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Sample records for on-line partial discharge

  1. Solving of some Problems with On-Line Mode Measurement of Partial Discharges

    Karel Zalis

    2004-01-01

    Full Text Available This paper deals with the problems discussing the transition from off-line diagnostic methods to on-line ones. Based on the experience with commercial partial discharge measuring equipment a new digital system for the evaluation of partial discharge measurement including software and hardware facilities has been developed at the Czech Technical University in Prague. Two expert systems work in this complex evaluating system: a rule-based expert system performing an amplitude analysis of partial discharge impulses for determining the damage of the insulation system, and a neural network which is used for a phase analysis of partial discharge impulses to determine the kind of partial discharge activity. Problem of the elimination of disturbances is also discussed.

  2. On-line Monitoring Device for High-voltage Switch Cabinet Partial Discharge Based on Pulse Current Method

    Y Tao, S.; Zhang, X. Z.; Cai, H. W.; Li, P.; Feng, Y.; Zhang, T. C.; Li, J.; Wang, W. S.; Zhang, X. K.

    2017-12-01

    The pulse current method for partial discharge detection is generally applied in type testing and other off-line tests of electrical equipment at delivery. After intensive analysis of the present situation and existing problems of partial discharge detection in switch cabinets, this paper designed the circuit principle and signal extraction method for partial discharge on-line detection based on a high-voltage presence indicating systems (VPIS), established a high voltage switch cabinet partial discharge on-line detection circuit based on the pulse current method, developed background software integrated with real-time monitoring, judging and analyzing functions, carried out a real discharge simulation test on a real-type partial discharge defect simulation platform of a 10KV switch cabinet, and verified the sensitivity and validity of the high-voltage switch cabinet partial discharge on-line monitoring device based on the pulse current method. The study presented in this paper is of great significance for switch cabinet maintenance and theoretical study on pulse current method on-line detection, and has provided a good implementation method for partial discharge on-line monitoring devices for 10KV distribution network equipment.

  3. On-line Monitoring System Based on Principle of Electro-acoustic Monitoring for Transformer Partial Discharge

    Guang Ya LIU

    2014-02-01

    Full Text Available Partial discharge inside a transformer is mainly responsible for the insulation aging and damage of the transformer. However, partial discharge is usually accompanied by external signals like sound, light and electrical signals and detectable physical phenomena such as characteristical gas and dielectric loss. Therefore, it is of great significance to monitor online the external signals and phenomena formed during partial discharge of the transformer when the transformer diagnoses faults. This paper gives a comprehensive overview of the electro-acoustic joint monitoring principles and its monitoring systems and the judgment skills concerned, on the basis of which the monitoring system is designed.

  4. Fundamental aspects of excitation and propagation of on-line partial discharge signals in three-phase medium voltage cable systems

    Wielen, van der P.C.J.M.; Steennis, E.F.; Wouters, P.A.A.F.

    2003-01-01

    On-line partial discharge (PD) detection of three-phase belted medium voltage cable connections results in a number of interpretation differences as compared to off-line measurements where only one phase is energized. The induced currents and charges in the phase conductors and earth screen upon a

  5. Development of method for detecting signs deterioration in insulator of high-voltage motors. 2. Test Results of a new on-line partial discharge monitor for high-voltage motors in nuclear power stations

    Tochio, Atsushi; Kaneda, Yoshiharu; Urakawa, Nobuo

    2000-01-01

    For the purpose of early detection of deterioration of insulators in high-voltage motors which are widely utilized in nuclear power stations, a new on-line partial discharge (PD) monitor was developed and was tested for sixteen motors which were practically running in nuclear power stations. From the test results, it is seen that (1) good signal to noise ratio is obtained by adopting a two frequency correlation method, (2) a resistance temperature detector (RTD) in a motor has sufficient sensitivity to detect PD, (3) when RTD is not installed or is unable to use for this purpose, a radio frequency current transformer (RFCT) can be utilized, although its sensitivity is about 1/10 of that of the RTD monitor. Finally we found a good correlation between the results of this on-line method and the conventional off-line method in which the insulator resistance of a concerned motor was measured during its shut-down, and thereby we demonstrated that this method could be applicable to the on-line test of high-voltage motors in nuclear power stations. (author)

  6. On-line diagnosis of high power motors based on ultra wide band partial discharge detection; Diagnostico en linea de motores de gran capacidad mediante la deteccion de descargas parciales utilizando tecnicas de banda ultra ancha

    Carvajal M, F. Antonio; Garcia Colon H, Vicente R. [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico); Asiain, Tomas [Instituto Politecnico Nacional, Escuela Superior de Ingenieria Mecanica y Electrica (Mexico)

    2009-07-01

    In this work a non-standardized method for on-line diagnostic of high capacity motors based on Ultra Wide Band (UWB) Partial Discharge (PD) measuring techniques is theoretically supported, implemented and applied. The method developed is non invasive and consist in the measurement of PD in the main motor power supply cables and its ground shields connection using a near field sensor (Rogowski coil, clamp-on type) with a bandwidth of 2 to 40 MHz. The measured signals by the sensor, are stretched electronically, digitized and fed to a conventional Partial Discharge digital detector. The UWB PD detection system used displays the output in a Pulse repetition frequency-Charge-Phase angle (N-Q-?) PD pattern. The results obtained in thirteen 2500 H.P., 13.8 kV motors performed during operating in an Oil Pumping facility are presented, including its analysis and comparison with values and PD patterns reported in literature. [Spanish] En este trabajo se presentan los fundamentos teoricos, la implementacion y aplicacion de un metodo no normalizado, para el diagnostico en linea de motores de gran capacidad, basado en la deteccion de Descargas Parciales (DP) utilizando tecnicas de medicion de Banda Ultra Ancha. El metodo desarrollado es no invasivo y consiste en la medicion de las DP en los conductores y conexiones a tierra de la pantalla de los cables principales de suministro de energia al motor, utilizando un sensor de campo cercano (bobina Rogowski, tipo gancho) cuyo ancho de banda de medicion es de 2 a 40 MHz. Las senales medidas por el sensor son electronicamente procesadas para ampliar su duracion, digitalizadas y enviadas a un detector digital de Descargas Parciales convencional. El sistema de deteccion de DP en Banda Ultra Ancha despliega la medicion en un patron de DP tipo frecuencia de repeticion de Pulso-Carga-Angulo de fase (N-Q-?). Se presentan los resultados obtenidos de la evaluacion en linea de trece motores de 2500 C.P. a 13.8 kV, instalados y operando en una

  7. Development of Partial Discharging Simulation Test Equipment

    Kai, Xue; Genghua, Liu; Yan, Jia; Ziqi, Chai; Jian, Lu

    2017-12-01

    In the case of partial discharge training for recruits who lack of on-site work experience, the risk of physical shock and damage of the test equipment may be due to the limited skill level and improper operation by new recruits. Partial discharge simulation tester is the use of simulation technology to achieve partial discharge test process simulation, relatively true reproduction of the local discharge process and results, so that the operator in the classroom will be able to get familiar with and understand the use of the test process and equipment.The teacher sets up the instrument to display different partial discharge waveforms so that the trainees can analyze the test results of different partial discharge types.

  8. Partial discharges and bulk dielectric field enhancement

    McAllister, Iain Wilson; Johansson, Torben

    2000-01-01

    A consequence of partial discharge activity within a gaseous void is the production of a field enhancement in the solid dielectric in the proximity of the void. This situation arises due to the charge created by the partial discharges accumulating at the void wall. The influence of the spatial...

  9. Partial discharge transients: The field theoretical approach

    McAllister, Iain Wilson; Crichton, George C

    1998-01-01

    Up until the mid-1980s the theory of partial discharge transients was essentially static. This situation had arisen because of the fixation with the concept of void capacitance and the use of circuit theory to address what is in essence a field problem. Pedersen rejected this approach and instead...... began to apply field theory to the problem of partial discharge transients. In the present paper, the contributions of Pedersen using the field theoretical approach will be reviewed and discussed....

  10. A novel technique for partial discharge measurement

    Farrokh, Fattahi; Navid, Tagizadegan; Ahmad, Zentabchi; Mehdi, Rashidi

    2005-01-01

    Full text : Partial discharges are a sensitive measure of local electrical stress and therefore the measurements is very often used as a quality check of the insulation. The inception of partial discharges gives information on the limit of the electrical strength of the insulating material before a complete discharge between the conductors takes place. Therefore the insulating material can be tested with high stress but without damaging or reducing the performance of the insulation. Also, for partial discharge measurements it should be taken into account that every stress of the insulation will have an influence on the life expectancy of the material, but a reasonable compromise between the stress during the measurement in order to get reliable results and the influence of he lifetime should be found and established in the relevant standard for the particular equipment, for example transformers, cables and so on

  11. Partial discharges in ellipsoidal and spheroidal voids

    Crichton, George C; Karlsson, P. W.; Pedersen, Aage

    1989-01-01

    Transients associated with partial discharges in voids can be described in terms of the charges induced on the terminal electrodes of the system. The relationship between the induced charge and the properties which are usually measured is discussed. The method is illustrated by applying it to a s......Transients associated with partial discharges in voids can be described in terms of the charges induced on the terminal electrodes of the system. The relationship between the induced charge and the properties which are usually measured is discussed. The method is illustrated by applying...

  12. Partial discharge testing of in-situ power cable accessories

    Orban, H. E.

    2002-07-01

    An overview of commercially available diagnostic methods for in-situ power cable accessories is given and relevant field experiences with these diagnostics are described. The discussion includes both PILC and polymeric insulated cables. Two major types of degradation are most frequently involved in cable systems. One is an overall condition caused by chemical aging and /or water treeing. Diagnostics for this type of aging include dissipation factor (loss angle), harmonic analysis, return voltage, isothermal relaxation current, dielectric response, or dc leakage current. The second type of degradation is discrete or incremental; condition assessment utilizes dissipation factor measurements or partial discharge (PD) level measurements. The focus in this paper is on PD diagnostics, especially off-line methods such as the 60 Hz test, the combined AC and VLF diagnostic, and the oscillating wave test system test. Among on-line diagnostics, ultrasonic detection of partial discharge and measurement of partial discharge by installing direct, capacitive or inductive couplers near cable accessories, are described. Overall, partial discharge detection and location in cable accessories is considered inadequate, since interpretation of results is difficult due to the number of variables involved. 28 refs., 1 tab.

  13. Partial discharges in spheroidal voids: Void orientation

    McAllister, Iain Wilson

    1997-01-01

    Partial discharge transients can be described in terms of the charge induced on the detecting electrode. The influence of the void parameters upon the induced charge is examined and discussed for spheroidal voids. It is shown that a quantitative interpretation of the induced charge requires...

  14. Application to the system of insulated of diagnosis in high-voltage motors by partial discharge

    Mikami, M.

    2005-01-01

    In order to detect electric insulators degradation of high-voltage electric motors at an early stage, measurements of partial discharge of operating high-voltage electric motors (about 150 units) in the nuclear power plants were conducted from 2001 to 2004 by the use of on-line monitoring systems that could measure partial discharge of electric insulators. Influencing factors for measured values were identified from measured data and evaluation criteria of electric insulators integrity were established based on variations of partial discharge values. (T. Tanaka)

  15. Evaluation of deterioration of insulators in high-voltage motors by partial discharge

    Mikami, Masao

    2003-01-01

    For the purpose of early detection of deterioration of insulators in high-voltage motors which are widely utilized in nuclear power stations, a new type on-line partial discharge monitor developed at INSS was applied to test the deterioration of about 150 sets of high-voltage motors running in nuclear power stations practically. From the results, it is shown that (1) tendency of the deterioration can be obtained by this method in general, (2) the magnitude of the on-line partial discharge hardly correlates with that of off-line measurement, but depends on temperature and other environmental conditions, and (3) by observing phase characteristics of partial discharge, it is possible to make a diagnosis of phase-to-phase tracking in end-winding coils of a stator. (author)

  16. Ultrasonic partial discharge monitoring method on instrument transformers

    Kartalović Nenad

    2012-01-01

    Full Text Available Sonic and ultrasonic partial discharge monitoring have been applied since the early days of these phenomena monitoring. Modern measurement and partial discharge acoustic (ultrasonic and sonic monitoring method has been rapidly evolving as a result of new electronic component design, information technology and updated software solutions as well as the development of knowledge in the partial discharge diagnosis. Electrical discharges in the insulation system generate voltage-current pulses in the network and ultrasonic waves that propagate through the insulation system and structure. Amplitude-phase-frequency analysis of these signals reveals information about the intensity, type and location of partial discharges. The paper discusses the possibility of ultrasonic method selectivity improvement and the increase of diagnosis reliability in the field. Measurements were performed in the laboratory and in the field while a number of transformers were analysed for dissolved gases in the oil. A comparative review of methods for the partial discharge detection is also presented in this paper.

  17. Partial discharge transients and the influence of dielectric polarization

    Pedersen, A.; Crichton, George C; McAllister, Iain Wilson

    1996-01-01

    Based on a field-theoretical approach, a physically valid theory of partial discharge transients has been developed. The theory is based upon the concept of the charge induced upon the detecting electrode by the partial discharge. This induced charge is shown to be composed of a component...

  18. The theory and measurement of partial discharge transients

    Pedersen, Aage; Crichton, George C; McAllister, Iain Wilson

    1991-01-01

    A theoretical approach to partial discharge transients is presented. This approach is based on the relationship between the charge induced on the measurement electrode by those created in the interelectrode volume during partial discharge activity. The primary sources for these induced charges ar...... electrode systems of practical interest is illustrated. A discussion of the salient features and practical aspects of the theory is included...

  19. Study and optimization of the partial discharges in capacitor model ...

    that the main cause of failure of these devices is the appearance of partial discharges initiated on edges of armatures. These devices can quickly slam if discharges occur continuously during the liquid impregnation. One of the criteria for selecting impregnating liquids is the behavior of gas bubbles when discharges occur.

  20. Investigation of gas discharge ion sources for on-line mass separation

    Kirchner, R.

    1976-03-01

    The development of efficient gas discharge ion sources with axial beam extraction for on-line mass separation is described. The aim of the investigation was to increase the ion source temperature, the lifetime and the ionisation yield in comparison to present low-pressure are discharge ion sources and to reduce the ion current density from usually 1 to 100 mA/cm 3 . In all ion sources the pressure range below the minimal ignition pressure of the arc discharge was investigated. As a result an ion source was developed which works at small changes in geometry and in electric device of a Nielsen source with high ionization yield (up to 50% for xenon) stabil and without ignition difficulties up to 10 -5 Torr. At a typical pressure of 3 x 10 -5 Torr ion current and ion current density are about 1 μA and 0.1 mA/cm 3 respectively besides high yield and a great emission aperture (diameter 1.2 mm). (orig.) [de

  1. Computer-based instrumentation for partial discharge detection in GIS

    Md Enamul Haque; Ahmad Darus; Yaacob, M.M.; Halil Hussain; Feroz Ahmed

    2000-01-01

    Partial discharge is one of the prominent indicators of defects and insulation degradation in a Gas Insulated Switchgear (GIS). Partial discharges (PD) have a harmful effect on the life of insulation of high voltage equipment. The PD detection using acoustic technique and subsequent analysis is currently an efficient method of performing non-destructive testing of GIS apparatus. A low cost PC-based acoustic PD detection instrument has been developed for the non-destructive diagnosis of GIS. This paper describes the development of a PC-based instrumentation system for partial discharge detection in GIS and some experimental results have also presented. (Author)

  2. An on-line monitoring system for a micro electrical discharge machining (micro-EDM) process

    Liao, Y S; Chang, T Y; Chuang, T J

    2008-01-01

    A pulse-type discriminating system to monitor the process of micro electrical discharge machining (micro-EDM) is developed and implemented. The specific features are extracted and the pulses from a RC-type power source are classified into normal, effective arc, transient short circuit and complex types. An approach to discriminate the pulse type according to three durations measured at three pre-determined voltage levels of a pulse is proposed. The developed system is verified by using simulated signals. Discrimination of the pulse trains in actual machining processes shows that the pulses are mainly the normal type for micro wire-EDM and micro-EDM milling. The pulse-type distribution varies during the micro-EDM drilling process. The percentage of complex-type pulse increases monotonically with the drilling depth. It starts to drop when the gap condition is seriously deteriorated. Accordingly, an on-line monitoring strategy for the micro-EDM drilling process is proposed

  3. Study and optimization of the partial discharges in capacitor model ...

    The initial potential as well as the temperature are known to influence the partial discharge ... The development of electrostatic industry has ... the liquid impregnation. One of the ..... the Surface of Corona charged Uniforms layers of HIPS.

  4. Partial Discharge Phase Distribution Of Palm Oil As Insulating Liquid

    Abdul Rajab

    2011-04-01

    Full Text Available Due to the low biodegradability level of mineral oil and its susceptibility to the fire, palm oil was proposed as alternative insulating liquid. This paper discusses partial discharge (PD in palm oil under sinusoidal voltages and the comparison with mineral oil. PD was generated using a needle-plane electrode configuration which is enable enhancing electric field at the needle tip. PD pulses were detected using RC detector and they were measured using a Computer-based partial discharge measurement system. The results showed that PD activities in both oils are similar. The PD was initiated at the negative polarity of applied voltage. The discharges took place in both polarity’s of applied voltage with PD number was higher at negative one. Several discharges phenomena showed the presence of space charge which changed electric field and governed PD activities besides the main field introduced by voltage application.

  5. SVM-based Partial Discharge Pattern Classification for GIS

    Ling, Yin; Bai, Demeng; Wang, Menglin; Gong, Xiaojin; Gu, Chao

    2018-01-01

    Partial discharges (PD) occur when there are localized dielectric breakdowns in small regions of gas insulated substations (GIS). It is of high importance to recognize the PD patterns, through which we can diagnose the defects caused by different sources so that predictive maintenance can be conducted to prevent from unplanned power outage. In this paper, we propose an approach to perform partial discharge pattern classification. It first recovers the PRPD matrices from the PRPD2D images; then statistical features are extracted from the recovered PRPD matrix and fed into SVM for classification. Experiments conducted on a dataset containing thousands of images demonstrates the high effectiveness of the method.

  6. Study and optimization of the partial discharges in capacitor model ...

    Page 1 ... experiments methodology for the study of such processes, in view of their modeling and optimization. The obtained result is a mathematical model capable to identify the parameters and the interactions between .... 5mn; the next landing is situated in 200 V over the voltage of partial discharges appearance and.

  7. A Modular Approach for Teaching Partial Discharge Phenomenon through Experiment

    Chatterjee, B.; Dey, D.; Chakravorti, S.

    2011-01-01

    Partial discharge (PD) monitoring is an effective predictive maintenance tool for electrical power equipment. As a result, an understanding of the theory related to PD and the associated measurement techniques is now necessary knowledge for power engineers in their professional life. This paper presents a modular course on PD phenomenon in which…

  8. Propagation of Partial Discharge and Noise Pulses in Turbine Generators

    Henriksen, Mogens; Stone, G. C.; Kurtz, M.

    1986-01-01

    Changes with time in the partial discharge (PD) activity originating in a generator stator's insulation system provide information about the electrical integrity of the stator winding. It is desirable to measure PD during normal service to minimize costs. To do this successfully, the influence...... of electrical interference must be reduced. Tests are reported which characterize the nature of discharge and noise pulses when using capacitive couplers mounted on each of the phase leads and an RF current transformer mounted on the neutral lead for signal detection. Significant differences between PD...... and electrical noise have been observed....

  9. Fiber Fabry-Perot sensors for detection of partial discharges in power transformers.

    Yu, Bing; Kim, Dae Woong; Deng, Jiangdong; Xiao, Hai; Wang, Anbo

    2003-06-01

    A diaphragm-based interferometric fiberoptic sensor that uses a low-coherence light source was designed and tested for on-line detection of the acoustic waves generated by partial discharges inside high-voltage power transformers. The sensor uses a fused-silica diaphragm and a single-mode optical fiber encapsulated in a fused-silica glass tube to form an extrinsic Fabry-Perot interferometer, which is interrogated by low-coherence light. Test results indicate that these fiber optic acoustic sensors are capable of faithfully detecting acoustic signals propagating inside transformer oil with high sensitivity and wide bandwidth.

  10. Partial Discharge Tests using the Cigré II method

    Casale, M. Di Lorenzo del; Schifani, R.; Holbøll, Joachim

    2000-01-01

    In this paper, the results of an experimental project on insulating material aging, performed in both Denmark and Italy, are reported. This study was concerned with partial discharge (PD) behavior at temperatures between 30 and 80°C using CIGRE method II. The material tested was a commercial...... polymethylmethacrylate (PMMA) which was chosen not for its good dielectric properties but rather because much of its discharge resistance data at ambient temperature is already well documented. A description is given of the theoretical and experimental methodology followed in this work. Mixed Weibull analysis techniques...... in terms of the PD amplitude and phase distribution characteristics were employed to distinguish the presence of different aging mechanisms. Such a difference was observed at 30 and at 80°C. At 30°C the analysis inferred a single discharge aging process acting until breakdown, while at 80°C the results...

  11. Partial discharge characteristics and mechanism in voids at impulse voltages

    Zhao, X F; Guo, Z F; Wang, Y Y; Li, J H; Li, Y M; Yao, X

    2011-01-01

    Partial discharge (PD) characteristics and mechanism in artificial cavities in an epoxy plate have been investigated for different void dimensions and impulse voltage waveforms. A differential measurement system was developed in order to detect PD current pulses effectively. Experimental results showed that the 50% probability PD inception voltage (PDIV 50 ) increases initially as the cavity diameter decreases at constant depth for double exponential impulses as well as oscillating impulses, but after aging, it becomes independent of the cavity diameter. Moreover, some distinctive characteristics of PD (e.g. main discharge and reverse discharge during the rise and fall phases of the applied voltage) were also investigated. The differences of the PD propagation and the mechanism between double exponential impulses and oscillating impulse were discussed

  12. Design parameter based method of partial discharge detection and location in power transformers

    Kumar Santosh Annadurai

    2009-01-01

    Full Text Available Insulation defect detection in time ensures higher operational reliability of power system assets. Power transformers are the most critical unit of power systems both from economical and operational front. Hence it becomes necessary to have knowledge of the actual insulation condition of transformer to increase dependability of the system. The performance and ageing of the transformer insulation is mainly affected by Partial discharges (PD. Proper diagnosis in terms of amplitude and location of partial discharge in a power transformer enables us to predict well in advance, with much confidence, the defect in insulation system, which avoids large catastrophic failures. In this work a 20kVA, 230/50kV single phase core type transformer is used for evaluation of the transfer function-based partial discharge detection and location using modeling of the winding, using design data. The simulation of capturing on-line PD pulses across the bushing tap capacitor is done for various tap positions. Standard PD source model is used to inject PD pulse signal at 10 tap locations in the winding and corresponding response signatures are captured at the bushing tap end (across 1000pF. The equivalent high frequency model of the winding is derived from the design parameters using analytical calculations and simulations in packages such as MAGNET and ANSOFT. The test conditions are simulated using ORCAD-9 and the results are evaluated for location accuracy using design parameter based PD monitoring method. .

  13. A Rectangular Planar Spiral Antenna for GIS Partial Discharge Detection

    Xiaoxing Zhang

    2014-01-01

    Full Text Available A rectangular planar spiral antenna sensor was designed for detecting the partial discharge in gas insulation substations (GIS. It can expediently receive electromagnetic waves leaked from basin-type insulators and can effectively suppress low frequency electromagnetic interference from the surrounding environment. Certain effective techniques such as rectangular spiral structure, bow-tie loading, and back cavity structure optimization during the antenna design process can miniaturize antenna size and optimize voltage standing wave ratio (VSWR characteristics. Model calculation and experimental data measured in the laboratory show that the antenna possesses a good radiating performance and a multiband property when working in the ultrahigh frequency (UHF band. A comparative study between characteristics of the designed antenna and the existing quasi-TEM horn antenna was made. Based on the GIS defect simulation equipment in the laboratory, partial discharge signals were detected by the designed antenna, the available quasi-TEM horn antenna, and the microstrip patch antenna, and the measurement results were compared.

  14. Partial discharges and breakdown in C3F8

    Koch, M; Franck, C M

    2014-01-01

    Traditional search processes of gases or gas mixtures for replacing SF 6 involve time consuming measurements of partial discharges and breakdown behaviour for several voltage waveforms and different field configurations. Recently a model for prediction of this behaviour for SF 6 was described in literature. The model only requires basic properties of the gas such as the critical field strength and the effective ionization coefficient, which can be obtained by swarm parameter measurements, and thermodynamic properties, which can be calculated. In this paper, we show for the well-known and electronegative gas octafluoropropane (C 3 F 8 ) that it is possible to transfer the model developed for SF 6 to this gas to describe the breakdown behaviour of C 3 F 8 . Thus the model can be beneficial in the screening process of new insulation gases. (paper)

  15. Partial discharges and breakdown in C3F8

    Koch, M.; Franck, C. M.

    2014-10-01

    Traditional search processes of gases or gas mixtures for replacing SF6 involve time consuming measurements of partial discharges and breakdown behaviour for several voltage waveforms and different field configurations. Recently a model for prediction of this behaviour for SF6 was described in literature. The model only requires basic properties of the gas such as the critical field strength and the effective ionization coefficient, which can be obtained by swarm parameter measurements, and thermodynamic properties, which can be calculated. In this paper, we show for the well-known and electronegative gas octafluoropropane (C3F8) that it is possible to transfer the model developed for SF6 to this gas to describe the breakdown behaviour of C3F8. Thus the model can be beneficial in the screening process of new insulation gases.

  16. Analysis of Partial Discharge Activity for Evaluation of the State of High Power Electric Generators Stator Windings

    Dumitrescu Sorin

    2016-08-01

    Full Text Available The paper shows the importance of trending of partial discharge activity in assessing the insulation condition. It is presented the principle of the measurement method and the quantities that characterize partial discharges and also the criteria utilized for the assessement of the insulation condition of the hydrogenerators. Results of the measurements made on several hydrogenerators are presented, like the variation with time of the two main quantities that characterize the partial discharges, maximum magnitude, Qm and the normalized quantity, NQN over a period of about 10 years. Further, a classification of the insulation condition by 3 main and 2 intermediary categories and the definition of these categories are given. The criteria used for the assessment of the insulation condition are presented in the form of a table: quantitative criteria by the ± NQN and ± Qm values and qualitative criteria for the analysis of the 2D and 3D diagrams. At the end of each set of measurements, an analyze of the insulation condition annual evaluation is made, also a verdict is put, and of course, the recommendations made relating to the maintenance and the decisions that have been taken. The paper ends with several considerations on the method of on-line partial discharges and especially, on the conditions for valid trending activity in time.

  17. Partial discharges within two spherical voids in an epoxy resin

    Illias, H A; Mokhlis, H; Tunio, M A; Chen, G; Bakar, A H A

    2013-01-01

    A void in a dielectric insulation material may exist due to imperfection in the insulation manufacturing or long term stressing. Voids have been identified as one of the common sources of partial discharge (PD) activity within an insulation system, such as in cable insulation and power transformers. Therefore, it is important to study PD phenomenon within void cavities in insulation. In this work, a model of PD activity within two spherical voids in a homogeneous dielectric material has been developed using finite element analysis software to study the parameters affecting PD behaviour. The parameters that have been taken into account are the void surface conductivity, electron generation rate and the inception and extinction fields. Measurements of PD activity within two spherical voids in an epoxy resin under ac sinusoidal applied voltage have also been performed. The simulation results have been compared with the measurement data to validate the model and to identify the parameters affecting PD behaviour. Comparison between measurements of PD activity within single and two voids in a dielectric material have also been made to observe the difference of the results under both conditions. (paper)

  18. Towards Optical Partial Discharge Detection with Micro Silicon Photomultipliers

    Ming Ren

    2017-11-01

    Full Text Available Optical detection is reliable in intrinsically characterizing partial discharges (PDs. Because of the great volume and high-level power supply of the optical devices that can satisfy the requirements in photosensitivity, optical PD detection can merely be used in laboratory studies. To promote the practical application of the optical approach in an actual power apparatus, a silicon photomultiplier (SiPM-based PD sensor is introduced in this paper, and its basic properties, which include the sensitivity, pulse resolution, correlation with PD severity, and electromagnetic (EM interference immunity, are experimentally evaluated. The stochastic phase-resolved PD pattern (PRPD for three typical insulation defects are obtained by SiPM PD detector and are compared with those obtained using a high-frequency current transformer (HFCT and a vacuum photomultiplier tube (PMT. Because of its good performances in the above aspects and its additional advantages, such as the small size, low power supply, and low cost, SiPM offers great potential in practical optical PD monitoring.

  19. A Review of Online Partial Discharge Measurement of Large Generators

    Yuanlin Luo

    2017-10-01

    Full Text Available Online partial discharge (PD measurements have long been used as an effective means to assess the condition of the stator windings of large generators. An increase in the use of PD online measurement systems during the last decade is evident. Improvements in the detection capabilities are partly the reason for the increased popularity. Another reason has been the development of digital signal processing techniques. In addition, rapid progress is being made in automated single PD source classification. However, there are still some factors hindering wider application of the system, such as the complex PD mechanism and PD pulse propagation in stator windings, the presence of detrimental noise and disturbances on-site, and multiple PD sources occurring simultaneously. To avoid repetition of past work and to provide an overview for fresh researchers in this area, this paper presents a comprehensive survey of the state-of-the-art knowledge on PD mechanism, PD pulse propagation in stator windings, PD signal detection methods and signal processing techniques. Areas for further research are also presented.

  20. Baseline correction combined partial least squares algorithm and its application in on-line Fourier transform infrared quantitative analysis.

    Peng, Jiangtao; Peng, Silong; Xie, Qiong; Wei, Jiping

    2011-04-01

    In order to eliminate the lower order polynomial interferences, a new quantitative calibration algorithm "Baseline Correction Combined Partial Least Squares (BCC-PLS)", which combines baseline correction and conventional PLS, is proposed. By embedding baseline correction constraints into PLS weights selection, the proposed calibration algorithm overcomes the uncertainty in baseline correction and can meet the requirement of on-line attenuated total reflectance Fourier transform infrared (ATR-FTIR) quantitative analysis. The effectiveness of the algorithm is evaluated by the analysis of glucose and marzipan ATR-FTIR spectra. BCC-PLS algorithm shows improved prediction performance over PLS. The root mean square error of cross-validation (RMSECV) on marzipan spectra for the prediction of the moisture is found to be 0.53%, w/w (range 7-19%). The sugar content is predicted with a RMSECV of 2.04%, w/w (range 33-68%). Copyright © 2011 Elsevier B.V. All rights reserved.

  1. Partial discharge as a stator winding evaluation tool

    Maughan, C.V.

    2005-01-01

    This paper has been prepared to illustrate the value of partial discharge (PD) testing in assessing the condition of stator windings on operating generators and motors. The database of one particular PD system vendor was chosen for this study because of the magnitude of data accumulated by this company over the last 15 years. It was felt that sufficient data had been accumulated to allow useful statistical analysis of the capabilities of PD testing. The PD detection technology used by Iris has been installed on about 6000 generators and motors, and has inspection information from about 3600 machines. On these 3600 generators and motors, PD has successfully identified 209 potential problems that were verified by inspection to be present. In most cases, moderate corrective maintenance permitted return of the equipment to service without major repairs. An estimate of the actual number of avoided failures was not possible from the available reports. But it is clear that many potentially serious stator winding failures were avoided as a result of removal of these machines from service because of high PD readings. No attempt has been made in the paper to provide technical background or details of the PD test/analysis processes. There are numerous technical papers and industry guides; the interested reader is referred to IEEE 1434, EPRI Reports, and other documents in the Bibliography. While this paper is based somewhat narrowly on data from only one company, there are several other companies involved in PD testing and evaluation. As described below in this paper, these companies have also been successful in identifying stator winding problems through the use of PD equipment. Clearly, PD testing is a useful tool in monitoring and assessing the condition of stator windings, as well as other associated electrical equipment in the power plant. Because of the power of PD testing, it is expected that the use of PD monitoring will continue to expand at a significant rate in

  2. On the electrodynamics of partial discharges in voids in solid dielectrics

    Pedersen, Aage

    1989-01-01

    It is suggested that a correct interpretation of partial-discharge transients can be obtained only through the concept of induced charge. The application of this concept enables a partial-discharge theory to be developed by means of which the influence of relevant void parameters can be assessed ...

  3. Partial discharge patterns related to surface deterioration in voids in epoxy

    Holbøll, Joachim; Henriksen, Mogens

    1990-01-01

    Results are presented from an investigation of the relationship between changes in partial discharge patterns and the surface deterioration process taking place in small naturally formed spherical voids in epoxy plastic. The voids were exposed to a moderate electric stress above inception level......, where partial discharges were present for more than 1500 h. Two types of electrical tree growth were found, the bush like tree and a single channel-like tree, which led to very different partial discharge patterns. It is concluded that the formation of crystals on a void surface leads to an immediate...... and easy-to-detect increase in the partial discharge activity with subsequent severe surface deterioration (deep pit formations) in the vicinity of the crystal. However, the partial discharge signal from a specimen with a black channel-like tree structure did not give any indication of channel growth...

  4. Comments on evaluation of energy of partial discharges in ionization chambers

    Lechowski, Z.

    1980-01-01

    A method of evaluation of energy of partial discharges in ionization chambers which are intended for investigation on electric strength of insulating materials is presented. It is demonstrated that an ionization chamber must be considered as a set of discharge sources and that for energy evaluation an amplitude analysis of apparent charge of discharges is useful. (author)

  5. Partial oxidation of methane in a temperature-controlled dielectric barrier discharge reactor

    Zhang, Xuming; Cha, Min

    2015-01-01

    We studied the relative importance of the reduced field intensity and the background reaction temperature in the partial oxidation of methane in a temperature-controlled dielectric barrier discharge reactor. We obtained important mechanistic insight

  6. The electric strength of high-voltage transformers insulation at effect of partial dischargers

    Khoshravan, E.; Zeraatparvar, A.; Gashimov, A.M.; Mehdizadeh, R.N.

    2001-01-01

    Full text : In paper the change of electric strength of high-voltage transformers insulation at the effect of partial discharges with space charge accumulation was investigated. It is revealed that the effect of partial discharges of insulation materials results the reduction of their pulsing electric strength which can restore the own initial value at releasing of saved charge the volume of a material under condition of absence the ineversible structural changes in it. Researches of high-voltage transformers insulation's non-failure operation conditions show, that at increasing of insulation work time in a strong electrical field the reduction of average breakdown voltages with simultaneous increasing of spread in discharge voltage values takes place. It authentically testifies to reduction of short-time discharge voltage of insulation materials during their electrical aging. As the basic reason of insulation electrical aging the partial discharges occurring in gas cavities inside insulation were considered. It is known that the space charges will be formed in insulation elements of high-voltage devices which effects in dielectrical property of these elements including the electric strength and the space charge formation can occur also at partial discharges in an alternating voltage while the service of high-voltage transformers. In the given work the experiments in revealing separate influence partial discharges in pulsing electric strength of insulation materials at presence and at absence inside them the space charge were spent

  7. Partial Discharge Monitoring in Power Transformers Using Low-Cost Piezoelectric Sensors.

    Castro, Bruno; Clerice, Guilherme; Ramos, Caio; Andreoli, André; Baptista, Fabricio; Campos, Fernando; Ulson, José

    2016-08-10

    Power transformers are crucial in an electric power system. Failures in transformers can affect the quality and cause interruptions in the power supply. Partial discharges are a phenomenon that can cause failures in the transformers if not properly monitored. Typically, the monitoring requires high-cost corrective maintenance or even interruptions of the power system. Therefore, the development of online non-invasive monitoring systems to detect partial discharges in power transformers has great relevance since it can reduce significant maintenance costs. Although commercial acoustic emission sensors have been used to monitor partial discharges in power transformers, they still represent a significant cost. In order to overcome this drawback, this paper presents a study of the feasibility of low-cost piezoelectric sensors to identify partial discharges in mineral insulating oil of power transformers. The analysis of the feasibility of the proposed low-cost sensor is performed by its comparison with a commercial acoustic emission sensor commonly used to detect partial discharges. The comparison between the responses in the time and frequency domain of both sensors was carried out and the experimental results indicate that the proposed piezoelectric sensors have great potential in the detection of acoustic waves generated by partial discharges in insulation oil, contributing for the popularization of this noninvasive technique.

  8. Partial Discharge Monitoring in Power Transformers Using Low-Cost Piezoelectric Sensors

    Bruno Castro

    2016-08-01

    Full Text Available Power transformers are crucial in an electric power system. Failures in transformers can affect the quality and cause interruptions in the power supply. Partial discharges are a phenomenon that can cause failures in the transformers if not properly monitored. Typically, the monitoring requires high-cost corrective maintenance or even interruptions of the power system. Therefore, the development of online non-invasive monitoring systems to detect partial discharges in power transformers has great relevance since it can reduce significant maintenance costs. Although commercial acoustic emission sensors have been used to monitor partial discharges in power transformers, they still represent a significant cost. In order to overcome this drawback, this paper presents a study of the feasibility of low-cost piezoelectric sensors to identify partial discharges in mineral insulating oil of power transformers. The analysis of the feasibility of the proposed low-cost sensor is performed by its comparison with a commercial acoustic emission sensor commonly used to detect partial discharges. The comparison between the responses in the time and frequency domain of both sensors was carried out and the experimental results indicate that the proposed piezoelectric sensors have great potential in the detection of acoustic waves generated by partial discharges in insulation oil, contributing for the popularization of this noninvasive technique.

  9. Critical analysis of partial discharge dynamics in air filled spherical voids

    Callender, G.; Golosnoy, I. O.; Rapisarda, P.; Lewin, P. L.

    2018-03-01

    In this paper partial discharge (PD) is investigated inside a spherical air filled void at atmospheric pressure using a drift diffusion model. Discharge dynamics consisted of an electron avalanche transitioning into positive streamer, in agreement with earlier work on dielectric barrier discharges. Different model configurations were utilised to test many of the concepts employed in semi-analytical PD activity models, which use simplistic descriptions of the discharge dynamics. The results showed that many of these concepts may be erroneous, with significant discrepancies between the canonical reasoning and the simulation results. For example, the residual electric field, the electric field after a discharge, is significantly lower than the estimates used by classical PD activity models in the literature.

  10. Analysis of Insulating Material of XLPE Cables considering Innovative Patterns of Partial Discharges

    Fernando Figueroa Godoy

    2017-01-01

    Full Text Available This paper aims to analyze the quality of insulation in high voltage underground cables XLPE using a prototype which classifies the following usual types of patterns of partial discharge (PD: (1 internal PD, (2 superficial PD, (3 corona discharge in air, and (4 corona discharge in oil, in addition to considering two new PD patterns: (1 false contact and (2 floating ground. The tests and measurements to obtain the patterns and study cases of partial discharges were performed at the Testing Laboratory Equipment and Materials (LEPEM of the Federal Electricity Commission of Mexico (CFE using a measuring equipment LDIC and norm IEC60270. To classify the six patterns of partial discharges mentioned above a Probabilistic Neural Network Bayesian Modified (PNNBM method having the feature of using a large amount of data will be used and it is not saturated. In addition, PNN converges, always finding a solution in a short period of time with low computational cost. The insulation of two high voltage cables with different characteristics was analyzed. The test results allow us to conclude which wire has better insulation.

  11. Development of a method of partial discharge detection in extra-high voltage cross-linked polyethylene insulated cable lines

    Katsuta, G.; Toya, A.; Muraoka, K.; Endoh, T.; Sekii, Y.; Ikeda, C.

    1992-01-01

    This paper reports that deterioration in the insulation performance of extra-high voltage XLPE cables is believed to be attributable to the deterioration caused by partial discharges. In the authors study, after using an XLPE cable to investigate the behavior of partial discharges under various adverse conditions, we succeeded in developing a highly sensitive new method of measuring partial discharge in XLPE cable lines. Partial discharges in a 275 kV XLPE cable live line has been measured using this newly developed method. As a result, a detection sensitivity of 1 pC has been achieved

  12. Influence of bulk dielectric polarization upon partial discharge transients effect of heterogeneous dielectric geometry

    McAllister, Iain Wilson; Crichton, George C.

    2000-01-01

    A physically valid theory of partial discharge (PD) transients is based upon the concept of the charge induced upon the detecting electrode by the PD. This induced charge consists of two components. One is associated with the actual space charge in the void, while the other is related to changes...

  13. Influence of bulk dielectric polarization upon partial discharge transients: Effect of void geometry and orientation

    McAllister, Iain Wilson; Crichton, G.C.

    2005-01-01

    The induced charge arising from a partial discharge consists of 2 components. One is associated with the actual space charge in the void. The other is related to changes in the polarization of the bulk dielectric. These changes are a direct consequence of the field produced by the space charge...

  14. Technical advancements in the integration of online partial discharge monitoring in distribution cable networks

    Wagenaars, P.; Wouters, P.A.A.F.; Wielen, van der P.C.J.M.; Steennis, F.

    2009-01-01

    Online partial discharge (PD) detection and location systems for medium-voltage (MV) cables have been developed over the past years and are currently introduced by utilities on an increasingly large scale. This paper addresses a few of the new challenges related to the integration of these systems

  15. Virtual-Instrument-Based Online Monitoring System for Hands-on Laboratory Experiment of Partial Discharges

    Karmakar, Subrata

    2017-01-01

    Online monitoring of high-voltage (HV) equipment is a vital tool for early detection of insulation failure. Most insulation failures are caused by partial discharges (PDs) inside the HV equipment. Because of the very high cost of establishing HV equipment facility and the limitations of electromagnetic interference-screened laboratories, only a…

  16. Online calibration of high-frequency partial discharge signals in three-phase belted power cables

    Wouters, P.A.A.F.

    2005-01-01

    Partial discharge (PD) magnitudes from classical detection techniques are expressed in terms of apparent charges. Signals from HF/VHF/UHF techniques on substation components are often hard to express in this quantity because of complex signal excitation and propagation channels. A method to

  17. Partial Discharge Measurements in HV Rotating Machines in Dependence on Pressure of Coolant

    I. Kršňák

    2002-01-01

    Full Text Available The influence of the pressure of the coolant used in high voltage rotating machines on partial discharges occurring in stator insulation is discussed in this paper. The first part deals with a theoretical analysis of the topic. The second part deals with the results obtained on a real generator in industrial conditions. Finally, theoretical assumptions and obtained results are compared.

  18. Shoulder replacement - discharge

    Total shoulder arthroplasty - discharge; Endoprosthetic shoulder replacement - discharge; Partial shoulder replacement - discharge; Partial shoulder arthroplasty - discharge; Replacement - shoulder - discharge; Arthroplasty - shoulder - discharge

  19. Acoustic position finding of partial discharges in transformers. Combination of partial discharge measurement technology with 3D visualization; Akustische Ortung von Teilentladungen in Transformatoren. TE-Messtechnik und 3-D-Visualisierung kombiniert

    Kraetge, Alexander; Hoek, Stefan [Omicron Electronics GmbH, Klaus (Austria)

    2013-11-01

    A new measuring system facilitates the detection of partial discharges in transformers by means of the fully synchronous combination of measurement technology for electrical partial discharges with intuitive 3D visualization of the test object. The contribution under consideration describes the application of this system with examples from the measurement practice.

  20. Partial discharge testing: a progress report. Statistical evaluation of PD data

    Warren, V.; Allan, J.

    2005-01-01

    It has long been known that comparing the partial discharge results obtained from a single machine is a valuable tool enabling companies to observe the gradual deterioration of a machine stator winding and thus plan appropriate maintenance for the machine. In 1998, at the annual Iris Rotating Machines Conference (IRMC), a paper was presented that compared thousands of PD test results to establish the criteria for comparing results from different machines and the expected PD levels. At subsequent annual Iris conferences, using similar analytical procedures, papers were presented that supported the previous criteria and: in 1999, established sensor location as an additional criterion; in 2000, evaluated the effect of insulation type and age on PD activity; in 2001, evaluated the effect of manufacturer on PD activity; in 2002, evaluated the effect of operating pressure for hydrogen-cooled machines; in 2003, evaluated the effect of insulation type and setting Trac alarms; in 2004, re-evaluated the effect of manufacturer on PD activity. Before going further in database analysis procedures, it would be prudent to statistically evaluate the anecdotal evidence observed to date. The goal was to determine which variables of machine conditions greatly influenced the PD results and which didn't. Therefore, this year's paper looks at the impact of operating voltage, machine type and winding type on the test results for air-cooled machines. Because of resource constraints, only data collected through 2003 was used; however, as before, it is still standardized for frequency bandwidth and pruned to include only full-load-hot (FLH) results collected for one sensor on operating machines. All questionable data, or data from off-line testing or unusual machine conditions was excluded, leaving 6824 results. Calibration of on-line PD test results is impractical; therefore, only results obtained using the same method of data collection and noise separation techniques are compared. For

  1. Inductive Sensor Performance in Partial Discharges and Noise Separation by Means of Spectral Power Ratios

    Jorge Alfredo Ardila-Rey

    2014-02-01

    Full Text Available Partial discharge (PD detection is a standardized technique to qualify electrical insulation in machines and power cables. Several techniques that analyze the waveform of the pulses have been proposed to discriminate noise from PD activity. Among them, spectral power ratio representation shows great flexibility in the separation of the sources of PD. Mapping spectral power ratios in two-dimensional plots leads to clusters of points which group pulses with similar characteristics. The position in the map depends on the nature of the partial discharge, the setup and the frequency response of the sensors. If these clusters are clearly separated, the subsequent task of identifying the source of the discharge is straightforward so the distance between clusters can be a figure of merit to suggest the best option for PD recognition. In this paper, two inductive sensors with different frequency responses to pulsed signals, a high frequency current transformer and an inductive loop sensor, are analyzed to test their performance in detecting and separating the sources of partial discharges.

  2. Disturbance Elimination for Partial Discharge Detection in the Spacer of Gas-Insulated Switchgears

    Guoming Wang

    2017-11-01

    Full Text Available With the increasing demand for precise condition monitoring and diagnosis of gas-insulated switchgears (GISs, it has become a challenge to improve the detection sensitivity of partial discharge (PD induced in the GIS spacer. This paper deals with the elimination of the capacitive component from the phase-resolved partial discharge (PRPD signal generated in GIS spacers based on discrete wavelet transform (WT. Three types of typical insulation defects were simulated using PD cells. The single PD pulses were detected and were further used to determine the optimal mother wavelet. As a result, the bior6.8 was selected to decompose the PD signal into 8 levels and the signal energy at each level was calculated. The decomposed components related with capacitive disturbance were discarded, whereas those associated with PD were de-noised by a threshold and a thresholding function. Finally, the PRPD signals were reconstructed using the de-noised components.

  3. Partial discharge measurements on 110kV current transformers. Setting the control value. Case study

    Dan, C.; Morar, R.

    2017-05-01

    The case study presents a series of partial discharge measurements, reflecting the state of insulation of 110kV CURRENT TRANSFORMERS located in Sibiu county substations. Measurements were performed based on electrical method, using MPD600: an acquisition and analysis toolkit for detecting, recording, and analyzing partial discharges. MPD600 consists of one acquisition unit, an optical interface and a computer with dedicated software. The system allows measurements of partial discharge on site, even in presence of strong electromagnetic interferences because it provides synchronous acquisition from all measurement points. Therefore, measurements, with the ability to be calibrated, do render: - a value subject to interpretation according to IEC 61869-1:2007 + IEC 61869-2:2012 + IEC 61869-3:2011 + IEC 61869-5:2011 and IEC 60270: 2000; - the possibility to determine the quantitative limit of PD (a certain control value) to which the equipment can be operated safely and repaired with minimal costs (relative to the high costs implied by eliminating the consequences of a failure) identified empirically (process in which the instrument transformer subjected to the tests was completely destroyed).

  4. Ageing of insulation and diagnosis of electrical equipment through detection of partial discharge

    Lopez Vergara, T.; Velasco Bernal, C.

    1994-01-01

    Ageing in electrical equipment affects mainly its insulation system. Such ageing in the insulation system is determined by its organic nature, basically constituted by three families of materials: cellulose, resin and hydrocarbon. All of these are affected by high temperatures, which tend to produce a break in the molecular chains (if the temperatures are not too high) or carbonization and gasification of the material (if they are). The radiation absorbed by the insulating materials also destroys molecular chains, causing degradation of the material. The break of the molecular chains, especially in the polymer-based materials, fragments the material, mainly in areas subjected to mechanical forces and stresses. From the electrical point of view, fissures occurring the insulating material lead to a much lower dielectric strength in certain parts of the materials, which could produce partial discharge conditions. Therefore, the growth of partial discharges in electrical equipment items is frequently the consequences of ageing, and be used to evaluate their residual life. Empresarios Agrupados has developed a system to detect partial discharges which can be used while equipment is still in operation. The measurements taken with this system are sufficiently accurate and repetitive to be used in evaluating the condition of medium-voltage electrical equipment insulation. (Author)

  5. Partial oxidation of methane in a temperature-controlled dielectric barrier discharge reactor

    Zhang, Xuming

    2015-01-01

    We studied the relative importance of the reduced field intensity and the background reaction temperature in the partial oxidation of methane in a temperature-controlled dielectric barrier discharge reactor. We obtained important mechanistic insight from studying high-temperature and low-pressure conditions with similar reduced field intensities. In the tested range of background temperatures (297 < T < 773 K), we found that the conversion of methane and oxygen depended on both the electron-induced chemistry and the thermo-chemistry, whereas the chemical pathways to the products were overall controlled by the thermo-chemistry at a given temperature. We also found that the thermo-chemistry enhanced the plasma-assisted partial oxidation process. Our findings expand our understanding of the plasma-assisted partial oxidation process and may be helpful in the design of cost-effective plasma reformers. © 2014 The Combustion Institute.

  6. Statistical Analysis of Partial Discharge Characteristics in Transformer Oil at the “Point-Plane” Electrode at Alternating Voltage

    Korobeynikov S.M.

    2017-08-01

    Full Text Available In this paper, we consider the problems related to measuring and analyzing the characteristics of partial discharges which are the main instrument for oil-filled high-voltage electrical equipment diagnosing. The experiments on recording of partial discharges in transformer oil have been carried out in the “point-plane” electrode system at alternating current. The instantaneous voltage and the apparent charge have been measured depending on the root-mean-square voltage and the phase angle of partial discharges. This paper aimes at carrying out a statistical analysis of the obtained experimental results, in particular, the construction of a parametric probabilistic model of the dependence of the partial discharge inception voltage distribution on the value of the root-mean-square voltage. It differs from usual discharges which occur in liquid dielectric materials in case of sharp inhomogeneous electrode system. It has been suggested that discharges of a different type are the discharges in gas bubbles that occur when partial discharges in a liquid emerge. This assumption is confirmed by the fact that the number of such discharges increases with increasing the root-mean-square voltage value. It is the main novelty of this paper. This corresponds to the nature of the occurrence of such discharges. After rejecting the observations corresponding to discharges in gas bubbles, a parametric probabilistic model has been constructed. The model obtained makes it possible to determine the probability of partial discharge occurrence in a liquid at a given value of the instantaneous voltage depending on the root-mean-square voltage.

  7. Determination of Hg{sup 2+} by on-line separation and pre-concentration with atmospheric-pressure solution-cathode glow discharge atomic emission spectrometry

    Li, Qing [Shanghai Institute of Ceramics, Chinese Academy of Science, Shanghai 200050 (China); Zhang, Zhen [Shanghai Institute of Ceramics, Chinese Academy of Science, Shanghai 200050 (China); School of Materials Science and Engineering, Shanghai University, Shanghai 200072 (China); Wang, Zheng, E-mail: wangzheng@mail.sic.ac.cn [Shanghai Institute of Ceramics, Chinese Academy of Science, Shanghai 200050 (China)

    2014-10-03

    Highlights: • A modified SBA-15 mesoporous silica (SH-SBA-15) was synthesized as a sorbent. • On-line SPE combined with SCGD-AES based on FIA was used to detect Hg{sup 2+} firstly. • A simple, low-cost Hg{sup 2+} analysis in a complex matrix was established. • The sensitive detection of Hg{sup 2+} was achieved with a detection limit of 0.75 μg L{sup −1}. - Abstract: A simple and sensitive method to determine Hg{sup 2+} was developed by combining solution-cathode glow discharge atomic emission spectrometry (SCGD-AES) with flow injection (FI) based on on-line solid-phase extraction (SPE). We synthesized L-cysteine-modified mesoporous silica and packed it in an SPE microcolumn, which was experimentally determined to possess a good mercury adsorption capacity. An enrichment factor of 42 was achieved under optimized Hg{sup 2+} elution conditions, namely, an FI flow rate of 2.0 mL min{sup −1} and an eluent comprised of 10% thiourea in 0.2 mol L{sup −1} HNO{sub 3}. The detection limit of FI–SCGD-AES was determined to be 0.75 μg L{sup −1}, and the precision of the 11 replicate Hg{sup 2+} measurements was 0.86% at a concentration of 100 μg L{sup −1}. The proposed method was validated by determining Hg{sup 2+} in certified reference materials such as human hair (GBW09101b) and stream sediment (GBW07310)

  8. Method for measuring the stochastic properties of corona and partial-discharge pulses

    Van Brunt, R.J.; Kulkarni, S.V.

