Texas Instruments Technical Seminar: Power Management and Wireless

CERN Multimedia

2006-01-01

Monday 6 November TECHNICAL TRAINING SEMINAR 14:00 to 17:30 - Training Centre Auditorium (bldg. 593) Texas Instruments Technical Seminar: Power Management and Wireless Michael Scholtholt, Field Application Engineer / TEXAS INSTRUMENTS (US, D, CH) The range of power management products available today offers the possibility to find the best solution for each application. To select the right product it is therefore necessary to understand system requirements, how power supply products work, and where they differentiate. This Technical Training Seminar will also present an overview of how to choose the right RF platform based on markets and applications: nowadays almost everbody has at least one wireless product in use, and this tendency seems to increase significantly. Power Management Voltage mode vs. current mode control Differentiating DC/DC converters by analyzing control and compensation schemes: line / load regulation, transient response, BOM, board space, ease-of-use Introduction to evaluati...

Texas Instruments Technical Seminar: Power Management and Wireless

CERN Multimedia

2006-01-01

Monday 6 November TECHNICAL TRAINING SEMINAR 14:00 to 17:30 - Training Centre Auditorium (bldg. 593) Texas Instruments Technical Seminar: Power Management and Wireless Michael Scholtholt, Field Application Engineer / TEXAS INSTRUMENTS (US, D, CH) The range of power management products available today offers the possibility to find the best solution for each application. To select the right product it is therefore necessary to understand system requirements, how power supply products work, and where they differentiate. This Technical Training Seminar will also present an overview of how to choose the right RF platform based on markets and applications: nowadays almost everbody has at least one wireless product in use, and this tendency seems to increase significantly. Power Management Voltage mode vs. current mode control Differentiating DC/DC converters by analyzing control and compensation schemes: line / load regulation, transient response, BOM, board space, ease-of-use Introduction to evalu...

INIS Training Seminar 2013, 7-11 October 2013, Vienna, Austria. Presentations

International Nuclear Information System (INIS)

2013-01-01

The International Atomic Energy Agency organised an INIS Training Seminar from 7 to 11 October 2013 at its Headquarters in Vienna, Austria. The programme of the seminar concentrated on all aspects of INIS input preparation, indexing and classification, submission of non-conventional literature (NCL), searching the INIS Collection, and promotion of INIS. The training course consisted of lectures in the form of presentations, followed by discussions to allow an exchange of information and by practical sessions specifically on the topic. The course also consisted of hands-on training using computer training facilities

Test Anxiety: Evaluation of a Low-Threshold Seminar-Based Intervention for Veterinary Students.

Science.gov (United States)

Hahm, Nadine; Augustin, Sophie; Bade, Claudia; Ammer-Wies, Annett; Bahramsoltani, Mahtab

2016-01-01

Veterinary students are confronted with a high workload and an extensive number of examinations. However, the skills students gained in high school cannot serve as satisfactory coping strategies during veterinary training. This disparity can lead to test anxiety, as frequently reported by international surveys. In response, a pilot study was carried out to evaluate the effects of a newly developed training seminar to prevent and/or reduce test anxiety. The seminar was offered on a voluntary basis as a low-threshold intervention to first- and second-year veterinary students at three different veterinary schools in Germany. The intervention was offered in two different designs: in either a block or in a semester course containing cognitive and behavioral approaches as well as skill-deficit methods. By conducting a survey and interviews among the participants it was determined whether the contents of the seminar were perceived as helpful for counteracting test anxiety. The potential of the intervention was evaluated using a German test anxiety questionnaire (PAF). The contents of the training seminar were all assessed as beneficial but evaluated slightly differently by first- and second-year students. The results indicate that the seminar prevents and reduces test anxiety significantly compared to the control group students. The greatest effects were achieved by offering the intervention to first-year students and as a block course. As the participants benefit from the intervention independent of the extent of test anxiety, these results suggest that it may be profitable to integrate a workshop on coping strategies in the veterinary curriculum.

Comparison of endotracheal tube cuff pressure values before and after training seminar.

Science.gov (United States)

Özcan, Ayça Tuba Dumanlı; Döğer, Cihan; But, Abdülkadir; Kutlu, Işık; Aksoy, Şemsi Mustafa

2018-06-01

It is recommended that endotracheal cuff (ETTc) pressure be between 20 and 30 cm H 2 O. In this present study, we intend to observe average cuff pressure values in our clinic and the change in these values after the training seminar. The cuff pressure values of 200 patients intubated following general anesthesia induction in the operating theatre were measured following intubation. One hundred patients whose values were measured before the training seminar held for all physician assistants, and 100 patients whose values were measured after the training seminar were regarded as Group 1 and Group 2, respectively. Cuff pressures of both groups were recorded, and the difference between them was shown. Moreover, cuff pressure values were explored according to the working period of the physician assistants. There was no significant difference between the groups in terms of age, gender and tube diameters. Statistically significant difference was found between cuff pressure values before and after the training (p values decreased, however no statistically significant different was found (p values and potential complications.

TECHNICAL TRAINING SEMINAR

CERN Multimedia

Davide Vitè

2002-01-01

Wednesday 22 May From 14:00 to 17:00 - Training Centre Auditorium - bldg. 593, room 11 Reliability, Availability, Maintainability and Safety (RAMS) Philippe Galley, Vincent Brindejonc / LIGERON S.A., Saint Aubin, France This seminar will address Reliability, Availability, Maintainability and Safety (RAMS) engineering concepts to guarantee availability and safety of critical equipments, in particular in a high technology and R&D environment. Applications of these concepts will be presented. 14h00-14h30 Introduction to Reliability, Availability, Maintainability and Safety activities: general introduction to RAMS, basic definitions, integration of RAMS in a large project. 14h40-16h10 RAMS methodologies: Functional Analysis methodologies Preliminary Hazard Analysis Failure Mode Effects and Criticality Analysis (FMECA) Fault Tree Analysis Use of standards for Reliability predictions Reliability Block Diagrams for a system Advanced models, e.g. Markov's Graphs 16h30-17h00 Presentation of the activ...

TECHNICAL TRAINING SEMINAR

CERN Multimedia

Davide Vitè

2002-01-01

Wednesday 15 May 14:00 to 16:00 - Training Centre Auditorium - bldg. 593, room 11 Testing Embedded Software and Systems Ian Smith / SEVEN LAYER COMMUNICATIONS LTD, Edinburgh, Scotland The growing use of embedded processors has resulted in considerable challenges for software and system developers, to ensure that the products they produce function as required, without error. The increasing complexity of these products, and the systems they operate in, adds to the difficulty in testing these products effectively. These challenges will apply to the development of equipment and software for use on the LHC project. This seminar is aimed at anyone involved in the development and/or in the verification of embedded hardware, software or systems at CERN. It will provide an introduction to testing embedded products, and some insights into ways to address the growing complexity of modern embedded products. It will also show some of the methods Seven Layer Communications Ltd. have applied in developing effective test fac...

Low-voltage gyrotrons

International Nuclear Information System (INIS)

Glyavin, M. Yu.; Zavolskiy, N. A.; Sedov, A. S.; Nusinovich, G. S.

2013-01-01

For a long time, the gyrotrons were primarily developed for electron cyclotron heating and current drive of plasmas in controlled fusion reactors where a multi-megawatt, quasi-continuous millimeter-wave power is required. In addition to this important application, there are other applications (and their number increases with time) which do not require a very high power level, but such issues as the ability to operate at low voltages and have compact devices are very important. For example, gyrotrons are of interest for a dynamic nuclear polarization, which improves the sensitivity of the nuclear magnetic resonance spectroscopy. In this paper, some issues important for operation of gyrotrons driven by low-voltage electron beams are analyzed. An emphasis is made on the efficiency of low-voltage gyrotron operation at the fundamental and higher cyclotron harmonics. These efficiencies calculated with the account for ohmic losses were, first, determined in the framework of the generalized gyrotron theory based on the cold-cavity approximation. Then, more accurate, self-consistent calculations for the fundamental and second harmonic low-voltage sub-THz gyrotron designs were carried out. Results of these calculations are presented and discussed. It is shown that operation of the fundamental and second harmonic gyrotrons with noticeable efficiencies is possible even at voltages as low as 5–10 kV. Even the third harmonic gyrotrons can operate at voltages about 15 kV, albeit with rather low efficiency (1%–2% in the submillimeter wavelength region).

Effects of Koto Performance Seminar on Music Teacher Training

OpenAIRE

伊藤, 真; 平山, 裕基

2017-01-01

Music teachers need to have wide range of knowledge and teaching skills. This includes knowledge of world music such as Japanese traditional music, methods of instruction and performance skill. The department of Music Culture Education in Hiroshima University provides a variety of lectures and seminars on Japanese traditional music as a part of music teacher training, of which playing the koto (a long Japanese zither with 13 strings) is especially stressed as a continuous learning opportunity...

INIS regional training seminar for Asia and the Pacific

International Nuclear Information System (INIS)

Shimokawa, Jun-ichi; Ebinuma, Yukio

1985-01-01

Introduction is made to current practice of the INIS as well as beneficial execution of the 1984 INIS Training Seminar, which was held in Japan on 22-27 October. Under the proper guidance of three lecturers from IAEA. 28 trainees from 9 countries performed 4-day exercises in one of the three courses (subject analysis, descriptive cataloguing and online retrieval) in Tokyo. All of the participants visited to see some organizations related to information processing and documentation in Tsukuba Science City and JAERI at Tokai-mura for the last two day. These curriculum led to not only realization of substantial training but also promotion of friendly understanding of Japan and among them. (author)

Interdisciplinary Area of Research Offers Tool of Cross-Cultural Understanding: Cross-Cultural Student Seminar for Communication Training on Biomedical Engineering

Directory of Open Access Journals (Sweden)

Shigehiro Hashimoto

2013-12-01

Full Text Available Misunderstanding often occurs in a multidisciplinary field of study, because each field has its own background of thinking. Communication training is important for students, who have a potential to develop the multidisciplinary field of study. Because each nation has its own cultural background, communication in an international seminar is not easy, either. A cross-cultural student seminar has been designed for communication training in the multidisciplinary field of study. Students from a variety of back grounds have joined in the seminar. Both equations and figures are effective tools for communication in the field of science. The seminar works well for communication training in the multidisciplinary field of study of biomedical engineering. An interdisciplinary area of research offers the tool of cross-cultural understanding. The present study refers to author's several experiences: the student internship abroad, the cross-cultural student camp, multi PhD theses, various affiliations, and the creation of the interdisciplinary department.

INIS/AGRIS training seminar

International Nuclear Information System (INIS)

1976-01-01

The second joint INIS/AGRIS Training Seminar for the two essentially compatible information systems, INIS (International Nuclear Information System) and AGRIS (International System for the Agricultural Sciences and Technology), was held in Vienna, the first having taken place a year ago in Ankara. This year saw an expansion in the number of courses offered, which increased from nine to a total of 16. Additional courses in input preparation, and output utilization were offered, and improved retrieval facilities were available. Two joint courses for INIS and AGRIS magnetic tape users were given. With an increasing number of countries preparing input in machine-readable form, and with increasing utilization of magnetic tape output products, a forum for tape users was a logical addition at this time. Five courses were given in abstracting. INIS ATOMINDEX became the only international abstracting journal in the nuclear sciences with the cessation of Nuclear Science Abstracts at the end of June 1976, when INIS assumed responsibility for the inclusion of good abstracts. The significance of abstract quality and INIS specifications in terms of machine-readable format and characters, length and language were considered in specific courses. The courses on abstracting consisted of basic instruction on general principles, followed by abstracting in the areas of physics, chemistry, engineering and reactor technology, and the life sciences, where aspects specific to the particular field were emphasized. Participants were given an opportunity to attend demonstrations of the optical character recognition equipment and related hardware in use at the IAEA. Five computer terminals were placed at the disposal of seminar participants, thus permitting interactive retrieval of documents in on-line dialogue. An adaptation of STAIRS (STorage And Information Retrieval System by IBM) was used. An INIS test data-base of 60 000 documents and AGRIS test data-base of 80 000 documents were

27 CFR 6.94 - Educational seminars.

Science.gov (United States)

2010-04-01

... OF THE TREASURY LIQUORS âTIED-HOUSEâ Exceptions § 6.94 Educational seminars. An industry member may give or sponsor educational seminars for employees of retailers either at the industry member's... equipment, training seminars for employees of retailers, or tours of industry member's plant premises. This...

Technical training seminar: Data Converters and Linear Products for Signal Processing and Control

CERN Multimedia

Davide Vitè

2006-01-01

Monday 23 January 2006 TECHNICAL TRAINING SEMINAR from 14:00 to 17:30, Training Centre Auditorium (bldg. 503) Data Converters and Linear Products for Signal Processing and Control Marco Corsi, William Bright, Olrik Maier, Andrea Huder / TEXAS INSTRUMENTS (US, D, CH) Texas Instruments will present recent technology advances in design and manufacturing of A/D and D/A converters, and of operational amplifiers. 14:00 - 15:30 HIGH SPEED - Technology and the new process BiCom3: High speed ADCs, DACs, operational amplifiers 15:30 - 15:45 coffee 15:45 - 17:15 HIGH PRECISION - Technology and the new process HPA07: High precision ADCs, DACs, operational amplifiers questions, discussion Industrial partners: Robert Medioni, François Caloz Spoerle Electronic, CH-1440 Montagny (VD), Switzerland Phone: + 41 24 447 01 37, email: RMedioni@spoerle.com, http://www.spoerle.com Language: English. Free seminar (no registration). Organiser: Davide Vitè / HR-PMD-ATT / 75141 For more information, visit the Te...

Bootstrapped Low-Voltage Analog Switches

DEFF Research Database (Denmark)

Steensgaard-Madsen, Jesper

1999-01-01

Novel low-voltage constant-impedance analog switch circuits are proposed. The switch element is a single MOSFET, and constant-impedance operation is obtained using simple circuits to adjust the gate and bulk voltages relative to the switched signal. Low-voltage (1-volt) operation is made feasible...

Low-Voltage Switched-Capacitor Circuits

DEFF Research Database (Denmark)

Bidari, E.; Keskin, M.; Maloberti, F.

1999-01-01

Switched-capacitor stages are described which can function with very low (typically 1 V) supply voltages, without using voltage boosting or switched op-amps. Simulations indicate that high performance may be achieved using these circuits in filter or data converter applications.......Switched-capacitor stages are described which can function with very low (typically 1 V) supply voltages, without using voltage boosting or switched op-amps. Simulations indicate that high performance may be achieved using these circuits in filter or data converter applications....

A comparison of seminar and computer based training on the accuracy and reliability of raters using the Children's Global Assessment Scale (CGAS).

Science.gov (United States)

Lundh, Anna; Kowalski, Jan; Sundberg, Carl Johan; Landén, Mikael

2012-11-01

The aim of this study was to compare two methods to conduct CGAS rater training. A total of 648 raters were randomized to training (CD or seminar), and rated five cases before and 12 months after training. The ICC at baseline/end of study was 0.71/0.78 (seminar), 0.76/0.78 (CD), and 0.67/0.79 (comparison). There were no differences in training effect in terms of agreement with expert ratings, which speaks in favor of using the less resource-demanding CD. However, the effect was modest in both groups, and untrained comparison group improved of the same order of magnitude, which proposes more extensive training.

Voltage Management in Unbalanced Low Voltage Networks Using a Decoupled Phase-Tap-Changer Transformer

DEFF Research Database (Denmark)

Coppo, Massimiliano; Turri, Roberto; Marinelli, Mattia

2014-01-01

The paper studies a medium voltage-low voltage transformer with a decoupled on load tap changer capability on each phase. The overall objective is the evaluation of the potential benefits on a low voltage network of such possibility. A realistic Danish low voltage network is used for the analysis...

TECHNICAL TRAINING SEMINAR: National Instruments

CERN Multimedia

Monique Duval

2004-01-01

From 9:30 to 12:00 and from 13:00 to 16:00 hrs - Council Chamber, Salle B, Salle des Pas Perdus National Instruments (NI) on Tour 2004 Claudia Jüngel, Evrem Yarkin, Joel Clerc, Hervé Baour / NATIONAL INSTRUMENTS The special event NI on Tour 2004, run in Germany, Austria and Switzerland, will be at CERN on March 30. Technical seminars and free introductory courses will be offered all day long in the Council Chamber, Salle B, and Salle des Pas Perdus (buildings 61 and 503). Data acquisition systems on PCs, industrial measurement and control techniques, advanced LabVIEW software and PXI instrumentation, and system components for tests and automation will be presented. Walk-in courses will address DIAdem, LabVIEW and data acquisition. Language: English and French Free seminars and courses, no registration Organisers: Rolf Stampfli / IT-CO / 78102 & 160367 / Rolf.Stampfli@cern.ch Davide Vitè / HR-PMD-ATT / 75141 Davide.Vite@cern.ch For more information and the complete event programme, please visit the...

Reliability of supply of switchgear for auxiliary low voltage in substations extra high voltage to high voltage

Directory of Open Access Journals (Sweden)

Perić Dragoslav M.

2015-01-01

Full Text Available Switchgear for auxiliary low voltage in substations (SS of extra high voltages (EHV to high voltage (HV - SS EHV/HV kV/kV is of special interest for the functioning of these important SS, as it provides a supply for system of protection and other vital functions of SS. The article addresses several characteristic examples involving MV lines with varying degrees of independence of their supply, and the possible application of direct transformation EHV/LV through special voltage transformers. Auxiliary sources such as inverters and diesel generators, which have limited power and expensive energy, are also used for the supply of switchgear for auxiliary low voltage. Corresponding reliability indices are calculated for all examples including mean expected annual engagement of diesel generators. The applicability of certain solutions of switchgear for auxiliary low voltage SS EHV/HV, taking into account their reliability, feasibility and cost-effectiveness is analyzed too. In particular, the analysis of applications of direct transformation EHV/LV for supply of switchgear for auxiliary low voltage, for both new and existing SS EHV/HV.

Lightning Overvoltage on Low-Voltage Distribution System

Science.gov (United States)

Michishita, Koji

The portion of the faults of a medium-voltage line, cause by lightning, tends to increase with often reaching beyond 30%. However, due to the recent progress of the lightning protection design, the number of faults has decreased to 1/3 of that at 30 years ago. As for the low-voltage distribution line, the fault rate has been estimated primarily, although the details of the overvoltages have not been studied yet. For the further development of highly information-oriented society, improvement of reliability of electric power supply to the appliance in a low-voltage customer will be socially expected. Therefore, it is important to establish effective lightning protection design of the low-voltage distribution system, defined to be composed of lines having mutual interaction on the customers' electric circuits, such as a low-voltage distribution line, an antenna line and a telecommunication line. In this report, the author interprets the recent research on the lightning overvoltage on a low-voltage distribution system.

Mitigation of Unbalanced Voltage Sags and Voltage Unbalance in CIGRE Low Voltage Distribution Network

DEFF Research Database (Denmark)

Mustafa, Ghullam; Bak-Jensen, Birgitte; Mahat, Pukar

2013-01-01

Any problem with voltage in a power network is undesirable as it aggravates the quality of the power. Power electronic devices such as Voltage Source Converter (VSC) based Static Synchronous Compensator (STATCOM) etc. can be used to mitigate the voltage problems in the distribution system...... to unbalanced faults. The compensation of unbalanced voltage sags and voltage unbalance in the CIGRE distribution network is done by using the four STATCOM compensators already existing in the test grid. The simulations are carried out in DIgSILENT power factory software version 15.0........ The voltage problems dealt with in this paper are to show how to mitigate unbalanced voltage sags and voltage unbalance in the CIGRE Low Voltage (LV) test network and net-works like this. The voltage unbalances, for the tested cases in the CIGRE LV test network are mainly due to single phase loads and due...

Electrocardiogram voltage discordance: Interpretation of low QRS voltage only in the precordial leads.

Science.gov (United States)

Kim, Diana H; Verdino, Ralph J

To define clinical correlates of low voltage isolated to precordial leads on the surface electrocardiogram (ECG). Low voltage (V) on the ECG is defined as QRS Vvoltage isolated to the precordial leads with normal limb lead voltages is unclear. Twelve-lead ECGs with QRS V>5mm in one or more limb leads and voltage was found in 256 of 150,000 ECGs (~0.2%). 50.4% of patients had discordant ECGs that correlated with classic etiologies, with a higher incidence of LV dilation in those with classic etiologies than those without. Low precordial voltage is associated with classic etiologies and LV dilation. Copyright © 2017 Elsevier Inc. All rights reserved.

Low Power/Low Voltage Interface Circuitry for Capacitive Sensors

DEFF Research Database (Denmark)

Furst, Claus Efdmann

This thesis focuses mainly on low power/low voltage interface circuits, implemented in CMOS, for capacitive sensors. A brief discussion of demands and possibilities for analog signal processing in the future is presented. Techniques for low power design is presented. This is done by analyzing power...... power consumption. It is shown that the Sigma-Delta modulator is advantageous when embedded in a feedback loop with a mechanical sensor. Here a micro mechanical capacitive microphone. Feedback and detection circuitry for a capacitive microphone is presented. Practical implementations of low power....../low voltage interface circuitry is presented. It is demonstrated that an amplifier optimized for a capacitive microphone implemented in a standard 0.7 micron CMOS technology competes well with a traditional JFET amplifier. Furthermore a low power/low voltage 3rd order Sigma-Delta modulator is presented...

International Training Program: 3D S. Un. Cop - Scaling, Uncertainty and 3D Thermal-Hydraulics/Neutron-Kinetics Coupled Codes Seminar

International Nuclear Information System (INIS)

Pertuzzi, A.; D'Auria, F.; Bajs, T.; Reventos, F.

2006-01-01

Thermal-hydraulic system computer codes are extensively used worldwide for analysis of nuclear facilities by utilities, regulatory bodies, nuclear power plant designers and vendors, nuclear fuel companies, research organizations, consulting companies, and technical support organizations. The computer code user represents a source of uncertainty that can influence the results of system code calculations. This influence is commonly known as the 'user effect' and stems from the limitations embedded in the codes as well as from the limited capability of the analysts to use the codes. Code user training and qualification is an effective means for reducing the variation of results caused by the application of the codes by different users. This paper describes a systematic approach to training code users who, upon completion of the training, should be able to perform calculations making the best possible use of the capabilities of best estimate codes. In other words, the program aims at contributing towards solving the problem of user effect. The 3D S.UN.COP (Scaling, Uncertainty and 3D COuPled code calculations) seminars have been organized as follow-up of the proposal to IAEA for the Permanent Training Course for System Code Users (D'Auria, 1998). Four seminars have been held at University of Pisa (2003, 2004), at The Pennsylvania State University (2004) and at University of Zagreb (2005). It was recognized that such courses represented both a source of continuing education for current code users and a mean for current code users to enter the formal training structure of a proposed 'permanent' stepwise approach to user training. The 3D S.UN.COP 2005 was successfully held with the participation of 19 persons coming from 9 countries and 14 different institutions (universities, vendors, national laboratories and regulatory bodies). More than 15 scientists were involved in the organization of the seminar, presenting theoretical aspects of the proposed methodologies and

High-voltage test and training of plastic streamer tubes for the DELPHI hadron calorimeter

International Nuclear Information System (INIS)

Alekseev, G.D.; Cellar, S.; Khomenko, B.A.; Korytov, A.V.; Kulinich, P.A.; Micelmacher, G.V.; Sedykh, Yu.V.; Toledo, R.

1987-01-01

The results of high-voltage test and training of plastic streamer tubes of the DELPHI hadron calorimeter are presented. The testing technique is considered in detail. The equipment for high-voltage training consists of a mini-computer, CAMAC-electronics, a controllable high-voltage supply and a digital ampermeter. The experimental results shows that high-voltage training of streamer tubes improves their characteristics. The value of dark current decreased up to 1 μA. The operational voltage range increased by a value more than 300 V

Mitigation of Voltage Sags in CIGRE Low Voltage Distribution Network

DEFF Research Database (Denmark)

Mustafa, Ghullam; Bak-Jensen, Birgitte; Mahat, Pukar

2013-01-01

Any problem in voltage in a power network is undesirable as it aggravates the quality of the power. Power electronic devices such as Voltage Source Converter (VSC) based Static Synchronous Compensator (STATCOM), Dynamic Voltage Restorer (DVR) etc. are commonly used for the mitigation of voltage p....... The compensation of voltage sags in the different parts of CIGRE distribution network is done by using the four STATCOM compensators already existing in the test grid. The simulations are carried out in DIgSILENT power factory software version 15.0.......Any problem in voltage in a power network is undesirable as it aggravates the quality of the power. Power electronic devices such as Voltage Source Converter (VSC) based Static Synchronous Compensator (STATCOM), Dynamic Voltage Restorer (DVR) etc. are commonly used for the mitigation of voltage...... problems in the distribution system. The voltage problems dealt with in this paper are to show how to mitigate voltage sags in the CIGRE Low Voltage (LV) test network and networks like this. The voltage sags, for the tested cases in the CIGRE LV test network are mainly due to three phase faults...

The Evaluation of Vocational Training. Report of a Seminar (University of Manchester, United Kingdom, January 1975).

Science.gov (United States)

Commission des Communautes Europeennes (Luxembourg).

Based on the working papers and the results of seminar discussions on the evaluation of vocational education in various European countries, this volume summarizes current European thinking on the evaluation of training programs. Chapter 1 describes and defines the different levels of analysis which can be used in evaluation: analysis in the…

Low Voltage Ride-Through Capability of a Single-Stage Single-Phase Photovoltaic System Connected to the Low-Voltage Grid

DEFF Research Database (Denmark)

Yang, Yongheng; Blaabjerg, Frede

2013-01-01

The progressively growing of single-phase photovoltaic (PV) systems makes the Distribution System Operators (DSO) to update or revise the existing grid codes in order to guarantee the availability, quality and reliability of the electrical system. It is expected that the future PV systems connected...... to the low-voltage grid will be more active with functionalities of low voltage ride-through (LVRT) and the grid support capability, which is not the case today. In this paper, the operation principle is demonstrated for a single-phase grid-connected PV system in low voltage ride through operation in order...... to map future challenges. The system is verified by simulations and experiments. Test results show that the proposed power control method is effective and the single-phase PV inverters connected to low-voltage networks are ready to provide grid support and ride-through voltage fault capability...

Low-Voltage Consumption Coordination for Loss Minimization and Voltage Control

DEFF Research Database (Denmark)

Juelsgaard, Morten; Sloth, Christoffer; Wisniewski, Rafal

2014-01-01

This work presents a strategy for minimizing active power losses in low-voltage grids, by coordinating the consumption of electric vehicles and power generation from solar panels. We show that minimizing losses, also reduces voltage variations, and illustrate how this may be employed for increasing...

Voltage stability in low voltage microgrids in aspects of active and reactive power demand

Directory of Open Access Journals (Sweden)

Parol Mirosław

2016-03-01

Full Text Available Low voltage microgrids are autonomous subsystems, in which generation, storage and power and electrical energy consumption appear. In the paper the main attention has been paid to the voltage stability issue in low voltage microgrid for different variants of its operation. In the introduction a notion of microgrid has been presented, and also the issue of influence of active and reactive power balance on node voltage level has been described. Then description of voltage stability issue has been presented. The conditions of voltage stability and indicators used to determine voltage stability margin in the microgrid have been described. Description of the low voltage test microgrid, as well as research methodology along with definition of considered variants of its operation have been presented further. The results of exemplary calculations carried out for the daily changes in node load of the active and reactive power, i.e. the voltage and the voltage stability margin indexes in nodes have been presented. Furthermore, the changes of voltage stability margin indexes depending on the variant of the microgrid operation have been presented. Summary and formulation of conclusions related to the issue of voltage stability in microgrids have been included at the end of the paper.

Low-Energy Real-Time OS Using Voltage Scheduling Algorithm for Variable Voltage Processors

OpenAIRE

Okuma, Takanori; Yasuura, Hiroto

2001-01-01

This paper presents a real-time OS based on $ mu $ITRON using proposed voltage scheduling algorithm for variable voltage processors which can vary supply voltage dynamically. The proposed voltage scheduling algorithms assign voltage level for each task dynamically in order to minimize energy consumption under timing constraints. Using the presented real-time OS, running tasks with low supply voltage leads to drastic energy reduction. In addition, the presented voltage scheduling algorithm is ...

Coordinated Voltage Control of Distributed PV Inverters for Voltage Regulation in Low Voltage Distribution Networks

DEFF Research Database (Denmark)

Nainar, Karthikeyan; Pokhrel, Basanta Raj; Pillai, Jayakrishnan Radhakrishna

2017-01-01

This paper reviews and analyzes the existing voltage control methods of distributed solar PV inverters to improve the voltage regulation and thereby the hosting capacity of a low-voltage distribution network. A novel coordinated voltage control method is proposed based on voltage sensitivity...... optimization. The proposed method is used to calculate the voltage bands and droop settings of PV inverters at each node by the supervisory controller. The local controller of each PV inverter implements the volt/var control and if necessary, the active power curtailment as per the received settings and based...... on measured local voltages. The advantage of the proposed method is that the calculated reactive power and active power droop settings enable fair contribution of the PV inverters at each node to the voltage regulation. Simulation studies are conducted using DigSilent Power factory software on a simplified...

Evaluation of hands-on seminar for reduced port surgery using fresh porcine cadaver model

Directory of Open Access Journals (Sweden)

Saseem Poudel

2016-01-01

Full Text Available Background: The use of various biological and non-biological simulators is playing an important role in training modern surgeons with laparoscopic skills. However, there have been few reports of the use of a fresh porcine cadaver model for training in laparoscopic surgical skills. The purpose of this study was to report on a surgical training seminar on reduced port surgery using a fresh cadaver porcine model and to assess its feasibility and efficacy. Materials and Methods: The hands-on seminar had 10 fresh porcine cadaver models and two dry boxes. Each table was provided with a unique access port and devices used in reduced port surgery. Each group of 2 surgeons spent 30 min at each station, performing different tasks assisted by the instructor. The questionnaire survey was done immediately after the seminar and 8 months after the seminar. Results: All the tasks were completed as planned. Both instructors and participants were highly satisfied with the seminar. There was a concern about the time allocated for the seminar. In the post-seminar survey, the participants felt that the number of reduced port surgeries performed by them had increased. Conclusion: The fresh cadaver porcine model requires no special animal facility and can be used for training in laparoscopic procedures.

Evaluation of hands-on seminar for reduced port surgery using fresh porcine cadaver model.

Science.gov (United States)

Poudel, Saseem; Kurashima, Yo; Shichinohe, Toshiaki; Kitashiro, Shuji; Kanehira, Eiji; Hirano, Satoshi

2016-01-01

The use of various biological and non-biological simulators is playing an important role in training modern surgeons with laparoscopic skills. However, there have been few reports of the use of a fresh porcine cadaver model for training in laparoscopic surgical skills. The purpose of this study was to report on a surgical training seminar on reduced port surgery using a fresh cadaver porcine model and to assess its feasibility and efficacy. The hands-on seminar had 10 fresh porcine cadaver models and two dry boxes. Each table was provided with a unique access port and devices used in reduced port surgery. Each group of 2 surgeons spent 30 min at each station, performing different tasks assisted by the instructor. The questionnaire survey was done immediately after the seminar and 8 months after the seminar. All the tasks were completed as planned. Both instructors and participants were highly satisfied with the seminar. There was a concern about the time allocated for the seminar. In the post-seminar survey, the participants felt that the number of reduced port surgeries performed by them had increased. The fresh cadaver porcine model requires no special animal facility and can be used for training in laparoscopic procedures.

International training program: 3D S.UN.COP - Scaling, uncertainty and 3D thermal-hydraulics/neutron-kinetics coupled codes seminar

International Nuclear Information System (INIS)

Petruzzi, A.; D'Auria, F.; Bajs, T.; Reventos, F.

2006-01-01

Thermal-hydraulic system computer codes are extensively used worldwide for analysis of nuclear facilities by utilities, regulatory bodies, nuclear power plant designers and vendors, nuclear fuel companies, research organizations, consulting companies, and technical support organizations. The computer code user represents a source of uncertainty that can influence the results of system code calculations. This influence is commonly known as the 'user effect' and stems from the limitations embedded in the codes as well as from the limited capability of the analysts to use the codes. Code user training and qualification is an effective means for reducing the variation of results caused by the application of the codes by different users. This paper describes a systematic approach to training code users who, upon completion of the training, should be able to perform calculations making the best possible use of the capabilities of best estimate codes. In other words, the program aims at contributing towards solving the problem of user effect. The 3D S.UN.COP 2005 (Scaling, Uncertainty and 3D COuPled code calculations) seminar has been organized by University of Pisa and University of Zagreb as follow-up of the proposal to IAEA for the Permanent Training Course for System Code Users (D'Auria, 1998). It was recognized that such a course represented both a source of continuing education for current code users and a means for current code users to enter the formal training structure of a proposed 'permanent' stepwise approach to user training. The seminar-training was successfully held with the participation of 19 persons coming from 9 countries and 14 different institutions (universities, vendors, national laboratories and regulatory bodies). More than 15 scientists were involved in the organization of the seminar, presenting theoretical aspects of the proposed methodologies and holding the training and the final examination. A certificate (LA Code User grade) was released

Low voltage arc formation in railguns

Science.gov (United States)

Hawke, R.S.

1985-08-05

A low voltage plasma arc is first established across the rails behind the projectile by switching a low voltage high current source across the rails to establish a plasma arc by vaporizing a fuse mounted on the back of the projectile, maintaining the voltage across the rails below the railgun breakdown voltage to prevent arc formation ahead of the projectile. After the plasma arc has been formed behind the projectile a discriminator switches the full energy bank across the rails to accelerate the projectile. A gas gun injector may be utilized to inject a projectile into the breech of a railgun. The invention permits the use of a gas gun or gun powder injector and an evacuated barrel without the risk of spurious arc formation in front of the projectile.

TECHNICAL TRAINING SEMINAR

CERN Multimedia

Davide VITÈ

2002-01-01

Wednesday 27 February   from 9:00 to 12:00, LHC Auditorium, bldg. 33 7-018 LabVIEW Real-Time National Instruments, Ennetbaden, Switzerland With LabVIEW Real-Time, you can choose from a variety of RT Series hardware. Add a real-time data acquisition component into a larger measurement and automation system or create a single stand-alone real-time solution with data acquisition, signal conditioning, motion control, RS-232, GPIB instrumentation, and Ethernet connectivity. With the various hardware options, you can create a system to meet your precise needs today, while the modularity of the system means you can add to the solution as your system requirements grow. If you are interested in Reliable and Deterministic systems for Measurement and Automation, you will profit from this seminar. Agenda: Real-Time Overview LabVIEW RT Hardware Platforms - Linux on PXI Programming with LabVIEW RT Real-Time Operating Systems concepts Timing Applications Data Transfer Industrial Contact: Pierre-Andr&ea...

Modeling and Simulation of Low Voltage Arcs

NARCIS (Netherlands)

Ghezzi, L.; Balestrero, A.

2010-01-01

Modeling and Simulation of Low Voltage Arcs is an attempt to improve the physical understanding, mathematical modeling and numerical simulation of the electric arcs that are found during current interruptions in low voltage circuit breakers. An empirical description is gained by refined electrical

Extension algorithm for generic low-voltage networks

Science.gov (United States)

Marwitz, S.; Olk, C.

2018-02-01

Distributed energy resources (DERs) are increasingly penetrating the energy system which is driven by climate and sustainability goals. These technologies are mostly connected to low- voltage electrical networks and change the demand and supply situation in these networks. This can cause critical network states. Network topologies vary significantly and depend on several conditions including geography, historical development, network design or number of network connections. In the past, only some of these aspects were taken into account when estimating the network investment needs for Germany on the low-voltage level. Typically, fixed network topologies are examined or a Monte Carlo approach is used to quantify the investment needs at this voltage level. Recent research has revealed that DERs differ substantially between rural, suburban and urban regions. The low-voltage network topologies have different design concepts in these regions, so that different network topologies have to be considered when assessing the need for network extensions and investments due to DERs. An extension algorithm is needed to calculate network extensions and investment needs for the different typologies of generic low-voltage networks. We therefore present a new algorithm, which is capable of calculating the extension for generic low-voltage networks of any given topology based on voltage range deviations and thermal overloads. The algorithm requires information about line and cable lengths, their topology and the network state only. We test the algorithm on a radial, a loop, and a heavily meshed network. Here we show that the algorithm functions for electrical networks with these topologies. We found that the algorithm is able to extend different networks efficiently by placing cables between network nodes. The main value of the algorithm is that it does not require any information about routes for additional cables or positions for additional substations when it comes to estimating

Characterization of a low-voltage electron beam

International Nuclear Information System (INIS)

Berejka, A.J.

2004-01-01

Growing interests in low-voltage electron beam (EB) processing in areas that may require regulatory compliance, such as the curing of inks and coatings for food packaging materials and in the surface disinfection of medicinal and food containers, lead to the characterization of a low-voltage EB by two methods: a widely used thin radiochromic film and a film strip made on a continuous basis with an alanine coating. Using a laboratory unit, beam currents and voltages were varied and then optical density and alanine/matrix ratios were, respectively, determined. No inferences as to 'dose' were made. The radiochromic film was found to be insensitive to slight changes at low beam currents and to show considerable divergence and a broadening in response as current was increased across a meaningful range at the three applied beam voltages of 80, 100 and 120 kV. The electron paramagnetic resonance (EPR) increase in response of the alanine coated film taken as a ratio to an internal reference material within the test instrument itself was shown to have a linear response with respect to beam current and no divergence as current increased. The use of an alanine coating of thickness greater than that of the extrapolated range of the electron penetration offers a method for the characterization of the output of such very low-voltage beams

Low-Power, Low-Voltage Analog to Digital ΣΔ

DEFF Research Database (Denmark)

Wismar, Ulrik Sørensen

2007-01-01

, and since long operation time is required, low supply voltage and low power consumption are of paramount importance. Consequently, various topologies have been compared to nd the most power ecient audio frequency modulator topology. Chapter 4 of this thesis compares power consumption of two of the most...... prevalent topologies, the single-loop modulator with integration in discrete time and the single-loop modulator with integration in continuous time. Both modulator topologies are with feedback, and all intermediate signals are in the voltage mode. Chapter 5 treats a modulator without feedback. Another...

Novel Interleaved Converter with Extra-High Voltage Gain to Process Low-Voltage Renewable-Energy Generation

Directory of Open Access Journals (Sweden)

Chih-Lung Shen

2016-10-01

Full Text Available This paper presents a novel interleaved converter (NIC with extra-high voltage gain to process the power of low-voltage renewable-energy generators such as photovoltaic (PV panel, wind turbine, and fuel cells. The NIC can boost a low input voltage to a much higher voltage level to inject renewable energy to DC bus for grid applications. Since the NIC has two circuit branches in parallel at frond end to share input current, it is suitable for high power applications. In addition, the NIC is controlled in an interleaving pattern, which has the advantages that the NIC has lower input current ripple, and the frequency of the ripple is twice the switching frequency. Two coupled inductors and two switched capacitors are incorporated to achieve a much higher voltage gain than conventional high step-up converters. The proposed NIC has intrinsic features such as leakage energy totally recycling and low voltage stress on power semiconductor. Thorough theoretical analysis and key parameter design are presented in this paper. A prototype is built for practical measurements to validate the proposed NIC.

Technical Training Seminar: Physicists in the world of finance

CERN Multimedia

Davide Vitè

2006-01-01

Monday 27 February TECHNICAL TRAINING SEMINAR from 14:00 to 16:00, Council Chamber (bldg. 503) Physicists in the world of finance Oliver Cooke, Zhengyun Hu / LEHMAN BROTHERS (UK) Two PhD physicists will talk about their experiences of working in investment banking, describing what investment banks do and the jobs which attract physicists and engineers. They will introduce the derivatives markets, and explain the need for advanced modelling. In particular, they will present the many modelling techniques used, including Monte Carlo simulation, solving PDEs, stochastic calculus and data analysis. They will describe a typical day for a physicist in the world of finance, and present a case study in which they will show how they used an idea from physics to solve a finance problem. After a PhD and CERN fellowship on OPAL in the 1990s, Oliver Cooke moved to finance. He was initially a mathematical modeller of derivatives, and now is an exotic derivatives trader at Lehman Brothers in London. He will be j...

A Series of Seminars about NICE Environment during May / June 2004

CERN Multimedia

2004-01-01

Recently deployed at CERN, Windows XP and Office 2003 offer new functionalities. IT/IS Group has prepared a series of seminars to both introduce the CERN NICE environment to beginners and also to show how to benefit from the advanced features offered by the new versions of Windows and Office. Particular attention will be paid to Collaborative Tasks, like reviewing a document, planning a meeting and to Mobile Computing like working offline, remotely accessing CERN resources, etc.. Seminar planned for this week is: Make Office documents with Windows Word 2003 and Excel 2003 (EN), Thursday 17 June, 14:00 (special time). The seminars will take place in the IT Auditorium (bldg. 31, 3-005) and last for about one hour plus questions. No registration is necessary. More information is available at http://cern.ch/Win/Seminars/Tutorials. Interested users can also have a look to courses offered by CERN Technical Training, at http://cern.ch/humanresources/external/training/tech/office/te_office.asp.

Technical solutions for low-voltage microgrid concept

Energy Technology Data Exchange (ETDEWEB)

Laaksonen, H.

2011-07-01

Future electricity distribution networks with large amount of distributed energy resources will require creation of a totally new smart grid architecture. The micro grid concept is expected to play a major role in the new smart grid architecture. A special feature of microgrids is that during disturbances in the utility grid they can continue operation automatically in the island mode so that electricity supply to microgrid customers can be continued without any interruption. Thereby, the microgrid concept allows the reliability benefit of distributed energy resources to be realized while also fulfilling the future energy efficiency requirements. In this thesis a total technical concept for low-voltage microgrid which could be integrated into the future smart grids has been developed and specified. The key technical challenges of low-voltage microgrids are the transition to island operation, the power quality management and the microgrid protection especially during island operation. Essential part of the concept development involved the development of solutions and operation principles to these key technical challenges of low-voltage microgrids so that all these solutions would be compatible with each other. The role of one central energy storage unit and the location of it are very important in the developed concept from the low-voltage microgrid management and protection point of view. The development work with the related technical challenges was carried out in this thesis with PSCAD simulation software. PSCAD enabled the examination of a simultaneous interaction of different types of distributed energy resource units and loads both in the normal utility grid connected and in the island operation mode of the microgrid. This information from simulations with multiple component configurations was essential when the technical solutions were developed and these studies could not have been undertaken to this extent in a laboratory environment without major

Programme of Seminars January to March 2004

CERN Multimedia

2004-01-01

If you wish to participate in one of the following courses, please discuss with your supervisor and apply electronically directly from the course description pages that can be found on the Web at: http://www.cern.ch/Training/ or fill in an "application for training" form available from your Divisional Secretariat or from your DTO (Divisional Training Officer). Applications will be accepted in the order of their receipt. MANAGEMENT & COMMUNICATION Nathalie Dumeaux tel. 78144 management.communication@cern.ch Situation : 20.01.2004 DatesDaysPlaces Available** Bilingual seminars Communication Techniques-1/Techniques de communication-1 16, 17, 18 March 3 non Project Management/Gestion de projet 17, 18, 19 March 3 oui Seminars in English Communicating effectively 22, 23 January & 19, 20 February 4 yes Performance Appraisal MAPS 4, 5, 6 February 3 yes Performance Appraisal -MAPS 11, 12, 13 February 3 yes Séminaires en Français Formation à l'entreti...

A nanoscale piezoelectric transformer for low-voltage transistors.

Science.gov (United States)

Agarwal, Sapan; Yablonovitch, Eli

2014-11-12

A novel piezoelectric voltage transformer for low-voltage transistors is proposed. Placing a piezoelectric transformer on the gate of a field-effect transistor results in the piezoelectric transformer field-effect transistor that can switch at significantly lower voltages than a conventional transistor. The piezoelectric transformer operates by using one piezoelectric to squeeze another piezoelectric to generate a higher output voltage than the input voltage. Multiple piezoelectrics can be used to squeeze a single piezoelectric layer to generate an even higher voltage amplification. Coupled electrical and mechanical modeling in COMSOL predicts a 12.5× voltage amplification for a six-layer piezoelectric transformer. This would lead to more than a 150× reduction in the power needed for communications.

Summary report of a seminar on geosphere modelling requirements of deep disposal of low and intermediate level radioactive wastes

International Nuclear Information System (INIS)

Piper, D.; Paige, R.W.; Broyd, T.W.

1989-02-01

A seminar on the geosphere modelling requirements of deep disposal of low and intermediate level radioactive wastes was organised by WS Atkins Engineering Sciences as part of Her Majesty's Inspectorate of Pollution's Radioactive Waste Assessment Programme. The objectives of the seminar were to review geosphere modelling capabilities and prioritise, if possible, any requirements for model development. Summaries of the presentations and subsequent discussions are given in this report. (author)

Low start-up voltage dc–dc converter with negative voltage control for thermoelectric energy harvesting

Directory of Open Access Journals (Sweden)

Pui-Sun Lei

2015-01-01

Full Text Available This Letter presents a low start-up voltage dc–dc converter for low-power thermoelectric systems which uses a native n-type MOS transistor as the start-up switch. The start-up voltage of the proposed converter is 300 mV and the converter does not need batteries to start up. The negative voltage control is proposed to reduce the leakage current caused by native n-type transistor and increase the efficiency. The proposed converter was designed using standard 0.18 µm CMOS process with chip size of 0.388 mm^2. The peak efficiency is 63% at load current of 1.5 mA. The proposed converter provides output voltage >1 V at maximum load current of 3.2 mA.

30 CFR 75.902 - Low- and medium-voltage ground check monitor circuits.

Science.gov (United States)

2010-07-01

... Medium-Voltage Alternating Current Circuits § 75.902 Low- and medium-voltage ground check monitor circuits. [Statutory Provisions] On or before September 30, 1970, low- and medium-voltage resistance... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Low- and medium-voltage ground check monitor...

International Training Program in Support of Safety Analysis: 3D S.UN.COP-Scaling, Uncertainty and 3D Thermal-Hydraulics/Neutron-Kinetics Coupled Codes Seminars

International Nuclear Information System (INIS)

Petruzzi, Alessandro; D'Auria, Francesco; Bajs, Tomislav; Reventos, Francesc

2006-01-01

Thermal-hydraulic system computer codes are extensively used worldwide for analysis of nuclear facilities by utilities, regulatory bodies, nuclear power plant designers and vendors, nuclear fuel companies, research organizations, consulting companies, and technical support organizations. The computer code user represents a source of uncertainty that can influence the results of system code calculations. This influence is commonly known as the 'user effect' and stems from the limitations embedded in the codes as well as from the limited capability of the analysts to use the codes. Code user training and qualification is an effective means for reducing the variation of results caused by the application of the codes by different users. This paper describes a systematic approach to training code users who, upon completion of the training, should be able to perform calculations making the best possible use of the capabilities of best estimate codes. In other words, the program aims at contributing towards solving the problem of user effect. The 3D S.UN.COP (Scaling, Uncertainty and 3D COuPled code calculations) seminars have been organized as follow-up of the proposal to IAEA for the Permanent Training Course for System Code Users [1]. Five seminars have been held at University of Pisa (2003, 2004), at The Pennsylvania State University (2004), at University of Zagreb (2005) and at the School of Industrial Engineering of Barcelona (2006). It was recognized that such courses represented both a source of continuing education for current code users and a mean for current code users to enter the formal training structure of a proposed 'permanent' stepwise approach to user training. The 3D S.UN.COP 2006 was successfully held with the attendance of 33 participants coming from 18 countries and 28 different institutions (universities, vendors, national laboratories and regulatory bodies). More than 30 scientists (coming from 13 countries and 23 different institutions) were

Scientific writing seminar for early-stage investigators in substance abuse research.

Science.gov (United States)

Guydish, Joseph; Masson, Carmen; Flentje, Annesa; Shopshire, Michael; Sorensen, James L

2016-01-01

There is little information on how to increase the scientific writing productivity of early-stage investigators in the addictions field. A scientific writing seminar is presented in this article, aiming to encourage manuscript writing and dissemination of addiction research, and outcomes are reported for 14 years of the seminar. In 14 years, there were 113 postdoctoral fellow enrollments in a 6-month writing seminar. Records of submission and publication rates of manuscripts were collected for 14 cohorts. Of the 113 participant enrollments, 97 (86%) submitted a manuscript for publication, and 87 participants (77%) published their manuscript. A scientific writing seminar may benefit writing productivity, but more research is needed to compare this training model with other existing models.

Evaluation of the Voltage Support Strategies for the Low Voltage Grid Connected PV

DEFF Research Database (Denmark)

Demirok, Erhan; Sera, Dezso; Teodorescu, Remus

2010-01-01

Admissible range of grid voltage is one of the strictest constraints for the penetration of distributed photovoltaic (PV) generators especially connection to low voltage (LV) public networks. Voltage limits are usually fulfilled either by network reinforcements or limiting of power injections from...... PVs. In order to increase PV penetration level further, new voltage support control functions for individual inverters are required. This paper investigates distributed reactive power regulation and active power curtailment strategies regarding the development of PV connection capacity by evaluation...... of reactive power efforts and requirement of minimum active power curtailment. Furthermore, a small scale experimental setup is built to reflect real grid interaction in the laboratory by achieving critical types of grid (weak and sufficiently stiff)....

Low cost photomultiplier high-voltage readout system

International Nuclear Information System (INIS)

Oxoby, G.J.; Kunz, P.F.

1976-10-01

The Large Aperture Solenoid Spectrometer (LASS) at Stanford Linear Accelerator Center (SLAC) requires monitoring over 300 voltages. This data is recorded on magnetic tapes along with the event data. It must also be displayed so that operators can easily monitor and adjust the voltages. A low-cost high-voltage readout system has been implemented to offer stand-alone digital readout capability as well as fast data transfer to a host computer. The system is flexible enough to permit use of a DVM or ADC and commercially available analogue multiplexers

Balint seminars: the transatlantic experience through videoconference.

