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1

Voltage Divider  

Science.gov (United States)

This voltage divider produces an output voltage, Vo, that is proportional to the input voltage, Vs. The output voltage is measured using a voltmeter. The input voltage is the voltage of the voltage source. The constant of proportionality is called the gain of the voltage divider. The value of the gain of the voltage divider is determined by the resistances, R1 and R2, of the two resistors that comprise the voltage divider.

2008-11-24

2

The Vivitron resistors  

International Nuclear Information System (INIS)

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

3

Voltage-Controlled Floating Resistor Using DDCC  

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents a new simple configuration to realize the voltage-controlled floating resistor, which is suitable for integrated circuit implementation. The proposed resistor is composed of three main components: MOS transistor operating in the non-saturation region, DDCC, and MOS voltage divider. The MOS transistor operating in the non-saturation region is used to configure a floating linear resistor. The DDCC and the MOS transistor voltage divider are used for canceling the nonlinear component term of MOS transistor in the non-saturation region to obtain a linear current/voltage relationship. The DDCC is employed to provide a simple summer of the circuit. This circuit offers an ease for realizing the voltage divider circuit and the temperature effect that includes in term of threshold voltage can be compensated. The proposed configuration employs only 16 MOS transistors. The performances of the proposed circuit are simulated with PSPICE to confirm the presented theory.

M. Kumngern

2011-04-01

4

Babylonian resistor networks  

International Nuclear Information System (INIS)

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

5

A Novel Voltage Divider Circuit  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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.

Selvam, K. C.; Latha, S.

2012-01-01

6

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

2011-10-01

7

Application to printed resistors  

International Nuclear Information System (INIS)

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

8

Using Ohm's Law to Build a Voltage Divider  

Science.gov (United States)

In this activity, learners apply Ohmâs Law to construct voltage divider circuits. Learners discover how to read resistor codes and calculate resistor values. Using breadboards, learners build voltage dividers and predict and measure output voltage values. Learners are given the electrical requirements for an LED, and are then challenged to design and verify a voltage divider circuit to illuminate it.

Ieee

2014-05-23

9

Remote Experiments in Resistor Measurement  

Directory of Open Access Journals (Sweden)

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

Popescu Viorel

2009-10-01

10

Remote Experiments in Resistor Measurement  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Popescu Viorel; B?b?i?? Mircea; Popovici Adrian; Lascu Dan; Negoi?escu Dan; Lascu Mihaela

2009-01-01

11

Discrete/PWM Ballast-Resistor Controller  

Science.gov (United States)

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

King, Roger J.

1994-01-01

12

High-voltage high-power resistive divider for TFTR neutral-beam power supply  

International Nuclear Information System (INIS)

The neutral-beam source at the Tokamak Fusion Test Reactor (TFTR) requires a voltage divider to supply the gradient grid. The requirements are simple, but stringent: it must dissipate 576 kW of peak power at 120 kV dc. Average power is 19.2 kW. A special resistive divider, indirectly water cooled, has been successfully developed for this purpose. The divider is unusually large physically, weighing 1290 kg when filled, and its cooling system is believed to be unique, conferring unusual advantages. The divider consists of an array of 9000 commercial resistors immersed in a plastic tank of inert fluid. The resistors are cooled by subcooled-pool boiling at their surfaces, and the fluid is vigorously circulated by natural convection. A fluid-to-water heat exchanger above the resistors removes the deposited energy and limits the average temperature of the system. The tank is covered by a constant-pressure diaphragm seal. The heat capacity of the system reliably averages the pulse power, and there are no pumps or other moving parts. Operation of the system, which is intrinsically self-regulating, is relatively unaffected by leakage or noncondensible gas

13

Ground-water modeling of pumping effects near regional ground-water divides and river/aquifer systems - Results and implications of numerical experiments  

Science.gov (United States)

Agreements between United States governors and Canadian territorial premiers establish water-management principles and a framework for protecting Great Lakes waters, including ground water, from diversion and consumptive uses. The issue of ground-water diversions out of the Great Lakes Basin by large-scale pumping near the divides has been raised. Two scenario models, in which regional ground-water flow models represent major aquifers in the Great Lakes region, were used to assess the effect of pumping near ground-water divides. The regional carbonate aquifer model was a generalized model representing northwestern Ohio and northeastern Indiana; the regional sandstone aquifer model used an existing calibrated ground-water flow model for southeastern Wisconsin. Various well locations and pumping rates were examined. Although the two models have different frameworks and boundary conditions, results of the models were similar. There was significant diversion of ground water across ground-water divides due to pumping within 10 miles of the divides. In the regional carbonate aquifer model, the percentage of pumped water crossing the divide ranges from about 20 percent for a well 10 miles from the divide to about 50 percent for a well adjacent to the divide. In the regional sandstone aquifer model, the percentages range from about 30 percent for a well 10 miles from the divide to about 50 percent for a well adjacent to the divide; when pumping on the west side of the divide, within 5 mi of the predevelopment divide, results in at least 10 percent of the water being diverted from the east side of the divide. Two additional scenario models were done to examine the effects of pumping near rivers. Transient models were used to simulate a rapid stage rise in a river during pumping at a well in carbonate and glacial aquifers near the river. Results of water-budget analyses indicate that induced infiltration, captured streamflow, and underflow were important for both glacial and carbonate aquifers; however, in many cases, traveltimes from the river to the well will limit river water from physically entering the well.

Sheets, Rodney A.; Dumouchelle, Denise H.; Feinstein, Daniel T.

2005-01-01

14

Research on voltage-divider of PMT applied to GRD  

International Nuclear Information System (INIS)

A transistor voltage divider is designed to decrease the dead time owing to large signal, and to satisfy the requirement of GRB detection. The simulation and experiment prove that the recovery time of the PMT working in the control of the transistor voltage divider is an order of magnitude smaller than the conventional resistor-capacitor voltage divider. (authors)

15

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

Science.gov (United States)

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

Miles, B.; Band, L. E.

2013-12-01

16

Studying the noise parameters of thin-film silicon resistors  

International Nuclear Information System (INIS)

The results of studies on spectral density and energy noise equivalent of thin-film resistors on the base of amorphous silicon and KIM and KVM commercial high-ohmic resistors are presented. Dependence of the active part of impedance on frequency is shown to be the main source of redundant noise in resistors. Dependence of spectral density of noise voltage of current noises of silicon resistors on applied voltage is described by the formula ST=B V2/f1.6 with the values B=(1.4-1.7)x10-12Hz0.6. As to noise parameters the silicon resistor is superior to commercial resistors

17

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

International Nuclear Information System (INIS)

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

18

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

Energy Technology Data Exchange (ETDEWEB)

This paper addresses thermal drift in sodium thiosulfate liquid resistors and their replacement with linear disk resistors from HVR Advanced Power Components. Sodium thiosulfate resistors in the FXR induction linear accelerator application have a temperature coefficient of {approx}1.8%/C. The FXR Marx banks send an 8kJ pulse through eight 524 cm{sup 3} liquid resistors at a repetition rate of up to 1 every 45 seconds. Every pulse increases the temperature of the solution by {approx}0.4 C which produces a 0.7% change in resistance. The typical cooling rate is {approx}0.4 C per minute which results in {approx}0.1% energy drop per pulse during continuous pulsed operations. A radiographic accelerator is extraordinarily sensitive to energy variations. Changes in beam energy produce movement in beam transport, changes in spot size, and large dose variations. If self-heating were the only problem, we could predict the increase in input voltage required to compensate for the energy loss. However, there are other variables that influence the temperature of the resistors such as focus magnet heating, changes in room temperature, changes in cooling water, where the cell is located, etc. Additionally not all of the resistors have equivalent cooling rates and as many as 32 resistors are driven from a single power source. The FXR accelerator group elected to replace the sodium thiosulfate resistors with HVR Linear Disk Resistors in a stack type configuration. With data limited for these resistors when used in oil and at low resistance values, a full characterization needed to be performed. High currents (up to 15kA), high voltages (up to 400kV), and Fast Rise times (<10ns) made a resistor choice difficult. Other solid resistors have been tried and had problems at the connection points and with the fact that the resistivity changed as they absorbed oil. The selected HVR resistors have the advantage of being manufactured with the oil impregnated in to them so this characteristic is minimized while still offering the desired low temperature coefficient of resistance compared to sodium thiosulfate. The characterization experiments and comparison with the sodium thiosulfate liquid resistors will be fully discussed and the final design described.

Kreitzer, B R; Houck, T L; Luchterhand, O C

2011-07-19

19

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

International Nuclear Information System (INIS)

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

20

Braking Resistor Scheme for Transient Stability Improvement  

Directory of Open Access Journals (Sweden)

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

Saeed Abazari

2007-09-01

 
 
 
 
21

Zinc oxide varistors and/or resistors  

Science.gov (United States)

Varistors and/or resistors that includes doped zinc oxide gel microspheres. The doped zinc oxide gel microspheres preferably have from about 60 to about 95% by weight zinc oxide and from about 5 to about 40% by weight dopants based on the weight of the zinc oxide. The dopants are a plurality of dopants selected from silver salts, boron oxide, silicon oxide and hydrons oxides of aluminum, bismuth, cobalt, chromium, manganese, nickel, and antimony.

Arnold, Jr., Wesley D. (Oak Ridge, TN); Bond, Walter D. (Knoxville, TN); Lauf, Robert J. (Oak Ridge, TN)

1993-01-01

22

Dynamic analysis on the closing resistors of Gas Insulated Switchgear  

International Nuclear Information System (INIS)

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

23

Room-temperature antiferromagnetic memory resistor  

Science.gov (United States)

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

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

2014-04-01

24

Room-temperature antiferromagnetic memory resistor.  

Science.gov (United States)

The bistability of ordered spin states in ferromagnets provides the basis for magnetic memory functionality. The latest generation of magnetic random access memories rely on an efficient approach in which magnetic fields are replaced by electrical means for writing and reading the information in ferromagnets. This concept may eventually reduce the sensitivity of ferromagnets to magnetic field perturbations to being a weakness for data retention and the ferromagnetic stray fields to an obstacle for high-density memory integration. Here we report a room-temperature bistable antiferromagnetic (AFM) memory that produces negligible stray fields and is insensitive to strong magnetic fields. We use a resistor made of a FeRh AFM, which orders ferromagnetically roughly 100 K above room temperature, and therefore allows us to set different collective directions for the Fe moments by applied magnetic field. On cooling to room temperature, AFM order sets in with the direction of the AFM moments predetermined by the field and moment direction in the high-temperature ferromagnetic state. For electrical reading, we use an AFM analogue of the anisotropic magnetoresistance. Our microscopic theory modelling confirms that this archetypical spintronic effect, discovered more than 150 years ago in ferromagnets, is also present in AFMs. Our work demonstrates the feasibility of fabricating room-temperature spintronic memories with AFMs, which in turn expands the base of available magnetic materials for devices with properties that cannot be achieved with ferromagnets. PMID:24464243

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

2014-04-01

25

Direct-Write Precision Resistors for Ceramic Packages  

Energy Technology Data Exchange (ETDEWEB)

A direct-write approach to f abricate high precision resistors is reported. Special attention is paid to the effect of print thickrw;s on the resistance value of buried resistors after a low temperature co-firing process. The results show that the direct-write approach provides a superior line definition and thickness control over a traditional screen printing process. Microstructural analysis indicates that there is an interdiffused layer developed between the resistor material and the low temperature co-fired ceramic substrate. These observations are consistent with electrical IIH.SUKHIlentS which show that resistance increases as the effective cross-sectional area is reduced. Th: resistance data show that the standard deviations for resistors printed on a 6" x 6" area are 59Z0 and 15$Z0 for the direct-write and the screen-printed patterns, respectively.

Dai, S.; Dimos, D.; Huang, R.F.; Rodriguez, M.A.; Wilcox, D.; Yang, P.

1998-11-30

26

Circular Planar Resistor Networks with Nonlinear and Signed Conductors  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We consider the inverse boundary value problem in the case of discrete electrical networks containing nonlinear (non-ohmic) resistors. Generalizing work of Curtis, Ingerman, Morrow, Colin de Verdiere, Gitler, and Vertigan, we characterize the circular planar graphs for which the inverse boundary value problem has a solution in this generalized non-linear setting. The answer is the same as in the linear setting. Our method of proof never requires that the resistors behave in ...

Johnson, Will

2012-01-01

27

Cooling process of the LHC energy extraction resistors  

CERN Document Server

The energy stored in all the LHC dipoles, about 11 GJ, can potentially cause severe damage to the magnets, bus bars and current leads. In order to protect the superconducting elements after a resistive transition, the energy is dissipated into dump resistors switched in series with the magnet chains. This paper describes the cooling process of the resistors and explains the choice process for the main components of the cooling equipment.

Peón-Hernández, G; Coelingh, G J; CERN. Geneva. ST Division

2003-01-01

28

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.)

29

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

Energy Technology Data Exchange (ETDEWEB)

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.

Wang Yi; He Lenian; Ning Zhihua; Shao Yali, E-mail: wangyi@vlsi.zju.edu.c [Institute of VLSI Design, Zhejiang University, Hangzhou 310027 (China)

2009-09-15

30

A random resistor network model of voltage trimming  

International Nuclear Information System (INIS)

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

31

Diurnal changes in concentration of rumen ciliates and in occurrence of dividing forms in water buffalo (Bubalus bubalus) fed once daily.  

Science.gov (United States)

When buffalo were fed once daily, significant diurnal variations in concentration of rumen ciliates and occurrence of dividing protozoa were found. Differences in proportions of dividing Entodinium- and Diplodinium-type ciliates were also observed. Results obtained suggest that the range of diurnal fluctuations in rumen protozoa concentration may be related to the percentage of dividing cells in populaitons of these organisms. PMID:405923

Michalowski, T

1977-01-01

32

Semiconducting oxide gas-sensitive resistors  

International Nuclear Information System (INIS)

ub>2)1x [with M: Mn, Fe, Co, Ni, Cu, Zn]. Effects of stoichiometry, microstructure, combustion gradient and surface segregation on gas (water, carbon monoxide, methane, propane and ammonia) sensitivity and selectivity have been observed and discussed. (author)

33

Aqueous-electrolyte resistors for pulsed power applications  

Science.gov (United States)

Aqueous-electrolyte resistors were developed for use as dummy loads in pulsed power systems. These resistors are simple, robust, low-inductance devices capable of operation at high voltage and high current, and may be used to dissipate large pulse energies without catastrophic failure. The resistivity and temperature coefficient of resistivity were measured for several candidate electrolytes, including aqueous solutions of copper sulfate, potassium and aluminum sulfate, potassium dichromate, silver nitrate, sodium dichromate, and sodium thiosulfate. The resistivity of potassium dichromate solution is expressed by the power law ?(? cm)=1640 C-1.0942 for electrolyte concentrations in the range C=0.025-25 g/l. The temperature coefficient of resistivity is in the range (1/?)(??/?Ts)=-(0.01-0.03)/°C for typical aqueous metal-salt electrolytes and is dependent on the solution temperature Ts and, to a lesser extent, on the electrolyte concentration. Aqueous solutions of potassium dichromate are compatible with brass, copper, and stainless-steel electrodes and polycarbonate and polymethylmethacrylate insulators, even at high concentration and elevated temperature. Such resistors give long shelf and operational lifetimes. If the maximum allowable resistance change (decrease) during the pulse is 10%, then the energy deposition per unit volume of electrolyte solution is limited to approximately 20 J/cm3 for resistors initially at room temperature.

Beverly, R. E., III; Campbell, R. N.

1995-12-01

34

Germanium as an integrated resistor material in RF MEMS switches  

Science.gov (United States)

This paper introduces the use of germanium as resistive material in RF MicroElectroMechanical (MEMS) devices. Integrated resistors are indeed highly required into RF MEMS switches, in order to prevent any RF signal leakage in the bias lines and also to be compatible with ICs. Germanium material presents strong advantages compared to others. It is widely used in microtechnologies, notably as an important semi-conductor in SiGe transistors as well as sacrificial or structural layers and also mask layer in various processes (Si micromachining especially). But it also presents a great electrical characteristic with a very high resistivity value. This property is particularly interesting for the elaboration of integrated resistors for RF components as it assures miniaturised resistors in total agreement with electromagnetic requirements. Its compatibility as resistive material in MEMS has been carried out. Its integration in the entire MEMS process has been fruitfully achieved and led to the successful demonstration and validation of integrated Ge resistors into serial RF MEMS variable capacitors, without any RF perturbations.

Grenier, K.; Bordas, C.; Pinaud, S.; Salvagnac, L.; Dubuc, D.

2007-05-01

35

Conjugate regenerative dividers.  

Science.gov (United States)

We discuss a novel design of a self-starting regenerative divider that permits division by 3, 4, 5, 6 ... instead of the usual 2. This is accomplished by having the loop oscillate simultaneously at two harmonically related conjugate frequencies, e.g., at nu/4 and 3nu/4. A prototype of the divide-by-four circuit has been constructed for an input frequency of 400 MHz. This divider exhibits very low phase noise, Fourier frequency (1 kHz) = -162 dBc/Hz and Fourier frequency (100 kHz) = -170 dBc/Hz, which is approximately 9 dB lower than that of its constituent parts. Simple modifications of the feedback loop of this circuit enabled it to divide by 3, 5, and 8. Operation at higher division ratios appears feasible under certain conditions. PMID:15128213

Sen Gupta, Amitava; Garcia Nava, J Francisco; Walls, Fred L

2004-03-01

36

The Open Access Divide  

Directory of Open Access Journals (Sweden)

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

Jingfeng Xia

2013-10-01

37

Electric force microscopy investigation of thick film resistors  

International Nuclear Information System (INIS)

Electric Force Microscopy was used to map the electric field distribution on the surface of thick resistors (TFR's) based on Bi-ruthenate, Pb-ruthenate and RuO2; the evolution of microstructure with the firing conditions has been investigated in some samples. The concentration of electric field around the conductive grains is a general feature of all the films, independently of the resistor composition. Then a meander-like path of charge carriers on a microscopic scale has been assessed. The segregated structure is enhanced at high firing temperatures. A strict correlation between the distribution of the electric field and the size of constituents in the paste was not clearly obtained. The results are discussed in connection with the electrical and piezoresistive properties of TFR's. (author)

38

PhET Simulation: Battery-Resistor Circuit  

Science.gov (United States)

This web page contains a simulation that allows users to explore a model of charge flow and resistance in a simple circuit. The resistance in the circuit and voltage of the battery can be adjusted. The resultant changes in the current, charge density, and heating of the resistor are shown. Simple schematics of the charge flow, collisions in the resistor, and electron density changes are used. Also included are instructional materials developed by the PhET project team specifically for use with this applet. This item is part of a larger collection of materials developed and maintained by the Physics Education Technology project (PhET) based on principles of physics education research.

2008-11-20

39

Video Analog Signal Divider  

Science.gov (United States)

Video analog signal divider produces black-and-white composite video signal based on color ratio. Device inexpensive, uses signal from standard red/green/blue camera as input. Used to produce quantitative thermal images of two-color phosphor coatings.

Buck, Gregory M.

1988-01-01

40

Random Resistor Network Model of Minimal Conductivity in Graphene  

Science.gov (United States)

Transport in undoped graphene is related to percolating current patterns in the networks of n- and p-type regions reflecting the strong bipolar charge density fluctuations. Finite transparency of the p-n junctions is vital in establishing the macroscopic conductivity. We propose a random resistor network model to analyze scaling dependencies of the conductance on the doping and disorder, the quantum magnetoresistance and the corresponding dephasing rate.

Cheianov, Vadim V.; Fal'Ko, Vladimir I.; Altshuler, Boris L.; Aleiner, Igor L.

2007-10-01

 
 
 
 
41

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

Science.gov (United States)

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

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

2013-10-22

42

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

CERN Document Server

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

Mrozik, Anna; Bilski, Pawel; Gieszczyk, Wojciech

2014-01-01

43

Shifts that divide populations  

Science.gov (United States)

If fitness landscape is non-concave, And the shift is wide, Then there is a good chance That population would divide. How does a population of organisms in an ecosystem respond to shifts in the environment? Answers to this question are critical to our understanding of the ecosystem and thus ability to manage it toward more desirable outcomes. We have developed a model of adaptation, based on replicator dynamics, in which we derive a simple but insightful threshold condition that separates two important types of responses: 'cohesive transition' in which the whole population changes gradually together, and 'population-dividing transition' in which the population splits into two groups with one eventually dominating the other. The threshold depends on the magnitude of the shift and the shape of the fitness landscape. Division in populations can fundamentally alter the functioning of the system; knowing the condition that gives rise to such division is thus fundamentally important.

Muneepeerakul, R.; Qubbaj, M. R.; Aggarwal, R.; Anderies, J. M.; Janssen, M. A.

2013-12-01

44

Divided-pulse lasers.  

Science.gov (United States)

We demonstrate the use of coherent division and recombination of the pulse within an ultrafast laser cavity to manage the nonlinear phase accumulation and scale the output pulse energy. We implement the divided-pulse technique in an ytterbium-doped fiber laser and achieve 16 times scaling of the pulse energy, to generate 6 nJ and 1.4 ps solitons in single-mode fiber. Potential extensions of this concept are discussed. PMID:24784100

Lamb, Erin S; Wright, Logan G; Wise, Frank W

2014-05-01

45

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

46

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

Science.gov (United States)

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

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

2014-10-01

47

Characterization measurements of the wideband infrared scene projector resistor array  

Science.gov (United States)

Kinetic energy weapon (KEW) programs under the Ballistic Missile Defense Office (BMDO) need high fidelity, fast framing infrared (IR) imaging seekers. As imaging sensors have matured to support BMDO, the complexity of functions assigned to the KEW weapon systems has amplified the necessity for robust hardware-in-the-loop (HWIL) simulation facilities to reduce program risk. Tactical weapon systems are also turning to imaging focal plane array (FPA) seekers. They too require more sophisticated HWIL testing. The IR projector, an integral component of a HWIL simulation, must reproduce the real world with enough fidelity that the unit-under-tests's (UUT) software will respond to the projected scenario of images as though it were viewing the real world. The MOSFET resistor array IR scene projector shows great promise in cryogenic vacuum chamber as well as room temperature testing. Under the wideband infrared scene projector (WISP) program, an enhanced version of the resistor array is currently under development. When the WISP system is delivered, the projector will consist of a 512 by 512 baseline array with the center 128 by 128 resistors having a higher output capability. For the development stage of the program, 512 by 512 prototype baseline and 128 by 128 prototype high dynamic range (HDR) arrays have been fabricated separately. Characterization measurements to include: spectral output, dynamic range capability, apparent temperature, rise time, fall time, cross talk, and current consumption have been accomplished on the prototype baseline and HDR arrays at the Kinetic Kill Vehicle Hardware-in-the-Loop Simulator (KHILS) Facility and the Guided Weapons Evaluation Facility (GWEF). Results from the measurements show the HDR array dynamic range is an order of magnitude greater than its predecessor. Other parameters such as droop, rise time, etc., either meet or are close to meeting system specifications. The final design of the arrays is currently in progress based on these results.

Jones, Lawrence E.; Olson, Eric M.; Goldsmith, George C., II

1996-06-01

48

Shifts that divide population  

Science.gov (United States)

How does a population of organisms in an ecosystem or of people in a society respond to rapid shifts in the environment? Answers to this question are critical to our ability to anticipate and cope with a changing ecohydrological system. We have developed a generic model of adaptation mechanisms, based on replicator dynamics, in which we derive a simple and insightful threshold condition that separates two important types of responses: 'cohesive transition' in which the whole population changes gradually together, and 'population-dividing transition' in which the population splits into two groups with one eventually dominating the other. The threshold depends on the magnitude of the shift and the shape of the fitness landscape. Division in populations can fundamentally alter the functioning of and induce subsequent feedbacks within the system; knowing the condition that gives rise to such division is thus fundamentally important.

Muneepeerakul, Rachata; Qubbaj, Murad; Aggarwal, Rimjhim; Anderies, John M.; Janssen, Marco

2014-05-01

49

Measurements of fuse and resistor characteristics for multimegajoule capacitor bank application  

International Nuclear Information System (INIS)

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

50

A broadband regenerative frequency divider in InGaP/GaAs HBT technology  

Science.gov (United States)

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

Jincan, Zhang; Yuming, Zhang; Hongliang, Lü; Yimen, Zhang; Min, Liu; Yinghui, Zhong; Zheng, Shi

2014-07-01

51

Cryogenic thermometers based on TVO type resistors and their application  

International Nuclear Information System (INIS)

Results of a study of the characteristics of cryogenic thermometers based on TVO-0.125 resistors (RH=1 k?) are presented. At a temperature of 4.2 K the repetition of values during 7 years is no worse than 0.015 K (? 0.4%), the sensitivity of some samples is from 570 ?/K to 1600 ?/K, the error in a magnetic field of 6 T is > 1%, the error after the ?-radiation by 1017 n/cm2 fast neutrons is -4 J/g.K, and the thermal inertia is ? 1 ms. Some interpolation formulae are presented. Recomendations on the application of the cryogenic thermometers in setups are given

52

Re-Si alloys for thin filmy precision resistors  

International Nuclear Information System (INIS)

Studied are the electrical properties of the resistive films based on the Re-Si binary alloys, containing (8-30) mas.% Si and on the Re-Si-W three-component alloy, containing 20 mas.% Si and 5 mas. % W. Studied was the influence of the sublayer temperature during spraying and of the heat-treatment regimes on the value of temperature resistance coefficient (TRC) as well as on the time stability of the films, produced on the basis of the Re-Si-W three-component alloy. Revealed were the optimum regimes of the film heat-treatment in order to obtain the minimum TRC values and to ensure the high time stability of the thin-film resistor electrical parameters

53

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

54

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

CERN Document Server

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

Poklonski, N A; 10.1134/1.1261987

2010-01-01

55

Novel Low Voltage CMOS Current Controlled Floating Resistor Using Differential Pair  

Directory of Open Access Journals (Sweden)

Full Text Available In this paper, a low voltage CMOS current controlled floating resistor which is convenient for integrated circuit implementation is designed by using differential pair. The proposed resistor has a simple circuit structure and low power dissipation. This circuit is required ± 0.75 V as a power supply. The basic advantages of this circuit are wide tuning range of the resistance value, satisfied frequency performance and worthwhile dynamic range. As well as the proposed circuit has floating structure, it is able to be used both positive and negative resistor. The performances of the proposed circuit are simulated with SPICE to justify the presented theory.

S. A. Tekin

2013-06-01

56

Ion backscattering study of tantalum nitride thin film resistors  

International Nuclear Information System (INIS)

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

57

Breakdown of two-phase random resistor networks  

International Nuclear Information System (INIS)

We describe the failure of two-component square- and cubic-lattice random resistor networks. The model behavior is dependent on the ratio of the conductances of the two components g, the ratio of the (brittle) failure thresholds of the two components i, the volume fraction p, and the sample size L. For much of the parameter space, the average strength of the networks shows a rather weak size effect, and a scaling argument suggests that this size effect is logarithmic. As usual, near the percolation points, there can be algebraic scaling provided i and g are very large or small. Near the limits p=0 and p=1, there is a logarithmic (''dilute-limit'') singularity in average strength. The ability to absorb damage is very strongly dependent on the model parameters. When one phase is more conducting and weaker than the other, and the strong phase is connected, the damage is usually extensive. Basically most of the weak bonds fail prior to the failure of the whole network. In the other regions of parameter space, damage is not extensive, but it does sometimes scale in a nontrivial way with the sample size

58

Advanced ceramic composite for high energy resistors. Characterization of electrical and physical properties  

International Nuclear Information System (INIS)

There is a need to characterize and apply advanced materials to improve the performance of components used in pulse power systems. One area of innovation is the use of bulk electrically conductive ceramics for non-inductive, high energy and high power electrical resistors. Standard Ceramics Inc. has developed a unique silicon carbide structural ceramic composite which exhibits electrical conductivity. The new conductive bulk ceramic material has a controlled microstructure, which results in improved homogeneity, making the material suitable for use as a non-inductive high energy resistor. This paper describes characterization of the material's physical and electrical properties and relates them to improvements in low-inductance, high temperature, high power density and high energy density resistors. The bulk resistor approach offers high reliability through better mechanical properties and simplicity of construction

59

High-ohmic low-noise resistor for spectrometers with cooled semiconductor detectors  

International Nuclear Information System (INIS)

BackgroUnd noise and energy resolution of a new type of resistors, designed to be used as a resistance in a feedback circuit of an X-ray spectrometer preamplifier are studied. The resistors are manufactured using the method of photolithography from high-resistance films, formed on the surface of lead-silicate glasses, as a result of redox processes during heat treatment in hydrogen atmosphere. Energy resolution of the spectrometer is measured on the line 55FeKX(Mn) with the energy 5.8 keV. The conclusion is made, that the level of background noises in the resistors studied is approximately 4 times lower the level of noises in the KVM type resistors, which are commercially produced in industry

60

On the effect of a parallel resistor in the Chua's circuit  

Energy Technology Data Exchange (ETDEWEB)

We report a numerical bifurcation study on the Chua's circuit with parallel resistor. Through the largest Lyapunov exponent, we constructed a two-dimensional parameter space of the model. We also implemented the experimental circuit to show the similarities between the model and the experimental data. With that modification we discuss the effect of a parallel resistor in the dynamics of a Chua's circuit.

