteristics of a flowing plasma between two electrodes is of interest for MHD power generation because of the high voltage drop necessary to make a current flow through the cool boundary layer of the plasma, lowering the efficiency of the MHD generator when the duct walls are cooled. The V-I characteristics are obtained for a combustion driven shock-tube generated plasma, and the voltage distribution is measured by probes inserted across the plasma. The gas used is argon and the plasma parameters are: T = 9000°K, p = 130 mmHg, u = 2500 m/sec, ne = 1.60 x 1015 cm-3. The probe technique has allowed experimental confirmation of the high voltage drop obtained in the vicinity of the cathode. A theoretical model has been set up in order to explain the main features of this phenomenon. The model considers the voltage drop along the following regions: the turbulent boundary layer and the viscous sublayer. The structure of the first two regions are taken into account according to the Coles transformation theory. The model considers three fluids, ions, electrons and neutrals: the mass and momentum particle conservation together with the Poisson equation and continuity of electric current allows us to set up a system of four differential equations with four unknowns. Pair production is taken into account in order to explain the necessary change over from electron current in the main body of the plasma to the predominantly ionic current in the neighbourhood of the cathode wall. Numerical computation of the system of equations has been done and the main features of the experimental results are explained. (author)

231

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

Science.gov (United States)

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

232

PRODUCTIVITY IMPROVEMENT IN MOULDING BY CHANGES IN WORK PROCESS FLOW  

Directory of Open Access Journals (Sweden)

Full Text Available Foundry industry suffers from poor quality and productivity due to the large number of process parameters, combined with lower penetration of manufacturing automation and shortage of skilled workers compared to other industries. Productivity is development of an attitude of mind and constant urge to find better, cheaper, easier, quicker and safer means of doing a job, manufacturing a product and providing service. It is the certainty of being able to do better today than yesterday, and continuously. Productivity is purely a concept of real process. It is defined as the relation ship of output to associated inputs. Real process that combines the inputs in order to make output includes practically all the activities of a company. Improving productivity it will help the management to analyze on continuing basis. Improving productivity is nothing but the reduction in wastage of resources like men, machines, material, power, space, time etc. Productivity improvement by means of The Improve existing methods of plant operation, Improve the planning of work and the use of manpower, Increase the effectiveness of all employees. This helps correct identification of the unwanted process. Based on this results and their interpretation the optimal values of the parameters are determined to eliminate the unwanted process. The proposed approach overcomes the problems, causes of Low productivity and it improved the productivity

K. Subrahmanyam

2014-04-01

233

Views on the calculation of flow and dispersion processes in fractured rock  

International Nuclear Information System (INIS)

In the report some basic aspects on model types, physical processes, determination of parameters are discussed in relation to a description of flow and dispersion processes in fractured rocks. As far as model types concern it is shown that Darcy's law and the dispersion equation are not especially applicable. These equations can only describe an average situation of flow and spreading while in reality very large deviations could exist between an average situation and the flow and concentration distribution for a certain fracture geometry. The reason for this is primarily the relation between the length scales for the repository and the near field and the fracture system respectively and the poor connectivity between fractures or expressed in another way - the geosphere can not be treated as a continuous medium. The statistical properties of the fractures and the fracture geometry cause large uncertainties in at least two respects: * boundary conditions as to groundwater flow at the repository and thus the mass flow of radioactive material * distribution of flows and concentrations in planes in the geosphere on different distances from the repository. A realistic evaluation of transport and spreading of radioactive material by the groundwater in the geosphere thus requires that the possible variation or uncertainty of the water conducting characteristics of the fracture system is considered. A possible approach is then to describe flow in the geosphere on the basic of the flow in single fractures which are hydraulically connected to each other so that a flow in a fracture system is obtained. The discussion on physical processes which might influence the flow description in single fractures is concentrated to three aspects - factors driving the flow besides the ordinary hydraulic gradient, the viscous properties of water in a very small space (such as a fracture), the influence on the flow of heat release from the repository. (42 figs., 28 refs.)

234

Sensitivity analysis of reacting two-phase flow in nuclear heat-based gasification process  

Directory of Open Access Journals (Sweden)

Full Text Available Current work investigates influence of operating parameters on chemical reactions occuring within two-phase reacting flow. This particular flow analysed, corresponds to processes in coal gasifier unit supplied in heat by a high temperature gas cooled nuclear reactor (HTGR.Due to the fact that gasification is a complex process, in which multiphase mixture undergoes chemical reactions, it crucial to answer questions about sensitivity to parameters changes. Performed analysis was dedicated to answer question about the optimal flow parameters. Controll of flow patern, namely the swirl of coal-oxygen mixture traversing the gasifier domain, allowed creating efficiency curve, relating gas composition with non-axial component of the velocity vector.Using numerical model of the process, numbers of simulations were run in order to determine operation point yielding the highest efficiency, defined as a ratio of lower heating values of a syngas product of gasification process and coal feed into the unit.

Jakub Marcin Kupecki

2011-01-01

235

Heat transfer processes in the upper crust : influence of structure, fluid flow, and palaeoclimate  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Numerical models constrained by geological and geophysical data form the basis of understanding the thermal regime of the Earth's crust. This dissertation focuses on modelling heat transport in the upper crust, studying the relative contributions of different processes to the specific heat flow distribution. Its vertical variation is a well known fact, caused by different processes such as changes in surface temperature, fluid flow, and heterogeneity. In particular, the first one can provide ...

Mottaghy, Darius Christopher

2007-01-01

236

Stochastic flows, reaction-diffusion processes, and morphogenesis  

International Nuclear Information System (INIS)

Recently, an exact procedure has been introduced [C. A. Walsh and J. J. Kozak, Phys. Rev. Lett.. 47: 1500 (1981)] for calculating the expected walk length for a walker undergoing random displacements on a finite or infinite (periodic) d-dimensional lattice with traps (reactive sites). The method (which is based on a classification of the symmetry of the sites surrounding the central deep trap and a coding of the fate of the random walker as it encounters a site of given symmetry) is applied here to several problems in lattice statistics for each of which exact results are presented. First, we assess the importance of lattice geometry in influencing the efficiency of reaction-diffusion processs in simple and multiple trap systems by reporting values of for square (cubic) versus hexagonal lattices in d = 2,3. We then show how the method may be applied to variable-step (distance-dependent) walks for a single walker on a given lattice and also demonstrate the calculation of the expected walk length for the case of multiple walkers. Finally, we make contact with recent discussions of ''mixing'' by showing that the degree of chaos associated with flows in certain lattice-systems can be calibrated by monitoring the lattice walks induced by the Poincare map of a certain parabolic function

237

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

Science.gov (United States)

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 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

238

Experimental study of air flow rate effects on humidification parameters with preheating and dehumidification process changing  

Directory of Open Access Journals (Sweden)

Full Text Available The objective of this research is to study experimentally the effect of air flow rate on humidification process parameters. Experimental data are obtained from air conditioning study unit T110D. Results obtained from experimental test, calculations and psychometrics software are discussed. The effect of air flow rate on steam humidification process parameters as a part of air-conditioning processes can be explain in results obtained. Results of the steam humidification process with and without preheating with 5A and 7.5A shows decreasing in dry bulb temperature, humidity ratio, and heat add to moist air with increasing air flow rate, but humidification load, and total energy of moist air increase with increasing air flow rate in the testing tunnel. The steam humidification process with dehumidifying coil shows increase in dry bulb temperature, humidity ratio, humidification load, and heat add to moist air with increasing air flow rate in the testing tunnel, but the total energy decrease as air flow rate increase. These results obtained can be beneficial for controlling comfort air-conditioning processes in buildings.

Ayad T. Mustafa

2011-09-01

239

Medição do inventário em processo e tempo de atravessamento em manufatura por modelagem em redes de Petri e diagrama de resultados Measurement of work-in-process and manufacturing leadtime by Petri nets modeling and throughput diagram  

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

240

Quantum Fisher information flow and non-Markovian processes of open systems  

International Nuclear Information System (INIS)

We establish an information-theoretic approach for quantitatively characterizing the non-Markovianity of open quantum processes. Here, the quantum Fisher information (QFI) flow provides a measure to statistically distinguish Markovian and non-Markovian processes. A basic relation between the QFI flow and non-Markovianity is unveiled for quantum dynamics of open systems. For a class of time-local master equations, the exactly analytic solution shows that for each fixed time the QFI flow is decomposed into additive subflows according to different dissipative channels.

 
 
 
 
241

Recent results in Ring Diagram analysis  

CERN Document Server

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

242

Laser Doppler blood flow complementary metal oxide semiconductor imaging sensor with analog on-chip processing  

International Nuclear Information System (INIS)

A 4x4 pixel array with analog on-chip processing has been fabricated within a 0.35 ?m complementary metal oxide semiconductor process as a prototype sensor for laser Doppler blood flow imaging. At each pixel the bandpass and frequency weighted filters necessary for processing laser Doppler blood flow signals have been designed and fabricated. Because of the space constraints of implementing an accurate ?0.5 filter at the pixel level, this has been approximated using the ''roll off'' of a high-pass filter with a cutoff frequency set at 10 kHz. The sensor has been characterized using a modulated laser source. Fixed pattern noise is present that is demonstrated to be repeatable across the array and can be calibrated. Preliminary blood flow results on a finger before and after occlusion demonstrate that the sensor array provides the potential for a system that can be scaled to a larger number of pixels for blood flow imaging

243

Process Flow Sheet Generation & Design through a Group Contribution Approach  

DEFF Research Database (Denmark)

Denne afhandling beskriver udviklingen af et framework til opstilling og design af proces flowsheet ved hjælp af en systematisk strategi for Computer Aided Flowsheet Design (CAFD). Det udviklede framework omfatter formulering, løsning og analyse af CAFD problemer baseret på et koncept med procesgrupper som kan repræsentere en enkelt enhedsoperation eller en række enhedsoperationer på samme måde som en molekylgruppe kan repræsentere et atom eller en gruppe af atomer. Flowsheet for kemiske processer opstilles, modelleres og analyseres ved definitionen af disse procesgrupper, deres forbindelsesregler samt deres bidrag til specifikke flowsheet egenskaber på samme måde som kemiske molekyler bliver syntetiseret og testet for deres egenskaber. Hertil er simple og effektive metoder til processyntese og design blevet udviklet. Alternative flowsheet for kemiske processer opstilles baglæns ved at kombinere procesgrupper således at der dannes flowsheet strukturer som har de ønskede egenskaber. Derefter udvælges de mest lovende flowsheetalternativer til design hvorved de enkelte enhedsoperationer beregnes baglæns udfra specifikationerne for deres ind- og udgangsstrømme svarende til procesgruppernes ind- og udgangsstrømme. Det udviklede framework med tilknyttede computerbaserede metoder og værktøjer er blevet testet på en serie case studier og anvendelseseksempler.

d'Anterroches, Loïc

2006-01-01

244

Phase diagram of polypeptide chains  

Science.gov (United States)

We use a coarse grained protein model that enables us to determine the equilibrium phase diagram of natively folded ?-helical and unfolded ?-sheet forming peptides. The phase diagram shows that there are only two thermodynamically stable peptide phases, the peptide solution and the bulk fibrillar phase. In addition, it reveals the existence of various metastable peptide phases. The liquidlike oligomeric phases are metastable with respect to the fibrillar phases, and there is a hierarchy of metastability. The presented phase diagram provides a solid basis for understanding the assembly of polypeptide chains into the phases formed in their natively folded and unfolded conformations.

Auer, Stefan

2011-11-01

245

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

246

Numerical determination of the forming limit diagrams  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Purpose: At present the industrial practice demands a reliable determination of forming limits which assuresthe prediction of properly selecting the forming process in a digital environment. Therefore, technological limitsdefined with the forming limit diagrams (FLDs) have to be known. The experimental evaluation of FLDs forsheet metal is time consuming and demands expensive equipment. The experimental work could be omitted bypredicting the FLD with numerical simulations.Design/methodology/ap...

Pepelnjak, T.; Kuzman, K.

2007-01-01

247

Feynman diagram approach to atomic collisions  

International Nuclear Information System (INIS)

A quantum field theoretic formulation of atomic collision phenomena involving non-relativistic free and bound systems is developed and a calculational procedure in terms of Feynman diagrams is prescribed. Matrix elements of several atomic collision processes have been calculated. In most cases standard quantum mechanical results are reproduced. But in some cases new terms appear in the scattering matrix whose contribution though negligibly small in the low energy region, become important at higher energies. (auth.)

248

Improving Web Database Access Using Decision Diagrams  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In some areas of management and commerce, especially in Electronic commerce (E-commerce), that are accelerated by advances in Web technologies, it is essential to support the decision making process using formal methods. Among the problems of E-commerce applications: reducing the time of data access so that huge databases can be searched quickly; decreasing the cost of database design ... etc. We present the application of Decision Diagrams design using Information Theory ap...

Popel, Denis V.; Al-hakeem, Nawar

2002-01-01

249

Particles, Feynman Diagrams and All That  

Science.gov (United States)

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

250

Online traffic flow model applying dynamic flow-density relation  

International Nuclear Information System (INIS)

This dissertation describes a new approach of the online traffic flow modelling based on the hydrodynamic traffic flow model and an online process to adapt the flow-density relation dynamically. The new modelling approach was tested based on the real traffic situations in various homogeneous motorway sections and a motorway section with ramps and gave encouraging simulation results. This work is composed of two parts: first the analysis of traffic flow characteristics and second the development of a new online traffic flow model applying these characteristics. For homogeneous motorway sections traffic flow is classified into six different traffic states with different characteristics. Delimitation criteria were developed to separate these states. The hysteresis phenomena were analysed during the transitions between these traffic states. The traffic states and the transitions are represented on a states diagram with the flow axis and the density axis. For motorway sections with ramps the complicated traffic flow is simplified and classified into three traffic states depending on the propagation of congestion. The traffic states are represented on a phase diagram with the upstream demand axis and the interaction strength axis which was defined in this research. The states diagram and the phase diagram provide a basis for the development of the dynamic flow-density relation. The first-order hydrodynamic traffic flow model was programmed according to the cell-transmission scheme extended by the modification of flow dependent sending/receiving functions, the classification of cells and the determination strategy for the flow-density relation in the cells. The unreasonable results of macroscopic traffic flow models, which may occur in the first and last cells in certain conditions are alleviated by applying buffer cells between the traffic data and the model. The sending/receiving functions of the cells are determined dynamically based on the classification of the traffic states by employing fuzzy logic and the shock wave theory. The model is extended to describe also the propagation of congestion in the motorway sections with ramps by considering the capacity reduction caused by the interaction between the traffic flow of the mainstream and the ramps. This research represents the potential of the macroscopic traffic flow models for the application to online traffic control systems by applying the dynamic flow-density relation. The new modelling approach alleviates a critical problem, i.e. the parameter calibration problem, of existing traffic flow models. (orig.)

