WorldWideScience

Sample records for applying temperature control

  1. Applied Control Systems Design

    CERN Document Server

    Mahmoud, Magdi S

    2012-01-01

    Applied Control System Design examines several methods for building up systems models based on real experimental data from typical industrial processes and incorporating system identification techniques. The text takes a comparative approach to the models derived in this way judging their suitability for use in different systems and under different operational circumstances. A broad spectrum of control methods including various forms of filtering, feedback and feedforward control is applied to the models and the guidelines derived from the closed-loop responses are then composed into a concrete self-tested recipe to serve as a check-list for industrial engineers or control designers. System identification and control design are given equal weight in model derivation and testing to reflect their equality of importance in the proper design and optimization of high-performance control systems. Readers’ assimilation of the material discussed is assisted by the provision of problems and examples. Most of these e...

  2. Active chemistry control for coolant helium applying high-temperature gas-cooled reactors - HTR2008-58096

    International Nuclear Information System (INIS)

    Lifetime extension of high-temperature equipment such as the intermediate heat exchanger of high-temperature gas-cooled reactors (HTGRs) is important from the economical point of view. Since the replacing cost will cause the increasing of the running cost, it is important to reduce replacing times of the high-cost primary equipment during assumed reactor lifetime. In the past, helium chemistry has been controlled by the passive chemistry control technology in which chemical impurity in the coolant helium is removed as low concentration as possible, as does Japan's HTTR. Although the lifetime of high- temperature equipment almost depends upon the chemistry conditions in the coolant helium, it is necessary to establish an active chemistry control technology to maintain adequate chemical conditions. In this study, carbon deposition which could occur at the surface of the heat transfer tubes of the intermediate heat exchanger and decarburization of the high-temperature material of Hastelloy XR used at the heat transfer tubes were evaluated by referring the actual chemistry data obtained by the HTTR. The chemical equilibrium study contributed to clarify the algorism of the chemistry behaviours to be controlled. The created algorism is planned to be added to the instrumentation system of the helium purification systems. In addition, the chemical composition to be maintained during the reactor operation was proposed by evaluating not only core graphite oxidation but also carbon deposition and decarburization. It was identified when the chemical composition could not keep adequately, injection of 10 ppm carbon monoxide could effectively control the chemical composition to the designated stable area where the high-temperature materials could keep their structural integrity beyond the assumed duration. The proposed active chemistry control technology is expected to contribute economically to the purification systems of the future very high-temperature reactors. (authors)

  3. Control of supply temperature

    Energy Technology Data Exchange (ETDEWEB)

    Madsen, H.; Nielsen, T.S.; Soegaard, H.T.

    1996-09-01

    For many district heating systems, e.g. the system in Hoeje Taastrup, it is desirable to minimize the supply temperature from the heat production unit(s). Lower supply temperature implies lower costs in connection with the production and distribution of heat. Factors having impact on the heat demand are for instance solar radiation, wind speed, wind direction and a climate independent part, which is a function of the time of the day/week/year. By applying an optimization strategy, which minimizes the supply temperature, it is assumed that optimal economical operation can be obtained by minimizing the supply temperature and thereby the heat losses in the system. The models and methods described in this report take such aspects into account, and can therefore be used as elements in a more efficient minimization of the supply temperature. The theoretical part of this report describes models and methods for optimal on-line control of the supply temperature in district heating systems. Some of the models and methods have been implemented - or are going to be implemented - in the computer program PRESS which is a tool for optimal control of supply temperature and forecasting of heat demand in district heating systems. The principles for using transfer function models are briefly described. The ordinary generalized predictive control (OGPC) method is reviewed, and several extensions of this method are suggested. New controller, which is called the extended generalized predictive controller (XGPC), is described. (EG) 57 refs.

  4. Temperature controlled retinal photocoagulation

    Science.gov (United States)

    Schlott, Kerstin; Koinzer, Stefan; Baade, Alexander; Birngruber, Reginald; Roider, Johann; Brinkmann, Ralf

    2013-06-01

    Retinal photocoagulation lacks objective dosage in clinical use, thus the commonly applied lesions are too deep and strong, associated with pain reception and the risk of visual field defects and induction of choroidal neovascularisations. Optoacoustics allows real-time non-invasive temperature measurement in the fundus during photocoagulation by applying short probe laser pulses additionally to the treatment radiation, which excite the emission of ultrasonic waves. Due to the temperature dependence of the Grüneisen parameter, the amplitudes of the ultrasonic waves can be used to derive the temperature of the absorbing tissue. By measuring the temperatures in real-time and automatically controlling the irradiation by feedback to the treatment laser, the strength of the lesions can be defined. Different characteristic functions for the time and temperature dependent lesion sizes were used as rating curves for the treatment laser, stopping the irradiation automatically after a desired lesion size is achieved. The automatically produced lesion sizes are widely independent of the adjusted treatment laser power and individual absorption. This study was performed on anaesthetized rabbits and is a step towards a clinical trial with automatically controlled photocoagulation.

  5. Neuralfussy multivariable control applied to the control of velocity, power, and exhaust gas temperature of a turbo gas unit; Control neurodifuso multivariable aplicado al control de velocidad, potencia y temperatura de gases de escape de una unidad turbogas

    Energy Technology Data Exchange (ETDEWEB)

    Segura Ozuna, Victor Octavio

    2004-11-15

    The electric power demand in Mexico has forced to the electric sector to be in a constant search of methods and systems that, among other objectives, improve the operation of the generating power stations of electric power continually. As part of their mission, the Electrical Research Institute (IIE) has promoted and leaning the applied research and the technological development to improve the indexes of security, readiness, dependability, efficiency and durability of central generating by means of the development and the installation of big digital systems of information and control. At the present time, inside the scheme of electric power generation, the gas turbine (UTG) represent 7% of the generation of the national electric sector [1]. These units have become the dominant way of the new electric generation in the U.S, either in simple cycle or combined. The above-mentioned, is attributable at less installation cost for generated kilowatt, to the shortest construction programs, at first floor levels of emission of pollutants and competitive operation costs. The control system of the gas turbine is based on conventional control algorithms of the type PI [2]. This control scheme is dedicated for regulation tasks and rejection to interferences, and it doesn't stop pursuit of reference points. The controllers act all on a control valve, that which represents a strong interaction among the same ones, for example an adjustment in the parameters of the algorithm of the digital PI of temperature, it can improve their acting but it can also affect the acting of the speed control or that of power. The gas turbine presents a non lineal behavior and variant in the time, mainly in the starting stage where several important disturbances are presented. At the moment, the controllers used in the scheme of control of the turbines are lineal, which are syntonized for a specific operation point and they are conserved this way by indefinite time. In this thesis the

  6. Temperature measurement and control

    CERN Document Server

    Leigh, JR

    1988-01-01

    This book treats the theory and practice of temperature measurement and control and important related topics such as energy management and air pollution. There are no specific prerequisites for the book although a knowledge of elementary control theory could be useful. The first half of the book is an application oriented survey of temperature measurement techniques and devices. The second half is concerned mainly with temperature control in both simple and complex situations.

  7. Multi-variable neural-fuzzy control applied to the control of speed, power and temperature of turbo-gas units; Control neurodifuso multivariable aplicado al control de velocidad, potencia y temperatura de unidades turbogas

    Energy Technology Data Exchange (ETDEWEB)

    Segura O, Victor O; De Lara J, Salvador C [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico); Alvarado M, Victor M [Centro Nacional de Investigacion y Desarrollo Tecnologico (Cenidet), Cuernavaca, Morelos (Mexico)

    2005-07-01

    Gas turbines (GT) are high risk systems that operate at high velocities, temperatures and pressures. These conditions establish very strict requirements for the control system, reason why it is required a high automation level to obtain a safe and profitable operation. The control system of the turbo-gas units (TGU) is based on conventional control algorithms of type PI. This control scheme is destined for regulation and rejection of disturbance tasks, and not to follow reference points. All the controllers act on a single valve control, which represents a strong interaction between them. An alternative to treat this interaction and to improve the performance of the turbo-gas unit is the use of intelligent control techniques, adopting a pre-feedback scheme. The feedback control and the pre-feedback one are combined so that the first one assures the regulation around the operation points (for example, the synchronism velocity) and the second, provides the pursuit of the demanded trajectories established by the system. [Spanish] Las turbinas de gas (TG) son sistemas de alto riesgo que operan a altas velocidades, temperaturas y presiones. Estas condiciones establecen requerimientos muy estrictos para el sistema de control, por lo que se requiere en alto nivel de automatizacion para lograr una operacion segura y rentable. El sistema de control de las unidades turbogas (UTG) esta basado en algoritmos de control convencionales del tipo PI. Este esquema de control es destinado para tareas de regulacion y rechazo a perturbaciones, y no para seguimiento de puntos de referencia. Todos los controladores actuan sobre una sola valvula de control, lo que representa una fuerte interaccion entre los mismos. Una alternativa para tratar esta interaccion y mejorar el desempeno de la unidad turbogas es el empleo de tecnicas de control inteligente, adoptando un esquema retro-prealimentado. El control retroalimentado y el prealimentado se combinan para que el primero asegure la

  8. Temperature control during annealing

    International Nuclear Information System (INIS)

    Temperature control at a weld between a tube and tube plate having heat input from an inductive heating probe to effect annealing of the weld is performed with the aid of a signal generating receptor coil coupled with the probe. The signal from the coil experiences a characteristic change when the temperature of the weld reaches the required annealing temperature and this signal is used to control the heat input to the weld. The receptor coil can be inside the tube, outside the tube, embracing a number of similar tubes, or may be inside an adjacent tube. At the required anneal temperature, the materials of the tube and weld reach their Curie point which brings about a permeability change. (author)

  9. Apply for Cancer Control Grants

    Science.gov (United States)

    The Division of Cancer Control and Population Sciences funds a large portfolio of grants and contracts. The portfolio currently includes approximately 800 grants valued at nearly $450 million. Here we provide a listing of funding opportunities that are currently accepting applications. Please visit this page regularly as new funding opportunities are added upon approval by NCI.

  10. Temperature controlling cloth

    International Nuclear Information System (INIS)

    In a radiation protective cloth of the present invention, liquid channels made of a porous material which does not permeate liquid but permeate steams are formed, and a moisture absorbing cooling medium solution is flown to the channels to control temperature of a human body. Accordingly, the human body is cooled by the moisture absorbing cooling medium solution itself, and at the same time, sweat from the human body can be absorbed. If the liquid channels are composed of porous resin tubes or porous resin panels, those can be formed to clothes easily, and improve athletic performance since they are flexible. Further, use of an aqueous solution of lithium chloride, for example, as the moisture absorbing cooling medium solution, can provide merits of high moisture absorbing property, capability of dewatering by heating, and repeated use. (T.M.)

  11. Applied behavior analysis and statistical process control?

    OpenAIRE

    Hopkins, B. L.

    1995-01-01

    This paper examines Pfadt and Wheeler's (1995) suggestions that the methods of statistical process control (SPC) be incorporated into applied behavior analysis. The research strategies of SPC are examined and compared to those of applied behavior analysis. I argue that the statistical methods that are a part of SPC would likely reduce applied behavior analysts' intimate contacts with the problems with which they deal and would, therefore, likely yield poor treatment and research decisions. Ex...

  12. Applied Behavior Analysis and Statistical Process Control?

    Science.gov (United States)

    Hopkins, B. L.

    1995-01-01

    Incorporating statistical process control (SPC) methods into applied behavior analysis is discussed. It is claimed that SPC methods would likely reduce applied behavior analysts' intimate contacts with problems and would likely yield poor treatment and research decisions. Cases and data presented by Pfadt and Wheeler (1995) are cited as examples.…

  13. Adaptive Control Applied to Financial Market Data

    Czech Academy of Sciences Publication Activity Database

    Šindelář, Jan; Kárný, Miroslav

    Strasbourg cedex: European Science Foundation, 2007, s. 1-6. [Advanced Mathematical Methods for Finance. Vídeň (AT), 17.09.2007-22.09.2007] R&D Projects: GA MŠk(CZ) 2C06001 Institutional research plan: CEZ:AV0Z10750506 Keywords : bayesian statistics * portfolio optimization * finance * adaptive control Subject RIV: BB - Applied Statistics, Operational Research http://library.utia.cas.cz/separaty/2007/si/sindelar-adaptive control applied to financial market data.pdf

  14. Temperature and Humidity Control in Livestock Stables

    DEFF Research Database (Denmark)

    Hansen, Michael; Andersen, Palle; Nielsen, Kirsten M.;

    2010-01-01

    The paper describes temperature and humidity control of a livestock stable. It is important to have a correct air flow pattern in the livestock stable in order to achieve proper temperature and humidity control as well as to avoid draught. In the investigated livestock stable the air flow is...... controlled using wall mounted ventilation flaps. In the paper an algorithm for air flow control is presented meeting the needs for temperature and humidity while taking the air flow pattern in consideration. To obtain simple and realisable controllers a model based control design method is applied. In the...... design dynamic models for temperature and humidity are very important elements and effort is put into deriving and testing the models. It turns out that non-linearities are dominating in both models making feedback linearization the natural design method. The air controller as well as the temperature and...

  15. Temperature controlled strain gaged extensometer

    Science.gov (United States)

    Ramos, G. L.; Seplow, S.

    1968-01-01

    Temperature controlled strain-gaged extensometer measures longitudinal and girth deflections of pressure vessels in excess of one percent strain during pressurization and depressurization with cryogenic fluids at cryogenic temperatures. The device is of beryllium-copper strips.

  16. Adaptive Control Applied to Financial Market Data

    Czech Academy of Sciences Publication Activity Database

    Šindelář, Jan; Kárný, Miroslav

    Vol. I. Praha : Matfyz press, 2007, s. 1-6. ISBN 978-80-7378-023-4. [Week of Doctoral Students 2007. Praha (CZ), 05.06.2007-08.06.2007] R&D Projects: GA MŠk(CZ) 2C06001 Institutional research plan: CEZ:AV0Z10750506 Keywords : baysian statistics * finance * financial engineering * stochastic control Subject RIV: BB - Applied Statistics, Operational Research http://library.utia.cas.cz/separaty/2007/si/sindelar-adaptive control applied to financial market data.pdf

  17. Robust control applied to minimize NOx emissions

    OpenAIRE

    Nelson Gruel, Dominique; Chamaillard, Yann; Charlet, Alain; Colin, Guillaume

    2014-01-01

    — Legislation concerning pollutant emissions of diesel passenger cars is becoming increasingly restrictive, especially for nitrogen oxide (NOx) and particulate matter (PM). This article proposes to apply a CRONE control design methodology on a diesel engine in order to adapt the air-path and fuel-path of the engine and minimize NOx emissions. As the multivariable CRONE control strategies need a nominal transfer function and some frequency response of the system (G(s)), several test-bench expe...

  18. Study of temperature control for thermoluminescence dating

    International Nuclear Information System (INIS)

    The requirements of the temperature control in thermoluminescence (TL) dating were described briefly. The basic principles of heating control and application design to achieve high accuracy were introduced. Heating curves of RGD-3B TL reader are measured as an applied example, and the results show that high accuracy and good repeatability can be acquired. (authors)

  19. Advances in applied low-temperature plasma technology

    International Nuclear Information System (INIS)

    The generation of low-temperature plasma and its principle are described, and recent advances of applied low-temperature plasma technology in the emerging field of macromolecular plasma chemistry are reviewed. These applications involve plasma polymerization, synthesis, grafting, nanoparticle/powder cover, plasma-enhanced deposition of biocompatible layers, and low temperature plasma sterilization. (authors)

  20. Applied intelligent control of induction motor drives

    CERN Document Server

    Chan, Tze Fun

    2011-01-01

    Induction motors are the most important workhorses in industry. They are mostly used as constant-speed drives when fed from a voltage source of fixed frequency. Advent of advanced power electronic converters and powerful digital signal processors, however, has made possible the development of high performance, adjustable speed AC motor drives.This book aims to explore new areas of induction motor control based on artificial intelligence (AI) techniques in order to make the controller less sensitive to parameter changes. Selected AI techniques are applied for different induction motor control s.

  1. Applying vision feedback to crane controller design

    Science.gov (United States)

    Lee, Lun-Hui; Huang, Pei-Hsiang; Pan, Shing-Tai; Wijaya Lie, Handra; Chiang, Tung-Chien; Chang, Cheng-Yuan

    2015-01-01

    Encoders are generally used to track the motion of industrial mechanisms. However, the information obtained by encoders may have errors due to encoder aging or mechanism-design problem. Therefore, information by visual feedback is a better way to track the movement of industrial mechanisms. However, image information costs lots of computing effort so it is not easy to be used in real-time control applications. This manuscript derives a simple but effective visual feedback method to follow the target and the image information is obtained only by a general handy camcorder. Besides, the proposed method can track multi-locations in a meantime. Fast image pattern recognition and localisation of the colour histogram by using a moving tracking block is applied to increase the calculation speed. Finally, the obtained locations information by the proposed visual feedback method is applied in an industrial crane control system to verify the effectiveness.

  2. Controller modification applied for active fault detection

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Stoustrup, Jakob; Poulsen, Niels Kjølstad

    2014-01-01

    This paper is focusing on active fault detection (AFD) for parametric faults in closed-loop systems. This auxiliary input applied for the fault detection will also disturb the external output and consequently reduce the performance of the controller. Therefore, only small auxiliary inputs are used...... modify the feedback controller with a minor effect on the external output in the fault free case. Further, in the faulty case, the signature of the auxiliary input can be optimized. This is obtained by using a band-pass filter for the YJBK parameter that is only effective in a small frequency range where...... the frequency for the auxiliary input is selected. This gives that it is possible to apply an auxiliary input with a reduced amplitude. An example is included to show the results....

  3. Chaos control applied to heart rhythm dynamics

    International Nuclear Information System (INIS)

    Highlights: → A natural cardiac pacemaker is modeled by a modified Van der Pol oscillator. → Responses related to normal and chaotic, pathological functioning of the heart are investigated. → Chaos control methods are applied to avoid pathological behaviors of heart dynamics. → Different approaches are treated: stabilization of unstable periodic orbits and chaos suppression. - Abstract: The dynamics of cardiovascular rhythms have been widely studied due to the key aspects of the heart in the physiology of living beings. Cardiac rhythms can be either periodic or chaotic, being respectively related to normal and pathological physiological functioning. In this regard, chaos control methods may be useful to promote the stabilization of unstable periodic orbits using small perturbations. In this article, the extended time-delayed feedback control method is applied to a natural cardiac pacemaker described by a mathematical model. The model consists of a modified Van der Pol equation that reproduces the behavior of this pacemaker. Results show the ability of the chaos control strategy to control the system response performing either the stabilization of unstable periodic orbits or the suppression of chaotic response, avoiding behaviors associated with critical cardiac pathologies.

  4. Chaos control applied to heart rhythm dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Borem Ferreira, Bianca, E-mail: biaborem@gmail.com [Universidade Federal do Rio de Janeiro, COPPE, Department of Mechanical Engineering, P.O. Box 68.503, 21.941.972 Rio de Janeiro, RJ (Brazil); Souza de Paula, Aline, E-mail: alinedepaula@unb.br [Universidade de Brasi' lia, Department of Mechanical Engineering, 70.910.900 Brasilia, DF (Brazil); Amorim Savi, Marcelo, E-mail: savi@mecanica.ufrj.br [Universidade Federal do Rio de Janeiro, COPPE, Department of Mechanical Engineering, P.O. Box 68.503, 21.941.972 Rio de Janeiro, RJ (Brazil)

    2011-08-15

    Highlights: > A natural cardiac pacemaker is modeled by a modified Van der Pol oscillator. > Responses related to normal and chaotic, pathological functioning of the heart are investigated. > Chaos control methods are applied to avoid pathological behaviors of heart dynamics. > Different approaches are treated: stabilization of unstable periodic orbits and chaos suppression. - Abstract: The dynamics of cardiovascular rhythms have been widely studied due to the key aspects of the heart in the physiology of living beings. Cardiac rhythms can be either periodic or chaotic, being respectively related to normal and pathological physiological functioning. In this regard, chaos control methods may be useful to promote the stabilization of unstable periodic orbits using small perturbations. In this article, the extended time-delayed feedback control method is applied to a natural cardiac pacemaker described by a mathematical model. The model consists of a modified Van der Pol equation that reproduces the behavior of this pacemaker. Results show the ability of the chaos control strategy to control the system response performing either the stabilization of unstable periodic orbits or the suppression of chaotic response, avoiding behaviors associated with critical cardiac pathologies.

  5. Precision temperature controlled filtered laminar air enclosure

    International Nuclear Information System (INIS)

    We demonstrate a novel temperature controlled filtered laminar air enclosure composed of primarily off-the-shelf components that can be applied to a broad class of systems to significantly enhance their performance. An air mixing method is employed to provide variable cooling of the incoming filtered air, providing a temperature stability of ± 0.02 °C within the enclosure. The method is inexpensive to implement, and is suitable for a wide range of temperature controlled enclosures, with dimensions in the approximate range from 1 m to 5 m, making it ideal for many scientific applications. (technical design note)

  6. Central control of body temperature.

    Science.gov (United States)

    Morrison, Shaun F

    2016-01-01

    Central neural circuits orchestrate the behavioral and autonomic repertoire that maintains body temperature during environmental temperature challenges and alters body temperature during the inflammatory response and behavioral states and in response to declining energy homeostasis. This review summarizes the central nervous system circuit mechanisms controlling the principal thermoeffectors for body temperature regulation: cutaneous vasoconstriction regulating heat loss and shivering and brown adipose tissue for thermogenesis. The activation of these thermoeffectors is regulated by parallel but distinct efferent pathways within the central nervous system that share a common peripheral thermal sensory input. The model for the neural circuit mechanism underlying central thermoregulatory control provides a useful platform for further understanding of the functional organization of central thermoregulation, for elucidating the hypothalamic circuitry and neurotransmitters involved in body temperature regulation, and for the discovery of novel therapeutic approaches to modulating body temperature and energy homeostasis. PMID:27239289

  7. Central control of body temperature

    Science.gov (United States)

    Morrison, Shaun F.

    2016-01-01

    Central neural circuits orchestrate the behavioral and autonomic repertoire that maintains body temperature during environmental temperature challenges and alters body temperature during the inflammatory response and behavioral states and in response to declining energy homeostasis. This review summarizes the central nervous system circuit mechanisms controlling the principal thermoeffectors for body temperature regulation: cutaneous vasoconstriction regulating heat loss and shivering and brown adipose tissue for thermogenesis. The activation of these thermoeffectors is regulated by parallel but distinct efferent pathways within the central nervous system that share a common peripheral thermal sensory input. The model for the neural circuit mechanism underlying central thermoregulatory control provides a useful platform for further understanding of the functional organization of central thermoregulation, for elucidating the hypothalamic circuitry and neurotransmitters involved in body temperature regulation, and for the discovery of novel therapeutic approaches to modulating body temperature and energy homeostasis. PMID:27239289

  8. Photoirradiation system with temperature control

    International Nuclear Information System (INIS)

    During application of phototherapy is possible to induce a significant increase in tissue temperature and generate a localized hyperthermia state if the power density of incident light is high enough. We present a controlled temperature phototherapy system, this allows the application of optical radiation at a wavelength of 630nm using a light emitting diode (LED) of high power. The system automatically controls the irradiation time and power which allows irradiating the tissue with an appropriate energy density. A thermocouple is placed in the irradiated tissue to measure and control the temperature by varying the parameters of power density and time. From results of irradiations made in nu / nu mice using doses of 150 J/cm2 energy and 250 J/cm2 shows that the temperature control allows the study of photodynamic therapy in synergy with thermo therapy in different diseases external tissues. (Author)

  9. Uranium casting furnace automatic temperature control development

    International Nuclear Information System (INIS)

    Development of an automatic molten uranium temperature control system for use on batch-type induction casting furnaces is described. Implementation of a two-color optical pyrometer, development of an optical scanner for the pyrometer, determination of furnace thermal dynamics, and design of control systems are addressed. The optical scanning system is shown to greatly improve pyrometer measurement repeatability, particularly where heavy floating slag accumulations cause surface temperature gradients. Thermal dynamics of the furnaces were determined by applying least-squares system identification techniques to actual production data. A unity feedback control system utilizing a proportional-integral-derivative compensator is designed by using frequency-domain techniques. 14 refs

  10. Voltammetry under a Controlled Temperature Gradient

    OpenAIRE

    Jan Krejci, Jr.; Tomas Marvanek; Zuzana Sajdlova; Jan Krejci

    2010-01-01

    Electrochemical measurements are generally done under isothermal conditions. Here we report on the application of a controlled temperature gradient between the working electrode surface and the solution. Using electrochemical sensors prepared on ceramic materials with extremely high specific heat conductivity, the temperature gradient between the electrode and solution was applied here as a second driving force. This application of the Soret phenomenon increases the mass transfer in the Nerns...

  11. Digital control programmer for temperature control

    International Nuclear Information System (INIS)

    This report describes a PC based digital control programmer for controlling and programming temperature of a high vacuum resistance heating furnace and the software developed to control power using PID algorithm. It also describes the amplifier specially developed to suit the input requirement of the non-standard W5 thermocouple and the software and hardware protections introduced in the system. (author). 5 refs., 8 figs., 1 appendix

  12. Heat pipes for temperature control

    International Nuclear Information System (INIS)

    Heat pipes have known for years as effective constructional elements for temperature control. With the aid of special techniques (gas, liquid, steam, and voltage control), special operating characteristics can be obtained, e.g. variable heat conduction or diode behaviour. Their main field of application is in spacecraft technology and in nuclear technology in the isothermalisation of irradiation capsules. The different control techniques are presented and critically evaluated on the basis of characteristic properties like heat transfer capacity, volume and mass requirements, complexity of structure and production, reliability, and temperature control characteristics. Advantages and shortcomings of the different concepts are derived and compared. The state of the art of these control techniques is established on the basis of four development levels. Finally, the necessity and direction of further R + D activities are discussed, and suggestions are made for further work. (orig./HP)

  13. Robustness analysis applied to substructure controller synthesis

    Science.gov (United States)

    Gonzalez-Oberdoerffer, Marcelo F.; Craig, Roy R., Jr.

    1993-01-01

    The stability and robustness of the controlled system obtained via the substructure control synthesis (SCS) method of Su et al. (1990) were examined using a six-bay truss model, and employing an LQG control design method to obtain controllers for two separate structures. It is found that the assembled controller provides a stability in this instance. A qualitative assessment of the stability robustness of the system with controller designed with the SCS method is provided by obtaining a controller using the complete truss model and comparing the robustness of the corresponding closed-loop systems.

  14. Apply a hydrological model to estimate local temperature trends

    International Nuclear Information System (INIS)

    Continuous times series {f(x)} such as a depth of water is written f(x) = T(x)+P(x)+S(x)+C(x) in hydrological science where T(x),P(x),S(x) and C(x) are called the trend, periodic, stochastic and catastrophic components respectively. We simplify this model and apply it to the local temperature data such as given E. Halley (1693), the UK (1853-2010), Germany (1880-2010), Japan (1876-2010). We also apply the model to CO2 data. The model coefficients are evaluated by a symbolic computation by using a standard personal computer. The accuracy of obtained nonlinear curve is evaluated by the arithmetic mean of relative errors between the data and estimations. E. Halley estimated the temperature of Gresham College from 11/1692 to 11/1693. The simplified model shows that the temperature at the time rather cold compared with the recent of London. The UK and Germany data sets show that the maximum and minimum temperatures increased slowly from the 1890s to 1940s, increased rapidly from the 1940s to 1980s and have been decreasing since the 1980s with the exception of a few local stations. The trend of Japan is similar to these results

  15. Fuzzy Logic Controller for Low Temperature Application

    Science.gov (United States)

    Hahn, Inseob; Gonzalez, A.; Barmatz, M.

    1996-01-01

    The most common temperature controller used in low temperature experiments is the proportional-integral-derivative (PID) controller due to its simplicity and robustness. However, the performance of temperature regulation using the PID controller depends on initial parameter setup, which often requires operator's expert knowledge on the system. In this paper, we present a computer-assisted temperature controller based on the well known.

  16. Automatic control of finite element models for temperature-controlled radiofrequency ablation

    Directory of Open Access Journals (Sweden)

    Haemmerich Dieter

    2005-07-01

    Full Text Available Abstract Background The finite element method (FEM has been used to simulate cardiac and hepatic radiofrequency (RF ablation. The FEM allows modeling of complex geometries that cannot be solved by analytical methods or finite difference models. In both hepatic and cardiac RF ablation a common control mode is temperature-controlled mode. Commercial FEM packages don't support automating temperature control. Most researchers manually control the applied power by trial and error to keep the tip temperature of the electrodes constant. Methods We implemented a PI controller in a control program written in C++. The program checks the tip temperature after each step and controls the applied voltage to keep temperature constant. We created a closed loop system consisting of a FEM model and the software controlling the applied voltage. The control parameters for the controller were optimized using a closed loop system simulation. Results We present results of a temperature controlled 3-D FEM model of a RITA model 30 electrode. The control software effectively controlled applied voltage in the FEM model to obtain, and keep electrodes at target temperature of 100°C. The closed loop system simulation output closely correlated with the FEM model, and allowed us to optimize control parameters. Discussion The closed loop control of the FEM model allowed us to implement temperature controlled RF ablation with minimal user input.

  17. Intelligent temperature control system of quench furnace

    Institute of Scientific and Technical Information of China (English)

    胡燕瑜; 桂卫华; 唐朝晖; 唐玲

    2004-01-01

    A fuzzy-neural networks intelligent temperature control system of quench furnace was presented. Combined genetic algorithm with back-propagation algorithm, the weight values of neural networks, parameters of fuzzy membership functions and inference rules can be adjusted automatically, which realizes the optimal control of temperature. The results show that this control system can run effectively with satisfied temperature precision: in temperature uprising stage, overshot of temperature is under 4 ℃; in stable stage, the scope of temperature change is controlled within ±2 ℃, which meets the need of control veracity of temperature.

  18. Applying GPS to check horizontal control quality

    OpenAIRE

    Jakub Vincent; Weiss Gabriel; Sabová Jana

    2004-01-01

    GPS technologies can also be used for check quality in available horizontal point set with coordinates CJ of the frame S-JTSK. When survey and setting-out tasks should be performed in certain area, one can found in it allways some points of the fundamental and detail state controls. To use these points for some actual aims, it is necessary to investigate their compatibility (among the point mark positions and the point coordinate of control points). This can be done using GPS surveying that m...

  19. Applying interactive control to waste processing operations

    International Nuclear Information System (INIS)

    At present waste and residue processing includes steps that require human interaction. The risk of exposure to unknown hazardous materials and the potential for radiation contamination motivates the desire to remove operators from these processes. Technologies that facilitate this include glove box robotics, modular systems for remote and automated servicing, and interactive controls that minimize human intervention. LLNL is developing an automated system which is designed to supplant the operator for glove box tasks, thus protecting the operator from the risk of radiation exposure and minimizing operator-associated waste. Although most of the processing can be automated with minimal human interaction, there are some tasks where intelligent intervention is both desirable and necessary to adapt to Enexpected circumstances and events. These activities require that the operator interact with the process using a remote manipulator which provides or reflects a natural feel to the operator. The remote manipulation system which was developed incorporates sensor fusion and interactive control, and provides the operator with an effective means of controlling the robot in a potentially unknown environment. This paper describes recent accomplishments in technology development and integration, and outlines the future goals of Lawrence Livermore National Laboratory for achieving this integrated interactive control capability

  20. Clumped Isotopes Applied to Carbonate Diagenesis and High Temperature Systems

    Science.gov (United States)

    John, C. M.; Jourdan, A.; Kluge, T.; Dale, A.; Davis, S.; Vandeginste, V.

    2012-12-01

    The field of clumped isotopes is concerned with the state of ordering of natural substances and aims at constraining the abundance of 18O-13C bonds (i.e. a 'clump') within the lattice of carbonate minerals. Measuring the difference between the abundance of 18O-13C bonds in a sample relative to a stochastic distribution of isotopologues offers a single-phase paleothermometer applicable to all carbonate phases. Most of the applications of clumped isotopes to date have been in the field of paleoclimate, but applications to diagenetic systems are becoming more common. The independence of clumped isotopes from the isotopic composition of the diagenetic fluid reduces ambiguities when interpreting paragenesis, fluid flow history, and thermal history of basins. This presentation will synthesize the results of several projects within our group that collectively aim at understanding and applying clumped isotopes to diagenetic systems. One example of project including diagenesis and clumped isotope is a study of low-temperature diagenetic calcite in a salt dome in Oman (Jebel Madar). Jebel Madar is an ideal case study as large fracture-related crystals can be sampled for both clumped isotopes and fluid inclusions. Results show a good match between single-phase fluid inclusions suggesting temperature of precipitations below 90-50°C, and clumped isotope data measured on the same crystals. The low-temperature study reveals the history of gradual cooling and progressive mixing between two sources of diagenetic fluids in the fracture of Jebel Madar, and highlights the potential of clumped isotope for diagenetic studies. However, applications at high-temperatures are currently more challenging because of the lack of empirical calibrations above 50°C. A second project is thus focused on a series of high-temperature lab precipitation experiments for calibrations at high temperature, while a third project explores applicability of clumped isotopes to cemented siliciclastic units

  1. Improved temperature control of liquid cooling garments

    Science.gov (United States)

    Flucher, C. W. G.

    1972-01-01

    Skin and auditory meatus temperature readings supply control signal for temperature control valve in fluid temperature control system which provides increased subject comfort and responds to directly measured physiological cooling needs. System applications include medical care and thermal protection garment manufacturing.

  2. Applied optimal control theory of distributed systems

    CERN Document Server

    Lurie, K A

    1993-01-01

    This book represents an extended and substantially revised version of my earlierbook, Optimal Control in Problems ofMathematical Physics,originally published in Russian in 1975. About 60% of the text has been completely revised and major additions have been included which have produced a practically new text. My aim was to modernize the presentation but also to preserve the original results, some of which are little known to a Western reader. The idea of composites, which is the core of the modern theory of optimization, was initiated in the early seventies. The reader will find here its implementation in the problem of optimal conductivity distribution in an MHD-generatorchannel flow.Sincethen it has emergedinto an extensive theory which is undergoing a continuous development. The book does not pretend to be a textbook, neither does it offer a systematic presentation of the theory. Rather, it reflects a concept which I consider as fundamental in the modern approach to optimization of dis­ tributed systems. ...

  3. Linear and Nonlinear Controllers Applied to Fixed-Wing UAV

    Directory of Open Access Journals (Sweden)

    Tadeo Espinoza

    2013-01-01

    Full Text Available This article presents a comparison of controllers which have been applied to a fixed‐wing Unmanned Aerial Vehicle (UAV. The comparison is realized between classical linear controllers and nonlinear control laws. The concerned linear controllers are: Proportional‐ Derivative (PD and Proportional‐Integral‐Derivative (PID, while the nonlinear controllers are: backstepping, sliding modes, nested saturation and fuzzy control. These controllers are compared and analysed for altitude, yaw and roll by using simulation tests.

  4. Linear and Nonlinear Controllers Applied to Fixed-Wing UAV

    OpenAIRE

    Tadeo Espinoza; Alejandro Dzul; Miguel Llama

    2013-01-01

    This article presents a comparison of controllers which have been applied to a fixed‐wing Unmanned Aerial Vehicle (UAV). The comparison is realized between classical linear controllers and nonlinear control laws. The concerned linear controllers are: Proportional‐ Derivative (PD) and Proportional‐Integral‐Derivative (PID), while the nonlinear controllers are: backstepping, sliding modes, nested saturation and fuzzy control. These controllers are compared and analysed for altitude, yaw and rol...

  5. Pressure Controlled Heat Pipe for Precise Temperature Control Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Small Business Innovation Research project will develop Pressure Controlled Heat Pipes (PCHPs) for precise temperature control (milli-Kelvin level). Several...

  6. Design of Greenhouse Temperature and Light Intensity Control Circuit

    Institute of Scientific and Technical Information of China (English)

    Chao; ZHANG

    2014-01-01

    In view of domestic scientific and technological achievements at present,real-time control circuit for greenhouse temperature and light intensity has been designed in line with the principle of cost saving and easy control.With advanced temperature sensor and light sensor applied to measure the temperature and light intensity,an execution unit is controlled by single-chip microcomputer(SCM)to regulate the temperature and light intensity,creating a hardware design scheme and software design idea.In case of high temperature and high light intensity in greenhouse,the sunshade net will be put down and the blower will be started automatically;in case of low temperature and light intensity,the sunshade net will be folded up and the heating valve will be turned up automatically.In this way,the temperature and light intensity in greenhouse will be controlled within the designed range.

  7. Versatile microcomputer-based temperature controller

    Energy Technology Data Exchange (ETDEWEB)

    Yarberry, V.R.

    1980-09-01

    The wide range of thermal responses required in laboratory and scientific equipment requires a temperature controller with a great deal of flexibility. While a number of analog temperature controllers are commercially available, they have certain limitations, such as inflexible parameter control or insufficient precision. Most lack digital interface capabilities--a necessity when the temperature controller is part of a computer-controlled automatic data acquisition system. We have developed an extremely versatile microcomputer-based temperature controller to fulfill this need in a variety of equipment. The control algorithm used allows optimal tailoring of parameters to control overshoot, response time, and accuracy. This microcomputer-based temperature controller can be used as a standalone instrument (with a teletype used to enter para-meters), or it can be integrated into a data acquisition system (with a computer used to pass parameters by way of an IEE-488 instrumentation bus).

  8. Precision temperature controller for laser diodes

    Science.gov (United States)

    Doermann, Alex; Troxel, Daylin; Jones, Tyler; Erickson, Christopher; Durfee, Dallin

    2010-10-01

    I will present the motivation, theory of operation, and some of the results found with the temperature controller used in Dr. Durfee's lab. I will also present my goal and possible data of the temperature drift as I attempt to make if more effective than a commercial temperature controller already in the lab.

  9. Optimal control of reactor temperatures using reactivity

    International Nuclear Information System (INIS)

    Modern control theory provides for better system performance through feedback of the internal system states, state feedback. The classical reactor power control loop normally adjusts control rod reactivity to change power through feedback of the output variable only, output feedback. Improved plant performance could be achieved with tight control of reactor temperatures as well. A new technique to improve performance of reactor temperatures is presented in this paper, which modifies reactor power demand signal to the classical control with optimal state feedback

  10. Intelligent control schemes applied to Automatic Generation Control

    Directory of Open Access Journals (Sweden)

    Dingguo Chen

    2016-04-01

    Full Text Available Integrating ever increasing amount of renewable generating resources to interconnected power systems has created new challenges to the safety and reliability of today‟s power grids and posed new questions to be answered in the power system modeling, analysis and control. Automatic Generation Control (AGC must be extended to be able to accommodate the control of renewable generating assets. In addition, AGC is mandated to operate in accordance with the NERC‟s Control Performance Standard (CPS criteria, which represent a greater flexibility in relaxing the control of generating resources and yet assuring the stability and reliability of interconnected power systems when each balancing authority operates in full compliance. Enhancements in several aspects to the traditional AGC must be made in order to meet the aforementioned challenges. It is the intention of this paper to provide a systematic, mathematical formulation for AGC as a first attempt in the context of meeting the NERC CPS requirements and integrating renewable generating assets, which has not been seen reported in the literature to the best knowledge of the authors. Furthermore, this paper proposes neural network based predictive control schemes for AGC. The proposed controller is capable of handling complicated nonlinear dynamics in comparison with the conventional Proportional Integral (PI controller which is typically most effective to handle linear dynamics. The neural controller is designed in such a way that it has the capability of controlling the system generation in the relaxed manner so the ACE is controlled to a desired range instead of driving it to zero which would otherwise increase the control effort and cost; and most importantly the resulting system control performance meets the NERC CPS requirements and/or the NERC Balancing Authority’s ACE Limit (BAAL compliance requirements whichever are applicable.

  11. Evaluation of Controller Tuning Methods Applied to Distillation Column Control

    DEFF Research Database (Denmark)

    Nielsen, Kim; W. Andersen, Henrik; Kümmel, Professor Mogens;

    1998-01-01

    A frequency domain approach is used to compare the nominal performance and robustness of dual composition distillation column control tuned according to Ziegler-Nichols (ZN) and Biggest Log Modulus Tuning (BLT) for three binary distillation columns, WOBE, LUVI and TOFA. The scope of this is to...... examine whether ZN and BLT design yield satisfactory control of distillation columns. Further, PI controllers are tuned according to a proposed multivariable frequency domain method. A major conclusion is that the ZN tuned controllers yield undesired overshoot and oscillation and poor stability robustness...

  12. Oscillating system design applying universal formula for control

    OpenAIRE

    Efimov, Denis; Perruquetti, Wilfrid

    2011-01-01

    The problem of oscillating system design applying the homogeneity approach is studied. The Anti-control Lyapunov Function (ALF) is introduced as a counterpart of Control Lyapunov Function (CLF) for the control design that destabilizes a nonlinear system. A universal anti-control formula is proposed. Next, the universal control formulas based on ALF and CLF are used to design an oscillating system. Efficiency of the proposed approach is demonstrated on example.

  13. Biophysical control of leaf temperature

    Science.gov (United States)

    Dong, N.; Prentice, I. C.; Wright, I. J.

    2014-12-01

    In principle sunlit leaves can maintain their temperatures within a narrower range than ambient temperatures. This is an important and long-known (but now overlooked) prediction of energy balance theory. Net radiation at leaf surface in steady state (which is reached rapidly) must be equal to the combination of sensible and latent heat exchanges with surrounding air, the former being proportional to leaf-to-air temperature difference (ΔT), the latter to the transpiration rate. We present field measurements of ΔT which confirm the existence of a 'crossover temperature' in the 25-30˚C range for species in a tropical savanna and a tropical rainforest environment. This finding is consistent with a simple representation of transpiration as a function of net radiation and temperature (Priestley-Taylor relationship) assuming an entrainment factor (ω) somewhat greater than the canonical value of 0.26. The fact that leaves in tropical forests are typically cooler than surrounding air, often already by solar noon, is consistent with a recently published comparison of MODIS day-time land-surface temperatures with air temperatures. Theory further predicts a strong dependence of leaf size (which is inversely related to leaf boundary-layer conductance, and therefore to absolute magnitude of ΔT) on moisture availability. Theoretically, leaf size should be determined by either night-time constraints (risk of frost damage to active leaves) or day-time constraints (risk of heat stress damage),with the former likely to predominate - thereby restricting the occurrence of large leaves - at high latitudes. In low latitudes, daytime maximum leaf size is predicted to increase with temperature, provided that water is plentiful. If water is restricted, however, transpiration cannot proceed at the Priestley-Taylor rate, and it quickly becomes advantageous for plants to have small leaves, which do not heat up much above the temperature of their surroundings. The difference between leaf

  14. Applying Statistical Process Control to Clinical Data: An Illustration.

    Science.gov (United States)

    Pfadt, Al; And Others

    1992-01-01

    Principles of statistical process control are applied to a clinical setting through the use of control charts to detect changes, as part of treatment planning and clinical decision-making processes. The logic of control chart analysis is derived from principles of statistical inference. Sample charts offer examples of evaluating baselines and…

  15. Temperature Control System Using Fuzzy Logic Technique

    Directory of Open Access Journals (Sweden)

    Isizoh A N

    2012-06-01

    Full Text Available Fuzzy logic technique is an innovative technology used in designing solutions for multi-parameter and non-linear control models for the definition of a control strategy. As a result, it delivers solutions faster than the conventional control design techniques. This paper thus presents a fuzzy logic based-temperature control system, which consists of a microcontroller, temperature sensor, and operational amplifier, Analogue to Digital Converter, display interface circuit and output interface circuit. It contains a design approach that uses fuzzy logic technique to achieve a controlled temperature output function.

  16. Modeling Validation and Control Analysis for Controlled Temperature and Humidity of Air Conditioning System

    OpenAIRE

    Jing-Nang Lee; Tsung-Min Lin; Chien-Chih Chen

    2014-01-01

    This study constructs an energy based model of thermal system for controlled temperature and humidity air conditioning system, and introduces the influence of the mass flow rate, heater and humidifier for proposed control criteria to achieve the controlled temperature and humidity of air conditioning system. Then, the reliability of proposed thermal system model is established by both MATLAB dynamic simulation and the literature validation. Finally, the PID control strategy is applied for con...

  17. The viscoplasticity theory applied to the inelastic analysis at elevated temperatures

    International Nuclear Information System (INIS)

    Monotonic and cyclic loading tests on strain rate changes are conducted on 2 1/4Cr-1Mo steel at 600deg C. The examination of the tensile stress-strain response suggests that the viscosity function which characterizes the rate-dependency in the viscosity theory used previously at room temperature should not only depend on the overstress but also on the strain. A new extended viscosity control function is introduced to represent such strain dependency. The material constants of this modified viscoplasticity model are determined at temperatures of 25deg C to 600deg C and the model is applied to deformation tests on 2 1/4Cr-1Mo steel carried out under time-varying temperature conditions and other conditions. The extended viscoplasticity theory is shown to reproduce such various experimentally observed stress-strain behavior at elevated temperatures. (orig.)

  18. Research on Applying Bluetooth to an Elevator Wireless Control System

    Institute of Scientific and Technical Information of China (English)

    MA Jian-cang; LUO Ya-jun; ZHAO Yu-ting

    2003-01-01

    Compared with other elevator control systems, the wireless control system has many advanta ges such as easy to install and maintain. Bluetooth is a new technology of short-range wireless communication, and the idea of applying Bluetooth to the elevator wireless control system is expected to get wide application. In this paper, a wireless control prototype system is introduced, and the experimentsof this system proved the feasibility of this idea.

  19. H∞ Control Theory Applied to Xenon Control for Load-Following Operation of a Nuclear Reactor

    International Nuclear Information System (INIS)

    A robust controller is designed by applying the H∞ optimal control theory to the xenon control for the load-following operation of a nuclear reactor. The set of reactor model equations for controller design is a stiff system. This singularly perturbed system arises from the interaction of slow dynamics modes (iodine and xenon concentrations) and fast dynamics modes (neutron density, fuel and coolant temperatures). The singular perturbation technique is used to overcome this stiffness problem. The design specifications are incorporated by the frequency weights using the mixed-sensitivity problem approach. The robustness of H∞ control is demonstrated by comparing it with linear quadratic Gaussian (LQG) control in the case of a measurement delay of the power measurement system.Since the gains and phase margins of H∞ control are larger than those of LQG control, the H∞ control is expected to provide excellent stability robustness and performance robustness against external disturbances and noises, model parameter variations, and modeling errors as well as hardware failures. It may also provide a practical design method because the design specifications can be easily implemented by the frequency weights

  20. Infrared Sensor-Based Temperature Control for Domestic Induction Cooktops

    Directory of Open Access Journals (Sweden)

    Javier Lasobras

    2014-03-01

    Full Text Available In this paper, a precise real-time temperature control system based on infrared (IR thermometry for domestic induction cooking is presented. The temperature in the vessel constitutes the control variable of the closed-loop power control system implemented in a commercial induction cooker. A proportional-integral controller is applied to establish the output power level in order to reach the target temperature. An optical system and a signal conditioning circuit have been implemented. For the signal processing a microprocessor with 12-bit ADC and a sampling rate of 1 Ksps has been used. The analysis of the contributions to the infrared radiation permits the definition of a procedure to estimate the temperature of the vessel with a maximum temperature error of 5 °C in the range between 60 and 250 °C for a known cookware emissivity. A simple and necessary calibration procedure with a black-body sample is presented.

  1. Phase Change Fabrics Control Temperature

    Science.gov (United States)

    2009-01-01

    Originally featured in Spinoff in 1997, Outlast Technologies Inc. (formerly Gateway Technologies Inc.) has built its entire product line on microencapsulated phase change materials, developed in Small Business Innovation Research (SBIR) contracts with Johnson Space Center after initial development for the U.S. Air Force. The Boulder, Colorado-based company acquired the exclusive patent rights and now integrates these materials into textiles or onto finished apparel, providing temperature regulation in bedding materials and a full line of apparel for both ordinary and extreme conditions.

  2. Control of temperature for health and productivity inoffices

    Energy Technology Data Exchange (ETDEWEB)

    Seppanen, Olli; Fisk, William J.; Faulkner, David

    2004-06-01

    Indoor temperature is one of the fundamental characteristics of the indoor environment. It can be controlled with different accuracy depending on the building and its HVAC system. The purpose of this study was to evaluate the potential benefits of improved temperature control, and apply the information for a cost-benefit analyses. The indoor temperature affects several human responses, including thermal comfort, perceived air quality, sick building syndrome symptoms and performance in work. In this study we focused on the effects of temperature on performance in work. We collected and analyzed the literature relating the performance in work and temperature. The results of multiple studies are relatively consistent and show an average relationship of 2% decrement in work performance per degree C when the temperature is above 25 C. Less data were available on the performance in low temperatures. However, studies show a strong effect on manual tasks with temperatures below thermal neutrality as soon as the temperature of hands decreased due to control of blood flow. When the estimated productivity decrement from elevated temperatures was applied to data from a study of night-time ventilative cooling, the estimated value of productivity improvements were 32 to 120 times greater than the cost of energy to run fans during the night.

  3. Finite element models applied in active structural acoustic control

    NARCIS (Netherlands)

    Oude Nijhuis, Marco H.H.; Boer, de André; Rao, Vittal S.

    2002-01-01

    This paper discusses the modeling of systems for active structural acoustic control. The finite element method is applied to model structures including the dynamics of piezoelectric sensors and actuators. A model reduction technique is presented to make the finite element model suitable for controll

  4. Fuzzy cascade control based on control's history for superheated temperature

    Institute of Scientific and Technical Information of China (English)

    WANG Guangjun; LI Gang; SHEN Shuguang

    2007-01-01

    To address the characteristics of the large delay and uncertainty of superheated temperature,a new cascade control system is presented based on control's history.Based on the analysis of the control objects' dynamic characteristics,historical control information (substituting for the deviation change rate) is used as the basis for decision-making of the fuzzy control.Therefore,the changing trend of the controlled variable can be accurately reflected.Furthermore,a proportional component is introduced,the advantages of PID and fuzzy controllers are integrated,and the structure weaknesses of conventional fuzzy controllers are overcome.Simulation shows that this control method can effectively reduce the adverse impact of the delay on control effects and,therefore,exhibit strong adaptability by comparing the superheated temperature control system by this controller with PID and conventional fuzzy controllers.

  5. Statistical modeling of bowing control applied to violin sound synthesis

    OpenAIRE

    Maestre E.; Blaauw M.; Bonada J.; Guaus E.; Perez A.

    2010-01-01

    Excitation-continuous music instrument control patterns are often not explicitly represented in current sound synthesis techniques when applied to automatic performance. Both physical model-based and sample-based synthesis paradigms would benefit from a flexible and accurate instrument control model, enabling the improvement of naturalness and realism. We present a framework for modeling bowing control parameters in violin performance. Nearly non-intrusive sensing techniques allow fo...

  6. Temperature Controlled Filamentation in Argon Gas

    Institute of Scientific and Technical Information of China (English)

    CAO Shi-Ying; KONG Wei-Peng; SONG Zhen-Ming; QIN Yu; LI Ru-Xin; WANG Qing-Yue; ZHANG Zhi-Gang

    2008-01-01

    Temperature controlled filamentation is experimentally demonstrated in a temperature gradient gas-filled tube.The proper position of the tube is heated by a furnace and two ends of the tube are cooled by air. The experimental results show that multiple filaments are shrunken into a single fila.ment or no filament only by increasing the temperature at the beginning of the filament. This technique offers another degree of freedom of controlling the filamentation and opens a new way for intense monocycle pulse generation through gradient temperature in a noble gas.

  7. Application of modern control theory to temperature control of the MBE system

    Science.gov (United States)

    Ishikawa, Takuya; Chan, Yuen Chuen; Nakano, Yoshiaki; Tada, Kunio

    1990-03-01

    The setup of an MBE control system without PID controllers, whereby one microprocessor manages all the Knudsen cells directly, is reported. The model-following algorithm is applied to the temperature control of the Knudsen cells, and improved dynamic response of the cell temperature is obtained compared with that obtained by the conventional PID algorithm. An application of the model-following algorithm to device fabrication is demonstrated.

  8. Automated Greenhouse : Temperature and soil moisture control

    OpenAIRE

    Attalla, Daniela; Tannfelt Wu, Jennifer

    2015-01-01

    In this thesis an automated greenhouse was built with the purpose of investigating the watering system’s reliability and if a desired range of temperatures can be maintained. The microcontroller used to create the automated greenhouse was an Arduino UNO. This project utilizes two different sensors, a soil moisture sensor and a temperature sensor. The sensors are controlling the two actuators which are a heating fan and a pump. The heating fan is used to change the temperature and the pump is ...

  9. Adaptive Control Using Residual Mode Filters Applied to Wind Turbines

    Science.gov (United States)

    Frost, Susan A.; Balas, Mark J.

    2011-01-01

    Many dynamic systems containing a large number of modes can benefit from adaptive control techniques, which are well suited to applications that have unknown parameters and poorly known operating conditions. In this paper, we focus on a model reference direct adaptive control approach that has been extended to handle adaptive rejection of persistent disturbances. We extend this adaptive control theory to accommodate problematic modal subsystems of a plant that inhibit the adaptive controller by causing the open-loop plant to be non-minimum phase. We will augment the adaptive controller using a Residual Mode Filter (RMF) to compensate for problematic modal subsystems, thereby allowing the system to satisfy the requirements for the adaptive controller to have guaranteed convergence and bounded gains. We apply these theoretical results to design an adaptive collective pitch controller for a high-fidelity simulation of a utility-scale, variable-speed wind turbine that has minimum phase zeros.

  10. Internal Temperature Control For Vibration Testers

    Science.gov (United States)

    Dean, Richard J.

    1996-01-01

    Vibration test fixtures with internal thermal-transfer capabilities developed. Made of aluminum for rapid thermal transfer. Small size gives rapid response to changing temperatures, with better thermal control. Setup quicker and internal ducting facilitates access to parts being tested. In addition, internal flows smaller, so less energy consumed in maintaining desired temperature settings.

  11. Finite element models applied in active structural acoustic control

    OpenAIRE

    Oude Nijhuis, Marco H.H.; de Boer; Rao, Vittal S.

    2002-01-01

    This paper discusses the modeling of systems for active structural acoustic control. The finite element method is applied to model structures including the dynamics of piezoelectric sensors and actuators. A model reduction technique is presented to make the finite element model suitable for controller design. The reduced structural model is combined with an acoustic model which uses the radiation mode concept. For a test case consisting of a rectangular plate with one piezo patch the model re...

  12. Sub-LSB DAC resolution enhancement applied to LLRF control.

    CERN Document Server

    Grecki, M

    2010-01-01

    The digital control systems use the ADCs/DACs as a front-end for analogue signals processing. The paper proposes the solution to enhance the DAC resolution by PWM. The modulation scheme is optimized to the parameters of of LLRF control in FLASH accelerator. For that purpose the genetic algorithm was implemented and applied. The distributed computing was used to speed-up the computations.