    1989-01-01

    A new method is described for measuring the stochastic behavior of corona and partial-discharge pulses which utilizes a pulse selection and sorting circuit in conjunction with a computer-controlled multichannel analyzer to directly measure various conditional and unconditional pulse-height and pulse-time-separation distributions. From these measured distributions it is possible to determine the degree of correlation between successive discharge pulses. Examples are given of results obtained from measurements on negative, point-to-plane (Trichel-type) corona pulses in a N 2 /O 2 gas mixture which clearly demonstrate that the phenomenon is inherently stochastic in the sense that development of a discharge pulse is significantly affected by the amplitude of and time separation from the preceding pulse. It is found, for example, that corona discharge pulse amplitude and time separation from an earlier pulse are not independent random variables. Discussions are given about the limitations of the method, sources of error, and data analysis procedures required to determine self-consistency of the various measured distributions

  9. Partial Discharge Spectral Characterization in HF, VHF and UHF Bands Using Particle Swarm Optimization.

    Robles, Guillermo; Fresno, José Manuel; Martínez-Tarifa, Juan Manuel; Ardila-Rey, Jorge Alfredo; Parrado-Hernández, Emilio

    2018-03-01

    The measurement of partial discharge (PD) signals in the radio frequency (RF) range has gained popularity among utilities and specialized monitoring companies in recent years. Unfortunately, in most of the occasions the data are hidden by noise and coupled interferences that hinder their interpretation and renders them useless especially in acquisition systems in the ultra high frequency (UHF) band where the signals of interest are weak. This paper is focused on a method that uses a selective spectral signal characterization to feature each signal, type of partial discharge or interferences/noise, with the power contained in the most representative frequency bands. The technique can be considered as a dimensionality reduction problem where all the energy information contained in the frequency components is condensed in a reduced number of UHF or high frequency (HF) and very high frequency (VHF) bands. In general, dimensionality reduction methods make the interpretation of results a difficult task because the inherent physical nature of the signal is lost in the process. The proposed selective spectral characterization is a preprocessing tool that facilitates further main processing. The starting point is a clustering of signals that could form the core of a PD monitoring system. Therefore, the dimensionality reduction technique should discover the best frequency bands to enhance the affinity between signals in the same cluster and the differences between signals in different clusters. This is done maximizing the minimum Mahalanobis distance between clusters using particle swarm optimization (PSO). The tool is tested with three sets of experimental signals to demonstrate its capabilities in separating noise and PDs with low signal-to-noise ratio and separating different types of partial discharges measured in the UHF and HF/VHF bands.

  10. Measurement of partial discharge inception characteristics in sub-cooled liquid nitrogen

    Koo, J.Y.; Lee, S.H.; Shin, W.J.; Khan, Umer A.; Oh, S.H.; Seong, J.K.; Lee, B.W.

    2011-01-01

    We measured partial discharge and partial discharge initiation voltage of subcooled liquid nitrogen. Various kinds of test samples have been prepared. Sub-cooled temperature in liquid nitrogen were changed. The number of PD pluses were decreased when 68 K liquid nitrogen was used. Sub-cooled liquid nitrogen has positive effects to suppress PD activities. Partial discharge (PD) measurement is one of the effective diagnostic techniques to predict abnormal high voltage dielectric insulation conditions of the electric equipments. PD diagnostic techniques were also could be utilized to evaluate the conditions of cryogenic dielectric insulation media of high temperature superconducting electric equipment in liquid nitrogen. Generally, liquid nitrogen at 77 K is used as cryogenic and dielectric media for high temperature superconducting devices for high voltage electric power systems. But due to generation of bubbles during quench conditions which cause harmful effect on the properties of liquid nitrogen insulation, sub-cooled nitrogen under 77 K was also employed to suppress bubble formation. In this work, investigation of PD characteristics of sub-cooled liquid nitrogen was conducted in order to clarify the relation between PD inception and the temperature of liquid nitrogen. It was observed that measured PDIV (PD inception voltage) shows little differences according to the sub-cooled temperature of liquid nitrogen, but the magnitude and total numbers of PD has been slightly decreased according the decrease of cooled temperature of liquid nitrogen. From experimental results, it was deduced that the sub-cooled liquid nitrogen from 68 K to 77 K, could be applicable without any considerations of the variation of PDIV.

  11. Optical fiber sensor of partial discharges in High Voltage DC experiments

    Búa-Núñez, I.; Azcárraga-Ramos, C. G.; Posada-Román, J. E.; Garcia-Souto, J. A.

    2014-05-01

    A setup simulating High Voltage DC (HVDC) transformers barriers was developed to demonstrate the effectiveness of an optical fiber (OF) sensor in detecting partial discharges (PD) under these peculiar conditions. Different PD detection techniques were compared: electrical methods, and acoustic methods. Standard piezoelectric sensors (R15i-AST) and the above mentioned OF sensors were used for acoustic detection. The OF sensor was able to detect PD acoustically with a sensitivity better than the other detection methods. The multichannel instrumentation system was tested in real HVDC conditions with the aim of analyzing the behavior of the insulation (mineral oil/pressboard).

  12. Determination of Hg(2+) by on-line separation and pre-concentration with atmospheric-pressure solution-cathode glow discharge atomic emission spectrometry.

    Li, Qing; Zhang, Zhen; Wang, Zheng

    2014-10-03

    A simple and sensitive method to determine Hg(2+) was developed by combining solution-cathode glow discharge atomic emission spectrometry (SCGD-AES) with flow injection (FI) based on on-line solid-phase extraction (SPE). We synthesized l-cysteine-modified mesoporous silica and packed it in an SPE microcolumn, which was experimentally determined to possess a good mercury adsorption capacity. An enrichment factor of 42 was achieved under optimized Hg(2+) elution conditions, namely, an FI flow rate of 2.0 mL min(-1) and an eluent comprised of 10% thiourea in 0.2 mol L(-1) HNO3. The detection limit of FI-SCGD-AES was determined to be 0.75 μg L(-1), and the precision of the 11 replicate Hg(2+) measurements was 0.86% at a concentration of 100 μg L(-1). The proposed method was validated by determining Hg(2+) in certified reference materials such as human hair (GBW09101b) and stream sediment (GBW07310). Copyright © 2014. Published by Elsevier B.V.

  13. Classification of Partial Discharge Measured under Different Levels of Noise Contamination.

    Wong Jee Keen Raymond

    Full Text Available Cable joint insulation breakdown may cause a huge loss to power companies. Therefore, it is vital to diagnose the insulation quality to detect early signs of insulation failure. It is well known that there is a correlation between Partial discharge (PD and the insulation quality. Although many works have been done on PD pattern recognition, it is usually performed in a noise free environment. Also, works on PD pattern recognition in actual cable joint are less likely to be found in literature. Therefore, in this work, classifications of actual cable joint defect types from partial discharge data contaminated by noise were performed. Five cross-linked polyethylene (XLPE cable joints with artificially created defects were prepared based on the defects commonly encountered on site. Three different types of input feature were extracted from the PD pattern under artificially created noisy environment. These include statistical features, fractal features and principal component analysis (PCA features. These input features were used to train the classifiers to classify each PD defect types. Classifications were performed using three different artificial intelligence classifiers, which include Artificial Neural Networks (ANN, Adaptive Neuro-Fuzzy Inference System (ANFIS and Support Vector Machine (SVM. It was found that the classification accuracy decreases with higher noise level but PCA features used in SVM and ANN showed the strongest tolerance against noise contamination.

  14. Influence of Nanosilica Filler Content in LDPE Composites on Partial Discharge Characteristics

    Z. Abdul-Malek; A.M. Azzin; Y.Z. Ariel; Aulia; K.Y. Lau; M. Jaafar

    2011-01-01

    Partial discharges (PDs) due to artificial void in samples of LDPE nanocomposite sheet have been investiga- ted in this work. PDs may cause the degradation of insulating materials and may affect the lifetime of high-voltage ap- paratus. An experimental work using sphere ball-plane electrode system (CIGRE Method II) and a 1.0 mm LDPE composite sheet was carried out. Different weight percentages of nanosilica (0%, 2%, 4%, 6% and 8%) were used. PD experimental results, such as PD magnitude and PD number (both PD pulse polarities), as functions of the ap- plied stress duration at a specified applied voltage were compared. The surface morphology of specimens was also presented and this conforms to the PD findings. The experimental results show that the PD characteristics of the LDPE generally improve with the introduction of nanosilica, the composite with the highest content of filler, namely the 8% (wt) nanosilica sample has the least partial discharge activities.

  15. Partial Discharge Monitoring on Metal-Enclosed Switchgear with Distributed Non-Contact Sensors

    Chongxing Zhang

    2018-02-01

    Full Text Available Metal-enclosed switchgear, which are widely used in the distribution of electrical energy, play an important role in power distribution networks. Their safe operation is directly related to the reliability of power system as well as the power quality on the consumer side. Partial discharge detection is an effective way to identify potential faults and can be utilized for insulation diagnosis of metal-enclosed switchgear. The transient earth voltage method, an effective non-intrusive method, has substantial engineering application value for estimating the insulation condition of switchgear. However, the practical application effectiveness of TEV detection is not satisfactory because of the lack of a TEV detection application method, i.e., a method with sufficient technical cognition and analysis. This paper proposes an innovative online PD detection system and a corresponding application strategy based on an intelligent feedback distributed TEV wireless sensor network, consisting of sensing, communication, and diagnosis layers. In the proposed system, the TEV signal or status data are wirelessly transmitted to the terminal following low-energy signal preprocessing and acquisition by TEV sensors. Then, a central server analyzes the correlation of the uploaded data and gives a fault warning level according to the quantity, trend, parallel analysis, and phase resolved partial discharge pattern recognition. In this way, a TEV detection system and strategy with distributed acquisition, unitized fault warning, and centralized diagnosis is realized. The proposed system has positive significance for reducing the fault rate of medium voltage switchgear and improving its operation and maintenance level.

  16. Partial Discharge Monitoring on Metal-Enclosed Switchgear with Distributed Non-Contact Sensors.

    Zhang, Chongxing; Dong, Ming; Ren, Ming; Huang, Wenguang; Zhou, Jierui; Gao, Xuze; Albarracín, Ricardo

    2018-02-11

    Metal-enclosed switchgear, which are widely used in the distribution of electrical energy, play an important role in power distribution networks. Their safe operation is directly related to the reliability of power system as well as the power quality on the consumer side. Partial discharge detection is an effective way to identify potential faults and can be utilized for insulation diagnosis of metal-enclosed switchgear. The transient earth voltage method, an effective non-intrusive method, has substantial engineering application value for estimating the insulation condition of switchgear. However, the practical application effectiveness of TEV detection is not satisfactory because of the lack of a TEV detection application method, i.e., a method with sufficient technical cognition and analysis. This paper proposes an innovative online PD detection system and a corresponding application strategy based on an intelligent feedback distributed TEV wireless sensor network, consisting of sensing, communication, and diagnosis layers. In the proposed system, the TEV signal or status data are wirelessly transmitted to the terminal following low-energy signal preprocessing and acquisition by TEV sensors. Then, a central server analyzes the correlation of the uploaded data and gives a fault warning level according to the quantity, trend, parallel analysis, and phase resolved partial discharge pattern recognition. In this way, a TEV detection system and strategy with distributed acquisition, unitized fault warning, and centralized diagnosis is realized. The proposed system has positive significance for reducing the fault rate of medium voltage switchgear and improving its operation and maintenance level.

  17. Partial discharge early-warning through ultraviolet spectroscopic detection of SO2

    Zhao, Yu; Wang, Xianpei; Dai, Dangdang; Dong, Zhengcheng; Huang, Yunguang

    2014-01-01

    Surveillance of SF 6  decomposition products is significant for detection of partial discharge (PD) in gas insulation switchgear (GIS). As a basis in on-site detection and diagnosis, PD early-warning aims to quickly find the abnormalities using a simple and cheap device. In this paper, SO 2  is chosen as a feature product and detected through ultraviolet spectroscopy. The derivative method is employed for baseline correction and spectral enhancement. The standard gases of the main decomposition products are qualitatively and quantitatively detected. Then decomposition experiments with different defects are designed to further verify the feasibility. As a stable decomposition product under PD, SO 2  is proved to be applicable for PD early-warning in the field. By selecting the appropriate wavelength range, namely 290–310 nm, ultraviolet derivative spectroscopy is sensitive enough to the trace SO 2  in the decomposed gas and the interference of other products can be avoided. Fast Fourier transform could be used for feature extraction in qualitative detection. Concentrations of SO 2  and other by-products increase with increasing discharge time and could be affected by the discharge energy and PD type. Ultraviolet detection based on SO 2  is effective for PD early-warning but the threshold should still be carefully selected in practice. (paper)

  18. Improving detection sensitivity for partial discharge monitoring of high voltage equipment

    Hao, L.; Lewin, P. L.; Swingler, S. G.

    2008-05-01

    Partial discharge (PD) measurements are an important technique for assessing the health of power apparatus. Previous published research by the authors has shown that an electro-optic system can be used for PD measurement of oil-filled power transformers. A PD signal generated within an oil-filled power transformer may reach a winding and then travel along the winding to the bushing core bar. The bushing, acting like a capacitor, can transfer the high frequency components of the partial discharge signal to its earthed tap point. Therefore, an effective PD current measurement can be implemented at the bushing tap by using a radio frequency current transducer around the bushing-tap earth connection. In addition, the use of an optical transmission technique not only improves the electrical noise immunity and provides the possibility of remote measurement but also realizes electrical isolation and enhances safety for operators. However, the bushing core bar can act as an aerial and in addition noise induced by the electro-optic modulation system may influence overall measurement sensitivity. This paper reports on a machine learning technique, namely the use of a support vector machine (SVM), to improve the detection sensitivity of the system. Comparison between the signal extraction performances of a passive hardware filter and the SVM technique has been assessed. The results obtained from the laboratory-based experiment have been analysed and indicate that the SVM approach provides better performance than the passive hardware filter and it can reliably detect discharge signals with apparent charge greater than 30 pC.

  19. Improving detection sensitivity for partial discharge monitoring of high voltage equipment

    Hao, L; Lewin, P L; Swingler, S G

    2008-01-01

    Partial discharge (PD) measurements are an important technique for assessing the health of power apparatus. Previous published research by the authors has shown that an electro-optic system can be used for PD measurement of oil-filled power transformers. A PD signal generated within an oil-filled power transformer may reach a winding and then travel along the winding to the bushing core bar. The bushing, acting like a capacitor, can transfer the high frequency components of the partial discharge signal to its earthed tap point. Therefore, an effective PD current measurement can be implemented at the bushing tap by using a radio frequency current transducer around the bushing-tap earth connection. In addition, the use of an optical transmission technique not only improves the electrical noise immunity and provides the possibility of remote measurement but also realizes electrical isolation and enhances safety for operators. However, the bushing core bar can act as an aerial and in addition noise induced by the electro-optic modulation system may influence overall measurement sensitivity. This paper reports on a machine learning technique, namely the use of a support vector machine (SVM), to improve the detection sensitivity of the system. Comparison between the signal extraction performances of a passive hardware filter and the SVM technique has been assessed. The results obtained from the laboratory-based experiment have been analysed and indicate that the SVM approach provides better performance than the passive hardware filter and it can reliably detect discharge signals with apparent charge greater than 30 pC

  20. Characterization and comprehension of corona partial discharge in air under power frequency to very low frequency voltage

    Yuanxiang, ZHOU; Zhongliu, ZHOU; Ling, ZHANG; Yunxiao, ZHANG; Yajun, MO; Jiantao, SUN

    2018-05-01

    For the partial discharge test of electrical equipment with large capacitance, the use of low-frequency voltage instead of power frequency voltage can effectively reduce the capacity requirements of test power supply. However, the validity of PD test under low frequency voltage needs to be evaluated. In order to investigate the influence of voltage frequency on corona discharge in the air, the discharge test of the tip-plate electrode under the frequency from 50 to 0.1 Hz is carried out based on the impulse current method. The results show that some of the main features of corona under low frequency do not change. The magnitude of discharge in a positive half cycle is obviously larger than that in a negative cycle. The magnitude of discharge and interval in positive cycle are random, while that in negative cycle are regular. With the decrease of frequency, the inception voltage increases. The variation trend of maximum and average magnitude and repetition rate of the discharge in positive and negative half cycle with the variation of voltage frequency and magnitude is demonstrated, with discussion and interpretation from the aspects of space charge transportation, effective discharge time and transition of discharge modes. There is an obvious difference in the phase resolved pattern of partial discharge and characteristic parameters of discharge patterns between power and low frequency. The experimental results can be the reference for mode identification of partial discharge under low frequency tests. The trend of the measured parameters with the variation of frequency provides more information about the insulation defect than traditional measurements under a single frequency (usually 50 Hz). Also it helps to understand the mechanism of corona discharge with an explanation of the characteristics under different frequencies.

  1. The influence of spherical cavity surface charge distribution on the sequence of partial discharge events

    Illias, Hazlee A; Chen, George; Lewin, Paul L

    2011-01-01

    In this work, a model representing partial discharge (PD) behaviour of a spherical cavity within a homogeneous dielectric material has been developed to study the influence of cavity surface charge distribution on the electric field distribution in both the cavity and the material itself. The charge accumulation on the cavity surface after a PD event and charge movement along the cavity wall under the influence of electric field magnitude and direction has been found to affect the electric field distribution in the whole cavity and in the material. This in turn affects the likelihood of any subsequent PD activity in the cavity and the whole sequence of PD events. The model parameters influencing cavity surface charge distribution can be readily identified; they are the cavity surface conductivity, the inception field and the extinction field. Comparison of measurement and simulation results has been undertaken to validate the model.

  2. The influence of spherical cavity surface charge distribution on the sequence of partial discharge events

    Illias, Hazlee A [Department of Electrical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur (Malaysia); Chen, George; Lewin, Paul L, E-mail: h.illias@um.edu.my [Tony Davies High Voltage Laboratory, School of Electronics and Computer Science, University of Southampton, Southampton, SO17 1BJ (United Kingdom)

    2011-06-22

    In this work, a model representing partial discharge (PD) behaviour of a spherical cavity within a homogeneous dielectric material has been developed to study the influence of cavity surface charge distribution on the electric field distribution in both the cavity and the material itself. The charge accumulation on the cavity surface after a PD event and charge movement along the cavity wall under the influence of electric field magnitude and direction has been found to affect the electric field distribution in the whole cavity and in the material. This in turn affects the likelihood of any subsequent PD activity in the cavity and the whole sequence of PD events. The model parameters influencing cavity surface charge distribution can be readily identified; they are the cavity surface conductivity, the inception field and the extinction field. Comparison of measurement and simulation results has been undertaken to validate the model.

  3. Partial discharge signal denoising with spatially adaptive wavelet thresholding and support vector machines

    Mota, Hilton de Oliveira; Rocha, Leonardo Chaves Dutra da [Department of Computer Science, Federal University of Sao Joao del-Rei, Visconde do Rio Branco Ave., Colonia do Bengo, Sao Joao del-Rei, MG, 36301-360 (Brazil); Salles, Thiago Cunha de Moura [Department of Computer Science, Federal University of Minas Gerais, 6627 Antonio Carlos Ave., Pampulha, Belo Horizonte, MG, 31270-901 (Brazil); Vasconcelos, Flavio Henrique [Department of Electrical Engineering, Federal University of Minas Gerais, 6627 Antonio Carlos Ave., Pampulha, Belo Horizonte, MG, 31270-901 (Brazil)

    2011-02-15

    In this paper an improved method to denoise partial discharge (PD) signals is presented. The method is based on the wavelet transform (WT) and support vector machines (SVM) and is distinct from other WT-based denoising strategies in the sense that it exploits the high spatial correlations presented by PD wavelet decompositions as a way to identify and select the relevant coefficients. PD spatial correlations are characterized by WT modulus maxima propagation along decomposition levels (scales), which are a strong indicative of the their time-of-occurrence. Denoising is performed by identification and separation of PD-related maxima lines by an SVM pattern classifier. The results obtained confirm that this method has superior denoising capabilities when compared to other WT-based methods found in the literature for the processing of Gaussian and discrete spectral interferences. Moreover, its greatest advantages become clear when the interference has a pulsating or localized shape, situation in which traditional methods usually fail. (author)

  4. Calibration of ultra-high frequency (UHF) partial discharge sensors using FDTD method

    Ishak, Asnor Mazuan; Ishak, Mohd Taufiq

    2018-02-01

    Ultra-high frequency (UHF) partial discharge sensors are widely used for conditioning monitoring and defect location in insulation system of high voltage equipment. Designing sensors for specific applications often requires an iterative process of manufacturing, testing and mechanical modifications. This paper demonstrates the use of finite-difference time-domain (FDTD) technique as a tool to predict the frequency response of UHF PD sensors. Using this approach, the design process can be simplified and parametric studies can be conducted in order to assess the influence of component dimensions and material properties on the sensor response. The modelling approach is validated using gigahertz transverse electromagnetic (GTEM) calibration system. The use of a transient excitation source is particularly suitable for modeling using FDTD, which is able to simulate the step response output voltage of the sensor from which the frequency response is obtained using the same post-processing applied to the physical measurement.

  5. Temperature Effect on Electrical Treeing and Partial Discharge Characteristics of Silicone Rubber-Based Nanocomposites

    Mohd Hafizi Ahmad

    2015-01-01

    Full Text Available This study investigated electrical treeing and its associated phase-resolved partial discharge (PD activities in room-temperature, vulcanized silicone rubber/organomontmorillonite nanocomposite sample materials over a range of temperatures in order to assess the effect of temperature on different filler concentrations under AC voltage. The samples were prepared with three levels of nanofiller content: 0% by weight (wt, 1% by wt, and 3% by wt. The electrical treeing and PD activities of these samples were investigated at temperatures of 20°C, 40°C, and 60°C. The results show that the characteristics of the electrical tree changed with increasing temperature. The tree inception times decreased at 20°C due to space charge dynamics, and the tree growth time increased at 40°C due to the increase in the number of cross-link network structures caused by the vulcanization process. At 60°C, more enhanced and reinforced properties of the silicone rubber-based nanocomposite samples occurred. This led to an increase in electrical tree inception time and electrical tree growth time. However, the PD characteristics, particularly the mean phase angle of occurrence of the positive and negative discharge distributions, were insensitive to variations in temperature. This reflects an enhanced stability in the nanocomposite electrical properties compared with the base polymer.

  6. Development and verification of a software tool for the acoustic location of partial discharge in a power transformer

    Polužanski Vladimir

    2014-01-01

    Full Text Available This paper discusses the development and verification of software tool for determining the location of partial discharge in a power transformer with the acoustic method. Classification and systematization of physical principles and detection methods and tests of partial discharge in power transformers are shown at the beginning of this paper. The most important mathematical models, features, algorithms, and real problems that affect measurement accuracy are highlighted. This paper describes the development and implementation of a software tool for determining the location of partial discharge in a power transformer based on a no iterative mathematical algorithm. Verification and accuracy of measurement are proved both by computer simulation and experimental results available in the literature.

  7. Influence of void defects on partial discharge behavior of superconducting busbar insulation

    Wang, Chunyu; Huang, Xiongyi, E-mail: huangxy@ipp.ac.cn; Lu, Kun; Li, Guoliang; Zhu, Haisheng; Wang, Jun; Wang, Cao; Dai, Zhiheng; Fang, Linlin; Song, Yuntao

    2017-06-15

    Highlights: • PD detection method was used to check the quality of the superconducting busbar insulation. • The samples with different void fraction were manufactured for comparing. • The discharge inception voltage, PRPD pattern was tested and studied for the samples with different void content. • The PD behaviors in oil bath and air condition were compared. - Abstract: For a magnetic confinement fusion device, the superconducting magnets and busbars need to be insulated with one layer of solid insulation to isolate the high voltage potential from the ground. The insulation layer commonly consists of several interleaved layers of epoxy resin-impregnated glass fiber tapes and polyimide films. The traditional electrical inspection methods for such solidified insulation on the magnet and busbar are a DC voltage test or a Paschen test. These tests measure the quality of the insulation based on the value of leakage currents. However, even if there is a larger quantity of high dielectric strength material implemented, if there are some microcavities or delaminations in the insulation system, the leakage current may be limited to microampere levels under testing levels over dozens of kilovolts. Therefore, it is difficult to judge the insulation quality just by the magnitudes of leakage current. Under long-term operation, such imperceptible defects will worsen and finally completely break down the insulation because of partial discharge (PD) incidents. Therefore, a PD detection test is an important complement to the DC voltage and Paschen tests for magnet and busbar insulations in the field of fusion. It is known that the PD detection test is a mature technique in the electric power industry. In this paper, the PD characteristics of samples containing glass fiber-reinforced composite insulations for use with the superconducting busbar were presented and discussed. Various samples with different void contents were prepared and the PD behaviors were tested.

  8. Influence of void defects on partial discharge behavior of superconducting busbar insulation

    Wang, Chunyu; Huang, Xiongyi; Lu, Kun; Li, Guoliang; Zhu, Haisheng; Wang, Jun; Wang, Cao; Dai, Zhiheng; Fang, Linlin; Song, Yuntao

    2017-01-01

    Highlights: • PD detection method was used to check the quality of the superconducting busbar insulation. • The samples with different void fraction were manufactured for comparing. • The discharge inception voltage, PRPD pattern was tested and studied for the samples with different void content. • The PD behaviors in oil bath and air condition were compared. - Abstract: For a magnetic confinement fusion device, the superconducting magnets and busbars need to be insulated with one layer of solid insulation to isolate the high voltage potential from the ground. The insulation layer commonly consists of several interleaved layers of epoxy resin-impregnated glass fiber tapes and polyimide films. The traditional electrical inspection methods for such solidified insulation on the magnet and busbar are a DC voltage test or a Paschen test. These tests measure the quality of the insulation based on the value of leakage currents. However, even if there is a larger quantity of high dielectric strength material implemented, if there are some microcavities or delaminations in the insulation system, the leakage current may be limited to microampere levels under testing levels over dozens of kilovolts. Therefore, it is difficult to judge the insulation quality just by the magnitudes of leakage current. Under long-term operation, such imperceptible defects will worsen and finally completely break down the insulation because of partial discharge (PD) incidents. Therefore, a PD detection test is an important complement to the DC voltage and Paschen tests for magnet and busbar insulations in the field of fusion. It is known that the PD detection test is a mature technique in the electric power industry. In this paper, the PD characteristics of samples containing glass fiber-reinforced composite insulations for use with the superconducting busbar were presented and discussed. Various samples with different void contents were prepared and the PD behaviors were tested.

  9. Wireless Sensor Network for Radiometric Detection and Assessment of Partial Discharge in High-Voltage Equipment

    Upton, D. W.; Saeed, B. I.; Mather, P. J.; Lazaridis, P. I.; Vieira, M. F. Q.; Atkinson, R. C.; Tachtatzis, C.; Garcia, M. S.; Judd, M. D.; Glover, I. A.

    2018-03-01

    Monitoring of partial discharge (PD) activity within high-voltage electrical environments is increasingly used for the assessment of insulation condition. Traditional measurement techniques employ technologies that either require off-line installation or have high power consumption and are hence costly. A wireless sensor network is proposed that utilizes only received signal strength to locate areas of PD activity within a high-voltage electricity substation. The network comprises low-power and low-cost radiometric sensor nodes which receive the radiation propagated from a source of PD. Results are reported from several empirical tests performed within a large indoor environment and a substation environment using a network of nine sensor nodes. A portable PD source emulator was placed at multiple locations within the network. Signal strength measured by the nodes is reported via WirelessHART to a data collection hub where it is processed using a location algorithm. The results obtained place the measured location within 2 m of the actual source location.

  10. An Intelligent Sensor for the Ultra-High-Frequency Partial Discharge Online Monitoring of Power Transformers

    Jian Li

    2016-05-01

    Full Text Available Ultra-high-frequency (UHF partial discharge (PD online monitoring is an effective way to inspect potential faults and insulation defects in power transformers. The construction of UHF PD online monitoring system is a challenge because of the high-frequency and wide-frequency band of the UHF PD signal. This paper presents a novel, intelligent sensor for UHF PD online monitoring based on a new method, namely a level scanning method. The intelligent sensor can directly acquire the statistical characteristic quantities and is characterized by low cost, few data to output and transmit, Ethernet functionality, and small size for easy installation. The prototype of an intelligent sensor was made. Actual UHF PD experiments with three typical artificial defect models of power transformers were carried out in a laboratory, and the waveform recording method and intelligent sensor proposed were simultaneously used for UHF PD measurement for comparison. The results show that the proposed intelligent sensor is qualified for the UHF PD online monitoring of power transformers. Additionally, three methods to improve the performance of intelligent sensors were proposed according to the principle of the level scanning method.

  11. Use of ultrasonic array method for positioning multiple partial discharge sources in transformer oil.

    Xie, Qing; Tao, Junhan; Wang, Yongqiang; Geng, Jianghai; Cheng, Shuyi; Lü, Fangcheng

    2014-08-01

    Fast and accurate positioning of partial discharge (PD) sources in transformer oil is very important for the safe, stable operation of power systems because it allows timely elimination of insulation faults. There is usually more than one PD source once an insulation fault occurs in the transformer oil. This study, which has both theoretical and practical significance, proposes a method of identifying multiple PD sources in the transformer oil. The method combines the two-sided correlation transformation algorithm in the broadband signal focusing and the modified Gerschgorin disk estimator. The method of classification of multiple signals is used to determine the directions of arrival of signals from multiple PD sources. The ultrasonic array positioning method is based on the multi-platform direction finding and the global optimization searching. Both the 4 × 4 square planar ultrasonic sensor array and the ultrasonic array detection platform are built to test the method of identifying and positioning multiple PD sources. The obtained results verify the validity and the engineering practicability of this method.

  12. Antenna Deployment for the Localization of Partial Discharges in Open-Air Substations

    Robles, Guillermo; Fresno, José Manuel; Sánchez-Fernández, Matilde; Martínez-Tarifa, Juan Manuel

    2016-01-01

    Partial discharges are ionization processes inside or on the surface of dielectrics that can unveil insulation problems in electrical equipment. The charge accumulated is released under certain environmental and voltage conditions attacking the insulation both physically and chemically. The final consequence of a continuous occurrence of these events is the breakdown of the dielectric. The electron avalanche provokes a derivative of the electric field with respect to time, creating an electromagnetic impulse that can be detected with antennas. The localization of the source helps in the identification of the piece of equipment that has to be decommissioned. This can be done by deploying antennas and calculating the time difference of arrival (TDOA) of the electromagnetic pulses. However, small errors in this parameter can lead to great displacements of the calculated position of the source. Usually, four antennas are used to find the source but the array geometry has to be correctly deployed to have minimal errors in the localization. This paper demonstrates, by an analysis based on simulation and also experimentally, that the most common layouts are not always the best options and proposes a simple antenna layout to reduce the systematic error in the TDOA calculation due to the positions of the antennas in the array. PMID:27092501

  13. Resonant Frequency Calculation and Optimal Design of Peano Fractal Antenna for Partial Discharge Detection

    Jian Li

    2012-01-01

    Full Text Available Ultra-high-frequency (UHF approaches have caught increasing attention recently and have been considered as a promising technology for online monitoring partial discharge (PD signals. This paper presents a Peano fractal antenna for UHF PD online monitoring of transformer with small size and multiband. The approximate formula for calculating the first resonant frequency of the Peano fractal antenna is presented. The results show that the first resonant frequency of the Peano fractal antenna is smaller than the Hilbert fractal antenna when the outer dimensions are equivalent approximately. The optimal geometric parameters of the antenna were obtained through simulation. Actual PD experiments had been carried out for two typically artificial insulation defect models, while the proposed antenna and the existing Hilbert antenna were both used for the PD measurement. The experimental results show that Peano fractal antenna is qualified for PD online UHF monitoring and a little more suitable than the Hilbert fractal antenna for pattern recognition by analyzing the waveforms of detected UHF PD signals.

  14. A lower dimensional feature vector for identification of partial discharges of different origin using time measurements

    Evagorou, Demetres; Kyprianou, Andreas; Georghiou, George E; Lewin, Paul L; Stavrou, Andreas

    2012-01-01

    Partial discharge (PD) classification into sources of different origin is essential in evaluating the severity of the damage caused by its activity on the insulation of power cables and their accessories. More specifically, some types of PD can be classified as having a detrimental effect on the integrity of the insulation while others can be deemed relatively harmless, rendering the correct classification of different PD types of vital importance to electrical utilities. In this work, a feature vector was proposed based on higher order statistics on selected nodes of the wavelet packet transform (WPT) coefficients of time domain measurements, which can compactly represent the characteristics of different PD sources. To assess its performance, experimental data acquired under laboratory conditions for four different PD sources encountered in power systems were used. The two learning machine methods, namely the support vector machine and the probabilistic neural network, employed as the classification algorithms, achieved overall classification rates of around 98%. In comparison, the utilization of the scaled, raw WPT coefficients as a feature vector resulted in classification accuracy of around 99%, but with a significantly higher number of dimensions (1304 to 16), validating the PD identification ability of the proposed feature. Dimensionality reduction becomes a key factor in online, real-time data collection and processing of PD measurements, reducing the classification effort and the data-storage requirements. Therefore, the proposed method can constitute a potential tool for such online measurements, after addressing issues related to on-site measurements such as the rejection of interference. (paper)

  15. Evaluation efficiency for mobile as discharge measurement device for partially filled circular channel

    I.M.H. Rashwan

    2013-06-01

    Full Text Available Discharge measurement is an important step in engineering applications such as sewerage system, irrigation and drainage system. Mobile flume is a simple and low-cost discharge measuring device constructed of two pieces of pipes, one installed vertically inside the other. The circular mobile flume depends on the concept of developing a contracted zone to have a control section. To evaluate the efficiency of this type of device mathematical and experimental studies are presented. Specific energy, discharge and Froude number equations are used to develop mathematical model. Experimental work is carried out to measure the discharge values corresponding to the specific energy values. The experimental data is used to evaluate the mobile flume as a device to measure discharge. A new equation for the discharge coefficient is presented. This equation can be used to determined accurate discharge with knowing the contraction ratio and measured specific energy.

  16. Partial discharge tests and characterisation of the Advanced Photon Source linac modulator cables

    Cours, A.

    2007-01-01

    The advanced photon source (APS) linac modulators are PFN-type pulsers with switch-mode charging power supplies (PSs). The PS and the PFN are connected to each other by 15 feet of 100-kV x-ray cable, with the PFN end of the cable terminated with a connector that was confirmed partial-discharge (PD)-free up to 38 kV ac (53.5 kV peak). Another end of the cable is terminated with a connector that was designed by the PS manufacturer and cannot easily be replaced with another type of connector, since part of it is located inside the densely packed PS. PD tests of the cables with this type of connector show that the PD inception voltages (PDIVs) in different cables turn out to be located within a wide voltage range: 21 to 27 kV ac that corresponds to 29 to 38 kV peak. In order to evaluate the insulation condition of the modulator cables, detect insulation deterioration, and ensure failure-preventing equipment maintenance, over the last two years the PDIVs of all high-voltage (HV) cables in use in the modulators have been tested about every three and a half months. Before the tests, all cables were removed from the equipment, carefully cleaned, inspected, and regreased. The tests were performed using a 40-kV PD detector. The test results show that: 1 The PDIVs remain almost unchanged in all tested cables. 2 From test to test, the PDIV of any particular cable may slightly oscillate around some average value. This possibly depends on the connector regreasing technique. 3 There is no direct evidence of cable insulation deterioration during more than two years of operation under voltage higher than the PD inception level.

  17. Artificial Neural Network Application for Partial Discharge Recognition: Survey and Future Directions

    Abdullahi Abubakar Mas’ud

    2016-07-01

    Full Text Available In order to investigate how artificial neural networks (ANNs have been applied for partial discharge (PD pattern recognition, this paper reviews recent progress made on ANN development for PD classification by a literature survey. Contributions from several authors have been presented and discussed. High recognition rate has been recorded for several PD faults, but there are still many factors that hinder correct recognition of PD by the ANN, such as high-amplitude noise or wide spectral content typical from industrial environments, trial and error approaches in determining an optimum ANN, multiple PD sources acting simultaneously, lack of comprehensive and up to date databank of PD faults, and the appropriate selection of the characteristics that allow a correct recognition of the type of source which are currently being addressed by researchers. Several suggestions for improvement are proposed by the authors include: (1 determining the optimum weights in training the ANN; (2 using PD data captured over long stressing period in training the ANN; (3 ANN recognizing different PD degradation levels; (4 using the same resolution sizes of the PD patterns when training and testing the ANN with different PD dataset; (5 understanding the characteristics of multiple concurrent PD faults and effectively recognizing them; and (6 developing techniques in order to shorten the training time for the ANN as applied for PD recognition Finally, this paper critically assesses the suitability of ANNs for both online and offline PD detections outlining the advantages to the practitioners in the field. It is possible for the ANNs to determine the stage of degradation of the PD, thereby giving an indication of the seriousness of the fault.

  18. Development of acoustic partial discharge detection device; Bubun hoden kenshutsusochi wo riyo shita onkyo niyoru hendensetsubi no zetsuen rekka shindan gijutsu no kaihatsu

    Suenaga, Kiyoka [Kawasaki Steel Corp., Tokyo (Japan)

    1999-06-15

    This paper introduces an acoustic partial discharge detection device, consisting of a microphone, amplifier circuit for analog signals, A/D (Digital Signal Processor). This device has the following unique characteristics: (1) Judging whether or not there is partial discharge by analyzing supersonic signals. (2) High sensitivity for detecting discharge ; 100 pC from a distance of 1.2 m. (3)Locating the position of discharge occurrence by using a sharpe directional parabola microphone and laser beam pointer. The detector was used in the steel works to detect partial discharge on high-voltage electrical apparatus, where faults due to partial discharge were found in the potential transformer and current transformer. The effectiveness of the device was thus verified. (author)

  19. A Comparison of Inductive Sensors in the Characterization of Partial Discharges and Electrical Noise Using the Chromatic Technique

    Jorge Alfredo Ardila-Rey

    2018-03-01

    Full Text Available Partial discharges (PDs are one of the most important classes of ageing processes that occur within electrical insulation. PD detection is a standardized technique to qualify the state of the insulation in electric assets such as machines and power cables. Generally, the classical phase-resolved partial discharge (PRPD patterns are used to perform the identification of the type of PD source when they are related to a specific degradation process and when the electrical noise level is low compared to the magnitudes of the PD signals. However, in practical applications such as measurements carried out in the field or in industrial environments, several PD sources and large noise signals are usually present simultaneously. In this study, three different inductive sensors have been used to evaluate and compare their performance in the detection and separation of multiple PD sources by applying the chromatic technique to each of the measured signals.

  20. A Comparison of Inductive Sensors in the Characterization of Partial Discharges and Electrical Noise Using the Chromatic Technique.

    Ardila-Rey, Jorge Alfredo; Montaña, Johny; de Castro, Bruno Albuquerque; Schurch, Roger; Covolan Ulson, José Alfredo; Muhammad-Sukki, Firdaus; Bani, Nurul Aini

    2018-03-29

    Partial discharges (PDs) are one of the most important classes of ageing processes that occur within electrical insulation. PD detection is a standardized technique to qualify the state of the insulation in electric assets such as machines and power cables. Generally, the classical phase-resolved partial discharge (PRPD) patterns are used to perform the identification of the type of PD source when they are related to a specific degradation process and when the electrical noise level is low compared to the magnitudes of the PD signals. However, in practical applications such as measurements carried out in the field or in industrial environments, several PD sources and large noise signals are usually present simultaneously. In this study, three different inductive sensors have been used to evaluate and compare their performance in the detection and separation of multiple PD sources by applying the chromatic technique to each of the measured signals.

  1. On the Feasibility of Gap Detection of Power Transformer Partial Discharge UHF Signals: Gap Propagation Characteristics of Electromagnetic Waves

    Xiaoxing Zhang; Guozhi Zhang; Yalong Li; Jian Zhang; Rui Huang

    2017-01-01

    This study analyzed the transformer electromagnetic gap propagation characteristics. The influence of gap size is also analyzed, and the results experimentally verified. The obtained results indicated that the gap propagation characteristics of electromagnetic wave signals radiated by the partial discharge (PD) source in different directions are substantially different. The intensity of the electromagnetic wave in the gap reaches a maximum at a gap height of 1 cm; and inside the gap, the inte...

  2. Partial discharge location technique for covered-conductor overhead distribution lines

    Isa, M.

    2013-02-01

    In Finland, covered-conductor (CC) overhead lines are commonly used in medium voltage (MV) networks because the loads are widely distributed in the forested terrain. Such parts of the network are exposed to leaning trees which produce partial discharges (PDs) in CC lines. This thesis presents a technique to locate the PD source on CC overhead distribution line networks. The algorithm is developed and tested using a simulated study and experimental measurements. The Electromagnetic Transient Program-Alternative Transient Program (EMTP-ATP) is used to simulate and analyze a three-phase PD monitoring system, while MATLAB is used for post-processing of the high frequency signals which were measured. A Rogowski coil is used as the measuring sensor. A multi-end correlation-based technique for PD location is implemented using the theory of maximum correlation factor in order to find the time difference of arrival (TDOA) between signal arrivals at three synchronized measuring points. The three stages of signal analysis used are: (1) denoising by applying discrete wavelet transform (DWT); (2) extracting the PD features using the absolute or windowed standard deviation (STD) and; (3) locating the PD point. The advantage of this technique is the ability to locate the PD source without the need to know the first arrival time and the propagation velocity of the signals. In addition, the faulty section of the CC line between three measuring points can also be identified based on the degrees of correlation. An experimental analysis is performed to evaluate the PD measurement system performance for PD location on CC overhead lines. The measuring set-up is arranged in a high voltage (HV) laboratory. A multi-end measuring method is chosen as a technique to locate the PD source point on the line. A power transformer 110/20 kV was used to energize the AC voltage up to 11.5 kV/phase (20 kV system). The tests were designed to cover different conditions such as offline and online

  3. An all-fiber partial discharge monitoring system based on both intrinsic fiber optic interferometry sensor and fluorescent fiber

    Yin, Zelin; Zhang, Ruirui; Tong, Jie; Chen, Xi

    2013-12-01

    Partial discharges (PDs) are an electrical phenomenon that occurs within a transformer whenever the voltage stress is sufficient to produce ionization in voids or inclusions within a solid dielectric, at conductor/dielectric interfaces, or in bubbles within liquid dielectrics such as oil; high-frequency transient current discharges will then appear repeatedly and will progressively deteriorate the insulation, ultimately leading to breakdown. Fiber sensor has great potential on the partial discharge detection in high-voltage equipment for its immunity to electromagnetic interference and it can take direct measurement in the high voltage equipment. The energy released in PDs produces a number of effects, resulting in flash, chemical and structural changes and electromagnetic emissions and so on. Acoustic PD detection is based on the mechanical pressure wave emitted from the discharge and fluorescent fiber PD detection is based on the emitted light produced by ionization, excitation and recombination processes during the discharge. Both of the two methods have the shortage of weak anti-interference capacity in the physical environment, like thunder or other sound source. In order to avoid the false report, an all-fiber combined PD detection system of the two methods is developed in this paper. In the system the fluorescent fiber PD sensor is considered as a reference signal, three F-P based PD detection sensors are used to both monitor the PD intensity and calculate the exact position of the discharge source. Considering the wave band of the F-P cavity and the fluorescent probe are quite different, the reflection spectrum of the F-P cavity is in the infrared region, however the fluorescent probe is about 600nm to 700nm, thus the F-P sensor and fluorescent fiber probe can be connected in one fiber and the reflection light can be detected by two different detectors without mutual interference. The all-fiber partial discharge monitoring system not only can detect the PDs

  4. Partial discharge patterns and surface deterioration in voids in filled and unfilled epoxy

    Holbøll, Joachim; Henriksen, Mogens

    1992-01-01

    /height analyses were performed over a period of 2400 h and showed very characteristic discharge patterns for each material combination. A unique behavior with regard to changes of pulse repetition rate and maximum apparent charge was observed for PD in alumina- and silica-filled epoxy. The void surfaces were...

  5. 77 FR 58830 - State Program Requirements; Application To Administer Partial National Pollutant Discharge...

    2012-09-24

    .... ODAFF does not have jurisdiction over storm water discharges associated with industrial activity (as defined at 40 CFR 122.26(b)(14)) at facilities whose primary industrial activity is storage of grain, feed... regulated by ODAFF that only incidentally store grain, feed, seed, fertilizer, and agriculture chemicals to...

  6. On the Use of Monopole Antennas for Determining the Effect of the Enclosure of a Power Transformer Tank in Partial Discharges Electromagnetic Propagation.

    Albarracín, Ricardo; Ardila-Rey, Jorge Alfredo; Mas'ud, Abdullahi Abubakar

    2016-01-25

    A well-defined condition-monitoring for power transformers is key to implementing a correct condition-based maintenance (CBM). In this regard, partial discharges (PD) measurement and its analysis allows to carry out on-line maintenance following the standards IEC-60270 and IEC-60076. However, new PD measurements techniques, such as acoustics or electromagnetic (EM) acquisitions using ultra-high-frequency (UHF) sensors are being taken into account, IEC-62478. PD measurements with antennas and the effect of their EM propagation in power transformer tanks is an open research topic that is considered in this paper. In this sense, an empty tank model is studied as a rectangular cavity and their resonances are calculated and compared with their measurement with a network analyser. Besides, two low cost improved monopole antennas deployed inside and outside of the tank model capture background noise and PD pulses in three different test objects (Nomex, twisted pair and insulator). The average spectrum of them are compared and can be found that mainly, the antenna frequency response, the frequency content distribution depending on the PD source and the enclosure resonances modes are the main factors to be considered in PD acquisitions with these sensors. Finally, with this set-up, it is possible to measure PD activity inside the tank from outside.

  7. Development of a perpendicular vibration-induced electrical discharge machining process for fabrication of partially wavy inner structures

    Lee, Ju Chul; Park, Sang Hu; Min, June Kee; Ha, Man Yeong; Shin, Bo Sung [Pusan National University, Busan (Korea, Republic of); Cho, Jong Rae [Korea Maritime University, Busan (Korea, Republic of)

    2016-05-15

    Heat transfer enhancement is an important issue in energy systems. To improve the efficiency of a cooling channel used inside injection molds, turbine blades, and high-temperature devices, channels with various shapes, such as wavy, elliptical, and twisted, have been studied. A cooling channel with a partially wavy inner structure has shown outstanding cooling performance despite a small increase in friction factor. However, generating a partially wavy inner structure inside a channel through conventional machining processes is not easy. To address this problem, we developed a new process called Perpendicular vibration-induced electrical discharge machining (PV-EDM). A specific electrode and one- and random-directional vibrating devices controlled by a pneumatic load were designed for the PV-EDM process. Experimental results showed that local shaping on the inner wall of a channel is possible, which confirmed the possibility of application of this process to actual industrial problems.

  8. Defect Pattern Recognition Based on Partial Discharge Characteristics of Oil-Pressboard Insulation for UHVDC Converter Transformer

    Wen Si

    2018-03-01

    Full Text Available The ultra high voltage direct current (UHVDC transmission system has advantages in delivering electrical energy over long distance at high capacity. UHVDC converter transformer is a key apparatus and its insulation state greatly affects the safe operation of the transmission system. Partial discharge (PD characteristics of oil-pressboard insulation under combined AC-DC voltage are the foundation for analyzing the insulation state of UHVDC converter transformers. The defect pattern recognition based on PD characteristics is an important part of the state monitoring of converter transformers. In this paper, PD characteristics are investigated with the established experimental platform of three defect models (needle-plate, surface discharge and air gap under 1:1 combined AC-DC voltage. The different PD behaviors of three defect models are discussed and explained through simulation of electric field strength distribution and discharge mechanism. For the recognition of defect types when multiple types of sources coexist, the Random Forests algorithm is used for recognition. In order to reduce the computational layer and the loss of information caused by the extraction of traditional features, the preprocessed single PD pulses and phase information are chosen to be the features for learning and test. Zero-padding method is discussed for normalizing the features. Based on the experimental data, Random Forests and Least Squares Support Vector Machine are compared in the performance of computing time, recognition accuracy and adaptability. It is proved that Random Forests is more suitable for big data analysis.

  9. Dielectric strength behaviour and mechanical properties of transparent insulation materials suitable to optical monitoring of partial discharges

    Lothongkam, Chaiyaporn

    2014-01-01

    A novel optical detection method for partial discharge in HV/EHV cable terminations has been proposed. Optical sensor fibres integrated into the HV equipment provide high sensitivity as well as immunity to electromagnetic interference and enable therefore on-line monitoring in electromagnetically noisy environment. The availability of optically transparent silicone rubbers that meet strict dielectric and mechanical criteria is a crucial prerequisite for the implementation of this method. The optically transparent silicone rubbers can be applied for the fabrication of a modern rubber stress cone as well as for the development of a new optical sensing element sensitive to PD activities. In this thesis, AC dielectric strength behaviour and mechanical properties of three types of commercially available silicone rubbers were investigated. One of the characterized silicone rubbers was a translucent type whereas the two others were optically transparent types, however with different chemical curing reactions. The measurements of tensile strength and elongation at break were carried out according to the ISO 37 standard. For investigation of the dielectric strength E b behaviour of the virgin and modified silicone rubbers, a new methodology was developed. It is, at the same time, highly reliable and efficient, saves time and reduces material consumption in comparison to previously reported methodologies. The key component of this methodology is a specifically developed test facility. Furthermore, the methodology comprises determinations for easy preparation and handling of high-quality test specimens. This test method provides various advantages over other methods that have previously been used for measurement of the fundamental quantity E b value of silicone rubbers. Both technical and economic demands are satisfied. The new facility also enables cost-effective routine tests in material research laboratories. The high quality of the obtained test results was verified by

  10. Effect of electric field configuration on streamer and partial discharge phenomena in a hydrocarbon insulating liquid under AC stress

    Liu, Z; Liu, Q; Wang, Z D

    2016-01-01

    This paper concerns pre-breakdown phenomena, including streamer characteristics from a fundamental perspective and partial discharge (PD) measurements from an industrial perspective, in a hydrocarbon insulating liquid. The aim was to investigate the possible changes of the liquid’s streamer and PD characteristics and their correlations when the uniformity of the AC electric field varies. In the experiments, a plane-to-plane electrode system incorporating a needle protrusion was used in addition to a needle-to-plane electrode system. When the applied electric field became more uniform, fewer radial branches occurred and streamer propagation towards the ground electrode was enhanced. The transition from streamer propagation dominated breakdown in divergent fields to streamer initiation dominated breakdown in uniform fields was evidenced. Relationships between streamer and PD characteristics were established, which were found to be electric field dependent. PD of the same apparent charge would indicate longer streamers if the electric field is more uniform. (paper)

  11. On the Feasibility of Gap Detection of Power Transformer Partial Discharge UHF Signals: Gap Propagation Characteristics of Electromagnetic Waves

    Xiaoxing Zhang

    2017-10-01

    Full Text Available This study analyzed the transformer electromagnetic gap propagation characteristics. The influence of gap size is also analyzed, and the results experimentally verified. The obtained results indicated that the gap propagation characteristics of electromagnetic wave signals radiated by the partial discharge (PD source in different directions are substantially different. The intensity of the electromagnetic wave in the gap reaches a maximum at a gap height of 1 cm; and inside the gap, the intensity of the electromagnetic wave depicted an increasing trend at the tail area of the gap. Finally, from the obtained results, some suggestions on where to install sensors in practical systems for ultra high frequency (UHF PD signal detection in the transformer gap are provided. The obtained results confirmed the feasibility of using this approach. These results can be seen as a benchmark and a challenge for further research in this field.

  12. Influences of Traction Load Shock on Artificial Partial Discharge Faults within Traction Transformer—Experimental Test for Pattern Recognition

    Shuaibing Li

    2017-10-01

    Full Text Available Partial discharge (PD measurement and its pattern recognition are vital to fault diagnosis of transformers, especially to those traction substation transformers undergoing repetitive traction load shocks. This paper presents the primary factors induced by traction load shocks including high total harmonics distortion (THD, transient voltage impulse and high-temperature rise, and their effects on the feature parameters of PD. Experimental tests are conducted on six artificial PD models with these factors introduced one by one. Results reveal that the maximum PD quantity and the PD repetitive rate are favorable to be enlarged when the oil temperature exceeds 80 °C or the THD is higher than 16% with certain orders of harmonic. The decline in PD inception voltage can mainly be attributed to the transient voltage impulse. The variation in central frequency of the fast Fourier transformation (FFT spectra transformed from ultra-high frequency signals can mainly be attributed to high THD, especially when it exceeds 20%. The temperature rise has no significant influence on the FFT spectra; the transient voltage impulse, however, can result in a central frequency shift of the floating particle discharge. With the rapid development of high-speed railways, the study presented in this paper will be helpful for field PD detection and recognition of traction substation transformers in the future.