251

Modeling groundwater flow in highly saline aquifers considering geochemical processes that modify the aquifer's physical properties  

Science.gov (United States)

In the Atacama salt flat, northern Chile, field data indicate that the main aquifer presents a mineralogical zoning consisting of carbonates, sulfates and halite, which is a result of precipitation and/or dissolution reactions. When precipitation and/or dissolution of minerals are active processes in the aquifer, physical properties that control groundwater flow, such as porosity and permeability, would also change. This study investigated the importance of incorporating the impact of mineral precipitation/dissolution on aquifer's physical properties and flow patterns. To this end, the SHEMAT code was utilized to develop a two-dimensional groundwater flow numerical model in the eastern border of the Atacama salt flat. The SHEMAT code solves the classic groundwater flow equation coupled to the reactive transport of ions and mineral precipitation, with variable density, viscosity, porosity and permeability. When geochemical processes were included in the simulations, the model reproduced reasonably well the mineral zoning evidenced by field observations. Mineral precipitation was responsible of a strong permeability reduction in areas of the aquifer associated with halite and calcite formation. Permeability alterations were responsible of changes in the hydraulic head that resulted in significant flow pattern variations compared to variable-density flow models. These results highlight the importance of considering geochemical processes that modify the aquifer's physical properties when modeling groundwater flow in highly saline aquifers such as the Atacama salt flat aquifer.

Munoz, J.; Vasquez, C.; Ortiz, C.; Suarez, F. I.

2013-12-01

252

Monitoring the blood coagulation process under various flow conditions with optical coherence tomography.  

Science.gov (United States)

Our previous work demonstrated that an optical coherence tomography (OCT) technique was able to characterize the whole blood coagulation process. The 1/e light penetration depth (d(1/e)) derived from the profiles of reflectance versus depth was developed for detecting the whole blood coagulation process in static state. To consider the effect of blood flow, in the present study, d(1/e) versus time from the coagulating porcine blood circulated in a mock flow loop with various steady laminar flows at mean flow speed in the range from 5 to 25??mm/s. The variation of d(1/e) was used to represent the change of blood properties during coagulation in different hematocrits (HCT) ranging from 25% to 55%, velocities from 5 to 25??mm/s, and tubing sizes from 0.9 to 2 mm. The results showed that there were positive correlations between coagulation time (t(c)) and HCT, velocity, and tubing size, respectively. In addition, the coagulation rate (S(r)) was decreased with the increase of HCT, velocity, and tubing size. This study testified that HCT, flow velocity, and tubing size were substantial factors affecting the backscattering properties during flowing blood coagulation. Furthermore, OCT has the potential to represent the process of flowing blood coagulation with proper parameters. PMID:24781589

Xu, Xiangqun; Geng, Jinhai; Teng, Xiangshuai

2014-04-01

253

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

254

Primitive phase diagram for hydrogen  

International Nuclear Information System (INIS)

Using a combination of experimental data, empirical rules and extrapolation formula, plus first principles theory, the major phase boundaries are drawn in the phase diagram of hydrogen. The relevance to laser fusion is briefly referred to. (Auth.)

255

Second report on sintering diagrams  

Energy Technology Data Exchange (ETDEWEB)

Sintering-mechanism diagrams are diagrams with axes of neck-size or density, and temperature, which identify the fields of dominance of each of the several mechanisms which contribute to sintering, and show the rate or extent of sintering that all the mechanisms, acting together, produce. The present paper incorporates certain new ideas about sintering into the diagrams: the coupling of boundary diffusion and surface diffusion; new criteria for the stages of sintering; and an approximate treatment of particle rearrangement. Diagrams showing how both the neck size and the density of compacts of wires and of spheres change with time and temperature are developed. Their use is illustrated by an analysis of a large body of sintering data for both wires and spheres of Ag, Cu, Ni, Fe, W, NaCl and Stainless Steel.

Swinkels, F.B.; Ashby, M.F.

1980-04-01

256

Sediment Supply and Transport Processes in the Initiation Area of Debris Flows, Ohya Landslide, Japan  

Science.gov (United States)

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

257

IT-0001-P1 - caHUB Candidate and Specimen Data Entry Process Flow  

Science.gov (United States)

caHUB Candidate and Specimen Data Entry Process Flow BSS Data Entry Personnel BSS Collection & Shipment Bio4D Software at CBR CDR Processing Facility (e.g., Brain Bank, CBR, LDACC) Biospecimen Collection & Case Creation Final Data Entry Preconditions Collect

258

Sheaf cohomology in twistor diagrams  

Digital Repository Infrastructure Vision for European Research (DRIVER)

?One of the earlier achievements of twistor theory was the description of free zero rest mass fields on complexified Minkowski space in terms of holomorphic functions on twistor space. Interactions between these fields are given by certain spacetime integrals (represented by Feynmann diagrams), and some of these integrals have been translated into contour integrals in products of twistor spaces (represented by twistor diagrams). The principal advantage of the twistor...

Huggett, S. A.; Penrose, Roger; Roger Penrose

1980-01-01

259

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

260

The Physical Flow of Materials and the Associated Costs in the Production Process of a Rolling Mill  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Efficiency of resources use is, in a large extent, determined by the organization of production flow and the way of their control. The optimization of materials flow in the production process requires the identification of physical flows of goods and it cost. In the article the physical flow process of materials stream in the production process in one of Polish rolling mill and also its logistics analysis and cost analysis are presented.

Holisz-burzyn?ska, J.; Staniewska, E.; Budzik, R.

2007-01-01

 
 
 
 
261

The Physical Flow of Materials and the Associated Costs in the Production Process of a Rolling Mill  

Directory of Open Access Journals (Sweden)

Full Text Available Efficiency of resources use is, in a large extent, determined by the organization of production flow and the way of their control. The optimization of materials flow in the production process requires the identification of physical flows of goods and it cost. In the article the physical flow process of materials stream in the production process in one of Polish rolling mill and also its logistics analysis and cost analysis are presented.

Holisz-Burzy?ska, J.

2007-01-01

262

Online traffic flow model applying dynamic flow-density relation  

CERN Document Server

This dissertation describes a new approach of the online traffic flow modelling based on the hydrodynamic traffic flow model and an online process to adapt the flow-density relation dynamically. The new modelling approach was tested based on the real traffic situations in various homogeneous motorway sections and a motorway section with ramps and gave encouraging simulation results. This work is composed of two parts: first the analysis of traffic flow characteristics and second the development of a new online traffic flow model applying these characteristics. For homogeneous motorway sections traffic flow is classified into six different traffic states with different characteristics. Delimitation criteria were developed to separate these states. The hysteresis phenomena were analysed during the transitions between these traffic states. The traffic states and the transitions are represented on a states diagram with the flow axis and the density axis. For motorway sections with ramps the complicated traffic fl...

Kim, Y

2002-01-01

263

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

264

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

265

Investigation of Multiscale and Multiphase Flow, Transport and Reaction in Heavy Oil Recovery Processes  

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

266

Investigation of Multiscale and Multiphase Flow, Transport and Reaction in Heavy Oil Recovery Processes  

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

267

The time course of information extraction from instructional diagrams.  

Science.gov (United States)

This study investigated which information is extracted from a brief glance at an instructional diagram to assess its possible contribution for learning with text and diagrams. An experimental paradigm from scene perception research was used to study diagrams. University students (N = 20) saw pictures showing a scene or instructional diagrams for four different presentation times (50 msec. vs 250 msec. vs 1,000 msec. vs 3,000 msec.). Following presentation of a picture or diagram, respectively, participants were asked to verify a statement about its gist, details, and the functioning (for diagrams only). Repeated-measures analyses of variance (ANOVAs) were used to analyze verification accuracy for statements about gist, details, and the functioning as well as the eye movements (i.e., fixation durations and saccade amplitudes) during picture inspection. In both scenes and instructional diagrams, gist but not details were accurately identified from a first glance at the picture (i.e., at 50 msec. and 250 msec.). In contrast, verification accuracy for gist and details increased at a slower rate in instructional diagrams than in scene pictures over presentation times. Moreover, the characteristic function of increasing fixation durations with increasing inspection time was found in scenes, but not in instructional diagrams. Taken together, results suggest that both types of illustrations are processed differently at longer inspection times; however, patterns of early information extraction are similar, namely that the gist but far less information about details is extracted. Results imply people are able to extract an instructional diagram's global spatial structure from a first glance, which may be helpful to learning from text. PMID:23409583

Eitel, Alexander; Scheiter, Katharina; Schüler, Anne

2012-12-01

268

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

Science.gov (United States)

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

269

Flow regime analyses during the filling stage in powder metallurgy processes: experimental study and numerical modelling  

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

270

Investigation of the free flow electrophoretic process. Volume 1: Executive summary  

Science.gov (United States)

The effect of gravity on the free flow electrophoretic process was investigated. The demonstrated effects were then compared with predictions made by mathematical models. Results show that the carrier buffer flow was affected by gravity induced thermal convection and that the movement of the separating particle streams was affected by gravity induced buoyant forces. It was determined that if gravity induced buoyant forces were included in the mathematical models, then effective predictions of electrophoresis chamber separation performance were possible.

Weiss, R. A.; Lanham, J. W.; Richman, D. W.; Walker, C. D.

1979-01-01

271

Application of radioisotope techniques to control flow process during artificial coastal aquifer recharge  

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)

272

Asteroseismic diagrams for solar-type stars  

CERN Document Server

We explore the feasibility of applying the Christensen-Dalsgaard diagram to real asteroseismic data and provide quantitative measures of the uncertainty associated with the results. We also propose a new kind of seismic diagram, based on the determination of the locations of sharp acoustic features inside a star. We show that by combining the information about the position of the base of the convective envelope or the HeII ionisation zone with a measure of the average large separation, it is possible to constrain the unknown chemical composition or the various parameters characterising the physical processes in the stellar interior. We demonstrate the application of this technique to the analysis of mock data for a CoRoT target star.

Mazumdar, A

2005-01-01

273

Processes Controlling Stream Flow Chemistry in Semiarid, Forested Catchments, Valles Caldera, New Mexico  

Science.gov (United States)

Using mixing models and point and spatially distributed snow data, controls of stream flow chemistry from headwaters to higher order streams at the East Fork of the Jemez River were identified. The East Fork of the Jemez River, located in Valles Caldera in New Mexico, drains a total area of 1400 km2 and is primarily characterized by highly fractured tuff. Chemical data were collected from 2005 to 2007 from tributaries of the East Fork of Jemez River. Remotely sensed snow-covered area (SCA) data from MODIS were also used to determine snowmelt timing, estimate snowmelt quantity and help understand stream flow generation in these ungaged catchments. A new modeling procedure was developed to identify conservative chemical tracers and end-members contributing to stream flow using diagnostic tools of mixing models and end-member mixing analysis. Results indicate that stream flow chemistry is primarily controlled by mixing of shallow subsurface flow and groundwater (overland flow and in-stream chemical reactions are not important). From smaller to larger catchments, the number of end-members does not change, but chemical compositions of those end-members change with catchment size, slope and snow water equivalent. This new modeling tool set may be used elsewhere to examine processes controlling stream flow chemistry and the changes of stream flow chemistry with catchment characteristics.

Liu, F.; Parmenter, B. R.; Brooks, P. D.; Conklin, M. H.; Bales, R. C.

2007-12-01

274

Some Aspects of Improving Initial Filling Conditions and Steel Cleanliness by Flow Pattern Control Using a Swirling Flow in the Uphill Teeming Process  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The flow pattern has widely been recognized to have an impact on the exogenous non-metallic inclusion generation in the gating system and mold flux entrapment in the uphill teeming process. Thus, a well-controlled flow pattern during the teeming process can improve the quality of ingots and further increase the yield during steel production. The current study focused on investigating and optimizing the flow pattern of steel in the gating system and molds to improve steel cleanliness during th...

Tan, Zhe

2013-01-01

275

Using turbine expanders to recover exothermic reaction heat--flow sheet development for typical chemical processes  

International Nuclear Information System (INIS)

The integration of a turbine expander into different types of high pressure, exothermic chemical synthesis processes is considered. In conventional systems, the reaction heat is often transferred to generate steam to drive steam turbines or used for heat integration. The heat is reduced in quality due to the temperature driving forces in the heat exchange equipment. Reaction heat can be utilised at the maximum possible temperature by placing a turbine expander directly after the reactor. The power generated from such combined power and chemical systems can either be exported or used to satisfy the process compressor requirements. A methodology is presented to lend structure to the development and analysis of the flow sheets for the mentioned systems. The methodology involves the consideration of various factors that were identified to impact on the flow sheet development. These factors are discussed and a brief overview of the flow sheet development for four different case studies is given. Process data generated from simulations are used

276

Using turbine expanders to recover exothermic reaction heat--flow sheet development for typical chemical processes  

Energy Technology Data Exchange (ETDEWEB)

The integration of a turbine expander into different types of high pressure, exothermic chemical synthesis processes is considered. In conventional systems, the reaction heat is often transferred to generate steam to drive steam turbines or used for heat integration. The heat is reduced in quality due to the temperature driving forces in the heat exchange equipment. Reaction heat can be utilised at the maximum possible temperature by placing a turbine expander directly after the reactor. The power generated from such combined power and chemical systems can either be exported or used to satisfy the process compressor requirements. A methodology is presented to lend structure to the development and analysis of the flow sheets for the mentioned systems. The methodology involves the consideration of various factors that were identified to impact on the flow sheet development. These factors are discussed and a brief overview of the flow sheet development for four different case studies is given. Process data generated from simulations are used.

