Sample records for freedom fluid system

  1. Weld joint concepts for on-orbit repair of Space Station Freedom fluid system tube assemblies (United States)

    Jolly, Steven D.


    Because Space Station Freedom (SSF) is an independent satellite, not depending upon another spacecraft for power, attitude control, or thermal regulation, it has a variety of tubular, fluid-carrying assemblies on-board. The systems of interest in this analysis provide breathing air (oxygen and nitrogen), a working fluid (two-phase anhydrous ammonia) for thermal control, and a monopropellant (hydrazine) for station reboost. The tube assemblies run both internally and externally with respect to the habitats. They are found in up to 50 ft. continuous lengths constructed of mostly AISI 316L stainless steel tubing, but also including some Inconel 625 nickel-iron and Monel 400 nickel-copper alloy tubing. The outer diameters (OD) of the tubes range from 0.25-1.25 inches, and the wall thickness between 0.028-.095 inches. The system operational pressures range from 377 psi (for the thermal control system) to 3400 psi (for the high pressure oxygen and nitrogen supply lines in the ECLSS). SSF is designed for a fifteen to thirty year mission. It is likely that the tubular assemblies (TA's) will sustain damage or fail during this lifetime such that they require repair or replacement. The nature of the damage will be combinations of punctures, chips, scratches, and creases and may be cosmetic or actually leaking. The causes of these hypothetical problems are postulated to be: (1) faulty or fatigued fluid joints--both QD's and butt-welds; (2) micro-meteoroid impacts; (3) collison with another man-made object; and (4) over-pressure strain or burst (system origin). While the current NASA baseline may be to temporarily patch the lines by clamping metal c-sections over the defect, and then perform high pressure injection of a sealing compound, it is clear that permanent repair of the line(s) is necessary. This permanent repair could be to replace the entire TA in the segment, or perhaps the segment itself, both alternatives being extremely expensive and risky. The former would likely

  2. Microgravity fluid physics research in the Space Station Freedom era (United States)

    Carpenter, Bradley M.


    Microgravity fluid physics covers an exciting range of established and potential fields of scientific research. Areas in which the Microgravity Science and Applications Division of NASA's Office of Space Science and Applications is currently supporting research include: multiphase flow and phase change heat transfer, behavior of granular media and colloids; and interface dynamics, morphological stability, and contact line phenomena. As they contribute to our knowledge of fluid behavior, advances in these areas will enhance our understanding of materials processing on Earth and in space, and will contribute to technologies as diverse as chemical extraction, the prediction of soil behavior in earthquakes, and the production of oil reservoirs. NASA' s primary platform for research in microgravity fluid physics will soon be the Fluid Physics/Dynamics Facility on Space Station Freedom. This facility shares a rack for control and utilities with the Modular Combustion Facility, and has one rack for experiment-unique instruments. It is planned to change out the content of the experiment-unique rack at intervals on the order of one year. In order to obtain a maximum return on the operation of the facility during these intervals, the research community must carefully plan and coordinate an effort that brings the efforts of many investigators to bear on problems of particular importance. NASA is currently working with the community to identify research areas in which microgravity can make a unique and valuable contribution, and to build a balanced program of research around these areas or thrusts. Selections will soon be made from our first solicitation for research in fluid dynamics and transport phenomena. These solicitations will build the research community that will make Space Station Freedom a catalyst for scientific and technological discovery, and offer U.S. scientists in many disciplines a unique opportunity to participate in space science.

  3. Freedom of Information Act (FOIA) Tracking System (United States)

    Office of Personnel Management — Tracking system which allows for the input of the Freedom of Information Act (FOIA) request date, compiles the due date, information pertaining to the request, name...

  4. Process fluid cooling system

    International Nuclear Information System (INIS)

    Farquhar, N.G.; Schwab, J.A.


    A system of heat exchangers is disclosed for cooling process fluids. The system is particularly applicable to cooling steam generator blowdown fluid in a nuclear plant prior to chemical purification of the fluid in which it minimizes the potential of boiling of the plant cooling water which cools the blowdown fluid

  5. Strategy for the reduction of total integrated fluid logistics to the Space Station Freedom (United States)

    Gould, Marston J.; Shannon, David T., Jr.


    The use of an integrated environmental control and life support system (ECLSS) and secondary propulsion system (SRS) on the Space Station Freedom (SSF) has many potential advantages. Through the metabolism of food, the crew on-board the station will produce carbon dioxide as a waste gas and an excess of water in the form of urine and condensate. The processing of these waste fluids by the ECLSS could produce quantities of oxygen that would eliminate the need for cryogenic oxygen resupply and hydrogen, carbon dioxide, and/or methane that could be used with the addition of a resistojet system to provide a constant low thrust for station. This additional thrust would represent significant savings in required hydrazine resupply.

  6. Man-systems distributed system for Space Station Freedom (United States)

    Lewis, J. L.


    Viewgraphs on man-systems distributed system for Space Station Freedom are presented. Topics addressed include: description of man-systems (definition, requirements, scope, subsystems, and topologies); implementation (approach, tools); man-systems interfaces (system to element and system to system); prime/supporting development relationship; selected accomplishments; and technical challenges.

  7. Space Station Freedom power management and distribution system design (United States)

    Teren, Fred


    The design is described of the Space Station Freedom Power Management and Distribution (PMAD) System. In addition, the significant trade studies which were conducted are described, which led to the current PMAD system configuration.

  8. Sphere based fluid systems (United States)

    Elleman, Daniel D. (Inventor); Wang, Taylor G. (Inventor)


    Systems are described for using multiple closely-packed spheres. In one system for passing fluid, a multiplicity of spheres lie within a container, with all of the spheres having the same outside diameter and with the spheres being closely nested in one another to create multiple interstitial passages of a known size and configuration and smooth walls. The container has an inlet and outlet for passing fluid through the interstitial passages formed between the nested spheres. The small interstitial passages can be used to filter out material, especially biological material such as cells in a fluid, where the cells can be easily destroyed if passed across sharp edges. The outer surface of the spheres can contain a material that absorbs a constitutent in the flowing fluid, such as a particular contamination gas, or can contain a catalyst to chemically react the fluid passing therethrough, the use of multiple small spheres assuring a large area of contact of these surfaces of the spheres with the fluid. In a system for storing and releasing a fluid such as hydrogen as a fuel, the spheres can include a hollow shell containing the fluid to be stored, and located within a compressable container that can be compressed to break the shells and release the stored fluid.

  9. Reliability of fluid systems

    Directory of Open Access Journals (Sweden)

    Kopáček Jaroslav


    Full Text Available This paper focuses on the importance of detection reliability, especially in complex fluid systems for demanding production technology. The initial criterion for assessing the reliability is the failure of object (element, which is seen as a random variable and their data (values can be processed using by the mathematical methods of theory probability and statistics. They are defined the basic indicators of reliability and their applications in calculations of serial, parallel and backed-up systems. For illustration, there are calculation examples of indicators of reliability for various elements of the system and for the selected pneumatic circuit.

  10. Dynamic Systems with a Finite Degrees of Freedom Number

    Directory of Open Access Journals (Sweden)

    Ładziński Radosław


    Full Text Available Taking as a starting point the law of conservation of the total energy of the system, and introducing two basic state functions - the Lagrangian and the Rayleigh function, the general form of the equation of motion for any dynamic system with a finite number of degrees of freedom is derived. The theory is illustrated by considering the rotating - type electromechanical energy converter with six degrees of freedom being the model of all essentially important types of DC and AC machines, including rotating power amplifiers, induction - and synchronous type motors - all of them discussed from both, the steady-state and the transient point of view. In the next part of the paper there is described a simple electric circuit with its model characterized by the holonomic constraints of the velocity-type. Finally, there is presented the kinematics and dynamics of the interesting mechanical system - the gyroscope placed on the rotating Earth.

  11. Orbital Express fluid transfer demonstration system (United States)

    Rotenberger, Scott; SooHoo, David; Abraham, Gabriel


    Propellant resupply of orbiting spacecraft is no longer in the realm of high risk development. The recently concluded Orbital Express (OE) mission included a fluid transfer demonstration that operated the hardware and control logic in space, bringing the Technology Readiness Level to a solid TRL 7 (demonstration of a system prototype in an operational environment). Orbital Express (funded by the Defense Advanced Research Projects Agency, DARPA) was launched aboard an Atlas-V rocket on March 9th, 2007. The mission had the objective of demonstrating technologies needed for routine servicing of spacecraft, namely autonomous rendezvous and docking, propellant resupply, and orbital replacement unit transfer. The demonstration system used two spacecraft. A servicing vehicle (ASTRO) performed multiple dockings with the client (NextSat) spacecraft, and performed a variety of propellant transfers in addition to exchanges of a battery and computer. The fluid transfer and propulsion system onboard ASTRO, in addition to providing the six degree-of-freedom (6 DOF) thruster system for rendezvous and docking, demonstrated autonomous transfer of monopropellant hydrazine to or from the NextSat spacecraft 15 times while on orbit. The fluid transfer system aboard the NextSat vehicle was designed to simulate a variety of client systems, including both blowdown pressurization and pressure regulated propulsion systems. The fluid transfer demonstrations started with a low level of autonomy, where ground controllers were allowed to review the status of the demonstration at numerous points before authorizing the next steps to be performed. The final transfers were performed at a full autonomy level where the ground authorized the start of a transfer sequence and then monitored data as the transfer proceeded. The major steps of a fluid transfer included the following: mate of the coupling, leak check of the coupling, venting of the coupling, priming of the coupling, fluid transfer, gauging

  12. TROUBLE 3: A fault diagnostic expert system for Space Station Freedom's power system (United States)

    Manner, David B.


    Designing Space Station Freedom has given NASA many opportunities to develop expert systems that automate onboard operations of space based systems. One such development, TROUBLE 3, an expert system that was designed to automate the fault diagnostics of Space Station Freedom's electric power system is described. TROUBLE 3's design is complicated by the fact that Space Station Freedom's power system is evolving and changing. TROUBLE 3 has to be made flexible enough to handle changes with minimal changes to the program. Three types of expert systems were studied: rule-based, set-covering, and model-based. A set-covering approach was selected for TROUBLE 3 because if offered the needed flexibility that was missing from the other approaches. With this flexibility, TROUBLE 3 is not limited to Space Station Freedom applications, it can easily be adapted to handle any diagnostic system.

  13. Closed Loop Fluid Delivery System (United States)


    loop fluid delivery system (CLFDS) will integrate a vital signs monitor ( VSM ) and high speed infusion pump (Pump) to respond quickly to drops in...Interface (GUI) shows VSM data, allows the user to select from several injury types (head, uncontrolled hemorrhage, controlled hemorrhage, and three total...the bedrock for future Closed Loop Fluid System Pre-Market Approval application(s) to FDA. 6. Major Issues Clinical study testing revealed a

  14. Vibration Analysis and Parameter Design of Two Degree of Freedom System Using Modelica

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Yeongmin; Lee, Jongsoo [Yonsei Univ., Seoul (Korea, Republic of)


    Today, we are using computer simulations in various engineering disciplines to reduce the time and cost of product development. The scope of simulations is increasingly complex and diverse for different fields such as mechanical, electrical, thermal, and fluid. Thus, it is necessary to use integrated simulations. In order to overcome these problems, a language has been developed to effectively describe and implement simulations is Modelica. To model and simulate a system, physical models can be broadly divided into causal and acausal models. The most important feature of Modelica is acausal programming. In this study, we will introduce simple concepts and explain about the usage of Modelica. Furthermore, we will explain the vibration analysis of a two degree-of-freedom system and the design of appropriate parameters by using Modelica.

  15. Poisson structure of dynamical systems with three degrees of freedom (United States)

    Gümral, Hasan; Nutku, Yavuz


    It is shown that the Poisson structure of dynamical systems with three degrees of freedom can be defined in terms of an integrable one-form in three dimensions. Advantage is taken of this fact and the theory of foliations is used in discussing the geometrical structure underlying complete and partial integrability. Techniques for finding Poisson structures are presented and applied to various examples such as the Halphen system which has been studied as the two-monopole problem by Atiyah and Hitchin. It is shown that the Halphen system can be formulated in terms of a flat SL(2,R)-valued connection and belongs to a nontrivial Godbillon-Vey class. On the other hand, for the Euler top and a special case of three-species Lotka-Volterra equations which are contained in the Halphen system as limiting cases, this structure degenerates into the form of globally integrable bi-Hamiltonian structures. The globally integrable bi-Hamiltonian case is a linear and the SL(2,R) structure is a quadratic unfolding of an integrable one-form in 3+1 dimensions. It is shown that the existence of a vector field compatible with the flow is a powerful tool in the investigation of Poisson structure and some new techniques for incorporating arbitrary constants into the Poisson one-form are presented herein. This leads to some extensions, analogous to q extensions, of Poisson structure. The Kermack-McKendrick model and some of its generalizations describing the spread of epidemics, as well as the integrable cases of the Lorenz, Lotka-Volterra, May-Leonard, and Maxwell-Bloch systems admit globally integrable bi-Hamiltonian structure.

  16. The role of the National Launch System in support of Space Station Freedom (United States)

    Green, J. L.; Saucillo, R. J.; Cirillo, W. M.


    A study was performed to determine the most appropriate potential use of the National Launch System (NLS) for Space Station Freedom (SSF) logistics resupply and growth assembly needs. Objectives were to estimate earth-to-SSF cargo requirements, identify NLS sizing trades, and assess operational constraints of a shuttle and NLS transportation infrastructure. Detailed NLS and Shuttle flight manifests were developed to model varying levels of NLS support. NLS delivery of SSF propellant, and in some cases, cryoenic fluids, yield significant shuttle flight savings with minimum impact to the baseline SSF design. Additional cargo can be delivered by the NLS if SSF trash disposal techniques are employed to limit return cargo requirements. A common vehicle performance level can be used for both logistics resupply and growth hardware delivery.

  17. Fluid Information Systems

    DEFF Research Database (Denmark)

    Probst, Christian W.; Hansen, René Rydhof


    Networked communication systems and the data they make available have, over the last decades, made their way to the very core of both society and business. Not only do they support everyday life and day-to-day operations, in many cases they enable them in the first place, and often are among...

  18. Wellbottom fluid implosion treatment system (United States)

    Brieger, Emmet F.


    A system for inducing implosion shock forces on perforation traversing earth formations with fluid pressure where an implosion tool is selected relative to a shut in well pressure and a tubing pressure to have a large and small area piston relationship in a well tool so that at a predetermined tubing pressure the pistons move a sufficient distance to open an implosion valve which permits a sudden release of well fluid pressure into the tubing string and produces an implosion force on the perforations. A pressure gauge on the well tool records tubing pressure and well pressure as a function of time.

  19. Compressor bleed cooling fluid feed system (United States)

    Donahoo, Eric E; Ross, Christopher W


    A compressor bleed cooling fluid feed system for a turbine engine for directing cooling fluids from a compressor to a turbine airfoil cooling system to supply cooling fluids to one or more airfoils of a rotor assembly is disclosed. The compressor bleed cooling fluid feed system may enable cooling fluids to be exhausted from a compressor exhaust plenum through a downstream compressor bleed collection chamber and into the turbine airfoil cooling system. As such, the suction created in the compressor exhaust plenum mitigates boundary layer growth along the inner surface while providing flow of cooling fluids to the turbine airfoils.

  20. Some remarks on integrable Hamiltonian systems with two degrees of freedom

    International Nuclear Information System (INIS)

    Nguyen Tien Dung.


    In this note, based on examples, we consider some aspects of integrable systems with two degrees of freedom: local and global theory, orbit space, integrable surgery, generalized Delzant spaces, relations with ''pure'' symplectic geometry, etc. (author). 23 refs, 18 figs

  1. Life support and internal thermal control system design for the Space Station Freedom (United States)

    Humphries, R.; Mitchell, K.; Reuter, J.; Carrasquillo, R.; Beverly, B.


    A Review of the Space Station Freedom Environmental Control and Life Support System (ECLSS) as well as the Internal Thermal Control System (ITCS) design, including recent changes resulting from an activity to restructure the program, is provided. The development state of the original Space Station Freedom ECLSS through the restructured configuration is considered and the selection of regenerative subsystems for oxygen and water reclamation is addressed. A survey of the present ground development and verification program is given.

  2. Asymptotic numerical method for multi-degree-of-freedom nonlinear dynamic systems

    International Nuclear Information System (INIS)

    Mei Shuli; Du Chengjin; Zhang Senwen


    Homotopy perturbation method (HPM) proposed by Ji-Huan He is very effective and convenient for single-degree-of-freedom systems. In this paper a coupling technique of He's method and precise integration method (PIM) is suggested to solve multi-degree-of-freedom nonlinear dynamic systems. The new technique keeps the merits of the two methods. Some examples are given to illustrate its effectiveness and convenience. Furthermore the obtained solution is of high accuracy

  3. Space Station Freedom power - A reliability, availability, and maintainability assessment of the proposed Space Station Freedom electric power system (United States)

    Turnquist, S. R.; Twombly, M.; Hoffman, D.


    A preliminary reliability, availability, and maintainability (RAM) analysis of the proposed Space Station Freedom electric power system (EPS) was performed using the unit reliability, availability, and maintainability (UNIRAM) analysis methodology. Orbital replacement units (ORUs) having the most significant impact on EPS availability measures were identified. Also, the sensitivity of the EPS to variations in ORU RAM data was evaluated for each ORU. Estimates were made of average EPS power output levels and availability of power to the core area of the space station. The results of assessments of the availability of EPS power and power to load distribution points in the space stations are given. Some highlights of continuing studies being performed to understand EPS availability considerations are presented.

  4. Semiotic Freedom

    DEFF Research Database (Denmark)

    Bruni, Luis Emilio


    ), but stress also their necessity in the study of any given biological and cognitive system. I draw a distinction between horizontal and vertical emergence in order to arrive at a notion of ‘second order emergence' that affords us a more viable definition of semiotic freedom. I will then attempt to show......-down approach i.e., by starting from the highest levels of semiotic freedom and cognitive processes, and exploring how those processes disaggregate into lesser degrees of freedom. I thus hope to bridge the gap between those levels from above....

  5. Parametric Modeling for Fluid Systems (United States)

    Pizarro, Yaritzmar Rosario; Martinez, Jonathan


    Fluid Systems involves different projects that require parametric modeling, which is a model that maintains consistent relationships between elements as is manipulated. One of these projects is the Neo Liquid Propellant Testbed, which is part of Rocket U. As part of Rocket U (Rocket University), engineers at NASA's Kennedy Space Center in Florida have the opportunity to develop critical flight skills as they design, build and launch high-powered rockets. To build the Neo testbed; hardware from the Space Shuttle Program was repurposed. Modeling for Neo, included: fittings, valves, frames and tubing, between others. These models help in the review process, to make sure regulations are being followed. Another fluid systems project that required modeling is Plant Habitat's TCUI test project. Plant Habitat is a plan to develop a large growth chamber to learn the effects of long-duration microgravity exposure to plants in space. Work for this project included the design and modeling of a duct vent for flow test. Parametric Modeling for these projects was done using Creo Parametric 2.0.

  6. Dynamics of a mechanical system with multiple degrees of freedom out of thermal equilibrium. (United States)

    Feigel, A


    Out of thermal equilibrium, an environment imposes effective mechanical forces on nanofabricated devices as well as on microscopic chemical or biological systems. Here we address the question of how to calculate these forces together with the response of the system from first principles. We show that an ideal gaslike environment, even near thermal equilibrium, can enforce a specific steady state on the system by creating effective potentials in otherwise homogeneous space. An example of stable and unstable rectifications of thermal fluctuations is presented using a modified Feynman-Smoluchowski ratchet with two degrees of freedom. Moreover, the stability of a steady configuration depends on its chiral symmetry. The transition rate probabilities and the corresponding kinetic equations are derived for a complex mechanical system with arbitrary degrees of freedom. This work, therefore, extends the applicability of mechanical systems as a toy model playground of statistical physics for active and living matter with multiple degrees of freedom.

  7. Leak detection of the Space Station Freedom U.S. Lab vacuum system using reverse flow leak detection methodology (United States)

    Moore, Jeffrey D.; Shepherd, James E.; Masden, Darrell E.


    A vacuum system leak detection technique (reverse flow leak detection) under development for use aboard Space Station Freedom is presented. The technique will be applied to the Vacuum System (VS) and Waste Gas Management Subsystem (WGMS) of the U.S. Lab Module. These two systems contain over 45.7 m of distributed vacuum tubing located in remote utility runs. Fluid flow calculations which utilize known system geometry and measured steady state pressure measurements from the VS and WGMS can be used to identify leak sites within +/- 38 cm. Exact leak position can then be pinpointed by conventional tracer gas leak detection in the identified region. Tests have been performed using a simple, unrestricted 12.8 m length of vacuum tubing with a calibrated air leak attached.

  8. Introduction to thermo-fluids systems design

    CERN Document Server

    Garcia McDonald, André


    A fully comprehensive guide to thermal systems design covering fluid dynamics, thermodynamics, heat transfer and thermodynamic power cycles Bridging the gap between the fundamental concepts of fluid mechanics, heat transfer and thermodynamics, and the practical design of thermo-fluids components and systems, this textbook focuses on the design of internal fluid flow systems, coiled heat exchangers and performance analysis of power plant systems. The topics are arranged so that each builds upon the previous chapter to convey to the reader that topics are not stand-alone i

  9. Vibration isolation systems, considered as systems with single degree of freedom

    Directory of Open Access Journals (Sweden)

    Zebilila Mohammed


    Full Text Available The research considers and analyzes vibration isolation systems, whose design schemes are single degree of freedom systems, including nonlinear elements - displacement limiter and viscous damper. Presented are calculation formulas in closed form for linear systems in operational modes (for harmonic and impulse loads, algorithms and examples of calculation of linear and nonlinear systems in operational and transient modes. The calculation method and the above dependences are written using the transfer (TF and impulse response functions (IRF of linear dynamical systems and dependencies that determine the relationship between these functions. The effectiveness of 2 options of vibration isolation systems in transient modes is analyzed. There is significant reduction of load from the equipment to the supporting structures in the starting-stopping modes by the use of displacement limiter.

  10. Capacitive system detects and locates fluid leaks (United States)


    Electronic monitoring system automatically detects and locates minute leaks in seams of large fluid storage tanks and pipelines covered with thermal insulation. The system uses a capacitive tape-sensing element that is adhesively bonded over seams where fluid leaks are likely to occur.

  11. Evaluating the operations capability of Freedom's Data Management System (United States)

    Sowizral, Henry A.


    Three areas of Data Management System (DMS) performance are examined: raw processor speed, the subjective speed of the Lynx OS X-Window system, and the operational capacity of the Runtime Object Database (RODB). It is concluded that the proposed processor will operate at its specified rate of speed and that the X-Window system operates within users' subjective needs. It is also concluded that the RODB cannot provide the required level of service, even with a two-order of magnitude (100 fold) improvement in speed.

  12. Main rotor six degree-of-freedom isolation system analysis (United States)

    Eastman, L. B.


    The design requirements of the system have been defined and an isolator concept satisfies these requirements identified. Primary design objectives for the isolation system are 90% attenuation of all NP main rotor shaft loads at a weight penalty less than or equal to 1% of design gross weight. The configuration is sized for a UH-60A BLACK HAWK helicopter and its performance, risk, and system integration were evaluated through a series of parametric studies. Preliminary design was carried forward to insure that the design is practical and that the details of the integration of the isolator into the helicopter system are considered. Alternate ground and flight test demonstration programs necessary to verify the proposed isolator design are defined.

  13. Deformed GOE for systems with a few degrees of freedom in the chaotic regime

    International Nuclear Information System (INIS)

    Hussein, M.S.; Pato, M.P.


    New distribution laws for the energy level spacings and the eigenvector amplitudes, appropriate for systems with a few degrees of freedom in the chaotic regime, are derived by conveniently deforming the GOE. The cases of 2X2 and 3X3 matrices are fully worked out. Suggestions concerning the general case of matrices with large dimensions are made. (author)

  14. Fluid systems for RICH detectors

    CERN Document Server

    Ullaland, O


    The optical properties of the radiator media are of prime importance in Ring Imaging Cherenkov detectors. The main requirements for the radiator fluid are a stable refractive index and a photon absorption as low as possible. We will in this note cover some of the cleaning procedures which are required together with distillation and similar separation procedures. Thin film membranes have been introduced during the last decade. They have proven particularly interesting in separating air from some Cherenkov fluids. We will also discuss the use of molecular sieves.

  15. Humanoid monocular stereo measuring system with two degrees of freedom using bionic optical imaging system (United States)

    Du, Jia-Wei; Wang, Xuan-Yin; Zhu, Shi-Qiang


    Based on the process by which the spatial depth clue is obtained by a single eye, a monocular stereo vision to measure the depth information of spatial objects was proposed in this paper and a humanoid monocular stereo measuring system with two degrees of freedom was demonstrated. The proposed system can effectively obtain the three-dimensional (3-D) structure of spatial objects of different distances without changing the position of the system and has the advantages of being exquisite, smart, and flexible. The bionic optical imaging system we proposed in a previous paper, named ZJU SY-I, was employed and its vision characteristic was just like the resolution decay of the eye's vision from center to periphery. We simplified the eye's rotation in the eye socket and the coordinated rotation of other organs of the body into two rotations in the orthogonal direction and employed a rotating platform with two rotation degrees of freedom to drive ZJU SY-I. The structure of the proposed system was described in detail. The depth of a single feature point on the spatial object was deduced, as well as its spatial coordination. With the focal length adjustment of ZJU SY-I and the rotation control of the rotation platform, the spatial coordinates of all feature points on the spatial object could be obtained and then the 3-D structure of the spatial object could be reconstructed. The 3-D structure measurement experiments of two spatial objects with different distances and sizes were conducted. Some main factors affecting the measurement accuracy of the proposed system were analyzed and discussed.

  16. Electromagnetic variable degrees of freedom actuator systems and methods (United States)

    Montesanti, Richard C [Pleasanton, CA; Trumper, David L [Plaistow, NH; Kirtley, Jr., James L.


    The present invention provides a variable reluctance actuator system and method that can be adapted for simultaneous rotation and translation of a moving element by applying a normal-direction magnetic flux on the moving element. In a beneficial example arrangement, the moving element includes a swing arm that carries a cutting tool at a set radius from an axis of rotation so as to produce a rotary fast tool servo that provides a tool motion in a direction substantially parallel to the surface-normal of a workpiece at the point of contact between the cutting tool and workpiece. An actuator rotates a swing arm such that a cutting tool moves toward and away from a mounted rotating workpiece in a controlled manner in order to machine the workpiece. Position sensors provide rotation and displacement information for a swing arm to a control system. A control system commands and coordinates motion of the fast tool servo with the motion of a spindle, rotating table, cross-feed slide, and in feed slide of a precision lathe.

  17. Stationary response of multi-degree-of-freedom vibro-impact systems to Poisson white noises

    International Nuclear Information System (INIS)

    Wu, Y.; Zhu, W.Q.


    The stationary response of multi-degree-of-freedom (MDOF) vibro-impact (VI) systems to random pulse trains is studied. The system is formulated as a stochastically excited and dissipated Hamiltonian system. The constraints are modeled as non-linear springs according to the Hertz contact law. The random pulse trains are modeled as Poisson white noises. The approximate stationary probability density function (PDF) for the response of MDOF dissipated Hamiltonian systems to Poisson white noises is obtained by solving the fourth-order generalized Fokker-Planck-Kolmogorov (FPK) equation using perturbation approach. As examples, two-degree-of-freedom (2DOF) VI systems under external and parametric Poisson white noise excitations, respectively, are investigated. The validity of the proposed approach is confirmed by using the results obtained from Monte Carlo simulation. It is shown that the non-Gaussian behaviour depends on the product of the mean arrival rate of the impulses and the relaxation time of the oscillator

  18. Autonomous power expert fault diagnostic system for Space Station Freedom electrical power system testbed (United States)

    Truong, Long V.; Walters, Jerry L.; Roth, Mary Ellen; Quinn, Todd M.; Krawczonek, Walter M.


    The goal of the Autonomous Power System (APS) program is to develop and apply intelligent problem solving and control to the Space Station Freedom Electrical Power System (SSF/EPS) testbed being developed and demonstrated at NASA Lewis Research Center. The objectives of the program are to establish artificial intelligence technology paths, to craft knowledge-based tools with advanced human-operator interfaces for power systems, and to interface and integrate knowledge-based systems with conventional controllers. The Autonomous Power EXpert (APEX) portion of the APS program will integrate a knowledge-based fault diagnostic system and a power resource planner-scheduler. Then APEX will interface on-line with the SSF/EPS testbed and its Power Management Controller (PMC). The key tasks include establishing knowledge bases for system diagnostics, fault detection and isolation analysis, on-line information accessing through PMC, enhanced data management, and multiple-level, object-oriented operator displays. The first prototype of the diagnostic expert system for fault detection and isolation has been developed. The knowledge bases and the rule-based model that were developed for the Power Distribution Control Unit subsystem of the SSF/EPS testbed are described. A corresponding troubleshooting technique is also described.

  19. Technology for Space Station Evolution. Volume 3: EVA/Manned Systems/Fluid Management System (United States)


    NASA's Office of Aeronautics and Space Technology (OAST) conducted a workshop on technology for space station evolution 16-19 Jan. 1990 in Dallas, Texas. The purpose of this workshop was to collect and clarify Space Station Freedom technology requirements for evolution and to describe technologies that can potentially fill those requirements. These proceedings are organized into an Executive Summary and Overview and five volumes containing the Technology Discipline Presentations. Volume 3 consists of the technology discipline sections for Extravehicular Activity/Manned Systems and the Fluid Management System. For each technology discipline, there is a Level 3 subsystem description, along with the papers.

  20. Hybrid Strategies for Link Adaptation Exploiting Several Degrees of Freedom in OFDM Based Broadband Wireless Systems

    DEFF Research Database (Denmark)

    Das, Suvra S.; Rahman, Muhammad Imadur; Wang, Yuanye


    In orthogonal frequency division multiplexing (OFDM) systems, there are several degrees of freedom in time and frequency domain, such as, sub-band size, forward error control coding (FEC) rate, modulation order, power level, modulation adaptation interval, coding rate adaptation interval and powe...... of the link parameters based on the channel conditions would lead to highly complex systems with high overhead. Hybrid strategies to vary the adaptation rates to tradeoff achievable efficiency and complexity are presented in this work.......In orthogonal frequency division multiplexing (OFDM) systems, there are several degrees of freedom in time and frequency domain, such as, sub-band size, forward error control coding (FEC) rate, modulation order, power level, modulation adaptation interval, coding rate adaptation interval and power...

  1. Maglev six degree-of-freedom fine position stage control system

    Energy Technology Data Exchange (ETDEWEB)

    Wronosky, J.B.; Smith, T.G.; Darnold, J.R.; Jordan, J.D.


    A wafer positioning system was recently developed by Sandia National Laboratories for an Extreme Ultraviolet Lithography (EUVL). The system, which utilizes a magnetically levitated fine stage to provide ultra-precise positioning in all six degrees of freedom, incorporates technological improvements resulting from four years of prototype development experience. System enhancements, implemented on a second generation design for a National Center for Advanced Information Component Manufacturing (NCAICM) Structural Control Testbed, define the present level of research. This paper describes the design, implementation, and functional capability of the systems. Specifics regarding control system electronics, including software and control algorithm structure, as well as performance design goals and test results are presented.

  2. The effects of nonlinear loading upon the Space Station Freedom 20 kHz power system (United States)

    Leskovich, R. Thomas; Hansen, Irving G.


    The Space Station Freedom power distribution system, which consists of dual redundant 20-kHz, 440-V RMS, single-phase power systems, is discussed. The effect of a typical space station nonlinear load on the measurement of RMS current and voltage at various points in the space station power system has been investigated using the Electromagnetic Transients Program (EMTP). The load current distortion at the user interface, its effect on the distribution system, and its relationship to power factor have been studied. Modeling results are compared to test data. The differences under nonlinear loading are evaluated and presented as a measure of distribution voltage distortion and current measurement accuracy.

  3. Selection of fluids for tritium pumping systems

    International Nuclear Information System (INIS)

    Chastagner, P.


    The degradation characteristics of three types of vacuum pump fluids, polyphenyl ethers, perfluoropolyethers and hydrocarbon oils were reviewed. Fluid selection proved to be a critical factor in the long-term performance of tritium pumping systems and subsequent tritium recovery operations. Thermal degradation and tritium radiolysis of pump fluids produce contaminants which can damage equipment and interfere with tritium recovery operations. General characteristics of these fluids are as follows: polyphenyl ether has outstanding radiation resistance, is very stable under normal diffusion pump conditions, but breaks down in the presence of oxygen at anticipated operating temperatures. Perfluoropolyether fluids are very stable and do not react chemically with most gases. Thermal and mechanical degradation products are inert, but the radiolysis products are very corrosive. Most of the degradation products of hydrogen oils are volatile and the principal radiolysis product is methane. Our studies show that polyphenyl ethers and hydrocarbon oils are the preferred fluids for use in tritium pumping systems. No corrosive materials are formed and most of the degradation products can be removed with suitable filter systems

  4. Interference alignment for degrees of freedom improvement in 3-relay half-duplex systems

    KAUST Repository

    Park, Seongho


    In a half-duplex relaying, the capacity pre-log factor is a major drawback in spectral efficiency. This paper proposes a linear precoding scheme and an alternate relaying protocol in a dual-hop half-duplex system where three relays help the communication between the source and the destination. In our proposed scheme, we consider a phase incoherent method in relays in which the source alternately transmits message signals to the different relays. In addition, we propose a linear interference alignment scheme which can eliminate the inter-relay interference resulted from the phase incoherence of relaying. Based on our analysis of degrees of freedom and our simulation results, we show that our proposed scheme achieves additional degrees of freedom compared to the conventional half-duplex relaying. © 2011 IEEE.


    Directory of Open Access Journals (Sweden)



    Full Text Available Generalized differential transform method (GDTM is a powerful method to solve the fractional differential equations. In this paper, a new fractional model for systems with single degree of freedom (SDOF is presented, by using the GDTM. The advantage of this method compared with some other numerical methods has been shown. The analysis of new approximations, damping and acceleration of systems are also described. Finally, by reducing damping and analysis of the errors, in one of the fractional cases, we have shown that in addition to having a suitable solution for the displacement close to the exact one, the system enjoys acceleration once crossing the equilibrium point.

  6. Reliable Fluid Power Pitch Systems

    DEFF Research Database (Denmark)

    Liniger, Jesper; Pedersen, Henrik Clemmensen; Soltani, Mohsen


    The key objectives of wind turbine manufactures and buyers are to reduce the Total Cost of Ownership and Total Cost of Energy. Among others, low downtime of a wind turbine is important to increase the amount of energy produced during its lifetime. Historical data indicate that pitch systems...... accounts for a substantial part of the downtime of wind turbines. With a focus on fluid power pitch systems; this paper presents an overview of methods relevant to assessing and increasing the reliability and availability of such systems. Four major areas are identified and covered; failure analysis...

  7. Fluid measurement and characterisation system


    Baldi Coll, Antonio; Sacristán Riquelme, Jorge; García-Cantón, Jesús


    [EN] The invention relates to a system for measuring parameters of a liquid being stirred. The invention consists of a system comprising a magnetic stirrer and a read unit that communicates wirelessly with wireless sensors positioned next to the magnetic stirring rod. In this way, it is possible to stir the liquid and monitor the parameters of the liquid with a single device and without using electrical wiring in order to access the interior of the container housing the liquid to be ...

  8. Stochastic Responses of Multi-Degree-of-Freedom Uncertain Hysteretic Systems

    Directory of Open Access Journals (Sweden)

    Yimin Zhang


    Full Text Available On the basis of the Bouc-Wen hysteretic model, the effective numerical method for the response of nonlinear multi-degree-of-freedom (MDOF stochastic hysteretic systems is presented using second moment method. Using this method, the mean values, variances and covariances are computed. The Monte Carlo simulation is applied to validate the method. The results obtained by the two methods are contrasted, and the solutions of the method in this paper agreed very well with the Monte Carlo simulation. It has solved the random response of nonlinear stochastic vibration systems which is caused by the stochastic hysteretic loop itself.

  9. Fluid structure interaction in piping systems

    Energy Technology Data Exchange (ETDEWEB)

    Svingen, Bjoernar


    The Dr. ing. thesis relates to an analysis of fluid structure interaction in piping systems in the frequency domain. The governing equations are the water hammer equations for the liquid, and the beam-equations for the structure. The fluid and structural equations are coupled through axial stresses and fluid continuity relations controlled by the contraction factor (Poisson coupling), and continuity and force relations at the boundaries (junction coupling). A computer program has been developed using the finite element method as a discretization technique both for the fluid and for the structure. This is made for permitting analyses of large systems including branches and loops, as well as including hydraulic piping components, and experiments are executed. Excitations are made in a frequency range from zero Hz and up to at least one thousand Hz. Frequency dependent friction is modelled as stiffness proportional Rayleigh damping both for the fluid and for the structure. With respect to the water hammer equations, stiffness proportional damping is seen as an artificial (bulk) viscosity term. A physical interpretation of this term in relation to transient/oscillating hydraulic pipe-friction is given. 77 refs., 72 figs., 4 tabs.

  10. Intelligent monitoring and diagnosis systems for the Space Station Freedom ECLSS (United States)

    Dewberry, Brandon S.; Carnes, James R.


    Specific activities in NASA's environmental control and life support system (ECLSS) advanced automation project that is designed to minimize the crew and ground manpower needed for operations are discussed. Various analyses and the development of intelligent software for the initial and evolutionary Space Station Freedom (SSF) ECLSS are described. The following are also discussed: (1) intelligent monitoring and diagnostics applications under development for the ECLSS domain; (2) integration into the MSFC ECLSS hardware testbed; and (3) an evolutionary path from the baseline ECLSS automation to the more advanced ECLSS automation processes.

  11. Fluid/structure interaction in piping systems

    International Nuclear Information System (INIS)

    Kellner, A.; Schoenfelder, C.


    The global movement of piping systems caused by pressure pulses as well as the associated loads on bends, nozzles and piping support structures are usually computed by using the pressures given by a hydrodynamic calculation as driving functions in a consecutive dynamic structure analysis without taking into account the secondary pressure pulses induced by the piping movement in the fluid. It is shown how including this feed-back of the structure dynamics on the fluid can lead to a drastic reduction of the computed loads

  12. Spectral coupling issues in a two-degree-of-freedom system with clearance non-linearities (United States)

    Padmanabhan, C.; Singh, R.


    In an earlier study [14], the frequency response characteristics of a multi-degree-of-freedom system with clearance non-linearities were presented. The current study is an extension of this prior work and deals specifically with the issue of dynamic interactions between resonances. The harmonic balance method, digital solutions and analog computer simulation are used to investigate a two-degree-of-freedom system under a mean load, when subjected to sinusoidal excitations. The existence of harmonic, periodic and chaotic solutions is demonstrated using digital simulation. The method of harmonic balance is employed to construct approximate solutions at the excitation frequency which are then used to classify weak, moderate and strong non-linear spectral interactions. The effects of parameters such as damping ratio, mean load, alternating load and frequency spacing between the resonances have been quantified. The applicability of the methodology is demonstrated through the following practical examples: (i) neutral gear rattle in an automotive transmission system; and (ii) steady state characteristics of a spur gear pair with backlash. In the second case, measured dynamic transmission error data at the gear mesh frequency are used to investigate spectral interactions. Limitations associated with solution methods and interaction classification schemes are also discussed.

  13. External Periodic Force Control of a Single-Degree-of-Freedom Vibroimpact System

    Directory of Open Access Journals (Sweden)

    Jingyue Wang


    Full Text Available A single-degree-of-freedom mechanical model of vibro-impact system is established. Bifurcation and chaos in the system are revealed with the time history diagram, phase trajectory map, and Poincaré map. According to the bifurcation and chaos of the actual vibro-impact system, the paper puts forward external periodic force control strategy. The method of controlling chaos by external periodic force feedback controller is developed to guide chaotic motions towards regular motions. The stability of the control system is also analyzed especially by theory. By selecting appropriate feedback coefficients, the unstable periodic orbits of the original chaotic orbit can be stabilized to the stable periodic orbits. The effectiveness of this control method is verified by numerical simulation.

  14. Development of a dexterous manipulator system with redundant degrees of freedom

    International Nuclear Information System (INIS)

    Senoh, M.; Suzuki, M.; Tsuchita, K.; Kamimura, H.; Fujii, M.; Otsu, M.


    To keep plant availability as high as possible, more flexible and higher performance robots are desirable. At the same time, lower radiation exposures to operating personnel can be achieved by employing more sophisticated robotic systems. A new maintenance system has been proposed to realize consecutive disassembling and inspecting tasks by a robotic approach. The maintenance system includes three subsystems: a subsystem for the minor disassembling operations in the field; a transportation subsystem, which carries disassembled machines or components from the place where they were installed to a maintenance shop; and a subsystem for consecutive disassembling and grooming operations. Of these three subsystems, the maintenance robot for the first is the most challenging, and much development work is needed in the area of maneuverability in narrow spaces and obstacle avoidance ability. A master/slave-type manipulator with redundant degrees of freedom, mounted on a vehicle that travels along a spatially located railway, has been developed

  15. Balancing economic freedom against social policy principles: EC competition law and national health systems. (United States)

    Mossialos, Elias; Lear, Julia


    EU Health policy exemplifies the philosophical tension between EC economic freedoms and social policy. EC competition law, like other internal market rules, could restrict national health policy options despite the subsidiarity principle. In particular, European health system reforms that incorporate elements of market competition may trigger the application of competition rules if non-economic gains in consumer welfare are not adequately accounted for. This article defines the policy and legal parameters of the debate between competition law and health policy. Using a sample of cases it analyses how the ECJ, national courts, and National Competition Authorities have applied competition laws to the health services sector in different circumstances and in different ways. It concludes by considering the implications of the convergence of recent trends in competition law enforcement and health system market reforms. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  16. Monodromy of a two degrees of freedom Liouville integrable system with many focus-focus singular points

    International Nuclear Information System (INIS)

    Cushman, Richard; Zhilinskii, Boris


    This letter deals with the global monodromy of singular Lagrangian toral fibrations defined by two degrees of freedom Liouville integrable systems with only focus-focus singular points. We show that any global monodromy matrix in Sl(2,Ζ ) is realizable by such a system. (author). Letter-to-the-editor

  17. An automated rendezvous and capture system design concept for the cargo transfer vehicle and Space Station Freedom (United States)

    Fuchs, Ron; Marsh, Steven


    A rendezvous sensor system concept was developed for the cargo transfer vehicle (CTV) to autonomously rendezvous with and be captured by Space Station Freedom (SSF). The development of requirements, the design of a unique Lockheed developed sensor concept to meet these requirements, and the system design to place this sensor on the CTV and rendezvous with the SSF are described .

  18. Development and calibration of an accurate 6-degree-of-freedom measurement system with total station

    International Nuclear Information System (INIS)

    Gao, Yang; Lin, Jiarui; Yang, Linghui; Zhu, Jigui


    To meet the demand of high-accuracy, long-range and portable use in large-scale metrology for pose measurement, this paper develops a 6-degree-of-freedom (6-DOF) measurement system based on total station by utilizing its advantages of long range and relative high accuracy. The cooperative target sensor, which is mainly composed of a pinhole prism, an industrial lens, a camera and a biaxial inclinometer, is designed to be portable in use. Subsequently, a precise mathematical model is proposed from the input variables observed by total station, imaging system and inclinometer to the output six pose variables. The model must be calibrated in two levels: the intrinsic parameters of imaging system, and the rotation matrix between coordinate systems of the camera and the inclinometer. Then corresponding approaches are presented. For the first level, we introduce a precise two-axis rotary table as a calibration reference. And for the second level, we propose a calibration method by varying the pose of a rigid body with the target sensor and a reference prism on it. Finally, through simulations and various experiments, the feasibilities of the measurement model and calibration methods are validated, and the measurement accuracy of the system is evaluated. (paper)

  19. Simple Numerical Method for Kinetical Investigation of Planar Mechanical Systems with Two Degrees of Freedom

    Directory of Open Access Journals (Sweden)

    István Bíró


    Full Text Available The aim of this article is to demonstrate the application of a simple numerical method which is suitable for motion analysis of different mechanical systems. For mechanical engineer students it is important task. Mechanical systems consisting of rigid bodies are linked to each other by different constraints. Kinematical and kinetical analysis of them leads to integration of second order differential equations. In this way the kinematical functions of parts of mechanical systems can be determined. Degrees of freedom of the mechanical system increase as a result of built-in elastic parts. Numerical methods can be applied to solve such problems. The simple numerical method will be demonstrated in MS Excel by author by the aid of two examples. MS Excel is a quite useful tool for mechanical engineers because easy to use it and details can be seen moreover failures can be noticed. Some parts of results obtained by using the numerical method were checked by analytical way. The published method can be used in higher education for mechanical engineer students.

  20. Closed fluid system without moving parts controls temperature (United States)

    Stenger, F. J.


    Closed fluid system maintains a constant temperature in an insulated region without the use of any moving parts. Within the system, the energy for thermodynamic cycling of two-phase heat transfer fluid and a hydraulic fluid is entirely supplied by the heat generated in the thermally insulated region.

  1. Design and optimization for the occupant restraint system of vehicle based on a single freedom model (United States)

    Zhang, Junyuan; Ma, Yue; Chen, Chao; Zhang, Yan


    Throughout the vehicle crash event, the interactions between vehicle, occupant, restraint system (VOR) are complicated and highly non-linear. CAE and physical tests are the most widely used in vehicle passive safety development, but they can only be done with the detailed 3D model or physical samples. Often some design errors and imperfections are difficult to correct at that time, and a large amount of time will be needed. A restraint system concept design approach which based on single-degree-of-freedom occupant-vehicle model (SDOF) is proposed in this paper. The interactions between the restraint system parameters and the occupant responses in a crash are studied from the view of mechanics and energy. The discrete input and the iterative algorithm method are applied to the SDOF model to get the occupant responses quickly for arbitrary excitations (impact pulse) by MATLAB. By studying the relationships between the ridedown efficiency, the restraint stiffness, and the occupant response, the design principle of the restraint stiffness aiming to reduce occupant injury level during conceptual design is represented. Higher ridedown efficiency means more occupant energy absorbed by the vehicle, but the research result shows that higher ridedown efficiency does not mean lower occupant injury level. A proper restraint system design principle depends on two aspects. On one hand, the restraint system should lead to as high ridedown efficiency as possible, and at the same time, the restraint system should maximize use of the survival space to reduce the occupant deceleration level. As an example, an optimization of a passenger vehicle restraint system is designed by the concept design method above, and the final results are validated by MADYMO, which is the most widely used software in restraint system design, and the sled test. Consequently, a guideline and method for the occupant restraint system concept design is established in this paper.

  2. Freedom Project

    Directory of Open Access Journals (Sweden)

    Alejandra Suarez


    Full Text Available Freedom Project trains prisoners in nonviolent communication and meditation. Two complementary studies of its effects are reported in this article. The first study is correlational; we found decreased recidivism rates among prisoners trained by Freedom Project compared with recidivism rates in Washington state. The second study compared trained prisoners with a matched-pair control group and found improvement in self-reported anger, self-compassion, and certain forms of mindfulness among the trained group. Ratings of role-plays simulating difficult interactions show increased social skills among the group trained by Freedom Project than in the matched controls.

  3. Space Station Freedom (SSF) Data Management System (DMS) performance model data base (United States)

    Stovall, John R.


    The purpose of this document was originally to be a working document summarizing Space Station Freedom (SSF) Data Management System (DMS) hardware and software design, configuration, performance and estimated loading data from a myriad of source documents such that the parameters provided could be used to build a dynamic performance model of the DMS. The document is published at this time as a close-out of the DMS performance modeling effort resulting from the Clinton Administration mandated Space Station Redesign. The DMS as documented in this report is no longer a part of the redesigned Space Station. The performance modeling effort was a joint undertaking between the National Aeronautics and Space Administration (NASA) Johnson Space Center (JSC) Flight Data Systems Division (FDSD) and the NASA Ames Research Center (ARC) Spacecraft Data Systems Research Branch. The scope of this document is limited to the DMS core network through the Man Tended Configuration (MTC) as it existed prior to the 1993 Clinton Administration mandated Space Station Redesign. Data is provided for the Standard Data Processors (SDP's), Multiplexer/Demultiplexers (MDM's) and Mass Storage Units (MSU's). Planned future releases would have added the additional hardware and software descriptions needed to describe the complete DMS. Performance and loading data through the Permanent Manned Configuration (PMC) was to have been included as it became available. No future releases of this document are presently planned pending completion of the present Space Station Redesign activities and task reassessment.

  4. Embodied freedom

    Directory of Open Access Journals (Sweden)

    H.G. Geertsema


    Full Text Available In this article I explore the relationship between freedom and embodiment. Firstly I argue that freedom is an essential part of our being human, whatever science might say, and should be understood as the possibility to be ourselves. I propose an understanding that starts from the perspective of the second person. In the second part I analyse the writing of a scientific article as a case study of the experience of freedom in a concrete practice. I show how normative elements are a necessary part of such a practice. In the third part I argue that the “free agent” is in fact the concrete person who acts and thinks. I also discuss the place of causation. In the final part I elaborate on the view of the person, as understood from a second person perspective, and on the meaning of freedom, taking my starting point in the biblical understanding.

  5. Disaggregating Corporate Freedom of Religion

    DEFF Research Database (Denmark)

    Lægaard, Sune


    to religion as a separate and independent jurisdiction with its own system of law over which religious groups are sovereign. I discuss the relationship between, on the one hand, ordinary rights of freedom of association and freedom of religion and, on the other hand, this idea of corporate freedom of religion...

  6. Real-time graphics for the Space Station Freedom cupola, developed in the Systems Engineering Simulator (United States)

    Red, Michael T.; Hess, Philip W.


    Among the Lyndon B. Johnson Space Center's responsibilities for Space Station Freedom is the cupola. Attached to the resource node, the cupola is a windowed structure that will serve as the space station's secondary control center. From the cupola, operations involving the mobile service center and orbital maneuvering vehicle will be conducted. The Systems Engineering Simulator (SES), located in building 16, activated a real-time man-in-the-loop cupola simulator in November 1987. The SES cupola is an engineering tool with the flexibility to evolve in both hardware and software as the final cupola design matures. Two workstations are simulated with closed-circuit television monitors, rotational and translational hand controllers, programmable display pushbuttons, and graphics display with trackball and keyboard. The displays and controls of the SES cupola are driven by a Silicon Graphics Integrated Raster Imaging System (IRIS) 4D/70 GT computer. Through the use of an interactive display builder program, SES, cupola display pages consisting of two dimensional and three dimensional graphics are constructed. These display pages interact with the SES via the IRIS real-time graphics interface. The focus is on the real-time graphics interface applications software developed on the IRIS.

  7. Safety features of subcritical fluid fueled systems

    Energy Technology Data Exchange (ETDEWEB)

    Bell, C.R. [Los Alamos National Laboratory, NM (United States)


    Accelerator-driven transmutation technology has been under study at Los Alamos for several years for application to nuclear waste treatment, tritium production, energy generation, and recently, to the disposition of excess weapons plutonium. Studies and evaluations performed to date at Los Alamos have led to a current focus on a fluid-fuel, fission system operating in a neutron source-supported subcritical mode, using molten salt reactor technology and accelerator-driven proton-neutron spallation. In this paper, the safety features and characteristics of such systems are explored from the perspective of the fundamental nuclear safety objectives that any reactor-type system should address. This exploration is qualitative in nature and uses current vintage solid-fueled reactors as a baseline for comparison. Based on the safety perspectives presented, such systems should be capable of meeting the fundamental nuclear safety objectives. In addition, they should be able to provide the safety robustness desired for advanced reactors. However, the manner in which safety objectives and robustness are achieved is very different from that associated with conventional reactors. Also, there are a number of safety design and operational challenges that will have to be addressed for the safety potential of such systems to be credible.

  8. Safety features of subcritical fluid fueled systems

    International Nuclear Information System (INIS)

    Bell, Charles R.


    Accelerator-driven transmutation technology has been under study at Los Alamos for several years for application to nuclear waste treatment, tritium production, energy generation, and recently, to the disposition of excess weapons plutonium. Studies and evaluations performed to date at Los Alamos have led to a current focus on a fluid-fuel, fission system operating in a neutron source-supported subcritical mode, using molten salt reactor technology and accelerator-driven proton-neutron spallation. In this paper, the safety features and characteristics of such systems are explored from the perspective of the fundamental nuclear safety objectives that any reactor-type system should address. This exploration is qualitative in nature and uses current vintage solid-fueled reactors as a baseline for comparison. Based on the safety perspectives presented, such systems should be capable of meeting the fundamental nuclear safety objectives. In addition, they should be able to provide the safety robustness desired for advanced reactors. However, the manner in which safety objectives and robustness are achieved is very different from that associated with conventional reactors. Also, there are a number of safety design and operational challenges that will have to be addressed for the safety potential of such systems to be credible

  9. Safety features of subcritical fluid fueled systems

    International Nuclear Information System (INIS)

    Bell, C.R.


    Accelerator-driven transmutation technology has been under study at Los Alamos for several years for application to nuclear waste treatment, tritium production, energy generation, and recently, to the disposition of excess weapons plutonium. Studies and evaluations performed to date at Los Alamos have led to a current focus on a fluid-fuel, fission system operating in a neutron source-supported subcritical mode, using molten salt reactor technology and accelerator-driven proton-neutron spallation. In this paper, the safety features and characteristics of such systems are explored from the perspective of the fundamental nuclear safety objectives that any reactor-type system should address. This exploration is qualitative in nature and uses current vintage solid-fueled reactors as a baseline for comparison. Based on the safety perspectives presented, such systems should be capable of meeting the fundamental nuclear safety objectives. In addition, they should be able to provide the safety robustness desired for advanced reactors. However, the manner in which safety objectives and robustness are achieved in very different from that associated with conventional reactors. Also, there are a number of safety design and operational challenges that will have to be addressed for the safety potential of such systems to be credible

  10. High gliding fluid power generation system with fluid component separation and multiple condensers (United States)

    Mahmoud, Ahmad M; Lee, Jaeseon; Radcliff, Thomas D


    An example power generation system includes a vapor generator, a turbine, a separator and a pump. In the separator, the multiple components of the working fluid are separated from each other and sent to separate condensers. Each of the separate condensers is configured for condensing a single component of the working fluid. Once each of the components condense back into a liquid form they are recombined and exhausted to a pump that in turn drives the working fluid back to the vapor generator.

  11. Freedom and Association


    Hill, Christopher Leslie Gowens


    The project Freedom and Association is a flexible, fluid, and personal investment in practice that loosens forms of language and opens up structures of value that cohere onto words and objects. The non-fixed, process-based nature of the practical component of the research is extended in an understanding of post anarchism - as an ongoing, lived experience of the everyday and of friendship. I define anarchism as the rejection of dominant power structures and as pertaini...

  12. Fluid design studies of integrated modular engine system (United States)

    Frankenfield, Bruce; Carek, Jerry


    A study was performed to develop a fluid system design and show the feasibility of constructing an integrated modular engine (IME) configuration, using an expander cycle engine. The primary design goal of the IME configuration was to improve the propulsion system reliability. The IME fluid system was designed as a single fault tolerant system, while minimizing the required fluid components. This study addresses the design of the high pressure manifolds, turbopumps and thrust chambers for the IME configuration. A physical layout drawing was made, which located each of the fluid system components, manifolds and thrust chambers. Finally, a comparison was made between the fluid system designs of an IME system and a non-network (clustered) engine system.

  13. Academic Freedom. (United States)

    Tobin, Brian G.

    The strength of academic freedom has always depended upon historical circumstances. In the United States, higher education began with institutions founded and controlled by religious sects. The notion of who gets educated and to what ends expanded as American democracy expanded. By the 1980's, legitimate calls for equality became a general…

  14. Intellectual Freedom (United States)

    Knox, Emily


    Support for intellectual freedom, a concept codified in the American Library Association's Library Bill of Rights and Code of Ethics, is one of the core tenets of modern librarianship. According to the most recent interpretation of the Library Bill of Rights, academic librarians are encouraged to incorporate the principles of intellectual freedom…

  15. Development of a compact, fiber-coupled, six degree-of-freedom measurement system for precision linear stage metrology

    International Nuclear Information System (INIS)

    Yu, Xiangzhi; Gillmer, Steven R.; Woody, Shane C.; Ellis, Jonathan D.


