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Sample records for water resistor divider

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

    Science.gov (United States)

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

    2010-03-01

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

  2. Resistor holder

    International Nuclear Information System (INIS)

    This patent describes a resistor device for use with an electrostatic particle accelerator having apertured axially spaced apart electrode plates and annular insulators, each insulator being positioned between a pair of electrode plates. It comprises an elongate tubular housing formed of electrically conductive material, fixed end cap formed of conductive material and being connected to one end of the tubular housing, movable end cap formed of conductive material spaced radially inwardly and projecting interiorly of the tubular housing at the other end of the latter, and elongate cylindrical resistor element, means engaging the resistor element and positioning the latter in inwardly spaced concentric relation within the tubular housing, resilient means in the tubular housing engaging the fixed end cap and the resistor element for permitting yieldable axial movement of the latter relative to the housing, an annular conducting element electrically connected to the other end of the tubular housing and being spaced radially outwardly of the movable cap and defining an annular spark gap with the latter, and means electrically connecting the ends of the resistor element with the movable fixed end caps

  3. The Vivitron resistors

    International Nuclear Information System (INIS)

    The results of the tests performed on the 600 M? Metallux resistors are discussed. The aim of the investigation was to study the influence of the pressure and voltage on the resistivity. 24 resistors were examined. The constant voltage experimental device is described. The tests were performed at different SF6 pressures. The resistor's mean value is 595.5 24 M? for any pressure and voltage

  4. Babylonian resistor networks

    International Nuclear Information System (INIS)

    The ancient Babylonians had an iterative technique for numerically approximating the values of square roots. Their method can be physically implemented using series and parallel resistor networks. A recursive formula for the equivalent resistance Req is developed and converted into a nonrecursive solution for circuits using geometrically increasing numbers of identical resistors. As an example, 24 resistors R are assembled into a second-order network and Req/R is measured to equal √2 to better than 0.2%, as could be done in an introductory physics laboratory. (paper)

  5. Application to printed resistors

    International Nuclear Information System (INIS)

    Most of printed circuit boards are made at present by etching copper foils which are laminated on insulating composite boards of paper/phenol resin or glass nonwoven fabric/epoxy rein. This is called subtractive process, and since this is a wet process, the problem of coping with the pollution due to etching solution, plating solution and others is involved. As the method of solving this problem, attention has been paid to the dry process which forms conductor patterns by screen printing using electro-conductive paste. For such resin substrates, generally polymer thick films (PTF) using thermosetting resin as the binder are used. Also the research on the formation of resistors, condensers and other parts by printing using the technology of cermet thick films (CTF) and PTF is active, and it is partially put in practical use. The problems are the deformation and deterioration of substrates, therefore, as the countermeasures, electron beam hardening type PTF has been studied, and various pastes have been developed. In this paper, electron beam hardening type printed resistors are reported. The features, resistance paste, and a number of the experiments on printed resistors are described. (K.I.)

  6. Decision-centric adaptation appraisal for water management across Colorado’s Continental Divide

    OpenAIRE

    David N. Yates; Kathleen A. Miller; Robert L Wilby; Laurna Kaatz

    2015-01-01

    A multi-step decision support process was developed and applied to the physically and legally complex case of water diversions from the Upper Colorado River across the Continental Divide to serve cities and farms along Colorado’s Front Range. We illustrate our approach by simulating the performance of an existing drought-response measure, the Shoshone Call Relaxation Agreement (SCRA) [the adaptation measure], using the Water Evaluation and Planning (WEAP) tool [the hydrologic cycle and water ...

  7. Boron-implanted silicon resistors

    International Nuclear Information System (INIS)

    The sheet resistance of silicon resistors implanted with boron at room temperature has been experimentally determined for doses from 5 x 1012 to 2 x 1016 cm-2. The results have been compared with the calculated values. Two methods for minimizing the temperature coefficients, TCR, are described, and their merits and disadvantages are discussed. For a 1 kΩ resistor, TCR can be reduced to 1000 ppm/0C by implanting 11B+ at low energy, 5 to 10 keV, and to less than 100 ppm/0C by implanting a suitable dose of Ar+ damage. In a two-terminal resistor the end effect of the total sheet resistance on TCR and on voltage coefficient VCR was also investigated. (author)

  8. Decision-centric adaptation appraisal for water management across Colorado’s Continental Divide

    Directory of Open Access Journals (Sweden)

    David N. Yates

    2015-01-01

    Full Text Available A multi-step decision support process was developed and applied to the physically and legally complex case of water diversions from the Upper Colorado River across the Continental Divide to serve cities and farms along Colorado’s Front Range. We illustrate our approach by simulating the performance of an existing drought-response measure, the Shoshone Call Relaxation Agreement (SCRA [the adaptation measure], using the Water Evaluation and Planning (WEAP tool [the hydrologic cycle and water systems model]; and the Statistical DownScaling Model (SDSM-DC [the stochastic climate scenario generator]. Scenarios relevant to the decision community were analyzed and results indicate that this drought management measure would provide only a small storage benefit in offsetting the impacts of a shift to a warmer and drier future climate coupled with related environmental changes. The analysis demonstrates the importance of engaging water managers in the development of credible and computationally efficient decision support tools that accurately capture the physical, legal and contractual dimensions of their climate risk management problems.

  9. Farey Sequences and Resistor Networks

    Indian Academy of Sciences (India)

    Sameen Ahmed Khan

    2012-05-01

    In this article, we employ the Farey sequence and Fibonacci numbers to establish strict upper and lower bounds for the order of the set of equivalent resistances for a circuit constructed from equal resistors combined in series and in parallel. The method is applicable for networks involving bridge and non-planar circuits.

  10. Impedance of Finite Length Resistor

    CERN Document Server

    Krinsky, Samuel; Podobedov, Boris

    2005-01-01

    We determine the impedance of a cylindrical metal tube (resistor) of radius a and length g, attached at each end to perfect conductors of semi-infinite length. Our main interest is in the behavior of the impedance at high frequency (k>>1/a). In the equilibrium regime, ka2

  11. Remote Experiments in Resistor Measurement

    Directory of Open Access Journals (Sweden)

    Popescu Viorel

    2009-10-01

    Full Text Available The paper describes blended learningapproach to teaching resistor measurement. It is basedon “Learning by Doing” paradigm: interacticesimulation, laboratory plants, real experimentsaccessed by Web Publishing Tools under LabVIEW.Studying and experimenting access is opened for 24hours a day, 7 days a week under Moodle bookingsystem.

  12. Discrete/PWM Ballast-Resistor Controller

    Science.gov (United States)

    King, Roger J.

    1994-01-01

    Circuit offers low switching loss and automatic compensation for failure of ballast resistor. Discrete/PWM ballast-resistor controller improved shunt voltage-regulator circuit designed to supply power from high-resistance source to low-impedance bus. Provides both coarse discrete voltage levels (by switching of ballast resistors) and continuous fine control of voltage via pulse-width modulation.

  13. Thick Film Fail-Safe Resistors

    OpenAIRE

    Wojcicka, D. L.; St. Nowak

    1983-01-01

    The investigations of low resistance thick film fail-safe resistors are presented. Particularly the shape of a resistive path; the temperature of the central part of the resistor while increasing the power up to 4 Watts; the kind of composition material for the resistive path vs. extensometer effect, and the stability of the resistor are discussed.

  14. Preparation and Properties of Thick Film Resistors Containing Cadmium Glasses and Cadmium Oxide

    OpenAIRE

    Broukal, J.; R. Kuel

    1980-01-01

    The electrical properties of resistors comprising finely divided CdO and cadmium glass, were investigated. The change in a temperature coefficient of resistance from about ?500 ppm/? to +70 ppm/? was realized by addition of a further component to the resistor paste. Differential thermal analysis, X-ray diffraction analysis and scanning electron microscopy were used for studying crystalline phases in glass containing CdO.

  15. Direct High-Precision Measurements of the (87)Sr/(86)Sr Isotope Ratio in Natural Water without Chemical Separation Using Thermal Ionization Mass Spectrometry Equipped with 10(12) Ω Resistors.

    Science.gov (United States)

    Li, Chao-Feng; Guo, Jing-Hui; Chu, Zhu-Yin; Feng, Lian-Jun; Wang, Xuan-Ce

    2015-07-21

    Thermal ionization mass spectrometry (TIMS) allows excellent precision for determining Sr isotope ratios in natural water samples. Traditionally, a chemical separation procedure using cation exchange resin has been employed to obtain a high purity Sr fraction from natural water, which makes sample preparation time-consuming. In this study, we present a rapid and precise method for the direct determination of the Sr isotope ratio of natural water using TIMS equipped with amplifiers with two 10(12) Ω resistors. To eliminate the (87)Rb isobaric interference, Re ribbons are used as filaments, providing a significant advantage over W ribbons in the inhibition of Rb(+) emission, based on systematically examining a series of NIST SRM987 standard doping with various amounts of Rb using Re and W ribbons. To validate the applicability of our method, twenty-two natural water samples, including different water types (rain, snow, river, lake and drinking water), that show a large range in Sr content variations (2.54-922.8 ppb), were collected and analyzed from North and South China. Analytical results show good precision (0.003-0.005%, 2 RSE) and the method was further validated by comparative analysis of the same water with and without chemical separation. The method is simple and rapid, eliminates sample preparation time, and prevents potential contamination during complicated sample-preparation procedures. Therefore, a high sample throughput inherent to the TIMS can be fully utilized. PMID:26105121

  16. DIGITAL DIVIDE

    Directory of Open Access Journals (Sweden)

    SANTOSH GOBRU JADHAO

    2013-02-01

    Full Text Available The digital divide refers to the gap between people with effective access todigital and information technology and those with very limited or no access at all. Itincludes the imbalance both in physical access to technology and the resources and skillsneeded to effectively participate as a digital citizen. Knowledge divide reflects the accessof various social groupings to information and knowledge, typically gender, income,race, and by location. The term global digital divide refers to differences in accessbetween countries.

  17. Reliability growth of thin film resistors contact

    Directory of Open Access Journals (Sweden)

    Lugin A. N.

    2010-10-01

    Full Text Available Necessity of resistive layer growth under the contact and in the contact zone of resistive element is shown in order to reduce peak values of current flow and power dissipation in the contact of thin film resistor, thereby to increase the resistor stability to parametric and catastrophic failures.

  18. Infant breathing rate counter based on variable resistor for pneumonia

    Science.gov (United States)

    Sakti, Novi Angga; Hardiyanto, Ardy Dwi; La Febry Andira R., C.; Camelya, Kesa; Widiyanti, Prihartini

    2016-03-01

    Pneumonia is one of the leading causes of death in new born baby in Indonesia. According to WHO in 2002, breathing rate is very important index to be the symptom of pneumonia. In the Community Health Center, the nurses count with a stopwatch for exactly one minute. Miscalculation in Community Health Center occurs because of long time concentration and focus on two object at once. This calculation errors can cause the baby who should be admitted to the hospital only be attended at home. Therefore, an accurate breathing rate counter at Community Health Center level is necessary. In this work, resistance change of variable resistor is made to be breathing rate counter. Resistance change in voltage divider can produce voltage change. If the variable resistance moves periodically, the voltage will change periodically too. The voltage change counted by software in the microcontroller. For the every mm shift at the variable resistor produce average 0.96 voltage change. The software can count the number of wave generated by shifting resistor.

  19. DIGITAL DIVIDE

    OpenAIRE

    PRAVEENKUMAR KUMBARGOUDAR

    2013-01-01

    Digital Divide may also be called as Information and Technology gap. In general terms, it is the gap between those who can effectively use new information and communication tools, such as the internet, and those who cannot. The digital divide becomes challenge for the development of digital libraries in India. Because the different factors such as Illiteracy, Poverty, Computer illiteracy, lack of widespread telecommunication facilities, shortage of power supply etc. created the digital divi...

  20. Crossing the divide between homogeneous and heterogeneous catalysis in water oxidation.

    Science.gov (United States)

    Vannucci, Aaron K; Alibabaei, Leila; Losego, Mark D; Concepcion, Javier J; Kalanyan, Ber; Parsons, Gregory N; Meyer, Thomas J

    2013-12-24

    Enhancing the surface binding stability of chromophores, catalysts, and chromophore-catalyst assemblies attached to metal oxide surfaces is an important element in furthering the development of dye sensitized solar cells, photoelectrosynthesis cells, and interfacial molecular catalysis. Phosphonate-derivatized catalysts and molecular assemblies provide a basis for sustained water oxidation on these surfaces in acidic solution but are unstable toward hydrolysis and loss from surfaces as the pH is increased. Here, we report enhanced surface binding stability of a phosphonate-derivatized water oxidation catalyst over a wide pH range (1-12) by atomic layer deposition of an overlayer of TiO2. Increased stability of surface binding, and the reactivity of the bound catalyst, provides a hybrid approach to heterogeneous catalysis combining the advantages of systematic modifications possible by chemical synthesis with heterogeneous reactivity. For the surface-stabilized catalyst, greatly enhanced rates of water oxidation are observed upon addition of buffer bases -H2PO(-)(4)/HPO(2-)(4), B(OH)3/B(OH)2 O-, HPO(2-)4 /PO(3-)(4) - and with a pathway identified in which O-atom transfer to OH(-) occurs with a rate constant increase of 10(6) compared to water oxidation in acid. PMID:24277824

  1. Current controlled variable resistors through superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Lakshmi, M. V. S.; Ramkumar, K.; Satyam, M.

    1989-07-01

    This note attempts to describe a current controlled variable resistor conceived based on the property of critical current associated with a superconductor. This idea has been tested using high-temperature superconductor films.

  2. Current controlled variable resistors through superconductors

    International Nuclear Information System (INIS)

    This note attempts to describe a current controlled variable resistor conceived based on the property of critical current associated with a superconductor. This idea has been tested using high-temperature superconductor films

  3. Liquid resistor for protecting superconducting coil

    International Nuclear Information System (INIS)

    The present invention concerns a protective resistor for attenuating electric current in superconducting coils when they are quenched (normal conduction state) in an external electric circuit of DC-excited immersion cooling-type superconducting coils for use in a thermonuclear device. Namely, the resistor of the present invention has an anode disposed on one side and a cathode disposed on the other side at a predetermined distance. Both of the electrodes are connected by means of a channel having a small cross section. The channel is filled with an electrolyte to form a battery, which constitutes a resistor. This is connected in parallel with superconducting coils of the electric circuit of the immersion cooling-type superconducting coils. Such a protective liquid resistor does not cause bubbling at an electrode plate although DC current is used. In addition, the electrolyte has a characteristic of increasing the conductivity along with temperature elevation. Accordingly, it provides an effect of improving the safety factor of the minimum pressure resistance of the immersion cooling-type superconductive coils compared with a constant resistor or a metal resistor. The safety factor of pressure resistance can be improved with no change in the design of the superconducting coils. (I.S.)

  4. Dividing Discipline

    DEFF Research Database (Denmark)

    Kristensen, Peter Marcus

    2012-01-01

    the periphery of the network—security studies and international political economy in particular—but communication is also divided along the lines of geography and policy/theory. The article concludes that divisions notwithstanding, IR communication remains centered around American, general, and...

  5. Software Development in the Water Sciences: a view from the divide (Invited)

    Science.gov (United States)

    Miles, B.; Band, L. E.

    2013-12-01

    While training in statistical methods is an important part of many earth scientists' training, these scientists often learn the bulk of their software development skills in an ad hoc, just-in-time manner. Yet to carry out contemporary research scientists are spending more and more time developing software. Here I present perspectives - as an earth sciences graduate student with professional software engineering experience - on the challenges scientists face adopting software engineering practices, with an emphasis on areas of the science software development lifecycle that could benefit most from improved engineering. This work builds on experience gained as part of the NSF-funded Water Science Software Institute (WSSI) conceptualization award (NSF Award # 1216817). Throughout 2013, the WSSI team held a series of software scoping and development sprints with the goals of: (1) adding features to better model green infrastructure within the Regional Hydro-Ecological Simulation System (RHESSys); and (2) infusing test-driven agile software development practices into the processes employed by the RHESSys team. The goal of efforts such as the WSSI is to ensure that investments by current and future scientists in software engineering training will enable transformative science by improving both scientific reproducibility and researcher productivity. Experience with the WSSI indicates: (1) the potential for achieving this goal; and (2) while scientists are willing to adopt some software engineering practices, transformative science will require continued collaboration between domain scientists and cyberinfrastructure experts for the foreseeable future.

  6. Design of a Compact Dump Resistor System for LCD Magnet

    CERN Document Server

    Gaddi, A

    2010-01-01

    In this technical note we suggest a possible solution for the choice of the detector magnet dump resistor. The push-pull scenario for Linear Collider Detectors imposes new solutions for magnet powering and protection lines, else than what developed for LHC detectors. The magnet dump resistor is the protecting equipment that has the function of extracting a significant amount of magnetic stored energy, from the coil winding to a dump. The LCD magnet has to move with the experiment from the garage to the beam position, so it has to be compact and reliable at the same time. We make here a proposal for a passive water-cooled dumper, we calculate the minimum amount of water required, the resistor hot-spot temperature, the overall mechanical design. The electrical part is not covered by this note, as it can be assumed that the solutions adopted by LHC detector magnets, in terms of quench instrumentation, energy extraction and maximum voltage, are not significantly affected by the push-pull scenario.

  7. Continental divide

    International Nuclear Information System (INIS)

    The historical precedents to the idea of continent-wide diversion of water in North America are reviewed, starting from early perceptions of continental drainage and the era of canal building that reached its peak in the mid-1800s. The attitude that natural landscapes can be rearranged to suit human needs has persisted from that era with the proposal for continent-wide water diversion megaprojects, many involving the movement of water from Canada to the southwestern USA. Over 50 water diversions exist in Canada, with a total diverted flow of 4,400 m3/s. The density of interconnected and almost-connected lakes and rivers has favored such diversions. Of these diversions, 95% of their storage capacity and 96% of their flow is for hydroelectric power generation. The number of diversions in the USA is similar but water volumes are only a sixth of those in Canada, and the water is mainly used for irrigation or water supply. Experience in both countries shows that diversions are contained by political boundaries. No large-scale diversion of fresh water across the international boundary has received any government support, and no significant change in this policy is anticipated. In the water-short areas of the USA, conservation and reallocation of water resources are receiving priority. 19 refs., 2 figs., 2 tabs

  8. Charge pulse restorer for resistor feedback preamplifiers

    International Nuclear Information System (INIS)

    A simple circuit for cancelling the main pole of traditional resistor feedback preamplifier output signals has been designed. The resultant waveform is a series of step functions equivalent to the output of a pulsed feedback preamplifier. The advantage of such a preamplifier output signal is that its quantized samples can directly be processed by certain digital signal processors. ((orig.))

  9. Suppressing Thermal Energy Drift In The LLNL Flash X-Ray Accelerator Using Linear Disk Resistor Stacks

    International Nuclear Information System (INIS)

    This paper addresses thermal drift in sodium thiosulfate liquid resistors and their replacement with linear disk resistors from HVR Advanced Power Components. Sodium thiosulfate resistors in the FXR induction linear accelerator application have a temperature coefficient of ∼1.8%/C. The FXR Marx banks send an 8kJ pulse through eight 524 cm3 liquid resistors at a repetition rate of up to 1 every 45 seconds. Every pulse increases the temperature of the solution by ∼0.4 C which produces a 0.7% change in resistance. The typical cooling rate is ∼0.4 C per minute which results in ∼0.1% energy drop per pulse during continuous pulsed operations. A radiographic accelerator is extraordinarily sensitive to energy variations. Changes in beam energy produce movement in beam transport, changes in spot size, and large dose variations. If self-heating were the only problem, we could predict the increase in input voltage required to compensate for the energy loss. However, there are other variables that influence the temperature of the resistors such as focus magnet heating, changes in room temperature, changes in cooling water, where the cell is located, etc. Additionally not all of the resistors have equivalent cooling rates and as many as 32 resistors are driven from a single power source. The FXR accelerator group elected to replace the sodium thiosulfate resistors with HVR Linear Disk Resistors in a stack type configuration. With data limited for these resistors when used in oil and at low resistance values, a full characterization needed to be performed. High currents (up to 15kA), high voltages (up to 400kV), and Fast Rise times (<10ns) made a resistor choice difficult. Other solid resistors have been tried and had problems at the connection points and with the fact that the resistivity changed as they absorbed oil. The selected HVR resistors have the advantage of being manufactured with the oil impregnated in to them so this characteristic is minimized while still offering the desired low temperature coefficient of resistance compared to sodium thiosulfate. The characterization experiments and comparison with the sodium thiosulfate liquid resistors will be fully discussed and the final design described.

  10. Predicted effects on ground water of construction of Divide Cut section, Tennessee-Tombigbee Waterway, northeastern Mississippi, using a digital model

    Science.gov (United States)

    McBride, Mark S.

    1981-01-01

    The Tennessee-Tombigbee Waterway, connecting the Tennessee River in northeastern Mississippi with the Gulf of Mexico, is currently (1980) under construction. The Divide Section, the northernmost 39 miles of the Waterway, will consist, from north to south, of (1) a dredged channel, (2) the Divide Cut, and (3) an artifical lake impounded by the Bay Springs Dam. In all three , water will be at Tennessee River level. A three-dimensional digital model covering 3,273 square miles was constructed to simulate ground-water flow in the Gordo and Eutaw Formations and the Coffee Sand in the vicinity of the Divide Section. The model was calibrated to preconstruction water levels, then used to simulate the effects of stresses imposed by the construction of the Divide Section. The model indicates that the system stabilizes after major changes in conditions within a few months. The Divide Cut acts as a drain, lowering water levels as much as 55 feet. Drawdowns of 5 feet occur as much as 8 miles from the Cut. The 80-foot-high Bay Springs Dam raises ground-water levels by 5 feet as far as 6 miles from its impoundment. Drawdown is not likely to affect public water supplies significantly, but probably will adversely affect a relatively small number of private wells. (USGS)

  11. Study of thin-film resistor resistance error

    Directory of Open Access Journals (Sweden)

    Spirin V. G.

    2009-10-01

    Full Text Available A relationship between a thin-film resistor resistance error and mask misalignment with a substrate conductive layer at the second photolithography stage for a thin-film resistor design in which the resistive element does not overlap conductor pads is studied. The error value is at a maximum when the resistor aspect ratio is equal to 1.0.

  12. Rational and irrational numbers from unit resistors

    International Nuclear Information System (INIS)

    We address the problem of constructing a network of unit resistors such that it enables the retrieval of an arbitrary value of equivalent resistance. In particular, we employ the notion of continued fractions to construct a ladder network by which we can easily obtain any fractional value resistance. In addition, since any irrational number is associated with an infinite continued fraction, we discuss the convergence of the equivalent resistance of an infinite resistive ladder and various aspects concerning the approximations of arbitrary numbers attained by adding additional resistors successively to the network. The presented methods can be easily implemented in an educational laboratory and offer an interesting addition to the topic of Ohm’s law. (paper)

  13. Effects of surfaces on resistor percolation

    CERN Document Server

    Stenull, O; Oerding, K; Stenull, Olaf; Janssen, Hans-Karl; Oerding, Klaus

    2001-01-01

    We study the effects of surfaces on resistor percolation at the instance of a semi-infinite geometry. Particularly we are interested in the average resistance between two connected ports located on the surface. Based on general grounds as symmetries and relevance we introduce a field theoretic Hamiltonian for semi-infinite random resistor networks. We show that the surface contributes to the average resistance only in terms of corrections to scaling. These corrections are governed by surface resistance exponents. We carry out renormalization group improved perturbation calculations for the special and the ordinary transition. We calculate the surface resistance exponents $\\phi_{\\mathcal S \\mathnormal}$ and $\\phi_{\\mathcal S \\mathnormal}^\\infty$ for the special and the ordinary transition, respectively, to one-loop order.

  14. Braking Resistor Scheme for Transient Stability Improvement

    Directory of Open Access Journals (Sweden)

    Saeed Abazari

    2007-09-01

    Full Text Available One of the most important problems in power systems design is increasing the damping of the swing amplitude and also to increase the critical time in transient stability. One of the best techniques is to use resistor braking. However, their performance in power systems, duration of their activity and their place of installation are of great importance. In this paper by using of some of devices in power electronics and by precies modeling of the network and optimal controller is designed which leads as to our final objective. In fact resistor braking are effectively attract additive energy which is a result of disturbances and help us to improve the stability of overall system.

  15. Resistor Networks based on Symmetrical Polytopes

    Directory of Open Access Journals (Sweden)

    Jeremy Moody

    2015-03-01

    Full Text Available This paper shows how a method developed by Van Steenwijk can be generalized to calculate the resistance between any two vertices of a symmetrical polytope all of whose edges are identical resistors. The method is applied to a number of cases that have not been studied earlier such as the Archimedean polyhedra and their duals in three dimensions, the regular polytopes in four dimensions and the hypercube in any number of dimensions.

  16. Renormalized field theory of resistor diode percolation

    CERN Document Server

    Stenull, O; Stenull, Olaf; Janssen, Hans-Karl

    2001-01-01

    We study resistor diode percolation at the transition from the non-percolating to the directed percolating phase. We derive a field theoretic Hamiltonian which describes not only geometric aspects of directed percolation clusters but also their electric transport properties. By employing renormalization group methods we determine the average two-port resistance of critical clusters, which is governed by a resistance exponent $\\phi$. We calculate $\\phi$ to two-loop order.

  17. Braking Resistor Scheme for Transient Stability Improvement

    OpenAIRE

    Saeed Abazari

    2007-01-01

    One of the most important problems in power systems design is increasing the damping of the swing amplitude and also to increase the critical time in transient stability. One of the best techniques is to use resistor braking. However, their performance in power systems, duration of their activity and their place of installation are of great importance. In this paper by using of some of devices in power electronics and by precies modeling of the network and optimal controller is designed which...

  18. Describing Hopping by Nonlinear Resistor Networks

    Science.gov (United States)

    Kinkhabwala, Yusuf; Sverdlov, Viktor; Korotkov, Alexander; Likharev, Konstantin

    2003-03-01

    From the pioneering work by Miller and Abrahams, the model of equivalent resistor network was an important tool for discussion of variable range hopping. However, we are not aware of any quantitative comparison between the exact analysis of this problem and predictions based on the Miller-Abrahams model. We have carried out such a comparison for random 2D systems (without Coulomb interactions), using Monte Carlo simulations, within a broad range of temperature and electric field. The equivalent network of (generally, nonlinear) resistors has been constructed for each random system by determining the effective electrochemical potential, and average currents flowing in and out of each localized site. The system of equations describing Kirchoff's laws for this network was solved numerically. Except for rare occurrences in very small systems, the results for linear conductivity coincide in both techniques within their accuracy. At the same time, the resistor network approach requires much less computer time and has allowed us to access much lower temperatures than we could reach by Monte Carlo simulations. The comparison of these two methods for the nonlinear case is in progress.

  19. Shunt switched resistor regulator with diode snubber

    Energy Technology Data Exchange (ETDEWEB)

    Ekstrand, J.

    1989-03-21

    This patent describes a shunt switched resistor regulator power supply for supplying a variable amount of power to a load comprising: a rectifier means for accepting AC input voltage and converting it to DC output voltage at a positive and a negative terminal; first, second, third, and fourth nodes wherein the first and the fourth nodes are coupled to the positive and negative terminals, respectively; a current limiting resistor coupled between the first and second nodes; a capacitor coupled between the second and fourth nodes; a resistor having parasitic inductance coupled between the second and third nodes; a switch coupled between the third and fourth nodes; and a diode having its anode coupled to the third node and having its cathode coupled to the second node; means coupled to the load terminals for sensing the power being delivered to the load and for controlling the switch to have a duty cycle which results in the desired load current flowing through and a desired voltage appearing across the load in accordance with control input signals received at a control input.

  20. Studies of tantalum nitride thin film resistors

    International Nuclear Information System (INIS)

    Backscattering of 2-MeV He ions was used to correlate the electrical properties of sputtered TaN/sub x/ thin-film resistors with their N content. The properties measured were sheet resistance, differential Seebeck potential (DSP), thermal coefficient of resistance (TCR), and stability. Resistivity and DSP are linearly dependent on N content for N/Ta ratios of 0.25 to 0.55. TCR decreases sharply below N/Ta = 0.35 and is relatively constant from 0.35 to 0.55. Stability is independent of N content. (DLC)

  1. Dynamic analysis on the closing resistors of Gas Insulated Switchgear

    International Nuclear Information System (INIS)

    GIS (Gas Insulated Switchgear) is used in electric power system to insure non conductivity, breaking capacity and operating reliability. In the present study, dynamic analysis on the closing resistors of the GIS has bees carried out by the commercial dynamic analysis code COSMOS MOTION and 3-D modeling program SOLID WORKS. In order to find the minimum value of chatter vibration of closing resistors, the motion of moving and fixed resistor parts of closing resistors were simulated by varying the spring constant, the damping coefficient and the mass of moving and fixed resistor parts. The simulated results were compared with experimental results. The application of the results could reduce chatter vibration of closing resistors of the GIS. These data are also useful on the development of future model GIS with minimum chatter vibration for the determinations of the spring constant, the damping coefficient and mass of a moving part

  2. Modeling of three-dimensional diffusible resistors with the one-dimensional tube multiplexing method

    International Nuclear Information System (INIS)

    Electronic-behavior modeling of three-dimensional (3D) p+-?-p+ and n+-?-n+ semiconducting diffusible devices with highly accurate resistances for the design of analog resistors, which are compatible with the CMOS (complementary-metal-oxide-semiconductor) technologies, is performed in three dimensions with the fast tube multiplexing method (TMM). The currentvoltage (IV) curve of a silicon device is usually computed with traditional device simulators of technology computer-aided design (TCAD) based on the finite-element method (FEM). However, for the design of 3D p+-?-p+ and n+-?-n+ diffusible resistors, they show a high computational cost and convergence that may fail with fully non-separable 3D dopant concentration profiles as observed in many diffusible resistors resulting from laser trimming. These problems are avoided with the proposed TMM, which divides the 3D resistor into one-dimensional (1D) thin tubes with longitudinal axes following the main orientation of the average electrical field in the tubes. The IV curve is rapidly obtained for a device with a realistic 3D dopant profile, since a system of three first-order ordinary differential equations has to be solved for each 1D multiplexed tube with the TMM instead of three second-order partial differential equations in the traditional TCADs. Simulations with the TMM are successfully compared to experimental results from silicon-based 3D resistors fabricated by laser-induced dopant diffusion in the gaps of MOSFETs (metal-oxide-semiconductor field-effect transistors) without initial gate. Using thin tubes with other shapes than parallelepipeds as ring segments with toroidal lateral surfaces, the TMM can be generalized to electronic devices with other types of 3D diffusible microstructures

  3. A high Tc superconducting loss-free resistor

    International Nuclear Information System (INIS)

    Full text: A loss-less resistor (LLR) is introduced as a novel concept with consideration of using a high Tc superconducting (HTS) inductor. This LLR resistor mainly consists of an electronic switch bridge and a inductor L. By controlling the electronic switch bridge, an equivalent resistance R(i) can be generated, and its value is R(i) = (L/i)di/dt, which allows the LLR resistor have a resistive voltage-current characteristic i.e. V(t) = i(t)R, but without thermal loss across this LLR resistor if a superconducting inductor is selected. With a HTS winding and therefore a HTS inductor, this LLR resistor is practically close to loss-free. The LLR resistor can be widely used to replace the conventional resistor in order to save energy and to improve performance of the systems. The HTS wires are identified for this application, by considering their critical currents, ac loss and possibility to make a large HTS inductor winding. To make LLR resistors for practical applications is considered with the existing HTS wires

  4. Design of versatile printed organic resistor based on resistivity ( ?) control

    Science.gov (United States)

    Ali, Shawkat; Bae, Jinho; Lee, Chong Hyun

    2015-06-01

    We demonstrate the design and fabrication of a printed organic resistor based on resistivity ( ?) control method. Two types of resistor are reported by utilizing three types of material poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate), poly(methyl methacrylate), and silver (Ag) nano-particles. Materials are blended for the required value of resistivity ( ?), to overcome the size and resistance value constraints of the printed resistors. The design function ?( x) is also proposed to estimate the required resistivity value, and this function is obtained from the measured resistivity and mixing ratio of materials. The proposed resistivity design function is verified by comparing measured and theoretical estimated values of the resistivity. The resistors are fabricated on polyethylene terephthalate substrate through electro-hydrodynamic technique. The proposed two types of organic resistors are electrically and mechanically characterized by using various methods of their current-voltage ( I- V) relation analysis, endurance time, bendability, heating temperature analysis, and frequency response.

  5. The Sponge Resistor Model — A Hydrodynamic Analog to Illustrate Ohm's Law, the Resistor Equation R =ρℓ/A, and Resistors in Series and Parallel

    Science.gov (United States)

    Pfister, Hans

    2014-05-01

    Physics students encountering electric circuits for the first time often ask why adding more resistors to a circuit sometimes increases and sometimes decreases the resulting total resistance. It appears that these students have an inadequate understanding of current flow and resistance. Students who do not adopt a model of current, voltage, and resistance necessarily resort to memorizing formulas for calculating, e.g., the resistance of a resistor network. For these students, certain properties of electric circuits may remain mysterious or puzzling.

  6. Divide-and-Conquer-Type Density-Functional Tight-Binding Molecular Dynamics Simulations of Proton Diffusion in a Bulk Water System.

    Science.gov (United States)

    Nakai, Hiromi; Sakti, Aditya Wibawa; Nishimura, Yoshifumi

    2016-01-14

    The process of proton diffusion in liquid water was investigated using molecular dynamics (MD) simulations, and the total energy and atomic forces were evaluated by the divide-and-conquer-type density-functional tight-binding (DC-DFTB) method. The effectiveness of this approach was confirmed by comparing the computational time of water clusters with conventional treatments. The unit cell employed herein, which contained 523 water molecules and 1 excess proton, was moderately large in comparison with those used in previous studies. The reasonable accuracy obtained by using this unit cell was confirmed by examining the temperature fluctuation. The diffusion coefficients for the vehicular and Grotthuss processes were accurately reproduced by the DC-DFTB-MD simulations with the unit cell containing 523 water molecules. Furthermore, the energy barriers were evaluated from the temperature dependence of the diffusion coefficient for each process. The calculated barrier for Grotthuss diffusion was in good agreement with the experimental value. PMID:26694784

  7. Room-temperature antiferromagnetic memory resistor

    Science.gov (United States)

    Marti, X.; Fina, I.; Frontera, C.; Liu, Jian; Wadley, P.; He, Q.; Paull, R. J.; Clarkson, J. D.; Kudrnovský, J.; Turek, I.; Kuneš, J.; Yi, D.; Chu, J.-H.; Nelson, C. T.; You, L.; Arenholz, E.; Salahuddin, S.; Fontcuberta, J.; Jungwirth, T.; Ramesh, R.

    2014-04-01

    The bistability of ordered spin states in ferromagnets provides the basis for magnetic memory functionality. The latest generation of magnetic random access memories rely on an efficient approach in which magnetic fields are replaced by electrical means for writing and reading the information in ferromagnets. This concept may eventually reduce the sensitivity of ferromagnets to magnetic field perturbations to being a weakness for data retention and the ferromagnetic stray fields to an obstacle for high-density memory integration. Here we report a room-temperature bistable antiferromagnetic (AFM) memory that produces negligible stray fields and is insensitive to strong magnetic fields. We use a resistor made of a FeRh AFM, which orders ferromagnetically roughly 100 K above room temperature, and therefore allows us to set different collective directions for the Fe moments by applied magnetic field. On cooling to room temperature, AFM order sets in with the direction of the AFM moments predetermined by the field and moment direction in the high-temperature ferromagnetic state. For electrical reading, we use an AFM analogue of the anisotropic magnetoresistance. Our microscopic theory modelling confirms that this archetypical spintronic effect, discovered more than 150 years ago in ferromagnets, is also present in AFMs. Our work demonstrates the feasibility of fabricating room-temperature spintronic memories with AFMs, which in turn expands the base of available magnetic materials for devices with properties that cannot be achieved with ferromagnets.

  8. Hybrid optical antennas with photonic resistors.

    Science.gov (United States)

    Butakov, N A; Schuller, J A

    2015-11-16

    Hybrid optical antennas, comprising active materials placed in the gaps of plasmonic split-ring-resonators and nano-dimers, have been the subject of numerous recent investigations. Engineered coupling between the two plasmonic resonators is achieved by modulating the active material, enabling control over the near- and far-field electromagnetic properties. Here, using electromagnetics calculations, we study the evolving optical response of a hybrid metal-semiconductor-metal nanorod antenna as the semiconductor free charge carrier density is continuously varied. In particular, we demonstrate qualitatively new behavior arising from epsilon-near-zero properties in intermediately doped semiconductors. In agreement with optical nano-circuit theory, we show that in the epsilon-near-zero regime such a load acts as an ideal optical resistor with an optimized damping response and strongly suppressed electromagnetic scattering. In periodic arrays, or metasurfaces, we then show how to use these effects to construct high-efficiency nanophotonic intensity modulators for dynamically shaping light. PMID:26698451

  9. NuMI proton kicker extraction magnet termination resistor system

    Energy Technology Data Exchange (ETDEWEB)

    Reeves, S.R.; Jensen, C.C.; /Fermilab

    2005-05-01

    The temperature stability of the kicker magnet termination resistor assembly directly affects the field flatness and amplitude stability. Comprehensive thermal enhancements were made to the existing Main Injector resistor assembly design to satisfy NuMI performance specifications. Additionally, a fluid-processing system utilizing Fluorinert{reg_sign} FC-77 high-voltage dielectric was built to precisely control the setpoint temperature of the resistor assembly from 70 to 120F, required to maintain constant resistance during changing operational modes. The Fluorinert{reg_sign} must be continually processed to remove hazardous breakdown products caused by radiation exposure to prevent chemical attack of system components. Design details of the termination resistor assembly and Fluorinert{reg_sign} processing system are described. Early performance results will be presented.

  10. Irreversible entropy model for damage diagnosis in resistors

    Science.gov (United States)

    Cuadras, Angel; Crisóstomo, Javier; Ovejas, Victoria J.; Quilez, Marcos

    2015-10-01

    We propose a method to characterize electrical resistor damage based on entropy measurements. Irreversible entropy and the rate at which it is generated are more convenient parameters than resistance for describing damage because they are essentially positive in virtue of the second law of thermodynamics, whereas resistance may increase or decrease depending on the degradation mechanism. Commercial resistors were tested in order to characterize the damage induced by power surges. Resistors were biased with constant and pulsed voltage signals, leading to power dissipation in the range of 4-8 W, which is well above the 0.25 W nominal power to initiate failure. Entropy was inferred from the added power and temperature evolution. A model is proposed to understand the relationship among resistance, entropy, and damage. The power surge dissipates into heat (Joule effect) and damages the resistor. The results show a correlation between entropy generation rate and resistor failure. We conclude that damage can be conveniently assessed from irreversible entropy generation. Our results for resistors can be easily extrapolated to other systems or machines that can be modeled based on their resistance.

  11. An air-cooled gradient resistor column for the KFUPM 350 kV ion accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Raashid, M. [King Fahd Univ. of Petroleum and Minerals, Dhahran (Saudi Arabia). Energy Res. Lab.; Abdel-Aal, R.E. [King Fahd Univ. of Petroleum and Minerals, Dhahran (Saudi Arabia). Energy Res. Lab.; Naqvi, A.A. [King Fahd Univ. of Petroleum and Minerals, Dhahran (Saudi Arabia). Energy Res. Lab.; Al-Ohali, M.A. [King Fahd Univ. of Petroleum and Minerals, Dhahran (Saudi Arabia). Energy Res. Lab.; Nagadi, M.M. [King Fahd Univ. of Petroleum and Minerals, Dhahran (Saudi Arabia). Energy Res. Lab.

    1996-08-21

    An air-cooled gradient resistor column has been designed and implemented for the KFUPM 350 kV ion accelerator. The air-cooled column overcomes operational limitations on the acceleration voltages obtained with the old water-cooled column and improves on reliability and maintainability. The new column consists of five sections, each having sixteen 8 M{Omega} 15 W resistors connected in a series-parallel combination. Corona shields defining equipotential circular planes have been incorporated to maintain a uniform potential difference across the column sections. In order to protect the gradient column and accelerator tube against arcing, spark gaps are provided on each corona shield. The new column has been tested over the full range of 0-320 kV across the accelerator tube for extended durations without arcing. Both electrical and mechanical aspects of the new design are discussed, measurement techniques used during installation and testing are described, and performance data are given. (orig.).

  12. Continental Divide Trail

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This shapefile was created to show the proximity of the Continental Divide to the Continental Divide National Scenic Trail in New Mexico. This work was done as part...

  13. Noise characteristics of resistors buried in low-temperature co-fired ceramics

    International Nuclear Information System (INIS)

    The comparison of noise properties of conventional thick film resistors prepared on alumina substrates and resistors embedded in low-temperature co-fired ceramics (LTCCs) is presented. Both types of resistors were prepared from commercially available resistive inks. Noise measurements of LTCC resistors below 1 kHz show Gaussian 1/f noise. This is concluded from the calculations of the second spectra as well as from studying the volume dependence of noise intensity. It has occurred that noise index of LTCC resistors on average is not worse than that of conventional resistors. A detailed study of co-fired surface resistors and co-fired buried resistors show that burying a resistor within LTCC substrate usually leads to (significant) enhancement of resistance but not of noise intensity. We interpret this behaviour as another argument in favour of tunnelling as the dominant conduction mechanism in LTCC resistors

  14. Noise characteristics of resistors buried in low-temperature co-fired ceramics

    CERN Document Server

    Kolek, A; Dziedzic, A

    2003-01-01

    The comparison of noise properties of conventional thick film resistors prepared on alumina substrates and resistors embedded in low-temperature co-fired ceramics (LTCCs) is presented. Both types of resistors were prepared from commercially available resistive inks. Noise measurements of LTCC resistors below 1 kHz show Gaussian 1/f noise. This is concluded from the calculations of the second spectra as well as from studying the volume dependence of noise intensity. It has occurred that noise index of LTCC resistors on average is not worse than that of conventional resistors. A detailed study of co-fired surface resistors and co-fired buried resistors show that burying a resistor within LTCC substrate usually leads to (significant) enhancement of resistance but not of noise intensity. We interpret this behaviour as another argument in favour of tunnelling as the dominant conduction mechanism in LTCC resistors.

  15. The Sponge Resistor Model--A Hydrodynamic Analog to Illustrate Ohm's Law, the Resistor Equation R=?l/A, and Resistors in Series and Parallel

    Science.gov (United States)

    Pfister, Hans

    2014-01-01

    Physics students encountering electric circuits for the first time often ask why adding more resistors to a circuit sometimes increases and sometimes decreases the resulting total resistance. It appears that these students have an inadequate understanding of current flow and resistance. Students who do not adopt a model of current, voltage, and

  16. Experimental study of Evanohm thin film resistors at subkelvin temperatures

    International Nuclear Information System (INIS)

    Thin film resistors, based on the Evanohm (Ni75%Cr20%Cu2.5%Al2.5%) alloy, have been investigated at cryogenic temperatures. The objective of the study is the development of the high value resistor for precision electrical measurements at low temperature and particularly for metrological triangle experiments. Thin film resistors of different configurations have been designed and fabricated by the thermal evaporation process. The resistivity of investigated resistors is 110 × 10−8 Ω m; the resistance exhibits a Kondo minimum at a temperature near 30 K and increases with further reduction of temperature. In the temperature range 50–65 mK, the temperature coefficient reaches −20 × 10−3 K−1. Power dependence measurements at subkelvin temperatures demonstrate that noticeable electron overheating takes place only at the power level above 10 pW for a 500 kΩ resistor. The electron–phonon coupling constant for the fabricated Evanohm thin films has been derived from experimental results

  17. Surface scattering mechanisms of tantalum nitride thin film resistor

    Science.gov (United States)

    Chen, Huey-Ru; Chen, Ying-Chung; Chang, Ting-Chang; Chang, Kuan-Chang; Tsai, Tsung-Ming; Chu, Tian-Jian; Shih, Chih-Cheng; Chuang, Nai-Chuan; Wang, Kao-Yuan

    2014-04-01

    In this letter, we utilize an electrical analysis method to develop a TaN thin film resistor with a stricter spec and near-zero temperature coefficient of resistance (TCR) for car-used electronic applications. Simultaneously, we also propose a physical mechanism mode to explain the origin of near-zero TCR for the TaN thin film resistor (TFR). Through current fitting, the carrier conduction mechanism of the TaN TFR changes from hopping to surface scattering and finally to ohmic conduction for different TaN TFRs with different TaN microstructures. Experimental data of current-voltage measurement under successive increasing temperature confirm the conduction mechanism transition. A model of TaN grain boundary isolation ability is eventually proposed to influence the carrier transport in the TaN thin film resistor, which causes different current conduction mechanisms.

  18. TI--CR--AL--O thin film resistors

    Science.gov (United States)

    Jankowski, Alan F.; Schmid, Anthony P.

    2000-01-01

    Thin films of Ti--Cr--Al--O are used as a resistor material. The films are rf sputter deposited from ceramic targets using a reactive working gas mixture of Ar and O.sub.2. Resistivity values from 10.sup.4 to 10.sup.10 Ohm-cm have been measured for Ti--Cr--Al--O film Ti--Cr--Al--O as a thin film resistor has been found to be thermodynamically stable, unlike other metal-oxide films. The Ti--Cr--Al--O film can be used as a vertical or lateral resistor, for example, as a layer beneath a field emission cathode in a flat panel display; or used to control surface emissivity, for example, as a coating on an insulating material such as vertical wall supports in flat panel displays.

  19. Refractory resistors with etch stop for superconductor integrated circuits

    International Nuclear Information System (INIS)

    This patent describes a method for preparing molybdenum resistors in a superconductor integrated circuit. It comprises: depositing superconductor film on a support; patterning the superconductor film to provide a patterned superconductor and exposed support; applying an aluminum film on the superconductor film and the exposed support; applying a molybdenum film on the aluminum film to provide an aluminum-molybdenum, etch-stop interface; applying a patterned resist film on the molybdenum film to provide exposed molybdenum film and unexposed molybdenum film; etching the exposed molybdenum film to define the molybdenum resistor and expose a portion of the aluminum-molybdenum, etch-stop interface; and oxidizing the exposed aluminum-molybdenum, etch-stop interface. The aluminum-molybdenum, etch-stop interface protects the patterned superconductor film and the support and increases processing margins for the etch time. Also described is a molybdenum resistor configuration for a superconductor integrated circuit

  20. Surface scattering mechanisms of tantalum nitride thin film resistor.

    Science.gov (United States)

    Chen, Huey-Ru; Chen, Ying-Chung; Chang, Ting-Chang; Chang, Kuan-Chang; Tsai, Tsung-Ming; Chu, Tian-Jian; Shih, Chih-Cheng; Chuang, Nai-Chuan; Wang, Kao-Yuan

    2014-01-01

    In this letter, we utilize an electrical analysis method to develop a TaN thin film resistor with a stricter spec and near-zero temperature coefficient of resistance (TCR) for car-used electronic applications. Simultaneously, we also propose a physical mechanism mode to explain the origin of near-zero TCR for the TaN thin film resistor (TFR). Through current fitting, the carrier conduction mechanism of the TaN TFR changes from hopping to surface scattering and finally to ohmic conduction for different TaN TFRs with different TaN microstructures. Experimental data of current-voltage measurement under successive increasing temperature confirm the conduction mechanism transition. A model of TaN grain boundary isolation ability is eventually proposed to influence the carrier transport in the TaN thin film resistor, which causes different current conduction mechanisms. PMID:24725295

  1. Design of a convection-cooled, cluster-based voltage divider chain for photomultiplier tubes

    Science.gov (United States)

    Gu, Xi Bin; Guo, Ying; Kawamura, Ed; Kaiser, Ralf I.

    2005-08-01

    A highly stable convection-cooled, cluster-based voltage divider chain for photomultiplier tubes has been designed and tested in single ion counting detection systems. Contrasting currently existing voltage divider chains, our unit does not require a cooling liquid to transfer the heat from the resistors and provides safer operation conditions inside ultrahigh vacuum systems utilized in the reaction dynamics community. The unit is enclosed in an air pocket inside an ultrahigh vacuum system so that outgassing of the photomultiplier tubes, resistors, and capacitors can be eliminated completely. The measured resistor chain currents of ±2% lie well within the tolerances of the resistors (±5%) and power supply (±1%) demonstrating that the convective cooling is actually efficient to sustain a stable signal. The monitored total ion current also depicts extremely low fluctuation of only 1.5%. The day-to-day reproducibility has been tested, too. We also demonstrate that a magnetic shielding of the photomultiplier tube and the resistor chain enhances the signal by about 15%.

  2. Surface scattering mechanisms of tantalum nitride thin film resistor

    OpenAIRE

    Chen, Huey-Ru; Chen, Ying-Chung; Chang, Ting-Chang; Chang, Kuan-Chang; Tsai, Tsung-Ming; Chu, Tian-Jian; Shih, Chih-Cheng; Chuang, Nai-Chuan; Wang, Kao-Yuan

    2014-01-01

    In this letter, we utilize an electrical analysis method to develop a TaN thin film resistor with a stricter spec and near-zero temperature coefficient of resistance (TCR) for car-used electronic applications. Simultaneously, we also propose a physical mechanism mode to explain the origin of near-zero TCR for the TaN thin film resistor (TFR). Through current fitting, the carrier conduction mechanism of the TaN TFR changes from hopping to surface scattering and finally to ohmic conduction for ...

