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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. 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

  3. 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.)

  4. 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.

  5. 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

  6. 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.

  7. 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.

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

    OpenAIRE

    Broukal, J.; R. Kužel

    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.

  9. 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

  10. Power Divider

    OpenAIRE

    Chen, Yu Christine; Dhople, Sairaj

    2015-01-01

    This paper derives analytical closed-form expressions that uncover the contributions of nodal active- and reactive-power injections to the active- and reactive-power flows on transmission lines in an AC electrical network. Paying due homage to current- and voltage-divider laws that are similar in spirit, we baptize these as the power divider laws. Derived from a circuit-theoretic examination of AC power-flow expressions, the constitution of the power divider laws reflects th...

  11. 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.

  12. 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...

  13. 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, Berç; 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

  14. 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.

  15. 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

  16. 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.

  17. 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.)

  18. 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

  19. Effect of a divided wetwell on heat removal capability of the water wall type passive capability of the water wall type passive containment cooling system

    International Nuclear Information System (INIS)

    A water wall type containment cooling system, which has a colling pool outside the suppression pool, is one of the passive containment cooling systems (PCCSs). To improve its heat removel capability, we have proposed a divided wetwell (gas phase space in the suppression chamber), which separates the wetwell space into a high steam partial pressure region (first wetwell) and high noncondensable gas partial pressure region (second wetwell). We experimentally examined the thermal hydraulic behavior of the wall type PCCS which applies the divided wetwell. By cooling the second wetwell and condensing the steams which flowed from the first wetwell into the second wetwell, noncondensable gas in the first wetwell was discharged to the second wetwell. In the first wetwell, the saturated steam pressure increased. After the noncondensable gas was fully discharged to the second wetwell, the first wetwell temperature came within 1degC of the suppression pool surface temperature. Therefore, attainable temperatures of the first wetwell and the suppression pool water increased for the same pressure of the primary containment vessel. Consequently, the time-integrated released heat to the outer pool was 70% larger than the non-divided case due to increase of the temperature difference between the suppression pool and outer pool. (author)

  20. 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.

  1. A comprehensive study of polysilicon resistors for CMOS ULSI applications

    Science.gov (United States)

    Chuang, Hung-Ming; Thei, Kong-Beng; Tsai, Sheng-Fu; Lu, Chun-Tsen; Liao, Xin-Da; Lee, Kuan-Ming; Chen, Hon-Rung; Liu, Wen-Chau

    2003-04-01

    The characteristics of polysilicon resistors for CMOS ULSI applications have been investigated. Based on the presented sub-quarter micron CMOS borderless contact, both n + and p + polysilicon resistors with Ti- and Co-silicide self-aligned process are used at the ends of each resistor. A simple and useful model is proposed to analyse and calculate some important parameters of polysilicon resistors including electrical delta W(? W), interface resistance Rinterface, and pure sheet resistance Rpure. Furthermore, the characteristics of voltage-coefficient resistor, temperature-coefficient resistor, and resistor mismatching are also studied. An interesting sine-wave voltage-dependent characteristic due to the strong relation to the Rinterface has been modelled in this paper. This approach can substantially help engineers in designing and fabricating the precise polysilicon resistors in sub-quarter micron CMOS ULSI technology.

  2. 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)

  3. Stochastic Resonance Induced by Dichotomous Resistor in an Electric Circuit

    International Nuclear Information System (INIS)

    An electric circuit with dichotomous resistor is investigated. It is shown that the amplitude of the average electric current washing the resistor represents the phenomenon of stochastic resonance, which is the response as a function of the correlation time of the dichotomous resistor.

  4. 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.

  5. 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.

  6. 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)

  7. 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.

  8. Precision resistors for AC and DC

    International Nuclear Information System (INIS)

    Precision resistors of special construction with nominal values of 1000 ? are described. They are used in the PTB as AC-DC transfer standards for the determination of the Sl-unit Ohm based on the Sl-unit Farad realized by the method of Thompson and Lampard. The difference between the resistance values at AC and at DC are calculated with a relative uncertainty (1 sigma) of +- 0.6 x 10-9. (orig.)

  9. Correlated percolation and the correlated resistor network

    OpenAIRE

    Bastiaansen, Paul J. M.; Knops, Hubert J. F.

    1996-01-01

    We present some exact results on percolation properties of the Ising model, when the range of the percolating bonds is larger than nearest-neighbors. We show that for a percolation range to next-nearest neighbors the percolation threshold Tp is still equal to the Ising critical temperature Tc, and present the phase diagram for this type of percolation. In addition, we present Monte Carlo calculations of the finite size behavior of the correlated resistor network defined on t...

  10. Regulating resistor and interruptor for the toroidal field system on the TEXT Tokamak development tests

    International Nuclear Information System (INIS)

    Tests on two prototype electrolytic resistors-interrupters demonstrated the practicality of this approach to interrupting and regulating high DC currents of modest voltage as they occur, for instance, in the toroidal field circuit of a tokamak fed by homopolar machines. NaOH in water solution is suitable as an electrolyte in conjunction with mild steel electrodes. Suitable materials for insulation, gaskets, etc. were established and other materials which are in common engineering usage were found to be incompatible with this particular application. The relationship given in formula together with consideration of average heating per shot permits to dimension the resistors in a conservative manner and has been used for the basic design of the TEXT resistors

  11. 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

  12. 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 current–voltage (I–V) 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 I–V 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

  13. 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)

  14. Variable thermal resistor based on self-powered Peltier effect

    International Nuclear Information System (INIS)

    Heat flow through a thermoelectric material or device can be varied by an electrical resistor connected in parallel to it. This phenomenon is exploited to design a novel thermal component-variable thermal resistor. The theoretical background to this novel application is provided and an experimental result to demonstrate its feasibility is reported. (fast track communication)

  15. 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.

  16. Correlated percolation and the correlated resistor network

    CERN Document Server

    Bastiaansen, P J M; Bastiaansen, Paul J. M.; Knops, Hubert J. F.

    1996-01-01

    We present some exact results on percolation properties of the Ising model, when the range of the percolating bonds is larger than nearest-neighbors. We show that for a percolation range to next-nearest neighbors the percolation threshold Tp is still equal to the Ising critical temperature Tc, and present the phase diagram for this type of percolation. In addition, we present Monte Carlo calculations of the finite size behavior of the correlated resistor network defined on the Ising model. The thermal exponent t of the conductivity that follows from it is found to be t = 0.2000 +- 0.0007. We observe no corrections to scaling in its finite size behavior.

  17. Bifurcation diagrams in MOS-NDR frequency divider circuits

    OpenAIRE

    Núñez, Juan; Avedillo, M. J.; Quintana, J. M.

    2012-01-01

    The behavior of a circuit able to implement frequency division is studied. It is composed of a block with an I-V characteristic exhibiting Negative Differential Resistance (NDR) built from MOS transistors plus an inductor and a resistor. Frequency division is obtained from the period adding sequences which appear in its bifurcation diagram. The analyzed circuit is an “all MOS” version of one previously reported which uses Resonant Tunneling Diodes (RTDs). The results show that the dividing ra...

  18. Spectral fluctuation dividing for efficient wavenumber selection: application to estimation of water and drug content in granules using near infrared spectroscopy.

    Science.gov (United States)

    Miyano, Takuya; Kano, Manabu; Tanabe, Hideaki; Nakagawa, Hiroshi; Watanabe, Tomoyuki; Minami, Hidemi

    2014-11-20

    In process analytical technology (PAT) based on near infrared (NIR) spectroscopy, wavenumber selection is crucial to develop an accurate and robust calibration model. The present research proposes new efficient spectral dividing and wavenumber selection methods to significantly reduce the computational load required by conventional wavenumber selection methods such as interval partial least squares (iPLS). The proposed method, named spectral fluctuation dividing (SFD), divides a whole spectrum into multiple spectral intervals at local minimum points of the spectral fluctuation profile, which consists of the standard deviation of absorbance at each wavenumber in a calibration set. SFD is combined with PLS (SFD-PLS) to select the spectral intervals at which input variables have significant influence on a target response. The usefulness of SFD-PLS was demonstrated through its application to the problems of estimating water and drug content in granules. PLS models based on SFD-PLS achieved higher estimation accuracy than those based on conventional methods including iPLS, PLS-beta, and variable influence on projection (VIP). In addition, SFD-PLS was more than 10 times faster than the conventional variable selection methods including PLS-beta and VIP; in particular, SFD-PLS was more than 25 times faster than iPLS. Consequently, the proposed SFD-PLS is a promising wavenumber selection method. PMID:25218183

  19. 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.

  20. 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.

  1. Dynamic Systems Model for Filamentary Mem-Resistors

    OpenAIRE

    Mouttet, Blaise

    2011-01-01

    A dynamic systems model is proposed describing memory resistors which include a filament conductive bridge. In this model the system state is defined by both a dynamic tunneling barrier (associated with the filament-electrode gap) and a dynamic Schottky barrier (associated with the electron depletion width surrounding the filament-electrode gap). A general model is formulated which may be applicable to many different forms of memory resistor materials. The frequency response...

  2. Free-standing silicon micro machined resistors from (110) substrate

    International Nuclear Information System (INIS)

    A simple process to obtain silicon planes released from the substrate and provided with large area pads for ohmic contacts is described. Resistors 500 ?m long with a 40 ?m x 1 ?m cross section were obtained. Resistance measurements showed that the current flows in a reduced cross section, probably owing to the presence of a superficial depletion layer. Preliminary magnetoresistance measurements are presented. Reduction of the resistor cross section can be obtained by thermal oxidation

  3. Burden resistor selection in current transformers for low power applications

    OpenAIRE

    Conesa Roca, Alfons; Bargalló Perpiñá, Ramón; Velasco Quesada, Guillermo; Román Lumbreras, Manuel

    2014-01-01

    In order to sense AC current with electric isolation in high frequency switching power converters the most simple and low cost solution is to consider a current transformer with a burden resistor. But burden resistor selection is not a simple task because involves a lot of considerations that affect the output voltage and its signal-to-noise ratio and the bandwidth of the measure. In this paper, considering the basic equations of the transformer and applying the Laplace Transformation is obta...

  4. Experimental Research on Properties of Materials of Grounding Resistor

    OpenAIRE

    He Da-Jiang; Xiao-Jing; Yang Heng-Ling; Qu-Jun; Liu Liang-Yuan

    2013-01-01

    In this study, we have a experimental research on properties of materials of grounding resistor. Experiment test of the grounding resistor in the state of analog ground fault have been done, the performance parameters on the mechanics, thermal and electrical of alloy materials with different kinds and different specification have been got. The performance and its character of alloy materials have been grasped in the state of analog ground fault by analysis and processing. The research results...

  5. 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...

  6. 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.

  7. 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

  8. 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.

  9. 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…

  10. Divide and Conquer

    OpenAIRE

    Posner, Eric A.; Spier, Kathryn E.; Vermeule, Cornelius Adrian

    2010-01-01

    The maxim “divide and conquer” (divide et impera) is invoked frequently in law, history, and politics, but often in a loose or undertheorized way. We suggest that the maxim is a placeholder for a complex of ideas related by a family resemblance, but differing in their details, mechanisms and implications. We provide an analytic taxonomy of divide and conquer mechanisms in the settings of a Stag Hunt Game and an indefinitely-repeated Prisoners' Dilemma. A number of applications are considered,...

  11. 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

  12. 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)

  13. 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.

  14. Electrochemical Migration on Electronic Chip Resistors in Chloride Environments

    DEFF Research Database (Denmark)

    Minzari, Daniel; Jellesen, Morten Stendahl

    2009-01-01

    Electrochemical migration behavior of end terminals on ceramic chip resistors (CCRs) was studied using a novel experimental setup in varying sodium chloride concentrations from 0 to 1000 ppm. The chip resistor used for the investigation was 10-k? CCR size 0805 with end terminals made of 97Sn3Pb 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 rate of the Sn and stability of Sn ions in the solution layer play a significant role in the formation of dendrites, which is controlled by chloride concentration and potential bias. Morphology, composition, and resistance of the dendrites were dependent on chloride concentration and potential.

  15. 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

  16. 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 ...

  17. 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)

  18. 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.

  19. 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

  20. 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.

  1. 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...

  2. Air-cooled fast discharge resistors for ITER magnets

    International Nuclear Information System (INIS)

    The ITER superconducting magnets will store up to 50 GJ of magnetic energy per operation cycle. In case of coil quench the energy stored in the coils must be extracted rapidly with a time constant from 7.5 to 14 s. It will be achieved by fast discharge resistors (FDR) normally bridged by circuit breakers and inserted in series with the superconducting coils. The fast discharge of the coils results practically in adiabatic heating of the resistive elements up to 200-300 deg. C. The resistors need to be cooled to the initial temperature over 6-8 h. Natural air circulation is proposed as a cooling method. In order to simulate the temperature response of the resistors to energy released in the resistive plates and to demonstrate their cooling capability within the required time by natural air circulation the numerical model of the resistor cooling circuit has been developed. As the calculations have shown, the developed FDR cooling system based on cooling by natural air circulation is capable of providing the required temperature operation regime of FDRs, but the supply channels are to be optimized so that the cooling time does not exceed the permissible one.

  3. 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)

  4. 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.

  5. Divide and Pacify

    DEFF Research Database (Denmark)

    Vanhuysse, Pieter

    transitions from communism to market democracy in the 1990s have been remarkably peaceful. This book proposes a new explanation for this unexpected political quiescence. It shows how reforming governments in Poland, Hungary and the Czech Republic have been able to prevent massive waves of strikes and protests...... point the question…: why did widespread early predictions that post-communist democracies would be convulsed by Latin American-style waves of social protest prove so wrong? ... Divide and Pacify develops a coherent, wide-ranging and persuasive re-interpretation of the politics of post...... clearly understood the potentially explosive situation and strategically adopted social policies to ‘divide and pacify’ the working population. Thus Hungary and Poland, amid a steep transformational recession, adopted generous pension policies which allowed an important share of the working population to...

  6. 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...

  7. 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...

  8. 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...

  9. 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...

  10. The electromagnetic "memory" of a dc-conducting resistor

    CERN Document Server

    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, not with a single respective classical state-variable, -- either current or voltage. The circuit-theory point of view that a resistor has no electromagnetic memory is accepted, but the necessarily involved (in view of the field argument) capacitance and inductiveness are argued then also not be associated with any memory. The mutually completing circuit and physical arguments are presented in the form of dialog between a physicist and an electrical engineer. A teacher can find the work be pedagogically useful.

  11. 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 k?, 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.

  12. Voltage controlled resistor using quasi-floating-gate MOSFETs

    OpenAIRE

    Susheel Sharma

    2013-01-01

    A voltage controlled resistor (VCR) using quasi-floating-gate MOSFETs (QFGMOS) suitable for low voltage applications is presented. The performance of the VCR implemented with QFGMOS is compared with its floating-gate MOSFET (FGMOS) version. It was found that QFGMOS offers better performance than FGMOS in terms of frequency response, offsets and chip area. The VCR using QFGMOS offers high bandwidth and low power dissipation and yields high value of resistance as compared to its FGMOS counterpa...

  13. Spin dependent trapping in a polycrystalline silicon integrated circuit resistor

    International Nuclear Information System (INIS)

    Spin dependent trapping of majority carriers at trivalent silicon centers in the grain boundaries of a polycrystalline silicon integrated circuit resistor has been observed. The phenomenon has been studied both in a silicon bicrystal and in thin-film polycrystalline silicon with essentially identical results. This not only identifies the trapping center responsible for the large barriers observed at silicon grain boundaries, but also demonstrates that the technique has the sensitivity required to work with actual microelectronic devices

  14. TaN resistor process development and integration.

    Energy Technology Data Exchange (ETDEWEB)

    Romero, Kathleen (LMATA, Albuquerque, NM); Martinez, Marino John; Clevenger, Jascinda; Austin, Franklin H., IV (, LMATA, Albuquerque, NM); Sullivan, Charles Thomas; Wolfley, Steven L.; Patrizi, Gary A.; Vigil, Pablita S. (LMATA, Albuquerque, NM); Grine, Alejandro J.

    2010-05-01

    This paper describes the development and implementation of an integrated resistor process based on reactively sputtered tantalum nitride. Image reversal lithography was shown to be a superior method for liftoff patterning of these films. The results of a response surface DOE for the sputter deposition of the films are discussed. Several approaches to stabilization baking were examined and the advantages of the hot plate method are shown. In support of a new capability to produce special-purpose HBT-based Small-Scale Integrated Circuits (SSICs), we developed our existing TaN resistor process, designed for research prototyping, into one with greater maturity and robustness. Included in this work was the migration of our TaN deposition process from a research-oriented tool to a tool more suitable for production. Also included was implementation and optimization of a liftoff process for the sputtered TaN to avoid the complicating effects of subtractive etching over potentially sensitive surfaces. Finally, the method and conditions for stabilization baking of the resistors was experimentally determined to complete the full implementation of the resistor module. Much of the work to be described involves the migration between sputter deposition tools - from a Kurt J. Lesker CMS-18 to a Denton Discovery 550. Though they use nominally the same deposition technique (reactive sputtering of Ta with N{sup +} in a RF-excited Ar plasma), they differ substantially in their design and produce clearly different results in terms of resistivity, conformity of the film and the difference between as-deposited and stabilized films. We will describe the design of and results from the design of experiments (DOE)-based method of process optimization on the new tool and compare this to what had been used on the old tool.

  15. 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.

  16. 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.

  17. 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

  18. 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)

  19. 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

  20. 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).

  1. 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.