Greeff, I.L.; Visser, J.A.; Ptasinski, K.J.; Janssen, F.J.J.G

2004-12-01

277

Using turbine expanders to recover exothermic reaction heat-flow sheet development for typical chemical processes  

Energy Technology Data Exchange (ETDEWEB)

The integration of a turbine expander into different types of high pressure, exothermic chemical synthesis processes is considered. In conventional systems, the reaction heat is often transferred to generate steam to drive steam turbines or used for heat integration. The heat is reduced in quality due to the temperature driving forces in the heat exchange equipment. Reaction heat can be utilised at the maximum possible temperature by placing a turbine expander directly after the reactor. The power generated from such combined power and chemical systems can either be exported or used to satisfy the process compressor requirements. A methodology is presented to lend structure to the development and analysis of the flow sheets for the mentioned systems. The methodology involves the consideration of various factors that were identified to impact on the flow sheet development. These factors are discussed and a brief overview of the flow sheet development for four different case studies is given. Process data generated from simulations are used. (author)

Greeff, I.L.; Visser, J.A. [University of Pretoria (South Africa). Department of Mechanical Engineering; Ptasinski, K.J.; Janssen, F.J.J.G. [Eindhoven University of Technology (Netherlands). Department of Chemical Engineering

2002-12-01

278

Real-time blood flow visualization using the graphics processing unit  

Science.gov (United States)

Laser speckle imaging (LSI) is a technique in which coherent light incident on a surface produces a reflected speckle pattern that is related to the underlying movement of optical scatterers, such as red blood cells, indicating blood flow. Image-processing algorithms can be applied to produce speckle flow index (SFI) maps of relative blood flow. We present a novel algorithm that employs the NVIDIA Compute Unified Device Architecture (CUDA) platform to perform laser speckle image processing on the graphics processing unit. Software written in C was integrated with CUDA and integrated into a LabVIEW Virtual Instrument (VI) that is interfaced with a monochrome CCD camera able to acquire high-resolution raw speckle images at nearly 10 fps. With the CUDA code integrated into the LabVIEW VI, the processing and display of SFI images were performed also at ~10 fps. We present three video examples depicting real-time flow imaging during a reactive hyperemia maneuver, with fluid flow through an in vitro phantom, and a demonstration of real-time LSI during laser surgery of a port wine stain birthmark.

Yang, Owen; Cuccia, David; Choi, Bernard

2011-01-01

279

Simulation based flow distribution network optimization for vacuum assisted resin transfer moulding process  

Science.gov (United States)

In the vacuum assisted resin transfer moulding (VARTM) process, using a flow distribution network such as flow channels and high permeability fabrics can accelerate the resin infiltration of the fibre reinforcement during the manufacture of composite parts. The flow distribution network significantly influences the fill time and fill pattern and is essential for the process design. The current practice has been to cover the top surface of the fibre preform with the distribution media with the hope that the resin will flood the top surface immediately and penetrate through the thickness. However, this approach has some drawbacks. One is when the resin finds its way to the vent before it has penetrated the preform entirely, which results in a defective part or resin wastage. Also, if the composite structure contains ribs or inserts, this approach invariably results in dry spots. Instead of this intuitive approach, we propose a science-based approach to design the layout of the distribution network. Our approach uses flow simulation of the resin into the network and the preform and a genetic algorithm to optimize the flow distribution network. An experimental case study of a co-cured rib structure is conducted to demonstrate the design procedure and validate the optimized flow distribution network design. Good agreement between the flow simulations and the experimental results was observed. It was found that the proposed design algorithm effectively optimized the flow distribution network of the part considered in our case study and hence should prove to be a useful tool to extend the VARTM process to manufacture of complex structures with effective use of the distribution network layup.

Hsiao, Kuang-Ting; Devillard, Mathieu; Advani, Suresh G.

2004-05-01

280

Hybrid modeling of convective laminar flow in a permeable tube associated with the cross-flow process  

Science.gov (United States)

The confined flows in tubes with permeable surfaces are associated to tangential filtration processes (microfiltration or ultrafiltration). The complexity of the phenomena do not allow for the development of exact analytical solutions, however, approximate solutions are of great interest for the calculation of the transmembrane outflow and estimate of the concentration polarization phenomenon. In the present work, the generalized integral transform technique (GITT) was employed in solving the laminar and permanent flow in permeable tubes of Newtonian and incompressible fluid. The mathematical formulation employed the parabolic differential equation of chemical species conservation (convective-diffusive equation). The velocity profiles for the entrance region flow, which are found in the connective terms of the equation, were assessed by solutions obtained from literature. The velocity at the permeable wall was considered uniform, with the concentration at the tube wall regarded as variable with an axial position. A computational methodology using global error control was applied to determine the concentration in the wall and concentration boundary layer thickness. The results obtained for the local transmembrane flux and the concentration boundary layer thickness were compared against others in literature.

Venezuela, A. L.; Pérez-Guerrero, J. S.; Fontes, S. R.

2009-03-01

 
 
 
 
281

Erosion estimation for NPP turbine blades using generalized diagram  

International Nuclear Information System (INIS)

Generalized data on estimation criteria of erosion fracture used with various plants and companies are given as well as a generalized diagram for determining erosion characteristics of a stage on partial loads. An example of using the generalized diagram for determining relative change in unloading range of NPP powerful turbine depending on humidity at the end of the steam expansion process and reserve for admissible erosion is given

282

An Approach to Code Generation from UML Diagrams  

Directory of Open Access Journals (Sweden)

Full Text Available The Unified Modeling Language (UML has now become the de-facto industry standard for object-oriented (OO software development. UML provides a set of diagrams to model structural and behavioral aspects of an object-oriented system. Automatic translation of UML diagrams to object oriented code is highly desirable because it eliminates the chances of introduction of human errors in the translation process. Automatic code generation is efficient which, in turn, helps the software engineers deliver the software on time. However, major challenges in this area include checking consistency of UML models, and ensuring accuracy, maintainability, and efficiency of the generated code. This paper represents an approach to generate efficient and compact executable code from UML diagram. By analyzing the characteristics UML diagram, a coding strategy is proposed, and a structure identification and coding algorithm are put forward for code generation from UML diagram. Based on the coding strategy an algorithm is proposed to generate code from UML diagrams using some intermediate steps. The main objective of this paper is to generate the code from UML diagram.

Harshal D. Gurad

2014-01-01

283

Jerarquización no paramétrica en procesos caracterizados por múltiples indicadores, mediante diagramas de HASSE y conjuntos parcialmente ordenados: Aplicaciones en ingeniería / Non-parametric ranking in multi-indicator processes using HASSE diagrams and partially ordered sets: Enineering applicarions  

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.

284

Quantitative analysis of flow processes in a sand using synchrotron-based X-ray microtomography  

DEFF Research Database (Denmark)

Pore-scale multiphase flow experiments were developed to nondestructively visualize water flow in a sample of porous material using X-ray microtomography. The samples were exposed to similar boundary conditions as in a previous investigation, which examined the effect of initial flow rate on observed dynamic effects in the measured pressure-saturation curves; a significantly higher residual and higher capillary pressures were found when the sample was drained fast using a high air-phase pressure. Prior work applying the X-ray microtomography technique to pore-scale multiphase flow problems has been of a mostly qualitative nature and no experiments have been presented in the existing literature where a truly quantitative approach to investigating the multiphase flow process has been taken, including a thorough image-processing scheme. The tomographic images presented here show, both by qualitative comparison and quantitative analysis in the form of a nearest neighbor analysis, that the dynamic effects seen in previous experiments are likely due to the fast and preferential drainage of large pores in the sample. Once a continuous drained path has been established through the sample, further drainage of the remaining pores, which have been disconnected from the main flowing water continuum, is prevented.

Wildenschild, Dorthe

2005-01-01

285

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

286

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

287

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

288

Studies of thermohydrologic flow processes using TOUGH2. Yucca Mountain Site Characterization Project  

International Nuclear Information System (INIS)

Coupled thermal and hydrologic flow processes have been recognized as important factors in the evaluation of Yucca Mountain as a potential repository for high-level radioactive wastes. As a result, several models and numerical codes such as TOUGH2 have been used to investigate the thermohydrologic conditions near a potential nuclear waste repository. However, very few of these models have been tested through laboratory or field scale studies. This work has therefore focused on modeling well-controlled experiments of non-isothermal flow processes in porous media at different scales to serve two primary objectives: (1) identify processes that are potentially important to thermal and hydrologic transport at Yucca Mountain and (2) build confidence in models and codes through combined experimental and numerical studies of thermohydrologic behavior at different scales and conditions. In this report, three independent studies of thermohydrologic flow processes at laboratory and field scales are presented. The experiments and field studies that are presented here were performed independently of this work. The main focus of this report was to use the numerical code TOUGH2 to simulate the non-isothermal flow behavior observed in each experiment to generate understanding of the thermohydrologic processes and to gain confidence in the code. TOUGH2 was chosen due to its current use in calculations associated with Yucca Mountain and its capability of modeling the coupled transport ability of modeling the coupled transport of air, water, vapor, and heat in porous media

289

Geo-Hydro Statistical Characterization of Preferential Flow and Transport Processes in Karst Groundwater Systems  

Science.gov (United States)

Karst groundwater systems are highly productive and provide an important fresh water resource for human development and ecological integrity. Their high productivity is often associated with conduit flow and high matrix permeability. The same characteristics that make these aquifers productive also make them highly vulnerable to contamination and a likely for contaminant exposure. Of particular interest are chlorinated organic contaminants and phthalates derived from industrial solvents and plastic by-products. These chemicals have been identified as potential precursors of pre-term birth, a leading cause of neonatal complications with a significant health and societal cost. The general objectives of this work are to: (1) develop fundamental knowledge and determine the processes controlling the release, mobility, persistence, and possible pathways of contaminants in karst groundwater systems, and (2) characterize transport processes in conduit and diffusion-dominated flow under base flow and storm flow conditions. The work presented herein focuses on the development of geo-hydro statistical tools to characterize flow and transport processes under different flow regimes. Multidimensional, laboratory-scale Geo-Hydrobed models were developed and tested for this purpose. The models consist of stainless-steel tanks containing karstified limestone blocks collected from the karst aquifer formation of northern Puerto Rico. The models a network of sampling wells to monitor flow, pressure, and solute concentrations temporally and spatially. Experimental work entailed making a series of point injections in wells while monitoring the hydraulic response in other wells. Statistical mixed models were applied to spatial probabilities of hydraulic response and weighted injected volume data, and were used to determinate the best spatial correlation structure to represent paths of preferential flow in the limestone units under different groundwater flow regimes. Preliminary testing of the karstified models show that the system can be used to represent the variable transport regime characterized by conduit and diffuses flow in the karst systems. Initial hydraulic characterization indicates a highly heterogeneous system resulting in large preferential flow components. Future works involve characterization of dual porosity system using conservative tracers, fate and transport experiments using phthalates and chlorinated solvents, geo-temporal statistical modeling, and the testing of "green" remediation technologies in karst groundwater. This work is supported by the U.S. Department of Energy, Savannah River (Grant Award No. DE-FG09-07SR22571), and the National Institute of Environmental Health Sciences (NIEHS, Grant Award No. P42ES017198).

Anaya, A. A.; Padilla, I. Y.; Macchiavelli, R. E.

2011-12-01

290

Numerical Analysis of the Molten Steel Flow Consider Solidification at the Continuous Casting Process  

International Nuclear Information System (INIS)

Continuous casting process is widely used for making mid stage of manufactured steel product. Characteristics of steel flow in the mold is very important for mold design and SEN(Submerged Entry Nozzle) and using CFD analysis, numerical approach to molten steel flow can be very useful in understanding its flow characteristics in the mold and also make us easily understand growing of solidification shell thickness near mold wall. This study was done for predicting solidification shell thickness in the beam blank model for continuous casting of steel, using commercial FVM Cartesian Solver, STREAM V6. For considering turbulent flow, the low Reynolds number ?-? model was used. Solidification of molten steel is calculated through the temperature recovery method. And this solidification model was also applied to benchmark cases for validating with experimental and numerical results of other researchers

291

Aerodynamic study on supersonic flows in high-velocity oxy-fuel thermal spray process  

Science.gov (United States)

To clarify the characteristics of gas flow in high velocity oxy-fuel (HVOF) thermal spray gun, aerodynamic research is performed using a special gun. The gun has rectangular cross-sectional area and sidewalls of optical glass to visualize the internal flow. The gun consists of a supersonic nozzle with the design Mach number of 2.0 followed by a straight passage called barrel. Compressed dry air up to 0.78 MPa is used as a process gas instead of combustion gas which is used in a commercial HVOF gun. The high-speed gas flows with shock waves in the gun and jets are visualized by schlieren technique. Complicated internal and external flow-fields containing various types of shock wave as well as expansion wave are visualized.

Katanoda, Hiroshi; Matsuoka, Takeshi; Kuroda, Seiji; Kawakita, Jin; Fukanuma, Hirotaka; Matsuo, Kazuyasu

2005-06-01

292

The penguin diagram and the process ????  

International Nuclear Information System (INIS)

It is pointed out that the ''penguin''-contribution is the only part of the standard ?S=1 weak Hamiltonian which contributes to the decay modes ?-??-? and ?-??-?. These decay modes could therefore potentially be good tests of the coefficients of the ''penguin' operators. Matrix elements of the weak Hamiltonian between baryon states are estimated within a quark model (mainly the bag model). The theoretical predictions for the branching ratios are found to be uncertain. But the analysis indicates that Br(?-??-?) approximately 10-5 to 10-4 and Br(?-??-?) approximately 10-6 to 10-5. (Auth.)