  13. Limpieza de patrones φ,q,n de descargas parciales; Denoising of partial discharge φ,q,n patterns

    Santiago Alfredo Dorrbercker Drake

    2015-04-01

    Full Text Available La medición de descargas parciales (DP se sustenta en la detección y filtraje de pulsos de corriente que aparecen en una banda de frecuencia que abarca desde los kilohertzios hasta los gigahertzios, por tal motivo los detectores de descargas parciales (DDP poseen sistemas para desagregar dichos pulsos de corriente. Sin embargo, los DDP también permiten el paso de otras señales de alta frecuencia (ruidos que se mezclan con los pulsos de DP y afectan la medición, interpretación y caracterización de las DP. Para atenuar ese efecto, se han desarrollado distintas técnicas para separar los ruidos tanto asociados a las señales como los existentes en los patrones φ,q,n.  En este artículo se presentan los resultados obtenidos en la reducción de los ruidos asociados a la conmutación de tiristores y los ruidos esporádicos, de los patrones φ,q,n mediante el empleo de técnicas de procesamiento de imágenes digitales. The measurement of partial (PD discharges is sustained in the detection and filtration of current pulses which appear in a band of frequency that include from the kilohertz until the gigahertzios, for such a reason the detectors of partial (PDD discharges they possess systems for the separation of this current pulses. However, PDD also allows the step of other signals of high frequency, denominated noises, that mix with the pulses of PD and they affect measurement, interpretation and characterization of PD. To attenuate that effect, different techniques have been developed to separate the noises so much associated to the signs like the existent ones in the φ,q,n patterns. In this paper are presented the results obtained in the noise reduction of the noises associated to the thyristor’s commutation and the sporadic noises, in the φ,q,n patterns by means of the technical of digital images processing

  14. Partial discharge characteristics of polymer nanocomposite materials in electrical insulation: a review of sample preparation techniques, analysis methods, potential applications, and future trends.

    Izzati, Wan Akmal; Arief, Yanuar Z; Adzis, Zuraimy; Shafanizam, Mohd

    2014-01-01

    Polymer nanocomposites have recently been attracting attention among researchers in electrical insulating applications from energy storage to power delivery. However, partial discharge has always been a predecessor to major faults and problems in this field. In addition, there is a lot more to explore, as neither the partial discharge characteristic in nanocomposites nor their electrical properties are clearly understood. By adding a small amount of weight percentage (wt%) of nanofillers, the physical, mechanical, and electrical properties of polymers can be greatly enhanced. For instance, nanofillers in nanocomposites such as silica (SiO2), alumina (Al2O3) and titania (TiO2) play a big role in providing a good approach to increasing the dielectric breakdown strength and partial discharge resistance of nanocomposites. Such polymer nanocomposites will be reviewed thoroughly in this paper, with the different experimental and analytical techniques used in previous studies. This paper also provides an academic review about partial discharge in polymer nanocomposites used as electrical insulating material from previous research, covering aspects of preparation, characteristics of the nanocomposite based on experimental works, application in power systems, methods and techniques of experiment and analysis, and future trends.

  15. UHF Signal Processing and Pattern Recognition of Partial Discharge in Gas-Insulated Switchgear Using Chromatic Methodology.

    Wang, Xiaohua; Li, Xi; Rong, Mingzhe; Xie, Dingli; Ding, Dan; Wang, Zhixiang

    2017-01-18

    The ultra-high frequency (UHF) method is widely used in insulation condition assessment. However, UHF signal processing algorithms are complicated and the size of the result is large, which hinders extracting features and recognizing partial discharge (PD) patterns. This article investigated the chromatic methodology that is novel in PD detection. The principle of chromatic methodologies in color science are introduced. The chromatic processing represents UHF signals sparsely. The UHF signals obtained from PD experiments were processed using chromatic methodology and characterized by three parameters in chromatic space ( H , L , and S representing dominant wavelength, signal strength, and saturation, respectively). The features of the UHF signals were studied hierarchically. The results showed that the chromatic parameters were consistent with conventional frequency domain parameters. The global chromatic parameters can be used to distinguish UHF signals acquired by different sensors, and they reveal the propagation properties of the UHF signal in the L-shaped gas-insulated switchgear (GIS). Finally, typical PD defect patterns had been recognized by using novel chromatic parameters in an actual GIS tank and good performance of recognition was achieved.

  16. Study on the Application of an Ultra-High-Frequency Fractal Antenna to Partial Discharge Detection in Switchgears

    Chenguo Yao

    2013-12-01

    Full Text Available The ultra-high-frequency (UHF method is used to analyze the insulation condition of electric equipment by detecting the UHF electromagnetic (EM waves excited by partial discharge (PD. As part of the UHF detection system, the UHF sensor determines the detection system performance in signal extraction and recognition. In this paper, a UHF antenna sensor with the fractal structure for PD detection in switchgears was designed by means of modeling, simulation and optimization. This sensor, with a flat-plate structure, had two resonance frequencies of 583 MHz and 732 MHz. In the laboratory, four kinds of insulation defect models were positioned in the testing switchgear for typical PD tests. The results show that the sensor could reproduce the electromagnetic waves well. Furthermore, to optimize the installation position of the inner sensor for achieving best detection performance, the precise simulation model of switchgear was developed to study the propagation characteristics of UHF signals in switchgear by finite-difference time-domain (FDTD method. According to the results of simulation and verification test, the sensor should be positioned at the right side of bottom plate in the front cabinet. This research established the foundation for the further study on the application of UHF technique in switchgear PD online detection.

  17. A Novel High-Performance Beam-Supported Membrane Structure with Enhanced Design Flexibility for Partial Discharge Detection

    Chenzhao Fu

    2017-03-01

    Full Text Available A novel beam-supported membrane (BSM structure for the fiber optic extrinsic Fabry-Perot interferometer (EFPI sensors showing an enhanced performance and an improved resistance to the temperature change was proposed for detecting partial discharges (PDs. The fundamental frequency, sensitivity, linear range, and flatness of the BSM structure were investigated by employing the finite element simulations. Compared with the intact membrane (IM structure commonly used by EFPI sensors, BSM structure provides extra geometrical parameters to define the fundamental frequency when the diameter of the whole membrane and its thickness is determined, resulting in an enhanced design flexibility of the sensor structure. According to the simulation results, it is noted that BSM structure not only shows a much higher sensitivity (increased by almost four times for some cases, and a wider working range of fundamental frequency to choose, but also an improved linear range, making the system development much easier. In addition, BSM structure presents a better flatness than its IM counterpart, providing an increased signal-to-noise ratio (SNR. A further improvement of performance is thought to be possible with a step-forward structural optimization. The BSM structure shows a great potential to design the EFPI sensors, as well as others for detecting the acoustic signals.

  18. Moisture Migration in an Oil-Paper Insulation System in Relation to Online Partial Discharge Monitoring of Power Transformers

    Wojciech Sikorski

    2016-12-01

    Full Text Available Most power transformers operating in a power system possess oil-paper insulation. A serious defect of this type of insulation, which is associated with long operation time, is an increase in the moisture content. Moisture introduces a number of threats to proper operation of the transformer, e.g., ignition of partial discharges (PDs. Due to the varying temperature of the insulation system during the unit’s normal operation, a dynamic change (migration of water takes place, precipitating the oil-paper system from a state of hydrodynamic equilibrium. This causes the PDs to be variable in time, and they may intensify or extinguish. Studies on model objects have been conducted to determine the conditions (temperature, humidity, time that will have an impact on the ignition and intensity of the observed phenomenon of PDs. The conclusions of this study will have a practical application in the evaluation of measurements conducted in the field, especially in relation to the registration of an online PD monitoring system.

  19. Characteristics of Partial Discharge and Ozone Generation for Twisted-pair of Enameled Wires under High-repetitive Impulse Voltage Application

    Kanazawa, Seiji; Enokizono, Masato; Shibakita, Toshihide; Umehara, Eiji; Toshimitsu, Jun; Ninomiya, Shinji; Taniguchi, Hideki; Abe, Yukari

    In recent years, inverter drive machines such as a hybrid vehicle and an electric vehicle are operated under high voltage pulse with high repetition rate. In this case, inverter surge is generated and affected the machine operation. Especially, the enameled wire of a motor is deteriorated due to the partial discharge (PD) and finally breakdown of the wire will occur. In order to investigate a PD on a resistant enameled wire, characteristics of PD in the twisted pair sample under bipolar repetitive impulse voltages are investigated experimentally. The relationship between the applied voltage and discharge current was measured at PD inception and extinction, and we estimated the repetitive PD inception and extinction voltages experimentally. The corresponding optical emission of the discharge was also observed by using an ICCD camera. Furthermore, ozone concentration due to the discharge was measured during the life-time test of the resistant enameled wires from a working environmental point of view.

  20. Influence of N2 partial pressure on structural and microhardness properties of TiN/ZrN multilayers deposited by Ar/N2 vacuum arc discharge

    Naddaf, M.; Abdallah, B.; Ahmad, M.; A-Kharroub, M.

    2016-08-01

    The influence of N2 partial pressure on structural, mechanical and wetting properties of multilayered TiN/ZrN thin films deposited on silicon substrates by vacuum arc discharge of (N2 + Ar) gas mixtures is investigated. X-ray diffraction (XRD) results show that the average texturing coefficient of (1 1 1) orientation and the grain size of both TiN and ZrN individual layers increase with increasing the N2 partial pressure. The Rutherford back scattering (RBS) measurements and analysis reveal that incorporation of the nitrogen in the film increases with increasing the N2 partial pressure and both TiN and ZrN individual layers have a nitrogen over-stoichiometry for N2 partial pressure ⩾50%. The change in the film micro-hardness is correlated to the changes in crystallographic texture, grain size, stoichiometry and the residual stress in the film as a function of the N2 partial pressure. In particular, stoichiometry of ZrN and TiN individual is found to play the vital role in determining the multilayer hardness. The multilayer film deposited at N2 partial pressure of 25% has the best stoichiometric ratio of both TiN and ZrN layers and the highest micro-hardness of about 32 GPa. In addition, water contact angle (WCA) measurements and analysis show a decrease in the work of adhesion on increasing the N2 partial pressure.

  1. Influence of N_2 partial pressure on structural and microhardness properties of TiN/ZrN multilayers deposited by Ar/N_2 vacuum arc discharge

    Naddaf, M.; Abdallah, B.; Ahmad, M.; A-Kharroub, M.

    2016-01-01

    The influence of N_2 partial pressure on structural, mechanical and wetting properties of multilayered TiN/ZrN thin films deposited on silicon substrates by vacuum arc discharge of (N_2 + Ar) gas mixtures is investigated. X-ray diffraction (XRD) results show that the average texturing coefficient of (1 1 1) orientation and the grain size of both TiN and ZrN individual layers increase with increasing the N_2 partial pressure. The Rutherford back scattering (RBS) measurements and analysis reveal that incorporation of the nitrogen in the film increases with increasing the N_2 partial pressure and both TiN and ZrN individual layers have a nitrogen over-stoichiometry for N_2 partial pressure ⩾50%. The change in the film micro-hardness is correlated to the changes in crystallographic texture, grain size, stoichiometry and the residual stress in the film as a function of the N_2 partial pressure. In particular, stoichiometry of ZrN and TiN individual is found to play the vital role in determining the multilayer hardness. The multilayer film deposited at N_2 partial pressure of 25% has the best stoichiometric ratio of both TiN and ZrN layers and the highest micro-hardness of about 32 GPa. In addition, water contact angle (WCA) measurements and analysis show a decrease in the work of adhesion on increasing the N_2 partial pressure.

  2. Partial discharge localization in power transformers based on the sequential quadratic programming-genetic algorithm adopting acoustic emission techniques

    Liu, Hua-Long; Liu, Hua-Dong

    2014-10-01

    Partial discharge (PD) in power transformers is one of the prime reasons resulting in insulation degradation and power faults. Hence, it is of great importance to study the techniques of the detection and localization of PD in theory and practice. The detection and localization of PD employing acoustic emission (AE) techniques, as a kind of non-destructive testing, plus due to the advantages of powerful capability of locating and high precision, have been paid more and more attention. The localization algorithm is the key factor to decide the localization accuracy in AE localization of PD. Many kinds of localization algorithms exist for the PD source localization adopting AE techniques including intelligent and non-intelligent algorithms. However, the existed algorithms possess some defects such as the premature convergence phenomenon, poor local optimization ability and unsuitability for the field applications. To overcome the poor local optimization ability and easily caused premature convergence phenomenon of the fundamental genetic algorithm (GA), a new kind of improved GA is proposed, namely the sequence quadratic programming-genetic algorithm (SQP-GA). For the hybrid optimization algorithm, SQP-GA, the sequence quadratic programming (SQP) algorithm which is used as a basic operator is integrated into the fundamental GA, so the local searching ability of the fundamental GA is improved effectively and the premature convergence phenomenon is overcome. Experimental results of the numerical simulations of benchmark functions show that the hybrid optimization algorithm, SQP-GA, is better than the fundamental GA in the convergence speed and optimization precision, and the proposed algorithm in this paper has outstanding optimization effect. At the same time, the presented SQP-GA in the paper is applied to solve the ultrasonic localization problem of PD in transformers, then the ultrasonic localization method of PD in transformers based on the SQP-GA is proposed. And

  3. Power source for inactivation of micro-organisms with partial high voltage discharge in a continuous process

    Creyghton, Y.; Beurskens, R.; Fiala, A.; Haan, S.W.H. de

    2002-01-01

    An electrical discharge technology is investigated as non-thermal method for inactivation of microorganisms. Potential applications include treatment of drinking water (e.g. legionella) and liquid food pasteurization (e.g. fruit juices). A strong interest exists in mild food conservation processes

  4. Structural, mechanical, electrical and wetting properties of ZrNx films deposited by Ar/N2 vacuum arc discharge: Effect of nitrogen partial pressure

    Abdallah, B.; Naddaf, M.; A-Kharroub, M.

    2013-03-01

    Non-stiochiometric zirconium nitride (ZrNx) thin films have been deposited on silicon substrates by vacuum arc discharge of (N2 + Ar) gas mixtures at different N2 partial pressure ratio. The microstructure, mechanical, electrical and wetting properties of these films are studied by means of X-ray diffraction (XRD), micro-Raman spectroscopy, Rutherford back scattering (RBS) technique, conventional micro-hardness testing, electrical resistivity, atomic force microscopy (AFM) and contact angle (CA) measurements. RBS results and analysis show that the (N/Zr) ratio in the film increases with increasing the N2 partial pressure. A ZrNx film with (Zr/N) ratio in the vicinity of stoichiometric ZrN is obtained at N2 partial pressure of 10%. XRD and Raman results indicate that all deposited films have strained cubic crystal phase of ZrN, regardless of the N2 partial pressure. On increasing the N2 partial pressure, the relative intensity of (1 1 1) orientation with respect to (2 0 0) orientation is seen to decrease. The effect of N2 partial pressure on micro-hardness and the resistivity of the deposited film is revealed and correlated to the alteration of grain size, crystallographic texture, stoichiometry and residual stress developed in the film. In particular, it is found that residual stress and nitrogen incorporation in the film play crucial role in the alteration of micro-hardness and resistivity respectively. In addition, CA and AFM results demonstrate that as N2 partial pressure increases, both the surface hydrophobicity and roughness of the deposited film increase, leading to a significant decrease in the film surface free energy (SFE).

  5. Validation of mathematical models for predicting the swirling flow and the vortex rope in a Francis turbine operated at partial discharge

    Kuibin, P.A.; Okulov, Valery; Susan-Resiga, R.F.

    2010-01-01

    recover all this information without actually computing the full three-dimensional unsteady flow in the hydraulic turbine. As a result, we provide valuable mathematical tools for assessing the turbine behaviour at off-design operating regimes in the early stages of runner design, with computational effort......The vortex rope in a hydro turbine draft tube is one the main and strong sources of pulsations in non-optimal modes of hydro turbine operation. We examine the case of a Francis turbine model operated at partial discharge, where a strong precessing vortex rope is developed in the discharge cone...... several orders of magnitude less than the current approaches of simulating the complex turbine flow....

  6. Measuring system of partial discharges with optical links and interphase for PC; Sistema de medicion de descargas parciales con enlaces opticos e interfase para PC

    Pacheco Arteaga, Maria Jojutla Olimpia

    1999-07-01

    In this work a measuring system of partial discharges based on the traditional electrical detection technique is presented, but that unlike the existing systems it uses an optical link of communication. On one hand, the optical fiber avoids that the electromagnetic interference of the area affects the measurement and on the other hand, allows to make measurements online. With a personal computer and an application program the system is controlled, besides storing and displaying graphically the acquired data. As a result of this thesis the developed system obtains the magnitude and the phase of every partial discharge occurred during a time interval fixed or selected by the user, as well as the total number of discharges. In a graphical form it presents the magnitude and the phase of each discharge, in addition to the corresponding histogram of frequencies. [Spanish] En este trabajo se presenta un sistema de medicion de descargas parciales basado en la tecnica de deteccion electrica tradicional, pero que a diferencia de los sistemas existentes utiliza un enlace de comunicacion optico. Por un lado, la fibra optica evita que la interferencia electromagnetica del medio afecte la medicion y por otro, permite hacer mediciones en linea. Con una computadora personal y un programa de aplicacion se controla el sistema, ademas de almacenar y presentar graficamente la informacion adquirida. Como resultado de esta tesis el sistema desarrollado obtiene la magnitud y la fase de cada descarga parcial ocurrida durante un intervalo de tiempo fijo o seleccionado por el usuario, asi como el numero total de descargas. En forma grafica presenta la magnitud y la fase de cada descarga, ademas del histograma de frecuencias correspondiente.

  7. Angina - discharge

    Chest pain - discharge; Stable angina - discharge; Chronic angina - discharge; Variant angina - discharge; Angina pectoris - discharge; Accelerating angina - discharge; New-onset angina - discharge; Angina-unstable - discharge; ...

  8. On-line filtering

    Verkerk, C.

    1978-01-01

    Present day electronic detectors used in high energy physics make it possible to obtain high event rates and it is likely that future experiments will face even higher data rates than at present. The complexity of the apparatus increases very rapidly with time and also the criteria for selecting desired events become more and more complex. So complex in fact that the fast trigger system cannot be designed to fully cope with it. The interesting events become thus contaminated with multitudes of uninteresting ones. To distinguish the 'good' events from the often overwhelming background of other events one has to resort to computing techniques. Normally this selection is made in the first part of the analysis of the events, analysis normally performed on a powerful scientific computer. This implies however that many uninteresting or background events have to be recorded during the experiment for subsequent analysis. A number of undesired consequences result; and these constitute a sufficient reason for trying to perform the selection at an earlier stage, in fact ideally before the events are recorded on magnetic tape. This early selection is called 'on-line filtering' and it is the topic of the present lectures. (Auth.)

  9. On line portal imaging

    Munro, Peter

    1997-01-01

    Purpose/Objective: The purpose of this presentation is to examine the various imaging devices that have been developed for portal imaging, describe some of the image registration methods that have been developed to determine geometric errors quantitatively, and discuss how portal imaging has been incorporated into clinical practice. Discussion: Verification of patient positioning has always been an important aspect of external beam radiation therapy. Over the past decade many portal imaging devices have been developed by individual investigators and most accelerator manufacturers now offer 'on-line' portal imaging systems. The commercial devices include T.V. camera-based systems, liquid ionisation chamber systems, and shortly, flat panel systems. The characteristics of these imaging systems will be discussed. In addition, other approaches such as the use of kilovoltage x-ray sources, video monitoring, and ultrasound have been proposed for improving patient positioning. Some of the advantages of these approaches will be discussed. One of the major advantages of on-line portal imaging is that many quantitative techniques have been developed to detect errors in patient positioning. The general approach is to register anatomic structures on a portal image with the same structures on a digitized simulator film. Once the anatomic structures have been registered, any discrepancies in the position of the patient can be identified. One problem is finding a common frame of reference for the simulator and portal images, since the location of the radiation field within the pixel matrix may differ for the two images. As a result, a common frame of reference has to be established before the anatomic structures in the images can be registered - generally by registering radiation field edges identified in the simulator and portal images. In addition, distortions in patient geometry or rotations out of the image plane can confound the image registration techniques. Despite the

  10. On line portal imaging

    Munro, Peter

    1996-01-01

    Purpose/Objective: The purpose of this presentation is to examine the various imaging devices that have been developed for portal imaging; describe some of the image registration methods that have been developed to determine geometric errors quantitatively; discuss some of the ways that portal imaging has been incorporated into routine clinical practice; describe quality assurance procedures for these devices, and discuss the use of portal imaging devices for dosimetry applications. Discussion: Verification of patient positioning has always been an important aspect of external beam radiation therapy. Over the past decade many portal imaging devices have been developed by individual investigators and most accelerator manufacturers now offer 'on-line' portal imaging systems. The commercial devices can be classified into three categories: T.V. camera-based systems, liquid ionisation chamber systems, and amorphous silicon systems. Many factors influence the quality of images generated by these portal imaging systems. These include factors which are unavoidable (e.g., low subject contrast), factors which depend upon the individual imaging device forming the image (e.g., dose utilisation, spatial resolution) as well as factors which depend upon the characteristics of the linear accelerator irradiating the imaging system (x-ray source size, image magnification). The characteristics of individual imaging systems, such as spatial resolution, temporal response, and quantum utilisation will be discussed. One of the major advantages of on-line portal imaging is that many quantitative techniques have been developed to detect errors in patient positioning. The general approach is to register anatomic structures on a portal image with the same structures on a digitized simulator film. Once the anatomic structures have been registered, any discrepancies in the position of the patient can be identified. However, the task is not nearly as straight-forward as it sounds. One problem

  11. Detection of partial discharges in oil transformers with the aid of acoustic emission analysis; Detektion von Teilentladungen in Oeltransformatoren durch die Schallemissionsanalyse

    Loehr, M. [Physical Acoustics BV - Deutschland, Hamburg (Germany)

    2007-07-01

    Since the early eighties, acoustic emission analysis has been used for functional testing of transformers. Partial discharges of 150 pC and above are detected reliably. Transformers with oil/paper insulation as a rule are inspected during operation by analysis of the transformer oil at regular intervals or continuously. This integral method provides no information on the operating conditions causing partial discharge and no information on their location. This information gap may be closed by acoustic emission analysis, which will provide the key information required for selective planning of preventive measures. Physical Acoustics (PAC) tested several hundreds of transformers successfully for their operating performance (see also EPRI Project I.D. No. 051481). As a result, e.g., transformers can now be operated for a longer period of time below critical load. [German] Die Schallemissionsanalyse wird seit den fruehen 80-iger Jahren letzten Jahrhunderts von Transformator-Herstellern bei der Funktionspruefung eingesetzt. Hierbei werden Teilentladungen von 150 pC und mehr zuverlaessig detektiert. Oel-papierisolierte Transformatoren werden in der Regel waehrend des Betriebs durch eine Analyse des Transformator-Oels inspeziert. Die Oelanalyse kann in regelmaessigen Abstaenden oder dauerhaft erfolgen. Als integrales Verfahren bietet diese Methode keine Information zu den Betriebsbedingungen unter den Teilentladungen auftreten und gibt auch keine Information zum Ort deren Auftretens. Diese Informationsluecke kann durch den Einsatz einer Schallemissionspruefung (AT) geschlossen werden. Mit dem Messen der Schallemission durch am Trafokessel angebrachte Sensoren kann der Ort und der Zeitpunkt von Stoerungen festgestellt werden. Mit diesen Schluesselinformationen wird es moeglich, die weiteren notwendigen Massnahmen gezielt zu planen. Physical Acoustics (PAC) hat mehrere hunderte von Transformatoren erfolgreich auf ihr Betriebsverhalten untersucht (siehe auch EPRI-Projekt I

  12. On line portal imaging

    Munro, Peter

    1995-01-01

    Purpose/Objective: The purpose of this presentation is to review the physics of imaging with high energy x-ray beams; examine the various imaging devices that have been developed for portal imaging; describe some of the image registration methods that have been developed to determine errors in patient positioning quantitatively; and discuss some of the ways that portal imaging has been incorporated into routine clinical practice. Verification of patient positioning has always been an important aspect of external beam radiation therapy. Checks of patient positioning have generally been done with film, however, film suffers from a number of drawbacks, such as poor image display and delays due to film development. Over the past decade many portal imaging devices have been developed by individual investigators and most accelerator manufacturers now offer 'on-line' portal imaging systems, which are intended to overcome the limitations of portal films. The commercial devices can be classified into three categories: T.V. camera-based systems, liquid ionisation chamber systems, and amorphous silicon systems. Many factors influence the quality of images generated by these portal imaging systems. These include factors which are unavoidable (e.g., low subject contrast), factors which depend upon the individual imaging device forming the image (e.g., dose utilisation, spatial resolution) as well as factors which depend upon the characteristics of the linear accelerator irradiating the imaging system (x-ray source size, image magnification). The fundamental factors which limit image quality and the characteristics of individual imaging systems, such as spatial resolution, temporal response, and quantum utilisation will be discussed. One of the major advantages of on-line portal imaging is that many quantitative techniques have been developed to detect errors in patient positioning. The general approach is to register anatomic structures on a portal image with the same

  13. A Novel Partial Discharge Ultra-High Frequency Signal De-Noising Method Based on a Single-Channel Blind Source Separation Algorithm

    Liangliang Wei

    2018-02-01

    Full Text Available To effectively de-noise the Gaussian white noise and periodic narrow-band interference in the background noise of partial discharge ultra-high frequency (PD UHF signals in field tests, a novel de-noising method, based on a single-channel blind source separation algorithm, is proposed. Compared with traditional methods, the proposed method can effectively de-noise the noise interference, and the distortion of the de-noising PD signal is smaller. Firstly, the PD UHF signal is time-frequency analyzed by S-transform to obtain the number of source signals. Then, the single-channel detected PD signal is converted into multi-channel signals by singular value decomposition (SVD, and background noise is separated from multi-channel PD UHF signals by the joint approximate diagonalization of eigen-matrix method. At last, the source PD signal is estimated and recovered by the l1-norm minimization method. The proposed de-noising method was applied on the simulation test and field test detected signals, and the de-noising performance of the different methods was compared. The simulation and field test results demonstrate the effectiveness and correctness of the proposed method.

  14. Analysis of the Sensitivity of K-Type Molecular Sieve-Deposited MWNTs for the Detection of SF₆ Decomposition Gases under Partial Discharge.

    Zhang, Xiaoxing; Li, Xin; Luo, Chenchen; Dong, Xingchen; Zhou, Lei

    2015-11-11

    Sulfur hexafluoride (SF6) is widely utilized in gas-insulated switchgear (GIS). However, part of SF6 decomposes into different components under partial discharge (PD) conditions. Previous research has shown that the gas responses of intrinsic and 4 Å-type molecular sieve-deposited multi-wall carbon nanotubes (MWNTs) to SOF2 and SO2F2, two important decomposition components of SF6, are not obvious. In this study, a K-type molecular sieve-deposited MWNTs sensor was developed. Its gas response characteristics and the influence of the mixture ratios of gases on the gas-sensing properties were studied. The results showed that, for sensors with gas mixture ratios of 5:1, 10:1, and 20:1, the resistance change rate increased by nearly 13.0% after SOF2 adsorption, almost 10 times that of MWNTs sensors, while the sensors' resistance change rate with a mixture ratio of 10:1 reached 17.3% after SO2F2 adsorption, nearly nine times that of intrinsic MWNT sensors. Besides, a good linear relationship was observed between concentration of decomposition components and the resistance change rate of sensors.

  15. Analysis of the Sensitivity of K-Type Molecular Sieve-Deposited MWNTs for the Detection of SF6 Decomposition Gases under Partial Discharge

    Zhang, Xiaoxing; Li, Xin; Luo, Chenchen; Dong, Xingchen; Zhou, Lei

    2015-01-01

    Sulfur hexafluoride (SF6) is widely utilized in gas-insulated switchgear (GIS). However, part of SF6 decomposes into different components under partial discharge (PD) conditions. Previous research has shown that the gas responses of intrinsic and 4 Å-type molecular sieve-deposited multi-wall carbon nanotubes (MWNTs) to SOF2 and SO2F2, two important decomposition components of SF6, are not obvious. In this study, a K-type molecular sieve-deposited MWNTs sensor was developed. Its gas response characteristics and the influence of the mixture ratios of gases on the gas-sensing properties were studied. The results showed that, for sensors with gas mixture ratios of 5:1, 10:1, and 20:1, the resistance change rate increased by nearly 13.0% after SOF2 adsorption, almost 10 times that of MWNTs sensors, while the sensors’ resistance change rate with a mixture ratio of 10:1 reached 17.3% after SO2F2 adsorption, nearly nine times that of intrinsic MWNT sensors. Besides, a good linear relationship was observed between concentration of decomposition components and the resistance change rate of sensors. PMID:26569245

  16. Efficient method for location and detection of partial discharge in transformer oil by DOA estimation of circular array of ultrasonic sensors

    Saravanakumar, N.; Sathiyasekar, K.

    2018-01-01

    The electrical insulation failures in oil transformers are mainly occurs due to the inappropriate placing of Partial Discharge (PD) sources. In order to eliminate the insulation defects and also to locate the PD sources in an appropriate location, a new approach called circular array of ultrasonic sensors (CAUS) with various analysis is proposed. At first de-noise the PD signal from the CAUS using the fast independent component analysis (Fast ICA) algorithm. Secondly, the wide band signal from CAUS is converted into narrow band signal by using the total least square algorithm (TLS). Third, parse representation of array covariance vector (SRACV) technique is utilized to separate DOA (Direction of Arrival) in three directions from PD to CAUS. Finally, the PD sources are placed in an appropriate location by using the pitch and azimuth angles of those three DOAs and the exact coordination of three planes are calculated by using the particle swarm optimization algorithm. The simulation result demonstrates the effectiveness of proposed approach in terms of PD location in transformer oil.

  17. Analysis of the Sensitivity of K-Type Molecular Sieve-Deposited MWNTs for the Detection of SF6 Decomposition Gases under Partial Discharge

    Xiaoxing Zhang

    2015-11-01

    Full Text Available Sulfur hexafluoride (SF6 is widely utilized in gas-insulated switchgear (GIS. However, part of SF6 decomposes into different components under partial discharge (PD conditions. Previous research has shown that the gas responses of intrinsic and 4 Å-type molecular sieve-deposited multi-wall carbon nanotubes (MWNTs to SOF2 and SO2F2, two important decomposition components of SF6, are not obvious. In this study, a K-type molecular sieve-deposited MWNTs sensor was developed. Its gas response characteristics and the influence of the mixture ratios of gases on the gas-sensing properties were studied. The results showed that, for sensors with gas mixture ratios of 5:1, 10:1, and 20:1, the resistance change rate increased by nearly 13.0% after SOF2 adsorption, almost 10 times that of MWNTs sensors, while the sensors’ resistance change rate with a mixture ratio of 10:1 reached 17.3% after SO2F2 adsorption, nearly nine times that of intrinsic MWNT sensors. Besides, a good linear relationship was observed between concentration of decomposition components and the resistance change rate of sensors.

  18. Online partial discharges localization system

    Primo Alberto Calva Chavarria

    2013-01-01

    Full Text Available En este artículo se presentan el diseño y construcción de un sistema no invasivo de localización de descargas parciales (PD's en línea; el cual consiste básicamente de cuatro antenas iguales tipo discono con un ancho de banda de 30 MHz a 1.2 GHZ y una frecuencia central de 615 MHz, conectada a un registrador digital de alta velocidad y cuatro canales; las señales electromagnéticas obtenidas se procesan en una computadora portátil empleando la Transformada Wavelet y la Transformada Rápida de Fourier (FFT para la discriminación del ruido electromagnético y la identificación de la fuente de origen de las descargas parciales (DPs respectivamente, adicionalmente se emplea un método esférico de localización espacial en R3. Se reportan mediciones obtenidas en un laboratorio de alta tensión y en campo.

  19. CERN Video News on line

    2003-01-01

    The latest CERN video news is on line. In this issue : an interview with the Director General and reports on the new home for the DELPHI barrel and the CERN firemen's spectacular training programme. There's also a vintage video news clip from 1954. See: www.cern.ch/video or Bulletin web page

  20. Investigation of slot discharge on a 239 MVA hydro generator stator winding

    Li, S.; Hong, W. [BC Hydro and Power Authority, Vancouver, BC (Canada)

    2009-07-01

    This paper discussed a slot discharge investigation conducted on a 239 MVA generator stator winding. The generator in which the winding was located had experienced core split distortion, stator winding phase-to-phase failures, winding failures during Hipot testing, and high partial discharge (PD) activity. The results of on-line PD testing data were evaluated. The stator winding was subjected to visual inspections, bar dissections, and failure mechanism analyses. Eleven winding bars were removed from the stator slots in order to assess groundwall insulation conditions and identify the cause of the slot discharge activity. It was determined that the root cause of the slot discharge was a loose, non-uniform bar in the slot. The vibrating bar caused the semi-conductive coating to wear out and degraded the armour tape. Results of the study demonstrated the importance of on-line PD monitoring for detecting slot PD activity. 4 refs., 3 tabs., 11 figs.

  1. On-line moisture analysis

    Cutmore, N G

    2002-01-01

    Measurement of the moisture content of iron ore has become a key issue for controlling moisture additions for dust suppression. In most cases moisture content is still determined by manual or automatic sampling of the ore stream, followed by conventional laboratory analysis by oven drying. Although this procedure enables the moisture content to be routinely monitored, it is too slow for control purposes. This has generated renewed interest in on-line techniques for the accurate and rapid measurement of moisture in iron ore on conveyors. Microwave transmission techniques have emerged over the past 40 years as the dominant technology for on-line measurement of moisture in bulk materials, including iron ores. Alternative technologies have their limitations. Infra-red analysers are used in a variety of process industries, but rely on the measurement of absorption by moisture in a very thin surface layer. Consequently such probes may be compromised by particle size effects and biased presentation of the bulk mater...

  2. On line ultrasonic integrated backscatter

    Landini, L.; Picano, E.; Mazzarisi, A.; Santarelli, F.; Benassi, A.; De Pieri, G.

    1988-01-01

    A new equipment for on-line evaluation of index based on two-dimensional integrated backscatter from ultrasonic images is described. The new equipment is fully integrated into a B-mode ultrasonic apparatus which provides a simultaneous display of conventional information together with parameters of tissue characterization. The system has been tested with a backscattering model of microbubbles in polysaccharide solution, characterized by a physiological exponential time decay. An exponential fitting to the experimental data was performed which yielded r=0.95

  3. On-line nuclear orientation

    Krane, K.S.

    1990-01-01

    This grant has as its overall goal the pursuit of on-line nuclear orientation experiments for the purpose of eliciting details of nuclear structure from the decays of neutron-deficient nuclei, such as those produced by the Holifield Heavy-Ion Research Facility at Oak Ridge and extracted by the UNISOR Isotope Separator. This paper discusses: refrigerator development; the decay of 184 Au; the decay of 191 Hg to 191 Au; the decay of 189 Pt to 189 Ir; the decays of 109,111 Pd; the decay of 172 Er; and solid angle corrections

  4. Influence of N{sub 2} partial pressure on structural and microhardness properties of TiN/ZrN multilayers deposited by Ar/N{sub 2} vacuum arc discharge

    Naddaf, M., E-mail: ascientific24@aec.org.sy [Department of Molecular Biology and Biotechnology, Atomic Energy Commission of Syria (AECS), P.O. Box 6091, Damascus (Syrian Arab Republic); Abdallah, B. [Department of Physics, Atomic Energy Commission of Syria, P.O. Box 6091, Damascus (Syrian Arab Republic); Ahmad, M. [IBA Laboratory, Department of Chemistry, Atomic Energy Commission of Syria, P.O. Box 6091, Damascus (Syrian Arab Republic); A-Kharroub, M. [Department of Physics, Atomic Energy Commission of Syria, P.O. Box 6091, Damascus (Syrian Arab Republic)

    2016-08-15

    The influence of N{sub 2} partial pressure on structural, mechanical and wetting properties of multilayered TiN/ZrN thin films deposited on silicon substrates by vacuum arc discharge of (N{sub 2} + Ar) gas mixtures is investigated. X-ray diffraction (XRD) results show that the average texturing coefficient of (1 1 1) orientation and the grain size of both TiN and ZrN individual layers increase with increasing the N{sub 2} partial pressure. The Rutherford back scattering (RBS) measurements and analysis reveal that incorporation of the nitrogen in the film increases with increasing the N{sub 2} partial pressure and both TiN and ZrN individual layers have a nitrogen over-stoichiometry for N{sub 2} partial pressure ⩾50%. The change in the film micro-hardness is correlated to the changes in crystallographic texture, grain size, stoichiometry and the residual stress in the film as a function of the N{sub 2} partial pressure. In particular, stoichiometry of ZrN and TiN individual is found to play the vital role in determining the multilayer hardness. The multilayer film deposited at N{sub 2} partial pressure of 25% has the best stoichiometric ratio of both TiN and ZrN layers and the highest micro-hardness of about 32 GPa. In addition, water contact angle (WCA) measurements and analysis show a decrease in the work of adhesion on increasing the N{sub 2} partial pressure.

  5. 基于听觉场景分析的局部放电降噪算法研究%A Study of Ambient Noise Cancellation Algorithm of Partial Discharge Using CASA

    刘闻

    2016-01-01

    In this paper,based on the partial discharge test of the high pressure chamber of the subway,the factory area and other noise environment,the paper proposes a kind of CASA algorithm,which is indepen-dent of the type of noise and the partial discharge noise reduction based on the analysis of the auditory scene.The algorithm uses two channels to col ect the signal energy,the simulation of the test instrument to extract the intensity difference of different channel signals,as a basis to identify the signal and noise.Then,the acoustic masking effect is used to cover the noise,and the enhancement of the partial discharge signal is realized.%该文针对周围为地铁,厂区等噪声环境下的高压室进行超声波局部放电测试,提出一种与噪声的类型无关、基于听觉场景分析的局部放电降噪CASA算法。该算法利用两个通道采集到的信号能量的不同,模拟局放测试仪提取不同信道信号的强度差,以此为依据来辨别信号和噪声。然后利用声学掩蔽效应,对噪声进行掩蔽,实现局部放电信号的增强。

  6. On-line moisture analysis

    Cutmore, N.G.; Mijak, D.G

    2002-01-01

    Measurement of the moisture content of iron ore has become a key issue for controlling moisture additions for dust suppression. In most cases moisture content is still determined by manual or automatic sampling of the ore stream, followed by conventional laboratory analysis by oven drying. Although this procedure enables the moisture content to be routinely monitored, it is too slow for control purposes. This has generated renewed interest in on-line techniques for the accurate and rapid measurement of moisture in iron ore on conveyors. Microwave transmission techniques have emerged over the past 40 years as the dominant technology for on-line measurement of moisture in bulk materials, including iron ores. Alternative technologies have their limitations. Infra-red analysers are used in a variety of process industries, but rely on the measurement of absorption by moisture in a very thin surface layer. Consequently such probes may be compromised by particle size effects and biased presentation of the bulk material. Nuclear-based analysers measure the total hydrogen content in the sample and do not differentiate between free and combined moisture. Such analysers may also be sensitive to material presentation and elemental composition. Very low frequency electromagnetic probes, such as capacitance or conductance probes, operate in the frequency region where the DC conductivity dominates much of the response, which is a function not only of moisture content but also of ionic composition and chemistry. These problems are overcome using microwave transmission techniques, which also have the following advantages, as a true bulk moisture analysis is obtained, because a high percentage of the bulk material is analysed; the moisture estimate is mostly insensitive to any biased presentation of moisture, for example due to stratification of bulk material with different moisture content and because no physical contact is made between the sensor and the bulk material. This is

  7. On-line data display

    Lang, Sherman Y. T.; Brooks, Martin; Gauthier, Marc; Wein, Marceli

    1993-05-01

    A data display system for embedded realtime systems has been developed for use as an operator's user interface and debugging tool. The motivation for development of the On-Line Data Display (ODD) have come from several sources. In particular the design reflects the needs of researchers developing an experimental mobile robot within our laboratory. A proliferation of specialized user interfaces revealed a need for a flexible communications and graphical data display system. At the same time the system had to be readily extensible for arbitrary graphical display formats which would be required for data visualization needs of the researchers. The system defines a communication protocol transmitting 'datagrams' between tasks executing on the realtime system and virtual devices displaying the data in a meaningful way on a graphical workstation. The communication protocol multiplexes logical channels on a single data stream. The current implementation consists of a server for the Harmony realtime operating system and an application written for the Macintosh computer. Flexibility requirements resulted in a highly modular server design, and a layered modular object- oriented design for the Macintosh part of the system. Users assign data types to specific channels at run time. Then devices are instantiated by the user and connected to channels to receive datagrams. The current suite of device types do not provide enough functionality for most users' specialized needs. Instead the system design allows the creation of new device types with modest programming effort. The protocol, design and use of the system are discussed.

  8. Pancreatitis - discharge

    Chronic pancreatitis - discharge; Pancreatitis - chronic - discharge; Pancreatic insufficiency - discharge; Acute pancreatitis - discharge ... You were in the hospital because you have pancreatitis. This is a swelling of the pancreas. You ...

  9. Heart pacemaker - discharge

    Cardiac pacemaker implantation - discharge; Artificial pacemaker - discharge; Permanent pacemaker - discharge; Internal pacemaker - discharge; Cardiac resynchronization therapy - discharge; CRT - discharge; ...

  10. Nipple Discharge

    ... any unexpected nipple discharge evaluated by a doctor. Nipple discharge in men under any circumstances could be a problem and needs further evaluation. One or both breasts may produce a nipple discharge, either spontaneously or when you squeeze your ...

  11. On-line measurement of microwave power in ECR ion source

    Zhou Changgeng; Kang Wu; Hu Yonghong; Li Yan; Lou Benchao; Zu Xiulan; Xiong Riheng; Chen Junguang; Li Xiaoyun

    2005-01-01

    It is a new technology to apply an ECR ion source to the neutron generator. Because of the structure limitation, working state of the ECR ion source could not be judged by the color of gas discharging in discharge chamber. Therefore, it was hard to estimate if the ECR ion source was working properly in the neutron generator. The method to resolve the problem was described in this paper. The microwave power was measured on-line by a directional coupler and a small microwave power meter. The ion beam current could be educed from the measured incidence microwave power, and discharge state in discharge chamber could be determined. (authors)

  12. Shawnee Mission's On-Line Cataloging System

    Ellen Wasby Miller

    1971-03-01

    Full Text Available An on-line cataloging pilot project for two elementary schools is discussed. The system components are 2740 terminals, upper-lower-case input, IBM's FASTER generalized software package, and usual cards/labels output. Reasons for choosing FASTER, software and hardware features, operating procedures, system performance and costs are detailed. Future expansion to cataloging 100,000 annual K-12 acquisitions, on-line circulation, retrospective conversion, and union book catalogs is set forth.

  13. INIS retrieval service, towards on-line

    Ebinuma, Yukio; Komatsubara, Yasutoshi

    1983-01-01

    Japan Atomic Energy Research Institute executes the retrieval service of INIS atomic energy information by batch system in cooperation with Genshiryoku Kozaikai. This service is very popular to the users in whole Japan, but the demand of on-line service has increased recently. Therefore, it was decided to begin the INIS on-line service from January, 1984, through the on-line information retrieval system of the Japan Information Center of Science and Technology. It is expected that when the operation will be started, the utilization of INIS atomic energy information in Japan will drastically increase. Also Japan Atomic Energy Research Institute has carried out the retrieval service by on-line system for those in the institute besides the batch system, accordingly, at this opportunity, the state of utilization of both systems and their distinction to use effectively, and the operation and the method of utilization of the on-line information retrieval system of JICST are explained. In the on-line system, the users are accessible to the data base themselves, and immediate information retrieval is possible, while in the batch system, the related information can be retrieved without fail, and the troublesome operation of equipment is not necessary. (Kako, I.)

  14. Effectiveness of Partition and Graph Theoretic Clustering Algorithms for Multiple Source Partial Discharge Pattern Classification Using Probabilistic Neural Network and Its Adaptive Version: A Critique Based on Experimental Studies

    S. Venkatesh

    2012-01-01

    Full Text Available Partial discharge (PD is a major cause of failure of power apparatus and hence its measurement and analysis have emerged as a vital field in assessing the condition of the insulation system. Several efforts have been undertaken by researchers to classify PD pulses utilizing artificial intelligence techniques. Recently, the focus has shifted to the identification of multiple sources of PD since it is often encountered in real-time measurements. Studies have indicated that classification of multi-source PD becomes difficult with the degree of overlap and that several techniques such as mixed Weibull functions, neural networks, and wavelet transformation have been attempted with limited success. Since digital PD acquisition systems record data for a substantial period, the database becomes large, posing considerable difficulties during classification. This research work aims firstly at analyzing aspects concerning classification capability during the discrimination of multisource PD patterns. Secondly, it attempts at extending the previous work of the authors in utilizing the novel approach of probabilistic neural network versions for classifying moderate sets of PD sources to that of large sets. The third focus is on comparing the ability of partition-based algorithms, namely, the labelled (learning vector quantization and unlabelled (K-means versions, with that of a novel hypergraph-based clustering method in providing parsimonious sets of centers during classification.

  15. Characterizing chemical systems with on-line computers and graphics

    Frazer, J.W.; Rigdon, L.P.; Brand, H.R.; Pomernacki, C.L.

    1979-01-01

    Incorporating computers and graphics on-line to chemical experiments and processes opens up new opportunities for the study and control of complex systems. Systems having many variables can be characterized even when the variable interactions are nonlinear, and the system cannot a priori be represented by numerical methods and models. That is, large sets of accurate data can be rapidly acquired, then modeling and graphic techniques can be used to obtain partial interpretation plus design of further experimentation. The experimenter can thus comparatively quickly iterate between experimentation and modeling to obtain a final solution. We have designed and characterized a versatile computer-controlled apparatus for chemical research, which incorporates on-line instrumentation and graphics. It can be used to determine the mechanism of enzyme-induced reactions or to optimize analytical methods. The apparatus can also be operated as a pilot plant to design control strategies. On-line graphics were used to display conventional plots used by biochemists and three-dimensional response-surface plots

  16. On-line monitoring for calibration reduction

    Hoffmann, M.

    2005-09-01

    On-Line Monitoring evaluates instrument channel performance by assessing its consistency with other plant indications. Elimination or reduction of unnecessary field calibrations can reduce associated labour costs, reduce personnel radiation exposure, and reduce the potential for calibration errors. On-line calibration monitoring is an important technique to implement a state-based maintenance approach and reduce unnecessary field calibrations. In this report we will look at how the concept is currently applied in the industry and what the arising needs are as it becomes more commonplace. We will also look at the PEANO System, a tool developed by the Halden Project to perform signal validation and on-line calibration monitoring. Some issues will be identified that are being addressed in the further development of these tools to better serve the future needs of the industry in this area. An outline for how to improve these points and which aspects should be taken into account is described in detail. (Author)

  17. On-line signal trend identification

    Tambouratzis, T.; Antonopoulos-Domis, M.

    2004-01-01

    An artificial neural network, based on the self-organizing map, is proposed for on-line signal trend identification. Trends are categorized at each incoming signal as steady-state, increasing and decreasing, while they are further classified according to characteristics such signal shape and rate of change. Tests with model-generated signals illustrate the ability of the self-organizing map to accurately and reliably perform on-line trend identification in terms of both detection and classification. The proposed methodology has been found robust to the presence of white noise

  18. On line routing per mobile phone

    Bieding, Thomas; Görtz, Simon; Klose, Andreas

    2009-01-01

    On-line routing is concerned with building vehicle routes in an ongoing fashion in such a way that customer requests arriving dynamically in time are efficiently and effectively served. An indispensable prerequisite for applying on-line routing methods is mobile communication technology....... Additionally it is of utmost importance that the employed communication system is suitable integrated with the firm’s enterprise application system and business processes. On basis of a case study, we describe in this paper a system that is cheap and easy to implement due to the use of simple mobile phones...

  19. On-line atomic data access

    Schultz, D.R. [Oak Ridge National Lab., TN (United States); Nash, J.K. [Lawrence Livermore National Lab., CA (United States)

    1996-04-01

    The need for atomic data is one which continues to expand in a wide variety of applications including fusion energy, astrophysics, laser- produced plasma research, and plasma processing. Modern computer database and communications technology nables this data to be placed on-line and obtained by users of the Internet. Presented here is a summary of the observations and conclusions regarding such on-line atomic data access derived from a forum held at the Tenth APS Topical Conference on Atomic Processes in Plasmas.

  20. On-line monitoring for calibration reduction

    Hoffmann, Mario; Gran, Frauke Schmitt; Thunem, Harald P-J.

    2004-04-01

    On-Line Monitoring (OLM) of a channel's calibration state evaluates instrument channel performance by assessing its consistency with other plant indications. Industry and experience at several plants has shown this overall approach to be very effective in identifying instrument channels that are exhibiting degrading or inconsistent performance characteristics. The Halden Reactor Project has developed the signal validation system PEANO, which can be used to assist with the tasks of OLM. To further enhance the PEANO System for use as a calibration reduction tool, the following two additional modules have been developed; HRP Prox, which performs pre-processing and statistical analysis of signal data, Batch Monitoring Module (BMM), which is an off-line batch monitoring and reporting suite. The purpose and functionality of the HRP Prox and BMM modules are discussed in this report, as well as the improvements made to the PEANO Server to support these new modules. The Halden Reactor Project has established a Halden On-Line Monitoring User Group (HOLMUG), devoted to the discussion and implementation of on-line monitoring techniques in power plants. It is formed by utilities, vendors, regulatory bodies and research institutes that meet regularly to discuss implementation aspects of on-line monitoring, technical specification changes, cost-benefit analysis and regulatory issues. (Author)

  1. SPIRES I: on-line search guide

    Addis, L.

    1975-06-01

    SPIRES I is the first generation of the on-line Stanford Public Information Retrieval System. Designed as a prototype system, SPIRES I was later moved to the SLAC computing facility where it has been routinely available to SLAC users in the field of high-energy physics. The scope and use of the SPIRES I system are described in this manual

  2. HOPI: on-line injection optimization program

    LeMaire, J.L.

    1977-01-01

    A method of matching the beam from the 200 MeV linac to the AGS without the necessity of making emittance measurements is presented. An on-line computer program written on the PDP10 computer performs the matching by modifying independently the horizontal and vertical emittance. Experimental results show success with this method, which can be applied to any matching section

  3. NIPPLE DISCHARGE

    T. N. Bukharova

    2008-01-01

    Full Text Available According to the data available in the literature, as high as 50% of women have benign breast tumors frequently accompanied by nip- ple discharge. Nipple discharge may be serous, bloody, purulent, and colostric. The most common causes are breast abscess, injury, drugs, prolactinoma, intraductal pappiloma, ductal ectasia, intraductal cancer (not more than 10%.

  4. Educational On-Line Gaming Propensity

    Sudzina, Frantisek; Razmerita, Liana; Kirchner, Kathrin

    2014-01-01

    Educational on-line games are promising for new generations of students who are grown up digital. Th e new generations of students are technology savvy and spend lots of time on the web and on social networks. Based on an exploratory study, this article investigates the factors that infl uence...... students’ willingness to participate in serious games for teaching/learning. Th is study investigates the relationship between students’ behavior on Facebook, Facebook games, and their attitude toward educational on-line games. Th e results of the study reveal that the early adopters of educational games...... are likely to be students, who are young, have only a few Facebook connections, who currently play Facebook game(s). Furthermore, the study emphasizes that there may be differences between students coming from various countries....

  5. Trends in on-line data processing

    Masetti, M.

    1981-01-01

    The developement of integrated circuits has been characterized by an exponential growth of gates on a single chip that will still continue in the coming years. In parallel the price per bit is dropping down with more or less the same law. As a consequence of this a few statements can be made: The present 16-bit minicomputer in a small configuration is going to be substituted by a 16-bit microcomputer, and the 16-bit microcomputer in a powerful configuration by a 32-bit midi having also a virtual memory facility. Fully programmable or microcoded powerful devices like the LASS hardware processor or MICE, will allow an efficient on-line filter. Higher computing speed can be achieved by a multiprocessor configuration which can be insensitive to hardware failures. Therefore we are moving towards an integrated on-line computing system with much higher computing power than now and the present distinction between on-line and off-line will no longer be so sharp. As more processing can be performed on-line, fast high quality feed-back can be provided for the experiment. In the years to come the trend towards more processing power, at a lower price, and assembled in the same hardware volume will continue for at least five years; at the same time the future large high-energy physics experiments at LEP will be carried out within a wide international collaboration. In this environment methods must be found for a large fraction of the work to be distributed amongst the collaborators. To accomplish this aim it is necessary to introduce common standard practices concerning both hardware and software, in such a way that the seperate parts, developed by the collaborators, will be plug-compatible. (orig.)

