WorldWideScience
1

Silicon drift detector with a continuous implanted resistor as divider-drift electrode  

OpenAIRE

The peculiarity of the drift chamber prototype presented in this paper is the high voltage divider, which is implanted in the entire sensitive zone, thus, it has at the same time the function of drift electrode. This brings some advantage: (1) there is no metallization in the sensitive zone, hence, the detector can have a wider spectrum of applications (e.g. detection of soft X-rays and low-energy electrons); (2) the mask design and detector fabrications are made simpler; (3) a unifo...

Beole, Stefania

1998-01-01

2

Water electrolysis: Divide and conquer  

Science.gov (United States)

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

Mallouk, Thomas E.

2013-05-01

3

Water-dissolved high-voltage resistors. Development, study, application. Review  

International Nuclear Information System (INIS)

The review is devoted to developments, investigations and uses of high-voltage resistors based on aqueous solutions of salts, acids and their mixtures. The water-dissolved resistors (WDR) are intended for power electrophysical installations (high-voltage pulse generators and current limiters) applied in plasma physics, radiation chemistry, controllable thermonuclear synthesis and high-power charged particle beams. These WDR possess the bulk electrical strength up to 300 kV/cm, the high dissipation capability of electrical power per mass unit, the high reliability and service life. The electrical properties and the behavior of solutions in electrical fields up to 50 kV/ cm are considered. The particular attention is given to sealed small-size WDR which are efficient in any positions in volumes with rarefied and compressed gases, with oil insulation

4

Assessment of water-cooled breeder resistors for long pulse injection in acceleration power supply on positive-ion-based NBI system  

International Nuclear Information System (INIS)

Water-cooled breeder resistor, utilized in acceleration power supply on the positive-ion-based NBI system, has been designed to realize 100 s injections of intense neutral beams in JT-60 Super Advanced. The design is progressed with minimizing modification of existing electric parts. Existing water-cooled breeder resistors is composed of three water vessels connected in parallel, in each of which 150 resistors of 600 ? are immersed and connected in series. Although the manufacturing company requires entire replacement of water- cooled breeder, the careful assessment of thermal load allows only the replacement of the resistors inside the water vessel. The resistance of one resistors is required to be increased from 600 ? to 2.5 k?. The total resistance of the breeder is ?140 k? that includes the resistance of water. In the operation with the breeder of ?140 k?, stable production of 85 keV, 55 A D+ beams, allowing 2 MW of the designed injection power, was confirmed without instabilization of the acceleration power supply. This modification significantly reduces the cost and the manufacturing time. (author)

5

Climate Interpretations from the WAIS Divide Water Isotope Record  

Science.gov (United States)

Ultra-high resolution water isotope measurements (?D, ?18O and deuterium excess) from the WAIS Divide ice core have been analyzed using a continuous flow system (CFA). The CFA measurements (INSTAAR, University of Colorado) have been averaged to 1 cm and compared with 50 cm discrete measurements (Isolab, University of Washington). Downsampling the CFA data, we find significant (>99%) multi-taper coherence between the two measurement techniques (?D and ?18O). The deuterium excess measurements are more difficult to reproduce at high-resolution, but are significantly coherent at longer time scales (100-1000 years). Frequency analysis of the CFA water isotope signal (?D and ?18O) shows 1-year power persists throughout the Holocene and part-way into the Glacial. At 5 ka bp about 50% of the initial water isotope annual amplitude remains, whereas at 9 ka bp about 20% remains. By 15 ka bp yearly power has mostly disappeared. We use the exceptional preservation of the water isotope signal to undertake various analyses including: 1) Interpretation of abrupt climate changes (e.g. AIM events), 2) Frequency analysis of ENSO-type climate oscillations throughout the Holocene and the late-Glacial (e.g. 2-7 year periodicities), and 3) The effects of diffusion on the water isotope signal (e.g. diffusion constrains the temperature, accumulation during firn densification, and dynamic thinning history, which could be used to invert for these parameters). These analyses are ongoing as we continue to develop our methodologies and CFA system processing code.

