Gender Analysis Of Electronic Information Resource Use: The Case ...

African Journals Online (AJOL)

Based on the findings the study concluded that access and use of electronic information resources creates a “social digital divide” along gender lines. The study ... Finally, the library needs to change its marketing strategies on the availability of electronic information resources to increase awareness of these resources.

Users satisfaction with electronic information resources and services ...

African Journals Online (AJOL)

This study investigated users satisfaction on the use of electronic information resources and services in MTN Net libraries in ABU & UNIBEN. Two objectives and one null hypotheses were formulated and tested with respect to the users' satisfaction on electronic information resources and services in MTN Net libraries in ...

A Novel Dual-Band Rectenna for Ambient RF Energy Harvesting at GSM 900 MHz and 1800 MHz

Directory of Open Access Journals (Sweden)

Dinh Khanh Ho

2017-06-01

Full Text Available This paper presents a novel dual-band rectenna for RF energy harvesting system. This rectenna is created from a dual-band antenna and a dual-band rectifier which operates at GSM bands (900 MHz and 1800 MHz. The printed monopole antenna is miniaturized by two meander-lines. The received signal from the receiving antenna is rectified by a voltage double using Schottky diode SMS-7630. The rectifier is optimized for low input power level of -20dBm using harmonic balance. Prototype is designed and fabricated. The simulation is validated by measurement with power conversion efficiency of 20% and 40.8% (in measurement at the input power level of -20dBm. The proposed rectenna has output voltage from 183-415 mV. From the measured results, this rectenna provides the possibility to harvest the ambient electromagnetic energy for powering low-power electronic devices.

120 MW, 800 MHz Magnicon for a Future Muon Collider

International Nuclear Information System (INIS)

Jay L. Hirshfield

2005-01-01

Development of a pulsed magnicon at 800 MHz was carried out for the muon collider application, based on experience with similar amplifiers in the frequency range between 915 MHz and 34.3 GHz. Numerical simulations using proven computer codes were employed for the conceptual design, while established design technologies were incorporated into the engineering design. A cohesive design for the 800 MHz magnicon amplifier was carried out, including design of a 200 MW diode electron gun, design of the magnet system, optimization of beam dynamics including space charge effects in the transient and steady-state regimes, design of the drive, gain, and output cavities including an rf choke in the beam exit aperture, analysis of parasitic oscillations and design means to eliminate them, and design of the beam collector capable of 20 kW average power operation

Organizational matters of competition in electronic educational resources

Directory of Open Access Journals (Sweden)

Ирина Карловна Войтович

2015-12-01

Full Text Available The article examines the experience of the Udmurt State University in conducting competitions of educational publications and electronic resources. The purpose of such competitions is to provide methodological support to educational process. The main focus is on competition of electronic educational resources. The technology of such contests is discussed through detailed analysis of the main stages of the contest. It is noted that the main task of the preparatory stage of the competition is related to the development of regulations on competition and the definition of criteria for selection of the submitted works. The paper also proposes a system of evaluation criteria of electronic educational resources developed by members of the contest organizing committee and jury members. The article emphasizes the importance of not only the preparatory stages of the competition, but also measures for its completion, aimed at training teachers create quality e-learning resources.

CHALLENGES OF ELECTRONIC INFORMATION RESOURCES IN ...

African Journals Online (AJOL)

This paper discusses the role of policy for proper and efficient library services in the electronic era. It points out some of the possible dangers of embarking in electronic resources without a proper focus at hand. Thus, it calls for today's librarians and policy makers to brainstorm and come up with working policies suitable to ...

Evaluation Of Electromagnetic Fields For Frequencies 900 MHz-1 800 MHz In Tirana

Directory of Open Access Journals (Sweden)

Kuqi Dhurata

2015-07-01

Full Text Available Abstract The massive use of mobile phone as a communication tool nowadays is accompanied the ever increasing interest of the public and researchers for the possibly impact on human health as a result of exposure to the electromagnetic fields that accompany these devices. Therefore knowing the level of exposure electromagnetic fields of this electronic equipment has been and will be in the future interest object to the public and the subject of study for the researchers. In this paper are presents the results of measurements of electromagnetic fields for the frequencies 900 MHz - 1800 MHz used in mobile telephone in Tirana. These frequencies are included in the area radio frequency RF and Microwave MW 300 Hz - 300 GHz in the spectrum of electromagnetic waves and belong to non-ionizing radiation. The measurements were performed in different areas of Tirana. The purpose is to assess the level of exposure electromagnetic fields especially near areas where mobile antennas are mounted construction of dynamic digital mapping and comparison with the permitted levels of the exposure defined by the International Commission of Non Ionizing Radiation Protection ICNIRP. Through this publication the aim of the authors is to provide real information and reliable for the population.

Use of Electronic Resources in a Private University in Nigeria ...

African Journals Online (AJOL)

The study examined awareness and constraints in the use of electronic resources by lecturers and students of Ajayi Crowther University, Oyo, Nigeria. It aimed at justifying the resources expended in the provision of electronic resources in terms of awareness, patronage and factors that may be affecting awareness and use ...

Electronic Resources Management System: Recommendation Report 2017

KAUST Repository

Ramli, Rindra M.

2017-05-01

This recommendation report provides an overview of the selection process for the new Electronic Resources Management System. The library has decided to move away from Innovative Interfaces Millennium ERM module. The library reviewed 3 system as potential replacements namely: Proquest 360 Resource Manager, Ex Libris Alma and Open Source CORAL ERMS. After comparing and trialling the systems, it was decided to go for Proquest 360 Resource Manager.

use of electronic resources by graduate students of the department

African Journals Online (AJOL)

respondent's access electronic resources from the internet via Cybercafé .There is a high ... KEY WORDS: Use, Electronic Resources, Graduate Students, Cybercafé. INTRODUCTION ... Faculty of Education, University of Uyo, Uyo. Olu Olat ...

Electronic resource management practical perspectives in a new technical services model

CERN Document Server

Elguindi, Anne

2012-01-01

A significant shift is taking place in libraries, with the purchase of e-resources accounting for the bulk of materials spending. Electronic Resource Management makes the case that technical services workflows need to make a corresponding shift toward e-centric models and highlights the increasing variety of e-formats that are forcing new developments in the field.Six chapters cover key topics, including: technical services models, both past and emerging; staffing and workflow in electronic resource management; implementation and transformation of electronic resource management systems; the ro

47 CFR 15.242 - Operation in the bands 174-216 MHz and 470-668 MHz.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 1 2010-10-01 2010-10-01 false Operation in the bands 174-216 MHz and 470-668... bands 174-216 MHz and 470-668 MHz. (a) The marketing and operation of intentional radiators under the... services, facilities, and beds for use beyond 24 hours in rendering medical treatment and institutions and...

Utilization of electronic information resources by academic staff at ...

African Journals Online (AJOL)

The study investigated the utilization of Electronic Information resources by the academic staff of Makerere University in Uganda. It examined the academic staff awareness of the resources available, the types of resources provided by the Makerere University Library, the factors affecting resource utilization. The study was ...

Electronic Resources Management Project Presentation 2012

KAUST Repository

Ramli, Rindra M.

2012-01-01

This presentation describes the electronic resources management project undertaken by the KAUST library. The objectives of this project is to migrate information from MS Sharepoint to Millennium ERM module. One of the advantages of this migration

47 CFR 101.69 - Transition of the 1850-1990 MHz, 2110-2150 MHz, and 2160-2200 MHz bands from the fixed microwave...

Science.gov (United States)

2010-10-01

..., and 2160-2200 MHz bands from the fixed microwave services to personal communications services and...) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Applications and Licenses License Transfers... MHz bands from the fixed microwave services to personal communications services and emerging...

Practical guide to electronic resources in the humanities

CERN Document Server

Dubnjakovic, Ana

2010-01-01

From full-text article databases to digitized collections of primary source materials, newly emerging electronic resources have radically impacted how research in the humanities is conducted and discovered. This book, covering high-quality, up-to-date electronic resources for the humanities, is an easy-to-use annotated guide for the librarian, student, and scholar alike. It covers online databases, indexes, archives, and many other critical tools in key humanities disciplines including philosophy, religion, languages and literature, and performing and visual arts. Succinct overviews of key eme

Utilisation of Electronic Information Resources By Lecturers in ...

African Journals Online (AJOL)

This study assesses the use of information resources, specifically, electronic databases by lecturers/teachers in Universities and Colleges of Education in South Western Nigeria. Information resources are central to teachers' education. It provides lecturers/teachers access to information that enhances research and ...

Comparison of 250 MHz electron spin echo and continuous wave oxygen EPR imaging methods for in vivo applications

Science.gov (United States)

Epel, Boris; Sundramoorthy, Subramanian V.; Barth, Eugene D.; Mailer, Colin; Halpern, Howard J.

2011-01-01

Purpose: The authors compare two electron paramagnetic resonance imaging modalities at 250 MHz to determine advantages and disadvantages of those modalities for in vivo oxygen imaging. Methods: Electron spin echo (ESE) and continuous wave (CW) methodologies were used to obtain three-dimensional images of a narrow linewidth, water soluble, nontoxic oxygen-sensitive trityl molecule OX063 in vitro and in vivo. The authors also examined sequential images obtained from the same animal injected intravenously with trityl spin probe to determine temporal stability of methodologies. Results: A study of phantoms with different oxygen concentrations revealed a threefold advantage of the ESE methodology in terms of reduced imaging time and more precise oxygen resolution for samples with less than 70 torr oxygen partial pressure. Above∼100 torr, CW performed better. The images produced by both methodologies showed pO2 distributions with similar mean values. However, ESE images demonstrated superior performance in low pO2 regions while missing voxels in high pO2 regions. Conclusions: ESE and CW have different areas of applicability. ESE is superior for hypoxia studies in tumors. PMID:21626937

Discipline, availability of electronic resources and the use of Finnish National Electronic Library - FinELib

Directory of Open Access Journals (Sweden)

Sanna Torma

2004-01-01

Full Text Available This study elaborated relations between digital library use by university faculty, users' discipline and the availability of key resources in the Finnish National Electronic Library (FinELib, Finnish national digital library, by using nationwide representative survey data. The results show that the perceived availability of key electronic resources by researchers in FinELib was a stronger predictor of the frequency and purpose of use of its services than users' discipline. Regardless of discipline a good perceived provision of central resources led to a more frequent use of FinELib. The satisfaction with the services did not vary with the discipline, but with the perceived availability of resources.

The Role of the Acquisitions Librarian in Electronic Resources Management

Science.gov (United States)

Pomerantz, Sarah B.

2010-01-01

With the ongoing shift to electronic formats for library resources, acquisitions librarians, like the rest of the profession, must adapt to the rapidly changing landscape of electronic resources by keeping up with trends and mastering new skills related to digital publishing, technology, and licensing. The author sought to know what roles…

Developments and directions in 200 MHz very high power RF at LAMPF

International Nuclear Information System (INIS)

Cliff, R.; Bush, E.D.; DeHaven, R.A.; Harris, H.W.; Parsons, M.

1991-01-01

The Los Alamos Meson Physics Facility (LAMPF), is a linear particle accelerator a half-mile long. It produces an 800 million electron- volt hydrogen-ion beam at an average current of more than one milliamp. The first RF section of the accelerator consists of four Alvarez drift-tube structures. Each of these structures is excited by an amplifier module at a frequency of 201.25 MHz. These amplifiers operate at a duty of 13 percent or more and at peak pulsed power levels of about 2.5 million watts. The second RF accelerator section consists of forty-four side-coupled-cavity structures. Each of these is excited by an amplifier module at a frequency of 805 MHz. These amplifiers operate at a duty of up to 12 percent and at peak pulsed power levels of about 1.2 million watts. The relatively high average beam current in the accelerator places a heavy demand upon components in the RF systems. The 201-MHz modules have always required a large share of maintenance efforts. In recent years, the four 201.25 MHz modules have been responsible for more than twice as much accelerator down-time as have the forty-four 805 MHz modules. This paper reviews recent, ongoing, and planned improvements in the 201-MHz systems. The Burle Industries 7835 super power triode is used in the final power amplifiers of each of the 201-MHz modules. This tube has been modified for operation at LAMPF by the addition of Penning ion vacuum''pumps.'' This has enabled more effective tube conditioning and restarting. A calorimetry system of high accuracy is in development to monitor tube plate-power dissipation

Analysis of Pedagogic Potential of Electronic Educational Resources with Elements of Autodidactics

Directory of Open Access Journals (Sweden)

Igor A.

2018-03-01

Full Text Available Introduction: in recent years didactic properties of electronic educational resources undergo considerable changes, nevertheless, the question of studying of such complete phenomenon as “an electronic educational resource with autodidactics elements” remains open, despite sufficient scientific base of researches of the terms making this concept. Article purpose – determination of essence of electronic educational resources with autodidactics elements. Materials and Methods: the main method of research was the theoretical analysis of the pedagogical and psychological literature on the problem under study. We used the theoretical (analysis, synthesis, comparison and generalization methods, the method of interpretation, pedagogical modeling, and empirical methods (observation, testing, conversation, interview, analysis of students’ performance, pedagogical experiment, peer review. Results: we detected the advantages of electronic educational resources in comparison with traditional ones. The concept of autodidactics as applied to the subject of research is considered. Properties of electronic educational resources with a linear and nonlinear principle of construction are studied.The influence of the principle of construction on the development of the learners’ qualities is shown. We formulated an integral definition of electronic educational resources with elements of autodidactics, namely, the variability, adaptivity and cyclicity of training. A model of the teaching-learning process with electronic educational resources is developed. Discussion and Conclusions: further development of a problem will allow to define whether electronic educational resources with autodidactics elements pedagogical potential for realization of educational and self-educational activity of teachers have, to modify technological procedures taking into account age features of students, their specialties and features of the organization of process of training of

Preservation and conservation of electronic information resources of ...

African Journals Online (AJOL)

The major holdings of the broadcast libraries of the Nigerian Television Authority (NTA) are electronic information resources; therefore, providing safe places for general management of these resources have aroused interest in the industry in Nigeria for sometimes. The need to study the preservation and conservation of ...

Building an electronic resource collection a practical guide

CERN Document Server

Lee, Stuart D

2004-01-01

This practical book guides information professionals step-by-step through building and managing an electronic resource collection. It outlines the range of electronic products currently available in abstracting and indexing, bibliographic, and other services and then describes how to effectively select, evaluate and purchase them.

Analysis of Human Resources Management Strategy in China Electronic Commerce Enterprises

Science.gov (United States)

Shao, Fang

The paper discussed electronic-commerce's influence on enterprise human resources management, proposed and proved the human resources management strategy which electronic commerce enterprise should adopt from recruitment strategy to training strategy, keeping talent strategy and other ways.

Development of 650 MHz (β=0.9) single-cell SCRF cavity

International Nuclear Information System (INIS)

Bagre, M.; Jain, V.; Yedle, A.; Maurya, T.; Yadav, A.; Puntambekar, A.; Goswami, S.G.; Choudhary, R.S.; Sandha, S.; Dwivedi, J.; Kane, G.V.; Mahawar, A.; Mohania, P.; Shrivastava, P.; Sharma, S.; Gupta, R.; Sharma, S.D.; Joshi, S.C.; Mistri, K.K.; Prakash, P.N.

2013-01-01

Raja Ramanna Centre for Advanced Technology has initiated the work on development of Superconducting Radio Frequency (SCRF) cavities and associated technologies as part of R and D activities for upcoming Spallation Neutron Source (SNS) project involving superconducting Linear Accelerator (LINAC). It is planned to use 650 MHz SCRF cavities for the medium and high energy section of the proposed LINAC. Under Indian Institution Fermilab Collaboration (IIFC), Raja Ramanna Centre for Advanced Technology is also working on development of 650 MHz (β=0.9) SCRF cavities proposed to be used in the high energy section of Project-X at FNAL. The work has been initiated with design and development of 650 MHz single cell SCRF cavity. FE analysis was done to estimate change in frequency with temperature as well as to estimate the frequency of the cavity at different cavity manufacturing stages. The development cycle comprises of design and manufacturing of forming tooling, machining, welding and RF measurement fixtures as well as design for manufacturing. The half-cell and beam tubes forming and machining of all parts were done using in-house facilities. The Electron beam welding was carried out at Inter-University Accelerator Centre (IUAC), New Delhi under a MoU. One 650 MHz single cell SCRF cavity has been recently manufactured. In this paper we present the development efforts on manufacturing and pre-qualification of 650 MHz (β=0.9) single cell SCRF cavity. (author)

Using XML Technologies to Organize Electronic Reference Resources

OpenAIRE

Huser, Vojtech; Del Fiol, Guilherme; Rocha, Roberto A.

2005-01-01

Provision of access to reference electronic resources to clinicians is becoming increasingly important. We have created a framework for librarians to manage access to these resources at an enterprise level, rather than at the individual hospital libraries. We describe initial project requirements, implementation details, and some preliminary results.

Electronic Resources and Mission Creep: Reorganizing the Library for the Twenty-First Century

Science.gov (United States)

Stachokas, George

2009-01-01

The position of electronic resources librarian was created to serve as a specialist in the negotiation of license agreements for electronic resources, but mission creep has added more functions to the routine work of electronic resources such as cataloging, gathering information for collection development, and technical support. As electronic…

A 100 MHz synchronized OEIC photoreceiver in n-well, CMOS technology

DEFF Research Database (Denmark)

Kamel, Ayadi; Danielsen, Per Lander

1998-01-01

We analyze and demonstrate a synchronized CMOS photoreceiver for the conversion of optical inputs of pulse-light to electronic digital signals. Small-signal and photonic analysis of the proposed circuit are detailed. The photoreceiver was operated at 100 MHz with only 13.3 fJ/pulse of 830-nm inpu...

The 938 MHz resonant damping loops for the 200 MHz SPS travelling wave cavities

CERN Document Server

Caspers, F

2012-01-01

Measurements of the beam stability in the SPS in 1982 - 1983 have shown a transversal instability for high intensity beams [1]. The fact that this related technical note is published nearly 30 years later, is related to the revival of interest in the frame of SPS impedance evaluation for LS1. Until now there was just a barely known paper folder available which could be consulted on request. The instability mentioned above was identified from beam measurements as raised by a deflecting mode at approximately 940 MHz in the 200 MHz travelling wave cavities of the SPS. Estimates showed that an attenuation of this particular mode by 20 dB would be desirable. In order to achieve this attenuation some vacuum ports on top of the cavities were available. For the damping devices three requirements had to be met: - sufficient damping at about 940 MHz - no serious change of cavity input VSWR at 200 MHz - no water cooling requirement for this higher order mode coupler.

Electronic Resources Management System: Recommendation Report 2017

KAUST Repository

Ramli, Rindra M.

2017-01-01

This recommendation report provides an overview of the selection process for the new Electronic Resources Management System. The library has decided to move away from Innovative Interfaces Millennium ERM module. The library reviewed 3 system

The Internet School of Medicine: use of electronic resources by medical trainees and the reliability of those resources.

Science.gov (United States)

Egle, Jonathan P; Smeenge, David M; Kassem, Kamal M; Mittal, Vijay K

2015-01-01

Electronic sources of medical information are plentiful, and numerous studies have demonstrated the use of the Internet by patients and the variable reliability of these sources. Studies have investigated neither the use of web-based resources by residents, nor the reliability of the information available on these websites. A web-based survey was distributed to surgical residents in Michigan and third- and fourth-year medical students at an American allopathic and osteopathic medical school and a Caribbean allopathic school regarding their preferred sources of medical information in various situations. A set of 254 queries simulating those faced by medical trainees on rounds, on a written examination, or during patient care was developed. The top 5 electronic resources cited by the trainees were evaluated for their ability to answer these questions accurately, using standard textbooks as the point of reference. The respondents reported a wide variety of overall preferred resources. Most of the 73 responding medical trainees favored textbooks or board review books for prolonged studying, but electronic resources are frequently used for quick studying, clinical decision-making questions, and medication queries. The most commonly used electronic resources were UpToDate, Google, Medscape, Wikipedia, and Epocrates. UpToDate and Epocrates had the highest percentage of correct answers (47%) and Wikipedia had the lowest (26%). Epocrates also had the highest percentage of wrong answers (30%), whereas Google had the lowest percentage (18%). All resources had a significant number of questions that they were unable to answer. Though hardcopy books have not been completely replaced by electronic resources, more than half of medical students and nearly half of residents prefer web-based sources of information. For quick questions and studying, both groups prefer Internet sources. However, the most commonly used electronic resources fail to answer clinical queries more than half

Imaging melanin cancer growth in-vivo using raster-scan optoacoustic mesoscopy (RSOM) at 50 MHz and 100 MHz

Science.gov (United States)

Omar, Murad; Schwarz, Mathias; Soliman, Dominik; Symvoulidis, Panagiotis; Ntziachristos, Vasilis

2016-03-01

We used raster-scan optoacoustic mesoscopy (RSOM) at 50 MHz, and at 100 MHz, to monitor tumor growth, and tumor angiogenesis, which is a central hallmark of cancer, in-vivo. In this study we compared the performance, and the effect of the 50 MHz, and the 100 MHz frequencies on the quality of the final image. The system is based on a reflection-mode implementation of RSOM. The detectors used are custom made, ultrawideband, and spherically focused. The use of such detectors enables light coupling from the same side as the detector, thus reflection-mode. Light is in turn coupled using a fiber bundle, and the detector is raster scanned in the xy-plane. Subsequently, to retrieve small features, the raw data are reconstructed using a multi-bandwidth, beamforming reconstruction algorithm. Comparison of the system performance at the different frequencies shows as expected a higher resolution in case of the 100 MHz detector compared to the 50 MHz. On the other hand the 50 MHz has a better SNR, can detect features from deeper layers, and has higher angular acceptance. Based on these characteristics the 50 MHz detector was mostly used. After comparing the performance we monitored the growth of B16F10 cells, melanin tumor, over the course of 9 days. We see correspondence between the optoacoustic measurements and the cryoslice validations. Additionally, in areas close to the tumor we see sprouting of new vessels, starting at day 4-5, which corresponds to tumor angiogenesis.

The 136 MHZ/400 MHz earth station antenna-noise temperature prediction program for RAE-B

Science.gov (United States)

Taylor, R. E.; Fee, J. J.; Chin, M.

1972-01-01

A simulation study was undertaken to determine the 136 MHz and 400 MHz noise temperature of the ground network antennas which will track the RAE-B satellite during data transmission periods. Since the noise temperature of the antenna effectively sets the signal-to-noise ratio of the received signal, a knowledge of SNR will be helpful in locating the optimum time windows for data transmission during low noise periods. Antenna noise temperatures will be predicted for selected earth-based ground stations which will support RAE-B. Telemetry data acquisition will be at 400 MHz; tracking support at 136 MHz will be provided by the Goddard Range and Range Rate (RARR) stations. The antenna-noise temperature predictions will include the effects of galactic-brightness temperature, the sun, and the brightest radio stars. Predictions will cover the ten-month period from March 1, 1973 to December 31, 1973.

ANALYTICAL REVIEW OF ELECTRONIC RESOURCES FOR THE STUDY OF LATIN

Directory of Open Access Journals (Sweden)

Olena Yu. Balalaieva

2014-04-01

Full Text Available The article investigates the current state of development of e-learning content in the Latin language. It is noted that the introduction of ICT in the educational space has expanded the possibility of studying Latin, opened access to digital libraries resources, made it possible to use scientific and educational potential and teaching Latin best practices of world's leading universities. A review of foreign and Ukrainian information resources and electronic editions for the study of Latin is given. Much attention was paid to the didactic potential of local and online multimedia courses of Latin, electronic textbooks, workbooks of interactive tests and exercises, various dictionaries and software translators, databases and digital libraries. Based on analysis of the world market of educational services and products the main trends in the development of information resources and electronic books are examined. It was found that multimedia courses with interactive exercises or workbooks with interactive tests, online dictionaries and translators are the most widely represented and demanded. The noticeable lagging of Ukrainian education and computer linguistics in quantitative and qualitative measures in this industry is established. The obvious drawback of existing Ukrainian resources and electronic editions for the study of Latin is their noninteractive nature. The prospects of e-learning content in Latin in Ukraine are outlined.

Elektronik Bilgi Kaynaklarının Seçimi / Selection of Electronic Information Resources

Directory of Open Access Journals (Sweden)

Pınar Al

2003-04-01

Full Text Available For many years, library users have used only from the printed media in order to get the information that they have needed. Today with the widespread use of the Web and the addition of electronic information resources to library collections, the use of information in the electronic environment as well as in printed media is started to be used. In time, such types of information resources as, electronic journals, electronic books, electronic encyclopedias, electronic dictionaries and electronic theses have been added to library collections. In this study, selection criteria that can be used for electronic information resources are discussed and suggestions are provided for libraries that try to select electronic information resources for their collections.

47 CFR 90.672 - Unacceptable interference to non-cellular 800 MHz licensees from 800 MHz cellular systems or part...

Science.gov (United States)

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Unacceptable interference to non-cellular 800 MHz licensees from 800 MHz cellular systems or part 22 Cellular Radiotelephone systems, and within the... Procedures and Process-Unacceptable Interference § 90.672 Unacceptable interference to non-cellular 800 MHz...

Access to electronic resources by visually impaired people

Directory of Open Access Journals (Sweden)

Jenny Craven

2003-01-01

Full Text Available Research into access to electronic resources by visually impaired people undertaken by the Centre for Research in Library and Information Management has not only explored the accessibility of websites and levels of awareness in providing websites that adhere to design for all principles, but has sought to enhance understanding of information seeking behaviour of blind and visually impaired people when using digital resources.

500 MHz narrowband beam position monitor electronics for electron synchrotrons

International Nuclear Information System (INIS)

Mohos, I.; Dietrich, J.

1998-01-01

Narrowband beam position monitor electronics were developed in the Forschungszentrum Juelich-IKP for the orbit measurement equipment used at ELSA Bonn. The equipment uses 32 monitor chambers, each with four capacitive button electrodes. The monitor electronics, consisting of an rf signal processing module (BPM-RF) and a data acquisition and control module (BPM-DAQ), sequentially process and measure the monitor signals and deliver calculated horizontal and vertical beam position data via a serial network

500 MHz narrowband beam position monitor electronics for electron synchrotrons

Science.gov (United States)

Mohos, I.; Dietrich, J.

1998-12-01

Narrowband beam position monitor electronics were developed in the Forschungszentrum Jülich-IKP for the orbit measurement equipment used at ELSA Bonn. The equipment uses 32 monitor chambers, each with four capacitive button electrodes. The monitor electronics, consisting of an rf signal processing module (BPM-RF) and a data acquisition and control module (BPM-DAQ), sequentially process and measure the monitor signals and deliver calculated horizontal and vertical beam position data via a serial network.

Design of 1 MHz solid state high frequency power supply

International Nuclear Information System (INIS)

Parmar, Darshan Kumar; Singh, N.P.; Gajjar, Sandip

2015-01-01

A High Voltage High Frequency (HVHF) Power supply is used for various applications, like AM Transmitters, metallurgical applications, Wireless Power Transfer, RF Ion Sources, etc. The Ion Source for a Neutral beam Injector at ITER-India uses inductively coupled power source at High Frequency (∼ 1 MHz). Switching converter based topology used to generate 1 MHz sinusoidal output is expected to have advantages on efficiency and reliability as compared to traditional RF Tetrode tubes based oscillators. In terms of Power Electronics, thermal and power coupling issues are major challenges at such a high frequency. A conceptual design for a 200 kW, 1 MHz power supply and a prototype design for a 600W source been done. The prototype design is attempted with Class-E amplifier topology where a MOSFET is switched resonantly. The prototype uses two low power modules and a ferrite combiner to add the voltage and power at the output. Subsequently solution with class-D H-Bridge configuration have been evaluated through simulation where module design is stable as switching device do not participate in resonance, further switching device voltage rating is substantially reduced. The rating of the modules is essentially driven by the maximum power handling capacity of the MOSFETs and ferrites in the combiner circuit. The output passive network including resonance tuned network and impedance matching network caters for soft switching and matches the load impedance to 50 ohm respectively. This paper describes the conceptual design of a 200 kW power supply and experimental results of the prototype 600 W, 1 MHz source. (author)

Design of 1 MHz Solid State High Frequency Power Supply

Science.gov (United States)

Parmar, Darshan; Singh, N. P.; Gajjar, Sandip; Thakar, Aruna; Patel, Amit; Raval, Bhavin; Dhola, Hitesh; Dave, Rasesh; Upadhay, Dishang; Gupta, Vikrant; Goswami, Niranjan; Mehta, Kush; Baruah, Ujjwal

2017-04-01

High Frequency Power supply (HFPS) is used for various applications like AM Transmitters, metallurgical applications, Wireless Power Transfer, RF Ion Sources etc. The Ion Source for a Neutral beam Injector at ITER-India uses inductively coupled power source at High Frequency (∼1 MHz). Switching converter based topology used to generate 1 MHz sinusoidal output is expected to have advantages on efficiency and reliability as compared to traditional RF Tetrode tubes based oscillators. In terms of Power Electronics, thermal and power coupling issues are major challenges at such a high frequency. A conceptual design for a 200 kW, 1 MHz power supply and a prototype design for a 600 W source been done. The prototype design is attempted with Class-E amplifier topology where a MOSFET is switched resonantly. The prototype uses two low power modules and a ferrite combiner to add the voltage and power at the output. Subsequently solution with Class-D H-Bridge configuration have been evaluated through simulation where module design is stable as switching device do not participate in resonance, further switching device voltage rating is substantially reduced. The rating of the modules is essentially driven by the maximum power handling capacity of the MOSFETs and ferrites in the combiner circuit. The output passive network including resonance tuned network and impedance matching network caters for soft switching and matches the load impedance to 50ohm respectively. This paper describes the conceptual design of a 200 kW high frequency power supply and experimental results of the prototype 600 W, 1 MHz source.

Library training to promote electronic resource usage

DEFF Research Database (Denmark)

Frandsen, Tove Faber; Tibyampansha, Dativa; Ibrahim, Glory

2017-01-01

Purpose: Increasing the usage of electronic resources is an issue of concern for many libraries all over the world. Several studies stress the importance of information literacy and instruction in order to increase the usage. Design/methodology/approach: The present article presents the results...

Why and How to Measure the Use of Electronic Resources

Directory of Open Access Journals (Sweden)

Jean Bernon

2008-11-01

Full Text Available A complete overview of library activity implies a complete and reliable measurement of the use of both electronic resources and printed materials. This measurement is based on three sets of definitions: document types, use types and user types. There is a common model of definitions for printed materials, but a lot of questions and technical issues remain for electronic resources. In 2006 a French national working group studied these questions. It relied on the COUNTER standard, but found it insufficient and pointed out the need for local tools such as web markers and deep analysis of proxy logs. Within the French national consortium COUPERIN, a new working group is testing ERMS, SUSHI standards, Shibboleth authentication, along with COUNTER standards, to improve the counting of the electronic resources use. At this stage this counting is insufficient and its improvement will be a European challenge for the future.

The 136 MHz/400 MHz earth station antenna-noise temperature prediction program documentation for RAE-B

Science.gov (United States)

Chin, M.

1972-01-01

A simulation study to determine the 136 MHz and 400 MHz noise temperature of the ground network antennas which will track the RAE-B satellite during data transmission periods is described. Since the noise temperature of the antenna effectively sets the signal-to-noise ratio (SNR) of the received signal, a knowledge of SNR will be helpful in locating the optimum time windows for data transmission during low-noise periods. Antenna-noise temperatures at 136 MHz and 400 MHz will be predicted for selected earth-based ground stations which will support RAE-B. The antenna-noise temperature predictions will include the effects of galactic-brightness temperature, the sun, and the brightest radio stars. Predictions will cover the ten-month period from March 1, 1973 to December 31, 1973. The RAE-B mission will be expecially susceptible to SNR degradation during the two eclipses of the Sun occurring in this period.

Electromagnetic Radiation Originating from Unstable Electron Oscillations

DEFF Research Database (Denmark)

Juul Rasmussen, Jens; Pécseli, Hans

1975-01-01

Electromagnetic oscillations in the range 300 – 700 MHz were observed from an unmagnetized argon discharge with an unstable electron velocity distribution function.......Electromagnetic oscillations in the range 300 – 700 MHz were observed from an unmagnetized argon discharge with an unstable electron velocity distribution function....

Euler European Libraries and Electronic Resources in Mathematical Sciences

CERN Document Server

The Euler Project. Karlsruhe

The European Libraries and Electronic Resources (EULER) Project in Mathematical Sciences provides the EulerService site for searching out "mathematical resources such as books, pre-prints, web-pages, abstracts, proceedings, serials, technical reports preprints) and NetLab (for Internet resources), this outstanding engine is capable of simple, full, and refined searches. It also offers a browse option, which responds to entries in the author, keyword, and title fields. Further information about the Project is provided at the EULER homepage.

Effects of Electronic Information Resources Skills Training for Lecturers on Pedagogical Practices and Research Productivity

Science.gov (United States)

Bhukuvhani, Crispen; Chiparausha, Blessing; Zuvalinyenga, Dorcas

2012-01-01

Lecturers use various electronic resources at different frequencies. The university library's information literacy skills workshops and seminars are the main sources of knowledge of accessing electronic resources. The use of electronic resources can be said to have positively affected lecturers' pedagogical practices and their work in general. The…

Dynamics and performance of the free electron laser at Super-Aco with a harmonic RF cavity set on 500 MHz

International Nuclear Information System (INIS)

Nutarelli, D.

2000-01-01

This work is dedicated to the development of the potentialities of the free electron laser that has been installed on the storage ring Super-Aco at Orsay university. We have studied the dynamics of the electron beam inside a harmonic RF cavity set on 500 MHz. The impact of the geometric characteristics of the optical cavity on the transverse overlapping between laser radiation and the electron beam has been studied in details. An important part of the work has been the assessment of the optical characterization of the dielectric multi-layer mirrors of the cavity. For that purpose a complete system has been designed to assess the changes in optical properties of mirrors during laser operation. Another important part of this work was the study of the interaction process between laser radiation and the electron bunch leading to saturation. This interaction process has been simulated through a new model and some predictions given by this model have been successfully confronted to experimental data. The installation of the harmonic RF cavity has led to a significant increase of the laser radiation gain and the value of the mean power of the laser radiation has reached 300 mW. An interesting application of this technique is the generation of high energy gamma photons through Compton backscattering. A collimated 35 MeV-energy photon beam has been produced at Super-Aco with a rate of 5.10 6 photons per second. (A.C.)

Electron gun for the Fel Clio

International Nuclear Information System (INIS)

Chaput, R.

1990-01-01

A triode electron gun has been developed and manufactured at LURE (Laboratoire pour l'Utilisation du Rayonnement Electromagnetique) and LAL (Laboratoire de l'Accelerateur Lineaire) for the free electron laser CLIO 1 (Collaboration pour un laser a electrons libres dans l'infrarouge a Orsay) now under construction: this gun involves a grid-cathode assembly manufactured by EIMAC, currently used in the SLAC gun family. For the FEL requirements, the gun must be able to yield a train of short pulses at accuracy frequency or a continuous pulse. Driving together the cathode and the grid the gun produces a continous beam of 12 μs or a pulsed beam of very short pulse of 1 ns at 250 MHz, 125 MHz, 62.5 MHz or 31.25 MHz. The performances of the gun has been tested on a testing bench. A peak current of 1 Amp. for 1 ns width at any frequencies was achieved at an injection voltage of 90 kV

Electronic Commerce Resource Centers. An Industry--University Partnership.

Science.gov (United States)

Gulledge, Thomas R.; Sommer, Rainer; Tarimcilar, M. Murat

1999-01-01

Electronic Commerce Resource Centers focus on transferring emerging technologies to small businesses through university/industry partnerships. Successful implementation hinges on a strategic operating plan, creation of measurable value for customers, investment in customer-targeted training, and measurement of performance outputs. (SK)

New Control Structure of the 200 MHz RF System in the CERN PS

CERN Document Server

Damerau, H; CERN. Geneva. AB Department

2008-01-01

The 200 MHz RF system is an essential tool for the preparation of high-intensity beams in the CERN PS. Presently, six RF cavities are operated to control the longitudinal bunch emittance and rebunching of the beam before the transfer to the SPS. Cavities are selected for the various processes with a dedicated hardware matrix, switching the individual timing pulses and voltage programs per cavity. However, the electronics used for the matrix hardware is obsolete and its reliability cannot be guaranteed due to a lack of spare modules and components. Instead of replacing the old hardware matrix by modern hardware, this note describes a new control structure for the 200MHz RF system so that no dedicated hardware will be required anymore. The implementation of the new control structure is based on two main concepts. Firstly, linked timing trees per blow-up or rebunching are used to handle all related timing and to store one row of the matrix. Secondly, as a reflection of the RF signal generation for the 200 MHz sy...

Field profile and loading measurements on higher order modes in a two cell 500 MHz superconducting structure

International Nuclear Information System (INIS)

Barry, W.; Edighoffer, J.; Chattopadhyay, S.; Fornaca, S.

1992-08-01

The Infrared Free Electron Laser, being designed at LBL as part of the Chemical Dynamics Research Laboratory, is based on a 500 MHz superconducting linac driver that consists of five 4-cell structures of the CERN/DESY type. A 500 MHz, 2-cell version of this structure is being used in a joint Stanford/LBL/BNL program to study accelerator issues relevant to the FEL applications. As part of this study, field profile and loading measurements of higher order modes have been made on the prototype structure

A 70 MHz pulsing beam system for protons

International Nuclear Information System (INIS)

An Shizhong; Zhang Tianjue; Wu Longcheng; Lv Yinlong; Song Guofang; Guan Fengping; Jia Xianlu

2008-01-01

A test beam line for pulsed beam generation for 10 MeV central region model (CRM) of a compact cyclotron is under construction as China Institute of Atomic Energy (CIAE). A 70 MHz continuous H - beam with the energy of dozens of keV or a hundred keV will be pulsed to pulse length of less than 10 ns with the repetition rate of 1-8 MHz. A 70.487 MHz buncher will be used to compress the DC beam into the RF phase acceptance of ±30° of the CRM cyclotron. The 2.2 MHz sine waveform will be used for the chopper. A pulse with the repetition rate to 4.4 MHz and pulse length less than 10 ns is expected after CRM cyclotron. (authors)

BLAZAR SPECTRAL PROPERTIES AT 74 MHz

Energy Technology Data Exchange (ETDEWEB)

Massaro, F.; Funk, S. [SLAC National Laboratory and Kavli Institute for Particle Astrophysics and Cosmology, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States); Giroletti, M. [INAF Istituto di Radioastronomia, via Gobetti 101, I-40129 Bologna (Italy); Paggi, A.; D' Abrusco, R. [Harvard-Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA 02138 (United States); Tosti, G. [Dipartimento di Fisica, Università degli Studi di Perugia, I-06123 Perugia (Italy)

2013-10-01

Blazars are the most extreme class of active galactic nuclei. Despite a previous investigation at 102 MHz for a small sample of BL Lac objects and our recent analysis of blazars detected in the Westerbork Northern Sky Survey, a systematic study of the blazar spectral properties at frequencies below 100 MHz has been never carried out. In this paper, we present the first analysis of the radio spectral behavior of blazars based on the recent Very Large Array Low-frequency Sky Survey (VLSS) at 74 MHz. We search for blazar counterparts in the VLSS catalog, confirming that they are detected at 74 MHz. We then show that blazars present radio-flat spectra (i.e., radio spectral indices of ∼0.5) when evaluated, which also about an order of magnitude in frequency lower than previous analyses. Finally, we discuss the implications of our findings in the context of the blazars-radio galaxies connection since the low-frequency radio data provide a new diagnostic tool to verify the expectations of the unification scenario for radio-loud active galaxies.

Field profile and loading measurements on higher order modes in a two cell 500 MHz superconducting structure

International Nuclear Information System (INIS)

Barry, W.; Edighoffer, J.; Chattopadhyay, S.; Fornaco, S.

1992-01-01

The Infrared Free Electron Laser, being designed at LBL as part of the Chemical Dynamics Research Laboratory, is based on a 500 MHz superconducting linac driver that consists of five 4-cell structures of the CERN/DESY type. A 500 MHz, 2-cell version of this structure is being used in a joint Stanford/LBL/BNL program to study accelerator issues relevant to the FEL applications. As part of this study, field profile and loading measurements of higher order modes have been made on the prototype structure. (Author) 3 refs., 2 figs., tab

47 CFR 101.82 - Reimbursement and relocation expenses in the 2110-2150 MHz and 2160-2200 MHz bands.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Reimbursement and relocation expenses in the... License Transfers, Modifications, Conditions and Forfeitures § 101.82 Reimbursement and relocation expenses in the 2110-2150 MHz and 2160-2200 MHz bands. (a) Reimbursement and relocation expenses for the...

Inversion of the OH 1720-MHz line

International Nuclear Information System (INIS)

Elitzur, M.

1975-01-01

It is shown that the OH 1720-MHz line can be strongly inverted by collisions which excite the rotation states. It is also argued that radiative pumps (of any wave length) can invert strongly only the 1612-MHz line. (author)

Providing primary standard calibrations beyond 20 MHz

International Nuclear Information System (INIS)

Bickley, C J; Zeqiri, B; Robinson, S P

2004-01-01

The number of applications of medical ultrasound utilising frequencies in excess of 20 MHz has shown a consistent increase over recent years. Coupled with the commercial availability of wide-bandwidth hydrophones whose response extends beyond 40 MHz, this has driven a growing need to develop hydrophone calibration techniques at elevated frequencies. The current National Physical Laboratory primary standard method of calibrating hydrophones is based on an optical interferometer. This has been in operation for around 20 years and provides traceability over the frequency range of 0.3 to 20 MHz. More recently, calibrations carried out using the interferometer have been extended to 60 MHz, although the uncertainties associated with these calibrations are poor, being in excess of ±20% at high frequencies. Major contributions to the degraded calibration uncertainties arise from poor signal-to-noise at higher frequencies, the frequency response of the photodiodes used and the noise floor of the instrument. To improve the uncertainty of hydrophone calibrations above 20 MHz, it has been necessary to build and commission a new interferometer. Important features of the new primary standard are its use of a higher power laser to improve the signal-to-noise ratio, along with photodiodes whose greater bandwidth to improve the overall frequency response. This paper describes the design of key aspects of the new interferometer. It also presents some initial results of the performance assessment, including a detailed comparison of calibrations of NPL reference membrane hydrophones, undertaken using old and new interferometers for calibration up to 40 MHz

Mechanical design and fabrication of a 425-MHz H- buncher

International Nuclear Information System (INIS)

Wilson, N.G.; Precechtel, D.

1987-01-01

A beam buncher has been designed, fabricated, and installed on the accelerator test stand (ATS) to match the 2-MeV output beam of a 425-MHz H - radio-frequency quadrupole (RFQ) into a 425-MHz drift-tube linac (DTL). The buncher configuration provides integral-matching permanent-magnet quadrupoles (PMQ) at the exit of the RFQ and one βλ across the buncher accelerating gap; a third PMQ is the first DTL half-cell magnet. Located between the second and third PMQs is a 50-Ω, capacitively coupled, beam-sensing pickup loop. Cooling channels are provided in each of the brazed OFHC copper wall sections. Vacuum pumping of the buncher is provided by a cryogenic refrigerator vacuum pump through an array of small-diameter holes in the buncher cavity wall. Mechanical features of the buncher, the brazing and electron-beam welding of the solid-copper buncher structure, and the beam pickup loop are described in this paper. The buncher has been tuned, installed, and operated at full power on the ATS

77 FR 22720 - Service Rules for Advanced Wireless Services in the 2000-2020 MHz and 2180-2200 MHz Bands, etc.

Science.gov (United States)

2012-04-17

... operations in 1930-1995 MHz and uplink operations in 2000-2020 MHz. To address this apparent tension, we seek... includes broadcast auxiliary service (BAS) and cable television service (CARS) operations, as well as...

BNL 56 MHz HOM Damper Prototype Fabrication at JLab

Energy Technology Data Exchange (ETDEWEB)

Huque, Naeem A. [Jefferson Lab., Newport News, VA (United States); Daly, Edward F. [Jefferson Lab., Newport News, VA (United States); Clemens, William A. [Jefferson Lab., Newport News, VA (United States); McIntyre, Gary T. [Brookhaven National Lab. (BNL), Upton, NY (United States); Wu, Qiong [Brookhaven National Lab. (BNL), Upton, NY (United States); Seberg, Scott [Brookhaven National Lab. (BNL), Upton, NY (United States); Bellavia, Steve [Brookhaven National Lab. (BNL), Upton, NY (United States)

2015-09-01

A prototype Higher-Order Mode (HOM) Damper was fabricated at JLab for the Relativistic Heavy-Ion Collider's (RHIC) 56 MHz cavity at Brookhaven National Laboratory (BNL). Primarily constructed from high RRR Niobium and Sapphire, the coaxial damper presented significant challenges in electron-beam welding (EBW), brazing and machining via acid etching. The results of the prototype operation brought about changes in the damper design, due to overheating braze alloys and possible multi-pacting. Five production HOM dampers are currently being fabricated at JLab. This paper outlines the challenges faced in the fabrication process, and the solutions put in place.

Electron Cooling of RHIC

CERN Document Server

Ben-Zvi, Ilan; Barton, Donald; Beavis, Dana; Blaskiewicz, Michael; Bluem, Hans; Brennan, Joseph M; Bruhwiler, David L; Burger, Al; Burov, Alexey; Burrill, Andrew; Calaga, Rama; Cameron, Peter; Chang, Xiangyun; Cole, Michael; Connolly, Roger; Delayen, Jean R; Derbenev, Yaroslav S; Eidelman, Yury I; Favale, Anthony; Fedotov, Alexei V; Fischer, Wolfram; Funk, L W; Gassner, David M; Hahn, Harald; Harrison, Michael; Hershcovitch, Ady; Holmes, Douglas; Hseuh Hsiao Chaun; Johnson, Peter; Kayran, Dmitry; Kewisch, Jorg; Kneisel, Peter; Koop, Ivan; Lambiase, Robert; Litvinenko, Vladimir N; MacKay, William W; Mahler, George; Malitsky, Nikolay; McIntyre, Gary; Meng, Wuzheng; Merminga, Lia; Meshkov, Igor; Mirabella, Kerry; Montag, Christoph; Nagaitsev, Sergei; Nehring, Thomas; Nicoletti, Tony; Oerter, Brian; Parkhomchuk, Vasily; Parzen, George; Pate, David; Phillips, Larry; Preble, Joseph P; Rank, Jim; Rao, Triveni; Rathke, John; Roser, Thomas; Russo, Thomas; Scaduto, Joseph; Schultheiss, Tom; Sekutowicz, Jacek; Shatunov, Yuri; Sidorin, Anatoly O; Skrinsky, Aleksander Nikolayevich; Smirnov, Alexander V; Smith, Kevin T; Todd, Alan M M; Trbojevic, Dejan; Troubnikov, Grigory; Wang, Gang; Wei, Jie; Williams, Neville; Wu, Kuo-Chen; Yakimenko, Vitaly; Zaltsman, Alex; Zhao, Yongxiang; ain, Animesh K

2005-01-01

We report progress on the R&D program for electron-cooling of the Relativistic Heavy Ion Collider (RHIC). This electron cooler is designed to cool 100 GeV/nucleon at storage energy using 54 MeV electrons. The electron source will be a superconducting RF photocathode gun. The accelerator will be a superconducting energy recovery linac. The frequency of the accelerator is set at 703.75 MHz. The maximum electron bunch frequency is 9.38 MHz, with bunch charge of 20 nC. The R&D program has the following components: The photoinjector and its photocathode, the superconducting linac cavity, start-to-end beam dynamics with magnetized electrons, electron cooling calculations including benchmarking experiments and development of a large superconducting solenoid. The photoinjector and linac cavity are being incorporated into an energy recovery linac aimed at demonstrating ampere class current at about 20 MeV. A Zeroth Order Design Report is in an advanced draft state, and can be found on the web at http://www.ags...

BNL 703 MHz SRF cryomodule demonstration

International Nuclear Information System (INIS)

Burrill, A.; Ben-Zvi, I.; Calaga, R.; Dalesio, L.; Dottavio, T.; Gassner, D.; Hahn, H.; Hoff, L.; Kayran, D.; Kewisch, J.; Lambiase, R.; Lederle, D.; Litvinenko, V.; Mahler, G.; McIntyre, G.

2009-01-01

This paper will present the preliminary results of the testing of the 703 MHz SRF cryomodule designed for use in the ampere class ERL under construction at Brookhaven National Laboratory. The preliminary cavity tests, carried out at Thomas Jefferson Laboratory, demonstrated cavity performance of 20 MV/m with a Qo of 1 x 10 10 , results we expect to reproduce in the horizontal configuration. This test of the entire string assembly will allow us to evaluate all of the additional cryomodule components not previously tested in the VTA and will prepare us for our next milestone test which will be delivery of electrons from our injector through the cryomodule to the beam dump. This will also be the first demonstration of an accelerating cavity designed for use in an ampere class ERL, a key development which holds great promise for future machines

USE OF ELECTRONIC EDUCATIONAL RESOURCES WHEN TRAINING IN WORK WITH SPREADSHEETS

Directory of Open Access Journals (Sweden)

Х А Гербеков

2017-12-01

Full Text Available Today the tools for maintaining training courses based on opportunities of information and communication technologies are developed. Practically in all directions of preparation and on all subject matters electronic textbook and self-instruction manuals are created. Nevertheless the industry of computer educational and methodical materials actively develops and gets more and more areas of development and introduction. In this regard more and more urgent is a problem of development of the electronic educational resources adequate to modern educational requirements. Creation and the organization of training courses with use of electronic educational resources in particular on the basis of Internet technologies remains a difficult methodical task.In article the questions connected with development of electronic educational resources for use when studying the substantial line “Information technologies” of a school course of informatics in particular for studying of spreadsheets are considered. Also the analysis of maintenance of a school course and the unified state examination from the point of view of representation of task in him corresponding to the substantial line of studying “Information technologies” on mastering technology of information processing in spreadsheets and the methods of visualization given by means of charts and schedules is carried out.

47 CFR 90.355 - LMS operations below 512 MHz.

Science.gov (United States)

2010-10-01

... PRIVATE LAND MOBILE RADIO SERVICES Intelligent Transportation Systems Radio Service § 90.355 LMS... LMS station and the nearest co-channel base station of another licensee operating a voice system is 75... MHz, 150-170 MHz, and 450-512 MHz bands may use either base-mobile frequencies currently assigned the...

Development of A 402.5 MHz 140 kW Inductive Output Tube

International Nuclear Information System (INIS)

Ives, R. Lawrence; Read, Michael; Jackson, Robert

2012-01-01

This report contains the results of Phase I of an SBIR to develop a Pulsed Inductive Output Tube (IOT) with 140 kW at 400 MHz for powering H-proton beams. A number of sources, including single beam and multiple beam klystrons, can provide this power, but the IOT provides higher efficiency. Efficiencies exceeding 70% are routinely achieved. The gain is typically limited to approximately 24 dB; however, the availability of highly efficient, solid state drivers reduces the significance of this limitation, particularly at lower frequencies. This program initially focused on developing a 402 MHz IOT; however, the DOE requirement for this device was terminated during the program. The SBIR effort was refocused on improving the IOT design codes to more accurately simulate the time dependent behavior of the input cavity, electron gun, output cavity, and collector. Significant improvement was achieved in modeling capability and simulation accuracy.

High-power circulator test results at 350 and 700 MHz

International Nuclear Information System (INIS)

Roybal, W.; Bradley, J.T.; Rees, D.E.

2000-01-01

The high-power RF systems for the Accelerator Production of Tritium (APT) program require high-power circulators at 350 MHz and 700 MHz to protect 1 MW Continuous Wave (CW) klystrons from reflected power. The 350 MHz circulator is based on the CERN, EXF, and APS designs and has performed very well. The 700 MHz circulator is a new design. Prototype 700 MHz circulators have been high-power tested at Los Alamos National Laboratory (LANL). The first of these circulators has satisfied performance requirements. The circulator requirements, results from the testing, and lessons learned from this development are presented and discussed

Commissioning of the 400 MHz LHC RF System

CERN Document Server

Ciapala, Edmond; Baudrenghien, P; Brunner, O; Butterworth, A; Linnecar, T; Maesen, P; Molendijk, J; Montesinos, E; Valuch, D; Weierud, F

2008-01-01

The installation of the 400 MHz superconducting RF system in LHC is finished and commissioning is under way. The final RF system comprises four cryo-modules each with four cavities in the LHC tunnel straight section round IP4. Also underground in an adjacent cavern shielded from the main tunnel are the sixteen 300 kW klystron RF power sources with their high voltage bunkers, two Faraday cages containing RF feedback and beam control electronics, and racks containing all the slow controls. The system and the experience gained during commissioning will be described. In particular, results from conditioning the cavities and their movable main power couplers and the setting up of the low level RF feedbacks will be presented.

Analytical Study of Usage of Electronic Information Resources at Pharmacopoeial Libraries in India

Directory of Open Access Journals (Sweden)

Sunil Tyagi

2014-02-01

Full Text Available The objective of this study is to know the rate and purpose of the use of e-resource by the scientists at pharmacopoeial libraries in India. Among other things, this study examined the preferences of the scientists toward printed books and journals, electronic information resources, and pattern of using e-resources. Non-probability sampling specially accidental and purposive technique was applied in the collection of primary data through administration of user questionnaire. The sample respondents chosen for the study consists of principle scientific officer, senior scientific officer, scientific officer, and scientific assistant of different division of the laboratories, namely, research and development, pharmaceutical chemistry, pharmacovigilance, pharmacology, pharmacogonosy, and microbiology. The findings of the study reveal the personal experiences and perceptions they have had on practice and research activity using e-resource. The major findings indicate that of the total anticipated participants, 78% indicated that they perceived the ability to use computer for electronic information resources. The data analysis shows that all the scientists belonging to the pharmacopoeial libraries used electronic information resources to address issues relating to drug indexes and compendia, monographs, drugs obtained through online databases, e-journals, and the Internet sources—especially polices by regulatory agencies, contacts, drug promotional literature, and standards.

Page 170 Use of Electronic Resources by Undergraduates in Two ...

African Journals Online (AJOL)

undergraduate students use electronic resources such as NUC virtual library, HINARI, ... web pages articles from magazines, encyclopedias, pamphlets and other .... of Nigerian university libraries have Internet connectivity, some of the system.

Limits on fast radio bursts at 145 MHz with ARTEMIS, a real-time software backend

NARCIS (Netherlands)

Karastergiou, A.; Chennamangalam, J.; Armour, W.; Williams, C.; Mort, B.; Dulwich, F.; Salvini, S.; Magro, A.; Roberts, S.; Serylak, M.; Doo, A.; Bilous, A.V.; Breton, R.P.; Falcke, H.; Grießmeier, J.M.; Hessels, J.W.T.; Keane, E.F.; Kondratiev, V.I.; Kramer, M.; van Leeuwen, J.; Noutsos, A.; Osłowski, S.; Sobey, C.; Stappers, B.W.; Weltevrede, P.

2015-01-01

Fast radio bursts (FRBs) are millisecond radio signals that exhibit dispersion larger than what the Galactic electron density can account for. We have conducted a 1446 h survey for FRBs at 145 MHz, covering a total of 4193 deg2 on the sky. We used the UK station of the low frequency array (LOFAR)

47 CFR 90.259 - Assignment and use of frequencies in the bands 216-220 MHz and 1427-1432 MHz.

Science.gov (United States)

2010-10-01

... MHz band are secondary to the Wireless Medical Telemetry Service except in the locations specified in... operations are secondary to the Wireless Medical Telemetry Service in the 1429-1431.5 MHz band. (3) All... 47 Telecommunication 5 2010-10-01 2010-10-01 false Assignment and use of frequencies in the bands...

Performance of the ELBE BPM Electronics

CERN Document Server

Evtushenko, P

2003-01-01

The ELBE radiation source is based on a superconducting linac. Initially it was designed to be used in CW mode with repetition rates either 13 MHz either 260 MHz. Later it was decided to operate the accelerator with reduced repetition rates for diagnostic reasons and for certain users. Now it is possible to operate at repetition rate 13/n MHz, where n can be 2, 4, 8, 16, 32, 64, and 128. It is required that the BPM system supports any of these operation modes. A core element of the BPM electronics is a logarithmic amplifier AD8313 made by Analog Devices Inc. The logarithmic amplifier is a direct RF to DC converter rated up to 2.5 GHz. Initial design of the BPM electronic was sophisticated only for CW operation with repetition rate more than 10 MHz, since bandwidth of the AD8313 is about of 10 MHz. Additionally a sample and hold amplifier is built in to provide enough time for an ADC to make measurements. The sample and hold amplifier is synchronized with a micropulse frequency. In the paper we present results...