Prebianca, Flavio; Albuquerque, Holokx A [Departamento de Fisica, Universidade do Estado de Santa Catarina, 89223-100 Joinville (Brazil); Rubinger, Rero M, E-mail: dfi2haa@joinville.udesc.br [Departamento de Fisica e Quimica, Universidade Federal de Itajuba, 37500-903 Itajuba (Brazil)

2011-03-01

 
 
 
 
61

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

CERN Document Server

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

62

Diluted Networks of Nonlinear Resistors and Fractal Dimensions of Percolation Clusters  

CERN Document Server

We study random networks of nonlinear resistors, which obey a generalized Ohm's law, $V\\sim I^r$. Our renormalized field theory, which thrives on an interpretation of the involved Feynman Diagrams as being resistor networks themselves, is presented in detail. By considering distinct values of the nonlinearity r, we calculate several fractal dimensions characterizing percolation clusters. For the dimension associated with the red bonds we show that $d_{\\mbox{{\\scriptsize red}}} = 1/\

Janssen, H K

1999-01-01

63

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

64

The Divided Self in Adolescence.  

Science.gov (United States)

Interviews with adolescents revealed that they have a complex "divided metaphysics" of subjectivity, based on a dualistic view of reality versus appearance. Certain conceptual methodological issues surrounding research into self identity are discussed. (Author/DB)

Broughton, J. M.

1981-01-01

65

Aristotle on Dividing the Soul  

Directory of Open Access Journals (Sweden)

Full Text Available Aristotle’s account of the soul requires an adequate division of the soul. However, Aristotle refuses to divide the soul spatially, and insists that it is divided only conceptually, that is ‘in being’ or ‘in account’. In this paper I explain what this division amounts to and how Aristotle executes it. Then I discuss three important advantages of such a division of the soul. First, it enables Aristotle to avoid problems that he identified in Plato’s account of the soul. Second, it allows him to treat a particular capacity of the soul as itself divided into distinct parts or aspects. Third, it allows him to treat a particular capacity of the soul as a distinct part or aspect of some more comprehensive capacity.

Pavel Gregoric

2008-11-01

66

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

Directory of Open Access Journals (Sweden)

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

Taufiqqurrachman

2014-03-01

67

Aristotle on Dividing the Soul  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Aristotle’s account of the soul requires an adequate division of the soul. However, Aristotle refuses to divide the soul spatially, and insists that it is divided only conceptually, that is ‘in being’ or ‘in account’. In this paper I explain what this division amounts to and how Aristotle executes it. Then I discuss three important advantages of such a division of the soul. First, it enables Aristotle to avoid problems that he identified in Plato’s account of the soul. Second, it ...

Pavel Gregoric

2008-01-01

68

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

International Nuclear Information System (INIS)

The electrochemical and microstructural properties of carbon film electrodes made from carbon film electrical resistors of 1.5, 15, 140 ? and 2.0 k? nominal resistance have been investigated before and after electrochemical pre-treatment at +0.9 V vs SCE, in order to assess the potential use of these carbon film electrodes as electrochemical sensors and as substrates for sensors and biosensors. The results obtained are compared with those at electrodes made from previously investigated 2 ? carbon film resistors. Cyclic voltammetry was performed in acetate buffer and phosphate buffer saline electrolytes and the kinetic parameters of the model redox system Fe(CN)63-/4- obtained. The 1.5 ? resistor electrodes show the best properties for sensor development with wide potential windows, similar electrochemical behaviour to those of 2 ? and close-to-reversible kinetic parameters after electrochemical pre-treatment. The 15 and 140 ? resistor electrodes show wide potential windows although with slower kinetics, whereas the 2.0 k? resistor electrodes show poor cyclic voltammetric profiles even after pre-treatment. Electrochemical impedance spectroscopy related these findings to the interfacial properties of the electrodes. Microstructural and morphological studies were carried out using contact mode Atomic Force Microscopy (AFM), Confocal Raman spectroscopy and X-ray diffraction. AFM showed more homogeneity of the films with lower nominal resistanc films with lower nominal resistances, related to better electrochemical characteristics. X-ray diffraction and Confocal Raman spectroscopy indicate the existence of a graphitic structure in the carbon films

69

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

Science.gov (United States)

The electrochemical and microstructural properties of carbon film electrodes made from carbon film electrical resistors of 1.5, 15, 140 ? and 2.0 k? nominal resistance have been investigated before and after electrochemical pre-treatment at +0.9 V vs SCE, in order to assess the potential use of these carbon film electrodes as electrochemical sensors and as substrates for sensors and biosensors. The results obtained are compared with those at electrodes made from previously investigated 2 ? carbon film resistors. Cyclic voltammetry was performed in acetate buffer and phosphate buffer saline electrolytes and the kinetic parameters of the model redox system Fe(CN) 63-/4- obtained. The 1.5 ? resistor electrodes show the best properties for sensor development with wide potential windows, similar electrochemical behaviour to those of 2 ? and close-to-reversible kinetic parameters after electrochemical pre-treatment. The 15 and 140 ? resistor electrodes show wide potential windows although with slower kinetics, whereas the 2.0 k? resistor electrodes show poor cyclic voltammetric profiles even after pre-treatment. Electrochemical impedance spectroscopy related these findings to the interfacial properties of the electrodes. Microstructural and morphological studies were carried out using contact mode Atomic Force Microscopy (AFM), Confocal Raman spectroscopy and X-ray diffraction. AFM showed more homogeneity of the films with lower nominal resistances, related to better electrochemical characteristics. X-ray diffraction and Confocal Raman spectroscopy indicate the existence of a graphitic structure in the carbon films.

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

2008-08-01

70

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

International Nuclear Information System (INIS)

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

71

Getting Past the "Digital Divide"  

Science.gov (United States)

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

McCollum, Sean

2011-01-01

72

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

International Nuclear Information System (INIS)

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. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

73

The first measurements on SiPMs with bulk integrated quench resistors  

International Nuclear Information System (INIS)

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

74

Study of steatites for using as a high density resistor nucleus; Estudo de esteatito para utilizacao como nucleo de resistor de alta densidade  

Energy Technology Data Exchange (ETDEWEB)

In nuclear facilities where high density power resistors are applied in fuel irradiation circuits in the PWR reactor type, the probability of accident is high, therefore, it is necessary to experimentally test the nuclear facility safety project. In order to reach this goal, it is necessary to use an electric isolated material capable of withstanding high temperatures without melting or becoming deteriorated. That is where the lytologic type, classified as steatite or soapstone, must be used. The present work characterizes the steatite samples, suggesting the lytologic type to be used as the high density power resistors nucleus. Samples were selected from a steatite' processing industry located in the district of Cachoeira do Campo in Minas Gerais State. These lytologic types were sawed, evaluated macroscopically, subjected to specific preparation methods for chemical analysis and X rays diffraction, exposed to high temperatures, as well as petrographic studies and microanalyses. Samples marked by lower concentration levels of carbonates. (author)

Salas, Humberto Terrazas; Costa, Antonio Carlos Lopes da; Barbosa, Joao Batista Santos; Silva, Luiz Carlos da; Rocha, Francisco de Assis [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, MG (Brazil)]. E-mail: salasht@cdtn.br

2005-07-01

75

Information Societies and Digital Divides  

CERN Document Server

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

Sorj, Bernardo

2008-01-01

76

Demonstration of a silicon photomultiplier with bulk integrated quenching resistors on epitaxial silicon  

International Nuclear Information System (INIS)

In this paper we present the experimental results of a silicon photomultiplier (SiPM) with bulk integrated quenching resistors on epitaxial silicon. Compared with existing SiPM with polysilicon quenching resistors on the surface or with MRS structure, it has potential advantages of high photon detection efficiency (PDE) while retaining a large micro-cell density and the fabrication process is also simplified. The SiPM with the micro-cell density up to 104/mm2 and the PDE up to 25.6% is demonstrated. The characteristics of dark count rate, single photon detection capability, gain, optical crosstalk and PDE have been investigated and discussed.

77

Advanced ceramic composite for high energy resistors : Characterization of electrical and physical properties  

International Nuclear Information System (INIS)

There is a need to characterize and apply advanced materials to improve the performance of components used in pulse power systems. One area for innovation is the use of bulk electrically conductive ceramics for non-inductive, high energy and high power electrical resistors. Standard Ceramics Inc. has developed a unique silicon carbide structural ceramic composite which exhibits electrical conductivity. The new, new, conductive, bulk ceramic material has a controlled microstructure, which results in improved homogeneity, making the material suitable for use as a non-inductive, high energy resistor

78

Gauge factor enhancement driven by heterogeneity in thick-film resistors  

International Nuclear Information System (INIS)

We present a simple picture of the gauge factor (GF) enhancement in highly heterogeneous materials such as thick-film resistors. We show that when the conducting phase is stiffer than the insulating one, the local strains within the latter are enhanced with respect to the averaged macroscopic strain. Within a simple model of electron tunneling processes, we show that the enhanced local strain leads to values of GF higher than those expected for a homogeneous system. Moreover, we provide formulas relating the enhancement of GF to the elastic and microstructural characteristics of thick-film resistors. [copyright] 2001 American Institute of Physics

79

Determination of Reduced Number and Suitable Locations of Fuzzy Logic Controlled Braking Resistors for Transient Stability Enhancement  

Science.gov (United States)

Braking resistor is known to be a very powerful tool for transient stability improvement in electric power systems. Usually, in a large power system braking resistors are placed at each generator terminal bus which requires a high installation as well as operation cost. Also, heavy computation is required for the controllers used for the switching of the resistors. From these viewpoints, this paper directs to the study of installation of reduced number of fuzzy logic controlled braking resistors at suitable locations for transient stability enhancement. Groups of coherent generators in the power system are determined. Then one braking resistor is installed in each of the coherent group and at each of the remaining generator terminal bus. Thus, the number of braking resistors is reduced and hence the installation and operation cost as well as computational burden for the controllers are minimized. The suitable location for the braking resistor in each coherent group of generators is determined according to the values of the transient stability index as calculated for a 3LG (Three-phase-to-ground) fault at the points near the generators of the coherent group without considering the braking resistors in the system. The effectiveness of the proposed method is demonstrated through EMTP simulations for the IEEJ West-10 machine model system.

Ali, Mohd. Hasan; Murata, Toshiaki; Tamura, Junji

80

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2012-12-15

 
 
 
 
81

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

International Nuclear Information System (INIS)

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

82

Advanced ceramic composite for high energy resistors. Characterization of electrical and physical properties  

International Nuclear Information System (INIS)

Full text : There is a need to characterize and apply advanced materials to improve the performance of components used in pulse power systems. One area for innovation is the use of bulk electrically conductive ceramics for non-inductive, high energy and high power electrical resistors. Standard Ceramics, Inc. has developed a unique silicon carbide structural ceramic composite which exhibits electrical conductivity. The new conductive bulk ceramic material has a controlled microstructure, which results an improved homogeneity, making the material suitable for use as a non-inductive, high energy resistor. The new material has higher density, highee peak of temperature limit and greater physical strength compared with bulk ceramics currently used for pulsed power resistors. This paper describes characterization of the material's physical and electrical properties and relates them to improvements in low-power density, as compared to existing components would be expected and derived from specific properties such as good thermal conductivity, high strength, thermal shock resistance and high temperature capability. The bulk resistor approach that weas proposed offers high reliability through better mechanical properties and simplicity of construction

83

Selectively doped heterostructure frequency dividers  

Science.gov (United States)

The operation of high-speed divide-by-two circuit (binary counter) composed of selectively doped heterostructure logic gates is reported for the first time. These field-effect transistor circuits utilize the enhanced transport properties of high-mobility electrons confined near a heterojunction interface in a selectively doped AlGaAs/GaAs structure. The dividers are based on a Type-D flip-flop composed of six direct-coupled NOR-gates having 1-micron gate lengths and 4-micron source-drain spacings. They are fabricated by conventional optical contact lithography on a four-layer Al(0.3)Ga(0.7)As/GaAs structure grown by molecular-beam epitaxy. Successful operation is demonstrated at 5.9 GHz at 77 K for 1.3-V bias and 30-mW total power dissipation (including output buffers) and 3.7 GHz at 300 K for 1.4-V bias and 19-mW total power dissipation. Total power dissipation values as low as 3.9 mW at 0.65-V bias were also obtained for 2.85-GHz operation at 300 K. These preliminary results illustrate the promise of SDHT logic for ultrahigh-speed low-power applications.

Kiehl, R. A.; Feuer, M. D.; Hendel, R. H.; Keramidas, V. G.; Allyn, C. L.; Dingle, R.; Hwang, J. C. M.

1983-10-01

84

Au/Ti resistors used for Nb/Pb-alloy Josephson junctions. I. Electrical stability  

International Nuclear Information System (INIS)

Bilayered Au/Ti films are very attractive for use as resistor materials of experimental Nb/Pb-alloy Josephson junction devices. In order to predict the electrical stability of the Au/Ti resistors during storage at room temperature, changes in microstructure and electrical resistivity of Ti and Au/Ti films during isothermal annealing at temperatures ranging from 298--473 K were studied using transmission electron microscopy, x-ray diffraction, and electrical measurements. Growth of Ti grains during annealing was observed in these films. The activation energy for the grain growth was determined to be 1.51 eV. Decreases in the sheet resistance measured at 4.2 K were observed at the early stages of isothermal annealing. By analyzing the annealing temperature dependence of rates of resistance changes, the activation energy of 1.49 eV was obtained. This energy value is very close to that obtained for the grain growth and, therefore, one of the main causes in the resistance decrease is believed to be due to the growth of Ti grains. Based on the present results, a model to predict the electrical resistance change for the Au/Ti films during storage at room temperature was established. The model predicted that change in the resistance can be significantly reduced by preannealing the resistors at an elevated temperature. The prediction was supported by the experiment and an excellent quantitative agreement between measured resistance values and those predicted by the model was oues and those predicted by the model was obtained. Based on this model, the change was predicted to be -1.5% after about 3 years at room temperature, if the resistors were preannealed at 353 K for 10 h. This resistor stability is satisfactory for designing logic and memory circuits of Josephson devices, and it can be increased simply by preannealing for longer times at 353 K

85

Au/Ti resistors used for Nb/Pb-alloy Josephson junctions. I. Electrical stability  

Energy Technology Data Exchange (ETDEWEB)

Bilayered Au/Ti films are very attractive for use as resistor materials of experimental Nb/Pb-alloy Josephson junction devices. In order to predict the electrical stability of the Au/Ti resistors during storage at room temperature, changes in microstructure and electrical resistivity of Ti and Au/Ti films during isothermal annealing at temperatures ranging from 298--473 K were studied using transmission electron microscopy, x-ray diffraction, and electrical measurements. Growth of Ti grains during annealing was observed in these films. The activation energy for the grain growth was determined to be 1.51 eV. Decreases in the sheet resistance measured at 4.2 K were observed at the early stages of isothermal annealing. By analyzing the annealing temperature dependence of rates of resistance changes, the activation energy of 1.49 eV was obtained. This energy value is very close to that obtained for the grain growth and, therefore, one of the main causes in the resistance decrease is believed to be due to the growth of Ti grains. Based on the present results, a model to predict the electrical resistance change for the Au/Ti films during storage at room temperature was established. The model predicted that change in the resistance can be significantly reduced by preannealing the resistors at an elevated temperature. The prediction was supported by the experiment and an excellent quantitative agreement between measured resistance values and those predicted by the model was obtained. Based on this model, the change was predicted to be -1.5% after about 3 years at room temperature, if the resistors were preannealed at 353 K for 10 h. This resistor stability is satisfactory for designing logic and memory circuits of Josephson devices, and it can be increased simply by preannealing for longer times at 353 K.

Murakami, M.; Alessandrini, E.I.; Kim, K.K.

1984-10-01

86

Environment, information divide and design  

International Nuclear Information System (INIS)

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

87

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

2005-03-01

88

Preferential solvation: dividing surface vs excess numbers.  

Science.gov (United States)

How do osmolytes affect the conformation and configuration of supramolecular assembly, such as ion channel opening and actin polymerization? The key to the answer lies in the excess solvation numbers of water and osmolyte molecules; these numbers are determinable solely from experimental data, as guaranteed by the phase rule, as we show through the exact solution theory of Kirkwood and Buff (KB). The osmotic stress technique (OST), in contrast, purposes to yield alternative hydration numbers through the use of the dividing surface borrowed from the adsorption theory. However, we show (i) OST is equivalent, when it becomes exact, to the crowding effect in which the osmolyte exclusion dominates over hydration; (ii) crowding is not the universal driving force of the osmolyte effect (e.g., actin polymerization); (iii) the dividing surface for solvation is useful only for crowding, unlike in the adsorption theory which necessitates its use due to the phase rule. KB thus clarifies the true meaning and limitations of the older perspectives on preferential solvation (such as solvent binding models, crowding, and OST), and enables excess number determination without any further assumptions. PMID:24689966

Shimizu, Seishi; Matubayasi, Nobuyuki

2014-04-10

89

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

90

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

91

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)

92

Nanoporous carbon tunable resistor/transistor and methods of production thereof  

Energy Technology Data Exchange (ETDEWEB)

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

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

2014-04-22

93

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

94

Study of steatites for using as a high density resistor nucleus  

International Nuclear Information System (INIS)

In nuclear facilities where high density power resistors are applied in fuel irradiation circuits in the PWR reactor type, the probability of accident is high, therefore, it is necessary to experimentally test the nuclear facility safety project. In order to reach this goal, it is necessary to use an electric isolated material capable of withstanding high temperatures without melting or becoming deteriorated. That is where the lytologic type, classified as steatite or soapstone, must be used. The present work characterizes the steatite samples, suggesting the lytologic type to be used as the high density power resistors nucleus. Samples were selected from a steatite' processing industry located in the district of Cachoeira do Campo in Minas Gerais State. These lytologic types were sawed, evaluated macroscopically, subjected to specific preparation methods for chemical analysis and X rays diffraction, exposed to high temperatures, as well as petrographic studies and microanalyses. Samples marked by lower concentration levels of carbonates. (author)

95

The Study of a Portable Precision Air Enclosure for Preserving Standard Resistor  

International Nuclear Information System (INIS)

A novel portable precision air enclosure was designed in this paper. Orthogonalization of the coefficients matrix to decouple the all parts of the control system was attained in theory and heating wires were wound on the surface of the aluminum chamber evenly in construction. Foam plastic was placed between outer and aluminum chamber as thermal insulation. The inner space is 300 mmx250 mmx300 mm, where can fit one SR 102 type resistor or two Tinsley 5685 type resistors. The total weight of the enclosure is about 25kg, which is still a portable one. Its outstanding feature is the temperature difference between top and bottom was offset. Experiment result shows that the monthly inner temperature homogeneity and stability of the enclosure are within 2 mK

96

Percolation-induced exponential scaling in the large current tails of random resistor networks  

Digital Repository Infrastructure Vision for European Research (DRIVER)

There is a renewed surge in percolation-induced transport properties of diverse nano-particle composites (cf. RSC Nanoscience & Nanotechnology Series, Paul O'Brien Editor-in-Chief). We note in particular a broad interest in nano-composites exhibiting sharp electrical property gains at and above percolation threshold, which motivated us to revisit the classical setting of percolation in random resistor networks but from a multiscale perspective. For each realization of random...

Shi, Feng; Wang, Simi; Mucha, Peter J.; Forest, M. Gregory

2012-01-01

97

Low-temperature thick-film dielectrics and resistors for metal substrates  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this work, a set of low-temperature thick-film dielectrics consisting of two high-lead low-temperature glasses, stabilised by various amounts of alumina filler, is characterised on alumina and aluminium metal, as a function of firing temperature. Corresponding resistors based on the same glasses as the dielectrics, but with RuO2 as a conductive phase, were studied on the dielectrics. The purpose of these materials is to enable deposition of thick- film electronics onto substrate...

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

2005-01-01

98

Analysis of Regulated PV Fed Switched Reluctance Motor Drives Using Repression Resistor Converter  

Directory of Open Access Journals (Sweden)

Full Text Available The performance of the four phases SRM is investigated especially driven by standalone PV fed module with Repression Resistor converter. Inorder to perform the good working condition of motor, the basic behavior of SRM should be researched. Because of abundant solar energy sources the application is introduced in high speed drives such as SRM in this paper. The results also compared with SRM driven by DC source offers superior performance in simulation analysis.

S.Sujitha

2014-07-01

99

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

International Nuclear Information System (INIS)

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

100

A comparative study of two phenomenological models of dephasing in series and parallel resistors  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We compare two phenomenological models of dephasing that are in use recently. We show that the stochastic absorption model leads to reasonable dephasing in series (double barrier) and parallel (ring) quantum resistors in presence and absence of magnetic flux. For large enough dephasing it leads to Ohm's law. On the other hand a random phase based statistical model that uses averaging over Gaussian random-phases, picked up by the propagators, leads to several inconsistencies....

Bandopadhyay, Swarnali; Chaudhuri, Debasish; Jayannavar, Arun M.

2007-01-01

 
 
 
 
101

Quantum Resistor-Capacitor Circuit with Majorana Fermion Modes in Chiral Topological Superconductor  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We investigate the mesoscopic resistor-capacitor circuit consisting of a quantum dot coupled to spatially separated Majorana fermion modes in a chiral topological superconductor. We find substantially enhanced relaxation resistance due to the nature of Majorana fermions, which are their own anti-particles and composed of particle and hole excitations in the same abundance. Further, if only a single Majorana mode is involved, the zero-frequency relaxation resistance is comple...

Lee, Minchul; Choi, Mahn-soo

2014-01-01

102

Pyramidal resistor networks for electrical impedance tomography with partial boundary measurements  

International Nuclear Information System (INIS)

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

103

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

Directory of Open Access Journals (Sweden)

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

V. Niranjan

2014-09-01

104

Influence of electrical stress on printed polymer resistors filled with carbon nanomaterials  

Science.gov (United States)

Superior electrical properties of carbon nanotubes were utilized by the authors in the fabrication of printed resistors. In common applications such as electrodes or sensors, only basic electrical and mechanical properties are investigated, leaving aside other key parameters related to the stability and reliability of particular elements. In this paper we present experimental results on the properties of printed resistive layers. One of the most important issues is their stability under high currents creating excessive thermal stresses. In order to investigate such behavior, a high direct current stress test was performed along with the observation of temperature distribution that allowed us to gain a fundamental insight into the electrical behavior at such operating conditions. These experiments allowed us to observe parametric failure or catastrophic damage that occurred under excessive supply parameters. Electrical parameters of all investigated samples remained stable after applying currents inducing an increase in temperature up to 130 °C and 200 °C. For selected samples, catastrophic failure was observed at the current values inducing temperature above 220 °C and 300 °C but in all cases the failure was related to the damage of PET or alumina substrate. Additional experiments were carried out with short high voltage pulse stresses. Printed resistors filled with nanomaterials sustained similar voltage levels (up to 750 V) without changing their parameters, while commonly used graphite filled polymer resistors changed their resistance value.

S?oma, Marcin; Jakubowska, Ma?gorzata; Sza?atkiewicz, Jakub

2013-10-01

105

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

2013-05-01

106

Phase noise performance of analog frequency dividers.  

Science.gov (United States)

The phase noise performance obtainable using silicon and GaAs-based TTL (transistor-transistor logic) and ECL (emitter-coupled logic) logic level digital frequency dividers is discussed. Measurement of the spectral performance of two types of analog dividers is reported: a parametric divider using varactor diodes and a regenerative-type divider incorporating a double-balanced mixer in the oscillator feedback circuit. Both dividers were configured for divide-by-two operation at VHF. Evaluation indicates the regenerative divider is capable of providing much lower phase noise than conventional digital logic level devices. The regenerative divider can be successfully operated over bandwidths in excess of an octave, and the design lends itself to small (i.e. TO-8) modular package implementation. Operating frequencies are bounded only by the range of the mixer and RF amplifier utilized and, as such, should extend from HF through microwave. PMID:18285044

Driscoll, M M

1990-01-01

107

Divided power structures and chain complexes  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We interpret divided power structures on the homotopy groups of simplicial commutative rings as having a counterpart in divided power structures on chain complexes coming from a non-standard symmetric monoidal structure.

Richter, Birgit

2008-01-01

108

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 effectiv...

Hong-Min Lee; Hyung-Sup Lee

2013-01-01

109

Low-Powered Transistor Divider for PMT  

CERN Document Server

A transistor high-voltage divider for photomultipliers is developed. The circuit contains a high-resistance linear resistive divider for setting potential distribution between dynodes and emitter followers to support this distribution. The divider is characterized by a low level of diffused power and stability of photomultiplier gain at change of average anode current in the whole range of measurements.

Kalinnikov, V A; Kuchinskiy, N A; Smirnov, V S; Tikhonov, A G

2005-01-01

110

Replacement divider plate performance under LOCA loading  

International Nuclear Information System (INIS)

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)

111

Study of System Stabilization of Disk Type MHD Power Generation by Damping Resistor  

Science.gov (United States)

Effects of installed SDR (System Dumping Resistors) on the stability of open-cycle disk MHD generator and synchronous generator system connected in parallel to power transmission lines are numerically studied. Usually the SDR is used to absorb the output energy of synchronous generator and to get stability of the power transmission system when faults occur in the A.C. power transmission lines. In this paper, we propose to apply the SDR in the D.C. lines between the MHD generator and the primary side of connected line-commutated inverters. We show that the SDR is effective for the system stability by a time dependent numerical analysis.

Hayanose, Nobuhiko; Inui, Yoshitaka; Ishikawa, Motoo

112

Dispersive dielectric and conductive effects in 2D resistor-capacitor networks  

International Nuclear Information System (INIS)

How to predict and better understand the effective properties of disordered material mixtures has been a long-standing problem in different research fields, especially in condensed matter physics. In order to address this subject and achieve a better understanding of the frequency-dependent properties of these systems, a large 2D L x L square structure of resistors and capacitors was used to calculate the immittance response of a network formed by random filling of binary conductor/insulator phases with 1000 ? resistors and 10 nF capacitors. The effects of percolating clusters on the immittance response were studied statistically through the generation of 10 000 different random network samples at the percolation threshold. The scattering of the imaginary part of the immittance near the dc limit shows a clear separation between the responses of percolating and non-percolating samples, with the gap between their distributions dependent on both network size and applied frequency. These results could be used to monitor connectivity in composite materials. The effects of the content and structure of the percolating path on the nature of the observed dispersion were investigated, with special attention paid to the geometrical fractal concept of the backbone and its influence on the behavior of relaxation-time distributions. For three different resistor-capacitor proportions, the appropriateness of many fitting models was investigated for modeling and analyzing individual resistor-capacitor network dispersed frequency responses using complex-nonlinear-least-squares fitting. Several remarkable new features were identified, including a useful duality relationship and the need for composite fitting models rather than either a simple power law or a single Davidson-Cole one. Good fits of data for fully percolating random networks required two dispersive fitting models in parallel or series, with a cutoff at short times of the distribution of relaxation times of one of them. In addition, such fits surprisingly led to cutoff parameters, including a primitive relaxation or crossover time, with estimated values comparable to those found for real dispersive materials.

113

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

CERN Document Server

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

114

Quantum Resistor-Capacitor Circuit with Majorana Fermion Modes in a Chiral Topological Superconductor  

Science.gov (United States)

We investigate the mesoscopic resistor-capacitor circuit consisting of a quantum dot coupled to spatially separated Majorana fermion modes in a chiral topological superconductor. We find substantially enhanced relaxation resistance due to the nature of Majorana fermions, which are their own antiparticles and are composed of particle and hole excitations in the same abundance. Further, if only a single Majorana mode is involved, the zero-frequency relaxation resistance is completely suppressed due to a destructive interference. As a result, the Majorana mode opens an exotic dissipative channel on a superconductor which is typically regarded as dissipationless due to its finite superconducting gap.

Lee, Minchul; Choi, Mahn-Soo

2014-08-01

115

Circuit elements at optical frequencies: nano-inductors, nano-capacitors and nano-resistors  

CERN Document Server

We present some ideas for synthesizing nanocircuit elements in the optical domain using plasmonic and non-plasmonic nanoparticles. Three basic circuit elements, i.e., nano-inductors, nano-capacitors, and nano-resistors, are discussed in terms of small nanostructures with different material properties. Coupled nanocircuits and parallel and series combinations are also envisioned, which may provide road maps for the synthesis of more complex nanocircuits in the IR and visible bands. Ideas for the optical implementation of right-handed and left-handed nano-transmission lines are also forecasted.

Engheta, N; Alu, A; Engheta, Nader; Salandrino, Alessandro; Alu, Andrea

2004-01-01

116

Quantum resistor-capacitor circuit with Majorana fermion modes in a chiral topological superconductor.  

Science.gov (United States)

We investigate the mesoscopic resistor-capacitor circuit consisting of a quantum dot coupled to spatially separated Majorana fermion modes in a chiral topological superconductor. We find substantially enhanced relaxation resistance due to the nature of Majorana fermions, which are their own antiparticles and are composed of particle and hole excitations in the same abundance. Further, if only a single Majorana mode is involved, the zero-frequency relaxation resistance is completely suppressed due to a destructive interference. As a result, the Majorana mode opens an exotic dissipative channel on a superconductor which is typically regarded as dissipationless due to its finite superconducting gap. PMID:25170724

Lee, Minchul; Choi, Mahn-Soo

2014-08-15

117

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

CERN Document Server

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

Saveliev, V

2000-01-01

118

On the Transformation of a Floating Resistor Oscillator to Grounded Passive Element Oscillators  

Directory of Open Access Journals (Sweden)

Full Text Available A generalization method is used to transform a floating resistor oscillator circuit to a family of sixteen grounded capacitor oscillators using the current conveyor (CCII or the inverting current conveyor (ICCII or combination of both. Two of the oscillator circuits have a floating property. A new family of sixteen oscillator circuits is generated from the known circuit using the adjoint circuit theorem. It is also shown that the oscillator under consideration leads to the generation of other known and new grounded passive element oscillators employing the differential voltage current conveyor (DVCC and the balanced output current conveyor (BOCCII.