  3. Ti-Cr-Al-O Thin Film Resistors

    Energy Technology Data Exchange (ETDEWEB)

    Jankowski, A F; Hayes, J P

    2002-03-21

    Thin films of Ti-Cr-Al-O are produced for use as an electrical resistor material. The films are rf sputter deposited from ceramic targets using a reactive working gas mixture of Ar and O{sub 2}. Vertical resistivity values from 10{sup 4} to 10{sup 10} Ohm-cm are measured for Ti-Cr-Al-O films. The film resistivity can be design selected through control of the target composition and the deposition parameters. The Ti-Cr-Al-O thin film resistor is found to be thermally stable unlike other metal-oxide films.

  4. A generalised formulation of the Laplacian approach to resistor networks

    International Nuclear Information System (INIS)

    An analytic approach is presented to developing exact expressions for the two-point resistance between arbitrary nodes on certain non-regular resistor networks. This generalises previous approaches, which only deliver results for networks of more regular geometry. The new approach exploits the second minor of the Laplacian matrix associated with the given network to obtain the resistance in terms of its eigenvalues and eigenvectors. The method is illustrated by application to the resistor network on the globe lattice, for which the resistance between two arbitrary nodes is obtained in the form of single summation. (paper)

  5. Bridging the Digital Divide.

    Science.gov (United States)

    Kelly, Michael C.

    2003-01-01

    Seeks to heighten awareness of the "digital divide" in the TRIO community, enumerating its implications for projects and participants, providing data on one Talent Search project's experience, and outlining some general plans for conquering the divide in the TRIO community. (EV)

  6. Electrochemical Migration on Electronic Chip Resistors in Chloride Environments

    DEFF Research Database (Denmark)

    Minzari, Daniel; Jellesen, Morten Stendahl; Møller, Per; Wahlberg, Pia; Ambat, Rajan

    2009-01-01

    alloy. Anodic polarization behavior of the electrode materials was investigated using a microelectrochemical setup. Material makeup of the chip resistor was investigated using scanning electron microscopy (SEM)/energy dispersive spectroscopy and focused-ion-beam SEM. Results showed that the dissolution...

  7. The great technological divide

    OpenAIRE

    Mudur, Ganapati

    2004-01-01

    Whereas some hospitals and medical schools are introducing telemedicine networks and computer assisted learning, health clinics elsewhere do not even have the facilities to carry out a caesarean section. Ganapati Mudur sees a digital divide opening up in South Asia

  8. Reconceptualizing the Digital Divide

    OpenAIRE

    Warschauer, Mark

    2002-01-01

    This paper examines the concept of a digital divide by introducing problematic examples of community technology projects and analyzing models of technology access. It argues that the concept provides a poor framework for either analysis or policy, and suggests an alternate concept of technology for social inclusion. It then draws on the historical analogy of literacy to further critique the notion of a divide and to examine the resources necessary to promote access and social inclusion.

  9. The Open Access Divide

    OpenAIRE

    Jingfeng Xia

    2013-01-01

    This paper is an attempt to review various aspects of the open access divide regarding the difference between those academics who support free sharing of data and scholarly output and those academics who do not. It provides a structured description by adopting the Ws doctrines emphasizing such questions as who, what, when, where and why for information-gathering. Using measurable variables to define a common expression of the open access divide, this study collects aggregated data from existi...

  10. The Open Access Divide

    Directory of Open Access Journals (Sweden)

    Jingfeng Xia

    2013-10-01

    Full Text Available This paper is an attempt to review various aspects of the open access divide regarding the difference between those academics who support free sharing of data and scholarly output and those academics who do not. It provides a structured description by adopting the Ws doctrines emphasizing such questions as who, what, when, where and why for information-gathering. Using measurable variables to define a common expression of the open access divide, this study collects aggregated data from existing open access as well as non-open access publications including journal articles and extensive reports. The definition of the open access divide is integrated into the discussion of scholarship on a larger scale.

  11. An integrated power divider implemented in GaAs technology

    International Nuclear Information System (INIS)

    A compact lumped integrated power divider with low insertion loss using 0.5 μm GaAs pHEMT technology is presented. The proposed power divider uses the π-type LC network for transmission line equivalence and a thin film resistor for isolation tuning simultaneously. The quality factor of the inductor is analyzed and synthesized for insertion-loss influence. The measured insertion loss is less than 0.5 dB when the operating frequency is within the range of 5.15–6.15 GHz. The return loss and isolation are better than 15 dB and 20 dB, respectively. The compact dimension of the power divider is as small as 0.9 × 0.85 mm2. The measured results agree well with the simulated ones. (semiconductor integrated circuits)

  12. Ultra-high-ohmic microstripline resistors for Coulomb blockade devices

    Science.gov (United States)

    Lotkhov, Sergey V.

    2013-06-01

    In this paper, we report on the fabrication and low-temperature characterization of ultra-high-ohmic microstripline resistors made of a thin film of weakly oxidized titanium. Nearly linear voltage-current characteristics were measured at temperatures down to T ˜ 20 mK for films with sheet resistivities as high as ˜7 kΩ, i.e. about an order of magnitude higher than our previous findings for weakly oxidized Cr. Our analysis indicates that such an improvement can help to create an advantageous high-impedance environment for different Coulomb blockade devices. Further properties of the Ti film addressed in this work show the promise of low-noise behavior of the resistors when applied in different realizations of the quantum standard of current.

  13. Ultra-high-ohmic microstripline resistors for Coulomb blockade devices.

    Science.gov (United States)

    Lotkhov, Sergey V

    2013-06-14

    In this paper, we report on the fabrication and low-temperature characterization of ultra-high-ohmic microstripline resistors made of a thin film of weakly oxidized titanium. Nearly linear voltage-current characteristics were measured at temperatures down to T ~ 20 mK for films with sheet resistivities as high as ~7 kΩ, i.e. about an order of magnitude higher than our previous findings for weakly oxidized Cr. Our analysis indicates that such an improvement can help to create an advantageous high-impedance environment for different Coulomb blockade devices. Further properties of the Ti film addressed in this work show the promise of low-noise behavior of the resistors when applied in different realizations of the quantum standard of current. PMID:23670293

  14. Ultra-high-ohmic microstripline resistors for Coulomb blockade devices

    International Nuclear Information System (INIS)

    In this paper, we report on the fabrication and low-temperature characterization of ultra-high-ohmic microstripline resistors made of a thin film of weakly oxidized titanium. Nearly linear voltage–current characteristics were measured at temperatures down to T ∼ 20 mK for films with sheet resistivities as high as ∼7 kΩ, i.e. about an order of magnitude higher than our previous findings for weakly oxidized Cr. Our analysis indicates that such an improvement can help to create an advantageous high-impedance environment for different Coulomb blockade devices. Further properties of the Ti film addressed in this work show the promise of low-noise behavior of the resistors when applied in different realizations of the quantum standard of current. (paper)

  15. Functional Laser Trimming Of Thin Film Resistors On Silicon ICs

    Science.gov (United States)

    Mueller, Michael J.; Mickanin, Wes

    1986-07-01

    Modern Laser Wafer Trimming (LWT) technology achieves exceptional analog circuit performance and precision while maintain-ing the advantages of high production throughput and yield. Microprocessor-driven instrumentation has both emphasized the role of data conversion circuits and demanded sophisticated signal conditioning functions. Advanced analog semiconductor circuits with bandwidths over 1 GHz, and high precision, trimmable, thin-film resistors meet many of todays emerging circuit requirements. Critical to meeting these requirements are optimum choices of laser characteristics, proper materials, trimming process control, accurate modeling of trimmed resistor performance, and appropriate circuit design. Once limited exclusively to hand-crafted, custom integrated circuits, designs are now available in semi-custom circuit configurations. These are similar to those provided for digital designs and supported by computer-aided design (CAD) tools. Integrated with fully automated measurement and trimming systems, these quality circuits can now be produced in quantity to meet the requirements of communications, instrumentation, and signal processing markets.

  16. Firing, quenching and annealing studies on thick-film resistors

    OpenAIRE

    Vionnet Menot, Sonia; Maeder, Thomas; Ryser, Peter

    2004-01-01

    In this work, we aim to understand the firing behaviour of three representative thick-film resistor compositions used in force and pressure sensors. The dependence of the materials' microstructure and properties (sheet resistance and its temperature coefficient, gauge factor) is studied as a function of firing temperature and time, and cooling rate (furnace or quench). The stability of the properties is assessed by annealing at intermediate temperatures (100 and 250 °C). Microscopic and struc...

  17. Tuneable PTC effect in polymer-wax-carbon composite resistors

    OpenAIRE

    Maeder, Thomas; Jacq, Caroline; Ammon, Ludivine; Ryser, Peter

    2013-01-01

    The resistivity dependence on temperature of composite resistors made of carbon fillers dispersed in an organic matrix are known to be strongly affected by the matrix thermal expansion. High positive temperature coefficient (PTC) effects, i.e. essentially switching from resistive to quasi-insulating behaviour, can be caused by phase changes in the matrix and the assorted volume expansion, a behaviour that has been previously shown with both simple organic waxes (low temperatures) and semicrys...

  18. Embedded Resistors and Capacitors in Organic and Inorganic Substrates

    Science.gov (United States)

    Gerke, Robert David; Ator, Danielle

    2006-01-01

    Embedded resistors and capacitors were purchased from two technology; organic PWB and inorganic low temperature co-fire ceramic (LTCC). Small groups of each substrate were exposed to four environmental tests and several characterization tests to evaluate their performance and reliability. Even though all passive components maintained electrical performance throughout environmental testing, differences between the two technologies were observed. Environmental testing was taken beyond manufacturers' reported testing, but general not taken to failure. When possible, data was quantitatively compared to manufacturer's data.

  19. Recent development of detectors with integrated capacitors and polysilicon resistors

    Energy Technology Data Exchange (ETDEWEB)

    Evensen, L.; Hansen, T.E.; Horisberger, R.; Hubbeling, L.; Kaukonen, H.P.; Maehlum, G.; Peisert, A.; Tuuva, T.; Weilhammer, P.; Zalewska, A.

    1988-02-01

    The authors developed a silicon microstrip detector with capacitive coupling of the diode strips to the metallization and with polysilicon bias resistors to each diode. It allows the decoupling of the leakage current from the input to the charge sensitive amplifier especially in the case of LSI electronics. Results are given on the coupling capacity and the breakdown voltage as well as on the polysilicon line resistance.

  20. System and method of modulating electrical signals using photoconductive wide bandgap semiconductors as variable resistors

    Science.gov (United States)

    Harris, John Richardson; Caporaso, George J; Sampayan, Stephen E

    2013-10-22

    A system and method for producing modulated electrical signals. The system uses a variable resistor having a photoconductive wide bandgap semiconductor material construction whose conduction response to changes in amplitude of incident radiation is substantially linear throughout a non-saturation region to enable operation in non-avalanche mode. The system also includes a modulated radiation source, such as a modulated laser, for producing amplitude-modulated radiation with which to direct upon the variable resistor and modulate its conduction response. A voltage source and an output port, are both operably connected to the variable resistor so that an electrical signal may be produced at the output port by way of the variable resistor, either generated by activation of the variable resistor or propagating through the variable resistor. In this manner, the electrical signal is modulated by the variable resistor so as to have a waveform substantially similar to the amplitude-modulated radiation.

  1. Investigation of OSL signal of resistors from mobile phones for accidental dosimetry

    CERN Document Server

    Mrozik, Anna; Bilski, Pawel; Gieszczyk, Wojciech

    2014-01-01

    Resistors from mobile phones, usually located near the human body, are considered as individual dosimeters of ionizing radiation in emergency situations. The resistors contain Al2O3, which is optically stimulated luminescence (OSL) material sensitive to ionizing radiation. This work is focused on determination of dose homogeneity within a mobile phones which was carried out by OSL measurements of resistors placed in different parts inside the mobile phone. Separate, commercially available resistors, similar in the shape and size to the resistors from circuit board of the studied mobile phone, were situated in different locations inside it. The irradiations were performed in uniform 60Co and 137Cs radiation fields, with the mobile phones connected and not connected to the cellular network. The dose decrease of 9% was measured for original resistors situated between layer of copper-clad laminate and battery, in comparison to the dose at the front of the phone. The resistors showed the lower signal when the mobi...

  2. Monitoring the Digital Divide

    CERN Document Server

    Canessa, E; Matthews, W; Cottrell, R L A

    2003-01-01

    It is increasingly important to support the large numbers of scientists working in remote areas and having low -bandwidth access to the Internet. This will continue to be the case for years to come since there is evidence from PingER performance measurements that the, so-called, digital divide is not decreasing. In this work, we review the collaborative work of The Abdus Salam International Center for Theoretical Physics (ICTP) in Trieste -a leading organization promoting science dissemination in the developing world- and SLAC in Stanford, to monitor by PingER, Universities and Research Institutions all over the developing world following the recent Recommendations of Trieste to help bridge the digital divide. As a result, PingER's deployment now covers the real-time monitoring of worldwide Internet performance and, in particular, West and Central Africa for the first time. We report on theresults from the ICTP sites and quantitatively identify regions with poor performance, identify trends, discuss experienc...

  3. Monitoring the Digital Divide

    OpenAIRE

    E. Canessa; Cerdeira, H. A.; Matthews, W.; Cottrell, R. L.

    2003-01-01

    It is increasingly important to support the large numbers of scientists working in remote areas and having low -bandwidth access to the Internet. This will continue to be the case for years to come since there is evidence from PingER performance measurements that the, so-called, digital divide is not decreasing. In this work, we review the collaborative work of The Abdus Salam International Center for Theoretical Physics (ICTP) in Trieste -a leading organization promoting science disseminatio...

  4. Bridging the urological divide

    OpenAIRE

    Roberts Robin

    2011-01-01

    Abstract The advanced disease clinical presentations, higher morbidity and mortality rates and lack of available treatment options in prostate cancer care, attest to disparities in the delivery and outcomes of urological services in Black men of African lineage in both the Developed and Developing countries. This gap in health care and services in the global management of prostate cancer denotes the urological divide. Through the experience of a Developing country urologist with a comparative...

  5. Melting the Divide

    Science.gov (United States)

    Gibson, S. M.

    2014-12-01

    Presenting Quaternary Environmental Change to students who fall into Widening Participation criteria at the University of Cambridge, gives a unique opportunity to present academic debate in an approachable and entertaining way. Literally by discussing the melting of our ice caps, melts the divide Cambridge has between its reputation and the reality for the brightest, underprivileged, students. There is a balance between presenting cutting edge research with the need to come across as accessible (and importantly valuable to "learning"). Climate change over the Quaternary lends itself well to this aim. By lecturing groups of potential students through the entire Quaternary in an hour, stopping to discuss how our ancestors interacted with past Interglacials and what are the mechanisms driving change (in generalized terms), you are able to introduce cutting edge research (such as the latest NEEM ice core) to the students. This shows the evolution and importance of higher education and academic research. The lecture leads well onto group discussions (termed "supervisions" in Cambridge), to explore their opinions on the concern for present Anthropogenic Climate Change in relation to Past Climate Change after being presented with images that our ancestors "made it". Here discussion thrives off students saying obvious things (or sarcastic comments!) which quickly can lead into a deep technical discussion on their terms. Such discussions give the students a zest for higher education, simply throwing Ruddiman's (2003) "The Anthroprocene Started Several Thousand Years Ago" at them, questions in a second their concept of Anthropogenic Climate Change. Supervisions lend themselves well to bright, articulate, students and by offering these experiences to students of Widening Participation criteria we quickly melt the divide between the reputation of Cambridge ( and higher education as a whole) and the day to day practice. Higher education is not for the privileged, but a free and open environment for the exchange of ideas. Quaternary Environmental Change lends itself, as an engaging and "fun" subject, well to potential students bridging the divide between ability and circumstance.

  6. Bridging the Digital Divide

    DEFF Research Database (Denmark)

    Frølunde, Lisbeth

    The article concerns the digital divide, meaning the social inequity in the access and the opportunities for gaining competencies with ICT (information and communication technologies). Problematic issues are highlighted in relation to experiences during visits to several Computer Clubhouses, a...... Education have published the white book 'Life of Science - White Book on Educational Initiatives in the Natural Sciences and Technology', inconnection with a conference for EIST (Initiatives in Science and Technology). The purpose of the EIST project is to make a qualitative overview of a number of...

  7. Investigation of OSL signal of resistors from mobile phones for accidental dosimetry

    International Nuclear Information System (INIS)

    Resistors from mobile phones, usually located near the human body, are considered as individual dosimeters of ionizing radiation in emergency situations. The resistors contain Al2O3, which is optically stimulated luminescence (OSL) material sensitive to ionizing radiation. This work is focused on determination of dose homogeneity within mobile phones which was carried out by OSL measurements of resistors placed in different parts inside the mobile phone. Separate, commercially available resistors, similar in the shape and size to the resistors from circuit board of the studied mobile phone, were situated in different locations inside it. The irradiations were performed in uniform 60Co and 137Cs radiation fields, with the mobile phones connected and not connected to the cellular network. The dose decrease of 9% was measured for original resistors situated between circuit board and battery, in comparison to the dose at the front of the phone. The resistors showed the lower signal when the mobile phone was connected to the cellular network, due to higher temperature inside the housing. The profile of fading was investigated within 3 month period for resistors irradiated with 1 Gy of gamma rays to estimate of the fading coefficient. - Highlights: • Impact of a mobile phone mode (switched on/off) on absorbed dose by resistors was showed. • The influence of the temperature during irradiation on absorbed dose was measured. • Dose distribution inside of a mobile phone was performed. • Fading factor of resistors was calculated

  8. Design, construction, and testing of solution resistive divider applied in hundreds of kilovolts nanosecond pulse measurement

    Science.gov (United States)

    Ge, Ya-Feng; Li, Lee; Liu, Yun-Long; Li, Mingjia; Kang, Qiang

    2014-10-01

    The solution resistive divider is often used considering its excellent high-frequency and withstanding voltage characteristics. This paper develops a nanosecond pulse measurement system based on the CuSO4 solution resistive divider, which can be used to measure high voltage impulses with rise time of 50 ns and amplitude of 300 kV. The low-voltage arm of the newly designed solution resistive divider is composed of noninductive metal film resistors. The newly designed resistive divider combines the advantages of the conventional solution resistive divider and metal film resistive divider. The stray parameters of the resistive divider are theoretically calculated and the circuit simulation is studied. Besides, the square wave response characteristics of the resistive divider are studied in the experiments. Considering the effect of frequency on the surge impedance of the cable, a matching cable of the same type with the transmission cable instead of a common matching resistor is used to improve the matching effects. In order to reduce the effects of electromagnetic interference on the measurement results, some shielding measures are taken. The experimental results show that the measurement system has good response characteristics in the practical application.

  9. Next generation KATRIN high precision voltage divider for voltages up to 65kV

    International Nuclear Information System (INIS)

    The KATRIN (KArlsruhe TRItium Neutrino) experiment aims to determine the mass of the electron antineutrino with a sensitivity of 200 meV by precisely measuring the electron spectrum of the tritium beta decay. This will be done by the use of a retarding spectrometer of the MAC-E-Filter type. To achieve the desired sensitivity the stability of the retarding potential of -18.6 kV has to be monitored with a precision of 3 ppm over at least two months. Since this is not feasible with commercial devices, two ppm-class high voltage dividers were developed, following the concept of the standard divider for DC voltages of up to 100 kV of the Physikalisch-Technische Bundesanstalt (PTB). In order to reach such high accuracies different effects have to be considered. The two most important ones are the temperature dependence of resistance and leakage currents, caused by insulators or corona discharges. For the second divider improvements were made concerning the high-precision resistors and the thermal design of the divider. The improved resistors are the result of a cooperation with the manufacturer. The design improvements, the investigation and the selection of the resistors, the built-in ripple probe and the calibrations at PTB will be reported here. The latter demonstrated a stability of about 0.1 ppm/month over a period of two years

  10. Monitoring the digital divide

    International Nuclear Information System (INIS)

    It is increasingly important to support the large numbers of scientists working in remote areas and having low-bandwidth access to the Internet. This will continue to be the case for years to come since there is evidence from PingER performance measurements that the, so-called, digital divide is not decreasing. In this work, we review the collaborative work of The Abdus Salam International Center for Theoretical Physics (ICTP) in Trieste - a leading organization promoting science dissemination in the developing world- and SLAC in Stanford, to monitor by PingER, Universities and Research Institutions all over the developing world following the recent 'Recommendations of Trieste' to help bridge the digital divide. As a result, PingER's deployment now covers the real-time monitoring of worldwide Internet performance and, in particular, West and Central Africa for the first time. We report on the results from the ICTP sites and quantitatively identify regions with poor performance, identify trends, discuss experiences and future work. (author)

  11. Monitoring the Digital Divide

    International Nuclear Information System (INIS)

    It is increasingly important to support the large numbers of scientists working in remote areas and having low bandwidth access to the Internet. This will continue to be the case for years to come since there is evidence from PingER performance measurements that the, so-called, digital divide is not decreasing. In this work, we review the collaborative work of The Abdus Salam International Center for Theoretical Physics (ICTP) in Trieste, a leading organization promoting science dissemination in the developing world- and SLAC in Stanford, to monitor by PingER, Universities and Research Institutions all over the developing world following the recent ''Recommendations of Trieste'' to help bridge the digital divide. As a result, PingER's deployment now covers the real-time monitoring of worldwide Internet performance and, in particular, West and Central Africa for the first time. We report on the results from the ICTP sites and quantitatively identify regions with poor performance, identify trends, discuss experiences and future work

  12. Bridging the urological divide.

    Science.gov (United States)

    Roberts, Robin

    2011-09-23

    The advanced disease clinical presentations, higher morbidity and mortality rates and lack of available treatment options in prostate cancer care, attest to disparities in the delivery and outcomes of urological services in Black men of African lineage in both the Developed and Developing countries. This gap in health care and services in the global management of prostate cancer denotes the urological divide.Through the experience of a Developing country urologist with a comparative literature review, this presentation defines the determinants of the disparity through deficiencies in human, material and financial resources, as is most prevalent in Developing countries.Solutions to ending health care disparities must take into account the existing development phase of Third World countries and thus determine whether the Developed countries should export a total service delivery system or seek primarily to advance the competence and skills of the existing Developing country resources.Collaboration in prostate cancer research has the greatest promise and sustainability of bridging this urological divide and is of mutual benefit to both entities. PMID:21992183

  13. Electrical Switching of Perovskite Thin-Film Resistors

    Science.gov (United States)

    Liu, Shangqing; Wu, Juan; Ignatiev, Alex

    2010-01-01

    Electronic devices that exploit electrical switching of physical properties of thin films of perovskite materials (especially colossal magnetoresistive materials) have been invented. Unlike some related prior devices, these devices function at room temperature and do not depend on externally applied magnetic fields. Devices of this type can be designed to function as sensors (exhibiting varying electrical resistance in response to varying temperature, magnetic field, electric field, and/or mechanical pressure) and as elements of electronic memories. The underlying principle is that the application of one or more short electrical pulse(s) can induce a reversible, irreversible, or partly reversible change in the electrical, thermal, mechanical, and magnetic properties of a thin perovskite film. The energy in the pulse must be large enough to induce the desired change but not so large as to destroy the film. Depending on the requirements of a specific application, the pulse(s) can have any of a large variety of waveforms (e.g., square, triangular, or sine) and be of positive, negative, or alternating polarity. In some applications, it could be necessary to use multiple pulses to induce successive incremental physical changes. In one class of applications, electrical pulses of suitable shapes, sizes, and polarities are applied to vary the detection sensitivities of sensors. Another class of applications arises in electronic circuits in which certain resistance values are required to be variable: Incorporating the affected resistors into devices of the present type makes it possible to control their resistances electrically over wide ranges, and the lifetimes of electrically variable resistors exceed those of conventional mechanically variable resistors. Another and potentially the most important class of applications is that of resistance-based nonvolatile-memory devices, such as a resistance random access memory (RRAM) described in the immediately following article, Electrically Variable Resistive Memory Devices (MFS-32511-1).

  14. Divide and Pacify

    DEFF Research Database (Denmark)

    Vanhuysse, Pieter

    of them onto unemployment benefits and many others onto early retirement and disability pensions. From a narrow economic viewpoint, these policies often appeared to be immensely costly or irresponsibly populist. Yet a more inclusive social-scientific perspective can shed new light on these seemingly...... explanatory framework in which the strategic use of social policy and the role of local social networks are key variables. … With his empirical analysis Vanhuysse not only confirms his thesis, but also presents an interesting account of how these early social policy choices led to different paths of social...... which welfare provisions can play a functional social pacifying role, but also, and this is the extremely innovative element proposed by Vanhuysse, dividing functions which do not necessarily lead to system-instability. …a must read." – Acta Politica "A double transition of momentous proportions has...

  15. Ultra-high-ohmic microstripline resistors for Coulomb blockade devices

    OpenAIRE

    Lotkhov, Sergey V.

    2013-01-01

    In this paper, we report on the fabrication and the low-temperature characterization of extremely high-ohmic microstrip resistors made of a thin film of weakly oxidized titanium. Nearly linear voltage-current characteristics were measured at temperatures down to $T \\sim \\unit[20]{mK}$ for films with sheet resistivity up to as high as $\\sim \\unit[7]{k\\Omega}$, i.e. about an order of magnitude higher than our previous findings for weakly oxidized Cr. Our analysis indicates that such an improvem...

  16. Standard-resistor compounds with adjustable operating temperature

    Science.gov (United States)

    Oe, T.; Urano, C.; Kaneko, N.; Hadano, M.; Takenaka, K.

    2013-10-01

    The broad peak of the temperature-resistivity curve ?(T) in antiperovskite Mn3AgN can potentially be used to develop materials with temperature coefficients of resistance as low as that of the widely used standard-resistor material Manganin. By partially replacing Ag by In or Mn by Fe, we suppressed the peak height of ?(T) in Mn3AgN to levels that in some cases were lower than that of Manganin, and by co-doping with Cu and In or Fe, the peak temperature could be controlled over a temperature width of at least 50 K around room temperature while retaining the broadness of ?(T) curve.

  17. Carbon dioxide response of semiconducting oxide gas sensitive resistors

    International Nuclear Information System (INIS)

    The work described in this thesis explores the use of barium stannate, BaSnO3 as a gas-sensitive resistor material, sensitive at elevated temperature to the presence of small concentrations of carbon dioxide in air. The behaviour of the substituted compounds (Ba,A')(Sn,B')O3, where A' = Ca and B' = Sb, have also been explored. Separation of effects on the measured resistance of processes occurring at the inter-grain boundaries from effects due to changes in the bulk resistance of the crystallites was made by impedance spectroscopy. Some exploration of the nature of the surface species present, and comparison with those present on other oxides, was made using Fourier transform infra-red spectroscopy (FTIR). For BaSnO3, effects on the resistivity were distinguished for concentrations of carbon dioxide in air ranging from 100 ppm to 1.0x105 ppm, in dry conditions. At concentrations exceeding 1.0x105 ppm the response law of BaSnO3 tended to saturate. These effects were clearly distinguishable from the effects of changing oxygen partial pressure. In the presence of moisture (50% r.h.) the lower detection limit was reduced to 600 ppm and the saturation effect observed in dry conditions was not evident; the response of BaSnO3 continued to increase as the carbon dioxide concentration increased. The origin of the response was at the grain boundaries of the crystallites. Both Sb- and Ca-substitution greatly decreased the response. For both BaSnO3 and Ba(Sn,Sb)O3, the sign of the response was temperature dependent. The transition temperature between the different regimes changed upon Sb-substitution. The interference due to water vapour was also changed by Sb-substitution. Surface carbonates were detected by FTIR following gas exposure at ambient temperature. A mechanism postulating the formation of a surface carbonate satisfactorily rationalised the results. Attempts to implement diffuse reflectance FTIR at elevated temperature were unsuccessful. Literature reports of the successful realisation of carbon dioxide sensor employing a BaSnO3 - CuO composite addressed by impedance spectroscopy, were followed up. The possibility of enhancement of the response near the percolation limit of the conductance of the composite was investigated. Composites of BaSnO3 - CuO, SnO2 - Al2O3 and BaSnO3 Al2O3 were studied. For the BaSnO3 - CuO composites the main effect of CuO addition was simply to decrease to resistivity into an easily measurable range. No enhancement of response near the percolation limit in semiconductor - insulator composites was found. (author)

  18. Control of Electrical Properties of RuO2 Thick Film Resistors

    OpenAIRE

    Yoshiaki Taketa; Toshio Inokuma

    1987-01-01

    Oxides of various elements have been added to RuO2 thick film resistors and the electrical properties of the resultant resistors have been examined.It is found that almost all the oxides of transition metals, rare earths, and antimony used as additivies can closely control the resistivity and TCR of the resistors to obtain a required value. In addition, it is found that the principle of superposition applies to the additives.

  19. Investigation of OSL signal of resistors from mobile phones for accidental dosimetry

    OpenAIRE

    Mrozik, Anna; Marczewska, Barbara; Bilski, Pawel; Gieszczyk, Wojciech

    2014-01-01

    Resistors from mobile phones, usually located near the human body, are considered as individual dosimeters of ionizing radiation in emergency situations. The resistors contain Al2O3, which is optically stimulated luminescence (OSL) material sensitive to ionizing radiation. This work is focused on determination of dose homogeneity within a mobile phones which was carried out by OSL measurements of resistors placed in different parts inside the mobile phone. Separate, commercially available res...

  20. Layered ultra-thin coherent structures used as electrical resistors having low temperature coefficient of resistivity

    Science.gov (United States)

    Werner, Thomas R. (Argonne, IL); Falco, Charles M. (Tucson, AZ); Schuller, Ivan K. (Woodridge, IL)

    1984-01-01

    A thin film resistor having a controlled temperature coefficient of resistance (TCR) ranging from negative to positive degrees kelvin and having relatively high resistivity. The resistor is a multilayer superlattice crystal containing a plurality of alternating, ultra-thin layers of two different metals. TCR is varied by controlling the thickness of the individual layers. The resistor can be readily prepared by methods compatible with thin film circuitry manufacturing techniques.

  1. A broadband regenerative frequency divider in InGaP/GaAs HBT technology

    International Nuclear Information System (INIS)

    A dynamic divide-by-two regenerative frequency divider (RFD) is presented in a 60-GHz-fT InGaP/GaAs heterojunction bipolar transistors (HBTs) technology. To achieve high operation bandwidth, active loads instead of resistor loads are incorporated into the RFD. On-wafer measurement shows that the divider is operating from 10 GHz up to at least 40 GHz, limited by the available input frequency. The maximum operation frequency of the divider is found to be much higher than fT/2 of the transistor, and also the divider has excellent input sensitivity. The divider consumes 300.85 mW from 5 V supply and occupies an area of 0.47 × 0.22 mm2. (semiconductor integrated circuits)

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

    International Nuclear Information System (INIS)

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

  3. Challenging the Digital Divide

    Science.gov (United States)

    Kembhavi, Ajit

    2006-08-01

    Vast quantities of astronomical data in the form of images, spectra and catalogues are now freely available over the internet, and tools for producing science from these resources are also becoming available, particularly through the emerging Virtual Observatories. In addition to this, most astronomical literature from research journals is available at no cost through the ADS and preprint service. This situation, in principle, provides equal opportunity to astronomers located anywhere in the world to participate in the process of discovery. The only requirement is that the astronomers have access to the internet, and a fertile imagination. But in the real world, astronomers in many countries have very limited bandwidth and computing power, and are therefore excluded from meaningful participation in astronomical research, even though they may have the ideas and experience to contribute substantially to the effort. The lack of connectivity and computing hardware also makes it difficult for astronomers in many countries from exposing adequately any data resources that they may have produced locally. This situation prevents many aspiring and experienced astronomers from reaching their creative potential, and from attracting young persons to the charms of modern astronomy; it also leads to opportunity loss to astronomy, as it loses out on the the human resources and fresh ideas and talents which astronomers from developing countries could bring to the subject. I will discuss in my talk the nature and extent of this digital divide, the ways in which it could be mitigated, and the benefits which would arise from the unification. I will base some of my discussion on my experiences in setting up a major programme to take the advantages of the internet revolution to hundreds of universities in India.

  4. Fabrication and electrical characterization of silicon nanowires based resistors

    Energy Technology Data Exchange (ETDEWEB)

    Ni, L; Demami, F; Rogel, R; Salauen, A C; Pichon, L, E-mail: rrogel@univ-rennes1.fr [Institut d' Electronique et des Telecommunications de Rennes, Groupe Microelectronique, UMR CNRS 6164, Universite de Rennes 1, campus de Beaulieu, 263 avenue du general Leclerc, 35042 Rennes cedex (France)

    2009-11-15

    Silicon nanowires (SiNWs) are synthesized via the Vapor-Liquid-Solid (VLS) mechanism using gold (Au) as metal catalyst and silane (SiH{sub 4}) as precursor gas. Au nanoparticles are employed as liquid droplets catalysis during the SiNWs growth performed in a hot wall LPCVD reactor at 480deg. C and 40 Pa. SiNWs local synthesis at micron scale is demonstrated using classical optical photolithography process. SiNWs grow with high density anchored at the dedicated catalyst islands. This resulting network is used to interconnect two heavily doped polysilicon interdigitated electrodes leading to the formation of electrical resistors in a coplanar structure. Current-voltage (I-V) characteristics highlight a symmetric shape. The temperature dependence of the electrical resistance is activated, with activation energy of 0.47 eV at temperatures greater than 300K.

  5. A novel charge sensitive preamplifier without the feedback resistor

    International Nuclear Information System (INIS)

    A novel charge sensitive preamplifier which has no resistor in parallel with the feedback capacitor is presented. No external device or circuit is required to discharge the feedback capacitor. The detector leakage and signal current flows away through the gate of the first JFET which works with its gate to source junction slightly forward biased. The DC stabilization of the preamplifier is accomplished by an additional feedback loop, which permits to equalize the current flowing through the forward baised gate to source junction and the current coming from the detector. An equivalent noise charge of less than 20 electrons r.m.s. has been measured at room temperature by using an input JFET with a transconductance to gate capacitance ratio of 4 mS/5.4 pF

  6. Divided Differences of Implicit Functions

    OpenAIRE

    Muntingh, Georg; Floater, Michael S.

    2012-01-01

    Under general conditions, the equation $g(x,y) = 0$ implicitly defines $y$ locally as a function of $x$. In this article, we express divided differences of $y$ in terms of bivariate divided differences of $g$, generalizing a recent result on divided differences of inverse functions.

  7. Indium Tin Oxide Resistor-Based Nitric Oxide Microsensors

    Science.gov (United States)

    Xu, Jennifer C.; Hunter, Gary W.; Gonzalez, Jose M., III; Liu, Chung-Chiun

    2012-01-01

    A sensitive resistor-based NO microsensor, with a wide detection range and a low detection limit, has been developed. Semiconductor microfabrication techniques were used to create a sensor that has a simple, robust structure with a sensing area of 1.10 0.99 mm. A Pt interdigitated structure was used for the electrodes to maximize the sensor signal output. N-type semiconductor indium tin oxide (ITO) thin film was sputter-deposited as a sensing material on the electrode surface, and between the electrode fingers. Alumina substrate (250 m in thickness) was sequentially used for sensor fabrication. The resulting sensor was tested by applying a voltage across the two electrodes and measuring the resulting current. The sensor was tested at different concentrations of NO-containing gas at a range of temperatures. Preliminary results showed that the sensor had a relatively high sensitivity to NO at 450 C and 1 V. NO concentrations from ppm to ppb ranges were detected with the low limit of near 159 ppb. Lower NO concentrations are being tested. Two sensing mechanisms were involved in the NO gas detection at ppm level: adsorption and oxidation reactions, whereas at ppb level of NO, only one sensing mechanism of adsorption was involved. The NO microsensor has the advantages of high sensitivity, small size, simple batch fabrication, high sensor yield, low cost, and low power consumption due to its microsize. The resistor-based thin-film sensor is meant for detection of low concentrations of NO gas, mainly in the ppb or lower range, and is being developed concurrently with other sensor technology for multispecies detection. This development demonstrates that ITO is a sensitive sensing material for NO detection. It also provides crucial information for future selection of nanostructured and nanosized NO sensing materials, which are expected to be more sensitive and to consume less power.

  8. Voltage divider effect for the improvement of variability and endurance of TaOx memristor.

    Science.gov (United States)

    Kim, Kyung Min; Yang, J Joshua; Strachan, John Paul; Grafals, Emmanuelle Merced; Ge, Ning; Melendez, Noraica Davila; Li, Zhiyong; Williams, R Stanley

    2016-01-01

    The impact of a series resistor (RS) on the variability and endurance performance of memristor was studied in the TaOx memristive system. A dynamic voltage divider between the RS and memristor during both the set and the reset switching cycles can suppress the inherent irregularity of the voltage dropped on the memristor, resulting in a greatly reduced switching variability. By selecting the proper resistance value of RS for the set and reset cycles respectively, we observed a dramatically improved endurance of the TaOx memristor. Such a voltage divider effect can thus be critical for the memristor applications that require low variability, high endurance and fast speed. PMID:26830763

  9. Effective thermal conductivity of real two-phase systems using resistor model with ellipsoidal inclusions

    Indian Academy of Sciences (India)

    Jagjiwanram; Ramvir Singh

    2004-08-01

    A theoretical model has been developed for real two-phase system assuming linear flow of heat flux lines having ellipsoidal particles arranged in a three-dimensional cubic array. The arrangement has been divided into unit cells, each of which contains an ellipsoid. The resistor model has been applied to determine the effective thermal conductivity (ETC) of the unit cell. To take account of random packing of the phases, non-uniform shape of the particles and non-linear flow of heat flux lines in real systems, incorporating an empirical correction factor in place of physical porosity modifies an expression for ETC. An effort is made to correlate it in terms of the ratio of thermal conductivities of the constituents and the physical porosity. Theoretical expression so obtained has been tested on a large number of samples cited in the literature and found that the values predicted are quite close to the experimental results. Comparison of our model with different models cited in the literature has also been made.

  10. Does the "digital divide" exist ?

    OpenAIRE

    Guichard, Eric

    2003-01-01

    This text begins with a criticism of discourses about the notion of digital divide'. Regardless of the identity of their authors (politicians, G8 experts', activists), these speeches are mostly based on technical determinism and on a confusion between information and its support. This paper studies the quality and the functions of the measures of the supposed digital divide', that serve above all to legitimize a posteriori this notion of divide, whilst expressing prejudices about nations a...

  11. Gentilly 2 divider plate replacement

    International Nuclear Information System (INIS)

    The steam generators at the Gentilly 2 Nuclear Plant in operation since 1983 were built with primary divider plates of a bolted panel configuration. During a routine outage inspection, it was noted that two bolts had dislodged from the divider and were located lying in the primary head. Subsequent inspections revealed erosion damage to a substantial number of divider plate bolts and to a lesser extent, to the divider plate itself. After further inspection and repair the units were returned to operation, however, it was determined that a permanent replacement of the primary divider plates was going to be necessary. After evaluation of various options, it was decided that the panel type dividers would be replaced with a single piece floating design. The divider itself was to be of a one piece all-welded arrangement to be constructed from individual panels to be brought in through the manways. In view of the strength limitations of the bolted attachment of the upper seat bar to the tubesheet, a new welded seat bar was provided. To counteract erosion concerns, the new divider is fitted with erosion resistant inserts or weld buildup and with improved sealing features in order to minimize leakage and erosion. At an advanced stage in the design and manufacture of the components, the issue of divider strength during LOCA conditions came into focus. Analysis was performed to determine the strength and/or failure characteristics of the divider to a variety of small and large LOCA conditions. The paper describes the diagnosis of the original divider plates and the design, manufacture, field mobilization, installation and subsequent operation of the replacement divider plates. (author)

  12. The resistance changes of carbon and metal oxide film resistors by irradiation of 60Co ? rays

    International Nuclear Information System (INIS)

    The resistance changes of glass-sealed deposited-carbon-film and carbon-coated-film resitors and metal oxide glazed resistors made in USA were studied by gamma-ray irradiation. (1) The resistances of deposited-carbon-film resistors of 50, 100 and 200 megohm did not change by irradiation of gamma rays up to 1.9 x 109 R. (2) The carbon-coated-film resistors of 100, 1000, 10000 and 100000 megohm had negative resistance changes by irradiation of gamma rays up to 9.9 x 108 R. (3) The resistances of metal oxide glazed resistors of 100, 1000 and 10000 megohm did not change by irradiation of gamma rays up to 8.8 x 108 R. When radiation monitoring instruments with hi-meg resistors are used in a gamma field with high intensity, the resistors must not be exposed to gamma rays with high doses, or the resistors which do not change by gamma-ray irradiation must be selected. (author)

  13. Research of improved sparse grid non-uniformity correction technologies for infrared resistor array

    Science.gov (United States)

    Du, Hui-jie; Zhao, Hong-ming; Gao, Yang; Yu, Hong; Zhang, Yi

    2015-10-01

    Infrared resistor arrays perform a vital role in the hardware in the loop testing of infrared seekers. Infrared resistor arrays composed of large numbers of suspended resistor elements are commonly used to produce dynamic two-dimensional images of infrared radiation. Due to inconsistencies in the fabrication process of the resistor arrays, the temperature each resistor elements reaches for a given input voltage is variable and this leads to more significant radiance differences, these differences result in spatially-distributed radiance non-uniformity. Therefore, in order to obtain an available infrared image, non-uniformity correction (NUC) is necessary. In this paper, the non-uniformity characters of the infrared resistor arrays are analyzed base on measured data and then an improved sparse grid method for engineering are discussed and analyzed. First of all, the NUC camera has a strong influence on the effectiveness of the infrared resistor arrays NUC procedure. According to the actual fact and the laboratory condition, we presented an alternative method for collecting resistor arrays intended to reduce the influence causing by the NUC camera. Secondly, based on the measured non-uniformity data, we obtain the response characteristics of the infrared resistor arrays. In each gray level, we take two points or several points correction algorithm to calculate the gain data and the offset data, and then the linear look-up table is established. Finally, through MATLAB we develop the correction software, and we can obtain the driving output conveniently. The result shows that the image quality has a remarkable improvement after non-uniformity correction, the non-uniformity correction flow and algorithm preferably satisfies the requirement of the high confidence infrared imaging simulation.

  14. Superconducting-coil--resistor circuit with electric field quadratic in the current

    CERN Document Server

    Poklonski, N A; 10.1134/1.1261987

    2010-01-01

    It is shown for the first time that the observed [Phys. Lett. A 162 (1992) 105] potential difference Phi_t between the resistor and the screen surrounding the circuit is caused by polarization of the resistor because of the kinetic energy of the electrons of the superconducting coil. The proportionality of Phi_t to the square of the current and to the length of the superconducting wire is explained. It is pointed out that measuring Phi_t makes it possible to determine the Fermi quasimomentum of the electrons of a metal resistor.

  15. Phase composition and electrophysical properties of ruthenium resistors modified by oxide compounds of niobium (V)

    International Nuclear Information System (INIS)

    The authors study some electrophysical properties, as well as the phase composition, of real ruthenium thick-film resistors based on lead ruthenate(IV) with additions of niobium(V) compounds by the x-ray powder diffraction method. The study revealed that regardless of the composition of the niobium-containing additions in the modified ruthenium resistor, lead ruthenate(IV), ruthenium dioxide, and Pb1.5Nb2O /SUB 6.5/ are present in the form of crystalline phases. The electrophysical properties of resistors modified by oxide compounds of niobium are completely explicable

  16. Fast microwave switching power divider

    Science.gov (United States)

    Johnson, R. W.; Stockton, R. J.

    1981-01-01

    Unit divides power from single input among any 12 of 120 output terminals and redistributes it in 6 microseconds. Microwave current from coaxial line excites disk feeding many radial strip transmission lines. Built for use in electronically-steered S-band antenna, device also divides and switches energy among filters and phase shifters.

  17. The Digital Divide in Education

    Science.gov (United States)

    Tarman, Bulent

    2003-01-01

    There is a digital divide occurring on every possible level: locally, nationally, and globally. Many people argue that the digital divide unfairly equips wealthy citizen and their children with more information and opportunities than those with lower incomes. In addition, there is a big debate around the world whether technology has benefited

  18. Interdependent resistor networks with process-based dependency

    Science.gov (United States)

    Danziger, Michael M.; Bashan, Amir; Havlin, Shlomo

    2015-04-01

    Studies of resilience of interdependent networks have focused on structural dependencies between pairs of nodes across networks but have not included the effects of dynamic processes taking place on the networks. Here we study the effect of dynamic process-based dependencies on a system of interdependent resistor networks. We describe a new class of dependency in which a nodes functionality is determined by whether or not it is actually carrying current and not just by its structural connectivity to a spanning component. This criterion determines its functionality within its own network as well as its ability to provide support-but not electrical current-to nodes in another network. We present the effects of this new type of dependency on the critical properties of ? and {{B}? }, the overall conductivity of the system and the fraction of nodes which carry current, respectively. Because the conductance of current has direct physical effects (e.g. heat, magnetic induction), the development of a theory of process-based dependency can lead to innovative technology. As an example, we describe how the theory presented here could be used to develop a new kind of highly sensitive thermal or gas sensor.

  19. Ion backscattering study of tantalum nitride thin film resistors

    International Nuclear Information System (INIS)

    Ion backscattering was used to characterize thin film tantalum nitride resistors with thicknesses in the range 500--600 A. The amount of surface oxide, the nitrogen content, its depth distribution, the amount of argon-sputtering gas incorporated into the film, and its depth distribution, are measured directly by the technique. The films were prepared by diode sputtering in a pilot line facility. All sputtering parameters were held constant except for the N2 flowrate, which was varied so as to change the nitrogen concentration in the films. The electrical properties of the films were characterized by measurements of the sheet resistance and the differential Seebeck voltage. Aluminum oxide substrates were used for the electrical measurements and beryllium substrates with thin oxide layers were used for the backscattering compositional analysis. As the N concentration decreased below the stoichiometric composition Ta2N to the composition Ta2N0.5, the resistivity was found to decrease linearly by 25 percent and the differential Seebeck voltage to increase linearly by 90 percent. (U.S.)

  20. Investigation about decoupling capacitors of PMT voltage divider effects on neutron-gamma discrimination

    International Nuclear Information System (INIS)

    Scintillators are almost used in any nuclear laboratory. These detectors combine of scintillation materials, PMT and a voltage divider. Voltage dividers are different in resistive ladder design. But the effect of decoupling capacitors and damping resistors haven’t discussed yet. In this paper at first a good equilibrium circuit designed for PMT, and it was used for investigating about capacitors and resistors in much manner. Results show that decoupling capacitors have great effect on PMT output pulses. In this research, it was tried to investigate the effect of Capacitor’s value and places on PMT voltage divider in Neutron-Gamma discrimination capability. Therefore, the voltage divider circuit for R329-02 Hamamatsu PMT was made and Zero Cross method used for neutron-gamma discrimination. The neutron source was a 20Ci Am-Be. Anode and Dynode pulses and discrimination spectrum were saved. The results showed that the pulse height and discrimination quality change with the value and setting of capacitors

  1. Large, light-induced capacitance enhancement in semiconductor junctions simulated by capacitor-resistor nets

    OpenAIRE

    Vainas, B.

    2015-01-01

    The equivalent circuit simulation of random resistors-capacitors (R-C) net, modified to include large capacitors interfacing between the random R-C bulk and the electrode surface, shows an enhancement of 3 orders of magnitude of the apparent real dielectric constant at low frequencies upon an introduction of resistors percolating paths in the bulk. The appearance of the bulk R-percolating paths can represent the photo-generated high conductivity state of semiconductors bulk, an effect support...

  2. Development of beam-based alignment system using a switchable shunt resistor for HLS

    International Nuclear Information System (INIS)

    The development of beam-based alignment system for Hefei Light Source (HLS) is presented. In this system, a switchable shunt resistor was installed on quadrupole to bypass a small percentage of the magnet current, and solid-state relays were used to switch the shunt resistor. The system can be used to measure the offset of the beam position monitor (BPM) with respect to the magnetic center of a quadrupole. Some measurement results for HLS are given

  3. Implementation of an analogue model of a memristor based on a light-dependent resistor

    International Nuclear Information System (INIS)

    In this paper, an analogue model of a memristor using a light-dependent resistor (LDR) is presented. This model can be simplified into two parts: a control circuit and a variable resistor. It can be used to easily verify theoretical presumptions about the switching properties of memristors. This LDR-based memristor model can also be used in both simulations and experiments for future research into memristor applications. The paper includes mathematical models, simulations, and experimental results

  4. Chopper controlled resistors in VSC-HVDC transmission for WPP with full-scale converters

    OpenAIRE

    Chaudhary, Sanjay Kumar; Teodorescu, Remus; Rodriguez, Pedro; Kjær, P.C.; Christensen, P. W.

    2009-01-01

    Large and distant offshore wind power plants can be efficiently connected to the onshore power grid network using VSC-HVDC (Voltage Source Converter based HVDC) transmission. Chopper controlled resistors can be used to limit the DC line over-voltage when there is a fault on the onshore AC grid and power transfer to the grid is obstructed. Considering the development of full scale converter based wind turbine generators (WTG), use of unit rated chopper controlled resistors...

  5. The electromagnetic "memory" of a dc-conducting resistor: a relativity argument and the electrical circuits

    OpenAIRE

    Gluskin, Emanuel

    2010-01-01

    A circuit-field problem is considered. A resistor conducting a constant current is argued to be associated with electromagnetic energy accumulated in the surrounded space, though contrary to the case of an inductor or a capacitor, this energy is always associated with both magnetic and electrical fields. The circuit-theory point of view saying that a resistor has no electromagnetic memory is accepted, but the necessarily involved (in view of the field argument) capacitance and inductiveness a...