293

Phase diagrams and crystal growth  

Science.gov (United States)

Phase diagrams are briefly treated as generalized property-composition relationships, with respect to crystal technology optimization. The treatment is based on mutual interaction of three systems related to semiconductors: (a) the semiconducting material systems, (b0 the data bank, (c) the system of crystallization methods. A model is proposed enabling optimatization on the path from application requirements to the desired material. Further, several examples of the selection as to the composition of LED and laser diode material are given. Some of molten-solution-zone methods are being successfully introduced for this purpose. Common features of these methods, the application of phase diagrams, and their pecularities compared with other crystallization methods are illustrated by schematic diagrams and by examples. LPE methods, particularly the steady-state LPE methods such as Woodall's ISM and Nishizawa's TDM-CVP, and the CAM-S (Crystallization Method Providing Composition Autocontrol in Situ) have been chosen as examples. Another approach of exploiting phase diagrams for optimal material selection and for determination of growth condition before experimentation through a simple calculation is presented on InP-GaP solid solutions. Ternary phase diagrams are visualized in space through calculation and constructions based on the corresponding thermodynamic models and anaglyphs. These make it easy to observe and qualitatively analyze the crystallization of every composition. Phase diagrams can be also used as a powerful tool for the deduction of new crystallization methods. Eutectic crystallization is an example of such an approach where a modified molten-solution-zone method can give a sandwich structure with an abrupt concentration change. The concentration of a component can range from 0 to 100% in the different solid phases.

Venkrbec, Jan

1980-04-01

294

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.; Sum, Amadeu K.; Koh, Carolyn A.

2010-01-01

295

Velocity measurement of three-dimensional flow around rotating parallel disks by digital image processing  

International Nuclear Information System (INIS)

This paper reports a quantitative multi-point velocity measurement system, which is based on particle tracking with the digital image processing technique, which has been developed for analyzing a three-dimensional unsteady flow field. The measurement system consists of two TV cameras, a digital image processor interfaced with personal computer and originally developed algorithm for three dimensional particle tracking. The particles injected into a complex flow field are tracked consecutively, by using the image processing technique which combined with stereo photogrammetry, and three dimensional velocities are automatically calculated. The present method was applied to three-dimensional measurement of swirling flow around or between a rotating coaxial parallel disks. Nearly 5000 instantaneous velocity vectors were extracted from sets of 100 consecutive images and cross-sectional velocity profiles and angular velocity profiles between disks were calculated from these velocity data. The measurement uncertainty involved in the measurement results was about 8%

296

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.

297

Functional correlates of optic flow motion processing in Parkinson’s disease  

Directory of Open Access Journals (Sweden)

Full Text Available The visual input created by the relative motion between an individual and the environment, also called optic flow, influences the sense of self-motion, postural orientation, veering of gait, and visuospatial cognition. An optic flow network comprising visual motion areas V6, V3A, and MT+, as well as visuo-vestibular areas including posterior insula vestibular cortex (PIVC and cingulate sulcus visual area (CSv, has been described as uniquely selective for parsing egomotion depth cues in humans. Individuals with Parkinson's disease (PD have known behavioral deficits in optic flow perception and visuospatial cognition compared to age- and education-matched control adults (MC. The present study used functional magnetic resonance imaging to investigate neural correlates related to impaired optic flow perception in PD. We conducted fMRI on 40 non-demented participants (23 PD and 17 MC during passive viewing of simulated optic flow motion and random motion. We hypothesized that compared to the MC group, PD participants would show abnormal neural activity in regions comprising this optic flow network. MC participants showed robust activation across all regions in the optic flow network, consistent with studies in young adults, suggesting intact optic flow perception at the neural level in healthy aging. PD participants showed diminished activity compared to MC particularly within visual motion area MT+ and the visuo-vestibular region CSv. Further, activation in visuo-vestibular region CSv was associated with disease severity. These findings suggest that behavioral reports of impaired optic flow perception and visuospatial performance may be a result of impaired neural processing within visual motion and visuo-vestibular regions in PD.

DeeptiPutcha

2014-07-01

298

In-process measurement of polymer melt flow in extrusion process  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Extrusion-based in-process rheometry was carried using a specially designed capillary extrusion die, fitted to a single screw extruder with a screw of 25:1 L/D ratio. A pressure transducer and a thermocouple were attached to the extrusion die. Processing parameters in terms of pressure drop across capillary channel and melt temperature were captured by means of a data acquisition system. Shear properties were quantified using rheometric equations. Baglay corections were made for all sets of d...

Charoen Nakason; Sarote Changchum; Manus Saedan

2000-01-01

299

Gaia Data Flow System (GDFS) Project: the UK's contribution to Gaia data processing  

Science.gov (United States)

Gaia is an ESA cornerstone mission which will observe some billion stars in the galaxy enabling micro-arcsec astrometric catalogues to be constructed. In addition Gaia will produce high quality photometric and spectroscopic catalogues. The data processing tasks are large and complex. A European consortium has been formed - the Gaia Data Processing and Analysis Consortium (DPAC). This paper describes the form of the UK Gaia Data Flow System Project contribution to the DPAC.

Walton, N. A.; Cropper, M.; Gilmore, G.; Irwin, M.; van Leeuwen, F.

2008-07-01

300

OP-0008-P1 GTEx Deidentified Data Export Brain Bank Process Flow  

Science.gov (United States)

GTEx De-identified Data Export Process Flow LDACC Study Management Group BSS BB PM validates correction BB receives/ reviews report CDR Review data in CDR Identify/ resolve discrepencies Error in Bio4D? DCF SOP Correction Valid? DM Sends manual

 
 
 
 
301

Solid gas reaction phase diagram under high gas pressure  

International Nuclear Information System (INIS)

This paper reports that to evaluate which are the stable phases under high gas pressure conditions, a solid-gas reaction phase diagram under high gas pressure (HIP phase diagram) has been proposed by the author. The variables of the diagram are temperature, reactant gas partial pressure and total gas pressure. Up to the present time the diagrams have been constructed using isobaric conditions. In this work, the stable phases for a real HIP process were evaluated assuming an isochoric condition. To understand the effect of the total gas pressure on stability is of primary importance. Two possibilities were considered and evaluated, those are: the total gas pressure acts as an independent variable, or it only affects the fugacity values. The results of this work indicate that the total gas pressure acts as an independent variable, and in turn also affects the fugacity values

302

GIS-based modeling of debris flow processes in an Alpine catchment, Antholz valley, Italy  

Science.gov (United States)

Debris flows are frequent natural hazards in mountain regions, which seriously can threat human lives and economic values. In the European Alps the occurrence of debris flows might even increase with respect to climate change, including permafrost degradation, glacier retreat and variable precipitation patterns. Thus, detailed understanding of process parameters and spatial distribution of debris flows is necessary to take appropriate protection measures for risk assessment. In this context, numerical models have been developed and applied successfully for simulation and prediction of debris-flow hazards and related process areas. In our study a GIS-based model is applied in an alpine catchment to address the following questions: Where are potential initiating areas of debris flows? How much material can be mobilized? What is the influence of topography and precipitation? The study area is located in the Antholz valley in the eastern Alps of Northern Italy. The investigated catchment of the Klammbach creek comprises 6.5 km² and is divided into two sub-catchments. Geologically it is dominated by metamorphic rock and altitudes range between 1310 and 3270 m. In summer 2005 a debris flow of more than 100000 m³ took place, originating from a steep, sparsely vegetated debris cone in the western part of the catchment. According to a regional study, the lower permafrost boundary in this area has risen by 250 m. In a first step, during a field survey, geomorphological mapping was performed, several channel cross-sections were measured and sediment samples were taken. Using mapping results and aerial images, a geomorphological map was created. In further steps, results from the field work, the geomorphological map and existing digital data sets, including a digital elevation model with 2.5 m resolution, are used to derive input data for the modeling of debris flow processes. The model framework ‘r.debrisflow' based on GRASS GIS is applied (Mergili, 2008*), as it is capable of simulating the potential spatial patterns of debris flow deposition, as well as their initiation and movement. Furthermore it is a freely available and opensource software and can thus be improved and extended. ‘r.debrisflow' couples a hydraulic, a slope stability, a sediment transport and a debris flow runout model, which are combined differently in 6 simulation modes. In a first step, model parameters are calibrated using the runout only mode with known parameters of the 2005 debris flow. Finally, the full mode will be used to evaluate the debris-flow potential of the whole catchment. First results from the geomorphological mapping reveal numerous surface forms, like levees, debris flow lobes or scars that indicate past and recent debris flow activity in the area. In both sub-catchments, there are large areas of unconsolidated, sparsely or unvegetated sediments, surrounded by high rock walls, which conduct precipitation rapidly into the debris. The two sub-catchments, however, have different topographic characteristics, which can be analyzed with the model in more detail. In a next step, the potential starting areas of future debris flows shall be identified and the potential amount of mobilized material shall be estimated by the model. *Mergili, M. (2008): Integrated modelling of debris flows with Open Source GIS. Ph.D. thesis. University of Innsbruck. http://www.uibk.ac.at/geographie/personal/mergili/dissertation.pdf

Sandmeier, Christine; Damm, Bodo; Terhorst, Birgit

2010-05-01

303

Neuraminidase Ribbon Diagram  

Science.gov (United States)

Ribbons is a program developed at UAB used worldwide to graphically depict complicated protein structures in a simplified format. The program uses sophisticated computer systems to understand the implications of protein structures. The Influenza virus remains a major causative agent for a large number of deaths among the elderly and young children and huge economic losses due to illness. Finding a cure will have a general impact both on the basic research of viral pathologists of fast evolving infectious agents and clinical treatment of influenza virus infection. The reproduction process of all strains of influenza are dependent on the same enzyme neuraminidase. Shown here is a segmented representation of the neuraminidase inhibitor compound sitting inside a cave-like contour of the neuraminidase enzyme surface. This cave-like formation present in every neuraminidase enzyme is the active site crucial to the flu's ability to infect. The space-grown crystals of neuraminidase have provided significant new details about the three-dimensional characteristics of this active site thus allowing researchers to design drugs that fit tighter into the site. Principal Investigator: Dr. Larry DeLucas

2004-01-01

304

Developing the technique of image processing for the study of bubble dynamics in subcooled flow boiling  

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)

305

Flow Processes in the Dry Regime: The Effect on Capillary Barrier Performance  

Energy Technology Data Exchange (ETDEWEB)

Engineered capillary barriers typically consist of two layers of granular materials designed so that the contrast in material hydraulic properties and sloping interface retains infiltrating water in the upper layer. We report here on the results of two bench-top capillary barrier experiments, interpretation, and numerical modeling. We measured hydraulic parameters for two coarse materials using standard methods and found that the materials had similar hydraulic properties despite being morphologically different (round vs. angular). The round sand provided a better functioning capillary barrier than the angular sand, but neither experiment could be characterized as a perfectly working capillary barrier. In both cases, more than 93% of the infiltrating water was successfully diverted from the lower layer, however, infiltration into the underlying layer was observed in both systems. Based on this work, we believe that non-continuum processes such as vapor diffusion and film flow contribute to the observed phenomena and are important aspects to consider with respect to capillary barrier design, as well as dry vadose zone processes in general. Using a theoretical film flow equation that incorporates the surface geometry of the porous material we found that infiltration into the coarse underlying sand layer appeared to be dominated by water film flow. The NUFT (Non-isothermal Unsaturated-saturated Flow and Transport) model was used for qualitative comparison simulations. We were able to reproduce the barrier breach observed in the experiments using targeted parameter adjustment, by which pseudo-film flow was successfully simulated.

Jansik, Danielle P.; Wildenschild, Dorthe; Rosenberg, Nina D.

2011-11-01

306

A multi-component two-phase flow algorithm for use in landfill processes modelling.  

Science.gov (United States)

This paper describes the finite difference algorithm that has been developed for the flow sub-model of the University of Southampton landfill degradation and transport model LDAT. The liquid and gas phase flow components are first decoupled from the solid phase of the full multi-phase, multi-component landfill process constitutive equations and are then rearranged into a format that can be applied as a calculation procedure within the framework of a three dimensional array of finite difference rectangular elements. The algorithm contains a source term which accommodates the non-flow landfill processes of degradation, gas solubility, and leachate chemical equilibrium, sub-models that have been described in White and Beaven (2013). The paper includes an illustration of the application of the flow sub-model in the context of the leachate recirculation tests carried out at the Beddington landfill project. This illustration demonstrates the ability of the sub-model to track movement in the gas phase as well as the liquid phase, and to simulate multi-directional flow patterns that are different in each of the phases. PMID:24925875

White, J K; Nayagum, D; Beaven, R P

2014-09-01

307

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.)

308

Animated Diagram: Sedimentary Rock Identification  

Science.gov (United States)

This Flash-enabled diagram provides a scheme for sedimentary rock identification accompanied by pop-up images of the rocks. Rolling the mouse over highlighted boxes links texture, grain size, composition, and map symbols to images of a variety of sedimentary rocks. The animation is downloadable.

309

Higher Order City Voronoi Diagrams  

CERN Document Server

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

310

Diagrams in the polaron model  

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

311

Index of Animated Phase Diagrams  

Science.gov (United States)

This is a collection of animated phase diagrams by Kenneth Windom at Iowa State University. These short Power Point animations can be used to illustrate equilibrium crystallization concepts. There are slide shows for plagioclase feldspars (albite and anorthite); forsterite, diopside and anorthite; forsterite, enstatite and silica; and diopside and anorthite.

Windom, Kenneth E.; University, Iowa S.

312

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.)

313

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.

Yili Tan

2012-04-01

314

A Control-flow Pattern based Horizontal Business Process Model Transformation Approach  

Directory of Open Access Journals (Sweden)

Full Text Available Due to company mergers and business to business interoperability, there is a need for model transformations in the area of business process modeling to facilitate scenarios like model integration and model synchronization. General model transformation approaches do not consider the special properties of business process models and horizontal transformation scenarios. Since different business process modeling languages use different modeling elements and syntax constraints, a business process may have very different representations in different languages. So in many cases it is not easy to transform business process models correctly only using an element-2-element mapping. In order to solve this problem and improve the correction rate of horizontal business process model transformation, in this work we propose CP-BPMT(Control-flow Pattern based Business Process Model Transformation, a horizontal business process model transformation approach in which the operation granularity has been increased from model elements to model fragments illustrating certain control-flow patterns. CP-BPMT is feasible in practice and it can generate transformation results better than element-based approaches. In order to illustrate CP-BPMT approach, a UML-AD2YAWL case study is conducted.