  13. GMDH and neural networks applied in temperature sensors monitoring

    International Nuclear Information System (INIS)

    In this work a monitoring system was developed based on the Group Method of Data Handling (GMDH) and Neural Networks (ANNs) methodologies. This methodology was applied to the IEA-R1 research reactor at IPEN by using a database obtained from a theoretical model of the reactor. The IEA-R1 research reactor is a pool type reactor of 5 MW, cooled and moderated by light water, and uses graphite and beryllium as reflector. The theoretical model was developed using the Matlab GUIDE toolbox. The equations are based in the IEA-R1 mass and energy inventory balance and physical as well as operational aspects are taken into consideration. This methodology was developed by using the GMDH algorithm as input variables to the ANNs. The results obtained using the GMDH and ANNs were better than that obtained using only ANNs. (author)

  14. Temperature control of a catalytic converter

    Energy Technology Data Exchange (ETDEWEB)

    Ma, T.T.-H.

    1994-06-08

    In an ic engine having a catalytic convertor, the catalyst heater is controlled in dependence upon an estimate of the temperature of the catalyst so that there is no need for a sensor in the hostile environment of the exhaust. A valve indicative of the catalyst temperature is stored and modified in accordance with a model of the catalyst temperature. The model can be a mathematical mood carried out by a signal processor or an electrical model with the catalyst temperature being represented by the charge stored on a capacitor. (Author)

  15. Human-Machine Systems concepts applied to Control Engineering Education

    OpenAIRE

    Marangé, Pascale; Gellot, François; Riera, Bernard

    2008-01-01

    In this paper, we interest us to Human-Machine Systems (HMS) concepts applied to Education. It is shown how the HMS framework enables to propose original solution in matter of education in the field of control engineering. We focus on practical courses on control of manufacturing systems. The proposed solution is based on an original use of real and large-scale systems instead of simulation. The main idea is to enable the student, whatever his/her level to control the whole system, from novic...

  16. Predictive control applied to an evaporator mathematical model

    Directory of Open Access Journals (Sweden)

    Daniel Alonso Giraldo Giraldo

    2010-07-01

    Full Text Available This paper outlines designing a predictive control model (PCM applied to a mathematical model of a falling film evaporator with mechanical steam compression like those used in the dairy industry. The controller was designed using the Connoisseur software package and data gathered from the simulation of a non-linear mathematical model. A control law was obtained from minimising a cost function sublect to dynamic system constraints, using a quadratic programme (QP algorithm. A linear programming (LP algorithm was used for finding a sub-optimal operation point for the process in stationary state.

  17. Feedwater temperature control methods and systems

    Energy Technology Data Exchange (ETDEWEB)

    Moen, Stephan Craig; Noonan, Jack Patrick; Saha, Pradip

    2014-04-22

    A system for controlling the power level of a natural circulation boiling water nuclear reactor (NCBWR) is disclosed. The system, in accordance with an example embodiment of the present invention, may include a controller configured to control a power output level of the NCBWR by controlling a heating subsystem to adjust a temperature of feedwater flowing into an annulus of the NCBWR. The heating subsystem may include a steam diversion line configured to receive steam generated by a core of the NCBWR and a steam bypass valve configured to receive commands from the controller to control a flow of the steam in the steam diversion line, wherein the steam received by the steam diversion line has not passed through a turbine. Additional embodiments of the invention may include a feedwater bypass valve for controlling an amount of flow of the feedwater through a heater bypass line to the annulus.

  18. Remote System of Temperature Monitoring and Control

    Directory of Open Access Journals (Sweden)

    Vítor Carvalho

    2008-11-01

    Full Text Available This paper presents a system capable of monitoring and control remotely the temperature of a physical space. This work was part of a final year graduation of the Industrial Informatics Course at the Polytechnic Institute of Cávado and Ave. It was developed by an undergraduate student using a LabVIEW custom application with a methodology of on-off control. The local user can use a touch screen display to configure the system setpoint temperature and for overall monitoring. For remote access it can be used any device supporting LabVIEW environment.

  19. Evaluation of hand applied naled thermal fog for Wyeomyia control.

    Science.gov (United States)

    Curtis, G A; Carlson, D B

    1990-09-01

    Tests on the effect of hand applied naled thermal fog, both as a single treatment on one day/week and a single treatment on 3 successive days, did not control Wyeomyia vanduzeei and Wy. mitchellii. Five-min landing/biting counts in a native oak/palm woodland demonstrated that single applications produced an average landing rate decrease of 13%. Treatments 3 days in succession did not suppress the landing rate. PMID:1977876

  20. 超大体积薄壁渡槽施工温控技术及其应用%Temperature Control Technology and Applied Research of Large Volume Thin-wall Aqueduct

    Institute of Scientific and Technical Information of China (English)

    蒋俊峰

    2014-01-01

    Aqueduct engineering is an important link in the south-north water diversion project. The concrete crack control is particularly important because of the characteristic of the aqueduct thin-wall structure. In order to better preferably guide pro-duction and avoid quality problems of engineering, it was needed to analyze and research the mechanism of cracks and rea-sons by combining with the actual construction process strictly control the cracks in mass concrete and aqueduct project con-struction process of hydration heat simulation. Then, the paper was discussed taking heat preservation, water cooling, pouring and dismantles time and anti-cracking measures. Finally, the paper was purposefully put forward effective crack control scheme and measures, which improved the quality of engineering, guiding the project construction and achieved the an-ti-cracking goal of during the construction.%渡槽工程为南水北调工程的一个重要环节,由于渡槽薄壁结构的特点,其混凝土裂缝控制变得尤为重要。为了更好地指导生产,避免工程出现质量问题,需要结合实际施工过程,对大体积混凝土及裂缝需要严格控制的渡槽工程进行施工过程的水化热仿真分析,研究裂缝的机理及产生的原因。对采取保温、通水冷却、浇筑时间及拆模时间等防裂措施进行探讨,有针对性地提出行之有效的温控防裂方案和措施,提高工程质量,指导了工程施工,达到渡槽混凝土施工期防裂的目的。

  1. Optimization of Temperature Controller for Electric Furnace

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Genetic algorithms are based on the principle of natural selection and the optimization of natural generation. We can select the number of the bit strings and mutation rate reasonably, the global optimal solution can be obtained. GAs adopt the binary code as optimizing parameter and this binary code can be used in computer controller easily. This paper studies the application of the GAs to the electric furnace temperature control. When the electric furnace mathematics model varies with the working condition, the parameter of controller can be optimized on line. So the system performance can be improved effectively.

  2. Applying Econometrics to the Carbon Dioxide “Control Knob”

    Directory of Open Access Journals (Sweden)

    Timothy Curtin

    2012-01-01

    Full Text Available This paper tests various propositions underlying claims that observed global temperature change is mostly attributable to anthropogenic noncondensing greenhouse gases, and that although water vapour is recognized to be a dominant contributor to the overall greenhouse gas (GHG effect, that effect is merely a “feedback” from rising temperatures initially resulting only from “non-condensing” GHGs and not at all from variations in preexisting naturally caused atmospheric water vapour (i.e., [H2O]. However, this paper shows that “initial radiative forcing” is not exclusively attributable to forcings from noncondensing GHG, both because atmospheric water vapour existed before there were any significant increases in GHG concentrations or temperatures and also because there is no evidence that such increases have produced measurably higher [H2O]. The paper distinguishes between forcing and feedback impacts of water vapour and contends that it is the primary forcing agent, at much more than 50% of the total GHG gas effect. That means that controlling atmospheric carbon dioxide is unlikely to be an effective “control knob” as claimed by Lacis et al. (2010.

  3. Nonlinear Model-Based Predictive Control applied to Large Scale Cryogenic Facilities

    CERN Document Server

    Blanco Vinuela, Enrique; de Prada Moraga, Cesar

    2001-01-01

    The thesis addresses the study, analysis, development, and finally the real implementation of an advanced control system for the 1.8 K Cooling Loop of the LHC (Large Hadron Collider) accelerator. The LHC is the next accelerator being built at CERN (European Center for Nuclear Research), it will use superconducting magnets operating below a temperature of 1.9 K along a circumference of 27 kilometers. The temperature of these magnets is a control parameter with strict operating constraints. The first control implementations applied a procedure that included linear identification, modelling and regulation using a linear predictive controller. It did improve largely the overall performance of the plant with respect to a classical PID regulator, but the nature of the cryogenic processes pointed out the need of a more adequate technique, such as a nonlinear methodology. This thesis is a first step to develop a global regulation strategy for the overall control of the LHC cells when they will operate simultaneously....

  4. Temperature control type material irradiation device

    International Nuclear Information System (INIS)

    Irradiation specimens are kept in an inner cylindrical tube and immersed in liquid sodium. Sodium flows into the inner cylindrical tube, to irradiate the specimens and the inner cylindrical tube. Generated heat is transferred by way of sodium to the inner cylindrical tube. The inner cylindrical tube comprises a material having a thermal expansion coefficient greater than that of the outer cylindrical tube. If the amount of heat generated by γ-rays in the inner cylindrical tube is reduced due to lowering of the reactor core power, the temperature of the inner cylindrical tube is lowered to decrease the diameter. Accordingly, the gas gap width between the inner cylindrical tube and the outer cylindrical tube is increased upon lowering of the power. As a result, since heat transfer from the inner cylindrical tube to the outer cylindrical tube is worsened to reduce a cooling effect, the temperature in the inner cylindrical tube is elevated. This can prevent temperature fluctuation of the irradiation specimens caused by fluctuation of the reactor core power without replacing the cooling temperature controlling gas and can maintain the temperature of the irradiation specimens constant. (I.N.)

  5. Control of colloids with gravity, temperature gradients, and electric fields

    CERN Document Server

    Sullivan, M; Harrison, C; Austin, R H; Megens, M; Hollingsworth, A; Russel, W B; Cheng Zhen; Mason, T; Chaikin, P M

    2003-01-01

    We have used a variety of different applied fields to control the density, growth, and structure of colloidal crystals. Gravity exerts a body force proportional to the buoyant mass and in equilibrium produces a height-dependent concentration profile. A similar body force can be obtained with electric fields on charged particles (electrophoresis), a temperature gradient on all particles, or an electric field gradient on uncharged particles (dielectrophoresis). The last is particularly interesting since its magnitude and sign can be changed by tuning the applied frequency. We study these effects in bulk (making 'dielectrophoretic bottles' or traps), to control concentration profiles during nucleation and growth and near surfaces. We also study control of non-spherical and optically anisotropic particles with the light field from laser tweezers.

  6. Temperature control strategy for a seal fatigue tester

    Directory of Open Access Journals (Sweden)

    M. Związek

    2008-08-01

    Full Text Available Purpose: The aim of the paper is optimization of a control strategy used in a seal fatigue tester.Design/methodology/approach: Analytical approach has been applied to get an understanding of a heat exchange process. It is required to optimize the control process algorithm.Findings: The initial control algorithm has been improved regarding numerous tests under different operating conditions. The final version of the control program allows to maintain the temperature according to the on-off strategy minimizing the temperature oscillations and potential overshoots.Research limitations/implications: It should be considered a new control strategy based on PID controller.Practical implications: The major component of the tester is the heat exchanger. It consists of a tube and embedded pipe circuit feeding with the external heating or cooling medium. The tube is a cylindrical housing where the seals are assembled at both sides. Two main pumps circulate the medium at a specified flow rate and pressure. The temperature is maintained to hold it almost constant during heating and cooling phases. Two thermocouples are placed close to the seals, and the one in the middle of the heat exchanger tube. The tester is equipped with a control system consisting of a PLC controller and LabView data acquisition application. It is possible to control the device remotely through LAN/WAN networks. The LabView application communicates with the controller via software with the use of PPI (Point-To-Point Interface protocol. A new control algorithm has allowed to perform tests according to testing specification without significant overshoots.Originality/value: On-off control algorithm has been proposed for a combined heating-cooling installation rarely using in the industrial solutions.

  7. 21 CFR 870.4250 - Cardiopulmonary bypass temperature controller.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiopulmonary bypass temperature controller. 870... Cardiopulmonary bypass temperature controller. (a) Identification. A cardiopulmonary bypass temperature controller is a device used to control the temperature of the fluid entering and leaving a heat exchanger....

  8. Urban drainage control applying rational method and geographic information technologies

    Science.gov (United States)

    Aldalur, Beatriz; Campo, Alicia; Fernández, Sandra

    2013-09-01

    The objective of this study is to develop a method of controlling urban drainages in the town of Ingeniero White motivated by the problems arising as a result of floods, water logging and the combination of southeasterly and high tides. A Rational Method was applied to control urban watersheds and used tools of Geographic Information Technology (GIT). A Geographic Information System was developed on the basis of 28 panchromatic aerial photographs of 2005. They were georeferenced with control points measured with Global Positioning Systems (basin: 6 km2). Flow rates of basins and sub-basins were calculated and it was verified that the existing open channels have a low slope with the presence of permanent water and generate stagnation of water favored by the presence of trash. It is proposed for the output of storm drains, the use of an existing channel to evacuate the flow. The solution proposed in this work is complemented by the placement of three pumping stations: one on a channel to drain rain water which will allow the drain of the excess water from the lower area where is located the Ingeniero White city and the two others that will drain the excess liquid from the port area.

  9. Hierarchical control of intelligent machines applied to space station telerobots

    Science.gov (United States)

    Albus, J. S.; Lumia, R.; Mccain, H.

    1987-01-01

    A hierarchical architecture is described which supports space station telerobots in a variety of modes. The system is divided into three hierarchies: task decomposition, world model, and sensory processing. Goals at each level of the task decomposition hierarchy are divided both spatially and temporally into simpler commands for the next lower level. This decomposition is repeated until, at the lowest level, the drive signals to the robot actuators are generated. To accomplish its goals, task decomposition modules must often use information stored in the world model. The purpose of the sensory system is to update the world model as rapidly as possible to keep the model in registration with the physical world. The architecture of the entire control system hierarchy and how it can be applied to space telerobot applications are discussed.

  10. Genetic Algorithm and Fuzzy Tuning PID Controller Applied on Speed Control System for Marine Diesel Engines

    Directory of Open Access Journals (Sweden)

    Naeim Farouk

    2012-11-01

    Full Text Available The degree of speed control of ship machinery effects on the economics and optimization of the machinery configuration and operation. All marine vessel ranging need some sort of speed control system to control and govern the speed of the marine diesel engines. The main focus of this study is to apply and comparative between two specific soft-computing techniques. Fuzzy logic controller and genetic algorithm to design and tuning of PID controller for applied on speed control system of marine diesel engine to get an output with better dynamic and static performance. Simulation results show that the response of system when using genetic algorithm is better and faster than when using fuzzy tuning PID controller.

  11. Implementation of PID and Fuzzy PID controllers for Temperature control in CSTR

    Directory of Open Access Journals (Sweden)

    S. Srinivasulu Raju

    2013-05-01

    Full Text Available Continuous Stirred Tank Reactor (CSTR is an important subject in chemical process and offering a diverse range of researches in the area of the chemical and control engineering. Various control approaches have been applied on CSTR to control its parameters. This paper gives the demonstration about the temperature control of CSTR reactor using a fuzzy PID controller to meet the desired temperature in presence of set point changes. The parameters of PID controller can be calculated by conducting Relay feedback on process. Fuzzy logic is one of the most successful applications of fuzzy set in which the variables are linguistic rather than numeric. The development of an effective methodology for the design of such control systems undoubtedly requires the synthesis of many concepts from artificial intelligence. The most commonly used controller in the industry field is the PID controller. Fuzzy logic controller (FLC provides an alternative to PID controller, especially when the available system models are inexact or unavailable. A FLC is based on a set of control rules (fuzzy rules among linguistic variables. CSTR system is a typical chemical reactor system with complex non-linear dynamic characteristics. The fuzzy PID control algorithm is designed for the flow process station to improve the control performance better than the conventional PID controller. PID controller works well only if the mathematical model of the system could be computed. Hence it is difficult to implement PID control for variable as well as complicated systems. The proposed method can be used to realize data process and advanced control to improve the quality of the control. The simulation is carried out and the simulation results present the flexibility of the CSTR temperature control.

  12. Applying Standard Interfaces to a Process-Control Language

    Science.gov (United States)

    Berthold, Richard T.

    2005-01-01

    A method of applying open-operating-system standard interfaces to the NASA User Interface Language (UIL) has been devised. UIL is a computing language that can be used in monitoring and controlling automated processes: for example, the Timeliner computer program, written in UIL, is a general-purpose software system for monitoring and controlling sequences of automated tasks in a target system. In providing the major elements of connectivity between UIL and the target system, the present method offers advantages over the prior method. Most notably, unlike in the prior method, the software description of the target system can be made independent of the applicable compiler software and need not be linked to the applicable executable compiler image. Also unlike in the prior method, it is not necessary to recompile the source code and relink the source code to a new executable compiler image. Abstraction of the description of the target system to a data file can be defined easily, with intuitive syntax, and knowledge of the source-code language is not needed for the definition.

  13. Identification, Uncertainty Characterization and Robust Control Synthesis Applied to Large Flexible Structures Control

    Science.gov (United States)

    Bayard, David S.; Chiang, Richard Y.

    1996-01-01

    This paper demonstrates an approach to frequency domain identification for the explicit purpose of designing robust H(infinity) controllers. The approach transforms raw experimental data into a plant set estimate directly usable by modern robust control design software(e.g., Matlab Robust Control Toolboxes [11][2]). A key issue in control design from raw data is the question of whether the controller will work when applied to the true system. The main feature fo this approach is that the resulting controller in guaranteed to work as designed(when applied to the true system) to a prescribed statistical confidence. While the overall methodology addresses key theoretical issues, it has at the same time been specifically designed to support practical implementations. A simulation example is included to demonstrate the overall approach.

  14. 14 CFR 23.1157 - Carburetor air temperature controls.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Carburetor air temperature controls. 23... Powerplant Powerplant Controls and Accessories § 23.1157 Carburetor air temperature controls. There must be a separate carburetor air temperature control for each engine....

  15. Impact of individually controlled facially applied air movement on perceived air quality at high humidity

    Energy Technology Data Exchange (ETDEWEB)

    Skwarczynski, M.A. [Faculty of Environmental Engineering, Institute of Environmental Protection Engineering, Department of Indoor Environment Engineering, Lublin University of Technology, Lublin (Poland); International Centre for Indoor Environment and Energy, Department of Civil Engineering, Technical University of Denmark, Copenhagen (Denmark); Melikov, A.K.; Lyubenova, V. [International Centre for Indoor Environment and Energy, Department of Civil Engineering, Technical University of Denmark, Copenhagen (Denmark); Kaczmarczyk, J. [Faculty of Energy and Environmental Engineering, Department of Heating, Ventilation and Dust Removal Technology, Silesian University of Technology, Gliwice (Poland)

    2010-10-15

    The effect of facially applied air movement on perceived air quality (PAQ) at high humidity was studied. Thirty subjects (21 males and 9 females) participated in three, 3-h experiments performed in a climate chamber. The experimental conditions covered three combinations of relative humidity and local air velocity under a constant air temperature of 26 C, namely: 70% relative humidity without air movement, 30% relative humidity without air movement and 70% relative humidity with air movement under isothermal conditions. Personalized ventilation was used to supply room air from the front toward the upper part of the body (upper chest, head). The subjects could control the flow rate (velocity) of the supplied air in the vicinity of their bodies. The results indicate an airflow with elevated velocity applied to the face significantly improves the acceptability of the air quality at the room air temperature of 26 C and relative humidity of 70%. (author)

  16. Local structure of hole-doped manganites: influence of temperature and applied magnetic field

    International Nuclear Information System (INIS)

    We report an extended x-ray absorption fine-structure investigation on the Mn K absorption edge in La1-xCaxMnO3 as a function of temperature and magnetic field. The results provide microscopic evidence that the modifications in the local structure around Mn atomic sites, as a function of temperature and applied magnetic field, are directly related to the magneto-transport properties of these materials. (author)

  17. Parasitic load control system for exhaust temperature control

    Science.gov (United States)

    Strauser, Aaron D.; Coleman, Gerald N.; Coldren, Dana R.

    2009-04-28

    A parasitic load control system is provided. The system may include an exhaust producing engine and a fuel pumping mechanism configured to pressurize fuel in a pressure chamber. The system may also include an injection valve configured to cause fuel pressure to build within the pressure chamber when in a first position and allow injection of fuel from the pressure chamber into one or more combustion chambers of the engine when in a second position. The system may further include a controller configured to independently regulate the pressure in the pressure chamber and the injection of fuel into the one or more combustion chambers, to increase a load on the fuel pumping mechanism, increasing parasitic load on the engine, thereby increasing a temperature of the exhaust produced by the engine.

  18. Modeling and Optimal Control applied to a vector borne disease

    OpenAIRE

    Rodrigues, Helena Sofia; Monteiro, M. Teresa T.; Torres, Delfim F. M.

    2012-01-01

    A model with six mutually-exclusive compartments related to Dengue disease is presented. In this model there are three vector control tools: insecticides (larvicide and adulticide) and mechanical control. The problem is studied using an Optimal Control (OC) approach. The human data for the model is based on the Cape Verde Dengue outbreak. Some control measures are simulated and their consequences analyzed.

  19. Design of Intelligent Control System of Transformer Oil Temperature

    OpenAIRE

    Caijun Xu; Liping Zhang; Yuchen Chen; Zhifeng Liu

    2016-01-01

    in working process of power transformer, which directly affects the safe operation of transformer oil temperature as well as the stability of the network, so vital to transformer oil temperature detection and control. Based on single chip and chip design of digital temperature measurement transformer oil temperature of an intelligent control system. The system uses a digital temperature sensor DS18B20 collection transformer oil temperature, improves the accuracy of the system. The low power c...

  20. Predictive control applied to a water canal prototype

    OpenAIRE

    Canarias, Daniel; Figueiredo, João; Rijo, Manuel

    2006-01-01

    Predictive control is an intelligent tool to manage complex systems. This control strategy is getting more and more application in industrial fields. This paper shows the application of the predictive control methodology to a water distribution canal. Water canals are complex hydraulic systems because they are open and big scale systems, characterized by big delays and great inertia. Many models and control strategies have already been simulated using linear control theory. In the present stu...

  1. Smart building temperature control using occupant feedback

    Science.gov (United States)

    Gupta, Santosh K.

    This work was motivated by the problem of computing optimal commonly-agreeable thermal settings in spaces with multiple occupants. In this work we propose algorithms that take into account each occupant's preferences along with the thermal correlations between different zones in a building, to arrive at optimal thermal settings for all zones of the building in a coordinated manner. In the first part of this work we incorporate active occupant feedback to minimize aggregate user discomfort and total energy cost. User feedback is used to estimate the users comfort range, taking into account possible inaccuracies in the feedback. The control algorithm takes the energy cost into account, trading it off optimally with the aggregate user discomfort. A lumped heat transfer model based on thermal resistance and capacitance is used to model a multi-zone building. We provide a stability analysis and establish convergence of the proposed solution to a desired temperature that minimizes the sum of energy cost and aggregate user discomfort. However, for convergence to the optimal, sufficient separation between the user feedback frequency and the dynamics of the system is necessary; otherwise, the user feedback provided do not correctly reflect the effect of current control input value on user discomfort. The algorithm is further extended using singular perturbation theory to determine the minimum time between successive user feedback solicitations. Under sufficient time scale separation, we establish convergence of the proposed solution. Simulation study and experimental runs on the Watervliet based test facility demonstrates performance of the algorithm. In the second part we develop a consensus algorithm for attaining a common temperature set-point that is agreeable to all occupants of a zone in a typical multi-occupant space. The information on the comfort range functions is indeed held privately by each occupant. Using occupant differentiated dynamically adjusted prices as

  2. An optimized resistor pattern for temperature gradient control in microfluidics

    International Nuclear Information System (INIS)

    In this paper, we demonstrate the possibility of generating high-temperature gradients with a linear temperature profile when heating is provided in situ. Thanks to improved optimization algorithms, the shape of resistors, which constitute the heating source, is optimized by applying the genetic algorithm NSGA-II (acronym for the non-dominated sorting genetic algorithm) (Deb et al 2002 IEEE Trans. Evol. Comput. 6 2). Experimental validation of the linear temperature profile within the cavity is carried out using a thermally sensitive fluorophore, called Rhodamine B (Ross et al 2001 Anal. Chem. 73 4117–23, Erickson et al 2003 Lab Chip 3 141–9). The high level of agreement obtained between experimental and numerical results serves to validate the accuracy of this method for generating highly controlled temperature profiles. In the field of actuation, such a device is of potential interest since it allows for controlling bubbles or droplets moving by means of thermocapillary effects (Baroud et al 2007 Phys. Rev. E 75 046302). Digital microfluidics is a critical area in the field of microfluidics (Dreyfus et al 2003 Phys. Rev. Lett. 90 14) as well as in the so-called lab-on-a-chip technology. Through an example, the large application potential of such a technique is demonstrated, which entails handling a single bubble driven along a cavity using simple and tunable embedded resistors

  3. Design of multivariable feedback control systems via spectral assignment. [as applied to aircraft flight control

    Science.gov (United States)

    Liberty, S. R.; Mielke, R. R.; Tung, L. J.

    1981-01-01

    Applied research in the area of spectral assignment in multivariable systems is reported. A frequency domain technique for determining the set of all stabilizing controllers for a single feedback loop multivariable system is described. It is shown that decoupling and tracking are achievable using this procedure. The technique is illustrated with a simple example.

  4. Exogenously Applied Plant Growth Regulators Enhance the Morpho-Physiological Growth and Yield of Rice under High Temperature.

    Science.gov (United States)

    Fahad, Shah; Hussain, Saddam; Saud, Shah; Hassan, Shah; Ihsan, Zahid; Shah, Adnan N; Wu, Chao; Yousaf, Muhammad; Nasim, Wajid; Alharby, Hesham; Alghabari, Fahad; Huang, Jianliang

    2016-01-01

    A 2-year experiment was conducted to ascertain the effects of exogenously applied plant growth regulators (PGR) on rice growth and yield attributes under high day (HDT) and high night temperature (HNT). Two rice cultivars (IR-64 and Huanghuazhan) were subjected to temperature treatments in controlled growth chambers and four different combinations of ascorbic acid (Vc), alpha-tocopherol (Ve), brassinosteroids (Br), methyl jasmonates (MeJA), and triazoles (Tr) were applied. High temperature severely affected rice morphology, and also reduced leaf area, above-, and below-ground biomass, photosynthesis, and water use efficiency, while increased the leaf water potential of both rice cultivars. Grain yield and its related attributes except number of panicles, were reduced under high temperature. The HDT posed more negative effects on rice physiological attributes, while HNT was more detrimental for grain formation and yield. The Huanghuazhan performed better than IR-64 under high temperature stress with better growth and higher grain yield. Exogenous application of PGRs was helpful in alleviating the adverse effects of high temperature. Among PGR combinations, the Vc+Ve+MejA+Br was the most effective treatment for both cultivars under high temperature stress. The highest grain production by Vc+Ve+MejA+Br treated plants was due to enhanced photosynthesis, spikelet fertility and grain filling, which compensated the adversities of high temperature stress. Taken together, these results will be of worth for further understanding the adaptation and survival mechanisms of rice to high temperature and will assist in developing heat-resistant rice germplasm in future. PMID:27625658

  5. Remote control of magnetostriction-based nanocontacts at room temperature

    Science.gov (United States)

    Jammalamadaka, S. Narayana; Kuntz, Sebastian; Berg, Oliver; Kittler, Wolfram; Kannan, U. Mohanan; Chelvane, J. Arout; Sürgers, Christoph

    2015-09-01

    The remote control of the electrical conductance through nanosized junctions at room temperature will play an important role in future nano-electromechanical systems and electronic devices. This can be achieved by exploiting the magnetostriction effects of ferromagnetic materials. Here we report on the electrical conductance of magnetic nanocontacts obtained from wires of the giant magnetostrictive compound Tb0.3Dy0.7Fe1.95 as an active element in a mechanically controlled break-junction device. The nanocontacts are reproducibly switched at room temperature between “open” (zero conductance) and “closed” (nonzero conductance) states by variation of a magnetic field applied perpendicularly to the long wire axis. Conductance measurements in a magnetic field oriented parallel to the long wire axis exhibit a different behaviour where the conductance switches between both states only in a limited field range close to the coercive field. Investigating the conductance in the regime of electron tunneling by mechanical or magnetostrictive control of the electrode separation enables an estimation of the magnetostriction. The present results pave the way to utilize the material in devices based on nano-electromechanical systems operating at room temperature.

  6. Characteristic study of plasma waves by varying the applied RF frequency and electron temperature in single frequency capacitive discharges

    International Nuclear Information System (INIS)

    In low-pressure capacitive discharges, stochastic heating is the dominant electron heating mechanism which occurs due to the momentum transfer from the oscillating electron sheath edge to electrons. The existence of waves in electron density close to the sheath edge was firstly reported in literature but a comprehensive analysis of their nature has not been discussed. The evidence of wave emission with a frequency near to electron plasma frequency adjacent the sheath territory in case of collisionless plasma in single frequency capacitive discharges was detailed investigated by S Sharma et al. Here the wave properties have been studied by varying the current density amplitude J0 for a constant Radio-Frequency (RF), 27.12 MHz. The electron temperature was also constant (2.5 eV). The field reversal and ion reflection phenomena were reported. In current research work, these waves are studied by varying the frequency of applied RF and keeping other parameters constant. The wave amplitude changes with the frequency of applied RF and the presence of strong field reversal region also observed. The wave properties are also studied by varying the electron temperature Te for applied frequency 27.12 MHz by keeping all other controlling parameters constant. At low values of electron temperature i.e. ∼ 2 eV the strong field reversal emerges. The wave amplitude is also varies by changing electron temperature. (author)

  7. Power-feedwater temperature operating domain for Sbwr applying Monte Carlo simulation

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar M, L. A.; Quezada G, S.; Espinosa M, E. G.; Vazquez R, A.; Varela H, J. R.; Cazares R, R. I.; Espinosa P, G., E-mail: sequega@gmail.com [Universidad Autonoma Metropolitana, Unidad Iztapalapa, San Rafael Atlixco No. 186, Col. Vicentina, 09340 Mexico D. F. (Mexico)

    2014-10-15

    In this work the analyses of the feedwater temperature effects on reactor power in a simplified boiling water reactor (Sbwr) applying a methodology based on Monte Carlo simulation is presented. The Monte Carlo methodology was applied systematically to establish operating domain, due that the Sbwr are not yet in operation, the analysis of the nuclear and thermal-hydraulic processes must rely on numerical modeling, with the purpose of developing or confirming the design basis and qualifying the existing or new computer codes to enable reliable analyses. The results show that the reactor power is inversely proportional to the temperature of the feedwater, reactor power changes at 8% when the feed water temperature changes in 8%. (Author)

  8. Power-feedwater temperature operating domain for Sbwr applying Monte Carlo simulation

    International Nuclear Information System (INIS)

    In this work the analyses of the feedwater temperature effects on reactor power in a simplified boiling water reactor (Sbwr) applying a methodology based on Monte Carlo simulation is presented. The Monte Carlo methodology was applied systematically to establish operating domain, due that the Sbwr are not yet in operation, the analysis of the nuclear and thermal-hydraulic processes must rely on numerical modeling, with the purpose of developing or confirming the design basis and qualifying the existing or new computer codes to enable reliable analyses. The results show that the reactor power is inversely proportional to the temperature of the feedwater, reactor power changes at 8% when the feed water temperature changes in 8%. (Author)

  9. Comparison of three controllers applied to helicopter vibration

    Science.gov (United States)

    Leyland, Jane A.

    1992-01-01

    A comparison was made of the applicability and suitability of the deterministic controller, the cautious controller, and the dual controller for the reduction of helicopter vibration by using higher harmonic blade pitch control. A randomly generated linear plant model was assumed and the performance index was defined to be a quadratic output metric of this linear plant. A computer code, designed to check out and evaluate these controllers, was implemented and used to accomplish this comparison. The effects of random measurement noise, the initial estimate of the plant matrix, and the plant matrix propagation rate were determined for each of the controllers. With few exceptions, the deterministic controller yielded the greatest vibration reduction (as characterized by the quadratic output metric) and operated with the greatest reliability. Theoretical limitations of these controllers were defined and appropriate candidate alternative methods, including one method particularly suitable to the cockpit, were identified.

  10. Applying Statistical Process Quality Control Methodology to Educational Settings.

    Science.gov (United States)

    Blumberg, Carol Joyce

    A subset of Statistical Process Control (SPC) methodology known as Control Charting is introduced. SPC methodology is a collection of graphical and inferential statistics techniques used to study the progress of phenomena over time. The types of control charts covered are the null X (mean), R (Range), X (individual observations), MR (moving…

  11. On the control of structures by applied thermal gradients

    Science.gov (United States)

    Edberg, Don; Chen, JAY-C.

    1987-01-01

    Some preliminary results of research on control of flexible structures performed at the Jet Propulsion Laboratory are presented. It was shown that the thermoelectric device is a feasible actuator and may effectively be used to control structures, provided the structure has a relatively low thermal inertia. The control law only depends on the open-loop system natural frequency.

  12. Touch-sensitive graphics terminal applied to process control

    International Nuclear Information System (INIS)

    Limited initial demonstrations of the system described took place during September 1980. A single CRT was used an an input device in the control center while operating a furnace and a pellet inspection gage. These two process line devices were completely controlled, despite the longer than desired response times noted, using a single control station located in the control center. The operator could conveniently execute any function from this remote location which could be performed locally at the hard-wired control panels. With the installation of the enhancements, the integrated touchscreen/graphics terminal will provide a preferable alternative to normal keyboard command input devices

  13. Applying Econometrics to the Carbon Dioxide “Control Knob”

    OpenAIRE

    Timothy Curtin

    2012-01-01

    This paper tests various propositions underlying claims that observed global temperature change is mostly attributable to anthropogenic noncondensing greenhouse gases, and that although water vapour is recognized to be a dominant contributor to the overall greenhouse gas (GHG) effect, that effect is merely a “feedback” from rising temperatures initially resulting only from “non-condensing” GHGs and not at all from variations in preexisting naturally caused atmospheric water vapour (i.e., [H2O...

  14. Climatology Applied To Architecture: An Experimental Investigation about Internal Temperatures Distribution at Two Test Cells

    Directory of Open Access Journals (Sweden)

    Grace Tibério Cardoso

    2016-04-01

    Full Text Available Data were analyzed en relative spatial distribution of the internal surface temperature (IST and internal air temperature or dry bulb (TBS, in two different test cells, for a typical experimental day under the influence of tropical mass. The main goal of this research is to provide guidelines to collect temperature data experimentally since there is not an appropriate standard to guide this methodological procedure in buildings. The data series of dry bulb temperature and internal surface temperatures were measured in a test cell with a green roof and the other with conventional ceramic roof by thermocouples installed at predetermined locations. The data of solar radiation and the main climatic variables were recorded by the automatic weather station at the Center of Science Engineering Applied to the Environment (CCEAMA, School of Engineering of São Carlos (EESC-USP. The results led to the conclusion that the distribution of the internal surface temperature is almost uniform in the two test cells, but in relation to the dry bulb temperature there is a small vertical temperature gradient in the conventional cell. This work will contribute significantly to future studies in the area of human comfort and environmental suitability of buildings

  15. Temperature Control System for Chromel-Alumel Thermocouple

    International Nuclear Information System (INIS)

    Nuclear Power Plan Operation Safety needs serious handling on temperature measurement and control. In this report has been done manufacturing Temperature Control System for Chromel-Alumel Thermocouple, accordance to material, equipment and human resource ability in the laboratory. Basic component for the Temperature Control System is LM-741 type of Operation Amplifier, which is functionalized as summer for voltage comparator. Function test for this Control System shown its ability for damping on temperature reference. The Temperature Control System will be implemented on PCB Processing Machine. (author)

  16. Design of Multimodel based MPC and IMC control schemes applied to injection molding machine

    Directory of Open Access Journals (Sweden)

    Kanaga Lakshmi

    2014-03-01

    Full Text Available Good control of plastic melt temperature for injection molding is very important in reducing operator setup time, ensuring product quality, and preventing thermal degradation of the melt. The controllability and set points of barrel temperature also depend on the precise monitoring and control of plastic melt temperature. Motivated by the practical temperature control of injection molding, this paper proposes MPC and IMC based control scheme. A robust system identification and control methodology is developed which uses canonical varieties analysis for identification and model predictive control for regulation. The injection molding process consists of three zones and the mathematical model for each of the zone is different. The control output for each zone controller is assigned a weight based on the computed probability of each model and the resulting action is the weighted average of the control moves of the individual zone controllers.   Keywords: Injection-Molding Machine (IMM, IMC Control, Temperature Control.

  17. Investigating the effective factors on management internal controls applying

    Directory of Open Access Journals (Sweden)

    Ahmad Ahmadkhani

    2012-08-01

    Full Text Available Information technology plays an important role on increasing internal control in many organizations. In this paper, we present an empirical study to measure the impact of information technology, hiring high quality skilled management team, using high quality standards and increasing employees' awareness on managing internal control. The survey uses a questionnaire based on Likert scale and distributes among the people who work in either administration or financial sectors of governmental agencies in province of Zanjan, Iran. The results of the study indicate that the implementation of information technology positively influences management team to control their system, more effectively, using more skilled and specialized managers positively influences management internal control, an organization with suitable standard positively influences management internal control and increasing employees' awareness positively influences management internal control.

  18. Applying the CobiT Control Framework to Spreadsheet Developments

    OpenAIRE

    Butler, Raymond J.

    2008-01-01

    One of the problems reported by researchers and auditors in the field of spreadsheet risks is that of getting and keeping managements attention to the problem. Since 1996, the Information Systems Audit & Control Foundation and the IT Governance Institute have published CobiT which brings mainstream IT control issues into the corporate governance arena. This paper illustrates how spreadsheet risk and control issues can be mapped onto the CobiT framework and thus brought to managers attention i...

  19. Applying the CobiT Control Framework to Spreadsheet Developments

    CERN Document Server

    Butler, Raymond J

    2008-01-01

    One of the problems reported by researchers and auditors in the field of spreadsheet risks is that of getting and keeping managements attention to the problem. Since 1996, the Information Systems Audit & Control Foundation and the IT Governance Institute have published CobiT which brings mainstream IT control issues into the corporate governance arena. This paper illustrates how spreadsheet risk and control issues can be mapped onto the CobiT framework and thus brought to managers attention in a familiar format.

  20. Parameter Identification and Adaptive Control Applied to the Inverted Pendulum

    OpenAIRE

    Carlos A. Saldarriaga-Cortés; Víctor D. Correa-Ramírez; Didier Giraldo-Buitrago

    2012-01-01

    This paper presents a methodology to implement an adaptive control of the inverted pendulum system; which uses the recursive square minimum method for the identification of a dynamic digital model of the plant and then, with its estimated parameters, tune in real time a pole placement control. The plant to be used is an unstable and nonlinear system. This fact, combined with the adaptive controller characteristics, allows the obtained results to be extended to a great variety of systems. The ...

  1. New electrohydraulic control system applied to steam turbines

    International Nuclear Information System (INIS)

    A new electrohydraulic control system (EHC) for steam turbines has been developed on the basis of rich operational experience and new requirements on control systems. Its reliability and maintenance have been greatly improved by the use of standardized module circuits. Various new control methods have also been added to meet customers' requirements. A full-size proto-type EHC cabinet has been tested in the EHC test shop in Toshiba, demonstrating its superior performance. (author)

  2. Applied Research of Enterprise Cost Control Based on Linear Programming

    OpenAIRE

    Yu Shuo

    2015-01-01

    As the economic globalization constantly advancing, the competition in the market economy has become even more intense, especially the growing nationalization in the competition among enterprises. The enterprise cost control is essential. Only when the enterprise cost control is within a reasonable range, the corresponding competitiveness of enterprises will be greatly enhanced, so the enterprise cost control is currently the strategy commanding point contended for by all parties. The linear ...

  3. Applying Operating System Principles to SDN Controller Design

    OpenAIRE

    Monaco, Matthew; Michel, Oliver; Keller, Eric

    2015-01-01

    Rather than creating yet another network controller which provides a framework in a specific (potentially new) programming language and runs as a monolithic application, in this paper we extend an existing operating system and leverage its software ecosystem in order to serve as a practical SDN controller. This paper introduces yanc, a controller platform for software-defined networks which exposes the network configuration and state as a file system, enabling user and system applications to ...

  4. Dynamic Control Applied to a Laboratory Antilock Braking System

    Directory of Open Access Journals (Sweden)

    Cuauhtémoc Acosta Lúa

    2015-01-01

    Full Text Available The control of an antilock braking system is a difficult problem due to the existence of nonlinear dynamics and uncertainties of its characteristics. To overcome these issues, in this work, a dynamic nonlinear controller is proposed, based on a nonlinear observer. To evaluate its performance, this controller has been implemented on an ABS Laboratory setup, representing a quarter car model. The nonlinear observer reconstructs some of the state variables of the setup, assumed not measurable, to establish a fair benchmark for an ABS system of a real automobile. The dynamic controller ensures exponential convergence of the state estimation, as well as robustness with respect to parameter variations.

  5. Fuzzy control applied to nuclear power plant pressurizer system

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Mauro V.; Almeida, Jose C.S., E-mail: mvitor@ien.gov.b, E-mail: jcsa@ien.gov.b [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2011-07-01

    In a pressurized water reactor (PWR) nuclear power plants (NPPs) the pressure control in the primary loop is very important for keeping the reactor in a safety condition and improve the generation process efficiency. The main component responsible for this task is the pressurizer. The pressurizer pressure control system (PPCS) utilizes heaters and spray valves to maintain the pressure within an operating band during steady state conditions, and limits the pressure changes, during transient conditions. Relief and safety valves provide overpressure protection for the reactor coolant system (RCS) to ensure system integrity. Various protective reactor trips are generated if the system parameters exceed safe bounds. Historically, a proportional-integral derivative (PID) controller is used in PWRs to keep the pressure in the set point, during those operation conditions. The purpose of this study has two main goals: first is to develop a pressurizer model based on artificial neural networks (ANNs); second is to develop a fuzzy controller for the PWR pressurizer pressure, and compare its performance with the P controller. Data from a simulator PWR plant was used to test the ANN and the controllers as well. The reference simulator is a Westinghouse 3-loop PWR plant with a total thermal output of 2785 MWth. The simulation results show that the pressurizer ANN model response are in reasonable agreement with the simulated power plant, and the fuzzy controller built in this study has better performance compared to the P controller. (author)

  6. Chaos control applied to cardiac rhythms represented by ECG signals

    International Nuclear Information System (INIS)

    The control of irregular or chaotic heartbeats is a key issue in cardiology. In this regard, chaos control techniques represent a good alternative since they suggest treatments different from those traditionally used. This paper deals with the application of the extended time-delayed feedback control method to stabilize pathological chaotic heart rhythms. Electrocardiogram (ECG) signals are employed to represent the cardiovascular behavior. A mathematical model is employed to generate ECG signals using three modified Van der Pol oscillators connected with time delay couplings. This model provides results that qualitatively capture the general behavior of the heart. Controlled ECG signals show the ability of the strategy either to control or to suppress the chaotic heart dynamics generating less-critical behaviors. (paper)

  7. Software factory techniques applied to Process Control at CERN

    CERN Multimedia

    Dutour, MD

    2007-01-01

    The CERN Large Hadron Collider (LHC) requires constant monitoring and control of quantities of parameters to guarantee operational conditions. For this purpose, a methodology called UNICOS (UNIfied Industrial COntrols Systems) has been implemented to standardize the design of process control applications. To further accelerate the development of these applications, we migrated our existing UNICOS tooling suite toward a software factory in charge of assembling project, domain and technical information seamlessly into deployable PLC (Programmable logic Controller) – SCADA (Supervisory Control And Data Acquisition) systems. This software factory delivers consistently high quality by reducing human error and repetitive tasks, and adapts to user specifications in a cost-efficient way. Hence, this production tool is designed to encapsulate and hide the PLC and SCADA target platforms, enabling the experts to focus on the business model rather than specific syntaxes and grammars. Based on industry standard software...

  8. Chaos control applied to cardiac rhythms represented by ECG signals

    Science.gov (United States)

    Borem Ferreira, Bianca; Amorim Savi, Marcelo; Souza de Paula, Aline

    2014-10-01

    The control of irregular or chaotic heartbeats is a key issue in cardiology. In this regard, chaos control techniques represent a good alternative since they suggest treatments different from those traditionally used. This paper deals with the application of the extended time-delayed feedback control method to stabilize pathological chaotic heart rhythms. Electrocardiogram (ECG) signals are employed to represent the cardiovascular behavior. A mathematical model is employed to generate ECG signals using three modified Van der Pol oscillators connected with time delay couplings. This model provides results that qualitatively capture the general behavior of the heart. Controlled ECG signals show the ability of the strategy either to control or to suppress the chaotic heart dynamics generating less-critical behaviors.

  9. Study of fieldbus technology applied in a sterilization plant control and safety systems

    International Nuclear Information System (INIS)

    Several sterilization processes have been used in these years for treatment of countless products. Some processes use high temperatures, thermal shocks and chemical agents. With the discovery of the ionizing radiation and its posterior technological developments turned possible application of that process, in 1960, also in the the sterilization, denominated radiation sterilization. This process became also applied in another areas of health and industrial as food conservation, gemstones enhancement and others. The radiation sterilization requests an effective control and it needs a high level of safety. The commercial use of the computers applied in industrial automation provides and the domain of new technologies in this field provides new applications then new designs now is possible. The Fieldbus technology, a new digital communication protocol, like a Local Area Network, can be an alternative in the cobalt-60 irradiation plant. The present work suggests, evaluates, qualifies and quantifies this possibility. (author)

  10. Parameter Identification and Adaptive Control Applied to the Inverted Pendulum

    Directory of Open Access Journals (Sweden)

    Carlos A. Saldarriaga-Cortés

    2012-06-01

    Full Text Available This paper presents a methodology to implement an adaptive control of the inverted pendulum system; which uses the recursive square minimum method for the identification of a dynamic digital model of the plant and then, with its estimated parameters, tune in real time a pole placement control. The plant to be used is an unstable and nonlinear system. This fact, combined with the adaptive controller characteristics, allows the obtained results to be extended to a great variety of systems. The results show that the above methodology was implemented satisfactorily in terms of estimation, stability and control of such a system. It was established that adaptive techniques have a proper performance even in systems with complex features such as nonlinearity and instability.

  11. Simple operated multipurpose temperature control cryostat

    Institute of Scientific and Technical Information of China (English)

    ABBAS T.A.; OMAR M.S.

    2007-01-01

    A suitable simple optical cryostat for optical, magneto-optical, electrical and thermo-electrical measurements was designed. It is suitable for use in a magnetic pool gap as narrow as less than 1 cm. Throughout a long period of time, the heat diffusion process of the cryostat can be easily operated at slow increase in sample temperature in a range 1.25 K/min at 200 K that will be reduced gradually to 0.66 K at room temperature. Liquid nitrogen was used to cool down the temperature. During the operation, the change in the measured energy gap of a semiconductor sample and other physical parameters resulting from the change of temperature can be corrected through the temperature coefficient of that parameter at the corresponding temperature.The cryostat was successfully used for all experiments mentioned above to measure the properties of a single crystal of GaP (Gallium Phosphate) semiconductor.

  12. Temperature control system for water-perfused suits

    Science.gov (United States)

    Brengelmann, G. L.; Mckeag, M.; Rowell, L. B.

    1977-01-01

    A system used to control skin temperature in human subjects wearing water-perfused garments is described. It supplies 8 l/min at 10 psi with water temperature controlled within plus or minus 0.1 C. Temperature control is facilitated by a low circulating thermal mass and a fast responding heater based on a commercially available quartz heat lamp. The system is open so that hot or cold water can be added from the building mains to produce rates of change of water temperature exceeding 5 C/min. These capabilities allow semiautomatic control of skin temperature within plus or minus 0.1 C of desired wave forms.

  13. Methane reforming in a temperature-controlled DBD reactor

    Science.gov (United States)

    Levko, Dmitry; Raja, Laxminarayan

    2015-09-01

    Methane and carbon dioxide are among the main products of human activity. Therefore, they are considered among greenhouse gases, which may cause the global warming. On the other hand, methane is widely used in everyday life as an energy source and in industry for the synthesis of different chemicals. In order to utilize greenhouse gases or to generate chemicals from methane, one needs first to dissociate it. Then, this gas converts into desired products such as methanol, gasoline, syn-gas etc. Nowadays, there are several methods for CH4 conversion. Steam reforming, partial oxidation, thermal and non-thermal plasmas are among them. During the last decades, the use of non-thermal plasma for methane reforming attracts more and more attention. This is caused by the possibility to control the process of methane conversion as well as the gas component content at the reactor outlet. In addition, the use of non-thermal plasma facilitates the control of reactor start up. The goal of the present work is the deep understanding of the plasma chemical processes accompanying the methane-air conversion in a temperature-controlled DBD reactor. To do this, we have developed the kinetic mechanism of CH4/N2/O2 conversion for the gas temperature range 300-800 K and applied it to the global model.

  14. INCAP ? Applying short-term flexibility to control inventories

    OpenAIRE

    Lödding, Hermann; Lohmann, Steffen

    2011-01-01

    Abstract Inventory Based Capacity Control (INCAP) is a very simple method that allows inventory levels to be effectively controlled by using short-term capacity flexibility in make-to-stock settings. Moreover, INCAP can be used for finished goods inventories as well as for semi-finished goods inventories. The basic idea is to define upper and lower inventory limits and to adjust capacities if the inventory level reaches either limit. Should the inventory fall below the lower limit,...

  15. Designing Crane Controls with applied Mechanical and Electrical Safety Features

    Science.gov (United States)

    Lytle, Bradford P.; Walczak, Thomas A.; Delgado, H. (Technical Monitor)

    2002-01-01

    The use of overhead traveling bridge cranes in many varied applications is common practice. In particular, the use of cranes in the nuclear, military, commercial, aerospace, and other industries can involve safety critical situations. Considerations for Human Injury or Casualty, Loss of Assets, Endangering the Environment, or Economic Reduction must be addressed. Traditionally, in order to achieve additional safety in these applications, mechanical systems have been augmented with a variety of devices. These devices assure that a mechanical component failure shall reduce the risk of a catastrophic loss of the correct and/or safe load carrying capability. ASME NOG-1-1998, (Rules for Construction of Overhead and Gantry Cranes, Top Running Bridge, and Multiple Girder), provides design standards for cranes in safety critical areas. Over and above the minimum safety requirements of todays design standards, users struggle with obtaining a higher degree of reliability through more precise functional specifications while attempting to provide "smart" safety systems. Electrical control systems also may be equipped with protective devices similar to the mechanical design features. Demands for improvement of the cranes "control system" is often recognized, but difficult to quantify for this traditionally "mechanically" oriented market. Finite details for each operation must be examined and understood. As an example, load drift (or small motions) at close tolerances can be unacceptable (and considered critical). To meet these high functional demands encoders and other devices are independently added to control systems to provide motion and velocity feedback to the control drive. This paper will examine the implementation of Programmable Electronic Systems (PES). PES is a term this paper will use to describe any control system utilizing any programmable electronic device such as Programmable Logic Controllers (PLC), or an Adjustable Frequency Drive (AID) 'smart' programmable

  16. Control theory and splines, applied to signature storage

    Science.gov (United States)

    Enqvist, Per

    1994-01-01

    In this report the problem we are going to study is the interpolation of a set of points in the plane with the use of control theory. We will discover how different systems generate different kinds of splines, cubic and exponential, and investigate the effect that the different systems have on the tracking problems. Actually we will see that the important parameters will be the two eigenvalues of the control matrix.

  17. OPTIMAL CONTROL APPLIED IN AUTOMATIC CLUTCH ENGAGEMENTS OF VEHICLES

    Institute of Scientific and Technical Information of China (English)

    Sun Chengshun; Zhang Jianwu

    2004-01-01

    Start-up working condition is the key to the research of optimal engagement of automatic clutch for AMT.In order to guarantee an ideal dynamic performance of the clutch engagement,an optimal controller is designed by considering throttle angle,engine speed,gear ratio,vehicle acceleration and road condition.The minimum value principle is also introduced to achieve an optimal dynamic performance of the nonlinear system compromised in friction plate wear and vehicle drive quality.The optimal trajectory of the clutch engagement can be described in the form of explicit and analytical expressions and characterized by the deterministic and accurate control strategy in stead of indeterministic and soft control techniques which need thousands of experiments.For validation of the controller,test work is carried out for the automated clutch engagements in a commercial car with an traditional mechanical transmission,a hydraulic actuator,a group of sensors and a portable computer system.It is shown through experiments that dynamic behaviors of the clutch engagement operated by the optimal control are more effective and efficient than those by fuzzy control.

  18. Vapor-modulated heat pipe for improved temperature control

    Science.gov (United States)

    Edwards, D. K.; Eninger, J. E.; Ludeke, E. E.

    1978-01-01

    Dryout induced by vapor throttling makes control of equipment temperature less dependent on variations in sink environment. Mechanism controls flow of vapor in heat pipe by using valve in return path to build difference in pressure and also difference in saturation temperature of the vapor. In steady state, valve closes just enough to produce partial dryout that achieves required temperature drop.

  19. GM counter deadtime dependence on applied voltage, operating temperature and fatigue

    International Nuclear Information System (INIS)

    This paper utilized standard two-source method and the simple non-paralyzing model assumption to examine a GM counter's deadtime dependence on applied voltage, operating temperature, and fatigue. Both 60Co and 137Cs sources were used for deadtime measurements. The results gathered suggest the presence of three distinct regions of deadtime behavior. At low voltages, the deadtime decreases as the voltage increases (Region I) followed by a region of stable deadtime plateau (Region II) and finally a region of increasing deadtime with increasing voltage. Region II is the best region for operating with a minimum deadtime which is not sensitive to the applied voltage. Typical deadtime values for GM counters were between 100 and 300 μs; the deadtime values in Region II were within this range. The results examined in this study also indicate a strong temperature dependence of deadtime, with a correlation coefficient of 0.93. The GM counter deadtime for various fatigues (aging) were investigated for three fatigue levels with a correlation coefficient of 0.48. The experimental results confirm that deadtime increases as both temperature and fatigue increase. The fundamental nature of deadtime seems to be different for voltages lower than the stable deadtime plateau (Region II) and for voltages higher than the plateau. - Highlights: • GM counter deadtime dependence on applied voltage, operating temperature and fatigue. • Standard two-source method and simple non-paralyzing model assumption. • Three distinct regions of the deadtime behavior with low deadtime plateau in the middle. • Exponential increase in deadtime with increasing temperature. • Increase in deadtime with fatigue

  20. Temperature Dependence of Magnetization at Zero Applied Magnetic Field in Nearly Two Dimensional Ferromagnets

    International Nuclear Information System (INIS)

    NMR measurement have been made at low temperatures on the crystal structure of K2CuF4 and (C3H7NH3)2CuCl4 at zero applied magnetic field. 63Cu, 65Cu and 35Cl NMR have been used to measure spontaneous magnetization at the temperature range 2 K down to 30 mK. We have made the NMR experiments using a 3He-4He dilution refrigerator by conventional pulsed NMR method without external magnetic field. The magnetization at zero applied magnetic field in the nearly two-dimensional ferromagnet K2CuF4 of the experimental data is in a good agreement with Yamaji-Kondo theory and θc = 0.3, which is applied the double-time Green's function method incorporated with Tyablikov's decoupling. For temperature 1.1 K down to 0.26 K, the spontaneous magnetization of (C3H7NH3)2CuCl4 is support (t log t')-formalism from the spin wave theory.