  6. Sensitivity enhancement of polysilicon piezo-resistive pressure sensors with phosphorous diffused resistors

    Energy Technology Data Exchange (ETDEWEB)

    Sivakumar, K [Microelectronics and MEMS Research Laboratory, Department of Electrical Engineering, Indian Institute of Technology Madras, Chennai -600 036 (India); Dasgupta, N [Microelectronics and MEMS Research Laboratory, Department of Electrical Engineering, Indian Institute of Technology Madras, Chennai -600 036 (India); Bhat, K N [Microelectronics and MEMS Research Laboratory, Department of Electrical Engineering, Indian Institute of Technology Madras, Chennai -600 036 (India); Natarajan, K [Small signal Devices, Bharat Electronics, Bangalore-560 013 (India)

    2006-04-01

    It is generally accepted that the piezo-resistive coefficient in single crystal silicon is higher when P-type impurities such as boron are used for doping the resistors. In this paper we demonstrate that the sensitivity of polycrystalline silicon piezo-resistive pressure sensors can be enhanced considerably when phosphorus diffusion source is used instead of boron dopant for realizing the piezo-resistors. Pressure sensors have been designed and fabricated with the polycrystalline piezo-resistors connected in the form of a Wheatstone bridge and laid out on thermal oxide grown on membranes obtained with a Silicon On Insulator (SOI) approach. The SOI wafers required for this purpose have been realized in-house by Silicon Fusion Bonding (SFB) and etch back technique in our laboratory. This approach provides excellent isolation between the resistors and enables zero temperature coefficient of the polysilicon resistor. The results obtained in our laboratory have clearly demonstrated that by optimizing the phosphorus diffusion temperature and duration, it is possible to achieve sensitivities in excess of 20mV /Bar for bridge input voltage of 10V, with linearity within 1% over a differential pressure range up to 10Bar (10 {sup 6}Pascal), and burst pressure in excess of 50 Bar as compared to the 10mV /Bar sensitivity obtained with boron doped polysilicon piezo-resistors. This enhancement is attributed to grain boundary passivation by phosphorous atoms.

  7. Design and Implementation of Coupled-Line Wilkinson Power Dividers Using Alumina Substrate

    Directory of Open Access Journals (Sweden)

    Taufiqqurrachman

    2014-03-01

    Full Text Available This paper presents design and implementation of coupled-line Wilkinson power dividers at frequency 2.4GHz using alumina substrate. This design using Wilkinson power dividers method where consist of two  impedance in the form of coupled lines on microstrip and one resistor is connected on the both of output ports. Design parameters used in the design of coupled lines dividers are input and output matching, insertion loss and isolation between the both output ports. The design parameters presented in graph on the simulation result from ADS2011.10 software simulation and the measurement result from vector network analyzer (VNA R3770 from Advantest. The simulation and measurement results show almost the same results where the return loss is less than -15dB, insertion loss is about -3dB and isolation between the output ports is more than -12dB.

  8. New internal multi-range resistors for ac voltage calibration by using TVC

    Science.gov (United States)

    Ali, Rasha S. M.

    2015-10-01

    Accurate calibration of ac voltages up to 1000 V by using thermal converters requires range resistors connected in series with the converter. The combination of a thermal converter and range resistor is known as the thermal voltage converter. In this paper, multi-range internal range resistors are designed and implemented in the National Institute for Standards (NIS), Egypt to cover the ac voltage ranges from 10 V to 750 V. The range resistor values are 2 kΩ, 10 kΩ, 20 kΩ, 40 kΩ, 100 kΩ, and 150 kΩ to cover the voltage ranges 10 V, 50 V, 100 V, 200 V, 500 V, and 750 V, respectively. The six range resistors are mounted in series with a single-junction thermo-element in the same box to provide a new thermal voltage converter. The required range resistor is selected by using a six-pin selector switch. Each resistor is connected to a selector pin. The new thermal voltage converter ranges are automatically calibrated against other standard thermal voltage converters at different frequencies by using a LabVIEW program to determine their ac-dc transfer difference at each range. The expanded uncertainties are estimated according to the GUM for all ranges at different frequencies. The performance of the new thermal voltage converter is also evaluated by comparing its ac-dc differences and its accuracy in measuring the ac voltage at different frequencies with a traditional thermal voltage converter.

  9. Study and field verification of the effects of removing closing resistors from 500 kV circuit breakers

    International Nuclear Information System (INIS)

    Closing resistors in EHV circuit breakers are frequently used to reduce switching transients on lines thus preventing flashovers during line energization. Maintenance and failures of such closing resistors can be costly and reduce transmission system reliability. For these reasons, APS conducted an investigation into the technical feasibility of operating its 500 kV without closing resistors. This paper describes study results of removing closing resistors from 500 kV breakers in a system which employs older technology silicon carbide type surge arresters. The paper also describes results of field tests of the expected flashover rates calculated in the study. These field tests involve repeatedly energizing a 258 mile 500 kV line using a breaker in which the closing resistors are disabled. Transient overvoltages captured during the tests are compared with predicted overvoltages. The study concludes that closing resistors may be removed from the subject system without unacceptable consequences

  10. Getting Past the "Digital Divide"

    Science.gov (United States)

    McCollum, Sean

    2011-01-01

    As most educators know, there is a lot more to addressing the so-called "digital divide" than having enough working machines in classrooms. Effective information technology (IT) in schools requires useful software, reliable and speedy Internet access, effective teacher training, and well-considered goals with transformative outcomes. Educators who

  11. Getting Past the "Digital Divide"

    Science.gov (United States)

    McCollum, Sean

    2011-01-01

    In the last decade, "digital divide" has become a catchphrase for the stubborn disparity in IT resources between communities, especially in regard to education. Low-income, rural and minority populations have received special scrutiny as the technological "have-nots." This article presents success stories of educators who can work around obstacles

  12. Layered ultra-thin coherent structures used as electrical resistors having low-temperature coefficient of resistivity

    Science.gov (United States)

    Werner, T.R.; Falco, C.M.; Schuller, I.K.

    1982-08-31

    A thin film resistor having a controlled temperature coefficient of resistance (TCR) ranging from negative to positive degrees kelvin and having relatively high resistivity. The resistor is a multilayer superlattice crystal containing a plurality of alternating, ultra-thin layers of two different metals. TCR is varied by controlling the thickness of the individual layers. The resistor can be readily prepared by methods compatible with thin film circuitry manufacturing techniques.

  13. Architecture design of resistor/FET-logic demultiplexer for hybrid CMOS/nanodevice circuit interconnect

    International Nuclear Information System (INIS)

    Hybrid nanoelectronics consisting of nanodevice crossbars on top of CMOS backplane circuits is emerging as one viable option to sustain Moore's law after the CMOS scaling limit is reached. One main design challenge in such hybrid nanoelectronics is the interface between the highly dense nanowires in nanodevice crossbars and relatively coarse microwires in the CMOS domain. Such an interface can be realized through a logic circuit called a demultiplexer (demux). In this context, all the prior work on demux design uses a single type of device, such as resistor, diode or field effect transistor (FET), to realize the demultiplexing function. However, different types of devices have their own advantages and disadvantages in terms of functionality, manufacturability, speed and power consumption. This makes none of them provide a satisfactory solution. To tackle this challenge, this work proposes to combine resistor with FET to implement the demux, leading to the hybrid resistor/FET-logic demux. Such hybrid demux architecture can make these two types of devices complement each other well to improve the overall demux design effectiveness. Furthermore, due to the inevitable fabrication process variations at the nanoscale, the effects of resistor conductance and FET threshold voltage variability are analyzed and evaluated based on computer simulations. The simulation results provide the requirement on the fabrication process to ensure a high demux reliability, and promise the hybrid resistor/FET-logic demux an improved addressability and process variance tolerance

  14. Information Societies and Digital Divides

    CERN Document Server

    Sorj, Bernardo

    2008-01-01

    The book argues ICT are part of the set of goods and services that determine quality of life, social inequality and the chances for economic development. Therefore understanding the digital divide demands a broader discussion of the place of ICT within each society and in the international system. The author argues against the perspectives that either isolates ICT from other basic social goods (in particular education and employment) as well as those that argue that new technologies are luxury of a consumer society. Though the author accepts that new technologies are not a panacea for the problems of inequality, access to them become a condition of full integration of social life. Using examples mainly from Latin America, the work presents some general policy proposals on the fight against the digital divide which take in consideration other dimensions of social inequality and access to public goods. Bernardo Sorj was born in Montevideo, Uruguay. He is a naturalized Brazilian, living in Brazil since 1976. He ...

  15. AC-coupled GaAs microstrip detectors with a new type of integrated bias resistors

    CERN Document Server

    Irsigler, R; Göppert, R; Hornung, M; Ludwig, J; Rogalla, M; Runge, K; Schmid, T; Söldner-Rembold, S; Webel, M; Weber, C; Schmid, Th.

    1998-01-01

    Full size single-sided GaAs microstrip detectors with integrated coupling capacitors and bias resistors have been fabricated on 3'' substrate wafers. PECVD deposited SiO_2 and SiO_2/Si_3N_4 layers were used to provide coupling capacitaces of 32.5 pF/cm and 61.6 pF/cm, respectively. The resistors are made of sputtered CERMET using simple lift of technique. The sheet resistivity of 78 kOhm/sq. and the thermal coefficient of resistance of less than 4x10^-3 / degree C satisfy the demands of small area biasing resistors, working on a wide temperature range.

  16. Thermometric characteristics of some 1/8W carbon resistors in the millikelvin range

    International Nuclear Information System (INIS)

    Gotch and Awano (Cryogenic Engineering (Tokyo); 8:18 (1973)) have reported on the useful characteristics of 1/8W 100Ω Matsushita carbon resistors (grade ERC-18GK) as thermometers for the region 0.4K and 4.2K. Measurements on the resistance characteristics of this grade of resistors from 11mK to 1K are reported here. Nominal resistances of 56Ω, 68Ω, 82Ω, 100Ω, and 220Ω have been measured. It is found that the 56Ω, 68Ω and 82 Ω resistors make useful thermometers down to at least 11mK. A comparison of the resistance behaviour of units immersed in dilute He3-He4 with those outside the liquid is also made. (author)

  17. The first measurements on SiPMs with bulk integrated quench resistors

    International Nuclear Information System (INIS)

    High ohmic polysilicon which is used as quench resistor in conventional Silicon photomultipliers (SiPMs) turns out to be an absorber for light and is one of the most cost and yield driving technological issues. The silicon photomultiplier is becoming a very good candidate for the replacement of conventional photomultiplier tubes and thus the development of these devices is very striking. We have proposed a new detector concept which has the quench resistor integrated into the silicon bulk avoiding polysilicon resistors. The quenching mechanism has been demonstrated in a proof of principle production performed in house. The first prototypes have been fabricated (second production run) and allowed testing of the device performance. The results from the first measurements will be presented. Based on these results the inherent advantages and drawbacks compared to standard SiPMs will be discussed.

  18. A Biased Resistor Network Model for Electromigration Phenomena in Metallic Lines

    CERN Document Server

    Pennetta, C; Reggiani, L; Fantini, F; De Munari, I; Scorzoni, A

    2004-01-01

    Electromigration phenomena in metallic lines are studied by using a biased resistor network model. The void formation induced by the electron wind is simulated by a stochastic process of resistor breaking, while the growth of mechanical stress inside the line is described by an antagonist process of recovery of the broken resistors. The model accounts for the existence of temperature gradients due to current crowding and Joule heating. Alloying effects are also included. Monte Carlo simulations enable us to study within a unified theoretical framework a variety of relevant features of electromigration phenomena. The predictions of the model are in excellent agreement with the experiments and in particular with the degradation towards electrical breakdown of stressed Al-Cu thin metallic lines. Detailed investigations refer to the damage pattern, the distribution of the times to failure (TTFs), the generalized Black's law, the time evolution of the resistance, including early-stage change due to alloying effect...

  19. Chemical interaction in resistors based on lead ruthenite with additions of niobium(5) oxide compounds

    International Nuclear Information System (INIS)

    The method of X-ray phase analysis was used to study chemical interaction in isothermal cross-section of Pb2RU2O6-Nb2O5, Rbsub(2)Rusub(2)Osub(6)-NbWOsub(5.5) and Rb2Ru2O6-Pb2Nb2O7 systems at 850 deg C as well as in models of real ruthenium resistors. Chemical interaction is stated to take place in systems with niobium (5) oxide and NbWOsub(5.5). Niobium (5) and tungsten (6) displace ruthenium (4) from its compounds with formation of their lead salts. Similar chemical interactions between current-carrying phase of the resistor and modifiers representing niobium-containing take place in models of components of the studied systems take place in models of resistors

  20. Information Societies and Digital Divides

    OpenAIRE

    Sorj, Bernardo

    2008-01-01

    The book argues ICT are part of the set of goods and services that determine quality of life, social inequality and the chances for economic development. Therefore understanding the digital divide demands a broader discussion of the place of ICT within each society and in the international system. The author argues against the perspectives that either isolates ICT from other basic social goods (in particular education and employment) as well as those that argue that new technologies are luxur...

  1. Method of preparing high-temperature-stable thin-film resistors

    Science.gov (United States)

    Raymond, L.S.

    1980-11-12

    A chemical vapor deposition method for manufacturing tungsten-silicide thin-film resistors of predetermined bulk resistivity and temperature coefficient of resistance (TCR) is disclosed. Gaseous compounds of tungsten and silicon are decomposed on a hot substrate to deposit a thin-film of tungsten-silicide. The TCR of the film is determined by the crystallinity of the grain structure, which is controlled by the temperature of deposition and the tungsten to silicon ratio. The bulk resistivity is determined by the tungsten to silicon ratio. Manipulation of the fabrication parameters allows for sensitive control of the properties of the resistor.

  2. Method of preparing high-temperature-stable thin-film resistors

    Science.gov (United States)

    Raymond, Leonard S.

    1983-01-01

    A chemical vapor deposition method for manufacturing tungsten-silicide thin-film resistors of predetermined bulk resistivity and temperature coefficient of resistance (TCR). Gaseous compounds of tungsten and silicon are decomposed on a hot substrate to deposit a thin-film of tungsten-silicide. The TCR of the film is determined by the crystallinity of the grain structure, which is controlled by the temperature of deposition and the tungsten to silicon ratio. The bulk resistivity is determined by the tungsten to silicon ratio. Manipulation of the fabrication parameters allows for sensitive control of the properties of the resistor.

  3. Use of light-dependent-resistor circuit to remotely reset digital constancy meter.

    Science.gov (United States)

    Perec, A; Kubo, H

    1990-08-01

    A digital constancy meter which has been used in our institution uses a plane-parallel chamber for daily morning output checks of treatment machines. After exposure, the user has to enter the treatment room to obtain the charge reading and reset the meter for the next reading. To avoid this extra step and save time, a remote reset circuit which includes a light-dependent-resistor (LDR), was built into the meter. When the room light is turned off (or dimmed) from the console, the light-dependent-resistor will trigger a circuit which will reset the meter. PMID:2394625

  4. Anisotropic generalization of Stinchcombe's solution for the conductivity of random resistor networks on a Bethe lattice

    International Nuclear Information System (INIS)

    Our study is based on the work of Stinchcombe (1974 J. Phys. C: Solid State Phys. 7 179) and is devoted to the calculations of average conductivity of random resistor networks placed on an anisotropic Bethe lattice. The structure of the Bethe lattice is assumed to represent the normal directions of the regular lattice. We calculate the anisotropic conductivity as an expansion in powers of the inverse coordination number of the Bethe lattice. The expansion terms retained deliver an accurate approximation of the conductivity at resistor concentrations above the percolation threshold. We make a comparison of our analytical results with those of Bernasconi (1974 Phys. Rev. B 9 4575) for the regular lattice.

  5. Break-collapse method for resistor networks-renormalization group applications

    International Nuclear Information System (INIS)

    The break-collapse method recently introduced for the q-state Potts model is adapted for resistor networks. This method greatly simplifies the calculation of the conductance of an arbitrary two-terminal d-dimensional array of conductances, obviating the use of either Kirchhoff's laws or the star-triangle or similiar transformations. Related properties are discussed as well. An illustrative real-space renormalization-group treatment of the random resistor problem on the square lattice is presented; satisfactory results are obtained. (Author)

  6. The characterisation of lead-free thick-film resistors on different low temperature Co-fired ceramics substrates

    International Nuclear Information System (INIS)

    Graphical abstract: Display Omitted Highlights: ► Lead free thick film resistors based on ruthenium oxide were developed. ► The compatibility of resistors with different LTCC substrates was evaluated. ► The interactions between resistors and glassy LTCC substrates were not detected. ► Electrical characteristics were comparable with commercial thick film resistors. -- Abstract: Lead-free thick-film resistors were synthesised and investigated. The thick-film resistor materials with nominal sheet resistivities from 50 ohm/sq. to 50 kohm/sq. were prepared using combinations of two lead-free glasses with reflow temperatures at 940 °C and 1240 °C, respectively, and two RuO2 powders (fine-grained and coarse-grained RuO2). The thick-film resistors were printed and fired on alumina and on low temperature co-fired ceramics substrates and fired at 850 °C and 950 °C. The fired resistors were investigated by X-ray powder diffraction, by scanning electron microscopy and by energy dispersive X-ray analysis. The sheet resistivities, temperature coefficients of resistivity, gauge factors and noise indices were measured.

  7. The characterisation of lead-free thick-film resistors on different low temperature Co-fired ceramics substrates

    Energy Technology Data Exchange (ETDEWEB)

    Hrovat, Marko, E-mail: marko.hrovat@ijs.si [Jožef Stefan Institute, Jamova Cesta 39, SI-1000 Ljubljana (Slovenia); CoE NAMASTE, Jamova Cesta 39, SI-1000 Ljubljana (Slovenia); Kielbasinski, Konrad [Institute of Electronic Materials Technology, Wólczyńska 133, 01-919 Warsaw (Poland); Institute of Microelectronics and Optoelectronics, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw (Poland); Makarovič, Kostja [Jožef Stefan Institute, Jamova Cesta 39, SI-1000 Ljubljana (Slovenia); CoE NAMASTE, Jamova Cesta 39, SI-1000 Ljubljana (Slovenia); Belavič, Darko [HIPOT-RR d.o.o., Šentpeter 18, SI-8222 Otočec (Slovenia); CoE NAMASTE, Jamova Cesta 39, SI-1000 Ljubljana (Slovenia); Jakubowska, Malgorzata [Institute of Electronic Materials Technology, Wólczyńska 133, 01-919 Warsaw (Poland); Faculty of Mechatronics, Warsaw University of Technology, Św. Andrzeja Boboli 8, 02-525 Warsaw (Poland)

    2012-12-15

    Graphical abstract: Display Omitted Highlights: ► Lead free thick film resistors based on ruthenium oxide were developed. ► The compatibility of resistors with different LTCC substrates was evaluated. ► The interactions between resistors and glassy LTCC substrates were not detected. ► Electrical characteristics were comparable with commercial thick film resistors. -- Abstract: Lead-free thick-film resistors were synthesised and investigated. The thick-film resistor materials with nominal sheet resistivities from 50 ohm/sq. to 50 kohm/sq. were prepared using combinations of two lead-free glasses with reflow temperatures at 940 °C and 1240 °C, respectively, and two RuO{sub 2} powders (fine-grained and coarse-grained RuO{sub 2}). The thick-film resistors were printed and fired on alumina and on low temperature co-fired ceramics substrates and fired at 850 °C and 950 °C. The fired resistors were investigated by X-ray powder diffraction, by scanning electron microscopy and by energy dispersive X-ray analysis. The sheet resistivities, temperature coefficients of resistivity, gauge factors and noise indices were measured.

  8. A new optimized design concept of the switching network resistors of the large ITER-FEAT tokamak

    International Nuclear Information System (INIS)

    In the large ITER-FEAT tokamak, resistors are essential electrical components to protect the super-conducting coils but also to produce the needed high voltages in some poloidal field coils during the breakdown and plasma initiation phase to start-up the plasma current. In this specific case, the resistors, called Switching Network Resistors (SNR), must dissipate a large amount of energy but should be also able to provide accurate step resistances within wide ranges of currents and voltages. The step resistances needed in the coil circuits can be precisely determined only during experimentation with the machine. Therefore, a large flexibility has to be foreseen in the design of these resistors. As several SNRs are installed in the large tokamak ITER-FEAT, this paper describes, step by step, a new optimized resistor design concept, with regard to flexibility in operation and cost optimization

  9. Use of cermet thin film resistors with nitride passivated metal insulator field effect transistor

    Science.gov (United States)

    Brown, G. A.; Harrap, V.

    1971-01-01

    Film deposition of cermet resistors on same chip with metal nitride oxide silicon field effect transistors permits protection of contamination sensitive active devices from contaminants produced in cermet deposition and definition processes. Additional advantages include lower cost, greater reliability, and space savings.

  10. Hand-Drawn Resistors and a Simple Tester Using a Light-Emitting Diode

    Science.gov (United States)

    Kamata, Masahiro; Abe, Mayumi

    2012-01-01

    A thick line drawn on a sheet of paper with a 6B pencil is electrically conductive and its resistance can be roughly estimated using a simple tester made of a light-emitting diode (LED) and a lithium coin-type cell. Using this hand-drawn resistor and the LED tester, we developed teaching materials that help students to understand how electrical…

  11. Cosmic Ray Measurements by Scintillators with Metal Resistor Semiconductor Avalanche Photo Diodes

    Science.gov (United States)

    Blanco, Francesco; La Rocca, Paola; Riggi, Francesco; Akindinov, Alexandre; Mal'kevich, Dmitry

    2008-01-01

    An educational set-up for cosmic ray physics experiments is described. The detector is based on scintillator tiles with a readout through metal resistor semiconductor (MRS) avalanche photo diode (APD) arrays. Typical measurements of the cosmic angular distribution at sea level and a study of the East-West asymmetry obtained by such a device are

  12. Electrophysical properties of thin film resistors on the base of nitrided rhenium films

    International Nuclear Information System (INIS)

    Analyzed is the influence of the technological factors, involved in the cathode deposition of rhenium films in the atmosphere, on their electrical and physical properties. Shown is the possibility to produce low-resistance resistors, that have a close-to-zero temperature resistance coefficient at a not less than 0.5% time stability over 1.000 hrs under normal conditions

  13. Anomalous behavior in the resistivity of N-I-N polysilicon resistors after hydrogenation

    International Nuclear Information System (INIS)

    This paper reports on undoped 20 μm thick polycrystalline silicon (polysilicon) films that were epitaxially grown on 0.5 μm thick polysilicon seed layers prepared by cycles of CVD depositions and oxidations. The resistivity of the epitaxial films was found to vary by a factor of 4, depending on the number of deposition/oxidation cycles used to prepare the initial seed layer. Exposing the films to a hydrogen plasma for as little as 5 seconds decreased the resistivity of n-i-n resistors by four orders of magnitude and changed their activation energy from 0.4 eV to 0.001 eV. Whereas, the resitivity of p-i-p resistors only decreased by a factor of two after a 2 hour hydrogenation with no change in the activation energy. The initial high resitivity value of the n-i-n resistors was restored by either removing 0.5 μm of polysilicon from the surface of the resistors or by a 15 minute anneal in argon at 550 degrees C

  14. Sizing of the Series Dynamic Breaking Resistor in a Doubly Fed Induction Generator Wind Turbine

    DEFF Research Database (Denmark)

    Soliman, Hammam; Wang, Huai; Zhou, Dao; Blaabjerg, Frede; Marie, Mostafa I.

    This paper investigates the effect of Series Dynamic Breaking Resistor (SDBR) sizing on a Doubly Fed Induction Generator (DFIG) based wind power conversion system. The boundary of the SDBR value is firstly derived by taking into account the controllability of the rotor side converter and the...

  15. Processing, microstructure, and electric properties of buried resistors in low-temperature co-fired ceramics

    International Nuclear Information System (INIS)

    The electrical properties of ruthenium oxide based devitrifiable resistors embedded within low-temperature co-fired ceramics were investigated from -100oC to 100oC. Special attention was given to the processing conditions and their effects on resistance and temperature coefficient of resistance (TCR). Results indicate that within this temperature range the conductance for these buried resistors is limited by tunneling of charge carriers through the thin glass layer between ruthenium oxide particles. A modified version of the tunneling barrier model is proposed to account for the microstructure ripening observed during thermal processing. The model parameters determined from curve fitting show that charging energy (i.e., the energy required for a charge carrier to tunnel through the glass barrier) is strongly dependent on particle size and particle--particle separation between ruthenium oxide grains. Initial coarsening of ruthenium oxide grains was found to reduce the charging energy and lower the resistance. However, when extended ripening occurs, the increase in particle--particle separation increases the charging energy, reduces the tunneling probability and gives rise to a higher resistance. The tradeoff between these two effects results in an optimum microstructure with a minimum resistance and TCR. Furthermore, the TCR of these buried resistors has been shown to be governed by the magnitude of the charging energy. Model parameters determined by our analysis appear to provide quantitative physical interpretations to the microstructural changes in the resistor, which in turn, are controlled by the processing conditions

  16. Conduction mechanism in granular Ru02-based thick-film resistors

    OpenAIRE

    Schoepe, Wilfried

    1990-01-01

    The conductivity of a commercial thick-film resistor is measured between 4 K and 15 mK and in magnetic fields up to 7 Tesla. The data can be described by the variable-range hopping mechanism with a Coulomb gap in the density of states. The negative magnetoresistance may be attributed to quantum-interference effects in the strongly localized regime.

  17. Fabrication of a Tantalum-Nitride Thin-Film Resistor with a Low-Variability Resistance

    Science.gov (United States)

    Akashi, Teruhisa

    A tantalum-nitride thin-film resistor with a low-variability resistance was formed by optimizing the conditions for depositing a tantalum-nitride thin film. The thin film was deposited by RF-magnetron-reactive sputtering, and nitrogen-pressure ratio, substrate temperature, and deposition rate in the conditions were optimized by measuring electrical properties of the deposited film. Based on the measured resistivity and temperature coefficient of resistance, a nitrogen-pressure ratio of 6.0%, a substrate temperature of 350C, and a deposition rate of 50 nm/min were chosen as the optimum conditions suitable for mass production of the film. The resistor using the thin film deposited under the optimum conditions was fabricated on a silicon optical bench, and showed that its change in resistance is less than 1.4% after conducting reliability tests, which consist of a high-temperature test, a damp-heat test, and a heat-cycle test. Furthermore, the reliability tests estimated that the change in resistance of the resistor would reach only 2.0% even if the 104-hour high-temperature test, which is the severest in three tests, is carried out. It is thus concluded from these results that fabrication under the optimized conditions can produce a thin-film resistor with a low-variability resistance.

  18. Cosmic Ray Measurements by Scintillators with Metal Resistor Semiconductor Avalanche Photo Diodes

    Science.gov (United States)

    Blanco, Francesco; La Rocca, Paola; Riggi, Francesco; Akindinov, Alexandre; Mal'kevich, Dmitry

    2008-01-01

    An educational set-up for cosmic ray physics experiments is described. The detector is based on scintillator tiles with a readout through metal resistor semiconductor (MRS) avalanche photo diode (APD) arrays. Typical measurements of the cosmic angular distribution at sea level and a study of the East-West asymmetry obtained by such a device are…

  19. Electrical properties of thick-layer piezo resistors based on Bi2Ru2O7

    International Nuclear Information System (INIS)

    Piezoelectric effect and electrical properties of thick-layer resistors based on Bi2Ru2O7 (on ceramic substrate) have been studied. The influence of selected technological parameters (sintering temperature, chemical composition, heat treatment) on system properties has been estimated. 4 refs, 7 figs

  20. Phase composition and electrical properties of ruthenium resistors modified by niobium (5) oxide compounds

    International Nuclear Information System (INIS)

    Some electrical properties and phase composition of real ruthenium thick resistor films on the base of lead with niobium (5) additions (Nb2O5, NbWOsub(5.5), Pb2BiNbO6, Pbsub(1.5)Nbsub(2)Osub(6.5) and Pb2Nb2O7) are studied using the X-ray phase analysis method. It is shown that all modified resistors contain at least three crystalline phases: lead ruthenite, ruthenium dioxide and lead niobate; lead tungstate also appears, when adding NbWOsub(5.5). Introduction of niobium (5) oxide compounds to resistive compounds on the base of lead ruthenite results in transformation of their thermal resistance coefficient from positive region to negative one and increases resistor resistance. Similar effect of different niobium-containing modificators upon electrical resistor properties is related to the formation in films of Pbsub(1.5)Nbsub(2)Osub(6.5) and Pb2Nb2O7 semiconductor compounds with high resistance and current-conducting phase representing a mixture of lead ruthenite and ruthenium dioxide

  1. Bridging the global health divides.

    Science.gov (United States)

    2008-10-01

    The information gap between rich and poor countries is widening, and the digital divide is more dramatic than any inequity in health or income.[1] Of 3.47 million articles in 4,091 health-related publications reviewed from 1991 to 2002, 90% were contributed by authors in the 20 most developed nations; writers from the 63 poorest countries accounted for under 2%. Representation from sub-Saharan Africa actually declined over the period, and 96% of the articles were in English. A 2003 survey found only two of 111 editorial board members in a selection of leading medical journals came from low-income countries.[2,3,4]. PMID:21483371

  2. Environment, information divide and design

    International Nuclear Information System (INIS)

    Design of human environment is to be made with understanding human-human and human-environment relations and environmental behaviors of human beings, artifacts and natural things and overcoming their differences and contradictions. Information divide exists naturally due to various differences of human beings. Many problems in the area of nuclear energy seem to be derived from various differences and contradictions in central-local interests, between the particles concerned and unconcerned and also in human being-artifacts relations. In order to harmonize nuclear energy with the society, it is necessary to vanish differences and solve contradictions with redesigning environments of those problems in their context. Case studies are highly recommended with continuous efforts to develop more universal design methodology. Open access to information and data in science and technology is encouraged in the area of nuclear energy. (T. Tanaka)

  3. Crossroads - Bridging the Digital Divide

    Directory of Open Access Journals (Sweden)

    David Cobb

    2005-03-01

    Full Text Available Its so good to be in Cambridge, it feels almost like home. Let me start by stating that in the past year ITMB, a successful map publisher in British Columbia, Canada published more paper map titles than at any time in their history. Similarly, the U.S. Geological Survey (USGS recently announced that they have ceased producing paper from their aerial photography archive and will only produce digital copies. I believe that both of these facts speak to the future of maps and digital data. It means there will be paper maps well into the future and there will be an increasing array of digital data - some of it reformatted, as in the USGS case, and most of it will be born digital. When asked to speak about GIS and its role in libraries I often find myself in a conundrum - am I here to slay the dragon, or to pet the dragon. The role of technology in libraries is not one that has been embraced by everyone, and often the technology itself seems to have been force-fed upon us. The library profession is not one that has historically been a proponent of change and the very nature of GIS is change. In one sense, we have been given the choice of becoming paper museums or, at the very least, making GIS technology available in our collections. Today, I would like to review the many ways that GIS is, or will, affect our collections. I will divide the presentation into a general overview of GIS in libraries, how it affects our acquisitions or collection development policies, its effect on cataloging, on reference services, staffing, and our web services. Then I will shift the focus a little and discuss the current situation at the Harvard Map Collection, the future role of legacy collections, and a look to the future.

  4. Crossroads - Bridging the Digital Divide

    Directory of Open Access Journals (Sweden)

    David Cobb

    2005-03-01

    Full Text Available It’s so good to be in Cambridge, it feels almost like home. Let me start by stating that in the past year ITMB, a successful map publisher in British Columbia, Canada published more paper map titles than at any time in their history. Similarly, the U.S. Geological Survey (USGS recently announced that they have ceased producing paper from their aerial photography archive and will only produce digital copies. I believe that both of these facts speak to the future of maps and digital data. It means there will be paper maps well into the future and there will be an increasing array of digital data - some of it reformatted, as in the USGS case, and most of it will be born digital. When asked to speak about GIS and its role in libraries I often find myself in a conundrum - am I here to slay the dragon, or to pet the dragon. The role of technology in libraries is not one that has been embraced by everyone, and often the technology itself seems to have been force-fed upon us. The library profession is not one that has historically been a proponent of change and the very nature of GIS is change. In one sense, we have been given the choice of becoming paper museums or, at the very least, making GIS technology available in our collections. Today, I would like to review the many ways that GIS is, or will, affect our collections. I will divide the presentation into a general overview of GIS in libraries, how it affects our acquisitions or collection development policies, its effect on cataloging, on reference services, staffing, and our web services. Then I will shift the focus a little and discuss the current situation at the Harvard Map Collection, the future role of legacy collections, and a look to the future.

  5. Effect of Annealing Process on the Properties of Ni(55%)Cr(40%)Si(5%) Thin-Film Resistors

    OpenAIRE

    Huan-Yi Cheng; Ying-Chung Chen; Pei-Jou Li; Cheng-Fu Yang; Hong-Hsin Huang

    2015-01-01

    Resistors in integrated circuits (ICs) are implemented using diffused methods fabricated in the base and emitter regions of bipolar transistor or in source/drain regions of CMOS. Deposition of thin films on the wafer surface is another choice to fabricate the thin-film resistors in ICs applications. In this study, Ni(55%)Cr(40%)Si(5%) (abbreviated as NiCrSi) in wt % was used as the target and the sputtering method was used to deposit the thin-film resistors on Al2O3 substrates. NiCrSi thin-f...

  6. Nanoporous carbon tunable resistor/transistor and methods of production thereof

    Science.gov (United States)

    Biener, Juergen; Baumann, Theodore F; Dasgupta, Subho; Hahn, Horst

    2014-04-22

    In one embodiment, a tunable resistor/transistor includes a porous material that is electrically coupled between a source electrode and a drain electrode, wherein the porous material acts as an active channel, an electrolyte solution saturating the active channel, the electrolyte solution being adapted for altering an electrical resistance of the active channel based on an applied electrochemical potential, wherein the active channel comprises nanoporous carbon arranged in a three-dimensional structure. In another embodiment, a method for forming the tunable resistor/transistor includes forming a source electrode, forming a drain electrode, and forming a monolithic nanoporous carbon material that acts as an active channel and selectively couples the source electrode to the drain electrode electrically. In any embodiment, the electrolyte solution saturating the nanoporous carbon active channel is adapted for altering an electrical resistance of the nanoporous carbon active channel based on an applied electrochemical potential.

  7. Depth of interaction detection with enhanced position-sensitive proportional resistor network

    International Nuclear Information System (INIS)

    A new method of determining the depth of interaction of γ-rays in thick inorganic scintillation crystals was tested experimentally. The method uses the strong correlation between the width of the scintillation light distribution within large continuous crystals and the γ-ray's interaction depth. This behavior was successfully reproduced by a theoretical model distribution based on the inverse square law. For the determination of the distribution's width, its standard deviation σ is computed using an enhanced position-sensitive proportional resistor network which is often used in γ-ray-imaging devices. Minor changes of this known resistor network allow the analog and real-time determination of the light distribution's 2nd moment without impairing the measurement of the energy and centroid. First experimental results are presented that confirm that the described method works correctly. Since only some cheap electronic components, but no additional detectors or crystals are required, the main advantage of this method is its low cost

  8. SiMPl - High efficient silicon photomultipliers with integrated bulk resistor

    International Nuclear Information System (INIS)

    Silicon photomultipliers (SiPM) are avalanche photodetectors which tend to replace conventional photomultiplier tubes in many application areas where detectors with high photon detection efficiency (PDE) are in the focus of interest. For Geiger mode operation high ohmic polysilicon is needed as quench resistor. On the one hand this forms a barrier for incident light, thus decreasing the PDE, which is a crucial point at low light levels. On the other hand it's also the most cost driving technological issue in fabrication. We present a novel design for a high efficient SiPM with the quench resistors integrated into the silicon bulk. Therefore obstacles for light like metal lines or contacts within the active area can be omitted and the fill factor of the device is only limited by the gaps necessary for optical crosstalk suppression. First results of this novel light detector are presented.

  9. Carbon Resistor Pressure Gauge Calibration at Stresses Up to 1 GPa

    Energy Technology Data Exchange (ETDEWEB)

    Vandersall, K S; Niles, A M; Greenwood, D W; Cunningham, B; Garcia, F; Forbes, J W

    2002-03-05

    Calibration of the 470-Ohm carbon resistor gauge is desired in the low stress region up to 1 GPa. A split-Hopkinson pressure bar, drop tower apparatus, gas pressure chamber, and gas gun have been used to perform the calibration experiments. The gauge behavior at elevated temperature was also investigated by heating the resistors to 200 C at atmospheric pressure while observing the resistance change. The motivation for this calibration work arises from the desire to increase the number of data points in the low stress regime to better establish the accuracy and precision of the gauge. Details of the various calibration arrangements and the results are discussed and compared to calibration curves fit to previously published calibration data. It was found that in most cases, the data from this work fit the calibration curves fit to previously published data rather well.

  10. Random-resistor network description for hopping transport in the presence of Hubbard interaction

    International Nuclear Information System (INIS)

    On the basis of the linearized rate equations for hopping electrons in the presence of Hubbard interaction we derive a random resistor network analogue of the transport equations. In contrast to the ordinary Miller-Abraham network our network has two nodes per site. The occurrence of the second node is related to the capability of the system to propagate excitations, and thus is characteristic for the interacting situation. Our random resistor network can be used for the investigation of the transport properties in alternating electric fields and for the investigation of properties of excitations. The network analogue is applied to the calculation of the dynamical conductivity in the nearest-neighbour hopping regime for all Hubbard-interaction strength

  11. Nonlinear random resistor diode networks and fractal dimensions of directed percolation clusters

    CERN Document Server

    Stenull, O; Stenull, Olaf; Janssen, Hans-Karl

    2001-01-01

    We study nonlinear random resistor diode networks at the transition from the non percolating to the directed percolating phase. The resistor-like bonds and the diode-like bonds under forward bias voltage obey a generalized Ohm's law, $V \\sim I^r$. Based on general grounds as symmetries and relevance we develop a field theoretic model. We focus on the average two-port resistance, which is governed at the transition by the resistance exponent $\\phi_r$. By employing renormalization group methods we calculate $\\phi_r$ for arbitrary $r$ to one-loop order. Then we address the fractal dimensions characterizing directed percolation clusters. Via considering distinct values of the nonlinearity $r$, we determine the dimension of the red bonds, the chemical path and the backbone to two-loop order.

  12. Recursion-transform approach to compute the resistance of a resistor network with an arbitrary boundary

    International Nuclear Information System (INIS)

    We consider a profound problem of two-point resistance in the resistor network with a null resistor edge and an arbitrary boundary, which has not been solved before because the Green’s function technique and the Laplacian matrix approach are invalid in this case. Looking for the exact solutions of resistance is important but difficult in the case of the arbitrary boundary since the boundary is a wall or trap which affects the behavior of a finite network. In this paper, we give a general resistance formula that is composed of a single summation by using the recursion-transform method. Meanwhile, several interesting results are derived by the general formula. Further, the current distribution is given explicitly as a byproduct of the method. (paper)

  13. Conductivity of a square-lattice bond-mixed resistor network

    International Nuclear Information System (INIS)

    Within a real-space renormalization-group framework based on self-dual clusters, the conductivity of a square-lattice quenched bond-random resistor network is calculated, the conductance on each bond being g1 or g2 with probabilities (1-p) and p respectively. The group recovers several already known exact results (including slopes), and is consequently believed to be numerically quite reliable for almost all values of p, and all ratios g1/g2 (in particular, g1=0 and g1=infinite with finite g2 respectively correspond to the insulator-resitor and superconductor-resistor mixtures). In addition to that, an heuristic analytic expression is proposed for the conductivity which is believed to be a quite satisfactory approximation everywhere not too close to the percolation point. (Author)

  14. Control of a fractional chaotic system based on a fractional-order resistorcapacitor filter

    International Nuclear Information System (INIS)

    We present a new fractional-order resistorcapacitor controller and a novel control method based on the fractional-order controller to control an arbitrary three-dimensional fractional chaotic system. The proposed control method is simple, robust, and theoretically rigorous, and its anti-noise performance is satisfactory. Numerical simulations are given for several fractional chaotic systems to verify the effectiveness and the universality of the proposed control method

  15. A Simulative Approach to Electron Conduction in Thick-Film Resistors

    OpenAIRE

    Rizzi, A.; Prudenziati, M.; Jacoboni, C.

    1983-01-01

    A simulative approach to the calculation of electrical transport in thick-film resistors is presented, in which electrons are considered to hop from and to metallic grains and localized states in the glass. For concentrations of metallic grains sufficiently low and of localized states sufficiently high, a maximum in conductivity as a function of temperature is obtained due to a balance between the tendency of temperature to favour hopping and to oppose an ordered response to an external force.

  16. A silicon microstrip detector with integrated coupling capacitors and polysilicon biasing resistors

    International Nuclear Information System (INIS)

    In this paper we report on the development of a silicon microstrip detector with integrated coupling capacitors and polysilicon biasing resistors. These new detectors show the same performance as standard detectors made at our laboratory with regard to leakage current and spatial resolution. Leakage currents as low as 200 pA/strip at 120 volts and a spatial resolution as good as 3.5 μm has been achieved. (author)

  17. Maximum Bandwidth Enhancement of Current Mirror using Series-Resistor and Dynamic Body Bias Technique

    Directory of Open Access Journals (Sweden)

    V. Niranjan

    2014-09-01

    Full Text Available This paper introduces a new approach for enhancing the bandwidth of a low voltage CMOS current mirror. The proposed approach is based on utilizing body effect in a MOS transistor by connecting its gate and bulk terminals together for signal input. This results in boosting the effective transconductance of MOS transistor along with reduction of the threshold voltage. The proposed approach does not affect the DC gain of the current mirror. We demonstrate that the proposed approach features compatibility with widely used series-resistor technique for enhancing the current mirror bandwidth and both techniques have been employed simultaneously for maximum bandwidth enhancement. An important consequence of using both techniques simultaneously is the reduction of the series-resistor value for achieving the same bandwidth. This reduction in value is very attractive because a smaller resistor results in smaller chip area and less noise. PSpice simulation results using 180 nm CMOS technology from TSMC are included to prove the unique results. The proposed current mirror operates at 1Volt consuming only 102 µW and maximum bandwidth extension ratio of 1.85 has been obtained using the proposed approach. Simulation results are in good agreement with analytical predictions.

  18. A study on embedded resistor components fabricated by laser micro-cladding and rapid prototype

    International Nuclear Information System (INIS)

    With the rapid development of IC and packaging, electronic devices are required to be smaller, to have a high-density integration, to become multifunction and to be of lower cost and high-reliability. Thick-film technology is not able to meet the current developing demands because of its shortcomings, such as the limit of pattern resolution, the severe torsion and delay of high-speed signal transmission. The speed and quality of signal transmission will be improved if embedded resistor components are directly integrated in the multiplayer substrate of multi-chip or laminated module, and high-density integration and reliability are achieved because the short interconnection and the less soldering point. In this paper, a technique named laser micro-cladding and rapid prototype is used to directly fabricate embedded resistor units on the multiplayer ceramic substrate without using a mask and high-temperature sintering, and without trimming resistor, which will simplify processing and decrease cost as well as improving high-speed and reliable performance

  19. Pyramidal resistor networks for electrical impedance tomography with partial boundary measurements

    International Nuclear Information System (INIS)

    We introduce an inversion algorithm for electrical impedance tomography (EIT) with partial boundary measurements in two dimensions. It gives stable and fast reconstructions using sparse parameterizations of the unknown conductivity on optimal grids that are computed as part of the inversion. We follow the approach in Borcea et al (2008 Inverse Problems 24 035013) and Vasquez (2006 PhD thesis Rice University, Houston, TX, USA) that connects inverse discrete problems for resistor networks to continuum EIT problems, using optimal grids. The algorithm in Borcea et al (2008 Inverse Problems 24 035013) and Vasquez (2006 PhD Thesis Rice University, Houston, TX, USA) is based on circular resistor networks, and solves the EIT problem with full boundary measurements. It is extended in Borcea et al (2010 Inverse Problems 26 045010) to EIT with partial boundary measurements, using extremal quasi-conformal mappings that transform the problem to one with full boundary measurements. Here we introduce a different class of optimal grids, based on resistor networks with pyramidal topology, that is better suited for the partial measurements setup. We prove the unique solvability of the discrete inverse problem for these networks and develop an algorithm for finding them from the measurements of the Dirichlet to Neumann map. Then, we show how to use the networks to define the optimal grids and to approximate the unknown conductivity. We assess the performance of our approach with numerical simulations and compare the results with those in Borcea et al (2010)

  20. History of resistor array infrared projectors: hindsight is always 100% operability

    Science.gov (United States)

    Williams, Owen M.; Goldsmith, George C., II; Stockbridge, Robert G.

    2005-05-01

    Numerous infrared scene projection technologies have been investigated since the 1970s. Notably, from the late 1980s the development of the first resistor array infrared projectors gained leverage from the strong concurrent developments within focal plane array imaging technology, linked by the common need for large integrated circuits comprising a 2-dimensional array of interconnected unit cells. In the resistor array case, it is the unit cell comprising the resistively heated emitter and its dedicated drive circuit that determines the projector response to its associated scene generator commands. In this paper we review the development of resistor array technology from a historical perspective, concentrating on the unit cell developments. We commence by describing the technological innovations that forged the way, sharing along the way stories of the successes and failures, all of which contributed to the steady if somewhat eventful growth of the critical knowledge base that underpins the strength of today's array technology. We conclude with comments on the characteristics and limitations of the technology and on the prospects for future array development.

  1. Chaos, brain and divided consciousness.

    Science.gov (United States)

    Bob, Petr

    2007-01-01

    Modern trends in psychology and cognitive neuroscience suggest that applications of nonlinear dynamics, chaos and self-organization seem to be particularly important for research of some fundamental problems regarding mind-brain relationship. Relevant problems among others are formations of memories during alterations of mental states and nature of a barrier that divides mental states, and leads to the process called dissociation. This process is related to a formation of groups of neurons which often synchronize their firing patterns in a unique spatial maner. Central theme of this study is the relationship between level of moving and oscilating mental processes and their neurophysiological substrate. This opens a question about principles of organization of conscious experiences and how these experiences arise in the brain. Chaotic self-organization provides a unique theoretical and experimental tool for deeper understanding of dissociative phenomena and enables to study how dissociative phenomena can be linked to epileptiform discharges which are related to various forms of psychological and somatic manifestations. Organizing principles that constitute human consciousness and other mental phenomena from this point of view may be described by analysis and reconstruction of underlying dynamics of psychological or psychophysiological measures. These nonlinear methods in this study were used for analysis of characteristic changes in EEG and bilateral electrodermal activity (EDA) during reliving of dissociated traumatic and stressful memories and during psychopathological states. Analysis confirms a possible role of chaotic transitions in the processing of dissociated memory. Supportive finding for a possible chaotic process related to dissociation found in this study represent also significant relationship of dissociation, epileptiform discharges measured by typical psychopathological manifestations and characteristic laterality changes in bilateral EDA in patients with schizophrenia and depression. Increased level of psychopathological symptoms indicates close relationship to the right-left EDA asymmetry and asymmetry of information entropy calculated by non-linear recurrence quantification analysis of EDA records. Because epileptiform activity has specific chaotic behaviour and calculated information entropy from EDA records reflects the complexity of the deterministic structure in the system there is a relevant assumption that unilaterally increased complexity may produce interhemispheric disbalance and increased chaoticity which hypothetically may serve as a dynamic source of epileptiform discharges related to trauma induced kindling mechanism. Specific form of chaotic inner organization which cannot be explained only as a consequence of external causality support also psychophysiological data that lead to the so-called self-organizing theory of dreaming by Kahn and Hobson. This study suggests that self-organizing theory of dreaming is particularly important with respect to problem of memory formation and processing during dissociative states characteristic for dreams. Recent data and also findings of this study support the research utility of chaos theory in psychology and neuroscience, and also its conceptual view of dynamic ordering factors and self-organization underlying psychological processes and brain physiology. PMID:17867519

  2. X-Ray Characterization of Resistor/Dielectric Material for Low Temperature Co-Fired Ceramic Packages

    International Nuclear Information System (INIS)

    High temperature XRD has been employed to monitor the devitrification of Dupont 951 low temperature co-fired ceramic (LTCC) and Dupont E84005 resistor ink. The LTCC underwent devitrification to an anorthite phase in the range of 835-875 C with activation energy of 180 kJ/mol as calculated from kinetic data. The resistor paste underwent devitrification in the 835-875 C range forming monoclinic and hexagonal celcian phases plus a phase believed to be a zinc-silicate. RuO(sub 2) appeared to be stable within this devitrified resistor matrix. X-ray radiography of a co-fired circuit indicated good structural/chemical compatibility between the resistor and LTCC

  3. Power Divider for Waveforms Rich in Harmonics

    Science.gov (United States)

    Sims, William Herbert, III

    2005-01-01

    A method for dividing the power of an electronic signal rich in harmonics involves the use of an improved divider topology. A divider designed with this topology could be used, for example, to propagate a square-wave signal in an amplifier designed with a push-pull configuration to enable the generation of more power than could be generated in another configuration.

  4. 40 CFR 1065.248 - Gas divider.

    Science.gov (United States)

    2010-07-01

    ... testing. You may use critical-flow gas dividers, capillary-tube gas dividers, or thermal-mass-meter gas... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Measurement Instruments Flow-Related Measurements § 1065.248 Gas divider. (a) Application. You...

  5. The First and Second Digital Divides.

    Science.gov (United States)

    Attewell, Paul

    2001-01-01

    Describes the digital divide, the technology gap between the people who have technology (information haves) and those without technology (information have-nots). Discusses that the first digital divide is access to technology; and addresses the second digital divide, computer use, focusing on computers at school and at home. (CMK)

  6. Diversity, Disability, and Geographic Digital Divide

    Science.gov (United States)

    Sumari, Melati; Carr, Erika; Ndebe-Ngovo, Manjerngie

    2006-01-01

    The phenomenon called digital divide was the focus of this paper. Diversity, disability, and geographical digital divide were relevant to this collaborative project. An extensive review of the literature was conducted for the completion of this project. The evidence for the digital divide in terms of race, level of education, and gender in the

  7. The Myth about the Digital Divide

    Science.gov (United States)

    Hawkins, Brian L.; Oblinge, Diana G.

