WorldWideScience

Sample records for flow visualization system

  1. Flow visualization

    CERN Document Server

    Merzkirch, Wolfgang

    1974-01-01

    Flow Visualization describes the most widely used methods for visualizing flows. Flow visualization evaluates certain properties of a flow field directly accessible to visual perception. Organized into five chapters, this book first presents the methods that create a visible flow pattern that could be investigated by visual inspection, such as simple dye and density-sensitive visualization methods. It then deals with the application of electron beams and streaming birefringence. Optical methods for compressible flows, hydraulic analogy, and high-speed photography are discussed in other cha

  2. System for flow visualization in swimming

    NARCIS (Netherlands)

    van Houwelingen, J.; van de Water, W.; Kunnen, R.P.J.; van Heijst, GJF; Clerx, H.J.H.; Jansen, A.J.

    2016-01-01

    Understanding the power balance of a swimmer, who needs to overcome power losses to drag and to water set in motion, requires detailed insight into the hydrodynamics of the flow around the swimmer. This will be done from a hydrodynamic point of view with techniques familiar from fluid mechanics.

  3. Flow visualization

    International Nuclear Information System (INIS)

    Weinstein, L.M.

    1991-01-01

    Flow visualization techniques are reviewed, with particular attention given to those applicable to liquid helium flows. Three techniques capable of obtaining qualitative and quantitative measurements of complex 3D flow fields are discussed including focusing schlieren, particle image volocimetry, and holocinematography (HCV). It is concluded that the HCV appears to be uniquely capable of obtaining full time-varying, 3D velocity field data, but is limited to the low speeds typical of liquid helium facilities. 8 refs

  4. Introduction to flow visualization system in SPARC test facility

    International Nuclear Information System (INIS)

    Lee, Wooyoung; Song, Simon; Na, Young Su; Hong, Seong Wan

    2016-01-01

    The released hydrogen can be accumulated and mixed by steam and air depending on containment conditions under severe accident, which generates flammable mixture. Hydrogen explosion induced by ignition source cause severe damage to a structure or facility. Hydrogen risk regarding mixing, distribution, and combustion has been identified by several expert groups and studied actively since TMI accident. A large-scale thermal-hydraulic experimental facility is required to simulate the complex severe accident phenomena in the containment building. We have prepared the test facility, called the SPARC (Spray, Aerosol, Recombiner, Combustion), to resolve the international open issues regarding hydrogen risk. Gas mixing and stratification test using helium instead of hydrogen and estimation of a stratification surface erosion of helium owing to the vertical jet flow will be performed in SPARC. The measurement system is need to observe the gas flow in the large scale test facility such as SPARC. The PIV (particle image velocimetry) system have been installed to visualize gas flow. We are preparing the test facility, called the SPARC, for estimation the thermal-hydraulic process of hydrogen in a closed containment building and the PIV system for quantitative assessment of gas flow. In particular, we will perform gas mixing and erosion of stratification surface test using helium which is the replacement of hydrogen. It will be evaluated by measuring 2D velocity field using the PIV system. The PIV system mainly consists of camera, laser and tracer particle. Expected maximum size of FOV is 750 x 750 mm 2 limited by focal length of lens and high power laser corresponding to 425mJ/pulse at 532 wavelength is required due to large FOV

  5. Laser/fluorescent dye flow visualization technique developed for system component thermal hydraulic studies

    International Nuclear Information System (INIS)

    Oras, J.J.; Kasza, K.E.

    1988-01-01

    A novel laser flow visualization technique is presented together with examples of its use in visualizing complex flow patterns and plans for its further development. This technique has been successfully used to study (1) the flow in a horizontal pipe subject to temperature transients, to view the formation and breakup of thermally stratified flow and to determine instantaneous velocity distributions in the same flow at various axial locations; (2) the discharge of a stratified pipe flow into a plenum exhibiting a periodic vortex pattern; and (3) the thermal-buoyancy-induced flow channeling on the shell side of a heat exchanger with glass tubes and shell. This application of the technique to heat exchangers is unique. The flow patterns deep within a large tube bundle can be studied under steady or transient conditions. This laser flow visualization technique constitutes a very powerful tool for studying single or multiphase flows in complex thermal system components

  6. Thermal hydraulic test for reactor safety system; a visualization study on flow boiling and bubble behavior

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Soon Heung; Baek, Won Pil; Ban, In Cheol [Korea Advanced Institute of Science and Technology, Taejeon (Korea)

    2002-03-01

    The project contribute to understand and to clarify the physical mechanism of flow nucleate boiling and CHF phenomena through the visualization experiments. the results are useful in the development of the enhancement device of heat transfer and to enhance nuclear fuel safety 1. Visual experimental facility 2. Application method of visualization Technique 3. Visualization results of flow nucleate boiling regime - Overall Bubble Behavior on the Heated Surface - Bubble Behavior near CHF Condition - Identification of Flow Structure - Three-layer flow structure 4. Quantifying of bubble parameter through a digital image processing - Image Processing Techniques - Classification of objects and measurements of the size - Three dimensional surface plot with using the luminance 5. Development and estimation of a correlation between bubble diameter and flow parameter - The effect of system parameter on bubble diameter - The development of a bubble diameter correlation . 49 refs., 42 figs., 7 tabs. (Author)

  7. Applications of flow visualization to the development of an innovative boom system

    International Nuclear Information System (INIS)

    Wong, K.F.V.; Wolek, A.

    1996-01-01

    A new oil retention boom system design was developed using a flow visualization technique. Hydrogen bubbles were generated on a fine wire cathode and placed in a stream of moving water with a strong light source to visualize the flow. Observations were made of the flow patterns around some basic shapes and booms modelled as cylinders with and without a skirt. The most effective system design had two booms with skirts in parallel with a submerged airfoil designed to cause the oil to separate and recirculate. Oil was allowed to flow above the airfoil into the recirculation region between the two floating booms. The new system is expected to outperform the conventional boom system only when flow velocity is high. Its most successful application would be in situations where flow is perpendicular to the length of the boom. 1 ref., 6 figs

  8. Flow visualization system for wind turbines without blades applied to micro reactors

    International Nuclear Information System (INIS)

    Santos, G.S.B.; Guimarães, L.N.F.; Placco, G.M.

    2017-01-01

    Flow visualization systems is a tool used in science and industry for characterization of projects that operate with drainage. This work presents the design and construction of a flow visualization system for passive turbines used in advanced fast micro reactors. In the system were generated images where it is possible to see the supersonic and transonic flow through the turbine disks. A test bench was assembled to generate images of the interior of the turbine where the flow is supersonic, allowing the study of the behavior of the boundary layer between disks. It is necessary to characterize the boundary layer of this type of turbine because its operation occurs in the transfer of kinetic energy between the fluid and the disks. The images generated, as well as their analyzes are presented as a result of this work

  9. Visualization and measurement of pressurized multiphase flow using neutron radiography of JRR-3M system

    Energy Technology Data Exchange (ETDEWEB)

    Katoh, Yasuo [Yamaguchi Univ. (Japan); Matsubayasi, Masahito

    1998-01-01

    Concerning the transient phenomenon of solid-gas two-phase flow, an attempt was made to visualize and measure a flow phenomenon in which three-dimensional bubbles occurred, grew and collapsed in the vicinity of a gas injection nozzle while solid particles were circulating. Such a phenomenon could not or hardly be visualized and measured by conventional methods. Such two-phase flow was visualized using neutron radiography, its characteristics measured and the usefulness of the visualization by neutron radiography confirmed. For this purpose, three-dimensional fluidized bed vessels, rectangular or cylindrical-shaped, made of steel or aluminum sheet, were prepared. Polyethylene or glass beads were used as solid particles and activated carbon particles as the tracer. In the experiment, nitrogen gas was blown into the vessel from one nozzle and distributors provided at the bottom of the vessel and exhausted from the top via the exhaust valve, by which the pressure in the vessel was controlled. The imaging was done in the following way: A test chamber was provided beside the vessel to receive neutron beams from the JRR-3M system, the intensity of transmitted neutrons was converted to visible light by scintillator and the images were videotaped. The initial objectives of visualizing and measuring bubbles occurring, growing and collapsing and solid particles circulating in the solid-gas two-phase flow have been achieved by means of neutron radiography. (N.H.)

  10. Flow visualization using bubbles

    International Nuclear Information System (INIS)

    Henry, J.P.

    1974-01-01

    Soap bubbles were used for visualizing flows. The tests effected allowed some characteristics of flows around models in blow tunnels to be precised at mean velocities V 0 5 . The velocity of a bubble is measured by chronophotography, the bulk envelope of the trajectories is also registered [fr

  11. Multimodal flow visualization and optimization of pneumatic blood pump for sorbent hemodialysis system.

    Science.gov (United States)

    Shu, Fangjun; Parks, Robert; Maholtz, John; Ash, Steven; Antaki, James F

    2009-04-01

    Renal Solutions Allient Sorbent Hemodialysis System utilizes a two-chambered pneumatic pump (Pulsar Blood Pump, Renal Solutions, Inc., Warrendale, PA, USA) to avoid limitations associated with peristaltic pumping systems. Single-needle access is enabled by counter-pulsing the two pump chambers, thereby obviating compliance chambers or blood reservoirs. Each chamber propels 20 cc per pulse of 3 s (dual access) or 6 s (single access) duration, corresponding to a peak Reynolds number of approximately 8000 (based on inlet velocity and chamber diameter). A multimodal series of flow visualization studies (tracer particle, dye washout, and dye erosion) was conducted on a sequence of pump designs with varying port locations and diaphragms to improve the geometry with respect to risk of thrombogenesis. Experiments were conducted in a simplified flow loop using occluders to simulate flow resistance induced by tubing and dialyzer. Tracer visualization revealed flow patterns and qualitatively indicated turbulence intensity. Dye washout identified dwell volume and areas of flow stagnation for each design. Dye erosion results indicated the effectiveness and homogeneity of surface washing. Compared to a centered inlet which resulted in a fluid jet that produced two counter-rotating vortices, a tangential inlet introduced a single vortex, and kept the flow laminar. It also provided better surface washing on the pump inner surface. However, a tangential outlet did not present as much benefit as expected. On the contrary, it created a sharp defection to the flow when transiting from filling to ejection.

  12. Visualizing request-flow comparison to aid performance diagnosis in distributed systems.

    Science.gov (United States)

    Sambasivan, Raja R; Shafer, Ilari; Mazurek, Michelle L; Ganger, Gregory R

    2013-12-01

    Distributed systems are complex to develop and administer, and performance problem diagnosis is particularly challenging. When performance degrades, the problem might be in any of the system's many components or could be a result of poor interactions among them. Recent research efforts have created tools that automatically localize the problem to a small number of potential culprits, but research is needed to understand what visualization techniques work best for helping distributed systems developers understand and explore their results. This paper compares the relative merits of three well-known visualization approaches (side-by-side, diff, and animation) in the context of presenting the results of one proven automated localization technique called request-flow comparison. Via a 26-person user study, which included real distributed systems developers, we identify the unique benefits that each approach provides for different problem types and usage modes.

  13. Flow Visualization Studies in the Novacor Left Ventricular Assist System CRADA PC91-002, Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Borovetz, H.S.; Shaffer, F.; Schaub, R.; Lund, L.; Woodard, J.

    1999-01-01

    This paper discusses a series of experiments to visualize and measure flow fields in the Novacor left ventricular assist system (LVAS). The experiments utilize a multiple exposure, optical imaging technique called fluorescent image tracking velocimetry (FITV) to hack the motion of small, neutrally-buoyant particles in a flowing fluid.

  14. Centrifuge in space fluid flow visualization experiment

    Science.gov (United States)

    Arnold, William A.; Wilcox, William R.; Regel, Liya L.; Dunbar, Bonnie J.

    1993-01-01

    A prototype flow visualization system is constructed to examine buoyancy driven flows during centrifugation in space. An axial density gradient is formed by imposing a thermal gradient between the two ends of the test cell. Numerical computations for this geometry showed that the Prandtl number plays a limited part in determining the flow.

  15. Flow, affect and visual creativity.

    Science.gov (United States)

    Cseh, Genevieve M; Phillips, Louise H; Pearson, David G

    2015-01-01

    Flow (being in the zone) is purported to have positive consequences in terms of affect and performance; however, there is no empirical evidence about these links in visual creativity. Positive affect often--but inconsistently--facilitates creativity, and both may be linked to experiencing flow. This study aimed to determine relationships between these variables within visual creativity. Participants performed the creative mental synthesis task to simulate the creative process. Affect change (pre- vs. post-task) and flow were measured via questionnaires. The creativity of synthesis drawings was rated objectively and subjectively by judges. Findings empirically demonstrate that flow is related to affect improvement during visual creativity. Affect change was linked to productivity and self-rated creativity, but no other objective or subjective performance measures. Flow was unrelated to all external performance measures but was highly correlated with self-rated creativity; flow may therefore motivate perseverance towards eventual excellence rather than provide direct cognitive enhancement.

  16. Three-dimensional visualization of material flow during friction stir welding by two pairs of X-ray transmission systems

    International Nuclear Information System (INIS)

    Morisada, Y.; Fujii, H.; Kawahito, Y.; Nakata, K.; Tanaka, M.

    2011-01-01

    Material flow during friction stir welding is crucial to obtaining sound joints. However, this phenomenon is still not fully understood despite many investigations and numerous models. In this study, the material flow is three-dimensionally visualized by X-ray radiography using a tiny spherical tungsten tracer. The movement of the tracer during the friction stir welding is observed by two pairs of X-ray transmission real-time imaging systems. The three-dimensional material flow is obtained by following the locus of the tracer.

  17. Visualization of numerically simulated aerodynamic flow fields

    International Nuclear Information System (INIS)

    Hian, Q.L.; Damodaran, M.

    1991-01-01

    The focus of this paper is to describe the development and the application of an interactive integrated software to visualize numerically simulated aerodynamic flow fields so as to enable the practitioner of computational fluid dynamics to diagnose the numerical simulation and to elucidate essential flow physics from the simulation. The input to the software is the numerical database crunched by a supercomputer and typically consists of flow variables and computational grid geometry. This flow visualization system (FVS), written in C language is targetted at the Personal IRIS Workstations. In order to demonstrate the various visualization modules, the paper also describes the application of this software to visualize two- and three-dimensional flow fields past aerodynamic configurations which have been numerically simulated on the NEC-SXIA Supercomputer. 6 refs

  18. Flow lab.: flow visualization and simulation

    International Nuclear Information System (INIS)

    Park, Chung Kyun; Cho, Won Jin; Hahn, Pil Soo

    2005-01-01

    The experimental setups for flow visualization and processes identification in laboratory scale (so called Flow Lab.) has developed to get ideas and answer fundamental questions of flow and migration in geologic media. The setup was made of a granite block of 50x50cm scale and a transparent acrylate plate. The tracers used in this experiments were tritiated water, anions, and sorbing cations as well as an organic dye, eosine, to visualize migration paths. The migration plumes were taken with a digital camera as a function of time and stored as digital images. A migration model was also developed to describe and identify the transport processes. Computer simulation was carried out not only for the hydraulic behavior such as distributions of pressure and flow vectors in the fracture but also for the migration plume and the elution curves

  19. Study of visualized simulation and analysis of nuclear fuel cycle system based on multilevel flow model

    Institute of Scientific and Technical Information of China (English)

    LIU Jing-Quan; YOSHIKAWA Hidekazu; ZHOU Yang-Ping

    2005-01-01

    Complex energy and environment system, especially nuclear fuel cycle system recently raised social concerns about the issues of economic competitiveness, environmental effect and nuclear proliferation. Only under the condition that those conflicting issues are gotten a consensus between stakeholders with different knowledge background, can nuclear power industry be continuingly developed. In this paper, a new analysis platform has been developed to help stakeholders to recognize and analyze various socio-technical issues in the nuclear fuel cycle system based on the functional modeling method named Multilevel Flow Models (MFM) according to the cognition theory of human being. Its character is that MFM models define a set of mass, energy and information flow structures on multiple levels of abstraction to describe the functional structure of a process system and its graphical symbol representation and the means-end and part-whole hierarchical flow structure to make the represented process easy to be understood. Based upon this methodology, a micro-process and a macro-process of nuclear fuel cycle system were selected to be simulated and some analysis processes such as economics analysis, environmental analysis and energy balance analysis related to those flows were also integrated to help stakeholders to understand the process of decision-making with the introduction of some new functions for the improved Multilevel Flow Models Studio, and finally the simple simulation such as spent fuel management process simulation and money flow of nuclear fuel cycle and its levelised cost analysis will be represented as feasible examples.

  20. Techniques of Flow Visualization

    Science.gov (United States)

    1987-12-01

    are sensitive. Within the bandwidth of their sensitivity, up to ten color hues may be discriminated by the eye. The visible edge between two colors...can be performed with conven- tional photography or cinematography . Video recording is of advantage for the further pro- cessing of the flow pictures

  1. Study of visualized simulation and analysis of nuclear fuel cycle system based on multilevel flow model

    International Nuclear Information System (INIS)

    Liu Jingquan; Yoshikawa, H.; Zhou Yangping

    2005-01-01

    Complex energy and environment system, especially nuclear fuel cycle system recently raised social concerns about the issues of economic competitiveness, environmental effect and nuclear proliferation. Only under the condition that those conflicting issues are gotten a consensus between stakeholders with different knowledge background, can nuclear power industry be continuingly developed. In this paper, a new analysis platform has been developed to help stakeholders to recognize and analyze various socio-technical issues in the nuclear fuel cycle sys- tem based on the functional modeling method named Multilevel Flow Models (MFM) according to the cognition theory of human being, Its character is that MFM models define a set of mass, energy and information flow structures on multiple levels of abstraction to describe the functional structure of a process system and its graphical symbol representation and the means-end and part-whole hierarchical flow structure to make the represented process easy to be understood. Based upon this methodology, a micro-process and a macro-process of nuclear fuel cycle system were selected to be simulated and some analysis processes such as economics analysis, environmental analysis and energy balance analysis related to those flows were also integrated to help stakeholders to understand the process of decision-making with the introduction of some new functions for the improved Multilevel Flow Models Studio, and finally the simple simulation such as spent fuel management process simulation and money flow of nuclear fuel cycle and its levelised cost analysis will be represented as feasible examples. (authors)

  2. An investigation of flow and resistance characteristics of heat exchanger with the 2-D LDV system and visualization technique

    International Nuclear Information System (INIS)

    Wang Zongsen; Shen Xiong; Xu Yuanhui; Bi Shuxun

    1987-12-01

    An experimental study of the heat exchanger which would be used in a nuclear reactor for low temperature heat-supplying is presented. A 2-D Laser Doppler Velocimeter was used as a unique technique to measure the mean velocity and turbulence intensity distributions in different sections of the model. The relationship between the resistance coefficient and Reynolds number also obtained in terms of the total pressure rakes covered by the casings and the wall static pressure pick-up holes. The flow visualization has realized by using a piece of light source with an Argon-Ion laser. It is apparent that the polystyrene particles seeded in the flow can trace the mean flow. The results showed that the self-similar phenomenon exists in the tube bundle flow system. There are some secondary vortices in the cross sections between two passages of the model

  3. Flow visualization techniques, new developments and modernization of the existing Schlieren system in the Trisonic Wind Tunnel

    Directory of Open Access Journals (Sweden)

    Marius PANAIT

    2011-06-01

    Full Text Available Schlieren flow visualization methods are an important part of high speed wind tunnel testing, being a fast and reliable method of graphically presenting complex dynamic phenomena that occur in high subsonic, transonic and supersonic regimes. Images can be processed and effects of configuration changes can be understood faster. Quantitative variations of the Schlieren method enable CFD simulations to use real data, resulting in greater precision and thus help improve efficiency of the re-design phase for the aerodynamic object. A modification of the classic Schlieren system is proposed, that would enable extraction of such data with minimal costs

  4. Drag Reduction CFD Simulations and Flow Visualization of Light Vehicle-Trailer Systems

    Science.gov (United States)

    Sigurdson, Lorenz; Boyer, Henry; Lange, Carlos F.

    2016-11-01

    Experiments and CFD were performed to study the effect a deflector had on the flow and drag force associated with a 2010 F-150 truck and cargo trailer Light Vehicle-Trailer System (LVTS). Image Correlation Velocimetry (ICV) on smokewire streaklines measured the velocity field on the model mid-plane. CFD estimated the drag reduction as 13% at a Re of 14,900 with a moving ground-plane, and 17% without. Experiments suggested that the low Re does not diminish the full-scale relevance of the drag reduction results. One low Re effect was the presence of a separation bubble on the hood of the tow vehicle whose size reduced with an increase in Re. Three other characteristic flow patterns were identified: separation off the lead vehicle cab, stagnation of the free-stream on the trailer face for the no-deflector case, and subsequent separation at the trailer front corner. Comparisons of the ICV and CFD results with no deflector indicated good agreement in the direction of the velocity vectors, and the smoke streaklines and CFD streamlines also agreed well. However, for the deflector case, the CFD found an entirely different topological solution absent in the experiment. A pair of vertically-oriented mid-plane vortices were wrapped around the front of the trailer. Support from the Canadian Natural Sciences and Engineering Research Council Grant 41747 is gratefully acknowledged.

  5. Visualization of Two Phase Natural Convection Flow in a Vertical Pipe using the Sulfuric Acid - Copper Sulfate Electroplating System

    Energy Technology Data Exchange (ETDEWEB)

    Ohk, Seung-Min; Chae, Myeong-Seon; Chung, Bum-Jin [Kyung Hee Univ., Yongin (Korea, Republic of)

    2014-10-15

    The passive containment cooling system (PCCS) driven by natural forces convection gain draws research interests after Fukushima NPP accident. The PCCS was classified into three categories: Containment pressure suppression, Containment passive heat removal/pressure suppression systems and Passive containment spray. Among the types of containment passive heat removal/pressure suppression systems, the system composed of an internal heat exchanger and an external coolant tank is considered. In a severe accident condition, the heat from the containment atmosphere is transferred to the outer surface of the heat exchanger by the convection and condensation of the mixture of steam and gases. On the other hand, the heat is transferred to external pool by single phase or two phase natural convection inside of heat exchanger pipes. The study aimed at investigating the influence of the diameter (D) and height (H) of the heat exchanger pipes on the single phase and two phase natural convection heat transfer. As the initial stage of the study, the two phase natural convection flow inside a vertical pipe is visualized. In order to achieve the aim with ample test rig, a sulfuric acid - cooper sulfate electroplating system was employed based on the analogy between heat and mass transfer. The reduction of hydrogen ion at the cathode surface at high potential was used to simulate the boiling phenomena. This study tried to visualize the boiling heat transfer inside a vertical pipe using a cupric acid-copper sulfate (H{sub 2}SO{sub 4}-CuSO{sub 4}) electroplating system. This seems to be successful so far. However further study has to be done to compare the result with real two phase flow situation. The surface tension and surface characteristics are to be tuned to simulate the real situation.

  6. Visualization system of swirl motion

    International Nuclear Information System (INIS)

    Nakayama, K.; Umeda, K.; Ichikawa, T.; Nagano, T.; Sakata, H.

    2004-01-01

    The instrumentation of a system composed of an experimental device and numerical analysis is presented to visualize flow and identify swirling motion. Experiment is performed with transparent material and PIV (Particle Image Velocimetry) instrumentation, by which velocity vector field is obtained. This vector field is then analyzed numerically by 'swirling flow analysis', which estimates its velocity gradient tensor and the corresponding eigenvalue (swirling function). Since an instantaneous flow field in steady/unsteady states is captured by PIV, the flow field is analyzed, and existence of vortices or swirling motions and their locations are identified in spite of their size. In addition, intensity of swirling is evaluated. The analysis enables swirling motion to emerge, even though it is hidden in uniform flow and velocity filed does not indicate any swirling. This visualization system can be applied to investigate condition to control flow or design flow. (authors)

  7. Visualization of the air flow behind the automotive benchmark vent

    OpenAIRE

    Pech, Ondřej; Jedelský, Jan; Caletka, Petr; Jícha, Miroslav

    2015-01-01

    Passenger comfort in cars depends on appropriate function of the cabin HVAC system. A great attention is therefore paid to the effective function of automotive vents and proper formation of the flow behind the ventilation outlet. The article deals with the visualization of air flow from the automotive benchmark vent. The visualization was made for two different shapes of the inlet channel connected to the benchmark vent. The smoke visualization with the laser knife was used. The influence of ...

  8. Visualization of Flow Alternatives, Lower Missouri River

    Science.gov (United States)

    Jacobson, Robert B.; Heuser, Jeanne

    2002-01-01

    Background The U.S. Army Corps of Engineers (COE) 'Missouri River Master Water Control Manual' (Master Manual) review has resulted in consideration of many flow alternatives for managing the water in the river (COE, 2001; 1998a). The purpose of this report is to present flow-management alternative model results in a way that can be easily visualized and understood. This report was updated in October 2001 to focus on the specific flow-management alternatives presented by the COE in the 'Master Manual Revised Draft Environmental Impact Statement' (RDEIS; COE, 2001). The original version (February 2000) is available by clicking here. The COE, U.S. Fish and Wildlife Service (FWS), Missouri River states, and Missouri River basin tribes have been participating in discussions concerning water management of the Missouri River mainstem reservoir system (MRMRS), the Missouri River Bank Stabilization and Navigation Project, and the Kansas River reservoir system since 1986. These discussions include general input to the revision of the Master Manual as well as formal consultation under Section 7 of the Endangered Species Act. In 2000, the FWS issued a Biological Opinion that prescribed changes to reservoir management on the Missouri River that were believed to be necessary to preclude jeopardy to three endangered species, the pallid sturgeon, piping plover, and interior least tern (USFWS, 2000). The combined Missouri River system is large and complex, including many reservoirs, control structures, and free-flowing reaches extending over a broad region. The ability to assess future impacts of altered management scenarios necessarily involves complex, computational models that attempt to integrate physical, chemical, biological, and economic effects. Graphical visualization of the model output is intended to improve understanding of the differences among flow-management alternatives.

  9. Visualization system on ITBL

    International Nuclear Information System (INIS)

    Suzuki, Yoshio

    2004-01-01

    Visualization systems PATRAS/ITBL and AVS/ITBL, which are based on visualization software PATRAS and AVS/Express respectively, have been developed on a global, heterogeneous computing environment, Information Technology Based Laboratory (ITBL). PATRAS/ITBL allows for real-time visualization of the numerical results acquired from coupled multi-physics numerical simulations, executed on different hosts situated in remote locations. AVS/ITBL allow for post processing visualization. The scientific data located in remote sites may be selected and visualized on a web browser installed in a user terminal. The global structure and main functions of these systems are presented. (author)

  10. Visualization study of flow in axial flow inducer.

    Science.gov (United States)

    Lakshminarayana, B.

    1972-01-01

    A visualization study of the flow through a three ft dia model of a four bladed inducer, which is operated in air at a flow coefficient of 0.065, is reported in this paper. The flow near the blade surfaces, inside the rotating passages, downstream and upstream of the inducer is visualized by means of smoke, tufts, ammonia filament, and lampblack techniques. Flow is found to be highly three dimensional, with appreciable radial velocity throughout the entire passage. The secondary flows observed near the hub and annulus walls agree with qualitative predictions obtained from the inviscid secondary flow theory.

  11. Visualizing vector field topology in fluid flows

    Science.gov (United States)

    Helman, James L.; Hesselink, Lambertus

    1991-01-01

    Methods of automating the analysis and display of vector field topology in general and flow topology in particular are discussed. Two-dimensional vector field topology is reviewed as the basis for the examination of topology in three-dimensional separated flows. The use of tangent surfaces and clipping in visualizing vector field topology in fluid flows is addressed.

  12. Visualization study of interaction with 2-D film flow on the vertical plate and lateral air velocity for DVI system

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Han Sol; Lee, Jae Young [Handong Global University, Pohang (Korea, Republic of); Euh, Dong Jin; Kim, Jong Rok [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    The present study investigates liquid film flow generated in a downcomer of direct vessel injection (DVI) system which is employed as an emergency core cooling (ECC) system during a loss of coolant accident in the Korea nuclear power plant APR1400. During the late reflooding, complicated multi-phase flow phenomena including the wavy film flow, film breakup, entrainment, liquid film shift due to interfacial drag and gas jet impingement occur. In order to obtain a proper scaling law of the flow, local information of the flow was investigated experimentally and also numerically. A series of experiments were conducted in the 1/20 modified linear scaled plate type test rig to analyze a liquid film from ECC water injection through the DVI nozzle to the downcomer wall. A confocal chromatic sensor was used to measure the local instantaneous liquid film thickness. In this study, the average flow information of the downcomer was analyzed through the information about the thickness, speed, droplet size and speed of highly precise liquid film flow in the structure that occurs in a 2-dimensional liquid film flow, rather than film flow, onset of entrainment, droplet velocity, and size which have been studied in 1-dimension of the existing annular flow. The multi-dimensional flow characteristic information of downcomer can be utilized as the basic data for nuclear safety analysis in the future.

  13. Visualization of the air flow behind the automotive benchmark vent

    Science.gov (United States)

    Pech, Ondrej; Jedelsky, Jan; Caletka, Petr; Jicha, Miroslav

    2015-05-01

    Passenger comfort in cars depends on appropriate function of the cabin HVAC system. A great attention is therefore paid to the effective function of automotive vents and proper formation of the flow behind the ventilation outlet. The article deals with the visualization of air flow from the automotive benchmark vent. The visualization was made for two different shapes of the inlet channel connected to the benchmark vent. The smoke visualization with the laser knife was used. The influence of the shape of the inlet channel to the airflow direction, its enlargement and position of air flow axis were investigated.

  14. Visualization of the air flow behind the automotive benchmark vent

    Directory of Open Access Journals (Sweden)

    Pech Ondrej

    2015-01-01

    Full Text Available Passenger comfort in cars depends on appropriate function of the cabin HVAC system. A great attention is therefore paid to the effective function of automotive vents and proper formation of the flow behind the ventilation outlet. The article deals with the visualization of air flow from the automotive benchmark vent. The visualization was made for two different shapes of the inlet channel connected to the benchmark vent. The smoke visualization with the laser knife was used. The influence of the shape of the inlet channel to the airflow direction, its enlargement and position of air flow axis were investigated.

  15. Flow visualization via partial differential equations

    NARCIS (Netherlands)

    Preusser, T.; Rumpf, M.; Telea, A.C.; Möller, T.; Hamann, B.; Russell, R.D.

    2009-01-01

    The visualization of stationary and time-dependent flow is an important and chaltenging topic in scientific visualization. lts aim is 10 represent transport phenomena govemed by vector fjelds in an intuitively understandable way. In this paper. we review the use of methods based on partial

  16. Making waves: visualizing fluid flows

    NARCIS (Netherlands)

    Zweers, Wout; Zwart, Valerie; Bokhove, Onno

    2013-01-01

    We explore the visualization of violent wave dynamics and erosion by waves and jets in laser-cut reliefs, laser engravings, and three-dimensional printing. For this purpose we built table-top experiments to cast breaking waves, and also explored the creation of extreme or rogue waves in larger wave

  17. The Visual System

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  20. The Visual System

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  1. The Visual System

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    Full Text Available ... for Kids >> The Visual System Listen All About Vision About the Eye Ask a Scientist Video Series ... Eye Health and Safety First Aid Tips Healthy Vision Tips Protective Eyewear Sports and Your Eyes Fun ...

  2. Visualization and simulation of complex flows in biomedical engineering

    CERN Document Server

    Imai, Yohsuke; Ishikawa, Takuji; Oliveira, Mónica

    2014-01-01

    This book focuses on the most recent advances in the application of visualization and simulation methods to understand the flow behavior of complex fluids used in biomedical engineering and other related fields. It shows the physiological flow behavior in large arteries, microcirculation, respiratory systems and in biomedical microdevices.

  3. Creation of subsonic macro-and microjets facilities and automated measuring system (AMS-2) for the spatial - temporal hot - wire anemometric visualization of jet flow field

    Science.gov (United States)

    Sorokin, A. M.; Grek, G. R.; Gilev, V. M.; Zverkov, I. D.

    2017-10-01

    Macro-and microjets facilities for generation of the round and plane subsonic jets are designed and fabricated. Automated measuring system (AMS - 2) for the spatial - temporal hot - wire anemometric visualization of jet flow field is designed and fabricated. Coordinate device and unit of the measurement, collecting, storage and processing of hot - wire anemometric information were integrated in the AMS. Coordinate device is intended for precision movement of the hot - wire probe in jet flow field according to the computer program. At the same time accuracy of the hot - wire probe movement is 5 microns on all three coordinates (x, y, z). Unit of measurement, collecting, storage and processing of hot - wire anemometric information is intended for the hot - wire anemometric measurement of the jet flow field parameters (registration of the mean - U and fluctuation - u' characteristics of jet flow velocity), their accumulation and preservation in the computer memory, and also carries out their processing according to certain programms.

  4. Flow visualization of a monoleaflet and bileaflet mechanical heart valve in a pneumatic ventricular assist device using a PIV system.

    Science.gov (United States)

    Lee, Hwansung; Tatsumi, Eisuke; Taenaka, Yoshiyuki

    2010-01-01

    Our group is developing a new type of pulsatile pneumatic ventricular assist device (PVAD) that uses the Medtronic Hall tilting disc valve (M-H valve). Although tilting disc valves have good washout effect inside the blood pump, they are no longer in common clinical use and may be difficult to obtain in the future. To investigate the stability of the Sorin Bicarbon valve (S-B valve) in our PVAD, we constructed a model pump made of an acrylic resin with the same configuration as our PVAD and attempted to compare the flow visualization upstream and downstream of the outlet position valve between the M-H valve and the S-B valve using a particle image velocimetry (PIV) method. The outlet S-B valve had faster closure than the M-H valve. The maximum flow velocity was greater than with the M-H valve. The maximum Reynolds shear stress (RSS) of the M-H valve reached 150 N/m(2) and that of the S-B valve reached 300 N/m(2) upstream during the end-systolic and early-diastolic phases. In both valves, the maximum RSS upstream of the valve was higher than downstream of the valve because of the regurgitation flow during valve closure. In addition, the maximum viscous shear stress reached above 2 N/m(2), which occupied only about 1%-1.5% of the maximum RSS.

  5. Subsampling-based compression and flow visualization

    Energy Technology Data Exchange (ETDEWEB)

    Agranovsky, Alexy; Camp, David; Joy, I; Childs, Hank

    2016-01-19

    As computational capabilities increasingly outpace disk speeds on leading supercomputers, scientists will, in turn, be increasingly unable to save their simulation data at its native resolution. One solution to this problem is to compress these data sets as they are generated and visualize the compressed results afterwards. We explore this approach, specifically subsampling velocity data and the resulting errors for particle advection-based flow visualization. We compare three techniques: random selection of subsamples, selection at regular locations corresponding to multi-resolution reduction, and introduce a novel technique for informed selection of subsamples. Furthermore, we explore an adaptive system which exchanges the subsampling budget over parallel tasks, to ensure that subsampling occurs at the highest rate in the areas that need it most. We perform supercomputing runs to measure the effectiveness of the selection and adaptation techniques. Overall, we find that adaptation is very effective, and, among selection techniques, our informed selection provides the most accurate results, followed by the multi-resolution selection, and with the worst accuracy coming from random subsamples.

  6. Traffic Flow Visualization and Control

    National Research Council Canada - National Science Library

    Larson, Robert

    1999-01-01

    .... Air Force Research Laboratory. It is a video-camera-based, wide-area, traffic surveillance and detection system that provides real-time traffic information to traffic management center operators...

  7. Flow visualization in science and mathematics

    Energy Technology Data Exchange (ETDEWEB)

    Max, Nelson; Correa, Carlos; Muelder, Chris; Yan Shi; Chen, Cheng-Kai; Ma, Kwan-Liu, E-mail: max@cs.ucdavis.ed [Department of Computer Science, University of California, Davis 1 Shields Ave., Davis California, 95616 (United States)

    2009-07-01

    We present several methods for visualizing motion, vector fields, and flows, including polygonal surface advection, visibility driven transfer functions, feature extraction and tracking, and motion frequency analysis and enhancement. They are applied to chaotic attractors, turbulent vortices, supernovae, and seismic data.

  8. The Visual System

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    Full Text Available ... First Aid Tips Healthy Vision Tips Protective Eyewear Sports and Your Eyes Fun Stuff Cool Eye Tricks Links to More Information Optical Illusions Printables The Visual System Ever wonder how your eyes work? Watch this video to learn how you’re able ...

  9. Visual management support system

    Science.gov (United States)

    Lee Anderson; Jerry Mosier; Geoffrey Chandler

    1979-01-01

    The Visual Management Support System (VMSS) is an extension of an existing computer program called VIEWIT, which has been extensively used by the U. S. Forest Service. The capabilities of this program lie in the rapid manipulation of large amounts of data, specifically opera-ting as a tool to overlay or merge one set of data with another. VMSS was conceived to...

  10. The Visual System

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  12. The Visual System

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  13. The Visual System

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  14. The Visual System

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  15. Visualization of multiphase flow by neutron radiography

    International Nuclear Information System (INIS)

    Mishima, Kaichiro; Takenaka, Nobuyuki.

    1991-01-01

    Neutron radiography (NRG) is a technique which produces images of the internal structure of a body, making use of the attenuation characteristics of neutrons in the materials being observed. Recently, attempts have been made to expand the application of this technique not only to non-destructive testing but also to a variety of industrial and basic research fields. The attenuation of neutrons is large in a light material like water and small in ordinary metals, which difference may make it possible to visualize a multiphase flow in a metallic container. Particularly, the neutron television, which is one of the applied techniques of NRG, is expected to be a useful tool for observing the behavior of two-phase flow, since it produces images in real time. In this paper the basic idea and the method of NRG are presented along with examples of visualization of multiphase flow by NRG. (author)

  16. Engine flow visualization using a copper vapor laser

    Science.gov (United States)

    Regan, Carolyn A.; Chun, Kue S.; Schock, Harold J., Jr.

    1987-01-01

    A flow visualization system has been developed to determine the air flow within the combustion chamber of a motored, axisymmetric engine. The engine has been equipped with a transparent quartz cylinder, allowing complete optical access to the chamber. A 40-Watt copper vapor laser is used as the light source. Its beam is focused down to a sheet approximately 1 mm thick. The light plane is passed through the combustion chamber, and illuminates oil particles which were entrained in the intake air. The light scattered off of the particles is recorded by a high speed rotating prism movie camera. A movie is then made showing the air flow within the combustion chamber for an entire four-stroke engine cycle. The system is synchronized so that a pulse generated by the camera triggers the laser's thyratron. The camera is run at 5,000 frames per second; the trigger drives one laser pulse per frame. This paper describes the optics used in the flow visualization system, the synchronization circuit, and presents results obtained from the movie. This is believed to be the first published study showing a planar observation of airflow in a four-stroke piston-cylinder assembly. These flow visualization results have been used to interpret flow velocity measurements previously obtained with a laser Doppler velocimetry system.

  17. Basic study on an energy conversion system using boiling two-phase flows of temperature-sensitive magnetic fluid. Theoretical analysis based on thermal nonequilibrium model and flow visualization using ultrasonic echo

    International Nuclear Information System (INIS)

    Ishimoto, Jun; Kamiyama, Shinichi; Okubo, Masaaki.

    1995-01-01

    Effects of magnetic field on the characteristics of boiling two-phase pipe flow of temperature-sensitive magnetic fluid are clarified in detail both theoretically and experimentally. Firstly, governing equations of two-phase magnetic fluid flow based on the thermal nonequilibrium two-fluid model are presented and numerically solved considering evaporation and condensation between gas- and liquid-phases. Next, behaviour of vapor bubbles is visualized with ultrasonic echo in the region of nonuniform magnetic field. This is recorded and processed with an image processor. As a result, the distributions of void fraction in the two-phase flow are obtained. Furthermore, detailed characteristics of the two-phase magnetic fluid flow are investigated using a small test loop of the new energy conversion system. From the numerical and experimental results, it is known that the precise control of the boiling two-phase flow and bubble generation is possible by using the nonuniform magnetic field effectively. These fundamental studies on the characteristics of two-phase magnetic fluid flow will contribute to the development of the new energy conversion system using a gas-liquid boiling two-phase flow of magnetic fluid. (author)

  18. Visual computing scientific visualization and imaging systems

    CERN Document Server

    2014-01-01

    This volume aims to stimulate discussions on research involving the use of data and digital images as an understanding approach for analysis and visualization of phenomena and experiments. The emphasis is put not only on graphically representing data as a way of increasing its visual analysis, but also on the imaging systems which contribute greatly to the comprehension of real cases. Scientific Visualization and Imaging Systems encompass multidisciplinary areas, with applications in many knowledge fields such as Engineering, Medicine, Material Science, Physics, Geology, Geographic Information Systems, among others. This book is a selection of 13 revised and extended research papers presented in the International Conference on Advanced Computational Engineering and Experimenting -ACE-X conferences 2010 (Paris), 2011 (Algarve), 2012 (Istanbul) and 2013 (Madrid). The examples were particularly chosen from materials research, medical applications, general concepts applied in simulations and image analysis and ot...

  19. 3D IBFV : Hardware-Accelerated 3D Flow Visualization

    NARCIS (Netherlands)

    Telea, Alexandru; Wijk, Jarke J. van

    2003-01-01

    We present a hardware-accelerated method for visualizing 3D flow fields. The method is based on insertion, advection, and decay of dye. To this aim, we extend the texture-based IBFV technique for 2D flow visualization in two main directions. First, we decompose the 3D flow visualization problem in a

  20. GVS - GENERAL VISUALIZATION SYSTEM

    Science.gov (United States)

    Keith, S. R.

    1994-01-01

    The primary purpose of GVS (General Visualization System) is to support scientific visualization of data output by the panel method PMARC_12 (inventory number ARC-13362) on the Silicon Graphics Iris computer. GVS allows the user to view PMARC geometries and wakes as wire frames or as light shaded objects. Additionally, geometries can be color shaded according to phenomena such as pressure coefficient or velocity. Screen objects can be interactively translated and/or rotated to permit easy viewing. Keyframe animation is also available for studying unsteady cases. The purpose of scientific visualization is to allow the investigator to gain insight into the phenomena they are examining, therefore GVS emphasizes analysis, not artistic quality. GVS uses existing IRIX 4.0 image processing tools to allow for conversion of SGI RGB files to other formats. GVS is a self-contained program which contains all the necessary interfaces to control interaction with PMARC data. This includes 1) the GVS Tool Box, which supports color histogram analysis, lighting control, rendering control, animation, and positioning, 2) GVS on-line help, which allows the user to access control elements and get information about each control simultaneously, and 3) a limited set of basic GVS data conversion filters, which allows for the display of data requiring simpler data formats. Specialized controls for handling PMARC data include animation and wakes, and visualization of off-body scan volumes. GVS is written in C-language for use on SGI Iris series computers running IRIX. It requires 28Mb of RAM for execution. Two separate hardcopy documents are available for GVS. The basic document price for ARC-13361 includes only the GVS User's Manual, which outlines major features of the program and provides a tutorial on using GVS with PMARC_12 data. Programmers interested in modifying GVS for use with data in formats other than PMARC_12 format may purchase a copy of the draft GVS 3.1 Software Maintenance

  1. Application of Light Reflection Visualization for Measuring Organic-Liquid Saturation for Two-Phase Systems in Two-Dimensional Flow Cells.

    Science.gov (United States)

    DiFilippo, Erica L; Brusseau, Mark L

    2011-11-01

    A simple, noninvasive imaging technique was used to obtain in situ measurements of organic-liquid saturation in a two-phase system under dynamic conditions. Efficacy of the light reflection visualization (LRV) imaging method was tested through comparison of measured and known volumes of organic liquid for experiments conducted with a two-dimensional flow cell. Two sets of experiments were conducted, with source-zone configurations representing two archetypical residual-and-pool architectures. LRV measurements were collected during the injection of organic liquid and during a dissolution phase induced by water flushing. There was a strong correlation between measured and known organic-liquid volumes, with the LRV-measured values generally somewhat lower than the known volumes. Errors were greater for the system wherein organic liquid was present in multiple zones comprised of porous media of different permeabilities, and for conditions of multiphase flow. This method proved effective at determining organic-liquid distribution in a two-phase system using minimal specialized equipment.

  2. The Visual System

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  3. The Visual System

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  4. The Visual System

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  5. Visualizing Mobility of Public Transportation System.

    Science.gov (United States)

    Zeng, Wei; Fu, Chi-Wing; Arisona, Stefan Müller; Erath, Alexander; Qu, Huamin

    2014-12-01

    Public transportation systems (PTSs) play an important role in modern cities, providing shared/massive transportation services that are essential for the general public. However, due to their increasing complexity, designing effective methods to visualize and explore PTS is highly challenging. Most existing techniques employ network visualization methods and focus on showing the network topology across stops while ignoring various mobility-related factors such as riding time, transfer time, waiting time, and round-the-clock patterns. This work aims to visualize and explore passenger mobility in a PTS with a family of analytical tasks based on inputs from transportation researchers. After exploring different design alternatives, we come up with an integrated solution with three visualization modules: isochrone map view for geographical information, isotime flow map view for effective temporal information comparison and manipulation, and OD-pair journey view for detailed visual analysis of mobility factors along routes between specific origin-destination pairs. The isotime flow map linearizes a flow map into a parallel isoline representation, maximizing the visualization of mobility information along the horizontal time axis while presenting clear and smooth pathways from origin to destinations. Moreover, we devise several interactive visual query methods for users to easily explore the dynamics of PTS mobility over space and time. Lastly, we also construct a PTS mobility model from millions of real passenger trajectories, and evaluate our visualization techniques with assorted case studies with the transportation researchers.

  6. Visualization of the CMS python configuration system

    International Nuclear Information System (INIS)

    Erdmann, M; Fischer, R; Klimkovich, T; Mueller, G; Steggemann, J; Hegner, B; Hinzmann, A

    2010-01-01

    The job configuration system of the CMS experiment is based on the Python programming language. Software modules and their order of execution are both represented by Python objects. In order to investigate and verify configuration parameters and dependencies naturally appearing in modular software, CMS employs a graphical tool. This tool visualizes the configuration objects, their dependencies, and the information flow. Furthermore it can be used for documentation purposes. The underlying software concepts as well as the visualization are presented.

  7. Visualization of the CMS python configuration system

    Energy Technology Data Exchange (ETDEWEB)

    Erdmann, M; Fischer, R; Klimkovich, T; Mueller, G; Steggemann, J [RWTH Aachen University, Physikalisches Institut 3A, 52062 Aachen (Germany); Hegner, B [CERN, CH-1211 Geneva 23 (Switzerland); Hinzmann, A, E-mail: andreas.hinzmann@cern.c

    2010-04-01

    The job configuration system of the CMS experiment is based on the Python programming language. Software modules and their order of execution are both represented by Python objects. In order to investigate and verify configuration parameters and dependencies naturally appearing in modular software, CMS employs a graphical tool. This tool visualizes the configuration objects, their dependencies, and the information flow. Furthermore it can be used for documentation purposes. The underlying software concepts as well as the visualization are presented.

  8. Flow visualization system for wind turbines without blades applied to micro reactors; Sistema de visualização de escoamento para turbinas sem lâminas aplicada a microrreatores

    Energy Technology Data Exchange (ETDEWEB)

    Santos, G.S.B., E-mail: siqueira.gsb@gmail.com [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), São José dos Campos, SP (Brazil); Guimarães, L.N.F. [Instituto de Estudos Avançados (IEAv), São José dos Campos, SP (Brazil). Departamento de Ciência e Tecnologia Aeroespacial; Placco, G.M. [Instituto Tecnológico de Aeronáutica (PG/CTE/ITA), São José dos Campos, SP (Brazil). Departamento de Ciência e Tecnologia Aeroespacial

    2017-07-01

    Flow visualization systems is a tool used in science and industry for characterization of projects that operate with drainage. This work presents the design and construction of a flow visualization system for passive turbines used in advanced fast micro reactors. In the system were generated images where it is possible to see the supersonic and transonic flow through the turbine disks. A test bench was assembled to generate images of the interior of the turbine where the flow is supersonic, allowing the study of the behavior of the boundary layer between disks. It is necessary to characterize the boundary layer of this type of turbine because its operation occurs in the transfer of kinetic energy between the fluid and the disks. The images generated, as well as their analyzes are presented as a result of this work.

  9. The Visual System

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  10. The Visual System

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  11. The Visual System

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  12. The Visual System

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  13. Preliminary review of mass transfer and flow visualization studies and techniques relevant to the study of erosion-corrosion of reactor piping systems

    International Nuclear Information System (INIS)

    Kuzay, T.M.; Halle, H.J.; Kasza, K.E.

    1988-06-01

    This report provides some background information on the failed piping at the Surry-2 reactor; a summary of pertinent literature on mass transfer in related geometries; and a description of methodologies for visualization and erosion rate measurements in laboratory model studies that can provide greater insight into the role of flow geometry in erosion-corrosion. 18 refs., 9 figs., 1 tab

  14. Preliminary review of mass transfer and flow visualization studies and techniques relevant to the study of erosion-corrosion of reactor piping systems

    Energy Technology Data Exchange (ETDEWEB)

    Kuzay, T.M.; Halle, H.J.; Kasza, K.E.

    1988-06-01

    This report provides some background information on the failed piping at the Surry-2 reactor; a summary of pertinent literature on mass transfer in related geometries; and a description of methodologies for visualization and erosion rate measurements in laboratory model studies that can provide greater insight into the role of flow geometry in erosion-corrosion. 18 refs., 9 figs., 1 tab.

  15. Fluid flow control system

    International Nuclear Information System (INIS)

    Rion, Jacky.

    1982-01-01

    Fluid flow control system featuring a series of grids placed perpendicular to the fluid flow direction, characterized by the fact that it is formed of a stack of identical and continuous grids, each of which consists of identical meshes forming a flat lattice. The said meshes are offset from one grid to the next. This system applies in particular to flow control of the coolant flowing at the foot of an assembly of a liquid metal cooled nuclear reactor [fr

  16. 3D Flow visualization in virtual reality

    Science.gov (United States)

    Pietraszewski, Noah; Dhillon, Ranbir; Green, Melissa

    2017-11-01

    By viewing fluid dynamic isosurfaces in virtual reality (VR), many of the issues associated with the rendering of three-dimensional objects on a two-dimensional screen can be addressed. In addition, viewing a variety of unsteady 3D data sets in VR opens up novel opportunities for education and community outreach. In this work, the vortex wake of a bio-inspired pitching panel was visualized using a three-dimensional structural model of Q-criterion isosurfaces rendered in virtual reality using the HTC Vive. Utilizing the Unity cross-platform gaming engine, a program was developed to allow the user to control and change this model's position and orientation in three-dimensional space. In addition to controlling the model's position and orientation, the user can ``scroll'' forward and backward in time to analyze the formation and shedding of vortices in the wake. Finally, the user can toggle between different quantities, while keeping the time step constant, to analyze flow parameter relationships at specific times during flow development. The information, data, or work presented herein was funded in part by an award from NYS Department of Economic Development (DED) through the Syracuse Center of Excellence.

  17. The Visual System

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  18. Flow Visualization in Supersonic Turbulent Boundary Layers.

    Science.gov (United States)

    Smith, Michael Wayne

    This thesis is a collection of novel flow visualizations of two different flat-plate, zero pressure gradient, supersonic, turbulent boundary layers (M = 2.8, Re _theta ~ 82,000, and M = 2.5, Re_ theta ~ 25,000, respectively). The physics of supersonic shear flows has recently drawn increasing attention with the renewed interest in flight at super and hypersonic speeds. This work was driven by the belief that the study of organized, Reynolds -stress producing turbulence structures will lead to improved techniques for the modelling and control of high-speed boundary layers. Although flow-visualization is often thought of as a tool for providing qualitative information about complex flow fields, in this thesis an emphasis is placed on deriving quantitative results from image data whenever possible. Three visualization techniques were applied--'selective cut-off' schlieren, droplet seeding, and Rayleigh scattering. Two experiments employed 'selective cut-off' schlieren. In the first, high-speed movies (40,000 fps) were made of strong density gradient fronts leaning downstream at between 30^circ and 60^ circ and travelling at about 0.9U _infty. In the second experiment, the same fronts were detected with hot-wires and imaged in real time, thus allowing the examination of the density gradient fronts and their associated single-point mass -flux signals. Two experiments employed droplet seeding. In both experiments, the boundary layer was seeded by injecting a stream of acetone through a single point in the wall. The acetone is atomized by the high shear at the wall into a 'fog' of tiny (~3.5mu m) droplets. In the first droplet experiment, the fog was illuminated with copper-vapor laser sheets of various orientations. The copper vapor laser pulses 'froze' the fog motion, revealing a variety of organized turbulence structures, some with characteristic downstream inclinations, others with large-scale roll-up on the scale of delta. In the second droplet experiment, high

  19. Flow visualization through metal enclosures with neutron radiography

    International Nuclear Information System (INIS)

    Cimbala, J.M.; Sathianathan, D.; Cosgrove, S.A.

    1989-01-01

    Many practical fluid flow problems involve flow inside metal shrouds (valves, combustors, boilers, turbomachinery, etc.) where visual access is not available. For flows under extreme pressure or heat, glass or transparent plastic can not be used; a flow visualization technique which permits visualization through metal containers is needed in these cases. Since neutrons can penetrate metal casings, neutron radiography has been developed for application to fluid flow visualization. This technique involves imaging of neutron opaque tracer materials, such as solid or fluid particles or streaklines, as they convect in neutron transparent ambient fluids. Surface flow visualization is also possible by using neutron opaque tufts. An extension of the surface tuft technique has also been developed, enabling the visualization of flow a patterns away from solid surfaces. This paper presents a summary of the various flow visualization techniques developed in the authors' laboratory, along with examples which illustrate how these techniques may be applied to practical fluid flow problems. These include flow over a circular cylinder, the recirculation pattern formed by a jet exhausting into a tank, and the flow pattern inside a rotating automotive torque converter

  20. Flow Visualization of Forced and Natural Convection in Internal Cavities

    International Nuclear Information System (INIS)

    Crepeau, John; Mcllroy, Hugh M. Jr.; McEligot, Donald M.; Condie, Keith G.; McCreery, Glenn; Clarsean, Randy; Brodkey, Robert S.; Guezennec, Yann G.

    2002-01-01

    The report describes innovative flow visualization techniques, fluid mechanics measurements and computational models of flows in a spent nuclear fuel canister. The flow visualization methods used a fluid that reacted with a metal plate to show how a local reaction affects the surrounding flow. A matched index of refraction facility was used to take mean flow and turbulence measurements within a generic spent nuclear fuel canister. Computational models were also made of the flow in the canister. It was determined that the flow field in the canister was very complex, and modifications may need to be made to ensure that the spent fuel elements are completely passivated

  1. Flow Visualization of Forced and Natural Convection in Internal Cavities

    Energy Technology Data Exchange (ETDEWEB)

    John Crepeau; Hugh M. Mcllroy,Jr.; Donald M. McEligot; Keith G. Condie; Glenn McCreery; Randy Clarsean; Robert S. Brodkey; Yann G. Guezennec

    2002-01-31

    The report descries innovative flow visualization techniques, fluid mechanics measurements and computational models of flows in a spent nuclear fuel canister. The flow visualization methods used a fluid that reacted with a metal plate to show how a local reaction affects the surrounding flow. A matched index of refraction facility was used to take mean flow and turbulence measurements within a generic spent nuclear fuel canister. Computational models were also made of the flow in the canister. It was determined that the flow field in the canister was very complex, and modifications may need to be made to ensure that the spent fuel elements are completely passivated.

  2. Application of neutron radiography to visualization of multiphase flows

    International Nuclear Information System (INIS)

    Takenaka, N.; Fujii, T.; Nishizaki, K.; Asano, H.; Ono, A.; Sonoda, K.; Akagawa, K.

    1990-01-01

    Visualizations by real-time neutron radiography are demonstrated of various flow patterns of nitrogen gas-water two-phase flow in a stainless-steel tube, water inverted annular flow in a stainless-steel tube, flashing flow in an aluminium nozzle and fluidized bed in aluminium tube and vessels. Photographs every 1/60 s are presented by an image processing method to show the dynamic behaviours of the various flow patterns. It is shown that this visualization method can be applied efficiently to multiphase flow researches and will be applicable to multiphase flows in industrial machines. (author)

  3. 3D IBFV : hardware-accelerated 3D flow visualization

    NARCIS (Netherlands)

    Telea, A.C.; Wijk, van J.J.

    2003-01-01

    We present a hardware-accelerated method for visualizing 3D flow fields. The method is based on insertion, advection, and decay of dye. To this aim, we extend the texture-based IBFV technique presented by van Wijk (2001) for 2D flow visualization in two main directions. First, we decompose the 3D

  4. The Visual System

    Medline Plus

    Full Text Available ... visual function, preservation of sight, and the special health problems and requirements of the blind.” News & Events Events ... maintained by the NEI Office of Science Communications, Public Liaison, and Education. ... of Health and Human Services | The National Institutes of Health | ...

  5. Study on flow rate measurement and visualization of helium-air exchange flow through a small opening

    International Nuclear Information System (INIS)

    Fumizawa, Motoo

    1992-01-01

    This paper deals with an experimental investigation on buoyancy-driven exchange flows through horizontal and inclined openings. The method of the mass increment was developed to measure the flow rate in helium-air system and a displacement fringe technique was adopted in Mach-Zehnder interferometer to visualize the flow. As the result, the followings were obtained: Flow visualization results indicate that the upward and downward plumes of helium and air break through the opening intermittently, and they swing in the lateral direction through the horizontal opening. It is clearly visualized that the exchange flows through the inclined openings take place smoothly and stably in the separated passages. The inclination angle for the maximum Froude number decreases with increasing length-to-diameter ratio in the helium-air system, on the contrary to Mercer's experimental results in the water-brine system indicating that the angle remains almost constant. (author)

  6. The GEANT4 Visualization System

    International Nuclear Information System (INIS)

    Allison, J

    2007-01-01

    The Geant4 Visualization System is a multi-driver graphics system designed to serve the Geant4 Simulation Toolkit. It is aimed at the visualization of Geant4 data, primarily detector descriptions and simulated particle trajectories and hits. It can handle a variety of graphical technologies simultaneously and interchangeably, allowing the user to choose the visual representation most appropriate to requirements. It conforms to the low-level Geant4 abstract graphical user interfaces and introduces new abstract classes from which the various drivers are derived and that can be straightforwardly extended, for example, by the addition of a new driver. It makes use of an extendable class library of models and filters for data representation and selection. The Geant4 Visualization System supports a rich set of interactive commands based on the Geant4 command system. It is included in the Geant4 code distribution and maintained and documented like other components of Geant4

  7. Enhanced flow field visualization using a flexible animation procedure

    International Nuclear Information System (INIS)

    Marconi, F.; Moretti, G.; Englund, D.C.