Huang Wenqing

2013-01-01

315

A practical guide to Feynman diagrams  

International Nuclear Information System (INIS)

These lectures serve as an introduction to the basic ideas of relativistic quantum theory, perturbation theory and the Feynman diagram calculus, in the context of electromagnetic interactions. The main objective is to get the student as rapidly as possible to the point where he can calculate the lowest order cross-sections for a variety of two-body electromagnetic processes. The techniques are considered under the headings: relativistic wave equations, electrodynamics of spinless particles, and electrodynamics of spin-1/2 particles. A selection of problems and exercises is included. (U.K.)

316

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

317

A Thermodynamic Hypothesis to Reconcile Optimality Principles for Flow Processes in Geosystems  

CERN Document Server

This letter proposes a new thermodynamic hypothesis that states that an open and nonlinear natural system, involving positive feedbacks, tends to minimize its resistance to the flow process through it that is imposed by its environment. It allows for a straightforward reconciliation of the two well-known and seemingly inconsistent optimality principles: the minimization of the energy expenditure rate for a river basin, and the maximization of entropy production in the Earth-atmosphere system. We also demonstrate that the hypothesis is consistent with water flow behavior in saturated and unsaturated porous media.

Liu, Hui-Hai

2013-01-01

318

Simulation of the physicochemical processes of erosion-corrosion of metals in two-phase flows  

International Nuclear Information System (INIS)

One elaborated calculation model of erosion-corrosion (RAMEK-2) of power equipment metals in two-phase flows. Paper presents in three-dimensional representation the calculation results of dependence of intensity of structural steel erosion-corrosion on thermodynamic, hydrodynamic and water-chemistry parameters of those flows in process channels of TEPPs and NPPs. On the basis of mathematical model one elaborated software enabling to predict erosion-corrosion life and to optimize regulations for diagnostics and preventive measures of erosion-corrosion of power plant moist steam channel elements

319

Investigation of hydrogeologic processes in a dipping layer structure: 1. The flow barrier effect.  

Science.gov (United States)

Numerical simulations of a field experiment were performed in order to study the processes contributing to lateral diversion of water flow in the unsaturated zone. The experimental site is a glacial delta with dipping layers of alternating finer and coarser sand. Model soil physical parameters for each of the stratigraphic layers were estimated from soil grain size distributions. Anisotropy of the hydraulic conductivity within the layers was critical in order to reproduce the flow pattern observed in the experiment. Capillary and hydraulic barriers were of minor importance for the observed lateral diversion. PMID:15028389

Alfnes, E; Kinzelbach, W; Aagaard, P

2004-04-01

320

Conservação e reúso de águas usando o método Diagrama de Fontes de Água para processos em batelada: estudo de casos / Water conservation and reuse using the Water Sources Diagram method for batch process: case studies  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese O gerenciamento de recursos hídricos tem sido um fator importante para a sustentabilidade dos processos industriais, visto que há uma necessidade crescente pelo desenvolvimento de metodologias voltadas para conservação e uso racional da água. O objetivo deste trabalho foi aplicar o método Diagrama d [...] e Fontes de Água (DFA), usado na definição de metas de mínimo consumo de água, a processos que operam em regime batelada. Foram gerados e avaliados cenários de reúso de correntes obtidos pela aplicação do método a partir de dados de quantidade de água e concentração de contaminantes nas operações. Foram apresentados dois estudos de caso com o objetivo de demonstrar a redução de consumo de água e da geração de efluentes, além de custos de tratamento final e de investimento em tanques de estocagem, em relação à configuração inicial. Os cenários mostraram-se bastante promissores, com reduções que alcançam 45%, em termos de consumo hídrico e geração de efluentes, e 37%, em termos de custos de tanques, sem a necessidade de processos de regeneração. Com isso, a técnica empregada mostrou-se relevante e flexível como alternativa às ferramentas sistemáticas voltadas para a minimização do consumo de água em processos industriais, exercendo importante papel em um programa de gerenciamento de recursos hídricos. Abstract in english The water resources management has been an important factor for the sustainability of industrial processes, since there is a growing need for the development of methodologies aimed at the conservation and rational use of water. The objective of this work was to apply the heuristic-algorithmic method [...] called Water Sources Diagram (WSD), which is used to define the target of minimum water consumption, to batch processes. Scenarios with reuse of streams were generated and evaluated with application of the method from the data of water quantity and concentration of contaminants in the operations. Two case studies aiming to show the reduction of water consumption and wastewater generation, and final treatment costs besides investment in storage tanks, were presented. The scenarios showed great promising, achieving reduction up to 45% in water consumption and wastewater generation, and a reduction of around 37% on cost of storage tanks, without the need to allocate regeneration processes. Thus, the WSD method showed to be a relevant and flexible alternative regarding to systemic tools aimed at minimizing the consumption of water in industrial processes, playing an important role within a program of water resources management.

Reinaldo Coelho, Mirre; Shaula Christine Leal, Ferreira; Aline Rodrigues, Dias; Fernando Luiz Pellegrini, Pessoa.

2012-03-01

 
 
 
 
321

Conservação e reúso de águas usando o método Diagrama de Fontes de Água para processos em batelada: estudo de casos / Water conservation and reuse using the Water Sources Diagram method for batch process: case studies  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese O gerenciamento de recursos hídricos tem sido um fator importante para a sustentabilidade dos processos industriais, visto que há uma necessidade crescente pelo desenvolvimento de metodologias voltadas para conservação e uso racional da água. O objetivo deste trabalho foi aplicar o método Diagrama d [...] e Fontes de Água (DFA), usado na definição de metas de mínimo consumo de água, a processos que operam em regime batelada. Foram gerados e avaliados cenários de reúso de correntes obtidos pela aplicação do método a partir de dados de quantidade de água e concentração de contaminantes nas operações. Foram apresentados dois estudos de caso com o objetivo de demonstrar a redução de consumo de água e da geração de efluentes, além de custos de tratamento final e de investimento em tanques de estocagem, em relação à configuração inicial. Os cenários mostraram-se bastante promissores, com reduções que alcançam 45%, em termos de consumo hídrico e geração de efluentes, e 37%, em termos de custos de tanques, sem a necessidade de processos de regeneração. Com isso, a técnica empregada mostrou-se relevante e flexível como alternativa às ferramentas sistemáticas voltadas para a minimização do consumo de água em processos industriais, exercendo importante papel em um programa de gerenciamento de recursos hídricos. Abstract in english The water resources management has been an important factor for the sustainability of industrial processes, since there is a growing need for the development of methodologies aimed at the conservation and rational use of water. The objective of this work was to apply the heuristic-algorithmic method [...] called Water Sources Diagram (WSD), which is used to define the target of minimum water consumption, to batch processes. Scenarios with reuse of streams were generated and evaluated with application of the method from the data of water quantity and concentration of contaminants in the operations. Two case studies aiming to show the reduction of water consumption and wastewater generation, and final treatment costs besides investment in storage tanks, were presented. The scenarios showed great promising, achieving reduction up to 45% in water consumption and wastewater generation, and a reduction of around 37% on cost of storage tanks, without the need to allocate regeneration processes. Thus, the WSD method showed to be a relevant and flexible alternative regarding to systemic tools aimed at minimizing the consumption of water in industrial processes, playing an important role within a program of water resources management.

Reinaldo Coelho, Mirre; Shaula Christine Leal, Ferreira; Aline Rodrigues, Dias; Fernando Luiz Pellegrini, Pessoa.

322

Transformation of BPMN Diagrams to YAWL Nets  

Directory of Open Access Journals (Sweden)

Full Text Available Business Process Modeling Notation (BPMN is the de facto standard for modeling business processes on a conceptual level. However, BPMN lacks a formal semantics and many of its features need to be further interpret, Consequently that hinders  BPMN as a standard to statically check the semantic correctness of models. YAWL (Yet Another Workflow Language allows the specification of executable workflow models. A transformation between these two languages enables the integration of different levels of abstraction in process modeling. This paper discusses how to transform BPMN diagrams to YAWL nets. The benefits of the transformation are threefold. Firstly, it clarifies the semantics of BPMN via a mapping to YAWL. Secondly, the deployment of BPMN business process models is simplified. Thirdly, BPMN models can be analyzed with YAWL verification tools.

Jianhong Ye

2010-04-01

323

INVESTIGATION OF MULTISCALE AND MULTIPHASE FLOW, TRANSPORT AND REACTION IN HEAVY OIL RECOVERY PROCESSES  

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

324

Numerical Study on Steel Flow and Inclusion Behavior during a Ladle Teeming Process  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Inclusions in molten steel have received worldwide concern due to their serious influence on both the steel product quality and the steel production process. These inclusions may come from the deoxidation process, reoxidation by air and/or slag due to an entrainment during steel transfer, and so on. They can break up a casting process by clogging a nozzle. A good knowledge on both steel flow and inclusion behavior is really important to understand nozzle clogging, as well as to take some poss...

Ni, Peiyuan

2013-01-01

325

Gas flow through a multilayer ceramic mould in lost wax foundry process  

Directory of Open Access Journals (Sweden)

Full Text Available The paper deals with the issues of permeability testing of ceramic moulds used in lost wax foundry process. The main issue in thetesting is to provide proper specimens of ceramic moulds (CM. The moulds have to be repeatable and must be free of internal defects ofmicrocrack type that are formed mainly during the removal of patterns from CM in the course of heat treatment.Moreover, the process of forming ceramic moulds must be similar to the general industrial process of CM moulds making regardingtheir anisotropic structure. The permeability parameter reflecting gas flow through multilayer ceramic moulds was also examined withattention to the investment casting shape accuracy.

H. Matysiak

2009-04-01

326

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

327

The Cerebral Blood Flow Correlates of Emotional Facial Processing in Mild Alzheimer's Disease  

Directory of Open Access Journals (Sweden)

Full Text Available Deficits in facial emotion processing are features of mild Alzheimer’s disease (AD. These impairments are often dis-tressing for carers as well as patients. Such non-cognitive symptoms are often cited as a contributing reason for admis-sion into institutionalised care. The ability to interpret emotional cues is crucial to healthy psychological function and relationships and impaired emotional facility may lead to antisocial behavior. Understanding the origins of the non-cognitive aspects of AD may lead to an improvement in the management of sufferers and ease the carer burden. In a cross-sectional study we recorded patients’ facial processing abilities, (emotion and identity recognition and disease severity (ADAS-cog, Neuropsychiatic Inventory and investigated the regional cerebral blood flow correlates of facial emotion processing deficits using 99Tcm HMAPO rCBF SPECT. Using statistical parametric mapping (SPM we iden-tified decreased blood flow in posterior frontal regions specifically associated with emotion perception deficits. Non-emotional facial processing abilities or disease severity. The posterior frontal lobe has been identified in previous stud-ies in the absence of dementia as being important in emotion processing. The results suggest that the cognitive disease severity, in combination with the facial processing ability, do not completely explain facial emotion processing in AD patients and that the posterior frontal lobe mediates such behaviour.

Lawrence J. Whalley

2011-03-01

328

A Temperature-Profile Method for Estimating Flow Processes in Geologic Heat Pipes  

Energy Technology Data Exchange (ETDEWEB)

Above-boiling temperature conditions, as encountered, for example, in geothermal reservoirs and in geologic repositories for the storage of heat-producing nuclear wastes, may give rise to strongly altered liquid and gas flow processes in porous subsurface environments. The magnitude of such flow perturbation is extremely hard to measure in the field. We therefore propose a simple temperature-profile method that uses high-resolution temperature data for deriving such information. The energy that is transmitted with the vapor and water flow creates a nearly isothermal zone maintained at about the boiling temperature, referred to as a heat pipe. Characteristic features of measured temperature profiles, such as the differences in the gradients inside and outside of the heat pipe regions, are used to derive the approximate magnitude of the liquid and gas fluxes in the subsurface, for both steady-state and transient conditions.

J.T. Birkholzer

2005-01-21

329

A Temperature-Profile Method for Estimating Flow Processes inGeologic Heat Pipes  

Energy Technology Data Exchange (ETDEWEB)

Above-boiling temperature conditions, as encountered, forexample, in geothermal reservoirs and in geologic repositories for thestorage of heat-producing nuclear wastes, may give rise to stronglyaltered liquid and gas flow processes in porous subsurface environments.The magnitude of such flow perturbation is extremely hard to measure inthe field. We therefore propose a simple temperature-profile method thatuses high-resolution temperature data for deriving such information. Theenergy that is transmitted with the vapor and water flow creates a nearlyisothermal zone maintained at about the boiling temperature, referred toas a heat pipe. Characteristic features of measured temperature profiles,such as the differences in the gradients inside and outside of the heatpipe regions, are used to derive the approximate magnitude of the liquidand gas fluxes in the subsurface, for both steady-state and transientconditions.

Birkholzer, Jens T.

2004-12-06

330

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

Science.gov (United States)

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

331

Stages of the 'actual' loading diagram  

International Nuclear Information System (INIS)

Characteristics of the loading diagrams for polycrystalline ?-Fe, alloys BT-1 and BT-6 with submicrocrystalline (SMC) structure, as well as polycrystalline Al+5% Mg and Al+10% Al2O3 with a pronounced effect of intermittent flow, were obtained, taking into account the deformation of the sample in zone of the neck formation before the fraction. The method for measuring the degree of plastic deformation in the local zone of minimum cross-section was offered. It is shown that for determination the stages of strain hardening material during loading is fundamentally important the consideration of plastic strain localization in the local volume of the sample at the stage forming the neck before the fracture of the material.