Science.gov (United States)

Antoun, Jumana; Romani, Maya; Johnson, Alan; Brock, Clive; Hamadeh, Ghassan

2014-12-01

The Balint seminar is used in many family medicine residencies to improve and strengthen the patient-doctor relationship: to make better doctors. Given the lack of Balint leaders in developing countries, the family medicine department at the American University of Beirut (AUB) decided to collaborate with the Medical University of South Carolina (MUSC)-with more than 30 years of experience-to start Balint seminars through videoconferencing. Evaluate the feasibility and effectiveness of Balint seminars conducted through videoconference. A qualitative research using focus group and leaders' feedback to evaluate feasibility of delivery of Balint seminars through videoconference. A Polycom videoconference was set up between residents at AUB and two credentialed Balint leaders at MUSC. The videoconference was composed of two parts: (i) MUSC faculty facilitating Balint seminars; and (ii) MUSC and AUB faculty debriefing following each Balint session. Twenty-six videoconferences were conducted from 15 February 2013 to 31 March 2014. Four themes emerged: technology and connectivity issues, administrative issues, coordination among different time zones and cultural/contextual issues. The videoconferencing with family medicine residents at AUB seemed quite natural and very familiar to the Balint leaders at MUSC. The seminars encouraged the residents to see things from the patients' perspective, inspiring new thoughts and ideas on how to deal with troubling patients. Videoconference Balint seminars offer a promising way to extend the activity to health care providers in other disciplines, states and countries. Moreover, this format has the potential to increase the number of trained Balint leaders. © The Author 2014. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Dynamic range of low-voltage cascode current mirrors

DEFF Research Database (Denmark)

Bruun, Erik; Shah, Peter Jivan

1995-01-01

Low-voltage cascode current mirrors are reviewed with respect to the design limitations imposed if all transistors in the mirror are required to operate in the saturation region. It is found that both a lower limit and an upper limit exist for the cascode transistor bias voltage. Further, the use....... The proposed configuration has the advantage of simplicity combined with a complete elimination of the need for fixed bias voltages or bias currents in the current mirror. A disadvantage is that it requires a higher input voltage to the current mirror...

DC-link Voltage Control to Compensate Voltage Deviation for PV–BESSs Integrated System in Low-Voltage (LV Networks

Directory of Open Access Journals (Sweden)

Lee Gyu-sub

2016-01-01

Full Text Available The exhaustion of fossil fuel and the greenhouse gas emission are one of the most significant energy and environmental issues, respectively. Photovoltaic (PV generators and battery energy storage systems (BESSs have been significantly increased for recent years. The BESSs are mainly used for smoothing active power fluctuation of the PV. In this paper, PV–BESSs integration of two DC/DC converters and one AC/DC converter is investigated and DC-link voltage control to compensate the AC voltage deviation is proposed for the PV‒BESS system in low-voltage (LV networks.

For information: A Series of Seminars about NICE Environment during May / June 2004

CERN Multimedia

2004-01-01

Recently deployed at CERN, Windows XP and Office 2003 offer new functionalities. IT/IS Group has prepared a series of seminars to both introduce the CERN NICE environment to beginners and also to show how to benefit from the advanced features offered by the new versions of Windows and Office. Particular attention will be paid to Collaborative Tasks, like reviewing a document, planning a meeting and to Mobile Computing like working offline, remotely accessing CERN resources, etc.. The last seminar will be about: Making presentations with Powerpoint 2003 (FR), Tuesday 22nd of June, 14:30. The seminars will take place in the IT Auditorium (bldg. 31, 3-005) and last for about one hour plus questions. No registration is necessary. More information is available at http://cern.ch/Win/Seminars/Tutorials. Interested users can also have a look to courses offered by CERN Technical Training, at http://cern.ch/humanresources/external/training/tech/office/te_office.asp.

High-Voltage, Low-Power BNC Feedthrough Terminator

Science.gov (United States)

Bearden, Douglas

2012-01-01

This innovation is a high-voltage, lowpower BNC (Bayonet Neill-Concelman) feedthrough that enables the user to terminate an instrumentation cable properly while connected to a high voltage, without the use of a voltage divider. This feedthrough is low power, which will not load the source, and will properly terminate the instrumentation cable to the instrumentation, even if the cable impedance is not constant. The Space Shuttle Program had a requirement to measure voltage transients on the orbiter bus through the Ground Lightning Measurement System (GLMS). This measurement has a bandwidth requirement of 1 MHz. The GLMS voltage measurement is connected to the orbiter through a DC panel. The DC panel is connected to the bus through a nonuniform cable that is approximately 75 ft (approximately equal to 23 m) long. A 15-ft (approximately equal to 5-m), 50-ohm triaxial cable is connected between the DC panel and the digitizer. Based on calculations and simulations, cable resonances and reflections due to mismatched impedances of the cable connecting the orbiter bus and the digitizer causes the output not to reflect accurately what is on the bus. A voltage divider at the DC panel, and terminating the 50-ohm cable properly, would eliminate this issue. Due to implementation issues, an alternative design was needed to terminate the cable properly without the use of a voltage divider. Analysis shows how the cable resonances and reflections due to the mismatched impedances of the cable connecting the orbiter bus and the digitizer causes the output not to reflect accurately what is on the bus. After simulating a dampening circuit located at the digitizer, simulations were performed to show how the cable resonances were dampened and the accuracy was improved significantly. Test cables built to verify simulations were accurate. Since the dampening circuit is low power, it can be packaged in a BNC feedthrough.

A low-ripple chargepump circuit for high voltage applications

NARCIS (Netherlands)

Berkhout, M.; Berkhout, M.; van Steenwijk, G.; van Steenwijk, Gijs; van Tuijl, Adrianus Johannes Maria

1995-01-01

The subject of this paper is a fully integrated chargepump circuit with a very low output voltage ripple. At a supply voltage of 30V the chargepump can source 1mA at an output voltage of 40V. Two simple modifications to the classical chargepump circuit give a substantial reduction of the output

Simple programmable voltage reference for low frequency noise measurements

Science.gov (United States)

Ivanov, V. E.; Chye, En Un

2018-05-01

The paper presents a circuit design of a low-noise voltage reference based on an electric double-layer capacitor, a microcontroller and a general purpose DAC. A large capacitance value (1F and more) makes it possible to create low-pass filter with a large time constant, effectively reducing low-frequency noise beyond its bandwidth. Choosing the optimum value of the resistor in the RC filter, one can achieve the best ratio between the transient time, the deviation of the output voltage from the set point and the minimum noise cut-off frequency. As experiments have shown, the spectral density of the voltage at a frequency of 1 kHz does not exceed 1.2 nV/√Hz the maximum deviation of the output voltage from the predetermined does not exceed 1.4 % and depends on the holding time of the previous value. Subsequently, this error is reduced to a constant value and can be compensated.

Public hearing process for nuclear power plants. Seminar report

International Nuclear Information System (INIS)

1979-02-01

On June 26 and 27, 1978, the Nuclear Regulatory Commission conducted a seminar on the public hearing process for nuclear power plants. The seminar was intended to examine current practices regarding the conduct of public hearings and how these practices related to the statutory intent, to assess whether existing procedures are being followed, and to explore whether administrative or legal changes are warranted. The seminar format allowed exchanges of views among participants in the hearing process and was attended by members of the public, the General Accounting Office, Congressional staffs, NRC, and the nuclear industry. The report contains panel reports on scheduling of public hearings, procedures for Board notification, selection and training of panel members, hearing procedures, and Board functions

Impact of the Converter Control Strategies on the Drive Train of Wind Turbine during Voltage Dips

Directory of Open Access Journals (Sweden)

Fenglin Miao

2015-10-01

Full Text Available The impact of converter control strategies on the drive train of wind turbines during voltage dips is investigated in this paper using a full electromechanical model. Aerodynamics and tower vibration are taken into consideration by means of a simulation program, named FAST. Detailed gearbox and electrical subsystems are represented in MATLAB. The dynamic response of electromagnetic torque and its impact on the mechanical variables are the concern in this paper and the response of electrical variables is less discussed. From the mechanical aspects, the effect of rising power recovery speed and unsymmetrical voltage dips are analyzed on the basis of the dynamic response of the high-speed shaft (HSS. A comparison of the impact on the drive train is made for two converter control strategies during small voltage dips. Through the analysis of torque, speed and tower vibration, the results indicate that both power recovery speed and the sudden torque sag have a significant impact on drive trains, and the effects depend on the different control strategies. Moreover, resonance might be excited on the drive train by an unbalanced voltage.

Lightning-induced overvoltages in low-voltage systems

Energy Technology Data Exchange (ETDEWEB)

Hoeidalen, Hans Kristian

1997-12-31

Lightning-induced overvoltages (LIOs) are a main source of failures in low-voltage overhead line systems. This thesis deals mainly with calculations of LIOs aiming to enable the design of a proper voltage protection. Models for calculation of LIOs are adapted from the literature or developed based on measurements. The models used are believed to be fairly accurate for the first few microseconds, which is usually sufficient for predicting the maximum induced voltage in the system. The lightning channel is modelled by the Modified Transmission Line (MTL) model with the Transmission Line (TL) model as a special case. The coupling between the electrical fields from a lightning channel and an overhead line is modelled by Agrawal`s model. The attenuation of electrical fields over a lossy ground is modelled by Norton`s- or the Surface Impedance methods. The validity of all the applied models is analysed. In addition, measurements have been performed in order to develop models of distribution transformers and low-voltage power installation (LVPI) networks. Simple models of typical transformers and LVPIs are developed for calculations when specific data are unavailable. The practical range of values and its influence on the LIOs in a system is investigated. The main frequency range of interest related to LIOs is 10 kHz - 1 MHz in which all the models are accurate. The adapted or developed models are used to calculate LIOs in low-voltage systems. The influence of various key parameters in the system is investigated. Most important are the return stroke amplitude and rise time, the overhead line height and location, the termination of overhead line segments, neutral grounding, and the ground conductivity. 135 refs., 136 figs., 12 tabs.

The Application of Voltage Transformer Simulator in Electrical Test Training

Science.gov (United States)

Li, Nan; Zhang, Jun; Chai, Ziqi; Wang, Jingpeng; Yang, Baowei

2018-02-01

The voltage transformer test is an important means to monitor its operating state. The accuracy and reliability of the test data is directly related to the test skill level of the operator. However, the risk of test instruments damage, equipment being tested damage and electric shock in operator is caused by improper operation when training the transformer test. In this paper, a simulation device of voltage transformer is set up, and a simulation model is built for the most common 500kV capacitor voltage transformer (CVT), the simulation model can realize several test items of CVT by combing with teaching guidance platform, simulation instrument, complete set of system software and auxiliary equipment in Changchun. Many successful applications show that the simulation device has good practical value and wide application prospect.

International training program in support of safety analysis. 3D S.UN.COP-scaling uncertainty and 3D thermal-hydraulics/neutron-kinetics coupled codes seminars

International Nuclear Information System (INIS)

Petruzzi, Alessandro; D'Auria, Francesco; Bajs, Tomislav; Reventos, Francesc; Hassan, Yassin

2007-01-01

Thermal-hydraulic system computer codes are extensively used worldwide for analysis of nuclear facilities by utilities, regulatory bodies, nuclear power plant designers and vendors, nuclear fuel companies, research organizations, consulting companies, and technical support organizations. The computer code user represents a source of uncertainty that can influence the results of system code calculations. This influence is commonly known as the user effect' and stems from the limitations embedded in the codes as well as from the limited capability of the analysis to use the codes. Code user training and qualification is an effective means for reducing the variation of results caused by the application of the codes by different users. This paper describes a systematic approach to training code users who, upon completion of the training, should be able to perform calculations making the best possible use of the capabilities of best estimate codes. In other words, the program aims at contributing towards solving the problem of user effect. The 3D S.UN.COP (Scaling, Uncertainty and 3D COuPled code calculations) seminars have been organized as follow-up of the proposal to IAEA for the Permanent Training Course for System Code Users. Six seminars have been held at University of Pisa (2003, 2004), at The Pennsylvania State University (2004), at University of Zagreb (2005), at the School of Industrial Engineering of Barcelona (January-February 2006) and in Buenos Aires, Argentina (October 2006), being this last one requested by ARN (Autoridad Regulatoria Nuclear), NA-SA (Nucleoelectrica Argentina S.A) and CNEA (Comision Nacional de Energia Atomica). It was recognized that such courses represented both a source of continuing education for current code users and a mean for current code users to enter the formal training structure of a proposed 'permanent' stepwise approach to user training. The 3D S.UN.COP 2006 in Barcelona was successfully held with the attendance of 33

30 CFR 77.902 - Low- and medium-voltage ground check monitor circuits.

Science.gov (United States)

2010-07-01

... medium-voltage resistance grounded systems to portable and mobile equipment shall include a fail safe... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Low- and medium-voltage ground check monitor... OF UNDERGROUND COAL MINES Low- and Medium-Voltage Alternating Current Circuits § 77.902 Low- and...

A low knee voltage and high breakdown voltage of 4H-SiC TSBS employing poly-Si/Ni Schottky scheme

Science.gov (United States)

Kim, Dong Young; Seok, Ogyun; Park, Himchan; Bahng, Wook; Kim, Hyoung Woo; Park, Ki Cheol

2018-02-01

We report a low knee voltage and high breakdown voltage 4H-SiC TSBS employing poly-Si/Ni dual Schottky contacts. A knee voltage was significantly improved from 0.75 to 0.48 V by utilizing an alternative low work-function material of poly-Si as an anode electrode. Also, reverse breakdown voltage was successfully improved from 901 to 1154 V due to a shrunk low-work-function Schottky region by a proposed self-align etching process between poly-Si and SiC. SiC TSBS with poly-Si/Ni dual Schottky scheme is a suitable structure for high-efficiency rectification and high-voltage blocking operation.

Observability of Low Voltage grids

DEFF Research Database (Denmark)

Martin-Loeches, Ruben Sánchez; Iov, Florin; Kemal, Mohammed Seifu

2017-01-01

Low Voltage (LV) distribution power grids are experiencing a transformation from a passive to a more active role due to the increasing penetration of distributed generation, heat pumps and electrical vehicles. The first step towards a smarter operation of LV electrical systems is to provide grid ...... an updated state of the art on DSSE-AMI based, adaptive data collection techniques and database management system types. Moreover, the ongoing Danish RemoteGRID project is presented as a realistic case study.......Low Voltage (LV) distribution power grids are experiencing a transformation from a passive to a more active role due to the increasing penetration of distributed generation, heat pumps and electrical vehicles. The first step towards a smarter operation of LV electrical systems is to provide grid....... It becomes unrealistic to provide near real time full observability of the LV grid by applying Distribution System State Estimation (DSSE) utilizing the classical data collection and storage/preprocessing techniques. This paper investigates up-todate the observability problem in LV grids by providing...

Low voltage stress-induced leakage current and traps in ultrathin oxide (1.2 2.5 nm) after constant voltage stresses

Science.gov (United States)

Petit, C.; Zander, D.

2007-10-01

It has been shown that the low voltage gate current in ultrathin oxide metal-oxide-semiconductor devices is very sensitive to electrical stresses. Therefore, it can be used as a reliability monitor when the oxide thickness becomes too small for traditional electrical measurements to be used. In this work, we present a study on n-MOSCAP devices at negative gate bias in the direct tunneling (DT) regime. If the low voltage stress-induced leakage current (LVSILC) depends strongly on the low sense voltages, it also depends strongly on the stress voltage magnitude. We show that two LVSILC peaks appear as a function of the sense voltage in the LVSILC region and that their magnitude, one compared to the other, depends strongly on the stress voltage magnitude. One is larger than the other at low stress voltage and smaller at high stress voltage. From our experimental results, different conduction mechanisms are analyzed. To explain LVSILC variations, we propose a model of the conduction through the ultrathin gate oxide based on two distinctly different trap-assisted tunneling mechanisms: inelastic of gate electron (INE) and trap-assisted electron (ETAT).

Programme of Seminars September to December 2003

CERN Multimedia

2003-01-01

Dates Jours/ Days Places Disponibles*/ Places Available* Séminaires bilingues/Bilingual seminars Gestion de la qualité/Quality Management 10, 11, 12 November 3 oui Managing a CERN unit - to be a Manager/ Gérer une unité au CERN - Etre Manager (Module 3) 11, 12 November 2 non Gestion des risques /Risk Management 11, 12 December 2 oui Seminars in English Communicating effectively in your team 19, 20 November 2 yes Performance Appraisal Training MAPS 26, 27, 28 November 3 yes Managing by Project 3, 4 December 3 no Making Presentations 1, 2 December & 12 January 2004 3 yes Performance Appraisal Training MAPS 8, 9, 10 December 3 no Séminaires en Français Formation à l'entretien d'appréciation MAPS 26, 27, 28 novembre 3 non Formation à l'entretien d'appréciation MAPS 8, 9, 10 décembre 3 oui Animer ou participer à une ré...

Complete low power controller for high voltage power systems

International Nuclear Information System (INIS)

Sumner, R.; Blanar, G.

1997-01-01

The MHV100 is a custom CMOS integrated circuit, developed for the AMS experiment. It provides complete control for a single channel high voltage (HV) generator and integrates all the required digital communications, D to A and A to D converters, the analog feedback loop and output drivers. This chip has been designed for use in both distributed high voltage systems or for low cost single channel high voltage systems. The output voltage and current range is determined by the external components

Management & Communication: Programme of Seminars January to March 2004

CERN Multimedia

2004-01-01

If you wish to participate in one of the following courses, please discuss with your supervisor and apply electronically directly from the course description pages that can be found on the Web at: http://www.cern.ch/Training/ or fill in an "application for training" form available from your Divisional Secretariat or from your DTO (Divisional Training Officer). Applications will be accepted in the order of their receipt. MANAGEMENT & COMMUNICATION Nathalie Dumeaux tel. 78144 management.communication@cern.ch Situation : 20.01.2004 DatesDaysPlaces Available** Bilingual seminars Communication Techniques-1/Techniques de communication-1 16, 17, 18 March 3 non Project Management/Gestion de projet 17, 18, 19 March 3 oui Seminars in English Communicating effectively 22, 23 January & 19, 20 February 4 yes Performance Appraisal MAPS 4, 5, 6 February 3 yes Performance Appraisal -MAPS 11, 12, 13 February 3 yes Séminaires en Français Formation à l'entreti...

Management & communication: Programme of Seminars October to December 2004

CERN Multimedia

Nathalie Dumeaux

2004-01-01

If you wish to participate in one of the following courses, please discuss with your supervisor and apply electronically directly from the course description pages that can be found on the Web at: http://www.cern.ch/Training/ or fill in an 'application for training' form available from your Divisional Secretariat or from your DTO (Divisional Training Officer). Applications will be accepted in the order of their receipt. Situation : 11.10.2004 Bilingual seminar Dates Days Places available Communication Techniques - 1 20, 21, 22 October 3 oui Quality Management 8, 9 November 2 oui Risk Management 6, 7 December 2 oui Project Management - Case Study 22 November 1 oui Seminars in English Communicating effectively in your team 14, 15 October 2 yes Performance Appraisal - MAPS 24, 25, 26 November 3 yes Performance Appraisal - MAPS 8, 9, 10 December 3 yes Séminaires en Français Appréciation des performances - MAPS 1, 2, 3 d&eacut...

MANAGEMENT & COMMUNICATION: Programme of Seminars September to December 2003

CERN Document Server

2003-01-01

If you wish to participate in one of the following courses, please discuss with your supervisor and apply electronically directly from the course description pages that can be found on the Web at: http://www.cern.ch/Training/ or fill in an "application for training" form available from your Divisional Secretariat or from your DTO (Divisional Training Officer). Applications will be accepted in the order of their receipt. MANAGEMENT & COMMUNICATION Nathalie Dumeaux tel. 78144 management.communication@cern.ch Situation : 13.10.2003 Dates Days Places Available Bilingual seminars Interpersonal Communication (Module 1-CM) 21, 22, 23 October 3 non* Managing a CERN unit - to be a Manager (Module 2) 28, 29 October 2 non Quality Management 10, 11, 12 November 3 oui Managing a CERN unit - to be a Manager (Module 3) 11, 12 November 2 non Risk Management 11, 12 December 2 oui Seminars In English Communicating Effectively (first part) 12, 13 November & 4...

For information: A Series of Seminars about NICE Environment during May / June 2004

CERN Multimedia

2004-01-01

Recently deployed at CERN, Windows XP and Office 2003 offer new functionalities. IT/IS Group has prepared a series of seminars to both introduce the CERN NICE environment to beginners and also to show how to benefit from the advanced features offered by the new versions of Windows and Office. Particular attention will be paid to Collaborative Tasks, like reviewing a document, planning a meeting and to Mobile Computing like working offline, remotely accessing CERN resources, etc.. Seminars planned for these weeks are : Windows XP: a new experience (EN), Tuesday 8th of June, 14:30. Read your mail and more with Outlook 2003 (EN), Thursday 10th of June, 14:30. The seminars will take place in the IT Amphitheatre (bldg. 31, 3-005) and last for about one hour plus questions. No registration is necessary. More information is available at http://cern.ch/Win/Seminars/Tutorials. Interested users can also have a look to courses offered by CERN Technical Training, at http://cern.ch/humanresources/external/training/tec...

For Information: A Series of Seminars about NICE Environment during May / June 2004

CERN Multimedia

IT Department

2004-01-01

Recently deployed at CERN, Windows XP and Office 2003 offer new functionalities. IT/IS Group has prepared a series of seminars to both introduce the CERN NICE environment to beginners and also to show how to benefit from the advanced features offered by the new versions of Windows and Office. Particular attention will be paid to Collaborative Tasks, like reviewing a document, planning a meeting and to Mobile Computing like working offline, remotely accessing CERN resources, etc.. Seminars for planned these week are : Editing Web Sites with Frontpage 2003 (EN), Tuesday 25th of May, 14:30. Lire votre email et plus avec Outlook 2003 (FR), Thursday 27th of May, 14:30. The seminars will take place in the IT Amphitheatre (bldg. 31, 3-005) and last for about one hour plus questions. No registration is necessary. More information is available at http://cern.ch/Win/Seminars/Tutorials Interested users can also have a look to courses offered by CERN Technical Training, at http://cern.ch/humanresources/external/train...

Coordinated single-phase control scheme for voltage unbalance reduction in low voltage network.

Science.gov (United States)

Pullaguram, Deepak; Mishra, Sukumar; Senroy, Nilanjan

2017-08-13

Low voltage (LV) distribution systems are typically unbalanced in nature due to unbalanced loading and unsymmetrical line configuration. This situation is further aggravated by single-phase power injections. A coordinated control scheme is proposed for single-phase sources, to reduce voltage unbalance. A consensus-based coordination is achieved using a multi-agent system, where each agent estimates the averaged global voltage and current magnitudes of individual phases in the LV network. These estimated values are used to modify the reference power of individual single-phase sources, to ensure system-wide balanced voltages and proper power sharing among sources connected to the same phase. Further, the high X / R ratio of the filter, used in the inverter of the single-phase source, enables control of reactive power, to minimize voltage unbalance locally. The proposed scheme is validated by simulating a LV distribution network with multiple single-phase sources subjected to various perturbations.This article is part of the themed issue 'Energy management: flexibility, risk and optimization'. © 2017 The Author(s).

Ultra-Low Voltage Class AB Switched Current Memory Cell

DEFF Research Database (Denmark)

Igor, Mucha

1996-01-01

This paper presents the theoretical basis for the design of class AB switched current memory cells employing floating-gate MOS transistors, suitable for ultra-low-voltage applications. To support the theoretical assumptions circuits based on these cells were designed using a CMOS process with thr......This paper presents the theoretical basis for the design of class AB switched current memory cells employing floating-gate MOS transistors, suitable for ultra-low-voltage applications. To support the theoretical assumptions circuits based on these cells were designed using a CMOS process...... with threshold voltages of 0.9V. Both hand calculations and PSPICE simulations showed that the cells designed allowed a maximum signal range better than +/-13 micoamp, with a supply voltage down to 1V and a quiescent bias current of 1 microamp, resulting in a very high current efficiency and effective power...

Harmonic current interaction at a low voltage customer's installations

NARCIS (Netherlands)

Bhattacharyya, S.; Myrzik, J.M.A.; Kling, W.L.; Cobben, J.F.G.; Casteren, van J.

2009-01-01

The increased uses of power electronics and switching devices in the electricity network have changed the operational environment of the power system. These devices have nonlinear voltage-current characteristics and produce harmonic currents, and consequently distort the voltage waveform. A low

Design concept for radiation hardening of low power and low voltage dynamic memories

International Nuclear Information System (INIS)

Schleifer, H.; Ropp, T.V.D.; Reczek, W.

1995-01-01

A radiation hard low power, low voltage dynamic memory is obtained by the use of a dummy cell concept. Compared to conventional dummy cell concepts, this concept applies a fully sized dummy cell. By optimizing the dummy cell precharge voltage for 5 V and 3 V operation and the timing of the dummy word-line, the overall soft error rate (SER) of the chip is improved by 2 orders of magnitude. An additional improvement of 1 order of magnitude is possible for 3 V operation by adjusting substrate bias and cell plate voltage. The results are verified by an accelerated SER measurement with a radium 226 source and an additional field soft error study

Review of mixer design for low voltage - low power applications

Science.gov (United States)

Nurulain, D.; Musa, F. A. S.; Isa, M. Mohamad; Ahmad, N.; Kasjoo, S. R.

2017-09-01

A mixer is used in almost all radio frequency (RF) or microwave systems for frequency translation. Nowadays, the increase market demand encouraged the industry to deliver circuit designs to create proficient and convenient equipment with very low power (LP) consumption and low voltage (LV) supply in both digital and analogue circuits. This paper focused on different Complementary Metal Oxide Semiconductor (CMOS) design topologies for LV and LP mixer design. Floating Gate Metal Oxide Semiconductor (FGMOS) is an alternative technology to replace CMOS due to their high ability for LV and LP applications. FGMOS only required a few transistors per gate and can have a shift in threshold voltage (VTH) to increase the LP and LV performances as compared to CMOS, which makes an attractive option to replace CMOS.

Analysis of Voltage Support by Electric Vehicles and Photovoltaic in a Real Danish Low Voltage Network

DEFF Research Database (Denmark)

Knezovic, Katarina; Marinelli, Mattia; Juul Møller, René

2014-01-01

of incorporating electric vehicles (EVs) in a low voltage distribution network with high penetration of photovoltaic installations (PVs), and focuses on analysing potential voltage support functions from EVs and PVs. In addition, the paper evaluates the benefits that reactive power control may provide...

Low-voltage circuit breaker arcs—simulation and measurements

International Nuclear Information System (INIS)

Yang, Fei; Wu, Yi; Rong, Mingzhe; Sun, Hao; Ren, Zhigang; Niu, Chunping; Murphy, Anthony B

2013-01-01

As one of the most important electrical components, the low-voltage circuit breaker (LVCB) has been widely used for protection in all types of low-voltage distribution systems. In particular, the low-voltage dc circuit breaker has been arousing great research interest in recent years. In this type of circuit breaker, an air arc is formed in the interrupting process which is a 3D transient arc in a complex chamber geometry with splitter plates. Controlling the arc evolution and the extinction are the most significant problems. This paper reviews published research works referring to LVCB arcs. Based on the working principle, the arcing process is divided into arc commutation, arc motion and arc splitting; we focus our attention on the modelling and measurement of these phases. In addition, previous approaches in papers of the critical physical phenomenon treatment are discussed, such as radiation, metal erosion, wall ablation and turbulence in the air arc. Recommendations for air arc modelling and measurement are presented for further investigation. (topical review)

The Significance of Breakdown Voltages for Quality Assurance of Low-Voltage BME Ceramic Capacitors

Science.gov (United States)

Teverovsky, Alexander A.

2014-01-01

Application of thin dielectric, base metal electrode (BME) ceramic capacitors for high-reliability applications requires development of testing procedures that can assure high quality and reliability of the parts. In this work, distributions of breakdown voltages (VBR) in variety of low-voltage BME multilayer ceramic capacitors (MLCCs) have been measured and analyzed. It has been shown that analysis of the distributions can indicate the proportion of defective parts in the lot and significance of the defects. Variations of the distributions after solder dip testing allow for an assessment of the robustness of capacitors to soldering-related stresses. The drawbacks of the existing screening and qualification methods to reveal defects in high-value, low-voltage MLCCs and the importance of VBR measurements are discussed. Analysis has shown that due to a larger concentration of oxygen vacancies, defect-related degradation of the insulation resistance (IR) and failures are more likely in BME compared to the precious metal electrode (PME) capacitors.

Low-Voltage, Low-Power, and Wide-Tuning-Range Ring-VCO for Frequency ΔΣ Modulator

DEFF Research Database (Denmark)

Tuan Vu, Cao; Wisland, Dag T.; Lande, Tor Sverre

A low-voltage, low-power, and wide-tuning-range VCO which converts an analog input voltage to phase information for a frequency ΔΣ modulator is proposed in this paper. The VCO is based on a differential ring oscillator, which is improved with modified symmetric load and a positive feedback...

Seminar program for postgraduate specialty training in general practice: proposal for a 5-year thematic catalogue

Directory of Open Access Journals (Sweden)

Sommer, Susanne

2017-11-01

Full Text Available Introduction: In different German regions, seminar programs have been conducted for General practice residents. In each region, selection and teaching of learning content is conducted in a different manner. So far, no structured, standardized curriculum has been implemented nationwide. We have investigated, if the development of a common 5-year program of learning topics is conceivable between the different university departments of General practice in Germany.Method: The seminar program working group of the DEGAM (German College of General Practitioners and Family Physicians has conducted an online survey based on information gathered via preliminary telephone conference (n=7; physicians with postgraduate teaching experience among all German university departments of General Practice and two non-university teaching institutions, identified via the internet. 884 topics were extracted from 14 Seminar programs. The topics were entered in a database, discussed and categorized: Practice management/practice work flow/standardized documentation forms/quality management (n=33 topics, common acute and chronic diseases, including disease management programs (n=29 topics, communication, neurological, psychological and psychiatric consultations (n=24 topics, common medical problems, including eye, ear, nose, throat, skin and pediatric problems (n=99 Topics family physicians general approach, including epidemiology, shared decision making, test of time (n=42 Topics. These topics have been rated for priority and desirable number of teaching-units.Results: A catalogue of 111 topics was designed, encompassing 160 teaching units. There is a suggestion of wide topics collections plus an add-on catalogue.Conclusion: A proposal for a 5-year-thematic catalogue for postgraduate training of general practice residents in Germany has been developed. This newly developed curriculum has the potential to improve knowledge and skills that have not been covered during in

Training in nuclear medicine: Based on the recommendations of IAEA/WHO Seminar, 8-12 August 1988, Vienna, Austria

International Nuclear Information System (INIS)

1992-01-01

Nuclear Medicine is defined as a clinical specialty that utilizes the radionuclides for diagnosis, therapy and medical research. The radionuclides are used as unsealed sources of radioactivity. The diagnostic applications include both in vivo and in vitro uses of radioisotopes. There is hardly any medical research which does not use radioactive compounds. Only clinical research is considered within the purview of nuclear medicine. The Recommendations of IAEA/WHO seminar reviewed the needs of training in nuclear medicine mainly for the physicians with special emphasis on the needs of the developing countries

Training in nuclear medicine: Based on the recommendations of IAEA/WHO Seminar, 8-12 August 1988, Vienna, Austria

Energy Technology Data Exchange (ETDEWEB)

NONE

1993-12-31

Nuclear Medicine is defined as a clinical specialty that utilizes the radionuclides for diagnosis, therapy and medical research. The radionuclides are used as unsealed sources of radioactivity. The diagnostic applications include both in vivo and in vitro uses of radioisotopes. There is hardly any medical research which does not use radioactive compounds. Only clinical research is considered within the purview of nuclear medicine. The Recommendations of IAEA/WHO seminar reviewed the needs of training in nuclear medicine mainly for the physicians with special emphasis on the needs of the developing countries

Electromagnetic Simulation Seminar and Opera/Tosca update Seminar

CERN Multimedia

IT Department

2012-01-01

9 May 2012 Kjell Johnsen Auditorium – Room 30-7-018 Electromagnetic Simulation Seminar & Opera/Tosca update Seminar By Cobham Technical Services – Vector Fields Software Virtual prototyping using electromagnetic simulation software plays an important role in the design stage of many devices and the Opera software has been in use for this purpose at CERN for over a decade. A technical seminar will take place concerning the latest developments in electromagnetic design, analysis and multi-physics applications for large scientific experiments.  Information will be presented on applications such as superconducting magnets and ion-beam sources. The seminar will be presented by engineers/physicists from Cobham Technical Services – Vector Fields Software who develop the Opera program.  It is FREE to attend and is open to both current Opera software users and also those who wish to expand their knowledge and understand better the capabilities on offer. Prog...

Restoration of Low-Voltage Distribution Systems with Inverter-Interfaced DG Units

DEFF Research Database (Denmark)

Dietmannsberger, Markus; Wang, Xiongfei; Blaabjerg, Frede

2018-01-01

-area voltage collapse. This paper proposes a restoration strategy from zero voltage conditions for inverter-interfaced DG under islanded conditions. In the approach, a flexible and scalable Master DG inverter concept is introduced for distributed generations, where no communication is needed and an outage......The increasing share of distributed generation (DG) offers new chances in grid restoration of low-voltage distribution grids. Instead of relying on the transmission or high- and medium-voltage levels, establishing islanding operation in low-voltage grids might be a good option after a wide...... of the Master can be balanced by other DG inverters. The control strategy ensures the tracking of nominal values of the system voltage and frequency without zero steady-state error. The influences of non-controllable DG are also taken into account in the strategy with an effective countermeasure developed...

Astronomy Research Seminar

Science.gov (United States)

Johson, Jolyon; Genet, Russell; Armstrong, James; Boyce, Grady; Boyce, Pat; Brewer, Mark; Buchheim, Robert; Carro, Joseph; Estrada, Reed; Estrada, Chris; Freed, Rachel; Gillette, Sean; Harshaw, Richard; Hollis, Thomas; Kenney, John; McGaughey, Seven; McNab, Christine; Mohanan, Kakkala; Sepulveda, Babs; Wallace, Dan; Wallen, Vera

2015-05-01

Traditional science lectures and labs are often enhanced through project- and team-based learning. Some students go beyond these classroom studies by conducting research, often under the guidance of university professors. A one-semester astronomy research seminar was initiated in 2006 in collaboration with the community of professional and amateur double star astronomers. The result was dozens of jointly-authored papers published in the Journal of Double Star Observations and the Annual Proceedings of the Society of Astronomical Sciences. This seminar, and its affiliated community, launched a series of conferences and books, providing students with additional forums to share their double star research. The original seminar, and its derivatives, enhanced educational careers through college admissions and scholarships. To expand the seminar's reach, it was restructured from a few teams at one school, to many teams, each from a different school. A volunteer from each school became an assistant instructor. Most of them were seminar veterans, experienced astronomers, or science teachers. The assistant instructors, in turn, recruited enthusiastic students for their teams. To avoid student and instructor overload, the seminar focused on its three deliverables: a formal proposal, published paper, and public PowerPoint presentation. Future seminars may offer other astronomical research options such as exoplanet transit or eclipsing binary photometry.

The fabrication of 3-D nanostructures by a low- voltage EBL

Energy Technology Data Exchange (ETDEWEB)

Oh, Seung Hun [Department of Nano Science and Technology, Pusan National University (Korea, Republic of); Kim, Jae Gu [Department of Nano-Mechanical Systems, Korea Institute of Machinery and Materials (Korea, Republic of); Kim, Chang Seok [Department of Cogno-Mechatronics Engineering, Pusan National University (Korea, Republic of); Choi, Doo Sun; Chang, Sunghwan [Department of Nano-Mechanical Systems, Korea Institute of Machinery and Materials (Korea, Republic of); Jeong, Myung Yung, E-mail: myjeong@pusan.ac.kr [Department of Cogno-Mechatronics Engineering, Pusan National University (Korea, Republic of)

2011-02-15

Three-dimensional (3-D) structures are used in many applications, including the fabrication of opto-electronic and bio-MEMS devices. Among the various fabrication techniques available for 3-D structures, nano imprint lithography (NIL) is preferred for producing nanoscale 3-D patterns because of its simplicity, relatively short processing time, and high manufacturing precision. For efficient replication in NIL, a precise 3-D stamp must be used as an imprinting tool. Hence, we attempted the fabrication of original 3-D master molds by low-voltage electron beam lithography (EBL). We then fabricated polydimethylsiloxane (PDMS) stamps from the original 3-D mold via replica molding with ultrasonic vibration.First, we experimentally analyzed the characteristics of low-voltage EBL in terms of various parameters such as resist thickness, acceleration voltage, aperture size, and baking temperature. From these e-beam exposure experiments, we found that the exposure depth and width were almost saturated at 3 kV or lesser, even when the electron dosage was increased. This allowed for the fabrication of various stepped 3-D nanostructures at a low voltage. In addition, by using line-dose EBL, V-groove patterns could be fabricated on a cured electron resist (ER) at a low voltage and low baking temperature. Finally, the depth variation could be controlled to within 10 nm through superposition exposure at 1 kV. From these results, we determined the optimum electron beam exposure conditions for the fabrication of various 3-D structures on ERs by low-voltage EBL. We then fabricated PDMS stamps via the replica molding process.

Wideband Electrostatic Vibration Energy Harvester (e-VEH) Having a Low Start-Up Voltage Employing a High-Voltage Integrated Interface

International Nuclear Information System (INIS)

Dudka, A; Galayko, D; Basset, P; Cottone, F; Blokhina, E

2013-01-01

This paper reports on an electrostatic Vibration Energy Harvester (e-VEH) system, for which the energy conversion process is initiated with a low bias voltage and is compatible with wideband stochastic external vibrations. The system employs the auto-synchronous conditioning circuit topology with the use of a novel dedicated integrated low-power high-voltage switch that is needed to connect the charge pump and flyback – two main parts of the used conditioning circuit. The proposed switch is designed and implemented in AMS035HV CMOS technology. Thanks to the proposed switch device, which is driven with a low-voltage ground-referenced logic, the e-VEH system may operate within a large voltage range, from a pre-charge low voltage up to several tens volts. With such a high-voltage e-VEH operation, it is possible to obtain a strong mechanical coupling and a high rate of vibration energy conversion. The used transducer/resonator device is fabricated with a batch-processed MEMS technology. When excited with stochastic vibrations having an acceleration level of 0.8 g rms distributed in the band 110–170 Hz, up to 0.75 μW of net electrical power has been harvested with our system. This work presents an important milestone in the challenge of designing a fully integrated smart conditioning interface for the capacitive e-VEHs

Flow reversal at low voltage and low frequency in a microfabricated ac electrokinetic pump

DEFF Research Database (Denmark)

Gregersen, Misha Marie; Olesen, Laurits Højgaard; Brask, Anders

2007-01-01

measured in a regime, where both the applied voltage and the frequency are low, Vrms1.5 V and f20 kHz, compared to previously investigated parameter ranges. The impedance spectrum has been thoroughly measured and analyzed in terms of an equivalent circuit diagram to rule out trivial circuit explanations......Microfluidic chips have been fabricated in Pyrex glass to study electrokinetic pumping generated by a low-voltage ac bias applied to an in-channel asymmetric metallic electrode array. A measurement procedure has been established and followed carefully resulting in a high degree of reproducibility...... of the measurements over several days. A large coverage fraction of the electrode array in the microfluidic channels has led to an increased sensitivity allowing for pumping measurements at low bias voltages. Depending on the ionic concentration a hitherto unobserved reversal of the pumping direction has been...

PENERAPAN GLOBAL EXTREME PROGRAMMING PADA SISTEM INFORMASI WORKSHOP, SEMINAR DAN PELATIHAN DI LEMBAGA EDUKASI

Directory of Open Access Journals (Sweden)

Baginda Oloan Lubis

2016-09-01

Full Text Available Abstract Institutions of education as one of the service agencies workshops, seminars and training with information systems that are still manual at the time of printing id cards, the manufacture of attendance, printing certificates and report generation often had difficulty in searching data and other impacts arising from manual systems. Therefore the design of information systems or desktop based application creation is a solution to provide convenience to the user in the process of data processing, data retrieval to preparing reports. Model systems development workshops, seminars and training used in the design of information systems workshops, seminars and training using a model of Agile Software Development, which was discovered and developed by Robert Cecil Martin with process models Global Extreme Programming, namely the development of XP (Extreme Programming Life Cycle. While the tools used by the UML (Unifed Modeling Language and ERD (Entity Relationship Diagram. Hopefully, by the design of this system will allow a user who uses the id card printing, manufacture of attendance, certificate printing and reporting each end of the activity.

High voltage generator circuit with low power and high efficiency applied in EEPROM

International Nuclear Information System (INIS)

Liu Yan; Zhang Shilin; Zhao Yiqiang

2012-01-01

This paper presents a low power and high efficiency high voltage generator circuit embedded in electrically erasable programmable read-only memory (EEPROM). The low power is minimized by a capacitance divider circuit and a regulator circuit using the controlling clock switch technique. The high efficiency is dependent on the zero threshold voltage (V th ) MOSFET and the charge transfer switch (CTS) charge pump. The proposed high voltage generator circuit has been implemented in a 0.35 μm EEPROM CMOS process. Measured results show that the proposed high voltage generator circuit has a low power consumption of about 150.48 μW and a higher pumping efficiency (83.3%) than previously reported circuits. This high voltage generator circuit can also be widely used in low-power flash devices due to its high efficiency and low power dissipation. (semiconductor integrated circuits)

Frequency pulling in a low-voltage medium-power gyrotron

Science.gov (United States)

Luo, Li; Du, Chao-Hai; Huang, Ming-Guang; Liu, Pu-Kun

2018-04-01

Many recent biomedical applications use medium-power frequency-tunable terahertz (THz) sources, such as sensitivity-enhanced nuclear magnetic resonance, THz imaging, and biomedical treatment. As a promising candidate, a low-voltage gyrotron can generate watt-level, continuous THz-wave radiation. In particular, the frequency-pulling effect in a gyrotron, namely, the effect of the electron beam parameters on the oscillation frequency, can be used to tune the operating frequency. Most previous investigations used complicated and time-consuming gyrotron nonlinear theory to study the influence of many beam parameters on the interaction performance. While gyrotron linear theory investigation demonstrates the advantages of rapidly and clearly revealing the physical influence of individual key beam parameters on the overall system performance, this paper demonstrates systematically the use of gyrotron linear theory to study the frequency-pulling effect in a low-voltage gyrotron with either a Gaussian or a sinusoidal axial-field profile. Furthermore, simulations of a gyrotron operating in the first axial mode are carried out in the framework of nonlinear theory as a contrast. Close agreement is achieved between the two theories. Besides, some interesting results are obtained. In a low-current sinusoidal-profile cavity, the ranges of frequency variation for different axial modes are isolated from each other, and the frequency tuning bandwidth for each axial mode increases by increasing either the beam voltage or pitch factor. Lowering the voltage, the total tuning ranges are squeezed and become concentrated. However, the isolated frequency regions of each axial mode cannot be linked up unless the beam current is increased, meaning that higher current operation is the key to achieving a wider and continuous tuning frequency range. The results presented in this paper can provide a reference for designing a broadband low-voltage gyrotron.

Seminar on waste treatment and disposal; Seminar po obrashcheniyu s otkhodami i ikh utilizatsii

Energy Technology Data Exchange (ETDEWEB)

Sneve, Malgorzata Karpow; Snihs, Jan Olof

1999-07-01

A seminar on radioactive waste treatment and disposal was held 9 - 14 November 1998 in Oskarshamn, Sweden. The objective of the seminar was to exchange information on national and international procedures, practices and requirements for waste management. This information exchange was intended to promote the development of a suitable strategy for management of radioactive waste in Northwest Russia to be used as background for future co-operation in the region. The seminar focused on (1) overviews of international co-operation in the waste management field and national systems for waste management, (2) experiences from treatment of low- and intermediate-level radioactive waste, (3) the process of determining the options for final disposal of radioactive waste, (4) experiences from performance assessments and safety analysis for repositories intended for low- and intermediate level radioactive waste, (5) safety of storage and disposal of high-level waste. The seminar was jointly organised and sponsored by the Swedish Radiation Protection Institute (SSI), the Norwegian Radiation Protection Authority (NRPA), the Nordic Nuclear Safety Research (NKS) and the European Commission. In brief, the main conclusions are: (1) It is the prerogative of the Russian federal Government to devise and implement a waste management strategy without having to pay attention to the recommendations of the meeting, (2) Some participants consider that many points have already been covered in existing governmental documents, (3) Norway and Sweden would like to see a strategic plan in order to identify how and where to co-operate best, (4) There is a rigorous structure of laws in place, based on over-arching environmental laws, (5) Decommissioning of submarines is a long and complicated task, (6) There are funds and a desire for continued Norway/Sweden/Russia co-operation, (7) Good co-operation is already taking place.

50V All-PMOS Charge Pumps Using Low-Voltage Capacitors

KAUST Repository

Emira, Ahmed

2012-10-06

In this work, two high-voltage charge pumps are introduced. In order to minimize the area of the pumping capacitors, which dominates the overall area of the charge pump, high density capacitors have been utilized. Nonetheless, these high density capacitors suffer from low breakdown voltage which is not compatible with the targeted high voltage application. To circumvent the breakdown limitation, a special clocking scheme is used to limit the maximum voltage across any pumping capacitor. The two charge pump circuits were fabricated in a 0:6m CMOS technology with poly0-poly1 capacitors. The output voltage of the two charge pumps reached 42:8V and 51V while the voltage across any capacitor did not exceed the value of the input voltage. Compared to other designs reported in the literature, the proposed charge pump provides the highest output voltage which makes it more suitable for tuning MEMS devices.

50V All-PMOS Charge Pumps Using Low-Voltage Capacitors

KAUST Repository

Emira, Ahmed; AbdelGhany, M.; Elsayed, M.; Elshurafa, Amro M.; Sedky, S.; Salama, Khaled N.

2012-01-01

In this work, two high-voltage charge pumps are introduced. In order to minimize the area of the pumping capacitors, which dominates the overall area of the charge pump, high density capacitors have been utilized. Nonetheless, these high density capacitors suffer from low breakdown voltage which is not compatible with the targeted high voltage application. To circumvent the breakdown limitation, a special clocking scheme is used to limit the maximum voltage across any pumping capacitor. The two charge pump circuits were fabricated in a 0:6m CMOS technology with poly0-poly1 capacitors. The output voltage of the two charge pumps reached 42:8V and 51V while the voltage across any capacitor did not exceed the value of the input voltage. Compared to other designs reported in the literature, the proposed charge pump provides the highest output voltage which makes it more suitable for tuning MEMS devices.

Investigation of phase-wise voltage regulator control logics for compensating voltage deviations in an experimental low voltage network

DEFF Research Database (Denmark)

Hu, Junjie; Zecchino, Antonio; Marinelli, Mattia

2016-01-01

This paper investigates the control logics of an on-load tap-changer (OLTC) transformer by means of an experimental system validation. The experimental low-voltage unbalanced system consists of a decoupled single-phase OLTC transformer, a 75-metre 16 mm2 cable, a controllable single-phase resistive...... load and an electric vehicle, which has the vehicle-to-grid function. Three control logics of the OLTC transformer are described in the study. The three control logics are classified based on their control objectives and control inputs, which include network currents and voltages, and can be measured...... either locally or remotely. To evaluate and compare the control performances of the three control logics, all the tests use the same loading profiles. The experimental results indicate that the modified line compensation control can regulate voltage in a safe band in the case of various load...

A low-offset low-voltage CMOS Op Amp with rail-to-rail input and output ranges

NARCIS (Netherlands)

Holzmann, Peter J.; Wiegerink, Remco J.; Gierkink, Sander L.J.; Wassenaar, R.F.; Stroet, Peter; Stroet, P.M.

1996-01-01

A low voltage CMOS op amp is presented. The circuit uses complementary input pairs to achieve a rail-to-rail common mode input voltage range. Special attention has been given to the reduction of the op amp's systematic offset voltage. Gain boost amplifiers are connected in a special way to provide

Serious Games: A Seminar Map for International Business Schools

Science.gov (United States)

Witte, Anne E.

2014-01-01

One business school addressed the "zeitgeist" of the financial crisis by introducing in its inaugural seminar the cultural and ethical values too often absent from the types of transactions students are trained to manage. Drawing from cross-cultural and communication studies, the author tested "serious games"--cultural…

Distributed Low Voltage Ride-Through Operation of Power Converters in Grid-Connected Microgrids under Voltage Sags

DEFF Research Database (Denmark)

Zhao, Xin; Meng, Lexuan; Dragicevic, Tomislav

2015-01-01

it can make the MG a contributor in smooth ride through the faults. In this paper, a reactive power support strategy using droop controlled converters is proposed to aid MG riding through three phase symmetrical voltage sags. In such a case, the MGs should inject reactive power to the grid to boost...... the voltage in all phases at AC common bus. However, since the line admittances from each converter to point of common coupling (PCC) are not identical, the injected reactive power may not be equally shared. In order to achieve low voltage ride through (LVRT) capability along with a good power sharing...

Surge Protection in Low-Voltage AC Power Circuits: An Anthology

Science.gov (United States)

Martzloff, F. D.

2002-10-01

The papers included in this part of the Anthology provide basic information on the propagation of surges in low-voltage AC power circuits. The subject was approached by a combination of experiments and theoretical considerations. One important distinction is made between voltage surges and current surges. Historically, voltage surges were the initial concern. After the introduction and widespread use of current-diverting surge-protective devices at the point-of-use, the propagation of current surges became a significant factor. The papers included in this part reflect this dual dichotomy of voltage versus current and impedance mismatch effects versus simple circuit theory.

High Efficiency Power Converter for Low Voltage High Power Applications

DEFF Research Database (Denmark)

Nymand, Morten

The topic of this thesis is the design of high efficiency power electronic dc-to-dc converters for high-power, low-input-voltage to high-output-voltage applications. These converters are increasingly required for emerging sustainable energy systems such as fuel cell, battery or photo voltaic based...

Low voltage excess noise and shot noise in YBCO bicrystal junctions

DEFF Research Database (Denmark)

Constantinian, K.Y.; Ovsyannikov, G.A.; Borisenko, I.V.

2002-01-01

The spectral density of background noise emitted by symmetric bicrystal YBaCuO Josephson junctions on sapphire substrates have been measured by a low noise cooled HEMT amplifier for bias voltages up to V approximate to 50 mV. At relatively low voltages V noise rise has been...... registered. At large bias voltages V > 30 mV a clear dependence of noise power. exactly coinciding to the asymptote of the Schottky shot noise function, has been observed for the first time. Experimental results are discussed in terms of multiple Andreev reflections which may take place in d...

Load Insensitive, Low Voltage Quadrature Oscillator Using Single Active Element

Directory of Open Access Journals (Sweden)

Jitendra Mohan

2017-01-01

Full Text Available In this paper, a load insensitive quadrature oscillator using single differential voltage dual-X second generation current conveyor operated at low voltage is proposed. The proposed circuit employs single active element, three grounded resistors and two grounded capacitors. The proposed oscillator offers two load insensitive quadrature current outputs and three quadrature voltage outputs simultaneously. Effects of non-idealities along with the effects of parasitic are further studied. The proposed circuit enjoys the feature of low active and passive sensitivities. Additionally, a resistorless realization of the proposed quadrature oscillator is also explored. Simulation results using PSPICE program on cadence tool using 90 nm Complementary Metal Oxide Semiconductor (CMOS process parameters confirm the validity and practical utility of the proposed circuit.