    1989-01-01

    A flexible and powerful procedure for transposing computer-generated images onto video tape is used in flowfield visualization. The result is animated sequences which can be used very effectively in the study of both steady and unsteady flows. The key to the procedure is the fact that the images (i.e., frames) of the animated sequence are recorded on the video tapes one at a time after they are created. Thus, the need for a mass storage system is eliminated because after a frame is recorded it is discarded. 7 references

  8. Investigation of flow stabilization in a compact reactor vessel of a FBR. Flow visualization in a reactor vessel

    International Nuclear Information System (INIS)

    Sato, Hiroyuki; Igarashi, Minoru; Kimura, Nobuyuki; Kamide, Hideki

    2002-01-01

    In the feasibility studies of Commercialized Fast Breeder Reactor Cycle System, a compact reactor vessel is considered from economical improvement point of a sodium cooled loop type fast reactor. The flow field was visualized by water experiment for a reactor vessel with 'a column type UIS (Upper Internal Structure)', which has a slit for fuel handling mechanism and is useful for a compact fast reactor. In this research, the 1/20 scale test equipment using water was made to understand coolant flow through a slit of a column type UIS' and fundamental behavior of reactor upper plenum flow. In the flow visualization tests, tracer particles were added in the water, and illuminated by the slit-shaped pulse laser. The flow visualization image was taken with a CCD camera. We obtained fluid velocity vectors from the visualization image using the Particle Imaging Velocimetry (PIV). The results are as follows. 1. Most of coolant flow through a slit of 'column type UIS' arrived the dip plate directly. In the opposite side of a slit, most of coolant flowed toward reactor vessel wall before it arrived the dip plate. 2. The PIV was useful to measure the flow field in the reactor vessel. The obtained velocity field was consistent with the flow visualization result. 3. The jet through the UIS slit was dependent on the UIS geometry. There is a possibility to control the jet by the UIS geometry. (author)

  9. End-to-End Flow Control for Visual-Haptic Communication under Bandwidth Change

    Science.gov (United States)

    Yashiro, Daisuke; Tian, Dapeng; Yakoh, Takahiro

    This paper proposes an end-to-end flow controller for visual-haptic communication. A visual-haptic communication system transmits non-real-time packets, which contain large-size visual data, and real-time packets, which contain small-size haptic data. When the transmission rate of visual data exceeds the communication bandwidth, the visual-haptic communication system becomes unstable owing to buffer overflow. To solve this problem, an end-to-end flow controller is proposed. This controller determines the optimal transmission rate of visual data on the basis of the traffic conditions, which are estimated by the packets for haptic communication. Experimental results confirm that in the proposed method, a short packet-sending interval and a short delay are achieved under bandwidth change, and thus, high-precision visual-haptic communication is realized.

  10. Illustrative Line Styles for Flow Visualization

    NARCIS (Netherlands)

    Everts, Maarten H.; Bekker, Hendrik; Roerdink, Jos B. T. M.; Isenberg, Tobias

    2011-01-01

    We present a flexible illustrative line style model for the visualization of streamline data. Our model partitions view-oriented line strips into parallel bands whose basic visual properties can be controlled independently. We thus extend previous line stylization techniques specifically for

  11. Flow Visualization using Illustrative Line Styles

    NARCIS (Netherlands)

    Everts, Maarten H.; Bekker, Hendrik; Roerdink, Jos B. T. M.; Isenberg, Tobias; Bekker, Paulus

    2011-01-01

    We present a flexible illustrative line style model for the visualization of streamline data. Our model partitions view- oriented line strips into parallel bands whose basic visual properties can be controlled independently. We thus extend previous line stylization techniques specifically for

  12. Flow boiling in microgap channels experiment, visualization and analysis

    CERN Document Server

    Alam, Tamanna; Jin, Li-Wen

    2013-01-01

    Flow Boiling in Microgap Channels: Experiment, Visualization and Analysis presents an up-to-date summary of the details of the confined to unconfined flow boiling transition criteria, flow boiling heat transfer and pressure drop characteristics, instability characteristics, two phase flow pattern and flow regime map and the parametric study of microgap dimension. Advantages of flow boiling in microgaps over microchannels are also highlighted. The objective of this Brief is to obtain a better fundamental understanding of the flow boiling processes, compare the performance between microgap and c

  13. Gas Flow Detection System

    Science.gov (United States)

    Moss, Thomas; Ihlefeld, Curtis; Slack, Barry

    2010-01-01

    This system provides a portable means to detect gas flow through a thin-walled tube without breaking into the tubing system. The flow detection system was specifically designed to detect flow through two parallel branches of a manifold with only one inlet and outlet, and is a means for verifying a space shuttle program requirement that saves time and reduces the risk of flight hardware damage compared to the current means of requirement verification. The prototype Purge Vent and Drain Window Cavity Conditioning System (PVD WCCS) Flow Detection System consists of a heater and a temperature-sensing thermistor attached to a piece of Velcro to be attached to each branch of a WCCS manifold for the duration of the requirement verification test. The heaters and thermistors are connected to a shielded cable and then to an electronics enclosure, which contains the power supplies, relays, and circuit board to provide power, signal conditioning, and control. The electronics enclosure is then connected to a commercial data acquisition box to provide analog to digital conversion as well as digital control. This data acquisition box is then connected to a commercial laptop running a custom application created using National Instruments LabVIEW. The operation of the PVD WCCS Flow Detection System consists of first attaching a heater/thermistor assembly to each of the two branches of one manifold while there is no flow through the manifold. Next, the software application running on the laptop is used to turn on the heaters and to monitor the manifold branch temperatures. When the system has reached thermal equilibrium, the software application s graphical user interface (GUI) will indicate that the branch temperatures are stable. The operator can then physically open the flow control valve to initiate the test flow of gaseous nitrogen (GN2) through the manifold. Next, the software user interface will be monitored for stable temperature indications when the system is again at

  14. Flow energy conversion system

    International Nuclear Information System (INIS)

    Sargsyan, R.A.

    2011-01-01

    A cost-effective hydropower system called here Flow Energy Converter was developed, patented, manufactured and tested for water pumping, electricity generation and other purposes especially useful for the rural communities. The system consists of water-driven turbine with plane-surface blades, power transmission means and pump and/or generator. Working sample of the Flow Energy Converter was designed and manufactured at the Institute of Radio Physics and Electronics

  15. High speed digital holographic interferometry for hypersonic flow visualization

    Science.gov (United States)

    Hegde, G. M.; Jagdeesh, G.; Reddy, K. P. J.

    2013-06-01

    Optical imaging techniques have played a major role in understanding the flow dynamics of varieties of fluid flows, particularly in the study of hypersonic flows. Schlieren and shadowgraph techniques have been the flow diagnostic tools for the investigation of compressible flows since more than a century. However these techniques provide only the qualitative information about the flow field. Other optical techniques such as holographic interferometry and laser induced fluorescence (LIF) have been used extensively for extracting quantitative information about the high speed flows. In this paper we present the application of digital holographic interferometry (DHI) technique integrated with short duration hypersonic shock tunnel facility having 1 ms test time, for quantitative flow visualization. Dynamics of the flow fields in hypersonic/supersonic speeds around different test models is visualized with DHI using a high-speed digital camera (0.2 million fps). These visualization results are compared with schlieren visualization and CFD simulation results. Fringe analysis is carried out to estimate the density of the flow field.

  16. Flow visualization studies of bodies with square cross sections

    Science.gov (United States)

    Chapman, G. T.; Clarkson, M. H.

    1983-01-01

    A water-tunnel study was conducted of four bodies. A solution of sodium fluorescein coating the body provided visualization of vortices and feeding sheets and isolated dots of methyl blue dye provided visualization of stream lines. These data, along with published oil-flow photos, were analyzed to develop the topological representation of the flows in cross-flow planes. Presented are the development of the flow along the body at fixed angles of attack and at a fixed body station with changes in angle of attack. Effects of roll angle, body corner radius, and nose bluntness are illustrated.

  17. Visual Analysis of Inclusion Dynamics in Two-Phase Flow.

    Science.gov (United States)

    Karch, Grzegorz Karol; Beck, Fabian; Ertl, Moritz; Meister, Christian; Schulte, Kathrin; Weigand, Bernhard; Ertl, Thomas; Sadlo, Filip

    2018-05-01

    In single-phase flow visualization, research focuses on the analysis of vector field properties. In two-phase flow, in contrast, analysis of the phase components is typically of major interest. So far, visualization research of two-phase flow concentrated on proper interface reconstruction and the analysis thereof. In this paper, we present a novel visualization technique that enables the investigation of complex two-phase flow phenomena with respect to the physics of breakup and coalescence of inclusions. On the one hand, we adapt dimensionless quantities for a localized analysis of phase instability and breakup, and provide detailed inspection of breakup dynamics with emphasis on oscillation and its interplay with rotational motion. On the other hand, we present a parametric tightly linked space-time visualization approach for an effective interactive representation of the overall dynamics. We demonstrate the utility of our approach using several two-phase CFD datasets.

  18. The Visual System

    Medline Plus

    Full Text Available ... the Scientific Director Office of the Clinical Director Laboratories, Sections and Units Division of Epidemiology and Clinical ... System Your Eyes’ Natural Defenses Eye Health and Safety First Aid Tips Healthy Vision Tips Protective Eyewear ...

  19. The Visual System

    Medline Plus

    Full Text Available ... System Your Eyes’ Natural Defenses Eye Health and Safety First Aid Tips Healthy Vision Tips Protective Eyewear ... Social Media Policies and Other Important Links NEI Employee Emergency Information NEI Intranet (Employees Only) *PDF files ...

  20. Visual Inspection of the Flow Distribution Plate Bolts of a Nuclear Steam Generator

    International Nuclear Information System (INIS)

    Jeong, Woo Tae; Kim, Suk Tae; Sohn, Wook; Kang, Duk Won; Kang, Seok Chul

    2007-01-01

    To develop a system for visually inspecting the flow distribution plate (FDP) bolts of a nuclear steam generator, we reviewed several types of similar inspection equipment. The equipment which are currently available are mostly for inspecting lower part of a steam generator such as tube sheets and annulus except ELVS (Eggcrate Visual Inspection System). However, the design concept of ELVS could not be used for developing a device which enables the visual inspection of flow distribution plate bolts. Therefore, based on the current state of the art technology on the similar equipment, we conceptually designed a new inspection system for checking the FDP bolts

  1. PIV Analysis of Ludwig Prandtl's Historic Flow Visualization Films

    OpenAIRE

    Willert, Christian; Kompenhans, Jürgen

    2010-01-01

    Around 1930 Ludwig Prandtl and his colleagues O. Tietjens and W. M\\"uller published two films with visualizations of flows around surface piercing obstacles to illustrate the unsteady process of flow separation. These visualizations were achieved by recording the motion of fine particles sprinkled onto the water surface in water channels. The resulting images meet the relevant criteria of properly seeded recordings for particle image velocimetry (PIV). Processing these image sequences with mo...

  2. Visualization of Flow Field: Application of PLIF Technique

    Directory of Open Access Journals (Sweden)

    Jiang Bo Peng

    2018-01-01

    Full Text Available The objective of this paper is to apply planar laser-induced fluorescence (PLIF technology to flow field visualization. This experiment was carried out in a one-meter wind tunnel to study the wake flow field around a circular cylinder. This experiment studied the method of injecting tracer into the flow field; the frequency of the vortex in the wake field and the vortex speed are quantitatively analyzed. This paper gives the correspondence between the speed of the flow field and the frequency of the laser, which could be used as a rough reference standard for future wind tunnel visualization experiments. The result shows that PLIF diagnostic technology has great potential in visualization of flow field.

  3. Flow visualization of two-phase flows using photochromic dye activation method

    International Nuclear Information System (INIS)

    Kawaji, M.; Ahmad, W.; DeJesus, J.M.; Sutharshan, B.; Lorencez, C.; Ojha, M.

    1993-01-01

    A non-intrusive flow visualization technique based on light activation of photochromic dye material has been used to obtain velocity profiles in gas-liquid flows including annular, slug and stratified flows. The preliminary results revealed several important two-phase flow mechanisms that have not been clearly seen previously. (orig.)

  4. SUBSURFACE VISUAL ALARM SYSTEM ANALYSIS

    International Nuclear Information System (INIS)

    D.W. Markman

    2001-01-01

    The ''Subsurface Fire Hazard Analysis'' (CRWMS M andO 1998, page 61), and the document, ''Title III Evaluation Report for the Surface and Subsurface Communication System'', (CRWMS M andO 1999a, pages 21 and 23), both indicate the installed communication system is adequate to support Exploratory Studies Facility (ESF) activities with the exception of the mine phone system for emergency notification purposes. They recommend the installation of a visual alarm system to supplement the page/party phone system The purpose of this analysis is to identify data communication highway design approaches, and provide justification for the selected or recommended alternatives for the data communication of the subsurface visual alarm system. This analysis is being prepared to document a basis for the design selection of the data communication method. This analysis will briefly describe existing data or voice communication or monitoring systems within the ESF, and look at how these may be revised or adapted to support the needed data highway of the subsurface visual alarm. system. The existing PLC communication system installed in subsurface is providing data communication for alcove No.5 ventilation fans, south portal ventilation fans, bulkhead doors and generator monitoring system. It is given that the data communication of the subsurface visual alarm system will be a digital based system. It is also given that it is most feasible to take advantage of existing systems and equipment and not consider an entirely new data communication system design and installation. The scope and primary objectives of this analysis are to: (1) Briefly review and describe existing available data communication highways or systems within the ESF. (2) Examine technical characteristics of an existing system to disqualify a design alternative is paramount in minimizing the number of and depth of a system review. (3) Apply general engineering design practices or criteria such as relative cost, and degree

  5. Physically-based interactive Schlieren flow visualization

    Energy Technology Data Exchange (ETDEWEB)

    Mccormick, Patrick S [Los Alamos National Laboratory; Brownlee, Carson S [Los Alamos National Laboratory; Pegoraro, Vincent [UNIV OF UTAH; Shankar, Siddharth [UNIV OF UTAH; Hansen, Charles D [UNIV OF UTAH

    2009-01-01

    Understanding fluid flow is a difficult problem and of increasing importance as computational fluid dynamics produces an abundance of simulation data. Experimental flow analysis has employed techniques such as shadowgraph and schlieren imaging for centuries which allow empirical observation of inhomogeneous flows. Shadowgraphs provide an intuitive way of looking at small changes in flow dynamics through caustic effects while schlieren cutoffs introduce an intensity gradation for observing large scale directional changes in the flow. The combination of these shading effects provides an informative global analysis of overall fluid flow. Computational solutions for these methods have proven too complex until recently due to the fundamental physical interaction of light refracting through the flow field. In this paper, we introduce a novel method to simulate the refraction of light to generate synthetic shadowgraphs and schlieren images of time-varying scalar fields derived from computational fluid dynamics (CFD) data. Our method computes physically accurate schlieren and shadowgraph images at interactive rates by utilizing a combination of GPGPU programming, acceleration methods, and data-dependent probabilistic schlieren cutoffs. Results comparing this method to previous schlieren approximations are presented.

  6. Arterial secondary blood flow patterns visualized with vector flow ultrasound

    DEFF Research Database (Denmark)

    Pedersen, Mads Møller; Pihl, Michael Johannes; Hansen, Jens Munk

    2011-01-01

    This study presents the first quantification and visualisation of secondary flow patterns with vector flow ultrasound. The first commercial implementation of the vector flow method Transverse Oscillation was used to obtain in-vivo, 2D vector fields in real-time. The hypothesis of this study...... was that the rotational direction is constant within each artery. Three data sets of 10 seconds were obtained from three main arteries in healthy volunteers. For each data set the rotational flow patterns were identified during the diastole. Each data set contains a 2D vector field over time and with the vector angles...

  7. Image processing system for flow pattern measurements

    International Nuclear Information System (INIS)

    Ushijima, Satoru; Miyanaga, Yoichi; Takeda, Hirofumi

    1989-01-01

    This paper describes the development and application of an image processing system for measurements of flow patterns occuring in natural circulation water flows. In this method, the motions of particles scattered in the flow are visualized by a laser light slit and they are recorded on normal video tapes. These image data are converted to digital data with an image processor and then transfered to a large computer. The center points and pathlines of the particle images are numerically analized, and velocity vectors are obtained with these results. In this image processing system, velocity vectors in a vertical plane are measured simultaneously, so that the two dimensional behaviors of various eddies, with low velocity and complicated flow patterns usually observed in natural circulation flows, can be determined almost quantitatively. The measured flow patterns, which were obtained from natural circulation flow experiments, agreed with photographs of the particle movements, and the validity of this measuring system was confirmed in this study. (author)

  8. Visualization and analysis of flow structures in an open cavity

    Science.gov (United States)

    Liu, Jun; Cai, Jinsheng; Yang, Dangguo; Wu, Junqiang; Wang, Xiansheng

    2018-05-01

    A numerical study is performed on the supersonic flow over an open cavity at Mach number of 1.5. A newly developed visualization method is employed to visualize the complicated flow structures, which provide an insight into major flow physics. Four types of shock/compressive waves which existed in experimental schlieren are observed in numerical visualization results. Furthermore, other flow structures such as multi-scale vortices are also obtained in the numerical results. And a new type of shocklet which is beneath large vortices is found. The shocklet beneath the vortex originates from leading edge, then, is strengthened by successive interactions between feedback compressive waves and its attached vortex. Finally, it collides against the trailing surface and generates a large number of feedback compressive waves and intensive pressure fluctuations. It is suggested that the shocklets beneath vortex play an important role of cavity self-sustained oscillation.

  9. Flow visualization of a low density hypersonic flow field

    International Nuclear Information System (INIS)

    Masson, B.S.; Jumper, E.J.; Walters, E.; Segalman, T.Y.; Founds, N.D.

    1989-01-01

    Characteristics of laser induced iodine fluorescence (LIIF) in low density hypersonic flows are being investigated for use as a diagnostic technique. At low pressures, doppler broadening dominates the iodine absorption profile producing a fluorescence signal that is primarily temperature and velocity dependent. From this dependency, a low pressure flow field has the potential to be mapped for its velocity and temperature fields. The theory for relating iodine emission to the velocity and temperature fields of a hypersonic flow is discussed in this paper. Experimental observations are made of a fluorescencing free expansion and qualitatively related to the theory. 7 refs

  10. LDV measurement, flow visualization and numerical analysis of flow distribution in a close-coupled catalytic converter

    International Nuclear Information System (INIS)

    Kim, Duk Sang; Cho, Yong Seok

    2004-01-01

    Results from an experimental study of flow distribution in a Close-coupled Catalytic Converter (CCC) are presented. The experiments were carried out with a flow measurement system specially designed for this study under steady and transient flow conditions. A pitot tube was a tool for measuring flow distribution at the exit of the first monolith. The flow distribution of the CCC was also measured by LDV system and flow visualization. Results from numerical analysis are also presented. Experimental results showed that the flow uniformity index decreases as flow Reynolds number increases. In steady flow conditions, the flow through each exhaust pipe made some flow concentrations on a specific region of the CCC inlet. The transient test results showed that the flow through each exhaust pipe in the engine firing order, interacted with each other to ensure that the flow distribution was uniform. The results of numerical analysis were qualitatively accepted with experimental results. They supported and helped explain the flow in the entry region of CCC

  11. Doppler optical cardiogram gated 2D color flow imaging at 1000 fps and 4D in vivo visualization of embryonic heart at 45 fps on a swept source OCT system.

    Science.gov (United States)

    Mariampillai, Adrian; Standish, Beau A; Munce, Nigel R; Randall, Cristina; Liu, George; Jiang, James Y; Cable, Alex E; Vitkin, I A; Yang, Victor X D

    2007-02-19

    We report a Doppler optical cardiogram gating technique for increasing the effective frame rate of Doppler optical coherence tomography (DOCT) when imaging periodic motion as found in the cardiovascular system of embryos. This was accomplished with a Thorlabs swept-source DOCT system that simultaneously acquired and displayed structural and Doppler images at 12 frames per second (fps). The gating technique allowed for ultra-high speed visualization of the blood flow pattern in the developing hearts of African clawed frog embryos (Xenopus laevis) at up to 1000 fps. In addition, four-dimensional (three spatial dimensions + temporal) Doppler imaging at 45 fps was demonstrated using this gating technique, producing detailed visualization of the complex cardiac motion and hemodynamics in a beating heart.

  12. Visual Modelling of Data Warehousing Flows with UML Profiles

    Science.gov (United States)

    Pardillo, Jesús; Golfarelli, Matteo; Rizzi, Stefano; Trujillo, Juan

    Data warehousing involves complex processes that transform source data through several stages to deliver suitable information ready to be analysed. Though many techniques for visual modelling of data warehouses from the static point of view have been devised, only few attempts have been made to model the data flows involved in a data warehousing process. Besides, each attempt was mainly aimed at a specific application, such as ETL, OLAP, what-if analysis, data mining. Data flows are typically very complex in this domain; for this reason, we argue, designers would greatly benefit from a technique for uniformly modelling data warehousing flows for all applications. In this paper, we propose an integrated visual modelling technique for data cubes and data flows. This technique is based on UML profiling; its feasibility is evaluated by means of a prototype implementation.

  13. Lymphatic System Flows

    Science.gov (United States)

    Moore, James E., Jr.; Bertram, Christopher D.

    2018-01-01

    The supply of oxygen and nutrients to tissues is performed by the blood system and involves a net leakage of fluid outward at the capillary level. One of the principal functions of the lymphatic system is to gather this fluid and return it to the blood system to maintain overall fluid balance. Fluid in the interstitial spaces is often at subatmospheric pressure, and the return points into the venous system are at pressures of approximately 20 cmH2O. This adverse pressure difference is overcome by the active pumping of collecting lymphatic vessels, which feature closely spaced one-way valves and contractile muscle cells in their walls. Passive vessel squeezing causes further pumping. The dynamics of lymphatic pumping have been investigated experimentally and mathematically, revealing complex behaviors that indicate that the system performance is robust against minor perturbations in pressure and flow. More serious disruptions can lead to incurable swelling of tissues called lymphedema.

  14. Flow Visualization of a Rotating Detonation Engine

    Science.gov (United States)

    2016-10-05

    SUPPLEMENTARY NOTES 14. ABSTRACT The rotating detonation engine ( RDE ) is a propulsion system that obtains thrust using continuously existing...2014 – 12/4/2015 Summary: The rotating detonation engine ( RDE ) is a propulsion system that obtains thrust using continuously existing detonation...structure. Studies have been conducted on rotating detonation engines ( RDE ) that obtain thrust from the continuously propagating detonation waves in the

  15. Visualization periodic flows in a continuously stratified fluid.

    Science.gov (United States)

    Bardakov, R.; Vasiliev, A.

    2012-04-01

    To visualize the flow pattern of viscous continuously stratified fluid both experimental and computational methods were developed. Computational procedures were based on exact solutions of set of the fundamental equations. Solutions of the problems of flows producing by periodically oscillating disk (linear and torsion oscillations) were visualized with a high resolutions to distinguish small-scale the singular components on the background of strong internal waves. Numerical algorithm of visualization allows to represent both the scalar and vector fields, such as velocity, density, pressure, vorticity, stream function. The size of the source, buoyancy and oscillation frequency, kinematic viscosity of the medium effects were traced in 2D an 3D posing problems. Precision schlieren instrument was used to visualize the flow pattern produced by linear and torsion oscillations of strip and disk in a continuously stratified fluid. Uniform stratification was created by the continuous displacement method. The buoyancy period ranged from 7.5 to 14 s. In the experiments disks with diameters from 9 to 30 cm and a thickness of 1 mm to 10 mm were used. Different schlieren methods that are conventional vertical slit - Foucault knife, vertical slit - filament (Maksoutov's method) and horizontal slit - horizontal grating (natural "rainbow" schlieren method) help to produce supplementing flow patterns. Both internal wave beams and fine flow components were visualized in vicinity and far from the source. Intensity of high gradient envelopes increased proportionally the amplitude of the source. In domains of envelopes convergence isolated small scale vortices and extended mushroom like jets were formed. Experiments have shown that in the case of torsion oscillations pattern of currents is more complicated than in case of forced linear oscillations. Comparison with known theoretical model shows that nonlinear interactions between the regular and singular flow components must be taken

  16. Visualization of large waves in churn and annular two-phase flow

    International Nuclear Information System (INIS)

    Dasgupta, Arnab; Chandraker, D.K.; Nayak, A.K.; Vijayan, P.K.; Kshirasagar, S.; Reddy, B.R.; Walker, S.P.

    2015-01-01

    The study of churn and annular two-phase flow regimes is important for boiling systems like nuclear reactors, U-tube steam generators etc. In this paper, visualization studies on air-water churn and annular two-phase flow regimes are reported. Though there are differences between air-water and boiling steam water systems, the major flow-pattern characteristics are similar (if not same).The specific object of study is the large waves which exist in both churn and annular regimes. These waves are responsible for majority of the momentum and mass dispersion across the phases. The differentiating characteristics of these waves in the chum and annular flow regimes are reported. The visualization also leads to a more quantitative representation of the transition from churn to annular flow. A new interpretation of the criterion for onset of entrainment is also evolved from the studies. (author)

  17. STRING 3: An Advanced Groundwater Flow Visualization Tool

    Science.gov (United States)

    Schröder, Simon; Michel, Isabel; Biedert, Tim; Gräfe, Marius; Seidel, Torsten; König, Christoph

    2016-04-01

    The visualization of 3D groundwater flow is a challenging task. Previous versions of our software STRING [1] solely focused on intuitive visualization of complex flow scenarios for non-professional audiences. STRING, developed by Fraunhofer ITWM (Kaiserslautern, Germany) and delta h Ingenieurgesellschaft mbH (Witten, Germany), provides the necessary means for visualization of both 2D and 3D data on planar and curved surfaces. In this contribution we discuss how to extend this approach to a full 3D tool and its challenges in continuation of Michel et al. [2]. This elevates STRING from a post-production to an exploration tool for experts. In STRING moving pathlets provide an intuition of velocity and direction of both steady-state and transient flows. The visualization concept is based on the Lagrangian view of the flow. To capture every detail of the flow an advanced method for intelligent, time-dependent seeding is used building on the Finite Pointset Method (FPM) developed by Fraunhofer ITWM. Lifting our visualization approach from 2D into 3D provides many new challenges. With the implementation of a seeding strategy for 3D one of the major problems has already been solved (see Schröder et al. [3]). As pathlets only provide an overview of the velocity field other means are required for the visualization of additional flow properties. We suggest the use of Direct Volume Rendering and isosurfaces for scalar features. In this regard we were able to develop an efficient approach for combining the rendering through raytracing of the volume and regular OpenGL geometries. This is achieved through the use of Depth Peeling or A-Buffers for the rendering of transparent geometries. Animation of pathlets requires a strict boundary of the simulation domain. Hence, STRING needs to extract the boundary, even from unstructured data, if it is not provided. In 3D we additionally need a good visualization of the boundary itself. For this the silhouette based on the angle of

  18. Relating Standardized Visual Perception Measures to Simulator Visual System Performance

    Science.gov (United States)

    Kaiser, Mary K.; Sweet, Barbara T.

    2013-01-01

    Human vision is quantified through the use of standardized clinical vision measurements. These measurements typically include visual acuity (near and far), contrast sensitivity, color vision, stereopsis (a.k.a. stereo acuity), and visual field periphery. Simulator visual system performance is specified in terms such as brightness, contrast, color depth, color gamut, gamma, resolution, and field-of-view. How do these simulator performance characteristics relate to the perceptual experience of the pilot in the simulator? In this paper, visual acuity and contrast sensitivity will be related to simulator visual system resolution, contrast, and dynamic range; similarly, color vision will be related to color depth/color gamut. Finally, we will consider how some characteristics of human vision not typically included in current clinical assessments could be used to better inform simulator requirements (e.g., relating dynamic characteristics of human vision to update rate and other temporal display characteristics).

  19. Development and application of streakline visualization in hypervelocity flows

    Energy Technology Data Exchange (ETDEWEB)

    Lemieux, P.; Hornung, H.G. [Graduate Aeronautical Laboratories, California Institute of Technology, Pasadena, CA 91125 (United States)

    2002-07-01

    A method for visualizing streaklines in hypervelocity flows has been developed. The method uses the high temperatures produced in hypervelocity flows to ablate small amounts of sodium deposited onto a wire stretched across the flow and to broaden the lines in the sodium spectrum. By using a dye laser, tuned to a wavelength close to one of the sodium D-lines, as the light source in shadowgraph or Schlieren visualization, streaklines seeded with sodium become visible through absorption and/or enhanced refractivity. The technique has been used to investigate the stability of the shear layer produced by the curved bow shock on a cylindrically blunted wedge. The results suggest that the shear layer is unstable, exhibiting structures with a wavelength that is comparable to half the nose radius of the body. (orig.)

  20. Visualization of Two Phase Flow in a Horizontal Flow with Electrical Resistance Tomography based on Extended Kalman Filter

    International Nuclear Information System (INIS)

    Lee, Jeong Seong; Malik, Nauman Muhammad; Khambampati, Anil Kumar; Rashid, Ahmar; Kim, Sin; Kim, Kyung Youn

    2008-01-01

    For the visualization of the phase distribution in two phase flows, the electrical resistance tomography (ERT) technique is introduced. In ERT, the internal resistivity distribution is reconstructed based on the known sets of the injected currents and measured voltages on the surface of the object. The physical relationship between the internal resistivity and the surface voltages is governed by a partial differential equation with appropriate boundary conditions. This paper considers the estimation of the phase distribution with ERT in two phase flow in a horizontal flow using extended Kalman filter. To evaluate the reconstruction performance of the proposed algorithm, the experiments simulated two phase flows in a horizontal flow were carried out. The experiments with two phase flow phantom were done to suggest a practical implication of this research in detecting gas bubble in a feed water pipe of heat transfer systems

  1. Visualization and Hierarchical Analysis of Flow in Discrete Fracture Network Models

    Science.gov (United States)

    Aldrich, G. A.; Gable, C. W.; Painter, S. L.; Makedonska, N.; Hamann, B.; Woodring, J.

    2013-12-01

    Flow and transport in low permeability fractured rock is primary in interconnected fracture networks. Prediction and characterization of flow and transport in fractured rock has important implications in underground repositories for hazardous materials (eg. nuclear and chemical waste), contaminant migration and remediation, groundwater resource management, and hydrocarbon extraction. We have developed methods to explicitly model flow in discrete fracture networks and track flow paths using passive particle tracking algorithms. Visualization and analysis of particle trajectory through the fracture network is important to understanding fracture connectivity, flow patterns, potential contaminant pathways and fast paths through the network. However, occlusion due to the large number of highly tessellated and intersecting fracture polygons preclude the effective use of traditional visualization methods. We would also like quantitative analysis methods to characterize the trajectory of a large number of particle paths. We have solved these problems by defining a hierarchal flow network representing the topology of particle flow through the fracture network. This approach allows us to analyses the flow and the dynamics of the system as a whole. We are able to easily query the flow network, and use paint-and-link style framework to filter the fracture geometry and particle traces based on the flow analytics. This allows us to greatly reduce occlusion while emphasizing salient features such as the principal transport pathways. Examples are shown that demonstrate the methodology and highlight how use of this new method allows quantitative analysis and characterization of flow and transport in a number of representative fracture networks.

  2. Mass conservative fluid flow visualization for CFD velocity fields

    International Nuclear Information System (INIS)

    Li, Zhenquan; Mallinson, Gordon D.

    2001-01-01

    Mass conservation is a key issue for accurate streamline and stream surface visualization of flow fields. This paper complements an existing method (Feng et al., 1997) for CFD velocity fields defined at discrete locations in space that uses dual stream functions to generate streamlines and stream surfaces. Conditions for using the method have been examined and its limitations defined. A complete set of dual stream functions for all possible cases of the linear fields on which the method relies are presented. The results in this paper are important for developing new methods for mass conservative streamline visualization from CFD data and using the existing method

  3. Visualization System for Monitoring Data Management Systems

    Directory of Open Access Journals (Sweden)

    Emanuel Pinho

    2016-11-01

    Full Text Available Usually, a Big Data system has a monitoring system for performance evaluation and error prevention. There are some disadvantages in the way that these tools display the information and its targeted approach to physical components. The main goal is to study visual and interactive mechanisms that allow the representation of monitoring data in grid computing environments, providing the end-user information, which can contribute objectively to the system analysis. This paper is an extension of the paper presented at (Pinho and Carvalho 2016 and has the purpose to present the state of the art, carries out the proposed solution and present the achieved goals.

  4. The study on flow characteristics of butterfly valve using flow visualization

    International Nuclear Information System (INIS)

    Yang, S. M.; Hong, S. D.; Song, D. S.; Park, J. K.; Park, J. I.; Shin, S. K.; Kim, H. J.

    2005-01-01

    Flow visualization of butterfly valve is tested for four types(15 deg., 30 .deg., 45 .deg., and 90 .deg.) of valve opening angle. The inner flow characteristics of valve are studied. The flow variation was measured using a high speed camera which takes 500 frames per second with 1024 x 1024 pixels. These captured images were used for calculation to analyze two dimensional flow velocity of the valve. The smaller opening angle, the more increasing the differential pressure of a butterfly valve. Therefore, we know that the complex flow is occurred by increasing the differential pressure. And it is found that the flowing backward is more increased according to the increase of the opening angle of a butterfly valve. However, its flow pattern is similar to a simple pipe flow when the opening angle is 90 .deg.

  5. Distillation and Visualization of Spatiotemporal Structures in Turbulent Flow Fields

    International Nuclear Information System (INIS)

    Hege, Hans-Christian; Hotz, Ingrid; Kasten, Jens

    2011-01-01

    Although turbulence suggests randomness and disorder, organized motions that cause spatiotemporal 'coherent structures' are of particular interest. Revealing such structures in numerically given turbulent or semi-turbulent flows is of interest both for practically working engineers and theoretically oriented physicists. However, as long as there is no common agreement about the mathematical definition of coherent structures, extracting such structures is a vaguely defined task. Instead of searching for a general definition, the data visualization community takes a pragmatic approach and provides various tool chains implemented in flexible software frameworks that allow the user to extract distinct flow field structures. Thus physicists or engineers can select those flow structures which might advance their insight best. We present different approaches to distill important features from turbulent flows and discuss the necessary steps to be taken on the example of Lagrangian coherent structures.

  6. Flow visualization in models of high speed centrifugal separators

    International Nuclear Information System (INIS)

    Lagerstedt, T.; Nabo, O.

    1987-01-01

    The modern centrifugal separator is a fluid machine where the high ''G'' forces set up by rotation are utilized to separate phases of different densities. The fluid dynamics of the separator is complex and poorly known. Hundred years of (practical) experience has, however, turned the separator into an efficient machine. The present report shows how straight forward visualization experiments in model rigs provide valuable information on the flow inside the separator. The report concentrates on describing the flow between the closely spaced discs in a separator disc stack

  7. Flow visualization in heat-generating porous media

    International Nuclear Information System (INIS)

    Lee, D.O.; Nilson, R.H.

    1977-11-01

    The work reported is in support of the Sandia Post-Accident Heat Removal Program, in which simulated LMFBR beds will be subjected to in-pile heating in the ACPR (Annular Core Pulsed Reactor). Flow visualization experiments were performed to gain some insight into the flow patterns and temperature distributions in a fluid-saturated heat-generating porous medium. Although much of the information presented is of a qualitative nature, it is useful in the recognition of the controlling transport process and in the formulation of analytic and numerical models

  8. 3D flow visualizations by means of laser beam sweeps

    International Nuclear Information System (INIS)

    Prenel, J.P.; Porcar, R.; Diemunsch, G.

    1987-01-01

    A method in which two-dimensional aperiodic or periodic sweeps are used to produce three-dimensional light sweeps makes possible the quasi-simultaneous recording of different specific planes of a flow, or the characterization of a fluid without revolution symmetry. The optical device consists of two scanners (whose axes are orthogonal) set into a telescope, allowing fine focusing of the light sheets in the study zone. The method also allows visualizations on skewed surfaces, particularly those of flows without a cylindrical geometry; it is applicable from low velocity, as in heat convection, to supersonic velocity, as in the analysis of a nonaxisymmetric ejector. 8 references

  9. Decoding complex flow-field patterns in visual working memory.

    Science.gov (United States)

    Christophel, Thomas B; Haynes, John-Dylan

    2014-05-01

    There has been a long history of research on visual working memory. Whereas early studies have focused on the role of lateral prefrontal cortex in the storage of sensory information, this has been challenged by research in humans that has directly assessed the encoding of perceptual contents, pointing towards a role of visual and parietal regions during storage. In a previous study we used pattern classification to investigate the storage of complex visual color patterns across delay periods. This revealed coding of such contents in early visual and parietal brain regions. Here we aim to investigate whether the involvement of visual and parietal cortex is also observable for other types of complex, visuo-spatial pattern stimuli. Specifically, we used a combination of fMRI and multivariate classification to investigate the retention of complex flow-field stimuli defined by the spatial patterning of motion trajectories of random dots. Subjects were trained to memorize the precise spatial layout of these stimuli and to retain this information during an extended delay. We used a multivariate decoding approach to identify brain regions where spatial patterns of activity encoded the memorized stimuli. Content-specific memory signals were observable in motion sensitive visual area MT+ and in posterior parietal cortex that might encode spatial information in a modality independent manner. Interestingly, we also found information about the memorized visual stimulus in somatosensory cortex, suggesting a potential crossmodal contribution to memory. Our findings thus indicate that working memory storage of visual percepts might be distributed across unimodal, multimodal and even crossmodal brain regions. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. Flow instability and turbulence - ONERA water tunnel visualizations

    Science.gov (United States)

    Werle, H.

    The experimental technique used for visualizing laminar-turbulent transition phenomena, developed in previous tests in ONERA's small TH1 water tunnel, has been successfully applied in the new TH2 tunnel. With its very extensive Reynold's number domain (10 to the 4th - 10 to the 6th), this tunnel has shown itself to be well adapted to the study of turbulence and of the flow instabilities related to its appearance.

  11. Methods of Visually Determining the Air Flow Around Airplanes

    Science.gov (United States)

    Gough, Melvin N; Johnson, Ernest

    1932-01-01

    This report describes methods used by the National Advisory Committee for Aeronautics to study visually the air flow around airplanes. The use of streamers, oil and exhaust gas streaks, lampblack and kerosene, powdered materials, and kerosene smoke is briefly described. The generation and distribution of smoke from candles and from titanium tetrachloride are described in greater detail because they appear most advantageous for general application. Examples are included showing results of the various methods.

  12. The art and science of flow control - case studies using flow visualization methods

    Science.gov (United States)

    Alvi, F. S.; Cattafesta, L. N., III

    2010-04-01

    Active flow control (AFC) has been the focus of significant research in the last decade. This is mainly due to the potentially substantial benefits it affords. AFC applications range from the subsonic to the supersonic (and beyond) regime for both internal and external flows. These applications are wide and varied, such as controlling flow transition and separation over various external components of the aircraft to active management of separation and flow distortion in engine components and over turbine and compressor blades. High-speed AFC applications include control of flow oscillations in cavity flows, supersonic jet screech, impinging jets, and jet-noise control. In this paper we review some of our recent applications of AFC through a number of case studies that illustrate the typical benefits as well as limitations of present AFC methods. The case studies include subsonic and supersonic canonical flowfields such as separation control over airfoils, control of supersonic cavity flows and impinging jets. In addition, properties of zero-net mass-flux (ZNMF) actuators are also discussed as they represent one of the most widely studied actuators used for AFC. In keeping with the theme of this special issue, the flowfield properties and their response to actuation are examined through the use of various qualitative and quantitative flow visualization methods, such as smoke, shadowgraph, schlieren, planar-laser scattering, and Particle image velocimetry (PIV). The results presented here clearly illustrate the merits of using flow visualization to gain significant insight into the flow and its response to AFC.

  13. Visualization of bubble behaviors in forced convective subcooled flow boiling

    International Nuclear Information System (INIS)

    Inaba, Noriaki; Matsuzaki, Mitsuo; Kikura, Hiroshige; Aritomi, Masanori; Komeno, Toshihiro

    2007-01-01

    Condensation characteristics of vapor bubble after the departure from a heated section in forced convective subcooled flow boiling were studied visually by using a high speed camera. The purpose of the present study was to measure two-phase flow parameters in subcooled flow boiling. These two-phase flow parameters are void fraction, interfacial area concentration and Sauter mean diameter, which express bubble interface behaviors. The experimental set-up was designed to measure the two-phase flow parameters necessary for developing composite equations for the two fluid models in subcooled flow boiling. In the present experiments, the mass flux, liquid subcooling and the heater were varied within 100-1000kg/m 2 s, 2-10K and 100-300kW/m 2 respectively. Under these experimental conditions, the bubble images were obtained by a high-speed camera, and analyzed paying attention to the condensation of vapor bubbles. These two-phase parameters were obtained by the experimental data, such as the bubble parameter, the bubble volume and the bubble surface. In the calculation process of the two phase flow parameters, it was confirmed that these parameters are related to the void fraction. (author)

  14. Flow visualization IV; Proceedings of the Fourth International Symposium, Ecole Nationale Superieure de Techniques Avancees, Paris, France, Aug. 26-29, 1986

    International Nuclear Information System (INIS)

    Veret, C.

    1987-01-01

    Papers are presented on optical techniques, speckle techniques, observation methods, image processing, boundary layers and separated flows, stratified flows and the mixing layer, vortices and wakes, jets, supersonic and hypersonic flows, the velocity field, two-phase flows, heat transfer, and engines. Specific attention is paid to applications including shear layer stability in axisymmetric backstep flows, visualization of the pulsating flow past aortic prostheses, and flow visualization by dye and by optical interferometry. Other topics include photochromic flow visualization in liquid-liquid two-phase flow, shear flow patterns analyzed by video systems, the visualization of longitudinal vortices in stagnation flows, and the development of the Karman vortex due to buoyant force in opposing flow

  15. MotionFlow: Visual Abstraction and Aggregation of Sequential Patterns in Human Motion Tracking Data.

    Science.gov (United States)

    Jang, Sujin; Elmqvist, Niklas; Ramani, Karthik

    2016-01-01

    Pattern analysis of human motions, which is useful in many research areas, requires understanding and comparison of different styles of motion patterns. However, working with human motion tracking data to support such analysis poses great challenges. In this paper, we propose MotionFlow, a visual analytics system that provides an effective overview of various motion patterns based on an interactive flow visualization. This visualization formulates a motion sequence as transitions between static poses, and aggregates these sequences into a tree diagram to construct a set of motion patterns. The system also allows the users to directly reflect the context of data and their perception of pose similarities in generating representative pose states. We provide local and global controls over the partition-based clustering process. To support the users in organizing unstructured motion data into pattern groups, we designed a set of interactions that enables searching for similar motion sequences from the data, detailed exploration of data subsets, and creating and modifying the group of motion patterns. To evaluate the usability of MotionFlow, we conducted a user study with six researchers with expertise in gesture-based interaction design. They used MotionFlow to explore and organize unstructured motion tracking data. Results show that the researchers were able to easily learn how to use MotionFlow, and the system effectively supported their pattern analysis activities, including leveraging their perception and domain knowledge.

  16. Visualization study of helium-air counter flow through a small opening

    International Nuclear Information System (INIS)

    Fumizawa, Motoo

    2007-01-01

    Buoyancy-driven counter flows of helium-air were investigated through horizontal and inclined small openings. Counter flows may occur following a window opening as ventilation, fire in the room as well as a pipe rupture accident in a high temperature gas-cooled nuclear reactor. The experiment has carried out by a test chamber filled with helium and flow was visualized by the smoke wire method. The flow behavior has recorded by a high-speed camera with a computer system. The image of the flow was transferred to the digital data, thus the flow velocity was measured by PTV software. The mass fraction in the test chamber was measured by electronic balance. The detected data was arranged by the densimetric Floude number of the counter flow rate that derived from the dimensional analysis. The method of mass increment was developed and applied to measure the counter flow rate. By removing the cover plate placed on the top of the opening, the counter flow initiated. Air enters the test chamber and the mass of the gas mixture in the test chamber increased. The volumetric counter flow rate was evaluated from the mass increment data. In the case of inclination openings, the results of both methods were compared. The inclination angle for maximum densimetric Floude number decreased with increasing length-to-diameter ratio of the opening. For a horizontal opening, the results from the method of mass increment agreed with those obtained by other authors for a water-brine system. (author)

  17. Experimental investigation of the mutual interference flow of two circular cylinders by flow visualization

    Science.gov (United States)

    Yokoi, Yoshifumi; Vitkovičová, Rut

    In order to understand the aspect of the mutual interference flow from two circular cylinders, the visual observation experiment was performed by use a water flow apparatus. The purpose of this study is accumulation of the basic image data for comparing with numerical computation or previous experimental results. In this report, the intervals of two circular cylinders were varied, the visualization experiment was performed, and the vortex shedding characteristics and the flow pattern in each case were investigated. The cylinder setting conditions were seven kinds (the position of the rear-side circular cylinder is changed). The cylinder diameter ratios were four kinds (D/d=1.0, 1.67, 2.5 and 5.0). The variation of Reynolds number was three kinds (Re=548.7, 1200 and 2500). The dye oozing streak method was used in this visualization experiment. Although the previous PIV experimental result and present result obtained the same flow feature, the aspect of an interference flow became clear by changing the color of tracer ink.

  18. Experimental investigation of the mutual interference flow of two circular cylinders by flow visualization

    Directory of Open Access Journals (Sweden)

    Yokoi Yoshifumi

    2017-01-01

    Full Text Available In order to understand the aspect of the mutual interference flow from two circular cylinders, the visual observation experiment was performed by use a water flow apparatus. The purpose of this study is accumulation of the basic image data for comparing with numerical computation or previous experimental results. In this report, the intervals of two circular cylinders were varied, the visualization experiment was performed, and the vortex shedding characteristics and the flow pattern in each case were investigated. The cylinder setting conditions were seven kinds (the position of the rear-side circular cylinder is changed. The cylinder diameter ratios were four kinds (D/d=1.0, 1.67, 2.5 and 5.0. The variation of Reynolds number was three kinds (Re=548.7, 1200 and 2500. The dye oozing streak method was used in this visualization experiment. Although the previous PIV experimental result and present result obtained the same flow feature, the aspect of an interference flow became clear by changing the color of tracer ink.

  19. Efficient Unsteady Flow Visualization with High-Order Access Dependencies

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jiang; Guo, Hanqi; Yuan, Xiaoru

    2016-04-19

    We present a novel high-order access dependencies based model for efficient pathline computation in unsteady flow visualization. By taking longer access sequences into account to model more sophisticated data access patterns in particle tracing, our method greatly improves the accuracy and reliability in data access prediction. In our work, high-order access dependencies are calculated by tracing uniformly-seeded pathlines in both forward and backward directions in a preprocessing stage. The effectiveness of our proposed approach is demonstrated through a parallel particle tracing framework with high-order data prefetching. Results show that our method achieves higher data locality and hence improves the efficiency of pathline computation.

  20. Flow visualization of bubble behavior under two-phase natural circulation flow conditions using high speed digital camera

    Energy Technology Data Exchange (ETDEWEB)

    Lemos, Wanderley F.; Su, Jian, E-mail: wlemos@con.ufrj.br, E-mail: sujian@lasme.coppe.ufrj.br [Coordenacao dos Programas de Pos-Graduacao em Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear; Faccini, Jose L.H., E-mail: faccini@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Lab. de Termo-Hidraulica Experimental

    2013-07-01

    The The present work aims at identifying flow patterns and measuring interfacial parameters in two-phase natural circulation by using visualization technique with high-speed digital camera. The experiments were conducted in the Natural Circulation Circuit (CCN), installed at Nuclear Engineering Institute/CNEN. The thermo-hydraulic circuit comprises heater, heat exchanger, expansion tank, the pressure relief valve and pipes to interconnect the components. A glass tube is installed at the midpoint of the riser connected to the heater outlet. The natural circulation circuit is complemented by acquisition system of values of temperatures, flow and graphic interface. The instrumentation has thermocouples, volumetric flow meter, rotameter and high-speed digital camera. The experimental study is performed through analysis of information from measurements of temperatures at strategic points along the hydraulic circuit, besides natural circulation flow rates. The comparisons between analytical and experimental values are validated by viewing, recording and processing of the images for the flows patterns. Variables involved in the process of identification of flow regimes, dimensionless parameters, the phase velocity of the flow, initial boiling point, the phenomenon of 'flashing' pre-slug flow type were obtained experimentally. (author)

  1. Flow visualization of bubble behavior under two-phase natural circulation flow conditions using high speed digital camera

    International Nuclear Information System (INIS)

    Lemos, Wanderley F.; Su, Jian; Faccini, Jose L.H.

    2013-01-01

    The The present work aims at identifying flow patterns and measuring interfacial parameters in two-phase natural circulation by using visualization technique with high-speed digital camera. The experiments were conducted in the Natural Circulation Circuit (CCN), installed at Nuclear Engineering Institute/CNEN. The thermo-hydraulic circuit comprises heater, heat exchanger, expansion tank, the pressure relief valve and pipes to interconnect the components. A glass tube is installed at the midpoint of the riser connected to the heater outlet. The natural circulation circuit is complemented by acquisition system of values of temperatures, flow and graphic interface. The instrumentation has thermocouples, volumetric flow meter, rotameter and high-speed digital camera. The experimental study is performed through analysis of information from measurements of temperatures at strategic points along the hydraulic circuit, besides natural circulation flow rates. The comparisons between analytical and experimental values are validated by viewing, recording and processing of the images for the flows patterns. Variables involved in the process of identification of flow regimes, dimensionless parameters, the phase velocity of the flow, initial boiling point, the phenomenon of 'flashing' pre-slug flow type were obtained experimentally. (author)

  2. OpinionFlow: Visual Analysis of Opinion Diffusion on Social Media.

    Science.gov (United States)

    Wu, Yingcai; Liu, Shixia; Yan, Kai; Liu, Mengchen; Wu, Fangzhao

    2014-12-01

    It is important for many different applications such as government and business intelligence to analyze and explore the diffusion of public opinions on social media. However, the rapid propagation and great diversity of public opinions on social media pose great challenges to effective analysis of opinion diffusion. In this paper, we introduce a visual analysis system called OpinionFlow to empower analysts to detect opinion propagation patterns and glean insights. Inspired by the information diffusion model and the theory of selective exposure, we develop an opinion diffusion model to approximate opinion propagation among Twitter users. Accordingly, we design an opinion flow visualization that combines a Sankey graph with a tailored density map in one view to visually convey diffusion of opinions among many users. A stacked tree is used to allow analysts to select topics of interest at different levels. The stacked tree is synchronized with the opinion flow visualization to help users examine and compare diffusion patterns across topics. Experiments and case studies on Twitter data demonstrate the effectiveness and usability of OpinionFlow.

  3. Flow visualization around a rotating body in a wind tunnel

    Science.gov (United States)

    Hiraki, K.; Zaitsu, D.; Yanaga, Y.; Kleine, H.

    2017-02-01

    The rotational behavior of capsule-shaped models is investigated in the transonic wind tunnel of JAXA. A special support is developed to allow the model to rotate around the pitch, yaw and roll axes. This 3-DOF free rotational mounting apparatus achieves the least frictional torque from the support and the instruments. Two types of capsule models are prepared, one is drag type (SPH model) and the other is lift type (HTV-R model). The developed mounting apparatus is used in the wind tunnel tests with these capsule models. In a flow of Mach 0.9, the SPH model exhibits oscillations in pitch and yaw, and it rolls half a turn during the test. Similarly, the HTV-R model exhibits pitch and yaw oscillations in a flow of Mach 0.5. Moreover, it rolls multiple times during the test. In order to investigate the flow field around the capsule, the combined technique of color schlieren and surface tufts is applied. This visualization clearly shows the flow reattachment on the back surface of a capsule, which is suspected to induce the rapid rolling motion.

  4. Test Facility Construction for Flow Visualization on Mixing Flow inside Subchannels of PWR Rod Bundle

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seok; Jeon, Byong-Guk; Youn, Young-Jung; Choi, Hae-Seob; Euh, Dong-Jin [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    Flow inside rod bundles has a similarity with flow in porous media. To ensure thermal performance of a nuclear reactor, detailed information of the heat transfer and turbulent mixing flow phenomena taking place within the subchannels is required. The subchannel analysis is one of the key thermal-hydraulic calculations in the safety analysis of the nuclear reactor core. At present, subchannel computer codes are employed to simulate fuel elements of nuclear reactor cores and predict the performance of cores under normal operating and hypothetical accident conditions. The ability of these subchannels codes to predict both the flow and enthalpy distribution in fuel assemblies is very important in the design of nuclear reactors. Recently, according to the modern tend of the safety analysis for the nuclear reactor, a new component scale analysis code, named CUPID, and has been developed in KAERI. The CUPID code is based on a two-fluid and three-field model, and both the open and porous media approaches are incorporated. The PRIUS experiment has addressed many key topics related to flow behaviour in a rod bundle. These issues are related to the flow conditions inside a nuclear fuel element during normal operation of the plant or in accident scenarios. From the second half of 2016, flow visualization will be performed by using a high speed camera and image analysis technique, from which detailed information for the two-dimensional movement of single phase flow is quantified.

  5. Extracting quantitative three-dimensional unsteady flow direction from tuft flow visualizations

    Energy Technology Data Exchange (ETDEWEB)

    Omata, Noriyasu; Shirayama, Susumu, E-mail: omata@nakl.t.u-tokyo.ac.jp, E-mail: sirayama@sys.t.u-tokyo.ac.jp [Department of Systems Innovation, School of Engineering, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo, 113-8656 (Japan)

    2017-10-15

    We focus on the qualitative but widely used method of tuft flow visualization, and propose a method for quantifying it using information technology. By applying stereo image processing and computer vision, the three-dimensional (3D) flow direction in a real environment can be obtained quantitatively. In addition, we show that the flow can be divided temporally by performing appropriate machine learning on the data. Acquisition of flow information in real environments is important for design development, but it is generally considered difficult to apply simulations or quantitative experiments to such environments. Hence, qualitative methods including the tuft method are still in use today. Although attempts have been made previously to quantify such methods, it has not been possible to acquire 3D information. Furthermore, even if quantitative data could be acquired, analysis was often performed empirically or qualitatively. In contrast, we show that our method can acquire 3D information and analyze the measured data quantitatively. (paper)

  6. Extracting quantitative three-dimensional unsteady flow direction from tuft flow visualizations

    International Nuclear Information System (INIS)

    Omata, Noriyasu; Shirayama, Susumu

    2017-01-01

    We focus on the qualitative but widely used method of tuft flow visualization, and propose a method for quantifying it using information technology. By applying stereo image processing and computer vision, the three-dimensional (3D) flow direction in a real environment can be obtained quantitatively. In addition, we show that the flow can be divided temporally by performing appropriate machine learning on the data. Acquisition of flow information in real environments is important for design development, but it is generally considered difficult to apply simulations or quantitative experiments to such environments. Hence, qualitative methods including the tuft method are still in use today. Although attempts have been made previously to quantify such methods, it has not been possible to acquire 3D information. Furthermore, even if quantitative data could be acquired, analysis was often performed empirically or qualitatively. In contrast, we show that our method can acquire 3D information and analyze the measured data quantitatively. (paper)

  7. Using Visualization in Cockpit Decision Support Systems

    Energy Technology Data Exchange (ETDEWEB)

    Aragon, Cecilia R.

    2005-07-01

    In order to safely operate their aircraft, pilots must makerapid decisions based on integrating and processing large amounts ofheterogeneous information. Visual displays are often the most efficientmethod of presenting safety-critical data to pilots in real time.However, care must be taken to ensure the pilot is provided with theappropriate amount of information to make effective decisions and notbecome cognitively overloaded. The results of two usability studies of aprototype airflow hazard visualization cockpit decision support systemare summarized. The studies demonstrate that such a system significantlyimproves the performance of helicopter pilots landing under turbulentconditions. Based on these results, design principles and implicationsfor cockpit decision support systems using visualization arepresented.

  8. Oil flow at the scroll compressor discharge: visualization and CFD simulation

    Science.gov (United States)

    Xu, Jiu; Hrnjak, Pega

    2017-08-01

    Oil is important to the compressor but has other side effect on the refrigeration system performance. Discharge valves located in the compressor plenum are the gateway for the oil when leaving the compressor and circulate in the system. The space in between: the compressor discharge plenum has the potential to separate the oil mist and reduce the oil circulation ratio (OCR) in the system. In order to provide information for building incorporated separation feature for the oil flow near the compressor discharge, video processing method is used to quantify the oil droplets movement and distribution. Also, CFD discrete phase model gives the numerical approach to study the oil flow inside compressor plenum. Oil droplet size distributions are given by visualization and simulation and the results show a good agreement. The mass balance and spatial distribution are also discussed and compared with experimental results. The verification shows that discrete phase model has the potential to simulate the oil droplet flow inside the compressor.

  9. Virtual reality aided visualization of fluid flow simulations with application in medical education and diagnostics.

    Science.gov (United States)

    Djukic, Tijana; Mandic, Vesna; Filipovic, Nenad

    2013-12-01

    Medical education, training and preoperative diagnostics can be drastically improved with advanced technologies, such as virtual reality. The method proposed in this paper enables medical doctors and students to visualize and manipulate three-dimensional models created from CT or MRI scans, and also to analyze the results of fluid flow simulations. Simulation of fluid flow using the finite element method is performed, in order to compute the shear stress on the artery walls. The simulation of motion through the artery is also enabled. The virtual reality system proposed here could shorten the length of training programs and make the education process more effective. © 2013 Published by Elsevier Ltd.

  10. Visualization of boiling two-phase flow in a small diameter tube using neutron radiography

    International Nuclear Information System (INIS)

    Hibiki, Takashi; Mishima, Kaichiro; Yoneda, Kenji; Fujine, Shigenori; Kanda, Keiji; Nishihara, Hideaki

    1991-01-01

    The characteristics of boiling two-phase flow in a small diameter tube are very important for cooling the blanket in a nuclear fusion reactor or a high performance electronic device. For all these subjects, it is necessary to visualize the flow in a tube as a starting point of the study. However, when an optical method cannot be used for the visualization, it is expected that neutron radiography is useful. In this study, the feasibility of visualization of boiling two-phase flow in a small diameter tube was investigated by using various facilities of neutron radiography as the first step. The basic concept of neutron radiography and the block diagram of a neutron television system are shown. The neutron beam attenuated by water in the test section makes a scintillator emit visible light, and produces an image of two-phase flow, which is taken with a TV camera. Thus the image can be observed at real time. Three kinds of the experiments were performed with the facilities of KUR, NSRR and JRR-3. The experimental methods and the results are reported. The images obtained were sufficiently clear. (K.I.)

  11. Visual system manifestations of Alzheimer's disease.

    Science.gov (United States)

    Kusne, Yael; Wolf, Andrew B; Townley, Kate; Conway, Mandi; Peyman, Gholam A

    2017-12-01

    Alzheimer's disease (AD) is an increasingly common disease with massive personal and economic costs. While it has long been known that AD impacts the visual system, there has recently been an increased focus on understanding both pathophysiological mechanisms that may be shared between the eye and brain and how related biomarkers could be useful for AD diagnosis. Here, were review pertinent cellular and molecular mechanisms of AD pathophysiology, the presence of AD pathology in the visual system, associated functional changes, and potential development of diagnostic tools based on the visual system. Additionally, we discuss links between AD and visual disorders, including possible pathophysiological mechanisms and their relevance for improving our understanding of AD. © 2016 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  12. Flow visualization study of post-critical heat flux in inverted flow

    International Nuclear Information System (INIS)

    Babelli, I.; Revankar, S.T.; Ishii, M.