    A compact, fiber-coupled, six degree-of-freedom measurement system which enables fast, accurate calibration, and error mapping of precision linear stages is presented. The novel design has the advantages of simplicity, compactness, and relatively low cost. This proposed sensor can simultaneously measure displacement, two straightness errors, and changes in pitch, yaw, and roll using a single optical beam traveling between the measurement system and a small target. The optical configuration of the system and the working principle for all degrees-of-freedom are presented along with the influence and compensation of crosstalk motions in roll and straightness measurements. Several comparison experiments are conducted to investigate the feasibility and performance of the proposed system in each degree-of-freedom independently. Comparison experiments to a commercial interferometer demonstrate error standard deviations of 0.33 μm in straightness, 0.14 μrad in pitch, 0.44 μradin yaw, and 45.8 μrad in roll.

  16. Stability of equilibrium solutions of Hamiltonian systems with n-degrees of freedom and single resonance in the critical case (United States)

    dos Santos, Fabio; Vidal, Claudio


    In this paper we give new results for the stability of one equilibrium solution of an autonomous analytic Hamiltonian system in a neighborhood of the equilibrium point with n-degrees of freedom. Our Main Theorem generalizes several results existing in the literature and mainly we give information in the critical cases (i.e., the condition of stability and instability is not fulfilled). In particular, our Main Theorem provides necessary and sufficient conditions for stability of the equilibrium solutions under the existence of a single resonance. Using analogous tools used in the Main Theorem for the critical case, we study the stability or instability of degenerate equilibrium points in Hamiltonian systems with one degree of freedom. We apply our results to the stability of Hamiltonians of the type of cosmological models as in planar as in the spatial case.

  17. Novel Fluid Preservation System, Phase I (United States)

    National Aeronautics and Space Administration — To address NASA's need for a method to preserve blood and urine samples from astronauts collected during flight, Chromologic (CL) proposes to develop a novel Fluid...

  18. Thermal fluids in low temperature systems. Part 2

    Energy Technology Data Exchange (ETDEWEB)

    Lynde, P.G.; Yonkers, E.D. [Albert Kahn Associates, Inc., Detroit, MI (United States)


    This article focuses on the lifeblood of these systems, the thermal transfer fluid itself. Low-temperature heat-transfer fluids are used to condition engine fluids, test chambers, cooling fluids, or a combination of these in environmental test facilities. To meet the specific test criteria, these fluids may be required to maintain pumpability and function with thermal efficiency at temperatures as low as {minus}120 F. This article presents information related to heat-transfer fluids used in low-temperature cooling applications. Three general groups of fluids are discussed: water-based antifreezes (ethylene and propylene glycol solutions); chlorinated solvents (methylene chloride and trichloroethylene); organic and synthetic coolants (diethylbenzene, two forms of dimethylpolysiloxane, heavy naphtha hydrotreated, and citrus terpene).

  19. Computer assistant test and consultive system for aircraft fluid element (United States)

    Liu, Jin-Ru

    The fluid bearing elements of an aircraft's control system are discussed in the context of aviation maintenance engineering. This paper explores the development of an artificially intelligent assistant to aid in the maintenance of hydraulic control systems.

  20. Fluid and structural-dynamic piping system analysis

    International Nuclear Information System (INIS)

    Korthauer, H.J.; Lange, H.; Rychlik, G.


    By means of the fluid and structural-dynamic analyses conducted, the cooling system was qualified for all fluid-dynamic processes in normal and anomalous operation and in case of accidents. The boundary conditions assumed by us for the fluid and structural-dynamic analyses were confirmed by the forces and movements measured time for some operating conditions as a function of time. Expensive hardware measures such as additional supports or replacement of Tees were not necessary as we combined the fluid and structural-dynamic analyses and then demonstrated safety of the supports, connected components and some of the piping elements as such. (author)

  1. Fluid transportation mechanisms by a coupled system of elastic membranes and magnetic fluids

    International Nuclear Information System (INIS)

    Ido, Y.; Tanaka, K.; Sugiura, Y.


    The basic properties of the fluid transportation mechanism that is produced by the coupled waves propagating along a thin elastic membrane covering a magnetic fluid layer in a shallow and long rectangular vessel are investigated. It is shown that the progressive magnetic field induced by the rectangular pulses generates sinusoidal vibration of the displacement of elastic membrane and makes the system work more efficiently than the magnetic field induced by the pulse-width-modulation method

  2. Methods and systems for integrating fluid dispensing technology with stereolithography (United States)

    Medina, Francisco; Wicker, Ryan; Palmer, Jeremy A.; Davis, Don W.; Chavez, Bart D.; Gallegos, Phillip L.


    An integrated system and method of integrating fluid dispensing technologies (e.g., direct-write (DW)) with rapid prototyping (RP) technologies (e.g., stereolithography (SL)) without part registration comprising: an SL apparatus and a fluid dispensing apparatus further comprising a translation mechanism adapted to translate the fluid dispensing apparatus along the Z-, Y- and Z-axes. The fluid dispensing apparatus comprises: a pressurized fluid container; a valve mechanism adapted to control the flow of fluid from the pressurized fluid container; and a dispensing nozzle adapted to deposit the fluid in a desired location. To aid in calibration, the integrated system includes a laser sensor and a mechanical switch. The method further comprises building a second part layer on top of the fluid deposits and optionally accommodating multi-layered circuitry by incorporating a connector trace. Thus, the present invention is capable of efficiently building single and multi-material SL fabricated parts embedded with complex three-dimensional circuitry using DW.

  3. Generalized Fluid System Simulation Program (GFSSP) Version 6 - General Purpose Thermo-Fluid Network Analysis Software (United States)

    Majumdar, Alok; Leclair, Andre; Moore, Ric; Schallhorn, Paul


    GFSSP stands for Generalized Fluid System Simulation Program. It is a general-purpose computer program to compute pressure, temperature and flow distribution in a flow network. GFSSP calculates pressure, temperature, and concentrations at nodes and calculates flow rates through branches. It was primarily developed to analyze Internal Flow Analysis of a Turbopump Transient Flow Analysis of a Propulsion System. GFSSP development started in 1994 with an objective to provide a generalized and easy to use flow analysis tool for thermo-fluid systems.

  4. Local Magnetism in Strongly Correlated Electron Systems with Orbital Degrees of Freedom (United States)

    Ducatman, Samuel Charles

    The central aim of my research is to explain the connection between the macroscopic behavior and the microscopic physics of strongly correlated electron systems with orbital degrees of freedom through the use of effective models. My dissertation focuses on the sub-class of these materials where electrons appear to be localized by interactions, and magnetic ions have well measured magnetic moments. This suggests that we can capture the low-energy physics of the material by employing a minimal model featuring localized spins which interact with each other through exchange couplings. I describe Fe1+y Te and beta-Li2IrO3 with effective models primarily focusing on the spins of the magnetic ions, in this case Fe and Ir, respectively. The goal with both materials is to gain insight and make predictions for experimentalists. In chapter 2, I focus on Fe1+yTe. I describe why we believe the magnetic ground state of this material, with an observed Bragg peak at Q +/- pi/2, pi/2), can be described by a Heisenberg model with 1st, 2nd, and 3rd neighbor interactions. I present two possible ground states of this model in the small J1 limit, the bicollinear and plaquette states. In order to predict which ground state the model prefers, I calculate the spin wave spectrum with 1/S corrections, and I find the model naturally selects the "plaquette state." I give a brief description of the ways this result could be tested using experimental techniques such as polarized neutron scattering. In chapter 3, I extend the model used in chapter 2. This is necessary because the Heisenberg model we employed cannot explain why Fe1+yTe undergoes a phase transition as y is increased. We add an additional elements to our calculation; we assume that electrons in some of the Fe 3D orbitals have selectively localized while others remain itinerant. We write a new Hamiltonian, where localized moments acquire a new long-range RKKY-like interaction from interactions with the itinerant electrons. We are

  5. The fluid systems for the SLD Cherenkov ring imaging detector

    International Nuclear Information System (INIS)

    Abe, K.; Hasegawa, K.; Hasegawa, Y.; Iwasaki, Y.; Suekane, F.; Yuta, H.; Baird, K.; Jacques, P.; Kalelkar, M.; Plano, R.; Stamer, P.; Word, G.; Bean, A.; Caldwell, D.O.; Duboscq, J.; Huber, J.; Lu, A.; Mathys, L.; McHugh, S.; Yellin, S.; Ben-David, R.; Manly, S.; Snyder, J.; Turk, J.; Cavalli-Sforza, M.; Coyle, P.; Coyne, D.; Gagnon, P.; Liu, X.; Schneider, M.; Williams, D.A.; Coller, J.; Shank, J.T.; Whitaker, J.S.; d'Oliveira, A.; Johnson, R.A.; Martinez, J.; Nussbaum, M.; Santha, A.K.S.; Sokoloff, M.D.; Stockdale, I.; Wilson, R.J.


    We describe the design and operation of the fluid delivery, monitor and control systems for the SLD barrel Cherenkov Ring Imaging Detector (CRID). The systems deliver drift gas (C 2 H 6 + TMAE), radiator gas (C 5 F 12 + N 2 ) and radiator liquid (C 6 F 14 ). Measured critical quantities such as electron lifetime in the drift gas and ultra-violet (UV) transparencies of the radiator fluids, together with the operational experience, are also reported

  6. Two degree of freedom internal model control-PID design for LFC of power systems via logarithmic approximations. (United States)

    Singh, Jay; Chattterjee, Kalyan; Vishwakarma, C B


    Load frequency controller has been designed for reduced order model of single area and two-area reheat hydro-thermal power system through internal model control - proportional integral derivative (IMC-PID) control techniques. The controller design method is based on two degree of freedom (2DOF) internal model control which combines with model order reduction technique. Here, in spite of taking full order system model a reduced order model has been considered for 2DOF-IMC-PID design and the designed controller is directly applied to full order system model. The Logarithmic based model order reduction technique is proposed to reduce the single and two-area high order power systems for the application of controller design.The proposed IMC-PID design of reduced order model achieves good dynamic response and robustness against load disturbance with the original high order system. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

  7. Smart Fluid System Dually Responsive to Light and Electric Fields: An Electrophotorheological Fluid. (United States)

    Yoon, Chang-Min; Jang, Yoonsun; Noh, Jungchul; Kim, Jungwon; Jang, Jyongsik


    Electrophotorheological (EPR) fluids, whose rheological activity is dually responsive to light and electric fields (E fields), is formulated by mixing photosensitive spiropyran-decorated silica (SP-sSiO 2 ) nanoparticles with zwitterionic lecithin and mineral oil. A reversible photorheological (PR) activity of the EPR fluid is developed via the binding and releasing mechanism of lecithin and merocyanine (MC, a photoisomerized form of SP) under ultraviolet (UV) and visible (VIS) light applications. Moreover, the EPR fluid exhibits an 8-fold higher electrorheological (ER) performance compared to the SP-sSiO 2 nanoparticle-based ER fluid (without lecithin) under an E field, which is attributed to the enhanced dielectric properties facilitated by the binding of the lecithin and SP molecules. Upon dual application of UV light and an E field, the EPR fluid exhibits high EPR performance (ca. 115.3 Pa) that far exceeds its separate PR (ca. 0.8 Pa) and ER (ca. 57.5 Pa) activities, because of the synergistic contributions of the PR and ER effects through rigid and fully connected fibril-like structures. Consequently, this study offers a strategy on formulation of dual-stimuli responsive smart fluid systems.

  8. Complex fluids in biological systems experiment, theory, and computation

    CERN Document Server


    This book serves as an introduction to the continuum mechanics and mathematical modeling of complex fluids in living systems. The form and function of living systems are intimately tied to the nature of surrounding fluid environments, which commonly exhibit nonlinear and history dependent responses to forces and displacements. With ever-increasing capabilities in the visualization and manipulation of biological systems, research on the fundamental phenomena, models, measurements, and analysis of complex fluids has taken a number of exciting directions. In this book, many of the world’s foremost experts explore key topics such as: Macro- and micro-rheological techniques for measuring the material properties of complex biofluids and the subtleties of data interpretation Experimental observations and rheology of complex biological materials, including mucus, cell membranes, the cytoskeleton, and blood The motility of microorganisms in complex fluids and the dynamics of active suspensions Challenges and solut...

  9. Magnetic nanofluids and magnetic composite fluids in rotating seal systems

    International Nuclear Information System (INIS)

    Borbath, T; Borbath, I; Boros, T; Bica, D; Vekas, L; Potencz, I


    Recent results are presented concerning the development of magnetofluidic leakage-free rotating seals for vacuum and high pressure gases, evidencing significant advantages compared to mechanical seals. The micro-pilot scale production of various types of magnetizable sealing fluids is shortly reviewed, in particular the main steps of the chemical synthesis of magnetic nanofluids and magnetic composite fluids with light hydrocarbon, mineral oil and synthetic oil carrier liquids. The behavior of different types of magnetizable fluids in the rotating sealing systems is analyzed. Design concepts, some constructive details and testing procedures of magnetofluidic rotating seals are presented such as the testing equipment. The main characteristics of several magnetofluidic sealing systems and their applications will be presented: vacuum deposition systems and liquefied gas pumps applications, mechanical and magnetic nanofluid combined seals, gas valves up to 40 bar equipped by rotating seal with magnetic nanofluids and magnetic composite fluids.


    Directory of Open Access Journals (Sweden)

    Stanislav Yu Kolmakov


    Full Text Available The article analyzes the features, similarities and differences of the legal systems of Russia and China and reveals that Russia is a more democratic state compared to China in the field of protection of the freedom of speech. The author concludes that Russia can influence China by methods of international treaties which allow cooperation between states with different state and social orders and by promoting the ideas of the freedom of expression through research exchanges.

  11. Floor response spectra for multi-degree-of-freedom systems by Fourier transform

    International Nuclear Information System (INIS)

    Scanlan, R.H.; Sachs, K.


    A method of generating floor response spectra from a given ground response spectrum is given. This time-saving approach makes use of Fourier spectrum techniques and the randomness of phase angles. In matrix form a structure having many degrees-of-freedom is described by the equation of motion with M, C, K as the mass-, damping-, and stiffness matrices and Z being the acceleration time history of the earthquake and I a direction vector. If the Fourier spectrum FZ of the ground motion is known, then by standard methods the Fourier spectrum of the equipment response can be obtained. The assumption of random phase angles for the synthetic time history Z seems reasonable. The response is then also a superposition of cosine waves. Good agreement with time history methods is obtained. This method is much faster than time history methods, which are being used in most applications

  12. Geometric integrator for Langevin systems with quaternion-based rotational degrees of freedom and hydrodynamic interactions (United States)

    Davidchack, R. L.; Ouldridge, T. E.; Tretyakov, M. V.


    We introduce new Langevin-type equations describing the rotational and translational motion of rigid bodies interacting through conservative and non-conservative forces and hydrodynamic coupling. In the absence of non-conservative forces, the Langevin-type equations sample from the canonical ensemble. The rotational degrees of freedom are described using quaternions, the lengths of which are exactly preserved by the stochastic dynamics. For the proposed Langevin-type equations, we construct a weak 2nd order geometric integrator that preserves the main geometric features of the continuous dynamics. The integrator uses Verlet-type splitting for the deterministic part of Langevin equations appropriately combined with an exactly integrated Ornstein-Uhlenbeck process. Numerical experiments are presented to illustrate both the new Langevin model and the numerical method for it, as well as to demonstrate how inertia and the coupling of rotational and translational motion can introduce qualitatively distinct behaviours.

  13. Generalized Fluid System Simulation Program (GFSSP) - Version 6 (United States)

    Majumdar, Alok; LeClair, Andre; Moore, Ric; Schallhorn, Paul


    The Generalized Fluid System Simulation Program (GFSSP) is a finite-volume based general-purpose computer program for analyzing steady state and time-dependent flow rates, pressures, temperatures, and concentrations in a complex flow network. The program is capable of modeling real fluids with phase changes, compressibility, mixture thermodynamics, conjugate heat transfer between solid and fluid, fluid transients, pumps, compressors, flow control valves and external body forces such as gravity and centrifugal. The thermo-fluid system to be analyzed is discretized into nodes, branches, and conductors. The scalar properties such as pressure, temperature, and concentrations are calculated at nodes. Mass flow rates and heat transfer rates are computed in branches and conductors. The graphical user interface allows users to build their models using the 'point, drag, and click' method; the users can also run their models and post-process the results in the same environment. The integrated fluid library supplies thermodynamic and thermo-physical properties of 36 fluids, and 24 different resistance/source options are provided for modeling momentum sources or sinks in the branches. Users can introduce new physics, non-linear and time-dependent boundary conditions through user-subroutine.

  14. Excited-state quantum phase transitions in systems with two degrees of freedom: Level density, level dynamics, thermal properties

    International Nuclear Information System (INIS)

    Stránský, Pavel; Macek, Michal; Cejnar, Pavel


    Quantum systems with a finite number of freedom degrees f develop robust singularities in the energy spectrum of excited states as the system’s size increases to infinity. We analyze the general form of these singularities for low f, particularly f=2, clarifying the relation to classical stationary points of the corresponding potential. Signatures in the smoothed energy dependence of the quantum state density and in the flow of energy levels with an arbitrary control parameter are described along with the relevant thermodynamical consequences. The general analysis is illustrated with specific examples of excited-state singularities accompanying the first-order quantum phase transition. -- Highlights: •ESQPTs found in infinite-size limit of systems with low numbers of freedom degrees f. •ESQPTs related to non-analytical evolutions of classical phase–space properties. •ESQPT signatures analyzed for general f, particularly f=2, extending known case f=1. •ESQPT signatures identified in smoothened density and flow of energy spectrum. •ESQPTs shown to induce a new type of thermodynamic anomalies

  15. Dynamic analysis of multibody system immersed in a fluid medium

    International Nuclear Information System (INIS)

    Wu, R.W.; Liu, L.K.; Levy, S.


    This paper is concerned primarily with the development and evaluation of an analysis method for the reponse prediction of immersed systems to seismic and other dynamic excitations. For immersed multibody systems, the hydrodynamic interaction causes coupled motion among the solid bodies. Also, under intense external excitations, impact between bodies may occur. The complex character of such systems inhibit the use of conventional analytical solutions in closed form. Therefore, approximate numerical schemes have been devised. For an incompressible, inviscid fluid, the hydrodynamic forces exerted by the fluid on solid bodies are determined to be linearly proportional to the acceleration of the vibrating solid bodies; i.e., the presence of the fluid only affects the inertia of the solid body system. A finite element computer program has been developed for computing this hydrodynamic (or added) mass effect. This program can be used to determine the hydrodynamic mass of a two-dimensional fluid field with solid bodies of arbitrary geometry. Triangular elements and linear pressure interpolation function are used to discretize the fluid region. The component element method is used to determine the dynamic response of the multibody system to externally applied mechanical loading or support excitation. The present analysis method for predicting the dynamic response of submerged multibody system is quite general and pertains to any number of solid bodies. However in this paper, its application is demonstrated only for 4 and 25 body systems. (Auth.)

  16. Development of fluid and I and C systems design technology

    International Nuclear Information System (INIS)

    Sim, Yoon Sub; Park, C. K.; Kim, S. O.


    LMR is the reactor type that makes utilization of uranium resource very efficiently and the necessity of construction of a LMR in 2020's has been raised. However, the design technology required for construction has not been secured domestically. To fulfill the necessity, study has been made for the LMR system design technology and conceptual design of KALIMER systems for fluid, instrumentation, control, and protection have been developed. Also the computer code systems for the design and analysis of the KALIMER fluid systems have been developed. These study results are to used as the starting point of the next phase LMR design technology development research

  17. Development of fluid and I and C systems design technology

    Energy Technology Data Exchange (ETDEWEB)

    Sim, Yoon Sub; Park, C. K.; Kim, S. O. [and others


    LMR is the reactor type that makes utilization of uranium resource very efficiently and the necessity of construction of a LMR in 2020's has been raised. However, the design technology required for construction has not been secured domestically. To fulfill the necessity, study has been made for the LMR system design technology and conceptual design of KALIMER systems for fluid, instrumentation, control, and protection have been developed. Also the computer code systems for the design and analysis of the KALIMER fluid systems have been developed. These study results are to used as the starting point of the next phase LMR design technology development research.

  18. Vector Control System Design for Four Degree-of-Freedom Dynamic Flexible Simulation of the Variable-Frequency Drive

    Directory of Open Access Journals (Sweden)

    Kladiev Sergey N.


    Full Text Available In the present work we investigate the control system development of the drive simulators to train driver/operator driving skills, taking into account the ever-changing terrain. In order to meet the required response of the four degree-of-freedom motion platform servomotor current studies have been focused on the vector control of the resistance motor angular velocity from the sensor being incremental encoder. In proposed system the standard security of the frequency converter is realized. It leads to overload capacity of two times within minutes determined by servomotor inertia. Further, we represent the algorithms: positional limitation, reliable acceleration and restraint, frequency break. As well as we demonstrate the position switches implement in software. As a result, the control system commands the control of the angular position of the platform in coordinates.

  19. Libertades económicas y derechos fundamentales. La libertad de empresa en el ordenamiento multinivel europeo || Economic Freedom and Fundamental Rights. Freedom to Conduct Business in the Multilevel European Legal System

    Directory of Open Access Journals (Sweden)

    Pedro Mercado Pacheco


    Full Text Available RESUMEN   La libertad de empresa es utilizada como pretexto para ilustrar las relaciones y jerarquías entre libertades económicas comunitarias y derechos fundamentales en el ordenamiento multinivel europeo. Su estrecha relación con las libertades económicas comunitarias y con el objetivo del mercado interior, han dotado a la libertad de empresa de una especial fortaleza a la hora de dirimir sus eventuales conflictos con otros derechos acogidos aparentemente en pie de igualdad en la reciente redefinición de los objetivos de la UE. Por otro lado, cuando esta primacía se transplanta al ordenamiento interno  se corre el riesgo de alterar los equilibrios del sistema de derechos de los Estados, anclados en el constitucionalismo del Estado social. ABSTRACT Freedom to conduct a business is used as a pretext to illustrate the relationships and hierarchies between Community economic freedoms and fundamental rights in the European multilevel legal system. The close relationship of this with the EU objective of the internal market and with Community economic freedoms, have provided it with a special strength when settling the possible conflicts with other rights recently welcomed into the redefinition of the objectives of the European Union on an equal footing. Furthermore, when this primacy is transplanted into national law it runs the risk of upsetting the balance of the system of states rights, anchored in the constitutionalism of the social state.

  20. Load converter interactions with the secondary system in the Space Station Freedom power management and distribution DC test bed (United States)

    Lebron, Ramon C.


    The NASA LeRC in Cleveland, Ohio, is responsible for the design, development, and assembly of the Space Station Freedom (SSF) Electrical Power System (EPS). In order to identify and understand system level issues during the SSF Program design and development phases, a system Power Management and Distribution (PMAD) DC test bed was assembled. Some of the objectives of this test bed facility are the evaluation of, system efficiency, power quality, system stability, and system protection and reconfiguration schemes. In order to provide a realistic operating scenario, dc Load Converter Units are used in the PMAD dc test bed to characterize the user interface with the power system. These units are dc to dc converters that provide the final system regulation before power is delivered to the load. This final regulation is required on the actual space station because the majority of user loads will require voltage levels different from the secondary bus voltage. This paper describes the testing of load converters in an end to end system environment (from solar array to loads) where their interactions and compatibility with other system components are considered. Some of the system effects of interest that are presented include load converters transient behavior interactions with protective current limiting switchgear, load converters ripple effects, and the effects of load converter constant power behavior with protective features such as foldback.

  1. Validation of CLIC Re-Adjustment System Based on Eccentric Cam Movers One Degree of Freedom Mock-Up

    CERN Document Server

    Kemppinen, J; Lackner, F


    Compact Linear Collider (CLIC) is a 48 km long linear accelerator currently studied at CERN. It is a high luminosity electron-positron collider with an energy range of 0.5-3 TeV. CLIC is based on a two-beam technology in which a high current drive beam transfers RF power to the main beam accelerating structures. The main beam is steered with quadrupole magnets. To reach CLIC target luminosity, the main beam quadrupoles have to be actively pre-aligned within 17 µm in 5 degrees of freedom and actively stabilised at 1 nm in vertical above 1 Hz. To reach the pre-alignment requirement as well as the rigidity required by nano-stabilisation, a system based on eccentric cam movers is proposed for the re-adjustment of the main beam quadrupoles. Validation of the technique to the stringent CLIC requirements was started with tests in one degree of freedom on an eccentric cam mover. This paper describes the dedicated mock-up as well as the tests and measurements carried out with it. Finally, the test results are present...

  2. Aristocratic Rebellion: Ruben Darío and the Creation of Artistic Freedom in the World-System

    Directory of Open Access Journals (Sweden)

    Roberto José Ortiz


    Full Text Available The late 19th struggle for artistic freedom in the capitalist world-system put the artist in a contradictory position. This contradiction is particularly relevant for writers of the periphery. Freedom or autonomy to pursue purely intellectual projects required a certain aristocratic defense of the value of art. At the same time, however, artists and intellectuals did confront structural subordination: they belonged, as Pierre Bourdieu explained, to the dominated fractions of the dominant class, subordinated both to the state and the bourgeoisie. The life of Nicaraguan Ruben Darío (1867–1916, probably the most well-known poet in Latin American history, provides a paradigmatic instance of this dilemma. Moreover, it sheds light into a dilemma particular to the peripheral intellectual. Peripheral writers, in the 19th century and still today, are subject to world-systemic hierarchies, even cultural ones. This double subordination is clear in the case of Ruben Darío. He was in a subordinated position not only vis-à-vis the national state and the bourgeoisie. Darío was also in a subordinated position, even if symbolic, in relation to those same intellectuals that Bourdieu celebrated as creators of the autonomy of culture in France. One can account for this complex of hierarchies only through a 'world-systems biography' approach. World-systems biographies clearly examine the dialectic of personal, national and global levels of social life. Moreover, it can uncover the core-periphery dialectic in the realm of artistic production. Thus, this world-systems biography approach is shown to be a useful framework through a brief analysis of Darío's life and work.

  3. Dynamical Analysis on Single Degree-of-Freedom Semiactive Control System by Using Fractional-Order Derivative

    Directory of Open Access Journals (Sweden)

    Yongjun Shen


    Full Text Available The single degree-of-freedom (SDOF system under the control of three semiactive methods is analytically studied in this paper, where a fractional-order derivative is used in the mathematical model. The three semiactive control methods are on-off control, limited relative displacement (LRD control, and relative control, respectively. The averaging method is adopted to provide an analytical study on the performance of the three different control methods. Based on the comparison between the analytical solutions with the numerical ones, it could be proved that the analytical solutions are accurate enough. The effects of the fractional-order parameters on the control performance, especially the relative and absolute displacement transmissibility, are analyzed. The research results indicate that the steady-state amplitudes of the three semiactive systems with fractional-order derivative in the model could be significantly reduced and the control performance can be greatly improved.

  4. Compensation for straightness measurement systematic errors in six degree-of-freedom motion error simultaneous measurement system. (United States)

    Cui, Cunxing; Feng, Qibo; Zhang, Bin


    The straightness measurement systematic errors induced by error crosstalk, fabrication and installation deviation of optical element, measurement sensitivity variation, and the Abbe error in six degree-of-freedom simultaneous measurement system are analyzed in detail in this paper. Models for compensating these systematic errors were established and verified through a series of comparison experiments with the Automated Precision Inc. (API) 5D measurement system, and the experimental results showed that the maximum deviation in straightness error measurement could be reduced from 6.4 to 0.9 μm in the x-direction, and 8.8 to 0.8 μm in the y-direction, after the compensation.

  5. Dynamic analysis of multibody system immersed in a fluid medium

    International Nuclear Information System (INIS)

    Wu, R.W.; Liu, L.K.; Levy, S.


    This paper is concerned primarily with the development and evaluation of an analysis method for the response prediction of immersed multibody systems to seismic and other dynamic excitations. For immersed multibody systems to seismic and other dynamic excitations. For immersed multibody systems, the hydrodynamic interaction causes coupled motion among the solid bodies. Also, under intense external excitations, impact between bodies may occur. The complex character of such systems inhibit the use of conventional analytical solutions in closed form. Therefore, approximate numerical schemes have been devised. For an incompressible, inviscid fluid, the hydrodynamic forces exerted by the fluid on solid bodies are determined to be linearly proportional to the acceleration of the vibrating solid bodies; i.e., the presence of the fluid only affects the inertia of the solid body system. A finite element computer program has been developed for computing this hydrodynamic (or added) mass effect. This program can be used to determine the hydrodynamic mass of a two-dimensional fluid field with solid bodies of arbitrary geometry. Triangular elements and linear pressure interpolation function are used to discretize the fluid region. The component element method is used to determine the dynamic response of the multibody system to externally applied mechanical loading or support excitation. In the component element method, each structural body is modeled by component elements of conceptual spring-damper type. This method is particularly advantageous for systems having nonlinearities. Direct timewise numerical integration scheme is used to solve the governing dynamic equation of the system. Analytical study is carried out and compared with an experimental result for the forced vibration of 4 simply supported beams in water. Also studied is a case of 25 (5x5) beams within a square fluid-filled container by using two different approaches

  6. ISS-CREAM Thermal and Fluid System Design and Analysis (United States)

    Thorpe, Rosemary S.


    Thermal and Fluids Analysis Workshop (TFAWS), Silver Spring MD NCTS 21070-15. The ISS-CREAM (Cosmic Ray Energetics And Mass for the International Space Station) payload is being developed by an international team and will provide significant cosmic ray characterization over a long time frame. Cold fluid provided by the ISS Exposed Facility (EF) is the primary means of cooling for 5 science instruments and over 7 electronics boxes. Thermal fluid integrated design and analysis was performed for CREAM using a Thermal Desktop model. This presentation will provide some specific design and modeling examples from the fluid cooling system, complex SCD (Silicon Charge Detector) and calorimeter hardware, and integrated payload and ISS level modeling. Features of Thermal Desktop such as CAD simplification, meshing of complex hardware, External References (Xrefs), and FloCAD modeling will be discussed.

  7. Generalized Fluid System Simulation Program, Version 5.0-Educational (United States)

    Majumdar, A. K.


    The Generalized Fluid System Simulation Program (GFSSP) is a finite-volume based general-purpose computer program for analyzing steady state and time-dependent flow rates, pressures, temperatures, and concentrations in a complex flow network. The program is capable of modeling real fluids with phase changes, compressibility, mixture thermodynamics, conjugate heat transfer between solid and fluid, fluid transients, pumps, compressors and external body forces such as gravity and centrifugal. The thermofluid system to be analyzed is discretized into nodes, branches, and conductors. The scalar properties such as pressure, temperature, and concentrations are calculated at nodes. Mass flow rates and heat transfer rates are computed in branches and conductors. The graphical user interface allows users to build their models using the point, drag and click method; the users can also run their models and post-process the results in the same environment. The integrated fluid library supplies thermodynamic and thermo-physical properties of 36 fluids and 21 different resistance/source options are provided for modeling momentum sources or sinks in the branches. This Technical Memorandum illustrates the application and verification of the code through 12 demonstrated example problems.

  8. Fluid dynamical approach to spinodal instabilities in finite nuclear systems

    International Nuclear Information System (INIS)

    Jacquot, B.; Chomaz, Ph.; Ayik, S.; Colonna, M.


    The growth of instabilities of finite nuclear systems at low densities is investigated using a fluid dynamical approach. For a sufficiently large source several multiple modes up to an ultraviolet cut-off become unstable with nearly the same growth rate, indicating that the system may develop towards different fragmentation channels with nearly equal probability. (author)

  9. Freedom as Satisfaction?

    DEFF Research Database (Denmark)

    Rostbøll, Christian Fogh


    with harmony in one's entire volitional system, Frankfurt may solve the infi nite regress objection but he does so at the cost of ending up with a description of freedom, which comes very close to being identical to his own description of the wanton. Frankfurt's account leaves open the question of whether......This article is a critical assessment of Harry Frankfurt's hierarchical theory of freedom. It spells out and distinguishes several different and irreconcilable conceptions of freedom present in Frankfurt's work. I argue that Frankfurt is ambiguous in his early formulation as to what conception...... of freedom of the will the hierarchical theory builds on, an avoidability or a satisfaction conception. This ambiguity causes problems in his later attempts to respond to the objections of wantonness of second-order desires and of infi nite regress. With his more recent idea of freedom as being satisfi ed...

  10. Fluid Delivery System For Capillary Electrophoretic Applications. (United States)

    Li, Qingbo; Liu, Changsheng; Kane, Thomas E.; Kernan, John R.; Sonnenschein, Bernard; Sharer, Michael V.


    An automated electrophoretic system is disclosed. The system employs a capillary cartridge having a plurality of capillary tubes. The cartridge has a first array of capillary ends projecting from one side of a plate. The first array of capillary ends are spaced apart in substantially the same manner as the wells of a microtitre tray of standard size. This allows one to simultaneously perform capillary electrophoresis on samples present in each of the wells of the tray. The system includes a stacked, dual carrousel arrangement to eliminate cross-contamination resulting from reuse of the same buffer tray on consecutive executions from electrophoresis. The system also has a gel delivery module containing a gel syringe/a stepper motor or a high pressure chamber with a pump to quickly and uniformly deliver gel through the capillary tubes. The system further includes a multi-wavelength beam generator to generate a laser beam which produces a beam with a wide range of wavelengths. An off-line capillary reconditioner thoroughly cleans a capillary cartridge to enable simultaneous execution of electrophoresis with another capillary cartridge. The streamlined nature of the off-line capillary reconditioner offers the advantage of increased system throughput with a minimal increase in system cost.

  11. Investigation of a working fluid for cryogenic energy storage systems (United States)

    Wojcieszak, P.; Poliński, J.; Chorowski, M.


    Cryogenic energy storage (CES) systems are promising alternatives to existing electrical energy storage technologies such as a pumped hydroelectric storage (PHS) or compressed air energy storage (CAES). In CES systems, excess electrical energy is used to liquefy a cryogenic fluid. The liquid can be stored in large cryogenic tanks for a long time. When a demand for the electricity is high, the liquid cryogen is pumped to high pressure and then warmed in a heat exchanger using ambient temperature or an available waste heat source. The vaporized cryogen is then used to drive a turbine and generate the electricity. Most research on cryogenic energy storage focuses on liquid air energy storage, as atmospheric air is widely available and therefore it does not limit a location of the energy storage plant. Nevertheless, CES with other gases as the working fluids can exhibit a higher efficiency. In this research a performance analysis of simple CES systems with several working fluids was performed.

  12. Optimal Linear Quadratic Regulators for Control of Nonlinear Mechanical Systems with Redundant Degrees-of-Freedom (United States)

    Arimoto, Suguru

    An optimal regulator problem for endpoint position control of a robot arm with (or without) redundancy in its total degrees-of-freedom (DOF) is solved by combining Riemannian geometry with nonlinear control theory. Given a target point, within the task-space, that the arm endpoint should reach, a task-space position feedback with joint damping is shown to asymptotically stabilize reaching movements even if the number of DOF of the arm is greater than the dimension of the task space and thereby the inverse kinematics is ill-posed. Usually the speed of convergence of the endpoint trajectory is unsatisfactory, depending on the choice of feedback gains for joint damping. Hence, to speed up the convergence without incurring further energy consumption, an optimal control design for minimizing a performance index composed of an integral of joint dissipation energy plus a linear quadratic form of the task-space control input and output is introduced. It is then shown that the Hamilton-Jacobi-Bellman equation derived from the principle of optimality is solvable in control variables and the Hamilton-Jacobi equation itself has an explicit solution. Although the state of the original dynamics (the Euler-Lagrange equation) with DOF-redundancy contains uncontrollable and unobservable manifolds, the dynamics satisfies a nonlinear version of the Kalman-Yakubovich-Popov lemma and the task-space input-output passivity. An inverse problem of optimal regulator design for robotic arms under the effect of gravity is also tackled by combining Riemannian geometry with passivity-based control theory.

  13. External induced contamination environment assessment for Space Station Freedom (United States)

    Leger, Lubert; Ehlers, Horst; Hakes, Charles; Theall, Jeff; Soares, Carlos


    An assessment of the Space Station Freedom performance as affected by the external induced contamination environment is in progress. The assessment procedure involves comparing the Space Station Freedom external contamination requirements, SSP 30426, Revision B (1991), with calculated molecular deposition, molecular column density, and other effects from potential sources of contamination. The current assessment comprises discussions of Space Shuttle proximity operations, Space Shuttle waste-water dumps (while docked to the Space Station), Space Station fluid and waste-gas venting, system gas leakage, external material outgassing, and a combined contamination assessment. This performance assessment indicates that Space Station Freedom contamination requirements are realistic and can be satisfied when all contamination sources are included.

  14. Systems and methods for multi-fluid geothermal energy systems (United States)

    Buscheck, Thomas A.


    A method for extracting geothermal energy from a geothermal reservoir formation. A production well is used to extract brine from the reservoir formation. At least one of nitrogen (N.sub.2) and carbon dioxide (CO.sub.2) may be used to form a supplemental working fluid which may be injected into a supplemental working fluid injection well. The supplemental working fluid may be used to augment a pressure of the reservoir formation, to thus drive a flow of the brine out from the reservoir formation.

  15. LHC II system sensitivity to magnetic fluids

    CERN Document Server

    Cotae, Vlad


    Experiments have been designed to reveal the influences of ferrofluid treatment and static magnetic field exposure on the photosynthetic system II, where the light harvesting complex (LHC II) controls the ratio chlorophyll a/ chlorophyll b (revealing, indirectly, the photosynthesis rate). Spectrophotometric measurement of chlorophyll content revealed different influences for relatively low ferrofluid concentrations (10-30 mul/l) in comparison to higher concentrations (70-100 mul/l). The overlapped effect of the static magnetic field shaped better the stimulatory ferrofluid action on LHC II system in young poppy plantlets.

  16. Shuttle valves and system for fluid control

    Energy Technology Data Exchange (ETDEWEB)

    Caralli, M. J.; Friedline, G. W.


    An apparatus system for drying gases to provide a reverse flow to and from a pair of absorbent beds is automatically solely controlled by a unitary inlet logic shuttle valve unit and by a unitary outlet logic shuttle valve unit. Each valve unit employs positive acting slide valve elements that operate in a smooth and effective manner.

  17. Fluid biomarkers in multiple system atrophy

    DEFF Research Database (Denmark)

    Laurens, Brice; Constantinescu, Radu; Freeman, Roy


    Despite growing research efforts, no reliable biomarker currently exists for the diagnosis and prognosis of multiple system atrophy (MSA). Such biomarkers are urgently needed to improve diagnostic accuracy, prognostic guidance and also to serve as efficacy measures or surrogates of target engagem...

  18. Shuttle valves and system for fluid control

    International Nuclear Information System (INIS)

    Caralli, M. J.; Friedline, G. W.


    An apparatus system for drying gases to provide a reverse flow to and from a pair of absorbent beds is automatically solely controlled by a unitary inlet logic shuttle valve unit and by a unitary outlet logic shuttle valve unit. Each valve unit employs positive acting slide valve elements that operate in a smooth and effective manner

  19. Generalized Fluid System Simulation Program, Version 6.0 (United States)

    Majumdar, A. K.; LeClair, A. C.; Moore, R.; Schallhorn, P. A.


    The Generalized Fluid System Simulation Program (GFSSP) is a general purpose computer program for analyzing steady state and time-dependent flow rates, pressures, temperatures, and concentrations in a complex flow network. The program is capable of modeling real fluids with phase changes, compressibility, mixture thermodynamics, conjugate heat transfer between solid and fluid, fluid transients, pumps, compressors, and external body forces such as gravity and centrifugal. The thermofluid system to be analyzed is discretized into nodes, branches, and conductors. The scalar properties such as pressure, temperature, and concentrations are calculated at nodes. Mass flow rates and heat transfer rates are computed in branches and conductors. The graphical user interface allows users to build their models using the 'point, drag, and click' method; the users can also run their models and post-process the results in the same environment. Two thermodynamic property programs (GASP/WASP and GASPAK) provide required thermodynamic and thermophysical properties for 36 fluids: helium, methane, neon, nitrogen, carbon monoxide, oxygen, argon, carbon dioxide, fluorine, hydrogen, parahydrogen, water, kerosene (RP-1), isobutene, butane, deuterium, ethane, ethylene, hydrogen sulfide, krypton, propane, xenon, R-11, R-12, R-22, R-32, R-123, R-124, R-125, R-134A, R-152A, nitrogen trifluoride, ammonia, hydrogen peroxide, and air. The program also provides the options of using any incompressible fluid with constant density and viscosity or ideal gas. The users can also supply property tables for fluids that are not in the library. Twenty-four different resistance/source options are provided for modeling momentum sources or sinks in the branches. These options include pipe flow, flow through a restriction, noncircular duct, pipe flow with entrance and/or exit losses, thin sharp orifice, thick orifice, square edge reduction, square edge expansion, rotating annular duct, rotating radial duct

  20. Hierarchical Robot Control System and Method for Controlling Select Degrees of Freedom of an Object Using Multiple Manipulators (United States)

    Abdallah, Muhammad E. (Inventor); Platt, Robert (Inventor); Wampler, II, Charles W. (Inventor)


    A robotic system includes a robot having manipulators for grasping an object using one of a plurality of grasp types during a primary task, and a controller. The controller controls the manipulators during the primary task using a multiple-task control hierarchy, and automatically parameterizes the internal forces of the system for each grasp type in response to an input signal. The primary task is defined at an object-level of control, e.g., using a closed-chain transformation, such that only select degrees of freedom are commanded for the object. A control system for the robotic system has a host machine and algorithm for controlling the manipulators using the above hierarchy. A method for controlling the system includes receiving and processing the input signal using the host machine, including defining the primary task at the object-level of control, e.g., using a closed-chain definition, and parameterizing the internal forces for each of grasp type.

  1. Numerical analysis of complex fluid-flow systems (United States)

    Holland, R. L.


    Very flexible computer-assisted numerical analysis is used to solve dynamic fluid-flow equations characterizing computer-controlled heat dissipation system developed for Space lab. Losses caused by bends, ties, fittings, valves, and like are easily included, and analysis can solve both steady-state and transient cases. It can also interact with parallel thermal analysis.

  2. More efficient fluid power systems using variable displacement hydraulic motors


    Biedermann, Olaf; Engelhardt, Jörg; Geerling, Gerhard


    The approach and landing phase is dimensioning for today’s aircraft fluid power systems. In this flight phase, large hydraulic consumers (flaps/slats, landing gear) have to be operated while the available hydraulic power reaches it’s minimum due to the reduced engine speed. During most of the flight the installed resources exceed the hydraulic power requirements by far; resulting in a low overall-efficiency. This paper presents an approach to increase the efficiency of today’s fluid power sys...

  3. Trajectory tracking for two-degree of freedom helicopter system using a controller-disturbance observer integrated design. (United States)

    Zarei, Amin; Poutari, M Sedigh; Barakati, S Masoud


    Trajectory tracking control for helicopters, which are widely used in severe situations such as military and rescue missions, is a challenging field of research. In helicopter system, the stability problem and predefined trajectories tracking are main challenges, especially in the presence of external disturbances and dynamic model uncertainties. Hence, a robust control design is needed for tracking the desired references. There has been a lot of motivation for solving these problems with simpler methods and also reducing the couplings in the helicopter system to achieve better performance, as the presented paper attempts to fill these gaps. This paper focuses on designing control laws for two-degree of freedom helicopter system while assuring the closed-loop stability. A nonlinear disturbance observer-based control (NDOBC) is designed for attenuating the effects of exogenous disturbances. Trajectory tracking controller and nonlinear disturbance observer are formulated in the form of two linear matrix inequality (LMI) problems. The closed-loop system stability, including controller and observer, is investigated by Lyapunov theorem. The effectiveness of the proposed design for tracking the trajectories (vertical flight and pitch angle rotor blade) and disturbance estimation is verified by simulation results. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

  4. The Meaning of Freedom

    Directory of Open Access Journals (Sweden)

    Luis Eduardo Hoyos


    Full Text Available In the article it is pretended to prepare the conceptual field for the correct use of the attribution of freedom. It is defended the importance to consider the complementarity of freedom of action and freedom of the will and it is argued for a non-metaphysical conception of adscription of freedom. The adequate use of the attribution of freedom is social and normative. This means additionally that the freedom is not a presupposition of the moral responsibility and the authorship, but on the contrary the moral responsibility and the authorship are presuppositions of the attribution of freedom.

  5. Retention Characteristics for Multiple-PhaseFluid Systems

    Directory of Open Access Journals (Sweden)

    Chia-Hsing Tsai Gour-Tsyh Yeh


    Full Text Available The key objective of this paper is to point out that a widely used constitutive relationship between the degrees of saturation and capillary pressures for three-phasefluids over the past twenty five years has resulted in an undue constraint. To our knowledge, this constraint is neither physically justifiable nor is it theoretically supported. The discovery of the undue constraint leads this investigation to develop a viable parametric model to describe the constitutive relationship for a system of multiple fluids. Based on the physical consideration wherein fluid wettability follows a sequence, the proposed parametric model can be easily applied to any system of L arbitrary fluids. Three aspects are presented to confirm the plausibility and completeness of the model. First, the proposed closed-form expression of the saturation-capillary pressure head relationship is identical to van Genuchten¡¦s renowned model for two-phasefluid systems. Second, a constraint appearing in the widely used model is alleviated in the proposed model. Third, seven hypothetical examples are used to demonstrate that there is no need to impose the constraint on the sequence of capillary pressures. The results show the plausibility and completeness of the model for systems of multiple fluids. The proposed parametric model is a feasible analytic model which provides a generalized saturation-capillary pressure head relationship for any system with regard to multiple fluids. Hopefully, this study will pave a way for others to conduct experiments to validate the model further or develop other better non-constrained models based on experimental evidence.\\

  6. Linking rigid multibody systems via controllable thin fluid films

    DEFF Research Database (Denmark)

    Estupinan, Edgar Alberto; Santos, Ilmar


    compressor. The system of equations is numerically solved for the case when the system operates with conventional hydrodynamic lubrication and for several cases of the bearing operating under controlled hybrid lubrication conditions. The analysis of the results is carried out with focus on the behaviour......This work deals with the mathematical modelling of multibody systems interconnected via thin fluid films. The dynamics of the fluid films can be actively controlled by means of different types of actuators, allowing significant vibration reduction of the system components. In this framework......, this paper gives a theoretical contribution to the combined fields of fluid–structure interaction and vibration control. The methodology is applied to a reciprocating linear compressor, where the dynamics of the mechanical components are described with help of multibody dynamics. The crank is linked...

  7. Computational Fluid and Particle Dynamics in the Human Respiratory System

    CERN Document Server

    Tu, Jiyuan; Ahmadi, Goodarz


    Traditional research methodologies in the human respiratory system have always been challenging due to their invasive nature. Recent advances in medical imaging and computational fluid dynamics (CFD) have accelerated this research. This book compiles and details recent advances in the modelling of the respiratory system for researchers, engineers, scientists, and health practitioners. It breaks down the complexities of this field and provides both students and scientists with an introduction and starting point to the physiology of the respiratory system, fluid dynamics and advanced CFD modeling tools. In addition to a brief introduction to the physics of the respiratory system and an overview of computational methods, the book contains best-practice guidelines for establishing high-quality computational models and simulations. Inspiration for new simulations can be gained through innovative case studies as well as hands-on practice using pre-made computational code. Last but not least, students and researcher...

  8. Modular microfluidic systems using reversibly attached PDMS fluid control modules

    DEFF Research Database (Denmark)

    Skafte-Pedersen, Peder; Sip, Christopher G.; Folch, Albert


    alternatives to integration because they can be tailored for different applications piecewise and without redesigning every element of the system. We present a method for reversibly coupling hard materials to soft lithography defined systems through self-aligning O-ring features thereby enabling easy...... interfacing of complex-valve-based systems with simpler detachable units. Using this scheme, we demonstrate the seamless interfacing of a PDMS-based fluid control module with hard polymer chips. In our system, 32 self-aligning O-ring features protruding from the PDMS fluid control module form chip......-to-control module interconnections which are sealed by tightening four screws. The interconnection method is robust and supports complex fluidic operations in the reversibly attached passive chip. In addition, we developed a double-sided molding method for fabricating PDMS devices with integrated through...

  9. Adaptation of systems to fluid changes; Adaptation des systemes aux changements de fluides

    Energy Technology Data Exchange (ETDEWEB)

    Clodic, D. [Ecole Nationale Superieure des Mines, 75 - Paris (France)


    Regulation constraints and the stoppage of CFCs production and HCFCs production in the future lead to rapid evolutions in the conceiving of refrigerating installations which are linked with refrigerant changes. The refrigerant/installation pair has become the aim of detailed analyses in order to understand the relation between the thermodynamical properties of fluids and the energy efficiency of refrigerating installations. The efficiency depends entirely on the global design of the installation while the choice of the fluid is only one element that contributes to this efficiency. This paper analyzes successively: the consequences of pure refrigerant substitution on volume and centrifugal compressors, and the constraints linked with the use of mixtures close to azeotropic compounds (R408A and R404A) and mixtures with temperature shift like R407C. In this last case, the replacement is deeply different in the case of water heat exchangers and in the case of air-circulation heat exchangers. (J.S.) 3 refs.

  10. Random-lattice models and simulation algorithms for the phase equilibria in two-dimensional condensed systems of particles with coupled internal and translational degrees of freedom

    DEFF Research Database (Denmark)

    Nielsen, Morten; Miao, Ling; Ipsen, John Hjorth


    In this work we concentrate on phase equilibria in two-dimensional condensed systems of particles where both translational and internal degrees of freedom are present and coupled through microscopic interactions, with a focus on the manner of the macroscopic coupling between the two types...... spin-spin interactions that may have spatial dependence. The fluctuating number of nearest neighbors and the possible spatial dependence of the spin-spin interactions couple microscopically the spin degrees of freedom to the translational degrees of freedom. The first model (I) is a random......-disorder singularity can be of first order throughout the phase diagram. It is found that this first-order singularity can be either coupled to or decoupled from the lattice-melting singularity, depending on the strength of the microscopic coupling. The calculated phase diagram and the associated thermodynamic...

  11. A comparative analysis of modal motions for the gyroscopic and non-gyroscopic two degree-of-freedom conservative systems (United States)

    Yang, Xiao-Dong; An, Hua-Zhen; Qian, Ying-Jing; Zhang, Wei; Melnik, Roderick V. N.


    The synchronous in-unison motions in vibrational mechanics and the non-synchronous out-of-unison motions are the most frequently found periodic motions in every fields of science and everywhere in the universe. In contrast to the in-unison normal modes, the out-of-unison complex modes feature a π/2 phase difference. By the complex mode analysis we classify the out-of-unison planar motion into two types, gyroscopic motions and elliptic motions. It is found that the gyroscopic and elliptic motions have different characteristics for a two degree-of-freedom (2DOF) system. The gyroscopic motion involves two distinct frequencies with, respectively, two corresponding complex modes. However, the elliptic motion the nonlinear non-gyroscopic 2DOF system with repeated frequencies involves only single frequency with corresponding two complex modes. The study of the differences and similarities of the gyroscopic and elliptic modes sheds new light on the in-depth mechanism of the planar motions in the universe and the man-made engineering systems.

  12. Analytical determination of bifurcations of periodic solution in three-degree-of-freedom vibro-impact systems with clearance

    International Nuclear Information System (INIS)

    Liu, Yongbao; Wang, Qiang; Xu, Huidong


    The smooth bifurcation and non-smooth grazing bifurcation of periodic solution of three-degree-of-freedom vibro-impact systems with clearance are studied in this paper. Firstly, six-dimensional Poincaré maps are established through choosing suitable Poincaré section and solving periodic solutions of vibro-impact system. Then, as the analytic expressions of all eigenvalues of Jacobi matrix of six-dimensional map are unavailable, the numerical calculations to search for the critical bifurcation values point by point is a laborious job based on the classical critical criterion described by the properties of eigenvalues. To overcome the difficulty from the classical bifurcation criteria, the explicit critical criterion without using eigenvalues calculation of high-dimensional map is applied to determine bifurcation points of Co-dimension-one bifurcations and Co-dimension-two bifurcations, and then local dynamical behaviors of these bifurcations are further analyzed. Finally, the existence of the grazing periodic solution of the vibro-impact system and grazing bifurcation point are analyzed, the discontinuous grazing bifurcation behavior is studied based on the compound normal form map near the grazing point, the discontinuous jumping phenomenon and the co-existing multiple solutions near the grazing bifurcation point are revealed.

  13. A gun recoil system employing a magnetorheological fluid damper (United States)

    Li, Z. C.; Wang, J.


    This research aims to design and control a full scale gun recoil buffering system which works under real firing impact loading conditions. A conventional gun recoil absorber is replaced with a controllable magnetorheological (MR) fluid damper. Through dynamic analysis of the gun recoil system, a theoretical model for optimal design and control of the MR fluid damper for impact loadings is derived. The optimal displacement, velocity and optimal design rules are obtained. By applying the optimal design theory to protect against impact loadings, an MR fluid damper for a full scale gun recoil system is designed and manufactured. An experimental study is carried out on a firing test rig which consists of a 30 mm caliber, multi-action automatic gun with an MR damper mounted to the fixed base through a sliding guide. Experimental buffering results under passive control and optimal control are obtained. By comparison, optimal control is better than passive control, because it produces smaller variation in the recoil force while achieving less displacement of the recoil body. The optimal control strategy presented in this paper is open-loop with no feedback system needed. This means that the control process is sensor-free. This is a great benefit for a buffering system under impact loading, especially for a gun recoil system which usually works in a harsh environment.

  14. A gun recoil system employing a magnetorheological fluid damper

    International Nuclear Information System (INIS)

    Li, Z C; Wang, J


    This research aims to design and control a full scale gun recoil buffering system which works under real firing impact loading conditions. A conventional gun recoil absorber is replaced with a controllable magnetorheological (MR) fluid damper. Through dynamic analysis of the gun recoil system, a theoretical model for optimal design and control of the MR fluid damper for impact loadings is derived. The optimal displacement, velocity and optimal design rules are obtained. By applying the optimal design theory to protect against impact loadings, an MR fluid damper for a full scale gun recoil system is designed and manufactured. An experimental study is carried out on a firing test rig which consists of a 30 mm caliber, multi-action automatic gun with an MR damper mounted to the fixed base through a sliding guide. Experimental buffering results under passive control and optimal control are obtained. By comparison, optimal control is better than passive control, because it produces smaller variation in the recoil force while achieving less displacement of the recoil body. The optimal control strategy presented in this paper is open-loop with no feedback system needed. This means that the control process is sensor-free. This is a great benefit for a buffering system under impact loading, especially for a gun recoil system which usually works in a harsh environment. (paper)

  15. Contextual freedom: absoluteness versus relativity of freedom. (United States)

    Pahlavan, Farzaneh; Amirrezvani, Ali


    Our commentary is focused on the idea that "freedom" takes on its full significance whenever its relativistic nature, in the short- and long terms, is taken into account. Given the transformations brought about by "globalization," application of a general model of freedom based on ecological-economic factors clearly seems to be rather untimely. We examine this idea through egocentric and ethnocentric views of the social and environmental analyses of "freedom."


    Directory of Open Access Journals (Sweden)

    Simon Schleiter


    Full Text Available The determination of dynamic parameters are the central points of the system identification of civil engineering structures under dynamic loading. This paper first gives a brief summary of the recent developments of the system identification methods in civil engineering and describes mathematical models, which enable the identification of the necessary parameters using only stochastic input signals. Relevant methods for this identification use Frequency Domain Decomposition (FDD, Autoregressive Moving Average Models (ARMA and the Autoregressive Models with eXogenous input (ARX. In a first step an elasto-mechanical mdof-system is numerically modeled using FEM and afterwards tested numerically by above mentioned identification methods using stochastic signals. During the second campaign, dynamic measurements are conducted experimentally on a real 7-story RC-building with ambient signal input using sensors. The results are successfully for the relevant system identification methods.

  17. Reviewing fluid systems for age-related degradation

    International Nuclear Information System (INIS)

    Smith, Stan


    Yankee Atomic Electric Company has developed the component degradation assessment tool (CoDAT), an expert system, that aids in handling and evaluating the large amounts of data required to support the license renewal process for nuclear power station fluid systems. In 1990, CoDAT evaluated the Yankee Nuclear Power Station fluid systems for age-related degradation. Its results are now being used to help focus the plant's maintenance programs and manage the expected degradation. CoDAT uses 'If-Then' rules, developed from industry codes, standards and publications, to determine the potential for 19 age-related degradation mechanisms. Other nuclear utilities pursuing the license renewal option also could use CoDAT. (author)

  18. Multistability of a three-degree-of-freedom vibro-impact system (United States)

    Zhang, Yongxiang; Luo, Guanwei


    Four types of scenarios occurring multistability are identified in a vibro-impact system. Besides the coexistence of high-periodic attractors and chaotic attractors, this system has some coexisting multi-frequency quasiperiodical attractors. We observe the coexistence of different two-dimensional tori T2, which the mechanism of torus formation involves phase-locked dynamics on three-dimensional tori. We also find that the tori T3 and the tori T2 (or period-3) coexist for a certain set of parameters. The mechanism leading to the multistability is investigated through interplay among the codimension two bifurcations, strong resonance bifurcations and global bifurcations.