Effects of acute and chronic exposure to both 900 MHz and 2100 MHz electromagnetic radiation on glutamate receptor signaling pathway.

Science.gov (United States)

Gökçek-Saraç, Çiğdem; Er, Hakan; Kencebay Manas, Ceren; Kantar Gok, Deniz; Özen, Şükrü; Derin, Narin

2017-09-01

To demonstrate the molecular effects of acute and chronic exposure to both 900 and 2100 MHz radiofrequency electromagnetic radiation (RF-EMR) on the hippocampal level/activity of some of the enzymes - including PKA, CaMKIIα, CREB, and p44/42 MAPK - from N-methyl-D-aspartate receptor (NMDAR)-related signaling pathways. Rats were divided into the following groups: sham rats, and rats exposed to 900 and 2100 MHz RF-EMR for 2 h/day for acute (1 week) or chronic (10 weeks), respectively. Western blotting and activity measurement assays were used to assess the level/activity of the selected enzymes. The obtained results revealed that the hippocampal level/activity of selected enzymes was significantly higher in the chronic groups as compared to the acute groups at both 900 and 2100 MHz RF-EMR exposure. In addition, hippocampal level/activity of selected enzymes was significantly higher at 2100 MHz RF-EMR than 900 MHz RF-EMR in both acute and chronic groups. The present study provides experimental evidence that both exposure duration (1 week versus 10 weeks) and different carrier frequencies (900 vs. 2100 MHz) had different effects on the protein expression of hippocampus in Wistar rats, which might encourage further research on protection against RF-EMR exposure.

Model of e-learning with electronic educational resources of new generation

Directory of Open Access Journals (Sweden)

A. V. Loban

2017-01-01

Full Text Available Purpose of the article: improving of scientific and methodical base of the theory of the е-learning of variability. Methods used: conceptual and logical modeling of the е-learning of variability process with electronic educational resource of new generation and system analysis of the interconnection of the studied subject area, methods, didactics approaches and information and communication technologies means. Results: the formalization complex model of the е-learning of variability with electronic educational resource of new generation is developed, conditionally decomposed into three basic components: the formalization model of the course in the form of the thesaurusclassifier (“Author of e-resource”, the model of learning as management (“Coordination. Consultation. Control”, the learning model with the thesaurus-classifier (“Student”. Model “Author of e-resource” allows the student to achieve completeness, high degree of didactic elaboration and structuring of the studied material in triples of variants: modules of education information, practical task and control tasks; the result of the student’s (author’s of e-resource activity is the thesaurus-classifier. Model of learning as management is based on the principle of personal orientation of learning in computer environment and determines the logic of interaction between the lecturer and the student when determining the triple of variants individually for each student; organization of a dialogue between the lecturer and the student for consulting purposes; personal control of the student’s success (report generation and iterative search for the concept of the class assignment in the thesaurus-classifier before acquiring the required level of training. Model “Student” makes it possible to concretize the learning tasks in relation to the personality of the student and to the training level achieved; the assumption of the lecturer about the level of training of a

Cambridge observations at 38-115 MHz and their implications for space astronomy

International Nuclear Information System (INIS)

Saunders, R.

1987-01-01

The design and performance of the Cambridge LF telescopes are reviewed. Consideration is given to the 151-MHz 6C telescope, the 38-MHz and 151-MHz LF synthesis telescopes, 81.5-MHz interplanetary scintillation observations with the 3.6-hectare array, long-baseline interferometry at 81.5 MHz, and the use of the Jodrell Bank MERLIN for 151-MHz closure-phase observations of bright sources. The strict limitation on the field mappable at a given resolution in ground-based observations at these frequencies is pointed out, and some outstanding astronomical problems requiring 0.3-30-MHz space observations are listed. 7 references

A survey of the use of electronic scientific information resources among medical and dental students

Directory of Open Access Journals (Sweden)

Aarnio Matti

2006-05-01

Full Text Available Abstract Background To evaluate medical and dental students' utilization of electronic information resources. Methods A web survey sent to 837 students (49.9% responded. Results Twenty-four per cent of medical students and ninteen per cent of dental students searched MEDLINE 2+ times/month for study purposes, and thiry-two per cent and twenty-four per cent respectively for research. Full-text articles were used 2+ times/month by thirty-three per cent of medical and ten per cent of dental students. Twelve per cent of respondents never utilized either MEDLINE or full-text articles. In multivariate models, the information-searching skills among students were significantly associated with use of MEDLINE and full-text articles. Conclusion Use of electronic resources differs among students. Forty percent were non-users of full-text articles. Information-searching skills are correlated with the use of electronic resources, but the level of basic PC skills plays not a major role in using these resources. The student data shows that adequate training in information-searching skills will increase the use of electronic information resources.

Access to electronic information resources by students of federal ...

African Journals Online (AJOL)

The paper discusses access to electronic information resources by students of Federal Colleges of Education in Eha-Amufu and Umunze. Descriptive survey design was used to investigate sample of 526 students. Sampling technique used was a Multi sampling technique. Data for the study were generated using ...

Adoption and use of electronic information resources by medical ...

African Journals Online (AJOL)

This study investigated the adoption and use of electronic information resources by medical science students of the University of Benin. The descriptive survey research design was adopted for the study and 390 students provided the data. Data collected were analysed with descriptive Statistics(Simple percentage and ...

Where Do Electronic Books Fit in the College Research Arsenal of Resources?

Science.gov (United States)

Barbier, Patricia

2007-01-01

Student use of electronic books has become an accepted supplement to traditional resources. Student use and satisfaction was monitored through an online course discussion board. Increased use of electronic books indicate this service is an accepted supplement to the print book collection.

Characterization of an Atmospheric-Pressure Argon Plasma Generated by 915 MHz Microwaves Using Optical Emission Spectroscopy

Directory of Open Access Journals (Sweden)

Robert Miotk

2017-01-01

Full Text Available The paper presents the investigations of an atmospheric-pressure argon plasma generated at 915 MHz microwaves using the optical emission spectroscopy (OES. The 915 MHz microwave plasma was inducted and sustained in a waveguide-supplied coaxial-line-based nozzleless microwave plasma source. The aim of presented investigations was to estimate parameters of the generated plasma, that is, excitation temperature of electrons Texc, temperature of plasma gas Tg, and concentration of electrons ne. Assuming that excited levels of argon atoms are in local thermodynamic equilibrium, Boltzmann method allowed in determining the Texc temperature in the range of 8100–11000 K. The temperature of plasma gas Tg was estimated by comparing the simulated spectra of the OH radical to the measured one in LIFBASE program. The obtained Tg temperature ranged in 1200–2800 K. Using a method based on Stark broadening of the Hβ line, the concentration of electrons ne was determined in the range from 1.4 × 1015 to 1.7 × 1015 cm−3, depending on the power absorbed by the microwave plasma.

Effects of sintering temperature on properties of toroid cores using NiZnCu ferrites for power applications at >1 MHz

Science.gov (United States)

Liu, Junchang; Mei, Yunhui; Liu, Wen; Li, Xin; Hou, Feng; Lu, Guo-Quan

2018-05-01

The microstructures, magnetic and electronic performance of NiZnCu ferrites have been investigated at temperature from 850 °C to 1000 °C. X-ray diffraction (XRD) patterns showed that only single phase with spinel structure existed. Scanning electron microscopy (SEM) results showed that grain size increased with enhancement of sintering temperature and the most homogeneous, compact microstructure was obtained at 950 °C. Magnetic properties measurements revealed that both complex permeability and saturation magnetization increased with increasing of sintering temperature. The initial permeability was approximately linear within the scope of 850-1000 °C as well as the resonance frequency decreased from 70 MHz to 30 MHz. Power loss density tests demonstrated that the core sintered at 950 °C instead of the one sintered at 1000 °C had the lower power loss density at both 5 mT and 10 mT and the higher inductance under a certain exciting direct current at 1 MHz. Also the inductance of the sample sintered at the higher temperature dropped faster than that at the lower temperature. The results showed that the core sintered at 950 °C had better electrical performance and was suitable for wide usage.

Fabrication of the prototype 201.25 MHZ cavity for a muon ionization cooling experiment

International Nuclear Information System (INIS)

Rimmer, R.A.; Manning, S.; Manus, R.; Phillips, L.; Stirbet, M.; Worland, K.; Wu, G.; Li, D.; MacGill, R.; Staples, J.; Virostek, S.; Zisman, M.S.; Taminger, K.; Hafley, R.; Martin, R.; Summers, D.; Reep, M.

2005-01-01

We describe the fabrication and assembly of the first prototype 201. 25 MHz copper cavity for the muon ionization cooling experiment (MICE). This cavity was developed by the US MUCOOL collaboration and will be tested in the new MUCOOL Test Area at Fermilab. We outline the component and subassembly fabrication steps and the various metal forming and joining methods used to produce the final cavity shape. These include spinning, brazing, TIG welding, electron beam welding, electron beam annealing and deep drawing. Some of the methods developed for this cavity are novel and offer significant cost savings over conventional methods

A matched Bow-tie antenna at 433MHz for use in underwater wireless sensor networks

International Nuclear Information System (INIS)

Abdou, A A; Shaw, A; Mason, A; Al-Shamma'a, A; Cullen, J; Wylie, S; Diallo, M

2013-01-01

Electromagnetic (EM) wave propagation underwater is been disregarded because of attenuation at high frequencies, however the theory predicts that propagation is possible at some useful distance in the lower Industrial, Scientific and Medical (ISM) band. Common transceivers rely on narrowband antennas and matching circuit. The aim of this paper is to design a broadband 433MHz bow-tie antenna and experiment it in air and water without a matching circuit. This antenna could be attached to wireless transceivers and form a Wireless Sensor Network for deployment in various underwater applications. The bow-tie antennas were designed, simulated and constructed in laboratory. Experiments were setup carefully by using a completely isolated transmitter from electronics to avoid airborne transmission. The 433MHz. bow-tie proved its suitability for use in Underwater.

Strategic Planning for Electronic Resources Management: A Case Study at Gustavus Adolphus College

Science.gov (United States)

Hulseberg, Anna; Monson, Sarah

2009-01-01

Electronic resources, the tools we use to manage them, and the needs and expectations of our users are constantly evolving; at the same time, the roles, responsibilities, and workflow of the library staff who manage e-resources are also in flux. Recognizing a need to be more intentional and proactive about how we manage e-resources, the…

REVIEW OF MOODLE PLUGINS FOR DESIGNING MULTIMEDIA ELECTRONIC EDUCATIONAL RESOURCES FROM LANGUAGE DISCIPLINES

Directory of Open Access Journals (Sweden)

Anton M. Avramchuk

2015-09-01

Full Text Available Today the problem of designing multimedia electronic educational resources from language disciplines in Moodle is very important. This system has a lot of different, powerful resources, plugins to facilitate the learning of students with language disciplines. This article presents an overview and comparative analysis of the five Moodle plugins for designing multimedia electronic educational resources from language disciplines. There have been considered their key features and functionality in order to choose the best for studying language disciplines in the Moodle. Plugins are compared by a group of experts according to the criteria: efficiency, functionality and easy use. For a comparative analysis of the plugins it is used the analytic hierarchy process.

78 FR 42701 - Improving Public Safety Communications in the 800 MHz Band

Science.gov (United States)

2013-07-17

...] Improving Public Safety Communications in the 800 MHz Band AGENCY: Federal Communications Commission. ACTION...-901 MHz/935- 940 MHz band (900 MHz B/ILT Band) to allow a qualified entity to file an application for..., manufacturing, energy) to non-commercial (e.g., clerical, educational, philanthropic, medical). In 2004, the...

Modern ICT Tools: Online Electronic Resources Sharing Using Web ...

African Journals Online (AJOL)

Modern ICT Tools: Online Electronic Resources Sharing Using Web 2.0 and Its Implications For Library And Information Practice In Nigeria. ... The PDF file you selected should load here if your Web browser has a PDF reader plug-in installed (for example, a recent version of Adobe Acrobat Reader). If you would like more ...

Considerations of Physical Design and Implementation for 5 MHz-100 W LLC Resonant DC-DC Converters

Directory of Open Access Journals (Sweden)

Akinori Hariya

2016-01-01

Full Text Available Recently, high power-density, high power-efficiency, and wide regulation range isolated DC-DC converters have been required. This paper presents considerations of physical design and implementation for wide regulation range MHz-level LLC resonant DC-DC converters. The circuit parameters are designed with 3–5 MHz-level switching frequency. Also, the physical parameters and the size of the planar transformer are optimized by using derived equations and finite element method (FEM with Maxwell 3D. Some experiments are done with prototype LLC resonant DC-DC converter using gallium nitride high electron mobility transistors (GaN-HEMTs; the input voltage is 42–53 V, the reference output voltage is 12 V, the load current is 8 A, the maximum switching frequency is about 5 MHz, the total volume of the circuit is 4.1 cm3, and the power density of the prototype converter is 24.4 W/cc.

Some results of observations of solar radio bursts of the ''drift pairs'' type near 25 and 12.5 MHz

International Nuclear Information System (INIS)

Abranin, Eh.P.; Bazelyan, L.L.; Goncharov, N.Yu.; Zajtsev, V.V.; Zinichev, V.A.; Levin, B.N.; Rapoport, V.O.; Tsybko, Ya.G.; Gor'kovskij Gosudarstvennyj Univ.

1977-01-01

The drift pairs in the frequency range of 12-13 MHz and 24-26 MHz are considered. It is shown that double bursts may be observed both at the second and at the first harmonics. The time interval between the elements of the double burst remains practically unchanged. This fact creates difficulties when interpreting double bursts due to the radio echo in the solar corona. It is suggested that the double (and generally multiple) structure of burst may be associated with the successive transmission of a fast electron beam in regions of double plasma resonance. It is considered that the radiation occurs due to cyclotron instability at the forward front of the electron beam travelling along the decreasing magnetic field of the coronal ray. It is shown that the properties of these burst can be explained by the proposed mechanism of drift pairs formation

Silicon Nitride Deposition for Flexible Organic Electronic Devices by VHF (162 MHz)-PECVD Using a Multi-Tile Push-Pull Plasma Source.

Science.gov (United States)

Kim, Ki Seok; Kim, Ki Hyun; Ji, You Jin; Park, Jin Woo; Shin, Jae Hee; Ellingboe, Albert Rogers; Yeom, Geun Young

2017-10-19

Depositing a barrier film for moisture protection without damage at a low temperature is one of the most important steps for organic-based electronic devices. In this study, the authors investigated depositing thin, high-quality SiN x film on organic-based electronic devices, specifically, very high-frequency (162 MHz) plasma-enhanced chemical vapor deposition (VHF-PECVD) using a multi-tile push-pull plasma source with a gas mixture of NH 3 /SiH 4 at a low temperature of 80 °C. The thin deposited SiN x film exhibited excellent properties in the stoichiometry, chemical bonding, stress, and step coverage. Thin film quality and plasma damage were investigated by the water vapor transmission rate (WVTR) and by electrical characteristics of organic light-emitting diode (OLED) devices deposited with SiN x , respectively. The thin deposited SiN x film exhibited a low WVTR of 4.39 × 10 -4  g (m 2 · day) -1 for a single thin (430 nm thick) film SiN x and the electrical characteristics of OLED devices before and after the thin SiN x film deposition on the devices did not change, which indicated no electrical damage during the deposition of SiN x on the OLED device.

47 CFR 90.353 - LMS operations in the 902-928 MHz band.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false LMS operations in the 902-928 MHz band. 90.353... operations in the 902-928 MHz band. LMS systems may be authorized within the 902-928 MHz band, subject to the..., scientific, and medical (ISM) devices and radiolocation Government stations that operate in the 902-928 MHz...

Performance of a permanent-magnet helicon source at 27 and 13 MHz

Energy Technology Data Exchange (ETDEWEB)

Chen, Francis F. [Electrical Engineering Department, University of California, Los Angeles, California 90095 (United States)

2012-09-15

A small helicon source is used to create dense plasma and inject it into a large chamber. A permanent magnet is used for the dc magnetic field (B-field), making the system very simple and compact. Though theory predicts that better antenna coupling will occur at 27.12 MHz, it was found that 13.56 MHz surprisingly gives even higher density due to practical effects not included in theory. Complete density n and electron temperature T{sub e} profiles are measured at three distances below the source. The plasma inside the source is also measured with a special probe, even under the antenna. The density there is lower than expected because the plasma created is immediately ejected, filling the experimental chamber. The advantage of helicons over inductively coupled plasmas (with no B-field) increases with RF power. At high B-fields, edge ionization by the Trivelpiece-Gould mode can be seen. These results are useful for design of multiple-tube, large-area helicon sources for plasma etching and deposition because problems are encountered which cannot be foreseen by theory alone.

THE MODEL OF LINGUISTIC TEACHERS’ COMPETENCY DEVELOPMENT ON DESIGNING MULTIMEDIA ELECTRONIC EDUCATIONAL RESOURCES IN THE MOODLE SYSTEM

Directory of Open Access Journals (Sweden)

Anton M. Avramchuk

2017-10-01

Full Text Available The article is devoted to the problem of developing the competency of teachers of language disciplines on designing multimedia electronic educational resources in the Moodle system. The concept of "the competence of teachers of language disciplines on designing multimedia electronic educational resources in the Moodle system" is justified and defined. Identified and characterized the components by which the levels of the competency development of teachers of language disciplines on designing multimedia electronic educational resources in the Moodle system should be assessed. Developed a model for the development of the competency of teachers of language disciplines on designing multimedia electronic educational resources in the Moodle system, which is based on the main scientific approaches, used in adult education, and consists of five blocks: target, informative, technological, diagnostic and effective.

Developing Humanities Collections in the Digital Age: Exploring Humanities Faculty Engagement with Electronic and Print Resources

Science.gov (United States)

Kachaluba, Sarah Buck; Brady, Jessica Evans; Critten, Jessica

2014-01-01

This article is based on quantitative and qualitative research examining humanities scholars' understandings of the advantages and disadvantages of print versus electronic information resources. It explores how humanities' faculty members at Florida State University (FSU) use print and electronic resources, as well as how they perceive these…

Direct-written polymer field-effect transistors operating at 20 MHz.

Science.gov (United States)

Perinot, Andrea; Kshirsagar, Prakash; Malvindi, Maria Ada; Pompa, Pier Paolo; Fiammengo, Roberto; Caironi, Mario

2016-12-12

Printed polymer electronics has held for long the promise of revolutionizing technology by delivering distributed, flexible, lightweight and cost-effective applications for wearables, healthcare, diagnostic, automation and portable devices. While impressive progresses have been registered in terms of organic semiconductors mobility, field-effect transistors (FETs), the basic building block of any circuit, are still showing limited speed of operation, thus limiting their real applicability. So far, attempts with organic FETs to achieve the tens of MHz regime, a threshold for many applications comprising the driving of high resolution displays, have relied on the adoption of sophisticated lithographic techniques and/or complex architectures, undermining the whole concept. In this work we demonstrate polymer FETs which can operate up to 20 MHz and are fabricated by means only of scalable printing techniques and direct-writing methods with a completely mask-less procedure. This is achieved by combining a fs-laser process for the sintering of high resolution metal electrodes, thus easily achieving micron-scale channels with reduced parasitism down to 0.19 pF mm -1 , and a large area coating technique of a high mobility polymer semiconductor, according to a simple and scalable process flow.

B-mode for thyroid nodule characterization at 7.5 MHz versus 13 MHz; Attualita' dell'ecografia nel modo B nella caratterizzazione delle malattie nodulari tiroidee: studio ecografiaco di confronto con sonde da 7.5 e da 13 MHz

Energy Technology Data Exchange (ETDEWEB)

Amodio, F.; Carbone, M.; Rossi, E.; Brunese, L.; Vallone, G. [Neaples Univ., Neaples (Italy). Dipt. di Scienze Biomorfologiche, Ist. di Scienze Radiologiche; Pisano, G.; Iorio, S. [Neaples Univ., Neaples (Italy). Dipt. di Scienze Biomorfologiche, Sez. di Anatomia Patologica e Citopatologica; Benincasa, G. [Neaples Univ., Neaples (Italy). Dipt. di Scienze Biomorfologiche, Ist. di Endocrinologia, Medicina Interna e Malattie della Nutrizione

1999-09-01

The paper investigates B-mode ultrasonography capabilities in diagnosis and characterizing thyroid nodules and compared the personal experience findings with those of few analytical studies in the literature. It is also compared the diagnostic accuracy of conventional 7.5 MHz versus more recent 13 MHz transducers. [Italian] Lo studio presenta i dati sull'accuratezza diagnostica dell'ecografia nel modo B con trasduttore da 7.5 MHz con quella di un trasduttore di piu' recente commercializzazione da 13 MHz. E' una tappa fondamentale nell'iter diagnostico del nodulo tiroideo, se integrata con lo studio qualitativo (color e power Doppler) e semiquantitativo (Doppler pulsato) della vascolarizzazione nodulare.

Acceleration performance of a 50-MHz split coaxial RFQ and the design of a 25.5-MHz prototype

International Nuclear Information System (INIS)

Tokuda, N.; Arai, S.; Fukushima, T.; Morimoto, T.; Tojyo, E.

1989-03-01

Acceleration tests on a 50-MHz split coaxial RFQ have been conducted at INS. The 2-m long RFQ has accelerated protons from 2 to 60 keV. The experimental results concerning beam emittance and transmission efficiency agree with predictions of a computer simulation. Following this success, we are fabricating a 25.5-MHz prototype of 2-m long. The issues of the study are to establish a structure standing a high-power operation and to accelerate heavy ions with a charge-to-mass ratio larger than 1/30. (author)

VLITE Surveys the Sky: A 340 MHz Companion to the VLA Sky Survey (VLASS)

Science.gov (United States)

Peters, Wendy; Clarke, Tracy; Brisken, Walter; Cotton, William; Richards, Emily E.; Giacintucci, Simona; Kassim, Namir

2018-01-01

The VLA Low Band Ionosphere and Transient Experiment (VLITE; ) is a commensal observing system on the Karl G. Janksy Very Large Array (VLA) which was developed by the Naval Research Laboratory and NRAO. A 64 MHz sub-band from the prime focus 240-470 MHz dipoles is correlated during nearly all regular VLA observations. VLITE uses dedicated samplers and fibers, as well as a custom designed, real-time DiFX software correlator, and requires no additional resources from the VLA system running the primary science program. The experiment has been operating since November 2014 with 10 antennas; a recent expansion in summer 2017 increased that number to 16 and more than doubled the number of baselines.The VLA Sky Survey (VLASS; ), is an ongoing survey of the entire sky visible to the VLA at a frequency of 2-4 GHz. The observations are made using an "on-the-fly" (OTF) continuous RA scanning technique which fills in the sky by observing along rows of constant declination. VLITE breaks the data into 2-second integrations and correlates these at a central position every 1.5 degrees. All data for each correlator position is imaged separately, corrected and weighted by an appropriately elongated primary beam model, and then combined in the image plane to create a mosaic of the sky. A catalog of the sources is extracted to provide a 340 MHz sky model.We present preliminary images and catalogs from the 2017 VLASS observations which began in early September, 2017, and continued on a nearly daily basis throughout the fall. In addition to providing a unique sky model at 340 MHz, these data complement VLASS by providing spectral indices for all cataloged sources.

Electronic resource management systems a workflow approach

CERN Document Server

Anderson, Elsa K

2014-01-01

To get to the bottom of a successful approach to Electronic Resource Management (ERM), Anderson interviewed staff at 11 institutions about their ERM implementations. Among her conclusions, presented in this issue of Library Technology Reports, is that grasping the intricacies of your workflow-analyzing each step to reveal the gaps and problems-at the beginning is crucial to selecting and implementing an ERM. Whether the system will be used to fill a gap, aggregate critical data, or replace a tedious manual process, the best solution for your library depends on factors such as your current soft

Electronic Resource Management System. Vernetzung von Lizenzinformationen

Directory of Open Access Journals (Sweden)

Michaela Selbach

2014-12-01

Full Text Available In den letzten zehn Jahren spielen elektronische Ressourcen im Bereich der Erwerbung eine zunehmend wichtige Rolle: Eindeutig lässt sich hier ein Wandel in den Bibliotheken (fort vom reinen Printbestand zu immer größeren E-Only-Beständen feststellen. Die stetig wachsende Menge an E-Ressourcen und deren Heterogenität stellt Bibliotheken vor die Herausforderung, die E-Ressourcen effizient zu verwalten. Nicht nur Bibliotheken, sondern auch verhandlungsführende Institutionen von Konsortial- und Allianzlizenzen benötigen ein geeignetes Instrument zur Verwaltung von Lizenzinformationen, welches den komplexen Anforderungen moderner E-Ressourcen gerecht wird. Die Deutsche Forschungsgemeinschaft (DFG unterstützt ein Projekt des Hochschulbibliothekszentrums des Landes Nordrhein-Westfalen (hbz, der Universitätsbibliothek Freiburg, der Verbundzentrale des Gemeinsamen Bibliotheksverbundes (GBV und der Universitätsbibliothek Frankfurt, in dem ein bundesweit verfügbares Electronic Ressource Managementsystem (ERMS aufgebaut werden soll. Ein solches ERMS soll auf Basis einer zentralen Knowledge Base eine einheitliche Nutzung von Daten zur Lizenzverwaltung elektronischer Ressourcen auf lokaler, regionaler und nationaler Ebene ermöglichen. Statistische Auswertungen, Rechteverwaltung für alle angeschlossenen Bibliotheken, kooperative Datenpflege sowie ein über standardisierte Schnittstellen geführter Datenaustausch stehen bei der Erarbeitung der Anforderungen ebenso im Fokus wie die Entwicklung eines Daten- und Funktionsmodells. In the last few years the importance of electronic resources in library acquisitions has increased significantly. There has been a shift from mere print holdings to both e- and print combinations and even e-only subscriptions. This shift poses a double challenge for libraries: On the one hand they have to provide their e-resource collections to library users in an appealing way, on the other hand they have to manage these

The Electron Microscopy Outreach Program: A Web-based resource for research and education.

Science.gov (United States)

Sosinsky, G E; Baker, T S; Hand, G; Ellisman, M H

1999-01-01

We have developed a centralized World Wide Web (WWW)-based environment that serves as a resource of software tools and expertise for biological electron microscopy. A major focus is molecular electron microscopy, but the site also includes information and links on structural biology at all levels of resolution. This site serves to help integrate or link structural biology techniques in accordance with user needs. The WWW site, called the Electron Microscopy (EM) Outreach Program (URL: http://emoutreach.sdsc.edu), provides scientists with computational and educational tools for their research and edification. In particular, we have set up a centralized resource containing course notes, references, and links to image analysis and three-dimensional reconstruction software for investigators wanting to learn about EM techniques either within or outside of their fields of expertise. Copyright 1999 Academic Press.

470‐MHz–698‐MHz IEEE 802.15.4m Compliant RF CMOS Transceiver

Directory of Open Access Journals (Sweden)

Youngho Seo

2018-04-01

Full Text Available This paper proposes an IEEE 802.15.4m compliant TV white‐space orthogonal frequency‐division multiplexing (TVWS‐(OFDM radio frequency (RF transceiver that can be adopted in advanced metering infrastructures, universal remote controllers, smart factories, consumer electronics, and other areas. The proposed TVWS‐OFDM RF transceiver consists of a receiver, a transmitter, a 25% duty‐cycle local oscillator generator, and a delta‐sigma fractional‐N phase‐locked loop. In the TV band from 470 MHz to 698 MHz, the highly linear RF transmitter protects the occupied TV signals, and the high‐Q filtering RF receiver is tolerable to in‐band interferers as strong as −20 dBm at a 3‐MHz offset. The proposed TVWS‐OFDM RF transceiver is fabricated using a 0.13‐μm CMOS process, and consumes 47 mA in the Tx mode and 35 mA in the Rx mode. The fabricated chip shows a Tx average power of 0 dBm with an error‐vector‐magnitude of  3%, and a sensitivity level of −103 dBm with a packet‐error‐rate of 3%. Using the implemented TVWS‐OFDM modules, a public demonstration of electricity metering was successfully carried out.

Technical Communicator: A New Model for the Electronic Resources Librarian?

Science.gov (United States)

Hulseberg, Anna

2016-01-01

This article explores whether technical communicator is a useful model for electronic resources (ER) librarians. The fields of ER librarianship and technical communication (TC) originated and continue to develop in relation to evolving technologies. A review of the literature reveals four common themes for ER librarianship and TC. While the…

915 MHz microwave ablation with high output power in in vivo porcine spleens

International Nuclear Information System (INIS)

Gao Yongyan; Wang Yang; Duan Yaqi; Li Chunling; Sun Yuanyuan; Zhang Dakun; Lu Tong; Liang Ping

2010-01-01

Objective: The purpose of this study was to evaluate the efficacy of 915 MHz microwave (MW) ablation with high output power in in vivo porcine spleens. Materials and methods: MW ablations were performed in 9 porcine spleens with an internally cooled 915 MHz antenna. Thermocouples were placed at 5, 10, 15, 20 mm away from the antenna to measure temperatures in real-time during MW emission. The energy was applied for 10 min at high output power of 60 W, 70 W or 80 W. Gross specimens were sectioned and measured to determine ablation size. Representative areas were examined by light microscopy and electron microscopy. Coagulation sizes and temperatures were compared among the three power groups. Results: Hematoxylin-eosin staining showed irreversible necrosis in the splenic coagulation area after MW ablation. As the power was increased, long-axis diameter enlarged significantly (p .05). The coagulation size of long-axis and short-axis diameter with 80 W in vivo spleen ablation was 6.43 ± 0.52 and 4.95 ± 0.30 cm, respectively. With the increase of output power, maximum temperatures at 5, 10, 15, 20 mm from the antenna were increased accordingly (p o C respectively. Conclusion: With internally cooled antenna and high output power, 915 MHz MW ablation in the spleen could produce irreversible tissue necrosis of clinical significance. MW ablation may be used as a promising minimally invasive method for the treatment of splenic diseases.

Development of superconducting RF cavity at 1050 MHz frequency for an electron LINAC

International Nuclear Information System (INIS)

Sarkar, S.G.; Mondal, J.; Mittal, K.C.

2011-01-01

This paper reports the design of a prototype superconducting cavity at 1050 MHz and design of associated die punch and machining fixtures for the cavity fabrication. The cavity is of β= 1 and elliptical in shape. The circle-straight line-ellipse-type structure design has been optimized by 'SUPERFISH' - a 2 dimensional code for cavity tuning. The 3 Dimensional EM field analysis of the cavity structure has been done using 'CST' software. The ratio of the maximum surface electric field to the accelerating gradient, E pk /E acc , is optimised to 1.984 and H pk /E acc is optimised to 4.141 mT/(MV/m). Bore radius of the cavity has been chosen such a way so that the cell-to-cell coupling remains as high as 1.85%. The cavity is designed to achieve 25 MV/m accelerating gradient. (author)

Calibration of an advanced photon source linac beam position monitor used for positron position measurement of a beam containing both positrons and electrons

International Nuclear Information System (INIS)

Sereno, Nicholas S.

1998-01-01

The Advanced Photon Source (APS) linac beam position monitors can be used to monitor the position of a beam containing both positrons and electrons. To accomplish this task, both the signal at the bunching frequency of 2856 MHz and the signal at 2x2856 MHz are acquired and processed for each stripline. The positron beam position is obtained by forming a linear combination of both 2856 and 5712 MHz signals for each stripline and then performing the standard difference over sum computation. The required linear combination of the 2856 and 5712 MHz signals depends on the electrical calibration of each stripline/cable combination. In this paper, the calibration constants for both 2856 MHz and 5712 MHz signals for each stripline are determined using a pure beam of electrons. The calibration constants are obtained by measuring the 2856 and 5712 MHz stripline signals at various electron beam currents and positions. Finally, the calibration constants measured using electrons are used to determine positron beam position for the mixed beam case

Comparison of 864 and 935 MHz microwave radiation effects on cell culture

International Nuclear Information System (INIS)

Pavicic, I.; Trosic, I.; Sarolic, A.

2005-01-01

The aim of our study was to evaluate and compare the effect of 864 and 935 MHz microwave radiation on proliferation, colony forming and viability of Chinese hamster lung cells, cell line V79. Cell cultures were exposed both to the 864 MHz microwave field in transversal electromagnetic mode cell (TEM-cell) and to the 935 MHz field in Gigahertz transversal electromagnetic mode cell (GTEM-cell) for 1, 2 and 3 hours. Philips PM 5508 generator connected with a signal amplifier generated the frequency of 864 MHz, whereas Hewlett Packard HP8657A signal generator was used to generate the frequency of 935 MHz. The average specific absorption rate (SAR) was 0.08 W/kg for 864 MHz and 0.12 W/kg for 935 MHz. To determine the cell growth, V79 cells were plated in the concentration of 1x10 4 cells per milliliter of nutrient medium. Cells were cultured in a humidified atmosphere at 37 degrees of C in 5% CO 2 . Cell proliferation was determined by cell counts for each hour of exposure during the five post-exposure days. To identify colony-forming ability, cells were cultivated in the concentration of 40 cells/mL of medium and incubated as described above. Colony-forming ability was assessed for each exposure time by colony count on post-exposure day 7. Trypan blue exclusion test was used to determine cell viability. On post-exposure day 3, the growth curve of 864 MHz irradiated cells showed a significant decrease (p less than 0.05) after 2 and 3 hours of exposure in comparison with control cells. Cells exposed to 935 MHz radiation showed a significant decrease (p less than 0.05) after 3 hours of exposure on post-exposure day 3. Both the colony-forming ability and viability of 864 MHz and 935 MHz exposed cells did not significantly differ from matched control cells. In conclusion, both applied RF/MW fields have shown similar effects on cell culture growth, colony forming and cell viability of the V79 cell line.(author)

Subharmonic buncher for the Los Alamos free-electron laser oscillator experiment

International Nuclear Information System (INIS)

Fraser, J.S.

1983-01-01

A high efficiency free-electron laser oscillator experiment is being constructed at Los Alamos National Laboratory. A buncher system has been designed to deliver 30-ps, 5-nC electron bunches to a 20-MeV standing-wave linac at the 60th subharmonic of the 1300-MHz accelerator frequency. The first 108.3-MHz buncher cavity accepts a 5-ns, 5-A peak current pulse from a triode gun. Following a 120-cm drift space, a second 108.3-MHz cavity is used, primarily to enhance the bunching of the trailing half of the bunch. A 1300-MHz cavity with 20-cm drift spaces at the each end completes the beamline components. The bunching process continues into the linac's first three accelerating cells. Two thin iron-shielded lenses and several large-diameter solenoids provide axial magnetic fields for radial focusing

Evaluating the More Suitable ISM Frequency Band for IoT-Based Smart Grids: A Quantitative Study of 915 MHz vs. 2400 MHz

Directory of Open Access Journals (Sweden)

Ruben M. Sandoval

2016-12-01

Full Text Available IoT has begun to be employed pervasively in industrial environments and critical infrastructures thanks to its positive impact on performance and efficiency. Among these environments, the Smart Grid (SG excels as the perfect host for this technology, mainly due to its potential to become the motor of the rest of electrically-dependent infrastructures. To make this SG-oriented IoT cost-effective, most deployments employ unlicensed ISM bands, specifically the 2400 MHz one, due to its extended communication bandwidth in comparison with lower bands. This band has been extensively used for years by Wireless Sensor Networks (WSN and Mobile Ad-hoc Networks (MANET, from which the IoT technologically inherits. However, this work questions and evaluates the suitability of such a “default” communication band in SG environments, compared with the 915 MHz ISM band. A comprehensive quantitative comparison of these bands has been accomplished in terms of: power consumption, average network delay, and packet reception rate. To allow such a study, a dual-band propagation model specifically designed for the SG has been derived, tested, and incorporated into the well-known TOSSIM simulator. Simulation results reveal that only in the absence of other 2400 MHz interfering devices (such as WiFi or Bluetooth or in small networks, is the 2400 MHz band the best option. In any other case, SG-oriented IoT quantitatively perform better if operating in the 915 MHz band.

Evaluating the More Suitable ISM Frequency Band for IoT-Based Smart Grids: A Quantitative Study of 915 MHz vs. 2400 MHz.

Science.gov (United States)

Sandoval, Ruben M; Garcia-Sanchez, Antonio-Javier; Garcia-Sanchez, Felipe; Garcia-Haro, Joan

2016-12-31

IoT has begun to be employed pervasively in industrial environments and critical infrastructures thanks to its positive impact on performance and efficiency. Among these environments, the Smart Grid (SG) excels as the perfect host for this technology, mainly due to its potential to become the motor of the rest of electrically-dependent infrastructures. To make this SG-oriented IoT cost-effective, most deployments employ unlicensed ISM bands, specifically the 2400 MHz one, due to its extended communication bandwidth in comparison with lower bands. This band has been extensively used for years by Wireless Sensor Networks (WSN) and Mobile Ad-hoc Networks (MANET), from which the IoT technologically inherits. However, this work questions and evaluates the suitability of such a "default" communication band in SG environments, compared with the 915 MHz ISM band. A comprehensive quantitative comparison of these bands has been accomplished in terms of: power consumption, average network delay, and packet reception rate. To allow such a study, a dual-band propagation model specifically designed for the SG has been derived, tested, and incorporated into the well-known TOSSIM simulator. Simulation results reveal that only in the absence of other 2400 MHz interfering devices (such as WiFi or Bluetooth) or in small networks, is the 2400 MHz band the best option. In any other case, SG-oriented IoT quantitatively perform better if operating in the 915 MHz band.

Harmonic Kicker RF Cavity for the Jefferson Lab Electron-Ion Collider EM Simulation, Modification, and Measurements

Science.gov (United States)

Overstreet, Sarah; Wang, Haipeng

2017-09-01

An important step in the conceptual design for the future Jefferson Lab Electron-Ion Collider (JLEIC) is the development of supporting technologies for the Energy Recovery Linac (ERL) Electron Cooling Facility. The Harmonic Radiofrequency (RF) kicker cavity is one such device that is responsible for switching electron bunches in and out of the Circulator Cooling Ring (CCR) from and to the ERL, which is a critical part of the ion cooling process. Last year, a half scale prototype of the JLEIC harmonic RF kicker model was designed with resonant frequencies to support the summation of 5 odd harmonics (95.26 MHz, 285.78 MHz, 476.30 MHz, 666.82 MHz, and 857.35 MHz); however, the asymmetry of the kicker cavity gives rise to multipole components of the electric field at the electron-beam axis of the cavity. Previous attempts to symmetrize the electric field of this asymmetrical RF cavity have been unsuccessful. The aim of this study is to modify the existing prototype for a uniform electric field across the beam pathway so that the electron bunches will experience nearly zero beam current loading. In addition to this, we have driven the unmodified cavity with the harmonic sum and used the wire stretching method for an analysis of the multipole electric field components.

MODEL OF AN ELECTRONIC EDUCATIONAL RESOURCE OF NEW GENERATION

Directory of Open Access Journals (Sweden)

Anatoliy V. Loban

2016-01-01

Full Text Available The mathematical structure of the modular architecture of an electronic educational resource (EER of new generation, which allows to decompose the process of studying the subjects of the course at a hierarchically ordered set of data (knowledge and procedures for manipulating them, to determine the roles of participants of process of training of and technology the development and use of EOR in the study procrate.

Heat transfer enhancement using 2MHz ultrasound.

Science.gov (United States)

Bulliard-Sauret, Odin; Ferrouillat, Sebastien; Vignal, Laure; Memponteil, Alain; Gondrexon, Nicolas

2017-11-01

The present work focuses on possible heat transfer enhancement from a heating plate towards tap water in forced convection by means of 2MHz ultrasound. The thermal approach allows to observe the increase of local convective heat transfer coefficients in the presence of ultrasound and to deduce a correlation between ultrasound power and Nusselt number. Heat transfer coefficient under ultrasound remains constant while heat transfer coefficient under silent conditions increases with Reynolds number from 900 up to 5000. Therefore, heat transfer enhancement factor ranges from 25% up to 90% for the same energy conditions (supplied ultrasonic power=110W and supplied thermal power=450W). In the same time cavitational activity due to 2MHz ultrasound emission was characterized from mechanical and chemical viewpoints without significant results. At least, Particle Image Velocimetry (PIV) measurements have been performed in order to investigate hydrodynamic modifications due to the presence of 2MHz ultrasound. It was therefore possible to propose a better understanding of heat transfer enhancement mechanism with high frequency ultrasound. Copyright © 2017 Elsevier B.V. All rights reserved.

Parametric thermal analysis of 75 MHz heavy ion RFQ

International Nuclear Information System (INIS)

Mishra, N.K.; Mehrotra, N.; Verma, V.; Gupta, A.K.; Bhagwat, P.V.

2015-01-01

An ECR based Heavy Ion Accelerator comprising of a superconducting Electron Cyclotron Resonance (ECR) Ion Source, normal conducting RFQ (Radio Frequency Quadrupole) and superconducting Niobium resonators is being developed at BARC under XII plan. A state-of-the-art 18 GHz superconducting ECR ion source (PK-ISIS) jointly configured with Pantechnik, France is operational at Van-de-Graaff, BARC. The electromagnetic design of the improved version of 75 MHz heavy ion RFQ has been reported earlier. The previous thermal study of 51 cm RFQ model showed large temperature variation axially along the vane tip. A new coolant flow scheme has been worked out to optimize the axial temperature gradient. In this paper the thermal analysis including parametric study of coolant flow rates and inlet temperature variation will be presented. (author)

The KAERI 10 MeV Electron Linac - Description and Operational Manual

Energy Technology Data Exchange (ETDEWEB)

Lee, Byung Cheol; Park, Seong Hee; Jung, Young Uk; Han, Young Hwan; Kang, Hee Young

2005-06-15

The objective of this technical report is to guide the right operation and maintenance of the KAERI electron linac system. The KAERI electron linac system consists of 2 MeV injector based on 176 MHz Normal conducting RF (Radio Frequency)cavity and 10 MeV main accelerator based on 352 MHz Superconducting RF cavity, electron beamlines (injection and extraction). Since a electron accelerator generates hazard radiation, this system is located at the shielded room in basement and we can operate the system using the remote control system. It includes the description and the operational manual as well as the detailed technical direction for trouble shooting.

The KAERI 10 MeV Electron Linac - Description and Operational Manual

International Nuclear Information System (INIS)

Lee, Byung Cheol; Park, Seong Hee; Jung, Young Uk; Han, Young Hwan; Kang, Hee Young

2005-06-01

The objective of this technical report is to guide the right operation and maintenance of the KAERI electron linac system. The KAERI electron linac system consists of 2 MeV injector based on 176 MHz Normal conducting RF (Radio Frequency)cavity and 10 MeV main accelerator based on 352 MHz Superconducting RF cavity, electron beamlines (injection and extraction). Since a electron accelerator generates hazard radiation, this system is located at the shielded room in basement and we can operate the system using the remote control system. It includes the description and the operational manual as well as the detailed technical direction for trouble shooting

500 MHz transient digitizers based on GaAs CCDs

International Nuclear Information System (INIS)

Bryman, D.A.; Constable, M.; Cresswell, J.V.; Daviel, A.; LeNoble, M.; Mildenberger, J.; Poutissou, R.

1996-11-01

A system of 500 MHz transient digitizers based on gallium arsenide resistive gate charged coupled devices has been developed for an experiment studying rare K decays. CCDs with dynamic range of 8-bits and 128 or 320 pixels are used as analog pipelines. The CCD's are driven by a single phase transport system. Data readout and manipulation occurs at 15.6 MHz. (authors)

Multiplacting analysis on 650 MHz, BETA 0.61 superconducting RF LINAC cavity

International Nuclear Information System (INIS)

Seth, Sudeshna; Som, Sumit; Mandal, Aditya; Ghosh, Surajit; Saha, S.

2013-01-01

Design, analysis and development of high-β multi-cell elliptical shape Superconducting RF linac cavity has been taken up by VECC, Kolkata as a part of IIFC collaboration. The project aims to provide the-art technology achieving very high electric field gradient in superconducting linac cavity, which can be used in high energy high current proton linear accelerator to be built for ADSS/SNS programme in India and in Project-X at Fermilab, USA. The performance of this type of superconducting RF structure can be greatly affected due to multipacting when we feed power to the cavity. Multipacting is a phenomenon of resonant electron multiplication in which a large number of electrons build up an electron Avalanche which absorbs RF Energy leading to remarkable power losses and heating of the walls, making it impossible to raise the electric field by increasing the RF Power. Multipacting analysis has been carried out for 650 MHz, β=0.61, superconducting elliptical cavity using 2D code MultiPac 2.1 and 3 D code CST particle studio and the result is presented in this paper. (author)

Fully roll-to-roll gravure printed rectenna on plastic foils for wireless power transmission at 13.56 MHz.

Science.gov (United States)

Park, Hyejin; Kang, Hwiwon; Lee, Yonggil; Park, Yongsu; Noh, Jinsoo; Cho, Gyoujin

2012-08-31

Wireless power transmission to inexpensive and disposable smart electronic devices is one of the key issues for the realization of a ubiquitous society where sensor networks such as RFID tags, price tags, smart logos, signage and sensors could be fully interconnected and utilized by DC power of less than 0.3 W. This DC power can be provided by inductively coupled AC from a 13.56 MHz power transmitter through a rectenna, consisting of an antenna, a diode and a capacitor, which would be cheap to integrate with inexpensive smart electronic devices. To integrate the rectenna with a minimum cost, a roll-to-roll (R2R) gravure printing process has been considered to print the rectenna on plastic foils. In this paper, R2R gravure printing systems including printing condition and four different nanoparticle based inks will be reported to print the rectenna (antenna, diode and capacitor) on plastic foils at a printing speed of 8 m min(-1) and more than 90% device yield for a wireless power transmission of 0.3 W using a standard 13.56 MHz power transmitter.

GUIDELINES FOR EVALUATION OF PSYCHOLOGICAL AND PEDAGOGICAL QUALITY CHARACTERISTICS OF ELECTRONIC EDUCATIONAL RESOURCES

Directory of Open Access Journals (Sweden)

Galina P. Lavrentieva

2014-05-01

Full Text Available The article highlights the causes of insufficient effective use of electronic learning resources and sets out the guidelines on ways to solve the aforementioned problems. The set of didactic, methodical, psychological, pedagogical, design and ergonomic quality requirements is considered for evaluation, selection and application of information and communication technologies in the educational process. The most appropriate mechanisms for the ICT introduction into the learning process are disclosed as it should meet the specific learning needs of the student and the objectives of the educational process. The guidance for psycho-educational assessment of quality of electronic educational resources is provided. It is argued that the effectiveness of the ICT use is to be improved by means of quality evaluation mechanisms involved into the educational process.

27.12 MHz Radiofrequency Ablation for Benign Cutaneous Lesions

Directory of Open Access Journals (Sweden)

Dong Hyun Kim

2016-01-01

Full Text Available As surgical and/or ablative modalities, radiofrequency (RF has been known to produce good clinical outcomes in dermatology. Recently, 27.12 MHz RF has been introduced and has several advantages over conventional 4 or 6 MHz in terms of the precise ablation and lesser pain perception. We aimed to evaluate the clinical efficacy and safety of 27.12 MHz RF for the treatment of benign cutaneous lesions. Twenty female patient subjects were enrolled. Digital photography and a USB microscope camera were used to monitor the clinical results before one session of treatment with 27.12 MHz RF and after 1 and 3 weeks. Treated lesions included telangiectasias, cherry and spider angiomas, skin tags, seborrheic keratoses, lentigo, milium, dilated pore, acne, piercing hole, and one case of neurofibroma. For vascular lesions, clinical results were excellent for 33.3%, good for 44.4%, moderate for 11.1%, and poor for 11.1%. For nonvascular lesions (epidermal lesions and other benign cutaneous lesions, clinical results were excellent for 48.3%, good for 45.2%, moderate for 3.2%, and poor for 3.2%. No serious adverse events were observed. Mild adverse events reported were slight erythema, scale, and crust. The 27.12 MHz RF treatment of benign vascular and nonvascular lesions appears safe and effective after 3 weeks of follow-up.

500 MHz transient digitizers based on GaAs CCDs

Energy Technology Data Exchange (ETDEWEB)

Bryman, D A; Constable, M; Cresswell, J V; Daviel, A; LeNoble, M; Mildenberger, J; Poutissou, R

1996-11-01

A system of 500 MHz transient digitizers based on gallium arsenide resistive gate charged coupled devices has been developed for an experiment studying rare K decays. CCDs with dynamic range of 8-bits and 128 or 320 pixels are used as analog pipelines. The CCD`s are driven by a single phase transport system. Data readout and manipulation occurs at 15.6 MHz. (authors). 12 refs., 15 figs.

Availability, Use and Constraints to Use of Electronic Information Resources by Postgraduates Students at the University of Ibadan

Directory of Open Access Journals (Sweden)

Dare Samuel Adeleke

2017-12-01

Full Text Available Availability, awareness and use of electronic resources provide access to authoritative, reliable, accurate and timely access to information. The use of electronic information resources (EIRs can enable innovation in teaching and increase timeliness in research of postgraduate students which will eventual result into encouragement of the expected research-led enquiry in this digital age. The study adopted a descriptive survey design. Samples of 300 of postgraduate students within seven out 13 Faculties were randomly selected. Data were collected using questionnaire designed to elicit response from respondents and data were analyzed using descriptive statistics methods percentages, mean, and standard deviation. Results indicated that internet was ranked most available and used in the university. Low level of usage of electronic resources, in particular, full texts data bases is linked to a number of constraints: Interrupted power supply was ranked highest among other factors as speed and capacity of computers, retrieval of records with high recall and low precision, retrieving records relevant to information need, lack of knowledge of search techniques to retrieve information effectively, non possession of requisite IT skills and problems accessing the internet. The study recommended that usage of electronic resources be made compulsory, intensifying awareness campaigns concerning the availability, training on use of electronic resources and the problem of power outage be addressed.

Design of diode electron gun for 250 kW CW klystron

International Nuclear Information System (INIS)

Prasad, M.; Pande, S.A.; Hannurkar, P.R.

2005-01-01

A 250 kW CW klystron at frequencies 350 MHz and 700 MHz is being developed at Centre for Advanced Technology. These klystrons are required for forthcoming project like 100 MeV proton Linac for Spallation Neutron Source (SNS) as a main rf sources. In order to develop klystrons, we have designed the diode electron gun, which delivers more than 10 A beam current at 50 kV. This paper describes the simulation results of electron gun with computer code EGUN. (author)

A Study on Developing Evaluation Criteria for Electronic Resources in Evaluation Indicators of Libraries

Science.gov (United States)

Noh, Younghee

2010-01-01

This study aimed to improve the current state of electronic resource evaluation in libraries. While the use of Web DB, e-book, e-journal, and other e-resources such as CD-ROM, DVD, and micro materials is increasing in libraries, their use is not comprehensively factored into the general evaluation of libraries and may diminish the reliability of…

A ferroelectric electron gun in a free-electron maser experiment

International Nuclear Information System (INIS)

Einat, M.; Jerby, E.; Rosenman, G.

2002-01-01

An electron-gun based on a ferroelectric cathode is studied in a free-electron maser (FEM) experiment. In this gun, the electrons are separated from the cathode surface plasma, and are accelerated in two stages. The electron energy-spread is reduced sufficiently for an FEM operation in the microwave regime. A 14 keV, 1-2 A e-beam is obtained in a 0.1-2.1 μs pulse width. The pulse repetition frequency attains 3.1 MHz in ∼50% duty-cycle. This gun is implemented in an FEM oscillator experiment operating around 3 GHz. The paper presents experimental results and discusses the applicability of ferroelectric guns in free-electron laser devices

A ferroelectric electron gun in a free-electron maser experiment

CERN Document Server

Einat, M; Rosenman, G

2002-01-01

An electron-gun based on a ferroelectric cathode is studied in a free-electron maser (FEM) experiment. In this gun, the electrons are separated from the cathode surface plasma, and are accelerated in two stages. The electron energy-spread is reduced sufficiently for an FEM operation in the microwave regime. A 14 keV, 1-2 A e-beam is obtained in a 0.1-2.1 mu s pulse width. The pulse repetition frequency attains 3.1 MHz in approx 50% duty-cycle. This gun is implemented in an FEM oscillator experiment operating around 3 GHz. The paper presents experimental results and discusses the applicability of ferroelectric guns in free-electron laser devices.

Cryogenic systems for proof of the principle experiment of coherent electron cooling at RHIC

Energy Technology Data Exchange (ETDEWEB)

Huang, Yuenian; Belomestnykh, Sergey; Brutus, Jean Clifford; Lederle, Dewey; Orfin, Paul; Skaritka, John; Soria, Victor; Tallerico, Thomas; Than, Roberto [Collider Accelerator Department, Brookhaven National Laboratory, Upton, NY 11973 (United States)

2014-01-29

The Coherent electron Cooling (CeC) Proof of Principle (PoP) experiment is proposed to be installed in the Relativistic Heavy Ion Collider (RHIC) to demonstrate proton and ion beam cooling with this new technique that may increase the beam luminosity in certain cases, by as much as tenfold. Within the scope of this project, a 112 MHz, 2MeV Superconducting Radio Frequency (SRF) electron gun and a 704 MHz 20MeV 5-cell SRF cavity will be installed at IP2 in the RHIC ring. The superconducting RF electron gun will be cooled in a liquid helium bath at 4.4 K. The 704 MHz 5-cell SRF cavity will be cooled in a super-fluid helium bath at 2.0 K. This paper discusses the cryogenic systems designed for both cavities. For the 112 MHz cavity cryogenic system, a condenser/boiler heat exchanger is used to isolate the cavity helium bath from pressure pulses and microphonics noise sources. For the 704 MHz 5-cell SRF cavity, a heat exchanger is also used to isolate the SRF cavity helium bath from noise sources in the sub-atmospheric pumping system operating at room temperature. Detailed designs, thermal analyses and discussions for both systems will be presented in this paper.

Reduction of environmental MHz noise for SQUID application

Energy Technology Data Exchange (ETDEWEB)

Araya, T. [Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531 (Japan)]. E-mail: araya@sup.ee.es.osaka-u.ac.jp; Kitamura, Y. [Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531 (Japan); Kamishiro, M. [Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531 (Japan); Sakuta, K. [Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531 (Japan); Itozaki, H. [Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531 (Japan)]. E-mail: itozaki@ee.es.osaka-u.ac.jp

2006-10-01

It is important to remove large environmental noise in measurement using SQUIDs without magnetic shielding. Active noise control (ANC) is an effective method to remove the environmental noise. The environmental noise has been reduced by the ANC system in the radio frequency region around MHz. The anti-phase waves of the environmental noise should be generated by this system. The ANC system including the phase and amplitude control circuit was developed to make the anti-phase waves in the MHz region. In this paper, sinusoidal waves with a MHz frequency were used as the environmental noise. When a coil antenna was used for a receiver antenna, this ANC system suppressed these sinusoidal waves to the white noise level about 40 dB. When we used a SQUID as a receiver antenna, we also cancelled sinusoidal waves to the white noise level by this system. This shows that the ANC system is useful to reduce an environmental noise when this ANC system is developed to cancel multi-frequency noise.

Reduction of environmental MHz noise for SQUID application

International Nuclear Information System (INIS)

Araya, T.; Kitamura, Y.; Kamishiro, M.; Sakuta, K.; Itozaki, H.

2006-01-01

It is important to remove large environmental noise in measurement using SQUIDs without magnetic shielding. Active noise control (ANC) is an effective method to remove the environmental noise. The environmental noise has been reduced by the ANC system in the radio frequency region around MHz. The anti-phase waves of the environmental noise should be generated by this system. The ANC system including the phase and amplitude control circuit was developed to make the anti-phase waves in the MHz region. In this paper, sinusoidal waves with a MHz frequency were used as the environmental noise. When a coil antenna was used for a receiver antenna, this ANC system suppressed these sinusoidal waves to the white noise level about 40 dB. When we used a SQUID as a receiver antenna, we also cancelled sinusoidal waves to the white noise level by this system. This shows that the ANC system is useful to reduce an environmental noise when this ANC system is developed to cancel multi-frequency noise

Performance of an LPD prototype detector at MHz frame rates under Synchrotron and FEL radiation

Science.gov (United States)

Koch, A.; Hart, M.; Nicholls, T.; Angelsen, C.; Coughlan, J.; French, M.; Hauf, S.; Kuster, M.; Sztuk-Dambietz, J.; Turcato, M.; Carini, G. A.; Chollet, M.; Herrmann, S. C.; Lemke, H. T.; Nelson, S.; Song, S.; Weaver, M.; Zhu, D.; Meents, A.; Fischer, P.