  2. Universality and superuniversality of multifractals in nonlinear resistor networks

    International Nuclear Information System (INIS)

    The multifractal function f(?) is generalized to describe noisy nonlinear random resistor networks. An approximant function for the family of noise exponents is introduced that provides a good description of real percolative systems for strong nonlinearities. By mapping from this family to the multifractal function, one can approximate the latter. A scale transformation of ? in the approximation makes the multifractal function universal for all nonlinearities and by applying an additional transformation, this function becomes superuniversal, i.e., independent of the dimension. The universality is demonstrated for the Mandelbrot-Given structure and the implications of these results are discussed on real percolative systems

  3. Flory theory for conductivity of random resistor networks

    OpenAIRE

    Family, F.; Coniglio, A.

    1985-01-01

    We develop a Flory theory for the problem of conductivity in a d-dimensional random resistor network. We find that the conductivity exponent t is related to the fractal dimensionality df according to the Alexander-Orbach conjecture t = d - 2 + df/2, where consistently with Flory theory df = (d + 2)/2 for percolation and df = 2(d + 2)/5 for lattice animals. The results are in excellent agreement with the numerical estimates of t for percolation and in fair agreement for lattice animals.

  4. 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 tha...

  5. 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.

  6. 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.

  7. 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, commerci...

  8. 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)

  9. 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.

  10. 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

  11. Set, Reset, and Retention Times for Ionic and Filamentary Mem-Resistors

    OpenAIRE

    Mouttet, Blaise

    2011-01-01

    A dynamic systems model has previously been proposed for mem-resistors based on a driven damped harmonic oscillator differential equation describing electron and ionic depletion widths in a thin semiconductor film. This paper derives equations for set, reset, and retention times based on the previously proposed model. Keywords- mem-resistor, RRAM, ReRAM

  12. Stationary Regime of Random Resistor Networks Under Biased Percolation

    CERN Document Server

    Pennetta, C; Alfinito, E; Trefan, G

    2002-01-01

    The state of a 2-D random resistor network, resulting from the simultaneous evolutions of two competing biased percolations, is studied in a wide range of bias values. Monte Carlo simulations show that when the external current $I$ is below the threshold value for electrical breakdown, the network reaches a steady state with a nonlinear current-voltage characteristic. The properties of this nonlinear regime are investigated as a function of different model parameters. A scaling relation is found between $/_0$ and $I/I_0$, where $$ is the average resistance, $_0$ the linear regime resistance and $I_0$ the threshold value for the onset of nonlinearity. The scaling exponent is found to be independent of the model parameters. A similar scaling behavior is also found for the relative variance of resistance fluctuations. These results compare well with resistance measurements in composite materials performed in the Joule regime up to breakdown.

  13. "Weak quantum chaos" and its resistor network modeling.

    Science.gov (United States)

    Stotland, Alexander; Pecora, Louis M; Cohen, Doron

    2011-06-01

    Weakly chaotic or weakly interacting systems have a wide regime where the common random matrix theory modeling does not apply. As an example we consider cold atoms in a nearly integrable optical billiard with a displaceable wall (piston). The motion is completely chaotic but with a small Lyapunov exponent. The Hamiltonian matrix does not look like one taken from a Gaussian ensemble, but rather it is very sparse and textured. This can be characterized by parameters s and g which reflect the percentage of large elements and their connectivity, respectively. For g we use a resistor network calculation that has a direct relation to the semilinear response characteristics of the system, hence leading to a prediction regarding the energy absorption rate of cold atoms in optical billiards with vibrating walls. PMID:21797470

  14. Applications of the superconducting lossless resistor in electric power systems

    Science.gov (United States)

    Qian, Ping; Chen, Ji-yan; Hua, Rong; Chen, Zhongming

    2003-04-01

    The main features and some very useful applications of the superconducting lossless resistor (LLR) in electric power systems are introduced in this paper. According our opinion, there are two different kinds of LLR, i.e., the time-variant LLR (Tv-LLR) and the time-invariant LLR (Ti-LLR). First, Tv-LLR is well suited for developing new type of the fault-current limiter (FCL) since it has no heat energy dissipated from its superconducting element during current-limiting process. Second, it may be used to produce the high voltage circuit breaker with current limiting ability. While Ti-LLR may be used to manufacture a new type of the superconducting transformer, with compact volume, lightweight and with continuously regulated turn-ratio (so it familiarized as time-variable transformer, TVT).

  15. 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

  16. 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.

  17. 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.

  18. 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.

  19. 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...

  20. 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)

  1. Recursion-transform method for computing resistance of the complex resistor network with three arbitrary boundaries

    Science.gov (United States)

    Tan, Zhi-Zhong

    2015-05-01

    We develop a general recursion-transform (R-T) method for a two-dimensional resistor network with a zero resistor boundary. As applications of the R-T method, we consider a significant example to illuminate the usefulness for calculating resistance of a rectangular m ×n resistor network with a null resistor and three arbitrary boundaries, a problem never solved before, since Green's function techniques and Laplacian matrix approaches are invalid in this case. Looking for the exact calculation of the resistance of a binary resistor network is important but difficult in the case of an arbitrary boundary since the boundary is like a wall or trap which affects the behavior of finite network. In this paper we obtain several general formulas of resistance between any two nodes in a nonregular m ×n resistor network in both finite and infinite cases. In particular, 12 special cases are given by reducing one of the general formulas to understand its applications and meanings, and an integral identity is found when we compare the equivalent resistance of two different structures of the same problem in a resistor network.

  2. 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 k?, 10 k?, 20 k?, 40 k?, 100 k?, and 150 k? 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.

  3. 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)

  4. 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…

  5. 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.

  6. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Divani, Nazila, E-mail: n-divani@birjand.ac.ir; Firoozabadi, Mohammad M. [Dep. Of Physics, Faculty of Science, University of Birjand, Birjand (Iran, Islamic Republic of); Bayat, Esmail [Nuclear Science and Technology Research Institute, Atomic Energy Organization of Iran (Iran, Islamic Republic of)

    2014-11-24

    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.

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

    Science.gov (United States)

    Divani, Nazila; Bayat, Esmail; Firoozabadi, Mohammad M.

    2014-11-01

    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.

  9. Modeling of N-well device and N-well field resistors

    Science.gov (United States)

    Kumar Singh, Rahul; Roy, J. N.

    2006-11-01

    Modeling of both N-well device and N-well field is reported here. A simple model as well as an advanced model have been used to model both types of resistors. The modeling has been carried out using MATLAB 6.5 and equations derived from device physics. Detailed modeling of an N-well field resistor, which is not generally available in the literature, has been carried out in great details. The results of various models applicable to different types of N-well resistors have been compared with operating conditions kept the same. A simulation strategy for circuit design has also been suggested.

  10. 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.

  11. 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

  12. 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 node’s 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.

  13. 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.)

  14. 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

  15. 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...

  16. 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...

  17. 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.

  18. Noise properties of Pb/Cd-free thick film resistors

    International Nuclear Information System (INIS)

    Low-frequency noise spectroscopy has been used to examine noise properties of Pb/Cd-free RuO2- and CaRuO3-based thick films screen printed on alumina substrates. Experiments were performed in the temperature range 77-300 K and the frequency range 0.5-5000 Hz with multiterminal devices. The measured noise has been recognized as resistance noise that consists of background 1/f noise and components generated by several thermally activated noise sources (TANSs) of different activation energies. The total noise has been composed of the contributions generated in the resistive layer and in the resistive/conductive layers interface. These noise sources are non-uniformly distributed in the resistor volume. Noise intensity of new-resistive layers has been described by the noise parameter Cbulk. Pb/Cd-free layers turned out to be noisier than their Pb-containing counterparts; however, the removal of Pb and Cd from resistive composition is hardly responsible for the increase in the noise. In the case of RuO2 layers noise increases most likely due to larger grain size of RuO2 powder used to prepare resistive pastes. Information on the quality of the resistive-to-conductive layers interface occurred to be stored in the values of noise parameter Cint. Pb/Cd-free RuO2-based resistive pastes form well-behaved interfaces with various Ag-based conductive pastes. In contrast, CaRuO3-based paste forms bad contacts with AgPd terminations because the density of TANSs increases in the interface area.

  19. 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.

  20. 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…

  1. 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…

  2. 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.

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

    DEFF Research Database (Denmark)

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

    1999-01-01

    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. 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

  5. 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 ...

  6. Information Societies and Digital Divides

    OpenAIRE

    Sorj, Bernardo (Coord.)

    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 tech...

  7. 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...

  8. 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

  9. 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 100? 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 56?, 68?, 82?, 100?, and 220? have been measured. It is found that the 56?, 68? and 82 ? 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)

  10. 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)

  11. 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.

  12. 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.

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

    Directory of Open Access Journals (Sweden)

    Huan-Yi Cheng

    2015-10-01

    Full Text Available 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-film resistors with different thicknesses of 30.8 nm~334.7 nm were obtained by controlling deposition time. After deposition, the thin-film resistors were annealed at 400 °C under different durations in N2 atmosphere using the rapid thermal annealing (RTA process. The sheet resistance of NiCrSi thin-film resistors was measured using the four-point-probe method from 25 °C to 125 °C, then the temperature coefficient of resistance could be obtained. We aim to show that resistivity of NiCrSi thin-film resistors decreased with increasing deposition time (thickness and the annealing process had apparent effect on the sheet resistance and temperature coefficient of resistance. We also aim to show that the annealed NiCrSi thin-film resistors had a low temperature coefficient of resistance (TCR between 0 ppm/°C and +50 ppm/°C.

  14. 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, Wólczy?ska 133, 01-919 Warsaw (Poland); Institute of Microelectronics and Optoelectronics, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw (Poland); Makarovi?, Kostja [Jožef Stefan Institute, Jamova Cesta 39, SI-1000 Ljubljana (Slovenia); CoE NAMASTE, Jamova Cesta 39, SI-1000 Ljubljana (Slovenia); Belavi?, Darko [HIPOT-RR d.o.o., Šentpeter 18, SI-8222 Oto?ec (Slovenia); CoE NAMASTE, Jamova Cesta 39, SI-1000 Ljubljana (Slovenia); Jakubowska, Malgorzata [Institute of Electronic Materials Technology, Wólczy?ska 133, 01-919 Warsaw (Poland); Faculty of Mechatronics, Warsaw University of Technology, ?w. 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.

  15. 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.

  16. 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)

  17. 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

  18. Ni-Cr thin film resistor fabrication for GaAs monolithic microwave integrated circuits

    International Nuclear Information System (INIS)

    Different Ni-Cr alloys were sputter-deposited on silicon nitride-coated GaAs substrates and covered with a spin-coated polyimide layer to develop thin film metal resistors for GaAs monolithic microwave integrated circuits (MMICs). The contact to the resistors was made through vias in the polyimide layer by sputter-deposited Ti/Au interconnect metal. The variation of contact resistance, sheet resistance (R S) and temperature coefficient of resistance (TCR) of the Ni-Cr resistors with fabrication process parameters such as polyimide curing thermal cycles and surface treatment given to the wafer prior to interconnect metal deposition has been studied. The Ni-Cr thin film resistors exhibited lower R S and higher TCR compared to the as-deposited Ni-Cr film that was not subjected to thermal cycles involved in the MMIC fabrication process. The change in resistivity and TCR values of Ni-Cr films during the MMIC fabrication process was found to be dependent on the Ni-Cr alloy composition

  19. 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

  20. 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 350°C, 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.

  1. 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

  2. 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...

  3. 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…

  4. 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.

  5. 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

  6. 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.

  7. 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...

  8. Annealing effect on the electrical properties and composition of a NiCrAl thin film resistor

    Science.gov (United States)

    Chuang, Nai-Chuan; Lin, Jyi-Tsong; Chen, Huey-Ru

    2015-12-01

    The composition of NiCrAl thin film resistors, under different annealing conditions in a N2 atmosphere, was investigated. The Auger electron spectrum (AES) has been used in studying the composition of NiCrAl thin films. The concentration ratio of Cr to Ni decreases when the annealing temperature increases. The electrical properties of a NiCrAl thin film resistor are affected by the concentrations of Cr and Ni, which lead to a higher temperature coefficient of resistance (TCR) and a lower sheet resistivity. The TCR of a NiCrAl thin film resistor is ?5 ppm/°C at a 250 °C annealing temperature.

  9. 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....

  10. 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)

  11. 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…

  12. 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…

  13. 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…

  14. 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)

  15. 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)

  16. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  18. Non-Gaussian Fluctuations in Biased Resistor Networks: Size Effects versus Universal Behavior

    CERN Document Server

    Pennetta, C; Reggiani, L; Ruffo, S

    2005-01-01

    We study the distribution of the resistance fluctuations of biased resistor networks in nonequilibrium steady states. The stationary conditions arise from the competition between two stochastic and biased processes of breaking and recovery of the elementary resistors. The fluctuations of the network resistance are calculated by Monte Carlo simulations which are performed for different values of the applied current, for networks of different size and shape and by considering different levels of intrinsic disorder. The distribution of the resistance fluctuations generally exhibits relevant deviations from Gaussianity, in particular when the current approaches the threshold of electrical breakdown. For two-dimensional systems we have shown that this non-Gaussianity is in general related to finite size effects, thus it vanishes in the thermodynamic limit, with the remarkable exception of highly disordered networks. For these systems, close to the critical point of the conductor-insulator transition, non-Gaussiani...

  19. 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)

  20. 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

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

    Science.gov (United States)

    Tan, Zhi-Zhong

    2015-02-01

    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.

  2. 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.

  3. Control of a fractional chaotic system based on a fractional-order resistor—capacitor filter

    International Nuclear Information System (INIS)

    We present a new fractional-order resistor—capacitor 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

  4. Transport nonuniversality and critical behavior of the piezoresistive response in thick-film resistors

    OpenAIRE

    Vionnet-Menot, Sonia; Grimaldi, Claudio; Maeder, Thomas; Ryser, Peter; Strässler, Sigfrid

    2003-01-01

    Thick-film resistors (TFRs) consist of a percolating network of conducting oxide nanoparticlesdispersed in an insulating glassy matrix, whose resistive properties are dominated by quantumtunneling across insulating layers separating adjacent conducting grains. Tunneling processes are at the origin of the high sensitivity of the TFRs resistances to applied strains. We have measuredtransport and piezoresistive response for different RuO2-based TFRs as a function of metallic concentration x and...

  5. Electrochemical, morphological and microstructural characterization of carbon film resistor electrodes for application in electrochemical sensors

    OpenAIRE

    Gouveia-Caridade, Carla; Soares, David M.; Liess, Hans-Dieter; Christopher M. A. Brett

    2008-01-01

    The electrochemical and microstructural properties of carbon film electrodes made from carbon film electrical resistors of 1.5, 15, 140 [Omega] and 2.0 k[Omega] nominal resistance have been investigated before and after electrochemical pre-treatment at +0.9 V vs SCE, in order to assess the potential use of these carbon film electrodes as electrochemical sensors and as substrates for sensors and biosensors. The results obtained are compared with those at electrodes made from previously investi...

  6. Development of resistor-type dummy load for high-voltage test operation

    International Nuclear Information System (INIS)

    We developed the resistor-type dummy load as a substitute for the klystron used in the factory test of the modulator. The dummy load can be used with 350 kV applied voltage, and 460 W input power in insulation oil. Compared to the klystron, the output waveforms are nearly same. Therefore, the dummy load has been used for the evaluation of the electrical characteristic of the modulator. The resistance value depends on the applied voltage, and varies secularly. (author)

  7. 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.

  8. 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.

  9. 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

  10. Unipolar sequential circuits based on individual-carbon-nanotube transistors and thin-film carbon resistors.

    Science.gov (United States)

    Ryu, Hyeyeon; Kälblein, Daniel; Schmidt, Oliver G; Klauk, Hagen

    2011-09-27

    A fabrication process for the monolithic integration of field-effect transistors based on individual carbon nanotubes and load resistors based on vacuum-evaporated carbon films into fast unipolar logic circuits on glass substrates is reported for the first time. The individual-carbon-nanotube transistors operate with relatively small gate-source and drain-source voltages of 1 V and combine large transconductance (up to 6 ?S), large ON/OFF ratio (>10(4)), and short switching delay time constants (12 ns). The thin-film carbon load resistors provide linear current-voltage characteristics and resistances between 300 k? and 100 M?, depending on the layout of the resistors and the thickness of the vacuum-evaporated carbon films. Various combinational circuits (NAND, NOR, AND, OR gates) as well as a sequential circuit ( ?S ?R NAND latch) have been fabricated and characterized. Although these unipolar circuits cannot compete with optimized complementary circuits in terms of integration density and static power consumption, they offer the possibility of realizing air-stable, low-voltage integrated circuits with promising static and dynamic performance on unconventional substrates for large-area electronics applications, such as displays or sensors. PMID:21870841

  11. 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.

  12. 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

  13. 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...

  14. 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...

  15. 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...

  16. 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)

  17. 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…

  18. 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,…

  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. 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.

  1. Compact chromium oxide thin film resistors for use in nanoscale quantum circuits

    OpenAIRE

    Nash, C. R.; Fenton, J. C.; Constantino, N. G. N.; Warburton, P. A

    2014-01-01

    We report on the electrical characterisation of a series of thin chromium oxide films, grown by dc sputtering, to evaluate their suitability for use as on-chip resistors in nanoelectronics. By increasing the level of oxygen doping, the room-temperature sheet resistance of the chromium oxide films was varied from 28$\\Omega / \\square$ to 32.6k$\\Omega / \\square$. The variation in resistance with cooling to 4.2K in liquid helium was investigated; the sheet resistance at 4.2K var...

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

    Science.gov (United States)

    Vadai, Gergely; Mingesz, Robert; Gingl, Zoltan

    2015-09-01

    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—in order 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.