Ahmed M Soliman

2010-09-01

119

Gauge factor enhancement driven by heterogeneity in thick-film resistors  

CERN Document Server

We present a simple picture of the gauge factor (GF) enhancement in highly heterogeneous materials such as thick-film resistors. We show that when the conducting phase is stiffer than the insulating one, the local strains within this latter are enhanced with respect to the averaged macroscopic strain. Within a simple model of electron tunneling processes, we show that the enhanced local strain leads to values of GF higher than those expected for a homogeneous system. Moreover we provide formulas relating the enhancement of GF to the elastic and microstructural characteristics of TFRs.

Grimaldi, C; Strässler, S

2000-01-01

120

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

DEFF Research Database (Denmark)

This paper investigates the effect of Series Dynamic Breaking Resistor (SDBR) sizing on a Doubly Fed Induction Generator (DFIG) based wind power conversion system. The boundary of the SDBR value is firstly derived by taking into account the controllability of the rotor side converter and the maximum allowable voltage of the stator. Then the impact of the SDBR value on the rotor current, stator voltage, DC-link voltage, reactive power capability and introduced power loss during voltage sag operation is evaluated by simulation. The presented study enables a trade-off sizing of the SDBR among the above performance factors.

Soliman, Hammam; Wang, Huai

2014-01-01

 
 
 
 
121

The Southern Ocean Cadmium Isotope Divide  

Science.gov (United States)

We report Cd isotope and concentration data in a transect of surface waters in the Southern Ocean sampled along the Zero Meridian (42°S-68°S, Geotraces ANT24-3 cruise, austral autumn). The objective is to examine the response of Cd isotopes to (1) differences in biological productivity in this High-Nutrient-Low-Chlorophyll region, (2) ocean circulation in the wind-driven upwelling system of the Antarctic Circum-Polar Current (ACC), and (3) how these might be related to the efficiency of the biological carbon pump. Our data show a strong northward gradient in both Cd isotopes and concentrations, interrupted by a change in the sense of variation at about 56°S. The remarkable coincidence between the Cd isotope divide at 56°S and the location of the Southern Boundary of the ACC, together with evidence for advection of the Cd isotope and elemental signal by northward Ekman transport in the surface layer, demonstrate that Cd isotopes trace surface ocean circulation regimes. Co-variations between Cd isotope ratios and concentrations exhibit two negative correlations which separate the waters from the ACC and the Weddell Gyre into distinct Cd isoscapes. The linear arrays are consistent with Rayleigh fractionation kinetics and imply a greater Cd isotope effect due to biological consumption in the ACC compared to that in the Weddell Gyre. Strengthening of the “biological Cd” signal along the ACC array reflects progressive Cd depletion, resulting from enhanced biological uptake as UCPW flows northward feeding the low latitude thermohaline circulation. The doubling of Cd isotope fractionation in the Weddell Gyre relative to the ACC can be accounted for by differences in phytoplankton biomass and species distribution along the Zero Meridian as well as differences in physiological mechanisms of Cd uptake by marine phytoplankton. These results open up new perspectives for paleoceanographic applications of Cd isotopes as a proxy of past changes in the biological carbon pump.

Abouchami, W.; Galer, S. J.; de Baar, H. J.; Alderkamp, A.; Middag, R.; Laan, P.; Feldmann, H.; Andreae, M. O.

2010-12-01

122

Beta-elements and divided congruences  

CERN Document Server

The f-invariant is an injective homomorphism from the 2-line of the Adams-Novikov spectral sequence to a group which is closely related to divided congruences of elliptic modular forms. We compute the f-invariant for two infinite families of beta-elements and explain the relation of the arithmetic of divided congruences with the Kervaire invariant one problem.

Hornbostel, J; Hornbostel, Jens; Naumann, Niko

2005-01-01

123

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

International Nuclear Information System (INIS)

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

124

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

Science.gov (United States)

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

Bearman, Gonzalo; Stevens, Michael P

2014-01-01

125

Electric force microscopy investigation of the microstructure of thick film resistors  

Science.gov (United States)

Maps of the electric field distribution on the surface of thick film resistors (TFRs) have been acquired by using electric force microscopy (EFM). TFRs based on various types of conducting phases (Bi-ruthenate, Pb-ruthenate, or RuO2) and with different volume fractions in the glassy matrix have been examined. Scanning electron microscopy, x-ray energy dispersive spectroscopy and x-ray diffraction have been used to correlate the EFM results to the morphological, microchemical, and structural characteristics of the samples. The evolution of the TFRs microstructure and the segregation characteristic with the firing conditions have been investigated. The results showed that the concentration of the electric field around the conductive grains is a general feature of all the films, independently of the resistor composition, and a meander-like path of charge carriers on a microscopic scale has been assessed. The observations also indicated that at high firing temperatures the segregated structure did not disappear, but on the contrary was enhanced. All the results are critically discussed in relation to the electrical and piezoresistive properties of the TFRs and suggestions for new models to correlate the microstructure and the electric properties are presented.

Alessandrini, A.; Valdrè, G.; Morten, B.; Prudenziati, M.

2002-10-01

126

A New Control Method of a Large-Capacity Capacitor Simulator with an Inner Series Resistor  

Science.gov (United States)

This paper proposes a new control method for the previously proposed large-capacity capacitor simulator, which can perform an inner series resistor of the EDLCs. In the proposed large-capacity capacitor simulator, one of three legs performs a bi-directional dc-dc converter. The others are used for a single-phase PWM rectifier. In the charging operation of the proposed large-capacity simulator, one-leg is used as a boost converter. Most power, which is stored in the proposed simulator, is injected to the utility through the PWM rectifier. In the discharging operation, the one-leg performs a buck converter. Most power, which is supplied to the load, is from the utility through the PWM rectifier. Thus the proposed simulator performs a large-capacity capacitor with an inner resistor in both charging and discharging operations. The basic principle of the proposed simulator is discussed in detail. The validity and excellent practicability of the proposed control method for the large-capacity capacitor simulator are confirmed using PSIM software.

Tanaka, Atsushi; Hiraki, Eiji; Tanaka, Toshihiko

127

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

International Nuclear Information System (INIS)

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

128

Location and Lateral Migration of Drainage Divides  

Science.gov (United States)

We investigate the mechanisms driving the lateral migration of drainage divides on hillslopes experiencing dispersive-like soil creep due to changes in downcutting rates in the channels bordering these hillslopes. If two channels are downcutting at the same rate and are at the same elevation the hillslopes will be symmetric about the divide. This symmetry may be broken by a vertical offset in the elevation of the channels or by unequal rates of channel incision. The rate and distance of divide offset will depend on the dominant sediment transport mechanism on the hillslope. For hillslopes undergoing sediment transport that is linearly proportional to the slope, the divide offset distance is one quarter of the ratio of the vertical offset of the channels to the relief of the symmetric hillslope. If channels are downcutting at different rates, the speed of the divide migration will only depend on the ratio of the two downcutting rates and the density ratio, which is the ratio of the dry bulk density of the bedrock to the dry bulk density of the soil. The density ratio plays a fundamental role in determining the transient response of the divide if the bounding channels are lowering at the same time-averaged downcutting rate but whose instantaneous incision rates vary. Lower density ratios lead to faster transient responses of the divide to changes in channel downcutting rates. Other parameters that affect the transient response of the divide are the magnitude of transient differences in downcutting between the two channels, the time averaged incision rate, and a ratio of the relaxation time of the hillslope to the particle residence time on the hillslope. The soil depth profile reacts to transient changes in downcutting at a different rate than surface topography. Hillslopes experiencing transient channel downcutting may have surface topography that is symmetric about the divide but will at the same time have a soil depth profile that is asymmetric. The implications for long term adjustments of drainage basin morphology are considered.

Mudd, S. M.; Furbish, D. J.

2004-12-01

129

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

130

Frequency divider is free of spurious outputs  

Science.gov (United States)

Frequency divider provides sixteen output states free of spurious pulses from four input circuits. The input is binary coded, and a change of one in the input only changes the number of output states by one.

Mc Dermond, D.

1966-01-01

131

Ultra-low-noise regenerative frequency divider.  

Science.gov (United States)

We designed ultra-low-noise regenerative divide-by- 2 circuits that operate at input frequencies of 10, 20, and 40 MHz. We achieved output-referred single-sideband residual phase noise equal to -164 dBc/Hz at 10 Hz offset and estimated residual Allan deviation, ?(y)(?) less than 3 × 10(-15)?(-1) for a single divider, which is, to our knowledge, the lowest noise of any divider ever reported at these frequencies. To measure such a low noise, we also built a cross-spectrum measurement system that has a noise floor of -175 dBc/Hz at 10 Hz offset from the carrier frequency. The low noise of the divider and the measurement system are achieved by using custom-built mixers/phase detectors that use 2N2222A bipolar junction transistors (BJTs) in a conventional double-balanced diode ring. PMID:23192826

Hati, Archita; Nelson, Craig W; Barnes, Corey; Lirette, Danielle; DeSalvo, Jason A; Howe, David A

2012-11-01

132

Diminishing Digital Divide: Dynamics and Implications  

Directory of Open Access Journals (Sweden)

Full Text Available A consensus is swiftly emerging regarding the democratizing impacts of moderncommunication technologies. However, the major challenge in this perspective comes from ‘digitaldivide’ which refers to ‘haves’ and ‘have not’ of the modern communication technologies and accessto information. This divide, primarily stems from the existing socioeconomic divides. However, inperspective of existing scholarly research and quantitative data on the issue, it is argued that digitaldivide is diminishing gradually. The advancements in technology particularly the integrative featuresof modern technology along with increasing affordability is denting the digital divide. The ebbingaway of digital divide has various implications for individual, civil society and state.This articleelaborates this issue at length by juxtaposing the findings from the existing research and presents acompact schematic model for better comprehension of the issue.

Muhammad Zubair Khan

2012-12-01

133

Skew Divided Difference Operators and Schubert Polynomials  

Directory of Open Access Journals (Sweden)

Full Text Available We study an action of the skew divided difference operators on the Schubert polynomials and give an explicit formula for structural constants for the Schubert polynomials in terms of certain weighted paths in the Bruhat order on the symmetric group. We also prove that, under certain assumptions, the skew divided difference operators transform the Schubert polynomials into polynomials with positive integer coefficients.

Anatol N. Kirillov

2007-05-01

134

A Digital Divide in Political Participation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Early on, optimistic observers speculated that the Internet might bolster political participation, as it provides access to a wealth of information and facilitates political conversation and association. Yet, digital divide research was able to show that not all citizens benefit equally from the opportunities provided by new media. A divide in Internet use and engagement might therefore propound pre-existing inequalities in political participation. Based on a survey conducted among Internet u...

Christian Pieter Hoffmann; Christoph Lutz

2014-01-01

135

Magnetic-Flux-Compensated Voltage Divider  

Science.gov (United States)

A magnetic-flux-compensated voltage-divider circuit has been proposed for use in measuring the true potential across a component that is exposed to large, rapidly varying electric currents like those produced by lightning strikes. An example of such a component is a lightning arrester, which is typically exposed to currents of the order of tens of kiloamperes, having rise times of the order of hundreds of nanoseconds. Traditional voltage-divider circuits are not designed for magnetic-flux-compensation: They contain uncompensated loops having areas large enough that the transient magnetic fluxes associated with large transient currents induce spurious voltages large enough to distort voltage-divider outputs significantly. A drawing of the proposed circuit was not available at the time of receipt of information for this article. What is known from a summary textual description is that the proposed circuit would contain a total of four voltage dividers: There would be two mixed dividers in parallel with each other and with the component of interest (e.g., a lightning arrester), plus two mixed dividers in parallel with each other and in series with the component of interest in the same plane. The electrical and geometric configuration would provide compensation for induced voltages, including those attributable to asymmetry in the volumetric density of the lightning or other transient current, canceling out the spurious voltages and measuring the true voltage across the component.

Mata, Carlos T.

2005-01-01

136

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

Science.gov (United States)

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

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

2014-07-01

137

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

International Nuclear Information System (INIS)

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

138

Use of a Pre-Insertion Resistor to Minimize Zero-Missing Phenomenon and Switching Overvoltages  

DEFF Research Database (Denmark)

With the increasing use of High-Voltage Cables, which have different electric characteristics from Overhead Lines, phenomenon like current zero-missing start to appear more often on the transmission systems. Methods to prevent zero-missing phenomenon are still being studied and compared to see which countermeasure works the best. Technically the best way to avoid zero-missing phenomenon produces very high switching overvoltages, making the operator to choose to either avoid the zero-missing phenomenon or to minimize the switching transients. This paper presents a method of determining an optimal value of the resistance of the pre-insertion resistor that results in minimizing both the zero-missing phenomenon and switching overvoltages simultaneously.

Bak, Claus Leth; da Silva, Filipe Miguel Faria

2009-01-01

139

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

Science.gov (United States)

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

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

1998-04-01

140

Resistor Type Superconducting Fault Current Limiter: Optimum Shunt Resistance Determination to Enhance Power System Transient Stability  

Science.gov (United States)

In power systems, Resistor type Superconducting Fault Current Limiters (RSFCL) can limit the prospective short-circuit currents to lower levels, so that the underrated switchgears can operate safely. Besides, RSFCLs can enhance the power system transient stability if they are accompanied by appropriate shunt resistances. This paper presents a method of optimum shunt resistance determination for transient stability improvement. The method is based on minimization of rotor kinetic energy oscillations. Meanwhile to make it more comprehensible, the method is utilized to determine the shunt resistances of three RSFCLs installed in a 9-bus 3-generator sample network. All of the simulations have been carried out by EMTP/ATP. The paper begins by modeling an RSFCL. Then RSFCL critical current determination is discussed in a model system. Finally, a method of optimum shunt resistance determination for transient stability improvement is presented.

Hooshyar, Hossein; Heydari, Hossein; Savaghebi, Mehdi; Sharifi, Reza

 
 
 
 
141

Functional Model of Carbon Nanotube Programmable Resistors for Hybrid Nano/CMOS Circuit Design  

Science.gov (United States)

Hybrid Nano (e.g. Nanotube and Nanowire) /CMOS circuits combine both the advantages of Nano-devices and CMOS technologies; they have thus become the most promising candidates to relax the intrinsic drawbacks of CMOS circuits beyond Moore’s law. A functional simulation model for an hybrid Nano/CMOS design is presented in this paper. It is based on Optically Gated Carbon NanoTube Field Effect Transistors (OG-CNTFET), which can be used as 2-terminal programmable resistors. Their resistance can be adjusted precisely, reproducibly and in a non-volatile way, over three orders of magnitude. These interesting behaviors of OG-CNTFET promise great potential for developing the non-volatile memory and neuromorphic adaptive computing circuits. The model is developed in Verilog-A language and implemented on Cadence Virtuoso platform with Spectre 5.1.41 simulator. Many experimental parameters are included in this model to improve the simulation accuracy.

Zhao, Weisheng; Agnus, Guillaume; Derycke, Vincent; Filoramo, Ariana; Gamrat, Christian; Bourgoin, Jean-Philippe

142

Characterization measurements of the wideband infrared scene projector resistor array: II  

Science.gov (United States)

Kinetic Energy Weapon (KEW) program under the Ballistic Missile Defense Office (BMDO) need high fidelity, fast framing infrared (IR) imaging seekers. As imaging sensors have matured to support BMDO, the complexity of functions assigned to the KEW weapon systems has amplified the necessity for robust hardware-in-the-loop (HWIL) simulation facilities to reduce program risk. Tactical weapon systems are also turning to imaging focal plane array seekers. They too require more sophisticated HWIL testing. The IR projector, an integral component of a HWIL simulation, must reproduce the real world with enough fidelity that the unit- under-test's software will respond to the projected scenario of images as through it were viewing the real world. The MOSFET resistor array IR scene projector shows great promise in cryogenic vacuum chamber as well as room temperature testing. Under the Wideband Infrared Scene Projector (WISP) program, a second generation resistor array has been delivered and characterized. Characterization measurements to include: spectral output, dynamic range capability, apparent temperature, rise time, and fall time, have been accomplished on the second generation array at the Kinetic Kill Vehicle Hardware-in-the Loop Simulator facility and the Guided Weapons Evaluation Facility, Eglin AFB, FL. Dynamic range output exceeds to WISP specification. Other parameters such as, rise time etc., either meet or are close to meeting system specifications. The final design of the WISP arrays is currently in progress based on these results. Also reported on in this document are performance measurements of the analog drive electronics' noise level, accuracy and resolution. The performance of the drive electronics had to be established before any radiometric output could be measured.

Jones, Lawrence E.; Stockbridge, Robert G.; Andrews, Allen R.; Herald, W. Larry; Guertin, Andrew W.

1997-07-01

143

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

144

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

145

Closing the Digital Divide in Latin America  

Science.gov (United States)

The new era of the High Energy Physics experiments motivates physicists to build new computing system to take in account of the produced data by LHC experiments (about 10 Petabytes per year). As these Experiments are performed in International Collaborations at world level, ICFA-International Committee for Future Accelerators create the SCIC/Digital Divide --Standing Committee on International Connectivity/Digital Divide to get information about the situation of the network in each country and its connectivity with the world. A report can be get it in the URL https://icfa-scic.web.cern.ch/ICFA-SCIC/. In this talk we intend to update the information about Digital Divide on the Latin America region, showing the possibilities for the near future participate of the LHC collaborations.

Santoro, Alberto

2007-04-01

146

Symbols and the Divided Self in Janus  

Directory of Open Access Journals (Sweden)

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

Xiaomi ZHANG

2014-03-01

147

Divide-and-Conquer Matrix Factorization  

CERN Document Server

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

Mackey, Lester; Jordan, Michael I

2011-01-01

148

Bruce B Unit 6 divider plate sealing skin installation  

International Nuclear Information System (INIS)

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

149

Bridging the Digital Divide in Higher Education.  

Science.gov (United States)

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

Treviranus, Jutta; Coombs, Norman

150

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

151

Improved frequency divider employs transistor avalanche effect  

Science.gov (United States)

New frequency divider circuit can be synchronized over a wider input control frequency range, has greater phase stability, and is less sensitive to temperature changes than conventional synchronized oscillators. The new circuit uses the avalanche breakdown mode of operation of transistors.

Johns, C. E.

1967-01-01

152

Project DIVIDE Instrument Development. Technical Report # 0810  

Science.gov (United States)

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

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

2008-01-01

153

Capacitive divider for output voltage measurement of intense electron beam accelerator  

International Nuclear Information System (INIS)

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

154

Analyses of power output of piezoelectric energy-harvesting devices directly connected to a load resistor using a coupled piezoelectric-circuit finite element method.  

Science.gov (United States)

This paper presents, for the first time, a coupled piezoelectric-circuit finite element model (CPC-FEM) to analyze the power output of a vibration-based piezoelectric energy-harvesting device (EHD) when it is connected to a load resistor. Special focus is given to the effect of the load resistor value on the vibrational amplitude of the piezoelectric EHD, and thus on the current, voltage, and power generated by the device, which are normally assumed to be independent of the load resistor value to reduce the complexity of modeling and simulation. The presented CPC-FEM uses a cantilever with a sandwich structure and a seismic mass attached to the tip to study the following characteristics of the EHD as a result of changing the load resistor value: 1) the electric outputs: the current through and voltage across the load resistor; 2) the power dissipated by the load resistor; 3) the displacement amplitude of the tip of the cantilever; and 4) the shift in the resonant frequency of the device. It is found that these characteristics of the EHD have a significant dependence on the load resistor value, rather than being independent of it as is assumed in most literature. The CPC-FEM is capable of predicting the generated output power of the EHD with different load resistor values while simultaneously calculating the effect of the load resistor value on the displacement amplitude of the tip of the cantilever. This makes the CPC-FEM invaluable for validating the performance of a designed EHD before it is fabricated and tested, thereby reducing the recurring costs associated with repeat fabrication and trials. In addition, the proposed CPC-FEM can also be used for producing an optimized design for maximum power output. PMID:19574142

Zhu, Meiling; Worthington, Emma; Njuguna, James

2009-07-01

155

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

156

New Fabrication Process of Single-Crystalline Silicon Islands Using Double Diffusion: Application to a Heating Resistor of a Thermal Inkjet Printhead  

Science.gov (United States)

The n+-type silicon island was fabricated using double diffusion, selective anodization and oxidation of silicon. The island was applied as a heating resistor of a thermal inkjet printhead. The heating resistor has good uniformity of ±5% and good endurance of 108 cycles under electrical stresses. In the inkjet printhead structure, high-quality thermal oxide can be used as a passivation layer and a thick thermal barrier oxide under heating resistors can be easily achieved. The diameter of ejected ink dots with a nozzle diameter of 35 µm was about 100 µm. There were no satellites on the paper.

Lee, Choon-Sup; Lee, Jae-Duk; Han, Chul-Hi

1998-12-01

157

Low phase noise digital frequency divider  

Science.gov (United States)

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

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

1973-01-01

158

Divided or kissing nevus of the penis.  

Science.gov (United States)

The divided or kissing nevus is an unusual congenital melanocytic nevus. By definition, these nevi appear on skin that separates during embryological development. These lesions have been reported on the eyelids, fingers, and rarely the penis. We describe an 18 year old uncircumcised male who presented with an asymptomatic darkly pigmented patch on the glans penis. He reported that the lesion had appeared recently and was enlarging. Physical examination revealed a second symmetric lesion on the adjacent foreskin. Punch biopsy of the lesion on the glans penis showed abundant intradermal melanocytes devoid of mitoses and atypia, consistent with an intradermal melanocytic nevus. Based on the benign histologic nature and clinical exam, the lesion was diagnosed as a divided or kissing nevus of the penis. Proposed treatments include excision and grafting as well as Nd:YAG laser therapy. However, these patients may be safely monitored with regular follow-up skin examinations because there is minimal risk of malignant transformation. PMID:24139368

Hardin, Carolyn A; Tieu, Kathy D

2013-10-01

159

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

160

Inductive voltage divider calibration with sampling method  

Science.gov (United States)

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

Corminboeuf, David; Overney, Frédéric

2014-08-01

 
 
 
 
161

Inductive voltage divider calibration with sampling method  

Directory of Open Access Journals (Sweden)

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

Corminboeuf David

2014-01-01

162

The Russian-Ukrainian Earnings Divide  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Ethnic differences are often considered to be powerful sources of diverse economic behavior. In this paper, we investigate whether and how ethnicity affects Ukrainian labor market outcomes. Using micro data from the Ukrainian Longitudinal Monitoring Survey (ULMS) and Oaxaca-Blinder decomposition of earnings, we find a persistent and rising labor market divide between ethnic Russians and Ukrainians throughout Ukraine's transition era. We establish that language rather than nationality is the k...

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

2006-01-01

163

Media Literacy in Times of Media Divides  

Directory of Open Access Journals (Sweden)

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

Kaja Žuran

2013-12-01

164

REGENERATIVE GAS TURBINES WITH DIVIDED EXPANSION  

DEFF Research Database (Denmark)

Recuperated gas turbines are currently drawing an increased attention due to the recent commercialization of micro gas turbines with recuperation. This system may reach a high efficiency even for the small units of less than 100 kW. In order to improve the economics of the plants, ways to improve their efficiency are always of interest. Recently, two independent studies have proposed recuperated gas turbines to be configured with the turbine expansion divided, in order to obtain higher efficiency. The idea is to operate the system with a gas generator and a power turbine, and use the gas from the gas generator part for recuperation ahead of the expansion in the power turbine. The present study is more complete than the predecessors in that the ranges of the parameters have been extended and the mathematical model is more realistic using an extensive simulation program. It is confirmed that the proposed divided expansion can be advantageous under certain circumstances. But, in order for todays micro gas turbines to be competitive, the thermodynamic efficiencies will have to be rather high. This requires that all component efficiencies including the recuperator effectiveness will have to be high. The advantages of the divided expansion manifest themselves over a rather limited range of the operating parameters, that lies outside the range required to make modern micro turbines economically competitive.

Elmegaard, Brian; Qvale, Einar BjØrn

2004-01-01

165

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

166

Doped nanocrystalline ZnO powders for non-linear resistor applications by spray pyrolysis method.  

Science.gov (United States)

Homogeneous and doped nanocrystalline ZnO powders (30-200 nm) were synthesized by spray pyrolysis technique. The spray pyrolysed powders were calcined in the temperature range of 500-750 degrees C. Formation of insulating pyrochlore phase started from 700 degrees C during the calcination itself. The calcined powders were compacted and sintered at different temperatures ranging from 900-1200 degrees C for 0.5-4 h. The densification behavior was found to be dependent on calcination temperature of the nanopowder. The resulting discs were found to have density (5.34-5.62 g/cc) in the range of 96-99% of theoretical density. The breakdown voltage value obtained for the nanopowder based non-linear resistor is 10.3 kV/cm with low leakage current density of 0.7 microA/cm2 and coefficient of nonlinearity as high as 193. The activation energy for grain growth of the doped ZnO nanopowder powders is 449.4 +/- 15 kJ/mol. PMID:19916460

Hembram, Kaliyan; Vijay, R; Rao, Y S; Rao, T N

2009-07-01

167

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

International Nuclear Information System (INIS)

The SiPMs with quenching resistors integrated into bulk epitaxial silicon have been investigated at the Novel Device Laboratory (NDL), Beijing Normal University, China. The aim is to alleviate the conflict between the high photon detection efficiency (PDE) and high APD cell density or dynamic range encountered by conventional SiPM so that this promising detector can be applied where both large dynamic range and high PDE are required simultaneously. We report herein the latest progresses on the SiPM with 104/mm2 micro-cell density and 0.5 mm×0.5 mm, 1 mm×1 mm as well as 20 ?m×1.8 mm effective area, which have been designed and fabricated at NDL. Application of the strip SiPM with a gated photon counting technique on the measurement of TNT Raman spectroscopy is demonstrated, and the feasibility for extending SiPMs in conjunction with Nuclear Instrumentation Modules (NIM) based electronics to the field of ultra-weak spectroscopy is verified.

168

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

2013-07-01

169

Combined TiN- and TaN temperature compensated thin film resistors  

International Nuclear Information System (INIS)

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

170

Accelerometers and force sensing resistors for optimal control of walking of a hemiplegic.  

Science.gov (United States)

We developed a method for use of accelerometers and force sensing resistors (FSRs) within an optimal controller of walking for hemiplegic individuals. The data from four dual-axis accelerometers and four FSRs were inputs, while six muscle activation profiles were outputs. The controller includes two stages: 1) estimating the target gait pattern using artificial neural networks; and 2) optimal control minimizing tracking errors (from the estimated gait pattern) and muscle efforts. The controller was tested using data collected from six healthy subjects walking at five speeds (0.6-1.4 m/s). The average root mean square errors (RMSEs) normalized by the peak-to-peak value of the target signals [normalized RMSE (NRMSE)] were below 6%, 7%, 8%, and 3% for estimation of joint angles, hip acceleration, ground reaction force, and movement of the center of pressure, respectively. Using the estimated data as inputs, the simulation generated the target healthy-like gait patterns and reproducible muscle activation profiles in 90% of 300 tested gait trials. Overall tracking NRMSE was between 2% and 9%. The optimal controller was developed for testing the feasibility of healthy-like gait patterns in hemiplegic individuals, and generating a knowledge base that is required for the synthesis of a sensory-driven control of walking assisted by functional electrical stimulation. PMID:18632360

Došen, Strahinja; Popovi, Dejan B

2008-08-01

171

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

International Nuclear Information System (INIS)

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

172

Prevention of Transformer Saturation at a Black Start by Resistor Insertion of 500kV CB  

Science.gov (United States)

A generating plant can not energize longer transmission lines at once after blackout. The generating plant energize shorter transmission lines firstly, then circuit breaker turns on to connect other transmission lines through the transformer. Transient over voltage oscillation may occur in the transmission lines caused by the resonance of the transmission line. It is reported that the peak voltage exceeds more than 2p.u. when the non-sinusoidal wave voltage caused by saturation in the transformer core excites the resonated transmission line. This paper describes the effect for preventing saturation of transformer by turning on contactors with appropriate resistors before main contactors of the 500kV circuit breaker. The first part presents the mechanism of preventing saturation in the transformer core by pre-resistor insertion of 500kV circuit breaker. The second part presents the expected effect in the actual power system simulated by analytical model using a transients simulation program, EMTP.

Nagashima, Hiroshi; Kosugi, Narifumi; Shimojo, Toshikazu; Furukawa, Nobuhiko; Kusunoki, Kiyoshi; Sugeta, Takayuki

173

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

International Nuclear Information System (INIS)

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

174

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

Science.gov (United States)

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

Chang, Kuo-Tsai

2007-01-01

175

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

176

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

International Nuclear Information System (INIS)

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

177

Secant method with regularly continuous divided differences  

Science.gov (United States)

We offer a convergence analysis of the secant method for solving nonlinear operator equations in Banach spaces using Kantorovich's technique of majorization. In contrast with other known convergence analyses of this method, ours is based on a different continuity characteristic of the divided difference operator (called regular continuity) which is more general (but not too general) and more flexible than those used by other researchers. As we show, it allows to obtain broader convergence domains and tighter error bounds. Another distinctive feature of our analysis is the use of a functional equation for precise description of convergence domain of the majorant generator (a system of difference equations).