2013-11-01

A MHz frame rate X-ray area detector (LPD — Large Pixel Detector) is under development by the Rutherford Appleton Laboratory for the European XFEL. The detector will have 1 million pixels and allows analogue storage of 512 images taken at 4.5 MHz in the detector front end. The LPD detector has 500 μm thick silicon sensor tiles that are bump bonded to a readout ASIC. The ASIC's preamplifier provides relatively low noise at high speed which results in a high dynamic range of 105 photons over an energy range of 5-20 keV. Small scale prototypes of 32 × 256 pixels (LPD 2-Tile detector) and 256 × 256 pixels (LPD supermodule detector) are now available for X-ray tests. The performance of prototypes of the detector is reported for first tests under synchrotron radiation (PETRA III at DESY) and Free-Electron-Laser radiation (LCLS at SLAC). The initial performance of the detector in terms of signal range and noise, radiation hardness and spatial and temporal response are reported. The main result is that the 4.5 MHz sampling detection chain is reliably working, including the analogue on-chip memory concept. The detector is at least radiation hard up to 5 MGy at 12 keV. In addition the multiple gain concept has been demonstrated over a dynamic range to 104 at 12 keV with a readout noise equivalent to < 1 photon rms in its most sensitive mode.

Fast wave at 433 MHz on FTU by a folded waveguide launcher

International Nuclear Information System (INIS)

Barbato, E.; De Marco, F.

1993-01-01

The use of fast wave (FW) power to interact directly with electrons is a useful tool for central heating of high density, high temperature plasmas and for electron current drive (CD). Direct electron heating by FW has been observed on JET and TFTR and, although FW absorption is weak at low β, successful electron heating and CD have been achieved on DIII-D at Te=2--3keV. The folded waveguide (FWG) is a promising new concept for ICRF launchers having the advantage of compact, rigid structure and very low impedence (E y /H z ) at the plasma edge. The FWG is particularly attractive for FTU since loop antennas suffer efficiency degradation at high frequency due to poloidal current decrease, whereas the RF flux coupled by a FWG is more poloidally uniform. Here we consider the possibility of injecting ∼ 1 MW of FW at 433 MHz into the FTU-Tokamak using the FWG as a launcher. Besides testing the FWG, and studying the FW electron heating regime, an other interesting issue of this experiment would be the study of possible sinergy between FW and the lower hybrid wave (LHW) at 8 GHz which is also available on FTU. The main parameters of FTU are a=30 cm, R 0 =90 cm, B T =4--8 T, I p e =0.4--2.0 10 14 cm -3

THE MODEL OF LINGUISTIC TEACHERS’ COMPETENCY DEVELOPMENT ON DESIGNING MULTIMEDIA ELECTRONIC EDUCATIONAL RESOURCES IN THE MOODLE SYSTEM

OpenAIRE

Anton M. Avramchuk

2017-01-01

The article is devoted to the problem of developing the competency of teachers of language disciplines on designing multimedia electronic educational resources in the Moodle system. The concept of "the competence of teachers of language disciplines on designing multimedia electronic educational resources in the Moodle system" is justified and defined. Identified and characterized the components by which the levels of the competency development of teachers of language disciplines on designing ...

Determining the level of awareness of the physicians in using the variety of electronic information resources and the effecting factors.

Science.gov (United States)

Papi, Ahmad; Ghazavi, Roghayeh; Moradi, Salimeh

2015-01-01

Understanding of the medical society's from the types of information resources for quick and easy access to information is an imperative task in medical researches and management of the treatment. The present study was aimed to determine the level of awareness of the physicians in using various electronic information resources and the factors affecting it. This study was a descriptive survey. The data collection tool was a researcher-made questionnaire. The study population included all the physicians and specialty physicians of the teaching hospitals affiliated to Isfahan University of Medical Sciences and numbered 350. The sample size based on Morgan's formula was set at 180. The content validity of the tool was confirmed by the library and information professionals and the reliability was 95%. Descriptive statistics were used including the SPSS software version 19. On reviewing the need of the physicians to obtain the information on several occasions, the need for information in conducting the researches was reported by the maximum number of physicians (91.9%) and the usage of information resources, especially the electronic resources, formed 65.4% as the highest rate with regard to meeting the information needs of the physicians. Among the electronic information databases, the maximum awareness was related to Medline with 86.5%. Among the various electronic information resources, the highest awareness (43.3%) was related to the E-journals. The highest usage (36%) was also from the same source. The studied physicians considered the most effective deterrent in the use of electronic information resources as being too busy and lack of time. Despite the importance of electronic information resources for the physician's community, there was no comprehensive knowledge of these resources. This can lead to less usage of these resources. Therefore, careful planning is necessary in the hospital libraries in order to introduce the facilities and full capabilities of the

Managing Selection for Electronic Resources: Kent State University Develops a New System to Automate Selection

Science.gov (United States)

Downey, Kay

2012-01-01

Kent State University has developed a centralized system that manages the communication and work related to the review and selection of commercially available electronic resources. It is an automated system that tracks the review process, provides selectors with price and trial information, and compiles reviewers' feedback about the resource. It…

End-of-life resource recovery from emerging electronic products

DEFF Research Database (Denmark)

Parajuly, Keshav; Habib, Komal; Cimpan, Ciprian

2016-01-01

Integrating product design with appropriate end-of-life (EoL) processing is widely recognized to have huge potentials in improving resource recovery from electronic products. In this study, we investigate both the product characteristics and EoL processing of robotic vacuum cleaner (RVC), as a case...... of emerging electronic product, in order to understand the recovery fate of different materials and its linkage to product design. Ten different brands of RVC were dismantled and their material composition and design profiles were studied. Another 125 RVCs (349 kg) were used for an experimental trial...... at a conventional ‘shred-and-separate’ type preprocessing plant in Denmark. A detailed material flow analysis was performed throughout the recycling chain. The results show a mismatch between product design and EoL processing, and the lack of practical implementation of ‘Design for EoL’ thinking. In the best...

47 CFR 80.303 - Watch on 156.800 MHz (Channel 16).

Science.gov (United States)

2010-10-01

... Section 80.303 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES STATIONS IN THE MARITIME SERVICES Safety Watch Requirements and Procedures Coast Station Safety... maintain a safety watch on the frequency 156.800 MHz except when transmitting on 156.800 MHz. (b) A coast...

The detection of prostatic carcinoma. 4- or 7-MHz transrectal ultrasonography?

NARCIS (Netherlands)

Vleeming, R.; Noordzij, J. W.; de Reijke, T. M.; Kurth, K. H.

1993-01-01

In this prospective study a comparison of 4-versus 7-MHz transrectal ultrasonography for the detection of prostatic carcinoma is reported. A total of 150 prostates were biopsied due to suspicion of malignancy arising at either digital rectal examination, 4- and/or 7-MHz transrectal ultrasonography,

Use of electronic sales data to tailor nutrition education resources for an ethnically diverse population.

Science.gov (United States)

Eyles, H; Rodgers, A; Ni Mhurchu, C

2010-02-01

Nutrition education may be most effective when personally tailored. Individualised electronic supermarket sales data offer opportunities to tailor nutrition education using shopper's usual food purchases. The present study aimed to use individualised electronic supermarket sales data to tailor nutrition resources for an ethnically diverse population in a large supermarket intervention trial in New Zealand. Culturally appropriate nutrition education resources (i.e. messages and shopping lists) were developed with the target population (through two sets of focus groups) and ethnic researchers. A nutrient database of supermarket products was developed using retrospective sales data and linked to participant sales to allow tailoring by usual food purchases. Modified Heart Foundation Tick criteria were used to identify 'healthier' products in the database suitable for promotion in the resources. Rules were developed to create a monthly report listing the tailored and culturally targeted messages to be sent to each participant, and to produce automated, tailored shopping lists. Culturally targeted nutrition messages (n = 864) and shopping lists (n = 3 formats) were developed. The food and nutrient database (n = 3000 top-selling products) was created using 12 months of retrospective sales data, and comprised 60%'healthier' products. Three months of baseline sales data were used to determine usual food purchases. Tailored resources were successfully mailed to 123 Māori, 52 Pacific and 346 non-Māori non-Pacific participants over the 6-month trial intervention period. Electronic supermarket sales data can be used to tailor nutrition education resources for a large number of ethnically diverse supermarket shoppers.

Electromagnetic radiation-2450 MHz exposure causes cognition ...

Indian Academy of Sciences (India)

83

Electromagnetic radiation-2450 MHz exposure causes cognition deficit with mitochondrial. 1 ... decrease in levels of acetylcholine, and increase in activity of acetyl ...... neuronal apoptosis and cognitive disturbances in sevoflurane or propofol ...

Design, Fabrication and Testing of Medium-Beta 650 MHz SRF Cavity Prototypes for Project-X

International Nuclear Information System (INIS)

Marhauser, F.; Clemens, W.A.; Henry, J.; Kneisel, P.; Martin, R.; Rimmer, R.A.; Slack, G.; Turlington, L.; Williams, R.S.

2011-01-01

A new type of superconducting radio frequency (SRF) cavity shape with a shallow equator dome to reduce electron impact energies for suppressing multipacting barriers has been proposed. The shape is in consideration for the first time in the framework of Project-X to design a potential multi-cell cavity candidate for the medium-beta section of the SRF proton CW linac operating at 650 MHz. Rationales covering the design of the multi-cell cavity, the manufacture, post-processing and high power testing of two single-cell prototypes are presented.

Frequency Arrangement For 700 MHz Band

Directory of Open Access Journals (Sweden)

Ancans G.

2015-02-01

Full Text Available The 694-790 MHz (700 MHz band was allocated by the 2012 World Radiocommunication Conference (WRC-12 in ITU Region 1 (Europe included, to the mobile service on a co-primary basis with other services to which this band was allocated on the primary basis and identified for the International Mobile Telecommunications (IMT. At the same time, the countries of Region 1 will be able also to continue using these frequencies for their broadcasting services if necessary. This allocation will be effective immediately after 2015 World Radiocommunication Conference (WRC-15. In order to make the best possible use of this frequency band for mobile service, a worldwide harmonized frequency arrangement is to be prepared to allow for large economies of scale and international roaming as well as utilizing the available spectrum in the best possible way, minimizing possible interference between services, facilitating deployment and cross-border coordination. The authors analyze different possible frequency arrangements and conclude on the frequency arrangement most suitable for Europe.

Availability, Level of Use and Constraints to Use of Electronic Resources by Law Lecturers in Public Universities in Nigeria

Science.gov (United States)

Amusa, Oyintola Isiaka; Atinmo, Morayo

2016-01-01

(Purpose) This study surveyed the level of availability, use and constraints to use of electronic resources among law lecturers in Nigeria. (Methodology) Five hundred and fifty-two law lecturers were surveyed and four hundred and forty-two responded. (Results) Data analysis revealed that the level of availability of electronic resources for the…

A systematic review of portable electronic technology for health education in resource-limited settings.

Science.gov (United States)

McHenry, Megan S; Fischer, Lydia J; Chun, Yeona; Vreeman, Rachel C

2017-08-01

The objective of this study is to conduct a systematic review of the literature of how portable electronic technologies with offline functionality are perceived and used to provide health education in resource-limited settings. Three reviewers evaluated articles and performed a bibliography search to identify studies describing health education delivered by portable electronic device with offline functionality in low- or middle-income countries. Data extracted included: study population; study design and type of analysis; type of technology used; method of use; setting of technology use; impact on caregivers, patients, or overall health outcomes; and reported limitations. Searches yielded 5514 unique titles. Out of 75 critically reviewed full-text articles, 10 met inclusion criteria. Study locations included Botswana, Peru, Kenya, Thailand, Nigeria, India, Ghana, and Tanzania. Topics addressed included: development of healthcare worker training modules, clinical decision support tools, patient education tools, perceptions and usability of portable electronic technology, and comparisons of technologies and/or mobile applications. Studies primarily looked at the assessment of developed educational modules on trainee health knowledge, perceptions and usability of technology, and comparisons of technologies. Overall, studies reported positive results for portable electronic device-based health education, frequently reporting increased provider/patient knowledge, improved patient outcomes in both quality of care and management, increased provider comfort level with technology, and an environment characterized by increased levels of technology-based, informal learning situations. Negative assessments included high investment costs, lack of technical support, and fear of device theft. While the research is limited, portable electronic educational resources present promising avenues to increase access to effective health education in resource-limited settings, contingent

78 FR 28749 - Private Land Mobile Radio Stations Below 800 MHz

Science.gov (United States)

2013-05-16

... these proposals, with the exception of those issues relating to Wireless Medical Telemetry Services... accomplished in the PLMR bands below 800 MHz. A trunked radio system employs technology that can search two or... prohibited by Sec. 1.935). We also take this opportunity to correct the 800 MHz band trunking rules to set...

Doppler electron velocimetry : notes on creating a practical tool.

Energy Technology Data Exchange (ETDEWEB)

Reu, Phillip L.; Milster, Tom (University of Arizona)

2008-11-01

The Doppler electron velocimeter (DEV) has been shown to be theoretically possible. This report attempts to answer the next logical question: Is it a practical instrument? The answer hinges upon whether enough electrons are available to create a time-varying Doppler current to be measured by a detector with enough sensitivity and bandwidth. The answer to both of these questions is a qualified yes. A target Doppler frequency of 1 MHz was set as a minimum rate of interest. At this target a theoretical beam current signal-to-noise ratio of 25-to-1 is shown for existing electron holography equipment. A detector is also demonstrated with a bandwidth of 1-MHz at a current of 10 pA. Additionally, a Linnik-type interferometer that would increase the available beam current is shown that would offer a more flexible arrangement for Doppler electron measurements over the traditional biprism.

SAGES: a suite of freely-available software tools for electronic disease surveillance in resource-limited settings.

Directory of Open Access Journals (Sweden)

Sheri L Lewis

Full Text Available Public health surveillance is undergoing a revolution driven by advances in the field of information technology. Many countries have experienced vast improvements in the collection, ingestion, analysis, visualization, and dissemination of public health data. Resource-limited countries have lagged behind due to challenges in information technology infrastructure, public health resources, and the costs of proprietary software. The Suite for Automated Global Electronic bioSurveillance (SAGES is a collection of modular, flexible, freely-available software tools for electronic disease surveillance in resource-limited settings. One or more SAGES tools may be used in concert with existing surveillance applications or the SAGES tools may be used en masse for an end-to-end biosurveillance capability. This flexibility allows for the development of an inexpensive, customized, and sustainable disease surveillance system. The ability to rapidly assess anomalous disease activity may lead to more efficient use of limited resources and better compliance with World Health Organization International Health Regulations.

Use and Cost of Electronic Resources in Central Library of Ferdowsi University Based on E-metrics

Directory of Open Access Journals (Sweden)

Mohammad Reza Davarpanah

2012-07-01

Full Text Available The purpose of this study was to investigate the usage of electronic journals in Ferdowsi University, Iran based on e-metrics. The paper also aimed to emphasize the analysis of cost-benefit and the correlation between the journal impact factors and the usage data. In this study experiences of Ferdowsi University library on licensing and usage of electronic resources was evaluated by providing a cost-benefit analysis based on the cost and usage statistics of electronic resources. Vendor-provided data were also compared with local usage data. The usage data were collected by tracking web-based access locally, and by collecting vender-provided usage data. The data sources were one-year of vendor-supplied e-resource usage data such as Ebsco, Elsevier, Proquest, Emerald, Oxford and Springer and local usage data collected from the Ferdowsi university web server. The study found that actual usage values differ for vendor-provided data and local usage data. Elsevier has got the highest usage degree in searches, sessions and downloads. Statistics also showed that a small number of journals satisfy significant amount of use while the majority of journals were used less frequent and some were never used at all. The users preferred the PDF rather than HTML format. The data in subject profile suggested that the provided e-resources were best suited to certain subjects. There was no correlation between IF and electronic journal use. Monitoring the usage of e-resources gained increasing importance for acquisition policy and budget decisions. The article provided information about local metrics for the six surveyed vendors/publishers, e.g. usage trends, requests per package, cost per use as related to the scientific specialty of the university.

Electron paramagnetic resonance and electron-nuclear double resonance study of the neutral copper acceptor in ZnGeP sub 2 crystals

CERN Document Server

Stevens, K T; Setzler, S D; Schünemann, P G; Pollak, T M

2003-01-01

Electron paramagnetic resonance (EPR) and electron-nuclear double resonance have been used to characterize the neutral copper acceptor in ZnGeP sub 2 crystals. The copper substitutes for zinc and behaves as a conventional acceptor (i.e. the 3d electrons do not play a dominant role). Because of a high degree of compensation from native donors, the copper acceptors in our samples were initially in the nonparamagnetic singly ionized state (Cu sub Z sub n sup -). The paramagnetic neutral state (Cu sub Z sub n sup 0) was observed when the crystals were exposed to 632.8 nm or 1064 nm laser light while being held at a temperature below 50 K. The g matrix of the neutral copper acceptor is axial g sub p sub a sub r = 2.049 and g sub p sub e sub r sub p = 2.030), with the unique principal direction parallel to the tetragonal c axis of the crystal. The hyperfine and nuclear quadrupole matrices also exhibit c-axis symmetry (A sub p sub a sub r = 87.6 MHz, A sub p sub e sub r sub p = 34.8 MHz and P = 0.87 MHz for sup 6 su...

Research on the electromagnetic radiation characteristics of the gas main switch of a capacitive intense electron-beam accelerator

Directory of Open Access Journals (Sweden)

Yongfeng Qiu

2017-11-01

Full Text Available Strong electromagnetic fields are radiated during the operation of the intense electron-beam accelerator (IEBA, which may lead to the nearby electronic devices out of order. In this paper, the research on the electromagnetic radiation characteristic of the gas main switch of a capacitive IEBA is carried out by the methods of theory analysis and experiment investigation. It is obtained that the gas main switch is the dominating radiation resource. In the absence of electromagnetic shielding for the gas main switch, when the pulse forming line of the IEBA is charged to 700 kV, the radiation field with amplitude of 3280 V/m, dominant frequency of 84 MHz and high frequency 100 MHz is obtained at a distance of 10 meters away from the gas main switch. The experimental results of the radiation field agree with the theoretical calculations. We analyze the achievements of several research groups and find that there is a relationship between the rise time (T of the transient current of the gas main switch and the dominant frequency (F of the radiation field, namely, F*T=1. Contrast experiment is carried out with a metal shield cover for the gas main switch. Experimental results show that for the shielded setup the radiation field reduces to 115 V/m, the dominant frequency increases to 86.5 MHz at a distance of 10 away meters from the gas main switch. These conclusions are beneficial for further research on the electromagnetic radiation and protection of the IEBA.

The producing of an ECR plasma using 2450MHz Whistler Wave and the investigating of its parameters

International Nuclear Information System (INIS)

Fang Yude; Zhang Jiande; Fu Keming; Lu Xiangyu; Liu Dengcheng; Wang Xianyu; Xie Weidong; Bao Dinghua; Yin Xiejin

1988-12-01

A stable ECR plasma was produced and sustained in HER mirror using 2450MHz Whistler wave. The parameters of the ECR plasma and their chaining characters were studied in detail and were compared with those of the DC discharge plasmas. The conclusion is that the ECR plasma is a high ionizability, low temperature, middle density plasma, its peak density may much exceed the cutoff density of the pump wave (when ω = ω pe ) and arrive at the order of 10 12 cm -3 . The ECR plasma includes some high energy hot electrons (20Kev-200Kev) and middle energy warm electrons (< 20Kev). Those two kinds of electron created some strong X-ray emissions in a wide frequency range. The ECR plasma has higher edge density and can strongly interact with the wall. (author). 9 refs, 17 figs

Building and Managing Electronic Resources in Digital Era in India with Special Reference to IUCAA and NIV, Pune: A Comparative Case Study

Science.gov (United States)

Sahu, H. K.; Singh, S. N.

2015-04-01

This paper discusses and presents a comparative case study of two libraries in Pune, India, Inter-University Centre for Astronomy and Astrophysics and Information Centre and Library of National Institute of Virology (Indian Council of Medical Research). It compares how both libraries have managed their e-resource collections, including acquisitions, subscriptions, and consortia arrangements, while also developing a collection of their own resources, including pre-prints and publications, video lectures, and other materials in an institutional repository. This study illustrates how difficult it is to manage electronic resources in a developing country like India, even though electronic resources are used more than print resources. Electronic resource management can be daunting, but with a systematic approach, various problems can be solved, and use of the materials will be enhanced.

Electron heating mode transition induced by mixing radio frequency and ultrahigh frequency dual frequency powers in capacitive discharges

International Nuclear Information System (INIS)

Sahu, B. B.; Han, Jeon G.

2016-01-01

Electron heating mode transitions induced by mixing the low- and high-frequency power in dual-frequency nitrogen discharges at 400 mTorr pressure are presented. As the low-frequency (13.56 MHz) power decreases and high-frequency (320 MHz) power increases for the fixed power of 200 W, there is a transition of electron energy distribution function (EEDF) from Druyvesteyn to bi-Maxwellian type characterized by a distinguished warm electron population. It is shown that this EEDF evolution is attributed to the transition from collisional to collisionless stochastic heating of the low-energy electrons.

Compact high efficiency, light weight 200-800 MHz high power RF source

International Nuclear Information System (INIS)

Shrader, M.B.; Preist, D.H.

1985-01-01

There has long been a need for a new more efficient less bulky high power RF power source to drive accelerators in the 200 to 800 MHz region. Results on a recent 5-year EIMAC sponsored R and D program which have lead to the introduction of the Klystrode for UHF television and troposcatter applications indicate that at power levels of 1MW or more efficiencies in excess of 75% can be obtained at 450 MHz. Efficiencies of this order coupled with potential size and weight parameters which are a fraction of those of existing high power UHF generators open up new applications which heretofore would have been impractical if not impossible. Measurements at 470 MHz on existing Klystrodes are given. Projected operating conditions for a 1MW 450 MHz Klystrode having an overall length of 60 inches and a total tube, circuit, and magnet weight of 250 pounds is presented

Impact of foliage on LoRa 433MHz propagation in tropical environment

Science.gov (United States)

Ahmad, Khairol Amali; Salleh, Mohd Sharil; Segaran, Jivitraa Devi; Hashim, Fakroul Ridzuan

2018-02-01

LoRa is being considered as one of the promising system for Low-Power-Wide-Area-Network (LPWAN) to support the growth of Internet of Things (IoT) applications. Designed to operate in the industrial, scientific and medical (ISM) bands, LoRa had been tested and evaluated mainly in Europe and US in the 868 MHz and 915 MHz modulation bands. Using chirp spread spectrum technology, LoRa is expected to be robust against degredation. This paper provides some early results in the performance of LoRa signal propagation of 433 MHz modulation in tropical foliage environments.

47 CFR 22.970 - Unacceptable interference to part 90 non-cellular 800 MHz licensees from cellular radiotelephone...

Science.gov (United States)

2010-10-01

...-cellular 800 MHz licensees from cellular radiotelephone or part 90-800 MHz cellular systems. 22.970 Section... MOBILE SERVICES Cellular Radiotelephone Service § 22.970 Unacceptable interference to part 90 non-cellular 800 MHz licensees from cellular radiotelephone or part 90-800 MHz cellular systems. (a) Definition...

Frequency-agile gyrotron for electron decoupling and pulsed dynamic nuclear polarization

Science.gov (United States)

Scott, Faith J.; Saliba, Edward P.; Albert, Brice J.; Alaniva, Nicholas; Sesti, Erika L.; Gao, Chukun; Golota, Natalie C.; Choi, Eric J.; Jagtap, Anil P.; Wittmann, Johannes J.; Eckardt, Michael; Harneit, Wolfgang; Corzilius, Björn; Th. Sigurdsson, Snorri; Barnes, Alexander B.

2018-04-01

We describe a frequency-agile gyrotron which can generate frequency-chirped microwave pulses. An arbitrary waveform generator (AWG) within the NMR spectrometer controls the microwave frequency, enabling synchronized pulsed control of both electron and nuclear spins. We demonstrate that the acceleration of emitted electrons, and thus the microwave frequency, can be quickly changed by varying the anode voltage. This strategy results in much faster frequency response than can be achieved by changing the potential of the electron emitter, and does not require a custom triode electron gun. The gyrotron frequency can be swept with a rate of 20 MHz/μs over a 670 MHz bandwidth in a static magnetic field. We have already implemented time-domain electron decoupling with dynamic nuclear polarization (DNP) magic angle spinning (MAS) with this device. In this contribution, we show frequency-swept DNP enhancement profiles recorded without changing the NMR magnet or probe. The profile of endofullerenes exhibits a DNP profile with a <10 MHz linewidth, indicating that the device also has sufficient frequency stability, and therefore phase stability, to implement pulsed DNP mechanisms such as the frequency-swept solid effect. We describe schematics of the mechanical and vacuum construction of the device which includes a novel flanged sapphire window assembly. Finally, we discuss how commercially available continuous-wave gyrotrons can potentially be converted into similar frequency-agile high-power microwave sources.

318-MHz variability of complete samples of extragalactic radio sources. II

International Nuclear Information System (INIS)

Dennison, B.; Broderick, J.J.; Ledden, J.E.; O'Dell, S.L.; Condon, J.J.

1981-01-01

We report the remainder of two- and three-epoch 318-MHz observations of extragalactic sources in samples complete to 3 Jy at 1400 MHz and 1 Jy at 5000 MHz. From analysis of this low-frequency variability survey, we find that steep-spectrum (α> or =0.5) sources do not appear to vary, but about 40% of all flat-spectrum (α<0.5) sources exhibit low-frequency variability exceeding 8% over approx.5 yr. Among the flat-spectrum sources, those with inverted spectra show the largest fractional variations. We also find that the incidence of low-frequency variability is strongly correlated with the determination that a source is an optically violent variable. These statistical properties are consistent with models invoking relativistic beaming of radio and optical emission

Niobium thin film coating on a 500-MHz copper cavity by plasma deposition

Energy Technology Data Exchange (ETDEWEB)

Haipeng Wang; Genfa Wu; H. Phillips; Robert Rimmer; Anne-Marie Valente; Andy Wu

2005-05-16

A system using an Electron Cyclotron Resonance (ECR) plasma source for the deposition of a thin niobium film inside a copper cavity for superconducting accelerator applications has been designed and is being constructed. The system uses a 500-MHz copper cavity as both substrate and vacuum chamber. The ECR plasma will be created to produce direct niobium ion deposition. The central cylindrical grid is DC biased to control the deposition energy. This paper describes the design of several subcomponents including the vacuum chamber, RF supply, biasing grid and magnet coils. Operational parameters are compared between an operating sample deposition system and this system. Engineering work progress toward the first plasma creation will be reported here.

Crosstalk Models for Short VDSL2 Lines from Measured 30 MHz Data

Directory of Open Access Journals (Sweden)

Leshem A

2006-01-01

Full Text Available In recent years, there has been a growing interest in hybrid fiber-copper access solutions, as in fiber to the basement (FTTB and fiber to the curb/cabinet (FTTC. The twisted pair segment in these architectures is in the range of a few hundred meters, thus supporting transmission over tens of MHz. This paper provides crosstalk models derived from measured data for quad cable, lengths between 75 and 590 meters, and frequencies up to MHz. The results indicate that the log-normal statistical model (with a simple parametric law for the frequency-dependent mean fits well up to MHz for both FEXT and NEXT. This extends earlier log-normal statistical modeling and validation results for NEXT over bandwidths in the order of a few MHz. The fitted crosstalk power spectra are useful for modem design and simulation. Insertion loss, phase, and impulse response duration characteristics of the direct channels are also provided.

[Use of internet and electronic resources among Spanish intensivist physicians. First national survey].

Science.gov (United States)

Gómez-Tello, V; Latour-Pérez, J; Añón Elizalde, J M; Palencia-Herrejón, E; Díaz-Alersi, R; De Lucas-García, N

2006-01-01

Estimate knowledge and use habits of different electronic resources in a sample of Spanish intensivists: Internet, E-mail, distribution lists, and use of portable electronic devices. Self-applied questionnaire. A 50-question questionnaire was distributed among Spanish intensivists through the hospital marketing delegates of a pharmaceutical company and of electronic forums. A total of 682 questionnaires were analyzed (participation: 74%). Ninety six percent of those surveyed used Internet individually: 67% admitted training gap. Internet was the second source of clinical consultations most used (61%), slightly behind consultation to colleagues (65%). The pages consulted most were bibliographic databases (65%) and electronic professional journals (63%), with limited use of Evidence Based Medicine pages (19%). Ninety percent of those surveyed used e-mail regularly in the practice of their profession, although 25% admitted that were not aware of its possibilities. The use of E-mail decreased significantly with increase in age. A total of 62% of the intensivists used distribution lists. Of the rest, 42% were not aware of its existence and 32% admitted they had insufficient training to handle them. Twenty percent of those surveyed had portable electronic devices and 64% considered it useful, basically due to its rapid consultation at bedside. Female gender was a negative predictive factor of its use (OR 0.35; 95% CI 0.2-0.63; p=0.0002). A large majority of the Spanish intensivists use Internet and E-mail. E-mail lists and use of portable devices are still underused resources. There are important gaps in training and infrequent use of essential pages. There are specific groups that require directed educational policies.

Model of e-learning with electronic educational resources of new generation

OpenAIRE

A. V. Loban; D. A. Lovtsov

2017-01-01

Purpose of the article: improving of scientific and methodical base of the theory of the е-learning of variability. Methods used: conceptual and logical modeling of the е-learning of variability process with electronic educational resource of new generation and system analysis of the interconnection of the studied subject area, methods, didactics approaches and information and communication technologies means. Results: the formalization complex model of the е-learning of variability with elec...

Early 500 MHz prototype LEP RF Cavity with superposed storage cavity

CERN Multimedia

CERN PhotoLab

1981-01-01

The principle of transferring the RF power back and forth between the accelerating cavity and a side-coupled storage cavity was demonstrated with this 500 MHz prototype. In LEP, the accelerating frequency was 352.2 MHz, and accelerating and storage cavities were consequently larger. See also 8002294, 8006061, 8407619X, and Annual Reports 1980, p.115; 1981, p.95; 1985, vol.I, p.13.

Impact of Knowledge Resources Linked to an Electronic Health Record on Frequency of Unnecessary Tests and Treatments

Science.gov (United States)

Goodman, Kenneth; Grad, Roland; Pluye, Pierre; Nowacki, Amy; Hickner, John

2012-01-01

Introduction: Electronic knowledge resources have the potential to rapidly provide answers to clinicians' questions. We sought to determine clinicians' reasons for searching these resources, the rate of finding relevant information, and the perceived clinical impact of the information they retrieved. Methods: We asked general internists, family…

Electronic Document Management: A Human Resource Management Case Study

Directory of Open Access Journals (Sweden)

Thomas Groenewald

2004-11-01

Full Text Available This case study serve as exemplar regarding what can go wrong with the implementation of an electronic document management system. Knowledge agility and knowledge as capital, is outlined against the backdrop of the information society and knowledge economy. The importance of electronic document management and control is sketched thereafter. The literature review is concluded with the impact of human resource management on knowledge agility, which includes references to the learning organisation and complexity theory. The intervention methodology, comprising three phases, follows next. The results of the three phases are presented thereafter. Partial success has been achieved with improving the human efficacy of electronic document management, however the client opted to discontinue the system in use. Opsomming Die gevalle studie dien as voorbeeld van wat kan verkeerd loop met die implementering van ’n elektroniese dokumentbestuur sisteem. Teen die agtergrond van die inligtingsgemeenskap en kennishuishouding word kennissoepelheid en kennis as kapitaal bespreek. Die literatuurstudie word afgesluit met die inpak van menslikehulpbronbestuur op kennissoepelheid, wat ook die verwysings na die leerorganisasie en kompleksietydsteorie insluit. Die metodologie van die intervensie, wat uit drie fases bestaan, volg daarna. Die resultate van die drie fases word vervolgens aangebied. Slegs gedeelte welslae is behaal met die verbetering van die menslike doeltreffendheid ten opsigte van elektroniese dokumentbestuur. Die klient besluit egter om nie voort te gaan om die huidige sisteem te gebruik nie.

The LANSCE 805 MHZ RF System History and Status

CERN Document Server

Lynch, Michael; Tallerico, Paul J

2005-01-01

The Los Alamos Neutron Science Center (LANSCE) linear accelerator runs at 201.25 MHz for acceleration to 100 MeV. The remainder of the acceleration to 800 MeV is at 805 MHz. This is done with 44 accelerator cavity stages driven by 805 MHz klystrons. Each klystron has a peak power capability of 1.25 MeV. Originally, 97 klystrons were purchased, which was 70 from Varian/CPI and 27 from Litton. The 44 RF systems are laid out in sectors with either 6 or 7 klystrons per sector. The klystrons in each sector are powered from a common HV sytem. The current arrangement uses the Varian/CPI klystrons in 6 of the 7 sectors and Litton klystrons in the remaining sector. With that arrangement there are 38 CPI klystrons installed and 1 spare klystron per sector and 6 Litton klystrons installed in the final sector with 2 spares. The current average life of all of the operating and spare klystrons (52 total) is >112,000 filament hours and >93,000 HV hours. That is three times the typical klystron lifetime today f...

Challenges in the implementation of an electronic surveillance system in a resource-limited setting: Alerta, in Peru

Directory of Open Access Journals (Sweden)

Soto Giselle

2008-11-01

Full Text Available Abstract Background Infectious disease surveillance is a primary public health function in resource-limited settings. In 2003, an electronic disease surveillance system (Alerta was established in the Peruvian Navy with support from the U.S. Naval Medical Research Center Detachment (NMRCD. Many challenges arose during the implementation process, and a variety of solutions were applied. The purpose of this paper is to identify and discuss these issues. Methods This is a retrospective description of the Alerta implementation. After a thoughtful evaluation according to the Centers for Disease Control and Prevention (CDC guidelines, the main challenges to implementation were identified and solutions were devised in the context of a resource-limited setting, Peru. Results After four years of operation, we have identified a number of challenges in implementing and operating this electronic disease surveillance system. These can be divided into the following categories: (1 issues with personnel and stakeholders; (2 issues with resources in a developing setting; (3 issues with processes involved in the collection of data and operation of the system; and (4 issues with organization at the central hub. Some of the challenges are unique to resource-limited settings, but many are applicable for any surveillance system. For each of these challenges, we developed feasible solutions that are discussed. Conclusion There are many challenges to overcome when implementing an electronic disease surveillance system, not only related to technology issues. A comprehensive approach is required for success, including: technical support, personnel management, effective training, and cultural sensitivity in order to assure the effective deployment of an electronic disease surveillance system.

Cell death induced by GSM 900-MHz and DCS 1800-MHz mobile telephony radiation

International Nuclear Information System (INIS)

Panagopoulos, D. J; Chavdoula, E. D.; Nezis, I. P.; Margaritis, L. H.

2007-01-01

In the present study, the TUNEL (Terminal deoxynucleotide transferase dUTP Nick End Labeling) assay '' a well known technique widely used for detecting fragmented DNA in various types of cells'' was used to detect cell death (DNA fragmentation) in a biological model, the early and mid stages of oogenesis of the insect Drosophila melanogaster. The flies were exposed in vivo to either GSM 900-MHz (Global System for Mobile telecommunications) or DCS 1800-MHz (Digital Cellular System) radiation from a common digital mobile phone, for few minutes per day during the first 6 days of their adult life. The exposure conditions were similar to those to which a mobile phone user is exposed, and were determined according to previous studies of ours [D.J. Panagopoulos, A. Karabarbounis, L.H. Margaritis, Effect of GSM 900-MHz mobile phone radiation on the reproductive capacity of D. melanogaster, Electromagn. Biol. Med. 23 (1) (2004) 29''43; D.J. Panagopoulos, N. Messini, A. Karabarbounis, A.L. Philippetis, L.H. Margaritis, Radio frequency electromagnetic radiation within ''safety levels'' alters the physiological function of insects, in: P. Kostarakis, P. Stavroulakis (Eds.), Proceedings of the Millennium International Workshop on Biological Effects of Electromagnetic Fields, Heraklion, Crete, Greece, October 17''20, 2000, pp. 169''175, ISBN: 960-86733-0-5; D.J. Panagopoulos, L.H. Margaritis, Effects of electromagnetic fields on the reproductive capacity of D. melanogaster, in: P. Stavroulakis (Ed.), Biological Effects of Electromagnetic Fields, Springer, 2003, pp. 545''578], which had shown a large decrease in the oviposition of the same insect caused by GSM radiation. Our present results suggest that the decrease in oviposition previously reported, is due to degeneration of large numbers of egg chambers after DNA fragmentation of their constituent cells, induced by both types of mobile telephony radiation. Induced cell death is recorded for the first time, in all types of

SIMULTANEOUS OBSERVATIONS OF GIANT PULSES FROM PULSAR PSR B0031-07 AT 38 AND 74 MHz

Energy Technology Data Exchange (ETDEWEB)

Tsai, Jr-Wei; Simonetti, John H.; Bear, Brandon [Department of Physics, Virginia Tech, Blacksburg, VA 24061 (United States); Gough, Jonathan D. [Department of Chemistry, Lehman College, CUNY, Bronx, NY 10468 (United States); Newton, Joseph R. [Department of Chemistry and Physics, Augusta University, Augusta, GA 30912 (United States); Kavic, Michael [Department of Physics, Long Island University, Brooklyn, NY 11201 (United States)

2016-03-15

The first station of the Long Wavelength Array was used to study PSR B0031-07 with simultaneous observations at 38 and 74 MHz. We found that 158 (0.35%) of the observed pulses at 38 MHz and 221 (0.49%) of the observed pulses at 74 MHz qualified as giant pulses (GPs) in a total of 12 hr of observations. GPs are defined as having flux densities of a factor of ≥90 times that of an average pulse (AP) at 38 MHz and ≥80 times that of an AP at 74 MHz. The cumulative distribution of pulse strength follows a power law, with an index of −4.2 at 38 MHz and −4.9 at 74 MHz. This distribution has a much more gradual slope than would be expected if observing the tail of a Gaussian distribution of normal pulses. The dispersion measure (DM) value which resulted in the largest signal to noise for dedispersed pulses was DM = 10.9 pc cm{sup −3}. No other transient pulses were detected in the data in the wide DM range from 1 to 5000 pc cm{sup −3}. There were 12 GPs detected within the same period from both 38 and 74 MHz, meaning that the majority of them are not generated in a wide band.

Electron diode oscillators for high-power RF generation

International Nuclear Information System (INIS)

Humphries, S.

1989-01-01

Feedback oscillators have been used since the invention of the vacuum tube. This paper describes the extension of these familiar circuits to the regime of relativistic electron beam diodes. Such devices have potential application for the generation of high power RF radiation in the range 50-250 MHz, 1-10 GW with 20-60% conversion efficiency. This paper reviews the theory of the oscillator and the results of a design study. Calculations for the four-electrode diode with EGUN and EBQ show that good modulations of 30 kA electron beam at 600 kV can be achieved with moderate field stress on the electrodes. Conditions for oscillation have been studied with an in-house transmission line code. A design for a 7.5 GW oscillator at 200 MHz with 25% conversion efficiency is presented

Cellular responses to 836 MHz and 1,765 GHz CDMA radiations

International Nuclear Information System (INIS)

Park, Woong Yang; Seo, Jeong Sun; Paik, Jung Ki; Lim, Kye Jae; Yoon, Hyun Bo

2002-01-01

The effect of radiofrequency (RF) radiation in the cellular phone communication range (836.5 MHz and 1.765 GHz code division multiple access, CDMA) on tumorigenesis and other health effect was measured using the in vitro cell culture system. To determine whether 836.5 MHz or 1.765 GHz CDMA radiations have any genotoxic effects to induce neoplastic transformation, C3H 10T1/2 cells were exposed to either of the above radiations at a specific absorption rate (SAR) of 35.6W/Kg (836.5 MHz) and 38.2 W/kg(1.765 GHz) or sham- exposed at the same time for 7 days. Cells were maintained in incubators and refed with fresh growth medium every 3 days. At this SAR, radiofrequency radiation did not induce neoplastic transformation in vitro. The extent of alteration in the kinetics of cell proliferation indicated no significant differences between RF-radiation- and sham-exposed cells with respect to MTS assay and 8-OHdG. Under this experimental conditions tested, there is no evidence for the induction of genotoxic indices in human and mouse cells exposed in vitro for 7 days to 836.5 MHz or 1.765 GHz RF radiation at SARs of up to 35.6 or 38.2 W/kg

Sounding rocket study of auroral electron precipitation

International Nuclear Information System (INIS)

McFadden, J.P.

1985-01-01

Measurement of energetic electrons in the auroral zone have proved to be one of the most useful tools in investigating the phenomena of auroral arc formation. This dissertation presents a detailed analysis of the electron data from two sounding rocket campaigns and interprets the measurements in terms of existing auroral models. The Polar Cusp campaign consisted of a single rocket launched from Cape Parry, Canada into the afternoon auroral zone at 1:31:13 UT on January 21, 1982. The results include the measurement of a narrow, magnetic field aligned electron flux at the edge of an arc. This electron precipitation was found to have a remarkably constant 1.2 eV temperature perpendicular to the magnetic field over a 200 to 900 eV energy range. The payload also made simultaneous measurements of both energetic electrons and 3-MHz plasma waves in an auroral arc. Analysis has shown that the waves are propagating in the upper hybrid band and should be generated by a positive slope in the parallel electron distribution. A correlation was found between the 3-MHz waves and small positive slopes in the parallel electron distribution but experimental uncertainties in the electron measurement were large enough to influence the analysis. The BIDARCA campaign consisted of two sounding rockets launched from Poker Flat and Fort Yukon, Alaska at 9:09:00 UT and 9:10:40 UT on February 7, 1984

A 99%-efficiency GaN converter for 6.78 MHz magnetic resonant wireless power transfer system

Directory of Open Access Journals (Sweden)

Yoshiyuki Akuzawa

2014-10-01

Full Text Available The authors developed a high-efficiency gallium-nitride (GaN Class-E converter for a 6.78 MHz magnetic resonant wireless power transfer system. A negative-bias gate driver circuit made it possible to use a depletion mode GaN high-electron-mobility transistor (HEMT, and simplified the converter circuit. As the depletion mode GaN HEMT with very small gate–source capacitance provided almost ideal zero-voltage switching, the authors attained a drain efficiency of 98.8% and a total efficiency of 97.7%, including power consumption of a gate driver circuit, at a power output of 33 W. In addition, the authors demonstrated a 6.78 MHz magnetic resonant wireless power transfer system that consisted of the GaN Class-E converter, a pair of magnetic resonant coils 150 mm in diameter with an air-gap distance of 40 mm, and a full-bridge rectifier using Si Schottky barrier diodes. The system achieved a dc–dc efficiency of 82.8% at a power output of 25 W. The efficiencies of coil coupling and the rectifier were estimated to be ∼ 94 and 90%, respectively.

Central FPGA-based destination and load control in the LHCb MHz event readout

International Nuclear Information System (INIS)

Jacobsson, R.

2012-01-01

The readout strategy of the LHCb experiment is based on complete event readout at 1 MHz. A set of 320 sub-detector readout boards transmit event fragments at total rate of 24.6 MHz at a bandwidth usage of up to 70 GB/s over a commercial switching network based on Gigabit Ethernet to a distributed event building and high-level trigger processing farm with 1470 individual multi-core computer nodes. In the original specifications, the readout was based on a pure push protocol. This paper describes the proposal, implementation, and experience of a non-conventional mixture of a push and a pull protocol, akin to credit-based flow control. An FPGA-based central master module, partly operating at the LHC bunch clock frequency of 40.08 MHz and partly at a double clock speed, is in charge of the entire trigger and readout control from the front-end electronics up to the high-level trigger farm. One FPGA is dedicated to controlling the event fragment packing in the readout boards, the assignment of the farm node destination for each event, and controls the farm load based on an asynchronous pull mechanism from each farm node. This dynamic readout scheme relies on generic event requests and the concept of node credit allowing load control and trigger rate regulation as a function of the global farm load. It also allows the vital task of fast central monitoring and automatic recovery in-flight of failing nodes while maintaining dead-time and event loss at a minimum. This paper demonstrates the strength and suitability of implementing this real-time task for a very large distributed system in an FPGA where no random delays are introduced, and where extreme reliability and accurate event accounting are fundamental requirements. It was in use during the entire commissioning phase of LHCb and has been in faultless operation during the first two years of physics luminosity data taking.

Central FPGA-based destination and load control in the LHCb MHz event readout

Science.gov (United States)

Jacobsson, R.

2012-10-01

The readout strategy of the LHCb experiment is based on complete event readout at 1 MHz. A set of 320 sub-detector readout boards transmit event fragments at total rate of 24.6 MHz at a bandwidth usage of up to 70 GB/s over a commercial switching network based on Gigabit Ethernet to a distributed event building and high-level trigger processing farm with 1470 individual multi-core computer nodes. In the original specifications, the readout was based on a pure push protocol. This paper describes the proposal, implementation, and experience of a non-conventional mixture of a push and a pull protocol, akin to credit-based flow control. An FPGA-based central master module, partly operating at the LHC bunch clock frequency of 40.08 MHz and partly at a double clock speed, is in charge of the entire trigger and readout control from the front-end electronics up to the high-level trigger farm. One FPGA is dedicated to controlling the event fragment packing in the readout boards, the assignment of the farm node destination for each event, and controls the farm load based on an asynchronous pull mechanism from each farm node. This dynamic readout scheme relies on generic event requests and the concept of node credit allowing load control and trigger rate regulation as a function of the global farm load. It also allows the vital task of fast central monitoring and automatic recovery in-flight of failing nodes while maintaining dead-time and event loss at a minimum. This paper demonstrates the strength and suitability of implementing this real-time task for a very large distributed system in an FPGA where no random delays are introduced, and where extreme reliability and accurate event accounting are fundamental requirements. It was in use during the entire commissioning phase of LHCb and has been in faultless operation during the first two years of physics luminosity data taking.

Comparison of 250 MHz R10K Origin 2000 and 400 MHz Origin 2000 Using NAS Parallel Benchmarks

Science.gov (United States)

Turney, Raymond D.; Thigpen, William W. (Technical Monitor)

2001-01-01

This report describes results of benchmark tests on Steger, a 250 MHz Origin 2000 system with R10K processors, currently installed at the NASA Ames National Advanced Supercomputing (NAS) facility. For comparison purposes, the tests were also run on Lomax, a 400 MHz Origin 2000 with R12K processors. The BT, LU, and SP application benchmarks in the NAS Parallel Benchmark Suite and the kernel benchmark FT were chosen to measure system performance. Having been written to measure performance on Computational Fluid Dynamics applications, these benchmarks are assumed appropriate to represent the NAS workload. Since the NAS runs both message passing (MPI) and shared-memory, compiler directive type codes, both MPI and OpenMP versions of the benchmarks were used. The MPI versions used were the latest official release of the NAS Parallel Benchmarks, version 2.3. The OpenMP versions used were PBN3b2, a beta version that is in the process of being released. NPB 2.3 and PBN3b2 are technically different benchmarks, and NPB results are not directly comparable to PBN results.

Considering Point-of-Care Electronic Medical Resources in Lieu of Traditional Textbooks for Medical Education.

Science.gov (United States)

Hale, LaDonna S; Wallace, Michelle M; Adams, Courtney R; Kaufman, Michelle L; Snyder, Courtney L

2015-09-01

Selecting resources to support didactic courses is a critical decision, and the advantages and disadvantages must be carefully considered. During clinical rotations, students not only need to possess strong background knowledge but also are expected to be proficient with the same evidence-based POC resources used by clinicians. Students place high value on “real world” learning and therefore may place more value on POC resources that they know practicing clinicians use as compared with medical textbooks. The condensed nature of PA education requires students to develop background knowledge and information literacy skills over a short period. One way to build that knowledge and those skills simultaneously is to use POC resources in lieu of traditional medical textbooks during didactic training. Electronic POC resources offer several advantages over traditional textbooks and should be considered as viable options in PA education.

A 700 MHZ, 1 MW CW RF System for a FEL 100mA RF Photoinjector

CERN Document Server

Roybal, William; Reass, William; Rees, Daniel; Tallerico, Paul J; Torrez, Phillip A

2005-01-01

This paper describes a 700 MHz, 1 Megawatt CW, high efficiency klystron RF system utilized for a Free Electron Laser (FEL) high-brightness electron photoinjector (PI). The E2V klystron is mod-anode tube that operates with a beam voltage of 95 kV. This tube, operating with a 65% efficiency, requires ~96 watts of input power to produce in excess of 1 MW of output power. This output drives the 3rd cell of a 2½-cell, p-mode PI cavity through a pair of planar waveguide windows. Coupling is via a ridge-loaded tapered waveguide section and "dog-bone" iris. This paper will present the design of the RF, RF transport, coupling, and monitoring/protection systems that are required to support CW operations of the 100 mA cesiated, semi-porous SiC photoinjector.

Simulations of the ILC Electron Gun and Electron Bunching System

International Nuclear Information System (INIS)

Haakonsen, C.B.; McGill U.

2006-01-01

The International Linear Collider (ILC) is a proposed electron-positron collider, expected to provide insight into important questions in particle physics. A part of the global R and D effort for the ILC is the design of its electron gun and electron bunching system. The present design of the bunching system has two sub-harmonic bunchers, one operating at 108 MHz and one at 433MHz, and two 5-cell 1.3 GHz (L-band) bunchers. This bunching system has previously been simulated using the Phase and Radial Motion in Electron Linear Accelerators (PARMELA) software, and those simulations indicated that the design provides sufficient bunching and acceleration. Due to the complicated dynamics governing the electrons in the bunching system we decided to verify and expand the PARMELA results using the more recent and independent simulation software General Particle Tracer (GPT). GPT tracks the motion and interactions of a set of macro particles, each of which represent a number of electrons, and provides a variety of analysis capabilities. To provide initial conditions for the macro particles, a method was developed for deriving the initial conditions from detailed simulations of particle trajectories in the electron gun. These simulations were performed using the Egun software. For realistic simulation of the L-band bunching cavities, their electric and magnetic fields were calculated using the Superfish software and imported into GPT. The GPT simulations arrived at similar results to the PARMELA simulations for sub-harmonic bunching. However, using GPT it was impossible to achieve an efficient bunching performance of the first L-band bunching cavity. To correct this, the first L-band buncher cell was decoupled from the remaining 4 cells and driven as an independent cavity. Using this modification we attained results similar to the PARMELA simulations. Although the modified bunching system design performed as required, the modifications are technically challenging to implement

An Automated 476 MHz RF Cavity Processing Facility at SLAC

CERN Document Server

McIntosh, P; Schwarz, H

2003-01-01

The 476 MHz accelerating cavities currently used at SLAC are those installed on the PEP-II B-Factory collider accelerator. They are designed to operate at a maximum accelerating voltage of 1 MV and are routinely utilized on PEP-II at voltages up to 750 kV. During the summer of 2003, SPEAR3 will undergo a substantial upgrade, part of which will be to replace the existing 358.54 MHz RF system with essentially a PEP-II high energy ring (HER) RF station operating at 476.3 MHz and 3.2 MV (or 800 kV/cavity). Prior to installation, cavity RF processing is required to prepare them for use. A dedicated high power test facility is employed at SLAC to provide the capability of conditioning each cavity up to the required accelerating voltage. An automated LabVIEW based interface controls and monitors various cavity and test stand parameters, increasing the RF fields accordingly such that stable operation is finally achieved. This paper describes the high power RF cavity processing facility, highlighting the features of t...

Design of triode electron gun for electron LINAC

International Nuclear Information System (INIS)

Prasad, M.; Pande, S.A.; Hannurkar, P.R.

2003-01-01

A 10 MeV, 10 kW, electron linear accelerator is being developed at Centre for Advanced Technology, CAT for irradiation of agricultural products such as onions and potatoes. This facility required electron beam of variable energy and power. The linac structure consists of a thermionic triode gun, TW buncher and accelerator waveguide, focusing and centering coils, beam scanning system etc. The accelerator structure is disk loaded waveguide operating in TW 27π/3 mode at 2856 MHz. The triode gun is designed for operation at 50 kV. The gun is optimized for minimum grid voltage and minimum transverse beam dimensions. In this paper, the results of our optimization studies using computer code EGUN are presented. (author)

Induction of Autophagy in the Striatum and Hypothalamus of Mice after 835 MHz Radiofrequency Exposure.

Directory of Open Access Journals (Sweden)

Ju Hwan Kim

Full Text Available The extensive use of wireless mobile phones and associated communication devices has led to increasing public concern about potential biological health-related effects of the exposure to electromagnetic fields (EMFs. EMFs emitted by a mobile phone have been suggested to influence neuronal functions in the brain and affect behavior. However, the affects and phenotype of EMFs exposure are unclear. We applied radiofrequency (RF of 835 MHz at a specific absorption rate (SAR of 4.0 W/kg for 5 hours/day for 4 and 12 weeks to clarify the biological effects on mouse brain. Interestingly, microarray data indicated that a variety of autophagic related genes showed fold-change within small range after 835 MHz RF exposure. qRT-PCR revealed significant up-regulation of the autophagic genes Atg5, LC3A and LC3B in the striatum and hypothalamus after a 12-week RF. In parallel, protein expression of LC3B-II was also increased in both brain regions. Autophagosomes were observed in the striatum and hypothalamus of RF-exposed mice, based on neuronal transmission electron microscopy. Taken together, the results indicate that RF exposure of the brain can induce autophagy in neuronal tissues, providing insight into the protective mechanism or adaptation to RF stress.

Resource conservation approached with an appropriate collection and upgrade-remanufacturing for used electronic products.

Science.gov (United States)

Zlamparet, Gabriel I; Tan, Quanyin; Stevels, A B; Li, Jinhui

2018-03-01

This comparative research represents an example for a better conservation of resources by reducing the amount of waste (kg) and providing it more value under the umbrella of remanufacturing. The three discussed cases will expose three issues already addressed separately in the literature. The generation of waste electrical and electronic equipment (WEEE) interacts with the environmental depletion. In this article, we gave the examples of addressed issues under the concept of remanufacturing. Online collection opportunity eliminating classical collection, a business to business (B2B) implementation for remanufactured servers and medical devices. The material reuse (recycling), component sustainability, reuse (part harvesting), product reuse (after repair/remanufacturing) indicates the recovery potential using remanufacturing tool for a better conservation of resources adding more value to the products. Our findings can provide an overview of new system organization for the general collection, market potential and the technological advantages using remanufacturing instead of recycling of WEEE or used electrical and electronic equipment. Copyright © 2017. Published by Elsevier Ltd.

Assessment of cutaneous radiation fibrosis by 20 MHz-sonography

International Nuclear Information System (INIS)

Gottloeber, P.; Braun-Falco, B.; Plewig, G.; Kerscher, M.; Peter, R.U.; Nadeshina, N.

1996-01-01

Radiation fibrosis is the cardinal symptom of the chronicle stage of the cutaneous radiation syndrome. The degree of cutaneous fibrosis can clinically be estimated by palpation. High-frequency 20 MHz-sonography is an established, noninvasive procedure, which renders an exact determination of skin thickness and additionally densitometry is possible. We investigated 15 survivors of the Chernobyl accident in 1986, who developed symptoms of the chronic stage of the cutaneous radiation syndrome. We determined skin thickness and echogenicity of skin areas clinically suggestive of radiation fibrosis before, during and after treatment. 20 MHz-sonography showed a distinct enlargement of the echorich corium and a reduction of the subcutaneous fatty tissue in comparison with the unaffected, contralateral skin, here demonstrating typical features of radiation fibrosis, namely dermal fibrosis and reactive pseudoatrophy and fatty tissue. The histology presented an increase and swelling of the collagen fibers and atypical fibroblastic cells. The patients received treatment with low-dose interferon y (Polyfcron R , 3 x 50μg s.C., three times per week) up to 30 months. A marked reduction of skin thickness and echogenicity reaching nearly normal values could be observed. We conclude that 20 MHz-sonography is an easy to apply, noninvasive, well established procedure to quantify cutaneous radiation fibrosis and to assess therapeutic outcome

Effects of the Use of Electronic Human Resource Management (EHRM Within Human Resource Management (HRM Functions at Universities

Directory of Open Access Journals (Sweden)

Chux Gervase Iwu

2016-09-01

Full Text Available This study set out to examine the effect of e-hrm systems in assisting human resource practitioners to execute their duties and responsibilities. In comparison to developed economies of the world, information technology adoption in sub-Saharan Africa has not been without certain glitches. Some of the factors that are responsible for these include poor need identification, sustainable funding, and insufficient skills. Besides these factors, there is also the issue of change management and users sticking to what they already know. Although, the above factors seem negative, there is strong evidence that information systems such as electronic human resource management present benefits to an organization. To achieve this, a dual research approach was utilized. Literature assisted immensely in both the development of the conceptual framework upon which the study hinged as well as in the development of the questionnaire items. The study also made use of an interview checklist to guide the participants. The findings reveal a mix of responses that indicate that while there are gains in adopting e-hrm systems, it is wiser to consider supporting resources as well as articulate the needs of the university better before any investment is made.