Low-cost wireless voltage & current grid monitoring

Energy Technology Data Exchange (ETDEWEB)

Hines, Jacqueline [SenSanna Inc., Arnold, MD (United States)

2016-12-31

This report describes the development and demonstration of a novel low-cost wireless power distribution line monitoring system. This system measures voltage, current, and relative phase on power lines of up to 35 kV-class. The line units operate without any batteries, and without harvesting energy from the power line. Thus, data on grid condition is provided even in outage conditions, when line current is zero. This enhances worker safety by detecting the presence of voltage and current that may appear from stray sources on nominally isolated lines. Availability of low-cost power line monitoring systems will enable widespread monitoring of the distribution grid. Real-time data on local grid operating conditions will enable grid operators to optimize grid operation, implement grid automation, and understand the impact of solar and other distributed sources on grid stability. The latter will enable utilities to implement eneygy storage and control systems to enable greater penetration of solar into the grid.

Efficient Low-Voltage Operation of a CW Gyrotron Oscillator at 233 GHz.

Science.gov (United States)

Hornstein, Melissa K; Bajaj, Vikram S; Griffin, Robert G; Temkin, Richard J

2007-02-01

The gyrotron oscillator is a source of high average power millimeter-wave through terahertz radiation. In this paper, we report low beam power and high-efficiency operation of a tunable gyrotron oscillator at 233 GHz. The low-voltage operating mode provides a path to further miniaturization of the gyrotron through reduction in the size of the electron gun, power supply, collector, and cooling system, which will benefit industrial and scientific applications requiring portability. Detailed studies of low-voltage operation in the TE(2) (,) (3) (,) (1) mode reveal that the mode can be excited with less than 7 W of beam power at 3.5 kV. During CW operation with 3.5-kV beam voltage and 50-mA beam current, the gyrotron generates 12 W of RF power at 233.2 GHz. The EGUN electron optics code describes the low-voltage operation of the electron gun. Using gun-operating parameters derived from EGUN simulations, we show that a linear theory adequately predicts the low experimental starting currents.

Low QRS Voltage on Presenting Electrocardiogram Predicts Multi-vessel Disease in Anterior ST-segment Elevation Myocardial Infarction.

Science.gov (United States)

Kobayashi, Akihiro; Misumida, Naoki; Aoi, Shunsuke; Kanei, Yumiko

Low QRS voltage was reported to predict adverse outcomes in acute myocardial infarction in the pre-thrombolytic era. However, the association between low voltage and angiographic findings has not been fully addressed. We performed a retrospective analysis of patients with anterior ST-segment elevation myocardial infarction (STEMI). Low QRS voltage was defined as either peak to peak QRS complex voltage voltage. Patients with low voltage had a higher rate of multi-vessel disease (MVD) (76% vs. 52%, p=0.01). Patients with low voltage were more likely to undergo coronary artery bypass grafting (CABG) during admission (11% vs. 2%, p=0.028). Low voltage was an independent predictor for MVD (OR 2.50; 95% CI 1.12 to 6.03; p=0.032). Low QRS voltage was associated with MVD and in-hospital CABG in anterior STEMI. Copyright © 2017 Elsevier Inc. All rights reserved.

Selective electromembrane extraction at low voltages based on analyte polarity and charge

DEFF Research Database (Denmark)

Domínguez, Noelia Cabaleiro; Gjelstad, Astrid; Nadal, Andrea Molina

2012-01-01

Electromembrane extraction (EME) at low voltage (0-15V) of 29 different basic model drug substances was investigated. The drug substances with logP......Electromembrane extraction (EME) at low voltage (0-15V) of 29 different basic model drug substances was investigated. The drug substances with logP...

High School and Community College Astronomy Research Seminar

Science.gov (United States)

Genet, Russell M.; Boyce, Pat; Buchheim, Robert; Collins, Dwight; Freed, Rachel; Harshaw, Richard; Johnson, Jolyon; Kenney, John; Wallen, Vera

2016-06-01

For the past decade, Cuesta College has held an Astronomy Research Seminar. Teams of high school and community college students, with guidance from instructors and advanced amateur astronomers, have made astronomical observations, reduced their data, and submitted their research results to appropriate journals. A variety of projects, using modest-aperture telescopes equipped with low-cost instruments, are within reach of motivated students. These include double star astrometry, variable star photometry, and exoplanet transit timing. Advanced scientific knowledge and mastery of sophisticated experimental skills are not required when the students are immersed within a supportive community of practice. The seminar features self-paced, online learning units, an online textbook (the Small Telescope Astronomical Research Handbook), and a supportive website sponsored by the Institute for Student Astronomical Research (www.In4StAR.org). There are no prerequisites for the seminar. This encourages everyone—including underrepresented minorities and persons with disabilities—to participate. Each participant contributes as their time, talents, and experience dictates, thus replicating the modern, professional research team. Our spring 2015 seminar was the largest yet. Volunteer assistant instructors provided local in-person leadership, while the entire seminar met online for PowerPoint presentations on proposed projects and final research results. Some 37 students from eight schools finished the seminar as coauthors of 19 papers published in the January 2016 volume of the Journal of Double Star Observations. Robotic telescopes devoted to student research are coming online at both Concordia University and the Boyce Astronomical Robotic Observatory, as is a central online sever that will provide students with uniform, cost-free reduction and analysis software. The seminar has motivated many of its graduates to pursue careers in science, engineering, and medicine, often with

Overvoltage in low voltage systems due to mean voltage manoeuvres; Sobretensoes em sistemas de BT devidas a manobras na media tensao

Energy Technology Data Exchange (ETDEWEB)

Pazos, Francisco Jose; Amantegui, Javier; Ferrandis, Francisco; Barona, Amaya [Iberdrola, Madrid (Spain)

2008-04-15

The voltage interruption due to mean voltage maneuverers normal operation produces a transient type which is converted in a overvoltage on the low voltage circuit. Nevertheless to be considered a normal phenomena those over voltages have been pointed out as cause for damage in electric home appliances. What are the reasons? Inadequate protection or lack of immunity of the equipment?.

A Low-Power and Low-Voltage Power Management Strategy for On-Chip Micro Solar Cells

Directory of Open Access Journals (Sweden)

Ismail Cevik

2015-01-01

Full Text Available Fundamental characteristics of on-chip micro solar cell (MSC structures were investigated in this study. Several MSC structures using different layers in three different CMOS processes were designed and fabricated. Effects of PN junction structure and process technology on solar cell performance were measured. Parameters for low-power and low-voltage implementation of power management strategy and boost converter based circuits utilizing fractional voltage maximum power point tracking (FVMPPT algorithm were determined. The FVMPPT algorithm works based on the fraction between the maximum power point operation voltage and the open circuit voltage of the solar cell structure. This ratio is typically between 0.72 and 0.78 for commercially available poly crystalline silicon solar cells that produce several watts of power under typical daylight illumination. Measurements showed that the fractional voltage ratio is much higher and fairly constant between 0.82 and 0.85 for on-chip mono crystalline silicon micro solar cell structures that produce micro watts of power. Mono crystalline silicon solar cell structures were observed to result in better power fill factor (PFF that is higher than 74% indicating a higher energy harvesting efficiency.

Ultra Low-Voltage Energy Harvesting

Science.gov (United States)

2013-09-01

if in a solar battery charger the level of illumination were to drop due to cloud cover, the diode would prevent discharging of the battery when...the source voltage becomes lower than battery voltage. The drawback of a simple circuit like this is that once the source voltage is lower than the...longer charged when the battery voltage is above the OV setting. Figure 13. Block diagram of BQ25504 circuit . (From [10]) 18 THIS PAGE

INTERNATIONAL SUMMER STUDENT SEMINAR (3S, FROM IDEA TO REALIZATION

Directory of Open Access Journals (Sweden)

A. P. Karpik

2012-08-01

Full Text Available The article gives a spotlight on a three universities (Moscow State University of Geodesy and Cartography, Siberian State Academy of Geodesy, Wuhan University and ISPRS’ cooperation in organizing and holding summer student seminars for undergraduate, master, and PhD students of the universities specializing in photogrammetry, remote sensing, GIS, aerial and space cartography. Principles of topics of the seminar selection, lecture courses delivering and practical training as well as international joint team work on projects and their defence are described. The description of the basic stages of 3S implementation, and the goals of this sort of the international event is given.

Low-Cost Voltage Zero-Crossing Detector for AC-Grid Applications

Directory of Open Access Journals (Sweden)

Vorobyov Maxim

2014-10-01

Full Text Available Renewable energy sources and energy storage devices are becoming more popular. Some of them like small hydropower turbines, wind turbines and diesel generators produce AC voltage with different frequency and voltage than the main grid. For them power electronics converters are necessary. Power electronics converters presented in industry use two or three level energy conversion, although direct AC to AC converters exist, but one of the main problems is the switch commutation when current or voltage is crossing the zero point. Zero crossing sensors are used to solve this problem. They consist of current or voltage measurement unit and zero crossing detector. Different approaches are used for zero crossing: hardware or software. Hardware approach is simple but it has low precision. Software approach has high precision but it is complicated and expensive. In this paper a simple low cost high precision approach is presented. It takes all advantages from both approaches. While tested with two types of microcontrollers the precision of experimental measurement is 25 μs - 40 μs.

Using a Voltage Domain Programmable Technique for Low-Power Management Cell-Based Design

Directory of Open Access Journals (Sweden)

Ching-Hwa Cheng

2011-09-01

Full Text Available The Multi-voltage technique is an effective way to reduce power consumption. In the proposed cell-based voltage domain programmable (VDP technique, the high and low voltages applied to logic gates are programmable. The flexible voltage domain reassignment allows the chip performance and power consumption to be dynamically adjusted. In the proposed technique, the power switches possess the feature of flexible programming after chip manufacturing. This VDP method does not use an external voltage regulator to regulate the supply voltage level from outside of the chip but can be easily integrated within the design. This novel technique is proven by use of a video decoder test chip, which shows 55% and 61% power reductions compared to conventional single-Vdd and low-voltage designs, respectively. This power-aware performance adjusting mechanism shows great power reduction with a good power-performance management mechanism.

Suppression of the high-frequency disturbances in low-voltage circuits caused by disconnector operation in high-voltage open-air substations

Energy Technology Data Exchange (ETDEWEB)

Savic, M.S.

1986-07-01

The switching off and on of small capacitive currents charging busbar capacitances, connection conductors and open circuit breakers with disconnectors causes high-frequency transients in high-voltage networks. In low voltage circuits, these transient processes induce dangerous overvoltages for the electronic equipment in the substation. A modified construction of the disconnector with a damping resistor was investigated. Digital simulation of the transient process in a high-voltage network during the arcing period between the disconnector contacts with and without damping resistor were performed. A significant decrease of the arcing duration and the decrease of the electromagnetic field magnitude in the vicinity of the operating disconnector were noticed. In the low voltage circuit protected with the surge arrester, the overvoltage magnitude was not affected by the damping resistor due to the arrester protection effect.

Virtual Seminar Room

DEFF Research Database (Denmark)

Forchhammer, Søren Otto; Fosgerau, Anders; Hansen, Peter Søren Kirk

1999-01-01

The initial design considerations and research goals for an ATM network based virtual seminar room with 5 sites are presented.......The initial design considerations and research goals for an ATM network based virtual seminar room with 5 sites are presented....

Electronic Science Seminar

Directory of Open Access Journals (Sweden)

Geidarov P.Sh.

2015-09-01

Full Text Available The structure of electronic scientific seminar, which provides a high level of quality of the objectivity in the evaluation of scientific papers, including dissertations, is described. Conditions for the implementation of electronic scientific seminar are also considered.

Output Force Enhancement of Scratch Drive Actuator in Low-Voltage Region by Using Flexible Joint

Directory of Open Access Journals (Sweden)

Shawn CHEN

2010-04-01

Full Text Available Here a low-voltage scratch drive actuator (LVSDA is proposed by incorporating flexible joint into the conventional SDA to improve performance in low-voltage region. Experimental results show that, at the same total plate length of 80 mm and width of 65 mm, the proposed LVSDA can be actuated as low as 40 V, much lower than 80 V, the minimum required input voltage of the conventional SDA. From finite element analysis by CosmosWorks, yielding effect is found to be a critical factor. Before yielding, LVSDA can provide better performance than SDA at the same input voltage. However, the yielding stress in flexible joint would limit the achievable maximum output force in high-voltage region. By varying joint length, width, or location, LVSDA is shown to be operated in low-voltage region where the conventional SDA can not be operated, and can still provide comparable performance as SDA in high-voltage region.

High Efficiency Power Converter for Low Voltage High Power Applications

DEFF Research Database (Denmark)

Nymand, Morten

The topic of this thesis is the design of high efficiency power electronic dc-to-dc converters for high-power, low-input-voltage to high-output-voltage applications. These converters are increasingly required for emerging sustainable energy systems such as fuel cell, battery or photo voltaic based......, and remote power generation for light towers, camper vans, boats, beacons, and buoys etc. A review of current state-of-the-art is presented. The best performing converters achieve moderately high peak efficiencies at high input voltage and medium power level. However, system dimensioning and cost are often...

A 600kV 15mA Cockcroft-Walton high-voltage power supply with high stability and low-ripple voltage

International Nuclear Information System (INIS)

Su Tongling; Zhang Yimin; Chen Shangwen; Liu Yantong; Lv Huiyi; Liu Jiangtao

2006-01-01

A Cockcroft-Walton high-voltage power supply with high stability and low-ripple voltage has been developed. This power supply has been operated in a ns pulse neutron generator. The maximum non-load voltage is 600kV while the working voltage and load current are 550kV and 15mA, respectively. The tested results indicate that when the power supply is operated at 300kV, 6.7mA and the input voltage varies +/-10%, the long-term stability of the output voltage is S=(0.300-1.006)x10 -3 . The ripple voltage is δU P-P =6.2V at 300kV, 6.8-8.3mA and the ratio of δU P-P to the output voltage V H is δU P-P /V H =2.1x10 -5

Progression to surgery: online versus live seminar.

Science.gov (United States)

Miletics, Maureen; Claros, Leonardo; Stoltzfus, Jill; Davis, Terri; Chaar, Maher El

2018-03-01

The objective of this study was to evaluate progression to surgery rates for live and online seminar and assess weight loss outcome comparisons at 1-year postoperation. University Hospital Network, Allentown, PA, USA. The entry point into our program was an information seminar where prospective patients are educated about obesity, bariatric surgery, indications and contraindications, risks and benefits, and our center's process. Between January of 2009 and November of 2011, only live information seminars were offered. In November of 2011, we started offering an online information seminar to reach those who are unable to attend a live seminar. Tracking of live versus online seminar attendance was documented in our database. Between November 1, 2011 and September 30, 2015, 3484 people completed an information seminar. Of those, 2744 attendees came to a live seminar while 740 completed the online seminar. A significantly higher number of live seminar attendees, 78.1% (2144/2744) progressed to an office visit compared with online seminar attendees 66.5% (492/740), Ponline attendees (Ponline seminar, P = .65) and initial body mass index (46.3 ± 7.4 for live seminar versus 45.3 ± 7.1 for online seminar, P = .09) were very similar between the groups. Online seminar attendees' age (42.7 ± 12.1) was younger than that of the live seminar attendees' (47.3 ± 12.3) (P<.0001) but has little clinical value. Our results demonstrated that live seminar attendees are more likely to progress to surgery and therefore should continue to be offered. Copyright © 2018 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.

Successful application of Low Voltage Electron Microscopy to practical materials problems

International Nuclear Information System (INIS)

Bell, David C.; Mankin, Max; Day, Robert W.; Erdman, Natasha

2014-01-01

Low-voltage High-Resolution Electron Microscopy (LVHREM) has several advantages, including increased cross-sections for inelastic and elastic scattering, increased contrast per electron, decreased delocalization effects and reduced knock-on damage. Imaging at differing voltages has shown advantages for imaging materials that are knock-on damage sensitive. We show experimentally that different materials systems benefit from low voltage high-resolution microscopy. There are advantages for imaging single layer materials such as graphene at below the knock-on threshold; we present an example of imaging a graphene sheet at 40 kV. We have also examined mesoporous silica decorated with Pd nanoparticles and carbon black functionalized with Pd/Pt nanoparticles. In these cases we show that the lower voltage imaging maintains the structure of the surrounding matrix during imaging, whereas aberration correction provides the higher resolution for imaging the nanoparticle lattice. Perhaps surprisingly we show that zeolites damage preferentially by ionization effects (radiolysis). The current literature suggests that below incident energies of 40 kV the damage is mainly radiolitic, whereas at incident energies above 200 kV the knock-on damage and material sputtering will be the dominant effect. Our experimental observations support this conclusion and the effects we have observed at 40 kV are not indicative of knock-on damage. Other nanoscale materials such as thin silicon nanowires also benefit from lower voltage imaging. LVHREM imaging provides an excellent option to avoid beam damage to nanowires; our results suggest that LVHREM is suitable for nanowire-biological composites. Our experimental observations serve as a clear demonstration that even at 40 keV accelerating voltage, LVHREM can be used without inducing beam damage to locate dislocations and other crystalline defects, which may have adverse effects on nanowire device performance. Low voltage operation will likely

A high-efficiency low-voltage CMOS rectifier for harvesting energy in implantable devices.

Science.gov (United States)

Hashemi, S Saeid; Sawan, Mohamad; Savaria, Yvon

2012-08-01

We present, in this paper, a new full-wave CMOS rectifier dedicated for wirelessly-powered low-voltage biomedical implants. It uses bootstrapped capacitors to reduce the effective threshold voltage of selected MOS switches. It achieves a significant increase in its overall power efficiency and low voltage-drop. Therefore, the rectifier is good for applications with low-voltage power supplies and large load current. The rectifier topology does not require complex circuit design. The highest voltages available in the circuit are used to drive the gates of selected transistors in order to reduce leakage current and to lower their channel on-resistance, while having high transconductance. The proposed rectifier was fabricated using the standard TSMC 0.18 μm CMOS process. When connected to a sinusoidal source of 3.3 V peak amplitude, it allows improving the overall power efficiency by 11% compared to the best recently published results given by a gate cross-coupled-based structure.

Seminar on waste treatment and disposal

International Nuclear Information System (INIS)

Sneve, Malgorzata Karpow; Snihs, Jan Olof

1999-01-01

Leading abstract. A seminar on radioactive waste treatment and disposal was held 9 - 14 November 1998 in Oskarshamn, Sweden. The objective of the seminar was to exchange information on national and international procedures, practices and requirements for waste management. This information exchange was intended to promote the development of a suitable strategy for management of radioactive waste in Northwest Russia to be used as background for future co-operation in the region. The seminar focused on (1) overviews of international co-operation in the waste management field and national systems for waste management, (2) experiences from treatment of low- and intermediate-level radioactive waste, (3) the process of determining the options for final disposal of radioactive waste, (4) experiences from performance assessments and safety analysis for repositories intended for low- and intermediate level radioactive waste, (5) safety of storage and disposal of high-level waste. The seminar was jointly organised and sponsored by the Swedish Radiation Protection Institute (SSI), the Norwegian Radiation Protection Authority (NRPA), the Nordic Nuclear Safety Research (NKS) and the European Commission. A Russian version of the report is available. In brief, the main conclusions are: (1) It is the prerogative of the Russian federal Government to devise and implement a waste management strategy without having to pay attention to the recommendations of the meeting, (2) Some participants consider that many points have already been covered in existing governmental documents, (3) Norway and Sweden would like to see a strategic plan in order to identify how and where to co-operate best, (4) There is a rigorous structure of laws in place, based on over-arching environmental laws, (5) Decommissioning of submarines is a long and complicated task, (6) There are funds and a desire for continued Norway/Sweden/Russia co-operation, (7) Good co-operation is already taking place

Seminar on waste treatment and disposal

Energy Technology Data Exchange (ETDEWEB)

Sneve, Malgorzata Karpow; Snihs, Jan Olof

1999-07-01

Leading abstract. A seminar on radioactive waste treatment and disposal was held 9 - 14 November 1998 in Oskarshamn, Sweden. The objective of the seminar was to exchange information on national and international procedures, practices and requirements for waste management. This information exchange was intended to promote the development of a suitable strategy for management of radioactive waste in Northwest Russia to be used as background for future co-operation in the region. The seminar focused on (1) overviews of international co-operation in the waste management field and national systems for waste management, (2) experiences from treatment of low- and intermediate-level radioactive waste, (3) the process of determining the options for final disposal of radioactive waste, (4) experiences from performance assessments and safety analysis for repositories intended for low- and intermediate level radioactive waste, (5) safety of storage and disposal of high-level waste. The seminar was jointly organised and sponsored by the Swedish Radiation Protection Institute (SSI), the Norwegian Radiation Protection Authority (NRPA), the Nordic Nuclear Safety Research (NKS) and the European Commission. A Russian version of the report is available. In brief, the main conclusions are: (1) It is the prerogative of the Russian federal Government to devise and implement a waste management strategy without having to pay attention to the recommendations of the meeting, (2) Some participants consider that many points have already been covered in existing governmental documents, (3) Norway and Sweden would like to see a strategic plan in order to identify how and where to co-operate best, (4) There is a rigorous structure of laws in place, based on over-arching environmental laws, (5) Decommissioning of submarines is a long and complicated task, (6) There are funds and a desire for continued Norway/Sweden/Russia co-operation, (7) Good co-operation is already taking place.

EUROTHERM Seminar No. 18

CERN Document Server

Heggs, Peter; Butterworth, David

1992-01-01

The Eurotherm Committee was created in 1986 from member countries of the European Community. It has the purpose of organising and coordinating scientific events such as seminars and conferences in the thermal sciences. The series of Eurotherm Seminars established by the Committee has become a popular forum for high-level scientific and technical interchange of ideas in a wide range of specialist topics. While the presentation and publication of papers at the Seminars are encouraged, the primary aim is to stimulate discussion and liaison between specialist groups. The present Chairman of Eurotherm is Professor C.J. Hoogendoorn of the Technical University, Delft (Fax [NL] 15, 783251). Information on Mure Seminars is available from the Secretary, Keith Cornwell, Heriot-Watt University, Edinburgh (Fax [UK] 31, 451, 3129). This particular Seminar No. 18 on the Design and Operation of Heat Exchangers was the first one on this topic and was held at the Universitat der Bundeswehr Hamburg (University of the Federal Ar...

Low cost concepts to reduce the voltage ripple of the DC power supply

International Nuclear Information System (INIS)

Cheng, Y.; Liu, K.B.

1993-01-01

If the gain of current feedback is low, the short term stability of magnet power supply will be affected by a soft power line. Typically, the step-charge and the imbalance of the three phase power line cause the most serious voltage ripple. Usually, the voltage feedback with a coupling transformer is considered to reduce the voltage ripple. However, for the high current power supply, the space and cooling problem of the coupling transformer become inconvenient. In this paper, the authors suggest to use the toroidal core with the compensation winding, working like a DCCT, as the coupling transformer. Then, a high speed detector of the AC line level is developed. It restricts the voltage ripple passing to the coupling transformer. These methods have the advantage of small size, low power consumption and low cost

Application of Low Voltage High Resistance Grounding in Nuclear Power Plants

Directory of Open Access Journals (Sweden)

Choong-Koo Chang

2016-02-01

Full Text Available Most nuclear power plants now utilize solid grounded low voltage systems. For safety and reliability reasons, the low voltage (LV high resistance grounding (HRG system is also increasingly used in the pulp and paper, petroleum and chemical, and semiconductor industries. Fault detection is easiest and fastest with a solidly grounded system. However, a solidly grounded system has many limitations such as severe fault damage, poor reliability on essential circuits, and electrical noise caused by the high magnitude of ground fault currents. This paper will briefly address the strengths and weaknesses of LV grounding systems. An example of a low voltage HRG system in the LV system of a nuclear power plant will be presented. The HRG system is highly recommended for LV systems of nuclear power plants if sufficient considerations are provided to prevent nuisance tripping of ground fault relays and to avoid the deterioration of system reliability.

Surge currents and voltages at the low voltage power mains during lightning strike to a GSM tower

Energy Technology Data Exchange (ETDEWEB)

Markowska, Renata [Bialystok Technical University (Poland)], E-mail: remark@pb.edu.pl

2007-07-01

The paper presents the results of numerical calculations of lightning surge currents and voltages in the low voltage power mains system connected to a free standing GSM base station. Direct lightning strike to GSM tower was studied. The analysis concerned the current that flows to the transformer station through AC power mains, the potential difference between the grounding systems of the GSM and the transformer stations and the voltage differences between phase and PE conductors of the power mains underground cable at both the GSM and the transformer sides. The calculations were performed using a numerical program based on the electromagnetic field theory and the method of moments. (author)

Antenna Characterization for the JOLT Impulsive Radiator via Low-Voltage Measurements

Science.gov (United States)

Tyo, J. S.; Schoenberg, J. S. H.; Baum, C. E.; Prather, W. D.; Hackett, R.; Burger, J. W.; Farr, E. G.; Giri, D. V.; McLemore, D. P.

The JOLT system is a highly directive, impulse-like radiator. The antenna for JOLT is a 10-ft-diameter half-impulse radiating antenna (HIRA). JOLT was one of the first impulse radiating systems to employ a half IRA. For that reason, extensive measurements were made with a prototype, scale model HIRA in order to understand the performance of this class of antenna. In addition, a series of low-voltage antenna subsystem tests were performed with the full JOLT antenna before it was couple to the pulsed power and run at high voltage. The low-voltage measurements proved to be quite valuable, as an important manufacturing defect—a failure to mount the dish perpendicular to the ground plane—was identified and mitigated.

Improved detection of electrical activity with a voltage probe based on a voltage-sensing phosphatase.

Science.gov (United States)

Tsutsui, Hidekazu; Jinno, Yuka; Tomita, Akiko; Niino, Yusuke; Yamada, Yoshiyuki; Mikoshiba, Katsuhiko; Miyawaki, Atsushi; Okamura, Yasushi

2013-09-15

  One of the most awaited techniques in modern physiology is the sensitive detection of spatiotemporal electrical activity in a complex network of excitable cells. The use of genetically encoded voltage probes has been expected to enable such analysis. However, in spite of recent progress, existing probes still suffer from low signal amplitude and/or kinetics too slow to detect fast electrical activity. Here, we have developed an improved voltage probe named Mermaid2, which is based on the voltage-sensor domain of the voltage-sensing phosphatase from Ciona intestinalis and Förster energy transfer between a pair of fluorescent proteins. In mammalian cells, Mermaid2 permits ratiometric readouts of fractional changes of more than 50% over a physiologically relevant voltage range with fast kinetics, and it was used to follow a train of action potentials at frequencies of up to 150 Hz. Mermaid2 was also able to detect single action potentials and subthreshold voltage responses in hippocampal neurons in vitro, in addition to cortical electrical activity evoked by sound stimuli in single trials in living mice.

SAT-based personnel training for nuclear power plants. Proceedings of a seminar jointly organized under the technical cooperation programme (UKR/4/003) by the International Atomic Energy Agency, Goskomatom of Ukraine, South-Ukrainian NPP and held in Yuzhnoukrainsk, Ukraine, 10-14 April 1995. Working material

International Nuclear Information System (INIS)

1995-01-01

In 1995 the IAEA technical co-operation project ''Training for Safe Operation and Management of Nuclear Power Plants'' (UKR/4/003) has been started with the main goal to improve training systems and training infrastructures to ensure safe and reliable operation of nuclear power plants. As the first step of the project implementation, a seminar on introducing the Systematic Approach to Training for NPP personnel was recommended by the IAEA and G-24 mission on training as one of the primary training needs and priorities of Ukraine. The Seminar was held at the South-Ukrainian Nuclear Power Plant (SUNPP), Yuzhnoukrainsk, Ukraine from 10 to 13 April 1995 and was attended by 35 representatives from GOSKOMATOM, Ministry for Environment Protection and Nuclear Safety, OGPU, and all NPPs of Ukraine

Trap Healing for High-Performance Low-Voltage Polymer Transistors and Solution-Based Analog Amplifiers on Foil.

Science.gov (United States)

Pecunia, Vincenzo; Nikolka, Mark; Sou, Antony; Nasrallah, Iyad; Amin, Atefeh Y; McCulloch, Iain; Sirringhaus, Henning

2017-06-01

Solution-processed semiconductors such as conjugated polymers have great potential in large-area electronics. While extremely appealing due to their low-temperature and high-throughput deposition methods, their integration in high-performance circuits has been difficult. An important remaining challenge is the achievement of low-voltage circuit operation. The present study focuses on state-of-the-art polymer thin-film transistors based on poly(indacenodithiophene-benzothiadiazole) and shows that the general paradigm for low-voltage operation via an enhanced gate-to-channel capacitive coupling is unable to deliver high-performance device behavior. The order-of-magnitude longitudinal-field reduction demanded by low-voltage operation plays a fundamental role, enabling bulk trapping and leading to compromised contact properties. A trap-reduction technique based on small molecule additives, however, is capable of overcoming this effect, allowing low-voltage high-mobility operation. This approach is readily applicable to low-voltage circuit integration, as this work exemplifies by demonstrating high-performance analog differential amplifiers operating at a battery-compatible power supply voltage of 5 V with power dissipation of 11 µW, and attaining a voltage gain above 60 dB at a power supply voltage below 8 V. These findings constitute an important milestone in realizing low-voltage polymer transistors for solution-based analog electronics that meets performance and power-dissipation requirements for a range of battery-powered smart-sensing applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Radiological Protection in Nuclear Programmes in Latin America. Proceedings of a Regional Seminar

International Nuclear Information System (INIS)

1979-05-01

The growth of nuclear power projected both in the industrial and developing Member States of the IAEA raises many problems which can be solved only by international collaboration. The present regional seminar was organized with the objective of bringing together radiological protection specialists from the Latin American countries to discuss recent advances in radiological protection of nuclear workers, the population and the environment around nuclear installations.The seminar was organized by the IAEA in collaboration with the Government of Venezuela and took place on 21-25 November 1977 in Caracas. The participants came from 10 countries and the United Nations Development Organisation (UNDP), the Pan-American Health Organization (PAHO) and the Organization of American States (OAS) were represented. One of the main tasks of the seminar was the identification of those local or regional problems which might be solved through international collaboration. Therefore, all of these notes and proposals were reflected and summarized in the chapter entitled ''Notes and Recommendations of the Participants''. It was also felt that the seminar had an educational, or training character, as many participants expressed the view that great differences exist in the organizational, instrumental and legislative levels of the radiation protection facilities provided, and thus the seminar provided an opportunity to exchange views, information and ideas on these subjects. As this seminar proved to be very useful and successful, special emphasis was put on the recommendation that similar meetings should be organized every two or three years. In this report the papers are reproduced as presented at the sessions. As the discussions following the papers contained only a few further clarifications on the data presented, no detailed list of questions and answers is included in this report. One of the main tasks of the seminar was the identification of those local or

The Design of Operational Amplifier for Low Voltage and Low Current Sound Energy Harvesting System

Science.gov (United States)

Fang, Liew Hui; Rahim, Rosemizi Bin Abd; Isa, Muzamir; Idris Syed Hassan, Syed; Ismail, Baharuddin Bin

2018-03-01

The objective of this paper is to design a combination of an operational amplifier (op-amp) with a rectifier used in an alternate current (ac) to direct current (dc) power conversion. The op-amp was designed to specifically work at low voltage and low current for a sound energy harvesting system. The goal of the op-amp design with adjustable gain was to control output voltage based on the objectives of the experiment conducted. The op-amp was designed for minimum power dissipation performance, with the means of increasing the output current when receiving a large amount of load. The harvesting circuits which designed further improved the power output efficiency by shortening the fully charged time needed by a supercapacitor bank. It can fulfil the long-time power demands for low power device. Typically, a small amount of energy sources were converted to electricity and stored in the supercapacitor bank, which was built by 10 pieces of capacitors with 0.22 F each, arranged in parallel connection. The highest capacitance was chosen based on the characteristic that have the longest discharging time to support the applications of a supercapacitor bank. Testing results show that the op-amp can boost the low input ac voltage (∼3.89 V) to high output dc voltage (5.0 V) with output current of 30 mA and stored the electrical energy in a big supercapacitor bank having a total of 2.2 F, effectively. The measured results agree well with the calculated results.

Report on the national seminar on radioimmunoassays

International Nuclear Information System (INIS)

1979-01-01

Deliberations of the National Seminar on Radioimmunoassays (RIA) held at Bombay during 16-20 January 1978 are reported. Various aspects of the application of RIA techniques in India were discussed in the seminar. They included the basic requirements of RIA in India, the state-of-the-art of RIA in India, radiation protection in RIA, quality control of RIA, usefulness and limitations of RIA in clinical diagnosis and use of RIA in tropical infectious diseases. Difficulties encountered in the practice of RIA techniques in India were found to be mainly related to availability of 125 I, RIA kits, antisera and hormones. The need for establishing a centralised assay service for RIA was examined and it was concluded that such a step would be premature in the present situation. Recommendations made and guidelines spelt out deal with resources for RIA, research, referral assay service, training and information exchange and dissemination. (M.G.B.)

Magnetic lens apparatus for a low-voltage high-resolution electron microscope

Science.gov (United States)

Crewe, Albert V.

1996-01-01

A lens apparatus in which a beam of charged particles of low accelerating voltage is brought to a focus by a magnetic field, the lens being situated behind the target position. The lens comprises an electrically-conducting coil arranged around the axis of the beam and a magnetic pole piece extending along the axis of the beam at least within the space surrounded by the coil. The lens apparatus comprises the sole focusing lens for high-resolution imaging in a low-voltage scanning electron microscope.

Modular low-voltage electron beams

Science.gov (United States)

Berejka, Anthony J.; Avnery, Tovi; Carlson, Carl

2004-09-01

Modular, low-voltage systems have simplified electron beam (EB) technology for industrial uses and for research and development. Modular EB units are produced in quantity as sealed systems that are evacuated at the factory eliminating the need for vacuum pumps at the point of use. A simple plug-out—plug-in method of replacement eliminates downtime for servicing. Use of ultra-thin beam windows (innovative design to extract and spread the beam (enabling systems to be placed adjacent to each other to extend beam width) and touch-screen computer controls, combine for ease of use and electrical transfer efficiency at voltages that can be varied between 80 and 150 kV and with high beam currents (up to 40 mA across the 25 cm window). These electron systems are available in three widths, the standard 25 cm and new 5 and 40 cm beams. Traditional uses in the graphic arts and coatings areas as well as uses in surface sterilization have found these compact, lightweight (approximately 15 kg) modular beams of interest. Units have been configured around complex shapes to enable three-dimensional surface curing (as for coatings on aluminum tubing) to be achieved at high production rates. Details of the beam construction and some industrial uses are discussed.

Left atrial low-voltage areas predict atrial fibrillation recurrence after catheter ablation in patients with paroxysmal atrial fibrillation.

Science.gov (United States)

Masuda, Masaharu; Fujita, Masashi; Iida, Osamu; Okamoto, Shin; Ishihara, Takayuki; Nanto, Kiyonori; Kanda, Takashi; Tsujimura, Takuya; Matsuda, Yasuhiro; Okuno, Shota; Ohashi, Takuya; Tsuji, Aki; Mano, Toshiaki

2018-04-15

Association between the presence of left atrial low-voltage areas and atrial fibrillation (AF) recurrence after pulmonary vein isolation (PVI) has been shown mainly in persistent AF patients. We sought to compare the AF recurrence rate in paroxysmal AF patients with and without left atrial low-voltage areas. This prospective observational study included 147 consecutive patients undergoing initial ablation for paroxysmal AF. Voltage mapping was performed after PVI during sinus rhythm, and low-voltage areas were defined as regions where bipolar peak-to-peak voltage was low-voltage areas after PVI were observed in 22 (15%) patients. Patients with low-voltage areas were significantly older (72±6 vs. 66±10, plow-voltage areas than without (36% vs. 6%, pLow-voltage areas were independently associated with AF recurrence even after adjustment for the other related factors (Hazard ratio, 5.89; 95% confidence interval, 2.16 to 16.0, p=0.001). The presence of left atrial low-voltage areas after PVI predicts AF recurrence in patients with paroxysmal AF as well as in patients with persistent AF. Copyright © 2017 Elsevier B.V. All rights reserved.

Symmetric low-voltage powering system for relativistic electronic devices

International Nuclear Information System (INIS)

Agafonov, A.V.; Lebedev, A.N.; Krastelev, E.G.

2005-01-01

A special driver for double-sided powering of relativistic magnetrons and several methods of localized electron flow forming in the interaction region of relativistic magnetrons are proposed and discussed. Two experimental installations are presented and discussed. One of them is designed for laboratory research and demonstration experiments at a rather low voltage. The other one is a prototype of a full-scale installation for an experimental research at relativistic levels of voltages on the microwave generation in the new integrated system consisting of a relativistic magnetron and symmetrical induction driver

Input Stage for Low-Voltage, Low-Noise Preamplifiers Based on a Floating-Gate MOS Transistor

DEFF Research Database (Denmark)

Igor, Mucha

1997-01-01

A novel input stage for low-voltage, low-noise preamplifiers for integrated capacitive sensors is presented. The input stage of the preamplifier employs floating-gate MOS transistors which are capable of storing the operation point of the input stage over several years without any severe degradat......A novel input stage for low-voltage, low-noise preamplifiers for integrated capacitive sensors is presented. The input stage of the preamplifier employs floating-gate MOS transistors which are capable of storing the operation point of the input stage over several years without any severe...... degradation of the performance of the circuit and without the need for a repeating programming. In this way the noise originating from any resistance previously used for the definition of the operating point is avoided completely and, moreover, by avoiding the input high-pass filter both the saturation...

A high voltage ratio and low ripple interleaved DC-DC converter for fuel cell applications.

Science.gov (United States)

Chang, Long-Yi; Chao, Kuei-Hsiang; Chang, Tsang-Chih

2012-01-01

This paper proposes a high voltage ratio and low ripple interleaved boost DC-DC converter, which can be used to reduce the output voltage ripple. This converter transfers the low DC voltage of fuel cell to high DC voltage in DC link. The structure of the converter is parallel with two voltage-doubler boost converters by interleaving their output voltages to reduce the voltage ripple ratio. Besides, it can lower the current stress for the switches and inductors in the system. First, the PSIM software was used to establish a proton exchange membrane fuel cell and a converter circuit model. The simulated and measured results of the fuel cell output characteristic curve are made to verify the correctness of the established simulation model. In addition, some experimental results are made to validate the effectiveness in improving output voltage ripple of the proposed high voltage ratio interleaved boost DC-DC converters.

For information: A Series of Seminars about NICE Environment during May / June 2004

CERN Multimedia

2004-01-01

Recently deployed at CERN, Windows XP and Office 2003 offer new functionalities. IT/IS Group has prepared a series of seminars to both introduce the CERN NICE environment to beginners and also to show how to benefit from the advanced features offered by the new versions of Windows and Office. Particular attention will be paid to Collaborative Tasks, like reviewing a document, planning a meeting and to Mobile Computing like working offline, remotely accessing CERN resources, etc.. Seminars planned this week are: Editer des sites Web avec Frontpage 2003 (FR), Tuesday 1st of June, 14:30. Créer des documents bureautiques avec Windows Word 2003 et Excel 2003 (FR), Thursday 3rd of June, 14:30. The seminars will take place in the IT Auditorium (bldg. 31, 3-005) and last for about one hour plus questions. No registration is necessary. More information is available at http://cern.ch/Win/Seminars/Tutorials. Interested users can also have a look to courses offered by CERN Technical Training, at http://cern.ch/humanr...

Design of Low Voltage Low Power CMOS OP-AMPS with Rail-to-Rail Input/Output Swing

OpenAIRE

Gopalaiah, SV; Shivaprasad, AP; Panigrahi, Sukanta K

2004-01-01

A novel input and output biasing circuit to extend the input common mode (CM) voltage range and the output swing to rail-to-rail in a low voltage op-amp in standard CMOS technology is presented. The input biasing circuit uses a Switched Capacitor Based Attenuator (SCBA) approach to establish rail-to-rail common mode input voltage range. And the output biasing circuit uses an Output Driver (OD), with floating bias to give the rail-to-rail swing at output stage. Three different OD schemes in op...

A Low-input-voltage Wireless Power Transfer for Biomedical Implants

DEFF Research Database (Denmark)

Jiang, Hao; Bai, Kangjun; Zhu, Weijie

2015-01-01

Wireless power transfer is an essential technology to increase implants' longevity. A pair of inductivelycoupled coils operating at radio-frequency is extensively used to deliver electrical power to implants wirelessly. In this system, a power conditioning circuit is required convert the induced...... in the rectifier for the efficient AC to DC conversion. This requirement results in larger coil size, shorter operating distance or more stringent geometrical alignment between the two coils. In this paper, a low-input-voltage wireless power transfer has been demonstrated. In this system, the opencircuit voltage...... time-varying AC power harvested by the receiving coil to a stable DC power that is needed for powering circuits and sensors. Most existing power conditioning circuits require the induced voltage of the receiving coil to be significantly higher than the turn-on voltage of the diodes used...

Demand Response in Low Voltage Distribution Networks with High PV Penetration

DEFF Research Database (Denmark)

Nainar, Karthikeyan; Pokhrel, Basanta Raj; Pillai, Jayakrishnan Radhakrishna

2017-01-01

the required flexibility from the electricity market through an aggregator. The optimum demand response enables consumption of maximum renewable energy within the network constraints. Simulation studies are conducted using Matlab and DigSilent Power factory software on a Danish low-voltage distribution system......In this paper, application of demand response to accommodate maximum PV power in a low-voltage distribution network is discussed. A centralized control based on model predictive control method is proposed for the computation of optimal demand response on an hourly basis. The proposed method uses PV...

Dose-rate effects of low-dropout voltage regulator at various biases

International Nuclear Information System (INIS)

Wang Yiyuan; Zheng Yuzhan; Gao Bo; Chen Rui; Fei Wuxiong; Lu Wu; Ren Diyuan

2010-01-01

A low-dropout voltage regulator, LM2941, was irradiated by 60 Co γ-rays at various dose rates and biases for investigating the total dose and dose rate effects. The radiation responses show that the key electrical parameters, including its output and dropout voltage, and the maximum output current, are sensitive to total dose and dose rates, and are significantly degraded at low dose rate and zero bias. The integrated circuits damage change with the dose rates and biases, and the dose-rate effects are relative to its electric field. (authors)

Coordinated Low Voltage Ride through strategies for Permanent Magnet Direct Drive Synchronous Generators

Directory of Open Access Journals (Sweden)

Zhang Ge

2016-01-01

Full Text Available By analyzing the mechanism of the low voltage ride through on the permanent magnet direct drive synchronous wind power generating units, this paper proposes a coordinated control strategy for permanent magnet synchronous generator. In order to avoid over speed operation of the generation units, over voltage on DC capacitor and over current on convert, the improved pitch angle control and inverter control are used. When the grid voltage drops, the captured wind power is cut down by the variable pitch system, which limits the speed of the generator, the generator side converter keeps the DC capacitor voltage stabile; and the grid side converter provides reactive power to the grid to help the grid voltage recover. The control strategy does not require any additional hardware equipment, with existing control means, the unit will be able to realize low voltage ride through. Finally, based on Matlab/Simulink to build permanent magnet direct drive wind power generation system, the simulation results verify the correctness and effectiveness of the control strategy.

Low Voltage, High-Q SOI MEMS Varactors for RF Applications

DEFF Research Database (Denmark)

Yalcinkaya, Arda Deniz; Jensen, Søren; Hansen, Ole

2003-01-01

A micro electromechanical tunable capacitor with a low control voltage, a wide tuning range and high electrical quality factor is presented with detailed characterizations. A 50μm thick single-crystalline silicon layer was etched using deep reactive ion etching (DRIE) for obtaining high-aspect ra...... is a suitable passive component to be used in band-pass filtering, voltage controlled oscillator or impedance matching applications on the very high frequency(VHF) and ultra high frequency (UHF) bands....

Reproducible low-voltage resistive switching in a low-initial-resistance Pr0.7Ca0.3MnO3 junction

International Nuclear Information System (INIS)

Li Songlin; Gang Jianlei; Li Jie; Chu Haifeng; Zheng Dongning

2008-01-01

Current-voltage (I-V) characteristics are investigated in a low-initial-resistance Ag/Pr 0.7 Ca 0.3 MnO 3 /Pt sandwich structure. It is found that the junction can show stable low and high resistance states in ±0.3 V voltage sweeping cycles. The set and reset voltage values are, respectively, +0.1 V and -0.2 V, which are very low as compared with those reported previously. Furthermore, the I-V curves in both resistance states exhibit rather linear behaviour, without any signature of metal/insulator interface effects. This implies that the Schottky interface mechanism might not be an indispensable factor for the colossal electroresistance effect. The origin of low switching voltages is attributed to the reduced effective distance for electric field action due to the sufficient oxygen content of the PCMO layer. The underlying physics is discussed in terms of the filament network model together with the field-induced oxygen vacancy motion model

Admissibility of building cost subsidy in the power grid above the low voltage level

International Nuclear Information System (INIS)

Foerster, Sven

2015-01-01

Electricity networks are essential to the provision of electrical power to businesses and individuals. In particular for manufacturing businesses a connection to the grid above the low-voltage level is often useful. Network operators demand a subsidy for the new connection and for the change to a higher network level under the auspices of construction cost. The power network market above the low-voltage level is a natural monopoly. This leaves consumers looking for a connection to the power grid with no possibility to select among different network operators. Construction cost subsidies are not regulated by law above the low voltage level. The lack of legal regulation and the natural monopoly above the low-voltage level affect the balance of power between network operators and system users. The lawfulness of the construction cost subsidies, the prerequisites for their demand and a review of the calculation models (Leistungspreismodell, 2-Ebenen-Modell) as well as a proposal for a reform of this system form the subject of this work.

Wood pellet seminar

International Nuclear Information System (INIS)

Aarniala, M.; Puhakka, A.

2001-01-01

The objective of the wood pellet seminar, arranged by OPET Finland and North Karelia Polytechnic, was to deliver information on wood pellets, pellet burners and boilers, heating systems and building, as well as on the activities of wood energy advisors. The first day of the seminar consisted of presentations of equipment and products, and of advisory desks for builders. The second day of the seminar consisted of presentations held by wood pellet experts. Pellet markets, the economy and production, the development of the pellet markets and their problems (in Austria), the economy of heating of real estates by different fuel alternatives, the production, delivery and marketing of wood pellets, the utilization of wood pellet in different utilization sites, the use of wood pellets in detached houses, pellet burners and fireplaces, and conversion of communal real estate houses to use wood pellets were discussed in the presentations. The presentations held in the third day discussed the utilization of wood pellets in power plants, the regional promotion of the production and the use of pellets. The seminar consisted also of visits to pellet manufacturing plant and two pellet burning heating plants

Modular low-voltage electron beams

International Nuclear Information System (INIS)

Berejka, A.J.; Avnery, Tovi; Carlson, Carl

2004-01-01

Modular, low-voltage systems have simplified electron beam (EB) technology for industrial uses and for research and development. Modular EB units are produced in quantity as sealed systems that are evacuated at the factory eliminating the need for vacuum pumps at the point of use. A simple plug-out--plug-in method of replacement eliminates downtime for servicing. Use of ultra-thin beam windows (<10 μm of titanium foil), solid-state 19 in. (48 cm) rack-mounted power supplies, an innovative design to extract and spread the beam (enabling systems to be placed adjacent to each other to extend beam width) and touch-screen computer controls, combine for ease of use and electrical transfer efficiency at voltages that can be varied between 80 and 150 kV and with high beam currents (up to 40 mA across the 25 cm window). These electron systems are available in three widths, the standard 25 cm and new 5 and 40 cm beams. Traditional uses in the graphic arts and coatings areas as well as uses in surface sterilization have found these compact, lightweight (approximately 15 kg) modular beams of interest. Units have been configured around complex shapes to enable three-dimensional surface curing (as for coatings on aluminum tubing) to be achieved at high production rates. Details of the beam construction and some industrial uses are discussed

Modular low-voltage electron emitters

International Nuclear Information System (INIS)

Berejka, Anthony J.

2005-01-01

Modular, low-voltage electron emitters simplify electron beam (EB) technology for many industrial uses and for research and development. Modular electron emitters are produced in quantity as sealed systems that are evacuated at the factory, eliminating the need for vacuum pumps at the point of use. A plug-out-plug-in method of replacement facilitates servicing. By using an ultra-thin 6-7 μm titanium foil window, solid-state power supplies, an innovative design to extract and spread the beam (enabling systems to be placed adjacent to each other to extend beam width) and touch-screen computer controls, these modular units combine ease of use and electrical transfer efficiency at voltages that can be varied between 80 kV and 150 kV with beam currents up to 40 mA per 25 cm across the beam window. These new devices have been made in three widths: 5 cm, 25 cm, and 40 cm. Details of the beam construction and illustrations of industrial uses will be presented. Traditional uses in the graphic arts and coatings areas have welcomed this modular technology as well as uses for surface sterilization. Being compact and lightweight (∼15 kg/emitter), these modular beams have been configured around complex shapes to achieve three-dimensional surface curing at high production rates

Modular low-voltage electron emitters

Science.gov (United States)

Berejka, Anthony J.

2005-12-01

Modular, low-voltage electron emitters simplify electron beam (EB) technology for many industrial uses and for research and development. Modular electron emitters are produced in quantity as sealed systems that are evacuated at the factory, eliminating the need for vacuum pumps at the point of use. A plug-out-plug-in method of replacement facilitates servicing. By using an ultra-thin 6-7 μm titanium foil window, solid-state power supplies, an innovative design to extract and spread the beam (enabling systems to be placed adjacent to each other to extend beam width) and touch-screen computer controls, these modular units combine ease of use and electrical transfer efficiency at voltages that can be varied between 80 kV and 150 kV with beam currents up to 40 mA per 25 cm across the beam window. These new devices have been made in three widths: 5 cm, 25 cm, and 40 cm. Details of the beam construction and illustrations of industrial uses will be presented. Traditional uses in the graphic arts and coatings areas have welcomed this modular technology as well as uses for surface sterilization. Being compact and lightweight (∼15 kg/emitter), these modular beams have been configured around complex shapes to achieve three-dimensional surface curing at high production rates.