  6. New Trends in on-line Marketing

    Palkovič, Lukáš

    2011-01-01

    This bachelor thesis deals with new trend of internet marketing, it focuses especially on viral marketing. The theoretical part charasterizes the process of viral campaigns, furthermore deals with the components and aspects of on-line environment. Another separated chapter presents social networks, their place in viral marketing and at last but not least the viral video making process. The practical part contains different analyses of specific viral campaigns. The next and equally the last pa...

  7. On-Line Maintenance Methodology Development

    Kim, Hyo Won; Kim, Jae Ho; Jae, Moo Sung [Hanyang University, Seoul (Korea, Republic of)

    2012-05-15

    Most of domestic maintenance activities for nuclear power plants are performed while overhaul. Therefore, On-Line Maintenance (OLM) is one of the proper risks informed application techniques for diffusing maintenance burden during overhaul with safety of the plant is secured. The NUMARC 93-01 (Rev.3) presents the OLM state of the art and it provides methodology. This study adopts NUMARC 93-01 (Rev.3) and present OLM. The reference component is Emergency Diesel Generator (EDG) of Ulchin 3, 4

  8. Ileostomy - discharge

    ... dried fruits (such as raisins), mushrooms, chunky relishes, coconut, and some Chinese vegetables. Tips for when no ... ask your doctor Living with your ileostomy Low-fiber diet Small bowel resection - discharge Total colectomy or ...

  9. On-line neutron activation analyzers

    Flahaut, V.; Colmon, A.

    1999-01-01

    A neutronic analyser has been designed to determine the composition of the flow of raw materials entering a cement factory on the conveyor belt. This new system gives a reliable analysis of the whole cargo that outdates the sampling or the usual surface analysis based on fluorescence spectrometry. The accuracy is about 1%.The neutrons interact with the materials on an average depth of 25 cm and are absorbed by nuclei, these nuclei produce photons whose energy is characteristic of the chemical element itself. The composition can be deduced by measuring the number of photons emitted and their energy. The analysis is made on-line and can concern the search for about 10 compounds. In the case of cement the list of compounds is: SiO 2 , CaO, Al 2 O 3 , Fe 2 O 3 , MgO, Na 2 O, TiO 2 , S, Mn 2 O 3 , K 2 O, and H 2 O. The neutron generator involves a deuterium ion source whose deuterium ions are accelerated by means of an electrical field and impinge on a tritiated target, the nuclear reactions between deuterium and tritium produce 14 MeV neutrons. This neutron analysing technique can be adapted to any need of on-line composition determination. (A.C.)

  10. On line nuclear orientation: opportunity and challenge

    Stone, N.J.

    1985-01-01

    The development of the on-line nuclear orientation (OLNO) technique is reviewed. The present potential of the technique is discussed in the light of the attainable temperatures, the use of ion implantation and the required isotope flux. Limitations associated with spin-lattice relaxation are considered in some detail and a survey of accessible nuclei is presented. An outline comparison is given between OLNO and other methods for producing orientation of nuclei, for measuring nuclear spins and static moments and for the study of level structure and transition probabilities. The conclusion is drawn that the method in its present form has extensive potential over a wide range of nuclei. Future prospects for in-beam polarisation giving access to nuclei of shorter half lives are referred to briefly. (Auth.)

  11. An on-line diagnostic expert system

    Felkel, L.

    1987-01-01

    As experience with on-line information systems, experts systems and artificial intelligence tools grows, the authors retreat from the first euphoria that AI could help them solve the problem they were unable to solve with conventional programming. The major effort of the development time goes into building the knowledge-base. There is no such thing as a generic knowledge-base for nuclear power plants as there is, for example, for the diagnosis of a Boeing 747 aircraft. AI-methods, tools and hardware are still in a state which does not optimally lend itself to real-time application. The ability of developing prototype systems to investigate variants otherwise too costly to justify is one advantage that the authors gladly accept. Last, but no least the tools provide a flexible and adaptable user interface (desktop window systems) etc. The development of such tools in a project would be prohibitive and room for experimentation would be limited

  12. On-Line Algorithms and Reverse Mathematics

    Harris, Seth

    In this thesis, we classify the reverse-mathematical strength of sequential problems. If we are given a problem P of the form ∀X(alpha(X) → ∃Zbeta(X,Z)) then the corresponding sequential problem, SeqP, asserts the existence of infinitely many solutions to P: ∀X(∀nalpha(Xn) → ∃Z∀nbeta(X n,Zn)). P is typically provable in RCA0 if all objects involved are finite. SeqP, however, is only guaranteed to be provable in ACA0. In this thesis we exactly characterize which sequential problems are equivalent to RCA0, WKL0, or ACA0.. We say that a problem P is solvable by an on-line algorithm if P can be solved according to a two-player game, played by Alice and Bob, in which Bob has a winning strategy. Bob wins the game if Alice's sequence of plays 〈a0, ..., ak〉 and Bob's sequence of responses 〈 b0, ..., bk〉 constitute a solution to P. Formally, an on-line algorithm A is a function that inputs an admissible sequence of plays 〈a 0, b0, ..., aj〉 and outputs a new play bj for Bob. (This differs from the typical definition of "algorithm", though quite often a concrete set of instructions can be easily deduced from A.). We show that SeqP is provable in RCA0 precisely when P is solvable by an on-line algorithm. Schmerl proved this result specifically for the graph coloring problem; we generalize Schmerl's result to any problem that is on-line solvable. To prove our separation, we introduce a principle called Predictk(r) that is equivalent to -WKL0 for standard k, r.. We show that WKL0 is sufficient to prove SeqP precisely when P has a solvable closed kernel. This means that a solution exists, and each initial segment of this solution is a solution to the corresponding initial segment of the problem. (Certain bounding conditions are necessary as well.) If no such solution exists, then SeqP is equivalent to ACA0 over RCA 0 + ISigma02; RCA0 alone suffices if only sequences of standard length are considered. We use different techniques from Schmerl to prove

  13. Software for on-line experiments

    Ivanchenko, I.M.

    1981-01-01

    A review of nowadays development state of software of on-line electron experiments is presented. The principles of organization of real time systems on second generation computer base are considered. The following methods for projections search are considered: combinator methods, global methods, methods of tracking, methods of a supporting band. The following methods for determining parameter estimates based on the Lorentz equation are analysed: analytical simulation of trajectories, determination of parameters by the iterative method using the technique of calculation of recycled integrals, multidimensional statistical analysis. For the purpose of successful usage and development of software the technique of selfdocumented programs is created and the computer is applied for preparing, revising and circulation of external descriptions which as program complexes are constructed according to the hierarchical principle [ru

  14. On line protection systems for induction motors

    Colak, I.; Celik, H.; Sefa, I.; Demirbas, S.

    2005-01-01

    Protection of induction motors is very important since they are widely used in industry for many applications due to their high robustness, reliability, low cost and maintenance, high efficiency and long service life. So, protecting these motors is crucial for operations. This paper presents a combined protection approach for induction motors. To achieve this, the electrical values of the induction motor were measured with sensitivity ±1% through a data acquisition card and processed with software developed in Visual C++. An on line protection system for induction motors was achieved easily and effectively. The experimental results have shown that the induction motor was protected against the possible problems faced during the operation. The software developed for this protection provides flexible and reliable media for operators and their motors. It is expected that the motor protection achieved in this study might be faster than the classical techniques and also may be applied to larger motors easily after small modifications of the software

  15. Aprender a innovar: una experiencia on line

    Joaquín MORENO MARCHAL

    2014-11-01

    Full Text Available La creatividad y la innovación se han convertido en recursos clave en la denominada sociedad del conocimiento, que bien podría ser también llamada sociedad de la innovación. Pero innovar es una actividad compleja, que integra la aplicación de múltiples capacidades, el pensamiento divergente y convergente, la gestión de equipos humanos, la comunicación. Ahora bien, a innovar se puede, y se debe, aprender. Aprender a innovar es un reto y también una obligación para el conjunto del sistema educativo en todos sus niveles. Partiendo de estas consideraciones este trabajo expone una experiencia de aprendizaje de la creatividad y de la innovación a través de un curso totalmente on line basado en la plataforma MOODLE, en el marco del Programa de Formación Permanente de la Universidad de Cádiz. Se presenta un modelo del proceso de innovación, denominado CREALAB, de elaboración propia. Este modelo se ha utilizado como base del proceso de aprendizaje de la creatividad y de la innovación y en el diseño del curso, está organizado en torno a actividades y tiene un carácter iterativo y realimentado. Se presentan además el conjunto del diseño metodológico y los resultados obtenidos en las dos ediciones celebradas hasta el momento. El diseño del curso totalmente on line y los resultados alcanzados permiten estimar un alto potencial de aplicación, tanto a nivel personal como a nivel organizacional.

  16. Partial scram incident in FBTR

    Usha, S.; Pillai, C.P.; Muralikrishna, G.

    1989-01-01

    Evaluation of a partial scram incident occurred at the Fast Breeder Test Reactor at Kalpakkam was carried out. Based on the observations of the experiments it was ascertained that the nonpersistant order was due to superimposed noise component on the channel that was close to the threshold and had resulted in intermittent supply to electro-magnetic (EM) coils. Owing to a larger discharge time and a smaller charge time, the EM coils got progressively discharged. It was confirmed that during the incident, partial scram took place since the charging and discharging patterns of the EM coils are dissimilar and EM coils of rods A, E and F had discharged faster than others for noise component of a particular duty cycle. However, nonlatching of scram order was because of the fact that noise pulse duration was less than latching time. (author)

  17. Discharge Dialogue

    Horsbøl, Anders

    2012-01-01

    For several years, efforts have been made to strengthen collaboration between health professionals with different specializations and to improve patient transition from hospital to home (care). In the Danish health care system, these efforts have concentrated on cancer and heart diseases, whereas...... coordinator, employed at the hospital, is supposed to anticipate discharge and serve as mediator between the hospital and the municipal home care system. Drawing on methods from discourse and interaction analysis, the paper studies the practice of the discharge coordinator in two encounters between patients...... how the home context provides different resources for identification of patient needs and mutual decision making....

  18. On-line maintenance at Cofrentes NPP

    Roldan Vilches, J.; Moreno Matarranz, M. A.; Hermana Mendioroz, I.

    1998-01-01

    Cofrentes NPP has begun in 1997 activities related to At Power Preventive Maintenance over trains or systems which lead to a voluntary entry in a Limitative Condition of Operation (LCO) of the Technical Specifications. From others benefits, this program ha improved the risk management and the staff's knowledge over the functions and safety implications of the different systems, the better exploit of the resources, the co-ordination of the different organisations involved (Maintenance an Operation) and the reductions of works during shutdowns. Previous to each work, a feasibility study analyzes qualitative and quantitative (PSA), using the Risk Monitor, the implications on safety of all the tasks, assuring that the global safety of the Plant is always maintained. Tech. Spec. are analyzed in detail and also are analyzed situations of simultaneous unavailabilities of systems which could lead to a high risk situation. Two different risk controls are defined (punctual and accumulated) to assure that high risk situations will not be given. Finally, historical risk profile is analyzed to assure that the accumulated risk increase is not significant. Risk Monitor helps staff in the schedule and follow-up of the activities of On-Line Maintenance. Each one of the tasks are deeply planned and harshly analyzed and are carried out by high qualified workers. By the moment, this program is running with fully satisfaction on the Plant. (Author)

  19. SOL: INNOVACIÓN ON-LINE

    Rubén Faúndez

    2007-11-01

    Full Text Available Las aplicaciones de simulación tienden a ser cada vez más cercanas a usuarios e industrias. Sin embargo, muchas de ellas no poseen ni la capacidad ni el conocimiento como para desarrollar internamente sus modelos de simulación. Por este motivo, y como una forma de apoyar la toma de decisiones basándose en modelos de simulación, se presenta la plataforma SOL (Simulación On Line. La metodología completa de trabajo, así como la interacción entre SOL, Empresa y Asesor, son presentadas. Su base de datos, los niveles de usuarios, sus funcionalidades, y la creación automatizada de información grafica y visual, también son explicadas. En el caso de aplicación, el uso de SOL para apoyar la toma de decisiones en una operación de movimiento de material, permite a los tomadores de decisión acceder a análisis robustos basados en información extraída de los modelos de simulación. SOL, al almacenar información, funcionar vía web, generar análisis automatizados y crear visualizaciones, permite cumplir con las expectativas de los usuarios respecto a una solución integral en simulación.

  20. Simplified automatic on-line document searching

    Ebinuma, Yukio

    1983-01-01

    The author proposed searching method for users who need not-comprehensive retrieval. That is to provide flexible number of related documents for the users automatically. A group of technical terms are used as search terms to express an inquiry. Logical sums of the terms in the ascending order of frequency of the usage are prepared sequentially and automatically, and then the search formulas, qsub(m) and qsub(m-1) which meet certain threshold values are selected automatically also. Users justify precision of the search output up to 20 items retrieved by the formula qsub(m). If a user wishes more than 30% of recall ratio, the serach result should be output by qsub(m), and if he wishes less than 30% of it, it should be output by qsub(m-1). The search by this method using one year volume of INIS Database (76,600 items) and five inquiries resulted in 32% of recall ratio and 36% of precision ratio on the average in the case of qsub(m). The connecting time of a terminal was within 15 minutes per an inquiry. It showed more efficiency than that of an inexperienced searcher. The method can be applied to on-line searching system for database in which natural language only or natural language and controlled vocabulary are used. (author)

  1. On-Line Impact Load Identification

    Krzysztof Sekuła

    2013-01-01

    Full Text Available The so-called Adaptive Impact Absorption (AIA is a research area of safety engineering devoted to problems of shock absorption in various unpredictable scenarios of collisions. It makes use of smart technologies (systems equipped with sensors, controllable dissipaters and specialised tools for signal processing. Examples of engineering applications for AIA systems are protective road barriers, automotive bumpers or adaptive landing gears. One of the most challenging problems for AIA systems is on-line identification of impact loads, which is crucial for introducing the optimum real-time strategy of adaptive impact absorption. This paper presents the concept of an impactometer and develops the methodology able to perform real-time impact load identification. Considered dynamic excitation is generated by a mass M1 impacting with initial velocity V0. An analytical formulation of the problem, supported with numerical simulations and experimental verifications is presented. Two identification algorithms based on measured response of the impacted structure are proposed and discussed. Finally, a concept of the AIA device utilizing the idea of impactometer is briefly presented.

  2. Application of on-line analytical processing technique in accelerator

    Xie Dong; Li Weimin; He Duohui; Liu Gongfa; Xuan Ke

    2005-01-01

    A method of application of the on-line analytical processing technique in accelerator is described, which includes data pre-processing, the process of constructing of data warehouse and on-line analytical processing. (authors)

  3. Simultaneous Determination of Palladium and Platinum by On-line ...

    NJD

    using high performance liquid chromatography equipped with an on-line enrichment technique. Prior to ... The on-line enrichment system (Waters Corporation, USA) that was ... Using an appropriate volume (industrial plant effluents 20 mL,.

  4. Influence of visualization on consumption during on-line shopping

    Hictaler, Urška

    2013-01-01

    This diploma work studies the influence of visualization on consumption during on-line shopping. The first part of the thesis starts with key areas of visualization, consumption and on-line shopping. Visualization, areas of use, human perception and ways of product presentation in on-line shops are defined discussed first. Next, consumption, consumers and factors that influence their decisions and satisfaction are defined. The last topic in the first part of the thesis discusses on-line shopp...

  5. Angioplasty and stent - heart - discharge

    Drug-eluting stents - discharge; PCI - discharge; Percutaneous coronary intervention - discharge; Balloon angioplasty - discharge; Coronary angioplasty - discharge; Coronary artery angioplasty - discharge; Cardiac ...

  6. A Distributed System for Learning Programming On-Line

    Verdu, Elena; Regueras, Luisa M.; Verdu, Maria J.; Leal, Jose P.; de Castro, Juan P.; Queiros, Ricardo

    2012-01-01

    Several Web-based on-line judges or on-line programming trainers have been developed in order to allow students to train their programming skills. However, their pedagogical functionalities in the learning of programming have not been clearly defined. EduJudge is a project which aims to integrate the "UVA On-line Judge", an existing…

  7. Radiological discharges

    Woodliffe, J.

    1990-01-01

    Current practice of North Sea States on the discharge and disposal of liquid radioactive wastes to the North Sea are based on the declaration issued at the Second International Conference on the Protection of the North Sea, known as the London Declaration. This has three main points the first of which emphasises the application of the Best Available Technology to protect the North Sea, the second provides a framework on which future controls on radioactive discharges should be based. The third identifies two parts of the framework; to take into account the recommendations of international organizations and that any repositories of radioactive waste which are built should not pollute the North Sea. This chapter looks at how the concensus based on the London Declaration is working, gauges the progress made in the implementation of the policy goal, identifies existing and future areas for concern and proposes ways of strengthening the control of radioactive discharges. The emphasis is on the United Kingdom practice and regulations for liquid wastes, most of which comes from the Sellafield Reprocessing Plant. (author)

  8. On-line milk spectrometry: analysis of bovine milk composition

    Spitzer, Kyle; Kuennemeyer, Rainer; Woolford, Murray; Claycomb, Rod

    2005-04-01

    We present partial least squares (PLS) regressions to predict the composition of raw, unhomogenised milk using visible to near infrared spectroscopy. A total of 370 milk samples from individual quarters were collected and analysed on-line by two low cost spectrometers in the wavelength ranges 380-1100 nm and 900-1700 nm. Samples were collected from 22 Friesian, 17 Jersey, 2 Ayrshire and 3 Friesian-Jersey crossbred cows over a period of 7 consecutive days. Transmission spectra were recorded in an inline flowcell through a 0.5 mm thick milk sample. PLS models, where wavelength selection was performed using iterative PLS, were developed for fat, protein, lactose, and somatic cell content. The root mean square error of prediction (and correlation coefficient) for the nir and visible spectrometers respectively were 0.70%(0.93) and 0.91%(0.91) for fat, 0.65%(0.5) and 0.47%(0.79) for protein, 0.36%(0.49) and 0.45%(0.43) for lactose, and 0.50(0.54) and 0.48(0.51) for log10 somatic cells.

  9. Hysterectomy - vaginal - discharge

    Vaginal hysterectomy - discharge; Laparoscopically assisted vaginal hysterectomy - discharge; LAVH - discharge ... you were in the hospital, you had a vaginal hysterectomy. Your surgeon made a cut in your ...

  10. Robust on-line monitoring of biogas processes; Robusta maettekniker on-line foer optimerad biogasproduktion

    Nordberg, Aake; Hansson, Mikael; Kanerot, Mija; Krozer, Anatol; Loefving, Bjoern; Sahlin, Eskil

    2010-03-15

    Although demand for biomethane in Sweden is higher than ever, many Swedish codigestion plants are presently operated below their designed capacity. Efforts must be taken to increase the loading rate and guarantee stable operation and high availability of the plants. There are currently no commercial systems for on-line monitoring, and due to the characteristics of the material, including corrosion and tearing, robust applications have to be developed. The objective of this project was to identify and study different monitoring technologies with potential for on-line monitoring of both substrate mixtures and anaerobic digester content. Based on the prerequisites and demands at Boraas Energi och Miljoe AB's (BEMAB, the municipal energy and waste utility in the city of Boraas, Sweden) biogas plant, the extent of the problems, measurement variables and possible ways of managing these issues have been identified and prioritized. The substrate mixtures in question have a high viscosity and are inhomogeneous with variation in composition, which calls for further homogenization, dilution and filtration to achieve high precision in the necessary analyses. Studies of using different mixers and mills showed that the particle size (800 mum) needed for on-line COD measurement could not be achieved. The problem of homogenization can be avoided if indirect measurement methods are used. Laboratory tests with NIR (near-infra red spectroscopy) showed that VS can be predicted (R2=0,78) in the interval of 2-9% VS. Furthermore, impedance can give a measurement of soluble components. However, impedance is not sensitive enough to give a good measurement of total TS. Microwave technology was installed at the production plant and showed a faster response to changes in TS than the existing TS-sensor. However, due to technical problems, the evaluation only could be done during a limited period of ten days. BEMAB will continue the measurements and evaluation of the instrument. The

  11. Partial Cancellation

    First page Back Continue Last page Overview Graphics. Partial Cancellation. Full Cancellation is desirable. But complexity requirements are enormous. 4000 tones, 100 Users billions of flops !!! Main Idea: Challenge: To determine which cross-talker to cancel on what “tone” for a given victim. Constraint: Total complexity is ...

  12. Lung surgery - discharge

    ... Lung biopsy - discharge; Thoracoscopy - discharge; Video-assisted thoracoscopic surgery - discharge; VATS - discharge ... milk) for 2 weeks after video-assisted thoracoscopic surgery and 6 to 8 weeks after open surgery. ...

  13. Pediatric heart surgery - discharge

    ... discharge; Heart valve surgery - children - discharge; Heart surgery - pediatric - discharge; Heart transplant - pediatric - discharge ... Geme JW, Schor NF, eds. Nelson Textbook of Pediatrics . 20th ed. Philadelphia, PA: Elsevier; 2016:chap 434. ...

  14. DOE-EPRI On-Line Monitoring Implementation Guidelines

    E. Davis, R. Bickford

    2003-01-01

    Industry and EPRI experience at several plants has shown on-line monitoring to be very effective in identifying out-of-calibration instrument channels or indications of equipment-degradation problems. The EPRI implementation project for on-line monitoring has demonstrated the feasibility of on-line monitoring at several participating nuclear plants. The results have been very encouraging, and substantial progress is anticipated in the coming years

  15. Partial processing

    1978-11-01

    This discussion paper considers the possibility of applying to the recycle of plutonium in thermal reactors a particular method of partial processing based on the PUREX process but named CIVEX to emphasise the differences. The CIVEX process is based primarily on the retention of short-lived fission products. The paper suggests: (1) the recycle of fission products with uranium and plutonium in thermal reactor fuel would be technically feasible; (2) it would, however, take ten years or more to develop the CIVEX process to the point where it could be launched on a commercial scale; (3) since the majority of spent fuel to be reprocessed this century will have been in storage for ten years or more, the recycling of short-lived fission products with the U-Pu would not provide an effective means of making refabrication fuel ''inaccessible'' because the radioactivity associated with the fission products would have decayed. There would therefore be no advantage in partial processing

  16. Partial gigantism

    М.М. Karimova

    2017-05-01

    Full Text Available A girl with partial gigantism (the increased I and II fingers of the left foot is being examined. This condition is a rare and unresolved problem, as the definite reason of its development is not determined. Wait-and-see strategy is recommended, as well as correcting operations after closing of growth zones, and forming of data pool for generalization and development of schemes of drug and radial therapeutic methods.

  17. Development of a Probabilistic Technique for On-line Parameter and State Estimation in Non-linear Dynamic Systems

    Tunc Aldemir; Miller, Don W.; Hajek, Brian K.; Peng Wang

    2002-01-01

    The DSD (Dynamic System Doctor) is a system-independent, interactive software under development for on-line state/parameter estimation in dynamic systems (1), partially supported through a Nuclear Engineering Education (NEER) grant during 1998-2001. This paper summarizes the recent accomplishments in improving the user-friendliness and computational capability of DSD

  18. Algorithms for the on-line travelling salesman

    Ausiello, G.; Feuerstein, E.; Leonardi, S.; Stougie, L.; Talamo, M.

    1999-01-01

    In this paper the problem of efficiently serving a sequence of requests presented in an on-line fashion located at points of a metric space is considered. We call this problem the On-Line Travelling Salesman Problem (OLTSP). It has a variety of relevant applications in logistics and robotics. We

  19. An algorithm for on-line price discrimination

    D.D.B. van Bragt; D.J.A. Somefun (Koye); E. Kutschinski; J.A. La Poutré (Han)

    2002-01-01

    textabstractThe combination of on-line dynamic pricing with price discrimination can be very beneficial for firms operating on the Internet. We therefore develop an on-line dynamic pricing algorithm that can adjust the price schedule for a good or service on behalf of a firm. This algorithm (a

  20. On-Line Voltage Stability Assessment based on PMU Measurements

    Garcia-Valle, Rodrigo; P. Da Silva, Luiz C.; Nielsen, Arne Hejde

    2009-01-01

    This paper presents a method for on-line monitoring of risk voltage collapse based on synchronised phasor measurement. As there is no room for intensive computation and analysis in real-time, the method is based on the combination of off-line computation and on-line monitoring, which are correlat...

  1. From Off-line to On-line Handwriting Recognition

    Lallican, P.; Viard-Gaudin, C.; Knerr, S.

    2004-01-01

    On-line handwriting includes more information on time order of the writing signal and on the dynamics of the writing process than off-line handwriting. Therefore, on-line recognition systems achieve higher recognition rates. This can be concluded from results reported in the literature, and has been

  2. On-line Learning of Prototypes and Principal Components

    Biehl, M.; Freking, A.; Hölzer, M.; Reents, G.; Schlösser, E.; Saad, David

    1998-01-01

    We review our recent investigation of on-line unsupervised learning from high-dimensional structured data. First, on-line competitive learning is studied as a method for the identification of prototype vectors from overlapping clusters of examples. Specifically, we analyse the dynamics of the

  3. On-line and bulk analysis for the resource industries

    Lim, C.S.; Sowerby, B.D.; Tickner, J.R.; Madsen, I.C.

    2001-01-01

    Nuclear techniques are the basis of many CSIRO on-line and bulk analysis systems that are now widely used in the mineral and energy industries. The continuous analysis and rapid response of these systems have led to improved control of mining, processing and blending operations. This paper reviews recent developments in neutron, gamma-ray and X-ray techniques for on-line and bulk analysis by CSIRO Minerals including neutron techniques for the on-conveyor belt determination of the composition of cement raw meal, the on-line analysis of composition in pyrometallurgical applications, the on-conveyor belt determination of ash in coal, and the rapid and accurate determination of gold in bulk laboratory samples. The paper also discusses a new gamma-ray technique for the on-line determination of ash in coal and the application of X-ray diffraction techniques for the on-line determination of mineralogy in the cement industry

  4. Physics of partially ionized plasmas

    Krishan, Vinod

    2016-01-01

    Plasma is one of the four fundamental states of matter; the other three being solid, liquid and gas. Several components, such as molecular clouds, diffuse interstellar gas, the solar atmosphere, the Earth's ionosphere and laboratory plasmas, including fusion plasmas, constitute the partially ionized plasmas. This book discusses different aspects of partially ionized plasmas including multi-fluid description, equilibrium and types of waves. The discussion goes on to cover the reionization phase of the universe, along with a brief description of high discharge plasmas, tokomak plasmas and laser plasmas. Various elastic and inelastic collisions amongst the three particle species are also presented. In addition, the author demonstrates the novelty of partially ionized plasmas using many examples; for instance, in partially ionized plasma the magnetic induction is subjected to the ambipolar diffusion and the Hall effect, as well as the usual resistive dissipation. Also included is an observation of kinematic dynam...

  5. Multi-Stratum Networks: toward a unified model of on-line identities

    Rossi, Luca; Magnani, Matteo

    2012-01-01

    One of the reasons behind the success of Social Network Analysis is its simple and general graph model made of nodes (representing individuals) and ties. However, when we focus on our daily on-line experience we must confront a more complex scenario: people inhabitate several on-line spaces...... interacting to several communities active on various technological infrastructures like Twitter, Facebook, YouTube or FourSquare and with distinct social objectives. This constitutes a complex network of interconnected networks where users' identities are spread and where information propagates navigating...... through different communities and social platforms. In this article we introduce a model for this layered scenario that we call multi-stratum network. Through a theoretical discussion and the analysis of real-world data we show how not only focusing on a single network may provide a very partial...

  6. Photogenic partial seizures.

    Hennessy, M J; Binnie, C D

    2000-01-01

    To establish the incidence and symptoms of partial seizures in a cohort of patients investigated on account of known sensitivity to intermittent photic stimulation and/or precipitation of seizures by environmental visual stimuli such as television (TV) screens or computer monitors. We report 43 consecutive patients with epilepsy, who had exhibited a significant EEG photoparoxysmal response or who had seizures precipitated by environmental visual stimuli and underwent detailed assessment of their photosensitivity in the EEG laboratory, during which all were questioned concerning their ictal symptoms. All patients were considered on clinical grounds to have an idiopathic epilepsy syndrome. Twenty-eight (65%) patients reported visually precipitated attacks occurring initially with maintained consciousness, in some instances evolving to a period of confusion or to a secondarily generalized seizure. Visual symptoms were most commonly reported and included positive symptoms such as coloured circles or spots, but also blindness and subjective symptoms such as "eyes going funny." Other symptoms described included nonspecific cephalic sensations, deja-vu, auditory hallucinations, nausea, and vomiting. No patient reported any clear spontaneous partial seizures, and there were no grounds for supposing that any had partial epilepsy excepting the ictal phenomenology of some or all of the visually induced attacks. These findings provide clinical support for the physiological studies that indicate that the trigger mechanism for human photosensitivity involves binocularly innervated cells located in the visual cortex. Thus the visual cortex is the seat of the primary epileptogenic process, and the photically triggered discharges and seizures may be regarded as partial with secondary generalization.

  7. Understanding on-line community: the affordances of virtual space

    Karen Ruhleder

    2002-01-01

    Full Text Available Increasing numbers of on-line venues for learning are emerging as virtual communities become more accessible and commonplace. This paper looks at one particular virtual community, an on-line degree programme at the University of Illinois, Urbana-Champaign, which offers an M.S. in Library and Information Science (called LEEP. It draws on a framework presented by Mynatt, et al. (1998, which provides a lens for talking about on-line community as a set of affordances. This framework is applied to illustrate the interactions, artefacts, and expectations that shape this community.

  8. An Approach to On-line Risk Assessment in NPP

    Simic, Z.; Mikulicic, V.; O'Brien, J.

    1996-01-01

    Probabilistic Risk Assessment (PRA) can provide safety status information for a plant during different configurations; additional effort is needed to do this in real time for on-line operation. This paper describes an approach to use PRA to achieve these goals. A Risk Assessment On-Line (RAOL) application was developed to monitor maintenance (on-line and planned) activities. RAOL is based on the results from a full-scope PRA, engineering/operational judgment and incorporates a user friendly program interface approach. Results from RAOL can be used by planners or operations to effectively manage the level of risk by controlling the actual plant configuration. (author)

  9. On-line spectroscopy with thermal atomic beams

    Thibault, C.; Guimbal, P.; Klapisch, R.; Saint Simon, M. de; Serre, J.M.; Touchard, F.; Duong, H.T.; Jacquinot, P.; Juncar, P.

    1981-01-01

    On-line high resolution laser spectroscopy experiments have been performed in which the light from a cw tunable dye laser interacts at right angles with a thermal atomic beam. sup(76-98)Rb, sup(118-145)Cs and sup(208-213)Fr have been studied using the ionic beam delivered by the ISOLDE on-line mass separator at CERN while sup(20-31)Na and sup(38-47)K have been studied by setting the apparaturs directly on-line with the PS 20 GeV proton beam. The principle of the method is briefly explained and some results concerning nuclear structure are given. (orig.)

  10. Comparison of On-Line Maintenance Support Tools

    Simic, Z.; Follen, S. M.; Mikulicic, V.

    1998-01-01

    Modeling approach to on-line risk monitoring is today in a rapid developing phase. For that reason number of different solutions are available. This paper will attempt to present existing approaches to address on-line risk modeling problem Starting with description of on-line risk monitoring issues in general, then following by presentation of existing software tools (EPRI's Safety Monitor, Equipment Out of Service Monitor, and ORAM-SENTINEL) the current state of the art in this area will be demonstrated. Finally, conclusions and ideas will be outlined. (author)

  11. Tennis elbow surgery - discharge

    ... epicondylitis surgery - discharge; Lateral tendinosis surgery - discharge; Lateral tennis elbow surgery - discharge ... long as you are told. This helps ensure tennis elbow will not return. You may be prescribed a ...

  12. Ankle replacement - discharge

    ... total - discharge; Total ankle arthroplasty - discharge; Endoprosthetic ankle replacement - discharge; Osteoarthritis - ankle ... You had an ankle replacement. Your surgeon removed and reshaped ... an artificial ankle joint. You received pain medicine and were ...

  13. Hip fracture - discharge

    ... neck fracture repair - discharge; Trochanteric fracture repair - discharge; Hip pinning surgery - discharge ... in the hospital for surgery to repair a hip fracture, a break in the upper part of ...

  14. Asthma - child - discharge

    Pediatric asthma - discharge; Wheezing - discharge; Reactive airway disease - discharge ... Your child has asthma , which causes the airways of the lungs to swell and narrow. In the hospital, the doctors and nurses helped ...

  15. Determination of antibiotic compounds in water by on-line SPE-LC/MSD.

    Choi, Keun-Joo; Kim, Sang-Goo; Kim, Chang-won; Kim, Seung-Hyun

    2007-01-01

    This study attempts to provide an improved approach for the analysis of antibiotics, which normally exist at low concentration in complex matrices such as receiving streams of wastewater treatment plant discharge. The analytical method developed in this study combines an existing pretreatment technique of solid-phase extraction (SPE) with liquid chromatography mass spectrometry (LC/MSD) through on-line connection. The on-line connection suppressed the target loss by keeping the cartridge from drying, which resulted in improvement of the recovery and saving of the analytical time. For the on-line solid-phase extraction of 10 ml water samples, recoveries were between 74.3% and 116.5% and average LOQ was 0.11 microg l(-1) for the sulfonamide antibiotics (SA) and 0.09 microg l(-1) for the tetracycline antibiotics (TA). Application of the developed method for the analysis of fourteen antibiotics revealed that several antibiotics were detected at concentrations above the LOQ in ARW. Treated and untreated sewage and agricultural wastewater were mostly responsible for the antibiotics contamination of the river. Antibiotics were detected at much higher concentrations in the agricultural wastewater sample than in the sewage sample, implying substantial use of antibiotics in the agricultural industry. Wastewater treatment was generally effective in separation of the antibiotics tested in this study. The extent of the treatment depended on the type of antibiotics. Hydrophobic antibiotics were more effectively separated from the solution than hydrophilic antibiotics.

  16. On-line methanol sensor system development for recombinant ...

    On-line methanol sensor system development for recombinant human serum ... of the methanol sensor system was done in a medium environment with yeast cells ... induction at a low temperature and a pH where protease does not function.

  17. On-line control systems in power plants

    Freymeyer, P.

    1981-01-01

    This report is a review of on-line control systems as a complex system connected with all problems like, development, planning, degree of automation, economics, service, quality and documentation. (orig.) [de

  18. Why do People Stop Playing On-Line Games?

    Sudzina, Frantisek; Razmerita, Liana

    2012-01-01

    The recent initial public offering of shares of Zynga, probably the most important on-line game provider, drew interest of potential investors but also of general public to their business model. What the most interested people learned so far is that if Zynga had not changed their accounting...... practice, they would be in red numbers for several months already. This is most likely caused by people stopping to play their games. This paper provides an estimate of what proportion of people, who played on-line games, already stopped playing them. Additionally, it analyzed the reasons why people...... stopped playing on-line games. It also compares Facebook and other on-line games....

  19. Influence of expander components on the processes at the negative plates of lead-acid cells on high-rate partial-state-of-charge cycling. Part II. Effect of carbon additives on the processes of charge and discharge of negative plates

    Pavlov, D.; Nikolov, P.; Rogachev, T. [Institute of Electrochemistry and Energy Systems, Bulgarian Academy of Sciences, Acad. Georgi Bonchev Street, bl. 10, Sofia 1113 (Bulgaria)

    2010-07-15

    Lead-acid batteries operated in the high-rate partial-state-of-charge (HRPSoC) duty rapidly lose capacity on cycling, because of sulfation of the negative plates. As the battery operates from a partially discharged state, the small PbSO{sub 4} crystals dissolve and precipitate onto the bigger crystals. The latter have low solubility and hence PbSO{sub 4} accumulates progressively in the negative plates causing capacity loss. In order to suppress this process, the rate of the charge process should be increased. In a previous publication of ours we have established that reduction of Pb{sup 2+} ions to Pb may proceed on the surface of both Pb and carbon black particles. Hence, the reversibility of the charge-discharge processes improves, which leads to improved cycle life performance of the batteries in the HRPSoC mode. However, not all carbon forms accelerate the charge processes. The present paper discusses the electrochemical properties of two groups of carbon blacks: Printex and active carbons. The influence of Vaniseprse A and BaSO{sub 4} (the other two components of the expander added to the negative plates) on the reversibility of the charge-discharge processes on the negative plates is also considered. It has been established that lignosulfonates are adsorbed onto the lead surface and retard charging of the battery. BaSO{sub 4} has the opposite effect, which improves the reversibility of the processes on cycling and hence prolongs battery life in the HRPSoC duty. It has been established that the cycle life of lead-acid cells depends on the type of carbon black or active carbon added to the negative plates. When the carbon particles are of nano-sizes (<180 nm), the HRPSoC cycle life is between 10,000 and 20,000 cycles. Lignosulfonates suppress this beneficial effect of carbon black and activated carbon additives to about 10,000 cycles. Cells with active carbons have the longest cycle life when they contain also BaSO{sub 4} but no lignosulfonate. A summary of

  20. Prostate brachytherapy - discharge

    Implant therapy - prostate cancer - discharge; Radioactive seed placement - discharge ... You had a procedure called brachytherapy to treat prostate cancer. Your treatment lasted 30 minutes or more, ...

  1. The Daresbury On-Line Isotope Separator (DOLIS)

    Grant, I.S.; Eastham, D.A.; Groves, J.; Tolfree, D.W.L.; Walker, P.M.; Green, V.R.; Rikovska, J.; Stone, N.J.; Hamilton, W.D.

    1987-01-01

    The isotope separator DOLIS, which is on-line to the Daresbury Laboratory's 20-MV tandem accelerator, is used to measure nuclear moments and decay schemes. Separated beams may be collected on a tape and transported to a counting station, implanted directly into a host lattice at on-line temperatures down to less than 10 mK, or allowed to interact with a collinear laser beam. The present status of DOLIS and its ancillary equipment is described

  2. The Daresbury on-line isotope separator (DOLIS)

    Grant, I.S.; Eastham, D.A.; Groves, J.; Tolfree, D.W.L.; Walker, P.M.; Green, V.R.; Rikovska, J.; Stone, N.J.; Hamilton, W.D.

    1987-01-01

    The isotope separator DOLIS, which is on-line to the Daresbury Laboratory's 20-MV tandem accelerator, is used to measure nuclear moments and decay schemes. Separated beams may be collected on a tape and transported to a counting station, implanted directly into a host lattice at on-line temperatures down to less than 10 mK, or allowed to interact with a collinear laser beam. The present status of DOLIS and its ancillary equipment is described. (orig.)

  3. Considerations in applying on-line IC techniques to BWR's

    Kaleda, R.J.

    1992-01-01

    Ion-Chromatography (IC) has moved from its traditional role as a laboratory analytical tool to a real time, dynamic, on-line measurement device to follow ppb and sub-ppb concentrations of deleterious impurities in nuclear power plants. Electric Power Research Institute (EPRI), individual utilities, and industry all have played significant roles in effecting the transition. This paper highlights considerations and the evolution in current on-line Ion Chromatography systems. The first applications of on-line techniques were demonstrated by General Electric (GE) under EPRI sponsorship at Rancho Seco (1980), Calvert Cliffs, and McGuire nuclear units. The primary use was for diagnostic purposes. Today the on-line IC applications have been expanded to include process control and routine plant monitoring. Current on-line IC's are innovative in design, promote operational simplicity, are modular for simplified maintenance and repair, and use field-proven components which enhance reliability. Conductivity detection with electronic or chemical suppression and spectrometric detection techniques are intermixed in applications. Remote multi-point sample systems have addressed memory effects. Early applications measured ionic species in the part per billion range. Today reliable part per trillion measurements are common for on-line systems. Current systems are meeting the challenge of EPRI guideline requirements. Today's on-line IC's, with programmed sampling systems, monitor fluid streams throughout a power plant, supplying data that can be trended, stored and retrieved easily. The on-line IC has come of age. Many technical challenges were overcome to achieve today's IC

  4. On-line mixture-based alternative to logistic regression

    Nagy, Ivan; Suzdaleva, Evgenia

    2016-01-01

    Roč. 26, č. 5 (2016), s. 417-437 ISSN 1210-0552 R&D Projects: GA ČR GA15-03564S Institutional support: RVO:67985556 Keywords : on-line modeling * on-line logistic regression * recursive mixture estimation * data dependent pointer Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 0.394, year: 2016 http://library.utia.cas.cz/separaty/2016/ZS/suzdaleva-0464463.pdf

  5. On-line maintenance PSA support at NPP Krsko

    Prosen, R.; Vrbanic, I.; Kastelan, M.

    2000-01-01

    In 1997 Krsko NPP initiated the on-line maintenance (OLM) practice. On-line maintenance constitutes of corrective activities, preventive activities, surveillance activities, tests and inspections, as well as calibrations and modifications, taking place during the normal power operations. The on-line maintenance is a multidisciplinary process consisting of activity specification, planning, and preparation and performing of the OLM activity of interest. The primary role of the PSA group is to assess from the r isk perspective , using the plant-specific NEK PSA model, system unavailability and the impact to the plant operational risk. The intent is to support planning of the on-line maintenance activities from the risk perspective. The risk evaluation of the OLM activities is based on the probability of core damage evaluation for the defined discrete plant configuration states, determined by the OLM activities. Within this application, the optimized, plant-specific PSA model is used on Risk Spectrum platform. To perform the risk assessment of the on-line maintenance activities, first the systems to be affected are defined based on the planned OLM activities. The next important step is the assessment of the planned work schedule. To define the final schedule, the co-ordination and optimizing the planned OLM activities needs activation of all participating departments, supported also from PSA group. The P3 (i.e. Primavera) planning tool system windows are defined for different systems and groups of systems, and the activities are sorted in particular weeks according to these windows. (author)

  6. OLDASS: On-line data acquisition system at SF cyclotron

    Omata, Kazuo; Yasue, Masaharu; Hamagaki, Hideki

    1982-01-01

    The on-line data acquisition system in the Institute for Nuclear Study, the University of Tokyo, is composed of 2 systems of Fujitsu mini-computer PFU-400 for data processing at the high energy synchrotron and one system of that computer for low energy cyclotron as terminals, the host computer being M 180 II AD of the same company. This system has been developed to have the features of being the on-line system capable of following the improvement of host computer performance, being capable of developing the on-line programmes of other experimenting groups in parallel with batch jobs or the operation of the on-line system, and capable of developing programmes using FORTRAN. The result of about 220 KB/s was obtained for the data transfer rate between the programmes of the host computer and terminals, and this fulfilled the aimed performance. The terminal system on the low energy side is provided with an ADC interface and a display interface specified particularly in addition to the miniature computer PFU400 and standard I/O devices of the manufacture. The accumulating type graphic display of the I/O devices can be switched to be connected to the host computer, and immediately displays the results transferred to the host computer and analyzed. Hard copy is also available. The above hardware and software are explained. The on-line system insures 80 K bytes of the total memory of 224 K bytes for data area. (Wakatsuki, Y.)

  7. Sport Management Taught On-Line: A Discussion

    William F. Stier Jr

    2009-01-01

    Full Text Available An introduction to the world of on-line courses (distance education/learning is presented. In addition, the world of on-line learning, as it pertains to sport management, is examined within the framework of (a pedagogy, (b finances,(c assessment, and (d choosing to transition from the traditional classroom to on-line learning. Pertinent points relative to each of the four categories are presented from the literature. In an effort to stimulate thought and discussion to the subject of on-line learning for sport management programs/courses the authors provide their reactions to the literature points by presenting their comments/reactions from a sport management perspective. Sport management professors and administrators are encouraged to critically examine the feasibility of such on-line courses (distance education/learning within their own curricula while maintaining an appropriate framework revolving around sound theoretical instructional strategies, methods as well as appropriate use of instructional tools, including but not limited to, computersand the WWW.

  8. Initiating Events Modeling for On-Line Risk Monitoring Application

    Simic, Z.; Mikulicic, V.

    1998-01-01

    In order to make on-line risk monitoring application of Probabilistic Risk Assessment more complete and realistic, a special attention need to be dedicated to initiating events modeling. Two different issues are of special importance: one is how to model initiating events frequency according to current plant configuration (equipment alignment and out of service status) and operating condition (weather and various activities), and the second is how to preserve dependencies between initiating events model and rest of PRA model. First, the paper will discuss how initiating events can be treated in on-line risk monitoring application. Second, practical example of initiating events modeling in EPRI's Equipment Out of Service on-line monitoring tool will be presented. Gains from application and possible improvements will be discussed in conclusion. (author)

  9. Strengthening weak ties through on-line gaming

    Sudzina, Frantisek; Razmerita, Liana Virginia; Kirchner, Kathrin

    On-line gaming became widespread in the last couple of years. The aim of the research presented in the paper is to figure out to what extent does game playing helps to strengthen weak ties and what additional factors influence this process. The approach is rather exploratory – some factors...... are grounded in theory, some are new. These factors are age, gender, place of origin, number of their Facebook connections (friends in Facebook terminology), the amount of time they are on Facebook, the amount of time they keep the Facebook site open, the amount of time they play on-line games, and the reasons...... for starting to play on-line games. Regarding the latter, we chose to focus only on escapist reasons....

  10. Thermographic Sensing For On-Line Industrial Control

    Holmsten, Dag

    1986-10-01

    It is today's emergence of thermoelectrically cooled, highly accurate infrared linescanners and imaging systems that has definitely made on-line Infraread Thermography (IRT) possible. Specifically designed for continuous use, these scanners are equipped with dedicated software capable of monitoring and controlling highly complex thermodynamic situations. This paper will outline some possible implications of using IRT on-line by describing some uses of this technology in the steel-making (hot rolling) and automotive industries (machine-vision). A warning is also expressed that IRT technology not originally designed for automated applications e.g. high resolution, imaging systems, should not be directly applied to an on-line measurement situation without having its measurement resolution, accuracy and especially its repeatability, reliably proven. Some suitable testing procedures are briefly outlined at the end of the paper.

  11. An on-line monitoring system for navigation equipment

    Wang, Bo; Yang, Ping; Liu, Jing; Yang, Zhengbo; Liang, Fei

    2017-10-01

    Civil air navigation equipment is the most important infrastructure of Civil Aviation, which is closely related to flight safety. In addition to regular flight inspection, navigation equipment's patrol measuring, maintenance measuring, running measuring under special weather conditions are the important means of ensuring aviation flight safety. According to the safety maintenance requirements of Civil Aviation Air Traffic Control navigation equipment, this paper developed one on-line monitoring system with independent intellectual property rights for navigation equipment, the system breakthroughs the key technologies of measuring navigation equipment on-line including Instrument Landing System (ILS) and VHF Omni-directional Range (VOR), which also meets the requirements of navigation equipment ground measurement set by the ICAO DOC 8071, it provides technical means of the ground on-line measurement for navigation equipment, improves the safety of navigation equipment operation, and reduces the impact of measuring navigation equipment on airport operation.

  12. On-line calculation of 3-D power distribution

    Park, Y. H.; In, W. K.; Park, J. R.; Lee, C. C.; Auh, G. S.

    1996-01-01

    The 3-D power distribution synthesis scheme was implemented in Totally Integrated Core Operation Monitoring System (TICOMS), which is under development as the next generation core monitoring system. The on-line 3-D core power distribution obtained from the measured fixed incore detector readings is used to construct the hot pin power as well as the core average axial power distribution. The core average axial power distribution and the hot pin power of TICOMS were compared with those of the current digital on-line core monitoring system, COLSS, which construct the core average axial power distribution and the pseudo hot pin power. The comparison shows that TICOMS results in the slightly more accurate core average axial power distribution and the less conservative hot pin power. Therefore, these results increased the core operating margins. In addition, the on-line 3-D power distribution is expected to be very useful for the core operation in the future

  13. Approaches for on-line coupling of extraction and chromatography

    Hyoetylaeinen, Tuulia; Riekkola, Marja-Liisa [Laboratory of Analytical Chemistry, Department of Chemistry, University of Helsinki, P.O. Box 55, 00014, Helsinki (Finland)

    2004-04-01

    This review provides an overview of the approaches available in order to perform on-line coupling of various extraction techniques with liquid and gas chromatography, for the analysis of semivolatile and nonvolatile analytes in liquid and solid samples. The main focus is on the instrumental set-up of these techniques. Selected real applications are described by way of illustration. The extraction methods suitable for on-line coupling covered in this review are: liquid-liquid extraction, solid-phase extraction, membrane-based techniques, pressurised liquid extraction, supercritical fluid extraction, and microwave- and sonication-assisted extractions. The following systems are not covered in this review: on-line coupled solid-phase extraction-liquid chromatography, purge-and-trap-GC, and membrane extraction with a sorbent interface-GC. (orig.)

  14. UNISOR on-line nuclear orientation facility (UNISOR/NOF)

    Girit, I.C.; Alton, G.D.; Bingham, C.R.; Carter, H.K.; Simpson, M.L.; Cole, J.D.; Croft, W.L.; Hamilton, J.H.; Jones, E.F.; Gore, P.M.; Kormicki, J.; Xie, H.; Kern, B.D.; Krane, K.S.; Xu, Y.S.; Mantica, P.F. Jr.; Zimmermann, B.E.; Nettles, W.G.; Zganjar, E.F.; Kortelahti, M.O.; Newbolt, W.B.

    1988-01-01

    The UNISOR on-line nuclear orientation facility (UNISOR/NOF) consists of a 3 He- 4 He dilution refrigerator on line to the isotope separator. Nuclei are implanted directly into a target foil which is soldered to the bottom accessed cold finger of the refrigerator. A 1.5 T superconducting magnet polarizes the ferromagnetic target foils and determines the axis of symmetry. Up to eight gamma detectors can be positioned around the refrigerator, each 9 cm from the target. A unique feature of this system is that the k=4 term in the directional distribution function can be directly and unambigously deduced so that a single solution for the mixing ratio can be found. The first on-line experiment at this facility reported here was a study of the decay of the 191 Hg and 193 Hg isotopes. (orig.)

  15. Making the most of on-line recruiting.

    Cappelli, P

    2001-03-01

    Ninety percent of large U.S. companies are already recruiting via the Internet. By simply logging on to the Web, company recruiters can locate vast numbers of qualified candidates for jobs at every level, screen them in minutes, and contact the most promising ones immediately. The payoffs can be enormous: it costs substantially less to hire someone on-line, and the time saved is equally great. In this article, Peter Cappelli examines some of the emerging service providers and technologies--matchmakers, job boards, hiring management systems software, and applicant-screening mechanisms that test skills and record interests. He also looks at some of the strategies companies are adopting as they enter on-line labor markets. Recruiting needs to be refashioned to resemble marketing, he stresses. Accordingly, smart companies are designing Web pages, and even product ads, with potential recruits in mind. They're giving line managers authority to hire so that candidates in cyberspace aren't lost. They're building internal on-line job networks to retain talent. Integrating recruiting efforts with overall marketing campaigns, especially through coordination and identification with the company's brand, is the most important thing companies can do to ensure success in on-line hiring. Along the way, Cappelli sounds two cautionary notes. First, a human touch, not electronic contact, is vital in the last steps of a successful hiring process. Second, companies must make sure that on-line testing and hiring criteria do not discriminate against women, disabled people, workers over 40, or members of minority groups. When competition for talent is fierce, companies that master the art and science of on-line recruiting will be the ones that attract and keep the best people.

  16. The User-friendly On-Line Diffusion Chamber

    Aviles Acosta, Jaime

    2015-01-01

    The On-Line Diffusion Chamber is a stand-alone apparatus built to carry out short-live radiotracer diffusion studies. The availability of the on-demand production of isotopes in the ISOLDE facility, and the design of the apparatus to streamline the implantation process, annealing treatment, ion gun ablation with a tape transport system, and radiation intensity measurement with a Ge gamma detector all in the same apparatus, gives the On-Line Diffusion Chamber a unique ability to studies with short-lived radioisotopes or isomer states that are not possible in any other facility in the world.

  17. The rationalization of desulfurization by on-line analysis

    Murakami, Y; Kohmura, S; Taketomi, H; Matsumura, S; Sasaki, Y

    1986-01-01

    Nippon Kokan uses the Takahax and Sulfiban processes for the desulfurization of coke oven gas. The authors outline the Sulfiban Process and describe a recently developed system for the on-line determination of H/sub 2/S in coke oven gas, and of CO/sub 2/ and monoethanolamine (MEA) in the wash oil. This new on-line analysis system has proved effective in rationalizing the Sulfiban Process via lower MEA production costs and decreased power consumption. The introduction of a computerized control system is now being studied. 7 figs., 4 tabs.