Galperin, A.

2006-09-01

178

A 7-27 GHz DSCL divide-by-2 frequency divider  

International Nuclear Information System (INIS)

This paper presents the design and analysis of a high speed broadband divide-by-2 frequency divider. The proposed divider is a dynamic source-coupled logic (DSCL) structure formed with two dynamic-loading master-slave D latches, which enables high frequency operation and low power consumption. This divider exhibits a wide locking range from 7-27 GHz and the minimum power consumption is only 1.22 mW from a 1.2 V supply. The input sensitivity is as low as ?25.4 dBm across the operating frequency range. This chip occupies 685 × 430 ?m2 area with two on-chip spiral inductors in 90 nm CMOS process.

179

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 ...

PRAVEENKUMAR. KUMBARGOUDAR

2013-01-01

180

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

Background: Botswana is putting in place initiatives towards establishing itself as a knowledgebased economy. Transformation from a resource-based to a knowledge-based economy is partly hinged on innovation, research and development capability, knowledge channels, and the funding of research and development activities.

Objectives: Bridging the digital divide and narrowing the intra-national divide brings about global informatio...

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

2011-01-01

 
 
 
 
181

Cortical imaging on a head template: a simulation study using a resistor mesh model (RMM).  

Science.gov (United States)

The T1 head template model used in Statistical Parametric Mapping Version 2000 (SPM2), was segmented into five layers (scalp, skull, CSF, grey and white matter) and implemented in 2 mm voxels. We designed a resistor mesh model (RMM), based on the finite volume method (FVM) to simulate the electrical properties of this head model along the three axes for each voxel. Then, we introduced four dipoles of high eccentricity (about 0.8) in this RMM, separately and simultaneously, to compute the potentials for two sets of conductivities. We used the direct cortical imaging technique (CIT) to recover the simulated dipoles, using 60 or 107 electrodes and with or without addition of Gaussian white noise (GWN). The use of realistic conductivities gave better CIT results than standard conductivities, lowering the blurring effect on scalp potentials and displaying more accurate position areas when CIT was applied to single dipoles. Simultaneous dipoles were less accurately localized, but good qualitative and stable quantitative results were obtained up to 5% noise level for 107 electrodes and up to 10% noise level for 60 electrodes, showing that a compromise must be found to optimize both the number of electrodes and the noise level. With the RMM defined in 2 mm voxels, the standard 128-electrode cap and 5% noise appears to be the upper limit providing reliable source positions when direct CIT is used. The admittance matrix defining the RMM is easy to modify so as to adapt to different conductivities. The next step will be the adaptation of individual real head T2 images to the RMM template and the introduction of anisotropy using diffusion imaging (DI). PMID:18629625

Chauveau, Nicolas; Franceries, Xavier; Aubry, Florent; Celsis, Pierre; Rigaud, Bernard

2008-09-01

182

A unified resistor-capacitor model for impedance, dielectrophoresis, electrorotation, and induced transmembrane potential.  

Science.gov (United States)

Dielectric properties of suspended cells are explored by analysis of the frequency-dependent response to electric fields. Impedance (IMP) registers the electric response, and kinetic phenomena like orientation, translation, deformation, or rotation can also be analyzed. All responses can generally be described by a unified theory. This is demonstrated by an RC model for the structural polarizations of biological cells, allowing intuitive comparison of the IMP, dielectrophoresis (DP), and electrorotation (ER) methods. For derivations, cells of prismatic geometry embedded in elementary cubes formed by the external solution were assumed. All geometrical constituents of the model were described by parallel circuits of a capacitor and a resistor. The IMP of the suspension is given by a meshwork of elementary cubes. Each elementary cube was modeled by two branches describing the current flow through and around the cell. To model DP and ER, the external branch was subdivided to obtain a reference potential. Real and imaginary parts of the potential difference of the cell surface and the reference reflect the frequency behavior of DP and ER. The scheme resembles an unbalanced Wheatstone bridge, in which IMP measures the current-voltage behavior of the feed signal and DP and ER are the measuring signal. Model predictions were consistent with IMP, DP, and ER experiments on human red cells, as well as with the frequency dependence of field-induced hemolysis. The influential radius concept is proposed, which allows easy derivation of simplified equations for the characteristic properties of a spherical single-shell model on the basis of the RC model. PMID:9675212

Gimsa, J; Wachner, D

1998-08-01

183

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

Science.gov (United States)

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

McCloskey, K M

2000-10-01

184

The Bread Book Multiplying and Dividing  

CERN Document Server

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

Hyland, Tony

2008-01-01

185

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

Scientific Electronic Library Online (English)

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

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

2013-12-01

186

Water hammer  

International Nuclear Information System (INIS)

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

187

Steady flow in a dividing pipe  

Science.gov (United States)

The high Reynolds number flow through a circular pipe divided along a diameter by a semi-infinite splitter plate is considered. Matched asymptotic expansions are used to analyse the developing flow, which is decomposed into four regions: a boundary layer of Blasius type growing along the plate, an inviscid core, a viscous layer close to the curved wall and a nonlinear corner region. The core solution is found numerically, initially in the long-distance down-pipe limit and thereafter the full problem is solved using down-pipe Fourier transforms. The accuracy in the corners of the semicircular cross-section is improved by subtracting out the singularity in the velocity perturbation. The linear viscous wall layer is solved analytically in terms of a displacement function determined from the core. A plausible structure for the corner region and equations governing the motion therein are presented although no solution is attempted. The presence of the plate has little effect ahead of the bifurcation, but wall shear on the curved wall is found to increase from its undisturbed value downstream.

Blyth, M. G.; Mestel, A. J.

1999-12-01

188

Quantitative Measurement of the Digital Divide  

Science.gov (United States)

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

Cottrell, Roger

2007-04-01

189

The Gender Digital Divide in Developing Countries  

Directory of Open Access Journals (Sweden)

Full Text Available Empirical studies clearly show that women in the developing world have significantly lower technology participation rates than men; a result of entrenched socio-cultural attitudes about the role of women in society. However, as studies are beginning to show, when those women are able to engage with Internet technology, a wide range of personal, family and community benefits become possible. The key to these benefits is on-line education, the access to which sets up a positive feedback loop. This review gives an overview of the digital divide, before focusing specifically on the challenges women in developing countries face in accessing the Internet. Current gender disparities in Internet use will be outlined and the barriers that potentially hinder women’s access and participation in the online world will be considered. We will then look at the potential opportunities for women’s participation in a global digital society along with a consideration of current initiatives that have been developed to mitigate gender inequity in developing countries. We will also consider a promising avenue for future research.

Amy Antonio

2014-10-01

190

Bridging the Divide between Science and Journalism  

Directory of Open Access Journals (Sweden)

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

Marincola Francesco M

2010-03-01

191

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

Science.gov (United States)

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

Aghili Yajadda, Mir Massoud

2014-10-01

192

A study of random resistor-capacitor-diode networks to assess the electromagnetic properties of carbon nanotube filled polymers  

Science.gov (United States)

We determined the frequency dependent effective permittivity of a large ternary network of randomly positioned resistors, capacitors, and diodes. A linear circuit analysis of such systems is shown to match the experimental dielectric response of single-walled carbon nanotube (SWCNT) filled polymers. This modeling method is able to reproduce the two most important features of SWCNT filled composites, i.e., the low frequency dispersion and dipolar relaxation. As a result of the modeling important physical conclusion proved by the experimental data was done: the low frequency behavior of SWCNT-filled polymer composites is mostly caused by the fraction of semiconducting SWCNTs.

Bychanok, D. S.; Paddubskaya, A. G.; Kuzhir, P. P.; Maksimenko, S. A.; Brosseau, C.; Macutkevic, J.; Bellucci, S.

2013-12-01

193

Study on method of dividing plume emergency planning zone in nuclear power plants  

International Nuclear Information System (INIS)

Considering the safety features of different types of reactors, different methods of dividing plume emergency planning zone (PEPZ) were compared and analyzed, and then systematically classified according to the reactor types. The applicable methods of dividing PEPZ for different reactor types were proposed. Finally, the methods were preliminary applied taking the High-Temperature gas-cooled Reactor-Pebble bed Module (HTR-PM) as an example. The preliminary study results show that, the site boundary of HTR-PM meet the criteria of dividing PEPZ, and compared with the large light water reactors, its PEPZ can be significantly decreased. (authors)

194

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2012-05-15

195

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

International Nuclear Information System (INIS)

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

196

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 SciELO Brazil | Language: Portuguese 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 proces [...] so em escala microscópica, descreveram-se os resultados de um experimento com plantas cujo sistema radicular foi dividido entre camadas de solo com propriedades hidráulicas contrastantes. Um experimento de lisímetro dividido com plantas de sorgo foi realizado em Piracicaba-SP. Quatro lisímetros com dois compartimentos separados fisicamente (split-pot) foram construídos e preenchidos com material de dois tipos de solo de diferentes classes texturais (um solo de textura média - AR e outro de textura argilosa - AG). Durante um mês e meio foi imposto um regime hídrico, alternando a irrigação entre os compartimentos. O teor de água nos compartimentos dos lisímetros foi monitorado com TDR e tensiômetros. O material dos dois solos foi analisado conforme método-padrão quanto às suas propriedades de retenção e condução da água. A densidade radicular foi determinada por pesagem no fim do experimento, tendo ficado em torno de duas vezes maior no solo AR do que no AG. Observou-se que a extração de água ocorreu preferencialmente do compartimento do lisímetro com maior potencial de fluxo matricial. Em certas ocasiões houve transferência de água do lado de maior para o de menor potencial de fluxo matricial, com a liberação da água ao solo pelo sistema radicular (hydraulic lift). Para compensar o efeito da heterogeneidade da distribuição radicular e da atividade radicular, incluiu-se, no modelo, um fator empírico f de correção. O modelo testado descreveu bem 80 % das observações com a utilização de valores de f de 0,01506 e 0,003713, para os solos AR e AG, respectivamente. O modelo simulou a liberação de água ao solo mais frequentemente do que ela ocorreu no experimento. Esse fato pode indicar que a resistência interna do sistema radicular, não contabilizada pelo modelo, pode ter papel importante nas relações hídricas na rizosfera. 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 wa [...] s described in which the root system of plants penetrated different soil layers with contrasting hydraulic properties. Four lysimeters containing two physically divided compartments were built and filled with material of two soils with different texture (a medium textured soil - AR and a clayey soil - AG). During a month and a half a water regime was imposed alternating the irrigation among the compartments. The soil water content in the compartments was measured with TDR and tensiometers. Soil hydraulic properties - retention and conductivity - were analyzed by standard methods. Root density was determined by weighing at the end of the experiment, resulting in values twice as high in AR than in AG soil. It was observed that water extraction occurred preferentially from the lysimeter compartments with the highest matric flux potential. Occasionally, water transfer from the compartment with higher matric flux potential to the lower one was observed, releasing water from root to soil (hydraulic lift). To compensate for the effect of heterogeneity of root distribution and root activity and soil-root contact, an empirical factor f was added to the model. Its value was determined by a numerical fitting procedure aiming at the highest correlation between model and observation in the four lysimeters. The model described 80% of the observations satisfactorily by using these f values, which were 0.01506 and 0.003713, respectively, for AR and AG. Model predic

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

1017-10-01

197

A Compound Generic Quantitative Framework for Measuring Digital Divide  

Directory of Open Access Journals (Sweden)

Full Text Available The term digital divide had been used in the literature to conceptualize the gap in using and utilizing information and communication technologies. Digital divide can be identified on different levels such as individuals, groups, societies, organizations and countries. On the other hand, the concept of e-Inclusion is coined to define activities needed to bridge digital divide. One of the most challenging research areas in digital divide that had been a subject for exhaustive studies is measuring digital divide. Researchers have proposed many metrics and indices to measure digital divide. However, most of the proposed measures are bivariate comparisons that reduce measurement to comparisons of Internet penetration rates or alike. This paper proposes a compound generic framework for quantitative measuring of digital divide on the individuals or group level. The proposed framework takes into account the context of the digital divide in each society.

Noureldien A. Noureldien

2014-07-01

198

Bridging the Digital Divide: – A Myth or Reality ?  

Directory of Open Access Journals (Sweden)

Full Text Available Researchers have been documenting about the digital divide between developing countries and developed countries since 1970’s. Some experts in areas like Public Policy, Communications, Business Management and Economics have also addressed the phenomenon of digital divide since the 1990’s. We are in the 21st century and still there is the same old talk of digital divide amongst these researchers. One wonders whether digital divide will continue forever and whether we will ever achieve a Technology that closes this gap. This paper attempts to investigate ways to bridge the digital divide between Developing and Developed Countries and explore facts about Digital Divide that might be of some interest to the reader. The contribution of this paper is in the way this digital divide can be perceived as a reality or a myth given the number of years that have elapsed since this term was first coined by Lloyd Morrisett

Zablon Akoko Mbero

2013-06-01

199

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

CERN Document Server

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

200

Internal resistor of multi-functional tunnel barrier for selectivity and switching uniformity in resistive random access memory  

Science.gov (United States)

In this research, we analyzed the multi-functional role of a tunnel barrier that can be integrated in devices. This tunnel barrier, acting as an internal resistor, changes its resistance with applied bias. Therefore, the current flow in the devices can be controlled by a tunneling mechanism that modifies the tunnel barrier thickness for non-linearity and switching uniformity of devices. When a device is in a low-resistance state, the tunnel barrier controls the current behavior of the device because most of the bias is applied to the tunnel barrier owing to its higher resistance. Furthermore, the tunnel barrier induces uniform filament formation during set operation with the tunnel barrier controlling the current flow.

Lee, Sangheon; Woo, Jiyong; Lee, Daeseok; Cha, Euijun; Hwang, Hyunsang

2014-07-01

 
 
 
 
201

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

Science.gov (United States)

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

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

2014-02-12

202

To divide or not to divide: control of the bacterial cell cycle by environmental cues.  

Science.gov (United States)

Whether to divide or not is an important decision that nearly all cells have to make, especially bacteria that are exposed to drastic environmental changes. Under adverse conditions proliferation and growth could compromise cellular integrity and hence must be downregulated. To this end, bacteria have evolved sophisticated mechanisms to transduce environmental information into the cell cycle engine. Recent studies in Escherichia coli, Bacillus subtilis and Caulobacter crescentus indicate that these mechanisms often involve small molecule-based signaling, regulated proteolysis, as well as protein-protein interactions. Most of them delay replication initiation or septum formation by targeting the key regulators DnaA or FtsZ, respectively. Remarkably, while the targets are conserved, the precise mechanisms show a considerable degree of diversity among different species. PMID:24631929

Jonas, Kristina

2014-04-01

203

Qualification Approval Tests on resistance products Co.`s type {open_quotes}H{close_quotes} Carbon Composition resistors (0.2 and 40 Megohm)  

Energy Technology Data Exchange (ETDEWEB)

Engineering Work Requests ESE-48 & 49 established a program for performance of Qualification Approval Tests on RPC`s 0.2 and 40 meghom Carbon Composition Resistors. This report is an accounting of these tests wherein (50) samples of each component were subjected to QA tests per drawings 8O2C250 and 802C251. Tests are explained and results tabulated.

Dixon, L.W.

1960-03-25

204

Hybrid voltage divider used for high voltage pulsed power measurement  

International Nuclear Information System (INIS)

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

205

The Apply of Frequency Divider Circuit in Nuclear Electronics  

International Nuclear Information System (INIS)

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

206

Zones of silence: A framework beyond the digital divide  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Potter, Amelia Bryne

2006-01-01

207

Understanding the digital divide: A literature survey and ways forward  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Srinuan, Chalita; Bohlin, Erik

2011-01-01

208

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

The Digital Divide is an important issue with serious consequences, both for the individuals affected and society. With 90% of youths in urban areas using the Internet, there is a myth that the Digital Divide no longer exists amongst urban youths. Based on a random survey of 1639 youths, this study analyses the possibility of a digital divide along ethnic lines in Malaysia.. Findings indicate there are significant ethnic-based differences in home PC ownership and Internet connection. There ar...

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

2012-01-01

209

An Empirical Analysis of the Determinants of International Digital Divide  

Science.gov (United States)

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

Yun, Liu

210

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

Scientific Electronic Library Online (English)

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

Teresa Vaz, Martins; Raúl, Toral.

2012-06-01

211

Technique for extending the frequency range of digital dividers  

Science.gov (United States)

A technique for extending the frequency range of a presettable digital divider is described. The conventional digital divider consists of several counter stages with the count of each stage compared to a preselected number. When the counts for all stages are equal to the preselected numbers, an output pulse is generated and all stages are reset. For high input frequencies, the least significant stage of the divider has to be reset in a very short time. This limits the frequency that can be handled by the conventional digital divider. This invention provides a technique in which the second least significant and higher stages are reset and the least significant stage is permitted to free-run. Hence, the time in which the reset operation can be performed is increased thereby extending the frequency range of the divider.

Long, W. C.; Middleton, J. H. (inventors)

1973-01-01

212

A novel wideband low phase noise 2: 1 frequency divider  

International Nuclear Information System (INIS)

This paper describes a novel low-power wideband low-phase noise divide-by-two frequency divider. Hereby, a new D-latch topology is introduced. By means of conventional dynamic source-coupled logic techniques, the divider demonstrates a wideband with low phase noise by adding a switch transistor between the clock port and the couple node of the input NMOS pair in the D latch. The chip was fabricated in the 90-nm CMOS process of IBM. The measurement results show that the frequency divider has an input frequency range from 0.05 to 10 GHz and the phase noise is -159.8 dBc/Hz at 1 MHz offset from the carrier. Working at 10 GHz, the frequency divider dissipates a total power of 9.12 mW from a 1.2 V supply while occupying only 0.008 mm2 of the core die area. (semiconductor integrated circuits)

213

[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

214

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.

2004-05-01

215

Microwave regenerative frequency dividers with low phase noise.  

Science.gov (United States)

We demonstrate regenerative divide-by-two (halver) circuits with very low phase modulation (PM) noise at input frequencies of 18.4 GHz and 39.8 GHz. The PM noise of the 18.4 to 9.2 GHz divider pair was L(10 Hz)=-134 dB below the carrier in a 1 Hz bandwidth (dBc/Hz) and L(10 MHz)=-166 dBc/Hz, and the PM noise of the 39.8 GHz to 19.9 GHz divider pair was L(10 Hz)=-122 dBc/Hz and L(10 MHz)=-167 dBc/Hz. PMID:18238416

Ferre-Pikal, E S; Walls, F L

1999-01-01

216

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

217

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

International Nuclear Information System (INIS)

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

218

Unijunction frequency divider is free of backward loading  

Science.gov (United States)

Simple frequency divider composed of relaxation oscillators uses unijunction transistors to reduce backward loading to a minimum. This circuit design is applicable in timing devices and sync generators for television systems.

Fairbanks, A. F.

1965-01-01

219

Pulse swallowing frequency divider with low power and compact structure  

International Nuclear Information System (INIS)

A pulse swallowing frequency divider with low power and compact structure is presented. One of the DFFs in the divided by 2/3 prescaler is controlled by the modulus control signal, and automatically powered off when it has no contribution to the operation of the prescaler. The DFFs in the program counter and the swallow counter are shared to compose a compact structure, which reduces the power consumption further. The proposed multi-modulus frequency divider was implemented in a standard 65 nm CMOS process with an area of 28 × 22 ?m2. The power consumption of the divider is 0.6 mW under 1.2 V supply voltage when operating at 988 MHz. (semiconductor integrated circuits)

220

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

 
 
 
 
221

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

2012-12-01

222

The road to sustainability must bridge three great divides.  

Science.gov (United States)

The world's large and rapidly growing human population is exhausting Earth's natural capital at ever-faster rates, and yet appears mostly oblivious to the fact that these resources are limited. This is dangerous for our well-being and perhaps for our survival, as documented by numerous studies over many years. Why are we not moving instead toward sustainable levels of use? We argue here that this disconnection between our knowledge and our actions is largely caused by three "great divides": an ideological divide between economists and ecologists; an economic development divide between the rich and the poor; and an information divide, which obstructs communications between scientists, public opinion, and policy makers. These divides prevent our economies from responding effectively to urgent signals of environmental and ecological stress. The restoration of natural capital (RNC) can be an important strategy in bridging all of these divides. RNC projects and programs make explicit the multiple and mutually reinforcing linkages between environmental and economic well-being, while opening up a promising policy road in the search for a sustainable and desirable future for global society. The bridge-building capacity of RNC derives from its double focus: on the ecological restoration of degraded, overexploited natural ecosystems, and on the full socio-economic and ecological interface between people and their environments. PMID:20146772

Aronson, James; Blignaut, James N; de Groot, Rudolf S; Clewell, Andre; Lowry, Porter P; Woodworth, Paddy; Cowling, Richard M; Renison, Daniel; Farley, Joshua; Fontaine, Christelle; Tongway, David; Levy, Samuel; Milton, Suzanne J; Rangel, Orlando; Debrincat, Bev; Birkinshaw, Chris

2010-01-01

223

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

International Nuclear Information System (INIS)

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

224

Decision support system to divide a large network into suitable District Metered Areas.  

Science.gov (United States)

This paper presents a new approach to divide large Water Distribution Networks (WDN) into suitable District Metered Areas (DMAs). It uses a hydraulic simulator and two operational models to identify the optimal number of DMAs, their entry points and boundary valves, and the network reinforcement/replacement needs throughout the project plan. The first model divides the WDN into suitable DMAs based on graph theory concepts and some user-defined criteria. The second model uses a simulated annealing algorithm to identify the optimal number and location of entry points and boundary valves, and the pipes reinforcement/replacement, necessary to meet the velocity and pressure requirements. The objective function is the difference between the economic benefits in terms of water loss reduction (arising from the average pressure reduction) and the cost of implementing the DMAs. To illustrate the proposed methodology, the results from a hypothetical case study are presented and discussed. PMID:22508131

Gomes, Ricardo; Marques, Alfeu Sá; Sousa, Joaquim

2012-01-01

225

Bridging the Divide: Translating Landsat Research Into Usable Science  

Science.gov (United States)

Science has long served humankind. Breakthroughs in medicine have increased longevity and advances in technology have made modern-day conveniences possible. Yet, social benefits begotten by the environmental sciences, although critical for the survival of humanity, have not always been as widely recognized or used. To benefit today's rapidly growing population, the divides between environmental research, applied environmental science, and use of this information by decision makers must be bridged. Lessons about the translation from research to usable science can be learned from the four decades of Landsat history, and these lessons can serve as useful models for bridging the gaps between new technology, scientific research, and the use of that research and technology in real-world problem solving. In 1965, William Pecora, then-director of the U.S. Geological Survey, proposed the idea of a remote sensing satellite program to gather facts about natural resources of Earth. For the next seven years, an intense campaign showing the depth and diversity of satellite imagery applications was waged. This led to the 1972 launch of the first civilian land-observing satellite, Landsat 1. By 1975, successful application research based on Landsat 1 imagery prompted then-NASA Administrator Dr. James Fletcher to proclaim that if one space age development would save the world, it would be Landsat and its successor satellites. Thirty-four years of continual Landsat imaging and related-research has lead to the implementation of many socially beneficial applications, such as improved water management techniques, crop insurance fraud reduction, illicit crop inventories, natural disaster relief planning, continent-scale carbon estimates, and extensive cartographic advances. Despite these successes, the challenge of translating Landsat research into realized social benefits remains. Even in this geospatially-savvy era, the utility of Landsat largely escapes policymakers. Here, in an effort to better understand these challenges, we dissect the anatomy of some of Landsat's social benefit success stories and draw on the advice of Landsat experts to outline some of the important steps needed to facilitate the recognition of usable environmental science.

Rocchio, L. E.; Davis, A. L.

2006-12-01

226

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

Energy Technology Data Exchange (ETDEWEB)

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

Maebara, Sunao; Seki, Masami; Suganuma, Kazuaki [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment] [and others

1996-07-01

227

Europeans divided over austerity, want alternatives | EurActiv  

...Europeans divided over austerity, want alternatives | EurActiv specialreport-jobs-and-growth,euro-finance,future-eu,socialeurope,austerity package,crisis response,eurozone crisis,social dimension,social europe ...pipeline race The EU's role in global governance Health & Consumers Section homepage Austerity: Healthcare in hardship Fighting alcohol harm: The EU's strategy ... VIDEOS Home › Social Europe & Jobs › News Europeans divided over austerity, want alternatives [fr] -A + A Published 02 October ...updated 04 November 2013 7 comments Tags austerity package, crisis response, eurozone crisis, social dimension, social europe As the European Commission is about ...

228

Divided attention in young drivers under the influence of alcohol  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Aim: The present research evaluates driving impairment linked to two crashes factors, divided attention task and alcohol, and determines whether it is higher for novice drivers than for experienced drivers. Method: Novice and experienced drivers participated in three experimental sessions in which blood alcohol concentrations (BACs) were 0.0 g/L, 0.2 g/L and 0.5 g/L. They performed a divided attention task with a main task of car-following task and an additional task of number parity identifi...

Freydier, Chloe?; Berthelon, Catherine; Bastien-toniazzo, Mireille; Gineyt, Guy

2014-01-01

229

Google and the digital divide the bias of online knowledge  

CERN Document Server

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

Segev, Elad

2010-01-01

230

Functionals of Exponential Brownian Motion and Divided Differences  

CERN Document Server

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

Baxter, Brad

2010-01-01

231

Theories of Learning in Educational Development: Relocating the Paradigmatic Divide.  

Science.gov (United States)

Offers a critique of a previous discussion on instructional industrialism in distance education based on instructional design. Topics include the psychological foundations of instructional design, competing paradigms in educational development, behaviorism and cognitivism, theories of learning and the paradigmatic divide, and implications for…

Inglis, Alistair

1996-01-01

232

Bilobular pancreas: another variant of the divided pancreas?  

Directory of Open Access Journals (Sweden)

Full Text Available Background. Pancreas divisum is the most common anomaly of the pancreas. This anomaly has been known as a possible cause of recurrent pancreatitis. Case report. We performed computerized tomography (CT of the abdomen in 5 children in whom a divided pancreas was confirmed using endoscopic cholangiopancreatography. In a girl, who had three episodes of severe acute pancreatitis, a CT examination confirmed a completely divided embryonal dorsal and ventral primordium. We named this variant of the divided pancreas the "bilobular pancreas". Contrary to the remaining 4 children in whom the control of the number and severity of attacks, as well as the control of pancreatic pain were achieved by pharmacotherapeutics and an adequate diet, in the reported patient sphincteroplasty of the papilla duodeni minor resulted in a full control of the disease. Conclusion. The paper discussed the possibility that the variant of the divided pancreas, with anatomically completely separated ventral and dorsal pancreas and their ductal systems, is the key factor that determines the severity of pancreatic disease and an indication for sphincteroplasty of the papilla duodeni minor as the major therapeutic method.

Živanovi? Dragana

2006-01-01

233

Communication in a Divided World: Opportunities and Constraints.  

Science.gov (United States)

Communication systems in a divided world can perpetuate tension and violence or can be instrumental in developing unity. In response to this power, communicators must focus on generating worldwide recognition of interdependence in the shaping and sharing of values. Likewise, a responsible communication policy must stimulate the invention and…

Lasswell, Harold

234

Multiple-Size Divide-and-Conquer Recurrences  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This short note reports a master theorem on tight asymptotic solutions to divide-and-conquer recurrences with more than one recursive term: for example, T(n) = 1/4 T(n/16) + 1/3 T(3n/5) + 4 T(n/100) + 10 T(n/300) + n^2.

Kao, Ming-yang

2001-01-01

235

Digital Divide among Youth: Socio-Cultural Factors and Implications  

Science.gov (United States)

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

Parycek, Peter; Sachs, Michael; Schossbock, Judith

2011-01-01

236

The Digital Divide and Its Impact on Academic Performance  

Science.gov (United States)

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

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

2011-01-01

237

School Change with Technology: Crossing the Digital Divide  

Science.gov (United States)

Closing the digital divide requires much more than buying equipment, it requires increasing the knowledge and skills of teachers using the technology, and access to digital tools in the community. In such a larger system of change, technology can serve as a catalyst for increasing teacher and student learning. The Anaheim City School District…

Riel, Margaret; Schwarz, Jennifer; Hitt, Amy

2002-01-01

238

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

239

A 10-GHz frequency divider using selectively doped heterostructure transistors  

Science.gov (United States)

The first complementary clocked frequency divider using dual gate selectively doped heterostructure transistors (SDHT's) is reported. The circuit employs a master-slave flip-flop design which consists of four direct coupled AND-NOR gates. The nominal gate length and the gate-gate, separation in the dual gate SDHT's are 1 micron. A maximum dividing frequency of 10.1 GHz at 77 K was achieved; at this frequency the circuit dissipated 49.9 mW at 1.67-V bias. This is the highest operating frequency reported for static frequency dividers at any temperature. At room temperature the dividers were operated successfully at frequencies up to 5.5 GHz with a total power dissipation of 34.8 mW at 1.97-V bias. The lowest speed-power product at room temperature was obtained at 5 GHz with 14.9-mW power dissipation at 1.45-V bias.