  1. Applied Research of Enterprise Cost Control Based on Linear Programming

    Directory of Open Access Journals (Sweden)

    Yu Shuo

    2015-01-01

    This paper researches the enterprise cost control through the linear programming model, and analyzes the restriction factors of the labor of enterprise production, raw materials, processing equipment, sales price, and other factors affecting the enterprise income, so as to obtain an enterprise cost control model based on the linear programming. This model can calculate rational production mode in the case of limited resources, and acquire optimal enterprise income. The production guiding program and scheduling arrangement of the enterprise can be obtained through calculation results, so as to provide scientific and effective guidance for the enterprise production. This paper adds the sensitivity analysis in the linear programming model, so as to learn about the stability of the enterprise cost control model based on linear programming through the sensitivity analysis, and verify the rationality of the model, and indicate the direction for the enterprise cost control. The calculation results of the model can provide a certain reference for the enterprise planning in the market economy environment, which have strong reference and practical significance in terms of the enterprise cost control.

  2. A GOMS model applied to a simplified control panel design

    International Nuclear Information System (INIS)

    The design of the user interface for a new system requires many decisions to be considered. To develop sensitivity to user needs requires understanding user behavior. The how-to-do-it knowledge is a mixture of task-related and interface-related components. A conscientious analysis of these components, allows the designer to construct a model in terms of goals, operators, methods, and selection (GOMS model) rules that can be advantageously used in the design process and evaluation of a user interface. The emphasis of the present work is on describing the importance and use of a GOMS model as a formal user interface analysis tool in the development of a simplified panel for the control of a nuclear power plant. At Pennsylvania State University, a highly automated control system with a greatly simplified human interface has been proposed to improve power plant safety. Supervisory control is to be conducted with a simplified control panel with the following functions: startup, shutdown, increase power, decrease power, reset, and scram. Initial programming of the operator interface has been initiated within the framework of a U.S. Department of Energy funded university project for intelligent distributed control. A hypothesis to be tested is that this scheme can be also used to estimate mental work load content and predict human performance

  3. Solution of the neutron point kinetics equations with temperature feedback effects applying the polynomial approach method

    Energy Technology Data Exchange (ETDEWEB)

    Tumelero, Fernanda, E-mail: fernanda.tumelero@yahoo.com.br [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Programa de Pos-Graduacao em Engenharia Mecanica; Petersen, Claudio Z.; Goncalves, Glenio A.; Lazzari, Luana, E-mail: claudiopeteren@yahoo.com.br, E-mail: gleniogoncalves@yahoo.com.br, E-mail: luana-lazzari@hotmail.com [Universidade Federal de Pelotas (DME/UFPEL), Capao do Leao, RS (Brazil). Instituto de Fisica e Matematica

    2015-07-01

    In this work, we present a solution of the Neutron Point Kinetics Equations with temperature feedback effects applying the Polynomial Approach Method. For the solution, we consider one and six groups of delayed neutrons precursors with temperature feedback effects and constant reactivity. The main idea is to expand the neutron density, delayed neutron precursors and temperature as a power series considering the reactivity as an arbitrary function of the time in a relatively short time interval around an ordinary point. In the first interval one applies the initial conditions of the problem and the analytical continuation is used to determine the solutions of the next intervals. With the application of the Polynomial Approximation Method it is possible to overcome the stiffness problem of the equations. In such a way, one varies the time step size of the Polynomial Approach Method and performs an analysis about the precision and computational time. Moreover, we compare the method with different types of approaches (linear, quadratic and cubic) of the power series. The answer of neutron density and temperature obtained by numerical simulations with linear approximation are compared with results in the literature. (author)

  4. Solution of the neutron point kinetics equations with temperature feedback effects applying the polynomial approach method

    International Nuclear Information System (INIS)

    In this work, we present a solution of the Neutron Point Kinetics Equations with temperature feedback effects applying the Polynomial Approach Method. For the solution, we consider one and six groups of delayed neutrons precursors with temperature feedback effects and constant reactivity. The main idea is to expand the neutron density, delayed neutron precursors and temperature as a power series considering the reactivity as an arbitrary function of the time in a relatively short time interval around an ordinary point. In the first interval one applies the initial conditions of the problem and the analytical continuation is used to determine the solutions of the next intervals. With the application of the Polynomial Approximation Method it is possible to overcome the stiffness problem of the equations. In such a way, one varies the time step size of the Polynomial Approach Method and performs an analysis about the precision and computational time. Moreover, we compare the method with different types of approaches (linear, quadratic and cubic) of the power series. The answer of neutron density and temperature obtained by numerical simulations with linear approximation are compared with results in the literature. (author)

  5. Robust sliding mode control applied to double Inverted pendulum system

    International Nuclear Information System (INIS)

    A three hierarchical sliding mode control is presented for a class of an underactuated system which can overcome the mismatched perturbations. The considered underactuated system is a double inverted pendulum (DIP), can be modeled by three subsystems. Such structure allows the construction of several designs of hierarchies for the controller. For all hierarchical designs, the asymptotic stability of every layer sliding mode surface and the sliding mode surface of subsystems are proved theoretically by Barbalat's lemma. Simulation results show the validity of these methods.

  6. COMPUTER VISION APPLIED IN THE PRECISION CONTROL SYSTEM

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Computer vision and its application in the precision control system are discussed. In the process of fabricating, the accuracy of the products should be controlled reasonably and completely. The precision should be kept and adjusted according to the information of feedback got from the measurement on-line or out-line in different procedures. Computer vision is one of the useful methods to do this. Computer vision and the image manipulation are presented, and based on this, a n-dimensional vector to appraise on precision of machining is given.

  7. Metamodeling Techniques Applied to the Design of Reconfigurable Control Applications

    Directory of Open Access Journals (Sweden)

    Luca Ferrarini

    2008-02-01

    Full Text Available In order to realize autonomous manufacturing systems in environments characterized by high dynamics and high complexity of task, it is necessary to improve the control system modelling and performance. This requires the use of better and reusable abstractions. In this paper, we explore the metamodel techniques as a foundation to the solution of this problem. The increasing popularity of model-driven approaches and a new generation of tools to support metamodel techniques are changing software engineering landscape, boosting the adoption of new methodologies for control application development.

  8. Trajectory control with continuous thrust applied to a rendezvous maneuver

    International Nuclear Information System (INIS)

    A rendezvous mission can be divided into the following phases: launch, phasing, far range rendezvous, close range rendezvous and mating (docking or berthing). This paper aims to present a close range rendezvous with closed loop controlled straight line trajectory. The approaching is executed on V-bar axis. A PID controller and continuous thrust are used to eliminate the residual errors in the trajectory. A comparative study about the linear and nonlinear dynamics is performed and the results showed that the linear equations become inaccurate insofar as the chaser moves away from the target

  9. Design of a Neuro-Fuzzy Controller for Speed Control Applied to DC Servo Motor

    Energy Technology Data Exchange (ETDEWEB)

    Kim, S.H.; Kang, Y.H.; Kim, L.K. [Konkuk University, Seoul (Korea); Ko, B.W. [Cheju College of Technology, Cheju (Korea)

    2002-02-01

    In this study, a neuro-fuzzy controller which has the characteristic of fuzzy control and artificial neural network is designed. A fuzzy rule to be applied is automatically selected by the allocated neurons. The neurons correspond to fuzzy rules are created by an expert. To adapt the more precise model is implemented by error back-propagation learning algorithm to adjust the link-weight of fuzzy membership function in the neuro-fuzzy controller. The more classified fuzzy rule is used to include the property of dual mode method. In order to verify the effectiveness of the proposed algorithm designed above, an operating characteristic of a DC servo motor with variable load is investigated. (author). 10 refs., 12 figs., 9 tabs.

  10. Applying Distributed Object Technology to Distributed Embedded Control Systems

    DEFF Research Database (Denmark)

    Jørgensen, Bo Nørregaard; Dalgaard, Lars

    2012-01-01

    In this paper, we describe our Java RMI inspired Object Request Broker architecture MicroRMI for use with networked embedded devices. MicroRMI relieves the software developer from the tedious and error-prone job of writing communication protocols for interacting with such embedded devices. Micro...... developing control systems for distributed embedded platforms possessing severe resource restrictions....

  11. Object oriented programming techniques applied to device access and control

    International Nuclear Information System (INIS)

    In this paper a model, called the device server model, has been presented for solving the problem of device access and control faced by all control systems. Object Oriented Programming techniques were used to achieve a powerful yet flexible solution. The model provides a solution to the problem which hides device dependancies. It defines a software framework which has to be respected by implementors of device classes - this is very useful for developing groupware. The decision to implement remote access in the root class means that device servers can be easily integrated in a distributed control system. A lot of the advantages and features of the device server model are due to the adoption of OOP techniques. The main conclusion that can be drawn from this paper is that 1. the device access and control problem is adapted to being solved with OOP techniques, 2. OOP techniques offer a distinct advantage over traditional programming techniques for solving the device access problem. (J.P.N.)

  12. The development of control technologies applied to waste processing operations

    International Nuclear Information System (INIS)

    Typical waste and residue processes involve some level of human interaction. The risk of exposure to unknown hazardous materials and the potential for radiation contamination provide the impetus for physically separating or removing operators from such processing steps. Technologies that facilitate separation of the operator from potential contamination include glove box robotics; modular systems for remote and automated servicing; and interactive controls that minimize human intervention. Lawrence Livermore National Laboratory (LLNL) is developing an automated system which by design will supplant the operator for glove box tasks, thus affording protection from the risk of radiation exposure and minimizing operator associated waste.This paper describes recent accomplishments in technology development and integration, and outlines the future goals at LLNL for achieving this integrated, interactive control capability

  13. Decision theory applied to image quality control in radiology

    OpenAIRE

    Arantes Paula R; Caous Cristofer A; Lessa Patrícia S; Amaro Edson; de Souza Fernando

    2008-01-01

    Abstract Background The present work aims at the application of the decision theory to radiological image quality control (QC) in diagnostic routine. The main problem addressed in the framework of decision theory is to accept or reject a film lot of a radiology service. The probability of each decision of a determined set of variables was obtained from the selected films. Methods Based on a radiology service routine a decision probability function was determined for each considered group of c...

  14. New infrared radiation temperature measurement system applied to the Laser Flash Method

    International Nuclear Information System (INIS)

    The laser flash method is based on measuring the temperature transient. The effect of the thermal inertia of the temperature measurement system is not negligible and cannot be ignored due to the fast dynamics of the measured thermal transient. This paper presents the new infrared radiation temperature measurement system applied to the thermal diffusivity measurements based on the laser flash method. The developed system consists in a detector cooled in liquid nitrogen, collimating lenses and a mathematical modeling developed in LabView. As a result, the generated electrical signal is converted into temperature. A detailed description of this new temperature measurement system is presented, as well as its mathematical model, computational implementation and calibration. For validate the new system, reference samples of homogeneous materials (Pyroceram 9606 and Inconel 600) were tested and the results of thermal diffusivities were compared with its reference certificates. The thermal diffusivity values measured by using the new system are in agreement with reference values, with less than 2 % of relative deviation

  15. Evaluation on High-temperature Adhesion Performance of Hot-applied Sealant for Asphalt Pavement

    Institute of Scientific and Technical Information of China (English)

    LI Feng; LI Tinggang; SHI Xiaopei

    2014-01-01

    In order to investigate the high-temperature performances of the asphalt pavement hot-applied sealant, as well as to reduce failures of the sealant pullout, the softening point test and the flow test (two existing methods for evaluating high-temperature performances) were conducted. It was found that both tests could not accurately reflect the adhesion performances of the sealant at high temperatures. For this purpose, the adhesion test for PSAT (pressure sensitive adhesive tape) has been taken as a reference to develop a device that is suitable for evaluating the adhesion performances, by modifying relevant test parameters according to the road conditions at high temperatures. Thirteen common sealants were tested in the modified adhesion test, softening point test and flow test. The experimental results show that no significant correlation (p>0.05) exists between the adhesion value, softening point, adhesion value and flow value;while a significant correlation (p<0.05) exists between the softening point and flow value. The modified adhesion test is efficient in distinguishing the high-temperature adhesion performances of different sealants, and can be used as a standard method for evaluating such performances.

  16. High Temperature Fatigue Crack Growth Rate of G91 Steel with Applying 30 Seconds Hold Time

    International Nuclear Information System (INIS)

    Subsection NH since 2004. The database of creep and creep-fatigue crack growth rate of G91 steel is necessary for the structural integrity evaluation of the SFR structures because the database of these properties of materials is insufficient through the world. Moreover, it is difficult to use the database which is gained by the research center of advanced countries because it is not to be opened. Therefore, it is necessary to make an effort to get the database of material properties. Creep-fatigue crack initiation and growth tests for a G91 tubular specimen, including a machined defect, have been performed by Kim and it attempted to assess a high temperature crack behavior of G91 side plate specimen by Lee. Creep-fatigue crack growth rate were compared in terms of different temperature range. Tests were performed at temperatures of 500, 550 and 600, respectively. Stress ratio was set to 0.1 and trapezoidal shape of stress condition was applied to the specimens to perform the creep-fatigue crack growth rate tests. Each specimen's surface was polished and fatigue pre-crack was manufactured by fatigue test before the high temperature test. And DCPD method was adopted to measure the crack length in the high temperature

  17. Evaluation of near-surface temperature, humidity, and equivalent temperature from regional climate models applied in type II downscaling

    Science.gov (United States)

    Pryor, S. C.; Schoof, J. T.

    2016-04-01

    Atmosphere-surface interactions are important components of local and regional climates due to their key roles in dictating the surface energy balance and partitioning of energy transfer between sensible and latent heat. The degree to which regional climate models (RCMs) represent these processes with veracity is incompletely characterized, as is their ability to capture the drivers of, and magnitude of, equivalent temperature (Te). This leads to uncertainty in the simulation of near-surface temperature and humidity regimes and the extreme heat events of relevance to human health, in both the contemporary and possible future climate states. Reanalysis-nested RCM simulations are evaluated to determine the degree to which they represent the probability distributions of temperature (T), dew point temperature (Td), specific humidity (q) and Te over the central U.S., the conditional probabilities of Td|T, and the coupling of T, q, and Te to soil moisture and meridional moisture advection within the boundary layer (adv(Te)). Output from all RCMs exhibits discrepancies relative to observationally derived time series of near-surface T, q, Td, and Te, and use of a single layer for soil moisture by one of the RCMs does not appear to substantially degrade the simulations of near-surface T and q relative to RCMs that employ a four-layer soil model. Output from MM5I exhibits highest fidelity for the majority of skill metrics applied herein, and importantly most realistically simulates both the coupling of T and Td, and the expected relationships of boundary layer adv(Te) and soil moisture with near-surface T and q.

  18. Machine vision algorithms applied to dynamic traffic light control

    Directory of Open Access Journals (Sweden)

    Fabio Andrés Espinosa Valcárcel

    2013-01-01

    número de autos presentes en imágenes capturadas por un conjunto de cámaras estratégicamente ubicadas en cada intersección. Usando esta información, el sistema selecciona la secuencia de acciones que optimicen el flujo vehicular dentro de la zona de control, en un escenario simulado. Los resultados obtenidos muestran que el sistema disminuye en un 20% los tiempos de retraso para cada vehículo y que además es capaz de adaptarse rápida y eficientemente a los cambios de flujo.

  19. PID Controller Parameters Tuning Based-on Satisfaction for Superheated Steam Temperature of Power Station Boiler

    Directory of Open Access Journals (Sweden)

    Benxian Xiao

    2014-06-01

    Full Text Available Proposed the PID controller parameters tuning method based-on New Luus-Jaakola (NLJ algorithm and satisfaction idea. According to the different requirements of each performance index, designed the satisfaction function with fuzzy constraint attributes, and then determined the comprehensive satisfaction function for PID tuning by NLJ algorithm. Provided the steps of PID controller parameters tuning based on the NLJ algorithm and satisfaction, and applied this tuning method to the cascade control system of superheated steam temperature for Power Station Boiler. Finally the simulation and experiment results have shown the proposed method has good dynamic and static control performances for this complicated superheated steam temperature control system.

  20. Applying Space Technology to Enhance Control of an Artificial Arm

    Science.gov (United States)

    Atkins, Diane; Donovan, William H.; Novy, Mara; Abramczyk, Robert

    1997-01-01

    At the present time, myoelectric prostheses perform only one function of the hand: open and close with the thumb, index and middle finger coming together to grasp various shaped objects. To better understand the limitations of the current single-function prostheses and the needs of the individuals who use them, The Institute for Rehabilitation and Research (TIRR), sponsored by the National Institutes of Health (August 1992 - November 1994), surveyed approximately 2500 individuals with upper limb loss. When asked to identify specific features of their current electric prosthesis that needed improvement, the survey respondents overwhelmingly identified the lack of wrist and finger movement as well as poor control capability. Simply building a mechanism with individual finger and wrist motion is not enough. Individuals with upper limb loss tend to reject prostheses that require continuous visual monitoring and concentration to control. Robotics researchers at NASA's Johnson Space Center (JSC) and Rice University have made substantial progress in myoelectric teleoperation. A myoelectric teleoperation system translates signals generated by an able-bodied robot operator's muscles during hand motions into commands that drive a robot's hand through identical motions. Farry's early work in myoelectric teleoperation used variations over time in the myoelectric spectrum as inputs to neural networks to discriminate grasp types and thumb motions. The resulting schemes yielded up to 93% correct classification on thumb motions. More recently, Fernandez achieved 100% correct non-realtime classification of thumb abduction, extension, and flexion on the same myoelectric data. Fernandez used genetic programming to develop functions that discriminate between thumb motions using myoelectric signal parameters. Genetic programming (GP) is an evolutionary programming method where the computer can modify the discriminating functions' form to improve its performance, not just adjust

  1. Research on analysis method for temperature control information of high arch dam construction

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Temperature control,which is directly responsible for the project quality and progress,plays an important role in high arch dam construction.How to discover the rules from a large amount of temperature control information collected in order to guide the adjustment of temperature control measures to prevent cracks on site is the key scientific problem.In this paper,a mathematic logical model was built firstly by means of a coupling analysis of temperature control system decomposition and coordination for high arch dam.Then,an analysis method for temperature control information was presented based on data mining technology.Furthermore,the data warehouse of temperature control was designed,and the artificial neural network forecasting model for the highest temperature of concrete was also developed.Finally,these methods were applied to a practical project. The result showed that the efficiency and precision of temperature control was improved,and rationality and scientificity of management and decision-making were strengthened.All of these researches provided an advanced analysis method for temperature control in the high arch dam construction process.

  2. Electrostatic Control over Temperature-Dependent Tunneling across a Single Molecule Junction

    OpenAIRE

    Alvar R. Garrigues; Wang, Lejia; del Barco, Enrique; Nijhuis, Christian A.

    2016-01-01

    Understanding how the mechanism of charge transport through molecular tunnel junctions depends on temperature is crucial to control electronic function in molecular electronic devices. With just a few systems investigated as a function of bias and temperature so far, thermal effects in molecular tunnel junctions remain poorly understood. Here we report a detailed charge transport study of an individual redox-active ferrocene-based molecule over a wide range of temperatures and applied potenti...

  3. Controllability of brushite structural parameters using an applied magnetic field.

    Science.gov (United States)

    Kuznetsov, V N; Yanovska, A A; Stanislavov, A S; Danilchenko, S N; Kalinkevich, A N; Sukhodub, L F

    2016-03-01

    The paper studies the influence of low intensity static magnetic field on brushite structural and microstructural parameters using the X-ray diffraction and the transmission electron microscopy. This effect was shown to have various influences on DCPD (Dicalcium Phosphate Dihydrate) structure depending on a magnetic field configuration or time of synthesis, which allows achieving controllability of the main properties of an obtained material. The influence of the magnetic field leads mostly to the decrease of crystallite sizes with no impact on the crystal lattice parameters. In (0 2 0) and (1 5 0) planes the growth of crystallite sizes is observed after 2 and 3 days of crystallization, respectively. The analysis of different contributions to peak broadening in [0 b 0] direction showed a similar trend for the crystallite sizes with the lower lattice microstrains after 2 days of synthesis. The effect similar to the preferred orientation was observed and classified with the Harris method. PMID:26706562

  4. Feasibility of Applying Controllable Lubrication Techniques to Reciprocating Machines

    DEFF Research Database (Denmark)

    Pulido, Edgar Estupinan

    The use of active lubrication in journal bearings helps to enhance the thin fluid films by increasing the fluid film thickness and consequently reducing viscous friction losses and vibrations. One refers to active lubrication when conventional hydrodynamic lubrication is combined with dynamically...... conventional lubrication conditions, a mathematical model of a reciprocating mechanism connected to a rigid / flexible rotor via thin fluid films was developed. The mathematical model involves the use of multibody dynamics theory for the modelling of the reciprocating mechanism (rigid bodies), finite elements...... method for the modelling of the flexible rotor (crankshaft) and hydrodynamic fluid film theory for describing the dynamics of the thin fluid films. When active lubrication is introduced to modify conventional hydrodynamic lubrication, by means of aplying radial oil injection at controllable oil pressures...

  5. Feasibility of Applying Controllable Lubrication to Dynamically Loaded Journal Bearings

    DEFF Research Database (Denmark)

    Estupinan, Edgar Alberto; Santos, Ilmar

    2009-01-01

    fluid films, based on fluid film theory. For a dynamically loaded journal bearing, the fluid film pressure distribution can be computed by numerically solving the Reynolds equation, by means of finite-difference method. Particularly, in this study the main focus is on the lubrication behavior of the...... reaction forces in a reciprocating compressor have a cyclic behavior, periodic oil pressure injection rules based on the instantaneous crank angle and load bearing condition can be established. In this paper, several bearing configurations working under different oil pressure injection rules conditions are...... analyzed. The behavior of the following parameters is investigated when the system operates with hybrid controllable lubrication conditions: a) maximum fluid film pressure, b) minimum fluid film thickness, c) maximum vibration levels and d) injection oil pressures....

  6. SOFC temperature evaluation based on an adaptive fuzzy controller

    Institute of Scientific and Technical Information of China (English)

    Xiao-juan WU; Xin-jian ZHU; Guang-yi CAO; Heng-yong TU

    2008-01-01

    The operating temperature of a solid oxide fuel cell (SOFC) stack is a very important parameter to be controlled, which impacts the performance of the SOFC due to thermal cycling. In this paper, an adaptive fuzzy control method based on an affine nonlinear temperature model is developed to control the temperature of the SOFC within a specified range. Fuzzy logic systems are used to approximate nonlinear functions in the SOFC system and an adaptive technique is employed to construct the controller. Compared with the traditional fuzzy and proportion-integral-derivative (PID) control, the simulation results show that the designed adaptive fuzzy control method performed much better. So it is feasible to build an adaptive fuzzy controller for temperature control of the SOFC.

  7. Requirements control system applied to collider dipole magnet development

    International Nuclear Information System (INIS)

    A number of Myths abound in the area of requirements development. The Requirements Control System (RCS) developed and used by General Dynamics on the CDM contract aims to dispel these myths and ensure comprehensive requirements flowdown to elements of the Collider Dipole Magnet (CDM) and the supporting Analysis, Demonstration, Quality Assurance and Master Test Plans. RCS also provides requirements traceability information by providing the source for each requirement, whether it be from a higher level specification, or from a supporting analysis or trade study. The computer is put to work doing what it does best, keeping track of details and checking for consistency and completeness. The myths that the use of RCS attempts to drive away are: I have to design it first so I can determine what the requirements are; I don't have time to write down the requirements; I'm too busy designing; I know what the requirements are; I don't see why I should write them down; If I have to wait for requirements, I'll never get done; The requirements are changing, so why document them until they are finalized? For the CDM program, the source requirements documents are the SSCL 15 Metre CDM Magnet System Specification and the SSCL CDM Interface Control Document. RCS has been used to generate: CDM Prime Item Development Specification; CDM Prime Item Product Fabrication Specification; Prime Item Product Function Specifications [Cold Mass, Cryostat, and Interconnect Region]; Critical Item Specifications [Beam Tube Assembly, and Superconducting Inner and Outer Cables]. Requirements have been further developed for major subassemblies such as the Cold Mass Support Post and other major items of tooling, test equipment, and transportation equipment. The use of RCS has enabled us to accomplish more work in a shorter time than conventional methods would allow

  8. PIXE and PDMS techniques applied to environmental control

    International Nuclear Information System (INIS)

    The airborne particles containing metals are the one of main sources of workers and environmental exposure during mineral mining and milling processes. In order to evaluate the risk of the workers and to the environment due to mineral processes, it is necessary to determine, the concentration and the kinetics of the particles. Furthermore, the chemical composition, particle size and the elemental mass concentration in the fine fraction of aerosol are necessary for evaluation of the risk. Mineral sands are processed to obtain rutile (TiO2), ilmenite (TiFeO3), zircon (ZrSiO4 and monazite (RE3(PO4)) concentrates. The aim of this work was to apply PIXE (Particle Induced X ray Emission) and PDMS (Plasma Desorption Mass Spectrometry) methods to characterize mineral dust particles generated at this plant. The mass spectrum of positive ions of cerium oxide shows that the cerium is associated to oxygen (CeOn). Compounds of thorium (ThO2) and (ThSiO4), Sr, Ca, Zr were also observed in this spectrum. The positive ions mass spectrum of the concentrate of monazite shows that Th was associated to oxygen (ThOn) and Ce was associated to (POn). Also shows compounds of other rare earth as La, Nd and Y. Ions of ZrSiO3, TiO2 and TiFeO3 present in the mass spectra indicate that the concentrate of monazite contains zircon, rutile and ilmenite. Compounds of Cl, Ca, Mn, V, Cu, Zn and Pb also were identified in the mass spectrum. This study shows that PIXE and PDMS techniques can be used as complementary methods for the aerosol analysis. (author)

  9. MULTI-OBJECTIVE PID CONTROLLER BASED ON ADAPTIVE WEIGHTED PSO WITH APPLICATION TO STEAM TEMPERATURE CONTROL IN BOILERS

    OpenAIRE

    C Agees Kumar; N.Kesavan Nair

    2010-01-01

    PID controller is widely used for main steam temperature control of boiler unit in thermal power plant. To avoid the drawback of current PID design methods, this paper presents a new design method for multi-objective PID controller to synthetically consider system requirement in reliability and robustness. Adaptive weighted PSO (AWPSO) technique is applied to the parameter optimization design. The optimization problem considered is highly nonlinear, complex, with multiple objectives and const...

  10. Experimental research on pulse forming based on high-temperature SMES applied in pulsed power

    Science.gov (United States)

    Zhou, Yusheng; Kuang, Jianghua; Tang, Yuejin; Song, Meng; Wei, Bin; Cheng, Shijie; Pan, Yuan

    2009-03-01

    To research the key problems of storage energy and pulse forming in pulsed power, a pulse magnet made of Bi2223/Ag high-temperature superconducting (HTS) tapes applied in pulsed power experiment was developed. After determining electromagnetic characteristics of the magnet, a pulse forming network was designed. HTS magnet was immersed in liquid nitrogen bath, experiments were carried out about discharging pulse current to resistance load based on HTS magnet energy storage (SMES). The results show that pulse current waves were obtained through adjusted circuit construction and magnet parameters by acting delay of switches in the pulse forming network. The technical schemes about pulse forming based on SMES were presented.

  11. Controlling the temperature in Canadian homes

    International Nuclear Information System (INIS)

    Programmable thermostats can be used to optimize the operation of heating and cooling systems by reducing system usage when occupants are asleep or when dwellings are unoccupied. This paper used the results of a 2006 households and the environment survey to examine how programmable thermostats are currently being used in Canadian households. The demographic factors associated with thermostat use were discussed, as well as how their usage varied in different areas of Canada. The study showed that most Canadian households set their temperature at between 20 to 22 degrees C during times when they are home and awake. Home temperatures were reduced to between 16 and 18 degrees C when household members were away or asleep. Only 4 out of 10 households used programmable thermostats. Of those who used programmable thermostats, only 7 in 10 programmed the thermostat to lower the temperature when occupants were asleep. Senior citizens and people with lower levels of education were less likely to use programmable thermostats. It was concluded that incentive programs and the distribution of free programmable thermostats will increase their use in households. Assistance in programming during the installation process should also be provided. Factor analyses must also be conducted to examine the influence of age, education, and income and the decisions made by households in relation to temperature regulation. 7 tabs

  12. Controlling the temperature in Canadian homes

    Energy Technology Data Exchange (ETDEWEB)

    Dewis, G.

    2008-09-15

    Programmable thermostats can be used to optimize the operation of heating and cooling systems by reducing system usage when occupants are asleep or when dwellings are unoccupied. This paper used the results of a 2006 households and the environment survey to examine how programmable thermostats are currently being used in Canadian households. The demographic factors associated with thermostat use were discussed, as well as how their usage varied in different areas of Canada. The study showed that most Canadian households set their temperature at between 20 to 22 degrees C during times when they are home and awake. Home temperatures were reduced to between 16 and 18 degrees C when household members were away or asleep. Only 4 out of 10 households used programmable thermostats. Of those who used programmable thermostats, only 7 in 10 programmed the thermostat to lower the temperature when occupants were asleep. Senior citizens and people with lower levels of education were less likely to use programmable thermostats. It was concluded that incentive programs and the distribution of free programmable thermostats will increase their use in households. Assistance in programming during the installation process should also be provided. Factor analyses must also be conducted to examine the influence of age, education, and income and the decisions made by households in relation to temperature regulation. 7 tabs.

  13. Water temperature controls in low arctic rivers

    Science.gov (United States)

    King, Tyler V.; Neilson, Bethany T.; Overbeck, Levi D.; Kane, Douglas L.

    2016-06-01

    Understanding the dynamics of heat transfer mechanisms is critical for forecasting the effects of climate change on arctic river temperatures. Climate influences on arctic river temperatures can be particularly important due to corresponding effects on nutrient dynamics and ecological responses. It was hypothesized that the same heat and mass fluxes affect arctic and temperate rivers, but that relative importance and variability over time and space differ. Through data collection and application of a river temperature model that accounts for the primary heat fluxes relevant in temperate climates, heat fluxes were estimated for a large arctic basin over wide ranges of hydrologic conditions. Heat flux influences similar to temperate systems included dominant shortwave radiation, shifts from positive to negative sensible heat flux with distance downstream, and greater influences of lateral inflows in the headwater region. Heat fluxes that differed from many temperate systems included consistently negative net longwave radiation and small average latent heat fluxes. Radiative heat fluxes comprised 88% of total absolute heat flux while all other heat fluxes contributed less than 5% on average. Periodic significance was seen for lateral inflows (up to 26%) and latent heat flux (up to 18%) in the lower and higher stream order portions of the watershed, respectively. Evenly distributed lateral inflows from large scale flow differencing and temperatures from representative tributaries provided a data efficient method for estimating the associated heat loads. Poor model performance under low flows demonstrated need for further testing and data collection to support the inclusion of additional heat fluxes.

  14. Control of flowering by ambient temperature.

    Science.gov (United States)

    Capovilla, Giovanna; Schmid, Markus; Posé, David

    2015-01-01

    The timing of flowering is a crucial decision in the life cycle of plants since favourable conditions are needed to maximize reproductive success and, hence, the survival of the species. It is therefore not surprising that plants constantly monitor endogenous and environmental signals, such as day length (photoperiod) and temperature, to adjust the timing of the floral transition. Temperature in particular has been shown to have a tremendous effect on the timing of flowering: the effect of prolonged periods of cold, called the vernalization response, has been extensively studied and the underlying epigenetic mechanisms are reasonably well understood in Arabidopsis thaliana. In contrast, the effect of moderate changes in ambient growth temperature on the progression of flowering, the thermosensory pathway, is only starting to be understood on the molecular level. Several genes and molecular mechanisms underlying the thermosensory pathway have already been identified and characterized in detail. At a time when global temperature is rising due to climate change, this knowledge will be pivotal to ensure crop production in the future. PMID:25326628

  15. Return temperature control and heat exchanger configurations

    Energy Technology Data Exchange (ETDEWEB)

    Koot, M.H.M.

    1995-07-17

    MESA is a district heating company, supplying heat and domestic hot water to family houses and buildings in Almere, Netherlands, in a number of ways. MESA has been confronted with high return temperatures of the domestic water returning from the city to the combined heat and power generating plant (CHP) through the primary network. The temperature is higher than anticipated in the design and leads to higher operating costs of the CHP plant. In this report the causes of the high return temperatures are identified and measures to reduce them are presented. The primary return temperature at the sub-station of a collective domestic water system can be reduced from 53.7 deg C to 48.9 deg C under the design conditions or from 56.7 deg C to 24.4 deg C in summer conditions. This can be accomplished by proper adjustment of the heating curve, insertion of thermostatic bypasses and by reconfiguring the heat exchangers in the substation. The flow rates would decrease by 7% to 55%. 33 figs., 5 tabs., 8 refs.

  16. Multivariable control theory applied to hierarchial attitude control for planetary spacecraft

    Science.gov (United States)

    Boland, J. S., III; Russell, D. W.

    1972-01-01

    Multivariable control theory is applied to the design of a hierarchial attitude control system for the CARD space vehicle. The system selected uses reaction control jets (RCJ) and control moment gyros (CMG). The RCJ system uses linear signal mixing and a no-fire region similar to that used on the Skylab program; the y-axis and z-axis systems which are coupled use a sum and difference feedback scheme. The CMG system uses the optimum steering law and the same feedback signals as the RCJ system. When both systems are active the design is such that the torques from each system are never in opposition. A state-space analysis was made of the CMG system to determine the general structure of the input matrices (steering law) and feedback matrices that will decouple the axes. It is shown that the optimum steering law and proportional-plus-rate feedback are special cases. A derivation of the disturbing torques on the space vehicle due to the motion of the on-board television camera is presented. A procedure for computing an upper bound on these torques (given the system parameters) is included.

  17. MULTI-OBJECTIVE PID CONTROLLER BASED ON ADAPTIVE WEIGHTED PSO WITH APPLICATION TO STEAM TEMPERATURE CONTROL IN BOILERS

    Directory of Open Access Journals (Sweden)

    C.Agees Kumar

    2010-07-01

    Full Text Available PID controller is widely used for main steam temperature control of boiler unit in thermal power plant. To avoid the drawback of current PID design methods, this paper presents a new design method for multi-objective PID controller to synthetically consider system requirement in reliability and robustness. Adaptive weighted PSO (AWPSO technique is applied to the parameter optimization design. The optimization problem considered is highly nonlinear, complex, with multiple objectives and constraints. The simulation results on an actual main steam temperature control system indicate that, the multi-objective PID controller designed by presented method, can improve the dynamic performance of main steam temperature control system, with good robustness ability.

  18. Temperature-controlling system for high power LEDs based on semiconductor coolers

    Directory of Open Access Journals (Sweden)

    Changguang LI

    2015-06-01

    Full Text Available Semiconductor refrigeration was used for heat dissipation of high power LEDs. A practical temperature-controlling system was designed and built with a microcontroller unit (STC89C52 and a thermoelectric cooling module (TEC1-12703 as the core components. Functions including temperature measurement, display, setup, and control were realized. PWM (pulse width modulation was applied to regulate the driving current of the thermoelectric cooler. Effective refrigeration and temperature control were thus achieved. This system was used for the temperature control of a LED module with the power of 7×3 W. When the environment temperature was 22~25 ℃, the substrate temperature of the LED module could be stabilized in the range of 40~70 ℃. If the upper and lower temperature limits of the LED substrate were set to be 64 ℃and 65 ℃, respectively, the power consumed by thermoelectric cooling was only 27% of that consumed by the LEDs. The temperature-controlling system had a high cooling speed (up to 14 ℃/min and small temperature fluctuation (only ±0.5 ℃. It fulfilled the requirements for LED temperature control and could be used for many other applications.

  19. Diffusing wave spectroscopy applied to material analysis and process control

    International Nuclear Information System (INIS)

    Diffusing Wave Spectroscopy (DWS) was studied as a method of laboratory analysis of sub-micron particles, and developed as a prospective in-line, industrial, process control sensor, capable of near real-time feedback. No sample pre-treatment was required and measurement was via a non-invasive, flexible, dip in probe. DWS relies on the concept of the diffusive migration of light, as opposed to the ballistic scatter model used in conventional dynamic light scattering. The specific requirements of the optoelectronic hardware, data analysis methods and light scattering model were studied experimentally and, where practical, theoretically resulting in a novel technique of analysis of particle suspensions and emulsions of volume fractions between 0.01 and 0.4. Operation at high concentrations made the technique oblivious to dust and contamination. A pure homodyne (autodyne) experimental arrangement described was resilient to environmental disturbances, unlike many other systems which utilise optical fibres or heterodyne operation. Pilot and subsequent prototype development led to a highly accurate method of size ranking, suitable for analysis of a wide range of suspensions and emulsions. The technique was shown to operate on real industrial samples with statistical variance as low as 0.3% with minimal software processing. Whilst the application studied was the analysis of TiO2 suspensions, a diverse range of materials including polystyrene beads, cell pastes and industrial cutting fluid emulsions were tested. Results suggest that, whilst all sizing should be comparative to suitable standards, concentration effects may be minimised and even completely modelled-out in many applications. Adhesion to the optical probe was initially a significant problem but was minimised after the evaluation and use of suitable non stick coating materials. Unexpected behaviour in the correlation in the region of short decay times led to consideration of the effects of rotational diffusion

  20. Control rod drive for high temperature gas cooled reactor

    Institute of Scientific and Technical Information of China (English)

    DengJun-Xian; XuJi-Ming; 等

    1998-01-01

    This control rod drive is developed for HTR-10 high temperature gas cooled test reactor.The stepmotor is prefered to improve positioning of the control rod and the scram behavior.The preliminary test in 1600170 ambient temperature shows that the selected stepmotor and transmission system can meet the main operation function requirements of HTR-10.

  1. 14 CFR 25.1157 - Carburetor air temperature controls.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Carburetor air temperature controls. 25.1157 Section 25.1157 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Accessories § 25.1157 Carburetor air temperature controls. There must be a separate carburetor air...

  2. 14 CFR 29.1157 - Carburetor air temperature controls.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Carburetor air temperature controls. 29.1157 Section 29.1157 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Accessories § 29.1157 Carburetor air temperature controls. There must be a separate carburetor air...

  3. Fundamental Study on Saving Energy for Electrified Railway System Applying High Temperature Superconductor Motor and Energy Storage System

    Science.gov (United States)

    Konishi, Takeshi; Nakamura, Taketsune; Amemiya, Naoyuki

    Induction motor instead of dc one has been applied widely for dc electric rolling stock because of the advantage of its utility and efficiency. However, further improvement of motor characteristics will be required to realize environment-friendly dc railway system in the future. It is important to study more efficient machine applying dc electric rolling stock for next generation high performance system. On the other hand, the methods to reuse regenerative energy produced by motors effectively are also important. Therefore, we carried out fundamental study on saving energy for electrified railway system. For the first step, we introduced the energy storage system applying electric double-layer capacitors (EDLC), and its control system. And then, we tried to obtain the specification of high temperature superconductor induction/synchronous motor (HTS-ISM), which performance is similar with that of the conventional induction motors. Furthermore, we tried to evaluate an electrified railway system applying energy storage system and HTS-ISM based on simulation. We succeeded in showing the effectiveness of the introductions of energy storage system and HTS-ISM in DC electrified railway system.

  4. Study of fieldbus technology confiability when applied in a Sterilization plant control and safety systems

    International Nuclear Information System (INIS)

    Several sterilization processes have been used in these years for treatment of countless products. Some processes use high temperatures, thermal shocks and chemical agents. With the discovery of the ionizing radiation and its posterior technological developments turned possible the application of that process, in 1960, also in the sterilization, denominated radiation sterilization. This process became also applied in another areas of health and industrial as food conservation, gemstones enhancement and others. The radiation sterilization requests an effective control and it needs a high level of safety. The commercial use of the computers applied in industrial automation provides and the domain of new technologies in this field provides news applications then new designs now is possible. The Fieldbus technology, a new digital communication protocol, like a Local Area Network, can be an alternative in the cobalt-60 irradiation plant. This paper show preliminary study about confiability in systems using Fieldbus technology. This technology was simulated in sterilization plant control and safety systems and the fail probability was quantified using Fail Tree Analysis Method. Fieldbus technology can be used in sterilization plants because the confiability in this systems is like PLCs and relays systems, was the conclusion

  5. Design of linear controllers applied to an ethanol steam reformer for PEM fuel cell applications

    OpenAIRE

    García, Vanesa M.; Serra, Maria; Llorca, Jordi; Riera, Jordi

    2013-01-01

    This paper focuses on the design of a controller for a low temperature ethanol steam reformer for the production of hydrogen to feed a protonic exchange membrane (PEM) fuel cell. It describes different control structures for the reformer and treats the control structure selection of this multiple input multiple output (MIMO) system. For each considered control structure, decentralised 2 × 2 controllers with proportional integral (PI) control actions in each control loop are implemented. The t...

  6. Hypothalamic and dietary control of temperature-mediated longevity

    OpenAIRE

    Tabarean, Iustin; Morrison, Brad; Marcondes, Maria Cecilia; Bartfai, Tamas; Conti, Bruno

    2009-01-01

    Temperature is an important modulator of longevity and aging in both poikilotherms and homeotherm animals. In homeotherms, temperature homeostasis is regulated primarily in the preoptic area (POA) of the hypothalamus. This region receives and integrates peripheral, central and environmental signals and maintains a nearly constant core body temperature (Tcore) by regulating the autonomic and hormonal control of heat production and heat dissipation. Temperature sensitive neurons found in the PO...

  7. Definition study for temperature control in advanced protein crystal growth

    Science.gov (United States)

    Nyce, Thomas A.; Rosenberger, Franz; Sowers, Jennifer W.; Monaco, Lisa A.

    1990-01-01

    Some of the technical requirements for an expedient application of temperature control to advanced protein crystal growth activities are defined. Lysozome was used to study the effects of temperature ramping and temperature gradients for nucleation/dissolution and consecutive growth of sizable crystals and, to determine a prototype temperature program. The solubility study was conducted using equine serum albumin (ESA) which is an extremely stable, clinically important protein due to its capability to bind and transport many different small ions and molecules.

  8. Temperature Control of Evaporative Cooler (EC for Converter Dry Dedusting

    Directory of Open Access Journals (Sweden)

    Li Fangwei

    2013-09-01

    Full Text Available The converter dry dedusting is more complicated with higher requirements in automatic control than the wet dust extraction. The key difficult point is the EC temperature control. This paper puts forth a method to effectively deal with the fluctuated-drastically temperature caused by control lagging at the EC outlet in the traditional converter dry dedusting. The EC outlet temperature can be under control of technological requirement by combining controls of proportion, empirical value, fuzziness and PID. The intelligent system is available with parameter auto tuning, which facilitates the on-site debugging greatly for operators. The result of the on-site application suggests that this method can be used to well handle some technological difficulties in the EC temperature control.    

  9. TEMPERATURE DISTRIBUTION MONITORING AND ANALYSES AT DIFFERENT HEATING CONTROL PRINCIPLES

    DEFF Research Database (Denmark)

    Simone, Angela; Rode, Carsten; Olesen, Bjarne W.

    2010-01-01

    control sensor which was already installed. The room was heated by means of electrical radiators, which should be able to control the indoor environment to guarantee the desired thermal conditions for the occupants and to supply heat according to desired load patterns. Five series of experiments were done...... comfort conditions for the building occupants. During the winter and spring of 2009 a study based on analyses of the local temperatures distribution in a room was performed. The purpose was to compare the temperature distribution in the room with the temperature measured and logged by the heating system...... when temperature control strategy THERM was used. Notable vertical temperature gradients were monitored in the occupied zone (especially for the PRBS control strategy) when there were high solar gains....

  10. Modeling, Prediction, and Control of Heating Temperature for Tube Billet

    Directory of Open Access Journals (Sweden)

    Yachun Mao

    2015-01-01

    Full Text Available Annular furnaces have multivariate, nonlinear, large time lag, and cross coupling characteristics. The prediction and control of the exit temperature of a tube billet are important but difficult. We establish a prediction model for the final temperature of a tube billet through OS-ELM-DRPLS method. We address the complex production characteristics, integrate the advantages of PLS and ELM algorithms in establishing linear and nonlinear models, and consider model update and data lag. Based on the proposed model, we design a prediction control algorithm for tube billet temperature. The algorithm is validated using the practical production data of Baosteel Co., Ltd. Results show that the model achieves the precision required in industrial applications. The temperature of the tube billet can be controlled within the required temperature range through compensation control method.

  11. AUTOMATIC CONTROL SYSTEM OF THE DRUM BOILER SUPERHEATED STEAM TEMPERATURE.

    OpenAIRE

    Juravliov A.A.; Sit M.L.; Poponova O.B.; Sit B.B.; Zubatii A.L.

    2006-01-01

    The control system of the temperature of the superheated steam of the drum boiler is examined. Main features of the system are the PI-controller in the external control loop and introduction of the functional component of the error signal of the external control loop with the negative feedback of the error signal between the prescribed value of steam flowrate and the signal of the steam flowrate in the exit of the boiler in the internal control loop.

  12. AUTOMATIC CONTROL SYSTEM OF THE DRUM BOILER SUPERHEATED STEAM TEMPERATURE.

    Directory of Open Access Journals (Sweden)

    Juravliov A.A.

    2006-04-01

    Full Text Available The control system of the temperature of the superheated steam of the drum boiler is examined. Main features of the system are the PI-controller in the external control loop and introduction of the functional component of the error signal of the external control loop with the negative feedback of the error signal between the prescribed value of steam flowrate and the signal of the steam flowrate in the exit of the boiler in the internal control loop.

  13. Application study of complex control algorithm for regenerative furnace temperature

    Institute of Scientific and Technical Information of China (English)

    Lusheng GE

    2004-01-01

    Altemative switch combustion mode of air and gas is adopted on the two sides of the regenerative furnace, its temperature is in uncontrolled state in the switching process and the switch period is generally 3 ~ 5 min. Thus, the conventional bi-cross limited combustion control method is no longer applicable to the object. This paper makes use of neutral network algorithm to adjust the static operating point. On this basis, fuzzy control strategy is used for the furnace temperature control. The actual application result shows that the control strategy is effective to solve the problem of the combustion control for regenerative furnace.

  14. Energy consumption and control response evaluations of AODV routing in WSANs for building-temperature control.

    Science.gov (United States)

    Booranawong, Apidet; Teerapabkajorndet, Wiklom; Limsakul, Chusak

    2013-01-01

    The main objective of this paper is to investigate the effects of routing protocols on wireless sensor and actuator networks (WSANs), focusing on the control system response and the energy consumption of nodes in a network. We demonstrate that routing algorithms designed without considering the relationship between communication and control cannot be appropriately used in wireless networked control applications. For this purpose, an ad-hoc on-demand distance vector (AODV) routing, an IEEE 802.15.4, and a building-temperature control system are employed for this exploration. The findings from our scenarios show that the AODV routing can select a path with a high traffic load for data transmission. It takes a long time before deciding to change a new route although it experiences the unsuccessful transmission of packets. As a result, the desirable control target cannot be achieved in time, and nodes consume more energy due to frequent packet collisions and retransmissions. Consequently, we propose a simple routing solution to alleviate these research problems by modifying the original AODV routing protocol. The delay-threshold is considered to avoid any congested connection during routing procedures. The simulation results demonstrate that our solution can be appropriately applied in WSANs. Both the energy consumption and the control system response are improved. PMID:23807689

  15. Biot Critical Frequency Applied as Common Friction Factor for Chalk with Different Pore Fluids and Temperatures

    DEFF Research Database (Denmark)

    Andreassen, Katrine Alling; Fabricius, Ida Lykke

    Injection of water into chalk hydrocarbon reservoirs has lead to mechanical yield and failure. Laboratory experiments on chalk samples correspondingly show that the mechanical properties of porous chalk depend on pore fluid and temperature. Water has a significant softening effect on elastic...... we propose that the fluid effect on mechanical properties of highly porous chalk may be the result of liquid‐solid friction. Applying a different strain or stress rate is influencing the rock strength and needs to be included. The resulting function is shown to relate to the material dependent and...... rate independent b-factor used when describing the time dependent mechanical properties of soft rock or soils. As a consequence it is then possible to further characterize the material constant from the porosity and permeability of the rock as well as from pore fluid density and viscosity which is...

  16. Static and Dynamical Properties of Antiferromagnetic Skyrmions in the Presence of Applied Current and Temperature

    Science.gov (United States)

    Barker, Joseph; Tretiakov, Oleg A.

    2016-04-01

    Skyrmions are topologically protected entities in magnetic materials which have the potential to be used in spintronics for information storage and processing. However, Skyrmions in ferromagnets have some intrinsic difficulties which must be overcome to use them for spintronic applications, such as the inability to move straight along current. We show that Skyrmions can also be stabilized and manipulated in antiferromagnetic materials. An antiferromagnetic Skyrmion is a compound topological object with a similar but of opposite sign spin texture on each sublattice, which, e.g., results in a complete cancellation of the Magnus force. We find that the composite nature of antiferromagnetic Skyrmions gives rise to different dynamical behavior due to both an applied current and temperature effects.

  17. Fuzzy Based Control Using Lab view For Temperature Process

    Directory of Open Access Journals (Sweden)

    S.Kavitha, B.Chinthamani, S.Joshibha Ponmalar

    2012-12-01

    Full Text Available This project aims at designing and implementing afuzzy controller for Multiple Input Single Outputtemperature process. Temperature control of waterin the tank is achieved by varying current to theheating rod and inlet flow rate by a fuzzy controller.The system consists of a tank, reservoir, variablespeed pump, temperature sensor placed inside aheating tank containing the heating rod, voltagecontrolled current source and computer. Water ispumped into the tank from reservoir and RTDmeasures the current temperature. The signal fromthe temperature sensor is sent to the DAQ interfacedto the computer. LabVIEW software is used toacquire the input signal and send the output signalthat is determined by the control algorithm. Fuzzylogic controller is designed in LabVIEW. Based onthe set point temperature, the controller sets theappropriate current to the heating rod. If therequired temperature is less than that sensed by thetemperature sensor, the flow rate of water into thetank is controlled by a variable speed pump. Whileconventional controllers are analytically describedby a set of equations, the FLC is described by aknowledge-based algorithm. Thus this system ishighly efficient in both heating and reducing thetemperature of the tank. A fuzzy logic controllergives faster response, is more reliable and recoversquickly from system upsets. It also works well touncertainties in the process variables and it does notrequire mathematical modelling.

  18. Influence of the Applied Potential and Temperature on the Electrodeposition of the Lead Dioxide

    Directory of Open Access Journals (Sweden)

    Taha Yaseen Khalaf

    2013-06-01

    Full Text Available The excellent specifications of electrodes coated with lead dioxide material make it of great importance in the industry. So it was suggested this study, which includes electrodeposition of lead dioxide on graphite substrate, knowing that the electrodeposition of lead dioxide on graphite studied earlier in different ways. In this work the deposition process for lead dioxide conducted using electrolytic solution containing lead nitrate concentration 0.72 M with the addition of some other material to the solution, such as copper nitrate, nickel nitrate, sodium fluoride and cetyl trimethyl ammonium bromide, but only in very small concentrations. As for the operating conditions, the effect of change potential and temperature as well as the time on the deposition process was studied. The results shown at the end of the experiments that the change in the applied potential to the cell and electrolytic solution temperature had the greatest influence on the cell current, anodic current density, anodic overpotential and the amount of lead dioxide deposited on the anode.

  19. Design and Implementation of Motor Speed control and Temperature sensing unit using PIC Controller

    OpenAIRE

    Ms. Ei Ei Thaw; Zaw Min Min Htun

    2014-01-01

    This paper aims to design and implementation of DC motor speed, temperature sensing of material. This project is mainly concerned on DC motor speed control system by using microcontroller PIC 16F877A. Motor speed can be control with variable resistor. So, this programming device can be used any motor to control their speed. Temperature sensing device display the temperature of any place. At the heart of the circuit is the LM35 and microcontroller which controls all ...

  20. A Comparative Study on Temperature Control of CSTR using PI Controller, PID Controller and PID (Two Degree of Freedom Controller

    Directory of Open Access Journals (Sweden)

    Bikash Dey

    2014-01-01

    Full Text Available This paper present three different control strategies based on PI Control, PID control and Two degree of freedom PID control for Continuous Stirred Tank Reactor (CSTR.CSTR which offers a diverse range of application in the field of chemical engineering as well as in the control engineering and is an attractive research area for process control researchers. Our objective is to control the temperature of CSTR in presence of the set point. MATLAB SIMULINK software is used for model design and simulation

  1. Robust control of speed and temperature in a power plant gas turbine.

    Science.gov (United States)

    Najimi, Ebrahim; Ramezani, Mohammad Hossein

    2012-03-01

    In this paper, an H(∞) robust controller has been designed for an identified model of MONTAZER GHAEM power plant gas turbine (GE9001E). In design phase, a linear model (ARX model) which is obtained using real data has been applied. Since the turbine has been used in a combined cycle power plant, its speed and also the exhaust gas temperature should be adjusted simultaneously by controlling fuel signals and compressor inlet guide vane (IGV) position. Considering the limitations on the system inputs, the aim of the control is to maintain the turbine speed and the exhaust gas temperature within desired interval under uncertainties and load demand disturbances. Simulation results of applying the proposed robust controller on the nonlinear model of the system (NARX model), fairly fulfilled the predefined aims. Simulations also show the improvement in the performance compared to MPC and PID controllers for the same conditions. PMID:22062324

  2. Synchronous temperature rate control for refrigeration with reduced energy consumption

    Science.gov (United States)

    Gomes, Alberto Regio; Keres, Stephen L.; Kuehl, Steven J.; Litch, Andrew D.; Richmond, Peter J.; Wu, Guolian

    2015-09-22

    Methods of operation for refrigerator appliance configurations with a controller, a condenser, at least one evaporator, a compressor, and two refrigeration compartments. The configuration may be equipped with a variable-speed or variable-capacity compressor, variable speed evaporator or compartment fans, a damper, and/or a dual-temperature evaporator with a valve system to control flow of refrigerant through one or more pressure reduction devices. The methods may include synchronizing alternating cycles of cooling each compartment to a temperature approximately equal to the compartment set point temperature by operation of the compressor, fans, damper and/or valve system. The methods may also include controlling the cooling rate in one or both compartments. Refrigeration compartment cooling may begin at an interval before or after when the freezer compartment reaches its lower threshold temperature. Freezer compartment cooling may begin at an interval before or after when the freezer compartment reaches its upper threshold temperature.

  3. Weld Nugget Temperature Control in Thermal Stir Welding

    Science.gov (United States)

    Ding, R. Jeffrey (Inventor)

    2014-01-01

    A control system for a thermal stir welding system is provided. The control system includes a sensor and a controller. The sensor is coupled to the welding system's containment plate assembly and generates signals indicative of temperature of a region adjacent and parallel to the welding system's stir rod. The controller is coupled to the sensor and generates at least one control signal using the sensor signals indicative of temperature. The controller is also coupled to the welding system such that at least one of rotational speed of the stir rod, heat supplied by the welding system's induction heater, and feed speed of the welding system's weld material feeder are controlled based on the control signal(s).

  4. Central control of body temperature [version 1; referees: 3 approved

    Directory of Open Access Journals (Sweden)

    Shaun F. Morrison

    2016-05-01

    Full Text Available Central neural circuits orchestrate the behavioral and autonomic repertoire that maintains body temperature during environmental temperature challenges and alters body temperature during the inflammatory response and behavioral states and in response to declining energy homeostasis. This review summarizes the central nervous system circuit mechanisms controlling the principal thermoeffectors for body temperature regulation: cutaneous vasoconstriction regulating heat loss and shivering and brown adipose tissue for thermogenesis. The activation of these thermoeffectors is regulated by parallel but distinct efferent pathways within the central nervous system that share a common peripheral thermal sensory input. The model for the neural circuit mechanism underlying central thermoregulatory control provides a useful platform for further understanding of the functional organization of central thermoregulation, for elucidating the hypothalamic circuitry and neurotransmitters involved in body temperature regulation, and for the discovery of novel therapeutic approaches to modulating body temperature and energy homeostasis.