  18. 5th Computer Science On-line Conference

    Senkerik, Roman; Oplatkova, Zuzana; Silhavy, Petr; Prokopova, Zdenka

    2016-01-01

    This volume is based on the research papers presented in the 5th Computer Science On-line Conference. The volume Artificial Intelligence Perspectives in Intelligent Systems presents modern trends and methods to real-world problems, and in particular, exploratory research that describes novel approaches in the field of artificial intelligence. New algorithms in a variety of fields are also presented. The Computer Science On-line Conference (CSOC 2016) is intended to provide an international forum for discussions on the latest research results in all areas related to Computer Science. The addressed topics are the theoretical aspects and applications of Computer Science, Artificial Intelligences, Cybernetics, Automation Control Theory and Software Engineering.

  19. Comparison of Current On-line Payment Technologies

    Mandadi, Ravi

    2006-01-01

    The purpose of this thesis work was to make a survey of current on-line payment technologies and find out which are they and how do they work? Compare and analyze them from a security point of view, as well as a usability point of view. What is good? What is bad? What is lacking? To achieve this purpose, an overview of the current on-line payment technologies was acquired through academic books and papers, Internet sites, magazines. Basic cryptographic and security related techniques were stu...

  20. An on-line adaptive core monitoring system

    Verspeek, J.A.; Bruggink, J.C.; Karuza, J.

    1997-01-01

    An on-line core monitoring system has been in operation for three years in the Dodewaard Nuclear Power Plant. The core monitor uses the on-line measured reactor data as an input for a power distribution calculation. The measurements are frequently performed. The system is used for monitoring as well as for predicting purposes. The limiting thermal hydraulic parameters are monitored as well as the pellet-clad interaction limits. The data are added to a history file used for cycle burn-up calculations and trending of parameters. The reactor states are presented through a convenient graphical user interface. (authors)

  1. On-Line Generation of 3D-Waves

    Frigaard, Peter

    1992-01-01

    The paper describes the technique of filtering white noise for on-line generation of 3D-waves on a small computer in the laboratory. The wave generation package is implemented and tested in the 3D-wave basin at the University of Aalborg.......The paper describes the technique of filtering white noise for on-line generation of 3D-waves on a small computer in the laboratory. The wave generation package is implemented and tested in the 3D-wave basin at the University of Aalborg....

  2. Estimating sediment discharge: Appendix D

    Gray, John R.; Simões, Francisco J. M.

    2008-01-01

    Sediment-discharge measurements usually are available on a discrete or periodic basis. However, estimates of sediment transport often are needed for unmeasured periods, such as when daily or annual sediment-discharge values are sought, or when estimates of transport rates for unmeasured or hypothetical flows are required. Selected methods for estimating suspended-sediment, bed-load, bed- material-load, and total-load discharges have been presented in some detail elsewhere in this volume. The purposes of this contribution are to present some limitations and potential pitfalls associated with obtaining and using the requisite data and equations to estimate sediment discharges and to provide guidance for selecting appropriate estimating equations. Records of sediment discharge are derived from data collected with sufficient frequency to obtain reliable estimates for the computational interval and period. Most sediment- discharge records are computed at daily or annual intervals based on periodically collected data, although some partial records represent discrete or seasonal intervals such as those for flood periods. The method used to calculate sediment- discharge records is dependent on the types and frequency of available data. Records for suspended-sediment discharge computed by methods described by Porterfield (1972) are most prevalent, in part because measurement protocols and computational techniques are well established and because suspended sediment composes the bulk of sediment dis- charges for many rivers. Discharge records for bed load, total load, or in some cases bed-material load plus wash load are less common. Reliable estimation of sediment discharges presupposes that the data on which the estimates are based are comparable and reliable. Unfortunately, data describing a selected characteristic of sediment were not necessarily derived—collected, processed, analyzed, or interpreted—in a consistent manner. For example, bed-load data collected with

  3. Integrated sensor array for on-line monitoring micro bioreactors

    Krommenhoek, E.E.

    2007-01-01

    The “Fed��?batch on a chip��?��?project, which was carried out in close cooperation with the Technical University of Delft, aims to miniaturize and parallelize micro bioreactors suitable for on-line screening of micro-organisms. This thesis describes an electrochemical sensor array which has been

  4. On-Line Pesticide Training with Narrated Powerpoint Presentations

    Johnson, Steven B.

    2015-01-01

    UMaine Cooperative Extension is the primary educational delivery organization for pesticide recertification credits in Maine. Shrinking budgets and staff numbers are making traditional face-to-face delivery increasingly difficult to maintain. To address this issue, on-line pesticide applicator recertification training credits were developed. The…

  5. Personality Interactions and Scaffolding in On-Line Discussions

    Nussbaum, E. Michael; Hartley, Kendall; Sinatra, Gale M.; Reynolds, Ralph E.; Bendixen, Lisa D.

    2004-01-01

    The potential of on-line discussions to prompt greater reflection of course material is often stymied by a tendency of students to agree with one another rather than to formulate counter-arguments. This article describes an experiment using note starters and elaborated cases to encourage counter-argumentation and examines interactions with…

  6. A new electrostatic on-line collection-system

    Dufour, J.P.; Del Moral, R.; Fleury, A.; Hubert, F.; Llabador, Y.; Mauhourat, M.B.; Bimbot, R.; Gardes, D.; Rivet, M.F.

    1981-01-01

    The working conditions of a new on-line electrostatic collection system are presented. The main characteristics are high efficiency (reaching 20%) and short delay time (down to the millisecond). The salient features of specific devices for measurements of absolute cross sections, recoil range distributions and angular distributions are given. (orig.)

  7. Specialization processes in on-line unsupervised learning

    Biehl, M.; Freking, A.; Reents, G.; Schlösser, E.

    1998-01-01

    From the recent analysis of supervised learning by on-line gradient descent in multilayered neural networks it is known that the necessary process of student specialization can be delayed significantly. We demonstrate that this phenomenon also occurs in various models of unsupervised learning. A

  8. A simulation of the SDC on-line processing farm

    Wang, C.; Chen, Y.; Dorenbosch, J.; Lee, J.; Sayle, R.

    1993-10-01

    In the Solenoidal Detector Collaboration (SDC) data acquisition system (DAQ), an enormous amount of data flows into a processor farm for extraction of interesting physics events. To design an efficient on-line filter, the operations in the farm must be carefully modeled. The authors present a simulation model developed at the Superconducting Super Collider Laboratory which efficiently allocates physics events to the farm

  9. On-Line Synthesis and Analysis by Mass Spectrometry

    Bain, Ryan M.; Pulliam, Christopher J.; Raab, Shannon A.; Cooks, R. Graham

    2015-01-01

    In this laboratory experiment, students learn how to use ESI to accelerate chemical synthesis and to couple it with on-line mass spectrometry for structural analysis. The Hantzsch synthesis of symmetric 1,4-dihydropyridines is a classic example of a one-pot reaction in which multiple intermediates can serve to indicate the progress of the reaction…

  10. An optimal algorithm for preemptive on-line scheduling

    Chen, B.; Vliet, van A.; Woeginger, G.J.

    1995-01-01

    We investigate the problem of on-line scheduling jobs on m identical parallel machines where preemption is allowed. The goal is to minimize the makespan. We derive an approximation algorithm with worst-case guarantee mm/(mm - (m - 1)m) for every m 2, which increasingly tends to e/(e - 1) ˜ 1.58 as m

  11. Comparison between constant methanol feed and on-line ...

    Two methanol feeding methods, namely constant methanol feed and on-line monitoring feed control by methanol sensor were investigated to improve the production of recombinant human growth hormone (rhGH) in high cell density cultivation of Pichia pastoris KM71 in 2 L bioreactor. The yeast utilized glycerol as a carbon ...

  12. Children's On-Line Processing of Scrambling in Japanese

    Suzuki, Takaaki

    2013-01-01

    This study investigates the on-line processing of scrambled sentences in Japanese by preschool children and adults using a combination of self-paced listening and speeded picture selection tasks. The effects of a filler-gap dependency, reversibility, and case markers were examined. The results show that both children and adults had difficulty in…

  13. AAEC INIS - a large, new, on-line information source

    Rugg, T.J.; Wong, S.C.

    1984-01-01

    The Australian Atomic Energy Commission's INIS database is available for on-line searching by non-AAEC personnel from all parts of Australia. An introduction to the International Nuclear Information System is followed by information on searching AAEC INIS, AAEC INIS retrieval software and accessing AAEC INIS

  14. ORION-the Omega Remote Interactive On-line System

    Russell, R D; Levratt, B; Lipps, H; Sparrman, P

    1974-01-01

    ORION is a system which permits the manipulation of files, records and characters, remote job submittal and retrieval of output files including the direct loading of remote on-line computers. The system uses the computer hardware of the OMEGA project at CERN and is designed to assist researchers in development and debugging of their programs. (10 refs).

  15. ORION - the OMEGA Remote Interactive On-line System

    Russell, R D; Krieger, M

    1973-01-01

    ORION is a system which permits the manipulation of files, records and characters, remote job submittal and retrieval of output files including the direct loading of remote on-line computers. The system uses the computer hardware of the OMEGA project at CERN, and is designed to assist researchers in development and debugging of their programs.

  16. Booth Library On-Line Circulation System (BLOC

    Paladugu V. Rao

    1971-06-01

    Full Text Available An on-line circulation system developed at a relatively small university library demonstrates that academic libraries with limited funds can develop automated systems utilizing parent institution's computer facilities in a time-sharing mode. In operation since September 1968, using an IBM 360/50 computer and associated peripheral equipment, it provides control over all stack books.

  17. On-line learning from clustered input examples

    Riegler, Peter; Biehl, Michael; Solla, Sara A.; Marangi, Carmela; Marinaro, Maria; Tagliaferri, Roberto

    1996-01-01

    We analyse on-line learning of a linearly separable rule with a simple perceptron. Example inputs are taken from two overlapping clusters of data and the rule is defined through a teacher vector which is in general not aligned with the connection line of the cluster centers. We find that the Hebb

  18. Investigating on-line pornography at the University of Johannesburg

    P. Laughton

    2008-01-01

    Full Text Available The on-line user of today has access to a vast collection of information resources. In addition, the developments in Internet and Web technologies have made it even easier for surfers to anonymously get access to on-line pornography. The purpose of this research was to investigate the extent to which access to on-line pornography at the University of Johannesburg can be managed. For the empirical part of this research 1037 questionnaires were proportionally distributed to and completed by students on all five campuses of the university. The questionnaire consisted of four sections: biographical information; university computer facility usage; university acceptable use policy; and personal experience with university computer facilities. The gender distribution for the sample was almost even, with a total of 49,4% male participants and 50,6% female, with the largest grouping of respondents (61,6% aged between 19 years and 21 years. Of the respondents, 36,7% indicated that exposure to unsolicited pornography did not bother them. When asked to what extent students should have access to pornography, 60,5% stated 'None' while 32,6% believed that 'Restricted' access should be granted for research purposes and 6,9% believed that students should be granted 'Total' access to pornography. Results from the research will be used to manage access to on-line resources at the University of Johannesburg better.

  19. On-line sample treatment - Capillary gas chromatography

    Goosens, EC; de Jong, D; de Jong, GJ; Brinkman, UAT

    Sample pretreatment is often the bottleneck of a trace level analytical procedure. In order to increase performance, increasing attention is therefore being devoted to combining sample pretreatment on-line with the separation technique that has to be used. In the present review, a variety of

  20. A new electrostatic on-line collection-system

    Dufour, J.P.; Del Moral, R.; Fleury, A.

    1981-06-01

    The working conditions of a new on-line electrostatic collection system are presented. The main charactersitics are high efficiency (reaching 20%) and short delay time (down to the millisecond). The salient features of specific devices for measurements of absolute cross sections, recoil range distributions and angular distributions are given

  1. Summary remarks and prospects for on-line nuclear orientation

    Krane, K.S.; Hamilton, J.H.

    1984-01-01

    This paper reviews the use of on-line nuclear orientations as a method for determining hyperfine structure. Historical developments and future prospects for the technique are presented. The role that this technique can play in nuclear spectroscopy and the study of nuclei far from the beta stability are outlined

  2. WMI2, the Student's On-Line Symbolic Calculator

    Kovacs, Zoltan

    2011-01-01

    Student activities focused on discovering mathematics play an important role in the teaching and learning process. WebMathematics Interactive (WMI2) was developed to offer a fast and user-friendly on-line web interface to enhance the quality of both theoretical and applied mathematics courses. For the teacher, in the classroom, it provides…

  3. ADAPTIVE CONTEXT PROCESSING IN ON-LINE HANDWRITTEN CHARACTER RECOGNITION

    Iwayama, N.; Ishigaki, K.

    2004-01-01

    We propose a new approach to context processing in on-line handwritten character recognition (OLCR). Based on the observation that writers often repeat the strings that they input, we take the approach of adaptive context processing. (ACP). In ACP, the strings input by a writer are automatically

  4. Microcomputers as on-line catalogs in special libraries.

    Faust, J B

    1986-01-01

    This article discusses the rationale for the conversion of a card catalog to an on-line system in a special library owning approximately 4000 titles. Equipment, software, and procedures are described. Pros and cons of the use of a microcomputer for such a project, as well as costs and personnel needs, are outlined.

  5. Efficient and secure comparison for on-line auctions

    Damgard, Ivan; Geisler, M.; Kroigaard, M.; Pieprzyk, J.; Ghodosi, H.; Dawson, E.

    2007-01-01

    We propose a protocol for secure comparison of integers based on homomorphic encryption. We also propose a homomorphic encryption scheme that can be used in our protocol and makes it more efficient than previous solutions. Our protocol is well-suited for application in on-line auctions, both with

  6. The on-line asymmetric traveling salesman problem

    Ausiello, G.; Bonifaci, V.; Laura, L.

    2008-01-01

    We consider two on-line versions of the asymmetric traveling salesman problem with triangle inequality. For the homing version, in which the salesman is required to return in the city where it started from, we give a -competitive algorithm and prove that this is best possible. For the nomadic

  7. Facing regulatory challenges of on-line hemodiafiltration.

    Kümmerle, Wolfgang

    2011-01-01

    On-line hemodiafiltration (on-line HDF) is the result of a vision that triggered multifarious changes in very different areas. Driven by the idea to offer better medical treatment for renal patients, technological innovations were developed and established that also constituted new challenges in the field of regulatory affairs. The existing regulations predominantly addressed the quality and safety of those products needed to perform dialysis treatment which were supplied by industrial manufacturers. However, the complexity of treatment system required for the provision of on-line fluids demanded a holistic approach encompassing all components involved. Hence, focus was placed not only on single products, but much more on their interfacing, and the clinical infrastructure, in particular, had to undergo substantial changes. The overall understanding of the interaction between such factors, quite different in their nature, was crucial to overcome the arising regulatory obstacles. This essay describes the evolution of the on-line HDF procedure from the regulatory point of view. A simplified diagram demonstrates the path taken from the former regulatory understanding to the realization of necessary changes. That achievement was only possible through 'management of preview' and consequent promotion of technical and medical innovations as well as regulatory re-evaluations. Copyright © 2011 S. Karger AG, Basel.

  8. Project development and commercialization of on-line analysis systems

    Watt, J.S.

    1997-01-01

    A project team first in the Australian Atomic Energy Commission (AAEC) and since 1982 in CSIRO has developed many on-line analysis systems for the mineral and energy industries. The development of these projects has followed a common pattern of laboratory R and D, field trials, commercialisation and technology transfer. This successful pattern is illustrated using examples of the development of systems for the on-line analysis of mineral slurries, for determination of the ash content of coal on conveyors, and for determination of the flow rates of oil, water and gas in pipelines. The first two systems are licensed to Australian companies, Amdel Ltd and Mineral Control Instrumentation Ltd. Both systems are used by industry worldwide, and are the market leaders for radioisotope gauges in their application field. The third system, the multiphase flow meter, was licensed in 1997 to Kvaerner FSSL Ltd of Aberdeen. This meter has even greater potential than the other two systems for economic benefit from its used and for numbers of installations. The on-line analysis systems have been developed to increase the productivity of the Australian mineral and energy industries, and to provide economic benefit to Australia. The economic benefit sought is predominantly improved process control based on use of the instrument, rather than from its sale. Sales of instruments are significant, however, with about A$80 million from the analysis systems and their derivatives since the 1970s. Some of the issues associated with the development of the on-line analysis system are outlined

  9. IOOS Data Portals and Uniform On-line Browse Capabilities

    Howard, M.; Currier, R. D.; Kobara, S.; Gayanilo, F.

    2015-12-01

    The Gulf of Mexico Coastal Ocean Observing System Regional Association (GCOOS-RA) is one of eleven Regional Associations organized under the NOAA-led U.S. Integrated Ocean Observing System (IOOS) Program Office. Each of the RAs operate standards-based regional data portals designed to aggregate near real-time and historical observed data and modeled outputs from distributed providers and to offer these and derived products in standardized ways to a diverse set of users. The RA's portals are based on the IOOS Data and Communications Plan which describes the functional elements needed for an interoperable system. One of these elements is called "Uniform On-line Browse" which is an informational service designed primarily to visualize the inventory of a portal. An on-line browse service supports the end user's need to discover what parameters are available, to learn the spatial and temporal extend of the holdings, and to examine the character of the data (e.g, variability, gappiness, etc). These pieces of information help the end user decide if the data are fit for his/her purpose and to construct valid data requests. Note that on-line browse is a distinctly different activity than data analysis because it seeks to yield knowledge about the inventory and not about what the data mean. "Uniform" on-line browse is a service that takes advantage of the standardization of the data portal's data access points. Most portals represent station locations on a map. This is a view of the data inventory but these plots are rarely generated by pulling data through the standards-based services offered to the end users but through methods only available to the portal programmers. This work will present results of Uniform On-line browse tools developed within GCOOS-RA and their applicability to other RA portals.

  10. Mentoring Narratives ON-LINE:Teaching the Principalship

    Allison I. Griffith

    2002-05-01

    Full Text Available The need to develop new models for preparation of school administrators has been a prominent concern in educational discourse in the last decade. Having been criticized for the inadequate preparation of the school leadership cadre, academic departments responsible for training future school administrators have had to revisit their approaches and to reframe their teaching philosophies to ensure the readiness of their graduates for the challenges and complexities of school leadership. This article reports on the new model of principals' training that has been used in York University's Principals' Qualification Program (PQP from the late 1990s onward. One component of the program brings traditional case methodology into a computer-mediated/on-line environment. The on-line cases are narratives from the everyday lives of the Ontario school administrators who serve as mentors in the on-line environment. Situating our discussion within the context of the rapidly changing educational landscape of Ontario, we focus on the PQP model to explore experientially generated case narratives as one method for teaching and learning the work of the local school administrator. We focus particularly on the teaching and learning embedded in computer-mediated or on-line case narratives used in training teachers for school leadership. We argue that the complexities of school leadership—the social, cultural, relational, ethical and moral context of school leadership—can be taught effectively through the reflective processes of on-line case narratives. We seek to contribute to the ongoing dialogue on the potential of new pedagogies and new technologies to help prepare the competent and responsible leaders for tomorrow's schools.

  11. On-line system for control of plasma filament position in the Tokamak-10

    Britousov, N.N.; Valuev, S.F.; Sychev, G.I.; Shchedrov, V.M.

    1982-01-01

    The plasma filament position on-line control system (OCS) in the T-10 tokamak is described. Results of adjustment and operation of the system are given. The OCS is a structure of a direct negative feedback (DNF) versus deflection and a local DNF circuit. The OCS experimental studying is carried out under the following conditions: 200 kA plasma current, 32 cm diaphragm radius, 2.2-2.5 stability margin, 440 V anode voltage. The response time for 2 cm deflection jumps is 15-20 ns. The OCS demonstrated a particular efficiency while operating in parallel with the plasma current stabilizer providing a high discharge repetition and considerably reducing the number of substandard pulses

  12. Design of an on-line monitoring system for radioactive wastewater

    Qin Guoxiu; Youning Xu; Lei Wang; Xuesong Zhang; Wenping Zhou; Weizhe Li

    2017-01-01

    An on-line monitoring system for radioactive wastewater was designed to discriminate the type and concentration of the radionuclides discharged from nuclear facilities. An HPGe semiconductor was used as the detector in the system for continuous monitoring by pumping wastewater. The minimum detectable activity for 137 Cs was 0.4 Bq L -1 after 10 min of measuring wastewater with the system. The system can detect excessive radioactivity in the wastewater and quickly and effectively alert personnel. Based on the experimental measurements and the Monte Carlo simulation, the detection efficiency of the system was calibrated, and an efficiency curve was determined for the energy range from 50 to 2754 keV. (author)

  13. Influence of expander components on the processes at the negative plates of lead-acid cells on high-rate partial-state-of-charge cycling. Part I: Effect of lignosulfonates and BaSO{sub 4} on the processes of charge and discharge of negative plates

    Pavlov, D.; Nikolov, P.; Rogachev, T. [Institute of Electrochemistry and Energy Systems, Bulgarian Academy of Sciences, Acad. Georgi Bonchev Street, bl. 10, Sofia 1113 (Bulgaria)

    2010-07-15

    This study investigates the influence of the organic expander component (Vanisperse A) and of BaSO{sub 4} on the performance of negative lead-acid battery plates on high-rate partial-state-of-charge (HRPSoC) cycling. Batteries operating in the HRPSoC mode should be classified as a separate type of lead-acid batteries. Hence, the additives to the negative plates should differ from the conventional expander composition. It has been established that lignosulfonates are adsorbed onto the lead surface and thus impede the charge processes, which results in impaired reversibility of the charge-discharge processes and hence shorter cycle life on HRPSoC operation, limited by sulfation of the negative plates. BaSO{sub 4} exerts the opposite effect: it improves the reversibility of the processes in the HRPSoC mode and hence prolongs the cycle life of the cells. The most pronounced effect of BaSO{sub 4} has been registered when it is added in concentration of 1.0 wt.% versus the leady oxide (LO) used for paste preparation. It has also been established that BaSO{sub 4} lowers the overpotential of PbSO{sub 4} nucleation. The results of the present investigation indicate that BaSO{sub 4} affects also the crystallization process of Pb during cell charging. Thus, BaSO{sub 4} eventually improves the performance characteristics of lead-acid cells on HRPSoC cycling. (author)

  14. Vessel Sewage Discharges

    Vessel sewage discharges are regulated under Section 312 of the Clean Water Act, which is jointly implemented by the EPA and Coast Guard. This homepage links to information on marine sanitation devices and no discharge zones.

  15. On-line analysis of water contamination by organic compounds; On-line-Analytik der Wasserverschmutzung durch organische Substanzen

    Wagt, R. van der; Vos, F. de [Skalar Analytical (Netherlands); Babichenko, S.; Poryvkina, L. [Institute of Ecology, Tallinn (Estonia)

    1999-08-01

    In many environmental applications decomposing the mixture of substances in the water into its various chemical ingredients, for subsequent analysis, is a very complicated task. The most productive approach to on-line diagnosis is to treat the object as an integral spectroscopic sample, characterized by certain specific Spectral Fluorescent Signatures (SFS). The SFS are recorded as a matrix of fluorescent intensity of organic compounds in water, in co-ordinates of excitation and emission spectra, providing a three-dimensional spectrum. Spectral windows of SFS are defined by fluorescent characteristics of basic groups of organic substances in the water sample. The novel Skalar Fluo Imager, based on this principle, is intended for the analysis of organic compounds in natural, domestic, and technological waters in an on-line mode. (orig.) [German] In vielen Umweltschutzanwendungen stellt die Auftrennung eines Substanzgemisches zum Zweck der Analyse eine sehr komplizierte Aufgabe dar. Ein erfolgversprechender Ansatz fuer eine on-line-Diagnostik besteht darin, das Objekt als integrale Spektroskopieprobe zu betrachten, die durch bestimmte spezifische Spektral-Fluoreszenz-Signaturen (SFS) charakterisiert wird. Diese werden als Fluoreszenz-Intensitaets-Matrix organischer Verbindungen in Wasser dargestellt, mit Anregungs- und Emissionsspektren als weiteren Koordinaten, wodurch ein dreidimensionales Spektrum entsteht. Spektrale Fenster der SFS sind definiert als Fluoreszenzcharakteristika von Funktionsgruppen organischer Substanzen in der Wasserprobe. Der auf diesem Prinzip basierende Skalar Fluo Imager ist fuer die on-line-Analyse organischer Bestandteile in natuerlichen, Haus- und technischen Waessern gedacht. (orig.)

  16. Automatic Delineation of On-Line Head-And-Neck Computed Tomography Images: Toward On-Line Adaptive Radiotherapy

    Zhang Tiezhi; Chi Yuwei; Meldolesi, Elisa; Yan Di

    2007-01-01

    Purpose: To develop and validate a fully automatic region-of-interest (ROI) delineation method for on-line adaptive radiotherapy. Methods and Materials: On-line adaptive radiotherapy requires a robust and automatic image segmentation method to delineate ROIs in on-line volumetric images. We have implemented an atlas-based image segmentation method to automatically delineate ROIs of head-and-neck helical computed tomography images. A total of 32 daily computed tomography images from 7 head-and-neck patients were delineated using this automatic image segmentation method. Manually drawn contours on the daily images were used as references in the evaluation of automatically delineated ROIs. Two methods were used in quantitative validation: (1) the dice similarity coefficient index, which indicates the overlapping ratio between the manually and automatically delineated ROIs; and (2) the distance transformation, which yields the distances between the manually and automatically delineated ROI surfaces. Results: Automatic segmentation showed agreement with manual contouring. For most ROIs, the dice similarity coefficient indexes were approximately 0.8. Similarly, the distance transformation evaluation results showed that the distances between the manually and automatically delineated ROI surfaces were mostly within 3 mm. The distances between two surfaces had a mean of 1 mm and standard deviation of <2 mm in most ROIs. Conclusion: With atlas-based image segmentation, it is feasible to automatically delineate ROIs on the head-and-neck helical computed tomography images in on-line adaptive treatments

  17. Early discharge following birth

    Nilsson, Ingrid M. S.; Kronborg, Hanne; Knight, Christopher H.

    2017-01-01

    .26–0.48) and primiparous compared to multiparous had an OR of 0.22 (CI 0.17–0.29) for early discharge. Other predictors for early discharge were: no induction of labour, no epidural painkiller, bleeding less than 500 ml during delivery, higher gestational age, early expected discharge and positive breastfeeding experience...

  18. Heart attack - discharge

    ... and lifestyle Cholesterol - drug treatment Controlling your high blood pressure Deep vein thrombosis - discharge Dietary fats explained Fast food tips Heart attack - discharge Heart attack - what to ask your doctor Heart bypass ... pacemaker - discharge High blood pressure - what to ask your doctor How to read ...

  19. Electrodeless discharge lamp is easily started, has high stability

    Bell, W. E.; Bloom, A. L.

    1966-01-01

    Electrodeless discharge borosilicate glass lamp is used in various high-resolution optical systems. It is partially charged with krypton, contains small amounts of rubidium, and is enclosed in a hermetically sealed envelope that maintains the lamp at an optimum temperature during discharge. The lamp is quickly started by its excitation coil.

  20. Novel Approach for Lithium-Ion Battery On-Line Remaining Useful Life Prediction Based on Permutation Entropy

    Luping Chen

    2018-04-01

    Full Text Available The degradation of lithium-ion battery often leads to electrical system failure. Battery remaining useful life (RUL prediction can effectively prevent this failure. Battery capacity is usually utilized as health indicator (HI for RUL prediction. However, battery capacity is often estimated on-line and it is difficult to be obtained by monitoring on-line parameters. Therefore, there is a great need to find a simple and on-line prediction method to solve this issue. In this paper, as a novel HI, permutation entropy (PE is extracted from the discharge voltage curve for analyzing battery degradation. Then the similarity between PE and battery capacity are judged by Pearson and Spearman correlation analyses. Experiment results illustrate the effectiveness and excellent similar performance of the novel HI for battery fading indication. Furthermore, we propose a hybrid approach combining Variational mode decomposition (VMD denoising technique, autoregressive integrated moving average (ARIMA, and GM(1,1 models for RUL prediction. Experiment results illustrate the accuracy of the proposed approach for lithium-ion battery on-line RUL prediction.

  1. On-line soft sensing in upstream bioprocessing.

    Randek, Judit; Mandenius, Carl-Fredrik

    2018-02-01

    This review provides an overview and a critical discussion of novel possibilities of applying soft sensors for on-line monitoring and control of industrial bioprocesses. Focus is on bio-product formation in the upstream process but also the integration with other parts of the process is addressed. The term soft sensor is used for the combination of analytical hardware data (from sensors, analytical devices, instruments and actuators) with mathematical models that create new real-time information about the process. In particular, the review assesses these possibilities from an industrial perspective, including sensor performance, information value and production economy. The capabilities of existing analytical on-line techniques are scrutinized in view of their usefulness in soft sensor setups and in relation to typical needs in bioprocessing in general. The review concludes with specific recommendations for further development of soft sensors for the monitoring and control of upstream bioprocessing.

  2. On-line corrosion monitoring in district heating systems

    Richter, Sonja; Thorarinsdottir, R.I.; Hilbert, Lisbeth Rischel

    2004-01-01

    ), Electrochemical Noise (EN) and Zero Resistance Ammetry (ZRA). Electrochemical Resistance (ER) has also been used to measure corrosion. The method traditionally only measures corrosion off-line but with newly developed high-sensitive ER technique developed by MetriCorr in Denmark, on-line monitoring is possible...... complicates the chemistry of the environment. Hydrogen sulphide is present in geothermal systems and can be formed as a by-product of sulphate-reducing-bacteria (SRB). The application of electrochemical methods makes on-line monitoring possible. These methods include: Linear Polarization Resistance (LPR....... In order to assess both general corrosion and localized corrosion, it is necessary to apply more than one monitoring technique simultaneously, ZRA or EN for measuring localized corrosion and LPR or ER for measuring general corrosion rate. The advantage of monitoring localized corrosion is indisputable...

  3. On-line sources of toxicological information in Canada

    Racz, William J.; Ecobichon, Donald J.; Baril, Marc

    2003-01-01

    This paper will provide an overview of the on-line resources available in toxicology in Canada. It will describe a brief history of The Society of Toxicology of Canada, with reference to other societies and also provide information on education, research and other resources related to toxicology. Toxicology in Canada emerged as a distinct and vibrant discipline following the thalidomide tragedy of the 1960s. In the pharmaceutical industry and government, toxicology was readily established as an essential component of drug development and safety, and as the need for toxicologists expanded, training programs were established, usually in collaboration with departments of pharmacology. In the last two to three decades other disciplines, environmental biology, analytical chemistry and epidemiology joined the ranks of toxicology. The on-line sources of toxicology information are rapidly expanding. This article describes those sources considered by the authors to be important from a national and international perspective. The majority of these sources are professional organizations and government agencies

  4. On-line chemistry monitoring for the secondary side

    Anon.

    1990-01-01

    Babcock and Wilcox (B and W) has developed a computerized water chemistry data acquisition and management system for nuclear plant secondary coolant systems. The Integrated Water Chemistry Monitoring System (IWCMS) provides on-line monitoring of conditions and rapid trend analysis of sampled data. So far it has been installed at GPU Three Mile Island unit 1 and at Toledo Edison Davis-Besse. The IWCMS meets the following utility needs for monitoring power plant chemistry: control of chemistry conditions to minimize corrosion and extend component/system life; continuous analysis of data from on-line detectors and grab samples; expediting of transient recovery actions with trend, alarm and evaluation capability; provision for rapid sharing of useful operational chemistry information; concentration of attention on evaluation instead of data manipulation. The system is composed of three functional parts: data acquisition hardware; PC-based computer system and customised system software. (author)

  5. On-line application of the PANTHER advanced nodal code

    Hutt, P.K.; Knight, M.P.

    1992-01-01

    Over the last few years, Nuclear Electric has developed an integrated core performance code package for both light water reactors (LWRs) and advanced gas-cooled reactors (AGRs) that can perform a comprehensive range of calculations for fuel cycle design, safety analysis, and on-line operational support for such plants. The package consists of the following codes: WIMS for lattice physics, PANTHER whole reactor nodal flux and AGR thermal hydraulics, VIPRE for LWR thermal hydraulics, and ENIGMA for fuel performance. These codes are integrated within a UNIX-based interactive system called the Reactor Physics Workbench (RPW), which provides an interactive graphic user interface and quality assurance records/data management. The RPW can also control calculational sequences and data flows. The package has been designed to run both off-line and on-line accessing plant data through the RPW

  6. UniFlex - Collaborative on-line learning environment tool

    Ole Borch

    2004-05-01

    Full Text Available

    Første gang publiceret i UNEV nr. 2: E-læringsplatforme - muligheder og potentialer, januar - marts 2004, red. Tom Nyvand og Michael Pedersen. ISSN 1603-5518.

    Increasing demands for remote on-line education are changing the way teaching and learning is performed. New behavior in using pedagogy and supporting technology is needed to drive the learning process. To facilitate the use of services for selected activities to participants in distance education, a web site named UniFlex (University Flexible learning has been developed and brought into use. The site is a comprehensive set of bookmarks including course taking, upload/download, and - of special significance - collaborative on-line project work. UniFlex has been developed to meet the requirement for a simple and cheap personalized interactive site, supporting problem oriented and project organized study form, which has characterized Aalborg University for more than 27 years.

  7. UniFlex - Collaborative on-line learning environment tool

    Ole Borch

    2004-03-01

    Full Text Available Første gang publiceret i UNEV nr. 2: E-læringsplatforme - muligheder og potentialer, januar - marts 2004, red. Tom Nyvand og Michael Pedersen. ISSN 1603-5518. Increasing demands for remote on-line education are changing the way teaching and learning is performed. New behavior in using pedagogy and supporting technology is needed to drive the learning process. To facilitate the use of services for selected activities to participants in distance education, a web site named UniFlex (University Flexible learning has been developed and brought into use. The site is a comprehensive set of bookmarks including course taking, upload/download, and - of special significance - collaborative on-line project work. UniFlex has been developed to meet the requirement for a simple and cheap personalized interactive site, supporting problem oriented and project organized study form, which has characterized Aalborg University for more than 27 years.

  8. On-line analyzers to distributed control system linking

    Peterson, S.F.; Buchanan, B.R.; Sanders, M.A.

    1990-01-01

    The Analytical Development Section (ADS) of the Savannah River Laboratory is developing on-line analyzers to monitor various site processes. Data from some of the on-line analyzers (OLA's) will be used for process control by distributed control systems (DCS's) such as the Fisher PRoVOX. A problem in the past has been an efficient and cost effective way to get analyzer data onto the DCS data highway. ADS is developing a system to accomplish the linking of OLA's to PRoVOX DCS's. The system will be described, and results of operation in a research and development environment given. Plans for the installation in the production environment will be discussed.

  9. On-line Ramsey Numbers for Paths and Stars

    Jaroslaw Grytczuk

    2008-08-01

    Full Text Available We study on-line version of size-Ramsey numbers of graphs defined via a game played between Builder and Painter: in one round Builder joins two vertices by an edge and Painter paints it red or blue. The goal of Builder is to force Painter to create a monochromatic copy of a fixed graph H in as few rounds as possible. The minimum number of rounds (assuming both players play perfectly is the on-line Ramsey number r(H of the graph H. We determine exact values of r(H for a few short paths and obtain a general upper bound r(Pn ≤ 4n-7. We also study asymmetric version of this parameter when one of the target graphs is a star Sn with n edges. We prove that r(Sn,H≤n ·e(H when H is any tree, cycle or clique.

  10. Laser systems for on-line laser ion sources

    Geppert, Christopher

    2008-01-01

    Since its initiation in the middle of the 1980s, the resonant ionization laser ion source has been established as a reliable and efficient on-line ion source for radioactive ion beams. In comparison to other on-line ion sources it comprises the advantages of high versatility for the elements to be ionized and of high selectivity and purity for the ion beam generated by resonant laser radiation. Dye laser systems have been the predominant and pioneering working horses for laser ion source applications up to recently, but the development of all-solid-state titanium:sapphire laser systems has nowadays initiated a significant evolution within this field. In this paper an overview of the ongoing developments will be given, which have contributed to the establishment of a number of new laser ion source facilities worldwide during the last five years.

  11. On-Line Metrology with Conoscopic Holography: Beyond Triangulation

    Ignacio Álvarez

    2009-09-01

    Full Text Available On-line non-contact surface inspection with high precision is still an open problem. Laser triangulation techniques are the most common solution for this kind of systems, but there exist fundamental limitations to their applicability when high precisions, long standoffs or large apertures are needed, and when there are difficult operating conditions. Other methods are, in general, not applicable in hostile environments or inadequate for on-line measurement. In this paper we review the latest research in Conoscopic Holography, an interferometric technique that has been applied successfully in this kind of applications, ranging from submicrometric roughness measurements, to long standoff sensors for surface defect detection in steel at high temperatures.

  12. The Bochum on-line data acquisition system

    Paul, H.J.; Freiesleben, H.

    1986-01-01

    We describe an on-line data acquisition system based on a PDP 11 computer with CAMAC hardware. The software fully exploits the real-time features of the RSX-11M operating system. The basic characteristics of the program package, mainly written in FORTRAN 77, are: multitasking, shared common blocks, dynamical access to CAMAC hardware and data, and command orientated user interface. The system is particularly tailored for data acquisition in list mode of up to 64 parameters. (orig.)

  13. Recovery Strategies in On-Line Service Failure

    Ozuem, Wilson; Lancaster, Geoff

    2013-01-01

    Despite a proliferation of a number of studies on service failures and recovery in e-service settings, there is a paucity of knowledge of ways in which service failures and recovery practices are implemented in the fashion industry. Drawing on constructivist perspective, this study offers a new perspective on an effective relational mechanism that would bridge the rupture between consumers and companies particularly in the on-line fashion sector. The analysis adds to studies on service failur...

  14. Understanding Cognitive Load Using On-line Dictionaries

    Robert F. , Dilenschneider

    2017-01-01

    Cognitive Load Theory may useful for language instructors to understand how the look up conditions ofusing an on-line dictionary might influence learning. This paper first reviews previous studies that haveinvestigated dictionary use for vocabulary acquisition and reading comprehension Second, it explainsthe various elements of Cognitive Load Theory. Third, it describes how Cognitive Load Theory appliesto language learners' to learn unknown words and comprehend texts Last, it discusses the pe...

  15. On-line diagnostics for a real time system

    Sreenivasan, P.

    1976-01-01

    The purpose of an on-line diagnostics is to infuse the ability of self diagnosing in an online computer to enhance its dependability in a real time system. Such a diagnostics evolved for the CDPS of the Fast Breeder Test Reactor at Kalpakkam is reported. The two phases of the diagnostics, i.e., the malfunction detection and post detection action are described in some detail. (A.K.)

  16. Isocele I, the Orsay synchrocyclotron on-line separator

    Caruette, A.; Ferro, A.; Foucher, R.

    1976-01-01

    The main characteristics of the isotope separator Isocele 1 are described. This medium current separator was on line with the Orsay synchrocyclotron (155 MeV p, or 210 MeV 3 He) from March 1974 up to May 1975. Results obtained with different targets (Au, Bi, Er, Pt, Sn, Th) are summarized. They confirm the efficiency of medium current separators of this type [fr

  17. A decision support system for on-line leakage localization

    Meseguer, Jordi; Mirats-Tur, Josep M.; Cembrano, Gabriela; Puig, Vicenç; Quevedo, Joseba; Pérez, Ramon; Sanz, Gerard; Ibarra, David

    2014-01-01

    This paper describes a model-driven decision-support system (software tool) implementing a model-based methodology for on-line leakage detection and localization which is useful for a large class of water distribution networks. Since these methods present a certain degree of complexity which limits their use to experts, the proposed software tool focuses on the integration of a method emphasizing its use by water network managers as a decision support system. The proposed software tool integr...

  18. On-line learning in radial basis functions networks

    Freeman, Jason; Saad, David

    1997-01-01

    An analytic investigation of the average case learning and generalization properties of Radial Basis Function Networks (RBFs) is presented, utilising on-line gradient descent as the learning rule. The analytic method employed allows both the calculation of generalization error and the examination of the internal dynamics of the network. The generalization error and internal dynamics are then used to examine the role of the learning rate and the specialization of the hidden units, which gives ...

  19. On-line production of [11C]cyanogen bromide

    Westerberg, G.; Laangstroem, B.

    1997-01-01

    The electrophilic labelling precursor [ 11 C]cyanogen bromide was produced in 95% radiochemical yield (decay-corrected) from hydrogen [ 11 C]cyanide within 3 min from the end of bombardment using a simple and convenient solid-phase on-line procedure. The [ 11 C]cyanogen bromide has been used in the synthesis of a number of labelled compounds for use in positron emission tomography. (author)

  20. On-line Monitoring System for Power Transformers

    Alexandru HOTEA

    2016-12-01

    Full Text Available Power transformers are the most important and expensive equipment from the electricity transmission system, so it is very important to know the real state of health of such equipment in every moment. De-energizing the power transformer accidentally due to internal defects can generate high costs. Annual maintenance proved to be ineffective in many cases to determine the internal condition of the equipment degradation due to faults rapidly evolving. An On-line Monitoring System for Power Transformers help real-time condition assessment and to detect errors early enough to take action to eliminate or minimize them. After abnormality detected, it is still important to perform full diagnostic tests to determine the exact condition of the equipment. On-line monitoring systems can help increase the level of availability and reliability of power transformers and lower costs of accidental interruption. This paper presents cases studies on several power transformers equipped with on-line monitoring systems from Transelectrica substation.

  1. On-Line Fringe Tracking and Prediction at IOTA

    Wilson, Edward; Mah, Robert; Lau, Sonie (Technical Monitor)

    1999-01-01

    The Infrared/Optical Telescope Array (IOTA) is a multi-aperture Michelson interferometer located on Mt. Hopkins near Tucson, Arizona. To enable viewing of fainter targets, an on-line fringe tracking system is presently under development at NASA Ames Research Center. The system has been developed off-line using actual data from IOTA, and is presently undergoing on-line implementation at IOTA. The system has two parts: (1) a fringe tracking system that identifies the center of a fringe packet by fitting a parametric model to the data; and (2) a fringe packet motion prediction system that uses characteristics of past fringe packets to predict fringe packet motion. Combined, this information will be used to optimize on-line the scanning trajectory, resulting in improved visibility of faint targets. Fringe packet identification is highly accurate and robust (99% of the 4000 fringe packets were identified correctly, the remaining 1% were either out of the scan range or too noisy to be seen) and is performed in 30-90 milliseconds on a Pentium II-based computer. Fringe packet prediction, currently performed using an adaptive linear predictor, delivers a 10% improvement over the baseline of predicting no motion.

  2. Review of trigger and on-line processors at SLAC

    Lankford, A.J.

    1984-07-01

    The role of trigger and on-line processors in reducing data rates to manageable proportions in e + e - physics experiments is defined not by high physics or background rates, but by the large event sizes of the general-purpose detectors employed. The rate of e + e - annihilation is low, and backgrounds are not high; yet the number of physics processes which can be studied is vast and varied. This paper begins by briefly describing the role of trigger processors in the e + e - context. The usual flow of the trigger decision process is illustrated with selected examples of SLAC trigger processing. The features are mentioned of triggering at the SLC and the trigger processing plans of the two SLC detectors: The Mark II and the SLD. The most common on-line processors at SLAC, the BADC, the SLAC Scanner Processor, the SLAC FASTBUS Controller, and the VAX CAMAC Channel, are discussed. Uses of the 168/E, 3081/E, and FASTBUS VAX processors are mentioned. The manner in which these processors are interfaced and the function they serve on line is described. Finally, the accelerator control system for the SLC is outlined. This paper is a survey in nature, and hence, relies heavily upon references to previous publications for detailed description of work mentioned here. 27 references, 9 figures, 1 table

  3. On-line plant-wide monitoring using neural networks

    Turkcan, E.; Ciftcioglu, O.; Eryurek, E.; Upadhyaya, B.R.

    1992-06-01

    The on-line signal analysis system designed for a multi-level mode operation using neural networks is described. The system is capable of monitoring the plant states by tracking different number of signals up to 32 simultaneously. The data used for this study were acquired from the Borssele Nuclear Power Plant (PWR type), and using the on-line monitoring system. An on-line plant-wide monitoring study using a multilayer neural network model is discussed in this paper. The back-propagation neural network algorithm is used for training the network. The technique assumes that each physical state of the power plant can be represented by a unique pattern of instrument readings which can be related to the condition of the plant. When disturbance occurs, the sensor readings undergo a transient, and form a different set of patterns which represent the new operational status. Diagnosing these patterns can be helpful in identifying this new state of the power plant. To this end, plant-wide monitoring with neutral networks is one of the new techniques in real-time applications. (author). 9 refs.; 5 figs

  4. Designing effective on-line continuing medical education.

    Zimitat, Craig

    2001-03-01

    The Internet, and new information and communication technologies available through the Internet, provides medical educators with an opportunity to develop unique on-line learning environments with real potential to improve physicians' knowledge and effect change in their clinical practice. There are approximately 100 websites offering on-line CME courses in the USA alone. However, few of these CME courses appear to be based on sound educational principles or CME research and may have little chance of achieving the broader goals of CME. The majority of these courses closely resemble their traditional counterparts (e.g. paper-based books are now electronic books) and appear to be mere substitutions for old-technology CME resources. Whilst some CME providers add unique features of the Internet to enrich their websites, they do not employ strategies to optimize the learning opportunities afforded by this new technology. The adoption of adult learning principles, reflective practice and problem-based approaches can be used as a foundation for sound CME course design. In addition, knowledge of Internet technology and the learning opportunities it affords, together with strategies to maintain participation and new assessment paradigms, are all needed for developing online CME. We argue for an evidence-based and strategic approach to the development of on-line CME courses designed to enhance physician learning and facilitate change in clinical behaviour.

  5. On-line radiation teaching materials using IT technology

    Inoue, Hiroyoshi

    2005-01-01

    We developed the on-line radiation teaching materials using the Internet, in order to provide the teaching support materials of atomic power and radiation educations in on-school study, as well as to create the complementary study system in off-school study. The themes of teaching materials were selected from requests by teachers. In the case of an elementary school, the teaching material 'an environmental problem and atomic power' was created as the aggregate of each content for study without boundary between subjects. The teaching material 'medical treatment and radiation' was created for junior high school students to raise the individual knowledge. In the case of a high school, the teaching material nucleus and radiation' was prepared to supplement the physical study of students. The on-line teaching materials were tried to 300 junior high school and high school students, 68% of students answered that the teaching material is effective to understand atomic power and radiation, though 17% answered they were not effective. Although there are problems to prepare IT learning equipments and learning follow-up system in the material, it is suggested that the on-line teaching materials will provide the novel learning system including debates for the study. This method has no limitation of time and place. (author)

  6. On-line fouling monitor for heat exchangers

    Tsou, J.L.

    1995-01-01

    Biological and/or chemical fouling in utility service water system heat exchangers adversely affects operation and maintenance costs, and reduced heat transfer capability can force a power deaerating or even a plant shut down. In addition, service water heat exchanger performance is a safety issue for nuclear power plants, and the issue was highlighted by NRC in Generic Letter 89-13. Heat transfer losses due to fouling are difficult to measure and, usually, quantitative assessment of the impact of fouling is impossible. Plant operators typically measure inlet and outlet water temperatures and flow rates and then perform complex calculations for heat exchanger fouling resistance or ''cleanliness''. These direct estimates are often imprecise due to inadequate instrumentation. Electric Power Research Institute developed and patented an on-line condenser fouling monitor. This monitor may be installed in any location within the condenser; does not interfere with routine plant operations, including on-line mechanical and chemical treatment methods; and provides continuous, real-time readings of the heat transfer efficiency of the instrumented tube. This instrument can be modified to perform on-line monitoring of service water heat exchangers. This paper discusses the design, construction of the new monitor, and algorithm used to calculate service water heat exchanger fouling

  7. Denmark's on - line early warning radiation monitoring network

    Walmod-Larsen, O.; Lippert, J.

    1990-01-01

    In Denmark an emergency response coordination committee was set up to cope with the problems after the Chernobyl accident with participation of all relevant authorities. For help in an emergency situation the ARGOS (Accident Reporting and Guiding Operational System), system will be put into use. The ARGOS emergency evaluation computer system, which has been developed in cooperation with the Danish Environmental Protection Agency, is in operation in connection with the emergency planning for the east region of Denmark with regard to the Swedish nuclear power plant operating at Barseback. Inputs of measurement data are on-line available on data screens for evaluation in the emergency coordination centers, presented on suitable geographical maps, showing iso-contours calculated from the input. In case of an alert situation other systems can be put in operation, f.ex. mobile measuring units from the CDEPA's local, operational emergency centers. Their readings can then be put into the computing system parallel to the on-line stations and be presented by the ARGOS-system for evaluation in the emergency command centers. If another national authority in an alert situation requests a transfer of measurement data, and if this is agreed upon by the competent Danish authority, then the transfer can be arranged from the ARGOS-system, through agreed transmission channels. At present the ARGOS system is being improved and expanded by RNL to cover the whole Danish region and to present measurements from the on-line warning system

  8. On-line measurement of oil contaminants in water by filter-based infrared analyzers

    Niemelae, P.

    1994-01-01

    The properties of a dedicated infrared analyzer for on-line measurement of the oil content of water, the Oili analyzer, are evaluated theoretically and with laboratory measurements. The analyzer was originally developed for controlling the discharge of ballast and bilge water from oil tankers and more than 200 such instruments have now been supplied for that purpose, representing about 10 % of the total market. Some technical improvements are suggested, and the improved instrument is shown to be capable of measuring oil in water to an accuracy of +- 20 % down to a detection limit of +5-10 ppm in the presence of high concentrations of interfering components and under varying environmental conditions. This opens up new potential applications for the instrument, e.g. the monitoring of water discharges from oil and gas production platforms. The infrared analyzer responds only to the dispersed oil fraction, and if the dissolved fraction is of interest as well, the instrument must be equipped with a UV option, as suggested here

  9. Microprocessor-based, on-line decision aid for resolving conflicting nuclear reactor instrumentation

    Alesso, H.P.

    1981-01-01

    We describe one design for a microprocessor-based, on-line decision aid for identifying and resolving false, conflicting, or misleading instrument indications resulting from certain systems interactions for a pressurized water reactor. The system processes sensor signals from groups of instruments that track together under nominal transient and certain accident conditions, and alarms when they do not track together. We examine multiple-casualty systems interaction and formulate a trial grouping of variables that track together under specified conditions. A two-of-three type redundancy check of key variables provides alarm and indication of conflicting information when one signal suddenly tracks in opposition due to multiple casualty, instrument failure, and/or locally abnormal conditions. Since a vote count of two of three variables in conflict as inconclusive evidence, the system is not designed to provide tripping or corrective action, but improves the operator/instrument interface by providing additional and partially digested information

  10. On line surveillance of large systems: applications to nuclear and chemical plant

    Zwingelstein, G.

    1978-01-01

    An on line surveillance method for large scale and distributed parameter systems is achieved by comparing in real time the internal physical parameter values to the reference values. It is shown that the following steps are necessary: modeling, model validation using dynamic testing and on line estimation of parameters. For large scale systems where only few outputs are measurable, an estimation algorithm was developed, selecting the measurable output giving the minimum variance of the physical parameters. This estimation scheme uses a quasilinearization technique associated to the sensitivity equation and the recursive least squares techniques. For large scale systems of order greater than 100, two versions of the estimation scheme are proposed to decrease the computation time. An application to a nuclear reactor core (state variable model of order 29) is proposed and used real data. For distributed systems the estimation scheme was developed with either measurements at fixed time or at fixed space. The estimation algorithm selects the set of measurements that gives the minimum variance of the estimates. An application to a liquid-liquid extraction column, modelized by a set of four coupled partial differential equations, demonstrates the efficiency of the method

  11. GRACE-based estimates of water discharge over the Yellow River basin

    Qiong Li

    2016-05-01

    Full Text Available As critical component of hydrologic cycle, basin discharge is a key issue for understanding the hydrological and climatologic related to water and energy cycles. Combining GRACE gravity field models with ET from GLDAS models and precipitation from GPCP, discharge of the Yellow River basin are estimated from the water balance equation. While comparing the results with discharge from GLDAS model and in situ measurements, the results reveal that discharge from Mosaic and CLM GLDAS model can partially represent the river discharge and the discharge estimation from water balance equation could reflect the discharge from precipitation over the Yellow River basin.

  12. In the Jungle of Astronomical On--line Data Services

    Egret, D.