  19. Error Analysis of Statistical Linearization with Gaussian Closure for Large Degree-of-Freedom Systems

    DEFF Research Database (Denmark)

    Micaletti, R. C.; Cakmak, A. S.; Nielsen, Søren R. K.

    is the variance of the top-story displacement. The MDOF systems under consideration obtain their nonlinearity through cubic polynomial interstory restoring forces and the external excitation is modelled as the stationary output of a Kanai-Tajimi filter (which itself is excited by Gaussian white noise). Parameters...... of the filter and the MDOF structures, as well as the intensity of the Gaussian white noise, are calibrated such that quantitative comparisons of the error between the exact solutions, estimated from Monte Carlo simulations, and the ELS solutions are possible among systems of different dimensions....

  20. Non-integrability of first order resonances in Hamiltonian systems in three degrees of freedom (United States)

    Christov, Ognyan


    The normal forms of the Hamiltonian 1:2: ω resonances to degree three for ω = 1, 3, 4 are studied for integrability. We prove that these systems are non-integrable except for the discrete values of the parameters which are well known. We use the Ziglin-Morales-Ramis method based on the differential Galois theory.

  1. Real Time Filtering and Parameter Estimation for Dynamical Systems With Many Degrees of Freedom (United States)


    Forms for Reduced Stochastic Climate Models," PNAS, March 2009, Vol. 16, no. 10, pp. 3649-3653 (with R. Abramov ,) "New Algorithms for Low Frequency...Equatorial Shallow-Water Dynamics," CPAM, Vol. LXI, March 2008, pp. 0002 - 0012 (with R. Abramov ,) "New Approximations and Tests of Linear Fluctuation...Response for Chaotic Nonlinear Forced-Dissipative Dynamical Systems," J. Nonlinear Sci., Vol 18, pp. 303-341,2008 (with R. Abramov ,) "Blended Response

  2. A study of displacement-based fluid finite elements for calculating frequencies of fluid and fluid-structure systems

    International Nuclear Information System (INIS)

    Olson, L.G.; Bathe, K.J.


    The widely-used displacement-based finite element formulation for inviscid, compressible, small displacement fluid motions is examined, with the specific objective of calculating fluid-structure frequencies. It is shown that the formulation can be employed with confidence to predict the static response of fluids. Also the resonant frequencies of fluids in rigid cavities and the frequencies of fluids in flexible boundaries are solved successfully if a penalty on rotations is included in the formulation. However, the reason for writing this paper is that problems involving structures moving through fluids that behave almost incompressibly - such as an ellipse vibrating on a spring in water - could not be solved satisfactorily, for which a general explanation is given. (orig.)

  3. Thermal convection of a viscoelastic fluid in a fluid-porous system subjected to a horizontal plane Couette flow

    International Nuclear Information System (INIS)

    Yin, Chen; Niu, Jun; Fu, Ceji; Tan, Wenchang


    Highlights: • Thermal convection in a two-layer system with viscoelastic fluids is studied firstly. • Transverse mode due to Couette flow is studied as well as longitudinal one for viscoelastic fluids. • The transverse mode may be the preferred mode in the case of viscoelastic fluids. -- Abstract: Thermal convection in superposed fluid and porous layers saturated with viscoelastic fluids subjected to a horizontal plane Couette flow is investigated. Transverse mode generated by the shear flow, whose axis of convection roll is normal to the base flow, is studied as well as longitudinal mode whose axis is parallel to the base flow. Numerical results show that the neutral curves of both modes are bimodal when the depth ratio of the fluid layer to the porous layer is proper. We found that longitudinal mode is influenced by the depth ratio only. However, the neutral curves of transverse mode change with the variations of the depth ratio, the Reynolds number, the Prandtl number, the stress relaxation time and the strain retardation time. It is also found that the increase of the depth ratio leads to a more unstable system, while the increases of Reynolds number and Prandtl number make the system more stable. Meanwhile, the system is more unstable with a larger stress relaxation time and a smaller stain retardation time. Our results show that for viscoelastic fluids the transverse mode can be the preferred mode with proper values of the parameters, which will never happen in the case of Newtonian fluids

  4. Heat transfer and fluid flow in nuclear systems

    CERN Document Server

    Fenech, Henri


    Heat Transfer and Fluid in Flow Nuclear Systems discusses topics that bridge the gap between the fundamental principles and the designed practices. The book is comprised of six chapters that cover analysis of the predicting thermal-hydraulics performance of large nuclear reactors and associated heat-exchangers or steam generators of various nuclear systems. Chapter 1 tackles the general considerations on thermal design and performance requirements of nuclear reactor cores. The second chapter deals with pressurized subcooled light water systems, and the third chapter covers boiling water reacto

  5. Analysis of Direct Samples of Early Solar System Aqueous Fluids (United States)

    Zolensky, Michael E.; Bodnar, R J.; Fedele, L.; Yurimoto,H.; Itoh, S.; Fries, M.; Steele, A.


    Over the past three decades we have become increasingly aware of the fundamental importance of water, and aqueous alteration, on primitive solar-system bodies. Some carbonaceous and ordinary chondrites have been altered by interactions with liquid water within the first 10 million years after formation of their parent asteroids. Millimeter to centimeter-sized aggregates of purple halite containing aqueous fluid inclusions were found in the matrix of two freshly-fallen brecciated H chondrite falls, Monahans (1998, hereafter simply "Monahans") (H5) and Zag (H3-6) (Zolensky et al., 1999; Whitby et al., 2000; Bogard et al., 2001) In order to understand origin and evolution of the aqueous fluids inside these inclusions we much measure the actual fluid composition, and also learn the O and H isotopic composition of the water. It has taken a decade for laboratory analytical techniques to catch up to these particular nanomole-sized aqueous samples. We have recently been successful in (1) measuring the isotopic composition of H and O in the water in a few fluid inclusions from the Zag and Monahans halite, (2) mineralogical characterization of the solid mineral phases associated with the aqueous fluids within the halite, and (3) the first minor element analyses of the fluid itself. A Cameca ims-1270 equipped with a cryo-sample-stage of Hokkaido University was specially prepared for the O and H isotopic measurements. The cryo-sample-stage (Techno. I. S. Corp.) was cooled down to c.a. -190 C using liquid nitrogen at which the aqueous fluid in inclusions was frozen. We excavated the salt crystal surfaces to expose the frozen fluids using a 15 keV Cs+ beam and measured negative secondary ions. The secondary ions from deep craters of approximately 10 m in depth emitted stably but the intensities changed gradually during measurement cycles because of shifting states of charge compensation, resulting in rather poor reproducibility of multiple measurements of standard fluid

  6. Interpretation of Fermion system equilibration by energy fluid motion

    International Nuclear Information System (INIS)

    Jang, S.


    We study the equilibration of fermion system with the help of both linear and non-linear master equations which are originated from the extended time-dependent Hartree-Fock equation of motion. We show how the non-linear master equation for nucleon occupation number transforms into the Navier-Stokes type of one dimensional equation for non-stationary flow of a compressible and viscous fluid. Physical consequences of these equations are investigated by providing illustrative examples

  7. INIS - International Nuclear Information System. CEA-users relations. Nuclear information in total freedom

    International Nuclear Information System (INIS)

    Surmont, J.; Paillard, M.D.; Constant, A.; Guille, N.; Le Blanc, A.; Mouffron, O.; Anguise, P.; Jouve, J.J.; Lilin, A.


    This poster, prepared for the seventh edition of the meetings of scientific and technical information professionals (RPIST, Nancy (France)), presents the principle of operation of the INIS system, based on a cooperative and decentralized preparation of the data which are centralized by the IAEA for the preparation of the INIS products: the database (on Internet and on CD/DVD-Rom), the collection of grey literature documents in full text (microfiches and CD/DVD-roms), and the multilingual thesaurus available in 7 different languages and under various formats. The poster presents these different products, and the role of the INIS members in the distribution of these products towards their national users. One insert presents the French INIS team of the CEA-Saclay and its daily work. (J.S.)

  8. State Space System Identification of 3-Degree-of-Freedom (DOF Piezo-Actuator-Driven Stages with Unknown Configuration

    Directory of Open Access Journals (Sweden)

    Yu Cao


    Full Text Available Due to their fast response, high accuracy and non-friction force, piezo-actuators have been widely employed in multiple degree-of-freedom (DOF stages for various nano-positioning applications. The use of flexible hinges in these piezo-actuator-driven stages allows the elimination of the influence of friction and backlash clearance, as observed in other configurations; meanwhile it also causes more complicated stage performance in terms of dynamics and the cross-coupling effect between different axes. Based on the system identification technique, this paper presents the development of a model for the 3-DOF piezo-actuator-driven stages with unknown configuration, with its parameters estimated from the Hankel matrix by means of the maximum a posteriori (MAP online estimation. Experiments were carried out on a commercially-available piezo-actuator-driven stage to verify the effectiveness of the developed model, as compared to other methods. The results show that the developed model is able to predict the stage performance with improved accuracy, while the model parameters can be well updated online by using the MAP estimation. These capabilities allow investigation of the complicated stage performance and also provide a starting point from which the mode-based control scheme can be established for improved performance.

  9. Five-degrees-of-freedom measurement system based on a monolithic prism and phase-sensitive detection technique. (United States)

    Huang, Pei; Li, Yan; Wei, Haoyun; Ren, Libing; Zhao, Shijie


    This paper presents a method for measuring five-degrees-of-freedom errors of a moving stage with a monolithic prism and phase-sensitive detection technique. It consists of a pigtailed laser diode, three position-sensitive detectors (PSDs), a monolithic prism, and additional optical and electronic components. The monolithic prism mounted on the moving stage generates three beams that are detected by three PSDs, respectively, so that the straightness, pitch, yaw, and roll errors can be simultaneously measured. Theoretical analysis of each error measurement process is presented. To reduce the influence of disturbing light, the laser diode is modulated by a sinusoidal wave current, and a phase-sensitive detection technique is developed to demodulate the signals. Compared with a laser interferometer, the deviation errors when measuring the horizontal and vertical straightness errors are better than ±0.25 and ±0.4 μm, respectively. The deviation errors for the pitch, yaw, and roll are better than ±0.5, ±0.3, and ±2 arc sec, respectively, in comparison with an autocollimator. The system can be assembled to measure five error components of machine tools in an industrial environment.

  10. 21 CFR 882.5550 - Central nervous system fluid shunt and components. (United States)


    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Central nervous system fluid shunt and components... Central nervous system fluid shunt and components. (a) Identification. A central nervous system fluid... central nervous system to an internal delivery site or an external receptacle for the purpose of relieving...

  11. Network Flow Simulation of Fluid Transients in Rocket Propulsion Systems (United States)

    Bandyopadhyay, Alak; Hamill, Brian; Ramachandran, Narayanan; Majumdar, Alok


    Fluid transients, also known as water hammer, can have a significant impact on the design and operation of both spacecraft and launch vehicle propulsion systems. These transients often occur at system activation and shutdown. The pressure rise due to sudden opening and closing of valves of propulsion feed lines can cause serious damage during activation and shutdown of propulsion systems. During activation (valve opening) and shutdown (valve closing), pressure surges must be predicted accurately to ensure structural integrity of the propulsion system fluid network. In the current work, a network flow simulation software (Generalized Fluid System Simulation Program) based on Finite Volume Method has been used to predict the pressure surges in the feed line due to both valve closing and valve opening using two separate geometrical configurations. The valve opening pressure surge results are compared with experimental data available in the literature and the numerical results compared very well within reasonable accuracy (< 5%) for a wide range of inlet-to-initial pressure ratios. A Fast Fourier Transform is preformed on the pressure oscillations to predict the various modal frequencies of the pressure wave. The shutdown problem, i.e. valve closing problem, the simulation results are compared with the results of Method of Characteristics. Most rocket engines experience a longitudinal acceleration, known as "pogo" during the later stage of engine burn. In the shutdown example problem, an accumulator has been used in the feed system to demonstrate the "pogo" mitigation effects in the feed system of propellant. The simulation results using GFSSP compared very well with the results of Method of Characteristics.

  12. Computational Fluid Dynamics Analysis of an Evaporative Cooling System

    Directory of Open Access Journals (Sweden)

    Kapilan N.


    Full Text Available The use of chlorofluorocarbon based refrigerants in the air-conditioning system increases the global warming and causes the climate change. The climate change is expected to present a number of challenges for the built environment and an evaporative cooling system is one of the simplest and environmentally friendly cooling system. The evaporative cooling system is most widely used in summer and in rural and urban areas of India for human comfort. In evaporative cooling system, the addition of water into air reduces the temperature of the air as the energy needed to evaporate the water is taken from the air. Computational fluid dynamics is a numerical analysis and was used to analyse the evaporative cooling system. The CFD results are matches with the experimental results.

  13. Liquid Cooling System for CPU by Electroconjugate Fluid

    Directory of Open Access Journals (Sweden)

    Yasuo Sakurai


    Full Text Available The dissipated power of CPU for personal computer has been increased because the performance of personal computer becomes higher. Therefore, a liquid cooling system has been employed in some personal computers in order to improve their cooling performance. Electroconjugate fluid (ECF is one of the functional fluids. ECF has a remarkable property that a strong jet flow is generated between electrodes when a high voltage is applied to ECF through the electrodes. By using this strong jet flow, an ECF-pump with simple structure, no sliding portion, no noise, and no vibration seems to be able to be developed. And then, by the use of the ECF-pump, a new liquid cooling system by ECF seems to be realized. In this study, to realize this system, an ECF-pump is proposed and fabricated to investigate the basic characteristics of the ECF-pump experimentally. Next, by utilizing the ECF-pump, a model of a liquid cooling system by ECF is manufactured and some experiments are carried out to investigate the performance of this system. As a result, by using this system, the temperature of heat source of 50 W is kept at 60°C or less. In general, CPU is usually used at this temperature or less.

  14. A SDHW system with two-phase heat transfer fluid

    International Nuclear Information System (INIS)

    Konstantinou, K.; Belessiotis, V.; Hristoforou, A.


    Full text: This report examines the thermal performance of a SDHW system which uses ethanol 100% pure as heat transfer medium to the water in the tank. The energy transfer takes place through a change of phase of ethanol from liquid to vapor effected by the processes of boiling and condensation. A complete heat transfer analysis is performed, focused on the mechanisms of boiling and condensation. This method serves as a basic technique for the thermal evaluation of systems using two-phase fluids. (author)

  15. Instabilities of a spatial system of articulated pipes conveying fluid (United States)

    Bohn, M. P.; Herrmann, G.


    A spatial system of two articulated pipes conveying fluid is examined analytically and experimentally. As the flow rate is increased, stable equilibrium may be lost by either divergence (static buckling) or by flutter (oscillations with increasing amplitude), depending upon the value of an angle beta which measures the 'out-of-planeness' of the system. It is found that in the range O less than beta less than 90 deg there exists a transition value below which stability is lost by flutter and above which stability is lost by divergence.

  16. Freedom and Happiness

    NARCIS (Netherlands)

    R. Veenhoven (Ruut)


    textabstractFreedom in nations can affect the happiness of citizens both positively and negatively. This study takes stock of the balance of effects. It considers 1) whether there is a positive net-effect at all, 2) which freedom variants contribute most to happiness 3) in what conditions. Freedom

  17. Freedom, structure, and creativity

    NARCIS (Netherlands)

    Rietzschel, Eric; Reiter-Palmon, Roni; Kaufman, James


    Creativity is commonly thought to depend on freedom and a lack of constraints. While this is true to a large extent, it neglects the creative potential of structure and constraints. In this chapter, I will address the relation between freedom, structure, and creativity. I will explain that freedom,

  18. An intelligent data acquisition system for fluid mechanics research (United States)

    Cantwell, E. R.; Zilliac, G.; Fukunishi, Y.


    This paper describes a novel data acquisition system for use with wind-tunnel probe-based measurements, which incorporates a degree of specific fluid dynamics knowledge into a simple expert system-like control program. The concept was developed with a rudimentary expert system coupled to a probe positioning mechanism operating in a small-scale research wind tunnel. The software consisted of two basic elements, a general-purpose data acquisition system and the rulebased control element to take and analyze data and supplying decisions as to where to measure, how many data points to take, and when to stop. The system was validated in an experiment involving a vortical flow field, showing that it was possible to increase the resolution of the experiment or, alternatively, reduce the total number of data points required, to achieve parity with the results of most conventional data acquisition approaches.

  19. Freedom of Expression, Right to Information, Personal Data and the Internet in the view of the Inter-American System of Human Rights

    Directory of Open Access Journals (Sweden)

    Silvia Susana TOSCANO


    Full Text Available The Inter-American System of Protection of Human Rights is composed of microsystems, like the freedom of expression, the right to information and the protection of privacy and of personal data, among others. These rights interrelate and form the standards of the Inter-American system, in accordance with the UN system, to develop these liberties, and to keep the constant balance of these rights in conflict. All of this enhanced by a dynamic and growing massiveness, like the internet and by a new paradigm in which the freedom of expression and the right to information is included: a postmodern society characterized by a “democratization” of connectivity, a multidirectional transmission of the information and a dichotomy between what is public or private. Freedom of expression is developed in both of its two dimensions: individual or collective. When we talk about its individual dimension, we mean the right of each person to express his ideas, thoughts and beliefs aiming at unidirectional, bidirectional or multidirectional communication. The collective or social dimension refers to the right of a person to receive any type of information, to know the thoughts, ideas and information of others and have free access to them. Both dimensions are equally important and are interdependent, thus it is important to protect them simultaneously. New communication technologies have altered the previous system, and the individual dimension of freedom of expression breaks into public debate on the democratization of internet access and its social dimension due to the feasibility a multidirectional communication impossible to conceive in any other technological paradigm entails. The protection scheme of freedom of expression of the Inter-American System is particularly strong as it specifically prohibits prior censorship and rules sanctions and very strict restrictions in relation to discrimination, advocacy of war, violence and hatred. This characteristic

  20. Modeling interfacial area transport in multi-fluid systems

    Energy Technology Data Exchange (ETDEWEB)

    Yarbro, Stephen Lee [Univ. of California, Berkeley, CA (United States)


    Many typical chemical engineering operations are multi-fluid systems. They are carried out in distillation columns (vapor/liquid), liquid-liquid contactors (liquid/liquid) and other similar devices. An important parameter is interfacial area concentration, which determines the rate of interfluid heat, mass and momentum transfer and ultimately, the overall performance of the equipment. In many cases, the models for determining interfacial area concentration are empirical and can only describe the cases for which there is experimental data. In an effort to understand multiphase reactors and the mixing process better, a multi-fluid model has been developed as part of a research effort to calculate interfacial area transport in several different types of in-line static mixers. For this work, the ensemble-averaged property conservation equations have been derived for each fluid and for the mixture. These equations were then combined to derive a transport equation for the interfacial area concentration. The final, one-dimensional model was compared to interfacial area concentration data from two sizes of Kenics in-line mixer, two sizes of concurrent jet and a Tee mixer. In all cases, the calculated and experimental data compared well with the highest scatter being with the Tee mixer comparison.

  1. Conceptual design of intravenous fluids level monitoring system - a review (United States)

    Verma, Prikshit; Padmani, Aniket; Boopathi, M.


    In today’s world of automation, there are advancements going on in all the fields. Each work is being automated day by day. However, if we see our current medical care system, some areas require manual caretaker and are loaded with heavy jobs, which consumes a lot of time. Nevertheless, since the work is related to human health, it should be properly done and that too with accuracy. An example of such a particular work is injecting saline or Intravenous (IV) fluids in a patient. The monitoring of such fluids needs utter attention as if the bottle of the fluid is not changed on time, it may lead to various problems for the patients like backflow of blood, blood loss etc. Various researches have been performed to overcome such critical situation. Different monitoring and alerting techniques are described in different researches. So, in our study, we will go through the researches done in this particular field and will see how different ideas are implemented.

  2. Advanced computational method for studying molecular vibrations and spectra for symmetrical systems with many degrees of freedom, and its application to fullerene (United States)

    Bogush, Igor; Ciobu, Victor; Paladi, Florentin


    A computational method for studying molecular vibrations and spectra for symmetrical systems with many degrees of freedom was developed. The algorithm allows overcoming difficulties on the automation of calculus related to the symmetry determination of such oscillations in complex systems with many degrees of freedom. One can find symmetrized displacements and, consequently, obtain and classify normal oscillations and their frequencies. The problem is therefore reduced to the determination of eigenvectors by common numerical methods, and the algorithm simplifies the procedure of symmetry determination for normal oscillations. The proposed method was applied to studying molecular vibrations and spectra of the fullerene molecule C60, and the comparison of theoretical results with experimental data is drawn. The computational method can be further extended to other problems of group theory in physics with applications in clusters and nanostructured materials.

  3. Design Considerations for Artificial Lifting of Enhanced Geothermal System Fluids

    Energy Technology Data Exchange (ETDEWEB)

    Xina Xie; K. K. Bloomfield; G. L. Mines; G. M. Shook


    This work evaluates the effect of production well pumping requirements on power generation. The amount of work that can be extracted from a geothermal fluid and the rate at which this work is converted to power increase as the reservoir temperature increases. Artificial lifting is an important issue in this process. The results presented are based on a configuration comprising one production well and one injection well, representing an enhanced geothermal system. The effects of the hydraulic conductivity of the geothermal reservoir, the flow rate, and the size of the production casing are considered in the study. Besides submersible pumps, the possibility of using lineshaft pumps is also discussed.

  4. Computational transport phenomena of fluid-particle systems

    CERN Document Server

    Arastoopour, Hamid; Abbasi, Emad


    This book concerns the most up-to-date advances in computational transport phenomena (CTP), an emerging tool for the design of gas-solid processes such as fluidized bed systems. The authors examine recent work in kinetic theory and CTP and illustrate gas-solid processes’ many applications in the energy, chemical, pharmaceutical, and food industries. They also discuss the kinetic theory approach in developing constitutive equations for gas-solid flow systems and how it has advanced over the last decade as well as the possibility of obtaining innovative designs for multiphase reactors, such as those needed to capture CO2 from flue gases. Suitable as a concise reference and a textbook supplement for graduate courses, Computational Transport Phenomena of Gas-Solid Systems is ideal for practitioners in industries involved with the design and operation of processes based on fluid/particle mixtures, such as the energy, chemicals, pharmaceuticals, and food processing. Explains how to couple the population balance e...

  5. Computational fluid dynamics (CFD) studies of a miniaturized dissolution system. (United States)

    Frenning, G; Ahnfelt, E; Sjögren, E; Lennernäs, H


    Dissolution testing is an important tool that has applications ranging from fundamental studies of drug-release mechanisms to quality control of the final product. The rate of release of the drug from the delivery system is known to be affected by hydrodynamics. In this study we used computational fluid dynamics to simulate and investigate the hydrodynamics in a novel miniaturized dissolution method for parenteral formulations. The dissolution method is based on a rotating disc system and uses a rotating sample reservoir which is separated from the remaining dissolution medium by a nylon screen. Sample reservoirs of two sizes were investigated (SR6 and SR8) and the hydrodynamic studies were performed at rotation rates of 100, 200 and 400rpm. The overall fluid flow was similar for all investigated cases, with a lateral upward spiraling motion and central downward motion in the form of a vortex to and through the screen. The simulations indicated that the exchange of dissolution medium between the sample reservoir and the remaining release medium was rapid for typical screens, for which almost complete mixing would be expected to occur within less than one minute at 400rpm. The local hydrodynamic conditions in the sample reservoirs depended on their size; SR8 appeared to be relatively more affected than SR6 by the resistance to liquid flow resulting from the screen. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. An ambient radioxenon monitoring system based on fluid transfer concentration (United States)

    Russ, William Robert, II

    A monitoring system using fluid transfer concentration has been developed to measure ambient radioxenon, an indicator of underground nuclear weapons testing. The monitoring system consists of a concentration system and detection system. Low concentrations of ambient radioxenon necessitate concentrating atmospheric xenon to enable detection of signature xenon radiation against normal background radiation. The concentration system relies on the preferential absorption of xenon in oil followed by the degassing of the fluid to produce an output containing a much greater fraction of xenon than the atmospheric input. The concentration system first absorbs ambient radioxenon then releases the radioxenon by degassing. A prototype packed bed absorption column was characterized. Columns of different dimensions and flow rates were modeled. Heating, ultrasound, bubbling, drawing a vacuum on the headspace above the oil and combinations thereof were evaluated as a means of degassing. An effective degassing technique was the combination of strong vacuum, cavitating agitation, and a packed bed. Various detectors and pulse processing techniques were evaluated. A combination of an electron detector and a photon detector was used to take advantage of the characteristic electron/photon coincidence radiation of radioxenon. A NaI(TI) scintillator was used as the photon detector, and a gas proportional detector, plastic scintillator and liquid scintillator were evaluated for use as the electron detector. Simple coincidence, coincidence with electron detector pulse height discrimination, coincidence with electron detector pulse shape discrimination, and delayed coincidence pulse processing techniques were evaluated as a means of minimizing background counts, especially from radon and radon progeny. The most promising detection systems were a gas proportional/NaI(TI) detector operated in coincidence mode using pulse height discrimination with the gas proportional detector, and a plastic

  7. Computational fluid dynamics applications to improve crop production systems (United States)

    Computational fluid dynamics (CFD), numerical analysis and simulation tools of fluid flow processes have emerged from the development stage and become nowadays a robust design tool. It is widely used to study various transport phenomena which involve fluid flow, heat and mass transfer, providing det...

  8. Dissipative finite degrees of freedom dynamical system and description of optical systems with saturable amplification, saturable losses and filtering (United States)

    Uzunov, Ivan M.


    Single-mode fiber optical system with saturable amplification, saturable losses and spectral filtering as proposed by Rozanov and Fedorov (1998) [10] is studied. The system of ordinary differential equations (ODE's) that can help investigation of the original physical system is proposed. It allows calculation of linear and nonlinear fixed points as well as the study of their stability, so it can be used for analysis of coherent structures and their classification. Derived system of ODE's extends the earlier one proposed by van Saarloos and Hohenberg (1992) [2], for the analysis of coherent structures of the qubic-quintic Ginzburg-Landau equation, by including additionally the temporal dependences of the gain and losses. In order to verify it, it was applied to the earlier considered cases of fast and slow changes in the amplification and losses. Earlier obtained localized structures namely pulses, have been observed via numerical solution of the proposed system. In addition, new families of fronts have been identified.

  9. Therapeutic Options for Controlling Fluids in the Visual System (United States)

    Curry, Kristina M.; Wotring, Virginia E.


    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.

  10. COTHERM: Modelling fluid-rock interactions in Icelandic geothermal systems (United States)

    Thien, Bruno; Kosakowski, Georg; Kulik, Dmitrii


    Mineralogical alteration of reservoir rocks, driven by fluid circulation in natural or enhanced geothermal systems, is likely to influence the long-term performance of geothermal power generation. A key factor is the change of porosity due to dissolution of primary minerals and precipitation of secondary phases. Porosity changes will affect fluid circulation and solute transport, which, in turn, influence mineralogical alteration. This study is part of the Sinergia COTHERM project (COmbined hydrological, geochemical and geophysical modeling of geotTHERMal systems) that is an integrative research project aimed at improving our understanding of the sub-surface processes in magmatically-driven natural geothermal systems. We model the mineralogical and porosity evolution of Icelandic geothermal systems with 1D and 2D reactive transport models. These geothermal systems are typically high enthalphy systems where a magmatic pluton is located at a few kilometers depth. The shallow plutons increase the geothermal gradient and trigger the circulation of hydrothermal waters with a steam cap forming at shallow depth. We investigate two contrasting geothermal systems: Krafla, for which the water recharge consists of meteoritic water; and Reykjanes, for which the water recharge mainly consists of seawater. The initial rock composition is a fresh basalt. We use the GEM-Selektor geochemical modeling package [1] for calculation of kinetically controlled mineral equilibria between the rock and the ingression water. We consider basalt minerals dissolution kinetics according to Palandri & Kharaka [2]. Reactive surface areas are assumed to be geometric surface areas, and are corrected using a spherical-particle surface/mass relationship. For secondary minerals, we consider the partial equilibrium assuming that the primary mineral dissolution is slow, and the secondary mineral precipitation is fast. Comparison of our modeling results with the mineralogical assemblages observed in the

  11. Safety System for Controlling Fluid Flow into a Suction Line (United States)

    England, John Dwight (Inventor); Kelley, Anthony R. (Inventor); Cronise, Raymond J. (Inventor)


    A safety system includes a sleeve fitted within a pool's suction line at the inlet thereof. An open end of the sleeve is approximately aligned with the suction line's inlet. The sleeve terminates with a plate that resides within the suction line. The plate has holes formed therethrough. A housing defining a plurality of distinct channels is fitted in the sleeve so that the distinct channels lie within the sleeve. Each of the distinct channels has a first opening on one end thereof and a second opening on another end thereof. The second openings reside in the sleeve. Each of the distinct channels is at least approximately three feet in length. The first openings are in fluid communication with the water in the pool, and are distributed around a periphery of an area of the housing that prevents coverage of all the first openings when a human interacts therewith.

  12. Safety System for Controlling Fluid Flow into a Suction Line (United States)

    England, John Dwight (Inventor); Kelley, Anthony R. (Inventor); Cronise, Raymond J. (Inventor)


    A safety system includes a sleeve fitted within a pool's suction line at its inlet. The sleeve terminates with a plate that resides within the suction line. The plate has holes formed therethrough. A housing defining distinct channels is fitted in the sleeve so that the distinct channels lie within the sleeve. Each of the distinct channels has a first opening on one end thereof and a second opening on another end thereof. The second openings reside in the sleeve. The first openings are in fluid communication with the water in the pool, and are distributed around a periphery of an area of the housing that prevents coverage of all the first openings when a human interacts therewith. A first sensor is coupled to the sleeve to sense pressure therein, and a second pressure sensor is coupled to the plate to sense pressure in one of the plates' holes.

  13. Characterization of Fluid Flow in Paper-Based Microfluidic Systems (United States)

    Walji, Noosheen; MacDonald, Brendan


    Paper-based microfluidic devices have been presented as a viable low-cost alternative with the versatility to accommodate many applications in disease diagnosis and environmental monitoring. Current microfluidic designs focus on the use of silicone and PDMS structures, and several models have been developed to describe these systems; however, the design process for paper-based devices is hindered by a lack of prediction capability. In this work we simplify the complex underlying physics of the capillary-driven flow mechanism in a porous medium and generate a practical numerical model capable of predicting the flow behaviour. We present our key insights regarding the properties that dictate the behaviour of fluid wicking in paper-based microfluidic devices. We compare the results from our model to experiments and discuss the application of our model to design of paper-based microfluidic devices for arsenic detection in drinking water in Bangladesh.

  14. Freedom & Self-Knowledge

    NARCIS (Netherlands)

    Ometto, D.L.A.


    Freedom of the will is a never-ending source of puzzlement for academic philosophers. At the same time, it is something deeply familiar to everyone. For the relevant concept of freedom underlies much, if not all, of our ordinary discourse and thinking about ourselves and others. However, our attempt

  15. Hamiltonian description of the ideal fluid

    Energy Technology Data Exchange (ETDEWEB)

    Morrison, P.J.


    Fluid mechanics is examined from a Hamiltonian perspective. The Hamiltonian point of view provides a unifying framework; by understanding the Hamiltonian perspective, one knows in advance (within bounds) what answers to expect and what kinds of procedures can be performed. The material is organized into five lectures, on the following topics: rudiments of few-degree-of-freedom Hamiltonian systems illustrated by passive advection in two-dimensional fluids; functional differentiation, two action principles of mechanics, and the action principle and canonical Hamiltonian description of the ideal fluid; noncanonical Hamiltonian dynamics with examples; tutorial on Lie groups and algebras, reduction-realization, and Clebsch variables; and stability and Hamiltonian systems.

  16. Computational fluid dynamics for turbomachinery internal air systems. (United States)

    Chew, John W; Hills, Nicholas J


    Considerable progress in development and application of computational fluid dynamics (CFD) for aeroengine internal flow systems has been made in recent years. CFD is regularly used in industry for assessment of air systems, and the performance of CFD for basic axisymmetric rotor/rotor and stator/rotor disc cavities with radial throughflow is largely understood and documented. Incorporation of three-dimensional geometrical features and calculation of unsteady flows are becoming commonplace. Automation of CFD, coupling with thermal models of the solid components, and extension of CFD models to include both air system and main gas path flows are current areas of development. CFD is also being used as a research tool to investigate a number of flow phenomena that are not yet fully understood. These include buoyancy-affected flows in rotating cavities, rim seal flows and mixed air/oil flows. Large eddy simulation has shown considerable promise for the buoyancy-driven flows and its use for air system flows is expected to expand in the future.

  17. Method and apparatus for continuous fluid leak monitoring and detection in analytical instruments and instrument systems (United States)

    Weitz, Karl K [Pasco, WA; Moore, Ronald J [West Richland, WA


    A method and device are disclosed that provide for detection of fluid leaks in analytical instruments and instrument systems. The leak detection device includes a collection tube, a fluid absorbing material, and a circuit that electrically couples to an indicator device. When assembled, the leak detection device detects and monitors for fluid leaks, providing a preselected response in conjunction with the indicator device when contacted by a fluid.

  18. Mode-based equivalent multi-degree-of-freedom system for one-dimensional viscoelastic response analysis of layered soil deposit (United States)

    Li, Chong; Yuan, Juyun; Yu, Haitao; Yuan, Yong


    Discrete models such as the lumped parameter model and the finite element model are widely used in the solution of soil amplification of earthquakes. However, neither of the models will accurately estimate the natural frequencies of soil deposit, nor simulate a damping of frequency independence. This research develops a new discrete model for one-dimensional viscoelastic response analysis of layered soil deposit based on the mode equivalence method. The new discrete model is a one-dimensional equivalent multi-degree-of-freedom (MDOF) system characterized by a series of concentrated masses, springs and dashpots with a special configuration. The dynamic response of the equivalent MDOF system is analytically derived and the physical parameters are formulated in terms of modal properties. The equivalent MDOF system is verified through a comparison of amplification functions with the available theoretical solutions. The appropriate number of degrees of freedom (DOFs) in the equivalent MDOF system is estimated. A comparative study of the equivalent MDOF system with the existing discrete models is performed. It is shown that the proposed equivalent MDOF system can exactly present the natural frequencies and the hysteretic damping of soil deposits and provide more accurate results with fewer DOFs.

  19. A dynamic optical measurement system for cryogenic fluids using laser interferometry

    International Nuclear Information System (INIS)

    Zhang, J H; Bao, S R; Zhang, R P; Qiu, L M


    Dynamic visualization is of great significance in the research of flow conditions and mass transfer process of cryogenic fluids. In this paper, two common ways to measure the concentration of cryogenic fluids are introduced and compared. To improve the real-time monitoring of cryogenic fluid, a non-contact dynamic optical measurement system using laser interferometry is designed, which is sensitive to subtle changes of fluid concentration. A precise and dynamic interference pattern can be obtained using this system. Two-dimensional concentration distribution of the fluid can be calculated from the interference pattern. Detailed calculation process is presented in the paper. (paper)

  20. Theory and computation of non-RRKM lifetime distributions and rates in chemical systems with three or more degrees of freedom (United States)

    Gabern, Frederic; Koon, Wang S.; Marsden, Jerrold E.; Ross, Shane D.


    The computation, starting from basic principles, of chemical reaction rates in realistic systems (with three or more degrees of freedom) has been a longstanding goal of the chemistry community. Our current work, which merges tube dynamics with Monte Carlo methods provides some key theoretical and computational tools for achieving this goal. We use basic tools of dynamical systems theory, merging the ideas of Koon et al. [W.S. Koon, M.W. Lo, J.E. Marsden, S.D. Ross, Heteroclinic connections between periodic orbits and resonance transitions in celestial mechanics, Chaos 10 (2000) 427-469.] and De Leon et al. [N. De Leon, M.A. Mehta, R.Q. Topper, Cylindrical manifolds in phase space as mediators of chemical reaction dynamics and kinetics. I. Theory, J. Chem. Phys. 94 (1991) 8310-8328.], particularly the use of invariant manifold tubes that mediate the reaction, into a tool for the computation of lifetime distributions and rates of chemical reactions and scattering phenomena, even in systems that exhibit non-statistical behavior. Previously, the main problem with the application of tube dynamics has been with the computation of volumes in phase spaces of high dimension. The present work provides a starting point for overcoming this hurdle with some new ideas and implements them numerically. Specifically, an algorithm that uses tube dynamics to provide the initial bounding box for a Monte Carlo volume determination is used. The combination of a fine scale method for determining the phase space structure (invariant manifold theory) with statistical methods for volume computations (Monte Carlo) is the main contribution of this paper. The methodology is applied here to a three degree of freedom model problem and may be useful for higher degree of freedom systems as well.

  1. The search for and analysis of direct samples of early Solar System aqueous fluids. (United States)

    Zolensky, Michael E; Bodnar, Robert J; Yurimoto, Hisayoshi; Itoh, Shoichi; Fries, Marc; Steele, Andrew; Chan, Queenie H-S; Tsuchiyama, Akira; Kebukawa, Yoko; Ito, Motoo


    We describe the current state of the search for direct, surviving samples of early, inner Solar System fluids-fluid inclusions in meteorites. Meteoritic aqueous fluid inclusions are not rare, but they are very tiny and their characterization is at the state of the art for most analytical techniques. Meteoritic fluid inclusions offer us a unique opportunity to study early Solar System brines in the laboratory. Inclusion-by-inclusion analyses of the trapped fluids in carefully selected samples will, in the immediate future, provide us detailed information on the evolution of fluids as they interacted with anhydrous solid materials. Thus, real data can replace calculated fluid compositions in thermochemical calculations of the evolution of water and aqueous reactions in comets, asteroids, moons and the terrestrial planets.This article is part of the themed issue 'The origin, history and role of water in the evolution of the inner Solar System'. © 2017 The Author(s).

  2. A fluid dynamic study on recovery system of methane hydrate

    Energy Technology Data Exchange (ETDEWEB)

    Hamaguchi, Ryokichi; Nishimura, Yuki; Matsukuma, Yosuke; Minemoto, Masaki; Watabe, Masaharu; Okawa, Katsunori


    A development of Methane Hydrate (MH), which exist under the ocean floor, has been brought to public attention. But, the production technology has not been established yet. It is important to understand the decomposition phenomenon of MH for an investigation of the safety and the profitability of production systems. In this research, the decomposition rate of gas hydrate was measured by using HCFC141b hydrate for a substitute of MH. Also, the decomposition phenomenon was simulated by Lattice Gas Automaton method in order to establish the technique which analytically estimates decomposition rate. From the experimental results, the decomposition rate was expressed by the equation between Nusselt number and Reynolds number. Furthermore, the flow in the MH recovery pipe was simulated to investigate the economical efficiency of product system of MH. The flow calculation model was based on the one-dimensional unsteady compressible three fluid model and adopted CFD method. As a result, Methane gas generated from decomposition of MH affect the flow in the recovery pipe. And it is indicates that utilizing the methane gas generated from decomposition may reduce the power consumption of the product system of MH from the deep ocean floor. (Author)

  3. Ultra deep water minimum production riser system for heavy fluid

    Energy Technology Data Exchange (ETDEWEB)

    Saint-Marcoux, Jean-Francois; Wu, Mason [Acergy M.S. Ltd., London (United Kingdom)


    Understanding the intricacies of a reservoir is a lengthy process. Deep water reservoirs are often compartmented. The access to the various areas of production requires drilling from several locations. As each of these zones is being brought to production, additional riser facilities are required. Therefore, the concept of a standardized minimum production riser system that is capable of being installed phase after phase is appealing. The minimum functions required for oil production are two-looped production lines, and one or two injection lines, fitting with a riser system dedicated to an isolated oil field. Such a concept is presented in this paper. Acergy has designed, built and installed the large bundled Hybrid Riser Towers of Girassol and Greater Plutonio, and has further streamlined its design and construction methods. Such project requires not only the capacity to engineer the facilities but also to source the material, manage the fabrication in country and execute the complex operations. This requires project management capacities to be able to ensure consistent interfaces, maintain schedule and budget accordingly. The proposed ultra deep water Minimum Production System incorporates lessons learned from all aspects of the Greater Plutonio and Girassol projects to further enhance the ability to handle a wide range of water depths and well fluids (from low to high GOR), including elevated pressure and temperature. The proposed Minimum Production Hybrid Riser Tower (MPHRT) lends itself to be decommissioned and reused if cost-efficient for the field development. (author)

  4. Brake Fluid Compatibility Studies with Advanced Brake Systems (United States)


    wear tests of the brake fluids. 15. SUBJECT TERMS Brake Fluid, SAE J1703, MIL-PRF-46176, FTIR , elastomer, lubricity, BOCLE, HFRR...elastomer absorbs sufficient brake fluid causing it to swell, it increases the thickness causing the elastomer to squeeze against the moving or sliding...Brake (HPB) components were identified using FTIR . The identity of the Parking Brake Supply and Relay Valve Seal remains unclear due to proprietary

  5. Declaration of Academic Freedom

    Directory of Open Access Journals (Sweden)

    Gökhan ÇETİNSAYA


    Full Text Available 1. Universities are the institutions where all the opinions, various truth claims as well as social and political problems are discussed in a liberal and civilized way and the complicated problems are expressed clearly without any oppression and prevention. 2. Academic freedom includes first and foremost the right of freedom of research and thus freedom of using the essential knowledge methods, the right of possessing the necessary tools and conditions required for the research and the rights of scientific production, informing, learning and dissemination. 3. Academics possess the rights to benefit from the academic freedom without any limitation, to research and investigate according to their own preferences and interests, and to teach these without being exposed to any oppression and prevention. 4. This freedom of teaching that the academics have should not be used in a manner restricting students' freedom of learning; academics should avoid from being dogmatic in the research and education processes and respect students' rights of thinking differently and expressing themselves. 5. Academics accordingly should lead the students to evaluate and understand the new thoughts as a whole and to be tolerant to the thoughts they do not agree and to think in various ways. Also, academics should encourage the students to create their own opinions based on evidences and enable them to express these opinions freely and respect their freedom of expression. 6. Campuses should be safe environments where the students can express their own opinions freely. Suppressing the intellectual diversity and the plurality of viewpoints will decrease the productivity of teaching and learning process, restrict students' freedom of learning, and constrain the chance of formation of critical and in-depth thinking. 7. Critical thinking develops only in the campuses where various thoughts are expressed in a liberal way. Students should feel that they would not be prevented

  6. Quantum fluids in the Kähler parametrization

    Energy Technology Data Exchange (ETDEWEB)

    Holender, L., E-mail: [Grupo de Física Teórica e Matemática Física, Departamento de Física, Universidade Federal Rural do Rio de Janeiro (UFRRJ), Cx. Postal 23851, BR 465 Km 7, 23890-000 Seropédica, RJ (Brazil); Santos, M.A., E-mail: [Departamento de Física e Química, Universidade Federal do Espírito Santo (UFES), Avenida Fernando Ferarri S/N, Goiabeiras, 29060-900 Vitória, ES (Brazil); Vancea, I.V., E-mail: [Grupo de Física Teórica e Matemática Física, Departamento de Física, Universidade Federal Rural do Rio de Janeiro (UFRRJ), Cx. Postal 23851, BR 465 Km 7, 23890-000 Seropédica, RJ (Brazil)


    In this Letter we address the problem of the quantization of the perfect relativistic fluids formulated in terms of the Kähler parametrization. This fluid model describes a large set of interesting systems such as the power law energy density fluids, Chaplygin gas, etc. In order to maintain the generality of the model, we apply the BRST method in the reduced phase space in which the fluid degrees of freedom are just the fluid potentials and the fluid current is classically resolved in terms of them. We determine the physical states in this setting, the time evolution and the path integral formulation. -- Highlights: ► We construct the BRST formulation of the quantum relativistic fluid. ► We determine the physical states in the reduced phase space. ► We determine the time evolution of the quantum fluid. ► We find the path integral formulation of the quantum fluid.

  7. Globalization and Economic Freedom

    DEFF Research Database (Denmark)

    Bjørnskov, Christian


    This paper employs a panel data set to estimate the effect of globalization on four measures of economic freedom. Contrary to previous studies, the paper distinguishes between three separate types of globalization: economic, social and political. It also separates effects for poor and rich...... countries, and autocracies and democracies. The results show that economic globalization is negatively associated with government size and positively with regulatory freedom in rich countries; social globalization is positively associated with legal quality in autocracies and with the access to sound money...... in democracies. Political globalization is not associated with economic freedom...

  8. Freedom in mundane mobilities

    DEFF Research Database (Denmark)

    Mikkelsen, Marie V.; Cohen, Scott A.


    of the world. Through in-situ interviews with families caravanning in Denmark, the primary aim of this study is to challenge existing dominant discourses surrounding the subject of freedom within leisure and tourism studies. Second, we shed further light on an under-researched medium of mobility......, that of domestic caravanning. This serves to not only disrupt representations of freedom as occurring through exoticised, masculinised and individualised practices, but to give attention to the domestic, banal contexts where the everyday and tourism intersect, which are often overlooked. This novel repositioning...... opens up new avenues in tourism studies for critical research into the geographies of freedom in mundane, everyday contexts....

  9. Turbine airfoil cooling system with cooling systems using high and low pressure cooling fluids

    Energy Technology Data Exchange (ETDEWEB)

    Marsh, Jan H.; Messmann, Stephen John; Scribner, Carmen Andrew


    A turbine airfoil cooling system including a low pressure cooling system and a high pressure cooling system for a turbine airfoil of a gas turbine engine is disclosed. In at least one embodiment, the low pressure cooling system may be an ambient air cooling system, and the high pressure cooling system may be a compressor bleed air cooling system. In at least one embodiment, the compressor bleed air cooling system in communication with a high pressure subsystem that may be a snubber cooling system positioned within a snubber. A delivery system including a movable air supply tube may be used to separate the low and high pressure cooling subsystems. The delivery system may enable high pressure cooling air to be passed to the snubber cooling system separate from low pressure cooling fluid supplied by the low pressure cooling system to other portions of the turbine airfoil cooling system.

  10. System and method for improving performance of a fluid sensor for an internal combustion engine (United States)

    Kubinski, David [Canton, MI; Zawacki, Garry [Livonia, MI


    A system and method for improving sensor performance of an on-board vehicle sensor, such as an exhaust gas sensor, while sensing a predetermined substance in a fluid flowing through a pipe include a structure for extending into the pipe and having at least one inlet for receiving fluid flowing through the pipe and at least one outlet generally opposite the at least one inlet, wherein the structure redirects substantially all fluid flowing from the at least one inlet to the sensor to provide a representative sample of the fluid to the sensor before returning the fluid through the at least one outlet.

  11. Optimal Configuration of Discrete Fluid Power Force System Utilised in the PTO for WECs

    DEFF Research Database (Denmark)

    Hansen, Anders Hedegaard; Pedersen, Henrik Clemmensen


    . Transferring from a continuous fluid power PTO-system to a discrete poses the question of configuration and control of the discrete fluid power system utilised in a wave energy converter (WEC). The current paper presents a method for determining the optimal configuration of a discrete fluid power force system...... for the PTO-system in a WEC. A model based optimisation is utilised to identify the system configuration leading to the highest energy output. It is shown how the time distribution of wave conditions affects the choice of system configuration. Based on the current paper the preferred PTO system configuration...

  12. An inertial parameter identification method of eliminating system damping effect for a six-degree-of-freedom parallel manipulator

    Directory of Open Access Journals (Sweden)

    Tian Tixian


    Full Text Available A new simple and effective inertial parameter identification method based on sinusoidal vibrations of a six-degree-of-freedom parallel manipulator is proposed. Compared with previously known identification algorithms, the advantages of the new approach are there is no need to design the excitation trajectory to consider the condition number of the observation matrix and the inertial matrix can be accurately defined regardless of the effect of viscous friction. In addition, the use of a sinusoidal exciting trajectory allows calculation of the velocities and accelerations from the measured position response. Simulations show that the new approach has acceptable tolerance of dry friction when using a simple coupling parameter modified formula. The experimental application to the hydraulically driven Stewart platform demonstrates the capability and efficiency of the proposed identification method.

  13. Personal Freedom beyond Limits

    Directory of Open Access Journals (Sweden)

    Juan Fernando Sellés


    Full Text Available In this work we distinguish between freedom in the human manifestations (intelligence, will,actions and personal freedom in the personal intimacy. This second is beyond the freedom reached bythe classic and modern thought, since it takes root in the personnel act of being. Because of it, it is not possible to characterize this freedom like the classic description as ‘domain over the own acts’, becauseit is a description of ‘categorial’ order; neither like present day ‘autonomy’ or ‘independence’, becausethe existence of one person alone is impossible, since ‘person’ means relation, personal free openingto other persons, description of the ‘transcendental’ order and, therefore, to the margin of limits.

  14. Human freedom and enhancement. (United States)

    Heilinger, Jan-Christoph; Crone, Katja


    Ideas about freedom and related concepts like autonomy and self-determination play a prominent role in the moral debate about human enhancement interventions. However, there is not a single understanding of freedom available, and arguments referring to freedom are simultaneously used to argue both for and against enhancement interventions. This gives rise to misunderstandings and polemical arguments. The paper attempts to disentangle the different distinguishable concepts, classifies them and shows how they relate to one another in order to allow for a more structured and clearer debate. It concludes in identifying the individual underpinnings and the social conditions of choice and decision-making as particularly salient dimensions of freedom in the ethical debate about human enhancement.

  15. Surfactant micelles: model systems for flow instabilities of complex fluids. (United States)

    Perge, Christophe; Fardin, Marc-Antoine; Manneville, Sébastien


    Complex fluids such as emulsions, colloidal gels, polymer or surfactant solutions are all characterized by the existence of a "microstructure" which may couple to an external flow on time scales that are easily probed in experiments. Such a coupling between flow and microstructure usually leads to instabilities under relatively weak shear flows that correspond to vanishingly small Reynolds numbers. Wormlike micellar surfactant solutions appear as model systems to study two examples of such instabilities, namely shear banding and elastic instabilities. Focusing on a semidilute sample we show that two-dimensional ultrafast ultrasonic imaging allows for a thorough investigation of unstable shear-banded micellar flows. In steady state, radial and azimuthal velocity components are recovered and unveil the original structure of the vortical flow within an elastically unstable high shear rate band. Furthermore thanks to an unprecedented frame rate of up to 20,000 fps, transients and fast dynamics can be resolved, which paves the way for a better understanding of elastic turbulence.

  16. A new converter for improving efficiency of multi-actuators fluid power system

    Energy Technology Data Exchange (ETDEWEB)

    Xue, Yong; Shang, JianZhong; Yang, JunHong; Wang Zhuo [National University of Defense Technology, Changsha (China)


    This paper is concerned with the application of energy efficient fluid power in mobile robots system and proposes a new fluid power converter system which is analogous to a boost converter in power electronics. The fluid power converter system is based on the principle of pulse-width modulation. The fluid power converter has an effect akin to an electrical switched inductance transformer, wherein the output pressure or flow rate can be stepped up or down. Using an inductive reactance device (an inertia mass-block), the output flow and pressure can be varied to meet the load by a means that does not rely on dissipation of power (the resistance control). The simulation model based on the mathematics models of the components is built to analyse the performance of the fluid power converter. It is clearly shown that the fluid power converter has higher energy efficiency than conventional resistance control manners.

  17. System for concentrating and analyzing particles suspended in a fluid (United States)

    Fiechtner, Gregory J [Bethesda, MD; Cummings, Eric B [Livermore, CA; Singh, Anup K [Danville, CA


    Disclosed is a device for separating and concentrating particles suspended in a fluid stream by using dielectrophoresis (DEP) to trap and/or deflect those particles as they migrate through a fluid channel. The method uses fluid channels designed to constrain a liquid flowing through it to uniform electrokinetic flow velocities. This behavior is achieved by connecting deep and shallow sections of channels, with the channel depth varying abruptly along an interface. By careful design of abrupt changes in specific permeability at the interface, an abrupt and spatially uniform change in electrokinetic force can be selected. Because these abrupt interfaces also cause a sharp gradient in applied electric fields, a DEP force also can be established along the interface. Depending on the complex conductivity of the suspended particles and the immersion liquid, the DEP force can controllably complement or oppose the local electrokinetic force transporting the fluid through the channel allowing for manipulation of particles suspended in the transporting liquid.

  18. Oil Impregnated Pressboard Barrier Systems Based on Ester Fluids for an Application in HVDC Insulation Systems

    Directory of Open Access Journals (Sweden)

    Patrick Rumpelt


    Full Text Available Ester-based insulation fluids are being increasingly used in high-voltage insulation systems. The reasons are the advantages in the area of ecological compatibility and resource-saving provision. The intention to use ester-based insulation fluids in high voltage direct current (HVDC equipment is new. The major challenge in designing the HVDC insulation system is, that the systems do not only experience an alternating voltage, but also a direct voltage Offset. This presents a challenge to predict the electric field distribution. For this purpose, basic investigations are carried out in the form of conductivity investigations for various insulation barrier systems. In addition, a mineral oil serves as a reference oil for estimating existing insights. The results show the influence of the ester-based insulating liquids on the direct current (DC conductivity for basic arrangements, consisting of pressboard barriers and mixed insulations.

  19. Contamination Control and Monitoring of Tap Water as Fluid in Industrial Tap Water Hydraulic Systems

    DEFF Research Database (Denmark)

    Conrad, Finn; Adelstorp, Anders


    Presentation of results and methods addressed to contamination control and monitoring of tap water as fluid in tap water hydraulic systems.......Presentation of results and methods addressed to contamination control and monitoring of tap water as fluid in tap water hydraulic systems....

  20. Theoretical aspects concerning working fluids in hydraulic systems

    Directory of Open Access Journals (Sweden)

    Tița Irina


    Full Text Available Among the properties of working fluid, viscosity is the most important as it regards especially to pumps. In order to study the behavior of hydrostatic transmission it is important to create a reliable research instrument for dynamic simulation. Our research expertise being in SimHydraulics consequently this instrument is the suitable block diagram. The purpose of this paper is to present the possible ways to customize the properties of the working fluid in the block diagram.

  1. Nursing diagnoses in women deprived of freedom

    Directory of Open Access Journals (Sweden)

    Izabelle de Freitas Ferreira


    Full Text Available Objective: to analyze the nursing diagnoses profile of women deprived of freedom, using the International Classification for Nursing® Practice version 1.0. Methods: a descriptive study, conducted with 186 women deprived of freedom. Nursing Diagnoses were extrapolated based on the clinical data of the participants, collected through a structured form and clinical reasoning. Results: there were 44 nursing diagnostic statements, among the most common, there were: infection risk (70.9%; fluid intake, decreased (61.2%; Sleep, impaired (60.7%; tobacco abuse, started (51.6%; health seeking behavior, committed (50.0%. Conclusion: the diagnoses are related to factors that compromise the biopsychosocial health. The nurse, health staff member in the prison setting, must recognize and assess the individual and collective needs of women deprived of freedom. The inference of nursing diagnoses, based on clinical reasoning, contributes to a humanized, empathic and special care.

  2. Pharmacy and freedom. (United States)

    Cowen, D L


    The development of pharmacy in Western civilization has been influenced by ideas of individual liberty; the impact of these ideas is traced. For a short time during the French Revolution, individuals without qualifications could practice pharmacy, but abuses prompted return of regulation; from 1803, pharmacy was closely regulated by the state. Liberal thinking in 19th-century Britain left control of pharmacy mainly within the profession; regulation was definitive rather than restrictive. With the influence of Jacksonian Democracy and freedom of trade in the United States, there were no effective pharmacy regulations until the late 19th century and few educational requirements for licensure until the 1920s. In Germany, the old system of concessions and privileges was upset after World War II when any qualified pharmacist was allowed to open a shop wherever desired in the American-occupied zone; the courts upheld this policy as the basis for establishment of pharmacies in West Germany. Liberty in dispensing drugs has been limited out of concern for the well-being of individuals and of society as a whole. In Great Britain and the U.S., restrictions on dispensing antedated laws establishing qualifications for pharmacists. The history of pharmacy demonstrates that there are moral and social barriers to realization of the ideals of liberty. History also suggests that if pharmacists assume responsibilities that use their specialized training, they can defend against inroads by nonpharmacists.

  3. Dynamics of fault-fluid-hydrate system around a shale-cored anticline in deepwater Nigeria (United States)

    Sultan, N.; Riboulot, V.; Ker, S.; Marsset, B.; GéLi, L.; Tary, J. B.; Klingelhoefer, F.; Voisset, M.; Lanfumey, V.; Colliat, J. L.; Adamy, J.; Grimaud, S.