Jones, Tyler R.; White, James W. C.; Cuffey, Kurt M.; Steig, Eric J.; Fudge, Tyler J.; Vaughn, Bruce H.; Morris, Valerie A.; Gkinis, Vasileios; Markle, Bradley R.; Schoenemann, Spruce W.

2014-05-01

6

A high power water cooled resistor for the high voltage power supply in the TRIUMF RF system  

International Nuclear Information System (INIS)

The TRIUMF RF system high voltage power supply requires 0.5 ohm current limiting resistors to protect amplifier components during transients and crowbar operations. The crowbar typically causes a 16,000 amp transient pulse followed by a 4,000 amp current for 55 ms until the circuit breaker opens. The resulting stresses produced catastrophic failure of the original design within 100 crowbar cycles. A new resistor design has been developed to improve heat transfer characteristics and reduce current densities. Design changes were evaluated during extensive testing of a full scale model. The test results are reported with the resulting design described in detail

7

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

8

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

9

Fixed Resistor Placement  

Science.gov (United States)

Flash Player 6 or greater is required to view this website. You are a student worker in the ACME Community College electronics department. Students have left 50 fixed resistors on the lab bench. Your supervisor has asked you to return these resistors to the proper drawers and she has given you 10 minutes to complete the task. Enter your name and click the Start button. A fixed resistor will be displayed. Click on and drag the resistor to the proper drawer. If placed in the correct drawer, a green light will be displayed. If placed incorrectly, a red light will be displayed and the resistor will be displayed at the bottom of the screen.

10

Breakdown voltage of metal-oxide resistors in liquid argon  

CERN Document Server

We characterized a sample of metal-oxide resistors and measured their breakdown voltage in liquid argon by applying high voltage (HV) pulses over a 3 second period to simulate the electric breakdown in a HV-divider chain. All resistors had higher breakdown voltages in liquid argon than their vendor ratings in air at room temperature. Failure modes range from full destruction to coating damage. In cases where breakdown was not catastrophic, subsequent breakdown voltages were lower in subsequent measuring runs. One resistor type withstands 131\\,kV pulses, the limit of the test setup.

Bagby, L F; James, C C; Jones, B J P; Jostlein, H; Lockwitz, S; Naples, D; Raaf, J L; Rameika, R; Schukraft, A; Strauss, T; Weber, M S; Wolbers, S A

2014-01-01

11

Resistor assemblies for NEC accelerators  

Energy Technology Data Exchange (ETDEWEB)

Resistor assemblies have been under test in the 14UD Pelletron at the Australian National University in Canberra, Australia since February 1988, with no failures. A full set of resistors was installed in March 1989 and their performances has been satisfactory. The design incorporates coaxial shielding and individual mounting resulting in excellent flexibility in installation and maintenance. A pair of resistors is used to span each insulated gap. The design can be easily adapted to other types of accelerators. (orig.).

Weisser, D.C. (Australian National Univ., Canberra. Dept. of Nuclear Physics (Australia))

1990-02-01

12

Resistor assemblies for NEC accelerators  

International Nuclear Information System (INIS)

Resistor assemblies have been under test in the 14UD Pelletron at the Australian National University in Canberra, Australia since February 1988, with no failures. A full set of resistors was installed in March 1989 and their performances has been satisfactory. The design incorporates coaxial shielding and individual mounting resulting in excellent flexibility in installation and maintenance. A pair of resistors is used to span each insulated gap. The design can be easily adapted to other types of accelerators. (orig.)

13

Resistor assemblies for NEC accelerators  

Science.gov (United States)

Resistor assemblies have been under test in the 14UD Pelletron at the Australian National University in Canberra, Australia since February 1988, with no failures. A full set of resistors was installed in March 1989 and their performances has been satisfactory. The design incorporates coaxial shielding and individual mounting resulting in excellent flexibility in installation and maintenance. A pair of resistors is used to span each insulated gap. The design can be easily adapted to other types of accelerators.