    2006-01-01

    Although computer ownership is not 100 percent, progress has been made on closing the digital divide. However, defining the digital divide according to the haves and have-nots of computer ownership is only a starting point. Beyond computer ownership, colleges and universities should explore the "second-level digital divide," which can be caused by

  8. Tech, Teachers & Teens: Bridging the Divide

    Science.gov (United States)

    Stuht, Amy Colcord; Colcord, Cean

    2011-01-01

    In past decades, the "digital divide" referred to the gap between those who could afford access to technology and those who could not. The divide has shifted in recent years to reflect the growing technological chasm between teachers and their students: today's schools and teenagers' worlds. The digital divide is widening and deepening

  9. Comparing Internet and Mobile Phone Digital Divides.

    Science.gov (United States)

    Rice, Ronald E.; Katz, James E.

    2002-01-01

    Discussion of the digital divide focuses on the Internet and mobile phone digital divide. Analyses of a telephone survey from 2000 considers similarities and differences in three kinds of digital dividers for both the Internet and the mobile phone: users and nonusers, users and dropouts, and recent and veteran users. (Author/LRW)

  10. Next generation KATRIN high precision voltage divider for voltages up to 65kV

    CERN Document Server

    Bauer, S; Hochschulz, F; Ortjohann, H -W; Rosendahl, S; Thümmler, T; Schmidt, M; Weinheimer, C

    2013-01-01

    The KATRIN (KArlsruhe TRItium Neutrino) experiment aims to determine the mass of the electron antineutrino with a sensitivity of 200meV by precisely measuring the electron spectrum of the tritium beta decay. This will be done by the use of a retarding spectrometer of the MAC-E-Filter type. To achieve the desired sensitivity the stability of the retarding potential of -18.6kV has to be monitored with a precision of 3ppm over at least two months. Since this is not feasible with commercial devices, two ppm-class high voltage dividers were developed, following the concept of the standard divider for DC voltages of up to 100kV of the Physikalisch-Technische Bundesanstalt (PTB). In order to reach such high accuracies different effects have to be considered. The two most important ones are the temperature dependence of resistance and leakage currents, caused by insulators or corona discharges. For the second divider improvements were made concerning the high-precision resistors and the thermal design of the divider....

  11. A 1-GHz, 7-mW, 8-Bit Subranging ADC without Resistor Ladder Using Built-In Threshold Calibration

    OpenAIRE

    Kenichi Ohhata; Wataru Yoshimura; Daiki Tabira; Futoshi Shimozono; Masataro Iwamoto

    2014-01-01

    A subranging analog-to-digital converter (ADC) features high-speed and relatively low-power. The limiting factors of power reduction in subranging ADCs are the resistor ladder and the comparator. We propose an ADC architecture combining a capacitive digital-to-analog convertor and built-in threshold calibration to eliminate the resistor ladder, resulting in a low-power subranging ADC. We also propose a calibration technique comprising of metal-oxide-metal capacitor, MOS...

  12. Low-Value Nickel Resistors Electroless-Plated on “IMST” Substrate for Power Hybrid ICs

    OpenAIRE

    Kazami, A.; Y. Fuura; Miura, N

    1981-01-01

    This paper describes a new resistor formation technique, characterized by the use of our unique hybrid IC substrate (IMST substrate) and the electroless nickel plating on it.The evaluation of various electroless nickel plating baths to deposit nickel alloy with a different composition for each is included. The resistor properties of the nickel film from a selected bath are showed. The plating conditions affecting the resistance are discussed. Finally, the application to the built-in emitter r...

  13. Logic Gates Made of N-Channel JFETs and Epitaxial Resistors

    Science.gov (United States)

    Krasowski, Michael J.

    2008-01-01

    Prototype logic gates made of n-channel junction field-effect transistors (JFETs) and epitaxial resistors have been demonstrated, with a view toward eventual implementation of digital logic devices and systems in silicon carbide (SiC) integrated circuits (ICs). This development is intended to exploit the inherent ability of SiC electronic devices to function at temperatures from 300 to somewhat above 500 C and withstand large doses of ionizing radiation. SiC-based digital logic devices and systems could enable operation of sensors and robots in nuclear reactors, in jet engines, near hydrothermal vents, and in other environments that are so hot or radioactive as to cause conventional silicon electronic devices to fail. At present, current needs for digital processing at high temperatures exceed SiC integrated circuit production capabilities, which do not allow for highly integrated circuits. Only single to small number component production of depletion mode n-channel JFETs and epitaxial resistors on a single substrate is possible. As a consequence, the fine matching of components is impossible, resulting in rather large direct-current parameter distributions within a group of transistors typically spanning multiples of 5 to 10. Add to this the lack of p-channel devices to complement the n-channel FETs, the lack of precise dropping diodes, and the lack of enhancement mode devices at these elevated temperatures and the use of conventional direct coupled and buffered direct coupled logic gate design techniques is impossible. The presented logic gate design is tolerant of device parameter distributions and is not hampered by the lack of complementary devices or dropping diodes. In addition to n-channel JFETs, these gates include level-shifting and load resistors (see figure). Instead of relying on precise matching of parameters among individual JFETS, these designs rely on choosing the values of these resistors and of supply potentials so as to make the circuits perform the desired functions throughout the ranges over which the parameters of the JFETs are distributed. The supply rails V(sub dd) and V(sub ss) and the resistors R are chosen as functions of the distribution of direct-current operating parameters of the group of transistors used.

  14. Miniaturized Wilkinson Power Dividers Utilizing Capacitive Loading

    Science.gov (United States)

    Scardelletti, Maximilian C.; Ponchak, George E.; Weller, Thomas M.

    2001-01-01

    This letter reports the miniaturization of a planar Wilkinson power divider by capacitive loading of the quarter wave transmission lines employed in conventional Wilkinson power dividers. Reduction of the transmission line segments from lambda/4 to between lambda/5 and lambda/12 are reported here. The input and output lines at the three ports and the lines comprising the divider itself are coplanar waveguide (CPW) and asymmetric coplanar stripline (ACPS), respectively. The 10 GHZ power dividers are fabricated on high resistivity silicon (HRS) and alumina wafers. These miniaturized dividers are 74% smaller than conventional Wilkinson power dividers, and have a return loss better than +30 dB and an insertion loss less than 0.55 dB. Design equations and a discussion about the effect of parasitic reactance on the isolation are presented for the first time.

  15. Re-conceptualizing the Global Digital Divide

    OpenAIRE

    Burri, Mira

    2011-01-01

    The article seeks a re-conceptualization of the global digital divide debate. It critically explores the predominant notion, its evolution and measurement, as well as the policies that have been advanced to bridge the digital divide. Acknowledging the complexity of this inequality, the article aims at analyzing the disparities beyond the connectivity and skills barriers. Without understating the first two digital divides, it is argued that as the Internet becomes more sophisticate...

  16. Exploring Digital Divide in the Maldives

    OpenAIRE

    Shareef, Mohamed; Ojo, Adegboyega; JANOWSKI, TOMASZ

    2010-01-01

    The central role of ICT in development and its ethical implications have kept the longstanding discussions of the Digital Divide active in the international development and research communities, with new perspectives on how to measure and interpret this inequality. In this paper, we examine the nature of the Digital Divide in the Maldives - between the nation's capital and the Atolls, between the Atolls and across the nation, and the evolution of these divides over time. In order to inform mo...

  17. Power Divider for Harmonically Rich Waveforms

    Science.gov (United States)

    Sims, William Herbert, III (Inventor)

    2001-01-01

    A power divider divides an RF signal into two output signals having a phase difference of 180 deg. or a multiple thereof. When the RF signal is a square wave or another harmonically rich signal. the phases of the fundamental and the harmonics have the proper relationship. The divider can be implemented in the form of microstrips on a board, with one of the output microstrips having several bends to provide a different electrical length from the other.

  18. Design, development and evaluation of a resistor-based multiplexing circuit for a 20×20 SiPM array

    Science.gov (United States)

    Wang, Zhonghai; Sun, Xishan; Lou, Kai; Meier, Joseph; Zhou, Rong; Yang, Chaowen; Zhu, Xiaorong; Shao, Yiping

    2016-04-01

    One technical challenge in developing a large-size scintillator detector with multiple Silicon Photomultiplier (SiPM) arrays is to read out a large number of detector output channels. To achieve this, different signal multiplexing circuits have been studied and applied with different performances and cost-effective tradeoffs. Resistor-based multiplexing circuits exhibit simplicity and signal integrity, but also present the disadvantage of timing shift among different channels. In this study, a resistor-based multiplexing circuit for a large-sized SiPM array readout was developed and evaluated by simulation and experimental studies. Similarly to a multiplexing circuit used for multi-anode PMT, grounding and branching resistors were connected to each SiPM output channel. The grounding resistor was used to simultaneously reduce the signal crosstalk among different channels and to improve timing performance. Both grounding and branching resistor values were optimized to maintain a balanced performance of the event energy, timing, and positioning. A multiplexing circuit was implemented on a compact PCB and applied for a flat-panel detector which consisted of a 32×32 LYSO scintillator crystals optically coupled to 5×5 SiPM arrays for a total 20×20 output channels. Test results showed excellent crystal identification for all 1024 LYSO crystals (each with 2×2×30 mm3 size) with 22Na flood-source irradiation. The measured peak-to-valley ratio from typical crystal map profile is around 3:1 to 6.6:1, an average single crystal energy resolution of about 17.3%, and an average single crystal timing resolution of about 2 ns. Timing shift among different crystals, as reported in some other resistor-based multiplexing circuit designs, was not observed. In summary, we have designed and implemented a practical resistor-based multiplexing circuit that can be readily applied for reading out a large SiPM array with good detector performance.

  19. Random-Resistor-Random-Temperature Kirchhoff-Law-Johnson-Noise (RRRT-KLJN Key Exchange

    Directory of Open Access Journals (Sweden)

    Kish Laszlo B.

    2016-03-01

    Full Text Available We introduce two new Kirchhoff-law-Johnson-noise (KLJN secure key distribution schemes which are generalizations of the original KLJN scheme. The first of these, the Random-Resistor (RR- KLJN scheme, uses random resistors with values chosen from a quasi-continuum set. It is well-known since the creation of the KLJN concept that such a system could work in cryptography, because Alice and Bob can calculate the unknown resistance value from measurements, but the RR-KLJN system has not been addressed in prior publications since it was considered impractical. The reason for discussing it now is the second scheme, the Random Resistor Random Temperature (RRRT- KLJN key exchange, inspired by a recent paper of Vadai, Mingesz and Gingl, wherein security was shown to be maintained at non-zero power flow. In the RRRT-KLJN secure key exchange scheme, both the resistances and their temperatures are continuum random variables. We prove that the security of the RRRT-KLJN scheme can prevail at a non-zero power flow, and thus the physical law guaranteeing security is not the Second Law of Thermodynamics but the Fluctuation-Dissipation Theorem. Alice and Bob know their own resistances and temperatures and can calculate the resistance and temperature values at the other end of the communication channel from measured voltage, current and power-flow data in the wire. However, Eve cannot determine these values because, for her, there are four unknown quantities while she can set up only three equations. The RRRT-KLJN scheme has several advantages and makes all former attacks on the KLJN scheme invalid or incomplete.

  20. Generalized Kirchhoff-Law-Johnson-Noise (KLJN) secure key exchange system using arbitrary resistors

    CERN Document Server

    Vadai, Gergely; Gingl, Zoltan

    2015-01-01

    The Kirchhoff-Law-Johnson-Noise (KLJN) secure key exchange system has been introduced as a simple, very low cost and efficient classical physical alternative to quantum key distribution systems. The ideal system uses only a few electronic components - identical resistor pairs, switches and interconnecting wires - to guarantee perfectly protected data transmission. We show that a generalized KLJN system can provide unconditional security even if it is used with significantly less limitations. The more universal conditions ease practical realizations considerably and support more robust protection against attacks. Our theoretical results are confirmed by numerical simulations.

  1. Silicon avalanche photodiodes on the base of metal-resistor-semiconductor (MRS) structures

    CERN Document Server

    Saveliev, V

    2000-01-01

    The development of a high quantum efficiency, fast photodetector, with internal gain amplification for the wavelength range 450-600 nm is one of the critical issues for experimental physics - registration of low-intensity light photons flux. The new structure of Silicon Avalanche Detectors with high internal amplification (10 sup 5 -10 sup 6) has been designed, manufactured and tested for registration of visible light photons and charge particles. The main features of Metal-Resistor-Semiconductor (MRS) structures are the high charge multiplication in nonuniform electric field near the 'needle' pn-junction and negative feedback for stabilization of avalanche process due to resistive layer.

  2. Silicon avalanche photodiodes on the base of metal-resistor-semiconductor (MRS) structures

    International Nuclear Information System (INIS)

    The development of a high quantum efficiency, fast photodetector, with internal gain amplification for the wavelength range 450-600 nm is one of the critical issues for experimental physics - registration of low-intensity light photons flux. The new structure of Silicon Avalanche Detectors with high internal amplification (105-106) has been designed, manufactured and tested for registration of visible light photons and charge particles. The main features of Metal-Resistor-Semiconductor (MRS) structures are the high charge multiplication in nonuniform electric field near the 'needle' pn-junction and negative feedback for stabilization of avalanche process due to resistive layer

  3. High voltage efficient lighting based on the loss-free resistor concept.

    OpenAIRE

    León Masich, Antonio

    2015-01-01

    En esta tesis se usa la noción de resistor libre de pérdidas (LFR) para diseñar fuentes de alimentación destinadas iluminación eficiente como por ejemplo light emmiting diodes (LEDs), lamparas de alta intensidad de descarga (HID) y lámparas de inducción sin electrodos (IEFL), con el fin de reducir el consumo eléctrico tanto en aplicaciones domésticas como industriales. Aprovechando la naturaleza del LFR, es decir, una resistencia emulada en el puerto de entrada y una fuente de potencia ...

  4. Zero-point energy in the Johnson noise of resistors: Is it there?

    CERN Document Server

    Kish, Laszlo B

    2015-01-01

    There is a longstanding debate about the zero-point term in the Johnson noise voltage of a resistor: Is it indeed there or is it only an experimental artifact due to the uncertainty principle for phase-sensitive amplifiers? We show that, when the zero-point term is measured by the mean energy and force in a shunting capacitor and, if these measurements confirm its existence, two types of perpetual motion machines could be constructed. Therefore an exact quantum theory of the Johnson noise must include also the measurement system used to evaluate the observed quantities. The results have implications also for phenomena in advanced nanotechnology.

  5. Enhancement in nonlinear transport in percolating superconductor nonlinear resistor networks. A universality phenomenon

    International Nuclear Information System (INIS)

    In this note we consider the geometrical effects of a percolating system on the nonlinear transport properties in a superconductor-normal conductor nonlinear resistor network. For realistic composites, the nonlinearity may play an important role in the electrical transport phenomena. A typical example consists of studying a nonlinear composite medium in which an inclusion with nonlinear current-field (J-E) characteristics is randomly embedded in a host with either linear or nonlinear J-E response. For such a system, substantial progress in studies of the effective nonlinear response has been made in the past few years

  6. Study of charge transport in highly conducting polymers based on a random resistor network

    International Nuclear Information System (INIS)

    Based on a random resistor network (RRN), we study the unusual ac conductivity ?(?) of highly conducting polymer such as PF6 doped polypyrrole. The system is modeled as a composite medium consisting of metallic regions randomly distributed in the amorphous parts. Within the metallic regions, the polymer chains are regularly and densely packed, outside which the poorly arranged chains form amorphous host. The metallic grains are connected by resonance quantum tunneling, which occurs through the strongly localized states in the amorphous media. ?(?), calculated from this model, reproduces the main experimental features associated with the metal-insulator transition in these polymers

  7. Social Welfare Implications of the Digital Divide

    Science.gov (United States)

    Kim, Eunjin; Lee, Byungtae; Menon, Nirup M.

    2009-01-01

    The Internet plays a critical role in informing individuals about society, politics, business, and the environment. So much so that it has been said that the digital divide makes the segment of society on the ''right side'' of the divide (the digitally endowed group) better off and that on the ''wrong side'' (the digitally challenged group) worse…

  8. Fundamental Limitations Of Passive Power Dividers

    Science.gov (United States)

    Antsos, Dimitrios

    1995-01-01

    Report presents novel theoretical analysis of performance of passive, multiport power dividers like those used to distribute power to radiating elements of array antennas. Typically, unit cell of power-divider network is three- or four-port subnetwork with one port terminated, and subnetworks of network cascaded in multiple layers, so that insertion losses are of major concern.

  9. Development of high power RF divider

    International Nuclear Information System (INIS)

    High power multi antenna RF heating system has been developed. The RF power of 500 KW (f = 7 - 28 MHz) is divided into twelve lines by means of 3 db coupler and two six channel power dividers, and those are fed to the twelve ICRF antennas through impedance matching circuits. (author)

  10. Social Welfare Implications of the Digital Divide

    Science.gov (United States)

    Kim, Eunjin; Lee, Byungtae; Menon, Nirup M.

    2009-01-01

    The Internet plays a critical role in informing individuals about society, politics, business, and the environment. So much so that it has been said that the digital divide makes the segment of society on the ''right side'' of the divide (the digitally endowed group) better off and that on the ''wrong side'' (the digitally challenged group) worse

  11. Bridge the Digital Divide for Educational Equity

    Science.gov (United States)

    Mason, Christine Y.; Dodds, Richard

    2005-01-01

    Students' technological savvy has challenged schools to make greater use of computers and the Internet in their curricula, but unfortunately, not every student has the same access to it, and the inability to keep pace has created a digital divide that continues to widen. The digital divide particularly affects students who are black, Hispanic,

  12. Thermometry using 1/8 W carbon resistors in a temperature region around 10 mK

    International Nuclear Information System (INIS)

    The resistance-temperature characteristics of 1/8 W carbon resistors of grade ERC-18SG, manufactured by Matsushita, with the nominal values of 48, 82, 100, 220 and 330 Ω have been measured in the region 4.2 K to 25 mK and their application as thermometers in this region is confirmed. For the 82 Ω resistor, measurements were taken at temperatures below 10mK. The temperature dependence of the resistance was found to be linear on the log-log plot over a wide range below 50 mK. The sensitivity remains finite even at 6 mK, but below 10 mK rapid measurements were prevented by a considerable increase in the thermal relaxation time. Measurement of the characteristics of several 100 Ω resistors from two different sets showed that resistors from the same set separate into two groups with different characteristics. This become appreciable at temperatures below 4.2 K, so it is difficult to predict the behaviour of Matsushite resistors below 4.2 K from the characteristics at higher temperatures. (author)

  13. Silicon photomultipliers with bulk-integrated quenching resistor: first results of characterization

    International Nuclear Information System (INIS)

    For future experiments in high energy physics detectors with high photon detection efficiencies (PDE) and ability to work in high magnetic fields are in the focus of research. Silicon photomultipliers (SiPM), arrays of Geiger-mode avalanche photodiodes, tend to replace conventional photomultiplier tubes in many applications. Conventional SiPMs use high-ohmic polysilicon as quenching resistor, which forms a barrier for incident light, thus decreasing the PDE. Furthermore it's also one of the cost driving technological issues in fabrication. By integrating the quenching resistor into the silicon bulk obstacles for light within the active area can be omitted and the fill factor of the device is only limited by the gaps necessary for optical crosstalk suppression. So this device is a promising candidate to achieve maximum PDE of up to 70%. In addition the absence of lateral high field regions on surface should improve the radiation hardness of the device. Results of the characterization of the in-house prototype production are presented.

  14. SiMPl-An avalanche diode array with bulk integrated quench resistors for single photon detection

    International Nuclear Information System (INIS)

    The so-called silicon photomultipliers (SiPMs, MPPCs, etc.) are already replacing photomultiplier tubes in many applications. Still the reproducibility and the cost requirements are not at the level required for the coverage of many square meters of detector area. Therefore a simple technology is desired which allows a high yield and keeps the detector costs in a reasonable range. In the existing devices the need of high ohmic polysilicon for the quench resistors is one of the most yield and cost driving technological issues. We are proposing a front-side illuminated detector structure with quench resistors integrated into the silicon bulk. In this concept other obstacles for light like metal lines or contacts can be omitted and therefore the fill factor is only limited by the gaps necessary for optical cross-talk suppression. Within the array the entire surface area remains non-structured and can be easily coated with an anti-reflective layer. Compared to existing devices the proposed detector has the potential of higher photon detection efficiency especially in the blue and the UV range, an improved hardness against ionizing radiation and a much simpler processing resulting in a higher production yield and lower costs. The quenching mechanism has been demonstrated in a proof-of-principle production performed in house. The second prototype fabrication on silicon on isolator substrates has been done and allows testing of the device performance. The results from the first measurements are presented.

  15. Pushing beyond resistors and constipators: implementation considerations for infection prevention best practices.

    Science.gov (United States)

    Bearman, Gonzalo; Stevens, Michael P

    2014-01-01

    Despite increased knowledge in the science of infection prevention, the implementation of evidence-based best practices remains a challenge. The dissemination of infection prevention risk reduction best practices should be approached with flexibility and a collaborative perspective. High-quality evidence and cost assessments to support interventions are important initial considerations. An implementation framework should be contextually appropriate, take into account an organization's culture, and be mindful of an approach that minimizes complexity. Trialing an intervention within a specific unit may later lead to increased uptake organization wide. Highly functional collaborations with effective leaders are needed for successful implementation. Leadership for infection prevention initiatives may include upper level management; however, hospital epidemiologists and infection preventionists often play this role. Although published data fail to identify a single best integrative strategy for infection prevention practice change, success has been associated with education initiatives and seminars, audit and feedback, distribution of educational materials, marketing, mass media, positive deviance, and the employment of champions, facilitators, role models, and opinion leaders. Local personnel, such as organizational resistors and constipators, can be barriers to idea dissemination and implementation. In addition to a thoughtfully conceived implementation strategy, dealing with infection prevention resistors and constipators includes getting their buy-in early in the dissemination process, working around them, or terminating their employment. More data are needed to best define which infection prevention dissemination strategies are most effective. PMID:24407546

  16. Accurate SPICE Modeling of Poly-silicon Resistor in 40nm CMOS Technology Process for Analog Circuit Simulation

    Directory of Open Access Journals (Sweden)

    Sun Lijie

    2015-01-01

    Full Text Available In this paper, the SPICE model of poly resistor is accurately developed based on silicon data. To describe the non-linear R-V trend, the new correlation in temperature and voltage is found in non-silicide poly-silicon resistor. A scalable model is developed on the temperature-dependent characteristics (TDC and the temperature-dependent voltage characteristics (TDVC from the R-V data. Besides, the parasitic capacitance between poly and substrate are extracted from real silicon structure in replacing conventional simulation data. The capacitance data are tested through using on-wafer charge-induced-injection error-free charge-based capacitance measurement (CIEF-CBCM technique which is driven by non-overlapping clock generation circuit. All modeling test structures are designed and fabricated through using 40nm CMOS technology process. The new SPICE model of poly-silicon resistor is more accurate to silicon for analog circuit simulation.

  17. Thermal analysis and temperature characteristics of a braking resistor for high-speed trains for changes in the braking current

    Science.gov (United States)

    Lee, Dae-Dong; Kang, Hyun-Il; Shim, Jae-Myung

    2015-09-01

    Electric brake systems are used in high-speed trains to brake trains by converting the kinetic energy of a railway vehicle to electric energy. The electric brake system consists of a regenerative braking system and a dynamic braking system. When the electric energy generated during the dynamic braking process is changed to heat through the braking resistor, the braking resistor can overheat; thus, failures can occur to the motor block. In this paper, a braking resistor for a high-speed train was used to perform thermal analyses and tests, and the results were analyzed. The analyzed data were used to estimate the dependence of the brake currents and the temperature rises on speed changes up to 300 km/h, at which a test could not be performed.

  18. Crossing the Digital Divide: Strategies and Implications

    OpenAIRE

    Speirs Plettner, Martha

    2001-01-01

    The global digital divide is a phenomenon which separates East from West. Responding to change is extremely important for the survival of humankind. This applies to the effort to close the divide. It will widen if the appropriate strategies and applications are not implemented in a timely way. Then the group on the less privileged side of the divide will find it harder and harder to cross to the other side. We need to see strategies put into action which will allow a post-digital literacy, on...

  19. Fractal patterns related to dividing coins

    International Nuclear Information System (INIS)

    The present paper formulates and solves a problem of dividing coins. The basic form of the problem seeks the set of the possible ways of dividing coins of face values 1,2,4,8,… between three people. We show that this set possesses a nested structure like the Sierpinski-gasket fractal. For a set of coins with face values power of r, the number of layers of the gasket becomes r. A higher-dimensional Sierpinski gasket is obtained if the number of people is more than three. In addition to Sierpinski-type fractals, the Cantor set is also obtained in dividing an incomplete coin set between two people

  20. Cortical responses to sustained and divided attention in Alzheimer's disease

    DEFF Research Database (Denmark)

    Johannsen, Peter; Jakobsen, Johannes Klitgaard; Bruhn, Peter; Gjedde, A

    Neuropsychological data suggests that divided attention is more impaired than sustained attention during the early phases of Alzheimer's disease. The purpose of the present study was to compare cerebral activation patterns during sustained and divided attention between Alzheimer patients and...... healthy elderly. The O-15-water PET activation method was used to map sustained and divided attention in 16 patients with Alzheimer's disease (mean age +/- SD: 68 +/- 5 years; MMSE: 11-25, mean +/- SD = 19.5 +/- 4.9) and in 16 healthy age-matched control subjects. After stereotactical normalization, voxel......, whereas the anterior cingulate gyrus was activated during sustained attention only. Only medial frontal structures (Brodmann Area (BA) 32/34) were activated in Alzheimer patients, and both frontal (BA-10), posterior cingulate (BA-23/31), and subcortical sites were deactivated. Compared to the healthy...

  1. High-power microwave power divider concept

    Science.gov (United States)

    Kolbly, R. B.

    1969-01-01

    Variable power divider keeps microwave transmitter at full power. This preserves the bandwidth and modulation characteristics and proportions any amount of the full power from the normal antenna into a dissipative load.

  2. The Digital Divide: It's the Content Stupid

    OpenAIRE

    Guadamuz, Andres

    2005-01-01

    The article examines the notion of the digital divide, not purely from physical access to the Internet, but from availability to online content. It focusses particularly on concerns held by developing countries, and of intellectual property and copyright.

  3. The two-point resistance of a resistor network: a new formulation and application to the cobweb network

    Science.gov (United States)

    Izmailian, N. Sh; Kenna, R.; Y Wu, F.

    2014-01-01

    We consider the problem of two-point resistance in a resistor network previously studied by one of us (Wu 2004 J. Phys. A: Math. Gen. 37 6653). By formulating the problem differently, we obtain a new expression for the two-point resistance between two arbitrary nodes which is simpler and can be easier to use in practice. We apply the new formulation to the cobweb resistor network to obtain the resistance between two nodes in the network. Particularly, our results prove a recently proposed conjecture on the resistance between the center node and a node on the network boundary. Our analysis also solves the spanning tree problem on the cobweb network.

  4. The two-point resistance of a resistor network: a new formulation and application to the cobweb network

    OpenAIRE

    Izmailian, N. Sh.; Kenna, R.; Wu, F.Y.

    2014-01-01

    We consider the problem of two-point resistance in a resistor network previously studied by one of us [F. Y. Wu, J. Phys. A {\\bf 37}, 6653 (2004)]. By formulating the problem differently, we obtain a new expression for the two-point resistance between two arbitrary nodes which is simpler and can be easier to use in practice. We apply the new formulation to the cobweb resistor network to obtain the resistance between two nodes in the network. Particularly, our results prove a recently proposed...

  5. Generational Divide, Music Consumption and Lifestyle Correlates

    OpenAIRE

    Filimon, Nela; Lopez-Sintas,Jordi

    2011-01-01

    This paper offers a social interpretation of the generational divide emerging from Spaniards' patterns of accessing music and their socioeconomic correlates. The three robust music consumer segments (inactive, buyer and downloader), determined with latent class models, suggest a digital generational divide in the music consumption behaviour: young-students are the main actors in the digital space, preferring to freely download the music consumed, while the adult buyers satisfy their musical p...

  6. How to bridge the digital divide?

    OpenAIRE

    Eriksen, Bodil Amalie

    2011-01-01

    The digital divide isa global problem, which several stateshave to face in their efforts to implement more e-governance. This thesis focuseson how a state can work to raise the level of the citizens' IT-skills so that citizens can become an active part of the information society. The focus is on how the Danish digital divide is defined in accordance to a theoretical framework, present empirical data and a political perspective. In addition the existing political initiatives to bri...

  7. Error analysis for thermonuclear plasma bolometric measurements performed with widely used miniaturized metal resistor detectors

    Science.gov (United States)

    Cecconello, M.; Marrelli, L.; Murari, A.; Martin, P.; Mast, K. F.

    1998-04-01

    A general qualitative and quantitative analysis of the experimental and numerical errors which affect the plasma total radiated power measurements performed in thermonuclear fusion experiments with widely used miniaturized low-noise metal resistor bolometers is presented in this paper. This analysis, which generalizes the results of previous work on the detection limit, is motivated by the fact that, by means of bolometric tomography, detailed reconstruction of the radiated power emissivity distributions, in particular during fast phenomena, requires a high level of precision in the raw measurement and then a thorough control of the error sources. Since these bolometers are widely used in the largest tokamak, RFP and Stellarator experiments and are also considered for the reference design of the bolometric diagnostics in the International Thermonuclear Experimental Reactor (ITER), the study presented here has been accomplished in a machine-independent way. Practical formulae and methods to estimate the experimental errors that do not depend on the magnetic configuration are presented.

  8. Thermal Properties Of Thick Film Structures Resistor оn Dielectric

    OpenAIRE

    Jakukowska, M.; Kalita, W,; Lozbin, V.

    2003-01-01

    Описано результати дослідження теплових властивостей різноманітних товстоплівкових структур “резистор на діелектрику”. The results of experimental investigations for thermal properties of thick-film structures “resistor on dielectric” are considered in the paper.

  9. The 'emergent scaling' phenomenon and the dielectric properties of random resistor-capacitor networks

    CERN Document Server

    Bouamrane, R

    2003-01-01

    An efficient algorithm, based on the Frank-Lobb reduction scheme, for calculating the equivalent dielectric properties of very large random resistor-capacitor (R-C) networks has been developed. It has been used to investigate the network size and composition dependence of dielectric properties and their statistical variability. The dielectric properties of 256 samples of random networks containing: 512, 2048, 8192 and 32 768 components distributed randomly in the ratios 60% R-40% C, 50% R-50% C and 40% R-60% C have been computed. It has been found that these properties exhibit the anomalous power law dependences on frequency known as the 'universal dielectric response' (UDR). Attention is drawn to the contrast between frequency ranges across which percolation determines dielectric response, where considerable variability is found amongst the samples, and those across which power laws define response where very little variability is found between samples. It is concluded that the power law UDRs are emergent pr...

  10. Two-point resistance of a resistor network embedded on a globe

    Science.gov (United States)

    Tan, Zhi-Zhong; Essam, J. W.; Wu, F. Y.

    2014-07-01

    We consider the problem of two-point resistance in an (m-1)×n resistor network embedded on a globe, a geometry topologically equivalent to an m ×n cobweb with its boundary collapsed into one single point. We deduce a concise formula for the resistance between any two nodes on the globe using a method of direct summation pioneered by one of us [Z.-Z. Tan, L. Zhou, and J. H. Yang, J. Phys. A: Math. Theor. 46, 195202 (2013), 10.1088/1751-8113/46/19/195202]. This method is contrasted with the Laplacian matrix approach formulated also by one of us [F. Y. Wu, J. Phys. A: Math. Gen. 37, 6653 (2004), 10.1088/0305-4470/37/26/004], which is difficult to apply to the geometry of a globe. Our analysis gives the result in the form of a single summation.

  11. Calculating two-point resistances in distance-regular resistor networks

    International Nuclear Information System (INIS)

    An algorithm for the calculation of the resistance between two arbitrary nodes in an arbitrary distance-regular resistor network is provided, where the calculation is based on stratification introduced in Jafarizadeh and Salimi (2006 J. Phys. A: Math. Gen. 39 1-29) and the Stieltjes transform of the spectral distribution (Stieltjes function) associated with the network. It is shown that the resistances between a node ? and all nodes ? belonging to the same stratum with respect to the ? (R??(i), ? belonging to the ith stratum with respect to the ?) are the same. Also, the analytical formulae for two-point resistances R??(i), i=1,2,3, are given in terms of the size of the network and corresponding intersection numbers. In particular, the two-point resistances in a strongly regular network are given in terms of its parameters (v, ?, ?, ?). Moreover, the lower and upper bounds for two-point resistances in strongly regular networks are discussed

  12. Highly tunable local gate controlled complementary graphene device performing as inverter and voltage controlled resistor

    International Nuclear Information System (INIS)

    Using single-layer CVD graphene, a complementary field effect transistor (FET) device is fabricated on the top of separated back-gates. The local back-gate control of the transistors, which operate with low bias at room temperature, enables highly tunable device characteristics due to separate control over electrostatic doping of the channels. Local back-gating allows control of the doping level independently of the supply voltage, which enables device operation with very low VDD. Controllable characteristics also allow the compensation of variation in the unintentional doping typically observed in CVD graphene. Moreover, both pn and np configurations of FETs can be achieved by electrostatic doping using the local back-gate. Therefore, the device operation can also be switched from inverter to voltage controlled resistor, opening new possibilities in using graphene in logic circuitry. (paper)

  13. METHOD OF DETERMINING THE START TIME OF INDUCTION MOTORS IN THE CONTROL OF RESISTOR-THYRISTOR MODULES

    Directory of Open Access Journals (Sweden)

    V.I. Lobov

    2015-08-01

    Full Text Available Purpose. An electric general-purpose drive with asynchronous motor is proposed. For motor control in stator and rotor, circuits used resistors and thyristors. These elements included together in various ways. This allows to get a variety of power converter circuit with resistor-thyristor modules. Methodology. Taking into account the technical requirements for industrial machinery developed an analytical method for determining the run-up controlled induction motor. Formed starting modes by changing the value of the equivalent resistor-thyristor modules. Using logic synthesis and function of thyristors switching to determine the equivalent value of resistor-thyristor modules. Scientific novelty. It lies in the fact that the proposed method of calculation to determine the run-up in the limited amount of transient current and torque of the motor. The total moment of inertia and the static moment of the drive do not have a significant impact on the maximum value of the transient electromagnetic torque. Most of these options affect the transition process, the oscillation frequency of the electromagnetic torque and the motor speed. Practical value. The method used for calculating allows to select the simplest laws of launch control actuator and apply open-loop control system without increasing the cost of the power converter, so it is of practical importance.

  14. Design note of a 10,000 amp 2 MJoules dump resistor for the magnet test facility

    International Nuclear Information System (INIS)

    This report contains the design notes of a 2 MJoules 10,000A, 1000V, dump resistor, with taps from 25 mOhms to 300 mOhms maximum. The resistor is forced air-cooled and can handle continuously one 2 MJ dump every 5 minutes at all taps. The resistor is made from 304 stainless steel bars and is mounted in a 90 in.H x 24 in.W x 20 in.D steel enclosure, with easy access to taps. The upper resistance sections are made lighter to save material cost and weight. The total weight of the resistance element is 427 lbs. The resistor is used to absorb the stored energy from cryogenic magnets during tests at the magnet test facility. Interlocks are provided for remote tap readout, dc over current and over temperature. A build-in current sensor and timing relay switch forced air-cooling on for 5 minutes, after a dump. 12 figs., 3 tabs

  15. Technical-economic evaluation of the utilization of closing resistor in CEMIG extra-high voltage circuit breakers

    Energy Technology Data Exchange (ETDEWEB)

    Rocha, Angelica C.O.; Pinto, Roberto del Giudice R.; Teixeira, Jose Cleber; Fonseca, Rodrigo Assuncao; F. Junior, Sebastiao V. [Companhia Energetica de Minas Gerais (CEMIG), Belo Horizonte, MG (Brazil)

    1994-12-31

    This paper presents the technical and economic studies performed by CEMIG, Companhia Energetica de Minas Gerais, Brazil, concerning the use of closing resistor in its extra-high voltage (EHV) breakers. The analysis emphasizes the advantages which could be achieved with the elimination of the resistor as far as costs and reliability are concerned. This evaluation was motivated by two 500 kV breaker failures resulting from the breakdown of the closing resistor operation mechanism. These occurrences resulted in operative restriction for CEMIG EHV system. The analysis demanded a review of the capability criteria of silicon carbide (Si C) gap arresters, which are still greatly used in CEMIG EHV System, and of the procedures to be applied when carrying out the transient studies. The investigation resulted in the prompt removal of closing resistors from circuit breakers in CEMIG extra-high voltage system generating an economy of approximately U$ 840,00 and an improvement in safety and system reliability. (author) 13 refs., 4 figs., 1 tab.

  16. Radial/axial power divider/combiner

    Science.gov (United States)

    Vaddiparty, Yerriah P. (Inventor)

    1987-01-01

    An electromagnetic power divider/combiner comprises N radial outputs (31) having equal powers and preferably equal phases, and a single axial output (20). A divider structure (1) and a preferably identical combiner structure (2) are broadside coupled across a dielectric substrate (30) containing on one side the network of N radial outputs (31) and on its other side a set of N equispaced stubs (42) which are capacitively coupled through the dielectric substrate (30) to the N radial outputs (31). The divider structure (1) and the combiner structure (2) each comprise a dielectric disk (12, 22, respectively) on which is mounted a set of N radial impedance transformers (14, 24, respectively). Gross axial coupling is determined by the thickness of the dielectric layer (30). Rotating the disks (12, 22) with respect to each other effectuates fine adjustment in the degree of axial coupling.

  17. Wideband unbalanced waveguide power dividers and combiners

    Energy Technology Data Exchange (ETDEWEB)

    Halligan, Matthew; McDonald, Jacob Jeremiah; Strassner, II, Bernd H.

    2016-05-17

    The various technologies presented herein relate to waveguide dividers and waveguide combiners for application in radar systems, wireless communications, etc. Waveguide dividers-combiners can be manufactured in accordance with custom dimensions, as well as in accordance with waveguide standards such that the input and output ports are of a defined dimension and have a common impedance. Various embodiments are presented which can incorporate one or more septum(s), one or more pairs of septums, an iris, an input matching region, a notch located on the input waveguide arm, waveguide arms having stepped transformer regions, etc. The various divider configurations presented herein can be utilized in high fractional bandwidth applications, e.g., a fractional bandwidth of about 30%, and RF applications in the Ka frequency band (e.g., 26.5-40 GHz).

  18. Modeling phase noise in frequency dividers.

    Science.gov (United States)

    Egan, W F

    1990-01-01

    A theory for modeling noise in frequency dividers and the measurements to support the theory are presented. The most complete measurements were made on ECL (emitter-coupled logic) dividers for which the primary noise contributions were from additive output noise and sampled additive input noise. Output phase power spectral density due to the latter varies as the square of the input frequency and is inversely proportion to the output frequency. The third most significant contributor was sampled output noise. A summary of available noise data is also given. PMID:18285046

  19. Divide-and-Conquer Matrix Factorization

    CERN Document Server

    Mackey, Lester; Jordan, Michael I

    2011-01-01

    This work introduces SubMF, a parallel divide-and-conquer framework for noisy matrix factorization. SubMF divides a large-scale matrix factorization task into smaller subproblems, solves each subproblem in parallel using an arbitrary base matrix factorization algorithm, and combines the subproblem solutions using techniques from randomized matrix approximation. Our experiments with collaborative filtering, video background modeling, and simulated data demonstrate the near-linear to super-linear speed-ups attainable with this approach. Moreover, our analysis shows that SubMF enjoys high probability recovery guarantees comparable to those of its base algorithm.

  20. Symbols and the Divided Self in Janus

    Directory of Open Access Journals (Sweden)

    Xiaomi ZHANG

    2014-03-01

    Full Text Available The paper presents the main theme of American writer Ann Beattie’s short novel Janus—the divided self. Illustrations are given here on the symbolic meaning of the mysterious bowl as well as the cold house. The relationship between bowl and love as well as connection between house and marriage reveal the true implication of two-faced god Janus. All the work throws light on the divided self resulted from emptiness, confusion and emotional difficulties of middle and upper-middle class.

  1. Conquering the digital divide: Botswana and South Korea digital divide status and interventions

    Directory of Open Access Journals (Sweden)

    Nonofo C. Sedimo

    2011-03-01

    Full Text Available Background: Botswana is putting in place initiatives towards establishing itself as a knowledgebased economy. Transformation from a resource-based to a knowledge-based economy is partly hinged on innovation, research and development capability, knowledge channels, and the funding of research and development activities.Objectives: Bridging the digital divide and narrowing the intra-national divide brings about global information and communication technology (ICT usage that translates into changing work patterns and eventually transformed economies. This article outlines the different interventions implemented in Botswana to bridge the divide. The South Korean experience in bridging the divide is discussed so as to serve as lessons on how to effectively bridge the divide to Botswanas initiatives.Method: Using a mix of exploratory and empirical study, this article presents the findings on the status of ICT uptake in Botswana and investigates the level of the digital divide in the country.Results: The results of the study show that the digital divide is much more evident in Botswana than in South Korea. South Korea has put in place robust strategic initiatives towards reducing the digital divide and this has largely transcended into its transformation into a full-fledged knowledge society.Conclusion: This article is timely as it unearths the different pointers that may be utilised in policy formation and what interventions need to be taken at both the individual and national level to bridge the digital divide.

  2. Bridging the Digital Divide in Higher Education.

    Science.gov (United States)

    Treviranus, Jutta; Coombs, Norman

    The emergence of the digital campus, and the rapid convergence of previously disparate methods of communicating information, presents both a risk and an opportunity for people with disabilities. The imminent risk is that non-inclusive design of the digital campus will irreparably widen the digital divide within higher education, to the detriment…

  3. Circular-Waveguide Power Combiner/Divider

    Science.gov (United States)

    Dunn, Vernon

    1988-01-01

    Power combiner/divider devised in which output from several solid-state modules combined directly into TE01 mode of circular waveguide. Results in low-loss, wide band device: because axisymmetry of TE01 mode, no essential limit on N. Latter feature is advantage in design of wide band, high-power, solid-state amplifiers operating at millimeter wavelengths.

  4. Project DIVIDE Instrument Development. Technical Report # 0810

    Science.gov (United States)

    Ketterlin-Geller, Leanne; Jung, Eunju; Geller, Josh; Yovanoff, Paul

    2008-01-01

    In this technical report, we describe the development of cognitive diagnostic test items that form the basis of the diagnostic system for Project DIVIDE (Dynamic Instruction Via Individually Designed Environments). The construct underlying the diagnostic test is division of fractions. We include a description of the process we used to identify the

  5. Jitter and phase noise in frequency dividers

    Czech Academy of Sciences Publication Activity Database

    Kroupa, Věnceslav František

    2001-01-01

    Roč. 50, č. 5 (2001), s. 1241-1243. ISSN 0018-9456 R&D Projects: GA ČR GA102/00/0958 Institutional research plan: CEZ:AV0Z2067918 Keywords : signal processing * frequency dividers * frequency synthesizers * phase locked loops Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 0.900, year: 2001

  6. Divide and Multiply: Baptist Diversity in Appalachia.

    Science.gov (United States)

    Dorgan, Howard

    1996-01-01

    Baptists' propensity for splitting apart arises from the faith's avowed love of theological argument. Gives an overview of Baptist denominations, and identifies the main issues that divide them: atonement, predestination, the nature and origins of good and evil, worship practices, church governance, gender issues, and other social and cultural…

  7. The Legacy of the Digital Divide

    Science.gov (United States)

    Ching, Cynthia; Basham, James; Jang, Eunice

    2005-01-01

    This study investigates how college students' current levels of technology use might be affected by digital divide issues. Survey data were collected from 130 students in colleges of education at two midwestern universities. Factor analysis yielded that students' uses of technology can be described using three broad categories: entertainment,

  8. From Digital Divide to Digital Democracy.

    Science.gov (United States)

    de los Santos, Gerardo E., Ed.; de los Santos, Alfredo G., Jr., Ed.; Milliron, Mark David, Ed.

    This publication is one of many efforts of the League for Innovation in the Community College to address the issue of societal technology access and learning needs. This work addresses the issue of the digital divide, which includes the often conflicting perspectives of information technology (IT) access and literacy needs held by government

  9. Young People's Internet Use: Divided or Diversified?

    Science.gov (United States)

    Boonaert, Tom; Vettenburg, Nicole

    2011-01-01

    This article critically analyses research on young people's internet use. Based on a literature analysis, it examines which young people do what on the internet. These results invite a reflection on the dominant discourse on the digital divide. Within this discourse, there is a strong focus on the use of the internet for information purposes only,

  10. Bridging the digital divide with mobile services

    CERN Document Server

    Yelton, Andromeda

    2013-01-01

    In this issue of Library Technology Reports, Andromeda Yelton shows how libraries can build on the breadth of this population to help bridge the digital divide and provide even greater access to information. Yelton breaks down the demographics of mobile internet users, provides examples of how different libraries are reaching out to these populations, and suggests what the future may hold for this trend.

  11. Capacitive divider for output voltage measurement of intense electron beam accelerator

    International Nuclear Information System (INIS)

    A kind of simple-mechanism, easy-disassembly self-integrating capacitive divider used for measuring diode output voltage of intense electron beam accelerator (IEBA) is developed. The structure of the capacitive divider is described, and the capacitance value of the capacitive divider is calculated by theoretical analysis and electromagnetic simulation. The dependence of measurement voltage on electrical parameters such as stray capacitance, earth capacitance of front resistance is obtained by PSpice simulation. Measured waveforms appear overshoot phenomenon when stray capacitance of front resistance is larger, and the wavefront will be affected when earth capacitance of front resistance is larger. The diode output voltage waveforms of intense electron beam accelerator, are measured by capacitive divider and calibrated by water resistance divider, which is accordance with that measured by a resistive divider, the division ratio is about 563007. The designed capacitive divider can be used to measure high-voltage pulse with 100 ns full width at half maximum. (authors)

  12. The Digital Divide: A Global View

    Science.gov (United States)

    Ntoko, Alexander

    2011-04-01

    Huge progress was made in bridging the digital divide in first decade of 21^st century. This was largely due to the explosive growth of mobile, which saw numbers rise from under 500 million to over five billion mobile cellular subscriptions in just ten years. With household mobile penetration rates of over 50% even in rural areas of developing countries, we have achieved the dream of bringing all the world's people within reach of communications technology. We must now, however, replicate the mobile miracle for the Internet, and especially broadband, if we are to avoid creating a new broadband breach to replace the digital divide. Three things need to happen for this to be achieved: firstly, broadband needs to be brought to the top of the development agenda; secondly, broadband needs to become much more affordable and thirdly, security needs to be part of the strategy.

  13. New mechanism to cross the phantom divide

    Science.gov (United States)

    Du, Yunshuang; Zhang, Hongsheng; Li, Xin-Zhou

    2011-06-01

    Recently, type Ia supernova data appear to support a dark energy whose equation of state w crosses -1, which is a much more amazing problem than the acceleration of the universe. We show that it is possible for the equation of state to cross the phantom divide by a scalar field in gravity with an additional inverse power-law term of the Ricci scalar in the Lagrangian. The necessary and sufficient condition for a universe in which the dark energy can cross the phantom divide is obtained. Some analytical solutions with w-1 are obtained. A minimally coupled scalar with different potentials, including quadratic, cubic, quantic, exponential and logarithmic potentials are investigated via numerical methods, respectively. All these potentials lead to the crossing behavior. We show that it is a robust result which is hardly dependent on the concrete form of the potential of the scalar.

  14. New mechanism to cross the phantom divide

    International Nuclear Information System (INIS)

    Recently, type Ia supernova data appear to support a dark energy whose equation of state w crosses -1, which is a much more amazing problem than the acceleration of the universe. We show that it is possible for the equation of state to cross the phantom divide by a scalar field in gravity with an additional inverse power-law term of the Ricci scalar in the Lagrangian. The necessary and sufficient condition for a universe in which the dark energy can cross the phantom divide is obtained. Some analytical solutions with w-1 are obtained. A minimally coupled scalar with different potentials, including quadratic, cubic, quantic, exponential and logarithmic potentials are investigated via numerical methods, respectively. All these potentials lead to the crossing behavior. We show that it is a robust result which is hardly dependent on the concrete form of the potential of the scalar. (orig.)

  15. New mechanism to cross the phantom divide

    Energy Technology Data Exchange (ETDEWEB)

    Du, Yunshuang; Zhang, Hongsheng; Li, Xin-Zhou [Shanghai Normal University, Shanghai United Center for Astrophysics (SUCA), Shanghai (China)

    2011-06-15

    Recently, type Ia supernova data appear to support a dark energy whose equation of state w crosses -1, which is a much more amazing problem than the acceleration of the universe. We show that it is possible for the equation of state to cross the phantom divide by a scalar field in gravity with an additional inverse power-law term of the Ricci scalar in the Lagrangian. The necessary and sufficient condition for a universe in which the dark energy can cross the phantom divide is obtained. Some analytical solutions with w<-1 or w>-1 are obtained. A minimally coupled scalar with different potentials, including quadratic, cubic, quantic, exponential and logarithmic potentials are investigated via numerical methods, respectively. All these potentials lead to the crossing behavior. We show that it is a robust result which is hardly dependent on the concrete form of the potential of the scalar. (orig.)

