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1

Water electrolysis: Divide and conquer  

Science.gov (United States)

The electrolysis of water provides a link between electrical energy and hydrogen, a high-energy-density fuel and a versatile energy carrier, but the process is expensive. Splitting the electrolysis reaction into two steps through an electrochemical 'buffer' offers a new way to think about improving the cost and efficiency of electrolysers.

Mallouk, Thomas E.

2013-05-01

2

Resistor holder  

Energy Technology Data Exchange (ETDEWEB)

A resistor device for use with electrostatic particle accelerators includes a resistor element positioned within a tubular housing having a fixed end cap at one end thereof and a movable end cap at the other end thereof. The tubular housing, fixed end cap, and movable end cap serve as an electromagnetic field for the resistor element. Conductive disks engage opposite ends of the resistor element and concentrically position the resistor element within the tubular housing. Helical springs engage the conductive disks and the end caps to yieldably support the movable end caps and resistor element for yieldable axial movement relative to the tubular housing. An annular conducting ring is secured to the tubular housing and is spaced radially from the movable end cap and cooperates with the latter to define an annular spark gap.

Broadhurst, John H. (Golden Valley, MN)

1989-01-01

3

The Vivitron resistors  

International Nuclear Information System (INIS)

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

1990-01-01

4

A Novel Voltage Divider Circuit  

Directory of Open Access Journals (Sweden)

Full Text Available A novel analog divider is described in this paper. The circuit enables the division of a dc voltage with another dc voltage. The constant of the division is dependent upon a third dc voltage and a pair of resistors. Employing a precision source for the third dc voltage and matched resistors, an acceptable level of accuracy can be obtained.

K. C. Selvam; S. Latha

2012-01-01

5

Bridging divides for water? Dialogue and access at the 5th World Water Forum  

Directory of Open Access Journals (Sweden)

Full Text Available The 5th World Water Forum was officially presented as a deliberative democracy where diverse stakeholders could gather to talk about water. However, the conference was marred by significant conflict, ranging from audience complaints to protests, and to alternative political declarations. This paper explores why a Forum designed to 'Bridge Divides for Water' (the official theme) was so contentious that participants were unable to reach any sort of consensus. I explore four hypothesised mechanisms by which the Forum itself counteracted the possibility of Bridging Divides and creating constructive dialogue. First, I argue that, because of cost, security and size, the Forum made many participants feel unable to fully access the Forum and share their opinions. Second, I suggest that the programmatic structure of the Forum promoted simplified ways of talking about water that made translation between perspectives difficult. Third, I contend that the physical space where Forum deliberations occurred institutionalised unequal social arrangements, making certain viewpoints more audible than others. Fourth, I demonstrate that the Turkish host government actively masked contestation to present a 'civilised' Forum to the world.

Nícola Ulibarrí

2011-01-01

6

Battery-Resistor Circuit  

Science.gov (United States)

This simulation demonstrates how a resistor works and the relationship between voltage, current and resistance. A change in temperature is also recorded with varying the parameters. The students will be shown the flow of electrons to make a fan spin. The more resistance that they put the slower the elctrons will move and vice versa. The students will also see the power generated by the battery.

Colorado, Phet A.

2010-07-28

7

Composition containing finely divided coal, water and at least one polyelectrolyte  

Energy Technology Data Exchange (ETDEWEB)

The invention concerns mixtures, mainly containing finely divided coal, water and polyelectrolyte. The mixture is characterized by containing 22-45% water by weight, and 0.01 - 5% polyelectrolyte with a mena molecular weight less than 5 times 10/sup 6/ - and which consists of water soluble, substituted polyethylene with sulphonate or hydrogensulphonate groups, which again are totally or partly in the form of salts, to the extent of a total sulphur content of 3 - 25% by weight, when the acidic groups are present as free acids.

Hansen, B.; Kelfve, S.; Mollberg, R.

1985-01-28

8

Process for separating crude oil from mixtures comprising finely divided inorganic solids, crude oil and water  

Energy Technology Data Exchange (ETDEWEB)

A process is claimed for separating crude oil from a mixture comprising crude oil, finely divided organic solids and water by contacting the mixture with a solvent and a solvent vapor stream in a first contacting zone to heat the mixture and produce a vaporous stream containing at least a major portion of the water and a crude oil laden solvent and inorganic solids mixture which is thereafter separated into a crude oil laden solvent stream and an inorganic solids stream with the inorganic solids stream being thereafter contacted with additional solvent to remove additional quantities of crude oil from the inorganic solids. Crude oil is recovered from a crude oil laden solvent stream.

Johnson, S.W.; Smith, R.H.

1984-07-17

9

Experimental and Analytic Studies of an RF Load Resistor  

Energy Technology Data Exchange (ETDEWEB)

The pulsed output of an 850-MHz klystron was directed into a load assembly containing a water-cooled, 50-ohm resistor. The load was systematically subjected to high peak-power pulses from the klystron. Several thin-film resistors were tested and exhibited various damage patterns for different combinations of peak microwave power (33 kW - 500 kW) and heat input. In order to better understand the phenomena observed, the electromagnetic field distribution inside the resistor housing was studied with WaveSim, a two-dimensional, finite-element scattering code. The conformal mesh of the program allowed accurate representations of the complex assembly geometry.

Borovina, D.L.; Humphries, S.; Gahl, J.M.; Rees, D.

1999-03-29

10

High voltage load resistor array  

Energy Technology Data Exchange (ETDEWEB)

A high voltage resistor comprising an array of a plurality of parallel electrically connected resistor elements each containing a resistive solution, attached at each end thereof to an end plate, and about the circumference of each of the end plates, a corona reduction ring. Each of the resistor elements comprises an insulating tube having an electrode inserted into each end thereof and held in position by one or more hose clamps about the outer periphery of the insulating tube. According to a preferred embodiment, the electrode is fabricated from stainless steel and has a mushroom shape at one end, that inserted into the tube, and a flat end for engagement with the end plates that provides connection of the resistor array and with a load.

Lehmann, Monty Ray (Smithfield, VA)

2005-01-18

11

For current viewing resistor loads  

Energy Technology Data Exchange (ETDEWEB)

The invention comprises a terminal unit for a flat cable comprising a BNC-PCB connector having a pin for electrically contacting one or more conducting elements of a flat cable, and a current viewing resistor having an opening through which the pin extends and having a resistor face that abuts a connector face of the BNC-PCB connector, wherein the device is a terminal unit for the flat cable.

Lyons, Gregory R. (Tijeras, NM); Hass, Jay B. (Lee' s Summit, MO)

2011-04-19

12

Impedance of Finite Length Resistor  

CERN Document Server

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

Krinsky, Samuel; Podobedov, Boris

2005-01-01

13

Dual design resistor for high voltage conditioning and transmission lines  

Energy Technology Data Exchange (ETDEWEB)

A dual resistor for eliminating the requirement for two different value resistors. The dual resistor includes a conditioning resistor at a high resistance value and a run resistor at a low resistance value. The run resistor can travel inside the conditioning resistor. The run resistor is capable of being advanced by a drive assembly until an electrical path is completed through the run resistor thereby shorting out the conditioning resistor and allowing the lower resistance run resistor to take over as the current carrier.

Siggins, Timothy Lynn (Newport News, VA); Murray, Charles W. (Hayes, VA); Walker, Richard L. (Norfolk, VA)

2007-01-23

14

Acceptance Criteria for Thick Film Resistors.  

Science.gov (United States)

The goal of this work was to determine the lot-to-lot consistency of thick film resistors. Also, incoming inspection procedures for inks were evaluated. The DuPont BIROX 1400 series resistors were found to be very consistent and reproducible. Recommendati...

T. V. Nordstrom

1980-01-01

15

Reliability growth of thin film resistors contact  

Directory of Open Access Journals (Sweden)

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

Lugin A. N.; Ozemsha M. M.

2010-01-01

16

Transient Temperature Rise in Film Resistors.  

Science.gov (United States)

Transient temperature distributions in film resistors are calculated for time intervals ranging from 10 nsec to 100 microsec. A one-dimensional model consisting of substrate, resistive film, and jacket is assumed. Peak temperatures are plotted for various...

H. Domingos

1974-01-01

17

Current controlled variable resistors through superconductors  

Energy Technology Data Exchange (ETDEWEB)

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.

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

1989-07-01

18

Acceptance criteria for thick film resistors  

Energy Technology Data Exchange (ETDEWEB)

The goal of this work was to determine the lot-to-lot consistency of thick film resistors. Also, incoming inspection procedures for inks were evaluated. The DuPont BIROX 1400 series resistors were found to be very consistent and reproducible. Recommendations are that material be bought on the standard DuPont certifications. A testing program of ink properties was recommended at Bendix to establish a material data base.

Nordstrom, T.V.

1980-08-01

19

Design of a Compact Dump Resistor System for LCD Magnet  

CERN Multimedia

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

Gaddi, A

2010-01-01

20

Device level electrothermal analysis of integrated resistors  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper presents the electrothermal simulation of integrated thin film resistors. Both the thermal and electrical problem is tackled by a semi-analytical method, without the need of generating an equivalent distributed network. As the electrical conductivity is temperature dependent, self-heating...

Vermeersch, Bjorn; De Mey, Gilbert

 
 
 
 
21

Arc suppression coil damped resistor thyristor protection device  

UK PubMed Central (United Kingdom)

A SCR protector with damping resistor for the electric arc eliminating coil is composed of two protecting SCR stages, 4 triggering current control resistors, a mutual current inductor, and a damping resistor. Their electric connection scheme is also disclosed. Its advantages are high response speed and high PIC ratio.

YANG XIAOQIANG WANG

22

Study of thin-film resistor resistance error  

Directory of Open Access Journals (Sweden)

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.

Spirin V. G.

2009-01-01

23

A Power Divider with Adjustable Dividing Ratio  

Science.gov (United States)

An unequal Wilkinson power divider with adjustable power dividing ratio is proposed. The proposed power divider consists of rectangular defected ground structure (DGS), isolated island in DGS, and varactor diodes. The impedance of the microstrip line greatly increases due to the DGS, and varies because of the varying capacitance of diodes. The measured unequal dividing ratios vary from 1.97-13.4 and 2.25-10.6 when 2- and 4-diodes are adopted.

Lim, Jongsik; Oh, Seongmin; Koo, Jae-Jin; Jeong, Yongchae; Ahn, Dal

24

FGMOS Based Voltage-Controlled Grounded Resistor  

Directory of Open Access Journals (Sweden)

Full Text Available This paper proposes a new floating gate MOSFET (FGMOS) based voltage-controlled grounded resistor. In the proposed circuit FGMOS operating in the ohmic region is linearized by another conventional MOSFET operating in the saturation region. The major advantages of FGMOS based voltage-controlled grounded resistor (FGVCGR) are simplicity, low total harmonic distortion (THD), and low power consumption. A simple application of this FGVCGR as a tunable high-pass filter is also suggested. The proposed circuits operate at the supply voltages of +/-0.75 V. The circuits are designed and simulated using SPICE in 0.25-µm CMOS technology. The simulation results of FGVCGR demonstrate a THD of 0.28% for the input signal 0.32 Vpp at 45 kHz, and a maximum power consumption of 254 µW.

R. Pandey; M. Gupta

2010-01-01

25

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.)

1980-01-01

26

Shunt switched resistor regulator with diode snubber  

Energy Technology Data Exchange (ETDEWEB)

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

Ekstrand, J.

1989-03-21

27

Studies of tantalum nitride thin film resistors  

International Nuclear Information System (INIS)

[en] 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)

1975-09-15

28

Scaling in small-world resistor networks  

International Nuclear Information System (INIS)

[en] We study the effective resistance of small-world resistor networks. Utilizing recent analytic results for the propagator of the Edwards-Wilkinson process on small-world networks, we obtain the asymptotic behavior of the disorder-averaged two-point resistance in the large system-size limit. We find that the small-world structure suppresses large network resistances: both the average resistance and its standard deviation approaches a finite value in the large system-size limit for any non-zero density of random links. We also consider a scenario where the link conductance decays as a power of the length of the random links, l-?. In this case we find that the average effective system resistance diverges for any non-zero value of ?

2006-02-13

29

Scaling in small-world resistor networks  

Energy Technology Data Exchange (ETDEWEB)

We study the effective resistance of small-world resistor networks. Utilizing recent analytic results for the propagator of the Edwards-Wilkinson process on small-world networks, we obtain the asymptotic behavior of the disorder-averaged two-point resistance in the large system-size limit. We find that the small-world structure suppresses large network resistances: both the average resistance and its standard deviation approaches a finite value in the large system-size limit for any non-zero density of random links. We also consider a scenario where the link conductance decays as a power of the length of the random links, l{sup -{alpha}}. In this case we find that the average effective system resistance diverges for any non-zero value of {alpha}.

Korniss, G. [Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY 12180-3590 (United States)]. E-mail: korniss@rpi.edu; Hastings, M.B. [Center for Non-linear Studies and Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Bassler, K.E. [Department of Physics, 617 Science and Research Blvd I, Univesity of Houston, Houston, TX 77204-5005 (United States); Berryman, M.J. [Centre for Biomedical Engineering (CBME) and School of Electrical and Electronic Engineering, The University of Adelaide, SA 5005 (Australia); Kozma, B. [Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY 12180-3590 (United States); Abbott, D. [Centre for Biomedical Engineering (CBME) and School of Electrical and Electronic Engineering, The University of Adelaide, SA 5005 (Australia)

2006-02-13

30

Scaling in Small-World Resistor Networks  

CERN Document Server

We study the effective resistance of small-world resistor networks. Utilizing recent analytic results for the propagator of the Edwards-Wilkinson process on small-world networks, we obtain the asymptotic behavior of the disorder-averaged two-point resistance in the large system-size limit. We find that the small-world structure suppresses large network resistances: both the average resistance and its standard deviation approaches a finite value in the large system-size limit for any non-zero density of random links. We also consider a scenario where the link conductance decays as a power of the length of the random links, $l^{-\\alpha}$. In this case we find that the average effective system resistance diverges for any non-zero value of $\\alpha$.

Korniss, G; Bassler, K E; Berryman, M J; Kozma, B; Abbott, D

2006-01-01

31

Structure and parameters of the thin-film rhenium resistors  

International Nuclear Information System (INIS)

[en] Presented are regimes of rhenium electron-beam evaporation to form thin-film rhenium resistors of hybrid integral schemes. Described is the change of rhenium films structure during heat treatment. To stabilize film electrophysical properties and prevent their irreversible structure changes it is desirable to anneal resistor at the temperature over 500 deg C after rhenium film deposition on to the substrate, and also to cover them with SiO protective coating. Presented are parameters of the thin-film rhenium resistors

1979-01-01

32

TALL CROP DIVIDER  

UK PubMed Central (United Kingdom)

A divider for attachment to the transverse member of a pushover bar assembly of a forage harvesting machine. The divider is a triangular structure having one leg alignable with the cropward side of the machine and a diagonal leg which is angled toward the center of the harvester. The legs are interconnected at their forward ends and form a divider point. The divider is pivotally mounted on the crossbar and is adjustable about a horizontal axis to optimum position. The one leg is resilient and is flexed against the pushover bar assembly to hold the parts tight. The structure of the one leg and rimforcing brace prevents hairpinning of the crops.

TUFTS GUY O; SCARNATO THOMAS J; PEACOCK PETER J

33

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

International Nuclear Information System (INIS)

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

1996-01-01

34

OBIC analysis of stressed, thermally-isolated polysilicon resistors  

Energy Technology Data Exchange (ETDEWEB)

High gain Optical Beam Induced Current (OBIC) imaging has been used for the first time to examine the internal structural effects of electrical stress on thermally-isolated polysilicon resistors. The resistors are examined over a wide range of current densities, producing Joule heating up to {approximately}1200{degrees}C. Throughout this current density range, the OBIC images indicate a clustering of dopant under dc stress and a more uniform distribution under ac conditions. The OBIC images also reveal areas that are precursors to catastrophic resistor failure. In addition to OBIC imaging, conventional electrical measurements were performed, examining the polysilicon resistance degradation and time-to-failure as a function of electrical stress. The electrical measurements show a monotonic increase in polysilicon resistor lifetime with frequency (up to 2 kHz) when subjected to a bipolar ac stress. The enhanced lifetime was observed even under high temperature (from Joule heating) stress conditions previously reported to be electromigration-free. The dopant redistribution indicated by the OBIC images is consistent with an electromigration stress experienced by the polysilicon resistors. The implications for thermally-isolated polysilicon resistor reliability are examined briefly.

Cole, E.I. Jr.; Peterson, K.A.; Campbell, A.N.; Snyder, E.S.; Pierce, D.G. [Sandia National Labs., Albuquerque, NM (United States); Suehle, J.S. [National Inst. of Standards and Technology, Gaithersburg, MD (United States); Chaparala, P. [Maryland Univ., College Park, MD (United States)

1994-12-31

35

A controllable resistor and its applications in pole-zero tracking frequency compensation methods for LDOs  

International Nuclear Information System (INIS)

[en] This paper presents a controllable resistor, which is formed by a MOS-resistor working in the deep triangle region and an auxiliary circuit. The auxiliary circuit can generate the gate-source voltage which is proportional to the output current of an low dropout regulator for the MOS-resistor. Thus, the equivalent output resistance of the MOS-resistor is inversely proportional to the output current, which is a suitable feature for pole-zero tracking frequency compensation methods. By switching the type of the MOS-resistor and current direction through the auxiliary circuit, the controllable resistor can be suitable for different applications. Three pole-zero tracking frequency compensation methods based on a single Miller capacitor with nulling resistor, unit-gain compensation cell and pseudo-ESR (equivalent serial resistor of load capacitor) power stage have been realized by this controllable resistor. Their advantages and limitations are discussed and verified by simulation results.

2009-01-01

36

Stabilization of synchronous generator by fuzzy logic controlled braking resistor  

Energy Technology Data Exchange (ETDEWEB)

In order to enhance the transient stability of synchronous generator, a fuzzy logic switching control scheme for the braking resistor is proposed. Following a fault, variable rotor speed of the generator is measured and the firing-angle of the thyristor switch in the braking resistor is determined from the crispy output of the fuzzy controller. By controlling the firing-angle of the thyristor, braking resistor can control the accelerating power in generator and thus improves the transient stability. Simulation results have been demonstrated for both balanced and unbalanced faults. It can be concluded from the simulation results that the proposed strategy provides a simple and effective method of stabilization of synchronous generator under transient conditions. (orig.)

Ali, M.H.; Funamoto, T.; Murata, T.; Tamura, J. [Kitami Inst. of Technology, Dept. of Electrical and Electronic Engineering, Hokkaido (Japan)

2000-08-01

37

Electrochemical Migration on Electronic Chip Resistors in Chloride Environments  

DEFF Research Database (Denmark)

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.

Minzari, Daniel; Jellesen, Morten Stendahl

2009-01-01

38

TI--CR--AL--O thin film resistors  

Energy Technology Data Exchange (ETDEWEB)

Thin films of Ti--Cr--Al--O are used as a resistor material. The films are rf sputter deposited from ceramic targets using a reactive working gas mixture of Ar and O.sub.2. Resistivity values from 10.sup.4 to 10.sup.10 Ohm-cm have been measured for Ti--Cr--Al--O film <1 .mu.m thick. The film resistivity can be discretely selected through control of the target composition and the deposition parameters. The application of Ti--Cr--Al--O as a thin film resistor has been found to be thermodynamically stable, unlike other metal-oxide films. The Ti--Cr--Al--O film can be used as a vertical or lateral resistor, for example, as a layer beneath a field emission cathode in a flat panel display; or used to control surface emissivity, for example, as a coating on an insulating material such as vertical wall supports in flat panel displays.

Jankowski, Alan F. (Livermore, CA); Schmid, Anthony P. (Solana Beach, CA)

2000-01-01

39

TI--CR--AL--O thin film resistors  

Science.gov (United States)

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

Jankowski, Alan F. (Livermore, CA); Schmid, Anthony P. (Solana Beach, CA)

2000-01-01

40

Manufacture of suitable ceramic resistors for the noise thermometry  

International Nuclear Information System (INIS)

Four different types of electronic conducting ceramics were investigated concerning their applicability for being used as a resistor in noise thermometry. A new preparation method where the electrodes are directly inserted into the green ceramic compact while being formed, is demonstrated in its usefulness. Modifying the composition of a Lanthanum-chromite based ceramic leads to a lower vaporization of the chromium compound. Manipulation of the nature and amount of dopants for ceramics containing polyvalent cations can lead to useful new resistor materials. (orig.).

1985-01-01

 
 
 
 
41

Resistor Loaded EBG Surfaces for Slot Antenna Design  

Directory of Open Access Journals (Sweden)

Full Text Available We present a resistor loaded EBG surface (REBG) for antenna design. Specifically, lumped resistors are embedded between periodic metal patches of mushroom like EBG structures. Surface wave propagation along the REBG surface is analyzed as a periodically loaded transmission line model and low transmission bandgap is identified and experimentally verified. The reflection properties of REBG surface to the incident electromagnetic waves are also studied. Slot antenna is placed within the REBG surface. The REBG surface is used to suppress surface waves across the antenna aperture, resulting in radiation performance improvement. Concurrently, the REBG surface can also absorb electromagnetic energy to reduce antenna radar cross section (RCS).

Shenyi Cao; Yunqi Fu

2013-01-01

42

High pressure steam stabilisation of tantalum thin film resistors  

Energy Technology Data Exchange (ETDEWEB)

Results are presented for tantalum thin film resistor stabilization in high pressure steam and oxygen. Steam oxidation accelerated resistance changes compared with air oxidation at 1 atm. The acceleration was equivalent to a 50/sup 0/C reduction in the required stabilization temperature, or to a sixfold reduction in the stabilization time required to produce an equivalent resistance change. Stabilization in saturated steam eventually caused complete resistor oxidation at the Ti/Pd/Au termination. The presence of palladium was necessary for this to occur. In unsaturated steam, this phenomenon did not occur. Instead, the titanium slowly oxidized and eventually resulted in a non-adherent termination contact metal.

Pitetti, R.C.; Keller, H.N.; Morabito, J.M.

1982-01-08

43

Monitoring the Digital Divide  

CERN Multimedia

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...

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

2003-01-01

44

Divided electrochemical cell assembly  

Energy Technology Data Exchange (ETDEWEB)

A divided electrochemical cell assembly comprises stacked bipolar substantially square parallel planar electrodes and membranes. The corners and edges of the electrodes with bordering insulative spacers in juxtaposition with the chamber walls define four electrolyte circulation manifolds. Anolyte and catholyte channeling means permit the separate introduction of anolyte and catholyte into two of the manifolds and the withdrawal of anolyte and catholyte separately from at least two other manifolds. The electrodes and membranes are separated from one another by the insulative spacers which are also channeling means disposed to provide electrolyte channels across the interfaces of adjacent electrodes and membranes.

King, Ch. J. H.

1985-02-19

45

Series fault limiting resistors for Atlas Marx modules  

Energy Technology Data Exchange (ETDEWEB)

The proposed Atlas design provides a current pulse to the experiment chamber from a set of 20, 3-Marx-unit-wide modules radially positioned around a retangular disk transmission-line system (total of 60 Marxes in parallel){sup 1}. The Atlas circuit is designed to be near-critically-damped network with a total erected capacitance of 200 {mu}F at 600 KV. The justification for the necessary circuit resistance in this approach is based on reliability, fault tolerance and operational maintenance{sup 1}. Also the use of high energy- density capacitors that have lower tolerance to voltage reversal is a primary reason for the damping provided by significant series resistance. To obtain the damping there are two system resistors in the Atlas design. One resistor is a shunt element designed to damp the resonance caused by the relatively high-Q disk transmission-line capacitance and the Marx bank inductance. The second, more significant resistor is a series, fault-current limiting element that also performs the necessary damping for voltage reversal at the bank capacitors. The Series resistor is the subject of this paper.

Thompson, C.; Bowman, D.; Gribble, R.F.; Griego, J.; Hinckley, W.B.; Kasik, R.J.; Reass, W.A.; Parsons, W.M. [Los Alamos National Lab., NM (United States); Cooper, R.A. [Maxwell Lab., San Diego, CA (United States)

1995-09-01

46

Air-cooled fast discharge resistors for ITER magnets  

International Nuclear Information System (INIS)

[en] 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.

2010-10-01

47

Implementing Ultra-high-Value Floating Tunable CMOS Resistors  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A compact high-value ?oating resistor utilising PMOS devices in the subthreshold region is introduced. A test chip has been fabricated in 0.18 um CMOS technology to verify the proposed concept. This technique has been applied to design a recon?gurable sixth-order very-low cutoff-frequency MOSFE...

Tajalli, Armin; Leblebici, Yusuf; Brauer, Elizabeth J.

48

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)

2003-01-01

49

Bridging the urological divide  

Directory of Open Access Journals (Sweden)

Full Text Available 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 literature review, this presentation defines the determinants of the disparity through deficiencies in human, material and financial resources, as is most prevalent in Developing countries. Solutions to ending health care disparities must take into account the existing development phase of Third World countries and thus determine whether the Developed countries should export a total service delivery system or seek primarily to advance the competence and skills of the existing Developing country resources. Collaboration in prostate cancer research has the greatest promise and sustainability of bridging this urological divide and is of mutual benefit to both entities.

Roberts Robin

2011-01-01

50

Vessel sealer and divider  

UK PubMed Central (United Kingdom)

An endoscopic bipolar forceps for sealing and dividing tissue, comprising: a housing having an elongated shaft attached thereto, the shaft defining a longitudinal axis the elongated shaft having opposing jaw members at a distal end thereof, the jaw members being movable relative to one another from a first position wherein the jaw members are disposed in spaced relation relative to one another to a second position wherein the jaw members cooperate to grasp tissue therebetween, each jaw member including an electrically conductive seating surface a drive rod assembly for imparting movement of the jaw members between the first and second positions: a handle assembly attached to the housing for actuating the drive rod assembly each jaw member adapted to connect to a source of electrosurgical energy such that the sealing surfaces of the jaw members are capable of conducting energy through tissue held therebetween to effect a tissue seal and characterised by the handle assembly including a four-bar mechanical linkage that includes a handle and a cam-like piston which cooperate to impart a uniform closure pressure against tissue grasped between the jaw members, whereby movement of the cam-like piston imparts movement to the drive rod assembly to impart movement of the jaw members between the first and second positions.

DYCUS SEAN T; BROWN DAX D; FARASCIONI DAVID; PRIMAVERY MICHAEL; FOWLER DAVID

51

Vessel sealer and divider  

UK PubMed Central (United Kingdom)

An endoscopic bipolar forceps for sealing and dividing tissue, comprising a housing having an elongated shaft attached thereto, the shaft defining a longitudinal axis the elongated shaft having opposing jaw members at a distal end thereof, the jaw members being movable relative to one another from a first position wherein the jaw members are disposed in spaced relation relative to one another to a second position wherein the jaw members cooperate to grasp tissue therebetween, each jaw member including an electrically conductive sealing surface a drive rod assembly for imparting movement of the jaw members between the first and second positions a handle assembly attached to the housing for actuating the drive rod assembly each jaw member adapted to connect to a source of electrosurgical energy such that the sealing surfaces of the jaw members are capable of conducting energy through tissue held therebetween to effect a tissue seal and characterised by the handle assembly including a four-bar mechanical linkage that includes a handle and a cam-like piston which cooperate to impart a uniform closure pressure against tissue grasped between the jaw members, whereby movement of the cam-like piston imparts movement to the drive rod assembly to impart movement of the jaw members between the first and second positions.

DYCUS SEAN T; BROWN DAX D; FARASCIONI DAVID; PRIMAVERY MICHAEL; FOWLER DAVID

52

Vessel sealer and divider  

UK PubMed Central (United Kingdom)

An electrosurgical instrument for performing at least one of sealing and dividing tissue includes a housing having a shaft attached thereto, the shaft defining a longitudinal axis. The electrosurgical instrument also includes a first jaw member movable relative to a second jaw member, the first jaw member attached to the shaft and being relatively movable from a first open position wherein the jaw members are disposed in spaces relation relative to one another to a second closed position wherein the jaw members cooperate to grasp tissue therebetween. The instrument also includes a drive rod assembly for imparting movement of the jaw members between the first and second positions and a rotating assembly attached to the housing for rotating the jaw members about the longitudinal axis. A knife assembly is also attached to the housing for separating tissue grasped between the jaw members and a handle assembly is attached to the housing for actuating the drive rod assembly. The instrument also includes first and second electrical leads which connect the jaw members to a source of electrical energy such that the jaw members are capable of conducting energy through tissue held therebetween. A handswitch is attached to the housing to allow a user to selectively energize the jaw members.

COUTURE GARY M; DYCUS SEAN T; JAMES JEREMY SCOTT; JOHNSON KRISTIN D; MOSES MICHAEL C; NGUYEN LAP P; SCHLECHTER DAVID A; SHIELDS CHELSEA; TETZLAFF PHILIP MARK; WARZECHA MICHAEL R

53

Vessel sealer and divider  

UK PubMed Central (United Kingdom)

An endoscopic bipolar forceps for sealing and dividing tissue, comprising: a housing having an elongated shaft attached thereto, the shaft defining a longitudinal axis the elongated shaft having opposing jaw members at a distal end thereof, the jaw members being movable relative to one another from a first position wherein the jaw members are disposed in spaced relation relative to one another to a second position wherein the jaw members cooperate to grasp tissue therebetween, each jaw member including an electrically conductive sealing surface a drive rod assembly for imparting movement of the jaw members between the first and second positions a handle assembly attached to the housing for actuating the drive rod assembly each jaw member adapted to connect to a source of electrosurgical energy such that the sealing surfaces of the jaw members are capable of conducting energy through tissue held therebetween to effect a tissue seal and characterised by the handle assembly including a four-bar mechanical linkage that includes a handle and a cam-like piston which cooperate to impart a uniform closure pressure against tissue grasped between the jaw members, whereby movement of the cam-like piston imparts movement to the drive rod assembly to impart movement of the jaw members between the first and second positions.

DYCUS SEAN T; BROWN DAX D; FARASCIONI DAVID; PRIMAVERY MICHAEL; FOWLER DAVID

54

Alternative power supply and dump resistor connections for similar, mutally coupled, superconducting coils  

International Nuclear Information System (INIS)

Alternative methods of connecting similar mutually coupled coils to their power supplies and dump resistors are investigated. The circuits are evaluated for both operating and fault conditions. The factors considered are the voltage to ground during a dump, short circuits, open circuits, quenches, and failure of the protection system to detect a quench. Of particular interest are the currents induced in coils that remain superconducting when one or more coils quench. The alternative connections include combined power supplies, individual dump resistors, combined resistors and series and parallel dump resistors. A new circuit that contains coupling resistors is proposed. The coupling resistors do not affect normal fast dumps but reduce the peak induced currents while also reducing the energy rating of the dump resistors. Another novel circuit, the series circuit with diodes, is discussed. The MFTF-B central-cell solenoids are used as an example.

1983-01-01

55

A random resistor network model of voltage trimming  

International Nuclear Information System (INIS)

[en] In industrial applications, the controlled adjustment (trimming) of resistive elements via the application of high voltage pulses is a promising technique, with several advantages with respect to more classical approaches such as the laser cutting method. The microscopic processes governing the response to high voltage pulses depend on the nature of the resistor and on the interaction with the local environment. Here we provide a theoretical statistical description of voltage discharge effects on disordered composites by considering random resistor network models with different properties and processes due to the voltage discharge. We compare standard percolation results with biased percolation effects and provide a tentative explanation of the different scenarios observed during trimming processes

2004-08-07

56

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

UK PubMed Central (United Kingdom)

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.

Lotkhov SV

2013-06-01

57

Dosimetry with a diamond operating as a resistor  

International Nuclear Information System (INIS)

[en] A very pure diamond with contacts of graphite has a linear current-voltage characteristic when subjected to irradiation. The resistivity is inversely proportional to the dose rate and the sensitivity is extremely high for ?- and X-rays and electron beams. It is concluded that diamond resistors are suitable for clinical radiation dosimetry. This conclusion is also based on earlier work in which diamonds were used as pinpoint counters. (author)

1981-01-01

58

Infinite Body Centered Cubic Network of Identical Resistors  

CERN Multimedia

We express the equivalent resistance between the origin and any other lattice site in an infinite Body Centered Cubic (BCC) network consisting of identical resistors each of resistance R rationally in terms of known values and . The equivalent resistance is then calculated. Finally, for large separation between the origin and the lattice site two asymptotic formulas for the resistance are presented and some numerical results with analysis are given.

Asad, J H

2013-01-01

59

Update on BAe resistor array design and development  

Science.gov (United States)

We describe the status of various aspects of BAe resistor array infra-red scene projector systems for hardware-in-the- loop testing. The aspects covered include subsystem development on current 512 X 512 systems; electronic data handling and driver systems, optical projection collimators, heatsink, cooling and environmental gas control systems. Design aspects are sketched for the progression from existing demonstrator arrays of up to 1024 X 1024 into complete systems.

Pritchard, Alan P.; Balmond, Mark D.; Brimecombe, Lucy A.; Lake, Stephen P.; Venables, Mark A.; Gough, David W.; Hebbron, Michael C.; Sturland, Ian M.

1999-07-01

60

Crossing the Digital Divide  

Energy Technology Data Exchange (ETDEWEB)

Nuclear utilities continue to upgrade aging instrumentation and control (I&C) systems with modern digital-based systems to address reliability and obsolescence concerns. In addition, the industry has demonstrated that these systems can be successfully developed and deployed even for highly safety-significant applications, such as reactor protection. However, three factors have retarded wide-scale implementation of digital technology for plant modernization and business innovation: *Large-scale digital upgrades entail considerable risk; *The upgrades are very costly and have not led to bottom-line business improvement, financial or otherwise; *Cyber Security concerns discourage wide-scale digital integration. A new national research program is under way that has been designed to address these industry concerns about expanding the use of digital technology. The Idaho National Laboratory (INL) has lead responsibility for the Advanced Instrumentation, Information, and Control Systems Technologies research pathway within the Light Water Reactor Sustainability (LWRS) Program. The LWRS Program is a research and development (R&D) program sponsored by the U.S. Department of Energy (DOE) and performed in close collaboration with industry R&D and improvement programs (as defined in INL’s FY2009–2013 Light Water Reactor Sustainability Research and Development Program Plan, INL/MIS08-14918). Its purpose is to provide the technical foundations for licensing and managing the long-term, safe, and economical operation of existing nuclear power plants. The DOE’s program focus is on longer-term and higher-risk/reward research that contributes to the national policy objectives of energy security and environmental security. The specific concern addressed by this program is that large-scale I&C obsolescence could become a life-limiting issue for the current nuclear operating fleet.

Ken Thomas

2011-11-01

 
 
 
 
61

High voltage, outdoor, air cooled, dynamic braking resistors and power distribution system incorporating the same  

Energy Technology Data Exchange (ETDEWEB)

An electrical resistor having first and second cylindrical resistance windings helically wound closely adjacent to one another about a common axis and wound in opposite directions about such axis. The helical windings of the resistor are connected in parallel and the resistor is provided with terminals for placing it in series with a circuit to provide a resistance in such circuit. The resistors are used in a power distribution system that includes a first system connected to a second system by a tie line. The resistors referred to as braking resistors are located adjacent to at least one of the power sources and are connected to the tie line through one or more circuit breakers.

Burke, P.E.

1989-09-26

62

Simple LabVIEW DC Circuit Simulation With Series Resistors: Overview  

Science.gov (United States)

This is a downloadable simple DC circuit simulation with 2 resistors in series for studying Ohm's Law. Users can adjust the voltage and the resistors while the current changes in real time, just like the real thing. Users are then asked whether the current increases or decreases as the ohms of the resistors increases. Includes instructions on how to measure DC / AC current. This free program requires Windows 9x, NT, or above. Note that this will NOT run on Mac OS.

2009-07-17

63

Measurements of fuse and resistor characteristics for multimegajoule capacitor bank application  

International Nuclear Information System (INIS)

[en] Experimental tests have been conducted on commercially available fuses and resistors under fast high-voltage pulsed (10-?s) conditions to determine their ability to protect capacitor bank components during faults. Currents in the resistors ranged from 20 to 40 kA per resistor. The experimental results for the fuses have been compared to the manufacturer's data for minimum melt and maximum let-through action integrals and to exploding bridge wire computer models

1987-01-01

64

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

1984-01-01

65

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

1984-06-12

66

Properties of diffused resistors in solar-grade semicrystalline silicon  

Energy Technology Data Exchange (ETDEWEB)

The transport properties of diffused p/sup +/-layers in n-type semicrystalline solar-grade silicon have been examined. It has been found that the grain boundary slightly increases the resistance of the majority carrier flow. A simple method is proposed to determine the average grain size, the barrier height and the effective trapping density at the grain boundary. Resistors made of these diffused layers show anomalous behaviour concerning their voltage and temperature dependence. This anomaly is caused by the soft I-V characteristics of the isolation p-n junction.

El-Emawy, A.; Zekry, A.; El-Koosy, M.; Fikry, H.