  3. High-Voltage Sensitivity Studies of Model Thick-Film Resistors

    OpenAIRE

    Johner, Niklaus; Maeder, Thomas; Grimaldi, Claudio; Kambli, Adrian; Saglini, Igor; Jacq, Caroline; Ryser, Peter

    2006-01-01

    In this work we seek to better understand the mechanisms governing pulse voltage trimming in disordered conductor-insulator composites. Therefore, we investigate the effect of the composition of thick-film resistors (TFRs) on sensitivity to high voltage pulses. We investigate four series of RuO2-based TFRs: two different glass compositions and two different RuO2 grain sizes. For each combination of glass and grain size, different RuO2 concentrations are studied. It is thought that the g...

  4. 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

  5. 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

  6. 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.

  7. 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...

  8. 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...

  9. Experimental verification of temperature coefficients of resistance for uniformly doped P-type resistors in SOI

    International Nuclear Information System (INIS)

    Many today's microsystems like strain-gauge-based piezoresistive pressure sensors contain doped resistors. If one wants to predict correctly the temperature impact on the performance of such devices, the accurate data about the temperature coefficients of resistance (TCR) are essential. Although such data may be calculated using one of the existing mobility models, our experiments showed that we can observe the huge mismatch between the calculated and measured values. Thus, in order to investigate the TCR values, a set of the test structures that contained doped P-type resistors was fabricated. As the TCR value also depends on the doping profile shape, we decided to use the very thin, 340 nm thick SOI wafers in order to fabricate the quasi-uniformly doped silicon layers ranging from 2 × 1017 at cm?3 to 1.6 × 1019 at cm?3. The results showed that the experimental data for the first-order TCR are quite far from the calculated ones especially over the doping range of 1018–1019 at cm?3 and quite close to the experimental ones obtained by Bullis about 50 years ago for bulk silicon. Moreover, for the first time, second-order coefficients that were not very consistent with the calculations were obtained.

  10. Compact chromium oxide thin film resistors for use in nanoscale quantum circuits

    Science.gov (United States)

    Nash, C. R.; Fenton, J. C.; Constantino, N. G. N.; Warburton, P. A.

    2014-12-01

    We report on the electrical characterisation of a series of thin amorphous chromium oxide (CrOx) films, grown by dc sputtering, to evaluate their suitability for use as on-chip resistors in nanoelectronics. By increasing the level of oxygen doping, the room-temperature sheet resistance of the CrOx films was varied from 28 ?/? to 32.6 k ?/? . The variation in resistance with cooling to 4.2 K in liquid helium was investigated; the sheet resistance at 4.2 K varied with composition from 65 ?/? to above 20 G ?/? . All of the films measured displayed linear current-voltage characteristics at all measured temperatures. For on-chip devices for quantum phase-slip measurements using niobium-silicon nanowires, interfaces between niobium-silicon and chromium oxide are required. We also characterised the contact resistance for one CrOx composition at an interface with niobium-silicon. We found that a gold intermediate layer is favourable: the specific contact resistivity of chromium-oxide-to-gold interfaces was 0.14 m?cm2, much lower than the value for direct CrOx to niobium-silicon contact. We conclude that these chromium oxide films are suitable for use in nanoscale circuits as high-value resistors, with resistivity tunable by oxygen content.

  11. Compact chromium oxide thin film resistors for use in nanoscale quantum circuits

    Energy Technology Data Exchange (ETDEWEB)

    Nash, C. R.; Fenton, J. C.; Constantino, N. G. N.; Warburton, P. A. [London Centre for Nanotechnology, UCL, 17–19 Gordon Street, London WC1H 0AH (United Kingdom)

    2014-12-14

    We report on the electrical characterisation of a series of thin amorphous chromium oxide (CrO{sub x}) films, grown by dc sputtering, to evaluate their suitability for use as on-chip resistors in nanoelectronics. By increasing the level of oxygen doping, the room-temperature sheet resistance of the CrO{sub x} films was varied from 28 ?/? to 32.6?k?/?. The variation in resistance with cooling to 4.2?K in liquid helium was investigated; the sheet resistance at 4.2?K varied with composition from 65 ?/? to above 20?G?/?. All of the films measured displayed linear current–voltage characteristics at all measured temperatures. For on-chip devices for quantum phase-slip measurements using niobium–silicon nanowires, interfaces between niobium–silicon and chromium oxide are required. We also characterised the contact resistance for one CrO{sub x} composition at an interface with niobium–silicon. We found that a gold intermediate layer is favourable: the specific contact resistivity of chromium-oxide-to-gold interfaces was 0.14 m?cm{sup 2}, much lower than the value for direct CrO{sub x} to niobium–silicon contact. We conclude that these chromium oxide films are suitable for use in nanoscale circuits as high-value resistors, with resistivity tunable by oxygen content.

  12. New metal resistor bolometer for measuring vacuum ultraviolet and soft x radiation

    International Nuclear Information System (INIS)

    A new metal resistor bolometer has been developed by applying thin-film technology. It is composed of three layers, a 4-?m-thick radiation absorber made of gold, a 7.5-?m-thick kapton dielectric, and a 0.1-?m-thick 5-k? gold resistor. This detector with the appropriate electronics shows a linear response to radiation power, including both neutral-particle emission and electromagnetic radiation from the soft x-ray part of the spectrum to the infrared. The bolometer has a very high operating reliability and sufficient suppression of ambient interference under extreme environmental conditions, such as high neutron and gamma radiation fluxes, high temperatures, mechanical vibrations, and strong electromagnetic fields. In plasma discharges in the ASDEX tokamak a radiation detection limit of 100 ?W/cm2 was obtained at a time resolution of 10 ms. The bolometers of an array can be calibrated in situ; the calibration data are reproducible and stable in time within +- 10%. Measurements in ASDEX which demonstrate the capability of the method are discussed

  13. 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

  14. 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.

  15. 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...

  16. 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.

  17. 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.

  18. 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.

  19. 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...

  20. Surface-modified RuO2-based thick film resistors using Nd:YAG laser

    Science.gov (United States)

    Gofuku, E.; Ogama, T.; Takasago, H.

    1989-12-01

    An RuO2-based thick film resistor (TFR) is a cermet-type resistor which consists of RuO2 particles and glass. Paste containing organic vehicles is printed onto an insulating substrate, and subsequent firing at about 900 °C makes the cermet-type resistors. TFRs are widely utilized as electrical resistive materials in electric devices such as hybrid ICs (integrated circuits) [see, for example, R. W. Vest, Ceram. Bull. 65, 631 (1986)]. The features of an advanced laser application process to control the electrical resistivity of the TFRs were proposed. This new process is an application of surface-modification using laser beams. In this paper, a mechanism of the surface-modification of the TFR is considered using results of morphology observation, x-ray diffraction (XRD), and x-ray photoemission spectroscopy (XPS). The following points should be noticed. (1) In the surface-modifying process using normal mode pulse Nd:YAG laser beams, glass in the TFR is modified and supersaturated with ruthenium impurities because of rapid heating and rapid cooling rates in the irradiation process; the specific resistivity of the modified glass is extremely decreased, estimated at 10-3 ? cm at most. (2) No new crystalline phase in the ruthenium-oxygen system is detected after the surface modification by results of x-ray diffraction (XRD) analysis. (3) The valence state of the ruthenium ions in the modified glass is more positively charged than that in crystalline RuO2 , while the valence states of lead and oxygen ions in the modified glass are more negatively charged than in as-fired glass before surface modification according to the results obtained by x-ray photoemission spectroscopy (XPS) analysis. It is suggested that if ruthenium ions introduce electrons into the modified glass and if these electrons behave as itinerant electron carriers in the modified glass, a decrease in the resistivity of TFR after the surface modification is quite reasonable for the results of XPS.

  1. Programmable diode/resistor-like behavior of nanostructured vanadium pentoxide xerogel thin film.

    Science.gov (United States)

    Wan, Zhenni; Darling, Robert B; Anantram, M P

    2015-11-11

    Electrical properties of a Cr/V2O5/Cr structure are investigated and switching of the device due to electrochemical reactions is observed at low bias (film are involved in the electrochemical reactions. It is proposed that an interfacial layer with reduced oxidation state forms at the Cr/V2O5 interface, and creates a higher Schottky barrier due to rise of electron affinity. Different interfacial layer thicknesses in forward and reverse first sweeps are responsible for different I-V characteristics in subsequent sweeps. The results suggest future applications of these V2O5 thin films in low-power read-only memory devices and diode-resistor networks. PMID:26529244

  2. 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 p–n and n–p 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)

  3. 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.

  4. 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.

  5. Developments in the use and design of a suspended resistor IR scene projector technology

    Science.gov (United States)

    Pritchard, Alan P.; Lake, Stephen P.; Sturland, Ian M.; Balmond, Mark D.; Gough, David W.; Venables, Mark A.

    1995-06-01

    This paper describes two aspects of work carried out at British Aerospace on a family of suspended resistor infrared scene generators intended as sources for exercising infrared seeker systems in simulation environments. In the first aspect, a 256 X 256 system has matured and entered service with hardware-in-the-loop (HWIL) simulation facilities. This system, designated TPS4 (for thermal picture synthesizer) has performance suitable for air target tracking studies, and certain aspects of its characteristics in use are described. In the second aspect, research work has been carried out on the extension of the system performance to enable the representation of higher temperature targets, such as are required for countermeasures work. These improved devices are designated TPS5, and aspects of their rationale, design, and evaluation are described. Prototype arrays suitable for eventual systems of complexity 512 X 512 and beyond have been tested.

  6. 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

  7. 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...

  8. Actividades de experimentación con materiales de bajo coste para la enseñanza de física: resistores y capacitores de grafito

    Directory of Open Access Journals (Sweden)

    Marcos Alfredo Salami

    2007-04-01

    Full Text Available This work presents an investigation carried out at the Pontifical Catholic University of Rio Grande do Sul from April 2002 to December 2003, involving the feasibility of using resistors and capacitors made of graphite laid upon paper, cardboard and plastic, in order to help the learning of electricity through experimentation. Its specific focus was the contents on resistibility, calculation of equivalent resistance of serial and parallel associations of resistors and capacitors, dependence of capacitance to the area, to the distance between the boards and the shape of the boards. The low cost technique resulting from this development allows students to playfully manipulate variables involved in the definition of electric resistance and capacitance, besides making it possible for them to crate and modify freely the associations of resistors andcapacitors, by just using a multimeter with a capacimeter function, paper and a 6B type pencil. It also has a great potential to stimulate the comprehension and learning process of such contents once it is pleasant, simple and low costly. It also promotes the engagement and free participation of all students. Graphite has already been used in the production of resistors to measure individual resistance and associations as described in the article by (Rocha Filho et al., 2004, and also in the production of capacitors to measure the capacitances in the activities mentioned in the master’s dissertation of (Salami, 2004.

  9. 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.

  10. 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

  11. 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.

  12. Bruce B Unit 6 divider plate sealing skin installation

    International Nuclear Information System (INIS)

    Bruce Unit 6 went into service in 1984, since its initial startup reactor inlet header temperatures have risen steadily. In 1999 reactor inlet header (RIH) temperatures had risen to the point that extraction steam to both high pressure feed water heaters had being valved out of service in an effort to keep boiler pressures above the units safe operating margin and RIH temperatures low. It was projected if no action was taken to reduce RIH temperature levels unit derating would start in 2000 and continue at a rate of 0.8% reactor power per year (-5.7Megawatts). Experience gained from the Bruce A units and other CANDU stations with segmented divider plates pointed to two main contributors to RIH temperature increases, divider plate leakage and boiler tube ID fouling. Divider plate leakage is a measurable condition, with proven results if corrected. Boiler tube ID fouling on the other hand was a measurable condition via eddy current and oxi-probe inspections, however only limited data existed at that time as to its effect on RIHT. In addition the effectiveness of ID cleaning was unknown and the equipment and process needed conversion and qualification for Bruce units. The decision was made to reduce the divider plate leakage now, and later perform an ID clean if the process proves beneficial. For reasons of cost, time (design and installation), dose and remaining boiler life, Bruce B design engineering decided that sealing the divider plates best suited the stations needs. During the last few years of Bruce A's operation a design was developed that would seal the existing divider plates rather than replacement. The sealing design consisted of a thin stainless steel sealing skin that covered the entire segmented divider plate plus all peripheral seams. Thicker stainless steel clamping plates covered the sealing skin panels to hold them in place and provide erosion protection. The sealing skin and clamping plates were held in place by utilizing the bolt patterns of the original divider plate design. No welding was required. The installation process proceeded as planned, actual installation time was approx. 20 days including opening, decontamination, installation and closing of all 8 boilers. The cost was approx. $2M. Dose received during the installation was 20 man Rem. On return to full power station thermal performance staff reported a 3 to 4 deg C reduction in RIHT levels. Boiler pressures had risen from 4120kpa before the outage to 4400 kpa. Gross power production had increased by 20 Megawatts. (author)

  13. 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 Botswana’s 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.

  14. Analyzing Broadband Divide in the Farming Sector

    DEFF Research Database (Denmark)

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

    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...

  15. 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.

  16. 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…

  17. 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,…

  18. 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…

  19. 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,…

  20. 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…

  1. 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)

  2. 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.

  3. Analyzing Broadband Divide in the Farming Sector

    DEFF Research Database (Denmark)

    Jensen, Michael; Gutierrez Lopez, Jose Manuel

    2013-01-01

    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 could be one of the points to focus in a near future broadband access plans.

  4. 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.

  5. 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.)

  6. 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.)

  7. Bridging the Divide between Science and Journalism

    OpenAIRE

    Marincola Francesco M; Van Eperen Laura; Strohm Jennifer

    2010-01-01

    Abstract There are countless reasons nearly every scientist should learn how to communicate effectively with the media, including increased understanding of critical research findings to attract or sustain funding and build new professional partnerships that will further propel forward research. But where do scientists begin? Bridging the Divide between Science and Journalism offers practical tips for any scientist looking to work with the media. Given the traditional and internet-based sourc...

  8. Library outreach: addressing Utah's “Digital Divide”

    OpenAIRE

    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 Medicine—Midcontinental Region, the Utah Department of Health, and the Utah Area Health Ed...

  9. 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

  10. 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...

  11. 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...

  12. REGENERATIVE GAS TURBINES WITH DIVIDED EXPANSION

    DEFF Research Database (Denmark)

    Elmegaard, Brian; Qvale, Einar Bjørn

    2004-01-01

    Recuperated gas turbines are currently drawing an increased attention due to the recent commercialization of micro gas turbines with recuperation. This system may reach a high efficiency even for the small units of less than 100 kW. In order to improve the economics of the plants, ways to improve 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 efficienc...

  13. Inductive voltage divider calibration with sampling method

    Directory of Open Access Journals (Sweden)

    Corminboeuf David

    2014-01-01

    Full Text Available This paper presents an automatic system developed at METAS for the calibration of inductive voltage dividers (IVD. The used method is primary for the n/10 ratio. With the described improvements, the calibration of IVDs has been made easier, faster and more reproducible than with the manual system used before. The uncertainties which can be reached with this new system are 28·10-9 for the in phase and quadrature parts at a frequency of 1 kHz.

  14. 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.

  15. 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.

  16. 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 informatio...

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

    Directory of Open Access Journals (Sweden)

    Derya BAYRIMENGÄ°LLÄ°

    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.

  18. 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.

  19. 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.

  20. 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

  1. 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 mm×0.5 mm, 1 mm×1 mm as well as 20 ?m×1.8 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.

  2. 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 30–200 °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.

  3. 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.

  4. 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

  5. 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)

  6. 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 = 5K?/sq. with hot and cold TCR of 225 and 470 ppm/oC respectively, whereas the same composition gives 1,2 K?/sq. and 1.65 K?/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)

  7. 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.

  8. 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

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

    OpenAIRE

    Jendrysik, Christian

    2014-01-01

    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 ...

  10. 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

  11. 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

  12. 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

  13. 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

  14. 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 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

  15. The Bread Book Multiplying and Dividing

    CERN Document Server

    Hyland, Tony

    2008-01-01

    Bread is an important and useful food and can be bought from stores and small bakeries. Most loaves of bread are shaped like rectangular prisms. Flour, water, yeast, and salt are the key ingredients for making bread. A baker uses a recipe with different measurements of flour and water for each loaf. A baker's dozen is 13 loaves of bread, which is one more than a regular dozen.

  16. 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.

  17. Bridging the Divide between Science and Journalism

    Directory of Open Access Journals (Sweden)

    Marincola Francesco M

    2010-03-01

    Full Text Available Abstract There are countless reasons nearly every scientist should learn how to communicate effectively with the media, including increased understanding of critical research findings to attract or sustain funding and build new professional partnerships that will further propel forward research. But where do scientists begin? Bridging the Divide between Science and Journalism offers practical tips for any scientist looking to work with the media. Given the traditional and internet-based sources for medical research and healthcare-related news now available, it is imperative that scientists know how to communicate their latest findings through the appropriate channels. The credible media channels are managed by working journalists, so learning how to package vast, technical research in a form that is appetizing and "bite-sized" in order to get their attention, is an art. Reducing years of research into a headline can be extremely difficult and certainly doesn't come naturally to every scientist, so this article provides suggestions on how to work with the media to communicate your findings.

  18. 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.

  19. Procesamiento analógico a partir de elementos altamente resistivos / Analog Processing based on Quasi-Infinite Resistors

    Scientific Electronic Library Online (English)

    Carlos, Muñiz-Montero; Luis Abraham, Sánchez-Gaspariano; Víctor Hugo, Ponce-Ponce; María Elena, Aguilar-Jáuregui; Osvaldo, Espinosa-Sosa.