Electronic human resource management: Enhancing or entrancing?

Directory of Open Access Journals (Sweden)

Paul Poisat

2017-07-01

Full Text Available Orientation: This article provides an investigation into the current level of development of the body of knowledge related to electronic human resource management (e-HRM by means of a qualitative content analysis. Several aspects of e-HRM, namely definitions of e-HRM, the theoretical perspectives around e-HRM, the role of e-HRM, the various types of e-HRM and the requirements for successful e-HRM, are examined. Research purpose: The purpose of the article was to determine the status of e-HRM and examine the studies that report on the link between e-HRM and organisational productivity. Motivation for the study: e-HRM has the capacity to improve organisational efficiency and leverage the role of human resources (HR as a strategic business partner. Main findings: The notion that the implementation of e-HRM will lead to improved organisational productivity is commonly assumed; however, empirical evidence in this regard was found to be limited. Practical/managerial implications: From the results of this investigation it is evident that more research is required to gain a greater understanding of the influence of e-HRM on organisational productivity, as well as to develop measures for assessing this influence. Contribution: This article proposes additional areas to research and measure when investigating the effectiveness of e-HRM. It provides a different lens from which to view e-HRM assessment whilst keeping it within recognised HR measurement parameters (the HR value chain. In addition, it not only provides areas for measuring e-HRM’s influence but also provides important clues as to how the measurements may be approached.

Search for a stochastic background of 100-MHz gravitational waves with laser interferometers.

Science.gov (United States)

Akutsu, Tomotada; Kawamura, Seiji; Nishizawa, Atsushi; Arai, Koji; Yamamoto, Kazuhiro; Tatsumi, Daisuke; Nagano, Shigeo; Nishida, Erina; Chiba, Takeshi; Takahashi, Ryuichi; Sugiyama, Naoshi; Fukushima, Mitsuhiro; Yamazaki, Toshitaka; Fujimoto, Masa-Katsu

2008-09-05

This Letter reports the results of a search for a stochastic background of gravitational waves (GW) at 100 MHz by laser interferometry. We have developed a GW detector, which is a pair of 75-cm baseline synchronous recycling (resonant recycling) interferometers. Each interferometer has a strain sensitivity of approximately 10;{-16} Hz;{-1/2} at 100 MHz. By cross-correlating the outputs of the two interferometers within 1000 seconds, we found h{100};{2}Omega_{gw}<6 x 10;{25} to be an upper limit on the energy density spectrum of the GW background in a 2-kHz bandwidth around 100 MHz, where a flat spectrum is assumed.

A Versatile High Speed 250 MHz Pulse Imager for Biomedical Applications

Science.gov (United States)

Epel, Boris; Sundramoorthy, Subramanian V.; Mailer, Colin; Halpern, Howard J.

2009-01-01

A versatile 250 MHz pulse electron paramagnetic resonance (EPR) instrument for imaging of small animals is presented. Flexible design of the imager hardware and software makes it possible to use virtually any pulse EPR imaging modality. A fast pulse generation and data acquisition system based on general purpose PCI boards performs measurements with minimal additional delays. Careful design of receiver protection circuitry allowed us to achieve very high sensitivity of the instrument. In this article we demonstrate the ability of the instrument to obtain three dimensional images using the electron spin echo (ESE) and single point imaging (SPI) methods. In a phantom that contains a 1 mM solution of narrow line (16 μT, peak-to-peak) paramagnetic spin probe we achieved an acquisition time of 32 seconds per image with a fast 3D ESE imaging protocol. Using an 18 minute 3D phase relaxation (T2e) ESE imaging protocol in a homogeneous sample a spatial resolution of 1.4 mm and a standard deviation of T2e of 8.5% were achieved. When applied to in vivo imaging this precision of T2e determination would be equivalent to 2 torr resolution of oxygen partial pressure in animal tissues. PMID:19924261

MIMOSA. A 32 channel 40 MHz Camac scaler

International Nuclear Information System (INIS)

Beer, A.; Bourgeois, F.; Critin, G.

1981-01-01

This report describes a 32 channel, 24 bit, 40 MHz single width Camac scaler based on the memory increment technique. The characteristics of the module are given and its logic is briefly described. Circuit diagrams and component lists are given. (orig.)

NICER Discovers mHz Oscillations and Marginally Stable Burning in GS 1826-24

Science.gov (United States)

Strohmayer, Tod E.; Gendreau, Keith C.; Keek, Laurens; Bult, Peter; Mahmoodifar, Simin; Chakrabarty, Deepto; Arzoumanian, Zaven; NICER Science Team

2018-01-01

To date, marginally stable thermonuclear burning, evidenced as mHz X-ray flux oscillations, has been observed in only five accreting neutron star binaries, 4U 1636-536, 4U 1608-52, Aql X-1, 4U 1323-619 and Terzan 5 X-2. Here we report the discovery with NASA's Neutron Star Interior Composition Explorer (NICER) of such oscillations from the well-known X-ray burster GS 1826-24. NICER observed GS 1826-24 on 9 September, 2017 for a total exposure of about 4 ksec. Timing analysis revealed highly significant oscillations at a frequency of 8.2 mHz in two successive pointings. The oscillations have a fractional modulation amplitude of approximately 3% for photon energies less than 6 keV. The observed frequency is consistent with the range observed in the other mHz QPO systems, and indeed is slightly higher than the frequency measured in 4U 1636-536 below which mHz oscillations ceased and unstable burning (X-ray bursts) resumed. We discuss the mass accretion rate dependence of the oscillations as well as the X-ray spectrum as a function of pulsation phase. We place the observations in the context of the current theory of marginally stable burning and briefly discuss the potential for constraining neutron star properties using mHz oscillations.

Identifying and evaluating electronic learning resources for use in adult-gerontology nurse practitioner education.

Science.gov (United States)

Thompson, Hilaire J; Belza, Basia; Baker, Margaret; Christianson, Phyllis; Doorenbos, Ardith; Nguyen, Huong

2014-01-01

Enhancing existing curricula to meet newly published adult-gerontology advanced practice registered nurse (APRN) competencies in an efficient manner presents a challenge to nurse educators. Incorporating shared, published electronic learning resources (ELRs) in existing or new courses may be appropriate in order to assist students in achieving competencies. The purposes of this project were to (a) identify relevant available ELR for use in enhancing geriatric APRN education and (b) to evaluate the educational utility of identified ELRs based on established criteria. A multilevel search strategy was used. Two independent team members reviewed identified ELR against established criteria to ensure utility. Only resources meeting all criteria were retained. Resources were found for each of the competency areas and included formats such as podcasts, Web casts, case studies, and teaching videos. In many cases, resources were identified using supplemental strategies and not through traditional search or search of existing geriatric repositories. Resources identified have been useful to advanced practice educators in improving lecture and seminar content in a particular topic area and providing students and preceptors with additional self-learning resources. Addressing sustainability within geriatric APRN education is critical for sharing of best practices among educators and for sustainability of teaching and related resources. © 2014.

Systematic review of electronic surveillance of infectious diseases with emphasis on antimicrobial resistance surveillance in resource-limited settings.

Science.gov (United States)

Rattanaumpawan, Pinyo; Boonyasiri, Adhiratha; Vong, Sirenda; Thamlikitkul, Visanu

2018-02-01

Electronic surveillance of infectious diseases involves rapidly collecting, collating, and analyzing vast amounts of data from interrelated multiple databases. Although many developed countries have invested in electronic surveillance for infectious diseases, the system still presents a challenge for resource-limited health care settings. We conducted a systematic review by performing a comprehensive literature search on MEDLINE (January 2000-December 2015) to identify studies relevant to electronic surveillance of infectious diseases. Study characteristics and results were extracted and systematically reviewed by 3 infectious disease physicians. A total of 110 studies were included. Most surveillance systems were developed and implemented in high-income countries; less than one-quarter were conducted in low-or middle-income countries. Information technologies can be used to facilitate the process of obtaining laboratory, clinical, and pharmacologic data for the surveillance of infectious diseases, including antimicrobial resistance (AMR) infections. These novel systems require greater resources; however, we found that using electronic surveillance systems could result in shorter times to detect targeted infectious diseases and improvement of data collection. This study highlights a lack of resources in areas where an effective, rapid surveillance system is most needed. The availability of information technology for the electronic surveillance of infectious diseases, including AMR infections, will facilitate the prevention and containment of such emerging infectious diseases. Copyright © 2018 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Design and Development of an Octopus Thermometric system for the 704 MHZ Single-Cell SPL Cavity at CERN

CERN Document Server

Liao, K; Brunner, O; Ciapala, E; Glenat, D; Weingarten, W

2012-01-01

The octopus thermometric system is designed for the 704 MHz superconducting proton linac (SPL) cavity to detect hot spots and X-rays caused by normal conducting defects and the impact of emission electrons. This system features an octopus body and tentacle structure for good contact with the cavity and easy assembly, a multiplexing circuit with integrated microprocessor for efficient readout and a high density temperature sensor arrangement in order to complete a high resolution temperature and X-ray map. The first prototype is being manufactured and investigations are undergoing for further development.

300-MHz-repetition-rate, all-fiber, femtosecond laser mode-locked by planar lightwave circuit-based saturable absorber.

Science.gov (United States)

Kim, Chur; Kim, Dohyun; Cheong, YeonJoon; Kwon, Dohyeon; Choi, Sun Young; Jeong, Hwanseong; Cha, Sang Jun; Lee, Jeong-Woo; Yeom, Dong-Il; Rotermund, Fabian; Kim, Jungwon

2015-10-05

We show the implementation of fiber-pigtailed, evanescent-field-interacting, single-walled carbon nanotube (CNT)-based saturable absorbers (SAs) using standard planar lightwave circuit (PLC) fabrication processes. The implemented PLC-CNT-SA device is employed to realize self-starting, high-repetition-rate, all-fiber ring oscillators at telecommunication wavelength. We demonstrate all-fiber Er ring lasers operating at 303-MHz (soliton regime) and 274-MHz (stretched-pulse regime) repetition-rates. The 303-MHz (274-MHz) laser centered at 1555 nm (1550 nm) provides 7.5 nm (19 nm) spectral bandwidth. After extra-cavity amplilfication, the amplified pulse train of the 303-MHz (274-MHz) laser delivers 209 fs (178 fs) pulses. To our knowledge, this corresponds to the highest repetition-rates achieved for femtosecond lasers employing evanescent-field-interacting SAs. The demonstrated SA fabrication method, which is based on well-established PLC processes, also shows a potential way for mass-producible and lower-cost waveguide-type SA devices suitable for all-fiber and waveguide lasers.

Design of 325 MHz spoke cavity

International Nuclear Information System (INIS)

Sha Peng; Huang Hong; Dai Jianping; Zu Guoquan; Li Han

2012-01-01

Spoke cavity can be used in the low-energy section of the proton accelerator. It has many significant advantages: compact structure, high value of R/Q, etc. The ADS (Accelerator Driven System) project will adopt many spoke cavities with different β values. Therefore, IHEP has began the research of β=0.14, 325 MHz spoke cavity. In this pa per, the dimensions, RF performances and mechanical properties of it are studied. (authors)

From Millennium ERM to Proquest 360 Resource Manager: Implementing a new Electronic Resources Management System ERMS in an International Graduate Research University in Saudi Arabia

KAUST Repository

Ramli, Rindra M.

2017-01-01

An overview of the Recommendation Study and the subsequent Implementation of a new Electronic Resources Management system ERMS in an international graduate research university in the Kingdom of Saudi Arabia. It covers the timeline, deliverables

Coupler Development and Gap Field Analysis for the 352 MHz Superconducting CH-Cavity

CERN Document Server

Liebermann, H; Ratzinger, U; Sauer, A C

2004-01-01

The cross-bar H-type (CH) cavity is a multi-gap drift tube structure based on the H-210 mode currently under development at IAP Frankfurt and in collaboration with GSI. Numerical simulations and rf model measurements showed that the CH-type cavity is an excellent candidate to realize s.c. multi-cell structures ranging from the RFQ exit energy up to the injection energy into elliptical multi-cell cavities. The reasonable frequency range is from about 150 MHz up to 800 MHz. A 19-cell, β=0.1, 352 MHz, bulk niobium prototype cavity is under development at the ACCEL-Company, Bergisch-Gladbach. This paper will present detailed MicroWave Studio simulations and measurements for the coupler development of the 352 MHz superconducting CH cavity. It will describe possibilities for coupling into the superconducting CH-Cavity. The development of the coupler is supported by measurement on a room temperature CH-copper model. We will present the first results of the measurements of different couplers, e.g. capacitiv...

Electron Spin Resonance Shift and Linewidth Broadening of Nitrogen-Vacancy Centers in Diamond as a Function of Electron Irradiation Dose

OpenAIRE

Kim, Edwin; Acosta, Victor M.; Bauch, Erik; Budker, Dmitry; Hemmer, Philip R.

2009-01-01

A high-nitrogen-concentration diamond sample was subject to 200-keV electron irradiation using a transmission electron microscope. The optical and spin-resonance properties of the nitrogen-vacancy (NV) color centers were investigated as a function of the irradiation dose up to 6.4\\times1021 e-/cm2. The microwave transition frequency of the NV- center was found to shift by up to 0.6% (17.1 MHz) and the linewidth broadened with increasing electron-irradiation dose. Unexpectedly, the measured ma...

A 2 MHz 3-port analog isolation and fanout module

International Nuclear Information System (INIS)

Beadle, E.R.

1995-01-01

In many accelerator based data acquisition systems, signal isolation is a necessary feature so ground loops are avoided. Here, a 3-port isolated circuit providing 1:3 fanout, buffering and amplification over a multi-megahertz bandwidth is presented. The circuit accepts a single input and drives 3 independently isolated output channels, up to ± 10 V into 50 ohms. The input and output isolation is supplied via a dual optocoupler, and the power isolation is achieved with DC/DC converters. In each channel, a voltage feedback amplifier is used in combination with the optocoupler to form a transimpedance configuration with the gain-bandwidth product (GBP) set by a pair of resistors. The feedback amplifier linearizes the optocoupler transfer characteristics using a servo technique and also controls the circuit drift, nonlinearity, and bandwidth. The circuit has demonstrated long-term drift of 4 MHz, and a SNR of >55 db in a 1 MHz bandwidth with < 1% THD for a 10 V amplitude sinusoidal input. With few modifications, this design is capable of providing input/output gain and bandwidth in the range of 10--50 MHz

Spiral Slotted Microstrip Antenna Design for 700 MHz Band Application

Directory of Open Access Journals (Sweden)

Ricardo Meneses González

2016-01-01

Full Text Available This work describes the design and implementation of spiral slotted microstrip antenna. Recently, just like other countries, in Mexico, terrestrial digital television has been implemented (analogic shutdown; as a consequence, the 700 MHz UFH Band (698–806 MHz has been opened to new telecommunications services, particularly wireless mobile communication. This technological advance represents a radio mobile antenna design challenge because it is necessary to design an antenna whose dimensions must be small enough, which satisfies gain, resonance frequency, and bandwidth requirements and is of low cost.

Open-Source Electronic Health Record Systems for Low-Resource Settings: Systematic Review.

Science.gov (United States)

Syzdykova, Assel; Malta, André; Zolfo, Maria; Diro, Ermias; Oliveira, José Luis

2017-11-13

Despite the great impact of information and communication technologies on clinical practice and on the quality of health services, this trend has been almost exclusive to developed countries, whereas countries with poor resources suffer from many economic and social issues that have hindered the real benefits of electronic health (eHealth) tools. As a component of eHealth systems, electronic health records (EHRs) play a fundamental role in patient management and effective medical care services. Thus, the adoption of EHRs in regions with a lack of infrastructure, untrained staff, and ill-equipped health care providers is an important task. However, the main barrier to adopting EHR software in low- and middle-income countries is the cost of its purchase and maintenance, which highlights the open-source approach as a good solution for these underserved areas. The aim of this study was to conduct a systematic review of open-source EHR systems based on the requirements and limitations of low-resource settings. First, we reviewed existing literature on the comparison of available open-source solutions. In close collaboration with the University of Gondar Hospital, Ethiopia, we identified common limitations in poor resource environments and also the main requirements that EHRs should support. Then, we extensively evaluated the current open-source EHR solutions, discussing their strengths and weaknesses, and their appropriateness to fulfill a predefined set of features relevant for low-resource settings. The evaluation methodology allowed assessment of several key aspects of available solutions that are as follows: (1) integrated applications, (2) configurable reports, (3) custom reports, (4) custom forms, (5) interoperability, (6) coding systems, (7) authentication methods, (8) patient portal, (9) access control model, (10) cryptographic features, (11) flexible data model, (12) offline support, (13) native client, (14) Web client,(15) other clients, (16) code

47 CFR 90.1408 - Organization and structure of the 700 MHz public/private partnership.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Organization and structure of the 700 MHz public/private partnership. 90.1408 Section 90.1408 Telecommunication FEDERAL COMMUNICATIONS COMMISSION... Partnership § 90.1408 Organization and structure of the 700 MHz public/private partnership. (a) The Upper 700...

47 CFR 27.1308 - Organization and structure of the 700 MHz public/private partnership.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Organization and structure of the 700 MHz public/private partnership. 27.1308 Section 27.1308 Telecommunication FEDERAL COMMUNICATIONS COMMISSION... Partnership § 27.1308 Organization and structure of the 700 MHz public/private partnership. (a) The Upper 700...

Analog Fiber Optic Link with DC-100 MHz Bandwidth

National Research Council Canada - National Science Library

Sullivan, C. A; Girardi, P. G; Lohrmann, Dieter R

2008-01-01

An analog fiber optic link covering the frequency range from DC to 100 MHz was designed, constructed, and tested, in order to connect a 10 kA pulse current probe to oscilloscopes for oscillographing...

VLA observations of NGC 1265 at 4886 MHz

International Nuclear Information System (INIS)

Owen, F.N.; Burns, J.O.; Rudnick, L.

1978-01-01

Observations are presented of the head-tail radio galaxy NGC 1265, made with the VLA at 4886 MHz. The total intensity brightness distribution has a resolution of 1' x 1'.5 and an rms noise of approx.150 μJy/beam area. These observations, combined with data at 2695 and 8085 MHz on a 35 km baseline in Green Bank, show that the nuclear component is less than 0'.1 and has a slightly inverted spectrum.The VLA map reveals a narrow continuous stream of emission leading away from the nucleus and out into the lower-surface brightness tail. Several small knots are superposed on the stream. This brightness distribution is compared with the independent-blob model of Jaffe and Perola. We find that the brightness distribution predicted by this model does not agree well with the observed brightness distribution. We suggest that a hot interstellar medium in the galaxy may be necessary to explain the complex structure

High performance flexible electronics for biomedical devices.

Science.gov (United States)

Salvatore, Giovanni A; Munzenrieder, Niko; Zysset, Christoph; Kinkeldei, Thomas; Petti, Luisa; Troster, Gerhard

2014-01-01

Plastic electronics is soft, deformable and lightweight and it is suitable for the realization of devices which can form an intimate interface with the body, be implanted or integrated into textile for wearable and biomedical applications. Here, we present flexible electronics based on amorphous oxide semiconductors (a-IGZO) whose performance can achieve MHz frequency even when bent around hair. We developed an assembly technique to integrate complex electronic functionalities into textile while preserving the softness of the garment. All this and further developments can open up new opportunities in health monitoring, biotechnology and telemedicine.

47 CFR 80.1061 - Special requirements for 406.0-406.1 MHz EPIRB stations.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Special requirements for 406.0-406.1 MHz EPIRB stations. 80.1061 Section 80.1061 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY... entitled RTCM Paper 77-02/SC110-STD, “RTCM Recommended Standards for 406 MHz Satellite Emergency Position...

Los Alamos free-electron laser (FEL) rf system

International Nuclear Information System (INIS)

Tallerico, P.J.; Lynch, M.T.

1985-01-01

The FEL rf system was designed for 3.6-MW rf pulses from two klystrons to drive two linacs and one deflection cavity at 1300 MHz. Two 108.33-MHz subharmonic buncher cavities and one fundamental buncher were also built, each powered by a 5-kW amplifier. A single phase-coherent source drives the various amplifiers as well as the grid of the electron gun, which is pulsed at 21.67 MHz. The initial buncher system did not work as well as expected, and the first linac tank required more rf power than anticipated. The light output was extremely sensitive to amplitude and phase errors. More powerful klystrons were developed and installed, and a method was discovered for operating a single subharmonic buncher and allowing the first linac to complete the bunching process. This paper shows the actual configuration used to operate the laser and discusses future improvements

Multi scale modeling of 2450MHz electric field effects on microtubule mechanical properties.

Science.gov (United States)

Setayandeh, S S; Lohrasebi, A

2016-11-01

Microtubule (MT) rigidity and response to 2450MHz electric fields were investigated, via multi scale modeling approach. For this purpose, six systems were designed and simulated to consider all types of feasible interactions between α and β monomers in MT, by using all atom molecular dynamics method. Subsequently, coarse grain modeling was used to design different lengths of MT. Investigation of effects of external 2450MHz electric field on MT showed MT less rigidity in the presence of such field, which may perturb its functions. Moreover, an additional computational setup was designed to study effects of 2450MHz field on MT response to AFM tip. It was found, more tip velocity led to MT faster transformation and less time was required to change MT elastic response to plastic one, applying constant radius. Moreover it was observed smaller tip caused to increase required time to change MT elastic response to plastic one, considering constant velocity. Furthermore, exposing MT to 2450MHz field led to no significant changes in MT response to AFM tip, but quick change in MT elastic response to plastic one. Copyright © 2016 Elsevier Inc. All rights reserved.

An automatic frequency control system of 2-MeV electronic LINAC

International Nuclear Information System (INIS)

Hu Xue; Zhang Junqiang; Zhong Shaopeng; Zhao Minghua

2013-01-01

Background: In electronic LINAC, the magnetron is often used as power source. The output frequency of magnetron always changes with the environment and the frequency difference between the output of magnetron and the frequency of accelerator, which will result in the bad performance of LINAC systems. Purpose: To ensure the performance of the work of entire LINAC system effectively, an automatic frequency control system is necessary. Methods: A phase locked frequency discriminator is designed to discriminate the frequency of accelerator guide and magnetron, and analogue circuit is used to process the output signals of frequency discriminator unit. Results: Working with the automatic frequency control (AFC) system, the output frequency of magnetron can be controlled in the range of (2998 MHz, 2998 MHz + 70 kHz) and (2998 MHz, 2998 MHz - 30 kHz). Conclusions: Under the measurement and debug, the functionality of frequency discriminator unit and signal processor circuit is tested effectively. (authors)

The front-end (Level-0) electronics interface module for the LHCb RICH detectors

Energy Technology Data Exchange (ETDEWEB)

Adinolfi, M. [Sub-department of Particle Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford, OX1 3RH (United Kingdom); Bibby, J.H. [Sub-department of Particle Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford, OX1 3RH (United Kingdom); Brisbane, S. [Sub-department of Particle Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford, OX1 3RH (United Kingdom); Gibson, V. [Cavendish Laboratory, University of Cambridge, Madingley Road, Cambridge CB3 0HE (United Kingdom); Harnew, N. [Sub-department of Particle Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford, OX1 3RH (United Kingdom); Jones, M. [Sub-department of Particle Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford, OX1 3RH (United Kingdom); Libby, J. [Sub-department of Particle Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford, OX1 3RH (United Kingdom)]. E-mail: j.libby1@physics.ox.ac.uk; Powell, A. [Sub-department of Particle Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford, OX1 3RH (United Kingdom); Newby, C. [Sub-department of Particle Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford, OX1 3RH (United Kingdom); Rotolo, N. [Sub-department of Particle Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford, OX1 3RH (United Kingdom); Smale, N. [Sub-department of Particle Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford, OX1 3RH (United Kingdom); Somerville, L.; Sullivan, P.; Topp-Jorgensen, S. [Sub-department of Particle Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford, OX1 3RH (United Kingdom); Wotton, S. [Cavendish Laboratory, University of Cambridge, Madingley Road, Cambridge CB3 0HE (United Kingdom); Wyllie, K. [CERN, CH-1211, Geneva 23 (Switzerland)

2007-03-11

The front-end (Level-0) electronics interface module for the LHCb Ring Imaging Cherenkov (RICH) detectors is described. This module integrates the novel hybrid photon detectors (HPDs), which instrument the RICH detectors, to the LHCb trigger, data acquisition (DAQ) and control systems. The system operates at 40 MHz with a first-level trigger rate of 1 MHz. The module design is presented and results are given for both laboratory and beam tests.

The front-end (Level-0) electronics interface module for the LHCb RICH detectors

International Nuclear Information System (INIS)

Adinolfi, M.; Bibby, J.H.; Brisbane, S.; Gibson, V.; Harnew, N.; Jones, M.; Libby, J.; Powell, A.; Newby, C.; Rotolo, N.; Smale, N.; Somerville, L.; Sullivan, P.; Topp-Jorgensen, S.; Wotton, S.; Wyllie, K.

2007-01-01

The front-end (Level-0) electronics interface module for the LHCb Ring Imaging Cherenkov (RICH) detectors is described. This module integrates the novel hybrid photon detectors (HPDs), which instrument the RICH detectors, to the LHCb trigger, data acquisition (DAQ) and control systems. The system operates at 40 MHz with a first-level trigger rate of 1 MHz. The module design is presented and results are given for both laboratory and beam tests

Evaluation of three electronic report processing systems for preparing hydrologic reports of the U.S Geological Survey, Water Resources Division

Science.gov (United States)

Stiltner, G.J.

1990-01-01

In 1987, the Water Resources Division of the U.S. Geological Survey undertook three pilot projects to evaluate electronic report processing systems as a means to improve the quality and timeliness of reports pertaining to water resources investigations. The three projects selected for study included the use of the following configuration of software and hardware: Ventura Publisher software on an IBM model AT personal computer, PageMaker software on a Macintosh computer, and FrameMaker software on a Sun Microsystems workstation. The following assessment criteria were to be addressed in the pilot studies: The combined use of text, tables, and graphics; analysis of time; ease of learning; compatibility with the existing minicomputer system; and technical limitations. It was considered essential that the camera-ready copy produced be in a format suitable for publication. Visual improvement alone was not a consideration. This report consolidates and summarizes the findings of the electronic report processing pilot projects. Text and table files originating on the existing minicomputer system were successfully transformed to the electronic report processing systems in American Standard Code for Information Interchange (ASCII) format. Graphics prepared using a proprietary graphics software package were transferred to all the electronic report processing software through the use of Computer Graphic Metafiles. Graphics from other sources were entered into the systems by scanning paper images. Comparative analysis of time needed to process text and tables by the electronic report processing systems and by conventional methods indicated that, although more time is invested in creating the original page composition for an electronically processed report , substantial time is saved in producing subsequent reports because the format can be stored and re-used by electronic means as a template. Because of the more compact page layouts, costs of printing the reports were 15% to 25

Development of BPM Electronics at the JLAB FEL

Science.gov (United States)

Sexton, D.; Evtushenko, P.; Jordan, K.; Yan, J.; Dutton, S.; Moore, W.; Evans, R.; Coleman, J.

2006-11-01

A new version of BPM electronics based on the AD8362 RMS detector, which is a direct RF to DC converter, is under development at the JLAB FEL. Each of these new BPM electronics utilizes an embedded ColdFire Microprocessor for data processing and communication with the EPICS control system via TCP/IP. The ColdFire runs RTEMS, which is an open source real-time operating system. The JLAB FEL is a SRF Energy Recovery LINAC capable of running up to 10 mA CW beam with a 74.85 MHz micropulse frequency. For diagnostic reasons and for machine tune up, the micropulse frequency can be reduced to 1.17 MHz, which corresponds to about 160 μA of beam current. It is required that the BPM system would be functional for all micropulse frequencies. By taking into account the headroom for the beam steering and current variations the dynamic range of the RF front end is required to be about 60 dB. A BPM resolution of at least 100 μm is required, whereas better resolution is very desirable to make it possible for more accurate measurements of the electron beam optics. Some results of the RF front end development are presented as well as the first measurements made with an electron beam.

Influence of 1800 MHz GSM-like electromagnetic radiation exposure on fracture healing.

Science.gov (United States)

Aslan, Ahmet; Kırdemır, Vecihi; Kocak, Ahmet; Atay, Tolga; Baydar, Metin Lütfi; Özerdemoglu, Remzi Arif; Aydogan, Nevres Hürriyet

2014-02-01

In this study, we aimed to investigate whether 1800 MHz frequency electromagnetic radiation (EMR) has an effect on bone healing. A total of 30 Wistar albino rats were divided into two equal groups. Fractures were created in the right tibias of all rats; next, intramedullary fixations with K-wire were performed. A control group (Group I) was kept under the same experimental conditions except without EMR exposure. Rats in Group II were exposed to an 1800 MHz frequency EMR for 30 min a day for 5 days a week. Next, radiological, mechanical, and histological examinations were performed to evaluate tibial fracture healing. Radiological, histological and mechanical scores were not significantly different between groups (respectively, p = 0.114, p = 0.184 and p = 0.083), and all of these scores were lower than those of the controls. EMR at 1800 MHz frequency emitted from cellular phones has no effect on bone fracture healing. Copyright © 2014 IMSS. Published by Elsevier Inc. All rights reserved.

Nouvelle application de control des cavités 200 MHz RF du PS (CERN)

CERN Document Server

Cotte, D

2011-01-01

Le système Radio Fréquence (RF) 200MHz du PS est un outil essentiel pour la préparation des faisceaux haute intensité du PS. Dans l’anneau PS on trouve 6 cavités 200 MHz utilisées pour contrôler : • l’émittance longitudinale des « bunches » • le processus de « Rebunching » du faisceau avant de l’envoyer au SPS. Chaque cavité est pilotée par des événements appelés « timing » et suit une fonction de tension programmée. Cependant, l’électronique utilisée pour piloter les cavités 200 MHz du PS est obsolète et sa fiabilité non garantie pour cause du manque de pièces de rechange. Ce document décrit le fonctionnement du nouveau programme d’application qui fait abstraction de l’ancienne matrice hardware. Elle suit les recommandations décrites dans l’étude d’une nouvelle structure pour le système RF 200MHz du PS. [1

Use and User Perception of Electronic Information Resources: A Case Study of Siva Institute of Frontier Technology, India

Directory of Open Access Journals (Sweden)

Velmurugan Chandran

2013-12-01

Full Text Available The present study aims to explore the use and user perception of electronic resources in Siva Institute of Frontier Technology, India. A total number of 123 users were taken into account for the study through a questionnaire-based survey method. A well-structured questionnaire was designed and distributed to the selected 200 students and staff members. 123 copies of the questionnaires were returned dully filled in and the overall response rate was 61.50 percent. The questionnaire contained both open- and close-ended questions. The collected data were classified, analyzed, and tabulated by using simple statistical methods. This study covers the impact of electronic resources on students and faculty in their academic pursuit.

A preliminary categorization of end-of-life electrical and electronic equipment as secondary metal resources

International Nuclear Information System (INIS)

Oguchi, Masahiro; Murakami, Shinsuke; Sakanakura, Hirofumi; Kida, Akiko; Kameya, Takashi

2011-01-01

Highlights: → End-of-life electrical and electronic equipment (EEE) as secondary metal resources. → The content and the total amount of metals in specific equipment are both important. → We categorized 21 EEE types from contents and total amounts of various metals. → Important equipment types as secondary resources were listed for each metal kind. → Collectability and possible collection systems of various EEE types were discussed. - Abstract: End-of-life electrical and electronic equipment (EEE) has recently received attention as a secondary source of metals. This study examined characteristics of end-of-life EEE as secondary metal resources to consider efficient collection and metal recovery systems according to the specific metals and types of EEE. We constructed an analogy between natural resource development and metal recovery from end-of-life EEE and found that metal content and total annual amount of metal contained in each type of end-of-life EEE should be considered in secondary resource development, as well as the collectability of the end-of-life products. We then categorized 21 EEE types into five groups and discussed their potential as secondary metal resources. Refrigerators, washing machines, air conditioners, and CRT TVs were evaluated as the most important sources of common metals, and personal computers, mobile phones, and video games were evaluated as the most important sources of precious metals. Several types of small digital equipment were also identified as important sources of precious metals; however, mid-size information and communication technology (ICT) equipment (e.g., printers and fax machines) and audio/video equipment were shown to be more important as a source of a variety of less common metals. The physical collectability of each type of EEE was roughly characterized by unit size and number of end-of-life products generated annually. Current collection systems in Japan were examined and potentially appropriate collection

Performance analysis of commercial MOSFET packages in Class E converter operating at 2.56 MHz

DEFF Research Database (Denmark)

Nair, Unnikrishnan Raveendran; Munk-Nielsen, Stig; Jørgensen, Asger Bjørn

2017-01-01

resistance and high temperature operation over Si devices have aided in the paradigm shift towards wide bandgap devices. The low gate charge requirements of SiC MOSFETs enables use of these devices in radio frequency (RF) converters using resonant topologies operating at MHz frequency range. The RF...... are not commercially available and power modules have to be custom designed for these applications. This work demonstrates performance of various commercial MOSFET packages at frequency of 2.56 MHz. Commercial SiC MOSFETs in TO-247 and D2Pak packs are tested in Class E resonant converter operating at 2.56 MHz...

CAMEX-4 MIPS 915 MHZ DOPPLER WIND PROFILER V1

Data.gov (United States)

National Aeronautics and Space Administration — The University of Alabama in Huntsville (UAH) Mobile Integrated Profiling System (MIPS) is a mobile atmospheric profiling system. It includes a 915 MHz Doppler...

Principles of formation of the content of an educational electronic resource on the basis of general and didactic patterns of learning

Directory of Open Access Journals (Sweden)

Ольга Юрьевна Заславская

2018-12-01

Full Text Available The article considers the influence of the development of technical means of teaching on the effectiveness of educational and methodical resources. Modern opportunities of information and communication technologies allow creating electronic educational resources that represent educational information that automates the learning process, provide information assistance, if necessary, collect and process statistical information on the degree of development of the content of the school material by schoolchildren, set an individual trajectory of learning, and so on. The main principle of data organization is the division of the training course into separate sections on the thematic elements and components of the learning process. General regularities include laws that encompass the entire didactic system, and in specific (particular cases, those whose actions extend to a separate component (aspect of the system. From the standpoint of the existence of three types of electronic training modules in the aggregate content of the electronic learning resource - information, control and module of practical classes - the principles of the formation of the electronic learning resource, in our opinion, should regulate all these components. Each of the certain principles is considered in the groups: scientific orientation, methodological orientation, systemic nature, accounting of interdisciplinary connections, fundamentalization, systematic and dosage sequence, rational use of study time, accessibility, minimization, operationalization of goals, unified identification diagnosis.

The Phase Servo Tuner Control system of the ALS 500 MHz cavity

International Nuclear Information System (INIS)

Lo, C.C.; Taylor, B.

1993-05-01

Three 500 MHz cavities are used in the Booster and Storage Ring of the Advanced Light Source (ALS). Due to different varying parameters, a control system is required to keep the cavities in tune during operation. The tuning of the 500 MHz cavity is achieved by detecting the phase error between the drive signal and the cavity probe signal. The error signal is amplified and used to drive a stepping motor which in turn moves a metallic cylinder in or out of the cavity to achieve tuning

Status of 174 MHz RF system for BEP

International Nuclear Information System (INIS)

Biryuchevsky, Yu.A.; Gorniker, E.I.; Kendjebulatov, E.K.; Krutikhin, S.A.; Kurkin, G.Ya.; Petrov, V.M.; Pilan, A.M.

2012-01-01

The new RF system for the BEP storage ring (which is an injector of VEPP-2000 accelerating complex) will increase the particles energy in the BEP from 0.9 to 1 GeV. RF system operates at a frequency of 174 MHz and consists of an accelerating cavity, RF power generator and control system.

Nonambipolar electron source

International Nuclear Information System (INIS)

Longmier, B.; Baalrud, S.; Hershkowitz, N.

2006-01-01

A radio frequency (rf) plasma-based electron source that does not rely on electron emission at a cathode surface has been constructed. All of the random electron flux incident on an exit aperture is extracted through an electron sheath resulting in total nonambipolar flow within the device when the ratio of the ion loss area to the electron loss area is approximately equal to the square root of the ratio of the ion mass to the electron mass, and the ion sheath potential drop at the chamber walls is much larger than T e /e. The nonambipolar electron source (NES) has an axisymmetric magnetic field of 100 G at the extraction aperture that results in a uniform plasma potential across the aperture, allowing the extraction of all the incident electron flux without the use of grids. A prototype NES has produced 15 A of continuous electron current, using 15 SCCM (SCCM denotes cubic centimeter per minute at STP) Ar, 1200 W rf power at 13.56 MHz, and 6 times gas utilization. Alternatively 8 A of electron current can be produced, using 3 SCCM Ar at 1200 W rf and 20 times gas utilization. NES could replace hollow cathode electron sources in a wide variety of applications

CAMEX-4 MIPS 915 MHZ DOPPLER WIND PROFILER V1

Data.gov (United States)

National Aeronautics and Space Administration — The CAMEX-4 MIPS 915 MHZ Doppler Wind Profiler dataset was collected by the University of Alabama in Huntsville (UAH) Mobile Integrated Profiling System (MIPS),...

A reflexing electron microwave amplifier for rf particle accelerator applications

International Nuclear Information System (INIS)

Fazio, M.V.; Hoeberling, R.F.

1988-01-01

The evolution of rf-accelerator technology toward high-power, high-current, low-emittance beams produces an ever-increasing demand for efficient, very high power microwave power sources. The present klystron technology has performed very well but is not expected to produce reliable gigawatt peak-power units in the 1- to 10-GHz regime. Further major advancements must involve other types of sources. The reflexing-electron class of sources can produce microwave powers at the gigawatt level and has demonstrated operation from 800-MHz to 40-GHz. The pulse length appears to be limited by diode closure, and reflexing-electron devices have been operated in a repetitively pulsed mode. A design is presented for a reflexing electron microwave amplifier that is frequency and phase locked. In this design, the generated microwave power can be efficiently coupled to one or several accelerator loads. Frequency and phase-locking capability may permit parallel-source operation for higher power. The low-frequency (500-MHz to 10-GHz) operation at very high power required by present and proposed microwave particle accelerators makes an amplifier, based on reflexing electron phenomena, a candidate for the development of new accelerator power sources. (author)

Multipacting and higher order mode analysis of 325 MHz single spoke resonators

International Nuclear Information System (INIS)

Pal, Mukesh Kumar; Gaur, Rahul; Kumar, Vinit

2015-01-01

Superconducting Single Spoke Resonators (SSRs) will be used to accelerate the H - ions from 3 MeV to 160 MeV in the injector linac for the proposed Indian Spallation Neutron Source (ISNS) at RRCAT. Electromagnetic design studies of 325 MHz SSRs have been performed for βg = 0.11, 0.22 and 0.42. Performance of SSRs are typically limited by multipacting phenomenon and higher order modes. In our design, we have performed detailed studies of electron multipacting phenomenon, which is a resonant process, using a computer code CST-PS. Based on this analysis, refinements in the geometry of the SSRs have been made, in order to reduce the growth rate of multipacting. We have also carried out extensive analysis of Higher Order Mode (HOM) for the SSR structure, using the computer code CST-MWS, where the R/Q parameter has been calculated for monopole, dipole and quadrupole HaMs. Details of these calculations will be presented in this paper. (author)

From Millennium ERM to Proquest 360 Resource Manager: Implementing a new Electronic Resources Management System ERMS in an International Graduate Research University in Saudi Arabia

KAUST Repository

Ramli, Rindra M.

2017-05-17

An overview of the Recommendation Study and the subsequent Implementation of a new Electronic Resources Management system ERMS in an international graduate research university in the Kingdom of Saudi Arabia. It covers the timeline, deliverables and challenges as well as lessons learnt by the Project Team.

Technology development of solid state rf systems at 350 MHz and 325 MHz for RF accelerator

International Nuclear Information System (INIS)

Rama Rao, B.V.; Mishra, J.K.; Pande, Manjiri; Gupta, S.K.

2011-01-01

For decades vacuum tubes and klystrons have been used in high power application such as RF accelerators and broadcast transmitters. However, now, the solid-state technology can give power output in kilowatt regime. Higher RF power output can be achieved by combining several solid-state power amplifier modules using power combiners. This technology presents several advantages over traditional RF amplifiers, such as simpler start-up procedure, high modularity, high redundancy and flexibility, elimination of high voltage supplies and high power circulators, low operational cost, online maintenance without shut down of RF power station and no warm up time. In BARC, solid state amplifier technology development is being done both at 350 MHz and 325 MHz using RF transistors such as 1 kW LDMOS and 350 Watt VDMOS. Topology of input and output matching network in RF modules developed, consist of two L type matching sections with each section having a combination of series micro-strip line and parallel capacitor. The design is of equal Q for both the sections and of 25 ohm characteristics impedance of micro strip lines. Based on this, lengths of micro strips lines and values of shunt capacitors have been calculated. The calculated and simulated values of network elements have been compared. Similarly power combiners have been designed and developed based on Wilkinson techniques without internal resistors and using coaxial technology. This paper presents design and development of RF power amplifier modules, associated power combiner technologies and then integrated RF power amplifier. (author)

Investigation of using shrinking method in construction of Institute for Research in Fundamental Sciences Electron Linear Accelerator TW-tube (IPM TW-Linac tube)

Science.gov (United States)

Ghasemi, F.; Abbasi Davani, F.

2015-06-01

Due to Iran's growing need for accelerators in various applications, IPM's electron Linac project has been defined. This accelerator is a 15 MeV energy S-band traveling-wave accelerator which is being designed and constructed based on the klystron that has been built in Iran. Based on the design, operating mode is π /2 and the accelerating chamber consists of two 60cm long tubes with constant impedance and a 30cm long buncher. Amongst all construction methods, shrinking method is selected for construction of IPM's electron Linac tube because it has a simple procedure and there is no need for large vacuum or hydrogen furnaces. In this paper, different aspects of this method are investigated. According to the calculations, linear ratio of frequency alteration to radius change is 787.8 MHz/cm, and the maximum deformation at the tube wall where disks and the tube make contact is 2.7μ m. Applying shrinking method for construction of 8- and 24-cavity tubes results in satisfactory frequency and quality factor. Average deviations of cavities frequency of 8- and 24-cavity tubes to the design values are 0.68 MHz and 1.8 MHz respectively before tune and 0.2 MHz and 0.4 MHz after tune. Accelerating tubes, buncher, and high power couplers of IPM's electron linac are constructed using shrinking method.

Investigations in a drift chamber using 250 MHz analogue-digital-converters

International Nuclear Information System (INIS)

Scharf, F.A.

1993-06-01

The performance of a new 250 MHz FADC module was investigated in a small drift chamber system. Straight tracks were induced in the chamber volume by UV-LASER beams. The time resolution was determined from drift time measurements for four neighbouring signal wires. By use of a beam splitter a pair of parallel beams was produced. An appropriate rotation of this pair relative to the signal wire plane allowed the determination of the double hit resolution. A comparison of the obtained values with the results achieved with 100 MHz FADC modules showed that the new module is well suited for chamber read out. The attainable improvements however are small. (orig.) [de

Development of HF-systems for electron storage systems

International Nuclear Information System (INIS)

Androsov, V.P.; Karnaukhov, I.M.; Popkov, Yu.P.; Reva, S.N.; Telegin, Yu.N.

1999-01-01

Development of HF systems for electron storages is described. Its final task is construction of 100 kW HF station at 699,3 MHz frequency consisting from low-power HF system, klystron amplifier, wave line for HF power transmission and accelerating section. Functional parameters of HF station are given

The Synthesis of the Hierarchical Structure of Information Resources for Management of Electronic Commerce Entities

Directory of Open Access Journals (Sweden)

Krutova Anzhelika S.

2017-06-01

Full Text Available The aim of the article is to develop the theoretical bases for the classification and coding of economic information and the scientific justification of the content of information resources of an electronic commerce enterprise. The essence of information resources for management of electronic business entities is investigated. It is proved that the organization of accounting in e-commerce systems is advisable to be built on the basis of two circuits: accounting for financial flows and accounting associated with transformation of business factors in products and services as a result of production activities. There presented a sequence of accounting organization that allows to combine the both circuits in a single information system, which provides a possibility for the integrated replenishment and distributed simultaneous use of the e-commerce system by all groups of users. It is proved that the guarantee of efficient activity of the information management system of electronic commerce entities is a proper systematization of the aggregate of information resources on economic facts and operations of an enterprise in accordance with the management tasks by building the hierarchy of accounting nomenclatures. It is suggested to understand nomenclature as an objective, primary information aggregate concerning a certain fact of the economic activity of an enterprise, which is characterized by minimum requisites, is entered into the database of the information system and is to be reflected in the accounting system. It is proposed to build a database of e-commerce systems as a part of directories (constants, personnel, goods / products, suppliers, buyers and the hierarchy of accounting nomenclatures. The package of documents regulating the organization of accounting at an enterprise should include: the provision on the accounting services, the order on the accounting policy, the job descriptions, the schedules of information exchange, the report card and

Design of 118 MHz twelfth harmonic cavity of APS PAR

International Nuclear Information System (INIS)

Kang, Y.W.; Kustom, R.L.; Bridges, J.F.

1992-01-01

Two radio frequency (RF) cavities are needed in the Positron Accumulator Ring (PAR) of the Advanced Photon Source. One is for the first harmonic frequency at 9.8 MHz, and the other is for the twelfth harmonic frequency at 118 MHz. This note reports on the design of the 118 MHz RF cavity. Computer models are used to find the mode frequencies, impedances, Q-factors, and field distributions in the cavity. The computer codes MAFIA, URMEL, and URMEL-T are useful tools which model and simulate the resonance characteristics of a cavity. These codes employ the finite difference method to solve Maxwell's equations. MAFIA is a three-dimensional problem solver and uses square patches to approximate the inner surface of a cavity. URMEL and URMEL-T are two-dimensional problem solvers and use rectangular and triangular meshes, respectively. URMEL-T and MAFIA can handle problems with arbitrary dielectric materials located inside the boundary. The cavity employs a circularly cylindrical ceramic window to limit the vacuum to the beam pipe. The ceramic window used in the modeling will have a wall thickness of 0.9 cm. This wall thickness is not negligible in determining the resonant frequencies of the cavity. In the following, results of two- and three-dimensional modeling of the cavities using the URMEL-T and MAFIA codes are reported

Velocities of Auroral Coherent Echoes At 12 and 144 Mhz

Science.gov (United States)

Koustov, A. V.; Danskin, D. W.; Makarevitch, R. A.; Uspensky, M. V.; Janhunen, P.; Nishitani, N.; Nozawa, N.; Lester, M.; Milan, S.

Two Doppler coherent radar systems are currently working at Hankasalmi, Finland, the STARE and CUTLASS radars operating at 144 MHz and 12 MHz, respectively. The STARE beam 3 is nearly co-located with the CUTLASS beam 5 providing an opportunity for echo velocity comparison along the same direction but at significantly different radar frequencies. In this study we consider one event when STARE radar echoes are detected t the same ranges as CUTLASS radar echoes. The observations are complemented by EISCAT measurements of the ionospheric electric field and elec- tron density behavior at one range of 900 km. Two separate situations are studied; for the first one, CUTLASS observed F-region echoes (including the range of the EIS- CAT measurements) while for the second one CUTLASS observed E-region echoes. In both cases STARE E-region measurements were available. We show that F-region CUTLASS velocities agree well with the convection component along the CUTLASS radar beam while STARE velocities are sometimes smaller by a factor of 2-3. For the second case, STARE velocities are found to be either smaller or larger than CUTLASS velocities, depending on range. Plasma physics of E- and F-region irregularities is dis- cussed in attempt to explain inferred relationship between various velocities. Special attention is paid to ionospheric refraction that is important for the detection of 12-MHz echoes.

Spectroscopic study of atmospheric pressure 915 MHz microwave plasma at high argon flow rate

International Nuclear Information System (INIS)

Miotk, R; Hrycak, B; Jasinski, M; Mizeraczyk, J

2012-01-01

In this paper results of optical emission spectroscopic (OES) study of atmospheric pressure microwave 915 MHz argon plasma are presented. The plasma was generated in microwave plasma source (MPS) cavity-resonant type. The aim of research was determination of electron excitation temperature T exc gas temperature Tg and electron number density n e . All experimental tests were performed with a gas flow rate of 100 and 200 l/min and absorbed microwave power PA from 0.25 to 0.9 kW. The emission spectra at the range of 300 – 600 nm were recorded. Boltzmann plot method for argon 5p – 4s and 5d – 4p transition lines allowed to determine T exc at level of 7000 K. Gas temperature was determined by comparing the measured and simulated spectra using LIFBASE program and by analyzing intensities of two groups of unresolved rotational lines of the OH band. Gas temperature ranged 600 – 800 K. The electron number density was determined using the method based on the Stark broadening of hydrogen H β line. The measured n e rang ed 2 × 10 15 − 3.5×10 15 cm −3 , depending on the absorbed microwave power. The described MPS works very stable with various working gases at high flow rates, that makes it an attractive tool for different gas processing.

Prototype 350 MHz niobium spoke-loaded cavities

International Nuclear Information System (INIS)

Delayen, J. R.; Kedzie, M.; Mammosser, J.; Piller, C.; Shepard, K. W.

1999-01-01

This paper reports the development of 350 MHz superconducting cavities of a spoke-loaded geometry, intended for the velocity range 0.2 < v/c < 0.6. Two prototype single-cell cavities have been designed, one optimized for velocity v/c = 0.4, and the other for v/c = 0.29. Construction of the prototype niobium cavities is nearly complete. Details of the design and construction are discussed, along with the results of cold tests

Prototype 350 MHz niobium spoke-loaded cavities.

Energy Technology Data Exchange (ETDEWEB)

Delayen, J. R.; Kedzie, M.; Mammosser, J.; Piller, C.; Shepard, K. W.

1999-05-10

This paper reports the development of 350 MHz superconducting cavities of a spoke-loaded geometry, intended for the velocity range 0.2 < v/c < 0.6. Two prototype single-cell cavities have been designed, one optimized for velocity v/c = 0.4, and the other for v/c = 0.29. Construction of the prototype niobium cavities is nearly complete. Details of the design and construction are discussed, along with the results of cold tests.

76 FR 51271 - Implementing a Nationwide, Broadband, Interoperable Public Safety Network in the 700 MHz Band

Science.gov (United States)

2011-08-18

... 700 MHz Band AGENCY: Federal Communications Commission. ACTION: Final rule. SUMMARY: In this document... medical services, Incorporation by reference, Individuals with disabilities, Radio, Reporting and...- 798 MHz bands. * * * * * Service Availability. The use of a public safety broadband network on a day...

Controlling user access to electronic resources without password

Science.gov (United States)

Smith, Fred Hewitt

2015-06-16

Described herein are devices and techniques for remotely controlling user access to a restricted computer resource. The process includes pre-determining an association of the restricted computer resource and computer-resource-proximal environmental information. Indicia of user-proximal environmental information are received from a user requesting access to the restricted computer resource. Received indicia of user-proximal environmental information are compared to associated computer-resource-proximal environmental information. User access to the restricted computer resource is selectively granted responsive to a favorable comparison in which the user-proximal environmental information is sufficiently similar to the computer-resource proximal environmental information. In at least some embodiments, the process further includes comparing user-supplied biometric measure and comparing it with a predetermined association of at least one biometric measure of an authorized user. Access to the restricted computer resource is granted in response to a favorable comparison.

500 MHz transient digitizers based on GaAs CCDs

International Nuclear Information System (INIS)

Bryman, D.; Cresswell, J.V.; LeNoble, M.; Poutissou, R.

1990-10-01

A wide bandwidth transient digitizer based on a recently produced gallium arsenide charged coupled device is under development. The CCDs have 128 pixels and operate at 500 MHz. Initial testing of prototype modules in Experiment 787 at Brookhaven National Laboratory is reported. (Author) (8 refs., 10 figs.)

Design Considerations for the LHC 200 MHz RF System

CERN Document Server

Boussard, Daniel; Kindermann, H P; Linnecar, Trevor Paul R; Marque, S; Tückmantel, Joachim

2000-01-01

The longitudinal beam transfer from the SPS into the LHC 400 MHz buckets will not be free of losses without a lower frequency capture system and a fast longitudinal damping system in LHC. We present a complete study of a combined system using four identical copper cavities at 200 MHz delivering 3 MV total CW voltage and having still enough bandwidth to achieve fast longitudinal damping. The shape of a cavity was designed according to the accelerating mode performance, its tuning and the higher order mode spectrum with respect to the LHC beam lines and their possible attenuation. The possibility to park the cavities during coast was included. The local heat load and the corresponding cooling water distribution as well as deformations were studied and techniques to build the cavity with all ports at low cost are proposed. The parameters of the RF generators, couplers and detuning are determined. Simulations of the total LHC RF system incorporating real delays, generator bandwidth and the control loops confirm t...

Polarized positrons in Jefferson lab electron ion collider (JLEIC)

Science.gov (United States)

Lin, Fanglei; Grames, Joe; Guo, Jiquan; Morozov, Vasiliy; Zhang, Yuhong

2018-05-01

The Jefferson Lab Electron Ion Collider (JLEIC) is designed to provide collisions of electron and ion beams with high luminosity and high polarization to reach new frontier in exploration of nuclear structure. The luminosity, exceeding 1033 cm-2s-1 in a broad range of the center-of-mass (CM) energy and maximum luminosity above 1034 cm-2s-1, is achieved by high-rate collisions of short small-emittance low-charge bunches with proper cooling of the ion beam and synchrotron radiation damping of the electron beam. The polarization of light ion species (p, d, 3He) and electron can be easily preserved, manipulated and maintained by taking advantage of the unique figure-8 shape rings. With a growing physics interest, polarized positron-ion collisions are considered to be carried out in the JLEIC to offer an additional probe to study the substructure of nucleons and nuclei. However, the creation of polarized positrons with sufficient intensity is particularly challenging. We propose a dedicated scheme to generate polarized positrons. Rather than trying to accumulate "hot" positrons after conversion, we will accumulate "cold" electrons before conversion. Charge accumulation additionally provides a novel means to convert high repetition rate (>100 MHz) electron beam from the gun to a low repetition rate (<100 MHz) positron beam for broad applications. In this paper, we will address the scheme, provide preliminary estimated parameters and explain the key areas to reach the desired goal.

Electronic theses and dissertations: a review of this valuable resource for nurse scholars worldwide.

Science.gov (United States)

Goodfellow, L M

2009-06-01

A worldwide repository of electronic theses and dissertations (ETDs) could provide worldwide access to the most up-to-date research generated by masters and doctoral students. Until that international repository is established, it is possible to access some of these valuable knowledge resources. ETDs provide a technologically advanced medium with endless multimedia capabilities that far exceed the print and bound copies of theses and dissertations housed traditionally in individual university libraries. CURRENT USE: A growing trend exists for universities worldwide to require graduate students to submit theses or dissertations as electronic documents. However, nurse scholars underutilize ETDs, as evidenced by perusing bibliographic citation lists in many of the research journals. ETDs can be searched for and retrieved through several digital resources such as the Networked Digital Library of Theses and Dissertations (http://www.ndltd.org), ProQuest Dissertations and Theses (http://www.umi.com), the Australasian Digital Theses Program (http://adt.caul.edu.au/) and through individual university web sites and online catalogues. An international repository of ETDs benefits the community of nurse scholars in many ways. The ability to access recent graduate students' research electronically from anywhere in the world is advantageous. For scholars residing in developing countries, access to these ETDs may prove to be even more valuable. In some cases, ETDs are not available for worldwide access and can only be accessed through the university library from which the student graduated. Public access to university library ETD collections is not always permitted. Nurse scholars from both developing and developed countries could benefit from ETDs.