  16. REGENERATIVE GAS TURBINES WITH DIVIDED EXPANSION

    DEFF Research Database (Denmark)

    Elmegaard, Brian; Qvale, Einar Bjørn

    2004-01-01

    their efficiency are always of interest. Recently, two independent studies have proposed recuperated gas turbines to be configured with the turbine expansion divided, in order to obtain higher efficiency. The idea is to operate the system with a gas generator and a power turbine, and use the gas from...... the gas generator part for recuperation ahead of the expansion in the power turbine. The present study is more complete than the predecessors in that the ranges of the parameters have been extended and the mathematical model is more realistic using an extensive simulation program. It is confirmed that...... the proposed divided expansion can be advantageous under certain circumstances. But, in order for todays micro gas turbines to be competitive, the thermodynamic efficiencies will have to be rather high. This requires that all component efficiencies including the recuperator effectiveness will have to...

  17. Analyzing Broadband Divide in the Farming Sector

    DEFF Research Database (Denmark)

    Jensen, Michael; Gutierrez Lopez, Jose Manuel; Pedersen, Jens Myrup

    Agriculture industry has been evolving for centuries. Currently, the technological development of Internet oriented farming tools allows to increase the productivity and efficiency of this sector. Many of the already available tools and applications require high bandwidth in both directions......, upstream and downstream connection. The main constraint is that farms are naturally located in rural areas where the required access broadband data rates are not available. This paper studies the broadband divide in relation to the Danish agricultural sector. Results show how there is an important...... difference between the broadband availability for farms and the rest of the households/buildings the country. This divide may be slowing down the potential technological development of the farming industry, in order to keep their competitiveness in the market. Therefore, broadband development in rural areas...

  18. Low phase noise digital frequency divider

    Science.gov (United States)

    Lutes, G. F., Jr. (Inventor)

    1973-01-01

    A low phase noise frequency divider composed of a grating arrangement is disclosed. The grating arrangement supplies selected portions of an input reference signal to be divided to a tuned circuit without any phase noise due to the grating action. The arrangement which in one embodiment consists of an FET is connected to the tuned circuit input to short out the input except when the input reference signal amplitude crosses ground level in a positive direction and a gate enabling signal is present at the gate electrode of the FET. The gate enabling signal alone does not decouple the tuned circuit input from ground, therefore phase noise, due to the leading and trailing edges of each gate-enabling signal, is substantially eliminated.

  19. Max Weber and Digital Divide Studies: Introduction

    OpenAIRE

    Ragnedda, Massimo; Muschert, Glenn

    2015-01-01

    Seminal sociologist Max Weber rarely wrote about media dynamics; however, the Weberian perspective offers rich potential for the analysis of various media issues, including the study of digital divides. In particular, the contribution of a Weberian school of thought to the field seems to be the addition of noneconomic and nontechnical concerns to the study of digital inequalities, most notably the importance of status and legitimacy and group affiliations and political relations as areas of f...

  20. Analyzing Broadband Divide in the Farming Sector

    OpenAIRE

    Jensen, Michael; Gutierrez Lopez, Jose Manuel; Pedersen, Jens Myrup

    2013-01-01

    Agriculture industry has been evolving for centuries.Currently, the technological development of Internetoriented farming tools allows to increase the productivity andefficiency of this sector. Many of the already available toolsand applications require high bandwidth in both directions,upstream and downstream connection. The main constraintis that farms are naturally located in rural areas where therequired access broadband data rates are not available. Thispaper studies the broadband divide...

  1. Crossing the phantom divide without phantom matter

    OpenAIRE

    Chimento, L.; Lazkoz, R.; Maartens, Roy; Quiros, I.

    2006-01-01

    A class of braneworld models can lead to phantom-like acceleration of the late universe, but without the need for any phantom matter. In the simplest models, the universe contains only cold dark matter and a cosmological constant. We generalize these models by introducing a quintessence field. The new feature in our models is that quintessence leads to a crossing of the phantom divide, $w=-1$. This is a purely gravitational effect, and there is no phantom instability. Furthermore, the Hubble ...

  2. Power divider of the MP 10

    International Nuclear Information System (INIS)

    The operation of the MP 10 power divider and resistances (600 megaohms, metal oxide resistances, in the column and in the tube of the MP 10), are investigated. The whole system is used in Vivitron accelerator (Strasbourg, France). The aim of the study is a better understanding of the machine's electrical operation. The resistances are tested under sulphur hexafluoride pressure and under high voltage. The results allowed the characterization of those resistances for use under operating conditions

  3. Integral resistors and capacitors for mixed-signal packages using electroless plating and polymer-ceramic nanocomposites

    Science.gov (United States)

    Chahal, Premjeet

    In this work, new approaches to achieving integral resistors and capacitors on large area substrates at low temperatures in a high density wiring (HDW) environment using non-vacuum deposition techniques are introduced. This includes the use of polymer-ceramic nanocomposites for integral capacitors and electroless plating for integral resistors. From the literature review it is believed that resistors in the range of 5--50 ohm/square and capacitors in the range of 1--20 nF/cm2 can satisfy most of the mixed-signal application needs. The proposed materials can satisfy this need as demonstrated in this work. Several test vehicles were fabricated and measured to characterize the material properties, and demonstrate conventional and novel circuits for mixed-signal applications. To begin with, several polymer-ceramic combinations were analyzed under varying conditions to gain a fundamental understanding of the material system. Experimental advances have been made to achieve high dielectric constant values for both epoxy-ceramic and polyimide-ceramic systems. These material systems in general can satisfy specific capacitances in the range of 1--22 nF/cm2. These materials were found to be stable into the GHz range and have low loss-tangent. For electroless resistors, several plating baths were studied and a combination of Ni-P/Ni-W-P was found to produce the best results. Uniform plating was achieved through better nucleation of PdCl2 catalyst through the use of organosilane surface treatment. The Ni-P/Ni-W-P films produced sheet resistance in the range of 5--50 ohm/square and TCR below 50 ppm/C. The material is stable into the GHz range. Upon optimizing the electrical properties and processing of capacitors and resistors, several test vehicles were fabricated to demonstrate some conventional and novel passive structures for RF and mixed-signal applications (e.g., filters, delay lines, etc.). Some of the structures were modeled using MDS and PSPICE and a good correlation between measured and modeled results were obtained. Capacitors on large area PWB substrates using meniscus coating are also demonstrated with a typical capacitance of 10 nF/cm2. The yield of the capacitor structures is found to be affected by the surface roughness of the bottom copper electrode. Resistors have been demonstrated on 6? x 6? substrates using a simple set-up.

  4. Self-organization of divided hierarchy

    Science.gov (United States)

    Odagaki, Takashi; Kitada, Keigo; Omizo, Kenta; Fujie, Ryo

    2015-03-01

    There are two types of extreme form of hierarchy, one is the plutonomy where small fraction of winners and losers and many people in the middle class appear and the other a divided hierarchy where half of population become winners and the remaining half become losers. We study the emergence of the divided hierarchy in a model society which consists of bellicose individuals who always try to fight and fight with the strongest neighbor and pacific individuals who always try not to fight and when necessary fight with the weakest neighbor. In our model society, (1) individuals make random walk on a square lattice, (2) when two individuals encounter they fight each other and (3) the winner deprives wealth from the loser. By a Monte Carlo simulation, we show that there are two transitions when the population density is increased; one is a transition from the egalitarian society to a hierarchical society I where winners, losers and middle classes coexist and the other is a transition from the hierarchical society I to a hierarchical society II where winners and losers exist but no middle classes exist, that is the divided hierarchy. We also show that clusters consisting mostly of bellicose individuals appear in the hierarchical society I.

  5. Accurate calibration of resistance ratios between 1 MΩ and 1 GΩ using series resistors

    Science.gov (United States)

    Yu, Kwang Min; Ihm, G.

    2011-11-01

    As shown in high-resistance key comparisons carried out by the Consultative Committee for Electricity and Magnetism (CCEM), Inter-American Metrology System (SIM) and European Association of National Metrology Institutes (EURAMET), the accuracy of 10 MΩ and 1 GΩ resistances depends on ratio values between the reference resistance and unknown resistance and the accuracy of the reference resistance, which is determined with a quantized Hall resistance standard. This paper presents a method for calibrating 10:1 ratios in a high-resistance bridge using series resistors simply and accurately. By applying the 10:1 ratio errors determined using the presented method, the combined relative standard uncertainty for 1 GΩ resistance measurements using a modified Wheatstone bridge was estimated to be on the 1 × 10-6 level. The method was also applied to 1 GΩ resistance measurements using a direct-current comparator resistance bridge. It was found that the 1 GΩ resistances determined by the two bridges agreed within 2.4 × 10-6 Ω/Ω. We expect that the presented method can also be used to calibrate arbitrary resistance ratios.

  6. Combined TiN- and TaN temperature compensated thin film resistors

    Energy Technology Data Exchange (ETDEWEB)

    Malmros, Anna, E-mail: anna.malmros@chalmers.se; Andersson, Kristoffer; Rorsman, Niklas

    2012-01-01

    The opposite signs of the temperature coefficient of resistance (TCR) of two thin film materials, titanium nitride (TiN) and tantalum nitride (TaN), were used to form temperature compensated thin film resistors (TFRs). The principle of designing temperature compensated TFRs by connecting TFRs of each compound in series or in parallel was demonstrated. TiN, TaN, and combined TiN and TaN TFRs for monolithic microwave integrated circuits (MMICs) were fabricated by reactive sputtering. DC characterization was performed over the temperature range of 30-200 Degree-Sign C. The TiN TFRs exhibited an increase in resistivity with temperature with TCRs of 540 and 750 ppm/ Degree-Sign C. The TaN TFR on the other hand exhibited a negative TCR of - 470 ppm/ Degree-Sign C. The shunted TFRs were fabricated by serial deposition of TiN and TaN to form a bilayer component. The TCRs of the series- and shunt configurations were experimentally reduced to - 60 and 100 ppm/ Degree-Sign C, respectively. The concept of temperature compensation was used to build a Wheatstone bridge with an application in on-chip temperature sensing.

  7. The 'emergent scaling' phenomenon and the dielectric properties of random resistor-capacitor networks

    International Nuclear Information System (INIS)

    An efficient algorithm, based on the Frank-Lobb reduction scheme, for calculating the equivalent dielectric properties of very large random resistor-capacitor (R-C) networks has been developed. It has been used to investigate the network size and composition dependence of dielectric properties and their statistical variability. The dielectric properties of 256 samples of random networks containing: 512, 2048, 8192 and 32 768 components distributed randomly in the ratios 60% R-40% C, 50% R-50% C and 40% R-60% C have been computed. It has been found that these properties exhibit the anomalous power law dependences on frequency known as the 'universal dielectric response' (UDR). Attention is drawn to the contrast between frequency ranges across which percolation determines dielectric response, where considerable variability is found amongst the samples, and those across which power laws define response where very little variability is found between samples. It is concluded that the power law UDRs are emergent properties of large random R-C networks

  8. A High-Swing OTA with wide Linearity for design of self-tunable linear resistor

    Directory of Open Access Journals (Sweden)

    Nikhil Raj

    2015-09-01

    Full Text Available Low power consumption, long battery life and portability are essential requirements of modern health monitoring products. Operational Trans-conductance Amplifier (OTA operating in sub threshold region is an basic building block for low power health monitoring products design. An modified design of OTA which incorporates better linearity and increased output impedance has been discussed in this paper. The proposed OTA uses High-swing improved-Wilson current mirror for low power and low-frequency applications. The achieved linearity is about ± 1.9 volt and unity gain bandwidth (UGB of 342.30 KHz at power supply of 0.9 volt which makes OTA to consume power in range of nanowatts. The proposed lowvoltage OTA implementation in design of self- tunable linear resistor has been presented in this paper. The circuit implementation has been done using standard 0.18 micron technology provided by TSMC on BSIM3v3 level-53 model parameter and verified results through use of ELDO Simulator.

  9. Noise Measurements Of Resistors With The Use Of Dual-Phase Virtual Lock-In Technique

    Directory of Open Access Journals (Sweden)

    Stadler Adam Witold

    2015-12-01

    Full Text Available Measurement of low-frequency noise properties of modern electronic components is a very demanding challenge due to the low magnitude of a noise signal and the limit of a dissipated power. In such a case, an ac technique with a lock-in amplifier or the use of a low-noise transformer as the first stage in the signal path are common approaches. A software dual-phase virtual lock-in (VLI technique has been developed and tested in low-frequency noise studies of electronic components. VLI means that phase-sensitive detection is processed by a software layer rather than by an expensive hardware lock-in amplifier. The VLI method has been tested in exploration of noise in polymer thick-film resistors. Analysis of the obtained noise spectra of voltage fluctuations confirmed that the 1/f noise caused by resistance fluctuations is the dominant one. The calculated value of the parameter describing the noise intensity of a resistive material, C = 1·10−21 m3, is consistent with that obtained with the use of a dc method. On the other hand, it has been observed that the spectra of (excitation independent resistance noise contain a 1/f component whose intensity depends on the excitation frequency. The phenomenon has been explained by means of noise suppression by impedances of the measurement circuit, giving an excellent agreement with the experimental data.

  10. Combined TiN- and TaN temperature compensated thin film resistors

    International Nuclear Information System (INIS)

    The opposite signs of the temperature coefficient of resistance (TCR) of two thin film materials, titanium nitride (TiN) and tantalum nitride (TaN), were used to form temperature compensated thin film resistors (TFRs). The principle of designing temperature compensated TFRs by connecting TFRs of each compound in series or in parallel was demonstrated. TiN, TaN, and combined TiN and TaN TFRs for monolithic microwave integrated circuits (MMICs) were fabricated by reactive sputtering. DC characterization was performed over the temperature range of 30200 C. The TiN TFRs exhibited an increase in resistivity with temperature with TCRs of 540 and 750 ppm/C. The TaN TFR on the other hand exhibited a negative TCR of ? 470 ppm/C. The shunted TFRs were fabricated by serial deposition of TiN and TaN to form a bilayer component. The TCRs of the series- and shunt configurations were experimentally reduced to ? 60 and 100 ppm/C, respectively. The concept of temperature compensation was used to build a Wheatstone bridge with an application in on-chip temperature sensing.

  11. Circular resistor networks for electrical impedance tomography with partial boundary measurements

    International Nuclear Information System (INIS)

    We introduce an algorithm for the numerical solution of electrical impedance tomography (EIT) in two dimensions, with partial boundary measurements. The algorithm is an extension of the one in Borcea et al (2008 Inverse Problems 24 035013 (31pp)) and Vasquez (2006 PhD Thesis Rice University, Houston, TX, USA) for EIT with full boundary measurements. It is based on resistor networks that arise in finite volume discretizations of the elliptic partial differential equation for the potential on so-called optimal grids that are computed as part of the problem. The grids are adaptively refined near the boundary, where we measure and expect better resolution of the images. They can be used very efficiently in inversion, by defining a reconstruction mapping that is an approximate inverse of the forward map, and acts therefore as a preconditioner in any iterative scheme that solves the inverse problem via optimization. The main result in this paper is the construction of optimal grids for EIT with partial measurements by extremal quasiconformal (Teichmüller) transformations of the optimal grids for EIT with full boundary measurements. We present the algorithm for computing the reconstruction mapping on such grids, and we illustrate its performance with numerical simulations. The results show an interesting trade-off between the resolution of the reconstruction in the domain of the solution and distortions due to artificial anisotropy induced by the distribution of the measurement points on the accessible boundary

  12. The SiPM with bulk quenching resistor: progress at NDL and applications in Raman spectroscopy

    International Nuclear Information System (INIS)

    The SiPMs with quenching resistors integrated into bulk epitaxial silicon have been investigated at the Novel Device Laboratory (NDL), Beijing Normal University, China. The aim is to alleviate the conflict between the high photon detection efficiency (PDE) and high APD cell density or dynamic range encountered by conventional SiPM so that this promising detector can be applied where both large dynamic range and high PDE are required simultaneously. We report herein the latest progresses on the SiPM with 104/mm2 micro-cell density and 0.5 mm0.5 mm, 1 mm1 mm as well as 20 ?m1.8 mm effective area, which have been designed and fabricated at NDL. Application of the strip SiPM with a gated photon counting technique on the measurement of TNT Raman spectroscopy is demonstrated, and the feasibility for extending SiPMs in conjunction with Nuclear Instrumentation Modules (NIM) based electronics to the field of ultra-weak spectroscopy is verified.

  13. The two-point resistance of a resistor network: a new formulation and application to the cobweb network

    International Nuclear Information System (INIS)

    We consider the problem of two-point resistance in a resistor network previously studied by one of us (Wu 2004 J. Phys. A: Math. Gen. 37 6653). By formulating the problem differently, we obtain a new expression for the two-point resistance between two arbitrary nodes which is simpler and can be easier to use in practice. We apply the new formulation to the cobweb resistor network to obtain the resistance between two nodes in the network. Particularly, our results prove a recently proposed conjecture on the resistance between the center node and a node on the network boundary. Our analysis also solves the spanning tree problem on the cobweb network. (paper)

  14. Microstructure and electrical properties of perovskite ruthenate-based lead-free thick film resistors on alumina and LTCC

    International Nuclear Information System (INIS)

    CaRuO3 perovskite based thick-film resistors were processed on 965 alumina and Low Temperature Co-fired Ceramics (LTCC) substrates. The microstructure evolution, possible interactions and electrical properties of resistors were investigated. TFR's with 25% by vol. of ruthenate on alumina exhibit a sheet resistance Rs = 5KΩ/sq. with hot and cold TCR of 225 and 470 ppm/oC respectively, whereas the same composition gives 1,2 KΩ/sq. and 1.65 KΩ/sq. for cold fired and post-fired samples, respectively, on LTCC, with hot and cold TCR of 190 and 314 ppm/oC for co-fired structures, and 216 and 205 ppm/oC respectively for post-fired LTCC structures. (author)

  15. On-wafer measurements and characterization of poly-si resistors for evaluation of selected CMOS manufacturing processes

    Science.gov (United States)

    Głuszko, Grzegorz; Tomaszewski, Daniel; Malesińska, Jolanta; Kucharski, Krzysztof

    2013-07-01

    In this study, measurements of resistance of polysilicon resistors with different widths have been done over the whole surface of the SOI wafers. The obtained results have been used to determine changes in their width, which is equivalent with shortening of the channel length in the photoli-thography process. By studying the elements distributed across the wafers it was possible to assess the homogeneity of the MOS transistor gate manufacturing process. the abstract two lines below author names and addresses.

  16. European IPTV and the digital divide

    OpenAIRE

    Mira Moshe

    2013-01-01

    By the end of 2011, 34.3m households took a pay IPTV subscription as their primary TV service. Estimates are that these figures will more than double over the next five years, reaching 76.5mn by the end of 2016. Revenues are expected to increase from 6.2bn U.S. dollars in 2011 to 11.9bn U.S. dollars in 2016. However, penetration will remain relatively low, with only 5% of the world’s TV households expected to subscribe to IPTV platforms by 2016. This study deals with the digital divide in Eur...

  17. Conquering the digital divide: Botswana and South Korea digital divide status and interventions

    OpenAIRE

    Nonofo C. Sedimo; Kelvin J. Bwalya; Tanya du Plessis

    2011-01-01

    Background: Botswana is putting in place initiatives towards establishing itself as a knowledgebased economy. Transformation from a resource-based to a knowledge-based economy is partly hinged on innovation, research and development capability, knowledge channels, and the funding of research and development activities.Objectives: Bridging the digital divide and narrowing the intra-national divide brings about global information and communication technology (ICT) usage that translates into cha...

  18. Effects of a parallel resistor on electrical characteristics of a piezoelectric transformer in open-circuit transient state.

    Science.gov (United States)

    Chang, Kuo-Tsai

    2007-01-01

    This paper investigates electrical transient characteristics of a Rosen-type piezoelectric transformer (PT), including maximum voltages, time constants, energy losses and average powers, and their improvements immediately after turning OFF. A parallel resistor connected to both input terminals of the PT is needed to improve the transient characteristics. An equivalent circuit for the PT is first given. Then, an open-circuit voltage, involving a direct current (DC) component and an alternating current (AC) component, and its related energy losses are derived from the equivalent circuit with initial conditions. Moreover, an AC power control system, including a DC-to-AC resonant inverter, a control switch and electronic instruments, is constructed to determine the electrical characteristics of the OFF transient state. Furthermore, the effects of the parallel resistor on the transient characteristics at different parallel resistances are measured. The advantages of adding the parallel resistor also are discussed. From the measured results, the DC time constant is greatly decreased from 9 to 0.04 ms by a 10 k(omega) parallel resistance under open output. PMID:17225805

  19. Development of high voltage surge limiting resistor for protection of HV multiplier of 3 MeV DC accelerator

    International Nuclear Information System (INIS)

    A 3MeV, 10mA DC electron beam accelerator is in commissioning stages at EBC, Kharghar, Navi Mumbai. The accelerating potential of -3MV is generated by a Parallel Coupled Voltage Multiplier (PCVM) scheme using 74 stages of HV rectifier stacks in the 6 kg/cm2 SF6 gas environment. The HV surges of order of 600kV, 42kA, 10ns is estimated across the rectifier stacks during sparking in the multiplier column. To limit the surge current and protect the rectifier diodes, a non inductive thick film surge limiting resistor (SLR) and protective spark gap is designed and developed. The rectifier stacks with surge limiting resistors at both the ends and protective spark gap in parallel has been successfully tested in simulated surge condition at an impulse voltage of 212kVp, 150ns FWHM and surge energy of 200J, 10ms, 20kV at 6kg/cm2 SF6 gas environment and found satisfactorily. Subsequently the HV multiplier was installed with this surge protection scheme and is being tested at 1.2 MeV level. This paper describes the design features and test results of the non-inductive surge limiting resistor. (author)

  20. An evaluation of a translator for finite element data to resistor/capacitor data for the heat diffusion equation

    International Nuclear Information System (INIS)

    This paper evaluates a translator for finite element data to resistor/capacitor data (FEM/RC) for the numerical solution of heat diffusion problems. The translator involves the derivation of thermal resistors and capacitors, implicit in the heat balance formulation of the finite difference method. It uses a finite element mesh, which consists of nodes and elements and is implicit in the Galerkin finite element method (GFEM). This hybrid translation method, FEM/RC, has been incorporated in Q/TRAN, a new thermal analysis computer code. This evaluation compares Q/TRAN, HEATING-6, and a research code employing GFEM on a purely mathematical, highly nonlinear steady-state conduction benchmark problem. The evaluation concludes that the FEM/RC technique has numerical characteristics that are consistent with comparable schemes for the benchmark problem. FEM/RC also accurately translates skewed meshes. Because FEM/RC generates resistors and capacitors, it appears to offer a more efficient method than the classical GFEM

  1. OVERVIEW TO THE ELDERLY AND AGEING WITHIN THE FRAMEWORK OF DIVIDING/BEING DIVIDED PHENOMENONS

    Directory of Open Access Journals (Sweden)

    Derya BAYRIMENGİLLİ

    2014-01-01

    Full Text Available Temporality is the source of a kind of anxiety which continues lifelong. As Kierkegaard expressed, the consciousness of temporality increases the rate of anxiety during spending years in a world carrying hopes. Anxiety may decrease in places where people understand each other. However, we see that in changing social, political and economic conditions “understanding” does not appear to be a structural characteristic or a condition of human existence; that, on the contrary, it takes shape as affirmation reduced to a simple, technical-material current of communication. The reason for this can be searched in the phenomenon of being divided and/or dividing. It attracts attentions that ageing people are forced to adapt to the lifes which is surrounded by activity of dividing. It may be asked with astonishment as to what kind of a relation can ageing have to being divided which is a mathematical or biological term; but when a short historical analysis is made concerning socio-economic changes, it can be observed that being divided influences the individual and her/his attitude towards ageing. In this paper, with a brief philosophical reading, answers shall be tried to be provided to fundamental questions as to what manner of being divided is experienced throughout the historical process, what the impact of such a division is on existence and how this process surrounds ageing people.

  2. Essential Cycles in Graph Divides as a Link Representation

    OpenAIRE

    KAWAMURA, Tomomi

    2006-01-01

    Graph divide links were introduced as an extension of the class of A'Campo's divide links. We show that some of such links cannot be represented as the links of any graph divides including less circles or less cycles.

  3. Features of the current-voltage characteristics of the resistors made by 'silicon with dielectric isolation' technology at high densities of leaking current

    International Nuclear Information System (INIS)

    Investigation of current-voltage characteristics of diffusion resistors, made by 'Silicon with dielectric isolation' technology with leaking current density till 105A/sm2 and different geometrical characteristics were conducted

  4. America's digital divide: 2000-2003 trends.

    Science.gov (United States)

    Whaley, Kermit C

    2004-04-01

    Computer ownership and literacy, along with Internet access and its many applications, has become, for many, a trademark for the Americans' lifestyle. Research shows that computer ownership and literacy, along with Internet access and expertise, is rapidly changing how Americans go about their business. The technological industry is providing many opportunities for Americans to operate in markets, global and local, not previously available. These changes are apparent across all U.S. sociocultural and geographic boundaries. Yet, upon close analysis, there are individuals and communities less connected with many completely excluded from participation. Those individuals exist below a line called the Digital Divide. Growth in computer ownership and Internet use, while offering optimism that the Digital Divide is narrowing, also illustrates that, without focused intervention will for certain populations, continue. Public and private programs, focus groups, and pocks of community activism, each hope to correct the disparities among on- and-off line Americans. On many fronts, there is evidence that progress is being made by many. Income, race, age, and geographic location are often the determining factors. PMID:15195849

  5. Media Literacy in Times of Media Divides

    Directory of Open Access Journals (Sweden)

    Kaja Žuran

    2013-12-01

    Full Text Available We live in a post-modern society, an information society, a society based around knowledge and participation, and above all in a media society. In a media culture where media holds a dominant position, we cannot overlook the emerging idea of a ‘media divide’ within the frame of media education, media literate individuals and the expansion of the traditional concept of media literacy. Firstly, we are in an era of technological revolution, and it is time to consider the meaning and function of media and how we experience it in our everyday life. Secondly, as a society we are subject to intense media invasion and we all need to learn how to use it to our benefit and apply a critical and autonomous perspective towards selecting media content. Otherwise the media divide between the media literate and illiterate will widen; but is there even a chance to overcome the supposed divide between those who are formally media educated and those who are not?

  6. European IPTV and the digital divide

    Directory of Open Access Journals (Sweden)

    Mira Moshe

    2013-07-01

    Full Text Available By the end of 2011, 34.3m households took a pay IPTV subscription as their primary TV service. Estimates are that these figures will more than double over the next five years, reaching 76.5mn by the end of 2016. Revenues are expected to increase from 6.2bn U.S. dollars in 2011 to 11.9bn U.S. dollars in 2016. However, penetration will remain relatively low, with only 5% of the world’s TV households expected to subscribe to IPTV platforms by 2016. This study deals with the digital divide in Europe in terms of a adopting service providers – IPTV inequality between regarding service providers; b households subscribers – IPTV inequality between regarding households subscribers; and c inequality between EU countries and other European countries with regard to consumer expenditures.

  7. Library outreach: addressing Utah's "Digital Divide".

    Science.gov (United States)

    McCloskey, K M

    2000-10-01

    A "Digital Divide" in information and technological literacy exists in Utah between small hospitals and clinics in rural areas and the larger health care institutions in the major urban area of the state. The goals of the outreach program of the Spencer S. Eccles Health Sciences Library at the University of Utah address solutions to this disparity in partnership with the National Network of Libraries of Medicine-- Midcontinental Region, the Utah Department of Health, and the Utah Area Health Education Centers. In a circuit-rider approach, an outreach librarian offers classes and demonstrations throughout the state that teach information-access skills to health professionals. Provision of traditional library services to unaffiliated health professionals is integrated into the library's daily workload as a component of the outreach program. The paper describes the history, methodology, administration, funding, impact, and results of the program. PMID:11055305

  8. Library outreach: addressing Utah's Digital Divide

    Science.gov (United States)

    McCloskey, Kathleen M.

    2000-01-01

    A Digital Divide in information and technological literacy exists in Utah between small hospitals and clinics in rural areas and the larger health care institutions in the major urban area of the state. The goals of the outreach program of the Spencer S. Eccles Health Sciences Library at the University of Utah address solutions to this disparity in partnership with the National Network of Libraries of MedicineMidcontinental Region, the Utah Department of Health, and the Utah Area Health Education Centers. In a circuit-rider approach, an outreach librarian offers classes and demonstrations throughout the state that teach information-access skills to health professionals. Provision of traditional library services to unaffiliated health professionals is integrated into the library's daily workload as a component of the outreach program. The paper describes the history, methodology, administration, funding, impact, and results of the program. PMID:11055305

  9. Vegetation baseline report : Connacher great divide project

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-08-01

    This baseline report supported an application by Connacher Oil and Gas Ltd. to the Alberta Energy and Utilities Board (EUB) and Alberta Environment (AENV) for the Great Divide Steam Assisted Gravity Drainage (SAGD) Project. The goal of the report was to document the distribution and occurrence of ecosite phases and wetland classes in the project footprint as well as to document the distribution of rare plants; rare plant communities: and intrusive species and old growth communities, including species of management concern. A methodology of the baseline report was presented, including details of mapping and field surveys. Six vegetation types in addition to the disturbed land unit were identified in the project footprint and associated buffer. It was noted that all vegetation types are common for the boreal forest natural regions. Several species of management concern were identified during the spring rare plant survey, including rare bryophytes and non-native or invasive species. Mitigation was identified through a slight shift of the footprint, transplant of appropriate bryophyte species and implementation of a weed management plan. It was noted that results of future surveys for rare plants will be submitted upon completion. It was concluded that the effects of the project on existing vegetation is expected to be low because of the small footprint, prior disturbance history, available mitigation measures and conservation and reclamation planning. 27 refs., 5 tabs., 4 figs.

  10. Quantitative Measurement of the Digital Divide

    Science.gov (United States)

    Cottrell, Roger

    2007-04-01

    Bandwidth and the Internet infrastructure are the life-blood of the world's knowledge economy, but they are often scarcest where most needed. Measuring the numbers of users of the Internet infrastructure is not easy in developing countries because many people share accounts, use corporate and academic networks, or visit the rapidly growing number of cyber cafes, telecentres and business services. Also measuring the number of users does not take into account the level of use. One valuable indicator for measuring the Internet infrastructure is the international Internet performance of a country or region. One of the major aims of the PingER project is to provide an historical archive of extensive, publicly accessible, up-to-date, measurements, analyses and reports of multiple Internet performance indicators (such as delay, loss, throughput, reachability, and jitter) between sites, countries and regions of the world. This talk will briefly describe the PingER project and then compare and contrast the Internet performance and its trends within and between countries and regions of the world. By means of extensive case studies it will also identify which regions need the greatest attention, together with their major issues and possible approaches to reducing the divide.

  11. Implementation of cost-effective diffuse light source mechanism to reduce specular reflection and halo effects for resistor-image processing

    Science.gov (United States)

    Chen, Yung-Sheng; Wang, Jeng-Yau

    2015-09-01

    Light source plays a significant role to acquire a qualified image from objects for facilitating the image processing and pattern recognition. For objects possessing specular surface, the phenomena of reflection and halo appearing in the acquired image will increase the difficulty of information processing. Such a situation may be improved by the assistance of valuable diffuse light source. Consider reading resistor via computer vision, due to the resistor's specular reflective surface it will face with a severe non-uniform luminous intensity on image yielding a higher error rate in recognition without a well-controlled light source. A measurement system including mainly a digital microscope embedded in a replaceable diffuse cover, a ring-type LED embedded onto a small pad carrying a resistor for evaluation, and Arduino microcontrollers connected with PC, is presented in this paper. Several replaceable cost-effective diffuse covers made by paper bowl, cup and box inside pasted with white paper are presented for reducing specular reflection and halo effects and compared with a commercial diffuse some. The ring-type LED can be flexibly configured to be a full or partial lighting based on the application. For each self-made diffuse cover, a set of resistors with 4 or 5 color bands are captured via digital microscope for experiments. The signal-to-noise ratio from the segmented resistor-image is used for performance evaluation. The detected principal axis of resistor body is used for the partial LED configuration to further improve the lighting condition. Experimental results confirm that the proposed mechanism can not only evaluate the cost-effective diffuse light source but also be extended as an automatic recognition system for resistor reading.

  12. Calculating electronic tunnel currents in networks of disordered irregularly shaped nanoparticles by mapping networks to arrays of parallel nonlinear resistors

    Energy Technology Data Exchange (ETDEWEB)

    Aghili Yajadda, Mir Massoud [CSIRO Manufacturing Flagship, P.O. Box 218, Lindfield NSW 2070 (Australia)

    2014-10-21

    We have shown both theoretically and experimentally that tunnel currents in networks of disordered irregularly shaped nanoparticles (NPs) can be calculated by considering the networks as arrays of parallel nonlinear resistors. Each resistor is described by a one-dimensional or a two-dimensional array of equal size nanoparticles that the tunnel junction gaps between nanoparticles in each resistor is assumed to be equal. The number of tunnel junctions between two contact electrodes and the tunnel junction gaps between nanoparticles are found to be functions of Coulomb blockade energies. In addition, the tunnel barriers between nanoparticles were considered to be tilted at high voltages. Furthermore, the role of thermal expansion coefficient of the tunnel junction gaps on the tunnel current is taken into account. The model calculations fit very well to the experimental data of a network of disordered gold nanoparticles, a forest of multi-wall carbon nanotubes, and a network of few-layer graphene nanoplates over a wide temperature range (5-300 K) at low and high DC bias voltages (0.001 mV50 V). Our investigations indicate, although electron cotunneling in networks of disordered irregularly shaped NPs may occur, non-Arrhenius behavior at low temperatures cannot be described by the cotunneling model due to size distribution in the networks and irregular shape of nanoparticles. Non-Arrhenius behavior of the samples at zero bias voltage limit was attributed to the disorder in the samples. Unlike the electron cotunneling model, we found that the crossover from Arrhenius to non-Arrhenius behavior occurs at two temperatures, one at a high temperature and the other at a low temperature.

  13. Comparison of three resistor network division circuits for the readout of 4×4 pixel SiPM arrays

    International Nuclear Information System (INIS)

    The purpose of this study is to investigate the behavior of a flexible SensL's silicon photomultiplier array (SPMArray4) photodetector for possible applications in PET imaging. We have designed and evaluated three different resistor network division circuits to read out the signal outputs of a 4×4 pixel SiPM array. We have applied firstly (i) a symmetric resistive voltage division circuit, secondly (ii) a symmetric resistive charge division circuit and thirdly (iii) a charge division multiplexing resistor network reducing the 16 pixel outputs to 4 position signals. In the first circuit the SensL SPMArray4-A0 preamplification electronics and a SPMArray4-A1 evaluation board providing the 16 pixels voltage outputs were used, before the symmetric resistive voltage network. We reduced the 16 voltage signals firstly to 4X and 4Y coordinate signals. Then those signals were further reduced to 2X and 2Y position signals connected via a resistor network. In the second readout circuit we have used the same technique but without the preamplification stage. The third circuit is based on a discretized positioning circuit, which multiplexes the 16 signals from the SiPM array to 4 position signals. The 4 position signals (Xa, Xb, Yc and Yd) were digitized using a free running sampling technique. An FPGA (Spartan 6 LX16) was used for triggering and signal processing of the pulses. We acquired raw images and energy histograms of a BGO and a CsI:Na pixilated scintillator under 22Na excitation. A clear visualization of the discrete 2×2×5 mm3 pixilated BGO scintillator elements as well as the 1×1×5 mm3 pixilated CsI:Na crystal array was achieved with all applied readout circuits. The symmetric resistive charge division circuit provides higher peak to valley ratio than the other readout circuits. Τhe sensitivity and the energy resolution remained almost constant for the three circuits

  14. Calculating electronic tunnel currents in networks of disordered irregularly shaped nanoparticles by mapping networks to arrays of parallel nonlinear resistors

    International Nuclear Information System (INIS)

    We have shown both theoretically and experimentally that tunnel currents in networks of disordered irregularly shaped nanoparticles (NPs) can be calculated by considering the networks as arrays of parallel nonlinear resistors. Each resistor is described by a one-dimensional or a two-dimensional array of equal size nanoparticles that the tunnel junction gaps between nanoparticles in each resistor is assumed to be equal. The number of tunnel junctions between two contact electrodes and the tunnel junction gaps between nanoparticles are found to be functions of Coulomb blockade energies. In addition, the tunnel barriers between nanoparticles were considered to be tilted at high voltages. Furthermore, the role of thermal expansion coefficient of the tunnel junction gaps on the tunnel current is taken into account. The model calculations fit very well to the experimental data of a network of disordered gold nanoparticles, a forest of multi-wall carbon nanotubes, and a network of few-layer graphene nanoplates over a wide temperature range (5-300 K) at low and high DC bias voltages (0.001 mV–50 V). Our investigations indicate, although electron cotunneling in networks of disordered irregularly shaped NPs may occur, non-Arrhenius behavior at low temperatures cannot be described by the cotunneling model due to size distribution in the networks and irregular shape of nanoparticles. Non-Arrhenius behavior of the samples at zero bias voltage limit was attributed to the disorder in the samples. Unlike the electron cotunneling model, we found that the crossover from Arrhenius to non-Arrhenius behavior occurs at two temperatures, one at a high temperature and the other at a low temperature.

  15. Development and characterisation of silicon photomultipliers with bulk-integrated quench resistors for future applications in particle and astroparticle physics

    International Nuclear Information System (INIS)

    This thesis deals with the development and characterisation of a novel silicon photomultiplier concept with bulk-integrated quench resistors. The approach allows the realisation of a free entrance window and high fill factors, which leads to an improvement of the detection efficiency. With first prototype productions a proof of concept was possible. A full characterisation provided promising results, in particular with respect to the photon detection efficiency. By customising the simulation tools, a reliable description of the devices was achieved. In addition, conceptual studies of the next device generation demonstrated the possibility of single cell readout, expanding the application range of those detectors to particle tracking.

  16. Avaliao de modelo de extrao da gua do solo por sistemas radiculares divididos entre camadas de solo com propriedades hidrulicas distintas Evaluation of a root-soil water extraction model by root systems divided over soil layers with distinct hydraulic properties

    Directory of Open Access Journals (Sweden)

    Marlon Gomes da Rocha

    2010-08-01

    Full Text Available A avaliao da capacidade de razes de plantas em extrair gua do solo de grande importncia na modelagem da taxa de transpirao e, para entender o crescimento e rendimento vegetal e o balano de gua e de solutos no solo. Para testar um modelo de extrao radicular macroscpico baseado no processo em escala microscpica, descreveram-se os resultados de um experimento com plantas cujo sistema radicular foi dividido entre camadas de solo com propriedades hidrulicas contrastantes. Um experimento de lismetro dividido com plantas de sorgo foi realizado em Piracicaba-SP. Quatro lismetros com dois compartimentos separados fisicamente (split-pot foram construdos e preenchidos com material de dois tipos de solo de diferentes classes texturais (um solo de textura mdia - AR e outro de textura argilosa - AG. Durante um ms e meio foi imposto um regime hdrico, alternando a irrigao entre os compartimentos. O teor de gua nos compartimentos dos lismetros foi monitorado com TDR e tensimetros. O material dos dois solos foi analisado conforme mtodo-padro quanto s suas propriedades de reteno e conduo da gua. A densidade radicular foi determinada por pesagem no fim do experimento, tendo ficado em torno de duas vezes maior no solo AR do que no AG. Observou-se que a extrao de gua ocorreu preferencialmente do compartimento do lismetro com maior potencial de fluxo matricial. Em certas ocasies houve transferncia de gua do lado de maior para o de menor potencial de fluxo matricial, com a liberao da gua ao solo pelo sistema radicular (hydraulic lift. Para compensar o efeito da heterogeneidade da distribuio radicular e da atividade radicular, incluiu-se, no modelo, um fator emprico f de correo. O modelo testado descreveu bem 80 % das observaes com a utilizao de valores de f de 0,01506 e 0,003713, para os solos AR e AG, respectivamente. O modelo simulou a liberao de gua ao solo mais frequentemente do que ela ocorreu no experimento. Esse fato pode indicar que a resistncia interna do sistema radicular, no contabilizada pelo modelo, pode ter papel importante nas relaes hdricas na rizosfera.Evaluating plant root capacity in extrating water from the soil is important for transpiration modeling and to understand crop growth and yield and soil water and nutrient balance. Aiming to test a macroscopic root water extraction model based on the microscopic process description, an experiment was described in which the root system of plants penetrated different soil layers with contrasting hydraulic properties. Four lysimeters containing two physically divided compartments were built and filled with material of two soils with different texture (a medium textured soil - AR and a clayey soil - AG. During a month and a half a water regime was imposed alternating the irrigation among the compartments. The soil water content in the compartments was measured with TDR and tensiometers. Soil hydraulic properties - retention and conductivity - were analyzed by standard methods. Root density was determined by weighing at the end of the experiment, resulting in values twice as high in AR than in AG soil. It was observed that water extraction occurred preferentially from the lysimeter compartments with the highest matric flux potential. Occasionally, water transfer from the compartment with higher matric flux potential to the lower one was observed, releasing water from root to soil (hydraulic lift. To compensate for the effect of heterogeneity of root distribution and root activity and soil-root contact, an empirical factor f was added to the model. Its value was determined by a numerical fitting procedure aiming at the highest correlation between model and observation in the four lysimeters. The model described 80% of the observations satisfactorily by using these f values, which were 0.01506 and 0.003713, respectively, for AR and AG. Model predictions indicated a much more frequent water release from roots to soil than observed in the experimen

  17. Digital Divide and Social Media: Connectivity Doesn’t End the Digital Divide, Skills Do

    OpenAIRE

    Radovanovic, Danica

    2011-01-01

    Whether we like it or not, we live in a very unequal and stratified world. We live in societies in which inequality is ignored in education, science, and in the social media. As Internet technologies are rapidly evolving and new digital divides on the Internet emerge, we must move beyond, at some point, a singular concern over Internet access and technological infrastructure issues. We must tackle socio-cultural differences, we must focus on Internet skills, literacies and social media usage.

  18. "Enlivening and - Dividing": An Aporia of Illumination

    Directory of Open Access Journals (Sweden)

    Hans Christian Hönes

    2015-08-01

    Full Text Available Normal 0 false false false EN-US JA X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:Verdana;} In 1798, Karl August Böttiger paid a nocturnal visit to the Gallery of Antiques in Dresden, illuminating the statues with a torch. At first glance, this seems to be yet another example of a popular practice for visiting galleries c.1800. Illuminating the sculptures by torchlight was a popular means of enlivening the objects, set in motion by the light flickering on their surfaces. The collections were thus meant to become a place where cold, white stone comes to life, and where the beholder becomes part of a revived antiquity.This was precisely what Böttiger intended, too. But to him, the effect of the torchlight appeared to be, as he wrote, “enlivening and – dividing!” The torchlight highlighted not only the beauty of the sculptures but also their modern restorations. Böttiger apparently failed to experience the living presence of the antique celebrated by many of his contemporaries (e.g. Goethe, Moritz.This essay focuses on the consequence of such a perception of sculptures as historically multi-layered objects. Böttiger’s experience resulted in a problematic situation. In trying to view the sculptures as contemporaries, he hoped to become ancient himself. But this operation failed in the moment when the sculptures themselves appeared to be anachronistic, impure palimpsests. In consequence, galleries may not only be the place were art history as chronological Stilgeschichte was born. They may also be the site where this perception changed into the experience of a more chaotic shape of time.

  19. Versatile tunable current-mode universal biquadratic filter using MO-DVCCs and MOSFET-based electronic resistors.

    Science.gov (United States)

    Chen, Hua-Pin

    2014-01-01

    This paper presents a versatile tunable current-mode universal biquadratic filter with four-input and three-output employing only two multioutput differential voltage current conveyors (MO-DVCCs), two grounded capacitors, and a well-known method for replacement of three grounded resistors by MOSFET-based electronic resistors. The proposed configuration exhibits high-output impedance which is important for easy cascading in the current-mode operations. The proposed circuit can be used as either a two-input three-output circuit or a three-input single-output circuit. In the operation of two-input three-output circuit, the bandpass, highpass, and bandreject filtering responses can be realized simultaneously while the allpass filtering response can be easily obtained by connecting appropriated output current directly without using additional stages. In the operation of three-input single-output circuit, all five generic filtering functions can be easily realized by selecting different three-input current signals. The filter permits orthogonal controllability of the quality factor and resonance angular frequency, and no inverting-type input current signals are imposed. All the passive and active sensitivities are low. Postlayout simulations were carried out to verify the functionality of the design. PMID:24982963

  20. A new measurement method of magnetic flux density using magnetorheological fluid characteristics and a variable resistor circuit

    Science.gov (United States)

    Kim, Hwan-Choong; Han, Chulhee; Kim, Pyunghwa; Choi, Seung-Bok

    2015-08-01

    This work proposes a new approach with which to measure the magnetic flux density using the characteristics of magnetorheological fluid (MRF) that is integrated with a variable resistor. For convenience, it is called a magnetorheological fluid variable resistor (MRF-VR) system in this study. The mechanism of the MRF-VR is based on the interaction between ferromagnetic iron particles of the MRF due to an external magnetic field, which causes its electrical resistance to be field dependent. Using this salient principle, the proposed MRF-VR system is constructed with electrodes and MRF, and its performance is demonstrated by evaluating its electrical resistive characteristics such as dimensional influence, response time, hysteresis and frequency response. After evaluating the performance characteristics, a feedback control system with a proportional-integral-derivative (PID) controller is established, and resistance-trajectory control experiments are carried out. Based on this MRF-VR system, a magnetic field-sensing system is constructed using a Wheatstone bridge circuit, and a polynomial model for calculating the magnetic flux density is formulated from the measured voltage. Finally, the accuracy and effectiveness of the proposed sensing system associated with the empirical polynomial model is successfully verified by comparing the calculated values of magnetic flux density with those measured by a commercial tesla meter.

  1. OSL and TL of Resistors of Mobile Phones for Retrospective Accident Dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J. I.; Kim, J. L.; Pradhan, A. S.; Chang, I.; Kim, B. H. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-05-15

    Optically stimulated luminescence (OSL) and thermoluminescence (TL) of ubiquitous materials continue to draw wider attention for individual dosimetry in nuclear and radiation accidents. Use of ubiquitous objects for radiation dosimetry is preferred because the affected persons in such unexpected events are usually not covered by personal dosimetry services and do not carry personal dosimeters. Often accident sites do not have area monitoring system in place. As the main concern of the dosimetry is health effects, a quick distinction of level of exposures of the affected persons for the required medical care becomes important in all accidents involving radiation. Both in large scale nuclear accidents such Fukushima, Chernobyl or Hiroshima and Nagasaki where large population around the accident site get exposed to radiation (evacuation is based on doses) and in smaller but panicky events, such as misuse of radiological exposure device (RED), radiological dispersive device (RDD: 'Dirty Bomb'), improvised nuclear device (IND) and deliberate dispersal of radioactive contaminants, a need for an ubiquitous personal dosimeter is well recognized. As biological dosimetry systems are yet to become viable for measurements of doses with required accuracy and speed, use of physical dosimeters is often explored. Among the various types of physical dosimetry systems, use of TL and OSL by processing common material such as bricks or tiles and measuring the doses cumulated for long periods of time has already become an accepted tool for large scale nuclear accidents such as Hiroshima and Nagasaki or Chernobyl involving higher doses. In the other potential cases of unexpected situations where the doses encountered could be much lower (even to escape the range of remotely installed area monitors), the need to measure even the low doses in shortest possible time becomes important. It is often realized that in such situations, the main problem could become the panic at the work place and in the public rather than actual health hazard due to radiation exposure. Therefore, a quick demonstration of measurement of doses following the accident is needed to reassure those receiving insignificant or low level of exposures that they are quite safe and need no treatment. This confidence building also becomes an important aspect of dosimetry. As the ranges of doses which could be encountered in such situations may vary from the background level to significantly high doses depending on the type of accident / incident and the location of personnel, it becomes important that the techniques used in retrospective dosimetry should be very sensitive and should be able to measure doses in a wide range from background level to several Gy. More recently, with the increasing apprehensions of nuclear terrorism / dirty bomb, research and developments in retrospective dosimetry has gained a new momentum the world over. Among the TL and OSL sensitive materials, the extraction and the processing of the materials from bricks and roof tiles is a very time consuming process and gives indirect estimate of individual doses. On the other hand, TL and OSL properties of components of electronic devices mobile phones, i-pods, black-berries, mp3 players and USB sticks containing ceramics with luminescence properties (e.g resistors, capacitors, resonators, antenna switches, transistors etc.) and chip cards containing silica epoxy (e.g. credit cards, bank cards, social security card, telephone card, SIM cards, ID cards e.g) are being considered very attractive and being evaluated. In this study, the TL and OSL properties of the electronic components of mobile phones are investigated and dose recovery potential is evaluated with a presumption that a mobile phone has become a part of body belongings masses of almost ages

  2. OSL and TL of Resistors of Mobile Phones for Retrospective Accident Dosimetry

    International Nuclear Information System (INIS)

    Optically stimulated luminescence (OSL) and thermoluminescence (TL) of ubiquitous materials continue to draw wider attention for individual dosimetry in nuclear and radiation accidents. Use of ubiquitous objects for radiation dosimetry is preferred because the affected persons in such unexpected events are usually not covered by personal dosimetry services and do not carry personal dosimeters. Often accident sites do not have area monitoring system in place. As the main concern of the dosimetry is health effects, a quick distinction of level of exposures of the affected persons for the required medical care becomes important in all accidents involving radiation. Both in large scale nuclear accidents such Fukushima, Chernobyl or Hiroshima and Nagasaki where large population around the accident site get exposed to radiation (evacuation is based on doses) and in smaller but panicky events, such as misuse of radiological exposure device (RED), radiological dispersive device (RDD: 'Dirty Bomb'), improvised nuclear device (IND) and deliberate dispersal of radioactive contaminants, a need for an ubiquitous personal dosimeter is well recognized. As biological dosimetry systems are yet to become viable for measurements of doses with required accuracy and speed, use of physical dosimeters is often explored. Among the various types of physical dosimetry systems, use of TL and OSL by processing common material such as bricks or tiles and measuring the doses cumulated for long periods of time has already become an accepted tool for large scale nuclear accidents such as Hiroshima and Nagasaki or Chernobyl involving higher doses. In the other potential cases of unexpected situations where the doses encountered could be much lower (even to escape the range of remotely installed area monitors), the need to measure even the low doses in shortest possible time becomes important. It is often realized that in such situations, the main problem could become the panic at the work place and in the public rather than actual health hazard due to radiation exposure. Therefore, a quick demonstration of measurement of doses following the accident is needed to reassure those receiving insignificant or low level of exposures that they are quite safe and need no treatment. This confidence building also becomes an important aspect of dosimetry. As the ranges of doses which could be encountered in such situations may vary from the background level to significantly high doses depending on the type of accident / incident and the location of personnel, it becomes important that the techniques used in retrospective dosimetry should be very sensitive and should be able to measure doses in a wide range from background level to several Gy. More recently, with the increasing apprehensions of nuclear terrorism / dirty bomb, research and developments in retrospective dosimetry has gained a new momentum the world over. Among the TL and OSL sensitive materials, the extraction and the processing of the materials from bricks and roof tiles is a very time consuming process and gives indirect estimate of individual doses. On the other hand, TL and OSL properties of components of electronic devices mobile phones, i-pods, black-berries, mp3 players and USB sticks containing ceramics with luminescence properties (e.g resistors, capacitors, resonators, antenna switches, transistors etc.) and chip cards containing silica epoxy (e.g. credit cards, bank cards, social security card, telephone card, SIM cards, ID cards e.g) are being considered very attractive and being evaluated. In this study, the TL and OSL properties of the electronic components of mobile phones are investigated and dose recovery potential is evaluated with a presumption that a mobile phone has become a part of body belongings masses of almost ages

  3. Bridging the Digital Divide: A Myth or Reality ?

    OpenAIRE

    Zablon Akoko Mbero; Sampson Dankyi ASARE

    2013-01-01

    Researchers have been documenting about the digital divide between developing countries and developed countries since 1970s. Some experts in areas like Public Policy, Communications, Business Management and Economics have also addressed the phenomenon of digital divide since the 1990s. We are in the 21st century and still there is the same old talk of digital divide amongst these researchers. One wonders whether digital divide will continue forever and whether we will ever a...