332

Coupled turbulent flow, heat transport in twin-roll casting stainless strip process  

International Nuclear Information System (INIS)

A fully coupled fluid flow, heat transport model was developed to analyze turbulent flow, solidification in twin-roll casting stainless strip process. Transport equations of the total mass, momentum, energy for the system were solved using a continuum model, wherein the equations are valid for the solid, liquid, and mushy zones in the casting process. A new version of the low-Reynolds number k-· model was adopted to incorporate turbulent effects on transport processes in the system. A control-volume-based finite element method was employed to solve the conservation equations associated with appropriate boundary conditions. Because of the high nonlinearity of the equations, a number of techniques were used to accelerate the convergence processes. The effects of the factors such as roll-casting speed, steel grade, nozzle configuration on the flow pattern, solidification profile, heat flux changing between the sump and the roll and the temperature of the strip face were calculated. Some of the calculated results were compared with available experimental measurements, and they are in reasonable agreements. The effect of the factors such as casting temperature, casting speed on as-cast structures of the stainless strips were also analyzed by some metallographic photos. Some important parameters were obtained. (author)

333

Coupled turbulent flow, heat transport in twin-roll casting stainless strip process  

Energy Technology Data Exchange (ETDEWEB)

A fully coupled fluid flow, heat transport model was developed to analyze turbulent flow, solidification in twin-roll casting stainless strip process. Transport equations of the total mass, momentum, energy for the system were solved using a continuum model, wherein the equations are valid for the solid, liquid, and mushy zones in the casting process. A new version of the low-Reynolds number k-{center_dot} model was adopted to incorporate turbulent effects on transport processes in the system. A control-volume-based finite element method was employed to solve the conservation equations associated with appropriate boundary conditions. Because of the high nonlinearity of the equations, a number of techniques were used to accelerate the convergence processes. The effects of the factors such as roll-casting speed, steel grade, nozzle configuration on the flow pattern, solidification profile, heat flux changing between the sump and the roll and the temperature of the strip face were calculated. Some of the calculated results were compared with available experimental measurements, and they are in reasonable agreements. The effect of the factors such as casting temperature, casting speed on as-cast structures of the stainless strips were also analyzed by some metallographic photos. Some important parameters were obtained. (author)

Miao, Y.; Hongshuang, D.; Guodong, W.; Xianghua, L. [Northeastern Univ., State Key Lab. of Rolling and Automation, Shenyang City (China)

2000-07-01

334

Modeling erosion and sedimentation coupled with hydrological and overland flow processes at the watershed scale  

Science.gov (United States)

A novel two-dimensional, physically based model of soil erosion and sediment transport coupled to models of hydrological and overland flow processes has been developed. The Hairsine-Rose formulation of erosion and deposition processes is used to account for size-selective sediment transport and differentiate bed material into original and deposited soil layers. The formulation is integrated within the framework of the hydrologic and hydrodynamic model tRIBS-OFM, Triangulated irregular network-based, Real-time Integrated Basin Simulator-Overland Flow Model. The integrated model explicitly couples the hydrodynamic formulation with the advection-dominated transport equations for sediment of multiple particle sizes. To solve the system of equations including both the Saint-Venant and the Hairsine-Rose equations, the finite volume method is employed based on Roe's approximate Riemann solver on an unstructured grid. The formulation yields space-time dynamics of flow, erosion, and sediment transport at fine scale. The integrated model has been successfully verified with analytical solutions and empirical data for two benchmark cases. Sensitivity tests to grid resolution and the number of used particle sizes have been carried out. The model has been validated at the catchment scale for the Lucky Hills watershed located in southeastern Arizona, USA, using 10 events for which catchment-scale streamflow and sediment yield data were available. Since the model is based on physical laws and explicitly uses multiple types of watershed information, satisfactory results were obtained. The spatial output has been analyzed and the driving role of topography in erosion processes has been discussed. It is expected that the integrated formulation of the model has the promise to reduce uncertainties associated with typical parameterizations of flow and erosion processes. A potential for more credible modeling of earth-surface processes is thus anticipated.

Kim, Jongho; Ivanov, Valeriy Y.; Katopodes, Nikolaos D.

2013-09-01

335

Effects of plant root on hydraulic performance of clogging process in subsurface flow constructed wetland  

Science.gov (United States)

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

336

Phase diagrams of two-lane driven diffusive systems  

Science.gov (United States)

We consider a large class of two-lane driven diffusive systems in contact with reservoirs at their boundaries and develop a stability analysis of mean-field profiles as a method to derive the phase diagrams of such systems. We illustrate the method by deriving phase diagrams for the asymmetric exclusion process coupled to various second lanes: a diffusive lane, an asymmetric exclusion process with advection in the same direction as the first lane, and an asymmetric exclusion process with advection in the opposite direction. The competing currents on the two lanes naturally lead to a very rich phenomenology and we find a variety of phase diagrams. It is shown that the stability analysis is equivalent to an 'extremal current principle' for the total current in the two lanes. We also point to classes of models where the analysis fails due to the lack of a dynamically stable current-density relation.

Evans, M. R.; Kafri, Y.; Sugden, K. E. P.; Tailleur, J.

2011-06-01

337

Turbulent impinging flow simulation for high-level waste storage and processing applications  

International Nuclear Information System (INIS)

The efficient storage and processing of high-level nuclear waste could be improved by a better understanding of the behaviour of the particle-laden fluid flows involved. This work reports a mathematical modeling study of impinging single and two-phase turbulent jets that is of relevance to the flows used industrially to prevent the settling of solid particles in storage tanks, and to re-suspend particles that form a bed. A computational fluid dynamic model, that embodies a Lagrangian particle tracking technique, is applied to the prediction of these flows. Predictions in the free flow and wall regions, and along the stagnation line, of the single phase flow are in reasonable accord with data, although the addition of particles results in less satisfactory agreement between predictions and measurements. The influence of particles is, however, reproduced qualitatively by the mathematical model, with quantitative differences attributable to a lack of particle drag in the simulations. Uncertainties in experimental parameters may be responsible for some of the differences between predictions and data, and examination of the data used casts doubts on its reliability. Further work is required in terms of the use of more advanced turbulence modeling techniques, and the provision of detailed and reliable data sets. (authors)

338

Economic compensation standard for irrigation processes to safeguard environmental flows in the Yellow River Estuary, China  

Science.gov (United States)

SummaryAgriculture and ecosystems are increasingly competing for water. We propose an approach to assess the economic compensation standard required to release water from agricultural use to ecosystems while taking into account seasonal variability in river flow. First, we defined agricultural water shortage as the difference in water volume between agricultural demands and actual supply after maintaining environmental flows for ecosystems. Second, we developed a production loss model to establish the relationship between production losses and agricultural water shortages in view of seasonal variation in river discharge. Finally, we estimated the appropriate economic compensation for different irrigation stakeholders based on crop prices and production losses. A case study in the Yellow River Estuary, China, demonstrated that relatively stable economic compensation for irrigation processes can be defined based on the developed model, taking into account seasonal variations in river discharge and different levels of environmental flow. Annual economic compensation is not directly related to annual water shortage because of the temporal variability in river flow rate and environmental flow. Crops that have stable planting areas to guarantee food security should be selected as indicator crops in economic compensation assessments in the important grain production zone. Economic compensation may be implemented by creating funds to update water-saving measures in agricultural facilities.

Pang, Aiping; Sun, Tao; Yang, Zhifeng

2013-03-01

339

Effect of Inlet and Outlet Flow Conditions on Natural Gas Parameters in Supersonic Separation Process  

Science.gov (United States)

A supersonic separator has been introduced to remove water vapour from natural gas. The mechanisms of the upstream and downstream influences are not well understood for various flow conditions from the wellhead and the back pipelines. We used a computational model to investigate the effect of the inlet and outlet flow conditions on the supersonic separation process. We found that the shock wave was sensitive to the inlet or back pressure compared to the inlet temperature. The shock position shifted forward with a higher inlet or back pressure. It indicated that an increasing inlet pressure declined the pressure recovery capacity. Furthermore, the shock wave moved out of the diffuser when the ratio of the back pressure to the inlet one was greater than 0.75, in which the state of the low pressure and temperature was destroyed, resulting in the re-evaporation of the condensed liquids. Natural gas would be the subsonic flows in the whole supersonic separator, if the mass flow rate was less than the design value, and it could not reach the low pressure and temperature for the condensation and separation of the water vapor. These results suggested a guidance mechanism for natural gas supersonic separation in various flow conditions. PMID:25338207

Yang, Yan; Wen, Chuang; Wang, Shuli; Feng, Yuqing

2014-01-01

340

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english 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; Luiz Alberto Oliveira, Rocha; Sandro Campos, Amico; José Viriato Coelho, Vargas.

2011-09-01

 
 
 
 
341

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

342

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english 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; Luiz Alberto Oliveira, Rocha; Sandro Campos, Amico; José Viriato Coelho, Vargas.

343

Research on fracture analysis, groundwater flow and sorption processes in fractured rocks  

Energy Technology Data Exchange (ETDEWEB)

Due to increasing demand for numerous industrial facilities including nuclear power plants and waste repositories, the feasibility of rocks masses as sites for the facilities has been a geological issue of concern. Rock masses, in general, comprises systems of fractures which can provide pathways for groundwater flow and may also affect the stability of engineered structures. For the study of groundwater flow and sorption processes in fractured rocks, five boreholes were drilled. A stepwise and careful integration of various data obtained from field works and laboratory experiments were carried out to analyze groundwater flow in fractured rocks as follows; (1) investigation of geological feature of the site, (2) identification and characterization of fracture systems using core and televiewer logs, (3) determination of hydrogeological properties of fractured aquifers using geophysical borehole logging, pumping and slug tests, and continuous monitoring of groundwater level and quality, (4) evaluation of groundwater flow patterns using fluid flow modeling. The results obtained from these processes allow a qualitative interpretation of fractured aquifers in the study area. Column experiments of some reactive radionuclides were also performed to examine sorption processes of the radionuclides including retardation coefficients. In addition, analyses of fracture systems covered (1) reconstruction of the Cenozoic tectonic movements and estimation of frequency indices for the Holocene tectonic movements, (2) determination of distributions and block movements of the Quaternary marine terraces, (3) investigation of lithologic and geotechnical nature of study area, and (4) examination of the Cenozoic volcanic activities and determination of age of the dike swarms. Using data obtained from above mentioned analyses along with data related to earthquakes and active faults, probabilistic approach was performed to determine various potential hazards which may result from the Quaternary or the Holocene tectonic movements. (author). 223 refs., 55 tabs., 144 figs.

Lee, Dae-Ha; Kim, Won-Young; Lee, Seung-Gu [Korea Institute of Geology Mining and Materials, Taejon (KR)] (and others)

1999-12-01

344

Simulating the impact of glaciations on continental groundwater flow systems: 1. Relevant processes and model formulation  

Science.gov (United States)

In the recent literature, it has been shown that Pleistocene glaciations had a large impact on North American regional groundwater flow systems. Because of the myriad of complex processes and large spatial scales involved during periods of glaciation, numerical models have become powerful tools to examine how ice sheets control subsurface flow systems. In this paper, the key processes that must be represented in a continental-scale 3-D numerical model of groundwater flow during a glaciation are reviewed, including subglacial infiltration, density-dependent (i.e., high-salinity) groundwater flow, permafrost evolution, isostasy, sea level changes, and ice sheet loading. One-dimensional hydromechanical coupling associated with ice loading and brine generation were included in the numerical model HydroGeoSphere and tested against newly developed exact analytical solutions to verify their implementation. Other processes such as subglacial infiltration, permafrost evolution, and isostasy were explicitly added to HydroGeoSphere. A specified flux constrained by the ice sheet thickness was found to be the most appropriate boundary condition in the subglacial environment. For the permafrost, frozen and unfrozen elements can be selected at every time step with specified hydraulic conductivities. For the isostatic adjustment, the elevations of all the grid nodes in each vertical grid column below the ice sheet are adjusted uniformly to account for the Earth's crust depression and rebound. In a companion paper, the model is applied to the Wisconsinian glaciation over the Canadian landscape in order to illustrate the concepts developed in this paper and to better understand the impact of glaciation on 3-D continental groundwater flow systems.

Lemieux, J.-M.; Sudicky, E. A.; Peltier, W. R.; Tarasov, L.

2008-09-01

345

Research on fracture analysis, groundwater flow and sorption processes in fractured rocks  

Energy Technology Data Exchange (ETDEWEB)

Due to increasing demand for numerous industrial facilities including nuclear power plants and waste repositories, the feasibility of rocks masses as sites for the facilities has been a geological issue of concern. Rock masses, in general, comprises systems of fractures which can provide pathways for groundwater flow and may also affect the stability of engineered structures. such properties of fractures stimulate a synthetic study on (1) analyses of fracture systems, and (2) characterization of groundwater flow and sorption processes in fractured rocks to establish a preliminary model for assessing suitable sites for industrial facilities. The analyses of fracture systems cover (1) reconstruction of the Cenozoic tectonic movements and estimation of frequency indices for the Holocene tectonic movements, (2) determination of distributions and block movements of the Quaternary marine terraces, (3) investigation of lithologic and geotechnical nature of study area, and (4) examination of the Cenozoic volcanic activities and determination of age of the dike swarms. Using data obtained from above mentioned analyses along with data related to earthquakes and active faults, probabilistic approach is performed to determine various potential hazards which may result from the Quaternary or the Holocene tectonic movements. In addition, stepwise and careful integration of various data obtained from field works and laboratory experiments are carried out to analyze groundwater flow in fractures rocks as follows; (1) investigation of geological feature of the site, (2) identification and characterization of fracture systems using core and televiewer logs, (3) determination of conductive fractures using electrical conductivity, temperature, and flow logs, (4) identification of hydraulic connections between fractures using televiewer logs with tracer tests within specific zones. The results obtained from these processes allow a qualitative interpretation of groundwater flow patterns in the study area. Column experiments of some reactive radionuclides are also performed to examine sorption processes of the radionuclides including retardation coefficients. (author). 118 refs., 18 tabs., 35 figs.

Lee, Dae Ha [Korea Institute of Geology Mining and Materials, Taejon (Korea)

1998-12-01

346

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

Science.gov (United States)

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. PMID:21371024

Reimann, Thomas; Birk, Steffen; Rehrl, Christoph; Shoemaker, W Barclay

2012-01-01

347

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.