The quiet Sun brightness temperature at 408 MHz

International Nuclear Information System (INIS)

Avignon, Y.; Lantos, P.; Palagi, F.; Patriarchi, P.

1975-01-01

The flux of the radio quiet Sun and the brightness temperature at 408 MHz (73cm) are derived from measurements with the E-W Nancay interferometer and the E-W arm of the Medicina North Cross. It is shown that the lowest envelopes, which defined the radio quiet Sun, correspond to transits of extended coronal holes across the disk of the Sun. (Auth.)

75 FR 9210 - Wireless Telecommunications Bureau Seeks Comment on Petition for Rulemaking Regarding 700 MHz...

Science.gov (United States)

2010-03-01

[email protected] or call the Consumer & Governmental Affairs Bureau at 202-418-0530 (Voice), 202-418-0432 (TTY... the Commission to ``assure that consumers will have access to all paired 700 MHz spectrum that the Commission licenses, to act so that the entire 700 MHz band will develop in a competitive fashion, and to...

Calibration of SAR probes in waveguide at 900 MHz

International Nuclear Information System (INIS)

Jokela, K.; Puranen, L.; Hyysalo, P.

1998-01-01

The radiation safety tests for hand-held mobile phones require precise calibration of the small electric field probes used for the measurement of SAR in phantoms simulating the human body. In this study a calibration based on a rectangular waveguide was developed for SAR calibrations at 900 MHz

MEMS Tunable Antennas to Address LTE 600 MHz-bands

DEFF Research Database (Denmark)

Barrio, Samantha Caporal Del; Morris, Art; Pedersen, Gert Frølund

2015-01-01

The broadcast television spectrum around 600 MHz has been freed in the united states and will be put for auction to wireless carriers in 2015. The newest generation of mobile communication standards will be deployed on these newly available bands, to provide mobile device users with an enhanced c...

The Use of a Solid State Analog Television Transmitter as a Superconducting Electron Gun Power Amplifier

Energy Technology Data Exchange (ETDEWEB)

J.G. Kulpin, K.J. Kleman, R.A. Legg

2012-07-01

A solid state analog television transmitter designed for 200 MHz operation is being commissioned as a radio frequency power amplifier on the Wisconsin superconducting electron gun cavity. The amplifier consists of three separate radio frequency power combiner cabinets and one monitor and control cabinet. The transmitter employs rugged field effect transistors built into one kilowatt drawers that are individually hot swappable at maximum continuous power output. The total combined power of the transmitter system is 33 kW at 200 MHz, output through a standard coaxial transmission line. A low level radio frequency system is employed to digitally synthesize the 200 MHz signal and precisely control amplitude and phase.

Library resources on the Internet

Science.gov (United States)

Buchanan, Nancy L.

1995-07-01

Library resources are prevalent on the Internet. Library catalogs, electronic books, electronic periodicals, periodical indexes, reference sources, and U.S. Government documents are available by telnet, Gopher, World Wide Web, and FTP. Comparatively few copyrighted library resources are available freely on the Internet. Internet implementations of library resources can add useful features, such as full-text searching. There are discussion lists, Gophers, and World Wide Web pages to help users keep up with new resources and changes to existing ones. The future will bring more library resources, more types of library resources, and more integrated implementations of such resources to the Internet.

76 FR 62309 - Implementing a Nationwide, Broadband, Interoperable Public Safety Network in the 700 MHz Band

Science.gov (United States)

2011-10-07

... the 700 MHz Band AGENCY: Federal Communications Commission. ACTION: Final rule. SUMMARY: In this... spectrum of the 700 MHz band. The Commission dismissed the request, but clarified that a reasonably broad... personnel including, but not limited to, activities of police, fire and medical emergency first responders...

Study of electron beam energy conversion at gyrocon-linear accelerator facility

International Nuclear Information System (INIS)

Karliner, M.M.; Makarov, I.G.; Ostreiko, G.N.

2004-01-01

A gyrocon together with the high-voltage 1.5 MeV accelerator ELIT-3A represents a power generator at 430 MHz serving for linear electron accelerator pulse driving. The facility description and results of calorimetric measurements of ELIT-3A electron beam power and accelerated beam at the end of accelerator are presented in the paper. The achieved energy conversion efficiency is about 55%

FIRST EXPERIMENTAL RESULTS FROM DEGAS, THE QUANTUM LIMITED BRIGHTNESS ELECTRON SOURCE

International Nuclear Information System (INIS)

Zolotorev, Max S.; Commins, Eugene D.; Oneill, James; Sannibale, Fernando; Tremsin, Anton; Wan, Weishi

2008-01-01

The construction of DEGAS (DEGenerate Advanced Source), a proof of principle for a quantum limited brightness electron source, has been completed at the Lawrence Berkeley National Laboratory. The commissioning and the characterization of this source, designed to generate coherent single electron 'bunches' with brightness approaching the quantum limit at a repetition rate of few MHz, has been started. In this paper the first experimental results are described

ELECTRONIC EDUCATIONAL RESOURCES FOR ONLINE SUPPORT OF MODERN CHEMISTRY CLASSES IN SPECIALIZED SCHOOL

Directory of Open Access Journals (Sweden)

Maria D. Tukalo

2013-09-01

Full Text Available This article contains material of some modern electronic educational resources that can be used via the Internet to support the modern chemistry classes in specialized school. It was drawn attention to the educational chemical experiments as means of knowledge; simulated key motivational characteristics to enhance students interest for learning subjects, their cognitive and practical activity in the formation of self-reliance and self-creative; commented forecasts for creating of conditions to enhance the creative potential of students in a modern learning environment.

Development of 650 MHz solid state RF amplifier for proton accelerator

International Nuclear Information System (INIS)

Jain, Akhilesh; Sharma, Deepak; Gupta, Alok; Tiwari, Ashish; Rao, Nageswar; Sekar, Vasanthi; Lad, M.; Hannurkar, P.R.; Gupta, P.D.

2011-01-01

Design and development of 30 kW high powers RF source at 650 MHz, using solid RF state technology, has been initiated at RRCAT. The indigenous technology development efforts will be useful for the proposed high power proton accelerators for SNS/ADS applications. In this 650 MHz amplifier scheme, 30 kW CW RF power will be generated using modular combination of 8 kW amplifier units. Necessary studies were carried out for device selection, choice of amplifier architecture and design of high power combiners and dividers. Presently RF amplifier delivering 250 W at 650 MHz has been fabricated and tested. Towards development of high power RF components, design and engineering prototyping of 16-port power combiner, directional coupler and RF dummy loads has been completed. The basic 8 kW amplifier unit is designed to provide power gain of 50 dB, bandwidth of 20 MHz and spurious response below 30 dB from fundamental signal. Based on the results of circuit simulation studies and engineering prototyping of amplifier module, two RF transistor viz. MRF3450 and MRF 61K were selected as solid state active devices. Impedance matching network in amplifier module is designed using balanced push pull configuration with transmission line BALUN. Due to high circulating current near drain side, metal clad RF capacitors were selected which helps in avoiding hot spot from output transmission path, ensuring continuous operation at rated RF power without damage to RF board. 350 W circulator is used to protect the RF devices from reflected power. Based on the prototype design and measured performance, one of these RF transistors will be selected to be used as workhorse for all amplifier modules. Two amplifier modules are mounted on water cooled copper heat-sink ensuring proper operating temperature for reliable and safe operation of amplifier. Also real time control system and data logger has been developed to provide DAQ and controls in each rack. For power combining and power measurement

Selection and Evaluation of Electronic Resources

Directory of Open Access Journals (Sweden)

Doğan Atılgan

2013-11-01

Full Text Available Publication boom and issues related to controlling and accession of printed sources have created some problems after World War II. Consequently, publishing industry has encountered the problem of finding possible solution for emerged situation. Industry of electronic publishing has started to improve with the rapid increase of the price of printed sources as well as the problem of publication boom. The first effects of electronic publishing were appeared on the academic and scholarly publications then electronic publishing became a crucial part of all types of publications. As a result of these developments, collection developments and service policies of information centers were also significantly changed. In this article, after a general introduction about selection and evaluation processes of electronic publications, the subscribed databases by a state and a privately owned university in Turkey and their usage were examined.

Designing a fractal antenna of 2400 MHz

International Nuclear Information System (INIS)

Miranda Hamburger, Fabio

2012-01-01

The design of a fractal antenna with 2400 MHz of frequency has been studied. The fractal used is described by Waclaw Spierpi.ski. The initial figure, also known as seed, is divided using equilateral triangles with the aim of obtaining a perimeter similar to a meaningful portion of wave length. The use of λ to establish an ideal perimeter has reduced the radiation resistance. The adequate number of iterations needed to design the antenna is calculated based on λ. (author) [es

An Exploratory study on the use of LibAnswers to Resolve, Track and Monitor Electronic Resources Issues: The KAUST Library experience

KAUST Repository

Ramli, Rindra M.

2017-01-01

An Exploratory study on KAUST library use of LibAnswers in resolving electronic resources questions received in LibAnswers. It describes the findings of the questions received in LibAnswers. The author made suggestions based on the findings to improve the reference services in responding to e-resources questions.

An Exploratory study on the use of LibAnswers to Resolve, Track and Monitor Electronic Resources Issues: The KAUST Library experience

KAUST Repository

Ramli, Rindra M.

2017-05-03

An Exploratory study on KAUST library use of LibAnswers in resolving electronic resources questions received in LibAnswers. It describes the findings of the questions received in LibAnswers. The author made suggestions based on the findings to improve the reference services in responding to e-resources questions.

Charge domain filter operating up to 20 MHz clock frequency

NARCIS (Netherlands)

Gal, R.A.J.; Wallinga, Hans

1983-01-01

An analog sampled data low pass third order Butterworth filter has been realised in a buried channel CCD technology. This Charge Domain Filter, composed of transversal and recursive CCD filter sections, has been tested at clock frequencies up to 20 MHz.

Phase loop bandwidth measurements on the advanced photon source 352 MHz rf systems

International Nuclear Information System (INIS)

Horan, D.; Nassiri, A.; Schwartz, C.

1997-01-01

Phase loop bandwidth tests were performed on the Advanced Photon Source storage ring 352-MHz rf systems. These measurements were made using the HP3563A Control Systems Analyzer, with the rf systems running at 30 kilowatts into each of the storage ring cavities, without stored beam. An electronic phase shifter was used to inject approximately 14 degrees of stimulated phase shift into the low-level rf system, which produced measureable response voltage in the feedback loops without upsetting normal rf system operation. With the PID (proportional-integral-differential) amplifier settings at the values used during accelerator operation, the measurement data revealed that the 3-dB response for the cavity sum and klystron power-phase loops is approximately 7 kHz and 45 kHz, respectively, with the cavities the primary bandwidth-limiting factor in the cavity-sum loop. Data were taken at various PID settings until the loops became unstable. Crosstalk between the two phase loops was measured

The level of the usage of the human resource information system and electronic recruitment in Croatian companies

Directory of Open Access Journals (Sweden)

Snježana Pivac

2014-12-01

Full Text Available Performing business according to contemporary requirements influences companies for continuous usage of modern managerial tools, such as a human resource information system (HRIS and electronic recruitment (ER. Human resources have been recognised as curtail resources and the main source of a competitive advantage in creation of successful business performance. In order to attract and select the top employees, companies use quality information software for attracting internal ones, and electronic recruitment for attracting the best possible external candidates. The main aim of this paper is to research the level of the usage of HRIS and ER within medium-size and large Croatian companies. Moreover, the additional aim of this paper is to evaluate the relationship among the usage of these modern managerial tools and the overall success of human resource management within these companies. For the purpose of this paper, primary and secondary research has been conducted in order to reveal the level of the usage of HRIS and ER as well as the overall success of human resource management in Croatian companies. The companies’ classification (HRIS and ER is done by using the non-hierarchical k-means cluster method as well as the nonparametric Kruskal Wallis test. Further, the companies are ranked by the multicriteria PROMETHEE method. Relevant nonparametric tests are used for testing the overall companies’ HRM. Finally, binary logistic regression is estimated, relating binary variable HRM and HRIS development. After detailed research, it can be concluded that large Croatian companies apply HRIS in majority (with a positive relation to HRM performance, but still require certain degrees of its development.

The electronic encapsulation of knowledge in hydraulics, hydrology and water resources

Science.gov (United States)

Abbott, Michael B.

The rapidly developing practice of encapsulating knowledge in electronic media is shown to lead necessarily to the restructuring of the knowledge itself. The consequences of this for hydraulics, hydrology and more general water-resources management are investigated in particular relation to current process-simulation, real-time control and advice-serving systems. The generic properties of the electronic knowledge encapsulator are described, and attention is drawn to the manner in which knowledge 'goes into hiding' through encapsulation. This property is traced in the simple situations of pure mathesis and in the more complex situations of taxinomia using one example each from hydraulics and hydrology. The consequences for systems architectures are explained, pointing to the need for multi-agent architectures for ecological modelling and for more general hydroinformatics systems also. The relevance of these developments is indicated by reference to ongoing projects in which they are currently being realised. In conclusion, some more general epistemological aspects are considered within the same context. As this contribution is so much concerned with the processes of signification and communication, it has been partly shaped by the theory of semiotics, as popularised by Eco ( A Theory of Semiotics, Indiana University, Bloomington, 1977).

Q0 Degradation of LANL 700-MHZ β = 0.64 Elliptical Cavities and ANL 340 MHZ Spoke Cavities

International Nuclear Information System (INIS)

Tajima, Tsuyoshi; Chan, Kwok-Chi D.; Edwards, Randall L.; Gentzlinger, Robert C.; Kelley, John Patrick; Krawczyk, Frank L.; Madrid, Michael A.; Montoya, Debbie I.; Schrage, Dale L.; Shapiro, Alan H.

2002-01-01

The quality factor (Q 0 ) of most of the six LANL β = 0.64 700-MHz 5-cell elliptical cavities starts to drop at E acc = 8-10 MV/m, which may be related to multipacting. Residual resistances of these cavities were measured to be 5.0-7.6 n(Omega). The sensitivity of surface resistance to the external magnetic field was measured to be 0.22 n(Omega)/mG. Q disease tests have shown no significant Q 0 degradation for both elliptical cavities and a spoke cavity with our 100 (micro)m BCP.

An analog memory integrated circuit for waveform sampling up to 900 MHz

International Nuclear Information System (INIS)

Haller, G.M.; Wooley, B.A.

1994-01-01

The potential of switched-capacitor technology for acquiring analog signals in high-energy physics (HEP) applications has been demonstrated in a number of analog memory designs. The design and implementation of a switched-capacitor memory suitable for capturing high-speed analog waveforms is described. Highlights of the presented circuit are a 900 MHz sampling frequency (generated on chip), input signal independent cell pedestal and sampling instances, and cell gains that are insensitive to component sizes. A two-channel version of the memory with 32 cells for each channel has been integrate in a 2-μm complementary metal oxide semiconductor (CMOS) process with polysilicon-to-polysilicon capacitors. The measured rms cell response variation in a channel after cell pedestal subtraction is less than 0.3 mV across the full input signal range. The cell-to-cell gain matching is better than 0.01% rms, and the nonlinearity is less than 0.03% for a 2.5-V input range. The dynamic range of the memory exceeds 13 bits, and the peak signal-to-(noise + distortion) ratio for a 21.4 MHz sine wave sampled at 900 MHz is 59 dB

The Alice dimuon trigger: overview and electronics prototypes

International Nuclear Information System (INIS)

Arnaldi, R.; Baldit, A.; Barret, V.; Bastid, N.

2000-01-01

ALICE is the LHC experiment (2005) dedicated to the study of heavy ion collisions. Amongst the ALICE sub-detectors, the muon spectrometer will investigate the dimuon production from heavy resonance (J/ψ,γ) decays, which is believed to be a promising signature of the QGP (quark Gluon Plasma) formation. For maximum efficiency of the spectrometer, a dedicated dimuon trigger is presently built. The detector part itself is based on RPCs operated in streamer mode and is the topic of another contribution to this conference. This paper gives the principle and the simulated performances of the trigger and is also focussed on the description of the electronics prototypes and future developments. The RPCs are read-out by X and Y orthogonal strips: the front-end chips are presently developed. The signals are sent to the trigger electronics which basically performs a pt cut on the tracks to reduce the background. A prototype of fast (decision time 200 ns) programmable electronics working in a pipelined mode at 40 MHz has been built and tested. This prototype handles simultaneously 160 digital information from the strips. The tests of the trigger card have required the construction of a pattern generator (160 bits at 40 MHz). (author)

RESEARCH OF INFLUENCE OF QUALITY OF ELECTRONIC EDUCATIONAL RESOURCES ON QUALITY OF TRAINING WITH USE OF DISTANCE TECHNOLOGIES

Directory of Open Access Journals (Sweden)

H. M. Kravtsov

2013-03-01

Full Text Available Communication improving of educational processes requires today new approaches to the management arrangements and forming of educational policy in the field of distance learning, which is based on the use of modern information and communication technologies. An important step in this process is the continuous monitoring of the development and implementation of information technology and, in particular, the distance learning systems in higher educational establishments. The main objective of the monitoring is the impact assessment on the development of distance learning following the state educational standards, curricula, methodical and technical equipment and other factors; factors revelation that influence the implementation and outcomes of distance learning; results comparison of educational institution functioning and distance education systems in order to determine the most efficient ways of its development. The paper presents the analysis results of the dependence of the quality of educational services on the electronic educational resources. Trends in educational services development was studied by comparing the quality influence of electronic educational resources on the quality of educational services of higher pedagogical educational institutions of Ukraine as of 2009-2010 and 2012-2013. Generally, the analysis of the survey results allows evaluating quality of the modern education services as satisfactory and it can be said that almost 70% of the success of their future development depends on the quality of the used electronic educational resources and distance learning systems in particular.

A low-power ASK demodulator for inductively coupled implantable electronics

DEFF Research Database (Denmark)

Gudnason, Gunnar

2000-01-01

An amplitude shift keying (ASK) demodulator is presented which is suitable for implantable electronic devices that are powered through an inductive link. The demodulator has been tested with carrier frequencies in the range 1-15 MHz, covering most commonly used frequencies. Data rates up to several...

Tracking the Flow of Resources in Electronic Waste - The Case of End-of-Life Computer Hard Disk Drives.

Science.gov (United States)

Habib, Komal; Parajuly, Keshav; Wenzel, Henrik

2015-10-20

Recovery of resources, in particular, metals, from waste flows is widely seen as a prioritized option to reduce their potential supply constraints in the future. The current waste electrical and electronic equipment (WEEE) treatment system is more focused on bulk metals, where the recycling rate of specialty metals, such as rare earths, is negligible compared to their increasing use in modern products, such as electronics. This study investigates the challenges in recovering these resources in the existing WEEE treatment system. It is illustrated by following the material flows of resources in a conventional WEEE treatment plant in Denmark. Computer hard disk drives (HDDs) containing neodymium-iron-boron (NdFeB) magnets were selected as the case product for this experiment. The resulting output fractions were tracked until their final treatment in order to estimate the recovery potential of rare earth elements (REEs) and other resources contained in HDDs. The results further show that out of the 244 kg of HDDs treated, 212 kg comprising mainly of aluminum and steel can be finally recovered from the metallurgic process. The results further demonstrate the complete loss of REEs in the existing shredding-based WEEE treatment processes. Dismantling and separate processing of NdFeB magnets from their end-use products can be a more preferred option over shredding. However, it remains a technological and logistic challenge for the existing system.

Nonequilibrium atmospheric pressure plasma jet using a combination of 50 kHz/2 MHz dual-frequency power sources

International Nuclear Information System (INIS)

Zhou, Yong-Jie; Yuan, Qiang-Hua; Li, Fei; Wang, Xiao-Min; Yin, Gui-Qin; Dong, Chen-Zhong

2013-01-01

An atmospheric pressure plasma jet is generated by dual sinusoidal wave (50 kHz and 2 MHz). The dual-frequency plasma jet exhibits the advantages of both low frequency and radio frequency plasmas, namely, the long plasma plume and the high electron density. The radio frequency ignition voltage can be reduced significantly by using dual-frequency excitation compared to the conventional radio frequency without the aid of the low frequency excitation source. A larger operating range of α mode discharge can be obtained using dual-frequency excitation which is important to obtain homogeneous and low-temperature plasma. A larger controllable range of the gas temperature of atmospheric pressure plasma could also be obtained using dual-frequency excitation

Design and testing of a 750 MHz CW-EPR digital console for small animal imaging

Science.gov (United States)

Sato-Akaba, Hideo; Emoto, Miho C.; Hirata, Hiroshi; Fujii, Hirotada G.

2017-11-01

This paper describes the development of a digital console for three-dimensional (3D) continuous wave electron paramagnetic resonance (CW-EPR) imaging of a small animal to improve the signal-to-noise ratio and lower the cost of the EPR imaging system. A RF generation board, an RF acquisition board and a digital signal processing (DSP) & control board were built for the digital EPR detection. Direct sampling of the reflected RF signal from a resonator (approximately 750 MHz), which contains the EPR signal, was carried out using a band-pass subsampling method. A direct automatic control system to reduce the reflection from the resonator was proposed and implemented in the digital EPR detection scheme. All DSP tasks were carried out in field programmable gate array ICs. In vivo 3D imaging of nitroxyl radicals in a mouse's head was successfully performed.

Characteristics of SiO{sub 2} etching with a C{sub 4}F{sub 8}/Ar/CHF{sub 3}/O{sub 2} gas mixture in 60-MHz/2-MHz dual-frequency capacitively coupled plasmas

Energy Technology Data Exchange (ETDEWEB)

Jeon, M. H.; Kang, S. K.; Park, J. Y.; Yeom, G. Y. [Sungkyunkwan University, Suwon (Korea, Republic of)

2011-11-15

Nanoscale SiO{sub 2} contact holes were etched by using C{sub 4}F{sub 8}/CHF{sub 3}/O{sub 2}/Ar gas mixtures in dual frequency capacitively coupled plasmas (DF-CCPs) where a 60-MHz source power was applied to the top electrode while a 2-MHz bias power was applied to the bottom electrode. The initial increase in the CHF{sub 3} gas flow rate at a fixed CHF{sub 3}+O{sub 2} flow rate increased the SiO{sub 2} etch rate as well as SiO{sub 2} etch selectivity over that of the amorphous carbon layer (ACL). When the high-frequency (HF) power was increased both SiO{sub 2} etch rate and the etch selectivity over ACL were increased. For a 300 W/500 W power ratio of 60-MHz HF power/ 2-MHz low-freqeuncy (LF) and a gas mixture of Ar (140 sccm) /C{sub 4}F{sub 8} (30 sccm) /CHF{sub 3} (25 sccm) /O{sub 2} (5 sccm) while maintaining 20 mTorr, an anisotropic etch profile with an SiO{sub 2} etch rate of 3350 A/min and an etch selectivity of higher than 6 over ACL could be obtained.

Development of 400- to 450-MHz RFQ resonator-cavity mechanical designs

International Nuclear Information System (INIS)

Hansborough, L.D.

1982-01-01

In the development of the radio-frequency quadrupole (RFQ) linac, the resonator cavity's mechanical design may be a challenge similar in magnitude to that of the development of the accelerator structure itself. Experience with the all-copper 425-MHz RFQ proof-of-principle linac has demonstrated that the resonator cavity must be structurally stiff and easily tunable. This experience has led to development of copper-plated steel structures having vanes that may be moved within a cylinder for tuning. Design of a flexible vane-to-cylinder radio-frequency (rf) joint, the vane, and the cylinder has many constraints dictated by the small-diameter cavities in the 400-MHz-frequency region. Two types of flexible, mechanical vane-to-cylinder rf joints are being developed at Los Alamos: the C-seal and the rf clamp-joint

Diagnostic for a high-repetition rate electron photo-gun and first measurements

Science.gov (United States)

Filippetto, D.; Doolittle, L.; Huang, G.; Norum, E.; Portmann, G.; Qian, H.; Sannibale, F.

2015-05-01

The APEX electron source at LBNL combines the high-repetition-rate with the high beam brightness typical of photoguns, delivering low emittance electron pulses at MHz frequency. Proving the high beam quality of the beam is an essential step for the success of the experiment, opening the doors of the high average power to brightness-hungry applications as X-Ray FELs, MHz ultrafast electron diffraction etc.. As first step, a complete characterization of the beam parameters is foreseen at the Gun beam energy of 750 keV. Diagnostics for low and high current measurements have been installed and tested, and measurements of cathode lifetime and thermal emittance in a RF environment with mA current performed. The recent installation of a double slit system, a deflecting cavity and a high precision spectrometer, allow the exploration of the full 6D phase space. Here we discuss the present layout of the machine and future upgrades, showing the latest results at low and high repetition rate, together with the tools and techniques used.

Hybrid Circuit QED with Electrons on Helium

Science.gov (United States)

Yang, Ge

Electrons on helium (eHe) is a 2-dimensional system that forms naturally at the interface between superfluid helium and vacuum. It has the highest measured electron mobility, and long predicted spin coherence time. In this talk, we will first review various quantum computer architecture proposals that take advantage of these exceptional properties. In particular, we describe how electrons on helium can be combined with superconducting microwave circuits to take advantage of the recent progress in the field of circuit quantum electrodynamics (cQED). We will then demonstrate how to reliably trap electrons on these devices hours at a time, at millikelvin temperatures inside a dilution refrigerator. The coupling between the electrons and the microwave resonator exceeds 1 MHz, and can be reproduced from the design geometry using our numerical simulation. Finally, we will present our progress on isolating individual electrons in such circuits, to build single-electron quantum dots with electrons on helium.

Survey of conditions for artificial aurora experiments by the second electron gyro-harmonic at EISCAT Tromsø using dynasonde data

Science.gov (United States)

Tsuda, T. T.; Rietveld, M. T.; Kosch, M. J.; Oyama, S.; Ogawa, Y.; Hosokawa, K.; Nozawa, S.; Kawabata, T.; Mizuno, A.

2018-06-01

We report a brief survey of matching conditions for artificial aurora optical experiments utilizing the second electron gyro-harmonic (2.7-MHz frequency) in F region heating with O-mode at the EISCAT Tromsø site using dynasonde data from 2000 to 2017. Our survey indicates the following: The possible conditions for successful artificial aurora experiments are concentrated on twilight hours in both evening and morning, compared with late night hours; the possible conditions appear in fall, winter, and spring, while there is no chance in summer, and the month-to-month variation among fall, winter, and spring is not so clear; the year-to-year variation is well correlated with the solar activity. These characteristics in the case of 2.7-MHz frequency are basically similar to those previously reported in the case of 4-MHz frequency. However, the number of days meeting the possible condition in the case of 2.7-MHz frequency is obviously large, compared with that in the case of 4-MHz frequency. In particular, unlike the 4-MHz frequency operation, the 2.7-MHz frequency operation can provide many chances for successful artificial aurora experiments even during the solar minimum.

MHz repetition rate solid-state driver for high current induction accelerators

International Nuclear Information System (INIS)

Brooksby, C; Caporaso, G; Goerz, D; Hanks, R; Hickman, B; Kirbie, H; Lee, B; Saethre, R.

1999-01-01

A research team from the Lawrence Livermore National Laboratory and Bechtel Nevada Corporation is developing an all solid-state power source for high current induction accelerators. The original power system design, developed for heavy-ion fusion accelerators, is based on the simple idea of using an array of field effect transistors to switch energy from a pre-charged capacitor bank to an induction accelerator cell. Recently, that idea has been expanded to accommodate the greater power needs of a new class of high-current electron accelerators for advanced radiography. For this purpose, we developed a 3-stage induction adder that uses over 4,000 field effect transistors to switch peak voltages of 45 kV at currents up to 4.8 kA with pulse repetition rates of up to 2 MHz. This radically advanced power system can generate a burst of five or more pulses that vary from 200 ns to 2 ampersand micro;s at a duty cycle of up to 25%. Our new source is precise, robust, flexible, and exceeds all previous drivers for induction machines by a factor of 400 in repetition rate and a factor of 1000 in duty cycle

Control-grid electron gun as a source of modulated electron beam for a collective accelerator

International Nuclear Information System (INIS)

Bakumenko, A.A.; Belikov, V.V.; Zvyagintsev, A.V.; Lyul'chenko, V.I.; Lymar', A.G.; Martynenko, P.A.; Suryadnyj, A.V.

1989-01-01

Structure is described and experimental results of investigations into an electron gun with transverse beam compression and control grid are presented. The pulse trailing edge is formed by a sectioned discharger. A modulated electron beam with the following parameters: 110 keV beam energy, 70 A current amplitude, 3-8 MHz modulation frequency, 100% modulation depth, ≅8-6 mm minimal beam diameter, ≅ 10μs pulse duration, 3% pulse top non-uniformity, more than 200 compression degree is obtained when introducing the positive feedback in auto-generator regime to the gun supply circuit. Further it is supposed to use the developed electron gun for heavy ion acceleration by a field of space charge of a modulated electron beam in a corrugated liner. It should be underlined that power supply of such an accelerator does not require powerful outside HF generator. 5 refs.; 1 fig

FDTD calculations of SAR for child voxel models in different postures between 10 MHz and 3 GHz.

Science.gov (United States)

Findlay, R P; Lee, A-K; Dimbylow, P J

2009-08-01

Calculations of specific energy absorption rate (SAR) have been performed on the rescaled NORMAN 7-y-old voxel model and the Electronics and Telecommunications Research Institute (ETRI) child 7-y-old voxel model in the standing arms down, arms up and sitting postures. These calculations were for plane-wave exposure under isolated and grounded conditions between 10 MHz and 3 GHz. It was found that there was little difference at each resonant frequency between the whole-body averaged SAR values calculated for the NORMAN and ETRI 7-y-old models for each of the postures studied. However, when compared with the arms down posture, raising the arms increased the SAR by up to 25%. Electric field values required to produce the International Commission on Non-Ionizing Radiation Protection and Institute of Electrical and Electronic Engineers public basic restriction were calculated, and compared with reference levels for the different child models and postures. These showed that, under certain worst-case exposure conditions, the reference levels may not be conservative.

Photocathode electron linac for AFEL

International Nuclear Information System (INIS)

Wood, R.L.; Young, L.M.; Aikin, D.J.; Clark, W.L.; DePaula, R.F.; Gladwell, C.; Ledford, J.E.; Martinez, F.A.; Stovall, J.E.

1992-01-01

A compact, high brightness accelerator was designed and fabricated by Los Alamos National Laboratory for use in the Advanced Free Electron Laser facility. A brazed copper, 1300 MHz, 20 MeV structure is suspended within a thermally insulating vacuum vessel. Integral cooling passages allow introduction of cooling water for normal operation, or liquid nitrogen for cryogenic operation. Its exceptional beam quality is expected to enhance the performance of the FEL experiments planned for the AFEL facility

Design and Realization of FIR Filter for Inter Satellite Link at 50-90 MHZ Frequency using FPGA

Directory of Open Access Journals (Sweden)

Yuyu Wahyu

2016-12-01

Full Text Available In this paper, design and realization of FIR filter with a bandwidth of 40 MHz at 50-90 MHz frequency has been proposed. The design was destined to be implemented on the Inter Satellite Links (ISL. This kind of filter had been selected due to a need in linear phase responseon the ISL data communication. Equiripple method was used to design the filter becauseof its reliability in minimizing the magnitude errors. The design of this FIR filter was conducted with theoretical calculation and simulation using the R2012b Matlab. For the implementation, FPGA was used with a VHDL as the programming language with a help of Xilinx ISE Design Suite 14.5. Simulation results in Matlab and Simulink indicated that the filter design could be well implemented on ISL at frequency of 50 MHz - 90 MHz with stopband of 60 db. The phase responseresult of the realized design is quite linear so that the filter is suitable for data communication on the ISL.

Observation of suprathermal electron fluxes during ionospheric modification experiments

International Nuclear Information System (INIS)

Fejer, J.A.; Sulzer, M.P.

1987-01-01

The temporal behavior of backscatter by ionospheric Langmuir waves was observed with the 430-MHz radar at Arecibo while a powerful HF wave was cycled 2 s on, 3 s off. The time resolution was 0.1 s. Late at night, in the absence of photoelectrons, using an HF equivalent radiated power of 80 MW at 3.175 MHz, the initial enhancement of about 6% above system noise of the backscattered power with Doppler shifts between -3.75 and -3.85 MHz was reached about 0.25 s after switching on the HF transmitter. In the following second the enhancement gradually decreased to about 3% and remained there until switching off. During the late afternoon, in the presence of photoelectrons, using the same HF power at 5.1 MHz, an initial enhancement by 25% of the backscattered power with Doppler shifts between -5.25 and -5.35 MHz appeared within less than 0.1 s after switching on the HF transmitter. The incoherent backscatter by Langmuir waves enhanced by photoelectrons was already above system noise by a factor greatly in excess of 10 before switching on the HF transmitter; the 25% enhancement thus corresponds to an enhancement greatly in excess of 250% above system noise. The enhancement drops to less than one tenth of its original value in less than a second. The nighttime effect is attributed to multiple acceleration of electrons from the high-energy tail of the Maxwellian distribution. The daytime effect is believed to be due to a modification in the distribution function of photoelectrons

Experimental Evaluation of Several Key Factors Affecting Root Biomass Estimation by 1500 MHz Ground-Penetrating Radar

Directory of Open Access Journals (Sweden)

John C. Bain

2017-12-01

Full Text Available Accurate quantification of coarse roots without disturbance represents a gap in our understanding of belowground ecology. Ground penetrating radar (GPR has shown significant promise for coarse root detection and measurement, however root orientation relative to scanning transect direction, the difficulty identifying dead root mass, and the effects of root shadowing are all key factors affecting biomass estimation that require additional research. Specifically, many aspects of GPR applicability for coarse root measurement have not been tested with a full range of antenna frequencies. We tested the effects of multiple scanning directions, root crossover, and root versus soil moisture content in a sand-hill mixed oak community using a 1500 MHz antenna, which provides higher resolution than the oft used 900 MHz antenna. Combining four scanning directions produced a significant relationship between GPR signal reflectance and coarse root biomass (R2 = 0.75 (p < 0.01 and reduced variability encountered when fewer scanning directions were used. Additionally, significantly fewer roots were correctly identified when their moisture content was allowed to equalize with the surrounding soil (p < 0.01, providing evidence to support assertions that GPR cannot reliably identify dead root mass. The 1500 MHz antenna was able to identify roots in close proximity of each other as well as roots shadowed beneath shallower roots, providing higher precision than a 900 MHz antenna. As expected, using a 1500 MHz antenna eliminates some of the deficiency in precision observed in studies that utilized lower frequency antennas.

Very high frequency (beyond 100 MHz) PZT kerfless linear arrays.

Science.gov (United States)

Wu, Da-Wei; Zhou, Qifa; Geng, Xuecang; Liu, Chang-Geng; Djuth, Frank; Shung, K Kirk

2009-10-01

This paper presents the design, fabrication, and measurements of very high frequency kerfless linear arrays prepared from PZT film and PZT bulk material. A 12-microm PZT thick film fabricated from PZT-5H powder/solution composite and a piece of 15-microm PZT-5H sheet were used to fabricate 32-element kerfless high-frequency linear arrays with photolithography. The PZT thick film was prepared by spin-coating of PZT sol-gel composite solution. The thin PZT-5H sheet sample was prepared by lapping a PZT-5H ceramic with a precision lapping machine. The measured results of the 2 arrays were compared. The PZT film array had a center frequency of 120 MHz, a bandwidth of 60% with a parylene matching layer, and an insertion loss of 41 dB. The PZT ceramic sheet array was found to have a center frequency of 128 MHz with a poorer bandwidth (40% with a parylene matching layer) but a better sensitivity (28 dB insertion loss).

Band rejection filter for measurement of electron cyclotron emission during electron cyclotron heating

International Nuclear Information System (INIS)

Iwase, Makoto; Ohkubo, Kunizo; Kubo, Shin; Idei, Hiroshi.

1996-05-01

For the measurement of electron cyclotron emission from the high temperature plasma, a band rejection filter in the range of 40-60 GHz is designed to reject the 53.2 GHz signal with large amplitude from the gyrotron for the purpose of plasma electron heating. The filter developed with ten sets of three quarters-wavelength coupled by TE 111 mode of tunable resonant cavity has rejection of 50 dB and 3 dB bandwidth of 500 MHz. The modified model of Tschebysheff type for the prediction of rejection is proposed. It is confirmed that the measured rejection as a function of frequency agrees well with the experimental results for small coupling hole, and also clarified that the rejection ratio increases for the large coupling hole. (author)

Spectral intensity dependence an isotropy of sources stronger than 0.1 Jy at 2700 MHz

International Nuclear Information System (INIS)

Balonek, T.J.; Broderick, J.J.; Condon, J.J.; Crawford, D.F.; Jauncey, D.L.

1975-01-01

The 1000-foot (305 m) telescope of the National Astronomy and Ionosphere Center was used to measure 430 MHz flux densities of sources stronger than 0.1 Jy at 2700 MHz. Distributions of the resulting two-point spectral indices α (430, 2700) of sources in the intensity range 0.1less than or equal toS<0.35 Jy were compared with α (318, 2700) distributions of sources stronger than 0.35 Jy at 2700 MHz. The median normal-component spectral index and fraction of flat-spectrum sources in the faintest sample do not continue the previously discovered trend toward increased spectral steepening of faint sources. This result differs from the prediction of simple evolutionary cosmological models and therefore favors the alternative explanation that local source-density inhomogeneities are responsible for the observed intensity dependence of spectral indices

Robust digital design in organic electronics by dual-gate technology

NARCIS (Netherlands)

Myny, K.; Beenhakkers, M.J.; Aerle, N.A.J.M. van; Gelinck, G.H.; Genoe, J.; Dehaene, W.; Heremans, P.

2010-01-01

Research towards organic RFID tags is one of the drivers of organic electronics. In recent years, 64b organic RFID tags have been shown with capacitive coupling [1] and inductive coupling at 13.56 MHz [2,3]. Recent improvements were a 128b organic transponder chip with basic anti-collision and

Extraction of High Charge Electron Bunch from the ELSA RF Injector Comparison Between Simulation and Experiment

CERN Document Server

Lemaire, J; Binet, A; Lagniel, J M; Le Flanchec, V; Pichoff, N

2004-01-01

A new scheme based on a photoinjector and a RF linear accelerator operating at 352 MHz has been recently proposed as a versatile radiographic facility. Beam pulses of 60 ns duration contain 20 succesive electron bunches which will be extracted at 2.5 MeV from a photoinjector then accelerated through the next structure to the final energy of 51 MeV. Bunches carrying 100 nC are required for this purpose. As a first demonstrating step, 50 nC electron bunches have been produced and accelerated to 2.5 MeV with the 144 MHz ELSA photoinjector at Bruyères le Chatel. For this experiment, we compare the results and the numerical simulations made with PARMELA, MAGIC and MAFIA codes.

75 FR 9586 - Solicitation of Participation In and Public Meeting to Discuss Public Safety 700 MHz Broadband...

Science.gov (United States)

2010-03-03

... to local, state and tribal public safety agencies (i.e. fire, police, emergency medical services...\\ Implementing a Nationwide, Broadband, Interoperable Public Safety Network in the 700 MHz Band, FCC WT Docket No... technology deployed in the 700 MHz bands, specific to the needs of public safety agencies. NIST has developed...

Waveform digitizing at 500 MHz

International Nuclear Information System (INIS)

Atiya, M.; Ito, M.; Haggerty, J.; Ng, C.; Sippach, F.W.

1988-01-01

Experiment E787 at Brookhaven National Laboratory is designed to study the decay K + → π + ν/bar /nu// to a sensitivity of 2 /times/ 10 -10 . To achieve acceptable muon rejection it is necessary to couple traditional methods (range/energy/momentum correlation) with observation of the (π + → μ + ν, μ + → e + ν/bar /nu//) decay sequence in scintillator. We report on the design and construction of 200 channels of relatively low cost solid state waveform digitizers. The distinguishing features are: 8 bits dynamic range, 500 MHz sampling, zero suppression on the fly, deep memory (up to .5 msec), and fast readout time (100 μsec for the entire system). We report on data obtained during the February-May 1988 run showing performance of the system for the observation of the above decay. 8 figs

Waveform digitizing at 500 MHz

International Nuclear Information System (INIS)

Atiya, M.; Ito, M.; Haggerty, J.; Ng, C.; Sippach, F.W.

1988-01-01

Experiment E787 at Brookhaven National Laboratory is designed to study the decay K + → π + ν/bar /nu// to a sensitivity of 2 /times/ 10/sup /minus/10/. To achieve acceptable muon rejection it is necessary to couple traditional methods (range/energy/momentum correlation) with observation of the π + → μ + → e + ν/bar /nu// decay sequence in scintillator. We report on the design and construction of over 200 channels of relatively low cost solid state waveform digitizers. The distinguishing features are: 8 bits dynamic range, 500 MHz sampling, zero suppression on the fly, deep memory (up to .5 msec), and fast readout time (100 μsec for the entire system). We report on data obtained during the February--May 1988 run showing performance of the system for the observation of the above decay. 9 figs

Development of an optical inspection bench for the inspection of internal surfaces of 650 MHz SCRF cavities

International Nuclear Information System (INIS)

Kokil, S.V.; Kane, G.V.; Raghavendra, S.; Chauhan, S.K.; Rajpoot, D.S.; Oraon, B.; Om Prakash; Joshi, S.C.

2015-01-01

An optical inspection system has been developed for inspection of internal surfaces of 650 MHz superconducting RF cavities. The cavity parts are welded either using Electron Beam or Laser Beam Welding for making a good quality of weld joints. Surface defects like pits, scratches, welding spatters etc. on the internal surface of the cavity deteriorates cavity performance. Surface quality of the cavity equator joint plays an important role in the cavity performance. To study the quality of equator surface, the inspection bench offers high resolution images with a linear resolution of 45 m/pixel at a distance of ∼200 mm. The bench comprises of two major sub-systems, optical imaging system and cavity positioning system. A digital camera and multi coloured illumination system is used to obtain high resolution images. The camera is mounted inside a long cylindrical tube. The cylindrical tube can be inserted into a SCRF cavity. The length of the cylinder is long enough to inspect five-cell 650 MHz SCRF cavity. The cavity is placed on a set of PTFE rollers, which are mounted on a trolley. The cavity can be moved linearly with the help of ball screw-servomotor mechanism. The camera along with cylindrical tube can be rotated around its axis with a stepper motor to scan the cavity's internal surface. The paper presents the details about the optical inspection bench and optical inspection results. (author)

47 CFR 90.315 - Special provisions governing use of frequencies in the 476-494 MHz band (TV Channels 15, 16, 17...

Science.gov (United States)

2010-10-01

... in the 476-494 MHz band (TV Channels 15, 16, 17) in the Southern Louisiana-Texas Offshore Zone. 90... RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Authorization in the Band 470-512 MHz (UHF-TV Sharing) § 90.315 Special provisions governing use of frequencies in the 476-494 MHz band (TV Channels 15, 16...

Development of a high-power 432 MHz DTL

International Nuclear Information System (INIS)

Naito, F.; Kato, T.; Takasaki, E.; Yamazaki, Y.; Kawasumi, T.; Suzuki, K.; Iino, Y.

1992-01-01

A high-power model of a 432 MHz Drift-Tube Linac is under construction. It will accelerate H - ions from 3 to 5.4 MeV, and is a prototype of the DTL for the Japanese Hadron Project. Several new techniques have been developed for constructing the DTL: fabricating and assembling methods of permanent quadrupole magnet and a drift tube, alignment of the drift tube, and a method of connecting the tanks. (Author) 6 refs., 5 figs

Comparison of temperature curve and ablation zone between 915- and 2450-MHz cooled-shaft microwave antenna: Results in ex vivo porcine livers

International Nuclear Information System (INIS)

Sun Yuanyuan; Cheng Zhigang; Dong Lei; Zhang Guoming; Wang Yang; Liang Ping

2012-01-01

Objective: To compare temperature curve and ablation zone between 915- and 2450-MHz cooled-shaft microwave antenna in ex vivo porcine livers. Materials and methods: The 915- and 2450-MHz microwave ablation and thermal monitor system were used in this study. A total of 56 ablation zones and 280 temperature data were obtained in ex vivo porcine livers. The output powers were 50, 60, 70, and 80 W and the setting time was 600 s. The temperature curve of every temperature spot, the short- and long-axis diameters of the coagulation zones were recorded and measured. Results: At all four power output settings, the peak temperatures of every temperature spot had a tendency to increase accordingly as the MW output power was increased, and except for 5 mm away from the antenna, the peak temperatures for the 915 MHz cooled-shaft antenna were significantly higher than those for the 2450 MHz cooled-shaft antenna (p < 0.05). Meanwhile, the short- and long-axis diameters for the 915 MHz cooled-shaft antenna were significantly larger than those for the 2450 MHz cooled-shaft antenna (p < 0.05). Conclusion: The 915 MHz cooled-shaft antenna can yield a significantly larger ablation zone and achieve higher temperature in ablation zone than a 2450 MHz cooled-shaft antenna in ex vivo porcine livers.

A Spectroscopic Comparison of Femtosecond Laser Modified Fused Silica using kHz and MHz Laser Systems.

Energy Technology Data Exchange (ETDEWEB)

Reichman, W J; Krol, D M; Shah, L; Yoshino, F; Arai, A; Eaton, S M; Herman, P R

2005-09-29

Waveguides were written in fused silica using both a femtosecond fiber laser with a 1 MHz pulse repetition rate and a femtosecond amplified Ti:sapphire laser with a 1 kHz repetition rate. Confocal Raman and fluorescence microscopy were used to study structural changes in the waveguides written with both systems. A broad fluorescence band, centered at 650 nm, associated with non-bridging oxygen hole center (NBOHC) defects was observed after waveguide fabrication with the MHz laser. With the kHz laser system these defects were only observed for pulse energies above 1 {mu}J. Far fewer NBOHC defects were formed with the MHz laser than with kHz writing, possibly due to thermal annealing driven by heat accumulation effects at 1 MHz. When the kHz laser was used with pulse energies below 1 {mu}J, the predominant fluorescence was centered at 550 nm, a band assigned to the presence of silicon clusters (E{prime}{sub {delta}}). We also observed an increase in the intensity of the 605 cm{sup -1} Raman peak relative to the total Raman intensity, corresponding to an increase in the concentration of 3-membered rings in the lines fabricated with both laser systems.

A High Isolation MIMO Antenna without Decoupling Structure for LTE 700 MHz

Directory of Open Access Journals (Sweden)

Yanjie Wu

2015-01-01

Full Text Available This paper presents a long-term evolution (LTE 700 MHz band multiple-input-multiple-output (MIMO antenna, and high isolation between the two symmetrical antenna elements is obtained without introducing extra decoupling structure. Each antenna element is a combination antenna of PIFA and a meander monopole antenna. The end of the PIFA and the meander monopole antenna are, respectively, overlapped with the 50 Ω microstrip feed line, the two overlapping areas produce additional capacitance which can be considered decoupling structures to enhance the isolation for the MIMO antenna, as well as the impedance matching of the antenna elements. The MIMO antenna is etched on FR4 PCB board with dimensions of 71 × 40 × 1.6 mm3; the edge-to-edge separation of the two antenna elements is only nearly 0.037 λ at 700 MHz. Both simulation and measurement results are used to confirm the MIMO antenna performance; the operating bandwidth is 698–750 MHz with S11≤−6 dB and S21≤−23 dB.

Simulation of the High-Pass Filter for 56MHz Cavity for RHIC

International Nuclear Information System (INIS)

Wu, Q.; Ben-Zvi, I.

2010-01-01

The 56MHz Superconducting RF (SRF) cavity for RHIC places high demands High Order Mode (HOM) damping, as well as requiring a high field at gap with fundamental mode frequency. The damper of 56MHz cavity is designed to extract all modes to the resistance load outside, including the fundamental mode. Therefore, the circuit must incorporate a high-pass filter to reflect back the fundamental mode into the cavity. In this paper, we show the good frequency response map obtained from our filter's design. We extract a circuit diagram from the microwave elements that simulate well the frequency spectrum of the finalized filter. We also demonstrate that the power dissipation on the filter over its frequency range is small enough for cryogenic cooling.

dE/dx electronics for MARK II experiment at SLAC

International Nuclear Information System (INIS)

Bernstein, D.; Boyarski, A.; Coupal, D.; Feldman, G.; Paffrath, L.

1985-10-01

This paper describes a 100 MHz pulse digitizer for dE/dx measurements on the MARK II drift chamber at SLAC. The electronics provides the read-out of the detector's 5832 sense based on a 16-channel FASTBUS module. The basic element of the module is the TRW 6-bit Flash-ADC

Readout electronics development for the ATLAS silicon tracker

International Nuclear Information System (INIS)

Borer, K.; Beringer, J.; Anghinolfi, F.; Aspell, P.; Chilingarov, A.; Jarron, P.; Heijne, E.H.M.; Santiard, J.C.; Verweij, H.; Goessling, C.; Lisowski, B.; Reichold, A.; Bonino, R.; Clark, A.G.; Kambara, H.; La Marra, D.; Leger, A.; Wu, X.; Richeux, J.P.; Taylor, G.N.; Fedotov, M.; Kuper, E.; Velikzhanin, Yu.; Campbell, D.; Murray, P.; Seller, P.

1995-01-01

We present the status of the development of the readout electronics for the large area silicon tracker of the ATLAS experiment at the LHC, carried out by the CERN RD2 project. Our basic readout concept is to integrate a fast amplifier, analog memory, sparse data scan circuit and analog-to-digital convertor (ADC) on a single VLSI chip. This architecture will provide full analog information of charged particle hits associated unambiguously to one LHC beam crossing, which is expected to be at a frequency of 40 MHz. The expected low occupancy of the ATLAS inner silicon detectors allows us to use a low speed (5 MHz) on-chip ADC with a multiplexing scheme. The functionality of the fast amplifier and analog memory have been demonstrated with various prototype chips. Most recently we have successfully tested improved versions of the amplifier and the analog memory. A piecewise linear ADC has been fabricated and performed satisfactorily up to 5 MHz. A new chip including amplifier, analog memory, memory controller, ADC, and data buffer has been designed and submitted for fabrication and will be tested on a prototype of the ATLAS silicon tracker module with realistic electrical and mechanical constraints. (orig.)

Design and testing of a 750MHz CW-EPR digital console for small animal imaging.

Science.gov (United States)

Sato-Akaba, Hideo; Emoto, Miho C; Hirata, Hiroshi; Fujii, Hirotada G

2017-11-01

This paper describes the development of a digital console for three-dimensional (3D) continuous wave electron paramagnetic resonance (CW-EPR) imaging of a small animal to improve the signal-to-noise ratio and lower the cost of the EPR imaging system. A RF generation board, an RF acquisition board and a digital signal processing (DSP) & control board were built for the digital EPR detection. Direct sampling of the reflected RF signal from a resonator (approximately 750MHz), which contains the EPR signal, was carried out using a band-pass subsampling method. A direct automatic control system to reduce the reflection from the resonator was proposed and implemented in the digital EPR detection scheme. All DSP tasks were carried out in field programmable gate array ICs. In vivo 3D imaging of nitroxyl radicals in a mouse's head was successfully performed. Copyright © 2017 Elsevier Inc. All rights reserved.

LAMPF 201.25-MHz linac field distribution

International Nuclear Information System (INIS)

Jameson, R.A.; Halbig, J.K.

1978-01-01

Returning of the 201.25-MHz accelerator structure field distributions after the 1975 shutdown is described, and final data are given for use in beam dynamics studies. Several improvements made in procedures included a different method for stopband closure check and a positive method for postcoupler clamping. To obtain accurate results for the first tank a rigorous data reduction technique that included the removal of a ''signature'' due to the bead-pull string itself was used. Other special studies are reported, including the effects of vacuum, bead size, slug tuners, and a bead-pull method for measuring the cavity quality factor Q

Study of chemical shifts of the chloroform complexes with cyclic donors of electrons

International Nuclear Information System (INIS)

Blaszkiewicz, B.; Pajak, Z.

1973-01-01

Chemical shifts of chloroform complexes with the heterocyclic electron donors: pyridine, piperidine, alpha-picoline and gamma-picoline have been studied using the high resolution (5.10 -9 ) spectrometer operating at 80 MHz. An attempt has also been made to study the three - component solutions of : chloroform, a heterocyclic donor of electrons and carbon tetrachloride. The results, which have been obtained, indicate that the complex-forming power of pyridine and other electron donors is greater in carbon tetrachloride than in other solvents. (S.B.)

Using mobile electronic devices to deliver educational resources in developing countries.

Science.gov (United States)

Mazal, Jonathan Robert; Ludwig, Rebecca

2015-01-01

Developing countries have far fewer trained radiography professionals than developed countries, which exacerbates the limited access to imaging services. The lack of trained radiographers reflects, in part, limited availability of radiographer-specific educational resources. Historically, organizations that provided such resources in the developing world faced challenges related to the limited stock of current materials as well as expenses associated with shipping and delivery. Four mobile electronic devices (MEDs) were loaded with educational content (e-books, PDFs, and digital applications) spanning major radiography topics. The MEDs were distributed to 4 imaging departments in Ghana, India, Nepal, and Nigeria based on evidence of need for radiography-specific resources, as revealed by survey responses. A cost comparison of postal delivery vs digital delivery of educational content was performed. The effectiveness of delivering additional content via Wi-Fi transmission also was evaluated. Feedback was solicited on users' experience with the MEDs as a delivery tool for educational content. An initial average per e-book expense of $30.05, which included the cost of the device, was calculated for the MED delivery method compared with $15.56 for postal delivery of printed materials. The cost of the MED delivery method was reduced to an average of $10.05 for subsequent e-book deliveries. Additional content was successfully delivered via Wi-Fi transmission to all recipients during the 3-month follow-up period. Overall user feedback on the experience was positive, and ideas for enhancing the MED-based method were identified. Using MEDs to deliver radiography-specific educational content appears to be more cost effective than postal delivery of printed materials on a long-term basis. MEDs are more efficient for providing updates to educational materials. Customization of content to department needs, and using projector devices could enhance the usefulness of MEDs for

Success criteria for electronic medical record implementations in low-resource settings: a systematic review.

Science.gov (United States)

Fritz, Fleur; Tilahun, Binyam; Dugas, Martin

2015-03-01

Electronic medical record (EMR) systems have the potential of supporting clinical work by providing the right information at the right time to the right people and thus make efficient use of resources. This is especially important in low-resource settings where reliable data are also needed to support public health and local supporting organizations. In this systematic literature review, our objectives are to identify and collect literature about success criteria of EMR implementations in low-resource settings and to summarize them into recommendations. Our search strategy relied on PubMed queries and manual bibliography reviews. Studies were included if EMR implementations in low-resource settings were described. The extracted success criteria and measurements were summarized into 7 categories: ethical, financial, functionality, organizational, political, technical, and training. We collected 381 success criteria with 229 measurements from 47 articles out of 223 articles. Most papers were evaluations or lessons learned from African countries, published from 1999 to 2013. Almost half of the EMR systems served a specific disease area like human immunodeficiency virus (HIV). The majority of criteria that were reported dealt with the functionality, followed by organizational issues, and technical infrastructures. Sufficient training and skilled personnel were mentioned in roughly 10%. Political, ethical, and financial considerations did not play a predominant role. More evaluations based on reliable frameworks are needed. Highly reliable data handling methods, human resources and effective project management, as well as technical architecture and infrastructure are all key factors for successful EMR implementation. © The Author 2015. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

47 CFR 25.252 - Special requirements for ancillary terrestrial components operating in the 2000-2020 MHz/2180...

Science.gov (United States)

2010-10-01

..., including takeoff and landing paths. (5) Exceed an aggregate power flux density of −51.8 dBW/m2 in a 1.23 MHz bandwidth at all airport runways and aircraft stand areas, including takeoff and landing paths and...) Be located less than 820 meters from a U.S. Earth Station facility operating in the 2200-2290 MHz...

Pulling the trigger on LHC electronics

CERN Document Server

CERN. Geneva

2001-01-01

The conditions at CERN's Large Hadron Collider pose severe challenges for the designers and builders of front-end, trigger and data acquisition electronics. A recent workshop reviewed the encouraging progress so far and discussed what remains to be done. The LHC experiments have addressed level one trigger systems with a variety of high-speed hardware. The CMS Calorimeter Level One Regional Trigger uses 160 MHz logic boards plugged into the front and back of a custom backplane, which provides point-to-point links between the cards. Much of the processing in this system is performed by five types of 160 MHz digital applications-specific integrated circuits designed using Vitesse submicron high-integration gallium arsenide gate array technology. The LHC experiments make extensive use of field programmable gate arrays (FPGAs). These offer programmable reconfigurable logic, which has the flexibility that trigger designers need to be able to alter algorithms so that they can follow the physics and detector perform...