Hendel, R. H.; Pei, S. S.; Kiehl, R. A.; Tu, C. W.; Feuer, M. D.; Dingle, R.

1984-10-01

240

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

Science.gov (United States)

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

Katsinas, Stephen G.; Moeck, Pat

2002-01-01

 
 
 
 
241

Water  

...Water Facts BookletWater QualityWater PollutionRegulation of DischargesMarine Licensing...effluent dischargestaking action to combat or minimise the effects of pollutionsupporting environmental research.The Drinking Water...

242

Area and Power Optimization of Flexible Multiband Divider  

Directory of Open Access Journals (Sweden)

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

R.Naveenkumar

2013-12-01

243

Beyond artificial intelligence the disappearing human-machine divide  

CERN Document Server

This book is an edited collection of chapters based on the papers presented at the conference “Beyond AI: Artificial Dreams” held in Pilsen in November 2012. The aim of the conference was to question deep-rooted ideas of artificial intelligence and cast critical reflection on methods standing at its foundations.  Artificial Dreams epitomize our controversial quest for non-biological intelligence, and therefore the contributors of this book tried to fully exploit such a controversy in their respective chapters, which resulted in an interdisciplinary dialogue between experts from engineering, natural sciences and humanities.   While pursuing the Artificial Dreams, it has become clear that it is still more and more difficult to draw a clear divide between human and machine. And therefore this book tries to portrait such an image of what lies beyond artificial intelligence: we can see the disappearing human-machine divide, a very important phenomenon of nowadays technological society, the phenomenon which i...

Zackova, Eva; Kelemen, Jozef

2015-01-01

244

A Divide-and-Conquer Strategy for Parsing  

CERN Document Server

In this paper, we propose a novel strategy which is designed to enhance the accuracy of the parser by simplifying complex sentences before parsing. This approach involves the separate parsing of the constituent sub-sentences within a complex sentence. To achieve that, the divide-and-conquer strategy first disambiguates the roles of the link words in the sentence and segments the sentence based on these roles. The separate parse trees of the segmented sub-sentences and the noun phrases within them are then synthesized to form the final parse. To evaluate the effects of this strategy on parsing, we compare the original performance of a dependency parser with the performance when it is enhanced with the divide-and-conquer strategy. When tested on 600 sentences of the IPSM'95 data sets, the enhanced parser saw a considerable error reduction of 21.2% in its accuracy.

Shiuan, P L; Shiuan, Peh Li; Ann, Christopher Ting Hian

1996-01-01

245

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.

246

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.

247

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

2005-09-01

248

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

249

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

2012-01-01

250

Multi-dividing Ontology Algorithm in Auc Criterion Setting (II  

Directory of Open Access Journals (Sweden)

Full Text Available As the extension of Gao et al. (2013, we present the partitioning scheme made of dyadic cubes, the approximation result is thereby obtained concern such partitioning. It is highlighted in this study that AUC criterion multi-dividing ontology algorithm with tree ontology structure and specific split rule has good statistic characteristics, and show that the algorithm under these partitioning schemes are convergent.

Li Yan

2013-01-01

251

Adaptation Procedure for Multi-dividing Ontology Algorithm  

Directory of Open Access Journals (Sweden)

Full Text Available Ontology, as a structured conceptual model of knowledge representation and storage, has widely used in computer science, biomedical and social science. Ontology algorithms even become the core algorithms in information retrieval and thus raise more and more attention. In this study, we propose the adaptation procedure for ontology algorithm in multi-dividing setting. The new technology helps to adapt an unknown parameter and we determine the generalization error bound for such adaptation procedure under certain assumption.

Wei Gao

2013-01-01

252

The 'Digital Divide' Among Financially Disadvantaged Families in Australia  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Mclaren, Jennifer; Zappala, Gianni

2002-01-01

253

Divide-and-Conquer Hartree-Fock Calculations on Proteins  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The ability to perform ab initio electronic structure calculations that scales linearly with the system size is one of the central aims in theoretical chemistry. In this study, the implementation of the divide-and-conquer (DC) algorithm, an algorithm with the potential to aid the achievement of true linear scaling within Hartree-Fock (HF) theory is revisited. Standard HF calculations solve the Roothaan-Hall equations for the whole system; in the DC-HF approach, the diagonalization of the Fock...

He, Xiao; Merz, Kenneth M.

2010-01-01

254

The Road to Sustainability Must Bridge Three Great Divides  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The world's large and rapidly growing human population is exhausting Earth's natural capital at ever-faster rates, and yet appears mostly oblivious to the fact that these resources are limited. This is dangerous for our well-being and perhaps for our survival, as documented by numerous studies over many years. Why are we not moving instead toward sustainable levels of use? We argue here that this disconnection between our knowledge and our actions is largely caused by three "great divides": a...

Aronson, J.; Blignaut, J. N.; Groot, R. S.; Clewell, A.; Lowry Ii, P. P.; Woodworth, P.; Cowling, R. M.; Renison, D.; Farley, J.; Fontaine, C.; Tongway, D.; Levy, S.; Milton, S. J.; Rangel, O.; Debrincat, B.

2010-01-01

255

Sharp van der Corput estimates and minimal divided differences  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Rogers, Keith

2003-01-01

256

Development in Sub-Saharan Africa: Overcoming the Digital Divide  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In an increasingly digitalized world economy, there exists a digital gap between Sub-Saharan Africa and the rest of the world that translates into economic marginalization of the African region. Consequently, the following phases of development are crucial for the region: (1) the phase of massive digitalization during which the digital divide is bridged and (2) the phase of information and knowledge management in which information is systematically converted into knowledge and the latter into...

Oyedokun Agbeja; Salawu, R. O.

2007-01-01

257

Open Access - Ein Wundermittel? Wissenschaft, Gesellschaft, Demokratie, Digital Divide  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Claims for Open Access are mostly underpinned with a)science-related (Open Access accelerates scientific communication) b) financial (Open Access alleviates the serials crisis), c) social (Open Access reduces the Digital Divide), d) democracy-related (Open Access facilitates participation) and socio-political (Open Access levels disparities) arguments. Using sociological concepts and notions this contribution analyses some of the presumptions mentioned. Naiveties as the assu...

Herb, Ulrich

2007-01-01

258

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 h...

Johnson, Doris G.

2005-01-01

259

Water  

Science.gov (United States)

... yellow, you probably need more water. What about bottled water? top Some people like bottled water for its taste or convenience. Some people buy ... your local water. If you're interested in bottled water, keep a few things in mind. There are ...

260

Experimenting Oriya Text Chunking with Divide-Conquer Strategy  

Directory of Open Access Journals (Sweden)

Full Text Available The traditional oriya text chunking approach identifies phrase structure or local word group by using only one model and phrases with the same types of features. Generally oriya language is a free word order language. Free word order languages have relatively unrestricted local word group or phrase structures that make the problem of chunking quite challenging It has been shown that the limitations of using only one model are that: the use of the same types of features is not suitable for all phrases.. In this paper, the divide-conquer approach is proposed and applied in the identification of phrases or local word group. This strategy divides the task of chunking into several sub-tasks according to sensitive features of each phrase and identifies different phrases in parallel. Then, a two-stage decreasing conflict strategy is used to synthesize each sub-task’s answer We argue that we might not need an explicit intermediate POS-tagging step for parsing when a sufficient amount of training material is available and word form information is used for low-frequency words. By applying and testing the approach on the public training and test corpus, the F score for arbitrary phrases identification using divide-conquer strategy achieves 91.3% compared to the previous best F score of 92.18%.

Rakesh Chandra Balabantaray

2010-12-01

 
 
 
 
261

The Patronage of Thirst: Exploring Institutional Fit on a Divided Cyprus  

Directory of Open Access Journals (Sweden)

Full Text Available We explore the links between Cyprus's colonial past, divided present, and current water scarcity. With reference to the concept of fit, we tackle the question of whether we can observe fit in settings where institutions for collective action work differently than we would expect. We perform a secondary analysis of interview materials on Cyprus's water conflicts, extracting arguments for and against different solutions to water scarcity. Two perspectives on fit emerge: "island fit", which supports island-wide institutions; and "patronage fit", which embodies institutions that link Cypriots to their respective patrons Turkey and Greece. The analysis reveals a preference for island-wide institutional arrangements. However, rather than resting on biophysical considerations, such preference is linked to the feeling of unity of the two communities inhabiting Cyprus. We therefore observe institutions that face a trade-off between fitting to social groupings and fitting to biophysical circumstances.

Dimitrios Zikos

2013-06-01

262

Magnetic resonance separation imaging using a divided inversion recovery technique (DIRT).  

Science.gov (United States)

The divided inversion recovery technique is an MRI separation method based on tissue T(1) relaxation differences. When tissue T(1) relaxation times are longer than the time between inversion pulses in a segmented inversion recovery pulse sequence, longitudinal magnetization does not pass through the null point. Prior to additional inversion pulses, longitudinal magnetization may have an opposite polarity. Spatial displacement of tissues in inversion recovery balanced steady-state free-precession imaging has been shown to be due to this magnetization phase change resulting from incomplete magnetization recovery. In this paper, it is shown how this phase change can be used to provide image separation. A pulse sequence parameter, the time between inversion pulses (T180), can be adjusted to provide water-fat or fluid separation. Example water-fat and fluid separation images of the head, heart, and abdomen are presented. The water-fat separation performance was investigated by comparing image intensities in short-axis divided inversion recovery technique images of the heart. Fat, blood, and fluid signal was suppressed to the background noise level. Additionally, the separation performance was not affected by main magnetic field inhomogeneities. PMID:20373401

Goldfarb, James W

2010-04-01

263

Wireless Technologies Bridging the Digital Divide in Education  

Directory of Open Access Journals (Sweden)

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

Gerard Smyth

2006-06-01

264

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

2009-06-01

265

Multidimensional Divide-and-Conquer and Weighted Digital Sums  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 $S_M(n) = \\sum_{t=0}^i t^{\\bar{M}} b_t 2^t$....

Cheung, Y. K.; Flajolet, Philippe; Golin, Mordecai; Lee, C. Y. James

2010-01-01

266

Pump tank divider plate for sump suction sodium pumps  

International Nuclear Information System (INIS)

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

267

Divided Saphenectomy for Varicose Vein in Ambulatory Surgery  

Science.gov (United States)

We performed divided saphenectomy (DS) for varicose vein in ambulatory surgery with minimal incisions. Under tumescent local anesthesia, this procedure ligates all perforators in the thigh, preserving a route of venous drainage, and reduces bruising by ligating all tributaries. Also, DS does not need any special surgical instrument. Subcutaneous inguinal hemorrhage was observed in 4.9% (3/61), mild bruises were observed in 19.7% (12/61), and saphenous nerve neuralgia was 1.6% (1/61). Wound infection, deep venous thrombosis, and edema were not observed. DS is a minimally invasive, simple, and cost-effective procedure. PMID:24995071

2014-01-01

268

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

269

Frequency locking in the injection-locked frequency divider equation  

CERN Document Server

We consider a model for the injection-locked frequency divider, and study analytically the locking onto rational multiples of the driving frequency. We provide explicit formulae for the width of the plateaux appearing in the devil's staircase structure of the lockings, and in particular show that the largest plateaux correspond to even integer values for the ratio of the frequency of the driving signal to the frequency of the output signal. Our results prove the experimental and numerical results available in the literature.

Bartuccelli, Michele V; Gentile, Guido

2008-01-01

270

CLOBAZAM SINGLE OR DIVIDED DOSE AGAINST DIAZEPAM IN ANXIETY NEUROSIS  

Digital Repository Infrastructure Vision for European Research (DRIVER)

One-hundred-and-fifteen patients diagnosed as anxiety neurotics randomly received in a double blind study 20 mg clobazam (Frisium) as a single nightly dose (37 patients) or 10 mg b.d. (38 patients) or diazepam 5 mg b.d. (40 patients) for six weeks, followed by two weeks on placebo. Both the single and divided doses of clobazam were therapeutically equivalent to diazepam. After drug withdrawal, all three treatment groups continued to improve. Patients on clobazam showed better motor performanc...

Channabasavanna, S. M.; Pereira, L. M. Pinto

1986-01-01

271

Water Source Books  

Science.gov (United States)

Online curriculum guides for K-12 with over 324 activities related to wetlands, coastal waters, and water resources. Each grade section (K-2, 3-5, 5-8, and 9-12) is divided into five chapters: Introduction to Water, Drinking Water and Wastewater Treatment, Surface Water Resources, Ground Water Resources, and Wetlands and Coastal Waters.

272

water facts booklet 2011  

...Figures 2011 Contents Introduction River Quality Chemical River Quality Lake Quality Groundwater Quality Marine Bathing Water Quality Marine Water Quality Shellfish Waters Industrial Discharge Quality Water Utility Discharge...points on 2008. Northern Ireland Water Management Water Facts & Figures 2011 67 Water Framework Directive Overall Classification (% river...in order to support fish life. They are divided into two...

273

The Digital Divide: How Wide and How Deep?  

Directory of Open Access Journals (Sweden)

Full Text Available The complexity of the issues that make up the digital divide problem is better understood today. It is no longer sufficient to see it simply as a disparity of access to computer technology. Rather, there is recognition that having meaningful support for using the technology is also an essential ingredient for getting online. The digital divide is a global problem, but even in the technology rich United States the situation is troubling. Recent studies have shown that within the United States, public libraries play a key role in helping the digitally disadvantaged get connected to the Internet and learn how to use it to serve their needs. As more individuals are connected online, those who are not, however, are increasingly in danger for becoming more marginalized within society. Health care professionals need to be aware that they may well be working with individuals who are increasingly outside of the mainstream of the digital revolution and who cannot take advantage of Internet resources that could positively impact their health.

Barbara F. Schloman

2004-05-01

274

Future oscillations around phantom divide in f(R) gravity  

International Nuclear Information System (INIS)

It is known that scalar-tensor theory of gravity admits regular crossing of the phantom divide line wDE = ?1 for dark energy, and existing viable models of present dark energy for its particular case — f(R) gravity — possess one such crossing in the recent past, after the end of the matter dominated stage. It was recently noted that during the future evolution of these models the dark energy equation of state wDE may oscillate with an arbitrary number of phantom divide crossings. In this paper we prove that the number of crossings can be infinite, present an analytical condition for the existence of this effect and investigate it numerically. With the increase of the present mass of the scalaron (a scalar particle appearing in f(R) gravity) beyond the boundary of the appearance of such oscillations, their amplitude is shown to decrease very fast. As a result, the effect quickly becomes small and its beginning is shifted to the remote future

275

Revolutions in Global Networking and Collaborations, and the Digital Divide  

Science.gov (United States)

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

Newman, Harvey

2007-04-01

276

Digital Divide between Teachers and Students in Urban Bangladesh  

DEFF Research Database (Denmark)

Telecom boom since 2000 and ‘Digital Bangladesh’ campaign since late 2008 created significant nationwide hype, resulting rapid increase in the use of digital devices. While studies are being conducted to use the ability of “power users of technology” for reducing digital divide, there is hardly any data available on them in Bangladesh context. A study was conducted to study the digital divide and ICT usage pattern among the urban students and teachers of schools and colleges in Dhaka, the capital of Bangladesh. About 75 students enrolled in probability and statistics course of Independent University, Bangladesh (IUB) in autumn 2009 participated in conducting survey activities. Total 33 academic institutes were south for approval and 11 could be surveyed before the Christmas and annual recess. Responses from 6 other academics institutes were collected from the personal networks of students. A questionnaire was developed based on initial semi-structured interview with randomly selected students from these academic institutions. The 41-question questionnaire was developed to study the usage of computer, internet, mobile and other handheld devices, radio, television and CD/DVD players. A slightly different questionnaire was developed for teachers. 965 students and 185 teachers participated in the survey. Among student respondents 37% were from English Medium and 63% from Bangla medium institutions. From class VI –XII, the survey group represent the secondary and higher secondary education level in Bangladesh. Male respondents were 53% and female 43%, remaining are missing. Responses collected using paper-based questionnaires were put on a learning management system’s (LMS) questionnaire survey module. Irrespective of type of ICT device higher percentage of English medium students ‘own’ and know ‘how to use’ compared to Bangla medium students. Significantly higher percentage of students can use and own desktop, laptop, cellphone, iPOD and MP3 player. While teachers mostly use computers for work (73%), study (45%) and listening music (34%), students use for playing games (63%), listening musing (62%) and study (44%). 69% teachers and 66% students use social networking sites. Top three online activities for students are music (53%), games (47%) and chat (42%), for teachers these are study (55%), chat (40%) and music (33%). Students use more mobile features than teachers. Interestingly 59% teachers and 61% students have more than one SIM card. More than 50% of students and teachers use mobile for listening radio. 55% or more teachers and 67% or more students ‘own’ a desktop. 90% or more teachers and 74% or more students ‘know how to use’ desktop computer. Further study is required to gain insight into digital divide and associated reasons in four different educations systems in Bangladesh.

Khalid, Md. Saifuddin

2011-01-01

277

Matching of Fingerprint Geometry by Advanced Divide and Conquer Technique  

Directory of Open Access Journals (Sweden)

Full Text Available There exist so many techniques for matching two finger print geometry. But this is an algorithm in which divide and conquertechnique is used in an advanced manner. Here at first, the whole image are fragmented into four segments, and finally the four image segment would be chosen from previous different four segments, at first those segments will check the DB Image individually one by one. If the matched value would be greater than the threshold value then neighboring pixel matching would proceed further. After checking the whole image, if we get the result above threshold value then the two fingerprint images would matched. Here the main advantage is that, in the first checking the DB Image would be traversed by four segments, so there exists a better probability to get result above threshold value, because if anyone or any two does not fulfill the criteria then the rest can.

Sanjukta Pal

2013-04-01

278

Divided attention during encoding and retrieval: differential control effects?  

Science.gov (United States)

Previous studies have shown that divided attention (DA) during retrieval has little effect on recall of episodic memories, although DA during encoding has a large detrimental effect. One possible reason for this asymmetry is that stimulus presentation at encoding is under experimenter control, whereas retrieval operations and responses are under participant control. This experiment tested this possibility by presenting paired-associate word lists for learning and recall, either at a fixed 4-s rate or at a rate controlled by the participant. The results showed that the higher recall levels for DA at retrieval than for DA at encoding held under all combinations of experimenter and participant control. The implications of these results for a fuller understanding of encoding and retrieval processes are discussed. PMID:11185794

Craik, F I; Naveh-Benjamin, M; Ishaik, G; Anderson, N D

2000-11-01

279

Divide et Impera?: Western Engagement in the Middle East  

Directory of Open Access Journals (Sweden)

Full Text Available One, important, reason driving recent instability in the Middle East is the influence of Western powers on local actors. In the first half of the 20th century the UK and France held significant sway; during the Cold War the US and USSR were dominant. After the Cold War, the US emerged as the sole, dominating foreign actor in the region. What commonality was shared among all penetrating powers? The strategy of divide and rule was widely deployed. Such a policy was introduced by various means: supporting segments of local populations (especially Arab Christians, polarising local communities against each other and through direct settler activities. This policy was efficient in the short-term but proved destabilising in the long-term. This work takes a critical, birds-eye view at the evolution of engagement in the region and offers insights into the problems produced by such approaches as well as the net benefactors and losers.

Marek ?ejka

2012-12-01

280

How Visibility and Divided Attention Constrain Social Contagion  

CERN Document Server

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

Hodas, Nathan Oken

2012-01-01

 
 
 
 
281

Re-Dividing and Coding of Urbanization Kirkuk City  

Directory of Open Access Journals (Sweden)

Full Text Available  Presented in this paper is a public service data base for Kirkuk city. The data base is based on dividing the town into a number of main districts and coding the zones and neighborhoods in each of the main distracted. This coding would help in constructing a comprehensive indexing system for the available services in the Nations zones of the city. The system may then be utilized in the plans of future expansion of the city in order to reduce discrepancies in the distribution of public services. It has been found that the block system is better and more suitable than other existing methods. It can be implemented easily by governmental establishments that are involved in such services uses geographical information system (GIS. 

Najat K. Omar

2013-05-01

282

Operation of a bidirectional voltage-dividing bremsstrahlung diode  

International Nuclear Information System (INIS)

Operation of a new type of high-power electron diode, the bidirectional voltage-dividing (BVD) diode, has been demonstrated on a 1-MV, 2.5-MA, 20-ns accelerator. This diode consists of a forward- and an inverse-triaxial diode in series. The diode impedance and electron flow pattern agreed reasonably well with particle-in-cell code calculations. The radiation spectrum was measured using two different diagnostics, a differential absorption spectrometer and the time-projection Compton spectrometer. Operating at a voltage of 850--1000 kV, the BVD diode produced a bremsstrahlung spectrum similar to that produced by a standard diode operating at 350--500 kV

283

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

284

Four Sided Domains in Hierarchical Space Dividing Patterns  

Science.gov (United States)

The cracks observed in the glaze of ceramics form networks, which divide the 2D plane into domains. It is shown that, on the average, the number of sides of these domains is four. This contrasts with the usual 2D space divisions observed in Voronoi tessellation or 2D soap froths. In the latter networks, the number of sides of a domain coincides with the number of its neighbors, which, according to Euler’s theorem, has to be six on average. The four sided property observed in cracks is the result of a formation process which can be understood as the successive divisions of domains with no later reorganization. It is generic for all networks having such hierarchical construction rules. We introduce a “geometrical charge,” analogous to Euler’s topological charge, as the difference from four of the number of sides of a domain. It is preserved during the pattern formation of the crack pattern.

Bohn, S.; Douady, S.; Couder, Y.

2005-02-01

285

Proliferating parasites in dividing cells Kimmel's branching model revisited  

CERN Document Server

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

286

Envy up, scorn down: how comparison divides us.  

Science.gov (United States)

Comparison compels people, even as it stresses, depresses, and divides us. Comparison is only natural, but the collateral damage reveals envy upward and scorn downward, and these emotions, arguably, poison people and their relationships. Summaries of several experiments--using questionnaire, psychometric, response-time, electromyographic, and neuroimaging data--illustrate the dynamics of envy up and scorn down, as well as proposing how to mitigate their effects. Initial studies suggest the importance of status. Other data show how scorn down minimizes thought about another's mind; power deactivates mental concepts. Regarding envy up, other studies demonstrate that Schadenfreude (malicious joy) targets envied outgroups. However, counterstereotypic information, empathy, and outcome dependency can mitigate both scorn and envy. PMID:21058760

Fiske, Susan T

2010-11-01

287

Closing the divide: Can the IAEA make a difference?  

International Nuclear Information System (INIS)

Over the last two decades, the world has seen many fundamental changes in the way countries interact. It is seen today in how business is conducted, how fast travel and super-fast communications have opened up the world into almost one huge market and how news of break-through technological innovations appear almost weekly in the media. Yet the world still lives with a vast divide between rich and poor and, from many perspectives, this divide appears to be increasing. The world's development programmes have thus been increasingly scrutinized for their effectiveness and efficiency. The aim is to ensure that the planned benefits reach the end-beneficiaries in a manner that adequately addresses the socio-economic needs of the recipient society. Against this background, the IAEA's relatively small but nevertheless significant programme of technical cooperation has had to reform itself. It has gone from a largely 'technology push' focus to adopting a new 'needs driven' strategy. As the world marks 50 years of the 'Atoms for Peace' initiative, the questions must be asked whether the IAEA's Technical Cooperation Programme (TCP) really can make a difference? Is this programme correctly positioned to be able to meet these very large global challenges? Must it reform itself further to remain meaningful and relevant? What are the determinants for its success within a highly demanding environment? These are the typical questions that have largely shaped the deliberations between largely shaped the deliberations between the IAEA Technical Cooperation Department and its Standing Advisory Group, called SAGTAC, since the group of representatives from Member States was formed in the mid- 1990s

288

Further reflections on the humanistic psychology-positive psychology divide.  

Science.gov (United States)

Replies to comments by Morley (see record 2014-01475-010), Serlin (see record 2014-01475-011), Friedman (see record 2014-01475-012), Churchill and Mruk (see record 2014-01475-013), and Schneider (see record 2014-01475-014) on the current author's original article "The humanistic psychology-positive psychology divide: Contrasts in philosophical foundations" (see record 2013-12501-001). The article contrasting humanistic psychology and positive psychology with respect to their ontological, epistemological, and practical philosophical foundations has generated commentaries from leading proponents of varying perspectives within humanistic psychology. There is a great deal of material within those commentaries with which the current author is in full accord. It is worth noting at the outset that no one appears to be challenging the observations (a) that published exchanges between proponents of humanistic and positive psychology have been marked by tension and ambivalence, albeit with occasional efforts at reconciliation and rapprochement; (b) that proponents of the two perspectives differ with respect to the philosophers they most frequently cite in their writings; or (c) that such citations reflect the philosophical assumptions serving as foundations for the theoretical, research, and counseling/therapeutic endeavors of psychologists in both groups. The principal points of concurrence in the critiques published here are that the current underestimates the extent to which mutually supportive, collaborative work can be accomplished across the philosophical divide and that the recommendations the current author has made has advanced serious potential negative consequences for the field. The current author will address these points here in the reply, although space does not permit him to address other substantive points raised by individual commentators. PMID:24446855

Waterman, Alan S

2014-01-01

289

Spike sorting for polytrodes: a divide and conquer approach  

Science.gov (United States)

In order to determine patterns of neural activity, spike signals recorded by extracellular electrodes have to be clustered (sorted) with the aim of ensuring that each cluster represents all the spikes generated by an individual neuron. Many methods for spike sorting have been proposed but few are easily applicable to recordings from polytrodes which may have 16 or more recording sites. As with tetrodes, these are spaced sufficiently closely that signals from single neurons will usually be recorded on several adjacent sites. Although this offers a better chance of distinguishing neurons with similarly shaped spikes, sorting is difficult in such cases because of the high dimensionality of the space in which the signals must be classified. This report details a method for spike sorting based on a divide and conquer approach. Clusters are initially formed by assigning each event to the channel on which it is largest. Each channel-based cluster is then sub-divided into as many distinct clusters as possible. These are then recombined on the basis of pairwise tests into a final set of clusters. Pairwise tests are also performed to establish how distinct each cluster is from the others. A modified gradient ascent clustering (GAC) algorithm is used to do the clustering. The method can sort spikes with minimal user input in times comparable to real time for recordings lasting up to 45 min. Our results illustrate some of the difficulties inherent in spike sorting, including changes in spike shape over time. We show that some physiologically distinct units may have very similar spike shapes. We show that RMS measures of spike shape similarity are not sensitive enough to discriminate clusters that can otherwise be separated by principal components analysis (PCA). Hence spike sorting based on least-squares matching to templates may be unreliable. Our methods should be applicable to tetrodes and scalable to larger multi-electrode arrays (MEAs). PMID:24574979

Swindale, Nicholas V.; Spacek, Martin A.

2014-01-01

290

On the progress of a water calorimeter project for the verification of radiotherapy dosimetry  

International Nuclear Information System (INIS)

position of the thermistor probes is adjusted and the glass vessel is suspended in the water phantom. The probes are connected to a four-arm AC bridge, where two of the other arms consist of high precision resistors (10k? each), and the third arm includes a decade resistor box for balancing the bridge. The output voltage is measured with a commercial lock-in amplifier. Platinum resistor probes, used to monitor the temperature in the water phantom and in the air volume inside the wooden box, are connected to a Keithley 2001 multimeter equipped with a scanner card. The multimeter, lock-in amplifier, and bridge balancing resistor decade are all connected to a portable PC using a GPIB interface card. This allows each of the devices to be controlled and read out remotely using software developed at NRC. The software allows the bridge to be balanced, the characteristics of the lock-in amplifier to be changed, and controls the acquisition of data according to a pre-selected scheme. It is also used for calculation of the absorbed dose from the measured voltage drop after an irradiation. The sealed water calorimeter is intended to be used in clinical photon, electron, and proton beams to determine experimentally kQ,Qo factors for a variety of ionisation chambers. These factors are fundamental when implementing the new international Code of Practice for radiotherapy dosimetry. The measured values will be compared with the theoretical factors in TRS-398

291

Microstructure and temperature coefficient of resistance of thin cermet resistor films deposited from CrSi2-Cr-SiC targets by S-gun magnetron  

International Nuclear Information System (INIS)

Technological solutions for producing nanoscale cermet resistor films with sheet resistances above 1000 ?/? and low temperature coefficients of resistance (TCR) have been investigated. 2-40 nm thick cermet films were sputter deposited from CrSi2-Cr-SiC targets by a dual cathode dc S-gun magnetron. In addition to studying film resistance versus temperature, the nanofilm structural features and composition were analyzed using scanning electron microscopy, atomic force microscopy, high-resolution transmission electron microscopy, energy-dispersive x-ray spectroscopy, and electron energy loss spectroscopy. This study has revealed that all cermet resistor films deposited at ambient and elevated temperatures were amorphous. The atomic ratio of Si to Cr in these films was about 2 to 1. The film TCR displayed a significant increase when the deposited film thickness was reduced below 2.5 nm. An optimized sputter process consisting of wafer degassing, cermet film deposition at elevated temperature with rf substrate bias, and a double annealing in vacuum, consisting of in situ annealing following the film sputtering and an additional annealing following the exposure of the wafers to air, has been found to be very effective for the film thermal stabilization and for fine tuning the film TCR. Cermet films with thicknesses in the range of 2.5-4 nm deposited using this technique had sheet resistances ranging from 1800 to 1200 ?/? and TCR values from -50 ppm/ deg. C to near zero, respectively. A possible mechanism responsible for the high efficiency of annealing the cermet films in vacuum (after preliminary exposure to air), resulting in resistance stabilization and TCR reduction, is also discussed.