348

Large Eddy Simulation of Transient Flow, Solidification, and Particle Transport Processes in Continuous-Casting Mold  

Science.gov (United States)

The current study developed a coupled computational model to simulate the transient fluid flow, solidification, and particle transport processes in a slab continuous-casting mold. Transient flow of molten steel in the mold is calculated using the large eddy simulation. An enthalpy-porosity approach is used for the analysis of solidification processes. The transport of bubble and non-metallic inclusion inside the liquid pool is calculated using the Lagrangian approach based on the transient flow field. A criterion of particle entrapment in the solidified shell is developed using the user-defined functions of FLUENT software (ANSYS, Inc., Canonsburg, PA). The predicted results of this model are compared with the measurements of the ultrasonic testing of the rolled steel plates and the water model experiments. The transient asymmetrical flow pattern inside the liquid pool exhibits quite satisfactory agreement with the corresponding measurements. The predicted complex instantaneous velocity field is composed of various small recirculation zones and multiple vortices. The transport of particles inside the liquid pool and the entrapment of particles in the solidified shell are not symmetric. The Magnus force can reduce the entrapment ratio of particles in the solidified shell, especially for smaller particles, but the effect is not obvious. The Marangoni force can play an important role in controlling the motion of particles, which increases the entrapment ratio of particles in the solidified shell obviously.

Liu, Zhongqiu; Li, Linmin; Li, Baokuan; Jiang, Maofa

2014-07-01

349

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

Science.gov (United States)

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

350

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

351

The Butterfly Diagram Internal Structure  

International Nuclear Information System (INIS)

A time-latitude diagram, where the spotgroup area is taken into account, is presented for cycles 12 through 23. The results show that the spotted area is concentrated in few, small portions (knots) of the Butterfly Diagram (BD). The BD may be described as a cluster of knots. Knots are distributed in the butterfly wings in a seemingly randomly way. A knot may appear at either lower or higher latitudes than previous ones, in spite of the prevalent tendency to appear at lower and lower latitudes. Accordingly, the spotted area centroid, far from continuously drifting equatorward, drifts poleward or remains stationary in any hemisphere for significant fractions (? 1/3) of the cycle total duration. In a relevant number of semicycles, knots seem to form two roughly parallel, oblique chains, separated by an underspotted band. This picture suggests that two (or more) ''activity streams'' approach the equator at a rate higher than the spot zone as a whole.

352

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

353

Investigation of Multiscale and Multiphase Flow, Transport and Reaction in Heavy Oil Recovery Processes; SEMIANNUAL  

International Nuclear Information System (INIS)

The emphasis of this work was on investigating the mechanisms and factors that control the recovery of heavy oil with the objective to improve recovery efficiencies. For this purpose the interaction of flow transport and reaction at various scales from the pore network to the field scales were studied. Particular mechanisms to be investigated included the onset of gas flow in foamy oil production and in in-situ steam drive, gravity drainage in steam processes, the development of sustained combustion fronts and the propagation of foams in porous media. Analytical, computational and experimental methods were utilized to advance the state of the art in heavy oil recovery. Successful completion of this research was expected to lead to improvements in the Recovery efficiency of various heavy oil processes

354

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

355

Critical point analysis of phase envelope diagram  

International Nuclear Information System (INIS)

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

356

Critical point analysis of phase envelope diagram  

Energy Technology Data Exchange (ETDEWEB)

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; Siagian, Ucok W. R. [Department of Petroleum Engineering, Institut Teknologi Bandung, Jl. Ganesha 10, Bandung 40132 (Indonesia); Kusdiantara, Rudy, E-mail: rkusdiantara@s.itb.ac.id; Puspita, Dila, E-mail: rkusdiantara@s.itb.ac.id; Sidarto, Kuntjoro A., E-mail: rkusdiantara@s.itb.ac.id; Soewono, Edy; Gunawan, Agus Y. [Department of Mathematics, Institut Teknologi Bandung, Jl. Ganesha 10, Bandung 40132 (Indonesia)

2014-03-24

357

Preliminary Master Logic Diagram for ITER operation  

International Nuclear Information System (INIS)

This paper describes the work performed to develop a Master Logic Diagram (MLD) for the operations phase of the International Thermonuclear Experimental Reactor (ITER). The MLD is a probabilistic risk assessment tool used to identify the broad set of potential initiating events that could lead to an offsite radioactive or toxic chemical release from the facility under study. The MLD described here is complementary to the failure modes and effects analyses (FMEAs) that have been performed for ITER's major plant systems in the engineering evaluation of the facility design. While the FMEAs are a bottom-up or component level approach, the MLD is a top-down or facility level approach to identifying the broad spectrum of potential events. Strengths of the MLD are that it analyzes the entire plant, depicts completeness in the accident initiator process, provides an independent method for identification, and can also identify potential system interactions. MLDs have been used successfully as a hazard analysis tool. This paper describes the process used for the ITER MLD to treat the variety of radiological and toxicological source terms present in the ITER design. One subtree of the nineteen page MLD is shown to illustrate the levels of the diagram

358

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

359

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

360

Opportunities in IT Support of Workflow & Information Flow in the Emergency Department Digital Imaging Process  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The goal of this study is to examine workflow and information flow in the emergency department (ED) digital imaging process to identify features of an optimized system. Radiological imaging (x-rays, CT scans, etc) is unique in the ED setting, as the need for fast turn-around time and interactive communication between radiologists and emergency physicians is different than that of most other healthcare settings. The information technology systems which are used by both radiologists and emergen...

Fairbanks, Rj; Guarrera, Tk; Bisantz, Ab; Venturino, M.; Westesson, Pl

2010-01-01

 
 
 
 
361

Octopaminergic modulation of temporal frequency coding in an identified optic flow-processing interneuron  

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

362

Causal diagrams in systems epidemiology  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Methods of diagrammatic modelling have been greatly developed in the past two decades. Outside the context of infectious diseases, systematic use of diagrams in epidemiology has been mainly confined to the analysis of a single link: that between a disease outcome and its proximal determinant(s. Transmitted causes ("causes of causes" tend not to be systematically analysed. The infectious disease epidemiology modelling tradition models the human population in its environment, typically with the exposure-health relationship and the determinants of exposure being considered at individual and group/ecological levels, respectively. Some properties of the resulting systems are quite general, and are seen in unrelated contexts such as biochemical pathways. Confining analysis to a single link misses the opportunity to discover such properties. The structure of a causal diagram is derived from knowledge about how the world works, as well as from statistical evidence. A single diagram can be used to characterise a whole research area, not just a single analysis - although this depends on the degree of consistency of the causal relationships between different populations - and can therefore be used to integrate multiple datasets. Additional advantages of system-wide models include: the use of instrumental variables - now emerging as an important technique in epidemiology in the context of mendelian randomisation, but under-used in the exploitation of "natural experiments"; the explicit use of change models, which have advantages with respect to inferring causation; and in the detection and elucidation of feedback.

Joffe Michael

2012-03-01

363

Operational analysis of sequence diagram specifications  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This thesis is concerned with operational analysis of UML 2.x sequence diagram specifications. By operational analysis we mean analysis based on a characterization of the executions of sequence diagrams, or in other words an operational semantics for sequence diagrams. We define two methods for analysis of sequence diagram specifications ? refinement verification and refinement testing ? and both are implemented in an analysis tool we have named ?Escalator?. Further, we ma...

2007-01-01

364

T-P phase diagram for ice  

International Nuclear Information System (INIS)

In this study we obtain a T-P phase diagram of ice using the mean field theory. We fit our calculated phase line equations to the experimental T-P phase diagram. By choosing appropriately the coefficients in the free-energy expansions, our calculated phase diagram agrees well with the experimentally observed phase diagram of ice. Some thermodynamic functions are calculated using the free energy for the transitions studied here.

365

Multiphysics numerical modeling of the continuous flow microwave-assisted transesterification process.  

Science.gov (United States)

Use of advanced microwave technology for biodiesel production from vegetable oil is a relatively new technology. Microwave dielectric heating increases the process efficiency and reduces reaction time. Microwave heating depends on various factors such as material properties (dielectric and thermo-physical), frequency of operation and system design. Although lab scale results are promising, it is important to study these parameters and optimize the process before scaling up. Numerical modeling approach can be applied for predicting heating and temperature profiles including at larger scale. The process can be studied for optimization without actually performing the experiments, reducing the amount of experimental work required. A basic numerical model of continuous electromagnetic heating of biodiesel precursors was developed. A finite element model was built using COMSOL Multiphysics 4.2 software by coupling the electromagnetic problem with the fluid flow and heat transfer problem. Chemical reaction was not taken into account. Material dielectric properties were obtained experimentally, while the thermal properties were obtained from the literature (all the properties were temperature dependent). The model was tested for the two different power levels 4000 W and 4700 W at a constant flow rate of 840ml/min. The electric field, electromagnetic power density flow and temperature profiles were studied. Resulting temperature profiles were validated by comparing to the temperatures obtained at specific locations from the experiment. The results obtained were in good agreement with the experimental data. PMID:24432470

Muley, Pranjali D; Boldor, Dorin

2012-01-01

366

An experimental study of fluidization behavior using flow visualization and image processing  

International Nuclear Information System (INIS)

A program of experimental study of fluidization of heavy spherical pellets with water using image processing technique has been started in the Nuclear Engineering Department of the Federal University of Rio Grande do Sul. Fluidization for application in nuclear reactors requires very detailed knowledge of its behavior as the reactivity is closely dependent on the porosity of the fluidized bed. A small modular nuclear reactor concept with suspended core is under study. A modified version of the reactor involves the choice of is to make conical the shape of the reactor core to produce a non-fluctuating bed and consequently guarantee the dynamic stability of the reactor. A 5 mm diameter steel ball are fluidized with water in a conical Plexiglass tube. A pump circulate the water in a loop feeding the room temperature water from the tank into the fluidization system and returning it back to the tank. A controllable valve controls the flow velocity. A high velocity digital CCD camera captures the images of the pellets moving in the fluidized tube. At different flow velocities, the individual pellets can be tracked by processing the sequential frames. A DVT digital tape record stores the images and by acquisition through interface board into a microcomputer. A special program process the data later on. Different algorithm of image treatment determines the velocity fields of the pellets. The behavior of the pellets under different flow velocity and porosity are carefully studw velocity and porosity are carefully studied. (author)

367

An experimental study of fluidization behavior using flow visualization and image processing  

International Nuclear Information System (INIS)

A program of experimental study of fluidization of heavy spherical pellets with water using image processing technique has been started in the Nuclear Engineering Department of the Federal University of Rio Grande do Sul. Fluidization for application in nuclear reactors requires very detailed knowledge of its behavior as the reactivity id closely dependent on the porosity of the fluidized bed. A small modular nuclear reactor concept with suspended core is under study. A modified version of the reactor involves the choice of is to make conical the shape of the reactor core to produce a non-fluctuating bed and consequently guarantee the dynamic stability of the reactor. A 5 mm diameter steel ball are fluidized with water in a conical Plexiglass tube. A pump circulate the water in a loop feeding the room temperature water from the tank into the fluidization system and returning it back to the tank. A controllable valve controls the flow velocity. A high velocity digital CCD camera captures the images of the pellets moving in the fluidized tube. At different flow velocities, the individual pellets can be tracked by processing the sequential frames. A DVT digital tape record stores the images and by acquisition through interface board into a microcomputer. A spatial program process the data later on. Different algorithm of image treatment determines the velocity fields of the pellets. The behavior of the pellets under different flow velocity and porosity are carefully studw velocity and porosity are carefully studied. (author)

368

Influence of the gas mixture flow on the processing parameters of hollow cathode discharge iron sintering  

International Nuclear Information System (INIS)

A study was made to verify the influence of the gas mixture flow on the iron sintering process with simultaneous surface enrichment of alloying elements by hollow cathode discharge. In this process, two independent cathodes formed an annular discharge: (1) a pressed cylindrical sample of iron powder, acting as the central cathode, was placed concentrically inside an external (hollow) cathode; (2) the external cathode, machined from a AISI 310 steel bar, acted both to confine the geometry of the plasma and as a source of alloying elements (Cr and Ni). The sintering was carried out at 1423 K, for a period of 7.2 x 103 s, under a gas mixture of 80% Ar + 20% H2 and a pressure of 399 Pa, at flow rates of 2 x 10-6, 5 x 10-6, and 8 x 10-6 m3 s-1, with an inter-cathode radial space of 5.8 mm. The discharge was generated using a pulsed voltage power source with a 200 ?s period. The gas mixture flow plays an important role both in the cleanliness of the sintering atmosphere (reflected in the electric power utilized to maintain the sample's temperature) and in the amount of metallic atoms deposited on the sample's surface (as a result of the sputtering and the oxidation/reduction process on the cathode surfaces)

369

Teaching Tip: Using Activity Diagrams to Model Systems Analysis Techniques: Teaching What We Preach  

Science.gov (United States)

Activity diagrams are used in Systems Analysis and Design classes as a visual tool to model the business processes of "as-is" and "to-be" systems. This paper presents the idea of using these same activity diagrams in the classroom to model the actual processes (practices and techniques) of Systems Analysis and Design. This tip…

Lending, Diane; May, Jeffrey

2013-01-01

370

Investigating preferential flow processes in soils using anisotropy in electrical resistivity  

Science.gov (United States)

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

371

Fully automated digital holographic processing for monitoring the dynamics of a vesicle suspension under shear flow  

Science.gov (United States)

We investigate the dynamics of a vesicle suspension under shear flow between plates using DHM with a spatially reduced coherent source. Holograms are grabbed at a frequency of 24 frames/sec. The distribution of the vesicle suspension is obtained after numerical processing of the digital holograms sequence resulting in a 4D distribution. Obtaining this distribution is not straightforward and requires special processing to automate the analysis. We present an original method that fully automates the analysis and provides distributions that are further analyzed to extract physical properties of the fluid. Details of the numerical implementation, as well as sample experimental results are presented. PMID:24877015

Minetti, Christophe; Podgorski, Thomas; Coupier, Gwennou; Dubois, Frank

2014-01-01

372

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

373

An adaptive optimisation scheme for controlling air flow process with satisfactory transient performance  

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

374

Step bunching process induced by the flow of steps at the sublimated crystal surface  

CERN Document Server

Stepped GaN(0001) surface is studied by the kinetic Monte Carlo method and compared with the model based on Burton-Carbera-Frank equations. Successive stages of surface pattern evolution during high temperature sublimation process are discussed. At low sublimation rates clear, well defined step bunches form. The process happens in the absence or for very low Schwoebel barriers at the ideal surface. Bunches of several steps are well separated, move slowly and are rather stiff. Character of the process changes for more rapid sublimation process where double step formations become dominant and together with meanders and local bunches assemble into the less ordered surface pattern. Solution of the analytic equations written for one dimensional system confirms that step bunching is induced by the particle advection caused by step-flow anisotropy. This anisotropy becomes important when due to the low Schwoebel barrier both sides of step are symmetric. Simulations show that in the opposite limit of very high Schwoeb...