    1994-01-01

    A visual study of film boiling was carried out to determine the flow regime transition in the post-CHF region for a transient bottom reflooding of a hot transparent test section. The effect of test liquid subcooling and inlet velocity on flow transition as well as on the quench front propagation was investigated. The respective ranges for liquid velocity and subcooling were 1.8-26.8 cm/s, and 20-45 C, respectively. The test liquid was Freon 113 which was introduced into the bottom of the quartz test section whose walls were maintained well above the film boiling temperature of the test liquid, via a transparent heat transfer fluid. The flow regimes observed down stream of the upward moving quench front were the rough wavy, the agitated, and the dispersed droplet/ligaments in agreement with a steady state, two-phase core injection study carried on recently by one of the authors. A correlation for the flow regime transition between the inverted annular and the dispersed droplet/ligament flow patterns was developed. The correlation showed a marked dependence on the void fraction at the CHF location and hence on the flow regime encountered in the pre-CHF region. (orig.)

  13. Flow visualization of forced and natural convection in internal cavities. 1998 annual progress report

    International Nuclear Information System (INIS)

    Brodkey, R.S.; Clarksean, R.; Crepeau, J.C.; Guezennec, Y.G.; McEligot, D.M.

    1998-01-01

    'The objective of this research program is to understand the fluid physics when corroded spent nuclear fuel (SNF) elements are passivated by injecting treatment gases into a storage canister. By developing a reliable predictive technique for the energy, mass, and momentum transfer in the presence of surface reactions, transfer and storage systems can be efficiently and safely designed. The objective will be reached by using innovative flow visualization techniques and experimental measurements of the flow field to support computational models. This report summarizes work completed after eight months of a three-year, collaborative project. A generic idealization of a combined drying and passivation approach has been defined, which represents a section of a vertical canister with baskets of SNF elements. This simulation includes flow phenomena that occur in canisters for high- and/or low-enrichment fuels. A steady flow of the passivation fluid is introduced at the bottom of the canister via a central tube from the top. Fluid flows through an array of holes in the perforated basket support plate then around the simulated elements and out the top. Dimensions and flow rates for the idealized situation correspond to those for typical drying canisters. Approximate calculations have identified the ranges of values of flow parameters needed to determine the flow regimes occurring in practice.'

  14. A visualization study of flow-induced acoustic resonance in a branched pipe

    International Nuclear Information System (INIS)

    Li, Yanrong; Someya, Satoshi; Okamoto, Koji

    2008-01-01

    Systems with closed side-branches are liable to an excitation of sound, as called cavity tones. It may occur in pipe branches leading to safety valves or to boiler relief valves. The outbreak mechanism of the cavity tone has been known by phase-averaged measurement in previous researches, while the relation between sound propagation and flow field is still unclear due to the difficulty of detecting instantaneous pressure field. High time-resolved PIV has a possibility to analyze the pressure field and the relation mentioned above. In this report, flow-induced acoustic resonances of piping system containing closed side-branches were investigated experimentally. A High-Time-Resolved PIV technique was applied to measure a gas-flow in a cavity-tone. Air flow containing an oil mist as tracer particles was measured using a high frequency pulse laser and a high-speed camera. The present investigation on the coaxial closed side-branches is the first rudimentary study to measure the flow field two-dimensionally and simultaneously with the pressure measurement at multi-points and to visualize the fluid flow in the cross-section by using PIV. The fluid flows at different points in the cavity interact with some phase differences and the relation should be clarified. (author)

  15. Visualization framework for CAVE virtual reality systems

    OpenAIRE

    Kageyama, Akira; Tomiyama, Asako

    2016-01-01

    We have developed a software framework for scientific visualization in immersive-type, room-sized virtual reality (VR) systems, or Cave automatic virtual environment (CAVEs). This program, called Multiverse, allows users to select and invoke visualization programs without leaving CAVE’s VR space. Multiverse is a kind of immersive “desktop environment” for users, with a three-dimensional graphical user interface. For application developers, Multiverse is a software framework with useful class ...

  16. Turbulent subcooled boiling flow visualization experiments through a rectangular channel

    International Nuclear Information System (INIS)

    Estrada-Perez, Carlos E.; Dominguez-Ontiveros, Elvis E.; Hassan, Yassin A.

    2008-01-01

    Full text of publication follows: Proper characterization of subcooled boiling flow is of importance in many applications. It is of exceptional significance in the development of empirical models for the design of nuclear reactors, steam generators, and refrigeration systems. Most of these models are based on experimental studies that share the characteristics of utilizing point measurement probes with high temporal resolution, e.g. Hot Film Anemometry (HFA), Laser Doppler Velocimetry (LDV), and Fiber Optic Probes (FOP). However there appears to be a scarcity of experimental studies that can capture instantaneous whole-field measurements with a fast time response. Particle Tracking Velocimetry (PTV) may be used to overcome the limitations associated with point measurement techniques. PTV is a whole-flow-field technique providing instantaneous velocity vectors capable of high spatial and temporal resolution. PTV is also an exceptional tool for the analysis of boiling flow due to its ability to differentiate between the gas and liquid phases and subsequently deliver independent velocity fields associated with each phase. In this work, using PTV, liquid velocity fields of a turbulent subcooled boiling flow in a rectangular channel were successfully obtained. The present results agree with similar studies that used point measurement probes. However, the present study provides additional information; not only averaged profiles of the velocity components were obtained, instantaneous 2-D velocity fields were also readily available with a high temporal and spatial resolution. Analysis of fluctuating velocities, Reynolds stresses, and higher order statistics of the flow are presented. This work is an attempt to enrich the database already collected on turbulent subcooled boiling flow, with the hope that it will be useful in turbulence modeling efforts. (authors)

  17. Information processing in the primate visual system - An integrated systems perspective

    Science.gov (United States)

    Van Essen, David C.; Anderson, Charles H.; Felleman, Daniel J.

    1992-01-01

    The primate visual system contains dozens of distinct areas in the cerebral cortex and several major subcortical structures. These subdivisions are extensively interconnected in a distributed hierarchical network that contains several intertwined processing streams. A number of strategies are used for efficient information processing within this hierarchy. These include linear and nonlinear filtering, passage through information bottlenecks, and coordinated use of multiple types of information. In addition, dynamic regulation of information flow within and between visual areas may provide the computational flexibility needed for the visual system to perform a broad spectrum of tasks accurately and at high resolution.

  18. Information Processing in the Primate Visual System: An Integrated Systems Perspective

    Science.gov (United States)

    van Essen, David C.; Anderson, Charles H.; Felleman, Daniel J.

    1992-01-01

    The primate visual system contains dozens of distinct areas in the cerebral cortex and several major subcortical structures. These subdivisions are extensively interconnected in a distributed hierarchical network that contains several intertwined processing streams. A number of strategies are used for efficient information processing within this hierarchy. These include linear and nonlinear filtering, passage through information bottlenecks, and coordinated use of multiple types of information. In addition, dynamic regulation of information flow within and between visual areas may provide the computational flexibility needed for the visual system to perform a broad spectrum of tasks accurately and at high resolution.

  19. Scientific & Intelligence Exascale Visualization Analysis System

    Energy Technology Data Exchange (ETDEWEB)

    2017-07-14

    SIEVAS provides an immersive visualization framework for connecting multiple systems in real time for data science. SIEVAS provides the ability to connect multiple COTS and GOTS products in a seamless fashion for data fusion, data analysis, and viewing. It provides this capability by using a combination of micro services, real time messaging, and web service compliant back-end system.

  20. #FluxFlow: Visual Analysis of Anomalous Information Spreading on Social Media.

    Science.gov (United States)

    Zhao, Jian; Cao, Nan; Wen, Zhen; Song, Yale; Lin, Yu-Ru; Collins, Christopher

    2014-12-01

    We present FluxFlow, an interactive visual analysis system for revealing and analyzing anomalous information spreading in social media. Everyday, millions of messages are created, commented, and shared by people on social media websites, such as Twitter and Facebook. This provides valuable data for researchers and practitioners in many application domains, such as marketing, to inform decision-making. Distilling valuable social signals from the huge crowd's messages, however, is challenging, due to the heterogeneous and dynamic crowd behaviors. The challenge is rooted in data analysts' capability of discerning the anomalous information behaviors, such as the spreading of rumors or misinformation, from the rest that are more conventional patterns, such as popular topics and newsworthy events, in a timely fashion. FluxFlow incorporates advanced machine learning algorithms to detect anomalies, and offers a set of novel visualization designs for presenting the detected threads for deeper analysis. We evaluated FluxFlow with real datasets containing the Twitter feeds captured during significant events such as Hurricane Sandy. Through quantitative measurements of the algorithmic performance and qualitative interviews with domain experts, the results show that the back-end anomaly detection model is effective in identifying anomalous retweeting threads, and its front-end interactive visualizations are intuitive and useful for analysts to discover insights in data and comprehend the underlying analytical model.

  1. Geometric Optimization for Non-Thrombogenicity of a Centrifugal Blood Pump through Flow Visualization

    Science.gov (United States)

    Toyoda, Masahiro; Nishida, Masahiro; Maruyama, Osamu; Yamane, Takashi; Tsutsui, Tatsuo; Sankai, Yoshiyuki

    A monopivot centrifugal blood pump, whose impeller is supported with a pivot bearing and a passive magnetic bearing, is under development for implantable artificial heart. The hemolysis level is less than that of commercial centrifugal pumps and the pump size is as small as 160 mL in volume. To solve a problem of thrombus caused by fluid dynamics, flow visualization experiments and animal experiments have been undertaken. For flow visualization a three-fold scale-up model, high-speed video system, and particle tracking velocimetry software were used. To verify non-thrombogenicity one-week animal experiments were conducted with sheep. The initially observed thrombus around the pivot was removed through unifying the separate washout holes to a small centered hole to induce high shear around the pivot. It was found that the thrombus contours corresponded to the shear rate of 300s-1 for red thrombus and 1300-1700s-1 for white thrombus, respectively. Thus flow visualization technique was found to be a useful tool to predict thrombus location.

  2. Visualizing complex (hydrological) systems with correlation matrices

    Science.gov (United States)

    Haas, J. C.

    2016-12-01

    When trying to understand or visualize the connections of different aspects of a complex system, this often requires deeper understanding to start with, or - in the case of geo data - complicated GIS software. To our knowledge, correlation matrices have rarely been used in hydrology (e.g. Stoll et al., 2011; van Loon and Laaha, 2015), yet they do provide an interesting option for data visualization and analysis. We present a simple, python based way - using a river catchment as an example - to visualize correlations and similarities in an easy and colorful way. We apply existing and easy to use python packages from various disciplines not necessarily linked to the Earth sciences and can thus quickly show how different aquifers work or react, and identify outliers, enabling this system to also be used for quality control of large datasets. Going beyond earlier work, we add a temporal and spatial element, enabling us to visualize how a system reacts to local phenomena such as for example a river, or changes over time, by visualizing the passing of time in an animated movie. References: van Loon, A.F., Laaha, G.: Hydrological drought severity explained by climate and catchment characteristics, Journal of Hydrology 526, 3-14, 2015, Drought processes, modeling, and mitigation Stoll, S., Hendricks Franssen, H. J., Barthel, R., Kinzelbach, W.: What can we learn from long-term groundwater data to improve climate change impact studies?, Hydrology and Earth System Sciences 15(12), 3861-3875, 2011

  3. Using Visualization in Cockpit Decision Support Systems

    Science.gov (United States)

    Aragon, Cecilia R.

    2005-01-01

    In order to safely operate their aircraft, pilots must make rapid decisions based on integrating and processing large amounts of heterogeneous information. Visual displays are often the most efficient method of presenting safety-critical data to pilots in real time. However, care must be taken to ensure the pilot is provided with the appropriate amount of information to make effective decisions and not become cognitively overloaded. The results of two usability studies of a prototype airflow hazard visualization cockpit decision support system are summarized. The studies demonstrate that such a system significantly improves the performance of helicopter pilots landing under turbulent conditions. Based on these results, design principles and implications for cockpit decision support systems using visualization are presented.

  4. Visualization of two-phase flow in metallic pipes using neutron radiographic technique

    International Nuclear Information System (INIS)

    Luiz, L.C.; Crispim, V.R.

    2007-01-01

    The study of two-phase flow is a matter of great interest both for the engineering and oil industries. The production of oil and natural gas involves the transportation of fluids in their liquid and gaseous states, respectively, to the processing plant for refinement. The forecasting of two-phase flow in oil pipes is of the utmost important yet an extremely difficult task. With the development of the electronic imaging system, installed in J-9 irradiation channel of the IEN/CNEN Argonauta Reactor, it is possible to visualize the different types of two phase air-water flows in small-diameter metallic pipes. After developing the captured image the liquid-gas drift flux correlation as well as the void fraction in relation to the injected air outflow for a fixed water outflow can be obtained. (author)

  5. Investigation of flow mechanism of a robotic fish swimming by using flow visualization synchronized with hydrodynamic force measurement

    Science.gov (United States)

    Tan, Guang-Kun; Shen, Gong-Xin; Huang, Shuo-Qiao; Su, Wen-Han; Ke, Yu

    When swimming in water by flapping its tail, a fish can overcome the drag from uniform flow and propel its body. The involved flow mechanism concerns 3-D and unsteady effects. This paper presents the investigation of the flow mechanism on the basis of a 3-D robotic fish model which has the typical geometry of body and tail with periodic flapping 2-freedom kinematical motion testing in the case of St = 0.78, Re = 6,600 and phase delay mode (φ = - 75°), in which may have a greater or maximum propulsion (without consideration of the optimal efficiency). Using a special technique of dye visualization which can clearly show vortex sheet and vortices in detail and using the inner 3-component force balance and cable supporting system with the phase-lock technique, the 3-D flow structure visualized in the wake of fish and the hydrodynamic force measurement were synchronized and obtained. Under the mentioned flapping parameters, we found the key flow structure and its evolution, a pair of complex 3-D chain-shape vortex (S-H vortex-rings, S1 - H1 and S2 - H2, and their legs L1 and L2) flow structures, which attach the leading edge and the trailing edge, then shed, move downstream and outwards and distribute two antisymmetric staggering arrays along with the wake of the fish model in different phase stages during the flapping period. It is different with in the case of St = 0.25-0.35. Its typical flow structure and evolution are described and the results prove that they are different from the viewpoints based on the investigation of 2-D cases. For precision of the dynamic force measurement, in this paper it was provided with the method and techniques by subtracting the inertial forces and the forces induced by buoyancy and gravity effect in water, etc. from original data measured. The evolution of the synchronized measuring forces directly matching with the flow structure was also described in this paper.

  6. Investigation and visualization of internal flow through particle aggregates and microbial flocs using particle image velocimetry.

    Science.gov (United States)

    Xiao, Feng; Lam, Kit Ming; Li, Xiao-yan

    2013-05-01

    An advanced particle-tracking and flow-visualization technology, particle image velocimetry (PIV), was utilized to investigate the hydrodynamic properties of large aggregates in water. The laser-based PIV system was used together with a settling column to capture the streamlines around two types of aggregates: latex particle aggregates and activated sludge (AS) flocs. Both types of the aggregates were highly porous and fractal with fractal dimensions of 2.13±0.31 for the latex particle aggregates (1210-2144 μm) and 1.78±0.24 for the AS flocs (1265-3737 μm). The results show that PIV is a powerful flow visualization technique capable of determining flow field details at the micrometer scale around and through settling aggregates and flocs. The PIV streamlines provided direct experimental proof of internal flow through the aggregate interiors. According to the PIV images, fluid collection efficiency ranged from 0.052 to 0.174 for the latex particle aggregates and from 0.008 to 0.126 for AS flocs. AS flocs are apparently less permeable than the particle aggregates, probably due to the extracellular polymeric substances (EPSs) produced by bacteria clogging the pores within the flocs. The internal permeation of fractal aggregates and bio-flocs would enhance flocculation between particles and material transport into the aggregates. Copyright © 2013 Elsevier Inc. All rights reserved.

  7. A Visual Formalism for Interacting Systems

    Directory of Open Access Journals (Sweden)

    Paul C. Jorgensen

    2015-04-01

    Full Text Available Interacting systems are increasingly common. Many examples pervade our everyday lives: automobiles, aircraft, defense systems, telephone switching systems, financial systems, national governments, and so on. Closer to computer science, embedded systems and Systems of Systems are further examples of interacting systems. Common to all of these is that some "whole" is made up of constituent parts, and these parts interact with each other. By design, these interactions are intentional, but it is the unintended interactions that are problematic. The Systems of Systems literature uses the terms "constituent systems" and "constituents" to refer to systems that interact with each other. That practice is followed here. This paper presents a visual formalism, Swim Lane Event-Driven Petri Nets, that is proposed as a basis for Model-Based Testing (MBT of interacting systems. In the absence of available tools, this model can only support the offline form of Model-Based Testing.

  8. Pulse-Flow Microencapsulation System

    Science.gov (United States)

    Morrison, Dennis R.

    2006-01-01

    The pulse-flow microencapsulation system (PFMS) is an automated system that continuously produces a stream of liquid-filled microcapsules for delivery of therapeutic agents to target tissues. Prior microencapsulation systems have relied on batch processes that involve transfer of batches between different apparatuses for different stages of production followed by sampling for acquisition of quality-control data, including measurements of size. In contrast, the PFMS is a single, microprocessor-controlled system that performs all processing steps, including acquisition of quality-control data. The quality-control data can be used as real-time feedback to ensure the production of large quantities of uniform microcapsules.

  9. Flow visualizations, velocity measurements, and surface convection measurements in simulated 20.8-cm Nova box amplifier cavities

    International Nuclear Information System (INIS)

    Julien, J.L.; Molishever, E.L.

    1983-01-01

    Reported are fluid mechanics experiments performed in models of the 20.8-cm Nova amplifier lamp and disk cavities. Lamp cavity nitrogen flows are shown, by both flow visualization and velocity measurements, to be acceptably uniform and parallel to the flashlamps. In contrast, the nitrogen flows in the disk cavity are shown to be disordered. Even though disk cavity flows are disordered, the simplest of three proposed nitrogen introduction systems for the disk cavity was found to be acceptable based on convection measurements made at the surfaces of simulated laser disks

  10. Art, illusion and the visual system.

    Science.gov (United States)

    Livingstone, M S

    1988-01-01

    The verve of op art, the serenity of a pointillist painting and the 3-D puzzlement of an Escher print derive from the interplay of the art with the anatomy of the visual system. Color, shape and movement are each processed separately by different structures in the eye and brain and then are combined to produce the experience we call perception.

  11. Thermofluid experiments for Fusion Reactor Safety. Visualization of exchange flows through breaches of a vacuum vessel in a fusion reactor under the LOVA condition

    International Nuclear Information System (INIS)

    Fujii, Sadao; Shibazaki, Hiroaki; Takase, Kazuyuki; Kunugi, Tomoaki.

    1997-01-01

    Exchange flow rates through breaches of a vacuum vessel in a fusion reactor under the LOVA (Loss of VAcuum event) conditions were measured quantitatively by using a preliminary LOVA apparatus and exchange flow patterns over the breach were visualized qualitatively by smoke. Velocity distributions in the exchange flows were predicted from the observed flow patterns by using the correlation method in the flow visualization procedures. Mean velocities calculated from the predicted velocity distributions at the outside of the breach were in good agreement with the LOVA experimental results when the exchange flow velocities were low. It was found that the present flow visualization and the image processing system might be an useful procedure to evaluate the exchange flow rates. (author)

  12. Visualized investigation on flow regimes for vertical upward steam–water flow in a heated narrow rectangular channel

    International Nuclear Information System (INIS)

    Wang Junfeng; Huang Yanping; Wang Yanlin; Song Mingliang

    2012-01-01

    Highlights: ► Flow regimes were visually investigated in a heated narrow rectangular channel. ► Bubbly, churn, and annular flow were observed. Slug flow was never observed. ► Flow regime transition boundary could be predicted by existing criteria. ► Churn zone in present flow regime maps were poorly predicted by existing criteria. - Abstract: Flow regimes are very important in understanding two-phase flow resistance and heat transfer characteristics. In present work, two-phase flow regimes for steam–water flows in a single-side heated narrow rectangular channel, having a width of 40 mm and a gap of 3 mm, were visually studied at relatively low pressure and low mass flux condition. The flow regimes observed in this experiment could be classified into bubbly, churn and annular flow. Slug flow was never observed at any of the conditions in our experiment. Flow regime maps at the pressure of 0.7 MPa and 1.0 MPa were developed, and then the pressure effect on flow regime transition was analyzed. Based on the experimental results, the comparisons with some existing flow regime maps and transition criteria were conducted. The comparison results show that the bubbly transition boundary and annular formation boundary of heated steam–water flow were consistent with that of adiabatic air–water flow. However, the intermediate flow pattern between bubbly and annular flow was different. Hibiki and Mishima criteria could predict the bubbly transition boundary and annular formation boundary satisfactorily, but it poorly predicted churn zone in present experimental data.

  13. Dependency visualization for complex system understanding

    Energy Technology Data Exchange (ETDEWEB)

    Smart, J. Allison Cory [Univ. of California, Davis, CA (United States)

    1994-09-01

    With the volume of software in production use dramatically increasing, the importance of software maintenance has become strikingly apparent. Techniques now sought and developed for reverse engineering and design extraction and recovery. At present, numerous commercial products and research tools exist which are capable of visualizing a variety of programming languages and software constructs. The list of new tools and services continues to grow rapidly. Although the scope of the existing commercial and academic product set is quite broad, these tools still share a common underlying problem. The ability of each tool to visually organize object representations is increasingly impaired as the number of components and component dependencies within systems increases. Regardless of how objects are defined, complex ``spaghetti`` networks result in nearly all large system cases. While this problem is immediately apparent in modem systems analysis involving large software implementations, it is not new. As will be discussed in Chapter 2, related problems involving the theory of graphs were identified long ago. This important theoretical foundation provides a useful vehicle for representing and analyzing complex system structures. While the utility of directed graph based concepts in software tool design has been demonstrated in literature, these tools still lack the capabilities necessary for large system comprehension. This foundation must therefore be expanded with new organizational and visualization constructs necessary to meet this challenge. This dissertation addresses this need by constructing a conceptual model and a set of methods for interactively exploring, organizing, and understanding the structure of complex software systems.

  14. Cascade redox flow battery systems

    Science.gov (United States)

    Horne, Craig R.; Kinoshita, Kim; Hickey, Darren B.; Sha, Jay E.; Bose, Deepak

    2014-07-22

    A reduction/oxidation ("redox") flow battery system includes a series of electrochemical cells arranged in a cascade, whereby liquid electrolyte reacts in a first electrochemical cell (or group of cells) before being directed into a second cell (or group of cells) where it reacts before being directed to subsequent cells. The cascade includes 2 to n stages, each stage having one or more electrochemical cells. During a charge reaction, electrolyte entering a first stage will have a lower state-of-charge than electrolyte entering the nth stage. In some embodiments, cell components and/or characteristics may be configured based on a state-of-charge of electrolytes expected at each cascade stage. Such engineered cascades provide redox flow battery systems with higher energy efficiency over a broader range of current density than prior art arrangements.

  15. Specialized Computer Systems for Environment Visualization

    Science.gov (United States)

    Al-Oraiqat, Anas M.; Bashkov, Evgeniy A.; Zori, Sergii A.

    2018-06-01

    The need for real time image generation of landscapes arises in various fields as part of tasks solved by virtual and augmented reality systems, as well as geographic information systems. Such systems provide opportunities for collecting, storing, analyzing and graphically visualizing geographic data. Algorithmic and hardware software tools for increasing the realism and efficiency of the environment visualization in 3D visualization systems are proposed. This paper discusses a modified path tracing algorithm with a two-level hierarchy of bounding volumes and finding intersections with Axis-Aligned Bounding Box. The proposed algorithm eliminates the branching and hence makes the algorithm more suitable to be implemented on the multi-threaded CPU and GPU. A modified ROAM algorithm is used to solve the qualitative visualization of reliefs' problems and landscapes. The algorithm is implemented on parallel systems—cluster and Compute Unified Device Architecture-networks. Results show that the implementation on MPI clusters is more efficient than Graphics Processing Unit/Graphics Processing Clusters and allows real-time synthesis. The organization and algorithms of the parallel GPU system for the 3D pseudo stereo image/video synthesis are proposed. With realizing possibility analysis on a parallel GPU-architecture of each stage, 3D pseudo stereo synthesis is performed. An experimental prototype of a specialized hardware-software system 3D pseudo stereo imaging and video was developed on the CPU/GPU. The experimental results show that the proposed adaptation of 3D pseudo stereo imaging to the architecture of GPU-systems is efficient. Also it accelerates the computational procedures of 3D pseudo-stereo synthesis for the anaglyph and anamorphic formats of the 3D stereo frame without performing optimization procedures. The acceleration is on average 11 and 54 times for test GPUs.

  16. Visualization and analysis of flow patterns of human carotid bifurcation by computational fluid dynamics

    International Nuclear Information System (INIS)

    Xue Yunjing; Gao Peiyi; Lin Yan

    2007-01-01

    Objective: To investigate flow patterns at carotid bifurcation in vivo by combining computational fluid dynamics (CFD)and MR angiography imaging. Methods: Seven subjects underwent contrast-enhanced MR angiography of carotid artery in Siemens 3.0 T MR. Flow patterns of the carotid artery bifurcation were calculated and visualized by combining MR vascular imaging post-processing and CFD. Results: The flow patterns of the carotid bifurcations in 7 subjects were varied with different phases of a cardiac cycle. The turbulent flow and back flow occurred at bifurcation and proximal of internal carotid artery (ICA) and external carotid artery (ECA), their occurrence and conformation were varied with different phase of a cardiac cycle. The turbulent flow and back flow faded out quickly when the blood flow to the distal of ICA and ECA. Conclusion: CFD combined with MR angiography can be utilized to visualize the cyclical change of flow patterns of carotid bifurcation with different phases of a cardiac cycle. (authors)

  17. Visualizing systems engineering data with Java

    International Nuclear Information System (INIS)

    Barter, R; Vinzant, A.

    1998-01-01

    Systems Engineers are required to deal with complex sets of data. To be useful, the data must be managed effectively, and presented in meaningful terms to a wide variety of information consumers. Two software patterns are presented as the basis for exploring the visualization of systems engineering data. The Model, View, Controller pattern defines an information management system architecture. The Entity, Relation, Attribute pattern defines the information model. MVC Views then form the basis for the user interface between the information consumer and the MVC Controller/Model combination. A Java tool set is described for exploring alternative views into the underlying complex data structures encountered in systems engineering

  18. Flow Visualization with Quantified Spatial and Temporal Errors Using Edge Maps

    KAUST Repository

    Bhatia, H.

    2012-09-01

    Robust analysis of vector fields has been established as an important tool for deriving insights from the complex systems these fields model. Traditional analysis and visualization techniques rely primarily on computing streamlines through numerical integration. The inherent numerical errors of such approaches are usually ignored, leading to inconsistencies that cause unreliable visualizations and can ultimately prevent in-depth analysis. We propose a new representation for vector fields on surfaces that replaces numerical integration through triangles with maps from the triangle boundaries to themselves. This representation, called edge maps, permits a concise description of flow behaviors and is equivalent to computing all possible streamlines at a user defined error threshold. Independent of this error streamlines computed using edge maps are guaranteed to be consistent up to floating point precision, enabling the stable extraction of features such as the topological skeleton. Furthermore, our representation explicitly stores spatial and temporal errors which we use to produce more informative visualizations. This work describes the construction of edge maps, the error quantification, and a refinement procedure to adhere to a user defined error bound. Finally, we introduce new visualizations using the additional information provided by edge maps to indicate the uncertainty involved in computing streamlines and topological structures. © 2012 IEEE.

  19. Flow Visualization with Quantified Spatial and Temporal Errors Using Edge Maps

    KAUST Repository

    Bhatia, H.; Jadhav, S.; Bremer, P.; Guoning Chen,; Levine, J. A.; Nonato, L. G.; Pascucci, V.

    2012-01-01

    Robust analysis of vector fields has been established as an important tool for deriving insights from the complex systems these fields model. Traditional analysis and visualization techniques rely primarily on computing streamlines through numerical integration. The inherent numerical errors of such approaches are usually ignored, leading to inconsistencies that cause unreliable visualizations and can ultimately prevent in-depth analysis. We propose a new representation for vector fields on surfaces that replaces numerical integration through triangles with maps from the triangle boundaries to themselves. This representation, called edge maps, permits a concise description of flow behaviors and is equivalent to computing all possible streamlines at a user defined error threshold. Independent of this error streamlines computed using edge maps are guaranteed to be consistent up to floating point precision, enabling the stable extraction of features such as the topological skeleton. Furthermore, our representation explicitly stores spatial and temporal errors which we use to produce more informative visualizations. This work describes the construction of edge maps, the error quantification, and a refinement procedure to adhere to a user defined error bound. Finally, we introduce new visualizations using the additional information provided by edge maps to indicate the uncertainty involved in computing streamlines and topological structures. © 2012 IEEE.

  20. Wearable Smart System for Visually Impaired People

    OpenAIRE

    Ali Jasim Ramadhan

    2018-01-01

    In this paper, we present a wearable smart system to help visually impaired persons (VIPs) walk by themselves through the streets, navigate in public places, and seek assistance. The main components of the system are a microcontroller board, various sensors, cellular communication and GPS modules, and a solar panel. The system employs a set of sensors to track the path and alert the user of obstacles in front of them. The user is alerted by a sound emitted through a buzzer and by vibrations o...

  1. Shaded computer graphic techniques for visualizing and interpreting analytic fluid flow models

    Science.gov (United States)

    Parke, F. I.

    1981-01-01

    Mathematical models which predict the behavior of fluid flow in different experiments are simulated using digital computers. The simulations predict values of parameters of the fluid flow (pressure, temperature and velocity vector) at many points in the fluid. Visualization of the spatial variation in the value of these parameters is important to comprehend and check the data generated, to identify the regions of interest in the flow, and for effectively communicating information about the flow to others. The state of the art imaging techniques developed in the field of three dimensional shaded computer graphics is applied to visualization of fluid flow. Use of an imaging technique known as 'SCAN' for visualizing fluid flow, is studied and the results are presented.

  2. Experimental study of natural two-phase flow circulation using a visualization technique

    International Nuclear Information System (INIS)

    Vinhas, Pedro A.M.; Su, Jian

    2013-01-01

    This paper presents an experimental study of natural two-phase flow in a circuit that simulates, on a smaller scale, a typical residual heat removal system of passive reactors APWR (Advanced Pressurized Water Reactor). The circuit was formed by a heater, a heat exchanger and piping. The experimental study was the application of a visualization technique, using a high speed camera, for measuring the size and speed of vapor bubbles generated in the heater with different power heating. The camera was positioned in the central region of the pipe connecting the heater to the heat exchanger, where there is a clear passage. The flow of images were processed and analyzed using commercial software that allowed the determination of the length and velocity of the bubbles. The results were then compared with correlations available in literature

  3. High Performance Interactive System Dynamics Visualization

    Energy Technology Data Exchange (ETDEWEB)

    Bush, Brian W [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Brunhart-Lupo, Nicholas J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Gruchalla, Kenny M [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Duckworth, Jonathan C [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-09-14

    This brochure describes a system dynamics simulation (SD) framework that supports an end-to-end analysis workflow that is optimized for deployment on ESIF facilities(Peregrine and the Insight Center). It includes (I) parallel and distributed simulation of SD models, (ii) real-time 3D visualization of running simulations, and (iii) comprehensive database-oriented persistence of simulation metadata, inputs, and outputs.

  4. High Performance Interactive System Dynamics Visualization

    Energy Technology Data Exchange (ETDEWEB)

    Bush, Brian W [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Brunhart-Lupo, Nicholas J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Gruchalla, Kenny M [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Duckworth, Jonathan C [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-09-14

    This presentation describes a system dynamics simulation (SD) framework that supports an end-to-end analysis workflow that is optimized for deployment on ESIF facilities(Peregrine and the Insight Center). It includes (I) parallel and distributed simulation of SD models, (ii) real-time 3D visualization of running simulations, and (iii) comprehensive database-oriented persistence of simulation metadata, inputs, and outputs.

  5. Flow pumping system for physiological waveforms.

    Science.gov (United States)

    Tsai, William; Savaş, Omer

    2010-02-01

    A pulsatile flow pumping system is developed to replicate flow waveforms with reasonable accuracy for experiments simulating physiological blood flows at numerous points in the body. The system divides the task of flow waveform generation between two pumps: a gear pump generates the mean component and a piston pump generates the oscillatory component. The system is driven by two programmable servo controllers. The frequency response of the system is used to characterize its operation. The system has been successfully tested in vascular flow experiments where sinusoidal, carotid, and coronary flow waveforms are replicated.

  6. An approach for the development of visual configuration systems

    DEFF Research Database (Denmark)

    Hvam, Lars; Ladeby, Klaes Rohde

    2007-01-01

    How can a visual configuration system be developed to support the specification process' in companies that manufacture customer tailored products? This article focuses on how visual configuration systems can be developed. The approach for developing visual configuration systems has been developed...... by Centre for Product Modelling (CPM) at The Technical University of Denmark. The approach is based on experiences from a visualization project in co-operation between CPM and the global provider of power protection American Power Conversion (APC). The visual configuration system was developed in 2001...... of the product in the visual configuration system....

  7. Watch the lights. A visual communication system.

    Science.gov (United States)

    Rahtz, S K

    1989-01-01

    The trend for hospitals to market their emergency care services results in a greater demand on radiology departments, states Ms. Rahtz. Radiology must provide efficient service to both departments, even when it is difficult to predict patient flow in the emergency care center. Improved communication is the key, and a light system installed at Morton Plant Hospital is one alternative for solving the problem.

  8. Visualization and Quantification of Rotor Tip Vortices in Helicopter Flows

    Science.gov (United States)

    Kao, David L.; Ahmad, Jasim U.; Holst, Terry L.

    2015-01-01

    This paper presents an automated approach for effective extraction, visualization, and quantification of vortex core radii from the Navier-Stokes simulations of a UH-60A rotor in forward flight. We adopt a scaled Q-criterion to determine vortex regions and then perform vortex core profiling in these regions to calculate vortex core radii. This method provides an efficient way of visualizing and quantifying the blade tip vortices. Moreover, the vortices radii are displayed graphically in a plane.

  9. Visualization of cross-sectional flow structure during condensation of steam in a slightly inclined horizontal tube

    Energy Technology Data Exchange (ETDEWEB)

    Puseya, Andree; Kim, H. [Kyung Hee University, Yongin (Korea, Republic of); Kwon, T. S. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    These flow characteristics called flow patterns still depend on a proper visualization technique in order to identify such local distribution. These proper distributions will have a dependence on the inclination of the tube as well, as it was demonstrated by Lips and Mayer. This work is focused on presenting an experimental investigation to visualize the cross sectional two-phase flow structure for condensation of steam in a horizontal tube and identify the liquid-gas interface using the axial-viewing technique. This innovative technique developed by Hewitt and more recently used in visualization works by Badie, permits the achievement to identify those systems in the area of interest by looking directly into the two-phase flow system during condensation of steam inside a pipe with technology such a high speed camera. An experimental work to visualize and locate the liquid-gas interface for steam condensation in horizontal tubes with slightly inclination was developed on this research The experimental results shows that the axial viewing technique works well with condensation phenomena and can be used for further developments in the field such as determination of liquid film geometry and calculation of void fraction.

  10. Radiation Counting System Software Using Visual Basic

    International Nuclear Information System (INIS)

    Nanda Nagara; Didi Gayani

    2009-01-01

    It has been created a Gamma Radiation Counting System using interface card, which paired with Personal Computer (PC) and operated by the Visual Basic program. The program was set through varied menu selections such as ”Multi Counting” , ”Counting and Record” and ”View Data”. An interface card for data acquisition was formed by using AMD9513 components as a counter and timer which can be programmed. This counting system was tested and used in waste facility in PTNBR and the result is quite good. (author)

  11. A single photon emission computed tomograph based on a limited dumber of detectors for fluid flow visualization

    International Nuclear Information System (INIS)

    Legoupil, S.

    1999-01-01

    We present in this work a method for fluid flow visualization in a system using radioactive tracers. The method is based on single photon emission computed tomography techniques, applied to a limited number of discrete detectors. We propose in this work a method for the estimation of the transport matrix of photons, associated to the acquisition system. This method is based on the modelization of profiles acquired for a set of point sources located in the imaged volume. Monte Carlo simulations allow to separate scattered photons from those directly collected by the system. The influence of the energy tracer is exposed. The reconstruction method is based on the maximum likelihood - expectation maximization algorithm. An experimental device, based on 36 detectors was realised for the visualization of water circulation in a vessel. A video monitoring allows to visualize the dye water tracer. Dye and radioactive tracers are injected simultaneously in a water flow circulating in the vessel. Reconstructed and video images are compared. Quantitative and qualitative analysis show that fluid flow visualization is feasible with a limited number of detectors. This method can be applied for system involving circulations of fluids. (author)

  12. Visual study of air--water mixtures flowing inside serpentine tubes

    International Nuclear Information System (INIS)

    Farukhi, M.N.; Parker, J.D.

    1974-01-01

    Hydrodynamic behavior of air-water mixtures flowing inside serpentine tubes, with bends in the vertical plane, was investigated. Flow visualization was accomplished by injecting dye into the liquid phase and recording the events on color slides and color movies. For certain combinations of gas and liquid flow rates, in the annular type flow regime, ''film inversion'' was observed in the bend as well as in the straight section immediately downstream of the bend. A new flow regime map particularly applicable to two phase flow inside serpentine tubes is presented. (U.S.)

  13. Visual assistance system for cyclotron operation

    International Nuclear Information System (INIS)

    Okamura, Tetsuya; Tachikawa, Toshiki; Murakami, Tohru.

    1994-01-01

    A computer-based operation system for a cyclotron which assists operators has been developed. It is the operation assistance system depending on visual sense to indicate beam parameters to operators. First, the mental model of operators at the time of beam adjustment was analyzed, and it was presumed to be composed of five partial mental models, that is, beam behavior model, feasible setting region model, parameter sensitivity model, parameter interrelation model and status map model. Next, three visual interfaces were developed. Beam trajectory is rapidly calculated and graphically displayed whenever operators change parameters. Feasible setting regions (FSR) for parameters that satisfy the beam acceptance criteria of a cyclotron are indicated. The distribution of beam current values which are the quantity for evaluating adjustment is indicated as search history. Finally, for evaluating the system effectiveness, the search time required to reach the optimum conditions was measured. In addition, the system usability was evaluated by written questionnaires. The result of experiment showed the reduction of search time by about 65%. The written questionnaires survey showed the operators highly evaluate system usability. (K.I.)

  14. Measurement and flow visualization research of thermal hydraulic characteristics for the SFR reactor Vessel

    International Nuclear Information System (INIS)

    Cha, J. E.; Kim, S. O.; Choi, H. L.; Kim, H. B.; Kim, H. W.; Lee, S. H.

    2012-01-01

    In this report, the thermal hydraulic and flow visualization experiment was described for the KALIMER-600 water-scaled model. In order to investigate a thermal hydraulic characteristics for the SFR KALIMER-600, which has been conceptually designed in the KAERI, a water-scaled 1/10 reactor vessel model was designed and prepared through the scaling analysis during three-years research. In this research, SFR Photos system, which has inherently very complicated the internal structures, was fabricated with a transparent vessel. It was shown that a serious of thermal hydraulic test was conducted within a short period if modeled with water than sodium. Natural circulation test was successfully performed with the modeled heater assembly and heat exchanger system coupled with cooling system. The water-scaled RSV experimental facility made in this research could be used to study the USA development for the future SFR system and utilized to analyze the flow characteristics before changing a main internal part of Photos system. It could also be used to test a pool-inspection study and a sensor selection study before large scale sodium experiment. The PCV system prepared in this research could be utilized to test other TSH experiment and temperature field measurement

  15. Plasticity in the Drosophila larval visual System

    Directory of Open Access Journals (Sweden)

    Abud J Farca-Luna

    2013-07-01

    Full Text Available The remarkable ability of the nervous system to modify its structure and function is mostly experience and activity modulated. The molecular basis of neuronal plasticity has been studied in higher behavioral processes, such as learning and memory formation. However, neuronal plasticity is not restricted to higher brain functions, but may provide a basic feature of adaptation of all neural circuits. The fruit fly Drosophila melanogaster provides a powerful genetic model to gain insight into the molecular basis of nervous system development and function. The nervous system of the larvae is again a magnitude simpler than its adult counter part, allowing the genetic assessment of a number of individual genetically identifiable neurons. We review here recent progress on the genetic basis of neuronal plasticity in developing and functioning neural circuits focusing on the simple visual system of the Drosophila larva.

  16. ATTENTIONAL NETWORKS AND SELECTIVE VISUAL SYSTEM

    Directory of Open Access Journals (Sweden)

    ALEJANDRO CASTILLO MORENO

    2006-05-01

    Full Text Available In this paper we checked the principal researches and theories to explain the attention system functioning.We are going to start reviewing along time about the concept of attention, from filter theories andresources distributor theories, to the current theories in which attention is conceived as a control system.From this last point of view, we will emphasize on the attentional networks theory of Posner, thatproposes different systems to explain diverse aspects of attention, but they are related to each other. Atlast in this paper, we will mention experimental results that have been important to characterize theselective attentional mechanisms of the human visual system, using the attentional spotlight model forthis aim.

  17. VISUALIZATION METHODS OF VORTICAL FLOWS IN COMPUTATIONAL FLUID DYNAMICS AND THEIR APPLICATIONS

    Directory of Open Access Journals (Sweden)

    K. N. Volkov

    2014-05-01

    Full Text Available The paper deals with conceptions and methods for visual representation of research numerical results in the problems of fluid mechanics and gas. The three-dimensional nature of unsteady flow being simulated creates significant difficulties for the visual representation of results. It complicates control and understanding of numerical data, and exchange and processing of obtained information about the flow field. Approaches to vortical flows visualization with the usage of gradients of primary and secondary scalar and vector fields are discussed. An overview of visualization techniques for vortical flows using different definitions of the vortex and its identification criteria is given. Visualization examples for some solutions of gas dynamics problems related to calculations of jets and cavity flows are presented. Ideas of the vortical structure of the free non-isothermal jet and the formation of coherent vortex structures in the mixing layer are developed. Analysis of formation patterns for spatial flows inside large-scale vortical structures within the enclosed space of the cubic lid-driven cavity is performed. The singular points of the vortex flow in a cubic lid-driven cavity are found based on the results of numerical simulation; their type and location are identified depending on the Reynolds number. Calculations are performed with fine meshes and modern approaches to the simulation of vortical flows (direct numerical simulation and large-eddy simulation. Paradigm of graphical programming and COVISE virtual environment are used for the visual representation of computational results. Application that implements the visualization of the problem is represented as a network which links are modules and each of them is designed to solve a case-specific problem. Interaction between modules is carried out by the input and output ports (data receipt and data transfer giving the possibility to use various input and output devices.

  18. Fluorescent multiplex cell flow systems and methods

    KAUST Repository

    Merzaban, Jasmeen

    2017-06-01

    Systems and methods are provided for simultaneously assaying cell adhesion or cell rolling for multiple cell specimens. One embodiment provides a system for assaying adhesion or cell rolling of multiple cell specimens that includes a confocal imaging system containing a parallel plate flow chamber, a pump in fluid communication with the parallel plate flow chamber via a flow chamber inlet line and a cell suspension in fluid communication with the parallel plate flow chamber via a flow chamber outlet line. The system also includes a laser scanning system in electronic communication with the confocal imaging system, and a computer in communication with the confocal imaging system and laser scanning system. In certain embodiments, the laser scanning system emits multiple electromagnetic wavelengths simultaneously it cause multiple fluorescent labels having different excitation wavelength maximums to fluoresce. The system can simultaneously capture real-time fluorescence images from at least seven cell specimens in the parallel plate flow chamber.

  19. Visualizing and simulating flow conditions in concrete form filling using pigments

    DEFF Research Database (Denmark)

    Jacobsen, Stefan; Cepuritis, Rolands; Peng, Ya

    2013-01-01

    Flow variation at surfaces and reinforcement during form filling was visualized with grey and black SCC. The border between grey and black (pigmented) SCC was captured as frozen images on hardened sawn- and formwork surfaces in a flow box experiment. Maximum velocity occurred at the centre of the...

  20. Visualization and quantitative analysis of the CSF pulsatile flow with cine MR phase imaging

    International Nuclear Information System (INIS)

    Katayama, Shinji; Itoh, Takahiko; Kinugasa, Kazushi; Asari, Shoji; Nishimoto, Akira; Tsuchida, Shohei; Ono, Atsushi; Ikezaki, Yoshikazu; Yoshitome, Eiji.

    1991-01-01

    The visualization and the quantitative analysis of the CSF pulsatile flow were performed on ten healthy volunteers with cine MR phase imaging, a combination of the phase-contrast technique and the cardiac-gating technique. The velocities appropriate for the visualization and the quantitative analysis of the CSF pulsatile flow were from 6.0 cm/sec to 15.0 cm/sec. The applicability of this method for the quantitative analysis was proven with a steady-flow phantom. Phase images clearly demonstrated a to-and-fro motion of the CSF flow in the anterior subarachnoid space and in the posterior subarachnoid space. The flow pattern of CSF on healthy volunteers depends on the cardiac cycle. In the anterior subarachnoid space, the cephalic CSF flow continued until a 70-msec delay after the R-wave of the ECG and then reversed to caudal. At 130-190 msec, the caudal CSF flow reached its maximum velocity; thereafter it reversed again to cephalic. The same turn appeared following the phase, but then the amplitude decreased. The cephalic peaked at 370-430 msec, while the caudal peaked at 490-550 msec. The flow pattern of the CSF flow in the posterior subarachnoid space was almost identical to that in the anterior subarachnoid space. Cine MR phase imaging is thus useful for the visualization and the quantitative analysis of the CSF pulsative flow. (author)

  1. Flow Visualization in Evaporating Liquid Drops and Measurement of Dynamic Contact Angles and Spreading Rate

    Science.gov (United States)

    Zhang, Neng-Li; Chao, David F.

    2001-01-01

    A new hybrid optical system, consisting of reflection-refracted shadowgraphy and top-view photography, is used to visualize flow phenomena and simultaneously measure the spreading and instant dynamic contact angle in a volatile-liquid drop on a nontransparent substrate. Thermocapillary convection in the drop, induced by evaporation, and the drop real-time profile data are synchronously recorded by video recording systems. Experimental results obtained from this unique technique clearly reveal that thermocapillary convection strongly affects the spreading process and the characteristics of dynamic contact angle of the drop. Comprehensive information of a sessile drop, including the local contact angle along the periphery, the instability of the three-phase contact line, and the deformation of the drop shape is obtained and analyzed.

  2. Wearable Smart System for Visually Impaired People

    Directory of Open Access Journals (Sweden)

    Ali Jasim Ramadhan

    2018-03-01

    Full Text Available In this paper, we present a wearable smart system to help visually impaired persons (VIPs walk by themselves through the streets, navigate in public places, and seek assistance. The main components of the system are a microcontroller board, various sensors, cellular communication and GPS modules, and a solar panel. The system employs a set of sensors to track the path and alert the user of obstacles in front of them. The user is alerted by a sound emitted through a buzzer and by vibrations on the wrist, which is helpful when the user has hearing loss or is in a noisy environment. In addition, the system alerts people in the surroundings when the user stumbles over or requires assistance, and the alert, along with the system location, is sent as a phone message to registered mobile phones of family members and caregivers. In addition, the registered phones can be used to retrieve the system location whenever required and activate real-time tracking of the VIP. We tested the system prototype and verified its functionality and effectiveness. The proposed system has more features than other similar systems. We expect it to be a useful tool to improve the quality of life of VIPs.

  3. Wearable Smart System for Visually Impaired People.

    Science.gov (United States)

    Ramadhan, Ali Jasim

    2018-03-13

    In this paper, we present a wearable smart system to help visually impaired persons (VIPs) walk by themselves through the streets, navigate in public places, and seek assistance. The main components of the system are a microcontroller board, various sensors, cellular communication and GPS modules, and a solar panel. The system employs a set of sensors to track the path and alert the user of obstacles in front of them. The user is alerted by a sound emitted through a buzzer and by vibrations on the wrist, which is helpful when the user has hearing loss or is in a noisy environment. In addition, the system alerts people in the surroundings when the user stumbles over or requires assistance, and the alert, along with the system location, is sent as a phone message to registered mobile phones of family members and caregivers. In addition, the registered phones can be used to retrieve the system location whenever required and activate real-time tracking of the VIP. We tested the system prototype and verified its functionality and effectiveness. The proposed system has more features than other similar systems. We expect it to be a useful tool to improve the quality of life of VIPs.

  4. A novel visual pipework inspection system

    Science.gov (United States)

    Summan, Rahul; Jackson, William; Dobie, Gordon; MacLeod, Charles; Mineo, Carmelo; West, Graeme; Offin, Douglas; Bolton, Gary; Marshall, Stephen; Lille, Alexandre

    2018-04-01

    The interior visual inspection of pipelines in the nuclear industry is a safety critical activity conducted during outages to ensure the continued safe and reliable operation of plant. Typically, the video output by a manually deployed probe is viewed by an operator looking to identify and localize surface defects such as corrosion, erosion and pitting. However, it is very challenging to estimate the nature and extent of defects by viewing a large structure through a relatively small field of view. This work describes a new visual inspection system employing photogrammetry using a fisheye camera and a structured light system to map the internal geometry of pipelines by generating a photorealistic, geometrically accurate surface model. The error of the system output was evaluated through comparison to a ground truth laser scan (ATOS GOM Triple Scan) of a nuclear grade split pipe sample (stainless steel 304L, 80mm internal diameter) containing defects representative of the application - the error was found to be submillimeter across the sample.

  5. Visualization and PIV measurement of unsteady flow around a darrieus wind turbine in dynamic stall

    Energy Technology Data Exchange (ETDEWEB)

    Shibuya, Satoshi; Fujisawa, Nobuyuki; Takano, Tsuyoshi [Dept. of Mechanical and Production Engineering, Niigata Univ., Niigata (Japan)

    1999-07-01

    Flow around a Darrieus wind turbine in dynamic stall is studied by flow visualization and PIV (particle image velocimeter) measurement in a rotating frame of reference, which allows the successive observation of the dynamic stall over the blade. The qualitative features of the flow field in dynamic stall observed by the flow visualization, such as the formation and shedding of the stall vortices, are quantitatively reproduced in the instantaneous velocity distributions near the blade by using PIV. These results indicate that two pairs of stall vortices are generated from the blade during one rotation of the blade and that the size and the generating blade angle of the stall vortices are enlarged as the tip-speed ratio decreases. These stall vortices are produced by the in-flow motion from the outer surface to the inner surface through the trailing edge of the blade and the flow separation over the inner surface of the blade. (author)

  6. Visualize This The FlowingData Guide to Design, Visualization, and Statistics

    CERN Document Server

    Yau, Nathan

    2011-01-01

    Practical data design tips from a data visualization expert of the modern age Data doesn?t decrease; it is ever-increasing and can be overwhelming to organize in a way that makes sense to its intended audience. Wouldn?t it be wonderful if we could actually visualize data in such a way that we could maximize its potential and tell a story in a clear, concise manner? Thanks to the creative genius of Nathan Yau, we can. With this full-color book, data visualization guru and author Nathan Yau uses step-by-step tutorials to show you how to visualize and tell stories with data. He explains how to ga

  7. Flow visualization with laser light-sheet techniques in automotive research

    International Nuclear Information System (INIS)

    Hentschel, W.; Stoffregen, B.

    1987-01-01

    This paper presents different set-ups for the visualization of flow fields in automotive research i.e. aerodynamics and i.c. engines, with the help of laser light-sheet techniques. Special efforts are made to apply these techniques to temporarily resolved studies of unsteady flows and for the quantitative analysis of a flow field in two dimensions in a full plane instantaneously. Several examples taken from current work are presented

  8. Relationship among visual field, blood flow, and neural structure measurements in glaucoma.

    Science.gov (United States)

    Hwang, John C; Konduru, Ranjith; Zhang, Xinbo; Tan, Ou; Francis, Brian A; Varma, Rohit; Sehi, Mitra; Greenfield, David S; Sadda, Srinivas R; Huang, David

    2012-05-17

    To determine the relationship among visual field, neural structural, and blood flow measurements in glaucoma. Case-control study. Forty-seven eyes of 42 patients with perimetric glaucoma were age-matched with 27 normal eyes of 27 patients. All patients underwent Doppler Fourier-domain optical coherence tomography to measure retinal blood flow and standard glaucoma evaluation with visual field testing and quantitative structural imaging. Linear regression analysis was performed to analyze the relationship among visual field, blood flow, and structure, after all variables were converted to logarithmic decibel scale. Retinal blood flow was reduced in glaucoma eyes compared to normal eyes (P flow and structural loss of rim area and retinal nerve fiber layer (RNFL). There was no correlation or paradoxical correlation between blood flow and structure. Multivariate regression analysis revealed that reduced blood flow and structural loss are independent predictors of visual field loss. Each dB decrease in blood flow was associated with at least 1.62 dB loss in mean deviation (P ≤ 0.001), whereas each dB decrease in rim area and RNFL was associated with 1.15 dB and 2.56 dB loss in mean deviation, respectively (P ≤ 0.03). There is a close link between reduced retinal blood flow and visual field loss in glaucoma that is largely independent of structural loss. Further studies are needed to elucidate the causes of the vascular dysfunction and potential avenues for therapeutic intervention. Blood flow measurement may be useful as an independent assessment of glaucoma severity.

  9. Intuitive Visualization of Transient Flow: Towards a Full 3D Tool

    Science.gov (United States)

    Michel, Isabel; Schröder, Simon; Seidel, Torsten; König, Christoph

    2015-04-01

    Visualization of geoscientific data is a challenging task especially when targeting a non-professional audience. In particular, the graphical presentation of transient vector data can be a significant problem. With STRING Fraunhofer ITWM (Kaiserslautern, Germany) in collaboration with delta h Ingenieurgesellschaft mbH (Witten, Germany) developed a commercial software for intuitive 2D visualization of 3D flow problems. Through the intuitive character of the visualization experts can more easily transport their findings to non-professional audiences. In STRING pathlets moving with the flow provide an intuition of velocity and direction of both steady-state and transient flow fields. The visualization concept is based on the Lagrangian view of the flow which means that the pathlets' movement is along the direction given by pathlines. In order to capture every detail of the flow an advanced method for intelligent, time-dependent seeding of the pathlets is implemented based on ideas of the Finite Pointset Method (FPM) originally conceived at and continuously developed by Fraunhofer ITWM. Furthermore, by the same method pathlets are removed during the visualization to avoid visual cluttering. Additional scalar flow attributes, for example concentration or potential, can either be mapped directly to the pathlets or displayed in the background of the pathlets on the 2D visualization plane. The extensive capabilities of STRING are demonstrated with the help of different applications in groundwater modeling. We will discuss the strengths and current restrictions of STRING which have surfaced during daily use of the software, for example by delta h. Although the software focusses on the graphical presentation of flow data for non-professional audiences its intuitive visualization has also proven useful to experts when investigating details of flow fields. Due to the popular reception of STRING and its limitation to 2D, the need arises for the extension to a full 3D tool

  10. Visualization of Concrete Slump Flow Using the Kinect Sensor.

    Science.gov (United States)

    Kim, Jung-Hoon; Park, Minbeom

    2018-03-03

    Workability is regarded as one of the important parameters of high-performance concrete and monitoring it is essential in concrete quality management at construction sites. The conventional workability test methods are basically based on length and time measured by a ruler and a stopwatch and, as such, inevitably involves human error. In this paper, we propose a 4D slump test method based on digital measurement and data processing as a novel concrete workability test. After acquiring the dynamically changing 3D surface of fresh concrete using a 3D depth sensor during the slump flow test, the stream images are processed with the proposed 4D slump processing algorithm and the results are compressed into a single 4D slump image. This image basically represents the dynamically spreading cross-section of fresh concrete along the time axis. From the 4D slump image, it is possible to determine the slump flow diameter, slump flow time, and slump height at any location simultaneously. The proposed 4D slump test will be able to activate research related to concrete flow simulation and concrete rheology by providing spatiotemporal measurement data of concrete flow.

  11. Electrophysiological measurement of information flow during visual search

    OpenAIRE

    Cosman, Joshua D.; Arita, Jason T.; Ianni, Julianna D.; Woodman, Geoffrey F.

    2015-01-01

    The temporal relationship between different stages of cognitive processing is long-debated. This debate is ongoing, primarily because it is often difficult to measure the time course of multiple cognitive processes simultaneously. We employed a manipulation that allowed us to isolate ERP components related to perceptual processing, working memory, and response preparation, and then examined the temporal relationship between these components while observers performed a visual search task. We f...

  12. Measuring method of liquid flow behavior using visualization

    International Nuclear Information System (INIS)

    Serizawa, Akimi; Kamei, Takashi; Takahashi, Osamu; Kawara, Zensaku

    1994-01-01

    It is important for the safety of nuclear reactor to understand the behavior of gas-liquid two-phase flow. For that analysis, we have to understand its time and spatial dependence. But most of the measuring methods applied to two-phase flow experiments are not enough for this purpose, because they consider the time averaged value, and they are put on the local position in test sections. Standing on such a point of view, we have been developing a measuring method using fluorescence. And from those pictures gotten by video camera, after processed by computer, we measure liquid film thickness. (author)

  13. Flow visualization and relative permeability measurements in rough-walled fractures

    International Nuclear Information System (INIS)

    Persoff, P.; Pruess, K.

    1993-01-01

    Two-phase (gas-liquid) flow experiments were done in a natural rock fracture and transparent replicas of natural fractures. Liquid was injected at constant volume flow rate, and gas was injected at either constant mass flow rate or constant pressure. When gas was injected at constant mass flow rate, the gas inlet pressure, and inlet and outlet capillary pressures, generally did not reach steady state but cycled irregularly. Flow visualization showed that this cycling was due to repeated blocking and unblocking of gas flow paths by liquid. Relative permeabilities calculated from flow rate and pressure data show that the sum of the relative permeabilities of the two phases is much less than 1, indicating that each phase interferes strongly with the flow of the other. Comparison of the relative permeability curves with typical curves for porous media (Corey curves) show that the phase interference is stronger in fractures than in typical porous media

  14. Beyond the arrow plot : new methods for flow visualization

    NARCIS (Netherlands)

    Wijk, van J.J.

    1999-01-01

    Within the realm of CFD-based flow analysis, the presentation of data is a vital issue. Researchers and developers need to gain insight, and non-technical managers and commercial staff have a critical need to understand the true ramifications of the data. Unfortunately, current methods for

  15. Flow and transport in hierarchically fractured systems

    International Nuclear Information System (INIS)

    Karasaki, K.

    1993-01-01

    Preliminary results indicate that flow in the saturated zone at Yucca Mountain is controlled by fractures. A current conceptual model assumes that the flow in the fracture system can be approximately by a three-dimensionally interconnected network of linear conduits. The overall flow system of rocks at Yucca Mountain is considered to consist of hierarchically structured heterogeneous fracture systems of multiple scales. A case study suggests that it is more appropriate to use the flow parameters of the large fracture system for predicting the first arrival time, rather than using the bulk average parameters of the total system

  16. Flow visualization study of post critical heat flux region for inverted bubbly, slug and annular flow regimes

    International Nuclear Information System (INIS)

    Denten, J.G.; Ishii, M.