  5. A fuzzy-split range control system applied to a fermentation process.

    Science.gov (United States)

    Fonseca, Rodolpho Rodrigues; Schmitz, Jones Erni; Fileti, Ana Maria Frattini; da Silva, Flavio Vasconcelos

    2013-08-01

    In this study it was proposed the application of a fuzzy-PI controller in tandem with a split range control strategy to regulate the temperature inside a fermentation vat. Simulations were carried out using different configurations of fuzzy controllers and split range combinations for regulatory control. The performance of these control systems were compared using conventional integral of error criteria, the demand of utilities and the control effort. The proposed control system proved able to adequately regulate the temperature in all the tests. Besides, considering a similar ITAE index and using the energetically most efficient split range configuration, fuzzy-PI controller provided a reduction of approximately 84.5% in the control effort and of 6.75% in total demand of utilities by comparison to a conventional PI controller. PMID:23759431

  6. Output torque and temperature control technologies for an electrical screw press motor

    Institute of Scientific and Technical Information of China (English)

    LI Jun-chao; HUANG Shu-huai; FENG Yi

    2008-01-01

    The DSC (direct self control) of speed regulation technology was applied to drive a motor running at a certain overloading ratio in intermittent working conditions. To control motor temperatures rising effectively, a finite element method with an iterative approach was applied to simulate real working conditions and analyze the temperature rising of the inner part of the motor. Application of DSC speed regulation realizes the invariable torque output quickly and avoids the peak current at the start state in favor of the motor temperature decreasing. Based on an analysis with the finite limit method, some effective measures were taken to improve the ability of the motor to expel heat. The overload ability of the motor was improved and the stable motor temperature rising was obtained, fulfilling the demands of electrical screw presses.

  7. Fiber Fabry-Perot interferometer with controllable temperature sensitivity.

    Science.gov (United States)

    Zhang, Xinpu; Peng, Wei; Zhang, Yang

    2015-12-01

    We proposed a fiber taper based on the Fabry-Perot (FP) interferometer structure with controllable temperature sensitivity. The FP interferometer is formed by inserting a segment of tapered fiber tip into the capillary and subsequently splicing the other end of the capillary to a single-mode fiber (SMF), the tapered fiber endface, and the spliced face form the FP cavity. Through controlling the inserted tapered fiber length, a series of FP interferometers were made. Because the inserted taper tip has the degree of freedom along the fiber axial, when the FP interferometer is subjected to temperature variation, the thermal expansion of the fiber taper tip will resist the FP cavity length change caused by the evolution of capillary length, and we can control the temperature sensitivity by adjusting the inserted taper length. In this structure, the equivalent thermal expansion coefficient of the FP interferometer can be defined; it was used to evaluate the temperature sensitivity of the FP interferometer, which provides an effective method to eliminate the temperature effect and to enhance other measurement accuracy. We fabricated the FP interferometers and calibrated their temperature characters by measuring the wavelength shift of the resonance dips in the reflection spectrum. In a temperature range of 50°C to 150°C, the corresponding temperature sensitivities can be controlled between 0 and 1.97 pm/°C when the inserted taper is between 75 and 160 μm. Because of its controllable temperature sensitivity, ease of fabrication, and low cost, this FP interferometer can meet different temperature sensitivity requirements in various application areas, especially in the fields which need temperature insensitivity. PMID:26625075

  8. [Temperature measuring and heating controlling in transurethral prostate thermotherapy system].

    Science.gov (United States)

    Luo, L; Wang, Q; Chen, Y; Yu, X

    1997-07-01

    This paper introduces the system construction of Transurethral Prostate Thermotherapy Device. The temperature measuring device, I/O interface circuit and the programming principle of PID controlling system is illustrated also. PMID:11189255

  9. Nonlinear Predictive Control for PEMFC Stack Operation Temperature

    Institute of Scientific and Technical Information of China (English)

    LI Xi; CAO Guang-yi; ZHU Xin-jian

    2005-01-01

    Operating temperature of proton exchange membrane fuel cell stack should be controlled within a special range. The input-output data and operating experiences were used to establish a PEMFC stack model and operating temperature control system. A nonlinear predictive control algorithm based on fuzzy model was presented for a family of complex system with severe nonlinearity such as PEMFC. Based on the obtained fuzzy model, a discrete optimization of the control action was carried out according to the principle of Branch and Bound method. The test results demonstrate the effectiveness and advantage of this approach.

  10. Supply temperature control concepts in heat pump heating systems

    OpenAIRE

    Huchtemann, Kristian

    2015-01-01

    In recent years, electrically driven compression heat pumps have come to be widely used for the heating of buildings. Their efficiency strongly depends on the temperature lift which is influenced by the supply temperature of the heat sink. When used with radiator heating systems it is challenging to operate heat pumps efficiently because high supply temperatures are required. Therefore, in order to efficiently operate heat pumps, this work analyses advanced control concepts for heatpump heati...

  11. Composite Control of Precalciner Exit Temperature in Cement Rotary Kiln

    Institute of Scientific and Technical Information of China (English)

    赵晨; 诸静

    2003-01-01

    A composite control strategy for the precalciner exit temperature in cement kiln is introduced based on a mathematical model. In this model, the raw meal flow, coal powder flow and wind flow are taken as three input variables, the clinker fow and exit teperature of cement kiln are output variables, and other influencing factors are considered as disturbance. A composite control system is synthesied by integrating self-learning PID, fuzzy and feedforward function into a combined controller, and the arithmetics for the self-learning PID controller, fuzzy controller and feedforward controller are elaborated respectively. The control strategy has been realized by software in real practice at cement factory. Application results show that the composite control technology is superior to the general PID control in control effect, and is suitable to the industrial process control with slow parameter variation, nonlinearity and uncertainty.

  12. Northwestern Pacific typhoon intensity controlled by changes in ocean temperatures

    OpenAIRE

    Mei, Wei; Xie, Shang-Ping; Primeau, François; Mcwilliams, James C.; Pasquero, Claudia

    2015-01-01

    Dominant climatic factors controlling the lifetime peak intensity of typhoons are determined from six decades of Pacific typhoon data. We find that upper ocean temperatures in the low-latitude northwestern Pacific (LLNWP) and sea surface temperatures in the central equatorial Pacific control the seasonal average lifetime peak intensity by setting the rate and duration of typhoon intensification, respectively. An anomalously strong LLNWP upper ocean warming has favored increased intensificatio...

  13. Improving arachidonic acid fermentation by Mortierella alpina through multistage temperature and aeration rate control in bioreactor.

    Science.gov (United States)

    Gao, Min-Jie; Wang, Cheng; Zheng, Zhi-Yong; Zhu, Li; Zhan, Xiao-Bei; Lin, Chi-Chung

    2016-05-18

    Effective production of arachidonic acid (ARA) using Mortierella alpina was conducted in a 30-L airlift bioreactor. Varying the aeration rate and temperature significantly influenced cell morphology, cell growth, and ARA production, while the optimal aeration rate and temperature for cell growth and product formation were quite different. As a result, a two-stage aeration rate control strategy was constructed based on monitoring of cell morphology and ARA production under various aeration rate control levels (0.6-1.8 vvm). Using this strategy, ARA yield reached 4.7 g/L, an increase of 38.2% compared with the control (constant aeration rate control at 1.0 vvm). Dynamic temperature-control strategy was implemented based on the fermentation performance at various temperatures (13-28°C), with ARA level in total cellular lipid increased by 37.1% comparing to a constant-temperature control (25°C). On that basis, the combinatorial fermentation strategy of two-stage aeration rate control and dynamic temperature control was applied and ARA production achieved the highest level of 5.8 g/L. PMID:26038800

  14. Comparison of transition temperature criteria applied for KLST and ISO-V type Charpy specimens

    International Nuclear Information System (INIS)

    A great deal of test data have been obtained on reactor pressure vessel steels using the standard Charpy-V test. Although more advanced test methods, based on elastic-plastic fracture mechanics, are both recommendable and already in use in the surveillance programmes of some nuclear power plants (NPPs), Charpy tests are still required, e.g., by regulatory guides. Besides the normal-size (ISO-V) Charpy specimen (10 x10 x 55 mm3), various types of sub-size specimens have been introduced. One standardised sub-size specimen being in use is the so-called KLST specimen, the size of which is 3 x 4 x 27 mm3 with 1 mm central notch (DIN50 115). So far the test data published for the KLST specimen, as well as sub-size specimens in general, is still limited. The results from small specimen testing are typically used for evaluating the fracture behaviour of the ISO-V Charpy specimen and if there are no test results available for the correlation, as there usually is not, a general correlation has to be applied to evaluate the fracture behaviour of the ISO-V specimen. The availability of a sub-size specimen depends therefore significantly on how reliably this relationship has been established. Impact test data measured with different specimens have been correlated using some appropriate criterion (or criteria) and since a total transition curve is normally measured, there are several ones available. The criterion can be a fixed energy or lateral expansion level describing the transition temperature or the level can be derived from the upper-shelf energy (USE). In general, the proposed criterion can be divided into two groups: those derived from the dimensions of the specimens and those derived empirically from experimental data. Test data measured with ISO-V and KLST-type Charpy specimens are discussed and the validity of two proposed, basically different transition temperature criteria and the resulting differences in the temperatures, that are inevitable because of the

  15. Hybrid model predictive control applied to switching control of burner load for a compact marine boiler design

    DEFF Research Database (Denmark)

    Solberg, Brian; Andersen, Palle; Maciejowski, Jan;

    2008-01-01

    This paper discusses the application of hybrid model predictive control to control switching between different burner modes in a novel compact marine boiler design. A further purpose of the present work is to point out problems with finite horizon model predictive control applied to systems for w...

  16. Analysis, Modelling, and Simulation of Droop Control with Virtual Impedance Loop Applied to Parallel UPS Systems

    DEFF Research Database (Denmark)

    Lima, Francisco Kleber A.; Branco, Carlos Gustavo C.; Guerrero, Josep M.;

    2013-01-01

    This paper explores a control strategy for parallel uninterruptible power systems (UPS). The control technique used in that work was based on the droop control method. This method is usually applied to achieve good active and reactive power sharing when communication between the inverters is diff...

  17. 40 CFR 1060.103 - What permeation emission control requirements apply for fuel tanks?

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false What permeation emission control requirements apply for fuel tanks? 1060.103 Section 1060.103 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EVAPORATIVE EMISSIONS FROM NEW AND IN-USE NONROAD AND STATIONARY EQUIPMENT...

  18. 40 CFR 1060.102 - What permeation emission control requirements apply for fuel lines?

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false What permeation emission control requirements apply for fuel lines? 1060.102 Section 1060.102 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EVAPORATIVE EMISSIONS FROM NEW AND IN-USE NONROAD AND STATIONARY EQUIPMENT...

  19. 40 CFR 1060.104 - What running loss emission control requirements apply?

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false What running loss emission control requirements apply? 1060.104 Section 1060.104 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EVAPORATIVE EMISSIONS FROM NEW AND IN-USE NONROAD AND STATIONARY EQUIPMENT Emission Standards...

  20. Plug and Play Process Control Applied to a District Heating System

    DEFF Research Database (Denmark)

    Knudsen, Torben; Trangbæk, Klaus; Kallesøe, Carsten Skovmose

    2008-01-01

    The general ideas within plug and play process control (PTC) are to initialize and reconfigure control systems just by plug and play. In this paper these ideas are applied to a district heating pressure control problem. First of all this serves as a concrete example of PTC, secondly some of the f...

  1. Equivalent electrical network model approach applied to a double acting low temperature differential Stirling engine

    International Nuclear Information System (INIS)

    Highlights: • An equivalent electrical network modeling of Stirling engine is proposed. • This model is applied to a membrane low temperate double acting Stirling engine. • The operating conditions (self-startup and steady state behavior) are defined. • An experimental engine is presented and tested. • The model is validated against experimental results. - Abstract: This work presents a network model to simulate the periodic behavior of a double acting free piston type Stirling engine. Each component of the engine is considered independently and its equivalent electrical circuit derived. When assembled in a global electrical network, a global model of the engine is established. Its steady behavior can be obtained by the analysis of the transfer function for one phase from the piston to the expansion chamber. It is then possible to simulate the dynamic (steady state stroke and operation frequency) as well as the thermodynamic performances (output power and efficiency) for given mean pressure, heat source and heat sink temperatures. The motion amplitude especially can be determined by the spring-mass properties of the moving parts and the main nonlinear effects which are taken into account in the model. The thermodynamic features of the model have then been validated using the classical isothermal Schmidt analysis for a given stroke. A three-phase low temperature differential double acting free membrane architecture has been built and tested. The experimental results are compared with the model and a satisfactory agreement is obtained. The stroke and operating frequency are predicted with less than 2% error whereas the output power discrepancy is of about 30%. Finally, some optimization routes are suggested to improve the design and maximize the performances aiming at waste heat recovery applications

  2. Enhanced Temperature Control Method Using ANFIS with FPGA

    Directory of Open Access Journals (Sweden)

    Chiung-Wei Huang

    2014-01-01

    Full Text Available Temperature control in etching process is important for semiconductor manufacturing technology. However, pressure variations in vacuum chamber results in a change in temperature, worsening the accuracy of the temperature of the wafer and the speed and quality of the etching process. This work develops an adaptive network-based fuzzy inference system (ANFIS using a field-programmable gate array (FPGA to improve the effectiveness. The proposed method adjusts every membership function to keep the temperature in the chamber stable. The improvement of the proposed algorithm is confirmed using a medium vacuum (MV inductively-coupled plasma- (ICP- type etcher.

  3. Enhanced temperature control method using ANFIS with FPGA.

    Science.gov (United States)

    Huang, Chiung-Wei; Pan, Shing-Tai; Zhou, Jun-Tin; Chang, Cheng-Yuan

    2014-01-01

    Temperature control in etching process is important for semiconductor manufacturing technology. However, pressure variations in vacuum chamber results in a change in temperature, worsening the accuracy of the temperature of the wafer and the speed and quality of the etching process. This work develops an adaptive network-based fuzzy inference system (ANFIS) using a field-programmable gate array (FPGA) to improve the effectiveness. The proposed method adjusts every membership function to keep the temperature in the chamber stable. The improvement of the proposed algorithm is confirmed using a medium vacuum (MV) inductively-coupled plasma- (ICP-) type etcher. PMID:24715808

  4. FUZZY CONTROLLER AND NEURAL ESTIMATOR APPLIED TO CONTROL A SYSTEM POWERED BY THREE-PHASE INDUCTION MOTOR

    OpenAIRE

    Élida Fernanda Xavier Júlio; Simplício Arnaud da Silva; Cícero da Rocha Souto

    2015-01-01

    In this study, a control strategy is presented to control the position and the feed rate of a table of a milling machine powered by three-phase induction motor, when machining pieces constituted by different types of materials: steel, brass and nylon. For development of the control strategy, the vector control technique was applied to drive the three-phase induction machines. The estimation of the electromagnetic torque of the motor was used to determine the machining feed rate fo...

  5. Ion Temperature Control of the Io Plasma Torus

    Science.gov (United States)

    Delamere, P. A.; Schneider, N. M.; Steffl, A. J.; Robbins, S. J.

    2005-01-01

    We report on observational and theoretical studies of ion temperature in the Io plasma torus. Ion temperature is a critical factor for two reasons. First, ions are a major supplier of energy to the torus electrons which power the intense EUV emissions. Second, ion temperature determines the vertical extent of plasma along field lines. Higher temperatures spread plasma out, lowers the density and slows reaction rates. The combined effects can play a controlling role in torus energetics and chemistry. An unexpected tool for the study of ion temperature is the longitudinal structure in the plasma torus which often manifests itself as periodic brightness variations. Opposite sides of the torus (especially magnetic longitudes 20 and 200 degrees) have been observed on numerous occasions to have dramatically different brightness, density, composition, ionization state, electron temperature and ion temperature. These asymmetries must ultimately be driven by different energy flows on the opposite sides, presenting an opportunity to observe key torus processes operating under different conditions. The most comprehensive dataset for the study of longitudinal variations was obtained by the Cassini UVIS instrument during its Jupiter flyby. Steffl (Ph.D. thesis, 2005) identified longitudinal variations in all the quantities listed above wit the exception of ion temperature. We extend his work by undertaking the first search for such variation in the UVIS dataset. We also report on a 'square centimeter' model of the torus which extend the traditional 'cubic centimeter' models by including the controlling effects of ion temperature more completely.

  6. Analysis, Modelling, and Simulation of Droop Control with Virtual Impedance Loop Applied to Parallel UPS Systems

    OpenAIRE

    Lima, Francisco Kleber A.; Branco, Carlos Gustavo C.; Josep M. Guerrero; Neto, Luis Juarez C.; Carvalho, Samuel S.; Torrico-Bascope, Rene P.

    2013-01-01

    This paper explores a control strategy for parallel uninterruptible power systems (UPS). The control technique used in that work was based on the droop control method. This method is usually applied to achieve good active and reactive power sharing when communication between the inverters is difficult due to its physical location. This paper has considered that the UPS systems there were no comunication between their controls. A detailed mathematical model about the explored system is shown i...

  7. An X-ray camera for single-crystal studies at high temperatures under controlled atmosphere

    International Nuclear Information System (INIS)

    A vacuum heating camera has been developed for extremely low background X-ray film work between room temperature and 2000 K. It can be used with modified conventional Weissenberg goniometers and with a specially designed focusing goniometer. The temperature control is maintained by a Pt/Pt-10% Rh thermocouple, a three-term proportional, integral and derivative (PID) controller and a programmable power supply. The accuracy in the absolute temperature setting is 10 K, the stability better than 1 K and the maximum thermal gradient over the crystal 7 K mm-1 at 1330 K. A small oxygen pressure can be applied, depending on the temperature, to control oxidation or reduction reactions of the sample. (Auth.)

  8. Effect of applied DC voltages and temperatures on space charge behaviour of multi-layer oil-paper insulation

    International Nuclear Information System (INIS)

    In this paper, space charge in a multi-layer oil-paper insulation system was investigated using the pulsed electroacoustic (PEA) technique. A series of measurements had been carried following subjection of the insulation system to different applied voltages and different temperatures. Charge behaviours in the insulation system were analyzed and the influence of temperature on charge dynamics was discussed. The test results shows that homocharge injection takes place under all the test conditions, the applied DC voltage mainly affects the amount of space charge, while the temperature has greater influence on the distribution and mobility of space charge inside oil-paper samples.

  9. DSC: software tool for simulation-based design of control strategies applied to wastewater treatment plants.

    Science.gov (United States)

    Ruano, M V; Ribes, J; Seco, A; Ferrer, J

    2011-01-01

    This paper presents a computer tool called DSC (Simulation based Controllers Design) that enables an easy design of control systems and strategies applied to wastewater treatment plants. Although the control systems are developed and evaluated by simulation, this tool aims to facilitate the direct implementation of the designed control system to the PC of the full-scale WWTP (wastewater treatment plants). The designed control system can be programmed in a dedicated control application and can be connected to either the simulation software or the SCADA of the plant. To this end, the developed DSC incorporates an OPC server (OLE for process control) which facilitates an open-standard communication protocol for different industrial process applications. The potential capabilities of the DSC tool are illustrated through the example of a full-scale application. An aeration control system applied to a nutrient removing WWTP was designed, tuned and evaluated with the DSC tool before its implementation in the full scale plant. The control parameters obtained by simulation were suitable for the full scale plant with only few modifications to improve the control performance. With the DSC tool, the control systems performance can be easily evaluated by simulation. Once developed and tuned by simulation, the control systems can be directly applied to the full-scale WWTP. PMID:21330730

  10. Nonlinear Superheat and Evaporation Temperature Control of a Refrigeration Plant

    DEFF Research Database (Denmark)

    Rasmussen, Henrik; Thybo, Claus; Larsen, Lars F. S.

    2006-01-01

    This paper proposes novel control of the superheat of the evaporator in a refrigeration system. A new model of the evaporator is developed and based on this model the superheat is transferred to a referred variable. It is shown that control of this variable leads to a linear system independent of...... the working point. The model also gives a method for control of the evaporation temperature. The proposed method is validated by experimental results....

  11. Neuro-fuzzy generalized predictive control of boiler steam temperature

    OpenAIRE

    Chan, CW; Liu, XJ

    2006-01-01

    Reliable control of superheated steam temperature is necessary to ensure high efficiency and high load-following capability in the operation of modern power plant. This is often difficult to achieve using conventional PI controllers, as power plants are nonlinear and contain many uncertainties. A nonlinear generalized predictive controller based on neuro-fuzzy network (NFGPC) is proposed in this paper, which consists of local GPCs designed using the local linear models of the neuro-fuzzy netw...

  12. A decentralized Fuzzy Logic enhanced variable structure controller applied to load frequency control system

    International Nuclear Information System (INIS)

    This paper present a variable structure based approach to the load frequency control system problem in electric power generation systems. This approach combines the salient features of both variable structure and Fuzzy systems to achieve high-performance and robustness. The control signal consists of equivalent control, switching control and Fuzzy control components. The influence of system nonlinearities such as generation rate constraint and governor dead band is considered. In results show that the system responses are strongly robust for parameter variations

  13. Some consideration regarding the political control of constitutionality as a primary applied form of control (France)

    OpenAIRE

    DANIELA CRISTINA VALEA

    2007-01-01

    France is the state where the political control of constitutionality has found its full consecration, where the opposition to the jurisdictional control of constitutionality was so strong that, when the political control failed, transfer was made directly to the political-jurisdictional control of constitutionality. This paper has attempted to provide an overview of the historical evolution of the control of constitutionality, which was present in the French constitutional system only under i...

  14. Phasic temperature control appraised with the Ceres-Wheat model.

    Science.gov (United States)

    Volk, T; Bugbee, B; Tubiello, F

    1997-01-01

    Phasic control refers to the specification of a series of different environmental conditions during a crop's life cycle, with the goal of optimizing some aspect of productivity. Because of the enormous number of possible scenarios, phasic control is an ideal situation for modeling to provide guidance prior to experiments. Here we use the Ceres-Wheat model, modified for hydroponic growth chambers, to examine temperature effects. We first establish a baseline by running the model at constant temperatures from 10 degrees C to 30 degrees C. Grain yield per day peaks at 15 degrees C at a value that is 25% higher than the yield at the commonly used 23 degrees C. We then show results for phasic control limited to a single shift in temperature and, finally, we examine scenarios that allow each of the five phases of the life cycle to have a different temperature. Results indicate that grain yield might be increased by 15-20% over the best yield at constant temperature, primarily from a boosted harvest index, which has the additional advantage of less waste biomass. Such gains, if achievable, would help optimize food production for life support systems. Experimental work should first verify the relationship between yield and temperature, and then move to selected scenarios of phasic control, based on model predictions. PMID:11540452

  15. Control of temperature and energy consumption in buildings - A review

    Directory of Open Access Journals (Sweden)

    D.W.U. Perera, C. F. Pfeiffer, N.-O Skeie

    2014-01-01

    Full Text Available Building sector is one of the largest energy consumers in the world and currently it utilizes 40% of the total energy in the European Union. At the beginning of the article, energy crisis related to the buildings is defined with regard to occupant thermal comfort, energy savings and temperature control. Subsequently, a brief presentation of various types of building heating models available for control purposes is given. Afterward, different approaches used for controlling the building thermal comfort and the energy consumption are shown. These strategies are primarily, classical control, advanced control, intelligent control and hybrid control. The proposed survey also provides up-to-date applications of control techniques. The overview hence affords an insight into current control systems used for temperature and energy consumption in buildings. Further, it helps to have a comprehensive understanding about the variety of control techniques in the field of HVAC (Heating, Ventilation and Air conditioning applications, at the same time delivering information for careful design of suitable controllers.

  16. Electrostatic control over temperature-dependent tunnelling across a single-molecule junction

    Science.gov (United States)

    Garrigues, Alvar R.; Wang, Lejia; Del Barco, Enrique; Nijhuis, Christian A.

    2016-05-01

    Understanding how the mechanism of charge transport through molecular tunnel junctions depends on temperature is crucial to control electronic function in molecular electronic devices. With just a few systems investigated as a function of bias and temperature so far, thermal effects in molecular tunnel junctions remain poorly understood. Here we report a detailed charge transport study of an individual redox-active ferrocene-based molecule over a wide range of temperatures and applied potentials. The results show the temperature dependence of the current to vary strongly as a function of the gate voltage. Specifically, the current across the molecule exponentially increases in the Coulomb blockade regime and decreases at the charge degeneracy points, while remaining temperature-independent at resonance. Our observations can be well accounted for by a formal single-level tunnelling model where the temperature dependence relies on the thermal broadening of the Fermi distributions of the electrons in the leads.

  17. Experimental design applied to the optimization of pyrolysis and atomization temperatures for As measurement in water samples by GFAAS

    Science.gov (United States)

    Ávila, Akie K.; Araujo, Thiago O.; Couto, Paulo R. G.; Borges, Renata M. H.

    2005-10-01

    In general, research experimentation is often used mainly when new methodologies are being developed or existing ones are being improved. The characteristics of any method depend on its factors or components. The planning techniques and analysis of experiments are basically used to improve the analytical conditions of methods, to reduce experimental labour with the minimum of tests and to optimize the use of resources (reagents, time of analysis, availability of the equipment, operator time, etc). These techniques are applied by the identification of variables (control factors) of a process that have the most influence on the response of the parameters of interest, by attributing values to the influential variables of the process in order that the variability of response can be minimum, or the obtained value (quality parameter) be very close to the nominal value, and by attributing values to the influential variables of the process so that the effects of uncontrollable variables can be reduced. In this central composite design (CCD), four permanent modifiers (Pd, Ir, W and Rh) and one combined permanent modifier W+Ir were studied. The study selected two factors: pyrolysis and atomization temperatures at five different levels for all the possible combinations. The pyrolysis temperatures with different permanent modifiers varied from 600 °C to 1600 °C with hold times of 25 s, while atomization temperatures ranged between 1900 °C and 2280 °C. The characteristic masses for As were in the range of 31 pg to 81 pg. Assuming the best conditions obtained on CCD, it was possible to estimate the measurement uncertainty of As determination in water samples. The results showed that considering the main uncertainty sources such as the repetitivity of measurement inherent in the equipment, the calibration curve which evaluates the adjustment of the mathematical model to the results and the calibration standards concentrations, the values obtained were similar to international

  18. A Robust Practical Generalized Predictive Control for BoilerSuper Heater Temperature Control

    Directory of Open Access Journals (Sweden)

    Zaki Maki Mohialdeen

    2015-06-01

    Full Text Available A practical method of robust generalized predictive controller (GPC application is developed using a combination of Ziegler-Nichols type functions relating the GPC controller parameters to a first order with time delay process parameters and a model matching controller. The GPC controller and the model matching controller are used in a master/slave configuration, with the GPC as the master controller and the model matching controller as the slave controller. The model matching controller parameters are selected to obtain the desired overall performance. The effectiveness of the proposed control method is tested by simulation using a mathematical model of the boiler super heater temperature process.

  19. Case Study of Various Parameters by Applying Swing Up Control for Inverted Pendulum

    OpenAIRE

    Kunal Chakraborty; Amit Kumar Sen; Rahul Dev Basak; Rahul Raushan

    2015-01-01

    This paper investigates behavior of the system in terms of time response e.g., steady state error, rise time & overshoot & then compare it with FLC. Being an unstable system, Inverted Pendulum is very common control problem being assigned to control its dynamics. It is almost impossible to balance a pendulum in the inverted position except applying some force from outside to the system.

  20. AFC applied to HVDC interconnected systems and multivariable control. Chokuryu renkeiyo AFC to tahensu seigyo

    Energy Technology Data Exchange (ETDEWEB)

    Hatano, M. (Electric Power Development Co. Ltd., Tokyo (Japan)); Tsumenaga, M. (Toshiba Corp., Tokyo (Japan))

    1993-06-20

    Together with a growth of the power demand as well as becoming to be a higher degree and diversification of the social function, the power system has been getting more and more complicated. By the digital technology, which has remarkably developed in recent years, in addition, the control theory in a high level, which had been hard to be handled by the conventional technology, has become possible to be applied for the control devices, also in the control system of the power system. In this paper, an example applied the multivariable control, the modern control theory has been utilized, for the automatic frequency control(AFC) of the HVDC interconnected systems, which connect two power systems, is introduced. In order to verify the control performance of AFC applied the multivariable control, in addition, the AFC device is manufactured, and then the simulation is performed by combining it with the power system simulator simulated two AC systems and one DC interconnected system. When the multivariable controlled AFC is compared with the conventional AFC as for the frequency fluctuation, it is clearly found that the control performance of the former is better than the latter. 2 refs., 5 figs., 1 tab.

  1. Improved controlled atmosphere high temperature scanning probe microscope

    OpenAIRE

    Hansen, Karin Vels; Wu, Yuehua; Jacobsen, Torben; Mogensen, Mogens Bjerg; Kuhn, Luise Theil

    2013-01-01

    To locally access electrochemical active surfaces and interfaces in operando at the sub-micron scale at high temperatures in a reactive gas atmosphere is of great importance to understand the basic mechanisms in new functional materials, for instance, for energy technologies, such as solid oxide fuel cells and electrolyzer cells. Here, we report on advanced improvements of our original controlled atmosphere high temperature scanning probe microscope, CAHT-SPM. The new microscope can employ a ...

  2. Monitoring and Control of Temperature in Networks-on-Chip

    OpenAIRE

    Wegner, Tim; Cornelius, Claas; Tockhorn, Andreas; Timmermann, Dirk

    2011-01-01

    Increasing integration densities and the emergence of nanotechnology cause issues related to reliability and power consumption to become dominant factors for the design of modern multi-core systems. Since the arising problems are enforced by high circuit temperatures, monitoring and control of on-chip temperature profiles need to be considered during design phase as well as during system operation. Hence, in this paper different approaches for the realization and integration of a monitoring s...

  3. The Use Of Multifrequency Induction Heating For Temperature Distribution Control

    OpenAIRE

    Smalcerz A.

    2015-01-01

    The paper presents possibilities of controlling temperature field distribution in inductively heated charge. The change of its distribution was obtained using the sequential one-, two-, and three-frequency heating. The study was conducted as a multi-variant computer simulation of hard coupled electromagnetic and temperature fields. For the analysis, a professional calculation software package utilizing the finite element method, Flux 3D, was used. The problem of obtaining an appropriate tempe...

  4. Manual-control Analysis Applied to the Money-supply Control Task

    Science.gov (United States)

    Wingrove, R. C.

    1984-01-01

    The recent procedure implemented by the Federal Reserve Board to control the money supply is formulated in the form of a tracking model as used in the study of manual-control tasks. Using this model, an analysis is made to determine the effect of monetary control on the fluctuations in economic output. The results indicate that monetary control can reduce the amplitude of fluctuations at frequencies near the region of historic business cycles. However, with significant time lags in the control loop, monetary control tends to increase the amplitude of the fluctuations at the higher frequencies. How the investigator or student can use the tools developed in the field of manual-control analysis to study the nature of economic fluctuations and to examine different strategies for stabilization is examined.

  5. Does runoff or temperature control chemical weathering rates?

    International Nuclear Information System (INIS)

    Highlights: → The rate chemical weathering is affected by both temperature and runoff. Separating out these two factors is challenging because runoff tends to increase with increasing temperature. → In this study, natural river water samples collected on basaltic catchments over a five year period are used together with experimentally derived dissolution rate model for basaltic glass to pull apart the effects of runoff and temperature. → This study shows that the rate of chemical denudation is controlled by both temperature and runoff, but is dominated by runoff. - Abstract: The rate of chemical denudation is controlled by both temperature and runoff. The relative role of these two factors in the rivers of NE Iceland is determined through the rigorous analysis of their water chemistry over a 5-a period. River catchments are taken to be analogous to laboratory flow reactors; like the fluid in flow reactors, the loss of each dissolved element in river water is the sum of that of the original rainwater plus that added from kinetically controlled dissolution and precipitation reactions. Consideration of the laboratory determined dissolution rate behaviour of basalts and measured water chemistry indicates that the maximum effect of changing temperature on chemical denudation in the NE Icelandic rivers was 5-25% of the total change, whereas that of runoff was 75-95%. The bulk of the increased denudation rates with runoff appear to stem from an increase in reactive surface area for chemical weathering of catchment solids.

  6. Design and Experiment of Slave Computer Control System for Applying Variable-rate Liquid Fertilizer

    Institute of Scientific and Technical Information of China (English)

    Zhang Ying-zi; Chen Hai-tao; Hou Shou-yin; Ji Wen-yi; Ouyang Bin-lin; Dun Guo-qiang; Zhang Ji-cheng

    2015-01-01

    In order to increase the applying rate of liquid fertilizer and reduce environmental pollution, a slave computer control system for applying variable-rate liquid fertilizer was designed. The system used SMC as core processor and electrically controlled pressure regulator as execution component. The characteristic equation of the system was obtained by using classical control theory. Results indicated that the characteristic equation met the requirements of routh-criterion, which indicated the working process of the system was stable. Performance of the slave computer was verified via bench tests. Results demonstrated that there was no significant influence on the response from interclass error. The fertilization error was less than 0.9, and the fertilization accuracy was larger than 97%. The liquid fertilizer emitted by the fertilizing devices had no significant difference in uniformity, which met the demands of the slave computer control system for applying variable-rate liquid fertilizer.

  7. Hypothalamic and dietary control of temperature-mediated longevity.

    Science.gov (United States)

    Tabarean, Iustin; Morrison, Brad; Marcondes, Maria Cecilia; Bartfai, Tamas; Conti, Bruno

    2010-01-01

    Temperature is an important modulator of longevity and aging in both poikilotherms and homeotherm animals. In homeotherms, temperature homeostasis is regulated primarily in the preoptic area (POA) of the hypothalamus. This region receives and integrates peripheral, central and environmental signals and maintains a nearly constant core body temperature (T(core)) by regulating the autonomic and hormonal control of heat production and heat dissipation. Temperature sensitive neurons found in the POA are considered key elements of the neuronal circuitry modulating these effects. Nutrient homeostasis is also a hypothalamically regulated modulator of aging as well as one of the signals that can influence T(core) in homeotherms. Investigating the mechanisms of the regulation of nutrient and temperature homeostasis in the hypothalamus is important to understanding how these two elements of energy homeostasis influence longevity and aging as well as how aging can affect hypothalamic homeostatic mechanisms. PMID:19631766

  8. The Use Of Multifrequency Induction Heating For Temperature Distribution Control

    Directory of Open Access Journals (Sweden)

    Smalcerz A.

    2015-06-01

    Full Text Available The paper presents possibilities of controlling temperature field distribution in inductively heated charge. The change of its distribution was obtained using the sequential one-, two-, and three-frequency heating. The study was conducted as a multi-variant computer simulation of hard coupled electromagnetic and temperature fields. For the analysis, a professional calculation software package utilizing the finite element method, Flux 3D, was used. The problem of obtaining an appropriate temperature distribution in the heated charge of a complex shape is very important in many practical applications. A typical example is hardening of gear wheels. For such an application, it is necessary to obtain (on the surface and at a desired depth an uniform temperature distribution on the tooth face, top land and bottom land of the gear. The obtained temperature should have proper distribution and value. Such a distribution is very difficult to achieve.

  9. [Induction of pond-cultivated Anguilla japonica gonadial development by controlling temperature in high temperature season].

    Science.gov (United States)

    Wang, Guangjun; Xie, Jun; Yu, Deguang; Zhu, Hongyo

    2005-11-01

    In this study, the pond-cultivated Anguilla japonica was induced to mature by artificially controlling temperature at 18 +/- 2 degrees C in high temperature season (from June to September), with injection of hCG and CPE. The results showed that both the male and the female eel could be induced to mature, and the artificial maturation induction rate was 73.33% and 67.77%, while under non-controlling temperature 25 approximately 32 degrees C, the maturation induction rate was 0 and 33.33%, respectively. In an ovulation induction test, the matured female eels were induced, with a spawning inducement rate of 70%, and a fertilization rate of 32%, which approached or reached the levels in low temperature season (with an average of 62.1% and 34.2%, respectively), and the zygote developed normally. At the temperature 22 and 24 degrees C, the zygote hatched to fry in about 39 h 15 min and 34 h 9 min. The experiment proved that it was possible to induce the eel to mature by controlling temperature in high temperature season, which provided some theoretical foundations for the techniques of artificially breeding eel in whole year. PMID:16471368

  10. Active Vibration Isolation Control: Comparison of Feedback and Feedforward Control Strategies Applied to Coriolis Mass-Flow Meters (I)

    OpenAIRE

    Ridder, de, J.; Hakvoort, W.B.J.; van Dijk

    2015-01-01

    In this paper we describe the design, implementation and results of multi degree of freedom (DOF) active vibration control for a Coriolis mass-flow meter (CMFM). Without vibration control, environmental vibrational disturbances results in nanometre movement of the fluid-conveying tube which causes erroneous mass-flow measurements. In order to reduce the transmissibility from external vibrations to the internal tube displacement active vibration control is applied. A comparison of a feedback c...

  11. Rapid control of mold temperature during injection molding process

    Energy Technology Data Exchange (ETDEWEB)

    Liparoti, Sara; Titomanlio, Giuseppe [Department of Industrial Engineering, University of Salerno Via Giovanni Paolo II, 132, 84084 Fisciano (Italy); Hunag, Tsang Min; Cakmak, Mukerrem [Department of Polymer Engineering, The University of Akron, Akron, OH 44325 (United States); Sorrentino, Andrea [Institute for Polymers, Composite and Biomaterials (IPCB) - CNR, P. Enrico Fermi 1, 80055 Portici (Italy)

    2015-05-22

    The control of mold surface temperature is an important factor that determines surface morphology and its dimension in thickness direction. It can also affect the frozen molecular orientation and the mold surface replicability in injection molded products. In this work, thin thermally active films were used to quickly control the mold surface temperature. In particular, an active high electrical conductivity carbon black loaded polyimide composites sandwiched between two insulating thin polymeric layers was used to condition the mold surface. By controlling the heating time, it was possible to control precisely the temporal variation of the mold temperature surface during the entire cycle. The surface heating rate was about 40°C/s and upon contact with the polymer the surface temperature decreased back to 40°C within about 5 s; the overall cycle time increased only slightly. The effect on cross section sample morphology of samples of iPP were analyzed and discussed on the basis of the recorded temperature evolution.

  12. Controlled Atmosphere High Temperature SPM for electrochemical measurements

    International Nuclear Information System (INIS)

    A new controlled atmosphere high temperature SPM has been designed and build for the purpose of performing electrochemical measurements on solid oxide fuel cell materials. The first tests show that images can be obtained at a surface temperature of 465deg. C in air with a standard AFM AC probe. The aim is to produce images at a surface temperature of 800deg. C with electrically conducting ceramic probes as working electrodes that can be positioned at desired locations at the surface for electrochemical measurements

  13. Database Security System for Applying Sophisticated Access Control via Database Firewall Server

    OpenAIRE

    Eun-Ae Cho; Chang-Joo Moon; Dae-Ha Park; Kang-Bin Yim

    2014-01-01

    Database security, privacy, access control, database firewall, data break masking Recently, information leakage incidents have occurred due to database security vulnerabilities. The administrators in the traditional database access control methods grant simple permissions to users for accessing database objects. Even though they tried to apply more strict permissions in recent database systems, it was difficult to properly adopt sophisticated access control policies to commercial databases...

  14. High Temperature Electromechanical Components for Control Rod Drive Assemblies

    Science.gov (United States)

    Gleason, Thomas E.; Lazarus, Jonathan D.; Yaspo, Robert; Cole, Allan R.; Otwell, Robert L.; Schuster, Gary B.; Jaing, Thomas J.; Meyer, Raymond A.; Shukla, Jaikaran N.; Maldonado, Jerry

    1994-07-01

    The SP-100 power system converts heat generated within a compact fast spectrum nuclear reactor directly to electricity for spacecraft applications. The reactor control system contains the only moving mechanical and electromechanical components in the entire electrical generating system. The high temperature, vacuum environment presents unique challenges for these reactor control system components. This paper describes the environmental testing of these components that has been completed and that is in progress. The specific components and assemblies include electromagnetic (EM) coils, stepper motors, EM clutches, EM brakes, ball bearings, ball screw assemblies, constant torque spring motors, gear sets, position sensors, and very high temperature sliding bearings.

  15. Electric-field control of magnetic order above room temperature

    OpenAIRE

    Cherifi, R. O.; Ivanovskaya, V.; Phillips, L. C.; Zobelli, A.; Infante, I.C.; Jacquet, E.; Garcia, V.; Fusil, S.; Briddon, P R; Guiblin, N.; Mougin, A; Unal, A.A.; Kronast, F.; S. Valencia; Dkhil, B.

    2014-01-01

    International audience Controlling magnetism by means of electric fields is a key issue for the future development of low-power spintronics1. Progress has been made in the electrical control of magnetic anisotropy2, domain structure3,4, spin polarization5,6 or critical temperatures7,8. However, the ability to turn on and o robust ferromagnetism at room temperature and above has remained elusive. Here we use ferroelectricity in BaTiO3 crystals to tune the sharp metamagnetic transition tempe...

  16. Analysis of modern optimal control theory applied to plasma position and current control in TFTR

    International Nuclear Information System (INIS)

    The strong compression TFTR discharge has been segmented into regions where linear dynamics can approximate the plasma's interaction with the OH and EF power supply systems. The dynamic equations for these regions are utilized within the linear optimal control theory framework to provide active feedback gains to control the plasma position and current. Methods are developed to analyze and quantitatively evaluate the quality of control in a nonlinear, more realistic simulation. Tests are made of optimal control theory's assumptions and requirements, and the feasibility of this method for TFTR is assessed

  17. Remote control of magnetostriction-based nanocontacts at room temperature

    OpenAIRE

    S. Narayana Jammalamadaka; Sebastian Kuntz; Oliver Berg; Wolfram Kittler; U. Mohanan Kannan; Arout Chelvane, J.; Christoph Sürgers

    2015-01-01

    The remote control of the electrical conductance through nanosized junctions at room temperature will play an important role in future nano-electromechanical systems and electronic devices. This can be achieved by exploiting the magnetostriction effects of ferromagnetic materials. Here we report on the electrical conductance of magnetic nanocontacts obtained from wires of the giant magnetostrictive compound Tb 0.3 Dy 0.7 Fe 1.95 as an active element in a mechanically controlled break-junction...

  18. Spatial temperature control with a 27 MHZ current source interstitial hyperthermia system

    International Nuclear Information System (INIS)

    Purpose: This article gives an overview of the properties of a 27 MHz current source interstitial hyperthermia system, affecting temperature uniformity. Methods and Materials: Applicators can be inserted in standard flexible afterloading catheters. Maximum temperatures are measured with seven-point constantan-manganin thermocouple probes inside each applicator. Temperature can be controlled automatically using a simple control algorithm. Three-dimensional power absorption and thermal models for inhomogeneous tissues are available to optimize applicator geometry and phase configuration. Properties of the interstitial heating system have been verified both in phantom experiments and in in vivo treatments of rhabdomyosarcomas implanted in the flank of a rat. Results: An experiment with four electrodes in one catheter proves that longitudinal control of the specific absorption rate (SAR) is feasible. Local cooling applied by cold water circulation through a catheter perpendicular to the afterloading catheter could be compensated by independent control of electrode power. Furthermore, comparison of two different phase configurations using four dual electrode applicators shows that the SAR distribution can be manipulated significantly, utilizing the phase of the electrodes. Finally, the temperature can be controlled safely and model calculations are in fair agreement with the measurements. Conclusions: The features of the 27 MHz current source interstitial hyperthermia system enable spatial temperature control at approximately 1.5 cm

  19. High temperature corrosion kinetics by a fast X-ray diffraction method applied to nickel

    OpenAIRE

    Kolarik, V.; Juez-Lorenzo, M.; Eisenreich, N.; Engel, W.

    1993-01-01

    Temperature and time resolved X-ray diffraction was used as an in situ method, which allows the determination of kinetic data combined with the identification of the corrosion products. The performance of the method was demonstrated on the high temperature oxidation of nickel in isothermal and non-isothermal experiments. The kinetic parameters were obtained by means of the difference method. The resulting curves show the global changes as a function of time or temperature. These curves were c...

  20. A Nonlinear Multiparameters Temperature Error Modeling and Compensation of POS Applied in Airborne Remote Sensing System

    OpenAIRE

    Jianli Li; Wenjian Wang; Feng Jiao; Jiancheng Fang; Tao Yu

    2014-01-01

    The position and orientation system (POS) is a key equipment for airborne remote sensing systems, which provides high-precision position, velocity, and attitude information for various imaging payloads. Temperature error is the main source that affects the precision of POS. Traditional temperature error model is single temperature parameter linear function, which is not sufficient for the higher accuracy requirement of POS. The traditional compensation method based on neural network faces gre...

  1. ¬Mesenchymal Stem Cell Fate: Applying Biomaterials for Control of Stem Cell Behaviour

    OpenAIRE

    Hilary Jane Anderson; Matthew John Dalby; Jugal eSahoo; Rein eUljin

    2016-01-01

    Mesenchymal Stem Cell Fate: Applying Biomaterials for Control of Stem Cell BehaviourHilary J Anderson1, Jugal Kishore Sahoo2, Rein V Ulijn2,3, Matthew J Dalby1*1 Centre for Cell Engineering, University of Glasgow, Glasgow, UK.2 Technology and Innovation centre, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, UK. 3 Advanced Science Research Centre (ASRC) and Hunter College, City University of New York, NY 10031, NY, USA. Correspondence:*Hilary Andersonh.anderson...

  2. Temperature Controlled Cathode Heating in Electron Beam Welding Machine

    Czech Academy of Sciences Publication Activity Database

    Horáček, Miroslav; Dupák, Jan

    2001-01-01

    Roč. 62, 2-3 (2001), s. 165-169. ISSN 0042-207X R&D Projects: GA AV ČR IBS2065015 Institutional research plan: CEZ:AV0Z2065902 Keywords : Electron beam welding machine * cathode heating * temperature control Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 0.541, year: 2001

  3. Temperature controlled cathode heating in the electron gun

    Czech Academy of Sciences Publication Activity Database

    Horáček, Miroslav

    Brno: CSMS, 2002 - (Frank, L.), s. 69 - 70 ISBN 80-238-8749-1. [CSEM. Vranovská Ves (CZ), 08.02.2002-09.02.2002] Institutional research plan: CEZ:AV0Z2065902 Keywords : directly heated tungsten cathode * electron gun * temperature controlled cathode heating Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  4. Temperature-controlled molecular depolarization gates in nuclear magnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Schroder, Leif; Schroder, Leif; Chavez, Lana; Meldrum, Tyler; Smith, Monica; Lowery, Thomas J.; E. Wemmer, David; Pines, Alexander

    2008-02-27

    Down the drain: Cryptophane cages in combination with selective radiofrequency spin labeling can be used as molecular 'transpletor' units for transferring depletion of spin polarization from a hyperpolarized 'source' spin ensemble to a 'drain' ensemble. The flow of nuclei through the gate is adjustable by the ambient temperature, thereby enabling controlled consumption of hyperpolarization.

  5. Control of matric water potential by temperature differential

    Science.gov (United States)

    Palmer, R. J. Jr; Nienow, J. A.; Friedmann, E. I.

    1987-01-01

    A method for controlling relative humidity based on temperature differentials, rather than on salt solutions, is described. This method has the following advantages: (1) it does not exhibit the anomalous CO2 solution effects that we have found to occur with salt solutions; (2) humidity is continuously adjustable without sample removal; (3) circulation of the atmosphere results in short equilibration times.

  6. Interoperability for Space Mission Monitor and Control: Applying Technologies from Manufacturing Automation and Process Control Industries

    Science.gov (United States)

    Jones, Michael K.

    1998-01-01

    Various issues associated with interoperability for space mission monitor and control are presented in viewgraph form. Specific topics include: 1) Space Project Mission Operations Control Architecture (SuperMOCA) goals and methods for achieving them; 2) Specifics on the architecture: open standards ad layering, enhancing interoperability, and promoting commercialization; 3) An advertisement; 4) Status of the task - government/industry cooperation and architecture and technology demonstrations; and 5) Key features of messaging services and virtual devices.

  7. Biot Critical Frequency Applied as Common Friction Factor for Chalk with Different Pore Fluids and Temperatures

    DEFF Research Database (Denmark)

    Andreassen, Katrine Alling; Fabricius, Ida Lykke

    2010-01-01

    Injection of water into chalk hydrocarbon reservoirs has lead to mechanical yield and failure. Laboratory experiments on chalk samples correspondingly show that the mechanical properties of porous chalk depend on pore fluid and temperature. Water has a significant softening effect on elastic...... highly influenced by temperature....

  8. [Effects of applying controlled-release compound fertilizer on Platycodon grandiflorum growth].

    Science.gov (United States)

    Zhu, Li-xiang; Wang, Jian-hua

    2010-09-01

    A pot experiment was conducted in 2008 to study the effects of applying controlled-release compound fertilizer (N:P2O5:K2O = 14:14:14) on the growth of Platycodon grandiflorum in the medicinal herbal farm of Shandong Agricultural University. Comparing with the application of common compound fertilizer (N:P2O5: K2O=15: 15: 15), applying equivalent amount of the controlled-release fertilizer increased the leaf chlorophyll content, root volume, root activity, and root diameter of P. grandiflorum at the late growth stage, but decreased the root length. When the N application rate was 0.24 and 0.32 g x kg(-1) soil, applying the controlled-release compound fertilizer increased the root yield by 26.78% and 22.50%, and the root soluble sugar, protein, and total saponin contents by 9.77% and 6.99%, 11.38% and 2.20%, and 8.85% and 5.47%, respectively, compared with applying the common compound fertilizer. More nitrogen application made the root soluble sugar content decreased but the total saponin content increased. Under our experimental condition, applying the controlled-release compound fertilizer with an application rate of 0.24 g N x kg(-1) soil could obtain the best effect for P. grandiflorum. PMID:21265152

  9. Improved controlled atmosphere high temperature scanning probe microscope

    DEFF Research Database (Denmark)

    Hansen, Karin Vels; Wu, Yuehua; Jacobsen, Torben;

    2013-01-01

    To locally access electrochemical active surfaces and interfaces in operando at the sub-micron scale at high temperatures in a reactive gas atmosphere is of great importance to understand the basic mechanisms in new functional materials, for instance, for energy technologies, such as solid oxide...... fuel cells and electrolyzer cells. Here, we report on advanced improvements of our original controlled atmosphere high temperature scanning probe microscope, CAHT-SPM. The new microscope can employ a broad range of the scanning probe techniques including tapping mode, scanning tunneling microscopy......) is monitored by an oxygen sensor. We present here some examples of its capabilities demonstrated by high temperature topography with simultaneously ac electrical conductance measurements during atmosphere changes, electrochemical impedance spectroscopy at various temperatures, and measurements of the surface...

  10. Applied Joint-Space Torque and Stiffness Control of Tendon-Driven Fingers

    Science.gov (United States)

    Abdallah, Muhammad E.; Platt, Robert, Jr.; Wampler, Charles W.; Hargrave, Brian

    2010-01-01

    Existing tendon-driven fingers have applied force control through independent tension controllers on each tendon, i.e. in the tendon-space. The coupled kinematics of the tendons, however, cause such controllers to exhibit a transient coupling in their response. This problem can be resolved by alternatively framing the controllers in the joint-space of the manipulator. This work presents a joint-space torque control law that demonstrates both a decoupled and significantly faster response than an equivalent tendon-space formulation. The law also demonstrates greater speed and robustness than comparable PI controllers. In addition, a tension distribution algorithm is presented here to allocate forces from the joints to the tendons. It allocates the tensions so that they satisfy both an upper and lower bound, and it does so without requiring linear programming or open-ended iterations. The control law and tension distribution algorithm are implemented on the robotic hand of Robonaut-2.

  11. Control Method for Electromagnetic Unmanned Robot Applied to Automotive Test Based on Improved Smith Predictor Compensator

    Directory of Open Access Journals (Sweden)

    Gang Chen

    2015-07-01

    Full Text Available A new control method for an electromagnetic unmanned robot applied to automotive testing (URAT and based on improved Smith predictor compensator, and considering a time delay, is proposed. The mechanical system structure and the control system structure are presented. The electromagnetic URAT adopts pulse width modulation (PWM control, while the displacement and the current doubles as a closed-loop control strategy. The coordinated control method of multiple manipulators for the electromagnetic URAT, e.g., a skilled human driver with intelligent decision-making ability is provided, and the improved Smith predictor compensator controller for the electromagnetic URAT considering a time delay is designed. Experiments are conducted using a Ford FOCUS automobile. Comparisons between the PID control method and the proposed method are conducted. Experimental results show that the proposed method can achieve the accurate tracking of the target vehicle’s speed and reduce the mileage derivation of autonomous driving, which meets the requirements of national test standards.

  12. Field Test of Boiler Primary Loop Temperature Controller

    Energy Technology Data Exchange (ETDEWEB)

    Glanville, P. [Partnership for Advanced Residential Retrofit, Des Plaines, IL (United States); Rowley, P. [Partnership for Advanced Residential Retrofit, Des Plaines, IL (United States); Schroeder, D. [Partnership for Advanced Residential Retrofit, Des Plaines, IL (United States); Brand, L. [Partnership for Advanced Residential Retrofit, Des Plaines, IL (United States)

    2014-09-01

    Beyond these initial system efficiency upgrades are an emerging class of Advanced Load Monitoring (ALM) aftermarket controllers that dynamically respond to the boiler load, with claims of 10% to 30% of fuel savings over a heating season. For hydronic boilers specifically, these devices perform load monitoring, with continuous measurement of supply and, in some cases, return water temperatures. Energy savings from these ALM controllers are derived from dynamic management of the boiler differential, where a microprocessor with memory of past boiler cycles prevents the boiler from firing for a period of time, to limit cycling losses and inefficient operation during perceived low load conditions. These differ from OTR controllers, which vary boiler setpoint temperatures with ambient conditions while maintaining a fixed differential.

  13. A Study of Advanced Modern Control Techniques Applied to a Twin Rotor MIMO System

    Science.gov (United States)

    Phillips, Andrew E.

    The twin rotor MIMO system (TRMS) is a helicopter-like system that is restricted to two degrees of freedom, pitch and yaw. It is a complicated nonlinear, coupled, MIMO system used for the verification of control methods and observers. There have been many methods successfully applied to the system ranging from simple proportional integral derivative (PID) controllers, to machine learning algorithms, nonlinear control methods and other less explored methods like deadbeat control and various optimal methodologies. This thesis details the design procedure for two different control methods. The first is a suboptimal tracking controller using a linear quadratic regulator (LQR) with integral action. The second is the design of several adaptive sliding mode controller to provide robust tracking control of the TRMS. Once the design is complete the controllers are tested in simulation and their performance is compared against a PID controller experimentally. The performance of the controllers are also compared against other controllers in the literature. The ability of the sliding mode controllers (SMC) to suppress chattering is also be explored.

  14. Temperature control for high pressure processes up to 1400 MPa

    Science.gov (United States)

    Reineke, K.; Mathys, A.; Heinz, V.; Knorr, D.