GammaSem Proceedings. A Nordic seminar for users of gamma spectrometry

Energy Technology Data Exchange (ETDEWEB)

Straalberg, E. (ed.) (Institute for Energy Technolgy (Norway)); Berg, K. (National Institute of Radiation Protection (Denmark)); Dowdall, M. (Norwegian Radiation Protection Authority (Norway)) (and others)

2010-11-15

The project GammaSem was proposed to the NKS in 2008. The aim of the project was to arrange two seminars for users of gamma spectrometry, in 2009 and 2010. The seminars were meant to provide a forum for discussions and sharing of information on practical issues concerning gamma spectrometry and initiate a network of gamma spectrometry users in the Nordic countries. Such a Nordic network should strengthen the collaboration between laboratories and improve all participants' competence in practical gamma spectrometry. Both seminars' focus was practical challenges met by the users themselves, rather than theoretical matters. Scientists and users of gamma spectrometry from all five Nordic countries were invited to the seminar, as well as scientist from the Baltic countries. A total of 65 people signed up for GammaSem 2010; representing 30 different universities, commercial companies, research institutes and authorities. The working group concept as presented at last year's GammaSem, has not worked out as intended. The reason for this is probably because most of the laboratories that signed up to join the working groups, signed up because they wanted to learn more about the different subjects. In combination with the fact that no funding was made available for the working groups, it was difficult to establish goals on what to achieve. None of the working groups applied for funding from the NKS (or elsewhere) to establish separate projects. There is a big need for more cooperation and for training within the field of gamma spectrometry. This fact has been proved through these two seminars, both by the many different topics that have been discussed, but also by the huge interest for participating in the suggested series of workshop. The GammaSem seminars have thus provided a much welcomed starting point for a broader Nordic collaboration. (Author)

GammaSem Proceedings. A Nordic seminar for users of gamma spectrometry

International Nuclear Information System (INIS)

Straelberg, E.; Berg, K.; Dowdall, M.

2010-11-01

The project GammaSem was proposed to the NKS in 2008. The aim of the project was to arrange two seminars for users of gamma spectrometry, in 2009 and 2010. The seminars were meant to provide a forum for discussions and sharing of information on practical issues concerning gamma spectrometry and initiate a network of gamma spectrometry users in the Nordic countries. Such a Nordic network should strengthen the collaboration between laboratories and improve all participants' competence in practical gamma spectrometry. Both seminars' focus was practical challenges met by the users themselves, rather than theoretical matters. Scientists and users of gamma spectrometry from all five Nordic countries were invited to the seminar, as well as scientist from the Baltic countries. A total of 65 people signed up for GammaSem 2010; representing 30 different universities, commercial companies, research institutes and authorities. The working group concept as presented at last year's GammaSem, has not worked out as intended. The reason for this is probably because most of the laboratories that signed up to join the working groups, signed up because they wanted to learn more about the different subjects. In combination with the fact that no funding was made available for the working groups, it was difficult to establish goals on what to achieve. None of the working groups applied for funding from the NKS (or elsewhere) to establish separate projects. There is a big need for more cooperation and for training within the field of gamma spectrometry. This fact has been proved through these two seminars, both by the many different topics that have been discussed, but also by the huge interest for participating in the suggested series of workshop. The GammaSem seminars have thus provided a much welcomed starting point for a broader Nordic collaboration. (Author)

Low-Voltage Solution-Processed Hybrid Light-Emitting Transistors.

Science.gov (United States)

Chaudhry, Mujeeb Ullah; Tetzner, Kornelius; Lin, Yen-Hung; Nam, Sungho; Pearson, Christopher; Groves, Chris; Petty, Michael C; Anthopoulos, Thomas D; Bradley, Donal D C

2018-05-21

We report the development of low operating voltages in inorganic-organic hybrid light-emitting transistors (HLETs) based on a solution-processed ZrO x gate dielectric and a hybrid multilayer channel consisting of the heterojunction In 2 O 3 /ZnO and the organic polymer "Super Yellow" acting as n- and p-channel/emissive layers, respectively. Resulting HLETs operate at the lowest voltages reported to-date (<10 V) and combine high electron mobility (22 cm 2 /(V s)) with appreciable current on/off ratios (≈10 3 ) and an external quantum efficiency of 2 × 10 -2 % at 700 cd/m 2 . The charge injection, transport, and recombination mechanisms within this HLET architecture are discussed, and prospects for further performance enhancement are considered.

Seminar series on Safety matters

CERN Multimedia

HSE

2010-01-01

The HSE - Occupational Health & Safety and Environmental Protection - Unit is starting a seminar series on Safety matters. The aim is to invite colleagues from Universities, Industries or Government Agencies to share their experience. The seminars will take place in intervals of several months. Part of the Seminars will be held in the form of a Forum where participants can discuss and share views with persons who manage, teach or research Safety matters elsewhere. You are invited to the first Safety Seminar on 22nd September 2010 at 10h00 in building 40 S2 A1 "Salle Andersson" L’Ecole Polytechnique Fédérale de Lausanne (EPFL) will present the way safety is managed in their research institution. Some aspects of research in physics and chemical laboratories will also be presented. The seminar will be given by Dr Thierry Meyer, Head of OHS at FSB-EPFL and Dr Amela Groso, responsible for the safety of the physics institutes

Digital-circuit analysis of short-gate tunnel FETs for low-voltage applications

International Nuclear Information System (INIS)

Zhuge, Jing; Huang, Ru; Wang, Yangyuan; Verhulst, Anne S; Vandenberghe, William G; Dehaene, Wim; Groeseneken, Guido

2011-01-01

This paper investigates the potential of tunnel field-effect transistors (TFETs), with emphasis on short-gate TFETs, by simulation for low-power digital applications having a supply voltage lower than 0.5 V. A transient study shows that the tunneling current has a negligible contribution in charging and discharging the gate capacitance of TFETs. In spite of a higher resistance region in the short-gate TFET, the gate (dis)charging speed still meets low-voltage application requirements. A circuit analysis is performed on short-gate TFETs with different materials, such as Si, Ge and heterostructures in terms of voltage overshoot, delay, static power, energy consumption and energy delay product (EDP). These results are compared to MOSFET and full-gate TFET performance. It is concluded that short-gate heterostructure TFETs (Ge–source for nTFET, In 0.6 Ga 0.4 As–source for pTFET) are promising candidates to extend the supply voltage to lower than 0.5 V because they combine the advantage of a low Miller capacitance, due to the short-gate structures, and strong drive current in TFETs, due to the narrow bandgap material in the source. At a supply voltage of 0.4 V and for an EOT and channel length of 0.6 nm and 40 nm, respectively, a three-stage inverter chain based on short-gate heterostructure TFETs saves 40% energy consumption per cycle at the same delay and shows 60%–75% improvement of EDP at the same static power, compared to its full-gate counterpart. When compared to the MOSFET, better EDP can be achieved in the heterostructure TFET especially at low static power consumption

The degradation diagnosis of low voltage cables used at nuclear power plants

International Nuclear Information System (INIS)

Yamamoto, Toshio; Ashida, Tetsuya; Ikeda, Takeshi; Yasuhara, Takeshi; Takechi, Kei; Araki, Shogo

2001-01-01

Low voltage cables which have been used for the supply of electric power and the propagation of control signals in nuclear power plants must be sound for safe and stable operation. The long use of nuclear power plants has been reviewed, and the degradation diagnosis to estimate the soundness of low voltage cables has been emphasized. Mitsubishi Cable Industries has established a degradation diagnosis method of cables which convert the velocity of ultrasonic wave in the surface layer of the cable insulation or jacket into breaking elongation, and has developed a degradation diagnosis equipment of low voltage cables used at nuclear power plants in cooperation with Mitsubishi Heavy Industries. This equipment can be moved by an ultrasonic probe by sequential control and measure the ultrasonic velocity automatically. It is capable of a fast an sensitive diagnosis of the cables. We report the outline of this degradation diagnosis equipment and an example of the adaptability estimation at an actual nuclear power plant. (author)

Dual patch voltage clamp study of low membrane resistance astrocytes in situ.

Science.gov (United States)

Ma, Baofeng; Xu, Guangjin; Wang, Wei; Enyeart, John J; Zhou, Min

2014-03-17

Whole-cell patch clamp recording has been successfully used in identifying the voltage-dependent gating and conductance properties of ion channels in a variety of cells. However, this powerful technique is of limited value in studying low membrane resistance cells, such as astrocytes in situ, because of the inability to control or accurately measure the real amplitude of command voltages. To facilitate the study of ionic conductances of astrocytes, we have developed a dual patch recording method which permits membrane current and membrane potential to be simultaneously recorded from astrocytes in spite of their extraordinarily low membrane resistance. The utility of this technique is demonstrated by measuring the voltage-dependent activation of the inwardly rectifying K+ current abundantly expressed in astrocytes and multiple ionic events associated with astrocytic GABAA receptor activation. This protocol can be performed routinely in the study of astrocytes. This method will be valuable for identifying and characterizing the individual ion channels that orchestrate the electrical activity of low membrane resistance cells.

Voltage control in Z-source inverter using low cost microcontroller for undergraduate approach

Science.gov (United States)

Zulkifli, Shamsul Aizam; Sewang, Mohd Rizal; Salimin, Suriana; Shah, Noor Mazliza Badrul

2017-09-01

This paper is focussing on controlling the output voltage of Z-Source Inverter (ZSI) using a low cost microcontroller with MATLAB-Simulink that has been used for interfacing the voltage control at the output of ZSI. The key advantage of this system is the ability of a low cost microcontroller to process the voltage control blocks based on the mathematical equations created in MATLAB-Simulink. The Proportional Integral (PI) control equations are been applied and then, been downloaded to the microcontroller for observing the changes on the voltage output regarding to the changes on the reference on the PI. The system has been simulated in MATLAB and been verified with the hardware setup. As the results, the Raspberry Pi and Arduino that have been used in this work are able to respond well when there is a change of ZSI output. It proofed that, by applying/introducing this method to student in undergraduate level, it will help the student to understand more on the process of the power converter combine with a control feedback function that can be applied at low cost microcontroller.

Biased low differential input impedance current receiver/converter device and method for low noise readout from voltage-controlled detectors

Science.gov (United States)

Degtiarenko, Pavel V [Williamsburg, VA; Popov, Vladimir E [Newport News, VA

2011-03-22

A first stage electronic system for receiving charge or current from voltage-controlled sensors or detectors that includes a low input impedance current receiver/converter device (for example, a transimpedance amplifier), which is directly coupled to the sensor output, a source of bias voltage, and the device's power supply (or supplies), which use the biased voltage point as a baseline.

LED Current Balance Using a Variable Voltage Regulator with Low Dropout vDS Control

Directory of Open Access Journals (Sweden)

Hung-I Hsieh

2017-02-01

Full Text Available A cost-effective light-emitting diode (LED current balance strategy using a variable voltage regulator (VVR with low dropout vDS control is proposed. This can regulate the multiple metal-oxide-semiconductor field-effect transistors (MOSFETs of the linear current regulators (LCR, maintaining low dropout vDS on the flat vGS-characteristic curves and making all drain currents almost the same. Simple group LCRs respectively loaded with a string LED are employed to implement the theme. The voltage VVdc from a VVR is synthesized by a string LED voltage NvD, source voltage vR, and a specified low dropout vDS = VQ. The VVdc updates instantly, through the control loop of the master LCR, which means that all slave MOSFETs have almost the same biases on their flat vGS-characteristic curves. This leads to all of the string LED currents being equal to each other, producing an almost even luminance. An experimental setup with microchip control is built to verify the estimations. Experimental results show that the luminance of all of the string LEDs are almost equal to one another, with a maximum deviation below 1% during a wide dimming range, while keeping all vDS of the MOSFETs at a low dropout voltage, as expected.

A Low-Voltage Ride-Through Control Strategy for Three-Phase Grid-Connected PV Systems

DEFF Research Database (Denmark)

Afshari, Ehsan; Farhangi, Babak; Yang, Yongheng

2017-01-01

similar variations in the dc-link voltage of conventional two-stage PV inverters. In such systems with an electrolytic capacitor in the dc-link, the oscillations of the dc-link voltage with DGF can deteriorate the capacitor lifetime, and thus the entire system. The proposed Low-Voltage Ride-Through (LVRT...

Arbejdspapir til Thesis-seminar

DEFF Research Database (Denmark)

Damkjaer, Maja Sonne

2014-01-01

Arbejdspapir til Thesis-seminar afholdt ved Forskningsseminar i Forskningsprogrammet: Medier, Kommunikation og Samfund, Institut for Æstetik og Kommunikation, Aarhus Universitet. Afhandlingens teoretiske afsnit.......Arbejdspapir til Thesis-seminar afholdt ved Forskningsseminar i Forskningsprogrammet: Medier, Kommunikation og Samfund, Institut for Æstetik og Kommunikation, Aarhus Universitet. Afhandlingens teoretiske afsnit....

Low Wind Speed Turbine Project Phase II: The Application of Medium-Voltage Electrical Apparatus to the Class of Variable Speed Multi-Megawatt Low Wind Speed Turbines; 15 June 2004--30 April 2005

Energy Technology Data Exchange (ETDEWEB)

Erdman, W.; Behnke, M.

2005-11-01

Kilowatt ratings of modern wind turbines have progressed rapidly from 50 kW to 1,800 kW over the past 25 years, with 3.0- to 7.5-MW turbines expected in the next 5 years. The premise of this study is simple: The rapid growth of wind turbine power ratings and the corresponding growth in turbine electrical generation systems and associated controls are quickly making low-voltage (LV) electrical design approaches cost-ineffective. This report provides design detail and compares the cost of energy (COE) between commercial LV-class wind power machines and emerging medium-voltage (MV)-class multi-megawatt wind technology. The key finding is that a 2.5% reduction in the COE can be achieved by moving from LV to MV systems. This is a conservative estimate, with a 3% to 3.5% reduction believed to be attainable once purchase orders to support a 250-turbine/year production level are placed. This evaluation considers capital costs as well as installation, maintenance, and training requirements for wind turbine maintenance personnel. Subsystems investigated include the generator, pendant cables, variable-speed converter, and padmount transformer with switchgear. Both current-source and voltage-source converter/inverter MV topologies are compared against their low-voltage, voltage-source counterparts at the 3.0-, 5.0-, and 7.5-MW levels.

RJH seminar

International Nuclear Information System (INIS)

2003-01-01

This document gathers the slides that were presented at the Jules Horowitz reactor (RJH) seminar on the 14 january 2003. RJH seminars take place regularly in order to give an overview and make a point of the advancement of the RJH project. The contributions can be classed into 6 topics: 1) historical review of the RJH project, 2) RJH design and site studies, 3) irradiation devices, 4) development and qualification of codes to design RJH (Horus-3d, Sultan), 5) materials (aluminium alloys, mechanical resistance, corrosion and welding), and 6) UMo nuclear fuel (specifications, fabrication and reprocessing). (A.C.)

Minimum-Voltage Vector Injection Method for Sensorless Control of PMSM for Low-Speed Operations

DEFF Research Database (Denmark)

Xie, Ge; Lu, Kaiyuan; Kumar, Dwivedi Sanjeet

2016-01-01

In this paper, a simple signal injection method is proposed for sensorless control of PMSM at low speed, which ideally requires one voltage vector only for position estimation. The proposed method is easy to implement resulting in low computation burden. No filters are needed for extracting...... may also be further developed to inject two opposite voltage vectors to reduce the effects of inverter voltage error on the position estimation accuracy. The effectiveness of the proposed method is demonstrated by comparing with other sensorless control method. Theoretical analysis and experimental...

Distributed Control to Ensure Proportional Load Sharing and Improve Voltage Regulation in Low-Voltage DC Microgrids

DEFF Research Database (Denmark)

Anand, Sandeep; G. Fernandes, Baylon; Guerrero, Josep M.

2013-01-01

DC microgrids are gaining popularity due to high efficiency, high reliability, and easy interconnection of renewable sources as compared to the ac system. Control objectives of dc microgrid are: 1) to ensure equal load sharing (in per unit) among sources; and 2) to maintain low-voltage regulation...

Voltage scheduling for low power/energy

Science.gov (United States)

Manzak, Ali

2001-07-01

Power considerations have become an increasingly dominant factor in the design of both portable and desk-top systems. An effective way to reduce power consumption is to lower the supply voltage since voltage is quadratically related to power. This dissertation considers the problem of lowering the supply voltage at (i) the system level and at (ii) the behavioral level. At the system level, the voltage of the variable voltage processor is dynamically changed with the work load. Processors with limited sized buffers as well as those with very large buffers are considered. Given the task arrival times, deadline times, execution times, periods and switching activities, task scheduling algorithms that minimize energy or peak power are developed for the processors equipped with very large buffers. A relation between the operating voltages of the tasks for minimum energy/power is determined using the Lagrange multiplier method, and an iterative algorithm that utilizes this relation is developed. Experimental results show that the voltage assignment obtained by the proposed algorithm is very close (0.1% error) to that of the optimal energy assignment and the optimal peak power (1% error) assignment. Next, on-line and off-fine minimum energy task scheduling algorithms are developed for processors with limited sized buffers. These algorithms have polynomial time complexity and present optimal (off-line) and close-to-optimal (on-line) solutions. A procedure to calculate the minimum buffer size given information about the size of the task (maximum, minimum), execution time (best case, worst case) and deadlines is also presented. At the behavioral level, resources operating at multiple voltages are used to minimize power while maintaining the throughput. Such a scheme has the advantage of allowing modules on the critical paths to be assigned to the highest voltage levels (thus meeting the required timing constraints) while allowing modules on non-critical paths to be assigned

The design and development of low- and high-voltage ASICs for space-borne CCD cameras

Science.gov (United States)

Waltham, N.; Morrissey, Q.; Clapp, M.; Bell, S.; Jones, L.; Torbet, M.

2017-12-01

The CCD remains the pre-eminent visible and UV wavelength image sensor in space science, Earth and planetary remote sensing. However, the design of space-qualified CCD readout electronics is a significant challenge with requirements for low-volume, low-mass, low-power, high-reliability and tolerance to space radiation. Space-qualified components are frequently unavailable and up-screened commercial components seldom meet project or international space agency requirements. In this paper, we describe an alternative approach of designing and space-qualifying a series of low- and high-voltage mixed-signal application-specific integrated circuits (ASICs), the ongoing development of two low-voltage ASICs with successful flight heritage, and two new high-voltage designs. A challenging sub-system of any CCD camera is the video processing and digitisation electronics. We describe recent developments to improve performance and tolerance to radiation-induced single event latchup of a CCD video processing ASIC originally developed for NASA's Solar Terrestrial Relations Observatory and Solar Dynamics Observatory. We also describe a programme to develop two high-voltage ASICs to address the challenges presented with generating a CCD's bias voltages and drive clocks. A 0.35 μm, 50 V tolerant, CMOS process has been used to combine standard low-voltage 3.3 V transistors with high-voltage 50 V diffused MOSFET transistors that enable output buffers to drive CCD bias drains, gates and clock electrodes directly. We describe a CCD bias voltage generator ASIC that provides 24 independent and programmable 0-32 V outputs. Each channel incorporates a 10-bit digital-to-analogue converter, provides current drive of up to 20 mA into loads of 10 μF, and includes current-limiting and short-circuit protection. An on-chip telemetry system with a 12-bit analogue-to-digital converter enables the outputs and multiple off-chip camera voltages to be monitored. The ASIC can drive one or more CCDs and

A Generalised Fault Protection Structure Proposed for Uni-grounded Low-Voltage AC Microgrids

Science.gov (United States)

Bui, Duong Minh; Chen, Shi-Lin; Lien, Keng-Yu; Jiang, Jheng-Lun

2016-04-01

This paper presents three main configurations of uni-grounded low-voltage AC microgrids. Transient situations of a uni-grounded low-voltage (LV) AC microgrid (MG) are simulated through various fault tests and operation transition tests between grid-connected and islanded modes. Based on transient simulation results, available fault protection methods are proposed for main and back-up protection of a uni-grounded AC microgrid. In addition, concept of a generalised fault protection structure of uni-grounded LVAC MGs is mentioned in the paper. As a result, main contributions of the paper are: (i) definition of different uni-grounded LVAC MG configurations; (ii) analysing transient responses of a uni-grounded LVAC microgrid through line-to-line faults, line-to-ground faults, three-phase faults and a microgrid operation transition test, (iii) proposing available fault protection methods for uni-grounded microgrids, such as: non-directional or directional overcurrent protection, under/over voltage protection, differential current protection, voltage-restrained overcurrent protection, and other fault protection principles not based on phase currents and voltages (e.g. total harmonic distortion detection of currents and voltages, using sequence components of current and voltage, 3I0 or 3V0 components), and (iv) developing a generalised fault protection structure with six individual protection zones to be suitable for different uni-grounded AC MG configurations.

Realisation of low-voltage square-root-domain all-pass filters

Directory of Open Access Journals (Sweden)

Farooq A. Khanday

2013-10-01

Full Text Available Novel l ow-voltage first-order and second-order square-root-domain all-pass filters derived systematically by means of transfer function decomposition and state -space synthesis techniques are proposed. The employment of only a few geometric-mean cells and grounded capacitors permits the circuits to absorb shunt parasitic capacitances, which is desirable for production in monolithic form . The circuits enjoy the features of electronic adjustment of frequency characteristics, wider dynamic range and low-voltage environment operation. The filters are employed to design high-order all-pass filters using cascade approach. First-order low-pass and second-order band-pass filters, being the inherited building blocks of the proposed low-order all-pass filters are also discussed. The behaviour of the filters is evaluated through simulations using Taiwan semiconductor manufacturing company 0.25 μm level-3 complementary metal oxide semiconductor process parameters, where the most important performance factors are considered.

Fully low voltage and large area searching scanning tunneling microscope

International Nuclear Information System (INIS)

Pang, Zongqiang; Wang, Jihui; Lu, Qingyou

2009-01-01

We present a novel scanning tunneling microscope (STM), which allows the tip to travel a large distance (millimeters) on the sample and take images (to find microscopic targets) anywhere it reaches without losing atomic resolution. This broad range searching capability, together with the coarse approach and scan motion, is all done with only one single piezoelectric tube scanner as well as with only low voltages (<15 V). Simple structure, low interference and high precision are thus achieved. To this end, a pillar and a tube scanner are mounted in parallel on a base with one ball glued on the pillar top and two balls glued on the scanner top. These three balls form a narrow triangle, which supports a triangular slider piece. By inertial stepping, the scanner can move the slider toward the pillar (coarse approach) or rotate the slider about the pillar (travel along sample surface). Since all the stepping motions are driven by the scanner's lateral bending which is large per unit voltage, high voltages are unnecessary. The technology is also applicable to scanning force microscopes (SFM) such as atomic force microscopes (AFM), etc

Low-voltage CMOS operational amplifiers theory, design and implementation

CERN Document Server

Sakurai, Satoshi

1995-01-01

Low-Voltage CMOS Operational Amplifiers: Theory, Design and Implementation discusses both single and two-stage architectures. Opamps with constant-gm input stage are designed and their excellent performance over the rail-to-rail input common mode range is demonstrated. The first set of CMOS constant-gm input stages was introduced by a group from Technische Universiteit, Delft and Universiteit Twente, the Netherlands. These earlier versions of circuits are discussed, along with new circuits developed at the Ohio State University. The design, fabrication (MOSIS Tiny Chips), and characterization of the new circuits are now complete. Basic analog integrated circuit design concepts should be understood in order to fully appreciate the work presented. However, the topics are presented in a logical order and the circuits are explained in great detail, so that Low-Voltage CMOS Operational Amplifiers can be read and enjoyed by those without much experience in analog circuit design. It is an invaluable reference boo...

A low-voltage fully balanced CMFF transconductor with improved linearity

Science.gov (United States)

Calvo, B.; Celma, S.; Alegre, J. P.; Sanz, M. T.

2007-05-01

This paper presents a new low-voltage pseudo-differential continuous-time CMOS transconductor for wideband applications. The proposed cell is based on a feedforward cancellation of the input common-mode signal and keeps the input common mode voltage constant, while the transconductance is easily tunable through a continuous bias voltage. Linearity is preserved during the tuning process for a moderate range of transconductance values. Simulation results for a 0.35 μm CMOS design show a 1:2 G m tuning range with an almost constant bandwidth over 600 MHz. Total harmonic distortion figures are below -60 dB over the whole range at 10 MHz up to a 200 μA p-p differential output. The proposed cell consumes less than 1.2 mW from a single 2.0 V supply.

The SUPERCOMET 2 Project: Teacher Seminar and Teacher Guide

Science.gov (United States)

Engstrom, V.; Ireson, G.; Latal, H.; Mathelitsch, L.; Michelini, M.; Peeters, W.; Rath, G.

2008-05-01

The Leonardo da Vinci pilot projects SUPERCOMET (2001-2004) and SUPERCOMET 2 (2004-2007) developed and tested teacher training materials for active, minds-on learning of electromagnetism and superconductivity at the level of upper secondary school. New multimedia materials for the pupils supported the teacher materials, including a teacher seminar in 4 half-day modules detailing the scientific contents, teaching methods, using ICT in physics teaching and learning, online collaboration and further resources for exploring the selected topics. The aim of these projects were to improve the quality of physics teaching on a European level, involving a combined total of 45 partners in 16 countries, and conducting trials at 67 schools with approx. 230 teachers, 280 trainee teachers and 2200 pupils. New follow-up projects develop hands-on materials for carrying out the activities described in the teacher guide and seminars and additional teacher materials involving modelling, simulations and data logging.

Kennedy Space Center's NASA/Contractor Team-Centered Total Quality Management Seminar: Results, methods, and lessons learned

Science.gov (United States)

Kinlaw, Dennis C.; Eads, Jeannette

1992-01-01

It is apparent to everyone associated with the Nation's aeronautics and space programs that the challenge of continuous improvement can be reasonably addressed only if NASA and its contractors act together in a fully integrated and cooperative manner that transcends the traditional boundaries of proprietary interest. It is, however, one thing to assent to the need for such integration and cooperation; it is quite another thing to undertake the hard tasks of turning such a need into action. Whatever else total quality management is, it is fundamentally a team-centered and team-driven process of continuous improvement. The introduction of total quality management at KSC, therefore, has given the Center a special opportunity to translate the need for closer integration and cooperation among all its organizations into specific initiatives. One such initiative that NASA and its contractors have undertaken at KSC is a NASA/Contractor team-centered Total Quality Management Seminar. It is this seminar which is the subject of this paper. The specific purposes of this paper are to describe the following: Background, development, and evolution of Kennedy Space Center's Total Quality Management Seminar; Special characteristics of the seminar; Content of the seminar; Meaning and utility of a team-centered design for TQM training; Results of the seminar; Use that one KSC contractor, EG&G Florida, Inc. has made of the seminar in its Total Quality Management initiative; and Lessons learned.

Low pull-in voltage electrostatic MEMS switch using liquid dielectric

KAUST Repository

Zidan, Mohammed A.

2014-08-01

In this paper, we present an electrostatic MEMS switch with liquids as dielectric to reduce the actuation voltage. The concept is verified by simulating a lateral dual gate switch, where the required pull-in voltage is reduced by more than 8 times after using water as a dielectric, to become as low as 5.36V. The proposed switch is simulated using COMSOL multiphysics using various liquid volumes to study their effect on the switching performance. Finally, we propose the usage of the lateral switch as a single switch XOR logic gate.

30 CFR 77.906 - Trailing cables supplying power to low-voltage mobile equipment; ground wires and ground check...

Science.gov (United States)

2010-07-01

... portable or mobile equipment from low-voltage three-phase resistance grounded power systems shall contain... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Trailing cables supplying power to low-voltage... STANDARDS, SURFACE COAL MINES AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Low- and Medium-Voltage...

Best-effort Support for a Virtual Seminar Room

DEFF Research Database (Denmark)

Sharp, Robin; Todirica, Edward Alexandru

2002-01-01

This paper describes the RTMM Virtual Seminar Room, an interactive distributed multimedia application based on a platform with a simple middleware architecture, using best effort scheduling and a best effort network service. Emphasis has been placed on achieving low latency in all parts...

Design and experimental investigation of a low-voltage thermoelectric energy harvesting system for wireless sensor nodes

International Nuclear Information System (INIS)

Guan, Mingjie; Wang, Kunpeng; Xu, Dazheng; Liao, Wei-Hsin

2017-01-01

Highlights: • A thermoelectric energy harvesting system for wireless sensor nodes is designed. • An ultra-low voltage self-startup is implemented. • Maximum power point tracking and low power designs are applied for high efficiency. • Efficiency of 44.2–75.4% is obtained with open-circuit voltage of 84–400 mV. • System efficiency is higher than the commercial BQ25504 converter. - Abstract: A thermoelectric energy harvesting system designed to harvest tens of microwatts to several milliwatts from low-voltage thermoelectric generators is presented in this paper. The proposed system is based-on a two-stage boost scheme with self-startup ability. A maximum power point tracking technique based on the open-circuit voltage is adopted in the boost converter for high efficiency. Experimental results indicate that the proposed system can harvest thermoelectric energy and run a microcontroller unit and a wireless sensor node under low input voltage and power with high efficiency. The harvest system and wireless sensor node can be self-powered with minimum thermoelectric open-circuit voltage as 62 mV and input power of 84 μW. With a self-startup scheme, the proposed system can self-start with a 20 mV input voltage. Low power designs are applied in the system to reduce the quiescent dissipation power. It results in better performance considering the conversion efficiency and self-startup ability compared to commercial boost systems used for thermal energy harvesting.

Applied Mathematics Seminar 1982

International Nuclear Information System (INIS)

1983-01-01

This report contains the abstracts of the lectures delivered at 1982 Applied Mathematics Seminar of the DPD/LCC/CNPq and Colloquy on Applied Mathematics of LCC/CNPq. The Seminar comprised 36 conferences. Among these, 30 were presented by researchers associated to brazilian institutions, 9 of them to the LCC/CNPq, and the other 6 were given by visiting lecturers according to the following distribution: 4 from the USA, 1 from England and 1 from Venezuela. The 1981 Applied Mathematics Seminar was organized by Leon R. Sinay and Nelson do Valle Silva. The Colloquy on Applied Mathematics was held from october 1982 on, being organized by Ricardo S. Kubrusly and Leon R. Sinay. (Author) [pt

ANALYSIS OF GRID-CONNECTED PHOTOVOLTAIC SYSTEM INTEGRATON ON LOW-VOLTAGE DISTRIBUTION NETWORK

Directory of Open Access Journals (Sweden)

NEMES C.

2016-03-01

Full Text Available The introduction of new local sources on the distribution network will impact the quality of power in different ways. The low-voltage customers are strongly affected by the level of power quality, especially by harmonic distortions. In present paper, the impact on the power quality of a low-voltage utility network with an integrated PV system has been assessed at the point of common coupling of the PV system. In this order, the most representative power quality indices concerning the harmonic distortion have been monitored and compared with the limits set by the corresponding standards.

Methods and Strategies for Overvoltage Prevention in Low Voltage Distribution Systems with PV

DEFF Research Database (Denmark)

Hashemi Toghroljerdi, Seyedmostafa; Østergaard, Jacob

2016-01-01

to handle a high share of PV power. This paper provides an in-depth review of methods and strategies proposed to prevent overvoltage in LV grids with PV, and discusses the effectiveness, advantages, and disadvantages of them in detail. Based on the mathematical framework presented in the paper......, the overvoltage caused by high PV penetration is described, solutions to facilitate higher PV penetration are classified, and their effectiveness, advantages, and disadvantages are illustrated. The investigated solutions include the grid reinforcement, electrical energy storage application, reactive power...... absorption by PV inverters, application of active medium voltage to low voltage (MV/LV) transformers, active power curtailment, and demand response (DR). Coordination between voltage control units by localized, distributed, and centralized voltage control methods is compared using the voltage sensitivity...

CS Seminar Videos

OpenAIRE

Ong, Derek; Tona, Glen; Gibb, Kyle; Parbadia, Sivani

2013-01-01

Main site for our project can be found at this URL: http://vtechworks.lib.vt.edu/handle/10919/19036. From here you can find videos of all the CS seminars and distinguished lectures given this semester. Each video has its own abstract and description. The files attached in this section are a final report in both raw Word Document and archival PDF formats and a presentation in both raw Powerpoint and archival PDF formats. Computer Science seminars are a very educational and interesting as...

Clean coal technologies---An international seminar: Seminar evaluation and identification of potential CCT markets

International Nuclear Information System (INIS)

Guziel, K.A.; Poch, L.A.; Gillette, J.L.; Buehring, W.A.

1991-07-01

The need for environmentally responsible electricity generation is a worldwide concern. Because coal is available throughout the world at a reasonable cost, current research is focusing on technologies that use coal with minimal environmental effects. The United States government is supporting research on clean coal technologies (CCTs) to be used for new capacity additions and for retrofits to existing capacity. To promote the worldwide adoption of US CCTs, the US Department of Energy, the US Agency for International Development, and the US Trade and Development Program sponsored a two-week seminar titled Clean Coal Technologies -- An International Seminar. Nineteen participants from seven countries were invited to this seminar, which was held at Argonne National Laboratory in June 1991. During the seminar, 11 US CCT vendors made presentations on their state-of-the-art and commercially available technologies. The presentations included technical, environmental, operational, and economic characteristics of CCTs. Information on financing and evaluating CCTs also was presented, and participants visited two CCT operating sites. The closing evaluation indicated that the seminar was a worthwhile experience for all participants and that it should be repeated. The participants said CCT could play a role in their existing and future electric capacity, but they agreed that more CCT demonstration projects were needed to confirm the reliability and performance of the technologies

TECHNICAL TRAINING SEMINAR

CERN Multimedia

Davide Vitè

2002-01-01

NEW DATE AND TIME!!! Wednesday 26 June from 11:00 to 12:00 - Training Centre Auditorium - bldg. 593-11 High Temperature Superconductors: Progress and Issues Prof. Jan Evetts / UNIVERSITY OF CAMBRIDGE, Department of Materials Science and Metallurgy, UK Grappling with grain boundaries: Current transport processes in granular High Temperature Superconductors (HTS) The development of High Temperature Superconductors, seen from a materials scientist's point of view, is relevant to the superconductivity community at CERN: their possible high current applications can include high performance magnets for future accelerators. There is an urgent need to develop a quantitative description of HTS conductors in terms of their complex anisotropy, inhomogeneity and dimensionality. This is essential both for the practical specification of a conductor and for charting routes to conductor optimisation. The critical current, the n-value, dissipation and quenching characteristics are amongst most important parameters that make u...

Multi-objective optimization control of plug-in electric vehicles in low voltage distribution networks

DEFF Research Database (Denmark)

García-Villalobos, J.; Zamora, I.; Knezovic, Katarina

2016-01-01

The massive introduction of plug-in electric vehicles (PEVs) into low voltage (LV) distribution networks will lead to several problems, such as: increase of energy losses, decrease of distribution transformer lifetime, lines and transformer overload issues, voltage drops and unbalances...

Piezoelectric transformers for low-voltage generation of gas discharges and ionic winds in atmospheric air

Energy Technology Data Exchange (ETDEWEB)

Johnson, Michael J. [Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, Indianapolis 46556 (United States); Go, David B., E-mail: dgo@nd.edu [Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, Indianapolis 46556 (United States); Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indianapolis 46556 (United States)

2015-12-28

To generate a gas discharge (plasma) in atmospheric air requires an electric field that exceeds the breakdown threshold of ∼30 kV/cm. Because of safety, size, or cost constraints, the large applied voltages required to generate such fields are often prohibitive for portable applications. In this work, piezoelectric transformers are used to amplify a low input applied voltage (<30 V) to generate breakdown in air without the need for conventional high-voltage electrical equipment. Piezoelectric transformers (PTs) use their inherent electromechanical resonance to produce a voltage amplification, such that the surface of the piezoelectric exhibits a large surface voltage that can generate corona-like discharges on its corners or on adjacent electrodes. In the proper configuration, these discharges can be used to generate a bulk air flow called an ionic wind. In this work, PT-driven discharges are characterized by measuring the discharge current and the velocity of the induced ionic wind with ionic winds generated using input voltages as low as 7 V. The characteristics of the discharge change as the input voltage increases; this modifies the resonance of the system and subsequent required operating parameters.

Search as Learning (Dagstuhl Seminar 17092)

OpenAIRE

Collins-Thompson, Kevyn; Hansen, Preben; Hauff, Claudia

2017-01-01

This report describes the program and the results of Dagstuhl Seminar 17092 "Search as Learning", which brought together 26 researchers from diverse research backgrounds. The motivation for the seminar stems from the fact that modern Web search engines are largely engineered and optimized to fulfill lookup tasks instead of complex search tasks. The latter though are an essential component of information discovery and learning. The 3-day seminar started with four perspective talks, providing f...

The Simulation Study of a Restructured Residential Low-Voltage Distribution System Microgrid

Directory of Open Access Journals (Sweden)

L. Ramesh

2016-12-01

Full Text Available A primary and necessary focus in creating a greener environment is the conversion of existing power-generation sources to renewable power sources in the near future. Another important focus is to develop sustainable household power generation to a low-voltage electricity grid with a power purchase and selling facility. To help with achieving the above vision, the objective of this work is to critically analyze the existing low-voltage distribution system and make suggestions for restructuring it to the low-voltage interconnected microgrid (MG. The test was carried out in the Tamil Nadu Electricity Board (TNEB 100kVA transformer feeder which was connected to supply around 100 houses with electricity. The performance analysis of the proposed system was examined through different case studies, represented as a normal operating condition of the existing distribution system and a reconstructed and interconnected MG to the TNEB grid. The project was designed and analyzed using PSCAD software. The results discussed in the project are helpful in examining the effects of multiple distributed energy resources on distributed generation. In future, knowledge of these effects may be helpful for rural area electrification.

Technical Training Seminar

CERN Multimedia

2003-01-01

Tuesday 2 December From 10:00 to 16:00 - Training Centre Auditorium - bldg. 593, room 11 CST Customer Workshop - CST Computer Simulation Technology GmbH A Computer Simulation Technology (CST, http://www.cst.com) Customer Workshop is organised at CERN for people who are interested in 3D electromagnetic field simulation with CST Microwave Studio® and CST Design Studio. The CST Microwave Studio is a specialist tool for the fast and accurate 3D electromagnetic simulation of high frequency problems, with a broad application range, shorter development cycles, and virtual prototyping before physical trials. CST Design Studio provides a design environment where results from diverse simulators can be combined and analysed; a new version will be released in 2004. • 10:00 - 12:00 CST Microwave Studio, version 5. CAD-import and modelling. The new multilevel subgridding technique. Advanced new features of the T-, F- and E-solver. The user defined post-processing templates (first part). • 12:0...

Technical Training Seminar

CERN Multimedia

2003-01-01

Tuesday 2 December From 10:00 to 16:00 - Training Centre Auditorium - bldg. 593, room 11 CST Customer Workshop - CST Computer Simulation Technology GmbH A Computer Simulation Technology (CST, http://www.cst.com) Customer Workshop is organised at CERN for people who are interested in 3D electromagnetic field simulation with CST Microwave Studio® and CST Design Studio. The CST Microwave Studio is a specialist tool for the fast and accurate 3D electromagnetic simulation of high frequency problems, with a broad application range, shorter development cycles, and virtual prototyping before physical trials. CST Design Studio provides a design environment where results from diverse simulators can be combined and analysed; a new version will be released in 2004. 10:00 - 12:00 CST Microwave Studio, version 5. CAD-import and modelling. The new multilevel subgridding technique. Advanced new features of the T-, F- and E-solver. The user defined post-processing templates (first part). 12:00 - 13:00 Lunch. 13:00 - 1...

Parenting Seminars for Divorcing Parents.

Science.gov (United States)

Frieman, Barry B.

1995-01-01

Profiles the parenting seminars and counseling services for divorcing parents offered by the Children of Separation and Divorce Center, a community service agency in Maryland. The seminars are designed to help parents adjust to divorce and understand the needs of their children during and after the divorce process. (MDM)

A Decentralized Multi-Agent-Based Approach for Low Voltage Microgrid Restoration

Directory of Open Access Journals (Sweden)

Ebrahim Rokrok

2017-09-01

Full Text Available Although a well-organized power system is less subject to blackouts, the existence of a proper restoration plan is nevertheless still essential. The goal of a restoration plan is to bring the power system back to its normal operating conditions in the shortest time after a blackout occurs and to minimize the impact of the blackout on society. This paper presents a decentralized multi-agent system (MAS-based restoration method for a low voltage (LV microgrid (MG. In the proposed method, the MG local controllers are assigned to the specific agents who interact with each other to achieve a common decision in the restoration procedure. The evaluation of the proposed decentralized technique using a benchmark low-voltage MG network demonstrates the effectiveness of the proposed restoration plan.

Seminar proceedings. Seminar on piping reliability

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-10-01

The international seminar brought together the disciplines of probabilistic safety assessment and probabilistic fracture mechanics. The work performed by the joint Nordic Nuclear Safety Research Project NKS/RAK 1.2 and the SLAP project was presented the first day. The second was mainly devoted to the integration of the two disciplines. 11 contributions have been separately indexed.

Seminar proceedings. Seminar on piping reliability

International Nuclear Information System (INIS)

1997-10-01

The international seminar brought together the disciplines of probabilistic safety assessment and probabilistic fracture mechanics. The work performed by the joint Nordic Nuclear Safety Research Project NKS/RAK 1.2 and the SLAP project was presented the first day. The second was mainly devoted to the integration of the two disciplines. 11 contributions have been separately indexed

Recycling potential for low voltage and high voltage high rupturing capacity fuse links.

Science.gov (United States)

Psomopoulos, Constantinos S; Barkas, Dimitrios A; Kaminaris, Stavros D; Ioannidis, George C; Karagiannopoulos, Panagiotis

2017-12-01

Low voltage and high voltage high-rupturing-capacity fuse links are used in LV and HV installations respectively, protecting mainly the LV and HV electricity distribution and transportation networks. The Waste Electrical and Electronic Equipment Directive (2002/96/EC) for "Waste of electrical and electronic equipment" is the main related legislation and as it concerns electrical and electronic equipment, it includes electric fuses. Although, the fuse links consist of recyclable materials, only small scale actions have been implemented for their recycling around Europe. This work presents the possibilities for material recovery from this specialized industrial waste for which there are only limited volume data. Furthermore, in order to present the huge possibilities and environmental benefits, it presents the potential for recycling of HRC fuses used by the Public Power Corporation of Greece, which is the major consumer for the country, but one of the smallest ones in Europe and globally, emphasizing in this way in the issue. According to the obtained results, fuse recycling could contribute to the effort for minimize the impacts on the environment through materials recovery and reduction of the wastes' volume disposed of in landfills. Copyright © 2017 Elsevier Ltd. All rights reserved.

Harmonic Analysis and Mitigation of Low- Frequency Switching Voltage Source Inverter with Auxiliary VSI

DEFF Research Database (Denmark)

Bai, Haofeng; Wang, Xiongfei; Blaabjerg, Frede

2018-01-01

The output currents of high-power Voltage Source Inverters (VSIs) are distorted by the switching harmonics and the background harmonics in the grid voltage. This paper presents an active harmonic filtering scheme for high-power, low-frequency switching VSIs with an additional auxiliary VSI. In th...

Robust and Energy-Efficient Ultra-Low-Voltage Circuit Design under Timing Constraints in 65/45 nm CMOS

Directory of Open Access Journals (Sweden)

David Bol

2011-01-01

Full Text Available Ultra-low-voltage operation improves energy efficiency of logic circuits by a factor of 10×, at the expense of speed, which is acceptable for applications with low-to-medium performance requirements such as RFID, biomedical devices and wireless sensors. However, in 65/45 nm CMOS, variability and short-channel effects significantly harm robustness and timing closure of ultra-low-voltage circuits by reducing noise margins and jeopardizing gate delays. The consequent guardband on the supply voltage to meet a reasonable manufacturing yield potentially ruins energy efficiency. Moreover, high leakage currents in these technologies degrade energy efficiency in case of long stand-by periods. In this paper, we review recently published techniques to design robust and energy-efficient ultra-low-voltage circuits in 65/45 nm CMOS under relaxed yet strict timing constraints.

Increasing Effectiveness of Strategic Planning Seminars through Learning Style

Science.gov (United States)

Yildirim, Nail

2010-01-01

This research tests the effectiveness of taking learning style variables from the Kolb learning model in designing strategic planning seminars. We observe in our research that the participants in the seminar--school principals--positively judge the effectiveness of the seminar. The research also tests the seminar's effectiveness in terms of the…

A SCHEDULING SCHEME WITH DYNAMIC FREQUENCY CLOCKING AND MULTIPLE VOLTAGES FOR LOW POWER DESIGNS

Institute of Scientific and Technical Information of China (English)

Wen Dongxin; Wang Ling; Yang Xiaozong

2007-01-01

In this letter, a scheduling scheme based on Dynamic Frequency Clocking (DFC) and multiple voltages is proposed for low power designs under the timing and the resource constraints.Unlike the conventional methods at high level synthesis where only voltages of nodes were considered,the scheme based on a gain function considers both voltage and frequency simultaneously to reduce energy consumption. Experiments with a number of DSP benchmarks show that the proposed scheme achieves an effective energy reduction.

Introduction of cooperating conductive components into the phosphor to improve the low voltage cathodoluminescence

International Nuclear Information System (INIS)

Shang, Chun Yu; Kang, Hui; Jiang, Hong Bo; Bu, Shu Po; Shang, Xiao Hong; Wu, Yan

2013-01-01

In order to improve the electric conductivity of Y 2 O 3 :Eu 3+ phosphor with the least amount of conductive component so as to maximize the improvement in low voltage cathodoluminescence, In 2 O 3 and Cu nanowires (NWs) were simultaneously introduced to form Cu NWs/In 2 O 3 -attached Y 2 O 3 :Eu 3+ phosphor. In 2 O 3 and Cu NWs play different roles in the formation of electrically conductive network, i.e., Cu NWs are suitable as conductive channels for charge transmission due to their one-dimensional morphology with large slenderness ratios, while the island-like In 2 O 3 condensates form local conductive contacts joining the adjacent Cu NWs. Meanwhile, In 2 O 3 forms attachment between Cu NWs and the phosphor. Owing to the cooperating effects between Cu NWs/In 2 O 3 conductive components in the phosphor, the efficiency in low voltage cathodoluminescence was significantly improved. -- Highlights: ► In 2 O 3 /Cu NWs were introduced in Y 2 O 3 :Eu 3+ phosphor to improve the low voltage cathodoluminescence. ► In 2 O 3 /Cu NWs play different key roles in the formation of electrically conductive network. ► The cooperating effect was proved by comparing the experimental data and the calculated results. ► The low voltage cathodoluminescence was significantly improved

Design and Implementation of a High Efficiency, Low Component Voltage Stress, Single-Switch High Step-Up Voltage Converter for Vehicular Green Energy Systems

Directory of Open Access Journals (Sweden)

Yu-En Wu

2016-09-01

Full Text Available In this study, a novel, non-isolated, cascade-type, single-switch, high step-up DC/DC converter was developed for green energy systems. An integrated coupled inductor and voltage lift circuit were applied to simplify the converter structure and satisfy the requirements of high efficiency and high voltage gain ratios. In addition, the proposed structure is controllable with a single switch, which effectively reduces the circuit cost and simplifies the control circuit. With the leakage inductor energy recovery function and active voltage clamp characteristics being present, the circuit yields optimizable conversion efficiency and low component voltage stress. After the operating principles of the proposed structure and characteristics of a steady-state circuit were analyzed, a converter prototype with 450 W, 40 V of input voltage, 400 V of output voltage, and 95% operating efficiency was fabricated. The Renesas MCU RX62T was employed to control the circuits. Experimental results were analyzed to validate the feasibility and effectiveness of the proposed system.

Substrate effects in high gain, low operating voltage SnSe2 photoconductor

Science.gov (United States)

Krishna, Murali; Kallatt, Sangeeth; Majumdar, Kausik

2018-01-01

High gain photoconductive devices find wide spread applications in low intensity light detection. Ultra-thin layered materials have recently drawn a lot of attention from researchers in this regard. However, in general, a large operating voltage is required to obtain large responsivity in these devices. In addition, the characteristics are often confounded by substrate induced trap effects. Here we report multi-layer SnSe2 based photoconductive devices using two different structures: (1) SiO2 substrate supported inter-digitated electrode (IDE), and (2) suspended channel. The IDE device exhibits a responsivity of ≈ {10}3 A W-1 and ≈ 8.66× {10}4 A W-1 at operating voltages of 1 mV and 100 mV, respectively—a superior low voltage performance over existing literature on planar 2D structures. However, the responsivity reduces by more than two orders of magnitude, while the transient response improves for the suspended device—providing insights into the critical role played by the channel-substrate interface in the gain mechanism. The results, on one hand, are promising for highly sensitive photoconductive applications consuming ultra-low power, and on the other hand, show a generic methodology that could be applied to other layered material based photoconductive devices as well for extracting the intrinsic behavior.

A New Approach to High Efficincy in Isolated Boost Converters for High-Power Low-Voltage Fuel Cell Apllications

DEFF Research Database (Denmark)

Nymand, Morten; Andersen, Michael A. E.

2008-01-01

A new low-leakage-inductance low-resistance design approach to low-voltage high-power isolated boost converters is presented. Very low levels of parasitic circuit inductances are achieved by optimizing transformer design and circuit lay-out. Primary side voltage clamp circuits can be eliminated...... by the use of power MOSFETs fully rated for repetitive avalanche. Voltage rating of primary switches can now be reduced, significantly reducing switch on-state losses. Finally, silicon carbide rectifying diodes allow fast diode turn-off, further reducing losses. Test results from a 1.5 kW full-bridge boost...... converter verify theoretical analysis and demonstrate very high efficiency. Worst case efficiency, at minimum input voltage maximum power, is 96.8 percent and maximum efficiency reaches 98 percent....

Experimental Seminar on Nuclear Energy for Teachers

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-02-01

`Experimental Seminar on Nuclear Energy for Teachers` was conducted and sponsored by the Science and Technology Agency. And in order to understand nuclear energy properly through lectures and experiments with good results inclass, the seminar carried out for teachers of high schools and junior high schools by the Nuclear Technology and Education Center (NuTEC), Japan Atomic Energy Research Institute in 1990 FY to 1997 FY. In this report, details of the seminars in the above period are described and No.1 to 17 of Communication Letters of Experimental Seminar on Nuclear Energy` started at 1992 FY are described also. These letters were prepared for attendant follow-up program. And programs of recent seminars, future`s seminars, impressions and comments from attendants, reports from actual classes and others are described in these letters and they are very useful for educational classes on nuclear energy by other teachers. Therefore contents of the letters are listed and easy to refer. A part of this educational task was transferred to the Radiation Application Development Association in 1997 FY and other parts were transferred in 1998 FY. (author)

A High Resolution Switched Capacitor 1bit Sigma-Delta Modulator for Low-Voltage/Low-Power Applications

DEFF Research Database (Denmark)

Furst, Claus Efdmann

1996-01-01

A high resolution 1bit Sigma-Delta modulator for low power/low voltage applications is presented. The modulator operates at a supply of 1-1.5V, the current drain is 0.1mA. The maximum resolution is 87dB equivalent to 14 bits of resolution. This is achieved with a signal-band of 5kHz, over-samplin...