1988-07-01

67

Simple LabVIEW DC Circuit Simulation With Parallel Resistors: Overview  

Science.gov (United States)

This is a downloadable simple DC circuit simulation with 2 resistors in parallel with a third resistor. This is useful for studying Ohm's Law. Users can adjust the voltage and the resistors while the current changes in real time, just like the real thing. Users are then asked whether the current increases or decreases as the ohms of the resistors increases. Includes instructions on how to measure DC / AC current. This free program requires Windows 9x, NT, XP or later. Note that this will NOT run on Mac OS.

2009-08-21

68

An optimized resistor pattern for temperature gradient control in microfluidics  

Science.gov (United States)

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

Selva, Bertrand; Marchalot, Julien; Jullien, Marie-Caroline

2009-06-01

69

DNA repair mechanisms in dividing and non-dividing cells.  

UK PubMed Central (United Kingdom)

DNA damage created by endogenous or exogenous genotoxic agents can exist in multiple forms, and if allowed to persist, can promote genome instability and directly lead to various human diseases, particularly cancer, neurological abnormalities, immunodeficiency and premature aging. To avoid such deleterious outcomes, cells have evolved an array of DNA repair pathways, which carry out what is typically a multiple-step process to resolve specific DNA lesions and maintain genome integrity. To fully appreciate the biological contributions of the different DNA repair systems, one must keep in mind the cellular context within which they operate. For example, the human body is composed of non-dividing and dividing cell types, including, in the brain, neurons and glial cells. We describe herein the molecular mechanisms of the different DNA repair pathways, and review their roles in non-dividing and dividing cells, with an eye toward how these pathways may regulate the development of neurological disease.

Iyama T; Wilson DM 3rd

2013-08-01

70

A high T{sub c} superconducting loss-free resistor  

Energy Technology Data Exchange (ETDEWEB)

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

Jin, J. X.; Chen, J. Y.; Dou, S. X. [University of Wollongong, Wollongong, NSW (Australia). Center for Superconducting and Electronic Materials

1996-12-31

71

Affecting factors to the electrical properties of RuO2 thick-film resistors.  

Science.gov (United States)

In order to obtain knowledge to manufacture RuO2 thick-film resistors having resistance and the TCR controlled closely to the required value, RuO2 thick-film resistors were prepared with different variables, including various conductive particle sizes. gl...

O. Abe Y. Taketa

1991-01-01

72

A General Design Method for the Broadband Multi-Section Power Divider  

Energy Technology Data Exchange (ETDEWEB)

A novel multi-section power divider configuration is proposed to obtain wide-band frequency performance up to microwave frequency region. Design procedures for the proposed microwave broadband power divider are composed of a planar multi-section three-ports hybrid and a waveguide transformer design procedures. The multi-section power divider is based on design theory of the optimum quarter-wave transformer. Furthermore, in order to obtain the broadband isolation performance between the two adjacent output ports, the odd mode equivalent circuit should be matched by using the lossy element such as resistor. The derived design formula for calculating these odd mode-matching elements is based on the singly terminated filter design theory. The waveguide transformer section is designed to suppress the propagation of the higher order modes such as waveguide modes due to employing the metallic electric wall. Simulation and experiment show excellent performance of multi section power divider. (author). 7 refs., 11 figs., 1 tab.

Park, J.S.; Kim, H.S. [Soonchunhyang University, Asan (Korea); Lim, J.B. [Kookmin University, Seoul (Korea)

2002-02-01

73

Uncertainty quantification for electrical impedance tomography with resistor networks  

CERN Multimedia

We present a Bayesian statistical study of the numerical solution of the two dimensional electrical impedance tomography problem, with noisy measurements of the Dirichlet to Neumann (DtN) map. The inversion uses parametrizations of the conductivity on optimal grids that are computed as part of the problem. The grids are optimal in the sense that finite volume discretizations on them give spectrally accurate approximations of the DtN map. The approximations are DtN maps of special resistor networks, that are uniquely recoverable from the measurements. We present a statistical study of the noise effects on the inversion on optimal grids for both the linearized and the nonlinear inverse problem. The linearization is about a constant conductivity. We take three different parametrizations of the unknown conductivity perturbations, with the same number of degrees of freedom. We obtain that the parametrization induced by the inversion on optimal grids is the most efficient of the three, because it gives the smallest...

Borcea, Liliana; Mamonov, Alexander V

2011-01-01

74

Investigation of shunt resistor's connection for a DC Resistive SFCL  

International Nuclear Information System (INIS)

A DC-operating resistive-type superconducting fault current limiter for AC applications (in short a DC Resistive SFCL) is based on the synergistic use of the 'resistive' and the 'rectifier' fault current limiter concepts, and allows the superconductor to operate in nearly DC current conditions. This regime of operation drastically reduces AC losses thus opening new perspectives with regard to materials, architecture of the cable, lay out of windings and cryogenics. In this paper the concept of DC resistive SFCL is resumed and a case study about its possible application in the distribution electrical system is reported. Two possible connections of external shunt resistor in order to reduce the Joule heating during the limiting phase are analysed.

2010-06-01

75

Carbon Resistor Pressure Gauge Calibration at Low Stresses  

Energy Technology Data Exchange (ETDEWEB)

The 470 Ohm carbon resistor gauge has been used in the stress range up to approximately 4-5 GPa for highly heterogeneous materials and/or divergent flow experiments. The attractiveness of the gauge is due to its rugged nature, simple construction, low cost, reproducibility, and survivability in dynamic events. The associated drawbacks are a long time response to pressure equilibration and gauge resistance hysteresis. In the range below 0.4 GPa, the gauge calibration has been mainly extrapolated into this regime. Because of the need for calibration data within this low stress regime, calibration experiments were performed using a split-Hopkinson bar, drop tower apparatus, and a gas pressure chamber. Since the performance of the gauge at elevated temperatures is a concern, the change in resistance due to heating at atmospheric pressure was also investigated. Details of the various calibration arrangements and the results will be discussed and compared a calibration curve fit to previously published calibration data.

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

2001-06-22

76

Fabrication and electrical characterization of silicon nanowires based resistors  

International Nuclear Information System (INIS)

Silicon nanowires (SiNWs) are synthesized via the Vapor-Liquid-Solid (VLS) mechanism using gold (Au) as metal catalyst and silane (SiH4) 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.

2009-01-01

77

Fabrication and electrical characterization of silicon nanowires based resistors  

Energy Technology Data Exchange (ETDEWEB)

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.

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

78

A novel charge sensitive preamplifier without the feedback resistor  

International Nuclear Information System (INIS)

[en] 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

1992-01-01

79

A novel charge sensitive preamplifier without the feedback resistor  

Energy Technology Data Exchange (ETDEWEB)

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.

Bertuccio, G. (Politecnico di Milano, Milan (Italy). Dipt. di Elettronica e Informazione); Rehak, P.; Xi, D. (Brookhaven National Lab., Upton, NY (United States))

1992-01-01

80

A novel charge sensitive preamplifier without the feedback resistor  

Energy Technology Data Exchange (ETDEWEB)

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.

Bertuccio, G. [Politecnico di Milano, Milan (Italy). Dipt. di Elettronica e Informazione; Rehak, P.; Xi, D. [Brookhaven National Lab., Upton, NY (United States)

1992-07-01

 
 
 
 
81

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

International Nuclear Information System (INIS)

Full-size single-sided GaAs microstrip detectors with integrated coupling capacitors and bias resistors have been fabricated on 3'' substrate wafers. PECVD deposited SiO2 and SiO2/Si3N4 layers were used to provide coupling capacitances of 32.5 and 61.6 pF/cm, respectively. The resistors are made of sputtered CERMET using simple lift of technique. The sheet resistivity of 78 k?/#square# and the thermal coefficient of resistance of less than 4 x 10-3/ C satisfy the demands of small area biasing resistors, working on a wide temperature range. (orig.)

1998-04-11

82

Characteristics of burden resistors for high-precision DC current transducers  

CERN Document Server

The DC current transducer (DCCT) and accompanying A/D converter determine the precision of a power converter in accelerator operation. In the LHC context this precision approaches 10-6 (1 ppm). Inside the DCCT a burden resistor is used to convert the current to an output voltage. The performance of this resistor is crucial for the accuracy, temperature behaviour, settling time and longterm drift of the DCCT. This paper reports on evaluations, a new parameter called â??power coefficientâ? (PC) and test results from some different types of resistors available on the market.

Fernqvist, G; Hudson, G; Pickering, J

2007-01-01

83

Teaching general concepts about sensors and transfer functions with a voltage divider  

Directory of Open Access Journals (Sweden)

Full Text Available This work proposes the use of a simple voltage divider circuit composed by one potentiometer and one resistor to simulate the behavior of the electrical output signal of linear and nonlinear sensors. It is a low cost way to implement practical experiments in classroom and it also enables the analysis of interesting topics of electricity. This work induces naturally to a class guide where students can build and characterize a voltage divider to explore several concepts about sensors output signal. As the result of this teaching activity it is expected that students understand fundamentals of voltage divider, potentiometer operation, fundamental sensor characteristics, transfer function, and, besides, associate directly concepts of physics and mathematics with a practical approach.

João E. M. Perea Martins; Andrea C. G. Vianna

2011-01-01

84

Design and development of a resistive voltage divider for 3MeV DC accelerator  

International Nuclear Information System (INIS)

A resistive voltage divider has been designed and developed for the measurement of 3MV DC voltage of 3MeV, 30kW industrial accelerator to be commissioned at EBC Kharghar. A resistive divider does not require calibration, provided the leakage currents through the insulating medium are kept negligible, as compared to the HV arm current. The divider ratio is 3x107 and total resistance is 46G?. The divider is made in modular form with 4 modules, each of 750 kV and 810mm length and will be located inside the HV multiplier in the SF6 environment at 6 kg/cm2 pressure. Special corona shields surround the HV resistors for corona prevention so as to maintain the divider ratio. The equipotentials are matched to the HV multiplier to avoid capacitive loading of the divider. Divider modules have been assembled and tested in simulated conditions in open air. The salient features of design, fabrication details and present status of the divider will be presented in this paper. (author)

2005-01-01

85

Development of parallel wires type reference resistors as ac-dc transfer resistors; Kochoku transfer teikoki to shite no heikosengata kijun teikoki no kaihatsu  

Energy Technology Data Exchange (ETDEWEB)

In the case of a precision ac-resistance measurement, it is important to determine the change of resistance between ac and dc for the error factors refer to angular frequency {omega} because the resistance is normally calibrated at dc. The change of the resistance may be evaluated by the use of an ac-dc transfer resistor, of which frequency characteristics are calculable from the dimensions and the materials. This paper describes a parallel-wire-type ac-dc transfer resistor developed at the ETL using Ni-Cr alloy wire-resistor. The change of the resistance from dc up to 2 kHz was estimated to be less than 1 part in 10{sup -8}. 6 refs., 9 figs., 3 tabs.

Nishinaka, H.; Kinoshita, J. [Electric Laboratory, Tsukuba (Japan)

1995-08-20

86

Temperature sensor for electric food oven has positive temperature coefficient resistor wires separated by insulator  

UK PubMed Central (United Kingdom)

An electric food oven has a temperature sensor (10) with positive temperature coefficient resistor electric sensor wires (11, 12) that are de-coupled by an insulator (13). The insulator is positioned between the two wires.

GOETZ BERNHARD

87

Commercial carbon composition resistors as dynamic stress gauges in difficult environments  

Energy Technology Data Exchange (ETDEWEB)

Commercial carbon composition resistors have been used as gauges to make dynamic stress measurements in homogeneous and heterogeneous reactive and inert materials. Initial loading was provided by plane wave lenses or shaped charge jets. A series of gas gun and aquarium experiments has been conducted to characterize the behavior of the gauges. Calibrations up to about 14 GPa for nominal 470 {Omega} resistors and 17 GPa for nominal 4700 {Omega} resistors are presented. The accuracy of the carbon resistor gauges is limited by response time considerations when submicrosecond rise times are encountered, and there is hysteresis during release. The gauge-to-gauge reproducibility appears to be adequate, and they survive in situations where no other stress transducer has been successfully used, such as in reacting beds of large-particle gun propellants.

Ginsberg, M.J.; Asay, B.W. (Explosives Applications (M-8), Los Alamos National Laboratory, MS J960, Los Alamos, New Mexico (USA))

1991-09-01

88

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

Science.gov (United States)

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.

Wang, Xiao-Yuan; Andrew, L. Fitch; Herbert, H. C. Iu; Victor, Sreeram; Qi, Wei-Gui

2012-10-01

89

From devil to angel, transmission lines boost parallel computing of linear resistor networks  

CERN Multimedia

Transmission line is always big trouble for integrated circuits designers; however, it could be of great help to the parallel computing of extremely large linear resistor networks. In this paper, we introduce the virtual transmission method (VTM), which brings virtual transmission lines into linear resistor networks to achieve distributed and asynchronous parallel computing in the virtual time domain. Numerical experiments show that VTM could be efficiently running on the 2D or 3D microprocessor with arbitrary number of cores.

Wei, Fei

2009-01-01

90

Design and Fabrication of Carbon Nanotube Field-Emission Cathode with Coaxial Gate and Ballast Resistor.  

UK PubMed Central (United Kingdom)

A low density vertically aligned carbon nanotube-based field-emission cathode with a ballast resistor and coaxial gate is designed and fabricated. The ballast resistor can overcome the non-uniformity of the local field-enhancement factor at the emitter apex. The self-aligned fabrication process of the coaxial gate can avoid the effects of emitter tip misalignment and height non-uniformity.

Sun Y; Yeow JT; Jaffray DA

2013-05-01

91

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

International Nuclear Information System (INIS)

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

2001-01-01

92

An Investigation of the Relationship between Resistance and Thickness of Deposited Nickel Thin Film Resistors  

Directory of Open Access Journals (Sweden)

Full Text Available The main purpose of this study is finding the relationship between resistance and thickness of deposited Nickel Thin Film Resistors. It was found that the Sheet Resistance, Rs, is inversely proportional to the thickness of the film on the substrate. It was also observed that when the film thickness is greater than 50 nm, films behave like ordinary resistors. In other words in bulk, films obey Ohm’s law if other physical quantities remain constant.

Ericam R.R. Mucunguzi-Rugwebe; Michael Josiah Mangala

2013-01-01

93

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

International Nuclear Information System (INIS)

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 6Pascal), 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

2006-04-01

94

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

95

Affecting factors to the electrical properties of RuO2 thick-film resistors  

Energy Technology Data Exchange (ETDEWEB)

In order to obtain knowledge to manufacture RuO2 thick-film resistors having resistance and the TCR controlled closely to the required value, RuO2 thick-film resistors were prepared with different variables, including various conductive particle sizes. glass particle sizes, thermal expansion coefficients of the glass, mixing ratios of the conductive element and glass, and additives, et al. Then the relation between these factors and electrical properties of the thick-film resistors was studied in experiments. As a result. it was found that when a special glass is chosen, its R-TCR curve is unconditionally fixed regardless of various preparation factors, and the R-TCR curve can be moved only by changing the thermal expansion coefficient of the glass. Then, oxides of various elements were added to RuO2 thick-film resistors and the electrical properties of the resultant resistors were examined. It was clarified that almost all the oxides of transition metals, rare earths, and antimony used as additives can closely control the resistivity and TCR of the resistors to obtain a required value. In addition, it was clarified that the principle of superposition applies to the additives. 10 refs., 13 figs., 3 tabs.

Abe, O.; Taketa, Y. [Nihon University, Tokyo (Japan). College of Industrial Technology

1991-12-01

96

Noise properties of Pb/Cd-free thick film resistors  

Science.gov (United States)

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.

Witold Stadler, Adam; Kolek, Andrzej; Zawi?lak, Zbigniew; Mleczko, Krzysztof; Jakubowska, Ma?gorzata; Rafa? Kie?basi?ski, Konrad; M?o?niak, Anna

2010-07-01

97

Wealth and the marital divide.  

UK PubMed Central (United Kingdom)

Marriage patterns differ dramatically in the United States by race and education. The author identifies a novel explanation for these marital divides, namely, the important role of personal wealth in marriage entry. Using event-history models and data from the National Longitudinal Survey of Youth 1979 cohort, the author shows that wealth is an important predictor of first marriage and that differences in asset ownership by race and education help to explain a significant portion of the race and education gaps in first marriage. The article also tests possible explanations for why wealth plays an important role in first marriage entry.

Schneider D

2011-09-01

98

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

1982-08-31

99

SEU simulation and testing of resistor-hardened D-latches in the SA3300 microprocessor  

International Nuclear Information System (INIS)

[en] In this paper the SEU tolerance of the SA3300 microprocessor with feedback resistors is presented and compared to the SA3300 without feedback resistors and to the commercial version (NS32016). Upset threshold at room temperature increased from 23 MeV-cm2/mg and 180 MeV-cm2/mg with feedback resistors of 50 k? and 160 k?, respectively. The performance goal of 10 MHz over the full temperature range of -55 degrees C to +125 degrees C is exceeded for feedback resistors of 160 k? and less. Error rate calculations for this design predict that the error rate is less than once every 100 years when 50 k? feedback resistors are used in the D-latch design. Analysis of the SEU response using a lumped-parameter circuit simulator imply a charge collection depth of 4.5 ?m. This is much deeper than the authors would expect for prompt collection in the epi and funnel regions and has been explained in terms of diffusion current in the heavily doped substrate

1991-01-01

100

Microstructure and Phase Development of Buried Resistors in Low Temperature Co-Fired Ceramic  

Energy Technology Data Exchange (ETDEWEB)

Embedded resistor circuits have been generated with the use of a Micropen system Ag conductor paste (DuPont 6142D), a new experimental resistor ink from DuPont (E84005-140), and Low Temperature Co-fired Ceramic (LTCC) green tape (DuPont A951). Sample circuits were processed under varying peak temperature ranges (835 C-875 C) and peak soak times (10 min-720 min). Resistors were characterized by SEM, TEM, EDS, and high-temperature XRD. Results indicate that devitrification of resistor glass phase to Celcian, Hexacelcian, and a Zinc-silicate phase occurred in the firing ranges used (835-875 C) but kinetics of divitrification vary substantially over this temperature range. The resistor material appears structurally and chemically compatible with the LTCC. RuO{sub 2} grains do not significantly react with the devitrifying matrix material during processing. RuO{sub 2} grains coarsen significantly with extended time and temperature and the electrical properties appear to be strongly affected by the change in RuO{sub 2} grain size.

DIMOS,DUANE B.; KOTULA,PAUL G.; RODRIGUEZ,MARK A.; YANG,PIN

1999-11-30

 
 
 
 
101

Evidence for divided automatic attention  

Directory of Open Access Journals (Sweden)

Full Text Available A long-standing debate in the literature is whether attention can form two or more independent spatial foci in addition to the well-known unique spatial focus. There is evidence that voluntary visual attention divides in space. The possibility that this also occurs for automatic visual attention was investigated here. Thirty-six female volunteers were tested. In each trial, a prime stimulus was presented in the left or right visual hemifield. This stimulus was characterized by the blinking of a superior, middle or inferior ring, the blinking of all these rings, or the blinking of the superior and inferior rings. A target stimulus to which the volunteer should respond with the same side hand or a target stimulus to which she should not respond was presented 100 ms later in a primed location, a location between two primed locations or a location in the contralateral hemifield. Reaction time to the positive target stimulus in a primed location was consistently shorter than reaction time in the horizontally corresponding contralateral location. This attentional effect was significantly smaller or absent when the positive target stimulus appeared in the middle location after the double prime stimulus. These results suggest that automatic visual attention can focus on two separate locations simultaneously, to some extent sparing the region in between.

P.S. Silva; L.E. Ribeiro-do-Valle

2008-01-01

102

A wideband metamaterial absorber based on a magnetic resonator loaded with lumped resistors  

Science.gov (United States)

A wideband metamaterial absorber (MA) based on a magnetic resonator loaded with lumped resistors is presented. It is composed of a one-dimensional periodic array of double U-shaped structured magnetic resonators loaded with lumped resistors, a dielectric substrate, and a metal plate. We simulated, fabricated, measured, and analyzed the MA. The experimental results show that the reflectance (S11) is below -10 dB at normal incidence in the frequency range of 7.7 GHz-18 GHz, and the peak value is about -20 dB. Simulated power loss density distributions indicate that wideband absorption of the MA is mainly attributable to the lumped resistors in the magnetic resonator. Further investigations indicate that the distance between two unit cells along the magnetic field direction significantly influences the performance of the MA.

Cheng, Yong-Zhi; Gong, Rong-Zhou; Nie, Yan; Wang, Xian

2012-12-01

103

A fully integrated, monolithic, cryogenic charge sensitive preamplifier using N-channel JFETs and polysilicon resistors  

International Nuclear Information System (INIS)

[en] In this paper, an integrated charge preamplifier to be used with small (10--30 mm2) Si(Li) and Ge(Li) X-ray detectors is described. The preamplifier is designed to operate at cryogenic temperatures (?100 K to 160 K) for the best performance. An N-channel JFET process technology for integrated charge sensitive preamplifiers has been developed. The process integrates multiple pinch-off voltage JFETs fabricated in an n-type epitaxial layer on a low resistivity p-type substrate. The process also incorporates polysilicon resistors integrated on the same die as the JFETs. The optimized polysilicon resistors exhibit 1/f noise nearly as good as metal film resistors at the same current. Results for integrated amplifier are discussed

1993-11-06

104

Transducer for a discrete helium level indicator on the base of carbon resistor  

International Nuclear Information System (INIS)

An indicator of a liquid helium level is described. The transducer of the indicator is made of a carbon resistor used usually as a temperature monitor. The influence of the transducer manufacturing process and measurement conditions on sensitivity and heat release in liquid helium is investigated. The resistors with the 0.1-1 kOhm resistance at the 300 K temperature and the moninal power of 0.125 and 0.25 W are used. The best results are obtained with the 1 kOhm and 0.25 W resistors. The change in signal taken from the transducer, is upto 100% for the vapor- liquid boundary transition at heat release in liquid, Wsub(l)=49 mW and upto 60% at Wsub(l)=1.6 mW. The accuracy of the level determination is

1984-01-01

105

Process for producing Ti-Cr-Al-O thin film resistors  

Energy Technology Data Exchange (ETDEWEB)

Thin films of Ti-Cr-Al-O are used as a resistor material. The films are rf sputter deposited from ceramic targets using a reactive working gas mixture of Ar and O.sub.2. Resistivity values from 10.sup.4 to 10.sup.10 Ohm-cm have been measured for Ti-Cr-Al-O film <1 .mu.m thick. The film resistivity can be discretely selected through control of the target composition and the deposition parameters. The application of Ti-Cr-Al-O as a thin film resistor has been found to be thermodynamically stable, unlike other metal-oxide films. The Ti-Cr-Al-O film can be used as a vertical or lateral resistor, for example, as a layer beneath a field emission cathode in a flat panel display; or used to control surface emissivity, for example, as a coating on an insulating material such as vertical wall supports in flat panel displays.

Jankowski, Alan F. (Livermore, CA); Schmid, Anthony P. (Solana Beach, CA)

2001-01-01

106

A Biased Resistor Network Model for Electromigration Phenomena in Metallic Lines  

CERN Document Server

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...

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

2004-01-01

107

Crossroads - Bridging the Digital Divide  

Directory of Open Access Journals (Sweden)

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.

David Cobb

2005-01-01

108

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)

1982-01-01

109

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

International Nuclear Information System (INIS)

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

1983-01-01

110

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

Energy Technology Data Exchange (ETDEWEB)

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

Raymond, Leonard S. (Tucson, AZ)

1983-01-01

111

The Linewidth Dependence of GMR Properties in Patterned Spin Valve Resistors  

International Nuclear Information System (INIS)

The spin-valve structures with the configuration of NiFeCo(42.5A)/CoFe(15A)/ Cu(25A)/CoFe(42.5A)/CrPtMn(300A) were fabricated by RF diode sputtering. After a annealing process, the sheet spin-valve thin films were photolithographically patterned into serpentine resistors with different linewidths. The effect of linewidths on the magnetic properties and GMR ratio of patterned spin-valve resistors were studied. It was found GMR decrease with decreasing linewidths due to size effect and the effective anisotropy field Hk and the bias field field Hb are both inversely proportional to linewidths.

2011-01-01

112

Elimination of closing resistors in 500 kV transmission lines; Eliminacao de resistores de fechamento em disjuntores de linhas de transmissao de 500 kV  

Energy Technology Data Exchange (ETDEWEB)

The main objective of this study is to present which studies should be performed in order to analyse the possibility of eliminating closing resistors in circuit breaker of 500 kV transmission lines when zinc oxide lighting arresters are used in the terminal of such transmission lines. A study performed using the electromagnet transients program (EMTP) is presented. Results are also presented 6 figs., 10 refs.

Carvalho, F.M. Salgado [FURNAS Centrais Eletricas S.A., Rio de Janeiro, RJ (Brazil); Vaisman, Roberto [Centro de Pesquisas em Energia Eletrica (CEPEL), Rio de Janeiro, RJ (Brazil)

1995-12-31

113

Chaos, brain and divided consciousness.  

UK PubMed Central (United Kingdom)

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

Bob P

2007-01-01

114

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

1997-01-01

115

Abrasion resistance of various thin film coatings on thick film resistor materials  

International Nuclear Information System (INIS)

The lifetime of resistive heaters in thermal printing heads is mainly determined by the continuous abrasion due to the mechanical contact with the sliding paper. The thick film resistor materials used are not specifically developed for abrasion resistance; therefore protective coatings were applied to the resistor surface in order to enhance the long-term performance of the printing head. The optimum abrasion resistance was achieved with a diamond-like carbon coating but, in this paper, standard coatings are also investigated, since they are interesting from an economical point of view. On two different thick film resistor materials (Tanaka and DuPont), sputtered thin films of Al2O3, SiOx and Si3N4 as well as coatings of SiO2 (substrate temperatures 250 and 350degC) obtained by plasma-enhanced chemical vapour deposition were produced (d = 2 ?m) and subjected to the polishing test described elsewhere. In comparison with the uncoated samples the abrasion of the resistors is decelerated by all coatings but to different extents. The criterion of minimum thickness decrease after 20 min of polishing revealed the chemically vapour-deposited coatings of SiO2 as the best in the present test. (orig.).

1991-01-01

116

Transistor high voltage divider for photomultipliers  

International Nuclear Information System (INIS)

[en] A new type of a simple high voltage divider for photomultiplier tubes has been developed and tested. The current of the divider is defined by current without counting rate (300 mkA) and average PM current. Photomultiplier with the new divider can work at high counting rate with constant gain. (author)

1997-01-01

117

Measurements of fuse and resistor characteristics for multi-megajoule capacitor bank application  

International Nuclear Information System (INIS)

[en] Experimental tests have been conducted on commercially available fuses and resistors under fast high voltage pulsed (10 ?sec) conditions to determine their ability to protect capacitor bank components during faults. NRL's Modified Betatron Accelerator uses two multi-megajoule capacitor banks to power the toroidal and betatron magnetic field coils. The expensive high energy density capacitors in these banks must be protected from excessive peak current, voltage reversal, or charging beyond their electrical ratings in the occurrence of a fault. Adequate protection can be obtained with fuses and resistors in series with each parallel connected capacitor. The fuses must open reliably and hold off high voltage D.C. (10 - 20 kV), and the resistors must conduct high current and di/dt without failing from energy deposition or magnetic forces. The performance of the commercial fuses is well documented at low AC frequencies and currents (60 Hz/100 A) but data was not previously available for the fast high current pulsed conditions that prevail under actual fault conditions. A 20 kV 200 kJ, low inductance capacitor bank and ignitron switch were used to conduct the experiments. Peak currents in the fuses were approximately 170 kA at t - 6.5 ?s. The final fuse hold-off voltage exceeded 8 kV. Currents in the resistors ranged from - 20 - 40 kA per resistor. The experimental results have been compared to the manufacturers data from minimum melt and maximum let-through and to exploding bridge wire computer models

1986-01-01

118

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

CERN Multimedia

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....

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

2013-01-01

119

Replacement divider plate performance under LOCA loading  

Energy Technology Data Exchange (ETDEWEB)

A primary divider plate in a nuclear steam generator is required to perform its partitioning function with a minimum of cross leakage, without degradation in operating performance and without loss of structural integrity resulting from normal and accident loading. The design of the replacement divider plate for normal operating conditions is discussed in some detail in reference 1 and 2. This paper describes the structural response of the replacement divider plate to the severe loading resulting from a burst primary pipe. The loads for which the divider plate structural performance must be evaluated are mild to severe differential pressure transients resulting from several postulated sizes and types of pipe break scenarios. In the unlikely event of a severe Loss of Coolant Accident (LOCA) the divider plate or parts thereof must not exit the steam generator nor completely block the outlet nozzle. For the milder LOCA loads, the integrity of the divider plate and seat bars must be maintained. Analysis for the milder LOCA loads was carried out employing a conservative approach which ignores the actual interaction between the structure and the primary fluid. For these load cases it was shown that the divider plate does not become disengaged from the seat bars. For the more severe pipe breaks, the thermal-hydraulic analysis was coupled iteratively with the structural analysis, thereby taking into account divider plate deformation, in order to obtain a better prediction of the behaviour of the divider plate. In this manner substantial reduction in divider plate response to the more severe LOCA loading was achieved. It has been shown that, for the case of a postulated large LOCA (100% reactor inlet header), the disengagement of the divider plate from the seat bars resulted in an opening smaller than 1% of the divider plate area. (author)

Huynk, H.M. [Quebec Hydro, Montreal, PQ (Canada); MClellan, G.H.; Schneider, W.G. [Babcock and Wilcox, Cambridge, ON (Canada)

1997-07-01

120

Frequencies for Pain Reliever Questionnaire Items: Divided ...  

Science.gov (United States)

... Frequencies for Pain Reliever Questionnaire Items: Divided Attention – This product treats minor aches and pains associated with headache. ... More results from www.fda.gov/drugs/developmentapprovalprocess/developmentresources

 
 
 
 
121

A modified approach to transient stability enhancement with fast valving and braking resistor applications  

Energy Technology Data Exchange (ETDEWEB)

Fast valving and braking resistor are two important members of the family of the discrete supplementary controllers (DISCOS). Both of these are very effective and economic means of transient stability enhancement under extreme contingencies. Being stationed at the similar end of a power system the two schemes carry a very good potential of an effective coordination. Such a coordinated control is helpful not only in obtaining an improved gain in stability, but also in overcoming the limitations and avoiding excessive duty on the part of an individual controller. In this work, a detailed study has been carried out to evaluate the scope and limitations of fast valving and dynamic braking resistor controls in enhancing the transient stability of power systems. Improvements have been suggested over the conventional schemes of control so as to improve their adaptability under different conditions of fault and loading or with different types of generating units. (author)

Patel, Ramnarayan [Indian Institute of Technology, Roorkee, Uttaranchal (India). Department of Electrical Engineering; Bhatti, T.S.; Kothari, D.P. [Indian Institute of Technology, Delhi, New Delhi (India). Centre for Energy Studies

2006-12-15

122

A minimum-time based fuzzy logic dynamic braking resistor control for sub-synchronous resonance  

Energy Technology Data Exchange (ETDEWEB)

Dynamically switched resistor banks connected to the generator transformer bus are known to improve transient stability of the power system. In this article, a braking resistor control strategy designed through fuzzy logic control theory has been proposed to damp the slowly growing sub-synchronous resonant (SSR) frequency oscillations of a power system. The proposed control has been tested on the IEEE second benchmark model for SSR studies. A fuzzy logic controller designed through a classical minimum-time strategy was compared with a general fuzzy strategy employing generator speed variation and acceleration as input to the controller. It was observed that the proposed minimum-time based fuzzy controller provides better damping control; and it is computationally very efficient. (author)

Rahim, A.H.M.A. [University of Petroleum and Minerals, Dhahran (Saudi Arabia). Dept. of Electrical Engineering

2004-03-01

123

Application of the lattice Green's function for calculating the resistance of an infinite grid of resistors  

CERN Multimedia

We calculate the resistance between two arbitrary grid points of several infinite lattice structures of resistors by using the lattice Green's function defined on the lattice. The resistance for $d$ dimensional hypercubic, rectangular, triangular and honeycomb lattice of resistors are discussed in details. For large separation between the points where the current enters and exits we obtain the asymptotic form of the resistance in case of square lattice and the finite and exact value of the resistance for simple cubic lattice. We point out the relation between the resistance of the lattice and the van Hove singularity of the tight-binding Hamiltonian defined on the lattice. Our general method can be applied in a straightforward manner for other type of lattice structures and can be useful didactically for introducing many concepts used in solid state physics.

Cserti, J

1999-01-01

124

Cooper Pair Transport in a Resistor-Biased Josephson Junction Array  

CERN Document Server

The dc transport properties of long arrays of small Al Josephson junctions, biased through on-chip Cr resistors, are studied. The IV-characteristics show a large Coulomb threshold for current as well as negative-slope regions indicating the regime of autonomous Bloch oscillations up to rather high frequencies of f = I/2e ~1 GHz, comparable to those reported by other groups for single junctions. On the other hand, a small depth of the back-bending implies a low duty cycle and a broad spectrum of the oscillations, which we attribute to the insufficiently high impedance of the bias resistors. A self-sustained switching process at a small bias current is used to study the statistics of the switching voltages and to determine the effective Bloch capacitance which was found to considerably exceed the geometric junction capacitance.

Lotkhov, S V; Zorin, A B; Lotkhov, Sergey V.; Krupenin, Vladimir A.; Zorin, Alexander B.

2006-01-01

125

Carbon Resistor Pressure Gauge Calibration at Stresses Up to 1 GPa  

Energy Technology Data Exchange (ETDEWEB)

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.

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

2002-03-05

126

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)

1985-01-01

127

Effect of composition and microstructure on the transport and piezoresistive properties of thick-film resistors  

International Nuclear Information System (INIS)

[en] The piezoresitive effect of thick-film resistors has found widespread application in pressure and force sensors due to their strain-resistivity, stability and low-cost. The main material requirements for these applications are a high piezoresistive response, low noise and low temperature dependence. However, many useful elastic substrate materials are degraded at the strand thick-film processing temperature of 850 oC, and therefore require a lower one. This is achieved by engineering the glass composition. Here we discuss how the composition and microstructure affect the electronic properties of thick-film resistors with both high and low processing temperatures. Depending on the firing temperature, we find percolative samples a lowering of the RuO2 concentration generally leads to a logarithmic increase of the piezoresistive response, which poses serious limitations regarding the associated power-low increase of noise. (author)

2004-01-01

128

The Linewidth Dependence of GMR Properties in Patterned Spin Valve Resistors  

Energy Technology Data Exchange (ETDEWEB)

The spin-valve structures with the configuration of NiFeCo(42.5A)/CoFe(15A)/ Cu(25A)/CoFe(42.5A)/CrPtMn(300A) were fabricated by RF diode sputtering. After a annealing process, the sheet spin-valve thin films were photolithographically patterned into serpentine resistors with different linewidths. The effect of linewidths on the magnetic properties and GMR ratio of patterned spin-valve resistors were studied. It was found GMR decrease with decreasing linewidths due to size effect and the effective anisotropy field H{sub k} and the bias field field H{sub b} are both inversely proportional to linewidths.

Sun Yucheng; Qian Zhenghong; Bai Ru [Center For Integrated Spintronic Devices (CISD), Hangzhou Dianzi University, Hangzhou, ZJ 310018 (China); Zhu Jianguo, E-mail: zqian@hdu.edu.cn [College of Material Sciences and Engineering, Sichuan University, Chengdu, SC 610064 (China)

2011-01-01

129

Current flow in random resistor networks: The role of percolation in weak and strong disorder  

Science.gov (United States)

We study the current flow paths between two edges in a random resistor network on a L×L square lattice. Each resistor has resistance eax , where x is a uniformly distributed random variable and a controls the broadness of the distribution. We find that: (a) The scaled variable u?L/ a? , where ? is the percolation connectedness exponent, fully determines the distribution of the current path length l for all values of u . For u?1 , the behavior corresponds to the weak disorder limit and l scales as l˜L , while for u?1 , the behavior corresponds to the strong disorder limit with l˜ L dopt , where dopt =1.22±0.01 is the optimal path exponent. (b) In the weak disorder regime, there is a length scale ?˜ a? , below which strong disorder and critical percolation characterize the current path.

Wu, Zhenhua; López, Eduardo; Buldyrev, Sergey V.; Braunstein, Lidia A.; Havlin, Shlomo; Stanley, H. Eugene

2005-04-01

130

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).

1988-01-01

131

Variable-structure braking-resistor control in a multimachine power system  

Energy Technology Data Exchange (ETDEWEB)

This paper describes a variable-structure control for dynamic braking resistors in a multimachine power system to improve the transient performance and thus increase transfer capability. The simulation of a system with 54 buses and 17 generators shows that the new control is very effective for this multimodal system. The control provides very good damping to the appearing oscillation modes and also increases effectively the transient stability limit.