  4. A Compound Generic Quantitative Framework for Measuring Digital Divide

    OpenAIRE

    Noureldien A. Noureldien

    2014-01-01

    The term digital divide had been used in the literature to conceptualize the gap in using and utilizing information and communication technologies. Digital divide can be identified on different levels such as individuals, groups, societies, organizations and countries. On the other hand, the concept of e-Inclusion is coined to define activities needed to bridge digital divide. One of the most challenging research areas in digital divide that had been a subject for exhaustive studies is measur...

  5. Policy Options to Combat the Digital Divide in Western Europe

    OpenAIRE

    Rod Carveth; Susan B. Kretchmer

    2002-01-01

    This paper reviews the digital divide in Western Europe, as well as policy options for combating that divide. While age, income and gender are significant predictors of the digital divide in Western Europe, geography plays a crucial role. The countries in Southern Europe have less computer and Internet penetration than their Northern European counterparts. The paper then discusses four policy options for combating the divide, suggesting that the most effective solution would be private/public...

  6. The Digital Divide in the Liberal State: a Canadian Perspective

    OpenAIRE

    Birdsall, William F.

    2000-01-01

    The "digital divide" has emerged as a public policy challenge. This paper examines universal access public policy development in Canada within a North American context and its implications for addressing the digital divide. It concludes that the digital divide will not be eliminated either through public policy or the market due to the liberal public philosophy that is unique to and so strong in North America. The concept of the digital divide represents the dual structure characteristic of N...

  7. Investigation on powder metallurgy Cr-Si-Ta-Al alloy target for high-resistance thin film resistors with low temperature coefficient of resistance

    International Nuclear Information System (INIS)

    The sputtering target for high-resistance thin film resistors plays a decisive role in temperature coefficient of resistance (TCR). Silicon-rich chromium (Cr)-silicon (Si) target was designed and smelted for high-resistance thin film resistors with low TCR. Valve metal tantalum (Ta) and aluminum (Al) were introduced to the Cr-Si target to improve the performance of the target prepared. The measures for grain refining in smelting Cr-Si-Ta-Al target were taken to improve the performance of the prepared target. The mechanism and role of grain refinement were discussed in the paper. The phase structure of the prepared target was detected by X-ray diffraction (XRD). Rate of temperature drop was studied to reduce the internal stress of alloy target and conquer the easy cracking disadvantage of silicon-rich target. The electrical properties of sputtered thin film resistors were tested to evaluate the performance of the prepared target indirectly.

  8. Digital divide in education : a shift to ethical usage

    OpenAIRE

    Lau, Kai-kwong, Gervas; 劉啟光

    2014-01-01

    Under the trend of ICT implementation in education, students’ learning becomes highly reliant on ICT. A student will thus suffer in his / her learning process if he / she lacks the chance of using ICT at home. This is what a divide in student’s learning is. As the occurrence of this divide is due to digital ICT devices and its effect is focussed on students’ academic performance, such divide is termed as digital divide in education (DDE). To bridge this divide, most governments around the wor...

  9. Gentilly-2 and Point Lepreau divider plate replacement

    International Nuclear Information System (INIS)

    The steam generators at Hydro Quebec's Gentilly-2 and New Brunswick Power's Point Lepreau Nuclear Plants have been in operation since 1983, and were built with primary divider plates of a bolted panel configuration. During a routine outage inspection at Gentilly-2, it was noted that two bolts had dislodged from the divider plate and were located lying in the primary head. Subsequent inspections revealed erosion damage to a a substantial number of divider plate bolts and to a lesser extent, to the divider plate itself. After further inspection and repair the units were returned to operation, however, it was determined that a permanent replacement of the primary divider plates was going to be necessary. Upon evaluation of various options, it was decided that the panel type divider plates would be replaced with a single piece floating design. The divider plate itself was to be of one piece all-welded arrangement to be constructed from individual panels to be brought in through the manways. In view of the strength limitations of the bolted attachment of the upper seat bar to the tubesheet, a new welded seat was was provided. To counteract erosion concerns, the new divider plate is fitted with erosion resistant inserts of weld buildup and with improved sealing features in order to minimize leakage and erosion. At an advanced stage in the design and manufacture of the components, the issue of divider plate strength during loss of coolant accident (LOCA) conditions came into focus. Analysis was performed to determine the strength and/or failure characteristics of the divider plate to a variety of small and large LOCA conditions. Subsequently, Point Lepreau decided to replace their divider plates to address LOCA concerns. The paper describes the diagnosis of the original divider plates and the design. manufacture, field mobilization, installation and subsequent operation of the replacement divider plates. (author)

  10. Layer dividing and zone dividing of physical property of crust and deep structure in Jiangxi province

    International Nuclear Information System (INIS)

    On the base of summing experiences both at home and abroad, the Bugar gravitative anomalies are studied by major means of data processing. According to the anomalous character, three layer crust models (surface layer, middle layer in region and material layer under crust) are built up, depth of upper and bottom surfaces for every layer is calculated quantitatively, their varied characters of depth are studied and deep geological tectonics are outlined. The 'density' and 'mass' of every layer are calculated, and according to these two parameters, the shallow geological tectonics are researched. The relation-factor R between the surface altitude and Bugar gravitative anomalies are calculated and the stable or unstable crust zones are divided. The favorable mine zones for uranium deposit in Jiangxi Province are outlined

  11. Integrated one diode-one resistor architecture in nanopillar SiOx resistive switching memory by nanosphere lithography.

    Science.gov (United States)

    Ji, Li; Chang, Yao-Feng; Fowler, Burt; Chen, Ying-Chen; Tsai, Tsung-Ming; Chang, Kuan-Chang; Chen, Min-Chen; Chang, Ting-Chang; Sze, Simon M; Yu, Edward T; Lee, Jack C

    2014-02-12

    We report on a highly compact, one diode-one resistor (1D-1R) nanopillar device architecture for SiOx-based ReRAM fabricated using nanosphere lithography (NSL). The intrinsic SiOx-based resistive switching element and Si diode are self-aligned on an epitaxial silicon wafer using NSL and a deep-Si-etch process without conventional photolithography. AC-pulse response in 50 ns regime, multibit operation, and good reliability are demonstrated. The NSL process provides a fast and economical approach to large-scale patterning of high-density 1D-1R ReRAM with good potential for use in future applications. PMID:24369783

  12. The dependence of crystallization on temperature in the nanosecond timescale for GeTe-based fast phase-change resistor

    Science.gov (United States)

    Zhang, Hui; Zhang, Yulong; Yin, You; Hosaka, Sumio

    2016-04-01

    We propose an approach to study the dependence of crystallization on temperature of GeTe-based phase change resistor (PCR) for staircase-shaped voltage pulses. We tune the resistance between the amorphous and crystalline states via varying the width of second subpulse. Then, the crystallized fractions are calculated as a function of the second subpulse widths. Furthermore, the temperature distributions under variable second subpulses are analyzed. At last, the pulse-dependent-recrystallization-temperatures are estimated using experimental and simulation results. We demonstrate that the crystallization of the GeTe-PCR is faster than that of Ge2Sb2Te5-PCR due to the high pulse-dependent-recrystallization-temperature and low activation energy.

  13. Ion-implanted capacitively coupled silicon strip detectors with integrated polysilicon bias resistors processed on a 100 mm wafer

    International Nuclear Information System (INIS)

    Double-sided silicon strip detectors with integrated coupling capacitors and polysilicon resistors have been processed on a 100 mm wafer. A detector with an active area of 19x19 mm2 was connected to LSI readout electronics and tested. The strip pitch of the detector is 25 ?m on the p-side and 50 ?m on the n-side. The readout pitch is 50 ?m on both sides. The number of readout strips is 774 and the total number of strips is 1161. On the p-side a signal-to-noise of 35 has been measured using a 90Sr ?-source. The n-side has been studied using a laser. (orig.)

  14. Prediction of multiple resonance characteristics by an extended resistor-inductor-capacitor circuit model for plasmonic metamaterials absorbers in infrared.

    Science.gov (United States)

    Xu, Xiaolun; Li, Yongqian; Wang, Binbin; Zhou, Zili

    2015-10-01

    The resonance characteristics of plasmonic metamaterials absorbers (PMAs) are strongly dependent on geometric parameters. A resistor-inductor-capacitor (RLC) circuit model has been extended to predict the resonance wavelengths and the bandwidths of multiple magnetic polaritons modes in PMAs. For a typical metallic-dielectric-metallic structure absorber working in the infrared region, the developed model describes the correlation between the resonance characteristics and the dimensional sizes. In particular, the RLC model is suitable for not only the fundamental resonance mode, but also for the second- and third-order resonance modes. The prediction of the resonance characteristics agrees fairly well with those calculated by the finite-difference time-domain simulation and the experimental results. The developed RLC model enables the facilitation of designing multi-band PMAs for infrared radiation detectors and thermal emitters. PMID:26421549

  15. Hybrid voltage divider used for high voltage pulsed power measurement

    International Nuclear Information System (INIS)

    The principle and structure of a hybrid voltage divider are proposed and the calibration and experimental testing are carried out. The ideal response conditions of the divider are analyzed by using the simplified divider model, the attenuation characteristic of two-stage voltage dividing is discussed, and then an error control method is presented. Through load calibration, the pulsed voltage frequency response of the divider can be greater than 2.9 MHz with the largest pulse width of 40 μs, the attenuation ratio (or the attenuation coefficient) of 2. 60 kV/V and the measurement error of less than 5%. The divider has the merits of low cost, easy fabrication, and being capable of ns-to μs-level pulsed voltage measurement, and it can be applied to laboratory- scale pulsed power measurement. (authors)

  16. An Empirical Analysis of the Determinants of International Digital Divide

    Science.gov (United States)

    Yun, Liu

    International Digital Divide is an imbalance state of ICT penetration between countries. This paper analyzes the current status and trends of international digital divide, adopts Gompertz technology diffusion model to verify the determinants of ICT penetration level and diffusion rate separately. Finally, China should use "policy levers" to strengthen international trade cooperation, improve the capability of independent innovation, and achieve Chinese goal of bridging digital divide.

  17. Understanding the digital divide: A literature survey and ways forward

    OpenAIRE

    SRINUAN, Chalita; Bohlin, Erik

    2011-01-01

    The term digital divide was introduced in the mid-1990s and defined as the gap separating those who have access to new forms of information technology from those who do not. The digital divide remains an important public policy debate that encompasses social, economic and political issues. This paper presents a literature review and classification scheme for digital divide research. The review covers journal articles published between 2001 and 2010 in three types of journals: (1) Information ...

  18. The Apply of Frequency Divider Circuit in Nuclear Electronics

    International Nuclear Information System (INIS)

    Different components in a digital system often need different working frequencies, the way we often used is clock division from the system clock. Through the analysis of frequency divider principle, a applied integer frequency dividing circuit with SE120A is proposed. It can divide the frequency multiple from 2 to 64. It's usually used in nuclear electronics. It's testing and analysis is displayed that it has no noise, good frequency division effect and stability. (authors)

  19. Zones of silence: A framework beyond the digital divide

    OpenAIRE

    Potter, Amelia Bryne

    2006-01-01

    There is no doubt that much digital divide work including connectivity initiatives, technology transfer programs, and other projects is done with good intention. Yet, as has been widely recognized, the conceptual framework of the digital divide is limiting. The language of the digital divide not only places people into simplistic have/have not categories, making assumptions about the solution to information poverty with little attention to local contexts, its logic also continues a ...

  20. Manufacturing of precise resistors on the base Ni-P and Ni-W-P layers by means of chemical reduction method

    International Nuclear Information System (INIS)

    Chemical preparation method of Ni-P and Ni-W-P layers on resistive ceramics has been worked out. The method base on chemical reduction in aqueous solution. The composition of the initial solutions determine the properties of obtained metal layers and electrical properties of resistor in consequence. 5 refs

  1. Comparison of Wilkinson Power Divider And Gysel Power Divider Using Ads® For The Frequency Range of 3 Ghz

    Directory of Open Access Journals (Sweden)

    S.Banu

    2012-10-01

    Full Text Available Wilkinson Power Divider (WPD and Gysel Power Divider(GPD are two competing power dividers and a simple comparison between them helps in choosing the technology for particular application. In this paper, the performance of Wilkinson Power Divider and Gysel Power Divider are analyzed based on the insertion loss, return loss, and also the isolation between the output ports. The insertion loss and return loss of GPD is found to be lower about -3.061dB and -13.754dB respectively when compared with WPD at a center frequency of 1.5GHz. These losses of power dividers realized by microstrip line are analyzed with the operating frequency of 3GHz using ADS® software.

  2. The automatic complexity analysis of divide-and-conquer algorithms

    OpenAIRE

    Zimmermann, Paul; Zimmermann, Wolf

    1989-01-01

    Current tools performing automatic complexity analysis are capable to deal with function definitions based on structural induction. Divide-and-conquer algorithms with "intelligent" divide function (like quicksort) are not based on structural induction, but on noetherian induction. This paper presents a method of automatic complexity analysis to deal with such kinds of functions.

  3. X-Band Strip-Line Power Divider/Combiner

    Science.gov (United States)

    Conroy, B. L.

    1985-01-01

    Strip-line circuit for X-band signals both divides and combines microwave power for distributed amplifier. Strip-line pattern (foil pattern over insulating layer over ground plane) laid out so all eight distributed ports lie at electrical distances of odd integral multiples of half wavelength from main input/output port. Strip line used as power divider and as power combiner.

  4. Modified Wilkinson Power Dividers For K And Ka Bands

    Science.gov (United States)

    Antsos, Dimitrios

    1995-01-01

    Modified configuration for Wilkinson power dividers devised for operating frequencies in K and Ka bands (18 to 27 and 27 to 40 GHz, respectively). Overcomes some difficulties associated with increasing frequency, making possible to design and accurately predict performances of unequal-split power dividers for frequencies above X-band.

  5. The Digital Divide (DD): A Reconceptualization for Educators.

    Science.gov (United States)

    Harper, Vernon

    2003-01-01

    Discussion of the digital divide focuses on a social divide rather than a lack of access to information technology for specific groups. Topics include historic trends in technology diffusion; policy implications; motivational barrier to technology use; knowledge and skill barrier; content barrier; and social network barrier. (LRW)

  6. The Digital Divide and Health Outcomes: A Teleretinal Imaging Study

    Science.gov (United States)

    Connolly, Kathleen Kihmm

    2013-01-01

    The purpose of this research project was to understand, explore and describe the digital divide and the relationship between technology utilization and health outcomes. Diabetes and diabetic eye disease was used as the real-life context for understanding change and exploring the digital divide. As an investigational framework, a telemedicine…

  7. The Digital Divide and Health Outcomes: A Teleretinal Imaging Study

    Science.gov (United States)

    Connolly, Kathleen Kihmm

    2013-01-01

    The purpose of this research project was to understand, explore and describe the digital divide and the relationship between technology utilization and health outcomes. Diabetes and diabetic eye disease was used as the real-life context for understanding change and exploring the digital divide. As an investigational framework, a telemedicine

  8. Distance Education and the Digital Divide: An Academic Perspective

    Science.gov (United States)

    Block, Judy

    2010-01-01

    This paper will address how the digital divide affects distance education. Lack of access for some students does raise concerns. Access to technology is often defined by what students don't have: what is called a digital divide. Access also is defined by the speed of Internet connections. Access in the future will be even greater as more computers

  9. Rethinking the Digital Divide: Impacts on Student-Tutor Relationships

    Science.gov (United States)

    Underwood, Jean D. M.

    2007-01-01

    This article emerged from a series of debates and workshops on the impact of the Digital Divide on educational practice at the "Futures of Learning: New Learning Paradigms Conference" in Paris. The conceptualisation of the Digital Divide into the "haves" and the "have-nots", with a perception of the economically developed world as "high tech" and

  10. The Digital Divide: The Special Case of Gender

    Science.gov (United States)

    Cooper, J.

    2006-01-01

    This paper examines the evidence for the digital divide based on gender. An overview of research published in the last 20 years draws to the conclusion that females are at a disadvantage relative to men when learning about computers or learning other material with the aid of computer-assisted software. The evidence shows that the digital divide

  11. The Digital Divide in Health Education: Myth or Reality?

    Science.gov (United States)

    Stellefson, Michael; Chaney, Beth; Chaney, Don

    2008-01-01

    Although e-health interventions provide new opportunities for health education, there has been cause for concern regarding the purported information technology gap between those who have access to digital applications and those who do not--termed the "digital divide." The literature suggests, however, that this divide may now be illusory, driven

  12. Bridging the Digital Divide--An Australian Story

    Science.gov (United States)

    Broadbent, Robyn; Papadopoulos, Theo

    2013-01-01

    There is increasing evidence that the lack of access to information and communication technology (ICT) or the "digital divide" severely limits education, employment and economic prospects. This paper reports on the evaluation of a project that aims to bridge the digital divide. In particular, the case study data has been used to bring to life the

  13. $f(T)$ models with phantom divide line crossing

    OpenAIRE

    Wu, Puxun; Yu, Hongwei

    2010-01-01

    In this paper, we propose two new models in $f(T)$ gravity to realize the crossing of the phantom divide line for the effective equation of state, and we then study the observational constraints on the model parameters. The best fit results suggest that the observations favor a crossing of the phantom divide line.

  14. Water

    Science.gov (United States)

    ... www.girlshealth.gov/ Home Nutrition Nutrition basics Water Water Did you know that water makes up more ... to drink more water Other drinks How much water do you need? top Water is very important, ...

  15. Three-dimensional multiway power dividers based on transformation optics

    Science.gov (United States)

    Wu, Yong-Le; Zhuang, Zheng; Deng, Li; Liu, Yuan-An

    2016-04-01

    The two-dimensional (2D) or three-dimensional (3D) multiway power dividers based on transformation optical theory are proposed in this paper. It comprises of several nonisotropic mediums and one isotropic medium without any lumped and distributed elements. By using finite embedded coordinate transformations, the incident beam can be split and bent arbitrarily in order to achieve effective power division and transmission. In addition, the location of the split point can be employed to obtain unequal power dividers. Finally, several typical examples of the generalized power divider without limitation in 3D space are performed, which shows that the proposed power divider can implement required functions with arbitrary power division and arbitrary transmission paths. The excellent simulated results verify the novel design method for power dividers.

  16. Three-dimensional multiway power dividers based on transformation optics

    Science.gov (United States)

    Wu, Yong-Le; Zhuang, Zheng; Deng, Li; Liu, Yuan-An

    2016-01-01

    The two-dimensional (2D) or three-dimensional (3D) multiway power dividers based on transformation optical theory are proposed in this paper. It comprises of several nonisotropic mediums and one isotropic medium without any lumped and distributed elements. By using finite embedded coordinate transformations, the incident beam can be split and bent arbitrarily in order to achieve effective power division and transmission. In addition, the location of the split point can be employed to obtain unequal power dividers. Finally, several typical examples of the generalized power divider without limitation in 3D space are performed, which shows that the proposed power divider can implement required functions with arbitrary power division and arbitrary transmission paths. The excellent simulated results verify the novel design method for power dividers. PMID:27091541

  17. Social Support Quality in Internet Based Information and Communication: From "Digital Divide" to "Voice Divide"

    Directory of Open Access Journals (Sweden)

    2004-05-01

    Full Text Available National and international studies demonstrate that the number of teenagers using the inter-net increases. But even though they actually do have access from different places to the in-formation and communication pool of the internet, there is evidence that the ways in which teenagers use the net - regarding the scope and frequency in which services are used as well as the preferences for different contents of these services - differ significantly in relation to socio-economic status, education, and gender. The results of the regarding empirical studies may be summarised as such: teenager with low (formal education especially use internet services embracing 'entertainment, play and fun' while higher educated teenagers (also prefer intellectually more demanding and particularly services supplying a greater variety of communicative and informative activities. More generally, pedagogical and sociological studies investigating "digital divide" in a dif-ferentiated and sophisticated way - i.e. not only in terms of differences between those who do have access to the Internet and those who do not - suggest that the internet is no space beyond 'social reality' (e.g. DiMaggio & Hargittai 2001, 2003; Vogelgesang, 2002; Welling, 2003. Different modes of utilisation, that structure the internet as a social space are primarily a specific contextualisation of the latter - and thus, the opportunities and constraints in virtual world of the internet are not less than those in the 'real world' related to unequal distribu-tions of material, social and cultural resources as well as social embeddings of the actors involved. This fact of inequality is also true regarding the outcomes of using the internet. Empirical and theoretical results concerning forms and processes of networking and commu-nity building - i.e. sociability in the internet, as well as the social embeddings of the users which are mediated through the internet - suggest that net based communication and infor-mation processes may entail the resource 'social support'. Thus, with reference to social work and the task of compensating the reproduction of social disadvantages - whether they are medial or not - the ways in which teenagers get access to and utilize net based social sup-port are to be analysed.

  18. On the Thurston-Bennequin invariant of graph divide links

    CERN Document Server

    Ishikawa, M

    2004-01-01

    In the present paper we determine the Thurston-Bennequin invariant of graph divide links, which include all closed positive braids, all divide links and certain negative twist knots. As a corollary of this and a result of P. Lisca and A.I. Stipsicz, we prove that the 3-manifold obtained from the 3-sphere by Dehn surgery along a non-trivial graph divide knot K with coefficient r carries positive, tight contact structures for every r except the Thurston-Bennequin invariant of K.

  19. Dividing Attention Lowers Children's but Increases Adults' False Memories

    OpenAIRE

    Otgaar, H.; Peters, M.; Howe, M. L.

    2012-01-01

    The present study examined the impact of divided attention on children’s and adults’ neutral and negative true and false memories in a standard DRM paradigm. Children (7- and 11-year-olds; n = 126) and adults (n = 52) received 5 neutral and 5 negative DRM word lists where half of each group received a divided attention task. The results showed that divided attention affected children’s and adults’ false memory levels differently, but did not alter true memory differently. Specifically, our re...

  20. Families of zero cycles and divided powers: I. Representability

    OpenAIRE

    Rydh, David

    2008-01-01

    For any separated algebraic space $X/S$ we construct a separated algebraic space $\\Gamma^d(X/S)$ -- the space of divided powers -- which parameterizes zero cycles of degree $d$ on $X$. The space of divided powers for an affine scheme is given by the spectrum of the algebra of divided powers. In characteristic zero or when $X/S$ is flat, the constructed space coincides with the symmetric product $Sym^d(X/S)$. We also prove several fundamental results on the kernels of multiplicative polynomial...

  1. Water

    Science.gov (United States)

    ... drinking water by consuming only bottled water or water from a filtration system that has been certified by an independent ... 15 ppb, CDC recommends using bottled water or water from a filtration system that has been certified by an independent ...

  2. Chameleon Cosmology Model Describing the Phantom Divide Line Crossing

    OpenAIRE

    F. Cannata(INFN, Bologna); Kamenshchik, A. Yu.

    2010-01-01

    An exact solution describing the evolution of the type Bang-to-Rip with the phantom divide line crossing is constructed in the Chameleon cosmology model, based on two independent functions of the scalar field.

  3. Hyperglycemia diverts dividing stem cells to pathological adipogenesis

    OpenAIRE

    Hascall, Vincent; Wang, Aimin

    2014-01-01

    This commentary proposes a mechanism for why murine diabetic adipose tissue contains very few remaining stem cells compared with normal adipose tissue. The mechanism involves the diversion of stem cells to pathological adipocytes when they divide in hyperglycemia.

  4. Pulse swallowing frequency divider with low power and compact structure

    International Nuclear Information System (INIS)

    A pulse swallowing frequency divider with low power and compact structure is presented. One of the DFFs in the divided by 2/3 prescaler is controlled by the modulus control signal, and automatically powered off when it has no contribution to the operation of the prescaler. The DFFs in the program counter and the swallow counter are shared to compose a compact structure, which reduces the power consumption further. The proposed multi-modulus frequency divider was implemented in a standard 65 nm CMOS process with an area of 28 × 22 μm2. The power consumption of the divider is 0.6 mW under 1.2 V supply voltage when operating at 988 MHz. (semiconductor integrated circuits)

  5. Pulse swallowing frequency divider with low power and compact structure

    Science.gov (United States)

    Haijun, Gao; Lingling, Sun; Chaobo, Cai; Haiting, Zhan

    2012-11-01

    A pulse swallowing frequency divider with low power and compact structure is presented. One of the DFFs in the divided by 2/3 prescaler is controlled by the modulus control signal, and automatically powered off when it has no contribution to the operation of the prescaler. The DFFs in the program counter and the swallow counter are shared to compose a compact structure, which reduces the power consumption further. The proposed multi-modulus frequency divider was implemented in a standard 65 nm CMOS process with an area of 28 × 22 μm2. The power consumption of the divider is 0.6 mW under 1.2 V supply voltage when operating at 988 MHz.

  6. Annan warns of 'content divide' between rich and poor

    CERN Multimedia

    Dickson, D

    2003-01-01

    "The Secretary-General of the United Nations, Kofi Annan, warned today (10 December) that a "content divide" is threatening to deprive developing countries of the full benefits offered by information and communications technologies (ICTs)" (1 page)

  7. Continental Divide of the United States - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior This map layer portrays the Continental Divide of the United States. The map layer was created by extracting Hydrologic Unit Boundary line features from an existing...

  8. Narrowing the Digital Divide in Low-Income, Urban Communities

    Science.gov (United States)

    Norris, Daniel T.; Conceicao, Simone

    2004-01-01

    The digital divide is leaving millions disenfranchised from the opportunity to use technology to change their lives and to participate fully in democracy, in their own communities, and in today's job market.

  9. Digital divide or digital development?: The Internet in Mexico

    OpenAIRE

    Curry, James; Kenney, Martin

    2006-01-01

    This paper discusses the development of the Internet in Mexico within the context of the digital divide. There is skepticism about whether the digital divide is something driven primarily by technology rather than an epiphenomenon driven by socioeconomic factors. The barriers to access are not technological but rather economic and historical. Although Mexico shows wide disparities in Internet access, it also shows rapid development toward more access. The number of regular Internet users in M...

  10. Afterword. Internet Freedom, Nuanced Digital Divide, and the Internet Craftsman

    OpenAIRE

    Meinrath, Sascha D; Losey, James; Lennett, Benjamin

    2013-01-01

    This book provides an in-depth comparative analysis of inequality and the stratification of the digital sphere. Grounded in classical sociological theories of inequality, as well as empirical evidence, this book defines 'the digital divide' as the unequal access and utility of internet communications technologies and explores how it has the potential to replicate existing social inequalities, as well as create new forms of stratification. The Digital Divide examines how various demographic an...

  11. Wireless Technologies Bridging the Digital Divide in Education

    OpenAIRE

    Gerard Smyth

    2006-01-01

    The objective of this paper is to demonstrate how the latest wireless standards and technologies may overcome the digital divide in education in the developed and developing worlds. The concept of the digital divide is discussed in the traditional socio-economic sense and expanded in terms of the learner's location, age, culture and background. It is important that we understand the full extent and complexities of this division if we are to effectively bridge it. Why and how the digital div...

  12. Digital Divide: Determinants and Policies with Special Reference to Asia

    OpenAIRE

    Quibria, M.G.; Ahmed, Shamsun N.; Tschang, Ted; Reyes-Macasaquit, Mari-Len

    2002-01-01

    "Access to new information and communication technologies (ICT) remains extremely unequally distributed across and within societies. While there have been a good deal of popular discussions about this "digital divide", not much is known about the quantitative significance of its various determinants. By undertaking a set of crosscountry regressions, the paper finds that income, education, and infrastructure play a critical role in shaping the divide. Based on this analysis, the paper also off...

  13. THE DIGITAL DIVIDE: HOW WIDE AND HOW DEEP?

    OpenAIRE

    Schloman, Barbara F.

    2004-01-01

    The complexity of the issues that make up the digital divide problem is better understood today. It is no longer sufficient to see it simply as a disparity of access to computer technology. Rather, there is recognition that having meaningful support for using the technology is also an essential ingredient for getting online. The digital divide is a global problem, but even in the technology rich United States the situation is troubling. Recent studies have shown that within the United States,...

  14. The Role of Infrastructure in the Rural - Urban Digital Divide

    OpenAIRE

    Whitacre, Brian E.; Mills, Bradford F.

    2005-01-01

    A significant gap exists in the percentage of rural and urban households that connect to the Internet. Furthermore, this "digital divide" has been increasing with respect to high-speed connections. The primary course of action to address this emerging high-speed digital divide has been to subsidize digital communications technology (DCT) infrastructure. This paper explores the diffusion of DCT infrastructure in both rural and urban areas over the period 2000 - 2003, and estimates its contribu...

  15. Effective use: A community informatics strategy beyond the Digital Divide

    OpenAIRE

    Gurstein, Michael

    2003-01-01

    A huge industry has been created responding to the perceived social malady, the "Digital Divide". This paper examines the concepts and strategies underlying the notion of the Digital Divide and concludes that it is little more than a marketing campaign for Internet service providers. The paper goes on to present an alternative approach - that of "effective use" - drawn from community informatics theory which recognizes that the Internet is not simply a source of information, but also a fundam...

  16. Thermosetting polyimide resin matrix composites with interpenetrating polymer networks for precision foil resistor chips based on special mechanical performance requirements

    Science.gov (United States)

    Wang, X. Y.; Ma, J. X.; Li, C. G.; Wang, H. X.

    2014-04-01

    Based on interpenetrating networks (IPNs) different macromolecular materials such as epoxy, phenolic, and silicone resin were chosen to modify thermosetting polyimide (TSPI) resin to solve the lack of performance when used for protecting precision foil resistor chips. Copolymerization modification, controlled at curing stage, was used to prepare TSPI composites considering both performance and process requirements. The mechanical properties related to trimming process were mainly studied due to the special requirements of the regularity of scratch edges caused by a tungsten needle. The analysis on scratch edges reveals that the generation and propagation of microcracks caused by scratching together with crack closure effect may lead to regular scratch traces. Experiments show that the elongation at break of TSPI composites is the main reason that determines the special mechanical properties. The desired candidate materials should have proper hardness and toughness, and the specific mechanical data are that the mean elongation at break and tensile strength of polymer materials are in the range of 9.2-10.4% and 100-107 MPa, respectively. Possible reasons for the effect of the modifiers chosen on TSPI polymers, the reaction mechanisms on modified TSPI resin and the IPN structure in TSPI composite polymers were discussed based on IR and TG analysis.

  17. A noble technique a using force-sensing resistor for immobilization-device quality assurance: A feasibility study

    Science.gov (United States)

    Cho, Min-Seok; Kim, Tae-Ho; Kang, Seong-Hee; Kim, Dong-Su; Kim, Kyeong-Hyeon; Shin, Dong-Seok; Noh, Yu-Yun; Koo, Hyun-Jae; Cheon, Geum Seong; Suh, Tae Suk; Kim, Siyong

    2016-03-01

    Many studies have reported that a patient can move even when an immobilization device is used. Researchers have developed an immobilization-device quality-assurance (QA) system that evaluates the validity of immobilization devices. The QA system consists of force-sensing-resistor (FSR) sensor units, an electric circuit, a signal conditioning device, and a control personal computer (PC) with in-house software. The QA system is designed to measure the force between an immobilization device and a patient's skin by using the FSR sensor unit. This preliminary study aimed to evaluate the feasibility of using the QA system in radiation-exposure situations. When the FSR sensor unit was irradiated with a computed tomography (CT) beam and a treatment beam from a linear accelerator (LINAC), the stability of the output signal, the image artifact on the CT image, and changing the variation on the patient's dose were tested. The results of this study demonstrate that this system is promising in that it performed within the error range (signal variation on CT beam < 0.30 kPa, root-mean-square error (RMSE) of the two CT images according to presence or absence of the FSR sensor unit < 15 HU, signal variation on the treatment beam < 0.15 kPa, and dose difference between the presence and the absence of the FSR sensor unit < 0.02%). Based on the obtained results, we will volunteer tests to investigate the clinical feasibility of the QA system.

  18. Trigonometrical sums connected with the chiral Potts model, Verlinde dimension formula, two-dimensional resistor network, and number theory

    Energy Technology Data Exchange (ETDEWEB)

    Chair, Noureddine, E-mail: n.chair@ju.edu.jo

    2014-02-15

    We have recently developed methods for obtaining exact two-point resistance of the complete graph minus N edges. We use these methods to obtain closed formulas of certain trigonometrical sums that arise in connection with one-dimensional lattice, in proving Scotts conjecture on permanent of Cauchy matrix, and in the perturbative chiral Potts model. The generalized trigonometrical sums of the chiral Potts model are shown to satisfy recursion formulas that are transparent and direct, and differ from those of Gervois and Mehta. By making a change of variables in these recursion formulas, the dimension of the space of conformal blocks of SU(2) and SO(3) WZW models may be computed recursively. Our methods are then extended to compute the corner-to-corner resistance, and the Kirchhoff index of the first non-trivial two-dimensional resistor network, 2N. Finally, we obtain new closed formulas for variant of trigonometrical sums, some of which appear in connection with number theory. -- Highlights: Alternative derivation of certain trigonometrical sums of the chiral Potts model are given. Generalization of these trigonometrical sums satisfy recursion formulas. The dimension of the space of conformal blocks may be computed from these recursions. Exact corner-to-corner resistance, the Kirchhoff index of 2N are given.

  19. Trigonometrical sums connected with the chiral Potts model, Verlinde dimension formula, two-dimensional resistor network, and number theory

    International Nuclear Information System (INIS)

    We have recently developed methods for obtaining exact two-point resistance of the complete graph minus N edges. We use these methods to obtain closed formulas of certain trigonometrical sums that arise in connection with one-dimensional lattice, in proving Scott’s conjecture on permanent of Cauchy matrix, and in the perturbative chiral Potts model. The generalized trigonometrical sums of the chiral Potts model are shown to satisfy recursion formulas that are transparent and direct, and differ from those of Gervois and Mehta. By making a change of variables in these recursion formulas, the dimension of the space of conformal blocks of SU(2) and SO(3) WZW models may be computed recursively. Our methods are then extended to compute the corner-to-corner resistance, and the Kirchhoff index of the first non-trivial two-dimensional resistor network, 2×N. Finally, we obtain new closed formulas for variant of trigonometrical sums, some of which appear in connection with number theory. -- Highlights: • Alternative derivation of certain trigonometrical sums of the chiral Potts model are given. • Generalization of these trigonometrical sums satisfy recursion formulas. • The dimension of the space of conformal blocks may be computed from these recursions. • Exact corner-to-corner resistance, the Kirchhoff index of 2×N are given

  20. On the extraction of the external drain and source resistors and effective channel length in Si-MOSFET

    Science.gov (United States)

    Joodaki, M.

    2015-09-01

    This paper focuses on the extraction of drain/source resistance and effective channel length (Leff) of the silicon MOSFET in the linear drain current region. Leff is expressed as a function of drain/source resistance, drain current, threshold voltage, drain voltage, and body-effect coefficient. Using this definition, an additional component of drain/source resistance in the linear drain current region, inversion charge reduction resistance (RΔQ), is introduced which results from the influence of drain/source resistors, internal source/body voltage and drain voltage on the total inversion charge. Finally, a new method for extraction of the drain/source resistance is developed. In this method several parameters that have impact on device behavior are considered. The parameters include gate voltage dependency, short channel effects, and poly gate length dependency. The results presented here are not only very useful for accurate device modeling and characterization, but are also vital to better understanding of the device physics. Furthermore, they can describe shortcomings of the other methods which use devices of different gate lengths. The extracted linear model provides less than 1.07% and 3.3% average absolute error and maximum error, respectively, for all seven devices under test over the gate voltage range of 0.75-2 V.

  1. Influence of heating in on-chip resistors on frequency-to-current conversion in short arrays of small Josephson junctions

    International Nuclear Information System (INIS)

    Small Josephson junctions can exhibit charge quantization effects and Bloch oscillations which are very much the electromagnetic dual to the behaviour of larger junctions. As such they can exhibit constant-current steps at I=2ef when an external drive of frequency f is applied, dual to the well-known constant-voltage Shapiro steps exhibited by larger junctions. This is of interest for a possible current standard. Observation of these steps demonstrating phase lock of the Bloch oscillations with the external drive requires a high-impedance environment for the junctions, which is provided by on-chip resistors close to the junctions. Those resistors will inevitably be heated by the produced current. We experimentally determine the temperature dependence of miniature on-chip resistors on heating current and present circuit simulations incorporating this data as well as realistic values for stray capacitances and junction parameters. These simulations show that with harmonic drive there is practically no parameter window where observation of a flat current plateau is possible. However, a pulsed drive analogous to what is employed for AC voltage standards could enable direct frequency-to-current conversion with current technology. We also discuss potential problems not addressed in the simulations, in particular non-equilibrium quasi-particles in the superconductor.

  2. Humidity sensing properties of WO3 thick film resistor prepared by screen printing technique

    International Nuclear Information System (INIS)

    Highlights: • Polycrystalline WO3 Thick films are fabricated by screen printing technique. • Monoclinic phases were the majority in formation of films. • The peak at 1643 cm−1 shows stretching vibrations attributed to W-OH of adsorbed H2O. • Absorption peaks in the range 879–650 cm−1 are attributed to the stretching W-O-W bonds. • Increase in resistance with decrease in RH when exposed to 20–100% RH. - Abstract: Thick films of tungsten oxide based were prepared using standard screen printing technique. To study the effect of temperature on the thick films were fired at different temperature for 30 min in air atmosphere. The WO3 thick films were characterized with X-ray diffraction, scanning electron microscopy and EDAX for elemental analysis. The formation of mixed phases of the film together with majority of monoclinic phase was observed. IR spectra confirm the peak at 1643 cm−1 clearly shows stretching vibrations attributed to the W-OH bending vibration mode of the adsorbed water molecules. The absorption peaks in the range 879–650 cm−1 are attributed to the stretching W-O-W bonds (i.e. ν [W-Ointer-W]). The peak located at 983 cm−1 belong to W=O terminal of cluster boundaries. A change in the resistance was observed with respect to the relative humidity when the WO3 thick films were exposed to a wide humidity range of 20–100%. An increasing firing temperature of WO3 film increases with the sensitivity. The parameters such as sensitivity and hysteresis of the WO3 film sensors have been evaluated

  3. [Promoting nursing competitiveness: introduction to the digital divide].

    Science.gov (United States)

    Lin, Chun-Hsu; Lee, Ting-Ting

    2010-02-01

    Increasingly sophisticated information technology (IT) has widened the gap (the so-called "digital divide") between those with effective access to IT resources and those without. Problems related to the digital divide exist in every country. In addition to level of familiarity with technology, the divide can also be influenced by factors of race, gender, age, education, economic status and area of residence. The digital divide may be ameliorated through technology innovations in terms of access to information, information application and information literacy. As IT is an increasingly significant component of modern healthcare, it may be expected that the "width" of the potential gap widens as IT applications increase in sophistication. Nursing professionals must keep abreast of advancing technologies in order to narrow the digital divide. To cope with this challenge, nursing professionals should enhance their understanding of new technologies beyond what is taught in formal education curricula. This knowledge enhancement may be attained through self learning or on-the-job training in nursing informatics. Content could cover hospital information system (IS) usage, security, applications and web access. This will improve the ability of nursing staff to face the current IT challenge. PMID:20127629

  4. Romania's Digital Divide and the Failures of E-Government

    Directory of Open Access Journals (Sweden)

    Sorin Dan ŞANDOR

    2006-02-01

    Full Text Available This paper tries to measure the level of the digital divide existing in Romania and also to verify its relationship with e-government. At the country level, Romania is one of the least digitally developed countries in Europe, but it has shown a sharp increase in recent years. At the social level, based on data from public opinion surveys, digital divide is analyzed at two levels: lack of access and lack of knowledge. The results are similar to those in other countries: digital divide appears along the same dimensions: rural/urban, age, education, wealth and, to a lesser extent, gender. E-government services, while presumed to be at an adequate level, are used only by a very small number of citizens, thus having no impact upon the digital divide. Confronted with a serious divide, and with great possibility of its increasing, Romania needs to promote policies designed to increase access and knowledge. Also, e-government is not possible, unless administrative culture and procedures change.

  5. Development of a new lower hybrid antenna module using a poloidal power divider

    International Nuclear Information System (INIS)

    The antenna using poloidal power divider is an effective method for simplification of Lower Hybrid Current Drive (LHCD) antenna system. This method should allow to reduce the power density in the antenna while maintaining a good flexibility of Nparallel spectrum of waves. For this purpose, three types of poloidal power divider which split the power in three, and the 3 x 6 multi-junction module were developed. r.f. properties and outgassing of these components were evaluated using the CEA Cadarache RF Test Facility. A good power dividing ratio of 33 ± 4% was obtained for each of these poloidal dividers, and the reflection coefficient was lower value than 1.5%. For the 3 x 6 multi-junction, reflection coefficient was less than 1.3% and r.f. losses lower than 1.0% were measured. On the other hand, it was found in the scattering matrix analysis that reflection coefficient at plasma has to be less than a few % in order to operate these components under available conditions. In combination with two poloidal power dividers connected to the 3 x 6 multi-junction module, quasi stationary operation for r.f. injection time of 1000 sec at 300 kW was demonstrated under water cooling. In this case, it was found that the outgassing rate is in the lower range of 10-7Pam3s-1m-2 within the maximum module temperature of ∼100degC. This report describes the experimental and analytical results of a new lower hybrid (LH) antenna module using the poloidal power divider. (author)

  6. Thermosetting polyimide resin matrix composites with interpenetrating polymer networks for precision foil resistor chips based on special mechanical performance requirements

    Energy Technology Data Exchange (ETDEWEB)

    Wang, X.Y., E-mail: wxy@tju.edu.cn [School of Electronic Information Engineering, Tianjin University, Tianjin 300072 (China); Ma, J.X.; Li, C.G. [School of Electronic Information Engineering, Tianjin University, Tianjin 300072 (China); Wang, H.X. [ZHENGHE electronics Co., Ltd, Jining 272023 (China)

    2014-04-01

    Highlights: Macromolecular materials were chosen to modify thermosetting polyimide (TSPI). The formation of IPN structure in TSPI composite polymers was discussed. The special mechanical properties required were the main study object. The desired candidate materials should have proper hardness and toughness. The specific mechanical data are quantitatively determined by experiments. - Abstract: Based on interpenetrating networks (IPNs) different macromolecular materials such as epoxy, phenolic, and silicone resin were chosen to modify thermosetting polyimide (TSPI) resin to solve the lack of performance when used for protecting precision foil resistor chips. Copolymerization modification, controlled at curing stage, was used to prepare TSPI composites considering both performance and process requirements. The mechanical properties related to trimming process were mainly studied due to the special requirements of the regularity of scratch edges caused by a tungsten needle. The analysis on scratch edges reveals that the generation and propagation of microcracks caused by scratching together with crack closure effect may lead to regular scratch traces. Experiments show that the elongation at break of TSPI composites is the main reason that determines the special mechanical properties. The desired candidate materials should have proper hardness and toughness, and the specific mechanical data are that the mean elongation at break and tensile strength of polymer materials are in the range of 9.210.4% and 100107 MPa, respectively. Possible reasons for the effect of the modifiers chosen on TSPI polymers, the reaction mechanisms on modified TSPI resin and the IPN structure in TSPI composite polymers were discussed based on IR and TG analysis.

  7. Thermosetting polyimide resin matrix composites with interpenetrating polymer networks for precision foil resistor chips based on special mechanical performance requirements

    International Nuclear Information System (INIS)

    Highlights: • Macromolecular materials were chosen to modify thermosetting polyimide (TSPI). • The formation of IPN structure in TSPI composite polymers was discussed. • The special mechanical properties required were the main study object. • The desired candidate materials should have proper hardness and toughness. • The specific mechanical data are quantitatively determined by experiments. - Abstract: Based on interpenetrating networks (IPNs) different macromolecular materials such as epoxy, phenolic, and silicone resin were chosen to modify thermosetting polyimide (TSPI) resin to solve the lack of performance when used for protecting precision foil resistor chips. Copolymerization modification, controlled at curing stage, was used to prepare TSPI composites considering both performance and process requirements. The mechanical properties related to trimming process were mainly studied due to the special requirements of the regularity of scratch edges caused by a tungsten needle. The analysis on scratch edges reveals that the generation and propagation of microcracks caused by scratching together with crack closure effect may lead to regular scratch traces. Experiments show that the elongation at break of TSPI composites is the main reason that determines the special mechanical properties. The desired candidate materials should have proper hardness and toughness, and the specific mechanical data are that the mean elongation at break and tensile strength of polymer materials are in the range of 9.2–10.4% and 100–107 MPa, respectively. Possible reasons for the effect of the modifiers chosen on TSPI polymers, the reaction mechanisms on modified TSPI resin and the IPN structure in TSPI composite polymers were discussed based on IR and TG analysis

  8. Transformer-based design techniques for oscillators and frequency dividers

    CERN Document Server

    Luong, Howard Cam

    2016-01-01

    This book provides in-depth coverage of transformer-based design techniques that enable CMOS oscillators and frequency dividers to achieve state-of-the-art performance. Design, optimization, and measured performance of oscillators and frequency dividers for different applications are discussed in detail, focusing on not only ultra-low supply voltage but also ultra-wide frequency tuning range and locking range. This book will be an invaluable reference for anyone working or interested in CMOS radio-frequency or mm-Wave integrated circuits and systems.

  9. Functionals of Exponential Brownian Motion and Divided Differences

    CERN Document Server

    Baxter, Brad

    2010-01-01

    We provide a surprising new application of classical approximation theory to a fundamental asset-pricing model of mathematical finance. Specifically, we calculate an analytic value for the correlation coefficient between exponential Brownian motion and its time average, and we find the use of divided differences greatly elucidates formulae, providing a path to several new results. As applications, we find that this correlation coefficient is always at least $1/\\sqrt{2}$ and, via the Hermite--Genocchi integral relation, demonstrate that all moments of the time average are certain divided differences of the exponential function. We also prove that these moments agree with the somewhat more complex formulae obtained by Oshanin and Yor.

  10. Google and the digital divide the bias of online knowledge

    CERN Document Server

    Segev, Elad

    2010-01-01

    Beneficial to scholars and students in the fields of media and communication, politics and technology, this book outlines the significant role of search engines in general and Google in particular in widening the digital divide between individuals, organisations and states. It uses innovative methods and research approaches to assess and illustrate the digital divide by comparing the popular search queries in Google and Yahoo in different countries as well as analysing the various biases in Google News and Google Earth. The different studies developed and presented in this book provide various

  11. Histological findings of divided muscle after peroral endoscopic myotomy.

    Science.gov (United States)

    Shiwaku, Hironari; Inoue, Haruhiro; Nimura, Satoshi; Yamashita, Kanefumi; Ohmiya, Toshihiro; Takeno, Shinsuke; Sasaki, Takamitsu; Yamashita, Yuichi

    2016-01-01

    Peroral endoscopic myotomy (POEM) is a revolutionary therapy for achalasia and related disorders. POEM utilizes almost the same myotomy procedure as the Heller myotomy; thus, it would be expected to have the same or greater duration of therapeutic effect. However, to date, there have been no reports to prove the basis for this procedure in achalasia. In this case, we were able to histologically show the divided muscle after POEM since the patient had an esophagectomy for esophageal cancer. Histology showed that the muscle tissue divided by the POEM procedure was completely replaced by fibrosis. These findings may indirectly show the permanence of the POEM procedure. PMID:26752956

  12. Symbols and the Divided Self in Janus

    OpenAIRE

    Xiaomi ZHANG

    2014-01-01

    The paper presents the main theme of American writer Ann Beattie’s short novel Janus—the divided self. Illustrations are given here on the symbolic meaning of the mysterious bowl as well as the cold house. The relationship between bowl and love as well as connection between house and marriage reveal the true implication of two-faced god Janus. All the work throws light on the divided self resulted from emptiness, confusion and emotional difficulties of middle and upper-middle class.