    1988-11-01

    A visual study of film boiling using still photographic and high- speed motion picture methods was carried out in order to analyze the post-CHF hydrodynamics for steady-state inlet pre-CHF two-phase flow regimes. Pre-CHF two-phase flow regimes were established by introducing Freon 113 liquid and nitrogen gas into a jet core injection nozzle. An idealized, post-CHF two-phase core initial flow geometry (cylindrical multiphase jet core surrounded by a coaxial annulus of gas) was established at the nozzle exit by introducing nitrogen gas into the annular gap between the jet nozzle two-phase effluent and the heated test section inlet. For the present study three basic post-CHF flow regimes have been observed: the rough wavy regime (inverted annular flow preliminary break down), the agitated regime (transition between inverted annular and dispersed droplet flow), and the dispersed ligament/droplet regime. For pre-CHF bubbly flow in the jet nozzle, the post-CHF flow (beginning from jet nozzle exit/heated test section inlet) consists of the rough wavy regime, followed by the agitated and then the dispersed ligament/droplet regime. In the same way, for pre-CHF slug flow in the jet core, the post-CHF flow is comprised of the agitated regime at the nozzle exit, followed by the dispersed regime. Pre-CHF annular jet core flow results in a small, depleted post-CHF agitated flow regime at the nozzle exit, immediately followed by the dispersed ligament/droplet regime. Observed post dryout hydrodynamic behavior is reported, with particular attention given to the transition flow pattern between inverted annular and dispersed droplet flow. 43 refs., 20 figs., 5 tabs

  17. A flow visualization study of spore release using a wind tunnel-mounted laser light sheet

    International Nuclear Information System (INIS)

    Davis, J.M.; Eisner, A.D.; Wiener, R.W.; Main, C.E.

    1997-01-01

    A phase Doppler anemometry system in combination with a laser light sheet was used in a low-speed recirculating wind tunnel to examine the flow field around an individual leaf. Turbulence similar to that encountered near the surface of the earth in a neutral stability boundary layer was generated using a grid at the upwind end of the wind tunnel test section. Individual healthy and diseased plant leaves were introduced into the tunnel with the leaf tip pointing downwind. The Mie-scattered radiation from the spores departing the diseased leaf was captured on videotape. Image processing software was used to enhance the visual quality of the individual frames from the videotape and to make spore velocity calculations. Three main vortex regions around the leaf were identified. The importance of these regions to the separation of the spores from the leaf surface and their subsequent downwind movement was analyzed

  18. Public health nurse perceptions of Omaha System data visualization.

    Science.gov (United States)

    Lee, Seonah; Kim, Era; Monsen, Karen A

    2015-10-01

    Electronic health records (EHRs) provide many benefits related to the storage, deployment, and retrieval of large amounts of patient data. However, EHRs have not fully met the need to reuse data for decision making on follow-up care plans. Visualization offers new ways to present health data, especially in EHRs. Well-designed data visualization allows clinicians to communicate information efficiently and effectively, contributing to improved interpretation of clinical data and better patient care monitoring and decision making. Public health nurse (PHN) perceptions of Omaha System data visualization prototypes for use in EHRs have not been evaluated. To visualize PHN-generated Omaha System data and assess PHN perceptions regarding the visual validity, helpfulness, usefulness, and importance of the visualizations, including interactive functionality. Time-oriented visualization for problems and outcomes and Matrix visualization for problems and interventions were developed using PHN-generated Omaha System data to help PHNs consume data and plan care at the point of care. Eleven PHNs evaluated prototype visualizations. Overall PHNs response to visualizations was positive, and feedback for improvement was provided. This study demonstrated the potential for using visualization techniques within EHRs to summarize Omaha System patient data for clinicians. Further research is needed to improve and refine these visualizations and assess the potential to incorporate visualizations within clinical EHRs. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  19. Visualizing Dataflow Graphs of Deep Learning Models in TensorFlow.

    Science.gov (United States)

    Wongsuphasawat, Kanit; Smilkov, Daniel; Wexler, James; Wilson, Jimbo; Mane, Dandelion; Fritz, Doug; Krishnan, Dilip; Viegas, Fernanda B; Wattenberg, Martin

    2018-01-01

    We present a design study of the TensorFlow Graph Visualizer, part of the TensorFlow machine intelligence platform. This tool helps users understand complex machine learning architectures by visualizing their underlying dataflow graphs. The tool works by applying a series of graph transformations that enable standard layout techniques to produce a legible interactive diagram. To declutter the graph, we decouple non-critical nodes from the layout. To provide an overview, we build a clustered graph using the hierarchical structure annotated in the source code. To support exploration of nested structure on demand, we perform edge bundling to enable stable and responsive cluster expansion. Finally, we detect and highlight repeated structures to emphasize a model's modular composition. To demonstrate the utility of the visualizer, we describe example usage scenarios and report user feedback. Overall, users find the visualizer useful for understanding, debugging, and sharing the structures of their models.

  20. Visual software system for memory interleaving simulation

    Directory of Open Access Journals (Sweden)

    Milenković Katarina

    2017-01-01

    Full Text Available This paper describes the visual software system for memory interleaving simulation (VSMIS, implemented for the purpose of the course Computer Architecture and Organization 1, at the School of Electrical Engineering, University of Belgrade. The simulator enables students to expand their knowledge through practical work in the laboratory, as well as through independent work at home. VSMIS gives users the possibility to initialize parts of the system and to control simulation steps. The user has the ability to monitor simulation through graphical representation. It is possible to navigate through the entire hierarchy of the system using simple navigation. During the simulation the user can observe and set the values of the memory location. At any time, the user can reset the simulation of the system and observe it for different memory states; in addition, it is possible to save the current state of the simulation and continue with the execution of the simulation later. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. III44009

  1. Fuel visual inspection system of the RTMIII

    International Nuclear Information System (INIS)

    Delfin L, A.; Castaneda J, G.; Mazon R, R.; Aguilar H, F.

    2007-01-01

    The International Atomic Energy Agency (IAEA) through the RLA/04/18 project, Management of Irradiated Fuel in Research Reactors, it recommended among other that the participant countries (Brazil, Argentina, Chile, Peru and Mexico), develop tools to assure the integrity of the nuclear fuels used in the research reactors. The TRIGA Mark lll reactor (RTMIII) of the ININ, designed and built a system of visual inspection, that it uses a high radiation camera and image digitalisation. The project considers safety conditions of the personnel that carried out the activities of visual inspection, for that which the tool dives in the pool of the RTMIII, being held by an end in the superior part of the aluminium liner of the Reactor like it is shown in the plane No. 1. The primordial unit of the system is the visual equipment that corresponds to a camera of the Hydro-Technologie (HYTEC) VSLT 410N mark, designed to work in atmospheres under the water and/or in places of high risk. The camera has an unit of motorized orientation of stainless steel that can be rotated unboundedly in both senses, with variable speed by means of a control lever from the control unit. Together to this orientation unit is found the camera head, the one which is contained in an unit of motorized inclination of stainless steel that can be rotated azimuthally up to 370 degrees in both senses. The operation conditions of the camera are the following ones, temperature: 0 to 50 C, dose speed: ≤ 50 rad/h, operation depth: ≤ 30 mts, humidity (control unit): ≤ 80%. From the control unit it is derived an external device plug-n-play TV-Usb Aver Media marks whose function is to decode the video signal sent by the control unit and to transmit it to the computer where the image is captured in picture or video that is analyzed later on with any software ad hoc, that in our case we use the Quantikov Image Analyzer program for Windows 98 of the Dr. Lucio C. M. Pinto from Brazil who participates in the RLA/04

  2. Inversion prepared coronary MR angiography: direct visualization of coronary blood flow

    International Nuclear Information System (INIS)

    Katoh, M.; Spuentrup, E.; Buecker, A.; Guenther, R.W.; Stuber, M.; Manning, W.J.; Botnar, R.M.

    2005-01-01

    Purpose: visualization of coronary blood flow by means of a slice-selective inversion pre-pulse in concert with bright-blood coronary MRA. Materials and methods: coronary magnetic resonance angiography (MRA) of the right coronary artery (RCA) was performed in eight healthy adult subjects on a 1.5 Tesla MR system (Gyroscan ACS-NT, Philips Medical Systems, Best, NL) using a free-breathing navigator-gated and cardiac-triggered 3D steady-state free-precession (SSFP) sequence with radial k-space sampling. Imaging was performed with and without a slice-selective inversion pre-pulse, which was positioned along the main axis of the coronary artery but perpendicular to the imaging volume. Objective image quality parameters such as SNR, CNR, maximal visible vessel length, and vessel border definition were analyzed. Results: in contrast to conventional bright-blood 3D coronary MRA, the selective inversion pre-pulse provided a direct measure of coronary blood flow. In addition, CNR between the RCA and right ventricular blood pool was increased and the vessels had a tendency towards better delineation. Blood SNR and CNR between right coronary blood and epicardial fat were comparable in both sequences. (orig.)

  3. Three-dimensional visualization of myocardial motion and blood flow with cine-MR images

    International Nuclear Information System (INIS)

    Oshiro, Osamu; Matani, Ayumu; Chihara, Kunihiro; Mikami, Taisei; Kitabatake, Akira.

    1997-01-01

    This paper describes a three-dimensional (3D) reconstruction and presentation method to visualize myocardial motion and blood flow in a heart using cine-MR (magnetic resonance) images. Firstly, the region of myocardium and blood were segmented with certain threshold gray values. Secondly, some slices were interpolated linearly to reconstruct a 3D static image. Finally, a 3D dynamic image was presented with displaying the 3D static images sequentially. The experimental results indicate that this method enables to visualize not only normal but also abnormal blood flow in cine-mode. (author)

  4. Lessons from wet gas flow metering systems using differential measurements devices: Testing and flow modelling results

    Energy Technology Data Exchange (ETDEWEB)

    Cazin, J.; Couput, J.P.; Dudezert, C. et al

    2005-07-01

    A significant number of wet gas meters used for high GVF and very high GVF are based on differential pressure measurements. Recent high pressure tests performed on a variety of different DP devices on different flow loops are presented. Application of existing correlations is discussed for several DP devices including Venturi meters. For Venturi meters, deviations vary from 9% when using the Murdock correlation to less than 3 % with physical based models. The use of DP system in a large domain of conditions (Water Liquid Ratio) especially for liquid estimation will require information on the WLR This obviously raises the question of the gas and liquid flow metering accuracy in wet gas meters and highlight needs to understand AP systems behaviour in wet gas flows (annular / mist / annular mist). As an example, experimental results obtained on the influence of liquid film characteristics on a Venturi meter are presented. Visualizations of the film upstream and inside the Venturi meter are shown. They are completed by film characterization. The AP measurements indicate that for a same Lockhart Martinelli parameter, the characteristics of the two phase flow have a major influence on the correlation coefficient. A 1D model is defined and the results are compared with the experiments. These results indicate that the flow regime influences the AP measurements and that a better modelling of the flow phenomena is needed even for allocation purposes. Based on that, lessons and way forward in wet gas metering systems improvement for allocation and well metering are discussed and proposed. (author) (tk)

  5. Calculation of quantities of interest in high energy physics using visual basic 3.0. The Flow Tensor Program

    International Nuclear Information System (INIS)

    Besliu, C.; Jipa, A.; Zaharia, R.

    1995-01-01

    The Flow Tensor is an important physical quantity in High Energy Physics. The program used for the calculation of the Flow Tensor has been a complex menu-driven application, to allow the selection of various triggers for the studied reaction, of the number of traces in each studied event, of the momentum cut values for the resulting particles of fragments in each event, etc. We realised all that requests using a very modern and powerful tool: Visual Basic 3.0. This programming system allows the realisation of Windows-like programs and has numerous facilities: OLE (Object Linking and Embedding), the possibility to create professional graphics, to work with databases, to create and compile Windows-like help files. All these advantages make the effort to learn Visual Basic 3.0 worthwhile. (author)

  6. Flow Sharing Systems for Mobile Applications

    DEFF Research Database (Denmark)

    Andersen, T. O.; Hansen, M. R.; Conrad, Finn

    2002-01-01

    This contribution reports about some analytical and simulation/experimental studies carried out on different flow control systems for mobile applications with respect to their ability to do flow sharing. All systems have two parallel actuators and are considered regarding functionality...

  7. Beam-modulation methods in quantitative and flow-visualization holographic interferometry

    Science.gov (United States)

    Decker, Arthur J.

    1986-01-01

    Heterodyne holographic interferometry and time-average holography with a frequency shifted reference beam are discussed. Both methods will be used for the measurement and visualization of internal transonic flows where the target facility is a flutter cascade. The background and experimental requirements for both methods are reviewed. Measurements using heterodyne holographic interferometry are presented. The performance of the laser required for time-average holography of time-varying transonic flows is discussed.

  8. Beam-modulation methods in quantitative and flow visualization holographic interferometry

    Science.gov (United States)

    Decker, A.

    1986-01-01

    This report discusses heterodyne holographic interferometry and time-average holography with a frequency shifted reference beam. Both methods will be used for the measurement and visualization of internal transonic flows, where the target facility is a flutter cascade. The background and experimental requirements for both methods are reviewed. Measurements using heterodyne holographic interferometry are presented. The performance of the laser required for time-average holography of time-varying transonic flows is discussed.

  9. Improved dynamic CT angiography visualization by flow territory masking

    Directory of Open Access Journals (Sweden)

    Søren Christensen

    2015-01-01

    Full Text Available Backgound and Purpose: Computerized tomography (CT perfusion (or CTP source images from CT scanners with small detector widths can be used to create a dynamic CT angiogram (CTA similar to digital subtraction angiography (DSA. Because CTP studies use a single intravenous injection, all arterial territories enhance simultaneously, and individual arterial territories [i.e., anterior cerebral artery (ACA, middle cerebral artery (MCA, and posterior cerebral artery (PCA] cannot be delineated. This limits the ability to assess collateral flow patterns on dynamic CTAs. The aim of this study was to devise and test a postprocessing method to selectively color-label the major arterial territories on dynamic CTA. Materials and Methods: We identified 22 acute-stroke patients who underwent CTP on a 320-slice CT scanner within 6 h from symptom onset. For each case, two investigators independently generated an arterial territory map from CTP bolus arrival maps using a semiautomated method. The volumes of the arterial territories were calculated for each map and the average relative difference between these volumes was calculated for each case as a measure of interrater agreement. Arterial territory maps were superimposed on the dynamic CTA to create a vessel-selective dynamic CTA with color-coding of the main arterial territories. Two experts rated the arterial territory maps and the color-coded CTAs for consistency with expected arterial territories on a 3-point scale (excellent, moderate, poor. Results: Arterial territory maps were generated for all 22 patients. The median difference in arterial territory volumes between investigators was 2.2% [interquartile range (IQR 0.6-8.5%]. Based on expert review, the arterial territory maps and the vessel-selective dynamic CTAs showed excellent consistency with the expected arterial territories in 18 of 22 patients, moderate consistency in 2 patients, and poor consistency in another 2 patients. Conclusion: Using a

  10. Computer systems and methods for visualizing data

    Science.gov (United States)

    Stolte, Chris; Hanrahan, Patrick

    2013-01-29

    A method for forming a visual plot using a hierarchical structure of a dataset. The dataset comprises a measure and a dimension. The dimension consists of a plurality of levels. The plurality of levels form a dimension hierarchy. The visual plot is constructed based on a specification. A first level from the plurality of levels is represented by a first component of the visual plot. A second level from the plurality of levels is represented by a second component of the visual plot. The dataset is queried to retrieve data in accordance with the specification. The data includes all or a portion of the dimension and all or a portion of the measure. The visual plot is populated with the retrieved data in accordance with the specification.

  11. A survey of visualization systems for network security.

    Science.gov (United States)

    Shiravi, Hadi; Shiravi, Ali; Ghorbani, Ali A

    2012-08-01

    Security Visualization is a very young term. It expresses the idea that common visualization techniques have been designed for use cases that are not supportive of security-related data, demanding novel techniques fine tuned for the purpose of thorough analysis. Significant amount of work has been published in this area, but little work has been done to study this emerging visualization discipline. We offer a comprehensive review of network security visualization and provide a taxonomy in the form of five use-case classes encompassing nearly all recent works in this area. We outline the incorporated visualization techniques and data sources and provide an informative table to display our findings. From the analysis of these systems, we examine issues and concerns regarding network security visualization and provide guidelines and directions for future researchers and visual system developers.

  12. Impact of enhanced flow on the flow system and wastewater ...

    African Journals Online (AJOL)

    user

    was used to estimate the impact of the excess flow on sewage-fed wetlands. Two neural network ... 33-2414-6979. The United Nations Economic and Social Development ...... developed so as to restrict the relevant parameters of the wastewater below ... is a highly efficient, low cost, low carbon emission footprint system for.

  13. Two-phase flow in refrigeration systems

    CERN Document Server

    Gu, Junjie; Gan, Zhongxue

    2013-01-01

    Two-Phase Flow in Refrigeration Systems presents recent developments from the authors' extensive research programs on two-phase flow in refrigeration systems. This book covers advanced mass and heat transfer and vapor compression refrigeration systems and shows how the performance of an automotive air-conditioning system is affected through results obtained experimentally and theoretically, specifically with consideration of two-phase flow and oil concentration. The book is ideal for university postgraduate students as a textbook, researchers and professors as an academic reference book, and b

  14. Spatio-temporal flow maps for visualizing movement and contact patterns

    Directory of Open Access Journals (Sweden)

    Bing Ni

    2017-03-01

    Full Text Available The advanced telecom technologies and massive volumes of intelligent mobile phone users have yielded a huge amount of real-time data of people’s all-in-one telecommunication records, which we call telco big data. With telco data and the domain knowledge of an urban city, we are now able to analyze the movement and contact patterns of humans in an unprecedented scale. Flow map is widely used to display the movements of humans from one single source to multiple destinations by representing locations as nodes and movements as edges. However, it fails the task of visualizing both movement and contact data. In addition, analysts often need to compare and examine the patterns side by side, and do various quantitative analysis. In this work, we propose a novel spatio-temporal flow map layout to visualize when and where people from different locations move into the same places and make contact. We also propose integrating the spatiotemporal flow maps into existing spatiotemporal visualization techniques to form a suite of techniques for visualizing the movement and contact patterns. We report a potential application the proposed techniques can be applied to. The results show that our design and techniques properly unveil hidden information, while analysis can be achieved efficiently. Keywords: Spatio-temporal data, Flow map, Urban mobility

  15. Visualizing Student Flows: Busting Myths about Student Movement and Success

    Science.gov (United States)

    Heileman, Gregory L.; Babbitt, Terry H.; Abdallah, Chaouki T.

    2015-01-01

    Many institutions are trying to better understand the factors that drive student success and failure in order to improve the efficiency of degree production. Traditional academic reporting systems are not adequate for this purpose, since they are designed to measure outcomes, not to uncover the factors that influence them. To address this problem,…

  16. VLT Data Flow System Begins Operation

    Science.gov (United States)

    1999-06-01

    new Digital Versatile Disks (DVD ROMs) - of the same physical size - can store up 3.9 Gigabytes (3,900,000,000 bytes) each, or over 6 times more. The VLT will eventually produce more than 20 Gigabytes (20,000,000,000 bytes) of astronomical data every night, corresponding to about 10 million pages of text [2]. Some of these data also pass through "software pipelines" that automatically remove the instrumental effects on the data and deliver data products to the astronomer that can more readily be turned into scientific results. Ultimately these data are stored in a permanent Science Archive Facility at ESO headquarters which is jointly operated by ESO and the Space Telescope European Coordinating Facility (ST-ECF). From here, data are distributed to astronomers on CD ROMs and over the World Wide Web. The archive facility is being developed to enable astronomers to "mine" the large volumes of data that will be collected from the VLT in the coming years. Within the first five years of operations the VLT is expected to produce around 100 Terabytes (100,000,000,000,000 bytes) of data. It is difficult to visualize this enormous amount of information. However, it corresponds to the content of 50 million books of 1000 pages each; they would occupy some 2,500 kilometres of bookshelves! The VLT Data Flow System enters into operation ESO PR Photo 25c/99 ESO PR Photo 25c/99 [Preview - JPEG: 400 x 444 pix - 164k] [Normal - JPEG: 800 x 887 pix - 552k] [High-Res - JPEG: 3000 x 3327 pix - 6.4M] Caption to ESO PR Photo 25c/99 : Astronomers from ESO Data Flow Operations Group at work with the VLT Archive. Science operations with the first VLT 8.2-m telescope ( ANTU ) began on April 1, 1999. Following the first call for proposals to use the VLT in October 1998, the OPC met in December and the observing schedule was finalized early 1999. The related Observation Blocks were prepared by the astronomers in February and March. Service-mode observations began in April and by late May the

  17. The flow of a thin liquid film on a stationary and rotating disk. I - Experimental analysis and flow visualization

    Science.gov (United States)

    Thomas, S.; Faghri, A.; Hankey, W.

    1990-01-01

    The mean thickness of a thin liquid film of deionized water with a free surface on a stationary and rotating horizontal disk has been measured with a nonobtrusive capacitance technique. The measurements were taken when the rotational speed was 0-300 RPM and the flow rate was 7.0-15.0 LPM. A flow visualization study of the thin film was also performed to determine the characteristics of the waves on the free surface. When the disk was stationary, a circular hydraulic jump was present on the disk. Surface waves were found in the supercritical and subcritical regions at all flow rates studied. When the rotational speed of the disk is low, a standing wave at the edge of the disk was present. As the rotational speed increased, the surface waves changed from the wavy-laminar region to a region in which the waves ran nearly radially across the disk on top of a thin substrate of fluid.

  18. Flow Visualization at Cryogenic Conditions Using a Modified Pressure Sensitive Paint Approach

    Science.gov (United States)

    Watkins, A. Neal; Goad, William K.; Obara, Clifford J.; Sprinkle, Danny R.; Campbell, Richard L.; Carter, Melissa B.; Pendergraft, Odis C., Jr.; Bell, James H.; Ingram, JoAnne L.; Oglesby, Donald M.

    2005-01-01

    A modification to the Pressure Sensitive Paint (PSP) method was used to visualize streamlines on a Blended Wing Body (BWB) model at full-scale flight Reynolds numbers. In order to achieve these conditions, the tests were carried out in the National Transonic Facility operating under cryogenic conditions in a nitrogen environment. Oxygen is required for conventional PSP measurements, and several tests have been successfully completed in nitrogen environments by injecting small amounts (typically < 3000 ppm) of oxygen into the flow. A similar technique was employed here, except that air was purged through pressure tap orifices already existent on the model surface, resulting in changes in the PSP wherever oxygen was present. The results agree quite well with predicted results obtained through computational fluid dynamics analysis (CFD), which show this to be a viable technique for visualizing flows without resorting to more invasive procedures such as oil flow or minitufts.

  19. Two phase flow measurement and visualization using Wire Mesh Sensors (WMS)

    International Nuclear Information System (INIS)

    Rajalakshmi, R.; Robin, Roshini; Rama Rao, A.

    2016-01-01

    Two phase flow behavior studies have gained importance in nuclear power plants to enhance fuel performance and safety. In this paper, taking into consideration low cost, high space-time resolution and instantaneous mapping, electrical sensors such as wire mesh sensors (WMS) is proposed for measurement of void distribution and its visualization. The sensor works on the conductivity principle and by measuring the variations in conductivity values of the two phases, the flow distributions can be identified. This paper describes the conceptual design of the WMS for two phase void measurements, Mathematical modeling of the sensor for data evaluation, modeling of the sensor geometry and FEM simulation studies for optimizing sensor geometry and excitation parameters, CFD two phase flows simulations, development of suitable algorithm and programming for two phase visualization and void distribution studies, prototype sensor fabrication and testing

  20. Flow visualization and velocity measurement in a small-scale open channel using an electron microscope

    International Nuclear Information System (INIS)

    Yasuda, K; Sogo, M; Iwamoto, Y

    2013-01-01

    The present note describes a method for use in conjunction with a scanning electron microscope (SEM) that has been developed to visualize a liquid flow under a high-level vacuum and to measure a velocity field in a small-scale flow through an open channel. In general, liquid cannot be observed via a SEM, because liquid evaporates under the high-vacuum environment of the SEM. As such, ionic liquid and room temperature molten salt having a vapor pressure of nearly zero is used in the present study. We use ionic liquid containing Au-coated tracer particles to visualize a small-scale flow under a SEM. Furthermore, the velocity distribution in the open channel is obtained by particle tracking velocimetry measurement and a parabolic profile is confirmed. (technical design note)

  1. Velocity Vector Field Visualization of Flow in Liquid Acquisition Device Channel

    Science.gov (United States)

    McQuillen, John B.; Chao, David F.; Hall, Nancy R.; Zhang, Nengli

    2012-01-01

    A capillary flow liquid acquisition device (LAD) for cryogenic propellants has been developed and tested in NASA Glenn Research Center to meet the requirements of transferring cryogenic liquid propellants from storage tanks to an engine in reduced gravity environments. The prototypical mesh screen channel LAD was fabricated with a mesh screen, covering a rectangular flow channel with a cylindrical outlet tube, and was tested with liquid oxygen (LOX). In order to better understand the performance in various gravity environments and orientations at different liquid submersion depths of the screen channel LAD, a series of computational fluid dynamics (CFD) simulations of LOX flow through the LAD screen channel was undertaken. The resulting velocity vector field visualization for the flow in the channel has been used to reveal the gravity effects on the flow in the screen channel.

  2. Calorimetric and reactor coolant system flow uncertainty

    International Nuclear Information System (INIS)

    Bates, L.; McLean, T.

    1991-01-01

    This paper describes a methodology for the quantification of errors associated with the determination of a feedwater flow, secondary power, and Reactor Coolant System (RCS) flow used at the Trojan Nuclear Plant to ensure compliance with regulatory requirements. The sources of error in Plant indications and process measurement are identified and tracked, using examples, through the mathematical processes necessary to calculate the uncertainty in the RCS flow measurement. An error of approximately 1.4 percent is calculated for secondary power. This error results, along with the consideration of other errors, in an uncertainty of approximately 3 percent in the RCS flow determination

  3. Visualization and void fraction measurement of decompressed boiling flow in a capillary tube

    International Nuclear Information System (INIS)

    Asano, H.; Murakawa, H.; Takenaka, N.; Takiguchi, K.; Okamoto, M.; Tsuchiya, T.; Kitaide, Y.; Maruyama, N.

    2011-01-01

    A capillary tube is often used as a throttle for a refrigerating cycle. Subcooled refrigerant usually flows from a condenser into the capillary tube. Then, the refrigerant is decompressed along the capillary tube. When the static pressure falls below the saturation pressure for the liquid temperature, spontaneous boiling occurs. A vapor-liquid two-phase mixture is discharged from the tube. In designing a capillary tube, it is necessary to calculate the flow rate for given boundary conditions on pressure and temperature at the inlet and exit. Since total pressure loss is dominated by frictional and acceleration losses during two-phase flow, it is first necessary to specify the boiling inception point. However, there will be a delay in boiling inception during decompressed flow. This study aimed to clarify the boiling inception point and two-phase flow characteristics of refrigerant in a capillary tube. Refrigerant flows in a coiled copper capillary tube were visualized by neutron radiography. The one-dimensional distribution of volumetric average void fraction was measured from radiographs through image processing. From the void fraction distribution, the boiling inception point was determined. Moreover, a simplified CT method was successfully applied to a radiograph for cross-sectional measurements. The experimental results show the flow pattern transition from intermittent flow to annular flow that occurred at a void fraction of about 0.45.

  4. PIV Visualization of Bubble Induced Flow Circulation in 2-D Rectangular Pool for Ex-Vessel Debris Bed Coolability

    Energy Technology Data Exchange (ETDEWEB)

    Han, Teayang; Kim, Eunho; Park, Hyun Sun; Moriyama, Kiyofumi [POSTECH, Pohang (Korea, Republic of)

    2015-10-15

    The previous research works demonstrated the debris bed formation on the flooded cavity floor in experiments. Even in the cases the core melt is once solidified, the debris bed can be re-melted due to the decay heat. If the debris bed is not cooled enough by the coolant, the re-melted debris bed will react with the concrete base mat. This situation is called the molten core-concrete interaction (MCCI) which threatens the integrity of the containment by generated gases which pressurize the containment. Therefore securing the long term coolability of the debris bed in the cavity is crucial. According to the previous research works, the natural convection driven by the rising bubbles affects the coolability and the formation of the debris bed. Therefore, clarification of the natural convection characteristics in and around the debris bed is important for evaluation of the coolability of the debris bed. In this study, two-phase flow around the debris bed in a 2D slice geometry is visualized by PIV method to obtain the velocity map of the flow. The DAVINCI-PIV was developed to investigate the flow around the debris bed. In order to simulate the boiling phenomena induced by the decay heat of the debris bed, the air was injected separately by the air chamber system which consists of the 14 air-flowmeters. The circulation flow developed by the rising bubbles was visualized by PIV method.

  5. Flow visualization and aero-optics in simulated environments; Proceedings of the Meeting, Orlando, FL, May 21, 22, 1987

    International Nuclear Information System (INIS)

    Bentley, H.T. III.

    1987-01-01

    The present conference on high speed aerooptics facilities, aerodynamic holography, and photooptical techniques gives attention to the prediction of image degradation through a turbulent medium, wind tunnel studies of optical beam degradation through heterogeneous aerodynamic flows, wavelength effects on images formed through turbulence, holographic visualizations of hypersonic flow viscous interactions, holographic interferometry for gas flow pattern studies, and a holographic flow field analysis of Spacelab-3 crystal growth experiments. Also discussed are the interferometric reconstruction of continuous flow fields, the flow visualization of turbine film cooling flows, the use of the phosphor technique for remote thermometry in a combustor, pulsed laser cinematography of deflagration, and a digital image sequence analysis for optical flow computation in flame propagation visualization

  6. Visualization system for grid environment in the nuclear field

    International Nuclear Information System (INIS)

    Suzuki, Yoshio; Matsumoto, Nobuko; Idomura, Yasuhiro; Tani, Masayuki

    2006-01-01

    An innovative scientific visualization system is needed to integratedly visualize large amount of data which are distributedly generated in remote locations as a result of a large-scale numerical simulation using a grid environment. One of the important functions in such a visualization system is a parallel visualization which enables to visualize data using multiple CPUs of a supercomputer. The other is a distributed visualization which enables to execute visualization processes using a local client computer and remote computers. We have developed a toolkit including these functions in cooperation with the commercial visualization software AVS/Express, called Parallel Support Toolkit (PST). PST can execute visualization processes with three kinds of parallelism (data parallelism, task parallelism and pipeline parallelism) using local and remote computers. We have evaluated PST for large amount of data generated by a nuclear fusion simulation. Here, two supercomputers Altix3700Bx2 and Prism installed in JAEA are used. From the evaluation, it can be seen that PST has a potential to efficiently visualize large amount of data in a grid environment. (author)

  7. Development of an automatic visual grading system for grafting seedlings

    Directory of Open Access Journals (Sweden)

    Subo Tian

    2017-01-01

    Full Text Available In this study, a visual grading system of vegetable grafting machine was developed. The study described key technology of visual grading system of vegetable grafting machine. First, the contrasting experiment was conducted between acquired images under blue background light and natural light conditions, with the blue background light chosen as lighting source. The Visual C++ platform with open-source computer vision library (Open CV was used for the image processing. Subsequently, maximum frequency of total number of 0-valued pixels was predicted and used to extract the measurements of scion and rootstock stem diameters. Finally, the developed integrated visual grading system was experimented with 100 scions and rootstock seedlings. The results showed that success rate of grading reached up to 98%. This shows that selection and grading of scion and rootstock could be fully automated with this developed visual grading system. Hence, this technology would be greatly helpful for improving the grading accuracy and efficiency.

  8. Compressed-air flow control system.

    Science.gov (United States)

    Bong, Ki Wan; Chapin, Stephen C; Pregibon, Daniel C; Baah, David; Floyd-Smith, Tamara M; Doyle, Patrick S

    2011-02-21

    We present the construction and operation of a compressed-air driven flow system that can be used for a variety of microfluidic applications that require rapid dynamic response and precise control of multiple inlet streams. With the use of inexpensive and readily available parts, we describe how to assemble this versatile control system and further explore its utility in continuous- and pulsed-flow microfluidic procedures for the synthesis and analysis of microparticles.

  9. Color surface-flow visualization of fin-generated shock wave boundary-layer interactions

    Science.gov (United States)

    Lu, F. K.; Settles, G. S.

    1990-03-01

    Kerosene-lampblack mixtures with addition of a ground colored chalk were used in an experiment on visualizing surface flows of swept shock boundary-layer interactions. The results show that contrasting colors intensify the visualization of different regions of the interaction surface, and help the eye in following the fine streaks to locate the upstream influence. The study confirms observations of the separation occurring at shock strength below accepted values. The superiority of the reported technique over the previous monochrome technique is demonstrated.

  10. Flow visualization study of inverted annular flow of post dryout heat transfer region

    International Nuclear Information System (INIS)

    Ishii, M.; De Jarlais, G.

    1985-01-01

    The inverted annular flow is important in the area of LWR accident analysis in terms of the maximum cladding temperature and effectiveness of the emergency core cooling. However, the inverted annular flow thermal-hydraulics is not well understood due to its special heat transfer condition of film boiling. In view of this, the inverted flow is studied in detail experimentally. A new experimental apparatus has been constructed in which film boiling heat transfer can be established in a transparent test section. Data on liquid core stability, core break-up mechanism, and dispersed-core liquid slug and droplet sizes are obtained using F 113 as a test fluid. Both high speed movies and flash photographs are used

  11. Visualizing astrophysical N-body systems

    International Nuclear Information System (INIS)

    Dubinski, John

    2008-01-01

    I begin with a brief history of N-body simulation and visualization and then go on to describe various methods for creating images and animations of modern simulations in cosmology and galactic dynamics. These techniques are incorporated into a specialized particle visualization software library called MYRIAD that is designed to render images within large parallel N-body simulations as they run. I present several case studies that explore the application of these methods to animations in star clusters, interacting galaxies and cosmological structure formation.

  12. Computational modeling of unsteady third-grade fluid flow over a vertical cylinder: A study of heat transfer visualization

    Science.gov (United States)

    Reddy, G. Janardhana; Hiremath, Ashwini; Kumar, Mahesh

    2018-03-01

    The present paper aims to investigate the effect of Prandtl number for unsteady third-grade fluid flow over a uniformly heated vertical cylinder using Bejan's heat function concept. The mathematical model of this problem is given by highly time-dependent non-linear coupled equations and are resolved by an efficient unconditionally stable implicit scheme. The time histories of average values of momentum and heat transport coefficients as well as the steady-state flow variables are displayed graphically for distinct values of non-dimensional control parameters arising in the system. As the non-dimensional parameter value gets amplified, the time taken for the fluid flow variables to attain the time-independent state is decreasing. The dimensionless heat function values are closely associated with an overall rate of heat transfer. Thermal energy transfer visualization implies that the heat function contours are compact in the neighborhood of the leading edge of the hot cylindrical wall. It is noticed that the deviations of flow-field variables from the hot wall for a non-Newtonian third-grade fluid flow are significant compared to the usual Newtonian fluid flow.

  13. Bioinspired sensory systems for local flow characterization

    Science.gov (United States)

    Colvert, Brendan; Chen, Kevin; Kanso, Eva

    2016-11-01

    Empirical evidence suggests that many aquatic organisms sense differential hydrodynamic signals.This sensory information is decoded to extract relevant flow properties. This task is challenging because it relies on local and partial measurements, whereas classical flow characterization methods depend on an external observer to reconstruct global flow fields. Here, we introduce a mathematical model in which a bioinspired sensory array measuring differences in local flow velocities characterizes the flow type and intensity. We linearize the flow field around the sensory array and express the velocity gradient tensor in terms of frame-independent parameters. We develop decoding algorithms that allow the sensory system to characterize the local flow and discuss the conditions under which this is possible. We apply this framework to the canonical problem of a circular cylinder in uniform flow, finding excellent agreement between sensed and actual properties. Our results imply that combining suitable velocity sensors with physics-based methods for decoding sensory measurements leads to a powerful approach for understanding and developing underwater sensory systems.

  14. Postural response to predictable and nonpredictable visual flow in children and adults.

    Science.gov (United States)

    Schmuckler, Mark A

    2017-11-01

    Children's (3-5years) and adults' postural reactions to different conditions of visual flow information varying in its frequency content was examined using a moving room apparatus. Both groups experienced four conditions of visual input: low-frequency (0.20Hz) visual oscillations, high-frequency (0.60Hz) oscillations, multifrequency nonpredictable visual input, and no imposed visual information. Analyses of the frequency content of anterior-posterior (AP) sway revealed that postural reactions to the single-frequency conditions replicated previous findings; children were responsive to low- and high-frequency oscillations, whereas adults were responsive to low-frequency information. Extending previous work, AP sway in response to the nonpredictable condition revealed that both groups were responsive to the different components contained in the multifrequency visual information, although adults retained their frequency selectivity to low-frequency versus high-frequency content. These findings are discussed in relation to work examining feedback versus feedforward control of posture, and the reweighting of sensory inputs for postural control, as a function of development and task context. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Verbal or Visual Memory Score and Regional Cerebral Blood Flow in Alzheimer Disease

    Directory of Open Access Journals (Sweden)

    Satoshi Hayashi

    2018-01-01

    Full Text Available Objective: Among many cognitive function deficits, memory impairment is an initial and cardinal symptom in Alzheimer disease (AD. In most cases, verbal and visual memory scores correlate highly, but in some cases the deficit of verbal or visual memory is very different from that of the other memory. In this study, we examined the neural substrates of verbal and visual memory in patients with AD. Methods: One hundred eighty-eight consecutive patients with AD were recruited from outpatient units. Verbal and visual memory scores were evaluated using the Wechsler Memory Scale – revised. The patients underwent brain SPECT with 99mTc-ethylcysteinate dimer. Results: After removing the effects of age, sex, education, and Mini-Mental State Examination scores, correlation analysis showed a significant correlation of verbal memory scores to regional cerebral blood flow (rCBF in the bilateral cingulate gyrus and left precuneus. Similarly, a significant correlation of visual memory scores to rCBF was found in the right precuneus and right cingulate gyrus. Conclusion: The posterior medial cortices (PMC are very important areas in episodic memory among patients with mild AD. Verbal memory is more closely related to the both sides of the PMC, while visual memory is more closely related to the right PMC.

  16. Verbal or Visual Memory Score and Regional Cerebral Blood Flow in Alzheimer Disease.

    Science.gov (United States)

    Hayashi, Satoshi; Terada, Seishi; Oshima, Etsuko; Sato, Shuhei; Kurisu, Kairi; Takenoshita, Shintaro; Yokota, Osamu; Yamada, Norihito

    2018-01-01

    Among many cognitive function deficits, memory impairment is an initial and cardinal symptom in Alzheimer disease (AD). In most cases, verbal and visual memory scores correlate highly, but in some cases the deficit of verbal or visual memory is very different from that of the other memory. In this study, we examined the neural substrates of verbal and visual memory in patients with AD. One hundred eighty-eight consecutive patients with AD were recruited from outpatient units. Verbal and visual memory scores were evaluated using the Wechsler Memory Scale - revised. The patients underwent brain SPECT with 99m Tc-ethylcysteinate dimer. After removing the effects of age, sex, education, and Mini-Mental State Examination scores, correlation analysis showed a significant correlation of verbal memory scores to regional cerebral blood flow (rCBF) in the bilateral cingulate gyrus and left precuneus. Similarly, a significant correlation of visual memory scores to rCBF was found in the right precuneus and right cingulate gyrus. The posterior medial cortices (PMC) are very important areas in episodic memory among patients with mild AD. Verbal memory is more closely related to the both sides of the PMC, while visual memory is more closely related to the right PMC.

  17. Flow Battery System Design for Manufacturability.

    Energy Technology Data Exchange (ETDEWEB)

    Montoya, Tracy Louise; Meacham, Paul Gregory; Perry, David; Broyles, Robin S.; Hickey, Steven; Hernandez, Jacquelynne

    2014-10-01

    Flow battery energy storage systems can support renewable energy generation and increase energy efficiency. But, presently, the costs of flow battery energy storage systems can be a significant barrier for large-scale market penetration. For cost- effective systems to be produced, it is critical to optimize the selection of materials and components simultaneously with the adherence to requirements and manufacturing processes to allow these batteries and their manufacturers to succeed in the market by reducing costs to consumers. This report analyzes performance, safety, and testing requirements derived from applicable regulations as well as commercial and military standards that would apply to a flow battery energy storage system. System components of a zinc-bromine flow battery energy storage system, including the batteries, inverters, and control and monitoring system, are discussed relative to manufacturing. The issues addressed include costs and component availability and lead times. A service and support model including setup, maintenance and transportation is outlined, along with a description of the safety-related features of the example flow battery energy storage system to promote regulatory and environmental, safety, and health compliance in anticipation of scale manufacturing.

  18. Relationship Between Ureteral Jet Flow, Visual Analogue Scale, and Ureteral Stone Size.

    Science.gov (United States)

    Ongun, Sakir; Teken, Abdurrazak; Yılmaz, Orkun; Süleyman, Sakir

    2017-06-01

    To contribute to the diagnosis and treatment of ureteral stones by investigating the relationship between the ureteral jet flow measurements of patients with ureteral stones and the size of the stones and the patients' pain scores. The sample consisted of patients who presented acute renal colic between December 2014 and 2015 and from a noncontrast computed tomography were found to have a urinary stone. The ureteral jet flow velocities were determined using Doppler ultrasonography. The patients were all assessed in terms of stone size, localization and area, anteroposterior pelvis (AP) diameter, and visual analogue scale (VAS) scores. A total of 102 patients were included in the study. As the VAS score decreased, the peak jet flow velocity on the stone side increased, whereas the flow velocity on the other side, AP diameter, and stone area were reduced (P flow velocity was reduced and the AP diameter increased significantly (P flow was not observed in 17 patients on the stone side. A statistically significant difference was found between these patients and the remaining patients in terms of all parameters (P flow velocity of ureteral jet is low and with a severe level of pain or the peak flow velocity of ureteral jet cannot be measured, there is a low possibility of spontaneous passage and a high possibility of a large stone, and therefore the treatment should be started immediately. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Flow visualization study of inverted annular flow of post dryout heat transfer region

    International Nuclear Information System (INIS)

    Ishii, M.; De Jarlais, G.

    1987-01-01

    The inverted annular flow is important in the area of LWR accident analysis in terms of the maximum cladding temperature and effectiveness of the emergency core cooling. However, the inverted annular flow thermal-hydraulics is not well understood due to its special heat transfer condition of film boiling. In view of this, the inverted flow is studied in detail experimentally. A new experimental apparatus has been constructed in which film boiling heat transfer can be established in a transparent test section. Data on liquid core stability, core break-up mechanism, and dispersed-core liquid slug and droplet sizes are obtained using F 113 as a test fluid. Both high speed movies and flash photographs are used. The inlet section consists of specially designed coaxial nozzles for gas and liquid such that the ideal inverted annular flow can be generated. The roll wave formation, droplet entrainment from wave crests, agitated sections with large interfacial areas, classical sinuous jet instability, jet break-up into multiple liquid ligaments and drop formation from liquid ligaments have been observed in detail. (orig.)

  20. JPEG2000 COMPRESSION CODING USING HUMAN VISUAL SYSTEM MODEL

    Institute of Scientific and Technical Information of China (English)

    Xiao Jiang; Wu Chengke

    2005-01-01

    In order to apply the Human Visual System (HVS) model to JPEG2000 standard,several implementation alternatives are discussed and a new scheme of visual optimization isintroduced with modifying the slope of rate-distortion. The novelty is that the method of visual weighting is not lifting the coefficients in wavelet domain, but is complemented by code stream organization. It remains all the features of Embedded Block Coding with Optimized Truncation (EBCOT) such as resolution progressive, good robust for error bit spread and compatibility of lossless compression. Well performed than other methods, it keeps the shortest standard codestream and decompression time and owns the ability of VIsual Progressive (VIP) coding.

  1. How humans use visual optic flow to regulate stepping during walking.

    Science.gov (United States)

    Salinas, Mandy M; Wilken, Jason M; Dingwell, Jonathan B

    2017-09-01

    Humans use visual optic flow to regulate average walking speed. Among many possible strategies available, healthy humans walking on motorized treadmills allow fluctuations in stride length (L n ) and stride time (T n ) to persist across multiple consecutive strides, but rapidly correct deviations in stride speed (S n =L n /T n ) at each successive stride, n. Several experiments verified this stepping strategy when participants walked with no optic flow. This study determined how removing or systematically altering optic flow influenced peoples' stride-to-stride stepping control strategies. Participants walked on a treadmill with a virtual reality (VR) scene projected onto a 3m tall, 180° semi-cylindrical screen in front of the treadmill. Five conditions were tested: blank screen ("BLANK"), static scene ("STATIC"), or moving scene with optic flow speed slower than ("SLOW"), matched to ("MATCH"), or faster than ("FAST") walking speed. Participants took shorter and faster strides and demonstrated increased stepping variability during the BLANK condition compared to the other conditions. Thus, when visual information was removed, individuals appeared to walk more cautiously. Optic flow influenced both how quickly humans corrected stride speed deviations and how successful they were at enacting this strategy to try to maintain approximately constant speed at each stride. These results were consistent with Weber's law: healthy adults more-rapidly corrected stride speed deviations in a no optic flow condition (the lower intensity stimuli) compared to contexts with non-zero optic flow. These results demonstrate how the temporal characteristics of optic flow influence ability to correct speed fluctuations during walking. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Visualization of diffusion mixing in a micro-mixer with flow paths fabricated by photolithography

    Science.gov (United States)

    Horiuchi, Toshiyuki; Morizane, Yuta

    2017-09-01

    Mixing processes of two liquids were investigated by visualizing the mixing when they were simultaneously injected in a micro-mixer with lithographically fabricated Y-shape flow paths, and the mixing phenomena was analyzed in detail. To visualize the mixing, flows were observed by an optical microscope, and a clearly detectable chemical reaction was utilized. As the two liquids, a transparent aqueous solution of a strong alkali and a phenolphthalein ethanol solution were used. When they were simultaneously injected in Y-shape flow paths of a micro-mixer, they flowed at first in parallel along the joined path as laminar flows. This is because the Reynolds' number became very small caused by the narrow flow-path widths of 50-100 μm. However, because two liquids were always contacted at the boundary, they were gradually mixed by diffusion, and the color of the mixed parts changed to vivid red. For this reason, it was able to measure the diffusion distance from the flow path center. Because the flow speeds were much faster than the diffusion speeds, the area colored in red did not depend on the time but depended on the distance from the joint point. It was known that the distance from the joint point corresponded to the time for mixing the liquids by the diffusion. It was clarified that the diffusion distance x was proportional to the square root of the diffusion time t or the distance from the joint point. The calculated diffusion coefficient D was (0.87-1.00)×10-9 m2/s.

  3. Advanced Visualization Software System for Nuclear Power Plant Inspection

    International Nuclear Information System (INIS)

    Kukic, I.; Jambresic, D.; Reskovic, S.

    2006-01-01

    Visualization techniques have been widely used in industrial environment for enhancing process control. Traditional techniques of visualization are based on control panels with switches and lights, and 2D graphic representations of processes. However, modern visualization systems enable significant new opportunities in creating 3D virtual environments. These opportunities arise from the availability of high end graphics capabilities in low cost personal computers. In this paper we describe implementation of process visualization software, developed by INETEC. This software is used to visualize testing equipment, components being tested and the overall power plant inspection process. It improves security of the process due to its real-time visualization and collision detection capabilities, and therefore greatly enhances the inspection process. (author)

  4. Determination of Critical Properties of Endothermic Hydrocarbon Fuel RP-3 Based on Flow Visualization

    Science.gov (United States)

    Wang, Ning; Zhou, Jin; Pan, Yu; Wang, Hui

    2014-01-01

    The critical pressure and temperature of an endothermic hydrocarbon fuel RP-3 were determined by flow visualization. The flow pattern images of RP-3 at different pressures and temperatures were obtained. The critical pressure is identified by disappearance of the phase change while the critical temperature is determined by appearance of the opalescence phenomenon under the critical pressure. The opalescence phenomenon is unique to the critical point. The critical pressure and temperature of RP-3 are determined to be 2.3 MPa and 646 K, respectively.

  5. Experimental consideration for realizing image based visual servo control system

    International Nuclear Information System (INIS)

    Ishikawa, N.; Suzuki, K.; Fujii, Y.; Usui, H.

    1995-01-01

    In this study, we consider the experimental aspect of image based visual servo control system. The items considered are the following; 1) Inertial parameter estimation, 2) Focal point estimation, 3) Controller performance for the system with delay. From the experimental result of visual control, it is found that the system is very sensitive to the controller gain because of the computational delay of vision. In order to establish a satisfactory delay compensation, more investigations on controller design are required. (author)

  6. Drain Back, Low Flow Solar Combi Systems

    DEFF Research Database (Denmark)

    Perers, Bengt; Furbo, Simon; Fan, Jianhua

    2014-01-01

    Drain Back systems with ETC collectors are tested and analyzed in a Danish - Chinese cooperation project. Experiences from early work at DTU, with drain back, low flow systems, was used to design two systems: 1) One laboratory system at DTU and 2) One demonstration system in a single family house...... in Sorö Denmark. Detailed monitoring and modelling of the system in the DTU lab is done to be able to generalize the results, to other climates and loads and to make design optimizations. The advantage with drain back, low flow systems, is that the system can be made more simple with less components...... and that the performance can be enhanced. A combination of the drain back- and system expansion vessel was tested successfully. Small initial problems with installation and proposals for design improvements to avoid these in practice are described in the paper. Installer education and training is an important step to have...

  7. A proposed intracortical visual prosthesis image processing system.

    Science.gov (United States)

    Srivastava, N R; Troyk, P

    2005-01-01

    It has been a goal of neuroprosthesis researchers to develop a system, which could provide artifical vision to a large population of individuals with blindness. It has been demonstrated by earlier researches that stimulating the visual cortex area electrically can evoke spatial visual percepts, i.e. phosphenes. The goal of visual cortex prosthesis is to stimulate the visual cortex area and generate a visual perception in real time to restore vision. Even though the normal working of the visual system is not been completely understood, the existing knowledge has inspired research groups to develop strategies to develop visual cortex prosthesis which can help blind patients in their daily activities. A major limitation in this work is the development of an image proceessing system for converting an electronic image, as captured by a camera, into a real-time data stream for stimulation of the implanted electrodes. This paper proposes a system, which will capture the image using a camera and use a dedicated hardware real time image processor to deliver electrical pulses to intracortical electrodes. This system has to be flexible enough to adapt to individual patients and to various strategies of image reconstruction. Here we consider a preliminary architecture for this system.

  8. Visualization of velocity field and phase distribution in gas-liquid two-phase flow by NMR imaging

    International Nuclear Information System (INIS)

    Matsui, G.; Monji, H.; Obata, J.

    2004-01-01

    NMR imaging has been applied in the field of fluid mechanics, mainly single phase flow, to visualize the instantaneous flow velocity field. In the present study, NMR imaging was used to visualize simultaneously both the instantaneous phase structure and velocity field of gas-liquid two-phase flow. Two methods of NMR imaging were applied. One is useful to visualize both the one component of liquid velocity and the phase distribution. This method was applied to horizontal two-phase flow and a bubble rising in stagnant oil. It was successful in obtaining some pictures of velocity field and phase distribution on the cross section of the pipe. The other is used to visualize a two-dimensional velocity field. This method was applied to a bubble rising in a stagnant water. The velocity field was visualized after and before the passage of a bubble at the measuring cross section. Furthermore, the distribution of liquid velocity was obtained. (author)

  9. Modular load flow for restructured power systems

    CERN Document Server

    Hariharan, M V; Gupta, Pragati P

    2016-01-01

    In the subject of power systems, authors felt that a re-look is necessary at some conventional methods of analysis. In this book, the authors have subjected the time-honoured load flow to a close scrutiny. Authors have discovered and discussed a new load flow procedure – Modular Load Flow. Modular Load Flow explores use of power – a scalar – as source for electrical circuits which are conventionally analysed by means of phasors – the ac voltages or currents. The method embeds Kirchhoff’s circuit laws as topological property into its scalar equations and results in a unique wonderland where phase angles do not exist! Generators are shown to have their own worlds which can be superimposed to obtain the state of the composite power system. The treatment is useful in restructured power systems where stakeholders and the system operators may desire to know individual generator contributions in line flows and line losses for commercial reasons. Solution in Modular Load Flow consists of explicit expression...

  10. Visualizing flow fields using acoustic Doppler current profilers and the Velocity Mapping Toolbox

    Science.gov (United States)

    Jackson, P. Ryan

    2013-01-01

    The purpose of this fact sheet is to provide examples of how the U.S. Geological Survey is using acoustic Doppler current profilers for much more than routine discharge measurements. These instruments are capable of mapping complex three-dimensional flow fields within rivers, lakes, and estuaries. Using the Velocity Mapping Toolbox to process the ADCP data allows detailed visualization of the data, providing valuable information for a range of studies and applications.

  11. 4D flow MR imaging of the portal venous system: a feasibility study in children

    Energy Technology Data Exchange (ETDEWEB)

    Parekh, Keyur; Rose, Michael; Popescu, Andrada; Rigsby, Cynthia K. [Ann and Robert H. Lurie Children' s Hospital of Chicago, Department of Medical Imaging, Chicago, IL (United States); Northwestern University, Department of Radiology, Feinberg School of Medicine, Chicago, IL (United States); Markl, Michael [Northwestern University, Department of Radiology, Feinberg School of Medicine, Chicago, IL (United States); McCormick School of Engineering, Northwestern University, Department of Biomedical Engineering, Chicago, IL (United States); Schnell, Susanne [Northwestern University, Department of Radiology, Feinberg School of Medicine, Chicago, IL (United States)

    2017-02-15

    To determine the feasibility of 4D flow MRI for visualization and quantification of the portal venous haemodynamics in children and young adults. 4D flow was performed in 28 paediatric patients (median age, 8.5 years; interquartile range, 5.2-16.5), 15 with non-operated native portal system and 13 with surgically created portal shunt. Image quality assessment for 3D flow visualization and flow pattern analyses was performed. Regional 4D flow peak velocity and net flow were compared with 2D-cine phase contrast MRI (2D-PC MR) in the post-surgical patients. Mean 3D flow visualization quality score was excellent (mean ± SD, 4.2 ± 0.9) with good inter-rater agreement (κ,0.67). Image quality in children aged >10 years was better than children ≤10 years (p < 0.05). Flow pattern was defined for portal, superior mesenteric, splenic veins and splenic artery in all patients. 4D flow and 2D-PC MR peak velocity and net flow were similar with good correlation (peak velocity: 4D flow 22.2 ± 9.1 cm/s and 2D-PC MR 25.2 ± 11.2 cm/s, p = 0.46; r = 0.92, p < 0.0001; net flow: 4D flow 9.5 ± 7.4 ml/s and 2D-PC MR 10.1 ± 7.3 ml/s, p = 0.65; r = 0.81, p = 0.0007). 4D flow MRI is feasible and holds promise for the comprehensive 3D visualization and quantification of portal venous flow dynamics in children and young adults. (orig.)

  12. 4D flow MR imaging of the portal venous system: a feasibility study in children

    International Nuclear Information System (INIS)

    Parekh, Keyur; Rose, Michael; Popescu, Andrada; Rigsby, Cynthia K.; Markl, Michael; Schnell, Susanne

    2017-01-01

    To determine the feasibility of 4D flow MRI for visualization and quantification of the portal venous haemodynamics in children and young adults. 4D flow was performed in 28 paediatric patients (median age, 8.5 years; interquartile range, 5.2-16.5), 15 with non-operated native portal system and 13 with surgically created portal shunt. Image quality assessment for 3D flow visualization and flow pattern analyses was performed. Regional 4D flow peak velocity and net flow were compared with 2D-cine phase contrast MRI (2D-PC MR) in the post-surgical patients. Mean 3D flow visualization quality score was excellent (mean ± SD, 4.2 ± 0.9) with good inter-rater agreement (κ,0.67). Image quality in children aged >10 years was better than children ≤10 years (p < 0.05). Flow pattern was defined for portal, superior mesenteric, splenic veins and splenic artery in all patients. 4D flow and 2D-PC MR peak velocity and net flow were similar with good correlation (peak velocity: 4D flow 22.2 ± 9.1 cm/s and 2D-PC MR 25.2 ± 11.2 cm/s, p = 0.46; r = 0.92, p < 0.0001; net flow: 4D flow 9.5 ± 7.4 ml/s and 2D-PC MR 10.1 ± 7.3 ml/s, p = 0.65; r = 0.81, p = 0.0007). 4D flow MRI is feasible and holds promise for the comprehensive 3D visualization and quantification of portal venous flow dynamics in children and young adults. (orig.)

  13. Flow visualization around cylinders in a channel flow using particle image velocimetry

    International Nuclear Information System (INIS)

    Hassan, Y.A.; Martinez, R.S.; Schmidl, W.D.; Philip, O.G.

    2004-01-01

    One of the major concerns with power plant steam generators is tube vibration caused by turbulent flow buffeting. The vibration can cause wear of the tubes at the tube supports and at tube joints that eventually leads to leaks and rupture. When the cumulative leaks affect the steam generator performance, the plant is shut down and the leaking tubes are either repaired or plugged. Not only is the repair procedure very costly in terms of the repair costs themselves and loss of income due to the plant outage, but it is also costly in the sense that the steam generator design has been altered or has been totally replaced. This normally leads to more repairs in the future. To better understand this behavior of turbulent flow buffeting (the cause of many tube problems), it was felt that quantitative experimental data is needed to test the empirical correlations that predict the behavior of turbulent flow around cylinders. Perhaps this quantitative data could lead to a better understanding of this particular fluid behavior and motion and this understanding would hopefully then lead to design solutions that can be implemented to avoid the problem. (author)

  14. Flow visualization study of inverted annular flow of post dryout heat transfer region

    International Nuclear Information System (INIS)

    Ishii, M.; De Jarlais, G.

    1985-01-01

    The inverted annular flow is important in the area of LWR accident analysis in terms of the maximum cladding temperature and effectiveness of the emergency core cooling. However, the inverted annular flow thermal-hydraulics is not well understood due to its special heat transfer condition of film boiling. The review of existing data indicates further research is needed in the areas of basic hydrodynamics related to liquid core disintegration mechanisms, slug and droplet formation, entrainment, and droplet size distributions. In view of this, the inverted flow is studied in detail experimentally. A new experimental apparatus has been constructed in which film boiling heat transfer can be established in a transparent test section. The test section consists of two coaxial quartz tubes. The annular gap between these two tubes is filled with a hot, clear fluid (syltherm 800) so as to maintain film boiling temperatures and heat transfer rates at the inner quartz tube wall. Data on liquid core stability, core break-up mechanism, and dispersed-core liquid slug and droplet sizes are obtained using F 113 as a test fluid. Both high speed movies and flash photographs (3 μsec) are used

  15. Particle Based Modeling of Electrical Field Flow Fractionation Systems

    Directory of Open Access Journals (Sweden)

    Tonguc O. Tasci

    2015-10-01

    Full Text Available Electrical Field Flow Fractionation (ElFFF is a sub method in the field flow fractionation (FFF family that relies on an applied voltage on the channel walls to effect a separation. ElFFF has fallen behind some of the other FFF methods because of the optimization complexity of its experimental parameters. To enable better optimization, a particle based model of the ElFFF systems has been developed and is presented in this work that allows the optimization of the main separation parameters, such as electric field magnitude, frequency, duty cycle, offset, flow rate and channel dimensions. The developed code allows visualization of individual particles inside the separation channel, generation of realistic fractograms, and observation of the effects of the various parameters on the behavior of the particle cloud. ElFFF fractograms have been generated via simulations and compared with experiments for both normal and cyclical ElFFF. The particle visualizations have been used to verify that high duty cycle voltages are essential to achieve long retention times and high resolution separations. Furthermore, by simulating the particle motions at the channel outlet, it has been demonstrated that the top channel wall should be selected as the accumulation wall for cyclical ElFFF to reduce band broadening and achieve high efficiency separations. While the generated particle based model is a powerful tool to estimate the outcomes of the ElFFF experiments and visualize particle motions, it can also be used to design systems with new geometries which may lead to the design of higher efficiency ElFFF systems. Furthermore, this model can be extended to other FFF techniques by replacing the electrical field component of the model with the fields used in the other FFF techniques.