    The author tried to survive in the jungle of astronomical on--line data services. In order to find efficient answers to common scientific data retrieval requests, he had to collect many pieces of information, in order to formulate typical user scenarios, and try them against a number of different data bases, catalogue services, or information systems. He discovered soon how frustrating treasure coffers may be when their keys are not available, but he realized also that nice widgets and gadgets are of no help when the information is not there. And, before long, he knew he would have to navigate through several systems because no one was yet offering a general answer to all his questions. I will present examples of common user scenarios and show how they were tested against a number of services. I will propose some elements of classification which should help the end-user to evaluate how adequate the different services may be for providing satisfying answers to specific queries. For that, many aspects of the user interaction will be considered: documentation, access, query formulation, functionalities, qualification of the data, overall efficiency, etc. I will also suggest possible improvements to the present situation: the first of them being to encourage system managers to increase collaboration between one another, for the benefit of the whole astronomical community. The subjective review I will present, is based on publicly available astronomical on--line services from the U.S. and from Europe, most of which (excepting the newcomers) were described in ``Databases and On-Line Data in Astronomy", (Albrecht & Egret, eds, 1991): this includes databases (such as NED and Simbad ), catalog services ( StarCat , DIRA , XCatScan , etc.), and information systems ( ADS and ESIS ).

  13. On-line implant reconstruction in HDR brachytherapy

    Kolkman-Deurloo, Inger-Karine K.; Kruijf, Wilhelmus J.M. de; Levendag, Peter C.

    2006-01-01

    Background and purpose: To evaluate the accuracy of on-line planning in an Integrated Brachytherapy Unit (IBU) using dedicated image distortion correction algorithms, correcting the geometric distortion and magnetic distortion separately, and to determine the effect of the reconstruction accuracy on clinical treatment plans in terms of deviations in treatment time and dose. Patients and methods: The reconstruction accuracy has been measured using 20 markers, positioned at well known locations in a QA phantom. Treatment plans of two phantoms representing clinical implant geometries, have been compared with reference plans to determine the effect of the reconstruction accuracy on the treatment plan. Before clinical introduction, treatment plans of three representative patients, based on on-line reconstruction, have been compared with reference plans. Results: The average reconstruction error for 10 in. images reduces from -0.6 mm (range -2.6 to +1.0 mm) to -0.2 mm (range -1.2 to +0.6 mm) after image distortion correction and for 15 in. images from 0.8 mm (range -0.5 to +3.0 mm) to 0.0 mm (range -0.8 to +0.8 mm). The error in case of eccentric positioning of the phantom, i.e. 0.8 mm (range -1.0 to +3.3 mm), reduces to 0.1 mm (range -0.5 to +0.9 mm). Correction of the image distortions reduces the deviation in the calculated treatment time of maximally 2.7% to less than 0.8% in case of eccentrically positioned clinical phantoms. The deviation in the treatment time or reference dose in the plans based on on-line reconstruction with image distortion correction of the three patient examples is smaller than 0.3%. Conclusions: Accurate on-line implant reconstruction using the IBU localiser and dedicated correction algorithms separating the geometric distortion and the magnetic distortion is possible. The results fulfill the minimum requirements as imposed by the Netherlands Commission on Radiation Dosimetry (NCS) without limitations regarding the usable range of the field

  14. On-line data processing for scintillation camera

    Ueyanagi, Hideo

    1974-01-01

    To process on-line the information from scintillation cameras, the computing/processing device of wired program type, with a specialized mini-computer for the processing, is generally used; and by this method, the data processing is done by the users of scintillation cameras. In the device with a mini-computer with processing programming by software, the almost all items in processing can be executed; but the operation requires some skill. With mini-computer operation, on the other hand, there are the problems of data-point number, process-time reduction, and image storage for both long and short terms. (Mori, K.)

  15. Robust Control Methods for On-Line Statistical Learning

    Capobianco Enrico

    2001-01-01

    Full Text Available The issue of controlling that data processing in an experiment results not affected by the presence of outliers is relevant for statistical control and learning studies. Learning schemes should thus be tested for their capacity of handling outliers in the observed training set so to achieve reliable estimates with respect to the crucial bias and variance aspects. We describe possible ways of endowing neural networks with statistically robust properties by defining feasible error criteria. It is convenient to cast neural nets in state space representations and apply both Kalman filter and stochastic approximation procedures in order to suggest statistically robustified solutions for on-line learning.

  16. Development of an on-line radon monitoring system

    Guo Huiping; Shang Aiguo; Liu Junfeng; Zhou Chunlin; Di Yuming

    2004-01-01

    Of the actual demand by the strategic missile troops, the author has successfully developed a specially designed passive diffusion collecting chamber to collect the decay products of radon by high voltage static electricity, and using the single-chip microcomputer to reckon the radon concentration in air, which is actually a portable, continuous and automatic on-line monitoring instrument. It was made into a four-slot standard plug-in board of a NIM, and it functions as auto data memory, data process, display, over-threshold alarming and so on. (authors)

  17. Integrated on-line accelerator modeling at CEBAF

    Bowling, B.A.; Shoaee, H.; Van Zeijts, J.; Witherspoon, S.; Watson, W.

    1995-01-01

    An on-line accelerator modeling facility is currently under development at CEBAF. The model server, which is integrated with the EPICS control system, provides coupled and 2nd-order matrices for the entire accelerator, and forms the foundation for automated model- based control and diagnostic applications. Four types of machine models are provided, including design, golden or certified, live, and scratch or simulated model. Provisions are also made for the use of multiple lattice modeling programs such as DIMAD, PARMELA, and TLIE. Design and implementation details are discussed. 2 refs., 4 figs

  18. On-line Dynamic Security Assessment in Power Systems

    Weckesser, Johannes Tilman Gabriel

    and solar radiation. Moreover, ongoing research suggests that demand response will be introduced to maintain power balance between generation and consumption at all times. Due to these changes the operating point of the power system will be less predictable and today’s stability and security assessment...... for early prediction of critical voltage sags is described. The method’s performance is compared to other prediction approaches. The results show that the proposed method succeeds in early, accurately and consistently predicting critically low voltage sags. An efficient on-line DSA not only identifies...

  19. Enhancing Learner Autonomy in an On-line Editing Programme

    Hebe Wong

    2011-09-01

    Full Text Available Little (1999 argues that in formal educational contexts, “the basis of learner autonomy is acceptance of responsibility for one’s own learning” (p.11. An autonomous learner takes responsibility for various aspects of learning (Benson & Voller, 1997; Holec, 1981. This study examines how learner autonomy opportunities were provided at various stages of writing in an on-line editing programme for a group of electronic engineering students and how the students took charge of their language learning when receiving feedback on their technical writing. The impact on their own learning effectiveness of the decisions students made is also discussed.

  20. Investigating on-line pornography at the University of Johannesburg

    P. Laughton

    2007-12-01

    (61,6% aged between 19 years and 21 years. Of the respondents, 36,7% indicated that exposure to unsolicited pornography did not bother them. When asked to what extent students should have access to pornography, 60,5% stated 'None' while 32,6% believed that 'Restricted' access should be granted for research purposes and 6,9% believed that students should be granted 'Total' access to pornography. Results from the research will be used to manage access to on-line resources at the University of Johannesburg better.

  1. On-line core monitoring with CORE MASTER / PRESTO

    Lindahl, S.O.; Borresen, S.; Ovrum, S.

    1986-01-01

    Advanced calculational tools are instrumental in improving reactor plant capacity factors and fuel utilization. The computer code package CORE MASTER is an integrated system designed to achieve this objective. The system covers all main activities in the area of in-core fuel management for boiling water reactors; design, operation support, and on-line core monitoring. CORE MASTER operates on a common data base, which defines the reactor and documents the operating history of the core and of all fuel bundles ever used

  2. Core on-line monitoring and computerized procedures systems

    Gangloff, W.C.

    1986-01-01

    The availability of operating nuclear power plants has been affected significantly by the difficulty people have in coping with the complexity of the plants and the operating procedures. Two ways to use modern computer technology to ease the burden of coping are discussed in this paper, an on-line core monitoring system with predictive capability and a computerized procedures system using live plant data. These systems reduce human errors by presenting information rather than simply data, using the computer to manipulate the data, but leaving the decisions to the plant operator

  3. Lower Bounds and Semi On-line Multiprocessor Scheduling

    T.C. Edwin Cheng

    2003-10-01

    Full Text Available We are given a set of identical machines and a sequence of jobs from which we know the sum of the job weights in advance. The jobs have to be assigned on-line to one of the machines and the objective is to minimize the makespan. An algorithm with performance ratio 1.6 and a lower bound of 1.5 is presented. This improves recent results by Azar and Regev who published an algorithm with performance ratio 1.625 for the less general problem that the optimal makespan is known in advance.

  4. Adaptive calibration method with on-line growing complexity

    Šika Z.

    2011-12-01

    Full Text Available This paper describes a modified variant of a kinematical calibration algorithm. In the beginning, a brief review of the calibration algorithm and its simple modification are described. As the described calibration modification uses some ideas used by the Lolimot algorithm, the algorithm is described and explained. Main topic of this paper is a description of a synthesis of the Lolimot-based calibration that leads to an adaptive algorithm with an on-line growing complexity. The paper contains a comparison of simple examples results and a discussion. A note about future research topics is also included.

  5. The development of an on-line gold analyser

    Robert, R.V.D.; Ormrod, G.T.W.

    1982-01-01

    An on-line analyser to monitor the gold in solutions from the carbon-in-pulp process is described. The automatic system is based on the delivery of filtered samples of the solutions to a distribution valve for measurement by flameless atomic-absorption spectrophotometry. The samples is introduced by the aerosol-deposition method. Operation of the analyser on a pilot plant and on a full-scale carbon-in-pulp plant has shown that the system is economically feasible and capable of providing a continuous indication of the efficiency of the extraction process

  6. NNDC [National Nuclear Data Center] on-line services documentation

    Dunford, C.L.; Burrows, T.W.; Tuli, J.K.

    1987-01-01

    This document summarizes and describes how to access the on-line services available from the National Nuclear Data Center (NNDC) located at Brookhaven National Laboratory. The services are available free of cost to US Department of Energy, its contractors and others who support the NNDC or supply data to the NNDC. Four of the center's data bases are now accessible to non-NNDC scientists via remote connection to the center's VAX 11/780. To use this service, you must have a terminal with access by either a telephone line or the PHYSNET network. A VT100 terminal or a terminal with VT-100 emulation is recommended but not required

  7. Efficient and Secure Comparison for On-Line Auctions

    Damgård, Ivan Bjerre; Krøigaard, Mikkel; Geisler, Martin Joakim

    2007-01-01

    We propose a protocol for secure comparison of integers based on homomorphic encryption. We also propose a homomorphic encryption scheme that can be used in our protocol and makes it more efficient than previous solutions. Our protocol is well-suited for application in on-line auctions, both...... with respect to functionality and performance. It minimizes the amount of information bidders need to send, and for comparison of 16 bit numbers with security based on 1024 bit RSA (executed by two parties), our implementation takes 0.28 seconds including all computation and communication. Using precomputation...

  8. On-line computing in a classified environment

    O'Callaghan, P.B.

    1982-01-01

    Westinghouse Hanford Company (WHC) recently developed a Department of Energy (DOE) approved real-time, on-line computer system to control nuclear material. The system simultaneously processes both classified and unclassified information. Implementation of this system required application of many security techniques. The system has a secure, but user friendly interface. Many software applications protect the integrity of the data base from malevolent or accidental errors. Programming practices ensure the integrity of the computer system software. The audit trail and the reports generation capability record user actions and status of the nuclear material inventory

  9. On-line fatigue monitoring and margins probabilistic assessment

    Fournier, I.; Morilhat, P.

    1993-01-01

    An on-line computer aided system has been developed by Electricite de France, the French utility, for a fatigue monitoring of critical locations in the nuclear steam supply system. This tool, called fatiguemeter, includes as input data only existing plant parameters and is based on some conservative assumptions at several steps of the damage assessment (thermal boundary conditions, stress computation...). This paper presents recent developments performed toward a better assessing of margins involved in the complete analysis. The methodology is enlightened with an example showing the influence of plant parameters incertitude on the final stress computed at a PWR 900 MW unit pressurizer surge line nozzle. (author)

  10. On-line system for investigation of atomic structure

    Amus'ya, M.Ya.; Chernysheva, L.V.

    1983-01-01

    A description of the on-line ATOM system is presented that enables to investigate the structure of atomic electron shells and their interactions with different scattering particles-electrons, positronse photons, mesons - with the use of computerized numerical solutions. The problem is stated along with mathematical description of atomic properties including theoretical and numerical models for each investigated physical process. The ATOM system structure is considered. The Hartree-Fock method is used to determine the wave functions of the ground and excited atomic states. The programs are written in the ALGOL langauge. Different atomic characteristics were possible to be calculated for the first time with an accuracy exceeding an experimental one

  11. ELT-MELAS analyzer and its on-line programs

    Anikeev, V.B.; Berezhnoj, V.A.; Glupova

    1976-01-01

    ELT-MELAS device constructed for an automatic analysis of pictures from big bubble chambers is described. It is controlled by a medium-size ICL-1903A computer and has two measuring modes: analysis of the ''agreement'' signal and digitation of slice-scans. Main features of the hardware and of on-line controlling and diagnostic software are presented. The test results of the MELAS complex as well as preliminary results of the scan-slice measurements of pictures from 15sup(') chamber are given

  12. Computational physics of electric discharges in gas flows

    Surzhikov, Sergey T

    2012-01-01

    Gas discharges are of interest for many processes in mechanics, manufacturing, materials science and aerophysics. To understand the physics behind the phenomena is of key importance for the effective use and development of gas discharge devices. This worktreats methods of computational modeling of electrodischarge processes and dynamics of partially ionized gases. These methods are necessary to tackleproblems of physical mechanics, physics of gas discharges and aerophysics.Particular attention is given to a solution of two-dimensional problems of physical mechanics of glow discharges.The use o

  13. Human comment dynamics in on-line social systems

    Wu, Ye; Zhou, Changsong; Chen, Maoying; Xiao, Jinghua; Kurths, Jürgen

    2010-12-01

    Human comment is studied using data from ‘tianya’ which is one of the most popular on-line social systems in China. We found that the time interval between two consecutive comments on the same topic, called inter-event time, follows a power-law distribution. This result shows that there is no characteristic decay time on a topic. It allows for very long periods without comments that separate bursts of intensive comments. Furthermore, the frequency of a different ID commenting on a topic also follows a power-law distribution. It indicates that there are some “hubs” in the topic who lead the direction of the public opinion. Based on the personal comments habit, a model is introduced to explain these phenomena. The numerical simulations of the model fit well with the empirical results. Our findings are helpful for discovering regular patterns of human behavior in on-line society and the evolution of the public opinion on the virtual as well as real society.

  14. On-Line Core Thermal-Hydraulic Model Improvement

    In, Wang Kee; Chun, Tae Hyun; Oh, Dong Seok; Shin, Chang Hwan; Hwang, Dae Hyun; Seo, Kyung Won

    2007-02-01

    The objective of this project is to implement a fast-running 4-channel based code CETOP-D in an advanced reactor core protection calculator system(RCOPS). The part required for the on-line calculation of DNBR were extracted from the source of the CETOP-D code based on analysis of the CETOP-D code. The CETOP-D code was revised to maintain the input and output variables which are the same as in CPC DNBR module. Since the DNBR module performs a complex calculation, it is divided into sub-modules per major calculation step. The functional design requirements for the DNBR module is documented and the values of the database(DB) constants were decided. This project also developed a Fortran module(BEST) of the RCOPS Fortran Simulator and a computer code RCOPS-SDNBR to independently calculate DNBR. A test was also conducted to verify the functional design and DB of thermal-hydraulic model which is necessary to calculate the DNBR on-line in RCOPS. The DNBR margin is expected to increase by 2%-3% once the CETOP-D code is used to calculate the RCOPS DNBR. It should be noted that the final DNBR margin improvement could be determined in the future based on overall uncertainty analysis of the RCOPS

  15. Utilities enticing customers to come on-line

    Anon

    2000-01-01

    The first tentative steps by electric utilities to offer customer services on-line is reported. While most of the on-line communications to date has been merely to present information about products and services, at least a few utilities, -- Newfoundland Power being one of them -- are now offering customers the opportunity to check on their account status, to make inquiries, and on a voluntary basis employees of the utility can receive their bills on the web. BC Hydro is even more advanced; it has offered a similar service since 1997. The option to pay bills at the BC Hydro website is coming shortly. U. S. utility companies are reported to be far more advanced in the use of the Internet; according to a study by Deloitte Consulting, U.S. utilities are advancing to the next stage wherein Web intermediaries will be offering 'shop bots' that do comparison shopping on behalf of a customer, including bidding for power on a customer's behalf at energy auctions, reverse auctions, where sellers are bidding for customers' services, and buyers clubs where customers join together to take advantage of volume buying power

  16. On-line monitoring and inservice inspection in codes

    Bartonicek, J.; Zaiss, W.; Bath, H.R.

    1999-01-01

    The relevant regulatory codes determine the ISI tasks and the time intervals for recurrent components testing for evaluation of operation-induced damaging or ageing in order to ensure component integrity on the basis of the last available quality data. In-service quality monitoring is carried out through on-line monitoring and recurrent testing. The requirements defined by the engineering codes elaborated by various institutions are comparable, with the KTA nuclear engineering and safety codes being the most complete provisions for quality evaluation and assurance after different, defined service periods. German conventional codes for assuring component integrity provide exclusively for recurrent inspection regimes (mainly pressure tests and optical testing). The requirements defined in the KTA codes however always demanded more specific inspections relying on recurrent testing as well as on-line monitoring. Foreign codes for ensuring component integrity concentrate on NDE tasks at regular time intervals, with time intervals scope of testing activities being defined on the basis of the ASME code, section XI. (orig./CB) [de

  17. Polar On-Line Acquisition Relay and Transmission System (POLARATS)

    Yuracko, K.

    2004-07-15

    POLARATS (Polar On-Line Acquisition Relay And Transmission System) is being developed by YAHSGS LLC (YAHSGS) and Oak Ridge National Laboratory (ORNL) to provide remote, unattended monitoring of environmental parameters under harsh environmental conditions. In particular, instrumental design and engineering is oriented towards protection of human health in the Arctic, and with the additional goal of advancing Arctic education and research. POLARATS will obtain and transmit environmental data from hardened monitoring devices deployed in locations important to understanding atmospheric and aquatic pollutant migration as it is biomagnified in Arctic food chains. An Internet- and personal computer (PC)-based educational module will provide real time sensor data, on-line educational content, and will be integrated with workbooks and textbooks for use in middle and high school science programs. The educational elements of POLARATS include an Internet-based educational module that will instruct students in the use of the data and how those data fit into changing Arctic environments and food chains. POLARATS will: (1) Enable students, members of the community, and scientific researchers to monitor local environmental conditions in real time over the Internet; and (2) Provide additional educational benefits through integration with middle- and high-school science curricula. Information will be relayed from POLARATS devices to classrooms and libraries along with custom-designed POLARATS teaching materials that will be integrated into existing curricula to enhance the educational benefits realized from the information obtained.

  18. Aria Sardinia: the on line community joining tradition and innovatiom

    Fabrizio Lao

    2005-12-01

    Full Text Available The "ARIA Sardinia" project (Network Actions for Italians Abroad has been especially designed to integrate and give value to the network of relationships between public administrations, local socio-economic stakeholders and Italian communities abroad, this goal to be pursued with the support of new technologies and learning approaches emerging within the context of on line interest communities. The general objective of the project is the development of competencies and knowledge, intended to combine specific technical skills with local "territorial knowledge", in a process where the strengthening and the dissemination of these forms of culture come from the prompt use of innovative tools. The main activities of the project are the actions intended to guide and assist entrepreneurs, associations, development projects' partners or promoters in the path of acquisition and dissemination of the competencies which are necessary to the involvement of Italians abroad into the internationalization process of Sardinian economy. ARIA Sardinia was funded by the Italian Foreign Affairs Ministry and the European Social Fund (FSE, within the framework of the National Operational Program for Technical Assistance and System Action (PON ATAS aimed at specific promotion initiatives and fostering of permanent links between Southern Italy economy and Italians living abroad. Keywords: on line community, networking, Italians abroad, Sardinian economy, Sardinia, culture.

  19. On-Line Core Thermal-Hydraulic Model Improvement

    In, Wang Kee; Chun, Tae Hyun; Oh, Dong Seok; Shin, Chang Hwan; Hwang, Dae Hyun; Seo, Kyung Won

    2007-02-15

    The objective of this project is to implement a fast-running 4-channel based code CETOP-D in an advanced reactor core protection calculator system(RCOPS). The part required for the on-line calculation of DNBR were extracted from the source of the CETOP-D code based on analysis of the CETOP-D code. The CETOP-D code was revised to maintain the input and output variables which are the same as in CPC DNBR module. Since the DNBR module performs a complex calculation, it is divided into sub-modules per major calculation step. The functional design requirements for the DNBR module is documented and the values of the database(DB) constants were decided. This project also developed a Fortran module(BEST) of the RCOPS Fortran Simulator and a computer code RCOPS-SDNBR to independently calculate DNBR. A test was also conducted to verify the functional design and DB of thermal-hydraulic model which is necessary to calculate the DNBR on-line in RCOPS. The DNBR margin is expected to increase by 2%-3% once the CETOP-D code is used to calculate the RCOPS DNBR. It should be noted that the final DNBR margin improvement could be determined in the future based on overall uncertainty analysis of the RCOPS.

  20. The Automated Threaded Fastening Based on On-line Identification

    Nicolas Ivan Giannoccaro

    2008-11-01

    Full Text Available The principle of the thread fastenings have been known and used for decades with the purpose of joining one component to another. Threaded fastenings are popular because they permit easy disassembly for maintenance, repair, relocation and recycling. Screw insertions are typically carried out manually. It is a difficult problem to automat. As a result there is very little published research on automating threaded fastenings, and most research on automated assembly focus on the peg-in-hole assembly problem. This paper investigates the problem of automated monitoring of the screw insertion process. The monitoring problem deals with predicting integrity of a threaded insertion, based on the torque vs. insertion depth curve generated during the insertions. The authors have developed an analytical model to predict the torque signature signals during self-tapping screw insertions. However, the model requires parameters on the screw dimensions and plate material properties are difficult to measure. This paper presents a study on on-line identification during screw fastenings. An identification methodology for two unknown parameter estimation during a self-tapping screw insertion process is presented. It is shown that friction and screw properties required by the model can be reliably estimated on-line. Experimental results are presented to validate the identification procedure.

  1. Calibration through on-line monitoring of instruments channels

    James, R.W.

    1996-01-01

    Plant technical specifications require periodic calibration of instrument channels, and this has traditionally meant calibration at fixed time intervals for nearly all instruments. Experience has shown that unnecessarily frequent calibrations reduce channel availability and reliability, impact outage durations, and increase maintenance costs. An alternative approach to satisfying existing requirements for periodic calibration consists of on-line monitoring and quantitative comparison of instrument channels during operation to identify instrument degradation and failure. A Utility Working Group has been formed by EPRI to support the technical activities necessary to achieve generic NRC acceptance of on-line monitoring of redundant instrument channels as a basis for determining when to perform calibrations. A topical report proposing NRC acceptance of this approach was submitted in August 1995, and the Working Group is currently resolving NRC technical questions. This paper describes the proposed approach and the current status of the topical report with regard to NRC review. While these activities will not preclude utilities from continuing to use existing calibration approaches, successful acceptance of this performance-based approach will allow utilities to substantially reduce the number of calibrations which are performed. Concurrent benefits will include reduced I ampersand C impact on outage durations and improved sensitivity to instrument channel performance

  2. On-line optimal control improves gas processing

    Berkowitz, P.N.; Papadopoulos, M.N.

    1992-01-01

    This paper reports that the authors' companies jointly funded the first phase of a gas processing liquids optimization project that has the specific purposes to: Improve the return of processing natural gas liquids, Develop sets of control algorithms, Make available a low-cost solution suitable for small to medium-sized gas processing plants, Test and demonstrate the feasibility of line control. The ARCO Willard CO 2 gas recovery processing plant was chosen as the initial test site to demonstrate the application of multivariable on-line optimal control. One objective of this project is to support an R ampersand D effort to provide a standardized solution to the various types of gas processing plants in the U.S. Processes involved in these gas plants include cryogenic separations, demethanization, lean oil absorption, fractionation and gas treating. Next, the proposed solutions had to be simple yet comprehensive enough to allow an operator to maintain product specifications while operating over a wide range of gas input flow and composition. This had to be a supervisors system that remained on-line more than 95% of the time, and achieved reduced plant operating variability and improved variable cost control. It took more than a year to study various gas processes and to develop a control approach before a real application was finally exercised. An initial process for C 2 and CO 2 recoveries was chosen

  3. Amdel on-line analyser at Rooiberg Tin Limited

    Owen, T.V.

    1987-01-01

    An Amdel on line analysis system was installed on the 'A' mine tin flotation plant at Rooiberg in April 1984. The motivation for the installation was made on account of the large variations in the feed grade to the plant and the resulting need for rapid operational adjustments to control concentrate grades thereby maximising the financial returns. An 'on-line' analyser system presented itself as a suitable alternative to the existing control method of smaller laboratory x-ray fluorescence analysers. On the system as installed at Rooiberg, two probes were fitted in each analysis zone, viz a density probe using high energy gamma radiation from a Cesium 127 source and a specific element absorption probe using low energy gamma radiation from a Americium 241 source. The signals as received from the probes are fed to a line receiver unit in the control room where a micro computer is doing the processing and prints out the information as required. Several advantages of this type of installation were gained at Rooiberg Tin Limited

  4. On-line Social Interactions and Executive Functions

    Oscar eYbarra

    2012-04-01

    Full Text Available A successful social interaction requires fast, on-line, and active construction of an ever-changing mental-model of another’s person beliefs, expectations, emotions, and desires. It also requires the ability to inhibit inappropriate behaviors, problem-solve, take-turns, and pursue goals in a distraction-rich environment. All these tasks rely on executive functions (EF—working memory, attention/cognitive control, and inhibition. Executive functioning has long been viewed as relatively static. However, starting with recent reports of successful cognitive interventions, this view is changing and now EFs are seen as much more open to both short and long term training, warm-up, and exhaustion effects. Some of the most intriguing evidence comes from research showing how social interaction enhances performance on standard EF tests. Interestingly, the latest research indicates these EF benefits are selectively conferred by certain on-line, dynamic social interactions, which require participants to engage with another person and actively construct the model of their mind. We review this literature and highlight its connection with evolutionary and cultural theories emphasizing links between intelligence and social life.

  5. Project development and commercialisation of on-line analysis systems

    Watt, J.S.

    2000-01-01

    A project team first in the Australian Atomic Energy Commission (AAEC) and since 1982 in CSIRO has developed many on-line analysis systems for the mineral and energy industries. The development of these projects, usually lasting 7-10 years, has followed a common pattern of laboratory R and D, field trials, commercialisation and technology transfer. This successful pattern is illustrated using examples of the development of systems for the on-line analysis of mineral slurries, for determination of the ash content of coal on conveyors, and for determination of the flow rates of oil, water and gas in pipelines. The first two systems, licensed to Australian companies, are used world-wide. They are now the market leaders for radioisotope gauges in their application field. The third, the multiphase flow meter, was licensed in 1997 to an international company. This meter has even greater potential than the other two systems for economic benefit from its use and for numbers of installations. (author)

  6. Increased Cortical Thickness in Professional On-Line Gamers

    Hyun, Gi Jung; Shin, Yong Wook; Kim, Bung-Nyun; Cheong, Jae Hoon; Jin, Seong Nam

    2013-01-01

    Objective The bulk of recent studies have tested whether video games change the brain in terms of activity and cortical volume. However, such studies are limited by several factors including cross-sectional comparisons, co-morbidity, and short-term follow-up periods. In the present study, we hypothesized that cognitive flexibility and the volume of brain cortex would be correlated with the career length of on-line pro-gamers. Methods High-resolution magnetic resonance scans were acquired in twenty-three pro-gamers recruited from StarCraft pro-game teams. We measured cortical thickness in each individual using FreeSurfer and the cortical thickness was correlated with the career length and the performance of the pro-gamers. Results Career length was positively correlated with cortical thickness in three brain regions: right superior frontal gyrus, right superior parietal gyrus, and right precentral gyrus. Additionally, increased cortical thickness in the prefrontal cortex was correlated with winning rates of the pro-game league. Increased cortical thickness in the prefrontal and parietal cortices was also associated with higher performance of Wisconsin Card Sorting Test. Conclusion Our results suggest that in individuals without pathologic conditions, regular, long-term playing of on-line games is associated with volume changes in the prefrontal and parietal cortices, which are associated with cognitive flexibility. PMID:24474988

  7. Glow discharging device

    Maeno, Katsuki; Kawasaki, Kozo; Hiratsuka, Hajime; Kawashima, Shuichi.

    1989-01-01

    In a thermonuclear device, etc. impurities adsorbed to inner walls of a vacuum vessel by glow discharge are released to clean the vacuum vessel for preventing intrusion of the impurities into plasmas. The object of the present invention is to minimize the capacity of a power source equipment for the glow discharge device to the least extent. That is, a stabilization resistance is connected in series between each of a plurality of anodes which are inserted and arranged at the inside of a vacuum vessel as a cathode and a power source respectively. The resistance value R is selected so as to satisfy the relation: R < (Vi - Vm)/Ii, in which Vi: glow discharge starting voltage, Vm: glow discharge keeping voltage, Ii: glow discharge starting current. Accordingly, if a voltage is applied from a power source to a plurality of anodes, scattering of electric discharge between the anodes can be suppressed and the effect of voltage drop during discharge by the stabilization resistance can be eliminated. As a result, it is possible to provide an economically advantageous glow discharge device with the capacity for the power source facility being to the least extent. (K.M.)

  8. On-line redox sensors in industrial glass melting tanks

    Laimböck, P.R.; Beerkens, R.G.C.; Schaaf, van der J.; Kieffer, J.

    2002-01-01

    The oxidation state or partial oxygen pressure (pO2) of the glass melt influences many glass melt and glass product properties such as fining and foaming behavior, radiant heat transfer, forming characteristics via (a color-dependent) cooling rate, and the glass color of the final product. For these

  9. CO-AXIAL DISCHARGES

    Luce, J.S.; Smith, L.P.

    1960-11-22

    A method and apparatus are given for producing coaxial arc discharges in an evacuated enclosure and within a strong, confining magnetic field. The arcs are maintained at a high potential difference. Electrons will diffuse to the more positive arc from the negative arc, and positive ions will diffuse from the more positive arc to the negative arc. Coaxial arc discharges have the advantage that ions which return to strike the positive arc discharge will lose no energy since they do not strike a solid wall or electrode. Those discharges are useful in confining an ionized plasma between the discharges, and have the advantage of preventing impurities from the walls of the enclosure from entering ihe plasma area because of the arc barrier set up bv the cylindrical outer arc.

  10. Modelling electric discharge chemistry

    McFarlane, J.; Wren, J.C.

    1991-07-01

    The chemistry occurring in a electric discharge was modelled to predict how it would be influenced by discharge conditions. The discharge was characterized by a calculated Boltzmann electron-energy distribution, from which rate constants for electron-molecule processes in air were determined. These rate constants were used in a chemical kinetics calculation that also included reactions between neutral molecules, ions, free radicals and electronically excited species. The model describes how the discharge chemistry was influenced by humidity, electric field, electron number density, and concentrations of key reagents identified in the study. The use of an electric discharge to destroy airborne contaminant molecules was appraised, the targeted contaminants being CF 2 Cl 2 , HCN, and SO 2 . The modelling results indicate that an electric discharge should be able to remove HCN and CF 2 Cl 2 effectively, especially if the discharge conditions have been optimized. Effective destruction is achieved with a moderate electric field (over 1 x 10 -15 V.cm 2 ), a substantial electron number density (over 1 x 10 12 cm -3 ), and the presence of H 2 0 in the process air. The residence time in the discharge was also shown to be important in contaminant destruction. An attempt was made to explain the results of the electric discharge abatement of SO 2 , a component of a simulated flue-gas mixture. Results from the model indicate that the discharge parameters that increase the concentration of hydroxyl radical also increase the rate of decomposition of SO 2 . An objective of the study was to explain the apparent enhancement of SO 2 destruction by the presence of a small amount of NO 2 . It was thought that a likely explanation would be the stabilization of HOSO 2 , an important intermediate in the oxidation of SO 2 by NO 2 . (49 figs., 14 tabs., 75 refs.)

  11. Numerical Modelling of Electrical Discharges

    Durán-Olivencia, F J; Pontiga, F; Castellanos, A

    2014-01-01

    The problem of the propagation of an electrical discharge between a spherical electrode and a plane has been solved by means of finite element methods (FEM) using a fluid approximation and assuming weak ionization and local equilibrium with the electric field. The numerical simulation of this type of problems presents the usual difficulties of convection-diffusion-reaction problems, in addition to those associated with the nonlinearities of the charged species velocities, the formation of steep gradients of the electric field and particle densities, and the coexistence of very different temporal scales. The effect of using different temporal discretizations for the numerical integration of the corresponding system of partial differential equations will be here investigated. In particular, the so-called θ-methods will be used, which allows to implement implicit, semi-explicit and fully explicit schemes in a simple way

  12. Central peaking of magnetized gas discharges

    Chen, Francis F.; Curreli, Davide

    2013-01-01

    Partially ionized gas discharges used in industry are often driven by radiofrequency (rf) power applied at the periphery of a cylinder. It is found that the plasma density n is usually flat or peaked on axis even if the skin depth of the rf field is thin compared with the chamber radius a. Previous attempts at explaining this did not account for the finite length of the discharge and the boundary conditions at the endplates. A simple 1D model is used to focus on the basic mechanism: the short-circuit effect. It is found that a strong electric field (E-field) scaled to electron temperature T e , drives the ions inward. The resulting density profile is peaked on axis and has a shape independent of pressure or discharge radius. This “universal” profile is not affected by a dc magnetic field (B-field) as long as the ion Larmor radius is larger than a

  13. Partial tooth gear bearings

    Vranish, John M. (Inventor)

    2010-01-01

    A partial gear bearing including an upper half, comprising peak partial teeth, and a lower, or bottom, half, comprising valley partial teeth. The upper half also has an integrated roller section between each of the peak partial teeth with a radius equal to the gear pitch radius of the radially outwardly extending peak partial teeth. Conversely, the lower half has an integrated roller section between each of the valley half teeth with a radius also equal to the gear pitch radius of the peak partial teeth. The valley partial teeth extend radially inwardly from its roller section. The peak and valley partial teeth are exactly out of phase with each other, as are the roller sections of the upper and lower halves. Essentially, the end roller bearing of the typical gear bearing has been integrated into the normal gear tooth pattern.

  14. On-line determination of moisture in coal and coke

    Cutmore, N.G.; Sowerby, B.D.

    1987-01-01

    The CSIRO Division of Mineral Engineering is developing various techniques for the on-line determination of moisture in coal and coke, and some instruments are now commercially available. These techniques permit accurate and rapid determination of moisture in materials directly on conveyor belts or in bins. The most promising techniques for direct on-belt measurement of moisture in coal are capacitance and microwave transmission. A non-contacting under-belt capacitance and gamma-ray backscatter technique has determined moisture in coal to better than 0.5 wt% in field tests. CSIRO is developing a fast neutron and gamma-ray transmission technique, which is proving very accurate in laboratory tests. This technique overcomes many of the limitations of thermal neutrons moisture gauges

  15. On-line monitoring system for utility boiler diagnostics

    Radovanovic, P.M.; Afgan, N.H.; Caralho, M.G.

    1997-01-01

    The paper deals with the new developed modular type Monitoring System for Utility Boiler Diagnostics. Each module is intended to assess the specific process and can be used as a stand alone application. Four modules are developed, namely: LTC - module for the on-line monitoring of parameters related to the life-time consumption of selected boiler components; TRD - module for the tube rupture detection by the position and working fluid Ieakage quantity; FAM - module for the boiler surfaces fouling (slagging) assessment and FLAP - module for visualization of the boiler furnace flame position. All four modules are tested on respective pilot plants built oil the 200 and 300 MWe utility boilers. Monitoring System is commercially available and can be realized in any combination of its modules depending on demands induced by the operational problems of specific boiler. Further development of Monitoring System is performed in accordance with the respective EU project on development of Boiler Expert System. (Author)

  16. On-line Certification for All: The PINVOX Algorithm

    E Canessa

    2012-09-01

    Full Text Available A protoype algorithm: PINVOX (“Personal Identification Number by Voice" for on-line certification is introduced to guarantee that scholars have followed, i.e., listened and watched, a complete recorded lecture with the option of earning a certificate or diploma of completion after remotely attending courses. It is based on the injection of unique, randomly selected and pre-recorded integer numbers (or single letters or words within the audio trace of a video stream at places where silence is automatically detected. The certificate of completion or “virtual attendance” is generated on-the-fly after the successful identification of the embedded PINVOX code by a video viewer student.

  17. On-line control of the nonlinear dynamics for synchrotrons

    Bengtsson, J.; Martin, I. P. S.; Rowland, J. H.; Bartolini, R.

    2015-07-01

    We propose a simple approach to the on-line control of the nonlinear dynamics in storage rings, based on compensation of the nonlinear resonance driving terms using beam losses as the main indicator of the strength of a resonance. The correction scheme is built on the analysis of the resonance driving terms in first perturbative order and on the possibility of using independent power supplies in the sextupole magnets, which is nowadays present in many synchrotron light sources. Such freedom allows the definition of "smart sextupole knobs" attacking each resonance separately. The compensation scheme has been tested at the Diamond light source and proved to be effective in opening up the betatron tune space, resonance free, available to the electron beam and to improve the beam lifetime.

  18. On-line control of the nonlinear dynamics for synchrotrons

    J. Bengtsson

    2015-07-01

    Full Text Available We propose a simple approach to the on-line control of the nonlinear dynamics in storage rings, based on compensation of the nonlinear resonance driving terms using beam losses as the main indicator of the strength of a resonance. The correction scheme is built on the analysis of the resonance driving terms in first perturbative order and on the possibility of using independent power supplies in the sextupole magnets, which is nowadays present in many synchrotron light sources. Such freedom allows the definition of “smart sextupole knobs” attacking each resonance separately. The compensation scheme has been tested at the Diamond light source and proved to be effective in opening up the betatron tune space, resonance free, available to the electron beam and to improve the beam lifetime.

  19. On-line monitoring system for I-131 manufacturing labs

    Osovizky, A.; Malamud, Y.; Paran, Y.; Tal, N.; Turgeman, S.; Weinstein, M.

    1997-01-01

    An on-line monitoring and safety system has been installed in a lab for manufacturing 1-131 capsules for nuclear medicine use. Production of up to 100mCi batches is performed in shielded glove boxes. The safety system is based on a unique, 'Medi SMARTS' system (Medical Survey Mapping Automatic Radiation Tracing System), that collects continuously the radiation measurements for processing, display, and storage for future retrieval. Radiation is measured by GM tubes, data is transferred to a data processing unit, and then via a RS-485 communication line to a computer. In addition to the operational advantages and radiation levels storage, the system is being evaluated for the purpose of identifying risky stages in the process. (authors)

  20. Issues for Bringing Electron Beam Irradiators On-Line

    Kaye, R.J.; Turman, B.N.

    1999-01-01

    Irradiation of red meat and poultry has been approved by the U.S. FDA, and the U.S. Department of Agriculture's rule for processing red meat is out for comment. Looking beyond the current issues of packaging materials, labeling, and consumer acceptance, this paper reviews the next step of implementation and how to remove, or at least reduce, the barriers to utilization. Polls of the user community identified their requirements for electron beam or x-ray processing of meat or poultry and their concerns about implementation for on-line processing. These needs and issues are compared to the capabilities of the accelerator industry. The critical issues of beam utilization and dose uniformity, factors affecting floor space requirements, and treatment costs are examined

  1. On-line fatigue monitoring system for reactor pressure vessel

    Tokunaga, K.; Sakai, A.; Aoki, T.; Ranganath, S.; Stevens, G.L.

    1994-01-01

    A workstation-based, on-line fatigue monitoring system for tracking fatigue usage applied to an operating boiling water reactor (BWR), Tsuruga Unit-1, is described. The system uses the influence function approach and determines component stresses using temperature, pressure, and flow rate data that are made available via signal taps from previously existing plant sensors. Using plant unique influence functions developed specifically for the feedwater nozzle location, the system calculates stresses as a function of time and computed fatigue usage. The analysis method used to compute fatigue usage complies with MITI Code Notification No.501. Fatigue usage results for an entire fuel cycle are presented and compared to assumed design basis events to confirm that actual plant thermal duty is significantly less severe than originally estimated in the design basis stress report. As a result, the system provides the technical basis to more accurately evaluate actual reactor conditions as well as the justification for plant life extension. (author)

  2. On-line fatigue monitoring and probabilistic assessment of margins

    Fournier, I. [Electricite de France, 93 - Saint-Denis (France). Direction des Etudes et Recherches; Morilhat, P. [Electricite de France, 93 - Saint-Denis (France). Direction des Etudes et Recherches

    1995-01-01

    An on-line computer-aided system has been developed by Electricite de France, the French utility, for fatigue monitoring of critical locations in the nuclear steam supply system. This tool, called a fatigue meter, includes as input data plant parameters and is based on some conservative assumptions at several steps of the damage assessment (thermal boundary conditions, stress computation,..). In this paper we present recent developments performed towards a better assessment of margins involved in the complete analysis. The methodology is illustrated with an example showing the influence of uncertainty in plant parameters on the final stress computed at a pressurized water reactor 900MW unit pressurizer surge line nozzle. A second example is shown to illustrate the possibility of defining some transient archetypes. ((orig.)).

  3. On-line Monitoring of Instrumentation in Research Reactors

    2017-12-01

    This publication is the result of a benchmarking effort undertaken under the IAEA coordinated research project on improved instrumentation and control (I&C) maintenance techniques for research reactors. It lays the foundation for implementation of on-line monitoring (OLM) techniques and establishment of the validity of those for improved maintenance practices in research reactors for a number of applications such as change to condition based calibration, performance monitoring of process instrumentation systems, detection of process anomalies and to distinguish between process problems/effects and instrumentation/sensor issues. The techniques and guidance embodied in this publication will serve the research reactor community in providing the technical foundation for implementation of OLM techniques. It is intended to be used by Member States to implement I&C maintenance and to improve performance of research reactors.

  4. On-line control of nuclear fuel reprocessing

    Parus, I.; Kierzek, J.; Zoltowski, T.

    1977-01-01

    The development trends in the field of chemical processes control and the present state of the development of continuous composition analysers has been described. On this background the peculiarities of on-line control methods for spent nuclear fuel reprocessing have been discussed. The measuring methods for direct and indirect determination of chemical composition and nuclear safety are reviewed in detail. The review comprises such methods as: measurement of α, γ and neutron radiation emitted both by nuclides present in technological solutions and using external sources of different radiation, X-ray fluorescence, measurements of physicochemical parameters connected with the composition (pH, density, electrical conductivity), polarography and spectrophotometry. At the end of this review some new trends in process control based on dynamic process models have been presented. (author)

  5. The Task Manager for the LHCb On-Line Farm

    Bonifazi, F; Carbone, A; Galli, D; Gregori, D; Marconi, U; Peco, G; Vagnoni, V

    2004-01-01

    The Task Manager is a utility to start, stop and list processes on the on-line farm. Each process started by the Task Manager has a string environment variable set, named UTGID (User defined unique Thread Group Identifier) which allows to identify the process. The Task Manager uses the UTGID to list the running processes and to identify the processes to be stopped. It has also the ability to start a process using a particular user name and to set the scheduler type and the priority for the process itself. The Task Manager package includes a Linux DIM server (tmSrv), four Linux command line DIM clients (tmStart, tmLs, tmKill and tmStop) and a JCOP (Joint Control Project) PVSS client.

  6. On-line Corrosion Monitoring in District Heating Systems

    Richter, Sonja; Thorarinsdottir, R.I.; Hilbert, Lisbeth Rischel

    2005-01-01

    The corrosion control in district heating systems is today performed primarily with control of the water quality. The corrosion rate is kept low by assuring low dissolved oxygen concentration, high pH and low conductivity. Corrosion failures can occur, e.g. as a result of unknown oxygen ingress, ......, precipitation of deposits or crevices. The authors describe methods used for on-line monitoring of corrosion, cover the complications and the main results of a Nordic project.......The corrosion control in district heating systems is today performed primarily with control of the water quality. The corrosion rate is kept low by assuring low dissolved oxygen concentration, high pH and low conductivity. Corrosion failures can occur, e.g. as a result of unknown oxygen ingress...

  7. NOASYS, a system for on-line noise analysis

    Massier, H.

    1978-07-01

    This report describes NOASYS, a versatile NOise Analysis SYStem for digital on-line signal processing. The system based on a minicomputer, was originally developed for the analysis of noise signals from nuclear reactors. NOASYS computes various statistical functions e.g. cross- und auto-correlation functions and power spectral densities resp., which may be used for reactor diagnosis and malfunction detection. The system processes up to 16 analog signals with a maximum sampling frequency of 100 kcps (1 channel). The processing of the sampled data is done by a number of software tasks, which may be called from a teletype or linked together for specific measuring programs. The standard configuration contains the often used processing routines e.g. Fast Fourier Transform, complex multiplication, summation etc. In addition NOASYS may be extended by users own tasks (in Assembler or Fortran) to fit for specific applications. (orig.) 891 HP [de

  8. On-line efficiency optimization of a synchronous reluctance motor

    Lubin, Thierry; Razik, Hubert; Rezzoug, Abderrezak [Groupe de Recherche en Electrotechnique et Electronique de Nancy, GREEN, CNRS-UMR 7037, Universite Henri Poincare, BP 239, 54506 Vandoeuvre-les-Nancy Cedex (France)

    2007-04-15

    This paper deals with an on-line optimum-efficiency control of a synchronous reluctance motor drive. The input power minimization control is implemented with a search controller using Fibonacci search algorithm. It searches the optimal reference value of the d-axis stator current for which the input power is minimum. The input power is calculated from the measured dc-bus current and dc-bus voltage of the inverter. A rotor-oriented vector control of the synchronous reluctance machine with the optimization efficiency controller is achieved with a DSP board (TMS302C31). Experimental results are presented to validate the proposed control methods. It is shown that stability problems can appear during the search process. (author)

  9. Development of on-line monitoring system using smart material

    Lee, Jin Kyung; Lee, Sang Pill; Park, Yi Hyun [Dongeui Univ., Busan (Korea, Republic of); Park, Young Chul [Donga Univ., Busan (Korea, Republic of)

    2003-07-01

    A hot press method was used to create the optimal fabrication condition for a Shape Memory Alloy(SMA) composite. The bonding strength between the matrix and the reinforcement within the SMA composite by the hot press method was more increased by cold rolling. In this study, the objective was to develop an on-line monitoring system in order to prevent the crack initiation and propagation by shape memory effect in SMA composite. Shape memory effect was used to prevent the SMA composite from crack propagation. For this system an optimal AE parameter should be determined according to the degree of damage and crack initiation. When the SMA composite was heated by the plate heater attached at the composite, the propagating cracks could be controlled by the compressive force of SMA.

  10. Development of on-line monitoring system using smart material

    Lee, Jin Kyung; Lee, Sang Pill; Park, Yi Hyun; Park, Young Chul

    2003-01-01

    A hot press method was used to create the optimal fabrication condition for a Shape Memory Alloy(SMA) composite. The bonding strength between the matrix and the reinforcement within the SMA composite by the hot press method was more increased by cold rolling. In this study, the objective was to develop an on-line monitoring system in order to prevent the crack initiation and propagation by shape memory effect in SMA composite. Shape memory effect was used to prevent the SMA composite from crack propagation. For this system an optimal AE parameter should be determined according to the degree of damage and crack initiation. When the SMA composite was heated by the plate heater attached at the composite, the propagating cracks could be controlled by the compressive force of SMA

  11. Issues for Bringing Electron Beam Irradiators On-Line

    Kaye, R.J.; Turman, B.N.

    1999-04-20

    Irradiation of red meat and poultry has been approved by the U.S. FDA, and the U.S. Department of Agriculture's rule for processing red meat is out for comment. Looking beyond the current issues of packaging materials, labeling, and consumer acceptance, this paper reviews the next step of implementation and how to remove, or at least reduce, the barriers to utilization. Polls of the user community identified their requirements for electron beam or x-ray processing of meat or poultry and their concerns about implementation for on-line processing. These needs and issues are compared to the capabilities of the accelerator industry. The critical issues of beam utilization and dose uniformity, factors affecting floor space requirements, and treatment costs are examined.

  12. Escapist Motives for Playing On-Line Games

    Sudzina, Frantisek; Razmerita, Liana

    2012-01-01

    Social games have become popular along with the tremendous growth of social networking sites, esp. Facebook. There is a gap in literature on what motivates people to play Facebook games. This paper studies social games usage behavior of students. We focus on escapist reasons, based on Warmelink...... of escapist motives for playing Facebook and other on-line games, we investigate how they are linked to demographic data such as: age, gender, place of origin, along with other social interactions patterns and social network usage behavior, current gaming status and an estimate of gaming time. According...... to our study, only 10% of respondents, who have started to play Facebook games, continued to play them. The most important motives for playing games is mundane breaking, the second reason is pleasure seeking, the third is stress relieving, and the least important is imagination conjuring....

  13. Configuration Database for BaBar On-line

    Salnikov, Andrei

    2003-01-01

    The configuration database is one of the vital systems in the BaBar on-line system. It provides services for the different parts of the data acquisition system and control system, which require run-time parameters. The original design and implementation of the configuration database played a significant role in the successful BaBar operations since the beginning of experiment. Recent additions to the design of the configuration database provide better means for the management of data and add new tools to simplify main configuration tasks. We describe the design of the configuration database, its implementation with the Objectivity/DB object-oriented database, and our experience collected during the years of operation

  14. 3rd Computer Science On-line Conference

    Senkerik, Roman; Oplatkova, Zuzana; Silhavy, Petr; Prokopova, Zdenka

    2014-01-01

    This book is based on the research papers presented in the 3rd Computer Science On-line Conference 2014 (CSOC 2014).   The conference is intended to provide an international forum for discussions on the latest high-quality research results in all areas related to Computer Science. The topics addressed are the theoretical aspects and applications of Artificial Intelligences, Computer Science, Informatics and Software Engineering.   The authors provide new approaches and methods to real-world problems, and in particular, exploratory research that describes novel approaches in their field. Particular emphasis is laid on modern trends in selected fields of interest. New algorithms or methods in a variety of fields are also presented.   This book is divided into three sections and covers topics including Artificial Intelligence, Computer Science and Software Engineering. Each section consists of new theoretical contributions and applications which can be used for the further development of knowledge of everybod...

  15. On-line Ciphers and the Hash-CBC Constructions

    Bellare, M.; Boldyreva, A.; Knudsen, Lars Ramkilde

    2012-01-01

    We initiate a study of on-line ciphers. These are ciphers that can take input plaintexts of large and varying lengths and will output the i th block of the ciphertext after having processed only the first i blocks of the plaintext. Such ciphers permit length-preserving encryption of a data stream...... with only a single pass through the data. We provide security definitions for this primitive and study its basic properties. We then provide attacks on some possible candidates, including CBC with fixed IV. We then provide two constructions, HCBC1 and HCBC2, based on a given block cipher E and a family...... of computationally AXU functions. HCBC1 is proven secure against chosen-plaintext attacks assuming that E is a PRP secure against chosen-plaintext attacks, while HCBC2 is proven secure against chosen-ciphertext attacks assuming that E is a PRP secure against chosen-ciphertext attacks....

  16. On-line defected fuel monitoring using GFP data

    Livingstone, S.; Lewis, B.J.

    2008-01-01

    This paper describes the initial development of an on-line defected fuel diagnostic tool. The tool is based on coolant activity, and uses a quantitative and qualitative approach from existing mechanistic fission product release models, and also empirical rules based on commercial and experimental experience. The model departs from the usual methodology of analyzing steady-state fission product coolant activities, and instead uses steady-state fission product release rates calculated from the transient coolant activity data. An example of real-time defected fuel analysis work is presented using a prototype of this tool with station data. The model is in an early developmental stage, and this paper demonstrates the promising potential of this technique. (author)

  17. An on-line advanced plant simulator (OLAPS)

    Samuels, J.W.