    2013-12-01

    Full Text Available El presente trabajo propone una técnica para diseñar, a partir de elementos altamente resistivos, circuitos integrados CMOS analógicos tales como amplificadores compensados en offset, filtros sintonizables de baja frecuencia, espejos de corriente programables y generadores de funciones de membresía. [...] La técnica propuesta incorpora transistores operando en la región de inversión débil para reducir los requerimientos de área y las contribuciones de offset, así como para reducir las componentes de ruido y distorsión, mejorando el compromiso exactitud-velocidad-potencia. Éstas características permiten facilitar el acondicionamiento de señales de baja frecuencia y habilitar el diseño de dispositivos con sintonización multidécada de ganancia y frecuencia. Por otro lado, los circuitos propuestos son atractivos para la implementación analógica de arquitecturas reservadas al ámbito digital, tales como filtros adaptables y sistemas difusos, por mencionar algunos, así como dispositivos de procesamiento y acondicionamiento de señal de alta eficiencia. Se reportan caracterizaciones a partir de simulaciones, mediciones y análisis estadísticos de prototipos diseñados con una tecnología CMOS de 0.5|im de largo de canal, dos capas de polisilicio y tres capas de metal. Los resultados obtenidos concuerdan con aquellos anticipados en el diseño de los circuitos. Abstract in english This work proposes a technique for design of CMOS analog integrated circuits such as offset compensated amplifiers, low-frequency filters, programmable current mirrors and membership function generators, based on high-value (quasi-infinite) resistors. The proposed technique incorporates transistors [...] operating in weak-inversion mode in order to reduce the area requirements and minimize the DC-offset. In addition, improvement on both, noise performance and linearity, are achieved along with an enhanced speed-accuracy-power tradeoff. Those features make easier the processing of low-frequency signals and allow the design of systems with multi-decade tunability of gain and frequency. The presented circuits are attractive for implementation of high-accuracy processors for signal conditioning as well as architectures usually reserved to digital approaches, for instance neural networks, adaptive filters, and neuro-fuzzy systems, to mention a few. Characterization through computer simulations, statistical analysis and experimental measurements of prototypes in a double-poly, three metal layers, 0.5pm CMOS technology are reported. The attained results follow the course anticipated in the design of the circuits.

  20. Robust Platinum Resistor Thermometer (PRT) Sensors and Reliable Bonding for Space Missions

    Science.gov (United States)

    Cucullu, Gordy C., III; Mikhaylov, Rebecca; Rajeshuni, Ramesham; Petkov, Mihail; Hills, David; Uribe, Jose; Okuno, James; De Los Santos, Greg

    2013-01-01

    Platinum resistance thermometers (PRTs) provide accurate temperature measurements over a wide temperature range and are used extensively on space missions due to their simplicity and linearity. A standard on spacecraft, PRTs are used to provide precision temperature control and vehicle health assessment. This paper reviews the extensive reliability testing of platinum resistor thermometer sensors (PRTs) and bonding methods used on the Mars Science Laboratory (MSL) mission and for the upcoming Soil Moisture Active Passive (SMAP) mission. During the Mars Exploration Rover (MER) mission, several key, JPL-packaged PRTs failed on those rovers prior to and within 1-Sol of landing due to thermally induced stresses. Similar failures can be traced back to other JPL missions dating back thirty years. As a result, MSL sought out a PRT more forgiving to the packaging configurations used at JPL, and extensively tested the Honeywell HRTS-5760-B-U-0-12 sensor to successfully demonstrate suitable robustness to thermal cycling. Specifically, this PRT was cycled 2,000 times, simulating three Martian winters and summers. The PRTs were bonded to six substrate materials (Aluminum 7050, treated Magnesium AZ231-B, Stainless Steel 304, Albemet, Titanium 6AL4V, and G-10), using four different aerospace adhesives--two epoxies and two silicones--that conformed to MSL's low out-gassing requirements. An additional epoxy was tested in a shorter environmental cycling test, when the need for a different temperature range adhesive was necessary for mobility and actuator hardware late in the fabrication process. All of this testing, along with electrostatic discharge (ESD) and destructive part analyses, demonstrate that this PRT is highly robust, and not subject to the failure of PRTs on previous missions. While there were two PRTs that failed during fabrication, to date there have been no in-flight PRT failures on MSL, including those on the Curiosity rover. Since MSL, the sensor has gone through a change in construction such that the manufacturer significantly restricts the minimum temperature. However, significant subsequent testing was performed with this new version of the part to show that it indeed is still robust to at least Mars minimum temperatures of -135(sup o)C. The additional completed testing will be described. This work has resulted in a successful sensor package qualification and a reliable bonding method suitable for use over large temperature extremes.

  1. 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 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.

  2. 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.

  3. 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.

  4. "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.

  5. Avaliação de modelo de extração da água do solo por sistemas radiculares divididos entre camadas de solo com propriedades hidráulicas 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 avaliação da capacidade de raízes de plantas em extrair água do solo é de grande importância na modelagem da taxa de transpiração e, para entender o crescimento e rendimento vegetal e o balanço de água e de solutos no solo. Para testar um modelo de extração radicular macroscópico baseado no processo em escala microscópica, descreveram-se os resultados de um experimento com plantas cujo sistema radicular foi dividido entre camadas de solo com propriedades hidráulicas contrastantes. Um experimento de lisímetro dividido com plantas de sorgo foi realizado em Piracicaba-SP. Quatro lisímetros com dois compartimentos separados fisicamente (split-pot foram construídos e preenchidos com material de dois tipos de solo de diferentes classes texturais (um solo de textura média - AR e outro de textura argilosa - AG. Durante um mês e meio foi imposto um regime hídrico, alternando a irrigação entre os compartimentos. O teor de água nos compartimentos dos lisímetros foi monitorado com TDR e tensiômetros. O material dos dois solos foi analisado conforme método-padrão quanto às suas propriedades de retenção e condução da água. 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 extração de água ocorreu preferencialmente do compartimento do lisímetro com maior potencial de fluxo matricial. Em certas ocasiões houve transferência de água do lado de maior para o de menor potencial de fluxo matricial, com a liberação da água ao solo pelo sistema radicular (hydraulic lift. Para compensar o efeito da heterogeneidade da distribuição radicular e da atividade radicular, incluiu-se, no modelo, um fator empírico f de correção. O modelo testado descreveu bem 80 % das observações com a utilização de valores de f de 0,01506 e 0,003713, para os solos AR e AG, respectivamente. O modelo simulou a liberação de água ao solo mais frequentemente do que ela ocorreu no experimento. Esse fato pode indicar que a resistência interna do sistema radicular, não contabilizada pelo modelo, pode ter papel importante nas relações hídricas 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

  6. 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.

  7. A Compound Generic Quantitative Framework for Measuring Digital Divide

    Directory of Open Access Journals (Sweden)

    Noureldien A. Noureldien

    2014-07-01

    Full Text Available 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 measuring digital divide. Researchers have proposed many metrics and indices to measure digital divide. However, most of the proposed measures are bivariate comparisons that reduce measurement to comparisons of Internet penetration rates or alike. This paper proposes a compound generic framework for quantitative measuring of digital divide on the individuals or group level. The proposed framework takes into account the context of the digital divide in each society.

  8. 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 1970’s. Some experts in areas like Public Policy, Communications, Business Management and Economics have also addressed the phenomenon of digital divide since the 1990’s. 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...

  9. 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...

  10. 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...

  11. 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...

  12. Can Water Store Charge?

    OpenAIRE

    Ovchinnikova, Kate; Pollack, Gerald H

    2009-01-01

    Previous work from this and other laboratories has demonstrated large pH gradients in water. Established by passing current between immersed electrodes, pH gradients between electrodes were found to disappear slowly, persisting for tens of minutes after the current had been turned off. We find here that these pH gradients reflect a genuine separation of charge: at times well after disconnection of the power supply, current could be drawn through a resistor placed between the charging electrod...

  13. The effect of pre-ionization by a shunt resistor on the reproducibility of plasma focus x-ray emission

    Science.gov (United States)

    Ahmad, S.; Sadiq, Mehboob; Shafiq, M.; Waheed, A.; Lee, P.; Zakaullah, M.

    2006-08-01

    The effect of pre-ionization by means of a shunt resistor on the x-ray emission of a low energy (1.8 kJ) plasma focus device powered by a 9 µF capacitor bank, charged at 20 kV and giving a peak discharge current of about 175 kA is investigated. Quantrad Si pin-diodes along with a suitable filter are employed as time-resolved x-ray detectors, whereas a multipinhole camera with absorption filters is used for time-integrated analysis. X-ray flux in 4?-geometry is measured as a function of argon filling pressure with and without pre-ionization. It is found that appropriate selection of the shunt resistor increases shot-to-shot reproducibility of the x-ray emission as well as the stability of the pinch filament and broadens the x-ray pulse width. The x-ray emission is also enhanced by (45 ± 5)% at the optimum pressure.

  14. IDENTIFIKASI NILAI HAMBAT JENIS ARANG KAYU, ARANG KULIT MANGGA, DAN ARANG KULIT PISANG: BAHAN ALTERNATIF PENGGANTI RESISTOR FILM KARBON

    Directory of Open Access Journals (Sweden)

    Intan Kusumawati

    2014-05-01

    Full Text Available Penelitian ini bertujuan untuk mengetahui nilai hambat jenis pada arang kayu, arang kulit mangga, dan arang kulit pisang sebagai bahan alternatif pengganti resistor film karbon. Pada penelitian ini dilakukan penumbukkan arang kayu, arang kulit mangga, dan kulit pisang sehingga dihasilkan bubuk arang yang halus melalui proses penyaringan. Setelah itu dilakukan pemampatan arang kayu dalam pipet/sedotan plastik dengan luas permukaan (A = 4,08 x 10-4 cm. Kemudian hambatan diukur menggunakan multimeter dan dilakukan perhitungan hambat jenis arang tersebut. Hasil penelitian menunjukkan bahwa arang kayu (0,73 x 106 m memiliki nilai hambat yang tinggi sehingga hambat jenisnya juga lebih tinggi dibandingkan dengan arang kulit mangga (0,28 x 106  m dan arang kulit pisang (0,24 x 106 m. Hal ini dikarenakan terjadi proses karbonisasi sempurna dalam pembuatan arang kayu. Oleh karena nilai hambatan yang dapat terbaca pada multimeter hanya menggunakan batas skala yang besar (Mega Ohm, maka arang kulit kayu, arang kulit mangga, dan arang kulit pisang hanya dapat dijadikan sebagai bahan alternatif pengganti resistor film karbon dengan ukuran nilai hambatan besar.

  15. 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.

  16. 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

  17. 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.

  18. 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

  19. 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

  20. Effects of resistors and capacitors inserted between wires and chip bonding pads on current-voltage characteristics of series junction arrays

    International Nuclear Information System (INIS)

    Series Nb/AlO x/Nb junction array circuits are commonly used for evaluation of a critical current (I c) spread as an important parameter on Nb-based LSI chips. We present a junction array circuit suitable for accurate evaluation of the spread. The circuit has a tolerance for the I c suppression caused by external noises and synchronous switching which are often observed in measurements. Key elements of the circuit are the low value resistors, large value capacitors, and high value resistors inserted between wires and chip bonding pads. This paper describes effects of these key elements on current-voltage characteristics of junction arrays

  1. 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)

  2. 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...

  3. 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)

  4. 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 ...

  5. 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 ...

  6. Dividir para reinar / Diviser pour régner / Divide and conquer / Divide y vencerás

    Scientific Electronic Library Online (English)

    Teresa Vaz, Martins; Raúl, Toral.

    2012-06-01

    Full Text Available O objectivo deste artigo é apresentar brevemente a Sociofísica, uma disciplina que, nas últimas décadas, se tem vindo a desenvolver na fronteira entre a Física e as ciências sociais. Como ilustração da sua abordagem, iremos rever alguns modelos de formação de opinião, incidindo nas condições em que [...] uma sociedade é mais sensível à penetração de uma mensagem externa. Nomeadamente, iremos ver que é mais fácil uma mensagem ser consensualmente aceite numa sociedade caracterizada por conflitos - o que recorda a antiga máxima “dividir para reinar”. Concluiremos, sugerindo que a construção deste novo campo do saber requer uma colaboração entre sociólogos e físicos, que vá mais além de uma simples justaposição de conhecimentos. Abstract in spanish El objectivo de este trabajo es presentar brevemente la Sociofísica, una disciplina que en las últimas décadas se ha venido a desarrollar en la frontera entre la física y las ciencias sociales. Cómo ejemplo de su enfoque, se revisan algunos modelos de formación de opinión, centrándose en las condici [...] ones en que una sociedad es más sensible a la penetración de un mensaje externo. En particular, vemos que el mensaje es más fácilmente aceptado en una sociedad caracterizada por el conflicto, lo que nos acuerda el antiguo dicho latino, “divide y vencerás”. Concluimos sugiriendo que la construcción de este nuevo campo del conocimiento requiere una colaboración entre los sociólogos y físicos, que va más allá de una simple yuxtaposición de conocimientos. Abstract in english The aim of this paper is to briefly present Sociophysics, a discipline that in recent decades has been emerging on the borders between Physics and the Social Sciences. As an illustration of its approach, we will review some opinion formation models, focusing on the conditions under which a society i [...] s more sensitive to the penetration of an external message. In particular, we will see that it is easier for a message to be commonly accepted in a society characterized by conflicts - which recalls the old maxim “divide and conquer”. We conclude by suggesting that the construction of this new field of knowledge requires a union between sociologists and physicists that goes beyond a simple juxtaposition of knowledge.

  7. 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

  8. 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.)

  9. 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

  10. 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

  11. 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…

  12. 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…

  13. 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…

  14. 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…

  15. 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…

  16. 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…

  17. 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…

  18. 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.

  19. 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, ...

  20. 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.

  1. 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.

  2. 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 ?m2. The power consumption of the divider is 0.6 mW under 1.2 V supply voltage when operating at 988 MHz. (semiconductor integrated circuits)

  3. 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 ?m2. The power consumption of the divider is 0.6 mW under 1.2 V supply voltage when operating at 988 MHz.

  4. Digital Divide amongst Urban Youths in Malaysia – Myth or Reality?

    Directory of Open Access Journals (Sweden)

    Patrick C-H Soh

    2012-12-01

    Full Text Available 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 are further concerns that the digital divide is further widening because of the quantity and quality of access. Multivariate analysis reveals that Chinese youths are online for twice the duration of Malays and Indians. However, higher Internet usage may be a two-edged sword as higher Internet use are intertwined with higher risks and negative activities such as violent games, pornography, and gambling. The article also discusses various means to mitigate the risks of Internet usage.

  5. 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...

  6. 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.

  7. 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)

  8. 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,...

  9. Digital Divide between Teachers and Students in Urban Bangladesh

    OpenAIRE

    Khalid, Md. Saifuddin

    2012-01-01

    Telecom boom since 2000 and ‘Digital Bangladesh’ campaign since late 2008 created significant nationwide hype, resulting rapid increase in the use of digital devices. While studies are being conducted to use the ability of “power users of technology” for reducing digital divide, there is hardly any 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 cap...

  10. 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...

  11. 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...

  12. 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...

  13. 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...

  14. 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...

  15. Generation of five phase-locked harmonics by implementing a divide-by-three optical frequency divider

    CERN Document Server

    Suhaimi, Nurul Sheeda; Gavara, Trivikramarao; Nakagawa, Ken'ichi; Hong, Feng Lei; Katsuragawa, Masayuki

    2015-01-01

    We report the generation of five phase-locked harmonics, f_1: 2403 nm, f_2: 1201 nm, f_3: 801 nm, f_4: 600 nm, and f_5: 480 nm with an exact frequency ratio of 1 : 2 : 3 : 4 : 5 by implementing a divide-by-three optical-frequency divider in the high harmonic generation process. All five harmonics are generated coaxially with high phase coherence in time and space, which are applicable for various practical uses.

  16. The bounds of the set of equivalent resistances of n equal resistors combined in series and in parallel

    CERN Document Server

    Khan, Sameen Ahmed

    2010-01-01

    The order of the set of equivalent resistances, A(n) of n equal resistors combined in series and in parallel has been traditionally addressed computationally, for n up to 22. For larger n there have been constraints of computer memory. Here, we present an analytical approach using the Farey sequence with Fibonacci numbers as its argument. The approximate formula, A(n) ~ 2.55^n, obtained from the computational data up to n = 22 is consistent with the strict upper bound, A(n) ~ 2.618^n, presented here. It is further shown that the Farey sequence approach, developed for the A(n) is applicable to configurations other than the series and/or parallel, namely the bridge circuits and non-planar circuits. Expressions describing set theoretic relations among the sets A(n) are presented in detail. For completeness, programs to generate the various integer sequences occurring in this study, using the symbolic computer language MATHEMATCA, are also presented.

  17. 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

  18. Behavior of 1?? resistors at frequencies below 1?Hz and the problem of assigning a dc value

    Science.gov (United States)

    Fletcher, Nick; Götz, Martin; Rolland, Benjamin; Pesel, Eckart

    2015-08-01

    This paper presents a systematic study of the effects of reversals of current polarity on 1?? standard resistors. A selection of 1?? standards were measured on a dc cryogenic current comparator bridge and also on an ac current comparator bridge operating at 1?Hz. We find that the apparent 4 terminal resistance depends strongly on the dc reversal rate, in one case showing a variation of more than 0.1???/? for cycle times between 10?s and 1000?s. Even in the best cases, effects of at least 0.01???/? are present. Furthermore, the assumption that the apparent resistance value converges to a limiting value for long waiting times after reversal is not always upheld, making it difficult to quote a simple dc value. Existing models of Peltier heating at wire junctions do not completely explain our observations. The problems presented have been the limiting factor for 1?? measurements as part of a recent on-site comparison of quantum Hall effect resistance standards.