    2008-07-01

    Pressure- assisted sterilisation is an emerging technology. Hydrostatic high pressure can reduce the thermal load of the product and this allows quality retention in food products. To guarantee the safety of the sterilisation process it is necessary to investigate inactivation kinetics especially of bacterial spores. A significant roll during the inactivation of microorganisms under high pressure has the thermodynamic effect of the adiabatic heating. To analyse the individual effect of pressure and temperature on microorganism inactivation an exact temperature control of the sample to reach ideal adiabatic conditions and isothermal dwell times is necessary. Hence a heating/cooling block for a high pressure unit (Stansted Mini-Food-lab; high pressure capillary with 300 μL sample volume) was constructed. Without temperature control the sample would be cooled down during pressure built up, because of the non-adiabatic heating of the steel made vessel. The heating/cooling block allows an ideal adiabatic heat up and cooling of the pressure vessel during compression and decompression. The high pressure unit has a pressure build-up rate up to 250 MPa s-1 and a maximum pressure of 1400 MPa. Sebacate acid was chosen as pressure transmitting medium because it had no phase shift over the investigate pressure and temperature range. To eliminate the temperature difference between sample and vessel during compression and decompression phase, the mathematical model of the adiabatic heating/cooling of water and sebacate acid was implemented into a computational routine, written in Test Point. The calculated temperature is the setpoint of the PID controller for the heating/cooling block. This software allows an online measurement of the pressure and temperature in the vessel and the temperature at the outer wall of the vessel. The accurate temperature control, including the model of the adiabatic heating opens up the possibility to realise an ideal adiabatic heating and cooling as

  15. Temperature control for high pressure processes up to 1400 MPa

    Energy Technology Data Exchange (ETDEWEB)

    Reineke, K; Mathys, A; Knorr, D [Berlin University of Technology, Department of Food Biotechnology and Food Process Engineering, Koenigin-Luise-Str. 22, D-14195 Berlin (Germany); Heinz, V [German Institute of Food Technology, p. o. box: 1165, D-49601, Quackenbrueck (Germany)], E-mail: alexander.mathys@tu-berlin.de

    2008-07-15

    Pressure- assisted sterilisation is an emerging technology. Hydrostatic high pressure can reduce the thermal load of the product and this allows quality retention in food products. To guarantee the safety of the sterilisation process it is necessary to investigate inactivation kinetics especially of bacterial spores. A significant roll during the inactivation of microorganisms under high pressure has the thermodynamic effect of the adiabatic heating. To analyse the individual effect of pressure and temperature on microorganism inactivation an exact temperature control of the sample to reach ideal adiabatic conditions and isothermal dwell times is necessary. Hence a heating/cooling block for a high pressure unit (Stansted Mini-Food-lab; high pressure capillary with 300 {mu}L sample volume) was constructed. Without temperature control the sample would be cooled down during pressure built up, because of the non-adiabatic heating of the steel made vessel. The heating/cooling block allows an ideal adiabatic heat up and cooling of the pressure vessel during compression and decompression. The high pressure unit has a pressure build-up rate up to 250 MPa s{sup -1} and a maximum pressure of 1400 MPa. Sebacate acid was chosen as pressure transmitting medium because it had no phase shift over the investigate pressure and temperature range. To eliminate the temperature difference between sample and vessel during compression and decompression phase, the mathematical model of the adiabatic heating/cooling of water and sebacate acid was implemented into a computational routine, written in Test Point. The calculated temperature is the setpoint of the PID controller for the heating/cooling block. This software allows an online measurement of the pressure and temperature in the vessel and the temperature at the outer wall of the vessel. The accurate temperature control, including the model of the adiabatic heating opens up the possibility to realise an ideal adiabatic heating and

  16. Temperature control for high pressure processes up to 1400 MPa

    International Nuclear Information System (INIS)

    Pressure- assisted sterilisation is an emerging technology. Hydrostatic high pressure can reduce the thermal load of the product and this allows quality retention in food products. To guarantee the safety of the sterilisation process it is necessary to investigate inactivation kinetics especially of bacterial spores. A significant roll during the inactivation of microorganisms under high pressure has the thermodynamic effect of the adiabatic heating. To analyse the individual effect of pressure and temperature on microorganism inactivation an exact temperature control of the sample to reach ideal adiabatic conditions and isothermal dwell times is necessary. Hence a heating/cooling block for a high pressure unit (Stansted Mini-Food-lab; high pressure capillary with 300 μL sample volume) was constructed. Without temperature control the sample would be cooled down during pressure built up, because of the non-adiabatic heating of the steel made vessel. The heating/cooling block allows an ideal adiabatic heat up and cooling of the pressure vessel during compression and decompression. The high pressure unit has a pressure build-up rate up to 250 MPa s-1 and a maximum pressure of 1400 MPa. Sebacate acid was chosen as pressure transmitting medium because it had no phase shift over the investigate pressure and temperature range. To eliminate the temperature difference between sample and vessel during compression and decompression phase, the mathematical model of the adiabatic heating/cooling of water and sebacate acid was implemented into a computational routine, written in Test Point. The calculated temperature is the setpoint of the PID controller for the heating/cooling block. This software allows an online measurement of the pressure and temperature in the vessel and the temperature at the outer wall of the vessel. The accurate temperature control, including the model of the adiabatic heating opens up the possibility to realise an ideal adiabatic heating and cooling as

  17. Impact of individually controlled facially applied air movement on perceived air quality at high humidity

    DEFF Research Database (Denmark)

    Skwarczynski, Mariusz; Melikov, Arsen Krikor; Kaczmarczyk, J.;

    2010-01-01

    The effect of facially applied air movement on perceived air quality (PAQ) at high humidity was studied. Thirty subjects (21 males and 9 females) participated in three, 3-h experiments performed in a climate chamber. The experimental conditions covered three combinations of relative humidity and...... local air velocity under a constant air temperature of 26 degrees C, namely: 70% relative humidity without air movement, 30% relative humidity without air movement and 70% relative humidity with air movement under isothermal conditions. Personalized ventilation was used to supply room air from the front...... room air temperature of 26 degrees C and relative humidity of 70%....

  18. Case Study of Various Parameters by Applying Swing Up Control for Inverted Pendulum

    Directory of Open Access Journals (Sweden)

    Kunal Chakraborty

    2015-09-01

    Full Text Available This paper investigates behavior of the system in terms of time response e.g., steady state error, rise time & overshoot & then compare it with FLC. Being an unstable system, Inverted Pendulum is very common control problem being assigned to control its dynamics. It is almost impossible to balance a pendulum in the inverted position except applying some force from outside to the system.

  19. Simulations of modal active control applied to the self-sustained oscillations of the clarinet

    OpenAIRE

    Meurisse, Thibaut; MAMOU-MANI, Adrien; Caussé, René; SHARP, David

    2013-01-01

    Modal active control enables modifications of the damping and the frequencies of the different resonances of a system. A self-sustained oscillating wind instrument is modelled as a disturbance coupled to a resonator through a non-linear coupling. The aim of this study is to present simulations of modal active control applied to a modeled simplified self-sustained oscillating wind instrument (e.g. a cylindrical tube coupled to a reed, which is considered to approximate a simplified clarinet), ...

  20. Controlled Delivery of Human Cells by Temperature Responsive Microcapsules

    Directory of Open Access Journals (Sweden)

    W.C. Mak

    2015-06-01

    Full Text Available Cell therapy is one of the most promising areas within regenerative medicine. However, its full potential is limited by the rapid loss of introduced therapeutic cells before their full effects can be exploited, due in part to anoikis, and in part to the adverse environments often found within the pathologic tissues that the cells have been grafted into. Encapsulation of individual cells has been proposed as a means of increasing cell viability. In this study, we developed a facile, high throughput method for creating temperature responsive microcapsules comprising agarose, gelatin and fibrinogen for delivery and subsequent controlled release of cells. We verified the hypothesis that composite capsules combining agarose and gelatin, which possess different phase transition temperatures from solid to liquid, facilitated the destabilization of the capsules for cell release. Cell encapsulation and controlled release was demonstrated using human fibroblasts as model cells, as well as a therapeutically relevant cell line—human umbilical vein endothelial cells (HUVECs. While such temperature responsive cell microcapsules promise effective, controlled release of potential therapeutic cells at physiological temperatures, further work will be needed to augment the composition of the microcapsules and optimize the numbers of cells per capsule prior to clinical evaluation.

  1. Fermilab linac upgrade side coupled cavity temperature control system

    International Nuclear Information System (INIS)

    Each cavity section has a temperature control system which maintains the resonant frequency by exploiting the 17.8 ppm/degree C frequency sensitivity of the copper cavities. Each accelerating cell has a cooling tube brazed azimuthally to the outside surface. Alternate supply and return connection to the water manifolds reduce temperature gradients and maintain physical alignment of the cavity string. Special tubing with spiral inner fins and large flow rate are used to reduce the film coefficient. Temperature is controlled by mixing chilled water with the water circulating between the cavity and the cooling skid located outside the radiation enclosure. Chilled water flow is regulated with a valve controlled by a local microcomputer. The temperature loop set point will be obtained from a slower loop which corrects the phase error between the cavity section and the rf drive during normal beam loaded conditions. Time constants associated with thermal gradients induced in the cavity with the rf power require programming it to the nominal 7.1 MW level over a 1 minute interval to limit the reverse power. 4 refs., 4 figs

  2. Fermilab linac upgrade side coupled cavity temperature control system

    International Nuclear Information System (INIS)

    Each cavity section has a temperature control system which maintains the resonant frequency by exploiting the 17.8 ppm/C frequency sensitivity of the copper cavities. Each accelerating cell has a cooling tube brazed azimuthally to the outside surface. Alternate supply and return connection to the water manifolds reduce temperature gradients and maintain physical alignment of the cavity string. Special tubing with a spiral inner fins and a large flow rate are used to reduce the film coefficient. Temperature is controlled by mixing chilled water with the water circulating between the cavity and the cooling skid located outside the radiation enclosure. Chilled water flow is regulated with a valve controlled by a local micro computer. The temperature loop set point will be obtained from a slower loop which corrects the phase error between the cavity section and the rf drive during normal beam loaded conditions. Time constants associated with thermal gradients induced in the cavity with the rf power require programming it to the nominal 7.1 MW level over a 1 minute interval to limit the reverse power

  3. Analysis of the control of the high temperature gas-cooled reactor nuclear power plants

    International Nuclear Information System (INIS)

    Modular High Temperature Gas-Cooled Reactor (MHTGR) is characterized by inherent safety and higher electrical efficiency, so it can effectively improve the safety and economics of the nuclear power plants. Based upon these advantages, the High Temperature Gas-Cooled Reactor-Pebble Bed Module (HTR-PM) is under design and will be constructed in China to demonstrate the safety and economics of MHTGR. The automatic control system is important and necessary to the safe, economical, and efficient operation of the MHTGR. This paper investigates the control characteristics of the HTGR nuclear power plants, and analyzes the control technique and existing control strategies of HTGR plants. Advanced control technology which applies modern and intelligent control theory in industrial process provides an opportunity to improve the control performance of the MHTGR plant. Based upon the advanced control technology, the paper proposes a preliminary design concept of hierarchical coordinated control system to the control system design of the HTR-PM which employs the Distributed Control System (DCS) principle. (author)

  4. Force-free coil principles applied to high-temperature superconducting materials

    International Nuclear Information System (INIS)

    Force-free magnetic-field configurations, where the current flows parallel to the magnetic field vector, have the potential to raise the critical magnetic field and current-density limits for high-temperature superconductors. 10 refs., 3 figs

  5. Calculation of Liquidus Temperature for Aluminum and Magnesium Alloys Applying Method of Equivalency

    OpenAIRE

    Mile B. Djurdjević; Srećko Manasijević; Zoran Odanović; Natalija Dolić

    2013-01-01

    The purpose of this paper is to develop a mathematical equation, which will be able to accurately predict the liquidus temperature of various aluminum and magnesium cast alloys on the basis of their known chemical compositions. An accurate knowledge of liquidus temperature permits a researcher to predict a variety of physical parameters pertaining to a given alloy. The analytical expressions presented in this paper are based on the “method of equivalency.” According to this concept, the influ...

  6. Calculation of Liquidus Temperature for Aluminum and Magnesium Alloys Applying Method of Equivalency

    Directory of Open Access Journals (Sweden)

    Mile B. Djurdjević

    2013-01-01

    Full Text Available The purpose of this paper is to develop a mathematical equation, which will be able to accurately predict the liquidus temperature of various aluminum and magnesium cast alloys on the basis of their known chemical compositions. An accurate knowledge of liquidus temperature permits a researcher to predict a variety of physical parameters pertaining to a given alloy. The analytical expressions presented in this paper are based on the “method of equivalency.” According to this concept, the influence of any alloying element on the liquidus temperature of an aluminum and/or magnesium alloy can be translated into the equivalent influence of a reference element. Silicon as a reference element has been chosen for aluminum alloys and aluminum for magnesium alloys. The sum of the equivalent concentrations for other elements, when added to the influence of the actual reference element is used to calculate the liquidus temperature of the alloy. The calculated liquidus temperatures for wide ranges of alloy chemical compositions show a good correlation with corresponding measured liquidus temperatures.

  7. Gold nanocrescents for remotely measuring and controlling local temperature

    International Nuclear Information System (INIS)

    We present a novel technique to remotely measure and control the local temperature within a medium. This technique is based on the observation of the rotational Brownian motion of gold nanocrescent particles, which possess a strong anisotropic light interaction due to their plasmonic properties. Rotational scattering correlation spectroscopy performed on a single nanoparticle is able to determine the local temperature with high accuracy. These nano-thermometers can simultaneously play the role of nano-heaters when absorbing the light of a focused laser beam. (paper)

  8. High-temperature oxidation of graphite rods with temperature control by combustion gas recycle

    International Nuclear Information System (INIS)

    The combustion of graphite (fuel blocks) is of fundamental importance in the fuel reprocessing scheme for the High-Temperature Gas-Cooled Reactor (HTGR). A study was made to evaluate a chunk-type burner for possible application in this reprocessing step. The combustion gases were recycled to allow operation at higher burn rates without an increase in graphite temperature. Graphite rods of two diameters were oxidized with makeup oxygen and recycled stack gases at various gas flow rates in an insulated reactor. Results of this study indicate a strong dependence of oxygen transfer on gas flow rate with little effect resulting from changes in graphite temperature. High carbon monoxide concentrations in the exit gas were not a problem except at oxygen concentrations below approx. 5%. Stable operation of a recycle controlled burner was achieved, avoiding the temperature excursions common in previous graphite burners

  9. Proppant-flowback control in high-temperature wells

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-06-01

    Proppant flowback following fracturing treatments can be controlled by use of resin-coated proppant, inorganic fibers, or polymer strips. Each of these technologies has limitations. Resin-coated proppants cannot be used above 374 F and require an activator below 158 F. Thermoplastic strips cannot be used at temperatures above their melting point. Glass fibers have been used successfully for proppant-flowback control, but they cannot be used at reservoir temperatures below 302 F, they provide only short-term control in carbonate reservoirs, and they cannot be used in an environment where they would be exposed to HF. A new high-performance fiber for proppant-flow-back control has been developed to overcome these limitations. In laboratory testing, these fibers were resistant to steam, diesel, xylene, HCl, and mud acid at temperatures up to 482 F for periods up to 7 months. Field testing in deep, hot, carbonate reservoirs confirmed the performance of the new fiber. Case histories of gas wells are given.

  10. Open-air type plasma chemical vaporization machining by applying pulse-width modulation control

    Science.gov (United States)

    Takeda, Yoshiki; Hata, Yuki; Endo, Katsuyoshi; Yamamura, Kazuya

    2014-03-01

    Photolithography techniques have been used to enable the low-cost and high-speed transfer of a pattern onto a silicon wafer. However, owing to the high integration of semiconductors, extreme ultraviolet will be increasingly used as the exposure light source and all optics must be reflective to focus light because the wavelength of the light will be so short that it cannot pass through a lens. The form accuracy of reflective optics affects the accuracy of transfer, and a flatness of less than 32 nm on a 6 inch photomask substrate is required according to the International Technology Roadmap for Semiconductors roadmap. Plasma chemical vaporization machining is an ultraprecise figuring technique that enables a form accuracy of nanometre order to be obtained. In our previous study, the removal volume was controlled by changing the scanning speed of the worktable. However, a discrepancy between the theoretical scanning speed and the actual scanning speed occurred owing to the inertia of the worktable when the change in speed was rapid. As an attempt to resolve this issue, we controlled the removal volume by controlling the electric power applied during plasma generation while maintaining a constant scanning speed. The methods that we adapted to control the applied electric power were amplitude-modulation (AM) control and pulse-width modulation (PWM) control. In this work, we evaluate the controllability of the material removal rate in the AM and PWM control modes.

  11. Open-air type plasma chemical vaporization machining by applying pulse-width modulation control

    International Nuclear Information System (INIS)

    Photolithography techniques have been used to enable the low-cost and high-speed transfer of a pattern onto a silicon wafer. However, owing to the high integration of semiconductors, extreme ultraviolet will be increasingly used as the exposure light source and all optics must be reflective to focus light because the wavelength of the light will be so short that it cannot pass through a lens. The form accuracy of reflective optics affects the accuracy of transfer, and a flatness of less than 32 nm on a 6 inch photomask substrate is required according to the International Technology Roadmap for Semiconductors roadmap. Plasma chemical vaporization machining is an ultraprecise figuring technique that enables a form accuracy of nanometre order to be obtained. In our previous study, the removal volume was controlled by changing the scanning speed of the worktable. However, a discrepancy between the theoretical scanning speed and the actual scanning speed occurred owing to the inertia of the worktable when the change in speed was rapid. As an attempt to resolve this issue, we controlled the removal volume by controlling the electric power applied during plasma generation while maintaining a constant scanning speed. The methods that we adapted to control the applied electric power were amplitude-modulation (AM) control and pulse-width modulation (PWM) control. In this work, we evaluate the controllability of the material removal rate in the AM and PWM control modes. (paper)

  12. Burn control via regulated ripple applied to reactor-grade plasmas

    International Nuclear Information System (INIS)

    An investigation is made of the possibility of dynamically controlling the operating point of an ignited tokamak plasma by variation of the current in ripple 'correction' coils. The analysis is applied to designs presently under consideration for engineering test devices. (author)

  13. Optoacoustic temperature determination and automatic coagulation control in rabbits

    Science.gov (United States)

    Schlott, Kerstin; Koinzer, Stefan; Ptaszynski, Lars; Luft, Susanne; Baade, Alex; Bever, Marco; Roider, Johann; Birngruber, Reginald; Brinkmann, Ralf

    2011-03-01

    Retinal laser photocoagulation is an established treatment method for many retinal diseases like macula edema or diabetic retinopathy. The selection of the laser parameters is so far based on post treatment evaluation of the lesion size and strength. Due to local pigment variations in the fundus and individual transmission the same laser parameters often lead to an overtreatment. Optoacoustic allows a non invasive monitoring of the retinal temperature increase during retinal laser irradiation by measuring the temperature dependent pressure amplitudes, which are induced by short probe laser pulses. A 75 ns/ 523 nm Nd:YLF was used as a probe laser at a repetition rate of 1 kHz, and a cw / 532 nm treatment laser for heating. A contact lens was modified with a ring-shaped ultrasonic transducer to detect the pressure waves at the cornea. Temperatures were collected for irradiations leading to soft or invisible lesions. Based on this data the threshold for denaturation was found. By analyzing the initial temperature increase, the further temperature development during irradiation could be predicted. An algorithm was found to calculate the irradiation time, which is needed for a soft lesion formation, from the temperature curve. By this it was possible to provide a real-time dosimetry by automatically switching off the treatment laser after the calculated irradiation time. Automatically controlled coagulations appear softer and more uniformly.

  14. Capsule temperature control system development by using of vacuum and heater control method

    Energy Technology Data Exchange (ETDEWEB)

    Kim, C. H.; Seo, S. M.; Park, S. J.; Kang, Y. H. [KAERI, Taejon (Korea, Republic of)

    1998-10-01

    An overview is presented of the development of the capsule temperature control system(CTCS) used in the HANARO reactor to obtain the information essential to the design of advanced nuclear materials and the integrity evaluation of the conventional power reactor materials. The CTCS consists of two sub-systems: a vacuum control system and a multi-stage heater control system. These two sub-systems cooperate to effectively control the temperature of the specimen. A series of the performance tests were done in the test hole CT and IR2 of HANARO and test results are reviewed in detail.

  15. Temperature control of bench-scaled batch reactor equipped with a monofluid heating/cooling system

    Science.gov (United States)

    Teng, Hai-peng; Song, Yi-ming

    2014-04-01

    An advanced control concept, Predictive Functional Control (PFC), is applied for temperature control of a bench-scaled batch reactor equipped with monofluid heating/cooling system. First principles process models are developed. Based on achieved models, significant process variables, which are difficult or impossible to measure online, are estimated from easily measured variables, and cascade PFC control strategy has been projected and implemented in Matlab R14. The dynamics of individual subunits is explicitly taken into consideration by internal model in the control algorithms, and model uncertainty, various process disturbances are compensated by modification of internal model. The experimental results present an excellent capability of tracking the set point, and the success of PFC technique as a process control paradigm is illustratively demonstrated.

  16. Schlieren technique applied to the arc temperature measurement in a high energy density cutting torch

    International Nuclear Information System (INIS)

    Plasma temperature and radial density profiles of the plasma species in a high energy density cutting arc have been obtained by using a quantitative schlieren technique. A Z-type two-mirror schlieren system was used in this research. Due to its great sensibility such technique allows measuring plasma composition and temperature from the arc axis to the surrounding medium by processing the gray-level contrast values of digital schlieren images recorded at the observation plane for a given position of a transverse knife located at the exit focal plane of the system. The technique has provided a good visualization of the plasma flow emerging from the nozzle and its interactions with the surrounding medium and the anode. The obtained temperature values are in good agreement with those values previously obtained by the authors on the same torch using Langmuir probes.

  17. Energy (mass) transfer processes in low-temperature plasma as applied to forming ordered structures

    Science.gov (United States)

    Abramenko, T. N.; Laktyushina, T. V.; Laktyushin, A. N.

    2000-03-01

    The methods of irreversible thermodynamics are adopted to analyze the energy (mass) transfer in gases (their mixtures) over a wide temperature range up to 20000 K. An energy transfer process is considered as a path in the state space, and a concept of non-Euclidean state space is postulated. Experimental data on the gas thermal conductivity over a wide temperature range is generalized by the methods of thermodynamic similarity theory. Thermal conductivities of CH4-O2 and CH4-H2O mixtures are calculated for technological applications. The process of forming a space-time structure is analyzed by using the experimental data on the gas thermal conductivity over a wide temperature range. An attempt is made to interpret the mechanism of the thermal diffusion in gases due to the forming of ordered structures. A contribution of the diffusional thermoeffect to the energy transfer processes in a three-component nitrogen plasma is calculated.

  18. High temperature strength of ceramic moulds applied in the investment casting method

    Directory of Open Access Journals (Sweden)

    J. Kolczyk

    2011-07-01

    Full Text Available Ceramic casting moulds strength is an important factor, which influences the quality and properties of castings being produced by the investment casting method. It is especially important during mould pouring with liquid metal. Studies allowing determining the casting mould strength at high temperatures, that means at the ones at which the moulds are poured, are not numerous. None generally accepted (normalized method for the assessment of such strength exists in practice. The new method of the ceramic mouldso tensile strength investigation at high temperatures is described in the paper. Tests were performed at temperatures from 100 to 1100 C. The ceramic moulding sand was prepared of modern materials: colloidal silica – being a binder – and highly refractory ceramic materials.

  19. Feedback control strategy of longitudinal temperature and finished carbonization time for coke oven and its application

    Institute of Scientific and Technical Information of China (English)

    Fang Huo; Zhi Wen; Dong Chen; Yueling Shen; Yongqin Zhang; Xiaoming Zhi

    2004-01-01

    Based on the detailed analysis of the third coke oven in BaoSteel, a feedback control strategy of longitudinal temperature and finished carbonization time of coke ovens was proposed and it was applied to the third coke oven in BaoSteel. As a result, the ratio of the instance that the absolute deviation of the longitudinal temperature is within ±7°C and the finished carbonization time within ± 10 rain is more than 80%, having acquired the patent saving effect of an energy consumption lowered by 2.92%. At the same time, it can provide an example for the same coke ovens inside and outside the nation.

  20. Adaptive Process Controls and Ultrasonics for High Temperature PEM MEA Manufacture

    Energy Technology Data Exchange (ETDEWEB)

    Walczyk, Daniel F. [Rensselaer Polytechnic Inst., Troy, NY (United States)

    2015-08-26

    The purpose of this 5-year DOE-sponsored project was to address major process bottlenecks associated with fuel cell manufacturing. New technologies were developed to significantly reduce pressing cycle time for high temperature PEM membrane electrode assembly (MEA) through the use of novel, robust ultrasonic (U/S) bonding processes along with low temperature (<100°C) PEM MEAs. In addition, greater manufacturing uniformity and performance was achieved through (a) an investigation into the causes of excessive variation in ultrasonically and thermally bonded MEAs using more diagnostics applied during the entire fabrication and cell build process, and (b) development of rapid, yet simple quality control measurement techniques for use by industry.

  1. Sampling theory applied to measurement and analysis of temperature for climate studies

    Science.gov (United States)

    Edwards, Howard B.

    1987-01-01

    Of all the errors discussed in climatology literature, aliasing errors caused by undersampling of unsmoothed or improperly smoothed temperature data seem to be completely overlooked. This is a serious oversight in view of long-term trends of 1 K or less. Adequate sampling of properly smoothed data is demonstrated with a Hamming digital filter. It is also demonstrated that hourly temperatures, daily averages, and annual averages free of aliasing errors can be obtained by use of a microprocessor added to standard weather sensors and recorders.

  2. Analysis results for the stereotypes regarding colors applied to the nuclear power plant control room

    International Nuclear Information System (INIS)

    The general public not engaged in the nuclear power plant industry have no idea of the color usage in the nuclear control room. So we converted the specific color usage situation into similar but general situations. In questionnaire, we gave subjects the general situation where color coding is applied and alternative colors which were applied to the HF010 guidelines. And we asked the subjects to choose the colors proper to the situation and to rank the colors according to the degree of suitability. Two hundred fifty college students participated in the experiment. The results suggest that we can use any color coding system in the conventional control room and the CRT in the control deck because most people have no special previous color-meaning association but red-emergency relation

  3. Room temperature coherent control of coupled single spins in solid

    CERN Document Server

    Gaebel, T; Popa, I; Wittmann, C; Neumann, P; Jelezko, F; Rabeau, J R; Stavrias, N; Greentree, A D; Prawer, S; Meijer, J; Twamley, J; Hemmer, P R; Wrachtrup, J

    2006-01-01

    Coherent coupling between single quantum objects is at the heart of modern quantum physics. When coupling is strong enough to prevail over decoherence, it can be used for the engineering of correlated quantum states. Especially for solid-state systems, control of quantum correlations has attracted widespread attention because of applications in quantum computing. Such coherent coupling has been demonstrated in a variety of systems at low temperature1, 2. Of all quantum systems, spins are potentially the most important, because they offer very long phase memories, sometimes even at room temperature. Although precise control of spins is well established in conventional magnetic resonance3, 4, existing techniques usually do not allow the readout of single spins because of limited sensitivity. In this paper, we explore dipolar magnetic coupling between two single defects in diamond (nitrogen-vacancy and nitrogen) using optical readout of the single nitrogen-vacancy spin states. Long phase memory combined with a d...

  4. Northwestern Pacific typhoon intensity controlled by changes in ocean temperatures.

    Science.gov (United States)

    Mei, Wei; Xie, Shang-Ping; Primeau, François; McWilliams, James C; Pasquero, Claudia

    2015-05-01

    Dominant climatic factors controlling the lifetime peak intensity of typhoons are determined from six decades of Pacific typhoon data. We find that upper ocean temperatures in the low-latitude northwestern Pacific (LLNWP) and sea surface temperatures in the central equatorial Pacific control the seasonal average lifetime peak intensity by setting the rate and duration of typhoon intensification, respectively. An anomalously strong LLNWP upper ocean warming has favored increased intensification rates and led to unprecedentedly high average typhoon intensity during the recent global warming hiatus period, despite a reduction in intensification duration tied to the central equatorial Pacific surface cooling. Continued LLNWP upper ocean warming as predicted under a moderate [that is, Representative Concentration Pathway (RCP) 4.5] climate change scenario is expected to further increase the average typhoon intensity by an additional 14% by 2100. PMID:26601179

  5. Northwestern Pacific Typhoon Intensity Controlled by Changes in Ocean Temperatures

    Science.gov (United States)

    Mei, W.; Xie, S. P.; Primeau, F.; McWilliams, J. C.; Pasquero, C.

    2015-12-01

    Dominant climatic factors controlling the lifetime peak intensity of typhoons are determined from six decades of Pacific typhoon data. We find that upper ocean temperatures in the low-latitude northwestern Pacific (LLNWP) and sea surface temperatures in the central equatorial Pacific control the seasonal average lifetime peak intensity by setting the rate and duration of typhoon intensification, respectively. An anomalously strong LLNWP upper ocean warming has favored increased intensification rates and led to unprecedentedly high average typhoon intensity during the recent global warming hiatus period, despite a reduction in intensification duration tied to the central equatorial Pacific surface cooling. Continued LLNWP upper ocean warming as predicted under a moderate (i.e., RCP 4.5) climate change scenario is expected to further increase the average typhoon intensity by an additional 14% by 2100.

  6. High Temperature PEM Fuel Cell Systems, Control and Diagnostics

    DEFF Research Database (Denmark)

    Andreasen, Søren Juhl; Kær, Søren Knudsen; Justesen, Kristian Kjær; Sahlin, Simon Lennart

    fuels utilizes one of the main advantages of the high temperature PEM fuel cell: robustness to fuel quality and impurities. In order for such systems to provide efficient, robust, and reliable energy, proper control strategies are needed. The complexity and nonlinearity of many of the components in such......Various system topologies are available when it comes to designing high temperature PEM fuel cell systems. Very simple system designs are possible using pure hydrogen, and more complex system designs present themselves when alternative fuels are desired, using reformer systems. The use of reformed...... systems allow the development of both simple linear and also advanced fuzzy logic and neural network controllers able to adapt system performance to the ever changing conditions which the systems operate in over their entire lifetime....

  7. Study of thermocouples for control of high temperatures

    International Nuclear Information System (INIS)

    Previous works have shown that the tungsten-rhenium alloys thermocouples were a good instrument for control of high temperatures. From its, the author has studied the W/W 26 per cent and W 5 per cent Re/W 26 per cent Re french manufactured thermocouples and intended for control of temperatures in nuclear reactors until 2300 deg. C. In 'out-pile' study he determines the general characteristics of these thermocouples: average calibration curves, thermal shocks influence, response times, and alloys allowing the cold source compensation. The evolution of these thermocouples under thermal neutron flux has been determined by 'in-pile' study. The observations have led the author to propose a new type of thermocouples settled of molybdenum-columbium alloys. (author)

  8. Chemical control of rate and onset temperature of nadimide polymerization

    Science.gov (United States)

    Lauver, R. W.

    1985-01-01

    The chemistry of norbornenyl capped imide compounds (nadimides) is briefly reviewed with emphasis on the contribution of Diels-Alder reversion in controlling the rate and onset of the thermal polymerization reaction. Control of onset temperature of the cure exotherm by adjusting the concentration of maleimide is demonstrated using selected model compounds. The effects of nitrophenyl compounds as free radical retarders on nadimide reactivity are discussed. A simple copolymerization model is proposed for the overall nadimide cure reaction. An approximate numerical analysis is carried out to demonstrate the ability of the model to simulate the trends observed for both maleimide and nitrophenyl additions.

  9. Field Test of Boiler Primary Loop Temperature Controller

    Energy Technology Data Exchange (ETDEWEB)

    Glanville, P.; Rowley, P.; Schroeder, D.; Brand, L.

    2014-09-01

    Beyond these initial system efficiency upgrades are an emerging class of Advanced Load Monitoring (ALM) aftermarket controllers that dynamically respond to the boiler load, with claims of 10% to 30% of fuel savings over a heating season. For hydronic boilers specifically, these devices perform load monitoring, with continuous measurement of supply and in some cases return water temperatures. Energy savings from these ALM controllers are derived from dynamic management of the boiler differential, where a microprocessor with memory of past boiler cycles prevents the boiler from firing for a period of time, to limit cycling losses and inefficient operation during perceived low load conditions. These differ from OTR controllers, which vary boiler setpoint temperatures with ambient conditions while maintaining a fixed differential. PARR installed and monitored the performance of one type of ALM controller, the M2G from Greffen Systems, at multifamily sites in the city of Chicago and its suburb Cary, IL, both with existing OTR control. Results show that energy savings depend on the degree to which boilers are over-sized for their load, represented by cycling rates. Also savings vary over the heating season with cycling rates, with greater savings observed in shoulder months. Over the monitoring period, over-sized boilers at one site showed reductions in cycling and energy consumption in line with prior laboratory studies, while less over-sized boilers at another site showed muted savings.

  10. Control system for Fermilab`s low temperature upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Norris, B.L.

    1996-09-01

    Fermilab recently upgraded the Tevatron Cryogenic Systems to allow for lower temperature operation. This Lower Temperature Upgrade grew out of a desire to increase the Colliding Beam Physics energy from 900 GeV to 1000 GeV. A key element in achieving this goal is the new cryogenic control system designed at Fermilab and installed in 24 satellite refrigerators and 8 compressor buildings. The cryogenic improvements and addition hardware like cold compressors exceeded the capability of the original distributed controls package. The new distributed controls package uses a Multibus II platform and Intel`s 80386 microprocessor. Token Ring is used as the link to the systems 6 primary crate locations with Arcnet used as the connection to the systems numerous I/O crates. I/0 capabilities are double the capabilities of the original system. Software has also been upgraded with the introduction of more flexible control loop strategies and Finite State Machines used for automatic sequential control, like quench recovery or cold compressor pump down.

  11. Electric-field control of magnetic order above room temperature

    Science.gov (United States)

    Cherifi, R. O.; Ivanovskaya, V.; Phillips, L. C.; Zobelli, A.; Infante, I. C.; Jacquet, E.; Garcia, V.; Fusil, S.; Briddon, P. R.; Guiblin, N.; Mougin, A.; Ünal, A. A.; Kronast, F.; Valencia, S.; Dkhil, B.; Barthélémy, A.; Bibes, M.

    2014-04-01

    Controlling magnetism by means of electric fields is a key issue for the future development of low-power spintronics. Progress has been made in the electrical control of magnetic anisotropy, domain structure, spin polarization or critical temperatures. However, the ability to turn on and off robust ferromagnetism at room temperature and above has remained elusive. Here we use ferroelectricity in BaTiO3 crystals to tune the sharp metamagnetic transition temperature of epitaxially grown FeRh films and electrically drive a transition between antiferromagnetic and ferromagnetic order with only a few volts, just above room temperature. The detailed analysis of the data in the light of first-principles calculations indicate that the phenomenon is mediated by both strain and field effects from the BaTiO3. Our results correspond to a magnetoelectric coupling larger than previous reports by at least one order of magnitude and open new perspectives for the use of ferroelectrics in magnetic storage and spintronics.

  12. Design of new irradiation capsules for controlling temperature and fluence

    Energy Technology Data Exchange (ETDEWEB)

    Choo, K. N.; Choi, M. H.; Cho, M. S.; Shin, Y. T.; Kim, B. G. [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    2004-07-01

    Various irradiation devices have been developed at HANARO (High flux Advanced Neutron Application ReactOr). Among the irradiation facilities, a capsule is the most useful device to cope with various test requirements. Instrumented and non-instrumented capsules have been developed at HANARO for new alloy and fuel developments and the life time estimation of nuclear power plants. Extensive efforts have been made to establish design and manufacturing technology for the capsule and temperature control system, which should be compatible with HANARO's characteristics. 9 instrumented and 2 non-instrumented capsules were designed, fabricated and successfully irradiated since the first non-instrumented capsule (96M-01K) for various materials irradiation. In an irradiation test using a research reactor, temperature and fluence are mainly dependent of reactor operation condition such as reactor power mode and operation time. In consequence, the irradiated specimen is subjected to the change of temperature as well as of neutron flux during reactor power transient such as start-up and shut-down. A large difference in the defect structure has been reported to be caused by this transient irradiation from the mechanism of the defect structure development. Therefore, the development of new capsule technology has been required to overcome those limitations. In this paper, current status of development of the capsule for controlling temperature and fluence in HANARO is described.

  13. Design of new irradiation capsules for controlling temperature and fluence

    International Nuclear Information System (INIS)

    Various irradiation devices have been developed at HANARO (High flux Advanced Neutron Application ReactOr). Among the irradiation facilities, a capsule is the most useful device to cope with various test requirements. Instrumented and non-instrumented capsules have been developed at HANARO for new alloy and fuel developments and the life time estimation of nuclear power plants. Extensive efforts have been made to establish design and manufacturing technology for the capsule and temperature control system, which should be compatible with HANARO's characteristics. 9 instrumented and 2 non-instrumented capsules were designed, fabricated and successfully irradiated since the first non-instrumented capsule (96M-01K) for various materials irradiation. In an irradiation test using a research reactor, temperature and fluence are mainly dependent of reactor operation condition such as reactor power mode and operation time. In consequence, the irradiated specimen is subjected to the change of temperature as well as of neutron flux during reactor power transient such as start-up and shut-down. A large difference in the defect structure has been reported to be caused by this transient irradiation from the mechanism of the defect structure development. Therefore, the development of new capsule technology has been required to overcome those limitations. In this paper, current status of development of the capsule for controlling temperature and fluence in HANARO is described

  14. Room temperature coherent control of coupled single spins in solid

    OpenAIRE

    Gaebel, T.; Domhan, M.; Popa, I.; Wittmann, C; Neumann, P; Jelezko, F.; Rabeau, J. R.; Stavrias, N.; Greentree, A. D.; Prawer, S.; Meijer, J; Twamley, J.; Hemmer, P. R.; Wrachtrup, J.

    2006-01-01

    Coherent coupling between single quantum objects is at the heart of modern quantum physics. When coupling is strong enough to prevail over decoherence, it can be used for the engineering of correlated quantum states. Especially for solid-state systems, control of quantum correlations has attracted widespread attention because of applications in quantum computing. Such coherent coupling has been demonstrated in a variety of systems at low temperature1, 2. Of all quantum systems, spins are pote...

  15. Tropical cyclone rainfall area controlled by relative sea surface temperature

    OpenAIRE

    Lin, Yanluan; ZHAO Ming; Zhang, Minghua

    2015-01-01

    Tropical cyclone rainfall rates have been projected to increase in a warmer climate. The area coverage of tropical cyclones influences their impact on human lives, yet little is known about how tropical cyclone rainfall area will change in the future. Here, using satellite data and global atmospheric model simulations, we show that tropical cyclone rainfall area is controlled primarily by its environmental sea surface temperature (SST) relative to the tropical mean SST (that is, the relative ...

  16. Adaptive and Intelligent Temperature Control of Microwave Heating Systems with Multiple Sources

    OpenAIRE

    Sun, Yiming

    2016-01-01

    In this work, an innovative real-time microwave control approach is proposed, to improve the temperature homogeneity under microwave heating. Multiple adaptive or intelligent control structures have been developed, including the model predictive control, neural network control and reinforcement learning control methods. Experimental results prove that these advanced control methods can effectively reduce the final temperature derivations and improve the temperature homogeneity.

  17. Development of DMC controllers for temperature control of a room deploying the displacement ventilation HVAC system

    Directory of Open Access Journals (Sweden)

    Zhicheng Li, Ramesh K. Agarwal, Huijun Gao

    2013-01-01

    Full Text Available In this paper, by developing a new Dynamic Matrix Control (DMC method, we develop a controller for temperature control of a room cooled by a displacement ventilation HVAC system. The fluid flow and heat transfer inside the room are calculated by solving the Reynolds-Averaged Navier-Stokes (RANS equations including the effects of buoyancy in conjunction with a two-equation realizable k - epsilon turbulence model. Thus the physical environment is represented by a nonlinear system of partial differential equations. The system also has a large time delay because of the slowness of the heat exchange. The goal of the paper is to develop a controller that will maintain the temperature at three points near three different walls in a room within the specified upper and lower bounds. In order to solve this temperature control problem at three different points in the room, we develop a special DMC method. The results show that the newly developed DMC controller is an effective controller to maintain temperature within desired bounds at multiple points in the room and also saves energy when compared to other controllers. This DMC method can also be employed to develop controllers for other HVAC systems such as the overhead VAV (Variable Air Volume system and the radiant cooling hydronic system.

  18. Influence of the Annealing Temperature on the Photovoltaic Performance and Film Morphology Applying Novel Thermocleavable Materials

    DEFF Research Database (Denmark)

    Petersen, Martin Helgesen; Bjerring, Morten; Nielsen, Niels Chr.;

    2010-01-01

    a weight loss around 200 °C corresponding to elimination of the ester side chains followed by a second weight loss around 300 °C corresponding to loss of CO2 via decarboxylation. The temperature of thermocleavage of the active layer films was optimized to 265 °C whereby the T2:PCBM solar cells...

  19. The simulation of skin temperature distributions by means of a relaxation method (applied to IR thermography)

    NARCIS (Netherlands)

    Vermey, G.F.

    1975-01-01

    To solve the differential equation for the heat in a two-layer, rectangular piece of skin tissue, a relaxation method, based on a finite difference technique, is used. The temperature distributions on the skin surface are calculated. The results are used to derive a criterion for the resolution for

  20. DIII-D integrated plasma control tools applied to next generation tokamaks

    International Nuclear Information System (INIS)

    A complete software suite for integrated tokamak plasma control has been developed within the DIII-D program. The suite consists of software for real-time control of all aspects of the plasma, modeling, simulation and design tools for analysis and development of controllers, a flexible and modular architecture for implementation and testing of algorithms and many fully validated models. Many elements of the system have been applied to and implemented on NSTX and MAST. The DIII-D realtime plasma control system together with the integrated modeling and simulation suite have been selected for operational use by both the KSTAR and EAST tokamaks, and are also being used at General Atomics to investigate control issues for ITER

  1. Total quality control: the deming management philosophy applied to nuclear power plants

    International Nuclear Information System (INIS)

    In recent years, a call has come for the development of inherently safe nuclear reactor systems that cannot have large-scale accidents. In the search for the perfect inherently safe reactor system, some are calling for the institution of computerized automated control of reactors eliminating most human operators from the control room. A different approach to the problem of the control of inherently safe reactors is that both future and present nuclear power plants need to institute total quality control (TQC) to plant operations and management. The Deming management philosophy of TQC has been implemented in a wide range of industries - particularly in Japan and the US. Specific attention is given, however, to TQC implementation in the electric power industry as applied to nuclear plants. The Kansai Electric Power Company and Florida Power and Light Company have recently implemented TQC. Statistical quality control methods have been applied to monitor and control reactor variables (for example, to the steam generator water level important to start-up operations of pressurized water reactors)

  2. Identifying a cooperative control mechanism between an applied field and the environment of open quantum systems

    Science.gov (United States)

    Gao, Fang; Rey-de-Castro, Roberto; Wang, Yaoxiong; Rabitz, Herschel; Shuang, Feng

    2016-05-01

    Many systems under control with an applied field also interact with the surrounding environment. Understanding the control mechanisms has remained a challenge, especially the role played by the interaction between the field and the environment. In order to address this need, here we expand the scope of the Hamiltonian-encoding and observable-decoding (HE-OD) technique. HE-OD was originally introduced as a theoretical and experimental tool for revealing the mechanism induced by control fields in closed quantum systems. The results of open-system HE-OD analysis presented here provide quantitative mechanistic insights into the roles played by a Markovian environment. Two model open quantum systems are considered for illustration. In these systems, transitions are induced by either an applied field linked to a dipole operator or Lindblad operators coupled to the system. For modest control yields, the HE-OD results clearly show distinct cooperation between the dynamics induced by the optimal field and the environment. Although the HE-OD methodology introduced here is considered in simulations, it has an analogous direct experimental formulation, which we suggest may be applied to open systems in the laboratory to reveal mechanistic insights.

  3. Electromagnetic Acoustic Transducers Applied to High Temperature Plates for Potential Use in the Solar Thermal Industry

    OpenAIRE

    Maria Kogia; Liang Cheng; Abbas Mohimi; Vassilios Kappatos; Tat-Hean Gan; Wamadeva Balachandran; Cem Selcuk

    2015-01-01

    Concentrated Solar Plants (CSPs) are used in solar thermal industry for collecting and converting sunlight into electricity. Parabolic trough CSPs are the most widely used type of CSP and an absorber tube is an essential part of them. The hostile operating environment of the absorber tubes, such as high temperatures (400–550 °C), contraction/expansion, and vibrations, may lead them to suffer from creep, thermo-mechanical fatigue, and hot corrosion. Hence, their condition monitoring is of cruc...

  4. High temperature strength of ceramic moulds applied in the investment casting method

    OpenAIRE

    J. Kolczyk; Zych, J.

    2011-01-01

    Ceramic casting moulds strength is an important factor, which influences the quality and properties of castings being produced by the investment casting method. It is especially important during mould pouring with liquid metal. Studies allowing determining the casting mould strength at high temperatures, that means at the ones at which the moulds are poured, are not numerous. None generally accepted (normalized) method for the assessment of such strength exists in practice. The new method of ...

  5. Estimation of the soil temperature from the AVHRR-NOAA satellite data applying split window algorithms

    International Nuclear Information System (INIS)

    Four algorithms based on the technique of split-window, to estimate the land surface temperature starting from the data provided by the sensor Advanced Very High Resolution radiometer (AVHRR), on board the series of satellites of the National Oceanic and Atmospheric Administration (NOAA), are carried out. These algorithms consider corrections for atmospheric characteristics and emissivity of the different surfaces of the land. Fourteen images AVHRR-NOAA corresponding to the months of October of 2003, and January of 2004 were used. Simultaneously, measurements of soil temperature in the Carillanca hydro-meteorological station were collected in the Region of La Araucana, Chile (38 deg 41 min S; 72 deg 25 min W). Of all the used algorithms, the best results correspond to the model proposed by Sobrino and Raussoni (2000), with a media and standard deviation corresponding to the difference among the temperature of floor measure in situ and the estimated for this algorithm, of -0.06 and 2.11 K, respectively. (Author)

  6. Controlled Ensembles of Formaldehyde Molecules at Ultracold Temperatures

    Science.gov (United States)

    Zeppenfeld, Martin; Prehn, Alexander; Ibrügger, Martin; Glöckner, Rosa; Rempe, Gerhard

    2016-05-01

    Applications of ultracold molecules such as quantum information processing and quantum controlled chemistry require the preparation of ultracold molecule ensembles with a high level of control over all molecular degrees of freedom. Due to the inability to apply standard atom cooling techniques such as laser cooling to most molecule species, developing new methods is essential. We present a toolbox of techniques developed in our group for controlling molecules. A microstructured electric trap allows us to trap molecules in predominantly homogeneous electric fields with trapping times of up to a minute. Optical pumping on a vibrational transition allows us to transfer the population from a large number of rotational states to a single rotational M-sublevel. Our experiment provides excellent conditions for precision spectroscopy and investigation of ultracold collisions.

  7. Constant temperature molecular dynamics simulations of energetic particle-solid collisions: comparison of temperature control methods

    International Nuclear Information System (INIS)

    Appropriate temperature control methods must be incorporated into simulations that maintain constant temperature. A specific role played by these methods in modeling energetic particle-solid collisions is to absorb the excess energy wave generated by the collision that, if left unchecked, propagates through the material and reflects from the system boundaries. In this study, five temperature control methods are investigated for use in molecular dynamics simulations of carbon cluster deposition on diamond surfaces. These five methods are the Nose-Hoover thermostat, the generalized Langevin equation (GLEQ) approach, the Berendsen method, a modified GLEQ approach where an extra damping mechanism is introduced, and a combination of the GLEQ and Berendsen methods. The temperature control capability and the effectiveness of these methods at reducing the amplitude of the reflected energy wave produced in these systems are compared and discussed. It is found that the realistic performance of these methods depends on the specifics of the system, including incident energy and substrate size. Among the five methods considered, the Berendsen method is found to be effective at removing excess energy in the early stages of the deposition process, but the resultant final temperatures are relatively high in most cases. Additionally, the performance of the Nose-Hoover thermostat is similar to that of the Berendsen method. If the diamond substrate is large enough and the incident energy is not too high, the GLEQ approach is found to be sufficient for removal of excess energy. However, the modified GLEQ approach and the new, combined thermostat perform moderately better than the other approaches at high incident energies

  8. Single temperature sensor based evaporator filling control using excitation signal harmonics

    DEFF Research Database (Denmark)

    Vinther, Kasper; Rasmussen, Henrik; Izadi-Zamanabadi, Roozbeh;

    2012-01-01

    An important aspect of efficient and safe operation of refrigeration and air conditioning systems is superheat control for evaporators. This is conventionally controlled with a pressure sensor, a temperature sensor, an expansion valve and Proportional-Integral (PI) controllers or more advanced...... model based control. In this paper we show that superheat can be controlled without a pressure sensor and without a model of the system. This is achieved by continuous excitation of the system and by applying Fourier analysis, which gives an error signal that can be used together with standard PI...... a large operating range with only one sensor. It is believed that the method in general is applicable to a wide variety of nonlinear systems for which the desired operating points are close to points of zero mean curvature of system nonlinearities....

  9. Multi-Temperature Zone, Droplet-based Microreactor for Increased Temperature Control in Nanoparticle Synthesis

    KAUST Repository

    Erdem, E. Yegân

    2013-12-12

    Microreactors are an emerging technology for the controlled synthesis of nanoparticles. The Multi-Temperature zone Microreactor (MTM) described in this work utilizes thermally isolated heated and cooled regions for the purpose of separating nucleation and growth processes as well as to provide a platform for a systematic study on the effect of reaction conditions on nanoparticle synthesis. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Urea-SCR Temperature Investigation for NOx Control of Diesel Engine

    Directory of Open Access Journals (Sweden)

    Asif Muhammad

    2015-01-01

    Full Text Available SCR (selective catalytic reduction system is continuously being analyzed by many researchers worldwide on various concerns due to the stringent nitrogen oxides (NOx emissions legislation for heavy-duty diesel engines. Urea-SCR includes AdBlue as urea source, which subsequently decomposes to NH3 (ammonia being the reducing agent. Reaction temperature is a key factor for the performance of urea-SCR system, as urea decomposition rate is sensitive to a specific temperature range. This particular study was directed to investigate the temperature of the SCR system in diesel engine with the objective to confirm that whether the appropriate temperature is attained for occurrence of urea based catalytic reduction or otherwise and how the system performs on the prescribed temperature range. Diesel engine fitted with urea-SCR exhaust system has been operated on European standard cycle for emission testing to monitor the temperature and corresponding nitrogen oxides (NOx values on specified points. Moreover, mathematical expressions for approximation of reaction temperature are also proposed which are derived by applying energy conservation principal and gas laws. Results of the investigation have shown that during the whole testing cycle system temperature has remained in the range where urea-SCR can take place with best optimum rate and the system performance on account of NOx reduction was exemplary as excellent NOx conversion rate is achieved. It has also been confirmed that selective catalytic reduction (SCR is the best suitable technology for automotive engine-out NOx control.

  11. New cryogenic controls for the tevatron low temperature upgrade

    International Nuclear Information System (INIS)

    Fermilab's Tevatron accelerator is undergoing a major cryogenic system upgrade. This upgrade project is necessary to lower coil temperature of the accelerator's magnets by approximately 1K. The new system configuration utilizes a new valve box containing a 130 liter subcooling dewar and a Cold Compressor at each of the 24 satellite refrigerators. Each Cold Compressor pumps on a dewar to maintain the two-phase pressure at 50.7 kPa (0.5 atm) producing 3.56K helium in the dewar and magnet strings. The valve box and cold compressor installations, coupled with the need for new wet expander controllers and the addition of a significant amount of instrumentation, forced the immediate need for additional cryogenic control capabilities, which could only be met by major hardware and software upgrades. The additional requirements of the new cryogenic system doubled the number of I/O terminations per satellite, exceeding the capability of the original Multibus I, Z80-based distributed controls package. The original controls package, although highly successful over the last 10 year period, had already reached the upper limits of its capabilities with the many previous changes the cryogenic systems had undergone (i.e., Low Beta Magnet installations). The need for more digital and analog hardware, along with the desire for further control loop and automated controls features guided the new design

  12. Fractional-order integral and derivative controller for temperature profile tracking

    Indian Academy of Sciences (India)

    Hyo-Sung Ahn; Varsha Bhambhani; YangQuan Chen

    2009-10-01

    This paper establishes a new strategy to tune a fractional order integral and derivative (ID) controller satisfying gain and phase margins based on Bode’s ideal transfer function as a reference model, for a temperature profile tracking. A systematic analysis resulting in a non-linear equation relating user-defined gain and phase margins to the fractional order controller is derived. The closed-loop system designed has a feature of robustness to gain variations with step responses exhibiting a nearly iso-damping property. This paper aims to apply the analytical tuning procedure to control the heat flow systems at selected points in Quanser experimental platform. Thus, the main purpose of this paper is to examine performances of two different fractional order controllers in temperature profile tracking. From experimental comparisons with the traditional PI/PID controller based on Ziegler–Nichols’ tuning method, it will be shown that the proposed mathodologies are specifically beneficial in controlling temperature in time-delay heat flow systems.

  13. A Change Oriented Extension of EOF Analysis Applied to the 1996-1997 AVHRR Sea Surface Temperature Data

    OpenAIRE

    Nielsen, Allan Aasbjerg; Conradsen, Knut; Andersen, Ole Baltazar

    2002-01-01

    This paper describes the application of orthogonal transformations to detect multivariate change in the monthly mean sea surface temperature (SST) as given by the NOAA/NASA Oceans Pathfinder data. The transforms applied include multivariate alteration detection (MAD) variates based on canonical correlation analysis, and maximum autocorrelation factors (MAFs). The method described can be considered as an extension to EOF analysis that is specially tailored for change detection in spatial data ...

  14. Coherent control with shaped femtosecond laser pulses applied to ultracold molecules

    International Nuclear Information System (INIS)

    We report on coherent control of excitation processes of translationally ultracold rubidium dimers in a magneto-optical trap by using shaped femtosecond laser pulses. Evolution strategies are applied in a feedback loop in order to optimize the photoexcitation of the Rb2 molecules, which subsequently undergo ionization or fragmentation. A superior performance of the resulting pulses compared to unshaped pulses of the same pulse energy is obtained by distributing the energy among specific spectral components. The demonstration of coherent control to ultracold ensembles opens a path to actively influence fundamental photoinduced processes in molecular quantum gases

  15. Coherent control with shaped femtosecond laser pulses applied to ultracold molecules

    CERN Document Server

    Salzmann, W; Wester, R; Weidemüller, M; Merli, A; Weber, S M; Sauer, F; Plewicki, M; Weise, F; Esparza, A M; Wöste, L; Lindinger, A; Salzmann, Wenzel; Poschinger, Ulrich; Wester, Roland; Weidemueller, Matthias; Merli, Andrea; Weber, Stefan M.; Sauer, Franziska; Plewicki, Mateusz; Weise, Fabian; Esparza, Aldo Mirabal; Woeste, Ludger; Lindinger, Albrecht

    2005-01-01

    We report on coherent control of excitation processes of translationally ultracold rubidium dimers in a magneto-optical trap by using shaped femtosecond laser pulses. Evolution strategies are applied in a feedback loop in order to optimize the photoexcitation of the Rb2 molecules, which subsequently undergo ionization or fragmentation. A superior performance of the resulting pulses compared to unshaped pulses of the same pulse energy is obtained by distributing the energy among specific spectral components. The demonstration of coherent control to ultracold ensembles opens a path to actively influence fundamental photo-induced processes in molecular quantum gases.