PHERMEX electron gun development

International Nuclear Information System (INIS)

Builta, L.A.; Elliott, J.C.; Moir, D.C.; Starke, T.P.; Vecere, C.A.

1983-01-01

The PHERMEX facility is a 50-MHz standing-wave linear accelerator. Electrons are injected, accelerated, and transported to a tungsten target where bremsstrahlung x rays are generated for flash radiography of hydrodynamic systems. The purpose of this article is to describe the progress of PHERMEX electron gun development. The goal of this program is to generate and transport a 200-ns, 1-MV, 1-kA electron beam into the first PHERMEX accelerating cavity. The standard gun is operated at a pulse voltage of 550 kV, which is the limit determined by internal breakdown of the vacuum insulator. This insulator has been redesigned, and the gun has been pulsed at 750 kV without internal breakdown. At present, the current output is not limited by voltage but by a phenomenon called pulse shortening, which occurs at a pulse voltage of approximately 650 kV. The phenomenon has been investigated and the results are presented

The PS 13.3-20 MHZ RF Systems for LHC

CERN Document Server

Garoby, R; Haase, M; Krusche, A; Maesen, P; Morvillo, M; Paoluzzi, M; Rossi, C

2003-01-01

As part of the preparation of the PS as an injector for the LHC, a prototype 20 MHz rf system has been used, to demonstrate that the nominal longitudinal performance of the proton beam for LHC can be obtained using multiple bunch-splittings. Based on these successful results obtained during 2000, the development of the operational rf system began in 2001. To allow the preparation of bunch trains with a bunch spacing of 25 or 75 ns, this system must operate either at 20 or 13.3 MHz respectively. Two new ferrite cavities and their associated amplifiers have been designed and built. Each one can provide a maximum voltage of 20 kV peak during 200 ms with a 10% duty cycle. The cavities are equipped with fast (~20 ms) gap shorting relays, and rf feedback reduces their Q below 10 at both frequencies. A single system is sufficient to generate the nominal beam for LHC. The second one will then be both a "hot spare" and a very valuable performance enhancement providing the possibility of handling a larger than nominal ...

High-power fiber lasers for photocathode electron injectors

Directory of Open Access Journals (Sweden)

Zhi Zhao

2014-05-01

Full Text Available Many new applications for electron accelerators require high-brightness, high-average power beams, and most rely on photocathode-based electron injectors as a source of electrons. To achieve such a photoinjector, one requires both a high-power laser system to produce the high average current beam, and also a system at reduced repetition rate for electron beam diagnostics to verify high beam brightness. Here we report on two fiber laser systems designed to meet these specific needs, at 50 MHz and 1.3 GHz repetition rate, together with pulse pickers, second harmonic generation, spatiotemporal beam shaping, intensity feedback, and laser beam transport. The performance and flexibility of these laser systems have allowed us to demonstrate electron beam with both low emittance and high average current for the Cornell energy recovery linac.

47 CFR 95.1119 - Specific requirements for wireless medical telemetry devices operating in the 608-614 MHz band.

Science.gov (United States)

2010-10-01

... devices operating in the 608-614 MHz band. For a wireless medical telemetry device operating within the... 47 Telecommunication 5 2010-10-01 2010-10-01 false Specific requirements for wireless medical telemetry devices operating in the 608-614 MHz band. 95.1119 Section 95.1119 Telecommunication FEDERAL...

Status of the mechanical design of the 650 MHz cavities for Project X

Energy Technology Data Exchange (ETDEWEB)

Barbanotti, S.; Grimm, C.; Champion, M.; Foley, M.; Ginsburg, C.M.; Gonin, I.; Peterson, T.; Ristori, L.; Yakovlev, V.; /Fermilab

2011-03-01

In the high-energy section of the Project X Linac, acceleration of H{sup -} ions takes place in superconducting cavities operating at 650 MHz. Two families of five-cell elliptical cavities are planned: beta = 0.61 and beta = 0.9. A specific feature of the Project X Linac is low beam loading, and thus, low bandwidth and higher sensitivity to microphonics. Efforts to optimize the mechanical design of the cavities to improve their mechanical stability in response to the helium bath pressure fluctuations will be presented. These efforts take into account constraints such as cost and ease of fabrication. Also discussed will be the overall design status of the cavities and their helium jackets. The proposed design of the 3 GeV Project X superconducting (SC) Linac employs 650 MHz five-cell elliptical cavities to accelerate 1.0 mA of average H-beam current in the 160-3000 MeV energy range. The 650 MHz region of the Linac is divided into two sections with two different geometric phase velocity factors: beta = 0.61 to cover the 160-520 MeV range and beta = 0.9 to cover the 520-3000 MeV range. Approximately 40 beta = 0.61 and 150 beta = 0.9 cavities are currently planned for the project. An R&D program is in progress at FNAL, in collaboration with TJNAF and India, to develop the 650 MHz cavities for the proposed Linac design. This R&D program includes the design and fabrication of several beta = 0.61 and beta = 0.9 single-cell prototypes for evaluation prior to production of the five-cell cavities. FNAL has contracted AES to fabricate the beta = 0.9 prototypes, while TJNAF is building beta = 0.61 prototypes of their own design. In the remainder of this paper we will restrict our discussion to the five-cell beta = 0.9 cavities.

Macular hole: 10 and 20-MHz ultrasound and spectral-domain optical coherence tomography

Directory of Open Access Journals (Sweden)

Juliana Mantovani Bottós

2012-12-01

Full Text Available PURPOSE: Optical coherence tomography (OCT is valuable for macula evaluation. However, as this technique relies on light energy it cannot be performed in the presence of opaque media. In such cases, the ultrasound (US may predict some macular features. The aim of this study was to characterize images obtained by ultrasound with 10 and 20-MHz transducers comparing to OCT, as well as to analyze the relationship between the vitreous and retina in eyes with macular hole (MH. METHODS: 29 eyes of 22 patients with biomicroscopic evidence of MH at different stages were included. All patients were evaluated using ultrasonography with 10 and 20-MHz transducers and OCT. RESULTS: OCT identified signs of MH in 25 of 29 eyes. The remaining 4 cases not identified by US were pseudoholes caused by epiretinal membranes. In MH stages I (2 eyes and II (1 eye, both transducers were not useful to analyze the macular thickening, but suggestive findings as macular irregularity, operculum or partial posterior vitreous detachment (PVD were highlighted. In stages III (14 eyes and IV (5 eyes, both transducers identified the double hump irregularity and thickening. US could measure the macular thickness and other suggestive findings for MH: operculum, vitreomacular traction and partial or complete PVD. In cases of pseudoholes, US identified irregularities macular contour and a discrete depression. CONCLUSION: 10-MHz US was useful for an overall assessment of the vitreous body as well as its relationship to the retina. The 20-MHz transducer allowed valuable information on the vitreomacular interface and macular contour. OCT provides superior quality for fine morphological study of macular area, except in cases of opaque media. In these cases, and even if OCT is not available, the combined US study is able to provide a valid evaluation of the macular area improving therapeutic approach.

47 CFR 22.603 - 488-494 MHz fixed service in Hawaii.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false 488-494 MHz fixed service in Hawaii. 22.603 Section 22.603 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES... fixed service in Hawaii. Before filing applications for authorization of inter-island control and/or...

The influence of the reflective environment on the absorption of a human male exposed to representative base station antennas from 300 MHz to 5 GHz.

Science.gov (United States)

Vermeeren, G; Gosselin, M C; Kühn, S; Kellerman, V; Hadjem, A; Gati, A; Joseph, W; Wiart, J; Meyer, F; Kuster, N; Martens, L

2010-09-21

The environment is an important parameter when evaluating the exposure to radio-frequency electromagnetic fields. This study investigates numerically the variation on the whole-body and peak spatially averaged-specific absorption rate (SAR) in the heterogeneous virtual family male placed in front of a base station antenna in a reflective environment. The SAR values in a reflective environment are also compared to the values obtained when no environment is present (free space). The virtual family male has been placed at four distances (30 cm, 1 m, 3 m and 10 m) in front of six base station antennas (operating at 300 MHz, 450 MHz, 900 MHz, 2.1 GHz, 3.5 GHz and 5.0 GHz, respectively) and in three reflective environments (a perfectly conducting wall, a perfectly conducting ground and a perfectly conducting ground + wall). A total of 72 configurations are examined. The absorption in the heterogeneous body model is determined using the 3D electromagnetic (EM) finite-difference time-domain (FDTD) solver Semcad-X. For the larger simulations, requirements in terms of computer resources are reduced by using a generalized Huygens' box approach. It has been observed that the ratio of the SAR in the virtual family male in a reflective environment and the SAR in the virtual family male in the free-space environment ranged from -8.7 dB up to 8.0 dB. A worst-case reflective environment could not be determined. ICNIRP reference levels not always showed to be compliant with the basic restrictions.

The influence of the reflective environment on the absorption of a human male exposed to representative base station antennas from 300 MHz to 5 GHz

International Nuclear Information System (INIS)

Vermeeren, G; Joseph, W; Martens, L; Gosselin, M C; Kuehn, S; Kuster, N; Kellerman, V; Meyer, F; Hadjem, A; Gati, A; Wiart, J

2010-01-01

The environment is an important parameter when evaluating the exposure to radio-frequency electromagnetic fields. This study investigates numerically the variation on the whole-body and peak spatially averaged-specific absorption rate (SAR) in the heterogeneous virtual family male placed in front of a base station antenna in a reflective environment. The SAR values in a reflective environment are also compared to the values obtained when no environment is present (free space). The virtual family male has been placed at four distances (30 cm, 1 m, 3 m and 10 m) in front of six base station antennas (operating at 300 MHz, 450 MHz, 900 MHz, 2.1 GHz, 3.5 GHz and 5.0 GHz, respectively) and in three reflective environments (a perfectly conducting wall, a perfectly conducting ground and a perfectly conducting ground + wall). A total of 72 configurations are examined. The absorption in the heterogeneous body model is determined using the 3D electromagnetic (EM) finite-difference time-domain (FDTD) solver Semcad-X. For the larger simulations, requirements in terms of computer resources are reduced by using a generalized Huygens' box approach. It has been observed that the ratio of the SAR in the virtual family male in a reflective environment and the SAR in the virtual family male in the free-space environment ranged from -8.7 dB up to 8.0 dB. A worst-case reflective environment could not be determined. ICNIRP reference levels not always showed to be compliant with the basic restrictions.

The influence of the reflective environment on the absorption of a human male exposed to representative base station antennas from 300 MHz to 5 GHz

Energy Technology Data Exchange (ETDEWEB)

Vermeeren, G; Joseph, W; Martens, L [Ghent University-INTEC/IBBT, Gaston Crommenlaan 8 box 201, B-9050 Ghent (Belgium); Gosselin, M C; Kuehn, S; Kuster, N [IT' IS Foundation, Zurich (Switzerland); Kellerman, V; Meyer, F [EMSS, Stellenbosch (South Africa); Hadjem, A; Gati, A; Wiart, J, E-mail: Gunter.Vermeeren@intec.UGent.b [Orange Labs, Paris (France)

2010-09-21

The environment is an important parameter when evaluating the exposure to radio-frequency electromagnetic fields. This study investigates numerically the variation on the whole-body and peak spatially averaged-specific absorption rate (SAR) in the heterogeneous virtual family male placed in front of a base station antenna in a reflective environment. The SAR values in a reflective environment are also compared to the values obtained when no environment is present (free space). The virtual family male has been placed at four distances (30 cm, 1 m, 3 m and 10 m) in front of six base station antennas (operating at 300 MHz, 450 MHz, 900 MHz, 2.1 GHz, 3.5 GHz and 5.0 GHz, respectively) and in three reflective environments (a perfectly conducting wall, a perfectly conducting ground and a perfectly conducting ground + wall). A total of 72 configurations are examined. The absorption in the heterogeneous body model is determined using the 3D electromagnetic (EM) finite-difference time-domain (FDTD) solver Semcad-X. For the larger simulations, requirements in terms of computer resources are reduced by using a generalized Huygens' box approach. It has been observed that the ratio of the SAR in the virtual family male in a reflective environment and the SAR in the virtual family male in the free-space environment ranged from -8.7 dB up to 8.0 dB. A worst-case reflective environment could not be determined. ICNIRP reference levels not always showed to be compliant with the basic restrictions.

FPGA based phase detection technique for electron density measurement in SST-1 tokamak

International Nuclear Information System (INIS)

Pramila; Mandaliya, Hitesh; Rajpal, Rachana; Kaur, Rajwinder

2016-01-01

A multi-channel signal-conditioning and phase-detection concept is implemented in the prototype design using the high-precision OPAMP, high-speed comparators, high Q filters, high-density FPGA (Field Programmable Gate array), 10 MHz parallel-multiplying DACs (Digital to Analog Converter), etc. The complete digital-logic for the phase-detection is implemented inside the logic cells of FPGA using VHDL code, with high speed 100 MHz clock generated from Digital Clock Manager (DCM), which is used to measure the time elapsed between zero crossings of the two signals coming from reference and probe paths of the diagnostics. The logic is implemented to measure either leading or lagging phase and also to accumulate the total phase difference throughout the shot duration with the maximum value of accumulated phase of 5760 (16 cycles × 360°) degree and a resolution of 3.6 °. A precision high speed and high bandwidth (80 MHz) operational amplifiers are used as the front end-electronics component for conditioning the high-frequency (1 MHz) and low amplitude signal (μV). The hardware detail, implementation concept in FPGA and testing results will be presented in the paper.

FPGA based phase detection technique for electron density measurement in SST-1 tokamak

Energy Technology Data Exchange (ETDEWEB)

Pramila, E-mail: pramila@ipr.res.in; Mandaliya, Hitesh; Rajpal, Rachana; Kaur, Rajwinder

2016-11-15

A multi-channel signal-conditioning and phase-detection concept is implemented in the prototype design using the high-precision OPAMP, high-speed comparators, high Q filters, high-density FPGA (Field Programmable Gate array), 10 MHz parallel-multiplying DACs (Digital to Analog Converter), etc. The complete digital-logic for the phase-detection is implemented inside the logic cells of FPGA using VHDL code, with high speed 100 MHz clock generated from Digital Clock Manager (DCM), which is used to measure the time elapsed between zero crossings of the two signals coming from reference and probe paths of the diagnostics. The logic is implemented to measure either leading or lagging phase and also to accumulate the total phase difference throughout the shot duration with the maximum value of accumulated phase of 5760 (16 cycles × 360°) degree and a resolution of 3.6 °. A precision high speed and high bandwidth (80 MHz) operational amplifiers are used as the front end-electronics component for conditioning the high-frequency (1 MHz) and low amplitude signal (μV). The hardware detail, implementation concept in FPGA and testing results will be presented in the paper.

Modular 125 ps resolution time interval digitizer for 10 MHz stop burst rates and 33 ms range

International Nuclear Information System (INIS)

Turko, B.

1978-01-01

A high resolution multiple stop time interval digitizer is described. It is capable of resolving stop burst rates of up to 10 MHz with an incremental resolution of 125 ps within a range of 33 ms. The digitizer consists of five CAMAC modules and uses a standard CAMAC crate and controller. All the functions and ranges are completely computer controlled. Any two subsequent stop pulses in a burst can be resolved within 100 ns due to a new dual interpolation technique employed. The accuracy is maintained by a high stability 125 MHz reference clock. Up to 131 stop events can be stored in a 48-bit, 10 MHz derandomizing storage register before the digitizer overflows. The experimental data are also given

Sustaining GHz oscillation of carbon nanotube based oscillators via a MHz frequency excitation

International Nuclear Information System (INIS)

Motevalli, Benyamin; Taherifar, Neda; Liu, Jefferson Zhe

2016-01-01

There have been intensive studies to investigate the properties of gigahertz nano-oscillators based on multi-walled carbon nanotubes (MWCNTs). Many of these studies, however, revealed that the unique telescopic translational oscillations in such devices would damp quickly due to various energy dissipation mechanisms. This challenge remains the primary obstacle against its practical applications. Herein, we propose a design concept in which a GHz oscillation could be re-excited by a MHz mechanical motion. This design involves a triple-walled CNT, in which sliding of the longer inner tube at a MHz frequency can re-excite and sustain a GHz oscillation of the shorter middle tube. Our molecular dynamics (MD) simulations prove this design concept at ∼10 nm scale. A mathematical model is developed to explore the feasibility at a larger size scale. As an example, in an oscillatory system with the CNT’s length above 100 nm, the high oscillatory frequency range of 1.8–3.3 GHz could be excited by moving the inner tube at a much lower frequency of 53.4 MHz. This design concept together with the mechanical model could energize the development of GHz nano-oscillators in miniaturized electro-mechanical devices. (paper)

Testing of self-triggered nXYTER electronics for integrating with GEM detector for high frequency operation

International Nuclear Information System (INIS)

Saini, J.; Dubey, A.K.; Chattopadhyay, S.; Singaraju, R.N.

2013-01-01

A GEM-based tracking system is planned to be used for muon tracking in the proposed CBM experiment at FAIR. The peak hit density in the central region of the chamber is expected to reach 1 MHz/cm 2 . For a detector to be operational at high intensity (upto MHz), it is useful to know the compatibility of the readout electronics with the detector. At very high rates and sufficiently large signal amplitude, there is a possibility of preamplifier saturation resulting in zero or distorted amplitude of the output signal

300-MHz optical discriminator-counter

International Nuclear Information System (INIS)

Turko, B.; Lo, C.C.

1981-07-01

The prediction of future CO 2 content in the atmosphere is not completely credible because the oceanographers and terrestrial ecologists do not agree on the global CO 2 balance. Very precise measurements of O 2 /N 2 ratio using Raman scattering over a few years' period could provide important information and lead to the explanation of the disparity in the atmospheric CO 2 balance. An optical discriminator-counter has been developed to count closely spaced optical events in the few photon level. Simulated optical events as close as 2.5 ns apart had been positively detected by using selected photomultipliers and optimized discriminators. Testing of the optical discriminator-counter was done by using an electrical pulse pair spaced 3 ns apart and also by a similar optical pulse pair generated by fast light-emitting diode. The photomultiplier is capable of counting an average single photoelectron pulse frequency of 50 MHz and has a sensitive detecting area of 50 mm in diameter. The discriminator performance is discussed

Potential of Sub-GHz Wireless for Future IoT Wearables and Design of Compact 915 MHz Antenna

Directory of Open Access Journals (Sweden)

Adolfo Di Serio

2017-12-01

Full Text Available Internet of Things (IoT technology is rapidly emerging in medical applications as it offers the possibility of lower-cost personalized healthcare monitoring. At the present time, the 2.45 GHz band is in widespread use for these applications but in this paper, the authors investigate the potential of the 915 MHz ISM band in implementing future, wearable IoT devices. The target sensor is a wrist-worn wireless heart rate and arterial oxygen saturation (SpO2 monitor with the goal of providing efficient wireless functionality and long battery lifetime using a commercial Sub-GHz low-power radio transceiver. A detailed analysis of current consumption for various wireless protocols is also presented and analyzed. A novel 915 MHz antenna design of compact size is reported that has good resilience to detuning by the human body. The antenna also incorporates a matching network to meet the challenging bandwidth requirements and is fabricated using standard, low-cost FR-4 material. Full-Wave EM simulations are presented for the antenna placed in both free-space and on-body cases. A prototype antenna is demonstrated and has dimensions of 44 mm × 28 mm × 1.6 mm. The measured results at 915 MHz show a 10 dB return loss bandwidth of 55 MHz, a peak realized gain of − 2.37 dBi in free-space and − 6.1 dBi on-body. The paper concludes by highlighting the potential benefits of 915 MHz operation for future IoT devices.

Potential of Sub-GHz Wireless for Future IoT Wearables and Design of Compact 915 MHz Antenna.

Science.gov (United States)

Di Serio, Adolfo; Buckley, John; Barton, John; Newberry, Robert; Rodencal, Matthew; Dunlop, Gary; O'Flynn, Brendan

2017-12-22

Internet of Things (IoT) technology is rapidly emerging in medical applications as it offers the possibility of lower-cost personalized healthcare monitoring. At the present time, the 2.45 GHz band is in widespread use for these applications but in this paper, the authors investigate the potential of the 915 MHz ISM band in implementing future, wearable IoT devices. The target sensor is a wrist-worn wireless heart rate and arterial oxygen saturation (SpO2) monitor with the goal of providing efficient wireless functionality and long battery lifetime using a commercial Sub-GHz low-power radio transceiver. A detailed analysis of current consumption for various wireless protocols is also presented and analyzed. A novel 915 MHz antenna design of compact size is reported that has good resilience to detuning by the human body. The antenna also incorporates a matching network to meet the challenging bandwidth requirements and is fabricated using standard, low-cost FR-4 material. Full-Wave EM simulations are presented for the antenna placed in both free-space and on-body cases. A prototype antenna is demonstrated and has dimensions of 44 mm × 28 mm × 1.6 mm. The measured results at 915 MHz show a 10 dB return loss bandwidth of 55 MHz, a peak realized gain of - 2.37 dBi in free-space and - 6.1 dBi on-body. The paper concludes by highlighting the potential benefits of 915 MHz operation for future IoT devices.

47 CFR 25.254 - Special requirements for ancillary terrestrial components operating in the 1610-1626.5 MHz/2483.5...

Science.gov (United States)

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Special requirements for ancillary terrestrial components operating in the 1610-1626.5 MHz/2483.5-2500 MHz bands. 25.254 Section 25.254 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Technical...

Polarization observations of four southern pulsars at 1560 MHz

Science.gov (United States)

Wu, Xin-Ji; Manchester, R. N.; Lyne, A. G.

1991-12-01

Some interesting results from the mean pulse polarization observations of four southern pulsars made at the Australian National Radio Astronomy Observatory, Parkes, using the 64-m telescope in June and July, 1988, are presented. The 2 x 16 x 5 MHz filter system from Jodrell Bank has proved excellent in dedispersing the pulse signals and measuring their polarization properties. Data for the four pulsars are given in some detail, and their spectral behavior is discussed.

1800MHz Microwave Induces p53 and p53-Mediated Caspase-3 Activation Leading to Cell Apoptosis In Vitro.

Directory of Open Access Journals (Sweden)

Fuqiang Xing

Full Text Available Recent studies have reported that exposure of mammalian cells to microwave radiation may have adverse effects such as induction of cell apoptosis. However, the molecular mechanisms underlying microwave induced mammalian cell apoptosis are not fully understood. Here, we report a novel mechanism: exposure to 1800MHz microwave radiation induces p53-dependent cell apoptosis through cytochrome c-mediated caspase-3 activation pathway. We first measured intensity of microwave radiation from several electronic devices with an irradiation detector. Mouse NIH/3T3 and human U-87 MG cells were then used as receivers of 1800MHz electromagnetic radiation (EMR at a power density of 1209 mW/m2. Following EMR exposure, cells were analyzed for viability, intracellular reactive oxygen species (ROS generation, DNA damage, p53 expression, and caspase-3 activity. Our analysis revealed that EMR exposure significantly decreased viability of NIH/3T3 and U-87 MG cells, and increased caspase-3 activity. ROS burst was observed at 6 h and 48 h in NIH/3T3 cells, while at 3 h in U-87 MG cells. Hoechst 33258 staining and in situ TUNEL assay detected that EMR exposure increased DNA damage, which was significantly restrained in the presence of N-acetyl-L-cysteine (NAC, an antioxidant. Moreover, EMR exposure increased the levels of p53 protein and p53 target gene expression, promoted cytochrome c release from mitochondrion, and increased caspase-3 activity. These events were inhibited by pretreatment with NAC, pifithrin-α (a p53 inhibitor and caspase inhibitor. Collectively, our findings demonstrate, for the first time, that 1800MHz EMR induces apoptosis-related events such as ROS burst and more oxidative DNA damage, which in turn promote p53-dependent caspase-3 activation through release of cytochrome c from mitochondrion. These findings thus provide new insights into physiological mechanisms underlying microwave-induced cell apoptosis.

Anomalous length of electron bunches as an instability threshold

International Nuclear Information System (INIS)

Messerschmid, E.; Month, M.

1976-01-01

A mechanism for the anomalous length of electron bunches, based on the existence of a ''fast'' longitudinal instability, is proposed. The equilibrium length is obtained by requiring that the growth rate be sufficiently larger than the rate of synchrotron oscillations. The theory is used to describe the bunch length data for SPEAR at 1.5 GeV. The low voltage and/or high current regime is dominated by a set of ''low'' frequency, low Q resonators [e.g., f = 320 MHz, Δf(fwhm) = 130 MHz]. To fit the observations in the high voltage and/or low current regime, a high frequency, low Q impedance is required (e.g., f = 3.8 GHz, Δf = 1.0 GHz). The mechanism is mediated by the resistive component of the impedance. Thus, there is qualitative agreement with the observed distortion of the bunch tail. This is in contrast to the predictions of the potential well models based on a reactive impedance source. These latter theories yield large distortions of the head of the bunch. The calculated power dissipated in the assumed sources by the given electron bunch is not inconsistent with estimates made for SPEAR

Simulation of the influence high-frequency (2 MHz) capacitive gas discharge and magnetic field on the plasma sheath near a surface in hypersonic gas flow

International Nuclear Information System (INIS)

Schweigert, I. V.

2012-01-01

The plasma sheath near the surface of a hypersonic aircraft formed under associative ionization behind the shock front shields the transmission and reception of radio signals. Using two-dimensional kinetic particle-in-cell simulations, we consider the change in plasma-sheath parameters near a flat surface in a hypersonic flow under the action of electrical and magnetic fields. The combined action of a high-frequency 2-MHz capacitive discharge, a constant voltage, and a magnetic field on the plasma sheath allows the local electron density to be reduced manyfold.

Two-dimensional 220 MHz Fourier transform EPR imaging

International Nuclear Information System (INIS)

Placidi, Giuseppe; Brivati, John A.; Alecci, Marcello; Testa, Luca; Sotgiu, Antonello

1998-01-01

In the last decade radiofrequency continuous-wave EPR spectrometers have been developed to detect and localize free radicals in vivo. Only recently, pulsed radiofrequency EPR spectrometers have been described for imaging applications with small samples. In the present work, we show the first two-dimensional image obtained at 220 MHz on a large phantom (40 ml) that simulates typical conditions of in vivo EPR imaging. This pulsed EPR apparatus has the potential to make the time required for three-dimensional imaging compatible with the biological half-life of normally used paramagnetic probes. (author)

The all-sky 408 MHz survey

International Nuclear Information System (INIS)

Haslam, C.G.T.; Salter, C.J.; Stoffel, H.

1981-01-01

A brief outline of the results of this survey is presented. The 408 MHz All-sky Survey has been made from four radio continuum surveys observed between 1965 and 1978, using the Jodrell Bank MKI telescope (Haslam et al., 1970), the Effelsberg 100 metre telescope (Haslam et al., 1974) and the Parkes 64 metre telescope (Haslam et al., 1975). A detailed description of the survey data reduction and calibration methods, with preliminary astronomical results will soon be published (Haslam et al., 1980a) and a second paper will give an atlas of maps at the full survey resolution of 51' arc between half power points (Haslam et al., 1980b). A map, smoothed to a gaussian beam with resolution between half power poitns of 3 0 , is presented. (Auth.)

Interferometer observations of quasars from the Jodrell Bank 966-MHz survey

International Nuclear Information System (INIS)

Owen, F.N.; Porcas, R.W.; Neff, S.G.

1978-01-01

Radio observations are reported of the 68 quasars with blue magnitudes < or =19.0 identified in the Jodrell Bank 966-MHz survey. The observations were made with the Green Bank interferometer at 2695 MHz with baselines ranging from 300 m to 35 km. Model brightness distributions are presented consisting of one to four elliptical Gaussian components. A limiting resolution of 0.1 arcsec was obtained in the best cases. For radio sources with steep spectra, angular sizes ranged from <0.2 to 85 arcsec. Only two of the sources with steep radio spectra were unresolved. The median angular size for the entire sample is 8 arcsec. For quasars larger than 10 arcsec, the structures can almost always be described in triple. Twenty-nine of the 30 such sources have outer lobes on either side of the optical source and 24 of the 30 have detectable central components. The ratio of the flux densities of the outer lobes varies over a wide range but has a median value of 1.8. The ratio of the flux density of the central component to the total flux density at 2695 MHz ranges from 1% to 95%, with a median value near 10%. The existence of triple structure in the vast majority of quasars, along the with failure to detect central components in blank field sources, suggests a close connection between the nuclear activity in the radio and optical regions of the spectrum. It is also consistent with a picture in which the difference between blank fields and quasars is just transient activity in the nucleus of a distant parent galaxy

Electronic Human Resources Management (e-HRM Adoption Studies: Past and Future Research

Directory of Open Access Journals (Sweden)

Winarto Winarto

2018-05-01

Full Text Available Electronic human resource management (e-HRM systems become more widely used by profit and non-profit organization. However, the field currently lacks sound theoretical frameworks that can be useful in addressing a key issue concerning the implementation of e-HRM systems, in particular to obtain a better understanding of the factors influencing the adoption of e-HRM systems. The objective of this paper is to provide a foundation towards the development of a theoretical framework for the implementation of e-HRM systems and develop a conceptual model that would reflect the nature of e-HRM systems’ adoption through systematic literature review. Adopting Crossan and Apaydin’s procedure of systematic review, this paper investigated 21 empirical papers of electronics human resources management, then categorized them into 4 characteristics which influence the adoption; System and technology characteristics; Organizational characteristics; User/individual characteristics, and Environmental and contextual characteristics. Finally, the e-HRM adoption research framework is drawn and based on the framework; avenues for future research are discussed.   Bahasa Indonesia Abstrak: Manajemen sumber daya manusia elektronik (selanjutnya disebut dengan e-HRM semakin banyak digunakan oleh organisasi profit dan nonprofit. Namun, bidang dan topik ini belum memiliki kerangka teori yang mapan, yang dapat digunakan untuk menganalisis isu-isu terkait penerapan e-HRM, terutama mengenai faktor-faktor yang mempengaruhi adopsi sistem e-HRM. Tujuan penelitian ini adalah untuk memberikan landasan bagi pengembangan kerangka teoritis untuk implementasi sistem e-HRM dan mengembangkan model konseptual yang akan menggambarkan adopsi sistem e-HRM melalui tinjauan literatur sistematis. Mengadopsi prosedur dan metode Crossan dan Apaydin untuk melakukan telaah literatur secara sistematis, paper ini menyelidiki 21 publikasi empiris manajemen sumber daya manusia elektronik dari 2

A 500-600 MHz GaN power amplifier with RC-LC stability network

Science.gov (United States)

Ma, Xinyu; Duan, Baoxing; Yang, Yintang

2017-08-01

A 500-600 MHz high-efficiency, high-power GaN power amplifier is designed and realized on the basis of the push-pull structure. The RC-LC stability network is proposed and applied to the power amplifier circuit for the first time. The RC-LC stability network can significantly reduce the high gain out the band, which eliminates the instability of the power amplifier circuit. The developed power amplifier exhibits 58.5 dBm (700 W) output power with a 17 dB gain and 85% PAE at 500-600 MHz, 300 μs, 20% duty cycle. It has the highest PAE in P-band among the products at home and abroad. Project supported by the National Key Basic Research Program of China (No. 2014CB339901).

A high dynamic range programmable CMOS front-end filter with a tuning range from 1850 to 2400 MHz

DEFF Research Database (Denmark)

Christensen, Kåre Tais; Lee, Thomas H.; Bruun, Erik

2005-01-01

This paper presents a highly programmable front-end filter and amplifier intended to replace SAW filters and low noise amplifiers (LNA) in multi-mode direct conversion radio receivers. The filter has a 42 MHz bandwidth, is tunable from 1850 to 2400 MHz, achieves a 5.8 dB NF, -25 dBm in-band 1-d...

Detection of trace microcystin-LR on a 20 MHz QCM sensor coated with in situ self-assembled MIPs.

Science.gov (United States)

He, Hao; Zhou, Lianqun; Wang, Yi; Li, Chuanyu; Yao, Jia; Zhang, Wei; Zhang, Qingwen; Li, Mingyu; Li, Haiwen; Dong, Wen-fei

2015-01-01

A 20 MHz quartz crystal microbalance (QCM) sensor coated with in situ self-assembled molecularly imprinted polymers (MIPs) was presented for the detection of trace microcystin-LR (MC-LR) in drinking water. The sensor performance obtained using the in situ self-assembled MIPs was compared with traditionally synthesized MIPs on 20 MHz and normal 10 MHz QCM chip. The results show that the response increases by more than 60% when using the in situ self-assembly method compared using the traditionally method while the 20 MHz QCM chip provides four-fold higher response than the 10 MHz one. Therefore, the in situ self-assembled MIPs coated on a high frequency QCM chip was used in the sensor performance test to detect MC-LR in tap water. It showed a limit of detection (LOD) of 0.04 nM which is lower than the safety guideline level (1 nM MC-LR) of drinking water in China. The low sensor response to other analogs indicated the high specificity of the sensor to MC-LR. The sensor showed high stability and low signal variation less than 2.58% after regeneration. The lake water sample analysis shows the sensor is possible for practical use. The combination of the higher frequency QCM with the in situ self-assembled MIPs provides a good candidate for the detection of other small molecules. Copyright © 2014 Elsevier B.V. All rights reserved.

Electromagnetic Compatibility Studies: LTE BS vs. Aeronautical Radionavigation Services in 694-790 MHz Frequency Band

Directory of Open Access Journals (Sweden)

Stankevičius Evaldas

2014-10-01

Full Text Available This paper presents the sharing analysis of the 694–790 MHz frequency band for Mobile services IMT and Aeronautical radio-navigation services (ARNS using SEAMCAT (established by CEPT software based on the statistical simulation (Monte-Carlo method. In 2012 the World Radiocommunication Conference (WRC-12 decided to allocate the 694–790 MHz frequency band (the so-called 700 MHz band to mobile services IMT (excluding aeronautical mobile after WRC-15 conference. But this agreement raises electromagnetic compatibility problems, which should be solved until WRC-15 [1]. This study was carried out in two phases: first applying theoretical analysis, then statistical Monte-Carlo simulations with SEAMCAT software tool in order to verify results obtained in theoretical approach. Analytical calculations shows that the required protection distances between ARNS stations and the MS base stations are 132 km. The obtained results from SEAMCAT simulations indicate that separation distance should be above 100 km. These results illustrate that the systems are not electromagnetically compatible. The possible mitigation technic could be antenna pattern correction.

47 CFR 90.267 - Assignment and use of frequencies in the 450-470 MHz band for low power use.

Science.gov (United States)

2010-10-01

...-470 MHz band for low power use. 90.267 Section 90.267 Telecommunication FEDERAL COMMUNICATIONS... Special Frequencies or Frequency Bands § 90.267 Assignment and use of frequencies in the 450-470 MHz band... medical radio telemetry device with an output power not to exceed 20 milliwatts without specific...

A High Current Proton Linac with 352 MHz SC Cavities

CERN Document Server

Pagani, C; Pierini, P

1996-01-01

A proposal for a 10-120 mA proton linac employing superconducting beta-graded, CERN type, four cell cavities at 352 MHz is presented. The high energy part (100 MeV-1 GeV) of the machine is split in three beta-graded sections, and transverse focusing is provided via a periodic doublet array. All the parameters, like power in the couplers and accelerating fields in the cavities, are within the state of the art, achieved in operating machines. A first stage of operation at 30 mA beam current is proposed, while the upgrade of the machine to 120 mA operation can be obtained increasing the number of klystrons and couplers per cavity. The additional coupler ports, up to four, will be integrated in the cavity design. Preliminary calculations indicate that beam transport is feasible, given the wide aperture of the 352 MHz structures. A capital cost of less than 100 M$ at 10 mA, reaching up to 280 M$ for the 120 mA extension, has been estimated for the superconducting high energy section (100 MeV-1 GeV). The high effic...

Characterization of the SPS 800MHz travelling wave cavities.

CERN Document Server

Bazyl, Dmitry

2015-01-01

It is well known that HOMs in RF cavities are a potentially dangerous source of beam impedance. Therefore, HOMs (both longitudinal and transverse) can drive the beam unstable . The 800MHz cavities of the SPS were studied in the past. However, very little documentation was left behind. Currently, the performance of the SPS is limited by a longitudinal beam instability. In order to study this instability, an accurate impedance model of the whole SPS is needed.

Upgrading the ATLAS Tile Calorimeter Electronics

CERN Document Server

Popeneciu, G; The ATLAS collaboration

2014-01-01

The Tile Calorimeter (TileCal) is the central hadronic calorimeter of the ATLAS experiment at LHC. Around 2023, after the upgrade of the LHC (High Luminosity LHC, phase 2) the peak luminosity will increase by a factor of 5 compared to the design value (1034 cm-2 s-1), thus requiring an upgrade of the TileCal readout electronics. Except the 9852 photomultipliers (PMTs), most of the on- and off-detector electronics will be replaced, with the aim of digitizing all PMT pulses at 40 MHz at the front-end level and sending them with 10 Gbps optical links to the back-end electronics. Moreover, to increase reliability, redundancy will be introduced at different levels. Three different options are currently being investigated for the front-end electronics and extensive test beam studies are planned to select the best option. One demonstrator prototype module is also planned to be inserted in TileCal in 2014 that will include hybrid electronic components able to probe the new design, but still compatible with the presen...

Industrial Production of the eight normal-conducting 200 MHz ACN cavities for the LHC

CERN Document Server

Chiaveri, Enrico; Linnecar, Trevor Paul R; Losito, R; Marque, S; Tückmantel, Joachim

2004-01-01

The LHC-ACN RF system consists of 8 normalconducting cavities and is designed to reduce beam losses in the LHC when injecting beams with longitudinal emittance > 0.7 eVs from the CERN SPS. The cavity design took into account the possibility of recuperating all the "ancillary" equipment (tuners, fundamental mode damper, High Order Mode (HOM) couplers) from the old CERN SPS 200MHz system. The cavities are made from OFE copper. The original ingots, procured in Austria, have been forged and pre-formed by pressing them with a 20 tons press, following a procedure defined and adapted for the unusual dimensions of these pieces. The raw components thus obtained were machined and then welded together with an electron beam. In order to get a good repeatability of the fundamental mode frequency across the eight cavities, a procedure has been established with the contractor for the final machining and welding leading to a spread in frequencies below ±20 kHz (< 0.01%). The cavities will be installed in the LHC when l...

Improving Electronic Resources through Holistic Budgeting

Science.gov (United States)

Kusik, James P.; Vargas, Mark A.

2009-01-01

To establish a more direct link between its collections and the educational goals of Saint Xavier University, the Byrne Memorial Library has adopted a "holistic" approach to collection development. This article examines how traditional budget practices influenced the library's selection of resources and describes how holistic collection…

Compact 400-Mhz Half-Wave Spoke Resonator Crab Cavity for the LHC Update

International Nuclear Information System (INIS)

Li, Zenghai

2010-01-01

Crab cavities are proposed for the LHC upgrade to improve the luminosity. There are two possible crab cavity installations for the LHC upgrade: the global scheme at Interaction Region (IR) 4 where the beam-beam separation is about 420-mm, and the local scheme at the IR5 where the beam-beam separation is only 194-mm. One of the design requirements as the result of a recent LHC-Crab cavity workshop is to develop a 400-MHz cavity design that can be utilized for either the global or local schemes at IR4 or IR5. Such a design would offer more flexibility for the final upgrade installation, as the final crabbing scheme is yet to be determined, and save R and D cost. The cavity size of such a design, however, is limited by the beam-beam separation at IR5 which can only accommodate a cavity with a horizontal size of about 145-mm, which is a design challenge for a 400-MHz cavity. To meet the new design requirements, we have developed a compact 400-MHz half-wave spoke resonator (HWSR) crab cavity that can fit into the tight spaces available at either IR4 or IR5. In this paper, we present the optimization of the HWSR cavity shape and the design of HOM, LOM, and SOM couplers for wakefield damping.

Fast pulse beam generation systems for electron accelerators

International Nuclear Information System (INIS)

Koontz, R.F.

1977-01-01

The fast pulse beam generation system to supply the SLAC storage ring, SPEAR, by the two one nanosecond bunch electron beam pulses is described. Generation of these pulses is accomplished with a combination of a fast pulsed grided gun and a synchronized transverse beam chopper. Fast gun based on spherical cathode-grid assembly has output current up to 2As. Fast pulse amplifier system can handle trains of short pulses with repetition rates up to 40 MHz during the 1.6 μs normal accelerating time. Chopping deflector system consists of a resonant coaxial line with the deflecting plates. The resonator frequency is 39.667 MHz. A schematic diagram of the resonant system is shown. The fast beam pickup system has a one hundred picosecond rise time overrall. Fast beam generation and chopper systems permit to generate almost any short or single bunch beam profile needed for experiments

Design study of a 25.5-MHz split coaxial RFQ

International Nuclear Information System (INIS)

Arai, Shigeaki; Imanishi, Akira; Morimoto, Teruhisa; Shibuya, Shinji; Tojyo, Eiki; Tokuda, Noboru.

1989-08-01

A 25.5-MHz split coaxial RFQ with modulated vanes is now being fabricated. The RFQ, 2.1 m in length and 0.9 m in diameter, will accelerate ions with a charge-to-mass ratio greater than 1/30 from 1 keV/n up to 45.4 keV/n. The design works on beam dynamics and cavity fabrication are reported. (author)

Clinician‐selected Electronic Information Resources do not Guarantee Accuracy in Answering Primary Care Physicians’ Information Needs. A review of: McKibbon, K. Ann, and Douglas B. Fridsma. “Effectiveness of Clinician‐selected Electronic Information Resources for Answering Primary Care Physicians’ Information Needs.” Journal of the American Medical Informatics Association 13.6 (2006: 653‐9.

Directory of Open Access Journals (Sweden)

Martha Ingrid Preddie

2008-03-01

Full Text Available Objective – To determine if electronic information resources selected by primary care physicians improve their ability to answer simulated clinical questions.Design – An observational study utilizing hour‐long interviews and think‐aloud protocols.Setting – The offices and clinics of primary care physicians in Canada and the United States.Subjects – Twenty‐five primary care physicians of whom 4 were women, 17 were from Canada, 22 were family physicians,and 24 were board certified.Methods – Participants provided responses to 23 multiple‐choice questions. Each physician then chose two questions and looked for the answers utilizing information resources of their own choice. The search processes, chosen resources and search times were noted. These were analyzed along with data on the accuracy of the answers and certainties related to the answer to each clinical question prior to the search.Main results – Twenty‐three physicians sought answers to 46 simulated clinical questions. Utilizing only electronic information resources, physicians spent a mean of 13.0 (SD 5.5 minutes searching for answers to the questions, an average of 7.3(SD 4.0 minutes for the first question and 5.8 (SD 2.2 minutes to answer the second question. On average, 1.8 resources were utilized per question. Resources that summarized information, such as the Cochrane Database of Systematic Reviews, UpToDate and Clinical Evidence, were favored 39.2% of the time, MEDLINE (Ovid and PubMed 35.7%, and Internet resources including Google 22.6%. Almost 50% of the search and retrieval strategies were keyword‐based, while MeSH, subheadings and limiting were used less frequently. On average, before searching physicians answered 10 of 23 (43.5% questions accurately. For questions that were searched using clinician‐selected electronic resources, 18 (39.1% of the 46 answers were accurate before searching, while 19 (42.1% were accurate after searching. The difference of

Analyses and optimization of Lee propagation model for LoRa 868 MHz network deployments in urban areas

Directory of Open Access Journals (Sweden)

Dobrilović Dalibor

2017-01-01

Full Text Available In the recent period, fast ICT expansion and rapid appearance of new technologies raised the importance of fast and accurate planning and deployment of emerging communication technologies, especially wireless ones. In this paper is analyzed possible usage of Lee propagation model for planning, design and management of networks based on LoRa 868MHz technology. LoRa is wireless technology which can be deployed in various Internet of Things and Smart City scenarios in urban areas. The analyses are based on comparison of field measurements with model calculations. Besides the analyses of Lee propagation model usability, the possible optimization of the model is discussed as well. The research results can be used for accurate design, planning and for preparation of high-performance wireless resource management of various Internet of Things and Smart City applications in urban areas based on LoRa or similar wireless technology. The equipment used for measurements is based on open-source hardware.

Review of material recovery from used electric and electronic equipment-alternative options for resource conservation.

Science.gov (United States)

Friege, Henning

2012-09-01

For waste from electric and electronic equipment, the WEEE Directive stipulates the separate collection of electric and electronic waste. As to new electric and electronic devices, the Restriction of Hazardous Substances (RoHS) Directive bans the use of certain chemicals dangerous for man and environment. From the implementation of the WEEE directive, many unsolved problems have been documented: poor collection success, emission of dangerous substances during collection and recycling, irretrievable loss of valuable metals among others. As to RoHS, data from the literature show a satisfying success. The problems identified in the process can be reduced to some basic dilemmas at the borders between waste management, product policy and chemical safety. The objectives of the WEEE Directive and the specific targets for use and recycling of appliances are not consistent. There is no focus on scarce resources. Extended producer responsibility is not sufficient to guarantee sustainable waste management. Waste management reaches its limits due to problems of implementation but also due to physical laws. A holistic approach is necessary looking at all branch points and sinks in the stream of used products and waste from electric and electronic equipment. This may be done with respect to the general rules for sustainable management of material streams covering the three dimensions of sustainable policy. The relationships between the players in the field of electric and electronic devices have to be taken into account. Most of the problems identified in the implementation process will not be solved by the current amendment of the WEEE Directive.

The Green Bank Third (GB3) survey of extragalactic radio sources at 1400 MHz

International Nuclear Information System (INIS)

Rys, S.; Machalski, J.

1987-01-01

The NRAO 91-m radio telescope in Green Bank, West Virginia was used to make a 1400-MHz sky survey covering an area of 0.0988 sr at declinations 70 deg ≤ δ 1950 < 76.8 deg with 10.1 x 10.5 arcmin resolution. This survey ends the series of smaller than 1-sr surveys made at 1400 MHz with that telescope and four-feed radiometer. A catalogue of 502 radiosources is presented, statistically complete to 112 mJy, which is about five times the rms noise and extragalactic confusion. The observations and data reduction are briefly summarized; the position and flux density errors are discussed. 13 refs., 2 tabs. (author)

Design Study for 10MHz Beam Frequency of Post-Accelerated RIBs at HIE-ISOLDE

CERN Document Server

Fraser, M A; Magdau, I B

2013-01-01

An increased bunch spacing of approximately 100 ns is requested by several research groups targeting experimental physics at HIE-ISOLDE. A design study testing the feasibility of retrofitting the existing 101.28MHz REX (Radioactive ion beam EXperiment) RFQ [1] with a subharmonic external pre-buncher at the ISOLDE radioactive nuclear beam facility has been carried out as a means of decreasing the beam frequency by a factor of 10. The proposed scheme for the 10MHz bunch repetition frequency is presented and its performance assessed with beam dynamics simulations. The opportunity to reduce the longitudinal emittance formed in the RFQ is discussed along with the options for chopping the satellite bunches populated in the bunching process.

Measurement of electrodynamics characteristics of higher order modes for harmonic cavity at 2400 MHz

Science.gov (United States)

Shashkov, Ya V.; Sobenin, N. P.; Gusarova, M. A.; Lalayan, M. V.; Bazyl, D. S.; Donetskiy, R. V.; Orlov, A. I.; Zobov, M. M.; Zavadtsev, A. A.

2016-09-01

In the frameworks of the High Luminosity Large Hadron Collider (HL-LHC) upgrade program an application of additional superconducting harmonic cavities operating at 800 MHz is currently under discussion. As a possible candidate, an assembly of two cavities with grooved beam pipes connected by a drift tube and housed in a common cryomodule, was proposed. In this article we discuss measurements of loaded Q-factors of higher order modes (HOM) performed on a scaled aluminium single cell cavity prototype with the fundamental frequency of 2400 MHz and on an array of two such cavities connected by a narrow beam pipe. The measurements were performed for the system with and without the matching load in the drift tube..

Charting a Course through CORAL: Texas A&M University Libraries' Experience Implementing an Open-Source Electronic Resources Management System

Science.gov (United States)

Hartnett, Eric; Beh, Eugenia; Resnick, Taryn; Ugaz, Ana; Tabacaru, Simona

2013-01-01

In 2010, after two previous unsuccessful attempts at electronic resources management system (ERMS) implementation, Texas A&M University (TAMU) Libraries set out once again to find an ERMS that would fit its needs. After surveying the field, TAMU Libraries selected the University of Notre Dame Hesburgh Libraries-developed, open-source ERMS,…

MHz gravitational waves from short-term anisotropic inflation

International Nuclear Information System (INIS)

Ito, Asuka; Soda, Jiro

2016-01-01

We reveal the universality of short-term anisotropic inflation. As a demonstration, we study inflation with an exponential type gauge kinetic function which is ubiquitous in models obtained by dimensional reduction from higher dimensional fundamental theory. It turns out that an anisotropic inflation universally takes place in the later stage of conventional inflation. Remarkably, we find that primordial gravitational waves with a peak amplitude around 10 −26 ∼10 −27 are copiously produced in high-frequency bands 10 MHz∼100 MHz. If we could detect such gravitational waves in future, we would be able to probe higher dimensional fundamental theory.

Digital processing with single electrons for arbitrary waveform generation of current

Science.gov (United States)

Okazaki, Yuma; Nakamura, Shuji; Onomitsu, Koji; Kaneko, Nobu-Hisa

2018-03-01

We demonstrate arbitrary waveform generation of current using a GaAs-based single-electron pump. In our experiment, a digital processing algorithm known as delta-sigma modulation is incorporated into single-electron pumping to generate a density-modulated single-electron stream, by which we demonstrate the generation of arbitrary waveforms of current including sinusoidal, square, and triangular waves with a peak-to-peak amplitude of approximately 10 pA and an output bandwidth ranging from dc to close to 1 MHz. The developed current generator can be used as the precise and calculable current reference required for measurements of current noise in low-temperature experiments.

Electric field and electron density thresholds for coherent auroral echo onset

International Nuclear Information System (INIS)

Kustov, A.V.; Uspensky, M.V.; Sofko, G.J.; Koehler, J.A.; Jones, G.O.L.; Williams, P.J.S.

1993-01-01

The authors study the threshold dependence of electron density and electric field for the observation of coherent auroral echo onset. They make use of Polar Geophysical Institute 83 MHz auroral radar and the EISCAT facility in Scandanavia, to simultaneously get plasma parameter information and coherent scatter observations. They observe an electron density threshold of roughly 2.5x10 11 m -3 for electric fields of 15 - 20 mV/m (near the Farley-Buneman instability threshold). For electric fields of 5 - 10 mV/m echos are not observed for even twice the previous electron density. Echo strength is observed to have other parametric dependences

Performance of the Electronic Readout of the ATLAS Liquid Argon Calorimeters

CERN Document Server

Abreu, H; Aleksa, M; Aperio Bella, L; Archambault, JP; Arfaoui, S; Arnaez, O; Auge, E; Aurousseau, M; Bahinipati, S; Ban, J; Banfi, D; Barajas, A; Barillari, T; Bazan, A; Bellachia, F; Beloborodova, O; Benchekroun, D; Benslama, K; Berger, N; Berghaus, F; Bernat, P; Bernier, R; Besson, N; Binet, S; Blanchard, JB; Blondel, A; Bobrovnikov, V; Bohner, O; Boonekamp, M; Bordoni, S; Bouchel, M; Bourdarios, C; Bozzone, A; Braun, HM; Breton, D; Brettel, H; Brooijmans, G; Caputo, R; Carli, T; Carminati, L; Caughron, S; Cavalleri, P; Cavalli, D; Chareyre, E; Chase, RL; Chekulaev, SV; Chen, H; Cheplakov, A; Chiche, R; Citterio, M; Cojocaru, C; Colas, J; Collard, C; Collot, J; Consonni, M; Cooke, M; Copic, K; Costa, GC; Courneyea, L; Cuisy, D; Cwienk, WD; Damazio, D; Dannheim, D; De Cecco, S; De La Broise, X; De La Taille, C; de Vivie, JB; Debennerot, B; Delagnes, E; Delmastro, M; Derue, F; Dhaliwal, S; Di Ciaccio, L; Doan, O; Dudziak, F; Duflot, L; Dumont-Dayot, N; Dzahini, D; Elles, S; Ertel, E; Escalier, M; Etienvre, AI; Falleau, I; Fanti, M; Farooque, T; Favre, P; Fayard, Louis; Fent, J; Ferencei, J; Fischer, A; Fournier, D; Fournier, L; Fras, M; Froeschl, R; Gadfort, T; Gallin-Martel, ML; Gibson, A; Gillberg, D; Gingrich, DM; Göpfert, T; Goodson, J; Gouighri, M; Goy, C; Grassi, V; Gray, J; Guillemin, T; Guo, B; Habring, J; Handel, C; Heelan, L; Heintz, H; Helary, L; Henrot-Versille, S; Hervas, L; Hobbs, J; Hoffman, J; Hostachy, JY; Hoummada, A; Hrivnac, J; Hrynova, T; Hubaut, F; Huber, J; Iconomidou-Fayard, L; Iengo, P; Imbert, P; Ishmukhametov, R; Jantsch, A; Javadov, N; Jezequel, S; Jimenez Belenguer, M; Ju, XY; Kado, M; Kalinowski, A; Kar, D; Karev, A; Katsanos, I; Kazarinov, M; Kerschen, N; Kierstead, J; Kim, MS; Kiryunin, A; Kladiva, E; Knecht, N; Kobel, M; Koletsou, I; König, S; Krieger, P; Kukhtin, V; Kuna, M; Kurchaninov, L; Labbe, J; Lacour, D; Ladygin, E; Lafaye, R; Laforge, B; Lamarra, D; Lampl, W; Lanni, F; Laplace, S; Laskus, H; Le Coguie, A; Le Dortz, O; Le Maner, C; Lechowski, M; Lee, SC; Lefebvre, M; Leonhardt, K; Lethiec, L; Leveque, J; Liang, Z; Liu, C; Liu, T; Liu, Y; Loch, P; Lu, J; Ma, H; Mader, W; Majewski, S; Makovec, N; Makowiecki, D; Mandelli, L; Mangeard, PS; Mansoulie, B; Marchand, JF; Marchiori, G; Martin, D; Martin-Chassard, G; Martin dit Latour, B; Marzin, A; Maslennikov, A; Massol, N; Matricon, P; Maximov, D; Mazzanti, M; McCarthy, T; McPherson, R; Menke, S; Meyer, JP; Ming, Y; Monnier, E; Mooshofer, P; Neganov, A; Niedercorn, F; Nikolic-Audit, I; Nugent, IM; Oakham, G; Oberlack, H; Ocariz, J; Odier, J; Oram, CJ; Orlov, I; Orr, R; Parsons, JA; Peleganchuk, S; Penson, A; Perini, L; Perrodo, P; Perrot, G; Perus, A; Petit, E; Pisarev, I; Plamondon, M; Poffenberger, P; Poggioli, L; Pospelov, G; Pralavorio, P; Prast, J; Prudent, X; Przysiezniak, H; Puzo, P; Quentin, M; Radeka, V; Rajagopalan, S; Rauter, E; Reimann, O; Rescia, S; Resende, B; Richer, JP; Ridel, M; Rios, R; Roos, L; Rosenbaum, G; Rosenzweig, H; Rossetto, O; Roudil, W; Rousseau, D; Ruan, X; Rudert, A; Rusakovich, N; Rusquart, P; Rutherfoord, J; Sauvage, G; Savine, A; Schaarschmidt, J; Schacht, P; Schaffer, A; Schram, M; Schwemling, P; Seguin Moreau, N; Seifert, F; Serin, L; Seuster, R; Shalyugin, A; Shupe, M; Simion, S; Sinervo, P; Sippach, W; Skovpen, K; Sliwa, R; Soukharev, A; Spano, F; Stavina, P; Straessner, A; Strizenec, P; Stroynowski, R; Talyshev, A; Tapprogge, S; Tarrade, F; Tartarelli, GF; Teuscher, R; Tikhonov, Yu; Tocut, V; Tompkins, D; Thompson, P; Tisserant, S; Todorov, T; Tomasz, F; Trincaz-Duvoid, S; Trinh, Thi N; Trochet, S; Trocme, B; Tschann-Grimm, K; Tsionou, D; Ueno, R; Unal, G; Urbaniec, D; Usov, Y; Voss, K; Veillet, JJ; Vincter, M; Vogt, S; Weng, Z; Whalen, K; Wicek, F; Wilkens, H; Wingerter-Seez, I; Wulf, E; Yang, Z; Ye, J; Yuan, L; Yurkewicz, A; Zarzhitsky, P; Zerwas, D; Zhang, H; Zhang, L; Zhou, N; Zimmer, J; Zitoun, R; Zivkovic, L

2010-01-01

The ATLAS detector has been designed for operation at the Large Hadron Collider at CERN. ATLAS includes electromagnetic and hadronic liquid argon calorimeters, with almost 200,000 channels of data that must be sampled at the LHC bunch crossing frequency of 40 MHz. The calorimeter electronics calibration and readout are performed by custom electronics developed specifically for these purposes. This paper describes the system performance of the ATLAS liquid argon calibration and readout electronics, including noise, energy and time resolution, and long term stability, with data taken mainly from full-system calibration runs performed after installation of the system in the ATLAS detector hall at CERN.