  13. Bruce NGS A Unit 4 preheater divider plate failure

    International Nuclear Information System (INIS)

    On May 19, 1995, without any prior operational indications, Bruce A discovered preheater divider plate damage in Unit 4 that had the potential to have a major impact on the continued safe operation of the station. Further investigations indicated that Unit 4 may have been operating with this damage for as long as ten years. In the two months following the discovery, Bruce A has procured and replaced the 4 divider plates, located most of the missing pieces, retrieved pieces from the PHT system, investigated historical operational information, performed detailed analytical investigations, investigated root cause, performed in-situ and mock-up testing, updated operational procedures and installed DP monitoring equipment

  14. Dividing Attention Lowers Children's but Increases Adults' False Memories

    Science.gov (United States)

    Otgaar, Henry; Peters, Maarten; Howe, Mark L.

    2012-01-01

    The present study examined the impact of divided attention on children's and adults' neutral and negative true and false memories in a standard Deese/Roediger-McDermott paradigm. Children (7- and 11-year-olds; n = 126) and adults (n = 52) received 5 neutral and 5 negative Deese/Roediger-McDermott word lists; half of each group also received a…

  15. Radial/Axial Microwave Power Divider/Combiner

    Science.gov (United States)

    Vaddiparty, Verriah P.

    1987-01-01

    Parts made on printed-circuit boards. Impedance-matching and power-dividing transmission-line strips formed on insulation disks and on board by printed-circuit techniques. Power from input transmission line sent equally through radial output conductors to radial output transmission lines and/or coupled in varying degrees to axial output transmission line.

  16. Digital Divide among Youth: Socio-Cultural Factors and Implications

    Science.gov (United States)

    Parycek, Peter; Sachs, Michael; Schossbock, Judith

    2011-01-01

    Purpose: This paper aims to examine socio-cultural differences in internet use (Digital Divide) among 14-year-old Austrian pupils, in particular usage scenarios and research competences. It is based on a paper presented at the International Association for the Development of the Information Society e-Society conference, 10-13 March 2011, Spain…

  17. Peculiarities of the Digital Divide in Sub-Saharan Africa

    Science.gov (United States)

    Mutula, Stephen M.

    2005-01-01

    Purpose: Seeks to argue that the peculiarities of sub-Saharan Africa, in terms of its socio-cultural diversity, low economic development, linguistic factors, HIV/AIDS pandemic, gender discrimination, low ICT awareness and so on, demand a new model of addressing the digital divide. Design/methodology/approach: Paper largely based on literature…

  18. Dividing Genetic Computation Method for Robust Receding Horizon Control Design

    OpenAIRE

    Tohru Kawabe

    2010-01-01

    A new robust Receding Horizon Control (RHC) design approach for the sampled-data systems is proposed. The approach is based on a dividing genetic computation of minimax optimization for a robust finite receding horizon control problem. Numerical example is given to show the effectiveness of the proposed method.

  19. Dividing Attention Lowers Children's but Increases Adults' False Memories

    Science.gov (United States)

    Otgaar, Henry; Peters, Maarten; Howe, Mark L.

    2012-01-01

    The present study examined the impact of divided attention on children's and adults' neutral and negative true and false memories in a standard Deese/Roediger-McDermott paradigm. Children (7- and 11-year-olds; n = 126) and adults (n = 52) received 5 neutral and 5 negative Deese/Roediger-McDermott word lists; half of each group also received a

  20. Crossing Anxious Borders: Teaching across the Quantitative--Qualitative "Divide"

    Science.gov (United States)

    Luttrell, Wendy

    2005-01-01

    This paper is about teaching and learning across the so-called quantitative-qualitative divide in light of current debates in the US about the definition and quality of educational research. It draws on the author's research and teaching experiences, her role in the redesign of qualitative methods coursework and participation in a school-wide…

  1. The Digital Divide and Its Impact on Academic Performance

    Science.gov (United States)

    Sun, Jerry Chih-Yuan; Metros, Susan E.

    2011-01-01

    The purpose of this article is to explore issues of the digital divide and its impact on academic performance. Research shows that proper use of technology by students increases their academic performance outcomes. In the literature review section, the authors review articles and theories based on Bennett's (2001) societal equity framework. The…

  2. Peculiarities of the Digital Divide in Sub-Saharan Africa

    Science.gov (United States)

    Mutula, Stephen M.

    2005-01-01

    Purpose: Seeks to argue that the peculiarities of sub-Saharan Africa, in terms of its socio-cultural diversity, low economic development, linguistic factors, HIV/AIDS pandemic, gender discrimination, low ICT awareness and so on, demand a new model of addressing the digital divide. Design/methodology/approach: Paper largely based on literature

  3. New Literacies at the Digital Divide: American Indian Community Computing

    Science.gov (United States)

    Betts, J. David

    2009-01-01

    This study is about a community computing lab established by a U.S. Department of Commerce grant to bridge the Digital Divide in a rural Arizona American Indian community, a project called "Native Connection" (a pseudonym). This paper describes the process of integrating new literacies associated with a high-tech computer lab into the life of a

  4. Journalism Students, Web 2.0 and the Digital Divide

    Science.gov (United States)

    Green, Mary Elizabeth

    2009-01-01

    The purpose of this study was to find out if students were utilizing Web 2.0 applications. Since the applications in question are often employed by the media industry, the study aspired to find out if students majoring in mass communication and journalism utilized the applications more often than other students. The "digital divide" is a term used

  5. Digital Divide among Youth: Socio-Cultural Factors and Implications

    Science.gov (United States)

    Parycek, Peter; Sachs, Michael; Schossbock, Judith

    2011-01-01

    Purpose: This paper aims to examine socio-cultural differences in internet use (Digital Divide) among 14-year-old Austrian pupils, in particular usage scenarios and research competences. It is based on a paper presented at the International Association for the Development of the Information Society e-Society conference, 10-13 March 2011, Spain

  6. Second-Level Digital Divide: Differences in People's Online Skills.

    Science.gov (United States)

    Hargittai, Eszter

    2002-01-01

    Discussion of the digital divide in access to the Internet focuses on differences in people's online skills and therefore access to information based on age, gender, and technology experience. Findings suggest wide differences in search strategies, ability to find various types of content, and how long it takes. Demographics of respondents are

  7. The Digital Divide and Rural Community Colleges: Problems and Prospects.

    Science.gov (United States)

    Katsinas, Stephen G.; Moeck, Pat

    2002-01-01

    Discusses the seriousness of the digital divide-the discrepancy between technology-literate and -illiterate people-in rural areas in the United States. Reports that rural young, minority, and single-parent households lag behind the national average in both personal computer ownership and Internet access. Offers suggestions for ways rural community

  8. Water

    Science.gov (United States)

    ... environment and your health: Green living Sun Water Health effects of water pollution How to protect yourself from water pollution Air Chemicals Noise Quizzes Links to more information girlshealth ...

  9. Advanced on-chip divider for monolithic microwave VCO's

    Science.gov (United States)

    Peterson, Weddell C.

    1989-01-01

    High frequency division on a monolithic circuit is a critical technology required to significantly enhance the performance of microwave and millimeter-wave phase-locked sources. The approach used to meet this need is to apply circuit design practices which are essentially 'microwave' in nature to the basically 'digital' problem of high speed division. Following investigation of several promising circuit approaches, program phase 1 culminated in the design and layout of an 8.5 GHz (Deep Space Channel 14) divide by four circuit based on a dynamic mixing divider circuit approach. Therefore, during program phase 2, an 8.5 GHz VCO with an integral divider which provides a phase coherent 2.125 GHz reference signal for phase locking applications was fabricated and optimized. Complete phase locked operation of the monolithic GaAs devices (VCO, power splitter, and dynamic divider) was demonstrated both individually and as an integrated unit. The fully functional integrated unit in a suitable test fixture was delivered to NASA for engineering data correlation. Based on the experience gained from this 8.5 GHz super component, a monolithic GaAs millimeter-wave dynamic divider for operation with an external VCO was also designed, fabricated, and characterized. This circuit, which was also delivered to NASA, demonstrated coherent division by four at an input frequency of 24.3 GHz. The high performance monolithic microwave VCO with a coherent low frequency reference output described in this report and others based on this technology will greatly benefit advanced communications systems in both the DoD and commercial sectors. Signal processing and instrumentation systems based on phase-locking loops will also attain enhanced performance at potentially reduced cost.

  10. Area and Power Optimization of Flexible Multiband Divider

    Directory of Open Access Journals (Sweden)

    R.Naveenkumar

    2013-12-01

    Full Text Available The demand for lower cost, lower power, and multiband RF circuits increased in conjunction with need of higher level of integration. In this project a low-power single-phase clock multiband flexible divider for Bluetooth, Zigbee, and Network standard’s 802.15.4 and 802.11 a/b/g Wireless LAN frequency synthesizers is proposed based on pulse-swallow topology and is implemented. The frequency synthesizer, usually implemented by a phase-locked loop (PLL, is one of the power-hungry blocks in the RF front-end and the first-stage frequency divider consumes a large portion of power in a frequency synthesizer. The proposed prescaler based approach reduces the area and power significantly. The multiband divider consists of a proposed wideband multi modulus 32/33/47/48 prescaler and an improved bit-cell for swallow (S counter and can divide the frequencies in the three bands of 2.41–2.483 GHz, 5.14–5.30 GHz, and 5.715–5.815 GHz with a resolution selectable from 1 to 25 MHz The proposed multiband flexible divider is silicon verified and consumes power of 0.96 and 2.2 mw in 2.3-and 5-GHz bands, respectively, when operated at 1.8-V power supply. The proposed prescaler is achieved by without using any additional flip flops. It gives a solution to the low power PLL synthesizers for wide range of communication applications.

  11. Plasma Sprayed Resistors

    OpenAIRE

    J. C. Anderson; Smith, D. P. H.

    1980-01-01

    A range of films of mixed composition, prepared by arc plasma spraying, has been investigated. Both free powder and powder in a plastic binder forming a rod have been used in the spray process. A variety of mixtures of insulators, metals and semiconductors has been examined and it is shown that resistivity/temperature curves for the specimens produced have in general two points of inflection, the temperatures of which vary with composition. This allows prediction of a composition giving low T...

  12. A new mechanism to cross the phantom divide

    CERN Document Server

    Du, Yunshuang; Li, Xin-Zhou

    2010-01-01

    Recently, type Ia supernovae data appear to support a dark energy whose equation of state $w$ crosses $-1$, which is a much more amazing problem than the acceleration of the universe. We show that it is possible for the equation of state to cross the phantom divide by only a single scalar field in the gravity with an additional inverse power-law term of Ricci scalar in the Lagrangian. The necessary and sufficient condition for a universe in which the dark energy can cross the phantom divide is obtained. Some analytical solutions with $w-1$ are obtained. A minimal coupled scalar with different potentials, including quadratic, cubic, quantic, exponential and logarithmic potentials are investigated via numerical methods, respectively. All these potentials lead to the crossing behavior. We show that it is a general geometric result which is independent on the concrete form of the potential of the scalar.

  13. Darwinism Then and Now: The Divide Over Form and Function

    Science.gov (United States)

    Ruse, Michael

    2010-05-01

    As biologists have recognized since Aristotle, there are two complementary ways of looking at organisms: one can think of them from the viewpoint of homology, asking about the isomorphisms between different organisms and even within the organisms themselves; or one can think of them from the viewpoint of adaptation or final cause, asking about the ends that the features serve. I look at this divide with special respect to the theory of evolution through natural selection as first announced by the English naturalist Charles Darwin in his Origin of Species in 1859, considering both different interpretations that scholars today make of Darwins work and the overall implications of Darwins achievements for the homology/adaptation, often called the form/function, divide.

  14. The cultural divide: exploring communication barriers between scientists and clinicians.

    Science.gov (United States)

    Restifo, Linda L; Phelan, Gerald R

    2011-07-01

    Despite remarkable advances in basic biomedical science that have led to improved patient care, there is a wide and persistent gap in the abilities of researchers and clinicians to understand and appreciate each other. In this Editorial, the authors, a scientist and a clinician, discuss the rift between practitioners of laboratory research and clinical medicine. Using their first-hand experience and numerous interviews throughout the United States, they explore the causes of this 'cultural divide'. Members of both professions use advanced problem-solving skills and typically embark on their career paths with a deeply felt sense of purpose. Nonetheless, differences in classroom education, professional training environments, reward mechanisms and sources of drive contribute to obstacles that inhibit communication, mutual respect and productive collaboration. More than a sociological curiosity, the cultural divide is a significant barrier to the bench-to-bedside goals of translational medicine. Understanding its roots is the first step towards bridging the gap. PMID:21708897

  15. SIW based multilayer transition and power divider in LTCC technology

    KAUST Repository

    Abuzaid, Hattan

    2013-06-01

    A multilayer transition and balanced power divider are presented for millimeter-wave system-on-package (SoP). These two components operate at Ka-band and exploit the substrate integrate waveguide (SIW) technology with its shielding characteristics and the Low-temperature co-fired ceramics (LTCC) technology for its high density integration. A coupling slot has been used to perform vertical integration, which can be easily optimized through its length. The measured input return loss within the bandwidth of interest (32 GHz-38 GHz) is less than -15 dB and -18 dB for the multilayer transition and the power divider, respectively. The lateral dimensions of a multilayer system, such as a feed network of an array, can be greatly reduced by employing these 3D slot-coupled components. © 2013 IEEE.

  16. Ecuador, the Digital Divide and Small Tourism Enterprises

    Directory of Open Access Journals (Sweden)

    Stan Karanasios

    2014-09-01

    Full Text Available This article explores the digital divide from the perspective of Ecuadorian small tourism enterprises. Ecuador’s ICT environment has been described as underdeveloped, obsolete, and expensive to use. There is also a serious shortage of ICT related human capital. Given these stumbling blocks, this article seeks to identify how small tourism operators have managed to adopt the Internet. Adopting a qualitative approach, field interviews were conducted with tourism enterprises across rural, semi-rural, and metropolitan areas of Ecuador. This article adds to our understanding of the digital divide, especially from the point of view of small tourism enterprises, and serves as an example to other small tourism enterprises in developing countries seeking to adopt the Internet.

  17. Hybrid songbirds employ intermediate routes in a migratory divide.

    Science.gov (United States)

    Delmore, Kira E; Irwin, Darren E

    2014-10-01

    Migratory divides are contact zones between populations that use different routes to navigate around unsuitable areas on seasonal migration. Hybrids in divides have been predicted to employ intermediate and potentially inferior routes. We provide the first direct test of this hypothesis, using light-level geolocators to track birds breeding in a hybrid zone between Swainson's thrushes in western Canada. Compared to parental forms, hybrids exhibited increased variability in their migratory routes, with some using intermediate routes that crossed arid and mountainous regions, and some using the same routes as one parental group on fall migration and the other on spring migration. Hybrids also tended to use geographically intermediate wintering sites. Analysis of genetic variation across the hybrid zone suggests moderately strong selection against hybrids. These results indicate that seasonal migratory behaviour might be a source of selection against hybrids, supporting a possible role for migration in speciation. PMID:25040456

  18. THE DIGITAL DIVIDE PROFILE OF GREECE: ONE STEP FURTHER

    OpenAIRE

    Georgopoulou, Panagiota

    2011-01-01

    The issue of "digital divide" as a new form of social inequality regarding the access to and use of information and communication technologies (ICTs) has not yet received substantial attention in contemporary policy and social debate in Greece. Most of the research has taken place within the framework of the "Observatory for the Greek information society" supported by the EU and established as part of EU-funded initiatives concerning the promotion of the "Information Society" within European ...

  19. Reconstituting the Public-Private Divide under Global Conditions

    OpenAIRE

    Dicke, Willemijn; Albrow, Martin

    2005-01-01

    Abstract How is the line to be drawn in the public-private divide when those who would bridge it also assert that globalization restricts the state?s ability to deliver public policy objectives? Critics of modernity have seen the distinction between two public-private discourses, state and market, the open and the hidden, as a modern flawed version of classic notions of the democratic citizen community. The...

  20. Unequal-Split Strip-Line Power Divider

    Science.gov (United States)

    Bailey, M. C.

    1982-01-01

    Simple technique for designing strip-line or microstrip power dividers can be used for unequal, but inphase power split. Technique allows power splits ranging from equal to as large as required, with advantage of using same line impedances and line spacings for all splits. Output power ratio is determined by selecting location of input port in manner analogous to tap point for electric-power transformer.

  1. Compact high-power microwave divider and combiner

    Science.gov (United States)

    Guo, L. T.; Chang, C.; Huang, W. H.; Liu, Y. S.; Cao, Y. B.; Liu, C. L.; Sun, J.

    2016-02-01

    A novel, compact, TM01-TE10 mode power divider and a novel, compact, four-way TE10-TM01 mode power combiner were theoretically designed and experimentally tested as a proof of principle. The theoretical and experimental S parameters are consistent with each other. High-power experiments show that their power capacities are no less than 1.5 GW and 3 GW, respectively. The devices have the merits of high power capacities and low insertion losses.

  2. Internet fr alle? Die Diskussion des digital divide revisited

    OpenAIRE

    Krings, Bettina; Riehm, Ulrich

    2006-01-01

    Die Diskussion um das digital divide oder die digitale Spaltung, wie sie fr den deutschsprachigen Raum bersetzt wird, wird nun schon seit nahezu zehn Jahren intensiv gefhrt.1 Vor allem im Rahmen der politischen Diskussion hat sich das Bedrohungsszenario einer digitalen Spaltung innerhalb der Gesellschaften festgesetzt. Aber auch weite Teile der wissenschaftlichen Debatte haben dieses Szenario aufgegriffen und aus unterschiedlichen Perspektiven beleuchtet und analysiert. Obgleich sich di...

  3. Divided Dreamworlds? : The Cultural Cold War in East and West

    OpenAIRE

    Romijn, Peter,; Scott-Smith, Giles; Segal, Joes

    2012-01-01

    While the divide between capitalism and communism, embodied in the image of the Iron Curtain, seemed to be as wide and definitive as any cultural rift, Giles Scott-Smith, Joes Segal, and Peter Romijn have compiled a selection of essays on how culture contributed to the blurring of ideological boundaries between the East and the West. This important and diverse volume presents fascinating insights into the tensions, rivalries, and occasional cooperation between the two blocs, with essays that ...

  4. Bridging the Rural - Urban Digital Divide in Residential Internet Access

    OpenAIRE

    Whitacre, Brian E.

    2005-01-01

    This dissertation explores the persistent gap between rural and urban areas in the percentage of households that access the Internet at home (a discrepancy commonly known as the "digital divide"). The theoretical framework underlying a household's Internet adoption decision is examined, with emphasis on the roles that household characteristics, network externalities, and digital communication technology (DCT) infrastructure potentially play. This framework is transferred into a statistical ...

  5. Pseudodifference operators and uniform convergence of divided differences

    International Nuclear Information System (INIS)

    The concept of pseudodifference operator is introduced. The properties of a class of pseudodifference operators in spaces of fractional quotients are studied. A local theorem on the uniform convergence of divided differences of arbitrary order for an approximate solution is established. In particular, the local infinite differentiability of a precise solution of operator equations of elliptic type with locally infinitely differentiable right-hand side is proved on the basis of a numerical method. Examples related to applications are presented

  6. Sharp van der Corput estimates and minimal divided differences

    OpenAIRE

    Rogers, Keith

    2003-01-01

    We find the nodes that minimise divided differences and use them to find the sharp constant in a sublevel set estimate. We also find the sharp constant in the first instance of the van der Corput Lemma using a complex mean value theorem for integrals. With these sharp bounds we improve the constant in the general van der Corput Lemma, so that it is asymptotically sharp.

  7. Bridging the Digital Divide: Enhancing Empowerment and Social Capital

    OpenAIRE

    Diane Marie Charleson

    2012-01-01

    In the contemporary world, the digital divide constitutes a significant inequality and thus poses a very real problem of social justice this being particularly the case for those already burdened with disadvantage and marginalisation. In this paper, As part of its commitment to Social Justice the Australian Catholic University runs a Catalyst Clemente program. Catalyst-Clemente provides people experiencing multiple disadvantage with university level education by means of a program that aims...

  8. Is the digital divide between young and elderly people increasing?

    OpenAIRE

    Paul, Gerd; Stegbauer, Christian

    2005-01-01

    Elderly people still play a minor role in research on information needs and usage patterns of Internet users. Online research and advocacy groups look optimistically at the (economic and social) potential of the active and technologyskilled elderly; other approaches dealing with the social appropriation of technology see obstacles and stress the dangers of an increasing digital divide between generations. Our objective is to refer to taken for granted normative assumptions of the digital div...

  9. From digital divides to digital entitlements in knowledge societies

    OpenAIRE

    Mansell, Robin

    2002-01-01

    This paper critically examines current constructions of the causes, consequences and appropriate actions to reduce the so-called 'digital divide'. Drawing upon discussions that have occurred in a number of intergovernmental forums, the analysis illustrates the limitations of policy debates that focus primarily on issues of access, affordability and capabilities and skills for employability in industry. An alternative framework for assessing the unfolding relation between the new media and soc...

  10. An Efficient Divide-and-Conquer Algorithm for Morphological Filters

    OpenAIRE

    Lou, Shan; Jiang, Xiangqian; Scott, Paul J

    2013-01-01

    Morphological filters, evolved from the traditional envelope filter, are function oriented filtration techniques. A recent research on the implementation of morphological filters was based on the theoretical link between morphological operations and the alpha shape. However the Delaunay triangulation on which the alpha shape method depends is costly for large areal data. This paper proposes a divide-and-conquer method as an optimization to the alpha shape method aiming to speed up its perfor...

  11. BRIDGING THE KNOWLEDGE DIVIDE Educational Technology for Development

    OpenAIRE

    Reviewed by Ozlem OZAN,

    2009-01-01

    BRIDGING THE KNOWLEDGE DIVIDEEducational Technology for DevelopmentMarshall,S., Kinuthia, W. & Wallace Taylor., Ed.D.; Information Age Publishing, Charlotte, NC, SBN: 978-1-60752-109-9, p.433, 2009Reviewed by Ozlem OZANFaculty of EducationEski?ehir Osmangazi UniversityEskisehir, TURKEYThe concept of a knowledge divide is used to describe the gap in living conditions between those who can find, manage and process information or knowledge, and those who are impaired in this, for one reason or a...

  12. Divided-pulse amplification for terawatt-class fiber lasers

    OpenAIRE

    Eidam, T.; Kienel, M.; Klenke, A.; Limpert, J.; Tnnermann, A

    2015-01-01

    The coherent combination of ultra short laser pulses is a promising approach for scaling the average and peak power of ultrafast lasers. Fiber lasers and amplifiers are especially suited for this technique due to their simple singe-pass setups that can be easily parallelized. Here we propose the combination of the well-known approach of spatially separated amplification with the technique of divided-pulse amplification, i.e. an additionally performed temporally separated amplification. With t...

  13. Asset Dividing Appraisal Model (ADAM) - Direct Real Estate Investment Evaluation

    OpenAIRE

    Schäfer, Carsten

    2012-01-01

    The Asset Dividing Appraisal Model (ADAM) enables the appraisal of cash flows resulting from direct real estate investments. The model is an evaluation tool, which takes capital markets and the specific characteristics of real estate as an asset (heterogeneity, site-dependency, eternal land-yield, etc.) into consideration, while also considering different ownership approaches of real estate in the European Union. Thus, it contributes to the harmonization of capital markets and of direct real ...

  14. Dividing Streamline Formation Channel Confluences by Physical Modeling

    Directory of Open Access Journals (Sweden)

    Minarni Nur Trilita

    2010-02-01

    Full Text Available Confluence channels are often found in open channel network system and is the most important element. The incoming flow from the branch channel to the main cause various forms and cause vortex flow. Phenomenon can cause erosion of the side wall of the channel, the bed channel scour and sedimentation in the downstream confluence channel. To control these problems needed research into the current width of the branch channel. The incoming flow from the branch channel to the main channel flow bounded by a line distributors (dividing streamline. In this paper, the wide dividing streamline observed in the laboratory using a physical model of two open channels, a square that formed an angle of 30º. Observations were made with a variety of flow coming from each channel. The results obtained in the laboratory observation that the width of dividing streamline flow is influenced by the discharge ratio between the channel branch with the main channel. While the results of a comparison with previous studies showing that the observation in the laboratory is smaller than the results of previous research.

  15. THE DIGITAL DIVIDE: ICT DEVELOPMENT INDICES IN MEXICO

    Directory of Open Access Journals (Sweden)

    Edgar TELLO-LEAL

    2012-01-01

    Full Text Available The integration of Information and Communication Technologies (ICTs to the manufacturing sector enables to reduce production, management and marketing costs, allowing achieve higher levels of competitiveness. In the social area, ICTs are tools of inclusion improving the provision of education, health and government services, as well as expanding its coverage area of these services. To achieve these benefits it is required a proper incorporation and adaptation of ICTs in the social area, as well as, the development of required ICT services, properly. In this work, we analyze the role of the digital divide in the information society, as ground for social exclusion in the use of ICT in Mexico. Afterwards, the behavior of the digital divide is analyzed, with its different dimensions through time, also describing the penetration and development levels of ICT. Moreover, the case of study of university students enrolled in Information Technology careers is discussed in order to determine the existence of a digital divide and its parameters. Finally, a diagnosis about the growth of the Internet and mobile telephony services in Mexico is carried out, considering the prevailing world economic situation.

  16. Rivers as borders, uniting or dividing? The effect of topography and implications for catchment management.

    Science.gov (United States)

    Smedley, D A; Rowntree, K M

    2012-01-01

    South Africa's water resources are unequally distributed over space and time and an already stressed water resource situation will only be exacerbated by climate change if current predictions are correct. The potential for conflict over increasingly strained water resources in South Africa is thus very real. In order to deal with these complex problems, national legislation is demanding that water resource management be decentralized to the local level where active participation can take place in an integrated manner in accordance with the principles of Integrated Water Resource Management (IWRM). However, administrative and political boundaries rarely match those of catchments as, throughout South Africa, rivers have been employed extensively to delineate administrative and political boundaries at a number of spatial scales. The aim of this research is to determine if rivers act as dividing or uniting features in a socio-political landscape and whether topography will influence their role in this context. The Orange-Senqu River is used as a case study. This paper goes on to consider the implications of this for catchment management in South Africa. No study known to the authors has explored the effect of the river itself, and its topographic setting, on the drivers that foster either conflict or cooperation, and allow for participatory management. This study presents evidence that the topography of a catchment has the ability to aggravate or reduce the impact of the variables considered by water managers and thereby influence the role of a river as a dividing or uniting feature. South Africa's proposed form of decentralized water management will have to contend with the effects of different topographies on the way in which rivers are perceived and utilized. PMID:22744680

  17. Effect of the Addition of Different Metal Oxides in Lead Borosilicate Glasses on the Electrical Characteristics of SbSn Composition-Based Thick-Film Resistors

    OpenAIRE

    R. N. Karekar; G. N. Natu; Cubellio, E. R.; R. C. Aiyer

    1993-01-01

    The paper reports the effect of addition of metal oxides in lead borosilicate glasses on electrical characteristics of SbSn alloy-based thick-film resistors. The Sb and Sn powder (1: 1 by weight) is taken in two quartz tubes separately, vacuum sealed at 10–5 Torr and heated in a resistive furnace .at 430℃ and 630℃ respectively. The conventional glass [1] is modified by using different dopants like tungsten oxide, cobalt oxide, lithium oxide, titanium dioxide, venadium pentoxide, chromium oxid...

  18. Water

    International Nuclear Information System (INIS)

    An up-date overview of the situation of the Austrian waters is given by analyzing the status of the water quality (groundwater, surface waters) and water protection measures. Maps containing information of nitrate and atrazine in groundwaters (analyses at monitoring stations), nitrate contents and biological water quality of running waters are included. Finally, pollutants (nitrate, orthophosphate, ammonium, nitrite, atrazine etc.) trends in annual mean values and median values for the whole country for the years 1992-1999 are presented in tables. Figs. 5. (nevyjel)

  19. Preferential processing of tactile events under conditions of divided attention: Effects of divided attention on reaction time

    OpenAIRE

    Hanson, James V. M.; Whitaker, David; Heron, James

    2009-01-01

    Differences in transduction and transmission latencies of visual, auditory and tactile events cause corresponding differences in simple reaction time. As reaction time is usually measured in unimodal blocks, it is unclear whether such latency differences also apply when observers monitor multiple sensory channels. We investigate this by comparing reaction time when attention is focussed on a single modality, and when attention is divided between multiple modalities. Results show that tactile ...

  20. Wireless Technologies Bridging the Digital Divide in Education

    Directory of Open Access Journals (Sweden)

    Gerard Smyth

    2006-06-01

    Full Text Available The objective of this paper is to demonstrate how the latest wireless standards and technologies may overcome the digital divide in education in the developed and developing worlds. The concept of the digital divide is discussed in the traditional socio-economic sense and expanded in terms of the learner's location, age, culture and background. It is important that we understand the full extent and complexities of this division if we are to effectively bridge it. Why and how the digital divide may be bridged is examined. Apart from the inherent inequalities that need to be addressed from an ethical perspective, it is very much in the interests of governments and citizens globally that Information and Communications Technology (ICT is made available to all as quickly and cost-effectively as possible. New forms of wireless protocols are overcoming challenges of terrain, infrastructure and finance. It is proposed that, by leveraging open broadband wireless standards, like Wireless Fidelity (Wi-Fi* and Worldwide Interoperability for Microwave Access (WiMAX*, and implementing Mobile Computing architecture, it is now possible to make dramatic strides in this direction. The paper continues with a general overview of these wireless standards and technologies followed by an in-depth look at Wi-Fi and WiMAX. The paper goes on to give examples of the Innovation Centre's involvement in delivering solutions and new usage models for eLearning that utilize the latest wireless standards and technologies. The challenges and successes of these projects are outlined and metrics are presented where available.

  1. Surface Tension and Adsorption without a Dividing Surface.

    Science.gov (United States)

    Marmur, Abraham

    2015-11-24

    The ingenious concept of a dividing surface of zero thickness that was introduced by Gibbs is the basis of the theory of surface tension and adsorption. However, some fundamental questions, mainly those related to the location of the dividing surface and the proper definition of relative adsorption, have remained open over the years. To avoid these questions, the present paper proposes to analyze an interfacial phase by defining a thermodynamic system of constant, but nonzero thickness. The interfacial phase is analyzed as it really is, namely a nonuniform three-dimensional entity. The current analysis redevelops the equation for calculating surface tension, though with different assumptions. However, the main point in the proposed model is that the thermodynamic interfacial system, due to its fixed thickness, conforms to the requirement of first-order homogeneity of the internal energy. This property is the key that allows using the Gibbs adsorption isotherm. It is also characteristic of the Gibbs dividing surface model, but has not always been discussed with regard to subsequent models. The resulting equation leads to a simple, "natural" expression for the relative adsorption. This expression may be compared with simulations and sophisticated surface concentration measurements, and from which the dependence of interfacial tension on the solution composition can be derived. Finally, it is important to point out that in order to calculate the interfacial tension as well as the relative adsorption from data on the properties of the interfacial phase, there is no need to know its exact thickness, as long as it is bigger than the actual thickness but sufficiently small. PMID:26523466

  2. Traffic Prediction Based on SVM Training Sample Divided by Time

    Directory of Open Access Journals (Sweden)

    Lingli Li

    2013-07-01

    Full Text Available In recent years, the volume of traffic is rapidly increasing. When vehicles running through the tunnel are more intensive or move slowly, the tunnel environment occurs deteriorated sharply, which affects the normal operation of the vehicle in the tunnel. This paper uses the result of previous mining association rules to select feature items and to establish four training samples divided by time. Then the training samples are utilized to create the SVM classification model. Finally the trained SVM model is used to prediction the tunnel traffic situation. Through traffic situation prediction, effective decisions can be made before traffic jams, and ensure that the tunnel traffic is normal.  

  3. Digital Television, Convergence, and the Public: Another Digital Divide?

    Directory of Open Access Journals (Sweden)

    Jason Smith

    2009-06-01

    Full Text Available While 85 percent of Americans pay to receive television signals through satellite or cable companies, 15 percent still receive their television using over-the-air signals. With the elminination of analog television signals, the 15 percent of households have had to make significant changes in their viewing technology. These households tend to be elderly, poor, minority and rural. Signal coverage areas will be cut back, since government assumed a viewer would have an antenna on a 30 foot pole. Few do, and governmental programs delibertely hid this engineering fact. It is argued that digitalism has neglected the public use of the airways and created yet one more digital divide.

  4. Pump tank divider plate for sump suction sodium pumps

    International Nuclear Information System (INIS)

    A circular plate extends across the diameter of a sump suction pump, with a close clearance between the edge of the plate and the wall of the pump tank. The plate is located above the pump impeller, inlet and outlet flow nozzles but below the sodium free surface and effectively divides the pump tank into two separate chambers. On change of pump speed, the close fitting flow restriction plate limits the rate of flow into or out of the upper chamber, thereby minimizing the rate of level change in the tank and permitting time for the pump cover gas pressure to be varied to maintain an essentially constant level. 4 claims, 3 figures

  5. Affinity and Hostility in Divided Communities: a Mathematical Model

    CERN Document Server

    Thron, Christopher

    2015-01-01

    We propose, develop, and analyze a mathematical model of intergroup attitudes in a community that is divided between two distinct social groups (which may be distinguished by religion, ethnicity, or some other socially distinguishing factor). The model is based on very simple premises that are both intuitive and justified by sociological research. We investigate the behavior of the model in various special cases, for various model configurations. We discuss the stability of the model, and the continuous or discontinuous dependence of model behavior on various parameters. Finally, we discuss possible implications for strategies to improve intergroup affinity, and to defuse tension and prevent deterioration of intergroup relationships.

  6. Divide and be different: Priestly identity in the Persian period

    OpenAIRE

    Esias E. Meyer

    2012-01-01

    The article focused on the Hebrew root לדב [divide] [bdl] in Priestly and post-Priestly material of the Pentateuch. In Genesis 1 God is the subject of the verb and often enough in the Holiness Code, but in many instances in Leviticus (e.g. 10:10 and 11:47) it is expected of priests to perform the same act. It was argued that in this regard priests were to imitate God. The article further argued that these texts helped us to describe Jewish identity in the Persian period as an identity of...

  7. Divide by 4 the emissions: the Negatep scenario

    International Nuclear Information System (INIS)

    The Negatep scenario is proposed in the framework of the french energy policy, aiming to divide by 4 the CO2 emissions for 2050. After an evaluation of the today situation concerning the energy consumption and needs, the scenario proposes some ways of energy conservation in different sectors, other energy sources in place of the fossil fuels, the energy needs by sectors. The last part of the document provides the main consumption posts, the CO2 releases and the approach. (A.L.B.)

  8. Learnings from investigations on SG divider plates: Coupling field characterizations with numerical mechanical simulation

    International Nuclear Information System (INIS)

    Nickel based alloys stress corrosion cracking (SCC) has been a major concern for the nuclear power plant utilities since the 1970s. Since 2002, SCC indications have been found on steam generator (SG) divider plates made of alloy 600 on French PWRs (pressurized water reactors) 900 MWe units. Although integrity is not questioned, many studies have been conducted to deepen understanding of the phenomenon. Among numerous studies to investigate the SCC damage phenomena, advanced mechanical analysis has been performed to improve the knowledge of the in-service loadings of the SG 900 MWe partition stub and divider plate. Manufacturing steps are taken into account, such as welding and the first hydro-test, to have a more precise description of the mechanical states in the vicinity of the welds where SCC is likely to occur. Recently, EDF hot laboratories made destructive examinations of a decommissioned SG. To fulfil the analyses computations have been carried out on the dedicated configuration. A 3D FE model, including the simulation of the welding and hydro-test, has been set up. Comparisons with experimental investigations on the divider plate of decommissioned SG have shown a good agreement between experimental and numerical results. These results emphasize the redistribution of weld residual stresses after the first hydro-test, and the effect of hydro-testing on the plastic deformation of the stub only in some specific cases of 900 MWe SG

  9. On a nonlinear Kalman filter with simplified divided difference approximation

    KAUST Repository

    Luo, Xiaodong

    2012-03-01

    We present a new ensemble-based approach that handles nonlinearity based on a simplified divided difference approximation through Stirling\\'s interpolation formula, which is hence called the simplified divided difference filter (sDDF). The sDDF uses Stirling\\'s interpolation formula to evaluate the statistics of the background ensemble during the prediction step, while at the filtering step the sDDF employs the formulae in an ensemble square root filter (EnSRF) to update the background to the analysis. In this sense, the sDDF is a hybrid of Stirling\\'s interpolation formula and the EnSRF method, while the computational cost of the sDDF is less than that of the EnSRF. Numerical comparison between the sDDF and the EnSRF, with the ensemble transform Kalman filter (ETKF) as the representative, is conducted. The experiment results suggest that the sDDF outperforms the ETKF with a relatively large ensemble size, and thus is a good candidate for data assimilation in systems with moderate dimensions. © 2011 Elsevier B.V. All rights reserved.

  10. Revolutions in Global Networking and Collaborations, and the Digital Divide

    Science.gov (United States)

    Newman, Harvey

    2007-04-01

    The major physics experiments of the next twenty five years, such as those at the Large Hadron Collider and the International Linear Collider, will break new ground in our understanding of the fundamental interactions, structures and symmetries that govern the nature of matter and spacetime. In order to realize the scientific wealth of these experimental programs, physicists have formed global-scale collaborations and built grid systems where the data is processed, distributed and collaboratively analyzed using networked computing facilities at more than 100 sites around the world. Effective use of these emerging ensembles of facilities and networks presents new challenges in Petabyte-scale data access, processing and distribution, and collaboration across national and international networks on a scale unprecedented in the history of science. The key to meeting these challenges is the effective use of data networks. The bandwidth use by high energy physicists, paralleled by scientists in other fields of data intensive science, continues to grow at several hundred times per decade, and there are indications that this growth is accelerating. This is helping to drive the growth of the major networks serving research and education, as well as mission-oriented networks in the US, Europe, Asia-Pacific, Latin America and across the Atlantic and Pacific oceans. Physicists and computer scientists have together made striking technological advances in recent years, and have developed tools that allow full use of long range 10 gigabit/sec links on a routine basis for the first time. As the science community continues to advance in its development of networks and grid systems, a key concern is the rising Digital Divide between the favored and less-favored regions of the world. Closing the Divide is vital for the health of our global collaborations and our field. In this talk I will review these trends, and focus on the means to reduce the Digital Divide, from the perspective of the Standing Committee on Inter-regional Connectivity of the International Committee on Future Accelerators.

  11. Water

    OpenAIRE

    Hertie School of Governance

    2010-01-01

    All human life depends on water and air. The sustainable management of both is a major challenge for today's public policy makers. This issue of Schlossplatz³ taps the streams and flows of the current debate on the right water governance.

  12. Divided-pulse nonlinear amplification and simultaneous compression

    International Nuclear Information System (INIS)

    We report on a fiber laser system delivering 122 fs pulse duration and 600 mW average power at 1560 nm by the interplay between divided pulse amplification and nonlinear pulse compression. A small-core double-clad erbium-doped fiber with anomalous dispersion carries out the pulse amplification and simultaneously compresses the laser pulses such that a separate compressor is no longer necessary. A numeric simulation reveals the existence of an optimum fiber length for producing transform-limited pulses. Furthermore, frequency doubling to 780 nm with 240 mW average power and 98 fs pulse duration is achieved by using a periodically poled lithium niobate crystal at room temperature

  13. Bifurcation in asymmetric plasma divided by a magnetic filter

    International Nuclear Information System (INIS)

    A magnetic filter (MF) reflecting electrons from both sides can separate a low-temperature and low-density subplasma from a high-temperature and high-density main plasma. The one-dimensional numerical simulation by the particle-in-cell code revealed that, depending on the asymmetry, the plasma divided by the MF behaves dynamically or statically [K. Ohi et al., Physics of Plasmas 8, 23 (2001)]. The transition between the two bifurcated states is discontinuous. In the dynamic state, the autonomous potential oscillation in the subplasma is synchronized with the passage of the shock wave structure generated by the modulated ion beam from the main plasma. The stationary phase of the dynamic state appears after the amplitude of the potential oscillation in the subplasma grows exponentially from the thermal noise. In the static state, the system is stable to the growth of the potential oscillation in the subplasma. (author)

  14. Dividing the Janus vasculitis? Pathophysiology of eosinophilic granulomatosis with polyangitis.

    Science.gov (United States)

    Chaigne, Benjamin; Terrier, Benjamin; Thieblemont, Nathalie; Witko-Sarsat, Véronique; Mouthon, Luc

    2016-02-01

    Eosinophilic granulomatosis with polyangitis (EGPA) is a rare small- and medium-sized vessel vasculitis belonging to the group of anti-neutrophil cytoplasm antibody (ANCA)-associated vasculitides (AAV). It is commonly divided into two phenotypes depending on the presence of ANCAs targeting myeloperoxidase (MPO). MPO-ANCAs are present in 31% to 38% of patients and are associated with a vasculitis phenotype of the disease, whereas patients without MPO-ANCA are at risk of cardiac involvement. Despite significant advances in understanding the overall pathogenesis of the disease, the explanation for this dichotomy is still unclear. In this review, we synthesize our knowledge of the pathogenesis of EGPA and attempt to i) distinguish EGPA from other diseases including other AAVs, asthma, allergy and hypereosinophilic-associated conditions and ii) speculate about the preponderant mechanisms, which could explain the two disease phenotypes. PMID:26506114

  15. Universal Service in a Broader Perspective: The European Digital Divide

    Directory of Open Access Journals (Sweden)

    Maria Concepcion GARCIA-JIMENEZ

    2009-01-01

    Full Text Available Ensuring universal service is a top objective in many countries in order that all the citizens can have access basic communications services. Although the ICT equipment in households and its usage by individuals are essential prerequisites for benefiting from ICTs, the situation in the European Union is far from uniform. This article provides a description of the European information society development scenario using the values reached by the member states in a set of indicators selected for measuring said progress in households. Two tools are used for providing a broader perspective of the digital divide: a composite index and the cluster analysis. Below, a study is provided on what variables are relevant for interpreting the situation that is presented.

  16. Bridging the divide : understanding and managing local opposition

    Energy Technology Data Exchange (ETDEWEB)

    Timm, D. [AIM PowerGen Corp., Toronto, ON (Canada)

    2009-07-01

    Anti-wind activists and concerned citizens are becoming increasingly organized, sophisticated and well-backed, yet opinion polls on public attitudes towards wind energy development consistently demonstrate strong support for wind power. This presentation discussed the need to understand and manage local opposition to wind power. This presentation included background information on this opposition and explained how to assess opponents potential. In order to bridge the divide, it was noted that it is important to understand the political climate of the area and local attitudes before going public with a project. Meeting with the opponents and timing are both critical. Methods to bridge the gap in knowledge and understanding include building support, motivating support, negotiating and educating, organizing tours to existing wind farms, and holding community events. Lastly, support and advocacy groups can also mobilize members to attend and provide testimony at public hearings, to contact local media, and to make presentations before other community organizations.

  17. Spectral statistics of a system with sharply divided phase space

    International Nuclear Information System (INIS)

    We construct a family of non-Kolmogorov-Arnold-Moser (non-KAM) piecewise-linear continuous 2D area-preserving maps which have sharply divided phase space with regions of regular elliptic and chaotic hyperbolic motion. For such systems the shape of the islands of regular motion is either a solid ellipse or a solid polygon, depending on the (ir)rationality of the frequency, and thus the total area of the regular region of phase space can be computed analytically or at least rigorously estimated from below. We analyse the spectral statistics for a few examples of the quantization of our maps, and show that they provide a convenient 'playground' for testing and confirming the key assumptions required for the validity of Berry-Robnik formulae. (author)

  18. Divide and be different: Priestly identity in the Persian period

    Directory of Open Access Journals (Sweden)

    Esias E. Meyer

    2012-07-01

    Full Text Available The article focused on the Hebrew root לדב [divide] [bdl] in Priestly and post-Priestly material of the Pentateuch. In Genesis 1 God is the subject of the verb and often enough in the Holiness Code, but in many instances in Leviticus (e.g. 10:10 and 11:47 it is expected of priests to perform the same act. It was argued that in this regard priests were to imitate God. The article further argued that these texts helped us to describe Jewish identity in the Persian period as an identity of non-conformity, and they also helped us to describe the priests’ own understanding of their role in maintaining this identity.

  19. Digital Divide between Teachers and Students in Urban Bangladesh

    DEFF Research Database (Denmark)

    Khalid, Md. Saifuddin

    (62%) and study (44%). 69% teachers and 66% students use social networking sites. Top three online activities for students are music (53%), games (47%) and chat (42%), for teachers these are study (55%), chat (40%) and music (33%). Students use more mobile features than teachers. Interestingly 59...... University, Bangladesh (IUB) in autumn 2009 participated in conducting survey activities. Total 33 academic institutes were south for approval and 11 could be surveyed before the Christmas and annual recess. Responses from 6 other academics institutes were collected from the personal networks of students. A...... data available on them in Bangladesh context. A study was conducted to study the digital divide and ICT usage pattern among the urban students and teachers of schools and colleges in Dhaka, the capital of Bangladesh. About 75 students enrolled in probability and statistics course of Independent...

  20. Nationality Divides and Shared Leadership in Multinational Teams

    DEFF Research Database (Denmark)

    Paunova, Minna

    2015-01-01

    nationality-based characteristics of members may divide teams and affect leadership. We argue that the national belonging of members may result in both identity subgroups and status ranks. However, the configurational properties of identity subgroups and status ranks will have distinct effects on team......How shared leadership is enacted in teams that are nationally diverse is currently under- researched, despite the increasing presence of multinational teams in the workplace. To better understand the phenomenon of shared leadership in multinational team contexts, we propose two ways in which...... dynamics, shared leadership within the team, and team performance. We conduct two empirical studies, and find that the number and balance of identity subgroups have important implications for multinational team functioning, in line with social identity approaches. Interestingly, the number and balance of...

  1. Charge state of finely divided conducting systems in dielectric matrix

    International Nuclear Information System (INIS)

    The calculation of the high statistic sum Z of the charged metal granules in the dielectric matrix is carried out with an account of the excess number of the Fermi-particles fluctuations on the granules. Application of a microscopic Hamiltonian for the energy of electrostatic interaction between the charge densities in the system makes it possible to accomplish these calculations in the average field approximation. The effect of the number of the Fermi-particles fluctuations on the charge state of the finely divided granules in the dielectric matrix is studied. It is supposed that the charge exchange between the composite metal elements occurs on the account of the electron overbarrier heat transfer. It is followed from the system high statistic sum calculation results that the i-granule medium charge is connected by the nonlinear ratio with the conductors Vi potentials

  2. Divided-pulse nonlinear amplification and simultaneous compression

    Energy Technology Data Exchange (ETDEWEB)

    Hao, Qiang; Zhang, Qingshan; Sun, Tingting; Chen, Jie; Wang, Yuqing; Guo, Zhengru; Yang, Kangwen [Shanghai Key Laboratory of Modern Optical System, and Engineering Research Center of Optical Instrument and System, Ministry of Education, School of Optical Electrical and Computer Engineering, University of Shanghai for Science and Technology, Shanghai 200093 (China); Guo, Zhanhua [Shanghai Langyan Optoelectronic Science and Technology Co., LTD, Shanghai 200433 (China); Zeng, Heping, E-mail: hpzeng@phy.ecnu.edu.cn [Shanghai Key Laboratory of Modern Optical System, and Engineering Research Center of Optical Instrument and System, Ministry of Education, School of Optical Electrical and Computer Engineering, University of Shanghai for Science and Technology, Shanghai 200093 (China); State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062 (China)

    2015-03-09

    We report on a fiber laser system delivering 122 fs pulse duration and 600 mW average power at 1560?nm by the interplay between divided pulse amplification and nonlinear pulse compression. A small-core double-clad erbium-doped fiber with anomalous dispersion carries out the pulse amplification and simultaneously compresses the laser pulses such that a separate compressor is no longer necessary. A numeric simulation reveals the existence of an optimum fiber length for producing transform-limited pulses. Furthermore, frequency doubling to 780?nm with 240 mW average power and 98 fs pulse duration is achieved by using a periodically poled lithium niobate crystal at room temperature.

  3. Divided-pulse amplification for terawatt-class fiber lasers

    Science.gov (United States)

    Eidam, T.; Kienel, M.; Klenke, A.; Limpert, J.; Tünnermann, A.

    2015-10-01

    The coherent combination of ultra short laser pulses is a promising approach for scaling the average and peak power of ultrafast lasers. Fiber lasers and amplifiers are especially suited for this technique due to their simple singe-pass setups that can be easily parallelized. Here we propose the combination of the well-known approach of spatially separated amplification with the technique of divided-pulse amplification, i.e. an additionally performed temporally separated amplification. With the help of this multidimensional pulse stacking, laser systems come into reach capable of emitting 10's of joules of energy at multi-kW average powers that simultaneously employ a manageable number of fibers.