292

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 Liter

Reviewed by Ozlem OZAN,

2009-10-01

293

Informaticiens Sans Frontieres: Helping to bridge the Digital Divide  

CERN Document Server

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

294

Study and achievement of a digital-analog-divider  

International Nuclear Information System (INIS)

This apparatus is designed to give directly, in digital form, the value of the ratio Vt1/V2 two analog voltages. It consists essentially of an analog-digital coder operating by successive weighing; the comparison voltage is made proportional to the divider V2 in the coder. The input dynamics are such that the voltages Vi and V2 are all in the range -50 mV to -5 V. Each of the circuits has an input impedance of about 10 K?. As for the quotient, it is a binary number given in series and parallel form; it is made up of 8 bits, this giving a change of 1/16 to 16 per jump of 1/16 in the zone where the accuracy is highest (V2 ? 800 mV). The time required for a division is, at best, 15 ?sec. During the time of calculation, the voltages V1 and V2 should not vary by more than 1 per cent and 0.5 per cent respectively. The theory of the system and the investigation of a synoptic diagram, the study of the circuits and the actual construction are presented. (author)

295

The Digital Divide in Romania – A Statistical Analysis  

Directory of Open Access Journals (Sweden)

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

Daniela BORISOV

2012-06-01

296

Development in Sub-Saharan Africa: Overcoming the Digital Divide  

Directory of Open Access Journals (Sweden)

Full Text Available In an increasingly digitalized world economy, there exists a digital gap between Sub-Saharan Africa and the rest of the world that translates into economic marginalization of the African region. Consequently, the following phases of development are crucial for the region: (1 the phase of massive digitalization during which the digital divide is bridged and (2 the phase of information and knowledge management in which information is systematically converted into knowledge and the latter into innovative-sustainable development. Information for conversion into knowledge is supplied by the first phase. The second phase is therefore existence dependent on the first. Therefore, the attainment of digitalized state is primary-sine qua non. The envisaged digitalized state can be actualized and consolidated with a combination of: (a curriculum in computer education consisting of computer taxonomy, networking and ICTS in general for secondary and tertiary institutions but also aptly adoptable for informal groups and (b establishment of multipurpose telecentres in rural areas and a diffusion of networks in urban centres. Once a steady digitalized state evidenced by uninterrupted connectivity to the internet is attained, the second phase can be realized. Without steady supply of electricity, however, sustainable development and competitive edge may be hard to come by in a world of fierce competition.

Oyedokun Agbeja

2007-01-01

297

Using environment friendly finely divided materials in brittle matrix composites  

International Nuclear Information System (INIS)

Material engineers the world over are increasingly recommending the use of environment friendly efficient construction materials, which otherwise would have been classed as waste materials for improving the durability of concrete. Pakistan has been blessed by nature with huge natural resources of lime, and fly-ash is also becoming increasingly available with the induction of thermal power generation plants. To introduce the benefits of such concrete modifying materials to the engineering community in our country, an investigation has been carried out on the use of locally available powdered hydrated lime, fly-ash and their combinations in making concretes with a view to evaluate their strength, workability, durability and cost effectiveness. As such there is no documented data of local materials available on the topic in Pakistan. ACI mentions powdered hydrated lime and fly-ash as finely divided admixtures which can be used to improve concrete properties at microstructure level. It is commonly believed by the engineers that the use of such materials is especially desirable for durability purposes. Moreover, lime when added in concrete absorbs CO/sub 2/ from the environment thus making it friendly flexible material. he results of investigation are encouraging especially when the two were used in combination as some weight fraction of cement to make quality and environment friendly concrete. (author)

298

Europe’s competitiveness divide | EurActiv  

... Sustainable Cities Water, Business and Sustainability Towards a recycling society Public Procurement: Buying Green? [Archived] Sustainable Transport Sustainable Development:...new treaty: Towards a multi-speed Union Financial regulation: The EU's agenda Small Business Act: Unlocking SMEs' potential? Markets in Financial Instruments Directive ... hazard in policymaking Air Quality 2013 European Business Summit Nutrition and Child Survival Corporate Governance Cybersecurity Mobile and Broadband e-Skills The Internet: Europe's ... Rural Energy Small Business:driving EU growth? Solar Power Resource efficiency: towards a circular economy Vulnerable Consumers Water Policy ...

299

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 SciELO Mexico | Language: English 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 ser [...] ie de subproblemas de programación cuadrática entera. Los resultados computacionales muestran que la heurística propuesta es una técnica de solución atractiva que permite 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 integ [...] er 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.

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

2012-09-01

300

Full pupil line-scanning confocal microscope for imaging weakly scattering tissues: comparison to divided pupil  

Science.gov (United States)

Confocal reflectance full-pupil and divided-pupil line-scanning microscopes provide optical sectioning and image nuclear detail in skin. Line-scanning with linear detectors is a simpler alternative to point-scanning for imaging weakly scattering epidermis and the oral epithelium. With illumination of 830 nm, a water immersion lens of numerical aperture 0.9 and slit width three times smaller than the diffraction-limited line width, the instrumental full width at half maximum (FWHM) optical sectioning (linespread function) for the full-pupil design is 1.4 +/- 0.07 ?m, which degrades through fullthickness human epidermis to 2.8 +/- 0.78 ?m. The lateral resolution is 0.7+/-0.10 ?m, which degrades to 1.6+/-0.28 ?m through human epidermis. The divided-pupil design demonstrates instrumental optical sectioning of 1.7 ?m, which degrades to 7.6 ?m through human epidermis. The lateral resolution is 1.0 ?m, which degrades to 1.7 ?m. Heavy scattering in the dermis decreases contrast. Images of skin in-vivo show nuclear detail as expected with the predicted and experimentally verified sectioning. However, pixel crosstalk and speckle artifact degrade image quality in strongly scattering and aberrating tissues. The sources of degradation (aberration and scattering) are evaluated for the two design to assess the feasibility of these techniques for in vivo imaging.

Gareau, Daniel S.; Abeytunge, Sanjee; Rajadhyaksha, Milind

2009-02-01

 
 
 
 
301

Dividers for reduction of aerodynamic drag of vehicles with open cavities  

Science.gov (United States)

A drag-reduction concept for vehicles with open cavities includes dividing a cavity into smaller adjacent cavities through installation of one or more vertical dividers. The dividers may extend the full depth of the cavity or only partial depth. In either application, the top of the dividers are typically flush with the top of the bed or cargo bay of the vehicle. The dividers may be of any material, but are strong enough for both wind loads and forces encountered during cargo loading/unloading. For partial depth dividers, a structural angle may be desired to increase strength.

Storms, Bruce L. (Inventor)

2007-01-01

302

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

Science.gov (United States)

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

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

2010-12-01

303

UVA Virtual Lab: Capacitor Water Tank Analogy  

Science.gov (United States)

These pages provide a water model of an electrical circuit. In this case, the gerbil running in its wheel and the bucket pump are the equivalent of a battery. The water represents the flowing electrons. The membrane in the middle is the circuitâs capacitor. The spinning waterwheel represents the resistor which powers the light bulb. This model is part of the UVA Virtual Lab collection. This project is supported by grants from the National Science Foundation, the University of Virginia, IBM, and Discreet Corporation.

Bean, John

2010-12-23

304

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

International Nuclear Information System (INIS)

A realistic antenna module using a poloidal divider for lower hybrid current drive (LHCD) experiment, is modelled and fabricated. In this antenna module test II, three types of poloidal dividers, which split the power in 3, are tested. (author)

305

Water  

...ca/engineering/civil/dr-lalman Interests: anaerobic microbial processes; bioenergy; environmental biotechnology; wastewater treatment; microbial population dynamics; microbial fuel cell; advanced oxidation processes; photocatalysis; process optimization Dr. Luc Lambs EcoLab UMR5245 (CNRS-UPS-INP), 118 route de Narbonne, 31062 Toulouse cedex 09, France Tel. +33 5 61 55 89 21; Fax: +33 5 61 55 89 10 Website: http://www....uk/staff/academic/engineering/tizaouic/ Interests: water and wastewater treatment processes; ozone; photocatalysis; advanced oxidation processes; endocrine disrupting chemicals (EDCs) Dr. Simon Toze CSIRO Land and Water, GPO Box 2583, Brisbane, Qld 4001, Australia Tel. +61 7 3214 2698; Fax: +61 7 3214 2308 Website: http://www.csiro.au/people/Simon.Toze.html Interests: ...

306

Fracture resistance evaluation of RuO2-based thick film resistor material by in situ crack extension observation in a scanning electron microscope  

International Nuclear Information System (INIS)

Parameters for the fracture mechanics of thick film materials are scarce in the literature. One reason is that for many such materials it is very difficult to produce a bulk specimen as required for most standard tests. This paper describes an alternative method for measuring the fracture resistance of a ruthenium dioxide (RuO2)-based thick film resistor material for electronic applications. The method is based on an in situ investigation of crack propagation in the loaded material. The investigated material is printed as a thick film on a substrate of low-temperature-co-fired-ceramic. An initial crack in the film is introduced with a Vickers indenter. The crack is subsequently loaded with a four-point bending equipment in a scanning electron microscope, which allows for in situ crack length measurement. The crack growth measurements reveal that once a certain crack length is achieved the load required to extend the crack becomes independent of the crack length. Beyond this length, the crack propagates in the so-called steady-state region, which is used in the present method to estimate the fracture resistance of the film. Both tensile stresses resulting from bending and tensile residual stresses are taken into account. Although a brittle substrate was used, the crack did not penetrate into the substrate. The measured fracture resistance of 0.69 ± 0.14 MPa?m is found to be realistic for the investigated thick film material with high silicate glass content

307

Fracture resistance evaluation of RuO{sub 2}-based thick film resistor material by in situ crack extension observation in a scanning electron microscope  

Energy Technology Data Exchange (ETDEWEB)

Parameters for the fracture mechanics of thick film materials are scarce in the literature. One reason is that for many such materials it is very difficult to produce a bulk specimen as required for most standard tests. This paper describes an alternative method for measuring the fracture resistance of a ruthenium dioxide (RuO{sub 2})-based thick film resistor material for electronic applications. The method is based on an in situ investigation of crack propagation in the loaded material. The investigated material is printed as a thick film on a substrate of low-temperature-co-fired-ceramic. An initial crack in the film is introduced with a Vickers indenter. The crack is subsequently loaded with a four-point bending equipment in a scanning electron microscope, which allows for in situ crack length measurement. The crack growth measurements reveal that once a certain crack length is achieved the load required to extend the crack becomes independent of the crack length. Beyond this length, the crack propagates in the so-called steady-state region, which is used in the present method to estimate the fracture resistance of the film. Both tensile stresses resulting from bending and tensile residual stresses are taken into account. Although a brittle substrate was used, the crack did not penetrate into the substrate. The measured fracture resistance of 0.69 {+-} 0.14 MPa{radical}m is found to be realistic for the investigated thick film material with high silicate glass content.

Dorsch, Niko Sebastian [Institute of Advanced Ceramics, Hamburg University of Technology, 21071 Hamburg (Germany); Corporate Sector Research and Advance Engineering, Applied Research 1 - Materials, Robert Bosch GmbH, 70049 Stuttgart (Germany)], E-mail: NikoSebastian.Dorsch@de.bosch.com; Peshekhodov, Ilya; Spies, Philipp [Corporate Sector Research and Advance Engineering, Applied Research 1 - Materials, Robert Bosch GmbH, 70049 Stuttgart (Germany); Schneider, Gerold A. [Institute of Advanced Ceramics, Hamburg University of Technology, 21071 Hamburg (Germany)

2008-10-15

308

Natural convection in undivided and partially divided rectangular enclosures  

International Nuclear Information System (INIS)

Heat transfer by natural convection in a two-dimensional rectangular enclosure fitted with partial vertical divisions in investigated experimentally. The horizontal walls of the enclosure are adiabatic while the vertical walls are maintained at different temperatures. The experiments are carried out with water, Prapprox. =3.5, for Rayleigh numbers in the range, 2.3 x 101011, and an aspect ratio, A = H/L = 1/2. The effect of the partial vertical divisions on the fluid flow and temperature fields is investigated by dye-injection flow visualization and by thermocouple probes, respectively. The effect of the partitions on heat transfer across the enclosure is also studied and correlations for the Nusselt number as a function of Ra/sub L/ and partition length are generated for both conducting and non-conducting partition materials. Partial divisions are found to have a significant effect on the heat transfer; especially when the divisions are adiabatic. The results also indicate that the partial divisions may have a stabilizing effect on the laminar-transitional flow on the heated vertical walls of the enclosure

309

Capacitive divider for voltage measurement of diode load on Qiangguang-I Accelerator  

International Nuclear Information System (INIS)

A kind of self-integrating capacitive divider is introduced to measure the diode load voltage on the Qiangguang-I accelerator. The structure of the divider is given first and the static electric field of the divider is simulated by ANSYS. The calculation result shows that no significant effect is induced on the electric field between the anode board and the cathode board, when the divider is located in a small hole on the anode board. By using the square pulse voltage generator and the standard resistance divider the frequency response and the attenuation ratio of the capacitive divider are calibrated. At last the divider-measured voltage of the short-circuit load on the Qiangguang-I accelerator is given. (authors)

310

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

Energy Technology Data Exchange (ETDEWEB)

We introduce an extension of the divide-and-conquer (DC) algorithmic paradigm called divide-conquer-recombine (DCR) to perform large quantum molecular dynamics (QMD) simulations on massively parallel supercomputers, in which interatomic forces are computed quantum mechanically in the framework of density functional theory (DFT). In DCR, the DC phase constructs globally informed, overlapping local-domain solutions, which in the recombine phase are synthesized into a global solution encompassing large spatiotemporal scales. For the DC phase, we design a lean divide-and-conquer (LDC) DFT algorithm, which significantly reduces the prefactor of the O(N) computational cost for N electrons by applying a density-adaptive boundary condition at the peripheries of the DC domains. Our globally scalable and locally efficient solver is based on a hybrid real-reciprocal space approach that combines: (1) a highly scalable real-space multigrid to represent the global charge density; and (2) a numerically efficient plane-wave basis for local electronic wave functions and charge density within each domain. Hybrid space-band decomposition is used to implement the LDC-DFT algorithm on parallel computers. A benchmark test on an IBM Blue Gene/Q computer exhibits an isogranular parallel efficiency of 0.984 on 786?432 cores for a 50.3 × 10{sup 6}-atom SiC system. As a test of production runs, LDC-DFT-based QMD simulation involving 16?661 atoms is performed on the Blue Gene/Q to study on-demand production of hydrogen gas from water using LiAl alloy particles. As an example of the recombine phase, LDC-DFT electronic structures are used as a basis set to describe global photoexcitation dynamics with nonadiabatic QMD (NAQMD) and kinetic Monte Carlo (KMC) methods. The NAQMD simulations are based on the linear response time-dependent density functional theory to describe electronic excited states and a surface-hopping approach to describe transitions between the excited states. A series of techniques are employed for efficiently calculating the long-range exact exchange correction and excited-state forces. The NAQMD trajectories are analyzed to extract the rates of various excitonic processes, which are then used in KMC simulation to study the dynamics of the global exciton flow network. This has allowed the study of large-scale photoexcitation dynamics in 6400-atom amorphous molecular solid, reaching the experimental time scales.

Shimojo, Fuyuki; Hattori, Shinnosuke [Collaboratory for Advanced Computing and Simulations, Department of Physics and Astronomy, Department of Computer Science, and Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089-0242 (United States); Department of Physics, Kumamoto University, Kumamoto 860-8555 (Japan); Kalia, Rajiv K.; Mou, Weiwei; Nakano, Aiichiro; Nomura, Ken-ichi; Rajak, Pankaj; Vashishta, Priya [Collaboratory for Advanced Computing and Simulations, Department of Physics and Astronomy, Department of Computer Science, and Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089-0242 (United States); Kunaseth, Manaschai [Collaboratory for Advanced Computing and Simulations, Department of Physics and Astronomy, Department of Computer Science, and Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089-0242 (United States); National Nanotechnology Center, Pathumthani 12120 (Thailand); Ohmura, Satoshi [Collaboratory for Advanced Computing and Simulations, Department of Physics and Astronomy, Department of Computer Science, and Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089-0242 (United States); Department of Physics, Kumamoto University, Kumamoto 860-8555 (Japan); Department of Physics, Kyoto University, Kyoto 606-8502 (Japan); Shimamura, Kohei [Collaboratory for Advanced Computing and Simulations, Department of Physics and Astronomy, Department of Computer Science, and Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089-0242 (United States); Department of Physics, Kumamoto University, Kumamoto 860-8555 (Japan); Department of Applied Quantum Physics and Nuclear Engineering, Kyushu University, Fukuoka 819-0395 (Japan)

2014-05-14

311

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

Science.gov (United States)

We introduce an extension of the divide-and-conquer (DC) algorithmic paradigm called divide-conquer-recombine (DCR) to perform large quantum molecular dynamics (QMD) simulations on massively parallel supercomputers, in which interatomic forces are computed quantum mechanically in the framework of density functional theory (DFT). In DCR, the DC phase constructs globally informed, overlapping local-domain solutions, which in the recombine phase are synthesized into a global solution encompassing large spatiotemporal scales. For the DC phase, we design a lean divide-and-conquer (LDC) DFT algorithm, which significantly reduces the prefactor of the O(N) computational cost for N electrons by applying a density-adaptive boundary condition at the peripheries of the DC domains. Our globally scalable and locally efficient solver is based on a hybrid real-reciprocal space approach that combines: (1) a highly scalable real-space multigrid to represent the global charge density; and (2) a numerically efficient plane-wave basis for local electronic wave functions and charge density within each domain. Hybrid space-band decomposition is used to implement the LDC-DFT algorithm on parallel computers. A benchmark test on an IBM Blue Gene/Q computer exhibits an isogranular parallel efficiency of 0.984 on 786 432 cores for a 50.3 × 106-atom SiC system. As a test of production runs, LDC-DFT-based QMD simulation involving 16 661 atoms is performed on the Blue Gene/Q to study on-demand production of hydrogen gas from water using LiAl alloy particles. As an example of the recombine phase, LDC-DFT electronic structures are used as a basis set to describe global photoexcitation dynamics with nonadiabatic QMD (NAQMD) and kinetic Monte Carlo (KMC) methods. The NAQMD simulations are based on the linear response time-dependent density functional theory to describe electronic excited states and a surface-hopping approach to describe transitions between the excited states. A series of techniques are employed for efficiently calculating the long-range exact exchange correction and excited-state forces. The NAQMD trajectories are analyzed to extract the rates of various excitonic processes, which are then used in KMC simulation to study the dynamics of the global exciton flow network. This has allowed the study of large-scale photoexcitation dynamics in 6400-atom amorphous molecular solid, reaching the experimental time scales.

Shimojo, Fuyuki; Hattori, Shinnosuke; Kalia, Rajiv K.; Kunaseth, Manaschai; Mou, Weiwei; Nakano, Aiichiro; Nomura, Ken-ichi; Ohmura, Satoshi; Rajak, Pankaj; Shimamura, Kohei; Vashishta, Priya

2014-05-01

312

Digital divide and digital opportunity: Comparison, analysis and strategies for sustainable development in developing nations  

International Nuclear Information System (INIS)

The world is witnessing a new digital economic order which may be quantified by the diffusion of information technology and globalization process. The current information technology gap (digital divide) between developed countries and developing countries is huge. Improvements in information technology (measured by the digital opportunity index) usually open up an opportunity for national/regional growth and development. There is a need for scientific investigation on the digital divide, digital opportunity index and their consequences. This paper presents a critical analysis of existing digital divide and its trends, it also investigates the relationship between the digital divide and the digital opportunity index. A mathematical model based on analysis of the growing digital divide is presented as a possible tool for combating and eradicate the digital divide gap which is only possible if developing and poor nations take advantage of the digital opportunities that can transform them into global competitive partners in digital knowledge economy. (author)

313

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

Directory of Open Access Journals (Sweden)

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

Hsing-I Wang

2011-03-01

314

Zones of silence: A framework beyond the digital divide (originally published in May 2006)  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Potter, Amelia Bryne

2007-01-01

315

Divided Plato  

International Nuclear Information System (INIS)

His experience as nuclear physicist, univerity professor, and research promoter recommend the author as a partner in the discussion on progress. He shows what kind of man a scientist is, which motivations he has, what he can do. He explains how it is possible even today to find simple ways to the unknown, how the new, the unforeseeable comes into being. And he gives stimuli to and examples of the work of scientists, his responsibility and his contribution to the application of knowledge, - for instance in the field of nuclear energy - and of the contributions of science to problems of economy and politics. (orig.)

316

A Quantitative Structure-Property Relationship (QSPR) Study of Aliphatic Alcohols by the Method of Dividing the Molecular Structure into Substructure  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A quantitative structure–property relationship (QSPR) analysis of aliphatic alcohols is presented. Four physicochemical properties were studied: boiling point (BP), n-octanol–water partition coefficient (lg POW), water solubility (lg W) and the chromatographic retention indices (RI) on different polar stationary phases. In order to investigate the quantitative structure–property relationship of aliphatic alcohols, the molecular structure ROH is divided into two parts, R and OH to genera...

2011-01-01

317

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

Science.gov (United States)

...2010-01-01 false Recommended Language for Court Orders Dividing Employee...of Part 838—Recommended Language for Court Orders Dividing Employee...surviving children.” The language may be modified to terminate...children when they reach a stated age. A court order that...

2010-01-01

318

Note on L'Hopital's Rule for the Indeterminate Form "Infinity Divided by Infinity"  

Science.gov (United States)

A theorem with proof is given for L'Hopital's Rule for the indeterminate form "infinity divided by infinity." The theorem takes advantage of the fact that this form is first encountered after the "zero divided by zero" case has been proved. (MN)

Carpenter, James E.

1978-01-01

319

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

Science.gov (United States)

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

Dragulanescu, Nicolae-George

2002-01-01

320

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

Energy Technology Data Exchange (ETDEWEB)

A realistic antenna module using a poloidal divider for lower hybrid current drive (LHCD) experiment, is modelled and fabricated. In this antenna module test II, three types of poloidal dividers, which split the power in 3, are tested. (author). 15 refs.

Maebara, S.; Imai, T.; Seki, M.; Suganuma, K. [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment; Goniche, M.; Bibet, Ph.; Berio, S.; Brossaud, J.; Rey, G.; Tonon, G. [Association Euratom-CEA, Centre d`Etudes de Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee

1997-03-01

 
 
 
 
321

The divided cell algorithm and the inhomogeneous Lagrange and Markoff spectra  

CERN Document Server

The divided cell algorithm was introduced by Delone in 1947 to calculate the inhomogeneous minima of binary quadratic forms and developed further by E. S. Barnes and H. P. F. Swinnerton-Dyer in the 1950s. We show how advances of the past fifty years in both symbolic computation and our understanding of homogeneous spectra can be combined to make divided cells more useful for organizing information about inhomogeneous approximation problems. A crucial part of our analysis relies on work of Jane Pitman, who related the divided cell algorithm to the regular continued fraction algorithm. In particular, the relation to continued fractions allows two divided cells for the same problem to be compared without stepping through the chain of divided cells connecting them.

Bumby, Richard T

2007-01-01

322

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

International Nuclear Information System (INIS)

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

323

A 6-18.5 GHz dynamic frequency divider in 0.25?m SOI CMOS  

Science.gov (United States)

An 18.5 GHz divide-by-four digital frequency divider has been implemented in 0.25?m silicon-on-sapphire CMOS with a power dissipation of 41mW, supply voltage of 2.75V and size of 40×60?m. The design utilises two cascaded divide-by-two 6 transistor dividers. A buffer is used at the output of the first stage to minimise the capacitive load and restore the signal amplitude for the second stage. This significantly increases the operating speed of the circuit. An optimisation design method is proposed for sizing the transistors that uses the amplitude of the output voltage as a metric for the divider speed.

Milner, Leigh

2007-12-01

324

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

International Nuclear Information System (INIS)

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

325

Divided naevus of the penis: two paediatric cases with dermoscopic findings.  

Science.gov (United States)

Divided or kissing naevi are located on adjacent parts of the body that are separated during embryogenesis. Divided naevus of the penis (DNP) is exceedingly rare, with language literature. Divided penile naevi affect the glans penis and inner foreskin, which are anatomical structures believed to have a common embryological origin. We report the clinical, dermoscopic and histopathological findings of two children with DNP. To our knowledge, this is the first report of patients with DNP seen in South America, and the first in which dermoscopic findings are discussed; these included a large globular pattern in one patient, and homogeneous, streaked and globular patterns in the other. PMID:24985200

Mendes, C P; Samorano, L P; Alessi, S S; Nico, M M S

2014-08-01

326

An InGaAs/InP 40 GHz CML static frequency divider  

International Nuclear Information System (INIS)

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

327

Development of a voltage divider and a Rogowski coil for a pulsed x-ray device  

International Nuclear Information System (INIS)

A voltage divider and a Rogowski coil have been developed for measuring currents and voltages of a pulsed X-ray device. The voltage divider is a two stage divider using an aqueous copper sulphate solution, and has been tested up to 300 kV, the highest value expected of the output voltage of the device. Its response-time is measured to be less than 1 ns and the net division ratio, 1 : 1666. The measured response-time of the Rogowski coil is somewhat shorter than 1 ns, and the sensitivity is about 1.04 x 104 A/V. (auth.)

328

Discrete lattice plane broken bond interfacial energy calculations and the use of the dividing surface concept  

Energy Technology Data Exchange (ETDEWEB)

The concept of the dividing surface has been extensively used to define the relationships between thermodynamic quantities at the interface between two phases; it is also useful in calculations of interfacial energy ({gamma}). However, in the original formulation, the two phases are continuum phases, the atomistic nature of the interface was not considered. It is, therefore, useful to examine the use of the dividing surface in the context of atomistic interfacial energy calculations. The case of a planar fcc:hcp interface is considered and the dividing surface positions which are useful in atomistic interfacial energy calculations are stated, one position equates {gamma} to the excess internal energy, the other position allows us to use the Gibbs adsorption equation. An example of a calculation using the convenient dividing surface positions is presented.

Ramanujan, R.V

2003-10-25

329

Discrete lattice plane broken bond interfacial energy calculations and the use of the dividing surface concept  

International Nuclear Information System (INIS)

The concept of the dividing surface has been extensively used to define the relationships between thermodynamic quantities at the interface between two phases; it is also useful in calculations of interfacial energy (?). However, in the original formulation, the two phases are continuum phases, the atomistic nature of the interface was not considered. It is, therefore, useful to examine the use of the dividing surface in the context of atomistic interfacial energy calculations. The case of a planar fcc:hcp interface is considered and the dividing surface positions which are useful in atomistic interfacial energy calculations are stated, one position equates ? to the excess internal energy, the other position allows us to use the Gibbs adsorption equation. An example of a calculation using the convenient dividing surface positions is presented

330

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

2010-04-01

331

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

CERN Multimedia

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

2003-01-01

332

Harmonic-suppressed quadrature-input frequency divider for OFDM systems  

International Nuclear Information System (INIS)

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

333

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

Science.gov (United States)

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

Serres, Nicolas (Epinal, FR)

2010-11-09

334

Unobtrusive monitoring of divided attention in a cognitive health coaching intervention for the elderly.  

Science.gov (United States)

Assessment of cognitive functionality is an important aspect of care for elders. Unfortunately, few tools exist to measure divided attention, the ability to allocate attention to different aspects of tasks. An accurate determination of divided attention would allow inference of generalized cognitive decline, as well as providing a quantifiable indicator of an important component of driving skill. We propose a new method for determining relative divided attention ability through unobtrusive monitoring of computer use. Specifically, we measure performance on a dual-task cognitive computer exercise as part of a health coaching intervention. This metric indicates whether the user has the ability to pay attention to both tasks at once, or is primarily attending to one task at a time (sacrificing optimal performance). The monitoring of divided attention in a home environment is a key component of both the early detection of cognitive problems and for assessing the efficacy of coaching interventions. PMID:21347030

McKanna, James A; Pavel, Misha; Jimison, Holly

2010-01-01

335

Decentralizing Democracy: A Governance Proposal for Post-Conflict Ethnically Divided Countries.  

Science.gov (United States)

The recent experience of nation building in Iraq, and more so in Afghanistan, calls for a deeper analysis of the pre-conditions for establishing an appropriate form of governance in post-conflict, ethnically divided societies. While Afghanistan's democrac...

R. Miske, S. Ganapathiraju

2012-01-01

336

Turning immunological memory into amnesia by depletion of dividing T cells  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Immunological memory, defined as more efficient immune responses on antigen reexposure, can last for decades. The current paradigm is that memory is maintained by antigen-experienced “memory T cells” that can be long-lived quiescent or dividing. The contribution of T cell division to memory maintenance is poorly known and has important clinical implications. In this study, we directly addressed the role of dividing T cells in immunological memory maintenance by evaluating the consequences...

Bellier, Bertrand; Thomas-vaslin, Ve?ronique; Saron, Marie-franc?oise; Klatzmann, David

2003-01-01

337

Statistical and numerical methods to improve the transient divided bar method  

DEFF Research Database (Denmark)

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

Bording, Thue Sylvester; Balling, N.