Weisser, D. C.

1990-02-01

14

Breakdown voltage of metal-oxide resistors in liquid argon  

Science.gov (United States)

We characterized a sample of metal-oxide resistors and measured their breakdown voltage in liquid argon by applying high voltage (HV) pulses over a 3 second period. This test mimics the situation in a HV-divider chain when a breakdown occurs and the voltage across resistors rapidly rise from the static value to much higher values. All resistors had higher breakdown voltages in liquid argon than their vendor ratings in air at room temperature. Failure modes range from full destruction to coating damage. In cases where breakdown was not catastrophic, subsequent breakdown voltages were lower in subsequent measuring runs. One resistor type withstands 131 kV pulses, the limit of the test setup.

Bagby, L. F.; Gollapinni, S.; James, C. C.; Jones, B. J. P.; Jostlein, H.; Lockwitz, S.; Naples, D.; Raaf, J. L.; Rameika, R.; Schukraft, A.; Strauss, T.; Weber, M. S.; Wolbers, S. A.

2014-11-01

15

Non-temperature dependent resistor at low temperatures  

Energy Technology Data Exchange (ETDEWEB)

We measured the temperature dependence of metal film chip resistors (SUSUMU Co., Ltd. RR1220 100 {omega}, 1 k{omega}, 10 k{omega} and 1 M{omega}) from 45 mK to 300 K. Although the temperature dependence of these resistors R was not monotonic, the changes in resistance (R(T)-R(T=300 K))/R(T=300 K) were {approx}1% (except 1 M{omega}). Therefore we can make a filter and a divider without taking the temperature dependence of the resistor into consideration. Below liquid helium temperature, the resistance of the chip resistor increases as log T with decreasing temperature. It is expected that the temperature dependence of log T is due to the Kondo effect.

Sato, Akira; Iwasa, Akio

2003-05-01

16

Experimental and Analytic Studies of an RF Load Resistor  

International Nuclear Information System (INIS)

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

17

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

18

MOS integrated circuits with implanted resistor elements  

International Nuclear Information System (INIS)

Resistor elements for mos integrated circuits are made by an ion implant step compatable with a self-aligned N-channel silicongate process. The resistor elements are beneath the field oxide in the finished device, although the implant step is prior to formation of the thick oxide. Resistors of this type are ideally suited for load devices in static ram cells

19

Bacterioplankton in Antarctic Ocean Waters During Late Austral Winter: Abundance, Frequency of Dividing Cells, and Estimates of Production  

OpenAIRE

Bacterioplankton productivity in Antarctic waters of the eastern South Pacific Ocean and Drake Passage was estimated by direct counts and frequency of dividing cells (FDC). Total bacterioplankton assemblages were enumerated by epifluorescent microscopy. The experimentally determined relationship between in situ FDC and the potential instantaneous growth rate constant (?) is best described by the regression equation ln ? = 0.081 FDC ? 3.73. In the eastern South Pacific Ocean, bacterioplank...

Hanson, R. B.; Shafer, David; Ryan, Theresa; Pope, Daniel H.; Lowery, H. Kenneth

1983-01-01

20

DIGITAL DIVIDE  

Directory of Open Access Journals (Sweden)

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

SANTOSH GOBRU JADHAO

2013-02-01

21

Silicon thermal conductivity detector (TCD) with the Pt resistors  

Science.gov (United States)

Pt resistors formation technology for the thermal conductivity detector (TCD) is presented. Channels for the gas flow were milled in the glass plate and etched in the silicon chip with use of the TMAH+ water solution. Resistors made up of the thin Pt layer, were located across the channels on the silicon chips. They were connected through the contract windows in the Si3N4 and SiO2 layers, with the n+-type regions of the p-type, (100) silicon substrate substrate. BSC-type contacts to the bonding pads allowed electrical contact to the bonding pads located on the opposite side of the silicon substrate. Resistors were electrically tested as a detector heaters and thermoresistors.