Wang, Y.; Mohler, R.R. (Oregon State Univ., Corvallis, OR (United States). Dept. of Electrical and Computer Engineering); Mittelstadt, W.A. (Bonneville Power Administration, Portland, OR (United States)); Maratukulam, D.J. (Electric Power Research Inst., Palo Alto, CA (United States). Power System Planning and Operation Program)

1994-08-01

132

Refinements in practical accuracy factors for resistor-array IR scene projectors  

Science.gov (United States)

We describe incremental improvements in measurement, understanding and control of sensor-perceived scene accuracy factors for BAe resistor-array IR scene projector devices by means of system and device design, analysis and measurement methodology. Progress has been made in the areas of fill- factor measurement, aliasing effects, dead pixel statistics, image spreading, the design of non-uniformity correction (NUC) systems, busbar robbing, heatsink effects and noise sources.

Pritchard, Alan P.; Venables, Mark A.; Lake, Stephen P.; Gough, David W.

1998-07-01

133

Resonant mode behavior of lumped-resistor-loaded electric-inductive-capacitive resonator and its absorber application  

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents investigations into the resonant mode behavior of a lumped-resistor-loaded electric-inductive-capacitive (ELC) resonator, which is illuminated with a parallel polarization external electromagnetic wave. An ELC resonator exhibits a negative effective permittivity for both parallel and perpendicular polarizations. In contrast to a common ELC resonator, the lumped-resistor-loaded ELC resonator exhibits a switchable resonant mode behavior, thereby revealing a negative effective permeability. In addition, this resonator exhibits a low quality factor owing to the loaded lumped resistors. A metamaterial absorber, which consists of a lumped-resistor-loaded ELC resonator and a cut-wire strip, is designed to confirm the effectiveness of the resonator.

Hong-Min Lee; Hyung-Sup Lee

2013-01-01

134

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

Energy Technology Data Exchange (ETDEWEB)

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.

DIMOS,DUANE B.; KOTULA,PAUL G.; RODRIGUEZ,MARK A.; YANG,PIN

1999-09-08

135

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

UK PubMed Central (United Kingdom)

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.

Ryu H; Kälblein D; Schmidt OG; Klauk H

2011-09-01

136

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

Science.gov (United States)

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

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

2011-08-26

137

New resistor voltage grading system at the Oak Ridge National Laboratory 25URC tandem accelerator; installation and first experience  

Energy Technology Data Exchange (ETDEWEB)

On June 27,1994, installation work was completed on a new resistor-based voltage grading system for the Holifield facility tandem accelerator. This new system replaces the original point-plane corona-discharge system which had inherent disadvantages. Perhaps the worst disadvantages of corona-discharge systems are poor gap-to-gap voltage homogeneity and very low grading currents. It is believed that the resistor-based system will reduce or eliminate these disadvantages as well as some others.

Meigs, M.J.; Haynes, D.L.; Jones, C.M.; Juras, R.C.

1994-12-31

138

Framing the Digital Divide in Higher Education  

Directory of Open Access Journals (Sweden)

Full Text Available This is the introductory article to the monograph "Redefining the Digital Divide in Higher Education". The article describes a comprehensive approach to the phenomenon of the digital divide and digital access, based on Marc Raboy and Mark Warschauer's research. This approach depicts the evolution from mere physical access to effective use of information and communication technologies in the field of higher education. Within this framework, the articles in the monograph are presented highlighting their role in contributing to a comprehensive approach and reflection on the digital divide in Higher Education.

Ismael Peña-López

2010-01-01

139

Frequencies for Pain Reliever Questionnaire Items: Divided ...  

Science.gov (United States)

... Frequencies for Pain Reliever Questionnaire Items: Divided Attention – If stomach pain occurs while taking this product, you can continue to use ... More results from www.fda.gov/drugs/developmentapprovalprocess/developmentresources

140

Democratisation and Conflict in Ethnically Divided Societies  

Directory of Open Access Journals (Sweden)

Full Text Available This article reviews three important factors in the academic debate on ethnic civil wars: the role of ethnicity in causing and structuring violence, the spread of ethnic civil wars once they have started, and the influence of democratic transitions in divided societies. The review displays the range of discussion on conflict, the state and political systems in ethnically divided societies, covering both theoretical and empirical contributions.

Judith Vorrath; Lutz F. Krebs

2009-01-01

 
 
 
 
141

Temporal dynamics of divided spatial attention.  

Science.gov (United States)

In naturalistic settings, observers often have to monitor multiple objects dispersed throughout the visual scene. However, the degree to which spatial attention can be divided across spatially noncontiguous objects has long been debated, particularly when those objects are in close proximity. Moreover, the temporal dynamics of divided attention are unclear: is the process of dividing spatial attention gradual and continuous, or does it onset in a discrete manner? To address these issues, we recorded steady-state visual evoked potentials (SSVEPs) as subjects covertly monitored two flickering targets while ignoring an intervening distractor that flickered at a different frequency. All three stimuli were clustered within either the lower left or the lower right quadrant, and our dependent measure was SSVEP power at the target and distractor frequencies measured over time. In two experiments, we observed a temporally discrete increase in power for target- vs. distractor-evoked SSVEPs extending from ?350 to 150 ms prior to correct (but not incorrect) responses. The divergence in SSVEP power immediately prior to a correct response suggests that spatial attention can be divided across noncontiguous locations, even when the targets are closely spaced within a single quadrant. In addition, the division of spatial attention appears to be relatively discrete, as opposed to slow and continuous. Finally, the predictive relationship between SSVEP power and behavior demonstrates that these neurophysiological measures of divided attention are meaningfully related to cognitive function. PMID:23390315

Itthipuripat, Sirawaj; Garcia, Javier O; Serences, John T

2013-02-06

142

Quality estimation of thick-film resistor terminations based on electrical parameters extraction  

Science.gov (United States)

The RoHS and WEEE regulation forced the large investigations for environmental friendly materials in electronic. The Lead and cadmium which was the significant component of resistors and conductors used in thick-film technology have to be replaced. Quick and precise measurement techniques need to be elaborated to maintain consumer's demand. Usually the test samples with the conductive and resistive layers were used for electrical parameters measurements. The layer thickness measurements and mean value of resistance allowed calculating the sheet resistance. Such a method of measurement have very serious disadvantage. The calculated mean value can be significantly affected by resistors terminations, especially if silver conductor is used, which is known as an easily migrating material. The solution was known and involved preparing and printing samples with the reference terminations. Silver platinum and silver palladium conductors are less susceptible to migration, therefore they were used in previous investigations. The reference terminations improves the precision of calculating sheet resistance, however they enlarges the number of measurements and its influence could still be significant. The authors proposed completely new method of sheet resistance calculation. Such a calculated value called True Sheet Resistance do not depend on the phenomena taking place at the termination, The second evaluated value called Offset indicates the influence of the terminations on measured resistance, and also termination quality. Its value is correlated with the diffusion rate at the interface between conductive film and resistive film at the termination. The usability of this method was proven by performing multiple firing test. One kind of resistive layer was printed on different kinds of conductive layers. The samples were fired sequently and measured. Then the old method of resistor properties evaluation was compared to the new one.

Kie?basi?ski, Konrad; Jakubowska, Ma?gorzata; Kalenik, Jerzy; M?o?niak, Anna

2008-01-01

143

ZnO-based one diode-one resistor device structure for crossbar memory applications  

Science.gov (United States)

This letter reports the development of a ZnO-based one diode-one resistor (1D1R) device consisting of a Pt/ZnO:Al/ZnO/Pt Schottky-type diode and a Pt/ZnO/Pt memristor using a room-temperature sputtering process. The proposed 1D1R device exhibits stable switching for more than 103 cycles, good retention up to 104 s at 85 °C, and desirable anti-crosstalk characteristics. Thus, the proposed design shows potential for integration in a crossbar memory array.

Liu, Zi-Jheng; Gan, Jon-Yiew; Yew, Tri-Rung

2012-04-01

144

Design of an Invisible Radome by Frequency Selective Surfaces Loaded with Lumped Resistors  

Science.gov (United States)

A novel radome is presented, which is transparent at operating frequency and is invisible out of band. In order to prevent reflection of the incoming power, frequency selective surfaces loaded with the lumped resistors are employed. To obtain the pass-band properties in lower frequencies, the convoluted slots are utilized. By comparison with the results obtained both by full wave analysis and by the measurements, the performance of the radome is verified. It performs with high transmission characteristics in band, and broadband absorbing properties out of band simultaneously. The oblique incidences are also investigated for both transmission coefficients and reflection ones.

Liu, Li-Guo; Li, You-Quan; Meng, Qing-Zhi; Wu, Wei-Wei; Mo, Jin-Jun; Fu, Yun-Qi; Yuan, Nai-Chang

2013-06-01

145

Electrical Detection of Self-Assembled Polyelectrolyte Multilayers by a Thin Film Resistor  

CERN Multimedia

The build up of polyelectrolyte multilayers (PEMs) was observed by a silicon-on-insulator (SOI) based thin film resistor. Differently charged polyelectrolytes adsorbing to the sensor surface result in defined potential shifts, which decrease with the number of layers deposited. We model the response of the device assuming electrostatic screening of polyelectrolyte charges by mobile ions within the PEMs. The Debye screening length inside the PEMs was found to be increased compared to the value corresponding to the bulk solution. Furthermore the partitioning of mobile ions between the bulk phase and the polyelectrolyte film was employed to calculate the dielectric constant of the PEMs and the concentration of mobile charges.

Neff, P A; Ecker, C; Nickel, B; Von Klitzing, R; Bausch, A R; Neff, Petra A.; Naji, Ali; Ecker, Christof; Nickel, Bert; Klitzing, Regine von; Bausch, Andreas R.

2006-01-01

146

On the Conduction Mechanism of Silicate Glass Doped by Oxide Compounds of Ruthenium (Thick Film Resistors)  

Directory of Open Access Journals (Sweden)

Full Text Available The results of the investigation of conduction mechanism of silicate glass doped by oxide compounds of ruthenium (thick film resistor) are reported. The formation of diffusion zones in the softened glass during firing process of the mixture of the glass and the dopant powders is considered. As the result the doping glass becomes conductive. These diffusion zones have higher conductivity and act as percolation levels for the free charge carriers. The effect of tem-perature and duration of firing process on the conductivity of doped glass is considered. Experimental results are in a good agreement with the model.

Gulmurza Abdurakhmanov

2011-01-01

147

Ac transport studies in polymers by a resistor network and transfer matrix approaches application to polyaniline  

CERN Multimedia

A statistical model of resistor network is proposed to describe a polymer structure and to simulate the real and imaginary components of its ac resistivity. It takes into account the polydispersiveness of the material as well as intrachain and interchain charge transport processes. By the application of a transfer matrix technique, it reproduces ac resistivity measurements carried out with polyaniline films in different doping degrees and at different temperatures. Our results indicate that interchain processes govern the resistivity behavior in the low frequency region while, for higher frequencies, intrachain mechanisms are dominant.

Nagashima, H N; Faria, R M

1998-01-01

148

Carbon resistors as low temperature sensors in low temperature reactor irradiation experiments  

International Nuclear Information System (INIS)

[en] Several Allen Bradley carbon resistors (type BB, 1/8 W) have been irradiated at 4.6 K in a reactor up to a dose of 3 x 109 r gammas and 2.5 and 2.0 x 1018 cm-2 thermal and fast neutrons respectively. A significant change of the R(T) characteristics is observed after irradiation and after subsequent annealing. For accurate temperature measurements allowance must be made for sufficient radioactivity decay time. A calibration procedure which is particularly suitable for high precision thermopower experiments is also reported. (author)

1977-01-01

149

Thermoluminescence apparatus using PT100 resistors as the heating and sensing elements.  

UK PubMed Central (United Kingdom)

A novel apparatus for obtaining thermoluminescence glow curves is described. Two standard PT100 precision resistors, which have a well-known dependence of resistance on temperature, are connected back to back to provide a sensing and heating element. The resulting hot finger has very low thermal mass, is nonreactive, and is inexpensive. With dry nitrogen gas-flow cooling, an operational range of -50 to 450 degrees C is achievable. A tailored control circuit which is easily calibrated drives the heating element, and temperature ramps are implemented in software. The simple design permits the use of modularly interchangeable hot fingers for rapid measurement of many samples.

Quilty JW; Robinson J; Appleby GA; Edgar A

2007-08-01

150

Thermoluminescence apparatus using PT100 resistors as the heating and sensing elements  

Science.gov (United States)

A novel apparatus for obtaining thermoluminescence glow curves is described. Two standard PT100 precision resistors, which have a well-known dependence of resistance on temperature, are connected back to back to provide a sensing and heating element. The resulting hot finger has very low thermal mass, is nonreactive, and is inexpensive. With dry nitrogen gas-flow cooling, an operational range of -50-450 °C is achievable. A tailored control circuit which is easily calibrated drives the heating element, and temperature ramps are implemented in software. The simple design permits the use of modularly interchangeable hot fingers for rapid measurement of many samples.

Quilty, J. W.; Robinson, J.; Appleby, G. A.; Edgar, A.

2007-08-01

151

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

Energy Technology Data Exchange (ETDEWEB)

Based on a random resistor network (RRN), we study the unusual ac conductivity {sigma}({omega}) of highly conducting polymer such as PF{sub 6} 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. {sigma}({omega}), calculated from this model, reproduces the main experimental features associated with the metal-insulator transition in these polymers.

Zhou Liping [Department of Physics, Suzhou University, Suzhou 215006 (China)]. E-mail: lipichow@hotmail.com; Liu Bo [Department of Physics, Suzhou University, Suzhou 215006 (China); Department of Physics, Jiangsu Teachers University of Technology, Changzhou 213001 (China); Li Zhenya [CCAST (World Laboratory), P.O. Box 8730, Beijing 100080 (China) and Department of Physics, Suzhou University, Suzhou 215006 (China)]. E-mail: zyli@suda.edu.cn

2004-12-06

152

Divide and shape: an endosymbiont in action.  

UK PubMed Central (United Kingdom)

The endosymbiotic evolution of the plastid within the host cell required development of a mechanism for efficient division of the plastid. Whilst a model for the mechanism of chloroplast division has been constructed, little is known of how other types of plastids divide, especially the proplastid, the progenitor of all plastid types in the cell. It has become clear that plastid shape is highly heterogeneous and dynamic, especially stromules. This article considers how such variation in morphology might be controlled and how such plastids might divide efficiently.

Pyke KA

2013-02-01

153

Bridging the digital divide with mobile services  

CERN Document Server

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.

Yelton, Andromeda

2013-01-01

154

Computing ULV Decomposition by Divide Conquer Method  

Directory of Open Access Journals (Sweden)

Full Text Available The ULV decomposition (ULVD) is an important member of a class of rank-revealing two-sided orthogonal decompositions used to approximate the Singular Value Decomposition (SVD). The ULVD can be modified much faster than the SVD. The accurate computation of the subspaces is required in applications in signal processing. In this study we introduce a divide conquer ULVD algorithm.

Hasan Erbay; Jesse L. Barlow

2005-01-01

155

The Russian-Ukrainian Political Divide  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The Orange Revolution unveiled significant political and economic tensions between ethnic Russians and Ukrainians in Ukraine. Whether this divide was caused by purely ethnic differences or by ethnically segregated reform preferences is unknown. Analysis using unique micro data collected prior to the...

Constant, Amelie F.; Kahanec, Martin; Zimmermann, Klaus F.

156

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

Directory of Open Access Journals (Sweden)

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.

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

2011-01-01

157

Bruce B Unit 6 divider plate sealing skin installation  

Energy Technology Data Exchange (ETDEWEB)

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)

Fortin, L. [Ontario Power Generation, Bruce Nuclear, Tiverton, Ontario (Canada)

2000-07-01

158

Interface analysis of embedded chip resistor device package and its effect on drop shock reliability.  

UK PubMed Central (United Kingdom)

In this study, the drop reliability of an embedded passive package is investigated under JESD22-B111 condition. Chip resistors were buried in a PCB board, and it was electrically interconnected by electroless and electrolytic copper plating on a tin pad of a chip resistor without intermetallic phase. However tin, nickel, and copper formed a complex intermetallic phase, such as (Cu, Ni)6Sn5, (Cu, Ni)3Sn, and (Ni, Cu)3Sn2, at the via interface and via wall after reflow and aging. Since the amount of the tin layer was small compared with the solder joint, excessive intermetallic layer growth was not observed during thermal aging. Drop failures are always initiated at the IMC interface, and as aging time increases Cu-Sn-Ni IMC phases are transformed continuously due to Cu diffusion. We studied the intermetallic formation of the Cu via interface and simulated the stress distribution of drop shock by using material properties and board structure of embedded passive boards. The drop simulation was conducted according to the JEDEC standard. It was revealed that the crack starting point related to failure fracture changed due to intermetallic phase transformation along the via interface, and the position where failure occurs experimentally agrees well with our simulation results.

Park SH; Kim SK; Kim YH

2012-04-01

159

Interface analysis of embedded chip resistor device package and its effect on drop shock reliability.  

Science.gov (United States)

In this study, the drop reliability of an embedded passive package is investigated under JESD22-B111 condition. Chip resistors were buried in a PCB board, and it was electrically interconnected by electroless and electrolytic copper plating on a tin pad of a chip resistor without intermetallic phase. However tin, nickel, and copper formed a complex intermetallic phase, such as (Cu, Ni)6Sn5, (Cu, Ni)3Sn, and (Ni, Cu)3Sn2, at the via interface and via wall after reflow and aging. Since the amount of the tin layer was small compared with the solder joint, excessive intermetallic layer growth was not observed during thermal aging. Drop failures are always initiated at the IMC interface, and as aging time increases Cu-Sn-Ni IMC phases are transformed continuously due to Cu diffusion. We studied the intermetallic formation of the Cu via interface and simulated the stress distribution of drop shock by using material properties and board structure of embedded passive boards. The drop simulation was conducted according to the JEDEC standard. It was revealed that the crack starting point related to failure fracture changed due to intermetallic phase transformation along the via interface, and the position where failure occurs experimentally agrees well with our simulation results. PMID:22849085

Park, Se-Hoon; Kim, Sun Kyoung; Kim, Young-Ho

2012-04-01

160

Low noise charge sensitive preamplifier DC stabilized without a physical resistor  

Energy Technology Data Exchange (ETDEWEB)

The invention is a novel charge sensitive preamplifier (CSP) which has no resistor in parallel with the feedback capacitor. No resetting circuit is required to discharge the feedback capacitor. The DC stabilization of the preamplifier is obtained by means of a second feedback loop between the preamplifier output and the common base transistor of the input cascode. The input transistor of the preamplifier is a Junction Field Transistor (JFET) with the gate-source junction forward biased. The detector leakage current flows into this junction. This invention is concerned with a new circuit configuration for a charge sensitive preamplifier and a novel use of the input Field Effect Transistor of the CSP itself. In particular this invention, in addition to eliminating the feedback resistor, eliminates the need for external devices between the detector and the preamplifier, and it eliminates the need for external circuitry to sense the output voltage and reset the CSP. Furthermore, the noise level of the novel CSP is very low, comparable with the performance achieved with other solutions. Experimental tests prove that this configuration for the charge sensitive preamplifier permits an excellent noise performance at temperatures including room temperature. An equivalent noise charge of less than 20 electrons r.m.s. has been measured at room temperature by using a commercial JFET as input device of the preamplifier.

Bertuccio, Giuseppe (Brianza, IT); Rehak, Pavel (Patchogue, NY); Xi, Deming (Beijing, CN)

1994-09-13

 
 
 
 
161

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

International Nuclear Information System (INIS)

[en] 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

1984-04-01

162

Coulomb blockade and cotunneling in single electron circuits with on-chip resistors towards the implementation of R-pump  

CERN Multimedia

We report on the investigation of Al single electron structures equipped with miniature (8 um long) on-chip Cr resistors of R > R_k = h/e^2 = 25.8 kOhm. From the measurement of the Coulomb blockade in single-junction structures we evaluated the self-capacitance of our resistors per unit length, c = 62 aF/um. We demonstrate that the cotunneling current in the transistor samples in the Coulomb blockade regime obeys the power law, $I \\propto V^{3+(R/R_k)}$, predicted by Odintsov, Bubanja and Schön for a transistor having pure ohmic-resistance leads. The concept of the three-junction single electron pump with on-chip resistors (R-pump) is developed. We demonstrate that the implementation of the R-pump with a relative accuracy of the electron transfer of 10^{-8} is quite feasible with the technology available.

Zorin, A B; Zangerle, H; Niemeyer, J C

1999-01-01

163

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

Science.gov (United States)

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 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 computationally efficient method than the classical GFEM.

164

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

Energy Technology Data Exchange (ETDEWEB)

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 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 computationally efficient method than the classical GFEM. 9 figs., 2 tabs.

1987-01-01

165

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

Directory of Open Access Journals (Sweden)

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.How to cite this article: Sedimo, N.C., Bwalya, K.J. & Du Plessis, T., 2011,‘Conquering the digital divide: Botswana and South Korea digital divide status and interventions’, SA Journal of Information Management 13(1), Art. #471, 10 pages.http://dx.doi.org/10.4102/sajim.v13i1.471

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

2011-01-01

166

Analyzing Broadband Divide in the Farming Sector  

DEFF Research Database (Denmark)

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.

Jensen, Michael; Gutierrez Lopez, Jose Manuel

2013-01-01

167

DIGITAL DIVIDE IN INDIA: PROBLEMS AND PROSPECTS TO BRIDGE THE DIVIDE  

Directory of Open Access Journals (Sweden)

Full Text Available 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 divide in India. The Government of India and different state governments have already took developmental measures to control the digital divide. The present paper explained different government schemes, measures and programmes, which are aimed to overcome the digital divide and thereby enabling development of the digital libraries in India.

PRAVEENKUMAR KUMBARGOUDAR

2013-01-01

168

Counterexamples regarding Symmetric Tensors and Divided Powers  

CERN Document Server

We investigate the similarities and differences between the module of symmetric tensors TS^n_A(M) and the module of divided powers \\Gamma^n_A(M). There is a canonical map \\Gamma^n_A(M) \\to TS^n_A(M) which is an isomorphism in many important cases. We give examples showing that this map need neither be surjective nor injective in general. These examples also show that the functor TS_A^n does not in general commute with base change.

Lundkvist, C

2007-01-01

169

Divide-and-Conquer Multiple Sequence Alignment  

UK PubMed Central (United Kingdom)

dvantage of this fact by rst dividings1 at its midpoint ^ c1 := djs 1 j=2e and then searchingfor compatible positions in the other sequences.To estimate the compatibility of slicing positions c, d ofsequences s, t, we dene the additional cost C s;t [c; d]imposed by rst slicing s and t at c and d, respectively,and then aligning s and t by concatenating the optimalalignments of the resulting prex and sux sequences byC s;t [c; d] := w opt (prex) + w opt (sux) w opt (total)w

Universitt Bielefeld; J. Stoye; S. W. Perrey; A. W. M. Dress

170

Microwave power divider with arbitrary distribution ratio  

International Nuclear Information System (INIS)

As is well known, the EM field of TE11 mode at the wall of the circular waveguide changes as sine (or cosine) function azimuthally. So when we attach two perpendicular waveguides to the wall of the circular waveguide and rotate them around the axis of the waveguide, authors can distribute the input power between the two waveguides with arbitrary distribution proportion. The authors have designed a new power divider following this idea. The 3D electromagnetic simulation software HFSS is used in the design. And a new type circular TE11 mode launcher is developed. (author)

2004-01-01

171

Are food webs divided into compartments  

Energy Technology Data Exchange (ETDEWEB)

The structure of real food webs, to see if they are, or are not, divided into compartments. The webs are defined by binary data: a feeding link either exists, or it does not. Analysis is therefore modest and preliminary, taking no account or the strength or the seasonal variation of the efeeding links. If compartments can be shown to exist using binary data they will remain in more sophisticated descriptions of food webs. If compartments can not be identified using binary data, the case for the existence of subsystems within food webs is weakened, but not destroyed.

Pimm, S.L. (Oak Ridge National Lab., TN); Lawton, J.H.

1980-01-01

172

Positive temperature coefficient resistor behavior in praseodymium-doped ZnO (0001)|(0001) boundaries  

Science.gov (United States)

Clear positive temperature coefficient resistor (PTCR) dc behavior has been shown in Pr-doped ZnO (0001)|(0001) bicrystals by electrical characterization over an unprecedentedly wide temperature range between 40 and 1070 K. With subtraction of the PTCR dc, the admittance can be described by a deep trap level at 0.26 eV but no clue to the origin of the PTCR behavior is provided. Capacitance-voltage characteristics revealed a maximum in the Schottky barrier heights consistent with the PTCR behavior. The PTCR behavior in Pr-doped ZnO c-axis oriented bicrystals is thus phenomenologically analogous to that of the ferroelectric BaTiO3.

Lee, Jong-Sook; Kim, Yong; Shin, Eui-Chol; Maier, Joachim

2010-05-01

173

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

UK PubMed Central (United Kingdom)

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.

Kim W; Riikonen J; Li C; Chen Y; Lipsanen H

2013-10-01

174

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

2007-05-11

175

The behaviour of Ru based thick film resistor as a comonent of LCR network  

Energy Technology Data Exchange (ETDEWEB)

The Ru-based thick film resistor(TFR) for sintering at 900 deg. C was synthesized to prepare the LCR network. These compositions of pyrochlore could be prepared by decreasing the amount of PbO and increasing alumina and silica contents of glass frit. In this study, the sheet resistances of the TFRs which were sintered at 900 deg. C after printing on alumina substrate, the sheet resistances of the TFRs on inductor and capacitor substrate and the interphase between TFR and substrate were observed. And the changes of the sheet resistance were obtained with the contents of RuO{sub 2}. In case of the TFR sintered at 900 deg. C, the sheet resistances on alumina substrates were in the range of 10{sup 3}-10{sup 6} {Omega}/{open_square}, but the sheet resistances of TFR on inductor and capacitor substrate were not obtained. (author)13 refs., 8 figs., 3 tabs.

Park, J.A.; Lee, H. L.; Moon, J.W.; Kim, G.D.; Lee, D. A.; Son, Y.B. [Yonsei University, Seoul (Korea, Republic of)

1997-03-01

176

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

Science.gov (United States)

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.

Kim, Wonjae; Riikonen, Juha; Li, Changfeng; Chen, Ya; Lipsanen, Harri

2013-10-01

177

Electrical properties and stability of Tb-doped zinc oxide-based nonlinear resistors  

Science.gov (United States)

The microstructure, electric field current density (E J), capacitance voltage (C V), and stability characteristics of Zn Pr Co Cr Tb oxide-based nonlinear resistors were investigated for different Tb4O7 amounts. It increased in the range of 8.9 42.0 in the nonlinear coefficient and in the range of 1026 6514 V/cm in the breakdown field with increasing Tb4O7 amount. As Tb4O7 amount increased, the donor density decreased in the range of 1.23×1018 0.70×1018/cm3, whereas the barrier height at grain boundaries increased in the range of 0.73 0.93 eV. A good stability was obtained in the range of 0.25 0.5 mol% in Tb4O7 amount.

Nahm, C.-W.

2007-03-01

178

Novel p-JFET embedded in silicon radiation detectors that avoids preamplifier feedback resistor  

International Nuclear Information System (INIS)

[en] The paper describes the design and the performance of an original p-channel JFET embedded in the collecting anode of a silicon radiation detector. The choice of a p-channel transistor, whose gate-to-channel junction is forward biased by the leakage current from the detector, avoids the preamplifier feedback resistor and performs a continuous dc reset of the collected charge. The reported design, fully compatible with the detector fabrication, makes the operation of the detector extremely simple, ensures the best charge collection capability and leads to improved charge resolution. The first detector produced with this type of transistor has a resolution of 27 electrons rms in the measurement of the collected charge at room temperature for a pixel active area of about 0.1 mm2, and of 22 electrons rms at T = 210 K

1995-01-01

179

Calibration of the scanning thermometer resistor system for a superconducting accelerating cavity  

Energy Technology Data Exchange (ETDEWEB)

A calibration measurement for the temperature mapping system in use at CERN for superconducting accelerating cavities immersed in subcooled liquid helium is presented. It allows a study of cavity losses in a quantitative way by relating the temperature increase (deltaT) at the cavity outside wall to the power dissipated at the inside. The calibration set up simulates an isolated lossy region in a superconducting cavity. The influence of the bath temperature and the orientation of the heated surface have been investigated. deltaT is determined by the heat current density Q at the resistor location according to deltaT = ..cap alpha.. Q /SUP 3/4/ . The proportionality constant ..cap alpha.. depends on the particular experimental conditions. The experimental results are compared with heat transfer calculations in subcooled helium. As an application typical loss mechanisms in superconducting cavities are described.

Romijn, R.; Piel, W.; Weingarten, W.

1983-05-01

180

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

Directory of Open Access Journals (Sweden)

Full Text Available Low power consumption, long battery life and portability are essential requirements of modern healthmonitoring products. Operational Transconductance Amplifier (OTA) operating in subthreshold region isan basic building block for low power health monitoring products design. An modified design of OTAwhich incorporates better linearity and increased output impedance has been discussed in this paper. Theproposed OTA uses High-swing improved-Wilson current mirror for low power and low-frequencyapplications. The achieved linearity is about ± 1.9 volt and unity gain bandwidth (UGB) of 342.30 KHz atpower 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. Thecircuit 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.

Nikhil Raj; R.K.Sharma

2010-01-01

 
 
 
 
181

Thermocapillary actuation by optimized resistor pattern: bubbles and droplets displacing, switching and trapping.  

Science.gov (United States)

We report a novel method for bubble or droplet displacement, capture and switching within a bifurcation channel for applications in digital microfluidics based on the Marangoni effect, i.e. the appearance of thermocapillary tangential interface stresses stemming from local surface tension variations. The specificity of the reported actuation is that heating is provided by an optimized resistor pattern (B. Selva, J. Marchalot and M.-C. Jullien, An optimized resistor pattern for temperature gradient control in microfluidics, J. Micromech. Microeng., 2009, 19, 065002) leading to a constant temperature gradient along a microfluidic cavity. In this context, bubbles or droplets to be actuated entail a surface force originating from the thermal Marangoni effect. This actuator has been characterized (B. Selva, I. Cantat, and M.-C. Jullien, Migration of a bubble towards a higher surface tension under the effect of thermocapillary stress, preprint, 2009) and it was found that the bubble/droplet (called further element) is driven toward a high surface tension region, i.e. toward cold region, and the element velocity increases while decreasing the cavity thickness. Taking advantage of these properties three applications are presented: (1) element displacement, (2) element switching, detailed in a given range of working, in which elements are redirected towards a specific evacuation, (3) a system able to trap, and consequently stop on demand, the elements on an alveolus structure while the continuous phase is still flowing. The strength of this method lies in its simplicity: single layer system, in situ heating leading to a high level of integration, low power consumption (P < 0.4 W), low applied voltage (about 10 V), and finally this system is able to manipulate elements within a flow velocity up to 1 cm s(-1). PMID:20445893

Selva, Bertrand; Miralles, Vincent; Cantat, Isabelle; Jullien, Marie-Caroline

2010-05-05

182

Thermocapillary actuation by optimized resistor pattern: bubbles and droplets displacing, switching and trapping.  

UK PubMed Central (United Kingdom)

We report a novel method for bubble or droplet displacement, capture and switching within a bifurcation channel for applications in digital microfluidics based on the Marangoni effect, i.e. the appearance of thermocapillary tangential interface stresses stemming from local surface tension variations. The specificity of the reported actuation is that heating is provided by an optimized resistor pattern (B. Selva, J. Marchalot and M.-C. Jullien, An optimized resistor pattern for temperature gradient control in microfluidics, J. Micromech. Microeng., 2009, 19, 065002) leading to a constant temperature gradient along a microfluidic cavity. In this context, bubbles or droplets to be actuated entail a surface force originating from the thermal Marangoni effect. This actuator has been characterized (B. Selva, I. Cantat, and M.-C. Jullien, Migration of a bubble towards a higher surface tension under the effect of thermocapillary stress, preprint, 2009) and it was found that the bubble/droplet (called further element) is driven toward a high surface tension region, i.e. toward cold region, and the element velocity increases while decreasing the cavity thickness. Taking advantage of these properties three applications are presented: (1) element displacement, (2) element switching, detailed in a given range of working, in which elements are redirected towards a specific evacuation, (3) a system able to trap, and consequently stop on demand, the elements on an alveolus structure while the continuous phase is still flowing. The strength of this method lies in its simplicity: single layer system, in situ heating leading to a high level of integration, low power consumption (P < 0.4 W), low applied voltage (about 10 V), and finally this system is able to manipulate elements within a flow velocity up to 1 cm s(-1).

Selva B; Miralles V; Cantat I; Jullien MC

2010-07-01

183

HEATING SHEETS WITH RESISTOR AUTOMATICALLY TEMPERATURE-CONTROLLED BY POSITIVE TEMPERATURE COEFFICIENT (PTC) EFFECT AND USES THEREOF  

UK PubMed Central (United Kingdom)

The invention concerns a heating sheet comprising at least a conductive polymer layer with resistor automatically temperature-controlled by PTC effect placed between at least two electrically conductive surfaces and its use in building and construction, undersea energy transport, human and animal health care, food industry or process control industry.

CAUPIN Henri-Jean; KORZHENKO Alexander; SHARPE HILL Robert

184

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

185

Cell therapy unit, has high voltage power supply connected to coil and storage capacitor through variable capacity resistor capacity network  

UK PubMed Central (United Kingdom)

A cell therapy unit has a mains driven high voltage power supply (SNT) and coil (COIL) connected storage capacitor (CAP) charged through an electronic diode or thyristor switch (SWITCH) and rectifier (RECT) and parallel or series variable capacity resistor capacitor network (RC1, RCII).

186

Al-doped Ni-Cr for temperature coefficient of resistance control in hybrid thin-film resistors  

Science.gov (United States)

The temperature coefficient of resistance (TCR) was tailored by doping standard 60/40 nickel-chromium resistor film to reduce the TCR from about 100 ppm/C to about 0 ppm/C. For constant sheet resistance films, TCR was a function of both substrate surface roughness and dopant concentration. TCR may be kept near zero for a wide variety of hybrid substrate materials with varied surface finishes by changing dopant concentration in the sputtering target. By controlling alloy composition to 0.1 wt pct, using powder metallurgy techniques, TCR was controlled to + or - 5 ppm/C for a constant sheet resistance and invariant substrate surface finish. Because rough substrates required thicker films to obtain the same sheet resistance, the factors which controlled TCR were slightly modified. The effect was an increase in TCR for the same resistance value. Doped resistors on aluminum oxide were slightly less stable in the high temperature storage test than undoped resistors. However, because their TCR was so much lower, the change in resistance during operation of a real circuit was less than one-fourth the change in undoped resistors used on the same circuit.

Bayne, M. A.

1986-12-01

187

Long-term Correlations and 1/f^alpha Noise in the Steady States of Multi-Species Resistor Networks  

CERN Multimedia

We introduce a multi-species network model which describes the resistance fluctuations of a resistor in a non-equilibrium stationary state. More precisely, a thin resistor characterized by a 1/f^alpha resistance noise is described as a two-dimensional network made by different species of elementary resistors. The resistor species are distinguished by their resistances and by their energies associated with thermally activated processes of breaking and recovery. Depending on the external conditions, stationary states of the network can arise as a result of the competition between these processes. The properties of the network are studied as a function of the temperature by Monte Carlo simulations carried out in the temperature range 300 \\div 800 K. At low temperatures, the resistance fluctuations display long-term correlations expressed by a power-law behavior of the auto-correlation function and by a value approx 1 of the alpha-exponent of the spectral density. On the contrary, at high temperatures the resista...

Pennetta, C; Reggiani, L

2007-01-01

188

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

Energy Technology Data Exchange (ETDEWEB)

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 {times} 24 in.W {times} 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.

Visser, A.T.

1990-03-01

189

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

1990-01-01

190

The Digital Divide and urban older adults.  

Science.gov (United States)

Computers and the Internet offer older adults opportunities and resources for independent living. However, many urban older adults do not use computers. This study examined the demographic, health, and social activities of urban older adults to determine variables that might predict the use and nonuse of computers in this population. A secondary data analysis was performed using the 2001 Detroit City-Wide Needs Assessment of Older Adults (n = 1410) data set. Logistic regression was used to explore potential differences in predictor variables between computer users and nonusers. Overall, computer users were younger (27%), had a higher level of education, were more likely to be employed, had an annual income greater than $20,000, and were healthier and more active than nonusers. They also were more likely to have memberships in community organizations and do volunteer work. Preferred computer activities included conducting Internet searches, playing games, writing, and communicating with family members and friends. The results suggest significant differences in demographic and health-related characteristics between computer users and nonusers among urban older adults. Although about a quarter of participants in this study used computers, the Digital Divide continues to exist in urban settings for scores of others. PMID:20182159

Cresci, M Kay; Yarandi, Hossein N; Morrell, Roger W

191

Climate of concern - bridging the divide  

Energy Technology Data Exchange (ETDEWEB)

Developments at the negotiations on the CRN Framework Convention on Climate Change show the world is still divided on the climate change problem - the political from the scientific and industrialized from the developing. The Kyoto Protocol is still not fully developed. In this context the Tata Energy Research Institute (TERI) undertook a survey based on literature, personal interviews and questionnaires to synthesize the views of experts on their perceptions on the strengths and limitations of the Kyoto Protocol and the required steps forward. The results are summarized in this paper which is an abridged version of a presentation to the workshop on North-South strategies for sustainable development held during COP-5 in Bonn, Germany in November 1999 (full text available on the Internet at: www.teriin.org/climate/cop-5.htm). There was a large divergence of views on the Kyoto Protocol, some endorsing the flexible mechanisms, some objecting. Although a long term agreement to limit greenhouse gases was considered essential the survey found that it should not dominate the negotiations to the extent of ignoring short-term goals. 9 refs., 4 figs.