  16. APPLIED ECONOMIC ORDER QUANTITY (EOQ) INLOGS RAW MATERIAL INVENTORY CONTROL FOR PLYWOOD INDUSTRY

    OpenAIRE

    Makkarennu; Nakayasu, A.; Osozawa, K.; Ichikawa, M

    2013-01-01

    One of the most difficult aspect of plywood industry is control inventory. Logs as the main raw material for plywood industry are the first and foremost form of inventory.Without proper planning, a manufacturing company can run out of raw material, negatively impacting the company and its customers. The aim of this study was to evaluate logs raw material inventory control applied at a plywood in South Sulawesi, Indonesia.For the purpose of the study, the data of logs raw material consumption ...

  17. Simulations of modal active control applied to the self-sustained oscillations of the clarinet

    OpenAIRE

    Meurisse, Thibaut; MAMOU-MANI, Adrien; Causse, René; Chomette, Baptiste; SHARP, David

    2014-01-01

    This paper reports a new approach to modifying the sound produced by a wind instrument. The approach is based on modal active control, which enables adjustment of the damping and the frequencies of the different resonances of a system. A self-sustained oscillating wind instrument can be modeled as an excitation source coupled to a resonator via a non-linear coupling. The aim of this study is to present simulations of modal active control applied to a modeled self-sustained oscillating wind in...

  18. Two fiber optics communication adapters apply to the control system of HIRFL-CSR

    International Nuclear Information System (INIS)

    The authors introduced two kinds of fiber adapters that apply to the engineering HIRFL-CSR. Including design of two adapters, operational principle, and hardware construction, field of application. How to control equipment which have the standard RS232 or RS485 interface at long distance by two adapters. Replace the RS485 bus with the fiber and the 485-Fiber Adapter, solved the problem of communication disturb. The requirements of control in the national great science engineering HIRFL-CSR are fulfilled. (authors)

  19. A composite controller for trajectory tracking applied to the Furuta pendulum.

    Science.gov (United States)

    Aguilar-Avelar, Carlos; Moreno-Valenzuela, Javier

    2015-07-01

    In this paper, a new composite scheme is proposed, where the total control action is composed of the sum of a feedback-linearization-based controller and an energy-based compensation. This new proposition is applied to the rotary inverted pendulum or Furuta pendulum. The Furuta pendulum is a well-known underactuated mechanical system with two degrees of freedom. The control objective in this case is the tracking of a desired periodic trajectory in the actuated joint, while the unactuated link is regulated at the upward position. The closed-loop system is analyzed showing uniformly ultimately boundedness of the error trajectories. The design procedure is shown in a constructive form, such that it may be applied to other underactuated mechanical systems, with the proper definitions of the output function and the energy function. Numerical simulations and real-time experiments show the practical viability of the controller. Finally, the proposed algorithm is compared with a tracking controller previously reported in the literature. The new algorithm shows better performance in both arm trajectory tracking and pendulum regulation. PMID:25792518

  20. Experimental Investigation on Adaptive Robust Controller Designs Applied to Constrained Manipulators

    Directory of Open Access Journals (Sweden)

    Marco H. Terra

    2013-04-01

    Full Text Available In this paper, two interlaced studies are presented. The first is directed to the design and construction of a dynamic 3D force/moment sensor. The device is applied to provide a feedback signal of forces and moments exerted by the robotic end-effector. This development has become an alternative solution to the existing multi-axis load cell based on static force and moment sensors. The second one shows an experimental investigation on the performance of four different adaptive nonlinear H∞ control methods applied to a constrained manipulator subject to uncertainties in the model and external disturbances. Coordinated position and force control is evaluated. Adaptive procedures are based on neural networks and fuzzy systems applied in two different modeling strategies. The first modeling strategy requires a well-known nominal model for the robot, so that the intelligent systems are applied only to estimate the effects of uncertainties, unmodeled dynamics and external disturbances. The second strategy considers that the robot model is completely unknown and, therefore, intelligent systems are used to estimate these dynamics. A comparative study is conducted based on experimental implementations performed with an actual planar manipulator and with the dynamic force sensor developed for this purpose.

  1. Quality Control Procedures Applied to the CMS Muon Chambers Built at CIEMAT

    International Nuclear Information System (INIS)

    In this document the quality control procedures applied to the CMS muon drift chambers built at CIEMAT are described. It includes a description of the high voltage and front electronics associated to the chambers. Every procedure is described with detail and a list of the more common problems and possible solutions is given. This document can be considered as a chamber test handbook for beginners. (Author) 3 refs

  2. Chance-constrained model predictive control applied to inventory management in hospitalary pharmacy

    OpenAIRE

    Maestre, Jose Maria; Ocampo-Martinez, Carlos

    2014-01-01

    This extended abstract addresses the preliminary results of applying uncertainty handling strategies and advanced control techniques to the inventary management of hospitality pharmacy. Inventory management is one of the main tasks that a pharmacy department has to carry out in a hospital. It is a complex problem because it requires to establish a tradeoff between contradictory optimization criteria. The final goal of the proposed research is to update the inventory management system of hospi...

  3. Pressure--temperature creep testing as applied to a commercial rock salt

    International Nuclear Information System (INIS)

    A triaxial compression apparatus was evaluated in its performance of quasi-static and creep experiments on rock salt under confining pressures to 5000 psi and temperatures to 2000C. Included is the capability to measure both axial and lateral (radial) deformation. Based on empirical data fits of the form epsilon = at/sup eta/, the observed 10 hour to 100 hour creep rates and the projected 1 year creep rates, epsilon1, were in the order of 10-6 to 10-8 s-1. For the most part the principal strain ratios, absolute value of epsilon3/epsilon1, or the ratio of the principal strain rates lay between .37 and .6 suggesting volume changes during creep which are relatively small compared with the changes in shear strain and shear strain rates. Beyond these general observations no specific trends could be identified concerning, for example, the effects of pressure, deviator stress and even temperature. This is due to gross data scatter on one hand and to insufficient number of data points for meaningful statistical analyses on the other

  4. Evaluation of a bias correction method applied to downscaled precipitation and temperature reanalysis data for the Rhine basin

    Directory of Open Access Journals (Sweden)

    W. Terink

    2010-01-01

    Full Text Available In many climate impact studies hydrological models are forced with meteorological data without an attempt to assess the quality of these data. The objective of this study is to compare downscaled ERA15 (ECMWF-reanalysis data precipitation and temperature with observed precipitation and temperature and apply a bias correction to these forcing variables. Precipitation is corrected by fitting the mean and coefficient of variation (CV of the observations. Temperature is corrected by fitting the mean and standard deviation of the observations. It appears that the uncorrected ERA15 is too warm and too wet for most of the Rhine basin. The bias correction leads to satisfactory results, precipitation and temperature differences decreased significantly, although there are a few years for which the correction of precipitation is less satisfying. Corrections were largest during summer for both precipitation and temperature, and for September and October for precipitation only. Besides the statistics the correction method was intended to correct for, it is also found to improve the correlations for the fraction of wet days and lag-1 autocorrelations between ERA15 and the observations. For the validation period temperature is corrected very well, but for precipitation the RMSE of the daily difference between modeled and observed precipitation has increased for the corrected situation. When taking random years for calibration, and the remaining years for validation, the spread in the mean bias error (MBE becomes larger for the corrected precipitation during validation, but the overal average MBE has decreased.

  5. Temperature controlled material irradiation in the advanced test reactor

    International Nuclear Information System (INIS)

    The Advanced Test Reactor (ATR) is located at the Idaho National Engineering Laboratory (INEL) near Idaho Falls, Idaho, USA and is owned and regulated by the U.S. Department of Energy (US DOE). The ATR is operated for the US DOE by Lockheed Martin Idaho Technologies. In recent years, prime irradiation space in the ATR has been made available for use by customers having irradiation service needs in addition to the reactor's principal user, the U.S. Naval Nuclear Propulsion Program. To enhance the reactor's capabilities, the US DOE has initiated the development of an Irradiation Test Vehicle (ITV) capable of providing neutron spectral tailoring and temperature control for up to 28 experiments. The ATR-ITV will have the flexibility to simultaneously support a variety of experiments requiring fast, thermal or mixed spectrum neutron environments. Temperature control is accomplished by varying the thermal conductivity across a gas gap established between the experiment specimen capsule wall and the experiment 'in-pile tube (IPT)' inside diameter. Thermal conductivity is adjusted by alternating the control gas mixture ratio of two gases with different thermal conductivities

  6. JUSTIFICATION OF TEMPERATURE CONTROL FOR PRODUCTION SUPPOSITORIES WITH GLIFAZIN

    Directory of Open Access Journals (Sweden)

    Dmitrievskiy D.I.

    2015-05-01

    Full Text Available The intensive search for new anti-diabetic drugs, carried out in the National pharmaceutical university in recent years led to the creation of complex drug "Glifazin" on base of which the composition and technology of suppositories with hypoglycemic effect were developed. Now comprehensive physicochemical and pharmacological study of the dosage form are going on. This paper presents results of determining the critical parameters of technology of suppositories witn Glifazin produced by molding - temperature control of homogenization and molding of suppository mass. This mode, as shown in the work, grounded on the analysis of rheological behavior of the system in the temperature range in which it is the transition from the liquid state of Newtonian type flow to the plastic-bound state of non- Newtonian flow type. This interval for suppository mass with Glifazin is in the range 45-60 ° C. Materials and methods. As the object of the study the suppositories with Glifazin 0.1 g and polietylenoxide base on which they are prepared were taken. The study of structural and mechanical (rheological properties of suppository base and suppository mass were performed on a rotary viscometer «Reotest-2" (Germany with coaxial cylinders and the temperature range 45-60 °C. Determination of hardening temperature, resistance of suppositories to decay and their dissolution time were measured by methods of the State Pharmacopoeia of Ukraine. Determination of uniformity suppository mass was assessed by quantitative content of Glifazin in selected samples by using UV spectrophotometry method at 271 nm against a standard sample of Onozid. Results and discussion. The analysis of rheogram shows that the suppository mass with Glifazin in the test temperature range has falseplastice type of flow. The presence of hysteresis loops indicates that this system has dispersed thixotropic properties. Thus, an increase in temperature leads to a decrease in the area of the hysteresis

  7. To the problem of electron temperature control in plasma

    International Nuclear Information System (INIS)

    One of the main problems in low temperature plasma is control plasma parameters at fixed values of current and gas pressure in the discharge. It is known that an increase in the intensity of sound wave directed along the positive column to values in excess of a definite threshold leads to essential rise of the temperature of electrons. However, no less important is the reduction of electron temperature in the discharge down to the value less than that in plasma in the absence external influence. It is known that to reduce the electron temperature in the plasma of CO2 laser, easily ionizable admixture are usually introduced in the discharge area with the view of increasing the overpopulation. In the present work we shall show that the value of electron temperature can be reduced by varying of sound wave intensity at its lower values. The experiment was performed on an experimental setup consisted of the tube with length 52 cm and diameter 9.8 cm, two electrodes placed at the distance of 27 cm from each other. An electrodynamical radiator of sound wave was fastened to one of tube ends. Fastened to the flange at the opposite end was a microphone for the control of sound wave parameters. The studies were performed in range of pressures from 40 to 180 Torr and discharge currents from 40 to 110 mA. The intensity of sound wave was varied from 74 to 92 dB. The measurement made at the first resonance frequency f = 150 Hz of sound in the discharge tube, at which a quarter of wave length keep within the length of the tube. The measurement of longitudinal electric field voltage in plasma of positive column was conducted with the help of two probes according to the compensation method. Besides, the measurement of gas temperature in the discharge were taken. Two thermocouple sensors were arranged at the distance of 8 cm from the anode, one of them being installed on the discharge tube axis, the second-fixed the tube wall

  8. Thermal Management Controller for Heat Source Temperature Control and Thermal Management

    Institute of Scientific and Technical Information of China (English)

    HUANGFU Yi; WU Jing-yi; WANG Ru-zhu; LI Sheng

    2009-01-01

    In many heat recovery processes, temperature control of heat source is often required to ensure safety and high efficiency of the heat source equipment. In addition, the management of recovered heat is important for the proper use of waste heat. To this aim, the concept of thermal management controller (TMC), which can vary heat transfer rate via the volume variation of non-condensable gas, was presented. Theoretical model and experimental prototype were established. Investigation shows that the prototype is effective in temperature control. With water as the working fluid, the vapor temperature variation is only 1.3 ℃ when the heating power varies from 2.5 to 10.0 kW. In variable working conditions, this TMC can automatically adjust thermal allocation to the heat consumer.

  9. Magnetic control of large room-temperature polarization

    International Nuclear Information System (INIS)

    Numerous authors have referred to room-temperature magnetic switching of large electric polarizations as 'the Holy Grail' of magnetoelectricity. We report this long-sought effect, obtained using a new physical process of coupling between magnetic and ferroelectric nanoregions. Solid state solutions of PFW [Pb(Fe2/3W1/3)O3] and PZT [Pb(Zr0.53Ti0.47)O3] exhibit some bi-relaxor qualities, with both ferroelectric relaxor characteristics and magnetic relaxor phenomena. Near 20% PFW the ferroelectric relaxor state is nearly unstable at room temperature against long-range ferroelectricity. Here we report magnetic switching between the normal ferroelectric state and a magnetically quenched ferroelectric state that resembles relaxors. This gives both a new room-temperature, single-phase, multiferroic magnetoelectric, (PbFe0.67W0.33O3)0.2(PbZr0.53Ti0.47O3)0.8 ('0.2PFW/0.8PZT'), with polarization, loss (8-109 Ω cm) equal to or superior to those of BiFeO3, and also a new and very large magnetoelectric effect: switching not from +Pr to -Pr with applied H, but from Pr to zero with applied H of less than a tesla. This switching of the polarization occurs not because of a conventional magnetically induced phase transition, but because of dynamic effects: increasing H lengthens the relaxation time by 500 x from100 μs, and it strongly couples the polarization relaxation and spin relaxations. The diverging polarization relaxation time accurately fits a modified Vogel-Fulcher equation in which the freezing temperature Tf is replaced by a critical freezing field Hf that is 0.92 ± 0.07 T. This field dependence and the critical field Hc are derived analytically from the spherical random bond random field model with no adjustable parameters and an E2H2 coupling. This device permits three-state logic (+Pr,0,-Pr) and a condenser with >5000% magnetic field change in its capacitance; for H = 0 the coercive voltage is 1.4 V across 300 nm for +Pr to -Pr switching, and the coercive magnetic

  10. Temperature compensation method for the resonant frequency of a differential vibrating accelerometer using electrostatic stiffness control

    International Nuclear Information System (INIS)

    Differential vibrating accelerometer (DVA) is a resonant-type sensor which detects the change in the resonant frequency in the presence of acceleration input, i.e. inertial loading. However, the resonant frequency of micromachined silicon resonators is sensitive to the temperature change as well as the input acceleration. Therefore, to design a high-precision vibrating accelerometer, the temperature sensitivity of the resonant frequency has to be predicted and compensated accurately. In this study, a temperature compensation method for resonant frequency is proposed which controls the electrostatic stiffness of the dual-ended tuning fork (DETF) using the temperature-dependent dc voltage between the parallel plate electrodes. To do this, the electromechanical model is derived first to predict the change in the electrostatic stiffness and the resonant frequency resulting from the dc voltage between the resonator and the electrodes. Next, the temperature sensitivity of the resonant frequency is modeled, estimated and compared with the measured values. Then it is shown that the resonant frequency of the DETF can be kept constant in the operating temperature range by applying the temperature-dependent driving voltage to the parallel plate electrodes. The proposed method is validated through experiment. (paper)

  11. Temperature compensation method for the resonant frequency of a differential vibrating accelerometer using electrostatic stiffness control

    Science.gov (United States)

    Lee, Jungshin; Rhim, Jaewook

    2012-09-01

    Differential vibrating accelerometer (DVA) is a resonant-type sensor which detects the change in the resonant frequency in the presence of acceleration input, i.e. inertial loading. However, the resonant frequency of micromachined silicon resonators is sensitive to the temperature change as well as the input acceleration. Therefore, to design a high-precision vibrating accelerometer, the temperature sensitivity of the resonant frequency has to be predicted and compensated accurately. In this study, a temperature compensation method for resonant frequency is proposed which controls the electrostatic stiffness of the dual-ended tuning fork (DETF) using the temperature-dependent dc voltage between the parallel plate electrodes. To do this, the electromechanical model is derived first to predict the change in the electrostatic stiffness and the resonant frequency resulting from the dc voltage between the resonator and the electrodes. Next, the temperature sensitivity of the resonant frequency is modeled, estimated and compared with the measured values. Then it is shown that the resonant frequency of the DETF can be kept constant in the operating temperature range by applying the temperature-dependent driving voltage to the parallel plate electrodes. The proposed method is validated through experiment.

  12. Radial oil injection applied to main engine bearings: evaluation of injection control rules

    DEFF Research Database (Denmark)

    Estupiñan, EA; Santos, Ilmar

    2012-01-01

    The performance of main bearings in a combustion engine affects key functions such as durability, noise and vibration. Thus, with the aim of reducing friction losses and vibrations between the crankshaft and the bearings, the work reported here evaluates different strategies for applying controll...... actively lubricated bearing is compared with the performance of the conventional lubricated bearing, giving some insights into the minimum fluid film thickness, maximum fluid film pressure, friction losses and maximum vibration levels....... controllable radial oil injection to main crankshaft journal bearings. In an actively lubricated bearing, conventional hydrodynamic lubrication is combined with controllable hydrostatic lubrication, where the oil injection pressures can be modified depending on the operational conditions. In this study, the...

  13. Active lubrication applied to internal combustion engines - evaluation of control strategies

    DEFF Research Database (Denmark)

    Estupinan, Edgar Alberto; Santos, Ilmar

    2009-01-01

    The performance of fluid film bearings in a combustion engine affects key functions such as durability, noise and vibration. Therefore, this work evaluates different control strategies for applying active radial oil injection in the main bearings of internal combustion engines with the aim of...... reducing friction losses and vibrations between the crankshaft and the bearings. The conventional hydrodynamic lubrication is combined with hydrostatic lubrication which is actively modified by radially injecting oil at controllable pressures, through orifices circumferentially located around the bearing...... surface. The behaviour of a main bearing of a medium size combustion engine, operating with radial oil injection and with four different control strategies is analyzed, giving some insights into the minimum fluid film thickness, maximum fluid film pressure, friction losses and maximum vibration levels...

  14. A numerical comparison of control strategies applied to an existing ice storage system

    International Nuclear Information System (INIS)

    While ice storage systems are designed according to a defined strategy for warm day loads, it is interesting to consider other conventional control strategies for mid-season day loads. Three different charging-discharging control strategies are applied to an existing cooling plant and compared in terms of operating costs and energy consumption. A cooling plant model is built. A time stage equal to 15 min is considered to simulate numerically a whole charging-discharging process and compare the different control strategies. These simulations take into account existing technical constraints and set points. EES software is used. The operating costs of the cooling plant are evaluated by taking into account both the energy and the demand cost rate. It is shown that an ice storage system can allow savings of operating costs. However, they can increase energy consumption

  15. Quantitative Feedback Theory (QFT) applied to the design of a rotorcraft flight control system

    Science.gov (United States)

    Hess, R. A.; Gorder, P. J.

    1992-01-01

    Quantitative Feedback Theory describes a frequency-domain technique for the design of multi-input, multi-output control systems which meet time or frequency domain performance criteria when specified uncertainty exists in the linear description of the vehicle dynamics. Quantitative Feedback Theory is applied to the design of the longitudinal flight control system for a linear uncertain model of the AH-64 rotorcraft. In this model, the uncertainty is assigned, and is assumed to be attributable to actual uncertainty in the dynamic model and to the changes in the vehicle aerodynamic characteristics which occur near hover. The model includes an approximation to the rotor and actuator dynamics. The design example indicates the manner in which handling qualities criteria may be incorporated into the design of realistic rotorcraft control systems in which significant uncertainty exists in the vehicle model.

  16. Field tests applying multi-agent technology for distributed control. Virtual power plants and wind energy

    International Nuclear Information System (INIS)

    Multi-agent technology is state of the art ICT. It is not yet widely applied in power control systems. However, it has a large potential for bottom-up, distributed control of a network with large-scale renewable energy sources (RES) and distributed energy resources (DER) in future power systems. At least two major European R and D projects (MicroGrids and CRISP) have investigated its potential. Both grid-related as well as market-related applications have been studied. This paper will focus on two field tests, performed in the Netherlands, applying multi-agent control by means of the PowerMatcher concept. The first field test focuses on the application of multi-agent technology in a commercial setting, i.e. by reducing the need for balancing power in the case of intermittent energy sources, such as wind energy. In this case the flexibility is used of demand and supply of industrial and residential consumers and producers. Imbalance reduction rates of over 40% have been achieved applying the PowerMatcher, and with a proper portfolio even larger rates are expected. In the second field test the multi-agent technology is used in the design and implementation of a virtual power plant (VPP). This VPP digitally connects a number of micro-CHP units, installed in residential dwellings, into a cluster that is controlled to reduce the local peak demand of the common low-voltage grid segment the micro-CHP units are connected to. In this way the VPP supports the local distribution system operator (DSO) to defer reinforcements in the grid infrastructure (substations and cables)

  17. EBR-II secondary sodium loop Plugging Temperature Indicator control system upgrade

    International Nuclear Information System (INIS)

    The Experimental Breeder Reactor II (EBR-II) secondary sodium coolant loop Plugging Temperature Indicator (PTI) control system was upgraded in 1993 to a real-time computer based system. This was done to improve control, to remove obsolete and high maintenance equipment, and to provide a graphical CRT based operator interface. A goal was to accomplish this inexpensively using small, reliable computer and display hardware with a minimum of purchased software. This paper describes the PTI system, the upgraded control system and its operator interface, and development methods and tools. The paper then assesses how well the system met its goals, discusses lessons learned and operational improvements noted, and provides some recommendations and suggestions on applying small real-time control systems of this type

  18. Temperature Field-Wind Velocity Field Optimum Control of Greenhouse Environment Based on CFD Model

    Directory of Open Access Journals (Sweden)

    Yongbo Li

    2014-01-01

    Full Text Available The computational fluid dynamics technology is applied as the environmental control model, which can include the greenhouse space. Basic environmental factors are set to be the control objects, the field information is achieved via the division of layers by height, and numerical characteristics of each layer are used to describe the field information. Under the natural ventilation condition, real-time requirements, energy consumption, and distribution difference are selected as index functions. The optimization algorithm of adaptive simulated annealing is used to obtain optimal control outputs. A comparison with full-open ventilation shows that the whole index can be reduced at 44.21% and found that a certain mutual exclusiveness exists between the temperature and velocity field in the optimal course. All the results indicate that the application of CFD model has great advantages to improve the control accuracy of greenhouse.

  19. Fiber-Optic Temperature and Pressure Sensors Applied to Radiofrequency Thermal Ablation in Liver Phantom: Methodology and Experimental Measurements

    Directory of Open Access Journals (Sweden)

    Daniele Tosi

    2015-01-01

    Full Text Available Radiofrequency thermal ablation (RFA is a procedure aimed at interventional cancer care and is applied to the treatment of small- and midsize tumors in lung, kidney, liver, and other tissues. RFA generates a selective high-temperature field in the tissue; temperature values and their persistency are directly related to the mortality rate of tumor cells. Temperature measurement in up to 3–5 points, using electrical thermocouples, belongs to the present clinical practice of RFA and is the foundation of a physical model of the ablation process. Fiber-optic sensors allow extending the detection of biophysical parameters to a vast plurality of sensing points, using miniature and noninvasive technologies that do not alter the RFA pattern. This work addresses the methodology for optical measurement of temperature distribution and pressure using four different fiber-optic technologies: fiber Bragg gratings (FBGs, linearly chirped FBGs (LCFBGs, Rayleigh scattering-based distributed temperature system (DTS, and extrinsic Fabry-Perot interferometry (EFPI. For each instrument, methodology for ex vivo sensing, as well as experimental results, is reported, leading to the application of fiber-optic technologies in vivo. The possibility of using a fiber-optic sensor network, in conjunction with a suitable ablation device, can enable smart ablation procedure whereas ablation parameters are dynamically changed.

  20. Temperature control and cracking prevention in coastal thin-wall concrete structures

    Directory of Open Access Journals (Sweden)

    Li-xia GUO

    2011-12-01

    Full Text Available A three-dimensional finite element program for thermal analysis of hydration heat in concrete structures with a plastic pipe cooling system is introduced in this paper. The program was applied to simulation of the temperature and stress field of the Cao’e Sluice during the construction period. From the calculated results, we can find that the temperature and stress of concrete cooled with plastic pipes are much lower than those of concrete without pipes. Moreover, plastic pipes could not be corroded by seawater. That is to say, a good effect of temperature control and cracking prevention can be achieved, which provides a useful reference for other similar nearshore concrete projects.

  1. Application of Improved Neural Adaptive PSD Algorithm in Temperature Control of INS

    Institute of Scientific and Technical Information of China (English)

    缪玲娟; 郭振西; 崔燕

    2004-01-01

    A neural adaptive proportion sum differential (PSD) algorithm with errors prediction is researched. It is applied in inertial navigation system(INS) temperature control. The algorithm do not need the process's precise mathematical model and can adapt to the process pareters changing, and can deal with the process with nonlinearity. According to the Smith predictor, author developed a method that takes the predicted process error and error change as neural adaptive PSD algorithm's input. The method is effective to the system with long dead time. The results of compute simulation show that this system has characters of quickly reaction, low overshoot and good stability. It can meet the requirements of temperature control of INS.

  2. [Effects of applying controlled-release fertilizer and its combination with urea on nitrous oxide emission during rice growth period].

    Science.gov (United States)

    Ji, Yang; Zhang, Xiao-Yan; Ma, Jing; Li, Xiao-ping; Xu, Hua; Cai, Zu-cong

    2011-08-01

    By the method of static chamber, a field experiment was conducted to study the effects of applying controlled-release fertilizer (CRF) and its combination with urea on the N2O emission during rice growth period. Four treatments, i.e., no fertilization (CK), urea (U), urea and CRF with a ratio of 3:7 (U+C), and CRF (C) were installed, and the N application rate in treatments U, U+C, and C was the same. Compared with treatment U, treatments U+C and C decreased the N2O emission during rice growth season by 40.4% and 59.6%, and decreased the emission at midseason aeration stage by 65.1% and 83.9%, respectively (P < 0.05). Compared with that in treatment C, the N2O emission in treatment U+C had a slight decrease, and decreased by 53.9% at midseason aeration stage. Applying CRF increased rice yield, and the increment in treatments C and U+C was 7.8% and 9.8%, respectively, as compared to treatment U. Applying CRF delayed the peak time of soil inorganic nitrogen concentration, resulting in the reduction of N2O emission at midseason aeration stage. During rice growth season, no significant correlation was observed between N2O flux and soil Eh or soil temperature. PMID:22097364

  3. Ammonia Volatilization from Urea Applied to Acid Paddy Soil in Southern China and Its Control

    Institute of Scientific and Technical Information of China (English)

    CAIGUI-XIN; PENGGUANG-HAO; 等

    1992-01-01

    Results showed that ammonia loss from urea broadcast into floodwater and incorporated into soil at transplanting was as high as 40% of applied N,and the corresponding total nitrogen (N) loss was 56%.Ammonia loss was measured with simplified micrometeorological method (ammonia sampler),and total N loss was concurrently measured using 15N balance technique.The experiment was conducted under strong sunshine conditions on acid paddy soil derived from Quaternary red clay.The ammonia loss in this particular condition was much greater than those obtained from previous studies when urea was also applied to acid paddy soil but under cloudy conditions.It is concluded that the strong sunshine conditions with high temperature and shallow floodwater during the period of present experiment favoured ammonia volatilization.Application of stearyl alcohol on the surface of the floodwater reduced ammonia loss to 23% of applied N.However,the effect of stearyl alcohol was short-lived,probably due to the microbiological decomposition.

  4. Budget-limited thermal biology: Design, construction and performance of a large, walk-in style temperature-controlled chamber.

    Science.gov (United States)

    Martinez, Eloy; Agosta, Salvatore J

    2016-05-01

    We describe a partial redesign of the conventional air-conditioning system and apply it to the construction of a relatively large (1.87m(3) air mass), walk-in style temperature-controlled chamber (TCC) using parts easily obtained in most countries. We conducted several tests to demonstrate the performance of the TCC. Across the physiologically relevant range of 5-37°C, the TCC took 26.5-50.0min to reach the desired set point temperature. Once at set point, temperature inside the chamber was controlled with an accuracy of ±1.0°C. User-entry effects on deviations from and return times to set point temperature were minimal. Overall, performance of the TCC was sufficient to make precise physiological measurements of insect metabolic rate while controlling assay temperature. Major advantages of the TCC include its simplicity, flexibility, and low cost. PMID:27157331

  5. Tissue temperatures and lesion size during irrigated tip catheter radiofrequency ablation: an in vitro comparison of temperature-controlled irrigated tip ablation, power-controlled irrigated tip ablation, and standard temperature-controlled ablation

    DEFF Research Database (Denmark)

    Petersen, H H; Chen, X; Pietersen, A;

    2000-01-01

    The limited success rate of radiofrequency catheter ablation in patients with ventricular tachycardias related to structural heart disease may be increased by enlarging the lesion size. Irrigated tip catheter ablation is a new method for enlarging the size of the lesion. It was introduced in the...... power-controlled mode with high power and high infusion rate, and is associated with an increased risk of crater formation, which is related to high tissue temperatures. The present study explored the tissue temperatures during temperature-controlled irrigated tip ablation, comparing it with standard...... temperature-controlled ablation and power-controlled irrigated tip ablation. In vitro strips of porcine left ventricular myocardium were ablated. Temperature-controlled irrigated tip ablation at target temperatures 60 degrees C, 70 degrees C, and 80 degrees C with infusion of 1 mL saline/min were compared...

  6. Evaluating geothermal and hydrogeologic controls on regional groundwater temperature distribution

    Science.gov (United States)

    Burns, Erick R.; Ingebritsen, Steven E.; Manga, Michael; Williams, Colin F.

    2016-02-01

    A one-dimensional (1-D) analytic solution is developed for heat transport through an aquifer system where the vertical temperature profile in the aquifer is nearly uniform. The general anisotropic form of the viscous heat generation term is developed for use in groundwater flow simulations. The 1-D solution is extended to more complex geometries by solving the equation for piece-wise linear or uniform properties and boundary conditions. A moderately complex example, the Eastern Snake River Plain (ESRP), is analyzed to demonstrate the use of the analytic solution for identifying important physical processes. For example, it is shown that viscous heating is variably important and that heat conduction to the land surface is a primary control on the distribution of aquifer and spring temperatures. Use of published values for all aquifer and thermal properties results in a reasonable match between simulated and measured groundwater temperatures over most of the 300 km length of the ESRP, except for geothermal heat flow into the base of the aquifer within 20 km of the Yellowstone hotspot. Previous basal heat flow measurements (˜110 mW/m2) made beneath the ESRP aquifer were collected at distances of >50 km from the Yellowstone Plateau, but a higher basal heat flow of 150 mW/m2 is required to match groundwater temperatures near the Plateau. The ESRP example demonstrates how the new tool can be used during preliminary analysis of a groundwater system, allowing efficient identification of the important physical processes that must be represented during more-complex 2-D and 3-D simulations of combined groundwater and heat flow.

  7. Field test of infrared thermography applied to biogas controlling in landfill sites

    Science.gov (United States)

    Madruga, Francisco J.; Muñoz, Jaime M.; González, Daniel A.; Tejero, Juan I.; Cobo, Adolfo; Gil, José L.; Conde, Olga M.; López-Higuera, Jose M.

    2007-04-01

    The gases accumulated inside the landfill as result of the fermentation of Municipal Solid Waste (MSW) known as biogas, are taking into consideration all possible uses as direct transformation into electricity. The system for collecting, regulating and controlling the biogas must include all the necessary safety features where the biogas leakage presents a high impact. Infrared thermography can be use to detect gas leakages due to the differences in temperature between the gas and the immediate surroundings. This method is able to monitor a wide area of landfill sites, quickly. This technology will not be effective if the differences in temperature are not better than five degrees. This paper describes a field test conducted to study the limitations of the infrared thermography caused by weather conditions and the moment of day or/and season when the thermal images was captured. Pipelines, borders, cells, covers, slopes and leakage (hot spots) are studied and optimum conditions are defined.

  8. Robust design of reactor power control system with genetic algorithm-applied weighting functions

    International Nuclear Information System (INIS)

    The H∞ algorithms of the mixed weight sensitivity is used for the robust design of the reactor power control system. The mixed weight sensitivity method requires the selection of the proper weighting functions for the loop shaping in frequency domain. The complexity of the system equation and the non-convexity of the problem make it very difficult to determine the weighting functions. The genetic algorithm which is improved and hybridized with the simulated annealing is applied to determine the weighting functions. This approach permits an automatic calculation and the resultant system shows good robustness and performance. (author)

  9. Implementation of a Fuzzy Logic System to Tune a PI Controller Applied to an Induction Motor

    Directory of Open Access Journals (Sweden)

    LAROUSSI, K.

    2009-10-01

    Full Text Available The simplicity of traditional regulators makes them popular and the most used solution in the nowadays industry. However, they suffer from some limitations and cannot deal with nonlinear dynamics and system parameters variation. In the literature, several strategies of adaptation are developed to alleviate these limitations. In this paper, we propose a combination of two strategies for PI parameters supervision and adaptation. We apply the obtained structure to the control of induction machine speed. Simulation and experimental results of the proposed schema show good performances as compared to two strategies.

  10. New tuning formulae for the PI controller applied to processes with integral actions

    Directory of Open Access Journals (Sweden)

    Tomislav B. Šekara

    2013-02-01

    Full Text Available A new model Gm(s, defined by the four measurable parameters ultimate gain, ultimate frequency, amplitude of ultimate oscillation and dead-time, is obtained from tangent to the Nyquist curve at the critical point. This model represents the generalization of the Ziegler-Nichols process dynamics characterization method, for a large class of stable, integrating and unstable processes Gp(s. In the present paper, by applying time and amplitude scaling technique to the model Gm(s, a new tuning formulae are developed for the PI controller. These tuning formulae guarantee almost optimal performance/robustness tradeoff for a large class of processes with integral action.

  11. The fiber optics router apply to the control system of HIRFL-CSR

    International Nuclear Information System (INIS)

    The authors introduced a kind of Fiber Optic Router that we had designed specially applies to the engineering HIRFL-CSR (Heavy Ion Research Facility in Lanzhou). Including design principle, operational principle, and hardware construction, field of application. The router has standard communication interface such as RS232, RS485, Ethernet and Optics; setup of an optical communication network is simplified. It solved problems such as communication disturb. The requirements of control in the national great science engineering HIRFL-CSR are fulfilled. (authors)

  12. Classical linear-control analysis applied to business-cycle dynamics and stability

    Science.gov (United States)

    Wingrove, R. C.

    1983-01-01

    Linear control analysis is applied as an aid in understanding the fluctuations of business cycles in the past, and to examine monetary policies that might improve stabilization. The analysis shows how different policies change the frequency and damping of the economic system dynamics, and how they modify the amplitude of the fluctuations that are caused by random disturbances. Examples are used to show how policy feedbacks and policy lags can be incorporated, and how different monetary strategies for stabilization can be analytically compared. Representative numerical results are used to illustrate the main points.

  13. Development of neural network driven fuzzy controller for outlet sodium temperature of DHX

    International Nuclear Information System (INIS)

    Fuzzy controls are capable to exquisitely control non-linear dynamic systems in wide operating range, using linguistic description to define the control law. However the selection and the definition of the fuzzy rules and sets require a tedious trial and error process based on experience. As a method to overcome this limitation, a neural network driven fuzzy control (NDF), where the learning capability of the neural network (NN) is used to build the fuzzy rules and sets, is presented in this paper. In the NDF control the IF part of a fuzzy control is represented by a multilayer NN while the THEN part is represented by a series of multilayer NNs which calculate the desirable control action. In this work the usual stepwise variable reduction method, used for the selection of the input variable in the THEN part NN, is replaced with a learning algorithm with forgetting mechanism that realizes the automatic reduction of the variables and the tuning up of all the fuzzy control law i.e. the membership function. The NDF has been successfully applied to control the outlet sodium temperature of a dump heat exchanger (DHX) of a FBR plant

  14. Voltage controlled inversion of magnetic anisotropy in a ferromagnetic thin film at room temperature

    International Nuclear Information System (INIS)

    The control of magnetic properties by means of an electric field is an important aspect in magnetism and magnetoelectronics. We here utilize magnetoelastic coupling in ferromagnetic/piezoelectric hybrids to realize a voltage control of magnetization orientation at room temperature. The samples consist of polycrystalline nickel thin films evaporated onto piezoelectric actuators. The magnetic properties of these multifunctional hybrids are investigated at room temperature as a function of the voltage controlled stress exerted by the actuator on the Ni film. Ferromagnetic resonance spectroscopy shows that the magnetic easy axis in the Ni film plane is rotated by 90 deg. upon changing the polarity of the voltage Vp applied to the actuator. In other words, the in-plane uniaxial magnetic anisotropy of the Ni film can be inverted via the application of an appropriate voltage Vp. Using superconducting quantum interference device (SQUID) magnetometry, the evolution of the magnetization vector is recorded as a function of Vp and of the external magnetic field. Changing Vp allows to reversibly adjust the magnetization orientation in the Ni film plane within a range of approximately 70 deg. All magnetometry data can be quantitatively understood in terms of the magnetic free energy determined from the ferromagnetic resonance experiments. These results demonstrate that magnetoelastic coupling in hybrid structures is indeed a viable option to control magnetization orientation in technologically relevant ferromagnetic thin films at room temperature.

  15. High temperature glass thermal control structure and coating. [for application to spacecraft reusable heat shielding

    Science.gov (United States)

    Stewart, D. A.; Goldstein, H. E.; Leiser, D. B. (Inventor)

    1983-01-01

    A high temperature stable and solar radiation stable thermal control coating is described which is useful either as such, applied directly to a member to be protected, or applied as a coating on a re-usable surface insulation (RSI). It has a base coat layer and an overlay glass layer. The base coat layer has a high emittance, and the overlay layer is formed from discrete, but sintered together glass particles to give the overlay layer a high scattering coefficient. The resulting two-layer space and thermal control coating has an absorptivity-to-emissivity ratio of less than or equal to 0.4 at room temperature, with an emittance of 0.8 at 1200 F. It is capable of exposure to either solar radiation or temperatures as high as 2000 F without significant degradation. When used as a coating on a silica substrate to give an RSI structure, the coatings of this invention show significantly less reduction in emittance after long term convective heating and less residual strain than prior art coatings for RSI structures.

  16. A Change Oriented Extension of EOF Analysis Applied to the 1996-1997 AVHRR Sea Surface Temperature Data

    DEFF Research Database (Denmark)

    Nielsen, Allan Aasbjerg; Conradsen, Knut; Andersen, Ole Baltazar

    2002-01-01

    This paper describes the application of orthogonal transformations to detect multivariate change in the monthly mean sea surface temperature (SST) as given by the NOAA/NASA Oceans Pathfinder data. The transforms applied include multivariate alteration detection (MAD) variates based on canonical...... correlation analysis, and maximum autocorrelation factors (MAFs). The method described can be considered as an extension to EOF analysis that is specially tailored for change detection in spatial data since it first maximises differences in the data between two points in time and then maximises...

  17. An evaluation of extreme temperature events in Spain based on process control charts

    Science.gov (United States)

    Villeta, Maria; Valencia, Jose Luis; Saa, Antonio; Tarquis, Ana Maria

    2014-05-01

    In recent decades, extreme climate events have attracted the attention of growing number of researchers due to the fact these events cause large costs in agriculture and its insurance planning associated. This work focuses in extreme temperature events in concrete, and offers an analysis of them based on statistical process control tools, which are unusual in climate studios. Throughout this work we have evaluated the maximum and minimum temperatures for geographical areas of a Spanish region over a period from last century, in order to test statistically whether there is evidence of an increase of extreme temperature events, by applying methods of statistical process control. To this end, the temperature series have been seasonally adjusted. The analysis was performed on the anomalies temperatures series. For each of the geographic areas under study, statistical control charts for attributes were obtained for both maximum and minimum annual anomalies. Once the specification limits have been determined, they have been used for classifying observations as extreme or normal. This allows drawing a general assessment of the tendencies of extreme temperature events in the analyzed region. It can be concluded that there are three different cycles in maximum annual temperatures in all geographical areas analyzed: a first cycle, in which the proportion of extremes temperature days remain stable; a second period in which the proportion of the extremes days fallen slightly from the early years of the series; and a third stage, in which the proportion of days with extreme high temperatures increases significantly with respect to that observed in previous periods. With respect to minimum extreme annual temperatures in the Spanish region evaluated, another three cycles can be observed in all geographical areas: a first cycle from the start of the series, in which the proportion of extreme minimum temperature days remains stable; a second cycle in which the proportion of extreme

  18. Seawater temperature and salinity controls on Li/Ca ratios in Mytilus edulis (bivalvia) shells

    Science.gov (United States)

    Clarke, L. J.; Wanamaker, A. D., Jr.; Kreutz, K. J.; Borns, H. W., Jr.; Introne, D. S.

    2009-04-01

    In this study we have investigated the effects of seawater temperature and salinity on Li/Ca ratios in newly precipitated shell calcite in Mytilus edulis shells, since this potential temperature proxy has not been widely applied beyond brachiopods and inorganic calcite. Juvenile specimens of M. edulis collected from western Greenland were cultured in laboratory aquaria using a four-by-three factorial design that consisted of four circulating temperature baths and three salinities. New shell growth precipitated during the constrained culturing experiment was identified carefully and subsequently dissected from the shells. Following acid dissolution, Li/Ca ratios were measured by ICP-MS, enabling an assessment of temperature and salinity controls on shell Li/Ca ratios. Furthermore, measurement of Li/Ca ratios in the aquaria seawaters has enabled calculation of Li/Ca ratio partition coefficients and direct comparison to Li/Ca ratio to temperature relationships observed for brachiopods and inorganic calcite. The results of this study suggest that bivalve shell Li/Ca ratios can be used as a new temperature proxy.

  19. Optimal control theory (OWEM) applied to a helicopter in the hover and approach phase

    Science.gov (United States)

    Born, G. J.; Kai, T.

    1975-01-01

    A major difficulty in the practical application of linear-quadratic regulator theory is how to choose the weighting matrices in quadratic cost functions. The control system design with optimal weighting matrices was applied to a helicopter in the hover and approach phase. The weighting matrices were calculated to extremize the closed loop total system damping subject to constraints on the determinants. The extremization is really a minimization of the effects of disturbances, and interpreted as a compromise between the generalized system accuracy and the generalized system response speed. The trade-off between the accuracy and the response speed is adjusted by a single parameter, the ratio of determinants. By this approach an objective measure can be obtained for the design of a control system. The measure is to be determined by the system requirements.

  20. Linear and Non-Linear Control Techniques Applied to Actively Lubricated Journal Bearings

    DEFF Research Database (Denmark)

    Nicoletti, Rodrigo; Santos, Ilmar

    2003-01-01

    The main objectives of actively lubricated bearings are the simultaneous reduction of wear and vibration between rotating and stationary machinery parts. For reducing wear and dissipating vibration energy until certain limits, one can count with the conventional hydrodynamic lubrication. For...... further reduction of shaft vibrations one can count with the active lubrication action, which is based on injecting pressurised oil into the bearing gap through orifices machined in the bearing sliding surface. The design and efficiency of some linear (PD, PI and PID) and non-linear controllers, applied...... to a tilting-pad journal bearing, are analysed and discussed. Important conclusions about the application of integral controllers, responsible for changing the rotor-bearing equilibrium position and consequently the "passive" oil film damping coefficients, are achieved. Numerical results show an...

  1. Linear and Non-Linear Control Techniques Applied to Actively Lubricated Journal Bearings

    DEFF Research Database (Denmark)

    Nicoletti, Rodrigo; Santos, Ilmar

    2003-01-01

    The main objectives of actively lubricated bearings are the simultaneous reduction of wear and vibration between rotating and stationary machinery parts. For reducing wear and dissipating vibration energy until certain limits, one can count with the conventional hydrodynamic lubrication....... For further reduction of shaft vibrations one can count with the active lubrication action, which is based on injecting pressurised oil into the bearing gap through orifices machined in the bearing sliding surface. The design and efficiency of some linear (PD, PI and PID) and non-linear controllers, applied...... vibration reduction of unbalance response of a rigid rotor, where the PD and the non-linear P controllers show better performance for the frequency range of study (0 to 80 Hz). The feasibility of eliminating rotor-bearing instabilities (phenomena of whirl) by using active lubrication is also investigated...

  2. Color control of electrochemiluminescence based on duty ratio of applied waveform voltage

    Science.gov (United States)

    Nishimura, Ryoichi; Nihei, Eisuke

    2016-04-01

    In this research, we succeeded in controlling the light-emitting color obtained from the light-emitting surface of an organic electrochemiluminescence (ECL) device with a duty ratio of the applied voltage. The color change was based on the absorption of light by the light-emitting layer. Because we were able to control the light-emitting relative quantities in each electrode by changing the duty ratio. Long light-emitting lifetime will be expected in the future, because the light-emitting material used was poly(3-hexylthiophene-2,5-diyl) (P3HT), a conductive polymer. We fabricated the ECL device with a light-emitting layer thickness of 25.0 µm. In this device, the ECL color was changed from orange to red by changing the duty ratio from 50 to 10%. More ECL colors are expected to be realized by selecting the light-emitting material with appropriate absorption and ECL spectra.

  3. System for studies of control strategies applied in the refrigerated chambers Sistema para estudos de estratégias de controle aplicadas em câmaras frias

    Directory of Open Access Journals (Sweden)

    Alexandre Tizzei

    2011-10-01

    Full Text Available The process of cold storage chambers contributes largely to the quality and longevity of stored products. In recent years, it has been intensified the study of control strategies in order to decrease the temperature change inside the storage chamber and to reduce the electric power consumption. This study has developed a system for data acquisition and process control, in LabVIEW language, to be applied in the cooling system of a refrigerating chamber of 30m³. The use of instrumentation and the application developed fostered the development of scientific experiments, which aimed to study the dynamic behavior of the refrigeration system, compare the performance of control strategies and the heat engine, even due to the controlled temperature, or to the electricity consumption. This system tested the strategies for on-off control, PID and fuzzy. Regarding power consumption, the fuzzy controller showed the best result, saving 10% when compared with other tested strategies.O processo de armazenamento refrigerado em câmaras contribui, em grande parte, para a qualidade e a longevidade dos produtos. Nos últimos anos, têm-se intensificado os estudos de estratégias de controle com a finalidade de diminuir a variação da temperatura dentro da câmara de armazenamento e de reduzir o consumo de energia elétrica. Neste trabalho, foi desenvolvido um sistema para aquisição de dados e controle do processo, em linguagem LabVIEW, para ser aplicado no sistema de refrigeração de uma câmara frigorífica de 30m³. A utilização da instrumentação e do aplicativo desenvolvido possibilitou a realização de experimentos científicos, com o objetivo de estudar o comportamento dinâmico do sistema de refrigeração, comparar o desempenho das estratégias de controle da máquina térmica, tanto em função da temperatura controlada, quanto ao consumo de energia elétrica. Neste sistema, foram testadas as estratégias de controle liga-desliga, PID e fuzzy. Em

  4. Thermal control systems for low temperature Shuttle payloads

    Science.gov (United States)

    Wright, J. P.; Trucks, H.

    1976-01-01

    Greater sensitivity and longer life for future space sensor systems place more stringent demands on cooling system technology. Results are presented for a study designed to determine and evaluate low-temperature thermal control system concepts for various cooling categories in the range 3-200 K and to generate hardware development plans for undeveloped viable system concepts. The study considered Shuttle launched payloads in the 1980-1991 time frame, with 1-5 yr of life. Cooling concepts are categorized as open-cycle (expendable), closed-cycle (mechanical), solid-state, and radiative. Particular attention is given to the concepts of multistage heat pipe radiator, diode heat pipe radiator, and radiator guarded cryostat. Results are given for parametric analyses of the Vuilleumier refrigerator, the rotary reciprocating refrigerator, the solid hydrogen refrigerator, the solid hydrogen/multistage radiator hybrid cooler, and the magneto-Peltier hybrid cooler.

  5. Tropical cyclone rainfall area controlled by relative sea surface temperature.

    Science.gov (United States)

    Lin, Yanluan; Zhao, Ming; Zhang, Minghua

    2015-01-01

    Tropical cyclone rainfall rates have been projected to increase in a warmer climate. The area coverage of tropical cyclones influences their impact on human lives, yet little is known about how tropical cyclone rainfall area will change in the future. Here, using satellite data and global atmospheric model simulations, we show that tropical cyclone rainfall area is controlled primarily by its environmental sea surface temperature (SST) relative to the tropical mean SST (that is, the relative SST), while rainfall rate increases with increasing absolute SST. Our result is consistent with previous numerical simulations that indicated tight relationships between tropical cyclone size and mid-tropospheric relative humidity. Global statistics of tropical cyclone rainfall area are not expected to change markedly under a warmer climate provided that SST change is relatively uniform, implying that increases in total rainfall will be confined to similar size domains with higher rainfall rates. PMID:25761457

  6. Reducing Runoff Loss of Applied Nutrients in Oil Palm Cultivation Using Controlled-Release Fertilizers

    Directory of Open Access Journals (Sweden)

    A. Bah

    2014-01-01

    Full Text Available Controlled-release fertilizers are expected to minimize nutrient loss from crop fields due to their potential to supply plant-available nutrients in synchrony with crop requirements. The evaluation of the efficiency of these fertilizers in tropical oil palm agroecological conditions is not yet fully explored. In this study, a one-year field trial was conducted to determine the impact of fertilization with water soluble conventional mixture and controlled-release fertilizers on runoff loss of nutrients from an immature oil palm field. Soil and nutrient loss were monitored for one year in 2012/2013 under erosion plots of 16 m2 on 10% slope gradient. Mean sediments concentration in runoff amounted to about 6.41 t ha−1. Conventional mixture fertilizer posed the greatest risk of nutrient loss in runoff following fertilization due to elevated nitrogen (6.97%, potassium (13.37%, and magnesium (14.76% as percentage of applied nutrients. In contrast, this risk decreased with the application of controlled-release fertilizers, representing 0.75–2.44% N, 3.55–5.09% K, and 4.35–5.43% Mg loss. Meanwhile, nutrient loss via eroded sediments was minimal compared with loss through runoff. This research demonstrates that the addition of controlled-release fertilizers reduced the runoff risks of nutrient loss possibly due to their slow-release properties.

  7. Knowledge-Based Trajectory Error Pattern Method Applied to an Active Force Control Scheme

    Directory of Open Access Journals (Sweden)

    Endra Pitowarno, Musa Mailah, Hishamuddin Jamaluddin

    2012-08-01

    Full Text Available The active force control (AFC method is known as a robust control scheme that dramatically enhances the performance of a robot arm particularly in compensating the disturbance effects. The main task of the AFC method is to estimate the inertia matrix in the feedback loop to provide the correct (motor torque required to cancel out these disturbances. Several intelligent control schemes have already been introduced to enhance the estimation methods of acquiring the inertia matrix such as those using neural network, iterative learning and fuzzy logic. In this paper, we propose an alternative scheme called Knowledge-Based Trajectory Error Pattern Method (KBTEPM to suppress the trajectory track error of the AFC scheme. The knowledge is developed from the trajectory track error characteristic based on the previous experimental results of the crude approximation method. It produces a unique, new and desirable error pattern when a trajectory command is forced. An experimental study was performed using simulation work on the AFC scheme with KBTEPM applied to a two-planar manipulator in which a set of rule-based algorithm is derived. A number of previous AFC schemes are also reviewed as benchmark. The simulation results show that the AFC-KBTEPM scheme successfully reduces the trajectory track error significantly even in the presence of the introduced disturbances.Key Words:  Active force control, estimated inertia matrix, robot arm, trajectory error pattern, knowledge-based.

  8. Mathematical model of Lame Problem for Simplified Elastic Theory applied to Controlled-Clearance Pressure Balances

    CERN Document Server

    Silvano, Saragosa

    2010-01-01

    This paper is based on the original work of the master degree thesis [1] and also represents a revision of the models and the correlations with the analytical solutions given by other authors in the previous publications from 2003 to 2007. All the publications from 2003 to 2007 about simplified analytical methods applied to controlled-clearance pressure balances are not original re-elaborations (with some errors) of the thesis[1]. The analysis described in this paper starts with the mathematical model of thick-walled cylinder based on the solution of the Lame Equations applied to Mechanical theory of elastic equilibrium [5] for the formulation of the so called Simplified Elastic Theory that represents an analytical approach used in the study of the pressure balances. This analysis is well known as Lame problem. The solution of the Lame problem is used to determine the pressure distortion coefficient of controlled-clearance pressure balances. The analysis in this paper includes the case of pressure balances wi...

  9. Injection molding simulation with variothermal mold temperature control of highly filled polyphenylene sulfide

    Science.gov (United States)

    Birkholz, A.; Tschiersky, M.; Wortberg, J.

    2015-05-01

    For the installation of a fuel cell stack to convert chemical energy into electricity it is common to apply bipolar plates to separate and distribute reaction gases and cooling agents. For reducing manufacturing costs of bipolar plates a fully automated injection molding process is examined. The high performance thermoplastic matrix material, polyphenylene sulfide (PPS), defies against the chemical setting and the operation temperature up to 200 °C. To adjust also high electrical and thermal conductivity, PPS is highly filled with various carbon fillers up to an amount of 65 percentage by volume. In the first step two different structural plates (one-sided) with three different gate heights and molds are designed according to the characteristics of a bipolar plate. To cope with the approach that this plate should be producible on standard injection molding machines with variothermal mold temperature control, injection molding simulation is used. Additionally, the simulation should allow to formulate a quality prediction model, which is transferrable to bipolar plates. Obviously, the basis for a precise simulation output is an accurate description of the material properties and behavior of the highly filled compound. This, the design of the structural plate and mold and the optimization via simulation is presented, as well. The influence of the injection molding process parameters, e.g. injection time, cycle times, packing pressure, mold temperature, and melt temperature on the form filling have been simulated to determine optimal process conditions. With the aid of the simulation and the variothermal mold temperature control it was possible to reduce the required melt temperature below the decomposition temperature of PPS. Thereby, hazardous decomposition products as hydrogen sulfide are obviated. Thus, the health of the processor, the longevity of the injection molding machine as well as the material and product properties can be protected.