338

Exploring the Future of the Digital Divide through Ethnographic Futures Research  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Mitchell, Matthew

2002-01-01

339

Online but still divided: Inequality in private internet use in Germany  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this analysis, we compare the determinants of the first-level and the second-level digital divide for private internet use in Germany. Our work offers three important innovations. First, we use the exact weekly duration of internet use to explain inequalities in internet intensity, explicitly controlling for non-users. Secondly, we use the frequencies of five different internet applications to further investigate the determinants of the second-level digital divide. Thirdly, we estimate sel...

Coneus, Katja; Schleife, Katrin

2010-01-01

340

The Effect of Digital Divide on Information Accessibility among Undergraduate Students of Ahmadu Bello University, Zaria  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The study was undertaken to evaluate the effect of digital divide on information accessibility among undergraduate students of Ahmadu Bello University, Zaria. To accomplish this study, survey research was employed in gathering information from the sample population. Face to face method otherwise known as on the spot method of administration of questionnaire was adopted. The questionnaire was divided into two sections. Bio-data & the respondent’s, at the course of this study, it was discover...

Achebe, N. E. E.; Lucky, A. T.

2013-01-01

 
 
 
 
341

Combined method for simultaneously dewatering and reconstituting finely divided carbonaceous material  

Science.gov (United States)

A finely-divided carbonaceous material is dewatered and reconstituted in a combined process by adding a binding agent directly into slurry of finely divided material and dewatering the material to form a cake or consolidated piece which can be hardened by drying at ambient or elevated temperatures. Alternatively, the binder often in the form of a crusting agent is sprayed onto the surface of a moist cake prior to curing.

Wen, Wu-Wey (Murrysville, PA); Deurbrouck, Albert W. (Pittsburgh, PA)

1990-01-01

342

Combined uranous nitrate production consisting of undivided electrolytic cell and divided electrolytic cell (Electrolysis ? Electrolytic cell)  

International Nuclear Information System (INIS)

The electrochemical reduction of uranyl nitrate is a green, mild way to make uranous ions. Undivided electrolyzers whose maintenance is less but their conversion ratio and current efficiency are low, have been chosen. However, at the beginning of undivided electrolysis, high current efficiency can also be maintained. Divided electrolyzers' conversion ratio and current efficiency is much higher because the re-oxidation of uranous on anode is avoided, but their maintenance costs are more, because in radioactive environment the membrane has to be changed after several operations. In this paper, a combined method of uranous production is proposed which consists of 2 stages: undivided electrolysis (early stage) and divided electrolysis (late stage) to benefit from the advantages of both electrolysis modes. The performance of the combined method was tested. The results show that in combined mode, after 200 min long electrolysis (80 min undivided electrolysis and 120 min divided electrolysis), U(IV) yield can achieve 92.3% (500 ml feed, U 199 g/l, 72 cm2 cathode, 120 mA/cm2). Compared with divided mode, about 1/3 working time in divided electrolyzer is reduced to achieve the same U(IV) yield. If 120 min long undivided electrolysis was taken, more than 1/2 working time can be reduced in divided electrolyzer, which means that about half of the maintenance cost can also be reduced. (authors)

343

Combined uranous nitrate production consisting of undivided electrolytic cell and divided electrolytic cell (Electrolysis ? Electrolytic cell)  

Energy Technology Data Exchange (ETDEWEB)

The electrochemical reduction of uranyl nitrate is a green, mild way to make uranous ions. Undivided electrolyzers whose maintenance is less but their conversion ratio and current efficiency are low, have been chosen. However, at the beginning of undivided electrolysis, high current efficiency can also be maintained. Divided electrolyzers' conversion ratio and current efficiency is much higher because the re-oxidation of uranous on anode is avoided, but their maintenance costs are more, because in radioactive environment the membrane has to be changed after several operations. In this paper, a combined method of uranous production is proposed which consists of 2 stages: undivided electrolysis (early stage) and divided electrolysis (late stage) to benefit from the advantages of both electrolysis modes. The performance of the combined method was tested. The results show that in combined mode, after 200 min long electrolysis (80 min undivided electrolysis and 120 min divided electrolysis), U(IV) yield can achieve 92.3% (500 ml feed, U 199 g/l, 72 cm{sup 2} cathode, 120 mA/cm{sup 2}). Compared with divided mode, about 1/3 working time in divided electrolyzer is reduced to achieve the same U(IV) yield. If 120 min long undivided electrolysis was taken, more than 1/2 working time can be reduced in divided electrolyzer, which means that about half of the maintenance cost can also be reduced. (authors)

Yuan, Zhongwei; Yan, Taihong; Zheng, Weifang; Li, Xiaodong; Yang, Hui; Xian, Liang [China Institute of Atomic Energy, P.O.Box 275-26, Beijing 102413 (China)

2013-07-01

344

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

Science.gov (United States)

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

Massachusetts State Water Resources Authority, Boston.

345

Turning immunological memory into amnesia by depletion of dividing T cells.  

Science.gov (United States)

Immunological memory, defined as more efficient immune responses on antigen reexposure, can last for decades. The current paradigm is that memory is maintained by antigen-experienced "memory T cells" that can be long-lived quiescent or dividing. The contribution of T cell division to memory maintenance is poorly known and has important clinical implications. In this study, we directly addressed the role of dividing T cells in immunological memory maintenance by evaluating the consequences of their elimination. The specific ablation of dividing T cells was obtained by administration of ganciclovir to immune mice expressing the herpes simplex type 1 thymidine kinase suicide gene in T cells. We show that depletion of dividing T cells for 5 or 2 weeks suffices to abolish in vitro and in vivo memory responses against the male H-Y transplantation alloantigen or against lymphocytic choriomeningitis virus antigens, respectively. Similar results were obtained after the nonspecific elimination of all dividing cells by using hydroxyurea, a cytostatic toxic agent commonly used for cancer chemotherapy. This immune amnesia occurred in otherwise immunocompetent mice and despite the persistence of functional quiescent T cells displaying a "memory" phenotype. Thus, division of antigen-experienced T cells is an absolute requirement for immunological memory maintenance and the current concept of memory T cells is challenged. PMID:14634206

Bellier, Bertrand; Thomas-Vaslin, Véronique; Saron, Marie-Françoise; Klatzmann, David

2003-12-01

346

Dissociation between two types of skill learning tasks: the differential effect of divided attention.  

Science.gov (United States)

The proposed distinction between perceptual and conceptual skill-learning tasks was tested. Eighty participants were administered a cued recall task and two priming tasks, one perceptual (partial word identification) and one conceptual (category production). Two skill-learning task were administered as well, one putative perceptual (mirror reading) and the other putative conceptual (Tower of Hanoi puzzle). Each task was performed by half of the participants under a full attention condition, and by the other half under a divided attention condition. Consistent with previous reports in the literature, divided attention did not interfere with the perceptual priming task, but did interfere with the conceptual priming and cued recall tasks. Dissociation was also observed for the skill-learning tasks. Divided attention did not affect either baseline performance or learning rate on the mirror reading task. However, on the Tower of Hanoi puzzle, divided attention did interfere with baseline performance, but contrary to prediction it did not interfere with learning rate. The differential effect of divided attention on the baseline performance in these two tasks was interpreted as supporting the distinction between conceptual and perceptual skill-learning tasks. PMID:15370387

Vakil, Eli; Hoffman, Yaakov

2004-08-01

347

ROMANIA’S DIGITAL DIVIDE AND THE FAILURES OF E-GOVERNMENT  

Directory of Open Access Journals (Sweden)

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

Sorin Dan ?ANDOR

2006-02-01

348

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

349

Kinematic Identification of Parallel Mechanisms by a Divide and Conquer Strategy  

DEFF Research Database (Denmark)

This paper presents a Divide and Conquer strategy to estimate the kinematic parameters of parallel symmetrical mechanisms. The Divide and Conquer kinematic identification is designed and performed independently for each leg of the mechanism. The estimation of the kinematic parameters is performed using the inverse calibration method. The identification poses are selected optimizing the observability of the kinematic parameters from a Jacobian identification matrix. With respect to traditional identification methods the main advantages of the proposed Divide and Conquer kinematic identification strategy are: (i) reduction of the kinematic identification computational costs, (ii) improvement of the numerical efficiency of the kinematic identification algorithm and, (iii) improvement of the kinematic identification results. The contributions of the paper are: (i) The formalization of the inverse calibration method as the Divide and Conquer strategy for the kinematic identification of parallel symmetrical mechanisms and, (ii) a new kinematic identification protocol based on the Divide and Conquer strategy. As an application of the proposed kinematic identification protocol the identification of a planar 5R symmetrical mechanism is simulated. The performance of the calibrated mechanism is evaluated by updating the kinematic model with the estimated parameters and developing simulations.

Durango, Sebastian; Restrepo-Giraldo, John Dairo

2010-01-01

350

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

Science.gov (United States)

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

Shimojo, F.; Ohmura, S.; Nakano, A.; Kalia, R. K.; Vashishta, P.

2011-05-01

351

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

Directory of Open Access Journals (Sweden)

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

Vashishta P.

2011-05-01

352

Accuracy of optical frequency comb generators and optical frequency interval divider chains.  

Science.gov (United States)

We compared two methods for measuring large optical frequency differences: an optical frequency comb generator, which creates a large number of sidebands from a single-mode laser through electro-optic modulation, and an optical frequency interval divider chain, which divides a frequency gap successively by two until it becomes accessible to a radio-frequency counter. By locking two diode lasers to two modulation sidebands of a comb generator, ~1 THz apart, and measuring this interval with a chain of four phase-locked interval dividers, we demonstrate for the first time to our knowledge the accuracy of both techniques within an experimental limit of 6.8 x 10(-15). PMID:18091794

Udem, T; Reichert, J; Hänsch, T W; Kourogi, M

1998-09-01

353

10-30 GHz monolithic GaAs travelling-wave divider/combiner  

Science.gov (United States)

A four-way monolithic GaAs traveling-wave power divider/combiner has been designed, fabricated and evaluated. With a design center frequency of 20 GHz, a bandwidth of from 10 GHz to 30 GHz has been measured. The insertion loss per dividing or combining action is less than 0.5 dB, with isolation between ports no worse than 20 dB. The input/output VSWRs are better than 2:1 across the same band. This divider/combiner can readily be used with monolithic GaAs power FET amplifiers to produce a several-fold increase in output powers over the 10 to 30 GHz frequency range.

Tserng, H. Q.; Saunier, P.

1985-01-01

354

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

International Nuclear Information System (INIS)

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

355

Bilateral hand performance with divided attention after a cerebral vascular accident.  

Science.gov (United States)

A divided attention task was used with 10 left or right cerebral vascular accident (CVA) subjects who had return of functional movement in the affected extremities. The primary task was one subtest of the Jebson Hand Function Test. The secondary task was a foot press to a series of auditory cues. Four measurements were obtained for each subject at intervals of 1 month, 2 months, and 3 months after the stroke. Comparison scores on this procedure were also obtained on 5 normal subjects. The results indicated that dividing attention in the CVA subjects significantly decreased the performance on the primary task. The performance with the affected limb improved over the 3-month time period and reached a level of performance that was not significantly different from that of the unaffected limb for either the undivided or divided attention task. Implications for occupational therapy environments and consideration of attention limitations are discussed. PMID:3565531

Dittmar, C M; Gliner, J A

1987-02-01

356

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

2007-01-01

357

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

International Nuclear Information System (INIS)

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

358

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

Science.gov (United States)

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. PMID:21847227

Quinlan, Franklyn; Fortier, Tara M; Kirchner, Matthew S; Taylor, Jennifer A; Thorpe, Michael J; Lemke, Nathan; Ludlow, Andrew D; Jiang, Yanyi; Diddams, Scott A

2011-08-15

359

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

CERN Document Server

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

360

Hollande, Merkel bid to bridge divide over eurozone’s future | EurActiv  

...Hollande, Merkel bid to bridge divide over eurozone’s future | EurActiv euro-finance,future-eu,priorities,Angela Merkel,Economic and Monetary union,economic governance,euro ... VIDEOS Home › Future EU › News Hollande, Merkel bid to bridge divide over eurozone’s future [fr] -A + A Published 30 ...May 2013, updated 03 June 2013 Tags Angela Merkel, Economic and Monetary union, economic governance, euro zone crisis, Francois Hollande German Chancellor Angela ... Merkel was due to Paris on Thursday (30 May) for talks with President François Hollande aimed at coming up with new ideas ...

 
 
 
 
361

Effect of alcohol and divided attention task on simulated driving performance of young drivers  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The aim of this study is to evaluate driving impairment linked to divided attention task and alcohol and determinate if it is higher for novice drivers compared to more experienced drivers. Sixteen novice drivers and sixteen experienced drivers participated in three experimental sessions corresponding to blood alcohol concentration [BAC] of 0.0 g/L, 0.2 g/L and 0.5 g/L. They performed a divided attention task [car-following task combined with a number parity identification task], and their re...

Freydier, Chloe?; Berthelon, Catherine; Bastien-toniazzo, Mireille; Gineyt, Guy

2013-01-01

362

An Improved Algorithm for the Technology Mapping Re-connection Based on Divide Set  

Directory of Open Access Journals (Sweden)

Full Text Available This paper proposes an improved algorithm for the technology mapping re-connection based on divided set. Through establishing a two-dimensional plot, the algorithm prevents consolidated operating constraints from being affected by divide set computing, and designs a heuristic algorithm to optimize area and delay. Therefore, an improved algorithm for the technology mapping re-connection is proposed. Experimental results show the algorithm can greatly increase the capability of re-connection compared with the available local and global optimization method, in such a case that the running times required are the same.

Hai Zhu

2013-06-01

363

Blind Europeans divided by living standards, united by obstacles | EurActiv  

...Blind Europeans divided by living standards, united by obstacles | EurActiv specialreport-eye-on-active-ageing,health,Active ageing,eyesight,Technology EU news & policy debates- across ...Halting the Decline Plastics and PVC Energising Tomorrow's World Agriculture Resource Efficiency Eye on Active Ageing SME's Access to Finance Free Trade for Growth ... Blog | Democracy must prevail Blog | Ukraine 2014: Not Another US-backed Color Revolution Blog | Emily O’Reilly à la commission LIBE Blog | ... VIDEOS Home › Eye on Active Ageing › News Blind Europeans divided by living standards, united by obstacles -A + A Published ...

364

Les Diviseurs Analogiques de Frequence Micro-Ondes: Modelisation, Conception et Realisation (Microwave Analog Frequency Dividers: Design, Modeling and Realization).  

Science.gov (United States)

The design and modeling of microwave analog frequency dividers are investigated. Frequency domain and harmonic balance simulations of the transistor behavior, to permit self-biasing to be understood, are carried out. An approach to analog frequency divide...

H. Amine

1993-01-01

365

5 CFR Appendix A to Subpart J of... - Guidelines for Interpreting State Court Orders Dividing Civil Service Retirement Benefits  

Science.gov (United States)

...interpreted as dividing CSRS benefits. Terms such as “CSRS,” “United States... 2. OPM will not divide disability retirement benefits when such a division would...expressly directs division of “disability” benefits. B. Orders that do...

2010-01-01

366

The Water Sourcebooks  

Science.gov (United States)

The Water Sourcebooks from the U.S. Environmental Protection Agency contain 324 activities for grades K-12 divided into four sections: K-2, 3-5, 5-8, and 9-12. Each section is divided into five chapters: Introduction to Water, Drinking Water and Wastewater Treatment, Surface Water Resources, Ground Water Resources, and Wetlands and Coastal Waters. This environmental education program explains the water management cycle using a balanced approach showing how it affects all aspects of the environment. All activities contain hands-on investigations, fact sheets, reference materials, and a glossary of terms. Activities are organized by objectives, materials needed, background information, advance preparation, procedures, and resources. All parts of the program may be printed and copied.

367

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Adel Ben Youssef; Ludovic Ragni

2008-01-01

368

Crossing the Divide: Helen Keller and Yvonne Pitrois Dialogue on Diversity  

Science.gov (United States)

How do those who are living with a difference most effectively cross the cultural divide and explain themselves to mainstream society? This is a central question raised by Yvonne Pitrois in her biography of Helen Keller, titled "Une nuit rayonnante: Helen Keller" [A Shining Night: Helen Keller]. Helen Keller responded to Pitrois' book in a…

Hartig, Rachel

2007-01-01

369

A new concept for spatially divided Deep Reactive Ion Etching with ALD-based passivation  

International Nuclear Information System (INIS)

Conventional Deep Reactive Ion Etching (DRIE) is a plasma etch process with alternating half-cycles of 1) Si-etching with SF6 to form gaseous SiFx etch products, and 2) passivation with C4F8 that polymerizes as a protecting fluorocarbon deposit on the sidewalls and bottom of the etched features. In this work we report on a novel alternative and disruptive technology concept of Spatially-divided Deep Reactive Ion Etching, S-DRIE, where the process is converted from the time-divided into the spatially divided regime. The spatial division can be accomplished by inert gas bearing 'curtains' of heights down to ?20 ?m. These curtains confine the reactive gases to individual (often linear) injection slots constructed in a gas injector head. By horizontally moving the substrate back and forth under the head one can realize the alternate exposures to the overall cycle. A second improvement in the spatially divided approach is the replacement of the CVD-based C4F8 passivation steps by ALD-based oxide (e.g. SiO2) deposition cycles. The method can have industrial potential in cost-effective creation of advanced 3D interconnects (TSVs), MEMS manufacturing and advanced patterning, e.g., in nanoscale transistor line edge roughness using Atomic Layer Etching.

370

Military-Entrepreneur Relations in China since 1979: From Political Divide to Social Reconciliation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

There have been substantial changes in the relationship between the PLA and the emerging private entrepreneurs since China’s reform and opening-up. As a consequence, these relations have shifted from the old model of political divide to a new model of social reconciliatio...

Yongchang Wang

2009-01-01

371

On Solutions of Holonomic Divided-Difference Equations on Nonuniform Lattices  

Directory of Open Access Journals (Sweden)

Full Text Available The main aim of this paper is the development of suitable bases that enable the direct series representation of orthogonal polynomial systems on nonuniform lattices (quadratic lattices of a discrete or a q-discrete variable. We present two bases of this type, the first of which allows one to write solutions of arbitrary divided-difference equations in terms of series representations, extending results given by Sprenger for the q-case. Furthermore, it enables the representation of the Stieltjes function, which has already been used to prove the equivalence between the Pearson equation for a given linear functional and the Riccati equation for the formal Stieltjes function. If the Askey-Wilson polynomials are written in terms of this basis, however, the coefficients turn out to be not q-hypergeometric. Therefore, we present a second basis, which shares several relevant properties with the first one. This basis enables one to generate the defining representation of the Askey-Wilson polynomials directly from their divided-difference equation. For this purpose, the divided-difference equation must be rewritten in terms of suitable divided-difference operators developed in previous work by the first author.

Salifou Mboutngam

2013-07-01

372

Bridging the Digital Divide: Changing the Technological Landscape of Inner-City Catholic Schools  

Science.gov (United States)

This article presents an evaluation of the Bridging the Digital Divide Program, an intervention in five inner-city Chicago Catholic schools during one school year conducted by a local university. The interventions included (a) instillation of technology and (b) professional technology skill development for in-service teachers. The analysis…

Gibbs, Michael G.; Dosen, Anthony J.; Guerrero, Rosalie B.

2009-01-01

373

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

374

A prototype splitter apparatus for dividing large catches of small fish  

Science.gov (United States)

Due to financial and time constraints, it is often necessary in fisheries studies to divide large samples of fish and estimate total catch from the subsample. The subsampling procedure may involve potential human biases or may be difficult to perform in rough conditions. We present a prototype gravity-fed splitter apparatus for dividing large samples of small fish (30–100 mm TL). The apparatus features a tapered hopper with a sliding and removable shutter. The apparatus provides a comparatively stable platform for objectively obtaining subsamples, and it can be modified to accommodate different sizes of fish and different sample volumes. The apparatus is easy to build, inexpensive, and convenient to use in the field. To illustrate the performance of the apparatus, we divided three samples (total N = 2,000 fish) composed of four fish species. Our results indicated no significant bias in estimating either the number or proportion of each species from the subsample. Use of this apparatus or a similar apparatus can help to standardize subsampling procedures in large surveys of fish. The apparatus could be used for other applications that require dividing a large amount of material into one or more smaller subsamples.

Stapanian, Martin A.; Edwards, William H.

2012-01-01

375

Building Bridging Social Capital in a Divided Society: The Role of Participatory Citizenship Education  

Science.gov (United States)

Participatory citizenship education has been highlighted as a strategy to promote social cohesion in divided societies whereby collaborations with non-governmental organizations (NGOs) and inter-school links have been proposed as tools to improve social networks between schools and communities. This article explores the role and meaning of…

McMurray, Alan; Niens, Ulrike

2012-01-01

376

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

Directory of Open Access Journals (Sweden)

Full Text Available This article proposes to prove economically the existence of a second level digital divide in Morocco. We have well designed and administered a questionnaire to approach 1030 persons living in the two largest cities of the Kingdom: Rabat and Casablanca. It seemed to us at the appropriate time to get down working in these big cities where normally there should not be any digital divide, at least the one of first degree, in order to detect inequalities in the use of the Internet. By the present field work we seek to determine far beyond Internet access, a kind of persons being behind the second degree digital divide. Our results lead us to say that the use of the Internet in the cities is influenced by socioeconomic position and the living conditions of individuals. The second degree digital divide is omnipresent. These results are enough to put into perspective the effectiveness of policies to ensure a wide coverage of the country by the ICT expected to create the added value and improve the living standards and social wellbeing of citizens.

Samira Oukarfi

2013-02-01

377

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

Science.gov (United States)

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

Unnever, James D.; Cullen, Francis T.

2007-01-01

378

Closing the Digital Divide: Education Telecommunications Systems and Possibilities in Western Australia  

Science.gov (United States)

The research reported in this paper considers the current telecommunications network for the three education systems of state, independent and catholic schools in Western Australia as well as drawing on the personal experiences of teachers in these systems as the government attempts to close the digital divide with its Networking the Nation…

Trinidad, Sue

2007-01-01

379

A new concept for spatially divided Deep Reactive Ion Etching with ALD-based passivation  

Science.gov (United States)

Conventional Deep Reactive Ion Etching (DRIE) is a plasma etch process with alternating half-cycles of 1) Si-etching with SF6 to form gaseous SiFx etch products, and 2) passivation with C4F8 that polymerizes as a protecting fluorocarbon deposit on the sidewalls and bottom of the etched features. In this work we report on a novel alternative and disruptive technology concept of Spatially-divided Deep Reactive Ion Etching, S-DRIE, where the process is converted from the time-divided into the spatially divided regime. The spatial division can be accomplished by inert gas bearing 'curtains' of heights down to ~20 ?m. These curtains confine the reactive gases to individual (often linear) injection slots constructed in a gas injector head. By horizontally moving the substrate back and forth under the head one can realize the alternate exposures to the overall cycle. A second improvement in the spatially divided approach is the replacement of the CVD-based C4F8 passivation steps by ALD-based oxide (e.g. SiO2) deposition cycles. The method can have industrial potential in cost-effective creation of advanced 3D interconnects (TSVs), MEMS manufacturing and advanced patterning, e.g., in nanoscale transistor line edge roughness using Atomic Layer Etching.

Roozeboom, F.; Kniknie, B.; Lankhorst, A. M.; Winands, G.; Knaapen, R.; Smets, M.; Poodt, P.; Dingemans, G.; Keuning, W.; Kessels, W. M. M.

2012-12-01

380

Choice Issue Opens Rift in Missouri: Tax-Credit Scholarships Divide Black Caucus  

Science.gov (United States)

The debate over a school choice bill in the Missouri legislature has opened a bitter rift among some of the state's top Black elected officials and reflects a larger divide among African-Americans over school choice nationwide. The bill, which is similar to programs that are growing in popularity in other states, would provide tax credits for…

Viadero, Debra

2006-01-01

 
 
 
 
381

Soul and Role Dialogues in Higher Education: Healing the Divided Self  

Science.gov (United States)

A group of faculty and staff gather in a conference room in the student union to share experiences with the soul-role divide at work and in the classroom. The meeting begins with a reminder of the group's conversational norms that invite deep reflection and a safe place for the soul. The purpose of the meeting is exploring the deep heartfelt and…

Michalec, Paul; Brower, Gary

2012-01-01

382

Self-calibration of divided circles on the basis of a prime factor algorithm  

International Nuclear Information System (INIS)

A new method for the self-calibration of divided circles is presented which is based on a known prime factor algorithm for the discrete Fourier transform (DFT). The method, called prime factor division (PFD) calibration, is of interest in angle metrology specially for self-calibrating angle encoders, and generally for a significant shortening of the cross-calibration between two divided circles. It requires that the circular division number N can be expressed as a product N = R × S, whereby the factors R and S are relatively prime integer numbers. For the self-calibration of a divided circle, N difference measurements between R angle positions in a regular distribution and one reference angle position determined by S are evaluated by a two-dimensional DFT, yielding the N absolute division errors. The factor R is preferably chosen small, down to a minimum of R = 2, whereas the factor S may be as large as appropriate for the division number N of interest. In the case of a cross-calibration between two divided circles, the PFD method reduces the number of measurements necessary from N2 to (R + 1) × N. Experimental results are demonstrated for the calibrations of an optical polygon with 24 faces (prime factor product 3 × 8) and a gearwheel with 44 teeth (prime factor product 4 × 11)

383

Low-power wide-locking-range injection-locked frequency divider for OFDM UWB systems  

International Nuclear Information System (INIS)

This paper describes a divide-by-two injection-locked frequency divider (ILFD) for frequency synthesizers as used in multiband orthogonal frequency division multiplexing (OFDM) ultra-wideband (UWB) systems. By means of dual-injection technique and other conventional tuning techniques, such as DCCA and varactor tuning, the divider demonstrates a wide locking range while consuming much less power. The chip was fabricated in the Jazz 0.18 ?m RF CMOS process. The measurement results show that the divider achieves a locking range of 4.85 GHz (6.23 to 11.08 GHz) at an input power of 8 dBm. The core circuit without the test buffer consumes only 3.7 mA from a 1.8 V power supply and has a die area of 0.38 x 0.28 mm2. The wide locking range combined with low power consumption makes the ILFD suitable for its application in UWB systems.

384

Low-power wide-locking-range injection-locked frequency divider for OFDM UWB systems  

Energy Technology Data Exchange (ETDEWEB)

This paper describes a divide-by-two injection-locked frequency divider (ILFD) for frequency synthesizers as used in multiband orthogonal frequency division multiplexing (OFDM) ultra-wideband (UWB) systems. By means of dual-injection technique and other conventional tuning techniques, such as DCCA and varactor tuning, the divider demonstrates a wide locking range while consuming much less power. The chip was fabricated in the Jazz 0.18 mum RF CMOS process. The measurement results show that the divider achieves a locking range of 4.85 GHz (6.23 to 11.08 GHz) at an input power of 8 dBm. The core circuit without the test buffer consumes only 3.7 mA from a 1.8 V power supply and has a die area of 0.38 x 0.28 mm{sup 2}. The wide locking range combined with low power consumption makes the ILFD suitable for its application in UWB systems.

Yin Jiangwei; Li Ning; Zheng Renliang; Li Wei; Ren Junyan, E-mail: lining@fudan.edu.c [State Key Laboratory of ASIC and System, Fudan University, Shanghai 201203 (China)

2009-05-01

385

Two Aspects of the Rural-Urban Divide and Educational Stratification in China: A Trajectory Analysis  

Science.gov (United States)

Contextualized in China's social change of the past half-century, this article conceptualizes the two aspects of China's rural-urban divide in educational inequality--the household registration system ("hukou") assigns people to a hierarchy, and the rural-urban schooling system institutionalizes unequal resource distribution…

Hao, Lingxin; Hu, Alfred; Lo, Jamie

2014-01-01

386

Public attitudes on the gay marriage debate are divided along party lines  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The Minister for Women and Equalities, Maria Miller, made a statement to Parliament yesterday about gay marriage. Following this Ben Clements analyses the attitudes towards gay marriage among party supporters and finds that party affiliation is a clear dividing line in public opinion on this issue.

Clements, Ben

2012-01-01

387

Bridging the Theory/Practice Divide in Education: Seeing Reading as Research and Research as Reading  

Science.gov (United States)

For decades there has been a divide between educational research and practice. Sometimes the blame is placed on teachers for not following research-based strategies or not being trained well enough to read the literature. Just as frequently the blame is placed on researchers for not (a) studying topics important to teachers, (b) writing them so…

Boody, Robert M.