  16. Iterative development of visual control systems in a research vivarium.

    Science.gov (United States)

    Bassuk, James A; Washington, Ida M

    2014-01-01

    The goal of this study was to test the hypothesis that reintroduction of Continuous Performance Improvement (CPI) methodology, a lean approach to management at Seattle Children's (Hospital, Research Institute, Foundation), would facilitate engagement of vivarium employees in the development and sustainment of a daily management system and a work-in-process board. Such engagement was implemented through reintroduction of aspects of the Toyota Production System. Iterations of a Work-In-Process Board were generated using Shewhart's Plan-Do-Check-Act process improvement cycle. Specific attention was given to the importance of detecting and preventing errors through assessment of the following 5 levels of quality: Level 1, customer inspects; Level 2, company inspects; Level 3, work unit inspects; Level 4, self-inspection; Level 5, mistake proofing. A functioning iteration of a Mouse Cage Work-In-Process Board was eventually established using electronic data entry, an improvement that increased the quality level from 1 to 3 while reducing wasteful steps, handoffs and queues. A visual workplace was realized via a daily management system that included a Work-In-Process Board, a problem solving board and two Heijunka boards. One Heijunka board tracked cage changing as a function of a biological kanban, which was validated via ammonia levels. A 17% reduction in cage changing frequency provided vivarium staff with additional time to support Institute researchers in their mutual goal of advancing cures for pediatric diseases. Cage washing metrics demonstrated an improvement in the flow continuum in which a traditional batch and queue push system was replaced with a supermarket-type pull system. Staff engagement during the improvement process was challenging and is discussed. The collective data indicate that the hypothesis was found to be true. The reintroduction of CPI into daily work in the vivarium is consistent with the 4P Model of the Toyota Way and selected Principles

  17. Iterative development of visual control systems in a research vivarium.

    Directory of Open Access Journals (Sweden)

    James A Bassuk

    Full Text Available The goal of this study was to test the hypothesis that reintroduction of Continuous Performance Improvement (CPI methodology, a lean approach to management at Seattle Children's (Hospital, Research Institute, Foundation, would facilitate engagement of vivarium employees in the development and sustainment of a daily management system and a work-in-process board. Such engagement was implemented through reintroduction of aspects of the Toyota Production System. Iterations of a Work-In-Process Board were generated using Shewhart's Plan-Do-Check-Act process improvement cycle. Specific attention was given to the importance of detecting and preventing errors through assessment of the following 5 levels of quality: Level 1, customer inspects; Level 2, company inspects; Level 3, work unit inspects; Level 4, self-inspection; Level 5, mistake proofing. A functioning iteration of a Mouse Cage Work-In-Process Board was eventually established using electronic data entry, an improvement that increased the quality level from 1 to 3 while reducing wasteful steps, handoffs and queues. A visual workplace was realized via a daily management system that included a Work-In-Process Board, a problem solving board and two Heijunka boards. One Heijunka board tracked cage changing as a function of a biological kanban, which was validated via ammonia levels. A 17% reduction in cage changing frequency provided vivarium staff with additional time to support Institute researchers in their mutual goal of advancing cures for pediatric diseases. Cage washing metrics demonstrated an improvement in the flow continuum in which a traditional batch and queue push system was replaced with a supermarket-type pull system. Staff engagement during the improvement process was challenging and is discussed. The collective data indicate that the hypothesis was found to be true. The reintroduction of CPI into daily work in the vivarium is consistent with the 4P Model of the Toyota Way and

  18. Flow visualization study of two-phase flow in a single bend outlet feeder pipe of a CANDU reactor

    International Nuclear Information System (INIS)

    Savalaxs, S.-A.; Lister, D.H.; Steward, F.R.

    2005-01-01

    In CANDU reactors, the feeder piping that is used to direct the high-temperature water coolant between the fuel channels and the steam generators is made of carbon steel. Since 1996, several CANDU stations have reported excessive corrosion of their outlet feeders. The first metre is particularity vulnerable because the piping there consists of single or double bends, which have relatively thin walls produced by the bending process. Early studies related the attack to the hydrodynamics of the coolant and verified that it was a type of flow-accelerated corrosion. In order to understand the hydrodynamics of the coolant in the outlet feeders by flow visualization, a full-scale transparent test section simulating the geometry and orientation of an outlet feeder bend with its upstream components was fabricated. The feeder consisted of a 54 mm diameter acrylic pipe with a 73 degree bend. This was connected to the upstream component with an acrylic simulation of a Grayloc flanged fitting. A test loop supplied room temperature water to the test section at flow rates up to 0.019 m3/s. Air could be injected into the water to give a mean volume fraction of up to 0.56. In this preliminary investigation, the size and velocity of air bubbles at different flow conditions and their distribution within the pipe bend were studied. Particular attention was paid to the flow pattern at the inside of the bend, where a CFD (computational fluid dynamics) code - Fluent 6.1-had failed to predict a liquid film in an earlier study. A high-speed digital video camera was used to determine the relation between bubble size and velocity. Such a relation should help to explain the discrepancy in the CFD modelling and provide the basis for accurate predictions of phase distribution in complex geometries at high flow rates. (authors)

  19. Experimental comparison and visualization of in-tube continuous and pulsating flow boiling

    DEFF Research Database (Denmark)

    Kærn, Martin Ryhl; Markussen, Wiebke Brix; Meyer, Knud Erik

    2018-01-01

    This experimental study investigated the application of fluid flow pulsations for in-tube flow boiling heat transfer enhancement in an 8 mm smooth round tube made of copper. The fluid flow pulsations were introduced by a flow modulating expansion device and were compared with continuous flow...... cycle time (7 s) reduced the time-averaged heat transfer coefficients by 1.8% and 2.3% for the low and high subcooling, respectively, due to significant dry-out when the flow-modulating expansion valve was closed. Furthermore, the flow pulsations were visualized by high-speed camera to assist...... generated by a stepper-motor expansion valve in terms of the time-averaged heat transfer coefficient. The cycle time ranged from 1 s to 7 s for the pulsations, the time-averaged refrigerant mass flux ranged from 50 kg m−2 s−1 to 194 kg m−2 s−1 and the time-averaged heat flux ranged from 1.1 kW m−2 to 30.6 k...

  20. The effect of visualizing the flow of multimedia content among and inside devices.

    Science.gov (United States)

    Lee, Dong-Seok

    2009-05-01

    This study introduces a user interface, referred to as the flow interface, which provides a graphical representation of the movement of content among and inside audio/video devices. The proposed interface provides a different frame of reference with content-oriented visualization of the generation, manipulation, storage, and display of content as well as input and output. The flow interface was applied to a VCR/DVD recorder combo, one of the most complicated consumer products. A between-group experiment was performed to determine whether the flow interface helps users to perform various tasks and to examine the learning effect of the flow interface, particularly in regard to hooking up and recording tasks. The results showed that participants with access to the flow interface performed better in terms of success rate and elapsed time. In addition, the participants indicated that they could easily understand the flow interface. The potential of the flow interface for application to other audio video devices, and design issues requiring further consideration, are discussed.

  1. Microbial adhesion in flow displacement systems

    NARCIS (Netherlands)

    Busscher, HJ; van der Mei, HC

    Flow displacement systems are superior to many other (static) systems for studying microbial adhesion to surfaces because mass transport and prevailing shear conditions can be adequately controlled and notoriously ill-defined slight rinsing steps to remove so-called "loosely adhering organisms" can

  2. 4D phase contrast flow imaging for in-stent flow visualization and assessment of stent patency in peripheral vascular stents – A phantom study

    International Nuclear Information System (INIS)

    Bunck, Alexander C.; Jüttner, Alena; Kröger, Jan Robert; Burg, Matthias C.; Kugel, Harald; Niederstadt, Thomas; Tiemann, Klaus; Schnackenburg, Bernhard; Crelier, Gerard R.

    2012-01-01

    Purpose: 4D phase contrast flow imaging is increasingly used to study the hemodynamics in various vascular territories and pathologies. The aim of this study was to assess the feasibility and validity of MRI based 4D phase contrast flow imaging for the evaluation of in-stent blood flow in 17 commonly used peripheral stents. Materials and methods: 17 different peripheral stents were implanted into a MR compatible flow phantom. In-stent visibility, maximal velocity and flow visualization were assessed and estimates of in-stent patency obtained from 4D phase contrast flow data sets were compared to a conventional 3D contrast-enhanced magnetic resonance angiography (CE-MRA) as well as 2D PC flow measurements. Results: In all but 3 of the tested stents time-resolved 3D particle traces could be visualized inside the stent lumen. Quality of 4D flow visualization and CE-MRA images depended on stent type and stent orientation relative to the magnetic field. Compared to the visible lumen area determined by 3D CE-MRA, estimates of lumen patency derived from 4D flow measurements were significantly higher and less dependent on stent type. A higher number of stents could be assessed for in-stent patency by 4D phase contrast flow imaging (n = 14) than by 2D phase contrast flow imaging (n = 10). Conclusions: 4D phase contrast flow imaging in peripheral vascular stents is feasible and appears advantageous over conventional 3D contrast-enhanced MR angiography and 2D phase contrast flow imaging. It allows for in-stent flow visualization and flow quantification with varying quality depending on stent type

  3. 4D phase contrast flow imaging for in-stent flow visualization and assessment of stent patency in peripheral vascular stents--a phantom study.

    Science.gov (United States)

    Bunck, Alexander C; Jüttner, Alena; Kröger, Jan Robert; Burg, Matthias C; Kugel, Harald; Niederstadt, Thomas; Tiemann, Klaus; Schnackenburg, Bernhard; Crelier, Gerard R; Heindel, Walter; Maintz, David

    2012-09-01

    4D phase contrast flow imaging is increasingly used to study the hemodynamics in various vascular territories and pathologies. The aim of this study was to assess the feasibility and validity of MRI based 4D phase contrast flow imaging for the evaluation of in-stent blood flow in 17 commonly used peripheral stents. 17 different peripheral stents were implanted into a MR compatible flow phantom. In-stent visibility, maximal velocity and flow visualization were assessed and estimates of in-stent patency obtained from 4D phase contrast flow data sets were compared to a conventional 3D contrast-enhanced magnetic resonance angiography (CE-MRA) as well as 2D PC flow measurements. In all but 3 of the tested stents time-resolved 3D particle traces could be visualized inside the stent lumen. Quality of 4D flow visualization and CE-MRA images depended on stent type and stent orientation relative to the magnetic field. Compared to the visible lumen area determined by 3D CE-MRA, estimates of lumen patency derived from 4D flow measurements were significantly higher and less dependent on stent type. A higher number of stents could be assessed for in-stent patency by 4D phase contrast flow imaging (n=14) than by 2D phase contrast flow imaging (n=10). 4D phase contrast flow imaging in peripheral vascular stents is feasible and appears advantageous over conventional 3D contrast-enhanced MR angiography and 2D phase contrast flow imaging. It allows for in-stent flow visualization and flow quantification with varying quality depending on stent type. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  4. Bio-inspired modeling and implementation of the ocelli visual system of flying insects.

    Science.gov (United States)

    Gremillion, Gregory; Humbert, J Sean; Krapp, Holger G

    2014-12-01

    Two visual sensing modalities in insects, the ocelli and compound eyes, provide signals used for flight stabilization and navigation. In this article, a generalized model of the ocellar visual system is developed for a 3-D visual simulation environment based on behavioral, anatomical, and electrophysiological data from several species. A linear measurement model is estimated from Monte Carlo simulation in a cluttered urban environment relating state changes of the vehicle to the outputs of the ocellar model. A fully analog-printed circuit board sensor based on this model is designed and fabricated. Open-loop characterization of the sensor to visual stimuli induced by self motion is performed. Closed-loop stabilizing feedback of the sensor in combination with optic flow sensors is implemented onboard a quadrotor micro-air vehicle and its impulse response is characterized.

  5. Towards a visual modeling approach to designing microelectromechanical system transducers

    Science.gov (United States)

    Dewey, Allen; Srinivasan, Vijay; Icoz, Evrim

    1999-12-01

    In this paper, we address initial design capture and system conceptualization of microelectromechanical system transducers based on visual modeling and design. Visual modeling frames the task of generating hardware description language (analog and digital) component models in a manner similar to the task of generating software programming language applications. A structured topological design strategy is employed, whereby microelectromechanical foundry cell libraries are utilized to facilitate the design process of exploring candidate cells (topologies), varying key aspects of the transduction for each topology, and determining which topology best satisfies design requirements. Coupled-energy microelectromechanical system characterizations at a circuit level of abstraction are presented that are based on branch constitutive relations and an overall system of simultaneous differential and algebraic equations. The resulting design methodology is called visual integrated-microelectromechanical VHDL-AMS interactive design (VHDL-AMS is visual hardware design language for analog and mixed signal).

  6. From Traffic Flow to Economic System

    Science.gov (United States)

    Bando, M.

    The optimal velocity model which is applied to traffic flow phenomena explains a spontaneous formation of traffic congestion. We discuss why the model works well in describing both free-flow and congested flow states in a unified way. The essential ingredient is that our model takes account of a sort of time delay in reacting to a given stimulus. This causes instability of many-body system, and yields a kind of phase transition above a certain critical density. Especially there appears a limit cycle on the phase space along which individual vehicle moves, and they show cyclic behavior. Once that we recognize the mechanism the same idea can be applied to a variety of phenomena which show cyclic behavior observed in many-body systems. As an example of such applications, we investigate business cycles commonly observed in economic system. We further discuss a possible origin of a kind of cyclic behavior observed in climate change.

  7. Quantitative evaluation of regional cerebral blood flow by visual stimulation in {sup 99m}Tc- HMPAO brain SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Juh, Ra Hyeong; Suh, Tae Suk; Kwark, Chul Eun; Choe, Bo Young; Lee, Hyoung Koo; Chung, Yong An; Kim, Sung Hoon; Chung, Soo Kyo [College of Medicine, The Catholic Univ. of Seoul, Seoul (Korea, Republic of)

    2002-06-01

    The purpose of this study is to investigate the effects of visual activation and quantitative analysis of regional cerebral blood flow. Visual activation was known to increase regional cerebral blood flow in the visual cortex in occipital lobe. We evaluated that change in the distribution of '9{sup 9m}Tc-HMPAO (Hexamethyl propylene amine oxime) to reflect in regional cerebral blood flow. The six volunteers were injected with 925 MBq (mean ages: 26.75 years, n=6, 3men, 3women) underwent MRI and {sup 99m}Tc-HMPAO SPECT during a rest state with closed eyes and visual stimulated with 8 Hz LED. We delineate the region of interest and calculated the mean count per voxel in each of the fifteen slices to quantitative analysis. The ROI to whole brain ratio and regional index was calculated pixel to pixel subtraction visual non-activation image from visual activation image and constructed brain map using a statistical parameter map(SPM99). The mean regional cerebral blood flow was increased due to visual stimulation. The increase rate of the mean regional cerebral blood flow which of the activation region in primary visual cortex of occipital lobe was 32.50{+-}5.67%. The significant activation sites using a statistical parameter of brain constructed a rendering image and image fusion with SPECT and MRI. Visual activation was revealed significant increase through quantitative analysis in visual cortex. Activation region was certified in Talairach coordinate and primary visual cortex (Ba17),visual association area (Ba18,19) of Brodmann.

  8. Quantitative evaluation of regional cerebral blood flow by visual stimulation in 99mTc-HMPAO brain SPECT

    International Nuclear Information System (INIS)

    Juh, R. H.; Suh, T. S.; Chung, Y. A.

    2002-01-01

    The purpose of this study is to investigate the effects of visual activation and quantitative analysis of regional cerebral blood flow. Visual activation was known to increase regional cerebral blood flow in the visual cortex in occipital lobe. We evaluated that change in the distribution of 99mTc-HMPAO (Hexamethyl propylene amine oxime) to reflect in regional cerebral blood flow. The six volunteers were injected with 925 MBq (mean ages: 26.75 years, n=6, 3men, 3women) underwent MRI and 99mTc- HMPAO SPECT during a rest state with closed eyes and visual stimulated with 8 Hz LED. We delineate the region of interest and calculated the mean count per voxel in each of the fifteen slices to quantitative analysis. The ROI to whole brain ratio and regional index was calculated pixel to pixel subtraction visual non-activation image from visual activation image and constructed brain map using a statistical parameter map (SPM99). The mean regional cerebral blood flow was increased due to visual stimulation. The increase rate of the mean regional cerebral blood flow which of the activation region in primary visual cortex of occipital lobe was 32.50±5.67%. The significant activation sites using a statistical parameter of brain constructed a rendering image and image fusion with SPECT and MRI. Visual activation was revealed significant increase through quantitative analysis in visual cortex. Activation region was certified in Talairach coordinate and primary visual cortex (Ba17),visual association area (Ba18,19) of Brodmann

  9. Quantitative evaluation of regional cerebral blood flow by visual stimulation in 99mTc- HMPAO brain SPECT

    International Nuclear Information System (INIS)

    Juh, Ra Hyeong; Suh, Tae Suk; Kwark, Chul Eun; Choe, Bo Young; Lee, Hyoung Koo; Chung, Yong An; Kim, Sung Hoon; Chung, Soo Kyo

    2002-01-01

    The purpose of this study is to investigate the effects of visual activation and quantitative analysis of regional cerebral blood flow. Visual activation was known to increase regional cerebral blood flow in the visual cortex in occipital lobe. We evaluated that change in the distribution of '9 9m Tc-HMPAO (Hexamethyl propylene amine oxime) to reflect in regional cerebral blood flow. The six volunteers were injected with 925 MBq (mean ages: 26.75 years, n=6, 3men, 3women) underwent MRI and 99m Tc-HMPAO SPECT during a rest state with closed eyes and visual stimulated with 8 Hz LED. We delineate the region of interest and calculated the mean count per voxel in each of the fifteen slices to quantitative analysis. The ROI to whole brain ratio and regional index was calculated pixel to pixel subtraction visual non-activation image from visual activation image and constructed brain map using a statistical parameter map(SPM99). The mean regional cerebral blood flow was increased due to visual stimulation. The increase rate of the mean regional cerebral blood flow which of the activation region in primary visual cortex of occipital lobe was 32.50±5.67%. The significant activation sites using a statistical parameter of brain constructed a rendering image and image fusion with SPECT and MRI. Visual activation was revealed significant increase through quantitative analysis in visual cortex. Activation region was certified in Talairach coordinate and primary visual cortex (Ba17),visual association area (Ba18,19) of Brodmann

  10. Quantitative evaluation of regional cerebral blood flow by visual stimulation in {sup 99m}Tc-HMPAO brain SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Juh, R. H.; Suh, T. S.; Chung, Y. A. [The Catholic Univ., of Korea, Seoul (Korea, Republic of)

    2002-07-01

    The purpose of this study is to investigate the effects of visual activation and quantitative analysis of regional cerebral blood flow. Visual activation was known to increase regional cerebral blood flow in the visual cortex in occipital lobe. We evaluated that change in the distribution of 99mTc-HMPAO (Hexamethyl propylene amine oxime) to reflect in regional cerebral blood flow. The six volunteers were injected with 925 MBq (mean ages: 26.75 years, n=6, 3men, 3women) underwent MRI and 99mTc- HMPAO SPECT during a rest state with closed eyes and visual stimulated with 8 Hz LED. We delineate the region of interest and calculated the mean count per voxel in each of the fifteen slices to quantitative analysis. The ROI to whole brain ratio and regional index was calculated pixel to pixel subtraction visual non-activation image from visual activation image and constructed brain map using a statistical parameter map (SPM99). The mean regional cerebral blood flow was increased due to visual stimulation. The increase rate of the mean regional cerebral blood flow which of the activation region in primary visual cortex of occipital lobe was 32.50{+-}5.67%. The significant activation sites using a statistical parameter of brain constructed a rendering image and image fusion with SPECT and MRI. Visual activation was revealed significant increase through quantitative analysis in visual cortex. Activation region was certified in Talairach coordinate and primary visual cortex (Ba17),visual association area (Ba18,19) of Brodmann.

  11. High-speed flow visualization in a pump-turbine under off-design operating conditions

    International Nuclear Information System (INIS)

    Hasmatuchi, V; Roth, S; Botero, F; Avellan, F; Farhat, M

    2010-01-01

    The flow hydrodynamics in a low specific speed radial pump-turbine reduced scale model is experimentally investigated under off-design operating conditions in generating mode. Wall pressure measurements, in the stator, synchronized with high-speed flow visualizations in the vaneless space between the impeller and the guide vanes using air bubbles injection are performed. When starting from the best efficiency point and increasing the runner speed, a significant increase of the pressure fluctuations is observed mainly in channels between wicket gates. The spectral analysis shows a rise of one stall cell, rotating with about 70% of the impeller frequency, at runaway, which further increases as the zero discharge condition is approached. Then a specific image processing technique is detailed and applied to create a synthetic instantaneous view of the flow pattern on the entire guide vanes circumference for an operating point in turbine-brake mode, where backflow and vortices accompany the stall passage.

  12. Advanced Supersonic Nozzle Concepts: Experimental Flow Visualization Results Paired With LES

    Science.gov (United States)

    Berry, Matthew; Magstadt, Andrew; Stack, Cory; Gaitonde, Datta; Glauser, Mark; Syracuse University Team; The Ohio State University Team

    2015-11-01

    Advanced supersonic nozzle concepts are currently under investigation, utilizing multiple bypass streams and airframe integration to bolster performance and efficiency. This work focuses on the parametric study of a supersonic, multi-stream jet with aft deck. The single plane of symmetry, rectangular nozzle, displays very complex and unique flow characteristics. Flow visualization techniques in the form of PIV and schlieren capture flow features at various deck lengths and Mach numbers. LES is compared to the experimental results to both validate the computational model and identify limitations of the simulation. By comparing experimental results to LES, this study will help create a foundation of knowledge for advanced nozzle designs in future aircraft. SBIR Phase II with Spectral Energies, LLC under direction of Barry Kiel.

  13. Visualization of thermal management system in space using neutron radiography

    International Nuclear Information System (INIS)

    Nakazawa, Takeshi

    1995-01-01

    The visualizing technique by neutron radiography is effective for visualizing liquid in metals, and the applications in wide fields have been reported. In this paper, as one of the examples of applying the visualizing technique by neutron radiography, the experiment of visualizing the two-phase fluid loop heat removal system for the purpose of using in spatial environment was carried out, and its results are reported. For future large scale space ships and space stations, the heat removal system with two-phase fluid loop which utilizes the phase transformation of heat transport media is regarded as promising. By this system, good heat transfer performance is obtained, transported heat quantity per unit mass of media increases, and pumping power and the weight of the total system are reduced. Temperature can be controlled by system pressure. The two-phase fluid loop for the visualization experiment and the experimental results are reported. By the experiment using the real time NRG system at the JRR-3M, the boiling and evaporation phenomena in the capillary heat transfer tubes were able to be visualized. (K.I.)

  14. Visualization Measurement of Streaming Flows Associated with a Single-Acoustic Levitator

    Science.gov (United States)

    Hasegawa, Koji; Abe, Yutaka; Kaneko, Akiko; Yamamoto, Yuji; Aoki, Kazuyoshi

    2009-08-01

    The purpose of the study is to experimentally investigate flow fields generated by an acoustic levitator. This flow field has been observed using flow visualization, PIV method. In the absent of a drop, the flow field was strongly influenced by sound pressure level (SPL). In light of the interfacial stability of a levitated drop, SPL was set at 161-163 [dB] in our experiments. In the case of any levitated drop at a pressure node of a standing wave, the toroidal vortices were appeared around a drop and clearly observed the flow fields around the drop by PIV measurement. It is found that the toroidal vortices around a levitated drop were strongly affected by the viscosity of a drop. For more detailed research, experiments in the reduced gravity were conducted with aircraft parabolic flights. By comparison with experimental results in the earth and reduced gravity, it is also indicated that the configuration of the external flow field around a drop is most likely to be affected by a position of a drop as well.

  15. Visualizing and measuring flow in shale matrix using in situ synchrotron X-ray microtomography

    Science.gov (United States)

    Kohli, A. H.; Kiss, A. M.; Kovscek, A. R.; Bargar, J.

    2017-12-01

    Natural gas production via hydraulic fracturing of shale has proliferated on a global scale, yet recovery factors remain low because production strategies are not based on the physics of flow in shale reservoirs. In particular, the physical mechanisms and time scales of depletion from the matrix into the simulated fracture network are not well understood, limiting the potential to optimize operations and reduce environmental impacts. Studying matrix flow is challenging because shale is heterogeneous and has porosity from the μm- to nm-scale. Characterizing nm-scale flow paths requires electron microscopy but the limited field of view does not capture the connectivity and heterogeneity observed at the mm-scale. Therefore, pore-scale models must link to larger volumes to simulate flow on the reservoir-scale. Upscaled models must honor the physics of flow, but at present there is a gap between cm-scale experiments and μm-scale simulations based on ex situ image data. To address this gap, we developed a synchrotron X-ray microscope with an in situ cell to simultaneously visualize and measure flow. We perform coupled flow and microtomography experiments on mm-scale samples from the Barnett, Eagle Ford and Marcellus reservoirs. We measure permeability at various pressures via the pulse-decay method to quantify effective stress dependence and the relative contributions of advective and diffusive mechanisms. Images at each pressure step document how microfractures, interparticle pores, and organic matter change with effective stress. Linking changes in the pore network to flow measurements motivates a physical model for depletion. To directly visualize flow, we measure imbibition rates using inert, high atomic number gases and image periodically with monochromatic beam. By imaging above/below X-ray adsorption edges, we magnify the signal of gas saturation in μm-scale porosity and nm-scale, sub-voxel features. Comparing vacuumed and saturated states yields image

  16. Dynamics of zonal flows in helical systems.

    Science.gov (United States)

    Sugama, H; Watanabe, T-H

    2005-03-25

    A theory for describing collisionless long-time behavior of zonal flows in helical systems is presented and its validity is verified by gyrokinetic-Vlasov simulation. It is shown that, under the influence of particles trapped in helical ripples, the response of zonal flows to a given source becomes weaker for lower radial wave numbers and deeper helical ripples while a high-level zonal-flow response, which is not affected by helical-ripple-trapped particles, can be maintained for a longer time by reducing their bounce-averaged radial drift velocity. This implies a possibility that helical configurations optimized for reducing neoclassical ripple transport can simultaneously enhance zonal flows which lower anomalous transport.

  17. Sunfall: a collaborative visual analytics system for astrophysics

    International Nuclear Information System (INIS)

    Aragon, C R; Bailey, S J; Poon, S; Runge, K; Thomas, R C

    2008-01-01

    Computational and experimental sciences produce and collect ever-larger and complex datasets, often in large-scale, multi-institution projects. The inability to gain insight into complex scientific phenomena using current software tools is a bottleneck facing virtually all endeavors of science. In this paper, we introduce Sunfall, a collaborative visual analytics system developed for the Nearby Supernova Factory, an international astrophysics experiment and the largest data volume supernova search currently in operation. Sunfall utilizes novel interactive visualization and analysis techniques to facilitate deeper scientific insight into complex, noisy, high-dimensional, high-volume, time-critical data. The system combines novel image processing algorithms, statistical analysis, and machine learning with highly interactive visual interfaces to enable collaborative, user-driven scientific exploration of supernova image and spectral data. Sunfall is currently in operation at the Nearby Supernova Factory; it is the first visual analytics system in production use at a major astrophysics project

  18. Sunfall: a collaborative visual analytics system for astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Aragon, Cecilia R.; Aragon, Cecilia R.; Bailey, Stephen J.; Poon, Sarah; Runge, Karl; Thomas, Rollin C.

    2008-07-07

    Computational and experimental sciences produce and collect ever-larger and complex datasets, often in large-scale, multi-institution projects. The inability to gain insight into complex scientific phenomena using current software tools is a bottleneck facing virtually all endeavors of science. In this paper, we introduce Sunfall, a collaborative visual analytics system developed for the Nearby Supernova Factory, an international astrophysics experiment and the largest data volume supernova search currently in operation. Sunfall utilizes novel interactive visualization and analysis techniques to facilitate deeper scientific insight into complex, noisy, high-dimensional, high-volume, time-critical data. The system combines novel image processing algorithms, statistical analysis, and machine learning with highly interactive visual interfaces to enable collaborative, user-driven scientific exploration of supernova image and spectral data. Sunfall is currently in operation at the Nearby Supernova Factory; it is the first visual analytics system in production use at a major astrophysics project.

  19. Sunfall: a collaborative visual analytics system for astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Aragon, C R; Bailey, S J; Poon, S; Runge, K; Thomas, R C [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)], E-mail: CRAragon@lbl.gov

    2008-07-15

    Computational and experimental sciences produce and collect ever-larger and complex datasets, often in large-scale, multi-institution projects. The inability to gain insight into complex scientific phenomena using current software tools is a bottleneck facing virtually all endeavors of science. In this paper, we introduce Sunfall, a collaborative visual analytics system developed for the Nearby Supernova Factory, an international astrophysics experiment and the largest data volume supernova search currently in operation. Sunfall utilizes novel interactive visualization and analysis techniques to facilitate deeper scientific insight into complex, noisy, high-dimensional, high-volume, time-critical data. The system combines novel image processing algorithms, statistical analysis, and machine learning with highly interactive visual interfaces to enable collaborative, user-driven scientific exploration of supernova image and spectral data. Sunfall is currently in operation at the Nearby Supernova Factory; it is the first visual analytics system in production use at a major astrophysics project.

  20. Rebalancing electrolytes in redox flow battery systems

    Science.gov (United States)

    Chang, On Kok; Pham, Ai Quoc

    2014-12-23

    Embodiments of redox flow battery rebalancing systems include a system for reacting an unbalanced flow battery electrolyte with a rebalance electrolyte in a first reaction cell. In some embodiments, the rebalance electrolyte may contain ferrous iron (Fe.sup.2+) which may be oxidized to ferric iron (Fe.sup.3+) in the first reaction cell. The reducing ability of the rebalance reactant may be restored in a second rebalance cell that is configured to reduce the ferric iron in the rebalance electrolyte back into ferrous iron through a reaction with metallic iron.

  1. Large-scale visualization system for grid environment

    International Nuclear Information System (INIS)

    Suzuki, Yoshio

    2007-01-01

    Center for Computational Science and E-systems of Japan Atomic Energy Agency (CCSE/JAEA) has been conducting R and Ds of distributed computing (grid computing) environments: Seamless Thinking Aid (STA), Information Technology Based Laboratory (ITBL) and Atomic Energy Grid InfraStructure (AEGIS). In these R and Ds, we have developed the visualization technology suitable for the distributed computing environment. As one of the visualization tools, we have developed the Parallel Support Toolkit (PST) which can execute the visualization process parallely on a computer. Now, we improve PST to be executable simultaneously on multiple heterogeneous computers using Seamless Thinking Aid Message Passing Interface (STAMPI). STAMPI, we have developed in these R and Ds, is the MPI library executable on a heterogeneous computing environment. The improvement realizes the visualization of extremely large-scale data and enables more efficient visualization processes in a distributed computing environment. (author)

  2. High resolution light-sheet based high-throughput imaging cytometry system enables visualization of intra-cellular organelles

    Science.gov (United States)

    Regmi, Raju; Mohan, Kavya; Mondal, Partha Pratim

    2014-09-01

    Visualization of intracellular organelles is achieved using a newly developed high throughput imaging cytometry system. This system interrogates the microfluidic channel using a sheet of light rather than the existing point-based scanning techniques. The advantages of the developed system are many, including, single-shot scanning of specimens flowing through the microfluidic channel at flow rate ranging from micro- to nano- lit./min. Moreover, this opens-up in-vivo imaging of sub-cellular structures and simultaneous cell counting in an imaging cytometry system. We recorded a maximum count of 2400 cells/min at a flow-rate of 700 nl/min, and simultaneous visualization of fluorescently-labeled mitochondrial network in HeLa cells during flow. The developed imaging cytometry system may find immediate application in biotechnology, fluorescence microscopy and nano-medicine.

  3. Modernized Approach for Generating Reproducible Heterogeneity Using Transmitted-Light for Flow Visualization Experiments

    Science.gov (United States)

    Jones, A. A.; Holt, R. M.

    2017-12-01

    Image capturing in flow experiments has been used for fluid mechanics research since the early 1970s. Interactions of fluid flow between the vadose zone and permanent water table are of great interest because this zone is responsible for all recharge waters, pollutant transport and irrigation efficiency for agriculture. Griffith, et al. (2011) developed an approach where constructed reproducible "geologically realistic" sand configurations are deposited in sandfilled experimental chambers for light-transmitted flow visualization experiments. This method creates reproducible, reverse graded, layered (stratified) thin-slab sand chambers for point source experiments visualizing multiphase flow through porous media. Reverse-graded stratification of sand chambers mimic many naturally occurring sedimentary deposits. Sandfilled chambers use light as nonintrusive tools for measuring water saturation in two-dimensions (2-D). Homogeneous and heterogeneous sand configurations can be produced to visualize the complex physics of the unsaturated zone. The experimental procedure developed by Griffith, et al. (2011) was designed using now outdated and obsolete equipment. We have modernized this approach with new Parker Deadel linear actuator and programed projects/code for multiple configurations. We have also updated the Roper CCD software and image processing software with the latest in industry standards. Modernization of transmitted-light source, robotic equipment, redesigned experimental chambers, and newly developed analytical procedures have greatly reduced time and cost per experiment. We have verified the ability of the new equipment to generate reproducible heterogeneous sand-filled chambers and demonstrated the functionality of the new equipment and procedures by reproducing several gravity-driven fingering experiments conducted by Griffith (2008).

  4. Visualization test facility of nuclear fuel rod emergency cooling system

    International Nuclear Information System (INIS)

    Candido, Marcos Antonio; Mesquita, Amir Zacarias; Rezende, Hugo Cesar; Santos, Andre Augusto Campagnole

    2013-01-01

    The nuclear reactors safety is determined according to their protection against the consequences that may result from postulated accidents. The Loss of Coolant Accident (LOCA) is one the most important design basis accidents (DBA). The failure may be due to rupture of the primary loop piping. Another accident postulated is due to lack of power in the pump motors in the primary circuit. In both cases the reactor shut down automatically due to the decrease of reactivity to maintain the fissions, and to the drop of control rods. In the event of an accident it is necessary to maintain the coolant flow to remove the fuel elements residual heat, which remains after shut down. This heat is a significant amount of the maximum thermal power generated in normal operation (about 7%). Recently this event has been quite prominent in the press due to the reactor accident in Fukushima nuclear power station. This paper presents the experimental facility under rebuilding at the Thermal Hydraulic Laboratory of the Nuclear Technology Development Center (CDTN) that has the objective of monitoring and visualization of the process of emergency cooling of a nuclear fuel rod simulator, heated by Joule effect. The system will help the comprehension of the heat transfer process during reflooding after a loss of coolant accident in the fuel of light water reactor core. (author)

  5. Human visual system automatically encodes sequential regularities of discrete events.

    Science.gov (United States)

    Kimura, Motohiro; Schröger, Erich; Czigler, István; Ohira, Hideki

    2010-06-01

    For our adaptive behavior in a dynamically changing environment, an essential task of the brain is to automatically encode sequential regularities inherent in the environment into a memory representation. Recent studies in neuroscience have suggested that sequential regularities embedded in discrete sensory events are automatically encoded into a memory representation at the level of the sensory system. This notion is largely supported by evidence from investigations using auditory mismatch negativity (auditory MMN), an event-related brain potential (ERP) correlate of an automatic memory-mismatch process in the auditory sensory system. However, it is still largely unclear whether or not this notion can be generalized to other sensory modalities. The purpose of the present study was to investigate the contribution of the visual sensory system to the automatic encoding of sequential regularities using visual mismatch negativity (visual MMN), an ERP correlate of an automatic memory-mismatch process in the visual sensory system. To this end, we conducted a sequential analysis of visual MMN in an oddball sequence consisting of infrequent deviant and frequent standard stimuli, and tested whether the underlying memory representation of visual MMN generation contains only a sensory memory trace of standard stimuli (trace-mismatch hypothesis) or whether it also contains sequential regularities extracted from the repetitive standard sequence (regularity-violation hypothesis). The results showed that visual MMN was elicited by first deviant (deviant stimuli following at least one standard stimulus), second deviant (deviant stimuli immediately following first deviant), and first standard (standard stimuli immediately following first deviant), but not by second standard (standard stimuli immediately following first standard). These results are consistent with the regularity-violation hypothesis, suggesting that the visual sensory system automatically encodes sequential

  6. Application of fast neutron radiography to three-dimensional visualization of steady two-phase flow in a rod bundle

    CERN Document Server

    Takenaka, N; Fujii, T; Mizubata, M; Yoshii, K

    1999-01-01

    Three-dimensional void fraction distribution of air-water two-phase flow in a 4x4 rod-bundle near a spacer was visualized by fast neutron radiography using a CT method. One-dimensional cross sectional averaged void fraction distribution was also calculated. The behaviors of low void fraction (thick water) two-phase flow in the rod bundle around the spacer were clearly visualized. It was shown that the void fraction distributions were visualized with a quality similar to those by thermal neutron radiography for low void fraction two-phase flow which is difficult to visualize by thermal neutron radiography. It is concluded that the fast neutron radiography is efficiently applicable to two-phase flow studies.

  7. Interactive visual steering--rapid visual prototyping of a common rail injection system.

    Science.gov (United States)

    Matković, Kresimir; Gracanin, Denis; Jelović, Mario; Hauser, Helwig

    2008-01-01

    Interactive steering with visualization has been a common goal of the visualization research community for twenty years, but it is rarely ever realized in practice. In this paper we describe a successful realization of a tightly coupled steering loop, integrating new simulation technology and interactive visual analysis in a prototyping environment for automotive industry system design. Due to increasing pressure on car manufacturers to meet new emission regulations, to improve efficiency, and to reduce noise, both simulation and visualization are pushed to their limits. Automotive system components, such as the powertrain system or the injection system have an increasing number of parameters, and new design approaches are required. It is no longer possible to optimize such a system solely based on experience or forward optimization. By coupling interactive visualization with the simulation back-end (computational steering), it is now possible to quickly prototype a new system, starting from a non-optimized initial prototype and the corresponding simulation model. The prototyping continues through the refinement of the simulation model, of the simulation parameters and through trial-and-error attempts to an optimized solution. The ability to early see the first results from a multidimensional simulation space--thousands of simulations are run for a multidimensional variety of input parameters--and to quickly go back into the simulation and request more runs in particular parameter regions of interest significantly improves the prototyping process and provides a deeper understanding of the system behavior. The excellent results which we achieved for the common rail injection system strongly suggest that our approach has a great potential of being generalized to other, similar scenarios.

  8. The Two Visual Systems Hypothesis: new challenges and insights from visual form agnosic patient DF

    Directory of Open Access Journals (Sweden)

    Robert Leslie Whitwell

    2014-12-01

    Full Text Available Patient DF, who developed visual form agnosia following carbon monoxide poisoning, is still able to use vision to adjust the configuration of her grasping hand to the geometry of a goal object. This striking dissociation between perception and action in DF provided a key piece of evidence for the formulation of Goodale and Milner’s Two Visual Systems Hypothesis (TVSH. According to the TVSH, the ventral stream plays a critical role in constructing our visual percepts, whereas the dorsal stream mediates the visual control of action, such as visually guided grasping. In this review, we discuss recent studies of DF that provide new insights into the functional organization of the dorsal and ventral streams. We confirm recent evidence that DF has dorsal as well as ventral brain damage – and that her dorsal-stream lesions and surrounding atrophy have increased in size since her first published brain scan. We argue that the damage to DF’s dorsal stream explains her deficits in directing actions at targets in the periphery. We then focus on DF’s ability to accurately adjust her in-flight hand aperture to changes in the width of goal objects (grip scaling whose dimensions she cannot explicitly report. An examination of several studies of DF’s grip scaling under natural conditions reveals a modest though significant deficit. Importantly, however, she continues to show a robust dissociation between form vision for perception and form vision for action. We also review recent studies that explore the role of online visual feedback and terminal haptic feedback in the programming and control of her grasping. These studies make it clear that DF is no more reliant on visual or haptic feedback than are neurologically-intact individuals. In short, we argue that her ability to grasp objects depends on visual feedforward processing carried out by visuomotor networks in her dorsal stream that function in the much the same way as they do in neurologically

  9. Shared visual attention and memory systems in the Drosophila brain.

    Directory of Open Access Journals (Sweden)

    Bruno van Swinderen

    Full Text Available BACKGROUND: Selective attention and memory seem to be related in human experience. This appears to be the case as well in simple model organisms such as the fly Drosophila melanogaster. Mutations affecting olfactory and visual memory formation in Drosophila, such as in dunce and rutabaga, also affect short-term visual processes relevant to selective attention. In particular, increased optomotor responsiveness appears to be predictive of visual attention defects in these mutants. METHODOLOGY/PRINCIPAL FINDINGS: To further explore the possible overlap between memory and visual attention systems in the fly brain, we screened a panel of 36 olfactory long term memory (LTM mutants for visual attention-like defects using an optomotor maze paradigm. Three of these mutants yielded high dunce-like optomotor responsiveness. We characterized these three strains by examining their visual distraction in the maze, their visual learning capabilities, and their brain activity responses to visual novelty. We found that one of these mutants, D0067, was almost completely identical to dunce(1 for all measures, while another, D0264, was more like wild type. Exploiting the fact that the LTM mutants are also Gal4 enhancer traps, we explored the sufficiency for the cells subserved by these elements to rescue dunce attention defects and found overlap at the level of the mushroom bodies. Finally, we demonstrate that control of synaptic function in these Gal4 expressing cells specifically modulates a 20-30 Hz local field potential associated with attention-like effects in the fly brain. CONCLUSIONS/SIGNIFICANCE: Our study uncovers genetic and neuroanatomical systems in the fly brain affecting both visual attention and odor memory phenotypes. A common component to these systems appears to be the mushroom bodies, brain structures which have been traditionally associated with odor learning but which we propose might be also involved in generating oscillatory brain activity

  10. Anatomy and physiology of the afferent visual system.

    Science.gov (United States)

    Prasad, Sashank; Galetta, Steven L

    2011-01-01

    The efficient organization of the human afferent visual system meets enormous computational challenges. Once visual information is received by the eye, the signal is relayed by the retina, optic nerve, chiasm, tracts, lateral geniculate nucleus, and optic radiations to the striate cortex and extrastriate association cortices for final visual processing. At each stage, the functional organization of these circuits is derived from their anatomical and structural relationships. In the retina, photoreceptors convert photons of light to an electrochemical signal that is relayed to retinal ganglion cells. Ganglion cell axons course through the optic nerve, and their partial decussation in the chiasm brings together corresponding inputs from each eye. Some inputs follow pathways to mediate pupil light reflexes and circadian rhythms. However, the majority of inputs arrive at the lateral geniculate nucleus, which relays visual information via second-order neurons that course through the optic radiations to arrive in striate cortex. Feedback mechanisms from higher cortical areas shape the neuronal responses in early visual areas, supporting coherent visual perception. Detailed knowledge of the anatomy of the afferent visual system, in combination with skilled examination, allows precise localization of neuropathological processes and guides effective diagnosis and management of neuro-ophthalmic disorders. Copyright © 2011 Elsevier B.V. All rights reserved.

  11. Defining the cortical visual systems: "what", "where", and "how"

    Science.gov (United States)

    Creem, S. H.; Proffitt, D. R.; Kaiser, M. K. (Principal Investigator)

    2001-01-01

    The visual system historically has been defined as consisting of at least two broad subsystems subserving object and spatial vision. These visual processing streams have been organized both structurally as two distinct pathways in the brain, and functionally for the types of tasks that they mediate. The classic definition by Ungerleider and Mishkin labeled a ventral "what" stream to process object information and a dorsal "where" stream to process spatial information. More recently, Goodale and Milner redefined the two visual systems with a focus on the different ways in which visual information is transformed for different goals. They relabeled the dorsal stream as a "how" system for transforming visual information using an egocentric frame of reference in preparation for direct action. This paper reviews recent research from psychophysics, neurophysiology, neuropsychology and neuroimaging to define the roles of the ventral and dorsal visual processing streams. We discuss a possible solution that allows for both "where" and "how" systems that are functionally and structurally organized within the posterior parietal lobe.

  12. Visual color matching system based on RGB LED light source

    Science.gov (United States)

    Sun, Lei; Huang, Qingmei; Feng, Chen; Li, Wei; Wang, Chaofeng

    2018-01-01

    In order to study the property and performance of LED as RGB primary color light sources on color mixture in visual psychophysical experiments, and to find out the difference between LED light source and traditional light source, a visual color matching experiment system based on LED light sources as RGB primary colors has been built. By simulating traditional experiment of metameric color matching in CIE 1931 RGB color system, it can be used for visual color matching experiments to obtain a set of the spectral tristimulus values which we often call color-matching functions (CMFs). This system consists of three parts: a monochromatic light part using blazed grating, a light mixing part where the summation of 3 LED illuminations are to be visually matched with a monochromatic illumination, and a visual observation part. The three narrow band LEDs used have dominant wavelengths of 640 nm (red), 522 nm (green) and 458 nm (blue) respectively and their intensities can be controlled independently. After the calibration of wavelength and luminance of LED sources with a spectrophotometer, a series of visual color matching experiments have been carried out by 5 observers. The results are compared with those from CIE 1931 RGB color system, and have been used to compute an average locus for the spectral colors in the color triangle, with white at the center. It has been shown that the use of LED is feasible and has the advantages of easy control, good stability and low cost.

  13. Google-Earth Based Visualizations for Environmental Flows and Pollutant Dispersion in Urban Areas

    Directory of Open Access Journals (Sweden)

    Daoming Liu

    2017-03-01

    Full Text Available In the present study, we address the development and application of an efficient tool for conversion of results obtained by an integrated computational fluid dynamics (CFD and computational reaction dynamics (CRD approach and their visualization in the Google Earth. We focus on results typical for environmental fluid mechanics studies at a city scale that include characteristic wind flow patterns and dispersion of reactive scalars. This is achieved by developing a code based on the Java language, which converts the typical four-dimensional structure (spatial and temporal dependency of data results in the Keyhole Markup Language (KML format. The visualization techniques most often used are revisited and implemented into the conversion tool. The potential of the tool is demonstrated in a case study of smog formation due to an intense traffic emission in Rotterdam (The Netherlands. It is shown that the Google Earth can provide a computationally efficient and user-friendly means of data representation. This feature can be very useful for visualization of pollution at street levels, which is of great importance for the city residents. Various meteorological and traffic emissions can be easily visualized and analyzed, providing a powerful, user-friendly tool for traffic regulations and urban climate adaptations.

  14. The Visualization of the flow field Using Lidar's Range Detection and Digital Image Correlation

    International Nuclear Information System (INIS)

    Park, Nak-Gyu; Baik, Seung-Hoon; Park, Seung-Kyu; Kim, Dong-lyul; Ahn, Yong-Jin

    2015-01-01

    In this paper however we focused on flow velocity, visualization measurement. Using cameras one is able to collect large amount of spatial flow structure data in a very short time. Image data is further processed to determine velocity fields and other flow properties. Therefore, we tried to find a way to measure change of image and to apply it to the lidar technique, which is a powerful technique in the field of climate study and we have an interest in the digital image correlation (DIC). Among the DIC algorithms, the sum of squared differences (SSD) method is a way to track the sub-set image in different images. We used this algorithm for tracking the same point in different moving smoke images. For the lidar system, we used an injection seeded pulsed Nd:YAG laser as the transmitter and an photon multiplier tube (PMT) as the laser light sensor to measure the distance to the target clouds. We used the DIC system to track the smoke image and calculate the actual displacement per unit time. The configured lidar system acquired the lidar signal of smoke at a distance of about 150m. The developed fast correlation algorithm of the DIC, which is used to track the fast moving smoke relatively, was efficient to measure the smoke velocity in real time

  15. Visualization of Flow Field of Weis-Fogh Type Water Turbine Using the PIV

    Energy Technology Data Exchange (ETDEWEB)

    Ro, Ki Deok [Gyeongsang Nat’l Univ., Jinju (Korea, Republic of)

    2017-03-15

    In this study, the visualization of the unsteady flow field of a Weis-Fogh-type water turbine was investigated using particle-image velocimetry. The visualization experiments were performed in a parameter range that provided relatively high-efficiency wing conditions, that is, at a wing opening angle α= 40 .deg. and at a velocity ratio of the uniform flow to the moving wing U/V = 1.5~2.5. The flow fields at the opening, translational, and closing stages were investigated for each experimental parameter. In the opening stage, the fluid was drawn in between the wing and wall at a velocity that increased with an increase in the opening angle and velocity ratio. In the translational stage, the fluid on the pressure face of the wing moved in the direction of the wing motion, and the boundary layer at the back face of the wing was the thinnest and had a velocity ratio of 2.0. In the closing stage, the fluid between the wing and wall was jetted at a velocity that increased as the opening angle decreased; however, the velocity was independent of the velocity ratio.

  16. Visualization and evaluation of flow during water filtration: Parameterization and sensitivity analysis

    Directory of Open Access Journals (Sweden)

    Bílek Petr

    2016-01-01

    Full Text Available This paper deals with visualization and evaluation of flow during filtration of water seeded by artificial microscopic particles. Planar laser induced fluorescence (PLIF is a wide spread method for visualization and non-invasive characterization of flow. However the method uses fluorescent dyes or fluorescent particles in special cases. In this article the flow is seeded by non-fluorescent monodisperse polystyrene particles with the diameter smaller than one micrometer. The monodisperse sub-micron particles are very suitable for testing of textile filtration materials. Nevertheless non-fluorescent particles are not useful for PLIF method. A water filtration setup with an optical access to the place, were a tested filter is mounted, was built and used for the experiments. Concentration of particles in front of and behind the tested filter in a laser light sheet measured is and the local filtration efficiency expressed is. The article describes further progress in the measurement. It was carried out sensitivity analysis, parameterization and performance of the method during several simulations and experiments.

  17. UV reactor flow visualization and mixing quantification using three-dimensional laser-induced fluorescence.

    Science.gov (United States)

    Gandhi, Varun; Roberts, Philip J W; Stoesser, Thorsten; Wright, Harold; Kim, Jae-Hong

    2011-07-01

    Three-dimensional laser-induced fluorescence (3DLIF) was applied to visualize and quantitatively analyze mixing in a lab-scale UV reactor consisting of one lamp sleeve placed perpendicular to flow. The recirculation zone and the von Karman vortex shedding that commonly occur in flows around bluff bodies were successfully visualized. Multiple flow paths were analyzed by injecting the dye at various heights with respect to the lamp sleeve. A major difference in these pathways was the amount of dye that traveled close to the sleeve, i.e., a zone of higher residence time and higher UV exposure. Paths away from the center height had higher velocities and hence minimal influence by the presence of sleeve. Approach length was also characterized in order to increase the probability of microbes entering the region around the UV lamp. The 3DLIF technique developed in this study is expected to provide new insight on UV dose delivery useful for the design and optimization of UV reactors. Copyright © 2011 Elsevier Ltd. All rights reserved.

  18. Modelling and control of systems with flow

    NARCIS (Netherlands)

    van Mourik, S.

    2008-01-01

    In practice, feedback control design consists of three steps: modelling, model reduction and controller design for the reduced model. Systems with flow are often complicated, and there is yet no standard algorithm that integrates these steps. In this thesis we make a modest effort by considering two

  19. Experimental Visualization of the Flow Structure for Jet in Crossflow with a Curved Hole Passage

    Directory of Open Access Journals (Sweden)

    Jun Yu Liang

    2012-01-01

    Full Text Available The objective of this paper is to investigate the influence of a hole curvature on the flow structure and characteristics downstream of JICF (jet in cross-Flow by means of smoke visualization and particle image velocimetry (PIV. The experiment was performed in a low speed wind tunnel with Reynolds numbers of about 480 and 1000, based on the hole diameter and main flow speed. Two geometries were tested: a circular hole with 90° curvature and a circular straight hole for comparison, under blowing ratios 0.5 and 1.0. The measurements were done in the symmetric plane and four cross-sections. The results show that the curved hole could decrease the mixing behavior of jet flow with the main flow as the hole leading edge also increases the chance of transportingthecoolant to the wall surface and the transverse coverage. The curved hole shows a high potential to increase the cooling effectiveness once it is applied to the turbine blades.

  20. Psychophysical research progress of interocular suppression in amblyopic visual system

    OpenAIRE

    Jing-Jing Li; Yi Huang

    2016-01-01

    Some recent animal experiments and psychophysical studies indicate that patients with amblyopia have a structurally intact binocular visual system that is rendered functionally monocular due to suppression, and interocular suppression is a key mechanism in visual deficits experienced by patients with amblyopia. The aim of this review is to provide an overview of recent psychophysical findings that have investigated the important role of interocular suppression in amblyopia, the measurement an...

  1. A study of natural circulation cooling using a flow visualization rig

    International Nuclear Information System (INIS)

    Bowman, W.C.; Ferch, R.L.; Omar, A.M.

    1985-01-01

    A flow visualization rig has been built at Monserco Limited to provide visual insight into the thermalhydraulic phenomena which occur during single phase and two phase thermosyphoning in a figure-of-eight heat transport loop. Tests performed with the rig have provided design information for the scaling and instrumentation of a high pressure rig being investigated for simulating CANDU reactor conditions during natural circulation cooling. A videotape was produced, for viewing at this presentation, to show important thermalhydraulic features of the thermosyphoning process. The rig is a standard figure-of-eight loop with two steam generators and three heated channels per pass. An elevated surge tank open to atmosphere was used for pressure control. Two variable speed pumps provided forced circulation for warming up the rig, and for establishing the desired initial conditions for testing. Test rig power could be varied between 0 and 15 kW

  2. COMBINING INDEPENDENT VISUALIZATION AND TRACKING SYSTEMS FOR AUGMENTED REALITY

    Directory of Open Access Journals (Sweden)

    P. Hübner

    2018-05-01

    Full Text Available The basic requirement for the successful deployment of a mobile augmented reality application is a reliable tracking system with high accuracy. Recently, a helmet-based inside-out tracking system which meets this demand has been proposed for self-localization in buildings. To realize an augmented reality application based on this tracking system, a display has to be added for visualization purposes. Therefore, the relative pose of this visualization platform with respect to the helmet has to be tracked. In the case of hand-held visualization platforms like smartphones or tablets, this can be achieved by means of image-based tracking methods like marker-based or model-based tracking. In this paper, we present two marker-based methods for tracking the relative pose between the helmet-based tracking system and a tablet-based visualization system. Both methods were implemented and comparatively evaluated in terms of tracking accuracy. Our results show that mobile inside-out tracking systems without integrated displays can easily be supplemented with a hand-held tablet as visualization device for augmented reality purposes.

  3. Parameter Identification and Uncertainty Analysis for Visual MODFLOW based Groundwater Flow Model in a Small River Basin, Eastern India

    Science.gov (United States)

    Jena, S.

    2015-12-01

    The overexploitation of groundwater resulted in abandoning many shallow tube wells in the river Basin in Eastern India. For the sustainability of groundwater resources, basin-scale modelling of groundwater flow is essential for the efficient planning and management of the water resources. The main intent of this study is to develope a 3-D groundwater flow model of the study basin using the Visual MODFLOW package and successfully calibrate and validate it using 17 years of observed data. The sensitivity analysis was carried out to quantify the susceptibility of aquifer system to the river bank seepage, recharge from rainfall and agriculture practices, horizontal and vertical hydraulic conductivities, and specific yield. To quantify the impact of parameter uncertainties, Sequential Uncertainty Fitting Algorithm (SUFI-2) and Markov chain Monte Carlo (MCMC) techniques were implemented. Results from the two techniques were compared and the advantages and disadvantages were analysed. Nash-Sutcliffe coefficient (NSE) and coefficient of determination (R2) were adopted as two criteria during calibration and validation of the developed model. NSE and R2 values of groundwater flow model for calibration and validation periods were in acceptable range. Also, the MCMC technique was able to provide more reasonable results than SUFI-2. The calibrated and validated model will be useful to identify the aquifer properties, analyse the groundwater flow dynamics and the change in groundwater levels in future forecasts.

  4. Stereoscopy and the Human Visual System

    Science.gov (United States)

    Banks, Martin S.; Read, Jenny C. A.; Allison, Robert S.; Watt, Simon J.

    2012-01-01

    Stereoscopic displays have become important for many applications, including operation of remote devices, medical imaging, surgery, scientific visualization, and computer-assisted design. But the most significant and exciting development is the incorporation of stereo technology into entertainment: specifically, cinema, television, and video games. In these applications for stereo, three-dimensional (3D) imagery should create a faithful impression of the 3D structure of the scene being portrayed. In addition, the viewer should be comfortable and not leave the experience with eye fatigue or a headache. Finally, the presentation of the stereo images should not create temporal artifacts like flicker or motion judder. This paper reviews current research on stereo human vision and how it informs us about how best to create and present stereo 3D imagery. The paper is divided into four parts: (1) getting the geometry right, (2) depth cue interactions in stereo 3D media, (3) focusing and fixating on stereo images, and (4) how temporal presentation protocols affect flicker, motion artifacts, and depth distortion. PMID:23144596

  5. Matching-index-of-refraction of transparent 3D printing models for flow visualization

    Energy Technology Data Exchange (ETDEWEB)

    Song, Min Seop; Choi, Hae Yoon; Seong, Jee Hyun; Kim, Eung Soo, E-mail: kes7741@snu.ac.kr

    2015-04-01

    Matching-index-of-refraction (MIR) has been used for obtaining high-quality flow visualization data for the fundamental nuclear thermal-hydraulic researches. By this method, distortions of the optical measurements such as PIV and LDV have been successfully minimized using various combinations of the model materials and the working fluids. This study investigated a novel 3D printing technology for manufacturing models and an oil-based working fluid for matching the refractive indices. Transparent test samples were fabricated by various rapid prototyping methods including selective layer sintering (SLS), stereolithography (SLA), and vacuum casting. As a result, the SLA direct 3D printing was evaluated to be the most suitable for flow visualization considering manufacturability, transparency, and refractive index. In order to match the refractive indices of the 3D printing models, a working fluid was developed based on the mixture of herb essential oils, which exhibit high refractive index, high transparency, high density, low viscosity, low toxicity, and low price. The refractive index and viscosity of the working fluid range 1.453–1.555 and 2.37–6.94 cP, respectively. In order to validate the MIR method, a simple test using a twisted prism made by the SLA technique and the oil mixture (anise and light mineral oil) was conducted. The experimental results show that the MIR can be successfully achieved at the refractive index of 1.51, and the proposed MIR method is expected to be widely used for flow visualization studies and CFD validation for the nuclear thermal-hydraulic researches.