Programmable optical processor chips: toward photonic RF filters with DSP-level flexibility and MHz-band selectivity

Directory of Open Access Journals (Sweden)

Xie Yiwei

2017-12-01

Full Text Available Integrated optical signal processors have been identified as a powerful engine for optical processing of microwave signals. They enable wideband and stable signal processing operations on miniaturized chips with ultimate control precision. As a promising application, such processors enables photonic implementations of reconfigurable radio frequency (RF filters with wide design flexibility, large bandwidth, and high-frequency selectivity. This is a key technology for photonic-assisted RF front ends that opens a path to overcoming the bandwidth limitation of current digital electronics. Here, the recent progress of integrated optical signal processors for implementing such RF filters is reviewed. We highlight the use of a low-loss, high-index-contrast stoichiometric silicon nitride waveguide which promises to serve as a practical material platform for realizing high-performance optical signal processors and points toward photonic RF filters with digital signal processing (DSP-level flexibility, hundreds-GHz bandwidth, MHz-band frequency selectivity, and full system integration on a chip scale.

Production and Test of 352 MHZ Niobum-Sputtered Reduced-$\\beta$ Cavities

CERN Document Server

Benvenuti, Cristoforo; Calatroni, Sergio; Chiaveri, Enrico; Tückmantel, Joachim

1997-01-01

Three types of 352 MHz single-cell cavities foreseen for different particle speeds (v/c=0.8, 0.625 and 0.48) have been designed and built with the niobium sputtered on copper technique. We report on the results of the cold tests at 4.5 and 2.5 K and the actual status of the data analysis.

Status of HLT1 sequence and path towards 30 MHz

CERN Document Server

De Cian, Michel; Gligorov, Vladimir; Hasse, Christoph; Hulsbergen, Wouter; Latham, Thomas Edward; Ponce, Sebastien; Quagliani, Renato; Schreiner, Henry Fredrick; Stemmle, Simon Benedikt; Van Tilburg, Jeroen; Zdybal, Milosz Jerzy; Williams, J Michael

2018-01-01

We present the current status of the HLT1 reconstruction sequence for the LHCb upgrade, both in terms of the number of events which can be processed per second and the achievable physics performance on a selected range of benchmark modes. We present detailed profiling of the various algorithms, describe the bottlenecks, and outline a strategy towards an HLT1 able to process the LHCb upgrade data at 30 MHz

Δt tuneup procedure for the LAMPF 805-MHz linac

International Nuclear Information System (INIS)

Crandall, K.R.

1976-05-01

An important part of tuning the LAMPF accelerator is the adjustment of the phases and amplitudes in the 805-MHz linac. The technique used is called the Δt procedure because of the time-of-flight measurements that are required. The theory behind the Δt procedure, a brief description of the hardware, and a description of the many computer programs that have been written to implement the procedure are presented

Designing a model of electronic human resource management’s implementation at the Ministry of Communications and Information Technology

Directory of Open Access Journals (Sweden)

Mirali Seyednaghavi

2017-06-01

Full Text Available : In the first phase of this study a model for electronic human resource management in government agencies based on new public services was explored by using software MAXQDA, then in the second phase, relationship between the elements of the theory were tested using software Smart PLS2. So the aim of this study is to design a model of electronic human resource management’s implementation at the Ministry of Communications and Information Technology. In this regard, according to Strauss and Corbin’s structured plan, five hypotheses were tested. Quantitative data analysis indicates that the pressures of the policies and global perspectives cause to move toward e-HRM. Among the contextual conditions macro structural mechanisms, considerations of actors, governance considerations have a significant impact on the strategy of new public services and therefore lead to the consequences of its implementation in public organizations. The findings suggest that e-HRM does not have a positive and meaningful impact on new public services, and in our country, although the recent political developments have somehow removed the gap between public policy makers, administrators, and the public, but there is still a long way to go.

MHz rate and efficient synchronous heralding of single photons at telecom wavelengths.

Science.gov (United States)

Pomarico, Enrico; Sanguinetti, Bruno; Guerreiro, Thiago; Thew, Rob; Zbinden, Hugo

2012-10-08

We report on the realization of a synchronous source of heralded single photons at telecom wavelengths with MHz heralding rates and high heralding efficiency. This source is based on the generation of photon pairs at 810 and 1550 nm via Spontaneous Parametric Down Conversion (SPDC) in a 1 cm periodically poled lithium niobate (PPLN) crystal pumped by a 532 nm pulsed laser. As high rates are fundamental for multi-photon experiments, we show that single telecom photons can be announced at 4.4 MHz rate with 45% heralding efficiency. When we focus only on the optimization of the coupling of the heralded photon, the heralding efficiency can be increased up to 80%. Furthermore, we experimentally observe that group velocity mismatch inside long crystals pumped in a pulsed mode affects the spectrum of the emitted photons and their fibre coupling efficiency. The length of the crystal in this source has been chosen as a trade off between high brightness and high coupling efficiency.

Ion beam neutralization with ferroelectrically generated electron beams

Energy Technology Data Exchange (ETDEWEB)

Herleb, U; Riege, H [European Organization for Nuclear Research, Geneva (Switzerland). LHC Division

1997-12-31

A technique for ion beam space-charge neutralization with pulsed electron beams is described. The intensity of multiply-charged ions produced with a laser ion source can be enhanced or decreased separately with electron beam trains of MHz repetition rate. These are generated with ferroelectric cathodes, which are pulsed in synchronization with the laser ion source. The pulsed electron beams guide the ion beam in a similar way to the alternating gradient focusing of charged particle beams in circular accelerators such as synchrotrons. This new neutralization technology overcomes the Langmuir-Child space-charge limit and may in future allow ion beam currents to be transported with intensities by orders of magnitude higher than those which can be accelerated today in a single vacuum tube. (author). 6 figs., 10 refs.

200 ps FWHM and 100 MHz repetition rate ultrafast gated camera for optical medical functional imaging

Science.gov (United States)

Uhring, Wilfried; Poulet, Patrick; Hanselmann, Walter; Glazenborg, René; Zint, Virginie; Nouizi, Farouk; Dubois, Benoit; Hirschi, Werner

2012-04-01

The paper describes the realization of a complete optical imaging device to clinical applications like brain functional imaging by time-resolved, spectroscopic diffuse optical tomography. The entire instrument is assembled in a unique setup that includes a light source, an ultrafast time-gated intensified camera and all the electronic control units. The light source is composed of four near infrared laser diodes driven by a nanosecond electrical pulse generator working in a sequential mode at a repetition rate of 100 MHz. The resulting light pulses, at four wavelengths, are less than 80 ps FWHM. They are injected in a four-furcated optical fiber ended with a frontal light distributor to obtain a uniform illumination spot directed towards the head of the patient. Photons back-scattered by the subject are detected by the intensified CCD camera; there are resolved according to their time of flight inside the head. The very core of the intensified camera system is the image intensifier tube and its associated electrical pulse generator. The ultrafast generator produces 50 V pulses, at a repetition rate of 100 MHz and a width corresponding to the 200 ps requested gate. The photocathode and the Micro-Channel-Plate of the intensifier have been specially designed to enhance the electromagnetic wave propagation and reduce the power loss and heat that are prejudicial to the quality of the image. The whole instrumentation system is controlled by an FPGA based module. The timing of the light pulses and the photocathode gating is precisely adjustable with a step of 9 ps. All the acquisition parameters are configurable via software through an USB plug and the image data are transferred to a PC via an Ethernet link. The compactness of the device makes it a perfect device for bedside clinical applications.

Resonance Frequency Readout Circuit for a 900 MHz SAW Device.

Science.gov (United States)

Liu, Heng; Zhang, Chun; Weng, Zhaoyang; Guo, Yanshu; Wang, Zhihua

2017-09-15

A monolithic resonance frequency readout circuit with high resolution and short measurement time is presented for a 900 MHz RF surface acoustic wave (SAW) sensor. The readout circuit is composed of a fractional-N phase-locked loop (PLL) as the stimulus source to the SAW device and a phase-based resonance frequency detecting circuit using successive approximation (SAR). A new resonance frequency searching strategy has been proposed based on the fact that the SAW device phase-frequency response crosses zero monotonically around the resonance frequency. A dedicated instant phase difference detecting circuit is adopted to facilitate the fast SAR operation for resonance frequency searching. The readout circuit has been implemented in 180 nm CMOS technology with a core area of 3.24 mm². In the experiment, it works with a 900 MHz SAW resonator with a quality factor of Q = 130. Experimental results show that the readout circuit consumes 7 mW power from 1.6 V supply. The frequency resolution is 733 Hz, and the relative accuracy is 0.82 ppm, and it takes 0.48 ms to complete one measurement. Compared to the previous results in the literature, this work has achieved the shortest measurement time with a trade-off between measurement accuracy and measurement time.

Experimental Limits on Gravitational Waves in the MHz frequency Range

Energy Technology Data Exchange (ETDEWEB)

Lanza, Robert Jr. [Univ. of Chicago, IL (United States)

2015-03-01

This thesis presents the results of a search for gravitational waves in the 1-11MHz frequency range using dual power-recycled Michelson laser interferometers at Fermi National Accelerator Laboratory. An unprecedented level of sensitivity to gravitational waves in this frequency range has been achieved by cross-correlating the output fluctuations of two identical and colocated 40m long interferometers. This technique produces sensitivities better than two orders of magnitude below the quantum shot-noise limit, within integration times of less than 1 hour. 95% confidence level upper limits are placed on the strain amplitude of MHz frequency gravitational waves at the 10^-21 Hz^-1/2 level, constituting the best direct limits to date at these frequencies. For gravitational wave power distributed over this frequency range, a broadband upper limit of 2.4 x 10^-21Hz^-1/2 at 95% confidence level is also obtained. This thesis covers the detector technology, the commissioning and calibration of the instrument, the statistical data analysis, and the gravitational wave limit results. Particular attention is paid to the end-to-end calibration of the instrument’s sensitivity to differential arm length motion, and so to gravitational wave strain. A detailed statistical analysis of the data is presented as well.

The module of methodical support in system of electronic educational resources as the innovative element of the modern maintenance of formation

Directory of Open Access Journals (Sweden)

Ольга Николаевна Крылова

2009-06-01

Full Text Available The article introduces some results of research, which were devoted to evaluation of tearches' mobility to introduce innovations in the contents of education. The author considers innovative potential of modules of the methodical support for system of electronic educational resources.

Comparison of higher order modes damping techniques for 800 MHz single cell superconducting cavities

Energy Technology Data Exchange (ETDEWEB)

Shashkov, Ya.V., E-mail: shashkovyv@mail.ru [National Research Nuclear University MEPhI, Moscow (Russian Federation); Sobenin, N.P.; Petrushina, I.I. [National Research Nuclear University MEPhI, Moscow (Russian Federation); Zobov, M.M. [Laboratori Nazionali di Frascati INFN, Rome (Italy)

2014-12-11

At present, applications of 800 MHz harmonic cavities in both bunch lengthening and shortening regimes are under consideration and discussion in the framework of the High Luminosity LHC project. In this paper we study electromagnetic characteristics of high order modes (HOMs) for a single cell 800 MHz superconducting cavity and arrays of such cavities connected by drifts tubes. Different techniques for the HOMs damping such as beam pipe grooves, coaxial-notch loads, fluted beam pipes etc. are investigated and compared. The influence of the sizes and geometry of the drift tubes on the HOMs damping is analyzed. The problems of a multipacting discharge in the considered structures are discussed and the operating frequency detuning due to the Lorentz force is evaluated.

Comparison of higher order modes damping techniques for 800 MHz single cell superconducting cavities

Science.gov (United States)

Shashkov, Ya. V.; Sobenin, N. P.; Petrushina, I. I.; Zobov, M. M.

2014-12-01

At present, applications of 800 MHz harmonic cavities in both bunch lengthening and shortening regimes are under consideration and discussion in the framework of the High Luminosity LHC project. In this paper we study electromagnetic characteristics of high order modes (HOMs) for a single cell 800 MHz superconducting cavity and arrays of such cavities connected by drifts tubes. Different techniques for the HOMs damping such as beam pipe grooves, coaxial-notch loads, fluted beam pipes etc. are investigated and compared. The influence of the sizes and geometry of the drift tubes on the HOMs damping is analyzed. The problems of a multipacting discharge in the considered structures are discussed and the operating frequency detuning due to the Lorentz force is evaluated.

Measuring personal exposure from 900MHz mobile phone base stations in Australia and Belgium using a novel personal distributed exposimeter

NARCIS (Netherlands)

Bhatt, Chhavi Raj; Thielens, Arno; Redmayne, Mary; Abramson, Michael J; Billah, Baki; Sim, Malcolm R; Vermeulen, Roel; Martens, Luc; Joseph, Wout; Benke, Geza

2016-01-01

The aims of this study were to: i) measure personal exposure in the Global System for Mobile communications (GSM) 900MHz downlink (DL) frequency band with two systems of exposimeters, a personal distributed exposimeter (PDE) and a pair of ExpoM-RFs, ii) compare the GSM 900MHz DL exposures across

480 MHz 10-tap Clock Generator Using Edge-Combiner DLL for USB 2.0 Applications

Directory of Open Access Journals (Sweden)

Takashi Kawamoto

2012-01-01

Full Text Available A clock generator with an edge-combiner DLL (ECDLL has been developed for USB 2.0 applications. The clock generator generates 480 MHz 10-tap output signals from a 12 MHz reference signal and consists of three DLLs to shrink the design area so that it is smaller than a conventional one based on a PLL. Each DLL is applied to our proposed shot pulse reset technique to prevent from a harmonic lock and is applied to a voltage-controlled delay line (VCDL with a trimming function to operate against any process voltage temperature (PVT variations. A 90 nm CMOS process was used to fabricate our proposed clock generator. The 480 MHz 10-tap output signals satisfy the USB 2.0 specifications. A power consumption is less than 1.3 mW and a locking time is less than 3.5 μs, which are far less than a conventional one, 10.0 μs. The design area is 200×225 μm, which is half that of the conventional one.

Mechanical design and fabrication of the VHF-gun, the Berkeley normal-conducting continuous-wave high-brightness electron source

Science.gov (United States)

Wells, R. P.; Ghiorso, W.; Staples, J.; Huang, T. M.; Sannibale, F.; Kramasz, T. D.

2016-02-01

A high repetition rate, MHz-class, high-brightness electron source is a key element in future high-repetition-rate x-ray free electron laser-based light sources. The VHF-gun, a novel low frequency radio-frequency gun, is the Lawrence Berkeley National Laboratory (LBNL) response to that need. The gun design is based on a normal conducting, single cell cavity resonating at 186 MHz in the VHF band and capable of continuous wave operation while still delivering the high accelerating fields at the cathode required for the high brightness performance. The VHF-gun was fabricated and successfully commissioned in the framework of the Advanced Photo-injector EXperiment, an injector built at LBNL to demonstrate the capability of the gun to deliver the required beam quality. The basis for the selection of the VHF-gun technology, novel design features, and fabrication techniques are described.

A 500-MHz x-ray counting system with a silicon avalanche photodiode

International Nuclear Information System (INIS)

Kishimoto, Shunji

2009-01-01

In the present measurements using a Si-APD X-ray detector and a 500-MHz counting system, the maximum output rate of 3.3x10 8 s -1 was achieved for 8-keV X-rays in beamline BL-14A of the Photon Factory. A small Si-APD of 4-pF electric capacity was used as the detector device in order to output a pulse of a width shorter than 2 ns on the baseline. For processing the fast pulses, the discriminator and the scaler having a throughput of >500 MHz, were prepared. Since the acceleration frequency at the PF ring was 500.1 MHz and the empty-bunch spacing was 12/312 bunches per circumference, the expected maximum rate was 4.8x10 8s-1 according to the counting model for a pulsed photon source. The reason why the present system did not reach the expected value was the baseline shift at the amplifier outputs. The rise of +0.2 V was observed at a discriminator output of 3.3x10 8 s -1 , while the pulse height was lower than 0.2 V. The baseline shift was caused by an AC coupling circuit in the amplifier. If a DC coupling circuit can be used for the amplifier, instead of the AC coupling circuit, or an active adjustment to compensate the baseline shift is installed, the counting system will show an ideal response. Although the present system including NIM modules was not so compact, we would like to develop a new fast-counting circuit for a Si-APD array detector of more than 100 channels of small pixels, in near future. (author)

Self-organised critical features in soil radon and MHz electromagnetic disturbances: Results from environmental monitoring in Greece

International Nuclear Information System (INIS)

Petraki, Ermioni; Nikolopoulos, Dimitrios; Fotopoulos, Anaxagoras; Panagiotaras, Dionisios; Koulouras, Grigorios; Zisos, Athanasios; Nomicos, Constantinos; Louizi, Anna; Stonham, John

2013-01-01

This paper addresses the issues of self-organised critical behaviour of soil-radon and MHz-electromagnetic disorders during intense seismic activity in SW Greece. A significant radon signal is re-analysed for environmental influences with Fast Fourier Transform and multivariate statistics. Self-organisation of signals is investigated via fractal evolving techniques and detrended fluctuation analysis. New lengthy radon data are presented and analysed accordingly. The data did not show self-similarities. Similar analysis applied to new important concurrent MHz-electromagnetic signals revealed analogous behaviour to radon. The signals precursory value is discussed. - Highlights: ► New radon–MHz signals for an area with peculiar radon disorders on 2008. ► Use of spectrograms-multivariate statistics in analysing environmental parameters. ► Spectral fractal techniques and Detrended Fluctuation Analysis in all signals. ► Pre-earthquake signals followed fractional Brownian motion model. ► Hurst analysis showed persistent–antipersistent self-organised critical patterns.

Interference Measurements in the European 868 MHz ISM Band with Focus on LoRa and SigFox

DEFF Research Database (Denmark)

Lauridsen, Mads; Vejlgaard, Benny; Kovács, István

2017-01-01

In this measurement study the signal activity and power levels are measured in the European Industrial, Scientific, and Medical band 863-870 MHz in the city of Aalborg, Denmark. The target is to determine if there is any interference, which may impact deployment of Internet of Things devices....... The focus is on the Low Power Wide Area technologies LoRa and SigFox. The measurements show that there is a 22-33 % probability of interfering signals above -105 dBm within the mandatory LoRa and SigFox 868.0-868.6 MHz band in a shopping area and a business park in downtown Aalborg, which thus limits...... the potential coverage and capacity of LoRa and SigFox. However, the probability of interference is less than 3 % in the three other measurement locations in Aalborg. Finally, a hospital and an industrial area are shown to experience high activity in the RFID subband 865-868 MHz, while the wireless audio band...

Impact of Electronic Resources and Usage in Academic Libraries in Ghana: Evidence from Koforidua Polytechnic & All Nations University College, Ghana

Science.gov (United States)

Akussah, Maxwell; Asante, Edward; Adu-Sarkodee, Rosemary

2015-01-01

The study investigates the relationship between impact of electronic resources and its usage in academic libraries in Ghana: evidence from Koforidua Polytechnic & All Nations University College, Ghana. The study was a quantitative approach using questionnaire to gather data and information. A valid response rate of 58.5% was assumed. SPSS…

A search for interplanetary scintillation of Cygnus A at 81.5 MHz

International Nuclear Information System (INIS)

Tsien, S.C.; Duffett-Smith, P.J.

1982-01-01

IPS observations of Cygnus A at 81.5 MHz with the Cambridge 3.6-hectare array set an upper limit on the scintillation of 0.07 per cent of the total flux density. This suggests that the hotspots seen at high frequencies are much less prominent at low frequencies. (author)

Operation of a 473 MHz four-rod cavity RFQ

International Nuclear Information System (INIS)

Kazimi, R.; Huson, F.R.; Mackay, W.W.; Meitzler, C.R.

1992-01-01

We have constructed a new type of four-rod Radio Frequency Quadrupole to operate at 473 MHz. Four-rod structures have not previously been built for such a high frequency. The RFQ is designed to accelerate 10 mA of H - ions from 30 keV to 0.5 MeV. The rf measurements and beam test of the RFQ have been performed successfully. Here we present operational results of the RFQ system including measurements of the beam current, the required rf power, energy, energy spread, and emittance. (Author) 8 refs., 6 figs., 2 tabs

Miniaturization, Packaging, and Thermal Analysis of Power Electronics Modules

OpenAIRE

Lostetter, Alexander B.

1998-01-01

High power circuits, those involving high levels of voltages and currents to produce several kilowatts of power, would possess an optimized efficiency when driven at high frequencies (on the order of MHz). Such an approach would greatly reduce the size of capacitive and magnetic components, and thus ultimately reduce the cost of the power electronic circuits. The problem with this strategy in conventional packaging, however, is that at high frequencies, interconnects between the power devic...

Initial Demonstration of 9-MHz Framing Camera Rates on the FAST UV Drive Laser Pulse Trains

Energy Technology Data Exchange (ETDEWEB)

Lumpkin, A. H. [Fermilab; Edstrom Jr., D. [Fermilab; Ruan, J. [Fermilab

2016-10-09

We report the configuration of a Hamamatsu C5680 streak camera as a framing camera to record transverse spatial information of green-component laser micropulses at 3- and 9-MHz rates for the first time. The latter is near the time scale of the ~7.5-MHz revolution frequency of the Integrable Optics Test Accelerator (IOTA) ring and its expected synchroton radiation source temporal structure. The 2-D images are recorded with a Gig-E readout CCD camera. We also report a first proof of principle with an OTR source using the linac streak camera in a semi-framing mode.

Synchronization and sequencing of data acquisition and control electronics at the European X-ray free electron laser

International Nuclear Information System (INIS)

Gessler, Patrick

2015-11-01

The 3.5 km long European X-Ray Free Electron Laser, currently under construction in northern Germany, will deliver bursts of up to 2700 short X-ray pulses every 100 ms, providing wavelengths between 0.05 and 6 nm, and a repetition rate of 4.5 MHz to several experiment stations. It allows in-depth research in various scientific fields. In order to set-up the beam, position samples and capture the measured variables, information from the accelerator, diagnostic devices and detectors have to be digitized, converted, processed, transferred, concentrated, distributed, reorganized, controlled and saved. All these steps have to be accurately synchronized and sequenced relative to the actual electron bunch or photon pulse in order to guarantee correct data acquisition timings and unique identification of each bunch passing the beamlines. This document provides a complete description of the planning, design, realization and evaluation of the European XFEL Timing System, which implements the synchronization and sequencing of the data acquisition and control electronics for the European X-Ray Free-Electron Laser Facility.

Electronics and Algorithms for HOM Based Beam Diagnostics

Science.gov (United States)

Frisch, Josef; Baboi, Nicoleta; Eddy, Nathan; Nagaitsev, Sergei; Hensler, Olaf; McCormick, Douglas; May, Justin; Molloy, Stephen; Napoly, Olivier; Paparella, Rita; Petrosyan, Lyudvig; Ross, Marc; Simon, Claire; Smith, Tonee

2006-11-01

The signals from the Higher Order Mode (HOM) ports on superconducting cavities can be used as beam position monitors and to do survey structure alignment. A HOM-based diagnostic system has been installed to instrument both couplers on each of the 40 cryogenic accelerating structures in the DESY TTF2 Linac. The electronics uses a single stage down conversion from the 1.7 GHz HOM spectral line to a 20MHz IF which has been digitized. The electronics is based on low cost surface mount components suitable for large scale production. The analysis of the HOM data is based on Singular Value Decomposition. The response of the OM modes is calibrated using conventional BPMs.

Damping of resistive instability in UNK-1 with digital electronics in feedback

International Nuclear Information System (INIS)

Zhabitskij, V.M.; Ivanov, I.N.; Korenev, I.L.; Yudin, L.A.

1991-01-01

The basis of resistive instability damper system for the UNK-1 is obtained. The system for each of two directions of beam transverse oscillations includes two pairs of pick-up electrodes and damping kickers connected by delayed negative feedback with digital electronics. The requirements for digital electronics in feedback are discussed. The influence of a notch filter is under consideration. In turns out that a 0.8 MHz feedback system damps the resistive instability in the UNK-1 with increment of 0.7 revolution frequency (for low frequencies). 7 refs.; 8 figs

Utilization of Electronic Information Resources by Undergraduate Students of University of Ibadan: A Case Study of Social Sciences and Education

Science.gov (United States)

Owolabi, Sola; Idowu, Oluwafemi A.; Okocha, Foluke; Ogundare, Atinuke Omotayo

2016-01-01

The study evaluated utilization of electronic information resources by undergraduates in the Faculties of Education and the Social Sciences in University of Ibadan. The study adopted a descriptive survey design with a study population of 1872 undergraduates in the Faculties of Education and the Social Sciences in University of Ibadan, from which a…

ACCURATE POLARIZATION CALIBRATION AT 800 MHz WITH THE GREEN BANK TELESCOPE

Energy Technology Data Exchange (ETDEWEB)

Liao, Yu-Wei; Chang, Tzu-Ching; Kuo, Cheng-Yu [Institute of Astronomy and Astrophysics, Academia Sinica, 11F of Astro-Math Building, AS/NTU, 1 Roosevelt Road Sec. 4, Taipei 10617, Taiwan (China); Masui, Kiyoshi Wesley [Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, V6T 1Z1 (Canada); Oppermann, Niels; Pen, Ue-Li [Canadian Institute for Theoretical Astrophysics, University of Toronto, 60 St. George Street, Toronto ON, M5S 3H8 (Canada); Peterson, Jeffrey B., E-mail: ywliao@asiaa.sinica.edu.tw [McWilliams Center for Cosmology, Carnegie Mellon University, Department of Physics, 5000 Forbes Avenue, Pittsburgh PA 15213 (United States)

2016-12-20

Polarization leakage of foreground synchrotron emission is a critical issue in H i intensity mapping experiments. While the sought-after H i emission is unpolarized, polarized foregrounds such as Galactic and extragalactic synchrotron radiation, if coupled with instrumental impurity, can mimic or overwhelm the H i signals. In this paper, we present the methodology for polarization calibration at 700–900 MHz, applied on data obtained from the Green Bank Telescope (GBT). We use astrophysical sources, both polarized and unpolarized sources including quasars and pulsars, as calibrators to characterize the polarization leakage and control systematic effects in our GBT H i intensity mapping project. The resulting fractional errors on polarization measurements on boresight are well controlled to within 0.6%–0.8% of their total intensity. The polarized beam patterns are measured by performing spider scans across both polarized quasars and pulsars. A dominant Stokes I to V leakage feature and secondary features of Stokes I to Q and I to U leakages in the 700–900 MHz frequency range are identified. These characterizations are important for separating foreground polarization leakage from the H i 21 cm signal.

ACCURATE POLARIZATION CALIBRATION AT 800 MHz WITH THE GREEN BANK TELESCOPE

International Nuclear Information System (INIS)

Liao, Yu-Wei; Chang, Tzu-Ching; Kuo, Cheng-Yu; Masui, Kiyoshi Wesley; Oppermann, Niels; Pen, Ue-Li; Peterson, Jeffrey B.

2016-01-01

Polarization leakage of foreground synchrotron emission is a critical issue in H i intensity mapping experiments. While the sought-after H i emission is unpolarized, polarized foregrounds such as Galactic and extragalactic synchrotron radiation, if coupled with instrumental impurity, can mimic or overwhelm the H i signals. In this paper, we present the methodology for polarization calibration at 700–900 MHz, applied on data obtained from the Green Bank Telescope (GBT). We use astrophysical sources, both polarized and unpolarized sources including quasars and pulsars, as calibrators to characterize the polarization leakage and control systematic effects in our GBT H i intensity mapping project. The resulting fractional errors on polarization measurements on boresight are well controlled to within 0.6%–0.8% of their total intensity. The polarized beam patterns are measured by performing spider scans across both polarized quasars and pulsars. A dominant Stokes I to V leakage feature and secondary features of Stokes I to Q and I to U leakages in the 700–900 MHz frequency range are identified. These characterizations are important for separating foreground polarization leakage from the H i 21 cm signal.

Prototype studies of a 1 MHz chopper for the KAON Factory

International Nuclear Information System (INIS)

Wait, G.D.; Barnes, M.J.; Bishop, D.; Waters, G.; Figley, C.B.

1991-05-01

A 1.025 MHz (≅ 10 6 discrete pulses/s) beam chopper is required for the injection line into the accumulator ring of the KAON Factory at TRIUMF. The beam chopper will create 108 ns gaps in the 1 GeV/c H - beam to allow enough time for the magnetic field to be established in the kicker magnets in each of the 5 rings. The required deflection of 1 mrad can be achieved with a set of plates 5 cm apart in which the product of voltage difference and plate length is 37.7 kV.m. The 'kick' must have a rise and fall time of less than 39 ns and a flat top of 49 ns on alternate pulses. A novel design concept for a 1 MHz chopper has been developed involving an energy storage system where the electric pulses are stored in a large diameter (10 cm) low loss coaxial cable. Measurements on the performance of a high voltage prototype are presented. Results are encouraging and show that this novel design can be implemented successfully for the KAON Factory. (Author) 11 refs., 6 figs., tab

Shaping the Electronic Library--The UW-Madison Approach.

Science.gov (United States)

Dean, Charles W., Ed.; Frazier, Ken; Pope, Nolan F.; Gorman, Peter C.; Dentinger, Sue; Boston, Jeanne; Phillips, Hugh; Daggett, Steven C.; Lundquist, Mitch; McClung, Mark; Riley, Curran; Allan, Craig; Waugh, David

1998-01-01

This special theme section describes the University of Wisconsin-Madison's experience building its Electronic Library. Highlights include integrating resources and services; the administrative framework; the public electronic library, including electronic publishing capability and access to World Wide Web-based and other electronic resources;…

Physics design of a 10 MeV, 6 kW travelling wave electron linac

Indian Academy of Sciences (India)

We present the physics design of a 10 MeV, 6 kW S-band (2856 MHz) electron linear accelerator (linac), which has been recently built and successfully operated at Raja Ramanna Centre for Advanced Technology, Indore. The accelerating structure is a 2 π / 3 mode constant impedance travelling wave structure, which ...

Effect of 2 MHz ultrasound irradiation on Pisum sativum roots

International Nuclear Information System (INIS)

Miller, M.W.; Voorhees, S.M.; Carstensen, E.L.; Kaufman, G.E.

1976-01-01

The effect of 2 MHz ultrasound at intensity levels from 2.5 to 22 W/cm 2 on the growth rate and mitotic index of Pisum sativum roots was studied. The ultrasound produced an immediate reduction in the growth rate on the first postexposure day, followed by a gradual recovery to the control value. Ultrasound reduced the root meristem mitotic index. Intensity- and time-dependent relations were found for the growth rate and mitotic index reductions

Spectroscopy of radio sources from the Parkes 2700 MHz survey

International Nuclear Information System (INIS)

Thompson, D.J.; Djorgovski, S.; De Carvalho, R.

1990-01-01

The results of long-slit CCD spectroscopy on 37 objects from the Parkes 2700 MHz survey are presented, with data for an additional two companion objects. Eight of the objects are quasars, six more are AGNs, and five more are radio galaxies. Seventeen of the objects observed are stars and, thus, probable misidentifications. Three objects show featureless spectra and are identified as possible BL Lac objects. Spectra are presented for a total of 20 objects. 20 refs

Observation of solar radio bursts using swept-frequency radiospectrograph in 20 - 40 MHz band

International Nuclear Information System (INIS)

Aoyama, Takashi; Oya, Hiroshi.

1987-01-01

A new station for the observation of solar decametric radio bursts has been developed at Miyagi Vocational Training College in Tsukidate, Miyagi, Japan. Using the swept frequency radiospectrograph covering a frequency range from 20 MHz to 40 MHz within 200 msec, with bandwidth of 30 kHz, the radio outbursts from the sun have been currently monitored with colored dynamic spectrum display. After July 1982, successful observations provide the data which include all types of solar radio bursts such as type I, II, III, IV and V in the decametric wavelength range. In addition to these typical radio bursts, rising tone bursts with fast drift rate followed by strong type III bursts and a series of bursts repeating rising and falling tone bursts with slow drift rate have been observed. (author)

Microfluidic stretchable RF electronics.

Science.gov (United States)

Cheng, Shi; Wu, Zhigang

2010-12-07

Stretchable electronics is a revolutionary technology that will potentially create a world of radically different electronic devices and systems that open up an entirely new spectrum of possibilities. This article proposes a microfluidic based solution for stretchable radio frequency (RF) electronics, using hybrid integration of active circuits assembled on flex foils and liquid alloy passive structures embedded in elastic substrates, e.g. polydimethylsiloxane (PDMS). This concept was employed to implement a 900 MHz stretchable RF radiation sensor, consisting of a large area elastic antenna and a cluster of conventional rigid components for RF power detection. The integrated radiation sensor except the power supply was fully embedded in a thin elastomeric substrate. Good electrical performance of the standalone stretchable antenna as well as the RF power detection sub-module was verified by experiments. The sensor successfully detected the RF radiation over 5 m distance in the system demonstration. Experiments on two-dimensional (2D) stretching up to 15%, folding and twisting of the demonstrated sensor were also carried out. Despite the integrated device was severely deformed, no failure in RF radiation sensing was observed in the tests. This technique illuminates a promising route of realizing stretchable and foldable large area integrated RF electronics that are of great interest to a variety of applications like wearable computing, health monitoring, medical diagnostics, and curvilinear electronics.

Controlling user access to electronic resources without password

Science.gov (United States)

Smith, Fred Hewitt

2017-08-22

Described herein are devices and techniques for remotely controlling user access to a restricted computer resource. The process includes obtaining an image from a communication device of a user. An individual and a landmark are identified within the image. Determinations are made that the individual is the user and that the landmark is a predetermined landmark. Access to a restricted computing resource is granted based on the determining that the individual is the user and that the landmark is the predetermined landmark. Other embodiments are disclosed.

The use of quality benchmarking in assessing web resources for the dermatology virtual branch library of the National electronic Library for Health (NeLH).

Science.gov (United States)

Kamel Boulos, M N; Roudsari, A V; Gordon, C; Muir Gray, J A

2001-01-01

In 1998, the U.K. National Health Service Information for Health Strategy proposed the implementation of a National electronic Library for Health to provide clinicians, healthcare managers and planners, patients and the public with easy, round the clock access to high quality, up-to-date electronic information on health and healthcare. The Virtual Branch Libraries are among the most important components of the National electronic Library for Health. They aim at creating online knowledge based communities, each concerned with some specific clinical and other health-related topics. This study is about the envisaged Dermatology Virtual Branch Libraries of the National electronic Library for Health. It aims at selecting suitable dermatology Web resources for inclusion in the forthcoming Virtual Branch Libraries after establishing preliminary quality benchmarking rules for this task. Psoriasis, being a common dermatological condition, has been chosen as a starting point. Because quality is a principal concern of the National electronic Library for Health, the study includes a review of the major quality benchmarking systems available today for assessing health-related Web sites. The methodology of developing a quality benchmarking system has been also reviewed. Aided by metasearch Web tools, candidate resources were hand-selected in light of the reviewed benchmarking systems and specific criteria set by the authors. Over 90 professional and patient-oriented Web resources on psoriasis and dermatology in general are suggested for inclusion in the forthcoming Dermatology Virtual Branch Libraries. The idea of an all-in knowledge-hallmarking instrument for the National electronic Library for Health is also proposed based on the reviewed quality benchmarking systems. Skilled, methodical, organized human reviewing, selection and filtering based on well-defined quality appraisal criteria seems likely to be the key ingredient in the envisaged National electronic Library for

Spectroscopy of QSO candidates from the Jodrell Bank 966 MHz survey

International Nuclear Information System (INIS)

Walsh, D.; Wills, B.J.; Wills, D.

1979-01-01

Forty-two QSO candidates from the Jodrell Bank 966 MHz survey have been observed spectroscopically at McDonald Observatory. Twenty-five are confirmed as QSOs, and redshifts are given for 19 of them. Two objects are compact galaxies, and another probably is; redshifts are given for these. Seven objects are stars. Of the remaining seven objects, six are probably QSOs and one is probably a star. (author)

The effects of electromagnetic radiation (2450 MHz wireless devices) on the heart and blood tissue: role of melatonin.

Science.gov (United States)

Gumral, N; Saygin, M; Asci, H; Uguz, A C; Celik, O; Doguc, D K; Savas, H B; Comlekci, S

2016-01-01

This study was designed to investigate the effects of 2450 MHz EMR on the heart and blood in rat and possible ameliorating effects of melatonin. Thirty-two female Wistar Albino rats were randomly grouped (by eight in each group) as follows:  Group I: cage-control group (dimethysulfoxide (DMSO), 10mg/kg/day i.p. without stress and EMR. Group II: sham-control rats stayed in restrainer without EMR and DMSO (10mg/kg/day i.p.). Group III: rats exposed to 2450 MHz EMR. Group IV: treated group rats exposed to 2450 MHz EMR+melatonin (MLT) (10mg/kg/day i.p.). In the blood tissue, there was no significant difference between the groups in respect of erythrocytes GSH, GSH-Px activity, plasma LP level and vitamin A concentration (p > 0.05). However, in the Group IV, erythrocytes' LP levels (p < 0.05) were observed to be significantly decreased while plasma vitamin C, and vitamin E concentrations (p < 0.05) were found to be increased when compared to Group III. In the heart tissues, MDA and NO levels significantly increased in group III compared with groups I and II (p < 0.05). Contrary to these oxidant levels, CAT and SOD enzyme activities decreased significantly in group III compared with groups I and II (p 0.05). Besides, MLT treatment lowered the MDA and NO levels compared with group III. In conclusion, these results demonstrated that contrary to its effect on the heart, the wireless (2450 MHz) devices cause slight oxidative-antioxidative changes in the blood of rats, and a moderate melatonin supplementation may play an important role in the antioxidant system (plasma vitamin C and vitamin E). However, further investigations are required to clarify the mechanism of action of the applied 2450 MHz EMR exposure (Tab. 3, Fig. 1, Ref. 49).

There is a Relationship between Resource Expenditures and Reference Transactions in Academic Libraries. A Review of: Dubnjakovic, A. (2012. Electronic resource expenditure and the decline in reference transaction statistics in academic libraries. Journal of Academic Librarianship, 38(2, 94-100. doi:10.1016/j.acalib.2012.01.001

Directory of Open Access Journals (Sweden)

Annie M. Hughes

2013-03-01

Full Text Available Objective – To provide an analysis of the impact of expenditures on electronic resourcesand gate counts on the increase or decrease in reference transactions.Design – Analysis of results of existing survey data from the National Center for Educational Statistics (NCES 2006 Academic Library Survey(ALS.Setting – Academic libraries in the United States.Subjects – 3925 academic library respondents.Methods – The author chose to use survey data collected from the 2006 ALS conducted bythe NCES. The survey included data on various topics related to academic libraries, but in the case of this study, the author chose to analyze three of the 193 variables included. The three variables: electronic books expenditure, computer hardware and software, and expenditures on bibliographic utilities, were combined into one variable called electronic resource expenditure. Gate counts were also considered as a variable. Electronic resource expenditure was also split as a variable into three groups: low, medium, and high. Multiple regression analysis and general linear modeling, along with tests of reliability, were employed. Main Results – The author determined that low, medium, and high spenders with regard to electronic resources exhibited differences in gate counts, and gate counts have an effect on reference transactions in any given week. Gate counts tend to not have much of an effect on reference transactions for the higher spenders, and higher spenders tend to have a higher number of reference transactions overall. Low spenders have lower gate counts and also a lower amount of reference transactions.Conclusion – The findings from this study show that academic libraries spending more on electronic resources also tend to have an increase with regard to reference transactions. The author also concludes that library spaces are no longer the determining factor with regard to number of reference transactions. Spending more on electronic resources is

Interplanetary scintillation observations of an unbiased sample of 90 Ooty occultation radio sources at 326.5 MHz

International Nuclear Information System (INIS)

Banhatti, D.G.; Ananthakrishnan, S.

1989-01-01

We present 327-MHz interplanetary scintillation (IPS) observations of an unbiased sample of 90 extragalactic radio sources selected from the ninth Ooty lunar occultation list. The sources are brighter than 0.75 Jy at 327 MHz and lie outside the galactic plane. We derive values, the fraction of scintillating flux density, and the equivalent Gaussian diameter for the scintillating structure. Various correlations are found between the observed parameters. In particular, the scintillating component weakens and broadens with increasing largest angular size, and stronger scintillators have more compact scintillating components. (author)

Readout Electronics Upgrades of the ATLAS Liquid Argon Calorimeter

CERN Document Server

Anelli, Christopher Ryan; The ATLAS collaboration

2018-01-01

The high-luminosity LHC will provide 5-7 times higher luminosites than the orignal design. An improved readout system of the ATLAS Liquid Argon Calorimeter is needed to readout the 182,500 calorimeter cells at 40 MHz with 16 bit dynamic range in these conditions. Low-noise, low-power, radiation-tolerant and high-bandwidth electronics components are being developed in 65 and 130 nm CMOS technologies. First prototypes of the front-end electronics components show good promise to match the stringent specifications. The off-detector electronics will make use of FPGAs connected through high-speed links to perform energy reconstruction, data reduction and buffering. Results of tests of the first prototypes of front-end components will be presented, along with design studies on the performance of the off-detector readout system.

Electronic resources access and usage among the postgraduates of ...

African Journals Online (AJOL)

... and usage among the postgraduates of a Nigerian University of Technology. ... faced by postgraduates in using e-resources include takes too much time to find, ... Resources, Access, Use, Postgraduat, Students, University, Technology, Nigeria ... By Country · List All Titles · Free To Read Titles This Journal is Open Access.

Laser sources for polarized electron beams in cw and pulsed accelerators

CERN Document Server

Hatziefremidis, A; Fraser, D; Avramopoulos, H

1999-01-01

We report the characterization of a high power, high repetition rate, mode-locked laser system to be used in continuous wave and pulsed electron accelerators for the generation of polarized electron beams. The system comprises of an external cavity diode laser and a harmonically mode-locked Ti:Sapphire oscillator and it can provide up to 3.4 W average power, with a corresponding pulse energy exceeding 1 nJ at 2856 MHz repetition rate. The system is tunable between 770-785 and 815-835 nm with two sets of diodes for the external cavity diode laser. (author)

30 MHz radar observations of artificial E region field-aligned plasma irregularities

Directory of Open Access Journals (Sweden)

D. L. Hysell

2008-02-01

Full Text Available Artificial E region field aligned irregularities (FAIs have been observed during heating experiments at the HAARP facility using a new 30 MHz coherent scatter radar imager deployed near Homer, Alaska. Irregularities were observed during brief experiments on three quiet days in July and August, 2007, when the daytime E region critical frequency was close to 3 MHz. Irregularities were consistently generated and detected during experiments with O-mode HF pumping on zenith with a 1-min on, 1-min off CW modulation. The scattering cross sections, rise, and fall times of the echoes were observed as well as their spectral properties. Results were found to be mainly in agreement with observations from other mid- and high-latitude sites with some discrepancies. Radar images of the irregularity-filled volume on one case exhibited clear variations in backscatter power and Doppler shift across the volume. The images furthermore show the emergence of a small irregularity-filled region to the south southwest of the main region in the approximate direction of magnetic zenith.

Multi-MHz micro-electro-mechanical sensors for atomic force microscopy

Energy Technology Data Exchange (ETDEWEB)

Legrand, Bernard, E-mail: bernard.legrand@laas.fr [LAAS-CNRS, Université de Toulouse, CNRS, 7 avenue du colonel Roche, F-31400 Toulouse (France); Salvetat, Jean-Paul [CRPP, 115 avenue Schweitzer, F-33600 Pessac (France); Walter, Benjamin; Faucher, Marc; Théron, Didier [IEMN, avenue Henri Poincaré, F-59652 Villeneuve d’Ascq (France); Aimé, Jean-Pierre [CBMN, allée Geoffroy Saint Hilaire, Bât. B14, F-33600 Pessac (France)

2017-04-15

Silicon ring-shaped micro-electro-mechanical resonators have been fabricated and used as probes for dynamic atomic force microscopy (AFM) experiments. They offer resotnance frequency above 10 MHz, which is notably greater than that of usual cantilevers and quartz-based AFM probes. On-chip electrical actuation and readout of the tip oscillation are obtained by means of built-in capacitive transducers. Displacement and force resolutions have been determined from noise analysis at 1.5 fm/√Hz and 0.4 pN/√Hz, respectively. Despite the high effective stiffness of the probes, the tip-surface interaction force is kept below 1 nN by using vibration amplitude significantly below 100 pm and setpoint close to the free vibration conditions. Imaging capabilities in amplitude- and frequency-modulation AFM modes have been demonstrated on block copolymer surfaces. Z-spectroscopy experiments revealed that the tip is vibrating in permanent contact with the viscoelastic material, with a pinned contact line. Results are compared to those obtained with commercial AFM cantilevers driven at large amplitudes (>10 nm). - Highlights: • Silicon MEMS resonators are used as AFM probes above 10 MHz. • Integrated capacitive transducers drive and sense sub-nanometer tip oscillation. • Force resolution is below 1 pN/√Hz. • Block copolymer surface is imaged using AM and FM AFM modes. • Probes are operated at small vibration amplitude in permanent viscoelastic contact.

Multi-MHz micro-electro-mechanical sensors for atomic force microscopy

International Nuclear Information System (INIS)

Legrand, Bernard; Salvetat, Jean-Paul; Walter, Benjamin; Faucher, Marc; Théron, Didier; Aimé, Jean-Pierre

2017-01-01

Silicon ring-shaped micro-electro-mechanical resonators have been fabricated and used as probes for dynamic atomic force microscopy (AFM) experiments. They offer resotnance frequency above 10 MHz, which is notably greater than that of usual cantilevers and quartz-based AFM probes. On-chip electrical actuation and readout of the tip oscillation are obtained by means of built-in capacitive transducers. Displacement and force resolutions have been determined from noise analysis at 1.5 fm/√Hz and 0.4 pN/√Hz, respectively. Despite the high effective stiffness of the probes, the tip-surface interaction force is kept below 1 nN by using vibration amplitude significantly below 100 pm and setpoint close to the free vibration conditions. Imaging capabilities in amplitude- and frequency-modulation AFM modes have been demonstrated on block copolymer surfaces. Z-spectroscopy experiments revealed that the tip is vibrating in permanent contact with the viscoelastic material, with a pinned contact line. Results are compared to those obtained with commercial AFM cantilevers driven at large amplitudes (>10 nm). - Highlights: • Silicon MEMS resonators are used as AFM probes above 10 MHz. • Integrated capacitive transducers drive and sense sub-nanometer tip oscillation. • Force resolution is below 1 pN/√Hz. • Block copolymer surface is imaged using AM and FM AFM modes. • Probes are operated at small vibration amplitude in permanent viscoelastic contact.

State-of-the-Art Electron Guns and Injector Designs for Energy Recovery Linacs (ERL)

CERN Document Server

Todd, Alan; Ben-Zvi, Ilan; Benson, Stephen V; Blüm, Hans; Burrill, Andrew; Calaga, Rama; Cameron, Peter; Campisi, Isidoro E; Chang, Xiangyun; Christina, Vincent; Cole, Michael; Colestock, Patrick L; Daly, Edward; Douglas, David; Dylla, Fred H; Falletta, Michael; Hahn, Harald; Hernandez-Garcia, Carlos; Hogan, John; Holmes, Douglas; Janssen, Dietmar; Kayran, Dmitry; Kelley, John P; Kewisch, Jorg; Kneisel, Peter; Kurennoy, Sergey; Lewellen, John W; Litvinenko, Vladimir N; Mammosser, John; McIntyre, Gary; Neil, George R; Nguyen, Dinh C; Nicoletti, Tony; Peterson, Ed; Phillips, Larry; Preble, Joseph P; Rank, Jim; Rao, Triveni; Rathke, John; Reass, William; Rees, Daniel; Rimmer, Robert; Rode, Claus; Russell, Steven; Scaduto, Joseph; Schrage, Dale L; Schultheiss, Tom; Sekutowicz, Jacek; Siggins, Tim; Warren Funk, L; Whitlach, Timothy; Wiseman, Mark; Wong, Robert; Wood, Richard L; Wu, Kuo-Chen; Young, Lloyd M; Zaltsman, Alex; Zhao, Yongxiang

2005-01-01

A key technology issue of ERL devices for high-power free-electron laser (FEL) and 4th generation light sources is the demonstration of reliable, high-brightness, high-power injector operation. Ongoing programs that target up to 1 Ampere injector performance at emittance values consistent with the requirements of these applications are described. We consider that there are three possible approaches that could deliver the required performance. The first is a DC photocathode gun and superconducting RF (SRF) booster cryomodule. Such a 750 MHz device is being integrated and will be tested up to 100 mA at the Thomas Jefferson National Accelerator Facility beginning in 2007. The second approach is a high-current normal-conducting RF photoinjector. A 700 MHz gun will undergo thermal test in 2006 at the Los Alamos National Laboratory, which, if successful, when equipped with a suitable cathode, would be capable of 1 Ampere operation. The last option is an SRF gun. A half-cell 703 MHz SRF gun capable of delivering 1.0...

New high power 200 MHz RF system for the LANSCE drift tube linac

International Nuclear Information System (INIS)

Lyles, J.; Friedrichs, C.; Lynch, M.

1998-01-01

The Los Alamos Neutron Science Center (LANSCE) linac provides an 800 MeV direct H + proton beam, and injects H - to the upgraded proton storage ring for charge accumulation for the Short Pulse Spallation Source. Accelerating these interlaced beams requires high average power from the 201.25 MHz drift tube linac (DTL) RF system. Three power amplifiers have operated at up to three Megawatts with 12% duty factor. The total number of electron power tubes in the RF amplifiers and their modulators has been reduced from fifty-two to twenty-four. The plant continues to utilize the original design of a tetrode driving a super power triode. Further increases in the linac duty factor are limited, in part, by the maximum dissipation ratings of the triodes. A description of the system modifications proposed to overcome these limitations includes new power amplifiers using low-level RF modulation for tank field control. The first high power Diacrode reg-sign is being delivered and a new amplifier cavity is being designed. With only eight power tubes, the new system will deliver both peak power and high duty factor, with lower mains power and cooling requirements. The remaining components needed for the new RF system will be discussed

Electronic Safety Resource Tools -- Supporting Hydrogen and Fuel Cell Commercialization

Energy Technology Data Exchange (ETDEWEB)

Barilo, Nick F.

2014-09-29

The Pacific Northwest National Laboratory (PNNL) Hydrogen Safety Program conducted a planning session in Los Angeles, CA on April 1, 2014 to consider what electronic safety tools would benefit the next phase of hydrogen and fuel cell commercialization. A diverse, 20-person team led by an experienced facilitator considered the question as it applied to the eight most relevant user groups. The results and subsequent evaluation activities revealed several possible resource tools that could greatly benefit users. The tool identified as having the greatest potential for impact is a hydrogen safety portal, which can be the central location for integrating and disseminating safety information (including most of the tools identified in this report). Such a tool can provide credible and reliable information from a trustworthy source. Other impactful tools identified include a codes and standards wizard to guide users through a series of questions relating to application and specific features of the requirements; a scenario-based virtual reality training for first responders; peer networking tools to bring users from focused groups together to discuss and collaborate on hydrogen safety issues; and a focused tool for training inspectors. Table ES.1 provides results of the planning session, including proposed new tools and changes to existing tools.

Development of disposable membrane hydrophones for a frequency range from 1MHz to 10MHz.

Science.gov (United States)

Lee, Jae-Wan; Ohm, Won-Suk; Kim, Yong-Tae

2017-11-01

A method for fabricating disposable membrane hydrophones is presented. The disposable hydrophones are intended for onetime use in such damaging environments as chemically contaminating fluids and high-amplitude (peak amplitude ∼100MPa) shock wave fields, where the use of commercial membrane hydrophones is not recommended. Fabrication of a hydrophone is done using only off-the-shelf components and hand tools, which translates into ease of fabrication and orders-of-magnitude reduction in unit cost. In particular, poling and sputtering, the two processes that are chiefly responsible for the cost and difficulty associated with the conventional fabrication method, are replaced with the use of pre-poled polyvinylidene fluoride (PVDF) films and polyethylene terephthalate (PET)-coated aluminum foils, respectively. Despite the seemingly crude construction, these disposable hydrophones can exhibit voltage sensitivity response that compares favorably with that of commercial hydrophones. For example, one prototype having a 2mm×2mm active element shows the end-of-cable voltage sensitivity of -270 (±1.9) dB re 1V/μPa over the frequency range of 1-10MHz. Copyright © 2017 Elsevier B.V. All rights reserved.

915-MHz Radar Wind Profiler (915RWP) Handbook

Energy Technology Data Exchange (ETDEWEB)

Coulter, R

2005-01-01

The 915 MHz radar wind profiler/radio acoustic sounding system (RWP/RASS) measures wind profiles and backscattered signal strength between (nominally) 0.1 km and 5 km and virtual temperature profiles between 0.1 km and 2.5 km. It operates by transmitting electromagnetic energy into the atmosphere and measuring the strength and frequency of backscattered energy. Virtual temperatures are recovered by transmitting an acoustic signal vertically and measuring the electromagnetic energy scattered from the acoustic wavefront. Because the propagation speed of the acoustic wave is proportional to the square root of the virtual temperature of the air, the virtual temperature can be recovered by measuring the Doppler shift of the scattered electromagnetic wave.

Optimized 425MHz passive wireless magnetic field sensor

KAUST Repository

Li, Bodong

2014-06-01

A passive, magnetic field sensor consisting of a 425 MHz surface acoustic wave device loaded with a giant magnetoimpedance element is developed. The GMI element with a multilayer structure composed of Ni80Fe 20/Cu/Ni80Fe20, is fabricated on a 128° Y-X cut LiNbO3 LiNbO3 substrate. The integrated sensor is characterized with a network analyzer through an S-parameter measurement. Upon the application of a magnetic field, a maximum magnitude change and phase shift of 7.8 dB and 27 degree, respectively, are observed. Within the linear region, the magnetic sensitivity is 1.6 dB/Oe and 5 deg/Oe. © 2014 IEEE.

Design of 57.5 MHz CW RFQ structure for the Rare Isotope ...

Indian Academy of Sciences (India)

The Rare Isotope Accelerator (RIA) facility includes a driver LINAC for production of 400 kW CW heavy-ion beams. The initial acceleration of heavy ions delivered from an ECR ion source can be effectively performed by a 57.5 MHz 4 m long RFQ. The principal specifications of the RFQ are: (1) formation of extremely low ...

Electronics for very high rate tracking detectors

International Nuclear Information System (INIS)

Williams, H.H.; Dressnandt, N.; Ekenberg, T.; Gerds, E.J.; Newcomer, F.M.; Tedja, S.; Van Berg, R.; Van der Speigel, J.

1995-01-01

Results are presented on a system of electronics designed for very high rate tracking detectors at the SSC and LHC. The primary goal was a system for signal detection, time measurement, and readout for the straw tracker for SDC. An integrated circuit incorporating eight channels of amplifier-shaper-discriminator (including detector tail cancellation), and two different integrated circuits for time measurement are described. The performance of tracking measurements up to counting rates of 8 MHz per wire is reported, as well as preliminary results from a baseline restoration circuit. (orig.)

EFFECTIVE ELECTRONIC TUTORIAL

Directory of Open Access Journals (Sweden)

Andrei A. Fedoseev

2014-01-01

Full Text Available The article analyzes effective electronic tutorials creation and application based on the theory of pedagogy. Herewith the issues of necessary electronic tutorial functional, ways of the educational process organization with the use of information and communication technologies and the logistics of electronic educational resources are touched upon. 