  19. 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.

  20. 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 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.

  1. [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

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

    Directory of Open Access Journals (Sweden)

    Sorin Dan ?ANDOR

    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.

  3. Conduction mechanisms and 1/f noise in thick-film resistors with Pb3Rh7O15 and Pb2Ru2O7

    International Nuclear Information System (INIS)

    Thick-film resistors with Pb3Rh7015 and Pb2Ru207 as conductors are considered. These compounds are chemically stable during the firing process of the resistors. The variation of sheet resistivity R/sub D'Alembertian/ with volume fraction conductor follows a simple power law. This result cannot be explained by percolation theory in its simple form. The conductivity is found to be independent of frequency up to 10 GHz. In both cases a small positive Hall coefficient is observed which is interpreted as being due to mixed electron and hole conduction. Finally the 1/f noise is considered, and is found to vary approximately linearly with R/sub D'Alembertian/. A theoretical model for the 1/f noise in thick-film resistors is presented that accounts for this linear relationship. The observed deviations from linearity indicate that probably tunneling through barriers at the interfaces between the conducting grains is an important factor in determining the conduction

  4. 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

  5. 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

  6. 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.

  7. 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.

  8. 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…

  9. 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…

  10. 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…

  11. 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…

  12. 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…

  13. 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…

  14. 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…

  15. 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…

  16. 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…

  17. 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

  18. 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 9.2–10.4% 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.

  19. 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.

  20. Climate Change and North-South Divide. Between and Within

    International Nuclear Information System (INIS)

    The traditional North-South divide has persisted through out the negotiations on climate change. Divergent state interests made striking a right balance between development and environmental protection an elusive endeavor as negotiators were striving to adopt a global climate regime. Four principles of international environmental law are of particular concern: the principle of common but differentiated responsibilities, the principle of equity, the precautionary principle, and the principle of sustainable development. With economic development being the overriding priority in developing countries, the negotiations leading to the Kyoto Protocol tend to prove that principles could be interpreted in different ways to fit particular interests. This study explains the confrontations between the North and the South and argues that climate change has by far strengthened the North-South divide both between and within. Accordingly, it concludes that there is a need to devise new principles

  1. 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 Darwin’s work and the overall implications of Darwin’s achievements for the homology/adaptation, often called the ‘form/function,’ divide.

  2. 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.

  3. 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.

  4. 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.

  5. Divided screen : the doppelgänger in German silent film

    OpenAIRE

    Rashidi, Bahareh

    2007-01-01

    The proliferation of the doppelgänger theme in so many films of Wilhemine and Weimar Germany raises the question of its historical significance, in particular during Germany’s “crisis of classical modernity”. While previous studies have addressed the double from a narrative perspective, focusing on its psychological significations as divided self, this thesis instead considers the theme from a structural and historical perspective: how, as a technical reproduction of the human ...

  6. The 'Digital Divide' Among Financially Disadvantaged Families in Australia

    OpenAIRE

    McLaren, Jennifer; Zappala, Gianni

    2002-01-01

    Despite figures suggesting that Australia is a high consumer of information and communication technologies (ICT), it is well documented that the pattern of this consumption is not spread evenly across the population; a 'digital divide' exists. In general, research suggests that people from higher socioeconomic backgrounds have greater access to ICT compared to those from lower socioeconomic backgrounds. A less well-researched area is the factors that may influence ICT access and usage within ...

  7. 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 ...

  8. Job quality in Europe: the North-South divide

    OpenAIRE

    Cerdeira, Maria da Conceição; Kovács, Ilona

    2008-01-01

    This paper examines the job quality in Europe. It is based on the results of the Fourth European Foundation Survey on working conditions covering different dimensions including work organisation, job content, autonomy at work, aspects of worker dignity, working time and work-life balance, working conditions and safety in the workplace. The results point to the existence of great diversity in the job quality across Europe and the north-south divide. The job quality differences are related to t...

  9. Calcium restriction prolongs metaphase in dividing Tradescantia stamen hair cells

    OpenAIRE

    1985-01-01

    Agents that lower extracellular calcium concentration (EGTA) or modulate calcium transport (lanthanum or D600) have been applied to dividing stamen hair cells of Tradescantia and analyzed for their ability to change the following: (a) the time required to progress from nuclear envelope breakdown to the onset of anaphase (metaphase transit time), (b) the time required to progress from anaphase to the initiation of the cell plate, and (c) the rate of chromosome motion in anaphase. Control cells...

  10. 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...

  11. 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 ...

  12. 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...

  13. Europeanization and Conflict Resolution: Case Studies from the Divided Periphery

    OpenAIRE

    COPPIETERS, Bruno; Huysseune, Michel; Kovziridze, Tamara; NOUTCHEVA, Gergana; Tocci, Nathalie; Emerson, Michael; VAHL, Marius

    2004-01-01

    The enlarging EU is increasingly drawn into secessionist conflicts on its southern and eastern peripheries. This book examines the relevance of European integration for conflict settlement and resolution in divided states through a comparison of four case studies: Cyprus, Serbia and Montenegro, Moldova and the Transnistrian conflict and the Georgia-Abkhaz conflict. The authors explore the historical background of each of these conflicts and examine the degree of Europeanization, the mediation...

  14. 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...

  15. 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 technology–skilled 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...

  16. 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...

  17. Internet für 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 für den deutschsprachigen Raum übersetzt wird, wird nun schon seit nahezu zehn Jahren intensiv geführt.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...

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

    OpenAIRE

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

  19. 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.

  20. 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.

  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. 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.

  3. 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.

  4. Informaticiens Sans Frontières. Helping to bridge the Digital Divide

    CERN Document Server

    Josiane Uwantege

    2009-01-01

    SF 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.

  5. 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.)

  6. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Rossillon, F., E-mail: frederique.rossillon@edf.fr [EDF SEPTEN, 12-14 Avenue Dutrievoz, Villeurbanne (France); Depradeux, L. [EC2-MS, 66 Bd Niels Bohr, Villeurbanne (France); Miloudi, S. [EDF CEIDRE, CNPE de Chinon, Avoine (France); Deforge, D. [EDF CEIDRE, 2 Rue Ampère, Saint Denis (France); Lemaire, E. [EDF UNIE, Cap Ampère, Saint Denis (France); Massoud, J.P. [EDF SEPTEN, 12-14 Avenue Dutrievoz, Villeurbanne (France)

    2014-04-01

    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.

  8. Quantum Cyclic Code of length dividing $p^{t}+1$

    CERN Document Server

    Dutta, Sagarmoy

    2010-01-01

    In this paper, we study linear cyclic stabiliser codes of length dividing $p^t+1$, for a positive integer $t$. We prove that if $t$ is odd, no such codes exists and give a complete characterisation when $t$ is even. Our characterisation of these codes directly gives us explicit constructions which includes the well studied Laflamme code. Furthermore, we also show that any linear cyclic stabiliser code over $\\mathbb{F}_p$ whose length divides $p^{2m}+1$ can never be a CSS code unless it has distance $1$ and hence trivial. The characterisation of these codes also gives us efficient decoding algorithms. More precisely, we can extend the notion of BCH distance of classical cyclic codes to these codes and correct errors within the BCH limit. In order to construct these codes, we start from a general notion of cyclicity for quantum code. This can be of independent interest as our notion of cyclicity is applicable to non-stabiliser codes as well.

  9. Chirped and divided-pulse Sagnac fiber amplifier

    Science.gov (United States)

    Guichard, Florent; Zaouter, Yoann; Hanna, Marc; Mai, Khanh-Lin; Morin, Franck; Hönninger, Clemens; Mottay, Eric; Georges, Patrick

    2015-03-01

    Femtosecond fiber chirped pulse amplifiers have numerous advantages, but are limited in energy because of the small interaction area with the fiber core. In this contribution, we create two orthogonally-polarized stretched pulse replicas in the time domain, following the divided-pulse amplification (DPA) principle. This beam is subsequently separated into two counter-propagating beams in a Sagnac interferometer to finally generate four pulse replicas. These pulses are amplified in two state-of-the-art large mode area rod-type fiber amplifiers in series, before final coherent combination and compression. Because the stretched-pulse duration is of the order of hundreds of picoseconds, the DPA delay is induced using a freespace interferometer with reasonable arm lengths of few tens of centimeters. The use of a common interferometer to divide and recombine temporal pulse replicas, together with the Sagnac geometry, results in an identical optical path for all four replicas. Therefore, the whole spatio-temporal combining architecture is passive, avoiding the need for active electronic stabilization systems. Because we only use two temporal replicas, the system is immune to differential saturation levels or B-integrals between successive pulses: this is compensated by controlling the amplitude of both pulses at the input of the amplifying setup. This setup allows the generation of 1 mJ, 300 fs compressed pulses at 50 kHz repetition rate, corresponding to 50 W output average power, with a combining efficiency above 90% at all power levels.

  10. 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.

  11. Water

    Science.gov (United States)

    ... know if my tap water is contaminated with lead? The only way to know whether your tap water contains lead ... exposure. Therefore, for homes with children or pregnant women and with water lead levels exceeding EPA’s action level of 15 ppb, ...

  12. Attitude estimation by divided difference filter in quaternion space

    Science.gov (United States)

    Ahmadi, Mohammad; Khayatian, Alireza; Karimaghaee, Paknoush

    2012-06-01

    This article considers the application of Divided Difference Filter (DDF) to the orientation estimation, based on a quaternion-error continuous-discrete time model. DDF is a nonlinear estimator that in contrast to Taylor's expansion of extended Kalman Filter (EKF), exploit the polynomial approximations as a multivariable extension of Stirling's interpolation formula and require no derivatives. The DDF can be based on 1st and 2nd order Stirling's interpolation, which is named the divided difference filter-1st order (DDF1) and the divided difference filter-2nd order (DDF2). The orientation kinematics is defined in a quaternion vector space that unlike the Euler angle representation does not have any singularity problem. The presented nonlinear orientation model is an exact error model and is independent of the rigid body dynamics. The nonlinear process model includes six error-states in which only non-scalar elements of quaternion error vector are included in the error-state equations. The fourth element of quaternion error vector, which obeys unit norm constraint, is removed from system states to alleviate the estimated error covariance matrix divergence. The measurement system is a MARG sensor, which consists of a tri-axial rate gyro, a tri-axial accelerometer and a tri-axial magnetometer. The nonlinear measurement model is obtained based on the principals of magnetometer and accelerometer and the properties of the quaternion vector space. For the presented nonlinear orientation model, the performance of three filters namely DDF, EKF and Unscented Kalman Filter (UKF) is compared for different sampling frequencies in terms of the rms error, the captured area under the error norm curve, the estimated state variance and the computational cost. It is shown that under the same initial angle-error conditions, DDFs and UKF are more robust than EKF. The DDFs perform better than unscented Kalman filter (UKF) although the computational load for UKF is less. Among DDF1 and DDF2, DDF2's performance is slightly better but with more computation load. In the case of no initial angle-error conditions, the performance of the four filters is the same especially when the low noise level condition is considered.

  13. 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.

  14. Digital Divide between Teachers and Students in Urban Bangladesh

    DEFF Research Database (Denmark)

    Khalid, Md. Saifuddin

    2011-01-01

    Telecom boom since 2000 and ‘Digital Bangladesh’ campaign since late 2008 created significant nationwide hype, resulting rapid increase in the use of digital devices. While studies are being conducted to use the ability of “power users of technology” for reducing digital divide, there is hardly any 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 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 questionnaire was developed based on initial semi-structured interview with randomly selected students from these academic institutions. The 41-question questionnaire was developed to study the usage of computer, internet, mobile and other handheld devices, radio, television and CD/DVD players. A slightly different questionnaire was developed for teachers. 965 students and 185 teachers participated in the survey. Among student respondents 37% were from English Medium and 63% from Bangla medium institutions. From class VI –XII, the survey group represent the secondary and higher secondary education level in Bangladesh. Male respondents were 53% and female 43%, remaining are missing. Responses collected using paper-based questionnaires were put on a learning management system’s (LMS) questionnaire survey module. Irrespective of type of ICT device higher percentage of English medium students ‘own’ and know ‘how to use’ compared to Bangla medium students. Significantly higher percentage of students can use and own desktop, laptop, cellphone, iPOD and MP3 player. While teachers mostly use computers for work (73%), study (45%) and listening music (34%), students use for playing games (63%), listening musing (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% teachers and 61% students have more than one SIM card. More than 50% of students and teachers use mobile for listening radio. 55% or more teachers and 67% or more students ‘own’ a desktop. 90% or more teachers and 74% or more students ‘know how to use’ desktop computer. Further study is required to gain insight into digital divide and associated reasons in four different educations systems in Bangladesh.

  15. Nationality Divides and Shared Leadership in Multinational Teams

    DEFF Research Database (Denmark)

    Paunova, Minna

    2015-01-01

    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...... 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...... 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...

  16. 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

  17. Flagellation of Pseudomonas aeruginosa in newly divided cells

    Science.gov (United States)

    Zhao, Kun; Lee, Calvin; Anda, Jaime; Wong, Gerard

    2015-03-01

    For monotrichous bacteria, Pseudomonas aeruginosa, after cell division, one daughter cell inherits the old flagellum from its mother cell, and the other grows a new flagellum during or after cell division. It had been shown that the new flagellum grows at the distal pole of the dividing cell when the two daughter cells haven't completely separated. However, for those daughter cells who grow new flagella after division, it still remains unknown at which pole the new flagellum will grow. Here, by combining our newly developed bacteria family tree tracking techniques with genetic manipulation method, we showed that for the daughter cell who did not inherit the old flagellum, a new flagellum has about 90% chances to grow at the newly formed pole. We proposed a model for flagellation of P. aeruginosa.

  18. 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.

  19. Digital Divide between Teachers and Students in Urban Bangladesh

    DEFF Research Database (Denmark)

    Khalid, Md. Saifuddin

    different questionnaire was developed for teachers. 965 students and 185 teachers participated in the survey. Among student respondents 37% were from English Medium and 63% from Bangla medium institutions. From class VI –XII, the survey group represent the secondary and higher secondary education level in...... 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. Bayesian Blocks Divide and Conquer, MCMC, and Cell Coalescence Approaches

    CERN Document Server

    Scargle, J D

    2000-01-01

    Identification of local structure in intensive data -- such as time series, images, and higher dimensional processes -- is an important problem in astronomy. Since the data are typically generated by an inhomogeneous Poisson process, an appropriate model is one that partitions the data space into cells, each of which is described by a homogeneous (constant event rate) Poisson process. It is key that the sizes and locations of the cells are determined by the data, and are not predefined or even constrained to be evenly spaced. For one-dimensional time series, the method amounts to Bayesian changepoint detection. Three approaches to solving the multiple changepoint problem are sketched, based on: (1) divide and conquer with single changepoints, (2) maximum posterior for the number of changepoints, and (3) cell coalescence. The last method starts from the Voronoi tessellation of the data, and thus should easily generalize to spaces of higher dimension.

  1. 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

  2. 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

  3. Nationality Divides and Shared Leadership in Multinational Team

    DEFF Research Database (Denmark)

    Paunova, Minna

    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 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 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 status ranks also affects shared leadership, but not as hypothesized.

  4. How Visibility and Divided Attention Constrain Social Contagion

    CERN Document Server

    Hodas, Nathan Oken

    2012-01-01

    How far and how fast does information spread in social media? Researchers have recently examined a number of factors that affect information diffusion in online social networks, including: the novelty of information, users' activity levels, who they pay attention to, and how they respond to friends' recommendations. Using URLs as markers of information, we carry out a detailed study of retweeting, the primary mechanism by which information spreads on the Twitter follower graph. Our empirical study examines how users respond to an incoming stimulus, i.e., a tweet (message) from a friend, and reveals that %retweeting behavior is constrained by a few simple principles. the "principle of least effort" combined with limited attention plays a dominant role in retweeting behavior. Specifically, we observe that users retweet information when it is most visible, such as when it near the top of their Twitter stream. Moreover, our measurements quantify how a user's limited attention is divided among incoming tweets, pro...

  5. 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.

  6. 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

  7. 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

  8. 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.

  9. 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

  10. Can Water Store Charge?

    Science.gov (United States)

    Ovchinnikova, Kate; Pollack, Gerald H.

    2010-01-01

    Previous work from this and other laboratories has demonstrated large pH gradients in water. Established by passing current between immersed electrodes, pH gradients between electrodes were found to disappear slowly, persisting for tens of minutes after the current had been turned off. We find here that these pH gradients reflect a genuine separation of charge: at times well after disconnection of the power supply, current could be drawn through a resistor placed between the charging electrodes or between pairs of electrodes positioned on either side of the midline between original electrodes. In some experiments, it was possible to recover the majority of charge that had been imparted to the water. It appears, then, that water has the capacity to store and release substantial amounts of charge. PMID:19053655

  11. 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…

  12. 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...

  13. 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 K?. 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 ?sec. 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)

  14. Application System Architecture for Cellular Phones by Dividing Interaction Logics

    Science.gov (United States)

    Kitamura, Misayo; Todoroki, Nobutoshi; Akiyoshi, Masanori; Kojima, Taizo

    This paper describes application system architecture using cellular phones as user interface devices, which enables users to interact with the system by graphic symbols on a client screen. Our approach has the following features: (i) divided interaction logics running on a server and a Java phone client; both interaction logics cooperate to accomplish a user's operation using a simplified script, (ii) local interaction which enables users to handle figures on a client screen without connecting to a server, and (iii) device-independent script which hides the differences of API sets among various cellular phones. By using this architecture, complicated figures including lots of graphic symbols can be displayed in spite of program-size limitation on a client device, and application programs including same interaction logics are just described once for various cellular phones. Our experiments show the advantage of the local interaction. A client program can respond immediately when handling complicated figures. The ratio of requests to the server is reduced to 23%. It takes less than 9 seconds to display typical contents, which is good enough for practical use. This method also reduces development costs at the second development or later.