NONE

1999-12-01

192

Bridging the divide between science and journalism.  

UK PubMed Central (United Kingdom)

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.

Van Eperen L; Marincola FM; Strohm J

2010-01-01

193

Vegetation baseline report : Connacher great divide project  

Energy Technology Data Exchange (ETDEWEB)

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

NONE

2005-08-01

194

The Digital Divide and urban older adults.  

UK PubMed Central (United Kingdom)

Computers and the Internet offer older adults opportunities and resources for independent living. However, many urban older adults do not use computers. This study examined the demographic, health, and social activities of urban older adults to determine variables that might predict the use and nonuse of computers in this population. A secondary data analysis was performed using the 2001 Detroit City-Wide Needs Assessment of Older Adults (n = 1410) data set. Logistic regression was used to explore potential differences in predictor variables between computer users and nonusers. Overall, computer users were younger (27%), had a higher level of education, were more likely to be employed, had an annual income greater than $20,000, and were healthier and more active than nonusers. They also were more likely to have memberships in community organizations and do volunteer work. Preferred computer activities included conducting Internet searches, playing games, writing, and communicating with family members and friends. The results suggest significant differences in demographic and health-related characteristics between computer users and nonusers among urban older adults. Although about a quarter of participants in this study used computers, the Digital Divide continues to exist in urban settings for scores of others.

Cresci MK; Yarandi HN; Morrell RW

2010-03-01

195

Design of Improved Resistor Less 45NM Switched Inverter Scheme (SIS) Analog to Digital Converter  

Directory of Open Access Journals (Sweden)

Full Text Available This work presents three different approaches which eliminates the resistor ladder completely and hencereduce the power demand drastically of a Analog to Digital Converter. The first approach is SwitchedInverter Scheme (SIS) ADC; The test result obtained for it on 45nm technology indicates an offset error of0.014 LSB. The full scale error is of -0.112LSB. The gain error is of 0.07 LSB, actual full scale range of0.49V, worst case DNL & INL each of -0.3V. The power dissipation for the SIS ADC is 207.987 ?watts;Power delay product (PDP) is 415.9 fWs, and the area is 1.89?m2. The second and third approaches areclocked SIS ADC and Sleep transistor SIS ADC. Both of them show significant improvement in powerdissipation as 57.5% & 71% respectively. Whereas PDP is 229.7 fWs and area is 0.05 ?m2 for Clocked SISADC and 107.3 fWs & 1.94 ?m2 for Sleep transistor SIS ADC.

Arun Kumar Sunaniya; Kavita Khare

2013-01-01

196

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

International Nuclear Information System (INIS)

[en] 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

2003-06-25

197

Tunneling in thick-film (cermet) resistors and the minimum of resistance  

International Nuclear Information System (INIS)

[en] The electrical transport in thick-film resistors (TFRs) is actually an active fild of investigation on both theoretical and experimental bases. Previously it has been shown that tunneling of electrons between neighbouring grains could explain a large spectrum of experimental findings and it has been proposed that the minimum of resistance of TFRs is due to a trade-off between the negative temperature coeeficient of the resistance of the tunneling barrier and the positive temperature coefficient of the metal-oxide grains. In this paper the approach is re-examined and it is shown that a more satisfactory interpretation of the minimum of resistance is obtained by neglecting the resistance of the grainsand assuming a slight increase of the tunneling barrier height at increasing temperatures. Under this assumption a very good agreement between experimental and theoretical values is found for the temperature coefficient of resistance of TFRs over a temperature range from 77 to 600 K. The possible origins of the temperature dependence of the barrier height are discussed and the practical consequence of the proposed model emphasized

1983-01-01

198

Calculating two-point resistances in distance-regular resistor networks  

Science.gov (United States)

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_{\\alpha\\beta^{(i)}} , ? belonging to the ith stratum with respect to the ?) are the same. Also, the analytical formulae for two-point resistances R_{{\\alpha\\beta^{(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.

Jafarizadeh, M. A.; Sufiani, R.; Jafarizadeh, S.

2007-05-01

199

Calculating two-point resistances in distance-regular resistor networks  

Energy Technology Data Exchange (ETDEWEB)

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 {alpha} and all nodes {beta} belonging to the same stratum with respect to the {alpha} (R{sub {alpha}}{sub {beta}{sup (i)}}), {beta} belonging to the ith stratum with respect to the {alpha}) are the same. Also, the analytical formulae for two-point resistances R{sub {alpha}}{sub {beta}{sup (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, {kappa}, {lambda}, {mu}). Moreover, the lower and upper bounds for two-point resistances in strongly regular networks are discussed.

Jafarizadeh, M A [Department of Theoretical Physics and Astrophysics, University of Tabriz, Tabriz 51664 (Iran, Islamic Republic of); Sufiani, R [Department of Theoretical Physics and Astrophysics, University of Tabriz, Tabriz 51664 (Iran, Islamic Republic of); Jafarizadeh, S [Department of Electrical and computer engineering, University of Tabriz, Tabriz 51664 (Iran, Islamic Republic of)

2007-05-11

200

Power system stabilization by a combined control using superconducting magnetic energy storage with system damping resistors  

Energy Technology Data Exchange (ETDEWEB)

Efficient power system stabilization control was examined using a control model combined with a superconducting magnetic energy storage (SMES) with system damping resistors(SDR), and the estimation method of required capacities was proposed for the SMES and SDR. A one-machine infinite-bus system was adopted as the model assuming long-distance large scale transmission, and the SMES and SDR were connected to the system end near a generator. As the results of numerical analyses, frequent small undamped power oscillations could be effectively stabilized by only the SMES, and large oscillations could be effectively stabilized by the SMES after oscillations were depressed by the suitably connected SDRs. A converter of 580MVA in capacity and energy of 200MJ were required to stabilize the power system of 2000MVA by only SMES, and on the other hand, a converter of only 230MVA and energy of only 150MJ were required as the SDR of 1000MVA was combined with the system. 6 refs., 11 figs., 2 tabs.

Mitani, Yasunori; Tsuji, Kiichiro; Murakami, Yoshishige (Osaka Univ. (Japan))

1988-08-01

 
 
 
 
201

Determining level of postural control in young adults using force-sensing resistors.  

UK PubMed Central (United Kingdom)

A force-sensing platform (FSP), sensitive to changes of the postural control system was designed. The platform measured effects of postural perturbations in static and dynamic conditions. This paper describes the implementation of an FSP using force-sensing resistors as sensing elements. Real-time qualitative assessment utilized a rainbow color scale to identify areas with high force concentration. Postprocessing of the logged data provided end-users with quantitative measures of postural control. The objective of this research was to establish the feasibility of using an FSP to test and gauge human postural control. Tests were conducted in eye open and eye close states. Readings obtained were tested for repeatability using a one-way analysis of variance test. The platform gauged postural sway by measuring the area of distribution for the weighted center of applied pressure at the foot. A fuzzy clustering algorithm was applied to identify regions of the foot with repetitive pressure concentration. Potential application of the platform in a clinical setting includes monitoring rehabilitation progress of stability dysfunction. The platform functions as a qualitative tool for initial, on-the-spot assessment, and quantitative measure for postacquisition assessment on balance abilities.

Gopalai AA; Senanayake SM; Gouwanda D

2011-07-01

202

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

Science.gov (United States)

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.

Hu, X. B.; Hu, C. Z.; Yin, D. P.; Zhang, L. Y.; Zhang, C. N.; Chen, Y.; Zhang, G. Q.; Yang, R.; Liang, K.; Musienko, Yu.; Han, D. J.

2012-12-01

203

Enhancement of transient stability using fault current limiter and braking resistor  

Energy Technology Data Exchange (ETDEWEB)

Replacement of aging substation equipment is needed in order to maintain the stability of electric power systems which are becoming increasingly interconnected. This paper addressed the issue of using fault current limiters (FCLs) as a means of limiting fault currents and enhancing the transient stability of a power system. FCL limits the fault current by generating an impedance when a fault occurs. The limiting impedance helps to increase generator output degraded by a fault, thus providing stabilization. However, FCLs installed in series with transmission lines can only be operated during the period from the fault occurrence to the fault clearing. Therefore, they cannot control the generator disturbances after the clearing of a fault. However, in the event of power failures, thyristor controlled braking resistors (TCBRs) can quickly control generator disturbances. Therefore, the authors proposed the use of both FCL and TCBR devices to enhance transient stability and damp the turbine shaft torsional oscillations. The effectiveness of both devices on suppression of the turbine shaft torsional oscillations was illustrated through simulations performed in EMTP/ATP considering three-lines-to-ground fault. It was shown that if both devices operate at the same bus, the stabilization control scheme can be carried out continuously and with flexibility from the fault occurrence instance, thereby effectively improving transient stability. 7 refs., 2 tabs., 10 figs.

Yagami, M.; Hiratsuka, Y. [Hokkaido Inst. of Technology, Sapporo, Hokkaido (Japan); Tamura, J. [Kitami Inst. of Technology, Kitami, Hokkaido (Japan)

2006-07-01

204

GaAs resistor structures for X-ray imaging detectors  

CERN Document Server

Unlike conventional GaAs detector structures, which operation is based on the use of a space charge region of a barrier structure, we propose to form a detector structure of resistor type. In this case, the electric field distribution, xi(x), is not screened by the ion concentration in the SCR but it is defined only by the uniformity of the resistance value distribution in the structure. The experimental results on charge collection efficiency for the detector irradiation with alpha, beta, gamma-radiation are presented. It is shown that the amplitude spectrum shape in the case of interaction with gamma-radiation is defined mainly by the electron component of the charge. The simulation of the detector response function confirms it. It is established that, despite of hole trapping, it is possible to achieve high values of charge collection efficiency of gamma-radiation. Explanation of the charge collection efficiency dependence on a type of ionizing radiation is made. Problems of design of the detector with hig...

Ayzenshtat, G I; Koretskaya, O B; Novikov, V A; Okaevich, L S; Potapov, A I; Tolbanov, O P; Tyazhev, A V; Vorobev, A P

2002-01-01

205

DVCCs Based High Input Impedance Voltage-Mode First-Order Filters Employing Grounded Capacitor and Resistor  

Directory of Open Access Journals (Sweden)

Full Text Available A voltage-mode high input impedance first-order highpass, lowpass and allpass filters using two differential voltage current conveyors (DVCCs), one grounded capacitor and one grounded resistor is presented. The highpass, lowpass and allpass signals can be obtained simultaneously from the circuit configuration. The suggested filter uses a canonical number of passive components without requiring any component matching condition. The simulation results confirm the theoretical analysis.

J. W. Horng

2010-01-01

206

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

1988-01-01

207

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  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese 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 h (more) idráulicas 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. Abstract in english 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 compart (more) ments 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 frequen

Rocha, Marlon Gomes da; Faria, Leandro Neves; Casaroli, Derblai; Van Lier, Quirijn de Jong

2010-08-01

208

Acoustic-optical time-dividing channeling system  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The possibility of using the peculiarities of acoustic-optical effect for time-dividing channeling is considered; structure-electric scheme of acoustic-optical time-dividing channeling system is suggested; recommendations on choosing its parameters are elaborated.

Pashaev, A. M.; National Academy of Aviation; Gasanov, A. R.; National Academy of Aviation; Sultanov, V. Z.; National Academy of Aviation

209

Policy Options to Combat the Digital Divide in Western Europe  

Directory of Open Access Journals (Sweden)

Full Text Available 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 partnerships.

Rod Carveth; Susan B. Kretchmer

2002-01-01

210

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

International Nuclear Information System (INIS)

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

2001-01-01

211

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

Science.gov (United States)

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

Stratos, David; Maria, Georgiou; Eleftherios, Fysikopoulos; George, Loudos

2013-02-01

212

A closed-loop quasi-optimal dynamic braking resistor and shunt reactor control strategy for transient stability  

Energy Technology Data Exchange (ETDEWEB)

A control strategy for dynamic braking resistor and shunt reactor is proposed for stabilization of power systems when subject to large disturbances. The time optimal control is derived as a function of synchronous machine power, its rotor angular position and speed deviation. The response for a single machine system with the proposed control has been compared with that from the time optimal solution obtained through the steepest descent method. The strategy has also been tested on two multimachine systems. Results indicate that the proposed strategy provides a simple and effective method of stabilization under transient emergency conditions.

Rahim, A.H.M.A.; Alamgir, D.A.H.

1988-08-01

213

An Efficiednt Programmable Frequency Divider with Improved Division Ratio  

Directory of Open Access Journals (Sweden)

Full Text Available The frequency divider is an important building block in today’s high speed integrated circuits. Frequency divider is the most power hungry block in the communication system. Considering the scope of the frequency divider An Efficient Programmable Frequency Divider (PD) is presented. In this paper a shared counter with a small control circuit is exploited using Reduced Module Control Signal generator (RMCS).This will reduce the output load capacitance and the redundant counter operations in the divider. A Dual Modules Prescaler (DMP), which gives initial division ratio for the input signal by N or N+1.Dividing factor of the Efficient PD can increased by modifying DMP circuit for 16 or 17. A novel glitch less D flip-flop is also designed by considering the switching activities of the internal nodes of the flip-flop.

N.Kirthika; Nisha Lali .R; Rejeesh.R S

2012-01-01

214

Improvement of dividers for fast and very fast hv transients  

Energy Technology Data Exchange (ETDEWEB)

During the ERA 1994 and 1996 Conference the authors made contributions on HV dividers and calibration equipment. The first part of this 1998 contribution describes the experiences with improvements of commercial dividers for application in current-zero measurements in circuit breaker testing. This application needs dividers with a very good flat step response. Commercial dividers can be improved by adequate design of the low voltage side components to decrease the rise time and to eliminate spurious oscillations. Second part of the contribution describes the specially designed capacitive dividers developed for Very Fast Transient Overvoltage (VFFO) measurements during switching operations of disconnectors in GIS. Three-phase tests are not mandatory according to IEC 1259 due problems of measurements. These can be overcome by built-in capacitive dividers and special digitising equipment with PET input stages. In such a way correct measurements of the trapped charges and VFTO us?? three-phase GIS can be guaranteed. (orig.)

Damstra, G.C.; Matyas, Z. [Eindhoven University of Technology (Netherlands)

2000-07-01

215

HIGH SPEED DOUGH DIVIDER WITH FERMENTATION GAS VENTS  

UK PubMed Central (United Kingdom)

A dough dividing machine which has a rotary divider head with a plurality of peripherally spaced, peripherally opening, dough receiving chambers for rapidly and accurately dividing dough into individual pieces; a dough supplying screw pump for supplying dough at a substantially constant pressure to at least one of the chambers at a dough supplying station past which the dough receiving chambers move when the divider head is rotated; and dough ejecting pistons successively movable in the chambers between radially inner, dough receiving positions, at the dough supplying station, and radially outer, dough ejecting positions at the dough discharging station to sequentially discharge the dough from the chambers in individual pieces.

GENDRON ROGER J; PLANT HARVEY E

216

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

International Nuclear Information System (INIS)

[en] 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

2012-01-01

217

[Design of broadband power divider in microwave hyperthermia system].  

Science.gov (United States)

In clinical application of microwave hyperthermia, multi-applicators are often simultaneously required to irradiate the tumor because of its large volume or its deep location. Power divider separates the input microwave energy into equal, or unequal, energy to each applicator. In this paper, the design procedure for the three-section transmission-line transformer based one-to-two equal-split Wilkinson power divider is introduced. By impedance analysis on equivalent scheme, the design parameter of power divider is provided, and by simulation and optimization on Ansoft HFSS, a microstrip structure Wilkinson power divider operating frequency 2. 45 GHz is given. Measurement test results from network analyzer show that it has 25% bandwidth and good isolation in output with this structure. Besides, it is characterized by small size and easy processing. This power divider suits microwave hyperthermia. PMID:21089651

Sun, Bing; Jiang, Guotai; Lu, Xiaofeng; Cao, Yi

2010-10-01

218

[Design of broadband power divider in microwave hyperthermia system].  

UK PubMed Central (United Kingdom)

In clinical application of microwave hyperthermia, multi-applicators are often simultaneously required to irradiate the tumor because of its large volume or its deep location. Power divider separates the input microwave energy into equal, or unequal, energy to each applicator. In this paper, the design procedure for the three-section transmission-line transformer based one-to-two equal-split Wilkinson power divider is introduced. By impedance analysis on equivalent scheme, the design parameter of power divider is provided, and by simulation and optimization on Ansoft HFSS, a microstrip structure Wilkinson power divider operating frequency 2. 45 GHz is given. Measurement test results from network analyzer show that it has 25% bandwidth and good isolation in output with this structure. Besides, it is characterized by small size and easy processing. This power divider suits microwave hyperthermia.

Sun B; Jiang G; Lu X; Cao Y

2010-10-01

219

Prospective memory: Effects of divided attention on spontaneous retrieval.  

UK PubMed Central (United Kingdom)

We examined the effects of divided attention on the spontaneous retrieval of a prospective memory intention. Participants performed an ongoing lexical decision task with an embedded prospective memory demand, and also performed a divided-attention task during some segments of lexical decision trials. In all experiments, monitoring was highly discouraged, and we observed no evidence that participants engaged monitoring processes. In Experiment 1, performing a moderately demanding divided-attention task (a digit detection task) did not affect prospective memory performance. In Experiment 2, performing a more challenging divided-attention task (random number generation) impaired prospective memory. Experiment 3 showed that this impairment was eliminated when the prospective memory cue was perceptually salient. Taken together, the results indicate that spontaneous retrieval is not automatic and that challenging divided-attention tasks interfere with spontaneous retrieval and not with the execution of a retrieved intention.

Harrison TL; Mullet HG; Whiffen KN; Ousterhout H; Einstein GO

2013-09-01

220

DESIGN NOTE: A novel method for the measurement of Young's modulus for thick-film resistor material by flexural testing of coated beams  

Science.gov (United States)

A method for measuring the Young's modulus of thick-film resistor material is presented. 96% alumina beams were coated with Heraeus 8241 resistor material and flexural tested in the three-point bend mode using a DMA 2980 Thermal Mechanical Analyser. Young's modulus was found to decrease linearly over the 173 K to 573 K temperature range. There was no evidence of non-elastic behaviour. Modulus results for the alumina substrate relate closely to published data. This method could be used to measure the modulus of a wide variety of thick-film coatings on substrates.

Fawcett, N.

1998-12-01

 
 
 
 
221

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

Directory of Open Access Journals (Sweden)

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.

Klein, Alexandra

2004-01-01

222

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

Directory of Open Access Journals (Sweden)

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.

Patrick C-H Soh; Yap Liang Yan; Tze San Ong; Boon Heng Teh

2012-01-01

223

Annan warns of 'content divide' between rich and poor  

CERN Multimedia

"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)

Dickson, D

2003-01-01

224

Divided Attention - Time spent reading food label (seconds)  

Science.gov (United States)

... Divided Attention - Time spent reading food label (seconds). Statistics. N. Valid. Missing. ... Time spent reading food label (seconds). Frequency. Percent ... More results from www.fda.gov/drugs/developmentapprovalprocess/developmentresources

225

Divided attention: An undesirable difficulty in memory retention.  

UK PubMed Central (United Kingdom)

How can we improve memory retention? A large body of research has suggested that difficulty encountered during learning, such as when practice sessions are distributed rather than massed, can enhance later memory performance (see R. A. Bjork & E. L. Bjork, 1992). Here, we investigated whether divided attention during retrieval practice can also constitute a desirable difficulty. Following two initial study phases and one test phase with Swahili-English word pairs (e.g., vuvi-snake), we manipulated whether items were tested again under full or divided attention. Two days later, participants were brought back for a final cued-recall test (e.g., vuvi-?). Across three experiments (combined N = 122), we found no evidence that dividing attention while practicing retrieval enhances memory retention. This finding raises the question of why many types of difficulty during practice do improve long-term retention, but dividing attention does not.

Gaspelin N; Ruthruff E; Pashler H

2013-05-01

226

Divided attention: An undesirable difficulty in memory retention.  

UK PubMed Central (United Kingdom)

How can we improve memory retention? A large body of research has suggested that difficulty encountered during learning, such as when practice sessions are distributed rather than massed, can enhance later memory performance (see R. A. Bjork & E. L. Bjork, 1992). Here, we investigated whether divided attention during retrieval practice can also constitute a desirable difficulty. Following two initial study phases and one test phase with Swahili-English word pairs (e.g., vuvi-snake), we manipulated whether items were tested again under full or divided attention. Two days later, participants were brought back for a final cued-recall test (e.g., vuvi-?). Across three experiments (combined N = 122), we found no evidence that dividing attention while practicing retrieval enhances memory retention. This finding raises the question of why many types of difficulty during practice do improve long-term retention, but dividing attention does not.

Gaspelin N; Ruthruff E; Pashler H

2013-10-01

227

Divided Attention – People using a prescription medicine to ...  

Science.gov (United States)

... Divided Attention – People using a prescription medicine to treat a mental condition should not take this product. Statistics. N. Valid. Missing. ... More results from www.fda.gov/drugs/developmentapprovalprocess/developmentresources

228

Evaluation of the divided attention condition during functional analyses.  

UK PubMed Central (United Kingdom)

A common condition included in most functional analyses (FAs) is the attention condition, in which the therapist ignores the client by engaging in a solitary activity (antecedent event) but delivers attention to the client contingent on problem behavior (consequent event). The divided attention condition is similar, except that the antecedent event consists of the therapist conversing with an adult confederate. We compared the typical and divided attention conditions to determine whether behavior in general (Study 1) and problem behavior in particular (Study 2) were more sensitive to one of the test conditions. Results showed that the divided attention condition resulted in faster acquisition or more efficient FA results for 2 of 9 subjects, suggesting that the divided attention condition could be considered a preferred condition when resources are available.

Fahmie TA; Iwata BA; Harper JM; Querim AC

2013-03-01

229

Divided Attention - A person using this drug should take no ...  

Science.gov (United States)

... Divided Attention - A person using this drug should take no more than 10 softgels in a 24-hour period. Statistics. N. Valid. Missing. ... More results from www.fda.gov/Drugs/DevelopmentApprovalProcess/DevelopmentResources

230

Process for producing finely divided powdery metal oxide compositions  

Energy Technology Data Exchange (ETDEWEB)

A process is described for producing a finely divided powdery metal oxide composition which comprises heating a particulate, sol-gel derived metal oxide composition, which contains agglomerates, and to which has been added an effective amount of a composition which decomposes at the temperature to which the metal oxide composition is heated to form a gas to break at least a portion of the agglomerates and to thereby yield the finely divided powdery composition.

Sherif, F.G.; Via, F.A.

1988-08-16

231

Divide-and-conquer generating functions. Part I. Elementary sequences  

CERN Document Server

Divide-and-conquer functions satisfy equations in F(z),F(z^2),F(z^4)... Their generated sequences are mainly used in computer science, and they were analyzed pragmatically, that is, now and then a sequence was picked out for scrutiny. By giving several classes of ordinary generating functions together with recurrences, we hope to help with the analysis of many such sequences, and try to classify a part of the divide-and-conquer sequence zoo.

Stephan, R

2003-01-01

232

Characterization of the first prototypes of Silicon Photomultipliers with bulk-integrated quench resistor fabricated at MPI semiconductor laboratory  

Science.gov (United States)

In this paper new results of the characterization of Silicon Photomultipliers (SiPMs) with bulk-integrated quench resistor will be presented. The novel detector concept was developed at the Max-Planck-Institute (MPI) semiconductor laboratory and allows a metal and polysilicon free entrance window which offers an improvement in photon detection efficiency (PDE). For electrical separation and suppression of optical cross talk (OCT) an insensitive area (gap) between neighboring cells is required. Based on simulations the first prototypes with devices of different combinations of cell size and gap were fabricated, providing the opportunity to study the influence of these parameters on the detector performance. First PDE measurements of the new detector are presented together with results of the influence of geometrical variations. Also an outlook on possible future developments of the concept with single cell read-out is given.

Jendrysik, Christian; Andri?ek, Ladislav; Liemann, Gerhard; Moser, Hans-Günther; Ninkovi?, Jelena; Richter, Rainer; Schopper, Florian

2013-08-01

233

Second Sound Measurement using SMD resistors to simulate Quench locations on the 704 MHZ Single-Cell Cavity at CERN  

CERN Multimedia

Oscillating Superleak Transducers (OSTs) containing flexible porous membranes are widely used to detect the so-called second sound temperature wave when a quench event occurs in a superconducting RF cavity. In principle, from the measured speed of this wave and the travel time between the quench event and several OSTs, the location of the quench sites can be derived by triangulation. Second sound behaviour has been simulated through different surface mount (SMD) resistors setups on a Superconducting Proton Linac (SPL) test cavity, to help understanding the underlying physics and improve quench localisation. Experiments are described that have been conducted to search for explanation of heat transfer during cavity quench that causes contradictory triangulation results.

Liao, K; Ciapala, E; Junginger, T; Weingarten, W

2012-01-01

234

High-performance and low-power rewritable SiOx 1 kbit one diode-one resistor crossbar memory array.  

UK PubMed Central (United Kingdom)

An entire 1-kilobit crossbar device based upon SiOx resistive memories with integrated diodes has been made. The SiOx -based one diode-one resistor device system has promise to satisfy the prerequisite conditions for next generation non-volatile memory applications.

Wang G; Lauchner AC; Lin J; Natelson D; Palem KV; Tour JM

2013-09-01

235

Divided manifold tee joint for germfree ovum aspiration needle  

UK PubMed Central (United Kingdom)

The invention relates to a divided manifold tee joint for a germfree ovum aspiration needle. Three ports of the divided manifold tee joint for the germfree ovum aspiration needle are respectively communicated with the connection end (1) of a puncture needle of which the end is provided with an ultrasound echo area, a collection end (2) communicated with a vacuum suction device, and an infusion end (3) communicated with a low-pressure infusion device. The invention is characterized in that one end of the puncture needle is connected with the divided manifold tee joint and is communicated with the low-pressure infusion device by the bifurcation end of a handle, the inner chamber (4) of the divided manifold tee joint is provided with a chamber body which is partial to an ellipse, the diameter of the joint of the puncture needle end thereof ranges from 0.9 to 1.7mm, and the diameter of the joint of the inner chamber of the divided manifold tee joint on the collection end and the infusion device end thereof ranges from 0.8 to 1.0mm. The divided manifold tee joint for the germfree ovum aspiration needle can enable the diameter of the needle tube to be smaller and causes less wound to the ovary, and by adopting an electromechanical interlocks, simple, reliable and continuous operation on processes of ovum flushing and suction can be maintained and the divided manifold tee joint endues the germfree ovum aspiration needle with the functions of a single-lumen needle and a double-lumen needle.

WEI LOU

236

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

UK PubMed Central (United Kingdom)

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.

Lin CH; Lee TT

2010-02-01

237

Structure of divided combustion chamber for diesel engine  

Energy Technology Data Exchange (ETDEWEB)

A structure is described defining a divided combustion chamber of a diesel engine consisting of: an upper ceramic member having a substantially hemispherical head and a lower ceramic member having an injection port, the lower ceramic member meeting with the upper ceramic member at an interface to form the divided combustion chamber therein, the upper ceramic member including at least one through hole extending from an outer surface thereof to an inside surface of the divided combustion chamber and at least one structural feature selected from the group consisting of a cut and a slit formed in a straight plane on at least the outer surface and extending from at least one through hole to another at least one through hole or to the interface.

Morita, T.; Wakasa; Ogawa, Y.; Ogasawara, T.

1986-03-25

238

Process for producing finely divided limestone for sulfur oxide removal  

Energy Technology Data Exchange (ETDEWEB)

A dry flue gas desulfurization process is described comprising: (a) dispersing an aqueous media containing finely divided calcium carbonate particulates having a weight average diameter of 10 microns or less in a gas stream containing sulfur oxides; (b) passing the gas stream containing the calcium carbonate particulates to a particle separation zone; and (c) recovering the calcium carbonate particulates from the gas stream substantially free of sulfur oxides, the aqueous media containing finely divided calcium carbonate particulates being produced by a process comprising the steps of: (i) forming a slurry of calcium carbonate in an aqueous media; (ii) adding carbon dioxide from an external source to the slurry; and (iii) abrasively grinding the calcium carbonate in the slurry in the presence of the carbon dioxide to produce the finely divided calcium carbonate particulates.

Veltman, P.L.

1987-12-15

239

Analysis and Simulation of a Photonic Crystal Power Divider  

Directory of Open Access Journals (Sweden)

Full Text Available In this research, the properties of a power divider that composed of two dimensional (2-D) Photonic Crystals (PC) have been analyzed. There is a large photonic band gap in transmission spectrum of the 2-D photonic crystal and by introducing a defect in the structure, some modes appear in it and propagate in the line defect waveguide. The PC power divider consists of a y-shaped line defect. The defect can be created by changing the size or removing the triangular PC defect rods. We have used an effective numerical method based on the Finite-Difference Time-Domain (FDTD) scheme to compute the evolution of the electric and magnetic fields in the structure. We have demonstrated the electric field evolution and calculated the insertion loss, isolation and coupling factors of the PC power divider.

N. Nozhat; N. Granpayeh

2007-01-01

240

Magneto-optical photonic crystal 1 × 3 switchable power divider  

Science.gov (United States)

Optical power splitter is an important building element in the photonic systems. Here, a 1 × 3 power divider using magneto-optical photonic crystal is proposed. The mechanism of operation is based on spatial field distribution, the mode matching of the fields and the effect of gyrotropy. It has a wide branching angle and the input power can either be switched completely to one of the output ports or divided equally between the three output ports by using an external magneto-static bias signal. A very good power transmission between the input and the output ports is observed.

Esmaieli, Ali; Ghayour, Rahim

2012-01-01

 
 
 
 
241

Robust state estimation using desensitized Divided Difference Filter.  

UK PubMed Central (United Kingdom)

This paper develops a robust divided difference filtering approach based on the concept of Desensitized Kalman Filtering. The filters are formulated using a minimum variance cost function, augmented with a penalty function consisting of a weighted norm of the state sensitivities. Solutions are provided for first and second-order Divided Difference Filters. The resulting filters are non-minimum variance but exhibit reduced sensitivity to deviations in the assumed plant model parameters. The proposed algorithms are demonstrated using Monte Carlo simulation techniques for an induction motor state estimation problem with parameter uncertainties.

Karlgaard CD; Shen H

2013-09-01

242

Robust state estimation using desensitized Divided Difference Filter.  

Science.gov (United States)

This paper develops a robust divided difference filtering approach based on the concept of Desensitized Kalman Filtering. The filters are formulated using a minimum variance cost function, augmented with a penalty function consisting of a weighted norm of the state sensitivities. Solutions are provided for first and second-order Divided Difference Filters. The resulting filters are non-minimum variance but exhibit reduced sensitivity to deviations in the assumed plant model parameters. The proposed algorithms are demonstrated using Monte Carlo simulation techniques for an induction motor state estimation problem with parameter uncertainties. PMID:23721743

Karlgaard, Christopher D; Shen, Haijun

2013-05-28

243

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

1995-01-01

244

Construction and Evaluation of Thin Film Beam Dividers.  

Science.gov (United States)

Available commercial beam dividers were not of adequate quality for diverting some laser power into a camera for the purpose of recording the power density distribution of an intense laser beam. A method was developed for constructing the required beam di...

L. J. Vande Kieft E. A. Murray W. M. Frey P. W. Yunker

1969-01-01

245

Peculiarities of the Digital Divide in Sub-Saharan Africa  

Science.gov (United States)

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…

Mutula, Stephen M.

2005-01-01

246

Closing the Digital Divide: Evaluation of the World Links Program  

Science.gov (United States)

In response to this digital divide between developed and developing countries in their use of computers to prepare students for the global economy, the World Bank and, subsequently, the World Links organization provided schools in developing countries with networked computers and training that supports integration of ICT into teaching. This…

Kozma, Robert; McGhee, Ray; Quellmalz, Edys; Zalles, Dan

2004-01-01

247

Research Highlights. Strengths and Needs of Divided Families.  

Science.gov (United States)

Describes a qualitative research study of children from divided families and analyzes findings in terms of family contexts, children's resiliency, and needs. Suggests strategies for professionals including recognition of developmental capacity within family circumstances, interactive systems, communication patterns and areas of stress. Includes…

Stringer-Seibold, Traci; And Others

1996-01-01

248

Dividing in epithelia: cells let loose during cytokinesis.  

UK PubMed Central (United Kingdom)

Epithelia must maintain barrier function-protecting interior tissues from a variable external environment-even while their cells divide. In the previous issue of Developmental Cell, Guillot and Lecuit (2013), Founounou et al. (2013), and Herszterg et al. (2013) present complementary findings on the regulation of adhesion and its impact on cell division.

Bourdages KG; Maddox AS

2013-02-01

249

Water hammer  

International Nuclear Information System (INIS)

[en] The overall NRC program for the resolution of the water hammer issue is divided into four tasks: water hammer summary reports; revision of CP and OL review procedures; water hammer positions for operating reactors; and water hammer safety studies

1978-10-25

250

Simple automatic water-supplying method of chicken-raising automatic water feeding system  

UK PubMed Central (United Kingdom)

The invention discloses a method of automatically supplying water for a water supply tank of an automatic drinking system for chicken. On the basis of manual control, a two-way thyristor is additionally arranged to control an AC contactor the anode of the two-way thyristor is connected with a control pole through a current limiting resistor the control pole is connected with an upper water level electrode in the water supply tank the upper water level electrode is connected with a middle water level electrode through a normally closed contact of the AC contactor a lower water level electrode is connected with the cathode of the two-way thyristor when the water level of the water supply tank submerges the upper water level electrode, the cathode of the two-way thyristor is short-circuited with the control pole so as to cut off the power supply when the power voltage is at the negative semicircle, then the AC contactor is resetted. The upper water level electrode is communicated with the middle water level electrode when the water level drops below the middle water level electrode, the current goes through the current limiting resistor to the control pole of the two-way thyristor and triggers the thyristor then the AC contactor is closed, the middle water level is disconnected with the upper water level, and a water pump of a motor supplements water for the water supply tank. The process is repeated.

ZHAOSHENG YANG; YIMING YANG

251

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

Energy Technology Data Exchange (ETDEWEB)

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.

Bouamrane, R [LEPM, Departement de Physique, USTO-MB, BP 1505 El M' Naouer, Oran 31000 (Algeria); Almond, D P [Department of Engineering and Applied Science, University of Bath, Bath BA2 7AY (United Kingdom)

2003-06-25

252

Interaction of RuO2 and Lead-Silicate Glass in Thick-Film Resistors  

Directory of Open Access Journals (Sweden)

Full Text Available Results of investigation of X-ray diffraction, infrared and optical spectra of powders of the ruthenium dioxide, lead-silicate glass as well as their mixture before and after sintering are reported. Sintering conditions typical for thick film resistors were used. Intensity of main lines of RuO2 in X-ray diffraction patterns of sintered mixtures decreases and they slightly shift towards small angles. No new reflexes appear in these patterns. Absorbance of RuO2 in the range of 2.5-100 ?m is proportional to and featureless. Infrared spectrum of lead-silicate glass has absorption bands of [SiO4]4- tetrahedra and Pb-O bonds only. Optical spectrum of RuO2 has wide absorption bands at 950 and 370 nm. Spectra of the mixture of RuO2 and glass powders before and after sintering are different indicating that there is interaction between them during the sintering process. Concentration of free charge carriers estimated from the optical spectra is about 1021 cm-3.

Gulmurza Abdurakhmanov; Gulbahor S. Vakhidova; Lutfullo X. Tursunov

2011-01-01

253

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

CERN Multimedia

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.

Khan, Sameen Ahmed

2010-01-01

254

Effects of installed system dumping resistors on stability of open cycle disk type MHD generator connected to power transmission line  

Energy Technology Data Exchange (ETDEWEB)

This study is performed as part of the wide research on large scale coal fired MHD generation systems. Faults in the power transmission line give remarkable fluctuations to the MHD generator and to the transmission network. Then, it is required to take countermeasures for stable operation of the generation system. The fluctuations do not converge to a stable state after cutting off the fault line in the transmission line because the commutation failure occurs in the inverter system after the line faults. The effects of installed system dumping resistors (SDR) on the stability of an open cycle disk type MHD generator connected to power transmission lines are numerically studied. Usually the AC SDR is installed in the AC primary grid of the transmission line for system stability. The SDR is used to absorb the output energy of the synchronous generator and to get stability of the power transmission system when faults occur in the transmission line. In this paper, The authors propose to install the SDR in the DC lines between the MHD generator and the primary side of connected line commutated inverters. It is shown that the SDR is effective for system stability by a. time dependent numerical analysis. This study makes it clear that switching on the applied SDR using the thyristor switches in addition to cutting off the faulted transmission lines is effective to remove the fluctuations of the MHD generation system.