    Gas hydrates were recovered by coring at the eastern border of a shale-cored anticline in the eastern Niger Delta. To characterize the link between faults and fluid release and to identify the role of fluid flow in the gas hydrate dynamics, three piezometers were deployed for periods ranging from 387 to 435 days. Two of them were deployed along a major fault linked to a shallow hydrocarbon reservoir while the third monitored the fluid pressure in a pockmark aligned above the same major fault. In addition, 10 ocean-bottom seismometers (OBS) were deployed for around 60 days. The piezometers simultaneously registered a prolonged fluid flow event lasting 90 days. During this time, OBS measurements record several episodic fluid release events. By combining and analyzing existing and newly acquired data, we show that the fluid-fault system operates according to the following three stages: (1) upward pore fluid migration through existing conduits and free gas circulation within several shallow sandy layers intersecting the major fault, (2) gas accumulation and pore pressure increases within sandy-silty layers, and (3) hydrofracturing and fluid pressure dissipation through sporadic degassing events, causing pore fluid circulation through shallow sandy layers and drawing overlying seawater into the sediment. This paper clearly demonstrates how an integrated approach based on seafloor observations, in situ measurements, and monitoring is essential for understanding fault-fluid-hydrate systems.

  4. Cerebrospinal fluid interleukin-6 in central nervous system inflammatory diseases.

    Directory of Open Access Journals (Sweden)

    Alexandre Wullschleger

    Full Text Available BACKGROUND: Interleukin (IL-6 is recognised as an important cytokine involved in inflammatory diseases of the central nervous system (CNS. OBJECTIVE: To perform a large retrospective study designed to test cerebrospinal fluid (CSF IL-6 levels in the context of neurological diseases, and evaluate its usefulness as a biomarker to help discriminate multiple sclerosis (MS from other inflammatory neurological diseases (OIND. PATIENTS AND METHODS: We analyzed 374 CSF samples for IL-6 using a quantitative enzyme-linked immunosorbent assay. Groups tested were composed of demyelinating diseases of the CNS (DD, n = 117, including relapsing-remitting MS (RRMS, n = 65, primary progressive MS (PPMS, n = 11, clinically isolated syndrome (CIS, n = 11, optic neuritis (ON, n = 30; idiopathic transverse myelitis (ITM, n = 10; other inflammatory neurological diseases (OIND, n = 35; and non-inflammatory neurological diseases (NIND, n = 212. Differences between groups were analysed using Kruskal-Wallis test and Mann-Whitney U-test. RESULTS: CSF IL-6 levels exceeded the positivity cut-off of 10 pg/ml in 18 (51.4% of the 35 OIND samples, but in only three (3.9% of the 76 MS samples collected. CSF IL-6 was negative for all NIND samples tested (0/212. IL-6 cut-off of 10 pg/ml offers 96% sensitivity to exclude MS. CONCLUSION: CSF IL-6 may help to differentiate MS from its major differential diagnosis group, OIND.

  5. Closed-loop feedback control for microfluidic systems through automated capacitive fluid height sensing


    Trumper, David; Kassis, Timothy; Griffith, Linda; Noh, Minkyun; Soenksen, Luis


    Precise fluid height sensing in open-channel microfluidics has long been a desirable feature for a wide range of applications. However, performing accurate measurements of the fluid level in small-scale reservoirs (<1mL) has proven to be an elusive goal, especially if direct fluid-sensor contact needs to be avoided. In particular, gravity-driven systems used in several microfluidic applications to establish pressure gradients and impose flow remain open-loop and largely unmonitored due to ...

  6. Coupling between electronic and lattice degrees of freedom in 4f-electron systems investigated by inelastic neutron scattering

    International Nuclear Information System (INIS)

    Loewenhaupt, M; Witte, U


    In general, elementary excitations in solids such as crystal field (CF) transitions and phonons are considered decoupled and the determination and interpretation of the measured spectra of the two phenomena, i.e. the CF level schemes and the phonon dispersion relations, are performed independently of each other. In addition, the spectra of these two excitations are generally quite complex and hence any unusual features are difficult to detect. A signature of a strong coupling between the two phenomena is the observation of an unusual behaviour in both subsystems. To prove the coupling unambiguously it is therefore necessary to investigate e.g. the phonon dispersion relations of an isostructural compound where the magnetic rare-earth ion (Ce, Yb) is replaced by a non-magnetic, but chemically equivalent ion (Y, La, Lu) and to determine the CF schemes of the same compound with the rare-earth ion replaced by a 'normal' magnetic rare earth. This requires, of course, time-consuming, detailed investigations. With these considerations in mind, it is not a surprise that there are only a few examples known where a coupling between electronic (CF transitions) and lattice (phonons) degrees of freedom have been reported. Here we will discuss results on three rare-earth compounds where the coupling between CF transitions and phonons has been unambiguously shown by inelastic neutron scattering experiments: CeAl 2 , YbPO 4 and CeCu 2

  7. Dynamic Characteristics Study with Multidegree-of-Freedom Coupling in TBM Cutterhead System Based on Complex Factors

    Directory of Open Access Journals (Sweden)

    Wei Sun


    Full Text Available A multidegree-of-freedom coupling dynamic model, which contains a joint cutterhead, an inner ring gear, a support shield body, and pinions, is established, considering the external stochastic excitations, time-varying meshing stiffness, transmission errors, clearance, and so forth. Based on the parameters of an actual project and the strong impact of external excitations, the modal properties and dynamic responses are analyzed, and the cutterhead joint surface loads are obtained and treated by rain flow count. Numerical results indicate that the low natural frequencies are 57 Hz and 61 Hz, and natural vibration modes are pinions-motors rotational mode and translational-overturning coupled mode of cutterhead with inner ring gear correspondingly. Besides, the axial and radial amplitude of dynamic responses are 0.55 mm and 0.25 mm, respectively. The frequencies of radial, torsional, and overturning vibrations are predominantly concentrated in 112 Hz and 120 Hz, which indicates that the vibration responses of cutterhead are mainly affected by the external excitations. Finally, as the rain-flow counting results have shown, the standard deviation of the cutterhead joint surface loads in each direction increases by 12–15 times, compared with that of the external excitations; therefore inertia effect should be considered in cutterhead design. The proposed research lays a foundation for dynamic performance optimization and fatigue crack growth life assessment of cutterhead structure.

  8. [Drug addiction and freedom]. (United States)

    Albuquerque, M A


    The author, in a historical and philosophical approach, analyses the concept of freedom as opposed to slavery. He also refers to the legal and social restrictions and studies the determinism and free will as the causes of human behaviour. Quoting Spinoza, the author states that man accepts the idea of freedom because he realizes the "how" of his options but ignores "why". Without the hypothesis of causality and determinism, there seems to have no science. Without freedom, there seems to be no anthropos man (Jimeno Valdez). The principles of anticausality, of nonreproducibility and of differentiation characterize the human freedom, but are contrary to the way science works. According to the social and political point of view, it was established that the State has the right to oblige and to violently limit freedom. Practically speaking, though, the State is violent just for being the State; the dominant groups are the government because they are and they have been violent. There is a need to limit and to discipline this right of the State of being violent within the dilemma of safety and freedom. By working, the slave avoided the whip. And by doing this, he encouraged the behaviour of the one who whipped him. The non-aversive attitudes limit the freedom in the modern world more and more for they also enchain our will, a rebellion becoming impossible. One is not granted the freedom; it shall be conquered and kept. Freedom, either as a concept or a phenomenon, is always relative. The concept of toxicomania or pharmacodependance is analysed according to the same perspective. The conclusion is that this is always more a problem of the society than of the individual, and this is how it has to be understood and treated. The present world is described as a millenial human culture specifically characterized by eight groups of phenomena: 1. Transport increased human mobility, reduced the relative dimensions of the earth, mixed peoples, compared cultures and created

  9. Passive control of the flutter instability on a two-degrees-of-freedom system with pseudoelastic shape-memory alloy springs.

    Directory of Open Access Journals (Sweden)

    Malher A.


    Full Text Available A passive control of aeroelastic instabilities on a two-degrees-of-freedom (dofs system is considered here using shape memory alloys (SMA springs in their pseudo-elastic regime. SMA present a solid-solid phase change that allow them to face strong deformations (∼ 10%; in the pseudo-elastic regime, an hysteresis loop appears in the stress-strain relationship which in turn gives rise to an important amount of dissipated energy. This property makes the SMA a natural candidate for damping undesired vibrations in a passive manner. A 2-dofs system is here used to model the classical flutter instability of a wing section in an uniform flow. The SMA spring is selected on the pitch mode in order to dissipate energy of the predominant motion. A simple model for the SMA hysteresis loop is introduced, allowing for a quantitative study of the important parameters to optimize in view of an experimental design.

  10. Multi-fluid renewable geo-energy systems and methods (United States)

    Buscheck, Thomas A.


    A geo-energy production method for extracting thermal energy from a reservoir formation. A production well extracts brine from the reservoir formation. A plurality of working fluid injection ("WFI") wells may be arranged proximate to the production well to at least partially circumscribe the production well. A plurality of brine production ("BP") wells may be arranged in a vicinity of the WFI wells to at least partially circumscribe the WFI wells. A working fluid is injected into the WFI wells to help drive a flow of the brine up through the production and BP wells, together with at least a portion of the injected working fluid. Parasitic-load time-shifting and to storing of excess solar thermal energy may also be performed.

  11. Design of Dual Mode RFID Antenna for Inventory Management and IV Fluid Level Warning System

    Directory of Open Access Journals (Sweden)

    Ssu-Han Ting


    Full Text Available Radio frequency identification (RFID readers are powered RF devices that communicate with an RFID tag to read necessary information. Using this capability, a dual use system for short distance inventory management and moderate distance automatic warning system for low intravenous (IV fluid levels is designed. The RFID is affixed on the IV drip bag; the fluid in bag affects the antenna transmission distance by fluid dielectric conditions. This allows for two different operational modes (moderate and short distance. For pharmaceutical management, a handheld RFID reader can be used for short distance application. Another stationary RFID system can serve as a warning system for long distance application such as hospital care.

  12. Freedom of Expression

    Directory of Open Access Journals (Sweden)

    Guilherme Canela


    Full Text Available The freedoms of expression and of the press are basic pillars of the western democracies. The contemporary theoretical framework which gives support to these rights was generated in the wake of the liberal revolutions which took place in Western Europe and in North America starting from the second half of the 1600s. Our purpose in this text is to present the current scene regarding this topic, focusing whenever pertinent on the Brazilian case, and seeking to question the unconditional defense of the freedoms of expression and of the press made by the thinkers who founded these principles vis-á-vis contemporary issues of the communicational universe. Going beyond theoretical-conceptual refl ections, we present and analyze the results of a content analysis showing how 53 Brazilian newspapers and 4 magazines with nationwide circulation report (or not topics relating to freedom of expression and of the press.

  13. Simulation of the instability in the stratified two-fluid system

    International Nuclear Information System (INIS)

    Cerne, G.; Tiselj, I.; Petelin, S.


    Two different models are combined together for the simulation of the Kelvin-Helmholtz instability in a channel. The disturbance on the interface of the initially stratified flow is amplifies and initiates dispersion of the fluids in the system. At the beginning sharp interface is needed to simulate the instability development therefore the VOF method was used. Later the two-fluid model is switched on in the domains where high dispersion of the fluids does not allow reliable use of the VOF method. The combined model enables the simulation of the whole two fluid phenomena.(author)

  14. SINDA/SINFLO computer routine, volume 1, revision A. [for fluid flow system analysis (United States)

    Oren, J. A.; Williams, D. R.


    The SINFLO package was developed to modify the SINDA preprocessor to accept and store the input data for fluid flow systems analysis and adding the FLOSOL user subroutine to perform the flow solution. This reduced and simplified the user input required for analysis of flow problems. A temperature calculation method, the flow-hybrid method which was developed in previous VSD thermal simulator routines, was incorporated for calculating fluid temperatures. The calculation method accuracy was improved by using fluid enthalpy rather than specific heat for the convective term of the fluid temperature equation. Subroutines and data input requirements are described along with user subroutines, flow data storage, and usage of the plot program.

  15. Ore-forming fluid system of bauxite in WZD area of northern Guizhou province, China (United States)

    Cui, Tao


    The ore-forming fluid system of bauxite in Wuchuan-Zheng,an-Daozhen (short for WZD) Area of northern Guizhou Province was studied from the perspective of deposit formation mechanism. It was discovered that ore-forming fluids were mainly effective for transporting and leaching during the formation of bauxite. The means of transport mainly included colloidal transport, suspended transport and gravity flow transport. In the course of their leaching, fluids had a range of chemical reactions, as a result of which elements such as silicon and iron migrated downwards. In this process, properties of fluids changed as well.

  16. Thoughts on freedom. (United States)

    Hallingby, L


    The tradition of personal freedom as Americans know it is not known in China. In America, people are free to choose their own lifestyle but they cannot walk the streets in safety for fear of crime and violence. In a sense, they are not free. In China, one is not free to choose an occupation and a place to live and work, but people are free to walk the streets in safety. Perhaps the true difference between the U.S. and China is not the presence or absence of freedom, but rather the nature of the freedom involved. There are certain underlying assumptions which explain why personal freedom is not very important in China: 1) everyone belongs to a series of larger units, the family, the neighborhood commune, and society; and 2) the effect of an individual's actions on the larger unit is more important than the immediate effect on the individual. Thus, the Chinese do not have the freedom to engage in self-defeating and self-destructive behavior that Americans tend to engage in. In the U.S., people have the right to become alcoholics, to become drug addicts and to have as many babies at as young an age as their bodies will allow. The negative effects of these types of behavior are less important to Americans as the individual's right to free choice. Sexual pleasures and sexual freedom are not paramount concerns in China, but there is 1 basic lifestyle which everyone is expected to follow: marriage, parenting of 1 child, living with the parents of 1 spouse or the other, and caring for one's parents in their old age. The Chinese are not free to choose to cohabitate without being married, to remain single, to remain childless, or to be single parents. These lifestyles and sexual practices find their roots in the fact that China is a monolithic society where everyone thinks and behaves in the same way, and also in the fact that sexual taboos are motivated by practical or economic, rather than religious and moral concerns. Although women are encouraged to have an abortion if

  17. Large eddy simulation on thermal fluid mixing in a T-junction piping system

    Energy Technology Data Exchange (ETDEWEB)

    Selvam, P. Karthick; Kulenovic, R.; Laurien, E. [Stuttgart Univ. (Germany). Inst fuer Kernenergie und Energiesysteme (IKE)


    High cycle thermal fatigue damage caused in piping systems is an important problem encountered in the context of nuclear safety and lifetime management of a Nuclear Power Plant (NPP). The T-junction piping system present in the Residual Heat Removal System (RHRS) is more vulnerable to thermal fatigue cracking. In this numerical study, thermal mixing of fluids at temperature difference (?T) of 117 K between the mixing fluids is analyzed. Large Eddy Simulation (LES) is performed with conjugate heat transfer between the fluid and structure. LES is performed based on the Fluid-Structure Interaction (FSI) test facility at University of Stuttgart. The results show an intense turbulent mixing of fluids downstream of T-junction. Amplitude of temperature fluctuations near the wall region and its corresponding frequency distribution is analyzed. LES is performed using commercial CFD software ANSYS CFX 14.0.

  18. Prospects of the use of nanofluids as working fluids for organic Rankine cycle power systems

    DEFF Research Database (Denmark)

    Mondejar, Maria E.; Andreasen, Jesper G.; Regidor, Maria


    The search of novel working fluids for organic Rankine cycle power systems is driven by the recent regulations imposing additional phase-out schedules for substances with adverse environmental characteristics. Recently, nanofluids (i.e. colloidal suspensions of nanoparticles in fluids) have been...... suggested as potential working fluids for organic Rankine cycle power systems due to their enhanced thermal properties, potentially giving advantages with respect to the design of the components and the cycle performance. Nevertheless, a number of challenges concerning the use of nanofluids must...... the prospects of using nanofluids as working fluids for organic Rankine cycle power systems. As a preliminary study, nanofluids consisting of a homogenous and stable mixture of different nanoparticles types and a selected organic fluid are simulated on a case study organic Rankine cycle unit for waste heat...

  19. Modelling of Mass Transfer Phenomena in Chemical and Biochemical Reactor Systems using Computational Fluid Dynamics

    DEFF Research Database (Denmark)

    Larsson, Hilde Kristina

    Computational fluid dynamics (CFD) is the application of numerical methods to solve systems of partial differential equations related to fluid dynamics. The continuity and the momentum equations are the most commonly applied equations within CFD, and together they can be used to calculate...... the velocity and pressure distributions in a fluid. CFD also enables the modelling of several fluids simultaneously, e.g. gas bubbles in a liquid, as well as the presence of turbulence and dissolved chemicals in a fluid, and many other phenomena. This makes CFD an appreciated tool for studying flow structures...... and an ion-exchange reaction are also modelled and compared to experimental data. The thesis includes a comprehensive overview of the fundamentals behind a CFD software, as well as a more detailed review of the fluid dynamic phenomena investigated in this project. The momentum and continuity equations...

  20. Systems and methods for thermal imaging technique for measuring mixing of fluids (United States)

    Booten, Charles; Tomerlin, Jeff; Winkler, Jon


    Systems and methods for thermal imaging for measuring mixing of fluids are provided. In one embodiment, a method for measuring mixing of gaseous fluids using thermal imaging comprises: positioning a thermal test medium parallel to a direction gaseous fluid flow from an outlet vent of a momentum source, wherein when the source is operating, the fluid flows across a surface of the medium; obtaining an ambient temperature value from a baseline thermal image of the surface; obtaining at least one operational thermal image of the surface when the fluid is flowing from the outlet vent across the surface, wherein the fluid has a temperature different than the ambient temperature; and calculating at least one temperature-difference fraction associated with at least a first position on the surface based on a difference between temperature measurements obtained from the at least one operational thermal image and the ambient temperature value.

  1. 76 FR 72243 - Proposed Information Collection (Operation Enduring Freedom/Operation Iraqi Freedom Veterans... (United States)


    ... AFFAIRS Proposed Information Collection (Operation Enduring Freedom/ Operation Iraqi Freedom Veterans... facilities for returning Operation Enduring Freedom/ Operation Iraqi Freedom veterans and their families.... Title: Operation Enduring Freedom/Operation Iraqi Freedom Veterans Health Needs Assessment, VA Form 10...

  2. Validation of a Micrometric remotely controlled pre-alignment system for the CLIC Linear Collider using a test setup (Mock-Up) with 5 degrees of freedom

    CERN Document Server

    Mainaud Durand, H; Griffet, S; Kemppinen, J; Leuxe, R; Sosin, M


    The CLIC main beam quadrupoles need to be prealigned within 17 um rms with respect to a straight reference line along a sliding window of 200 m. A readjustment system based on eccentric cam movers, which will provide stiffness to the support assembly, is being studied. The cam movers were qualified on a 1 degree of freedom (DOF) test setup, where a repeatability of adjustment below 1um was measured along their whole range. This paper presents the 5 DOF mock-up, built for the validation of the eccentric cam movers, as well as the first results of tests carried out: resolution of displacement along the whole range, measurements of the support eigenfrequencies.

  3. Issues and Feasibility Demonstration of Positioning Closed Loop Control for the CLIC Supporting System Using a Test Mock-up with Five Degrees of Freedom

    CERN Document Server

    Sosin, M; Chritin, N; Griffet, S; Kemppinen, J; Mainaud Durand, H; Rude, V; Sterbini, G


    Since several years, CERN is studying the feasibility of building a high energy e+ e- linear collider: the CLIC (Compact LInear Collider). One of the challenges of such a collider is the pre-alignment precision and accuracy requirement on the transverse positions of the linac components, which is typically 14 μm over a window of 200 m. To ensure the possibility of positioning within such tight constraints, CERN Beams Department’s Survey team has worked intensively at developing the methods and technology needed to achieve that objective. This paper describes activities which were performed on a test bench (mock-up) with five degrees of freedom (DOF) for the qualification of control algorithms for the CLIC supporting system active-pre-alignment. Present understanding, lessons learned (“know how”), issues of sensors noise and mechanical components nonlinearities are presented.

  4. Preheating of fluid in a supercritical Brayton cycle power generation system at cold startup (United States)

    Wright, Steven A.; Fuller, Robert L.


    Various technologies pertaining to causing fluid in a supercritical Brayton cycle power generation system to flow in a desired direction at cold startup of the system are described herein. A sensor is positioned at an inlet of a turbine, wherein the sensor is configured to output sensed temperatures of fluid at the inlet of the turbine. If the sensed temperature surpasses a predefined threshold, at least one operating parameter of the power generation system is altered.

  5. Freedom to Compete?

    DEFF Research Database (Denmark)

    Buch-Hansen, Hubert


    . To this end, the article focuses on companies associated with the European Roundtable of Industrialists (ERT), a highly influential network consisting of top executives from a range of Europe’s largest TNCs that has consistently urged political decision-makers to give companies the ‘freedom to compete’. We...

  6. Thinking Academic Freedom (United States)

    Lange, Lis


    This lecture argues that the politicisation and instrumentalisation of the university caused by neoliberal frames has as a result the depoliticisation of knowledge and of the academic as individual. This depoliticisation has turned academic freedom into a right to disengage not only from the political fight around these issues but also from the…

  7. Nursing and human freedom. (United States)

    Risjord, Mark


    Debates over how to conceptualize the nursing role were prominent in the nursing literature during the latter part of the twentieth century. There were, broadly, two schools of thought. Writers like Henderson and Orem used the idea of a self-care deficit to understand the nurse as doing for the patient what he or she could not do alone. Later writers found this paternalistic and emphasized the importance of the patient's free will. This essay uses the ideas of positive and negative freedom to explore the differing conceptions of autonomy which are implicit in this debate. The notion of positive freedom has often been criticized as paternalistic, and the criticisms of self-care in the nursing literature echo criticisms from political philosophy. Recent work on relational autonomy and on the relationship between autonomy and identity are used to address these objections. This essay argues for a more nuanced conception of the obligation to support autonomy that includes both positive (freedom to) and negative (freedom from) dimensions. This conception of autonomy provides a moral foundation for conceptualizing nursing in something like Henderson's terms: as involving the duty to expand the patient's capacities. The essay concludes by generalizing the lesson. Respect for autonomy on the part of any health care provider requires both respect for the patient's choices and a commitment to expand the patient's ability to actualize their choices. © 2013 John Wiley & Sons Ltd.

  8. Your True Freedom

    Directory of Open Access Journals (Sweden)

    Jena Rausch


    Full Text Available Your True Freedom is about my journey teaching inmates the fundamental truths of self worth, self acceptance and self love--through writing, mindfulness meditation and emotional healing. It is a journey that continues to enlighten me and to heal and free the inmates with whom I work.

  9. Design and Realization of a Three Degrees of Freedom Displacement Measurement System Composed of Hall Sensors Based on Magnetic Field Fitting by an Elliptic Function

    Directory of Open Access Journals (Sweden)

    Bo Zhao


    Full Text Available This paper presents the design and realization of a three degrees of freedom (DOFs displacement measurement system composed of Hall sensors, which is built for the XYθz displacement measurement of the short stroke stage of the reticle stage of lithography. The measurement system consists of three pairs of permanent magnets mounted on the same plane on the short stroke stage along the Y, Y, X directions, and three single axis Hall sensors correspondingly mounted on the frame of the reticle stage. The emphasis is placed on the decoupling and magnetic field fitting of the three DOFs measurement system. The model of the measurement system is illustrated, and the XY positions and θZ rotation of the short stroke stage can be obtained by decoupling the sensor outputs. A magnetic field fitting by an elliptic function-based compensation method is proposed. The practical field intensity of a permanent magnet at a certain plane height can be substituted for the output voltage of a Hall sensors, which can be expressed by the elliptic function through experimental data as the crucial issue to calculate the three DOFs displacement. Experimental results of the Hall sensor displacement measurement system are presented to validate the proposed three DOFs measurement system.

  10. Analysis and hazard evaluation of heat-transfer fluids for the direct contact cooling system

    International Nuclear Information System (INIS)

    Hong, Joo Hi; Lee, Yeon Hee; Shin, You Hwan; Karng, Sarng Woo; Kim, Seo Young; Kim, Young Gil


    This paper discusses several low-temperature heat-transfer fluids, including water-based inorganic salt, organic salt, alcohol/glycol mixtures, silicones, and halogenated hydrocarbons in order to choose the best heat-transfer fluid for the newly designed direct contact refrigeration system. So, it contains a survey on commercial products such as propylene glycol and potassium formate as newly used in super market and food processing refrigeration. The stability of commercial fluids at the working temperature of -20 .deg. C was monitored as a function of time up to two months. And organic and inorganic compositions of candidate fluids were obtained by analytical instruments such as ES, XRF, AAS, ICP-AES, GC, and GC-MS. Analysis results indicate that commercial propylene glycol is very efficient and safe heat transfer fluids for the direct cooling system with liquid phase

  11. Instabilities in vertically vibrated fluid-grain systems. (United States)

    King, P J; Lopez-Alcaraz, P; Pacheco-Martinez, H A; Clement, C P; Smith, A J; Swift, M R


    When a bed of fluid-immersed fine grains is exposed to vertical vibration a wealth of phenomena may be observed. At low frequencies a horizontal bed geometry is generally unstable and the bed breaks spatial symmetry, acquiring a tilt. At the same time it undergoes asymmetric granular convection. Fine binary mixtures may separate completely into layers or patterns of stripes. The separated regions may exhibit instabilities in which they undergo wave-like motion or exhibit quasi-periodic oscillations. We briefly review these and a number of related behaviours, identifying the physical mechanisms behind each. Finally, we discuss the magneto-vibratory separation of binary mixtures which results from exposing each component to a different effective gravity and describe the influence of a background fluid on this process.

  12. Performance of the mineral blended ester oil-based drilling fluid systems

    Energy Technology Data Exchange (ETDEWEB)

    Ismail, A.R.; Kamis, A.; Foo, K.S. [University Teknologi (Malaysia)


    A study was conducted in which the properties of ester oil-based drilling fluid systems were examined using a blended mixture of ester and synthetic mineral oil. Biodegradable invert emulsion ester-based fluids are preferred over mineral oil-based drilling fluids for environmental reasons, but they tend to cause alkaline hydrolysis resulting in solidification of the drilling fluid systems. The drilling fluid examined here consisted of Malaysian palm oil ester derivatives (methyl laureate ester or isopropyl laureate ester) blended with commercially available synthetic mineral oil. This mineral oil was added to reduce the problem of alkaline hydrolysis. This mixture, however, was found to be unstable and could not solve the problem at high temperature. The isopropyl laureate and mineral oil blended system was more stable towards the hydrolysis process up to 250 degrees F. In order to enhance the performance of an invert emulsion drilling fluid system, it was recommended that brine water content of the fluid system be lowered. 3 refs., 2 figs.

  13. Balanced Flow Metering and Conditioning: Technology for Fluid Systems (United States)

    Kelley, Anthony R.


    Revolutionary new technology that creates balanced conditions across the face of a multi-hole orifice plate has been developed, patented and exclusively licensed for commercialization. This balanced flow technology simultaneously measures mass flow rate, volumetric flow rate, and fluid density with little or no straight pipe run requirements. Initially, the balanced plate was a drop in replacement for a traditional orifice plate, but testing revealed substantially better performance as compared to the orifice plate such as, 10 times better accuracy, 2 times faster (shorter distance) pressure recovery, 15 times less acoustic noise energy generation, and 2.5 times less permanent pressure loss. During 2004 testing at MSFC, testing revealed several configurations of the balanced flow meter that match the accuracy of Venturi meters while having only slightly more permanent pressure loss. However, the balanced meter only requires a 0.25 inch plate and has no upstream or downstream straight pipe requirements. As a fluid conditioning device, the fluid usually reaches fully developed flow within 1 pipe diameter of the balanced conditioning plate. This paper will describe the basic balanced flow metering technology, provide performance details generated by testing to date and provide implementation details along with calculations required for differing degrees of flow metering accuracy.

  14. Freedom of Expression and the High School Press (United States)

    Reed, Linda


    Discusses practical resources available to high school administrators, teachers, and students through the ERIC system concerning freedom of speech for students involved with school-sponsored publications. (Author)

  15. Integrated Reacting Fluid Dynamics and Predictive Materials Degradation Models for Propulsion System Conditions, Phase I (United States)

    National Aeronautics and Space Administration — Computational fluid dynamics (CFD) simulations are routinely used by NASA to optimize the design of propulsion systems. Current methods for CFD modeling rely on...

  16. Closed-loop feedback control for microfluidic systems through automated capacitive fluid height sensing. (United States)

    Soenksen, L R; Kassis, T; Noh, M; Griffith, L G; Trumper, D L


    Precise fluid height sensing in open-channel microfluidics has long been a desirable feature for a wide range of applications. However, performing accurate measurements of the fluid level in small-scale reservoirs (<1 mL) has proven to be an elusive goal, especially if direct fluid-sensor contact needs to be avoided. In particular, gravity-driven systems used in several microfluidic applications to establish pressure gradients and impose flow remain open-loop and largely unmonitored due to these sensing limitations. Here we present an optimized self-shielded coplanar capacitive sensor design and automated control system to provide submillimeter fluid-height resolution (∼250 μm) and control of small-scale open reservoirs without the need for direct fluid contact. Results from testing and validation of our optimized sensor and system also suggest that accurate fluid height information can be used to robustly characterize, calibrate and dynamically control a range of microfluidic systems with complex pumping mechanisms, even in cell culture conditions. Capacitive sensing technology provides a scalable and cost-effective way to enable continuous monitoring and closed-loop feedback control of fluid volumes in small-scale gravity-dominated wells in a variety of microfluidic applications.

  17. Evaluation of temporal surveillance system sensitivity and freedom from bovine viral diarrhea in Danish dairy herds using scenario tree modelling

    DEFF Research Database (Denmark)

    Foddai, Alessandro; Stockmarr, Anders; Boklund, Anette


    The temporal sensitivity of the surveillance system (TemSSe) for Bovine Viral Diarrhea (BVD) in Danish dairy herds was evaluated. Currently, the Danish antibody blocking ELISA is used to test quarterly bulk tank milk (BTM). To optimize the surveillance system as an early warning system, we...

  18. Magnetohydrodynamic pump with a system for promoting flow of fluid in one direction (United States)

    Lemoff, Asuncion V [Union City, CA; Lee, Abraham P [Irvine, CA


    A magnetohydrodynamic pump for pumping a fluid. The pump includes a microfluidic channel for channeling the fluid, a MHD electrode/magnet system operatively connected to the microfluidic channel, and a system for promoting flow of the fluid in one direction in the microfluidic channel. The pump has uses in the medical and biotechnology industries for blood-cell-separation equipment, biochemical assays, chemical synthesis, genetic analysis, drug screening, an array of antigen-antibody reactions, combinatorial chemistry, drug testing, medical and biological diagnostics, and combinatorial chemistry. The pump also has uses in electrochromatography, surface micromachining, laser ablation, inkjet printers, and mechanical micromilling.

  19. Fluid Interfaces

    DEFF Research Database (Denmark)

    Hansen, Klaus Marius


    Fluid interaction, interaction by the user with the system that causes few breakdowns, is essential to many user interfaces. We present two concrete software systems that try to support fluid interaction for different work practices. Furthermore, we present specificity, generality, and minimality...... as design goals for fluid interfaces....

  20. Freedom of Speech: A Clear and Present Need to Teach. ERIC Report. (United States)

    Boileau, Don M.


    Presents annotations of 21 documents in the ERIC system on the following subjects: (1) theory of freedom of speech; (2) theorists; (3) research on freedom of speech; (4) broadcasting and freedom of speech; and (5) international questions of freedom of speech. (PD)

  1. Usefulness of high-resolution thermography in fault diagnosis of fluid power components and systems (United States)

    Pietola, Matti; Varrio, Jukka P.


    Infrared thermography has been used routinely in industrial applications for quite a long time. For example, the condition of electric power lines, district heating networks, electric circuits and components, heat exchangers, pipes and its insulations, cooling towers, and various machines and motors is monitored using infrared imaging techniques. Also the usage of this technology in predictive maintenance has proved successful, mainly because of effective computers and tailored softwares available. However, the usage of thermal sensing technique in fluid power systems and components (or other automation systems in fact) is not as common. One apparent reason is that a fluid power circuit is not (and nor is a hydraulic component) an easy object of making thermal image analyses. Especially the high flow speed, fast pressure changes and fast movements make the diagnosis complex and difficult. Also the number of people whose knowledge is good both in thermography and fluid power systems is not significant. In this paper a preliminary study of how thermography could be used in the condition monitoring, fault diagnosis and predictive maintenance of fluid power components and systems is presented. The shortages and limitations of thermal imaging in the condition monitoring of fluid power are also discussed. Among many other cases the following is discussed: (1) pressure valves (leakage, wrong settings), (2) check valves (leakage); (3) cylinders (leakage and other damages); (4) directional valves and valve assemblies; (5) pumps and motors (leakage in piston or control plate, bearings). The biggest advantage of using thermography in the predictive maintenance and fault diagnosis of fluid power components and systems could be achieved in the process industry and perhaps in the commissioning of fluid power systems in the industry. In the industry the predictive maintenance of fluid power with the aid of an infrared camera could be done as part of a condition monitoring of

  2. Knowledge Yearning for Freedom

    Directory of Open Access Journals (Sweden)

    Ljiljana Gavrilović


    Full Text Available The paper is concerned with the restriction of access to knowledge/books in the contemporary digitalized global world, in which the access to knowledge has to be paid for, and wherein definitions of modes of payment control who has or doesn’t have the right to knowledge. The second part of the article deals with the struggle for the freedom of words/knowledge, and actions through which the authors/producers of knowledge and art fight the restrictions not only to the freedom of speech, but also creativity and innovation, which should be the aim of all copyright and intellectual right laws, the contemporary application of which has become its own opposite.

  3. Bioethics and academic freedom. (United States)

    Singer, Peter


    The author describes the events surrounding his attempts to lecture on the subject of euthanasia in West Germany in June 1989. Singer, who defends the view that active euthanasia for some newborns with handicaps may be ethically permissible, had been invited to speak to professional and academic groups. Strong public protests against Singer and his topic led to the cancellation of some of his engagements, disruptions during others, and harrassment of the German academics who had invited him to speak. These incidents and the subject of euthanasia became matters of intense national debate in West Germany, but there was little public or academic support for Singer's right to be heard. Singer argues that bioethics and bioethicists must have the freedom to challenge conventional moral beliefs, and that the events in West Germany illustrate the grave danger to that freedom from religious and political intolerance.

  4. "Development as Freedom"


    Haider Ali Khan


    This chapter offers a historical and analytical introduction to the school of thought that views 'development as freedom'. Since it is impossible to do justice to the depth and complexity of this 'new' approach to development in just one short chapter, I explore a few significant dimensions of the concept beginning with Amartya Sen's pioneering contributions. I also look at clarifications by Nussbaum and others who offer a list of important functionings that can be included in the capabilitie...

  5. Academic Freedom: The Ethical Imperative (United States)

    Slattery, Patrick


    In this article, the author takes his cue for discussions of academic freedom from Simone de Beauvoir as found in her classic text, "The Ethics of Ambiguity." Like other existentialists, de Beauvoir emphasizes that freedom and responsibility are intimately linked. Academic freedom is an ethical responsibility that compels the author to teach and…

  6. Intellectual Workers and Essential Freedoms. (United States)

    Edley, Christopher Jr.


    Journalists and college professors deserve certain privileges, including freedom of speech and academic freedom, but they must adapt their work to increasingly diverse populations. They must confront public mistrust, convince people that these freedoms are worthwhile, and protect essential public rights through what they study and teach and to…

  7. Evaluation of a Novel Controlled Cutting Fluid Impinging Supply System When Machining Titanium Alloys

    Directory of Open Access Journals (Sweden)

    Salah Gariani


    Full Text Available Following a comprehensive review on titanium machining and methods of cutting fluid application, this paper presents a new Controlled cutting fluid impinging supply system (Cut‐list developed to deliver an accurate amount of cutting fluid into the machining zone via wellpositioned coherent nozzles based on the calculation of the heat generated. The performance of the new system was evaluated against a conventional flood cutting fluid supply system during step shoulder milling of Ti‐6Al‐4V using vegetable oil‐based cutting fluid. The comparison was performed at different cutting speeds and feed rates. Comparison measures/indicators were cutting force, workpiece temperature, tool flank wear, burr formation and average surface roughness (Ra. The new system provided significant reductions in cutting fluid consumption of up to 42%. Additionally, reductions in cutting force, tool flank wear and burr height of 16.41%, 46.77%, and 31.70% were recorded, respectively. Smaller Ra values were also found with the use of the new system.

  8. A new fluid distribution system for scale-flexible expanded bed adsorption

    DEFF Research Database (Denmark)

    Hubbuch, Jürgen; Heebøll-Nielsen, Anders; Hobley, Timothy John


    A new fluid distribution system designed for expanded bed adsorption was introduced and studied in a 150-cm diameter column. Based on fluid application through a rotating distributor, it eradicates the need for perforated plates, meshes, or local mixers. The effect of rotation rate on column...... change in expansion characteristics as distributor rotation rate was increased from 2.5 to 10 rpm. The distributor was observed to generate a flow pattern suitable for expanded bed adsorption when the supports were fluidized at a superficial fluid velocity of 283 cm (.) h(-1) and dye pulses introduced...

  9. Potential landscape and flux field theory for turbulence and nonequilibrium fluid systems (United States)

    Wu, Wei; Zhang, Feng; Wang, Jin


    Turbulence is a paradigm for far-from-equilibrium systems without time reversal symmetry. To capture the nonequilibrium irreversible nature of turbulence and investigate its implications, we develop a potential landscape and flux field theory for turbulent flow and more general nonequilibrium fluid systems governed by stochastic Navier-Stokes equations. We find that equilibrium fluid systems with time reversibility are characterized by a detailed balance constraint that quantifies the detailed balance condition. In nonequilibrium fluid systems with nonequilibrium steady states, detailed balance breaking leads directly to a pair of interconnected consequences, namely, the non-Gaussian potential landscape and the irreversible probability flux, forming a 'nonequilibrium trinity'. The nonequilibrium trinity characterizes the nonequilibrium irreversible essence of fluid systems with intrinsic time irreversibility and is manifested in various aspects of these systems. The nonequilibrium stochastic dynamics of fluid systems including turbulence with detailed balance breaking is shown to be driven by both the non-Gaussian potential landscape gradient and the irreversible probability flux, together with the reversible convective force and the stochastic stirring force. We reveal an underlying connection of the energy flux essential for turbulence energy cascade to the irreversible probability flux and the non-Gaussian potential landscape generated by detailed balance breaking. Using the energy flux as a center of connection, we demonstrate that the four-fifths law in fully developed turbulence is a consequence and reflection of the nonequilibrium trinity. We also show how the nonequilibrium trinity can affect the scaling laws in turbulence.

  10. Towards the proof of complete integrability of quantum elliptic many-body systems with spin degrees of freedom

    Czech Academy of Sciences Publication Activity Database

    Dittrich, Jaroslav; Inozemtsev, V. I.


    Roč. 14, č. 2 (2009), s. 218-222 ISSN 1560-3547 R&D Projects: GA MŠk(CZ) LC06002; GA MŠk(CZ) LA08002 Institutional research plan: CEZ:AV0Z10480505 Keywords : quantum elliptic spin system * transposition * integrability Subject RIV: BE - Theoretical Physics Impact factor: 0.725, year: 2009

  11. Study on the annular leakage-flow-induced vibrations. 1st Report. Stability for translational and rotational single-degree-of-freedom systems; Kanjo sukimaryu reiki shindo ni kansuru kenkyu. 1. Heishin oyobi kaiten 1 jiyudokei no anteise

    Energy Technology Data Exchange (ETDEWEB)

    Li, D.W. [Hitachi, Ltd., Tokyo (Japan); Kaneko, S. [The University of Tokyo, Tokyo (Japan); Hayama, S. [Toyama Prefectural University, Toyama (Japan)


    This study reports the stability of annular leakage-flow-induced vibrations. The pressure distribution of fluid between a fixed outer cylinder and a vibrating inner cylinder was obtained in the case of a translationally and rotationally coupled motion of the inner cylinder. The unsteady fluid force acting on the inner cylinder in the case of translational and rotational single-degree-of-freedom vibrations was then expressed in terms proportional to the acceleration, velocity, and displacement. Then the critical flow rate (at which stability was lost) was determined for an annular leakage-flow-induced vibration. Finally, the stability was investigated theoretically. It is known that instability will occur in the case of a divergent passage, but the critical flow rate depends on the passage increment in a limited range: the eccentricity of the passage and the pressure loss factor at the inlet of the passage lower the stability. (author)

  12. Modeling Two-Phase Flow and Vapor Cycles Using the Generalized Fluid System Simulation Program (United States)

    Smith, Amanda D.; Majumdar, Alok K.


    This work presents three new applications for the general purpose fluid network solver code GFSSP developed at NASA's Marshall Space Flight Center: (1) cooling tower, (2) vapor-compression refrigeration system, and (3) vapor-expansion power generation system. These systems are widely used across engineering disciplines in a variety of energy systems, and these models expand the capabilities and the use of GFSSP to include fluids and features that are not part of its present set of provided examples. GFSSP provides pressure, temperature, and species concentrations at designated locations, or nodes, within a fluid network based on a finite volume formulation of thermodynamics and conservation laws. This paper describes the theoretical basis for the construction of the models, their implementation in the current GFSSP modeling system, and a brief evaluation of the usefulness of the model results, as well as their applicability toward a broader spectrum of analytical problems in both university teaching and engineering research.

  13. Polydispersity effect on solid-fluid transition in hard sphere systems

    KAUST Repository

    Nogawa, T.


    The solid-fluid transition of the hard elastic particle system with size polydispersity is studied by molecular dynamics simulations. Using nonequilibrium relaxation from the mixed initial condition we determines the melting point where the first order transition between the solid, fcc crystal, and fluid states occurs. It is found that the density gap between the bistable states decreases with increasing the strength of the polydispersity and continuously approaches to zero at the critical point. © 2010.

  14. Coupled fluid structural analysis for a spherical BWR containment with pressure suppression system

    International Nuclear Information System (INIS)

    Krieg, R.; Goeller, B.; Hailfinger, G.


    The condensation of steam, blown into the water pool of the pressure suppression system of a boiling water reactor, causes pressure oscillations in the pool and, as a consequence, corresponding vibrations of the surrounding walls. However, as a feed back, also the structural deformations of the walls have a considerable influence on the pressure fields in the water pool. Therefore, a theoretical investigation of the dynamics of the pressure suppression system cannot be subdivided in a separate analysis of the fluid behaviour, followed by calculations of the structural response. Rather an analysis taking into account the fluid structural coupling must be carried through. Often this is achieved by a step-by-step technique where in the simplest case for small time steps either the pressures or the accelerations at the fluid-structural interface are extrapolated, separate codes for fluid and structural dynamics check whether the extrapolated values satisfy the interface conditions and an iterative improvement is made if necessary. Although in this method standard fluid and structural dynamics codes can be used as moduls and non-linearities can be treated easily, an essential drawback is that often a very large number of time steps is required in order to obtain numerical stability. Therefore, in this paper a so-called simultaneous coupling technique is used (computer code SING-S), where the unknown structural loadings at the fluid-structural interfaces are eliminiated by direct substitution of relations describing the fluid dynamics. Neglecting the fluid compressibility, equations of motion for the coupled problem are obtained which have the same form as the equations of motion for the structural dynamics without coupling. Only the masses are changed. They include now the added mass effect from the fluid. Consequently, for the further treatment of the coupled problem similar methods may be used as in pure structural dynamics. (orig.)

  15. Ecosystem-based management of a Mediterranean urban wastewater system: a sensitivity analysis of the operational degrees of freedom. (United States)

    Corominas, Lluís; Neumann, Marc B


    Urban wastewater systems discharge organic matter, nutrients and other pollutants (including toxic substances) to receiving waters, even after removing more than 90% of incoming pollutants from human activities. Understanding their interactions with the receiving water bodies is essential for the implementation of ecosystem-based management strategies. Using mathematical modeling and sensitivity analysis we quantified how 19 operational variables of an urban wastewater system affect river water quality. The mathematical model of the Congost system (in the Besòs catchment, Spain) characterizes the dynamic interactions between sewers, storage tanks, wastewater treatment plants and the river. The sensitivity analysis shows that the use of storage tanks for peak shaving and the use of a connection between two neighboring wastewater treatment plants are the most important factors influencing river water quality. We study how the sensitivity of the water quality variables towards changes in the operational variables varies along the river due to discharge locations and river self-purification processes. We demonstrate how to use the approach to identify interactions and how to discard non-influential operational variables. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. 76 FR 58565 - Proposed Information Collection (Operation Enduring Freedom/Operation Iraqi Freedom Seriously... (United States)


    ... AFFAIRS Proposed Information Collection (Operation Enduring Freedom/ Operation Iraqi Freedom Seriously... Enduring Freedom/Operation Iraqi Freedom veterans regarding benefits. DATES: Written comments and... techniques or the use of other forms of information technology. Title: Operation Enduring Freedom/Operation...

  17. Diagnostic value of pleural fluid obtained from a chest tube collection system. (United States)

    Reed, Robert M; Eberlein, Michael; Netzer, Giora; Pickering, Edward; Shanholtz, Carl; Verceles, Avelino C; McCurdy, Michael T


    Pleural fluid is typically drawn directly from the pleural space for diagnostic studies, but occasionally analyses are desired when a chest tube is already in place and a traditional approach is not feasible. The diagnostic value of analyzing fluid samples obtained from the pleural fluid collection system after chest tube insertion is unknown. We performed a prospective observational study of patients in whom chest tube placement was planned for clinical indications. Diagnostic studies were performed on fluid obtained from the pleural space at the time of tube insertion and then repeated 2, 6, and 24 h later on samples obtained from the fluid collection system. Fifty-five percent of the 23 effusions studied met light's criteria for exudate at baseline. Lactate dehydrogenase (LDH) varied considerably over time from baseline measures with only 25 % of measures at 24 h falling within 25 % of baseline levels. The sensitivity for exudate by LDH remained 100 % with poor specificity ranging 50-69 % with repeat measures. Total protein exhibited less variability with 85 % of measures at 24 h falling within 25 % of baseline measure. Sensitivity and specificity at 24 h were 88 and 82 %, respectively. Repeat measures of cholesterol, albumin, and triglycerides generally correlated well (Spearman's rho > 0.90) with baseline values. Measures of glucose and cell counts varied considerably from baseline. Analysis of pleural fluid from a chest tube collection system is feasible and can provide useful diagnostic information. Practitioners should consider the test characteristics of each measure when interpreting samples obtained.

  18. Fluid-structure interaction in BWR suppression pool systems. Final report

    International Nuclear Information System (INIS)

    Nickell, R.E.


    The discharge of safety relief valves or a severe loss-of-coolant event in a boiling-water-cooled reactor steam supply system triggers a complex pressure suppression system that is based upon sub-surface steam condensation in large pools of water. The physical problems fall into two categories. The first is referred to as vent clearing and describes the process of expelling non-condensables from the system prior to steam flow. The second category covers a variety of phenomena related to the transient overexpansion of a condensable volume and the subsequent inertially-driven volume decrease. The dynamic loading of either event, depending upon fluid-structural design parameters, can be of concern in safety analysis. This report describes the development of a method for calculating the loads and the structural response for both types of problems. The method is embedded in a computer code, called PELE-IC, that couples a two-dimensional, incompressible eulerian fluid algorithm to a finite element shell algorithm. The fluid physics is based upon the SOLA algorithm, which provideds a trial velocity field using the Navier-Stokes equations that is subsequently corrected iteratively so that incompressibility, fluid-structure interface compatibility, and boundary conditions are satisfied. These fluid and fluid-structure algorithms have been extensively verified through calculations of known solutions from the classical literature, and by comparison to air and steam blowdown experiments

  19. Excited-state quantum phase transitions in systems with two degrees of freedom: II. Finite-size effects

    Energy Technology Data Exchange (ETDEWEB)

    Stránský, Pavel [Institute of Particle and Nuclear Physics, Faculty of Mathematics and Physics, Charles University, V Holešovičkách 2, 18000 Prague (Czech Republic); Macek, Michal [Institute of Particle and Nuclear Physics, Faculty of Mathematics and Physics, Charles University, V Holešovičkách 2, 18000 Prague (Czech Republic); Center for Theoretical Physics, Sloane Physics Laboratory, Yale University, New Haven, CT 06520-8120 (United States); Leviatan, Amiram [Racah Institute of Physics, The Hebrew University, 91904 Jerusalem (Israel); Cejnar, Pavel, E-mail: [Institute of Particle and Nuclear Physics, Faculty of Mathematics and Physics, Charles University, V Holešovičkách 2, 18000 Prague (Czech Republic)


    This article extends our previous analysis Stránský et al. (2014) of Excited-State Quantum Phase Transitions (ESQPTs) in systems of dimension two. We focus on the oscillatory component of the quantum state density in connection with ESQPT structures accompanying a first-order ground-state transition. It is shown that a separable (integrable) system can develop rather strong finite-size precursors of ESQPT expressed as singularities in the oscillatory component of the state density. The singularities originate in effectively 1-dimensional dynamics and in some cases appear in multiple replicas with increasing excitation energy. Using a specific model example, we demonstrate that these precursors are rather resistant to proliferation of chaotic dynamics. - Highlights: • Oscillatory components of state density and spectral flow studied near ESQPTs. • Enhanced finite-size precursors of ESQPT caused by fully/partly separable dynamics. • These precursors appear due to criticality of a subsystem with lower dimension. • Separability-induced finite-size effects disappear in case of fully chaotic dynamics.

  20. Flow of Fluid and Particle Assemblages in Rotating Systems (United States)

    Kizito, John; Hiltner, David; Niederhaus, Charles; Kleis, Stanley; Hudson, Ed; Gonda, Steve


    NASA-designed bioreactors have been highly successful in growing three-dimensional tissue structures in a low shear environment both on earth and in space. The goal of the present study is to characterize the fluid flow environment within the HFB-S bioreactor and determine the spatial distribution of particles that mimic cellular tissue structures. The results will be used to obtain optimal operating conditions of rotation rates and media perfusehnfuse rates which are required for cell culture growth protocols. Two types of experiments have been performed so far. First, we have performed laser florescent dye visualization of the perfusion loop to determine the mixing times within the chamber. The second type of experiments involved particles which represent cellular tissue to determine the spatial distribution with the chamber. From these experiments we established that mixing times were largely dependant on the speed ratio and sign of the difference between the spinner and the dome. The shortest mixing times occurred when the spinner rotates faster than the dome and longest mixing times occurs with no relative motion between the dome and spinner. Also, we have determined the spatial and temporal distribution of particle assemblages within the chamber.

  1. Wired to freedom

    DEFF Research Database (Denmark)

    Jepsen, Kim Sune Karrasch; Bertilsson, Margareta


    dimension of life science through a notion of public politics adopted from the political theory of John Dewey. We show how cochlear implantation engages different social imaginaries on the collective and individual levels and we suggest that users share an imaginary of being “wired to freedom” that involves...... new access to social life, continuous communicative challenges, common practices, and experiences. In looking at their lives as “wired to freedom,” we hope to promote a wider spectrum of civic participation in the benefit of future life science developments within and beyond the field of Cochlear...

  2. Development of fluid system design technology for integral reactor

    Energy Technology Data Exchange (ETDEWEB)

    Lee, D. J.; Chang, M. H.; Kang, D. J. and others


    This study presents the technology development of the system design concepts of SMART, a multi-purposed integral reactor with enhanced safety and operability, for use in diverse usages and applications of the nuclear energy. This report contains the following; - Design characteristics - Performance and safety related design criteria - System description: Primary system, Secondary system, Residual heat removal system, Make-up system, Component cooling system, Safety system - Development of design computer code: Steam generator performance(ONCESG), Pressurizer performance(COLDPZR), Steam generator flow instability(SGINS) - Development of component module and modeling using MMS computer code - Design calculation: Steam generator thermal sizing, Analysis of feed-water temperature increase at a low flow rate, Evaluation of thermal efficiency in the secondary system, Inlet orifice throttling coefficient for the prevention of steam generator flow instability, Analysis of Nitrogen gas temperature in the pressurizer during heat-up process, evaluation of water chemistry and erosion etc. The results of this study can be utilized not only for the foundation technology of the next phase basic system design of the SMART but also for the basic model in optimizing the system concepts for future advanced reactors. (author)

  3. Dissertation Defense: Computational Fluid Dynamics Uncertainty Analysis for Payload Fairing Spacecraft Environmental Control Systems (United States)

    Groves, Curtis Edward


    Spacecraft thermal protection systems are at risk of being damaged due to airflow produced from Environmental Control Systems. There are inherent uncertainties and errors associated with using Computational Fluid Dynamics to predict the airflow field around a spacecraft from the Environmental Control System. This paper describes an approach to quantify the uncertainty in using Computational Fluid Dynamics to predict airflow speeds around an encapsulated spacecraft without the use of test data. Quantifying the uncertainty in analytical predictions is imperative to the success of any simulation-based product. The method could provide an alternative to traditional validation by test only mentality. This method could be extended to other disciplines and has potential to provide uncertainty for any numerical simulation, thus lowering the cost of performing these verifications while increasing the confidence in those predictions.Spacecraft requirements can include a maximum airflow speed to protect delicate instruments during ground processing. Computational Fluid Dynamics can be used to verify these requirements; however, the model must be validated by test data. This research includes the following three objectives and methods. Objective one is develop, model, and perform a Computational Fluid Dynamics analysis of three (3) generic, non-proprietary, environmental control systems and spacecraft configurations. Several commercially available and open source solvers have the capability to model the turbulent, highly three-dimensional, incompressible flow regime. The proposed method uses FLUENT, STARCCM+, and OPENFOAM. Objective two is to perform an uncertainty analysis of the Computational Fluid Dynamics model using the methodology found in Comprehensive Approach to Verification and Validation of Computational Fluid Dynamics Simulations. This method requires three separate grids and solutions, which quantify the error bars around Computational Fluid Dynamics predictions

  4. Dissertation Defense Computational Fluid Dynamics Uncertainty Analysis for Payload Fairing Spacecraft Environmental Control Systems (United States)

    Groves, Curtis Edward


    Spacecraft thermal protection systems are at risk of being damaged due to airflow produced from Environmental Control Systems. There are inherent uncertainties and errors associated with using Computational Fluid Dynamics to predict the airflow field around a spacecraft from the Environmental Control System. This paper describes an approach to quantify the uncertainty in using Computational Fluid Dynamics to predict airflow speeds around an encapsulated spacecraft without the use of test data. Quantifying the uncertainty in analytical predictions is imperative to the success of any simulation-based product. The method could provide an alternative to traditional "validation by test only" mentality. This method could be extended to other disciplines and has potential to provide uncertainty for any numerical simulation, thus lowering the cost of performing these verifications while increasing the confidence in those predictions. Spacecraft requirements can include a maximum airflow speed to protect delicate instruments during ground processing. Computational Fluid Dynamics can be used to verify these requirements; however, the model must be validated by test data. This research includes the following three objectives and methods. Objective one is develop, model, and perform a Computational Fluid Dynamics analysis of three (3) generic, non-proprietary, environmental control systems and spacecraft configurations. Several commercially available and open source solvers have the capability to model the turbulent, highly three-dimensional, incompressible flow regime. The proposed method uses FLUENT, STARCCM+, and OPENFOAM. Objective two is to perform an uncertainty analysis of the Computational Fluid Dynamics model using the methodology found in "Comprehensive Approach to Verification and Validation of Computational Fluid Dynamics Simulations". This method requires three separate grids and solutions, which quantify the error bars around Computational Fluid Dynamics

  5. Computational Fluid Dynamics Uncertainty Analysis for Payload Fairing Spacecraft Environmental Control Systems (United States)

    Groves, Curtis E.