  15. 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

  16. 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.

  17. Thalamic control of sensory selection in divided attention.

    Science.gov (United States)

    Wimmer, Ralf D; Schmitt, L Ian; Davidson, Thomas J; Nakajima, Miho; Deisseroth, Karl; Halassa, Michael M

    2015-10-29

    How the brain selects appropriate sensory inputs and suppresses distractors is unknown. Given the well-established role of the prefrontal cortex (PFC) in executive function, its interactions with sensory cortical areas during attention have been hypothesized to control sensory selection. To test this idea and, more generally, dissect the circuits underlying sensory selection, we developed a cross-modal divided-attention task in mice that allowed genetic access to this cognitive process. By optogenetically perturbing PFC function in a temporally precise window, the ability of mice to select appropriately between conflicting visual and auditory stimuli was diminished. Equivalent sensory thalamocortical manipulations showed that behaviour was causally dependent on PFC interactions with the sensory thalamus, not sensory cortex. Consistent with this notion, we found neurons of the visual thalamic reticular nucleus (visTRN) to exhibit PFC-dependent changes in firing rate predictive of the modality selected. visTRN activity was causal to performance as confirmed by bidirectional optogenetic manipulations of this subnetwork. Using a combination of electrophysiology and intracellular chloride photometry, we demonstrated that visTRN dynamically controls visual thalamic gain through feedforward inhibition. Our experiments introduce a new subcortical model of sensory selection, in which the PFC biases thalamic reticular subnetworks to control thalamic sensory gain, selecting appropriate inputs for further processing. PMID:26503050

  18. Multidimensional Divide-and-Conquer and Weighted Digital Sums

    CERN Document Server

    Cheung, Y K; Golin, Mordecai; Lee, C Y James

    2010-01-01

    This paper studies three types of functions arising separately in the analysis of algorithms that we analyze exactly using similar Mellin transform techniques. The first is the solution to a Multidimensional Divide-and-Conquer (MDC) recurrence that arises when solving problems on points in $d$-dimensional space. The second involves weighted digital sums. Write $n$ in its binary representation $n=(b_i b_{i-1}... b_1 b_0)_2$ and set $S_M(n) = \\sum_{t=0}^i t^{\\bar{M}} b_t 2^t$. We analyze the average $TS_M(n) = \\frac{1}{n}\\sum_{j i_2 > ... > i_k\\geq 0$ and set $W_M(n) = \\sum_{t=1}^k t^M 2^{i_t}$. We analyze the average $TW_M(n) = \\frac{1}{n}\\sum_{j

  19. The Digital Divide in Romania – A Statistical Analysis

    Directory of Open Access Journals (Sweden)

    Daniela BORISOV

    2012-06-01

    Full Text Available The digital divide is a subject of major importance in the current economic circumstances in which Information and Communication Technologies (ICT are seen as a significant determinant of increasing the domestic competitiveness and contribute to better life quality. Latest international reports regarding various aspects of ICT usage in modern society reveal a decrease of overall digital disparity towards the average trends of the worldwide ITC’s sector – this relates to latest advances of mobile and computer penetration rates, both for personal use and for households/ business. In Romania, the low starting point in the development of economy and society in the ICT direction was, in some extent, compensated by the rapid annual growth of the last decade. Even with these dynamic developments, the statistical data still indicate poor positions in European Union hierarchy; in this respect, the prospects of a rapid recovery of the low performance of the Romanian ICT endowment and usage and the issue continue to be regarded as a challenge for progress in economic and societal terms. The paper presents several methods for assessing the current state of ICT related aspects in terms of Internet usage based on the latest data provided by international databases. The current position of Romanian economy is judged according to several economy using statistical methods based on variability measurements: the descriptive statistics indicators, static measures of disparities and distance metrics.

  20. 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 ...

  1. Water

    Science.gov (United States)

    ... dirty and unsafe for drinking and/or swimming: Natural events . Floods, hurricanes, earthquakes, or landslides can cause dirt to get into our drinking water. Pesticides and fertilizers. Americans use 67 million pounds of ...

  2. 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

  3. 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

  4. 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

  5. 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.

  6. Crossing the Digital Divide: Connecting GIS, Time Series and Space-Time Arrays (Invited)

    Science.gov (United States)

    Maidment, D. R.; Salas, F.; Domenico, B.; Nativi, S.

    2010-12-01

    Hydrologic information science requires several different kinds of information: GIS coverages of water features of the land surface and subsurface; time series of observations of streamflow, water quality, groundwater levels and climate; and space-time arrays of weather, climate and remotely sensed information. Increasingly, such information is being published as web services, in standardized data structures that transmit smoothly through the internet. A large "Digital Divide" exists between the world of discrete spatial objects in GIS and associated time series, and the world of continuous space-time arrays as is used weather and climate science. In order to cross this divide, it should be possible to search for quantities such as “precipitation” and to find the information no matter whether it comprises time series of precipitation at gage sites, or space-time arrays of precipitation from Nexrad radar rainfall measurements. This means that servers of discrete space-time hydrologic data, such as the CUAHSI HydroServer, and servers of continuous space-time weather and climate data, such as the Unidata THREDDS server, should be able to be indexed in a unified manner that will permit discovery of common information types across different classes of information services. This paper will explore options for accomplishing this goal using the CUAHSI HydroServer and the Unidata THREDDS server as representative examples of information service providers. Among the options to be explored is GI-cat, a federated, standards-based catalog service developed at the Earth and Space Science Informatics Laboratory of the University of Florence.

  7. 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)

  8. Research on Dividing Modeling of Female Suits Based on Cognitive Psychology

    OpenAIRE

    Gu Pin-Ying; Chen Ting; Gu Bin-Fei; Liu Guo-Lian

    2013-01-01

    According to apparel modeling aesthetics of consumers, in this paper, the detail modeling dividing lines of female suits were selected as subject. And with the evaluating indexes defined, the dividing modeling was classified and the control points of dividing lines were found. Then 90 images of women suits with different dividing modeling were drawn. And the experimental data of 64 students aged from 19 to 26 years old from Soochow University were collected by software named E-prime. At last,...

  9. A divide-conquer-recombine algorithmic paradigm for large spatiotemporal quantum molecular dynamics simulations

    International Nuclear Information System (INIS)

    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. 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.

  11. Comparability of the black-white divide in the American speech community and the coloured-white divide in the Afrikaans speech community

    OpenAIRE

    Stell, Gerald

    2012-01-01

    This article attempts to place the discussion on the relationship between African American and European American vernacular Englishes within a broader context involving another speech community split along ethnic lines, namely South Africa’s Afrikaans speakers. It specifically attempts to compare observations on the coloured-white linguistic divide within South Africa’s Afrikaans speech community with those made on the black-white linguistic divide in the United States, with th...

  12. 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)

  13. Measure the Performance of Reducing Digital Divide – the BSC and AHP Approach

    Directory of Open Access Journals (Sweden)

    Hsing-I Wang

    2011-03-01

    Full Text Available Digital divides are the byproducts of the development of information technologies and digitalization. What concern most of the governments and the international organizations are the disturbance of the advancement of national competitiveness as well as the improvement of human lives caused by the presence of digital divides.Countries world wide have proposed numerous of strategies to reduce digital divides. However, the absence of the follow-up of the performance of the strategies forms another issue in reducing digital divides. Previous researches built digital divide balance scorecard to realize the objectives as well as to improve the performance of the strategies. This research adopts the analytical hierarchy process to prioritize the performance indicators which have been determined in the digital divide balance scorecard. The architecture proposed by the research would be applied to examine the merits of the strategies.

  14. Dividing time: Concurrent timing of auditory and visual events by young and elderly adults

    OpenAIRE

    McAuley, J Devin; Miller, Jonathan P.; Wang, Mo; Kevin C.H. Pang

    2010-01-01

    This article examines age differences in individual’s ability to produce the durations of learned auditory and visual target events either in isolation (focused attention) or concurrently (divided attention). Young adults produced learned target durations equally well in focused and divided attention conditions. Older adults in contrast showed an age-related increase in timing variability in divided attention conditions that tended to be more pronounced for visual targets than for auditory ta...

  15. 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...

  16. 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 ...

  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. 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...

  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 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.)

  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. 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,…

  3. Social Impact of the "Digital Divide" in a Central-Eastern European Country.

    Science.gov (United States)

    Dragulanescu, Nicolae-George

    2002-01-01

    Discusses the social impact of the digital divide in Central-Eastern European countries as well as between them and industrialized developed countries, based on experiences in Romania. Highlights include facts relating to digital divide worldwide; transition to a democratic and market-based economy and from socialism to capitalism; barriers to…

  4. 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...

  5. 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)

  6. 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...

  7. 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…

  8. 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…

  9. 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…

  10. 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…

  11. 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…

  12. 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,…

  13. 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…

  14. 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…

  15. 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.

  16. 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…

  17. 100kW dummy load using water for a klystron modulator

    International Nuclear Information System (INIS)

    A dummy load capable of handling the peak voltage of 37 kV and the average power of 100 kW using water as a resistor has been designed and constructed to perform the high-power tests of an X-band klystron modulator. Two coaxial electrodes are used to make the dummy load in a compact size. The load impedance is regulated in the range of 5 ? 12 ? stably. (author)

  18. A 5-GHz programmable frequency divider in 0.18-?m CMOS technology

    International Nuclear Information System (INIS)

    A 5-GHz CMOS programmable frequency divider whose modulus can be varied from 2403 to 2480 for 2.4-GHz ZigBee applications is presented. The divider based on a dual-modulus prescaler (DMP) and pulse-swallow counter is designed to reduce power consumption and chip area. Implemented in the 0.18-?m mixed-signal CMOS process, the divider operates over a wide range of 1-7.4 GHz with an input signal of 7.5 dBm; the programmable divider output phase noise is -125.3 dBc/Hz at an offset of 100 kHz. The core circuit without test buffer consumes 4.3 mA current from a 1.8 V power supply and occupies a chip area of approximately 0.015 mm2. The experimental results indicate that the programmable divider works well for its application in frequency synthesizers. (semiconductor integrated circuits)

  19. Research on Dividing Modeling of Female Suits Based on Cognitive Psychology

    Directory of Open Access Journals (Sweden)

    Gu Pin-Ying

    2013-01-01

    Full Text Available According to apparel modeling aesthetics of consumers, in this paper, the detail modeling dividing lines of female suits were selected as subject. And with the evaluating indexes defined, the dividing modeling was classified and the control points of dividing lines were found. Then 90 images of women suits with different dividing modeling were drawn. And the experimental data of 64 students aged from 19 to 26 years old from Soochow University were collected by software named E-prime. At last, with data processing software called Excel and SPSS, the differences of evaluating indexes were analyzed and the best positions of control points were found. Thus, the best dividing modeling of women suits were obtained.

  20. Retroviral infection of non-dividing cells: Old and new perspectives

    International Nuclear Information System (INIS)

    The dependence of retroviral replication on cell proliferation was described as early as 1958, although different classes of retroviruses are able to infect non-dividing cells with different efficiencies. For example, the human immunodeficiency virus (HIV) and other lentiviruses infect most non-dividing cells nearly as well as dividing cells, while the gammaretroviruses such as the murine leukemia virus (MLV) cannot infect non-dividing cells, and other retroviruses have intermediate phenotypes. One exception to the ability of HIV to infect non-dividing cells involves resting CD4+ T cells in vitro where there are multiple restrictions. However, recent data show that there is massive infection of non-activated CD4+ T cell during acute infection which suggests that the situation is different in vivo. Finally, much work trying to explain the difference between HIV and MLV in non-dividing cells has focused on describing the ability of HIV to enter the nucleus during interphase. However, we suggest that events in the viral lifecycle other than nuclear import may be more important in determining the ability of a given retrovirus to infect non-dividing cells

  1. ASSESSING THE NEED, CHALLENGES AND SOLUTIONS TO BRIDGE THE DIVIDE OF DIGITAL INEQUALITY

    Directory of Open Access Journals (Sweden)

    Surya Singh

    2015-03-01

    Full Text Available Digital resources are playing a gigantic role in the present Knowledge Society. But there is wide disparity in terms of access to the digital technology. In one hand we have very skilled human resource which is making use of digital resources effectively; on the other hand we have group of people those who don’t have skill and access to the digital technology. In 21st century’s knowledge society, digital resources dividing human society in to two groups called ‘Digital Haves’and ‘Digital Have Not’s. The is the “Digital Divide’’that refers to the difference between individuals within or outside the families, businesses and geographic areas in various socio-economic levels with regard to both their opportunities in accessing Information and Communication Technologies (ICTs and also the use of the internet for multiple purposes. This paper focuses on bridging the Digital Divide. One of the main challenges is frightening gap between the information have-s and information have-nots, what we call the digital divide. Purpose of this study is to highlight and identify some major issues of digital divide and efforts to bridging the digital divide. It concludes by providing the some possible solutions in bridging the digital divide.

  2. An InGaAs/InP 40 GHz CML static frequency divider

    Science.gov (United States)

    Yongbo, Su; Zhi, Jin; Wei, Cheng; Ji, Ge; Xiantai, Wang; Gaopeng, Chen; Xinyu, Liu; Anhuai, Xu; Ming, Qi

    2011-03-01

    Static frequency dividers are widely used as a circuit performance benchmark or figure-of-merit indicator to gauge a particular device technology's ability to implement high speed digital and integrated high performance mixed-signal circuits. We report a 2 : 1 static frequency divider in InGaAs/InP heterojunction bipolar transistor technology. This is the first InP based digital integrated circuit ever reported on the mainland of China. The divider is implemented in differential current mode logic (CML) with 30 transistors. The circuit operated at a peak clock frequency of 40 GHz and dissipated 650 mW from a single -5 V supply.

  3. Illusory recollection in older adults and younger adults under divided attention.

    Science.gov (United States)

    Skinner, Erin I; Fernandes, Myra A

    2009-03-01

    The authors investigated the effect of divided attention, study-list repetition, and age on recollection and familiarity. Older and younger adults under full attention and younger adults under divided attention at study viewed word lists highly associated with a single unstudied word (critical lure) once or three times, and subsequently performed a remember-know recognition test. Younger adults made fewer false remember responses to critical lures from repeated study lists, whereas younger adults under divided attention and older adults both showed an increase with repetition. Findings suggest older adults' susceptibility to illusory memories is related to a deficit in available attention during encoding. PMID:19290753

  4. Divide-and-Conquer 3D Convex Hulls on the GPU

    OpenAIRE

    White, Jeffrey M.; Wortman, Kevin A.

    2012-01-01

    We describe a pure divide-and-conquer parallel algorithm for computing 3D convex hulls. We implement that algorithm on GPU hardware, and find a significant speedup over comparable CPU implementations.

  5. Kinematic Identification of Parallel Mechanisms by a Divide and Conquer Strategy

    DEFF Research Database (Denmark)

    Durango, Sebastian; Restrepo, David; Ruiz, Oscar; Restrepo-Giraldo, John Dairo; Achiche, Sofiane

    calibration method as the Divide and Conquer strategy for the kinematic identification of parallel symmetrical mechanisms and, (ii) a new kinematic identification protocol based on the Divide and Conquer strategy. As an application of the proposed kinematic identification protocol the identification of a......This paper presents a Divide and Conquer strategy to estimate the kinematic parameters of parallel symmetrical mechanisms. The Divide and Conquer kinematic identification is designed and performed independently for each leg of the mechanism. The estimation of the kinematic parameters is performed...... strategy are: (i) reduction of the kinematic identification computational costs, (ii) improvement of the numerical efficiency of the kinematic identification algorithm and, (iii) improvement of the kinematic identification results. The contributions of the paper are: (i) The formalization of the inverse...

  6. "Is There a Second Level Divide in Student’s Internet Skills?

    DEFF Research Database (Denmark)

    Purushothaman, Aparna; Dau, Susanne

    The concept of a digital divide has moved beyond only physical disparities in technology usage and now also encompasses issues impeding access such as human social, cultural, and psychological barriers that affect the usage of existing available technologies. This paper focuses on students......’ insufficient skill levels in making the best use of available Internet technology, discussing students in higher education in scenarios in Denmark and India. The paper emphasizes the reflective and conceptual issues which the students face in retrieving information from the Internet, which result in a second......-level divide. Through a cross-national comparison, the paper hopes to contribute to the literature through experiences of students in the two countries, providing researchers with insights into the digital divide. This divide in Internet skills is illuminated from different perspectives in the context of two...

  7. Poor need knowledge not only technology to bridge digital divide: experts

    CERN Multimedia

    2003-01-01

    "Developing countries need to gain knowledge rather than technology to latch onto the booming information society, experts said Monday ahead of a major conference on bridging the digital divide between rich and poor" (1/2 page).