  6. Matching-index-of-refraction of transparent 3D printing models for flow visualization

    International Nuclear Information System (INIS)

    Song, Min Seop; Choi, Hae Yoon; Seong, Jee Hyun; Kim, Eung Soo

    2015-01-01

    Matching-index-of-refraction (MIR) has been used for obtaining high-quality flow visualization data for the fundamental nuclear thermal-hydraulic researches. By this method, distortions of the optical measurements such as PIV and LDV have been successfully minimized using various combinations of the model materials and the working fluids. This study investigated a novel 3D printing technology for manufacturing models and an oil-based working fluid for matching the refractive indices. Transparent test samples were fabricated by various rapid prototyping methods including selective layer sintering (SLS), stereolithography (SLA), and vacuum casting. As a result, the SLA direct 3D printing was evaluated to be the most suitable for flow visualization considering manufacturability, transparency, and refractive index. In order to match the refractive indices of the 3D printing models, a working fluid was developed based on the mixture of herb essential oils, which exhibit high refractive index, high transparency, high density, low viscosity, low toxicity, and low price. The refractive index and viscosity of the working fluid range 1.453–1.555 and 2.37–6.94 cP, respectively. In order to validate the MIR method, a simple test using a twisted prism made by the SLA technique and the oil mixture (anise and light mineral oil) was conducted. The experimental results show that the MIR can be successfully achieved at the refractive index of 1.51, and the proposed MIR method is expected to be widely used for flow visualization studies and CFD validation for the nuclear thermal-hydraulic researches

  7. Visualized Evaluation of Blood Flow to the Gastric Conduit and Complications in Esophageal Reconstruction.

    Science.gov (United States)

    Noma, Kazuhiro; Shirakawa, Yasuhiro; Kanaya, Nobuhiko; Okada, Tsuyoshi; Maeda, Naoaki; Ninomiya, Takayuki; Tanabe, Shunsuke; Sakurama, Kazufumi; Fujiwara, Toshiyoshi

    2018-03-01

    Evaluation of the blood supply to gastric conduits is critically important to avoid complications after esophagectomy. We began visual evaluation of blood flow using indocyanine green (ICG) fluorescent imaging in July 2015, to reduce reconstructive complications. In this study, we aimed to statistically verify the efficacy of blood flow evaluation using our simplified ICG method. A total of 285 consecutive patients who underwent esophagectomy and gastric conduit reconstruction were reviewed and divided into 2 groups: before and after introduction of ICG evaluation. The entire cohort and 68 patient pairs after propensity score matching (PS-M) were evaluated for clinical outcomes and the effect of visualized evaluation on reducing the risk of complication. The leakage rate in the ICG group was significantly lower than in the non-ICG group for each severity grade, both in the entire cohort (285 subjects) and after PS-M; the rates of other major complications, including recurrent laryngeal nerve palsy and pneumonia, were not different. The duration of postoperative ICU stay was approximately 1 day shorter in the ICG group than in the non-ICG group in the entire cohort, and approximately 2 days shorter after PS-M. Visualized evaluation of blood flow with ICG methods significantly reduced the rate of anastomotic complications of all Clavien-Dindo (CD) grades. Odds ratios for ICG evaluation decreased with CD grade (0.3419 for CD ≥ 1; 0.241 for CD ≥ 2; and 0.2153 for CD ≥ 3). Objective evaluation of blood supply to the reconstructed conduit using ICG fluorescent imaging reduces the risk and degree of anastomotic complication. Copyright © 2017 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

  8. Visualization of Atomization Gas Flow and Melt Break-up Effects in Response to Nozzle Design

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Iver; Rieken, Joel; Meyer, John; Byrd, David; Heidloff, Andy

    2011-04-01

    Both powder particle size control and efficient use of gas flow energy are highly prized goals for gas atomization of metal and alloy powder to minimize off-size powder inventory (or 'reverb') and excessive gas consumption. Recent progress in the design of close-coupled gas atomization nozzles and the water model simulation of melt feed tubes were coupled with previous results from several types of gas flow characterization methods, e.g., aspiration measurements and gas flow visualization, to make progress toward these goals. Size distribution analysis and high speed video recordings of gas atomization reaction synthesis (GARS) experiments on special ferritic stainless steel alloy powders with an Ar+O{sub 2} gas mixture were performed to investigate the operating mechanisms and possible advantages of several melt flow tube modifications with one specific gas atomization nozzle. In this study, close-coupled gas atomization under closed wake gas flow conditions was demonstrated to produce large yields of ultrafine (dia.<20 {mu}m) powders (up to 32%) with moderate standard deviations (1.62 to 1.99). The increased yield of fine powders is consistent with the dual atomization mechanisms of closed wake gas flow patterns in the near-field of the melt orifice. Enhanced size control by stabilized pre-filming of the melt with a slotted trumpet bell pour tube was not clearly demonstrated in the current experiments, perhaps confounded by the influence of the melt oxidation reaction that occurred simultaneously with the atomization process. For this GARS variation of close-coupled gas atomization, it may be best to utilize the straight cylindrical pour tube and closed wake operation of an atomization nozzle with higher gas mass flow to promote the maximum yields of ultrafine powders that are preferred for the oxide dispersion strengthened alloys made from these powders.

  9. Visualization of Natural Convection Heat Transfer on a Single Sphere using the Electroplating System

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dong Young; Chung, Bum Jin [Kyunghee University, Yongin (Korea, Republic of)

    2016-05-15

    The natural convective flows on outer sphere rise along surface. At top of sphere, the flows are lifted-up plume shape. For laminar flows, the local heat transfer shows maximum at the bottom of sphere and a monotonic decreases as flows approached to the top. The laminar natural convection heat transfer on a single sphere has been studied experimentally and numerically by several researchers. However, relatively less study has been performed for turbulent flows as it requires large facilities to achieve high Rayleigh numbers. The flows, which occur transition, is hard to experiment because of unstable. This study tried measurement of heat transfer and visualization external natural convection on a single sphere. The basic idea is that the plating patterns of copper on the sphere in mass transfer system will reveal the amount of heat transfer according to angular distance from the bottom. This study simulated natural convection on a single sphere and performed a mass transfer experiment using heat and mass transfer analogy concept. For visualization experiment, streak form plating pattern was observed. In this case, it seems that turbulence sets on the top of sphere and increases local heat transfer.

  10. Visualization and natural control systems for microscopy

    DEFF Research Database (Denmark)

    Taylor, Russell M.; Borland, David; Brooks, Frederick P.

    2005-01-01

    This chapter presents these microscope systems, along with brief descriptions of the science experiments driving the development of each system. Beginning with a discussion of the philosophy that has driven the Nanoscale Science Research Group (NSRG) and the methods used, the chapter describes th...

  11. Visual Cues for an Adaptive Expert System.

    Science.gov (United States)

    Miller, Helen B.

    NCR (National Cash Register) Corporation is pursuing opportunities to make their point of sale (POS) terminals easy to use and easy to learn. To approach the goal of making the technology invisible to the user, NCR has developed an adaptive expert prototype system for a department store POS operation. The structure for the adaptive system, the…

  12. Hummingbirds generate bilateral vortex loops during hovering: evidence from flow visualization

    Science.gov (United States)

    Pournazeri, Sam; Segre, Paolo S.; Princevac, Marko; Altshuler, Douglas L.

    2013-01-01

    Visualization of the vortex wake of a flying animal provides understanding of how wingbeat kinematics are translated into the aerodynamic forces for powering and controlling flight. Two general vortex flow patterns have been proposed for the wake of hovering hummingbirds: (1) The two wings form a single, merged vortex ring during each wing stroke; and (2) the two wings form bilateral vortex loops during each wing stroke. The second pattern was proposed after a study with particle image velocimetry that demonstrated bilateral source flows in a horizontal measurement plane underneath hovering Anna's hummingbirds ( Calypte anna). Proof of this hypothesis requires a clear perspective of bilateral pairs of vortices. Here, we used high-speed image sequences (500 frames per second) of C. anna hover feeding within a white plume to visualize the vortex wake from multiple perspectives. The films revealed two key structural features: (1) Two distinct jets of downwards airflow are present under each wing; and (2) vortex loops around each jet are shed during each upstroke and downstroke. To aid in the interpretation of the flow visualization data, we analyzed high-speed kinematic data (1,000 frames per second) of wing tips and wing roots as C. anna hovered in normal air. These data were used to refine several simplified models of vortex topology. The observed flow patterns can be explained by either a single loop model with an hourglass shape or a bilateral model, with the latter being more likely. When hovering in normal air, hummingbirds used an average stroke amplitude of 153.6° (range 148.9°-164.4°) and a wingbeat frequency of 38.5 Hz (range 38.1-39.1 Hz). When hovering in the white plume, hummingbirds used shallower stroke amplitudes ( bar{x} = 129.8°, range 116.3°-154.1°) and faster wingbeat frequencies ( bar{x} = 41.1 Hz, range 38.5-44.7 Hz), although the bilateral jets and associated vortices were observed across the full kinematic range. The plume did not

  13. Experimental study on two-phase flow in horizontal duct using a visualization technique

    International Nuclear Information System (INIS)

    Oliveira, Livia A.; Tomas, Bruno T.; Cunha Filho, Jurandyr S.; Su, Jian

    2009-01-01

    In this paper an experimental study is performed for visualization of water-air two phase flow, stratified and intermittent, in a 51 mm internal diameter circular section horizontal tube. The study consists in filming a water-air mixture passin by a transparent interval of the tube, using a high speed camera. After that, the obtained images are analysed frame after frame and then, data are extracted of weight of gas-liquid interfaces, length and gas bubbles speeds. Then, these data are verified with experimental and theoretical correlations available in the literature

  14. Application of TensorFlow to recognition of visualized results of fragment molecular orbital (FMO) calculations

    OpenAIRE

    Saitou, Sona; Iijima, Jun; Fujimoto, Mayu; Mochizuki, Yuji; Okuwaki, Koji; Doi, Hideo; Komeiji, Yuto

    2018-01-01

    We have applied Google's TensorFlow deep learning toolkit to recognize the visualized results of the fragment molecular orbital (FMO) calculations. Typical protein structures of alpha-helix and beta-sheet provide some characteristic patterns in the two-dimensional map of inter-fragment interaction energy termed as IFIE-map (Kurisaki et al., Biophys. Chem. 130 (2007) 1). A thousand of IFIE-map images with labels depending on the existences of alpha-helix and beta-sheet were prepared by employi...

  15. Reading impairment in schizophrenia: dysconnectivity within the visual system.

    Science.gov (United States)

    Vinckier, Fabien; Cohen, Laurent; Oppenheim, Catherine; Salvador, Alexandre; Picard, Hernan; Amado, Isabelle; Krebs, Marie-Odile; Gaillard, Raphaël

    2014-01-01

    Patients with schizophrenia suffer from perceptual visual deficits. It remains unclear whether those deficits result from an isolated impairment of a localized brain process or from a more diffuse long-range dysconnectivity within the visual system. We aimed to explore, with a reading paradigm, the functioning of both ventral and dorsal visual pathways and their interaction in schizophrenia. Patients with schizophrenia and control subjects were studied using event-related functional MRI (fMRI) while reading words that were progressively degraded through word rotation or letter spacing. Reading intact or minimally degraded single words involves mainly the ventral visual pathway. Conversely, reading in non-optimal conditions involves both the ventral and the dorsal pathway. The reading paradigm thus allowed us to study the functioning of both pathways and their interaction. Behaviourally, patients with schizophrenia were selectively impaired at reading highly degraded words. While fMRI activation level was not different between patients and controls, functional connectivity between the ventral and dorsal visual pathways increased with word degradation in control subjects, but not in patients. Moreover, there was a negative correlation between the patients' behavioural sensitivity to stimulus degradation and dorso-ventral connectivity. This study suggests that perceptual visual deficits in schizophrenia could be related to dysconnectivity between dorsal and ventral visual pathways. © 2013 Published by Elsevier Ltd.

  16. Human visual system automatically represents large-scale sequential regularities.

    Science.gov (United States)

    Kimura, Motohiro; Widmann, Andreas; Schröger, Erich

    2010-03-04

    Our brain recordings reveal that large-scale sequential regularities defined across non-adjacent stimuli can be automatically represented in visual sensory memory. To show that, we adopted an auditory paradigm developed by Sussman, E., Ritter, W., and Vaughan, H. G. Jr. (1998). Predictability of stimulus deviance and the mismatch negativity. NeuroReport, 9, 4167-4170, Sussman, E., and Gumenyuk, V. (2005). Organization of sequential sounds in auditory memory. NeuroReport, 16, 1519-1523 to the visual domain by presenting task-irrelevant infrequent luminance-deviant stimuli (D, 20%) inserted among task-irrelevant frequent stimuli being of standard luminance (S, 80%) in randomized (randomized condition, SSSDSSSSSDSSSSD...) and fixed manners (fixed condition, SSSSDSSSSDSSSSD...). Comparing the visual mismatch negativity (visual MMN), an event-related brain potential (ERP) index of memory-mismatch processes in human visual sensory system, revealed that visual MMN elicited by deviant stimuli was reduced in the fixed compared to the randomized condition. Thus, the large-scale sequential regularity being present in the fixed condition (SSSSD) must have been represented in visual sensory memory. Interestingly, this effect did not occur in conditions with stimulus-onset asynchronies (SOAs) of 480 and 800 ms but was confined to the 160-ms SOA condition supporting the hypothesis that large-scale regularity extraction was based on perceptual grouping of the five successive stimuli defining the regularity. 2010 Elsevier B.V. All rights reserved.

  17. Flow regime visualization and pressure drops of HFO-1234yf, R-134a and R-410A during downward two-phase flow in vertical return bends

    International Nuclear Information System (INIS)

    Padilla, Miguel; Revellin, Rémi; Wallet, Jérémy; Bonjour, Jocelyn

    2013-01-01

    Highlights: ► Visual observation of two-phase flow regimes during downward flow in a return bend. ► Bubble and vapor slug dynamical behaviors in downward slug flow are reported. ► Perturbation lengths up- and downstream of the return bend have been investigated. ► Measurement of 285 pressure drop data points for HFO-1234yf, R-134a and R-410A. -- Abstract: This paper provides a qualitative visual observation of the two-phase flow patterns for HFO-1234yf and R-134a during downward flow in a vertical 6.7 mm inner diameter glass return bend. The different flow regimes observed are: slug, intermittent and annular flows. Bubble and vapor slug dynamical behaviors in downward slug flow are reported for HFO-1234yf. In addition, to determine the perturbation lengths up- and downstream of the return bend, the total pressure drop has been measured at different pressure tap location up- and downstream of the singularity. Furthermore, 285 pressure drop data points measured for two-phase flow of HFO-1234yf, R-134a and R-410A in vertical downward flow return bends are presented. The flow behavior in the return bend, which is subjected to the complex combined actions of gravity and centrifugal force was expressed in terms of the vapor Froude number. This experimental pressure drop database, which is included in the appendix, is compared to four well-known prediction methods available in the literature

  18. Unification of three linear models for the transient visual system

    NARCIS (Netherlands)

    Brinker, den A.C.

    1989-01-01

    Three different linear filters are considered as a model describing the experimentally determined triphasic impulse responses of discs. These impulse responses arc associated with the transient visual system. Each model reveals a different feature of the system. Unification of the models is

  19. COALA-System for Visual Representation of Cryptography Algorithms

    Science.gov (United States)

    Stanisavljevic, Zarko; Stanisavljevic, Jelena; Vuletic, Pavle; Jovanovic, Zoran

    2014-01-01

    Educational software systems have an increasingly significant presence in engineering sciences. They aim to improve students' attitudes and knowledge acquisition typically through visual representation and simulation of complex algorithms and mechanisms or hardware systems that are often not available to the educational institutions. This paper…

  20. VisTool: A user interface and visualization development system

    DEFF Research Database (Denmark)

    Xu, Shangjin

    system – to simplify user interface development. VisTool allows user interface development without real programming. With VisTool a designer assembles visual objects (e.g. textboxes, ellipse, etc.) to visualize database contents. In VisTool, visual properties (e.g. color, position, etc.) can be formulas...... programming. However, in Software Engineering, software engineers who develop user interfaces do not follow it. In many cases, it is desirable to use graphical presentations, because a graphical presentation gives a better overview than text forms, and can improve task efficiency and user satisfaction....... However, it is more difficult to follow the classical usability approach for graphical presentation development. These difficulties result from the fact that designers cannot implement user interface with interactions and real data. We developed VisTool – a user interface and visualization development...

  1. Visualization tool. 3DAVS and polarization-type VR system

    International Nuclear Information System (INIS)

    Takeda, Yasuhiro; Ueshima, Yutaka

    2003-01-01

    In the visualization work of simulation data in every advanced research field, what is used most in the report or the presentation as a research result has still remained in the stages of the still picture or the 2-dimensional animation, in spite of recent abundance of various visualization software. With the recent progress of computational environment, however, more complicated phenomena can be so easily computed that the results are more needed to be comprehensible as well as intelligible. Therefore, it inevitably requires an animation rather than a still picture, or 3-dimensional display (virtual reality) rather than 2-dimensional one. In this report, two visualization tools, 3DAVS and Polarization-Type VR system are described as the data expression method after visualization processing. (author)

  2. Visual gravitational motion and the vestibular system in humans

    Directory of Open Access Journals (Sweden)

    Francesco eLacquaniti

    2013-12-01

    Full Text Available The visual system is poorly sensitive to arbitrary accelerations, but accurately detects the effects of gravity on a target motion. Here we review behavioral and neuroimaging data about the neural mechanisms for dealing with object motion and egomotion under gravity. The results from several experiments show that the visual estimates of a target motion under gravity depend on the combination of a prior of gravity effects with on-line visual signals on target position and velocity. These estimates are affected by vestibular inputs, and are encoded in a visual-vestibular network whose core regions lie within or around the Sylvian fissure, and are represented by the posterior insula/retroinsula/temporo-parietal junction. This network responds both to target motions coherent with gravity and to vestibular caloric stimulation in human fMRI studies. Transient inactivation of the temporo-parietal junction selectively disrupts the interception of targets accelerated by gravity.

  3. Visual gravitational motion and the vestibular system in humans.

    Science.gov (United States)

    Lacquaniti, Francesco; Bosco, Gianfranco; Indovina, Iole; La Scaleia, Barbara; Maffei, Vincenzo; Moscatelli, Alessandro; Zago, Myrka

    2013-12-26

    The visual system is poorly sensitive to arbitrary accelerations, but accurately detects the effects of gravity on a target motion. Here we review behavioral and neuroimaging data about the neural mechanisms for dealing with object motion and egomotion under gravity. The results from several experiments show that the visual estimates of a target motion under gravity depend on the combination of a prior of gravity effects with on-line visual signals on target position and velocity. These estimates are affected by vestibular inputs, and are encoded in a visual-vestibular network whose core regions lie within or around the Sylvian fissure, and are represented by the posterior insula/retroinsula/temporo-parietal junction. This network responds both to target motions coherent with gravity and to vestibular caloric stimulation in human fMRI studies. Transient inactivation of the temporo-parietal junction selectively disrupts the interception of targets accelerated by gravity.

  4. Visualization of two-phase gas-liquid flow regimes in horizontal and slightly-inclined circular tubes

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Livia Alves [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil); Nuclear Engineering Institute (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)], E-mail: livia@lasme.coppe.ufrj.br; Cunha Filho, Jurandyr; Su, Jian [Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE/UFRJ), RJ (Brazil). Nuclear Engineering Program], Emails: cunhafilho@lasme.coppe.ufrj.br, sujian@lasme.coppe.ufrj.br; Faccini, Jose Luiz Horacio [Nuclear Engineering Institute (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)], E-mail: faccini@ien.gov.br

    2010-07-01

    In this paper a flow visualization study was performed for two-phase gas-liquid flow in horizontal and slightly inclined tubes. The test section consists of a 2.54 cm inner diameter stainless steel circular tube, followed by a transparent acrylic tube with the same inner diameter. The working fluids were air and water, with liquid superficial velocities ranging from 0:11 to 3:28 m/s and gas superficial velocities ranging from 0:27 to 5:48 m/s. Flow visualization was executed for upward flow at 5 deg and 10 deg and downward flow at 2:5 deg, 5 deg and 10 deg, as well as for horizontal flow. The visualization technique consists of a high-speed digital camera that records images at rates of 125 and 250 frames per second of a concurrent air-water mixture through a transparent part of the tube. From the obtained images, the flow regimes were identified (except for annular flow), observing the effect of inclination angles on flow regime transition boundaries. Finally, the experimental results were compared with empirical and theoretical flow pattern maps available in literature. (author)

  5. Five-dimensional ultrasound system for soft tissue visualization.

    Science.gov (United States)

    Deshmukh, Nishikant P; Caban, Jesus J; Taylor, Russell H; Hager, Gregory D; Boctor, Emad M

    2015-12-01

    A five-dimensional ultrasound (US) system is proposed as a real-time pipeline involving fusion of 3D B-mode data with the 3D ultrasound elastography (USE) data as well as visualization of these fused data and a real-time update capability over time for each consecutive scan. 3D B-mode data assist in visualizing the anatomy of the target organ, and 3D elastography data adds strain information. We investigate the feasibility of such a system and show that an end-to-end real-time system, from acquisition to visualization, can be developed. We present a system that consists of (a) a real-time 3D elastography algorithm based on a normalized cross-correlation (NCC) computation on a GPU; (b) real-time 3D B-mode acquisition and network transfer; (c) scan conversion of 3D elastography and B-mode volumes (if acquired by 4D wobbler probe); and (d) visualization software that fuses, visualizes, and updates 3D B-mode and 3D elastography data in real time. We achieved a speed improvement of 4.45-fold for the threaded version of the NCC-based 3D USE versus the non-threaded version. The maximum speed was 79 volumes/s for 3D scan conversion. In a phantom, we validated the dimensions of a 2.2-cm-diameter sphere scan-converted to B-mode volume. Also, we validated the 5D US system visualization transfer function and detected 1- and 2-cm spherical objects (phantom lesion). Finally, we applied the system to a phantom consisting of three lesions to delineate the lesions from the surrounding background regions of the phantom. A 5D US system is achievable with real-time performance. We can distinguish between hard and soft areas in a phantom using the transfer functions.

  6. Guidelines to Visualize Vessels in a Geographic Information System

    OpenAIRE

    Rodighiero, Dario

    2010-01-01

    In information systems the data representation covers a great importance. In fact the visualization of information is the last point of contact between the user and the information system. This is the space where the communication takes place. In real-time monitoring systems, this passage covers a great importance, especially for reasons related to the time and the transparency of relevant information. These factors are fundamental to vessel monitoring systems. This is the beginning where we ...

  7. Experience-independent development of the hamster circadian visual system.

    Directory of Open Access Journals (Sweden)

    August Kampf-Lassin

    2011-04-01

    Full Text Available Experience-dependent functional plasticity is a hallmark of the primary visual system, but it is not known if analogous mechanisms govern development of the circadian visual system. Here we investigated molecular, anatomical, and behavioral consequences of complete monocular light deprivation during extended intervals of postnatal development in Syrian hamsters. Hamsters were raised in constant darkness and opaque contact lenses were applied shortly after eye opening and prior to the introduction of a light-dark cycle. In adulthood, previously-occluded eyes were challenged with visual stimuli. Whereas image-formation and motion-detection were markedly impaired by monocular occlusion, neither entrainment to a light-dark cycle, nor phase-resetting responses to shifts in the light-dark cycle were affected by prior monocular deprivation. Cholera toxin-b subunit fluorescent tract-tracing revealed that in monocularly-deprived hamsters the density of fibers projecting from the retina to the suprachiasmatic nucleus (SCN was comparable regardless of whether such fibers originated from occluded or exposed eyes. In addition, long-term monocular deprivation did not attenuate light-induced c-Fos expression in the SCN. Thus, in contrast to the thalamocortical projections of the primary visual system, retinohypothalamic projections terminating in the SCN develop into normal adult patterns and mediate circadian responses to light largely independent of light experience during development. The data identify a categorical difference in the requirement for light input during postnatal development between circadian and non-circadian visual systems.

  8. Radionuclides in groundwater flow system understanding

    Science.gov (United States)

    Erőss, Anita; Csondor, Katalin; Horváth, Ákos; Mádl-Szőnyi, Judit; Surbeck, Heinz

    2017-04-01

    Using radionuclides is a novel approach to characterize fluids of groundwater flow systems and understand their mixing. Particularly, in regional discharge areas, where different order flow systems convey waters with different temperature, composition and redox-state to the discharge zone. Radium and uranium are redox-sensitive parameters, which causes fractionation along groundwater flow paths. Discharging waters of regional flow systems are characterized by elevated total dissolved solid content (TDS), temperature and by reducing conditions, and therefore with negligible uranium content, whereas local flow systems have lower TDS and temperature and represent oxidizing environments, and therefore their radium content is low. Due to the short transit time, radon may appear in local systems' discharge, where its source is the soil zone. However, our studies revealed the importance of FeOOH precipitates as local radon sources throughout the adsorption of radium transported by the thermal waters of regional flow systems. These precipitates can form either by direct oxidizing of thermal waters at discharge, or by mixing of waters with different redox state. Therefore elevated radon content often occurs in regional discharge areas as well. This study compares the results of geochemical studies in three thermal karst areas in Hungary, focusing on radionuclides as natural tracers. In the Buda Thermal Karst, the waters of the distinct discharge areas are characterized by different temperature and chemical composition. In the central discharge area both lukewarm (20-35°C, 770-980 mg/l TDS) and thermal waters (40-65°C, 800-1350 mg/l TDS), in the South only thermal water discharge (33-43°C, 1450-1700 mg/l TDS) occur. Radionuclides helped to identify mixing of fluids and to infer the temperature and chemical composition of the end members for the central discharge area. For the southern discharge zone mixing components could not be identified, which suggests different cave

  9. Visualization of three pathways for macromolecule transport across cultured endothelium and their modification by flow.

    Science.gov (United States)

    Ghim, Mean; Alpresa, Paola; Yang, Sung-Wook; Braakman, Sietse T; Gray, Stephen G; Sherwin, Spencer J; van Reeuwijk, Maarten; Weinberg, Peter D

    2017-11-01

    Transport of macromolecules across vascular endothelium and its modification by fluid mechanical forces are important for normal tissue function and in the development of atherosclerosis. However, the routes by which macromolecules cross endothelium, the hemodynamic stresses that maintain endothelial physiology or trigger disease, and the dependence of transendothelial transport on hemodynamic stresses are controversial. We visualized pathways for macromolecule transport and determined the effect on these pathways of different types of flow. Endothelial monolayers were cultured under static conditions or on an orbital shaker producing different flow profiles in different parts of the wells. Fluorescent tracers that bound to the substrate after crossing the endothelium were used to identify transport pathways. Maps of tracer distribution were compared with numerical simulations of flow to determine effects of different shear stress metrics on permeability. Albumin-sized tracers dominantly crossed the cultured endothelium via junctions between neighboring cells, high-density lipoprotein-sized tracers crossed at tricellular junctions, and low-density lipoprotein-sized tracers crossed through cells. Cells aligned close to the angle that minimized shear stresses across their long axis. The rate of paracellular transport under flow correlated with the magnitude of these minimized transverse stresses, whereas transport across cells was uniformly reduced by all types of flow. These results contradict the long-standing two-pore theory of solute transport across microvessel walls and the consensus view that endothelial cells align with the mean shear vector. They suggest that endothelial cells minimize transverse shear, supporting its postulated proatherogenic role. Preliminary data show that similar tracer techniques are practicable in vivo. NEW & NOTEWORTHY Solutes of increasing size crossed cultured endothelium through intercellular junctions, through tricellular

  10. Visuals and Visualisation of Human Body Systems

    Science.gov (United States)

    Mathai, Sindhu; Ramadas, Jayashree

    2009-01-01

    This paper explores the role of diagrams and text in middle school students' understanding and visualisation of human body systems. We develop a common framework based on structure and function to assess students' responses across diagram and verbal modes. Visualisation is defined in terms of understanding transformations on structure and relating…

  11. Flow visualization through particle image velocimetry in realistic model of rhesus monkey's upper airway.

    Science.gov (United States)

    Kim, Ji-Woong; Phuong, Nguyen Lu; Aramaki, Shin-Ichiro; Ito, Kazuhide

    2018-05-01

    Studies concerning inhalation toxicology and respiratory drug-delivery systems require biological testing involving experiments performed on animals. Particle image velocimetry (PIV) is an effective in vitro technique that reveals detailed inhalation flow patterns, thereby assisting analyses of inhalation exposure to various substances. A realistic model of a rhesus-monkey upper airway was developed to investigate flow patterns in its oral and nasal cavities through PIV experiments performed under steady-state constant inhalation conditions at various flow rates-4, 10, and 20 L/min. Flow rate of the fluid passing through the inlet into the trachea was measured to obtain characteristic flow mechanisms, and flow phenomena in the model were confirmed via characterized flow fields. It was observed that increase in flow rate leads to constant velocity profiles in upper and lower trachea regions. It is expected that the results of this study would contribute to future validation of studies aimed at developing in silico models, especially those involving computational fluid dynamic (CFD) analysis. Copyright © 2018 Elsevier B.V. All rights reserved.

  12. Online Voting System Based on Image Steganography and Visual Cryptography

    Directory of Open Access Journals (Sweden)

    Biju Issac

    2017-01-01

    Full Text Available This paper discusses the implementation of an online voting system based on image steganography and visual cryptography. The system was implemented in Java EE on a web-based interface, with MySQL database server and Glassfish application server as the backend. After considering the requirements of an online voting system, current technologies on electronic voting schemes in published literature were examined. Next, the cryptographic and steganography techniques best suited for the requirements of the voting system were chosen, and the software was implemented. We have incorporated in our system techniques like the password hashed based scheme, visual cryptography, F5 image steganography and threshold decryption cryptosystem. The analysis, design and implementation phase of the software development of the voting system is discussed in detail. We have also used a questionnaire survey and did the user acceptance testing of the system.

  13. System for recording and displaying two-phase flow topographies

    International Nuclear Information System (INIS)

    Cary, C.N.; Block, J.A.

    1979-01-01

    A system of hardware and software has been developed and used to record and display in various forms details of the countercurrent flow topographies occurring in a scaled Pressurized Water Reactor downcomer annulus. An array of 288 conductivity sensors was mounted in a 1/15 scale PWR annulus. At each moment in time, the state of each probe indicates the presence or absence of water in this immediate vicinity. An electronic data acquisition system records the states of all probes 108 times per second on magnetic tape; software routines retrieve the data and reconstruct visual analogs of the flow topographies. The instantaneous two-phase state of the annulus at each instant can be displayed on a hard copy plotter or on a CRT screen. By synchronizing a camera drive with the CRT display, 16mm films have been made recreating the flow process at full speed and at various slow motion rates. All data obtained are stored in computer files in numerical form and can be subjected to various types of quantitative analysis to assist in advanced code development and verification

  14. Design of a two-phase loop thermosyphon for telecommunications system(I): experiments and visualization

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Won Tae [Kongju National Univ., Kongju (Korea, Republic of); Song, Kyu Sub [Electronics and Telecommunications Research Institute, Taejon (Korea, Republic of); Lee, Young [Univ. of Ottawa, Ontario (Canada)

    1998-10-01

    A two-phase loop thermosyphon system is developed for the B-ISDN telecommunications system and its performance is evaluated both experimentally and by visualization techniques. The design of the thermosyphon system proposed is aimed to cool MultiChip Modules (MCM) upto heat flux of 8 W/cm{sup 2}. The results indicate that in the loop thermosyphon system cooling heat flux is capable of 12 W/cm{sup 2} with two condensers under the forced convection cooling of the condenser section with acetone or FC-87 as the working fluid. The instability of the working fluid flow within the loop is observed using the visualization techniques and temperature fluctuation is stabilized with orifice insertion.

  15. Design of a two-phase loop thermosyphon for telecommunications system(I): experiments and visualization

    International Nuclear Information System (INIS)

    Kim, Won Tae; Song, Kyu Sub; Lee, Young

    1998-01-01

    A two-phase loop thermosyphon system is developed for the B-ISDN telecommunications system and its performance is evaluated both experimentally and by visualization techniques. The design of the thermosyphon system proposed is aimed to cool MultiChip Modules (MCM) upto heat flux of 8 W/cm 2 . The results indicate that in the loop thermosyphon system cooling heat flux is capable of 12 W/cm 2 with two condensers under the forced convection cooling of the condenser section with acetone or FC-87 as the working fluid. The instability of the working fluid flow within the loop is observed using the visualization techniques and temperature fluctuation is stabilized with orifice insertion

  16. Improving the visualization of electron-microscopy data through optical flow interpolation

    KAUST Repository

    Carata, Lucian

    2013-01-01

    Technical developments in neurobiology have reached a point where the acquisition of high resolution images representing individual neurons and synapses becomes possible. For this, the brain tissue samples are sliced using a diamond knife and imaged with electron-microscopy (EM). However, the technique achieves a low resolution in the cutting direction, due to limitations of the mechanical process, making a direct visualization of a dataset difficult. We aim to increase the depth resolution of the volume by adding new image slices interpolated from the existing ones, without requiring modifications to the EM image-capturing method. As classical interpolation methods do not provide satisfactory results on this type of data, the current paper proposes a re-framing of the problem in terms of motion volumes, considering the depth axis as a temporal axis. An optical flow method is adapted to estimate the motion vectors of pixels in the EM images, and this information is used to compute and insert multiple new images at certain depths in the volume. We evaluate the visualization results in comparison with interpolation methods currently used on EM data, transforming the highly anisotropic original dataset into a dataset with a larger depth resolution. The interpolation based on optical flow better reveals neurite structures with realistic undistorted shapes, and helps to easier map neuronal connections. © 2011 ACM.

  17. A magnetic tether system to investigate visual and olfactory mediated flight control in Drosophila.

    Science.gov (United States)

    Duistermars, Brian J; Frye, Mark

    2008-11-21

    It has been clear for many years that insects use visual cues to stabilize their heading in a wind stream. Many animals track odors carried in the wind. As such, visual stabilization of upwind tracking directly aids in odor tracking. But do olfactory signals directly influence visual tracking behavior independently from wind cues? Also, the recent deluge of research on the neurophysiology and neurobehavioral genetics of olfaction in Drosophila has motivated ever more technically sophisticated and quantitative behavioral assays. Here, we modified a magnetic tether system originally devised for vision experiments by equipping the arena with narrow laminar flow odor plumes. A fly is glued to a small steel pin and suspended in a magnetic field that enables it to yaw freely. Small diameter food odor plumes are directed downward over the fly's head, eliciting stable tracking by a hungry fly. Here we focus on the critical mechanics of tethering, aligning the magnets, devising the odor plume, and confirming stable odor tracking.

  18. Visual hull method for tomographic PIV measurement of flow around moving objects

    Energy Technology Data Exchange (ETDEWEB)

    Adhikari, D.; Longmire, E.K. [University of Minnesota, Department of Aerospace Engineering and Mechanics, Minneapolis, MN (United States)

    2012-10-15

    Tomographic particle image velocimetry (PIV) is a recently developed method to measure three components of velocity within a volumetric space. We present a visual hull technique that automates identification and masking of discrete objects within the measurement volume, and we apply existing tomographic PIV reconstruction software to measure the velocity surrounding the objects. The technique is demonstrated by considering flow around falling bodies of different shape with Reynolds number {proportional_to}1,000. Acquired image sets are processed using separate routines to reconstruct both the volumetric mask around the object and the surrounding tracer particles. After particle reconstruction, the reconstructed object mask is used to remove any ghost particles that otherwise appear within the object volume. Velocity vectors corresponding with fluid motion can then be determined up to the boundary of the visual hull without being contaminated or affected by the neighboring object velocity. Although the visual hull method is not meant for precise tracking of objects, the reconstructed object volumes nevertheless can be used to estimate the object location and orientation at each time step. (orig.)

  19. Satellite Imagery Assisted Road-Based Visual Navigation System

    Science.gov (United States)

    Volkova, A.; Gibbens, P. W.

    2016-06-01

    There is a growing demand for unmanned aerial systems as autonomous surveillance, exploration and remote sensing solutions. Among the key concerns for robust operation of these systems is the need to reliably navigate the environment without reliance on global navigation satellite system (GNSS). This is of particular concern in Defence circles, but is also a major safety issue for commercial operations. In these circumstances, the aircraft needs to navigate relying only on information from on-board passive sensors such as digital cameras. An autonomous feature-based visual system presented in this work offers a novel integral approach to the modelling and registration of visual features that responds to the specific needs of the navigation system. It detects visual features from Google Earth* build a feature database. The same algorithm then detects features in an on-board cameras video stream. On one level this serves to localise the vehicle relative to the environment using Simultaneous Localisation and Mapping (SLAM). On a second level it correlates them with the database to localise the vehicle with respect to the inertial frame. The performance of the presented visual navigation system was compared using the satellite imagery from different years. Based on comparison results, an analysis of the effects of seasonal, structural and qualitative changes of the imagery source on the performance of the navigation algorithm is presented. * The algorithm is independent of the source of satellite imagery and another provider can be used

  20. UNCERT: geostatistics, uncertainty analysis and visualization software applied to groundwater flow and contaminant transport modeling

    International Nuclear Information System (INIS)

    Wingle, W.L.; Poeter, E.P.; McKenna, S.A.

    1999-01-01

    UNCERT is a 2D and 3D geostatistics, uncertainty analysis and visualization software package applied to ground water flow and contaminant transport modeling. It is a collection of modules that provides tools for linear regression, univariate statistics, semivariogram analysis, inverse-distance gridding, trend-surface analysis, simple and ordinary kriging and discrete conditional indicator simulation. Graphical user interfaces for MODFLOW and MT3D, ground water flow and contaminant transport models, are provided for streamlined data input and result analysis. Visualization tools are included for displaying data input and output. These include, but are not limited to, 2D and 3D scatter plots, histograms, box and whisker plots, 2D contour maps, surface renderings of 2D gridded data and 3D views of gridded data. By design, UNCERT's graphical user interface and visualization tools facilitate model design and analysis. There are few built in restrictions on data set sizes and each module (with two exceptions) can be run in either graphical or batch mode. UNCERT is in the public domain and is available from the World Wide Web with complete on-line and printable (PDF) documentation. UNCERT is written in ANSI-C with a small amount of FORTRAN77, for UNIX workstations running X-Windows and Motif (or Lesstif). This article discusses the features of each module and demonstrates how they can be used individually and in combination. The tools are applicable to a wide range of fields and are currently used by researchers in the ground water, mining, mathematics, chemistry and geophysics, to name a few disciplines. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  1. Automatic Visualization of Software Requirements: Reactive Systems

    International Nuclear Information System (INIS)

    Castello, R.; Mili, R.; Tollis, I.G.; Winter, V.

    1999-01-01

    In this paper we present an approach that facilitates the validation of high consequence system requirements. This approach consists of automatically generating a graphical representation from an informal document. Our choice of a graphical notation is statecharts. We proceed in two steps: we first extract a hierarchical decomposition tree from a textual description, then we draw a graph that models the statechart in a hierarchical fashion. The resulting drawing is an effective requirements assessment tool that allows the end user to easily pinpoint inconsistencies and incompleteness

  2. The development of a visual system for the detection of obstructions for visually impaired people

    International Nuclear Information System (INIS)

    Okayasu, Mitsuhiro

    2009-01-01

    In this paper, the author presents a new visual system that can aid visually impaired people in walking. The system provides object information (that is, shape and location) through the sense of touch. This visual system depends on three different components: (i) an infrared camera sensor that detects the obstruction, (ii) a control system that measures the distance between the obstruction and the sensor, and (iii) a tooling apparatus with small pins (φ1 mm) used in forming a three-dimensional shape of the obstruction. The pins, arranged on a 6x6 matrix, move longitudinally between the retracted and extended positions based on the distance data. The pin extends individually, while the pin tip reflects the object's outer surface. The length of the pin from the base surface is proportional to the distance of the sensor from the obstruction. An ultrasonic actuator, controlled at a 15Hz frame rate, is the driving force for the pin movement. The tactile image of the 3D shape can provide information about the obstruction

  3. Reactor core flow rate control system

    International Nuclear Information System (INIS)

    Sakuma, Hitoshi; Tanikawa, Naoshi; Takahashi, Toshiyuki; Miyakawa, Tetsuya.

    1996-01-01

    When an internal pump is started by a variable frequency power source device, if magnetic fields of an AC generator are introduced after the rated speed is reached, neutron flux high scram occurs by abrupt increase of a reactor core flow rate. Then, in the present invention, magnetic fields for the AC generator are introduced at a speed previously set at which the fluctuation range of the reactor core flow rate (neutron flux) by the start up of the internal pump is within an allowable value. Since increase of the speed of the internal pump upon its start up is suppressed to determine the change of the reactor core flow rate within an allowable range, increase of neutron fluxes is suppressed to enable stable start up. Then, since transition boiling of fuels caused by abrupt decrease of the reactor core flow rate upon occurrence of abnormality in an external electric power system is prevented, and the magnetic fields for the AC generator are introduced in such a manner to put the speed increase fluctuation range of the internal pump upon start up within an allowable value, neutron flux high scram is not caused to enable stable start-up. (N.H.)

  4. Living Color Frame System: PC graphics tool for data visualization

    Science.gov (United States)

    Truong, Long V.

    1993-01-01

    Living Color Frame System (LCFS) is a personal computer software tool for generating real-time graphics applications. It is highly applicable for a wide range of data visualization in virtual environment applications. Engineers often use computer graphics to enhance the interpretation of data under observation. These graphics become more complicated when 'run time' animations are required, such as found in many typical modern artificial intelligence and expert systems. Living Color Frame System solves many of these real-time graphics problems.

  5. Alert system for students with visual disabilities at the UTM

    Directory of Open Access Journals (Sweden)

    Marely del Rosario Cruz Felipe

    2018-01-01

    Full Text Available In the transfer of students with visual disabilities at the Technical University of Manabí (UTM accidents have been reported when going through some ramps and other obstacles, especially on rainy days. This article belongs to an investigation into the realization of an alert system for students with visual disabilities. The objective of the implementation of this system is to guide students with visual disabilities on different obstacles that exist in their transfer through the university. To carry out the implementation of this system, the alert systems and the technologies that are currently used as a result of a recording studio in the national and international scope were analyzed, the tools and technologies used in the developed solution are described. (Definition, technologies for the change of people, software, programming languages, etc. that allowed an efficient implementation in a short time of the proposed system by means of RFID (Radio Frequency Identification technology. The above is reflected in the positive orientation for the transfer of 32 students with visual disabilities through the university and by those who have contributed to improving their quality of life.

  6. New apparatus of single particle trap system for aerosol visualization

    Science.gov (United States)

    Higashi, Hidenori; Fujioka, Tomomi; Endo, Tetsuo; Kitayama, Chiho; Seto, Takafumi; Otani, Yoshio

    2014-08-01

    Control of transport and deposition of charged aerosol particles is important in various manufacturing processes. Aerosol visualization is an effective method to directly observe light scattering signal from laser-irradiated single aerosol particle trapped in a visualization cell. New single particle trap system triggered by light scattering pulse signal was developed in this study. The performance of the device was evaluated experimentally. Experimental setup consisted of an aerosol generator, a differential mobility analyzer (DMA), an optical particle counter (OPC) and the single particle trap system. Polystylene latex standard (PSL) particles (0.5, 1.0 and 2.0 μm) were generated and classified according to the charge by the DMA. Singly charged 0.5 and 1.0 μm particles and doubly charged 2.0 μm particles were used as test particles. The single particle trap system was composed of a light scattering signal detector and a visualization cell. When the particle passed through the detector, trigger signal with a given delay time sent to the solenoid valves upstream and downstream of the visualization cell for trapping the particle in the visualization cell. The motion of particle in the visualization cell was monitored by CCD camera and the gravitational settling velocity and the electrostatic migration velocity were measured from the video image. The aerodynamic diameter obtained from the settling velocity was in good agreement with Stokes diameter calculated from the electrostatic migration velocity for individual particles. It was also found that the aerodynamic diameter obtained from the settling velocity was a one-to-one function of the scattered light intensity of individual particles. The applicability of this system will be discussed.

  7. Visualized study on specific points on demand curves and flow patterns in a single-side heated narrow rectangular channel

    International Nuclear Information System (INIS)

    Wang Junfeng; Huang Yanping; Wang Yanlin

    2011-01-01

    Highlights: → Specific points on the demand curve and flow patterns are visually studied. → Bubbly, churn, and annular flows were observed. → Onset of flow instability and bubbly-churn transition occurs at the same time. → The evolution of specific points and flow pattern transitions were examined. - Abstract: A simultaneous visualization and measurement study on some specific points on demand curves, such as onset of nucleate boiling (ONB), onset of significant void (OSV), onset of flow instability (OFI), and two-phase flow patterns in a single-side heated narrow rectangular channel, having a width of 40 mm and a gap of 3 mm, was carried out. New experimental approaches were adopted to identify OSV and OFI in a narrow rectangular channel. Under experimental conditions, the ONB could be predicted well by the Sato and Matsumura model. The OSV model of Bowring can reasonably predict the OSV if the single-side heated condition is considered. The OFI was close to the saturated boiling point and could be described accurately by Kennedy's correlation. The two-phase flow patterns observed in this experiment could be classified into bubbly, churn, and annular flow. Slug flow was never observed. The OFI always occurred when the bubbles at the channel exit began to coalesce, which corresponded to the beginning of the bubbly-churn transition in flow patterns. Finally, the evolution of specific points and flow pattern transitions were examined in a single-side heated narrow rectangular channel.

  8. Fluid flow dynamics in MAS systems

    Science.gov (United States)

    Wilhelm, Dirk; Purea, Armin; Engelke, Frank

    2015-08-01

    The turbine system and the radial bearing of a high performance magic angle spinning (MAS) probe with 1.3 mm-rotor diameter has been analyzed for spinning rates up to 67 kHz. We focused mainly on the fluid flow properties of the MAS system. Therefore, computational fluid dynamics (CFD) simulations and fluid measurements of the turbine and the radial bearings have been performed. CFD simulation and measurement results of the 1.3 mm-MAS rotor system show relatively low efficiency (about 25%) compared to standard turbo machines outside the realm of MAS. However, in particular, MAS turbines are mainly optimized for speed and stability instead of efficiency. We have compared MAS systems for rotor diameter of 1.3-7 mm converted to dimensionless values with classical turbomachinery systems showing that the operation parameters (rotor diameter, inlet mass flow, spinning rate) are in the favorable range. This dimensionless analysis also supports radial turbines for low speed MAS probes and diagonal turbines for high speed MAS probes. Consequently, a change from Pelton type MAS turbines to diagonal turbines might be worth considering for high speed applications. CFD simulations of the radial bearings have been compared with basic theoretical values proposing considerably smaller frictional loss values. The discrepancies might be due to the simple linear flow profile employed for the theoretical model. Frictional losses generated inside the radial bearings result in undesired heat-up of the rotor. The rotor surface temperature distribution computed by CFD simulations show a large temperature gradient over the rotor.

  9. Visualization of the boiling phenomena and counter-current flow limit of annular heat pipe

    Energy Technology Data Exchange (ETDEWEB)

    Kim, In Guk; Kim, Kyung Mo; Jeong, Yeong Shin; Bang, In Cheol [UNIST, Ulsan (Korea, Republic of)

    2015-10-15

    The thermal resistance of conventional heat pipes increases over the capillary limit because of the insufficient supplement of the working fluid. Due to the shortage of the liquid supplement, thermosyphon is widely used for vertically oriented heat transport and high heat load conditions. Thermosyphons are two-phase heat transfer devices that have the highly efficient heat transport from evaporation to condensation section that makes an upward driving force for vapor. In the condenser section, the vapor condenses and releases the latent heat. Due to the gravitation force acting on the liquid in the tube, working fluid back to the evaporator section, normally this process operate at the vertical and inclination position. The use of two-phase closed thermosyphon (TPCT) for the cooling devices has the limitation due to the phase change of the working fluid assisted by gravity force. Due to the complex phenomenon of two-phase flow, it is required to understand what happened in TPCT. The visualization of the thermosyphon and heat pipe is investigated for the decrease of thermal resistance and enhancement of operation limit. Weibel et al. investigated capillary-fed boiling of water with porous sintered powder wick structure using high speed camera. At the high heat flux condition, dry-out phenomenon and a thin liquid film are observed at the porous wick structure. Wong and Kao investigated the evaporation and boiling process of mesh wicked heat pipe using optical camera. At the high heat flux condition, the water filing became thin and partial dry-out was observed in the evaporator section. Our group suggested the concept of a hybrid heat pipe with control rod as Passive IN-core Cooling System (PINCs) for decay heat removal for advanced nuclear power plant. The hybrid heat pipe is the combination of the heat pipe and control rod. It is necessary for PINCs to contain a neutron absorber (B{sub 4}C) to have the ability of reactivity control. It has annular vapor space and

  10. Visualization of the boiling phenomena and counter-current flow limit of annular heat pipe

    International Nuclear Information System (INIS)

    Kim, In Guk; Kim, Kyung Mo; Jeong, Yeong Shin; Bang, In Cheol

    2015-01-01

    The thermal resistance of conventional heat pipes increases over the capillary limit because of the insufficient supplement of the working fluid. Due to the shortage of the liquid supplement, thermosyphon is widely used for vertically oriented heat transport and high heat load conditions. Thermosyphons are two-phase heat transfer devices that have the highly efficient heat transport from evaporation to condensation section that makes an upward driving force for vapor. In the condenser section, the vapor condenses and releases the latent heat. Due to the gravitation force acting on the liquid in the tube, working fluid back to the evaporator section, normally this process operate at the vertical and inclination position. The use of two-phase closed thermosyphon (TPCT) for the cooling devices has the limitation due to the phase change of the working fluid assisted by gravity force. Due to the complex phenomenon of two-phase flow, it is required to understand what happened in TPCT. The visualization of the thermosyphon and heat pipe is investigated for the decrease of thermal resistance and enhancement of operation limit. Weibel et al. investigated capillary-fed boiling of water with porous sintered powder wick structure using high speed camera. At the high heat flux condition, dry-out phenomenon and a thin liquid film are observed at the porous wick structure. Wong and Kao investigated the evaporation and boiling process of mesh wicked heat pipe using optical camera. At the high heat flux condition, the water filing became thin and partial dry-out was observed in the evaporator section. Our group suggested the concept of a hybrid heat pipe with control rod as Passive IN-core Cooling System (PINCs) for decay heat removal for advanced nuclear power plant. The hybrid heat pipe is the combination of the heat pipe and control rod. It is necessary for PINCs to contain a neutron absorber (B 4 C) to have the ability of reactivity control. It has annular vapor space and it

  11. Development of a system for acquiring, reconstructing, and visualizing three-dimensional ultrasonic angiograms

    Science.gov (United States)

    Edwards, Warren S.; Ritchie, Cameron J.; Kim, Yongmin; Mack, Laurence A.

    1995-04-01

    We have developed a three-dimensional (3D) imaging system using power Doppler (PD) ultrasound (US). This system can be used for visualizing and analyzing the vascular anatomy of parenchymal organs. To create the 3D PD images, we acquired a series of two-dimensional PD images from a commercial US scanner and recorded the position and orientation of each image using a 3D magnetic position sensor. Three-dimensional volumes were reconstructed using specially designed software and then volume rendered for display. We assessed the feasibility and geometric accuracy of our system with various flow phantoms. The system was then tested on a volunteer by scanning a transplanted kidney. The reconstructed volumes of the flow phantom contained less than 1 mm of geometric distortion and the 3D images of the transplanted kidney depicted the segmental, arcuate, and interlobar vessels.

  12. Coupling Retinal Scanning Displays to the Human Visual System: Visual System Response and Engineering Considerations

    National Research Council Canada - National Science Library

    Turner, Stuart

    2002-01-01

    A retinal scanning display (RSD) is a visual display that presents an image to an observer via a modulated beam of light that is directed through the eye's pupil and rapidly scanned in a raster-like pattern across the retina...

  13. Visualization of Biosurfactant Film Flow in a Bacillus subtilis Swarm Colony on an Agar Plate.

    Science.gov (United States)

    Kim, Kyunghoon; Kim, Jung Kyung

    2015-08-26

    Collective bacterial dynamics plays a crucial role in colony development. Although many research groups have studied the behavior of fluidic swarm colonies, the detailed mechanics of its motion remains elusive. Here, we developed a visualization method using submicron fluorescent beads for investigating the flow field in a thin layer of fluid that covers a Bacillus subtilis swarm colony growing on an agar plate. The beads were initially embedded in the agar plate and subsequently distributed spontaneously at the upper surface of the expanding colony. We conducted long-term live cell imaging of the B. subtilis colony using the fluorescent tracers, and obtained high-resolution velocity maps of microscale vortices in the swarm colony using particle image velocimetry. A distinct periodic fluctuation in the average speed and vorticity of flow in swarm colony was observed at the inner region of the colony, and correlated with the switch between bacterial swarming and growth phases. At the advancing edge of the colony, both the magnitudes of velocity and vorticity of flow in swarm colony were inversely correlated with the spreading speed of the swarm edge. The advanced imaging tool developed in this study would facilitate further understanding of the effect of micro vortices in swarm colony on the collective dynamics of bacteria.

  14. Visualization of pre-set vortices in boundary layer flow over wavy surface in rectangular channel

    KAUST Repository

    Budiman, Alexander Christantho

    2014-12-04

    Abstract: Smoke-wire flow visualization is used to study the development of pre-set counter-rotating streamwise vortices in boundary layer flow over a wavy surface in a rectangular channel. The formation of the vortices is indicated by the vortical structures on the cross-sectional plane normal to the wavy surface. To obtain uniform spanwise vortex wavelength which will result in uniform vortex size, two types of spanwise disturbances were used: a series of perturbation wires placed prior and normal to the leading edge of the wavy surface, and a jagged pattern in the form of uniform triangles cut at the leading edge. These perturbation wires and jagged pattern induce low-velocity streaks that result in the formation of counter-rotating streamwise vortices that evolve downstream to form the mushroom-like structures on the cross-sectional plane of the flow. The evolution of the most amplified disturbances can be attributed to the formation of these mushroom-like structures. It is also shown that the size of the mushroom-like structures depends on the channel entrance geometry, Reynolds number, and the channel gap.Graphical Abstract: [Figure not available: see fulltext.

  15. A flow visualization study of single-arm sculling movement emulating cephalopod thrust generation

    Science.gov (United States)

    Kazakidi, Asimina; Gnanamanickam, Ebenezer P.; Tsakiris, Dimitris P.; Ekaterinaris, John A.

    2014-11-01

    In addition to jet propulsion, octopuses use arm-swimming motion as an effective means of generating bursts of thrust, for hunting, defense, or escape. The individual role of their arms, acting as thrust generators during this motion, is still under investigation, in view of an increasing robotic interest for alternative modes of propulsion, inspired by the octopus. Computational studies have revealed that thrust generation is associated with complex vortical flow patterns in the wake of the moving arm, however further experimental validation is required. Using the hydrogen bubble technique, we studied the flow disturbance around a single octopus-like robotic arm, undergoing two-stroke sculling movements in quiescent fluid. Although simplified, sculling profiles have been found to adequately capture the fundamental kinematics of the octopus arm-swimming behavior. In fact, variation of the sculling parameters alters considerably the generation of forward thrust. Flow visualization revealed the generation of complex vortical structures around both rigid and compliant arms. Increased disturbance was evident near the tip, particularly at the transitional phase between recovery and power strokes. These results are in good qualitative agreement with computational and robotic studies. Work funded by the ESF-GSRT HYDRO-ROB Project PE7(281).

  16. The role of the visual hardware system in rugby performance ...

    African Journals Online (AJOL)

    This study explores the importance of the 'hardware' factors of the visual system in the game of rugby. A group of professional and club rugby players were tested and the results compared. The results were also compared with the established norms for elite athletes. The findings indicate no significant difference in hardware ...

  17. A Dynamic Systems Theory Model of Visual Perception Development

    Science.gov (United States)

    Coté, Carol A.

    2015-01-01

    This article presents a model for understanding the development of visual perception from a dynamic systems theory perspective. It contrasts to a hierarchical or reductionist model that is often found in the occupational therapy literature. In this proposed model vision and ocular motor abilities are not foundational to perception, they are seen…

  18. Simulation and Formal Analysis of Visual Attention in Cognitive Systems

    NARCIS (Netherlands)

    Bosse, T.; Maanen, P.P. van; Treur, J.

    2007-01-01

    In this paper a simulation model for visual attention is discussed and formally analysed. The model is part of the design of a cognitive system which comprises an agent that supports a naval officer in its task to compile a tactical picture of the situation in the field. A case study is described in

  19. Simple Smartphone-Based Guiding System for Visually Impaired People.

    Science.gov (United States)

    Lin, Bor-Shing; Lee, Cheng-Che; Chiang, Pei-Ying

    2017-06-13

    Visually impaired people are often unaware of dangers in front of them, even in familiar environments. Furthermore, in unfamiliar environments, such people require guidance to reduce the risk of colliding with obstacles. This study proposes a simple smartphone-based guiding system for solving the navigation problems for visually impaired people and achieving obstacle avoidance to enable visually impaired people to travel smoothly from a beginning point to a destination with greater awareness of their surroundings. In this study, a computer image recognition system and smartphone application were integrated to form a simple assisted guiding system. Two operating modes, online mode and offline mode, can be chosen depending on network availability. When the system begins to operate, the smartphone captures the scene in front of the user and sends the captured images to the backend server to be processed. The backend server uses the faster region convolutional neural network algorithm or the you only look once algorithm to recognize multiple obstacles in every image, and it subsequently sends the results back to the smartphone. The results of obstacle recognition in this study reached 60%, which is sufficient for assisting visually impaired people in realizing the types and locations of obstacles around them.

  20. Simple Smartphone-Based Guiding System for Visually Impaired People

    Directory of Open Access Journals (Sweden)

    Bor-Shing Lin

    2017-06-01

    Full Text Available Visually impaired people are often unaware of dangers in front of them, even in familiar environments. Furthermore, in unfamiliar environments, such people require guidance to reduce the risk of colliding with obstacles. This study proposes a simple smartphone-based guiding system for solving the navigation problems for visually impaired people and achieving obstacle avoidance to enable visually impaired people to travel smoothly from a beginning point to a destination with greater awareness of their surroundings. In this study, a computer image recognition system and smartphone application were integrated to form a simple assisted guiding system. Two operating modes, online mode and offline mode, can be chosen depending on network availability. When the system begins to operate, the smartphone captures the scene in front of the user and sends the captured images to the backend server to be processed. The backend server uses the faster region convolutional neural network algorithm or the you only look once algorithm to recognize multiple obstacles in every image, and it subsequently sends the results back to the smartphone. The results of obstacle recognition in this study reached 60%, which is sufficient for assisting visually impaired people in realizing the types and locations of obstacles around them.

  1. Visualizing project management: models and frameworks for mastering complex systems

    National Research Council Canada - National Science Library

    Forsberg, Kevin; Mooz, Hal; Cotterman, Howard

    2005-01-01

    ...- and beyond that on parameters such as return on investment, market acceptance, or sustainability. Anyone who has lived with the space program, or any other hightech industrial product development, can immediately appreciate this acclaimed book. It addresses and "visualizes" the multidimensional interactions of project management and systems engineering i...