    Spacecraft thermal protection systems are at risk of being damaged due to airflow produced from Environmental Control Systems. There are inherent uncertainties and errors associated with using Computational Fluid Dynamics to predict the airflow field around a spacecraft from the Environmental Control System. This proposal describes an approach to validate the uncertainty in using Computational Fluid Dynamics to predict airflow speeds around an encapsulated spacecraft. The research described here is absolutely cutting edge. Quantifying the uncertainty in analytical predictions is imperative to the success of any simulation-based product. The method could provide an alternative to traditional"validation by test only'' mentality. This method could be extended to other disciplines and has potential to provide uncertainty for any numerical simulation, thus lowering the cost of performing these verifications while increasing the confidence in those predictions. Spacecraft requirements can include a maximum airflow speed to protect delicate instruments during ground processing. Computationaf Fluid Dynamics can be used to veritY these requirements; however, the model must be validated by test data. The proposed research project includes the following three objectives and methods. Objective one is develop, model, and perform a Computational Fluid Dynamics analysis of three (3) generic, non-proprietary, environmental control systems and spacecraft configurations. Several commercially available solvers have the capability to model the turbulent, highly three-dimensional, incompressible flow regime. The proposed method uses FLUENT and OPEN FOAM. Objective two is to perform an uncertainty analysis of the Computational Fluid . . . Dynamics model using the methodology found in "Comprehensive Approach to Verification and Validation of Computational Fluid Dynamics Simulations". This method requires three separate grids and solutions, which quantify the error bars around

  6. Analysis of the susceptibility in a fluid system with Neumann – plus boundary conditions

    Directory of Open Access Journals (Sweden)

    Djondjorov Peter


    Full Text Available The behaviour of the local and total susceptibilities of a fluid system bounded by different surfaces is studied in the framework of the Ginsburg-Landau Ising type model. The case of a plain geometry, Neumann-infinity boundary conditions under variations of the temperature and an external ordering field is considered. Exact analytic expressions for the order parameter, local and total susceptibilities in such a system are presented. They are used to analyse the phase behaviour of fluids confined in regions close to the bulk critical point of the respective infinite system.

  7. A high-force controllable MR fluid damper–liquid spring suspension system

    International Nuclear Information System (INIS)

    Raja, Pramod; Wang, Xiaojie; Gordaninejad, Faramarz


    The goal of the present research is to investigate the feasibility of incorporating a liquid spring in a semi-active suspension system for use in heavy off-road vehicles. A compact compressible magneto-rheological (MR) fluid damper–liquid spring (CMRFD–LS) with high spring rate is designed, developed and tested. Compressible MR fluids with liquid spring and variable damping characteristics are used. These fluids can offer unique functions in reducing the volume/weight of vehicle struts and improving vehicle dynamic stability and safety. The proposed device consists of a cylinder and piston–rod arrangement with an internal annular MR fluid valve. The internal pressures in the chambers on either side of the piston develop the spring force, while the pressure difference across the MR valve produces the damping force, when the fluid flows through the MR valve. Harmonic characterization of the CMRFD–LS is performed and the force–displacement results are presented. A fluid-mechanics based model is also developed to predict the performance of the system at different operating conditions and compared to the experimental results. Good agreement between the experimental results and theoretical predictions has been achieved. (paper)

  8. Slavery, antislavery, freedom

    Directory of Open Access Journals (Sweden)

    Bridget Brereton


    Full Text Available [First paragraph] Empire and Antislavery: Spain, Cuba, and Puerto Rico, 1833-1874. CHRISTOPHER SCHMIDT-NOWARA. Pittsburgh PA: University of Pittsburgh Press, 1999. xv + 239 pp. (Cloth US$ 50.00, Paper US$ 22.95 Beyond Slavery: Explorations of Race, Labor, and Citizenship in Postemancipation Societies. FREDERICK COOPER, THOMAS C. HOLT & REBECCA J. SCOTT. Chapel Hill: University of North Carolina Press, 2000. xiii + 198 pp. (Cloth US$ 34.95, Paper US$ 15.95 From Slavery to Freedom: Comparative Studies in the Rise andFall of Atlantic Slavery. SEYMOUR DRESCHER. New York: New York University Press, 1999. xxv + 454 pp. (Cloth US$ 45.00 Terms of Labor: Slavery, Serfdom, and Free Labor. STANLEY L. ENGERMAN (ed.. Stanford CA: Stanford University Press, 1999. vi + 350 pp. (Cloth US$ 55.00 These four books explore antislavery movements in the Atlantic world, and consider some of the consequences of abolition in postemancipation societies. They are immensely rich studies which engage one of the liveliest areas of enquiry in modern historiography - the transition from slavery to freedom in New World societies - and which represent U.S. historical scholarship at its finest. Each falls into a different category of academic publication.

  9. An Innovative Improvement of Engineering Learning System Using Computational Fluid Dynamics Concept (United States)

    Hung, T. C.; Wang, S. K.; Tai, S. W.; Hung, C. T.


    An innovative concept of an electronic learning system has been established in an attempt to achieve a technology that provides engineering students with an instructive and affordable framework for learning engineering-related courses. This system utilizes an existing Computational Fluid Dynamics (CFD) package, Active Server Pages programming,…

  10. Computational Fluid Dynamics Uncertainty Analysis for Payload Fairing Spacecraft Environmental Control Systems (United States)

    Groves, Curtis; Ilie, Marcel; Schallhorn, Paul


    Spacecraft components may be damaged due to airflow produced by Environmental Control Systems (ECS). There are uncertainties and errors associated with using Computational Fluid Dynamics (CFD) to predict the flow field around a spacecraft from the ECS System. This paper describes an approach to estimate the uncertainty in using CFD to predict the airflow speeds around an encapsulated spacecraft.

  11. The Cocos Ridge hydrothermal system revealed by microthermometry of fluid and melt inclusions (United States)

    Brandstätter, J.; Kurz, W.; Krenn, K.


    Microthermometric analyses of fluid and melt inclusions in hydrothermal veins and in the Cocos Ridge (CCR) basalt were used to reveal the CCR thermal history at IODP Site 344-U1414 and to constrain fluid source and flow. Hydrothermal veins are hosted by lithified sediments and CCR basalt . Site 344-U1414, located 1 km seaward of the Middle American Trench offshore Costa Rica, serves to evaluate fluid/rock interaction, the hydrologic system and geochemical processes linked with the tectonic evolution of the incoming Cocos Plate from the Early Miocene up to recent times. The veins in the sedimentary rocks are mainly filled by blocky calcite, containing numerous fluid inclusions, and sometimes crosscut fibrous quartz/chalcedony veins. The veins in the basalt can be differentiated into three types: antitaxial fibrous calcite veins, composite veins with fibrous calcite and clay minerals at the vein margins and spherulitic quartz in the center, and syntaxial blocky aragonite veins surrounded by a clay selvage in the uppermost CCR basalt sections. Secondary minerals, clay minerals, fibrous calcite, quartz/chalcedony and pyrite also filled vesicles in the basalt. Fluid inclusions were mainly found in the aragonite veins and rarely in quartz in the composite veins and vesicles. Blocky veins with embedded wall rock fragments appear in the sediments and in the basalt indicate hydraulic fracturing. The occurrence of decrepitated fluid inclusions show high homogenization temperatures up to 400 °C. Decrepitated fluid inclusions are formed by increased internal overpressure, related to isobaric heating. Elongated fluid inclusion planes, arc-like fluid inclusions and low homogenization temperatures indicate subsequent isobaric cooling. The results obtained so far from Raman spectroscopy and microthermometry indicate CO2 inclusions and petrographic observations suggest the presence of silicate melt inclusions in phenocrysts in the basalt (mainly in clinopyroxene and plagioclase

  12. Smart Fluid Systems: The Advent of Autonomous Liquid Robotics


    Chiolerio, A.; Quadrelli, Marco B.


    Organic, inorganic or hybrid devices in the liquid state, kept in a fixed volume by surface tension or by a confining membrane that protects them from a harsh environment, could be used as biologically inspired autonomous robotic systems with unique capabilities. They could change shape according to a specific exogenous command or by means of a fully integrated adaptive system, and provide an innovative solution for many future applications, such as space exploration in extreme or otherwise c...

  13. The fluid-filling system for the Borexino solar neutrino detector

    Energy Technology Data Exchange (ETDEWEB)

    Benziger, J. [Chemical Engineering Department, Princeton University, Princeton, NJ 08544 (United States)], E-mail:; Cadonati, L.; Calaprice, F.; Chen, M. [Physics Department, Princeton University, Princeton, NJ 08544 (United States); Corsi, A. [INFN, Laboratori Nazionale di Gran Sasso (Italy); Dalnoki-Veress, F.; Fernholz, R.; Ford, R.; Galbiati, C.; Goretti, A.; Harding, E. [Physics Department, Princeton University, Princeton, NJ 08544 (United States); Ianni, Aldo [INFN, Laboratori Nazionale di Gran Sasso (Italy); Ianni, Andrea; Kidner, S.; Leung, M.; Loeser, F.; McCarty, K.; McKinsey, D.; Nelson, A.; Pocar, A. [Physics Department, Princeton University, Princeton, NJ 08544 (United States)] (and others)


    The system for controlled filling of the nested flexible scintillator containment vessels in the Borexino solar neutrino detector is described. The design and operation principles of pressure and shape monitoring systems are presented for gas filling, gas displacement by water, and water displacement by scintillator. System specifications for safety against overstressing the flexible nylon vessels are defined as well as leak-tightness and cleanliness requirements. The fluid-filling system was a major engineering challenge for the Borexino detector.

  14. The fluid-filling system for the Borexino solar neutrino detector (United States)

    Benziger, J.; Cadonati, L.; Calaprice, F.; Chen, M.; Corsi, A.; Dalnoki-Veress, F.; Fernholz, R.; Ford, R.; Galbiati, C.; Goretti, A.; Harding, E.; Ianni, Aldo; Ianni, Andrea; Kidner, S.; Leung, M.; Loeser, F.; McCarty, K.; McKinsey, D.; Nelson, A.; Pocar, A.; Salvo, C.; Schimizzi, D.; Shutt, T.; Sonnenschein, A.


    The system for controlled filling of the nested flexible scintillator containment vessels in the Borexino solar neutrino detector is described. The design and operation principles of pressure and shape monitoring systems are presented for gas filling, gas displacement by water, and water displacement by scintillator. System specifications for safety against overstressing the flexible nylon vessels are defined as well as leak-tightness and cleanliness requirements. The fluid-filling system was a major engineering challenge for the Borexino detector.

  15. Fluid lipid bilayers: Intermonolayer coupling and its thermodynamic manifestations

    DEFF Research Database (Denmark)

    Hansen, Per Lyngs; Miao, Ling; Ipsen, John Hjorth


    possesses "in-plane" degrees of freedom that characterize its physical or chemical state. Thermally excitable deformations of a Lipid bilayer in its geometrical conformation further impart to it ''out-of-plane'' degrees of freedom. In this paper we discuss the issue of intermonolayer coupling in terms......A fluid membrane of lipid bilayer consists of two individual molecular monolayers physically opposed to each other. This unique molecular architecture naturally necessitates the need to treat a lipid-bilayer membrane as one entity of two coupled two-dimensional systems (monolayers), each of which...

  16. Academic Freedom as Fundamental Right


    Cippitani, Roberto


    [EN] The paper aims at defining in particular the concept of academic freedom within the context of the European legal sources. Even though the idea of a special corporative status for professors was born during the Middle Ages, it was only during the second half of the twentieth century that the Constitutions recognised academic freedom as an individual’s legal right.. Such an individual right is regulated within the category of the freedom of expression, even if it is characteri...

  17. Energy Cost of Avoiding Pressure Oscillations in a Discrete Fluid Power Force System

    DEFF Research Database (Denmark)

    Hansen, Anders Hedegaard; Pedersen, Henrik Clemmensen


    In secondary valve controlled discrete fluid power force systems the valve opening trajectory greatly influences the pressure dynamics in the actuator chambers. For discrete fluid power systems featuring hoses of significant length pressure oscillations due to fast valve switching is well......-known. This paper builds upon theoretical findings on how shaping of the valve opening may reduce the cylinder pressure oscillations. The current paper extents the work by implementing the valve opening characteristics reducing the pressure oscillations on a full scale power take-off test-bench for wave energy...

  18. Role of the Enteric Nervous System in the Fluid and Electrolyte Secretion of Rotavirus Diarrhea (United States)

    Lundgren, Ove; Peregrin, Attila Timar; Persson, Kjell; Kordasti, Shirin; Uhnoo, Ingrid; Svensson, Lennart


    The mechanism underlying the intestinal fluid loss in rotavirus diarrhea, which often afflicts children in developing countries, is not known. One hypothesis is that the rotavirus evokes intestinal fluid and electrolyte secretion by activation of the nervous system in the intestinal wall, the enteric nervous system (ENS). Four different drugs that inhibit ENS functions were used to obtain experimental evidence for this hypothesis in mice in vitro and in vivo. The involvement of the ENS in rotavirus diarrhea indicates potential sites of action for drugs in the treatment of the disease.

  19. Numerical Modeling of Pressurization of Cryogenic Propellant Tank for Integrated Vehicle Fluid System (United States)

    Majumdar, Alok K.; LeClair, Andre C.; Hedayat, Ali


    This paper presents a numerical model of pressurization of a cryogenic propellant tank for the Integrated Vehicle Fluid (IVF) system using the Generalized Fluid System Simulation Program (GFSSP). The IVF propulsion system, being developed by United Launch Alliance, uses boiloff propellants to drive thrusters for the reaction control system as well as to run internal combustion engines to develop power and drive compressors to pressurize propellant tanks. NASA Marshall Space Flight Center (MSFC) has been running tests to verify the functioning of the IVF system using a flight tank. GFSSP, a finite volume based flow network analysis software developed at MSFC, has been used to develop an integrated model of the tank and the pressurization system. This paper presents an iterative algorithm for converging the interface boundary conditions between different component models of a large system model. The model results have been compared with test data.

  20. Numerical Modeling of an Integrated Vehicle Fluids System Loop for Pressurizing a Cryogenic Tank (United States)

    LeClair, A. C.; Hedayat, A.; Majumdar, A. K.


    This paper presents a numerical model of the pressurization loop of the Integrated Vehicle Fluids (IVF) system using the Generalized Fluid System Simulation Program (GFSSP). The IVF propulsion system, being developed by United Launch Alliance to reduce system weight and enhance reliability, uses boiloff propellants to drive thrusters for the reaction control system as well as to run internal combustion engines to develop power and drive compressors to pressurize propellant tanks. NASA Marshall Space Flight Center (MSFC) conducted tests to verify the functioning of the IVF system using a flight-like tank. GFSSP, a finite volume based flow network analysis software developed at MSFC, has been used to support the test program. This paper presents the simulation of three different test series, comparison of numerical prediction and test data and a novel method of presenting data in a dimensionless form. The paper also presents a methodology of implementing a compressor map in a system level code.

  1. Simulating coupled dynamics of a rigid-flexible multibody system and compressible fluid (United States)

    Hu, Wei; Tian, Qiang; Hu, HaiYan


    As a subsequent work of previous studies of authors, a new parallel computation approach is proposed to simulate the coupled dynamics of a rigid-flexible multibody system and compressible fluid. In this approach, the smoothed particle hydrodynamics (SPH) method is used to model the compressible fluid, the natural coordinate formulation (NCF) and absolute nodal coordinate formulation (ANCF) are used to model the rigid and flexible bodies, respectively. In order to model the compressible fluid properly and efficiently via SPH method, three measures are taken as follows. The first is to use the Riemann solver to cope with the fluid compressibility, the second is to define virtual particles of SPH to model the dynamic interaction between the fluid and the multibody system, and the third is to impose the boundary conditions of periodical inflow and outflow to reduce the number of SPH particles involved in the computation process. Afterwards, a parallel computation strategy is proposed based on the graphics processing unit (GPU) to detect the neighboring SPH particles and to solve the dynamic equations of SPH particles in order to improve the computation efficiency. Meanwhile, the generalized-alpha algorithm is used to solve the dynamic equations of the multibody system. Finally, four case studies are given to validate the proposed parallel computation approach.

  2. Dynamic Analysis of a Rigid Body Mounting System with Flexible Foundation Subject to Fluid Loading

    Directory of Open Access Journals (Sweden)

    J.S. Tao


    Full Text Available This paper presents an investigation of the force transmission from a rigid body mounting system to a flexible foundation with light and heavy fluid loading under the force and moment excitation. The analytical expression has been derived in which the flexible foundation effects are incorporated into a revised system stiffness matrix that is derived from the receptance matrix at mounting points. A typical case with a thin infinite plate as the foundation has been studied with the point and transfer receptances theoretically and numerically analysed in the case of light and heavy fluid loading. The results show that, compared with the rigid foundation, the force transmission is reduced and system natural frequencies are shifted. The detailed analysis demonstrates that the force reduction and frequency shifting are more obvious at low frequencies where the receptance value is significant. The study is also carried out to compare the transfer receptances from different waves in plate as it couples with water with the objective to simplify the calculation of receptance. It is found that, in the low frequency and after a short distance from driving point, the transfer receptance calculation for the heavy fluid loading can be simplified by only accounting the contribution from free wave which may easily be evaluated from the point receptance in air. It implies the plate response under heavy fluid loading could be directly derived from that with light fluid loading.

  3. Wear forms of heterogeneous electro-rheological fluids working in a hydraulic clutch system (United States)

    Ziabska, E.; Duchowski, J.; Olszak, A.; Osowski, K.; Kesy, A.; Kesy, Z.; Choi, S. B.


    The paper presents experimental results concerning the wear of heterogeneous electro-rheological (ER) fluids operating as working fluids in a complex clutch system consisting of a hydrodynamic clutch and a cylinder viscous clutch. The change of electric field intensity in the clutches results in change of sheer stress values in working fluids what causes the change of transmitted torque. This work shows that the most important factors affecting the wear of the ER fluid are the electric field of high intensity, the accompanying electrical breakdown, and the high temperature of the silicone oil. In addition, the water from the humid air absorbed mainly by hygroscopic particles influences a significant impact on the wear of the working fluid. Various forms of wear particles of the fluid depending on the prevailing conditions such as working mode are observed from the microscopic aspects. It is observed that the particles are flattened, rolled out or smashed into smaller fragments, partially melted, wrinkled and glued or caked. In addition, it is identified that the partial destruction of silicone oil is occurred due to the damage of the hydrocarbon chains, as evidenced by the decrease in its viscosity and the presence of the particle matter newly containing silicon.

  4. Considerations of a nonhomogeneous fluid in the deep groundwater flow system at Hanford

    International Nuclear Information System (INIS)

    Nelson, R.W.


    This report presents such a general theory capable of describing the flow on nonhomogeneous fluids in porous media, theory that is a composite from several disciplines including groundwater hydrology, soil physics, civil engineering, petroleum reservoir engineering, mechanics, and mathematical physics. The report discussed the conceptual basis for considering the flow of nonhomogeneous fluids. From this conceptual basis emphasis shifts to providing complete definitions and then appropriately describing those definitions in mathematical terms. Throughout the report, the necessary assumptions are stated in detail because the limitations of any theory are best assessed through careful scrutiny of the assumptions. From the mathematical definitions with appropriate functional dependence the results and constraints needed are derived to provide the general theory necessary to describe the flow of nonhomogeneous fluids in porous media. Particular attention is given to comparing the general theory with the classical theory of flow for a homogeneous fluid. Such comparison provides significant insight to the effects of variable fluid properties on subsurface flow systems. The comparisons also indicate the importance of carefully formulating subsurface flow models within the more general theoretical framework describing the flow of nonhomogeneous fluids in porous media. 29 refs.; 6 figs.; 1 tab

  5. Which Freedom of the Press?

    DEFF Research Database (Denmark)

    Rytter, Jens Elo


    The article surveys the historical and current meaning of "Freedom of the Press" in constitutional and human rights law. Two different conceptions exist, the narrow one defining freedom of the press as the freedom of every one to publish without prior restraint, the broader one defining it as a...... privileged freedom of the organised press to gather and report on information of public interest. These two conceptions have very different answers to the question of whether the press should enjoy some privilege to be exempt from ordinary legislation when such legislation restricts the access of the press to inform...

  6. Refining the Subseafloor Circulation Model of the Middle Valley Hydrothermal System Using Fluid Geochemistry (United States)

    Inderbitzen, K. E.; Wheat, C. G.; Baker, P. A.; Fisher, A. T.


    Currently, fluid circulation patterns and the evolution of rock/fluid compositions as circulation occurs in subseafloor hydrothermal systems are poorly constrained. Sedimented spreading centers provide a unique opportunity to study subsurface flow because sediment acts as an insulating blanket that traps heat from the cooling magma body and limits: (a) potential flow paths for seawater to recharge the aquifer in permeable upper basaltic basement and (b) points of altered fluid egress. This also allows for a range of thermal and geochemical gradients to exist near the sediment-water interface. Models of fluid circulation patterns in this type of hydrologic setting have been generated (eg. Stein and Fisher, 2001); however fluid chemistry datasets have not previously been used to test the model's viability. We address this issue by integrating the existing circulation model with fluid compositional data collected from sediment pore waters and high temperature hydrothermal vents located in Middle Valley on the Juan de Fuca Ridge. Middle Valley hosts a variety of hydrologic regimes: including areas of fluid recharge (Site 855), active venting (Site 858/1036; Dead Dog vent field), recent venting (Site 856/1035; Bent Hill Massive Sulfide deposit) and a section of heavily sedimented basement located between recharge and discharge sites (Site 857). We will present new results based on thermal and geochemical data from the area of active venting (Sites 858 and 1036), that was collected during Ocean Drilling Program Legs 139 and 169 and a subsequent heat flow/gravity coring effort. These results illuminate fine scale controls on secondary recharge and fluid flow within the sediment section at Site 858/1036. The current status of high temperature vents in this area (based on observations made in July, 2014) will also be outlined.

  7. Dynamical systems approach to models in fluid mechanics

    Czech Academy of Sciences Publication Activity Database

    Feireisl, Eduard


    Roč. 69, č. 2 (2014), s. 331-357 ISSN 0036-0279 EU Projects: European Commission(XE) 320078 - MATHEF Keywords : Navier-Stokes-Fourier system * weak solution * long-time behaviour Subject RIV: BA - General Mathematics Impact factor: 1.036, year: 2014

  8. Leak detection system for a high temperature fluid pipe

    International Nuclear Information System (INIS)

    Puyal, C.; Meuwisse, C.


    The leak detection system is made by a cable with at least two isolated electrical conductors, close to the wall of the pipe. The material of the cable is chosen so as to change its electrical characteristics if a leak causes heating of the cable. A detector at one end of the cable can measure the modifications of the electrical characteristics [fr

  9. Fluid Analysis of Network Content Dissemination and Cloud Systems (United States)


    performance in complex network content dissemination and cloud systems . We employed tools of queueing theory, convex optimization and control theory, to...optimization problem, and solve it in cases of practical interest. Numerous insights on practical caching mechanisms result from this mathematical ...

  10. Relative entropies in thermodynamics of complete fluid systems

    Czech Academy of Sciences Publication Activity Database

    Feireisl, Eduard


    Roč. 32, č. 9 (2012), s. 3059-3080 ISSN 1078-0947 R&D Projects: GA ČR GA201/09/0917 Institutional research plan: CEZ:AV0Z10190503 Keywords : relative entropy * Navier-Stokes-Fourier system * weak-strong uniqueness Subject RIV: BA - General Mathematics Impact factor: 1.005, year: 2012

  11. Long time behavior and attractors for energetically insulated fluid systems

    Czech Academy of Sciences Publication Activity Database

    Feireisl, Eduard


    Roč. 27, č. 4 (2010), s. 1587-1609 ISSN 1078-0947 R&D Projects: GA ČR GA201/09/0917 Institutional research plan: CEZ:AV0Z10190503 Keywords : Navier-Stokes-Fourier system * attractor * long time behavior Subject RIV: BA - General Mathematics Impact factor: 0.986, year: 2010

  12. Study the effect of synthesized graft copolymer on the inhibitive water based drilling fluid system

    Directory of Open Access Journals (Sweden)

    Rajat Jain


    Full Text Available This research paper consists of the synthesis of carboxymethyl-graft-polyacrylamide copolymer by free radical polymerization technique and its characterization using Fourier transform infrared spectroscopy (FTIR, field-emission scanning electron microscopy (FESEM and thermogravimetric analysis. This graft copolymer was used as a drilling fluid additive and its effect on the Indian reactive shale sample was analyzed. The characterization of the shale sample used in this study was done by X-ray diffraction technique (XRD, FTIR, FESEM, and energy-dispersive X-ray spectroscopy (EDX to determine the presence of various clay minerals. Experimental investigations revealed that the synthesized graft copolymer has a significant effect on the rheological and filtration properties of the inhibitive drilling fluid system and has high shale recovery performance. Hence, inhibitive drilling fluid system using synthesized graft copolymer may be used for the drilling of water sensitive shale formations.

  13. Experimental system model of a primary active fluid

    International Nuclear Information System (INIS)

    Deseigne, Julien


    Collective motion, such as flocks of birds or shoals of fish, is ubiquitous in nature. Such fundamentally out-of-equilibrium phenomena may be described with the new conceptual background of polar active matter, a system of polar particles which enables to use provided energy in order to move in their own directions. A 2D experimental system of vibrated polar disks that interact only by contact has been set up. These disks behave as random walkers, whose trajectories are characterized by a persistence length greater than their size and controlled by the angular fluctuations of their polarity. The interplay between the hard-core repulsion and the persistence of the motion leads to complex alignment modes. For instance, only 10 pc of the binary collisions correspond to an effective ferromagnetic alignment. Yet, spontaneous collective motion inside the system characterized by giant fluctuations of density have been observed. These results reveal the robustness of the polar order observed in theoretical and numerical models of 2D polar active matter on substrate

  14. Freedom of Speech: Its Exercise and Its Interpretation (United States)

    Turner, David A.


    Professor Roy Harris (2009) criticises me for ignoring freedom of speech in order to focus on "soft" issues, such as game theory, decision theory and chaos theory. In this response, I accept most of his arguments relating to freedom of speech, but argue that, in order to develop better systems of education, we need to pay more attention to the…

  15. The Challenge of Academic Freedom in the Nigerian University ...

    African Journals Online (AJOL)

    This paper takes a cursory look at the extent to which the Nigerian university system has enjoyed academic freedom. It observes that within the framework of the National Policy on Education (2004), universities in Nigeria are expected to enjoy the traditional areas of freedom in the areas of selection of students; appointment ...

  16. Freedom and european military conflicts.

    Directory of Open Access Journals (Sweden)

    Ks. Archimandryta Andrzej (Borkowski


    Full Text Available In the period of globalization, numerous armed conflicts and wars we often appeal to freedom and human rights. When we talk of freedom in the time we live in we usually mean it to be a possibility of free choice among various things. In contemporary common understanding freedom means choice. Such a definition is far insufficient to an Orthodox Christian. Freedom is something more than a simple difference between obviousness and indecision. Our spiritual attention needs to be directed towards something much more deeper. It should be directed to a struggle in order to overcome results of our fallen nature. According to contemporary understanding freedom is identified also with a possibility to do what is pleasing to ourselves. But such understanding is equally faulty. From theological point of view the term of true freedom denotes God’s grace and therefore human freedom is connected with and dependent on the absolute freedom of God. We do believe that God is the only giver of freedom and justice and He even exceeds them. God does not determine Himself. God simply exists. In such a way God has introduced Himself to Mores in the burning bush: „Εγώ ειμί ο Ών” (I am that I am. Ultimately all the contemporary crisises have their source in an absolute external freedom, freedom of flesh – having lost the notion of sin it transforms into a merciless, tyrannical lawlessness. Distinct manifestation of it are incessant armed conflicts in Europe.

  17. Alternative solutions for the CFC fluids in the refrigerating systems

    International Nuclear Information System (INIS)

    Ciconkov, Risto


    This paper deals with: -Characteristics that the alternative refrigerants should satisfy: chemical, thermal, health, safety, environmental, etc. -A survey of the newest refrigerants on the world market from the biggest well known companies. -Dilemmas about the choice of new refrigerants depending to the appliance in refrigerating systems. -Specific requirements that have to be known concerning the introduction of new refrigerants in exploitation. -Alternative refrigerants with natural origin, their positive and negative characteristics from the aspect of application. -Different viewpoints of the actual situation and perspective developing ways in this field, expecting new, more restrictive regulations to environment qualities. -The role of the national strategy now and in the future. (author)

  18. Electrohydrodynamic aspects of two-fluid microfluidic systems

    DEFF Research Database (Denmark)

    Goranovic, Goran

    device and the cascade EO-pump, discovery of how to pump non-polar liquids by electroosmosis, theory of clogging pressures of large bubbles in microchannel contractions, and a theoretical analysis of the stability conditions for the interface between two different dielectric liquids under influence...... of external electric fields. A significant effort has been devoted to the creation of a new group at MIC, the Microfluidcs Theory and Simulation Group (MIFTS). During the first year of this PhD-study, simulation of lab-on-a-chip systems was the main topic. Later, as students were attracted to the group...... the activities expanded to include the theoretical studies. At present MIFTS consists of two postdocs, four PhD students and a number of undergraduate students, under the leadership of prof. Henrik Bruus....

  19. Fluid shut-down system for a nuclear reactor

    International Nuclear Information System (INIS)

    Barclay, F.W.; Frey, J.R.; Wilson, J.N.; Besant, R.W.


    A nuclear reactor shut-down system is described which comprises a fluidic vortex valve for releasably maintaining a liquid neutron poison outside of the reactor core, the poison being contained by a reservoir and biased by pressure for flow into poison tubes within the reactor. The upper ends of the poison tubes communicate with the supply port of the vortex valve. A continuous gas flow into the control port maintains normal controlled operation. Shut-down is effected by interruption of the control input. One embodiment comprises three groups of poison tubes and one vortex valve associated with each group wherein shut-down is effected by poison release in two out of the three groups. Preferably, each vortex valve comprises three control ports which operate on a ''voting'' or two-out-of-three basis. (Official Gazette)

  20. The Erosion of Academic Freedom (United States)

    Ledoux, Michael W.; Marshall, Thomas; McHenry, Nadine


    This article originated from a single question: do the restrictions that various accrediting agencies place on teacher educators limit, or entirely eliminate, academic freedom? Considering that question makes it apparent the problem is much broader than academic freedom. The issue has two foci: personal identity and the impact of market…

  1. Experiences of Using MATLAB/Simulink in Simulation and Control of Fluid Power Systems

    DEFF Research Database (Denmark)

    Zhou, Jianjun; Conrad, Finn; Sørensen, Torben


    MATLAB and Simulink are widely used as primary software tools in teaching and research around the word. This paper presents our experiences of using MATLAB/Simulink in simulation and control of fluid power systems. The application concerned mainly in this paper is a hydraulic test robot, shown...

  2. Research Summary 3-D Computational Fluid Dynamics (CFD) Model Of The Human Respiratory System (United States)

    The U.S. EPA’s Office of Research and Development (ORD) has developed a 3-D computational fluid dynamics (CFD) model of the human respiratory system that allows for the simulation of particulate based contaminant deposition and clearance, while being adaptable for age, ethn...

  3. Fluid-conveying flexible pipes modeled by large-deflection finite elements in multibody systems

    NARCIS (Netherlands)

    Meijaard, Jacob Philippus


    The modeling and simulation of flexible multibody systems containing fluid-conveying pipes are considered. It is assumed that the mass-flow rate is prescribed and constant and the pipe cross section is piecewise uniform. An existing beam element capable of handling large motions is modified to

  4. Cerebrospinal fluid pleocytosis in infectious and noninfectious central nervous system disease

    DEFF Research Database (Denmark)

    Baunbæk Egelund, Gertrud; Ertner, Gideon; Langholz Kristensen, Kristina


    Cerebrospinal fluid (CSF) analysis is the most important tool for assessing central nervous system (CNS) disease. An elevated CSF leukocyte count rarely provides the final diagnosis, but is almost always an indicator of inflammation within the CNS.The present study investigated the variety...

  5. Pressure Feedback in Fluid Power Systems--Active Damping Explained and Exemplified

    DEFF Research Database (Denmark)

    Pedersen, Henrik Clemmensen; Andersen, Torben O.


    Fluid power systems are inherently nonlinear and typically suffer from very poor damping. Despite these characteristics, it is not uncommon that traditional linear type controllers are applied. This typically results in conservative adjustment of the controllers, or when more advanced controllers...

  6. Computerized Decision Support System Improves Fluid Resuscitation Outcomes Following Severe Burns: An Original Study (United States)


    fluid volume for overweight patients over 80 kg (25). CDSS deployment consisted of a dual- screen computer system running the Java run-time environment...a fiber optic bronchoscopy test. 2034 Crit Care Med 2011 Vol. 39, No. 9 Ratio comparisons resulted in CDSS patients also having lower mL/kg and mL

  7. RELAP5 two-phase fluid model and numerical scheme for economic LWR system simulation

    International Nuclear Information System (INIS)

    Ransom, V.H.; Wagner, R.J.; Trapp, J.A.


    The RELAP5 two-phase fluid model and the associated numerical scheme are summarized. The experience accrued in development of a fast running light water reactor system transient analysis code is reviewed and example of the code application are given

  8. Evaluation of Computational Fluid Dynamics and Coupled Fluid-Solid Modeling for a Direct Transfer Preswirl System. (United States)

    Javiya, Umesh; Chew, John; Hills, Nick; Dullenkopf, Klaus; Scanlon, Timothy


    The prediction of the preswirl cooling air delivery and disk metal temperature are important for the cooling system performance and the rotor disk thermal stresses and life assessment. In this paper, standalone 3D steady and unsteady computation fluid dynamics (CFD), and coupled FE-CFD calculations are presented for prediction of these temperatures. CFD results are compared with previous measurements from a direct transfer preswirl test rig. The predicted cooling air temperatures agree well with the measurement, but the nozzle discharge coefficients are under predicted. Results from the coupled FE-CFD analyses are compared directly with thermocouple temperature measurements and with heat transfer coefficients on the rotor disk previously obtained from a rotor disk heat conduction solution. Considering the modeling limitations, the coupled approach predicted the solid metal temperatures well. Heat transfer coefficients on the rotor disk from CFD show some effect of the temperature variations on the heat transfer coefficients. Reasonable agreement is obtained with values deduced from the previous heat conduction solution.

  9. Microfluidic valve array control system integrating a fluid demultiplexer circuit

    International Nuclear Information System (INIS)

    Kawai, Kentaro; Shoji, Shuichi; Arima, Kenta; Morita, Mizuho


    This paper proposes an efficient control method for the large-scale integration of microvalves in microfluidic systems. The proposed method can control 2 n individual microvalves with 2n + 2 control lines (where n is an integer). The on-chip valves are closed by applying pressure to a control line, similar to conventional pneumatic microvalves. Another control line closes gate valves between the control line to the on-chip valves and the on-chip valves themselves, to preserve the state of the on-chip valves. The remaining control lines select an activated gate valve. While the addressed gate valve is selected by the other control lines, the corresponding on-chip valve is actuated by applying input pressure to the control line to the on-chip valves. Using this method would substantially reduce the number of world-to-chip connectors and off-chip valve controllers. Experiments conducted using a fabricated 2 8 microvalve array device, comprising 256 individual on-chip valves controlled with 18 (2   ×   8 + 2) control lines, yielded switching speeds for the selected on-chip valve under 90 ms. (paper)

  10. TH-AB-202-12: The First Clinical Implementation of a Real-Time Six Degree of Freedom Tracking System During Radiation Therapy

    International Nuclear Information System (INIS)

    Nguyen, D; Kim, J; O’Brien, R; Huang, C; Keall, P; Booth, J; Greer, P; Martin, J; Legge, K; Poulsen, P


    Purpose: In current practice, imaging is typically performed prior to treatment; the cancer target motion during treatment is unknown. We present the first clinical implementation of real time Kilovoltage Intrafraction Monitoring (KIM) system which tracks the cancer target translational and rotational motions during treatment. Methods: KIM technology: KIM estimates the 3D position of the target tumour based on segmented 2D positions of the three implanted fiducials in each of the kV images (125 kV, 10 mA at 11 fps) taken continuously during the treatment arc. The 2D-3D target estimation is based on a probability distribution function, obtained during pre-treatment CBCT. Rotations about each axis with the centroid of the markers as the pivot were calculated using the iterative closest point algorithm in real time. Patient: A patient with prostate adenocarcinoma undergoing stereotactic body radiotherapy (SBRT) with 36.25 Gy delivered in 5 fractions (Varian TrueBeam, 6X, VMAT) was enrolled in the study. The trial complies with Australian ethical and regulatory standards. Results: Of the 5 fractions of treatment the patient received, KIM was utilised successfully in 4 fractions with 3 couch shifts due to large persistent prostate movements (>2mm for more than 5 seconds). KIM translational accuracy and precision in comparison with post treatment kV-MV triangulation are 0.28±0.59 mm, −0.19±0.25 mm and 0.23±0.69 mm in the Left-Right, Superior-Inferior and Anterior-Posterior directions, respectively. KIM rotational accuracy as compared with triangulation is: 0.429°±2.22°, −0.44°±4.7° and 0.06°±1.08° in the roll, pitch and yaw direction, respectively. Conclusion: The first six degree of freedom KIM system was successfully implemented clinically. The presented KIM system has sub-millimeters accuracy and precision in all three translational axes, and less than 1° of mean error in all three rotational axes. Acknowledgement: This work is supported by Cancer

  11. DNA - An integrated open-source optimization platform for thermo-fluid systems

    DEFF Research Database (Denmark)

    Pierobon, Leonardo; Wronski, Jorrit; Elmegaard, Brian


    of an air bottoming cycle unit recuperating the exhaust heat from an offshore power system. Subsequently, the control of a compressed air energy storage plant is modelled by interfacing with Matlab. Both cases take advantage of CoolProp’s table-based property interpolation scheme...... 110 fluids by interfacing CoolProp, a high-accuracy open-source property package for pure and pseudo-pure fluids, as well as humid air. Furthermore, the use as time integrator for other tools is demonstrated. The new features are unveiled in two case studies. The first example covers the optimization...

  12. Fluid-driven cracks and backflow in a multi-crack system (United States)

    Smiddy, Samuel; Lai, Ching-Yao; Stone, Howard


    We design a two-crack experiment to study the effects of natural fractures on hydraulic fractures. Instead of a single layer elastic matrix, we inject liquid into a multi-layered elastic matrix. A similar system has been used to study geological processes such as dike-sill formations. In our experiments, pressurized fluid fractures the matrix and pressures are quantified based on laser imaging of particle displacement. First, we report the opening of the cracks and subsequently, the direction of the fluid reverses upon release of injection pressure, driven by the elastic relaxation of the gelatin. The volume remaining in the gelatin matrix is measured as a function of time for different gelatin Young's moduli and fluid viscosities. We explain our results with scaling arguments.

  13. System and technique for characterizing fluids using ultrasonic diffraction grating spectroscopy (United States)

    Greenwood, Margaret S [Richland, WA


    A system for determining property of multiphase fluids based on ultrasonic diffraction grating spectroscopy includes a diffraction grating on a solid in contact with the fluid. An interrogation device delivers ultrasound through the solid and a captures a reflection spectrum from the diffraction grating. The reflection spectrum exhibits peaks whose relative size depends on the properties of the various phases of the multiphase fluid. For example, for particles in a liquid, the peaks exhibit dependence on the particle size and the particle volume fraction. Where the exact relationship is know know a priori, data from different peaks of the same reflection spectrum or data from the peaks of different spectra obtained from different diffraction gratings can be used to resolve the size and volume fraction.

  14. Let Freedom Ring! Let Peace Reign! (United States)

    Moore, Mary Elizabeth Mullino


    True freedom and true peace are cousins, but they can only work together if the freedom of one people is seen in relation to the freedom of another. Struggles for freedom and peace can only enhance each other if the peace people seek is a robust harmony in which conflict is embraced and people are encouraged to imagine a far stronger freedom and…

  15. Academic Freedom: Its Nature, Extent and Value (United States)

    Barrow, Robin


    Academic freedom does not refer to freedom to engage in any speech act, but to freedom to hold any belief and espouse it in an appropriately academic manner. This freedom belongs to certain institutions, rather than to individuals, because of their academic nature. Academic freedom should be absolute, regardless of any offence it may on occasion…

  16. Experience of using heat citric acid disinfection method in central dialysis fluid delivery system. (United States)

    Sakuma, Koji; Uchiumi, Nobuko; Sato, Sumihiko; Aida, Nobuhiko; Ishimatsu, Taketo; Igoshi, Tadaaki; Kodama, Yoshihiro; Hotta, Hiroyuki


    We applied the heat citric acid disinfection method in the main part of the central dialysis fluid delivery system (MPCDDS), which consists of a multiple-patient dialysis fluid supply unit, dialysis console units, and dialysis fluid piping. This disinfection method has been used for single-patient dialysis machines, but this is the first trial in the MPCDDS. We examined, by points of safety and disinfection effect, whether this disinfection method is comparable to conventional disinfection methods in Japan. The conventional disinfection method is a combination of two disinfectants, sodium hypochlorite and acetic acid, used separately for protein removal and decalcification. Consequently, total microbial counts and endotoxin concentrations fully satisfied the microbiological requirements for standard dialysis fluid of ISO 11663. From our results and discussion, this heat citric acid disinfection method is proved to be safe and reliable for MPCDDS. However, to satisfy the microbiological requirements for ultrapure dialysis fluid, further consideration for this method in MPCDDS including the reverse osmosis device composition and piping is necessary.

  17. Fluid Characteristics in the Giant Quartz Reef System of the Bundelkhand Craton, India: Constraints from Fluid Inclusion Study (United States)

    Rout, D.; Panigrahi, M. K.; Pati, J. K.


    Giant quartz reefs are anomalous features indicating extensive mobilization of silica in the crust. Such reefs in the Abitibi belt, Canada and elsewhere are believed to be the result of activity of fluid of diverse sources on terrain boundaries. The Bundelkhand granitoid complex constituting a major part of the Bundelkhnad Craton in north-Central India is traversed by numerous such quartz reefs all across for a length of about 500 km. There are about 20 major reefs having dimensions of 35 to 40 km in length, 50 to 60 m in width standing out as prominent ridges in the region. Almost all are aligned parallel to each other in a sub-vertical to vertical manner following the NE-SW to NNE-SSW trend. Fluid inclusion petrography in quartz from these reefs reveal four types of inclusions viz. aqueous biphase (type-I), pure carbonic (type-II), aqueous carbonic (type-III) and polyphase (type-IV) inclusions. The type-I aqueous biphase inclusions are the dominant type in all the samples studied so far. Salinities calculated from temperature of melting of last ice (Tm) values are low to moderate, ranging from 0.18 to 18.19 wt% NaCl equivalents. Temperature of liquid-vapor homogenization (Th) values of these inclusions show a wide range from 101 ºC to 386 ºC (cluster around 150-250 ºC) essentially into liquid phase ruling out boiling during its course of evolution. Besides, aqueous Biphase inclusions, some data on pure CO2 inclusions furnish a near constant value of TmCO2 at -56.6 ºC in the Bundelkhand Craton indicating absence of CH4. Bivariate plot between Th and salinity suggest three possible water types which are controlling the overall activity of fluid in quartz reefs of Bundelkhand Craton viz. low-T low saline, high-T low saline and moderate-T and moderate saline. A low saline and CO2-bearing and higher temperature nature resembles a metamorphic fluid that may be a source for these giant quartz reefs. The low temperature low-salinity component could be a meteoric

  18. Linear stability analysis of parallel shear flows for an inviscid generalized two-dimensional fluid system

    International Nuclear Information System (INIS)

    Iwayama, T; Sueyoshi, M; Watanabe, T


    The linear stability of parallel shear flows for an inviscid generalized two-dimensional (2D) fluid system, the so-called α turbulence system, is studied. This system is characterized by the relation q = −( − Δ) α/2 ψ between the advected scalar q and the stream function ψ. Here, α is a real number not exceeding 3 and q is referred to as the generalized vorticity. In this study, a sufficient condition for linear stability of parallel shear flows is derived using the conservation of wave activity. A stability analysis is then performed for a sheet vortex that violates the stability condition. The instability of a sheet vortex in the 2D Euler system (α = 2) is referred to as a Kelvin–Helmholtz (KH) instability; such an instability for the generalized 2D fluid system is investigated for 0 3−α for 1 < α < 3, where k is the wavenumber of the perturbation. In contrast, for 0 < α ⩽ 1, the growth rate is infinite. In other words, a transition of the growth rate of the perturbation occurs at α = 1. A physical model for KH instability in the generalized 2D fluid system, which can explain the transition of the growth rate of the perturbation at α = 1, is proposed. (paper)

  19. Fully coupled thermal-mechanical-fluid flow model for nonliner geologic systems

    International Nuclear Information System (INIS)

    Hart, R.D.


    A single model is presented which describes fully coupled thermal-mechanical-fluid flow behavior of highly nonlinear, dynamic or quasistatic, porous geologic systems. The mathematical formulation for the model utilizes the continuum theory of mixtures to describe the multiphase nature of the system, and incremental linear constitutive theory to describe the path dependency of nonlinear material behavior. The model, incorporated in an explicit finite difference numerical procedure, was implemented in two different computer codes. A special-purpose one-dimensional code, SNEAKY, was written for initial validation of the coupling mechanisms and testing of the coupled model logic. A general purpose commercially available code, STEALTH, developed for modeling dynamic nonlinear thermomechanical processes, was modified to include fluid flow behavior and the coupling constitutive model. The fully explicit approach in the coupled calculation facilitated the inclusion of the coupling mechanisms and complex constitutive behavior. Analytical solutions pertaining to consolidation theory for soils, thermoelasticity for solids, and hydrothermal convection theory provided verification of stress and fluid flow, stress and conductive heat transfer, and heat transfer and fluid flow couplings, respectively, in the coupled model. A limited validation of the adequacy of the coupling constitutive assumptions was also performed by comparison with the physical response from two laboratory tests. Finally, the full potential of the coupled model is illustrated for geotechnical applications in energy-resource related areas. Examples in the areas of nuclear waste isolation and cut-and-fill mining are cited

  20. The College Student's Freedom of Expression (United States)

    Gibbs, Annette


    Discussion of means to ensure freedom of expression by college students. Areas of expression noted are student newspapers, lectures by off-campus speakers, freedom to assemble peaceably and freedom to associate. (EK)

  1. The role of fluid migration system in hydrocarbon accumulation in Maichen Sag, Beibuwan Basin (United States)

    Liu, Hongyu; Yang, Jinxiu; Wu, Feng; Chen, Wei; Liu, Qianqian


    Fluid migration system is of great significance for hydrocarbon accumulation, including the primary migration and secondary migration. In this paper, the fluid migration system is analysed in Maichen Sag using seismic, well logging and core data. Results show that many factors control the hydrocarbon migration process, including hydrocarbon generation and expulsion period from source rocks, microfractures developed in the source rocks, the connected permeable sand bodies, the vertical faults cutting into/through the source rocks and related fault activity period. The spatial and temporal combination of these factors formed an effective network for hydrocarbon expulsion and accumulation, leading to the hydrocarbon reservoir distribution at present. Generally, a better understanding of the hydrocarbon migration system can explain the present status of hydrocarbon distribution, and help select future target zones for oil and gas exploration.

  2. An optimal control method for fluid structure interaction systems via adjoint boundary pressure (United States)

    Chirco, L.; Da Vià, R.; Manservisi, S.


    In recent year, in spite of the computational complexity, Fluid-structure interaction (FSI) problems have been widely studied due to their applicability in science and engineering. Fluid-structure interaction systems consist of one or more solid structures that deform by interacting with a surrounding fluid flow. FSI simulations evaluate the tensional state of the mechanical component and take into account the effects of the solid deformations on the motion of the interior fluids. The inverse FSI problem can be described as the achievement of a certain objective by changing some design parameters such as forces, boundary conditions and geometrical domain shapes. In this paper we would like to study the inverse FSI problem by using an optimal control approach. In particular we propose a pressure boundary optimal control method based on Lagrangian multipliers and adjoint variables. The objective is the minimization of a solid domain displacement matching functional obtained by finding the optimal pressure on the inlet boundary. The optimality system is derived from the first order necessary conditions by taking the Fréchet derivatives of the Lagrangian with respect to all the variables involved. The optimal solution is then obtained through a standard steepest descent algorithm applied to the optimality system. The approach presented in this work is general and could be used to assess other objective functionals and controls. In order to support the proposed approach we perform a few numerical tests where the fluid pressure on the domain inlet controls the displacement that occurs in a well defined region of the solid domain.

  3. 76 FR 73022 - Agency Information Collection (Operation Enduring Freedom/Operation Iraqi Freedom Seriously... (United States)


    ... AFFAIRS Agency Information Collection (Operation Enduring Freedom/ Operation Iraqi Freedom Seriously... Enduring Freedom/Operation Iraqi Freedom Seriously Injured/Ill Service Member Veteran Worksheet, VA Form 21... Operation Enduring Freedom or Operation Iraqi Freedom service members who have at least six months remaining...

  4. Dynamic Analysis of Fluid – Structure Interaction of Axial Fan System

    Directory of Open Access Journals (Sweden)

    Assim Hameed Yousif


    Full Text Available Fluid-structure interaction method is performed to predict the dynamic characteristics of axial fan system. A fluid-structure interface physical environment method (monolithic method is used to couple the fluid flow solver with the structural solver. The integration of the three-dimensional Navier-Stokes equations is performed in the time Doman, simultaneously to the integration of the three dimensional structural model. The aerodynamic loads are transfer from the flow to structure and the coupling step is repeated within each time step, until the flow solution and the structural solution have converged to yield a coupled solution of the aeroelastic set of equations. Finite element method is applied to solve numerically the Navier-Stockes equations coupled with the structural equations The first ten eigenvalue (natural frequency, the first ten eigenvector (mode shape and effective stress for each part of a rotor system and complete system assembly are predicted. The validity of the predicted dynamic characteristics of duct fan system was confirmed experimentally by investigating geometrically similar fan system test rig. Good agreement of dynamic characteristics is observed between experimental and numerical results

  5. Development of Fluid and I and C Systems Design Technology for LMR

    International Nuclear Information System (INIS)

    Kim, Seong O; Sim, Y. S.; Choi, S. K.; Kim, E. K.; Wi, M. H.; Eho, J. H.; Hur, S.; Seong, S. H.; Kim, S. Y.; Jeon, W. D.


    The basic concept of fluid and I and C system of KALIMER-600 was developed and the computer codes required to materialize system concept were also implemented through the R and D program. Based on the analysis results of the design characteristics for the similar reactor types developed in a foreign country, the system design technologies with adoption of the innovative ideas were developed. With the development, expansion and reinforcement of the methodologies required according to the progress of development and design of the system and the experimental verification of the developed computer code, the excellent and innovative outcomes were produced

  6. Fluids engineering

    International Nuclear Information System (INIS)



    Fluids engineering has played an important role in many applications, from ancient flood control to the design of high-speed compact turbomachinery. New applications of fluids engineering, such as in high-technology materials processing, biotechnology, and advanced combustion systems, have kept up unwaining interest in the subject. More accurate and sophisticated computational and measurement techniques are also constantly being developed and refined. On a more fundamental level, nonlinear dynamics and chaotic behavior of fluid flow are no longer an intellectual curiosity and fluid engineers are increasingly interested in finding practical applications for these emerging sciences. Applications of fluid technology to new areas, as well as the need to improve the design and to enhance the flexibility and reliability of flow-related machines and devices will continue to spur interest in fluids engineering. The objectives of the present seminar were: to exchange current information on arts, science, and technology of fluids engineering; to promote scientific cooperation between the fluids engineering communities of both nations, and to provide an opportunity for the participants and their colleagues to explore possible joint research programs in topics of high priority and mutual interest to both countries. The Seminar provided an excellent forum for reviewing the current state and future needs of fluids engineering for the two nations. With the Seminar ear-marking the first formal scientific exchange between Korea and the United States in the area of fluids engineering, the scope was deliberately left broad and general

  7. A study of matching fluid loss in a biomedical microwave tomography system. (United States)

    Gilmore, Colin; Zakaria, Amer; LoVetri, Joe; Pistorius, Stephen


    Effective imaging of human tissue with microwave tomography systems requires a matching fluid to reduce the wave reflections at the tissue boundary. Further, in order to match the idealized mathematical model used for imaging with the complicated physical measurement environment, loss must be added to the matching fluid. Both too little and too much loss result in low-quality images, but due to the nonlinear nature of the imaging problem, the exact nature of loss-to-image quality cannot be predicted a priori. Possible optimal loss levels include a single, highly sensitive value, or a broad range of acceptable losses. Herein, the authors outline a process of determining an appropriate level of loss inside the matching fluid and attempt to determine the bounds for which the images are the highest quality. Our biomedical microwave tomography system is designed for 2D limb imaging, operating from 0.8 to 1.2 GHz. Our matching fluid consists of deionized water with various levels of loss introduced by the addition of table salt. Using two homogeneous tissue-mimicking phantoms, and eight different matching fluids of varying salt concentrations, the authors introduce quantitative image quality metrics based on L-norms, mean values, and standard deviations to test the tomography system and assess image quality. Images are generated with a balanced multiplicative regularized contrast source inversion algorithm. The authors further generate images of a human forearm which may be analyzed qualitatively. The image metrics for the phantoms support the claim that the worst images occur at the extremes of high and low salt concentrations. Importantly, the image metrics show that there exists a broad range of salt concentrations that result in high-quality images, not a single optimal value. In particular, 2.5-4.5 g of table salt per liter of deionized water provide the best reconstruction quality for simple phantoms. The authors argue that qualitatively, the human forearm data

  8. Scientific Freedom and Human Rights (United States)

    Munoz, Elisa


    As part of her ongoing work monitoring issues at the intersection of science and human rights, Ms. Munoz has highlighted violations of academic freedom in Serbia and Iran, the denial of visas and travel licenses to U.S. and Cuban scientists, interference with scientific freedom in Brazil, Mexico, Russia, and the Ukraine, the use of organs from executed prisoners in China, legislation jeopardizing women's health in Iran, and the closure of centers for the treatment of torture survivors in Turkey. Such violations contravene international human rights principles listed in the Universal Declaration of Human Rights and other international human rights covenants. Ms. Munoz will describe current violations of scientific freedom and the relevant international principles on which these freedoms rest.

  9. Fluid-structure interaction in non-rigid pipeline systems - large scale validation experiments

    International Nuclear Information System (INIS)

    Heinsbroek, A.G.T.J.; Kruisbrink, A.C.H.


    The fluid-structure interaction computer code FLUSTRIN, developed by DELFT HYDRAULICS, enables the user to determine dynamic fluid pressures, structural stresses and displacements in a liquid-filled pipeline system under transient conditions. As such, the code is a useful tool to process and mechanical engineers in the safe design and operation of pipeline systems in nuclear power plants. To validate FLUSTRIN, experiments have been performed in a large scale 3D test facility. The test facility consists of a flexible pipeline system which is suspended by wires, bearings and anchors. Pressure surges, which excite the system, are generated by a fast acting shut-off valve. Dynamic pressures, structural displacements and strains (in total 70 signals) have been measured under well determined initial and boundary conditions. The experiments have been simulated with FLUSTRIN, which solves the acoustic equations using the method of characteristics (fluid) and the finite element method (structure). The agreement between experiments and simulations is shown to be good: frequencies, amplitudes and wave phenomena are well predicted by the numerical simulations. It is demonstrated that an uncoupled water hammer computation would render unreliable and useless results. (author)

  10. Freedom: A Promise of Possibility. (United States)

    Bunkers, Sandra Schmidt


    The idea of freedom as a promise of possibility is explored in this column. The core concepts from a research study on considering tomorrow (Bunkers, 1998) coupled with humanbecoming community change processes (Parse, 2003) are used to illuminate this notion. The importance of intentionality in human freedom is discussed from both a human science and a natural science perspective. © The Author(s) 2015.

  11. A fully coupled thermal-mechanical-fluid flow model for nonlinear geologic systems (United States)

    Hart, R. D.


    A single model is presented which describes fully coupled thermal-mechanical-fluid flow behavior of highly nonlinear, dynamic or quasistatic, porous geologic systems. The mathematical formulation for the model utilizes the continuum theory of mixtures to describe the multiphase nature of the system, and incremental linear constitutive theory to describe the path dependency of nonlinear material behavior. The model, incorporated in an explicit finite difference numerical procedure, was implemented in two different computer codes. A special-purpose one-dimensional code, SNEAKY, was written for initial validation of the coupling mechanisms and testing of the coupled model logic. A general purpose commercially available code, STEALTH, developed for modeling dynamic nonlinear thermomechanical processes, was modified to include fluid flow behavior and the coupling constitutive model. The fully explicit approach in the coupled calculation facilitated the inclusion of the coupling mechanisms and complex constitutive behavior.

  12. Computational fluid dynamics simulations of flow and concentration polarization in forward osmosis membrane systems

    DEFF Research Database (Denmark)

    Gruber, M.F.; Johnson, C.J.; Tang, C.Y.


    Forward osmosis is an osmotically driven membrane separation process that relies on the utilization of a large osmotic pressure differential generated across a semi-permeable membrane. In recent years forward osmosis has shown great promise in the areas of wastewater treatment, seawater...... the understanding of membrane systems, models that can accurately encapsulate all significant physical processes occurring in the systems are required. The present study demonstrates a computational fluid dynamics (CFD) model capable of simulating forward osmosis systems with asymmetric membranes. The model...