  8. Variable-geometry turbocharger with asymmetric divided volute for engine exhaust gas pulse optimization

    Science.gov (United States)

    Serres, Nicolas (Epinal, FR)

    2010-11-09

    A turbine assembly for a variable-geometry turbocharger includes a turbine housing defining a divided volute having first and second scrolls, wherein the first scroll has a substantially smaller volume than the second scroll. The first scroll feeds exhaust gas to a first portion of a turbine wheel upstream of the throat of the wheel, while the second scroll feeds gas to a second portion of the wheel at least part of which is downstream of the throat. Flow from the second scroll is regulated by a sliding piston. The first scroll can be optimized for low-flow conditions such that the turbocharger can operate effectively like a small fixed-geometry turbocharger when the piston is closed. The turbine housing defines an inlet that is divided by a dividing wall into two portions respectively feeding gas to the two scrolls, a leading edge of the dividing wall being downstream of the inlet mouth.

  9. Drosophila midgut homeostasis involves neutral competition between symmetrically dividing intestinal stem cells

    OpenAIRE

    de Navascués, Joaquín; Perdigoto, Carolina N.; Bian, Yu; Schneider, Markus H; Bardin, Allison J; Martínez-Arias, Alfonso; Simons, Benjamin D.

    2012-01-01

    Quantitative analyses on clonal fate of Drosophila midgut intestinal stem cells suggest that neutral competition of symmetrically dividing cells contributes to physiological tissue dynamics. The study thus adds to current models on stem-cell behaviour in flies and vertebrates.

  10. The effect of divided attention on false memory depends on how memory is tested.

    Science.gov (United States)

    Dewhurst, Stephen A; Barry, Christopher; Swannell, Ellen R; Holmes, Selna J; Bathurst, Gemma L

    2007-06-01

    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, in which the type of secondary task was manipulated within groups. We argue that the increase in false recall with divided attention reflects a change in participants' response criterion, whereas the decrease in false recognition occurs because the secondary tasks prevent participants from generating associates of the words presented at study. PMID:17848024

  11. Beyond the digital divide: harnessing the Internet for cross-cultural dialogue

    OpenAIRE

    Cawson, Alan

    2006-01-01

    The author explores the nature of the digital divide and discusses how the potential of the Internet can be realised in the field of education and cross-cultural communication between North and South. (DIPF/Orig.)

  12. Review: Funston, John (ed. (2009, Divided Over Thaksin: Thailand’s Coup and Problematic Transition

    Directory of Open Access Journals (Sweden)

    Paul Chambers

    2010-04-01

    Full Text Available Review of the edited volume: Funston, John (ed. (2009, Divided Over Thaksin: Thailand’s Coup and Problematic Transition, Chiangmai: Silkworm Books, Singapore: ISEAS. ISBN 978-981-230-961-7, 203 pages.

  13. Harmonic-suppressed quadrature-input frequency divider for OFDM systems

    International Nuclear Information System (INIS)

    A fully balanced harmonic-suppressed quadrature-input frequency divider is proposed. The frequency divider improves the quadrature phase accuracy at the output by using both input I/Q signals. Compared with conventional dividers, the circuit achieves an output I/Q phase sequence that is independent of the input I/Q phase sequence. Moreover, the third harmonic is effectively suppressed by employing a double degeneration technique. The design is fabricated in TSMC 0.13-?m CMOS and operated at 1.2 V. While locked at 8.5 GHz, the proposed divider measures a maximum third harmonic rejection of 45 dB and a phase noise of ?124 dBc/Hz at a 10 MHz offset. The circuit achieves a locking range of 15% while consuming a total current of 4.5 mA. (semiconductor integrated circuits)

  14. 5 CFR Appendix A to Subpart F of... - Recommended Language for Court Orders Dividing Employee Annuities

    Science.gov (United States)

    2010-01-01

    ...Recommended Language for Court Orders Dividing Employee Annuities A Appendix A to Subpart F of Part... Terminology Used in Court Orders Affecting Employee Annuities or Refunds of Employee Contributions Pt. 838, Subpt. F,...

  15. Information Resources Column: "The Digital Divide: How Wide and How Deep?

    OpenAIRE

    Schloman, B

    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,...

  16. Divided Government, Legislative Productivity, and Policy Change in the USA and France

    OpenAIRE

    Baumgartner, Frank; Brouard, Sylvain; Grossman, Emiliano; Lazardeux, Sébastien; Moody, Jonathan

    1988-01-01

    The concept of "divided government" is more complicated than scholars have allowed. In the USA, truly unified government, where the president enjoys a filibuster-proof majority in the Senate as well as a majority in the House, is rare. In France, truly unified government has been more common, but divided government has also occurred several times. Democratic governance requires that parties address important issues and they do so regardless of the patterns of institutional control. Neverthele...

  17. Exploring the Future of the Digital Divide through Ethnographic Futures Research

    OpenAIRE

    Mitchell, Matthew

    2002-01-01

    This study examines leaders who work for social change in an information society. Grounded in the notion that leadership and social change are necessarily future oriented, this study attempts to learn how those who lead the effort to ameliorate the digital divide in Washington State perceive the optimistic, pessimistic, and most probable futures. In this study, the digital divide is framed as a social problem that is caused, in part, by inequities in the ability to access and to use informati...

  18. How to Overcome the Digital Divide? The Determinants of Internet Diffusion

    OpenAIRE

    Shchetinin, Oleg; Baptiste, Massenot

    2008-01-01

    We document the existence and the persistence of the digital divide and investigate the determinants of the Internet diffusion in both developing and developed countries. Our study innovates on the following: i) we use a data set that covers more countries and years than the earlier studies ii) We use the GMM estimator which requires milder assumptions to be consistent than the traditionally used panel data estimators in technology diffusion studies. We find that i) the digital divide is ...

  19. Effective use: A community informatics strategy beyond the Digital Divide (originally published in December 2003)

    OpenAIRE

    Gurstein, Michael

    2007-01-01

    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...

  20. Digital divide or digital development?: The Internet in Mexico (originally published in March 2006)

    OpenAIRE

    Curry, James; Kenney, Martin

    2007-01-01

    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...

  1. Closing the digital divide: Southeast Asia's path towards a knowledge society

    OpenAIRE

    Evers, Hans-Dieter; Gerke, Solvay

    2005-01-01

    The production, dissemination and utilisation of knowledge are essential for development and the introduction of information and communication technology (ICT) is a precondition for developing a knowledge society. Countries, regions and populations are, however, divided, in terms of access to ICT. Socio-economic indicators on Korea, Malaysia, Singapore, the Netherlands and Germany are used to show that the existing global digital divide and the knowledge gap are widening between developing co...

  2. The geographical digital divide in broadband access and governmental policies in Japan: three case studies

    OpenAIRE

    Arai, Yoshio; Naganuma, Sae

    2013-01-01

    Broadband access is indispensable for advanced Internet services, because voluminous data transfers have recently become popular in developed societies. Although broadband access has spread to a certain degree in developed countries/regions, geographical gaps in broadband access (the so-called “geographical digital divide”) remain. Based on three case studies in less-favoured areas of Japan (Hokkaido, Nagano Prefecture and Mie Prefecture), we examined how the geographical digital divide is be...

  3. The robotics divide a new frontier in the 21st century?

    CERN Document Server

    López Peláez, Antonio

    2013-01-01

    Analyzes how robotics will shape our societies in the twenty-first century; a time when industrial and service robotics, particularly for military and aerospace purposes, will become an essential technology Examines an emerging divide: the "robotics divide"; a phenomenon linked to the model to integrate advanced robotics in economic, social and military spheres Focuses on the main technological trends in the field of robotics, and the impact that robotics will have on different facets of social life

  4. Cortical sites of sustained and divided attention in normal elderly humans

    DEFF Research Database (Denmark)

    Johannsen, Peter; Jakobsen, Johannes Klitgaard; Bruhn, Peter; Hansen, Søren Baarsgaard; Gee, A; Stødkilde-Jørgensen, Hans; Gjedde, Albert

    1997-01-01

    Human brain mechanisms subserving attention have been assigned to prefrontal, midfrontal, and posterior parietal cortices, as well as to the anterior cingulate and the thalamus. To map these mechanisms in the brain, most studies have used selective attention tasks; few studies have mapped the brain under sustained or divided attention. The present study was designed to create maps of regional activity associated with sustained and divided attention using two different sensory modalities: visual ...

  5. A Study to Examine the Digital Divide Factors: Jammu and Kashmir Perspective

    OpenAIRE

    Preeti Dubey; JeevanJyoti; Devanand

    2011-01-01

    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 resour...

  6. Statistical and numerical methods to improve the transient divided bar method

    DEFF Research Database (Denmark)

    Bording, Thue Sylvester; Nielsen, S.B.

    The divided bar method is a commonly used method to measure thermal conductivity of rock samples in laboratory. We present improvements to this method that allows for simultaneous measurements of both thermal conductivity and thermal diffusivity. The divided bar setup is run in a transient mode and the temperature distribution in the stack is simulated by Finite Element Modeling (FEM). A Markov Chain Monte Carlo Metropolis Hastings (MCMCMH) algorithm is used to estimate the thermal parameters of the sample.

  7. Modulation of early cortical processing during divided attention to non-contiguous locations

    OpenAIRE

    Frey, Hans-Peter; Schmid, Anita M.; Murphy, Jeremy W.; Molholm, Sophie; Lalor, Edmund C; John J. Foxe

    2014-01-01

    We often face the challenge of simultaneously attending to multiple non-contiguous regions of space. There is ongoing debate as to how spatial attention is divided under these situations. While for several years the predominant view was that humans could divide the attentional spotlight, several recent studies argue in favor of a unitary spotlight that rhythmically samples relevant locations. Here, this issue was addressed using high-density electrophysiology in concert with the multifocal m-...

  8. The cost of dividing the commons: Overlapping property systems in Tonle Sap, Cambodia

    OpenAIRE

    Thol Dina; Jin Sato

    2015-01-01

    This paper examines the political implications of dividing the commons through the case study of private fishing lots in the Tonle Sap Great Lake of Cambodia. The de facto private property in Tonle Sap lasted for over 100 years until the government abolished the system completely in March 2012. Unlike conventional studies of the commons which assume away the question of divisibility as too costly to be realistic, we argue that divided management occurs even when the cost is very high. This “c...

  9. Are egalitarians really vulnerable to the Levelling-Down Objection and the Divided World Example?

    OpenAIRE

    Subramanian, S

    2011-01-01

    This essay is a quick critique of one aspect of Derek Parfit’s criticism of Egalitarianism in his larger consideration of the claims of, and distinction between, Prioritarianism and Egalitarianism. It reviews issues relating to the ‘Levelling Down Objection’ and the ‘Divided World Example’. More specifically, it is argued that the Levelling Down Objection is a serious problem only for Pure Telic Egalitarianism, not for Pluralist Telic Egalitarianism; and thateven in a Divided World, one can ...

  10. Bridging the Digital Divide Creating Digital Dividend - The Investigation in Guizhou Province and the Analysis of GZNW

    OpenAIRE

    Jing, Linbo

    2007-01-01

    This article begins with attention to the digital divide. It gives a brief overview of the digital divide on a global basis and analyzes specific aspects of the digital divide in our country. It also introduces the informationization construction of Guizhou Province and points out problems with the digital divide in that province. Then it focuses on the practice of Guizhou Province to bridge the digital divide ---- the practice and experience of GZNW. The final section gives a series of polic...

  11. Development of a one-chip quantized Hall resistance voltage divider

    International Nuclear Information System (INIS)

    A resistive voltage divider, which is constructed from a binary segmented series array of quantized Hall resistance (QHR) bars fabricated on one chip, named the ‘QHR voltage divider’, has been developed. The QHR voltage divider does not, in principle, require time-consuming bootstrap self-calibration and will provide voltage ratios that are defined by fundamental physical constants with small uncertainties. To evaluate the performance of the QHR voltage divider, the dependence of the Hall resistances RH of all serial segments on the magnetic flux density was measured. The results of the RH measurement showed large and well-defined plateaus, and it was confirmed that the fabricated QHR divider in conjunction with a suitable voltage source would function as a voltage divider. From a preliminary test of the voltage ratios of the QHR voltage divider, deviations from nominal ratios were measured to be less than 1.4 × 10−6, and the expanded uncertainty of the measurement was estimated to be less than 4.1 × 10−6. (paper)

  12. Exergy loss analysis of heat transfer across the wall of the dividing-wall distillation column

    Energy Technology Data Exchange (ETDEWEB)

    Suphanit, B. [Department of Chemical Engineering, Faculty of Engineering, King Mongkut' s University of Technology Thonburi, Pracha Utit Road, Radburana, Bangkok 10140 (Thailand); Bischert, A. [Institut fuer Verfahrenstechnik Rheinisch-Westfaelische Technische Hochschule Aachen, Turmstrasse 46, 52056 Aachen (Germany); Narataruksa, P. [Department of Chemical Engineering, Faculty of Engineering, King Mongkut' s Institute of Technology North Bangkok, 1518 Pibulsongkram Road, Bangsue, Bangkok 10800 (Thailand)

    2007-11-15

    The dividing-wall distillation column is thermodynamically equivalent to the Petlyuk column on the condition that no heat transfer is allowed across the dividing wall. However, better energy efficiency of the column may be obtained if heat transfer occurs within a certain part of the wall. The effects of heat transfer across the dividing wall can be analyzed by using the column grand composite curve (CGCC). The heat transfer potential across the wall can be observed by looking at the CGCC of both column sections alongside the dividing wall. However, the possibility of whether heat should be added or rejected at any stage is not clearly known ahead of the CGCC. Consequently, in this work, the exergy analysis is applied to the dividing-wall column in order to determine whether heat should be added or rejected at any particular stage. Also, the minimum exergy loss value in the column is set as the criterion for determining the heat load targets at any stage. These load targets can then be plotted as a T-H profile similar to the CGCC. This methodology was reported to successfully apply to the column with multiple feeds and products. After having identified the locations and quantities of the feasible heat transfer across the dividing wall, the benefits are discussed via three case studies. (author)

  13. Exergy loss analysis of heat transfer across the wall of the dividing-wall distillation column

    International Nuclear Information System (INIS)

    The dividing-wall distillation column is thermodynamically equivalent to the Petlyuk column on the condition that no heat transfer is allowed across the dividing wall. However, better energy efficiency of the column may be obtained if heat transfer occurs within a certain part of the wall. The effects of heat transfer across the dividing wall can be analyzed by using the column grand composite curve (CGCC). The heat transfer potential across the wall can be observed by looking at the CGCC of both column sections alongside the dividing wall. However, the possibility of whether heat should be added or rejected at any stage is not clearly known ahead of the CGCC. Consequently, in this work, the exergy analysis is applied to the dividing-wall column in order to determine whether heat should be added or rejected at any particular stage. Also, the minimum exergy loss value in the column is set as the criterion for determining the heat load targets at any stage. These load targets can then be plotted as a T-H profile similar to the CGCC. This methodology was reported to successfully apply to the column with multiple feeds and products. After having identified the locations and quantities of the feasible heat transfer across the dividing wall, the benefits are discussed via three case studies

  14. Definig the Paradigm of ICTs and its dialogue with Global Digital Divide

    Directory of Open Access Journals (Sweden)

    Rafael Pinto da Silva

    2014-03-01

    Full Text Available The paper aims to present how the development of Information and Communication Technologies (ICTs and the advent of the informational economy have unleashed changes in economic relations that were not uniform across the globe and lead these phenomena to a direct dialogue with the effects of Global Digital Divide. In this regard, the essay has been divided into three parts. On the firs part, after a comparative analysis with other concepts, is presented the concept of Paradigm of ICTs. The second part explores the dialogue between the Paradigm of ICTs and Global Digital Divide and how it allowed a dynamic that activate economically certain places on the planet while leaving others on standby. The third part presents the numbers of the Global Digital Divide based on studies of international institutions to strengthen the argument empirically. The essay concludes that quantitative and qualitative inequality in accessibility, trade and development of ICTs field between the two extremes of the Global Digital Divide indicates the need to change the current standard that divides the world into regions with easy access and developers of advanced ICTs (turn on areas and regions with limited access, intensive manpower at low cost and absent in terms of research for the sector (standby areas.

  15. South Africa’s Socio-Techno divide: a critical discourse analysis of government speeches

    Directory of Open Access Journals (Sweden)

    W Chigona

    2010-08-01

    Full Text Available This paper aims at contributing to the debate about the digital divide. We first focus on what to us constitutes the root problem: the typical approaches to the development of people through and by the use of information and communication technologies (ICT. In contrast to governmental, political and technological attempts that focus almost exclusively on providing access to digital communication technologies, and expect “development” naturally to flow from that, we argue for a focus on “development” which is based on our notion of sustainable socio-economic development. We refer to “technocentric approaches” when the approaches propose and pursue technological interventions and show little regard for the actual needs of the people involved. At the other end of the scale, where the focus is on people and their developmental needs, we will speak of “sociocentric approaches”. This presents us with a different divide, which we will refer to as the “socio-techno divide”. We argue that it is this divide that has to be addressed – not the digital divide – and then present an analysis of the socio-techno divide. This analysis takes the form of two types of Critical Discourse Analysis (CDA, namely Foucauldian and Habermassian. The analysis of the South African government’s rhetoric illuminates the issues that need our attention and indicates an agenda for constructive engagement about the use of ICT for development in the Third and Fourth worlds.

  16. Water Wisdom: 23 Stand-Alone Activities on Water Supply and Water Conservation for High School Students. 2nd Edition.

    Science.gov (United States)

    Massachusetts State Water Resources Authority, Boston.