High Voltage Distribution System (HVDS) as a better system compared to Low Voltage Distribution System (LVDS) applied at Medan city power network

Science.gov (United States)

Dinzi, R.; Hamonangan, TS; Fahmi, F.

2018-02-01

In the current distribution system, a large-capacity distribution transformer supplies loads to remote locations. The use of 220/380 V network is nowadays less common compared to 20 kV network. This results in losses due to the non-optimal distribution transformer, which neglected the load location, poor consumer profile, and large power losses along the carrier. This paper discusses how high voltage distribution systems (HVDS) can be a better system used in distribution networks than the currently used distribution system (Low Voltage Distribution System, LVDS). The proposed change of the system into the new configuration is done by replacing a large-capacity distribution transformer with some smaller-capacity distribution transformers and installed them in positions that closest to the load. The use of high voltage distribution systems will result in better voltage profiles and fewer power losses. From the non-technical side, the annual savings and payback periods on high voltage distribution systems will also be the advantage.

Programmable Low-Power Low-Noise Capacitance to Voltage Converter for MEMS Accelerometers.

Science.gov (United States)

Royo, Guillermo; Sánchez-Azqueta, Carlos; Gimeno, Cecilia; Aldea, Concepción; Celma, Santiago

2016-12-30

In this work, we present a capacitance-to-voltage converter (CVC) for capacitive accelerometers based on microelectromechanical systems (MEMS). Based on a fully-differential transimpedance amplifier (TIA), it features a 34-dB transimpedance gain control and over one decade programmable bandwidth, from 75 kHz to 1.2 MHz. The TIA is aimed for low-cost low-power capacitive sensor applications. It has been designed in a standard 0.18-μm CMOS technology and its power consumption is only 54 μW. At the maximum transimpedance configuration, the TIA shows an equivalent input noise of 42 fA/ Hz at 50 kHz, which corresponds to 100 μg/ Hz .

Programmable Low-Power Low-Noise Capacitance to Voltage Converter for MEMS Accelerometers

Directory of Open Access Journals (Sweden)

Guillermo Royo

2016-12-01

Full Text Available In this work, we present a capacitance-to-voltage converter (CVC for capacitive accelerometers based on microelectromechanical systems (MEMS. Based on a fully-differential transimpedance amplifier (TIA, it features a 34-dB transimpedance gain control and over one decade programmable bandwidth, from 75 kHz to 1.2 MHz. The TIA is aimed for low-cost low-power capacitive sensor applications. It has been designed in a standard 0.18-μm CMOS technology and its power consumption is only 54 μW. At the maximum transimpedance configuration, the TIA shows an equivalent input noise of 42 fA/ Hz at 50 kHz, which corresponds to 100 μg/ Hz .

Low operating voltage n-channel organic field effect transistors using lithium fluoride/PMMA bilayer gate dielectric

Energy Technology Data Exchange (ETDEWEB)

Kumar, S.; Dhar, A., E-mail: adhar@phy.iitkgp.ernet.in

2015-10-15

Highlights: • Alternative to chemically crosslinking of PMMA to achieve low leakage in provided. • Effect of LiF in reducing gate leakage through the OFET device is studied. • Effect of gate leakage on transistor performance has been investigated. • Low voltage operable and low temperature processed n-channel OFETs were fabricated. - Abstract: We report low temperature processed, low voltage operable n-channel organic field effect transistors (OFETs) using N,N′-Dioctyl-3,4,9,10-perylenedicarboximide (PTCDI-C{sub 8}) organic semiconductor and poly(methylmethacrylate) (PMMA)/lithium fluoride (LiF) bilayer gate dielectric. We have studied the role of LiF buffer dielectric in effectively reducing the gate leakage through the device and thus obtaining superior performance in contrast to the single layer PMMA dielectric devices. The bilayer OFET devices had a low threshold voltage (V{sub t}) of the order of 5.3 V. The typical values of saturation electron mobility (μ{sub s}), on/off ratio and inverse sub-threshold slope (S) for the range of devices made were estimated to be 2.8 × 10{sup −3} cm{sup 2}/V s, 385, and 3.8 V/decade respectively. Our work thus provides a potential substitution for much complicated process of chemically crosslinking PMMA to achieve low leakage, high capacitance, and thus low operating voltage OFETs.

Freshman Seminars: Interdisciplinary Engagements in Astronomy

Science.gov (United States)

Hemenway, M. K.

2006-08-01

The Freshman Seminar program at the University of Texas is designed to allow groups of fifteen students an engaging introduction to the University. The seminars introduce students to the resources of the university and allow them to identify interesting subjects for further research or future careers. An emphasis on oral and written communication by the students provides these first-year students a transition to college-level writing and thinking. Seminar activities include field trips to an art museum, a research library, and the Humanities Research Center rare book collection. This paper will report on two seminars, each fifteen weeks in length. In "The Galileo Scandal" students examine Galileo's struggle with the church (including a mock trial). They perform activities that connect his use of the telescope and observations to astronomical concepts. In "Astronomy and the Humanities" students analyze various forms of human expression that have astronomical connections (art, drama, literature, music, poetry, and science fiction); they perform hands-on activities to reinforce the related astronomy concepts. Evaluation of the seminars indicates student engagement and improvement in communication skills. Many of the activities could be used independently to engage students enrolled in standard introductory astronomy classes.

A low voltage programmable unipolar inverter with a gold nanoparticle monolayer on plastic.

Science.gov (United States)

Zhou, Ye; Han, Su-Ting; Huang, Long-Biao; Huang, Jing; Yan, Yan; Zhou, Li; Roy, V A L

2013-05-24

A programmable low voltage unipolar inverter with saturated-load configuration has been demonstrated on a plastic substrate. A self-assembled monolayer of gold (Au) nanoparticles was inserted into the dielectric layer acting as a charge trapping layer. The inverter operated well with supply voltages of inverter. Furthermore, the programmable behavior was maintained well at various bending states, demonstrating the adequate flexibility of our devices.

Management & Communication - Programme of Seminars September to December 2003

CERN Document Server

Nathalie Dumeaux

2003-01-01

Situation : 23.09.2003 Dates Days Available Séminaires bilingues/Bilingual seminars Managing a CERN unit - to be a Manager/ Gérer une unité au CERN - Etre Manager (Module 1) 7, 8, 9, 10 octobre 3 non Communication interpersonnelle/ Interpersonal Communication (Module 1-CM) 21, 22, 23 octobre 3 non Managing a CERN unit - to be a Manager/ Gérer une unité au CERN - Etre Manager (Module 2) 28, 29 octobre 2 non Gestion de la qualité/Quality Management 10, 11, 12 novembre 3 oui Managing a CERN unit - to be a Manager/ Gérer une unité au CERN - Etre Manager (Module 3) 11, 12 novembre 2 non Gestion des risques /Risk Management 11, 12 décembre 2 oui Seminars In English Communicating Effectively (first part) 12, 13 November 4 yes Communicating Effectively (second part) 11, 12 December Communicating effectively in your team 19, 20 November 2 no Performance Appraisal Training MAPS 26, 27, 28 November 3 yes Managing by Project 3, 4 December 3 n...

Baking of tandem accelerator tube by low voltage arc discharge

International Nuclear Information System (INIS)

Nakajima, Yutaka

1982-01-01

In designing the accelerating tube for a static tandem accelerator in Kyushu University, the basic policy was as described below: individual unit composing the accelerating tube should fully withstand the electric field of 2 MV/m, and electric discharge must not be propagated from one unit to the adjacent unit when these are assembled to the accelerating tube. The accelerating tube units are each 25 cm in length, and both high and low energy sides are composed of 20 units, respectively. Although about 10 -9 Torr vacuum was obtained at the both ends of the accelerating tube by baking the tube at 300 to 350 deg C with electric heaters wound outside the tube in the conventional method, vast outgas was generated, which decreased vacuum by two or three figures if breakdown occurred through the intermediary of outgas. As a method of positively outgassing and cleaning the electrodes inside the accelerating tube, it was attempted to directly bake all the electrodes in the accelerating tube by causing strong arc discharge flowing H 2 gas in the tube. As a result of considering the conditions for this method, the low voltage arc discharge was employed using oxide cathodes. Thus, after implementing 10A arc discharge for several hours, the voltage was able to be raised to 10 MV almost immediately after the vacuum recovery, and further, after another conditioning for several hours, it was successful to raise voltage up to 11 MV. (Wakatsuki, Y.)

[Leadership seminars: what are they good for?].

Science.gov (United States)

Schubert, P

2010-08-01

Professional training courses are a matter of course for any surgeon who wants to offer the best and most up-to-date treatment to patients. But after leaving the operating room surgeons will be confronted with issues that demand more than surgical skills. As a leader of a team the expectations and needs of the people under his care and of the managers above him need to be faced. Leadership seminars are an opportunity to become aware of these and to learn how to competently react to them. They can offer support on many levels: what type of leader am I? How do I appear to others? What do my employees/superiors expect from me? How can I manage my staff, not least in terms of reaching the goals of my department or the company? Which leadership tools are there and how can I use them? Good leadership seminars can be recognized by the balance of different aspects which they cover: they offer new expertise as well as opportunities for reflecting on one's personality and everyday work and introduce new approaches with an immediate opportunity for practicing them effectively. The key is that managers monitor their progress continuously and ideally continue to develop themselves further throughout their working life.

Low-voltage, large-strain soft electrothermal actuators based on laser-reduced graphene oxide/Ag particle composites

Science.gov (United States)

Wang, Qian; Li, Yu-Tao; Zhang, Tian-Yu; Wang, Dan-Yang; Tian, Ye; Yan, Jun-Chao; Tian, He; Yang, Yi; Yang, Fan; Ren, Tian-Ling

2018-03-01

In this paper, low-voltage, large-strain flexible electrothermal actuators (ETAs) based on laser-reduced graphene oxide (LRGO)/Ag particle composites were fabricated in a simple and cost-efficient process. By adding Ag particles to the LRGO, the sheet resistance decreased effectively. Under a driving voltage of 28 V, the actuator obtained a bending angle of 192° within 6 s. Besides, the bending deformation could be precisely controlled by the driving voltage ranging from 10° to 192°. Finally, a gripper composed of two actuators was demonstrated to manipulate a piece of polydimethylsiloxane block. With the advantages of low-voltage, fast-response, and easy-to-manufacture, the graphene based ETAs have a promising application in soft robotics and soft machines.

Design Margin Elimination Through Robust Timing Error Detection at Ultra-Low Voltage

OpenAIRE

Reyserhove, Hans; Dehaene, Wim

2017-01-01

This paper discusses a timing error masking-aware ARM Cortex M0 microcontroller system. Through in-path timing error detection, operation at the point-of-first-failure is possi- ble without corrupting the pipeline state, effectively eliminat- ing traditional timing margins. Error events are flagged and gathered to allow dynamic voltage scaling. The error-aware microcontroller was implemented in a 40nm CMOS process and realizes ultra-low voltage operation down to 0.29V at 5MHz consuming 12.90p...

Loss of Synchronism of Wind Turbine Converters during Low Voltage Grid Faults

DEFF Research Database (Denmark)

Göksu, Ömer; Sørensen, Poul Ejnar; Iov, Florin

2014-01-01

In the recent grid codes, wind power plants are required to stay connected and inject reactive and active currents during grid short-circuit faults, even when the grid voltage drops down to zero. However, the physical fact, Loss of Synchronism (LOS) of wind turbines during these very low voltage ...... as whole. Additionally, existing methods to solve the LOS problem are briefly reviewed, and a closed loop frequency based solution is implemented within PowerFactory simulations of a detailed generic wind power plant model....

Low-profile high-voltage compact gas switch

International Nuclear Information System (INIS)

Goerz, D.A.; Wilson, M.J.; Speer, R.D.

1997-01-01

This paper discusses the development and testing of a low-profile, high-voltage, spark-gap switch designed to be closely coupled with other components into an integrated high-energy pulsed-power source. The switch is designed to operate at 100 kV using SF6 gas pressurized to less than 0.7 MPa. The volume of the switch cavity region is less than 1.5 cm3, and the field stress along the gas-dielectric interface is as high as 130 kV/cm. The dielectric switch body has a low profile that is only I -cm tall at its greatest extent and nominally 2-mm thick over most of its area. This design achieves a very low inductance of less than 5 nH, but results in field stresses exceeding 500 kV/cm in the dielectric material. Field modeling was done to determine the appropriate shape for the highly stressed insulator and electrodes, and special manufacturing techniques were employed to mitigate the usual mechanisms that induce breakdown and failure in solid dielectrics. Static breakdown tests verified that the switch operates satisfactorily at 100 kV levels. The unit has been characterized with different shaped electrodes having nominal gap spacings of 2.0, 2.5, and 3.0 mm. The relationship between self-break voltage and operating pressure agrees well with published data on gas properties, accounting for the field enhancements of the electrode shapes being used. Capacitor discharge tests in a low inductance test fixture exhibited peak currents up to 25 kA with characteristic frequencies of the ringdown circuit ranging from 10 to 20 MHz. The ringdown waveforms and scaling of measured parameters agree well with circuit modeling of the switch and test fixture. Repetitive operation has been demonstrated at moderate rep-rates up to 15 Hz, limited by the power supply being used. Preliminary tests to evaluate lifetime of the compact switch assembly have been encouraging. In one case, after more than 7,000 high-current ringdown tests with approximately 30 C of total charge transferred, the

Proton conducting sodium alginate electrolyte laterally coupled low-voltage oxide-based transistors

Energy Technology Data Exchange (ETDEWEB)

Liu, Yang Hui; Wan, Qing, E-mail: wanqing@nju.edu.cn [Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); School of Electronic Science and Engineering, Nanjing University, Nanjing 210093 (China); Qiang Zhu, Li, E-mail: lqzhu@nimte.ac.cn [Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Shi, Yi [School of Electronic Science and Engineering, Nanjing University, Nanjing 210093 (China)

2014-03-31

Solution-processed sodium alginate electrolyte film shows a high proton conductivity of ∼5.5 × 10{sup −3} S/cm and a high lateral electric-double-layer (EDL) capacitance of ∼2.0 μF/cm{sup 2} at room temperature with a relative humidity of 57%. Low-voltage in-plane-gate indium-zinc-oxide-based EDL transistors laterally gated by sodium alginate electrolytes are fabricated on glass substrates. The field-effect mobility, current ON/OFF ratio, and subthreshold swing of such EDL transistors are estimated to be 4.2 cm{sup 2} V{sup −1} s{sup −1}, 2.8 × 10{sup 6}, and 130 mV/decade, respectively. At last, a low-voltage driven resistor-load inverter is also demonstrated. Such in-plane-gate EDL transistors have potential applications in portable electronics and low-cost biosensors.

Toward the optimization of PC-based training

Science.gov (United States)

Cho, Kohei; Murai, Shunji

Since 1992, the National Space Development Agency of Japan (NASDA) and the Economic and Social Commission for Asia and the Pacific (ESCAP) have been co-organising the Regional Remote Sensing Seminar on Tropical Ecosystem Management (Program Chairman: Prof. Shunji Murai) every year in some country in Asia. In these seminars, the members of the ISPRS Working Group VI/2 'Computer Assisted Teaching' have been performing a PC-based hands-on-training on remote sensing and GIS for beginners. The main objective of the training was to transfer not only knowledge but also the technology of remote sensing and GIS to the beginners. The software and CD-ROM data set provided at the training were well designed not only for training but also for practical data analysis. This paper presents an outline of the training and discusses the optimisation of PC-based training for remote sensing and GIS.

Low voltage electron beam accelerators

International Nuclear Information System (INIS)

Ochi, Masafumi

2003-01-01

Widely used electron accelerators in industries are the electron beams with acceleration voltage at 300 kV or less. The typical examples are shown on manufactures in Japan, equipment configuration, operation, determination of process parameters, and basic maintenance requirement of the electron beam processors. New electron beam processors with acceleration voltage around 100 kV were introduced maintaining the relatively high dose speed capability of around 10,000 kGy x mpm at production by ESI (Energy Science Inc. USA, Iwasaki Electric Group). The application field like printing and coating for packaging requires treating thickness of 30 micron or less. It does not require high voltage over 110 kV. Also recently developed is a miniature bulb type electron beam tube with energy less than 60 kV. The new application area for this new electron beam tube is being searched. The drive force of this technology to spread in the industries would be further development of new application, process and market as well as the price reduction of the equipment, upon which further acknowledgement and acceptance of the technology to societies and industries would entirely depend. (Y. Tanaka)

Low voltage electron beam accelerators

Energy Technology Data Exchange (ETDEWEB)

Ochi, Masafumi [Iwasaki Electric Co., Ltd., Tokyo (Japan)

2003-02-01

Widely used electron accelerators in industries are the electron beams with acceleration voltage at 300 kV or less. The typical examples are shown on manufactures in Japan, equipment configuration, operation, determination of process parameters, and basic maintenance requirement of the electron beam processors. New electron beam processors with acceleration voltage around 100 kV were introduced maintaining the relatively high dose speed capability of around 10,000 kGy x mpm at production by ESI (Energy Science Inc. USA, Iwasaki Electric Group). The application field like printing and coating for packaging requires treating thickness of 30 micron or less. It does not require high voltage over 110 kV. Also recently developed is a miniature bulb type electron beam tube with energy less than 60 kV. The new application area for this new electron beam tube is being searched. The drive force of this technology to spread in the industries would be further development of new application, process and market as well as the price reduction of the equipment, upon which further acknowledgement and acceptance of the technology to societies and industries would entirely depend. (Y. Tanaka)

DC injection into low voltage AC networks

Energy Technology Data Exchange (ETDEWEB)

NONE

2005-07-01

This report summarises the results of a study investigating the impact of levels of injected DC current injections on a low voltage AC distribution network systems in order to recommend acceptable limits of DC from microgeneration. Relevant literature is reviewed, and the impact of DC levels in distribution transformers, transformer modelling, and instrumental transformers are discussed. The impact of DC in residual current devices (RCD) and in domestic electricity watt hour meters is examined along with DC enhanced corrosion, corrosion failure, and the measurement of DC current injection. Sources of DC injection outlined include DC from computer power supplies, network faults, geomagnetic phenomena, lighting circuits/dimmers, and embedded generators.

Communication Characteristics of Faulted Overhead High Voltage Power Lines at Low Radio Frequencies

Directory of Open Access Journals (Sweden)

Nermin Suljanović

2017-11-01

Full Text Available This paper derives a model of high-voltage overhead power line under fault conditions at low radio frequencies. The derived model is essential for design of communication systems to reliably transfer information over high voltage power lines. In addition, the model can also benefit advanced systems for power-line fault detection and classification exploiting the phenomenon of changed conditions on faulted power line, resulting in change of low radio frequency signal propagation. The methodology used in the paper is based on the multiconductor system analysis and propagation of electromagnetic waves over the power lines. The model for the high voltage power line under normal operation is validated using actual measurements obtained on 400 kV power line. The proposed model of faulted power lines extends the validated power-line model under normal operation. Simulation results are provided for typical power line faults and typical fault locations. Results clearly indicate sensitivity of power-line frequency response on different fault types.

Preparation for Retirement Seminar

CERN Multimedia

HR Department

2007-01-01

The Department of Human Resources is organising a preparation for retirement seminar which will take place on the four successive afternoons of 2 to 5 October 2007. Similar seminars in the past have always proved highly successful. Retirement marks the end of one’s working life and the start of a new period of life. This period of transition and change is experienced differently from one individual to another. In any case, being well-informed and prepared greatly facilitates the change in lifestyle. We would like to draw your attention to the following information: Staff concerned: All staff members aged 58 and above as well as those who have retired during the year have been sent a personal invitation to attend. Spouses are welcome. Staff members below 58 who are interested in attending the seminar may also apply. Their applications will be accepted subject to availability of places. Registration: In view of the number of people concerned and the limited capacity of th...

Preparation for Retirement Seminar

CERN Multimedia

HR Department

2011-01-01

The Human Resources Department is organizing a Preparation for Retirement Seminar, which will take place on 18 and 21 October 2011 in the afternoon in the Main Auditorium and on 19 October and 15 and 16 November 2011 in the afternoon in the Council Chamber. Similar seminars in the past have always proved highly successful. Retirement marks the end of a person’s working life and the start of a new chapter. This period of transition is experienced differently from one individual to another. In all cases, being well-informed and prepared greatly facilitates the change in lifestyle. We would like to draw your attention to the following information: Staff concerned: All staff members aged 58 and above have been sent a personal invitation to attend. Spouses are welcome. Staff members under the age of 58 who are interested in attending the seminar may also apply. Their applications will be accepted subject to availability of places. Registration: In view of the number of people concerned, you are ...

Preparation for Retirement Seminar

CERN Multimedia

HR Department

2009-01-01

The Human Resources Department is organizing a preparation for retirement seminar, which will take place on the afternoons of the 11, 13, 25 and 27 November 2009. Similar seminars in the past have always proved highly successful. Retirement marks the end of a person’s working life and the start of a new chapter. This period of transition is experienced differently from one individual to another. In all cases, being well-informed and prepared greatly facilitates the change in lifestyle. We would like to draw your attention to the following information: Staff concerned: All staff members aged 58 and above have been sent a personal invitation to attend. Spouses are welcome. Staff members below 58 who are interested in attending the seminar may also apply. Their applications will be accepted subject to availability of places. Registration: In view of the number of people concerned and the limited capacity of the main auditorium, you are requested to register in advance via ...

Preparation for Retirement Seminar

CERN Multimedia

HR Department

2009-01-01

The Human Resources Department is organizing a preparation for retirement seminar, which will take place in the afternoons of 11, 13, 25 and 27 November 2009. Similar seminars in the past have always proved highly successful. Retirement marks the end of a person’s working life and the start of a new chapter. This period of transition is experienced differently from one individual to another. In all cases, being well-informed and prepared greatly facilitates the change in lifestyle. We would like to draw your attention to the following information: Staff concerned: All staff members aged 58 and above have been sent a personal invitation to attend. Spouses are welcome. Staff members below 58 who are interested in attending the seminar may also apply. Their applications will be accepted subject to the availability of places. Registration: In view of the number of people concerned and the limited capacity of the Main Auditorium, you are requested to register in advance via Ind...

Preparation for Retirement Seminar

CERN Multimedia

HR Department

2009-01-01

The Human Resources Department is organizing a preparation for retirement seminar, which will take place on the afternoons of the 11, 13, 25 and 27 November 2009. Similar seminars in the past have always proved highly successful. Retirement marks the end of a person’s working life and the start of a new chapter. This period of transition is experienced differently from one individual to another. In all cases, being well-informed and prepared greatly facilitates the change in lifestyle. We would like to draw your attention to the following information: Staff concerned: All staff members aged 58 and above have been sent a personal invitation to attend. Spouses are welcome. Staff members below 58 who are interested in attending the seminar may also apply. Their applications will be accepted subject to the availability of places. Registration: In view of the number of people concerned and the limited capacity of the Main Auditorium, you are requested to register in advance ...

Preparation for Retirement Seminar

CERN Multimedia

HR Department

2009-01-01

The Human Resources Department is organizing a preparation for retirement seminar, which will take place on the afternoons of the 11, 13, 25 and 27 November 2009. Similar seminars in the past have always proved highly successful. Retirement marks the end of a person’s working life and the start of a new chapter. This period of transition is experienced differently from one individual to another. In all cases, being well-informed and prepared greatly facilitates the change in lifestyle. We would like to draw your attention to the following information: Staff concerned: All staff members aged 58 and above have been sent a personal invitation to attend. Spouses are welcome. Staff members under the age of 58 who are interested in attending the seminar may also apply. Their applications will be accepted subject to the availability of places. Registration: In view of the number of people concerned and the limited capacity of the Main Auditorium, you are requested to register ...

Preparation for retirement seminar

CERN Multimedia

HR Department

  The Human Resources Department is organizing a preparation for retirement seminar, which will take place on the afternoons of the 25 and 27 November 2009. Similar seminars in the past have always proved highly successful. Retirement marks the end of a person’s working life and the start of a new chapter. This period of transition is experienced differently from one individual to another. In all cases, being well-informed and prepared greatly facilitates the change in lifestyle. We would like to draw your attention to the following information: Staff concerned: All staff members aged 58 and above have been sent a personal invitation to attend. Spouses are welcome. Staff members under the age of 58 who are interested in attending the seminar may also apply. Their applications will be accepted subject to the availability of places. Registration: In view of the number of people concerned and the limited capacity of the Main Auditorium, you are requested to register in advance via Indico. &a...

Impressions from the 3rd Nordcode Seminar & Workshop

DEFF Research Database (Denmark)

Lenau, Torben Anker; Boelskifte, Per; Hansen, Claus Thorp

2005-01-01

This paper summarises the purpose and contents of the 3rd Nordcode Seminar and Workshop. First, the workshop assignments are described. Second, the paper briefly presents the topics of the keynote speeches and all presentations of the working papers that took place in the seminar.......This paper summarises the purpose and contents of the 3rd Nordcode Seminar and Workshop. First, the workshop assignments are described. Second, the paper briefly presents the topics of the keynote speeches and all presentations of the working papers that took place in the seminar....

Low voltage control for the liquid argon hadronic end-cap calorimeter of ATLAS

CERN Document Server

Brettel, H; Habring, J; Oberlack, H; Schacht, P

2002-01-01

At the ATLAS detector a SCADA system surveys and controls the sub- detectors. The link is realized by PVSS2 software and a CanBus hardware system. The low voltages for the Hadronic Endcaps of the liquid argon calorimeter are produced by DC/DC-converters in the power boxes and split into 320 channels corresponding to the pre- amplifier and summing boards in the cryostat. Six units of a prototype distribution board are currently under test. Each of it contains 2 ELMBs as CanBus interface, a FPGA of type QL3012 for digital control and 30 low voltage regulators for the individual fine adjustments of the outputs.

A training programme to build cancer research capacity in low- and middle-income countries: findings from Guatemala.

Science.gov (United States)

Arnold, Lauren D; Barnoya, Joaquin; Gharzouzi, Eduardo N; Benson, Peter; Colditz, Graham A

2014-04-01

Guatemala is experiencing an increasing burden of cancer but lacks capacity for cancer prevention, control and research. In partnership with a medical school in the United States of America, a multidisciplinary Cancer Control Research Training Institute was developed at the Instituto de Cancerología (INCAN) in Guatemala City. This institute provided a year-long training programme for clinicians that focused on research methods in population health and sociocultural anthropology. The programme included didactic experiences in Guatemala and the United States as well as applied training in which participants developed research protocols responsive to Guatemala's cancer needs. Although INCAN is the point of referral and service for Guatemala's cancer patients, the institute's administration is also interested in increasing cancer research - with a focus on population health. INCAN is thus a resource for capacity building within the context of cancer prevention and control. Trainees increased their self-efficacy for the design and conduct of research. Value-added benefits included establishment of an annual cancer seminar and workshops in cancer pathology and qualitative analysis. INCAN has recently incorporated some of the programme's components into its residency training and established a research department. A training programme for clinicians can build cancer research capacity in low- and middle-income countries. Training in population-based research methods will enable countries such as Guatemala to gather country-specific data. Once collected, such data can be used to assess the burden of cancer-related disease, guide policy for reducing it and identify priority areas for cancer prevention and treatment.

Low-voltage electroosmotic pumping using polyethylene terephthalate track-etched membrane

Energy Technology Data Exchange (ETDEWEB)

Wang Ceming; Wang Lin [State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871 (China); Xue Jianming, E-mail: jmxue@pku.edu.cn [State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871 (China); Center for Applied Physics and Technology, Peking University, Beijing 100871 (China)

2012-09-01

We present experimental investigations of electroosmotic (EO) pumping using polyethylene terephthalate (PET) track-etched membrane at a low applied voltage. An EO pump based on PET track-etched membrane has been designed and fabricated. Pumping performance of the device is experimentally studied in terms of flow rate as a function of applied voltage and KCl aqueous concentration. The PET track-etched membrane EO pump can generate flow rates on the order of 10 {mu}l min{sup -1} cm{sup -2} at several applied volts. The measured flow rate tends to decrease with increasing KCl aqueous concentration. In addition, we study the EO flow in cylindrical nanopore with use of a continuum model, composed of Nernst Planck equations, Poisson equation and Navier Stokes equations.

The Implementation of Research-based Learning on Biology Seminar Course in Biology Education Study Program of FKIP UMRAH

Science.gov (United States)

Amelia, T.

2018-04-01

Biology Seminar is a course in Biology Education Study Program of Faculty of Teacher Training and Education University of Maritim Raja Ali Haji (FKIP UMRAH) that requires students to have the ability to apply scientific attitudes, perform scientific writing and undertake scientific publications on a small scale. One of the learning strategies that can drive the achievement of learning outcomes in this course is Research-Based Learning. Research-Based Learning principles are considered in accordance with learning outcomes in Biology Seminar courses and generally in accordance with the purpose of higher education. On this basis, this article which is derived from a qualitative research aims at describing Research-based Learning on Biology Seminar course. Based on a case study research, it was known that Research-Based Learning on Biology Seminar courses is applied through: designing learning activities around contemporary research issues; teaching research methods, techniques and skills explicitly within program; drawing on personal research in designing and teaching courses; building small-scale research activities into undergraduate assignment; and infusing teaching with the values of researchers.

Methodology for the assessment of possible damages in low voltage equipment due to lightning surges

Energy Technology Data Exchange (ETDEWEB)

Matsuo, Nelson M.; Kagan, Nelson [University of Sao Paulo (USP), SP (Brazil)], Emails: matsuonm@usp.br, nelsonk@pea.usp.br; Domingues, Ivo T. [AES Eletropaulo, SP (Brazil); Jesus, Nelson C. de [AES Sul, Porto Alegre, RS (Brazil); Silva, Marcelo H.I. da [Grupo Rede, Sao Paulo, SP (Brazil); Takauti, Edson H. [Bandeirante, Sao Paulo, SP (Brazil)

2007-07-01

This paper deals with the development of a methodology to assess the possibility of equipment damages in low voltage customers due to lightning surges. The main objective is to incorporate this methodology in a computation system that supports distribution companies to determine the possible causes of equipment damages claimed by customers and to decide whether the claims are to be reimbursed or not. The proposed methodology determines whether a specific customer could be affected by a lightning strike according to his/her location and to the lightning main parameters, by using data from a lightning detection system and from the specific equipment surge withstand capability. A specific study using ATP (Alternative Transients Program) was carried out to assess the propagation of lightning surges in electric power distribution systems and their impact over low voltage customers. On the other hand, the withstand capability of the main household appliances was determined by a series of tests carried out in the University's power quality laboratory. The paper details the modeling used for simulation, such as network configuration, grounding points, and modelling of insulator flashover, distribution transformer, low voltage loads. It also presents some results regarding the evaluation of over voltages in low voltage customers installations. A practical method is proposed for assessing the possibility of equipment damage and describes how the existing uncertainties were handled. Also, some issues regarding the withstand capability of electric household appliances to lightning surges are discussed and some results of the laboratory tests are presented. (author)

Report and analysis of S-cube. Super science seminar

International Nuclear Information System (INIS)

Isogai, Kentaro; Yasuhara, Yuko

2004-04-01

At the ITBL Promotion Office, the science seminar (S-cube: Super Science Seminar) which was held for the first time on Wed., October 30, 2002 has been held more than 50 times. Lectures have been invited from many universities and research organizations. Seminars have been held which are of interest to junior high school students and high school students. In this article, in addition to introducing the seminars that have been held, attention is paid to the theme of the seminars, and what management considerations are necessary in order to increase participants in the future. (author)

Evolution of graphene nanoribbons under low-voltage electron irradiation

KAUST Repository

Zhu, Wenpeng

2012-01-01

Though the all-semiconducting nature of ultrathin graphene nanoribbons (GNRs) has been demonstrated in field-effect transistors operated at room temperature with ∼10⁵ on-off current ratios, the borderline for the potential of GNRs is still untouched. There remains a great challenge in fabricating even thinner GNRs with precise width, known edge configurations and specified crystallographic orientations. Unparalleled to other methods, low-voltage electron irradiation leads to a continuous reduction in width to a sub-nanometer range until the occurrence of structural instability. The underlying mechanisms have been investigated by the molecular dynamics method herein, combined with in situ aberration-corrected transmission electron microscopy and density functional theory calculations. The structural evolution reveals that the zigzag edges are dynamically more stable than the chiral ones. Preferential bond breaking induces atomic rings and dangling bonds as the initial defects. The defects grow, combine and reconstruct to complex edge structures. Dynamic recovery is enhanced by thermal activation, especially in cooperation with electron irradiation. Roughness develops under irradiation and reaches a plateau less than 1 nm for all edge configurations after longtime exposure. These features render low-voltage electron irradiation an attractive technique in the fabrication of ultrathin GNRs for exploring the ultimate electronic properties. © 2012 The Royal Society of Chemistry.

Reviving Graduate Seminar Series through Non-Technical Presentations

Science.gov (United States)

Madihally, Sundararajan V.

2011-01-01

Most chemical engineering programs that offer M.S. and Ph.D. degrees have a common seminar series for all the graduate students. Many would agree that seminars lack student interest, leading to ineffectiveness. We questioned the possibility of adding value to the seminar series by incorporating non-technical topics that may be more important to…

Increase the threshold voltage of high voltage GaN transistors by low temperature atomic hydrogen treatment

Energy Technology Data Exchange (ETDEWEB)

Erofeev, E. V., E-mail: erofeev@micran.ru [Tomsk State University of Control Systems and Radioelectronics, Research Institute of Electrical-Communication Systems (Russian Federation); Fedin, I. V.; Kutkov, I. V. [Research and Production Company “Micran” (Russian Federation); Yuryev, Yu. N. [National Research Tomsk Polytechnic University, Institute of Physics and Technology (Russian Federation)

2017-02-15

High-electron-mobility transistors (HEMTs) based on AlGaN/GaN epitaxial heterostructures are a promising element base for the fabrication of high voltage electronic devices of the next generation. This is caused by both the high mobility of charge carriers in the transistor channel and the high electric strength of the material, which makes it possible to attain high breakdown voltages. For use in high-power switches, normally off-mode GaN transistors operating under enhancement conditions are required. To fabricate normally off GaN transistors, one most frequently uses a subgate region based on magnesium-doped p-GaN. However, optimization of the p-GaN epitaxial-layer thickness and the doping level makes it possible to attain a threshold voltage of GaN transistors close to V{sub th} = +2 V. In this study, it is shown that the use of low temperature treatment in an atomic hydrogen flow for the p-GaN-based subgate region before the deposition of gate-metallization layers makes it possible to increase the transistor threshold voltage to V{sub th} = +3.5 V. The effects under observation can be caused by the formation of a dipole layer on the p-GaN surface induced by the effect of atomic hydrogen. The heat treatment of hydrogen-treated GaN transistors in a nitrogen environment at a temperature of T = 250°C for 12 h reveals no degradation of the transistor’s electrical parameters, which can be caused by the formation of a thermally stable dipole layer at the metal/p-GaN interface as a result of hydrogenation.

Increase the threshold voltage of high voltage GaN transistors by low temperature atomic hydrogen treatment

International Nuclear Information System (INIS)

Erofeev, E. V.; Fedin, I. V.; Kutkov, I. V.; Yuryev, Yu. N.

2017-01-01

High-electron-mobility transistors (HEMTs) based on AlGaN/GaN epitaxial heterostructures are a promising element base for the fabrication of high voltage electronic devices of the next generation. This is caused by both the high mobility of charge carriers in the transistor channel and the high electric strength of the material, which makes it possible to attain high breakdown voltages. For use in high-power switches, normally off-mode GaN transistors operating under enhancement conditions are required. To fabricate normally off GaN transistors, one most frequently uses a subgate region based on magnesium-doped p-GaN. However, optimization of the p-GaN epitaxial-layer thickness and the doping level makes it possible to attain a threshold voltage of GaN transistors close to V_t_h = +2 V. In this study, it is shown that the use of low temperature treatment in an atomic hydrogen flow for the p-GaN-based subgate region before the deposition of gate-metallization layers makes it possible to increase the transistor threshold voltage to V_t_h = +3.5 V. The effects under observation can be caused by the formation of a dipole layer on the p-GaN surface induced by the effect of atomic hydrogen. The heat treatment of hydrogen-treated GaN transistors in a nitrogen environment at a temperature of T = 250°C for 12 h reveals no degradation of the transistor’s electrical parameters, which can be caused by the formation of a thermally stable dipole layer at the metal/p-GaN interface as a result of hydrogenation.

An Optimized Reactive Power Control of Distributed Solar Inverters in Low Voltage Networks

DEFF Research Database (Denmark)

Demirok, Erhan; Sera, Dezso; Teodorescu, Remus

2011-01-01

This study examines the reactive power ancillary services of solar inverters which are connected to low voltage (LV) distribution networks by giving attention to the grid voltage support service and grid losses. Two typical reference LV distribution network models as suburban and farm...... are introduced from the literature in order to evaluate contribution of two static droop strategies cosφ(P) and Q(U) on the grid voltage. Photovoltaic (PV) hosting capacities of the suburban and farm networks are estimated and the most predominant limitations of connecting more solar inverters are emphasized...... for each network type. Regarding the overloading of MV/LV distribution transformers, overloading of lines and the grid overvoltage limitations, new local grid voltage support methods (cosφ(P,U) and Q(U,P)) are also proposed. Resulting maximum allowable penetration levels with different reactive power...

Towards low-voltage organic thin film transistors (OTFTs with solution-processed high-k dielectric and interface engineering

Directory of Open Access Journals (Sweden)

Yaorong Su

2015-11-01

Full Text Available Although impressive progress has been made in improving the performance of organic thin film transistors (OTFTs, the high operation voltage resulting from the low gate capacitance density of traditional SiO2 remains a severe limitation that hinders OTFTs'development in practical applications. In this regard, developing new materials with high-k characteristics at low cost is of great scientific and technological importance in the area of both academia and industry. Here, we introduce a simple solution-based technique to fabricate high-k metal oxide dielectric system (ATO at low-temperature, which can be used effectively to realize low-voltage operation of OTFTs. On the other hand, it is well known that the properties of the dielectric/semiconductor and electrode/semiconductor interfaces are crucial in controlling the electrical properties of OTFTs. By optimizing the above two interfaces with octadecylphosphonic acid (ODPA self-assembled monolayer (SAM and properly modified low-cost Cu, obviously improved device performance is attained in our low-voltage OTFTs. Further more, organic electronic devices on flexible substrates have attracted much attention due to their low-cost, rollability, large-area processability, and so on. Basing on the above results, outstanding electrical performance is achieved in flexible devices. Our studies demonstrate an effective way to realize low-voltage, high-performance OTFTs at low-cost.

A Low-Voltage Ride-Through Technique for Grid-Connected Converters with Reduced Power Transistors Stress

DEFF Research Database (Denmark)

Chen, Hsin-Chih; Lee, Chia-Tse; Cheng, Po-Tai

2016-01-01

With more and more distributed energy resources being installed in the utility grid, grid operators start imposing the low-voltage ride-through requirement on such systems to remain grid-connected and inject reactive and/or active current to support grid voltage during fault conditions. This pape...

MAGY: An innovative high voltage-low current power supply for gyrotron

International Nuclear Information System (INIS)

Siravo, Ugo; Alex, Juergen; Bader, Michael; Carpita, Mauro; Fasel, Damien; Gavin, Serge; Perez, Albert

2011-01-01

From the electrical point of view, the body and the anode of high power gyrotrons behave as capacitive loads. A highly dynamic power supply is, therefore, hard to achieve. The MAGY concept (Modulator for the Anode of a triode type GYrotron) embodies an innovative solution to manage the capacitive current ensuring a very low ripple on the output voltage. It consists of a series of independent, bi-directional and regulated DC sources. Compared to existing topologies, this solution requires a smaller number of power modules. It avoids internal high frequency modulation and simultaneously offers high resolution of the output voltage and a wide range of operating scenarios.

A novel water resistor divider with a coaxial low-voltage arm.

Science.gov (United States)

Jia, Wei; Chen, Weiqing; Mao, Congguang; Zeng, Jiangtao

2010-03-01

A new style high voltage resistor divider made of saline solution has been constructed and tested. A coaxial construction is used on the low-voltage arm, as the signal extraction electrode, which can increase the attenuation ratio of the divider. The time response of divider limited by the stray parameter also can be improved. Comparing the results of calibrated experiment with the commonly used equal size copper sulfate dividers, the new probe has nearly five times increase in the attenuation ratio. The time response of the new style divider in the dimension of 30 mm in diameter and 400 mm in length can reach to 1 ns.

Flexible and low-voltage integrated circuits constructed from high-performance nanocrystal transistors.

Science.gov (United States)

Kim, David K; Lai, Yuming; Diroll, Benjamin T; Murray, Christopher B; Kagan, Cherie R

2012-01-01

Colloidal semiconductor nanocrystals are emerging as a new class of solution-processable materials for low-cost, flexible, thin-film electronics. Although these colloidal inks have been shown to form single, thin-film field-effect transistors with impressive characteristics, the use of multiple high-performance nanocrystal field-effect transistors in large-area integrated circuits has not been shown. This is needed to understand and demonstrate the applicability of these discrete nanocrystal field-effect transistors for advanced electronic technologies. Here we report solution-deposited nanocrystal integrated circuits, showing nanocrystal integrated circuit inverters, amplifiers and ring oscillators, constructed from high-performance, low-voltage, low-hysteresis CdSe nanocrystal field-effect transistors with electron mobilities of up to 22 cm(2) V(-1) s(-1), current modulation >10(6) and subthreshold swing of 0.28 V dec(-1). We fabricated the nanocrystal field-effect transistors and nanocrystal integrated circuits from colloidal inks on flexible plastic substrates and scaled the devices to operate at low voltages. We demonstrate that colloidal nanocrystal field-effect transistors can be used as building blocks to construct complex integrated circuits, promising a viable material for low-cost, flexible, large-area electronics.

Flexible Demand Control to Enhance the Dynamic Operation of Low Voltage Networks

DEFF Research Database (Denmark)

Diaz de Cerio Mendaza, Iker; Szczesny, Ireneusz Grzegorz; Pillai, Jayakrishnan Radhakrishna

2015-01-01

Moving towards a carbon free energy system has become an objective for many countries nowadays. Among other changes, the electrification of strategic sectors such as heating and transportation is inevitable. As a consequence, the current power system load will substantially increase...... for controlling the demand response of a low voltage grid. This is designed to; i) maximize the grid utilization, thereby reducing the need for reinforcement, ii) accommodate the maximum number of flexible loads and iii) satisfy the power and comfort requirements from each of the consumers in the network....... In this context, the nature of the expected loads (heat pumps, plug-in electric vehicles, etc.) makes the low voltage networks specially targeted. A promising solution to overcome the challenges resulting from their grid integration, is demand response. This paper introduces a hierarchical structure...

A novel on-chip high to low voltage power conversion circuit

International Nuclear Information System (INIS)

Wang Hui; Wang Songlin; Mou Zaixin; Guo Baolong; Lai Xinquan; Ye Qiang; Li Xianrui

2009-01-01

A novel power supply transform technique for high voltage IC based on the TSMC 0.6 μm BCD process is achieved. An adjustable bandgap voltage reference is presented which is different from the traditional power supply transform technique. It can be used as an internal power supply for high voltage IC by using the push-pull output stage to enhance its load capability. High-order temperature compensated circuit is designed to ensure the precision of the reference. Only 0.01 mm 2 area is occupied using this novel power supply technique. Compared with traditional technique, 50% of the area is saved, 40% quiescent power loss is decreased, and the temperature coefficient of the reference is only 4.48 ppm/deg. C. Compared with the traditional LDO (low dropout) regulator, this power conversion architecture does not need external output capacitance and decreases the chip-pin and external components, so the PCB area and design cost are also decreased. The testing results show that this circuit works well.

A novel on-chip high to low voltage power conversion circuit

Energy Technology Data Exchange (ETDEWEB)

Wang Hui; Wang Songlin; Mou Zaixin; Guo Baolong [Institute of Mechano-electronic Engineering, Xidian University, Xi' an 71007 (China); Lai Xinquan; Ye Qiang; Li Xianrui, E-mail: whui94@126.co [Institute of Electronic CAD, Xidian University, Xi' an 710071 (China)

2009-03-15

A novel power supply transform technique for high voltage IC based on the TSMC 0.6 mum BCD process is achieved. An adjustable bandgap voltage reference is presented which is different from the traditional power supply transform technique. It can be used as an internal power supply for high voltage IC by using the push-pull output stage to enhance its load capability. High-order temperature compensated circuit is designed to ensure the precision of the reference. Only 0.01 mm{sup 2} area is occupied using this novel power supply technique. Compared with traditional technique, 50% of the area is saved, 40% quiescent power loss is decreased, and the temperature coefficient of the reference is only 4.48 ppm/deg. C. Compared with the traditional LDO (low dropout) regulator, this power conversion architecture does not need external output capacitance and decreases the chip-pin and external components, so the PCB area and design cost are also decreased. The testing results show that this circuit works well.

Charge-pump voltage converter

Science.gov (United States)

Brainard, John P [Albuquerque, NM; Christenson, Todd R [Albuquerque, NM

2009-11-03

A charge-pump voltage converter for converting a low voltage provided by a low-voltage source to a higher voltage. Charge is inductively generated on a transfer rotor electrode during its transit past an inductor stator electrode and subsequently transferred by the rotating rotor to a collector stator electrode for storage or use. Repetition of the charge transfer process leads to a build-up of voltage on a charge-receiving device. Connection of multiple charge-pump voltage converters in series can generate higher voltages, and connection of multiple charge-pump voltage converters in parallel can generate higher currents. Microelectromechanical (MEMS) embodiments of this invention provide a small and compact high-voltage (several hundred V) voltage source starting with a few-V initial voltage source. The microscale size of many embodiments of this invention make it ideally suited for MEMS- and other micro-applications where integration of the voltage or charge source in a small package is highly desirable.

Astronomy Research Seminars

Science.gov (United States)

Genet, Russell M.

2018-06-01

Astronomy Research Seminars are offered by a rapidly growing number of community colleges and universities. Over the past decade some 120 student team research papers have been published with approximately 500 coauthors. Each team manages their own research, obtains and analyzes original data, writes a team paper, obtains an external review, submits their paper for publication, and gives a public PowerPoint presentation. The student teams are supported by: (1) an extensive community-of-practice which consists of professional and amateur astronomers, educators, and Seminar graduates; (2) the Institute for Student Astronomical Research (www.in4star.org); (3) the Small Telescope Astronomy Research Handbook and (4) an in-person/online, open-source Canvas learning management system with videos, quizzes, and other, extensive supporting material. Team research projects are completed in a semester or less and are managed by the students themselves. The Seminars have expanded from double star astronomy to asteroid astrometry, eclipsing binary times of minima, and exoplanet transits. Conducting authentic research inspires students, provides them with important skills in teamwork, project management and scientific literacy, and gives them confidence in their abilities to participate in scientific research. Being coauthors of published papers boosts student educational careers with respect to admissions and scholarships.

An optimized low-power voltage controlled oscillator

Science.gov (United States)

Shah, Kriyang; Le, Hai Phuong; Singh, Jugdutt

2007-01-01

This paper presents an optimised low-power low-phase-noise Voltage Controlled Oscillator (VCO) for Bluetooth wireless applications. The system level design issues and tradeoffs related to Direct Conversion Receiver (DCR) and Low Intermediate Frequency (IF) architecture for Bluetooth are discussed. Subsequently, for a low IF architecture, the critical VCO performance parameters are derived from system specifications. The VCO presented in the paper is optimised by implementing a novel biasing circuit that employs two current mirrors, one at the top and the other one at the bottom of the cross-coupled complementary VCO, to give the exact replica of the current in both the arms of current mirror circuit. This approach, therefore, significantly reduces the system power consumption as well as improves the system performance. Results show that, the VCO consumes only 281μW of power at 2V supply. Its phase noise performance are -115dBc/Hz, -130dBc/Hz and -141dBc/Hz at the offset frequency of 1MHz, 3MHz and 5MHz respectively. Results indicate that 31% reduction in power consumption is achieved as compared to the traditional VCO design. These characteristics make the designed VCO a better candidate for Bluetooth wireless application where power consumption is the major issue.

Control Strategy of Three-Phase Photovoltaic Inverter under Low-Voltage Ride-Through Condition

Directory of Open Access Journals (Sweden)

Xianbo Wang

2015-01-01

Full Text Available The new energy promoting community has recently witnessed a surge of developments in photovoltaic power generation technologies. To fulfill the grid code requirement of photovoltaic inverter under low-voltage ride-through (LVRT condition, by utilizing the asymmetry feature of grid voltage, this paper aims to control both restraining negative sequence current and reactive power fluctuation on grid side to maintain balanced output of inverter. Two mathematical inverter models of grid-connected inverter containing LCL grid-side filter under both symmetrical and asymmetric grid are proposed. PR controller method is put forward based on inverter model under asymmetric grid. To ensure the stable operation of the inverter, grid voltage feedforward method is introduced to restrain current shock at the moment of voltage drop. Stable grid-connected operation and LVRT ability at grid drop have been achieved via a combination of rapid positive and negative sequence component extraction of accurate grid voltage synchronizing signals. Simulation and experimental results have verified the superior effectiveness of our proposed control strategy.

Lectures Abandoned: Active Learning by Active Seminars

DEFF Research Database (Denmark)

Christensen, Henrik Bærbak; Corry, Aino Vonge

2012-01-01

Traditional lecture-based courses are widely criticised for be- ing less eective in teaching. The question is of course what should replace the lectures and various active learning tech- niques have been suggested and studied. In this paper, we report on our experiences of redesigning a software ......- tive seminars as a replacement of traditional lectures, an activity template for the contents of active seminars, an ac- count on how storytelling supported the seminars, as well as reports on our and the students' experiences....

Proceedings of the fifth NUCEF seminar

International Nuclear Information System (INIS)

2001-12-01

The Fifth NUCEF Seminar was held at Tokai Research Establishment, JAERI on February 27, 2001. The NUCEF Seminar aims at the promotion of effective researches and encouragement of research cooperation through the discussions and information exchanges by researchers in the field of the nuclear fuel cycle back-end. This seminar was divided into the following sessions: TRU Chemistry, Radioactive Waste Management, Criticality Safety and Partitioning/Reprocessing. At the panel discussion, important issues connected with the safety research for radioactive waste management were discussed among five speakers from the relevant organization in Japan. The 36 of the presented papers are indexed individually. (J.P.N.)