    1989-01-01

    A PC based on-line advanced plant simulator (OLAPS) for high quality simulations of Portland General Electric's Trojan Nuclear Facility is presented. OLAPS is designed to simulate the thermal-hydraulics of the primary system including core, steam generators, pumps, piping and pressurizer. The simulations are based on a five equation model that has two mass equations, two energy equations, two energy equations, and one momentum equation with a drift flux model to provide closure. A regionwise point reactor kinetics model is used to model the neutron kinetics in the core. The conservation equations, constitutive models and the numerical methods used to solve them are described. OLAPS results are compared with data from chapter 15 of the Trojan Nuclear Facility's final safety analysis report

  18. The Monitor System for the LHCb on-line farm

    Bonifazi, F; Carbone, A; Galli, D; Gregori, D; Marconi, U; Peco, G; Vagnoni, V

    2005-01-01

    The aim of the LHCb on-line farm Monitor System is to keep under control all the working indicators which are relevant for the farm operation, and to set the appropriate alarms whenever an error or a critical condition comes up. Since the most stressing tasks of the farm are the data transfer and processing, relevant indicators includes the CPU and the memory load of the system, the network interface and the TCP/IP stack parameters, the rates of the interrupts raised by the network interface card and the detailed status of the running processes. The monitoring of computers’ physical conditions (temperatures, fan speeds and motherboard voltages) are the subject of a separate technical note, since they are accessed in a different way, by using the IPMI protocol.

  19. On-line monitoring of main coolant pump seals

    Stevens, D.M.; Spencer, J.W.; Morris, D.J.; Glass, S.W.; Sommerfield, G.A.; Harrison, D.

    1984-06-01

    The Babcock and Wilcox Company has developed and implemented a Reactor Coolant Pump Monitoring and Diagnostic System (RCPM and DS). The system has been installed at Toledo Edison Company's Davis-Besse Nuclear Power Station Unit 1. The RCPM and PS continuously monitors a number of indicators of pump performance and notifies the plant operator of out-of-tolerance conditions or pump performance trending toward out-of-tolerance conditions. Pump seal parameters being monitored include pump internal pressures, temperatures, and flow rates. Rotordynamic performanvce and plant operating conditions are also measured with a variety of dynamic sensors. This paper describes the implementation of the system and the results of on-line monitoring of four RC pumps

  20. PHEBUS on-line aerosol monitor development test program

    Sprenger, M.H.; Pentecost, C.G.

    1992-03-01

    EG ampersand G Idaho, Inc. developed an on-line aerosol monitor (OLAM) for the French PHEBUS Fission Product Project. Part of the development was to manufacture and test an OLAM prototype. This report presents the results of the testing which determined the mechanical integrity of the monitor at operating temperature and pressure and performed a preliminary test of the optical system. A series of twenty different tests was conducted during the prototype testing sequence. Since no leaks were detected, the OLAM demonstrated that it could provide a pressure boundary at required test conditions. The optical and electrical system also proved its integrity by exceeding the design requirement of less than 105 optical signal drift during an actual two-hour test sequence

  1. On line isotopic separator test benches at GANIL

    Anne, R.; Bru, B.; Joubert, A.; Leroy, R.; Obert, J.; Putaux, J.C.; Liang, C.F.; Paris, P.; Orr, N.; Steckmeyer, J.C.

    1993-01-01

    A first version of isotopic separator on line test bench has been built in order to test the feasibility of the production of radioactive species from 96 MeV/u of 20 Ne impinging a thick target of MgO. This test bench was equipped with a very compact ECR ion source (Nanogan) entirely made from permanent magnets and operating at 10 Ghz. 18 Ne 2,4+ ; 19N e 1,2,3,4+ and 23,24 Ne 1+ has been produced and ionized. A new more performing separator (SIRa) allowing the use of different types of ion sources will be completed by the end of 1993. (author) 4 refs., 4 figs., 1 tab

  2. Semi-continuous on-line uranium ore analyzer

    Campbell, P.; Gurdy, E.M.; Hatchowski, L.

    1984-01-01

    The efficient process control of a uranium mill and its associated mining operation requires a nearly continuous knowledge of the uranium concentration in the ore. Generally, the approach is to use laboratory assays of grab samples from the mill feed belt. In some cases, elaborate and expensive systems have been used to ensure random sampling, but even with these systems, mass-balance discrepancies still exist. There is a requirement for an on-line instrument that can give a prompt, accurate analysis of a large portion of the feed stock. The authors have recently evaluated a laboratory system that achieves these goals using neutron activation and delayed neutron counting. The development of the on-line uranium ore analyzer is a consequence of previous work done at the Whiteshell Nuclear Research Establishment (WNRE) (Campbell et al., 1978 and 1981), and is based on the emission of delayed neutrons after the neutron irradiation of fissionable materials. The mechanism of delayed neutron emission has been described (Keepin, 1965), but briefly is as follows. The fission fragments resulting from irradiation are in an excited state. Certain of these delayed fission products, precursors, decay to a more stable state by the emission of a delayed neutron. The delayed neutrons can be divided into six groups with effective half-lives ranging from 0.2-55 sec. It is important to note that more than 50% of the delayed neutrons are emitted within the first 6 sec after irradiation; this has an influence on the design of the analysis instrument

  3. PHENIX On-Line Distributed Computing System Architecture

    Desmond, Edmond; Haggerty, John; Kehayias, Hyon Joo; Purschke, Martin L.; Witzig, Chris; Kozlowski, Thomas

    1997-01-01

    PHENIX is one of the two large experiments at the Relativistic Heavy Ion Collider (RHIC) currently under construction at Brookhaven National Laboratory. The detector consists of 11 sub-detectors, that are further subdivided into 29 units (''granules'') that can be operated independently, which includes simultaneous data taking with independent data streams and independent triggers. The detector has 250,000 channels and is read out by front end modules, where the data is buffered in a pipeline while awaiting the level trigger decision. Zero suppression and calibration is done after the level accept in custom built data collection modules (DCMs) with DSPs before the data is sent to an event builder (design throughput of 2 Gb/sec) and higher level triggers. The On-line Computing Systems Group (ONCS) has two responsibilities. Firstly it is responsible for receiving the data from the event builder, routing it through a network of workstations to consumer processes and archiving it at a data rate of 20 MB/sec. Secondly it is also responsible for the overall configuration, control and operation of the detector and data acquisition chain, which comprises the software integration for several thousand custom built hardware modules. The software must furthermore support the independent operation of the above mentioned granules, which includes the coordination of processes that run in 60-100 VME processors and workstations. ONOS has adapted the Shlaer- Mellor Object Oriented Methodology for the design of the top layer software. CORBA is used as communication layer between the distributed objects, which are implemented as asynchronous finite state machines. We will give an overview of the PHENIX online system with the main focus on the system architecture, software components and integration tasks of the On-line Computing group ONCS and report on the status of the current prototypes

  4. Progress and performance of on-line analyzers of coal

    Spencer, C.M.; Brown, D.R.; Gozani, T.; Bozorgmanesh, H.; Bernatowicz, H.; Tassicker, O.J.; Karlson, F.

    1982-01-01

    This paper describes the past year's progress in the laboratory testing of the most comprehensive Nucoalyzer, the CONAC, and the performance of a Nucoalyzer-Sulfurmeter in special field tests. Previous papers and presentations provide more detailed background information. The near real-time analysis provided by a Nucoalyzer can be used in a variety of strategies to optimize efficiency of coal use. Nucoalyzers can be used to monitor coal deliveries and achieve uniformity in coal storage and recovery. In a coal cleaning plant, on-line analysis with a Nucoalyzer can lead to optimum Btu recovery while meeting specifications for the washed coal. A Nucoalyzer can monitor the blending of different coals to maintain a key cosntituent such as sulfur below a specified level, or can predict sulfur dioxide emissions, allowing feed-forward control to gas scrubbers and precipitators. Variability in coal feed to the boiler can lead to gross changes in thermodynamic efficiency in combustion. In addition, fouling and slagging incidents due to poor coal quality cause costly boiler shutdowns and maintenance. Nucoalyzer monitoring of key constituents and Btu in the coal feed allows operators to adjust boiler parameters for increased efficiency. To summarize, the primary advantages of Nucoalyzers relate to their ability to quickly identify changes in coal composition so that adjustments can be made in a timely manner to accommodate these changes in the process being monitored. Nucoalyzers are the only instruments available that can monitor the coal (for ash, Btu, sulfur, etc.) on-line and provide real-time continuous results. One Nucoalyzer is already working in the field, and by the time of the next Symposium we will have had performance reports on two more

  5. On-line chemical sensors for applications in fast reactors

    Jayaraman, V.

    2015-01-01

    Hydrogen sensors are essential components of fast reactor sodium circuits. These sensors are needed in fast reactors for the immediate detection of any steam leak into sodium during reactor operation which can lead to failure of steam generator. Depending on the operating power of the reactor, sodium-water reaction results in either an increase in dissolved hydrogen level in sodium or an increase in hydrogen content of argon cover gas used above sodium coolant. Hence, on-line monitoring of hydrogen continuously in sodium and cover circuits helps in detection of any steam leak. In the event of accidental leak of high temperature sodium, it reacts with oxygen and moisture in air leading to sodium fires. These fires produce sodium aerosol containing oxides of sodium (Na 2 O and Na 2 O 2 ) and NaOH. For early detection of sodium fires, sensor systems based on sodium ionization detector, pH measurement and modulation of conductivity of graphite films are known in the literature. This presentation deals with the development of on-line sensors for these two applications. A diffusion based sensor using a thin walled nickel coil at 773 K and a sensitive thermal conductivity detector (TCD) has been developed for monitoring hydrogen levels in argon cover gas. This sensor has a lower detection limit of 30 ppm of hydrogen in argon. To extend the detection limit of the sensor, a surface conductivity based sensor has been developed which makes use of a thin film of semi-conducting tin oxide. Integration of this sensor with the TCD, can extend the lower detection limit to 2 ppm of hydrogen in cover gas. Electrochemical sensor based on sodium-beta-alumina has been designed, fabricated and its performance in laboratory and industrial environment was evaluated. This paper presents the logical development of these sensors highlighting their merits and limitations

  6. Review of Worcestershire On-line Fabric Type Series website

    Beverley Nenk

    2003-06-01

    Full Text Available The study of archaeological ceramics is advanced through the creation and development of regional and national pottery type-series, which contain samples of each type of pottery identified from a particular area or region. Pottery researchers working in any period, from prehistoric to post-medieval, require access to such type-series, and to their associated data, in order to be able to advance the identification of all types of pottery, not only those types produced in the local area, but those produced in surrounding regions, as well as those imported from abroad. The publication of such type-series, as well as their accessibility to researchers, is essential if the information they contain is to be disseminated. The development of the Worcestershire On-Line Fabric Type Series is the first stage in a remarkable project designed to make the complete fabric and form type series for Worcestershire ceramics accessible on the internet. As part of the Historic Environment Record for Worcestershire, formerly the Sites and Monuments Record, it is designed to improve access to finds and environmental data, with the aim of encouraging and facilitating research. Funded by Worcestershire County Council as part of its commitment to e-government, it is being developed by Worcestershire County Council Archaeology Service with OxfordArchDigital. It is one of a proposed series of on-line specialist resources (to include, for example, clay pipes, environmental archaeology, flint tools, historic buildings, which are also designed to stand alone as research tools. The ceramics website is the first part of Pottery in Perspective, a web-based project to provide information on the pottery used and made in Worcestershire from prehistory to c. 1900AD.

  7. Essays on partial retirement

    Kantarci, T.

    2012-01-01

    The five essays in this dissertation address a range of topics in the micro-economic literature on partial retirement. The focus is on the labor market behavior of older age groups. The essays examine the economic and non-economic determinants of partial retirement behavior, the effect of partial

  8. Real-time synchronization of batch trajectories for on-line multivariate statistical process control using Dynamic Time Warping

    González Martínez, Jose María; Ferrer Riquelme, Alberto José; Westerhuis, Johan A.

    2011-01-01

    This paper addresses the real-time monitoring of batch processes with multiple different local time trajectories of variables measured during the process run. For Unfold Principal Component Analysis (U-PCA)—or Unfold Partial Least Squares (U-PLS)-based on-line monitoring of batch processes, batch runs need to be synchronized, not only to have the same time length, but also such that key events happen at the same time. An adaptation from Kassidas et al.'s approach [1] will be introduced to ach...

  9. High sensitivity on-line monitor for radioactive effluent

    Sasaki, Toshimi [Tohoku Electric Power Co. Ltd., Sendai (Japan); Ishizuka, Akira; Abe, Eisuke; Inoue, Yasuhiko; Fujii, Masaaki; Kitaguchi, Hiroshi; Doi, Akira

    1983-04-01

    A new approach for a highly sensitive effluent monitor is presented. The free flow type monitor, which consists of a straightener, nozzle, monitoring section and ..gamma..-ray detector, is demonstrated to be effective in providing long term stability. The 160 start-and-stop cycles of effluent discharge were repeated in a 120-h testing period. Results showed a background increase was not observed for the free flow type monitor. The background count rate was calibrated to the lowest detection limit to be 2.2 x 10/sup -2/ Bq/ml for a 300 s measurement time.

  10. Discharge lamp technologies

    Dakin, James

    1994-01-01

    This talk is an overview of discharge lamp technology commonly employed in general lighting, with emphasis on issues pertinent to lighting for plant growth. Since the audience is primarily from the plant growth community, and this begins the light source part of the program, we will start with a brief description of the discharge lamps. Challenges of economics and of thermal management make lamp efficiency a prime concern in controlled environment agriculture, so we will emphasize science considerations relating to discharge lamp efficiency. We will then look at the spectra and ratings of some representative lighting products, and conclude with a discussion of technological advances.

  11. Capacitor discharge engineering

    Früngel, Frank B A

    1976-01-01

    High Speed Pulse Technology, Volume III: Capacitor Discharge Engineering covers the production and practical application of capacitor dischargers for the generation and utilization of high speed pulsed of energy in different forms. This nine-chapter volume discusses the principles of electric current, voltage, X-rays, gamma rays, heat, beams of electrons, neutrons and ions, magnetic fields, sound, and shock waves in gases and liquids. Considerable chapters consider the applications of capacitor discharges, such as impulse hardening of steel, ultrapulse welding of precision parts, X-ray flash t

  12. Predicting tile drainage discharge

    Iversen, Bo Vangsø; Kjærgaard, Charlotte; Petersen, Rasmus Jes

    used in the analysis. For the dynamic modelling, a simple linear reservoir model was used where different outlets in the model represented tile drain as well as groundwater discharge outputs. This modelling was based on daily measured tile drain discharge values. The statistical predictive model...... was based on a polynomial regression predicting yearly tile drain discharge values using site specific parameters such as soil type, catchment topography, etc. as predictors. Values of calibrated model parameters from the dynamic modelling were compared to the same site specific parameter as used...

  13. Determination of anions with an on-line capillary electrophoresis method; Anionien on-line maeaeritys kapillaarielektroforeesilla - MPKT 10

    Siren, H; Saerme, T; Kotiaho, T; Hiissa, T; Savolahti, P; Komppa, V [VTT Chemical Technology, Espoo (Finland)

    1999-12-31

    The aim of the study was to set-up an on-line capillary electrophoresis method for determination of anions in process waters of pulp and paper industry with exporting the results to the process control system of the mill. The quantification is important, since it will give information about the possible causes of precipitation. In recent years, the capillary electrophoresis (CE) due to its high separation efficiency has been shown as a method to take into consideration when analyzing chemical species ranging from small inorganic anions to different macromolecules. Many compounds are not easily detected in their native state, why analysis methods must be developed to improve their detection. Especially, small inorganic and organic anions which do not have chromophores are not sensitive enough for direct-UV detection. In such analyses the anions are mostly detected with indirect-UV technique. Capillary electrophoresis instruments are used to analyze samples in off-line, which seldom represent the situation in process. Therefore, on-line instrument technology with autoanalyzing settings will be needed in quality control. The development of a fully automatic capillary electrophoresis system is underway in co-operation with KCL (The Finnish Pulp and Paper Research Institute). In our research, we have first concentrated on the determination of sulphate in waters of paper industry. The method used for detection of sulphate is based on indirect-UV detection with CE, where the background electrolyte (BGE) is an absorbing mixture of secondary amines. The whole procedure for quantification of sulphate is performed within 15 minutes, after which a new sample is analyzed automatically. The only sample pretreatment is filtration, which is necessary before analysis. The concentrations of sulphate in process waters tested were between 300 and 800 ppm. Our tests show that a simultaneous determination of chloride, sulphate, nitrate, nitrite, sulphite, carbonate and oxalate is also

  14. Determination of anions with an on-line capillary electrophoresis method; Anionien on-line maeaeritys kapillaarielektroforeesilla - MPKT 10

    Siren, H.; Saerme, T.; Kotiaho, T.; Hiissa, T.; Savolahti, P.; Komppa, V. [VTT Chemical Technology, Espoo (Finland)

    1998-12-31

    The aim of the study was to set-up an on-line capillary electrophoresis method for determination of anions in process waters of pulp and paper industry with exporting the results to the process control system of the mill. The quantification is important, since it will give information about the possible causes of precipitation. In recent years, the capillary electrophoresis (CE) due to its high separation efficiency has been shown as a method to take into consideration when analyzing chemical species ranging from small inorganic anions to different macromolecules. Many compounds are not easily detected in their native state, why analysis methods must be developed to improve their detection. Especially, small inorganic and organic anions which do not have chromophores are not sensitive enough for direct-UV detection. In such analyses the anions are mostly detected with indirect-UV technique. Capillary electrophoresis instruments are used to analyze samples in off-line, which seldom represent the situation in process. Therefore, on-line instrument technology with autoanalyzing settings will be needed in quality control. The development of a fully automatic capillary electrophoresis system is underway in co-operation with KCL (The Finnish Pulp and Paper Research Institute). In our research, we have first concentrated on the determination of sulphate in waters of paper industry. The method used for detection of sulphate is based on indirect-UV detection with CE, where the background electrolyte (BGE) is an absorbing mixture of secondary amines. The whole procedure for quantification of sulphate is performed within 15 minutes, after which a new sample is analyzed automatically. The only sample pretreatment is filtration, which is necessary before analysis. The concentrations of sulphate in process waters tested were between 300 and 800 ppm. Our tests show that a simultaneous determination of chloride, sulphate, nitrate, nitrite, sulphite, carbonate and oxalate is also

  15. Electric discharge during electrosurgery.

    Shashurin, Alexey; Scott, David; Zhuang, Taisen; Canady, Jerome; Beilis, Isak I; Keidar, Michael

    2015-04-16

    Electric discharge utilized for electrosurgery is studied by means of a recently developed method for the diagnostics of small-size atmospheric plasma objects based on Rayleigh scattering of microwaves on the plasma volume. Evolution of the plasma parameters in the near-electrode sheaths and in the positive column is measured and analyzed. It is found that the electrosurgical system produces a glow discharge of alternating current with strongly contracted positive column with current densities reaching 10(3) A/cm(2). The plasma electron density and electrical conductivities in the channel were found be 10(16) cm(-3) and (1-2) Ohm(-1) cm(-1), respectively. The discharge interrupts every instance when the discharge-driving AC voltage crosses zero and re-ignites again every next half-wave at the moment when the instant voltage exceeds the breakdown threshold.

  16. Vaginal delivery - discharge

    Pregnancy - discharge after vaginal delivery ... You may have bleeding from your vagina for up to 6 weeks. Early on, you may pass some small clots when you first get up. Bleeding will slowly become ...

  17. Prostate radiation - discharge

    ... this page: //medlineplus.gov/ency/patientinstructions/000399.htm Prostate radiation - discharge To use the sharing features on ... keeping or getting an erection may occur after prostate radiation therapy. You may not notice this problem ...

  18. Brain injury - discharge

    ... this page: //medlineplus.gov/ency/patientinstructions/000163.htm Brain injury - discharge To use the sharing features on ... know was in the hospital for a serious brain injury. At home, it will take time for ...

  19. Brain aneurysm repair - discharge

    ... this page: //medlineplus.gov/ency/patientinstructions/000123.htm Brain aneurysm repair - discharge To use the sharing features ... this page, please enable JavaScript. You had a brain aneurysm . An aneurysm is a weak area in ...

  20. Brain radiation - discharge

    Radiation - brain - discharge; Cancer - brain radiation; Lymphoma - brain radiation; Leukemia - brain radiation ... Decadron) while you are getting radiation to the brain. It may make you hungrier, cause leg swelling ...

  1. Atrial fibrillation - discharge

    ... this page: //medlineplus.gov/ency/patientinstructions/000237.htm Atrial fibrillation - discharge To use the sharing features on this ... have been in the hospital because you have atrial fibrillation . This condition occurs when your heart beats faster ...

  2. Pneumonia - adults - discharge

    ... this page: //medlineplus.gov/ency/patientinstructions/000017.htm Pneumonia in adults - discharge To use the sharing features on this page, please enable JavaScript. You have pneumonia, which is an infection in your lungs. In ...

  3. Knee arthroscopy - discharge

    ... page: //medlineplus.gov/ency/patientinstructions/000199.htm Knee arthroscopy - discharge To use the sharing features on this ... surgery to treat problems in your knee (knee arthroscopy). You may have been checked for: Torn meniscus. ...

  4. Cosmetic breast surgery - discharge

    ... this page: //medlineplus.gov/ency/patientinstructions/000273.htm Cosmetic breast surgery - discharge To use the sharing features on this page, please enable JavaScript. You had cosmetic breast surgery to change the size or shape ...

  5. Shoulder surgery - discharge

    ... this page: //medlineplus.gov/ency/patientinstructions/000179.htm Shoulder surgery - discharge To use the sharing features on this page, please enable JavaScript. You had shoulder surgery to repair the tissues inside or around your ...

  6. Recurrent Partial Words

    Francine Blanchet-Sadri

    2011-08-01

    Full Text Available Partial words are sequences over a finite alphabet that may contain wildcard symbols, called holes, which match or are compatible with all letters; partial words without holes are said to be full words (or simply words. Given an infinite partial word w, the number of distinct full words over the alphabet that are compatible with factors of w of length n, called subwords of w, refers to a measure of complexity of infinite partial words so-called subword complexity. This measure is of particular interest because we can construct partial words with subword complexities not achievable by full words. In this paper, we consider the notion of recurrence over infinite partial words, that is, we study whether all of the finite subwords of a given infinite partial word appear infinitely often, and we establish connections between subword complexity and recurrence in this more general framework.

  7. Discharges for lighting

    Stoffels, W W; Nimalasuriya, T; Flikweert, A J; Mulders, H C J

    2007-01-01

    The most common man-made discharge is a lamp. Even though lamps are often considered a mature technology, the discharge physics is often poorly understood. Two recent initiatives discussed here show that plasma research can help to make significant improvements. First we discuss color separation in metal halide lamps, which is a problem that prevents these highly efficient lamps from being used in more applications. Secondly a novel lamp concept is presented that may replace the current mercury based fluorescent lamps

  8. Discharge lamp technologies

    Dakin, J. [GE Lighting, Cleveland, OH (United States)

    1994-12-31

    This talk is an overview of discharge lamp technology commonly employed in general lighting, with emphasis on issues pertinent to lighting for plant growth. Since the audience is primarily from the plant growth community, and this begins the light source part of the program, we will start with a brief description of the discharge lamps. Challenges of economics and of thermal management make lamp efficiency a prime concern in controlled environment agriculture, so we will emphasize science considerations relating to discharge lamp efficiency. We will then look at the spectra and ratings of some representative lighting products, and conclude with a discussion of technological advance. A general overview of discharge lighting technology can be found in the book of Waymouth (1971). A recent review of low pressure lighting discharge science is found in Dakin (1991). The pioneering paper of Reiling (1964) provides a good introduction to metal halide discharges. Particularly relevant to lighting for plant growth, a recent and thorough treatment of high pressure Na lamps is found in the book by deGroot and vanVliet (1986). Broad practical aspects of lighting application are thoroughly covered in the IES Lighting Handbook edited by Kaufman (1984).

  9. Chaos in gas discharges

    Piel, A.

    1993-01-01

    Many gas discharges exhibit natural oscillations which undergo a transition from regular to chaotic behavior by changing an experimental parameter or by applying external modulation. Besides several isolated investigations, two classes of discharge phenomena have been studied in more detail: ionization waves in medium pressure discharges and potential relaxation oscillations in filament cathode discharges at very low pressure. The latter phenomenon will be discussed by comparing experimental results from different discharge arrangements with particle-in-cell simulations and with a model based on the van-der-Pol equation. The filament cathode discharge has two stable modes of operation: the low current anode-glow-mode and the high current temperature-limited-mode, which form the hysteresis curve in the I(U) characteristics. Close to the hysteresis point of the AGM periodic relaxation oscillations occur. The authors demonstrate that the AGM can be understood by ion production in the anode layer, stopping of ions by charge exchange, and trapping in the virtual cathode around the filament. The relaxation oscillations consist of a slow filling phase and a rapid phase that invokes formation of an unstable double-layer, current-spiking, and ion depletion from the cathodic plasma. The relaxation oscillations can be mode-locked by external modulation. Inside a mode-locked state, a period doubling cascade is observed at high modulation degree

  10. Characterization of appendage weld quality by on line monitoring of electrical parameters

    Setty, D.S.; Somani, A.K.; Ram, A.M.; Rao, A.R.; Jayaraj, R.N.; Kalidas, R. [Nuclear Fuel Complex, Dept. of Atomic Energy, Hyderabad (India)

    2005-07-01

    Resistance projection welding of zirconium alloy appendages is one of the most critical processes in the PHWR fuel fabrication. Appendages like Spacers and Bearing pads having multi projections are joined to the fuel sheath using capacitor discharge power source. Variations in the projection sizes, weld parameters and cleanliness of the work pieces have significant effect on the weld quality, in addition to material properties like hardness, tensile strength and surface finish. Defects like metal expulsion and weak welds are occasionally observed in appendage welding process, which need to be identified and segregated. Though numerous off-line inspection methods are available for the weld quality evaluation, on-line monitoring of weld quality is essential for identifying defective welds. For this purpose, various monitoring techniques like acoustic emission, analyzing derived electrical parameters and weld upset/deformation measurements are employed. The derived electrical parameters like A{sup 2}-Sec and Ohm-Sec can also be monitored. The present paper highlights development of suitable acceptance criteria for the monitoring technique by employing derived electrical parameters covering a wide range of weld variables like watt-sec and squeeze force. Excellent correlation could be achieved in identifying the weak welds and weld expulsion defects in mass production. (author)

  11. A novel health indicator for on-line lithium-ion batteries remaining useful life prediction

    Zhou, Yapeng; Huang, Miaohua; Chen, Yupu; Tao, Ye

    2016-07-01

    Prediction of lithium-ion batteries remaining useful life (RUL) plays an important role in an intelligent battery management system. The capacity and internal resistance are often used as the batteries health indicator (HI) for quantifying degradation and predicting RUL. However, on-line measurement of capacity and internal resistance are hardly realizable due to the not fully charged and discharged condition and the extremely expensive cost, respectively. Therefore, there is a great need to find an optional way to deal with this plight. In this work, a novel HI is extracted from the operating parameters of lithium-ion batteries for degradation modeling and RUL prediction. Moreover, Box-Cox transformation is employed to improve HI performance. Then Pearson and Spearman correlation analyses are utilized to evaluate the similarity between real capacity and the estimated capacity derived from the HI. Next, both simple statistical regression technique and optimized relevance vector machine are employed to predict the RUL based on the presented HI. The correlation analyses and prediction results show the efficiency and effectiveness of the proposed HI for battery degradation modeling and RUL prediction.

  12. Investigations on afterglows of neon gas discharges

    Steenhuysen, L.W.G.

    1979-01-01

    Experimental and numerical investigations on afterglows of neon gas discharges are described. The investigated pressure range extends from 0.5 torr to 100 torr; the discharge currents lie between about 1 mA and 100 mA. The decay of the 1s atom densities has been determined experimentally as function of the time elapsed in the afterglow. From the measured decay of metastable 1s 5 atom densities at gas pressure 5 atoms as well as the coefficinets of atomic collisional transfer between the 1s 5 and 1s 4 level are determined. To obtain more insight in the mutual influences of the various loss and production processes of 1s atoms and charge carriers in the afterglow a numerical model has been formed. The behaviour of the afterglow radiation intensity has been measured on discharges with a gas pressure of 1, 10, 20, 50 and 100 torr and a discharge current of 22, 24 and 50 mA. From the results the recombination distribution fractions of the 1s levels are determined and the electron densities at the start of the afterglow of 20, 50 and 100 torr discharges. With the help of the selective excitation spectroscopy the coefficients of atomic transfer between the 2p levels have been measured in the afterglow of discharge with a gas pressure of 1, 10, 20, 50 and 100 torr and a discharge current of 22 mA. From these results and the measured intensities of the various spectral lines in the afterglow the partial recombination coefficients for the 2p levels are calculated. (Auth. )

  13. On-line electrochemical monitoring of microbially influenced corrosion

    Dowling, N.J.E.; Stansbury, E.E.; White, D.C.; Borenstein, S.W.; Danko, J.C.

    1989-01-01

    Newly emerging electrochemical measurement techniques can provide on-line, non-destructive monitoring of the average corrosion rate and indications of localized pitting corrosion together with insight into fundamental electrochemical mechanisms responsible for the corrosion process. This information is relevant to evaluating, monitoring, understanding and controlling microbially influenced corrosion (MIC). MIC of coupons exposed in sidestream devices on site or in laboratory-based experiments, where the corrosion response is accelerated by exposure to active consortia of microbes recovered from specific sites, can be utilized to evaluate mitigation strategies. The average corrosion rates can be determined by small amplitude cyclic voltametry (SACV), and AC impedance spectroscopy (EIS). EIS can also give insight into the mechanisms of the MIC and indications of localized corrosion. Pitting corrosion can be detected non-destructively with open circuit potential monitoring (OCP). OCP also responds to bacterial biofilm activities such as oxygen depletion and other electrochemical activities. Utilizing these methods, accelerated tests can be designed to direct the selection of materials, surface treatments of materials, and welding filler materials, as well as the optimization of chemical and mechanical countermeasures with the microbial consortia recovered and characterized from the specific sites of interest

  14. On-line monitoring of low-level plutonium concentrations

    Hofstetter, K.J.; Huff, G.A.; Rebagay, T.V.

    1979-10-01

    An on-line monitor has been developed to assay plutonium in nitric acid solutions. The performance of the monitor has been assessed by a laboratory experimentation program using solutions with plutonium concentrations from 0.1 to 10 g/l. These conditions are typical of the plutonium solutions in an input stream to a plutonium-purification cycle in a reprocessing plant following uranium/plutonium partitioning. The monitoring system can be fully automated and shows great promise for detecting and quantifying plutonium in situ, thus minimizing the reliance on traditional sampling and laboratory-analysis techniques. The total concentration and isotopic abundance of plutonium are determined by measuring the absolute intensities of the low-energy gamma rays characteristics of 238 Pu, 239 Pu, and 240 Pu nuclides by direct gamma-ray spectroscopy and computer analysis of the spectral data. The addition of a monitoring system of this type to the input stream of a plutonium-purification cycle along with other suitable monitors on the waste streams and on the product stream provides the basis for a near real-time materials control and inventory system. Results of the laboratory-evaluation program employing plutonium in solutions with isotopic compositions typical of those involved in processing light water reactor fuels are presented. The detailed design of a monitoring cell and detection system is given. The precision and accuracy of the results relative to those measured by mass spectrometry and controlled potential coulometry are also summarized

  15. Virtual laboratories: Collaborative environments and facilities-on-line

    Thomas, C.E. Jr. [Oak Ridge National Lab., TN (United States). I and C Div.; Cavallini, J.S.; Seweryniak, G.R.; Kitchens, T.A.; Hitchcock, D.A.; Scott, M.A.; Welch, L.C. [Dept. of Energy, Germantown, MD (United States). Mathematical Information, and Computational Sciences Div.; Aiken, R.J. [Dept. of Energy, Germantown, MD (United States). Mathematical Information, and Computational Sciences Div.]|[Lawrence Livermore National Lab., CA (United States); Stevens, R.L. [Argonne National Lab., IL (United States). Mathematics and Computer Sciences Div.

    1995-07-01

    The Department of Energy (DOE) has major research laboratories in a number of locations in the US, typically co-located with large research instruments or research facilities valued at tens of millions to even billions of dollars. Present budget exigencies facing the entire nation are felt very deeply at DOE, just as elsewhere. Advances over the last few years in networking and computing technologies make virtual collaborative environments and conduct of experiments over the internetwork structure a possibility. The authors believe that development of these collaborative environments and facilities-on-line could lead to a ``virtual laboratory`` with tremendous potential for decreasing the costs of research and increasing the productivity of their capital investment in research facilities. The majority of these cost savings would be due to increased productivity of their research efforts, better utilization of resources and facilities, and avoiding duplication of expensive facilities. A vision of how this might all fit together and a discussion of the infrastructure necessary to enable these developments is presented.

  16. The on-line low temperature nuclear orientation facility NICOLE

    Ohtsubo, T; Roccia, S; Gaulard, C; Stone, N J; Stone, J R; Köster, U; Nikolov, J; Veskovic, M; Simpson, G S

    2017-01-01

    We review major experiments and results obtained by the on-line low temperature nuclear orientation method at the NICOLE facility at ISOLDE, CERN since the year 2000 and highlight their general physical impact. This versatile facility, providing a large degree of controlled nuclear polarization, was used for a long-standing study of magnetic moments at shell closures in the region Z  = 28, N  = 28–50 but also for dedicated studies in the deformed region around A  ∼ 180. Another physics program was conducted to test symmetry in the weak sector and constrain weak coupling beyond V–A . Those two programs were supported by careful measurements of the involved solid state physics parameters to attain the full sensitivity of the technique and provide interesting interdisciplinary results. Future plans for this facility include the challenging idea of measuring the beta–gamma–neutron angular distributions from polarized beta delayed neutron emitters, further test of fundamental symmetries and obtaining nuclear structure data used in medical applications. The facility will also continue to contribute to both the nuclear structure and fundamental symmetry test programs. (paper)

  17. The Westinghouse BEACON on-line core monitoring system

    Buechel, Robert J.; Boyd, William A.; Casadei, Alberto L.

    1995-01-01

    BEACON (Best Estimate Analysis of Core Operations - Nuclear), a core monitoring and operational support package developed by Westinghouse, has been installed at many operating PWRs worldwide. The BEACON system is a real-time monitoring system which can be used in plants with both fixed and movable incore detector systems and utilizes an on-line nodal model combined with core instrumentation data to provide continuous core power distribution monitoring. In addition, accurate core-predictive capabilities utilizing a full core nodal model updated according to plant operating history can be made to provide operational support. Core history information is kept and displayed to help operators anticipate core behavior and take pro-active control actions. The BEACON system has been licensed by the U.S. Nuclear Regulatory Commission for direct, continuous monitoring of DNBR and peak linear heat rate. This allows BEACON to be integrated into the plant technical specifications to permit significant relaxation of operating limitations defined by conventional technical specifications. (author). 4 refs, 2 figs, 1 tab

  18. Development of an On-Line Uranium Enrichment Monitor

    Xuesheng, L.; Guorong, L.; Yonggang, Z.; Xueyuan, H. X.-Y.

    2015-01-01

    An on-line enrichment monitor was developed to measure the enrichment of UF6 flowing through the processing pipes in centrifuge uranium enrichment plant. A NaI(Tl) detector was used to measure the count rates of the 186 keV gamma ray emitted from 235U, and the total quantity of uranium was determined from thermodynamic characteristics of gaseous uranium hexafluoride. The results show that the maximum relative standard deviation is less than 1% when the measurement time is 120 s or more and the pressure is more than 2 kPa in the measurement chamber. There are two working models for the monitor. The monitor works normally in the continuous model, When the gas's pressure in the pipe fluctuates greatly, it can work in the intermittent model, and the measurement result is very well. The background of the monitor can be measured automatically periodically. It can control automatically electromagnetic valves open and close, so as to change the gas's quantity in the chamber. It is a kind of unattended and remote monitor, all of data can be transfer to central control room. It should be effective for nuclear materials accountability verifications and materials balance verification at uranium enrichment plant by using the monitor to monitor Uranium enrichment of gaseous uranium hexafluoride in the output end of cascade continuously. (author)

  19. On-line mass separator of superheavy atoms

    Oganesyan, Yu.Ts.

    2002-01-01

    The concept is presented of an on-line Mass Analyzer of SuperHeavy Atoms (MASHA) dedicated to the separation and determination of the mass and decay properties of new elements and isotopes produced in heavy-ion induced reactions. The new nuclides with half-lives T 1/2 ≥ 1 s are transported to an ECR-source working at a frequency of 2.45 GHz and are separated by mass with a mass resolution of M/ΔM ∼ 1500. In the focal plane of the magnetic analyzer a front strip detector surrounded by side detectors will be placed to determine the mass according to the signals from the detected α-particles or fission fragments with efficiency of about 90 %. In comparison to other existing in-flight recoil separators, the present setup will be characterized by higher efficiency and high selectivity relative to background reaction products. The setup MASHA may be used also in the investigation of nuclear reactions of different type induced by stable and radioactive beams

  20. On-Line Mass Separator of Superheavy Atoms

    Oganessian, Yu T

    2002-01-01

    The concept is presented of an on-line Mass Analyzer of SuperHeavy Atoms (MASHA) dedicated to the separation and determination of the mass and decay properties of new elements and isotopes produced in heavy-ion induced reactions. The new nuclides with half-lives T_{1/2}\\ge 1 s are transported to an ECR-source working at a frequency of 2.45 GHz and are separated by mass with a mass resolution of M/\\Delta M\\sim 1500. In the focal plane of the magnetic analyzer a front strip detector surrounded by side detectors will be placed to determine the mass according to the signals from the detected alpha-particles or fission fragments with efficiency of about 90 %. In comparison to other existing in-flight recoil separators, the present setup will be characterized by higher efficiency and high selectivity relative to background reaction products. The setup MASHA may be used also in the investigation of nuclear reactions of different type induced by stable and radioactive beams.

  1. Optimization of an on-line function generation

    Versteele, C

    1977-01-01

    A particular example of process control is the analog function generator of the CERN proton synchrotron. For magnet field correction, some magnets have to follow reference currents synchronous with the pulses of the synchrotron. Depending on the dynamic behaviour of the magnet system to be controlled, the output current will show a somewhat distorted image of the reference current used as input. An on-line computer strategy has been designed to compensate the distortions: i.e. to adjust the input function at successive pulses in such a way that the output current follows the reference as closely as required. However, the identification of such a system is not carried out because it is difficult and singular in any case. Modifications cannot be computed directly, but will result from an iterative strategy: the closed-loop adaptive control is based on a maximization procedure, requiring little memory and no gradient information. The algorithm is a variant of the optimization method called extended sequential se...

  2. On-line monitoring of methane in sewer air.

    Liu, Yiwen; Sharma, Keshab R; Murthy, Sudhir; Johnson, Ian; Evans, Ted; Yuan, Zhiguo

    2014-10-16

    Methane is a highly potent greenhouse gas and contributes significantly to climate change. Recent studies have shown significant methane production in sewers. The studies conducted so far have relied on manual sampling followed by off-line laboratory-based chromatography analysis. These methods are labor-intensive when measuring methane emissions from a large number of sewers, and do not capture the dynamic variations in methane production. In this study, we investigated the suitability of infrared spectroscopy-based on-line methane sensors for measuring methane in humid and condensing sewer air. Two such sensors were comprehensively tested in the laboratory. Both sensors displayed high linearity (R(2) > 0.999), with a detection limit of 0.023% and 0.110% by volume, respectively. Both sensors were robust against ambient temperature variations in the range of 5 to 35°C. While one sensor was robust against humidity variations, the other was found to be significantly affected by humidity. However, the problem was solved by equipping the sensor with a heating unit to increase the sensor surface temperature to 35°C. Field studies at three sites confirmed the performance and accuracy of the sensors when applied to actual sewer conditions, and revealed substantial and highly dynamic methane concentrations in sewer air.

  3. Performing maintenance activities on-line a risk perspective

    Darling, S.S.; Mairs, T.P.

    1993-01-01

    The US nuclear power industry is attempting to deal with the issue of optimizing the performance of maintenance activities with the advent of the maintenance rule. The impact of any maintenance activity on the safe operation of a nuclear power facility can be quantified on the basis of risk. Therefore, it is incumbent upon the industry to accommodate the regulator and present a maintenance optimization program in terms that explicitly address the potential risk inherent in its concept and implementation. The motivation for utilities to perform maintenance while the plant is operating (i.e., on-line) is readily perceived to offer the following advantages: 1. greater system availability; 2. higher plant capacity factor; 3. more evenly distributed workload for the maintenance department; and 4. overall safer plant operation. However, risks inherent in undertaking maintenance activities during power operation could amount to the realization that reapportionment of these tasks is not cost-beneficial. Therefore, it is important that any utility considering implementing such a paradigm in maintenance philosophy establish a rigorous process to select, perform, and monitor maintenance tasks performed while operating

  4. On-line nuclear analysis of coal (Nucoalyzer)

    Brown, D.R.; Gozani, T.; Bozorgmanesh, H.

    1980-01-01

    Control of quality in the coal process stream is increasingly important in both coal preparation facilities and coal fire power plants. Traditional wet chemistry methods of monitoring coal composition are incapable of providing anything approaching real-time analysis of coal. Typically, small samples of the coal stream are laboratory analyzed and the results made available between a day to a week later. By this time the coal is through the process stream, often already burned and no control is possible. The need of real-time analysis of bulk quantities of the coal has long been recognized and this need motivated Science Applications, Inc. to develop, since 1975, a continuous on-line nuclear analyzer of coal (or CONAC). Over the last three years a prototype of this instrument has undergone extensive testing using 200 pound bulk samples of a wide variety of US coal types. The Nucoalyzer has proven capable of measuring the abundances of all the important elemental constituents of coal along with the ash and calorific value. In the past year the first instrument has been installed and undergone testing at Detroit Edison's Monroe Coal blending facility, where it will control the blending of high and low sulfur coal to meet EPA emission regulations

  5. An on-line tritium-in-water monitor

    Singh, A.N.; Ratnakaran, M.; Vohra, K.G.

    1985-01-01

    The paper describes the development and operation of a continuous on-line tritium-in-water monitor for the detection of heavy water leaks into the secondary coolant light water of a heavy water power reactor. The heart of the instrument is its plastic scintillator sponge detector, made from 5 μm thick plastic scintillator films. The sponge weighs only about 1 g and is in the form of disc of 48 mm diameter and 8 mm thickness. The total surface area of the films is about 3000 cm 2 . In the coincidence mode of counting, the detector gives 1000 cps for the passage of 3.7 x 10 4 Bq/cm 3 (1 μCi/cm 3 ) of tritiated water. The background in 6 cm thick lead shielding in the laboratory is 0.2 cps, and inside the reactor building it is below 1 cps. The monitor presently scans 18 sample lines in sequence for 5 min each and gives a printout for the activity in each line. (orig.)

  6. An on-line tritium-in-water monitor

    Singh, A. N.; Ratnakaran, M.; Vohra, K. G.

    1985-05-01

    The paper describes the development and operation of a continuous on-line tritium-in-water monitor for the detection of heavy water leaks into the secondary coolant light water of a heavy water power reactor. The heart of the instrument is its plastic scintillator sponge detector, made from 5 μm thick plastic scintillator films. The sponge weighs only about 1 g and is in the form of disc of 48 mm diameter and 8 mm thickness. The total surface area of the films is about 3000 cm 2. In the coincidence mode of counting, the detector gives 1000 cps for the passage of 3.7 × 10 4 Bq/cm 3 (1 μCi/cm 3) of tritiated water. The background in 6 cm thick lead shielding in the laboratory is 0.2 cps, and inside the reactor building it is below 1 cps. The monitor presently scans 18 sample lines in sequence for 5 min each and gives a printout for the activity in each line.

  7. Knowledge-based on-line vibration monitoring diagnose

    Johansson, L.G.; Karlsson, A.; Noeremark, A.

    1990-01-01

    ABB STAL developed some years ago a knowledge-based on-line vibration analysis system (working-name KOVA). KOVA is intended to work together with some type of vibration monitoring system, at present it is adapted to TVM 300. KOVA has no controlling function. It will only diagnose the actual situation and give the user explanations and proposals for actions to be taken. During the developing work, great experience has been gained of the features this type of system demands. This paper will present the outlines of the application and also discuss how to make diagnoses based both on general rules as well as on historical vibration cases for that particular unit (or identical units9. Another subject that this paper will outline, is the representation and evaluation of knowledge. KOVA serves as a decision-support system for the operator. Since KOVA will often give the operator more than one possible diagnosis as the cause of a fault, it is of great importance to give the operator comprehensive explanations and as many facts as possible. It is also important to rank the suggested diagnoses in some way. In KOVA these demands are effectively supported. The models and tools used to realize this functionality will be described in this paper

  8. On-line monitoring of lithium carbonate dissolution

    Sun, Yuzhu; Song, Xingfu; Wang, Jin; Luo, Yan; Yu, Jianguo [National Engineering Research Center for Integrated Utilization Salt Lake Resources, East China University of Science and Technology, Shanghai (China)

    2009-11-15

    Dissolution of lithium carbonate (Li{sub 2}CO{sub 3}) in aqueous solution was investigated using three on-line apparatuses: the concentration of Li{sub 2}CO{sub 3} was measured by electrical conductivity equipment; CLD (Chord Length Distribution) was monitored by FBRM (Focused Beam Reflectance Measurement); crystal image was observed by PVM (Particle Video Microscope). Results show dissolution rate goes up with a decrease of particle size, and with an increase in temperature; stirring speed causes little impact on dissolution; ultrasound facilitates dissolution obviously. The CLD evolution and crystal images of Li{sub 2}CO{sub 3}powders in stirred fluid were observed detailedly by FBRM and PVM during dissolution. Experimental data were fitted to Avrami model, through which the activation energy was found to be 34.35 kJ/mol. PBE (Population Balance Equation) and moment transform were introduced to calculate dissolution kinetics, obtaining correlation equations of particle size decreasing rate as a function of temperature and undersaturation. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  9. Building collaboration tools and access to on-line facilities

    Agarwal, D.; Sachs, S.

    1996-11-01

    Network-based facilities will allow researchers at different locations to collaborate on experiments as if they all were together in the same laboratory. The expected value of these geographically distributed environments includes substantially increased effectiveness in doing science, and an enabling capability for analytical and high-value production use by industry. The Distributed, Collaboratory Experiment Environments (DCEE) Program consists of four projects that were established to build prototype remote experiment and collaborative environments. The work undertaken in this project represents some of the research and development of the mechanisms and infrastructure required to make collaboratories a reality. Some of these mechanisms have already been developed. Several other mechanisms, such as data dissemination, resource management for the sharing of experiment control, safety and security, electronic notebooks, elements of telepresence, and integrated user interfaces need further research and development. The pilot application for these collaborative tools is the Advanced Light Source (ALS) Beamline 7.0 at the Ernest Orlando Lawrence Berkeley Laboratory. The ALS is a particle accelerator and is a source of very high brilliance soft X-ray beams. One experimental facility is the Spectro-Microscopy Facility Beamline 7.0. Through this project, the Spectro-Microscopy Facility will be opened up to users from a wide range of organizations. The goal is to build software that will not only put the ALS Beamline 7.0 on-line, but will also serve as building blocks for future collaboratory development

  10. EXPANDING ACADEMIC VOCABULARY WITH AN INTERACTIVE ON-LINE DATABASE

    Marlise Horst

    2005-05-01

    Full Text Available University students used a set of existing and purpose-built on-line tools for vocabulary learning in an experimental ESL course. The resources included concordance, dictionary, cloze-builder, hypertext, and a database with interactive self-quizzing feature (all freely available at www.lextutor.ca. The vocabulary targeted for learning consisted of (a Coxhead's (2000 Academic Word List, a list of items that occur frequently in university textbooks, and (b unfamiliar words students had met in academic texts and selected for entry into the class database. The suite of tools were designed to foster retention by engaging learners in deep processing, an aspect that is often described as missing in computer exercises for vocabulary learning. Database entries were examined to determine whether context sentences supported word meanings adequately and whether entered words reflected the unavailability of cognates in the various first languages of the participants. Pre- and post-treatment performance on tests of knowledge of words targeted for learning in the course were compared to establish learning gains. Regression analyses investigated connections between use of specific computer tools and gains.

  11. Design considerations for on-line vibration diagnostic systems

    Branagan, L.A.; Schjeibel, J.R.

    1989-01-01

    The decisions made in the design of a data system for on-line vibration diagnostic system in power plants define how well the system will meet its intended goals. Direct use of the data for performing troubleshooting or developing operating correlations requires an understanding of the subtle impact of the design decisions incorporated in the data system. A data system includes data acquisition, data storage, and data retrieval. Data acquisition includes the selection of sensors, of vibration measurement modes, and of the time stamping format, and the arrangement of data collection cycles. Data storage requires the evaluation of data compression options and of data segregation. Data retrieval design requires an understanding of the data storage and acquisition techniques. Each of these options and design decisions involves compromises, many of which are discussed in this paper. Actual and synthetic data are presented to illustrate these points. The authors' experience with multiple data collection cycles, with frequent monitoring, and with storage by exception suggests that these techniques can be developed into an effective diagnostic system

  12. Study of the on line radioactive multicharged ion production

    Lecesne, N.

    1997-01-01

    This work is directly related to the SPIRAL project (Systeme de Production d'Ions Radioactifs Acceleres en Ligne) which will start at GANIL at the end of 1998. The aim of the thesis was to study the on line radioactive multicharged ion beam production stages, i.e. the production and diffusion of the radioactive nuclei in a thick target, their possible transfer up to an ECR ion source and their ionisation. Production cross sections of radioactive neutron rich nuclei, formed by fragmentation of a heavy ion beam in a thick target, were measured. An external target-ECR source system, dedicated to the radioactive noble gases production, and two internal target-ECR source systems, dedicated to the radioactive condensable element production, were built and tested on the SIRa tests bench (Separateur d'Ions Radioactifs). Different detection configurations were elaborated in order to identify the radioactive nuclei and estimate their production yields. Finally, a new method for measuring the overall efficiency of the separator was developed and allowed to study the diffusion properties of radioactive noble gases in various targets. (author)

  13. On-line confidence monitoring during decision making.

    Dotan, Dror; Meyniel, Florent; Dehaene, Stanislas

    2018-02-01

    Humans can readily assess their degree of confidence in their decisions. Two models of confidence computation have been proposed: post hoc computation using post-decision variables and heuristics, versus online computation using continuous assessment of evidence throughout the decision-making process. Here, we arbitrate between these theories by continuously monitoring finger movements during a manual sequential decision-making task. Analysis of finger kinematics indicated that subjects kept separate online records of evidence and confidence: finger deviation continuously reflected the ongoing accumulation of evidence, whereas finger speed continuously reflected the momentary degree of confidence. Furthermore, end-of-trial finger speed predicted the post-decisional subjective confidence rating. These data indicate that confidence is computed on-line, throughout the decision process. Speed-confidence correlations were previously interpreted as a post-decision heuristics, whereby slow decisions decrease subjective confidence, but our results suggest an adaptive mechanism that involves the opposite causality: by slowing down when unconfident, participants gain time to improve their decisions. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. 3081/E processor and its on-line use

    Rankin, P.; Bricaud, B.; Gravina, M.

    1985-05-01

    The 3081/E is a second generation emulator of a mainframe IBM. One of it's applications will be to form part of the data acquisition system of the upgraded Mark II detector for data taking at the SLAC linear collider. Since the processor does not have direct connections to I/O devices a FASTBUS interface will be provided to allow communication with both SLAC Scanner Processors (which are responsible for the accumulation of data at a crate level) and the experiment's VAX 8600 mainframe. The 3081/E's will supply a significant amount of on-line computing power to the experiment (a single 3081/E is equivalent to 4 to 5 VAX 11/780's). A major advantage of the 3081/E is that program development can be done on an IBM mainframe (such as the one used for off-line analysis) which gives the programmer access to a full range of debugging tools. The processor's performance can be continually monitored by comparison of the results obtained using it to those given when the same program is run on an IBM computer. 9 refs

  15. Gated Treatment Delivery Verification With On-Line Megavoltage Fluoroscopy

    Tai An; Christensen, James D.; Gore, Elizabeth; Khamene, Ali; Boettger, Thomas; Li, X. Allen

    2010-01-01

    Purpose: To develop and clinically demonstrate the use of on-line real-time megavoltage (MV) fluoroscopy for gated treatment delivery verification. Methods and Materials: Megavoltage fluoroscopy (MVF) image sequences were acquired using a flat panel equipped for MV cone-beam CT in synchrony with the respiratory signal obtained from the Anzai gating device. The MVF images can be obtained immediately before or during gated treatment delivery. A prototype software tool (named RTReg4D) was developed to register MVF images with phase-sequenced digitally reconstructed radiograph images generated from the treatment planning system based on four-dimensional CT. The image registration can be used to reposition the patient before or during treatment delivery. To demonstrate the reliability and clinical usefulness, the system was first tested using a thoracic phantom and then prospectively in actual patient treatments under an institutional review board-approved protocol. Results: The quality of the MVF images for lung tumors is adequate for image registration with phase-sequenced digitally reconstructed radiographs. The MVF was found to be useful for monitoring inter- and intrafractional variations of tumor positions. With the planning target volume contour displayed on the MVF images, the system can verify whether the moving target stays within the planning target volume margin during gated delivery. Conclusions: The use of MVF images was found to be clinically effective in detecting discrepancies in tumor location before and during respiration-gated treatment delivery. The tools and process developed can be useful for gated treatment delivery verification.