  10. Estimating the Impacts of Local Policy Innovation: The Synthetic Control Method Applied to Tropical Deforestation.

    Science.gov (United States)

    Sills, Erin O; Herrera, Diego; Kirkpatrick, A Justin; Brandão, Amintas; Dickson, Rebecca; Hall, Simon; Pattanayak, Subhrendu; Shoch, David; Vedoveto, Mariana; Young, Luisa; Pfaff, Alexander

    2015-01-01

    Quasi-experimental methods increasingly are used to evaluate the impacts of conservation interventions by generating credible estimates of counterfactual baselines. These methods generally require large samples for statistical comparisons, presenting a challenge for evaluating innovative policies implemented within a few pioneering jurisdictions. Single jurisdictions often are studied using comparative methods, which rely on analysts' selection of best case comparisons. The synthetic control method (SCM) offers one systematic and transparent way to select cases for comparison, from a sizeable pool, by focusing upon similarity in outcomes before the intervention. We explain SCM, then apply it to one local initiative to limit deforestation in the Brazilian Amazon. The municipality of Paragominas launched a multi-pronged local initiative in 2008 to maintain low deforestation while restoring economic production. This was a response to having been placed, due to high deforestation, on a federal "blacklist" that increased enforcement of forest regulations and restricted access to credit and output markets. The local initiative included mapping and monitoring of rural land plus promotion of economic alternatives compatible with low deforestation. The key motivation for the program may have been to reduce the costs of blacklisting. However its stated purpose was to limit deforestation, and thus we apply SCM to estimate what deforestation would have been in a (counterfactual) scenario of no local initiative. We obtain a plausible estimate, in that deforestation patterns before the intervention were similar in Paragominas and the synthetic control, which suggests that after several years, the initiative did lower deforestation (significantly below the synthetic control in 2012). This demonstrates that SCM can yield helpful land-use counterfactuals for single units, with opportunities to integrate local and expert knowledge and to test innovations and permutations on policies

  11. Estimating the Impacts of Local Policy Innovation: The Synthetic Control Method Applied to Tropical Deforestation.

    Directory of Open Access Journals (Sweden)

    Erin O Sills

    Full Text Available Quasi-experimental methods increasingly are used to evaluate the impacts of conservation interventions by generating credible estimates of counterfactual baselines. These methods generally require large samples for statistical comparisons, presenting a challenge for evaluating innovative policies implemented within a few pioneering jurisdictions. Single jurisdictions often are studied using comparative methods, which rely on analysts' selection of best case comparisons. The synthetic control method (SCM offers one systematic and transparent way to select cases for comparison, from a sizeable pool, by focusing upon similarity in outcomes before the intervention. We explain SCM, then apply it to one local initiative to limit deforestation in the Brazilian Amazon. The municipality of Paragominas launched a multi-pronged local initiative in 2008 to maintain low deforestation while restoring economic production. This was a response to having been placed, due to high deforestation, on a federal "blacklist" that increased enforcement of forest regulations and restricted access to credit and output markets. The local initiative included mapping and monitoring of rural land plus promotion of economic alternatives compatible with low deforestation. The key motivation for the program may have been to reduce the costs of blacklisting. However its stated purpose was to limit deforestation, and thus we apply SCM to estimate what deforestation would have been in a (counterfactual scenario of no local initiative. We obtain a plausible estimate, in that deforestation patterns before the intervention were similar in Paragominas and the synthetic control, which suggests that after several years, the initiative did lower deforestation (significantly below the synthetic control in 2012. This demonstrates that SCM can yield helpful land-use counterfactuals for single units, with opportunities to integrate local and expert knowledge and to test innovations and

  12. Design of closed loop temperature controller for CSRe internal target system

    International Nuclear Information System (INIS)

    It discusses the design of a closed loop temperature controller for CSRe internal target system of HIRFL-CSR. The controller provides temperature measuring resistor of nozzle 1mA constant current whose relative err is within 0.1% in the long time, obtains nozzle temperature using 12-bits ADC and implement refrigeration/heating closed loop operation through mixed signal processor MSP430F149. The temperature control precision of the controller is less than 0.5K based on experiments involved several experimental gases. Now, the controller works fine in the closed loop temperature control system. (authors)

  13. NetCDF based data archiving system applied to ITER Fast Plant System Control prototype

    Energy Technology Data Exchange (ETDEWEB)

    Castro, R., E-mail: rodrigo.castro@visite.es [Asociacion EURATOM/CIEMAT para Fusion, Madrid (Spain); Vega, J. [Asociacion EURATOM/CIEMAT para Fusion, Madrid (Spain); Ruiz, M.; De Arcas, G.; Barrera, E.; Lopez, J.M.; Sanz, D. [Grupo de Investigacion en Instrumentacion y Acustica Aplicada, UPM, Madrid (Spain); Goncalves, B.; Santos, B. [Associacao EURATOM/IST, IPFN - Laboratorio Associado, IST, Lisboa (Portugal); Utzel, N.; Makijarvi, P. [ITER Organization, St. Paul lez Durance Cedex (France)

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer Implementation of a data archiving solution for a Fast Plant System Controller (FPSC) for ITER CODAC. Black-Right-Pointing-Pointer Data archiving solution based on scientific NetCDF-4 file format and Lustre storage clustering. Black-Right-Pointing-Pointer EPICS control based solution. Black-Right-Pointing-Pointer Tests results and detailed analysis of using NetCDF-4 and clustering technologies on fast acquisition data archiving. - Abstract: EURATOM/CIEMAT and Technical University of Madrid (UPM) have been involved in the development of a FPSC (Fast Plant System Control) prototype for ITER, based on PXIe (PCI eXtensions for Instrumentation). One of the main focuses of this project has been data acquisition and all the related issues, including scientific data archiving. Additionally, a new data archiving solution has been developed to demonstrate the obtainable performances and possible bottlenecks of scientific data archiving in Fast Plant System Control. The presented system implements a fault tolerant architecture over a GEthernet network where FPSC data are reliably archived on remote, while remaining accessible to be redistributed, within the duration of a pulse. The storing service is supported by a clustering solution to guaranty scalability, so that FPSC management and configuration may be simplified, and a unique view of all archived data provided. All the involved components have been integrated under EPICS (Experimental Physics and Industrial Control System), implementing in each case the necessary extensions, state machines and configuration process variables. The prototyped solution is based on the NetCDF-4 (Network Common Data Format) file format in order to incorporate important features, such as scientific data models support, huge size files management, platform independent codification, or single-writer/multiple-readers concurrency. In this contribution, a complete description of the above mentioned solution

  14. 46 CFR 154.701 - Cargo pressure and temperature control: General.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Cargo pressure and temperature control: General. 154.701 Section 154.701 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS... Equipment Cargo Pressure and Temperature Control § 154.701 Cargo pressure and temperature control:...

  15. Spatial-temporal effects of temperature control device of stoplog intake for JinpingⅠhydropower station

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    This article presents an analysis of the spatial-temporal effect of multi-level stoplog gate intake adopted at Jinping I hydropower station,which is to reduce the adverse impacts on fish breeding caused by cold water discharged from the station in spring and summer.A mathematical model is applied to predict the temperature distribution in reservoir and outflow temperature process of the downstream of Jinping I station with two different types of intake-low level single intake and multi-level stoplog gate intake.For a single station,the latter shows great improvement over the former on temperature distortion(suitable for fish breeding) .In order to evaluate the cumulative effect for different intake types,the analysis is extended to include the next four hydropower stations downstream.The results show that the outflow temperature of stoplog intake is more close to the nature condition comparing with the low level intake for the Jinping I hydropower station.Especially the side effect of cold water in April during temperature raising period can be well improved,but no obvious effect in winter.Jinping I hydropower station has dominated influence on temperature process at lower reach of Yalong River.Influenced by the downstream hydropower station cascade,cold temperature effect in spring and summer seems to be cumulatively enhanced,but the heating effect turns weakened during winter.The analysis suggests the improving effect of stoplog intake can maintain 80%at estuary in April,which clearly shows that stratified intake scheme used in control station can mitigate the cold temperature effect in spring and summer for the whole river basin.

  16. Linear and non-linear control techniques applied to actively lubricated journal bearings

    Science.gov (United States)

    Nicoletti, R.; Santos, I. F.

    2003-03-01

    The main objectives of actively lubricated bearings are the simultaneous reduction of wear and vibration between rotating and stationary machinery parts. For reducing wear and dissipating vibration energy until certain limits, one can use the conventional hydrodynamic lubrication. For further reduction of shaft vibrations one can use the active lubrication action, which is based on injecting pressurized oil into the bearing gap through orifices machined in the bearing sliding surface. The design and efficiency of some linear (PD, PI and PID) and a non-linear controller, applied to a tilting-pad journal bearing, are analysed and discussed. Important conclusions about the application of integral controllers, responsible for changing the rotor-bearing equilibrium position and consequently the "passive" oil film damping coefficients, are achieved. Numerical results show an effective vibration reduction of unbalance response of a rigid rotor, where the PD and the non-linear P controllers show better performance for the frequency range of study (0-80 Hz). The feasibility of eliminating rotor-bearing instabilities (phenomena of whirl) by using active lubrication is also investigated, illustrating clearly one of its most promising applications.

  17. Hot roller embossing system equipped with a temperature margin-based controller

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seyoung, E-mail: seyoungkim@kimm.re.kr; Son, Youngsu; Lee, Sunghee; Ham, Sangyong; Kim, Byungin [Department of Robotics and Mechatronics, Korea Institute of Machinery and Materials (KIMM), Daejeon (Korea, Republic of)

    2014-08-15

    A temperature control system was proposed for hot roller embossing. The roll surface was heated using induction coils and cooled with a circulating chilled water system. The temperature of the roll surface was precisely controlled by a temperature margin-based control algorithm that we developed. Implementation of the control system reduced deviations in the roll surface temperature to less than ±2 °C. The tight temperature control and the ability to rapidly increase and decrease the roll temperature will allow optimum operating parameters to be developed quickly. The temperature margin-based controller could also be used to optimize the time course of electrical power and shorten the cooling time by choosing an appropriate temperature margin, possibly for limited power consumption. The chiller-equipped heating roll with the proposed control algorithm is expected to decrease the time needed to determine the optimal embossing process.

  18. Control and optimization of new patented induction carburizing technology by infrared temperature controlling system

    International Nuclear Information System (INIS)

    The New Induction Carburizing Technology is a simple, short, and inexpensive processing method for metal surface layer properties improving. The Part to be carburized along with an inductive heater are immersed in a liquid active medium and its surface is heated by high-frequency current. Processing time estimates in seconds or minutes only. Thickness, chemical composition, structure and properties of the protective diffusion surface layers can be adjusted for various applications by control and optimization of treatment parameters. It was done by infrared temperature controlling system which peculiarities are explained in this presentation. (author)

  19. A comparative study of the active force control schemes applied to robot arm

    International Nuclear Information System (INIS)

    In this paper, a comparative study of three different types of active force control (AFC) schemes applied to a robotic arm is described. The study particularly focuses on the techniques to compute the estimated inertia matrix (ΙΝ) of a robotic manipulator necessary for the execution of the AFC strategy since the computation of (ΙΝ) is the common central theme to all AFC-based schemes. The first of the three AFC schemes is based on the conventional method of obtaining (ΙΝ), the second uses artificial neural network while the third incorporates an iterative learning algorithm. The study also discusses the characteristics of the (ΙΝ) curves obtained, the trajectory track performance of the schemes and the effects of the modelled disturbances. The robustness of all the AFC schemes are also ascertained in the study. (Author)

  20. Pollution control technologies applied to coal-fired power plant operation

    International Nuclear Information System (INIS)

    Burning of fossil fuels is the major source of energy in today's global economy with over one-third of the world's power generation derived from coal combustion. Although coal has been a reliable, abundant, and relatively inexpensive fuel source for most of the 20th century, its future in electric power generation is under increasing pressure as environmental regulations become more stringent worldwide. Current pollution control technologies for combustion exhaust gas generally treat the release of regulated pollutants: sulfur dioxide, nitrogen oxides and particulate matter as three separate problems instead of as parts of one problem. New and improved technologies have greatly reduced the emissions produced per ton of burning coal. The term 'Clean Coal Combustion Technology' applies generically to a range of technologies designed to greatly reduce the emissions from coal-fired power plants. The wet methods of desulfurization at present are the widest applied technology in professional energetics. This method is economic and gives good final results but a future for clean technologies is the biomass. Power from biomass is a proven commercial option of the electricity generation in the World. An increasing number of power marketers are starting to offer environmentally friendly electricity, including biomass power, in response to the consumer demand and regulatory requirements. (authors)

  1. Intermittent spray cooling: A new technology for controlling surface temperature

    International Nuclear Information System (INIS)

    In this work, intermittent spray cooling is proposed as a new technological concept to remove heat fluxes with good performance and introduce the potential use of advanced control techniques in the development of thermal management systems. The objective of this research work is to provide further insight into the physics involved in the heat transfer process triggered by the impact of an intermittent spray, and further investigate the effects of injection system parameters, such as the frequency of injection, pulse duration, initial wall temperature, pressure of injection and impingement distance, on the intermittent cooling system's performance. The results include a brief description of the spray intermittent behavior, an analysis on its thermal response and an evaluation of its performance. The 'duty cycle', defined as the percentage of the cyclic time during which the cooling liquid is injected, is found to be the main parameter enabling a more accurate control of the cooling process. The experiments reported evidence that small duty cycles promote heat removal by phase-change. With larger duty cycles, the effect of reducing the time lag between consecutive injections is a greater interaction between cycles, eventually leading to the formation of a thin liquid film. As the duty cycle evolves toward the continuous spray condition, the cooling system's thermal response improves, but phase-change is mitigated, affecting the system's performance. Intermittent spray cooling is also compared with continuous spray cooling experiments and liquid savings has been estimated by 10-90% for the same energetic efficiencies reported in the literature. Finally, general guidelines are outlined for the design of thermal management systems based on intermittent spray cooling

  2. Effects of applied radio frequency power on low-temperature catalytic-free nanostructured carbon nitride films by rf PECVD

    Science.gov (United States)

    Ritikos, Richard; Othman, Maisara; Abdul Rahman, Saadah

    2016-06-01

    Low-temperature catalytic-free carbon nitride, CN x nanostructured thin films were produced by using radio frequency (rf) plasma-enhanced chemical vapor deposition employing a parallel-plate electrode configuration. The effects of varying applied rf power, P rf (30-100 W), on the formation of these structures were studied. Aligned nanostructured CN x films were produced at P rf as low as 40 W, but uniform highly vertical-aligned CN x nanorods were produced at P rf of 60 and 80 W. This was induced by the presence of high ion bombardment on the growing films and the preferential bonding of isonitrile to aromatic bonds in the nanostructures. It was also observed that nitrogen incorporation is highest in this range and the structure and bonding in the nanostructure reflects those of typical polymeric/amorphous carbon nitride films.

  3. A quality control procedure for seawater temperature data

    Digital Repository Service at National Institute of Oceanography (India)

    Ghosh, A; Pankajakshan, T.

    A three level quality check has been developed for seawater temperature data. The standards used in the procedure for the quality check are the characteristic property of vertical temperature distribution, watermass property and a standard...

  4. Plasmid vector with temperature-controlled gene expression

    International Nuclear Information System (INIS)

    In plasmid pBR327, a fragment 169 b.p. long including promotor p3 of the bla gene has been deleted. The deletional derivative so obtained (pSP2) has been used to construct a recombinant plasmid bearing a fragment of phage λ DNA with the p/sub R/ promotor and the gene of the temperature-sensitive repressor cI. It has been shown that the plasmid vector so constructed (pCE119) with promotor cR performs repressor-cI-controlled transcription of the bla gene, as a result of which induction for an hour at 420C leads to an almost 100-fold increase in the amount of product of the bla gene as compared with that at 320C. The possibility of the use of plasmid cPE119 for the expression of other genes has been demonstrated for the case of the semisynthetic β-galactosidase gene of E. coli. In this case, on induction of the cells with recombinant plasmid pCEZ12 for 3 hours at 420C, a 300-fold increase in the amount of active β-galactosidase, as compared with that at 320C, was observed. It is important to point out that under these conditions (at 420C), at least 99% of the cells containing the plasmid retain the phenotype lacZ+, which indicates the stability of the proposed vector system

  5. Performance of viscoelastic dampers (VED) under various temperatures and application of magnetorheological dampers (MRD) for seismic control of structures

    Science.gov (United States)

    Bhatti, Abdul Qadir

    2013-08-01

    A number of studies have been carried out to investigate the performance of viscoelastic dampers (VEDs) and magnetorheological dampers (MRDs) in controlling the seismic response of buildings, but very few of them regarding the effect of temperature on the behavior of those dampers. The energy absorption properties of the VEDs are dependent on the ambient temperature, excitation frequency and strain amplitude. Several mathematical models have been investigated for reproducing the experimental behavior of single degree of freedom VEDs and MEDs. Of these, only the fractional derivative model can reflect the influence of temperature which is, however, so complex that it is difficult to apply in structural analysis. In order to verify the effect of temperature, two case studies of structural element have been conducted: once using VED and once using MRD. Kelvin-Voigt mathematical model applied, they were investigated and after analyzing the results, the force vs. displacement showed that MRD achieved a high force capacity and a better performance than VED. Furthermore, the effect of the temperature in case of VED observed via plotting the dissipated energy hysteresis at different temperatures. These results validate the effect of the temperature as the lower the temperature the more viscous the dashpot element becomes, hence improving damping, but this is up to a specific low temperature.

  6. Soft-Sensing Method of Water Temperature Measurement for Controlled Cooling System

    Institute of Scientific and Technical Information of China (English)

    CAI Xiao-hui; ZHANG Dian-hua; WANG Guo-dong; LIU Xiang-hua; FAN Lei

    2003-01-01

    Aiming at the water temperature measuring problem for controlled cooling system of rolling plant, a new water temperature measuring method based on soft-sensing method with a water temperature model of on-line self correction parameter was built. A water temperature compensation factor model was also built to improve coiling temperature control precision. It was proved that the model meets production requirements. The soft-sensing technique has extensive applications in the field of metal forming.

  7. Quality Control of Temperature and Salinity from CTD based on Anomaly Detection

    CERN Document Server

    Castelão, Guilherme P

    2015-01-01

    The CTD is a set of sensors used by oceanographers to measure fundamental hydrographic properties of the oceans. It is characterized by a high precision product, only achieved if a quality control procedure identifies and removes the bad samples. Such procedure has been traditionally done by a sequence of independent tests that minimize false negatives. It is here proposed a novel approach to identify the bad samples as anomalies in respect to the typical behavior of good data. Several tests are combined into a single multidimensional evaluation to provide a more flexible classification criterion. The traditional approach is reproduced with an error of 0.04%, otherwise, the Anomaly Detection technique surpasses the reference if calibrated by visual inspection. CoTeDe is a Python package developed to apply the traditional and the Anomaly Detection quality control of temperature and salinity data from CTD, and can be extended to XBT, ARGO and other sensors.

  8. Neutron scattering techniques for betaine calcium chloride dihydrate under applied external field (temperature, electric field and hydrostatic pressure)

    International Nuclear Information System (INIS)

    We have studied with neutron scattering techniques betaine calcium chloride dihydrate (BCCD), a dielectric aperiodic crystal which displays a Devil's staircase type phase diagram made up of several incommensurate and commensurate phases, having a range of stability very sensitive to temperature, electric field and hydrostatic pressure. We have measured a global hysteresis of δ(T) of about 2-3 K in the two incommensurate phases. A structural study of the modulated commensurate phases 1/4 and 1/5 allows us to evidence that the atomic modulation functions are anharmonic. The relevance of the modelization of the modulated structure by polar Ising pseudo-spins is then directly established. On the basis of group theory calculation in the four dimensional super-space, we interpret this anharmonic modulation as a soliton regime with respect to the lowest-temperature non modulated ferroelectric phase. The continuous character of the transition to the lowest-temperature non modulated phase and the diffuse scattering observed in this phase are accounted for the presence of ferroelectric domains separated by discommensurations. Furthermore, we have shown that X-rays induce in BCCD a strong variation with time of irradiation of the intensity of satellite peaks, and more specifically for third order ones. This is why the 'X-rays' structural model is found more harmonic than the 'neutron' one. Under electric field applied along the vector b axis, we confirm that commensurate phases with δ = even/odd are favoured and hence are polar along this direction. We have evidenced at 10 kV / cm two new higher order commensurate phases in the phase INC2, corroborating the idea of a 'complete' Devil's air-case phase diagram. A phenomenon of generalized coexistence of phases occurs above 5 kV / cm. We have characterized at high field phase transitions between 'coexisting' phases, which are distinguishable from classical lock-in transitions. Under hydrostatic pressure, our results contradict

  9. Measurement of an electrical potential induced by normal stress applied to the interface of an ionic material at elevated temperatures

    International Nuclear Information System (INIS)

    The measurement of a potential difference between two surfaces of zirconia is reported, when a normal stress is applied to one surface, leaving the other surface stress free. The potential difference is proportional to the applied stress over a wide range. The proportionality constant represents a new thermodynamic measurement of the interfacial state because the measurement is reversible and independent of temperature. In zirconia, the proportionality constant is related to the volume and the charge on the oxygen ion by considering thermodynamic equilibrium among the electrochemical potentials of the oxygen ion at the stressed and unstressed interfaces. The agreement with theory is within 10% for specimens made of polycrystalline zirconia, or single crystal cubic zirconia of (100) orientation. The proportionality constant changes by up to 20% for other orientations of the single crystal; this change is attributed to differences in the effective charge on the oxygen ion on different surface orientations. The kinetics of the voltage response was also investigated in detail; it is consistent with the diffusion of the oxygen ion along the interface formed between the metal electrode and the zirconia surface. The present measurements provide the first experimental confirmation of the fundamental relationship between the chemical potential, the normal traction, and the atomic volume of species at interfaces of crystalline materials. The measurement has implications in further understanding of diffusional creep, creep cavitation and sintering in ionic (or partially ionic) solids

  10. Propulsive performance of a finite-temperature plasma flow in a magnetic nozzle with applied azimuthal current

    International Nuclear Information System (INIS)

    The plasma flow in a finite-electron-temperature magnetic nozzle, under the influence of an applied azimuthal current at the throat, is modeled analytically to assess its propulsive performance. A correction to the nozzle throat boundary conditions is derived by modifying the radial equilibrium of a magnetized infinite two-population cylindrical plasma column with the insertion of an external azimuthal body force for the electrons. Inclusion of finite-temperature effects, which leads to a modification of the radial density profile, is necessary for calculating the propulsive performance, which is represented by nozzle divergence efficiency and thrust coefficient. The solutions show that the application of the azimuthal current enhances all the calculated performance parameters through the narrowing of the radial density profile at the throat, and that investing power in this beam focusing effect is more effective than using the same power to pre-heat the electrons. The results open the possibility for the design of a focusing stage between the plasma source and the nozzle that can significantly enhance the propulsive performance of electron-driven magnetic nozzles

  11. Density of states and superconducting critical temperature vs the number of carriers in a triangular lattice under applied pressure

    International Nuclear Information System (INIS)

    We propose a band structure for a triangular lattice with nearest neighbor hopping, in terms of parameters which depend on applied pressure to the sample. Such a lattice is a representation of the compound, NaxCoO2· yH2O (Sodium Cobalt Oxyhydrate), which is superconducting at a critical temperature of Tc approx. 5 K. We calculate the density of states, N(ω) vs ω, for several values of the parameters which depend on pressure, distorting in this way the geometry of the lattice. We observe the frequency dependence of the density of states for the different parameters. For zero pressure, we have obtained a density of states which is not symmetric around ω = 0 and which is a different result with respect to a square lattice in 2-D. We also study the superconducting critical temperature, Tc, as a function of the chemical potential, μ. Tc and μ are calculated from two self.consistent BCS equations. As a natural result, we have studied the effect of pressure on Tc, relating the different van Hove singularities, which appear in the density of states, with the different Tc,max's. We then prove that ns mv, where ns is the number of logarithmic singularities and mv is the number of Tc,max's. We compare our results with relevant results in the literature. (author)

  12. Temperature predictions for geothermal exploration - a lithospheric-scale 3D approach applied to the northern Upper Rhine Graben

    Science.gov (United States)

    Freymark, Jessica; Sippel, Judith; Scheck-Wenderoth, Magdalena; Bär, Kristian; Fritsche, Johann-Gerhard; Kracht, Matthias; Stiller, Manfred

    2015-04-01

    The Upper Rhine Graben and its prolongation, the Hessian depression, were formed as part of the European Cenozoic Rift System in a complex extensional to transtensional setting. At present-day, the Upper Rhine Graben is one of the regions in Germany that are well suitable for deep geothermal exploitation. In the framework of the EU-funded project "IMAGE" (Integrated Methods for Advanced Geothermal Exploration) we aim to contribute to the development of an integrated and multidisciplinary approach for the exploration of geothermal reservoirs by understanding the processes and properties controlling the spatial distribution of key parameters such as the underground temperature. Typically, reservoir-scale numerical models are developed for predictions on the subsurface hydrothermal conditions and for reducing the risk of drilling non-productive geothermal wells. One major problem related to such models is setting appropriate boundary conditions that define, for instance, how much heat enters the reservoir from greater depths. To understand the deep thermal field of the northern Upper Rhine Graben in the federal state of Hessen, we first develop a 3D structural model that differentiates the main geological units of the lithosphere including the shallow sedimentary fill. This model allows to solve the steady-state conductive heat equation and understand the first-order controlling factors of the regional thermal field. We present the database (e.g. seismic reflection data) and the methodological workflow (involving, e.g., 3D gravity modelling) that were used to develop the lithospheric-scale 3D structural model. Furthermore, we show how certain features of the structural model such as thickness variations of the radiogenic-heat-producing crystalline crust control the temperature distribution in the subsurface.

  13. Enhanced performance of CdS/CdTe thin-film devices through temperature profiling techniques applied to close-spaced sublimation deposition

    Energy Technology Data Exchange (ETDEWEB)

    Xiaonan Li; Sheldon, P.; Moutinho, H.; Matson, R. [National Renewable Energy Lab., Golden, CO (United States)

    1996-05-01

    The authors describe a methodology developed and applied to the close-spaced sublimation technique for thin-film CdTe deposition. The developed temperature profiles consisted of three discrete temperature segments, which the authors called the nucleation, plugging, and annealing temperatures. They have demonstrated that these temperature profiles can be used to grow large-grain material, plug pinholes, and improve CdS/CdTe photovoltaic device performance by about 15%. The improved material and device properties have been obtained while maintaining deposition temperatures compatible with commercially available substrates. This temperature profiling technique can be easily applied to a manufacturing environment by adjusting the temperature as a function of substrate position instead of time.

  14. Temperature Control of Gas Chromatograph Based on Switched Delayed System Techniques

    OpenAIRE

    Xiao-Liang Wang; Ming-Xu Zhang; Kun-Zhi Liu; Xi-Ming Sun

    2014-01-01

    We address the temperature control problem of the gas chromatograph. We model the temperature control system of the gas chromatograph into a switched delayed system and analyze the stability by common Lyapunov functional technique. The PI controller parameters can be given based on the proposed linear matrix inequalities (LMIs) condition and the designed controller can make the temperature of gas chromatograph track the reference signal asymptotically. An experiment is given to illustrate the...

  15. Temperature Control of Gas Chromatograph Based on Switched Delayed System Techniques

    Directory of Open Access Journals (Sweden)

    Xiao-Liang Wang

    2014-01-01

    Full Text Available We address the temperature control problem of the gas chromatograph. We model the temperature control system of the gas chromatograph into a switched delayed system and analyze the stability by common Lyapunov functional technique. The PI controller parameters can be given based on the proposed linear matrix inequalities (LMIs condition and the designed controller can make the temperature of gas chromatograph track the reference signal asymptotically. An experiment is given to illustrate the effectiveness of the stability criterion.

  16. Edge-Localized mode control and transport generated by externally applied magnetic perturbations

    Energy Technology Data Exchange (ETDEWEB)

    Joseph, I. [Lawrence Livermore National Laboratory, Livermore, CA (United States)

    2012-06-15

    This article reviews the subject of edge localized mode (ELM) control using externally applied magnetic perturbations and proposes theoretical mechanisms that may be responsible for the induced transport changes. The first question that must be addressed is: what is the structure of magnetic field within the plasma? Although initial hypotheses focused on the possibility of the creation of a region of stochastic field lines at the tokamak edge, drift magnetohydrodynamics theory predicts that magnetic reconnection is strongly suppressed over the region of the pedestal with steep gradients and fast perpendicular rotation. Reconnection can only occur near the location where the perpendicular electron velocity vanishes, and hence the electron impedance nearly vanishes, or near the foot of the pedestal, where the plasma is sufficiently cold and resistive. The next question that must be addressed is: which processes are responsible for the observed transport changes, nonlinearity, turbulence, or stochasticity? Over the pedestal region where ions and electrons rotate in opposite directions relative to the perturbation, the quasilinear Lorentz force decelerates the electron fluid and accelerates the ion fluid. The quasilinear magnetic flutter flux is proportional to the force and produces an outward convective transport that can be significant. Over the pedestal region where the E x B flow and the electrons rotate in opposite directions relative to the perturbation, magnetic islands with a width on the order of the ion gyroradius can directly radiate drift waves. In addition, the combination of quasilinear electron transport and ion viscous transport can lead to a large net particle flux. Since there are many transport mechanisms that may be active simultaneously, it is important to determine which physical mechanisms are responsible for ELM control and to predict the scaling to future devices (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  17. Simulation of temperature field for temperature-controlled radio frequency ablation using a hyperbolic bioheat equation and temperature-varied voltage calibration: a liver-mimicking phantom study

    Science.gov (United States)

    Zhang, Man; Zhou, Zhuhuang; Wu, Shuicai; Lin, Lan; Gao, Hongjian; Feng, Yusheng

    2015-12-01

    This study aims at improving the accuracy of temperature simulation for temperature-controlled radio frequency ablation (RFA). We proposed a new voltage-calibration method in the simulation and investigated the feasibility of a hyperbolic bioheat equation (HBE) in the RFA simulation with longer durations and higher power. A total of 40 RFA experiments was conducted in a liver-mimicking phantom. Four mathematical models with multipolar electrodes were developed by the finite element method in COMSOL software: HBE with/without voltage calibration, and the Pennes bioheat equation (PBE) with/without voltage calibration. The temperature-varied voltage calibration used in the simulation was calculated from an experimental power output and temperature-dependent resistance of liver tissue. We employed the HBE in simulation by considering the delay time τ of 16 s. First, for simulations by each kind of bioheat equation (PBE or HBE), we compared the differences between the temperature-varied voltage-calibration and the fixed-voltage values used in the simulations. Then, the comparisons were conducted between the PBE and the HBE in the simulations with temperature-varied voltage calibration. We verified the simulation results by experimental temperature measurements on nine specific points of the tissue phantom. The results showed that: (1) the proposed voltage-calibration method improved the simulation accuracy of temperature-controlled RFA for both the PBE and the HBE, and (2) for temperature-controlled RFA simulation with the temperature-varied voltage calibration, the HBE method was 0.55 °C more accurate than the PBE method. The proposed temperature-varied voltage calibration may be useful in temperature field simulations of temperature-controlled RFA. Besides, the HBE may be used as an alternative in the simulation of long-duration high-power RFA.

  18. Simulation of Temperature Control in Fermentation Bioreactor for Ethanol Production

    OpenAIRE

    MARGINEAN Calin; MARGINEAN Ana-Maria; TRIFA Viorel

    2012-01-01

    Present paper deals with aspects regardingthe simulation of fermentation bioreactor process andfermentation bioreactor control for ethanolproduction. The bioreactor model was implemented inMatlab Simulink and the results of simulation usingdifferent control strategies are presentedcomparatively. Three types of control strategy are usedrespectively, PID, Neural Network Model PredictiveController (NN-MPC) and Nonlinear Auto RegressiveMoving Average(NARMA-L2) control strategy.

  19. A Review of Auditing Methods Applied to the Content of Controlled Biomedical Terminologies

    Science.gov (United States)

    Zhu, Xinxin; Fan, Jung-Wei; Baorto, David M.; Weng, Chunhua; Cimino, James J.

    2012-01-01

    Although controlled biomedical terminologies have been with us for centuries, it is only in the last couple of decades that close attention has been paid to the quality of these terminologies. The result of this attention has been the development of auditing methods that apply formal methods to assessing whether terminologies are complete and accurate. We have performed an extensive literature review to identify published descriptions of these methods and have created a framework for characterizing them. The framework considers manual, systematic and heuristic methods that use knowledge (within or external to the terminology) to measure quality factors of different aspects of the terminology content (terms, semantic classification, and semantic relationships). The quality factors examined included concept orientation, consistency, non-redundancy, soundness and comprehensive coverage. We reviewed 130 studies that were retrieved based on keyword search on publications in PubMed, and present our assessment of how they fit into our framework. We also identify which terminologies have been audited with the methods and provide examples to illustrate each part of the framework. PMID:19285571

  20. A safety assessment methodology applied to CNS/ATM-based air traffic control system

    International Nuclear Information System (INIS)

    In the last decades, the air traffic system has been changing to adapt itself to new social demands, mainly the safe growth of worldwide traffic capacity. Those changes are ruled by the Communication, Navigation, Surveillance/Air Traffic Management (CNS/ATM) paradigm , based on digital communication technologies (mainly satellites) as a way of improving communication, surveillance, navigation and air traffic management services. However, CNS/ATM poses new challenges and needs, mainly related to the safety assessment process. In face of these new challenges, and considering the main characteristics of the CNS/ATM, a methodology is proposed at this work by combining 'absolute' and 'relative' safety assessment methods adopted by the International Civil Aviation Organization (ICAO) in ICAO Doc.9689 , using Fluid Stochastic Petri Nets (FSPN) as the modeling formalism, and compares the safety metrics estimated from the simulation of both the proposed (in analysis) and the legacy system models. To demonstrate its usefulness, the proposed methodology was applied to the 'Automatic Dependent Surveillance-Broadcasting' (ADS-B) based air traffic control system. As conclusions, the proposed methodology assured to assess CNS/ATM system safety properties, in which FSPN formalism provides important modeling capabilities, and discrete event simulation allowing the estimation of the desired safety metric.

  1. A new bio-inspired perceptual control architecture applied to solving navigation tasks

    Science.gov (United States)

    Arena, P.; De Fiore, S.; Patané, L.; Vitanza, A.

    2009-05-01

    In this paper a new general purpose perceptual control architecture is presented and applied to robot navigation in cluttered environments. In nature, insects show the ability to react to certain stimuli with simple reflexes using direct sensory-motor pathways, which can be considered as basic behaviors, while high brain regions provide secondary pathway allowing the emergence of a cognitive behavior which modulates the basic abilities. Taking inspiration from this evidence, our architecture modulates, through a reinforcement learning, a set of competitive and concurrent basic behaviors in order to accomplish the task assigned through a reward function. The core of the architecture is constituted by the Representation layer, where different stimuli, triggering competitive reflexes, are fused to form a unique abstract picture of the environment. The representation is formalized by means of Reaction-Diffusion nonlinear partial differential equations, under the paradigm of the Cellular Neural Networks, whose dynamics converges to steady-state Turing patterns. A suitable unsupervised learning, introduced at the afferent (input) stage, leads to the shaping of the basins of attractions of the Turing patterns in order to incrementally drive the association between sensor stimuli and patterns. In this way, at the end of the leaning stage, each pattern is characteristic of a particular behavior modulation, while its trained basin of attraction contains the set of all the environment conditions, as recorded through the sensors, leading to the emergence of that particular behavior modulation. Robot simulations are reported to demonstrate the potentiality and the effectiveness of the approach.

  2. FTIR-ATR spectroscopy applied to quality control of grape-derived spirits.

    Science.gov (United States)

    Anjos, Ofélia; Santos, António J A; Estevinho, Letícia M; Caldeira, Ilda

    2016-08-15

    The Fourier transform infrared (FTIR) spectroscopic method with attenuated total reflectance (ATR) was used for predicting the alcoholic strength, the methanol, acetaldehyde and fusel alcohols content of grape-derived spirits. FTIR-ATR spectrum in the mid-IR region (4000-400cm(-1)) was used for the quantitative estimation by applying partial least square (PLS) regression models and the results were correlated with those obtained from reference methods. In the developed method, a cross-validation with 50% of the samples was used for PLS analysis along with a validation test set with 50% of the remaining samples. Good correlation models with a great accuracy were obtained for methanol (r(2)=99.4; RPD=12.8), alcoholic strength (r(2)=97.2; RPD=6.0), acetaldehyde (r(2)=98.2; RPD=7.5) and fusel alcohols (r(2) from 97.4 to 94.1; RPD from 6.2 to 4.1). These results corroborate the hypothesis that FTIR-ATR is a useful technique for the quality control of grape-derived spirits, whose practical application may improve the efficiency and quickness of the current laboratory analysis. PMID:27006210

  3. Advances in control of frost on evaporator coils with an applied electric field

    Energy Technology Data Exchange (ETDEWEB)

    Tudor, V. [Advanced Thermal Research Laboratory, Mechanical Engineering Department, US Naval Academy, Annapolis, MD 21402 (United States); Ohadi, M. [Smart and Small Thermal Systems Laboratory, Mechanical Engineering Department, University of Maryland, College park, MD 20742 (United States); Salehi, M.A.; Lawler, J.V. [ATEC Inc., College Park, MD 20742 (United States)

    2005-10-01

    This paper introduces an innovative technique on use of an applied electric field for control of frost over evaporator coils with fin density and geometric configuration of interest to freezer/refrigerator applications. The technique discussed in this paper, referred to as the 'dielectric barrier discharge' (DBD) method, may be particularly suitable for application in evaporator coils with high fin density. Experiments conducted with a small-scale laboratory test-module, as well as a full-scale supermarket evaporator are presented. The DBD technique is based on generating localized non-resistive heating within fins of an evaporator coil via application of a high-voltage, alternating current through electrodes. Our experiments demonstrate that the defrosting time using DBD is substantially shorter than conventional techniques, while the energy consumption associated with the process is less than one half of the corresponding energy of the electrical resistance heating methods. Basic operational principles of the technique, its advantages and limitations when compared to conventional electrical defrosting techniques are discussed and presented for the first time in this paper. (author)

  4. Improved Broadband Liner Optimization Applied to the Advanced Noise Control Fan

    Science.gov (United States)

    Nark, Douglas M.; Jones, Michael G.; Sutliff, Daniel L.; Ayle, Earl; Ichihashi, Fumitaka

    2014-01-01

    The broadband component of fan noise has grown in relevance with the utilization of increased bypass ratio and advanced fan designs. Thus, while the attenuation of fan tones remains paramount, the ability to simultaneously reduce broadband fan noise levels has become more desirable. This paper describes improvements to a previously established broadband acoustic liner optimization process using the Advanced Noise Control Fan rig as a demonstrator. Specifically, in-duct attenuation predictions with a statistical source model are used to obtain optimum impedance spectra over the conditions of interest. The predicted optimum impedance information is then used with acoustic liner modeling tools to design liners aimed at producing impedance spectra that most closely match the predicted optimum values. Design selection is based on an acceptance criterion that provides the ability to apply increased weighting to specific frequencies and/or operating conditions. Constant-depth, double-degree of freedom and variable-depth, multi-degree of freedom designs are carried through design, fabrication, and testing to validate the efficacy of the design process. Results illustrate the value of the design process in concurrently evaluating the relative costs/benefits of these liner designs. This study also provides an application for demonstrating the integrated use of duct acoustic propagation/radiation and liner modeling tools in the design and evaluation of novel broadband liner concepts for complex engine configurations.

  5. Unified Desktop for Monitoring & Control Applications - The Open Navigator Framework Applied for Control Centre and EGSE Applications

    Science.gov (United States)

    Brauer, U.

    2007-08-01

    The Open Navigator Framework (ONF) was developed to provide a unified and scalable platform for user interface integration. The main objective for the framework was to raise usability of monitoring and control consoles and to provide a reuse of software components in different application areas. ONF is currently applied for the Columbus onboard crew interface, the commanding application for the Columbus Control Centre, the Columbus user facilities specialized user interfaces, the Mission Execution Crew Assistant (MECA) study and EADS Astrium internal R&D projects. ONF provides a well documented and proven middleware for GUI components (Java plugin interface, simplified concept similar to Eclipse). The overall application configuration is performed within a graphical user interface for layout and component selection. The end-user does not have to work in the underlying XML configuration files. ONF was optimized to provide harmonized user interfaces for monitoring and command consoles. It provides many convenience functions designed together with flight controllers and onboard crew: user defined workspaces, incl. support for multi screens efficient communication mechanism between the components integrated web browsing and documentation search &viewing consistent and integrated menus and shortcuts common logging and application configuration (properties) supervision interface for remote plugin GUI access (web based) A large number of operationally proven ONF components have been developed: Command Stack & History: Release of commands and follow up the command acknowledges System Message Panel: Browse, filter and search system messages/events Unified Synoptic System: Generic synoptic display system Situational Awareness : Show overall subsystem status based on monitoring of key parameters System Model Browser: Browse mission database defintions (measurements, commands, events) Flight Procedure Executor: Execute checklist and logical flow interactive procedures Web

  6. Quality control procedures applied to nuclear instruments. Proceedings of a technical meeting

    International Nuclear Information System (INIS)

    Quality Control (QC), test procedures for Nuclear Instrumentation are important for assurance of proper and safe operation of the instruments, especially with regard to equipment related to radiological safety, human health and national safety. Correct measurements of radiation parameters must be ensured, i.e., accurate measurement of the number of radioactive events, counting times and in some cases accurate measurements of the radiation energy and occurring time of the nuclear events. There are several kinds of testing on nuclear instruments, for example, type-testing done by suppliers, acceptance testing made by the end users, Quality Control tests after repair and Quality Assurance/Quality Controls tests made by end-users. All of these tests are based in many cases on practical guidelines or on the experience of the own specialist, the available standards on this topic also need to be adapted to specific instruments. The IAEA has provided nuclear instruments and supported the operational maintenance efforts of the Member States. Although Nuclear Instrumentation is continuously upgraded, some older or aged instruments are still in use and in good working condition. Some of these instruments may not, however, meet modern requirements for the end-user therefore, Member States, mostly those with emerging economies, modernize/refurbish such instruments to meet the end-user demands. As a result, new instrumentation which is not commercially available, or modernized/refurbished instruments, need to be tested or verified with QC procedures to meet national or international certification requirements. A technical meeting on QC procedures applied to nuclear instruments was organized in Vienna from 23 to 24 August 2007. Existing and required QC test procedures necessary for the verification of operation and measurement of the main characteristics of nuclear instruments was the focus of discussion at this meeting. Presentations made at the technical meeting provided

  7. Loop Heat Pipe Operation Using Heat Source Temperature for Set Point Control

    Science.gov (United States)

    Ku, Jentung; Paiva, Kleber; Mantelli, Marcia

    2011-01-01

    The LHP operating temperature is governed by the saturation temperature of its reservoir. Controlling the reservoir saturation temperature is commonly accomplished by cold biasing the reservoir and using electrical heaters to provide the required control power. Using this method, the loop operating temperature can be controlled within +/- 0.5K. However, because of the thermal resistance that exists between the heat source and the LHP evaporator, the heat source temperature will vary with its heat output even if LHP operating temperature is kept constant. Since maintaining a constant heat source temperature is of most interest, a question often raised is whether the heat source temperature can be used for LHP set point temperature control. A test program with a miniature LHP has been carried out to investigate the effects on the LHP operation when the control temperature sensor is placed on the heat source instead of the reservoir. In these tests, the LHP reservoir is cold-biased and is heated by a control heater. Tests results show that it is feasible to use the heat source temperature for feedback control of the LHP operation. Using this method, the heat source temperature can be maintained within a tight range for moderate and high powers. At low powers, however, temperature oscillations may occur due to interactions among the reservoir control heater power, the heat source mass, and the heat output from the heat source. In addition, the heat source temperature could temporarily deviate from its set point during fast thermal transients. The implication is that more sophisticated feedback control algorithms need to be implemented for LHP transient operation when the heat source temperature is used for feedback control.

  8. Rapid determination of chemical oxygen demand using a focused microwave heating system featuring temperature control

    International Nuclear Information System (INIS)

    This paper demonstrates the use of a microwave heating system, employed in the chemical digestion step, for the determination of chemical oxygen demand in wastewater. The results are first compared with those provided by standard methods using reference substances. The problems arising from abrupt heating of the sample and the potential thermal decomposition of potassium dichromate are examined. Two different approaches to sample digestion involving a gradually increasing irradiation time were tested. First, a constant power strategy is applied, and the second proposes a constant temperature approach by using a temperature control system. By optimising the operating conditions, the digestion time was reduced to 8-60 times with respect to the standard method. The reference digestion time is 5 min. In especially difficult digestions, the proposed approach provides a substantially improved degradation with respect to conventional procedures. The procedure was applied to wastewater from various industries and found to ensure thorough digestion of all samples and to provide favourable results in all cases tested

  9. Temperature and humidity independent control (THIC) of air-conditioning system

    CERN Document Server

    Liu, Xiaohua; Zhang, Tao

    2014-01-01

    This book presents the main components of the Temperature and Humidity Independent Control (THIC) of air-conditioning systems, including dehumidification devices, high-temperature cooling devices and indoor terminal devices.

  10. Design of a reactor inlet temperature controller for EBR-2 using state feedback

    International Nuclear Information System (INIS)

    A new reactor inlet temperature controller for pool type liquid-metal reactors has been developed and will be tested in EBR-II. The controller makes use of modern control techniques to take into account stratification and mixing in the cold pool during normal operation. Secondary flowrate is varied so that the reactor inlet temperature tracks a setpoint while reactor outlet temperature, primary flowrate and secondary cold leg temperature are treated as exogenous disturbances and are free to vary. A disturbance rejection technique minimizes the effect of these disturbances on inlet temperature. A linear quadratic regulator improves inlet temperature response. Tests in EBR-II will provide experimental data for assessing the performance improvements that modern control can produce over the existing EBR-II analog inlet temperature controller. 10 refs., 8 figs

  11. [Varying opinions of the temperature method of birth control].

    Science.gov (United States)

    Holt, J G

    1963-01-01

    An analysis of 10 works published between 1958-62 which provide instructions for use of the temperature method of birth limitation indicates a considerable discrepancy in the advice provided. Couples wishing to conceive would be interested in identifying as closely as possible the moment of ovulation, but couples wishing to avoid conception need to know the times of absolute sterility, and for them, concern with ovulation itself unnecessarily complicates the method. 3 of the 8 authors indicated that it is not necessary to identify the moment of ovulation and that the temperature curve itself would provide sufficient warning of fertile days. 2 authors advised monitoring of other signs of ovulation as well as the temperature curve, and another suggested noting the lowest temperature in preparation for the rise. The sources were also in disagreement as to whether a temperature curve could adequately be read by the couple or whether the constant advice of a trained phisician would be required. All authors were agreed that the time of highest temperature is absolutely sterile, but there was less agreement about how to identify the onset of the sterile period. Some authors argeed that with practice the eye would distinguish the temperature shift, while others called for a temperature of 37 degrees Celsius for 2 days or for the usual highest temperature for 2 days. Disagreement about the days preceding menstruation was even greater. The main cause of conflicting advise is the fact that the authors are not agreed as to how to determine the fertile period, and compounding the difficulty is the tendency to allow too small a margin for variation and exceptional cases. PMID:12266598

  12. Independent Cooling Controller for Temperature Control of High Strength and Atmosphere Corrosion Resisting Steel in Hot Strip Mills

    Energy Technology Data Exchange (ETDEWEB)

    Park, Cheol Jae [Daegu University, Kyungsan (Korea, Republic of)

    2015-03-15

    In this paper, we propose an independent cooling control (ICC) scheme for high strength and atmosphere corrosion resisting steel to obtain the desired temperature and properties along the longitudinal direction of the steel in the run-out table (ROT) process. A temperature model of the independent process is developed to divide the ROT into front and back sections. The control concept uses field data, problem analysis, and a time-temperature transformation diagram. The effectiveness of the proposed control is verified using simulation results under a temperature disturbance by the transformation in the middle of the ROT. The results of a hot strip mill field test show that the temperature control performance is significantly improved by the proposed control scheme.

  13. A Real-Time Temperature Data Transmission Approach for Intelligent Cooling Control of Mass Concrete

    OpenAIRE

    Peng Lin; Qingbin Li; Pinyu Jia

    2014-01-01

    The primary aim of the study presented in this paper is to propose a real-time temperature data transmission approach for intelligent cooling control of mass concrete. A mathematical description of a digital temperature control model is introduced in detail. Based on pipe mounted and electrically linked temperature sensors, together with postdata handling hardware and software, a stable, real-time, highly effective temperature data transmission solution technique is developed and utilized wit...

  14. UV trimming of polarization-independent microring resonator by internal stress and temperature control

    OpenAIRE

    Kobayashi, Naoki; Sato, Tomoyuki; Kobubun, Yasuo

    2010-01-01

    The temperature dependence of the resonant wavelength of vertically coupled microring resonator can be controlled via internal stress caused by the thermo-optic and photo-elastic effects. In the case of strong internal stress, a polarization-independent microring resonator can be realized by controlling the device surface temperature using a heater module; the temperature dependence of TE and TM polarizations are different due to the internal stress and thus manipulating temperatures, the res...

  15. Development of an object-oriented software based on fuzzy-logic for controlling temperatures in PAC experiments

    International Nuclear Information System (INIS)

    The Hyperfine Interaction Laboratory at Instituto de Pesquisas Energeticas e Nucleares (IPEN) has been using Perturbed Angular Correlation (PAC) technique for studying material science for more than 20 years. One of the important aspects of the research involves the study of the behavior of measured properties of samples as a function of temperature. For temperatures higher than room temperature a small resistance furnace is used to heat the sample. The need to carry out the PAC measurement at predefined temperatures steps in a programmed manner is obvious. The present work describes a procedure for the furnace temperature control and automatic data acquisition at different temperatures based on fuzzy logic. The procedure consists in determining the linguistic input (temp, Δtemp) and output (pow) variables and their pertinence functions. After defining the variables, an object.oriented program is written in Java language which is an interface between principal data acquisition program and electronic temperature controller of the mini furnace. In addition to the implementation of the class that involves the fuzzy logic and classes with strategic algorithms defined for each temperature range there are classes of communication between systems based on modbus protocol RTU (Remote Terminal Unit) connected to serial interface RS-488. In this manner the applied technology for the development of software permits higher software life requiring only small alterations or implementation of classes in the use with new equipment. (author)

  16. Study for the Effect of Continuously Applied Load on a Compressed Ag Nanoparticle at Room Temperature by Atomic Scale Simulations

    Science.gov (United States)

    Zhang, Lin

    2016-05-01

    Molecular dynamics calculations are reported for structural transition of a compressed Ag nanoparticle containing 2123 atoms with a crystal structure during the processes of continuously applied load at room temperature. Analytical tools are used to demonstrate the effect of the load on the packing patterns in this deformed particle including internal energy per atom, pair distribution functions, coordination number, pair number as well as the cross-sectional images, and mean square displacements. The simulation results show that the deformation processes of this particle include different stages. Owing to the atom sliding in the (111) plane in different regions of this particle, some interfaces are formed between these regions, and they are barriers of atom movements. With increasing the load, the interfaces in the middle of this particle are disappeared, and the deformation is able to carry out. At larger load, new interfaces are formed in the different regions of this heavily compressed particle with several atom layers, and these interfaces again become obstacles for the further deformation.

  17. Temperature Control Method in the Snow Road Construction

    Science.gov (United States)

    Serebrenikova, Yu; Lysyannikov, A.; Kaizer, Yu; Zhelykevich, R.; Plakhotnikova, M.; Lysyannikova, N.; Merko, M.; Merko, I.

    2016-06-01

    The paper substantiates the process of heat treatment before the snow compaction in snow road construction. The methods to measure the temperature of snow as a moving dispersed material have been considered in the paper.

  18. Temperature Control System for Biochemical Reactions in Microchip-Based Devices

    Institute of Scientific and Technical Information of China (English)

    荆高山; 张坚; 朱小山; 冯继宏; 谭智敏; 刘理天; 程京

    2001-01-01

    A silicon-glass chip based microreactor has been designed and fabricated for biochemical reactions such as polymerase chain reactions (PCR). The chip based microreactor has integrated resistive heating elements. The computer-controlled temperature control system is highly reliable with precise temperature control, excellent temperature uniformity, and rapid heating and cooling capabilities. The development of the microreaction system is an important step towards the construction of a lab-on-a-chip system.

  19. Micro thermoindicators and optical-electronic temperature control for microfluidic applications

    Science.gov (United States)

    Liu, Liyu; Peng, Suili; Wen, Weijia; Sheng, Ping

    2007-08-01

    The authors report the design and implementation of sensing and control of local temperature in polydimethylsiloxane microfluidic reaction chip, based on the fabrication of a microtemperature sensor with thermochromic color bars and the associated optical and electronic feedback controls. The thermochromic color bar demonstrates easy and accurate local temperature monitoring. In combination with a microheater, this contactless microchip temperature control approach may have wide application potentials in microchemical and microbiological analyses.

  20. Temperature control during diode laser welding in a human cornea

    Science.gov (United States)

    Rossi, Francesca; Matteini, Paolo; Pini, Roberto; Menabuoni, Luca

    2007-07-01

    Diode laser welding is a technique proposed in ophthalmic surgery to induce immediate sealing of clear corneal wounds. The welding effect is achieved irradiating the area, previously treated with a chromophore, by the use of a low power diode laser: the resulting thermal effect induces structural modifications in the stromal collagen, that welds upon cooling. We present a study on the temperature dynamics developing during welding in a human eye. An infrared thermocamera was used to measure the temperature variations on the surface of the cornea during clinical penetrating keratoplasty (corneal transplant). The experimental data were used as a starting point for a theoretical investigation of the temperature rising inside the ocular structures: we developed a mathematical model based on the bio-heat equation and solved by the use of the Finite Element Method (FEM). The predictive accuracy was verified by comparing the temperature post-processing description with the results obtained from the thermographic data. The model was then used to study the temperature rise and heat propagation inside the eye. Experimental results and model analysis indicated the occurrence of heat confinement during the treatment procedure and a modest enhancement of the temperature (reaching about 55°C inside the laser treated wound), thus evidencing the safety of the procedure in clinical applications.

  1. Multiclassifier system with hybrid learning applied to the control of bioprosthetic hand.

    Science.gov (United States)

    Kurzynski, Marek; Krysmann, Maciej; Trajdos, Pawel; Wolczowski, Andrzej

    2016-02-01

    In this paper the problem of recognition of the intended hand movements for the control of bio-prosthetic hand is addressed. The proposed method is based on recognition of electromiographic (EMG) and mechanomiographic (MMG) biosignals using a multiclassifier system (MCS) working in a two-level structure with a dynamic ensemble selection (DES) scheme and original concepts of competence function. Additionally, feedback information coming from bioprosthesis sensors on the correct/incorrect classification is applied to the adjustment of the combining mechanism during MCS operation through adaptive tuning competences of base classifiers depending on their decisions. Three MCS systems operating in decision tree structure and with different tuning algorithms are developed. In the MCS1 system, competence is uniformly allocated to each class belonging to the group indicated by the feedback signal. In the MCS2 system, the modification of competence depends on the node of decision tree at which a correct/incorrect classification is made. In the MCS3 system, the randomized model of classifier and the concept of cross-competence are used in the tuning procedure. Experimental investigations on the real data and computer-simulated procedure of generating feedback signals are performed. In these investigations classification accuracy of the MCS systems developed is compared and furthermore, the MCS systems are evaluated with respect to the effectiveness of the procedure of tuning competence. The results obtained indicate that modification of competence of base classifiers during the working phase essentially improves performance of the MCS system and that this improvement depends on the MCS system and tuning method used. PMID:25982067

  2. Application of Temperature-Dependent Fluorescent Dyes to the Measurement of Millimeter Wave Absorption in Water Applied to Biomedical Experiments

    OpenAIRE

    Nataliia Kuzkova; Oleksandr Popenko; Andrey Yakunov

    2014-01-01

    Temperature sensitivity of the fluorescence intensity of the organic dyes solutions was used for noncontact measurement of the electromagnetic millimeter wave absorption in water. By using two different dyes with opposite temperature effects, local temperature increase in the capillary that is placed inside a rectangular waveguide in which millimeter waves propagate was defined. The application of this noncontact temperature sensing is a simple and novel method to detect temperature change in...