Study on Control Scheme for the Inverters in Low Voltage Microgrid with Nonlinear Loads

Science.gov (United States)

Xu, Jiqiang; Lu, Wenzhou; Wu, Lei

2017-05-01

There are a lot of nonlinear loads in real low voltage microgrid system. It will cause serious output voltage and grid current harmonic distortions problems in island and grid-connected modes, respectively. To solve this problem, this paper proposes a droop control scheme with quasi-proportion and resonant (quasi-PR) controller based on αβ stationary reference frame to make microgrid smoothly switch between grid-connected and island modes without changing control method. Moreover, in island mode, not only stable output voltage and frequency, but also reduced output voltage harmonics with added nonlinear loads can be achieved; In grid-connected mode, not only constant power, but also reduced grid current harmonics can be achieved. Simulation results verify the effectiveness of the proposed control scheme.

Coronary Computed Tomographic Angiography at Low Concentration of Contrast Agent and Low Tube Voltage in Patients with Obesity:: A Feasibility Study.

Science.gov (United States)

Pan, Yu-Ning; Li, Ai-Jing; Chen, Xiao-Min; Wang, Jian; Ren, Da-Wei; Huang, Qiu-Li

2016-04-01

Using lower tube voltage can reduce the exposure to radiation and the dose of contrast agent. However, lower tube voltage is often linked to more noise and poor image quality, which create a need for more effective technology to resolve this problem. To explore the feasibility of coronary computed tomographic angiography (CCTA) in patients with obesity at low tube voltage (100 kV) and low contrast agent concentration (270 mg/mL) using iterative reconstruction. A total of 48 patients with body mass index greater than 30 kg/m(2) were included and randomly divided into two groups. Group A received a traditional protocol (iopromide 370 mg/mL + 120 kV); group B received a protocol with low tube voltage (100 kV), low contrast agent concentration (270 mg/mL), and iterative reconstruction. The effective dose (ED), average attenuation values, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), the figure of merit (FOM), image quality scores, and the total iodine intake were compared. No significant differences in average CT attenuations, SNR, CNR, and subjective scores were noticed between the two groups (P > 0.05), whereas the FOM of group B was significantly higher than that of group A. Effective radiation dose, total iodine, and iodine injection rate in group B were lower than those of group A (P contrast agent with low iodine concentration and low-dose CCTA were feasible. Substantial reduction in radiation dose and the iodine intake could be achieved without compromising the image quality. Copyright © 2016 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

Ultra-Low Voltage Sixth-Order Low Pass Filter for Sensing the T-Wave Signal in ECGs

Directory of Open Access Journals (Sweden)

Panagiotis Bertsias

2014-11-01

Full Text Available An ultra-low voltage sixth-order low pass filter topology, suitable for sensing the T-wave signal in an electrocardiogram (ECG, is presented in this paper. This is realized using a cascade connection of second-order building blocks constructed from a sinh-domain two-integrator loop. The performance of the filter has been evaluated using the Cadence Analog Design Environment and the design kit provided by the Austria Mikro Systeme (AMS 0.35-µm CMOS process. The power consumption of filters was 7.21 nW, while a total harmonic distortion (THD level of 4% was observed for an input signal of 220 pA. The RMS value of the input referred noise was 0.43 pA, and the simulated value of the dynamic range (DR was 51.1 dB. A comparison with already published counterparts shows that the proposed topology offers the benefits of 0.5-V supply voltage operation and significantly improved power efficiency.

Coordinated control for low voltage ride-through of a PMSG-based wind power plant

Directory of Open Access Journals (Sweden)

Khagendra Thapa

2016-01-01

Full Text Available Wind turbine generators should be kept connected to a power grid, while supporting the voltage recovery in the case of a grid fault to meet low voltage ride-through requirement in some grid codes. This paper proposes a coordinated control scheme that prevents the increase in the DC-link voltage by reducing the active power in the machine side converter of permanent magnet synchronous generators (PMSGs in proportion to the voltage dip at the terminal of PMSGs. The proposed scheme changes the current priorities from the active current to the reactive current to inject more reactive power for a severe fault depending on the voltage dip. In addition, the grid-side converter operates in a voltage control mode with the slope, which is the ratio of reactive current capability to the voltage tolerance around a rated value. Moreover, during the fault, the slope is changed depending on the voltage dip to inject more reactive current. The performance of the proposed scheme is validated for a wind power plant consisting of 20 units of 5-MW PMSGs using an EMTP-RV simulator. The results demonstrate that the scheme enables the PMSGs not only to survive during the fault, but also to provide a dynamic reactive power support.

Fully on-chip switched capacitor NMOS low dropout voltage regulator

CERN Document Server

Camacho, D; Camacho, Daniel; Moreira, Paulo

2010-01-01

This paper presents a 1.5 V 50 mA low dropout voltage (LDO) regulator using an NMOS transistor as the output pass element. Continuous time,operation of the LDO is achieved using a new switched floating capacitor scheme that raises the gate voltage of the pass element. The regulator has a 0.2 V dropout at a 50 mA load and is stable for a wide load current range with loading capacitances up to 50 pF. The output variation when a full load step is applied is 300 mV and the recovery time is below 0.3 mu s. it is designed in a 0.13 mu m CMOS process with an area of 0.008 mm(2) and its operation does not require any external component.

Low Actuating Voltage Spring-Free RF MEMS SPDT Switch

Directory of Open Access Journals (Sweden)

Deepak Bansal

2016-01-01

Full Text Available RF MEMS devices are known to be superior to their solid state counterparts in terms of power consumption and electromagnetic response. Major limitations of MEMS devices are their low switching speed, high actuation voltage, larger size, and reliability. In the present paper, a see-saw single pole double throw (SPDT RF MEMS switch based on anchor-free mechanism is proposed which eliminates the above-mentioned disadvantages. The proposed switch has a switching time of 394 nsec with actuation voltage of 5 V. Size of the SPDT switch is reduced by utilizing a single series capacitive switch compared to conventional switches with capacitive and series combinations. Reliability of the switch is improved by adding floating metal and reducing stiction between the actuating bridge and transmission line. Insertion loss and isolation are better than −0.6 dB and −20 dB, respectively, for 1 GHz to 20 GHz applications.

Bringing explicit insight into cognitive psychology features during clinical reasoning seminars: a prospective, controlled study.

Science.gov (United States)

Nendaz, Mathieu R; Gut, Anne M; Louis-Simonet, Martine; Perrier, Arnaud; Vu, Nu V

2011-04-01

Facets of reasoning competence influenced by an explicit insight into cognitive psychology features during clinical reasoning seminars have not been specifically explored. This prospective, controlled study, conducted at the University of Geneva Faculty of Medicine, Switzerland, assessed the impact on sixth-year medical students' patient work-up of case-based reasoning seminars, bringing them explicit insight into cognitive aspects of their reasoning. Volunteer students registered for our three-month Internal Medicine elective were assigned to one of two training conditions: standard (control) or modified (intervention) case-based reasoning seminars. These seminars start with the patient's presenting complaint and the students must ask the tutor for additional clinical information to progress through case resolution. For this intervention, the tutors made each step explicit to students and encouraged self-reflection on their reasoning processes. At the end of their elective, students' performances were assessed through encounters with two standardized patients and chart write-ups. Twenty-nine students participated, providing a total of 58 encounters. The overall differences in accuracy of the final diagnosis given to the patient at the end of the encounter (control 63% vs intervention 74%, p = 0.53) and of the final diagnosis mentioned in the patient chart (61% vs 70%, p = 0.58) were not statistically significant. The students in the intervention group significantly more often listed the correct diagnosis among the differential diagnoses in their charts (75% vs 97%, p = 0.02). This case-based clinical reasoning seminar intervention, designed to bring students insight into cognitive features of their reasoning, improved aspects of diagnostic competence.

Low voltage operation of IGZO thin film transistors enabled by ultrathin Al2O3 gate dielectric

Science.gov (United States)

Ma, Pengfei; Du, Lulu; Wang, Yiming; Jiang, Ran; Xin, Qian; Li, Yuxiang; Song, Aimin

2018-01-01

An ultrathin, 5 nm, Al2O3 film grown by atomic-layer deposition was used as a gate dielectric for amorphous indium-gallium-zinc oxide (a-IGZO) thin-film transistors (TFTs). The Al2O3 layer showed a low surface roughness of 0.15 nm, a low leakage current, and a high breakdown voltage of 6 V. In particular, a very high gate capacitance of 720 nF/cm2 was achieved, making it possible for the a-IGZO TFTs to not only operate at a low voltage of 1 V but also exhibit desirable properties including a low threshold voltage of 0.3 V, a small subthreshold swing of 100 mV/decade, and a high on/off current ratio of 1.2 × 107. Furthermore, even under an ultralow operation voltage of 0.6 V, well-behaved transistor characteristics were still observed with an on/off ratio as high as 3 × 106. The electron transport through the Al2O3 layer has also been analyzed, indicating the Fowler-Nordheim tunneling mechanism.

Food irradiation seminar: Asia and the Pacific

International Nuclear Information System (INIS)

Mitchell, G.E.

1986-01-01

The report covers the Seminar for Asia and the Pacific on the practical application of food irradiation. The seminar assessed the practical application of food irradiation processes, commercial utilisation and international trade of irradiated food

Interpolation by a prime factor other than 2 in low-voltage low-power ΣΔ DAC

DEFF Research Database (Denmark)

Pracný, Peter; Jørgensen, Ivan Harald Holger; Chen, Liang

2013-01-01

This paper presents power optimization of a sigma-delta (ΣΔ) modulator based digital-to-analog converter (DAC) for hearing-aid audio back-end application. In a number of state-of-the-art publications the oversampling ratio (OSR) of the ΣΔ modulator is chosen as a factor of integer power of two...... optimization approach can be used for other low voltage low power portable audio applications (mobile phones, notebook computers etc.)....

Climate technology initiative capacity building seminar: best practice in climate technology and energy efficiency in central and eastern Europe. Seminar Proceedings

Energy Technology Data Exchange (ETDEWEB)

Pichl, P [ed.

2000-08-01

The Capacity Building Seminar on 'Best Practice in Climate Technology and Energy Efficiency in Central and Eastern Europe', held 6-10 December 1999 in Marienthal/Ostritz in Germany, was a very successful event in the framework of the CLIMATE TECHNOLOGY INITIATIVE (CTI). One reason for that is that the seminar allowed delegates from 22 nations, from Kazakhstan to Estonia, come together for an exchange of opinions about 'Energy Efficiency and Climate Protection' and all related issues. A reason is that this seminar provided an excellent starting point for future networking in Central and Eastern Europe and Asia. The colleagues who got to know each other at the seminar will meet again in future workshops and seminars. They can now contact a colleague from abroad to get information about special questions of Energy Efficiency when they need it. A third reason - and the most important one for the entire co-operation within the CTI organisation - is the special character of the seminar as a starting point for multitude of activities on Energy Efficiency and Climate Protection. At the end of the Ostritz seminar eleven delegations stated that they would organise follow up workshops in their own countries to go deeper into the details and to co-operate on a higher level. It may be that these workshops will be followed by others in other European regions. (orig./GL)

Climate technology initiative capacity building seminar: best practice in climate technology and energy efficiency in central and eastern Europe. Seminar Proceedings

Energy Technology Data Exchange (ETDEWEB)

Pichl, P. [ed.

2000-08-01

The Capacity Building Seminar on 'Best Practice in Climate Technology and Energy Efficiency in Central and Eastern Europe', held 6-10 December 1999 in Marienthal/Ostritz in Germany, was a very successful event in the framework of the CLIMATE TECHNOLOGY INITIATIVE (CTI). One reason for that is that the seminar allowed delegates from 22 nations, from Kazakhstan to Estonia, come together for an exchange of opinions about 'Energy Efficiency and Climate Protection' and all related issues. A reason is that this seminar provided an excellent starting point for future networking in Central and Eastern Europe and Asia. The colleagues who got to know each other at the seminar will meet again in future workshops and seminars. They can now contact a colleague from abroad to get information about special questions of Energy Efficiency when they need it. A third reason - and the most important one for the entire co-operation within the CTI organisation - is the special character of the seminar as a starting point for multitude of activities on Energy Efficiency and Climate Protection. At the end of the Ostritz seminar eleven delegations stated that they would organise follow up workshops in their own countries to go deeper into the details and to co-operate on a higher level. It may be that these workshops will be followed by others in other European regions. (orig./GL)

Development of Amorphous/Microcrystalline Silicon Tandem Thin-Film Solar Modules with Low Output Voltage, High Energy Yield, Low Light-Induced Degradation, and High Damp-Heat Reliability

Directory of Open Access Journals (Sweden)

Chin-Yi Tsai

2014-01-01

Full Text Available In this work, tandem amorphous/microcrystalline silicon thin-film solar modules with low output voltage, high energy yield, low light-induced degradation, and high damp-heat reliability were successfully designed and developed. Several key technologies of passivation, transparent-conducting-oxide films, and cell and segment laser scribing were researched, developed, and introduced into the production line to enhance the performance of these low-voltage modules. A 900 kWp photovoltaic system with these low-voltage panels was installed and its performance ratio has been simulated and projected to be 92.1%, which is 20% more than the crystalline silicon and CdTe counterparts.

ORGANIZATIONAL METHODS OF SEMINAR-DISPUTE ON ECONOMICS SPECIALTIES

Directory of Open Access Journals (Sweden)

Tatiana ANDREEVA

2015-12-01

Full Text Available Actuality. The topic of teaching economic disciplines has always been relevant and useful. The article considers the technique of organization and of the seminar-dispute on economic subjects. In this paper there are also identified criteria for evaluating the participants of the seminar-dispute. Methods of teaching economic disciplines in higher education are held by holding lectures and seminars. The seminar provides an opportunity to determine the degree of independence and responsibility, to rise creativity in every student. The purpose is to disclose the main objectives of the seminar-dispute, which as a result of the preliminary work on the program material, the teacher and students are in a situation of direct active communication during performance of students on topics arising between discussion and generalizations by teacher, bu solving the problem of cognitive, developmental and educational character that imparted methodological and practical skills to students. Methods. Logical and descriptive, monographic, analysis and synthesis. Results. It should be concluded that in preparation for the seminar, students acquire the skills to work with the book, read the analysis, selection of the main and necessary speeches for the report, , and systematizing the selected materials. Students learn to clearly express their thoughts, work out the ability to speak without papers to prove their beliefs, to establish contact with the audience, etc. Accordingly, it is best to choose the topics of the seminar where the student must not only learn certain information, but also find a solution. One of the most popular forms of classes in the framework of methodological approaches to the teaching of economic disciplines is a seminar-dispute.

Decision Optimization for Power Grid Operating Conditions with High- and Low-Voltage Parallel Loops

Directory of Open Access Journals (Sweden)

Dong Yang

2017-05-01

Full Text Available With the development of higher-voltage power grids, the high- and low-voltage parallel loops are emerging, which lead to energy losses and even threaten the security and stability of power systems. The multi-infeed high-voltage direct current (HVDC configurations widely appearing in AC/DC interconnected power systems make this situation even worse. Aimed at energy saving and system security, a decision optimization method for power grid operating conditions with high- and low-voltage parallel loops is proposed in this paper. Firstly, considering hub substation distribution and power grid structure, parallel loop opening schemes are generated with GN (Girvan-Newman algorithms. Then, candidate opening schemes are preliminarily selected from all these generated schemes based on a filtering index. Finally, with the influence on power system security, stability and operation economy in consideration, an evaluation model for candidate opening schemes is founded based on analytic hierarchy process (AHP. And a fuzzy evaluation algorithm is used to find the optimal scheme. Simulation results of a New England 39-bus system and an actual power system validate the effectiveness and superiority of this proposed method.

Preparation for Retirement Seminar

CERN Multimedia

HR Department

2011-01-01

The Human Resources Department is organizing a Preparation for Retirement Seminar, which will take place on 18 and 21 October 2011 in the afternoon in the Main Auditorium and on 19 October and 15 and 16 November 2011 in the afternoon in the Council Chamber. Similar seminars in the past have always proved highly successful. Retirement marks the end of a person’s working life and the start of a new chapter. This period of transition is experienced differently from one individual to another. In all cases, being well-informed and prepared greatly facilitates the change in lifestyle. We would like to draw your attention to the following information: Staff concerned: All staff members aged 58 and above have been sent a personal invitation to attend. Spouses are welcome. Staff members under the age of 58 who are interested in attending the seminar may also apply. Their applications will be accepted subject to availability of places. Registration: In view of the number of people concerned, you are r...

Low driving voltage blue, green, yellow, red and white organic light-emitting diodes with a simply double light-emitting structure.

Science.gov (United States)

Zhang, Zhensong; Yue, Shouzhen; Wu, Yukun; Yan, Pingrui; Wu, Qingyang; Qu, Dalong; Liu, Shiyong; Zhao, Yi

2014-01-27

Low driving voltage blue, green, yellow, red and white phosphorescent organic light-emitting diodes (OLEDs) with a common simply double emitting layer (D-EML) structure are investigated. Our OLEDs without any out-coupling schemes as well as n-doping strategies show low driving voltage, e.g. white OLED, respectively. This work demonstrates that the low driving voltages and high efficiencies can be simultaneously realized with a common simply D-EML structure.

Proceedings of the 8. Nordic seminar on radioecology

Energy Technology Data Exchange (ETDEWEB)

Ilus, E [STUK (FI)

2002-04-01

This report contains proceedings of the 8th Nordic Seminar on Radioecology held on February 25-28, 2001 in Rovaniemi, Finland. The Seminar was arranged by STUK - Radiation and Nuclear Safety Authority of Finland and supported by the NKS. The Seminar was intended to be a 'final forum' of the four-year NKS radioecology project BOK-2, Radioecological and Environmental Consequences, which was focused on the consequences of releases of man-made radionuclides into the environment. The programme of the Seminar consisted of 3 invited lectures, 31 oral presentations and 22 poster presentations dealing with marine, terrestrial and freshwater radioecology, methods, foodstuffs, models, whole-body counting and doses to man. (au)

Low tube voltage computed tomography urography using low-concentration contrast media: Comparison of image quality in conventional computed tomography urography.

Science.gov (United States)

Hwang, Inpyeong; Cho, Jeong Yeon; Kim, Sang Youn; Oh, Seung-June; Ku, Ja Hyeon; Lee, Joongyup; Kim, Seung Hyup

2015-12-01

The aim of the present study was to investigate the feasibility and image quality of excretory CT urography performed using low iodine-concentration contrast media and low tube voltage. This prospective study enrolled 63 patients who undergoing CT urography. The subjects were randomized into two groups of an excretory phase CT urography protocol and received either 240 mg I/mL of contrast media and 80 kVp of tube voltage (low-concentration protocol, n=32) or 350 mg I/mL and 120 kVp (conventional protocol, n=31). Two readers qualitatively evaluated images for sharpness of the urinary tract, image noise, streak artifact and overall diagnostic acceptability. The mean attenuation, signal-to-noise ratio, contrast-to-noise ratio and figure of merit were measured in the urinary tract. The non-inferiority test assessed the diagnostic acceptability between the two protocol groups. The low-concentration protocol showed a significantly lower effective radiation dose (3.44 vs. 5.70 mSv, Pcontrast-to-noise ratio and figure of merit were significantly higher in the low-concentration protocol along the entire urinary tract (Pcontrast media, 80 kVp tube voltage and an iterative reconstruction algorithm is beneficial to reduce radiation dose and iodine load, and its objective image quality and subjective diagnostic acceptability is not inferior to that of conventional CT urography. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Synthesis of Pt nanoparticles as catalysts of oxygen reduction with microbubble-assisted low-voltage and low-frequency solution plasma processing

Science.gov (United States)

Horiguchi, Genki; Chikaoka, Yu; Shiroishi, Hidenobu; Kosaka, Shinpei; Saito, Morihiro; Kameta, Naohiro; Matsuda, Naoki

2018-04-01

In the preparation of metallic nanoparticles by conventional solution plasma (SP) techniques, unstable plasma emission becomes an issue when the voltage and frequency of the waves applied between two electrodes placed in solution are lowered to avoid the boiling of the solution. In this study, we confirm that, in the presence of microbubbles, plasma is generated stably at low voltage (440 V) and low frequency (50-100 Hz) and small-size (≤10 nm) Pt nanoparticles (PtNPs) are synthesized in succession using a flow cell. The smallest PtNPs, ∼3.3 nm in diameter, are obtained using half-wave rectification, a tungsten wire anode, and a platinum wire cathode. The PtNPs are characterized by X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, and thermogravimeter-differential thermal analysis. The oxygen reduction reaction (ORR) is investigated in 0.1 M HClO4 solution on carbon-supported PtNPs using a rotating ring-disk electrode. The catalytic activities per initial electrochemical active surface area of the carbon-supported PtNPs synthesized employing the low-voltage, low-frequency (LVLF)-SP technique is higher than that of the commercially available 20 wt% Pt on Vulcan XC-72R. These results indicate that the LVLF-SP technique is a promising approach to producing carbon-supported PtNPs that catalyze ORR with low energy consumption.

Ultra-low Voltage CMOS Cascode Amplifier

OpenAIRE

Lehmann, Torsten; Cassia, Marco

2000-01-01

In this paper, we design a folded cascode operational transconductance amplifier in a standard CMOS process, which has a measured 69 dB DC gain, a 2 MHz bandwidth and compatible input- and output voltage levels at a 1 V power supply. This is done by a novel Current Driven Bulk (CDB) technique, which reduces the MOST threshold voltage by forcing a constant current though the transistor bulk terminal. We also look at limitations and improvements of this CDB technique.

Ultra-low Voltage CMOS Cascode Amplifier

DEFF Research Database (Denmark)

Lehmann, Torsten; Cassia, Marco

2000-01-01

In this paper, we design a folded cascode operational transconductance amplifier in a standard CMOS process, which has a measured 69 dB DC gain, a 2 MHz bandwidth and compatible input- and output voltage levels at a 1 V power supply. This is done by a novel Current Driven Bulk (CDB) technique......, which reduces the MOST threshold voltage by forcing a constant current though the transistor bulk terminal. We also look at limitations and improvements of this CDB technique....

Protonic/electronic hybrid oxide transistor gated by chitosan and its full-swing low voltage inverter applications

Energy Technology Data Exchange (ETDEWEB)

Chao, Jin Yu [Shanxi Province Key Laboratory High Gravity Chemical Engineering, North University of China, Taiyuan 030051 (China); Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Zhu, Li Qiang, E-mail: lqzhu@nimte.ac.cn; Xiao, Hui [Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Yuan, Zhi Guo, E-mail: ncityzg@163.com [Shanxi Province Key Laboratory High Gravity Chemical Engineering, North University of China, Taiyuan 030051 (China)

2015-12-21

Modulation of charge carrier density in condensed materials based on ionic/electronic interaction has attracted much attention. Here, protonic/electronic hybrid indium-zinc-oxide (IZO) transistors gated by chitosan based electrolyte were obtained. The chitosan-based electrolyte illustrates a high proton conductivity and an extremely strong proton gating behavior. The transistor illustrates good electrical performances at a low operating voltage of ∼1.0 V such as on/off ratio of ∼3 × 10{sup 7}, subthreshold swing of ∼65 mV/dec, threshold voltage of ∼0.3 V, and mobility of ∼7 cm{sup 2}/V s. Good positive gate bias stress stabilities are obtained. Furthermore, a low voltage driven resistor-loaded inverter was built by using an IZO transistor in series with a load resistor, exhibiting a linear relationship between the voltage gain and the supplied voltage. The inverter is also used for decreasing noises of input signals. The protonic/electronic hybrid IZO transistors have potential applications in biochemical sensors and portable electronics.

Tungsten oxide proton conducting films for low-voltage transparent oxide-based thin-film transistors

International Nuclear Information System (INIS)

Zhang, Hongliang; Wan, Qing; Wan, Changjin; Wu, Guodong; Zhu, Liqiang

2013-01-01

Tungsten oxide (WO x ) electrolyte films deposited by reactive magnetron sputtering showed a high room temperature proton conductivity of 1.38 × 10 −4 S/cm with a relative humidity of 60%. Low-voltage transparent W-doped indium-zinc-oxide thin-film transistors gated by WO x -based electrolytes were self-assembled on glass substrates by one mask diffraction method. Enhancement mode operation with a large current on/off ratio of 4.7 × 10 6 , a low subthreshold swing of 108 mV/decade, and a high field-effect mobility 42.6 cm 2 /V s was realized. Our results demonstrated that WO x -based proton conducting films were promising gate dielectric candidates for portable low-voltage oxide-based devices.

IACTalks: an on-line archive of astronomy-related seminars

DEFF Research Database (Denmark)

Knapen, Johan H.; Pérez Prieto, Jorge A.; Shahbaz, Tariq

2012-01-01

We present IACTalks, a free and open access seminars archive (http://iactalks.iac.es) aimed at promoting astronomy and the exchange of ideas by providing high-quality scientific seminars to the astronomical community. The archive of seminars and talks given at the Instituto de Astrofi\\'isica de...

Seminar for Master's Thesis Projects: Promoting Students' Self-Regulation

Science.gov (United States)

Miedijensky, Shirley; Lichtinger, Einat

2016-01-01

This study presents a thesis seminar model aimed at promoting students' self-regulation. Students' perceptions regarding the contribution of the seminar to their learning process were characterized and the seminar's effect upon their self-regulation expressions was examined. Data was collected using questionnaires and analyzed thematically. The…

ZnO nanorod based low turn-on voltage LEDs with wide electroluminescence spectra

International Nuclear Information System (INIS)

Jha, S.K.; Kutsay, O.; Bello, I.; Lee, S.T.

2013-01-01

Light emitting diodes (LEDs) based on arrays of n-type ZnO Nanorods were fabricated on p-GaN films using a hydrothermal method. The LEDs emit mainly in blue and UV range of the light. Their current–Voltage (I–V) characteristics typically show a low leakage current (7.2 μA) and a high rectification ratio (3 5 5). Devices operate at a low turn-on voltage of ∼4.5 V. Photoluminescence (PL) and electroluminescence (EL) measurements suggest low density of ZnO defects; however, in some aspects density of interfacial defects still might be considerable in the studied devices. The PL emission is deconvoluted to three peaks that are located at wavelengths of 361, 381, and 397 nm, while the wide EL spectra are deconvoluted to five peaks appearing at 368, 385, 427, 474, and 515 nm. Near-band-edge (NBE) emission of p-GaN and n-ZnO was observed in both the PL and EL spectra. Deconvoluted EL spectra consist of a very wide green band with the peak at 515 nm and extending up to 650 nm (red), and a rarely reported EL emission at 474 nm. Origin of these emissions is discussed, herein. The electrical characteristics together with EL characteristics indicate potential to develop and study p-GaN/n-ZnO nanorod LEDs for white emitting applications. - Highlights: ► A low turn-on voltage (4–4.5 V) and low threshold (5 V) electroluminescence from ZnO/GaN heterostructure. ► A wide spectrum EL emission (360–700 nm) suitable for white LED application. ► EL spectra consist of a rarely reported emission band with peak at 474 nm. ► Low-temperature and solution based fabrication, which is scalable and of low cost.

Proceedings of the fourth NUCEF seminar

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-07-01

The 4th NUCEF seminar was held at JAERI Tokai Establishment on 18 February 2000. The NUCEF seminar aims at the promotion of effective researches and the encouragement of research cooperation through the discussions and information exchanges by researchers in the field on the nuclear fuel cycle back-end. This seminar was divided in the following sessions: Criticality Safety, Reprocessing/Partitioning and Radioactive Waste Management. Especially, considering highly regrettable impact of the criticality accident at JCO, the Criticality Safety session including the Dose Evaluation focused on the evaluation of JCO Criticality Accident. This report compiles the papers presented and the related discussions. The 13 of the presented papers are indexed individually. (J.P.N.)

Expert judgements in performance assessments. Report of an SKI/SSI seminar

International Nuclear Information System (INIS)

Wilmot, R.D.; Galson, D.A.; Hora, S.C.

2000-09-01

give participants experience and insight into the advantages and disadvantages of one important means of making judgements in performance assessments. For the purposes of the trial elicitation exercises, participants formed two Working Groups to explore how elicitation could be used to derive numerical values and to make judgements concerning concepts or assumptions. The topics explored by the Working Groups were canister performance and cost calculations/longevity of funding. Prior to the elicitation exercises, the seminar included presentations to familiarise participants with the concepts of expert judgement and elicitation, and participants also undertook a training exercise on probability theory. This report presents summaries of the discussions held within the Working Groups. Key lessons learned by participants included the importance of appropriate training for experts prior to formal elicitation, the usefulness of the structured approach to decomposing problems into manageable issues, and the importance of clear problem definition. Although the concept of probability as a means of characterising uncertainty was unfamiliar to many participants, the potential for elicitation as one means of making judgements was recognised. Topics that participants felt could be considered for further work included the development of guidelines for elicitation, structured evaluation of canister failure modes, structured decision analysis in areas such as funding, and the use of probabilities and the treatment of uncertainty in the calculation of costs

Expert judgements in performance assessments. Report of an SKI/SSI seminar

Energy Technology Data Exchange (ETDEWEB)

Wilmot, R.D.; Galson, D.A. [Galson Sciences Ltd, Oakham (United Kingdom); Hora, S.C. [Univ. of Hawaii, Hilo, HI (United States)

2000-09-01

, designed to give participants experience and insight into the advantages and disadvantages of one important means of making judgements in performance assessments. For the purposes of the trial elicitation exercises, participants formed two Working Groups to explore how elicitation could be used to derive numerical values and to make judgements concerning concepts or assumptions. The topics explored by the Working Groups were canister performance and cost calculations/longevity of funding. Prior to the elicitation exercises, the seminar included presentations to familiarise participants with the concepts of expert judgement and elicitation, and participants also undertook a training exercise on probability theory. This report presents summaries of the discussions held within the Working Groups. Key lessons learned by participants included the importance of appropriate training for experts prior to formal elicitation, the usefulness of the structured approach to decomposing problems into manageable issues, and the importance of clear problem definition. Although the concept of probability as a means of characterising uncertainty was unfamiliar to many participants, the potential for elicitation as one means of making judgements was recognised. Topics that participants felt could be considered for further work included the development of guidelines for elicitation, structured evaluation of canister failure modes, structured decision analysis in areas such as funding, and the use of probabilities and the treatment of uncertainty in the calculation of costs.

Visual presentation of a medical physiology seminar modifies dental students' perception of its clinical significance.

Science.gov (United States)

Vuletic, L; Spalj, S; Peros, K

2016-02-01

The primary objective of this study was to assess whether exposing dental students to visual stimuli related to dental profession during the medical physiology seminar could affect their perception of the clinical relevance of the topic. A self-administered questionnaire on attitudes towards medical physiology was conducted amongst 105 students of the School of Dental Medicine in Zagreb, Croatia, aged 19-24 years (80% females) following a seminar on respiratory system physiology. Power-point presentation accompanying the seminar for a total of 52 students (study group) was enriched with pictures related to dental practice in order to assess whether these pictures could make the topic appear more clinically relevant for a future dentist. The results of the survey indicated that dental students in the study group perceived the topic of the seminar as more important for them as future dentists when compared to the perception of the control group (P = 0.025). The results of this survey encourage physiology lecturers to present medical physiology as clinically relevant for dental students whenever possible as this could increase students' interest in the subject and their motivation for learning. Such an approach could be particularly beneficial if there is a significant time gap between basic courses and involvement of students into clinical training for it could promote meaningful learning. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

POS 591: International Relations Seminar "The Modern World-System."

Science.gov (United States)

McGowan, Patrick J.

The syllabus outlines a college level international relations seminar with a neo-Marxist theoretical orientation. The objective of the seminar is to present an historical and comparative approach to a study of the evolution of the international political economy. Following an introduction explaining seminar objectives, grading, and course…

Report for fiscal 2000 on joint seminar for coal engineer training project; 2000 nendo sekitan gijutsusha yosei jigyo godo semina hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-09-01

This paper summarizes the contents of the joint seminar for coal engineer training project in fiscal 2000, which has been held in Tokyo on September 25, 2000. The lectures included 'Coal Resources in Gunnedah Basin - Future Coal Supply Potential and Geophysical Exploration' by Ms. Julie Ann Moloney, senior geographical engineer at NSW Department of Mineral Resources, Australia, 'Human Resources Development for Coal Mining in Indonesia' by Mr. Bangun Usman Harahap at the Ministry of Mines and Energy in Indonesia, 'Queensland Rail, a strategic partner - linking Coal Producers to World Markets' by Mr. John Stuart Burrows at Coal Queensland Rail, Australia, and 'The export coal mines of western Canada - A review' by Mr. Ron Smyth, director BC Geological Survey Branch, Ministry of Energy and Mines, British Columbia, Canada. Questions and answers were exchanged actively for these lectures. (NEDO)

Fueling strategies to optimize performance: training high or training low?

Science.gov (United States)

Burke, L M

2010-10-01

Availability of carbohydrate as a substrate for the muscle and central nervous system is critical for the performance of both intermittent high-intensity work and prolonged aerobic exercise. Therefore, strategies that promote carbohydrate availability, such as ingesting carbohydrate before, during and after exercise, are critical for the performance of many sports and a key component of current sports nutrition guidelines. Guidelines for daily carbohydrate intakes have evolved from the "one size fits all" recommendation for a high-carbohydrate diets to an individualized approach to fuel needs based on the athlete's body size and exercise program. More recently, it has been suggested that athletes should train with low carbohydrate stores but restore fuel availability for competition ("train low, compete high"), based on observations that the intracellular signaling pathways underpinning adaptations to training are enhanced when exercise is undertaken with low glycogen stores. The present literature is limited to studies of "twice a day" training (low glycogen for the second session) or withholding carbohydrate intake during training sessions. Despite increasing the muscle adaptive response and reducing the reliance on carbohydrate utilization during exercise, there is no clear evidence that these strategies enhance exercise performance. Further studies on dietary periodization strategies, especially those mimicking real-life athletic practices, are needed. © 2010 John Wiley & Sons A/S.

Proceedings of the 8. Nordic seminar on radioecology

Energy Technology Data Exchange (ETDEWEB)

Ilus, E. [STUK (FI)] (ed.)

2002-04-01

This report contains proceedings of the 8th Nordic Seminar on Radioecology held on February 25-28, 2001 in Rovaniemi, Finland. The Seminar was arranged by STUK - Radiation and Nuclear Safety Authority of Finland and supported by the NKS. The Seminar was intended to be a 'final forum' of the four-year NKS radioecology project BOK-2, Radioecological and Environmental Consequences, which was focused on the consequences of releases of man-made radionuclides into the environment. The programme of the Seminar consisted of 3 invited lectures, 31 oral presentations and 22 poster presentations dealing with marine, terrestrial and freshwater radioecology, methods, foodstuffs, models, whole-body counting and doses to man. (au)

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

Science.gov (United States)

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.

Fast Coordinated Control of DFIG Wind Turbine Generators for Low and High Voltage Ride-Through

Directory of Open Access Journals (Sweden)

Yun Wang

2014-06-01

Full Text Available This paper presents a fast coordinated control scheme of the rotor side converter (RSC, the Direct Current (DC chopper and the grid side converter (GSC of doubly fed induction generator (DFIG wind turbine generators (WTGs to improve the low voltage ride through (LVRT and high voltage ride through (HVRT capability of the DFIG WTGs. The characteristics of DFIG WTGs under voltage sags and swells were studied focusing on the DFIG WTG stator flux and rotor voltages during the transient periods of grid voltage changes. The protection schemes of the rotor crowbar circuit and the DC chopper circuit were proposed considering the characteristics of the DFIG WTGs during voltage changes. The fast coordinated control of RSC and GSC were developed based on the characteristic analysis in order to realize efficient LVRT and HVRT of the DFIG WTGs. The proposed fast coordinated control schemes were verified by time domain simulations using Matlab-Simulink.

Peer-led Stress Prevention Seminars in the First Year of Medical School – A Project Report

Directory of Open Access Journals (Sweden)

Bugaj, Till Johannes

2016-02-01

Full Text Available Introduction: From the beginning of the first year of medical studies, increased psychological stress and elevated burnout prevalence rates can be registered compared to sample populations. Characterized by learning “on an equal footing”, the principle of peer-assisted learning (PAL is widely used in medical education. This report aims to showcase the development and evaluation of peer-led stress prevention seminars for first year medical students after one year of implementation.Project description: With each of the three sessions lasting 90 min., the stress prevention seminars took place in small groups (6-10 students in the period from November 2013 to January 2014 and from November 2014 to December 2014 at the Medical Faculty of Heidelberg. Led by trained peers, the seminar content ranged from psycho-educational elements, i.e. time management strategy development and test anxiety assistance, to relaxation techniques. All seminar sessions were evaluated via questionnaire. All questions were answered on a Likert scale ranging from 1 to 7 (1=strongly agree; 7=strongly disagree.Results: 75 students consented to participate in seminars (65% female; aged 20.5±3.3 years. The series of seminars was averagely given the school grade of 1.2±0.4 (1=very good to 6=unsatisfactory in WS 2013/14 and 1.5±0.5 in the following year and the peer tutors’ competence was evaluated as very high (1.4 to 1.5 approval rate on the Likert scale.Discussion: The seminar sessions’ importance to the students is underlined by their very positive evaluations. This offer seems to have benefited students especially during the demanding transitional phase at the start of their studies. Both the implementation of the preventive measure at an early stage as well as the use of PAL seem to have proven effective.Conclusion: PAL seems to be effective in the field of stress prevention. However, specific efficacy studies are still lacking.

A low-voltage low-power 10-bit 200 MS/s pipelined ADC in 90 nm CMOS

NARCIS (Netherlands)

Abdinia, S.; Yavari, M.

2010-01-01

This paper presents a low-power 10-bit 200 MS/s pipelined ADC in a 90 nm CMOS technology with 1 V supply voltage. To decrease the power dissipation efficiently, a new architecture using a combination of two power reduction techniques named double-sampling and opamp-sharing has been used to reduce

Unbalanced Voltage Compensation in Low Voltage Residential AC Grids

DEFF Research Database (Denmark)

Trintis, Ionut; Douglass, Philip; Munk-Nielsen, Stig

2016-01-01

This paper describes the design and test of a control algorithm for active front-end rectifiers that draw power from a residential AC grid to feed heat pump loads. The control algorithm is able to control the phase to neutral or phase to phase RMS voltages at the point of common coupling...

Low Voltage Ride-Through Capability Solutions for Permanent Magnet Synchronous Wind Generators

Directory of Open Access Journals (Sweden)

Victor F. Mendes

2016-01-01

Full Text Available Due to the increasing number of wind power plants, several countries have modified their grid codes to include specific requirements for the connection of this technology to the power system. One of the requirements is the ride-through fault capability (RTFC, i.e., the system capability to sustain operation during voltage sags. In this sense, the present paper intends to investigate the behavior of a full-converter wind generator with a permanent magnet synchronous machine during symmetrical and asymmetrical voltage sags. Two solutions to improve the low voltage ride-through capability (LVRT of this technology are analyzed: discharging resistors (brake chopper and resonant controllers (RCs. The design and limitations of these solutions and the others proposed in the literature are discussed. Experimental results in a 34 kW test bench, which represents a scaled prototype of a real 2 MW wind conversion system, are presented.

A full on-chip CMOS low-dropout voltage regulator with VCCS compensation

International Nuclear Information System (INIS)

Gao Leisheng; Zhou Yumei; Wu Bin; Jiang Jianhua

2010-01-01

A full on-chip CMOS low-dropout (LDO) voltage regulator with high PSR is presented. Instead of relying on the zero generated by the load capacitor and its equivalent series resistance, the proposed LDO generates a zero by voltage-controlled current sources for stability. The compensating capacitor for the proposed scheme is only 0.18 pF, which is much smaller than the capacitor of the conventional compensation scheme. The full on-chip LDO was fabricated in commercial 0.35 μm CMOS technology. The active chip area of the LDO (including the bandgap voltage reference) is 400 x 270 μm 2 . Experimental results show that the PSR of the LDO is -58.7 dB at a frequency of 10 Hz and -20 dB at a frequency of 1 MHz. The proposed LDO is capable of sourcing an output current up to 50 mA. (semiconductor integrated circuits)

Fast Coordinated Control of DFIG Wind Turbine Generators for Low and High Voltage Ride-Through

DEFF Research Database (Denmark)

Wang, Yun; Wu, Qiuwei; Xu, Honghua

2014-01-01

This paper presents a fast coordinated control scheme of the rotor side converter (RSC), the DC chopper and the grid side converter (GSC) of doubly fed induction generator (DFIG) wind turbine generators (WTGs) which is to improve the low voltage ride through (LVRT) and high voltage ride through...... were proposed considering the characteristics of the DFIG WTGs during voltage changes. The fast coordinated control of RSC and GSC were developed based on the characteristic analysis in order to realize efficient LVRT and HVRT of the DFIG WTGs. The proposed fast coordinated control schemes were...

Proceedings of the third NUCEF seminar

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-06-01

The Third NUCEF Seminar was held at JAERI Tokai Establishment on 24 February 1998. This seminar was planned by researchers in JAERI for effective research promotion and cooperation, and researchers from both the inside and outside of JAERI presented one plenary session and 12 papers in the following three technical sessions: Criticality Safety, Reprocessing and Partitioning, and Radioactive Waste Management. (J.P.N.)

Single-nanowire, low-bandgap hot carrier solar cells with tunable open-circuit voltage

Science.gov (United States)

Limpert, Steven; Burke, Adam; Chen, I.-Ju; Anttu, Nicklas; Lehmann, Sebastian; Fahlvik, Sofia; Bremner, Stephen; Conibeer, Gavin; Thelander, Claes; Pistol, Mats-Erik; Linke, Heiner

2017-10-01

Compared to traditional pn-junction photovoltaics, hot carrier solar cells offer potentially higher efficiency by extracting work from the kinetic energy of photogenerated ‘hot carriers’ before they cool to the lattice temperature. Hot carrier solar cells have been demonstrated in high-bandgap ferroelectric insulators and GaAs/AlGaAs heterostructures, but so far not in low-bandgap materials, where the potential efficiency gain is highest. Recently, a high open-circuit voltage was demonstrated in an illuminated wurtzite InAs nanowire with a low bandgap of 0.39 eV, and was interpreted in terms of a photothermoelectric effect. Here, we point out that this device is a hot carrier solar cell and discuss its performance in those terms. In the demonstrated devices, InP heterostructures are used as energy filters in order to thermoelectrically harvest the energy of hot electrons photogenerated in InAs absorber segments. The obtained photovoltage depends on the heterostructure design of the energy filter and is therefore tunable. By using a high-resistance, thermionic barrier, an open-circuit voltage is obtained that is in excess of the Shockley-Queisser limit. These results provide generalizable insight into how to realize high voltage hot carrier solar cells in low-bandgap materials, and therefore are a step towards the demonstration of higher efficiency hot carrier solar cells.

Induction and Conduction Electromagnetic Waves Caused by Lightning Strike on the Low Voltage Network

Directory of Open Access Journals (Sweden)

Reynaldo Zoro

2010-10-01

Full Text Available Direct and indirect lightning strikes can disturb and induce low voltage overheadlines and it can produced overvoltage due to traveling waves along the lines. This overvoltage can damage the equipments connected to it. It was recorded that there were already a lot of damages of electronic equipments and arrestesr located inside the building of Lightning Measurement Station at Mnt. Tangkuban Perahu. Most of the overvoltage which was developed on the low voltage lines were coming from indirect lightning strike nearby due to the fact that most of the lines were covered by trees. Research was carried out to study and evaluate the induction and conduction of the lightning strikes to the LV lines that can lead to the cause of equipment and arrester damages inside the building. Local lightning data for the analysis were derived from measurement system installed at the stations and historical lightning data from lightning detection network called Jadpen (National Lightning Detection Network. The data was used for calculating and evaluating the voltage elevation, induction voltage profiles and conduction in the form of traveling waves using Rusck Model. Two damaged arresters were evaluated and compared and it give the better understanding on how the protection system work.Keywords: 

Peat Research Seminar

International Nuclear Information System (INIS)

1993-01-01

The VTT Seminar on Peat Research was held in Espoo, Finland, on April 14-15, 1993. The programme consisted of technical session on Peat in Energy Production, Peat Research Programs, Peat Production and Harvesting Technology

Ultra Low Voltage Class AB Switched Current Memory Cells Based on Floating Gate Transistors

DEFF Research Database (Denmark)

Mucha, Igor

1999-01-01

current memory cells were designed using a CMOS process with threshold voltages V-T0n = \\V-T0p\\ = 0.9 V for the n- and p-channel devices. Both hand calculations and PSPICE simulations showed that the designed example switched current memory cell allowed a maximum signal range better than +/-18 mu......A proposal for a class AB switched current memory cell, suitable for ultra-low-voltage applications is presented. The proposal employs transistors with floating gates, allowing to build analog building blocks for ultralow supply voltage operation also in CMOS processes with high threshold voltages....... This paper presents the theoretical basis for the design of "floating-gate'' switched current memory cells by giving a detailed description and analysis of the most important impacts degrading the performance of the cells. To support the theoretical assumptions circuits based on "floating-gate'' switched...

A Study on the Measurement of Ultrasound Velocity to Evaluate Degradation of Low Voltage Cables for Nuclear Power Plants

Energy Technology Data Exchange (ETDEWEB)

Kim, Kyung Cho; Kang, Suk Chull; Goo, Cheol Soo [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of); Kim, Jin Ho; Park, Jae Seok; Joo, Geum Jong; Park, Chi Seung [KAITEC, Seoul (Korea, Republic of)

2004-08-15

Several kinds of low voltage cables have been used in nuclear power plants for the supply of electric power, supervision, and the propagation of control signals. These low voltage tables must be inspected for safe and stable operation of nuclear power plants. In particular, the degradation diagnosis to estimate the integrity of low voltage rabies has recently been emphasized according to the long use of nuclear power plants. In order to evaluate their degradation, the surrounding temperature, hardness of insulation material, elongation at breaking point (EAB), etc. have been used. However, the measurement of temperature or hardness is not useful because of the absence of quantitative criteria; the inspection of a sample requires turning off of the power plant power; and, the electrical inspection method is not sufficiently sensitive from the initial through the middle stage of degradation. In this research, based on the theory that the ultrasonic velocity changes with relation to the degradation of the material, we measured the ultrasonic velocity as low voltage cables were degraded. To this end, an ultrasonic degradation diagnosis device was developed and used to measure the ultrasonic velocity with the clothing on the cable, and it was confirmed that the ultrasonic velocity changes according to the degradation of low voltage cables. The low voltage cables used in nuclear power plants were degraded at an accelerated rate, and EAB was measured in a tensile test conducted after the measurement of ultrasonic velocity. With the increasing degradation degree, the ultrasonic velocity decreased, whose potential as a useful parameter for the quantitative degradation evaluation was thus confirmed

Voltage control of a magnetic switching field for magnetic tunnel junctions with low resistance and perpendicular magnetic anisotropy

Science.gov (United States)

Tezuka, N.; Oikawa, S.; Matsuura, M.; Sugimoto, S.; Nishimura, K.; Irisawa, T.; Nagamine, Y.; Tsunekawa, K.

2018-05-01

The authors investigated the voltage control of a magnetic anisotropy field for perpendicular-magnetic tunnel junctions (p-MTJs) with low and high resistance-area (RA) products and for synthetic antiferromagnetic free and pinned layers. It was found that the sample with low RA products was more sensitive to the applied bias voltage than the sample with high RA products. The bias voltage effect was less pronounced for our sample with the synthetic antiferromagnetic layer for high RA products compared to the MTJs with single free and pinned layers.

Israel Seminar 2002-2003

CERN Document Server

Milman, Vitali D

2004-01-01

The Israeli GAFA seminar (on Geometric Aspect of Functional Analysis) during the years 2002-2003 follows the long tradition of the previous volumes. It reflects the general trends of the theory. Most of the papers deal with different aspects of the Asymptotic Geometric Analysis. In addition the volume contains papers on related aspects of Probability, classical Convexity and also Partial Differential Equations and Banach Algebras. There are also two expository papers on topics which proved to be very much related to the main topic of the seminar. One is Statistical Learning Theory and the other is Models of Statistical Physics. All the papers of this collection are original research papers.

Pre-employment job orientation seminar - after two years

International Nuclear Information System (INIS)

Petullo, C.F.

1988-01-01

Formerly, applicants for the Radiation Monitor job were primarily individuals with 4-yr degrees in the sciences or engineering, because of upgraded education requirements. Reynolds found, however, that they lost a very high percentage of such hirees within 4 months after training and going into the field - since they had felt they were hired for a white collar job. Therefore, they instituted the Pre-Employment Job Training Seminar for all applicants - a 40-minute slide presentation showing the Nevada Test Site Terrain; Radiation Monitor job locations such as tunnels, drill rigs, and a decontamination facility; and Radiation Monitors active in their job functions. In other words the earthy side of the job is depicted. Applicants still interested in the job after initial orientation stay for a 3-hour examination. The author expects future hiring at the technician level, with job requirements a high school diploma and science and math skills necessary for good job performance

Low-voltage organic field-effect transistors based on novel high-κ organometallic lanthanide complex for gate insulating materials

Directory of Open Access Journals (Sweden)

Qi Liu

2014-08-01

Full Text Available A novel high-κ organometallic lanthanide complex, Eu(tta3L (tta=2-thenoyltrifluoroacetonate, L = 4,5-pinene bipyridine, is used as gate insulating material to fabricate low-voltage pentacene field-effect transistors (FETs. The optimized gate insulator exhibits the excellent properties such as low leakage current density, low surface roughness, and high dielectric constant. When operated under a low voltage of −5 V, the pentacene FET devices show the attractive electrical performance, e.g. carrier mobility (μFET of 0.17 cm2 V−1 s−1, threshold voltage (Vth of −0.9 V, on/off current ratio of 5 × 103, and subthreshold slope (SS of 1.0 V dec−1, which is much better than that of devices obtained on conventional 300 nm SiO2 substrate (0.13 cm2 V−1 s−1, −7.3 V and 3.1 V dec−1 for μFET, Vth and SS value when operated at −30 V. These results indicate that this kind of high-κ organometallic lanthanide complex becomes a promising candidate as gate insulator for low-voltage organic FETs.