  13. Application of Modelling and Simulation in Mechatronics and Fluid Power System Design - Education and Research

    DEFF Research Database (Denmark)

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


    The development within the engineering industry is ever more in the direction of an integration of electronics both on the component level and system level. This implies improved and more intelligentcomponents with increased funtionality at the same time as the variant creation is made in the ele...... and control can be useful in analysis, synthesis, design and application of mechatronic systems with fluid power actuation. The focus is on system aspects and describes several projects from education and research that utilises the mentioned methods and techniques....

  14. Computer Software for Design, Analysis and Control of Fluid Power Systems

    DEFF Research Database (Denmark)

    Conrad, Finn; Sørensen, Torben; Grahl-Madsen, Mads


    This Deliverable presents contributions from SWING's Task 2.3 Analysis of available software solutions. The Deliverable has focus on the results from this analysis having in mind the task objectives·to carry out a thorough analysis of the state-of the-art solutions for fluid power systems modelli...... and modelling IT tools in the implementation planning (WP3) and pilot implementation (WP4), in particular training programme for key people in the individual SME and/or cluster....

  15. Research into the Physiology of Cerebrospinal Fluid Reaches a New Horizon: Intimate Exchange between Cerebrospinal Fluid and Interstitial Fluid May Contribute to Maintenance of Homeostasis in the Central Nervous System. (United States)

    Matsumae, Mitsunori; Sato, Osamu; Hirayama, Akihiro; Hayashi, Naokazu; Takizawa, Ken; Atsumi, Hideki; Sorimachi, Takatoshi


    Cerebrospinal fluid (CSF) plays an essential role in maintaining the homeostasis of the central nervous system. The functions of CSF include: (1) buoyancy of the brain, spinal cord, and nerves; (2) volume adjustment in the cranial cavity; (3) nutrient transport; (4) protein or peptide transport; (5) brain volume regulation through osmoregulation; (6) buffering effect against external forces; (7) signal transduction; (8) drug transport; (9) immune system control; (10) elimination of metabolites and unnecessary substances; and finally (11) cooling of heat generated by neural activity. For CSF to fully mediate these functions, fluid-like movement in the ventricles and subarachnoid space is necessary. Furthermore, the relationship between the behaviors of CSF and interstitial fluid in the brain and spinal cord is important. In this review, we will present classical studies on CSF circulation from its discovery over 2,000 years ago, and will subsequently introduce functions that were recently discovered such as CSF production and absorption, water molecule movement in the interstitial space, exchange between interstitial fluid and CSF, and drainage of CSF and interstitial fluid into both the venous and the lymphatic systems. Finally, we will summarize future challenges in research. This review includes articles published up to February 2016.

  16. Investigation and Optimisation of a Discrete Fluid Power PTO-system for Wave Energy Converters

    DEFF Research Database (Denmark)

    Hansen, Anders Hedegaard

    recently focused research on improving the power take off (PTO) system converting the mechanical motion of the floats into electricity. This has brought attention to discrete fluid power (DFP) technology, especially secondary controlled common pressure rail systems. A novel discrete PTO-system has been...... investigation show how the wave climate naturally influence the optimal system configuration yielding maximal energy output, and how one may choose the system configuration based on the installation site. The switching manifold is the control element of the secondary controlled force system. The force....... Involvement in designing, installation and control of a full scale PTO test-bench has been under-taken parallel to the theoretical work. Preliminary force switching tests have been conducted to investigate the influence of valve switching time on the dynamic behaviour of the PTO-system. The results...

  17. Space Station Freedom - What if...? (United States)

    Grey, Jerry


    The use of novel structural designs and the Energia launch system of the Commonwealth of Independent States for the Space Station Freedom (SSF) program is evaluated by means of a concept analysis. The analysis assumes that: (1) Energia is used for all cargo and logistics resupply missions; (2) the shuttles are launched from the U.S.; and (3) an eight-person assured crew return vehicle is available. This launch/supply scenario reduces the deployment risk from 30 launches to a total of only eight launches reducing the cost by about 15 billion U.S. dollars. The scenario also significantly increases the expected habitable and storage volumes and decreases the deployment time by three years over previous scenarios. The specific payloads are given for Energia launches emphasizing a proposed design for the common module cluster that incorporates direct structural attachment to the truss at midspan. The design is shown to facilitate the accommodation of additional service hangars and to provide a more efficient program for spacecraft habitable space.

  18. On conditioned and directed freedom of contrats between business entity

    Directory of Open Access Journals (Sweden)

    Đurđević Marko


    Full Text Available The term conditioned freedom of contracts appeared in our legal theory before the adoption of the Obligations Relations Act, whereas the term directed freedom of contracts occurred after the Act's entry into force. Both terms were used to signify transformation of freedom of con tracts within the legal system based on ideology of socialism, social ownership of the means of production and government ruled economy and, afterwards, 'coordinated economy'. Conditioned freedom of contracts originated from the right to use the means of production in social ownership. This right, which belonged to social (state-owned companies, consisted of two components. The first, public-law component conditioned the second, private law component, by means of norms in individual administrative acts and administrative regulations. As these norms were an expression of state power, they make the contract subordinate: individual administrative act is a condition for the conclusion of contract, and administrative regulations for its validity. Directed freedom of contracts is freedom of making contracts directed by economic order established by the Constitution, systemic laws, and partially by the norms of the basic principles of the Obligations Relations Act which are related to social companies. As regards freedom of contracts it can be said that even today it is directed by legal principles and norms of economic-legal public policy through which the state interferes in business enterprises.

  19. Application of fluid flow systems analysis to reconstruct the post-Carboniferous hydrogeohistory of the onshore and offshore Netherlands

    NARCIS (Netherlands)

    Verweij, J.M.


    The reconstruction of the post-Carboniferous hydrogeohistory of the onshore and offshore Netherlands is part of an ongoing TNO project on fluid flow systems analysis on geological timescales. The scope of the project is to assess the present-day hydrogeological and fluid flow conditions of the

  20. Copper-arsenic decoupling in an active geothermal system: A link between pyrite and fluid composition (United States)

    Tardani, Daniele; Reich, Martin; Deditius, Artur P.; Chryssoulis, Stephen; Sánchez-Alfaro, Pablo; Wrage, Jackie; Roberts, Malcolm P.


    Over the past few decades several studies have reported that pyrite hosts appreciable amounts of trace elements which commonly occur forming complex zoning patterns within a single mineral grain. These chemical zonations in pyrite have been recognized in a variety of hydrothermal ore deposit types (e.g., porphyry Cu-Mo-Au, epithermal Au deposits, iron oxide-copper-gold, Carlin-type and Archean lode Au deposits, among others), showing, in some cases, marked oscillatory alternation of metals and metalloids in pyrite growth zones (e.g., of Cu-rich, As-(Au, Ag)-depleted zones and As-(Au, Ag)-rich, Cu-depleted zones). This decoupled geochemical behavior of Cu and As has been interpreted as a result of chemical changes in ore-forming fluids, although direct evidence connecting fluctuations in hydrothermal fluid composition with metal partitioning into pyrite growth zones is still lacking. In this study, we report a comprehensive trace element database of pyrite from the Tolhuaca Geothermal System (TGS) in southern Chile, a young and active hydrothermal system where fewer pyrite growth rims and mineralization events are present and the reservoir fluid (i.e. ore-forming fluid) is accessible. We combined the high-spatial resolution and X-ray mapping capabilities of electron microprobe analysis (EMPA) with low detection limits and depth-profiling capacity of secondary-ion mass spectrometry (SIMS) in a suite of pyrite samples retrieved from a ∼1 km drill hole that crosses the argillic (20-450 m) and propylitic (650-1000 m) alteration zones of the geothermal system. We show that the concentrations of precious metals (e.g., Au, Ag), metalloids (e.g., As, Sb, Se, Te), and base and heavy metals (e.g., Cu, Co, Ni, Pb) in pyrite at the TGS are significant. Among the elements analyzed, As and Cu are the most abundant with concentrations that vary from sub-ppm levels to a few wt.% (i.e., up to ∼5 wt.% As, ∼1.5 wt.% Cu). Detailed wavelength-dispersive spectrometry (WDS) X

  1. Acceleration of coupled granular flow and fluid flow simulations in pebble bed energy systems

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yanheng, E-mail: [Department of Mechanical, Aerospace, and Nuclear Engineering, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY (United States); Ji, Wei, E-mail: [Department of Mechanical, Aerospace, and Nuclear Engineering, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY (United States)


    Highlights: ► Fast simulation of coupled pebble flow and coolant flow in PBR systems is studied. ► Dimension reduction based on axisymmetric geometry shows significant speedup. ► Relaxation of coupling frequency is investigated and an optimal range is determined. ► A total of 80% efficiency increase is achieved by the two fast strategies. ► Fast strategies can be applied to simulating other general fluidized bed systems. -- Abstract: Fast and accurate approaches to simulating the coupled particle flow and fluid flow are of importance to the analysis of large particle-fluid systems. This is especially needed when one tries to simulate pebble flow and coolant flow in Pebble Bed Reactor (PBR) energy systems on a routine basis. As one of the Generation IV designs, the PBR design is a promising nuclear energy system with high fuel performance and inherent safety. A typical PBR core can be modeled as a particle-fluid system with strong interactions among pebbles, coolants and reactor walls. In previous works, the coupled Discrete Element Method (DEM)-Computational Fluid Dynamics (CFD) approach has been investigated and applied to modeling PBR systems. However, the DEM-CFD approach is computationally expensive due to large amounts of pebbles in PBR systems. This greatly restricts the PBR analysis for the real time prediction and inclusion of more physics. In this work, based on the symmetry of the PBR geometry and the slow motion characteristics of the pebble flow, two acceleration strategies are proposed. First, a simplified 3D-DEM/2D-CFD approach is proposed to speed up the DEM-CFD simulation without loss of accuracy. Pebble flow is simulated by a full 3D DEM, while the coolant flow field is calculated with a 2D CFD simulation by averaging variables along the annular direction in the cylindrical and annular geometries. Second, based on the slow motion of pebble flow, the impact of the coupling frequency on the computation accuracy and efficiency is

  2. Acceleration of coupled granular flow and fluid flow simulations in pebble bed energy systems

    International Nuclear Information System (INIS)

    Li, Yanheng; Ji, Wei


    Highlights: ► Fast simulation of coupled pebble flow and coolant flow in PBR systems is studied. ► Dimension reduction based on axisymmetric geometry shows significant speedup. ► Relaxation of coupling frequency is investigated and an optimal range is determined. ► A total of 80% efficiency increase is achieved by the two fast strategies. ► Fast strategies can be applied to simulating other general fluidized bed systems. -- Abstract: Fast and accurate approaches to simulating the coupled particle flow and fluid flow are of importance to the analysis of large particle-fluid systems. This is especially needed when one tries to simulate pebble flow and coolant flow in Pebble Bed Reactor (PBR) energy systems on a routine basis. As one of the Generation IV designs, the PBR design is a promising nuclear energy system with high fuel performance and inherent safety. A typical PBR core can be modeled as a particle-fluid system with strong interactions among pebbles, coolants and reactor walls. In previous works, the coupled Discrete Element Method (DEM)-Computational Fluid Dynamics (CFD) approach has been investigated and applied to modeling PBR systems. However, the DEM-CFD approach is computationally expensive due to large amounts of pebbles in PBR systems. This greatly restricts the PBR analysis for the real time prediction and inclusion of more physics. In this work, based on the symmetry of the PBR geometry and the slow motion characteristics of the pebble flow, two acceleration strategies are proposed. First, a simplified 3D-DEM/2D-CFD approach is proposed to speed up the DEM-CFD simulation without loss of accuracy. Pebble flow is simulated by a full 3D DEM, while the coolant flow field is calculated with a 2D CFD simulation by averaging variables along the annular direction in the cylindrical and annular geometries. Second, based on the slow motion of pebble flow, the impact of the coupling frequency on the computation accuracy and efficiency is

  3. Modular concept for fluid handling systems: a demonstrator micro analysis system

    NARCIS (Netherlands)

    Lammerink, Theodorus S.J.; Spiering, V.L.; Spiering, V.L.; Elwenspoek, Michael Curt; Fluitman, J.H.J.; van den Berg, Albert


    A modular planar concept for fluid handling microsystems is presented. The concept is based on a planar Mixed Circuit Board with electrical and fluidic interconnections acting as a substrate for sensor and actuator modules. Several modules realised within this concept are presented, and the design

  4. Semiclassical approach to model quantum fluids using the statistical associating fluid theory for systems with potentials of variable range. (United States)

    Trejos, Víctor M; Gil-Villegas, Alejandro


    Thermodynamic properties of quantum fluids are described using an extended version of the statistical associating fluid theory for potentials of variable range (SAFT-VR) that takes into account quantum corrections to the Helmholtz free energy A, based on the Wentzel-Kramers-Brillouin approximation. We present the theoretical background of this approach (SAFT-VRQ), considering two different cases depending on the continuous or discontinuous nature of the particles pair interaction. For the case of continuous potentials, we demonstrate that the standard Wigner-Kirkwood theory for quantum fluids can be derived from the de Broglie-Bohm formalism for quantum mechanics that can be incorporated within the Barker and Henderson perturbation theory for liquids in a straightforward way. When the particles interact via a discontinuous pair potential, the SAFT-VR method can be combined with the perturbation theory developed by Singh and Sinha [J. Chem. Phys. 67, 3645 (1977); and ibid. 68, 562 (1978)]. We present an analytical expression for the first-order quantum perturbation term for a square-well potential, and the theory is applied to model thermodynamic properties of hydrogen, deuterium, neon, and helium-4. Vapor-liquid equilibrium, liquid and vapor densities, isochoric and isobaric heat capacities, Joule-Thomson coefficients and inversion curves are predicted accurately with respect to experimental data. We find that quantum corrections are important for the global behavior of properties of these fluids and not only for the low-temperature regime. Predictions obtained for hydrogen compare very favorably with respect to cubic equations of state.

  5. Star polymers: study of fluid-fluid transitions in a system with a repulsive ultrasoft-core

    CERN Document Server

    Verso, F L; Reatto, L


    We study a model for star polymers in solution which, in addition to the ultrasoft repulsive interaction of entropic origin, has an attractive interpolymer interaction at longer range. This attraction can arise from a suitable tuning of the solvent and solute properties. For this model we study the phase diagram using mean-field theory and two fluid-state theories, the modified hypernetted chain (MHNC) integral equation and the hierarchical reference theory, and we explore star polymers with a different number of arms f (f = 12, 24, 32, 40). All three theories give the same topology for the phase diagram in the presence of attraction. When the strength of the interaction is strong enough a fluid-fluid phase transition appears but the coexistence curve in the density-temperature (strength of attraction) bifurcates at a triple point into two lines of coexistence terminating at two critical points. This peculiar phase behaviour is related to the unusual form of the repulsive contribution V sub r sub e sub p (r):...

  6. Near-surface gravity actuated pipe (GAP{sup TM}) system for Brazilian deepwater fluid transfer

    Energy Technology Data Exchange (ETDEWEB)

    Fromage, Lionel; Brown, Paul A. [SBM Offshore (Monaco)


    The recent discovery of new deep water and ultra-deep water oil and gas fields offshore Brazil, including pre-salt reservoirs, has become a focal point for field development Operators and Contractors. The aggressive nature of fluids (sour, high density) in combination with deeper waters implies potential flow assurance issues. These issues challenge riser and pipeline technology to find cost effective solutions for hydrocarbon fluid transfer in field development scenarios involving phased tied-back. The near-surface GAP{sup TM}, system (Gravity Actuated Pipe{sup TM}), which has been in operation for more than two years on the Kikeh field offshore Malaysia in 1325 m of water between a Dry Tree Unit (SPAR) and a turret-moored FPSO, is considered to meet these challenges since such a product is quasi independent of water depth and takes advantage of being near surface to optimize flow assurance. Furthermore the GAP{sup TM} has undergone technical upgrades when compared to the Kikeh project in order to make it suitable for the more hostile met ocean conditions offshore Brazil. This paper presents the design features, the construction and assembly plans in Brazil and the offshore installation of a GAP fluid transfer system for operation in Brazilian deep waters. (author)

  7. Direct Numerical Simulation of Poly-dispersed Solid-Fluid Systems (United States)

    Essmann, Erich; Shui, Pei; Govindarajan, Rama; Popinet, Stephane; Valluri, Prashant


    The fluid dynamics of poly-dispersed solid - fluid systems are of great importance, particularly is the behaviour of methane clathrates slurries. In this work, a framework is being developed for the direct numerical simulation of these systems. We have extended the Gerris software package of (Popinet et al., 2003). In our solid solver, Gerris Immersed Solid Solver (GISS), to account for collisions we have implemented a novel contact model (Ness & Sun, 2016) for solid-solid interactions. A composite contact model is being used, in which each solid in the domain is divided into two regions. The outer region uses a Hookean repulsive and a lubrication force model to simulate contact. The inner region uses a constraint based contact model to ensure that the numerical overlap of the solids is not excessive. We have validated our methodology against published experimental data. Particularly, we compared the chaotic motion of an ellipsoidal solid in an ideal fluid (Aref, 1993) to that predicted by GISS and the settling behaviour of two colliding spheres of different densities (Zhao, 2003). The validated extensions will allow us to compare previous results from GISS to regimes in which solid-solid contact is important.

  8. Academic Freedom and the Diminished Subject (United States)

    Hayes, Dennis


    Discussions about freedom of speech and academic freedom today are about the limits to those freedoms. However, these discussions take place mostly in the higher education trade press and do not receive any serious attention from academics and educationalists. In this paper several key arguments for limiting academic freedom are identified,…

  9. [Imbalance of system of glutamin - glutamic acid in the placenta and amniotic fluid at placental insufficiency]. (United States)

    Pogorelova, T N; Gunko, V O; Linde, V A


    Metabolism of glutamine and glutamic acid has been investigated in the placenta and amniotic fluid under conditions of placental insufficiency. The development of placental insufficiency is characterized by the increased content of glutamic acid and a decrease of glutamine in both placenta and amniotic fluid. These changes changes were accompanied by changes in the activity of enzymes involved in the metabolism of these amino acids. There was a decrease in glutamate dehydrogenase activity and an increase in glutaminase activity with the simultaneous decrease of glutamine synthetase activity. The compensatory decrease in the activity of glutamine keto acid aminotransferase did not prevent a decrease in the glutamine level. The impairments in the system glutamic acid-glutamine were more pronounced during the development of premature labor.

  10. Fluid-solid transition in simple systems using density functional theory

    Energy Technology Data Exchange (ETDEWEB)

    Bharadwaj, Atul S.; Singh, Yashwant [Department of Physics, Banaras Hindu University, Varanasi-221 005 (India)


    A free energy functional for a crystal which contains both the symmetry-conserved and symmetry-broken parts of the direct pair correlation function has been used to investigate the fluid-solid transition in systems interacting via purely repulsive Weeks-Chandler-Anderson Lennard–Jones potential and the full Lennard–Jones potential. The results found for freezing parameters for the fluid-face centred cubic crystal transition are in very good agreement with simulation results. It is shown that although the contribution made by the symmetry broken part to the grand thermodynamic potential at the freezing point is small compared to that of the symmetry conserving part, its role is crucial in stabilizing the crystalline structure and on values of the freezing parameters.

  11. Remarks on Hierarchic Control for a Linearized Micropolar Fluids System in Moving Domains

    Energy Technology Data Exchange (ETDEWEB)

    Jesus, Isaías Pereira de, E-mail: [Universidade Federal do Piauí, Dpto. Matemática (Brazil)


    We study a Stackelberg strategy subject to the evolutionary linearized micropolar fluids equations in domains with moving boundaries, considering a Nash multi-objective equilibrium (non necessarily cooperative) for the “follower players” (as is called in the economy field) and an optimal problem for the leader player with approximate controllability objective. We will obtain the following main results: the existence and uniqueness of Nash equilibrium and its characterization, the approximate controllability of the linearized micropolar system with respect to the leader control and the existence and uniqueness of the Stackelberg–Nash problem, where the optimality system for the leader is given.

  12. Application of computational fluid dynamics and fluid structure interaction techniques for calculating the 3D transient flow of journal bearings coupled with rotor systems (United States)

    Li, Qiang; Yu, Guichang; Liu, Shulian; Zheng, Shuiying


    Journal bearings are important parts to keep the high dynamic performance of rotor machinery. Some methods have already been proposed to analysis the flow field of journal bearings, and in most of these methods simplified physical model and classic Reynolds equation are always applied. While the application of the general computational fluid dynamics (CFD)-fluid structure interaction (FSI) techniques is more beneficial for analysis of the fluid field in a journal bearing when more detailed solutions are needed. This paper deals with the quasi-coupling calculation of transient fluid dynamics of oil film in journal bearings and rotor dynamics with CFD-FSI techniques. The fluid dynamics of oil film is calculated by applying the so-called "dynamic mesh" technique. A new mesh movement approach is presented while the dynamic mesh models provided by FLUENT are not suitable for the transient oil flow in journal bearings. The proposed mesh movement approach is based on the structured mesh. When the journal moves, the movement distance of every grid in the flow field of bearing can be calculated, and then the update of the volume mesh can be handled automatically by user defined function (UDF). The journal displacement at each time step is obtained by solving the moving equations of the rotor-bearing system under the known oil film force condition. A case study is carried out to calculate the locus of the journal center and pressure distribution of the journal in order to prove the feasibility of this method. The calculating results indicate that the proposed method can predict the transient flow field of a journal bearing in a rotor-bearing system where more realistic models are involved. The presented calculation method provides a basis for studying the nonlinear dynamic behavior of a general rotor-bearing system.

  13. Kant, Freedom as Independence, and Democracy

    DEFF Research Database (Denmark)

    Rostbøll, Christian F.


    democracy. This freedom argument goes beyond freedom as moral autonomy and a libertarian idea of freedom as non-interference to a notion of freedom as a form of standing constituted by the public legal order. The trouble with other attempts to connect freedom and democracy is that they have operated......, but they have largely ignored its potential contribution to discussions of democracy. However, Kant’s approach to political philosophy can supply unique insights to the latter. His notion that freedom and the public legal order are co-constitutive can be developed into a freedom argument for constitutional...

  14. Numerical Modeling of Poroelastic-Fluid Systems Using High-Resolution Finite Volume Methods (United States)

    Lemoine, Grady

    Poroelasticity theory models the mechanics of porous, fluid-saturated, deformable solids. It was originally developed by Maurice Biot to model geophysical problems, such as seismic waves in oil reservoirs, but has also been applied to modeling living bone and other porous media. Poroelastic media often interact with fluids, such as in ocean bottom acoustics or propagation of waves from soft tissue into bone. This thesis describes the development and testing of high-resolution finite volume numerical methods, and simulation codes implementing these methods, for modeling systems of poroelastic media and fluids in two and three dimensions. These methods operate on both rectilinear grids and logically rectangular mapped grids. To allow the use of these methods, Biot's equations of poroelasticity are formulated as a first-order hyperbolic system with a source term; this source term is incorporated using operator splitting. Some modifications are required to the classical high-resolution finite volume method. Obtaining correct solutions at interfaces between poroelastic media and fluids requires a novel transverse propagation scheme and the removal of the classical second-order correction term at the interface, and in three dimensions a new wave limiting algorithm is also needed to correctly limit shear waves. The accuracy and convergence rates of the methods of this thesis are examined for a variety of analytical solutions, including simple plane waves, reflection and transmission of waves at an interface between different media, and scattering of acoustic waves by a poroelastic cylinder. Solutions are also computed for a variety of test problems from the computational poroelasticity literature, as well as some original test problems designed to mimic possible applications for the simulation code.

  15. [On freedom of scientific research]. (United States)

    Folkers, G


    Debates about science and, more specifically, about scientific research quickly bring up the question about its freedom. Science is readily blamed for technological disasters or criticized for nursing fantasies of omnipotence and commercial gain. This prompts the call for a restriction of its freedom. At the same time, society's demands on science are enormous, to the effect that science and technology have acquired the status of a deus-ex-machina: they are expected to furnish short-term, affordable, and convenient solutions to a wide range of problems, including issues of health, transportation, food and, more generally, a comfortable life. What kind of freedom is required to meet these expectations? Who is in a position to grant it? What does freedom for science mean and how is it linked to responsibility? The paper examines the current situation of freedom in scientific research and of its restrictions, many of which are mentally or economically conditioned. It calls for the involvement of an informed, self-confident bourgeoisie in research decisions and for the educational measures this necessitates. Finally, it demands a greater appreciation of education (rather than training) as the basis of social trust, and the recognition of continuous education as a productive investment of time and a crucial element in the employment of social goods.

  16. An energy-stable finite-difference scheme for the binary fluid-surfactant system (United States)

    Gu, Shuting; Zhang, Hui; Zhang, Zhengru


    We present an unconditionally energy stable finite-difference scheme for the binary fluid-surfactant system. The proposed method is based on the convex splitting of the energy functional with two variables. Here are two distinct features: (i) the convex splitting energy method is applied to energy functional with two variables, and (ii) the stability issue is related to the decay of the corresponding energy. The full discrete scheme leads to a decoupled system including a linear sub-system and a nonlinear sub-system. Algebraic multigrid and Newton-multigrid methods are adopted to solve the linear and nonlinear systems, respectively. Numerical experiments are shown to verify the stability of such a scheme.

  17. Human Freedom ``Emergence'' (United States)

    Newsome, William T.

    Whether free will is a reality is an increasingly urgent problem, both from a scientific and a social point of view. An ability to make judgments and take actions that are "free" in some meaningful sense would seem a prerequisite for the process of scientific reasoning and for our ability to behave morally. How are we to reconcile the "autonomy" of a reasoning intellect with our scientific conviction that all behavior is mediated by mechanistic interactions between cells of the central nervous system? It seems that answers will ultimately lie in a deeper understanding of emergent phenomena in complex systems. This will help enrich our impoverished standard notions of causation in physical systems.

  18. A Novel Approach for Modeling Chemical Reaction in Generalized Fluid System Simulation Program (United States)

    Sozen, Mehmet; Majumdar, Alok


    The Generalized Fluid System Simulation Program (GFSSP) is a computer code developed at NASA Marshall Space Flight Center for analyzing steady state and transient flow rates, pressures, temperatures, and concentrations in a complex flow network. The code, which performs system level simulation, can handle compressible and incompressible flows as well as phase change and mixture thermodynamics. Thermodynamic and thermophysical property programs, GASP, WASP and GASPAK provide the necessary data for fluids such as helium, methane, neon, nitrogen, carbon monoxide, oxygen, argon, carbon dioxide, fluorine, hydrogen, water, a hydrogen, isobutane, butane, deuterium, ethane, ethylene, hydrogen sulfide, krypton, propane, xenon, several refrigerants, nitrogen trifluoride and ammonia. The program which was developed out of need for an easy to use system level simulation tool for complex flow networks, has been used for the following purposes to name a few: Space Shuttle Main Engine (SSME) High Pressure Oxidizer Turbopump Secondary Flow Circuits, Axial Thrust Balance of the Fastrac Engine Turbopump, Pressurized Propellant Feed System for the Propulsion Test Article at Stennis Space Center, X-34 Main Propulsion System, X-33 Reaction Control System and Thermal Protection System, and International Space Station Environmental Control and Life Support System design. There has been an increasing demand for implementing a combustion simulation capability into GFSSP in order to increase its system level simulation capability of a liquid rocket propulsion system starting from the propellant tanks up to the thruster nozzle for spacecraft as well as launch vehicles. The present work was undertaken for addressing this need. The chemical equilibrium equations derived from the second law of thermodynamics and the energy conservation equation derived from the first law of thermodynamics are solved simultaneously by a Newton-Raphson method. The numerical scheme was implemented as a User

  19. Freedom of Expression in Distributed Networks

    Directory of Open Access Journals (Sweden)

    Ejvind Hansen


    Full Text Available This paper proposes the following question: Is it possible to transfer human rights like the freedom of expression – or at least to preserve the formal protections guarding speech acts from arbitrary suppression – in a post-national setting? The question arises as an urgent matter in the context of our global system of connected markets and distributed telecommunications networks – the Internet – since, as many academics and policy makers have noted, the two tend to undermine nationals boundaries, putting into question the power of individual states to continue function as the traditional legal and identity-generating entities of last resort.   If this analysis is reliable the dialectical union between the autonomous individual citizen and the legally regulated nation state is broken. In this paper I will draw the consequences of that supposed break, exploring the question of the extent to which it makes sense to accord “rights” – freedom of expression – to entities that are not classical autonomous humans, and to confer them by entities that no longer bear the marks of nation-state sovereignty. The question thus is: Is it possible to transfer the normative approach of the classic liberal nation states into a global system?   The paper explores this question through an elaboration of problems for the preservation of the human right to freedom of expression: On the one hand communication on the Internet is regulated by an immense legal body, but on the other hand, the machinery for enforcement controlled by this legal body is dependent on various agencies that don’t necessarily recognize its legitimacy. I will then explore whether a more technologically oriented approach could be a more fruitful approach in defining the actual limitations to freedom of expression in the new global system. My answer is that ultimately the control paradigm fails, because it is too clumsy at incorporating self-correcting measures. Thirdly, I

  20. Space Station Freedom cupola definition (United States)

    Weaver, Laurie A.; Lauger, John


    Following the realization that adequate Space Station Freedom viewing could not be achieved without breaking the plane of the modules, a conceptual design phase for the development of a cupola progressed from the idea of a small, bubble-type canopy to a much larger, two crewmember cupola. The evolving cupola conceptual designs were each evaluated against the requirements for providing a large field-of-view, a complete proximity control workstation with flexible and relocatable restraints, and sufficient volume for two, 95th percentile crewmembers to operate while still maintaining reasonable weight and size restrictions. As the SS Freedom program Preliminary Design Review draws closer, the cupola development phase shifts toward evaluation of viewing and operational capability. The appropriate balance of viewing, structures and operations must be achieved before the program can place confidence in a cupola design providing SS Freedom with a direct viewing workstation capable of supporting the great variety of tasks projected for the life of the station.

  1. Computational fluid dynamics simulation of pressure and velocity distribution inside Meniere’s diseased vestibular system (United States)

    Shamsuddin, N. F. H.; Isa, N. M.; Taib, I.; Mohammed, A. N.


    Meniere’s disease or known as endolymphatic hydrops is an incurable vestibular disorder of the inner ear. This is due to the excessive fluid build-up in the endolymphatic sac which causing the vestibular endolymphatic membrane to start stretching. Although this mechanism has been widely accepted as the likely mechanism of Meniere’s syndrome, the reason for its occurrence remains unclear. Thus, the aims of this study to investigate the critical parameters of fluid flow in membranous labyrinth that is influencing instability of vestibular system. In addition, to visualise the flow behaviour between a normal membranous labyrinth and dilated membranous labyrinth in Meniere’s disease in predicting instability of vestibular system. Three dimensional geometry of endolymphatic sac is obtained from Magnetic Resonance Images (MRI) and reconstructed using commercial software. As basis of comparison the two different model of endolymphatic sac is considered in this study which are normal membranous labyrinth for model I and dilated membranous labyrinth for model II. Computational fluid dynamics (CFD) method is used to analyse the behaviour of pressure and velocity flow in the endolymphatic sac. The comparison was made in terms of pressure distribution and velocity profile. The results show that the pressure for dilated membranous labyrinth is greater than normal membranous labyrinth. Due to abnormally pressure in the vestibular system, it leads to the increasing value of the velocity at dilated membranous labyrinth while at the normal membranous labyrinth the velocity values decreasing. As a conclusion by changing the parameters which is pressure and velocity can significantly affect to the instability of vestibular system for Meniere’s disease.

  2. Academic Freedom in Higher Education

    Directory of Open Access Journals (Sweden)



    Full Text Available In this study, the concept ‘academic freedom’ is discussed, its implications and value for the academics, institutions of higher education, and the society are focused, and a few suggestions for the Turkish higher education are made. Academic freedom is defined as the freedom of the academic staff to look for and to find the truth in their scientific field, to publish the findings, and to teach these findings to their students without any external intervention. The concept has gained a further definition with inclusion of research activities into academic freedom as part of the reform attempts started in the German higher education in the 19th century. Therefore, academic freedom is at the very core of the missions of the institutions of higher education; that is, teaching-learning and research. On the point of academic staff and their academic activities of the academic freedom, the subjects such as the aim of the course, choosing the teaching materials and textbooks, the lecturer, and the criteria for the measurement and evaluation of the course take place. And he point of research covers the aim of the study, academicians can’t be imposed the involve in an academic and artistic studies that conflict their values and beliefs; researchers should comply with codes of ethical principles and practices during the process of researching; and research outputs should be reported accurately and honestly without any misleading manipulation. Academic freedom does not provide any exemption from accountability in academic activities of the faculty, nor does it provide any right to act against the well-being of the society, current laws and regulations, and codes of ethical principles and practices.

  3. Mucus-stimulating substances in human body fluids assayed in an invertebrate mucous cell system. (United States)

    Bang, B G; Bang, F B


    An in vitro cell system has been shown to respond differentially to body fluids from normal subjects and from those with disorders of mucus secretion. The urn cell complex of the marine invertebrate Sipunculus nudus responds to mucus-stimulating substances (MSS) in normal human lacrimal fluids and stool filtrates by producing mucus. The process of mucus secretion can be directly observed, and the amount produced can be measured, in a calibrated light microscope. MSS are decreased in lacrimal fluids of patients with dry-eye conditions, while they are periodically increased in filtered stools of patients with acute Shigella dysentery and acute cholera. MSS are remarkably increased isotonic dilutions of sera of rabbits with acute mucoid enteritis, but are absent from sera of normal rabbits. MSS are present in isotonic dilutions of normal human sera which are heated to 85 degrees C for 4 minutes, but are absent from similarly processed sera of immunosuppressed patients. Mean MSS values of heated sera of children with cystic fibrosis are higher than those of controls. The active factor in tears and serum is a large molecule and is heat-stable.

  4. Design and simulation of a new bidirectional actuator for haptic systems featuring MR fluid (United States)

    Hung, Nguyen Quoc; Tri, Diep Bao; Cuong, Vo Van; Choi, Seung-Bok


    In this research, a new configuration of bidirectional actuator featuring MR fluid (BMRA) is proposed for haptic application. The proposed BMRA consists of a driving disc, a driving housing and a driven disc. The driving disc is placed inside the driving housing and rotates counter to each other by a servo DC motor and a bevel gear system. The driven shaft is also placed inside the housing and next to the driving disc. The gap between the two disc and the gap between the discs and the housing are filled with MR fluid. On the driven disc, two mutual magnetic coils are placed. By applying currents to the two coils mutually, the torque at the output shaft, which is fixed to the driven disc, can be controlled with positive, zero or negative value. This make the actuator be suitable for haptic application. After a review of MR fluid and its application, configuration of the proposed BMRA is presented. The modeling of the actuator is then derived based on Bingham rheological model of MRF and magnetic finite element analysis (FEA). The optimal design of the actuator is then performed to minimize the mass of the BMRA. From the optimal design result, performance characteristics of the actuator is simulated and detailed design of a prototype actuator is conducted.

  5. An Efficient Fluid-Dynamic Analysis to Improve Industrial Quenching Systems

    Directory of Open Access Journals (Sweden)

    Manuel de J. Barrena-Rodríguez


    Full Text Available This paper addresses the problem of understanding the relationship between fluid flow and heat transfer in industrial quenching systems. It also presents an efficient analysis to design or optimize long standing quenching tanks to increase productivity. The study case is automotive leaf springs quenched in an oil-tank agitated with submerged jets. This analysis combined an efficient numerical prediction of the detailed isothermal flow field in the whole tank with the thermal characterization of steel probes in plant and laboratory during quenching. These measurements were used to determine the heat flow by solving the inverse heat conduction problem. Differences between laboratory and plant heat flux results were attributed to the difference in surface area size between samples. A proposed correlation between isothermal wall shear stress and heat flux at the surface of the steel component, based on the Reynolds-Colburn analogy, provided the connection between thermal characterization and computed isothermal fluid flow. The present approach allowed the identification of the potential benefits of changes in the tank design and the evaluation of operating conditions while using a much shorter computing time and storage memory than full-domain fluid flow calculations.

  6. New threats to academic freedom. (United States)

    Minerva, Francesca


    Using a specific case as an example, the article argues that the Internet allows dissemination of academic ideas to the general public in ways that can sometimes pose a threat to academic freedom. Since academic freedom is a fundamental element of academia and since it benefits society at large, it is important to safeguard it. Among measures that can be taken in order to achieve this goal, the publication of anonymous research seems to be a good option. © 2013 John Wiley & Sons Ltd.

  7. Educational Vouchers: Freedom to Choose?


    Reel, Jordan; Block, Walter E.


    Milton Friedman is famous for his book title: “Free to Choose.” He also favors educational vouchers, which denies the freedom to choose to people who do not wish to subsidize the education of other people’s children. Thus, he is guilty of a logical contradiction. Why is it important to assess whether Friedman’s views on educational vouchers are logically consistent with his widespread reputation as an advocate of free enterprise, and, thus, freedom to chose? It is important to assess all figu...

  8. Iron Release and Precipitation in Fracture Fluid-Shale Fracturing Systems (United States)

    Jew, A. D.; Joe-Wong, C. M.; Harrison, A. L.; Thomas, D.; Dustin, M. K.; Brown, G. E.; Maher, K.; Bargar, J.


    Hydraulic fracturing of unconventional hydrocarbon reservoirs is important to the United States energy portfolio. Hydrocarbon production from new wells generally declines rapidly over the initial months of production. One possible reason for the decrease is the mineralization and clogging of microfracture networks proximal to propped fractures. One important but relatively unexplored class of reactions is oxidation of Fe(II) derived from Fe(II)-bearing mineral dissolution (primarily pyrite and siderite) and subsequent precipitation of Fe(III)-(oxy)hydroxides. To explore this topic, we reacted fracture fluid with sand-sized and whole rock chips from four different geological localities (Marcellus Fm., Barnett Fm., Eagle Ford Fm., and Green River Fm.) containing highly varied concentrations of clays, carbonates, and TOC. Additionally, kerogen was isolated from the Green River Fm. and reacted with fracture fluid. All the shale sands showed an initial release of Fe into solution during the first 96 hours of reaction followed by a plateau or significant drop in Fe indicating that mineral precipitation occurred. Conversely, the Fe concentrations in the kerogen reactors kept increasing throughout the 3-week experiments. The whole rock samples showed a steady increase then a plateau in Fe during the 3-weeks, indicating a slower Fe release and subsequently, slower Fe precipitation. Reactors with Marcellus Fm. Sands contained dilute HCl, water only, the fracture fluid with no headspace, and fracture fluid with no HCl. Results from these experiments show that HCl is the most important additive for the promotion of Fe release into solution. Iron oxidation is not promoted solely by O2 or organics but instead requires a combination of the two for precipitation in these systems. These results indicate that Fe redox cycling is an important and complex part of hydraulic fracturing that most likely results in production slowdown over the life of a well.

  9. The True Gravitational Degrees Of Freedom

    International Nuclear Information System (INIS)

    Murchadha, N. o


    More than 50 years ago it was realized that General Relativity could be expressed in Hamiltonian form. Unfortunately, just like electromagnetism and Yang-Mills theory, the Einstein equations split into evolution equations and constraints which complicates matters. The 4 constraints are expressions of the gauge freedom of the theory, general covariance. One can cleanly pose initial data for the gravitational field, but this data has to satisfy the constraints. To find the independent degrees of freedom, one needs to factor the initial data by the constraints. There are many ways of doing this. I can do so in such a way as to implement the model suggested by Poincare for a well-posed dynamical system: Pick a configuration space and give the free initial data as a point of the configuration space and a tangent vector at the same point. Now, the evolution equations should give a unique curve in the same configuration space. This gives a natural definition of what I call the true gravitational degrees of freedom. (author)

  10. Painleve Analysis and Darboux Transformation for a Variable-Coefficient Boussinesq System in Fluid Dynamics with Symbolic Computation

    International Nuclear Information System (INIS)

    Li Hongzhe; Tian Bo; Li Lili; Zhang Haiqiang


    The new soliton solutions for the variable-coefficient Boussinesq system, whose applications are seen in fluid dynamics, are studied in this paper with symbolic computation. First, the Painleve analysis is used to investigate its integrability properties. For the identified case we give, the Lax pair of the system is found, and then the Darboux transformation is constructed. At last, some new soliton solutions are presented via the Darboux method. Those solutions might be of some value in fluid dynamics. (general)

  11. Investigation of fluid flow in various geometries related to nuclear reactor using PIV system

    International Nuclear Information System (INIS)

    Kansal, A.K.; Maheshwari, N.K.; Singh, R.K.; Vijayan, P.K.; Saha, D.; Singh, R.K.; Joshi, V.M.


    Particle Image Velocimetry (PIV) is a non-intrusive technique for simultaneously measuring the velocities at many points in a fluid flow. The PIV system used is comprised of Nd:YAG laser source, CCD (Charged Coupled Device) camera, timing controller (to control the laser and camera) and software used for analyzing the flow velocities. Several case studies related to nuclear reactor were performed with the PIV system. Some of the cases like flow in circular tube, submerged jet, natural convection in a water pool, flow field of moderator inlet diffuser of 500 MWe Pressurised Heavy Water Reactor (PHWR) and fluidic flow control device (FFCD) used in advanced accumulator of Emergency Core Cooling System (ECCS) have been studied using PIV system. Theoretical studies have been performed and comparisons with PIV results are also given in the present studies. (author)

  12. Fault and fluid systems in supra-subduction zones: The Troodos ophiolite (United States)

    Quandt, Dennis; Micheuz, Peter; Kurz, Walter; Krenn, Kurt


    The Troodos massif on the island of Cyprus represents a well-preserved and complete supra-subduction zone (SSZ) ophiolite. It includes an extrusive sequence that is subdivided into Upper (UPL) and Lower Pillow Lavas (LPL). These volcanic rocks contain mineralized fractures (veins) and vesicles that record fluid availability probably related to slab dehydration and deformation subsequent to a period of subduction initiation in the framework of a SSZ setting. Here, we present electron microprobe element mappings and cathodoluminescence studies of vein minerals as well as analyses of fluid inclusions entrapped in zeolite, calcite and quartz from veins and vesicles of the Pillow Lavas of the Troodos ophiolite. Two different zeolite type assemblages, interpreted as alteration products of compositional varying volcanic glasses, occur: (1) Na-zeolites analcime and natrolite from the UPL that require lower formation temperatures, higher Na/Ca ratios and pH values than (2) Ca-zeolites heulandite and mordenite from the LPL which indicate temporal or spatial varying fluid compositions and conditions. Calcite represents a late stage phase in incompletely sealed blocky type (1) assemblage and in syntaxial quartz veins. Additionally, calcite occurs as major phase in syntaxial and blocky veins of UPL and LPL. These syntaxial quartz and calcite veins are assumed to be related to tectonic extension. Chalcedony is associated with quartz and occurs in typical veins and vesicles of the LPL. In addition, the presence of neptunian dykes in veins suggests that seawater penetrated fractures throughout the extrusive sequence. Thus, circulation in an open system via advective transport is favored while diffusion in a closed system is a subordinate, local and late stage phenomenon. Calcite veins and quartz vesicles contain primary, partly re-equilibrated two phase (liquid, vapor) fluid inclusions. The chemical system of all studied inclusions in both host minerals is restricted to aqueous

  13. Study on Mixed Working Fluids with Different Compositions in Organic Rankine Cycle (ORC Systems for Vehicle Diesel Engines

    Directory of Open Access Journals (Sweden)

    Kai Yang


    Full Text Available One way to increase the thermal efficiency of vehicle diesel engines is to recover waste heat by using an organic Rankine cycle (ORC system. Tests were conducted to study the running performances of diesel engines in the whole operating range. The law of variation of the exhaust energy rate under various engine operating conditions was also analyzed. A diesel engine-ORC combined system was designed, and relevant evaluation indexes proposed. The variation of the running performances of the combined system under various engine operating conditions was investigated. R245fa and R152a were selected as the components of the mixed working fluid. Thereafter, six kinds of mixed working fluids with different compositions were presented. The effects of mixed working fluids with different compositions on the running performances of the combined system were revealed. Results show that the running performances of the combined system can be improved effectively when mass fraction R152a in the mixed working fluid is high and the engine operates with high power. For the mixed working fluid M1 (R245fa/R152a, 0.1/0.9, by mass fraction, the net power output of the combined system reaches the maximum of 34.61 kW. Output energy density of working fluid (OEDWF, waste heat recovery efficiency (WHRE, and engine thermal efficiency increasing ratio (ETEIR all reach their maximum values at 42.7 kJ/kg, 10.90%, and 11.29%, respectively.

  14. Molecular degrees of freedom: resonances and orbiting

    Energy Technology Data Exchange (ETDEWEB)

    Shapira, D.; Erb, K.A.


    Studies of orbiting and other gross features of heavy ion induced reactions show that molecular degrees of freedom play a significant role. The formation of a rotating dinuclear molecule appears as a general feature, and the radii derived for these dinuclear systems are larger than the radii of the conventional nucleus-nucleus potential. These large radii for the molecular bonding potential are similar to those derived from systematic studies performed recently on resonances in the /sup 12/C + /sup 12/C + /sup 16/O systems.

  15. Fluid and rock interactions in silicate and aluminosilicate systems at elevated pressure and temperature (United States)

    Davis, Mary Kathleen

    Understanding fluid chemistry in the subduction zone environment is key to unraveling the details of element transport from the slab to the surface. Solubilities of cations, such as silicon, in water strongly affect both the physical and chemical properties of supercritical metamorphic fluids. Modeling the thermodynamics of fluid-rock interactions requires therefore a profound understanding of cation dissolution and aqueous speciation. In situ Raman experiments of the silica-water, alumina-water, and alumina water systems were performed in an externally heated Bassett-type diamond-anvil cell at the Department of Geological Sciences, University of Michigan. Natural quartz samples and synthetic ruby samples were used in the experiments. Samples were loaded in the sample chamber with a water pressure medium. All experiments used rhenium gaskets of uniform thickness with a 500 mum drill hole for the sample chamber. Temperature was measured using K-type thermocouples encompassing both the upper and lower diamond anvils. Pressures are obtained on the basis of the Raman shift of the 464 cm-1 quartz mode where possible or the Raman shift of the tips of the diamond anvils according to a method developed in this work. This work characterizes the state of stress in the diamond anvil cell, which is used as the basis for the pressure calibration using only the diamond anvils. Raman measurements of silicate fluid confirm the presence of H4 SiO4 and H6Si2O7 in solution and expand the pressure range for in-situ structural observations in the silica-water system. Additionally, we identify the presence of another silica species present at mantle conditions, which occurs at long time scales in the diamond cell. This study provides the first in situ data in the alumina-water and alumina-silica-water systems at pressures and temperatures relevant to the slab environment. Al(OH) 3 appears to be the dominant form of alumina present under these conditions and in the alumina

  16. Development of real-time visualization system for Computational Fluid Dynamics on parallel computers

    International Nuclear Information System (INIS)

    Muramatsu, Kazuhiro; Otani, Takayuki; Matsumoto, Hideki; Takei, Toshifumi; Doi, Shun


    A real-time visualization system for computational fluid dynamics in a network connecting between a parallel computing server and the client terminal was developed. Using the system, a user can visualize the results of a CFD (Computational Fluid Dynamics) simulation on the parallel computer as a client terminal during the actual computation on a server. Using GUI (Graphical User Interface) on the client terminal, to user is also able to change parameters of the analysis and visualization during the real-time of the calculation. The system carries out both of CFD simulation and generation of a pixel image data on the parallel computer, and compresses the data. Therefore, the amount of data from the parallel computer to the client is so small in comparison with no compression that the user can enjoy the swift image appearance comfortably. Parallelization of image data generation is based on Owner Computation Rule. GUI on the client is built on Java applet. A real-time visualization is thus possible on the client PC only if Web browser is implemented on it. (author)

  17. Fluid dynamics of acoustic and hydrodynamic cavitation in hydraulic power systems. (United States)

    Ferrari, A


    Cavitation is the transition from a liquid to a vapour phase, due to a drop in pressure to the level of the vapour tension of the fluid. Two kinds of cavitation have been reviewed here: acoustic cavitation and hydrodynamic cavitation. As acoustic cavitation in engineering systems is related to the propagation of waves through a region subjected to liquid vaporization, the available expressions of the sound speed are discussed. One of the main effects of hydrodynamic cavitation in the nozzles and orifices of hydraulic power systems is a reduction in flow permeability. Different discharge coefficient formulae are analysed in this paper: the Reynolds number and the cavitation number result to be the key fluid dynamical parameters for liquid and cavitating flows, respectively. The latest advances in the characterization of different cavitation regimes in a nozzle, as the cavitation number reduces, are presented. The physical cause of choked flows is explained, and an analogy between cavitation and supersonic aerodynamic flows is proposed. The main approaches to cavitation modelling in hydraulic power systems are also reviewed: these are divided into homogeneous-mixture and two-phase models. The homogeneous-mixture models are further subdivided into barotropic and baroclinic models. The advantages and disadvantages of an implementation of the complete Rayleigh-Plesset equation are examined.

  18. Research on integrated simulation of fluid-structure system by computation science techniques

    International Nuclear Information System (INIS)

    Yamaguchi, Akira


    In Power Reactor and Nuclear Fuel Development Corporation, the research on the integrated simulation of fluid-structure system by computation science techniques has been carried out, and by its achievement, the verification of plant systems which has depended on large scale experiments is substituted by computation science techniques, in this way, it has been aimed at to reduce development costs and to attain the optimization of FBR systems. For the purpose, it is necessary to establish the technology for integrally and accurately analyzing complicated phenomena (simulation technology), the technology for applying it to large scale problems (speed increasing technology), and the technology for assuring the reliability of the results of analysis when simulation technology is utilized for the permission and approval of FBRs (verifying technology). The simulation of fluid-structure interaction, the heat flow simulation in the space with complicated form and the related technologies are explained. As the utilization of computation science techniques, the elucidation of phenomena by numerical experiment and the numerical simulation as the substitute for tests are discussed. (K.I.)

  19. Fluid pipeline system leak detection based on neural network and pattern recognition

    International Nuclear Information System (INIS)

    Tang Xiujia


    The mechanism of the stress wave propagation along the pipeline system of NPP, caused by turbulent ejection from pipeline leakage, is researched. A series of characteristic index are described in time domain or frequency domain, and compress numerical algorithm is developed for original data compression. A back propagation neural networks (BPNN) with the input matrix composed by stress wave characteristics in time domain or frequency domain is first proposed to classify various situations of the pipeline, in order to detect the leakage in the fluid flow pipelines. The capability of the new method had been demonstrated by experiments and finally used to design a handy instrument for the pipeline leakage detection. Usually a pipeline system has many inner branches and often in adjusting dynamic condition, it is difficult for traditional pipeline diagnosis facilities to identify the difference between inner pipeline operation and pipeline fault. The author first proposed pipeline wave propagation identification by pattern recognition to diagnose pipeline leak. A series of pattern primitives such as peaks, valleys, horizon lines, capstan peaks, dominant relations, slave relations, etc., are used to extract features of the negative pressure wave form. The context-free grammar of symbolic representation of the negative wave form is used, and a negative wave form parsing system with application to structural pattern recognition based on the representation is first proposed to detect and localize leaks of the fluid pipelines

  20. Renormalization group and asymptotic freedom

    International Nuclear Information System (INIS)

    Morris, J.R.


    Several field theoretic models are presented which allow exact expressions of the renormalization constants and renormalized coupling constants. These models are analyzed as to their content of asymptotic free field behavior through the use of the Callan-Symanzik renormalization group equation. It is found that none of these models possesses asymptotic freedom in four dimensions

  1. On Procedural Freedom of Choice

    NARCIS (Netherlands)

    Arlegi, R.; Dimitrov, D.A.


    Numerous works in the last decade have analyzed the question of how to compare opportunity sets as a way to measure and evaluate individual freedom of choice.This paper defends that, in many contexts, external procedural aspects that are associated to an opportunity set should be taken into account

  2. Academic Freedom: A Lawyer's Perspective (United States)

    Davies, Mark


    Academic freedom is central to ideas of higher education, yet in the United Kingdom it is facing challenges from changing managerial approaches within some universities and changing governmental expectations. Universities are increasingly expected to focus upon knowledge which can be shown to have value and to exploit the results of academic…

  3. No School like Freedom School (United States)

    Williamson, Lisa Ann


    "You are the hope of the future." That's the message Marian Wright Edelman, executive director of the Children's Defense Fund (CDF), gave more than 1,500 excited college students and recent graduates as they began a week-long training for the CDF's Freedom Schools. She was preparing them for a daunting task--that of transforming the…

  4. The Specific Value of Freedom

    NARCIS (Netherlands)

    van Hees, Martin


    Freedom is among the most important values in political life, yet there has always been a great deal of disagreement about what this value demands from us. Libertarians argue that it requires that we protect each person's right to own and exchange private property. Liberals argue that it requires

  5. Tenure, Academic Freedom, and Governance. (United States)

    Perley, James E.


    Tenure itself is not the central issue in the debate over faculty tenure; honest faculty evaluation, adequate faculty development, and termination when appropriate are the real issues as are fears that abandonment of the tenure principle would amount to abandonment of the principles of academic freedom and shared governance. (MSE)

  6. Large Matched-Index-of-Refraction (MIR) Flow Systems for International Collaboration In Fluid Mechanics

    International Nuclear Information System (INIS)

    McEligot, Donald M.; Becker, Stefan; McIlroy, Hugh M. Jr.


    In recent international collaboration, INL and Uni. Erlangen have developed large MIR flow systems which can be ideal for joint graduate student education and research. The benefit of the MIR technique is that it permits optical measurements to determine flow characteristics in complex passages and around objects to be obtained without locating a disturbing transducer in the flow field and without distortion of the optical paths. The MIR technique is not new itself; others employed it earlier. The innovation of these MIR systems is their large size relative to previous experiments, yielding improved spatial and temporal resolution. This report will discuss the benefits of the technique, characteristics of the systems and some examples of their applications to complex situations. Typically their experiments have provided new fundamental understanding plus benchmark data for assessment and possible validation of computational thermal fluid dynamic codes.

  7. A warning system based on the RFID technology for running-out of injection fluid. (United States)

    Huang, Chi-Fang; Lin, Jen-Hung


    For providing an automatic warning system of running-out of injection fluid, RFID technology is applied in this work to propose an infrastructure with low cost to help nurses and patient's company. Specially, a RFID tag is designed and attached on a bag of intravenous drip to demonstrate the benefits in the present system. The main idea of this system is that, tag is disabled when the bag is not empty because of the EM loading due to the liquid contained. The bag can be any kind in the current market and be without any electronic attachment or modification. LAN (Local Area Network) is also applied as a part of this infrastructure for data transmission.

  8. Survey of a numerical procedure for the solution of hyperbolic systems of three dimensional fluid flow

    International Nuclear Information System (INIS)

    Graf, U.


    A combination of several numerical methods is used to construct a procedure for effective calculation of complex three-dimensional fluid flow problems. The split coefficient matrix (SCM) method is used so that the differenced equations of the hyperbolic system do not disturb correct signal propagation. The semi-discretisation of the equations of the SCM method is done with the asymmetric, separated region, weighted residual (ASWR) method to give accurate solutions on a relatively coarse mesh. For the resulting system of ordinary differential equations, a general-purpose ordinary differential equation solver is used in conjunction with a method of fractional steps for an economic solution of the large system of linear equations. (orig.) [de

  9. C-O-H-S magmatic fluid system in shrinkage bubbles of melt inclusions (United States)

    Robidoux, P.; Frezzotti, M. L.; Hauri, E. H.; Aiuppa, A.