Hayanose, N.; Inui, Y.; Ishikawa, M. [Kobe City College of Technology, Kobe (Japan). Dept. of Electrical Engineering

2001-07-01

255

Handheld Computers: No Child Left Behind's (NCLB's) Digital Divide Equalizers?  

Directory of Open Access Journals (Sweden)

Full Text Available The technology goals relating to The No Child Left Behind (NCLB) Act of 2001 recommend that teachers provide equitable learning opportunities that optimize learning and prepare students to perform efficiently and effectively on standardized tests. Handheld computers can be very useful classroom management tools for providing technological equity and bridging the digital divide. As part of an Ohio Board of Regents Technology initiative, university teacher educators were trained in the use of handheld computers. The participants discussed and/or demonstrated how the handheld computer software, the scientific probes on board, the cameras, and portable keyboards can be used with their preservice teachers to acquaint them with ways of bridging the digital divide.

Doris G. Johnson

2005-01-01

256

From Laptops to Competences: Bridging the Digital Divide in Education  

Directory of Open Access Journals (Sweden)

Full Text Available Most of the existing literature that deals with the digital divide in the educational system focuses either on schools or universities, but rarely do we see a vertical approach where the system is considered as a whole. In this paper we relate initiatives that aim to bridge the digital divide in the current situation in higher education. We discuss why policies that focus on infrastructures (e.g. laptops) are not the answer, as they mostly leave digital competences unattended, leading to (or not helping to amend) the digital void in universities in matters of skills. We end by proposing a general framework to define digital skills so that they are included in syllabuses at all stages of the educational path.

Ismael Peña-López

2010-01-01

257

Religion & Public Life: A Faith-Based Partisan Divide  

Science.gov (United States)

There was a great deal of discussion during the 2004 US presidential election about the so-called "faith-based" partisan divide. This insightful publication from the Pew Forum on Religion & Public Life takes a closer look at this divide in its 18-pages and provides a number of observations. The report begins by noting that Americans who regularly attend worship services and hold traditional religious views increasingly vote Republican, while those who are less connected to religious institutions tend to vote Democratic. Drawing on a number of polls and other surveys, the report also looks at other galvanizing issues such as opposition to gay marriage and attitudes towards stem cell research. The report also offers some interesting tables that look at how persons holding a variety of religious beliefs feel about the role of government and corporate welfare.

258

The Multicultural Pavillion: EdTech & Digital Divide  

Science.gov (United States)

The Multicultural Pavillion is part of EdChange, a website is founded and maintained by Paul C. Gorski, Ph.D., which provides "resources and dialogue for equity in education." This section on Ed Tech & Digital Divide offers online resources and articles on the digital divide and multicultural e-learning. Gorksi has also posted a 28-page report that combines various conference presentations, articles, and research he has done over the past three years on Multicultural Education and the Internet: Tools, Resources, and Commentary. Other sections of the Multicultural Pavillion offer listservs, historical documents, news updates, awareness activities, a poetry journal, movie reviews, songs for initiating multicultural dialogue, a working definition of multicultural education, and other resources on multicultural education and teacher action research.

259

A Novel Nanometric Reversible Signed Divider with Overflow Checking Capability  

Directory of Open Access Journals (Sweden)

Full Text Available One of the best approaches for designing future computers is that we use reversible logic. Reversible logic circuits have lower power consumption than the common circuits, used in computers nowadays. In this study we propose a new reversible division circuit. This reversible division circuit is signed divider and has an overflow checking capability. Among the designed and proposed reversible division circuits, our proposed division circuit is the first reversible signed divider with overflow checking capability which has been designed. In this circuit we use some reversible components like reversible parallel adder, reversible left-shift register, reversible multiplexer, reversible n-bit register and reversible n-bit register with parallel load line. In this paper all the scales are in the nanometric area.

Faraz Dastan; Majid Haghparast

2012-01-01

260

Regions of continuous rectification in systems divided into distillation regions  

Energy Technology Data Exchange (ETDEWEB)

The authors present the mechanisms of formation of regions of continuous clear rectification in three-component azeotropic systems of any complexity divided into distillation regions. The limitations of the process for all types of clear rectification have been determined. They have noted the phenomena of intersection of sets in which the rectification process develops as a function of the type of the specified separation. The phenomenon of transfer through the separating manifold of distillation has been pointed out.

Balashov, M.I.; Grishunin, A.V.; Serafimov, L.A.

1985-07-01

 
 
 
 
261

THE DIGITAL DIVIDE: ICT DEVELOPMENT INDICES IN MEXICO  

Directory of Open Access Journals (Sweden)

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.

Edgar TELLO-LEAL; Claudia M. SOSA-REYNA; Diego A. TELLO-LEAL

2012-01-01

262

Water  

Energy Technology Data Exchange (ETDEWEB)

This book considers the present knowledge of liquid water, its physical properties and how these give rise to a unique structure, its influence on the interactions between solutes, its role in maintaining biologically active structures, its involvement in chemical reactions and the problems posed by its management and in providing sufficient amounts of water of adequate quality. Topics covered include: occurrence, importance and physical properties; the place of water in the general classification of liquids; isotopic composition; the structure of the water molecule and the nature of the hydrogen bond in water: ice-its structure and dynamics; the structure of liquid water; the dynamic properties of liquid water; towards a molecular description of water; aqueous solutions of simple molecules; aqueous solutions of electrolytes; the role of water in the stabilisation of biologically significant structures; reactions in aqueous solutions; water in the environment-quality, availability and exploitation, and future prospects.

Franks, F.

1984-01-01

263

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

Directory of Open Access Journals (Sweden)

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.

Jason Smith

2009-01-01

264

Power Factor Correction in Cycle Control with Divided Output Capacitors  

Science.gov (United States)

A power factor correction scheme using a cycle-control is proposed without switching devices, where output voltage can be much reduced. A certain application requires such control like significantly lowering the output voltage. In the proposed method, the output capacitor is divided into two parts, in which the input current waveform becomes balanced one. Hence, the harmonic characteristics can be much improved, where the lower order harmonics, such as the fifth and seventh orders are sufficiently reduced. The results are confirmed by the theoretical and experimental implementations.

Yamamoto, Isamu; Matsui, Keiju; Mori, Hideki; Kojima, Hiroo; Ando, Kenji; Fujimatsu, Ichiro; Watanabe, Yosikazu

265

Femtosecond fiber chirped- and divided-pulse amplification system.  

UK PubMed Central (United Kingdom)

We implement both chirped pulse amplification and divided pulse amplification in the same femtosecond fiber amplifier setup. This scheme allows an equivalent stretched pulse duration of 2.4 ns in a compact tabletop system. The generation of 77 W of compressed average power at 4.8 MHz, together with 320 fs and 430 ?J pulses at a repetition rate of 96 kHz, is demonstrated using a distributed mode-filtering, rod-type, ytterbium-doped fiber. Limitations in the temporal recombining efficiency due to gain saturation inside the fiber amplifier are identified.

Zaouter Y; Guichard F; Daniault L; Hanna M; Morin F; Hönninger C; Mottay E; Druon F; Georges P

2013-01-01

266

A divide-and-conquer algorithm for identifying strongly connectedcomponents  

Energy Technology Data Exchange (ETDEWEB)

Strongly connected components of a directed graph can be found in an optimal linear time, by algorithms based on depth first search. Unfortunately, depth first search is difficult to parallelize. We describe two divide--and--conquer algorithms for this problem that have significantly greater potential for parallelization. We show the expected serial runtime of our simpler algorithm to be O(m log n), for a graph with n vertices and m edges. We then show that the second algorithm has O(mlog n) worst--case complexity.

Coppersmith, Don; Fleischer, Lisa; Hendrickson, Bruce; Pinar, Ali

2003-03-27

267

Informaticiens Sans Frontières. Helping to bridge the Digital Divide  

CERN Multimedia

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.

Josiane Uwantege

2009-01-01

268

Water wing plant pot  

UK PubMed Central (United Kingdom)

A plant pot has a main central portion having an opening providing access to a main planting area, and a pair of wings extending from the main central portion, namely a left wing and a right wing and a pair of dividers, namely a left divider and a right divider. The pair of dividers is inserted between the pair of wings and the main central portion. The pair of dividers is formed as sheets, and the pair of dividers is removable from a divider attachment area. A plurality of water openings are disposed on the pair of dividers, and the plurality of water openings allow water to pass between the main central portion and the pair of wings.

JUNG MAN-YOUNG

269

Proliferating parasites in dividing cells Kimmel's branching model revisited  

CERN Multimedia

We consider a branching model introduced by M. Kimmel for cell division with parasite infection. Cells contain proliferating parasites which are shared randomly between the two daughter cells when they divide. We determine the probability that the organism recovers, meaning that the asymptotic proprotion of contaminated cells vanishes. We study the tree of contaminated cells, give the asymptotic number of contaminated cells and the asymptotic proportions of contaminated cells with a given number of parasites. This depends on domains inherited from the behavior of branching processes in random environment (BPRE) and given by the bivariate value of the means of parasite offsprings. In one of these domains, the convergence of proportions holds in probability, the limit is deterministic and given by the Yaglom quasistationary distribution. Moreover we get an interpretation of the limit of the Q-process as the size-biased quasistationary distribution.

Bansaye, V

2007-01-01

270

Dividing Discipline : Structures of Communication in International Relations  

DEFF Research Database (Denmark)

International Relations (IR) has cultivated an image as a discipline with strong divisions along paradigmatic, methodological, metatheoretical, geographical, and other lines. This article questions that image analyzing the latent structures of communication in IR. It uses citation data from more than 20,000 articles published in 59 IR journals to construct a network among IR journals and finds a discipline with a center consisting of pedigreed IR journals, albeit closely related to political science. Divisions are identifiable as specialty areas that form clusters of specialized journals along the periphery of the network—security studies and international political economy in particular—but communication is also divided along the lines of geography and policy/theory. The article concludes that divisions notwithstanding, IR communication remains centered around American, general, and theoretical IR journals and that to practice this particular kind of communication is an important dimension of being an IR scholar.

Kristensen, Peter Marcus

2012-01-01

271

Bayesian Blocks Divide and Conquer, MCMC, and Cell Coalescence Approaches  

CERN Document Server

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.

Scargle, J D

2000-01-01

272

Bridging the Digital Divide through Educational Initiatives: Problems and Solutions  

Directory of Open Access Journals (Sweden)

Full Text Available Being on the wrong side of the digital divide limits the life chances of the socially excluded, who have had neither the wherewithal nor the opportunity to obtain highly paid, skilled positions in IT. Irish policy makers see education as the solution to this problem. However, provid-ing institutional support for the socially disadvantaged who wish to avail of third level education in IT poses significant challenges. This paper describes these problems and explains how they were overcome in implementing an undergraduate university programme called the Diploma in Applied Business Computing. This targeted initiative was an unqualified success in that it achieved its primary objectives--academic and social. However, what made it so was the commitment of concerned stakeholders, from members of the executive steering committee who developed and implemented the course, to the lecturers who delivered it, the companies who supported it, and the students who participated in it.

Tom Butler

2002-01-01

273

Paired electrolysis of aldoses in a divided flow cell  

Energy Technology Data Exchange (ETDEWEB)

Simultaneous anodic oxidation and cathodic reduction of aldoses in a divided flow cell were studied. The stream of the anolyte was an aqueous solution containing D-glucose, sodium bromide, and sodium bicarbonate. The stream of the catholyte was also an aqueous solution containing xylose and sodium sulfite. The factors which affected both the anodic and cathodic reactions were studied. The results indicate that the flow rates and temperatures of the anolyte and the catholyte, concentrations of the aldoses, pH values and the material of electrodes significantly affected both anodic and cathodic yields. The selectivities of gluconic acid in the anode and xylitol in the cathode were very high. The power consumption of paired electrolysis in the flow system was less than paired electrolysis in a batch system.

Chou, T.; Liaw, S.; Hwang, B.J.

1987-06-01

274

Older people and digital disengagement: a fourth digital divide?  

UK PubMed Central (United Kingdom)

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.

Olphert W; Damodaran L

2013-01-01

275

Older people and digital disengagement: a fourth digital divide?  

Science.gov (United States)

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

Olphert, Wendy; Damodaran, Leela

2013-08-20

276

Older People and Digital Disengagement: A Fourth Digital Divide?  

UK PubMed Central (United Kingdom)

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.

Olphert W; Damodaran L

2013-08-01

277

Water  

Energy Technology Data Exchange (ETDEWEB)

The translation of the Environmental Legislation in Finland has been published in a series of booklets, the third publication in this series is the Water legislation. The Finnish Water Act was passed in 1961 and has since been revised several times. The most recent substantial changes were made in 1987 and were specifically designed to take account of water pollution control. Certain minor amendments to the Water Act are currently in preparation. Harmonization of Finnish legislation with EC legislation in accordance with the EEA agreement will take care that our advanced level of water protection is maintained The basic principles of the Finnish water legislation mean that polluting, altering and damming water bodies is strictly controlled. Any activities likely to damage the water bodies are subject to permit. Applications for permits are processed individually, and permits are granted on terms laid down separately case by case. The permit authority is the relevant water court or, in certain circumstances, local environmental protection committee. The environmental legislation in general is changing over to an integrated permit system, but in the case of water matters, individual processing by the water courts will remain

1992-01-01

278

Grain size effects on H{sub 2} gas sensitivity of thick film resistor using SnO{sub 2} nanoparticles  

Energy Technology Data Exchange (ETDEWEB)

The effect of ppm level H{sub 2} on the d.c. resistance of SnO{sub 2} thick film planar resistor with SnO{sub 2} particle size variation ({proportional_to}20 to 50 nm) is reported. SnO{sub 2} nanoparticles were synthesized using the sol-gel method. The films were prepared using standard screen printing technology. The SnO{sub 2} crystallite size, D, is varied in the range of 20-50 nm and sensitivity for H{sub 2} is found to increase steeply as D decreases. (orig.)

Ansari, S.G. [Poona Univ., Pune (India). Dept. of Physics; Boroojerdian, P. [Poona Univ., Pune (India). Dept. of Physics; Sainkar, S.R. [National Chemical Laboratory, Pashan Road, Pune 411008 (India); Karekar, R.N. [Poona Univ., Pune (India). Dept. of Physics; Aiyer, R.C. [Poona Univ., Pune (India). Dept. of Physics; Kulkarni, S.K. [Poona Univ., Pune (India). Dept. of Physics

1997-02-28

279

BRIDGING THE KNOWLEDGE DIVIDE Educational Technology for Development  

Directory of Open Access Journals (Sweden)

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 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 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

Reviewed by Ozlem OZAN,

2009-01-01

280

Multidimensional Divide-and-Conquer and Weighted Digital Sums  

CERN Document Server

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

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

2010-01-01

 
 
 
 
281

Divided attention limits perception of 3-D object shapes.  

UK PubMed Central (United Kingdom)

Can one perceive multiple object shapes at once? We tested two benchmark models of object shape perception under divided attention: an unlimited-capacity and a fixed-capacity model. Under unlimited-capacity models, shapes are analyzed independently and in parallel. Under fixed-capacity models, shapes are processed at a fixed rate (as in a serial model). To distinguish these models, we compared conditions in which observers were presented with simultaneous or sequential presentations of a fixed number of objects (The extended simultaneous-sequential method: Scharff, Palmer, & Moore, 2011a, 2011b). We used novel physical objects as stimuli, minimizing the role of semantic categorization in the task. Observers searched for a specific object among similar objects. We ensured that non-shape stimulus properties such as color and texture could not be used to complete the task. Unpredictable viewing angles were used to preclude image-matching strategies. The results rejected unlimited-capacity models for object shape perception and were consistent with the predictions of a fixed-capacity model. In contrast, a task that required observers to recognize 2-D shapes with predictable viewing angles yielded an unlimited capacity result. Further experiments ruled out alternative explanations for the capacity limit, leading us to conclude that there is a fixed-capacity limit on the ability to perceive 3-D object shapes.

Scharff A; Palmer J; Moore CM

2013-01-01

282

Quadrature Hartley VCO and Injection-Locked Frequency Divider  

Science.gov (United States)

Novel low phase noise quadrature voltage-controlled oscillator (QVCO) and quadrature injection locked frequency divider (QILFD) with two coupled Hartley VCOs are proposed and implemented using the standard TSMC 0.18?m CMOS 1P6M process. The QVCO employs pMOS as the core to reduce the up-conversion of low-frequency device noise to RF phase noise. It uses super-harmonic coupling technique to couple two differential Hartley VCOs and four small-size coupling transistors to set the directivity of quadrature output phases. At the 1.7V supply voltage, the output phase noise of the QVCO is -124dBc/Hz at 1MHz offset frequency from the carrier frequency of 4.12GHz, and the figure of merit is -185dBc/Hz. At the supply voltage of 1.7V, the total power consumption is 13.1mW. At the supply voltage of 1.5V, the tuning range of the free-running QILFD is from 2.05GHz to 2.36GHz, about 310MHz, and the locking range of the ILFD is from 3.99 to 5.19GHz, about 1.20GHz, at the injection signal power of 0dBm.

Jang, Sheng-Lyang; Chang, Chia-Wei; Wu, Sheng-Chien; Lee, Chien-Feng; Tsai, Lin-Yen; Huang, Jhin-Fang

283

Symmetric polynomials and divided differences in formulas of intersection theory  

CERN Multimedia

The goal of the paper is two-fold. At first, we attempt to give a survey of some recent applications of symmetric polynomials and divided differences to intersection theory. We discuss: polynomials universally supported on degeneracy loci; some explicit formulas for the Chern and Segre classes of Schur bundles with applications to enumerative geometry; flag degeneracy loci; fundamental classes, diagonals and Gysin maps; intersection rings of G/P and formulas for isotropic degeneracy loci; numerically positive polynomials for ample vector bundles. Apart of surveyed results, the paper contains also some new results as well as some new proofs of earlier ones: how to compute the fundamental class of a subvariety from the class of the diagonal of the ambient space; how to compute the class of the relative diagonal using Gysin maps; a new formula for pushing forward Schur's Q- polynomials in Grassmannian bundles; a new formula for the total Chern class of a Schur bundle; another proof of Schubert's and Giambelli's ...

Pragacz, P

1996-01-01

284

Informaticiens Sans Frontieres: Helping to bridge the Digital Divide  

CERN Multimedia

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...

CERN. Geneva

2009-01-01

285

HIV-1 latency in actively dividing human T cell lines  

Directory of Open Access Journals (Sweden)

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 TNF? 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.

Jeeninga Rienk E; Westerhout Ellen M; van Gerven Marja L; Berkhout Ben

2008-01-01

286

Bridging the transatlantic climate divide. Final project paper  

Energy Technology Data Exchange (ETDEWEB)

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.

Kersten, W.C.; Zoeteman, B.C.J.

2005-10-15

287

Bridging the transatlantic climate divide. Final project paper. Appendices  

International Nuclear Information System (INIS)

[en] 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

2005-01-01

288

National Identity and Xenophobia in an Ethnically Divided Society  

Directory of Open Access Journals (Sweden)

Full Text Available Recent studies have suggested that national identity is empirically related to negative sentiments of individuals towards foreigners. This type of analysis has hitherto been based on the notion that xenophobia is shaped by the specific nature of national identity in a given society. Representing a stronger and more exclusive perception of national identity, ethnic national identity (compared with civic national identity) is expected in this line of research to result in less favourable perceptions of immigrants. In this paper we expand this approach by arguing that, in deeply divided societies, national identity itself may have different meanings among different social groups. Specifically, our analysis indicates that members of dominant ethnic groups ascribe higher importance to national identification than members of subordinate ethnic groups, and centre their perception of ethnic national identity on ancestral terms, while marginal ethnic groups tend to also associate this form of identity with affective and cultural elements. In addition, we propose a theoretical framework for the understanding of the relationship between national identity and xenophobia. In particular, we focus on the group threat model and the cultural affinity perspective, as both theories explain out-group hostility by focusing on group identity. Analysis of Israeli data from the ISSP module on national identity provides support primarily for the cultural affinity thesis, revealing that, in contrast to previous studies, ethnic national identity is negatively related to xenophobia among members of the Jewish ethnic group. This finding is discussed in terms of the distinctive features of Israeli society and its immigration context.

Noah Lewin-Epstein; Asaf Levanon

2005-01-01

289

A Divide-and-Conquer Approach to Commercial Territory Design/ Procedimiento divide y vencerás para el diseño de territorios comerciales  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish En este trabajo se presenta un procedimiento heurístico para el diseño de territorios comerciales. El procedimiento propuesto, basado en el paradigma dividir-y-vencer, consiste básicamente en un proceso de dicotomías sucesivas a partir de una instancia dada. Durante este proceso se resuelven una serie de subproblemas de programación cuadrática entera. Los resultados computacionales muestran que la heurística propuesta es una técnica de solución atractiva que perm (more) ite la obtención de soluciones óptimas locales para instancias grandes del problema, las cuales resultan intratables al intentar resolverlas a través de métodos exactos. Abstract in english A new heuristic procedure for a commercial territory design problem is introduced in this work. The proposed procedure is based on the divide-and-conquer paradigm and basically consists of a successive dichotomy process on a given large instance of the problem. During this process, a series of integer quadratic subproblems is solved. The obtained computational results have shown that the proposed heuristic is an attractive technique for obtaining locally optimal solutions for large instances which are intractable by using exact optimization methods.

Salazar-Aguilar, M. Angélica; González-Velarde, J. Luis; Ríos-Mercado, Roger Z.

2012-09-01

290

Bridging the divide between genomic science and indigenous peoples.  

Science.gov (United States)

The new science of genomics endeavors to chart the genomes of individuals around the world, with the dual goals of understanding the role genetic factors play in human health and solving problems of disease and disability. From the perspective of indigenous peoples and developing countries, the promises and perils of genomic science appear against a backdrop of global health disparity and political vulnerability. These conditions pose a dilemma for many communities when attempting to decide about participating in genomic research or any other biomedical research. Genomic research offers the possibility of improved technologies for managing the acute and chronic diseases that plague their members. Yet, the history of particularly biomedical research among people in indigenous and developing nations offers salient examples of unethical practice, misuse of data, and failed promises. This dilemma creates risks for communities who decide either to participate or not to participate in genomic science research. Some argue that the history of poor scientific practice justifies refusal to join genomic research projects. Others argue that disease poses such great threats to the well-being of people in indigenous communities and developing nations that not participating in genomic research risks irrevocable harm. Thus, some communities particularly among indigenous peoples have declined to participate as subjects in genomic research. At the same time, some communities have begun developing new guidelines, procedures, and practices for engaging with the scientific community that offer opportunities to bridge the gap between genomic science and indigenous and/or developing communities. Four new approaches warrant special attention and further support: consulting with local communities; negotiating the complexities of consent; training members of local communities in science and health care; and training scientists to work with indigenous communities. Implicit is a new definition of "rigorous scientific research," one that includes both community development and scientific progress as legitimate objectives of genomic research. Innovative translational research is needed to develop practical, mutually acceptable methods for crossing the divide between genomic researchers and indigenous communities. This may mean the difference between success and failure in genomic science, and in improving health for all peoples. PMID:20880250

Jacobs, Bette; Roffenbender, Jason; Collmann, Jeff; Cherry, Kate; Bitsói, LeManuel Lee; Bassett, Kim; Evans, Charles H

2010-01-01

291

A system for automatic regulation of the flow rate of the supply water in a steam generator  

Energy Technology Data Exchange (ETDEWEB)

To increase the statistical precision of a replenishment water flow rate stabilizer a nonlinear element is proposed, which is installed sequentially with the flow rate sensor. The nonlinear element is proposed to be made in the form of an RC-circuit and a threshold element switched in parallel to its resistor. Silicon diodes are used as the threshold element.

Bokhan, P.V.; Marinov, B.B.

1982-01-01

292

Liquid-liquid extraction: An adsorption isotherm at divided interface?  

International Nuclear Information System (INIS)

We show that liquid-liquid extraction can be described as the equilibrium between two pseudo-phases of ions: the hydrated state in the water phase and the solvation state when the ions are adsorbed on an organized interface. The extractant is considered as a potential surface where the ions can adsorb. Unlike phenomenological binding 'constants', ion extraction/stripping can be seen as the sum of Langmuir isotherms. The number of aggregated extractants in one reverse micelle in the solvent is at least equal to or higher than the number of extracting molecules complexed at a given instant to the ion to be extracted. Considering extraction equilibrium as a sum of isotherms corresponding to the different states of aggregation of extractant molecule in the solvent, the resulting constant is representative of both the efficiency of the extraction and the structure of the solution. This is a first step toward the development of predictive models for the apparent distribution coefficients. (authors)

2007-01-01

293

Transient development of stratification in a partially divided enclosure  

International Nuclear Information System (INIS)

In passive solar heating of buildings or in compartment fires, the authors are concerned with the development of thermal stratification when two rooms at different temperatures are connected by the opening of a door. They performed experiments and numerical calculations aimed at this application. The experiments consist of flow visualization and temperature measurements obtained when isolated halves of a tank containing water at two different temperatures are suddenly connected to allow flow between the zones. Two significant findings from this work are: 1) the presence of internal waves excited by the onset of flow through the doorway which have not normally been observed in past laboratory experiments, and 2) the equilibration time is found to be in general agreement with that predicted by a formula from a simple orifice model that they describe. Work is progressing on numerical simulations using two core stratification models connected by an orifice including entrainment in the neighborhood of the connection.

1987-01-01

294

Transient development of stratification in a partially divided enclosure  

Energy Technology Data Exchange (ETDEWEB)

In passive solar heating of buildings or in compartment fires, we are concerned with the development of thermal stratification when two rooms at different temperatures are connected by the opening of a door. We have performed experiments and numerical calculations aimed at this application. The experiments consists of flow visualization and temperature measurements obtained when isolated halves of a tank containing water at two different temperatures are suddenly connected to allow flow between the zones. Two significant findings from this work are: (1) the presence of internal waves excited by the onset of flow through the doorway which have not normally been observed in past laboratory experiments, and (2) the equilibration time is found to be in general agreement with that predicted by a formula from a simple orifice model that we describe. Work is progressing on numerical simulations using two core stratification models connected by an orifice including entrainment in the neighborhood of the connection. 27 refs., 5 figs., 1 tab.

Otis, D.R.; Jones, G.F.

1987-01-01

295

Dividing the common pond: regionalizing EU ocean governance.  

UK PubMed Central (United Kingdom)

EU ocean policies increasingly incorporate regional measures. Under the long standing Common Fisheries Policy, such measures aim at improving and reforming existing policy, either by taking into account region specific social or ecologic requirements or by establishing procedures and institutions to achieve a regional fit. By contrast, the EU's emerging integrated Marine Environmental Policy was designed to draw heavily on regional procedural and institutional mechanisms from the outset. The developing regional measures raise the question whether they contribute to improving institutional structures governing the use and conservation of EU waters. This article analyzes the existing and future regional measures of the two policies and their varying purposes and scopes. It develops a typology for categorizing the regional aspects and examines the effects of regional measures on EU institutions and the theoretical EU integration debate.

Maier N; Markus T

2013-02-01

296

Experimental study of phase separation in dividing two phase flow  

International Nuclear Information System (INIS)

[en] Experimental study of phase separation of air-water two phase bubbly, slug flow in the horizontal T-junction is carried out. The influences of the inlet mass quality X1, mass extraction rate G3/G1, and fraction of extracted liquid QL3/QL1 on phase separation characteristics are analyzed. For the first time, the authors have found and defined pulsating run effect by the visual experiments, which show that under certain conditions, the down stream flow of the T-junction has strangely affected the phase redistribution of the junction, and firstly point out that the downstream geometric condition is very important to the study of phase separation phenomenon of two-phase flow in a T-junction. This kind of phenomenon has many applications in the field of energy, power, petroleum and chemical industries, such as the loss of coolant accident (LOCA) caused by a small break in a horizontal coolant pipe in nuclear reactor, and the flip-flop effect in the natural gas transportation pipeline system, etc

1996-01-01

297

Package with Divider to Separate Contents, and Method of Filing the Package at High Speed  

UK PubMed Central (United Kingdom)

The present disclosure provides a divider for packaging applications. The divider can separate products in the package into a plurality of groups, and can also contain relevant information about the products, as is required in the case of packaging tampons. The present disclosure also provides a method of packaging a plurality of products, using the divider.

ROSSI WAYNE; WILLIAMSON MICHAEL; PREISNER PETER; DREWNOWSKI WOJTEK; STANLEY JOHN

298

Application of a Static Reactive Power Compensator (STATCOM) and a Dynamic Braking Resistor (DBR) for the stability enhancement of a large wind farm  

Energy Technology Data Exchange (ETDEWEB)

A control strategy to improve the stability of a large wind farm using a Static Reactive Power Compensator (STATCOM) and Dynamic Braking Resistor (DBR) is proposed and investigated. The STATCOM supplies the reactive power demand of the wind farm dynamically in order to maintain the network voltage. The DBR is controlled by Liapunov's stability criterion to absorb the active power of the wind farm during the network fault. The performance of the STATCOM and DBR, applied to a large wind farm (60MW), is studied in PSCAD/EMTDC. The simulation results show that effective control of the STATCOM and DBR together can enhance the stability of large wind farms. (author)

Wu, X.; Arulampalam, A.; Zhan, C.; Jenkins, N.

2003-03-01

299

Unipolar resistive switching behavior in Pt/HfO2/TiN device with inserting ZrO2 layer and its 1 diode-1 resistor characteristics  

Science.gov (United States)

Transition of resistive switching (RS) behavior from bipolar to unipolar is observed in Pt/ZrO2/HfO2/TiN device. Due to the lower oxygen vacancy concentration of the HfO2 layer, formation/rupture of the conducting filament is confined in the HfO2 layer. To fulfill one diode and one resistor (1D1R) structure, the electrical relation between the RS device and diode is investigated. A Pt/InZnO/CoO/Pt/TiN oxide diode is fabricated to provide enough forward current and large forward/reverse current ratio to achieve unipolar RS behavior. The 1D-1R structure with Pt/ZrO2/HfO2/TiN resistive random access memory shows robust retention and nondestructive readout property at 85 °C.

Lee, Dai-Ying; Tsai, Tsung-Ling; Tseng, Tseung-Yuen

2013-07-01

300

The experiment and analysis of tailoring VL and Ip with ZnO voltage-sensitive resistor on HT-6M  

International Nuclear Information System (INIS)

[en] In many small tokamak devices, the capacitor banks is used as a poloidal field power supply without chopper for the financial reason and the little difference between the magnitude of the plasma duration time and the chopper switching time. Thus, the voltage and the current waveforms must be formed by several phases of different LRC discharge waveforms. The variation of Ip, VL and other parameters is still large even in the plateau stage. The idea of plateau improved with ZnO varistor (voltage sensitive resistor) is presented in this paper. Also, the result of tailoring VL and Ip experiment on HT-6M tokamak is introduced. An improved tens millisecond plateau was achieved (?VL/VL

1991-01-01

 
 
 
 
301

Water watch  

Energy Technology Data Exchange (ETDEWEB)

In this issue of Water Watch, a summary of precipitation, drought, and streamflow conditions during the summer is presented. In addition, short-term streamflow forecasts (through October) for each region are given. For purposes of reporting, the US is divided into six regions. The data presented can be used to observe how weather conditions affected hydro generation in July.

1991-10-01

302

Dividing Arizona  

Science.gov (United States)

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…

Finkel, Ed

2010-01-01

303

Process for recovering fine coal particles from slurry of finely divided coal  

Energy Technology Data Exchange (ETDEWEB)

Fine coal particles are recovered from a slurry of finely divided coal by mixing coarsely divided coal and a binder together to cause the binder to adhere to the surfaces of the coarsely divided coal pieces, mixing the slurry with the coal pieces having the binder adhered thereto to cause fine coal particles to adhere to the binder over the surfaces of the coal pieces serving as nuclei and thereby form agglomerates, and separating the agglomerates from the remaining slurry portion to recover the fine coal particles along with the coarsely divided coal and the binder.

Harada, K.; Ogino, E.; Yoshii, N.

1982-08-24

304

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

Directory of Open Access Journals (Sweden)

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.

Preeti Dubey; JeevanJyoti; Devanand

2011-01-01

305

Measuring current distribution in parallel networks using a divided Rogov region  

Energy Technology Data Exchange (ETDEWEB)

By using a divided Rogov region, the possibility of determining currents in parallel networks located in areas which are inaccessable for direct hookups by normal test equipment (such as in multi-channel gas-discharge devices and spark gaps) is demonstrated. Calculation formulae are derived, and a concept of the resolution of a divided Rogov area is given.

Grigorev, I.N.

1982-01-01

306

From Digital Divides to Digital Inequality -- The Emerging Digital Inequality in the Norwegian Unitarian School  

Science.gov (United States)

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…

Krumsvik, Rune J.

2008-01-01

307

Weather sensor based on temperature-dependent resistors using ''multi-signal''-analysis; ''Multisignal''-Sensorik am Beispiel von Witterungssensoren auf der Basis temperaturabhaengiger Widerstaende  

Energy Technology Data Exchange (ETDEWEB)

Uncomplex weather sensors based on PTC thermistors and Pt100 thermal resistors are described to be used e.g. for automated opening of windows. The performance needed is achieved through so-called ''multi-signal'' processing. A set-up consisting of three thermistors is used to obtain the wind direction and velocity using the result of an optimization procedure which constitutes a quality measure of the sensor measurements, giving a tool to on-line monitor the sensor's state. With periodic excitation of a Pt100 thermal resistor the wind velocity as well as rain, snow, ice, and temperature are derived from the thermal impedance with sufficient accuracy and reliability. During operation, the parameters of the sensor model are observed, allowing drifts due to soiling or ageing to be detected and compensated. (orig.)

Ruser, H.; Horn, M. [Univ. der Bundeswehr Muenchen, Neubiberg (Germany). Inst. fuer Mess- und Automatisierungstechnik

2006-08-15

308

Host factor SAMHD1 restricts DNA viruses in non-dividing myeloid cells.  

Science.gov (United States)

SAMHD1 is a newly identified anti-HIV host factor that has a dNTP triphosphohydrolase activity and depletes intracellular dNTP pools in non-dividing myeloid cells. Since DNA viruses utilize cellular dNTPs, we investigated whether SAMHD1 limits the replication of DNA viruses in non-dividing myeloid target cells. Indeed, two double stranded DNA viruses, vaccinia and herpes simplex virus type 1, are subject to SAMHD1 restriction in non-dividing target cells in a dNTP dependent manner. Using a thymidine kinase deficient strain of vaccinia virus, we demonstrate a greater restriction of viral replication in non-dividing cells expressing SAMHD1. Therefore, this study suggests that SAMHD1 is a potential innate anti-viral player that suppresses the replication of a wide range of DNA viruses, as well as retroviruses, which infect non-dividing myeloid cells. PMID:23825958

Hollenbaugh, Joseph A; Gee, Peter; Baker, Jonathon; Daly, Michele B; Amie, Sarah M; Tate, Jessica; Kasai, Natsumi; Kanemura, Yuka; Kim, Dong-Hyun; Ward, Brian M; Koyanagi, Yoshio; Kim, Baek

2013-06-27

309

Host factor SAMHD1 restricts DNA viruses in non-dividing myeloid cells.  

UK PubMed Central (United Kingdom)

SAMHD1 is a newly identified anti-HIV host factor that has a dNTP triphosphohydrolase activity and depletes intracellular dNTP pools in non-dividing myeloid cells. Since DNA viruses utilize cellular dNTPs, we investigated whether SAMHD1 limits the replication of DNA viruses in non-dividing myeloid target cells. Indeed, two double stranded DNA viruses, vaccinia and herpes simplex virus type 1, are subject to SAMHD1 restriction in non-dividing target cells in a dNTP dependent manner. Using a thymidine kinase deficient strain of vaccinia virus, we demonstrate a greater restriction of viral replication in non-dividing cells expressing SAMHD1. Therefore, this study suggests that SAMHD1 is a potential innate anti-viral player that suppresses the replication of a wide range of DNA viruses, as well as retroviruses, which infect non-dividing myeloid cells.

Hollenbaugh JA; Gee P; Baker J; Daly MB; Amie SM; Tate J; Kasai N; Kanemura Y; Kim DH; Ward BM; Koyanagi Y; Kim B

2013-06-01

310

Conduction mechanisms and 1/f noise in thick-film resistors with Pb/sub 3/Rh/sub 7/O/sub 15/ and Pb/sub 2/Ru/sub 2/O/sub 7/  

Energy Technology Data Exchange (ETDEWEB)

Thick-film resistors with Pb/sub 3/Rh/sub 7/0/sub 15/ and Pb/sub 2/Ru/sub 2/0/sub 7/ 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.

de Jeu, W.H.; Geuskens, R.W.J.; Pike, G.E.