Preparing for retirement - new seminars

CERN Multimedia

Human Resources Department

2015-01-01

We would like to take the opportunity to inform you about a new programme related to retirement, organised by the Human Resources Department. Retirement marks the end of a career and the start of a new chapter in life.  In all cases, being well-informed and prepared is necessary to cope successfully with this transition. The programme has been developed for staff members and consists of two seminars: Leaving CERN (half day seminar): short presentations by internal speakers, focusing on what options CERN offers at the end of your career: organised once per year, next session scheduled on 24 November 2015, in the afternoon, enrolment and more information on Indico.   Preparation for retirement (2-day seminar): interactive workshop (in small groups) delivered by external experts, focusing on how to prepare psychologically as well as practically to cope with all the changes retirement brings: organised regularly in 2016, in English or ...

Low-voltage electricity-induced lung injury.

Science.gov (United States)

Truong, Thai; Le, Thuong Vu; Smith, David L; Kantrow, Stephen P; Tran, Van Ngoc

2018-02-01

We report a case of bilateral pulmonary infiltrates and haemoptysis following low-voltage electricity exposure in an agricultural worker. A 58-year-old man standing in water reached for an electric watering machine and sustained an exposure to 220 V circuit for an uncertain duration. The electricity was turned off by another worker, and the patient was asymptomatic for the next 10 h until he developed haemoptysis. A chest radiograph demonstrated bilateral infiltrates, and chest computed tomography (CT) revealed ground-glass opacities with interstitial thickening. Evaluations, including electrocardiogram, serum troponin, N-terminal pro-B-type natriuretic peptide (NT-pro BNP), coagulation studies, and echocardiogram, found no abnormality. The patient was treated for suspected electricity-induced lung injury and bleeding with tranexamic acid and for rhabdomyolysis with volume resuscitation. He recovered with complete resolution of chest radiograph abnormalities by Day 7. This is the first reported case of bilateral lung oedema and/or injury after electricity exposure without cardiac arrest.

Power quality issues into a Danish low-voltage grid with electric vehicles

DEFF Research Database (Denmark)

Marra, Francesco; Jensen, Morten M.; Garcia-Valle, Rodrigo

2011-01-01

An increased interest on electric vehicles (EVs) and plug-in hybrid electric vehicles (PHEVs) is dealing with their introduction into low voltage (LV) distribution grids. Lately, analysis on power quality issues has received attention when considering EVs as additional load. The charging of EVs...

Fully Integrated, Low Drop-Out Linear Voltage Regulator in 180 nm CMOS

DEFF Research Database (Denmark)

Yosef-Hay, Yoni; Larsen, Dennis Øland; Llimos Muntal, Pere

2017-01-01

This paper presents a capacitor-free low dropout (LDO) linear regulator based on a dual loop topology. The regulator utilizes two feedback loops to satisfy the challenges of hearing aid devices, which include fast transient performance and small voltage spikes under rapid load-current changes...

A structured approach to increase situational awareness in low voltage distribution grids

NARCIS (Netherlands)

Helmholt, K.A.; Groote Schaarsberg, M.; Broersma, T.; Morren, J.; Kruizinga, B.; Wouters, P.A.A.F.; Steennis, E.F.; Baldinger, F.

2015-01-01

Wear and tear, electrification and aging of (low voltage) distribution grids require maintenance in order to assure continuous provision of electricity. Situational awareness is required to find out when parts of the grid need maintenance and which parts should be prioritized. The paper proposes a

Integration of Electric Vehicles in Low Voltage Danish Distribution Grids

DEFF Research Database (Denmark)

Pillai, Jayakrishnan Radhakrishna; Thøgersen, Paul; Møller, Jan

2012-01-01

Electric Vehicles (EVs) are considered as one of the important components of the future intelligent grids. Their role as energy storages in the electricity grid could provide local sustainable solutions to support more renewable energy. In order to estimate the extent of interaction of EVs...... in the electricity grid operation, a careful examination in the local electricity system is essential. This paper investigates the degree of EV penetration and its key influence on the low voltage distribution grids. Three detailed models of residential grids in Denmark are considered as test cases in this study...... it is shown that there is enough head-space on the transformer capacity which can be used to charge many EVs during a day. The overall transformer capability of handling EV loads varies between 6-40% for peak and minimum demand hours, which is dependent on the robustness of the grids. The voltage drops...

JSPS-CAS Core University Program seminar. Proceedings of Japan-China joint seminar on atomic and molecular processes in plasma

International Nuclear Information System (INIS)

Koike, Fumihiro; Dong Chenzhong

2010-02-01

As one of the activities of JSPS-CAS Core University Program, Japan-China Joint Seminar on Atomic and Molecular Processes in Plasma was held on October 26 - 31, 2009 in Xi'an, China. The total number of the officially registered participants was 54, in which 18 from Japan, 35 from China, and 1 from USA. And this seminar is an extension of the last two seminars that were held on March 6 - 11, 2004 in Lanzhou, China, and on October 6 - 12, 2007 in Dunhuang, China. In the nuclear fusion plasma, there are quite a variety of atomic processes such as ionization, excitation, radiative recombination, non-radiative recombination (di-electronic recombination, collisional electron transfer), cascade radiation, and cascade Auger decay over the wide range of plasma temperature. The knowledge of those processes is indispensable for the evaluation and improvement of the plasma properties. Because of the diversity of the subject, it is desirable to investigate them by international collaboration groups. The present seminar may contribute to realize the above stated aim; especially it has given an opportunity for the collaborative workers to illustrate their achievements. This seminar summarizes the collaborative researches for the last decade and propose the issues for the future prospect. The 30 of the presented papers are indexed individually. (J.P.N.)

A wiggler magnet for FEL low voltage operation

Energy Technology Data Exchange (ETDEWEB)

Al-Shamma`a, A.; Stuart, R.A.; Lucas, J.

1995-12-31

In low voltage FELs (ie, 200kV), operation is necessarily in the microwave frequency range for wiggler periods of the order of cms., so that a waveguide system is mandatory. Also, because of the relatively low velocity of the electron beam, the wiggle amplitude of the electron beam can be much larger than is normal for highly relativistic FELs. Both these factors mean that the electron trajectory must be carefully controlled to avoid beam collision with the waveguide walls. A wiggler system with half poles at entrance and exit is not an acceptable solution because of the offset is gives rise to the electron trajectory. Consequently, we have designed and constructed a wiggler magnet with exponential entrance and exit tapers for a minimal deflection and displacement of the electron beam. Simulations and experimental measurements showed that an on axis trajectory is easily obtainable.

65NM sub-threshold 11T-SRAM for ultra low voltage applications

DEFF Research Database (Denmark)

Moradi, Farshad; Wisland, Dag T.; Aunet, Snorre

In this paper a new ultra low power SRAM cell is proposed. In the proposed SRAM topology, additional circuitry has been added to a standard 6T-SRAM cell to improve the static noise margin (SNM) and the performance. Foundry models for a 65 nm standard CMOS process were used for obtaining reliable...... simulated results. The circuit was simulated for supply voltages from 0.2 V to 0.35 V verifying the robustness of the proposed circuit for different supply voltages. The simulations show a significant improvement in SNM and a 4X improvement in read speed still maintaining a satisfactory write noise margin...

Electrical and optical investigations on the low voltage vacuum arc

International Nuclear Information System (INIS)

Braic, M.; Braic, V.; Pavelescu, G.; Balaceanu, M.; Pavelescu, D.; Dumitrescu, G.; Gherendi, F.

2002-01-01

Preliminary investigations of a low voltage circuit breaker, adapted from a real industrial device, were carried out by electrical and optical methods. Electrical, parameters were measured in the high current arc period and in zero current moment (C.Z) and corroborated with the arc plasma spectroscopic investigations. For the first time in vacuum arc diagnostics, the paper presents results based on single shot time resolved emission spectroscopy around C.Z. The short-circuit current was produced in a special high power installation in order to reproduce exactly the short-circuit regimes developing in low voltage distribution networks. A stainless steel vacuum chamber with classical Cu-Cr electrodes was used. Tests were performed for different current values in the range 3 - 20 kA rms , the voltages being varied between 200 and 1000 V ac . Interruption processes in the different arc regimes (from the diffuse arc mode to the constricted column mode) were analyzed. The success of the arc interruption was analyzed in terms of electric arc energy achieved in the first current halfperiod. The results obtained were corroborated with arc plasma spectroscopic investigations. The emission spectroscopy setup, using an Acton spectrograph and an intensified CCD camera, allowed the spatial and time-resolved investigation of spectra emitted by the vacuum arc plasma. The first truly time-resolved spectroscopic measurements on a single half-period was proven to be a good method to investigate the vacuum arc. Using single shot time resolved spectroscopy around zero current on partial unsuccessful interruption we concluded that the Cu ions, more that Cr ions were responsible for the arc reignition. The financial support for this work comes from NATO-STI SfP /974083 and CORINT-Romania projects. (authors)

A full on-chip CMOS low-dropout voltage regulator with VCCS compensation

Energy Technology Data Exchange (ETDEWEB)

Gao Leisheng; Zhou Yumei; Wu Bin; Jiang Jianhua, E-mail: gaoleisheng@ime.ac.c [Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029 (China)

2010-08-15

A full on-chip CMOS low-dropout (LDO) voltage regulator with high PSR is presented. Instead of relying on the zero generated by the load capacitor and its equivalent series resistance, the proposed LDO generates a zero by voltage-controlled current sources for stability. The compensating capacitor for the proposed scheme is only 0.18 pF, which is much smaller than the capacitor of the conventional compensation scheme. The full on-chip LDO was fabricated in commercial 0.35 {mu}m CMOS technology. The active chip area of the LDO (including the bandgap voltage reference) is 400 x 270 {mu}m{sup 2}. Experimental results show that the PSR of the LDO is -58.7 dB at a frequency of 10 Hz and -20 dB at a frequency of 1 MHz. The proposed LDO is capable of sourcing an output current up to 50 mA. (semiconductor integrated circuits)

Bucharest PhD Training School : Modern Aspects of Quantum Field Theory and Applications

CERN Document Server

2015-01-01

Bucharest 2015 – Modern Aspects of Quantum Field Theory is part of the CERN – SEENET-MTP PhD Training Program, which consists of a number of seminars in theoretical high energy Physics. This is the second seminar organized by this Program. Here are some photos from this event held in Bucharest between 8-14 November 2015. The previous seminar was organized in Belgrade, under the name Belgrade 2015 - Supergravity.

International school-seminar on heavy ion physics

International Nuclear Information System (INIS)

Oganesyan, Yu.Ts.

1990-01-01

The reports of the International school-seminar on heavy ion physics are presented. Scientific program of the school-seminar covers a wide spectrum of the today trends of investigations conducted using heavy ion beams within the energy range from several MeV/nucleon up to several GeV/nucleon

Low voltage electroosmotic pump for high density integration into microfabricated fluidic systems

NARCIS (Netherlands)

Heuck, F.C.A.; Staufer, U.

2011-01-01

A low voltage electroosmotic (eo) pump suitable for high density integration into microfabricated fluidic systems has been developed. The high density integration of the eo pump required a small footprint as well as a specific on-chip design to ventilate the electrolyzed gases emerging at the

Report for fiscal 2000 on joint seminar for coal engineer training project; 2000 nendo sekitan gijutsusha yosei jigyo godo semina hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-09-01

This paper summarizes the contents of the joint seminar for coal engineer training project in fiscal 2000, which has been held in Tokyo on September 25, 2000. The lectures included 'Coal Resources in Gunnedah Basin - Future Coal Supply Potential and Geophysical Exploration' by Ms. Julie Ann Moloney, senior geographical engineer at NSW Department of Mineral Resources, Australia, 'Human Resources Development for Coal Mining in Indonesia' by Mr. Bangun Usman Harahap at the Ministry of Mines and Energy in Indonesia, 'Queensland Rail, a strategic partner - linking Coal Producers to World Markets' by Mr. John Stuart Burrows at Coal Queensland Rail, Australia, and 'The export coal mines of western Canada - A review' by Mr. Ron Smyth, director BC Geological Survey Branch, Ministry of Energy and Mines, British Columbia, Canada. Questions and answers were exchanged actively for these lectures. (NEDO)

Asymmetrical Grid Fault Ride-Through Strategy of Three-phase Grid-connected Inverter Considering Network Impedance Impact in Low Voltage Grid

DEFF Research Database (Denmark)

Guo, Xiaoqiang; Zhang, Xue; Wang, Baocheng

2014-01-01

This letter presents a new control strategy of threephase grid-connected inverter for the positive sequence voltage recovery and negative sequence voltage reduction under asymmetrical grid faults. Unlike the conventional control strategy based on an assumption that the network impedance is mainly...... of the proposed solution for the flexible voltage support in a low-voltage grid, where thenetwork impedance is mainly resistive.......This letter presents a new control strategy of threephase grid-connected inverter for the positive sequence voltage recovery and negative sequence voltage reduction under asymmetrical grid faults. Unlike the conventional control strategy based on an assumption that the network impedance is mainly...... inductive, the proposed control strategy is more flexible and effective by considering the network impedance impact, which is of great importance for the high penetration of grid-connected renewable energy systems into low-voltage grids. The experimental tests are carried out to validate the effectiveness...

Low-Cost Open-Source Voltage and Current Monitor for Gas Metal Arc Weld 3D Printing

Directory of Open Access Journals (Sweden)

A. Pinar

2015-01-01

Full Text Available Arduino open-source microcontrollers are well known in sensor applications for scientific equipment and for controlling RepRap 3D printers. Recently low-cost open-source gas metal arc weld (GMAW RepRap 3D printers have been developed. The entry-level welders used have minimal controls and therefore lack any real-time measurement of welder voltage or current. The preliminary work on process optimization of GMAW 3D printers requires a low-cost sensor and data logger system to measure welder current and voltage. This paper reports on the development of a low-cost open-source power measurement sensor system based on Arduino architecture. The sensor system was designed, built, and tested with two entry-level MIG welders. The full bill of materials and open source designs are provided. Voltage and current were measured while making stepwise adjustments to the manual voltage setting on the welder. Three conditions were tested while welding with steel and aluminum wire on steel substrates to assess the role of electrode material, shield gas, and welding velocity. The results showed that the open source sensor circuit performed as designed and could be constructed for <$100 in components representing a significant potential value through lateral scaling and replication in the 3D printing community.

Low Voltage Ride-Through of Two-Stage Grid-Connected Photovoltaic Systems Through the Inherent Linear Power-Voltage Characteristic

DEFF Research Database (Denmark)

Yang, Yongheng; Sangwongwanich, Ariya; Liu, Hongpeng

2017-01-01

In this paper, a cost-effective control scheme for two-stage grid-connected PhotoVoltaic (PV) systems in Low Voltage Ride-Through (LVRT) operation is proposed. In the case of LVRT, the active power injection by PV panels should be limited to prevent from inverter over-current and also energy...... aggregation at the dc-link, which will challenge the dc-link capacitor lifetime if remains uncontrolled. At the same time, reactive currents should be injected upon any demand imposed by the system operators. In the proposed scheme, the two objectives can be feasibly achieved. The active power is regulated...... point tracking controller without significant hardware or software modifications. In this way, the PV system will not operate at the maximum power point, whereas the inverter will not face any over-current challenge but can provide reactive power support in response to the grid voltage fault...

Joint project to implement a training course/seminar for high-level decision making officals on nuclear policy between Korea and IAEA

International Nuclear Information System (INIS)

Lee, E. J.; Suh, S. H.; Kim, S. H. and others

2001-09-01

Through this project, the KAERI has published a english text book titled 'Nuclear Power project: Policy and Korean Experience' with the cooperation with the Agency. Korean experts, who have more than 30 years experiences in nuclear policy and nuclear power project management, involved to prepare the contents. Experts, who are working for Department of Nuclear Energy and Department of Technical Cooperation in the Agency, reviewed the contents. The KAERI has provided a training course/seminar for a high-level delegation of nuclear policy decision makers, which is consisted of 3 deputy ministers and 3 general directors in Viet Nam Communist Party, Assembly, Government Departments, upon the agreement between Vietnam Atomic Energy Commission (VAEC) and MOST at Hanoi in November 2000. The KAERI decided to provide the IAEA regional training course for middle level managers of nuclear policy and project management in RCA member states in November 2001 and 2002 under the cooperation with the Agency and the Korea International Cooperation Agency (KOICA). The training course curricula, a english text book will be utilized as basic technical materials to promote the national nuclear cooperation program with the developing countries, that are considering to introduce the first or a new nuclear power plant, such as China, Indonesia, Bangladesh, Morocco, Egypt, Ukraine, etc. Through the project, the bilateral nuclear cooperation between Viet Nam and Korea in the field of nuclear manpower development has improved practically. The KAERI has decided to provide on-the job-training program for Vietnamese experts in the field of nuclear policy, safety analysis, thermal-hydraulic analysis, etc under the 2000 KISTEP Scientist Exchange Program

Joint project to implement a training course/seminar for high-level decision making officals on nuclear policy between Korea and IAEA

Energy Technology Data Exchange (ETDEWEB)

Lee, E. J.; Suh, S. H.; Kim, S. H. and others

2001-09-01

Through this project, the KAERI has published a english text book titled 'Nuclear Power project: Policy and Korean Experience' with the cooperation with the Agency. Korean experts, who have more than 30 years experiences in nuclear policy and nuclear power project management, involved to prepare the contents. Experts, who are working for Department of Nuclear Energy and Department of Technical Cooperation in the Agency, reviewed the contents. The KAERI has provided a training course/seminar for a high-level delegation of nuclear policy decision makers, which is consisted of 3 deputy ministers and 3 general directors in Viet Nam Communist Party, Assembly, Government Departments, upon the agreement between Vietnam Atomic Energy Commission (VAEC) and MOST at Hanoi in November 2000. The KAERI decided to provide the IAEA regional training course for middle level managers of nuclear policy and project management in RCA member states in November 2001 and 2002 under the cooperation with the Agency and the Korea International Cooperation Agency (KOICA). The training course curricula, a english text book will be utilized as basic technical materials to promote the national nuclear cooperation program with the developing countries, that are considering to introduce the first or a new nuclear power plant, such as China, Indonesia, Bangladesh, Morocco, Egypt, Ukraine, etc. Through the project, the bilateral nuclear cooperation between Viet Nam and Korea in the field of nuclear manpower development has improved practically. The KAERI has decided to provide on-the job-training program for Vietnamese experts in the field of nuclear policy, safety analysis, thermal-hydraulic analysis, etc under the 2000 KISTEP Scientist Exchange Program.

Newton Output Blocking Force under Low-Voltage Stimulation for Carbon Nanotube-Electroactive Polymer Composite Artificial Muscles.

Science.gov (United States)

Chen, I-Wen Peter; Yang, Ming-Chia; Yang, Chia-Hui; Zhong, Dai-Xuan; Hsu, Ming-Chun; Chen, YiWen

2017-02-15

This is a study on the development of carbon nanotube-based composite actuators using a new ionic liquid-doped electroactive ionic polymer. For scalable production purposes, a simple hot-pressing method was used. Carbon nanotube/ionic liquid-Nafion/carbon nanotube composite films were fabricated that exhibited a large output blocking force and a stable cycling life with low alternating voltage stimuli in air. Of particular interest and importance, a blocking force of 1.5 N was achieved at an applied voltage of 6 V. Operational durability was confirmed by testing in air for over 30 000 cycles (or 43 h). The superior actuation performance of the carbon nanotube/ionic liquid-Nafion/carbon nanotube composite, coupled with easy manufacturability, low driving voltage, and reliable operation, promises great potential for artificial muscle and biomimetic applications.

2015 Cross-Domain Deterrence Seminar Bibliography

Energy Technology Data Exchange (ETDEWEB)

Juarez, Anthony [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2016-02-04

In November 2015, the Center for Global Security Research, NSO, and Global Security program jointly sponsored a seminar investigating questions related to cross-domain deterrence at Lawrence Livermore National Laboratory. At the seminar, experts were asked to moderate discussion based on the four topics below. For each of these topics, we have compiled a short list of literature that will help analysts develop a baseline understanding of the issue.

Proceedings on the seminar on small hydroelectric installations: Practice report and current development; Beitraege zum Seminar Kleinwasserkraft: Praxis und aktuelle Entwicklung

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-12-31

This seminar on small hydroelectric installations informs on aspects of construction and administrative aspects. But above all, questions of machinery are dealt with. The book gives an overview of turbine types, topical recent developments in the sector of small hydroelectric power stations, and modern opportunities for fast and inexpensive design of power station components. Beyond the discussion of technical issues, the seminar wants to further contacts between science, turbine manufacturers, consultants and plant operators. (orig.) [Deutsch] Das Seminar Kleinwasserkraft gibt eine Uebersicht ueber bauliche Gestaltung und behoerdliche Aspekte. Vorallem behandelt es aber maschinenbauliche Problemstellungen. Es zeigt einen Ueberblick ueber Turbinentypen, aktuelle Neuentwicklungen im Kleinwassersektor, sowie moderne Moeglichkeiten zum schnellen und preiswerten Design von Kraftwerkskomponenten. Neben dem technischen Teil dient das Seminar auch der Foerderung des Kontakts zwischen Wissenschaft, Turbinenherstellern, Consultants und Anlagenbetreibern. (orig.)

Real time diagnostic for operation at a CW low voltage FEL

Energy Technology Data Exchange (ETDEWEB)

Balfour, C.; Shaw, A.; Mayhew, S.E. [and others

1995-12-31

At Liverpool University, a system for single user control of an FEL has been designed to satisfy the low voltage FEL (ie 200kV) operational requirements. This system incorporates many aspects of computer automation for beam diagnostics, radiation detection and vacuum system management. In this paper the results of the development of safety critical control systems critical control systems are reported.

2015 Cross-Domain Deterrence Seminar Summary Report

Energy Technology Data Exchange (ETDEWEB)

Juarez, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2016-01-11

Lawrence Livermore National Laboratory (LLNL) hosted the 2nd Annual Cross-Domain Deterrence Seminar on November 17th, 2015 in Livermore, CA. The seminar was sponsored by LLNL’s Center for Global Security Research (CGSR), National Security Office (NSO), and Global Security program. This summary covers the seminar’s panels and subsequent discussions.

Polymer/metal oxide hybrid dielectrics for low voltage field-effect transistors with solution-processed, high-mobility semiconductors

Energy Technology Data Exchange (ETDEWEB)

Held, Martin; Schießl, Stefan P.; Gannott, Florentina [Department of Materials Science and Engineering, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen D-91058 (Germany); Institute for Physical Chemistry, Universität Heidelberg, Heidelberg D-69120 (Germany); Miehler, Dominik [Department of Materials Science and Engineering, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen D-91058 (Germany); Zaumseil, Jana, E-mail: zaumseil@uni-heidelberg.de [Institute for Physical Chemistry, Universität Heidelberg, Heidelberg D-69120 (Germany)

2015-08-24

Transistors for future flexible organic light-emitting diode (OLED) display backplanes should operate at low voltages and be able to sustain high currents over long times without degradation. Hence, high capacitance dielectrics with low surface trap densities are required that are compatible with solution-processable high-mobility semiconductors. Here, we combine poly(methyl methacrylate) (PMMA) and atomic layer deposition hafnium oxide (HfO{sub x}) into a bilayer hybrid dielectric for field-effect transistors with a donor-acceptor polymer (DPPT-TT) or single-walled carbon nanotubes (SWNTs) as the semiconductor and demonstrate substantially improved device performances for both. The ultra-thin PMMA layer ensures a low density of trap states at the semiconductor-dielectric interface while the metal oxide layer provides high capacitance, low gate leakage and superior barrier properties. Transistors with these thin (≤70 nm), high capacitance (100–300 nF/cm{sup 2}) hybrid dielectrics enable low operating voltages (<5 V), balanced charge carrier mobilities and low threshold voltages. Moreover, the hybrid layers substantially improve the bias stress stability of the transistors compared to those with pure PMMA and HfO{sub x} dielectrics.

Low-voltage organic field-effect transistors based on novel high-κ organometallic lanthanide complex for gate insulating materials

Energy Technology Data Exchange (ETDEWEB)

Liu, Qi; Li, Yi; Zhang, Yang; Song, You, E-mail: wangxzh@nju.edu.cn, E-mail: yli@nju.edu.cn, E-mail: yousong@nju.edu.cn; Wang, Xizhang, E-mail: wangxzh@nju.edu.cn, E-mail: yli@nju.edu.cn, E-mail: yousong@nju.edu.cn; Hu, Zheng [Key Laboratory of Mesoscopic Chemistry of MOE, Jiangsu Provincial Lab for Nanotechnology, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China. High-Tech Research Institute of Nanjing University (Suzhou), Suzhou 215123 (China); Sun, Huabin; Li, Yun, E-mail: wangxzh@nju.edu.cn, E-mail: yli@nju.edu.cn, E-mail: yousong@nju.edu.cn; Shi, Yi [School of Electronic Science and Engineering and Jiangsu Provincial Key Laboratory of Photonic and Electronic Materials, Nanjing University, Nanjing 210093 (China)

2014-08-15

A novel high-κ organometallic lanthanide complex, Eu(tta){sub 3}L (tta=2-thenoyltrifluoroacetonate, L = 4,5-pinene bipyridine), is used as gate insulating material to fabricate low-voltage pentacene field-effect transistors (FETs). The optimized gate insulator exhibits the excellent properties such as low leakage current density, low surface roughness, and high dielectric constant. When operated under a low voltage of −5 V, the pentacene FET devices show the attractive electrical performance, e.g. carrier mobility (μ{sub FET}) of 0.17 cm{sup 2} V{sup −1} s{sup −1}, threshold voltage (V{sub th}) of −0.9 V, on/off current ratio of 5 × 10{sup 3}, and subthreshold slope (SS) of 1.0 V dec{sup −1}, which is much better than that of devices obtained on conventional 300 nm SiO{sub 2} substrate (0.13 cm{sup 2} V{sup −1} s{sup −1}, −7.3 V and 3.1 V dec{sup −1} for μ{sub FET}, V{sub th} and SS value when operated at −30 V). These results indicate that this kind of high-κ organometallic lanthanide complex becomes a promising candidate as gate insulator for low-voltage organic FETs.

Radiological health training resources, 1975

International Nuclear Information System (INIS)

1975-01-01

The Division of Training and Medical Applications is the component of the Bureau of Radiological Health which has the responsibility for providing training assistance to the Nation's radiological health agencies. Recognizing that these agencies are establishing their own user and personnel training programs, the Division offers through the Training Resources Center a variety of educational materials which may be utilized for specific training purposes. This bulletin contains a list of educational materials, including publications, booklets, slides and transparencies, movies, video tapes, training guides, and training seminars for the education of x-ray technicians in radiation protection

Low Voltage Electrowetting on Ferroelectric PVDF-HFP Insulator with Highly Tunable Contact Angle Range.

Science.gov (United States)

Sawane, Yogesh B; Ogale, Satishchandra B; Banpurkar, Arun G

2016-09-14

We demonstrate a consistent electrowetting response on ferroelectric poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) insulator covered with a thin Teflon AF layer. This bilayer exhibits a factor of 3 enhancement in the contact angle modulation compared to that of conventional single-layered Teflon AF dielectric. On the basis of the proposed model the enhancement is attributed to the high value of effective dielectric constant (εeff ≈ 6) of the bilayer. Furthermore, the bilayer dielectric exhibits a hysteresis-free contact angle modulation over many AC voltage cycles. But the contact angle modulation for DC voltage shows a hysteresis because of the field-induced residual polarization in the ferroelectric layer. Finally, we show that a thin bilayer exhibits contact angle modulation of Δθ (U) ≈ 60° at merely 15 V amplitude of AC voltage indicating a potential dielectric for practical low voltage electrowetting applications. A proof of concept confirms electrowetting based rapid mixing of a fluorescent dye in aqueous glycerol solution for 15 V AC signal.

A STATCOM with Supercapacitors for Low-Voltage Ride-Through in Fixed-Speed Wind Turbines

Directory of Open Access Journals (Sweden)

Andrés Felipe Obando-Montaño

2014-09-01

Full Text Available Fixed-speed wind generator (FSWG technology has an important presence in countries where wind energy started to be developed more than a decade ago. This type of technology cannot be directly adapted to the grid codes, for example those requirements related to the immunity level under voltage dips. That behavior is typically referred as low-voltage ride through (LVRT, and it usually implies certain reactive and active power injection requirements, both during a voltage dip and during the voltage recovery. In this context, a review is presented of the LVRT exigencies present in some of the countries with the most advanced grid codes (Denmark, Germany, Spain and the United Kingdom. In this paper, the capabilities of STATCOM-based devices for fulfilling the LVRT requirements in FSWGs are analyzed. For this purpose, two technologies are considered: a STATCOM with a supercapacitor, which improves its energy storage features; and a STATCOM with a supercapacitor and a DC-DC converter, to achieve higher discharge levels.

International seminar on the safety research needs for Russian-designed reactors: material presented at the international seminar 1997

International Nuclear Information System (INIS)

1997-01-01

This seminar on international, national and bilateral cooperation programmes on the safety research needs for Russian-designed reactors was held in Tokyo, Japan (1997) and hosted by the OECD Nuclear Energy Agency and the Science and Technology Agency (STA) of Japan. More than 70 participants attended the seminar. Represented were experts from OECD/NEA member countries and Russia, the International Atomic Energy Agency (IAEA), the ISTC, the INSC and the Russian INSC. Eighteen papers were presented in five sessions. The seminar was structured around four main areas of cooperation: cooperative programmes of the OECD/NEA, programmes of international organisations, bi-lateral programmes, and national programmes of OECD/NEA member countries having reactors of the VVER type. General conclusions, followed by specific technical conclusions are included

Integration of 100% Micro-Distributed Energy Resources in the Low Voltage Distribution Network

DEFF Research Database (Denmark)

You, Shi; Segerberg, Helena

2014-01-01

of heat pumps (HPs) and plug-in electric vehicles (PEVs) at 100% penetration level on a representative urban residential low voltage (LV) distribution network of Denmark are investigated by performing a steady-state load flow analysis through an integrated simulation setup. Three DERs integration...... oriented integration strategies, having 100% integration of DER in the provided LV network is feasible.......The existing electricity infrastructure may to a great extent limit a high penetration of the micro-sized Distributed Energy Resources (DERs), due to the physical bottlenecks, e.g. thermal capacitates of cables, transformers and the voltage limitations. In this study, the integration impacts...

Mini Seminar on Form Filling Ability of Self-Compacting Concrete

DEFF Research Database (Denmark)

Thrane, Lars Nyholm

2005-01-01

The Nordic mini-seminar “Form Filling Ability of Self-Compacting Concrete” took place on 3-4 November 2003 at the Danish Technological Institute in Taastrup, Denmark. The mini-seminar gathered 12 participants from Finland, Sweden, Norway and Denmark. The objective was to present and discuss recent...... developments of Self-Compacting Concrete in the Nordic countries. In general, the seminar included results and observations on the effect of fresh concrete behaviour, casting technique, and organisation on site on the filling ability, passing ability, and surface quality. The seminar had participants from...

Control of a battery energy storage system connected to a low voltage grid

NARCIS (Netherlands)

van Dun, J.J.C.M.; de Groot, Robert; Morren, Johan; Slootweg, Han

2015-01-01

This paper describes the development of a control algorithm for a battery energy storage system, which is connected to a residential low voltage grid. By predicting future load demand and photovoltaic production within the neighbourhood concerned, flattening of the aggregated neighbourhood

Phase-wise enhanced voltage support from electric vehicles in a Danish low-voltage distribution grid

DEFF Research Database (Denmark)

Knezovic, Katarina; Marinelli, Mattia

2016-01-01

High deployment of electric vehicles (EVs) imposes great challenges for the distribution grids, especially in unbalanced systems with notable voltage variations which detrimentally affect security of supply. On the other hand, with development of Vehicle-to-Grid technology, EVs may be able...... to provide numerous services for grid support, e.g., voltage control. Implemented electronic equipment will allow them to exchange reactive power for autonomous voltage support without communicating with the distribution system operator or influencing the available active power for primary transportation...

A 32 kb 9T near-threshold SRAM with enhanced read ability at ultra-low voltage operation

Science.gov (United States)

Kim, Tony Tae-Hyoung; Lee, Zhao Chuan; Do, Anh Tuan

2018-01-01

Ultra-low voltage SRAMs are highly sought-after in energy-limited systems such as battery-powered and self-harvested SoCs. However, ultra-low voltage operation diminishes SRAM read bitline (RBL) sensing margin significantly. This paper tackles this issue by presenting a novel 9T cell with data-independent RBL leakage in combination with an RBL boosting technique for enhancing the sensing margin. The proposed technique automatically tracks process, temperature and voltage (PVT) variations for robust sensing margin enhancement. A test chip fabricated in 65 nm CMOS technology shows that the proposed scheme significantly enlarges the sensing margin compared to the conventional bitline sensing scheme. It also achieves the minimum operating voltage of 0.18 V and the minimum energy consumption of 0.92 J/access at 0.4 V. He received 2016 International Low Power Design Contest Award from ISLPED, a best paper award at 2014 and 2011 ISOCC, 2008 AMD/CICC Student Scholarship Award, 2008 Departmental Research Fellowship from Univ. of Minnesota, 2008 DAC/ISSCC Student Design Contest Award, 2008, 2001, and 1999 Samsung Humantec Thesis Award and, 2005 ETRI Journal Paper of the Year Award. He is an author/co-author of +100 journal and conference papers and has 17 US and Korean patents registered. His current research interests include low power and high performance digital, mixed- mode, and memory circuit design, ultra-low voltage circuits and systems design, variation and aging tolerant circuits and systems, and circuit techniques for 3D ICs. He serves as an associate editor of IEEE Transactions on VLSI Systems. He is an IEEE senior member and the Chair of IEEE Solid-State Circuits Society Singapore Chapter. He has served numerous conferences as a committee member.

Proceedings of JSPS-CAS core university program seminar on target materials

International Nuclear Information System (INIS)

Gu, Z.Z.; Norimatsu, T.

2008-02-01

China-Japan Bilateral Collaboration on the Study of Ultrahigh Density Plasma has been established since 2001 and its second phase is conducting from 2006. Target materials are key issue of the Study of Ultrahigh Density Plasma, and the second of target fabrication was opened at the 2005 Workshop on Ultrahigh Density Plasma Production, Application and theory for Laser Fusion at Nine Village Valley, Sichuan. It achieved great successes in high-level academic exchange and efficient presentation of state-of-the-art development in this research field. However, in order to attract greater attention and participation of more scientists in these fields, the organizing committee decided to further specify and enlarge the scale of the workshop to be China-Japan Bilateral Seminar on Target Materials 2007 in Huang Shan in southern Anhui Province of east China. The seminar had more than 20 participants from 7 universities and 3 institutes in Japan and China. They exchanged state-of-the-art development in nanomaterials, capsule fabrication and low density materials toward target of high power laser. This issue is the collection of the paper presented at the seminar. The 17 of the presented papers are indexed individually. (J.P.N.)

JSPS-CAS core university program seminar. Proceedings of Japan-China joint seminar on atomic and molecular processes in plasma

International Nuclear Information System (INIS)

Koike, Fumihiro; Dong Chenzhong

2008-03-01

As one of the activities of JSPS-CAS Core University Program, Japan-China Joint Seminar on Atomic and Molecular Processes in Plasma was held on October 8 - 12, 2007 in Dunhuang, China. The total number of the officially registered participants was 41, in which 12 from Japan, 25 from China, and 4 from EU. And this seminar is an extension of the last seminar that was held on March 6 - 11, 2004 in Lanzhou, China. In the nuclear fusion plasma, there are quite a variety of atomic processes such as ionization, excitation, radiative recombination, non-radiative recombination (di-electronic recombination, collisional electron transfer), cascade radiation, and cascade Auger decay over the wide range of plasma temperature. The knowledge of such processes is indispensable for the evaluation and improvement of the plasma properties, which is desirable to be investigated by international collaboration groups. The present seminar constitutes one of such activities to realize the above stated aim; especially it has given an opportunity for the collaborative workers to illustrate their achievements. The 32 of the presented papers are indexed individually. (J.P.N.)

Ge/graded-SiGe multiplication layers for low-voltage and low-noise Ge avalanche photodiodes on Si

Science.gov (United States)

Miyasaka, Yuji; Hiraki, Tatsurou; Okazaki, Kota; Takeda, Kotaro; Tsuchizawa, Tai; Yamada, Koji; Wada, Kazumi; Ishikawa, Yasuhiko

2016-04-01

A new structure is examined for low-voltage and low-noise Ge-based avalanche photodiodes (APDs) on Si, where a Ge/graded-SiGe heterostructure is used as the multiplication layer of a separate-absorption-carrier-multiplication structure. The Ge/SiGe heterojunction multiplication layer is theoretically shown to be useful for preferentially enhancing impact ionization for photogenerated holes injected from the Ge optical-absorption layer via the graded SiGe, reflecting the valence band discontinuity at the Ge/SiGe interface. This property is effective not only for the reduction of operation voltage/electric field strength in Ge-based APDs but also for the reduction of excess noise resulting from the ratio of the ionization coefficients between electrons and holes being far from unity. Such Ge/graded-SiGe heterostructures are successfully fabricated by ultrahigh-vacuum chemical vapor deposition. Preliminary pin diodes having a Ge/graded-SiGe multiplication layer act reasonably as photodetectors, showing a multiplication gain larger than those for diodes without the Ge/SiGe heterojunction.

Using a first-year seminar to introduce nursing.

Science.gov (United States)

Mennenga, Heidi A; Tschetter, Lois

2013-01-01

First-year seminar courses designed to aid the transition of freshmen students to the collegiate experience are commonplace requirements at many 4-year institutions. The authors describe the development, implementation, and outcomes of a first-year seminar course with introductory nursing content.

Cooperative control of VSC-HVDC connected offshore wind farm with Low-Voltage Ride-Through capability

DEFF Research Database (Denmark)

Liu, Yan; Wang, Xiongfei; Chen, Zhe

2012-01-01

The Low-Voltage Ride-Through (LVRT) has become an important grid requirement for offshore wind farms connecting with Voltage Source Converter based High Voltage Direct Current (VSC-HVDC) links. In this paper, a cooperative control strategy with LVRT ability is proposed for a VSC-HVDC connected...... variable speed Squirrel-Cage Induction Generator (SCIG) wind farm. The approach employs a DC-link voltage versus offshore AC-bus frequency droop control on the offshore converter of VSC-HVDC link. Thus, the back-to-back converters of SCIG wind turbines can adjust the generated active power based on the AC......-bus frequency deviations, so that a fast power reduction on the wind farm side can be achieved. The EMTDC/PSCAD simulations are performed on a 300 MW offshore variable speed SCIG wind farm. Simulation results confirm the effectiveness of the proposed control method....

Nordic seminar on energy taxes

International Nuclear Information System (INIS)

1991-01-01

Taxes on energy contribute considerably to a State's income, it is stated. This form of taxation also influences the consumer prices of energy products significantly. Taxation is an important means of political control within the energy sector, it is also a powerful means of controlling a country's environmental policy. The seminar's aim was to study the theoretical background for energy taxation and to provide information on how the standard system for taxation has changed in the various Nordic countries, and the need for a renewal of energy taxation. Seven papers presented at the seminar are presented. (AB)

Uranium industry seminar: proceedings

International Nuclear Information System (INIS)

1981-01-01

The eleventh annual Uranium Industry Seminar, sponsored by the Grand Junction Area Office of the US Department of Energy (DOE), was held in Grand Junction, Colorado, on October 21 and 22, 1981. There were 491 registered attendees as compared to 700 attending the previous year. The attendees were largely from uranium and other energy resource companies, electric utility firms, energy consultants and service companies, and governmental agencies. In addition, there were representatives present from Indian tribes, universities, the media, DOE laboratories, and foreign countries and organizations. Papers presented at the seminar dealt with uranium policies, exploration, resources, supply, enrichment, and market conditions. There also were papers on the National Uranium Resource Evaluation Program and international activities. Thirteen papers included in this report have been abstracted and indexed

Solution Processable Electrochemiluminescent Ion Gels for Flexible, Low Voltage, Emissive Displays on Plastic

Science.gov (United States)

Moon, Hong Chul; Lodge, Timothy P.; Frisbie, C. Daniel

2014-03-01

We have expanded the functionality of ion gels and successfully demonstrated low voltage, flexible electrochemiluminescent (ECL) devices using patterned ECL gels. An ECL device composed of only an emissive gel and two electrodes was fabricated on an ITO-coated substrate by solution casting the ECL gel and brush-painting the top silver electrode. The device turned on at an AC voltage as low as 2.6 V (-1.3 V ~ +1.3 V) and showed a relatively rapid response (sub-ms). Also, we varied the mechanical properties of the ECL gel simply by substituting polystyrene-block-poly(methyl methacrylate)-block-polystyrene (SMS) with commercially available poly(vinylidene fluoride-co-hexafluoropropylene) (P(VDF-co-HFP)), enabling the fabrication of flexible ECL devices on any target substrate by the ``cut-and-stick'' strategy. This simple, rubbery ECL gel should be attractive for flexible electronics applications such as displays on packaging.

NKS/SOS-1 seminar on safety analysis

Energy Technology Data Exchange (ETDEWEB)

Lauridsen, K. [Risoe National Lab., Roskilde (Denmark); Anderson, K. [Karinta-Konsult (Sweden); Pulkkinen, U. [VTT Automation (Finland)

2001-05-01

The report describes presentations and discussions at a seminar held at Risoe on March 22-23, 2000. The title of the seminar was NKS/SOS-1 - Safety Analysis. It dealt with issues of relevance for the safety analysis for the entire nuclear safety field (notably reactors and nuclear waste repositories). Such issues were: objectives of safety analysis, risk criteria, decision analysis, expert judgement and risk communication. In addition, one talk dealt with criteria for chemical industries in Europe. The seminar clearly showed that the concept of risk is multidimensional, which makes clarity and transparency essential elements in risk communication, and that there are issues of common concern between different applications, such as how to deal with different kinds of uncertainty and expert judgement. (au)

Microelectrode-assisted low-voltage atmospheric pressure glow discharge in air

Science.gov (United States)

Liu, Wenzheng; Zhao, Shuai; Niu, Jiangqi; Chai, Maolin

2017-09-01

During the process of discharge, appropriately changing the paths corresponding to electric field lines and the field strength distribution along these paths, as well as increasing the number of initial electrons, can effectively enhance the uniformity of discharge and inhibit the formation of filamentary discharge. A method is proposed that uses a microelectrode to initiate the macroscopic discharge phenomenon. An asymmetric structure was designed comprising a single electrode of carbon fiber; this electrode structure is of helical-contact type. Benefitting from the special electric field distribution and the microdischarge process, a three-dimensional atmospheric pressure glow discharge was achieved in air, characterized by low discharge voltage, low energy consumption, good diffusion performance, and less ozone generation. The plasma studied is uniform and stable with good diffusion characteristics and low levels of contaminants and hence has potential applications in the field of air purification.

Uranium industry seminar

International Nuclear Information System (INIS)

1980-01-01

The tenth annual Uranium Industry Seminar, sponsored by the US Department of Energy's (DOE) Grand Junction Office, was held in Grand Junction, Colorado, on October 22 and 23, 1980. There were 700 registered attendees as compared to 833 attending the previous year. The attendees were drawn largely from uranium and other energy resource companies, electric utility firms, energy consultants and service companies, and governmental agencies. In addition, there were representatives present from Indian tribes, universities, the media, DOE laboratories, and foreign countries and organizations. There were 14 papers presented at the seminar by speakers from the Department of Energy, US Geological Survey, and Bendix Field Engineering Corporation which is the on-site prime contractor for DOE's Grand Junction Office. The topics the papers dealt with were uranium policies, exploration, respources, supply, enrichment, and market conditions. There also were papers describing the National Uranium Resource Evaluation program and international activities. All 14 papers in this Proceedings have been abstracted and indexed

Low-tube-voltage (80 kVp) CT aortography using 320-row volume CT with adaptive iterative reconstruction: lower contrast medium and radiation dose

Energy Technology Data Exchange (ETDEWEB)

Chen, Chien-Ming; Chu, Sung-Yu; Hsu, Ming-Yi [Chang Gung University, Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital Linkou, College of Medicine, Taoyuan (China); Liao, Ying-Lan [National Tsing Hua University, Department of Biomedical Engineering and Environmental Sciences, Hsinchu (China); Tsai, Hui-Yu [Chang Gung University, Department of Medical Imaging and Radiological Sciences, College of Medicine, Taoyuan (China); Chang Gung University, Healthy Aging Research Center, Taoyuan (China); Chang Gung University, Department of Medical Imaging and Radiological Sciences, Taoyuan (China)

2014-02-15

To evaluate CT aortography at reduced tube voltage and contrast medium dose while maintaining image quality through iterative reconstruction (IR). The Institutional Review Board approved a prospective study of 48 patients who underwent follow-up CT aortography. We performed intra-individual comparisons of arterial phase images using 120 kVp (standard tube voltage) and 80 kVp (low tube voltage). Low-tube-voltage imaging was performed on a 320-detector CT with IR following injection of 40 ml of contrast medium. We assessed aortic attenuation, aortic attenuation gradient, image noise, contrast-to-noise ratio (CNR), volume CT dose index (CTDI{sub vol}), and figure of merit (FOM) of image noise and CNR. Two readers assessed images for diagnostic quality, image noise, and artefacts. The low-tube-voltage protocol showed 23-31 % higher mean aortic attenuation and image noise (both P < 0.01) than the standard-tube-voltage protocol, but no significant difference in the CNR and aortic attenuation gradients. The low-tube-voltage protocol showed a 48 % reduction in CTDI{sub vol} and an 80 % increase in FOM of CNR. Subjective diagnostic quality was similar for both protocols, but low-tube-voltage images showed greater image noise (P = 0.01). Application of IR to an 80-kVp CT aortography protocol allows radiation dose and contrast medium reduction without affecting image quality. (orig.)

Low-voltage organic thin film transistors (OTFTs) using crosslinked polyvinyl alcohol (PVA)/neodymium oxide (Nd2O3) bilayer gate dielectrics

Science.gov (United States)

Khound, Sagarika; Sarma, Ranjit

2018-01-01

We have reported here on the design, processing and dielectric properties of pentacene-based organic thin film transitors (OTFTs) with a bilayer gate dilectrics of crosslinked PVA/Nd2O3 which enables low-voltage organic thin film operations. The dielectric characteristics of PVA/Nd2O3 bilayer films are studied by capacitance-voltage ( C- V) and current-voltage ( I- V) curves in the metal-insulator-metal (MIM) structure. We have analysed the output electrical responses and transfer characteristics of the OTFT devices to determine their performance of OTFT parameters. The mobility of 0.94 cm2/Vs, the threshold voltage of - 2.8 V, the current on-off ratio of 6.2 × 105, the subthreshold slope of 0.61 V/decade are evaluated. Low leakage current of the device is observed from current density-electric field ( J- E) curve. The structure and the morphology of the device are studied using X-ray diffraction (XRD) and atomic force microscope (AFM), respectively. The study demonstrates an effective way to realize low-voltage, high-performance OTFTs at low cost.

Low driving voltage simplified tandem organic light-emitting devices by using exciplex-forming hosts

Science.gov (United States)

Zhou, Dong-Ying; Cui, Lin-Song; Zhang, Ying-Jie; Liao, Liang-Sheng; Aziz, Hany

2014-10-01

Tandem organic light-emitting devices (OLEDs), i.e., OLEDs containing multiple electroluminescence (EL) units that are vertically stacked, are attracting significant interest because of their ability to realize high current efficiency and long operational lifetime. However, stacking multiple EL units in tandem OLEDs increases driving voltage and complicates fabrication process relative to their standard single unit counterparts. In this paper, we demonstrate low driving voltage tandem OLEDs via utilizing exciplex-forming hosts in the EL units instead of conventional host materials. The use of exciplex-forming hosts reduces the charge injection barriers and the trapping of charges on guest molecules, resulting in the lower driving voltage. The use of exciplex-forming hosts also allows using fewer layers, hence simpler EL configuration which is beneficial for reducing the fabrication complexity of tandem OLEDs.

Forty years of training program in the JAERI

International Nuclear Information System (INIS)

1998-03-01

This report is to compile the past training program of researchers, engineers and regulatory members at the NuTEC (Nuclear Technology and Education Center) of Japan Atomic Energy Research Institute and the past basic seminars for the public, in addition to advice and perspective on the future program from relevant experts, in commemoration of the forty years of the NuTEC. It covers the past five years of educational courses and seminars in utilization of radioisotopes and nuclear energy for domestic and for international training provided at Tokyo and Tokai Education Centers and covers the activity of the Asia-Pacific nuclear technology transfer, including the activity of various committees and meetings. Especially, fifty six experts and authorities have contributed to the report with positive advice and perspective on the training program in the 21st century based on their reminiscences. (author)

History of the RSIC seminar-workshops

International Nuclear Information System (INIS)

Maskewitz, B.F.

1992-01-01

The RSIC concept of the open-quote seminar-workshop close-quote as a means to review the state-of-the-art of specific computing technology and to transmit a great deal of information to a large number of people in a short period of time evolved over a 30-year period. This paper presents the background leading to the development of the concept and details the history of the seminars and workshops organized by RSIC staff members through the years, 1965 - 1992

Protection of Low Voltage CIGRE distribution Network

DEFF Research Database (Denmark)

Mustafa, Ghullam; Bak-Jensen, Birgitte; Bak, Claus Leth

2013-01-01

High quality electricity services are the prime objectives in the modern power systems around the world. One of the main players to achieve this is protection of the system which needs to be fast, reliable and cost effective. The study about the protection of the Low Voltage (LV) CIGRE distribution...... grid and networks like this has been proposed in this paper. The main objective of this paper is to develop protection against short circuit faults which might appear any-where in the network. The protection of the power networks that comprises of renewable energy generation units is complicated...... because of the bidirectional flow of the current and is a challenge for the protection engineers. The selection of the protection devices in this paper is made to protect the network against faults in grid connected and island mode of operation. Ultra-fast fuses are proposed in order to protect...

Effects of a low-voltage static electric field on energy metabolism in astrocytes.

Science.gov (United States)

Huang, R; Peng, L; Hertz, L

1997-01-01

Mouse astrocytes (glial cells) in primary cultures were exposed to a low-voltage static DC electric field with no current flow and thus with no generation of magnetic fields. The electric field altered the rate of glycolysis, measured by 2-deoxyglucose accumulation. The magnitude and direction of this effect depended on the polarization of the field and the applied voltage. The maximum effect was an increase of approximately 30%, which occurred with field across the cells at an intensity that can be calculated to be 0.3 mV/cm or less. Reversal of the polarization converted the stimulation to a small but statistically significant inhibition.

Training model to institutionalize population education in the in-service education programme for elementary school teachers.