  16. Application of on-line near-infrared analyzer to process control in fermentation plant; Hakko plant no unten kanri ni okeru kinsekigai bunsekikei no tekiyo

    OKayasu, S.; Kitayama, M.; Miyashiro, S. [Ajinomoto Co. Inc. Tokyo (Japan)

    1995-09-10

    Aiming for stable operation and rationalization of a fermentation plant, a near-infrared analyzer was introduced into the on-line analyzing system of the fermentation process. An on-line sampling system with a deforming apparatus was applied to a fermenter in a commercial scale plant. A new efficient method for obtaining highly accurate calibration curves of the near-infrared analyzer was presented. The established method for on-line determination of the main components in the fermentation medium for amino acid production was applied to a real-time measurement system in a commercial fermentation plant. The pattern of sugar concentration change was successfully obtained on a real-time basis. The system was partially incorporated into operation control, even if there was room for improvement of analytical accuracy in response to raw material differences in each lot. 9 refs., 4 figs., 3 tabs.

  17. Using Reading Guides and On-Line Quizzes to Improve Reading Compliance and Quiz Scores

    Maurer, Trent W.; Longfield, Judith

    2015-01-01

    This study compared students' daily in-class reading quiz scores in an introductory Child Development course across five conditions: control, reading guide only, reading guide and on-line practice quiz, reading guide and on-line graded quiz, and reading guide and both types of on-line quizzes. At the beginning of class, students completed a 5-item…

  18. On-line Versus Face-to-Face Education: Utilizing Technology to Increase Effectiveness

    2012-05-17

    Andragogy and learner-centered education provided in on-line education present excellent results. Secondly, the cost of on-line education compared to...13 Pedagogy versus Andragogy ...achieving learning outcomes. However, Andragogy and learner centered education provided in on-line education presents excellent results. Secondly, the cost

  19. Discharge characteristics in inhomogeneous fields under air flow

    Vogel, Stephan; Holbøll, Joachim

    2017-01-01

    the frequency and magnitude of partial discharges in the vicinity of the electrode due to an increased rate of space charge removal around the tip of the needle and in the gap. The positive polarity shows higher dependency on air flow compared to the negative polarity. It is shown that positive breakdown......This research investigates the impact of high velocity air flow on Partial Discharge (PD) patterns generated in strongly inhomogeneous fields. In the laboratory, a needle plane electrode configuration was exposed to a high electrical DC-field and a laminar air flow up to 22 ms. The needle...

  20. The effect of family therapy on the changes in the severity of on-line game play and brain activity in adolescents with on-line game addiction

    Han, Doug Hyun; Kim, Sun Mi; Lee, Young Sik; Renshaw, Perry F.

    2015-01-01

    We evaluated whether a brief 3-week family therapy intervention would change patterns of brain activation in response to affection and gaming cues in adolescents from dysfunctional families who met criteria for on-line game addiction. Fifteen adolescents with on-line game addiction and fifteen adolescents without problematic on-line game play and an intact family structure were recruited. Over 3 weeks, families were asked to carry out homework assignments focused on increasing family cohesion for more than 1 hour/day and 4 days/week. Before therapy, adolescents with on-line game addiction demonstrated decreased activity as measured by functional magnetic resonance imaging (fMRI) within the caudate, middle temporal gyrus, and occipital lobe in response to images depicting parental affection and increased activity of the middle frontal and inferior parietal in response scenes from on-line games, relative to healthy comparison subjects. Improvement in perceived family cohesion following 3 weeks of treatment was associated with an increase in the activity of the caudate nucleus in response to affection stimuli and was inversely correlated with changes in on-line game playing time. With evidence of brain activation changes in response to on-line game playing cues and images depicting parental love, the present findings suggest that family cohesion may be an important factor in the treatment of problematic on-line game playing. PMID:22698763

  1. In situ microscopy for on-line determination of biomass.

    Bittner, C; Wehnert, G; Scheper, T

    1998-10-05

    A sensor is presented, which allows on-line microscopic observation of microorganisms during fermentations in bioreactors. This sensor, an In Situ Microscope (ISM) consists of a direct-light microscope with a measuring chamber, integrated in a 25 mm stainless steel tube, two CCD-cameras, and two frame-grabbers. The data obtained are processed by an automatic image analysis system. The ISM is connected with the bioreactor via a standard port, and it is immersed directly in the culture liquid-in our case Saccharomyces cerevisiae in a synthetic medium. The microscopic examination of the liquid is performed in the measuring chamber, which is situated near the front end of the sensor head. The measuring chamber is opened and closed periodically. In the open state, the liquid in the bioreactor flows unrestricted through the chamber. In closing, a defined volume of 2,2. 10(-8) mL of the liquid becomes enclosed. After a few seconds, when the movement of the cells in the enclosed culture has stopped, they are examined with the microscope. The microscopic images of the cells are registered with the CCD-cameras and are visualized on a monitor, allowing a direct view of the cell population. After detection, the measuring chamber reopens, and the enclosed liquid is released. The images obtained are evaluated as to cell concentration, cell size, cell volume, biomass, and other relevant parameters simultaneously by automatic image analysis. With a PC (486/33 MHz), image processing takes about 15 s per image. The detection range tested when measuring cells of S. cerevisiae is about 10(6) to 10(9) cells/mL (equivalent to a biomass of 0.01 g/L to 12 g/L). The calculated biomass values correlate very well with those obtained using dry weight analysis. Furthermore, histograms can be calculated, which are comparable to those obtained by flow cytometry. Copyright 1998 John Wiley & Sons, Inc.

  2. On-line sensor technology for food manufacturing industry. Shokuhin bun prime ya ni okeru on-line sensor gijutsu

    Komiya, K. (Ajinomoto Co. Inc., Tokyo (Japan))

    1990-08-05

    This paper introduced the sensor technology for food manufacturing industry. If sugar concentration in main raw material is too high in the amino acid fermentation, control of the concentration is required because fungi growth is inhibited. A controlling method for sugar concentration was developed by using the correlation between consumption of NH {sub 3} for pH adjustment and sugar consumption in place of conventional analyzing method and was introduced in the gulutamic acid fermantation. BOD sensor was developed to enable the selective measurement of organic substances which can be processed by organisms, and measuring time was shortened from previous five days to 30 minutes. Since many organics absorb infrared ray, near infrared analysis is suitable for food analysis and on-line analysis has high possibility. When this method is applied to measure moisture in fishes and meats, continuous measurement can be made nondestructively and without contacting, and further the precision is {plus minus} 0.1%. Simultaneous multi-composition analyses are carried out by continuous spectrum and near infrared method using higher rate scanning. Sensor development for taste and smell has started. 10 refs., 4 figs., 4 refs.

  3. On line photochemically induced excitation-emission-kinetic four-way data

    Jimenez Giron, A.; Duran-Meras, I.; Espinosa-Mansilla, A.; Munoz de la Pena, A.; Canada Canada, F.; Olivieri, A.C.

    2008-01-01

    The determination of folic acid and its two main serum metabolites, 5-methyltetrahydrofolic acid and tetrahydrofolic acid, has been accomplished using four-way data modelled by the third-order multivariate calibration methods unfolded and N-dimensional partial least-squares (U-PLS and N-PLS), in combination with the separate procedure known as residual trilinearization (RTL). The four-way data were acquired by following the photochemical reaction of these compounds by on line irradiation with a UV lamp. The excitation-emission matrices (EEMs) were recorded as a function of the irradiation time, using a fast scanning spectrofluorimeter. The method achieves selectivity from the different rates at which the corresponding photoproducts of the folic acid derivatives are formed and degraded. Several N-dimensional chemometric algorithms were used and the method was applied to the determination of these compounds in serum samples. The best algorithms to perform the multivariate calibration were U-PLS and N-PLS in combination with the separate residual trilinearization procedure, achieving the second-order advantage. The approach allows minimizing or eliminating traditionally time-consuming sample pre-treatments and can facilitate quantifying an analyte in its native environment

  4. On-line dynamic monitoring automotive exhausts: using BP-ANN for distinguishing multi-components

    Zhao, Yudi; Wei, Ruyi; Liu, Xuebin

    2017-10-01

    Remote sensing-Fourier Transform infrared spectroscopy (RS-FTIR) is one of the most important technologies in atmospheric pollutant monitoring. It is very appropriate for on-line dynamic remote sensing monitoring of air pollutants, especially for the automotive exhausts. However, their absorption spectra are often seriously overlapped in the atmospheric infrared window bands, i.e. MWIR (3 5μm). Artificial Neural Network (ANN) is an algorithm based on the theory of the biological neural network, which simplifies the partial differential equation with complex construction. For its preferable performance in nonlinear mapping and fitting, in this paper we utilize Back Propagation-Artificial Neural Network (BP-ANN) to quantitatively analyze the concentrations of four typical industrial automotive exhausts, including CO, NO, NO2 and SO2. We extracted the original data of these automotive exhausts from the HITRAN database, most of which virtually overlapped, and established a mixed multi-component simulation environment. Based on Beer-Lambert Law, concentrations can be retrieved from the absorbance of spectra. Parameters including learning rate, momentum factor, the number of hidden nodes and iterations were obtained when the BP network was trained with 80 groups of input data. By improving these parameters, the network can be optimized to produce necessarily higher precision for the retrieved concentrations. This BP-ANN method proves to be an effective and promising algorithm on dealing with multi-components analysis of automotive exhausts.

  5. SUPPORTTING REGULAR AND ON-LINE BIOCHEMISTRY CLASSES USING INTERACTIVE LEARNING

    F.C. Dórea

    2004-05-01

    Full Text Available Interactive learning on the Web may be a way to partially supplement the classroom learning ex-perience by providing an interactive environment similar to the classroom but with more attentionto individual student needs. New computational resources are available every day, and these newtechnologies that help the understanding process can be popularized by free full access web sites, asBiochemical View. This site, available at http://www.unb.br/cbsp/bioq, was developed at Universityof Braslia (UnB to support Biochemistry classes of this and any other Universities, since its alsoavailable in an English version. The contents - that include the usual metabolic pathways referentto the metabolism of carbohydrates, amino acids, lipids and nucleic acids - are presented in bi andthree-dimensional formats, easily accessible and assimilable, complemented with objective texts anddescription of regulation points. Protocols for experimental classes, reference materials, and specicinformation about each molecule of all pathways are also available, including metabolic participationschemes of them. An evaluation form of the site is available on-line, developed using PHP. Besidesthe positives results, the suggestions collected in these evaluations since 2001 have been guiding theactualizations. So, the site is the result of students opinions and needs.

  6. Multipactor discharge apparatus

    1976-01-01

    The invention deals with a multipactor discharge apparatus which can be used for tuning microwave organs such as magnetron oscillators and other cavity resonators. This apparatus is suitable for delivering an improved tuning effect in a resonation organ wherefrom the working frequency must be set. This apparatus is equipped with two multipactor discharge electrodes set in a configuration such to that a net current flows from one electrode to another. These electrodes are parallel and flat. The apparatus can be used in magnetron devices as well for continuous waves as for impulses

  7. Red herring vaginal discharge.

    Lee, Jun Hee; Pringle, Kirsty; Rajimwale, Ashok

    2013-09-18

    Labial hair tourniquet syndrome is a rare condition that can be easily misdiagnosed and ultimately lead to irreversible damage. An 11-year-old premenarche girl presented with a 5-day history of pain and swelling in the labia with associated vaginal discharge. The general practitioner treated her with clotrimazole without improvement. On examination, there was an oedematous swelling of the right labia with a proximal hair tourniquet. Local anaesthetic was applied and the hair removed with forceps. There was instant relief of pain and the discharge stopped within 24 h. The patient was sent home with a course of antibiotics.

  8. Application on-line imagery for photogrammetry comparison of natural hazards events

    Voumard, Jérémie; Jaboyedoff, Michel; Derron, Marc-Henri

    2015-04-01

    The airborne (ALS) and terrestrial laser scanner (TLS) technologies are well known and actually one of the most common technics to obtain 3D terrain models. However those technologies are expensive and logistically demanding. Another way to obtain DEM without those inconveniences is photogrammetry, in particular the structure from motion (SfM) technic that allows high quality 3D model extraction from common digital camera images without need of a expensive material. If the usual way to get images for SfM 3D modelling is to take pictures on-site, on-line imagery offer the possibility to get images from many roads and other places. The most common on-line street view resource is Google Street View. Since April 2014, this service proposes a back-in-time function on a certain number of locations. Google Street View images are composed from many pictures taken with a set of panoramic cameras mounted on a platform like a car roof. Those images are affected by strong deformations, which are not recommended for photogrammetry. At first sight, using street view images to make photogrammetry may bring some processing problems. The aim of this project is to study the possibility to made SfM 3D model from Google Street View images with open source processing software (Visual SFM) and low-cost software (Agisoft). The main interest of this method is to evaluate at low cost changes without terrain visit. Study areas are landslides (such those of Séchilienne in France) and cliffs near or far away from roads. Human-made terrain changes like stone wall collapse by high rain precipitations near of Monaco are also studied. For each case, 50 to 200 pictures have been used. The mains conditions to obtain 3D model results are: to have a street view image of the area of interest. Some countries like USA or France are well documented. Other countries like Switzerland are only partially or not at all like Germany. The second constraint is to have two or more sets of images at different

  9. Travelling-wave-sustained discharges

    Schlueter, Hans; Shivarova, Antonia

    2007-01-01

    This review is on discharges maintained by travelling waves: new plasma sources, discovered in 1974 and considered as a prototype of the gas discharges according to their definition as nonlinear systems which unify in a self-consistent manner plasmas and fields. In the presentation here of the fluid-plasma models of the diffusion-controlled regime of the travelling-wave-sustained discharges (TWSDs), the basic features of the discharge maintenance-the discharge self-consistency and the electron heating in the high-frequency field-are stressed. Operation of stationary and pulsed discharges, discharge maintenance without and in external magnetic fields as well as discharge production in different gases (argon, helium, helium-argon gas mixtures and hydrogen) are covered. Modulation instability of diffusion-controlled discharges and discharge filamentation at higher gas pressures are also included in the review. Experimental findings which motivate aspects of the reported modelling are pointed out

  10. Isotopic nuclear reactor with on-line separation

    Liviu, Popa-Simil

    2007-01-01

    In the new reactor-waste cycle design the nuclear reactor gets features of the living beings - resembling the plants/vegetation -. The separation of waste starts inside the fuel by using the fission reaction to separate the fission products from the fuel. The fuel, which is preferred to be highly isotopic enriched, is fabricated in beads smaller than the fission product range, immersed in a gentle flowing liquid drain. If this liquid is Lead Bismuth (LBE) the fission products will be lighter, while in Sodium-Potassium (NaK) will be heavier, except for gases. This drain liquid will collect both the fission products and the collision damage, drawing them slow to give time to short lives disintegration chains to take place inside the shielded nuclear reactor area outside the reactor core in a separation unit. While the drain liquid with the fission products is outside the reactor core few choices are available: - To solidify the drain liquid freezing all elements inside and transport the metal in cryogenic conditions to a remote separation unit, or to apply a separation partitioning process online stabilizing and packing the fission products only, or a combination of these two. The radioactivity of this drain liquid is smaller than that of the actual used fuel because it represents the accumulation of a very short period (about 1 month or less) and had enough time to cool down all the short lives. The separation unit on-line with the nuclear reactor is composed of a density separation unit, followed by a phase interface concentration unit which moves out of the LBE the fission products as lighter impurities, and an electrochemical separation unit for the fission products. Further, chemical separation, stabilization processes are applied and the fission products are delivered partitioned on groups of chemical compatible products. Finally the specific waste is about 1 Kg/Gw*day, to which the stabilization products have to be added which increases this mass by 10 times

  11. Discharges from nuclear power stations

    1991-02-01

    HM Inspectorate of Pollution commissioned, with authorising responsibilities in England and Wales, a study into the discharges of radioactive effluents from Nuclear Power Stations. The study considered arisings from nuclear power stations in Europe and the USA and the technologies to treat and control the radioactive discharges. This report contains details of the technologies used at many nuclear power stations to treat and control radioactive discharges and gives, where information was available, details of discharges and authorised discharge limits. (author)

  12. Synergetic mechanism of methanol–steam reforming reaction in a catalytic reactor with electric discharges

    Kim, Taegyu; Jo, Sungkwon; Song, Young-Hoon; Lee, Dae Hoon

    2014-01-01

    Highlights: • Methanol–steam reforming was performed on Cu catalysts under an electric discharge. • Discharge had a synergetic effect on the catalytic reaction for methanol conversion. • Discharge lowered the temperature for catalyst activation or light off. • Discharge controlled the yield and selectivity of species in a reforming process. • Adsorption triggered by a discharge was a possible mechanism for a synergetic effect. - Abstract: Methanol–steam reforming was performed on Cu/ZnO/Al 2 O 3 catalysts under an electric discharge. The discharge occurred between the electrodes where the catalysts were packed. The electric discharge was characterized by the discharge voltage and electric power to generate the discharge. The existence of a discharge had a synergetic effect on the catalytic reaction for methanol conversion. The electric discharge provided modified reaction paths resulting in a lower temperature for catalyst activation or light off. The discharge partially controlled the yield and selectivity of species in a reforming process. The aspect of control was examined in view of the reaction kinetics. The possible mechanisms for the synergetic effect between the catalytic reaction and electric discharge on methanol–steam reforming were addressed. A discrete reaction path, particularly adsorption triggered by an electric discharge, was suggested to be the most likely mechanism for the synergetic effect. These results are expected to provide a guide for understanding the plasma–catalyst hybrid reaction

  13. Hyperbolic partial differential equations

    Witten, Matthew

    1986-01-01

    Hyperbolic Partial Differential Equations III is a refereed journal issue that explores the applications, theory, and/or applied methods related to hyperbolic partial differential equations, or problems arising out of hyperbolic partial differential equations, in any area of research. This journal issue is interested in all types of articles in terms of review, mini-monograph, standard study, or short communication. Some studies presented in this journal include discretization of ideal fluid dynamics in the Eulerian representation; a Riemann problem in gas dynamics with bifurcation; periodic M

  14. Successful removable partial dentures.

    Lynch, Christopher D

    2012-03-01

    Removable partial dentures (RPDs) remain a mainstay of prosthodontic care for partially dentate patients. Appropriately designed, they can restore masticatory efficiency, improve aesthetics and speech, and help secure overall oral health. However, challenges remain in providing such treatments, including maintaining adequate plaque control, achieving adequate retention, and facilitating patient tolerance. The aim of this paper is to review the successful provision of RPDs. Removable partial dentures are a successful form of treatment for replacing missing teeth, and can be successfully provided with appropriate design and fabrication concepts in mind.

  15. Beginning partial differential equations

    O'Neil, Peter V

    2011-01-01

    A rigorous, yet accessible, introduction to partial differential equations-updated in a valuable new edition Beginning Partial Differential Equations, Second Edition provides a comprehensive introduction to partial differential equations (PDEs) with a special focus on the significance of characteristics, solutions by Fourier series, integrals and transforms, properties and physical interpretations of solutions, and a transition to the modern function space approach to PDEs. With its breadth of coverage, this new edition continues to present a broad introduction to the field, while also addres

  16. Combining Teletherapy and On-line Language Exercises in the Treatment of Chronic Aphasia: An Outcome Study

    Richard D. Steele

    2015-01-01

    Full Text Available We report a 12-week outcome study in which nine persons with long-term chronic aphasia received individual and group speech-language teletherapy services, and also used on-line language exercises to practice from home between therapy sessions.  Participants were assessed at study initiation and completion using the Western Aphasia Battery, a portion of the Communicative Effectiveness Index, ASHA National Outcome Measurement System, and RIC Communication Confidence Rating Scale for Aphasia; additionally participants were polled regarding satisfaction at discharge.  Pre-treatment and post-treatment means were calculated and compared, and matched t-tests were used to determine significance of improvements following treatment, with patterns of independent on-line activity analyzed.  Analysis of scores shows that means improved on most measures following treatment, generally significantly: the WAB AQ improved +3.5 (p = .057; the CETI Overall (of items administered — +17.8 (p = .01, and CCRSA Overall — + 10.4 (p = .0004.  Independent work increased with time, and user satisfaction following participation was high.

  17. Partial knee replacement - slideshow

    ... page: //medlineplus.gov/ency/presentations/100225.htm Partial knee replacement - series—Normal anatomy To use the sharing ... A.M. Editorial team. Related MedlinePlus Health Topics Knee Replacement A.D.A.M., Inc. is accredited ...

  18. Vessel Sewage Discharges: No-Discharge Zones (NDZs)

    States may petition the EPA to establish areas, called no discharge zones (NDZs), where vessel sewage discharges are prohibited. This page describes how NDZs are designated, the types of designations, who enforces them, and how to comply.

  19. Perceptions Towards On-line Banking Security: An Empirical Investigation of a Developing Country`s Banking Sector, how secure is On-line Banking

    Bongani Ngwenya; Khanyisa Malufu

    2012-01-01

    The increase in computer crime has led to scepticism about themove made by the banks to introduce on-line banking. Someview this as a noble move which has made the banking systemmore efficient, reliable and secure, while others view it as arisky and insecure way of banking. The aim of this study wasto assess whether on-line banking in the developing countriesis secure or not. The researcher chose a descriptive-quantitativeresearch design. Data was collected using a self constructedquestionnai...

  20. Focussing on recycling attitudes of engineering students at UiTM Shah Alam - towards zero discharge

    Sharifah, A. S. A. K.; Khamaruddin, P. F. M.; Mohamad, N. N.; Saharuddin, M. Q.

    2018-03-01

    The generation of municipal solid waste (MSW) in Malaysia over the past 10 years has increased by 95 percent due to rapid development in the urban areas. 16.76 million tonne of waste is expected to be generated by Malaysian in the year 2020. Presently, there are about 70 percent of waste produced reported to be collected and 95 percent of it are disposed in landfills with only 5 percent left are being recycled. A 40 percent reduction of waste disposed to landfill by year 2020, through recycling and intermediate treatments such as waste to energy, composting and material recovery is very much needed as opening new landfills are not socially attractive. It clearly shows the awareness in reducing waste through recycling is still at infancy among Malaysians. Hence, a proper solid waste management should be enhanced through education among youngsters to ensure an integrated solid waste management towards zero discharge is achievable. The purpose of the research is two-fold. Firstly, to determine the recycling practices awareness among engineering students through manual and on-line survey. Secondly, a study on the effectiveness of recycling bins at the engineering students’ centre. The data collected were analyzed using statistical analysis. Results show that there is significant relationship (precycling using Chi square test. However, there is an insignificant relationship (p>0.05) between knowledge and awareness of students towards recycling using partial correlation. Nevertheless, it is important to note that recycling practices through the provision of well-designed recycling bins and continuous education will ensure a sound society upholding a Zero Discharge attitude in the future.

  1. Beginning partial differential equations

    O'Neil, Peter V

    2014-01-01

    A broad introduction to PDEs with an emphasis on specialized topics and applications occurring in a variety of fields Featuring a thoroughly revised presentation of topics, Beginning Partial Differential Equations, Third Edition provides a challenging, yet accessible,combination of techniques, applications, and introductory theory on the subjectof partial differential equations. The new edition offers nonstandard coverageon material including Burger's equation, the telegraph equation, damped wavemotion, and the use of characteristics to solve nonhomogeneous problems. The Third Edition is or

  2. BOOK REVIEW: ON-LINE EDUCATION: AN EMANCIPATING VISION

    Reviewed by Dr. Abdullah KUZU

    2006-04-01

    Full Text Available ON-LINE EDUCATION: AN EMANCIPATING VISION Written by Margarita Victoria Gomez Publisher: Cortez Editora ISBN 85-249-1062-3 São Paulo, Brazil, July 2004. Reviewed by Ricardo Romo TORRES Manuel Moreno Castaneda Maria del Sol Orozco Aguirre Universidad de Guadalajara Virtual MEXICO http://www.udgvirtual.udg.mx "On-line Education " is a book that meets the challenge to present itself as an unfinished text. In addition to demanding an active participation of the reader, it requires a predisposition to complete it through an also inconclusive dialogue. Among its goals we can find the search for education networks that remain under constant reconstruction, maintaining the emancipative vision as an imperative for the reconfiguration, as a constituted tissue for the scaffolding of subjects who impress,imagine, think and have a will. The unfinished part is presented in the following paragraph: "Similar to Babel according to Borges, knowledge is the product of a hazard in which fiction is the universe and where, out of fear of its multiple combinations, individual texts constitute an unfinished tale. In this labyrinth-shaped universe, the mirror and the recurrence do not allow finding the way out" page 134. The sense of being of man within a planetary community is framed by the ontological condition of conclusiveness; the requirement of being more, however, as well. This more is guided by the need for dialogue with others in terms of the opening and maintaining an unconcluded dialogue. The idea of a web or network leads to an articulating demand within the context of the category of wholeness. Based on this category, we will be able to present a reticulum of concepts where we can find included the web, subjectivity, identity, experience, mediation and, of course, digital literacy. This reticulum results in a concept of identified education with a condensed arrival point to something that the author defines as 'the pedagogy of virtuality'. The author is

  3. Experimental Evaluation of Discharge Characteristics in Inhomogeneous Fields under Air Flow

    Vogel, Stephan; Holbøll, Joachim

    2018-01-01

    voltages and a laminar air flow up to 22 m/s. In the first setup, the gap was exposed to a variable DC potential of up to 100 kV in order to create space charges in the vicinity of the electrode. The impact of the air flow on partial discharges and the dynamic behavior of the space charges is evaluated...... by means of partial discharge measurement and ultraviolet photography. The results show that the air flow increases the frequency of partial discharges in the gap due to an increased rate of space charge removal in the high field area around the tip of the electrode. The partial discharge behavior shows...... higher dependency on air flow at positive tip polarity as compared to the negative polarity. In the second setup, the standard impulse voltage created by a multistage impulse voltage generator was superimposed to a DC voltage, which continuously created corona and space charges around the tip...

  4. On-line determination of anions in pulp mills by capillary electrophoresis (CE); Tehdasoloissa tapahtuva anionien kapillaarielektroforeettinen on-line maeaeritys ja sen hyoedyntaeminen prosessivalvonnassa - MPKY 02

    Kokkonen, R; Holmberg, M; Vainikka, V [Finnish Pulp and Paper Research Institute, Espoo (Finland)

    1999-12-31

    The aim of the study was to set-up a process control system for on-line measurement of certain anions. Typical anions which forms precipitates in pulp and paper mills are oxalate, carbonate and sulphate. Thus it is important to develop a continuous process analyzing system to control concentration levels of this anions. For the preliminary tests of continuous determinations of chloride and sulphate anions in tap water a simple on-line system was build in KCL (The Finnish Pulp and Paper Research Institute) and connected to a capillary electroforesis apparatus. In the preliminary tests a chromate buffer (ph = 7.6) was used. Separation of chloride and sulphate was excellent but the stability of buffer was not good enough and it was usable only for few hours. After experimental studies VTT developed a stable capillary electrophoresis method based on mixed amine buffer and this was selected for an on-line method for determination of anions in process waters of the pulp and paper industry. In the preliminary on-line test (r = 20) repeatabilities of migration times of sulphate and chloride with the chromate buffer were < 5 % (RSD) and peak heights < 15 % (RSD). With the mixed amine buffer repeatabilities were better. The preliminary tests showed that it is possible to connect a capillary electrophoresis system to on-line measurements. For the moment no commercial on-line CE apparatus is available. (orig.)

  5. On-line determination of anions in pulp mills by capillary electrophoresis (CE); Tehdasoloissa tapahtuva anionien kapillaarielektroforeettinen on-line maeaeritys ja sen hyoedyntaeminen prosessivalvonnassa - MPKY 02

    Kokkonen, R.; Holmberg, M.; Vainikka, V. [Finnish Pulp and Paper Research Institute, Espoo (Finland)

    1998-12-31

    The aim of the study was to set-up a process control system for on-line measurement of certain anions. Typical anions which forms precipitates in pulp and paper mills are oxalate, carbonate and sulphate. Thus it is important to develop a continuous process analyzing system to control concentration levels of this anions. For the preliminary tests of continuous determinations of chloride and sulphate anions in tap water a simple on-line system was build in KCL (The Finnish Pulp and Paper Research Institute) and connected to a capillary electroforesis apparatus. In the preliminary tests a chromate buffer (ph = 7.6) was used. Separation of chloride and sulphate was excellent but the stability of buffer was not good enough and it was usable only for few hours. After experimental studies VTT developed a stable capillary electrophoresis method based on mixed amine buffer and this was selected for an on-line method for determination of anions in process waters of the pulp and paper industry. In the preliminary on-line test (r = 20) repeatabilities of migration times of sulphate and chloride with the chromate buffer were < 5 % (RSD) and peak heights < 15 % (RSD). With the mixed amine buffer repeatabilities were better. The preliminary tests showed that it is possible to connect a capillary electrophoresis system to on-line measurements. For the moment no commercial on-line CE apparatus is available. (orig.)

  6. Pulse electrical discharges in water and their applications

    Sunka, Pavel

    2001-01-01

    Partial electrical discharges in a water solution as a function of conductivity have been studied experimentally. Using needle-plate electrodes it has been demonstrated that the discharge evolves in two phases. During the first streamer-like phase, the discharge propagated with a velocity of 10 6 cm/s, while during the second arc-like phase the length of the discharge remained almost constant although the current still increased. Higher solution conductivity resulted in the generation of shorter channels, in larger discharge current, and in a higher plasma electron density. Degradation of phenol by the discharge has also been demonstrated. A special metallic electrode covered by a thin layer of porous ceramic has been developed and used for generation of a multichannel discharge. At comparable solution conductivity the ceramic-coated electrode produced plasma with very similar parameters as the needle-plate electrode configuration. Generation of strong focused shock waves by the multichannel discharge in a highly conductive solution has also been demonstrated

  7. Monitoring of lightning discharge

    Grigor'ev, V.A.

    2001-01-01

    The paper presents a brief description of a lightning discharge recording system developed at the NPO 'Monitoring Techniques' under the direction of V.M. Moskolenko (Moscow). The system provides information about dangerous environmental occurrences such as tornados and hurricanes, making the forecast of extreme situations possible, especially in the areas of dangerous industries and objects. The created automatic system can be useful in solving the tasks relating to nuclear test monitoring. (author)

  8. Underwater Ship Husbandry Discharges

    2011-11-01

    which entered into force in September of 2008, prohibits the use of harmful organotins such as tributyltin ( TBT ) in AFCs used on international...States. The use of TBT AFCs is explicitly prohibited under the VGP, and vessels must remove such coatings or paint over them to prevent toxic ...to hull husbandry include (1) the discharge of toxic chemicals used as biocides in AFCs and (2) biofouling as a vector for aquatic nuisance species

  9. Radioactive wastes and discharges

    NONE

    2000-07-01

    The guide sets out the radiation safety requirements and limits for the treatment of radioactive waste. They shall be observed when discharging radioactive substances into the atmosphere or sewer system, or when delivering solid, low-activity waste to a landfill site without a separate waste treatment plan. The guide does not apply to the radioactive waste resulting from the utilisation of nuclear energy or natural resources.

  10. Radioactive wastes and discharges

    2000-01-01

    The guide sets out the radiation safety requirements and limits for the treatment of radioactive waste. They shall be observed when discharging radioactive substances into the atmosphere or sewer system, or when delivering solid, low-activity waste to a landfill site without a separate waste treatment plan. The guide does not apply to the radioactive waste resulting from the utilisation of nuclear energy or natural resources

  11. Comparing On-Line to In-Person Course Delivery: An Empirical Study

    Jammie Price; Leslie Hossfeld

    2007-01-01

    Web-based technologies have been used in the classroom for over 15 years, including websites, email, listserves, library reserves, and text books. Among these options, social scientists range widely in their web usage – from simply posting syllabi on-line to delivering a course fully on-line in asynchronous learning networks. Use of web-based technology for instructional purposes is increasing, as is enrollment in distance education courses and on-line course offerings. Many administrators ...

  12. On-Line Booking Policies and Competitive Analysis of Medical Examination in Hospital

    Li Luo

    2014-01-01

    Full Text Available From the on-line point, we consider the hospital’s medical examination appointment problem with hierarchical machines. This approach eliminates the need for both demand forecasts and a risk-neutrality assumption. Due to different unit revenue, uncertain demand, and arrival of patients, we design on-line booking policies for two kinds of different situations from the perspective of on-line policy and competitive analysis. After that, we prove the optimal competitive ratios. Through numerical examples, we compare advantages and disadvantages between on-line policies and traditional policies, finding that there is different superiority for these two policies under different arrival sequences.

  13. Development and application of an on-line tritium production rate measuring method

    Yamaguchi, Seiya

    1989-06-01

    A highly sensitive on-line method for measuring the tritium production rate (TPR) of 6 Li was developed using the response difference of 6 Li and 7 Li-glass scintillators in a mixed neutron-gamma radiation field. A fitting method for subtracting the pulse height spectrum of 7 Li-glass from that of 6 Li-glass was introduced. The contribution of competing reactions such as 6 Li (n, n 'd) 4 He was estimated by kinematical analyses. An absolute value of the 6 Li content was determined by a chemical analysis. The thermal flux perturbation due to 6 Li-glass of various thickness and 6 Li contents was evaluated by measurement in a thermal neutron field and calculation by the modified Skyrme theory. A Monte Carlo calculation of the self-shielding effect was also made. The dependence of the self-shielding on neutron energy was examined by this Monte Carlo code. The edge effect, i.e., distortion of the pulse height spectrum due to partial energy deposition of the alpha and/or the triton, was investigated by measurement in a thermal neutron field and by a Monte Carlo simulation that was based on the scintillation mechanism and considered Bragg absorption and the ratio of contributions to luminescence by the alpha and the triton. The dependence of the edge effect on neutron energy was examined by this Monte Carlo code. This method was applied to the measurement of TPR distributions in simulated fusion blanket assemblies bombarded by D-T neutrons. Absolute values of the TPR were obtained with an experimental error of 3∼6 %. The measured results were compared with those of conventional β-counting methods and good agreement was obtained. An optical fiber system, using miniature lithium-glass scintillators, was fabricated for purpose of microminiaturization of detector size and adaption to strong electromagnetic field. Applicability of this system to a D-T neutron field was demonstrated. (author)

  14. Plasma Discharge Process in a Pulsed Diaphragm Discharge System

    Duan, Jianjin; Hu, Jue; Zhang, Chao; Wen, Yuanbin; Meng, Yuedong; Zhang, Chengxu

    2014-12-01

    As one of the most important steps in wastewater treatment, limited study on plasma discharge process is a key challenge in the development of plasma applications. In this study, we focus on the plasma discharge process of a pulsed diaphragm discharge system. According to the analysis, the pulsed diaphragm discharge proceeds in seven stages: (1) Joule heating and heat exchange stage; (2) nucleated site formation; (3) plasma generation (initiation of the breakdown stage); (4) avalanche growth and plasma expansion; (5) plasma contraction; (6) termination of the plasma discharge; and (7) heat exchange stage. From this analysis, a critical voltage criterion for breakdown is obtained. We anticipate this finding will provide guidance for a better application of plasma discharges, especially diaphragm plasma discharges.

  15. Near Infrared Spectroscopy for On-line Monitoring of Alkali- Free Cloth /Phenolic Resin Prepreg During Manufacture

    Yu Dong Huang

    2007-06-01

    Full Text Available A NIR method was developed for the on-line monitoring of alkali-freecloth/phenolic resin prepreg during its manufacturing process. First, the sizing content ofthe alkali-free cloth was analyzed, and then the resin, soluble resin and volatiles content ofthe prepreg was analyzed simultaneously using the FT-NIR spectrometer. Partial leastsquare (PLS regression was used to develop the calibration models, which for the sizingcontent was preprocessed by 1stDER MSC, for the volatile content by 1stDER VN, forthe soluble resin content by 1stDER MSC and for the resin content by the VN spectraldata preprocessing method. RMSEP of the prediction model for the sizing content was0.732 %, for the resin content it was 0.605, for the soluble resin content it was 0.101 andfor volatiles content it was 0.127. The results of the paired t-test revealed that there was nosignificant difference between the NIR method and the standard method. The NIRspectroscopy method could be used to predict the resin, soluble resin and the volatilescontent of the prepreg simultaneously, as well as sizing content of alkali-free cloth. Theprocessing parameters of the prepreg during manufacture could be adjusted quickly withthe help of the NIR analysis results. The results indicated that the NIR spectroscopymethod was sufficiently accurate and effective for the on-line monitoring of alkali-freecloth/phenolic resin prepreg.

  16. Compact Intracloud Discharges

    Smith, David A. [Univ. of Colorado, Boulder, CO (United States)

    1998-11-01

    In November of 1993, mysterious signals recorded by a satellite-borne broadband VHF radio science experiment called Blackboard led to a completely unexpected discovery. Prior to launch of the ALEXIS satellite, it was thought that its secondary payload, Blackboard, would most often detect the radio emissions from lightning when its receiver was not overwhelmed by noise from narrowband communication carriers. Instead, the vast majority of events that triggered the instrument were isolated pairs of pulses that were one hundred times more energetic than normal thunderstorm electrical emissions. The events, which came to be known as TIPPs (for transionospheric pulse pairs), presented a true mystery to the geophysics community. At the time, it was not even known whether the events had natural or anthropogenic origins. After two and one half years of research into the unique signals, two ground-based receiver arrays in New Mexico first began to detect and record thunderstorm radio emissions that were consistent with the Blackboard observations. On two occasions, the ground-based systems and Blackboard even recorded emissions that were produced by the same exact events. From the ground based observations, it has been determined that TIPP events areproduced by brief, singular, isolated, intracloud electrical discharges that occur in intense regions of thunderstorms. These discharges have been dubbed CIDS, an acronym for compact intracloud discharges. During the summer of 1996, ground-based receiver arrays were used to record the electric field change signals and broadband HF emissions from hundreds of CIDS. Event timing that was accurate to within a few microseconds made possible the determination of source locations using methods of differential time of arrival. Ionospheric reflections of signals were recorded in addition to groundwave/line-of-sight signals and were used to determine accurate altitudes for the discharges. Twenty-four CIDS were recorded from three

  17. Partial differential equations

    Evans, Lawrence C

    2010-01-01

    This text gives a comprehensive survey of modern techniques in the theoretical study of partial differential equations (PDEs) with particular emphasis on nonlinear equations. The exposition is divided into three parts: representation formulas for solutions; theory for linear partial differential equations; and theory for nonlinear partial differential equations. Included are complete treatments of the method of characteristics; energy methods within Sobolev spaces; regularity for second-order elliptic, parabolic, and hyperbolic equations; maximum principles; the multidimensional calculus of variations; viscosity solutions of Hamilton-Jacobi equations; shock waves and entropy criteria for conservation laws; and, much more.The author summarizes the relevant mathematics required to understand current research in PDEs, especially nonlinear PDEs. While he has reworked and simplified much of the classical theory (particularly the method of characteristics), he primarily emphasizes the modern interplay between funct...

  18. Discharging a DC bus capacitor of an electrical converter system

    Kajouke, Lateef A; Perisic, Milun; Ransom, Ray M

    2014-10-14

    A system and method of discharging a bus capacitor of a bidirectional matrix converter of a vehicle are presented here. The method begins by electrically shorting the AC interface of the converter after an AC energy source is disconnected from the AC interface. The method continues by arranging a plurality of switching elements of a second energy conversion module into a discharge configuration to establish an electrical current path from a first terminal of an isolation module, through an inductive element, and to a second terminal of the isolation module. The method also modulates a plurality of switching elements of a first energy conversion module, while maintaining the discharge configuration of the second energy conversion module, to at least partially discharge a DC bus capacitor.

  19. Continuous pile discharging machine

    Smith, P.P.

    1976-01-01

    A device for discharging cartridges from tubes under fluid pressure includes a cylindrical housing adapted to be seated in a leak-tight manner on the end of one of the tubes, a chute depending from the cylindrical housing near the end seated on the end of the tube, a rotatable piston having a wrench on the forward end thereof disposed in the cylindrical housing and adapted to manipulate a plug in the end of the tube, and a telescopic hydraulic ram adapted to move the piston toward the plug. In addition the wrench contains a magnet which prevents inadvertent uncoupling of the wrench and the plug. 7 claims, 10 drawing figures

  20. Capacitive discharge exciplex lamps

    Sosnin, E A; Erofeev, M V; Tarasenko, V F [High Current Electronics Institute, 2/3, Akademichesky Ave., Tomsk 634055 (Russian Federation)

    2005-09-07

    Simple-geometry exciplex lamps of a novel type excited by a capacitive discharge (CD-excilamps) have been investigated. An efficient radiation has been obtained on KrBr*, KrCl*, XeBr*, XeCl* molecules and I* atom. The highest values of efficiency of various working molecules are approximately 10-18%. The lifetime of the operating gas mixture in KrCl*, XeCl*, I* and XeBr* exciplex lamps excited by a CD is above 1000 h. Owing to the above-mentioned characteristics, the exciplex lamps excited by a CD are supposed to be very promising for various applications.

  1. Capacitive discharge exciplex lamps

    Sosnin, E A; Erofeev, M V; Tarasenko, V F

    2005-01-01

    Simple-geometry exciplex lamps of a novel type excited by a capacitive discharge (CD-excilamps) have been investigated. An efficient radiation has been obtained on KrBr*, KrCl*, XeBr*, XeCl* molecules and I* atom. The highest values of efficiency of various working molecules are approximately 10-18%. The lifetime of the operating gas mixture in KrCl*, XeCl*, I* and XeBr* exciplex lamps excited by a CD is above 1000 h. Owing to the above-mentioned characteristics, the exciplex lamps excited by a CD are supposed to be very promising for various applications

  2. Continuous pile discharging machine

    Smith, Phillips P.

    1976-05-11

    A device for discharging cartridges from tubes under fluid pressure includes a cylindrical housing adapted to be seated in a leak-tight manner on the end of one of the tubes, a chute depending from the cylindrical housing near the end seated on the end of the tube, a rotatable piston having a wrench on the forward end thereof disposed in the cylindrical housing and adapted to manipulate a plug in the end of the tube, and a telescopic hydraulic ram adapted to move the piston toward the plug. In addition the wrench contains a magnet which prevents inadvertent uncoupling of the wrench and the plug.

  3. Pulsed electrical discharge in gas bubbles in water

    Gershman, Sophia

    A phenomenological picture of pulsed electrical discharge in gas bubbles in water is produced by combining electrical, spectroscopic, and imaging methods. The discharge is generated by applying one microsecond long 5 to 20 kilovolt pulses between the needle and disk electrodes submerged in water. A gas bubble is generated at the tip of the needle electrode. The study includes detailed experimental investigation of the discharge in argon bubbles and a brief look at the discharge in oxygen bubbles. Imaging, electrical characteristics, and time-resolved optical emission data point to a fast streamer propagation mechanism and formation of a plasma channel in the bubble. Spectroscopic methods based on line intensity ratios and Boltzmann plots of line intensities of argon, atomic hydrogen, and argon ions and the examination of molecular emission bands from molecular nitrogen and hydroxyl radicals provide evidence of both fast beam-like electrons and slow thermalized ones with temperatures of 0.6 -- 0.8 electron-volts. The collisional nature of plasma at atmospheric pressure affects the decay rates of optical emission. Spectroscopic study of rotational-vibrational bands of hydroxyl radical and molecular nitrogen gives vibrational and rotational excitation temperatures of the discharge of about 0.9 and 0.1 electron-volt, respectively. Imaging and electrical evidence show that discharge charge is deposited on the bubble wall and water serves as a dielectric barrier for the field strength and time scales of this experiment. Comparing the electrical and imaging information for consecutive pulses applied at a frequency of 1 Hz indicates that each discharge proceeds as an entirely new process with no memory of the previous discharge aside from long-lived chemical species, such as ozone and oxygen. Intermediate values for the discharge gap and pulse duration, low repetition rate, and unidirectional character of the applied voltage pulses make the discharge process here unique

  4. Optimization of partial search

    Korepin, Vladimir E

    2005-01-01

    A quantum Grover search algorithm can find a target item in a database faster than any classical algorithm. One can trade accuracy for speed and find a part of the database (a block) containing the target item even faster; this is partial search. A partial search algorithm was recently suggested by Grover and Radhakrishnan. Here we optimize it. Efficiency of the search algorithm is measured by the number of queries to the oracle. The author suggests a new version of the Grover-Radhakrishnan algorithm which uses a minimal number of such queries. The algorithm can run on the same hardware that is used for the usual Grover algorithm. (letter to the editor)

  5. Application status of on-line nuclear techniques in analysis of coal quality

    Cai Shaohui

    1993-01-01

    Nuclear techniques are favourable for continuous on-line analysis, because they are fast, non-intrusive. They can be used in the adverse circumstances in coal industry. The paper reviews the application status of on-line nuclear techniques in analysis of coal quality and economic benefits derived from such techniques in developed countries

  6. On-line monitoring and control of animal-cell cultures

    Pol, van der J.J.

    1996-01-01


    On-line analysis and control of biotechnological processes is still the stepchild in industry. In general, only parameters as dissolved-oxygen concentration, pH and temperature are controlled on-line. Important parameters as substrate and inhibitor concentrations are only measured

  7. On-line scheduling of two-machine open shops where jobs arrive over time

    Chen, B.; Vestjens, A.P.A.; Woeginger, G.J.

    1998-01-01

    We investigate the problem of on-line scheduling two-machine open shops with the objective of minimizing the makespan.Jobs arrive independently over time, and the existence of a job is not known until its arrival. In the clairvoyant on-line model, the processing requirement of every job becomes

  8. College Students' Choice Modeling of Taking On-Line International Business Courses

    Yeh, Robert S.

    2006-01-01

    To understand students' choice behavior of taking on-line international business courses, a survey study is conducted to collect information regarding students' actual choices of taking on-line courses and potential factors that may have impacts on students' choices of online learning. Potential factors such as enrollment status, demographic…

  9. State of technology, system and solution supporting on-line maintenance - company's activities and products

    Nishitani, Junichi; Shimizu, Shunichi; Higasa, Hisakazu

    2010-01-01

    The new inspection system based on operator's maintenance and monitoring program of nuclear power plants was introduced in Japan more than one year ago and recommended on-line maintenance (maintenance during operation) will be carried out to increase capacity factor with safe and reliable operation of the plant. In this feature article, nine experts described the state of technology, system and solution supporting on-line maintenance - company's activities and products. These were titled as 'MHI's technology supporting on-line maintenance'. 'Technology supporting on-line maintenance - Toshiba's activities to upgrade monitoring and diagnostic service and maintenance management', 'AsahiKASEI's activities of on-line maintenance', 'Importance of information sharing of on-line maintenance and its ideal method-function of impact plan of IBM Maximo Asset Management for Nuclear', 'US's on-line maintenance and information systems', 'SmartProcedures realizing safe operation of nuclear power plant - proposal of computerized procedures', 'Ultrasonic leak detection system SDT170', 'Application of infrared thermography for equipment maintenance in nuclear power plant' and 'On-line condition monitoring system - condition eye'. (T. Tanaka)

  10. 75 FR 57826 - Culturally Significant Objects Imported for Exhibition Determinations: “On Line: Drawing Through...

    2010-09-22

    ... DEPARTMENT OF STATE [Public Notice 7180] Culturally Significant Objects Imported for Exhibition Determinations: ``On Line: Drawing Through the Twentieth Century'' SUMMARY: Notice is hereby given of the... that the objects to be included in the exhibition ``On Line: Drawing Through the Twentieth Century...

  11. Challenges and opportunities in ‘last mile’ logistics for on-line food retail

    Trienekens, Jacques; Hvolby, Hans Henrik; Turner, Paul

    2017-01-01

    Conventional approaches to logistics for food retail continue to be challenged by the rapid growth of on-line food retail. At the same time, ‘last mile’ logistics optimization for on-line retail also face challenges as changing consumer expectations, habits and purchasing patterns intersect with

  12. Multi-Mode Operation for On-line Uninterruptible Power Supply System

    Lu, Jinghang; Savaghebi, Mehdi; Golestan, Saeed

    2018-01-01

    To enhance the robustness and disturbance rejection ability of an on-line uninterruptible power supply (UPS) system, an Internal Model Control (IMC)-based DC-link voltage regulation method is proposed in this paper. Furthermore, the multi-mode operations of the on-line UPS system are investigated...

  13. Analyze On-line Star Economy Basing on Models of Entrepreneurship

    胡志豪

    2016-01-01

    The outstanding performance of the On-line Star Economy is bound up with social media and promotion by fans, stimulating a new round of consumption upgrading and capital tendency. There is no denying that the On-line Star Economy may be the fortuitous outcome of the times. But the fact remains it can be analyzed rationally using Models of Entrepreneurship.

  14. Escapist Motives for On-line Gaming and Strengthening of Weak Ties

    Sudzina, Frantisek; Razmerita, Liana

    on-line gaming. The research investigates Facebook and other on-line games separate-ly. A surprising result is that while most of the investigated escapist motives are positively correlated with strengthening of weak ties, the mundane breaking motive is negatively correlated with strengthening...

  15. A New Method of On-line Grid Impedance Estimation for PV Inverter

    Teodorescu, Remus; Asiminoaei, Lucian; Blaabjerg, Frede

    2004-01-01

    for on-line measuring the grid impedance is presented. The presented method requires no extra hardware being accommodated by typical PV inverters, sensors and CPU, to provide a fast and low cost approach of on-line impedance measurement. By injecting a non-characteristic harmonic current and measuring...

  16. Semi-on-line analysis for fast and precise monitoring of bioreaction processes

    Christensen, L.H.; Marcher, J.; Schulze, Ulrik

    1996-01-01

    Monitoring of substrates and products during fermentation processes can be achieved either by on-line, in situ sensors or by semi-on-line analysis consisting of an automatic sampling step followed by an ex situ analysis of the retrieved sample. The potential risk of introducing time delays...

  17. Penjualan on-line berbasis media sosial dalam perspektif ekonomi Islam

    M. Nur Riyanto Al-Arif

    2013-06-01

    Full Text Available Contemporary transactions along with the development of existing technologies have given rise to other forms of trading i.e. on-line trading. This paper aims to look at how the Islamic economic perspectives associated with on-line trading. The method used in this paper was library research. On-line trading had fulfilled the shariah principle, i.e. al-aqid, s}i>ghah, al-ma’qu>d alaih and the goal of the transaction. The transaction models that can be adopt in trading on line are bay’ al-mura>bah}ah and bay’ al-sala>m. Trading online had several advantage for buyer and seller, but trading on-line also had several problems. So, we must to had a strategy to minimize the various problems that may arise.

  18. Cryogenic high current discharges

    Meierovich, B.E.

    1994-01-01

    Z-pinches formed from frozen deuterium fibers by a rapidly rising current have enhanced stability and high neutron yield. The efforts to understand the enhanced stability and neutron yield on the basis of classical picture of Bennett equilibrium of the current channel has not given satisfactory results. The traditional approach does not take into account the essential difference between the frozen deuterium fiber Z-pinches and the usual Z-pinches such as exploding wires or classical gas-puffed Z-pinches. The very low temperature of the fiber atoms (10 K), together with the rapidly rising current, result in the coexistence of a high current channel with unionized fiber atoms for a substantial period of time. This phenomena lasts during the risetime. This approach takes into account the difference of the breakdown in a dielectric deuterium fiber and the breakdown in a metallic wire. This difference is essential to the understanding of specific features of cryogenic high current discharges. Z-pinches in frozen deuterium fibers should be considered as a qualitatively new phenomenon on the boundary of cryogenic and high current physics. It is a start of a new branch in plasma physics: the physics of cryogenic high current discharges

  19. FEDIX on-line information service: Design, develop, test, and implement an on-line research and education information service. Annual status report, September 1992--August 1993

    Rodman, J.A.

    1993-08-01

    Federal Information Exchange, Inc. (FIE) is a diversified information services company that is recognized as the major electronic link between the higher education community and the Federal government in the field of research administration. FIE provides a range of information related services to the government, academic and private sectors, including database management, software development and technical support. FEDIX is the on-line information service designed, developed and implemented by FIE to accomplish the following objectives: (1). Broaden the participation of the education community in Federal research and education programs by providing free and unrestricted on-line access to information from all participating Federal agencies; and (2). Provide the education community with on-line access to a single keyword-searchable system for research and educational funding opportunities at the participating Federal agencies.

  20. Auxiliary partial liver transplantation

    C.B. Reuvers (Cornelis Bastiaan)

    1986-01-01

    textabstractIn this thesis studies on auxiliary partial liver transplantation in the dog and the pig are reported. The motive to perform this study was the fact that patients with acute hepatic failure or end-stage chronic liver disease are often considered to form too great a risk for successful