1981-06-01

311

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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.

Paul Chambers

312

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

Directory of Open Access Journals (Sweden)

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.

Paul Chambers

2010-01-01

313

OPTIMUM PARTITION PARAMETER OF DIVIDE-AND-CONQUER ALGORITHM FOR SOLVING CLOSEST-PAIR PROBLEM  

Directory of Open Access Journals (Sweden)

Full Text Available Divide and Conquer is a well known algorithmic procedure for solving many kinds of problem. In thisprocedure, the problem is partitioned into two parts until the problem is trivially solvable. Finding thedistance of the closest pair is an interesting topic in computer science. With divide and conqueralgorithm we can solve closest pair problem. Here also the problem is partitioned into two parts until theproblem is trivially solvable. But it is theoretically and practically observed that sometimes partitioningthe problem space into more than two parts can give better performances. In this paper, a new proposalis given that dividing the problem space into (n) number of parts can give better result while divide andconquer algorithm is used for solving the closest pair of point’s problem.

Mohammad Zaidul Karim; Nargis Akter

2011-01-01

314

Harmonic-suppressed quadrature-input frequency divider for OFDM systems  

International Nuclear Information System (INIS)

[en] 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)

2011-12-01

315

Harmonic-suppressed quadrature-input frequency divider for OFDM systems  

Science.gov (United States)

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.

Haipeng, Fu; Junyan, Ren; Wei, Li; Ning, Li

2011-12-01

316

Temporal and Spatial Variability in Snow Accumulation at WAIS Divide over Recent Centuries  

Science.gov (United States)

Temporal and spatial variability in snow accumulation was evaluated using ice cores collected in 2000 (ITASE 00-1) and 2005 (WDC05A, WDC05Q) from the West Antarctic Ice Sheet Divide (WAIS Divide) project site. The ice cores were dated based on annual layer counting of multiple glaciochemical measurements resulting in mean annual accumulation rates of 0.200, 0.204, and 0.221 mweq yr-1 for WDC05A, WDC05Q, and ITASE 00-1, respectively. An analysis of variance of accumulation in the ice core array was used to determine the small scale spatial variability (SSV), allowing for quantification of uncertainty in an individual accumulation record. The spatial variability for the WAIS Divide project site was calculated to be 0.030 mweq yr-1, or approximately 15% of the average annual accumulation. An accumulation record representative of the WAIS Divide local area over recent centuries was developed using a principal component analysis of the array to identify the coherent accumulation signal. The WAIS Divide local area accumulation record did not exhibit a trend over recent centuries, with 14% inter-annual variability (1-standard deviation of the mean) and SSV of 0.017 mweq yr-1. Correlations between the WAIS Divide local accumulation record and atmospheric indices (e.g., Antarctic Oscillation and El-Nino Southern Oscillation) exhibited periods when the records oscillate in and out of phase. Thus, identifying relationships between WAIS Divide accumulation records and geophysical processes over recent centuries may be problematic.

McConnell, J. R.; Banta, J. R.

2008-12-01

317

A 5-GHz programmable frequency divider in 0.18-{mu}m CMOS technology  

Energy Technology Data Exchange (ETDEWEB)

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-{mu}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 mm{sup 2}. The experimental results indicate that the programmable divider works well for its application in frequency synthesizers. (semiconductor integrated circuits)

Shu Haiyong; Li Zhiqun, E-mail: zhiqunli@seu.edu.c [Institute of RF- and OE-ICs, Southeast University, Nanjing 210096 (China)

2010-05-15

318

Divided attention of adolescents related to lifestyles and academic and family conditions.  

UK PubMed Central (United Kingdom)

BACKGROUND: Development of the ability to divide attention is of crucial importance in the transitional period from elementary to junior high school. The relationship between divided attention and the prevalence of fatigue or low academic motivation is observed in junior high school students. In order to clarify the factors underlying decreased ability to divide attention, we examined the relationships between divided attention, as assessed by the kana pick-out test, lifestyle factors, and academic and family conditions in junior high school students. METHODS: The study group consisted of 158 healthy 1st-, 2nd-, and 3rd-grade level junior high school students. Each participant performed the kana pick-out test and questionnaires dealing with lifestyle factors (nocturnal sleeping hours on school days, breakfast, exercise, watching television, and spending time with family members), and academic and family conditions (good friendships at school and praise from family members when participants showed good academic performance). RESULTS: On multiple regression analyses adjusted for grade and gender, scores on the kana pick-out test were positively associated with spending time with family members. In addition, the comprehension score of the kana pick-out test was positively associated with having breakfast every day and praise by family members. The score was negatively associated with watching television. CONCLUSION: The present findings suggest that the ability to divide attention is independently associated with good lifestyles and academic and family conditions in junior high school students.

Mizuno K; Tanaka M; Fukuda S; Imai-Matsumura K; Watanabe Y

2013-05-01

319

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

International Nuclear Information System (INIS)

[en] 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)

2010-01-01

320

Method for extracting, distilling and separating acetonitrile-phenylmethane by utilizing dividing-wall rectifying tower  

UK PubMed Central (United Kingdom)

The invention discloses a method for extracting, distilling and separating acetonitrile-phenylmethane by utilizing dividing-wall rectifying tower, which belongs to separation techniques for an acetonitrile-phenylmethane azeotropic mixture. In the method, durene (1,2,4,5-durene) is preferably used as an extracting agent, the adopted device is an extractive rectifying tower provided with a dividing wall, and a dividing wall is installed in the vertical direction of a common rectifying tower to divide the tower into four parts. Region I is an extractive rectifying region, and the main body of the region I is provided with a tower tray and a filler a sealing plate is arranged between region II and region III the region II is an extracting agent recovery region and since the extracting agent can be more easily separated in general and the extracting agent recovery region requires a smaller number of theoretical plates as compared with the extractive rectifying region, the position of the sealing plate can be adjusted by controlling the quantity of the tower trays or the filler. Region III is not additionally provided with any tower tray or filler. Region IV is the common stripping section of the region I and the region II. The invention can separate out high-purity acetonitrile and phenylmethane by using accessible, cheap and efficient extracting agent through extractive rectification with a dividing wall. The method reduces the equipment investment and energy consumption by more than 20% as compared with the conventional continuous extractive rectification.

ZHONGKE CHENG; BINGLI DONG; WENJIA GOU; JIANFENG HUANG; XIANGBING KONG; FEI LIU; YINGHAI MA; YAN NI; HAIOU REN; BANGYONG SONG; MEI WANG; XIAOQIANG WANG; YANFEI WANG; SONGXIAN ZHANG; JINBO ZHOU

 
 
 
 
321

Water Watch  

Energy Technology Data Exchange (ETDEWEB)

This issue of [open quotes]Water Watch,[close quotes] focusing on streamflow, is based on reports and data provided by the National Weather Service Office of hydrology and River Forecast Centers, US Department of Agriculture, the Bureau of Reclamation, Soil Conservation Service, California Department of Water Resources, and the US Geological Survey. Ninety-day outlooks are through August. For purposes of reporting, the US is divided into six regions. The data presented can be used to observe how weather conditions affected hydro generation in May.

Gruber, N.

1993-08-01

322

Water watch  

Energy Technology Data Exchange (ETDEWEB)

This issue of [open quotes]Water Watch[close quotes] focuses on soil moisture and fall streamflow, particularly in the Western US. The information is based on reports and data provided by the National Weather Service Office of Hydrology, the US Dept. of Agriculture, the Bureau of Reclamation, the Soil Conservation Service, the California Dept. of Water Resources, and the US Geological Survey. Ninety-day outlooks are through October 1992. For purposes of reporting, the US is divided into six regions. The data can be used to observe how weather conditions affected hydro generation in July.

1992-10-01

323

Prenatal diagnosis of spontaneous septostomy of the dividing membranes in complicated monochorionic diamniotic multiple gestations.  

UK PubMed Central (United Kingdom)

OBJECTIVE: The purpose of this series is to describe the prenatal diagnostic and management challenges of spontaneous septostomy of the dividing membrane (SSDM) in complicated monochorionic diamniotic (MoDi) pregnancies. METHODS: A retrospective review of all MoDi multiple gestations referred for fetal therapy was conducted. Spontaneous septostomy of the dividing membrane was suspected if a prior invasive procedure had not been performed and the following sonographic hallmarks were identified: twins occupying the same side of the dividing membrane, twin-twin transfusion syndrome (TTTS) with polyhydramnios in the donor's sac despite a collapsed donor bladder, and umbilical cord entanglement. Spontaneous septostomy of the dividing membrane was confirmed in all cases at the time of surgical fetoscopy, which was performed to treat an underlying condition of TTTS, selective intrauterine growth restriction (SIUGR), or the twin reversed arterial perfusion (TRAP) sequence. RESULTS: Of 217 complicated MoDi multiple gestations without prior invasive procedures referred for possible fetal therapy, 4 (1.8%) were identified with SSDM. The mean (range) gestational age at diagnosis was 19.7 (18-20.9) weeks. Two cases were diagnosed with TTTS complicated by SSDM after both fetuses were identified on the same side of the dividing membranes (1 case) or polyhydramnios was noted in the donor's sac despite a collapsed donor bladder (1 case). Both cases had substantial preoperative fetal deterioration because of a delay in diagnosis and treatment of TTTS. The remaining 2 SSDM cases, 1 with SIUGR and 1 with the TRAP sequence, were diagnosed after umbilical cord entanglement was recognized. CONCLUSIONS: Spontaneous septostomy of the dividing membrane in MoDi gestations is a rare condition that poses diagnostic and management challenges.

Chmait RH; Aghajanian P; Kontopoulos EV; Quintero RA

2009-05-01

324

Marker-independent method for isolating slow-dividing cancer stem cells in human glioblastoma.  

UK PubMed Central (United Kingdom)

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.

Richichi C; Brescia P; Alberizzi V; Fornasari L; Pelicci G

2013-07-01

325

Marker-independent method for isolating slow-dividing cancer stem cells in human glioblastoma.  

Science.gov (United States)

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. PMID:23814495

Richichi, Cristina; Brescia, Paola; Alberizzi, Valeria; Fornasari, Lorenzo; Pelicci, Giuliana

2013-07-01

326

Marker-independent Method for Isolating Slow-Dividing Cancer Stem Cells in Human Glioblastoma12  

Science.gov (United States)

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.

Richichi, Cristina; Brescia, Paola; Alberizzi, Valeria; Fornasari, Lorenzo; Pelicci, Giuliana

2013-01-01

327

Numerical Analysis of Pulsatile Blood Flow in a Stented Human Coronary Artery with a Flow Divider  

Directory of Open Access Journals (Sweden)

Full Text Available Shear stress is known to play a central role in restenosis formation and is sensitive to stent geometry. Local flow alterations created by a different stents without and with flow divider were studied to compare the hemodynamic effects of Stent design properties on restenosis in stented human coronary artery. Blood pressure and shear stress values were computed in three different sites, including stented arterial segment, pre-stent and post-stent regions using computational fluid dynamics. Blood flow was assumed as pulsatile, incompressible and Newtonian flow. Rigid boundary conditions were assumed for all models. The governing Navier-Stokes equations were solved using commercial software package (Fluent V6.0.12). Stents are assumed with real structure and modeled using the commercial software package (Gambit, V2.0). The arterial wall shear stress distribution was investigated in three major regions and critical sites were located. It is concluded that the wall shear stress between stent struts was sensitive to strut spacing, profile of strut, number of struts and curvature. Our 3D computational fluid dynamics modeling demonstrate that with increasing the angle between two sides of the stent strut the percentage of intrastrut area that exposed to critical value of WSS decreases. By application of a flow divider, the wall shear stress in stented segment increases markedly and so is the pressure gradient in stented segment. Flow divider influences the blood flow pattern in proximal of stented segment. In this section, the WSS increases with application of the flow divider. The results for different diameters of flow divider show that optimum diameter for flow divider is D/3.

Vahab Dehlaghi; Mohammad T. Shadpoor; Siamak Najarian

2007-01-01

328

MRI enterography with divided dose oral preparation: Effect on bowel distension and diagnostic quality.  

UK PubMed Central (United Kingdom)

AIM: To assess the impact of an extended oral preparation magnetic resonance (MR) enterography protocol on bowel distension, timing of imaging, and the quality of diagnostic images. MATERIALS AND METHODS: An analysis of 52 patients who underwent divided oral preparation and 39 patients who underwent standard preparation for MR enterography examination was done. Distension was assessed by measuring the transverse diameters of the jejunum, ileum, and the ileocecal region. Diagnostic quality of the examination was assessed subjectively by two radiologists and graded as poor, diagnostic, and excellent (Grades 1-3). Correlation between bowel diameter and diagnostic quality was assessed using regression analysis. RESULTS: The mean diameters of the jejunum, ileum, and colon in patients who underwent divided preparation were 1.90 ± 0.47, 2.14 ± 0.41, and 4.27 ± 0.96 cm, respectively, and the mean diameters in patients who underwent standard preparation were 1.46 ± 0.47, 2.02 ± 0.47, and 4.45 ± 0.90 cm, respectively. A total of 96.6% of patients on divided dose had diagnostic distension of the bowel (Grades 2 and 3). A total of 87.9% of the patients on standard dose had diagnostic distension of the bowel (Grades 2 and 3). A greater number of patients who underwent divided preparation had diagnostic quality examinations compared to those given standard preparation (96.6% vs. 87.9%). A greater number of patients who underwent divided preparation had Grade 3 quality examinations compared to those on standard preparation (75.5% vs. 68.5%). There was significant difference between diagnostic (Grades 2 and 3) and optimal grades (Grade 3) of the jejunal diameters in patients having divided or standard preparation (89.7% vs. 66.6%, P < 0.05; 40.8% vs. 25%, P < 0.05, respectively). Linear regression showed a positive correlation between increasing bowel diameter and diagnostic grade of the examination (? = 0.76). CONCLUSION: Using an extended oral preparation with divided dose resulted in the majority of patients being scanned in a single visit to the MRI suite. Dividing the oral contrast into aliquots can promote uniform distension of the entire small bowel and provide better bowel distension and improve the diagnostic quality.

Sinha R; Rawat S

2013-01-01

329

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

CERN Multimedia

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.

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

330

MRI enterography with divided dose oral preparation: Effect on bowel distension and diagnostic quality  

Science.gov (United States)

Aim: To assess the impact of an extended oral preparation magnetic resonance (MR) enterography protocol on bowel distension, timing of imaging, and the quality of diagnostic images. Materials and Methods: An analysis of 52 patients who underwent divided oral preparation and 39 patients who underwent standard preparation for MR enterography examination was done. Distension was assessed by measuring the transverse diameters of the jejunum, ileum, and the ileocecal region. Diagnostic quality of the examination was assessed subjectively by two radiologists and graded as poor, diagnostic, and excellent (Grades 1-3). Correlation between bowel diameter and diagnostic quality was assessed using regression analysis. Results: The mean diameters of the jejunum, ileum, and colon in patients who underwent divided preparation were 1.90 ± 0.47, 2.14 ± 0.41, and 4.27 ± 0.96 cm, respectively, and the mean diameters in patients who underwent standard preparation were 1.46 ± 0.47, 2.02 ± 0.47, and 4.45 ± 0.90 cm, respectively. A total of 96.6% of patients on divided dose had diagnostic distension of the bowel (Grades 2 and 3). A total of 87.9% of the patients on standard dose had diagnostic distension of the bowel (Grades 2 and 3). A greater number of patients who underwent divided preparation had diagnostic quality examinations compared to those given standard preparation (96.6% vs. 87.9%). A greater number of patients who underwent divided preparation had Grade 3 quality examinations compared to those on standard preparation (75.5% vs. 68.5%). There was significant difference between diagnostic (Grades 2 and 3) and optimal grades (Grade 3) of the jejunal diameters in patients having divided or standard preparation (89.7% vs. 66.6%, P < 0.05; 40.8% vs. 25%, P < 0.05, respectively). Linear regression showed a positive correlation between increasing bowel diameter and diagnostic grade of the examination (? = 0.76). Conclusion: Using an extended oral preparation with divided dose resulted in the majority of patients being scanned in a single visit to the MRI suite. Dividing the oral contrast into aliquots can promote uniform distension of the entire small bowel and provide better bowel distension and improve the diagnostic quality.

Sinha, Rakesh; Rawat, Sudarshan

2013-01-01

331

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

Directory of Open Access Journals (Sweden)

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.

Bamidele A. OJO

2009-01-01

332

Hybrid zone dynamics, assortative mating, and migratory programmes in a willow warbler migratory divide  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this thesis I will compare and contrast the two willow warbler subspecies (Phylloscopus trochilus trochilus and P. t. acredula) with differing migratory phenotypes (or "migratype") in the context of their migratory divide and hybrid zone in central Sweden. Their migratory programs diffe...

Larson, Keith W.

333

Education for Global Citizenship in a Divided Society? Young People's Views and Experiences  

Science.gov (United States)

Global citizenship education has been suggested as a means of overcoming the limitations of national citizenship in an increasingly globalised world. In divided societies, global citizenship education is especially relevant and problematic as it offers the opportunity to explore identities and conflict in a wider context. This paper therefore…

Niens, Ulrike; Reilly, Jacqueline

2012-01-01

334

David Sanders. A Divided Poet: Robert Frost, North of Boston, and the Drama of Disappearance.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

David Sanders in his monograph entitled A Divided Poet: Robert Frost, North of Boston, and the Drama of Disappearance (2011) sheds light on the dilemmas, doubts and personal conflicts Frost confronted while composing his poetic collection North of Boston in which some of his most well-known lyrics, ...

Tatiani G. Rapatzikou

335

Quantifying and Mapping the Digital Divide from an Internet Point of View  

Energy Technology Data Exchange (ETDEWEB)

Quantitative knowledge of the magnitude, extent and trends of the Digital Divide are critical to understand and identify the regions most in need of help, to make rational decisions on how to address the problems and to make cases for executives, funding agencies and politicians. We report on a project (PingER) to measure the Digital Divide from the point of view of Internet performance. The PingER project has been measuring Internet performance since 1995 and with the increased emphasis on measuring and tracking the Digital Divide, it now covers over 700 hosts in over 150 countries that between them contain over 99% of the world's Internet connected population. In this paper we will describe the how PingER works, it deployment, the data analysis, and presentation. We also introduce a new PingER visualization tool (ViPER) that provides a more appealing interactive visualization of the PingER data and also works on mobile PDAs. We will also show results from PingER that illustrate the magnitude, extent and trends for the Digital Divide, and also compare PingER results with some human development and technology indices.

Cottrell, R.Les; /SLAC; Khan, Shahryar; /NUST, Rawalpindi; Williams, Jerrod; /SLAC; Mehdi, Akbar; Kalim, Umar; Ali, Arshad; /NUST, Rawalpindi

2008-09-18

336

Similar perceptual costs for dividing attention between retina- and space-centered targets in humans.  

Science.gov (United States)

Visual-spatial attention enhances the perception of behaviorally relevant stimuli. One issue that remains unclear is whether attention is preferentially allocated to stimuli that remain fixed in one reference frame (e.g., retina-centered), or whether it could be equally allocated to stimuli fixed in other frames. We investigated this issue by asking observers to covertly attend to sinusoidal gratings fixed in different reference frames and to discriminate changes in their orientation. First, we quantified orientation discrimination thresholds (ODTs) while subjects pursued a moving dot and either attended to a retina- or a space-centered grating. We then measured ODTs while subjects divided attention between the two gratings. We found that dividing attention proportionally increased ODTs for both target gratings relative to the focused attention condition. Second, we used the same stimulus configuration and conditions during a fixation task. Here, one grating was retina- and space-centered while the other moved in space and on the retina. Again, ODTs during divided attention proportionally increased for both gratings. These increases were similar to those measured during smooth pursuit. Our results show that humans can proportionally divide attention between targets centered in different reference frames during both smooth pursuit eye movements and fixations. PMID:21047736

Niebergall, Robert; Huang, Lawrence; Martinez-Trujillo, Julio C

2010-10-01

337

Similar perceptual costs for dividing attention between retina- and space-centered targets in humans.  

UK PubMed Central (United Kingdom)

Visual-spatial attention enhances the perception of behaviorally relevant stimuli. One issue that remains unclear is whether attention is preferentially allocated to stimuli that remain fixed in one reference frame (e.g., retina-centered), or whether it could be equally allocated to stimuli fixed in other frames. We investigated this issue by asking observers to covertly attend to sinusoidal gratings fixed in different reference frames and to discriminate changes in their orientation. First, we quantified orientation discrimination thresholds (ODTs) while subjects pursued a moving dot and either attended to a retina- or a space-centered grating. We then measured ODTs while subjects divided attention between the two gratings. We found that dividing attention proportionally increased ODTs for both target gratings relative to the focused attention condition. Second, we used the same stimulus configuration and conditions during a fixation task. Here, one grating was retina- and space-centered while the other moved in space and on the retina. Again, ODTs during divided attention proportionally increased for both gratings. These increases were similar to those measured during smooth pursuit. Our results show that humans can proportionally divide attention between targets centered in different reference frames during both smooth pursuit eye movements and fixations.

Niebergall R; Huang L; Martinez-Trujillo JC

2010-01-01

338

The Western North Carolina Technology Consortium: A Collaborative Approach to Bridging the Digital Divide  

Science.gov (United States)

Community college presidents face an uphill struggle in preparing their institutions for the rapidly changing technological learning environment. Visionary presidents in rural community colleges are presented with yet another challenge: that of finding themselves on the wrong side of the digital divide. This article describes how presidents of 12…

Sink, David W.; Jackson, Karen Luke; Boham, Kenneth A.; Shockley, David

2004-01-01

339

Impact of the digital divide on information literacy training in a higher education context  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper reports on a master’s study undertaken to investigate the impact of the digital divide on information literacy(IL) training of Extended Curriculum Programme (ECP) students at the Durban University of Technology (DUT). Since1994 the demographics of higher education institutions...

Segarani Naidoo; Jaya Raju

340

Gender Divide and Acceptance of Collaborative Web 2.0 Applications for Learning in Higher Education  

Science.gov (United States)

Situated in the gender digital divide framework, this survey study investigated the role of computer anxiety in influencing female college students' perceptions toward Web 2.0 applications for learning. Based on 432 college students' "Web 2.0 for learning" perception ratings collected by relevant categories of "Unified Theory of Acceptance and Use…

Huang, Wen-Hao David; Hood, Denice Ward; Yoo, Sun Joo

2013-01-01

 
 
 
 
341

Understanding gender bias in face recognition: effects of divided attention at encoding.  

Science.gov (United States)

Prior research has demonstrated a female own-gender bias in face recognition, with females better at recognizing female faces than male faces. We explored the basis for this effect by examining the effect of divided attention during encoding on females' and males' recognition of female and male faces. For female participants, divided attention impaired recognition performance for female faces to a greater extent than male faces in a face recognition paradigm (Study 1; N=113) and an eyewitness identification paradigm (Study 2; N=502). Analysis of remember-know judgments (Study 2) indicated that divided attention at encoding selectively reduced female participants' recollection of female faces at test. For male participants, divided attention selectively reduced recognition performance (and recollection) for male stimuli in Study 2, but had similar effects on recognition of male and female faces in Study 1. Overall, the results suggest that attention at encoding contributes to the female own-gender bias by facilitating the later recollection of female faces. PMID:23422290

Palmer, Matthew A; Brewer, Neil; Horry, Ruth

2013-02-17

342

Understanding gender bias in face recognition: effects of divided attention at encoding.  

UK PubMed Central (United Kingdom)

Prior research has demonstrated a female own-gender bias in face recognition, with females better at recognizing female faces than male faces. We explored the basis for this effect by examining the effect of divided attention during encoding on females' and males' recognition of female and male faces. For female participants, divided attention impaired recognition performance for female faces to a greater extent than male faces in a face recognition paradigm (Study 1; N=113) and an eyewitness identification paradigm (Study 2; N=502). Analysis of remember-know judgments (Study 2) indicated that divided attention at encoding selectively reduced female participants' recollection of female faces at test. For male participants, divided attention selectively reduced recognition performance (and recollection) for male stimuli in Study 2, but had similar effects on recognition of male and female faces in Study 1. Overall, the results suggest that attention at encoding contributes to the female own-gender bias by facilitating the later recollection of female faces.

Palmer MA; Brewer N; Horry R

2013-03-01

343

Divide-and-Evolve: a New Memetic Scheme for Domain-Independent Temporal Planning  

Digital Repository Infrastructure Vision for European Research (DRIVER)

An original approach, termed Divide-and-Evolve is proposed to hybridize Evolutionary Algorithms (EAs) with Operational Research (OR) methods in the domain of Temporal Planning Problems (TPPs). Whereas standard Memetic Algorithms use local search methods to improve the evolutionary solutions, and thu...

Schoenauer, Marc; Savéant, Pierre; Vidal, Vincent

344

Combining polyamine depletion with radiation therapy for rapidly dividing head and neck tumors: Strategies for improved locoregional control  

Energy Technology Data Exchange (ETDEWEB)

Locoregional control is adversely affected as clonogens from rapidly proliferating tumors repopulate during a course of radiation therapy. The cytostatic agent [alpha]-difluoromethylornithine (DFMO) was investigated for its capacity to slow proliferation kinetics in human squamous cell carcinomas (SSC) of the head and neck (H N), with the ultimate objective of improving locoregional control in rapidly dividing tumors treated with radiation therapy. Three human SSC cell lines established from primary H N tumors were evaluated in vitro (cell culture) and in vivo (SSC tumor xenografts in athymic mice) for the capacity of DFMO to induce growth inhibition. Flow cytometry analysis of SCC tumor growth kinetics and quantitative assessment of polyamine biosynthesis inhibition was performed to verify DFMO activity. DFMO effects on in vitro SSC radiosensitivity using clonogenic survival were also studied. A noncytotoxic exposure to DFMO (5mM [times] 72 hours) induced pronounced growth inhibition in all three SSC cell lines (70-90% at 7 days), and induced a 2-3 fold delay in volume doubling time for SCC tumor xenografts when administered orally in the drinking water (1.5%) to athymic mice. Kinetic analysis via flow cytometry confirmed that DFMO produced a lengthening of SCC cell cycle times, but did not alter in vitro radiosensitivity. Inhibition of ornithine decarboxylase (ODC) activity and depletion of endogenous polyamines (putrescine and spermidine), were confirmed in normal tissue (mouse skin) and in human SSC tumor xenografts of athymic mice receiving continuous oral DFMO. These data indicate that antiproliferative agents, such as DFMO, are capable of altering human SSC growth kinetics without altering intrinsic radiosensitivity. Such kinetic modulation may therefore provide a strategy to reduce the adverse impact of tumor cell proliferation during a radiotherapy treatment course for rapidly dividing tumors such as those in the H N. 33 refs., 5 figs., 3 tabs.

Petereit, D.G.; Harari, P.M.; Contreras, L.; Pickart, M.A.; Verma, A.K.; Kinsella, T.J. (Univ. of Wisconsin Comprehensive Cancer Center, Madison, WI (United States)); Gerner, E.W. (Univ. of Arizona Cancer Center, Tucson, AZ (United States))

1994-03-01

345

[Formation, development and changes of the eye acupunture region-dividing acupoint location program].  

Science.gov (United States)

Eye acupuncture, a micro-needling therapy, has been widely applied in clinical treatment for over 30 years. Its theoretic system, especially, the eye acupuncture region-dividing point location program has been revised for 2 times, and the third program with reasonability of acupoint distribution, strictness of angle of acupoint region is easily accepted by clinical workers. In the paper, the theoretical basis of professor Peng Jingshan's inspection of the eye for recognition of diseases, diagnosis of diseases and eye acupuncture therapy were explained, and the information, development and change of the eye acupuncture region-dividing acupoint location program were analyzed and the history of development of eye acupuncture were introduced so as to direct clinical application of eye acupuncture. PMID:16309109

Che, Jian; Tian, Wei-zhu

2005-04-01

346

[Formation, development and changes of the eye acupunture region-dividing acupoint location program].  

UK PubMed Central (United Kingdom)

Eye acupuncture, a micro-needling therapy, has been widely applied in clinical treatment for over 30 years. Its theoretic system, especially, the eye acupuncture region-dividing point location program has been revised for 2 times, and the third program with reasonability of acupoint distribution, strictness of angle of acupoint region is easily accepted by clinical workers. In the paper, the theoretical basis of professor Peng Jingshan's inspection of the eye for recognition of diseases, diagnosis of diseases and eye acupuncture therapy were explained, and the information, development and change of the eye acupuncture region-dividing acupoint location program were analyzed and the history of development of eye acupuncture were introduced so as to direct clinical application of eye acupuncture.

Che J; Tian WZ

2005-04-01

347

An Uncontrolled Item of Enterprise ICT Innovation: the High Level Digital Divide  

Directory of Open Access Journals (Sweden)

Full Text Available The globalization phenomena strongly stresses western countries’ economies. Especially in industrial districts, companies are reacting with continuous innovations in product and process, based mainly on the introduction of ICT. This continuous organizational change process forces employees to keep in touch with the working environment in an endless learning process. Therefore, the introduction of new ICT seems to bring a cultural development for individuals. Is this always true? Our conviction is that the strong ICT impact generates a new form of digital-divide, a “High-Level Digital Divide” (HLDD): an increasing cultural distance between people able to follow the enterprise ICT evolution and complexity, and people with a lower cultural growth ability. An uncontrolled growth of HLDD may limit the evolution capacity of the enterprise and drop out people from labor market.

Maurizio Pighin; Anna Marzona

2008-01-01

348

Consideration of pinning and dissolution with dividing sites in Monte Carlo simulation of grain growth  

International Nuclear Information System (INIS)

Various distributions of particle size are considered in the present work to study the effect of pinning by a bimodal distribution of particles on grain growth simulation in comparison with that of the real distribution of MnS (30-50 nm) and AlN (5-8 nm) in a Fe3%Si alloy grade HiB. A dividing site technique is used to make easy consideration of different size of particles together without increasing matrix size for calculation. The dissolution of precipitates introduced after the stagnation stage allows grain growth to start again.The dividing sites technique allows the consideration of particle dissolution by gradual vanishing of peripheral layers of particles, in agreement with the experimental evolution.

2010-07-01

349

Flow-Through Divided Latissimus Dorsi Musculocutaneous Flap for Large Extremity Defects.  

UK PubMed Central (United Kingdom)

Reconstructing large defects of the extremities is a challenging problem for reconstructive microsurgeons. The latissimus dorsi musculocutaneous flap (LDMCF) is widely used for this purpose, but a skin graft is needed when the defect is wider than available flaps. We used flow-through divided LDMCFs to reconstruct large defects of the extremities in 5 consecutive patients from 2010 through 2012. The semicircular skin island was split longitudinally, and 1 skin island was advanced over the other to close a round or oval defect without a skin graft. Postoperatively, all flaps survived completely, and the mean Enneking score was 90.0%. The flow-through divided LDMCF is a reliable and versatile option for reconstructing large defects of the extremities.

Miyamoto S; Kayano S; Fujiki M; Kamizono K; Fukunaga Y; Sakuraba M

2013-08-01

350

The household energy gap: examining the divide between habitual- and purchase-related conservation behaviours  

International Nuclear Information System (INIS)

This paper examines the conceptual divide between energy saving behaviours in the home, relating to purchase-oriented behaviours and habitual action to conserve energy. Considerable empirical research indicates that this divide is of utility when characterising energy saving behaviour. However, little attention has been focused around the association between energy saving behaviours and other environmental actions. Accordingly, this paper examines the structural bases of energy conservation behaviours in the wider context of environmental behaviour. These findings are then used to examine the characteristics of energy savers as they relate to other environmental actions. Using cluster analysis, the paper defines a range of behavioural characteristics that transcend energy saving and other environmental actions. The use of such an approach to policy makers seeking to encourage energy conservation practices is discussed at the end of the paper.

2005-01-01

351

Asteroid lightcurve analysis at the Palmer Divide Observatory - March - June 2006  

Science.gov (United States)

Lightcurves for 22 asteroids were obtained at the Palmer Divide Observatory from early March through early June 2006: 216 Kleopatra, 314 Rosalia, 618 Elfriede, 633 Zelima, 1064 Aethusa, 1115 Sabauda, 1320 Impala, 1384 Kniertje, 1546 Izsak, 1592 Mathieu, 2047 Smetana, 3318 Blixen, 3642 Frieden, 4077 Asuka, 4985 Weir, 4091 Lowe, 5222 Ioffe, 6296 Cleveland, 5430 Luu, (7563) 1988 BC, 21022 Ike, and (68950) 2002 QF15.

Warner, Brian D.

2006-12-01

352

Contested Normative Cultures. Gendered Perspectives on Religions and the Public/Private Divide.  

DEFF Research Database (Denmark)

The article considers religious and secular normative cultures from a gendered perspective focusing on gender and the class and gender privileges linked to the introduction of a public/private divide. It finally discusses issues concerning 'gender display' and gender performance in the 21st century as a field, where 'religion', 'public', 'private' and 'gender' overlap, interact, and possibly take on new forms and new meanings and changes all involved actors.

Petersen, Hanne

2012-01-01

353

Divided visual attention as a predictor of bumping while walking: the Salisbury Eye Evaluation.  

UK PubMed Central (United Kingdom)

PURPOSE: The purpose of this study was to determine the association between bumping while walking and divided visual attention, as measured by the useful field of view (UFOV). METHODS: The Salisbury Eye Evaluation is a population-based study of community-dwelling adults, aged 72 to 92 at the third round of data collection. Participants walked a circuitous 32.8-m course, seeded with obstacles, and the number of bumps made while traversing the course was counted. UFOV divided attention score was based on processing speed: the time taken to identify a central target, and the location of a peripheral target simultaneously. Association between number of bumps and UFOV score was assessed in a generalized linear model, with adjustment for vision and attention measures that might explain the UFOV score. RESULTS: Of the 1504 participants in this study, 10.1% did not attempt the mobility course. In a model adjusting for demographic, physical, cognitive and attention, and vision measures, a decrease of 50 ms in processing speed for the divided-attention task was associated with a 4.9% increase (P = 0.004) in number of bumps made over the course. Receiver operating characteristic curves were created for the UFOV and visual field tests, to determine accuracy in detecting those with a high number of bumps. The visual field test had slightly higher area under the curve, but positive predictive value for both tests was low. CONCLUSIONS: The UFOV test of divided attention, as measured by processing speed, independently predicted bumping while walking. These data suggest that poor visual attention is a significant risk factor for bumping while walking.

Broman AT; West SK; Muñoz B; Bandeen-Roche K; Rubin GS; Turano KA

2004-09-01

354

Index k saddles and dividing surfaces in phase space, with applications to isomerization dynamics  

CERN Multimedia

In this paper we continue our studies of the phase space geometry and dynamics associated with index k saddles (k > 1) of the potential energy surface. Using normal form theory, we give an explicit formula for a "dividing surface" in phase space, i.e. a co-dimension one surface (within the energy shell) through which all trajectories that "cross" the region of the index k saddle must pass. With a generic non-resonance assumption, the normal form provides k (approximate) integrals that describe the saddle dynamics in a neighborhood of the index k saddle. These integrals provide a symbolic description of all trajectories that pass through a neighborhood of the saddle. We give a parametrization of the dividing surface which is used as the basis for a numerical method to sample the dividing surface. Our techniques are applied to isomerization dynamics on a potential energy surface having 4 minima; two symmetry related pairs of minima are connected by low energy index one saddles, with the pairs themselves connect...

Collins, Peter; Wiggins, Stephen

2011-01-01

355

Bridging the Communication Divide: A Role for Health Psychology in the Genomic Era.  

Science.gov (United States)

The application of genomics to population health has the potential to revolutionize the practice of medicine. Indeed, discoveries into the genomic basis of cancer and other common chronic diseases have resulted in new and improved predictive tests for identifying individuals at increased risk for these conditions and long before their onset occurs. When used properly, information gained from predictive genomic tests can be combined with other leading indicators (e.g., environmental and behavioral risk factors) to inform medical management decisions, preventive health practices, and risk-reducing strategies. However, genomics remains an emerging science and the translation of genomic discoveries into improved population health management remains elusive. There are divides in the translational science continuum at several junctures, and many of these divides could be narrowed or closed with additional data. For example, we know relatively little about how to effectively communicate with the public about the complex interplay among genomics, behavior, and health. Moreover, there is a need to develop better methods of counseling and educating the public in light of newly emerging knowledge about the genomic basis of health and disease. We assert that the discipline of psychology, and health psychology in particular, is well-poised to continue to make significant contributions to this growing area of science and practice. Through a focus on health-related social and behavioral research, psychology can lead the way in overcoming divides in communication, understanding, and action about genomics for the betterment of both individual and public health practices. PMID:23503693

Tercyak, Kenneth P; O'Neill, Suzanne C; Roter, Debra L; McBride, Colleen M

2012-12-01

356

Bridging the Communication Divide: A Role for Health Psychology in the Genomic Era.  