  2. Audio-Visual Perception System for a Humanoid Robotic Head

    Directory of Open Access Journals (Sweden)

    Raquel Viciana-Abad

    2014-05-01

    Full Text Available One of the main issues within the field of social robotics is to endow robots with the ability to direct attention to people with whom they are interacting. Different approaches follow bio-inspired mechanisms, merging audio and visual cues to localize a person using multiple sensors. However, most of these fusion mechanisms have been used in fixed systems, such as those used in video-conference rooms, and thus, they may incur difficulties when constrained to the sensors with which a robot can be equipped. Besides, within the scope of interactive autonomous robots, there is a lack in terms of evaluating the benefits of audio-visual attention mechanisms, compared to only audio or visual approaches, in real scenarios. Most of the tests conducted have been within controlled environments, at short distances and/or with off-line performance measurements. With the goal of demonstrating the benefit of fusing sensory information with a Bayes inference for interactive robotics, this paper presents a system for localizing a person by processing visual and audio data. Moreover, the performance of this system is evaluated and compared via considering the technical limitations of unimodal systems. The experiments show the promise of the proposed approach for the proactive detection and tracking of speakers in a human-robot interactive framework.

  3. Real-time coloured visualization of phase flows by the schlieren method

    Science.gov (United States)

    Arbuzov, V. A.; Dubnistchev, Yu. N.

    1991-04-01

    A coloured real-time visualizer of optical inhomogeneities comprising a bichromatic schlieren system, video camera and colour monitor has been developed. The schlieren system represents a function Foucault-Hilbert transformation provided with an amplitude spatial frequency filter, or a quadrant Foucault knife edge. Two colour-coded complementary Toepler-grams are obtained in the exit plane of this schlieren system. Their summed image is then recorded by the video camera and displayed on the screen of the colour monitor. The schlieren photograph of internal gravity waves, generated by the cylindrical body motion in the reservoir filled with the stratified liquid, is presented.

  4. Visualizing Terrestrial and Aquatic Systems in 3D - in IEEE VisWeek 2014

    Science.gov (United States)

    The need for better visualization tools for environmental science is well documented, and the Visualization for Terrestrial and Aquatic Systems project (VISTAS) aims to both help scientists produce effective environmental science visualizations and to determine which visualizatio...

  5. Psychophysical research progress of interocular suppression in amblyopic visual system

    Directory of Open Access Journals (Sweden)

    Jing-Jing Li

    2016-03-01

    Full Text Available Some recent animal experiments and psychophysical studies indicate that patients with amblyopia have a structurally intact binocular visual system that is rendered functionally monocular due to suppression, and interocular suppression is a key mechanism in visual deficits experienced by patients with amblyopia. The aim of this review is to provide an overview of recent psychophysical findings that have investigated the important role of interocular suppression in amblyopia, the measurement and modulation of suppression, and new dichoptic treatment intervention that directly target suppression.

  6. Traffic Flow Wide-Area Surveillance system

    Energy Technology Data Exchange (ETDEWEB)

    Allgood, G.O.; Ferrell, R.K.; Kercel, S.W.; Abston, R.A.

    1994-09-01

    Traffic management can be thought of as a stochastic queuing process where the serving time at one of its control points is dynamically linked to the global traffic pattern, which is, in turn, dynamically linked to the control point. For this closed-loop system to be effective, the traffic management system must sense and interpret a large spatial projection of data originating from multiple sensor suites. This concept is the basis for the development of a Traffic Flow Wide-Area Surveillance (TFWAS) system. This paper presents the results of a study by Oak Ridge National Laboratory to define the operational specifications and characteristics, to determine the constraints, and to examine the state of technology of a TFWAS system in terms of traffic management and control. In doing so, the functions and attributes of a TFWAS system are mapped into an operational structure consistent with the Intelligent Vehicle Highway System (IVHS) concept and the existing highway infrastructure. This mapping includes identifying candidate sensor suites and establishing criteria, requirements, and performance measures by which these systems can be graded in their ability and practicality to meet the operational requirements of a TFWAS system. In light of this, issues such as system integration, applicable technologies, impact on traffic management and control, and public acceptance are addressed.

  7. Traffic flow wide-area surveillance system

    Science.gov (United States)

    Allgood, Glenn O.; Ferrell, Regina K.; Kercel, Stephen W.; Abston, Ruth A.

    1995-01-01

    Traffic management can be thought of as a stochastic queuing process where the serving time at one of its control points is dynamically linked to the global traffic pattern, which is, in turn, dynamically linked to the control point. For this closed-loop system to be effective, the traffic management system must sense and interpret a large spatial projection of data originating from multiple sensor suites. This concept is the basis for the development of a traffic flow wide-area surveillance (TFWAS) system. This paper presents the results of a study by Oak Ridge National Laboratory to define the operational specifications and characteristics, to determine the constraints, and to examine the state of technology of a TFWAS system in terms of traffic management and control. In doing so, the functions and attributes of a TFWAS system are mapped into an operational structure consistent with the Intelligent Vehicle Highway System (IVHS) concept and the existing highway infrastructure. This mapping includes identifying candidate sensor suites and establishing criteria, requirements, and performance measures by which these systems can be graded in their ability and practicality to meet the operational requirements of a TFWAS system. In light of this, issues such as system integration, applicable technologies, impact on traffic management and control, and public acceptance are addressed.

  8. Visual system evolution and the nature of the ancestral snake.

    Science.gov (United States)

    Simões, B F; Sampaio, F L; Jared, C; Antoniazzi, M M; Loew, E R; Bowmaker, J K; Rodriguez, A; Hart, N S; Hunt, D M; Partridge, J C; Gower, D J

    2015-07-01

    The dominant hypothesis for the evolutionary origin of snakes from 'lizards' (non-snake squamates) is that stem snakes acquired many snake features while passing through a profound burrowing (fossorial) phase. To investigate this, we examined the visual pigments and their encoding opsin genes in a range of squamate reptiles, focusing on fossorial lizards and snakes. We sequenced opsin transcripts isolated from retinal cDNA and used microspectrophotometry to measure directly the spectral absorbance of the photoreceptor visual pigments in a subset of samples. In snakes, but not lizards, dedicated fossoriality (as in Scolecophidia and the alethinophidian Anilius scytale) corresponds with loss of all visual opsins other than RH1 (λmax 490-497 nm); all other snakes (including less dedicated burrowers) also have functional sws1 and lws opsin genes. In contrast, the retinas of all lizards sampled, even highly fossorial amphisbaenians with reduced eyes, express functional lws, sws1, sws2 and rh1 genes, and most also express rh2 (i.e. they express all five of the visual opsin genes present in the ancestral vertebrate). Our evidence of visual pigment complements suggests that the visual system of stem snakes was partly reduced, with two (RH2 and SWS2) of the ancestral vertebrate visual pigments being eliminated, but that this did not extend to the extreme additional loss of SWS1 and LWS that subsequently occurred (probably independently) in highly fossorial extant scolecophidians and A. scytale. We therefore consider it unlikely that the ancestral snake was as fossorial as extant scolecophidians, whether or not the latter are para- or monophyletic. © 2015 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2015 European Society For Evolutionary Biology.

  9. Visual prosthesis wireless energy transfer system optimal modeling.

    Science.gov (United States)

    Li, Xueping; Yang, Yuan; Gao, Yong

    2014-01-16

    Wireless energy transfer system is an effective way to solve the visual prosthesis energy supply problems, theoretical modeling of the system is the prerequisite to do optimal energy transfer system design. On the basis of the ideal model of the wireless energy transfer system, according to visual prosthesis application condition, the system modeling is optimized. During the optimal modeling, taking planar spiral coils as the coupling devices between energy transmitter and receiver, the effect of the parasitic capacitance of the transfer coil is considered, and especially the concept of biological capacitance is proposed to consider the influence of biological tissue on the energy transfer efficiency, resulting in the optimal modeling's more accuracy for the actual application. The simulation data of the optimal model in this paper is compared with that of the previous ideal model, the results show that under high frequency condition, the parasitic capacitance of inductance and biological capacitance considered in the optimal model could have great impact on the wireless energy transfer system. The further comparison with the experimental data verifies the validity and accuracy of the optimal model proposed in this paper. The optimal model proposed in this paper has a higher theoretical guiding significance for the wireless energy transfer system's further research, and provide a more precise model reference for solving the power supply problem in visual prosthesis clinical application.

  10. Three-dimensional reconstruction and visualization system for medical images

    International Nuclear Information System (INIS)

    Preston, D.F.; Batnitzky, S.; Kyo Rak Lee; Cook, P.N.; Cook, L.T.; Dwyer, S.J.

    1982-01-01

    A three-dimensional reconstruction and visualization system could be of significant advantage in medical application such as neurosurgery and radiation treatment planning. The reconstructed anatomic structures from CT head scans could be used in a head stereotactic system to help plan the surgical procedure and the radiation treatment for a brain lesion. Also, the use of three-dimensional reconstruction algorithm provides for quantitative measures such as volume and surface area estimation of the anatomic features. This aspect of the three-dimensional reconstruction system may be used to monitor the progress or staging of a disease and the effects of patient treatment. Two cases are presented to illustrate the three-dimensional surface reconstruction and visualization system

  11. Visual perception system and method for a humanoid robot

    Science.gov (United States)

    Wells, James W. (Inventor); Mc Kay, Neil David (Inventor); Chelian, Suhas E. (Inventor); Linn, Douglas Martin (Inventor); Wampler, II, Charles W. (Inventor); Bridgwater, Lyndon (Inventor)

    2012-01-01

    A robotic system includes a humanoid robot with robotic joints each moveable using an actuator(s), and a distributed controller for controlling the movement of each of the robotic joints. The controller includes a visual perception module (VPM) for visually identifying and tracking an object in the field of view of the robot under threshold lighting conditions. The VPM includes optical devices for collecting an image of the object, a positional extraction device, and a host machine having an algorithm for processing the image and positional information. The algorithm visually identifies and tracks the object, and automatically adapts an exposure time of the optical devices to prevent feature data loss of the image under the threshold lighting conditions. A method of identifying and tracking the object includes collecting the image, extracting positional information of the object, and automatically adapting the exposure time to thereby prevent feature data loss of the image.

  12. Preprint WebVRGIS Based Traffic Analysis and Visualization System

    OpenAIRE

    Li, Xiaoming; Lv, Zhihan; Wang, Weixi; Zhang, Baoyun; Hu, Jinxing; Yin, Ling; Feng, Shengzhong

    2015-01-01

    This is the preprint version of our paper on Advances in Engineering Software. With several characteristics, such as large scale, diverse predictability and timeliness, the city traffic data falls in the range of definition of Big Data. A Virtual Reality GIS based traffic analysis and visualization system is proposed as a promising and inspiring approach to manage and develop traffic big data. In addition to the basic GIS interaction functions, the proposed system also includes some intellige...

  13. Soldier-worn augmented reality system for tactical icon visualization

    Science.gov (United States)

    Roberts, David; Menozzi, Alberico; Clipp, Brian; Russler, Patrick; Cook, James; Karl, Robert; Wenger, Eric; Church, William; Mauger, Jennifer; Volpe, Chris; Argenta, Chris; Wille, Mark; Snarski, Stephen; Sherrill, Todd; Lupo, Jasper; Hobson, Ross; Frahm, Jan-Michael; Heinly, Jared

    2012-06-01

    This paper describes the development and demonstration of a soldier-worn augmented reality system testbed that provides intuitive 'heads-up' visualization of tactically-relevant geo-registered icons. Our system combines a robust soldier pose estimation capability with a helmet mounted see-through display to accurately overlay geo-registered iconography (i.e., navigation waypoints, blue forces, aircraft) on the soldier's view of reality. Applied Research Associates (ARA), in partnership with BAE Systems and the University of North Carolina - Chapel Hill (UNC-CH), has developed this testbed system in Phase 2 of the DARPA ULTRA-Vis (Urban Leader Tactical, Response, Awareness, and Visualization) program. The ULTRA-Vis testbed system functions in unprepared outdoor environments and is robust to numerous magnetic disturbances. We achieve accurate and robust pose estimation through fusion of inertial, magnetic, GPS, and computer vision data acquired from helmet kit sensors. Icons are rendered on a high-brightness, 40°×30° field of view see-through display. The system incorporates an information management engine to convert CoT (Cursor-on-Target) external data feeds into mil-standard icons for visualization. The user interface provides intuitive information display to support soldier navigation and situational awareness of mission-critical tactical information.

  14. Visualization system on the earth simulator user's guide

    International Nuclear Information System (INIS)

    Muramatsu, Kazuhiro; Sai, Kazunori

    2002-08-01

    A visualization system on the Earth Simulator is developed. The system enables users to see a graphic representation of simulation results on a client terminal simultaneously with them being computed on the Earth Simulator. Moreover, the system makes it possible to change parameters of the calculation and its visualization in the middle of calculation. The graphical user interface (GUI) of the system is constructed on a Java applet. Consequently, the client only needs a web browser, so it is independent of operating systems. The system consists of a server function, post-processing function and client function. The server and post-processing functions work on the Earth Simulator, and the client function works on the client terminal. The server function employs a library style format so that users can easily invoke real-time visualization functions by applying their code. The post-processing function employs a library style format and moreover provides a load module. This report describes mainly the usage of the server and post-processing functions. (author)

  15. Quantitative flow visualization of fluidized-bed heat exchanger by neutron radiography

    International Nuclear Information System (INIS)

    Ozawa, M.; Umekawa, H.; Furui, S.; Hayashi, K.; Takenaka, N.

    2004-01-01

    Quantitative flow visualization of a gas-solid fluidized-bed installed vertical tube-bank has been successfully conducted using neutron radiography and image processing technique. The quantitative data of void fraction distribution as well as the fluctuation data are presented. The time-averaged void fraction is well correlated by the drift-flux model. The bubbles formed in the bed, rise along the vertical tubes and the observed bubble size is smaller than that in a free bubbling bed without tube-banks. The bubble diameter is well correlated by the modified Mori and Wen's correlation taking into account the pitch of tube arrangement. The bubble rise velocity is also well correlated by applying the drift-flux model. These results are consistent for both bed materials of Geldart's B- and A-particles, while the bubble size is significantly different between two kinds of particles

  16. Visualization of flowing current in braided carbon fiber reinforced plastics using SQUID gradiometer for nondestructive evaluation

    International Nuclear Information System (INIS)

    Hatsukade, Y; Yoshida, K; Kage, T; Tanaka, S; Takai, Y; Aly-Hassan, M S; Hamada, H; Nakai, A

    2013-01-01

    In this paper, visualization of flowing current in various braided carbon fiber reinforced plastics (CFRPs) was demonstrated using high-temperature superconductor (HTS) superconducting quantum interference device (SQUID) gradiometer, in order to study electrical properties and integrity of the braided CFRP samples. Step-by-step tensile loading was also applied to the samples, in order to study their mechanical properties and destructive mechanism. Experimental results indicated that the addition of carbon nano fibers and middle-end carbon fiber bundles attributed to modify not only the mechanical properties, but also the electrical properties of the samples. Combining the results by the both methods, a scenario of the destructive mechanism of one sample was estimated.

  17. Making Data Flow Diagrams Accessible for Visually Impaired Students Using Excel Tables

    Science.gov (United States)

    Sauter, Vicki L.

    2015-01-01

    This paper addresses the use of Excel tables to convey information to blind students that would otherwise be presented using graphical tools, such as Data Flow Diagrams. These tables can supplement diagrams in the classroom when introducing their use to understand the scope of a system and its main sub-processes, on exams when answering questions…

  18. Aqueous electrolytes for redox flow battery systems

    Science.gov (United States)

    Liu, Tianbiao; Li, Bin; Wei, Xiaoliang; Nie, Zimin; Wang, Wei; Liu, Jun; Sprenkle, Vincent L.

    2017-10-17

    An aqueous redox flow battery system includes an aqueous catholyte and an aqueous anolyte. The aqueous catholyte may comprise (i) an optionally substituted thiourea or a nitroxyl radical compound and (ii) a catholyte aqueous supporting solution. The aqueous anolyte may comprise (i) metal cations or a viologen compound and (ii) an anolyte aqueous supporting solution. The catholyte aqueous supporting solution and the anolyte aqueous supporting solution independently may comprise (i) a proton source, (ii) a halide source, or (iii) a proton source and a halide source.

  19. Flow visualization in superfluid helium-4 using He2 molecular tracers

    Science.gov (United States)

    Guo, Wei

    Flow visualization in superfluid helium is challenging, yet crucial for attaining a detailed understanding of quantum turbulence. Two problems have impeded progress: finding and introducing suitable tracers that are small yet visible; and unambiguous interpretation of the tracer motion. We show that metastable He2 triplet molecules are outstanding tracers compared with other particles used in helium. These molecular tracers have small size and relatively simple behavior in superfluid helium: they follow the normal fluid motion at above 1 K and will bind to quantized vortex lines below about 0.6 K. A laser-induced fluorescence technique has been developed for imaging the He2 tracers. We will present our recent experimental work on studying the normal-fluid motion by tracking thin lines of He2 tracers created via femtosecond laser-field ionization in helium. We will also discuss a newly launched experiment on visualizing vortex lines in a magnetically levitated superfluid helium drop by imaging the He2 tracers trapped on the vortex cores. This experiment will enable unprecedented insight into the behavior of a rotating superfluid drop and will untangle several key issues in quantum turbulence research. We acknowledge the support from the National Science Foundation under Grant No. DMR-1507386 and the US Department of Energy under Grant No. DE-FG02 96ER40952.

  20. Phase flow and statistical structure of Galton-board systems

    International Nuclear Information System (INIS)

    Lue, A.; Brenner, H.

    1993-01-01

    Galton boards, found in museum exhibits devoted to science and technology, are often used to demonstrate visually the ubiquity of so-called ''laws of probability'' via an experimental realization of normal distributions. A detailed theoretical study of Galton-board phase-space dynamics and statistical behavior is presented. The study is based on a simple inelastic-collision model employing a particle fall- ing through a spatially periodic lattice of rigid, convex scatterers. We show that such systems exhibit indeterminate behavior through the presence of strange attractors or strange repellers in phase space; nevertheless, we also show that these systems exhibit regular and predictable behavior under specific circumstances. Phase-space strange attractors, periodic attractors, and strange repellers are present in numerical simulations, confirming results anticipated from geometric analysis. The system's geometry (dictated by lattice geometry and density as well as the direction of gravity) is observed to play a dominant role in stability, phase-flow topology, and statistical observations. Smale horseshoes appear to exist in the low-lattice-density limit and may exist in other regimes. These horseshoes are generated by homoclinic orbits whose existence is dictated by system characteristics. The horseshoes lead directly to deterministic chaos in the system. Strong evidence exists for ergodicity in all attractors. Phase-space complexities are manifested at all observed levels, particularly statistical ones. Consequently, statistical observations are critically dependent upon system details. Under well-defined circumstances, these observations display behavior which does not constitute a realization of the ''laws of probability.''

  1. Laser sheet light flow visualization for evaluating room air flowsfrom Registers

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Iain S.; Claret, Valerie; Smith, Brian

    2006-04-01

    Forced air heating and cooling systems and whole house ventilation systems deliver air to individual rooms in a house via supply registers located on walls ceilings or floors; and occasionally less straightforward locations like toe-kicks below cabinets. Ideally, the air velocity out of the registers combined with the turbulence of the flow, vectoring of air by register vanes and geometry of register placement combine to mix the supply air within the room. A particular issue that has been raised recently is the performance of multiple capacity and air flow HVAC systems. These systems vary the air flow rate through the distribution system depending on the system load, or if operating in a ventilation rather than a space conditioning mode. These systems have been developed to maximize equipment efficiency, however, the high efficiency ratings do not include any room mixing effects. At lower air flow rates, there is the possibility that room air will be poorly mixed, leading to thermal stratification and reduced comfort for occupants. This can lead to increased energy use as the occupants adjust the thermostat settings to compensate and parts of the conditioned space have higher envelope temperature differences than for the well mixed case. In addition, lack of comfort can be a barrier to market acceptance of these higher efficiency systems To investigate the effect on room mixing of reduced air flow rates requires the measurement of mixing of supply air with room air throughout the space to be conditioned. This is a particularly difficult exercise if we want to determine the transient performance of the space conditioning system. Full scale experiments can be done in special test chambers, but the spatial resolution required to fully examine the mixing problem is usually limited by the sheer number of thermal sensors required. Current full-scale laboratory testing is therefore severely limited in its resolution. As an alternative, we used a water-filled scale model

  2. An Indoor Navigation System for the Visually Impaired

    Directory of Open Access Journals (Sweden)

    Luis A. Guerrero

    2012-06-01

    Full Text Available Navigation in indoor environments is highly challenging for the severely visually impaired, particularly in spaces visited for the first time. Several solutions have been proposed to deal with this challenge. Although some of them have shown to be useful in real scenarios, they involve an important deployment effort or use artifacts that are not natural for blind users. This paper presents an indoor navigation system that was designed taking into consideration usability as the quality requirement to be maximized. This solution enables one to identify the position of a person and calculates the velocity and direction of his movements. Using this information, the system determines the user’s trajectory, locates possible obstacles in that route, and offers navigation information to the user. The solution has been evaluated using two experimental scenarios. Although the results are still not enough to provide strong conclusions, they indicate that the system is suitable to guide visually impaired people through an unknown built environment.

  3. An indoor navigation system for the visually impaired.

    Science.gov (United States)

    Guerrero, Luis A; Vasquez, Francisco; Ochoa, Sergio F

    2012-01-01

    Navigation in indoor environments is highly challenging for the severely visually impaired, particularly in spaces visited for the first time. Several solutions have been proposed to deal with this challenge. Although some of them have shown to be useful in real scenarios, they involve an important deployment effort or use artifacts that are not natural for blind users. This paper presents an indoor navigation system that was designed taking into consideration usability as the quality requirement to be maximized. This solution enables one to identify the position of a person and calculates the velocity and direction of his movements. Using this information, the system determines the user's trajectory, locates possible obstacles in that route, and offers navigation information to the user. The solution has been evaluated using two experimental scenarios. Although the results are still not enough to provide strong conclusions, they indicate that the system is suitable to guide visually impaired people through an unknown built environment.

  4. Ultrasound Vector Flow Imaging: Part I: Sequential Systems

    DEFF Research Database (Denmark)

    Jensen, Jørgen Arendt; Nikolov, Svetoslav Ivanov; Yu, Alfred C. H.

    2016-01-01

    , and variants of these. The review covers both 2-D and 3-D velocity estimation and gives a historical perspective on the development along with a summary of various vector flow visualization algorithms. The current state-of-the-art is explained along with an overview of clinical studies conducted and methods......The paper gives a review of the most important methods for blood velocity vector flow imaging (VFI) for conventional, sequential data acquisition. This includes multibeam methods, speckle tracking, transverse oscillation, color flow mapping derived vector flow imaging, directional beamforming...

  5. Control of District Heating System with Flow-dependent Delays

    DEFF Research Database (Denmark)

    Bendtsen, Jan Dimon; Ledesma, Jorge Val; Kallesøe, Carsten Skovmose

    2017-01-01

    All flow systems are subject to transport delays, which are governed by the flow rates in the system. When the flow rates themselves are control inputs, the system becomes subject to input-dependent state delays, which poses significant theoretical problems. In an earlier paper, we proposed...

  6. Development of real time visual evaluation system for sodium transient thermohydraulic experiments

    International Nuclear Information System (INIS)

    Tanigawa, Shingo

    1990-01-01

    A real time visual evaluation system, the Liquid Metal Visual Evaluation System (LIVES), has been developed for the Plant Dynamics Test Loop facility at O-arai Engineering Center. This facility is designed to provide sodium transient thermohydraulic experimental data not only in a fuel subassembly but also in a plant wide system simulating abnormal or accident conditions in liquid metal fast breeder reactors. Since liquid metal sodium is invisible, measurements to obtain experimental data are mainly conducted by numerous thermo couples installed at various locations in the test sections and the facility. The transient thermohydraulic phenomena are a result of complicated interactions among global and local scale three-dimensional phenomena, and short- and long-time scale phenomena. It is, therefore, difficult to grasp intuitively thermohydraulic behaviors and to observe accurately both temperature distribution and flow condition solely by digital data or various types of analog data in evaluating the experimental results. For effectively conducting sodium transient experiments and for making it possible to observe exactly thermohydraulic phenomena, the real time visualization technique for transient thermohydraulics has been developed using the latest Engineering Work Station. The system makes it possible to observe and compare instantly the experiment and analytical results while experiment or analysis is in progress. The results are shown by not only the time trend curves but also the graphic animations. This paper shows an outline of the system and sample applications of the system. (author)

  7. An alternating direction algorithm for two-phase flow visualization using gamma computed tomography.

    Science.gov (United States)

    Xue, Qian; Wang, Huaxiang; Cui, Ziqiang; Yang, Chengyi

    2012-12-01

    In order to build high-speed imaging systems with low cost and low radiation leakage, the number of radioactive sources and detectors in the multiphase flow computed tomography (CT) system has to be limited. Moreover, systematic and random errors are inevitable in practical applications. The limited and corrupted measurement data have made the tomographic inversion process the most critical part in multiphase flow CT. Although various iterative reconstruction algorithms have been developed based on least squares minimization, the imaging quality is still inadequate for the reconstruction of relatively complicated bubble flow. This paper extends an alternating direction method (ADM), which is originally proposed in compressed sensing, to image two-phase flow using a low-energy γ-CT system. An l(1) norm-based regularization technique is utilized to treat the ill-posedness of the inverse problem, and the image reconstruction model is reformulated into one having partially separable objective functions, thereafter a dual-based ADM is adopted to solve the resulting problem. The feasibility is demonstrated in prototype experiments. Comparisons between the ADM and the conventional iterative algorithms show that the former has obviously improved the space resolution in reasonable time.

  8. Impact of enhanced flow on the flow system and wastewater ...

    African Journals Online (AJOL)

    In this study, we estimated the impact of enhanced flow on shallow wetlands that receive major effluent discharge from an adjoining metropolitan city. The local people use the shallow wetlands for pisciculture. Beginning in 1998, the population of the city began to rise and the amount of effluent discharge increased.

  9. New classification system-based visual outcome in Eales′ disease

    Directory of Open Access Journals (Sweden)

    Saxena Sandeep

    2007-01-01

    Full Text Available Purpose: A retrospective tertiary care center-based study was undertaken to evaluate the visual outcome in Eales′ disease, based on a new classification system, for the first time. Materials and Methods: One hundred and fifty-nine consecutive cases of Eales′ disease were included. All the eyes were staged according to the new classification: Stage 1: periphlebitis of small (1a and large (1b caliber vessels with superficial retinal hemorrhages; Stage 2a: capillary non-perfusion, 2b: neovascularization elsewhere/of the disc; Stage 3a: fibrovascular proliferation, 3b: vitreous hemorrhage; Stage 4a: traction/combined rhegmatogenous retinal detachment and 4b: rubeosis iridis, neovascular glaucoma, complicated cataract and optic atrophy. Visual acuity was graded as: Grade I 20/20 or better; Grade II 20/30 to 20/40; Grade III 20/60 to 20/120 and Grade IV 20/200 or worse. All the cases were managed by medical therapy, photocoagulation and/or vitreoretinal surgery. Visual acuity was converted into decimal scale, denoting 20/20=1 and 20/800=0.01. Paired t-test / Wilcoxon signed-rank tests were used for statistical analysis. Results: Vitreous hemorrhage was the commonest presenting feature (49.32%. Cases with Stages 1 to 3 and 4a and 4b achieved final visual acuity ranging from 20/15 to 20/40; 20/80 to 20/400 and 20/200 to 20/400, respectively. Statistically significant improvement in visual acuities was observed in all the stages of the disease except Stages 1a and 4b. Conclusion: Significant improvement in visual acuities was observed in the majority of stages of Eales′ disease following treatment. This study adds further to the little available evidences of treatment effects in literature and may have effect on patient care and health policy in Eales′ disease.

  10. Experimental analysis and flow visualization of a thin liquid film on a stationary and rotating disk

    Science.gov (United States)

    Thomas, S.; Faghri, A.; Hankey, W.

    1991-01-01

    The mean thickness of a thin liquid film of deionized water with a free surface on a stationary and rotating horizontal disk has been measured with a nonobtrusive capacitance technique. The measurements were taken when the rotational speed ranged from 0-300 rpm and the flow rate varied from 7.0-15.0 lpm. A flow visualization study of the thin film was also performed to determine the characteristics of the waves on the free surface. When the disk was stationary, a circular hydraulic jump was present on the disk. Upstream from the jump, the film thickness was determined by the inertial and frictional forces on the fluid, and the radial spreading of the film. The surface tension at the edge of the disk affected the film thickness downstream from the jump. For the rotating disk, the film thickness was dependent upon the inertial and frictional forces near the center of the disk and the centrifugal forces near the edge of the disk.

  11. Distribution in flowing reaction-diffusion systems

    KAUST Repository

    Kamimura, Atsushi; Herrmann, Hans J.; Ito, Nobuyasu

    2009-01-01

    A power-law distribution is found in the density profile of reacting systems A+B→C+D and 2A→2C under a flow in two and three dimensions. Different densities of reactants A and B are fixed at both ends. For the reaction A+B, the concentration of reactants asymptotically decay in space as x-1/2 and x-3/4 in two dimensions and three dimensions, respectively. For 2A, it decays as log (x) /x in two dimensions. The decay of A+B is explained considering the effect of segregation of reactants in the isotropic case. The decay for 2A is explained by the marginal behavior of two-dimensional diffusion. A logarithmic divergence of the diffusion constant with system size is found in two dimensions. © 2009 The American Physical Society.

  12. Distribution in flowing reaction-diffusion systems

    KAUST Repository

    Kamimura, Atsushi

    2009-12-28

    A power-law distribution is found in the density profile of reacting systems A+B→C+D and 2A→2C under a flow in two and three dimensions. Different densities of reactants A and B are fixed at both ends. For the reaction A+B, the concentration of reactants asymptotically decay in space as x-1/2 and x-3/4 in two dimensions and three dimensions, respectively. For 2A, it decays as log (x) /x in two dimensions. The decay of A+B is explained considering the effect of segregation of reactants in the isotropic case. The decay for 2A is explained by the marginal behavior of two-dimensional diffusion. A logarithmic divergence of the diffusion constant with system size is found in two dimensions. © 2009 The American Physical Society.

  13. A visual representation system for the scheduling and management of projects

    NARCIS (Netherlands)

    Pollalis, S.N.

    1992-01-01

    A VISUAL SCHEDULING AND MANAGEMENT SYSTEM (VSMS) This work proposes a new system for the visual representation of projects that displays the quantities of work, resources and cost. This new system, called Visual Scheduling and Management System, has a built-in hierarchical system to provide

  14. Flow visualization study of two-phase flow in the horizontal annulus of the fuel-channel outlet end-fitting of a CANDU reactor

    International Nuclear Information System (INIS)

    Supa-Amornkul, S.; Steward, F.R.; Lister, D.H.

    2005-01-01

    In CANDU-6 reactors, the pressurized hightemperature coolant flows through 380 fuel channels passing horizontally through the core. In 1996, higher than expected rates of wall thinning of the outlet feeders were ascribed to flow-accelerated corrosion (FAC). Such corrosion is strongly influenced by the hydrodynamics of the coolant. Results of preliminary flow visualization and modelling studies have suggested that flow conditions in the end-fitting annulus upstream of the outlet feeder may influence the pattern of FAC. For a full-scale flow visualization, an acrylic test section was built to simulate the cylindrical end-fitting with its annulus flow path. The tests were performed with water and air at atmospheric pressure and room temperature. The phase distribution along the length of the annulus was recorded with a digital video recorder. Size, concentration and velocity of the air bubbles at particular locations were studied with a high-speed digital still camera and a high-speed digital video camera. Phase distributions and variations in bubble size with velocity were determined. Significant effects on the flow patterns of spacer buttons in the annulus were observed. A commercial computational fluid dynamics (CFD) code-Fluent 6.1-was used to model the results. (authors)

  15. Sensory system plasticity in a visually specialized, nocturnal spider.

    Science.gov (United States)

    Stafstrom, Jay A; Michalik, Peter; Hebets, Eileen A

    2017-04-21

    The interplay between an animal's environmental niche and its behavior can influence the evolutionary form and function of its sensory systems. While intraspecific variation in sensory systems has been documented across distant taxa, fewer studies have investigated how changes in behavior might relate to plasticity in sensory systems across developmental time. To investigate the relationships among behavior, peripheral sensory structures, and central processing regions in the brain, we take advantage of a dramatic within-species shift of behavior in a nocturnal, net-casting spider (Deinopis spinosa), where males cease visually-mediated foraging upon maturation. We compared eye diameters and brain region volumes across sex and life stage, the latter through micro-computed X-ray tomography. We show that mature males possess altered peripheral visual morphology when compared to their juvenile counterparts, as well as juvenile and mature females. Matching peripheral sensory structure modifications, we uncovered differences in relative investment in both lower-order and higher-order processing regions in the brain responsible for visual processing. Our study provides evidence for sensory system plasticity when individuals dramatically change behavior across life stages, uncovering new avenues of inquiry focusing on altered reliance of specific sensory information when entering a new behavioral niche.

  16. Static and Dynamic Flow Visualization Studies of Two Double-Delta Wing Models at High Angles of Attack

    Science.gov (United States)

    1992-03-01

    body, ft U.= free-stream velocity, ft/sec In the case of a wing pitching about its mid-chord location, it can be interpreted as the ratio of the...Over Moderately Swept Delta Wings," HTP -5 Workshop On Vortical Flow Breakdown and Structural Interactions, NASA Langley Research Center, August 15-16...January 6- 9,1992/Reno,Nevada. 18. User’s Manual , Flow Visualization Water Tunnel Operation for Model 1520, Eidelic International, Inc., Torrance

  17. Efficient in-situ visualization of unsteady flows in climate simulation

    Science.gov (United States)

    Vetter, Michael; Olbrich, Stephan

    2017-04-01

    The simulation of climate data tends to produce very large data sets, which hardly can be processed in classical post-processing visualization applications. Typically, the visualization pipeline consisting of the processes data generation, visualization mapping and rendering is distributed into two parts over the network or separated via file transfer. Within most traditional post-processing scenarios the simulation is done on a supercomputer whereas the data analysis and visualization is done on a graphics workstation. That way temporary data sets with huge volume have to be transferred over the network, which leads to bandwidth bottlenecks and volume limitations. The solution to this issue is the avoidance of temporary storage, or at least significant reduction of data complexity. Within the Climate Visualization Lab - as part of the Cluster of Excellence "Integrated Climate System Analysis and Prediction" (CliSAP) at the University of Hamburg, in cooperation with the German Climate Computing Center (DKRZ) - we develop and integrate an in-situ approach. Our software framework DSVR is based on the separation of the process chain between the mapping and the rendering processes. It couples the mapping process directly to the simulation by calling methods of a parallelized data extraction library, which create a time-based sequence of geometric 3D scenes. This sequence is stored on a special streaming server with an interactive post-filtering option and then played-out asynchronously in a separate 3D viewer application. Since the rendering is part of this viewer application, the scenes can be navigated interactively. In contrast to other in-situ approaches where 2D images are created as part of the simulation or synchronous co-visualization takes place, our method supports interaction in 3D space and in time, as well as fixed frame rates. To integrate in-situ processing based on our DSVR framework and methods in the ICON climate model, we are continuously evolving

  18. Improving Software Systems By Flow Control Analysis

    Directory of Open Access Journals (Sweden)

    Piotr Poznanski

    2012-01-01

    Full Text Available Using agile methods during the implementation of the system that meets mission critical requirements can be a real challenge. The change in the system built of dozens or even hundreds of specialized devices with embedded software requires the cooperation of a large group of engineers. This article presents a solution that supports parallel work of groups of system analysts and software developers. Deployment of formal rules to the requirements written in natural language enables using formal analysis of artifacts being a bridge between software and system requirements. Formalism and textual form of requirements allowed the automatic generation of message flow graph for the (sub system, called the “big-picture-model”. Flow diagram analysis helped to avoid a large number of defects whose repair cost in extreme cases could undermine the legitimacy of agile methods in projects of this scale. Retrospectively, a reduction of technical debt was observed. Continuous analysis of the “big picture model” improves the control of the quality parameters of the software architecture. The article also tries to explain why the commercial platform based on UML modeling language may not be sufficient in projects of this complexity.

  19. A water flow calorimeter calibration system

    International Nuclear Information System (INIS)

    Ullrich, F.T.

    1983-01-01

    Neutral beam systems are instrumented by several water flow calorimeter systems, and some means is needed to verify the accuracy of such systems and diagnose their failures. This report describes a calibration system for these calorimeters. The calibrator consists of two 24 kilowatt circulation water heaters, with associated controls and instrumentation. The unit can supply power from 0 to 48 kW in five coarse steps and one fine range. Energy is controlled by varying the power and the time of operation of the heaters. The power is measured by means of precision power transducers, and the energy is measured by integrating the power with respect to time. The accuracy of the energy measurement is better than 0.5% when the power supplied is near full scale, and the energy resolution is better than 1 kilojoule. The maximum energy delivered is approximately 50 megajoules. The calorimetry loop to be calibrated is opened, and the calibrator is put in series with the calorimeter heat source. The calorimeter is then operated in its normal fashion, with the calibrator used as the heat source. The calibrator can also be used in a stand alone mode to calibrate calorimeter sensors removed from systems

  20. Thaw flow control for liquid heat transport systems

    Science.gov (United States)

    Kirpich, Aaron S.

    1989-01-01

    In a liquid metal heat transport system including a source of thaw heat for use in a space reactor power system, the thaw flow throttle or control comprises a fluid passage having forward and reverse flow sections and a partition having a plurality of bleed holes therein to enable fluid flow between the forward and reverse sections. The flow throttle is positioned in the system relatively far from the source of thaw heat.

  1. User-assisted video segmentation system for visual communication

    Science.gov (United States)

    Wu, Zhengping; Chen, Chun

    2002-01-01

    Video segmentation plays an important role for efficient storage and transmission in visual communication. In this paper, we introduce a novel video segmentation system using point tracking and contour formation techniques. Inspired by the results from the study of the human visual system, we intend to solve the video segmentation problem into three separate phases: user-assisted feature points selection, feature points' automatic tracking, and contour formation. This splitting relieves the computer of ill-posed automatic segmentation problems, and allows a higher level of flexibility of the method. First, the precise feature points can be found using a combination of user assistance and an eigenvalue-based adjustment. Second, the feature points in the remaining frames are obtained using motion estimation and point refinement. At last, contour formation is used to extract the object, and plus a point insertion process to provide the feature points for next frame's tracking.

  2. Aurally Aided Visual Search Performance Comparing Virtual Audio Systems

    DEFF Research Database (Denmark)

    Larsen, Camilla Horne; Lauritsen, David Skødt; Larsen, Jacob Junker

    2014-01-01

    Due to increased computational power, reproducing binaural hearing in real-time applications, through usage of head-related transfer functions (HRTFs), is now possible. This paper addresses the differences in aurally-aided visual search performance between a HRTF enhanced audio system (3D) and an...... with white dots. The results indicate that 3D audio yields faster search latencies than panning audio, especially with larger amounts of distractors. The applications of this research could fit virtual environments such as video games or virtual simulations.......Due to increased computational power, reproducing binaural hearing in real-time applications, through usage of head-related transfer functions (HRTFs), is now possible. This paper addresses the differences in aurally-aided visual search performance between a HRTF enhanced audio system (3D...

  3. Aurally Aided Visual Search Performance Comparing Virtual Audio Systems

    DEFF Research Database (Denmark)

    Larsen, Camilla Horne; Lauritsen, David Skødt; Larsen, Jacob Junker

    2014-01-01

    Due to increased computational power reproducing binaural hearing in real-time applications, through usage of head-related transfer functions (HRTFs), is now possible. This paper addresses the differences in aurally-aided visual search performance between an HRTF enhanced audio system (3D) and an...... with white dots. The results indicate that 3D audio yields faster search latencies than panning audio, especially with larger amounts of distractors. The applications of this research could fit virtual environments such as video games or virtual simulations.......Due to increased computational power reproducing binaural hearing in real-time applications, through usage of head-related transfer functions (HRTFs), is now possible. This paper addresses the differences in aurally-aided visual search performance between an HRTF enhanced audio system (3D...

  4. Intelligent Data Visualization for Cross-Checking Spacecraft System Diagnosis

    Science.gov (United States)

    Ong, James C.; Remolina, Emilio; Breeden, David; Stroozas, Brett A.; Mohammed, John L.

    2012-01-01

    Any reasoning system is fallible, so crew members and flight controllers must be able to cross-check automated diagnoses of spacecraft or habitat problems by considering alternate diagnoses and analyzing related evidence. Cross-checking improves diagnostic accuracy because people can apply information processing heuristics, pattern recognition techniques, and reasoning methods that the automated diagnostic system may not possess. Over time, cross-checking also enables crew members to become comfortable with how the diagnostic reasoning system performs, so the system can earn the crew s trust. We developed intelligent data visualization software that helps users cross-check automated diagnoses of system faults more effectively. The user interface displays scrollable arrays of timelines and time-series graphs, which are tightly integrated with an interactive, color-coded system schematic to show important spatial-temporal data patterns. Signal processing and rule-based diagnostic reasoning automatically identify alternate hypotheses and data patterns that support or rebut the original and alternate diagnoses. A color-coded matrix display summarizes the supporting or rebutting evidence for each diagnosis, and a drill-down capability enables crew members to quickly view graphs and timelines of the underlying data. This system demonstrates that modest amounts of diagnostic reasoning, combined with interactive, information-dense data visualizations, can accelerate system diagnosis and cross-checking.

  5. Advanced 3D Sensing and Visualization System for Unattended Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, J.J.; Little, C.Q.; Nelson, C.L.

    1999-01-01

    The purpose of this project was to create a reliable, 3D sensing and visualization system for unattended monitoring. The system provides benefits for several of Sandia's initiatives including nonproliferation, treaty verification, national security and critical infrastructure surety. The robust qualities of the system make it suitable for both interior and exterior monitoring applications. The 3D sensing system combines two existing sensor technologies in a new way to continuously maintain accurate 3D models of both static and dynamic components of monitored areas (e.g., portions of buildings, roads, and secured perimeters in addition to real-time estimates of the shape, location, and motion of humans and moving objects). A key strength of this system is the ability to monitor simultaneous activities on a continuous basis, such as several humans working independently within a controlled workspace, while also detecting unauthorized entry into the workspace. Data from the sensing system is used to identi~ activities or conditions that can signi~ potential surety (safety, security, and reliability) threats. The system could alert a security operator of potential threats or could be used to cue other detection, inspection or warning systems. An interactive, Web-based, 3D visualization capability was also developed using the Virtual Reality Modeling Language (VRML). The intex%ace allows remote, interactive inspection of a monitored area (via the Internet or Satellite Links) using a 3D computer model of the area that is rendered from actual sensor data.

  6. Automated visual inspection system based on HAVNET architecture

    Science.gov (United States)

    Burkett, K.; Ozbayoglu, Murat A.; Dagli, Cihan H.

    1994-10-01

    In this study, the HAusdorff-Voronoi NETwork (HAVNET) developed at the UMR Smart Engineering Systems Lab is tested in the recognition of mounted circuit components commonly used in printed circuit board assembly systems. The automated visual inspection system used consists of a CCD camera, a neural network based image processing software and a data acquisition card connected to a PC. The experiments are run in the Smart Engineering Systems Lab in the Engineering Management Dept. of the University of Missouri-Rolla. The performance analysis shows that the vision system is capable of recognizing different components under uncontrolled lighting conditions without being effected by rotation or scale differences. The results obtained are promising and the system can be used in real manufacturing environments. Currently the system is being customized for a specific manufacturing application.

  7. A Fresh Look at Spatio-Temporal Remote Sensing Data: Data Formats, Processing Flow, and Visualization

    Science.gov (United States)

    Gens, R.

    2017-12-01

    With increasing number of experimental and operational satellites in orbit, remote sensing based mapping and monitoring of the dynamic Earth has entered into the realm of `big data'. Just the Landsat series of satellites provide a near continuous archive of 45 years of data. The availability of such spatio-temporal datasets has created opportunities for long-term monitoring diverse features and processes operating on the Earth's terrestrial and aquatic systems. Processes such as erosion, deposition, subsidence, uplift, evapotranspiration, urbanization, land-cover regime shifts can not only be monitored and change can be quantified using time-series data analysis. This unique opportunity comes with new challenges in management, analysis, and visualization of spatio-temporal datasets. Data need to be stored in a user-friendly format, and relevant metadata needs to be recorded, to allow maximum flexibility for data exchange and use. Specific data processing workflows need to be defined to support time-series analysis for specific applications. Value-added data products need to be generated keeping in mind the needs of the end-users, and using best practices in complex data visualization. This presentation systematically highlights the various steps for preparing spatio-temporal remote sensing data for time series analysis. It showcases a prototype workflow for remote sensing based change detection that can be generically applied while preserving the application-specific fidelity of the datasets. The prototype includes strategies for visualizing change over time. This has been exemplified using a time-series of optical and SAR images for visualizing the changing glacial, coastal, and wetland landscapes in parts of Alaska.

  8. Designing visual displays and system models for safe reactor operations

    Energy Technology Data Exchange (ETDEWEB)

    Brown-VanHoozer, S.A.

    1995-12-31

    The material presented in this paper is based on two studies involving the design of visual displays and the user`s prospective model of a system. The studies involve a methodology known as Neuro-Linguistic Programming and its use in expanding design choices from the operator`s perspective image. The contents of this paper focuses on the studies and how they are applicable to the safety of operating reactors.

  9. Designing visual displays and system models for safe reactor operations

    International Nuclear Information System (INIS)

    Brown-VanHoozer, S.A.

    1995-01-01

    The material presented in this paper is based on two studies involving the design of visual displays and the user's prospective model of a system. The studies involve a methodology known as Neuro-Linguistic Programming and its use in expanding design choices from the operator's perspective image. The contents of this paper focuses on the studies and how they are applicable to the safety of operating reactors

  10. Urban Space Explorer: A Visual Analytics System for Urban Planning.

    Science.gov (United States)

    Karduni, Alireza; Cho, Isaac; Wessel, Ginette; Ribarsky, William; Sauda, Eric; Dou, Wenwen

    2017-01-01

    Understanding people's behavior is fundamental to many planning professions (including transportation, community development, economic development, and urban design) that rely on data about frequently traveled routes, places, and social and cultural practices. Based on the results of a practitioner survey, the authors designed Urban Space Explorer, a visual analytics system that utilizes mobile social media to enable interactive exploration of public-space-related activity along spatial, temporal, and semantic dimensions.

  11. A Visual-Aided Inertial Navigation and Mapping System

    Directory of Open Access Journals (Sweden)

    Rodrigo Munguía

    2016-05-01

    Full Text Available State estimation is a fundamental necessity for any application involving autonomous robots. This paper describes a visual-aided inertial navigation and mapping system for application to autonomous robots. The system, which relies on Kalman filtering, is designed to fuse the measurements obtained from a monocular camera, an inertial measurement unit (IMU and a position sensor (GPS. The estimated state consists of the full state of the vehicle: the position, orientation, their first derivatives and the parameter errors of the inertial sensors (i.e., the bias of gyroscopes and accelerometers. The system also provides the spatial locations of the visual features observed by the camera. The proposed scheme was designed by considering the limited resources commonly available in small mobile robots, while it is intended to be applied to cluttered environments in order to perform fully vision-based navigation in periods where the position sensor is not available. Moreover, the estimated map of visual features would be suitable for multiple tasks: i terrain analysis; ii three-dimensional (3D scene reconstruction; iii localization, detection or perception of obstacles and generating trajectories to navigate around these obstacles; and iv autonomous exploration. In this work, simulations and experiments with real data are presented in order to validate and demonstrate the performance of the proposal.

  12. Candidate glutamatergic neurons in the visual system of Drosophila.

    Directory of Open Access Journals (Sweden)

    Shamprasad Varija Raghu

    Full Text Available The visual system of Drosophila contains approximately 60,000 neurons that are organized in parallel, retinotopically arranged columns. A large number of these neurons have been characterized in great anatomical detail. However, studies providing direct evidence for synaptic signaling and the neurotransmitter used by individual neurons are relatively sparse. Here we present a first layout of neurons in the Drosophila visual system that likely release glutamate as their major neurotransmitter. We identified 33 different types of neurons of the lamina, medulla, lobula and lobula plate. Based on the previous Golgi-staining analysis, the identified neurons are further classified into 16 major subgroups representing lamina monopolar (L, transmedullary (Tm, transmedullary Y (TmY, Y, medulla intrinsic (Mi, Mt, Pm, Dm, Mi Am, bushy T (T, translobula plate (Tlp, lobula intrinsic (Lcn, Lt, Li, lobula plate tangential (LPTCs and lobula plate intrinsic (LPi cell types. In addition, we found 11 cell types that were not described by the previous Golgi analysis. This classification of candidate glutamatergic neurons fosters the future neurogenetic dissection of information processing in circuits of the fly visual system.

  13. A computer graphics system for visualizing spacecraft in orbit

    Science.gov (United States)

    Eyles, Don E.

    1989-01-01

    To carry out unanticipated operations with resources already in space is part of the rationale for a permanently manned space station in Earth orbit. The astronauts aboard a space station will require an on-board, spatial display tool to assist the planning and rehearsal of upcoming operations. Such a tool can also help astronauts to monitor and control such operations as they occur, especially in cases where first-hand visibility is not possible. A computer graphics visualization system designed for such an application and currently implemented as part of a ground-based simulation is described. The visualization system presents to the user the spatial information available in the spacecraft's computers by drawing a dynamic picture containing the planet Earth, the Sun, a star field, and up to two spacecraft. The point of view within the picture can be controlled by the user to obtain a number of specific visualization functions. The elements of the display, the methods used to control the display's point of view, and some of the ways in which the system can be used are described.

  14. Designing and visualizing the water-energy-food nexus system

    Science.gov (United States)

    Endo, A.; Kumazawa, T.; Yamada, M.; Kato, T.

    2017-12-01

    The objective of this study is to design and visualize a water-energy-food nexus system to identify the interrelationships between water-energy-food (WEF) resources and to understand the subsequent complexity of WEF nexus systems holistically, taking an interdisciplinary approach. Object-oriented concepts and ontology engineering methods were applied according to the hypothesis that the chains of changes in linkages between water, energy, and food resources holistically affect the water-energy-food nexus system, including natural and social systems, both temporally and spatially. The water-energy-food nexus system that is developed is significant because it allows us to: 1) visualize linkages between water, energy, and food resources in social and natural systems; 2) identify tradeoffs between these resources; 3) find a way of using resources efficiently or enhancing the synergy between the utilization of different resources; and 4) aid scenario planning using economic tools. The paper also discusses future challenges for applying the developed water-energy-food nexus system in other areas.

  15. Mean Flow Augmented Acoustics in Rocket Systems

    Science.gov (United States)

    Fischbach, Sean R.

    2014-01-01

    Oscillatory motion in solid rocket motors and liquid engines has long been a subject of concern. Many rockets display violent fluctuations in pressure, velocity, and temperature originating from the complex interactions between the combustion process and gas dynamics. The customary approach to modeling acoustic waves inside a rocket chamber is to apply the classical inhomogeneous wave equation to the combustion gas. The assumption of a linear, non-dissipative wave in a quiescent fluid remains valid while the acoustic amplitudes are small and local gas velocities stay below Mach 0.2. The converging section of a rocket nozzle, where gradients in pressure, density, and velocity become large, is a notable region where this approach is not applicable. The expulsion of unsteady energy through the nozzle of a rocket is identified as the predominate source of acoustic damping for most rocket systems. An accurate model of the acoustic behavior within this region where acoustic modes are influenced by the presence of a steady mean flow is required for reliable stability predictions. Recently, an approach to address nozzle damping with mean flow effects was implemented by French [1]. This new approach extends the work originated by Sigman and Zinn [2] by solving the acoustic velocity potential equation (AVPE) formulated by perturbing the Euler equations [3]. The acoustic velocity potential (psi) describing the acoustic wave motion in the presence of an inhomogeneous steady high-speed flow is defined by, (del squared)(psi) - (lambda/c)(exp 2)(psi) - M(dot)[M(dot)(del)(del(psi))] - 2(lambda(M/c) + (M(dot)del(M))(dot)del(psi)-2(lambda)(psi)[M(dot)del(1/c)]=0 (1) with M as the Mach vector, c as the speed of sound, and lambda as the complex eigenvalue. French apply the finite volume method to solve the steady flow field within the combustion chamber and nozzle with inviscid walls. The complex eigenvalues and eigenvector are determined with the use of the ARPACK eigensolver. The

  16. Visual Peoplemeter: A Vision-based Television Audience Measurement System

    Directory of Open Access Journals (Sweden)

    SKELIN, A. K.

    2014-11-01

    Full Text Available Visual peoplemeter is a vision-based measurement system that objectively evaluates the attentive behavior for TV audience rating, thus offering solution to some of drawbacks of current manual logging peoplemeters. In this paper, some limitations of current audience measurement system are reviewed and a novel vision-based system aiming at passive metering of viewers is prototyped. The system uses camera mounted on a television as a sensing modality and applies advanced computer vision algorithms to detect and track a person, and to recognize attentional states. Feasibility of the system is evaluated on a secondary dataset. The results show that the proposed system can analyze viewer's attentive behavior, therefore enabling passive estimates of relevant audience measurement categories.

  17. Liquid-Metal/Water Direct Contact Heat Exchange: Flow Visualization, Flow Stability, and Heat Transfer Using Real-Time X-Ray Imaging

    International Nuclear Information System (INIS)

    Abdulla, Sherif H.; Liu Xin; Anderson, Mark H.; Bonazza, Riccardo; Corradini, Michael L.; Cho, Dae; Page, Richard

    2005-01-01

    Advanced reactor system designs are being considered with liquid-metal cooling connected to a steam power cycle. In addition, current reactor safety systems are considering auxiliary cooling schemes that assure ex-vessel debris coolability utilizing direct water injection into molten material pools to achieve core quenching and eventual coolability. The phenomenon common in both applications is direct contact heat exchange. The current study focuses on detailed measurements of liquid-metal/water direct contact heat exchange that is directly applicable to improvements in effective heat transfer in devices that are being considered for both of these purposes.In this study, a test facility was designed at the University of Wisconsin-Madison to map the operating range of liquid-metal/water direct contact heat exchange. The test section (184-cm height, 45.75-cm width, and 10-cm depth) is a rectangular slice of a larger heat exchange device. This apparatus was used not only to provide measurements of integral thermal performance (i.e., volumetric heat transfer coefficient), but also local heat transfer coefficients in a bubbly flow regime with X-ray imaging based on measured parameters such as bubble formation time, bubble rise velocity, and bubble diameters.To determine these local heat transfer coefficients, a complete methodology of the X-ray radiography for two-phase flow measurement has been developed. With this methodology, a high-energy X-ray imaging system is optimized for our heat exchange experiments. With this real-time, large-area, high-energy X-ray imaging system, the two-phase flow was quantitatively visualized. An efficient image processing strategy was developed by combining several optimal digital image-processing algorithms into a software computational tool written in MATLAB called T-XIP. Time-dependent heat transfer-related variables such as bubble volumes and velocities, were determined. Finally, an error analysis associated with these measurements

  18. Ground-based PIV and numerical flow visualization results from the Surface Tension Driven Convection Experiment

    Science.gov (United States)

    Pline, Alexander D.; Werner, Mark P.; Hsieh, Kwang-Chung

    1991-01-01

    The Surface Tension Driven Convection Experiment (STDCE) is a Space Transportation System flight experiment to study both transient and steady thermocapillary fluid flows aboard the United States Microgravity Laboratory-1 (USML-1) Spacelab mission planned for June, 1992. One of the components of data collected during the experiment is a video record of the flow field. This qualitative data is then quantified using an all electric, two dimensional Particle Image Velocimetry (PIV) technique called Particle Displacement Tracking (PDT), which uses a simple space domain particle tracking algorithm. Results using the ground based STDCE hardware, with a radiant flux heating mode, and the PDT system are compared to numerical solutions obtained by solving the axisymmetric Navier Stokes equations with a deformable free surface. The PDT technique is successful in producing a velocity vector field and corresponding stream function from the raw video data which satisfactorily represents the physical flow. A numerical program is used to compute the velocity field and corresponding stream function under identical conditions. Both the PDT system and numerical results were compared to a streak photograph, used as a benchmark, with good correlation.

  19. Steady hydromagnetic Couette flow in a rotating system with ...

    African Journals Online (AJOL)

    International Journal of Engineering, Science and Technology ... Couette flow of class-II of a viscous incompressible electrically conducting fluid in a rotating system ... Heat transfer characteristics of the flow are considered taking viscous and ...

  20. Visual application of the American Board of Orthodontics Grading System.

    Science.gov (United States)

    Scott, Steven A; Freer, Terry J

    2005-05-01

    Assessment of treatment outcomes has traditionally been accomplished using the subjective opinion of experienced clinicians. Reduced subjectivity in the assessment of orthodontic treatment can be achieved with the use of an occlusal index. To implement an index for quality assurance purposes is time-consuming and subject to the inherent error of the index. Quality assessment of orthodontic treatment on a routine basis has been difficult to implement in private practice. To investigate whether a clinician can accurately apply the American Board of Orthodontics Objective Grading System by direct visual inspection instead of measuring individual traits. A random sample of 30 cases was selected, including pretreatment and post-treatment upper and lower study casts and panoramic radiographs. The cases were examined and scored with the standardized measuring gauge according to the protocol provided by the American Board of Orthodontics (ABO). The records were re-examined 6 weeks later and the individual traits scored by visual inspection (VI). There were no significant differences between the pre- and post-treatment ABO gauge and VI scores. This study suggests that occlusal traits defined by the ABO Objective Grading System can be accurately assessed by visual inspection. The VI score provides a simple and convenient method for critical evaluation of treatment outcome by a clinician.

  1. Direct encoding of orientation variance in the visual system.

    Science.gov (United States)

    Norman, Liam J; Heywood, Charles A; Kentridge, Robert W

    2015-01-01

    Our perception of regional irregularity, an example of which is orientation variance, seems effortless when we view two patches of texture that differ in this attribute. Little is understood, however, of how the visual system encodes a regional statistic like orientation variance, but there is some evidence to suggest that it is directly encoded by populations of neurons tuned broadly to high or low levels. The present study shows that selective adaptation to low or high levels of variance results in a perceptual aftereffect that shifts the perceived level of variance of a subsequently viewed texture in the direction away from that of the adapting stimulus (Experiments 1 and 2). Importantly, the effect is durable across changes in mean orientation, suggesting that the encoding of orientation variance is independent of global first moment orientation statistics (i.e., mean orientation). In Experiment 3 it was shown that the variance-specific aftereffect did not show signs of being encoded in a spatiotopic reference frame, similar to the equivalent aftereffect of adaptation to the first moment orientation statistic (the tilt aftereffect), which is represented in the primary visual cortex and exists only in retinotopic coordinates. Experiment 4 shows that a neuropsychological patient with damage to ventral areas of the cortex but spared intact early areas retains sensitivity to orientation variance. Together these results suggest that orientation variance is encoded directly by the visual system and possibly at an early cortical stage.