  3. Electric field control of room temperature ferromagnetism in III-N dilute magnetic semiconductor films

    Science.gov (United States)

    Nepal, N.; Luen, M. Oliver; Zavada, J. M.; Bedair, S. M.; Frajtag, P.; El-Masry, N. A.

    2009-03-01

    We report on the electrical field control of ferromagnetism (FM) at room temperature in III-N dilute magnetic semiconductor (DMS) films. A GaMnN layer was grown on top of an n-GaN substrate and found to be almost always paramagnetic. However, when grown on a p-type GaN layer, a strong saturation magnetization (Ms) was observed. This FM in GaMnN can be controlled by depletion of the holes in the GaMnN/p-GaN/n-GaN multilayer structures. We have demonstrated the dependence of the FM on the thickness of the p-GaN in this heterostructure and on the applied bias to the GaN p-n junction. The Ms was measured by an alternating gradient magnetometer (AGM) and a strong correlation between the hole concentration near the GaMnN/p-GaN interface and the magnetic properties of the DMS was observed. At room temperature an anomalous Hall effect was measured for zero bias and an ordinary Hall effect for reverse bias in a fully depleted p-GaN layer. This is in close agreement with the AGM measurement results.

  4. Fire and soil temperatures during controlled burns in seasonally dry tropical forests of southern India

    OpenAIRE

    Mondal, Nandita; Sukumar, Raman

    2014-01-01

    Fire and soil temperatures were measured during controlled burns conducted by the Forest Department at two seasonally dry tropical forest sites in southern India, and their relationships with fuel load, fuel moisture and weather variables assessed using stepwise regression. Fire temperatures at the ground level varied between 79 degrees C and 760 degrees C, with higher temperatures recorded at high fuel loads and ambient temperatures, whereas lower temperatures were recorded at high relative ...

  5. MSW oxy-enriched incineration technology applied in China: combustion temperature, flue gas loss and economic considerations.

    Science.gov (United States)

    Fu, Zhe; Zhang, Shihong; Li, Xiangpeng; Shao, Jingai; Wang, Ke; Chen, Hanping

    2015-04-01

    To investigate the application prospect of MSW oxy-enriched incineration technology in China, the technical and economical analyses of a municipal solid waste (MSW) grate furnace with oxy-fuel incineration technology in comparison to co-incineration with coal are performed. The rated capacity of the grate furnace is 350 tonnes MSW per day. When raw MSW is burned, the amount of pure oxygen injected should be about 14.5 wt.% under 25% O2 oxy-fuel combustion conditions with the mode of oxygen supply determined by the actual situation. According to the isothermal combustion temperature (Ta), the combustion effect of 25% O2 oxy-enriched incineration (α = 1.43) is identical with that of MSW co-incineration with 20% mass ratio of coal (α = 1.91). However, the former is better than the latter in terms of plant cost, flue gas loss, and environmental impact. Despite the lower costs of MSW co-incineration with mass ratio of 5% and 10% coal (α = 1.91), 25% O2 oxy-enriched incineration (α = 1.43) is far more advantageous in combustion and pollutant control. Conventional combustion flue gas loss (q2) for co-incineration with 0% coal, 20% coal, 10% coal, 5% coal are around 17%, 13%, 14% and 15%, respectively, while that under the condition of 25% O2 oxy-enriched combustion is approximately 12% (α = 1.43). Clearly, q2 of oxy-enriched incineration is less than other methods under the same combustion conditions. High moisture content presents challenges for MSW incineration, therefore it is necessary to dry MSW prior to incineration, and making oxy-enriched incineration technology achieves higher combustion temperature and lower flue gas loss. In conclusion, based on technical and economical analysis, MSW oxy-enriched incineration retains obvious advantages and demonstrates great future prospects for MSW incineration in China. PMID:25680237

  6. A REVIEW OF INTELLIGENT CONTROL SYSTEMS APPLIED TO THE INVERTED-PENDULUM PROBLEM

    OpenAIRE

    Pedro Ponce; Arturo Molina; Eugenio Eugenio

    2014-01-01

    This study shows the latest advances in the application of intelligent control to the inverted-pendulum problem. A complete review regarding intelligent control design is presented in this study in order to show the most important artificial intelligence methods used for controlling an Inverted-Pendulum. Also this study proposed the use of a neural-fuzzy-with-genetic-algorithms controller for the inverted pendulum problem which gives good results. Conventional controllers are presented in ord...

  7. Experimental evaluation of radiator control based on primary supply temperature for district heating substations

    International Nuclear Information System (INIS)

    Highlights: → We compared a new radiator system control approach with traditional control. → This is an experimental verification of previous simulation results. → We examine changes in delta-T and indoor comfort. → The indoor comfort were not affected by the introduction of alt. radiator control. → The alternative control method can contribute to an increased delta-T. -- Abstract: In this paper, we evaluate whether the primary supply temperature in district heating networks can be used to control radiator systems in buildings connected to district heating; with the purpose of increasing the ΔT. The primary supply temperature in district heating systems can mostly be described as a function of outdoor temperature; similarly, the radiator supply temperature in houses, offices and industries can also be described as a function of outdoor temperature. To calibrate the radiator control system to produce an ideally optimal radiator supply temperature that produces a maximized ΔT across the substation, the relationship between the primary supply temperature and outdoor temperature must be known. However, even if the relation is known there is always a deviation between the expected primary supply temperature and the actual temperature of the received distribution media. This deviation makes the radiator control system incapable of controlling the radiator supply temperature to a point that would generate a maximized ΔT. Published simulation results show that it is possible and advantageous to utilize the primary supply temperature for radiator system control. In this paper, the simulation results are experimentally verified through implementation of the control method in a real district heating substation. The primary supply temperature is measured by the heat-meter and is shared with the radiator control system; thus no additional temperature sensors were needed to perform the experiments. However additional meters were installed for surveillance purposes

  8. Design and Development and Hardware Implementation of Fuzzy Knowledge Based Intelligent Temperature Control System

    Directory of Open Access Journals (Sweden)

    Deepak Bharadwaj,

    2011-06-01

    Full Text Available Fuzzy logic approach for temperature control is adopted for solving these difficulties encountered in conventional PID controller. In this approach temperature error is considered and corresponding firing angle of rectifier is controlled to regulate the power supply inside the temperature control process. The control scheme regulate the power supply in accordance with the difference between set point and desired point .Mamdani fuzzy rule base is considered for controlling the firing angle of the controlled rectifier. Fuzzy chip which consists of microcontroller is the heart of controller, which decides how much power is required by firing the power rectifier.. The control program developed in C language is embedded into the microcontroller. .The rule is made by the operator and accuracy of the system totally depends on the operator data, which is feed in the memory of microcontroller. Result is obtained from the hardware setup and it has been observed in Pico scope, where the change in firing angle versus error voltage, graph is plotted. The hardware is meant for any type of system where precisely temperature controlled is important like industrial processes, chemical mixing, buffer solutionpreparation, etc. Peak overshoot of the temperature is reduced within ±2oc inside the temperature process. Temperature of system is affected by outside environment condition, due to sudden atmospheric change in pressure and temperature.

  9. Temperature control of ion guiding through tapered capillaries

    Energy Technology Data Exchange (ETDEWEB)

    Gruber, Elisabeth, E-mail: egruber@iap.tuwien.ac.at [Institute of Applied Physics, TU Wien – Vienna University of Technology, 1040 Vienna (Austria); Stolterfoht, Nikolaus [Helmholtz-Zentrum Berlin für Materialien und Energie, D-14109 Berlin (Germany); Allinger, Peter; Wampl, Stefan [Institute of Applied Physics, TU Wien – Vienna University of Technology, 1040 Vienna (Austria); Wang, Yuyu [Institute of Applied Physics, TU Wien – Vienna University of Technology, 1040 Vienna (Austria); Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, Gansu (China); Simon, Marius J. [Labor für Ionenstrahlphysik, ETH Zürich, 8093 Zürich (Switzerland); Aumayr, Friedrich, E-mail: aumayr@iap.tuwien.ac.at [Institute of Applied Physics, TU Wien – Vienna University of Technology, 1040 Vienna (Austria)

    2014-12-01

    We investigate the guiding of Ar{sup 7+} ions (kinetic energy of 4.5 keV) through a single macroscopic tapered glass capillary of conical shape as a function of capillary tilt angle with respect to the incident ion beam direction. At room temperature a minimum in the transmitted ion intensity appears around the forward direction, which was previously observed and interpreted by a blocking of the transmission by repulsive Coulomb forces due to a uniformly charged ring shaped region in the centre part of the capillary. By heating the tapered capillary to temperatures around 100 °C and thus drastically increasing the electrical conductivity of the capillary material we no longer observe a minimum in the transmission curve but the transmission curve now has its maximum in forward direction. Since the maximum transmission at high temperature in forward direction is still smaller than the minimum in transmitted intensity at room temperature, we conclude that even at room temperature and in forward direction the focusing effect due to guiding is dominant and only partially weakened by blocking. Our experimental results are well reproduced in simulations using a theoretical model originally developed for straight nano-capillaries.

  10. Method of temperature rising velocity and threshold control of electron beam brazing

    Institute of Scientific and Technical Information of China (English)

    Xuedong Wang; Shun Yao

    2005-01-01

    In order to accommodate electron beam to the brazing of the joints with various curve shapes and the brazing of thermo sensitive materials, the method of electron beam scanning and brazing temperature control was developed, in which electron beam was controlled to scan according to predefined scanning track, and the actual temperature rising velocity of the brazed seam was limited in an allowed scope by detecting the brazed seam temperature, calculating the temperature rising velocity and adjusting the beam current during the brazing process; in addition, through the setting of the highest allowed temperature, the actual temperature of the brazed seam could be controlled not exceeding the threshold set value, and these two methods could be employed alone or jointly. It is shown that high precision temperature control in electron beam brazing could be realized and the productivity be increased by the proposed method.

  11. Temperature-time issues in bioburden control for planetary protection

    Science.gov (United States)

    Clark, Benton C.

    2004-01-01

    Heat energy, administered in the form of an elevated temperature heat soak over a specific interval of time, is a well-known method for inactivating organisms. Sterilization protocols, from commercial pasteurization to laboratory autoclaving, specify both temperature and time, as well as water activity, for treatments to achieve either acceptable reduction of bioburden or complete sterilization. In practical applications of planetary protection, whether to reduce spore load in forward or roundtrip contamination, or to exterminate putative organisms in returned samples from bodies suspected of possible life, avoidance of expensive or potentially damaging treatments of hardware (or samples) could be accomplished if reciprocal relationships between time duration and soak temperature could be established. Conservative rules can be developed from consideration of empirical test data, derived relationships, current standards and various theoretical or proven mechanisms for thermal damage to biological systems.

  12. Temperature Controlled Lateral Pattern Formation in Confined Polymer Thin Films

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hao-li; David G. Bucknall

    2004-01-01

    The thermal induced topography change in a model system consisting of a polymer film on a Si substrate capped by a thin metal layer has been studied by using AFM. Regular lateral patterns over large areas were observed on the surface when the system was heated to a sufficiently high temperature. 2D-FFT analysis to the AFM images indicates that the patterns are isotropic and have well defined periodicities. The periodicities of the characteristic patterns are found to depend strongly on the annealing temperature. The study of the kinetics of the formation reveals that such a topography forms almost instantaneously once the critical temperature is reached. It is suggested that this wave-like surface morphology is driven by the thermal expansion coefficient mismatch of the different layers. This method for generating regular wave-like patterns could be used as a general method for patterning various organic materials into micro/nanostructures.

  13. Low-Temperature Thermochronology Applied to Constrain the Multi-Episodic Thermotectonic Evolution of the Southeastern Continental Margin of Brazil

    Science.gov (United States)

    Mendes, L. D.; Heilbron, M. C. P. L.; Hodges, K. V.; Van Soest, M. C.; Silva, L. G. A. E.

    2015-12-01

    Low-temperature thermochronology was applied to constrain the Mesozoic and Cenozoic tectonic evolution of the continental margin of southeast Brazil. Using apatite (U-Th)/He thermochronology (AHe), we acquired data from 107 crystals of basement samples collected from a NW-SE transect in the Mantiqueira Mountains to the Guanabara Graben, as well as from the NE-SE transverse faults. The data range from 43.5 ± 1.9 Ma to 250.1 ± 8.7 Ma (2 σ) for corrected ages. The Neo-Cretaceous, Eo-Cretaceous, and Paleocene are the main recorded AHe ages, in order of importance. The Eo-Cretaceous ages indicate the occurrence of older thermal events related to a pre-rifting phase (~121 Ma). The Neo-Cretaceous ages signify the importance of tectonic and magmatic events, and regional uplifting for the thermal history of the study area, including ages related to the Serra do Mar Mountains uplift (~86 Ma). Paleocene ages seem to be related to the reactivation (~65 Ma), which was responsible for the continental rifts in the southeastern Brazil. Finally, the Eocene ages (49.7 Ma and 43.5 Ma), which are from samples restricted to the Resende Basin border faults, indicate a continental rift reactivation. Time-temperature (t-T) paths obtained from inverse modeling, performed using HeFTy (Ketcham, 2005) with a Radiation Damage Diffusion and Annealing Model (Flowers et al., 2009), suggests rapid cooling episodes for all samples. The main thermal events show a direct correlation with the timing of regional tectonic events: reactivation phases, continental margin uplift, and the sedimentary record. Apatite (U-Th)/He ages increase with distance from the coast and with elevation. However, these patterns are discontinued by samples of younger ages as a result of the reactivation process of pre-existing structures. The total estimated denudation range from 1.2 to 2.8 km. The erosion rates range from 15.2 to 35.3 m/My. Thus, the multi-episodic thermal events, which led to the formation of important

  14. Method and apparatus for controlling hybrid powertrain system in response to engine temperature

    Energy Technology Data Exchange (ETDEWEB)

    Martini, Ryan D; Spohn, Brian L; Lehmen, Allen J; Cerbolles, Teresa L

    2014-10-07

    A method for controlling a hybrid powertrain system including an internal combustion engine includes controlling operation of the hybrid powertrain system in response to a preferred minimum coolant temperature trajectory for the internal combustion engine.

  15. How light, temperature, and measurement and growth [CO2] interactively control isoprene emission in hybrid aspen

    OpenAIRE

    Niinemets, Ülo; Sun, Zhihong

    2014-01-01

    Summary Isoprene emission is typically modelled using independent controls of light, temperature, and ambient [CO2], assuming these are unaffected by growth [CO2]. We demonstrated strong interactive environmental controls on emissions, calling for profound revision of emission algorithms.

  16. SDRE control strategy applied to a nonlinear robotic including drive motor

    International Nuclear Information System (INIS)

    A robotic control design considering all the inherent nonlinearities of the robot-engine configuration is developed. The interactions between the robot and joint motor drive mechanism are considered. The proposed control combines two strategies, one feedforward control in order to maintain the system in the desired coordinate, and feedback control system to take the system into a desired coordinate. The feedback control is obtained using State-Dependent Riccati Equation (SDRE). For link positioning two cases are considered. Case I: For control positioning, it is only used motor voltage; Case II: For control positioning, it is used both motor voltage and torque between the links. Simulation results, including parametric uncertainties in control shows the feasibility of the proposed control for the considered system

  17. SDRE control strategy applied to a nonlinear robotic including drive motor

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Jeferson J. de, E-mail: jefersonjl82@gmail.com, E-mail: tusset@utfpr.edu.br, E-mail: fcjanzen@utfpr.edu.br, E-mail: piccirillo@utfpr.edu.br, E-mail: claudinor@utfpr.edu.br; Tusset, Angelo M., E-mail: jefersonjl82@gmail.com, E-mail: tusset@utfpr.edu.br, E-mail: fcjanzen@utfpr.edu.br, E-mail: piccirillo@utfpr.edu.br, E-mail: claudinor@utfpr.edu.br; Janzen, Frederic C., E-mail: jefersonjl82@gmail.com, E-mail: tusset@utfpr.edu.br, E-mail: fcjanzen@utfpr.edu.br, E-mail: piccirillo@utfpr.edu.br, E-mail: claudinor@utfpr.edu.br; Piccirillo, Vinicius, E-mail: jefersonjl82@gmail.com, E-mail: tusset@utfpr.edu.br, E-mail: fcjanzen@utfpr.edu.br, E-mail: piccirillo@utfpr.edu.br, E-mail: claudinor@utfpr.edu.br; Nascimento, Claudinor B., E-mail: jefersonjl82@gmail.com, E-mail: tusset@utfpr.edu.br, E-mail: fcjanzen@utfpr.edu.br, E-mail: piccirillo@utfpr.edu.br, E-mail: claudinor@utfpr.edu.br [UTFPR-PONTA GROSSA, PR (Brazil); Balthazar, José M., E-mail: jmbaltha@rc.unesp.br [UNESP-BAURU, SP (Brazil); Brasil, Reyolando M. L. R. da Fonseca, E-mail: reyolando.brasil@ufabc.edu.br [UFABC-SANTO ANDRE, SP (Brazil)

    2014-12-10

    A robotic control design considering all the inherent nonlinearities of the robot-engine configuration is developed. The interactions between the robot and joint motor drive mechanism are considered. The proposed control combines two strategies, one feedforward control in order to maintain the system in the desired coordinate, and feedback control system to take the system into a desired coordinate. The feedback control is obtained using State-Dependent Riccati Equation (SDRE). For link positioning two cases are considered. Case I: For control positioning, it is only used motor voltage; Case II: For control positioning, it is used both motor voltage and torque between the links. Simulation results, including parametric uncertainties in control shows the feasibility of the proposed control for the considered system.

  18. Utilizing Materials With Controllable Curie Temperatures for Magnetic Actuation Purposes

    DEFF Research Database (Denmark)

    Eriksen, Dan; Bahl, Christian R.H.; Smith, Anders;

    2013-01-01

    system. On the basis of forces predicted by the model a number of equilibrium points were calculated for a system where the magnetic force on a ferromagnetic block of material is balanced by a linear spring force. It is shown how these calculation procedures can be used as a tool for designing autonomous......The magnetic force between a permanent magnet and different blocks of ferromagnetic materials was measured and calculated as a function of distance and temperature in the vicinity of the Curie temperature of the materials. The calculations were carried out using a 3-D finite-element model of the...

  19. Thermally induced magnetization switching in Fe/MnAs/GaAs(001): selectable magnetic configurations by temperature and field control.

    Science.gov (United States)

    Spezzani, Carlo; Vidal, Franck; Delaunay, Renaud; Eddrief, Mahmoud; Marangolo, Massimiliano; Etgens, Victor H; Popescu, Horia; Sacchi, Maurizio

    2015-01-01

    Spintronic devices currently rely on magnetization control by external magnetic fields or spin-polarized currents. Developing temperature-driven magnetization control has potential for achieving enhanced device functionalities. Recently, there has been much interest in thermally induced magnetisation switching (TIMS), where the temperature control of intrinsic material properties drives a deterministic switching without applying external fields. TIMS, mainly investigated in rare-earth-transition-metal ferrimagnets, has also been observed in epitaxial Fe/MnAs/GaAs(001), where it stems from a completely different physical mechanism. In Fe/MnAs temperature actually modifies the surface dipolar fields associated with the MnAs magnetic microstructure. This in turn determines the effective magnetic field acting on the Fe overlayer. In this way one can reverse the Fe magnetization direction by performing thermal cycles at ambient temperatures. Here we use element selective magnetization measurements to demonstrate that various magnetic configurations of the Fe/MnAs/GaAs(001) system are stabilized predictably by acting on the thermal cycle parameters and on the presence of a bias field. We show in particular that the maximum temperature reached during the cycle affects the final magnetic configuration. Our findings show that applications are possible for fast magnetization switching, where local temperature changes are induced by laser excitations. PMID:25631753

  20. Thermally induced magnetization switching in Fe/MnAs/GaAs(001): selectable magnetic configurations by temperature and field control

    Science.gov (United States)

    Spezzani, Carlo; Vidal, Franck; Delaunay, Renaud; Eddrief, Mahmoud; Marangolo, Massimiliano; Etgens, Victor H.; Popescu, Horia; Sacchi, Maurizio

    2015-01-01

    Spintronic devices currently rely on magnetization control by external magnetic fields or spin-polarized currents. Developing temperature-driven magnetization control has potential for achieving enhanced device functionalities. Recently, there has been much interest in thermally induced magnetisation switching (TIMS), where the temperature control of intrinsic material properties drives a deterministic switching without applying external fields. TIMS, mainly investigated in rare-earth–transition-metal ferrimagnets, has also been observed in epitaxial Fe/MnAs/GaAs(001), where it stems from a completely different physical mechanism. In Fe/MnAs temperature actually modifies the surface dipolar fields associated with the MnAs magnetic microstructure. This in turn determines the effective magnetic field acting on the Fe overlayer. In this way one can reverse the Fe magnetization direction by performing thermal cycles at ambient temperatures. Here we use element selective magnetization measurements to demonstrate that various magnetic configurations of the Fe/MnAs/GaAs(001) system are stabilized predictably by acting on the thermal cycle parameters and on the presence of a bias field. We show in particular that the maximum temperature reached during the cycle affects the final magnetic configuration. Our findings show that applications are possible for fast magnetization switching, where local temperature changes are induced by laser excitations. PMID:25631753

  1. Research on Control Method for Intermediate Point Temperature of Supercritical Boiler Based on Active Disturbance Rejection Cascade Control

    OpenAIRE

    Junjie Gu; Xiaowei Cao

    2013-01-01

    As the important signal of once-through boiler's water-fuel ratio control, intermediate point temperature of supercritical boiler plays a key role in the decision of steam and water’s boundary, the match of fuel and water, the control of main steam temperature. The condition of its control directly impacts the once-through boiler’s safety and economy running. For an uncertainty model, a good control quality can not be gained using the general PID controller when the unit load has great change...

  2. FPGA-BASED CONTROL OF THERMOELECTRIC COOLERS FOR LASER DIODE TEMPERATURE REGULATION

    Directory of Open Access Journals (Sweden)

    AHTESHAM ALI

    2012-04-01

    Full Text Available The proportional-integral-derivative (PID controller is the most used controller in the industry. Field programmable gate arrays (FPGAs allow efficient implementation of PID controllers. This paper presents the temperature regulation of a 48W laser diode through thermoelectric coolers (TECs. The temperature regulation system is designed and tested. The results demonstrate the feasibility and applicability of PID control through FPGA.

  3. Improved ventilation and temperature control in a nursery

    NARCIS (Netherlands)

    Jacobs, P.

    2011-01-01

    We performed an intervention study in a nursery. We have measured the air quality with as indicator CO2 and temperature in the original configuration. The maximum observed CO2 concentration during a three week monitoring period was 1834 ppm. The average CO2 concentration during the sleeping period w

  4. Supervisory System and Multivariable Control Applying Weighted Fuzzy-PID Logic in an Alcoholic Fermentation Process

    Directory of Open Access Journals (Sweden)

    Márcio Mendonça

    2015-10-01

    Full Text Available In this work, it is analyzed a multivariate system control of an alcoholic fermentation process with no minimum phase. The control is made with PID classic controllers associated with a supervisory system based on Fuzzy Systems. The Fuzzy system, a priori, send set-points to PID controllers, but also adds protection functions, such as if the biomass valued is at zero or very close. The Fuzzy controller changes the campaign to prevent or mitigate the paralyzation of the process. Three control architectures based on Fuzzy Control Systems are presented and compared in performance with classic control in different campaigns. The third architecture, in particular, adds an adaptive function. A brief summary of Fuzzy theory and correlated works will be presented. And, finally simulations results, conclusions and future works end the article.

  5. A systematic approach for fine-tuning of fuzzy controllers applied to WWTPs

    DEFF Research Database (Denmark)

    Ruano, M.V.; Ribes, J.; Sin, Gürkan; Seco, A.; Ferrer, J.

    2010-01-01

    A systematic approach for fine-tuning fuzzy controllers has been developed and evaluated for an aeration control system implemented in a WWTR The challenge with the application of fuzzy controllers to WWTPs is simply that they contain many parameters, which need to be adjusted for different WWTP...... of 33, which improved the quality of the optimization of the control system by a minimization algorithm. Overall the systematic approach considerably improved the performance of the control system as measured by the Integral Absolute Error (deviation between the set-point and the controlled variable...... fine-tune the identifiable parameter subset of the controller. Indeed, the initial location found by Monte-Carlo simulations provided better results than using trial and error approach when identifying parameters of the fuzzy controller. The identifiable subset was reduced to 4 parameters from a total...

  6. Design Fluida Temperature Control in Heat Exchanger using Model Predictive Control Algoritm

    Directory of Open Access Journals (Sweden)

    Fatimah Ekasari Masturi

    2014-03-01

    Full Text Available Heat Exchanger merupakan suatu alat proses pertukaran panas, berfungsi untuk memindahkan panas antara dua fluida yang berbeda temperatur dan dipisahkan oleh suatu sekat pemisah. Pada proses perpindahan panas ini terdapat delay time sehingga dibutuhkan suatu kontroller agar diperoleh temperatur fluida sesuai dengan kriteria yang diinginkan, tidak terdapat energi yang terbuang, serta pemanfaatan sumber energi yang tersedia benar-benar dapat lebih efisien. Model Predictive Control (MPC telah berhasil diaplikasikan di berbagai industri proses, karena kemampuannya untuk mengatasi berbagai masalah multivariabel kontrol seperti interaksi, waktu tunda dan batasan. Keuntungan dari MPC karena kedua variabel, yaitu variabel manipulasi dan variabel kontrol, dihitung dengan menggunakan teknik optimasi. Pengendalian terhadap pendekatan linear plant dengan Kontroler MPC menggunakan parameter Hp (prediksi horizon= 20 Hc(kontrol horizon= 4 matriks pembobot Q=1 R=0.1  dapat menghasilkan respon yang stabil tanpa adanya overshoot serta mampu mencapai setpoint yang diinginkan yaitu 70°C, pada beban tetap (nominal ataupun beban bervariasi sekitar 20 % dari beban nominal dengan waktu steady state 35s.

  7. A Neuro-fuzzy-sliding Mode Controller Using Nonlinear Sliding Surface Applied to the Coupled Tanks System

    Institute of Scientific and Technical Information of China (English)

    Ahcene Boubakir; Fares Boudjema; Salim Labiod

    2009-01-01

    The aim of this paper is to develop a neuro-fuzzy-sliding mode controller (NFSMC) with a nonlinear sliding surface for a coupled tank system.The main purpose is to eliminate the chattering phenomenon and to overcome the problem of the equivalent control computation.A first-order nonlinear sliding surface is presented,on which the developed sliding mode controller (SMC) is based.Mathematical proof for the stability and convergence of the system is presented.In order to reduce the chattering in SMC,a fixed boundary layer around the switch surface is used.Within the boundary layer,where the fuzzy logic control is applied,the chattering phenomenon,which is inherent in a sliding mode control,is avoided by smoothing the switch signal.Outside the boundary,the sliding mode control is applied to drive the system states into the boundary layer.Moreover,to compute the equivalent controller,a feed-forward neural network (NN) is used.The weights of the net are updated such that the corrective control term of the NFSMC goes to zero.Then,this NN also alleviates the chattering phenomenon because a big gain in the corrective control term produces a more serious chattering than a small gain.Experimental studies carried out on a coupled tank system indicate that the proposed approach is good for control applications.

  8. Controlled Start Transmission Wet Clutch Temperature Modeling and Application

    OpenAIRE

    Martinsson, Joel

    2015-01-01

    Controlled Start Transmissions (CST) can be described as a mechanical transmission combined with a wet clutch for controlled torque output. CST:s are commonly used to start up heavy loads for example mining conveyors. Several CST:s can work together to share the load. The transferred torque is controlled by a hydraulic wet clutch which is a proven technology for high torque transfer and low wear. This thesis is a part of a project to increase the knowledge and improve the CST design and contr...

  9. Design New PID like Fuzzy CTC Controller: Applied to Spherical Motor

    Directory of Open Access Journals (Sweden)

    Mohammad shamsodini

    2014-05-01

    Full Text Available The minimum rule base Proportional Integral Derivative (PID Fuzzy Computed Torque Controller with application to spherical motor is presented in this research. The popularity of PID Fuzzy Computed Torque Controller can be attributed to their robust performance in a wide range of operating conditions and partly to their functional simplicity. PID methodology has three inputs and if any input is described with seven linguistic values, and any rule has three conditions we will need 343 rules. It is too much work to write 343 rules and have lots of problem to design embedded control system e.g., Field Programmable Gate Array (FPGA. In this research the PID-like fuzzy controller can be constructed as a parallel structure of a PD-like fuzzy controller and a conventional PI controller to have the minimum rule base and acceptable trajectory follow disturbance to control of spherical motor. However computed torque controller is work based on cancelling decoupling and nonlinear terms of dynamic parameters for each direction of three degree of freedom spherical motor, this controller is work based on motor dynamic model and this technique is highly sensitive to the knowledge of all parameters of nonlinear spherical motor’s dynamic equation. This research is used to reduce or eliminate the computed torque controller problem based on minimum rule base fuzzy logic theory to control of three degrees of freedom spherical motor system and testing of the quality of process control in the simulation environment of MATLAB/SIMULINK Simulator.

  10. Using LDR as Sensing Element for an External Fuzzy Controller Applied in Photovoltaic Pumping Systems with Variable-Speed Drives

    Directory of Open Access Journals (Sweden)

    Geraldo Neves De A. Maranhão

    2015-09-01

    Full Text Available In the present paper, a fuzzy controller applied to a Variable-Speed Drive (VSD for use in Photovoltaic Pumping Systems (PVPS is proposed. The fuzzy logic system (FLS used is embedded in a microcontroller and corresponds to a proportional-derivative controller. A Light-Dependent Resistor (LDR is used to measure, approximately, the irradiance incident on the PV array. Experimental tests are executed using an Arduino board. The experimental results show that the fuzzy controller is capable of operating the system continuously throughout the day and controlling the direct current (DC voltage level in the VSD with a good performance.

  11. Optimized Design of the SGA-WZ Strapdown Airborne Gravimeter Temperature Control System

    Directory of Open Access Journals (Sweden)

    Juliang Cao

    2015-12-01

    Full Text Available The temperature control system is one of the most important subsystems of the strapdown airborne gravimeter. Because the quartz flexible accelerometer based on springy support technology is the core sensor in the strapdown airborne gravimeter and the magnet steel in the electromagnetic force equilibrium circuits of the quartz flexible accelerometer is greatly affected by temperature, in order to guarantee the temperature control precision and minimize the effect of temperature on the gravimeter, the SGA-WZ temperature control system adopts a three-level control method. Based on the design experience of the SGA-WZ-01, the SGA-WZ-02 temperature control system came out with a further optimized design. In 1st level temperature control, thermoelectric cooler is used to conquer temperature change caused by hot weather. The experiments show that the optimized stability of 1st level temperature control is about 0.1 °C and the max cool down capability is about 10 °C. The temperature field is analyzed in the 2nd and 3rd level temperature control using the finite element analysis software ANSYS. The 2nd and 3rd level temperature control optimization scheme is based on the foundation of heat analysis. The experimental results show that static accuracy of SGA-WZ-02 reaches 0.21 mGal/24 h, with internal accuracy being 0.743 mGal/4.8 km and external accuracy being 0.37 mGal/4.8 km compared with the result of the GT-2A, whose internal precision is superior to 1 mGal/4.8 km and all of them are better than those in SGA-WZ-01.

  12. A REVIEW OF INTELLIGENT CONTROL SYSTEMS APPLIED TO THE INVERTED-PENDULUM PROBLEM

    Directory of Open Access Journals (Sweden)

    Pedro Ponce

    2014-01-01

    Full Text Available This study shows the latest advances in the application of intelligent control to the inverted-pendulum problem. A complete review regarding intelligent control design is presented in this study in order to show the most important artificial intelligence methods used for controlling an Inverted-Pendulum. Also this study proposed the use of a neural-fuzzy-with-genetic-algorithms controller for the inverted pendulum problem which gives good results. Conventional controllers are presented in order to observe implementation problems. The study goes deeply in the details that have to take into account in order to understand design problems and limitations.

  13. Design of Synthetic Optimizing Neuro Fuzzy Temperature Controller for Dual Screw Profile Plastic Extruder Using Labview

    Directory of Open Access Journals (Sweden)

    Ravi Samikannu

    2011-01-01

    Full Text Available Problem statement: The temperature control in plastic extrusion machine is an important factor to produce high quality plastic products. The first order temperature control system in plastic extrusion comprises of coupling effects, long delay time and large time constants. Controlling temperature is very difficult as the process is multistage process and the system coupled with each other. In order to conquer this problem the system is premeditated with neuro fuzzy controller using LabVIEW. Approach: The existing technique involved is conventional PID controller, Neural controller, mamdani type Fuzzy Logic Controller and the proposed method is neuro fuzzy controller. Results: Manifest feature of the proposed method is smoothing of undesired control signal of conventional PID, neural controller and mamdani type FLC controller. The software incorporated the LabVIEW graphical programming language and MATLAB toolbox were used to design temperature control in plastic extrusion system. Hence neuro fuzzy controller is most powerful approach to retrieve the adaptiveness in the case of nonlinear system. Conclusion: The tuning of the controller was synchronized with the controlled variable and allowing the process at its desired operating condition. The results indicated that the use of proposed controller improve the process in terms of time domain specification, set point tracking and also reject disturbances with optimum stability.

  14. ROBUST TEMPERATURE CONTROLLER DESIGN FOR A CHEMICAL PROCESS

    Directory of Open Access Journals (Sweden)

    G.Glan Devadhas

    2010-10-01

    Full Text Available This paper attempts to tuning out a new PID control strategy to provide Robust Control for a Chemical process. Chemical process control is a challenging problem due to the strong on-line non-linearity and extreme sensitivity to disturbances of the process. The proposed method has the advantage that it takes into account all the parameters variations associated with the process. The variations in the process parameters are modeled as a gaussian noise and an adaptive gaussian filter is placed in the feedback path. The adaptivegaussian filter in the feedback path adapts its filter coefficients based on a kalman estimation algorithm. This adaptive filter adapts so as to maintain the mean square error a minimum. The LQG (Linear Quadratic Gaussian in Robust Control is used in designing of the proposed strategy. The analysis of a PID tuning [7] strategy and the necessity of such an adaptive strategy is also explored in this paper. The proposed strategy of Robust Control has been designed for a First Order Lag Plus Delay (FOLPD process. The proposed strategy ofRobust Control has been simulated for an FOLPD process in SIMULINK.

  15. Virtual reality applied in the ergonomic evaluation of nuclear power plant control room

    International Nuclear Information System (INIS)

    A nuclear power plant control room is a complex system that controls a nuclear and thermodynamic process used to produce electrical energy. The operators interact with the control room through interfaces that have significant implications to nuclear power plant safety and influence the operator activity. The operator activity presents complexity features and shows a series of mechanisms absents from the human factors guidelines, important to the evaluation and update of control rooms. The ergonomics approach considers the operation strategies, the interaction between the operators, the operator-system interaction, and interaction between operators and support groups. The main objective of this paper is propose the modeling of a nuclear control room, with the support of a game engine core. This tool will be used in the ergonomic evaluation of nuclear control room, generating information and data that will make possible the adequacy of control rooms features to the legal requirements of the regulating agency, assisting the nuclear licensing. (author)

  16. Controlled electropolishing of copper foils at elevated temperature

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Gi Duk; Kim, Young Woo; Moyen, Eric; Keum, Dong Hoon [Department of Energy Science, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Lee, Young Hee [Department of Energy Science, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); IBS Center for Integrated Nanostructure Physics (CINAP), Institute of Basic Science (IBS), Daejeon (Korea, Republic of); Department of Physics, Sungkyunkwan Advanced Institute of Nano-technology (SAINT), Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Baik, Seunghyun [Department of Energy Science, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); School of Mechanical Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); IBS Center for Integrated Nanostructure Physics (CINAP), Institute of Basic Science (IBS), Daejeon (Korea, Republic of); Pribat, Didier, E-mail: didier53@skku.edu [Department of Energy Science, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)

    2014-07-01

    We have studied the electrochemical polishing of copper foils at elevated temperature, in H{sub 3}PO{sub 4} electrolytes of various concentrations. Atomic force microscopy, surface reflectance measurements as well as optical microscopy and scanning electron microscopy (including electron backscattering diffraction) have been used throughout this study to characterize the surface of the electropolished foils. We have found that copper foils electropolished at 65 °C in 2.17 M H{sub 3}PO{sub 4}, exhibited a lower surface roughness and a higher percent specular reflection, comparing with values obtained after classical electropolishing in concentrated H{sub 3}PO{sub 4} at room temperature or comparing with values obtained after chemical-mechanical polishing. This work could open up new prospects for the preparation of copper foils before the growth of high quality graphene layers.

  17. Atmospheric CO2: principal control knob governing Earth's temperature.

    Science.gov (United States)

    Lacis, Andrew A; Schmidt, Gavin A; Rind, David; Ruedy, Reto A

    2010-10-15

    Ample physical evidence shows that carbon dioxide (CO(2)) is the single most important climate-relevant greenhouse gas in Earth's atmosphere. This is because CO(2), like ozone, N(2)O, CH(4), and chlorofluorocarbons, does not condense and precipitate from the atmosphere at current climate temperatures, whereas water vapor can and does. Noncondensing greenhouse gases, which account for 25% of the total terrestrial greenhouse effect, thus serve to provide the stable temperature structure that sustains the current levels of atmospheric water vapor and clouds via feedback processes that account for the remaining 75% of the greenhouse effect. Without the radiative forcing supplied by CO(2) and the other noncondensing greenhouse gases, the terrestrial greenhouse would collapse, plunging the global climate into an icebound Earth state. PMID:20947761

  18. Coolant and ambient temperature control for chillerless liquid cooled data centers

    Science.gov (United States)

    Chainer, Timothy J.; David, Milnes P.; Iyengar, Madhusudan K.; Parida, Pritish R.; Simons, Robert E.

    2016-02-02

    Cooling control methods include measuring a temperature of air provided to a plurality of nodes by an air-to-liquid heat exchanger, measuring a temperature of at least one component of the plurality of nodes and finding a maximum component temperature across all such nodes, comparing the maximum component temperature to a first and second component threshold and comparing the air temperature to a first and second air threshold, and controlling a proportion of coolant flow and a coolant flow rate to the air-to-liquid heat exchanger and the plurality of nodes based on the comparisons.

  19. Evaluation of Air Transportation Under Controlled Room Temperature for Pharmaceuticals

    OpenAIRE

    Badurina, Gordan; Majić, Zvonimir; Pavlin, Stanislav

    2011-01-01

    Pharmaceutical industry like aviation is one of the most regulated industries today. Shipping pharmaceutical products under defined time and temperature conditions is a challenge deriving from regulatory and product quality aspects. Good distribution practice should be valid throughout the distribution chain but regulatory issues are still short of strength in practice. Transportation should be considered as extended warehousing, still compliances are business rather than regulatory driven. T...

  20. Temperature-controlled graphite limiter experiments in CHS plasma

    International Nuclear Information System (INIS)

    A movable graphite limiter with an internal heater has been installed in the heliotron/torsatron type compact helical system (CHS). Comparing discharges with and without the limiter the origin of major impurities and the role of the limiter are discussed. Infrared TV measurements reveal that there are two hot spots on the limiter due to heat loading and their temperatures depend on the elecron density and/or the magnetic field direction. Limiter temperature dependence of measured CH/Hγ, CI, CII, OII, CH3+, OV and total radiation loss is compared. From these experiments it is concluded that CH4 molecules produced chemically on the limiter are presumed to recycle rapidly near the limiter and both carbon and oxygen impurities result probably from CO produced chemically on the limiter with oxygen which is predominant in CHS and originiates mostly from the first wall. At surface temperatures above 900deg C the limiter effect on impurities is observable in the main plasma. (orig.)

  1. On-Chip Hotplate for Temperature Control of Cmos Saw Resonators

    CERN Document Server

    Nordin, Anis; Zaghloul, Mona

    2008-01-01

    Due to the sensitivity of the piezoelectric layer in surface acoustic wave (SAW) resonators to temperature, a method of achieving device stability as a function of temperature is required. This work presents the design, modeling and characterization of integrated dual-serpentine polysilicon resistors as a method for temperature control of CMOS SAW resonators. The design employs the oven control temperature stabilization scheme where the device's temperature is elevated to higher than Tmax to maintain constant device temperature. The efficiency of the polysilicon resistor as a heating element was verified through a 1-D partial differential equation model, 3-D CoventorWare finite element simulations and measurements using Compix thermal camera. To verify that the on-chip hotplate is effective as a temperature control method, both DC and RF measurements of the heater together with the resonator were conducted. Experimental results have indicated that the TCF of the CMOS SAW resonator of -97.2 ppm/deg C has been ...

  2. Distributed Active Traction Control System Applied to the RoboCup Middle Size League

    Directory of Open Access Journals (Sweden)

    José Almeida

    2013-10-01

    Full Text Available This work addresses the problem of traction control in mobile wheeled robots in the particular case of the RoboCup Middle Size League (MSL. The slip control problem is formulated using simple friction models for ISePorto Team Robots with a differential wheel configuration. Traction was also characterized experimentally in the MSL scenario for relevant game events. This work proposes a hierarchical traction control architecture which relies on local slip detection and control at each wheel, with relevant information being relayed to a higher level responsible for global robot motion control. A dedicated one axis control embedded hardware subsystem allowing complex local control, high frequency current sensing and odometric information procession was developed. This local axis control board is integrated in a distributed system using CAN bus communications. The slipping observer was implemented in the axis control hardware nodes integrated in the ISePorto Robots and was used to control and detect loss of traction. An external vision system was used to perform a qualitative analysis of the slip detection and observer performance results are presented.

  3. Method of controlling temperature of a thermoelectric generator in an exhaust system

    Science.gov (United States)

    Prior, Gregory P; Reynolds, Michael G; Cowgill, Joshua D

    2013-05-21

    A method of controlling the temperature of a thermoelectric generator (TEG) in an exhaust system of an engine is provided. The method includes determining the temperature of the heated side of the TEG, determining exhaust gas flow rate through the TEG, and determining the exhaust gas temperature through the TEG. A rate of change in temperature of the heated side of the TEG is predicted based on the determined temperature, the determined exhaust gas flow rate, and the determined exhaust gas temperature through the TEG. Using the predicted rate of change of temperature of the heated side, exhaust gas flow rate through the TEG is calculated that will result in a maximum temperature of the heated side of the TEG less than a predetermined critical temperature given the predicted rate of change in temperature of the heated side of the TEG. A corresponding apparatus is provided.

  4. A predictive current control applied to a permanent magnet synchronous machine, comparison with a classical direct torque control

    Energy Technology Data Exchange (ETDEWEB)

    Morel, Florent; Lin-Shi, Xuefang; Retif, Jean-Marie; Allard, Bruno [AMPERE, INSA de Lyon, 20, avenue Albert Einstein, 69621 Villeurbanne cedex (France)

    2008-08-15

    This paper presents a new predictive current control (PCC) for permanent magnet synchronous machines (PMSM) drivers. Based on a hybrid model including an inverter model and a PMSM model, the proposed scheme selects more than one inverter configuration and allows to reach exactly the reference state vector. It appears attractive when compared to conventional direct torque control (DTC). Hysteresis comparators are not used. The switching frequency is fixed and it does not have to be very high. The control scheme has been verified experimentally with a 1.6 kW PMSM drive. Comparative studies with DTC control are performed with the same test bench. The results show that the proposed control obtains the same fast torque dynamics if not better than DTC control schemes but with smaller ripples. (author)

  5. Refractory porcelain enamel passive-thermal-control coating for high-temperature superalloys

    Science.gov (United States)

    Levin, H.; Auker, B. H.; Gardos, M. N.

    1973-01-01

    Study was conducted to match thermal expansion coefficients thereby preventing enamels from cracking. Report discusses various enamel coatings that are applied to two different high-temperature superalloys. Study may be of interest to manufacturers of chemical equipment, furnaces, and metal components intended for high-temperature applications.

  6. Lay out, test verification and in orbit performance of HELIOS a temperature control system

    Science.gov (United States)

    Brungs, W.

    1975-01-01

    HELIOS temperature control system is described. The main design features and the impact of interactions between experiment, spacecraft system, and temperature control system requirements on the design are discussed. The major limitations of the thermal design regarding a closer sun approach are given and related to test experience and performance data obtained in orbit. Finally the validity of the test results achieved with prototype and flight spacecraft is evaluated by comparison between test data, orbit temperature predictions and flight data.

  7. Interactions between controlled atmospheres and low temperature tolerance: A review of biochemical mechanisms

    OpenAIRE

    JesperGivskovSørensen; ShelleyAJohnson

    2011-01-01

    Controlled atmosphere treatments using carbon dioxide, oxygen, and/or nitrogen, together with controlled temperature and humidity, form an important method for post-harvest sterilization against insect-infested fruit. However, in insects, the cross tolerance and biochemical interactions between the various stresses of modified gas conditions and low temperature may either elicit or block standard stress responses which can potentiate (or limit) lethal low temperature exposure. Thus, the succe...

  8. Sequential Adaptive RBF-Fuzzy Variable Structure Control Applied to Robotics Systems

    Directory of Open Access Journals (Sweden)

    Mohammed Salem

    2014-08-01

    Full Text Available In this paper, we present a combination of sequential trained radial basis function networks and fuzzy techniques to enhance the variable structure controllers dedicated to robotics systems. In this aim, four RBFs networks were used to estimate the model based part parameters (Inertia, Centrifugal and Coriolis, Gravity and Friction matrices of a variable structure controller so to respond to model variation and disturbances, a sequential online training algorithm based on Growing-Pruning "GAP" strategy and Kalman filter was implemented. To eliminate the chattering effect, the corrective control of the VS control was computed by a fuzzy controller. Simulations are carried out to control three degrees of freedom SCARA robot manipulator where the obtained results show good disturbance rejection and chattering elimination.

  9. Preventing Control Constraint Violations by Use of Energy Balances for a Class of Coupled Systems: Applied to a Power Plant

    DEFF Research Database (Denmark)

    Odgaard, Peter Fogh; Stoustrup, Jakob

    2007-01-01

    In this paper a scheme is presented for preventing violations of control signal constraints in a class of coupled systems. The scheme is an add-on solution to the existing control system; it works like a fault tolerant scheme, by accommodating the problem then occurring. The proposed scheme recom...... and not to optimize performance during all conditions. The scheme is applied to an example with a coal mill pulverizing coal for a power plant.  ...

  10. Micro controller based design of digital transmitters for temperature measurements in reactors

    International Nuclear Information System (INIS)

    Temperature transmitter is one of the most important transmitters in the nuclear reactor it is used for RTD (resistance temperature detector) signal conditioning. It has built-in current excitation, instrumentation amplifier, linearization and current output circuitry which amplifies the RTD signal and gives linearization to it. It is a part of a system to get temperature and monitoring it. This system is very cost and complicated. In this work a digital system is implemented by using micro controller techniques that replaces the existing system, one chip (PIC16f877) is used to build a digital system, which is more accurate and give more performance and low costs . RTD is the sensing element of temperature, its resistance increases with temperature. There are many types of transmitters in the reactor such as temperature, pressure, level and flow but temperature one is chosen because of temperature is one of the most important parameters in process control.

  11. Maximum Principle for Linear-Convex Boundary Control Problems applied to Optimal Investment with Vintage Capital

    OpenAIRE

    Faggian, Silvia

    2007-01-01

    The paper concerns the study of the Pontryagin Maximum Principle for an infinite dimensional and infinite horizon boundary control problem for linear partial differential equations. The optimal control model has already been studied both in finite and infinite horizon with Dynamic Programming methods in a series of papers by the same author, or by Faggian and Gozzi. Necessary and sufficient optimality conditions for open loop controls are established. Moreover the co-state variable is shown t...

  12. Efficiency of particle swarm optimization applied on fuzzy logic DC motor speed control

    Directory of Open Access Journals (Sweden)

    Allaoua Boumediene

    2008-01-01

    Full Text Available This paper presents the application of Fuzzy Logic for DC motor speed control using Particle Swarm Optimization (PSO. Firstly, the controller designed according to Fuzzy Logic rules is such that the systems are fundamentally robust. Secondly, the Fuzzy Logic controller (FLC used earlier was optimized with PSO so as to obtain optimal adjustment of the membership functions only. Finally, the FLC is completely optimized by Swarm Intelligence Algorithms. Digital simulation results demonstrate that in comparison with the FLC the designed FLC-PSO speed controller obtains better dynamic behavior and superior performance of the DC motor, as well as perfect speed tracking with no overshoot.

  13. Applying human factors to the design of control centre and workstation of a nuclear reactor

    International Nuclear Information System (INIS)

    Human factors is a body of scientific factors about human characteristics, covering biomedical, psychological and psychosocial considerations, including principles and applications in the personnel selection areas, training, job performance aid tools and human performance evaluation. Control Centre is a combination of control rooms, control suites and local control stations which are functionally related and all on the same site. Digital control room includes an arrangement of systems, equipment such as computers and communication terminals and workstations at which control and monitoring functions are conducted by operators. Inadequate integration between control room and operators reduces safety, increases the operation complexity, complicates operator training and increases the likelihood of human errors occurrence. The objective of this paper is to present a specific approach for the conceptual and basic design of the control centre and workstation of a nuclear reactor used to produce radioisotope. The approach is based on human factors standards, guidelines and the participation of a multidisciplinary team in the conceptual and basic phases of the design. Using the information gathered from standards and from the multidisciplinary team, an initial sketch 3D of the control centre and workstation are being developed. (author)

  14. Experiences in control system design aided by interactive computer programs: temperature control of the laser isotope separation vessel

    International Nuclear Information System (INIS)

    A robust control system has been designed to regulate temperature in a vacuum vessel. The thermodynamic process is modeled by a set of nonlinear, implicit differential equations. The control design and analysis task exercised many of the computer-aided control systems design software packages, including MATLAB, DELIGHT, and LSAP. The working environment is a VAX computer. Advantages and limitations of the software and environment, and the impact on final controller design is discussed

  15. Studies relating to temperature control of a large scale telescope

    Science.gov (United States)

    Katzoff, S.

    1973-01-01

    Analytical methods are developed for estimating the circumferential and longitudinal temperature distributions in a large space telescope, idealized as a simple insulated tube with a flat mirror across one end. The effects of wall conduction, multilayer insulation, thermal coatings, heat pipes, and heated collars are analyzed, with numerical examples. For most of the study, the only thermal input to the tube was assumed to be from steady solar irradiation from one side, as in a geosynchronous orbit. Unsteady heat flow through the insulation, as in alternating sunlight and shadow of a low orbit, is briefly discussed.

  16. Control of reactor inlet header temperature (RIHT) rise in CANDU

    International Nuclear Information System (INIS)

    Fouling of tube surfaces in a CANDU steam generator is analyzed using a mathematical model and is shown to account for a major portion of the observed Reactor Inlet Header Temperature (RIHT) rise. First, a detailed heat transfer model is made to account for tube wall temperature at every point along a tube, then the solubility of magnetite is calculated at that wall temperature to check for primary side fouling. Once fouling can occur by magnetite crystal growth on the wall, the rate of fouling is determined by the mass transfer of dissolved iron from the water to the tube surface. The fouling deposit increases heat transfer resistance and thus the heavy water outlet temperature (RIHT) rises. This rise is followed through time and a detailed prediction of deposit weight profiles expected in the tubes is made. The inlet dissolved iron concentration to the boiler is calculated by using a simple flow-assisted corrosion model of outlet feeders. Primary side fouling of the boiler tubes is predicted to be a major contributor to RIHT rise. Coolant pH has a strong effect on flow-assisted corrosion of the outlet feeders and thus on the amount of iron entering the boilers. Deposit weights are predicted accurately for both Gentilly-2 (G-2) and Pickering-1 steam generators using solubility data from Sweeton and Baes at pH 10.3 or 1.4 mg/kg Li. Operation at the low end of the specified pH range seems desirable, e.g. 0.35 mg Li/kg, to reduce the fouling rate of the boiler tubes. Secondary side fouling is predicted to be equally important, but deposit data specific to each plant are needed to assess the precise contribution of this to RIHT rise. A gradual rise in primary side steam quality at the boiler inlet due to RIHT rise will itself generate an RIHT rise simply due to a reduction in boiler area available for sensible heat transfer. Finally, mechanical effects such as divider plate leakage and changes in primary side flow due to pressure tube creep and to increased surface

  17. A furnace and temperature controller for optical absorption studies with a spectrophotometer

    International Nuclear Information System (INIS)

    The design and main features of a furnace with a temperature controller and programmer are shown. This system allows to measure the optical absorption spectrum of a sample from room temperature to 400 deg C, in a double beam spectrophotometer Perkin Elmer 350. The sample temperature can be linearly increased at different heating rates between 4 and 38 deg C/min. The temperature ramp can be stopped at any desired point and the sample temperature shall be stabilized in less than one minute. This temperature shall be kept constant within 0.5 deg C for hours. The sample is heated in vacuum. (author)

  18. Heliostat-field gain-scheduling control applied to a two-step solar hydrogen production plant

    International Nuclear Information System (INIS)

    Highlights: ► A control system is proposed for a solar reactor system which produces hydrogen. ► The controller chooses which heliostats from the solar field must be focused. ► A gain scheduling scheme is included to deal with different system dynamics. ► The scheme is tested and tunned in simulation. ► Real experiments show the promising results of this work. -- Abstract: This article describes a temperature control structure designed for the interior of a solar hydrogen reactor based on a two-step ferrite-redox technology. Until now, this temperature has been controlled by manual selection of the heliostats to be focused on the receiver targets. However, the strong system dependency on operating conditions suggests that the procedure be automated in order to ensure the desired setpoint change response. The aims are to maintain the desired temperatures and to make the setpoint switch as fast as possible, keeping plant conditions within the margins of safety. The scheme proposed includes a procedure for selecting the heliostats to be focused on the reactor by using a simple model of the solar field and a gain scheduling control system which changes the control tuning parameters to deal with the varying dynamics observed during the process. Real experiments show the promising results of this work.

  19. Apply Pesticides Correctly, A Guide for Commercial Applicators: Aquatic Pest Control.

    Science.gov (United States)

    Wamsley, Mary Ann, Ed.; Vermeire, Donna M., Ed.

    This guide presents information needed to meet the requirements for pesticide applicator certification. The first part deals with recognition and control of aquatic pests such as aquatic weeds, fish and other vertebrates. Environmental concerns in aquatic pest control are discussed in the second section. (CS)

  20. Evaluation of Linear and Non-Linear Control Schemes Applied to a Hydraulic Servo System

    DEFF Research Database (Denmark)

    Andersen, Torben Ole; Hansen, Michael Rygaard; Pedersen, Henrik Clemmensen

    2005-01-01

    Due to the innovation of low-cost electronics such as sensors, microcontrollers etc., the focus on highperformance motion control is increasing. This work focuses on position control of single-input single-output hydraulic servo-systems in general. A hydraulically actuated robotic manipulator...