Zaluska-Kotur, M A; Krukowski, S

2012-01-01

375

Probability Elicitation in Influence Diagram Modeling by Using Interval Probability  

Directory of Open Access Journals (Sweden)

Full Text Available In decision modeling with influence diagrams, the most challenging task is probability elicitation from domain experts. It is usually very difficult for experts to directly assign precise probabilities to chance nodes. In this paper, we propose an approach to elicit probability effectively by using the concept of interval probability (IP. During the elicitation process, a group of experts assign intervals to probabilities instead of assigning exact values. Then the intervals are combined and converted into the point valued probabilities. The detailed steps of the elicitation process are given and illustrated by constructing the influence diagram for employee recruitment decision for a China’s IT Company. The proposed approach provides a convenient and comfortable way for experts to assess probabilities. It is useful in influence diagrams modeling as well as in other subjective probability elicitation situations.

Xiaoxuan Hu

2012-10-01

376

E-DPSO Algorithm Design and Demonstration about Dynamic Selection and Merging Process of ac-Service Flow  

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

377

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

378

Reaction processes and permeability changes during CO2-rich brine flow through fractured Portland cement  

Science.gov (United States)

So far, cement alteration was principally studied experimentally using batch reactor (with static or renewed fluid). All exhibit similar carbonation mechanisms. The acidic solution, formed by the dissolution of the CO2 into the pore water or directly surrounding the cement sample, diffuses into the cement and induces dissolution reactions of the cement hydrates in particular portlandite and CSH. The calcium released by the dissolution of these calcium bearing phases combining with carbonate ions of the fluid forms calcium carbonates. The cement pH, initially around 13, falls to values where carbonate ion is the most dominant element (pH ~ 9), then CaCO3 phases can precipitate. These studies mainly associate carbonation process with a reduction of porosity and permeability. Indeed an increase of volume (about 10%) is expected during the formation of calcite from portlandite (equation 2) assuming a stoichiometric reaction. Here we investigated the cement alteration mechanisms in the frame of a controlled continuous renewal of CO2-rich fluid in a fracture. This situation is that expected when seepage is activated by the mechanical failure of the cement material that initially seals two layers of distinctly different pressure: the storage reservoir and the aquifer above the caprock, for instance. We study the effect of flow rates from quasi-static flow to higher flow rates for well-connected fractures. In the quasi-static case we observed an extensive conversion of portlandite (Ca(OH)2) to calcite in the vicinity of the fracture similar to that observed in the published batch experiments. Eventually, the fracture was almost totally healed. The experiments with constant flow revealed a different behaviour triggered by the continuous renewing of the reactants and withdrawal of reaction products. We showed that calcite precipitation is more efficient for low flow rate. With intermediate flow rate, we measured that permeability increases slowly at the beginning of the experiment and then remains constant due to calcite precipitation in replacement of CSH and CH into fracture border. With higher flow rate, we measured a constant permeability which can be explained by the development of a highly hydrated Si-rich zone which maintains the initial fracture aperture during all over the experiment while noticeable mass is released from the sample. These preliminary results emphasize that more complex behaviours than that envisaged from batch experiments may take place in the vicinity of flowing fractures. We demonstrated that if only micro-cracks appear in the cement well, carbonation reaction may heal these micro-cracks and mitigate leakage whereas conductive fractures allowing high flow may represent a risk of perennial leakage because the net carbonation process, including the calcite precipitation and its subsequent re-dissolution, is sufficiently to heal the fracture. However, the precipitation of Si-rich amorphous phases may maintain the initial fracture aperture and limit the leakage rate. Keywords: leakage, cement alteration, flow rate, fracture, permeability changes, reaction processes.

Abdoulghafour, H.; Luquot, L.; Gouze, P.

2012-12-01

379

vFlow: A GUI-Based Tool for Building Batch Applications for Cloud Computing  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this paper we introduce vFlow - A framework for rapid designing of batch processing applications for Cloud Computing environment. vFlow batch processing system extracts tasks from the vPlans diagrams, systematically captures the dynamics in batch application management tasks, and translates them to Cloud environment API, named vDocuments, that can be used to execute batch processing applications. vDocuments do not only enable the complete execution of low-level configurat...

Gobjuka, Hassan; Ahmat, Kamal

2011-01-01

380

Experimental and theoretical study of flowing foam and of the liquid film formed on the wall for the improvement of decontamination processes using foams  

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)

 
 
 
 
381

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

Science.gov (United States)

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

382

Nozzle design and simulation of gas flow for the laser cutting process  

Science.gov (United States)

In the laser cutting process the gas flow is of main importance to remove molten material from the cut kerf. Changes in nozzle geometry, gas supply pressure and nozzle workpiece stand-off distance have a strong influence on the cut quality. The aim of the investigation is the numerical simulation of supersonic gas flow. Supersonic nozzles for laser applications are designed which can be manufactured more easily and cost effective than conventionally used Laval nozzles. For the simulation wall friction is regarded and the flow field is calculated two dimensional and assumed turbulent. Normal jet impingement for the designed nozzles and underexpanded conic-cylindrical nozzles is compared at various nozzle stand-off distances and shows a more constant pressure on the workpiece for the designed nozzles. Furthermore supersonic effects in the cut kerf are investigated and compared with results from Schlieren photographs. The nonlinear pressure distribution inside the kerf indicates both the shock formation and detachment of the gas flow. In the presence of shock waves the existing equations in finite volume form have been modified, as they lead to wrong predictions both in the shock location and strength due to an incorrect inertia term in the momentum equations.

Leidinger, Doris; Penz, Andreas; Schuoecker, Dieter; Deinzer, Guenter; Geiger, Manfred; Haensel, A.; Herbig, N.

1994-09-01

383

Overland flow in sand dunes: feedbacks between aeolian and hydrological processes  

Science.gov (United States)

During the summer of 2005, Hurricane Dennis overwashed the eastern portion of St. George Island, part of the northwest barrier island chain located along the Florida Panhandle. In this paper, LiDAR-based morphological changes of the barrier island are analyzed, along with the short-term post-storm recovery of secondary dunes. Vegetation deterred dune migration, thus favoring dune growth and reducing erosion due to wind. In contrast, the absence of vegetation inhibited dune growth. Low-elevation areas within the dunes were subject to flooding via saturation overland flow following moderate storm surges and rainfall events. Using a high resolution topographic survey and simple hydrology models, we estimate the discharge and velocities from storm surge return flow and saturation overland flow. Results show that return flow velocities are of the same magnitude as the critical velocity necessary to mobilize sand when a hydraulic connection between the watershed and back-barrier bay is present. Storms of moderate strength and rainfall intensity may be sufficient to keep the return channels open within the back-barrier, thus providing natural conduits for water exchange from overwash events during extreme storm surges triggered by hurricanes. We conclude that hydrological and aeolian processes are strictly coupled in dune fields characteristic of many barrier islands along the US coast.

Fagherazzi, S.; Priestas, A. M.

2012-12-01

384

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)

385

Process for preparing 18F-labelled compounds by irradiating an oxygen flow with charged particles  

International Nuclear Information System (INIS)

A novel process for preparing 18F-labelled compounds is provided which is unique in the high yield of 18F, the extensiveness of application and the rapidness of the preparation. It comprises irradiating an O2 flow with beams of 3He or alpha particles to produce 18F, capturing the resulting 18F directly on an adsorbent (which itself may be a fluorinating reagent such as fluoroborates of fluorides of alkalis) or a medium (such as CH3CONH2, (NCH2)2) or a noble metal (Au, Ag, Pt or their alloys), and employing the captured 18F for synthesis. In one example, a flow of O2 (150 ml/min) was irradiated with the beams at 14 to 15 MeV and the 18F produced was quantitatively captured on an adsorbent. Then an O2 flow containign HF (0.1 g/min) was let flow to effect a nearly quantitative isotopic exchange giving anhydrous H18F. (Kaichi, S.)

386

Relationship Between Storm Hydrograph Components and Subsurface Flow Processes in a Hilly Headwater Basin, Toyota, Japan  

Science.gov (United States)

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

387

Transient Heat and Material Flow Modeling of Friction Stir Processing of Magnesium Alloy using Threaded Tool  

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

388

Improving modeling with layered UML diagrams  

DEFF Research Database (Denmark)

Layered diagrams are diagrams whose elements are organized into sets of layers. Layered diagrams are routinely used in many branches of engineering, except Software Engineering. In this paper, we propose to add layered diagrams to UML modeling tools, and elaborate the concept by exploring usage scenarios. We validate the concept by implementation, lab assessments, and field testing. We conclude that layers enhance and complement conventional diagrams and model structuring techniques, are easy to add to existing modeling infrastructure, and are easy to apply by modelers.

Störrle, Harald

2013-01-01

389

Tangential filtration with a small motive force during separation of dust-gas flows  

Energy Technology Data Exchange (ETDEWEB)

An approach to formulation of a process for tangential filtration of dust-gas flows is described. Schematic diagrams of structural solutions developed for the filters are discussed. Results are presented for aerodynamic characteristics of the filter for different positions of an adjustable baffle. Basic operational problems are analyzed. The efficiency of the regeneration process is evaluated.

S.Y. Panov; Y.N. Shapovalov; Y.V. Krasovitskii; D.V. Nikitenko; O.A. Panova [Voronezh State Technical Academy (Russian Federation)

2007-07-01

390

Water movement and isoproturon behaviour in a drained heavy clay soil: 1. Preferential flow processes  

Science.gov (United States)

The processes and mechanisms that control pesticide transport from drained heavy clay catchments are being studied at Wytham Farm (Oxford University) in southern England. In the first field season field-drain water contained high concentrations of pesticide. Soil studies demonstrated that the main mechanism for pesticide translocation was by preferential flow processes, both over the soil surface and through the soil profile via a macropore system that effectively by-passed the soil matrix. This macropore system included worm holes, shrinkage cracks and cracks resulting from ploughing. Rainfall events in early winter rapidly created a layer of saturation in the A horizon perched above a B horizon of very low hydraulic conductivity. Drain flow was initiated when the saturated layer in the A horizon extended into the upper 0.06m of the soil profile; thereafter water moved down slope via horizontal macropores possibly through a band of incorporated straw residues. These horizontal pathways for water movement connected with the fracture system of the mole drains, thus feeding the drains. Overland flow occurred infrequently during the season.

Haria, A. H.; Johnson, A. C.; Bell, J. P.; Batchelor, C. H.

1994-12-01

391

The distribution of length scales generated by mixing processes in time-p eriodic chaotic flows  

Science.gov (United States)

This talk explores in some detail the evolution of the spatial structure and th e statistical properties of partially mixed systems as they evolve on a torus by using a direct numerical simulation of the evolution of continuous material lin es as they are stretched, reoriented, and folded by the flow. In the time scale s of interest to mixing processes, such material lines grow exponentially fast, but much faster than predicted by the Lyapunov exponent. The filament develops into a self-similar structure; frequency distribution of filament densities corr esponding to different times collapses onto an invariant curve by a simple homog eneous scaling. It is shown that this behavior is a direct consequence of a gen eric asymptotic directionality property characteristic of 2D time-periodic flows . Mixture microstructure is also analyzed by computing the evolution of th e distribution of length scales in the flow. Once again, the result is a family of self-similar curves that scale homogeneously by the mean length scale, which collapses in inverse proportion to the rate of growth of the filament. It is s hown that this rate of collapse, which has direct relevance to mixing applicatio ns, can be accurately and straightforwardly predicted from the ergodic average o f the stretching field. Implications for mixing processes in realistic systems are also discussed.

Muzzio, Fernando; Alvarez, Mario; Cerbelli, Stefano

1997-11-01

392

Using digital flow cytometry to assess the degradation of three cyanobacteria species after oxidation processes.  

Science.gov (United States)

Depending on drinking water treatment conditions, oxidation processes may result in the degradation of cyanobacteria cells causing the release of toxic metabolites (microcystin), odorous metabolites (MIB, geosmin), or disinfection byproduct precursors. In this study, a digital flow cytometer (FlowCAM(®)) in combination with chlorophyll-a analysis was used to evaluate the ability of ozone, chlorine, chlorine dioxide, and chloramine to damage or lyse cyanobacteria cells added to Colorado River water. Microcystis aeruginosa (MA), Oscillatoria sp. (OSC) and Lyngbya sp. (LYN) were selected for the study due to their occurrence in surface water supplies, metabolite production, and morphology. Results showed that cell damage was observed without complete lysis or fragmentation of the cell membrane under many of the conditions tested. During ozone and chlorine experiments, the unicellular MA was more susceptible to oxidation than the filamentous OSC and LYN. Rate constants were developed based on the loss of chlorophyll-a and oxidant exposure, which showed the oxidants degraded MA, OSC, and LYN according to the order of ozone > chlorine ~ chlorine dioxide > chloramine. Digital and binary images taken by the digital flow cytometer provided qualitative insight regarding cell damage. When applying this information, drinking water utilities can better understand the risk of cell damage or lysis during oxidation processes. PMID:23726712

Wert, Eric C; Dong, Mei Mei; Rosario-Ortiz, Fernando L

2013-07-01

393

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