  2. Subjective visual vertical assessment with mobile virtual reality system

    Directory of Open Access Journals (Sweden)

    Ingrida Ulozienė

    Full Text Available Background and objective: The subjective visual vertical (SVV is a measure of a subject's perceived verticality, and a sensitive test of vestibular dysfunction. Despite this, and consequent upon technical and logistical limitations, SVV has not entered mainstream clinical practice. The aim of the study was to develop a mobile virtual reality based system for SVV test, evaluate the suitability of different controllers and assess the system's usability in practical settings. Materials and methods: In this study, we describe a novel virtual reality based system that has been developed to test SVV using integrated software and hardware, and report normative values across healthy population. Participants wore a mobile virtual reality headset in order to observe a 3D stimulus presented across separate conditions – static, dynamic and an immersive real-world (“boat in the sea” SVV tests. The virtual reality environment was controlled by the tester using a Bluetooth connected controllers. Participants controlled the movement of a vertical arrow using either a gesture control armband or a general-purpose gamepad, to indicate perceived verticality. We wanted to compare 2 different methods for object control in the system, determine normal values and compare them with literature data, to evaluate the developed system with the help of the system usability scale questionnaire and evaluate possible virtually induced dizziness with the help of subjective visual analog scale. Results: There were no statistically significant differences in SVV values during static, dynamic and virtual reality stimulus conditions, obtained using the two different controllers and the results are compared to those previously reported in the literature using alternative methodologies. The SUS scores for the system were high, with a median of 82.5 for the Myo controller and of 95.0 for the Gamepad controller, representing a statistically significant difference between the two

  3. 3-D steady analysis of flow in CRDM sewerage system

    International Nuclear Information System (INIS)

    Sun Yan; Liang Tiebo; Chen Zhihui; Zhao Jing; Zhang Yulong

    2014-01-01

    In order to obtain the flow state during sewer condition in Reactor and CRDM Sewerage system (RSE), this paper analyzes the 3-D steady flow in RSE by using Computational Fluid Dynamics (CFD) method. In the premise that the pressure drop of the RSE is known, the mass flow rate, the velocity and the type of flow in the system is obtained with the inverse method, which is proposed and validated to be applicable in the paper. The result shows that in the sewerage conditions, the type of flow in the RSE is turbulence flow, which is helpful to sewer drain. The study results give an reference for the design of RSE. (authors)

  4. Research on the Visual Processing System of the Punch Press

    Directory of Open Access Journals (Sweden)

    Sun Xuan

    2016-01-01

    Full Text Available Most of raw materials of small hardware processing for plate scraps, and it’s realized through the manual operation of ordinary punch, which way has the low production efficiency and the high labor intensity. In order to improve the automation level of production, developing and designing of a visual processing system for punch press manipulator which based on the MFC tools of Visual Studio software platform. Through the image acquisition and image processing, get the information about the board to be processed, such as shape, length, the center of gravity position and pose, and providing relevant parameters for positioning gripping and placing into the punch table positioning of the feeding manipulator and automatic programming of punching machine, so as to realize the automatic operation about press feeding and processing.

  5. Integrated and visual performance evaluation model for thermal systems and its application to an HTGR cogeneration system

    International Nuclear Information System (INIS)

    Qi, Zhang; Yoshikawa, Hidekazu; Ishii, Hirotake; Shimoda, Hiroshi

    2010-01-01

    An integrated and visual model EXCEM-MFM (EXergy, Cost, Energy and Mass - Multilevel Flow Model) has been proposed in this study to comprehensively analyze and evaluate the performances of thermal systems by coupling two models: EXCEM model and MFM. In the EXCEM-MFM model, MFM is used to provide analysis frameworks for exergy, cost, energy and mass four parameters, and EXCEM is used to calculate the flow values of these four parameters for MFM based on the provided framework. In this study, we used the tools and technologies of computer science and software engineering to materialize the model. Moreover, the feasibility and application potential of this proposed EXCEM-MFM model has been demonstrated by the example application of a comprehensive performance study of a typical High Temperature Gas Reactor (HTGR) cogeneration system by taking into account the thermodynamic and economic perspectives. (author)

  6. Visualization investigation of acoustic and flow-induced vibration in main stream lines using a high-time-resolved PIV technique

    International Nuclear Information System (INIS)

    Li, Yanrong; Someya, Satoshi; Okamoto, Koji

    2009-01-01

    Systems with closed side-branches are liable to an excitation of sound, as called cavity tone. It may occur in pipe branches leading to safety valves or to boiler relief valves. The outbreak mechanism of the cavity tone has been known by phase-averaged measurement in previous researches, while the relation between sound propagation and flow field is still unclear due to the difficulty of detecting instantaneous velocity field. High-time-resolved PIV has a possibility to analyze the velocity field and the relation mentioned above. In this study, flow-induced acoustic resonance of piping system containing closed side-branches was investigated experimentally. A high-time-resolved PIV technique was applied to measure a gas-flow in a cavity. Air flow containing oil mist as tracer particles was measured using a high frequency pulse laser and a high speed camera. The present investigation on the coaxial closed side-branches is the first rudimentary study to visualize the fluid flow two-dimensionally in the cross-section by using PIV and to measure the pressure at the downstream side opening of the cavity by microphone. The fluid flows at different points in the cavity interact with some phase differences and the relation was clarified. (author)

  7. Hanford Tank Farms Waste Feed Flow Loop Phase VI: PulseEcho System Performance Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Denslow, Kayte M.; Bontha, Jagannadha R.; Adkins, Harold E.; Jenks, Jeromy WJ; Hopkins, Derek F.

    2012-11-21

    This document presents the visual and ultrasonic PulseEcho critical velocity test results obtained from the System Performance test campaign that was completed in September 2012 with the Remote Sampler Demonstration (RSD)/Waste Feed Flow Loop cold-test platform located at the Monarch test facility in Pasco, Washington. This report is intended to complement and accompany the report that will be developed by WRPS on the design of the System Performance simulant matrix, the analysis of the slurry test sample concentration and particle size distribution (PSD) data, and the design and construction of the RSD/Waste Feed Flow Loop cold-test platform.

  8. System identification on two-phase flow stability

    International Nuclear Information System (INIS)

    Wu Shaorong; Zhang Youjie; Wang Dazhong; Bo Jinghai; Wang Fei

    1996-01-01

    The theoretical principle, experimental method and results of interrelation analysis identification for the instability of two-phase flow are described. A completely new concept of test technology and method on two-phase flow stability was developed by using he theory of information science on system stability and system identification for two-phase flow stability in thermo-physics field. Application of this method would make it possible to identify instability boundary of two-phase flow under stable operation conditions of two-phase flow system. The experiment was carried out on the thermohydraulic test system HRTL-5. Using reverse repeated pseudo-random sequences of heating power as input signal sources and flow rate as response function in the test, the two-phase flow stability and stability margin of the natural circulation system are investigated. The effectiveness and feasibility of identifying two-phase flow stability by using this system identification method were experimentally demonstrated. Basic data required for mathematics modeling of two-phase flow and analysis of two-phase flow stability were obtained, which are useful for analyzing, monitoring of the system operation condition, and forecasting of two-phase flow stability in engineering system

  9. Distributed Systems for Problems in Robust Control and Visual Tracking

    National Research Council Canada - National Science Library

    Tannenbaum, Allen

    2000-01-01

    .... A key application is in controlled active vision, including visual tracking, the control of autonomous vehicles, motion planning, and the utilization of visual information in guidance and control...

  10. Visualization for gas-liquid two-phase flow using wire mesh tomography

    International Nuclear Information System (INIS)

    Motegi, Yuichi; Wanjiraniran, Weerin; Kikura, Hiroshige; Aritomi, Masanori; Yamauchi, Toyoaki

    2003-01-01

    Wire Mesh Tomography (WMT), which is system to measure two-phase flow, has been developed in our laboratory. Measurement principle of WMT is detecting conductivity difference between gas and liquid. WMT measures void fraction as raw date, and calculates gas velocity and bubble volume etc. In this paper, this measurement technique was applied to vertical circular pipe of 50 mm diameter and about 7 m heights. New Wire Mesh Sensor (WMS), which is measurement part of WMT, for circular pipe, have been made. When experiment was performed, superficial gas and water velocity. The effect of each flow parameter was found for void fraction, true gas velocity and bubble volume and the results was in good agreement with the past research, qualitatively. (author)

  11. Novel simplified hourly energy flow models for photovoltaic power systems

    International Nuclear Information System (INIS)

    Khatib, Tamer; Elmenreich, Wilfried

    2014-01-01

    Highlights: • We developed an energy flow model for standalone PV system using MATLAB line code. • We developed an energy flow model for hybrid PV/wind system using MATLAB line code. • We developed an energy flow model for hybrid PV/diesel system using MATLAB line code. - Abstract: This paper presents simplified energy flow models for photovoltaic (PV) power systems using MATLAB. Three types of PV power system are taken into consideration namely standalone PV systems, hybrid PV/wind systems and hybrid PV/diesel systems. The logic of the energy flow for each PV power system is discussed first and then the MATLAB line codes for these models are provided and explained. The results prove the accuracy of the proposed models. Such models help modeling and sizing PV systems

  12. Review of hybrid laminar flow control systems

    Science.gov (United States)

    Krishnan, K. S. G.; Bertram, O.; Seibel, O.

    2017-08-01

    The aeronautic community always strived for fuel efficient aircraft and presently, the need for ecofriendly aircraft is even more, especially with the tremendous growth of air traffic and growing environmental concerns. Some of the important drivers for such interests include high fuel prices, less emissions requirements, need for more environment friendly aircraft to lessen the global warming effects. Hybrid laminar flow control (HLFC) technology is promising and offers possibility to achieve these goals. This technology was researched for decades for its application in transport aircraft, and it has achieved a new level of maturity towards integration and safety and maintenance aspects. This paper aims to give an overview of HLFC systems research and associated flight tests in the past years both in the US and in Europe. The review makes it possible to distinguish between the successful approaches and the less successful or outdated approaches in HLFC research. Furthermore, the technology status shall try to produce first estimations regarding the mass, power consumption and performance of HLFC systems as well as estimations regarding maintenance requirements and possible subsystem definitions.

  13. LOFT data acquisition and visual display system (DAVDS) presentation program

    International Nuclear Information System (INIS)

    Bullock, M.G.; Miyasaki, F.S.

    1976-03-01

    The Data Acquisition and Visual Display System (DAVDS) at the Loss-of-Fluid Test Facility (LOFT) has 742 data channel recording capability of which 576 are recorded digitally. The purpose of this computer program is to graphically present the data acquired and/or processed by the LOFT DAVDS. This program takes specially created plot data buffers of up to 1024 words and generates time history plots on the system electrostatic printer-plotter. The data can be extracted from two system input devices: Magnetic disk or digital magnetic tape. Versatility has been designed in the program by providing the user three methods of scaling plots: Automatic, control record, and manual. Time required to produce a plot on the system electrostatic printer-plotter varies from 30 to 90 seconds depending on the options selected. The basic computer and program details are described

  14. Scientific Visualization & Modeling for Earth Systems Science Education

    Science.gov (United States)

    Chaudhury, S. Raj; Rodriguez, Waldo J.

    2003-01-01

    Providing research experiences for undergraduate students in Earth Systems Science (ESS) poses several challenges at smaller academic institutions that might lack dedicated resources for this area of study. This paper describes the development of an innovative model that involves students with majors in diverse scientific disciplines in authentic ESS research. In studying global climate change, experts typically use scientific visualization techniques applied to remote sensing data collected by satellites. In particular, many problems related to environmental phenomena can be quantitatively addressed by investigations based on datasets related to the scientific endeavours such as the Earth Radiation Budget Experiment (ERBE). Working with data products stored at NASA's Distributed Active Archive Centers, visualization software specifically designed for students and an advanced, immersive Virtual Reality (VR) environment, students engage in guided research projects during a structured 6-week summer program. Over the 5-year span, this program has afforded the opportunity for students majoring in biology, chemistry, mathematics, computer science, physics, engineering and science education to work collaboratively in teams on research projects that emphasize the use of scientific visualization in studying the environment. Recently, a hands-on component has been added through science student partnerships with school-teachers in data collection and reporting for the GLOBE Program (GLobal Observations to Benefit the Environment).

  15. Head Worn Display System for Equivalent Visual Operations

    Science.gov (United States)

    Cupero, Frank; Valimont, Brian; Wise, John; Best. Carl; DeMers, Bob

    2009-01-01

    Head-Worn Displays or so-called, near-to-eye displays have potentially significant advantages in terms of cost, overcoming cockpit space constraints, and for the display of spatially-integrated information. However, many technical issues need to be overcome before these technologies can be successfully introduced into commercial aircraft cockpits. The results of three activities are reported. First, the near-to-eye display design, technological, and human factors issues are described and a literature review is presented. Second, the results of a fixed-base piloted simulation, investigating the impact of near to eye displays on both operational and visual performance is reported. Straight-in approaches were flown in simulated visual and instrument conditions while using either a biocular or a monocular display placed on either the dominant or non-dominant eye. The pilot's flight performance, visual acuity, and ability to detect unsafe conditions on the runway were tested. The data generally supports a monocular design with minimal impact due to eye dominance. Finally, a method for head tracker system latency measurement is developed and used to compare two different devices.

  16. New data visualization of the LHC Era Monitoring (Lemon) system

    International Nuclear Information System (INIS)

    Ivan, Fedorko; Veronique, Lefebure; Daniel, Lenkes; Omar, Pera Mira

    2012-01-01

    In the last few years, new requirements have been received for visualization of monitoring data: advanced graphics, flexibility in configuration and decoupling of the presentation layer from the monitoring repository. Lemonweb is the data visualization component of the LHC Era Monitoring (Lemon) system. Lemonweb consists of two subcomponents: a data collector and a web visualization interface. The data collector is a daemon, implemented in Python, responsible for data gathering from the central monitoring repository and storing into time series data structures. Data is stored on disk in Round Robin Database (RRD) files: one file per monitored entity, with set of entity related metrics. Entities may be grouped into a hierarchical structure, called “clusters” and supporting mathematical operations over entities and clusters (e.g. cluster A + cluster B /clusters C – entity XY). Using the configuration information, a cluster definition is evaluated in the collector engine and, at runtime, a sequence of data selects is built, to optimize access to the central monitoring repository. In this article, an overview of the design and architecture as well as highlights of some implemented features will be presented.

  17. ARM-based visual processing system for prosthetic vision.

    Science.gov (United States)

    Matteucci, Paul B; Byrnes-Preston, Philip; Chen, Spencer C; Lovell, Nigel H; Suaning, Gregg J

    2011-01-01

    A growing number of prosthetic devices have been shown to provide visual perception to the profoundly blind through electrical neural stimulation. These first-generation devices offer promising outcomes to those affected by degenerative disorders such as retinitis pigmentosa. Although prosthetic approaches vary in their placement of the stimulating array (visual cortex, optic-nerve, epi-retinal surface, sub-retinal surface, supra-choroidal space, etc.), most of the solutions incorporate an externally-worn device to acquire and process video to provide the implant with instructions on how to deliver electrical stimulation to the patient, in order to elicit phosphenized vision. With the significant increase in availability and performance of low power-consumption smart phone and personal device processors, the authors investigated the use of a commercially available ARM (Advanced RISC Machine) device as an externally-worn processing unit for a prosthetic neural stimulator for the retina. A 400 MHz Samsung S3C2440A ARM920T single-board computer was programmed to extract 98 values from a 1.3 Megapixel OV9650 CMOS camera using impulse, regional averaging and Gaussian sampling algorithms. Power consumption and speed of video processing were compared to results obtained to similar reported devices. The results show that by using code optimization, the system is capable of driving a 98 channel implantable device for the restoration of visual percepts to the blind.

  18. Fuel visual inspection system of the RTMIII; Sistema de inspeccion visual de combustible del RTMIII

    Energy Technology Data Exchange (ETDEWEB)

    Delfin L, A.; Castaneda J, G.; Mazon R, R.; Aguilar H, F. [ININ, Km. 36.5 Carretera Mexico-Toluca, Ocoyoacac, 52245 Estado de Mexico (Mexico)]. e-mail: rmr@nuclear.inin.mx

    2007-07-01

    The International Atomic Energy Agency (IAEA) through the RLA/04/18 project, Management of Irradiated Fuel in Research Reactors, it recommended among other that the participant countries (Brazil, Argentina, Chile, Peru and Mexico), develop tools to assure the integrity of the nuclear fuels used in the research reactors. The TRIGA Mark lll reactor (RTMIII) of the ININ, designed and built a system of visual inspection, that it uses a high radiation camera and image digitalisation. The project considers safety conditions of the personnel that carried out the activities of visual inspection, for that which the tool dives in the pool of the RTMIII, being held by an end in the superior part of the aluminium liner of the Reactor like it is shown in the plane No. 1. The primordial unit of the system is the visual equipment that corresponds to a camera of the Hydro-Technologie (HYTEC) VSLT 410N mark, designed to work in atmospheres under the water and/or in places of high risk. The camera has an unit of motorized orientation of stainless steel that can be rotated unboundedly in both senses, with variable speed by means of a control lever from the control unit. Together to this orientation unit is found the camera head, the one which is contained in an unit of motorized inclination of stainless steel that can be rotated azimuthally up to 370 degrees in both senses. The operation conditions of the camera are the following ones, temperature: 0 to 50 C, dose speed: {<=} 50 rad/h, operation depth: {<=} 30 mts, humidity (control unit): {<=} 80%. From the control unit it is derived an external device plug-n-play TV-Usb Aver Media marks whose function is to decode the video signal sent by the control unit and to transmit it to the computer where the image is captured in picture or video that is analyzed later on with any software ad hoc, that in our case we use the Quantikov Image Analyzer program for Windows 98 of the Dr. Lucio C. M. Pinto from Brazil who participates in the RLA

  19. Two-phase pressure drop and flow visualization of FC-72 in a silicon microchannel heat sink

    International Nuclear Information System (INIS)

    Megahed, Ayman; Hassan, Ibrahim

    2009-01-01

    The rapid development of two-phase microfluidic devices has triggered the demand for a detailed understanding of the flow characteristics inside microchannel heat sinks to advance the cooling process of micro-electronics. The present study focuses on the experimental investigation of pressure drop characteristics and flow visualization of a two-phase flow in a silicon microchannel heat sink. The microchannel heat sink consists of a rectangular silicon chip in which 45 rectangular microchannels were chemically etched with a depth of 276 μm, width of 225 μm, and a length of 16 mm. Experiments are carried out for mass fluxes ranging from 341 to 531 kg/m 2 s and heat fluxes from 60.4 to 130.6 kW/m 2 using FC-72 as the working fluid. Bubble growth and flow regimes are observed using high speed visualization. Three major flow regimes are identified: bubbly, slug, and annular. The frictional two-phase pressure drop increases with exit quality for a constant mass flux. An assessment of various pressure drop correlations reported in the literature is conducted for validation. A new general correlation is developed to predict the two-phase pressure drop in microchannel heat sinks for five different refrigerants. The experimental pressure drops for laminar-liquid laminar-vapor and laminar-liquid turbulent-vapor flow conditions are predicted by the new correlation with mean absolute errors of 10.4% and 14.5%, respectively.

  20. Volume Tracking: A new method for quantitative assessment and visualization of intracardiac blood flow from three-dimensional, time-resolved, three-component magnetic resonance velocity mapping

    International Nuclear Information System (INIS)

    Töger, Johannes; Carlsson, Marcus; Söderlind, Gustaf; Arheden, Håkan; Heiberg, Einar

    2011-01-01

    Functional and morphological changes of the heart influence blood flow patterns. Therefore, flow patterns may carry diagnostic and prognostic information. Three-dimensional, time-resolved, three-directional phase contrast cardiovascular magnetic resonance (4D PC-CMR) can image flow patterns with unique detail, and using new flow visualization methods may lead to new insights. The aim of this study is to present and validate a novel visualization method with a quantitative potential for blood flow from 4D PC-CMR, called Volume Tracking, and investigate if Volume Tracking complements particle tracing, the most common visualization method used today. Eight healthy volunteers and one patient with a large apical left ventricular aneurysm underwent 4D PC-CMR flow imaging of the whole heart. Volume Tracking and particle tracing visualizations were compared visually side-by-side in a visualization software package. To validate Volume Tracking, the number of particle traces that agreed with the Volume Tracking visualizations was counted and expressed as a percentage of total released particles in mid-diastole and end-diastole respectively. Two independent observers described blood flow patterns in the left ventricle using Volume Tracking visualizations. Volume Tracking was feasible in all eight healthy volunteers and in the patient. Visually, Volume Tracking and particle tracing are complementary methods, showing different aspects of the flow. When validated against particle tracing, on average 90.5% and 87.8% of the particles agreed with the Volume Tracking surface in mid-diastole and end-diastole respectively. Inflow patterns in the left ventricle varied between the subjects, with excellent agreement between observers. The left ventricular inflow pattern in the patient differed from the healthy subjects. Volume Tracking is a new visualization method for blood flow measured by 4D PC-CMR. Volume Tracking complements and provides incremental information compared to particle

  1. 3D visualization of two-phase flow in the micro-tube by a simple but effective method

    International Nuclear Information System (INIS)

    Fu, X; Zhang, P; Hu, H; Huang, C J; Huang, Y; Wang, R Z

    2009-01-01

    The present study provides a simple but effective method for 3D visualization of the two-phase flow in the micro-tube. An isosceles right-angle prism combined with a mirror located 45° bevel to the prism is employed to synchronously obtain the front and side views of the flow patterns with a single camera, where the locations of the prism and the micro-tube for clear imaging should satisfy a fixed relationship which is specified in the present study. The optical design is proven successfully by the tough visualization work at the cryogenic temperature range. The image deformation due to the refraction and geometrical configuration of the test section is quantitatively investigated. It is calculated that the image is enlarged by about 20% in inner diameter compared to the real object, which is validated by the experimental results. Meanwhile, the image deformation by adding a rectangular optical correction box outside the circular tube is comparatively investigated. It is calculated that the image is reduced by about 20% in inner diameter with a rectangular optical correction box compared to the real object. The 3D re-construction process based on the two views is conducted through three steps, which shows that the 3D visualization method can easily be applied for two-phase flow research in micro-scale channels and improves the measurement accuracy of some important parameters of the two-phase flow such as void fraction, spatial distribution of bubbles, etc

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

    International Nuclear Information System (INIS)

    Laan, Flavio T. van der; Sefidvash, Farhang; Cornelius, Vanderli

    2000-01-01

    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 studied. (author)

  3. COPASutils: an R package for reading, processing, and visualizing data from COPAS large-particle flow cytometers.

    Directory of Open Access Journals (Sweden)

    Tyler C Shimko

    Full Text Available The R package COPASutils provides a logical workflow for the reading, processing, and visualization of data obtained from the Union Biometrica Complex Object Parametric Analyzer and Sorter (COPAS or the BioSorter large-particle flow cytometers. Data obtained from these powerful experimental platforms can be unwieldy, leading to difficulties in the ability to process and visualize the data using existing tools. Researchers studying small organisms, such as Caenorhabditis elegans, Anopheles gambiae, and Danio rerio, and using these devices will benefit from this streamlined and extensible R package. COPASutils offers a powerful suite of functions for the rapid processing and analysis of large high-throughput screening data sets.

  4. Flow visualization on a natural circulation inter-wrapper flow. Experimental and numerical results under a geometric condition of button type spacer pads

    Energy Technology Data Exchange (ETDEWEB)

    Yasuda, A.; Miyakoshi, H.; Hayashi, K.; Nishimura, M.; Kamide, H.; Hishida, K. [Japan Nuclear Cycle Development Inst., Oarai, Ibaraki (Japan). Oarai Engineering Center

    1999-04-01

    Investigations on the inter-wrapper flow (IWF) in a liquid metal cooled fast breeder reactor core have been carried out. The IWF is a natural circulation flow between wrapper tubes in the core barrel where cold fluid is coming from a direct heat exchanger (DHX) in the upper plenum. It was shown by the sodium experiment using 7-subassembly core model that the IWF can cool the subassemblies. To clarify thermal-hydraulic characteristics of the IWF in the core, the water experiment was performed using the flow visualization technique. The test rig for IWF (TRIF) has the core simulating the fuel subassemblies and radial reflectors. The subassemblies are constructed featuring transparent heater to enable both Joule heating and flow visualization. The transparent heater was made of glass with thin conductor film coating of tin oxide, and the glass heater was embedded on the wall of modeled wrapper tube made of acrylic plexiglass. In the present experiment, influences of peripheral geometric parameters such as flow holes of core formers on the thermal-hydraulic field were investigated with the button type spacer pads of the wrapper tube. Through the water tests, flow patterns of the IWF were revealed and velocity fields were quantitatively measured with a particle image velocimetry (PIV). Also, no substantial influence of peripheral geometry was found on the temperature field of the IWF, as far as the button type spacer pad was applied. Numerical simulation was applied to the experimental analysis of IWF by using multidimensional code with porous body model. The numerical results reproduced the flow patterns within TRIF and agreed well to experimental temperature distributions, showing capability of predicting IWF with porous body model. (author)

  5. A visual retrieval environment for hypermedia information system

    Energy Technology Data Exchange (ETDEWEB)

    Lucarella, D; Zanzi, A [ENEL s.p.a., Centro Ricerca di Automatica, Cologno Monzese, Milan (Italy)

    1995-03-01

    The authors a graph-based object model that may be used as a uniform framework for direct manipulation of multimedia information. After an introduction motivating the need for abstraction and structuring mechanisms in hypermedia systems, the authors introduce the data model and the notion of perspective, a form of data abstraction that acts as a user interface to the system, providing control over the visibility of the objects and their properties. A perspective is defined to include an intention and an extension. The authors present a visual retrieval environment that effectively combines filtering, browsing, and navigation to provide an integrated view of the retrieval problem. Design and implementation issues are outlined for MORE (Multimedia Object Retrieval Environment), a prototype system relying on the proposed model. The focus is on the main user interface functionalities, and actual interaction sessions are presented including schema creation, information loading, and information retrieval

  6. The Web system of visualization and analysis equipped with reproducibility

    International Nuclear Information System (INIS)

    Ueshima, Yutaka; Saito, Kanji; Takeda, Yasuhiro; Nakai, Youichi; Hayashi, Sachiko

    2005-01-01

    In the advanced photon experimental research, real-time visualization and steering system is thought as desirable method of data analysis. This approach is valid only in the fixed analysis at one time or in the easily reproducible experiment. But, in the research for an unknown problem like the advanced photon experimental research, it is necessary that the observation data can be analyzed many times because profitable analysis is difficult at the first time. Consequently, output data should be filed to refer and analyze at any time. To support the research, we need the followed automatic functions, transporting data files from data generator to data storage, analyzing data, tracking history of data handling, and so on. The supporting system will be integrated database system with several functional servers distributed on the network. (author)

  7. Inertia effects in rheometrical flow systems

    NARCIS (Netherlands)

    Waterman, H.A.

    1976-01-01

    The flow field of a linear viscoelastic material in the orthogonal rheometer, taking fluid inertia into account, has been studied theoretically and an exact solution is given. The flow field of a Newtonian liquid is included in this solution as a special case. The forces on the plates are readily

  8. Informing Regional Water-Energy-Food Nexus with System Analysis and Interactive Visualizations

    Science.gov (United States)

    Yang, Y. C. E.; Wi, S.

    2016-12-01

    Communicating scientific results to non-technical practitioners is challenging due to their differing interests, concerns and agendas. It is further complicated by the growing number of relevant factors that need to be considered, such as climate change and demographic dynamic. Visualization is an effective method for the scientific community to disseminate results, and it represents an opportunity for the future of water resources systems analysis (WRSA). This study demonstrates an intuitive way to communicate WRSA results to practitioners using interactive web-based visualization tools developed by the JavaScript library: Data-Driven Documents (D3) with a case study in Great Ruaha River of Tanzania. The decreasing trend of streamflow during the last decades in the region highlights the need of assessing the water usage competition between agricultural production, energy generation, and ecosystem service. Our team conduct the advance water resources systems analysis to inform policy that will affect the water-energy-food nexus. Modeling results are presented in the web-based visualization tools and allow non-technical practitioners to brush the graph directly (e. g. Figure 1). The WRSA suggests that no single measure can completely resolve the water competition. A combination of measures, each of which is acceptable from a social and economic perspective, and accepting that zero flows cannot be totally eliminated during dry years in the wetland, are likely to be the best way forward.

  9. Design flow factors for sewerage systems in small arid communities

    OpenAIRE

    Imam, Emad H.; Elnakar, Haitham Y.

    2014-01-01

    Reliable estimation of sewage flow rates is essential for the proper design of sewers, pumping stations, and treatment plants. The design of the various components of the sewerage system should be based on the most critical flow rates with a focus on extremely low and peak flow rates that would be sustained for a duration related to the acceptable limits of behavior of the components under consideration. The extreme flow conditions and to what extent they differ from the average values are cl...

  10. Investigation of the stability of melt flow in gating systems

    DEFF Research Database (Denmark)

    Tiedje, Niels Skat; Larsen, Per

    2011-01-01

    Melt flow in four different gating systems designed for production of brake discs was analysed experimentally and by numerical modelling. In the experiments moulds were fitted with glass fronts and melt flow was recorded on video. The video recordings were compared with modelling of melt flow...... in the gating systems. Particular emphasis was on analysing local pressure and formation of pressure waves in the gating system. It was possible to compare melt flow patterns in experiments directly to modelled flow patterns. Generally there was good agreement between flow patterns and filling times. However...... description of free liquid surfaces proved to be incorrect in the numerical model. Modelled pressure fields served to explain how specific parts of the gating systems cause instability and are a good tool to describe the quality of a gating system. The results shows clearly that sharp changes in the geometry...

  11. The visual system of diurnal raptors: updated review.

    Science.gov (United States)

    González-Martín-Moro, J; Hernández-Verdejo, J L; Clement-Corral, A

    2017-05-01

    Diurnal birds of prey (raptors) are considered the group of animals with highest visual acuity (VA). The purpose of this work is to review all the information recently published about the visual system of this group of animals. A bibliographic search was performed in PubMed. The algorithm used was (raptor OR falcon OR kestrel OR hawk OR eagle) AND (vision OR «visual acuity» OR eye OR macula OR retina OR fovea OR «nictitating membrane» OR «chromatic vision» OR ultraviolet). The search was restricted to the «Title» and «Abstract» fields, and to non-human species, without time restriction. The proposed algorithm located 97 articles. Birds of prey are endowed with the highest VA of the animal kingdom. However most of the works study one individual or a small group of individuals, and the methodology is heterogeneous. The most studied bird is the Peregrine falcon (Falco peregrinus), with an estimated VA of 140 cycles/degree. Some eagles are endowed with similar VA. The tubular shape of the eye, the large pupil, and a high density of photoreceptors make this extraordinary VA possible. In some species, histology and optic coherence tomography demonstrate the presence of 2foveas. The nasal fovea (deep fovea) has higher VA. Nevertheless, the exact function of each fovea is unknown. The vitreous contained in the deep fovea could behave as a third lens, adding some magnification to the optic system. Copyright © 2017 Sociedad Española de Oftalmología. Publicado por Elsevier España, S.L.U. All rights reserved.

  12. Activation of Visuomotor Systems during Visually Guided Movements: A Functional MRI Study

    Science.gov (United States)

    Ellermann, Jutta M.; Siegal, Joel D.; Strupp, John P.; Ebner, Timothy J.; Ugurbil, Kâmil

    1998-04-01

    The dorsal stream is a dominant visuomotor pathway that connects the striate and extrastriate cortices to posterior parietal areas. In turn, the posterior parietal areas send projections to the frontal primary motor and premotor areas. This cortical pathway is hypothesized to be involved in the transformation of a visual input into the appropriate motor output. In this study we used functional magnetic resonance imaging (fMRI) of the entire brain to determine the patterns of activation that occurred while subjects performed a visually guided motor task. In nine human subjects, fMRI data were acquired on a 4-T whole-body MR system equipped with a head gradient coil and a birdcage RF coil using aT*2-weighted EPI sequence. Functional activation was determined for three different tasks: (1) a visuomotor task consisting of moving a cursor on a screen with a joystick in relation to various targets, (2) a hand movement task consisting of moving the joystick without visual input, and (3) a eye movement task consisting of moving the eyes alone without visual input. Blood oxygenation level-dependent (BOLD) contrast-based activation maps of each subject were generated using period cross-correlation statistics. Subsequently, each subject's brain was normalized to Talairach coordinates, and the individual maps were compared on a pixel by pixel basis. Significantly activated pixels common to at least four out of six subjects were retained to construct the final functional image. The pattern of activation during visually guided movements was consistent with the flow of information from striate and extrastriate visual areas, to the posterior parietal complex, and then to frontal motor areas. The extensive activation of this network and the reproducibility among subjects is consistent with a role for the dorsal stream in transforming visual information into motor behavior. Also extensively activated were the medial and lateral cerebellar structures, implicating the cortico

  13. Shear Evaluation by Quantitative Flow Visualization Near the Casing Surface of a Centrifugal Blood Pump

    Science.gov (United States)

    Nishida, Masahiro; Yamane, Takashi; Tsukamoto, Yuki; Ito, Kazuyuki; Konishi, Yoshiaki; Masuzawa, Toru; Tsukiya, Tomonori; Endo, Seiko; Taenaka, Yoshiyuki

    To clarify the correlation between high-shear flow and hemolysis in blood pumps, detail shear velocity distribution was quantified by an experimental method with a model centrifugal blood pump that has a series data of hemolysis tests and computational fluid dynamic analyses. Particular attention was paid to the shear velocity near the casing surface in the volute where the high shear causes in circumferentially wide region that is considerable to cause high hemolysis. Three pump models were compared concern with the radial gap width between the impeller and casing (the radial volute width) also with the outlet position whereas the impeller geometry was identical. These casing geometries were as follows: model 1-the gap width is standard 3mm and the outlet locates to make a smooth geometrical connection with the volute, model 2-the gap width is small 0.5mm and the outlet locates to make the smooth geometrical connection with the volute, and model 3-the gap width is small 0.5mm and the outlet locates to hardly make the smooth geometrical connection with the volute but be similar radial position with that of model 1. Velocity was quantified with a particle tracking velocimetry that is one of the quantitative flow visualization techniques, and the shear velocity was calculated. Results showed that all large shear velocity existed within the layers of about 0.1mm from the casing surface and that those layers were hardly affected by a vane passage even if the gap width is 0.5mm. They also showed that the maximum shear velocity appeared on the casing surface, and the shear velocities of models 2 and 3 were almost twice as large as that of model 1. This finding is in full corresponding with the results of hemolysis tests which showed that the hemolysis levels of both models 2 and 3 were 1.5 times higher than that of model 1. These results suggest that detailed high-shear evaluation near the casing surface in the volute is one of the most important keys in estimating the

  14. Visual System Involvement in Patients with Newly Diagnosed Parkinson Disease.

    Science.gov (United States)

    Arrigo, Alessandro; Calamuneri, Alessandro; Milardi, Demetrio; Mormina, Enricomaria; Rania, Laura; Postorino, Elisa; Marino, Silvia; Di Lorenzo, Giuseppe; Anastasi, Giuseppe Pio; Ghilardi, Maria Felice; Aragona, Pasquale; Quartarone, Angelo; Gaeta, Michele

    2017-12-01

    Purpose To assess intracranial visual system changes of newly diagnosed Parkinson disease in drug-naïve patients. Materials and Methods Twenty patients with newly diagnosed Parkinson disease and 20 age-matched control subjects were recruited. Magnetic resonance (MR) imaging (T1-weighted and diffusion-weighted imaging) was performed with a 3-T MR imager. White matter changes were assessed by exploring a white matter diffusion profile by means of diffusion-tensor imaging-based parameters and constrained spherical deconvolution-based connectivity analysis and by means of white matter voxel-based morphometry (VBM). Alterations in occipital gray matter were investigated by means of gray matter VBM. Morphologic analysis of the optic chiasm was based on manual measurement of regions of interest. Statistical testing included analysis of variance, t tests, and permutation tests. Results In the patients with Parkinson disease, significant alterations were found in optic radiation connectivity distribution, with decreased lateral geniculate nucleus V2 density (F, -8.28; P Parkinson disease and that the entire intracranial visual system can be involved. © RSNA, 2017 Online supplemental material is available for this article.

  15. Rock Visualization System. Technical description (RVS v.3.5)

    Energy Technology Data Exchange (ETDEWEB)

    Curtis, P.; Elfstroem, M.; Markstroem, I. [FB Engineering, Goeteborg (Sweden)

    2004-03-01

    The Rock Visualization System (RVS) has been developed by SKB for use in visualizing geological and engineering data in 3D. The purpose of this report is to provide a technical description of RVS aimed at potential program users and interested parties as well as fulfilling the function of a more general RVS reference that can be cited when writing other technical reports. It is a description of RVS version 3.5. Updated versions of this report or addenda will be made available following further development of RVS and the release of subsequent versions of the program. The report covers the following main items: Technical description of the program with illustrations and examples; Limitations of the program and of functionality. For most RVS functions step-by-step tutorials are available describing how a particular function can be used to carryout a specific task. A complete set of updated tutorials is issued with each new version release of the RVS program. However, the tutorials do not cover all the possible uses of all the individual functions but rather give an overall view of their functionality. A detailed description of every RVS function and how it can be used is included in the RVS online Help system.

  16. Rock Visualization System. Technical description (RVS version 3.8)

    International Nuclear Information System (INIS)

    Curtis, P.; Elfstroem, M.; Markstroem, I.

    2007-06-01

    The Rock Visualization System (RVS) has been developed by SKB for use in visualizing geological and engineering data in 3D. The purpose of this report is to provide a technical description of RVS aimed at potential program users and interested parties as well as fulfilling the function of a more general RVS reference that can be cited when writing other technical reports. The report describes RVS version 4.0. Updated versions of this report or addenda will be made available following further development of RVS and the release of subsequent versions of the program. The report covers the following main items: Technical description of the program with illustrations and examples. Limitations of the program and of functionality. For most RVS functions step-by-step tutorials are available describing how a particular function can be used to carry out a specific task. A complete set of updated tutorials is issued with each new version release of the RVS program. However, the tutorials do not cover all the possible uses of all the individual functions but rather give an overall view of their functionality. A detailed description of every RVS function and how it can be used is included in the RVS online Help system

  17. Rock Visualization System. Technical description (RVS version 3.8)

    Energy Technology Data Exchange (ETDEWEB)

    Curtis, P.; Elfstroem, M.; Markstroem, I. [FB Engineering, Goeteborg (Sweden)

    2005-04-01

    The Rock Visualization System (RVS) has been developed by SKB for use in visualizing geological and engineering data in 3D. The purpose of this report is to provide a technical description of RVS aimed at potential program users and interested parties as well as fulfilling the function of a more general RVS reference that can be cited when writing other technical reports. The report describes RVS version 3.8. Updated versions of this report or addenda will be made available following further development of RVS and the release of subsequent versions of the program. The report covers the following main items: Technical description of the program with illustrations and examples. Limitations of the program and of functionality. For most RVS functions step-by-step tutorials are available describing how a particular function can be used to carryout a specific task. A complete set of updated tutorials is issued with each new version release of the RVS program. However, the tutorials do not cover all the possible uses of all the individual functions but rather give an overall view of their functionality. A detailed description of every RVS function and how it can be used is included in the RVS online Help system.

  18. Mutational Analysis of Drosophila Basigin Function in the Visual System

    Science.gov (United States)

    Munro, Michelle; Akkam, Yazan; Curtin, Kathryn D.

    2009-01-01

    Drosophila basigin is a cell-surface glycoprotein of the Ig superfamily and a member of a protein family that includes mammalian EMMPRIN/CD147/basigin, neuroplastin, and embigin. Our previous work on Drosophila basigin has shown that it is required for normal photoreceptor cell structure and normal neuron-glia interaction in the fly visual system. Specifically, the photoreceptor neurons of mosaic animals that are mutant in the eye for basigin show altered cell structure with nuclei, mitochondria and rER misplaced and variable axon diameter compared to wild-type. In addition, glia cells in the optic lamina that contact photoreceptor axons are misplaced and show altered structure. All these defects are rescued by expression of either transgenic fly basigin or transgenic mouse basigin in the photoreceptors demonstrating that mouse basigin can functionally replace fly basigin. To determine what regions of the basigin protein are required for each of these functions, we have created mutant basigin transgenes coding for proteins that are altered in conserved residues, introduced these into the fly genome, and tested them for their ability to rescue both photoreceptor cell structure defects and neuron-glia interaction defects of basigin. The results suggest that the highly conserved transmembrane domain and the extracellular domains are crucial for basigin function in the visual system while the short intracellular tail may not play a role in these functions. PMID:19782733

  19. Rock Visualization System. Technical description (RVS version 3.8)

    Energy Technology Data Exchange (ETDEWEB)

    Curtis, P.; Elfstroem, M.; Markstroem, I. [Golder Associates AB (Sweden)

    2007-06-15

    The Rock Visualization System (RVS) has been developed by SKB for use in visualizing geological and engineering data in 3D. The purpose of this report is to provide a technical description of RVS aimed at potential program users and interested parties as well as fulfilling the function of a more general RVS reference that can be cited when writing other technical reports. The report describes RVS version 4.0. Updated versions of this report or addenda will be made available following further development of RVS and the release of subsequent versions of the program. The report covers the following main items: Technical description of the program with illustrations and examples. Limitations of the program and of functionality. For most RVS functions step-by-step tutorials are available describing how a particular function can be used to carry out a specific task. A complete set of updated tutorials is issued with each new version release of the RVS program. However, the tutorials do not cover all the possible uses of all the individual functions but rather give an overall view of their functionality. A detailed description of every RVS function and how it can be used is included in the RVS online Help system.

  20. Rock Visualization System. Technical description (RVS v.3.5)

    International Nuclear Information System (INIS)

    Curtis, P.; Elfstroem, M.; Markstroem, I.

    2004-03-01

    The Rock Visualization System (RVS) has been developed by SKB for use in visualizing geological and engineering data in 3D. The purpose of this report is to provide a technical description of RVS aimed at potential program users and interested parties as well as fulfilling the function of a more general RVS reference that can be cited when writing other technical reports. It is a description of RVS version 3.5. Updated versions of this report or addenda will be made available following further development of RVS and the release of subsequent versions of the program. The report covers the following main items: Technical description of the program with illustrations and examples; Limitations of the program and of functionality. For most RVS functions step-by-step tutorials are available describing how a particular function can be used to carryout a specific task. A complete set of updated tutorials is issued with each new version release of the RVS program. However, the tutorials do not cover all the possible uses of all the individual functions but rather give an overall view of their functionality. A detailed description of every RVS function and how it can be used is included in the RVS online Help system

  1. Rock Visualization System. Technical description (RVS version 3.8)

    International Nuclear Information System (INIS)

    Curtis, P.; Elfstroem, M.; Markstroem, I.

    2005-04-01

    The Rock Visualization System (RVS) has been developed by SKB for use in visualizing geological and engineering data in 3D. The purpose of this report is to provide a technical description of RVS aimed at potential program users and interested parties as well as fulfilling the function of a more general RVS reference that can be cited when writing other technical reports. The report describes RVS version 3.8. Updated versions of this report or addenda will be made available following further development of RVS and the release of subsequent versions of the program. The report covers the following main items: Technical description of the program with illustrations and examples. Limitations of the program and of functionality. For most RVS functions step-by-step tutorials are available describing how a particular function can be used to carryout a specific task. A complete set of updated tutorials is issued with each new version release of the RVS program. However, the tutorials do not cover all the possible uses of all the individual functions but rather give an overall view of their functionality. A detailed description of every RVS function and how it can be used is included in the RVS online Help system

  2. Visualization of the structure of vortex breakdown in free swirling jet flow

    NARCIS (Netherlands)

    Vanierschot, M.; Perçin, M.; van Oudheusden, B.W.

    2016-01-01

    In this paper we investigate the three dimensional flow structures in a free annular swirling jet flow undergoing vortex breakdown. The flow field is analyzed by means of time-resolved Tomographic Particle Image Velocimetry measurements. Both time-averaged and instantaneous flow structures are

  3. Flow Forecasting in Drainage Systems with Extrapolated Radar Rainfall Data and Auto Calibration on Flow Observations

    DEFF Research Database (Denmark)

    Thorndahl, Søren Liedtke; Grum, M.; Rasmussen, Michael R.

    2011-01-01

    Forecasting of flows, overflow volumes, water levels, etc. in drainage systems can be applied in real time control of drainage systems in the future climate in order to fully utilize system capacity and thus save possible construction costs. An online system for forecasting flows and water levels......-calibrated on flow measurements in order to produce the best possible forecast for the drainage system at all times. The system shows great potential for the implementation of real time control in drainage systems and forecasting flows and water levels.......Forecasting of flows, overflow volumes, water levels, etc. in drainage systems can be applied in real time control of drainage systems in the future climate in order to fully utilize system capacity and thus save possible construction costs. An online system for forecasting flows and water levels...... in a small urban catchment has been developed. The forecast is based on application of radar rainfall data, which by a correlation based technique, is extrapolated with a lead time up to two hours. The runoff forecast in the drainage system is based on a fully distributed MOUSE model which is auto...

  4. Visualization of flows in a motored rotary combustion engine using holographic interferometry

    Science.gov (United States)

    Hicks, Y. R.; Schock, H. J.; Craig, J. E.; Umstatter, H. L.; Lee, D. Y.

    1986-01-01

    The use of holographic interferometry to view the small- and large-scale flow field structures in the combustion chamber of a motored Wankel engine assembly is described. In order that the flow patterns of interest could be observed, small quantities of helium were injected with the intake air. Variation of the air flow patterns with engine speed, helium flow rate, and rotor position are described. The air flow at two locations within the combustion chamber was examined using this technique.

  5. Wide-area, real-time monitoring and visualization system

    Science.gov (United States)

    Budhraja, Vikram S.; Dyer, James D.; Martinez Morales, Carlos A.

    2013-03-19

    A real-time performance monitoring system for monitoring an electric power grid. The electric power grid has a plurality of grid portions, each grid portion corresponding to one of a plurality of control areas. The real-time performance monitoring system includes a monitor computer for monitoring at least one of reliability metrics, generation metrics, transmission metrics, suppliers metrics, grid infrastructure security metrics, and markets metrics for the electric power grid. The data for metrics being monitored by the monitor computer are stored in a data base, and a visualization of the metrics is displayed on at least one display computer having a monitor. The at least one display computer in one said control area enables an operator to monitor the grid portion corresponding to a different said control area.

  6. Exciplex Fluorescence Systems for Two-Phase Visualization.

    Science.gov (United States)

    Kim, J.-U.; Golding, B.; Schock, H. J.; Nocera, D. G.; Keller, P.

    1996-03-01

    We report the development of diagnostic chemical systems for vapor-liquid visualization based on an exciplex (excited state complex) formed between dimethyl- or diethyl-substituted aniline and trimethyl-substituted naphthalenes. Quantum yields of individual monomers were measured and the exciplex emission spectra as well as fluorescence quenching mechanisms were analyzed. Quenching occurs by both static and dynamic mechanisms. Among the many formulations investigated in this study, a system consisting of 7% 1,4,6-trimethylnaphthalene (1,4,6-TMN) and 5% N,N-dimethylaniline (DMA) in 88% isooctane exciplex was found to be useful for the laser- induced fluorescence technique. The technique is expected to find application in observing mixture formation in diesel or spark ignition engines with spectrally well-separated fluorescence images obtained from the monomer and exciplex constituents dissolved in the gasoline fuel. *Supported by NSF MRSEC DMR-9400417 and the Center for Fundamental Materials Research.

  7. Fluorescent visualization of oxytocin in the hypothalamo-neurohypophysial system

    Directory of Open Access Journals (Sweden)

    Hirofumi eHashimoto

    2014-07-01

    Full Text Available Oxytocin (OXT is well known for its ability to the milk ejection reflex and uterine contraction. It is also involved in several other behaviors, such as anti-nociception, anxiety, feeding, social recognition and stress responses. OXT is synthesized in the magnocellular neurosecretory cells (MNCs in the hypothalamic paraventricular (PVN and the supraoptic nuclei (SON that terminate their axons in the posterior pituitary (PP. We generated transgenic rats that express the OXT and fluorescent protein fusion gene in order to visualize oxytocin in the hypothalamo-neurohypophysial system. In these transgenic rats, fluorescent proteins were observed in the MNCs and axon terminals in the PP. This transgenic rat is a new tool to study the physiological role of OXT in the hypothalamo-neurohypophysial system.

  8. The flow equation approach to many-particle systems

    CERN Document Server

    Kehrein, Stefan; Fujimori, A; Varma, C; Steiner, F

    2006-01-01

    This self-contained monograph addresses the flow equation approach to many-particle systems. The flow equation approach consists of a sequence of infinitesimal unitary transformations and is conceptually similar to renormalization and scaling methods. Flow equations provide a framework for analyzing Hamiltonian systems where these conventional many-body techniques fail. The text first discusses the general ideas and concepts of the flow equation method. In a second part these concepts are illustrated with various applications in condensed matter theory including strong-coupling problems and non-equilibrium systems. The monograph is accessible to readers familiar with graduate- level solid-state theory.

  9. Visual selection and maintenance of the cell lines with high plant regeneration ability and low ploidy level in Dianthus acicularis by monitoring with flow cytometry analysis.

    Science.gov (United States)

    Shiba, Tomonori; Mii, Masahiro

    2005-12-01

    Efficient plant regeneration system from cell suspension cultures was established in D. acicularis (2n=90) by monitoring ploidy level and visual selection of the cultures. The ploidy level of the cell cultures closely related to the shoot regeneration ability. The cell lines comprising original ploidy levels (2C+4C cells corresponding to DNA contents of G1 and G2 cells of diploid plant, respectively) showed high regeneration ability, whereas those containing the cells with 8C or higher DNA C-values showed low or no regeneration ability. The highly regenerable cell lines thus selected consisted of compact cell clumps with yellowish color and relatively moderate growth, suggesting that it is possible to select visually the highly regenerable cell lines with the original ploidy level. All the regenerated plantlets from the highly regenerable cell cultures exhibited normal phenotypes and no variations in ploidy level were observed by flow cytometry (FCM) analysis.

  10. Visual plasticity : Blindsight bridges anatomy and function in the visual system

    NARCIS (Netherlands)

    Tamietto, M.; Morrone, M.C.

    2016-01-01

    Some people who are blind due to damage to their primary visual cortex, V1, can discriminate stimuli presented within their blind visual field. This residual function has been recently linked to a pathway that bypasses V1, and connects the thalamic lateral geniculate nucleus directly with the

  11. Plasma flow in toroidal systems with a separatrix

    International Nuclear Information System (INIS)

    Gribkov, V.M.; Morozov, D.Kh.; Pogutse, O.P.

    1984-01-01

    A hydrodynamic plasma flow in toroidal systems is considered. Rlasma flow lines for various magnetic configurations are calculated. A particular attention is given to studying plasma flow in configurations with two magnetic a axes and a separatrix. The flow picture i the toroidal case is shown to qualita ity to penetrate through the separatrix - the latter becomes ''perforated''. Th he pictkre of these flows is calculated. The plasma diffusion coefficient with account for the separatrix is calculated and is shown not to turn into the infin nity in the toroidal case as well. The plasma flow is analytically considered in the model with distributed current as well as in the model with current conce entrated at the oroidal system axis. In the first case the existence of ''stagnant'' regions near the magnetic axis is established from which the plasma a does not flow out

  12. Position paper -- Tank ventilation system design air flow rates

    International Nuclear Information System (INIS)

    Goolsby, G.K.

    1995-01-01

    The purpose of this paper is to document a project position on required ventilation system design air flow rates for the waste storage tanks currently being designed by project W-236A, the Multi-Function Waste Tank Facility (MWTF). The Title 1 design primary tank heat removal system consists of two systems: a primary tank vapor space ventilation system; and an annulus ventilation system. At the conclusion of Title 1 design, air flow rates for the primary and annulus ventilation systems were 960 scfm and 4,400 scfm, respectively, per tank. These design flow rates were capable of removing 1,250,000 Btu/hr from each tank. However, recently completed and ongoing studies have resulted in a design change to reduce the extreme case heat load to 700,000 Btu/hr. This revision of the extreme case heat load, coupled with results of scale model evaporative testing performed by WHC Thermal Hydraulics, allow for a reduction of the design air flow rates for both primary and annulus ventilation systems. Based on the preceding discussion, ICF Kaiser Hanford Co. concludes that the design should incorporate the following design air flow rates: Primary ventilation system--500 scfm maximum and Annulus ventilation system--1,100 scfm maximum. In addition, the minimum air flow rates in the primary and annulus ventilation systems will be investigated during Title 2 design. The results of the Title 2 investigation will determine the range of available temperature control using variable air flows to both ventilation systems

  13. Radar Based Flow and Water Level Forecasting in Sewer Systems

    DEFF Research Database (Denmark)

    Thorndahl, Søren; Rasmussen, Michael R.; Grum, M.

    2009-01-01

    This paper describes the first radar based forecast of flow and/or water level in sewer systems in Denmark. The rainfall is successfully forecasted with a lead time of 1-2 hours, and flow/levels are forecasted an additional ½-1½ hours using models describing the behaviour of the sewer system. Bot...

  14. Experimental visualization of temperature fields and study of heat transfer enhancement in oscillatory flow in a grooved channel

    Energy Technology Data Exchange (ETDEWEB)

    Herman, C.; Kang, E. [Dept. of Mechanical Engineering, Johns Hopkins Univ., Baltimore, MD (United States)

    2001-01-01

    An experimental study was conducted of incompressible, moderate Reynolds number flow of air over heated rectangular blocks in a two-dimensional, horizontal channel. Holographic interferometry combined with high-speed cinematography was used to visualize the unsteady temperature fields in self- sustained oscillatory flow. Experiments were conducted in the laminar, transitional and turbulent flow regimes for Reynolds numbers in the range from Re = 520 to Re = 6600. Interferometric measurements were obtained in the thermally and fluiddynamically periodically fully developed flow region on the ninth heated block. Flow oscillations were first observed between Re = 1054 and Re = 1318. The period of oscillations, wavelength and propagation speed of the Tollmien-Schlichting waves in the main channel were measured at two characteristic flow velocities, Re = 1580 and Re = 2370. For these Reynolds numbers it was observed that two to three waves span one geometric periodicity length. At Re = 1580 the dominant oscillation frequency was found to be around 26 Hz and at Re = 2370 the frequency distribution formed a band around 125 Hz. Results regarding heat transfer and pressure drop are presented as a function of the Reynolds number, in terms of the block-average Nusselt number and the local Nusselt number as well as the friction factor. Measurements of the local Nusselt number together with visual observations indicate that the lateral mixing caused by flow instabilities is most pronounced along the upstream vertical wall of the heated block in the groove region, and it is accompanied by high heat transfer coefficients. At Reynolds numbers beyond the onset of oscillations the heat transfer in the grooved channel exceeds the performance of the reference geometry, the asymmetrically heated parallel plate channel. (orig.)

  15. Therapeutic Options for Controlling Fluids in the Visual System

    Science.gov (United States)

    Curry, Kristina M.; Wotring, Virginia E.

    2014-01-01

    Visual Impairment/Intracranial Pressure (VIIP) is a newly recognized risk at NASA. The VIIP project examines the effect of long-term exposure to microgravity on vision of crewmembers before and after they return to Earth. Diamox (acetazolamide) is a medication which is used to decrease intraocular pressure; however, it carries a 3% risk of kidney stones. Astronauts are at a higher risk of kidney stones during spaceflight and the use Diamox would only increase the risk; therefore alternative therapies were investigated. Histamine 2 (H2) antagonist acid blockers such as cimetidine, ranitidine, famotidine and nizatidine are typically used to relieve the symptoms of gastroesophageal reflux disease (GERD). H2 receptors have been found in the human visual system, which has led to research on the use of H2 antagonist blockers to control fluid production in the human eye. Another potential therapeutic strategy is targeted at aquaporins, which are water channels that help maintain fluid homeostasis. Aquaporin antagonists are also known to affect intracranial pressure which can in turn alter intraocular pressure. Studies on aquaporin antagonists suggest high potential for effective treatment. The primary objective of this investigation is to review existing research on alternate medications or therapy to significantly reduce intracranial and intraocular pressure. A literature review was conducted. Even though we do not have all the answers quite yet, a considerable amount of information was discovered, and findings were narrowed, which should allow for more conclusive answers to be found in the near future.

  16. Flow regimes in vertical gas-solid contact systems

    Energy Technology Data Exchange (ETDEWEB)

    Yerushalmi, J.; Cankurt, N. T.; Geldart, D.; Liss, B.

    1976-01-01

    The flow characteristics in fluidized beds, i.e., gas-solid systems, was studied to determine the flow regimes, the interaction of gas and solid in the various flow regimes and the dependence of this interaction and of transition between flow regimes on the properties of the gas and solid, on the gas and solid flow rates, and on the containing vessel. Fluidized beds with both coarse and fine particles are considered. Test results using high speed photography to view the operation of a 2-dimensional bed are discussed. (LCL)

  17. Batch management based monitoring system: design, implement, and visualization

    International Nuclear Information System (INIS)

    Kan Bowen; Shi Jingyan

    2012-01-01

    Torque, an efficient PBS (Portable Batch System)-based open source Resource Management system, was originally developed by Ames research center of NASA, which was designed to satisfy the computing requirements of heterogeneous network. With the development of distributed computing, Torque has been widely used in high performance computing cluster. However, because of the lack of a well designed monitoring system, it is difficult to monitor, record, and control, leading to low stability, reliability and manageability. To overcome those problems, this paper designs and implements an adaptive lightweight monitoring system for torque from five aspects. 1) A lightweight circulating filtration logging system is developed to obtain the real-time running status of torque; 2) One uniform interface was provided for administrators to define monitoring commands, which can query management resources of torque; 3) Storage strategy is designed to make monitoring information persistent; 4) One uniform interface is provided for users to customized alarms, which can submit exceptions and errors to users via emails and SMS in real time; 5) HTML5 technology is applied in the customizable visualization of the jobs' status in torque in real time. (authors)

  18. Information-flow-based Access Control for Virtualized Systems

    Directory of Open Access Journals (Sweden)

    Dmitriy Aleksandrovich Postoev

    2014-12-01

    Full Text Available The article is devoted to the method of information-flow-based access control, adopted for virtualized systems. General structure of access control system for virtual infrastructure is proposed.

  19. A GIS-Enabled, Michigan-Specific, Hierarchical Groundwater Modeling and Visualization System

    Science.gov (United States)

    Liu, Q.; Li, S.; Mandle, R.; Simard, A.; Fisher, B.; Brown, E.; Ross, S.

    2005-12-01

    , automatically extract data and attributes, and simulate unsteady groundwater flow and contaminant transport in response to water and land management decisions; * Visualize and map model simulations and predictions with data from the statewide groundwater database in a seamless interactive environment. IGW-M has the potential to significantly improve the productivity of Michigan groundwater management investigations. It changes the role of engineers and scientists in modeling and analyzing the statewide groundwater database from heavily physical to cognitive problem-solving and decision-making tasks. The seamless real-time integration, real-time visual interaction, and real-time processing capability allows a user to focus on critical management issues, conflicts, and constraints, to quickly and iteratively examine conceptual approximations, management and planning scenarios, and site characterization assumptions, to identify dominant processes, to evaluate data worth and sensitivity, and to guide further data-collection activities. We illustrate the power and effectiveness of the M-IGW modeling and visualization system with a real case study and a real-time, live demonstration.

  20. Physically-Based Interactive Flow Visualization Based on Schlieren and Interferometry Experimental Techniques

    KAUST Repository

    Brownlee, C.; Pegoraro, V.; Shankar, S.; McCormick, Patrick S.; Hansen, C. D.

    2011-01-01

    Understanding fluid flow is a difficult problem and of increasing importance as computational fluid dynamics (CFD) produces an abundance of simulation data. Experimental flow analysis has employed techniques such as shadowgraph, interferometry