  4. Spike sorting for polytrodes: a divide and conquer approach

    Directory of Open Access Journals (Sweden)

    Nicholas V. Swindale

    2014-02-01

    Full Text Available In order to determine patterns of neural activity, spike signals recorded by extracellular electrodes have to be clustered (sorted with the aim of ensuring that each cluster represents all the spikes generated by an individual neuron. Many methods for spike sorting have been proposed but few are easily applicable to recordings from polytrodes which may have 16 or more recording sites. As with tetrodes, these are spaced sufficiently closely that signals from single neurons will usually be recorded on several adjacent sites. Although this offers a better chance of distinguishing neurons with similarly shaped spikes, sorting is difficult in such cases because of the high dimensionality of the space in which the signals must be classified. This report details a method for spike sorting based on a divide and conquer approach. Clusters are initially formed by assigning each event to the channel on which it is largest. Each channel-based cluster is then sub-divided into as many distinct clusters as possible. These are then recombined on the basis of pairwise tests into a final set of clusters. Pairwise tests are also performed to establish how distinct each cluster is from the others. A modified gradient ascent clustering (GAC algorithm is used to do the clustering. The method can sort spikes with minimal user input in times comparable to real time for recordings lasting up to 45 minutes. Our results illustrate some of the difficulties inherent in spike sorting, including changes in spike shape over time. We show that some physiologically distinct units may have very similar spike shapes. We show that RMS measures of spike shape similarity are not sensitive enough to discriminate clusters that can otherwise be separated by principal components analysis. Hence spike sorting based on least-squares matching to templates may be unreliable. Our methods should be applicable to tetrodes and scaleable to larger multi-electrode arrays (MEAs.

  5. Closing the divide: Can the IAEA make a difference?

    International Nuclear Information System (INIS)

    Over the last two decades, the world has seen many fundamental changes in the way countries interact. It is seen today in how business is conducted, how fast travel and super-fast communications have opened up the world into almost one huge market and how news of break-through technological innovations appear almost weekly in the media. Yet the world still lives with a vast divide between rich and poor and, from many perspectives, this divide appears to be increasing. The world's development programmes have thus been increasingly scrutinized for their effectiveness and efficiency. The aim is to ensure that the planned benefits reach the end-beneficiaries in a manner that adequately addresses the socio-economic needs of the recipient society. Against this background, the IAEA's relatively small but nevertheless significant programme of technical cooperation has had to reform itself. It has gone from a largely 'technology push' focus to adopting a new 'needs driven' strategy. As the world marks 50 years of the 'Atoms for Peace' initiative, the questions must be asked whether the IAEA's Technical Cooperation Programme (TCP) really can make a difference? Is this programme correctly positioned to be able to meet these very large global challenges? Must it reform itself further to remain meaningful and relevant? What are the determinants for its success within a highly demanding environment? These are the typical questions that have largely shaped the deliberations between the IAEA Technical Cooperation Department and its Standing Advisory Group, called SAGTAC, since the group of representatives from Member States was formed in the mid- 1990s

  6. Divided Attention and Processes Underlying Sense of Agency.

    Science.gov (United States)

    Wen, Wen; Yamashita, Atsushi; Asama, Hajime

    2016-01-01

    Sense of agency refers to the subjective feeling of controlling events through one's behavior or will. Sense of agency results from matching predictions of one's own actions with actual feedback regarding the action. Furthermore, when an action involves a cued goal, performance-based inference contributes to sense of agency. That is, if people achieve their goal, they would believe themselves to be in control. Previous studies have shown that both action-effect comparison and performance-based inference contribute to sense of agency; however, the dominance of one process over the other may shift based on task conditions such as the presence or absence of specific goals. In this study, we examined the influence of divided attention on these two processes underlying sense of agency in two conditions. In the experimental task, participants continuously controlled a moving dot for 10 s while maintaining a string of three or seven digits in working memory. We found that when there was no cued goal (no-cued-goal condition), sense of agency was impaired by high cognitive load. Contrastingly, when participants controlled the dot based on a cued goal (cued-goal-directed condition), their sense of agency was lower than in the no-cued-goal condition and was not affected by cognitive load. The results suggest that the action-effect comparison process underlying sense of agency requires attention. On the other hand, the weaker influence of divided attention in the cued-goal-directed condition could be attributed to the dominance of performance-based inference, which is probably automatic. PMID:26858680

  7. Older people and digital disengagement: a fourth digital divide?

    Science.gov (United States)

    Olphert, Wendy; Damodaran, Leela

    2013-01-01

    Digital technologies are becoming more pervasive in all areas of society. Enabling everyone to have access and capability to use the Internet and associated digital technologies, summed up in the term 'digital inclusion', is seen to have wide-ranging benefits to the individual, to the economy and to society. For older people, being digitally included can help them to maintain their independence, social connectedness and sense of worth in the face of declining health or limited capabilities, as well as also offering new opportunities to improve their quality of life. At present however, access to the technology and to the benefits is not equally distributed either between or within nations, and older people tend to be on the 'wrong' side of what is termed the 'digital divide'. Governments globally are developing strategies to promote digital inclusion and indeed Internet uptake is increasing steadily, including amongst older people. However, such strategies have focussed on getting people online, and there appears to be an assumption that once someone is online they will remain 'digitally engaged'. In fact statistics show that some users give up using the Internet, and there is emerging evidence that older people are more vulnerable to the factors which can lead to this outcome. The authors see this phenomenon as a potential but largely unrecognised 'fourth digital divide' which has serious implications for social inclusion. The objectives of this article are (a) to raise awareness of the phenomenon of digital disengagement by considering some of the emerging evidence, (b) to explore some of the potential implications of not recognising and therefore not addressing the needs of the digitally disengaged older population, and (c) to reveal the prevailing gap in knowledge which future research should address. PMID:23969758

  8. Water

    Science.gov (United States)

    ... Fats Vitamins & Minerals Water Plans for Healthy Eating Healthy Lifestyle Shopping Tips Food Safety Common Questions Learn More ... adding calories. Learn More: Important Nutrients to Know Healthy Lifestyle Related publications: Choosing Healthy Meals As You Get ...

  9. Not Just an Access Issue: Further Analysis of the Digital Divide from a Socioeconomic Perspective

    Science.gov (United States)

    Milheim, Karen L.

    2006-01-01

    In recent years, a concern surrounding technology access to historically marginalized populations, referred to as the "Digital Divide" (Divide), has surfaced. This analysis examines the Digital Divide from a socioeconomic standpoint, and discusses the effects of the Divide on students. Also addressed are the varying perspectives towards the

  10. Microstructure and temperature coefficient of resistance of thin cermet resistor films deposited from CrSi2-Cr-SiC targets by S-gun magnetron

    International Nuclear Information System (INIS)

    Technological solutions for producing nanoscale cermet resistor films with sheet resistances above 1000 Ω/□ and low temperature coefficients of resistance (TCR) have been investigated. 2-40 nm thick cermet films were sputter deposited from CrSi2-Cr-SiC targets by a dual cathode dc S-gun magnetron. In addition to studying film resistance versus temperature, the nanofilm structural features and composition were analyzed using scanning electron microscopy, atomic force microscopy, high-resolution transmission electron microscopy, energy-dispersive x-ray spectroscopy, and electron energy loss spectroscopy. This study has revealed that all cermet resistor films deposited at ambient and elevated temperatures were amorphous. The atomic ratio of Si to Cr in these films was about 2 to 1. The film TCR displayed a significant increase when the deposited film thickness was reduced below 2.5 nm. An optimized sputter process consisting of wafer degassing, cermet film deposition at elevated temperature with rf substrate bias, and a double annealing in vacuum, consisting of in situ annealing following the film sputtering and an additional annealing following the exposure of the wafers to air, has been found to be very effective for the film thermal stabilization and for fine tuning the film TCR. Cermet films with thicknesses in the range of 2.5-4 nm deposited using this technique had sheet resistances ranging from 1800 to 1200 Ω/□ and TCR values from -50 ppm/ deg. C to near zero, respectively. A possible mechanism responsible for the high efficiency of annealing the cermet films in vacuum (after preliminary exposure to air), resulting in resistance stabilization and TCR reduction, is also discussed.

  11. “Identity Monarchy”: Interrogating Heritage for a Divided Malaysia

    Directory of Open Access Journals (Sweden)

    Anthony Milner

    2012-08-01

    Full Text Available Malaysia, it has been observed, is currently experiencing a “revival” of “Malay kingship” with the growing importance of “proactive and participating constitutional rulers.” In fact, modern Malaysia has since independence been characterized by monarchy—by a multiplicity of Rulers and elaborate royal ceremony and hierarchy—as well as by its “plural society.” But the modern monarchs—though they have never become quite “constitutional Rulers”—cannot be seen as merely “traditional,”because the institution of monarchy was transformed in a fundamental way during the British colonial period. Monarchy continues to be an underexamined feature of the Malaysian polity, and when it is discussed there is a tendency to focus on issues of power and to neglect its sociocultural role. One pre-colonial dimension of monarchy that continues to be significant today—though in a manner less psychologically profound than before—is its identity-giving role. The principal concern of this article is to determine—through a process of hermeneutic retrieval—if this role is merely relevant to the Malay community, or does it possess more inclusive possibilities? Are the Rulers of Malaysia essentially “Malay Rulers” or has the institution a nation-building potential that has so far not been fully utilized? The question is important for a country that many see as becoming increasingly divided.

  12. Study and achievement of a digital-analog-divider

    International Nuclear Information System (INIS)

    This apparatus is designed to give directly, in digital form, the value of the ratio Vt1/V2 two analog voltages. It consists essentially of an analog-digital coder operating by successive weighing; the comparison voltage is made proportional to the divider V2 in the coder. The input dynamics are such that the voltages Vi and V2 are all in the range -50 mV to -5 V. Each of the circuits has an input impedance of about 10 KΩ. As for the quotient, it is a binary number given in series and parallel form; it is made up of 8 bits, this giving a change of 1/16 to 16 per jump of 1/16 in the zone where the accuracy is highest (V2 ≥ 800 mV). The time required for a division is, at best, 15 μsec. During the time of calculation, the voltages V1 and V2 should not vary by more than 1 per cent and 0.5 per cent respectively. The theory of the system and the investigation of a synoptic diagram, the study of the circuits and the actual construction are presented. (author)

  13. Molecular profiling and the reclassification of cancer: divide and conquer.

    Science.gov (United States)

    Munoz, Javier; Swanton, Charles; Kurzrock, Razelle

    2013-01-01

    Cancer is one of the leading causes of mortality in the world. Choosing the best treatment is dependent on making the right diagnosis. The diagnostic process has been based on light microscopy and the identification of the organ of tumor origin. Yet we now know that cancer is driven by molecular processes, and that these do not necessarily segregate by organ of origin. Fortunately, revolutionary changes in technology have enabled rapid genomic profiling. It is now apparent that neoplasms classified uniformly (e.g., non-small cell lung cancer) are actually comprised of up to 100 different molecular entities. For instance, tumors bearing ALK alterations make up about 4% of non-small cell lung cancers, and tumors bearing epidermal growth factor receptor (EGFR) mutations, approximately 5% to 10%. Importantly, matching patients to therapies targeted against their driver molecular aberrations has resulted in remarkable response rates. There is now a wealth of evidence supporting a divide-and-conquer strategy. Herein, we provide a concise primer on the current state-of-the-art of molecular profiling in the cancer clinic. PMID:23714478

  14. Informaticiens Sans Frontieres: Helping to bridge the Digital Divide

    CERN Document Server

    CERN. Geneva

    2009-01-01

    ISF was formed as a CERN club during the World Summit for the Information Society, in Geneva, in 2003. Today we are involved in a number of international projects aimed to helping Africa bridge the Digital Divide, as well as using computing power (BOINCs) in the research against Malaria, or creating GRIDs that could allow African universities to join us in scientific research projects such as the LHC. Our latest project, named MANGO Net, is aimed at capacity building, by creating a network of computer assembly schools across the continent, which would form hardware and software technicians, create assembly centres, and lay the foundation for a future IT industry. ISF est né comme un club du CERN, en 2003, pendant le Sommet Mondiale de la Société de l'information à Genève. Aujourd'hui nous participons à plusieurs projets avec le but d'aider l'Afrique à reduire la Fracture Numérique, ou de fournir de la puissance de calcul (BOINC) à la recherche contre le Paludisme, ou en créant des GRIDs qui pourra...

  15. Universal logic gates via liquid-electronic hybrid divider

    KAUST Repository

    Zhou, Bingpu

    2012-01-01

    We demonstrated two-input microdroplet-based universal logic gates using a liquid-electronic hybrid divider. All 16 Boolean logic functions have been realized by manipulating the applied voltages. The novel platform consists of a microfluidic chip with integrated microdroplet detectors and external electronic components. The microdroplet detectors act as the communication media for fluidic and electronic information exchange. The presence or absence of microdroplets at the detector translates into the binary signal 1 or 0. The embedded micro-mechanical pneumatically actuated valve (PAV), fabricated using the well-developed multilayer soft lithography technique, offers biocompatibility, flexibility and accuracy for the on-chip realization of different logic functions. The microfluidic chip can be scaled up to construct large-scale microfluidic logic computation. On the other hand, the microfluidic chip with a specific logic function can be applied to droplet-based chemical reactions for on-demand bio or chemical analysis. Our experimental results have presented an autonomously driven, precision-controlled microfluidic chip for chemical reactions based on the IF logic function. © 2012 The Royal Society of Chemistry.

  16. Universal logic gates via liquid-electronic hybrid divider.

    Science.gov (United States)

    Zhou, Bingpu; Wang, Limu; Li, Shunbo; Wang, Xiang; Hui, Yu Sanna; Wen, Weijia

    2012-12-21

    We demonstrated two-input microdroplet-based universal logic gates using a liquid-electronic hybrid divider. All 16 Boolean logic functions have been realized by manipulating the applied voltages. The novel platform consists of a microfluidic chip with integrated microdroplet detectors and external electronic components. The microdroplet detectors act as the communication media for fluidic and electronic information exchange. The presence or absence of microdroplets at the detector translates into the binary signal 1 or 0. The embedded micro-mechanical pneumatically actuated valve (PAV), fabricated using the well-developed multilayer soft lithography technique, offers biocompatibility, flexibility and accuracy for the on-chip realization of different logic functions. The microfluidic chip can be scaled up to construct large-scale microfluidic logic computation. On the other hand, the microfluidic chip with a specific logic function can be applied to droplet-based chemical reactions for on-demand bio or chemical analysis. Our experimental results have presented an autonomously driven, precision-controlled microfluidic chip for chemical reactions based on the IF logic function. PMID:23111629

  17. BRIDGING THE KNOWLEDGE DIVIDE Educational Technology for Development

    Directory of Open Access Journals (Sweden)

    Reviewed by Ozlem OZAN,

    2009-10-01

    Full Text Available BRIDGING THE KNOWLEDGE DIVIDEEducational Technology for DevelopmentMarshall,S., Kinuthia, W. & Wallace Taylor., Ed.D.; Information Age Publishing, Charlotte, NC, SBN: 978-1-60752-109-9, p.433, 2009Reviewed by Ozlem OZANFaculty of EducationEskişehir Osmangazi UniversityEskisehir, TURKEYThe concept of a knowledge divide is used to describe the gap in living conditions between those who can find, manage and process information or knowledge, and those who are impaired in this, for one reason or another. In the 21st century, the emergence of the knowledge society becomes pervasive hence the information and ICT systems that support knowledge are very important.This book discusses how educational technology can be used to transform education and assist developing communities to close the knowledge divide. Its broader audience is anyone who is interested in educational technology for development. In the book you can find best practices and case studies especially from countries in Africa.The book is edited by Stewart Marshall, Wanjira Kinuthia, Wallace Taylor. Professor Stewart Marshall, PhD, is the director of the Academic Division of the University of the West Indies Open Campus (UWIOC and holds the UNESCO Chair in Educational Technologies.Dr. Wanjira Kinuthia is assistant professor of Learning Technologies at Georgia State University. She works as an instructional designer in higher education and business and industry for several years. Professor Wallace Taylor, PhD, is a founding director of The Information Society Institute (TISI, a non-profit academic, research, and policy development organization based in South Africa.The book is consisted of 433 pages (+xxxv covering 24 articles divided into four sections and provides information about flexible learning for empowerment, managing and communicating knowledge, flexible delivery in higher education and preparing teacher using flexible approaches.Topics covered in the book are as follows:Flexible Education and Community Development, Flexible Learning for Community Economic Development, Contribution of the IDE in Promoting Gender Equality and in Empowering Women in Swaziland, A Virtual Wheel of Fortune?: Enablers and Constraints of ICTs in Higher Education in South Africa, Delivering Distance Education for the Civil Service in the UK: The University of Chester’s Foundation for Government Program, Knowledge Management Strategies for Distance Education, The Effectiveness of Mobile Short Messaging Service (SMS Technologies in the Support of Selected Distance Education Students of Makerere University, Uganda, The Impact of Video Conferencing on Distance Education Courses: A University of Namibia Case Study, Open Resources for Open Learning in Developing Countries: Deciphering Trends for Policies, Quality, and Standards Considerations, Freedom, Innovation, and Equity with Open Source Software, Copyright Issues and their Impact on Flexible Education in Africa, University Education for National Development: Makerere University’s Dual Mode Experience, Considerations for Higher Education Distance Education Policy for Development: A Case of the University of Botswana,Blended Online and Face-to-Face Learning: A Pilot Project in the Faculty of Education, Eduardo Mondlane University, Evaluating the Impact of CABLE: A Cognitive Apprenticeship-Based Learning Environment, From Distance Learning to E-learning in Central and Northern Mozambique, A Framework for the Delivery of Cross-Regional Distance Education to Professionals in Developing Countries, Distance Learning—Challenges and Opportunities for Postgraduate Medical Education: A Case Study of Postgraduate Training in Family Medicine Using Distance Learning at the University of the West Indies (2001–2006, Pre-service Teacher Preparation and Effective eLearning, Distance Teacher Training in Rwanda: Comparing the Costs, Beckoning E-Learners through Exploration of Computer Technology, Educational Technology and Flexible Education in Nigeria: Meeting the Need for Effective Teacher Education, Fostering Digital Literacy of Primary Teachers in Community Schools: The BET K–12 Experience in Salvador de Bahia.First section of the book consists of five chapters. It deals with some of the key issues in flexible education as a means of bridging the knowledge divide, empowering groups and building cohesive communities. In first two chapters, identifications and of critical factors and constraints to the delivery of flexible education for community development is provided. Paradigm shift to more open and flexible learning is discussed. In next chapter, a distance education application as case study is given in promoting gender equality and in empowering women in Swaziland. Fourth chapter presents a regional perspective on how academic staff and students are enabled and constrained by access to variety of resources. Finally, some of the lessons learned from Delivering Distance Education for the Civil Service in the UK: The University of Chester’s Foundation for Government Program are given.Second section, consists of six chapters, and covers topics of knowledge management, specific technologies that can be used in the facilitation of flexible learning and open educational resources as an issue of access to knowledge.First of all it provides an introduction to the concept of knowledge management and emphasizes its importance in distance education. Then more effective usage of mobile technologies is mentioned and a Uganda example is given.Furthermore, the impact of video conferencing on distance education is mentioned from University of Naibia’s point of view. On the other hand open access movement and open educational resource (OER is reviewed in the light of knowledge society trend. Finally copyright issue and their impact on flexible education are discussed.Third chapter looks at some of the methods adopted by universities often in difficult circumstance. Examples from dual mode universities Makerere University in Uganda and University of Botswana, Eduardo Mondlane Univeristy, Catholic University of Mozambique are given and discussed. Within this context challenges and solutions are mentioned. Furthermore some framework for distance education planning and programming are offered. Results of evaluation study on the impact of a Cognitive Apprenticeship-Based Learning Environment are discussed.Flexibility of teacher education is an important issue for flexible education of students. Because of this, final section, which consists of five chapters, focuses on flexible learning and teaching into teacher preparation. Case studies and thoughts from China, Rwanda, Nigeria, Salvador de Bahia are shared.BIODATA and CONTACT ADDRESSES of AUTHOROzlem OZAN, MA has been a Research Assistant in Department of Computer Education & Instructional Technology at Eskisehir Osmangazi University in Turkey since 2002. She received B.S. degree in Electrical and Electronics Engineering Department and master’s degree in Distance Education at Anadolu University. Her research interests are distance education, information and communication technologies. She also gives lessons about multimedia development as an instructor

  18. Bridging the transatlantic climate divide. Final project paper

    International Nuclear Information System (INIS)

    International climate change policy is presently dominated by the different visions of two major blocks, the USA and EU. It is not always realized that a part of these differences is more fundamental than one may expect in view of the historical connections between the populations of the two continents. Socio-cultural aspects like the role of government, the value of individual liberty and the consequences of population density are different in both regions and play an important role in determining what is acceptable policy-wise. Despite the apparent stalemate in formal positions, signs have been detected that indicate that the 'transatlantic divide' on this issue is (slowly) closing. One cause is that bottom-up momentum is building up in the USA, which can eventually push the federal level to initiate a more active policy. Another cause is the finding in the EU that it turns out to be difficult to reach the Kyoto-targets, which results in the development of policy instruments that could be attractive for the USA to endorse or even participate in. Such instruments could have similarities with the Kyoto Protocol. To obtain more insight in the driving forces behind such changes and why they lead to higher or lower acceptability of certain policy instruments, it makes sense to identify attitudinal indicators that signify such changes. By regularly monitoring these attitudinal indicators, e.g., concrete behavior of companies, proportional media attention, formal political statements, and relating the value of these indicators to a corresponding set of policy instruments, policy makers at both sides of the Atlantic Ocean have an extra tool at their disposal to frame the issue and identify joint solutions in a way that is acceptable to the other party. This project makes a first attempt to design such a method (dynamic analytic model). It holds promises, and it is recommended to develop this model further in order to support the effectiveness of the climate negotiations

  19. Bridging the transatlantic climate divide. Final project paper. Appendices

    International Nuclear Information System (INIS)

    International climate change policy is presently dominated by the different visions of two major blocks, the USA and EU. It is not always realized that a part of these differences is more fundamental than one may expect in view of the historical connections between the populations of the two continents. Socio-cultural aspects like the role of government, the value of individual liberty and the consequences of population density are different in both regions and play an important role in determining what is acceptable policy-wise. Despite the apparent stalemate in formal positions, signs have been detected that indicate that the 'transatlantic divide' on this issue is (slowly) closing. One cause is that bottom-up momentum is building up in the USA, which can eventually push the federal level to initiate a more active policy. Another cause is the finding in the EU that it turns out to be difficult to reach the Kyoto-targets, which results in the development of policy instruments that could be attractive for the USA to endorse or even participate in. Such instruments could have similarities with the Kyoto Protocol. To obtain more insight in the driving forces behind such changes and why they lead to higher or lower acceptability of certain policy instruments, it makes sense to identify attitudinal indicators that signify such changes. By regularly monitoring these attitudinal indicators, e.g., concrete behavior of companies, proportional media attention, formal political statements, and relating the value of these indicators to a corresponding set of policy instruments, policy makers at both sides of the Atlantic Ocean have an extra tool at their disposal to frame the issue and identify joint solutions in a way that is acceptable to the other party. This project makes a first attempt to design such a method (dynamic analytic model). It holds promises, and it is recommended to develop this model further in order to support the effectiveness of the climate negotiations

  20. HIV-1 latency in actively dividing human T cell lines

    Directory of Open Access Journals (Sweden)

    Berkhout Ben

    2008-04-01

    Full Text Available Abstract Background Eradication of HIV-1 from an infected individual cannot be achieved by current drug regimens. Viral reservoirs established early during the infection remain unaffected by anti-retroviral therapy and are able to replenish systemic infection upon interruption of the treatment. Therapeutic targeting of viral latency will require a better understanding of the basic mechanisms underlying the establishment and long-term maintenance of HIV-1 in resting memory CD4 T cells, the most prominent reservoir of transcriptional silent provirus. However, the molecular mechanisms that permit long-term transcriptional control of proviral gene expression in these cells are still not well understood. Exploring the molecular details of viral latency will provide new insights for eventual future therapeutics that aim at viral eradication. Results We set out to develop a new in vitro HIV-1 latency model system using the doxycycline (dox-inducible HIV-rtTA variant. Stable cell clones were generated with a silent HIV-1 provirus, which can subsequently be activated by dox-addition. Surprisingly, only a minority of the cells was able to induce viral gene expression and a spreading infection, eventhough these experiments were performed with the actively dividing SupT1 T cell line. These latent proviruses are responsive to TNFα treatment and alteration of the DNA methylation status with 5-Azacytidine or genistein, but not responsive to the regular T cell activators PMA and IL2. Follow-up experiments in several T cell lines and with wild-type HIV-1 support these findings. Conclusion We describe the development of a new in vitro model for HIV-1 latency and discuss the advantages of this system. The data suggest that HIV-1 proviral latency is not restricted to resting T cells, but rather an intrinsic property of the virus.

  1. To divide or not to divide: An alternative behavior for teratocytes in Encarsia pergandiella (Hymenoptera: Aphelinidae).

    Science.gov (United States)

    Mancini, Donato; Garonna, Antonio P; Pedata, Paolo A

    2016-01-01

    Encarsia pergandiella (Hymenoptera: Aphelinidae) is an endoparasitoid with an unusual embryonic development compared to most of congeneric species and all other members of the superfamily Chalcidoidea. The developmental background of this wasp is based on an alecithal hydropic egg, with the embryo developing inside an extra-embryonic membrane which dissociates at hatching into special larva-assisting cells, the teratocytes. In E. pergandiella many teratocytes at hatching were multinucleated syncytial cells with no evidence of a cellular membrane separating the nuclei. These teratocytes during larval development produced smaller uninucleated teratocytes, through successive divisions obtained by progressive ingrowth of the plasmatic membrane, accompanied by appearance of degeneration symptoms, such as protrusions and blebs. As a consequence of this divisional process teratocytes showed a size reduction and an increase in number of about four times during the second day of larval development. Only on the third day of larval life teratocytes started to decrease in number, until total disappearance at larval maturation. This behaviour is in striking contrast with all other studied systems in which teratocytes do not divide and progressively decrease in number as the parasitoid larva develops. PMID:26529581

  2. GLOBAL WATER MARKET

    OpenAIRE

    Bakri, Bambang; Arai, Yasuhiro; Inakazu, T; Koizumi, A.; Pallu, Saleh

    2015-01-01

    Water markets data is a useful tool for understanding the informal water sector. It provides information to assist decision-makers in establishing or improving water infrastructure.markets data is a useful tool for understanding the informal water sector. The water utilities market is divided to capital expenditure (CAPEX) and operating expenditure (OPEX). This study reviews and analyzes a report of global water market to describe municipal water market from all over the world. Global water m...

  3. Development of a new lower hybrid antenna module using a poloidal power divider

    International Nuclear Information System (INIS)

    A realistic antenna module using a poloidal divider for lower hybrid current drive (LHCD) experiment, is modelled and fabricated. In this antenna module test II, three types of poloidal dividers, which split the power in 3, are tested. (author)

  4. Number of binomial coefficients divided by a fixed power of a prime

    OpenAIRE

    Everett, William B.

    2007-01-01

    We state a general formula for the number of binomial coefficients $n$ choose $k$ that are divided by a fixed power of a prime $p$, i.e., the number of binomial coefficients divided by $p^j$ and not divided by $p^{j+1}$.

  5. Natural convection in undivided and partially divided rectangular enclosures

    International Nuclear Information System (INIS)

    Heat transfer by natural convection in a two-dimensional rectangular enclosure fitted with partial vertical divisions in investigated experimentally. The horizontal walls of the enclosure are adiabatic while the vertical walls are maintained at different temperatures. The experiments are carried out with water, Prapprox. =3.5, for Rayleigh numbers in the range, 2.3 x 101011, and an aspect ratio, A = H/L = 1/2. The effect of the partial vertical divisions on the fluid flow and temperature fields is investigated by dye-injection flow visualization and by thermocouple probes, respectively. The effect of the partitions on heat transfer across the enclosure is also studied and correlations for the Nusselt number as a function of Ra/sub L/ and partition length are generated for both conducting and non-conducting partition materials. Partial divisions are found to have a significant effect on the heat transfer; especially when the divisions are adiabatic. The results also indicate that the partial divisions may have a stabilizing effect on the laminar-transitional flow on the heated vertical walls of the enclosure

  6. Biological pretreatment sewages water

    OpenAIRE

    Veselý, Václav

    2009-01-01

    Bachelor's thesis deals with waste water purification at the stage of pre-inflow of water into the biological waste water treatment plants. It is divided into two parts, a theoretical and calculation. The theoretical part deals about sewage water and the method of biological treatment. Design proposal is part of the activation tank for quantity EO.

  7. Fracture resistance evaluation of RuO2-based thick film resistor material by in situ crack extension observation in a scanning electron microscope

    International Nuclear Information System (INIS)

    Parameters for the fracture mechanics of thick film materials are scarce in the literature. One reason is that for many such materials it is very difficult to produce a bulk specimen as required for most standard tests. This paper describes an alternative method for measuring the fracture resistance of a ruthenium dioxide (RuO2)-based thick film resistor material for electronic applications. The method is based on an in situ investigation of crack propagation in the loaded material. The investigated material is printed as a thick film on a substrate of low-temperature-co-fired-ceramic. An initial crack in the film is introduced with a Vickers indenter. The crack is subsequently loaded with a four-point bending equipment in a scanning electron microscope, which allows for in situ crack length measurement. The crack growth measurements reveal that once a certain crack length is achieved the load required to extend the crack becomes independent of the crack length. Beyond this length, the crack propagates in the so-called steady-state region, which is used in the present method to estimate the fracture resistance of the film. Both tensile stresses resulting from bending and tensile residual stresses are taken into account. Although a brittle substrate was used, the crack did not penetrate into the substrate. The measured fracture resistance of 0.69 ± 0.14 MPa√m is found to be realistic for the investigated thick film material with high silicate glass content

  8. A divide-conquer-recombine algorithmic paradigm for large spatiotemporal quantum molecular dynamics simulations.

    Science.gov (United States)

    Shimojo, Fuyuki; Hattori, Shinnosuke; Kalia, Rajiv K; Kunaseth, Manaschai; Mou, Weiwei; Nakano, Aiichiro; Nomura, Ken-ichi; Ohmura, Satoshi; Rajak, Pankaj; Shimamura, Kohei; Vashishta, Priya

    2014-05-14

    We introduce an extension of the divide-and-conquer (DC) algorithmic paradigm called divide-conquer-recombine (DCR) to perform large quantum molecular dynamics (QMD) simulations on massively parallel supercomputers, in which interatomic forces are computed quantum mechanically in the framework of density functional theory (DFT). In DCR, the DC phase constructs globally informed, overlapping local-domain solutions, which in the recombine phase are synthesized into a global solution encompassing large spatiotemporal scales. For the DC phase, we design a lean divide-and-conquer (LDC) DFT algorithm, which significantly reduces the prefactor of the O(N) computational cost for N electrons by applying a density-adaptive boundary condition at the peripheries of the DC domains. Our globally scalable and locally efficient solver is based on a hybrid real-reciprocal space approach that combines: (1) a highly scalable real-space multigrid to represent the global charge density; and (2) a numerically efficient plane-wave basis for local electronic wave functions and charge density within each domain. Hybrid space-band decomposition is used to implement the LDC-DFT algorithm on parallel computers. A benchmark test on an IBM Blue Gene/Q computer exhibits an isogranular parallel efficiency of 0.984 on 786 432 cores for a 50.3 × 10(6)-atom SiC system. As a test of production runs, LDC-DFT-based QMD simulation involving 16 661 atoms is performed on the Blue Gene/Q to study on-demand production of hydrogen gas from water using LiAl alloy particles. As an example of the recombine phase, LDC-DFT electronic structures are used as a basis set to describe global photoexcitation dynamics with nonadiabatic QMD (NAQMD) and kinetic Monte Carlo (KMC) methods. The NAQMD simulations are based on the linear response time-dependent density functional theory to describe electronic excited states and a surface-hopping approach to describe transitions between the excited states. A series of techniques are employed for efficiently calculating the long-range exact exchange correction and excited-state forces. The NAQMD trajectories are analyzed to extract the rates of various excitonic processes, which are then used in KMC simulation to study the dynamics of the global exciton flow network. This has allowed the study of large-scale photoexcitation dynamics in 6400-atom amorphous molecular solid, reaching the experimental time scales. PMID:24832337

  9. A divide-conquer-recombine algorithmic paradigm for large spatiotemporal quantum molecular dynamics simulations

    Science.gov (United States)

    Shimojo, Fuyuki; Hattori, Shinnosuke; Kalia, Rajiv K.; Kunaseth, Manaschai; Mou, Weiwei; Nakano, Aiichiro; Nomura, Ken-ichi; Ohmura, Satoshi; Rajak, Pankaj; Shimamura, Kohei; Vashishta, Priya

    2014-05-01

    We introduce an extension of the divide-and-conquer (DC) algorithmic paradigm called divide-conquer-recombine (DCR) to perform large quantum molecular dynamics (QMD) simulations on massively parallel supercomputers, in which interatomic forces are computed quantum mechanically in the framework of density functional theory (DFT). In DCR, the DC phase constructs globally informed, overlapping local-domain solutions, which in the recombine phase are synthesized into a global solution encompassing large spatiotemporal scales. For the DC phase, we design a lean divide-and-conquer (LDC) DFT algorithm, which significantly reduces the prefactor of the O(N) computational cost for N electrons by applying a density-adaptive boundary condition at the peripheries of the DC domains. Our globally scalable and locally efficient solver is based on a hybrid real-reciprocal space approach that combines: (1) a highly scalable real-space multigrid to represent the global charge density; and (2) a numerically efficient plane-wave basis for local electronic wave functions and charge density within each domain. Hybrid space-band decomposition is used to implement the LDC-DFT algorithm on parallel computers. A benchmark test on an IBM Blue Gene/Q computer exhibits an isogranular parallel efficiency of 0.984 on 786 432 cores for a 50.3 106-atom SiC system. As a test of production runs, LDC-DFT-based QMD simulation involving 16 661 atoms is performed on the Blue Gene/Q to study on-demand production of hydrogen gas from water using LiAl alloy particles. As an example of the recombine phase, LDC-DFT electronic structures are used as a basis set to describe global photoexcitation dynamics with nonadiabatic QMD (NAQMD) and kinetic Monte Carlo (KMC) methods. The NAQMD simulations are based on the linear response time-dependent density functional theory to describe electronic excited states and a surface-hopping approach to describe transitions between the excited states. A series of techniques are employed for efficiently calculating the long-range exact exchange correction and excited-state forces. The NAQMD trajectories are analyzed to extract the rates of various excitonic processes, which are then used in KMC simulation to study the dynamics of the global exciton flow network. This has allowed the study of large-scale photoexcitation dynamics in 6400-atom amorphous molecular solid, reaching the experimental time scales.

  10. Digital divide and digital opportunity: Comparison, analysis and strategies for sustainable development in developing nations

    International Nuclear Information System (INIS)

    The world is witnessing a new digital economic order which may be quantified by the diffusion of information technology and globalization process. The current information technology gap (digital divide) between developed countries and developing countries is huge. Improvements in information technology (measured by the digital opportunity index) usually open up an opportunity for national/regional growth and development. There is a need for scientific investigation on the digital divide, digital opportunity index and their consequences. This paper presents a critical analysis of existing digital divide and its trends, it also investigates the relationship between the digital divide and the digital opportunity index. A mathematical model based on analysis of the growing digital divide is presented as a possible tool for combating and eradicate the digital divide gap which is only possible if developing and poor nations take advantage of the digital opportunities that can transform them into global competitive partners in digital knowledge economy. (author)

  11. Digital Divide amongst Urban Youths in Malaysia – Myth or Reality?

    OpenAIRE

    Patrick C-H Soh; Yap Liang Yan; Tze San Ong; Boon Heng Teh

    2012-01-01

    The Digital Divide is an important issue with serious consequences, both for the individuals affected and society. With 90% of youths in urban areas using the Internet, there is a myth that the Digital Divide no longer exists amongst urban youths. Based on a random survey of 1639 youths, this study analyses the possibility of a digital divide along ethnic lines in Malaysia.. Findings indicate there are significant ethnic-based differences in home PC ownership and Internet connection. There ar...

  12. The effect of divided attention on false memory depends on how memory is tested.

    OpenAIRE

    Stephen A Dewhurst; Barry, Christopher; Swannell, Ellen R.; Holmes, Selina J.; Bathurst, Gemma J.

    2007-01-01

    In three experiments, we investigated the effects of divided attention on false memory, using the Deese/Roediger-McDermott (DRM) paradigm. In Experiments 1 and 2, participants studied six DRM lists with full attention and six in one of two divided-attention conditions (random number generation or digit monitoring). Both divided-attention conditions increased false recall of related words (Experiment 1) but reduced false recognition (Experiment 2). These results were confirmed in Experiment 3,...

  13. HIGH VOLTAGE SMALL – SIZED ALTERNATIVE CURRENT RESISTIVE DIVIDERS FROM MICROWIRE

    Directory of Open Access Journals (Sweden)

    Berzan V.P.

    2011-04-01

    Full Text Available The paper discusses the design parameters and characteristics of the new product, the resistive voltage divider produced from microwire for measuring high-voltage alternating current. Resistive dividers are designed for use in AC circuits and power-frequency electric traction network traffic. Dividers have smaller mass-dimensional size compared with the measuring voltage transformers and higher accuracy class 0.2 at a fixed frequency.

  14. Unobtrusive Monitoring of Divided Attention in a Cognitive Health Coaching Intervention for the Elderly

    OpenAIRE

    McKanna, James A.; Pavel, Misha; Jimison, Holly

    2010-01-01

    Assessment of cognitive functionality is an important aspect of care for elders. Unfortunately, few tools exist to measure divided attention, the ability to allocate attention to different aspects of tasks. An accurate determination of divided attention would allow inference of generalized cognitive decline, as well as providing a quantifiable indicator of an important component of driving skill. We propose a new method for determining relative divided attention ability through unobtrusive mo...

  15. Zones of silence: A framework beyond the digital divide (originally published in May 2006)

    OpenAIRE

    Potter, Amelia Bryne

    2007-01-01

    There is no doubt that much digital divide work including connectivity initiatives, technology transfer programs, and other projects is done with good intention. Yet, as has been widely recognized, the conceptual framework of the digital divide is limiting. The language of the digital divide not only places people into simplistic have/have not categories, making assumptions about the solution to information poverty with little attention to local contexts, its logic also continues a ...

  16. A Novel Microwave Tunable Band-Pass Filter Integrated Power Divider Based on Liquid Crystal

    OpenAIRE

    Yupeng Liu; Di Jiang; Lei Xia; Ruimin Xu

    2015-01-01

    This paper proposes a novel microwave continuous adjustable band-pass filter integrated power divider based on nematic liquid crystals (LCs). The proposed power divider uses liquid crystal (LC) as the dielectric material. It can realize phase shift by changing the dielectric anisotropy, when biasing the high anisotropy nematic liquid crystal. It is mainly used in microwave frequencies. It has a large number of advantages compared to conventional filter integrated power divider, such as low lo...

  17. A low-power digital frequency divider for system-on-a-chip applications

    KAUST Repository

    Omran, Hesham

    2011-08-01

    In this paper, an idea for a new frequency divider architecture is proposed. The divider is based on a coarse-fine architecture. The coarse block operates at a low frequency to save power consumption and it selectively enables the fine block which operates at the high input frequency. The proposed divider has the advantages of synchronous divider, but with lower power consumption and higher operation speed. The design can achieve a wide division range with a minor effect on power consumption and speed. The architecture was implemented on a complex programmable logic device (CPLD) to verify its operation. Experimental measurements validate system operation with power reduction greater than 40%. © 2011 IEEE.

  18. Divided Plato

    International Nuclear Information System (INIS)

    His experience as nuclear physicist, univerity professor, and research promoter recommend the author as a partner in the discussion on progress. He shows what kind of man a scientist is, which motivations he has, what he can do. He explains how it is possible even today to find simple ways to the unknown, how the new, the unforeseeable comes into being. And he gives stimuli to and examples of the work of scientists, his responsibility and his contribution to the application of knowledge, - for instance in the field of nuclear energy - and of the contributions of science to problems of economy and politics. (orig.)

  19. Mobility Divides

    DEFF Research Database (Denmark)

    Jensen, Ole B.

    are increasingly becoming ‘second nature’ but also expressions of power, exclusion, and difference. In this talk I will be applying a perspective of ‘mobile situationism’ illustrating how mobile everyday life practices are staged ‘from above’ in planning and policy frameworks, design codes and...

  20. Divided Uncertainty

    DEFF Research Database (Denmark)

    Frederiksen, Morten

    Trust as a concept is inherently intertwined with institutional concepts. Trust, according to contemporary research, may be directed at both people and institutions, trust may in itself be an institution, and the influence of institutions may affect both trust in other people and trust in other i...

  1. Dividing Arizona

    Science.gov (United States)

    Finkel, Ed

    2010-01-01

    Amid all the national attention on Arizona these past few months, largely due to Senate Bill 1070 empowering police to take "reasonable" steps to verify the immigration status of criminal suspects, the state's K12 district administrators have been wrestling with a unique segregation issue, as well. Over the past two years, all districts have

  2. Labor divided

    OpenAIRE

    Oude Nijhuis, Dennie

    2009-01-01

    This book compares the process of postwar welfare state development in the Netherlands and the United Kingdom by analyzing the role of the labor union movement in the creation and expansion of social policies. It argues for a fundamental reinterpretation of the role of organized labor in welfare state development. It emphasizes that welfare state development is mainly about redistribution of income and risk within the worker category. Based on this premises, the book has set out to understand...

  3. Bridging the Second Digital Divide: What Can Sociologists of Education Contribute?

    Science.gov (United States)

    Natriello, Gary

    2001-01-01

    Discusses the importance of how the divide in access is approached and the problems in addressing both digital divides (access and computer use). Argues that sociologists of education have an important role to play in this issue and describes that role. Includes references. (CMK)

  4. Great Divides: The Cultural, Cognitive, and Social Bases of the Global Subordination of Women

    Science.gov (United States)

    Epstein, Cynthia Fuchs

    2007-01-01

    Categorization based on sex is the most basic social divide. It is the organizational basis of most major institutions, including the division of labor in the home, the workforce, politics, and religion. Globally, women's gendered roles are regarded as subordinate to men's. The gender divide enforces women's roles in reproduction and support…

  5. 76 FR 55643 - Helena National Forest; Montana; Divide Travel Plan EIS

    Science.gov (United States)

    2011-09-08

    ... Forest Service Helena National Forest; Montana; Divide Travel Plan EIS AGENCY: Forest Service, USDA... the existing motorized public access routes and prohibitions within the Divide travel planning area for wheeled and over-snow motorized vehicles. Consistent with Forest Service travel...

  6. Is the Serpent Eating Its Tail? The Digital Divide and African Americans

    Science.gov (United States)

    Horton, Jacqueline

    2004-01-01

    The Digital Divide is alive and well in America. What this means is the technology haves and the have-nots are continually growing further apart. Due to the pace of change in the field of computer technology, this divide widens faster in less time. Playing catch-up becomes an increasingly more difficult game to endure, with the government, public,

  7. The Divide between Diversity Training and Diversity Education: Integrating Best Practices

    Science.gov (United States)

    King, Eden B.; Gulick, Lisa M. V.; Avery, Derek R.

    2010-01-01

    The fields of diversity training and diversity education have developed in a disconnected manner. This divide ensures that each field advances slowly and with narrow focus. The authors argue here that the divide should be bridged with attention to the best practices that diversity training and diversity education offer. By integrating the best…

  8. Healing the Physical/Spiritual Divide through a Holistic and Hermeneutic Approach to Education

    Science.gov (United States)

    Webster, R. Scott

    2013-01-01

    In this special edition of the journal, attention is being given to the two dimensions of spirituality and physicality. In this particular paper I argue that there is an unhelpful divide that is often assumed to exist between these two dimensions and that this divide can be transcended or "healed" through a holistic and hermeneutic approach to

  9. From Digital Divides to Digital Inequality -- The Emerging Digital Inequality in the Norwegian Unitarian School

    Science.gov (United States)

    Krumsvik, Rune J.

    2008-01-01

    This position paper highlights existing and emerging, prospective digital divides in Norwegian schools and asks whether we are now moving from traditional digital divides to digital inequality in our digitized society and schools. Despite very good technology density in Norwegian society and schools in general, there is the reason to pay attention

  10. Essays on the Digital Divide--Explorations through Global, National and Individual Lenses

    Science.gov (United States)

    Skaletsky, Maria

    2013-01-01

    The Digital Divide has emerged as an important research and policy issue during the past thirty years. The divide exists at different levels, such as global, regional and individual levels. While extensive research already exists on this subject, the complexity of the issue presents opportunities for further research. In particular, there is ample

  11. The Inequities of the Digital Divide: Is E-Learning a Solution?

    Science.gov (United States)

    Journell, Wayne

    2007-01-01

    This article addresses the continuing digital divide in public education, one that defines itself largely along geographic, socioeconomic, and cultural lines. The article refutes the idea that the digital divide is dwindling due to increasing access to technology within the United States, instead focusing on digital literacy and cultural barriers

  12. Understanding the Complex Dimensions of the Digital Divide: Lessons Learned in the Alaskan Arctic

    Science.gov (United States)

    Subramony, Deepak Prem

    2007-01-01

    An ethnographic case study of Inupiat Eskimo in the Alaskan Arctic has provided insights into the complex nature of the sociological issues surrounding equitable access to technology tools and skills, which are referred to as the digital divide. These people can overcome the digital divide if they get the basic ready access to hardware and

  13. Computer and Video Games in Family Life: The Digital Divide as a Resource in Intergenerational Interactions

    Science.gov (United States)

    Aarsand, Pal Andre

    2007-01-01

    In this ethnographic study of family life, intergenerational video and computer game activities were videotaped and analysed. Both children and adults invoked the notion of a digital divide, i.e. a generation gap between those who master and do not master digital technology. It is argued that the digital divide was exploited by the children to

  14. The Digital Divide as Cultural Practice: A Cognitive Anthropological Exploration of Japan as an "Information Society"

    Science.gov (United States)

    Kimura, Tadamasa

    2010-01-01

    The objective of this dissertation is to explore the socio-cultural contextualization of the digital divide in Japanese society. I undertake this task by developing a theoretical and methodological framework based on the notion of "culture as models," while explicating the cultural dimensions of the digital divide and the dynamics of ICTs,

  15. The Correlates of the Digital Divide and Their Impact on College Student Learning

    Science.gov (United States)

    Tien, Flora F.; Fu, Tsu-Tan

    2008-01-01

    By focusing on two dimensions of the digital divide--computer use and computer knowledge, this study explores four research questions: (1) What are the undergraduates doing with the computers they use at colleges? (2) How do undergraduates perform in regard to computer knowledge and skills? (3) With what is the digital divide among college

  16. The Role of IT Literacy in Defining Digital Divide Policy Needs

    Science.gov (United States)

    Ferro, Enrico; Helbig, Natalie C.; Gil-Garcia, J. Ramon

    2011-01-01

    This article expands our current understanding of the digital divide by examining differences in individuals' IT skills acquisition. In the last two decades scholars have gradually refined the conceptualization of the digital divide, moving from a dichotomous model mainly based on access, to a multidimensional model accounting for differences in

  17. A Study to Examine the Digital Divide Factors: Jammu and Kashmir Perspective

    Directory of Open Access Journals (Sweden)

    Preeti Dubey

    2011-01-01

    Full Text Available Digital divide refers to a substantial asymmetry between twoor more populations in the distribution and effective use ofinformation and communication resources. Despite the boomin the availability of access to communication resources sincethe beginning of the 1990s, the divide is deepening and thedifferences in the usage of communication resources betweencountries and regions intensifying. Even though the ruralareas have benefitted to some extent from the boom in accessto communication resources, the regional divide is morepronounced within the developing countries. Factorsinfluencing digital divide vary from region to region. In anattempt to find the factors responsible for the digital divide inJammu and Kashmir region, a pilot survey was conducted.This paper reports on the results of this pilot study. The studywas conducted by floating questionnaires and by interviewingpeople of rural as well as urban areas. Questions were relatedto internet access, its usage, problems faced in its use etc. Onanalysis of data, many other observations other than thedigital divide factors have been reported. It was found duringthe study that the government is providing facilities forinternet access but awareness of these initiatives is stilllacking. People residing in rural areas are hesitant to useinternet due to lack of English language proficiency. Thispaper is a result of the pilot survey to examine the factorsresponsible for the regional digital divide and will help insuggesting methods to bridge this divide.

  18. Behavior of $F(R)$ gravity around a crossing of the phantom divide

    OpenAIRE

    Bamba, Kazuharu

    2009-01-01

    We study a model of $F(R)$ gravity in which a crossing of the phantom divide can be realized. In particular, we demonstrate the behavior of $F(R)$ gravity around a crossing of the phantom divide by taking into account the presence of cold dark matter.

  19. Combination N-Way Power Divider/Combiner and Noninvasive Reflected Power Detection

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — An N-way RF/microwave power divider/combiner utilizes one input and N outputs, or conversely N inputs and one output to divide (or combine) RF/microwave power while...

  20. All-Metal-Waveguide Power Divider with High Power-Combining Efficiency

    Science.gov (United States)

    Zhang, Fan; Song, Kaijun; Fan, Maoyu; Fan, Yong

    2016-03-01

    A four-way all-metal-waveguide power divider has been presented and analyzed in this paper. A metal matching cylinder and a transition waveguide are applied to implement wide impedance matching from the input port to the four output ports. A simple equivalent-circuit model for this power-dividing structure has been developed. Moreover, the theoretical power-handling capability of the presented power-dividing structure has also been investigated. To verify the validity of the proposed structure, a four-way power divider at W-band has been fabricated with conventional machining. The measured return loss is greater than 14.5 dB from 82 GHz to 107 GHz. The measured insertion loss of the four-way all-metal-waveguide power divider is about 6.5 dB, which corresponds to a power-combining efficiency of 89 %.