    Magmatic volatiles include multiple phases in the C-O-H-S system of shrinkage bubbles for which a conceptual model is still unclear during melt inclusion formation [1,2,3,4]. The present study aims to qualitatively explore the evolution of the volatile migration, during and after the formation of the shrinkage bubble in melt inclusions trapped by olivines from Holocene to present at San Cristóbal volcano (Nicaragua), Central American Volcanic Arc (CAVA). Combined scanning electron microscope (SEM) and Raman spectroscopy observations allow to define the mineral-fluid phases inside typical shrinkage bubbles at ambient temperature. The existence of residual liquid water is demonstrated in the shrinkage bubbles of naturally quenched melt inclusion and this water could represents the principal agent for chemical reactions with other dissolved ionic species (SO42-, CO32-, etc.) and major elements (Mg, Fe, Cu, etc.) [4,5]. With the objective of following the cooling story of the bubble-inclusion system, the new methodological approach here estimate the interval of equilibrium temperatures for each SEM-Raman identified mineral phase (carbonates, hydrous carbonates, sulfurs, sulfates, etc.). Finally, two distinct mechanisms are proposed to describe the evolution of this heterogeneous fluid system in bubble samples at San Cristóbal which imply a close re-examination for similar volcanoes in subduction zone settings: (1) bubbles are already contracted and filled by volatiles by diffusion processes from the glass and leading to a C-O-H-S fluid-glass reaction enriched in Mg-Fe-Cu elements (2) bubbles are formed by oversaturation of the volatiles from the magma which is producing an immiscible metal-rich fluid. [1]Moore et al. (2015). Am. Mineral. 100, 806-823 [2]Wallace et al. (2015). Am. Mineral. 100, 787-794 [3]Lowenstern (2015). Am. Mineral. 100, 672-673 [4]Esposito, et al. (2016). Am. Mineral. 101, 1691-1708 [5]Kamenetsky et al. (2001). Earth Planet. Sci. Lett. 184, 685-702

  10. Cerebrospinal fluid analysis in fatal thallium poisoning: evidence for delayed distribution into the central nervous system. (United States)

    Sharma, Adhi N; Nelson, Lewis S; Hoffman, Robert S


    The neurologic manifestations of thallium poisoning include a severely painful ascending peripheral neuropathy, autonomic dysfunction, cranial nerve abnormalities, and a toxic encephalopathy. Although thallium has a short half-life, these neurologic manifestations commonly progress, even as the blood concentration of thallium decreases. This suggests either that thallium persists in neuronal tissues or that it initiates an injury cascade that takes time to fully manifest. As the latter mechanism is consistent with many toxin exposures, the concept of a central nervous system reservoir for thallium is often discounted. A recent case provided a unique opportunity to evaluate this possibility. A 48-year-old man was acutely and chronically thallium poisoned by his common-law wife. During his initial exposures, only gastrointestinal symptoms manifested. Following an acute ingestion, hospitalization was required. Over 3 days, his symptoms rapidly progressed from a severely painful neuropathy to slurred speech, ptosis, confusion, coma, respiratory insufficiency, and death. Because of considerations of alternative diagnoses, 2 lumbar punctures were performed, one on admission and another on the day of his death. Serum thallium concentrations obtained from stored blood samples were paired with spinal fluid concentrations from the same days. On day 1, serum and spinal fluid concentrations were 8700 mu/L and 1200 mu/L, respectively. On day 3, although the serum concentration had fallen to 7200 mu/L, the spinal fluid concentration had increased to 2100 mu/L. This case provides evidence to support the hypothesis that thallium distributes into the central nervous system more slowly than the blood compartment, and this may in part account for the progression of neurologic findings in the setting of decreasing serum concentrations.

  11. Studies on variable swirl intake system for DI diesel engine using computational fluid dynamics

    Directory of Open Access Journals (Sweden)

    Jebamani Rathnaraj David


    Full Text Available It is known that a helical port is more effective than a tangential port to attain the required swirl ratio with minimum sacrifice in the volumetric efficiency. The swirl port is designed for lesser swirl ratio to reduce emissions at higher speeds. But this condition increases the air fuel mixing time and particulate smoke emissions at lower speeds. Optimum swirl ratio is necessary according to the engine operating condition for optimum combustion and emission reduction. Hence the engine needs variable swirl to enhance the combustion in the cylinder according to its operating conditions, for example at partial load or low speed condition it requires stronger swirl, while the air quantity is more important than the swirl under very high speed or full load and maximum torque conditions. The swirl and charging quantity can easily trade off and can be controlled by the opening of the valve. Hence in this study the steady flow rig experiment is used to evaluate the swirl of a helical intake port design for different operating conditions. The variable swirl plate set up of the W06DTIE2 engine is used to experimentally study the swirl variation for different openings of the valve. The sliding of the swirl plate results in the variation of the area of inlet port entry. Therefore in this study a swirl optimized combustion system varying according to the operating conditions by a variable swirl plate mechanism is studied experimentally and compared with the computational fluid dynamics predictions. In this study the fluent computational fluid dynamics code has been used to evaluate the flow in the port-cylinder system of a DI diesel engine in a steady flow rig. The computational grid is generated directly from 3-D CAD data and in cylinder flow simulations, with inflow boundary conditions from experimental measurements, are made using the fluent computational fluid dynamics code. The results are in very good agreement with experimental results.

  12. Cryogenic fluid management (base R/T): Cryogenic fluid systems, Cryogenic Orbital Nitrogen Experiment (CONE), Cryogenic Orbital Hydrogen Experiment (COHE). (Transportation focused technology) (United States)

    Symons, Pat


    The topics presented are covered in viewgraph form. The concluded remarks are: (1) advanced cryogenic fluid systems technology is enhancing or enabling to all known transportation scenarios for space exploration; (2) an integrated/coordinated program involving LeRC/MSFC has been formulated to address all known CFM needs - new needs should they develop, can be accommodated within available skills/facilities; (3) all required/experienced personnel and facilities are finally in place - data from initial ground-based experiments is being collected and analyzed - small scale STS experiments are nearing flight - program is beginning to yield significant results; (4) future proposed funding to primarily come from two sources; and (5) cryogenic fluid experimentation is essential to provide required technology and assure implementation in future NASA missions.

  13. Computational fluid dynamic assisted control system design methodology using system identification technique for CANDU supercritical water cooled reactor (SCWR)

    International Nuclear Information System (INIS)

    Maitri, Rohit V.; Zhang, Chao; Jiang, Jin


    The supercritical water cooled reactor (SCWR) is one of the six Generation IV nuclear reactors. A novel control system design method for the Canadian SCWR, known as CANDU SCWR, is developed in this study. The main dynamic of this reactor can be represented as a multiple input and multiple output (MIMO) system governed by highly non-linear partial differential equations. Even though the non-linear governing equations of such a reactor can be solved using computational fluid dynamics (CFD) techniques, it is difficult to convert the existing non-linear partial differential equations to linear dynamic models to facilitate its control system design. To deal with this problem, a new approach is developed herein, which uses the results from CFD simulations to derive the linear dynamic models around several chosen operating points based on system identification techniques. The derived linear dynamic models have been validated by comparing it with the data from the non-linear dynamic model.

  14. Old Dilemmas Renewed: Fear of Freedom vs. Freedom from Fear

    Directory of Open Access Journals (Sweden)

    Aleksandra Gruszczyk


    Full Text Available Contemporary societies are currently subjected to very rapid and radical social changes and, as a consequence, struggle with their outcomes. The results range from the unforeseen repercussions of globally shifting political powers, through rising nationalisms, to prolonged economic, environmental, political and humanitarian crises. Critical analysis of the theories focused on the phenomena of authoritarianism, escapism, political myth, and conformity allows for outlining a comprehensive picture of the universally recognized opposition between freedom and security. From the distinction between the positive and negative freedom to the ambiguity surrounding the concept of “freedom from fear”, the fundamental dilemma is viewed from a historical perspective and illustrated with modern examples, emphasizing its current validity, insightfulness and potential in analyzing contemporary global problems. This approach allows for in-depth analyses of diversified social and political issues, such as the North African-European refugee crisis, rising nationalisms in the Western world, or a marked shift in political and social perspectives worldwide, from modern escapism to the birth of new myths of state.


    Directory of Open Access Journals (Sweden)



    Full Text Available In this study, we proposed a newly designed sulfuric acid transfer system for the sulfur-iodine (SI thermochemical cycle. The proposed sulfuric acid transfer system was evaluated using a computational fluid dynamics (CFD analysis for investigating thermodynamic/hydrodynamic characteristics and material properties. This analysis was conducted to obtain reliable continuous operation parameters; in particular, a thermal analysis was performed on the bellows box and bellows at amplitudes and various frequencies (0.1, 0.5, and 1.0 Hz. However, the high temperatures and strongly corrosive operating conditions of the current sulfuric acid system present challenges with respect to the structural materials of the transfer system. To resolve this issue, we designed a novel transfer system using polytetrafluoroethylene (PTFE, Teflon® as a bellows material for the transfer of sulfuric acid. We also carried out a CFD analysis of the design. The CFD results indicated that the maximum applicable temperature of PTFE is about 533 K (260 °C, even though its melting point is around 600 K. This result implies that the PTFE is a potential material for the sulfuric acid transfer system. The CFD simulations also confirmed that the sulfuric acid transfer system was designed properly for this particular investigation.

  16. An evaluation of radioxenon detection techniques for use with a fluid-based concentration system

    Energy Technology Data Exchange (ETDEWEB)

    Russ, W.R.; Stuenkel, D.O.; Valentine, J.D. [Univ. of Cincinnati, OH (United States). Nuclear and Radiological Engineering Program; Gross, K.C. [Argonne National Lab., IL (United States). Reactor Analysis Div.


    A portable monitoring system to measure the quantity of radioxenon ({sup 131m}Xe, {sup 133}Xe, {sup 133m}Xe, and {sup 135}Xe) in the atmosphere is being developed which incorporates a fluid-based concentration system with a detection system. To this end a number of radioxenon detection techniques have been evaluated to determine the best method of analyzing the output of the concentration system, which may contain significant amounts of radon in addition to concentrated xenon. Three detector configurations have been tested to measure the characteristic electron/photon coincidence radiation: plastic scintillator/NaI(Tl), gas proportional detector/NaI(Tl), and liquid scintillator/NaI(Tl). In addition to standard coincidence measurements, some additional gating criteria were also used; pulse height discrimination, pulse shape discrimination, and delayed coincidence. While the lowest relative minimum detectable activity was achieved using the liquid scintillator with delayed coincidence gating, the best performance for fieldable detection systems depends on the ratio of xenon to radon in the output of the concentration system. A high ratio favors the use of a gas proportional/NaI(Tl) detector using coincidence gating with pulse height discrimination. The use of a plastic scintillator/NaI(Tl) detector using coincidence gating with pulse shape discrimination is preferred when the ratio is low. A portable system that monitors the abundance and ratios of atmospheric radioxenon isotopes is required for use in the field to detect nuclear weapons testing.

  17. Effect of drilling fluid systems and temperature on oil mist and vapour levels generated from shale shaker. (United States)

    Steinsvåg, Kjersti; Galea, Karen S; Krüger, Kirsti; Peikli, Vegard; Sánchez-Jiménez, Araceli; Sætvedt, Esther; Searl, Alison; Cherrie, John W; van Tongeren, Martie


    Workers in the drilling section of the offshore petroleum industry are exposed to air pollutants generated by drilling fluids. Oil mist and oil vapour concentrations have been measured in the drilling fluid processing areas for decades; however, little work has been carried out to investigate exposure determinants such as drilling fluid viscosity and temperature. A study was undertaken to investigate the effect of two different oil-based drilling fluid systems and their temperature on oil mist, oil vapour, and total volatile organic compounds (TVOC) levels in a simulated shale shaker room at a purpose-built test centre. Oil mist and oil vapour concentrations were sampled simultaneously using a sampling arrangement consisting of a Millipore closed cassette loaded with glass fibre and cellulose acetate filters attached to a backup charcoal tube. TVOCs were measured by a PhoCheck photo-ionization detector direct reading instrument. Concentrations of oil mist, oil vapour, and TVOC in the atmosphere surrounding the shale shaker were assessed during three separate test periods. Two oil-based drilling fluids, denoted 'System 2.0' and 'System 3.5', containing base oils with a viscosity of 2.0 and 3.3-3.7 mm(2) s(-1) at 40°C, respectively, were used at temperatures ranging from 40 to 75°C. In general, the System 2.0 yielded low oil mist levels, but high oil vapour concentrations, while the opposite was found for the System 3.5. Statistical significant differences between the drilling fluid systems were found for oil mist (P = 0.025),vapour (P oil mist, oil vapour, and TVOC levels. Oil vapour levels at the test facility exceeded the Norwegian oil vapour occupational exposure limit (OEL) of 30 mg m(-3) when the drilling fluid temperature was ≥50°C. The practice of testing compliance of oil vapour exposure from drilling fluids systems containing base oils with viscosity of ≤2.0 mm(2) s(-1) at 40°C against the Norwegian oil vapour OEL is questioned since these base oils

  18. Use of Generalized Fluid System Simulation Program (GFSSP) for Teaching and Performing Senior Design Projects at the Educational Institutions (United States)

    Majumdar, A. K.; Hedayat, A.


    This paper describes the experience of the authors in using the Generalized Fluid System Simulation Program (GFSSP) in teaching Design of Thermal Systems class at University of Alabama in Huntsville. GFSSP is a finite volume based thermo-fluid system network analysis code, developed at NASA/Marshall Space Flight Center, and is extensively used in NASA, Department of Defense, and aerospace industries for propulsion system design, analysis, and performance evaluation. The educational version of GFSSP is freely available to all US higher education institutions. The main purpose of the paper is to illustrate the utilization of this user-friendly code for the thermal systems design and fluid engineering courses and to encourage the instructors to utilize the code for the class assignments as well as senior design projects.

  19. Presentation of a new magnetic field therapy system for the treatment of human solid tumors with magnetic fluid hyperthermia

    International Nuclear Information System (INIS)

    Jordan, Andreas; Scholz, Regina; Maier-Hauff, Klaus; Johannsen, Manfred; Wust, Peter; Nadobny, Jacek; Schirra, Hermann; Schmidt, Helmut; Deger, Serdar; Loening, Stefan; Lanksch, Wolfgang; Felix, Roland


    Magnetic fluid hyperthermia (MFH) selectively heats up tissue by coupling alternating current (AC) magnetic fields to targeted magnetic fluids, so that boundaries of different conductive tissues do not interfere with power absorption. In this paper, a new AC magnetic field therapy system for clinical application of MFH is described. With optimized magnetic nanoparticle preparations it will be used for target-specific glioblastoma and prostate carcinoma therapy

  20. Partitioning behavior of chlorine and fluorine in the system apatite melt fluid. II: Felsic silicate systems at 200 MPa (United States)

    Webster, James D.; Tappen, Christine M.; Mandeville, Charles W.


    Hydrothermal experiments were conducted to determine the partitioning of Cl between rhyolitic to rhyodacitic melts, apatite, and aqueous fluid(s) and the partitioning of F between apatite and these melts at ca. 200 MPa and 900-924 °C. The number of fluid phases in our experiments is unknown; they may have involved a single fluid or vapor plus saline liquid. The partitioning behavior of Cl between apatite and melt is non-Nernstian and is a complex function of melt composition and the Cl concentration of the system. Values of DClapat/melt (wt. fraction of: Cl in apatite/Cl in melt) vary from 1 to 4.5 and are largest when the Cl concentrations of the melt are at or near the Cl-saturation value of the melt. The Cl-saturation concentrations of silicate melts are lowest in evolved, silica-rich melts, so with elevated Cl concentrations in a system and with all else equal, the maximum values of DClapat/melt occur with the most felsic melt. In contrast, values of DFapat/melt range from 11 to 40 for these felsic melts, and many of these are an order of magnitude greater than those applying to basaltic melts at 200 MPa and 1066-1150 °C. The Cl concentration of apatite is a simple and linear function of the concentration of Cl in fluid. Values of DClfluid/apat for these experiments range from 9 to 43, and some values are an order of magnitude greater than those determined in 200-MPa experiments involving basaltic melts at 1066-1150 °C. In order to determine the concentrations and interpret the behavior of volatile components in magmas, the experimental data have been applied to the halogen concentrations of apatite grains from chemically evolved rocks of Augustine volcano, Alaska; Krakatau volcano, Indonesia; Mt. Pinatubo, Philippines; Mt. St. Helens, Washington; Mt. Mazama, Oregon; Lascar volcano, Chile; Santorini volcano, Greece, and the Bishop Tuff, California. The F concentrations of these magmas estimated from apatite-melt equilibria range from 0.06 to 0.12 wt% and are

  1. Systems and Methods for Determining Water-Cut of a Fluid Mixture

    KAUST Repository

    Karimi, Muhammad Akram


    Provided in some embodiments are systems and methods for measuring the water content (or water-cut) of a fluid mixture. Provided in some embodiments is a water-cut sensor system that includes a T-resonator, a ground conductor, and a separator. The T-resonator including a feed line, and an open shunt stub conductively coupled to the feed line. The ground conductor including a bottom ground plane opposite the T-resonator and a ground ring conductively coupled to the bottom ground plane, with the feed line overlapping at least a portion of the ground ring. The separator including a dielectric material disposed between the feed line and the portion of the ground ring overlapped by the feed line, and the separator being adapted to electrically isolate the T-resonator from the ground conductor.

  2. Systems and Methods for Determining Water-Cut of a Fluid Mixture

    KAUST Repository

    Karimi, Muhammad Akram


    Provided in some embodiments are systems and methods for measuring the water content (or water-cut) of a fluid mixture. Provided in some embodiments is a water-cut sensor system that includes a helical T-resonator, a helical ground conductor, and a separator provided at an exterior of a cylindrical pipe. The helical T-resonator including a feed line, and a helical open shunt stub conductively coupled to the feed line. The helical ground conductor including a helical ground plane opposite the helical open shunt stub and a ground ring conductively coupled to the helical ground plane. The feed line overlapping at least a portion of the ground ring, and the separator disposed between the feed line and the portion of the ground ring overlapped by the feed line to electrically isolate the helical T-resonator from the helical ground conductor.

  3. Linear image reconstruction for a diffuse optical mammography system in a noncompressed geometry using scattering fluid

    International Nuclear Information System (INIS)

    Nielsen, Tim; Brendel, Bernhard; Ziegler, Ronny; Beek, Michiel van; Uhlemann, Falk; Bontus, Claas; Koehler, Thomas


    Diffuse optical tomography (DOT) is a potential new imaging modality to detect or monitor breast lesions. Recently, Philips developed a new DOT system capable of transmission and fluorescence imaging, where the investigated breast is hanging freely into the measurement cup containing scattering fluid. We present a fast and robust image reconstruction algorithm that is used for the transmission measurements. The algorithm is based on the Rytov approximation. We show that this algorithm can be used over a wide range of tissue optical properties if the reconstruction is adapted to each patient. We use estimates of the breast shape and average tissue optical properties to initialize the reconstruction, which improves the image quality significantly. We demonstrate the capability of the measurement system and reconstruction to image breast lesions by clinical examples

  4. Cerebrospinal fluid analysis in the HIV infection and compartmentalization of HIV in the central nervous system

    Directory of Open Access Journals (Sweden)

    Sérgio Monteiro de Almeida


    Full Text Available The nervous system plays an important role in HIV infection. The purpose of this review is to discuss the indications for cerebrospinal fluid (CSF analysis in HIV infection in clinical practice. CSF analysis in HIV infection is indicated for the diagnosis of opportunistic infections and co-infections, diagnosis of meningitis caused by HIV, quantification of HIV viral load, and analysis of CNS HIV compartmentalization. Although several CSF biomarkers have been investigated, none are clinically applicable. The capacity of HIV to generate genetic diversity, in association with the constitutional characteristics of the CNS, facilitates the generation of HIV quasispecies in the CNS that are distinct from HIV in the systemic circulation. CSF analysis has a well-defined and valuable role in the diagnosis of CNS infections in HIV/AIDS patients. Further research is necessary to establish a clinically applicable biomarker for the diagnosis of HIV-associated neurocognitive disorders.

  5. Temperature and velocity measurement fields of fluids using a schlieren system. (United States)

    Martínez-González, Adrian; Guerrero-Viramontes, J A; Moreno-Hernández, David


    This paper proposes a combined method for two-dimensional temperature and velocity measurements in liquid and gas flow using a schlieren system. Temperature measurements are made by relating the intensity level of each pixel in a schlieren image to the corresponding knife-edge position measured at the exit focal plane of the schlieren system. The same schlieren images were also used to measure the velocity of the fluid flow. The measurement is made by using particle image velocimetry (PIV). The PIV software used in this work analyzes motion between consecutive schlieren frames to obtain velocity fields. The proposed technique was applied to measure the temperature and velocity fields in the natural convection of water provoked by a heated rectangular plate.

  6. Steel slag carbonation in a flow-through reactor system: the role of fluid-flux. (United States)

    Berryman, Eleanor J; Williams-Jones, Anthony E; Migdisov, Artashes A


    Steel production is currently the largest industrial source of atmospheric CO2. As annual steel production continues to grow, the need for effective methods of reducing its carbon footprint increases correspondingly. The carbonation of the calcium-bearing phases in steel slag generated during basic oxygen furnace (BOF) steel production, in particular its major constituent, larnite {Ca2SiO4}, which is a structural analogue of olivine {(MgFe)2SiO4}, the main mineral subjected to natural carbonation in peridotites, offers the potential to offset some of these emissions. However, the controls on the nature and efficiency of steel slag carbonation are yet to be completely understood. Experiments were conducted exposing steel slag grains to a CO2-H2O mixture in both batch and flow-through reactors to investigate the impact of temperature, fluid flux, and reaction gradient on the dissolution and carbonation of steel slag. The results of these experiments show that dissolution and carbonation of BOF steel slag are more efficient in a flow-through reactor than in the batch reactors used in most previous studies. Moreover, they show that fluid flux needs to be optimized in addition to grain size, pressure, and temperature, in order to maximize the efficiency of carbonation. Based on these results, a two-stage reactor consisting of a high and a low fluid-flux chamber is proposed for CO2 sequestration by steel slag carbonation, allowing dissolution of the slag and precipitation of calcium carbonate to occur within a single flow-through system. Copyright © 2014. Published by Elsevier B.V.

  7. 76 FR 3815 - Religious Freedom Day, 2011 (United States)


    ... weighty task of ensuring freedom of religious expression and practice, we have remained a Nation in which... Part V The President Proclamation 8623--Religious Freedom Day, 2011 Proclamation 8624--Martin... President [[Page 3817

  8. 78 FR 68325 - World Freedom Day, 2013 (United States)


    ... Freedom Day, we remember that for all the raw power of authoritarian regimes, it is ultimately citizens... continues to march with those who are reaching for freedom around the world. Today, let us remember that our...

  9. Temporal changes in fluid chemistry and energy profiles in the vulcano island hydrothermal system. (United States)

    Rogers, Karyn L; Amend, Jan P; Gurrieri, Sergio


    In June 2003, the geochemical composition of geothermal fluids was determined at 9 sites in the Vulcano hydrothermal system, including sediment seeps, geothermal wells, and submarine vents. Compositional data were combined with standard state reaction properties to determine the overall Gibbs free energy (DeltaG(r) ) for 120 potential lithotrophic and heterotrophic reactions. Lithotrophic reactions in the H-O-N-S-C-Fe system were considered, and exergonic reactions yielded up to 120 kJ per mole of electrons transferred. The potential for heterotrophy was characterized by energy yields from the complete oxidation of 6 carboxylic acids- formic, acetic, propanoic, lactic, pyruvic, and succinic-with the following redox pairs: O(2)/H(2)O, SO(4) (2)/H(2)S, NO(3) ()/NH(4) (+), S(0)/H(2)S, and Fe(3)O(4)/Fe(2+). Heterotrophic reactions yielded 6-111 kJ/mol e(). Energy yields from both lithotrophic and heterotrophic reactions were highly dependent on the terminal electron acceptor (TEA); reactions with O(2) yielded the most energy, followed by those with NO(3) (), Fe(III), SO(4) (2), and S(0). When only reactions with complete TEA reduction were included, the exergonic lithotrophic reactions followed a similar electron tower. Spatial variability in DeltaG(r) was significant for iron redox reactions, owing largely to the wide range in Fe(2+) and H(+) concentrations. Energy yields were compared to those obtained for samples collected in June 2001. The temporal variations in geochemical composition and energy yields observed in the Vulcano hydrothermal system between 2001 and 2003 were moderate. The largest differences in DeltaG(r) over the 2 years were from iron redox reactions, due to temporal changes in the Fe(2+) and H(+) concentrations. The observed variations in fluid composition across the Vulcano hydrothermal system have the potential to influence not only microbial diversity but also the metabolic strategies of the resident microbial communities.

  10. A Fluid Membrane-Based Soluble Ligand Display System for Live CellAssays

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Jwa-Min; Nair, Pradeep N.; Neve, Richard M.; Gray, Joe W.; Groves, Jay T.


    Cell communication modulates numerous biological processes including proliferation, apoptosis, motility, invasion and differentiation. Correspondingly, there has been significant interest in the development of surface display strategies for the presentation of signaling molecules to living cells. This effort has primarily focused on naturally surface-bound ligands, such as extracellular matrix components and cell membranes. Soluble ligands (e.g. growth factors and cytokines) play an important role in intercellular communications, and their display in a surface-bound format would be of great utility in the design of array-based live cell assays. Recently, several cell microarray systems that display cDNA, RNAi, or small molecules in a surface array format were proven to be useful in accelerating high-throughput functional genetic studies and screening therapeutic agents. These surface display methods provide a flexible platform for the systematic, combinatorial investigation of genes and small molecules affecting cellular processes and phenotypes of interest. In an analogous sense, it would be an important advance if one could display soluble signaling ligands in a surface assay format that allows for systematic, patterned presentation of soluble ligands to live cells. Such a technique would make it possible to examine cellular phenotypes of interest in a parallel format with soluble signaling ligands as one of the display parameters. Herein we report a ligand-modified fluid supported lipid bilayer (SLB) assay system that can be used to functionally display soluble ligands to cells in situ (Figure 1A). By displaying soluble ligands on a SLB surface, both solution behavior (the ability to become locally enriched by reaction-diffusion processes) and solid behavior (the ability to control the spatial location of the ligands in an open system) could be combined. The method reported herein benefits from the naturally fluid state of the supported membrane, which allows

  11. The spring balance: a simple monitoring system for fluid overload during hysteroscopic surgery

    NARCIS (Netherlands)

    Ankum, W. M.; Vonk, J.


    Fluid overload may arise during hysteroscopic surgery, caused by absorption of fluid used to distend the uterus. Continuous monitoring of the fluid balance is required to prevent this serious complication. Commercial equipment does not serve this purpose adequately. We describe a simple solution. We

  12. Economic Freedom and Entrepreneurial Activity

    DEFF Research Database (Denmark)

    Bjørnskov, Christian; Foss, Nicolai Juul

    by differences in economic policy and institutional design. Specifically, we use the measures of economic freedom to ask which elements of economic policy making and the institutional framework that are responsible for the supply of entrepreneurship (our data on entrepreneurship are derived from the Global......While much attention has been devoted to analyzing how the institutional framework and entrepreneurship impact growth, how economic policy and institutional design affect entrepreneurship appears to be much less analyzed. We try to explain cross-country differences in the level of entrepreneurship...... Entrepreneurship Monitor). The combination of these two datasets is unique in the literature. We find that the size of government is negatively correlated with entrepreneurial activity but that sound money is positively correlated with entrepreneurial activity. Other measures of economic freedom...

  13. A Note on an Analytic Solution for an Incompressible Fluid-Conveying Pipeline System

    Directory of Open Access Journals (Sweden)

    Vincent O. S. Olunloyo


    Full Text Available This paper presents an integral transform analytic solution to the equations governing a fluid-conveying pipeline segment where a gyroscopic or Coriolis force effect is taken into consideration. The mathematical model idealizes a segment of the pipeline as an elastic beam conveying an incompressible fluid. It is clearly shown that when such a system is supported at both ends and in a free motion, the Coriolis force dissipates no energy (or simply does not work as it generates conjugate complex vibratory components for all flow velocities. It is demonstrated that the modal natural frequencies can be computed from the algebraic products of the complex frequency pairs. Clearly, the patterns of the characteristics of the system’s natural frequencies are seen partly when the real and imaginary components are plotted, as widely seen in the literature. Nonetheless, results from this study revealed that a continuity profile exists to connect the subcritical, critical, and postcritical vibratory behaviours when the absolute values are plotted for any velocity. In the meantime, the efficacy and versatility of this method against the usual assumed spatial or temporal modal solutions are demonstrated by confirming the predictions and validity of results of earlier workers such as Paidoussis, Ziegler, and others where pre- and postdivergence behaviours are exhibited.

  14. [Changes in cerebrospinal fluid in patients with tuberculosis of the central nervous system]. (United States)

    Jedrychowski, Michał; Garlicki, Aleksander


    The aim of the study was to analyze the parameters of the cerebrospinal fluid in patients with tuberculosis of the central nervous system confirmed by culture or molecular methods, in comparison to patients without such confirmation. The analysis of medical documentation of 13 patients with CNS tuberculosis, 10 male and 3 female who were hospitalized at the Clinic of Infectious Diseases in Kraków in years 2001-2006 was performed. Following parameters of the cerebrospinal fluid were taken into account in both groups of patients: cytologic analysis, protein, glucose and chloride concentration. Statistical analysis was done using the non-parametric Mann-Whitney U test. The only parameter for which statistically significant difference between the two groups of patients was found was the level of glucose in CSF (p<0.05). Lower glucose concentration was observed in the group with etiologically confirmed CNS tuberculosis. Moreover additional localisation of tuberculosis was observed in this group of patients. Introduction of the molecular biology methods in diagnosis allowed to detect the etiologic factor more often.

  15. Freedom, License and A.S. Neill. (United States)

    Barrett, Richard


    Attempts to unravel some of the confusion which has arisen over theoretical and actual freedom at A.S. Neill's alternative school in England, Summerhill. An overview of the topic of freedom is offered, based on contrasting theories of freedom in "On Being Free," by Firthjof Bergmann (University of Notre Dame Press, 1977). (DB)

  16. Development as Freedom - And As What Else?

    NARCIS (Netherlands)

    D.R. Gasper (Des); I.P. van Staveren (Irene)


    markdownabstractAbstract To what extent can Amartya Sen’s ideas on freedom, especially his conceptualization of development as freedom, enrich feminist economics? Sen’s notion of freedom (as the capability to achieve valued ends) has many attractions and provides important opportunities to

  17. Development as Freedom. And as What Else?

    NARCIS (Netherlands)

    Gasper, D.; Staveren, I.P. van


    To what extent can Amartya Sen’s ideas on freedom, especially his conceptualization of development as freedom, enrich feminist economics? Sen’s notion of freedom (as the capability to achieve valued ends) has many attractions and provides important opportunities to analyze gender inequalities. At

  18. Development as Freedom : And as What Else?

    NARCIS (Netherlands)

    Staveren, I.P. van; Gasper, D.


    To what extent can Amartya Sen’s ideas on freedom, especially his conceptualization of development as freedom, enrich feminist economics? Sen’s notion of freedom (as the capability to achieve valued ends) has many attractions and provides important opportunities to analyze gender inequalities. At

  19. Individual Freedom and Institutional Frameworks in Development (United States)

    Allen, Nicholas


    In this article I explore Amartya Sen's contention that individual freedom represents both the objective of development and the means through which development is to take place. Examining the conceptualisation of freedom central to Sen's capability approach, I distinguish between two notions of freedom, autonomy and agency, where the former…

  20. Development as Freedom. And as What Else?

    NARCIS (Netherlands)

    Gasper, D.; Staveren, I.P. van


    To what extent can Amartya Sen’s ideas on freedom, especially his conceptualization of development as freedom, enrich feminist economics? Sen’s notion of freedom (as the capability to achieve valued ends) has many attractions and provides important opportunities to analyze gender inequalities. At

  1. 3 CFR - Freedom of Information Act (United States)


    ... 3 The President 1 2010-01-01 2010-01-01 false Freedom of Information Act Presidential Documents Other Presidential Documents Memorandum of January 21, 2009 Freedom of Information Act Memorandum for... disinfectants.” In our democracy, the Freedom of Information Act (FOIA), which encourages accountability through...

  2. Fluid dynamics simulations of a fuel processing system; Stroemungsmechanische Modellierung eines Brenngaserzeugungssystems

    Energy Technology Data Exchange (ETDEWEB)

    Scharf, Florian


    The present thesis deals with the topic of the complete fluid dynamic modelling of the key components of a fuel processing system and based on it the development of the next generation reactors. Fuel cell auxilliary power units enable an energy efficient power generation for mobile applications with higher on-board power consumption. Enabling the operation of the fuel cell with the available middle-destillate on-board, the fuel is transformed to an hydrogen-rich gas in a fuel processing system consisting of the key components autothermal reformer, water-shift reactor and catalytic burner. The modules of the fuel processing system are thereby integrated within the reactors to obtain a lightweighted and compact overall system. The complete numerical description of theses systems are based on chemical-reaction models, vaporization models of fuel and water in the integrated reactant treatment and as well on models for the integrated heat-exchanger. The strong interaction between the single reactor zones require therefore modelling of the key components as an overall reactor system. The methodology of the present thesis is based on a tight integration of CFD simulations with experimental analysis and the construction of the reactors. The results of carried out prototype testings, post-mortem-analysis and laboratory experiments are taken as basis for the CFD modelling and the reactor construction. As numerical tool for fluid dynamic modelling the CFD software FLUENT was used. In the context of this thesis the CFD modelling library was extended with the purpose of the complete description of key components in the CFD overall model. In these CFD overall models the thermal interactions between the reactor zones as well as the influence of the pulsating fuel injection and the chemical reactions are taken into account. For this purpose a similarity theoretical CFD modell of the pulsating fuel injection was generated based on results from prototype testings and high

  3. Entropy production in a fluid-solid system far from thermodynamic equilibrium. (United States)

    Chung, Bong Jae; Ortega, Blas; Vaidya, Ashwin


    The terminal orientation of a rigid body in a moving fluid is an example of a dissipative system, out of thermodynamic equilibrium and therefore a perfect testing ground for the validity of the maximum entropy production principle (MaxEP). Thus far, dynamical equations alone have been employed in studying the equilibrium states in fluid-solid interactions, but these are far too complex and become analytically intractable when inertial effects come into play. At that stage, our only recourse is to rely on numerical techniques which can be computationally expensive. In our past work, we have shown that the MaxEP is a reliable tool to help predict orientational equilibrium states of highly symmetric bodies such as cylinders, spheroids and toroidal bodies. The MaxEP correctly helps choose the stable equilibrium in these cases when the system is slightly out of thermodynamic equilibrium. In the current paper, we expand our analysis to examine i) bodies with fewer symmetries than previously reported, for instance, a half-ellipse and ii) when the system is far from thermodynamic equilibrium. Using two-dimensional numerical studies at Reynolds numbers ranging between 0 and 14, we examine the validity of the MaxEP. Our analysis of flow past a half-ellipse shows that overall the MaxEP is a good predictor of the equilibrium states but, in the special case of the half-ellipse with aspect ratio much greater than unity, the MaxEP is replaced by the Min-MaxEP, at higher Reynolds numbers when inertial effects come into play. Experiments in sedimentation tanks and with hinged bodies in a flow tank confirm these calculations.

  4. Review on Applications of NanoFluids used in Vapour Compression Refrigeration System for Cop Enhancement (United States)

    Veera Raghavalu, K.; Govindha Rasu, N.


    The present research paper focuses on the use of Nano additive refrigerants in vapor compression refrigeration system (VCRS) because of their amazing development during Thermo Physical along with heat transfer potential to improve the coefficient of performance (COP) and reliability of refrigeration system. Furthermore, challenges and future instructions of performance enhancement of VCRS using Nano additive refrigerants were presented. Lubricant oil is essential in the entire vapour compression refrigeration systems, mostly for the efficient function of the compressor. But, some assign of the oil is entire the cycle oil circulates with the refrigerant. Presently, an assortment of investigation is going on in the field of the Nano-particles like metals, oxides, carbon Nano-tubes or carbides. Nano-lubricants are unique type of Nano-fluids which are varieties of Nano-particles, lubricants and have a wide variety in the fields of refrigeration systems. This paper, has been done on the application of Nano-particles balanced in lubricating oils of refrigerating systems are reviewed. The aim of this investigation is to study and find which type of lubricant oil works better with Nano-particles in the area of refrigeration. From the review of literature, it has been observed that Nano-particles mixed with mineral oil gives enhanced results than polyolester (POE) oil.

  5. Fluid Mechanics and Fluid Power (FMFP)

    Indian Academy of Sciences (India)

    Amitabh Bhattacharya

    of renewable energy (e.g., via wind, hydrokinetic generators), creating low-cost healthcare (e.g., via point-of-care medical testing) and improvement of energy efficiency of fluid power systems, depends on improving our understanding of Fluid. Mechanics. Fluids are ubiquitous in both nature and technological applications, ...

  6. 77 FR 7243 - Proposed Information Collection (Operation Enduring Freedom/Operation Iraqi Freedom Veterans... (United States)


    ... AFFAIRS Proposed Information Collection (Operation Enduring Freedom/ Operation Iraqi Freedom Veterans... ``OMB Control No. 2900-0728.'' SUPPLEMENTARY INFORMATION: Title: Operation Enduring Freedom/Operation Iraqi Freedom Veterans Health Needs Assessment, VA Form 10-21091. OMB Control Number: 2900-0728. Type of...

  7. System and method for confining an object to a region of fluid flow having a stagnation point (United States)

    Schroeder, Charles M. (Inventor); Shaqfeh, Eric S. G. (Inventor); Babcock, Hazen P. (Inventor); Chu, Steven (Inventor)


    A device for confining an object to a region proximate to a fluid flow stagnation point includes one or more inlets for carrying the fluid into the region, one or more outlets for carrying the fluid out of the region, and a controller, in fluidic communication with the inlets and outlets, for adjusting the motion of the fluid to produce a stagnation point in the region, thereby confining the object to the region. Applications include, for example, prolonged observation of the object, manipulation of the object, etc. The device optionally may employ a feedback control mechanism, a sensing apparatus (e.g., for imaging), and a storage medium for storing, and a computer for analyzing and manipulating, data acquired from observing the object. The invention further provides methods of using such a device and system in a number of fields, including biology, chemistry, physics, material science, and medical science.

  8. Feeding-dependent activation of enteric cells and sensory neurons by lymphatic fluid: evidence for a neurolymphocrine system. (United States)

    Poole, Daniel P; Lee, Mike; Tso, Patrick; Bunnett, Nigel W; Yo, Sek Jin; Lieu, TinaMarie; Shiu, Amy; Wang, Jen-Chywan; Nomura, Daniel K; Aponte, Gregory W


    Lymphatic fluid is a plasma filtrate that can be viewed as having biological activity through the passive accumulation of molecules from the interstitial fluid. The possibility that lymphatic fluid is part of an active self-contained signaling process that parallels the endocrine system, through the activation of G-protein coupled receptors (GPCR), has remained unexplored. We show that the GPCR lysophosphatidic acid 5 (LPA5) is found in sensory nerve fibers expressing calcitonin gene-related peptide (CGRP) that innervate the lumen of lymphatic lacteals and enteric nerves. Using LPA5 as a model for nutrient-responsive GPCRs present on sensory nerves, we demonstrate that dietary protein hydrolysate (peptone) can induce c-Fos expression in enterocytes and nerves that express LPA5. Mesenteric lymphatic fluid (MLF) mobilizes intracellular calcium in cell models expressing LPA5 upon feeding in a time- and dose-dependent manner. Primary cultured neurons of the dorsal root ganglia expressing CGRP are activated by MLF, which is enhanced upon LPA5 overexpression. Activation is independent of the known LPA5 agonists, lysophosphatidic acid and farnesyl pyrophosphate. These data bring forth a pathway for the direct stimulation of sensory nerves by luminal contents and interstitial fluid. Thus, by activating LPA5 on sensory nerves, MLF provides a means for known and yet to be identified constituents of the interstitial fluid to act as signals to comprise a "neurolymphocrine" system.

  9. Generalized Fluid System Simulation Program, Version 5.0-Educational. Supplemental Information for NASA/TM-2011-216470. Supplement (United States)

    Majumdar, A. K.


    The Generalized Fluid System Simulation Program (GFSSP) is a finite-volume based general-purpose computer program for analyzing steady state and time-dependent flow rates, pressures, temperatures, and concentrations in a complex flow network. The program is capable of modeling real fluids with phase changes, compressibility, mixture thermodynamics, conjugate heat transfer between solid and fluid, fluid transients, pumps, compressors and external body forces such as gravity and centrifugal. The thermofluid system to be analyzed is discretized into nodes, branches, and conductors. The scalar properties such as pressure, temperature, and concentrations are calculated at nodes. Mass flow rates and heat transfer rates are computed in branches and conductors. The graphical user interface allows users to build their models using the point, drag and click method; the users can also run their models and post-process the results in the same environment. The integrated fluid library supplies thermodynamic and thermo-physical properties of 36 fluids and 21 different resistance/source options are provided for modeling momentum sources or sinks in the branches. This Technical Memorandum illustrates the application and verification of the code through 12 demonstrated example problems. This supplement gives the input and output data files for the examples.

  10. Medical Logistics Lessons Observed During Operations Enduring Freedom and Iraqi Freedom. (United States)

    Dole, Mark J; Kissane, Jonathan M


    Medical Logistics (MEDLOG) is a function of the Army's integrated System for Health that provides the medical products and specialized logistics services required to deliver health protection and care under all operational conditions. In unified land operations, MEDLOG is an inherent function of Health Service Support (HSS), which also includes casualty care and medical evacuation. This paper focuses on a few key lessons observed during Operations Enduring Freedom and Iraqi Freedom with direct implications for the support of HSS in future operations as envisioned in the Army Operating Concept and the Joint Concept for Health Services. It also examines a few key enablers that helped mitigate these challenges that are not yet fully acknowledged in Army Medical Department doctrine, policy, and planning.

  11. Analytical Electron Microscopy for Characterization of Fluid or Semi-Solid Multiphase Systems Containing Nanoparticulate Material

    Directory of Open Access Journals (Sweden)

    Nadejda B. Matsko


    Full Text Available The analysis of nanomaterials in pharmaceutical or cosmetic preparations is an important aspect both in formulation development and quality control of marketed products. Despite the increased popularity of nanoparticulate compounds especially in dermal preparations such as emulsions, methods and protocols of analysis for the characterization of such systems are scarce. This work combines an original sample preparation procedure along with different methods of analytical electron microscopy for the comprehensive analysis of fluid or semi-solid dermal preparations containing nanoparticulate material. Energy-filtered transmission electron microscopy, energy-dispersive X-ray spectroscopy, electron energy loss spectroscopy and high resolution imaging were performed on model emulsions and a marketed product to reveal different structural aspects of both the emulsion bulk phase and incorporated nanosized material. An innovative analytical approach for the determination of the physical stability of the emulsion under investigation is presented. Advantages and limitations of the employed analytical imaging techniques are highlighted.

  12. Carbon dioxide as working fluid for medium and high-temperature concentrated solar thermal systems

    Directory of Open Access Journals (Sweden)

    Van Duong


    Full Text Available This paper explores the benefits and drawbacks of using carbon dioxide in solar thermal systems at medium and high operating temperatures. For medium temperatures, application of CO2 in non-imaging-optics based compound parabolic concentrators (CPC combined with evacuated-tube collectors is studied. These collectors have been shown to obtain efficiencies higher than 40% operating at around 200℃ without the need of tracking. Validated numerical models of external compound parabolic concentrators (XCPCs are used to simulate their performance using CO2 as working fluid. For higher temperatures, a mathematical model is implemented to analyze the operating performance of a parabolic trough solar collector (PTC using CO2 at temperatures between 100℃ and 600℃.

  13. Performance Evaluation of Strain Gauge Printed Using Automatic Fluid Dispensing System on Conformal Substrates (United States)

    Khairilhijra Khirotdin, Rd.; Faridzuan Ngadiron, Mohamad; Adzeem Mahadzir, Muhammad; Hassan, Nurhafizzah


    Smart textiles require flexible electronics that can withstand daily stresses like bends and stretches. Printing using conductive inks provides the flexibility required but the current printing techniques suffered from ink incompatibility, limited of substrates to be printed with and incompatible with conformal substrates due to its rigidity and low flexibility. An alternate printing technique via automatic fluid dispensing system is proposed and its performances on printing strain gauge on conformal substrates were evaluated to determine its feasibility. Process parameters studied including printing speed, deposition height, curing time and curing temperature. It was found that the strain gauge is proven functional as expected since different strains were induced when bent on variation of bending angles and curvature radiuses from designated bending fixtures. The average change of resistances were doubled before the strain gauge starts to break. Printed strain gauges also exhibited some excellence elasticity as they were able to resist bending up to 70° angle and 3 mm of curvature radius.

  14. Internal Thermal Control System Hose Heat Transfer Fluid Thermal Expansion Evaluation Test Report (United States)

    Wieland, P. O.; Hawk, H. D.


    During assembly of the International Space Station, the Internal Thermal Control Systems in adjacent modules are connected by jumper hoses referred to as integrated hose assemblies (IHAs). A test of an IHA has been performed at the Marshall Space Flight Center to determine whether the pressure in an IHA filled with heat transfer fluid would exceed the maximum design pressure when subjected to elevated temperatures (up to 60 C (140 F)) that may be experienced during storage or transportation. The results of the test show that the pressure in the IHA remains below 227 kPa (33 psia) (well below the 689 kPa (100 psia) maximum design pressure) even at a temperature of 71 C (160 F), with no indication of leakage or damage to the hose. Therefore, based on the results of this test, the IHA can safely be filled with coolant prior to launch. The test and results are documented in this Technical Memorandum.

  15. Macrophage migration inhibitory factor in cerebrospinal fluid from patients with central nervous system infection

    DEFF Research Database (Denmark)

    Ostergaard, Christian; Benfield, Thomas


    .01). Among patients with purulent meningitis, CSF MIF levels were significantly higher in patients infected with pneumococci as compared to infection due to meningococci (11569 ng/L (8615-21935) vs. 5006 ng/L (1717-10905) respectively, P=0.02), in patients requiring assisted ventilation (10493 ng/L (5961-22725......ABSTRACT: INTRODUCTION: Macrophage Migration Inhibitory Factor (MIF) plays an essential pathophysiological role in septic shock; however, its role in central nervous system infection (CNS) remains to be defined. METHODS: The aim of the present study was to investigate cerebrospinal fluid (CSF......) levels of MIF in 171 patients clinically suspected of having meningitis on admission. Of these, 31 were found to have purulent meningitis with a known aetiology, 20 to have purulent meningitis with an unknown aetiology, 59 to have lymphocytic meningitis, and 11 to have encephalitis, whereas 50 were...

  16. Coagulation and fibrinolysis systems in bronchoalveolar lavage fluid in irradiated lung of rabbits

    International Nuclear Information System (INIS)

    Sawada, Midori


    Pulmonary fibrin deposition suggests the involvement of coagulation and fibrinolysis in pulmonary inflammation. The present study was designed to investigate the alterations of coagulation and fibrinolysis in rabbits that received thoracic irradiation. Serial bronchoalveolar lavage (BAL) was performed after the irradiation, and procoagulant activity (PCA) and tissue plasminogen activator (r-PA) were measured in BAL fluids. PCA increased from 2 to 8 weeks after irradiation with increased number of macrophages and increased PCA per macrophage. T-PA also increased with a significant difference at 4 weeks compared to controls. Although irradiation activated both PCA and t-PA, PCA increased prior to t-PA and the elevation lasted longer. It was concluded that activation of the coagulation system promotes pulmonary fibrin deposition and may contribute to the progression of pulmonary injury. (author)

  17. Benchmark Simulation of Natural Circulation Cooling System with Salt Working Fluid Using SAM

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, K. K.; Scarlat, R. O.; Hu, R.


    Liquid salt-cooled reactors, such as the Fluoride Salt-Cooled High-Temperature Reactor (FHR), offer passive decay heat removal through natural circulation using Direct Reactor Auxiliary Cooling System (DRACS) loops. The behavior of such systems should be well-understood through performance analysis. The advanced system thermal-hydraulics tool System Analysis Module (SAM) from Argonne National Laboratory has been selected for this purpose. The work presented here is part of a larger study in which SAM modeling capabilities are being enhanced for the system analyses of FHR or Molten Salt Reactors (MSR). Liquid salt thermophysical properties have been implemented in SAM, as well as properties of Dowtherm A, which is used as a simulant fluid for scaled experiments, for future code validation studies. Additional physics modules to represent phenomena specific to salt-cooled reactors, such as freezing of coolant, are being implemented in SAM. This study presents a useful first benchmark for the applicability of SAM to liquid salt-cooled reactors: it provides steady-state and transient comparisons for a salt reactor system. A RELAP5-3D model of the Mark-1 Pebble-Bed FHR (Mk1 PB-FHR), and in particular its DRACS loop for emergency heat removal, provides steady state and transient results for flow rates and temperatures in the system that are used here for code-to-code comparison with SAM. The transient studied is a loss of forced circulation with SCRAM event. To the knowledge of the authors, this is the first application of SAM to FHR or any other molten salt reactors. While building these models in SAM, any gaps in the code’s capability to simulate such systems are identified and addressed immediately, or listed as future improvements to the code.


    Directory of Open Access Journals (Sweden)

    Nani Hidayati


    Full Text Available This study attempts to find out conveyed messages in the movie from the realization of the appraisal and narrative structure as well as to describe the use of the Appraisal System to express LaGravenese's (a Attitudes, (bEngagement & (c Graduation towards the main characters in Freedom Writers movie screenplay. Using both quantitative and qualitative descriptive approach for discourse appraisal system analysis, the result of this study reveals several messages of tolerance, earning respect and trust, honor diversity, and striving for success and trust from the realization of Appraisal and Narrative Structure either in the dialogues or monologues of Freedom Writers’ characters. The result from the Appraisal Devices realizing (a Attitudes reveals that LaGravenese likes to express characters’ negative emotion explicitly than implicitly. He likes to express characters’ negative capability than other kinds of Judgments. He appreciates the characters using more Negative Value which denotes that in his opinion, they see each other negatively. (bEngagement used in the screenplay describes that he emphasizes more on characters’ denial towards each other’s opinion and existence with the use of more Disclaim Heterogloss in the screenplay. (cGraduation used in the screenplay describes that the use of more Sharpening Focus indicates he emphasizes on characters’ category boundary more than scaling of intensity. Keywords: Appraisal Devices, Attitude, Engagement, and Graduation.

  19. A Dual-Mode Magnetic-Acoustic System for Monitoring Fluid Intake Behavior in Animals. (United States)

    Sargolzaei, Saman; Elahi, Hassan; Sokoloff, Alan; Ghovanloo, Maysam


    We have developed an unobtrusive magnetic-acoustic fluid intake monitoring (MAFIM) system using a conventional stainless-steel roller-ball nipple to measure licking and drinking behavior in animals. Movements of a small permanent magnetic tracer attached to stainless-steel roller balls that operate as a tongue-actuated valve are sensed by a pair of three-axial magnetometers, and transformed into a time-series indicating the status of the ball (up or down), using a Gaussian mixture model based data-driven classifier. The sounds produced by the rise and fall of the roller balls are also recorded and classified to substantiate the magnetic data by an independent modality for a more robust solution. The operation of the magnetic and acoustic sensors is controlled by an embedded system, communicating via Universal Serial Bus (USB) with a custom-designed user interface, running on a PC. The MAFIM system has been tested in vivo with minipigs, accurately measuring various drinking parameters and licking patterns without constraints imposed by current lick monitoring systems, such as nipple access, animal-nipple contact, animal training, and complex parameter settings.

  20. An automated system for performing continuous viscosity versus temperature measurements of fluids using an Ostwald viscometer (United States)

    Beaulieu, L. Y.; Logan, E. R.; Gering, K. L.; Dahn, J. R.


    An automated system was developed to measure the viscosity of fluids as a function of temperature using image analysis tracking software. An Ostwald viscometer was placed in a three-wall dewar in which ethylene glycol was circulated using a thermal bath. The system collected continuous measurements during both heating and cooling cycles exhibiting no hysteresis. The use of video tracking analysis software greatly reduced the measurement errors associated with measuring the time required for the meniscus to pass through the markings on the viscometer. The stability of the system was assessed by performing 38 consecutive measurements of water at 42.50 ± 0.05 °C giving an average flow time of 87.7 ± 0.3 s. A device was also implemented to repeatedly deliver a constant volume of liquid of 11.00 ± 0.03 ml leading to an average error in the viscosity of 0.04%. As an application, the system was used to measure the viscosity of two Li-ion battery electrolyte solvents from approximately 10 to 40 °C with results showing excellent agreement with viscosity values calculated using Gering's Advanced Electrolyte Model (AEM).

  1. An automated system for performing continuous viscosity versus temperature measurements of fluids using an Ostwald viscometer. (United States)

    Beaulieu, L Y; Logan, E R; Gering, K L; Dahn, J R


    An automated system was developed to measure the viscosity of fluids as a function of temperature using image analysis tracking software. An Ostwald viscometer was placed in a three-wall dewar in which ethylene glycol was circulated using a thermal bath. The system collected continuous measurements during both heating and cooling cycles exhibiting no hysteresis. The use of video tracking analysis software greatly reduced the measurement errors associated with measuring the time required for the meniscus to pass through the markings on the viscometer. The stability of the system was assessed by performing 38 consecutive measurements of water at 42.50 ± 0.05 °C giving an average flow time of 87.7 ± 0.3 s. A device was also implemented to repeatedly deliver a constant volume of liquid of 11.00 ± 0.03 ml leading to an average error in the viscosity of 0.04%. As an application, the system was used to measure the viscosity of two Li-ion battery electrolyte solvents from approximately 10 to 40 °C with results showing excellent agreement with viscosity values calculated using Gering's Advanced Electrolyte Model (AEM).

  2. Facial fluid synthesis for assessment of acne vulgaris using luminescent visualization system through optical imaging and integration of fluorescent imaging system (United States)

    Balbin, Jessie R.; Dela Cruz, Jennifer C.; Camba, Clarisse O.; Gozo, Angelo D.; Jimenez, Sheena Mariz B.; Tribiana, Aivje C.


    Acne vulgaris, commonly called as acne, is a skin problem that occurs when oil and dead skin cells clog up in a person's pores. This is because hormones change which makes the skin oilier. The problem is people really do not know the real assessment of sensitivity of their skin in terms of fluid development on their faces that tends to develop acne vulgaris, thus having more complications. This research aims to assess Acne Vulgaris using luminescent visualization system through optical imaging and integration of image processing algorithms. Specifically, this research aims to design a prototype for facial fluid analysis using luminescent visualization system through optical imaging and integration of fluorescent imaging system, and to classify different facial fluids present in each person. Throughout the process, some structures and layers of the face will be excluded, leaving only a mapped facial structure with acne regions. Facial fluid regions are distinguished from the acne region as they are characterized differently.

  3. Cementing an Implant Crown: A Novel Measurement System Using Computational Fluid Dynamics Approach. (United States)

    Wadhwani, Chandur; Goodwin, Sabine; Chung, Kwok-Hung


    Cementing restorations to implants is a widely used clinical procedure. Little is known about the dynamics of this process. Using a systems approach and advanced computing software modeling this can be investigated virtually. These models require validation against real-life models. The study aims to consider the system effect of a crown, abutment, and cement flow under different conditions and comparing real physical models to virtual computer simulations. A physical model of implant abutments and crowns provided three groups according to abutment screw access modification (n = 9): open (OA), closed (CA), and internal vented (IVA) abutment groups. Crowns were cemented using standardized amounts and site application. Proportion of cement retained within the crown-abutment system was recorded and compared. Differences among groups were identified using analysis of variance (ANOVA) with Tukey's post hoc test (α ≤ 0.05). Three-dimensional multiphysics numerical stimulation software (STAR-CCM+, CD-adapco) with computational fluid dynamics (CFD) approach was applied to a virtual model system of a scanned abutment and crown system. Three-dimensional real-time model simulations of cement and air displacement were produced, evaluating cement application site, speed of crown seating, and abutment modifications. Statistically significant differences in cement retained within the system (p  OA > OCA abutment groups. The CFD virtual simulations followed this trend. Site application and speed of seating also affected cement extrusion and cement marginal infill. Fast crown seating and occlusal cement site application produced air incorporation at the margins. The CFD approach provides a convenient way to evaluate crown-cement-implant abutment systems with respect to cement flow. Preliminary evaluation indicates that the results achieved follow those of a physical actual cement-retained crown-implant abutment study. © 2014 Wiley Periodicals, Inc.