Electron imaging with Medipix2 hybrid pixel detector

CERN Document Server

McMullan, G; Chen, S; Henderson, R; Llopart, X; Summerfield, C; Tlustos, L; Faruqi, A R

2007-01-01

The electron imaging performance of Medipix2 is described. Medipix2 is a hybrid pixel detector composed of two layers. It has a sensor layer and a layer of readout electronics, in which each 55 μm×55 μm pixel has upper and lower energy discrimination and MHz rate counting. The sensor layer consists of a 300 μm slab of pixellated monolithic silicon and this is bonded to the readout chip. Experimental measurement of the detective quantum efficiency, DQE(0) at 120 keV shows that it can reach 85% independent of electron exposure, since the detector has zero noise, and the DQE(Nyquist) can reach 35% of that expected for a perfect detector (4/π2). Experimental measurement of the modulation transfer function (MTF) at Nyquist resolution for 120 keV electrons using a 60 keV lower energy threshold, yields a value that is 50% of that expected for a perfect detector (2/π). Finally, Monte Carlo simulations of electron tracks and energy deposited in adjacent pixels have been performed and used to calculate expected v...

Accuracy of the manufacture of electrodes for a 433 MHz RFQ

International Nuclear Information System (INIS)

Budtov, A.A.; Gruzdev, V.A.; Petrov, V.I.; Svistunov, Y.A.; Marinin, G.V.

2006-01-01

Analysis of the dependence of the accuracy of the interelectrode distance on the accuracy of electrode surface machining for a 433 MHz four-segment radio-frequency quadrupole (RFQ) resonator is reported. The aim of the research was to determine the requirements for measurement methods and machining of the RFQ segments. Analysis of particle capture into acceleration as a function of the electrode modulation amplitude at the RFQ input is discussed

Accuracy of the manufacture of electrodes for a 433 MHz RFQ

Energy Technology Data Exchange (ETDEWEB)

Budtov, A.A. [D.V. Efremov Scientific Research Institute of Electrophysical Apparatus (NIIEFA), Scientific Production Complex of Linear Accelerators and Cyclotrons (NPK LUTS), 196641 St. Petersburg (Russian Federation); Gruzdev, V.A. [D.V. Efremov Scientific Research Institute of Electrophysical Apparatus (NIIEFA), Scientific Production Complex of Linear Accelerators and Cyclotrons (NPK LUTS), 196641 St. Petersburg (Russian Federation); Petrov, V.I. [D.V. Efremov Scientific Research Institute of Electrophysical Apparatus (NIIEFA), Scientific Production Complex of Linear Accelerators and Cyclotrons (NPK LUTS), 196641 St. Petersburg (Russian Federation)]. E-mail: npkluts@niiefa.spb.su; Svistunov, Y.A. [D.V. Efremov Scientific Research Institute of Electrophysical Apparatus (NIIEFA), Scientific Production Complex of Linear Accelerators and Cyclotrons (NPK LUTS), 196641 St. Petersburg (Russian Federation); Marinin, G.V. [Russian Technologies Ltd., 195030 St. Peterburg (Russian Federation)

2006-03-01

Analysis of the dependence of the accuracy of the interelectrode distance on the accuracy of electrode surface machining for a 433 MHz four-segment radio-frequency quadrupole (RFQ) resonator is reported. The aim of the research was to determine the requirements for measurement methods and machining of the RFQ segments. Analysis of particle capture into acceleration as a function of the electrode modulation amplitude at the RFQ input is discussed.

Development of ATLAS Liquid Argon Calorimeter Front-end Electronics for the HL-LHC

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00219286; The ATLAS collaboration

2016-01-01

The high-luminosity phase of the Large Hadron Collider will provide 5-7 times greater luminosities than assumed in the original detector design. An improved trigger system requires an upgrade of the readout electronics of the ATLAS Liquid Argon Calorimeter. Concepts for the future readout of the 182,500 calorimeter channels at 40-80 MHz and 16-bit dynamic range and the developments of radiation-tolerant, low-noise, low-power, and high-bandwidth front-end electronic components, including preamplifiers and shapers, 14-bit ADCs, and 10-Gb/s laser diode array drivers, are presented.

Design of spherical electron gun for ultra high frequency, CW power inductive output tube

International Nuclear Information System (INIS)

Kaushik, Meenu; Joshi, L. M.

2016-01-01

Inductive Output Tube (IOT) is an amplifier that usually operates in UHF range. It is an electron tube whose basic structure is similar to conventional vacuum devices. This device is widely used in broadcast applications but is now being explored for scientific applications also specifically, particle accelerators and fusion plasma heating purposes. The paper describes the design approach of a spherical gridded electron gun of a 500 MHz, 100 kW CW power IOT. The electron gun structure has been simulated and optimized for operating voltage and current of 40kV and 3.5 A respectively. The electromagnetic analysis of this spherical electron gun has been carried out in CST and TRAK codes.

Design of spherical electron gun for ultra high frequency, CW power inductive output tube

Energy Technology Data Exchange (ETDEWEB)

Kaushik, Meenu, E-mail: mkceeri@gmail.com; Joshi, L. M., E-mail: lmj1953@gmail.com [Microwave Tubes Division, CSIR-Central Electronics Engineering Research Institute (CEERI), Pilani, Rajasthan (India); Academy of Scientific and Innovative Research (AcSIR), New Delhi (India)

2016-03-09

Inductive Output Tube (IOT) is an amplifier that usually operates in UHF range. It is an electron tube whose basic structure is similar to conventional vacuum devices. This device is widely used in broadcast applications but is now being explored for scientific applications also specifically, particle accelerators and fusion plasma heating purposes. The paper describes the design approach of a spherical gridded electron gun of a 500 MHz, 100 kW CW power IOT. The electron gun structure has been simulated and optimized for operating voltage and current of 40kV and 3.5 A respectively. The electromagnetic analysis of this spherical electron gun has been carried out in CST and TRAK codes.

A simple-architecture fibered transmission system for dissemination of high stability 100 MHz signals

Science.gov (United States)

Bakir, A.; Rocher, C.; Maréchal, B.; Bigler, E.; Boudot, R.; Kersalé, Y.; Millo, J.

2018-05-01

We report on the development of a simple-architecture fiber-based frequency distribution system used to transfer high frequency stability 100 MHz signals. This work is focused on the emitter and the receiver performances that allow the transmission of the radio-frequency signal over an optical fiber. The system exhibits a residual fractional frequency stability of 1 × 10-14 at 1 s integration time and in the low 10-16 range after 100 s. These performances are suitable to transfer the signal of frequency references such as those of a state-of-the-art hydrogen maser without any phase noise compensation scheme. As an application, we demonstrate the dissemination of such a signal through a 100 m long optical fiber without any degradation. The proposed setup could be easily extended for operating frequencies in the 10 MHz-1 GHz range.

Performance of photocathode rf gun electron accelerators

International Nuclear Information System (INIS)

Ben-Zvi, I.

1993-01-01

In Photo-Injectors (PI) electron guns, electrons are emitted from a photocathode by a short laser pulse and then accelerated by intense rf fields in a resonant cavity. The best known advantage of this technique is the high peak current with a good emittance (high brightness). This is important for short wavelength Free-Electron Lasers and linear colliders. PIs are in operation in many electron accelerator facilities and a large number of new guns are under construction. Some applications have emerged, providing, for example, very high pulse charges. PIs have been operated over a wide range of frequencies, from 144 to 3000 MHz (a 17 GHz gun is being developed). An exciting new possibility is the development of superconducting PIs. A significant body of experimental and theoretical work exists by now, indicating the criticality of the accelerator elements that follow the gun for the preservation of the PI's performance as well as possible avenues of improvements in brightness. Considerable research is being done on the laser and photocathode material of the PI, and improvement is expected in this area

Diffuse radio emission in the Coma cluster and Abell 1367: observations at 430 and 1400 MHz

International Nuclear Information System (INIS)

Hanisch, R.J.

1980-01-01

Two rich clusters of galaxies, Abell 1656 (the Coma cluster) and Abell 1367, have been mapped at both 430 and 1400 MHz with the 305-m telescope at Arecibo. The contribution to the observed radio emission due to known discrete sources has been calculated by convolving interferometrically determined source lists with observed Arecibo beam patterns, and maps of the diffuse radio emission alone have been constructed. Both clusters contain regions of diffuse radio emission, although the source in Coma is larger and much more luminous than the source in Abell 1367. The linear extent of the diffuse emission and its dependence on frequency have been used to study particle propagation rates and modes of diffusion in the intracluster medium. The possible correlations between the diffuse radio emission and x-ray emission in these clusters have been investigated, and it has been found that the observed x-ray luminosities can be accounted for if the intracluster gas is heated through Coulomb interactions with the relativistic electrons responsible for the diffuse radio emission

High Resolution Gamma Ray Spectroscopy at MHz Counting Rates With LaBr3 Scintillators for Fusion Plasma Applications

Science.gov (United States)

Nocente, M.; Tardocchi, M.; Olariu, A.; Olariu, S.; Pereira, R. C.; Chugunov, I. N.; Fernandes, A.; Gin, D. B.; Grosso, G.; Kiptily, V. G.; Neto, A.; Shevelev, A. E.; Silva, M.; Sousa, J.; Gorini, G.

2013-04-01

High resolution γ-ray spectroscopy measurements at MHz counting rates were carried out at nuclear accelerators, combining a LaBr 3(Ce) detector with dedicated hardware and software solutions based on digitization and off-line analysis. Spectra were measured at counting rates up to 4 MHz, with little or no degradation of the energy resolution, adopting a pile up rejection algorithm. The reported results represent a step forward towards the final goal of high resolution γ-ray spectroscopy measurements on a burning plasma device.

Microwave ablation: Results with double 915 MHz antennae in ex vivo bovine Livers

International Nuclear Information System (INIS)

Shi Wenyuan; Liang Ping; Zhu Qiang; Yu Xiaoling; Shao Qiujie; Lu Tong; Wang Yang; Dong Baowei

2011-01-01

Purpose: To investigate the settings for the optimal microwave ablation geometry with the simultaneous application of double 915 MHz antennae in ex vivo bovine livers, so as to provide the technical basis for treating large liver tumor in one ablation session. Materials and methods: MWAs were performed on ex vivo bovine livers by simultaneously application of double 915 MHz internally cooled-shaft antennae. Four power settings (50, 60, 70 and 80 W) were used during MWAs, while application time was fixed at 10 min. Three inter-antenna distances (2.0, 2.5 and 3.0 cm) were used. Diameters and shapes of the coagulation zones were observed on gross specimens. Results: (1) The coagulation shape was related to the inter-antenna distance, which was most spherical at an inter-antenna distance of 2.0 cm. A recess of the coagulation zone was observed at an inter-antenna distances of 2.5 and 3.0 cm. (2) The long-axis and short-axis coagulation diameter enlarged with increasing power output. However, there were no significant differences in the coagulation diameters between 70 and 80 W (P > 0.05). More desirable coagulation geometry could be obtained by simultaneous application of double antennae at 70 W for 10 min with an inter-antenna distance of 2.0 cm, the long-axis and short-axis coagulation diameter were 6.95 ± 0.32 cm and 5.30 ± 0.22 cm, respectively. Conclusion: Simultaneous application of double 915 MHz antennae can generate large coagulation zones with desirable shape which may be advantageous for treating large liver tumor in one ablation session.

Research on backward traveling wave electron linac

International Nuclear Information System (INIS)

Chen Huaibi; Zheng Shuxin; Ding Xiaodong; Lin Yuzheng

1999-01-01

Future electron linacs require high gradient acceleration. The studies on the high shunt impedance backward traveling wave electron linac accelerating structure (BTW) are presented. At first, the characteristics of BTW are researched. The option of mode and optimal design methods of accelerating cavity for BTW are studied. A physical design method for BTW accelerators, including longitudinal and transversal particle dynamics, is given. Based on above studies, a 9 MeV BTW accelerating tube at 3π/4 mode with frequency 2856 MHz for inspecting large container as radiation source at customs is designed, and a comparison with disk-loaded waveguide accelerating tube is made. The result of research leads to the conclusion that backward traveling wave accelerating structure is preferable. Because BTW has higher effective shunt impedance, shorter filling time and more stable operation

SPAD electronics for high-speed quantum communications

Science.gov (United States)

Bienfang, Joshua C.; Restelli, Alessandro; Migdall, Alan

2011-01-01

We discuss high-speed electronics that support the use of single-photon avalanche diodes (SPADs) in gigahertz singlephoton communications systems. For InGaAs/InP SPADs, recent work has demonstrated reduced afterpulsing and count rates approaching 500 MHz can be achieved with gigahertz periodic-gating techniques designed to minimize the total avalanche charge to less than 100 fC. We investigate afterpulsing in this regime and establish a connection to observations using more conventional techniques. For Si SPADs, we report the benefits of improved timing electronics that enhance the temporal resolution of Si SPADs used in a free-space quantum key distribution (QKD) system operating in the GHz regime. We establish that the effects of count-rate fluctuations induced by daytime turbulent scintillation are significantly reduced, benefitting the performance of the QKD system.

Renewable energy resources

DEFF Research Database (Denmark)

Ellabban, Omar S.; Abu-Rub, Haitham A.; Blaabjerg, Frede

2014-01-01

Electric energy security is essential, yet the high cost and limited sources of fossil fuels, in addition to the need to reduce greenhouse gasses emission, have made renewable resources attractive in world energy-based economies. The potential for renewable energy resources is enormous because...... they can, in principle, exponentially exceed the world's energy demand; therefore, these types of resources will have a significant share in the future global energy portfolio, much of which is now concentrating on advancing their pool of renewable energy resources. Accordingly, this paper presents how...... renewable energy resources are currently being used, scientific developments to improve their use, their future prospects, and their deployment. Additionally, the paper represents the impact of power electronics and smart grid technologies that can enable the proportionate share of renewable energy...

Measure of enzymatic activity coincident with 2450 MHz microwave exposure

Energy Technology Data Exchange (ETDEWEB)

Ward, T R; Allis, J W; Elder, J A

1975-09-01

Enzyme preparations were exposed to microwave radiation at 2450 MHz and enzymatic activity was simultaneously monitored spectrophotometrically with a crossed-beam exposure detection system. Enzymes studied were glucose 6-phosphate dehydrogenase from human red blood cells and yeast, adenylate kinase from rat liver mitochondria and rabbit muscle, and rat liver microsomal NADPH cytochrome c reductase. No difference was found between the specific activity at 25/sup 0/C of unirradiated controls and enzyme preparations irradiated at an absorbed dose rate of 42 W/kg.

Preference and Use of Electronic Information and Resources by Blind/Visually Impaired in NCR Libraries in India

Directory of Open Access Journals (Sweden)

Shailendra Kumar

2013-06-01

Full Text Available This paper aims to determine the preference and use of electronic information and resources by blind/visually impaired users in the leading National Capital Region (NCR libraries of India. Survey methodology has been used as the basic research tool for data collection with the help of questionnaires. The 125 in total users surveyed in all the five libraries were selected randomly on the basis of willingness of the users with experience of working in digital environments to participate in the survey. The survey results were tabulated and analyzed with descriptive statistics methods using Excel software and 'Stata version 11'. The findings reveal that ICT have a positive impact in the lives of people with disabilities as it helps them to work independently and increases the level of confidence among them. The Internet is the most preferred medium of access to information among the majority of blind/visually impaired users. The 'Complexity of content available on the net' is found as the major challenge faced during Internet use by blind users of NCR libraries. 'Audio books on CDs/DVDs and DAISY books' are the most preferred electronic resources among the majority of blind/visually impaired users. This study will help the library professionals and organizations/institutions serving people with disabilities to develop effective library services for blind/visually impaired users in the digital environment on the basis of findings on information usage behavior in the study.

Deposition of organosilicone thin film from hexamethyldisiloxane (HMDSO) with 50 kHz/33 MHz dual-frequency atmospheric-pressure plasma jet

Science.gov (United States)

Li, Jiaojiao; Yuan, Qianghua; Chang, Xiaowei; Wang, Yong; Yin, Guiqin; Dong, Chenzhong

2017-04-01

The deposition of organosilicone thin films from hexamethyldisiloxane(HMDSO) by using a dual-frequency (50 kHz/33 MHz) atmospheric-pressure micro-plasma jet with an admixture of a small volume of HMDSO and Ar was investigated. The topography was measured by using scanning electron microscopy. The chemical bond and composition of these films were analyzed by Fourier transform infrared spectroscopy (FTIR) and x-ray photoelectron spectroscopy. The results indicated that the as-deposited film was constituted by silicon, carbon, and oxygen elements, and FTIR suggested the films are organosilicon with the organic component (-CH x ) and hydroxyl functional group(-OH) connected to the Si-O-Si backbone. Thin-film hardness was recorded by an MH-5-VM Digital Micro-Hardness Tester. Radio frequency power had a strong impact on film hardness and the hardness increased with increasing power.

A 10.7 MHz CMOS SC radio IF filter using orthogonal hardware modulation

NARCIS (Netherlands)

Quinn, P.J.; Hartingsveldt, van K.; Roermund, van A.H.M.

2000-01-01

FM radio receivers require an IF filter for channel selection, customarily set at an IF center frequency of 10.7 MHz. Up until now, the limitations of integrated radio selectivity filters in terms of power dissipation, dynamic range, and cost are such that it is still required to use an external

A statistical study of faint radio sources at 81.5 MHz

International Nuclear Information System (INIS)

Duffett-Smith, P.J.; Purvis, A.; Hewish, A.

1980-01-01

The method of interplanetary scintillations (IPS) together with the technique of background deflection analysis (P(D)) have been used to determine the mean angular size and the sky density of scintillating radio sources in the range 2 to 3 Jy at 81.5 MHz. It is found that the radio power from a high proportion of the sources in this range comes from one or two components of angular diameter about 0.7 arcsec. (author)

High current precision long pulse electron beam position monitor

CERN Document Server

Nelson, S D; Fessenden, T J; Holmes, C

2000-01-01

Precision high current long pulse electron beam position monitoring has typically experienced problems with high Q sensors, sensors damped to the point of lack of precision, or sensors that interact substantially with any beam halo thus obscuring the desired signal. As part of the effort to develop a multi-axis electron beam transport system using transverse electromagnetic stripline kicker technology, it is necessary to precisely determine the position and extent of long high energy beams for accurate beam position control (6 - 40 MeV, 1 - 4 kA, 2 μs beam pulse, sub millimeter beam position accuracy.) The kicker positioning system utilizes shot-to-shot adjustments for reduction of relatively slow (< 20 MHz) motion of the beam centroid. The electron beams passing through the diagnostic systems have the potential for large halo effects that tend to corrupt position measurements.

Simulation and analysis of secondary emission microwave electron gun

International Nuclear Information System (INIS)

He Wencan; Pei Yuanji; Jin Kai; Wu Congfeng

2001-01-01

The development of high-current, short-duration pulses of electrons has been a challenging problem for many year. Micro-pulse-gun (MPG) is a novel concept that employs the resonant amplification of an electron current by secondary electron emission in a RE cavity. Using the computation code URMEL-T, several kinds of RF cavities under the frequency of 2856 MHz were calculated and optimized, the magnetic and electric field distribution in them were got. Through particle-in-cell (PIC) simulation, the self-bunching process in a MPG was proved, the relationship between the cavity length and selected phase and the relationship between the peak electric field and selected phase were got. With cathode material of high secondary emission coefficient, the MPG can produce high current densities (1132-5303 A/cm 2 ) and short pulses (3.15-10 ps)

Front end readout electronics for the CMS hadron calorimeter

CERN Document Server

Shaw, Terri M

2002-01-01

The front-end electronics for the CMS Hadron Calorimeter provides digitized data at the beam interaction rate of 40 MHz. Analog signals provided by hybrid photodiodes (HPDs) or photomultiplier tubes (PMTs) are digitized and the data is sent off board through serialized fiber optic links running at 1600 Mbps. In order to maximize the input signal, the front-end electronics are housed on the detector in close proximity to the scintillating fibers or phototubes. To fit the electronics into available space, custom crates, backplanes and cooling methods have had to be developed. During the expected ten-year lifetime, the front-end readout electronics will exist in an environment where radiation levels approach 330 rads and the neutron fluence will be 1.3E11 n/cm sup 2. For this reason, the design approach relies heavily upon custom radiation tolerant ASICs. This paper will present the system architecture of the front-end readout crates and describe their results with early prototypes.

Front end readout electronics for the CMS hadron calorimeter

International Nuclear Information System (INIS)

Terri M. Shaw et al.

2002-01-01

The front-end electronics for the CMS Hadron Calorimeter provides digitized data at the beam interaction rate of 40 MHz. Analog signals provided by hybrid photodiodes (HPDs) or photomultiplier tubes (PMTs) are digitized and the data is sent off board through serialized fiber optic links running at 1600 Mbps. In order to maximize the input signal, the front-end electronics are housed on the detector in close proximity to the scintillating fibers or phototubes. To fit the electronics into available space, custom crates, backplanes and cooling methods have had to be developed. During the expected ten-year lifetime, the front-end readout electronics will exist in an environment where radiation levels approach 330 rads and the neutron fluence will be 1.3E11 n/cm 2 . For this reason, the design approach relies heavily upon custom radiation tolerant ASICs. This paper will present the system architecture of the front-end readout crates and describe their results with early prototypes

HIGH-CURRENT ERL-BASED ELECTRON COOLING FOR RHIC

International Nuclear Information System (INIS)

BEN-ZVI, I.

2005-01-01

The design of an electron cooler must take into account both electron beam dynamics issues as well as the electron cooling physics. Research towards high-energy electron cooling of RHIC is in its 3rd year at Brookhaven National Laboratory. The luminosity upgrade of RHIC calls for electron cooling of various stored ion beams, such as 100 GeV/A gold ions at collision energies. The necessary electron energy of 54 MeV is clearly out of reach for DC accelerator system of any kind. The high energy also necessitates a bunched beam, with a high electron bunch charge, low emittance and small energy spread. The Collider-Accelerator Department adopted the Energy Recovery Linac (ERL) for generating the high-current, high-energy and high-quality electron beam. The RHIC electron cooler ERL will use four Superconducting RF (SRF) 5-cell cavities, designed to operate at ampere-class average currents with high bunch charges. The electron source will be a superconducting, 705.75 MHz laser-photocathode RF gun, followed up by a superconducting Energy Recovery Linac (ERL). An R and D ERL is under construction to demonstrate the ERL at the unprecedented average current of 0.5 amperes. Beam dynamics performance and luminosity enhancement are described for the case of magnetized and non-magnetized electron cooling of RHIC

5 MeV 300 kW electron accelerator project

International Nuclear Information System (INIS)

Auslender, V.L.; Cheskidov, V.G.; Gornakov, I.V.

2004-01-01

The paper presents a project of a high power linear accelerator for industrial applications. The accelerator has a modular structure and consists of the chain of accelerating cavities connected by the axis-located coupling cavities with coupling slots in the common walls. Main parameters of the accelerator are: operating frequency of 176 MHz, electron energy of up to 5 MeV, average beam power of 300 kW. The required RF pulse power can be supplied by the TH628 diacrode

Emission characteristics of 6.78-MHz radio-frequency glow discharge plasma in a pulsed mode

Science.gov (United States)

Zhang, Xinyue; Wagatsuma, Kazuaki

2017-07-01

This paper investigated Boltzmann plots for both atomic and ionic emission lines of iron in an argon glow discharge plasma driven by 6.78-MHz radio-frequency (RF) voltage in a pulsed operation, in order to discuss how the excitation/ionization process was affected by the pulsation. For this purpose, a pulse frequency as well as a duty ratio of the pulsed RF voltage was selected as the experimenter parameters. A Grimm-style radiation source was employed at a forward RF power of 70 W and at an argon pressures of 670 Pa. The Boltzmann plot for low-lying excited levels of iron atom was on a linear relationship, which was probably attributed to thermal collisions with ultimate electrons in the negative glow region; in this case, the excitation temperature was obtained in a narrow range of 3300-3400 K, which was hardly affected by the duty ratio as well as the pulse frequency of the pulsed RF glow discharge plasma. This observation suggested that the RF plasma could be supported by a self-stabilized negative glow region, where the kinetic energy distribution of the electrons would be changed to a lesser extent. Additional non-thermal excitation processes, such as a Penning-type collision and a charge-transfer collision, led to deviations (overpopulation) of particular energy levels of iron atom or iron ion from the normal Boltzmann distribution. However, their contributions to the overall excitation/ionization were not altered so greatly, when the pulse frequency or the duty ratio was varied in the pulsed RF glow discharge plasma.

Channel processor in 2D cluster finding algorithm for high energy physics application

International Nuclear Information System (INIS)

Paul, Rourab; Chakrabarti, Amlan; Mitra, Jubin; Khan, Shuaib A.; Nayak, Tapan; Mukherjee, Sanjoy

2016-01-01

In a Large Ion Collider Experiment (ALICE) at CERN 1 TB/s (approximately) data comes from front end electronics. Previously, we had 1 GBT link operated with a cluster clock frequencies of 133 MHz and 320 MHz in Run 1 and Run 2 respectively. The cluster algorithm proposed in Run 1 and 2 could not work in Run 3 as the data speed increased almost 20 times. Older version cluster algorithm receives data sequentially as a stream. It has 2 main sub processes - Channel Processor, Merging process. The initial step of channel processor finds a peak Q max and sums up pads (sensors) data from -2 time bin to +2 time bin in the time direction. The computed value stores in a register named cluster fragment data (cfd o ). The merging process merges cfd o in pad direction. The data streams in Run 2 comes sequentially, which processed by the channel processor and merging block in a sequential manner with very less resource over head. In Run 3 data comes parallely, 1600 data from 1600 pads of a single time instant comes at each 200 ns interval (5 MHz) which is very challenging to process in the budgeted resource platform of Arria 10 FPGA hardware with 250 to 320 MHz cluster clock

Development of vertical electropolishing process applied on 1300 and 704 MHz superconducting niobium resonators

Directory of Open Access Journals (Sweden)

F. Eozénou

2014-08-01

Full Text Available An advanced setup for vertical electropolishing of superconducting radio-frequency niobium elliptical cavities has been installed at CEA Saclay. Cavities are vertically electropolished with circulating standard HF-HF-H_{2}SO_{4} electrolytes. Parameters such as voltage, cathode shape, acid flow, and temperature have been investigated. A low voltage (between 6 and 10 V depending on the cavity geometry, a high acid flow (25  L/min, and a low acid temperature (20° C are considered as promising parameters. Such a recipe has been tested on single-cell and nine-cell International Linear Collider (ILC as well as 704 MHz five-cell Super Proton Linac (SPL cavities. Single-cell cavities showed similar performances at 1.6 K being either vertically or horizontally electropolished. The applied baking process provides similar benefit. An asymmetric removal is observed with faster removal in the upper half-cells. Multicell cavities (nine-cell ILC and five-cell SPL cavities exhibit a standard Q_{0} value at low and medium accelerating fields though limited by power losses due to field emitted electrons.

Complex Impedance of Fast Optical Transition Edge Sensors up to 30 MHz

Science.gov (United States)

Hattori, K.; Kobayashi, R.; Numata, T.; Inoue, S.; Fukuda, D.

2018-03-01

Optical transition edge sensors (TESs) are characterized by a very fast response, of the order of μs, which is 10^3 times faster than TESs for X-ray and gamma-ray. To extract important parameters associated with the optical TES, complex impedances at high frequencies (> 1 MHz) need to be measured, where the parasitic impedance in the circuit and reflections of electrical signals due to discontinuities in the characteristic impedance of the readout circuits become significant. This prevents the measurements of the current sensitivity β , which can be extracted from the complex impedance. In usual setups, it is hard to build a circuit model taking into account the parasitic impedances and reflections. In this study, we present an alternative method to estimate a transfer function without investigating the details of the entire circuit. Based on this method, the complex impedance up to 30 MHz was measured. The parameters were extracted from the impedance and were compared with other measurements. Using these parameters, we calculated the theoretical limit on an energy resolution and compared it with the measured energy resolution. In this paper, the reasons for the deviation of the measured value from theoretically predicted values will be discussed.

Low Frequency (11 mHz) Oscillations in H1743-322: A New Class of Black Hole QPOs?

Science.gov (United States)

Altamirano, D.; Strohmayer, T.

2012-01-01

We report the discovery of quasi-periodic oscillations (QPO) at approx 11 mHz in two RXTE observations and one Chandra observation of the black hole candidate HI743-322. The QPO is observed only at the beginning of the 2010 and 2011 outbursts at similar hard color and intensity, suggestive of an accretion state dependence for the QPO. Although its frequency appears to be correlated with Xray intensity on timescales of a day, in successive outbursts eight months apart we measure a QPO frequency that differs by less than approximately equals 0.0015 Hz while the intensity had changed significantly. We show that this 11 mHz QPO is different from the so-called Type-C QPOs seen in black holes and that the mechanisms that produce the two flavors of variability are most probably independent. We compare the 11 mHz QPO with other variability phenomena seen in accreting black holes and neutron stars and conclude that although at 1-2 orders of magnitude lower in frequency, they best resemble the so-called "1 Hz" QPOs seen in dipping neutron star systems. If confirmed, H1743-322 is the first black hole showing this type of variability. Given the unusual characteristics and the hard-state dependence of the 11 mHz QPO, we speculate that these oscillations might instead be related to the radio jets observed in HI743-322. It remains unexplained, however, why similar QPOs have not yet been identified in other black holes and why they have only been seen in the last two outbursts of HI743-322.

Physics design of a 10 MeV, 6 kW travelling wave electron linac for ...

Indian Academy of Sciences (India)

2016-10-11

Oct 11, 2016 ... We present the physics design of a 10 MeV, 6 kW S-band (2856 MHz) electron linear ... linac (in contrast with standing wave linac) is that it accepts the RF power over a band of frequencies. Three- ... structures are preferred for relatively higher energy ... klystron in a TW linac, which results in cost reduction.

Effects of 415 MHz frequency on human lymphocyte genome

International Nuclear Information System (INIS)

Garaj-Vrhovac, V.; Fucic, A.; Kubelka, D.; Vojvodic, S.

1996-01-01

The continuously increasing use of artificial sources of electromagnetic radiation in industry and medicine has been accompanied in everyday life with telecommunication systems which is followed with great interest in possible hazardous effects of this type of radiation. The interesting applications of mobile telecommunications and the use of cellular phones are of topic interest. Numerous cytogenetic investigations are focused on the effects of microwave radiation from mobile communications frequency of 450 and 950 MHz on isolated cells in vitro. The aim of this work was to investigate the effects of microwaves from mobile telephone frequencies on human peripheral blood lymphocytes cultured in vitro. (author)

Simulation and fabrication of 0-3 composite PZT films for ultrahigh frequency (100-300 MHz) ultrasonic transducers

Science.gov (United States)

Chen, Xiaoyang; Fei, Chunlong; Chen, Zeyu; Chen, Ruimin; Yu, Ping; Chen, Zhongping; Shung, K. Kirk; Zhou, Qifa

2016-03-01

This paper presents simulation, fabrication, and characterization of single-element ultrahigh frequency (100-300-MHz) needle ultrasonic transducers based on 0-3 composite Pb(Zr0.52Ti0.48)O3 (PZT) films prepared by using composite ceramic sol-gel film and sol-infiltration technique. The center frequency of the developed transducer at 300-MHz was the highest frequency of PbTiO3 ceramic-based ultrasonic transducers ever reported. Furthermore, a brief description of the composite model was followed by the development of a new expression for predicting the longitudinal velocity, the clamped dielectric constant, and the complex electromechanical coupling coefficient kt of these films, which is very important in ultrasonic transducer design. Moreover, these parameters are difficult to obtain by measuring the frequency dependence of impedance and phase angle because of the weak signal of the previous 0-3 composite films transducer (>100 MHz). The modeling results show that the Cubes model with a geometric factor n = 0.05 fits well with the measured data. This model will be helpful for developing the 0-3 composite systems for ultrahigh frequency ultrasonic transducer design.

A compact 10 kW, 476 MHz solid state radio frequency amplifier for pre-buncher cavity of free electron laser injector linear accelerator

Energy Technology Data Exchange (ETDEWEB)

Mohania, Praveen; Mahawar, Ashish; Shrivastava, Purushottam; Gupta, P. D. [Raja Rammana Centre for Advanced Technology (RRCAT), Indore 452013 (India)

2013-09-15

A 10 kW, 476 MHz, 0.1% duty cycle solid state RF amplifier system for driving sub-harmonic, pre-buncher cavity of IR-FEL injector LINAC, has been developed at RRCAT. The 10 kW power is achieved by combining output of eight 1400 W amplifier modules using 8-way planar corporate combiner. The solid state amplifier modules have been developed using 50 V RF LDMOS transistors which although meant for push-pull operation are being used in single ended configuration with matching circuit developed on a thin (25 mils), high dielectric constant (9.7), low loss microwave laminate with an aim to have a compact structure. Ease of fabrication, modularity, small size, and low cost are the important features of this design which could be used as a template for low duty cycle medium to high pulsed power UHF amplifier system.

Three-dimensional simulation studies of 10 MeV, 352.2 MHz drift ...

Indian Academy of Sciences (India)

It is proposed to build a drift tube Linac (DTL) at Raja Ramanna Centre for Advanced Technology, Indore, India, that will form a part of the future Spallation Neutron Source. This DTL will accelerate 30 mA H-ion beam from 3 MeV to 10 MeV. The DTL is designed to operate at 352.2 MHz with a maximum duty cycle of 3%.

Femtosecond Ti:sapphire cryogenic amplifier with high gain and MHz repetition rate

DEFF Research Database (Denmark)

Dantan, Aurelien Romain; Laurat, Julien; Ourjoumtsev, Alexei

2007-01-01

We demonstrate high gain amplification of 160-femtosecond pulses in a compact double-pass cryogenic Ti:sapphire amplifier. The setup involves a negative GVD mirrors recompression stage, and operates with a repetition rate between 0.2 and 4 MHz with a continuous pump laser. Amplification factors a...... as high as 17 and 320 nJ Fourier-limited pulses are obtained at a 800 kHz repetition rate....

Measurement of spatial and temporal evolution of electromagnetic fields in a 100 MHz plasma source using B dot and double dipole probes

Energy Technology Data Exchange (ETDEWEB)

Lane, Barton, E-mail: barton.lane@tel.com; Campbell, Colin; Sawada, Ikuo; Ventzek, Peter L. G., E-mail: peter.ventzek@tel.com [Tokyo Electron America, Inc., 2400 Grove Blvd., Austin, Texas 78741 (United States)

2016-05-15

Very high frequency plasma sources are often accompanied by plasma density nonuniformities associated with a standing-wave effect. Electron density measurements using a plasma absorption probe show density nonuniformities that can be larger than predicted by a standing wave model. These structures have been associated with harmonics of the electric fields in the plasma. The authors present the first time and phase-resolved measurements of the spatial structure of the electromagnetic waves in a 100 MHz plasma source using argon at 40 mTorr employing a B dot probe. The authors show that the harmonic structure is related to a current reversal and subsequent circulation that appears when the sheath collapses during the radio frequency cycle. The circulation is driven by inward traveling waves that are electromagnetic in nature, not plasma waves traveling at the electron thermal velocity. Double dipole probe measurements were used to validate the B dot probe electric field measurements derived from the time derivative of Β{sub θ} which is derived from the B dot probe signal.

A novel method for determining calibration and behavior of PVDF ultrasonic hydrophone probes in the frequency range up to 100 MHz.

Science.gov (United States)

Bleeker, H J; Lewin, P A

2000-01-01

A new calibration technique for PVDF ultrasonic hydrophone probes is described. Current implementation of the technique allows determination of hydrophone frequency response between 2 and 100 MHz and is based on the comparison of theoretically predicted and experimentally determined pressure-time waveforms produced by a focused, circular source. The simulation model was derived from the time domain algorithm that solves the non linear KZK (Khokhlov-Zabolotskaya-Kuznetsov) equation describing acoustic wave propagation. The calibration technique data were experimentally verified using independent calibration procedures in the frequency range from 2 to 40 MHz using a combined time delay spectrometry and reciprocity approach or calibration data provided by the National Physical Laboratory (NPL), UK. The results of verification indicated good agreement between the results obtained using KZK and the above-mentioned independent calibration techniques from 2 to 40 MHz, with the maximum discrepancy of 18% at 30 MHz. The frequency responses obtained using different hydrophone designs, including several membrane and needle probes, are presented, and it is shown that the technique developed provides a desirable tool for independent verification of primary calibration techniques such as those based on optical interferometry. Fundamental limitations of the presented calibration method are also examined.

Computer-aided studies of the ALS 500 MHz storage ring cavity

International Nuclear Information System (INIS)

Lo, C.C.; Taylor, B.

1989-03-01

The design of the ALS storage ring 500 MHz cavity has been modeled with Mafia and Urmel codes. The effects of the holes cut for the drive port, the higher order mode damping port, the probe port and tuner plunger were modeled with the Mafia codes. The frequency dependence on the shape and spacing of the nose cones and the general shape of the cavity were modeled with Urmel codes. 9 refs., 7 figs., 1 tab

Library usage patterns in the electronic information environment. Electronic journals, Use studies, Libraries, Medical libraries

Directory of Open Access Journals (Sweden)

B. Franklin

2004-01-01

Full Text Available This paper examines the methodology and results from Web-based surveys of more than 15,000 networked electronic services users in the United States between July 1998 and June 2003 at four academic health sciences libraries and two large main campus libraries serving a variety of disciplines. A statistically valid methodology for administering simultaneous Web-based and print-based surveys using the random moments sampling technique is discussed and implemented. Results from the Web-based surveys showed that at the four academic health sciences libraries, there were approximately four remote networked electronic services users for each in-house user. This ratio was even higher for faculty, staff, and research fellows at the academic health sciences libraries, where more than five remote users for each in-house user were recorded. At the two main libraries, there were approximately 1.3 remote users for each in-house user of electronic information. Sponsored research (grant funded research accounted for approximately 32% of the networked electronic services activity at the health sciences libraries and 16% at the main campus libraries. Sponsored researchers at the health sciences libraries appeared to use networked electronic services most intensively from on-campus, but not from in the library. The purpose of use for networked electronic resources by patrons within the library is different from the purpose of use of those resources by patrons using the resources remotely. The implications of these results on how librarians reach decisions about networked electronic resources and services are discussed.

Time-lens based synchronizer and retimer for 10 Gb/s Ethernet packets with up to ±1MHz frequency offset

DEFF Research Database (Denmark)

Laguardia Areal, Janaina; Hu, Hao; Palushani, Evarist

2010-01-01

We present a time-lens based all-optical 10 Gb/s frame synchronizer and retimer. Our scheme can work with a 4096-bit frame, with frequency offset up to 1MHz, which is demonstrated by experimental results.......We present a time-lens based all-optical 10 Gb/s frame synchronizer and retimer. Our scheme can work with a 4096-bit frame, with frequency offset up to 1MHz, which is demonstrated by experimental results....

Meandered Monopoles for 700 MHz LTE Handsets and Improved MIMO Channel Capacity Performance

Directory of Open Access Journals (Sweden)

I. Dioum

2011-12-01

Full Text Available In this paper, we present the design and the measurement of MIMO meandered monopole antennas and the computation of their channel capacity performance. The initial proposed handset-system is composed of a meandered monopole operating in the LTE 700 MHz band, connected to a parasitic radiating element for the upper 2.5 GHz LTE band. Two antennas of the same kind are then closely positioned on the same 120x50 mm2 Printed Circuit Board (PCB. A neutralization line connects the two antennas to enhance their port-to-port isolation in the 700 MHz band. The computation of the channel capacity performance in this band is based on propagation simulations performed with the GRIMM model from the CREMANT. Two system-prototypes are evaluated: one with the neutralization line for enhanced port-to-port isolation and a second without the neutralization exhibiting poor antenna-to-antenna isolation. It is demonstrated that the neutralization technique helps in giving a minimum improvement of 12% of the capacity performance of the handset-system, and a maximum improvement 46%, in the chosen environment.

Authentication of beef versus horse meat using 60 MHz 1H NMR spectroscopy.

Science.gov (United States)

Jakes, W; Gerdova, A; Defernez, M; Watson, A D; McCallum, C; Limer, E; Colquhoun, I J; Williamson, D C; Kemsley, E K

2015-05-15

This work reports a candidate screening protocol to distinguish beef from horse meat based upon comparison of triglyceride signatures obtained by 60 MHz (1)H NMR spectroscopy. Using a simple chloroform-based extraction, we obtained classic low-field triglyceride spectra from typically a 10 min acquisition time. Peak integration was sufficient to differentiate samples of fresh beef (76 extractions) and horse (62 extractions) using Naïve Bayes classification. Principal component analysis gave a two-dimensional "authentic" beef region (p=0.001) against which further spectra could be compared. This model was challenged using a subset of 23 freeze-thawed training samples. The outcomes indicated that storing samples by freezing does not adversely affect the analysis. Of a further collection of extractions from previously unseen samples, 90/91 beef spectra were classified as authentic, and 16/16 horse spectra as non-authentic. We conclude that 60 MHz (1)H NMR represents a feasible high-throughput approach for screening raw meat. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Central FPGA-based Destination and Load Control in the LHCb MHz Event Readout

CERN Document Server

Jacobsson, Richard

2012-01-01

The readout strategy of the LHCb experiment [1] is based on complete event readout at 1 MHz [2]. Over 300 sub-detector readout boards transmit event fragments at 1 MHz over a commercial 70 Gigabyte/s switching network to a distributed event building and trigger processing farm with 1470 individual multi-core computer nodes [3]. In the original specifications, the readout was based on a pure push protocol. This paper describes the proposal, implementation, and experience of a powerful non-conventional mixture of a push and a pull protocol, akin to credit-based flow control. A high-speed FPGA-based central master module controls the event fragment packing in the readout boards, the assignment of the farm node destination for each event, and controls the farm load based on an asynchronous pull mechanism from each farm node. This dynamic readout scheme relies on generic event requests and the concept of node credit allowing load balancing and trigger rate regulation as a function of the global farm load. It also ...

The Continuous Electron Beam Accelerator Facility

International Nuclear Information System (INIS)

Grunder, H.A.; Bisognano, J.J.; Diamond, W.I.; Hartline, B.K.; Leemann, C.W.; Mougey, J.; Sundelin, R.M.; York, R.C.

1987-01-01

On February 13, 1987, construction started on the Continuous Electron Beam Accelerator Facility - a 4-GeV, 200-μA, continuous beam, electron accelerator facility designed for nuclear physics research. The machine has a racetrack configuration with two antiparallel, 500-MeV, superconducting linac segments connected by beam lines to allow four passes of recirculation. The accelerating structure consists of 1500-MHz, five-cell niobium cavities developed at Cornell University. A liquid helium cryogenic system cools the cavities to an operating temperature of 2 K. Beam extraction after any three of the four passes allows simultaneous delivery of up to three beams of independently variable currents and different, but correlated, energies to the three experimental areas. Beam breakup thresholds exceed the design current by nearly two orders of magnitude. Project completion and the start of physics operations are scheduled for 1993. The total estimated cost is $255 million

Electronic resources of the rare books and valuable editions department of the Central Scientific Library of the V.N. Karazin Kharkiv National University: open access for research

Directory of Open Access Journals (Sweden)

І. К. Журавльова

2014-12-01

Full Text Available The article describes tasks that electronic collections of rare books fulfill: broad access for readers to rare and valuable editions providing, preservation of ensuring of the original. On the example of the electronic collection of the Central Scientific Library of the V.N. Karazin Kharkiv National University – «eScriptorium: electronic archive of rare books and manuscripts for research and education» the possibility of the full-text resources of the valuable editions using is shown. The principles of creation, structure, chronological frameworks, directions of adding the documents to the archive are represented. The perspectives of the project development are outlined as well as examples of the digital libraries of the European countries and Ukraine are provided, the actual task of preserving the originals of the rare books of the country is raised, the innovative approaches to serving users with electronic resources are considered. The evidences of cooperation of the Central Scientific Library of the V.N. Karazin Kharkiv National University with the largest world digital libraries: World Digital Library and Europeana are provided.

Polarized Electron Beams for Nuclear Physics at the MIT Bates Accelerator Center

CERN Document Server

Farkhondeh, Manouchehr; Franklin, Wilbur; Ihloff, Ernie; McAllister, Brian; Milner, Richard; North, William; Tschalär, C; Tsentalovich, Evgeni; Wang, Defa; Wang, Dong; Wang, Fuhua; Zolfaghari, Abbasali; Zwart, Townsend; van der Laan, Jan

2005-01-01

The MIT Bates Accelerator Center is delivering highly polarized electron beams to its South Hall Ring for use in Nuclear Physics Experiments. Circulating electron currents in excess of 200 mA with polarization of 70% are scattered from a highly polarized, but very thin atomic beam source deuterium target. At the electron source a compact diode laser creates photoemission of quasi-CW mA pulses of polarized electrons at low duty factors from a strained GaAs photocathode. Refurbished RF transmitters provide power to the 2856 MHz linac, accelerating the beam to 850 MeV in two passes before injection into the South Hall Ring. In the ring a Siberian snake serves to maintain a high degree of longitudinal polarization at the BLAST scattering target. A Compton laser back-scattering polarimeter measures the electron beam polarization with a statistical acuracy of 6% every 15 minutes.

Characterization of Definity™ Ultrasound Contrast Agent at Frequency Range of 5–15 MHz

NARCIS (Netherlands)

Faez, Telli; Goertz, David; de Jong, N.

2011-01-01

The status of vasa vasorum, which can be imaged using ultrasound contrast agents, is an indication for the progression of atherosclerosis. The preferred ultrasound frequency for this purpose is between 5 and 15 MHz. Therefore, it is essential to have knowledge about the acoustic properties of

Electronics development for the ATLAS liquid argon calorimeter trigger and readout for future LHC running

Energy Technology Data Exchange (ETDEWEB)

Hopkins, Walter

2017-02-11

The upgrade of the LHC will provide 7 times greater instantaneous and 10 times greater total luminosities than assumed in the original design of the ATLAS Liquid Argon (LAr) Calorimeters. Radiation tolerance criteria and an improved trigger system with higher acceptance rate and longer latency require an upgrade of the LAr readout electronics. In the first upgrade phase in 2019–2020, a trigger readout with up to 10 times higher granularity will be implemented. This allows an improved reconstruction of electromagnetic and hadronic showers and will reduce the background for electron, photon and energy-flow signals at the first trigger level. The analog and digital signal processing components are currently in their final design stages and a fully functional demonstrator system is operated and tested on the LAr Calorimeters. In a second upgrade stage in 2024–2026, the readout of all 183,000 LAr Calorimeter cells will be performed without trigger selection at 40 MHz sampling rate and 16 bit dynamic range. Calibrated energies of all cells will be available at the second trigger level operating at 1 MHz, in order to allow further mitigation of pile-up effects in energy reconstruction. Radiation tolerant, low-power front-end electronics optimized for high pile-up conditions are currently being developed, including pre-amplifier, ADC and serializer components in 65–180 nm technology. This contribution will give an overview of the future LAr readout electronics and present research results from the two upgrade programs.

Development of 350 MHz/1000 Watt intermediate power amplifier for 400 keV RFQ accelerator

International Nuclear Information System (INIS)

Pande, M.M.; Patel, N.R.; Shinde, K.R.; Rao, M.K.V.; Handu, V.K.

2005-01-01

Two numbers of high power RF systems, each delivering around 35 to 40 kW of power at 350 MHz are being developed in BARC. These High Power Amplifiers (HPA) cater to the total need of 70 kW of RF power required by the 400 keV (Deuterium) RFQ accelerator. This RFQ will replace the existing 400 keV DC accelerator of 14 MeV Neutron Generator. The RFQ will accelerate a deuterium beam from 50 keV to 400 keV to impinge upon a tritium target inside a sub critical assembly. Each of these 35 / 40 KW HPA requires a drive power of around 1000 / 1500 Watt respectively. Hence a intermediate power amplifier (IPA) bas been designed to deliver the power of 1000 Watt at the rate of 350 MHz. The paper describes the development of this amplifier

Strongly driven electron spins using a Ku band stripline electron paramagnetic resonance resonator

Science.gov (United States)

Yap, Yung Szen; Yamamoto, Hiroshi; Tabuchi, Yutaka; Negoro, Makoto; Kagawa, Akinori; Kitagawa, Masahiro

2013-07-01

This article details our work to obtain strong excitation for electron paramagnetic resonance (EPR) experiments by improving the resonator's efficiency. The advantages and application of strong excitation are discussed. Two 17 GHz transmission-type, stripline resonators were designed, simulated and fabricated. Scattering parameter measurements were carried out and quality factor were measured to be around 160 and 85. Simulation results of the microwave's magnetic field distribution are also presented. To determine the excitation field at the sample, nutation experiments were carried out and power dependence were measured using two organic samples at room temperature. The highest recorded Rabi frequency was rated at 210 MHz with an input power of about 1 W, which corresponds to a π/2 pulse of about 1.2 ns.

Electron Source based on Superconducting RF

Science.gov (United States)

Xin, Tianmu

High-bunch-charge photoemission electron-sources operating in a Continuous Wave (CW) mode can provide high peak current as well as the high average current which are required for many advanced applications of accelerators facilities, for example, electron coolers for hadron beams, electron-ion colliders, and Free-Electron Lasers (FELs). Superconducting Radio Frequency (SRF) has many advantages over other electron-injector technologies, especially when it is working in CW mode as it offers higher repetition rate. An 112 MHz SRF electron photo-injector (gun) was developed at Brookhaven National Laboratory (BNL) to produce high-brightness and high-bunch-charge bunches for electron cooling experiments. The gun utilizes a Quarter-Wave Resonator (QWR) geometry for a compact structure and improved electron beam dynamics. The detailed RF design of the cavity, fundamental coupler and cathode stalk are presented in this work. A GPU accelerated code was written to improve the speed of simulation of multipacting, an important hurdle the SRF structure has to overcome in various locations. The injector utilizes high Quantum Efficiency (QE) multi-alkali photocathodes (K2CsSb) for generating electrons. The cathode fabrication system and procedure are also included in the thesis. Beam dynamic simulation of the injector was done with the code ASTRA. To find the optimized parameters of the cavities and beam optics, the author wrote a genetic algorithm Python script to search for the best solution in this high-dimensional parameter space. The gun was successfully commissioned and produced world record bunch charge and average current in an SRF photo-injector.

Detection of ordering of electrons on liquid helium

International Nuclear Information System (INIS)

Deville, G.; Gallet, F.; Marty, D.; Poitrenaud, J.; Valdes, A.; Williams, F.I.B.

1980-05-01

The ordering is observed for surface densities 1.5 10 8 8 cm -2 at temperatures 0.3 < T < 0.8 K by monitoring the response to a 25 MHz in plane electric field polarized parallel to its wave vector. Ordering influences this susceptibility by the shift in frequency of the plasmon modes as the electrons correlate and so self-trap into the surface deformation they impose on the helium. This experiment is sensitive to the optical mode of the coupled systems (electron and surface deformation move in antiphase), whereas the first observation of ordering by Grimes and Adams was based on the appearance of the acoustical modes (electron + deformation move in phase). Our results for the ordering temperatures can be expressed by n(c) approximately T(c)sup(1.8+-0.2), or, if one fits the results GAMMA(c)=118+-10. It seems that the optical modes establish themselves before the acoustic modes

Performance of the advanced photon source (APS) linac beam position monitors (BPMs) with logarithmic amplifier electronics

International Nuclear Information System (INIS)

Fuja, R.E.; White, M.

1995-01-01

This paper discusses the performance of the logarithmic amplifier electronics system used with stripline BPMs to measure electron and positron beam positions at the APS linac. The 2856-MHz, S-band linac accelerates 30-nsec pulses of 1.7 A of electrons to 200 MeV, and focuses them onto a positron conversion target. The resulting 8 mA of positrons are further accelerated to 450 MeV by the positron linac. Beam position resolutions of 50 μm are easily obtainable in both the electron and positron linacs. The resolution of the 12-bit A/D converters limits the ultimate beam positron resolution to between 20 and 30 μm at this time

Electronic tracking of human resource skills and knowledge, just in time training, manageable due diligence

Energy Technology Data Exchange (ETDEWEB)

Kolodziej, M.A. [Quick Test International Inc., (Canada). Canadian Technology Human Resource Board; Baker, O. [KeySpan Energy Canada, Calgary, AB (Canada)

2001-06-01

KeySpan Energy Canada is in the process of obtaining recognition of various occupational profiles including pipeline operators, inspectors, and field and plant operators from various certifying organizations. The process of allowing individuals to obtain certification is recognized by Canadian Technology Human Resources Board as a step towards national standards for technologists and technicians. Proven competency is a must for workers in todays oil industry in response to increasingly stringent government safety regulations, environmental concerns and high public scrutiny. Quick Test international Inc. has developed a management tool in collaboration with end users at KeySpan Energy Canada. It is an electronic, Internet based competency tool for tracking personal competencies and maintaining continued competency. Response to the tool has been favourable. 2 refs., 4 figs.

LINAC DESIGN FOR AN ARRAY OF SOFT X-RAY FREE ELECTRON LASERS

International Nuclear Information System (INIS)

Zholents, Alexander A.; Kur, E.; Penn, G.; Qiang, Ji; Venturini, M.; Wells, R. P.

2008-01-01

The design of the linac delivering electron bunches into ten independent soft x-ray free electron lasers (FELs) producing light at 1 nm and longer wavelengths is presented. The bunch repetition rate in the linac is 1 MHz and 100 kHz in each of ten FEL beam lines. Various issues regarding machine layout and lattice, bunch compression, collimation, and the beam switch yard are discussed. Particular attention is given to collective effects. A demanding goal is to preserve both a low beam slice emittance and low slice energy spread during acceleration, bunch compression and distribution of the electron bunches into the array of FEL beamlines. Detailed studies of the effect of the electron beam microbunching caused by longitudinal space-charge forces and coherent synchrotron radiation (CSR) have been carried out and their results are presented

Acceleration tests of the INS 25.5-MHz split coaxial RFQ

International Nuclear Information System (INIS)

Arai, S.; Imanishi, A.; Morimoto, T.; Tojyo, E.; Tokuda, N.; Shibuya, S.

1991-05-01

The INS 25.5-MHz split coaxial RFQ, a linac that accelerates ions with a charge-to-mass ratio greater than 1/30 from 1 to 45.4 keV/u, is now undergoing acceleration tests with a beam of molecular nitrogen (N 2 + ) ions. Results so far obtained show that the RFQ operates in accordance with the design. Presented are preliminary results on the beam performance: emittances of the in- and output beams, output energy and its spread, and beam transmission. (author)

MHz-level self-sustained pulsation in polymer microspheres on a chip

Directory of Open Access Journals (Sweden)

Zhou-Chen Luo

2014-12-01

Full Text Available We observe MHz-level periodic self-sustained pulsation (SSP in the transmission spectrum of a polydimethylsiloxane (PDMS spherical microcavity on a silicon chip, under a fixed-frequency continuous laser excitation. The SSP results from the strong competition between the thermo-optic and thermal expansion effects of PDMS within the cavity mode volume. The experimental results show good agreement with the theoretical prediction by considering the modification of the thermal expansion coefficient and the temperature distribution within the mode volume.

Data acquisition electronics for NESTOR experiment: project and tests

International Nuclear Information System (INIS)

Ameli, Fabrizio; Bonori, Maurizio; Bottai, Sergio; Capone, Antonio; Curti, Franco; Desiati, Paolo; De Marchis, Giancarlo; Massa, Fabrizio; Masullo, Rocco; Piccari, Luigi; Vannucci, Italo

1999-01-01

The NESTOR detector, at present under construction, is a telescope for high-energy neutrino astronomy. The apparatus, based on Cherenkov light detection, will be deployed in deep sea (about 4000 m) near the S.W. Greek coast. We briefly describe the NESTOR detector, then we describe with more details the electronics for NESTOR data acquisition and transmission. The detector signals are sampled at 200 MHz and all the resulting information are transmitted to the laboratory on 30 km long electro-optical cable. The estimated Mean Time Between Failure of the full electronics system is greater than 20 years. Tests performed on the first prototypes confirm the main characteristics of these electronics: the dynamic range allowed for the signals is bigger than 1000, the pulse shape is reconstructed with an 8 bit ADC accuracy and the resolution in the measurement of the signal 'threshold crossing time' is better than 200 ps