UK PubMed Central (United Kingdom)

The application of genomics to population health has the potential to revolutionize the practice of medicine. Indeed, discoveries into the genomic basis of cancer and other common chronic diseases have resulted in new and improved predictive tests for identifying individuals at increased risk for these conditions and long before their onset occurs. When used properly, information gained from predictive genomic tests can be combined with other leading indicators (e.g., environmental and behavioral risk factors) to inform medical management decisions, preventive health practices, and risk-reducing strategies. However, genomics remains an emerging science and the translation of genomic discoveries into improved population health management remains elusive. There are divides in the translational science continuum at several junctures, and many of these divides could be narrowed or closed with additional data. For example, we know relatively little about how to effectively communicate with the public about the complex interplay among genomics, behavior, and health. Moreover, there is a need to develop better methods of counseling and educating the public in light of newly emerging knowledge about the genomic basis of health and disease. We assert that the discipline of psychology, and health psychology in particular, is well-poised to continue to make significant contributions to this growing area of science and practice. Through a focus on health-related social and behavioral research, psychology can lead the way in overcoming divides in communication, understanding, and action about genomics for the betterment of both individual and public health practices.

Tercyak KP; O'Neill SC; Roter DL; McBride CM

2012-12-01

357

Maximum Likelihood-Based Iterated Divided Difference Filter for Nonlinear Systems from Discrete Noisy Measurements  

Directory of Open Access Journals (Sweden)

Full Text Available A new filter named the maximum likelihood-based iterated divided difference filter (MLIDDF) is developed to improve the low state estimation accuracy of nonlinear state estimation due to large initial estimation errors and nonlinearity of measurement equations. The MLIDDF algorithm is derivative-free and implemented only by calculating the functional evaluations. The MLIDDF algorithm involves the use of the iteration measurement update and the current measurement, and the iteration termination criterion based on maximum likelihood is introduced in the measurement update step, so the MLIDDF is guaranteed to produce a sequence estimate that moves up the maximum likelihood surface. In a simulation, its performance is compared against that of the unscented Kalman filter (UKF), divided difference filter (DDF), iterated unscented Kalman filter (IUKF) and iterated divided difference filter (IDDF) both using a traditional iteration strategy. Simulation results demonstrate that the accumulated mean-square root error for the MLIDDF algorithm in position is reduced by 63% compared to that of UKF and DDF algorithms, and by 7% compared to that of IUKF and IDDF algorithms. The new algorithm thus has better state estimation accuracy and a fast convergence rate.

Changyuan Wang; Jing Zhang; Jing Mu

2012-01-01

358

Divide-and-Evolve: a New Memetic Scheme for Domain-Independent Temporal Planning  

CERN Multimedia

An original approach, termed Divide-and-Evolve is proposed to hybridize Evolutionary Algorithms (EAs) with Operational Research (OR) methods in the domain of Temporal Planning Problems (TPPs). Whereas standard Memetic Algorithms use local search methods to improve the evolutionary solutions, and thus fail when the local method stops working on the complete problem, the Divide-and-Evolve approach splits the problem at hand into several, hopefully easier, sub-problems, and can thus solve globally problems that are intractable when directly fed into deterministic OR algorithms. But the most prominent advantage of the Divide-and-Evolve approach is that it immediately opens up an avenue for multi-objective optimization, even though the OR method that is used is single-objective. Proof of concept approach on the standard (single-objective) Zeno transportation benchmark is given, and a small original multi-objective benchmark is proposed in the same Zeno framework to assess the multi-objective capabilities of the pr...

Schönauer, M; Vidal, V; Schoenauer, Marc; Sav\\'{e}ant, Pierre; Vidal, Vincent

2006-01-01

359

Poor-Rich Divide in Aravind Adiga’s The White Tiger  

Directory of Open Access Journals (Sweden)

Full Text Available Aravind Adiga’s The White Tiger, which was awarded theMan Booker Prize in 2008, is singular in its fictionalized portrayal of the relationship between Balram Halwai and his master Mr Ashok. The story exposes the poor-rich divide that surrounds India in the backdrop of economic prosperity, in the wake of the IT revolution. As Michael Portillo commented the novel “shocked and entertained in equal measure” (Portillo, 2008). Written in the epistolary form, the novel is a seven-part letter to the Chinese Premier, Wen Jiabao, from Balram alias Ashok Sharma, a self-styled ‘Thinking Man / And an entrepreneur’ (TWT, 2008, p. 3). Balram the killer, metamorphoses into his master’s replica after his heinous crime. By crime and cunning, in the name of the social injustice due to existing rich-poor divide in India, Balram rules his entrepreneurial world. This paper attempts to trace the great poor-rich divide manifested through The White Tiger, having dangerous consequences, if unresolved.

A.J. Sebastian

2009-01-01

360

[The design and technique of one stage treatment of eyelid divided nevus with island skin flap].  

UK PubMed Central (United Kingdom)

OBJECTIVE: To investigate the design and technique of the one stage treatment of eyelid divided nevus with adjacent and distant island skin flap. METHODS: Under local or general anesthesia, the divided nevus on the upper and lower eyelid were excised totally or partially. According to the location, shape and size of the defect, orbicularis oculi musculocutaneous flap, postauricular SMAS-pedicled flap or reversal superficial temporal artery flap was chosen to repair the defect in one stage. The donor site was closed directly. RESULTS: Since 2003, 16 patients were treated in this group, with 10 orbicularis oculi musculocutaneous flaps, 3 postauricular SMAS-pedicled flaps, and 3 reversal superficial temporal artery flaps. The largest size of the nevus on the upper and lower eyelid were 2.5 cm x 2.0 cm and 4.0 cm x 3.0 cm, respectively. One postauricular SMAS-pedicled flap and 1 reversal superficial temporal artery flap showed distal venous refluence obstruction and epidermal necrosis in early postoperative stage, which healed through dressing. The other flaps survived completely. CONCLUSIONS: Treating eyelid divided defects with adjacent or distant island skin flap is a suitable method with satisfactory result and less morbidity in donor sites.

Wang XJ; Zhu L; Liu ZF; Qiao Q; Zeng A; Li WW; Wang Y

2010-01-01

 
 
 
 
361

Parental health information seeking and re-exploration of the 'digital divide'  

UK PubMed Central (United Kingdom)

Aim: To describe patterns of 'online' and 'offline' health information seeking in families with children under five years of age and living in five socially, economically and culturally disparate local authority (LA) wards in one inner-city area. Background: Earlier work analysed data from the five LA wards merged as one data set. A 'digital divide' in health information seeking was identified between parents who actively sought information from both internet websites and from 14 other health information sources (online health information seekers), and those who acquired information from a more limited range of sources excluding the internet. Of the two groups, the online health information seekers had higher levels of computer ownership and, therefore, internet access within the home. Method: Re-analysis of data (questionnaires n = 224; five focus groups; two interviews with service providers; two opportunistic conversations with service providers). Additional data were retrieved after the original data analysis and between 2005 and 2007. These data were from service user-led discussions (n = 30) held with parents in child health clinics, informal interviews (n = 11) with health visitors and semi-structured interviews (n = 2) with health visitors. Information was also retrieved from the Office for National Statistics data set. In the re-analysis, data were disaggregated at LA ward level in order to explore local influences on patterns of health information seeking. Results: Multiple layers of influence upon parental health information seeking emerged and revealed a non-digital second divide, which was independent of computer ownership and home internet access. This divide was based on preference for use of certain health information sources, which might be either 'online' or 'offline'. A spatial patterning of both digital and preferential divides was identified with an association between each of these and features of the physical, social, cultural and psychosocial environment, one of which was perceived access to primary health care. Conclusion: Complex patterns of health information seeking relate to each of the 'divides' - digital and preferential. Patterns of health information seeking reflect differing perceptions of information availability and usefulness as experienced by parents within their local physical, social, cultural and psychosocial worlds. Access to primary care services is a key component of this local environment.

Malone M; While A; Roberts J

2013-05-01

362

Parental health information seeking and re-exploration of the 'digital divide'  

Science.gov (United States)

Aim: To describe patterns of 'online' and 'offline' health information seeking in families with children under five years of age and living in five socially, economically and culturally disparate local authority (LA) wards in one inner-city area. Background: Earlier work analysed data from the five LA wards merged as one data set. A 'digital divide' in health information seeking was identified between parents who actively sought information from both internet websites and from 14 other health information sources (online health information seekers), and those who acquired information from a more limited range of sources excluding the internet. Of the two groups, the online health information seekers had higher levels of computer ownership and, therefore, internet access within the home. Method: Re-analysis of data (questionnaires n = 224; five focus groups; two interviews with service providers; two opportunistic conversations with service providers). Additional data were retrieved after the original data analysis and between 2005 and 2007. These data were from service user-led discussions (n = 30) held with parents in child health clinics, informal interviews (n = 11) with health visitors and semi-structured interviews (n = 2) with health visitors. Information was also retrieved from the Office for National Statistics data set. In the re-analysis, data were disaggregated at LA ward level in order to explore local influences on patterns of health information seeking. Results: Multiple layers of influence upon parental health information seeking emerged and revealed a non-digital second divide, which was independent of computer ownership and home internet access. This divide was based on preference for use of certain health information sources, which might be either 'online' or 'offline'. A spatial patterning of both digital and preferential divides was identified with an association between each of these and features of the physical, social, cultural and psychosocial environment, one of which was perceived access to primary health care. Conclusion: Complex patterns of health information seeking relate to each of the 'divides' - digital and preferential. Patterns of health information seeking reflect differing perceptions of information availability and usefulness as experienced by parents within their local physical, social, cultural and psychosocial worlds. Access to primary care services is a key component of this local environment. PMID:23676618

Malone, Mary; While, Alison; Roberts, Julia

2013-05-16

363

Water watch  

Energy Technology Data Exchange (ETDEWEB)

This issue of [open quotes]Water Watch[close quotes] focuses on soil moisture conditions across the country as of the first of April. In addition, the department describes streamflow conditions across the US forecast for April through July. The information presented is based on data from the US Geological Survey, the National Weather Service, and the Soil Conservation Service. For purposes of providing this information, the US is divided into six regions. The Hydropower Generation Report can be used to observe how weather conditions affected hydro generation in March.

1991-06-01

364

Water watch  

Energy Technology Data Exchange (ETDEWEB)

This issue of [open quotes]Water Watch[close quotes] focuses on spring flood potential based on reports and data provided by the National Weather Service Office of Hydrology, the US Department of Agriculture, the Bureau of Reclamation, the Soil Conservation Service, and the US Geological Survey. Ninety-day outlooks are through June 1992. For purposes of reporting, the US is divided into six regions. The data presented in the Hydropower Generation Report can be used to observe how weather conditions affected hydro generation in March.

1992-06-01

365

Low energy, low latency and high speed array divider circuit using a shannon theorem based adder cell.  

Science.gov (United States)

The paper discuss the design of 1-bit full adder circuit using Shannon theorem. This proposed full adder circuit is used as one of the circuit component for implementation of Non- Restoring and Restoring divider circuits. The proposed adder and divider schematics are designed by using DSCH2 CAD tool and their layouts are generated by Microwind 3 VLSI CAD tool. The divider circuits are designed by using standard CMOS 0.35 microm feature size and corresponding power supply 3.5 V. The parameters analyses are carried out by BSIM 4 analysis. We have compared the simulated results of the Shannon based divider circuit with CPL and CMOS adder cell based divider circuits. We have further compared the results with published results and observed that the proposed adder cell based divider circuit dissipates lower power, gives faster response, lower latency, low EPI and high throughput. PMID:19149756

Senthilpari, Chinnaiyan; Diwakar, Krishnamoorthy; Singh, Ajay K

2009-01-01

366

Low energy, low latency and high speed array divider circuit using a shannon theorem based adder cell.  

UK PubMed Central (United Kingdom)

The paper discuss the design of 1-bit full adder circuit using Shannon theorem. This proposed full adder circuit is used as one of the circuit component for implementation of Non- Restoring and Restoring divider circuits. The proposed adder and divider schematics are designed by using DSCH2 CAD tool and their layouts are generated by Microwind 3 VLSI CAD tool. The divider circuits are designed by using standard CMOS 0.35 microm feature size and corresponding power supply 3.5 V. The parameters analyses are carried out by BSIM 4 analysis. We have compared the simulated results of the Shannon based divider circuit with CPL and CMOS adder cell based divider circuits. We have further compared the results with published results and observed that the proposed adder cell based divider circuit dissipates lower power, gives faster response, lower latency, low EPI and high throughput.

Senthilpari C; Diwakar K; Singh AK

2009-01-01

367

Developmental fates and migratory pathways of dividing progenitors in the postnatal rat cerebellum.  

Science.gov (United States)

To investigate the developmental fates and the migratory pathways of dividing progenitors in both the white matter (WM) and the external granule layer (EGL) in the early postnatal rat cerebellum, a replication-deficient retrovirus carrying the beta-galactosidase gene (BAG) was injected into the deep cerebellar tissue or the EGL of postnatal rats to label dividing progenitors. After 1-3 days post-injection (1-3 dpi) of BAG into the deep cerebellar tissue of postnatal day 4/5 (P4/5) rats, labeled immature, unipolar cells were found mainly in the WM. From 4 to 6 dpi, similar cells appeared in the internal granule (IGL), Purkinje cell, and molecular layers, although about half of the labeled cells still resided in the WM and appeared immature. The first morphologically definable Bergmann glia, astrocytes, and oligodendrocytes were also observed. From 14 to 20 dpi, most labeled cells had developed into Bergmann glia, astrocytes, oligodendrocytes, and interneurons in their appropriate layers. When BAG injections were performed at P14, unipolar cells were initially observed, but the majority of these differentiated into myelinating oligodendrocytes in the WM and IGL by 17 dpi. Few immature cells were labeled by injections administered at P20, and these did not develop into mature glia, but into cells with lacy, fine processes, possible representing immature oligodendrocytes. In contrast, BAG-labeled progenitors of EGL produced only granule neurons. Thus, within the first 2 postnatal weeks, dividing progenitors in the WM migrate as immature cells into the cortex before differentiating into a variety of glia and interneurons. The genesis of oligodendrocytes continues through the 2nd postnatal week and largely ceases by P20. EGL cells do not produce glia, but only granule cells. PMID:8807453

Zhang, L; Goldman, J E

1996-07-01

368

Developmental fates and migratory pathways of dividing progenitors in the postnatal rat cerebellum.  

UK PubMed Central (United Kingdom)

To investigate the developmental fates and the migratory pathways of dividing progenitors in both the white matter (WM) and the external granule layer (EGL) in the early postnatal rat cerebellum, a replication-deficient retrovirus carrying the beta-galactosidase gene (BAG) was injected into the deep cerebellar tissue or the EGL of postnatal rats to label dividing progenitors. After 1-3 days post-injection (1-3 dpi) of BAG into the deep cerebellar tissue of postnatal day 4/5 (P4/5) rats, labeled immature, unipolar cells were found mainly in the WM. From 4 to 6 dpi, similar cells appeared in the internal granule (IGL), Purkinje cell, and molecular layers, although about half of the labeled cells still resided in the WM and appeared immature. The first morphologically definable Bergmann glia, astrocytes, and oligodendrocytes were also observed. From 14 to 20 dpi, most labeled cells had developed into Bergmann glia, astrocytes, oligodendrocytes, and interneurons in their appropriate layers. When BAG injections were performed at P14, unipolar cells were initially observed, but the majority of these differentiated into myelinating oligodendrocytes in the WM and IGL by 17 dpi. Few immature cells were labeled by injections administered at P20, and these did not develop into mature glia, but into cells with lacy, fine processes, possible representing immature oligodendrocytes. In contrast, BAG-labeled progenitors of EGL produced only granule neurons. Thus, within the first 2 postnatal weeks, dividing progenitors in the WM migrate as immature cells into the cortex before differentiating into a variety of glia and interneurons. The genesis of oligodendrocytes continues through the 2nd postnatal week and largely ceases by P20. EGL cells do not produce glia, but only granule cells.

Zhang L; Goldman JE

1996-07-01

369

A 420 Year Annual 10Be Record from the WAIS Divide Ice Core  

Science.gov (United States)

Annual ice layers archive the cosmogenic radionuclide 10Be, which is in turn an important proxy for solar activity, complementary to the 14C tree ring archive. Although production is primarily determined by the strength of the solar magnetic field 10Be deposition is also determined by local weather phenomena and snow accumulation rates, especially within shorter timescales. Accordingly, multiple ice core records of varying locations and accumulation rates are necessary to build a representative 10Be archive. We are presently engaged in a study to obtain continuous 10Be and 36Cl records in the West Antarctic Ice Sheet (WAIS) Divide ice core, a high snow accumulation site analogous to the GISP2 core from Greenland (Finkel and Nishiizumi1997). Here we present an annual resolution record of 10Be in the WAIS Divide core spanning the last 420 years including the Maunder (1645-1715 AD) and Dalton (1790-1830 AD) solar minima. Preliminary results for the periods of 1580-1740 and 1945-2006 AD show that the10Be flux during the Maunder Minimum was ~60% higher than in the last 60 years (4.8 vs. 3.0 x 105 atoms yr-1 cm-2). Although the low sunspot numbers during the Maunder Minimum suggest little change in solar activity, the 10Be data show that the heliomagnetic field strength continued to vary in a 11-year cycle, as observed in other annual 10Be records (e.g., Beer et al. 1990; Berggren et al. 2009). The 10Be record for the WAIS Divide core will be compared to 10Be records of Greenland ice cores as well as the 14C tree ring record. Acknowledgment. This work was supported by NSF grants ANT-0839042 and 0839137. Beer J. et al. 1990.Nature 347, 164. Finkel R. C. and Nishiizumi K. 1997.J. Geophys. Res. 102, 26,699. Berggren A.- M., et al. 2009. Geophys. Res. Lett. 36, L11801.

Woodruff, T. E.; Welten, K. C.; Caffee, M. W.; Nishiizumi, K.

2011-12-01

370

ODL and the Impact of Digital Divide on Information Access in Botswana  

Directory of Open Access Journals (Sweden)

Full Text Available Open and distance learning (ODL) has created room for the emergence of virtual education. Not only are students found everywhere and anywhere undertaking their studies and earning their degrees, but geographical boundaries between nations no longer appear to have much relevance. As the new education paradigm irretrievably alters the way teaching and learning is conducted, the application of modern educational ICTs has a major role to play.With students of transnational or cross-border education dispersed into various nooks and crannies of Botswana, many others enlist for the “home-baked” distance learning programmes from their diverse locations. Like the face-to-face conventional students, distance learners also have information needs which have to be met. But blocking the distance learners’ realization of their information needs is the digital divide, which further marginalizes the underclass of “info-poor.”The survey method was used, and a questionnaire administered to 519 students of four tertiary level distance teaching institutions that met the criteria set for the study yielded a 70.1% response rate. The results showed that while the Government of Botswana has made considerable effort to ensure country-wide access to ICT, which now constitutes an effective instrument for meeting information needs, a number of problems still exist. The factors impeding easy access are unearthed. The findings of an empirical study portraying some learners as information-rich and others as information-poor, and the consequence of distance learners studying on both sides of the digital divide, are discussed. Suggestions on bridging the digital divide are offered.

Olugbade Oladokun; Lenrie Aina

2011-01-01

371

David Sanders. A Divided Poet: Robert Frost, North of Boston, and the Drama of Disappearance.  

Directory of Open Access Journals (Sweden)

Full Text Available David Sanders in his monograph entitled A Divided Poet: Robert Frost, North of Boston, and the Drama of Disappearance (2011) sheds light on the dilemmas, doubts and personal conflicts Frost confronted while composing his poetic collection North of Boston in which some of his most well-known lyrics, such as “Mending Wall,” “After Apple-Picking,” and “The Wood-Pile,” are contained. This book should be considered alongside a number of other publications either in monograph or essay form that app...

Tatiani G. Rapatzikou

2012-01-01

372

eGY-Africa: Addressing the Digital Divide for Science in Africa  

Energy Technology Data Exchange (ETDEWEB)

Adoption of information and communication technologies and access to the Internet is expanding in Africa, but because of the rapid growth elsewhere, a Digital Divide between Africa and the rest of the world exists, and the gap is growing. In many sub-Saharan African countries, education and research sector suffer some of the worst deficiencies in access to the Internet, despite progress in development of NRENs National Research and Education (cyber) Networks. By contrast, it is widely acknowledged in policy statements from the African Union, the UN, and others that strength in this very sector provides the key to meeting and sustaining Millennium Development Goals. Developed countries with effective cyber-capabilities proclaim the benefits to rich and poor alike arising from the Information Revolution. This is but a dream for many scientists in African institutions. As the world of science becomes increasingly Internet-dependent, so they become increasingly isolated. eGY-Africa is a bottom-up initiative by African scientists and their collaborators to try to reduce this Digital Divide by a campaign of advocacy for better institutional facilities. Four approaches are being taken. The present status of Internet services, problems, and plans are being mapped via a combination of direct measurement of Internet performance (the PingER Project) and a questionnaire-based survey. Information is being gathered on policy statements and initiatives aimed at reducing the Digital Divide, which can be used for arguing the case for better Internet facilities. Groups of concerned scientists are being formed at the national, regional levels in Africa, building on existing networks as much as possible. Opinion in the international science community is being mobilized. Finally, and perhaps most important of all, eGY-Africa is seeking to engage with the many other programs, initiatives, and bodies that share the goal of reducing the Digital Divide either as a direct policy objective, or indirectly as a means to an end, such as the development of an indigenous capability in science and technology for national development. The expectation is that informed opinion from the scientific community at the institutional, national, and international levels can be used to influence the decision makers and donors who are in a position to deliver better Internet capabilities.

Barton, C. E.

2010-05-25

373

Active microwave absorber with the dual-ability of dividable modulation in absorbing intensity and frequency  

Directory of Open Access Journals (Sweden)

Full Text Available We present the design, fabrication and experimental demonstration of an electrically active absorber at microwave frequency. Unlike those proposed before, simulation and experiment data present that its working frequency and absorbing intensity can be both but separately controlled. The electromagnetic coupling analysis reveals that the feature arises from the dividable frequency and amplitude modulation on an active magnetic resonator controlled by varactor and pin diodes. Such separable modulating behaviors are further confirmed by the equivalent LC circuit model. It is believed that this will be an important step towards smart application of active absorber.

Xiaoyu Wu; Chenggang Hu; Yanqin Wang; Mingbo Pu; Cheng Huang; Changtao Wang; Xiangang Luo

2013-01-01

374

ZoneLib : A Simulink Library for Modeling Zone Divided Climate Dynamics  

DEFF Research Database (Denmark)

We present a dynamic model for climate in a livestock building divided into a number of zones, and a corresponding modular Simulink library (ZoneLib). While most literature in this area consider air flow as a control parameter we show how to model climate dynamics using actual control signals for the ventilation equipment. To   overcome a shortcoming in Simulink to solve algebraic equations and matrix inversions, we have developed the library inspired by the so called dynamic node technique. We present simulation results using the presented library, and concludes with visions for further development of ZoneLib.

Jessen, Jan Jacob; SchiØler, Henrik

2006-01-01

375

High-impedance capacitive divider probe for potential measurements in plasmas  

Energy Technology Data Exchange (ETDEWEB)

It is often desirable, though difficult, to measure electric potential changes within a plasma, including variations due to waves and fluctuations. For a broad range of plasma parameters ac floating potential measurements may be made using the high input impedance probe described in this paper. A capacitive divider with an active buffer circuit is incorporated, such that a 50-..cap omega.. line can be driven with a 60-dB dynamic range and 100-MHz bandwidth. Details of the electronic circuit, mechanical construction, and calibration of the probe are given, together with a discussion of the parameter range over which successful measurements may be made.

Benjamin, N.

1982-10-01

376

Arnold tongues for a resonant injection-locked frequency divider: analytical and numerical results  

CERN Document Server

In this paper we consider a resonant injection-locked frequency divider which is of interest in electronics, and we investigate the frequency locking phenomenon when varying the amplitude and frequency of the injected signal. We study both analytically and numerically the structure of the Arnold tongues in the frequency-amplitude plane. In particular, we provide exact analytical formulae for the widths of the tongues, which correspond to the plateaux of the devil's staircase picture. The results account for numerical and experimental findings presented in the literature for special driving terms and, additionally, extend the analysis to a more general setting.

Bartuccelli, Michele V; Gentile, Guido; Schilder, Frank

2009-01-01

377

The role of the installer in dividing heating cost; Warmtekostenverdeling, ook de installateur levert zijn deel  

Energy Technology Data Exchange (ETDEWEB)

Heating cost offsets on the basis of individual monitoring (collective heating) often is considered to be the responsibility of the building manager and the consumer. However, the installer also determines the quality of a system to divide heating costs over the consumers. In particular when also management and maintenance of the heating installation is part of the installer`s responsibility. In this article the role of the installer in different phases of the implementation of heating costs division is discussed. 5 figs., 1 ref.

Brand, R. [TNO Milieu, Energie en Procesinnovatie TNO-MEP, Apeldoorn (Netherlands); Straatman, J. [WDC Advies en Beleid, Rotterdam (Netherlands)

1996-09-01

378

Purpose of protocol for kVp determination by invasive voltage divider  

International Nuclear Information System (INIS)

This paper describes a protocol for the measurements of the maximum peak potential, absolute peak potential, average peak potential, practical peak potential, ripple and exposure time, through the invasive measurement made by high voltage divider installed between the high voltage generator and the x-ray tube. This protocol was developed based on International Electrotechnical Commission (IEC61676) and Report No. 14 of American Association of Physics in Medicine. Results are presented applying this protocol in X-ray tubes connected to a high frequency generator, average frequency generator and single phase generator. (author)

2005-09-02

379

Hugoniot measurements on a slurry of finely divided tungsten and plastic  

Energy Technology Data Exchange (ETDEWEB)

A previous paper reported hugoniot measurements on a two-phase material consisting of a matrix and an embedded material (silica- phenolic) using the LLNL electric gun facility. The results showed a good bit of scatter in the measurements. This was attributed to the grossly heterogeneous nature of the material. Measurements have since been made on a slurry of finely divided tungsten powder in a plastic, greatly reducing the scale of the inhomogeneity. The results show greatly reduced scatter, as expected from the above interpretation. 4 refs., 2 figs.

Gathers, G.R.; Chau, H.H.; Osher, J.E.; Weingart, R.C.

1991-05-01

380

Asteroid Lightcurve Analysis at the Palmer Divide Observatory - September-December 2006  

Science.gov (United States)

Lightcurves for 25 asteroids were obtained at the Palmer Divide Observatory from late September through December 2006: 143 Adria, 469 Argentina, 595 Polyxena, 880 Herba, 1515 Perrotin, 1756 Giacobini, 1920 Sarmiento, 2645 Daphne Plane, 2793 Valdaj, 4125 Lew Allen, 4142 Derzu-Uzala, 4690 Strasbourg, 4860 Gubbio, 6794 Masuisakura, (10171) 1995 EE8, 13025 Zurich, (15786) 1993 RS, 17681 Tweedledum, (24827) 1995 RA, (30019) 2000 DD, (31180) 1997 YX3, (31354) 1998 TR3, (32814) 1990 XZ, (34817) 2001 SE116, and 2006 WH1.

Warner, Brian D.

2007-06-01

 
 
 
 
381

Winding capacitance dividing scheme for a high-voltage cable-wound generator  

International Nuclear Information System (INIS)

[en] This paper presents a method which can equivalently arrange the capacitance distribution along with the winding of the generator on the terminal and neutral respectively in a reasonable partition, particularly for a type of high-voltage graded insulated cable-wound generator, powerformer. This method can be used to compensate the capacitive current wholly to improve the reliability of the differential protection. It is proved that the capacitive current in the case of normal operation, external fault and internal fault can be calculated using the same dividing method. The formula of the partition coefficient is provided and the characteristic of the coefficient is explored by MATLAB software.

2010-01-01

382

The Optimum Design Methodology of Low-Phase-Noise LC-VCO Using Multiple-Divide Technique  

Science.gov (United States)

The multiple-divide technique, using the multi-ratio frequency divider, has a possibility to improve FoM of VCO. This paper proposes a design optimization of LC-VCO using the multiple-divide technique. In the simulated results using 90-nm CMOS model parameters, the optimum frequency range, achieving better than -187.0dBc/Hz of FoM, can be extended from 6.5-12.5GHz to 1.5-12.5GHz. The proposed multiple-divide technique can provide a lower phase-noise, lower power consumption, smaller layout area of LC-VCO.

Hara, Shoichi; Murakami, Rui; Okada, Kenichi; Matsuzawa, Akira

383

High current density and nonlinearity combination of selection device based on TaO(x)/TiO2/TaO(x) structure for one selector-one resistor arrays.  

UK PubMed Central (United Kingdom)

We demonstrate a high-performance selection device by utilizing the concept of crested oxide barrier to suppress the sneak current in bipolar resistive memory arrays. Using a TaO(x)/TiO(2)/TaO(x) structure, high current density over 10(7) A cm(-2) and excellent nonlinear characteristics up to 10(4) were successfully demonstrated. On the basis of the defect chemistry and SIMS depth profile result, we found that some Ta atoms gradually diffused into TiO(2) film, and consequently, the energy band of the TiO(2) film was symmetrically bent at the top and bottom TaO(x)/TiO(2) interfaces and modified as a crested oxide barrier. Furthermore, the one selector-one resistor device exhibited significant suppression of the leakage current, indicating excellent selector characteristics.

Lee W; Park J; Kim S; Woo J; Shin J; Choi G; Park S; Lee D; Cha E; Lee BH; Hwang H

2012-09-01

384

A divide-down RF source generation system for the Advanced Photon Source  

International Nuclear Information System (INIS)

[en] A divide-down rf source system has been designed and built at Argonne National Laboratory to provide harmonically-related and phase-locked rf source signals between the APS 352-MHz storage ring and booster synchrotron rf systems and the 9.77-MHz and 117-MHz positron accumulator ring rf systems. The design provides rapid switching capability back to individual rf synthesizers for each one. The system also contains a digital bucket phase shifter for injection bucket selection. Input 352-MHz rf from a master synthesizer is supplied to a VXI-based ECL divider board which produces 117-MHz and 9.77-MHz square-wave outputs. These outputs are passed through low-pass filters to produce pure signals at the required fundamental frequencies. These signals, plus signals at the same frequencies from independent synthesizers, are fed to an interface chassis where source selection is made via local/remote control of coaxial relays. This chassis also produces buffered outputs at each frequency for monitoring and synchronization of ancillary equipment

1997-01-01

385

The Role of Working Memory and Divided Attention in Metaphor Interpretation.  

UK PubMed Central (United Kingdom)

Although several types of figurative language exist, neuropsychological tests of non-literal language have focused on proverbs. Metaphors in the form X is (a) Y (e.g., The body's immunological response is a battle against disease.) place a lower demand on language skills and are more easily manipulated for novelty than proverbs. Forty healthy participants completed the Metaphor Interpretation Test (developed by the authors). The task includes 20 items chosen from a list of metaphors that were rated on several scales (e.g. imagery, aptness) in a study by Katz et al. (Metaphor Symb Act 3(4):191-214, 1988). Participants were asked to rate the familiarity and provide an explanation of each metaphor. A scoring system was developed to categorize answers into: abstract complete (AC), abstract partial (AP), concrete (CT), and other/unrelated (OT) types. Participants also completed short-term memory and divided attention tests. Overall, participants produced 56 % AC, 25.38 % AP, 7.88 % CT, and 10.88 % OT responses. It was found that a measure of verbal short-term memory span was the best predictor of performance on this task (adjusted [Formula: see text]). It appears that short-term memory span, not working memory or divided attention, contributes most to providing abstract responses in explaining metaphors. This is in line with the idea that when one accesses the semantic network associated with a novel metaphor, one must hold this information in mind long enough to search for and link similar cognitive networks.

Iskandar S; Baird AD

2013-09-01

386

The public-private divide in household behavior: How far into home can energy guidance reach?  

Energy Technology Data Exchange (ETDEWEB)

Environmental problems in the energy system often originate from everyday activities and choices. Everyday activities in the home are part of the private sphere that can be contested in relation to energy policies. This article discusses the public-private divide in energy policies and how Swedish municipal energy consultants understand the divide. By analyzing the actions of energy consultants and their efforts to influence households, as well as how households perceive this guidance, I will discuss the public-private discourse in relation to energy policy and how this discourse can be a restriction for the energy consultants to reach their full potential. The consultants found it problematic to discuss behavioral issues because they did not know how to relate to people's everyday life activities without intruding on private and personal matters. For the households tailored information and feedback was not perceived as the consultant trespassing in the private sphere. Instead, the householders highlight the possibilities of such mapping. Lessoned learned from Sweden is that state subsidies to local energy consultants is a good way to reach households, but that they need to develop their methods and use more tailored information.

Palm, Jenny, E-mail: jenny.palm@liu.s [Linkoeping University, The Department of Thematic Studies - Technology and Social Change, SE-581 83 Linkoeping (Sweden)

2010-06-15

387

The public-private divide in household behavior. How far into home can energy guidance reach?  

Energy Technology Data Exchange (ETDEWEB)

Environmental problems in the energy system often originate from everyday activities and choices. Everyday activities in the home are part of the private sphere that can be contested in relation to energy policies. This article discusses the public-private divide in energy policies and how Swedish municipal energy consultants understand the divide. By analyzing the actions of energy consultants and their efforts to influence households, as well as how households perceive this guidance, I will discuss the public-private discourse in relation to energy policy and how this discourse can be a restriction for the energy consultants to reach their full potential. The consultants found it problematic to discuss behavioral issues because they did not know how to relate to people's everyday life activities without intruding on private and personal matters. For the households tailored information and feedback was not perceived as the consultant trespassing in the private sphere. Instead, the householders highlight the possibilities of such mapping. Lessoned learned from Sweden is that state subsidies to local energy consultants is a good way to reach households, but that they need to develop their methods and use more tailored information. (author)

Palm, Jenny [Linkoeping University, The Department of Thematic Studies - Technology and Social Change, SE-581 83 Linkoeping (Sweden)

2010-06-15

388

Three-dimensional structure of Drosophila testis tip: the spatial relation between dividing cells.  

UK PubMed Central (United Kingdom)

At the apical tip of Drosophila testis, there is a stem cell niche known as the proliferation center, where the stem cells are maintained by hub cell cluster for the regulation of differentiation and proliferation. Germline stem cells go through mitosis four times from one primary spermatogonial cell to the 16-cell stage before the maturation. The cells derived from the same germline stem cell are located within one cyst, an enclosed system by two cyst cells, and they are connected by the intercellular bridges called ring canals. In this study, the three-dimensional (3D) structure of Drosophila testis tip was reconstructed from serial sections. The size of cells at each stage was compared in volume from the 3D structure. The stages of cells in a cyst could be distinguishable exactly by counting the cells linked with intercellular bridges in 3D-reconstructed structure. The cysts containing the same stage cells appeared in the horizontal plane. Both the germline stem cell directly attached to the hub cell and the spermatogonial cells detached from the hub cell were divided at the almost perpendicular direction to the spermatogonial cell layers. The dividing phase in one cyst was delayed gradually through the cytoplasmic region of intercellular bridge.

Lee KE; Han SS; Jeon H

2013-08-01

389

A divide-down RF source generation system for the Advanced Photon Source  

Energy Technology Data Exchange (ETDEWEB)

A divide-down rf source system has been designed and built at Argonne National Laboratory to provide harmonically-related and phase-locked rf source signals between the APS 352-MHz storage ring and booster synchrotron rf systems and the 9.77-MHz and 117-MHz positron accumulator ring rf systems. The design provides rapid switching capability back to individual rf synthesizers for each one. The system also contains a digital bucket phase shifter for injection bucket selection. Input 352-MHz rf from a master synthesizer is supplied to a VXI-based ECL divider board which produces 117-MHz and 9.77-MHz square-wave outputs. These outputs are passed through low-pass filters to produce pure signals at the required fundamental frequencies. These signals, plus signals at the same frequencies from independent synthesizers, are fed to an interface chassis where source selection is made via local/remote control of coaxial relays. This chassis also produces buffered outputs at each frequency for monitoring and synchronization of ancillary equipment.

Horan, D.; Lenkszus, F.; Laird, R. [Argonne National Lab., IL (United States). Advanced Photon Source

1997-08-01

390

Discovery of Opinion Leader Community Via Multilayer Structure based Time-dividing Approach  

Directory of Open Access Journals (Sweden)

Full Text Available With the advent of web 3.0, social network has become an important way to disclosure and spread the public sentiment. Opinion leaders play an important role in leading the direction of the public opinion. In this paper, due to the structure of the community in the network, we extracted the community by replies of each post in BBS, and we came up with an opinion leader community mining method based on level structure. In this way the communities each other have a better overlap result. Thus, communities can have more relations. Then, we analyzed the revolution of the communities after we got the structure of the opinion leader communities and we put forward a time-dividing method, and divided the whole communities into different pieces based on the character of the post and the duration of the time and we came up with the suitable measurement parameter to get the evolution result of the communities. Finally, experiments prove the efficiency of the opinion leader community mining method and we summarize the properties of the opinion leader community in revolution.

Jingjing Liang; Yan Liu

2013-01-01

391

Nephrotoxicity and oxidative stress of single large dose or two divided doses of gentamicin in rats.  