  4. Computational Fluid Dynamics Analysis of Very High Temperature Gas-Cooled Reactor Cavity Cooling System

    Energy Technology Data Exchange (ETDEWEB)

    Frisani, Angelo; Hassan, Yassin A; Ugaz, Victor M


    The design of passive heat removal systems is one of the main concerns for the modular very high temperature gas-cooled reactors (VHTR) vessel cavity. The reactor cavity cooling system (RCCS) is a key heat removal system during normal and off-normal conditions. The design and validation of the RCCS is necessary to demonstrate that VHTRs can survive to the postulated accidents. The computational fluid dynamics (CFD) STAR-CCM+/V3.06.006 code was used for three-dimensional system modeling and analysis of the RCCS. A CFD model was developed to analyze heat exchange in the RCCS. The model incorporates a 180-deg section resembling the VHTR RCCS experimentally reproduced in a laboratory-scale test facility at Texas A&M University. All the key features of the experimental facility were taken into account during the numerical simulations. The objective of the present work was to benchmark CFD tools against experimental data addressing the behavior of the RCCS following accident conditions. Two cooling fluids (i.e., water and air) were considered to test the capability of maintaining the RCCS concrete walls' temperature below design limits. Different temperature profiles at the reactor pressure vessel (RPV) wall obtained from the experimental facility were used as boundary conditions in the numerical analyses to simulate VHTR transient evolution during accident scenarios. Mesh convergence was achieved with an intensive parametric study of the two different cooling configurations and selected boundary conditions. To test the effect of turbulence modeling on the RCCS heat exchange, predictions using several different turbulence models and near-wall treatments were evaluated and compared. The comparison among the different turbulence models analyzed showed satisfactory agreement for the temperature distribution inside the RCCS cavity medium and at the standpipes walls. For such a complicated geometry and flow conditions, the tested turbulence models demonstrated that the

  5. Identification and activity of acetate-assimilating bacteria in diffuse fluids venting from two deep-sea hydrothermal systems. (United States)

    Winkel, Matthias; Pjevac, Petra; Kleiner, Manuel; Littmann, Sten; Meyerdierks, Anke; Amann, Rudolf; Mußmann, Marc


    Diffuse hydrothermal fluids often contain organic compounds such as hydrocarbons, lipids, and organic acids. Microorganisms consuming these compounds at hydrothermal sites are so far only known from cultivation-dependent studies. To identify potential heterotrophs without prior cultivation, we combined microbial community analysis with short-term incubations using (13)C-labeled acetate at two distinct hydrothermal systems. We followed cell growth and assimilation of (13)C into single cells by nanoSIMS combined with fluorescence in situ hybridization (FISH). In 55 °C-fluids from the Menez Gwen hydrothermal system/Mid-Atlantic Ridge, a novel epsilonproteobacterial group accounted for nearly all assimilation of acetate, representing the first aerobic acetate-consuming member of the Nautiliales. In contrast, Gammaproteobacteria dominated the (13) C-acetate assimilation in incubations of 37 °C-fluids from the back-arc hydrothermal system in the Manus Basin/Papua New Guinea. Here, 16S rRNA gene sequences were mostly related to mesophilic Marinobacter, reflecting the high content of seawater in these fluids. The rapid growth of microorganisms upon acetate addition suggests that acetate consumers in diffuse fluids are copiotrophic opportunists, which quickly exploit their energy sources, whenever available under the spatially and temporally highly fluctuating conditions. Our data provide first insights into the heterotrophic microbial community, catalyzing an under-investigated part of microbial carbon cycling at hydrothermal vents. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  6. Present State and Future Developments in Mechatronics and it's Influence on Fluid Power Systems

    DEFF Research Database (Denmark)

    Christensen, Georg Kronborg; Zhou, Jianjun; Conrad, Finn


    with electronics, software and mechanics. This synergetic integration is often called Mechatronics.The topic which is rather widespread will be treated in three sections: I) General overview of mechatronics and fluid power. In this section the general trends of mechatronics in fluid power is considered by relating...... trends in the neighbouring fields of software and electronic hardware to fluid power developments. II) Mechatronic case stories from IKS In this section the results of a conceptual design study : "Design of a frequency converter based hydraulic power supply" is presented together with a more detailed......This paper tries to sketch the outlines for the future of : Fluid Power Control under the influence of the rapid advances of computer hardware and software technologies. The influences, when they improve the performance of fluid power, are seen as a synergetic integration of fluid power...

  7. Thermodynamics investigation of a solar power system integrated oil and molten salt as heat transfer fluids

    International Nuclear Information System (INIS)

    Liu, Qibin; Bai, Zhang; Sun, Jie; Yan, Yuejun; Gao, Zhichao; Jin, Hongguang


    Highlights: • A new concentrating solar power system with a dual-solar field is proposed. • The superheated steam with more than 773 K is produced. • The performances of the proposed system are demonstrated. • The economic feasibility of the proposed system is validated. - Abstract: In this paper, a new parabolic trough solar power system that incorporates a dual-solar field with oil and molten salt as heat transfer fluids (HTFs) is proposed to effectively utilize the solar energy. The oil is chosen as a HTF in the low temperature solar field to heat the feeding water, and the high temperature solar field uses molten salt to superheat the steam that the temperature is higher than 773 K. The produced superheated steam enters a steam turbine to generate power. Energy analysis and exergy analysis of the system are implemented to evaluate the feasibility of the proposed system. Under considerations of variations of solar irradiation, the on-design and off-design thermodynamic performances of the system and the characteristics are investigated. The annual average solar-to-electric efficiency and the nominal efficiency under the given condition for the proposed solar thermal power generation system reach to 15.86% and 22.80%, which are higher than the reference system with a single HTF. The exergy losses within the solar heat transfer process of the proposed system are reduced by 7.8% and 45.23% compared with the solar power thermal systems using oil and molten salt as HTFs, respectively. The integrated approach with oil and molten salt as HTFs can make full use of the different physical properties of the HTFs, and optimize the heat transfer process between the HTFs and the water/steam. The exergy loss in the water evaporation and superheated process are reduced, the system efficiency and the economic performance are improved. The research findings provide a new approach for the improvement of the performances of solar thermal power plants.

  8. Precision Magnetic Bearing Six Degree of Freedom Stage (United States)

    Williams, M. E.; Trumper, David L.


    Magnetic bearings are capable of applying force and torque to a suspended object without rigidly constraining any degrees of freedom. Additionally, the resolution of magnetic bearings is limited only by sensors and control, and not by the finish of a bearing surface. For these reasons, magnetic bearings appear to be ideal for precision wafer positioning in lithography systems. To demonstrate this capability a linear magnetic bearing has been constructed which uses variable reluctance actuators to control the motion of a 14.5 kg suspended platen in five degrees of freedom. A Lorentz type linear motor of our own design and construction is used to provide motion and position control in the sixth degree of freedom. The stage performance results verify that the positioning requirements of photolithography can be met with a system of this type. This paper describes the design, control, and performance of the linear magnetic bearing.

  9. Evaluation of CO2-Fluid-Rock Interaction in Enhanced Geothermal Systems: Field-Scale Geochemical Simulations

    Directory of Open Access Journals (Sweden)

    Feng Pan


    Full Text Available Recent studies suggest that using supercritical CO2 (scCO2 instead of water as a heat transmission fluid in Enhanced Geothermal Systems (EGS may improve energy extraction. While CO2-fluid-rock interactions at “typical” temperatures and pressures of subsurface reservoirs are fairly well known, such understanding for the elevated conditions of EGS is relatively unresolved. Geochemical impacts of CO2 as a working fluid (“CO2-EGS” compared to those for water as a working fluid (H2O-EGS are needed. The primary objectives of this study are (1 constraining geochemical processes associated with CO2-fluid-rock interactions under the high pressures and temperatures of a typical CO2-EGS site and (2 comparing geochemical impacts of CO2-EGS to geochemical impacts of H2O-EGS. The St. John’s Dome CO2-EGS research site in Arizona was adopted as a case study. A 3D model of the site was developed. Net heat extraction and mass flow production rates for CO2-EGS were larger compared to H2O-EGS, suggesting that using scCO2 as a working fluid may enhance EGS heat extraction. More aqueous CO2 accumulates within upper- and lower-lying layers than in the injection/production layers, reducing pH values and leading to increased dissolution and precipitation of minerals in those upper and lower layers. Dissolution of oligoclase for water as a working fluid shows smaller magnitude in rates and different distributions in profile than those for scCO2 as a working fluid. It indicates that geochemical processes of scCO2-rock interaction have significant effects on mineral dissolution and precipitation in magnitudes and distributions.

  10. Numerical solution of fluid-structure interaction in piping systems by Glimm's method (United States)

    Gomes da Rocha, Rogerio; Bastos de Freitas Rachid, Felipe


    This work presents a numerical procedure for obtaining approximated solutions for one-dimensional fluid-structure interaction (FSI) models, which are used in transient analyses of liquid-filled piping systems. The FSI model considered herein is formed by a system of hyperbolic partial differential equations and describes, simultaneously, pressure waves propagating in the liquid as well as axial, shear and bending waves traveling in the pipe walls. By taking advantage of an operator splitting technique, the flux term is split away from the source one, giving rise to a sequence of simpler problems formed by a set of homogeneous hyperbolic differential equations and by a set of ordinary differential equations in time. The numerical procedure is constructed by advancing in time sequentially through these sets of equations by employing Glimm's method and Gear's stiff method, respectively. To implement Glimm's method, analytical solutions for the associated Riemann problems are presented. The boundary conditions are properly accounted for in Glimm's method by formulating and analytically solving suitable (non-classical) Riemann problems for the pipe's ends. The proposed numerical procedure is used to obtain numerical approximations for the well-known eight-equation FSI model for two closed piping systems, in which transients are generated by the impact of a rod onto one of the ends. The obtained numerical results are compared with experimental data available in the literature and very good agreement is found.

  11. Computer Simulations and Theoretical Studies of Complex Systems: from complex fluids to frustrated magnets (United States)

    Choi, Eunsong

    Computer simulations are an integral part of research in modern condensed matter physics; they serve as a direct bridge between theory and experiment by systemactically applying a microscopic model to a collection of particles that effectively imitate a macroscopic system. In this thesis, we study two very differnt condensed systems, namely complex fluids and frustrated magnets, primarily by simulating classical dynamics of each system. In the first part of the thesis, we focus on ionic liquids (ILs) and polymers--the two complementary classes of materials that can be combined to provide various unique properties. The properties of polymers/ILs systems, such as conductivity, viscosity, and miscibility, can be fine tuned by choosing an appropriate combination of cations, anions, and polymers. However, designing a system that meets a specific need requires a concrete understanding of physics and chemistry that dictates a complex interplay between polymers and ionic liquids. In this regard, molecular dynamics (MD) simulation is an efficient tool that provides a molecular level picture of such complex systems. We study the behavior of Poly (ethylene oxide) (PEO) and the imidazolium based ionic liquids, using MD simulations and statistical mechanics. We also discuss our efforts to develop reliable and efficient classical force-fields for PEO and the ionic liquids. The second part is devoted to studies on geometrically frustrated magnets. In particular, a microscopic model, which gives rise to an incommensurate spiral magnetic ordering observed in a pyrochlore antiferromagnet is investigated. The validation of the model is made via a comparison of the spin-wave spectra with the neutron scattering data. Since the standard Holstein-Primakoff method is difficult to employ in such a complex ground state structure with a large unit cell, we carry out classical spin dynamics simulations to compute spin-wave spectra directly from the Fourier transform of spin trajectories. We

  12. Machiavelli: Ambition, Freedom and Justice

    Directory of Open Access Journals (Sweden)

    Alicia Villar Ezcurra


    Full Text Available This article tackles the anthropological conception of Machiavelli, mainly taken from the Discourses on the First Decade of Titus Livius in which stands out the identity of human passions and the importance of its understanding to reach political knowledge. Machiavelli considers that the human being is malleable in such a way that a passion can be fought and compensated by another one. From this perspective, is analysed the role of ambition and freedom both as a source of confrontation and degeneration and as an incentive to achieve the most important goals.

  13. Development and Use of Engineering Standards for Computational Fluid Dynamics for Complex Aerospace Systems (United States)

    Lee, Hyung B.; Ghia, Urmila; Bayyuk, Sami; Oberkampf, William L.; Roy, Christopher J.; Benek, John A.; Rumsey, Christopher L.; Powers, Joseph M.; Bush, Robert H.; Mani, Mortaza


    Computational fluid dynamics (CFD) and other advanced modeling and simulation (M&S) methods are increasingly relied on for predictive performance, reliability and safety of engineering systems. Analysts, designers, decision makers, and project managers, who must depend on simulation, need practical techniques and methods for assessing simulation credibility. The AIAA Guide for Verification and Validation of Computational Fluid Dynamics Simulations (AIAA G-077-1998 (2002)), originally published in 1998, was the first engineering standards document available to the engineering community for verification and validation (V&V) of simulations. Much progress has been made in these areas since 1998. The AIAA Committee on Standards for CFD is currently updating this Guide to incorporate in it the important developments that have taken place in V&V concepts, methods, and practices, particularly with regard to the broader context of predictive capability and uncertainty quantification (UQ) methods and approaches. This paper will provide an overview of the changes and extensions currently underway to update the AIAA Guide. Specifically, a framework for predictive capability will be described for incorporating a wide range of error and uncertainty sources identified during the modeling, verification, and validation processes, with the goal of estimating the total prediction uncertainty of the simulation. The Guide's goal is to provide a foundation for understanding and addressing major issues and concepts in predictive CFD. However, this Guide will not recommend specific approaches in these areas as the field is rapidly evolving. It is hoped that the guidelines provided in this paper, and explained in more detail in the Guide, will aid in the research, development, and use of CFD in engineering decision-making.

  14. MicroRNAs in Cerebrospinal Fluid as Potential Biomarkers for Parkinson's Disease and Multiple System Atrophy. (United States)

    Marques, Tainá M; Kuiperij, H Bea; Bruinsma, Ilona B; van Rumund, Anouke; Aerts, Marjolein B; Esselink, Rianne A J; Bloem, Bas R; Verbeek, Marcel M


    Parkinson's disease (PD) and multiple system atrophy (MSA) are both part of the spectrum of neurodegenerative movement disorders and α-synucleinopathies with overlap of symptoms especially at early stages of the disease but with distinct disease progression and responses to dopaminergic treatment. Therefore, having biomarkers that specifically classify patients, which could discriminate PD from MSA, would be very useful. MicroRNAs (miRNAs) regulate protein translation and are observed in biological fluids, including cerebrospinal fluid (CSF), and may therefore have potential as biomarkers of disease. The aim of our study was to determine if miRNAs in CSF could be used as biomarkers for either PD or MSA. Using quantitative PCR (qPCR), we evaluated expression levels of 10 miRNAs in CSF patient samples from PD (n = 28), MSA (n = 17), and non-neurological controls (n = 28). We identified two miRNAs (miR-24 and miR-205) that distinguished PD from controls and four miRNAs that differentiated MSA from controls (miR-19a, miR-19b, miR-24, and miR-34c). Combinations of miRNAs accurately discriminated either PD (area under the curve (AUC) = 0.96) or MSA (AUC = 0.86) from controls. In MSA, we also observed that miR-24 and miR-148b correlated with cerebellar ataxia symptoms, suggesting that these miRNAs are involved in cerebellar degeneration in MSA. Our findings support the potential of miRNA panels as biomarkers for movement disorders and may provide more insights into the pathological mechanisms related to these disorders.

  15. Fluid dynamic transient analysis

    International Nuclear Information System (INIS)

    Vilhena Reigosa, R. de


    This paper describes the methodology adopted at NUCLEN for the fluid dynamic analyses for ANGRA 2. The fluid dynamic analysis allows, through computer codes to simulate and quantify the loads resulting from fluid dynamic transients caused by postulated ruptures or operational transients, in the piping of the safety systems and of the important operational systems. (author)

  16. Quantum Theory of Layer Vibration in the Layer-Structured Fermi Fluid : Nuclear Physics


    Koichi, TAKAHASHI; Tatsuo, TSUKAMOTO; Department of Liberal Arts, Tohoku Gakuin University; Department of Liberal Arts, Tohoku Gakuin University


    A method of introducing collective motion into the layered Fermi fluid (LFF) is discussed by concentrating on layer vibrations. By the random phase approximation (RPA), the original dynamical degrees of freedom of particles are separated into collective modes (CMs), uncorrelated (harmonic) oscillator modes (UOMs) and two-dimensional (2D) motions of particles within layers, which leads to a subband structure of particle spectrum. Transverse CMs cause the system's instability in case the intera...

  17. High degree-of-freedom dynamic manipulation (United States)

    Murphy, Michael P.; Stephens, Benjamin; Abe, Yeuhi; Rizzi, Alfred A.


    The creation of high degree of freedom dynamic mobile manipulation techniques and behaviors will allow robots to accomplish difficult tasks in the field. We are investigating the use of the body and legs of legged robots to improve the strength, velocity, and workspace of an integrated manipulator to accomplish dynamic manipulation. This is an especially challenging task, as all of the degrees of freedom are active at all times, the dynamic forces generated are high, and the legged system must maintain robust balance throughout the duration of the tasks. To accomplish this goal, we are utilizing trajectory optimization techniques to generate feasible open-loop behaviors for our 28 dof quadruped robot (BigDog) by planning the trajectories in a 13 dimensional space. Covariance Matrix Adaptation techniques are utilized to optimize for several criteria such as payload capability and task completion speed while also obeying constraints such as torque and velocity limits, kinematic limits, and center of pressure location. These open-loop behaviors are then used to generate feed-forward terms, which are subsequently used online to improve tracking and maintain low controller gains. Some initial results on one of our existing balancing quadruped robots with an additional human-arm-like manipulator are demonstrated on robot hardware, including dynamic lifting and throwing of heavy objects 16.5kg cinder blocks, using motions that resemble a human athlete more than typical robotic motions. Increased payload capacity is accomplished through coordinated body motion.

  18. Freedom: Toward an Integration of the Counseling Profession (United States)

    Hanna, Fred J.


    Freedom is presented as an overarching paradigm that may align and bring together the counseling profession's diverse counseling theories and open a doorway to a new generation of counseling techniques. Freedom is defined and discussed in terms of its 4 modalities: freedom from, freedom to, freedom with, and freedom for. The long-standing problem…

  19. Biofluid mechanics of special organs and the issue of system control. Sixth International Bio-Fluid Mechanics Symposium and Workshop, March 28-30, 2008 Pasadena, California. (United States)

    Zamir, Mair; Moore, James E; Fujioka, Hideki; Gaver, Donald P


    In the field of fluid flow within the human body, focus has been placed on the transportation of blood in the systemic circulation since the discovery of that system; but, other fluids and fluid flow phenomena pervade the body. Some of the most fascinating fluid flow phenomena within the human body involve fluids other than blood and a service other than transport--the lymphatic and pulmonary systems are two striking examples. While transport is still involved in both cases, this is not the only service which they provide and blood is not the only fluid involved. In both systems, filtration, extraction, enrichment, and in general some "treatment" of the fluid itself is the primary function. The study of the systemic circulation has also been conventionally limited to treating the system as if it were an open-loop system governed by the laws of fluid mechanics alone, independent of physiological controls and regulations. This implies that system failures can be explained fully in terms of the laws of fluid mechanics, which of course is not the case. In this paper we examine the clinical implications of these issues and of the special biofluid mechanics issues involved in the lymphatic and pulmonary systems.

  20. Cerebrospinal fluid HIV infection and pleocytosis: Relation to systemic infection and antiretroviral treatment

    Directory of Open Access Journals (Sweden)

    Petropoulos Christos J


    Full Text Available Abstract Background Central nervous system (CNS exposure to HIV is a universal facet of systemic infection. Because of its proximity to and shared barriers with the brain, cerebrospinal fluid (CSF provides a useful window into and model of human CNS HIV infection. Methods Prospective study of the relationships of CSF to plasma HIV RNA, and the effects of: 1 progression of systemic infection, 2 CSF white blood cell (WBC count, 3 antiretroviral therapy (ART, and 4 neurological performance. One hundred HIV-infected subjects were cross-sectionally studied, and 28 were followed longitudinally after initiating or changing ART. Results In cross-sectional analysis, HIV RNA levels were lower in CSF than plasma (median difference 1.30 log10 copies/mL. CSF HIV viral loads (VLs correlated strongly with plasma VLs and CSF WBC counts. Higher CSF WBC counts associated with smaller differences between plasma and CSF HIV VL. CSF VL did not correlate with blood CD4 count, but CD4 counts In subjects starting ART, those with lower CD4 counts had slower initial viral decay in CSF than in plasma. In all subjects, including five with persistent plasma viremia and four with new-onset ADC, CSF HIV eventually approached or reached the limit of viral detection and CSF pleocytosis resolved. Conclusion CSF HIV infection is common across the spectrum of infection and is directly related to CSF pleocytosis, though whether the latter is a response to or a contributing cause of CSF infection remains uncertain. Slowing in the rate of CSF response to ART compared to plasma as CD4 counts decline indicates a changing character of CSF infection with systemic immunological progression. Longer-term responses indicate that CSF infection generally responds well to ART, even in the face of systemic virological failure due to drug resistance. We present simple models to explain the differing relationships of CSF to plasma HIV in these settings.

  1. A sampling system for collecting gas-tight time-series hydrothermal fluids (United States)

    Wu, S.; Yang, C.; Ding, K.


    It is known that the hydrothermal venting has temporal variations associated with tectonic and geochemical processes. To date, the methods for long-term monitoring of the seafloor hydrothermal systems are rare. A new sampling system has been designed to be deployed at seafloor for long term to collect gas-tight time-series samples from hydrothermal vents. Based on the modular design principle, the sampling system is currently composed of a control module and six sampling modules, which is convenient to be upgraded by adding more sampling modules if needed. The control module consists of a rechargeable battery pack and a circuit board with functions of sampling control, temperature measurement, data storage and communication. Each sampling module has an independent sampling valve, a valve actuator and a sampling cylinder. The sampling cylinder consists of a sample chamber and an accumulator chamber. Compressed nitrogen gas is used to maintain the sample at in-situ pressure. A prototype of the sampling system has been constructed and tested. First, the instrument was tested in a high-pressure vessel at a pressure of 40 MPa. Six sampling modules were successfully triggered and water samples were collected and kept at in-situ pressure after experiment. Besides, the instrument was field tested at the shallow hydrothermal field near off Kueishantao islet (24°51'N, 121°55'E), which is located offshore of northeastern Taiwan, from May 25 to May 28, 2011. The sampling system worked at an automatic mode. Each sampling module was triggered according to the preset time. Time-series hydrothermal fluids have been collected from a shallow hydrothermal vent with a depth of 16 m. The preliminary tests indicated the success of the design and construction of the prototype of the sampling system. Currently, the sampling system is being upgraded by integration of a DC-DC power conversion and serial-to-Ethernet conversion module, so that it can utilize the continuous power supply and

  2. An improved dissipative coupling scheme for a system of Molecular Dynamics particles interacting with a Lattice Boltzmann fluid (United States)

    Tretyakov, Nikita; Dünweg, Burkhard


    We consider the dissipative coupling between a stochastic Lattice Boltzmann (LB) fluid and a particle-based Molecular Dynamics (MD) system, as it was first introduced by Ahlrichs and Dünweg (1999). The fluid velocity at the position of a particle is determined by interpolation, such that a Stokes friction force gives rise to an exchange of momentum between the particle and the surrounding fluid nodes. For efficiency reasons, the LB time step is chosen as a multiple of the MD time step, such that the MD system is updated more frequently than the LB fluid. In this situation, there are different ways to implement the coupling: Either the fluid velocity at the surrounding nodes is only updated every LB time step, or it is updated every MD step. It is demonstrated that the latter choice, which enforces momentum conservation on a significantly shorter time scale, is clearly superior in terms of temperature stability and accuracy, and nevertheless only marginally slower in terms of execution speed. The second variant is therefore the recommended implementation.

  3. Feedback Linearization in a Six Degree-of-Freedom MAG-LEV Stage (United States)

    Ludwick, Stephen J.; Trumper, David L.; Holmes, Michael L.


    A six degree-of-freedom electromagnetically suspended motion control stage (the Angstrom Stage) has been designed and constructed for use in short-travel, high-resolution motion control applications. It achieves better than 0.5 nm resolution over a 100 micron range of travel. The stage consists of a single moving element (the platen) floating in an oil filled chamber. The oil is crucial to the stage's operation since it forms squeeze film dampers between the platen and the frame. Twelve electromagnetic actuators provide the forces necessary to suspend and servo the platen, and six capacitance probes measure its position relative to the frame. The system is controlled using a digital signal processing board residing in a '486 based PC. This digital controller implements a feedback linearization algorithm in real-time to account for nonlinearities in both the magnetic actuators and the fluid film dampers. The feedback linearization technique reduces a highly nonlinear plant with coupling between the degrees of freedom into one that is linear, decoupled, and setpoint independent. The key to this procedure is a detailed plant model. The operation of the feedback linearization procedure is transparent to the outer loop of the controller, and so a proportional controller is sufficient for normal operation. We envision applications of this stage in scanned probe microscopy and for integrated circuit measurement.

  4. On a Five-Dimensional Chaotic System Arising from Double-Diffusive Convection in a Fluid Layer

    Directory of Open Access Journals (Sweden)

    R. Idris


    Full Text Available A chaotic system arising from double-diffusive convection in a fluid layer is investigated in this paper based on the theory of dynamical systems. A five-dimensional model of chaotic system is obtained using the Galerkin truncated approximation. The results showed that the transition from steady convection to chaos via a Hopf bifurcation produced a limit cycle which may be associated with a homoclinic explosion at a slightly subcritical value of the Rayleigh number.

  5. Playful teaching between freedom and control

    DEFF Research Database (Denmark)

    Nørgård, Rikke Toft; Toft-Nielsen, Claus; Whitton, Nicola


    and play culture – to explore an alternative more ‘playful approach’ to teaching and learning. Here, we highlight the potentials of playful teaching through adopting a ‘lusory attitude’ oscillating between free-form play and rule-bound systems. This development of a more playful approach to HE is promising...... as it invites for a different type of teaching and learning environment, providing a safe educational space, in which mistake-making is not only encouraged, but engrained into the system. Taking up a ‘lusory attitude’ in the magic circle can create freedom, support playfulness and intrinsic motivation, and make...... HE emerge as an open educational process rather than as high-score assessment product....

  6. Gingival crevicular fluid in the diagnosis of periodontal and systemic diseases

    Directory of Open Access Journals (Sweden)

    Čakić Saša


    Full Text Available Gingival crevicular fluid (GCF can be found in the physiologic space (gingival sulcus, as well as in the pathological space (gingival pocket or periodontal pocket between the gums and teeth. In the first case it is a transudate, in the second an exudate. The constituents of GCF originate from serum, gingival tissues, and from both bacterial and host response cells present in the aforementioned spaces and the surrounding tissues. The collection and analysis of GCF are the noninvasive methods for the evaluation of host response in periodontal disease. These analyses mainly focus on inflammatory markers, such as prostaglandin E2, neutrophil elastase and β-glucuronidase, and on the marker of cellular necrosis - aspartat aminotransferase. Further, the analysis of inflammatory markers in the GCF may assist in defining how certain systemic diseases (e.g., diabetes mellitus can modify periodontal disease, and how peridontal disease can influence certain systemic disorders (atherosclerosis, preterm delivery, diabetes mellitus and some chronic respiratory diseases. Major factors which influence the results obtained from the analyses of GCF are not only the methods of these analyses, but the method of GCF collection as well. As saliva collection is less technique-sensitive than GCF collection, some constituents of saliva which originate from the GCF can be analyzed as more amenable to chairside utilization.

  7. Highly Sensitive and Miniaturized Fluorescence Detection System with an Autonomous Capillary Fluid Manipulation Chip

    Directory of Open Access Journals (Sweden)

    Ji Fang


    Full Text Available This paper presents a novel, highly sensitive and ultra-small fluorescent detection system, including an autonomous capillary fluid manipulation chip. The optical detector integrates a LED light source, all necessary optical components, and a photodiode with preamplifier into one package of about 2 cm × 2 cm × 2 cm. Also, the low-cost and simple pumpless microfluidic device works well in sample preparation and manipulation. This chip consists of capillary stop valves and trigger valves which are fabricated by lithography and then bonded with a polydimethylsiloxane-ethylene oxide polymer polydimethylsiloxane (PEO-PDMS cover. The contact angle of the PEO-PDMS can be adjusted by changing the concentration of the PEO. Hence, the fluidic chip can achieve functionalities such as timing features and basic logical functions. The prototype has been tested by fluorescence dye 5-Carboxyfluorescein (5-FAM dissolved into the solvent DMSO (Dimethyl Sulfoxide. The results prove a remarkable sensitivity at a pico-scale molar, around 1.08 pM. The low-cost and miniaturized optical detection system, with a self-control capillary-driven microfluidic chip developed in this work, can be used as the crucial parts in portable biochemical detection applications and point of care testing.

  8. Systemic Associations with Residual Subretinal Fluid after Ranibizumab in Diabetic Macular Edema

    Directory of Open Access Journals (Sweden)

    Meng-Ju Tsai


    Full Text Available Purpose. To investigate the impact of systemic diseases on the occurrence of subretinal fluid (SRF in diabetic macular edema (DME and prognostic factors for residual SRF following three consecutive monthly intravitreal ranibizumab. Methods. Ninety-seven eyes from 68 patients with DME who completed 3 consecutive monthly injections of ranibizumab were enrolled. Systemic parameters mainly included chronic kidney disease (CKD, hypertension, HbA1c, and insulin dependence. Renal parameters for CKD were serum creatinine, estimated glomerular filtration rate (eGFR, and serum albumin. Ocular factors were baseline central macular thickness (CMT, severity of diabetic retinopathy (DR, and status of panretinal photocoagulation (PRP. Results. Chronic kidney disease had significant correlation with baseline SRF (R=0.397, p<0.001 after partial correlation with adjustment for age and DR severity. As for CKD, lower serum albumin, but not eGFR or serum creatinine, was associated with baseline presence of SRF (p=0.026, p=0.08 and p=0.53, resp., after adjustment for age and DR severity. Overall, lower eGFR and lower HbA1c values, contrary to popular belief, predicted the presence of residual SRF following intravitreal injections (p=0.016 and p<0.001, resp.. Conclusions. Tight sugar control and poorer baseline kidney function may slow the resorption of SRF after anti-VEGF injections in patients with DME in the short term.

  9. Modeling Physiological Systems in the Human Body as Networks of Quasi-1D Fluid Flows (United States)

    Staples, Anne


    Extensive research has been done on modeling human physiology. Most of this work has been aimed at developing detailed, three-dimensional models of specific components of physiological systems, such as a cell, a vein, a molecule, or a heart valve. While efforts such as these are invaluable to our understanding of human biology, if we were to construct a global model of human physiology with this level of detail, computing even a nanosecond in this computational being's life would certainly be prohibitively expensive. With this in mind, we derive the Pulsed Flow Equations, a set of coupled one-dimensional partial differential equations, specifically designed to capture two-dimensional viscous, transport, and other effects, and aimed at providing accurate and fast-to-compute global models for physiological systems represented as networks of quasi one-dimensional fluid flows. Our goal is to be able to perform faster-than-real time simulations of global processes in the human body on desktop computers.

  10. Coefficients of viscosity for a fluid in a magnetic field or in a rotating system

    NARCIS (Netherlands)

    Hooyman, G.J.; Mazur, P.; Groot, S.R. de


    The linear equations between the elements of the viscous pressure tensor and the rates of deformation are investigated for the case of an isotropic fluid in an external magnetic field or for the equivalent case of a rotating fluid. Since these equations can be incorporated within the thermodynamics

  11. Fluid–fluid coexistence in colloidal systems with short-ranged strongly directional attraction

    NARCIS (Netherlands)

    Kern, N.; Frenkel, D.


    We present a systematic numerical study of the phase behavior of square-well fluids with a "patchy" short-ranged attraction. In particular, we study the effect of the size and number of attractive patches on the fluid–fluid coexistence. The model that we use is a generalization of the hard sphere

  12. Numerical study of coupled fluid-structure interaction for combustion system

    NARCIS (Netherlands)

    Khatir, Z.; Pozarlik, Artur Krzysztof; Cooper, R.K.; Watterson, J.W.; Kok, Jacobus B.W.


    The computation of fluid–structure interaction (FSI) problems requires solving simultaneously the coupled fluid and structure equations. A partitioned approach using a volume spline solution procedure is applied for the coupling of fluid dynamics and structural dynamics codes. For comparative study,

  13. Critical evaluation and comparison of fluid distribution systems for industrial scale expanded bed adsorption chromatography columns

    DEFF Research Database (Denmark)

    Arpanaei, Ayyoob; Heebøll-Nielsen, Anders; Hubbuch, Jürgen


    The hydrodynamic properties of an expanded bed contactor with 30 cm or 150 cm internal diameter, which employs a rotating or oscillating fluid distributor, were compared to prototype columns of 60 cm or 150 cm diameter employing local stirring (fixed wall nozzles plus central bottom mounted stirrer......) for fluid distribution. Fluid introduction through a rotating fluid distributor was found to give superior hydrodynamic characteristics in the 30 cm and 150 cm diameter column compared to using the local stirrer in both the 60 cm and 150 cm diameter columns. The shortcomings of the local stirring...... distributor at large scale were apparent: dead zones were present which could not be removed by increasing rotation rates or flow rates, and such changes led to a deterioration in hydrodynamic properties. In contrast, during fluid introduction through a rotating distributor no dead zones were observed...

  14. Informatic system for a global tissue-fluid biorepository with a graph theory-oriented graphical user interface

    NARCIS (Netherlands)

    Butler, William E.; Atai, Nadia; Carter, Bob; Hochberg, Fred


    The Richard Floor Biorepository supports collaborative studies of extracellular vesicles (EVs) found in human fluids and tissue specimens. The current emphasis is on biomarkers for central nervous system neoplasms but its structure may serve as a template for collaborative EV translational studies

  15. Effect of initial fluid-system pressures on the behavior of a rupture-disc pressure-relief device

    International Nuclear Information System (INIS)

    Hsieh, B.J.; Shin, Y.W.; Kot, C.A.


    Rupture disc assemblies are used in piping network systems as a pressure-relief device to protect the system from being exposed to excess pressures. Among the various disc assemblies, the reverse-buckling type is chosen for application in the Clinch River Breeder Reactor. This rupture-disc assembly consists of a portion of a thin spherical shell with its convex side subjected to the fluid system. The reverse-buckling type rupture disc assemblies have been used successfully in environments where the fluid is gas, i.e. highly compressible, and their performances have been judged as adequate in the liquid environment. To analyze the piping system, an analysis method is needed taking into consideration of the fluid/disc interaction, the nonlinear dynamic buckling phenomenon of the disc, and the possible cavitation of the fluid. A computer code SWAAM-I had been written at the Components Technology Division, Argonne National Laboratory. Among its many functions, one is to compute the response of 1-dimensional pressure pulse propagation including the effects of many different types of boundary conditions and possible pipe plasticity

  16. Thermal Protection System Cavity Heating for Simplified and Actual Geometries Using Computational Fluid Dynamics Simulations with Unstructured Grids (United States)

    McCloud, Peter L.


    Thermal Protection System (TPS) Cavity Heating is predicted using Computational Fluid Dynamics (CFD) on unstructured grids for both simplified cavities and actual cavity geometries. Validation was performed using comparisons to wind tunnel experimental results and CFD predictions using structured grids. Full-scale predictions were made for simplified and actual geometry configurations on the Space Shuttle Orbiter in a mission support timeframe.

  17. Characterization and experimental validation of a squeeze film damper with MR fluid in a rotor-bearing system (United States)

    Dominguez-Nuñez, L. A.; Silva-Navarro, G.


    The general study and applications of Magneto-Rhelogical (MR) dampers have been spread in the lasts years but only some studies have been focusing on the vibration control problems on rotor-bearings systems. Squeeze-Film Dampers (SFD) are now commonly used to passively control the vibration response on rotor-bearing systems because they can provide flexibility, damping and extend the so-called stability thresholds in rotating machinery. More recently, SFD are combined with MR or Electro-Rheological (ER) fluids to introduce a semiactive control mechanism to modify the rotordynamic coefficients and deal with the robust performance of the overall system response for higher operating speeds. There are, however, some theoretical and technological problems that complicate their extensive use, like the relationship between the centering spring flexibility and the rheological behavior of the smart fluid to produce the SFD forces. In this work it is considered a SFD with MR fluid and a set of circular section beams in a squirrel cage arrangement in combination with latex seals as centering springs. The mathematical model analysis includes the controllable viscoelastic properties associated to the MR fluid. The characterization of the SFD is made by the determination of some coefficients associated with a modified Choi-Lee-Park polynomial model. During the analysis is considered a rotor-bearing system modeled using finite element methods. The SFD with MR fluid is connected to an experimental platform to validate and experimentally evaluate the overall system. Finally, to improve the open-loop system performance, a methodology for the use of different control schemes is proposed.

  18. On creative machines and the physical origins of freedom. (United States)

    Briegel, Hans J


    We discuss the possibility of free behavior in embodied systems that are, with no exception and at all scales of their body, subject to physical law. We relate the discussion to a model of an artificial agent that exhibits a primitive notion of creativity and freedom in dealing with its environment, which is part of a recently introduced scheme of information processing called projective simulation. This provides an explicit proposal on how we can reconcile our understanding of universal physical law with the idea that higher biological entities can acquire a notion of freedom that allows them to increasingly detach themselves from a strict dependence on the surrounding world.

  19. A Multi-Fluid Compressible System as the Limit of Weak Solutions of the Isentropic Compressible Navier-Stokes Equations (United States)

    Bresch, D.; Huang, X.


    This paper mainly concerns the mathematical justification of a viscous compressible multi-fluid model linked to the Baer-Nunziato model used by engineers, see for instance I shii (Thermo-fluid dynamic theory of two-phase flow, Eyrolles, Paris, 1975), under a "stratification" assumption. More precisely, we show that some approximate finite-energy weak solutions of the isentropic compressible Navier-Stokes equations converge, on a short time interval, to the strong solution of this viscous compressible multi-fluid model, provided the initial density sequence is uniformly bounded with corresponding Young measures which are linear convex combinations of m Dirac measures. To the authors' knowledge, this provides, in the multidimensional in space case, a first positive answer to an open question, see H illairet (J Math Fluid Mech 9:343-376, 2007), with a stratification assumption. The proof is based on the weak solutions constructed by D esjardins (Commun Partial Differ Equ 22(5-6):977-1008, 1997) and on the existence and uniqueness of a local strong solution for the multi-fluid model established by H illairet assuming initial density to be far from vacuum. In a first step, adapting the ideas from H off and S antos (Arch Ration Mech Anal 188:509-543, 2008), we prove that the sequence of weak solutions built by D esjardins has extra regularity linked to the divergence of the velocity without any relation assumption between λ and μ. Coupled with the uniform bound of the density property, this allows us to use appropriate defect measures and their nice properties introduced and proved by H illairet (Aspects interactifs de la m'ecanique des fluides, PhD Thesis, ENS Lyon, 2005) in order to prove that the Young measure associated to the weak limit is the convex combination of m Dirac measures. Finally, under a non-degeneracy assumption of this combination ("stratification" assumption), this provides a multi-fluid system. Using a weak-strong uniqueness argument, we prove that

  20. Coupling Fluid Dynamics and Multiphase Disequilibria: Applications to Eutectic and Peritectic Systems (United States)

    Tweed, L. E. L.; Spiegelman, M. W.; Kelemen, P. B.


    Computational thermodynamics has yielded great insights into petrological processes. However, on its own it cannot capture the inherently dynamic nature of many of these processes which depend on the interaction between time-dependent processes including advection, diffusion and chemical reaction. To understand this interplay, and to move away from a purely equilibrium view, requires the integration of computational thermodynamics and fluid mechanics. A key aspect of doing this is the treatment of chemical reactions as time-dependent, irreversible processes. Such a development is integral to understanding a host of petrological questions from the open system evolution of magma chambers to the dynamics of melt migration beneath mid-ocean ridges and flux melting of the mantle wedge in subduction zones. A simple thermodynamically consistent reactive model is developed that can be integrated with conservation equations for mass, momentum and energy. The model rests on the thermodynamic characterization of an independent set of reactions and has the advantage of being completely general and easily extensible to systems comprising multiple solid and liquid phases. The underlying theory is described in detail in another contribution in this session. Here we apply the framework to experimentally constrained simple systems of petrological interest including the fo-qz binary and the fo-qz-k2o ternary. These systems contain a variety of phase topologies including eutectic and peritectic reactions. As the model allows for the seamless exhaustion and stabilization of phases, we can explore the effect that these discontinuous changes have on the compositional and dynamic evolution of the system. To do this we track how the systems respond to sudden changes in intensive variables that perturb them from equilibrium. Such changes are rife in crustal magmatic systems. Simulations for decompression melting are also run to explore the interplay between reactive and advective fluxes

  1. Fluid-driven origami-inspired artificial muscles (United States)

    Li, Shuguang; Vogt, Daniel M.; Rus, Daniela; Wood, Robert J.


    Artificial muscles hold promise for safe and powerful actuation for myriad common machines and robots. However, the design, fabrication, and implementation of artificial muscles are often limited by their material costs, operating principle, scalability, and single-degree-of-freedom contractile actuation motions. Here we propose an architecture for fluid-driven origami-inspired artificial muscles. This concept requires only a compressible skeleton, a flexible skin, and a fluid medium. A mechanical model is developed to explain the interaction of the three components. A fabrication method is introduced to rapidly manufacture low-cost artificial muscles using various materials and at multiple scales. The artificial muscles can be programed to achieve multiaxial motions including contraction, bending, and torsion. These motions can be aggregated into systems with multiple degrees of freedom, which are able to produce controllable motions at different rates. Our artificial muscles can be driven by fluids at negative pressures (relative to ambient). This feature makes actuation safer than most other fluidic artificial muscles that operate with positive pressures. Experiments reveal that these muscles can contract over 90% of their initial lengths, generate stresses of ˜600 kPa, and produce peak power densities over 2 kW/kg—all equal to, or in excess of, natural muscle. This architecture for artificial muscles opens the door to rapid design and low-cost fabrication of actuation systems for numerous applications at multiple scales, ranging from miniature medical devices to wearable robotic exoskeletons to large deployable structures for space exploration.

  2. Computational fluid dynamic (CFD) analysis on ALUDRA SR-10 UAV with parachute recovery system (United States)

    Saim, R.; Mohd, S.; Shamsudin, S. S.; Zulkifli, M. F.; Omar, Z.; Subari@Rahmat, Z.; Masrom, M. F. Mohd; Zaki, Y.


    In an operation, belly landing is mostly applied as recovery method especially on research Unmanned Aerial Vehicle (UAV) such as Aludra SR-10. This type of landing method may encounter tough landing on hard soil and gravel which create high impact load on the aircraft. The impact may cause structural or system damage which costly to be repaired. Nowadays, Parachute Recovery System (PRS) recently used in numerous different tasks such as landing purpose to replace belly landing technique. Parachute use in this system to slow down flying or falling UAV to a safe landing by opening the canopy to increase aerodynamic drag. This paper was described the Computational Fluid Dynamic (CFD) analysis on ALUDRA SR-10 model with two different conditions i.e. the UAV equipped with and without parachute in order to identify the changes of aerodynamic characteristics. This simulation studies using solid models of aircraft and hemisphere parachute and was carried out by using ANSYS 16.0 Fluent under steady and turbulent flow and was modelled using the k-epsilon (k-ε) turbulence model. This simulation was limited to determine the drag force and drag coefficient. The obtained result showed that implementation of parachute increase 0.25 drag coefficient of the aircraft that is from 0.93 to 1.18. Subsequent to the reduction of descent rate caused by the parachute, the drag force of the aircraft increase by 0.76N. These increasing of drag force of the aircraft will produce lower terminal velocity which is expected to reduce the impact force on the aircraft during landing.

  3. Computer simulation of thermal and fluid systems for MIUS integration and subsystems test /MIST/ laboratory. [Modular Integrated Utility System (United States)

    Rochelle, W. C.; Liu, D. K.; Nunnery, W. J., Jr.; Brandli, A. E.


    This paper describes the application of the SINDA (systems improved numerical differencing analyzer) computer program to simulate the operation of the NASA/JSC MIUS integration and subsystems test (MIST) laboratory. The MIST laboratory is designed to test the integration capability of the following subsystems of a modular integrated utility system (MIUS): (1) electric power generation, (2) space heating and cooling, (3) solid waste disposal, (4) potable water supply, and (5) waste water treatment. The SINDA/MIST computer model is designed to simulate the response of these subsystems to externally impressed loads. The computer model determines the amount of recovered waste heat from the prime mover exhaust, water jacket and oil/aftercooler and from the incinerator. This recovered waste heat is used in the model to heat potable water, for space heating, absorption air conditioning, waste water sterilization, and to provide for thermal storage. The details of the thermal and fluid simulation of MIST including the system configuration, modes of operation modeled, SINDA model characteristics and the results of several analyses are described.

  4. BBG 2009 Freedom of Information Act Repot (United States)

    Broadcasting Board of Governors — The Broadcasting Board of Governors' annual Freedom of Information Act (FOIA) report includes detailed statistics on the number and disposition of FOIA requests,...

  5. BBG 2008 Freedom of Information Act Report (United States)

    Broadcasting Board of Governors — The Broadcasting Board of Governors' annual Freedom of Information Act (FOIA) report includes detailed statistics on the number and disposition of FOIA requests,...

  6. A Legitimate Freedom Approach to Sustainability

    DEFF Research Database (Denmark)

    Crabtree, Andrew


    an integrate sustainability into the Human Development Index would thus give the wrong policy message. Drawing on the works of Amartya Sen and Thomas Scanlon, this article argues that sustainable development can be seen as a process of increasing legitimate freedoms, the freedoms that others cannot reasonably...... reject. Thus, Sen's vision of development as freedom is amended to suggest limits to freedoms. Forms of development which are not sustainable can be reasonably rejected due, at least, to the harm and blighting entailed. Based on this, it is argued that at country level of comparison the Human Development...

  7. Economic Freedom and Life Satisfaction : A Cross Country Analysis

    NARCIS (Netherlands)

    Graafland, J.J.; Compen, B.


    Abstract: This paper estimates the relationship between various sub-indicators of economic freedom and life satisfaction for 122 countries. The estimation results show that life satisfaction is positively related to the quality of the legal system and protection of property rights. For poor

  8. Freedom of information and records management in Ghana | Adams ...

    African Journals Online (AJOL)

    Some basic elements of FOI are provided, a summary of the Ghanaian draft bill given and the basic information infrastructure in the country examined. The paper argues that an effective records management system is required to ensure a successful implementation of a freedom of information law and cites from the United ...

  9. Single particle degrees of freedom in the interacting boson model

    NARCIS (Netherlands)

    Scholten, O.


    An overview is given of different aspects of the Interacting Boson Fermion Model, the extension of the interacting Boson Model to odd mass nuclei. The microscopic model for the coupling of single-particle degrees of freedom to the system of bosons is outlined and the interaction between the bosons

  10. Study on effects of turbulence promoter on fluid mixing in T-junction piping system

    International Nuclear Information System (INIS)

    Nagao, Akihiro; Hibara, Hideki; Ochi, Junji; Muramatsu, Toshiharu


    Flows in T-junction piping system with turbulence promoter have been investigated experimentally using flow visualization techniques (the dye injection method) and velocity measurement by LDV. Effects of turbulent promoter on characteristics of fluid mixing and thermal-striping phenomena are examined. From the experiment, following results are obtained. (1) Arch vortex is formed further than the case without promoter in the upstream station and is rapidly transported to the downstream direction. (2) Secondary flow induced in the cross section become stronger and the diffusion of axial momentum is promoted, as the height of turbulence promoter is higher. (3) Main flow deflects towards to the opposite side of branch pipe at the T-junction, as the height of turbulence promoter is higher, and as velocity ratio becomes smaller, and the flow continues to deflect to a considerably downstream station. (4) Velocity fluctuation is observed in the position where the vortex is formed, and it becomes a maximum at z/Dm=2. In the further downstream, velocity fluctuation decreases with the vortex breakdown, and it considerably remains to the downstream. (author)

  11. Application of computational fluid dynamics (CFD) simulation in a vertical axis wind turbine (VAWT) system (United States)

    Kao, Jui-Hsiang; Tseng, Po-Yuan


    The objective of this paper is to describe the application of CFD (Computational fluid dynamics) technology in the matching of turbine blades and generator to increase the efficiency of a vertical axis wind turbine (VAWT). A VAWT is treated as the study case here. The SST (Shear-Stress Transport) k-ω turbulence model with SIMPLE algorithm method in transient state is applied to solve the T (torque)-N (r/min) curves of the turbine blades at different wind speed. The T-N curves of the generator at different CV (constant voltage) model are measured. Thus, the T-N curves of the turbine blades at different wind speed can be matched by the T-N curves of the generator at different CV model to find the optimal CV model. As the optimal CV mode is selected, the characteristics of the operating points, such as tip speed ratio, revolutions per minute, blade torque, and efficiency, can be identified. The results show that, if the two systems are matched well, the final output power at a high wind speed of 9-10 m/s will be increased by 15%.

  12. Detection of free immunoglobulin light chains in cerebrospinal fluids of patients with central nervous system lymphomas. (United States)

    Schroers, Roland; Baraniskin, Alexander; Heute, Christoph; Kuhnhenn, Jan; Alekseyev, Andriy; Schmiegel, Wolff; Schlegel, Uwe; Pels, Hendrik-Johannes


    Diagnosis of central nervous system (CNS) lymphoma depends on histopathology of brain biopsies, because no reliable disease marker in the cerebrospinal fluid (CSF) has been identified yet. B-cell lymphomas such as CNS lymphomas are clonally restricted and express either kappa or lambda immunoglobulin light chains. The aim of this study was to find out a potential diagnostic value of free immunoglobulin light chains released into the CSF of CNS lymphoma patients. Kappa (kappa) and lambda (lambda) free immunoglobulin light chains (FLC) were measured in CSF and serum samples collected from 21 patients with primary and secondary CNS lymphomas and 14 control patients with different neurologic disorders. FLC concentrations and ratios were compared between patient groups and were further analyzed in correlation with clinical, cytopathological, and radiological findings. FLC concentrations for all patients were lower in CSF when compared to serum. In patients with CNS lymphoma, the FLC ratios in CSF were higher (range 392-0.3) compared to control patients (range 3.0-0.3). Irrespective of cytopathological proven lymphomatous meningitis, in 11/21 lymphoma CSF samples the FLC ratios were markedly above 3.0 indicating a clonally restricted B-cell population. Increased FLC ratios in CSF were found in those patients showing subependymal lymphoma contact as detected in magnetic resonance imaging. In summary, this is the first report demonstrating that a significant proportion of patients with CNS lymphomas display a markedly increased FLC ratio in the CSF.

  13. Light scattering studies of lower dimensional colloidal particle and critical fluid systems

    International Nuclear Information System (INIS)

    O'Sullivan, W.J.; Mockler, R.C.


    The authors have studied the response to compression of colloidal particle crystals in monolayers on the surface of water. The crystals deform elastically as the crystals are compressed in a Langmuir trough from a lattice spacing of ten microns to spacings less than two microns. A phase transition to a close packed triangular lattice phase occurs at very high densities, when the attractive van der Waals/steric interations between particles dominate. The authors have found that the aggregates formed, when a colloidal particle monolayer coagulates following switching off of the repulsive electric dipole-dipole interactions, show scale invariance with a fractal dimension consistent with the prediction of a theory of diffusion limited aggregation in two dimensions. The authors have made progress toward the development of a computer processed array detector-spectrometer to be used in studies of melting and crystallization of two dimensional colloidal particle films. Stable black bilipid membranes have been produced, both spherical and planar, with and without embedded microparticles. We have modified our heterodyne autocorrelation spectrometer, used for studies of the dynamic response of critical fluid films, to enable us to measure the intensity autocorrelation of light scattered at forward angles. Rayleigh linewidth data has been gathered from a 1.9 micron film of a 2,6-lutidine+water critical mixture, taken at a scattering angle of ten degrees. The preliminary results indicate that the film dynamical response remains that of an equivalent three dimensional system, in apparent disgreement with recent theoretical predictions of Calvo and Ferrell

  14. Cellular Biotechnology Operations Support Systems-Fluid Dynamics Investigation (CBOSS-FDI) (United States)


    Aboard the International Space Station (ISS), the Tissue Culture Module (TCM) is the stationary bioreactor vessel in which cell cultures grow. However, for the Cellular Biotechnology Operations Support Systems-Fluid Dynamics Investigation (CBOSS-FDI), color polystyrene beads are used to measure the effectiveness of various mixing procedures. Uniform mixing is a crucial component of CBOSS experiments involving the immune response of human lymphoid cell suspensions. In this picture, the beads are trapped in the injection port shortly after injection. Swirls of beads indicate, event to the naked eye, the contents of the TCM are not fully mixed. The beads are similar in size and density to human lymphoid cells. The goal is to develop procedures that are both convenient for the flight crew and are optimal in providing uniform and reproducible mixing of all components, including cells. The average bead density in a well mixed TCM will be uniform, with no bubbles, and it will be measured using the absorption of light

  15. Model Predictive Control of a Wave Energy Converter with Discrete Fluid Power Power Take-Off System

    Directory of Open Access Journals (Sweden)

    Anders Hedegaard Hansen


    Full Text Available Wave power extraction algorithms for wave energy converters are normally designed without taking system losses into account leading to suboptimal power extraction. In the current work, a model predictive power extraction algorithm is designed for a discretized power take of system. It is shown how the quantized nature of a discrete fluid power system may be included in a new model predictive control algorithm leading to a significant increase in the harvested power. A detailed investigation of the influence of the prediction horizon and the time step is reported. Furthermore, it is shown how the inclusion of a loss model may increase the energy output. Based on the presented results it is concluded that power extraction algorithms based on model predictive control principles are both feasible and favorable for use in a discrete fluid power power take-off system for point absorber wave energy converters.

  16. Six degree of freedom sensor (United States)

    Vann, C.S.


    This small, non-contact optical sensor increases the capability and flexibility of computer controlled machines by detecting its relative position to a workpiece in all six degrees of freedom (DOF). At a fraction of the cost, it is over 200 times faster and up to 25 times more accurate than competing 3-DOF sensors. Applications range from flexible manufacturing to a 6-DOF mouse for computers. Until now, highly agile and accurate machines have been limited by their inability to adjust to changes in their tasks. By enabling them to sense all six degrees of position, these machines can now adapt to new and complicated tasks without human intervention or delay--simplifying production, reducing costs, and enhancing the value and capability of flexible manufacturing. 3 figs.

  17. Architectural freedom and industrialised architecture

    DEFF Research Database (Denmark)

    Vestergaard, Inge


    Architectural freedom and industrialized architecture. Inge Vestergaard, Associate Professor, Cand. Arch. Aarhus School of Architecture, Denmark Noerreport 20, 8000 Aarhus C Telephone +45 89 36 0000 E-mai l Based on the repetitive architecture from the "building boom" 1960...... customization, telling exactly the revitalized storey about the change to a contemporary sustainable and better performed expression in direct relation to the given context. Through the last couple of years we have in Denmark been focusing a more sustainable and low energy building technique, which also include...... to the building physic problems a new industrialized period has started based on light weight elements basically made of wooden structures, faced with different suitable materials meant for individual expression for the specific housing area. It is the purpose of this article to widen up the different design...

  18. Euler's fluid equations: Optimal control vs optimization

    International Nuclear Information System (INIS)

    Holm, Darryl D.


    An optimization method used in image-processing (metamorphosis) is found to imply Euler's equations for incompressible flow of an inviscid fluid, without requiring that the Lagrangian particle labels exactly follow the flow lines of the Eulerian velocity vector field. Thus, an optimal control problem and an optimization problem for incompressible ideal fluid flow both yield the same Euler fluid equations, although their Lagrangian parcel dynamics are different. This is a result of the gauge freedom in the definition of the fluid pressure for an incompressible flow, in combination with the symmetry of fluid dynamics under relabeling of their Lagrangian coordinates. Similar ideas are also illustrated for SO(N) rigid body motion.

  19. Educational Vouchers: Freedom to Choose?

    Directory of Open Access Journals (Sweden)

    Jordan Reel


    Full Text Available Milton Friedman is famous for his book title: “Free to Choose.” He also favors educational vouchers, which denies the freedom to choose to people who do not wish to subsidize the education of other people’s children. Thus, he is guilty of a logical contradiction. Why is it important to assess whether Friedman’s views on educational vouchers are logically consistent with his widespread reputation as an advocate of free enterprise, and, thus, freedom to chose? It is important to assess all figures in political economy, and indeed all of scholarship, for logical consistency. It is particularly important to do so in the present case, given the prestige in certain quarters accorded to this Nobel prize-winning economist. We argue in this paper that Friedman’s reputation for logical consistency, and adherence to the philosophy of laissez faire capitalism, are both overblown. Our solution to this challenge is to completely privatize education. Friedman does not advocate that vouchers be utilized for food, clothing or shelter; we see no relevant difference in the case of education. What is the justification of the undertaken topic? This topic is important because education of the next generation is crucial for the upkeep and improvement of society. What is the aim of the present study? It is to demonstrate that the solution offered by M. Friedman and R. Friedman (1990 is highly problematic. What is the methodology used in the study? We quote from this author, and criticize his analysis. What are our main results and conclusions/recommendations? We conclude that the last best hope for the educational industry is laissez faire capitalism, not the mixed economy recommended by Friedman.

  20. Informatic system for a global tissue-fluid biorepository with a graph theory-oriented graphical user interface


    Butler, William E.; Atai, Nadia; Carter, Bob; Hochberg, Fred


    The Richard Floor Biorepository supports collaborative studies of extracellular vesicles (EVs) found in human fluids and tissue specimens. The current emphasis is on biomarkers for central nervous system neoplasms but its structure may serve as a template for collaborative EV translational studies in other fields. The informatic system provides specimen inventory tracking with bar codes assigned to specimens and containers and projects, is hosted on globalized cloud computing resources, and e...