2010-01-01

388

Resultados de la técnica de facoemulsificación "Divide y Vencerás" en la cirugía de catarata / Results of the "Divide and Conquer"phacoemulsification technique in the cataract surgery  

Scientific Electronic Library Online (English)

Full Text Available SciELO Cuba | Language: Spanish Abstract in spanish OBJETIVO: Valorar la técnica de facoemulsificación de "Divide y Vencerás" en la cirugía del cristalino en el Centro de Microcirugía Ocular del Instituto Cubano de Oftalmología "Ramón Pando Ferrer". MÉTODOS: Se realizó una investigación aplicada retrospectiva y descriptiva en 102 ojos con diagnóstico [...] de cataratas presenil y senil, de 52 pacientes que se les realizó facoemulsificación por la técnica de "Divide y Vencerás"en el Centro de Microcirugía Ocular del Instituto Cubano de Oftalmología "Ramón Pando Ferrer", en el período comprendido entre junio del 2006 a febrero del 2009. RESULTADOS: Se encontró que los mayores de 60 años representaron más de 75 % del total del universo estudiado. La mejor agudeza visual corregida en el posoperatorio mejoró a más de 0,7 en la escala de Snellen en el 85 % de los ojos. La diferencia del astigmatismo preoperatorio y posoperatorio fue 0,13 dioptrías. En la microscopia endotelial los cambios encontrados fueron de un 8,2 %, las complicaciones presentadas fueron de 2,8 %, ocurriendo con mayor frecuencia la rotura de cápsula posterior. CONCLUSIONES: Los mayores de 60 años representaron más de 75 % del total del universo estudiado, la agudeza visual corregida en el posoperatorio mejoró cuatro líneas en la escala de Snellen, el astigmatismo posoperatorio fue mínimo sin repercusión en la calidad visual de los pacientes, en la microscopia endotelial los cambios encontrados fueron mínimos y no tuvieron repercusión clínica para los pacientes, las complicaciones presentadas fueron muy bajas y se produjo con mayor frecuencia la rotura de cápsula posterior. Abstract in english OBJECTIVE:To assess the use of "Divide and Conquer" phacoemulsification technique in the lens surgery at the Ocular Microsurgery of "Ramón Pando Ferrer" Cuban Institute of Ophthalmology. METHODS: Retrospective and descriptive applied research was conducted in 102 eyes diagnosed with presenile and se [...] nile cataract from 52 patients who underwent "Divide and Conquer" phacoemulsification technique at the Ocular Microsurgery Center of "Ramón Pando Ferrer"from June 2006 to February 2009. RESULTS: It was found that patients over 60 years accounted for 75% of the universe of study; the best corrected visual acuity in the postoperative stage improved to more than 0,7 in the Snellen´s chart in 85% of the eyes, the difference between the preoperative and the postoperative astigmatism was 0,13 dioptries, the changes found in the endothelial microscopy represented 8,2%, the complications were observed in 2,8% of cases, being the most frequent the posterior capsule rupture. Ç CONCLUSIONS: The patients aged over 60 years accounted for 75% of the whole universe of study, the corrected visual acuity improved by four lines in the Snellen´s chart in the postoperative period, the postoperative astigmatism was minimal without any impact on the visual quality of the patients, there were minimal changes in the endothelial microscopy and no clinical impact was recorded. Complications were very low and the most frequent was the posterior chamber capsule rupture.

Juan Raúl, Hernández Silva; Ada Sonia, Villasol López; Meisy, Ramos López; Luis, Curbelo Cunill; Gilberto, Fernández Vásquez; Marcelino, Rio Torres.

389

Resultados de la técnica de facoemulsificación "Divide y Vencerás" en la cirugía de catarata Results of the "Divide and Conquer"phacoemulsification technique in the cataract surgery  

Directory of Open Access Journals (Sweden)

Full Text Available OBJETIVO: Valorar la técnica de facoemulsificación de "Divide y Vencerás" en la cirugía del cristalino en el Centro de Microcirugía Ocular del Instituto Cubano de Oftalmología "Ramón Pando Ferrer". MÉTODOS: Se realizó una investigación aplicada retrospectiva y descriptiva en 102 ojos con diagnóstico de cataratas presenil y senil, de 52 pacientes que se les realizó facoemulsificación por la técnica de "Divide y Vencerás"en el Centro de Microcirugía Ocular del Instituto Cubano de Oftalmología "Ramón Pando Ferrer", en el período comprendido entre junio del 2006 a febrero del 2009. RESULTADOS: Se encontró que los mayores de 60 años representaron más de 75 % del total del universo estudiado. La mejor agudeza visual corregida en el posoperatorio mejoró a más de 0,7 en la escala de Snellen en el 85 % de los ojos. La diferencia del astigmatismo preoperatorio y posoperatorio fue 0,13 dioptrías. En la microscopia endotelial los cambios encontrados fueron de un 8,2 %, las complicaciones presentadas fueron de 2,8 %, ocurriendo con mayor frecuencia la rotura de cápsula posterior. CONCLUSIONES: Los mayores de 60 años representaron más de 75 % del total del universo estudiado, la agudeza visual corregida en el posoperatorio mejoró cuatro líneas en la escala de Snellen, el astigmatismo posoperatorio fue mínimo sin repercusión en la calidad visual de los pacientes, en la microscopia endotelial los cambios encontrados fueron mínimos y no tuvieron repercusión clínica para los pacientes, las complicaciones presentadas fueron muy bajas y se produjo con mayor frecuencia la rotura de cápsula posterior.OBJECTIVE:To assess the use of "Divide and Conquer" phacoemulsification technique in the lens surgery at the Ocular Microsurgery of "Ramón Pando Ferrer" Cuban Institute of Ophthalmology. METHODS: Retrospective and descriptive applied research was conducted in 102 eyes diagnosed with presenile and senile cataract from 52 patients who underwent "Divide and Conquer" phacoemulsification technique at the Ocular Microsurgery Center of "Ramón Pando Ferrer"from June 2006 to February 2009. RESULTS: It was found that patients over 60 years accounted for 75% of the universe of study; the best corrected visual acuity in the postoperative stage improved to more than 0,7 in the Snellen´s chart in 85% of the eyes, the difference between the preoperative and the postoperative astigmatism was 0,13 dioptries, the changes found in the endothelial microscopy represented 8,2%, the complications were observed in 2,8% of cases, being the most frequent the posterior capsule rupture. Ç CONCLUSIONS: The patients aged over 60 years accounted for 75% of the whole universe of study, the corrected visual acuity improved by four lines in the Snellen´s chart in the postoperative period, the postoperative astigmatism was minimal without any impact on the visual quality of the patients, there were minimal changes in the endothelial microscopy and no clinical impact was recorded. Complications were very low and the most frequent was the posterior chamber capsule rupture.

Juan Raúl Hernández Silva

2010-01-01

390

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

International Nuclear Information System (INIS)

Locoregional control is adversely affected as clonogens from rapidly proliferating tumors repopulate during a course of radiation therapy. The cytostatic agent ?-difluoromethylornithine (DFMO) was investigated for its capacity to slow proliferation kinetics in human squamous cell carcinomas (SSC) of the head and neck (H ampersand 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 ampersand 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 x 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 ampersand N. 33 refs., 5 figs., 3 tabs

391

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

392

Marketing mix of chosen Slovak mineral water  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Considering its small area, Slovakia abounds in many sources of mineral waters and a considerable amount of them can be used for the commercial utilization. STN 86 8000 divides mineral waters in the natural mineral waters, natural mineral table waters and the natural mineral healing waters. Natural mineral water is, after the present norm, in effect water, which rises from natural trapped sources. This type of water contains more than 1 gram of dissolved substances or 1 gram of dissolved CO 2...

Juhanová Silvia; Tometz Ladislav

2001-01-01

393

On Typical Materials Acting as the Dividing Standard of the Development Stages of Human Substance Civilization  

Directory of Open Access Journals (Sweden)

Full Text Available During more than three million years, the substance civilization of human society went through the Stone Age, the Bronze Age, the Iron Age, the Steel and Cement Age, and the Silicon Age. At the beginning of the new century, the human society has entered into the Nanomaterials Age, which indicates that a completely new substance civilization of human society has started. This paper analyses and discusses why the typical materials serve as the only standard for dividing the eras of the substance civilization of human society. The author argues about the subject of dividing the substance civilization of human society. The goal is to initiate broad and thorough discussion of that subject so as to get a rather thorough understanding about it.

Bangwei Zhang

2012-06-01

394

IUE and Einstein survey of late-type giant and supergiant stars and the dividing line  

Science.gov (United States)

Results are presented on an IUE UV survey of 255 late-type G, K, and M stars, complementing the Maggio et al. (1990) Einstein X-ray survey of 380 late-type stars. The large data sample of X-ray and UV detections make it possible to examine the activity relationship between the X-ray and the UV emissions. The results confirm previous finding of a trend involving a steeply-dropping upper envelope of the transition region line fluxes, f(line)/f(V), as the dividing line is approached. This suggests that a sharp decrease in maximum activity accompanies the advancing spectral type, with the dividing line corresponding to this steep gradient region. The results confirm the rotation-activity connection for stars in this region of the H-R diagram.

Haisch, Bernhard M.; Bookbinder, Jay A.; Maggio, A.; Vaiana, G. S.; Bennett, Jeffrey O.

1990-01-01

395

Image Segmentation using Enhanced K-means clustering with divide and Conquer Approach  

Directory of Open Access Journals (Sweden)

Full Text Available This paper present image segmentation using Enhanced k-means clustering with divide and conquer approach. First we enhanced the k-means clustering and then segment the image using enhanced approach. K-means is one of the most popular clustering algorithms. The final clustering result of the k-means clustering algorithm greatly depends upon the correctness of the initial centroids, which are selected randomly. Many improvements were already proposed to improve the performance of k-means, but most of these require initial k centroids .In this paper we have proposed a new method enhanced k-means clustering algorithm with divided and conquer algorithm to find the initial centroids with reduced time complexity. In this paper we fixed the initial centroids which gives best result and in the final step we segment the image using enhanced clustering algorithm.

Babeesh Kumar

2014-07-01

396

The Effect of Digital Divide on Information Accessibility among Undergraduate Students of Ahmadu Bello University, Zaria  

Directory of Open Access Journals (Sweden)

Full Text Available The study was undertaken to evaluate the effect of digital divide on information accessibility among undergraduate students of Ahmadu Bello University, Zaria. To accomplish this study, survey research was employed in gathering information from the sample population. Face to face method otherwise known as on the spot method of administration of questionnaire was adopted. The questionnaire was divided into two sections. Bio-data & the respondent’s, at the course of this study, it was discovered that ICT are not readily available to most undergraduate students. The study also established that the gap between the haves and the have not to be bridge, the institution’s management will need to ensure that the class rooms are internet connected and made available in every department to provide easy access to digital information especially to those who are financially incapacitated.

N.E.E. Achebe

2013-03-01

397

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

2008-06-01

398

Energy scaling of femtosecond amplifiers using actively controlled divided-pulse amplification.  

Science.gov (United States)

Divided-pulse amplification is a promising method for the energy scaling of femtosecond laser amplifiers, where pulses are temporally split prior to amplification and coherently recombined afterwards. We present a method that uses an actively stabilized setup with separated stages for splitting and combining. The additional degrees of freedom can be employed to mitigate the limitations originating from saturation of the amplifier that cannot be compensated in passive double-pass configurations using just one common stage for pulse splitting and combining. In a first proof-of-principle experiment, actively controlled divided pulses are applied in a fiber chirped-pulse amplification system resulting in combined and compressed pulses with an energy of 1.25 mJ and a peak power of 2.9 GW. PMID:24562275

Kienel, Marco; Klenke, Arno; Eidam, Tino; Hädrich, Steffen; Limpert, Jens; Tünnermann, Andreas

2014-02-15

399

Evaluation of crystal oscillators and frequency dividers for high temperature operation  

Science.gov (United States)

Active and passive components of crystal oscillators and frequency dividers were tested to determine their performance at temperatures from 300 C to 350 C. The properties of GaAs JFETs were determined and their performance compared with that of silicon devices. Techniques for constructing breadboard circuits were assessed for operation in this temperature range. A Pierce oscillator and a multivibrator (Colorado crystal) oscillator were constructed and tested. Device failures are discussed.

1981-01-01

400

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

 
 
 
 
401

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 mod...

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

2013-01-01

402

Viscosity-Induced Crossing of the Phantom Divide in the Dark Cosmic Fluid  

CERN Document Server

Choosing various natural forms for the equation-of-state parameter w and the bulk viscosity \\zeta, we discuss how it is possible for a dark energy fluid to slide from the quintessence region across the divide w=-1 into the phantom region, and thus into a Big Rip future singularity. Different analytic forms for \\zeta, as powers of the scalar expansion, are suggested and compared with experiments.

Brevik, Iver

2013-01-01

403

Health expectancy in the Russian Federation: a new perspective on the health divide in Europe.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

OBJECTIVES: To compare life expectancy and healthy life expectancy in the Russian Federation and in countries of Eastern and Western Europe. METHODS: WHO mortality data and data on self-reported health from the World Values Survey and the Russian Longitudinal Monitoring Survey were used to compare the above three regions. Life expectancy was calculated using Sullivan's method, with years of life lived divided into healthy and unhealthy. The gap in healthy life expectancy between the Russian F...

Andreev Evgueni M.; McKee Martin; Shkolnikov Vladimir M

2003-01-01

404

East-West mortality divide and its potential explanations: proposed research agenda.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

There is a sharp divide in mortality between eastern and western Europe, which has largely developed over the past three decades and is caused mainly by chronic diseases in adulthood. The difference in life expectancy at birth between the best and worst European countries in this respect is more than 10 years for both sexes. The reasons for these differences in mortality are not clear and data currently available permit only speculation. The contributions of medical care and pollution are lik...

Bobak, M; Marmot, M.

1996-01-01

405

College Students Perception of the Second-Level Digital Divide: An Empirical Analysis  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The goal of this study was to take a comprehensive measure to the second-level digital divide, along with analyzing the various factors, and finding out the prominent factors. This study comes up with the hypothesis based on three Theoretical framework of Knowledge gap theory, Use and gratifications theory, Self-efficacy and attitude theory. Based on a survey on students of Jinan University (N=302), Multiple linear regression shows that the sensibility factors of Internet use, including the a...

Fanbin Zeng

2011-01-01

406

Contrasting nuclear dynamics of the caspase-activated DNase (CAD) in dividing and apoptotic cells  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Although compelling evidence supports the central role of caspase-activated DNase (CAD) in oligonucleosomal DNA fragmentation in apoptotic nuclei, the regulation of CAD activity remains elusive in vivo. We used fluorescence photobleaching and biochemical techniques to investigate the molecular dynamics of CAD. The CAD-GFP fusion protein complexed with its inhibitor (ICAD) was as mobile as nuclear GFP in the nucleosol of dividing cells. Upon induction of caspase-3–dependent apoptosis, activa...

Lechardeur, Delphine; Xu, Ming; Lukacs, Gergely L.

2004-01-01

407

Effect of Information and Communication Technologies (ICT) on Non-Industrial Countries-Digital Divide Model  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The influence of information and communication technology on the collective activities and interests of a broad range of people was discussed and analyzed. The important consequence of ICT called digital divide was mathematically modeled and the results analyzed. The closed loop feedback model proved the need for a society to be educationally, culturally, economically and politically ready to integrate and implement new technologies into its infrastructure.

Iskandarani, Mahmoud Z.

2008-01-01

408

Tumor cell heterogeneity: divided-colony assay for measuring drug response.  

Science.gov (United States)

In vitro tests for predicting the response of tumors to chemotherapeutic agents might be improved if they were modified to take into account tumor-cell heterogeneity. We have studied the heterogeneity of cellular growth rate and drug response in mouse fibroblast NIH 3T3 cells and in NIH 3T3 cells transformed with the human HRAS gene (homologue of the Harvey sarcoma virus oncogene v-Ha-ras) from the EJ human bladder carcinoma cell line. Growth-rate heterogeneity was detected as a broad distribution of numbers of cells per colony. In spite of this heterogeneity, secondary colonies have numbers of cells per colony that resemble that of the primary colony from which they were derived. The variance between unrelated secondary colonies is increased by HRASEJ. Colony-size measurements are reliable because primary colonies divided in half formed two groups of secondary colonies (on two separate plates) that had indistinguishable mean colony sizes. Based on these observations, a divided-colony procedure was devised to detect the drug response of heterogeneous cell populations. Primary colonies are divided into two groups of cells, one of which is treated with a drug and the other is left untreated as a control. The size distribution of treated secondary colonies is then compared to that of the untreated control and to that of the primary colony from which it was derived. The divided-colony procedure is proposed as a modification of the human-tumor-cloning system to increase the sensitivity and reliability of in vitro procedures used to determine the drug response of heterogeneous tumor-cell populations. PMID:3299370

Kuczek, T; Axelrod, D E

1987-07-01

409

Characteristics of Optimal Function for Ontology Similarity Measure via Multi-dividing  

Digital Repository Infrastructure Vision for European Research (DRIVER)

As a powerful tool, ontology has been widely applied in social science, medicine science and computer science. In computer networks, especially, ontology is used for search extension, thus boost the quality of information retrieval. Ontology concept similarity calculation is an essential problem in these applications. A new method to get similarity between vertices on ontology graph is by machine learning, and multi-dividing algorithm is suitable for ontology problem. It is usually get an ont...

Wei Gao; Tianwei Xu

2012-01-01

410

Crossing the digital divide: an interoperable solution for sharing time series and coverages in Earth sciences  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In a world driven by the Internet and the readily accessible information it provides, there exists a high demand to easily discover and collect vast amounts of data available over several scientific domains and numerous data types. To add to the complexity, data is not only available through a plethora of data sources within disparate systems but also represents differing scales of space and time. One clear divide that exists in the world of information science and technology is the disjoint ...

2012-01-01

411

Asteroid Lightcurve Analysis at CS3-Palmer Divide Station: 2014 March-June  

Science.gov (United States)

Lightcurves for 19 main-belt asteroids were obtained at the Center for Solar System Studies-Palmer Divide Station (CS3-PDS) from 2014 March through June. Some of the objects were members of the Hungaria group/family, observed as follow-up to previous apparitions to check for the possibility of undiscovered satellites or to provide additional data for spin axis and shape modeling.

Warner, Brian D.

2014-10-01

412

Bridging “Digital Divide” in Medium and Small-sized Enterprises’Informatization  

Directory of Open Access Journals (Sweden)

Full Text Available Great significance lies in the informatization of medium and small-sized enterprises in that it will convert the economic growth method and improve those enterprises’ competitive abilities at the international market. However, “digital divide” confronted in their informatization must be bridged by reinforcing the support for their informatization process, achieving the goal of informatization step by step, actively promoting “the Enterprises’ Informatization Project” and soundly carrying out the conversion of medium and small-sized enterprises’ focus.

Baozhen Chen

2009-06-01

413

Heat control in HVDC resistive divider by PID and NN controllers  

International Nuclear Information System (INIS)

In this study, a control system is presented that is devised to increase measurement precisions within a prototype high voltage DC resistive divider (HVDC-RD). Since one of the major sources of measurement errors in such devices is the self heating effect, a system controlling the temperature within the high voltage DC resistive divider is devised so that suitable and stable temperature conditions are maintained that, in return, will decrease the measurement errors. The resistive divider system is cooled by oil, and PID and neural network (NN) controllers try to keep the temperature within the prescribed limits. The system to be controlled exhibits a nonlinear character, and therefore, a control approach based on NN controllers is proposed. Thus, a system that can fulfill the various requirements dictated by the designer is constructed. The performance of the NN controller is compared with that of the PID controller developed for the same purpose, and the values of the performance indices indicate the superiority of the NN controller over that of the classical PID controller

414

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

2009-05-01

415

Divided attention in older but not younger adults is impaired by anxiety.  

Science.gov (United States)

It has been hypothesized that the disruptive effects of negative emotional states, such as anxiety and depression, may contribute to poorer performance in older age. Some studies have reported that higher levels of anxiety are associated with poorer cognitive performance in older adults but not younger adults. The author examined if age and anxiety interact with performance by comparing the performance of normal healthy younger and older adults on cognitive and motor tests under conditions of selective and divided attention. Ninety-two older adults (mean age=70.1 years, SD=7.1 years) and 78 younger adults (mean age=18.8 years, SD=1.9 years), matched on education, vocabulary, and self-reported health, performed a word-comparison and pursuit-rotor task under conditions of selective and divided attention. Anxiety was assessed using the Speilberger State-Trait anxiety scale. The hypothesis was supported: higher anxiety was associated with poorer divided attention performance in older, but not younger, adults. Anxiety was not associated with poorer motor performance in older adults. Implications of the results for cognitive-resource theories of aging cognition are discussed. PMID:12623724

Hogan, Michael J

2003-01-01

416

Retention Time Alignment of LC/MS Data by a Divide-and-Conquer Algorithm  

Science.gov (United States)

Liquid chromatography-mass spectrometry (LC/MS) has become the method of choice for characterizing complex mixtures. These analyses often involve quantitative comparison of components in multiple samples. To achieve automated sample comparison, the components of interest must be detected and identified, and their retention times aligned and peak areas calculated. This article describes a simple pairwise iterative retention time alignment algorithm, based on the divide-and-conquer approach, for alignment of ion features detected in LC/MS experiments. In this iterative algorithm, ion features in the sample run are first aligned with features in the reference run by applying a single constant shift of retention time. The sample chromatogram is then divided into two shorter chromatograms, which are aligned to the reference chromatogram the same way. Each shorter chromatogram is further divided into even shorter chromatograms. This process continues until each chromatogram is sufficiently narrow so that ion features within it have a similar retention time shift. In six pairwise LC/MS alignment examples containing a total of 6507 confirmed true corresponding feature pairs with retention time shifts up to five peak widths, the algorithm successfully aligned these features with an error rate of 0.2%. The alignment algorithm is demonstrated to be fast, robust, fully automatic, and superior to other algorithms. After alignment and gap-filling of detected ion features, their abundances can be tabulated for direct comparison between samples.

Zhang, Zhongqi

2012-04-01

417

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

2012-06-01

418

Divided nevus of the eyelid: review of embryology, pathology and treatment.  

Science.gov (United States)

Divided nevus, which is also known as "kissing nevus," "split ocular nevus" and "panda nevus" is a rare congenital dermatological abnormality that occurs on opposing margins of upper and lower eyelids. There is a paucity of literature on this rare anomaly, with most knowledge from this disease process derived from isolated case reports and series. The purpose of this study is to report a new case of divided nevus of the eyelid and to discuss the unique embryology, pathology, and potential treatment options for this rare entity. A systematic review of literature was performed of the English literature on PubMed and Medline with just under 150 cases reported in the literature. The vast majority of the divided nevi seen in this review were medium sized and of the melanocytic intradermal type. There were no described cases of malignant transformation in any of the documented cases. Numerous methods for reconstruction were described including the entire reconstructive ladder with both one and two staged approaches. In this review, we present basic guidelines to the reconstruction of these complicated defects, although ultimate treatment should be individualized and dependent on surgeon comfort. PMID:23380310

Desai, Shaun C; Walen, Scott; Holds, John B; Branham, Gregory

2013-01-01

419

Methods for Least Squares Data Smoothing by Adjustment of Divided Differences  

Science.gov (United States)

A brief survey is presented for the main methods that are used in least squares data smoothing by adjusting the signs of divided differences of the smoothed values. The most distinctive feature of the smoothing approach is that it provides automatically a piecewise monotonic or a piecewise convex/concave fit to the data. The data are measured values of a function of one variable that contain random errors. As a consequence of the errors, the number of sign alterations in the sequence of mth divided differences is usually unacceptably large, where m is a prescribed positive integer. Therefore, we make the least sum of squares change to the measurements by requiring the sequence of the divided differences of order m to have at most k-1 sign changes, for some positive integer k. Although, it is a combinatorial problem, whose solution can require about O(nk) quadratic programming calculations in n variables and n-m constraints, where n is the number of data, very efficient algorithms have been developed for the cases when m = 1 or m = 2 and k is arbitrary, as well as when m>2 for small values of k. Attention is paid to the purpose of each method instead of to its details. Some software packages make the methods publicly accessible through library systems.

Demetriou, I. C.

2008-09-01

420

Mapping and explaining the use of the left-right divide  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english This study is about mapping and explaining the use of the Left-Right divide across 14 countries from 5 Continents and relies on the richness of the post electoral mass surveys from the Comparative National Election Project: 14 countries and 18 elections spread over 5 continents. The paper shows not [...] only how extensively the LR divide is used in these 14 countries, but also explains variation across both individuals and countries in terms of the factors determining LR recognition and use. Overall, it is shown that, although seen world-wide, the LR divide (both for self-placement and party placement) is more present in long consolidated and middle-aged democracies and countries with freer media systems than in new democracies and societies with less free media systems. In the case of parties LR placement, party size also counts: larger parties are more easily placed. Additionally, we also show that LR recognition is more socially and politically determined in long consolidated and middle-aged democracies and in countries with more freedom of the press than in new democracies and in systems with less free media system. These findings add to the existing knowledge about these topics because previous studies were either country/Continent specific, or, if global in nature, never invested in explaining individual and system variation across 14 from 5 Continents. Besides, these findings mean that in the long term probably the new democracies will converge with the long consolidated or middle-aged ones, but this is an empirical question to be researched in future studies.

André, Freire; Kats, Kivistik.

 
 
 
 
421

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

2011-10-01

422

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)

423

MEPs divided ahead of vote on medical devices | EurActiv  

...MEPs divided ahead of vote on medical devices | EurActiv The European Commission has tabled new rules for the approval of medical devices ...as to how far the proposal should go in harmonising the way medical devices should be approved in future. special-report-medical-devices-regulation,health,medical devices ...harm: The EU's strategy under review The battle for EU consumer rights Medical Devices: A new regulatory landscape Consumers: Buying green? ... UN Development Goals: Countdown to 2015 Payments services directive II Medical devices regulation Building the way out of the crisis Future of aviation: ...

424

Asteroid Lightcurve Analysis at the Palmer Divide Observatory: 2010 September-December  

Science.gov (United States)

Lightcurves for 23 asteroids were obtained at the Palmer Divide Observatory (PDO) from 2010 September through December: 795 Fini, 1506 Xosa, 1600 Vyssotsky, 2518 Rutllant, 3873 Roddy, 8380 Tooting, 9774 Annjudge, 1118 Modra, (11279) 1989 TC, 11976 Josephthurn, (16026) 1999 CM118, (24815) 1994 VQ6, (44600) 1999 RU10, (48601) 1995 BL, (48707) 1996 KR1, (74219) 1998 RM78, (75489) 1999 XO178, (86192) 1999 SV1, (86217) 1999 TB35, (86257) 1999 TK207, (100926) 1998 MQ, (107668) 2001 FY4, and (150370) 2000 CG65.

Warner, Brian D.

2011-04-01

425

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

2012-03-01

426

Arnol'd tongues for a resonant injection-locked frequency divider: analytical and numerical results  

DEFF Research Database (Denmark)

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 Arnol’d 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.

Schilder, Frank

2010-01-01

427

Library 2.0 - crossing or burning bridges over the digital divide?  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper describes a qualitative case study on the effect of the Library 2.0 model on the digital divide. It’s inspired by the new question of the public libraries place in the modern information society and uses three Scandinavian texts on the organizational, patron and society perspective. Interviews with a chief librarian in charge of an adaption to the Library 2.0 in a Swedish public library and two of its patrons have been conducted to learn more about the subject. Conclusions ...

Weman, Maria

2010-01-01

428

A Markov Model for Human Resources Supply Forecast Dividing the HR System into Subgroups  

Directory of Open Access Journals (Sweden)

Full Text Available Modeling the manpower management mainly concerns the prediction of future behavior of employees. The paper presents a predictive model of numbers of employees in a hierarchical dependent-time system of human resources, incorporating subsystems that each contains grades of the same family. The proposed model is motivated by the reality of staff development which confirms that the path evolution of each employee is usually in his family of grades. That is the reason of dividing the system into subgroups and the choice of the superdiagonal transition matrix.

Rachid Belhaj

2013-08-01

429

Asteroid Lightcurve Analysis at the Palmer Divide Observatory - December 2006 - March 2007  

Science.gov (United States)

Lightcurves for 32 asteroids were obtained at the Palmer Divide Observatory from late December 2006 through March 2007: 22 Kalliope, 36 Atalante, 92 Undina, 108 Hecuba, 154 Bertha, 170 Maria, 275 Sapientia, 572 Rebekka, 708 Raphaela, 947 Monterosa, 1072 Malva, 1323 Tugela, 1348 Michel, 2449 Kenos, 3225 Hoag, 3410 Vereshchagin, 4764 Joneberhart, 4765 Wasserburg, 4898 Nishiizumi, 6646 Churanta, 6870 Pauldavies, (7783) 1994 JD, 9554 Dumont, (9873) 1992 GH , (16585) 1992 QR, (16681) 1994 EV7, (30856) 1991 XE, (40250) 1998 XG16, (69350) 1993 YP, (101549) 1998 YY29, (138666) 2000 RX96, and 2001 BE10.

Warner, Brian D.

2007-09-01

430

eGY-Africa: addressing the digital divide for science in Africa  

Science.gov (United States)

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. In many sub-Saharan African countries, education and research sector suffers some of the worst deficiencies in access to the Internet, despite progress in the 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 still 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. eGYAfrica workshops have been held approximately bi annually, the last of which was in Nairobi Kenya.

Baki, Paul; Nguno, Anna; Barton, Charles; Amaeshi, Larry; Tenthani, Chifundo; Petitdidier, Monique; Cottrell, Les

2013-04-01

431

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

432

Divide by 4 the emissions: the Negatep scenario; Diviser par 4 nos rejets: le scenario Negatep  

Energy Technology Data Exchange (ETDEWEB)

The Negatep scenario is proposed in the framework of the french energy policy, aiming to divide by 4 the CO{sub 2} emissions for 2050. After an evaluation of the today situation concerning the energy consumption and needs, the scenario proposes some ways of energy conservation in different sectors, other energy sources in place of the fossil fuels, the energy needs by sectors. The last part of the document provides the main consumption posts, the CO{sub 2} releases and the approach. (A.L.B.)

Acket, C.; Bacher, P

2007-01-15