Science.gov (United States)

Dugenia, M E

1982-12-01

The goal of the Philippine Population Education Program (PEP) since its inception in 1972 is to institutionalize population education in the formal educational system. The PEP Training Section views institutionalization of population education in the inservice education program for elementary school teachers as part of the process of making it an integral part of that program. In practice elementary school teachers periodically attend training programs organized by division or district supervisors and school principals. This is the usual modality through which teachers are updated on or informed about new thrusts and recent developments in teaching content, strategies, and methodologies. In this context, the PEP Training Section convened a seminar workshop in December 1981 for 10 subject area supervisors from the 3 large geographic island groups of Luzon, Visayas, and Mindanao. They represented 10 school divisions and subject areas where population education is integrated. The specific objectives of the 5 day activity were to: discuss existing inservice training programs in the school divisions; prepare a training model incorporating population education in the overall division inservice training program; and develop a content chart or a listing of topical areas on population education for the training model. 1 of the outputs of the seminar workshop was a training model incorporating population education in the regular inservice training programs using 3 delivery schemes, i.e., seminar workship on the teaching of specific subject areas; district staff meeting and/or echo seminars organized by district supervisors following division seminars; and regular teachers' meeting at the school level organized by school principals. Another output was a content chart listing suggested topics in population education classified according to subject areas into which they will be incorporated. The semninar workshop concluded with a plan to try out the model using the identified

Scientists for non-proliferation of nuclear weapons. Transactions of international seminar

International Nuclear Information System (INIS)

1994-01-01

This publication presents the results of the Second International Seminar 'Scientists for Non-Proliferation of Nuclear Weapons'. The Seminar took place from 11 to 14 October 1994 in Nakhabino Country Club near Moscow. More than 60 specialists from Russia, USA, France, Belgium as well as IAEA and CEU took part in the seminar. Problems of cooperation in the field of nuclear materials accounting, control and safeguards, physical protection of nuclear materials, nuclear export regulations and disarmament control are discussed at the seminar

33. MPA seminar 2007. Proceedings; 33. MPA Seminar 2007. Vortraege

Energy Technology Data Exchange (ETDEWEB)

NONE

2007-07-01

In a single PDF file, the CD-ROM contains all papers presented at the 33. MPA Seminar in Stuttgart. Subjects: Life management of nuclear facilities: Materials, integrity analysis, fracture mechanics; Behaviour of welds; Material development and qualification for power plants with enhanced steam parameters; monitoring concepts (e.g. state monitoring of components, test concepts); Design of pipelines with flanged joints; Assembly and joining technology for flanged joints; Non-destructive testing in plant engineering; Materials for new nuclear reactors. Many of the papers are available as separate items in this database. [German] In einer einzigen PDF-Datei sind auf der CD-ROM alle Vortraege enthalten, die auf dem 33. MPA-Seminar in Stuttgart gehalten wurden. Die Themenschwerpunkte sind: Lebensdauermanagement kerntechnischer Anlagen - Werkstoffverhalten, Integritaetsanalyse, Bruchmechanik; Verhalten von Schweissverbindungen; Werkstoffentwicklung und -qualifizierung fuer Kraftwerke mit erhoehten Dampfparametern; Ueberwachungskonzepte (z.B. Zustandsueberwachung von Komponenten, Pruefkonzepte); Auslegung von Rohrleitungen mit Flanschverbindungen; Montage- und Dichtungstechnik fuer Flanschverbindungen; Zerstoerungsfreie Pruefung in der Anlagentechnik; Werkstoffe fuer neue Kernreaktoren. Ein grosser Teil der Vortraege wurde separat aufgenommen.

Evaluating online continuing medical education seminars: evidence for improving clinical practices.

Science.gov (United States)

Weston, Christine M; Sciamanna, Christopher N; Nash, David B

2008-01-01

The purpose of this study was to evaluate the potential for online continuing medical education (CME) seminars to improve quality of care. Primary care physicians (113) participated in a randomized controlled trial to evaluate an online CME series. Physicians were randomized to view either a seminar about type 2 diabetes or a seminar about systolic heart failure. Following the seminar, physicians were presented with 4 clinical vignettes and asked to describe what tests, treatments, counseling, or referrals they would recommend. Physicians who viewed the seminars were significantly more likely to recommend guideline-consistent care to patients in the vignettes. For example, physicians who viewed the diabetes seminar were significantly more likely to order an eye exam for diabetes patients (63%) compared with physicians in the control group (27%). For some guidelines there were no group differences. These results provide early evidence of the effectiveness of online CME programs to improve physician clinical practice.

Interpolating by a factor of 3 in low-voltage low-power ∑Δ DAC

DEFF Research Database (Denmark)

Pracný, Peter; Jørgensen, Ivan Harald Holger; Bruun, Erik

2014-01-01

This paper presents the power optimization of a sigma-delta (RD) modulator based digital-to-analog converter (DAC) for hearing aid audio back-end application. In a number of state-of-the-art publications the oversampling ratio (OSR) of the RD modulator is chosen as a factor of integer power of two...... by a factor of 3 are investigated. This new design freedom is used to lower the operating frequency of the whole back-end and save considerable amount of power. It is shown that the figure of- merit of such designs can be lower than designs using oversampling by a factor of integer powers of two. The same...... optimization approach can be used for other low voltage low power portable audio applications (mobile phones, notebook computers etc.)....

Input-current-shaper based on a modified SEPIC converter with low voltage stress

DEFF Research Database (Denmark)

Petersen, Lars

2001-01-01

The boost topology is often the designer's first choice when dealing with PFC front-ends. This topology is well documented in the literature and has obvious advantages like continuous input current and low voltage- and current-stress compared to other PFC topologies. The PFC SEPIC converter also...

Low-voltage analog front-end processor design for ISFET-based sensor and H+ sensing applications

Science.gov (United States)

Chung, Wen-Yaw; Yang, Chung-Huang; Peng, Kang-Chu; Yeh, M. H.

2003-04-01

This paper presents a modular-based low-voltage analog-front-end processor design in a 0.5mm double-poly double-metal CMOS technology for Ion Sensitive Field Effect Transistor (ISFET)-based sensor and H+ sensing applications. To meet the potentiometric response of the ISFET that is proportional to various H+ concentrations, the constant-voltage and constant current (CVCS) testing configuration has been used. Low-voltage design skills such as bulk-driven input pair, folded-cascode amplifier, bootstrap switch control circuits have been designed and integrated for 1.5V supply and nearly rail-to-rail analog to digital signal processing. Core modules consist of an 8-bit two-step analog-digital converter and bulk-driven pre-amplifiers have been developed in this research. The experimental results show that the proposed circuitry has an acceptable linearity to 0.1 pH-H+ sensing conversions with the buffer solution in the range of pH2 to pH12. The processor has a potential usage in battery-operated and portable healthcare devices and environmental monitoring applications.

YoungRad-seminar. Proceedings. Seminar for young scientists in the fields of radiophysics, radiochemistry, radioecology, radiation protection and related fields

International Nuclear Information System (INIS)

Straelberg, E.; Sidhu, R.; Petersen, R.; Salminen, S.

2007-09-01

To provide an inspiring working environment for young students and scientists, it is important that they at an early stage can take part in a network of scientists working in their fields of interest. However, within each of the five Nordic countries the network of people involved in the fields of radiophysics, radiochemistry, radioecology, radiation protection and other related fields is rather small. Educational networking is a key factor in keeping young researchers motivated to continue working within these fields, and to recruit new students. For that reason the first YoungRad-seminar was held in Helsinki 14-15 December 2006. 43 young participants including MSc and PhD students at universities, researchers at different institutes and personnel from Nordic authorities took part in the seminar. All Nordic countries except Iceland were represented. The seminar was divided into four sessions including oral and poster presentations. In addition two senior researchers were invited to speak about Nordic radioecology and NKS. This report contains the abstracts and presentations made at the seminar. (au)

YoungRad-seminar. Proceedings. Seminar for young scientists in the fields of radiophysics, radiochemistry, radioecology, radiation protection and related fields

Energy Technology Data Exchange (ETDEWEB)

Straelberg, E; Sidhu, R [Institute for Energy Technology (Norway); Petersen, R [Technological Univ. of Denmark (Denmark); Salminen, S [Univ. of Helsinki (Finland)

2007-09-15

To provide an inspiring working environment for young students and scientists, it is important that they at an early stage can take part in a network of scientists working in their fields of interest. However, within each of the five Nordic countries the network of people involved in the fields of radiophysics, radiochemistry, radioecology, radiation protection and other related fields is rather small. Educational networking is a key factor in keeping young researchers motivated to continue working within these fields, and to recruit new students. For that reason the first YoungRad-seminar was held in Helsinki 14-15 December 2006. 43 young participants including MSc and PhD students at universities, researchers at different institutes and personnel from Nordic authorities took part in the seminar. All Nordic countries except Iceland were represented. The seminar was divided into four sessions including oral and poster presentations. In addition two senior researchers were invited to speak about Nordic radioecology and NKS. This report contains the abstracts and presentations made at the seminar. (au)

4th ASEM Seminar on Knowledge Management to Enhance Nuclear Safety

International Nuclear Information System (INIS)

Castello, F.; Reyes, A. de los; Sobari, M. P. Mohd; Istiyanto, J. E.; Faross, P.; Delarosa, A.

2016-01-01

Full text: The 4th Asia-Europe Meeting (ASEM) Seminar on Nuclear Safety was convened in Madrid, Spain on 29th–30th October 2015, hosted by the Spanish Nuclear Safety Council. The seminar’s theme was “Knowledge management to enhance nuclear safety”, which aimed to continue discussing on nuclear safety to foster Asia-Europe capacity-building and cooperation in nuclear safety. The seminar was attended by representatives from national governments, nuclear regulators, energy companies, radiation protection and nuclear safety authorities, research institutes and universities. According to such model, proposed by the IAEA, the national capacity building requires an integrated approach based on four pillars: human resources development, education and training, knowledge management and knowledge networking. In this context, Nuclear Knowledge Management (KM) has become a high priority in many countries and international organizations and it has been taken into account to develop and implement specific strategies in ensuring safe and sustainable operation of nuclear facilities. At national level, a sustainable approach should include the necessary Nuclear Knowledge Management actions to ensure that every actor having a significant role in the national nuclear programmes infrastructure acquires, preserves and improves its corporate and individual knowledge. (author

Proceedings of the 1989 seminar on nuclear data

International Nuclear Information System (INIS)

Nakajima, Yutaka; Igashira, Masayuki

1990-02-01

The 1989 Seminar no Nuclear Data was held at Tokai Research Establishment of Japan Atomic Energy Research Institute, on November 16 and 17, 1989. This Seminar was organized by Japanese Nuclear Data Committee (JNDC) and Nuclear Data Center, JAERI. In an oral session, review and benchmark tests of JENDL-3 were presented, which were followed by lively discussion. Data need of other nuclear data than neutron induced reaction data were also presented. In addition, several topical talks were given. In a poster session, twenty papers on evaluation and measurement was presented and fruitful discussions were made. In this proceedings, thirty-four papers given in the seminar are compiled. (author)

Developments in the transport of radioactive waste. Proceedings of a seminar held in Vienna, 21-25 February 1994

International Nuclear Information System (INIS)

1995-06-01

This document is proceeding of the seminar on development in the transport of low and intermediate level radioactive wastes. The papers presented in this seminar covered the following areas: IAEA activities in radioactive waste transport; Member State experience and recommendations for international transport regulations; Member State experience with national transport regulations; waste transport and handling; waste generation volumes, characteristics, and disposal requirements; risk assessment; and transport and waste packages. Refs, figs and tabs

Developments in the transport of radioactive waste. Proceedings of a seminar held in Vienna, 21-25 February 1994

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-06-01

This document is proceeding of the seminar on development in the transport of low and intermediate level radioactive wastes. The papers presented in this seminar covered the following areas: IAEA activities in radioactive waste transport; Member State experience and recommendations for international transport regulations; Member State experience with national transport regulations; waste transport and handling; waste generation volumes, characteristics, and disposal requirements; risk assessment; and transport and waste packages. Refs, figs and tabs.

The methodological seminar “Psychological Safety in Transport”

Directory of Open Access Journals (Sweden)

Sviridenko I.N.

2018-03-01

Full Text Available This paper provides a short brief overview of the methodological seminar “Psychological Safety in Transport” organized in Yekaterinburg on the 17th November 2017. This seminar consisted of the plenary session and four workshops focused on analyzing most important issues of Human Factor of Road Safety.

Core strength training for patients with chronic low back pain.

Science.gov (United States)

Chang, Wen-Dien; Lin, Hung-Yu; Lai, Ping-Tung

2015-03-01

[Purpose] Through core strength training, patients with chronic low back pain can strengthen their deep trunk muscles. However, independent training remains challenging, despite the existence of numerous core strength training strategies. Currently, no standardized system has been established analyzing and comparing the results of core strength training and typical resistance training. Therefore, we conducted a systematic review of the results of previous studies to explore the effectiveness of various core strength training strategies for patients with chronic low back pain. [Methods] We searched for relevant studies using electronic databases. Subsequently, we evaluated their quality by analyzing the reported data. [Results] We compared four methods of evaluating core strength training: trunk balance, stabilization, segmental stabilization, and motor control exercises. According to the results of various scales and evaluation instruments, core strength training is more effective than typical resistance training for alleviating chronic low back pain. [Conclusion] All of the core strength training strategies examined in this study assist in the alleviation of chronic low back pain; however, we recommend focusing on training the deep trunk muscles to alleviate chronic low back pain.

Control of Grid Interactive PV Inverters for High Penetration in Low Voltage Distribution Networks

DEFF Research Database (Denmark)

Demirok, Erhan

Regarding of high density deployment of PV installations in electricity grids, new technical challenges such as voltage rise, thermal loading of network components, voltage unbalance, harmonic interaction and fault current contributions are being added to tasks list of distribution system operators...... of these inverters may depend on grid connection rules which are forced by DSOs. Minimum requirement expected from PV inverters is to transfer maximum power by taking direct current (DC) form from PV modules and release it into AC grid and also continuously keep the inverters synchronized to the grid even under...... for this problem but PV inverters connected to highly capacitive networks are able to employ extra current and voltage harmonics compensation to avoid triggering network resonances at low order frequencies. The barriers such as harmonics interaction, flicker, fault current contribution and dc current injections...

Automatic Power-Sharing Modification of P/V Droop Controllers in Low-Voltage Resistive Microgrids

DEFF Research Database (Denmark)

L. Vandoorn, Tine; D. M. De Kooning, Jeroen; Meersman, Bart

2012-01-01

Microgrids are receiving an increasing interest to integrate the growing share of distributed-generation (DG) units in the electrical network. For the islanded operation of themicrogrid, several control strategies for the primary control have been developed to ensure stable microgrid operation....... In low-voltage (LV) microgrids, active power/voltage ( P/V ) droop controllers are gaining attention as they take the resistive nature of the network lines and the lack of directly coupled rotating inertia into account. However, a problem often cited with these droop controllers is that the grid voltage...... is not a global parameter. This can influence the power sharing between different units. In this paper, it is investigated whether this is actually a disadvantage of the control strategy. It is shown that with / droop control, the DG units that are located electrically far from the load centers automatically...

PREFACE: Eurotherm Seminar 102: Thermal Management of Electronic Systems

Science.gov (United States)

Punch, J.; Walsh, E.

2014-07-01

About EUROTHERM The aim of the EUROTHERM Committee (www.eurothermcommittee.eu) is to promote and foster European cooperation in Thermal Sciences and Heat Transfer by gathering together scientists and engineers working in specialized areas. The Committee consists of members representing and appointed by national bodies in the EU countries. The current President of EUROTHERM is Professor Anton van Steenhoven from the University of Eindhoven (The Netherlands). The Committee organizes and coordinates European scientific events such as the EUROTHERM Seminars (about 4 per year) and the European Thermal Sciences Conference (every 4 years). About EUROTHERM Seminar 102 (www.eurothermseminar102.com) This seminar, part of the long-running series of European seminars on the thermal sciences, took place in June 2014 at the University of Limerick in Limerick, Ireland. The seminar addressed the topic of 'Thermal Management of Electronic Systems', a critical contemporary application area which represents a vibrant challenge for practitioners of the thermal sciences. We convey special thanks to the reviewers who have evaluated these papers. We also thank the scientific committee, consisting of internationally recognized experts. Their role has been to manage the evaluation of abstracts and the papers selection process as co-coordinators for specific topics. This seminar was hosted by the Stokes Institute at the University of Limerick. It could not have been organized without the efficient help of our administrators and technicians for IT support. This volume of Journal of Physics: Conference Series includes 27 articles presented at the seminar. Dr. Jeff Punch, Chair Stokes Institute, University of Limerick, Limerick, Ireland Email: jeff.punch@ul.ie Prof. Edmond Walsh, Co-Chair Associate Professor, Osney Laboratories, Department of Engineering Science, University of Oxford, UK Email: edmond.walsh@bnc.ox.ac.uk

Low voltage powering of on-detector electronics for HL-LHC experiments upgrades

CERN Document Server

Bobillier, Vincent; Vasey, Francois; Karmakar, Sabyasachi; Maity, Manas; Roy, Subhasish; Kundu, Tapas Kumar

2018-01-01

All LHC experiments will be upgraded during the next LHC long shutdowns (LS2 and LS3). The increase in resolution and luminosity and the use of more advanced CMOS technology nodes typically implies higher current consumption of the on-detector electronics. In this context, and in view of limiting the cable voltage drop, point-of-load DC-DC converters will be used on detector. This will have a direct impact on the existing powering scheme, implying new AC-DC and/or DC-DC stages as well as changes in the power cabling infrastructure. This paper presents the first results obtained while evaluating different LV powering schemes and distribution layouts for HL-LHC trackers. The precise low voltage power source requirements are being assessed and understood using the CMS tracker upgrade as a use-case.

A transient-enhanced NMOS low dropout voltage regulator with parallel feedback compensation

International Nuclear Information System (INIS)

Wang Han; Tan Lin

2016-01-01

This paper presents a transient-enhanced NMOS low-dropout regulator (LDO) for portable applications with parallel feedback compensation. The parallel feedback structure adds a dynamic zero to get an adequate phase margin with a load current variation from 0 to 1 A. A class-AB error amplifier and a fast charging/discharging unit are adopted to enhance the transient performance. The proposed LDO has been implemented in a 0.35 μm BCD process. From experimental results, the regulator can operate with a minimum dropout voltage of 150 mV at a maximum 1 A load and I Q of 165 μA. Under the full range load current step, the voltage undershoot and overshoot of the proposed LDO are reduced to 38 mV and 27 mV respectively. (paper)

Proceedings of the USNRC/EPRI/ANL heated crevice seminar.

Energy Technology Data Exchange (ETDEWEB)

Park, J. Y.; Fruzzetti, K.; Muscara, J.; Diercks, D. R.; Energy Technology; EPRI; USNRC

2003-08-31

An international Heated Crevice Seminar, sponsored by the Division of Engineering Technology, Office of Nuclear Regulatory Research, U.S. Nuclear Regulatory Commission, Argonne National Laboratory, and the Electric Power Research Institute, was held at Argonne National Laboratory on October 7-11, 2002. The objective of the seminar was to provide a working forum for the exchange of information by contributing experts on current issues related to corrosion in heated crevices, particularly as it relates to the integrity of PWR steam generator tubes. Forty-five persons from six countries attended the seminar, including representatives from government agencies, private industry and consultants, government research laboratories, nuclear vendors, and electrical utilities. The seminar opened with keynote talks on secondary-side crevice environments associated with IGA and IGSCC of mill-annealed Alloy 600 steam generator tubes and the submodes of corrosion in heat transfer crevices. This was followed by technical sessions on (1) Corrosion in Crevice Geometries, (2) Experimental Methods, (3) Results from Experimental Studies, and (4) Modeling. The seminar concluded with a panel discussion on the present understanding of corrosive processes in heated crevices and future research needs.

Radiation protection seminar

International Nuclear Information System (INIS)

2012-01-01

The Radiation Protection Seminar, was organized by the Argentina Association of Biology and Nuclear Medicine, and Bacon Laboratory, the 20 june 2012, in the Buenos Aires city of Argentina. In this event were presented some papers on the following topics: methods of decontamination, radiation protection of patients; concepts of radiation protection and dosimetry.

High precision, low disturbance calibration of the High Voltage system of the CMS Barrel Electromagnetic Calorimeter

CERN Document Server

Marzocchi, Badder

2017-01-01

The CMS Electromagnetic Calorimeter is made of scintillating lead tungstate crystals, using avalanche photodiodes (APD) as photo-detectors in the barrel part. The high voltage system, consisting of 1224 channels, biases groups of 50 APD pairs, each at a voltage of about 380 V. The APD gain dependence on the voltage is 3pct/V. A stability of better than 60 mV is needed to have negligible impact on the calorimeter energy resolution. Until 2015 manual calibrations were performed yearly. A new calibration system was deployed recently, which satisfies the requirement of low disturbance and high precision. The system is discussed in detail and first operational experience is presented.

Low-voltage 96 dB snapshot CMOS image sensor with 4.5 nW power dissipation per pixel.

Science.gov (United States)

Spivak, Arthur; Teman, Adam; Belenky, Alexander; Yadid-Pecht, Orly; Fish, Alexander

2012-01-01

Modern "smart" CMOS sensors have penetrated into various applications, such as surveillance systems, bio-medical applications, digital cameras, cellular phones and many others. Reducing the power of these sensors continuously challenges designers. In this paper, a low power global shutter CMOS image sensor with Wide Dynamic Range (WDR) ability is presented. This sensor features several power reduction techniques, including a dual voltage supply, a selective power down, transistors with different threshold voltages, a non-rationed logic, and a low voltage static memory. A combination of all these approaches has enabled the design of the low voltage "smart" image sensor, which is capable of reaching a remarkable dynamic range, while consuming very low power. The proposed power-saving solutions have allowed the maintenance of the standard architecture of the sensor, reducing both the time and the cost of the design. In order to maintain the image quality, a relation between the sensor performance and power has been analyzed and a mathematical model, describing the sensor Signal to Noise Ratio (SNR) and Dynamic Range (DR) as a function of the power supplies, is proposed. The described sensor was implemented in a 0.18 um CMOS process and successfully tested in the laboratory. An SNR of 48 dB and DR of 96 dB were achieved with a power dissipation of 4.5 nW per pixel.

Low-Voltage Ride-Through of Variable Speed Wind Turbines with Permanent Magnet Synchronous Generator

DEFF Research Database (Denmark)

Deng, Fujin; Chen, Zhe

2009-01-01

This paper presents a simulation model of a MW-level variable speed wind turbine with a permanent magnet synchronous generator (PMSG) and a full-scale converter developed in the simulation tool of PSCAD/EMTDC. The low voltage ride-through (LVRT) capability of the wind turbine is investigated. A new...... control scheme for the wind turbine that keeps it connected to the grid during grid faults is designed and simulated. Its design has special focus on the regulation of the DC-link voltage. Simulation results show the proposed control scheme is an effective measure to improve LVRT capability of variable...

Low-Power, Low-Voltage Resistance-to-Digital Converter for Sensing Applications

Directory of Open Access Journals (Sweden)

Sergey Y. YURISH

2016-09-01

Full Text Available IC (ASIP of Universal Sensors and Transducers Interface (USTI-MOB with low power consumption, working in the resistive measurement mode (one of 26 possible measuring modes is described in the article. The proposed IC has 20 W to 4.5 M W range of measurement, relative error< ±0.04 %, 0.85 mA supply current and 1.2 V supply voltage. The worst-case error of about< ±1.54 % is observed. IC has three popular serial interfaces: I2C, SPI and RS232/USB. Due to high metrological performance and technical characteristics the USTI- MOB is well suitable for such application as: sensor systems for IoT, wearable and mobile devices, and digital multimeters. The ICs can also work with any quasi-digital resistive converters, in which the resistance is converted to frequency, period, duty-cycle or pulse width.

An inductor-based converter with EMI reduction for low-voltage thermoelectric energy harvesting

Science.gov (United States)

Wang, Chuang; Zhao, Kai; Li, Zunchao

2017-07-01

This paper presents a self-powered inductor-based converter which harvests thermoelectric energy and boosts extremely low voltage to a typical voltage level for supplying body sensor nodes. Electromagnetic interference (EMI) of the converter is reduced by spreading spectrum of fundamental frequency and harmonics via pseudo-random modulation, which is obtained via combining the linear feedback shift register and digitally controlled oscillator. Besides, the methods, namely extracting energy near MPP and reducing the power dissipation, are employed to improve the power efficiency. The presented inductor-based converter is designed and verified in CSMC CMOS 0.18-µm 1P6M process. The results reveal that it achieves the high efficiency and EMI reduction at the same time.

Innovative energy efficient low-voltage electron beam emitters

International Nuclear Information System (INIS)

Felis, Kenneth P.; Avnery, Tovi; Berejka, Anthony J.

2002-01-01

Advanced electron beams (AEB) has developed a modular, low voltage (80-125 keV), high beam current (up to 40 ma), electron emitter with typically 25 cm of beam width, that is housed in an evacuated, returnable chamber that is easy to plug in and connect. The latest in nanofabrication enables AEB to use an ultra-thin beam window. The power supply for AEB's emitter is based on solid-state electronics. This combination of features results in a remarkable electrical efficiency. AEB's electron emitter relies on a touch screen, computer control system. With 80 μm of unit density beam penetration, AEB's electron emitter has gained market acceptance in the curing of opaque, pigmented inks and coatings used on flexible substrates, metals and fiber composites and in the curing of adhesives in foil based laminates

Innovative energy efficient low-voltage electron beam emitters

Science.gov (United States)

Felis, Kenneth P.; Avnery, Tovi; Berejka, Anthony J.

2002-03-01

Advanced electron beams (AEB) has developed a modular, low voltage (80-125 keV), high beam current (up to 40 ma), electron emitter with typically 25 cm of beam width, that is housed in an evacuated, returnable chamber that is easy to plug in and connect. The latest in nanofabrication enables AEB to use an ultra-thin beam window. The power supply for AEB's emitter is based on solid-state electronics. This combination of features results in a remarkable electrical efficiency. AEB's electron emitter relies on a touch screen, computer control system. With 80 μm of unit density beam penetration, AEB's electron emitter has gained market acceptance in the curing of opaque, pigmented inks and coatings used on flexible substrates, metals and fiber composites and in the curing of adhesives in foil based laminates.

Low-tube-voltage selection for non-contrast-enhanced CT: Comparison of the radiation dose in pediatric and adult phantoms.

Science.gov (United States)

Shimonobo, Toshiaki; Funama, Yoshinori; Utsunomiya, Daisuke; Nakaura, Takeshi; Oda, Seitaro; Kiguchi, Masao; Masuda, Takanori; Sakabe, Daisuke; Yamashita, Yasuyuki; Awai, Kazuo

2016-01-01

We used pediatric and adult anthropomorphic phantoms to compare the radiation dose of low- and standard tube voltage chest and abdominal non-contrast-enhanced computed tomography (CT) scans. We also discuss the optimal low tube voltage for non-contrast-enhanced CT. Using a female adult- and three differently-sized pediatric anthropomorphic phantoms we acquired chest and abdominal non-contrast-enhanced scans on a 320-multidetector CT volume scanner. The tube voltage was set at 80-, 100-, and 120 kVp. The tube current was automatically assigned on the CT scanner in response to the set image noise level. On each phantom and at each tube voltage we measured the surface and center dose using high-sensitivity metal-oxide-semiconductor field-effect transistor detectors. The mean surface dose of chest and abdominal CT scans in 5-year olds was 4.4 and 5.3 mGy at 80 kVp, 4.5 and 5.4 mGy at 100 kV, and 4.0 and 5.0 mGy at 120 kVp, respectively. These values were similar in our 3-pediatric phantoms (p > 0.05). The mean surface dose in the adult phantom increased from 14.7 to 19.4 mGy for chest- and from 18.7 to 24.8 mGy for abdominal CT as the tube voltage decreased from 120 to 80 kVp (p voltage and the low tube voltage technique can be used for non-contrast-enhanced chest- and abdominal scanning. Copyright © 2015 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Solution-processed p-type copper(I) thiocyanate (CuSCN) for low-voltage flexible thin-film transistors and integrated inverter circuits

KAUST Repository

Petti, Luisa

2017-03-17

We report on low operating voltage thin-film transistors (TFTs) and integrated inverters based on copper(I) thiocyanate (CuSCN) layers processed from solution at low temperature on free-standing plastic foils. As-fabricated coplanar bottom-gate and staggered top-gate TFTs exhibit hole-transporting characteristics with average mobility values of 0.0016 cm2 V−1 s−1 and 0.013 cm2 V−1 s−1, respectively, current on/off ratio in the range 102–104, and maximum operating voltages between −3.5 and −10 V, depending on the gate dielectric employed. The promising TFT characteristics enable fabrication of unipolar NOT gates on flexible free-standing plastic substrates with voltage gain of 3.4 at voltages as low as −3.5 V. Importantly, discrete CuSCN transistors and integrated logic inverters remain fully functional even when mechanically bent to a tensile radius of 4 mm, demonstrating the potential of the technology for flexible electronics.

PROGRAMME OF SEMINARS MARCH TO JUNE 2004

CERN Multimedia

Nathalie Dumeaux

2004-01-01

Situation : 09.03.2004 Dates Days Places Available* Bilingual seminars Communication Techniques-1 16, 17, 18 March 3 no Project Management 17, 18, 19 March 3 yes Introduction to Management 23, 24, 25 March 3 yes Communication Techniques-1 8, 9, 10 June 3 yes Quality Management 5, 6, 7 may 3 yes Introduction to Management - Follow-up 22, 23 June 1,5 yes Seminars in English Making Presentations 22, 23 March & 1 April 3 yes Stress Management 22, 23 April 2 yes Chairing or participating in meetings 11, 12, 13 May 3 yes *If you are interested in a seminar where there are no places available, please fill in an application form and we will contact you as soon as a new session is organised. MANAGEMENT & COMMUNICATION Nathalie Dumeaux tel. 781 44 management.communication@cern.ch

Study of the effect of Pyrophosphate in low voltage Plasma Electrolytic Oxidation on the corrosion resistance of AZ31B Magnesium alloy

International Nuclear Information System (INIS)

Yun, Jae Gon; Kim, Eng Chan; Kim, Ki Hong

2016-01-01

In this study, low voltage Plasma Electrolytic Oxidation (PEO) was utilized to eliminate the drawbacks of high voltage PEO such as high cost, dimensional deformation, and porosity. Low voltage PEO produces a thin coating, which leads to low corrosion resistance. In order to solve this problem, 0.1⁓0.6 M pyrophosphates were added to a bath containing 1.4 M NaOH and 0.35 M Na_2SiO_3.PEO at 70V was conducted at 25℃ for 3 minutes. The chemical composition, morphology, and corrosion resistance of the anodized coating were analyzed. The anodized film was composed of MgO, Mg_2SiO_4, and Mg_2O_7P_2. Themorphology of the film showed a inappropriately dense structure and low porosity in the anodized layers. It is found that low voltage Plasma Electrolytic Oxidation in cooperation with phosphating treatment can provide good corrosion protection for the AZ31B magnesium alloy.

Study of the effect of Pyrophosphate in low voltage Plasma Electrolytic Oxidation on the corrosion resistance of AZ31B Magnesium alloy

Energy Technology Data Exchange (ETDEWEB)

Yun, Jae Gon; Kim, Eng Chan [Yeungnam University, Gyeongsan (Korea, Republic of); Kim, Ki Hong [Catholic University of Daegu, Gyeongsan (Korea, Republic of)

2016-01-15

In this study, low voltage Plasma Electrolytic Oxidation (PEO) was utilized to eliminate the drawbacks of high voltage PEO such as high cost, dimensional deformation, and porosity. Low voltage PEO produces a thin coating, which leads to low corrosion resistance. In order to solve this problem, 0.1⁓0.6 M pyrophosphates were added to a bath containing 1.4 M NaOH and 0.35 M Na{sub 2}SiO{sub 3}.PEO at 70V was conducted at 25℃ for 3 minutes. The chemical composition, morphology, and corrosion resistance of the anodized coating were analyzed. The anodized film was composed of MgO, Mg{sub 2}SiO{sub 4}, and Mg{sub 2}O{sub 7}P{sub 2}. Themorphology of the film showed a inappropriately dense structure and low porosity in the anodized layers. It is found that low voltage Plasma Electrolytic Oxidation in cooperation with phosphating treatment can provide good corrosion protection for the AZ31B magnesium alloy.

NKS/SOS-1 Seminar on Safety analysis. Report from a seminar held on 22-23 March 2000 Risø National Laboratory, Roskilde, DK

DEFF Research Database (Denmark)

The report describes presentations and discussions at a seminar held at Risø on March 22-23, 2000. The title of the seminar was NKS/SOS-1 – Safety Analysis. It dealt with issues of relevance for the safety analysis for the entire nuclear safety field (notably reactors and nuclear waste repositories......). Such issues were: objectives of safety analysis, risk criteria, decision analysis, expert judgement and risk communication. In addition, one talk dealt with criteria for chemical industries in Europe. The seminar clearly showed that the concept of risk is multi-dimensional, which makes clarity...

A High-Voltage Low-Power Switched-Capacitor DC-DC Converter Based on GaN and SiC Devices for LED Drivers

DEFF Research Database (Denmark)

Fan, Lin; Knott, Arnold; Jørgensen, Ivan Harald Holger

2018-01-01

Previous research on switched-capacitor DC-DC converters has focused on low-voltage and/or high-power ranges where the efficiencies are dominated by conduction loss. Switched-capacitor DC-DC converters at high-voltage (> 100 V) low-power (high efficiency and high power density...... are anticipated to emerge. This paper presents a switched-capacitor converter with an input voltage up to 380 V (compatible with rectified European mains) and a maximum output power of 10 W. GaN switches and SiC diodes are analytically compared and actively combined to properly address the challenges at high......-voltage low-current levels, where switching loss becomes significant. Further trade-off between conduction loss and switching loss is experimentally optimized with switching frequencies. Three variant designs of the proposed converter are implemented, and the trade-off between the efficiency and the power...

Sustainable roadway lighting seminar.

Science.gov (United States)

2014-07-01

The objective of this project was to develop and conduct a half-day educational seminar on sustainable : roadway lighting at three locations within New York State: Rochester, New York City, and Albany. : Primary attendees were engineers from the New ...

An Ultra-Low Voltage Analog Front End for Strain Gauge Sensory System Application in 0.18µm CMOS

Science.gov (United States)

Edward, Alexander; Chan, Pak Kwong

This paper presents analysis and design of a new ultra-low voltage analog front end (AFE) dedicated to strain sensor applications. The AFE, designed in 0.18µm CMOS process, features a chopper-stabilized instrumentation amplifier (IA), a balanced active MOSFET-C 2nd order low pass filter (LPF), a clock generator and a voltage booster which operate at supply voltage (Vdd) of 0.6V. The designed IA achieves 30dB of closed-loop gain, 101dB of common-mode rejection ratio (CMRR) at 50Hz, 80dB of power-supply rejection ratio (PSRR) at 50Hz, thermal noise floor of 53.4 nV/√Hz, current consumption of 14µA, and noise efficiency factor (NEF) of 9.7. The high CMRR and rail-to-rail output swing capability is attributed to a new low voltage realization of the active-bootstrapped technique using a pseudo-differential gain-boosting operational transconductance amplifier (OTA) and proposed current-driven bulk (CDB) biasing technique. An output capacitor-less low-dropout regulator (LDO), with a new fast start-up LPF technique, is used to regulate this 0.6V supply from a 0.8-1.0V energy harvesting power source. It achieves power supply rejection (PSR) of 42dB at frequency of 1MHz. A cascode compensated pseudo differential amplifier is used as the filter's building block for low power design. The filter's single-ended-to-balanced converter is implemented using a new low voltage amplifier with two-stage common-mode cancellation. The overall AFE was simulated to have 65.6dB of signal-to-noise ratio (SNR), total harmonic distortion (THD) of less than 0.9% for a 100Hz sinusoidal maximum input signal, bandwidth of 2kHz, and power consumption of 51.2µW. Spectre RF simulations were performed to validate the design using BSIM3V3 transistor models provided by GLOBALFOUNDRIES 0.18µm CMOS process.

Artificial Intelligence Applications to Learning and Training. Occasional Paper--InTER/2/88.

Science.gov (United States)

Cumming, Geoff

This report summarizes and interprets the discussions at a seminar on artificial intelligence (AI) training domains and knowledge representations which was sponsored by the United Kingdom Training Commission. The following broad areas are addressed: (1) the context, process, and diversity of requirements of training and training needs; (2)…

Method to Minimize the Low-Frequency Neutral-Point Voltage Oscillations With Time-Offset Injection for Neutral-Point-Clamped Inverters

DEFF Research Database (Denmark)

Choi, Ui-Min; Blaabjerg, Frede; Lee, Kyo-Beum

2015-01-01

time of small- and medium-voltage vectors. However, if the power factor is lower, there is a limitation to eliminate neutral-point oscillations. In this case, the proposed method can be improved by changing the switching sequence properly. Additionally, a method for neutral-point voltage balancing......This paper proposes a method to reduce the low-frequency neutral-point voltage oscillations. The neutral-point voltage oscillations are considerably reduced by adding a time offset to the three-phase turn-on times. The proper time offset is simply calculated considering the phase currents and dwell...

Low Voltage Current Mode Switched-Current-Mirror Mixer

Directory of Open Access Journals (Sweden)

Chunhua Wang

2009-09-01

Full Text Available A new CMOS active mixer topology can operate at 1 V supply voltage by use of SCM (switched currentmirror. Such current-mode mixer requires less voltage headroom with good linearization. Mixing is achieved with four improved current mirrors, which are alternatively activated. For ideal switching, the operation is equivalent to a conventional active mixer. This paper analyzes the performance of the SCM mixer, in comparison with the conventional mixer, demonstrating competitive performance at a lower supply voltage. Moreover, the new mixer’s die, without any passive components, is very small, and the conversion gain is easy to adjust. An experimental prototype was designed and simulated in standard chartered 0.18μm RF CMOS Process with Spectre in Cadence Design Systems. Experimental results show satisfactory mixer performance at 2.4 GHz.

Organizing a Campus Seminar on Careers in Entertainment.

Science.gov (United States)

Walt Disney Productions, Anaheim, CA.

Developed by Walt Disney Productions as part of a project granted by the Career Education Program of the Office of Education, this handbook is designed to help college and university fine arts departments in planning and carrying out an on-campus seminar on careers in entertainment. Sections include Why Hold a Seminar on Careers in Entertainment?,…

The European Foundation for Quality Management (EFQM Excellence Model in a Low Voltage Switchgear Compan

Directory of Open Access Journals (Sweden)

Özgür Özmen

2017-11-01

Full Text Available The Turkish low voltage switchgear sector is made up of several local and international companies. Generally, local companies operating in this sector try to get a competitive advantage by fabricating cheap products, in order to cope with the competition that focuses more on quality. What’s more, international corporations perform quality activities under the organization and control of their top-managements from abroad. Although VIKO is a local producer, it is a company willing to invest more in quality, as well as in research and development. VIKO company is the focus of this self-assessment study, since it lies at the conjunction of companies operating in this sector, it being a local company performing various quality enhancement activities. Simultaneously, the authors consider that this study shall prove useful to create an overview over the entire Turkish low voltage switchgear sector. The evaluation of the company and its core-activities was based upon nine criteria of the European Foundation for Quality Management (EFQM Excellence Model, in order to identify the strengths, the weaknesses and aspects that require improvements. This is the first study worldwide performed in the low voltage switchgear sector and it is aimed at motivating other Turkish companies that operate in this sector to implement The European Foundation for Quality Management (EFQM Excellence Model in their TQM activities (Total Quality Management.

A dynamic voltage restorer (DVR) with selective harmonic compensation at medium voltage level

DEFF Research Database (Denmark)

Newman, M.J.; Holmes, D.G.; Nielsen, J.G.

2005-01-01

Dynamic voltage restorers (DVRs) are now becoming more established in industry to reduce the impact of voltage sags to sensitive loads. However, DVRs spend most of their time in standby mode, since voltage sags occur very infrequently, and hence their utilization is low. In principle, it would...... be advantageous if the series-connected inverter of a DVR could also be used to compensate for any steady-state load voltage harmonics, since this would increase the power quality "value-added" benefits to the grid system. However, before this can be done, consideration must be given to the control of steady......-state power through the DVR, the increased losses, and the low modulation depths at which the scheme must operate to achieve acceptable harmonic compensation performance. This paper presents a selective harmonic feedback control strategy that can be easily added to medium-voltage DVR systems to provide...

Seminar on gamma-gamma physics

International Nuclear Information System (INIS)

1984-04-01

The following subjects have been studied in this seminar: photon pair production, hard scattering processes in photon-photon and electron-photon collisions, radiative corrections, final state interactions

High-Efficiency Isolated Boost DCDC Converter for High-Power Low-Voltage Fuel-Cell Applications

DEFF Research Database (Denmark)

Nymand, Morten; Andersen, Michael A. E.

2010-01-01

high winding losses. The analysis of transformer leakage inductance reveals that extremely low leakage inductance can be achieved, allowing stored energy to be dissipated. Power MOSFETs fully rated for repetitive avalanches allow primary-side voltage clamp circuits to be eliminated. The oversizing...

Interface Engineering with MoS2 -Pd Nanoparticles Hybrid Structure for a Low Voltage Resistive Switching Memory.

Science.gov (United States)

Wang, Xue-Feng; Tian, He; Zhao, Hai-Ming; Zhang, Tian-Yu; Mao, Wei-Quan; Qiao, Yan-Cong; Pang, Yu; Li, Yu-Xing; Yang, Yi; Ren, Tian-Ling

2018-01-01

Metal oxide-based resistive random access memory (RRAM) has attracted a lot of attention for its scalability, temperature robustness, and potential to achieve machine learning. However, a thick oxide layer results in relatively high program voltage while a thin one causes large leakage current and a small window. Owing to these fundamental limitations, by optimizing the oxide layer itself a novel interface engineering idea is proposed to reduce the programming voltage, increase the uniformity and on/off ratio. According to this idea, a molybdenum disulfide (MoS 2 )-palladium nanoparticles hybrid structure is used to engineer the oxide/electrode interface of hafnium oxide (HfO x )-based RRAM. Through its interface engineering, the set voltage can be greatly lowered (from -3.5 to -0.8 V) with better uniformity under a relatively thick HfO x layer (≈15 nm), and a 30 times improvement of the memory window can be obtained. Moreover, due to the atomic thickness of MoS 2 film and high transmittance of ITO, the proposed RRAM exhibits high transparency in visible light. As the proposed interface-engineering RRAM exhibits good transparency, low SET voltage, and a large resistive switching window, it has huge potential in data storage in transparent circuits and wearable electronics with relatively low supply voltage. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Preface to 18. Chemnitz seminar on materials engineering

International Nuclear Information System (INIS)

2016-01-01

The Institute of Materials Science and Engineering (Institut für Werkstoffwissenschaft und Werkstofftechnik, IWW) is a well-established part of the Faculty of Mechanical Engineering at Technische Universität Chemnitz, Germany. We are proud to host our traditional scientific meeting, the Chemnitz Seminar on Materials Engineering - Werkstofftechnisches Kolloquium, this year being the 18 th Seminar. The aim of our meeting is to bring together scientists and engineers both from academia and industry, and this is reflected by the different scientific sessions that cover various relevant topics, such as composite materials, microstructural analysis, and surface engineering. Special focus sessions highlight recent developments in the Federal Cluster of Excellence MERGE and in the Collaborative Research Center SFB 692, both established in Chemnitz. We, as organizers, continuously strive to improve our Seminar, and we therefore decided to provide all contributors with the opportunity to publish their papers, in addition to the printed Proceedings volume, in an international, peer-reviewed journal. Publication in IOP Conference Series: Materials Science and Engineering allows for a wide dissemination of the many interesting and relevant results presented in our Seminar. Clearly, this is understood and appreciated by many participants of our meeting: more than 65% of all authors chose to also publish their Proceedings papers in this special issue, which consequently provides an excellent overview of the main topics of our Seminar. Chemnitz, March 2016 Prof. Thomas Lampke Prof. Guntram Wagner Prof. Martin F.-X. Wagner (paper)

Specificity of "Live High-Train Low" altitude training on exercise performance

DEFF Research Database (Denmark)

Bejder, Jacob; Nordsborg, Nikolai Baastrup

2018-01-01

The novel hypothesis that "Live High-Train Low" (LHTL) does not improve sport-specific exercise performance (e.g., time trial) is discussed. Indeed, many studies demonstrate improved performance after LHTL but unfortunately control groups are often lacking, leaving open the possibility of training...

Eddy current seminar

International Nuclear Information System (INIS)

Emson, C.R.I.

1988-11-01

The paper presents the fifth symposium in the series of Eddy Current Seminars, held in Abingdon, 1988. The meeting included a discussion on three-dimensional eddy current formulations, as well as thirteen contributed papers on computational electromagnetics. Of the thirteen papers, two papers on eddy currents in tokamaks were selected for INIS and indexed separately. (U.K.)

Efficacy of Low-Cost PC-Based Aviation Training Devices

Directory of Open Access Journals (Sweden)

Savern l Reweti

2017-03-01

Full Text Available Aim/Purpose: The aim of this study was to explore whether a full cost flight training device (FTD was significantly better for simulator training than a low cost PC-Based Aviation Training Device (PCATD. Background: A quasi-transfer study was undertaken to ascertain whether a Civil Aviation Authority certified Flight Training Device (FTD was more effective at improving pilot proficiency in the performance of a standard VFR traffic pattern (Overhead Rejoin Procedure than a customised low cost PCATD. Methodology: In this quasi-transfer study, a high fidelity FTD rather than an aircraft was used to test both training and transfer tasks. Ninety-three pilots were recruited to participate in the study. Contribution: The use of PCATDs is now well established for pilot training, especially for Instrument Flight Rules (IFR skills training. However, little substantive research has been undertaken to examine their efficacy for VFR training. Findings: There was no evidence of a pre-test/post-test difference in VFR task perfor-mance between participants trained on the PCATD and the FTD, when post tested on the FTD. The use of both PCATD and FTD demonstrated signifi-cant improvements in VFR task performance compared to a control group that received no PCATD or FTD training. Recommendations for Practitioners\t: We discuss the possibility that low cost PCATDs may be a viable alternative for flight schools wishing to use a flight simulator but not able to afford a FTD. Recommendation for Researchers: We discuss the introduction of improved low cost technologies that allow PCATDs to be used more effectively for training in VFR procedures. The development and testing of new technologies requires more research. Impact on Society: Flight training schools operate in a difficult economic environment with continued increases in the cost of aircraft maintenance, compliance costs, and aviation fuel. The increased utilisation of low cost PCATD’s especially for VFR

Report from Dagstuhl Seminar 12331 Mobility Data Mining and Privacy

OpenAIRE

Clifton, Christopher W.; Kuijpers, Bart; Morik, Katharina; Saygin, Yucel

2012-01-01

This report documents the program and the outcomes of Dagstuhl Seminar 12331 “Mobility Data Mining and Privacy”. Mobility data mining aims to extract knowledge from movement behaviour of people, but this data also poses novel privacy risks. This seminar gathered a multidisciplinary team for a conversation on how to balance the value in mining mobility data with privacy issues. The seminar focused on four key issues: Privacy in vehicular data, in cellular data, context- dependent privacy, and ...

Reduced Voltage Scaling in Clock Distribution Networks

Directory of Open Access Journals (Sweden)

Khader Mohammad

2009-01-01

Full Text Available We propose a novel circuit technique to generate a reduced voltage swing (RVS signals for active power reduction on main buses and clocks. This is achieved without performance degradation, without extra power supply requirement, and with minimum area overhead. The technique stops the discharge path on the net that is swinging low at a certain voltage value. It reduces active power on the target net by as much as 33% compared to traditional full swing signaling. The logic 0 voltage value is programmable through control bits. If desired, the reduced-swing mode can also be disabled. The approach assumes that the logic 0 voltage value is always less than the threshold voltage of the nMOS receivers, which eliminate the need of the low to high voltage translation. The reduced noise margin and the increased leakage on the receiver transistors using this approach have been addressed through the selective usage of multithreshold voltage (MTV devices and the programmability of the low voltage value.

Influence of X and gamma radiation and bias conditions on dropout voltage of voltage regulators serial transistors

International Nuclear Information System (INIS)

Vukic, V.; Osmokrovic, P.; Stankovic, S.; Kovacevic, M.

2005-01-01

Research topic presented in this paper is degradation of characteristics of low-dropout voltage regulator's serial transistor during exposure of device to the ionizing radiation. Voltage regulators were exposed to X and γ radiation in two modes: without bias conditions, and with bias conditions and load. Tested circuits are representatives of the first and the second generation of low-dropout voltage regulators, with lateral and vertical PNP serial transistor: LM2940 and L4940. Experimental results of output voltage and serial dropout voltage change in function of total ionizing dose, during the medium-dose-rate exposure, were presented. (author) [sr

Simulating threshold voltage shift of MOS devices due to radiation in the low-dose range

CERN Document Server

Wan Xin Heng; Gao Wen Yu; Huang Ru; Wang Yang Yuan

2002-01-01

An analytical MOSFET threshold voltage shift model due to radiation in the low-dose range has been developed for circuit simulations. Experimental data in the literature shows that the model predictions are in good agreement. It is simple in functional form and hence computationally efficient. It can be used as a basic circuit simulation tool for analysing MOSFET exposed to a nuclear environment up to about 1 Mrad(Si). In accordance with common believe, radiation induced absolute change of threshold voltage was found to be larger in irradiated PMOS devices. However, if the radiation sensitivity is defined in the way authors did it, the results indicated NMOS rather than PMOS devices are more sensitive, specially at low doses. This is important from the standpoint of their possible application in dosimetry

Static Voltage Stability Analysis by Using SVM and Neural Network

Directory of Open Access Journals (Sweden)

Mehdi Hajian

2013-01-01

Full Text Available Voltage stability is an important problem in power system networks. In this paper, in terms of static voltage stability, and application of Neural Networks (NN and Supported Vector Machine (SVM for estimating of voltage stability margin (VSM and predicting of voltage collapse has been investigated. This paper considers voltage stability in power system in two parts. The first part calculates static voltage stability margin by Radial Basis Function Neural Network (RBFNN. The advantage of the used method is high accuracy in online detecting the VSM. Whereas the second one, voltage collapse analysis of power system is performed by Probabilistic Neural Network (PNN and SVM. The obtained results in this paper indicate, that time and number of training samples of SVM, are less than NN. In this paper, a new model of training samples for detection system, using the normal distribution load curve at each load feeder, has been used. Voltage stability analysis is estimated by well-know L and VSM indexes. To demonstrate the validity of the proposed methods, IEEE 14 bus grid and the actual network of Yazd Province are used.

NKS/SOS-1 seminar on quality assurance