UK PubMed Central (United Kingdom)

Gentamicin (GS) is a potent antimicrobial exhibiting concentration dependent bacterial killing. A high dose ofgentamicin (10 mg kg(-1)) is required to reach sufficient concentrations in specific fluids as cerebrospinal fluid and to be effective on antibiotics resistant bacteria as well as treatment of acute and dangerous illness. Using a rat model, the renal toxicity and oxidative stress of administering gentamicin (10 mg kg(-1) daily for 7 days) either in a single dose or divided into 2 doses was investigated. The safety of dose regimens was assessed through oxidant-antioxidant parameters as well as renal function tests. Typical renal damage and high oxidative stress were evident in the control group receiving 100 mg kg(-1) gentamicin daily for 7 days. This was verified by high serum urea, uric acid, creatinine as well as increase in the levels of oxidative stress biomarkers as malondialdehyde, NO, total antioxidant capacity and decrease in reduced glutathione level. At any of the used regimen, 10 mg kg(-1) gentamicin did not provide high compromise for renal functions nor significantly increased the oxidative stress and tissue damage. Based on microscopic lesions scores and biochemical analysis, there were no significant differences between single or two divided dosages of gentamicin at dose rate of 10 mg kg(-1) day(-1). Further studies are required for applications in other animals of human subjects.

Kandeel M; Abdelaziz I; Elhabashy N; Hegazy H; Tolba Y

2011-06-01

392

Dividing attention between fovea and periphery: implications for helmet-mounted display design  

Science.gov (United States)

Designers of helmet- and head-mounted displays (HMDs) often assume that monocular devices improve operator performance relative to binocular devices by increasing field of view and by allowing two tasks to be performed simultaneously (one by each eye). To test these assumptions, we implemented a modified useful field of view (UFOV) paradigm in which subjects localized a peripheral target along give meridians within a semicircular region while simultaneously performing a central task. The tasks were either presented to the same eye or to different eyes (simulating a monocular HMD). Because previous research has established age-related changes in the UFOV, the present study investigated the performance of middle-aged observers and compared it to results obtained from young observers in an earlier study. In general, middle-aged observers made more peripheral target localization errors than young observers, indicating an overall constriction of the UFOV. The dependence of localization performance on viewing condition, peripheral distractors and central task, however, was the same for both age groups. Most notably, there was no difference in performance as a function of viewing condition. Thus, these findings do not support the assumption that dividing attention between two eyes allows dual tasks to be performed more efficiently than when attention is divided within the visual field of one eye.

Rohaly, Ann M.; Karsh, Robert

1998-07-01

393

Nephrotoxicity and Oxidative Stress of Single Large Dose or Two Divided Doses of Gentamicin in Rats  

Directory of Open Access Journals (Sweden)

Full Text Available Gentamicin (GS) is a potent antimicrobial exhibiting concentration dependent bacterial killing. A high dose of gentamicin (10 mg kg-1) is required to reach sufficient concentrations in specific fluids as cerebrospinal fluid and to be effective on antibiotics resistant bacteria as well as treatment of acute and dangerous illness. Using a rat model, the renal toxicity and oxidative stress of administering gentamicin (10 mg kg-1 daily for 7 days) either in a single dose or divided into 2 doses was investigated. The safety of dose regimens was assessed through oxidant-antioxidant parameters as well as renal function tests. Typical renal damage and high oxidative stress were evident in the control group receiving 100 mg kg-1 gentamicin daily for 7 days. This was verified by high serum urea, uric acid, creatinine as well as increase in the levels of oxidative stress biomarkers as malondialdehyde, NO, total antioxidant capacity and decrease in reduced glutathione level. At any of the used regimen, 10 mg kg-1 gentamicin did not provide high compromise for renal functions nor significantly increased the oxidative stress and tissue damage. Based on microscopic lesions scores and biochemical analysis, there were no significant differences between single or two divided dosages of gentamicin at dose rate of 10 mg kg-1 day-1. Further studies are required for applications in other animals of human subjects.

Mahmoud Kandeel; Iman Abdelaziz; Nagwan Elhabashy; Hanaa Hegazy; Yasmin Tolba

2011-01-01

394

A study on how to divide and recodify the atomic energy act and its related regulations  

International Nuclear Information System (INIS)

As a part of big project named 'streamlining and optimization of nuclear safety regulatory system', this report focuses on how to divide and recodify the Atomic Energy Act and its related regulations. Follow the first chapter of preface, the second chapter shows the systemic problems of regulation of current AEA and out strategy to reform and re-systematize it. This report concludes that the regulations of the current AEA need to be divided in three parts, i.e. the presidential regulations of FWAAE, NNA and RPA and the ministerial regulation of AEA in two part, i.e. that of NNA and RPA. Then the problems of current regulations of AEA are pointed out and the alternative regulations of FWAAE and NNA are persented in the third and forth chapter respectively. In the fifth chapter RPA is persented. And finally the legal character of several nuclear safety standards is estimated. Concerning nuclear safety or technology standards, those issued by Minister of Science and Technology (MST) empowered by law or its regulation is obviously forceful as a law. But the standards made by KINS to meet the tasks entrusted to KINS by MST is only conditionally forceful as a law, that is, on the condition that law or regulation empowered the chief of KINS to make nuclear safety and/or technology standards

2003-01-01

395

Force to divide: structural and mechanical requirements for actomyosin ring contraction.  

UK PubMed Central (United Kingdom)

One of the unresolved questions in the field of cell division is how the actomyosin cytoskeleton remains structurally organized while generating the contractile force to divide one cell into two. In analogy to the actomyosin-based force production mechanism in striated muscle, it was originally proposed that contractile stress in the actomyosin ring is generated via a sliding filament mechanism within an organized sarcomere-like array. However, over the last 30 years, ultrastructural and functional studies have noted important distinctions between cytokinetic structures in dividing cells and muscle sarcomeres. Myosin-II motor activity is not always required, and there is evidence that actin depolymerization contributes to contraction. In this Review, the architecture and contractile dynamics of the actomyosin ring at the cell division plane will be discussed. We will report the interdisciplinary advances in the field as well as their integration into a mechanistic understanding of contraction in cell division and in other biological processes that rely on an actomyosin-based force-generating system.

Mendes Pinto I; Rubinstein B; Li R

2013-08-01

396

Water watch  

Energy Technology Data Exchange (ETDEWEB)

This issue of [open quotes]Water Watch[close quotes] focuses on soil moisture and fall streamflow. A map depicts soil moisture conditions in the US through early October. The analysis is based on reports and data provided by the National Weather Service Office of Hydrology, the US Department of Agriculture, the Bureau of Reclamation, the Soil Conservation Service, the California Department of Water Resources, and the US Geological Survey. Ninety-day outlooks are through November 1992. For purposed of reporting, the US is divided into six regions as indicated on a figure and in a table. The data presented in the table, the Hydropower Generation Report, can be used to observe how weather conditions affected hydro generation in September.

Gruber, N. (C.T. Male Associates, P.C., Syracuse, NY (United States))

1992-12-01

397

The digital divide in Internet information searching: A double-hurdle model analysis of household data from Vermont  

Digital Repository Infrastructure Vision for European Research (DRIVER)

While most studies on the digital divide in the United States focus on disparities in access to computers and the Internet, this study examines the digital divide in Internet information searching. With data from 476 Vermont households surveyed in 2009, a double-hurdle model is used to identify the ...

Guangxuan Zhang; University of Vermont; Qingbin Wang; Jane Kolodinsky

398

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

Directory of Open Access Journals (Sweden)

Full Text Available 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 help to bridge this divide (Market Dynamics and Public Policies). Then, focussing on the second level of digital divide (usages divide) we analyse why this seems to be the main problem nowadays in Europe. Finally, a third level of digital divide concerns the performance of ICT in education. We give some possible explanations for the productivity paradox which is observed in European higher education.Section two is devoted to the explanation of the diversity of usage of ICT between countries and universities. ICT allows different contextualisation and adaptation to the local context. Universities are developing several digital trajectories and instead of benchmarking universities we look at the explanations for this diversity. Two key elements were explored here: competition strategy of universities and students' attitudes towards the technologies.

Adel Ben Youssef; Ludovic Ragni

2008-01-01

399

Impact of the digital divide on information literacy training in a higher education context  

Directory of Open Access Journals (Sweden)

Full Text Available This paper reports on a master’s study undertaken to investigate the impact of the digital divide on information literacy(IL) training of Extended Curriculum Programme (ECP) students at the Durban University of Technology (DUT). Since1994 the demographics of higher education institutions in South Africa have changed. Today these institutions compriseheterogeneous groups of students, by race, economic background, digital background, etc. and consequently with differentlevels of literacy, information and otherwise. The problem that this study addressed was the impact of having both digitallyadvantaged and digitally disadvantaged students in the same information literacy classroom, expecting them to reachlearning outcomes without frustrating students from either group. The objective of the study was to investigate the impactof the digital divide on IL training of ECP students at the DUT and to recommend guidelines for teaching and learning of ILthat would accommodate both digitally advantaged and digitally disadvantaged students. The study employed a mixedmethod approach in its research design. Data was collected from ECP students (of 2010) by means of a questionnaire; aninterview schedule was used to collect data from Subject Librarians involved in teaching the IL module to ECP students; aseparate interview schedule was used to collect data from the ECP Coordinator. Qualitative and quantitative datacollected were prepared for analysis by means of content analysis and numerical coding, respectively and then subjectedto statistical analysis via SPSS, which produced percentage and frequency distributions to ascertain findings. The findingsof the study revealed that the digital divide does impact on IL training in ways such as: slowing down the progress of ILlessons; basic computer skills need to be taught in the IL classroom; and that digitally disadvantaged students find itdifficult to follow online lessons while advantaged students already have the expertise to access online information. Basedon these findings the study recommended computer literacy training should precede IL training and that various creativeteaching and learning methods such as group work, online tutorials, games and interactive websites should beincorporated into IL education to accommodate both digitally advantaged and digitally disadvantaged students in the ILclassroom.

Segarani Naidoo; Jaya Raju

2012-01-01

400

Modeling photovoltaic-powered solar water heating systems using TRNSYS  

Energy Technology Data Exchange (ETDEWEB)

A photovoltaic-powered solar domestic hot water (PV-SDHW) system uses PV cells to generate electrical energy which is dissipated in several resistive heating elements within a water storage tank. A microprocessor controller selects the combination of resistors which maximizes PV array power output with respect to the incident solar radiation. Two fully-instrumented prototype installations are currently operating, one at the National Institute of Standards and Technology (NIST) in Gaithersburg, MD and the other at the Florida Solar Energy Center (FSEC) in Cocoa, FL. Both systems have a dual-tank design consisting of a PV-connected preheat tank delivering heated water to a utility grid-connected auxiliary tank for any additional heating. Simulation models of these systems have been constructed with the TRNSYS program and validated with experimental data. This paper describes the PV-SDHW system models and presents comparisons of measured and TRNSYS-predicted performance results.

Williams, P.M.; Klein, S.A.; Beckman, W.A.; Mitchell, J.W. [Univ. of Wisconsin, Madison, WI (United States). Solar Energy Lab.

1997-12-31

 
 
 
 
401

Information technologies and the evolution of the digital divide in Mexico: a public policy approach  

Directory of Open Access Journals (Sweden)

Full Text Available The rapid diffusion of Information Technologies (ITs) has noticeably influenced the ability of societies to stimulate economic growth and development. Among these technologies, the Internet stands out due to its contribution to the advancement of education, learning and knowledge. Hence, the commitment of some developing nations like Mexico to the diffusion of the Internet has become a top issue in their policy agendas. However, the country's promotion of this technology has undergone a number of setbacks, mainly due to a misinterpretation of the factors causing the so-called 'digital divide'. Hence, the purpose of this paper is to analyze the rationale for governmental intervention regarding the diffusion of the Internet in Mexico.

Humberto Merritt

2011-01-01

402

Crossing the phantom divide with k-essence in brane-worlds  

CERN Multimedia

We examine a linear k-essence field model on a brane universe with a spatially flat Friedmann-Robertson-Walker (FRW) spacetime and a nonzero cosmological constant $\\Lambda_{4}$. We find that the phantom divide line $w_{eff}=-1$ can be crossed when the bare density becomes negative definite. There exist several types of brane-worlds which could match with the observational data. In the high energy regime the effective equation of state has a resemblance to a modified Chaplygin gas while in the low energy regime becomes linear. We discus the energy conditions on the brane using a pressure and/or effective energy density and show that the crossing is carry out in a continuous manner when the weak energy condition is violated.

Chimento, Luis P; Richarte, Martin G

2009-01-01

403

Divide and Conquer: A Novel Approach to the Design of Heterogeneous Multi-Robot Systems  

UK PubMed Central (United Kingdom)

In this report, we investigate a telling lacuna in the research of multi-robotsystems, and propose a research agenda to fill this gap of knowledge. We arguethat the embryonic work on heterogeneous multi-robot systems fails to anticipatethe practical constraints of robot design, and the scaling up of designs to morecomplex task domains. Further, our investigations of the literature reveal thatthe design of heterogeneous multi-robot systems can be viewed as a non-trivial,multivariate optimization problem. This realization leads us to conclude that anevolutionary approach to robot group design would be an ideal avenue for futureresearch."While these do labour for their own preferment,Behoves it us to labour for the realm."--- King Henry IV, Shakespeare1 IntroductionThe history of robotics research can be roughly divided into two eras. In the first era, workfocussed on internal, high-level symbol processing, and there was minimal consideration ofinterfacing with th...

Josh Bongard

404

1-D elastic waveform inversion: A divide-and-conquer approach  

UK PubMed Central (United Kingdom)

Subsurface rock properties are manifested in seismicrecords as variations in traveltimes, amplitudes, andwaveforms. It is commonly acknowledged that traveltimesare sensitive to the long wavelength part of thevelocity, whereas amplitudes are sensitive to the shortwavelength part of the velocity. The inherent sensitivityof seismic velocity at different wavelengths suggests anapproach that decomposes the waveform data into traveltimeand amplitude components. Therefore we proposea divide-and-conquer approach to the elastic waveforminversion problem. We first estimate the smoothlyvarying background velocity from the traveltime and therapidly changing perturbations from the amplitude byamplitude variation with offset (AVO) inversion basedon linearized reflection coefficient. Thenwe combine theperturbation with the background to obtain a startingmodel to be used in the final waveform inversion thatmodels all converted waves and internal multiples assuminga ...

Ganyuan Xia; Mrinal K. Sen; Paul L. Stoffa

405

Digital Divide: How Do Home Internet Access and Parental Support Affect Student Outcomes?  

Directory of Open Access Journals (Sweden)

Full Text Available This study examined the relationship between home Internet access/parental support and student outcomes. Survey data were collected from 1,576 middle school students in China. Data were analyzed using descriptive analysis, independent-samples T-test, and regression analysis. Results indicate that students who had home Internet access reported higher scores than those without home Internet on all three dimensions: Computer and Internet self-efficacy, Attitudes towards technology and Developmental outcomes. Home Internet access and parental support were significantly positively associated with technology self-efficacy, interest in technology, perceived importance of the Internet, and perceived impact of the Internet on learning. Findings from this study have significant implications for research and practice on how to narrow down the digital divide.

Jing Lei; Jingye Zhou

2012-01-01

406

Improvement of the irradiation performance of irradiators by dividing a gamma-ray source  

Energy Technology Data Exchange (ETDEWEB)

To improve the irradiation performance of vessel- and conveyor-type irradiators for efficient and uniform irradiation, a method for dividing a radiation source into two elements and putting the optimum source interval between them is proposed. With the increase in the source interval, the maximum dose rate in an irradiated material decreases slowly, while the minimum dose rate in the material and efficiency of the irradiation increase sharply and become maximum at the optimum source interval. Thereafter, the minimum dose rate decreases sharply. Consequently, the best irradiation efficiency and dose rate uniformity of the irradiation are obtained by putting the optimum interval between the source elements. The optimum source intervals and approximate formula are derived to make the optimum design of the source easy. (author).

Hoshi, Tatsuo (Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment)

1991-04-01

407

Stickiness in Hamiltonian systems: from sharply divided to hierarchical phase space  

CERN Multimedia

We investigate the dynamics of chaotic trajectories in simple yet physically important Hamiltonian systems with non-hierarchical borders between regular and chaotic regions with positive measures. We show that the stickiness to the border of the regular regions in systems with such a sharply divided phase space occurs through one-parameter families of marginally unstable periodic orbits and is characterized by an exponent \\gamma= 2 for the asymptotic power-law decay of the distribution of recurrence times. Generic perturbations lead to systems with hierarchical phase space, where the stickiness is apparently enhanced due to the presence of infinitely many regular islands and Cantori. In this case, we show that the distribution of recurrence times can be composed of a sum of exponentials or a sum of power-laws, depending on the relative contribution of the primary and secondary structures of the hierarchy. Numerical verification of our main results are provided for area-preserving maps, mushroom billiards, and...

Altmann, E G; Kantz, H; Altmann, Eduardo G.; Motter, Adilson E.; Kantz, Holger

2006-01-01

408

A scalable divide-and-conquer parallel algorithm for finite state automata and its applications  

Energy Technology Data Exchange (ETDEWEB)

Our algorithm is a hybrid of two divide-and-conquer (DC) algorithms. A problem is first compressed to one of smaller size (measured by input length), the compressed problem is computed, and the solution is expanded. An unbalanced DC algorithm is used in the compression and expansion, while a balanced DC algorithm is used in the computation. This approach effectively reduces the computation and communication cost by a factor of n/p, where n is input length, and p number of processors. The time complexity is 0(n/p) for n {much_gt} p, hence the algorithm is scalable to both n and p. Benchmarks on the MasPar MP-2 and applications are presented.

Mou, Z.G.; Ficici, S.G.

1995-12-01

409

Divided attention can enhance memory encoding: the attentional boost effect in implicit memory.  

UK PubMed Central (United Kingdom)

Distraction during encoding has long been known to disrupt later memory performance. Contrary to this long-standing result, we show that detecting an infrequent target in a dual-task paradigm actually improves memory encoding for a concurrently presented word, above and beyond the performance reached in the full-attention condition. This absolute facilitation was obtained in 2 perceptual implicit tasks (lexical decision and word fragment completion) but not in a conceptual implicit task (semantic classification). In the case of recognition memory, the facilitation was relative, bringing accuracy in the divided attention condition up to the level of accuracy in the full attention condition. The findings follow from the hypothesis that the attentional boost effect reflects enhanced visual encoding of the study stimulus consequent to the transient orienting response to the dual-task target.

Spataro P; Mulligan NW; Rossi-Arnaud C

2013-07-01

410

Divided attention can enhance memory encoding: the attentional boost effect in implicit memory.  

Science.gov (United States)

Distraction during encoding has long been known to disrupt later memory performance. Contrary to this long-standing result, we show that detecting an infrequent target in a dual-task paradigm actually improves memory encoding for a concurrently presented word, above and beyond the performance reached in the full-attention condition. This absolute facilitation was obtained in 2 perceptual implicit tasks (lexical decision and word fragment completion) but not in a conceptual implicit task (semantic classification). In the case of recognition memory, the facilitation was relative, bringing accuracy in the divided attention condition up to the level of accuracy in the full attention condition. The findings follow from the hypothesis that the attentional boost effect reflects enhanced visual encoding of the study stimulus consequent to the transient orienting response to the dual-task target. PMID:23356238

Spataro, Pietro; Mulligan, Neil W; Rossi-Arnaud, Clelia

2013-01-28

411

A Unified Superfast Divide-and-Conquer Algorithm for Structured Matrices Over Fields  

UK PubMed Central (United Kingdom)

We propose a superfast divide-and-conquer algorithm that uses 2n - 2 random parameters, O(n) memory space and O((n log² n) log log n) operations in a fixed arbitrary field in order to compute the rank and a basis for the null space of a structured n × n matrix X given with its short generator, as well as to solve a linear system Xy = b or to determine its inconsistency. If rank X = n, the algorithm also computes det X and a short generator of X Gamma1 . The cost bounds cover correctness verification for the output but not the cost of the generation of random parameters. The algorithm gives a unified treatment of various classes of structured matrices including ones of Toeplitz, Hankel, Vandermonde and Cauchy types.

Victor Y. Pan

412

Asteroid Lightcurve Analysis at the Palmer Divide Observatory: 2012 September - 2013 January  

Science.gov (United States)

Lightcurves for 40 asteroids were obtained at the Palmer Divide Observatory (PDO) from 2012 September to 2013 January: 495 Eulalia, 1694 Kaiser, 2001 Einstein, 3086 Kalbaugh, 3635 Kreutz, 5806 Archieroy, 6310 Jankonke, 6447 Terrycole, 6744 Komoda, 7086 Bopp, 7560 Spudis, 8325 Trigo-Rodriguez, 11149 Tateshina, 11709 Eudoxos, (13245) 1998 MM19, (13573) 1993 FZ18, 14395 Tommorgan, 15434 Mittal, (17657) 1996 VO4, (22013) 1999 XO89, (26916) 1996 RR2, 27776 Cortland, (30878) 1992 GQ, (30981) 1995 SJ4, (31831) 1999 YL, (32626) 2001 RX64, (51371) 2000 XF15, 55844 Bicak, (55854) 1996 VS1, (63440) 2001 MD30, (66832) 1999 UE45, (70927) 1999 VX210, (72675) 2001 FP54, (86388) 2000 AT60, (90988) 1997 XS13, (123937) 2001 EX16, (136017) 2002 VH74, (192683) 1999 SO27, (330825) 2008 XE3, and 2012 TC4. Based on data and analysis in 2012 for 27776 Cortland, the previously reported period from 2009 has been revised.

Warner, Brian D.

2013-04-01

413

Correction of divided renal clearance studies - a comparison of renal depths  

Energy Technology Data Exchange (ETDEWEB)

Differences in renal depth can be determined by ultrasound investigation and profile measurements of a digitalised lateral renal scintigram. Both methods are simple and equally suitable for determining renal depth. Amongst 42 patients there were three in whom there were considerable differences in renal depth in the supine position, and seven patients with a similar difference when they were sitting upright. A correction for renal depth resulted in a reduction in the error obtained on divided renal clearance studies. Measurements on a renal phantom designed to obtain the half-value layer of /sup 131/I and /sup 99/sup(m)Tc provide quantitative data for the correction. The correction is less easily carried out when renal depth differences occur in the sitting position than when the patient was lying down. Determination of renal depth when the patient is lying down can be confined to individual cases which can be selected from the total clinical material.

Pressler, M.

1980-06-01

414

A divide-and-inner product parallel algorithm for polynomial evaluation  

Energy Technology Data Exchange (ETDEWEB)

In this paper, a divide-and-inner product parallel algorithm for evaluating a polynomial of degree N (N+1=KL) on a MIMD computer is presented. It needs 2K + log{sub 2}L steps to evaluate a polynomial of degree N in parallel on L+1 processors (L{<=}2K-2log{sub 2}K) which is a decrease of log{sub 2}L steps as compared with the L-order Homer`s method, and which is a decrease of (2log{sub 2}L){sup 1/2} steps as compared with the some MIMD algorithms. The new algorithm is simple in structure and easy to be realized.

Hu, Jie; Li, Lei [Aomori Univ. (Japan); Nakamura, Tadao [Tohoku Univ., Sendai (Japan)

1994-12-31

415

Distributed Memory Programming on Many-Cores : A Case Study Using Eden Divide-&-Conquer Skeletons  

DEFF Research Database (Denmark)

Eden is a parallel extension of the lazy functional language Haskell providing dynamic process creation and automatic data exchange. As a Haskell extension, Eden takes a high-level approach to parallel programming and thereby simplifies parallel program development. The current implementation is tailored to networks of workstations. Recent work has shown that this implementation shows surprisingly competitive performance on many-core machines, compared to dedicated shared-memory implementations of parallel Haskell. In the paper we describe a case study with different Eden divide-and-conquer skeletons. We analyse their performance comparing example applications implemented using these Eden skeletons against parallel Haskell implementations using shared memory on many-core machines

Berthold, Jost; Dieterle, Mischa

2009-01-01

416

Efficient cache oblivious algorithms for randomized divide-and-conquer on the multicore model  

CERN Document Server

In this paper we present randomized algorithms for sorting and convex hull that achieves optimal performance (for speed-up and cache misses) on the multicore model with private cache model. Our algorithms are cache oblivious and generalize the randomized divide and conquer strategy given by Reischuk and Reif and Sen. Although the approach yielded optimal speed-up in the PRAM model, we require additional techniques to optimize cache-misses in an oblivious setting. Under a mild assumption on input and number of processors our algorithm will have optimal time and cache misses with high probability. Although similar results have been obtained recently for sorting, we feel that our approach is simpler and general and we apply it to obtain an optimal parallel algorithm for 3D convex hulls with similar bounds. We also present a simple randomized processor allocation technique without the explicit knowledge of the number of processors that is likely to find additional applications in resource oblivious environments.

Sharma, Neeraj

2012-01-01

417

A multiple divide-and-conquer (MDC) algorithm for optimal alignments in linear space  

Energy Technology Data Exchange (ETDEWEB)

Dynamic programming algorithms are often used to find the similarities of sequences as well as to deliver the actual alignment of two sequences. Two kinds of alignments are used to compare sequences: local alignments and global alignments. The local alignments attempt to locate conserved regions, while the global alignments identify overall relationship between two sequences. While dynamic programming algorithms are relatively time consuming, the space required is often the limiting factor when aligning long sequences. A linear space algorithm for computing maximal common subsequences, proposed by Hirschberg, was applied by Myers and Miller to deliver optimal alignments in linear space. The authors have improved the Myers and Miller algorithm by introducing a multiple divide and conquer technique that reduces the algorithm`s running time while maintaining its linear space property. Efficient sequence alignment algorithms have been an active topic in computational biology.

Guan, X.; Uberbacher, E.C.

1994-06-01

418

Long Division Unites or Long Union Divides: a Model for Social Network Evolution  

Science.gov (United States)

A remarkable phenomenon in the time evolution of many networks such as cultural, political, national and economic systems is the recurrent transition between the states of union and the division of nodes. We propose a phenomenological modeling, inspired by the maxim “long union divides and long division unites" to investigate the evolutionary characters of these networks composed of the entities whose behaviors are dominated by these two events. The nodes are endowed with quantities such as identity, ingredient, richness (power), openness (connections), age, distance, and interaction, which determine collectively the evolution in a probabilistic way. Depending on a tunable parameter, the time evolution of this model is mainly an alternative domination of union or division state, with a possible state of final union dominated by one single node.

Jiang, Jian; Wang, Ru; Pezeril, Michel; Wang Qiuping, Alexandre

2013-03-01

419

Discriminator/Divider module for anode readout of the TOPAZ Inner Drift Chamber  

International Nuclear Information System (INIS)

The Discriminator/Divider module for anode readout of the TOPAZ Inner Drift Chamber has been developed. A single-span wide-CAMAC module can process 32-channel differential signals from the anode preamplifiers. The module provides two kinds of output signals; one is the ECL differential signal for the drift time measurement with the LeCroy TDC system and the other is the TTL logic signal for triggering with the R? Line Search module. Threshold levels of discriminators can be controlled through the standard CAMAC data way in the input voltage range from 10 mV to 500 mV. Test pulse outputs with variable amplitudes and ±5.2 V power lines are also provided for the preamplifier cards. (author).

1988-01-01

420

Design and Modeling of Symmetric Three Branch Polymer Planar Optical Power Dividers  

Directory of Open Access Journals (Sweden)

Full Text Available Two types of polymer-based three-branch symmetric planar optical power dividers (splitters) were designed, multimode interference (MMI) splitter and triangular shape-spacing splitter. By means of modeling the real structures were simulated as made of Epoxy Novolak Resin on silicon substrate, with silica buffer layer and polymethylmethacrylate as protection cover layer. The design of polymer waveguide structure was done by Beam Propagation Method. After comparing properties of both types of the splitters we have demonstrated that our new polymer based triangular shaped splitter can work simultaneously in broader spectrum, the only condition would be that the waveguides are single-mode guiding. It practically means that, what concerns communication wavelengths, it can on principle simultaneously operate at two mainly used wavelengths, 1310 and 1550 nm.

V. Prajzler; H. Tuma; J. Spirkova; V. Jerabek

2013-01-01

 
 
 
 
421

Study of divided converter catalytic system satisfying quick warm up and high heat resistance  

Energy Technology Data Exchange (ETDEWEB)

Catalyst specifications and converter layouts were studied to identify the high conversion performance under various in-use driving conditions, high mileage intervals and extended life cycle. The effects of volumes, configuration, selection and loading distribution of precious metals, additive components and substrate type for catalyst were studied on engine dynamometers and vehicle tests to optimize a catalyst converter system. Moreover, model gas experiments were conducted to analyze deterioration mechanisms and conversion characteristics of catalysts. As a result, the concept of a divided catalyst converter system, which provides separate functions for a close-coupled and an under-floor catalyst, was found to be effective for the future exhaust system. For reducing HC emissions, the close-coupled catalyst should warm up quickly and resist a high temperature. The under-floor catalyst, located at a rather low temperature position, is durable and maintains high NOx conversion.

Takada, Toshihiro; Hirayama, Hiroshi; Itoh, Takaaki; Yaegashi, Takehisa [Toyota Motor Corp., Aichi (Japan)

1996-09-01

422

Nonvolatile reconfigurable current divider based on spin extraction in lateral ferromagnet/nonmagnet transport structures  

Science.gov (United States)

We demonstrate a device concept for a lateral spin-transport structure consisting of ferromagnetic (Co2FeSi) stripes on a nonmagnetic (n-GaAs) transport channel. The basic building block of the device consists of a local spin valve which utilizes spin extraction instead of injection at the ferromagnetic contact stripes for its fundamental operation principle. An extended device comprises an array of such spin valves in which the spin polarization in the transport channel results from a cascade of spin extraction events. The achieved functionality can be described in terms of a nonvolatile reconfigurable current divider. We show that for m ferromagnetic contacts, 2m-1 electrical output levels can occur, where each output level corresponds to a particular magnetization configuration of the entire stripe array.

Manzke, Yori; Farshchi, Rouin; Bruski, Pawel; Herfort, Jens; Ramsteiner, Manfred

2013-04-01

423

Block-adaptive quantum mechanics: an adaptive divide-and-conquer approach to interactive quantum chemistry.  

UK PubMed Central (United Kingdom)

We present a novel Block-Adaptive Quantum Mechanics (BAQM) approach to interactive quantum chemistry. Although quantum chemistry models are known to be computationally demanding, we achieve interactive rates by focusing computational resources on the most active parts of the system. BAQM is based on a divide-and-conquer technique and constrains some nucleus positions and some electronic degrees of freedom on the fly to simplify the simulation. As a result, each time step may be performed significantly faster, which in turn may accelerate attraction to the neighboring local minima. By applying our approach to the nonself-consistent Atom Superposition and Electron Delocalization Molecular Orbital theory, we demonstrate interactive rates and efficient virtual prototyping for systems containing more than a thousand of atoms on a standard desktop computer.

Bosson M; Grudinin S; Redon S

2013-03-01

424

Block-adaptive quantum mechanics: an adaptive divide-and-conquer approach to interactive quantum chemistry.  

Science.gov (United States)

We present a novel Block-Adaptive Quantum Mechanics (BAQM) approach to interactive quantum chemistry. Although quantum chemistry models are known to be computationally demanding, we achieve interactive rates by focusing computational resources on the most active parts of the system. BAQM is based on a divide-and-conquer technique and constrains some nucleus positions and some electronic degrees of freedom on the fly to simplify the simulation. As a result, each time step may be performed significantly faster, which in turn may accelerate attraction to the neighboring local minima. By applying our approach to the nonself-consistent Atom Superposition and Electron Delocalization Molecular Orbital theory, we demonstrate interactive rates and efficient virtual prototyping for systems containing more than a thousand of atoms on a standard desktop computer. PMID:23108532

Bosson, Maël; Grudinin, Sergei; Redon, Stephane

2012-10-29

425

Development and Field Evaluation of a Rotary Hydraulic Divider for Canola Harvesting  

Directory of Open Access Journals (Sweden)

Full Text Available Oil seed rape is an important non-cereal crop used mainly for edible oil production. Canola pods are fragile and its branches are twisted together at harvesting time. Harvesting with a conventional combine can pull off twisted branches and cause appreciable losses in the vicinity of divider at combine header. In this study, a hydraulic rotary divider was designed and developed to separate twisted pods and reduce the grain loss. The device is made up of two cylinders and a number of fingers, the cylinders rotate in opposite direction and fingers move in and out through holes on cylinder walls. The assembly was expected to separate the twisted pods and reduce grain loss. A hydraulic motor driven by combine hydraulic system was used to rotate the separating cylinders. The separating assembly was installed on righthand side of the combine harvester header. A split-plot experiment was used to evaluate the performance of the unit. Field tests were carried out at combine forward speed of 1.5 kmh-1. Variables were: cylinders rotary speed in three levels (50, 75 and 100 rpm), the number of fingers in three levels (16, 12 and 8), and the tests were conducted with and without combine reel. Two different positions of finger protrusion were also considered in field tests. The results were compared with those of a conventional combine header. The results show that the medium rotational speed (75 rpm) exhibited lowest seed loss. Furthermore, as the number of fingers increased, the seed loss tended to decrease. The seed loss also decreased in the presence of combine reel. Also, findings showed there is no significant difference between the two protrusions trajectories of fingers. A twenty percent decrease in seed loss was observed at rotary speed of 75 rpm and number of fingers of 16 in the presence of combine reel.

Morteza por; Raoufat; Kamgar

2009-01-01

426

Cacao Husk-Derived Water-Soluble, Dietary Fiber, Process For Its Production, Foods and Beverages Containing It And Methods For Their Preparation  

UK PubMed Central (United Kingdom)

It is an object of the invention to provide water-soluble dietary fiber obtained by hot water extraction from cacao husks, and to use the water-soluble dietary fiber for addition to acidic protein foods such as milk component-containing beverages, dispersion stabilizers for chocolate beverages and the like, coating agents with improved coatability, age resistors for starch-containing food products, and shelf-life extenders for foods and beverages which continue to maintain their microbiostatic properties even when added only in small amounts.

NAKAMURA AKIHIRO; YOSHIDA RYUJI; MAEDA HIROKAZU; NAGAOKA SHUSHI

427

Cacao husk-origin water soluble dietary fiber, process for producing the same, foods and drinks with the use thereof and process for producing the same  

UK PubMed Central (United Kingdom)

It is an object of the invention to provide water-soluble dietary fiber obtained by hot water extraction from cacao husks, and to use the water-soluble dietary fiber for addition to acidic protein foods such as milk component-containing beverages, dispersion stabilizers for chocolate beverages and the like, coating agents with improved coatability, age resistors for starch-containing food products, and shelf-life extenders for foods and beverages which continue to maintain their microbiostatic properties even when added only in small amounts.

NAKAMURA AKIHIRO; YOSHIDA RYUJI; MAEDA HIROKAZU; NAGAOKA SHUSHI

428

CACAO HUSK-ORIGIN WATER SOLUBLE DIETARY FIBER, PROCESS FOR PRODUCING THE SAME, FOODS AND DRINKS WITH THE USE THEREOF AND PROCESS FOR PRODUCING THE SAME  

UK PubMed Central (United Kingdom)

It is an object of the invention to provide water-soluble dietary fiber obtained by hot water extraction from cacao husks, and to use the water-soluble dietary fiber for addition to acidic protein foods such as milk component-containing beverages, dispersion stabilizers for chocolate beverages and the like, coating agents with improved coatability, age resistors for starch-containing food products, and shelf-life extenders for foods and beverages which continue to maintain their microbiostatic properties even when added only in small amounts.

NAKAMURA Akihiro c/o Fuji Oil Company Limited; YOSHIDA Ryuji c/o Fuji Oil Company Limited; MAEDA Hirokazu c/o Fuji Oil Company Limited; NAGAOKA Shushi c/o Fuji Oil Company Limited

429

The potential, limitations, and challenges of divide and conquer quantum electronic structure calculations on energetic materials.  

Energy Technology Data Exchange (ETDEWEB)

High explosives are an important class of energetic materials used in many weapons applications. Even with modern computers, the simulation of the dynamic chemical reactions and energy release is exceedingly challenging. While the scale of the detonation process may be macroscopic, the dynamic bond breaking responsible for the explosive release of energy is fundamentally quantum mechanical. Thus, any method that does not adequately describe bonding is destined to lack predictive capability on some level. Performing quantum mechanics calculations on systems with more than dozens of atoms is a gargantuan task, and severe approximation schemes must be employed in practical calculations. We have developed and tested a divide and conquer (DnC) scheme to obtain total energies, forces, and harmonic frequencies within semi-empirical quantum mechanics. The method is intended as an approximate but faster solution to the full problem and is possible due to the sparsity of the density matrix in many applications. The resulting total energy calculation scales linearly as the number of subsystems, and the method provides a path-forward to quantum mechanical simulations of millions of atoms.

Tucker, Jon R.; Magyar, Rudolph J.

2012-02-01