    This water conservation education program for high schools consists of both stand-alone activities and teacher support materials. Lessons are divided into six broad categories: (1) The Water Cycle; (2) Water and Society; (3) Keeping Water Pure; (4) Visualizing Volumes; (5) The Economics of Water Use; and (6) Domestic Water Conservation. The…

  17. Brain activity during divided and selective attention to auditory and visual sentence comprehension tasks

    Directory of Open Access Journals (Sweden)

    Mona Moisala

    2015-02-01

    Full Text Available Using functional magnetic resonance imaging, we measured brain activity of human participants while they performed a sentence congruence judgment task in either the visual or auditory modality separately, or in both modalities simultaneously. Significant performance decrements were observed when attention was divided between the two modalities compared with when one modality was selectively attended. Compared with selective attention (i.e., single tasking, divided attention (i.e., dual-tasking did not recruit additional cortical regions, but resulted in increased activity in medial and lateral frontal regions which were also activated by the component tasks when performed separately. Areas involved in semantic language processing were revealed predominantly in the left lateral prefrontal cortex by contrasting incongruent with congruent sentences. These areas also showed significant activity increases during divided attention in relation to selective attention. In the sensory cortices, no crossmodal inhibition was observed during divided attention when compared with selective attention to one modality. Our results suggest that the observed performance decrements during dual-tasking are due to interference of the two tasks because they utilize the same part of the cortex. Moreover, semantic dual-tasking did not appear to recruit additional brain areas in comparison with single tasking, and no crossmodal inhibition was observed during intermodal divided attention.

  18. Particle-in-cell simulations of electron beam control using an inductive current divider

    Science.gov (United States)

    Swanekamp, S. B.; Angus, J. R.; Cooperstein, G.; Ottinger, P. F.; Richardson, A. S.; Schumer, J. W.; Weber, B. V.

    2015-11-01

    Kinetic, time-dependent, electromagnetic, particle-in-cell simulations of the inductive current divider are presented. The inductive current divider is a passive method for controlling the trajectory of an intense, hollow electron beam using a vacuum structure that inductively splits the beam's return current. The current divider concept was proposed and studied theoretically in a previous publication [Swanekamp et al., Phys. Plasmas 22, 023107 (2015)]. A central post carries a portion of the return current (I1), while the outer conductor carries the remainder (I2) with the injected beam current given by Ib = I1 + I2. The simulations are in agreement with the theory which predicts that the total force on the beam trajectory is proportional to (I2-I1) and the force on the beam envelope is proportional to Ib. Independent control over both the current density and the beam angle at the target is possible by choosing the appropriate current-divider geometry. The root-mean-square (RMS) beam emittance (?RMS) varies as the beam propagates through the current divider to the target. For applications where control of the beam trajectory is desired and the current density at the target is similar to the current density at the entrance foil, there is a modest 20% increase in ?RMS at the target. For other applications where the beam is pinched to a current density ˜5 times larger at the target, ?RMS is 2-3 times larger at the target.

  19. Large-scale atomistic simulations of nanostructured materials based on divide-and-conquer density functional theory

    Directory of Open Access Journals (Sweden)

    Vashishta P.

    2011-05-01

    Full Text Available A linear-scaling algorithm based on a divide-and-conquer (DC scheme is designed to perform large-scale molecular-dynamics simulations, in which interatomic forces are computed quantum mechanically in the framework of the density functional theory (DFT. This scheme is applied to the thermite reaction at an Al/Fe2O3 interface. It is found that mass diffusion and reaction rate at the interface are enhanced by a concerted metal-oxygen flip mechanism. Preliminary simulations are carried out for an aluminum particle in water based on the conventional DFT, as a target system for large-scale DC-DFT simulations. A pair of Lewis acid and base sites on the aluminum surface preferentially catalyzes hydrogen production in a low activation-barrier mechanism found in the simulations

  20. Hydraulic loads analysis for divider plate and U-tube bundle of steam generator

    International Nuclear Information System (INIS)

    Hydraulic loads analysis during LOCA is the design basis for steam generator (SG) divider plate and U-tubes. The author introduces calculation models and the analysis for the maximum pressure drop of SG divider plate and the maximum horizontal hydraulic load of SG U-tubes for Qinshan-II Nuclear Power Plant during LOCA with ATHIS and FORCET computer codes from France and input data of Guangdong Nuclear Power Plant, and the comparison between these results and FRAMATOME's. The comparison show that both results meet better and the maximum pressure drop of SG divider plate is 8.0 MPa, the maximum horizontal hydraulic load of SG U-tubes is 1.164 x 106 N for the design of Qinshan-II Nuclear Power Plant

  1. The high voltage divider - a tool for comparison of measurement equipment in diagnostic radiology

    International Nuclear Information System (INIS)

    The high voltage divider (HVD) is designed for control and analysis of the characteristics of the X-ray generator. The low voltage analogous signals produced by the divider are proportional to the high voltage (kVp) applied to the x-ray tube by a ratio 1:1000 or 1:10000 and can be measured with external test devices like storage oscilloscope (or digital multimeter). The exposure duration and the wave form may be visualized, too. Apart of this invasive way the high voltage also may be measured non-invasively by means of appropriate devices as well as indirectly through calculations. Since the invasive method of measurement with the high voltage divider is distinguished by a high accuracy, it may be utilized as an effective tool for calibration of different devices and for comparison of the measurement methods. (authors)

  2. An InGaAs/InP 40 GHz CML static frequency divider

    Energy Technology Data Exchange (ETDEWEB)

    Su Yongbo; Jin Zhi; Cheng Wei; Ge Ji; Wang Xiantai; Chen Gaopeng; Liu Xinyu [Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029 (China); Xu Anhuai; Qi Ming, E-mail: jinzhi@ime.ac.cn [Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China)

    2011-03-15

    Static frequency dividers are widely used as a circuit performance benchmark or figure-of-merit indicator to gauge a particular device technology's ability to implement high speed digital and integrated high performance mixed-signal circuits. We report a 2 : 1 static frequency divider in InGaAs/InP heterojunction bipolar transistor technology. This is the first InP based digital integrated circuit ever reported on the mainland of China. The divider is implemented in differential current mode logic (CML) with 30 transistors. The circuit operated at a peak clock frequency of 40 GHz and dissipated 650 mW from a single -5 V supply. (semiconductor integrated circuits)

  3. Marker-independent Method for Isolating Slow-Dividing Cancer Stem Cells in Human Glioblastoma

    Directory of Open Access Journals (Sweden)

    Cristina Richichi

    2013-07-01

    Full Text Available Glioblastoma (GBM is a devastating brain tumor with a poor survival outcome. It is generated and propagated by a small subpopulation of rare and hierarchically organized cells that share stem-like features with normal stem cells but, however, appear dysregulated in terms of self-renewal and proliferation and aberrantly differentiate into cells forming the bulk of the disorganized cancer tissues. The complexity and heterogeneity of human GBMs underlie the lack of standardized and effective treatments. This study is based on the assumption that available markers defining cancer stem cells (CSCs in all GBMs are not conclusive and further work is required to identify the CSC. We implemented a method to isolate CSCs independently from cell surface markers: four patient-derived GBM neurospheres containing stem, progenitors, and differentiated cells were labeled with PKH-26 fluorescent dye that reliably selects for cells that divide at low rate. Through in vitro and in vivo assays, we investigated the growth and self-renewal properties of the two different compartments of high- and slow-dividing cells. Our data demonstrate that only slow-dividing cells retain the ability of a long-lasting self-renewal capacity after serial in vitro passaging, while high-dividing cells eventually exhaust. Moreover, orthotopic transplantation assay revealed that the incidence of tumors generated by the slow-dividing compartment is significantly higher in the four patient-derived GBM neurospheres analyzed. Importantly, slow-dividing cells feature a population made up of homogeneous stem cells that sustain tumor growth and therefore represent a viable target for GBM therapy development.

  4. Water heating system hydraulics. Hydraulik der Wasserheizung

    Energy Technology Data Exchange (ETDEWEB)

    Roos, H.

    1986-01-01

    Based on a minimum of fluid mechanics principles the manual facilitates access to the effects of hydraulic interventions or circuit manipulations in water heating systems. The book is a valuable vehicle for students and practical engineers. The detailed picture- and table-assisted discussion deals with the following subjects: Hydraulic resistors (tubes and pipes, networks, rheostats and single resistors), hydraulic connection methods (parallel and series connection), practical examples (switch-off of double and single tube heating systems, determination of hydraulic series cut-outs), straight-way valves and network (design and dimensioning), pumps as actuators, three-way valves and network (equivalent circuits, installation, working characteristics), interaction of locally separated pumps (example connection), hydraulic connections (characteristics of combined connections, example), overlaps of pumping action and gravitational effects, four-way mixers (purpose), overflow valves, jet pumps and computers. The final chapter is dedicated to the description of the Tichelmann circuit which is characterized by equal circuit lengths, equal pressure drops in straight tubes and reduced flow noises. With 183 figs., 12 tabs..

  5. Study of timing voltage divider system of PMT for neutron wall at CSR terminal

    International Nuclear Information System (INIS)

    On the outer-target experimental terminal in Heavy Ion Cooling Storage Ring at Lanzhou, an experimental setup for the study of RIB physics and the investigation of features of the asymmetric nuclear matter by means of RIB is highly required. The neutron detection wall is a main part of the detection equipment, in which there are 1000 photomultipliers serving as signal readout devices. The PMTs' voltage divider is studied. Both design parameters and the measured results show that the timing-type voltage divider is more suitable for detecting time signals. (authors)

  6. Divide-and-conquer: A proportional, minimal-envy cake-cutting algorithm

    OpenAIRE

    Brams, Steven J.; Jones, Michael A.; Klamler, Christian

    2010-01-01

    We analyze a class of proportional cake-cutting algorithms that use a minimal number of cuts (n-1 if there are n players) to divide a cake that the players value along one dimension. While these algorithms may not produce an envy-free or efficient allocation--as these terms are used in the fair-division literature--one, divide-and-conquer (D&C), minimizes the maximum number of players that any single player can envy. It works by asking n ? 2 players successively to place marks on a cake--va...

  7. Not at Home on the Range: Peer Production and the Urban/Rural Divide

    OpenAIRE

    Johnson, Isaac; Lin, Yilun; Jia-Jun Li, Toby; Hall, Andrew; Halfaker, Aaron; Schöning, Johannes; Hecht, Brent

    2016-01-01

    Wikipedia articles about places, OpenStreetMap features, and other forms of peer-produced content have become critical sources of geographic knowledge for humans and intelligent technologies. In this paper, we explore the effectiveness of the peer production model across the rural/urban divide, a divide that has been shown to be an important factor in many online social systems. We find that in both Wikipedia and OpenStreetMap, peer-produced content about rural areas is of systematically lowe...

  8. The use of the Internet in Morocco: Test for measuring the second digital divide

    OpenAIRE

    Samira Oukarfi

    2013-01-01

    This article proposes to prove economically the existence of a second level digital divide in Morocco. We have well designed and administered a questionnaire to approach 1030 persons living in the two largest cities of the Kingdom: Rabat and Casablanca. It seemed to us at the appropriate time to get down working in these big cities where normally there should not be any digital divide, at least the one of first degree, in order to detect inequalities in the use of the Internet. By the present...

  9. Has the Digital Divide Been Reversed? Evidence from Five EU Countries

    OpenAIRE

    PANTEA SMARANDA; MARTENS Bertin

    2013-01-01

    This paper examines whether there is a digital divide in the use of the internet in general and of specific websites (leisure, improving human capital and obtaining goods and services). It uses a unique dataset which covers the entire clickstream of almost 20,000 internet users in the five largest EU economies during 2011. Our main finding is that, for those who have access to the Internet, the income-based digital divide in internet use has been reversed. Low-income internet users spend more...

  10. E-LEARNING AND THE GLOBAL DIVIDE: The Challenges Facing Distance Education in Africa

    Directory of Open Access Journals (Sweden)

    Bamidele A. OJO

    2009-07-01

    Full Text Available This paper examines the question of distance education and its pivotal role in promoting social change and development in Africa. It also discussed within the context of the global digital divide and the ongoing need for collaborative effort at global education, the limitation imposed by the socio-economic and political environment on the continent. The paper in its findings conclude that the crisis within African societies constitutes a serious challenge to the implementation of and the effectiveness of distance education in Africa and therefore contributes to the widening of the digital divide rather than reducing it.

  11. Gradations in digital inclusion: children, young people and the digital divide

    OpenAIRE

    Livingstone, Sonia; Helsper, Ellen

    2007-01-01

    Little academic and policy attention has addressed the `digital divide' among children and young people. This article analyses findings from a national survey of UK 9—19-year-olds that reveal inequalities by age, gender and socioeconomic status in relation to their quality of access to and use of the internet. Since both the extent of use and the reasons for low- and non-use of the internet vary by age, a different explanation for the digital divide is required for children compared with adul...

  12. Ultralow phase noise microwave generation with an Er:fiber-based optical frequency divider

    CERN Document Server

    Quinlan, F; Kirchner, M S; Taylor, J A; Thorpe, M J; Lemke, N; Ludlow, A D; Jiang, Y; Oates, C W; Diddams, S A

    2011-01-01

    We present an optical frequency divider based on a 200 MHz repetition rate Er:fiber mode-locked laser that, when locked to a stable optical frequency reference, generates microwave signals with absolute phase noise that is equal to or better than cryogenic microwave oscillators. At 1 Hz offset from a 10 GHz carrier, the phase noise is below -100 dBc/Hz, limited by the optical reference. For offset frequencies > 10 kHz, the phase noise is shot noise limited at -145 dBc/Hz. An analysis of the contribution of the residual noise from the Er:fiber optical frequency divider is also presented.

  13. When Investors Enjoy Less Policy Risk: Divided Government, Economic Policy Change, and Stock Market Volatility in Germany, 1970-2005

    OpenAIRE

    Michael M. Bechtel; Roland Füss

    2008-01-01

    How does divided government affect the probability of economic policy change, and thus policy risk on financial markets? In contrast to the standard balancing model we argue that divided government, i.e., partisan conflict between the executive and the legislative branches, negatively affects the possibility of economic policy change. Using a simple spatial model we demonstrate that one should expect divided government to increase the probability of policy gridlock. Since divided government r...

  14. Uses of Information and Communication Technologies in Europe's Higher Education Institutions: From Digital Divides to Digital Trajectories

    OpenAIRE

    Adel Ben Youssef; Ludovic Ragni

    2008-01-01

    ABSTRACT This paper has two objectives, firstly, to identify the three basic levels of educational digital divides and to discuss them in the context of the European Union, and secondly, to develop an alternative hypothesis for educational digital trajectories instead of looking at educational divides.Section one identifies the three levels of digital divides. The first level of educational digital divide concerns differences in ICT equipment. We identify the sources and the mechanisms that h...

  15. Can't surf, won't surf: The digital divide in mental health

    OpenAIRE

    Ennis, Liam; Rose, Diana; Denis, Mike; Pandit, Ninjeri; Wykes, Til

    2012-01-01

    Background: New health information technology (HIT) increasingly plays a role in health care as technology becomes cheaper and more widespread. However, there is a danger that those who do not use or have access to technology will not benefit from HIT innovations, thus creating a “digital divide”.

  16. Speech Perception Engages a General Timer: Evidence from a Divided Attention Word Identification Task

    Science.gov (United States)

    Casini, Laurence; Burle, Boris; Nguyen, Noel

    2009-01-01

    Time is essential to speech. The duration of speech segments plays a critical role in the perceptual identification of these segments, and therefore in that of spoken words. Here, using a French word identification task, we show that vowels are perceived as shorter when attention is divided between two tasks, as compared to a single task control…

  17. Nuclear Technology. Course 27: Metrology. Module 27-2, Fixed Gages, Dividers, Calipers, and Micrometers.

    Science.gov (United States)

    Selleck, Ben; Espy, John

    This second in a series of eight modules for a course titled Metrology dscribes fixed gages, dividers, calipers, vernier and dial calipers, and micrometers. The module follows a typical format that includes the following sections: (l) introduction, (2) module prerequisites, (3) objectives, (4) notes to instructor/student, (5) subject matter, (6)…

  18. Crossing the Digital Divide Safely and Trustingly: How Ecologies of Learning Scaffold the Journey

    Science.gov (United States)

    Henning, Elizabeth; Van der Westhuizen, Duan

    2004-01-01

    The article addresses the issue of "learning to elearn" in borderless programs in a globalised learning landscape and the associated problems of scaffolding the journey across the digital divide. The authors argue that the assumption underlying such courses is that cross-cultural programs are viable because they are conceived and designed to be…

  19. Reassessing the Racial Divide in Support for Capital Punishment: The Continuing Significance of Race

    Science.gov (United States)

    Unnever, James D.; Cullen, Francis T.

    2007-01-01

    This project investigates the racial divide in support for capital punishment. The authors examine whether race has a direct effect on support for capital punishment and test whether the influence of race varies across class, being a native southerner, confidence in government officials, political orientation, and religious affiliation. Using data…

  20. Advanced AODV Protocol for Identify Victim Nodes Using Divide and Conquer Strategy-in MANET

    Directory of Open Access Journals (Sweden)

    S. Hemalatha

    2014-10-01

    Full Text Available Objective of this study is there are many protocols have been proposed in Ad-hoc network, but none of the protocol is working under the principle of handling and checking on packet delivery. We have developed a routing protocol called the Advanced Ad-hoc on demand Vector protocol. The working principle of this protocol is checking the packet delivery to the destination. If any one of the nodes in the route is not forwarding the packet, that corresponding node will be identified and redirect the packet to the new route. For doing this checking this protocol uses divide and conquer strategy. The number hop between the source to destination is divided into two halves and check whether the up to the middle node the packet are flowing in a proper order or not. Recursively doing the divide and conquer of the route path, can identify the node which is not forward the packet to the next node. The design of this protocol contains several stages from path discovery, packet transmits, apply divide and conquer strategy on route, identify the victim node which is not forward the packet, redirect the new path, alert all the nodes about the victim node. Finally performance graph has been given compared with AODV protocol.