Lysko, Jan M.; Gorska, Marianna; Wrzesinska, Hanna; Hejduk, Krzysztof; Latecki, Bogdan; Lozinko, Joanna

2003-09-01

22

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

23

Resistance contact thin-film resistor  

Directory of Open Access Journals (Sweden)

Full Text Available The analytical model of the calculation of the contact resistance of the thin-film resistor is Offered. The Explored dependency of the contact resistance from wedge of the pickling. The Considered influence adhesive layer on warm-up stability of the resistor. They Are Received formulas of the calculation systematic and casual inaccuracy contributed by contact resistance.

Spirin V. G.

2008-10-01

24

Continental divide  

International Nuclear Information System (INIS)

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

25

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)

26

Design of a Compact Dump Resistor System for LCD Magnet  

CERN Document Server

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

Gaddi, A

2010-01-01

27

Liquid resistor for protecting superconducting coil  

International Nuclear Information System (INIS)

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

28

Improvement in temperature stability of standard resistors using heat pipe technology  

Science.gov (United States)

The temperature stability of standard resistors plays an important role in assuring the accuracy of resistance measurements that use resistance ratio bridges to calibrate standard platinum resistance thermometers (SPRTs) on the International Temperature Scale of 1990 (ITS-90). Therefore, during resistance measurements, the resistors are always kept in temperature controlled oil or air baths and enclosures to maintain a constant temperature. In order to achieve better temperature stability and reduce the effects of temperature fluctuations on the resistance of a standard resistor, an annular water heat pipe thermostat immersed in a mineral oil bath was developed to accommodate and stabilize a standard resistor. Also, the thermostat's performance was characterized. The results showed that the temperature stability of standard resistors was within 1 mK after using the heat pipe thermostat compared with that of 30 mK for the oil bath. Therefore, the temperature stability of standard resistors was improved by more than one order of magnitude, which was attributable to the good thermal self-regulating abilities of the water heat pipe.

Yan, X.; Duan, Y.; Zhang, J. T.; Wang, W.; Wang, L.; Li, J.

2013-09-01

29

The viscoelastic divider  

Energy Technology Data Exchange (ETDEWEB)

Proposed is a viscoelastic divider for separating drilling and plugging muds during cementing of wells, which contains a water soluble polymer, resin and an additive as the base. In order to increase the thermal stability, a 5% aqueous solution of hypane is used as the water soluble polymer, wood resin as the resin and a 37-40% aqueous solution of formaldehyde and a 15% aqueous solution of hydrochloric acid are used as the additive.

Bondaruk, T.M.; Andriychuk, I.S.; Lishchuk, Ya.F.; Rud' ko, M.I.; Sobolevskiy, Ya.Yu.

1979-05-25

30

Manufacturing Precision Polysilicon Resistors Using Ion Implantation  

Science.gov (United States)

Two techniques exist to form high resistance, precision polysilicon resistors. In both cases polysilicon films are degenerative doped with phosphorus to form the gate electrode. In the first method, phosphorus at a dose near 1×1015at/cm2 is implanted in a portion of the second level polysilicon that is masked during the previous implant. Resistors can also be formed in a portion of the first level polysilicon by counter doping with boron. This provides resistors with lower temperature coefficients of resistance and the ability to manufacture precision resistors in a single poly process. As resistors comprise only a small portion of the die (lot size, with small lots showing better uniformity. Variation across the wafer manifested as horizontal bands with the lowest values in the center of the wafer. The cause of the nonuniformity was determined to be photoresist outgassing and ion neutralization. Photoresist breaks down under ion bombardment releasing large quantities of hydrogen gas. The released gas neutralizes incoming positive ions. This results in overdosing, which lowers the resistance most dramatically in the center of the wafer where the quantity of photoresist is greater.

Towner, Janet M.

2006-11-01

31

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

32

Determination of cadmium in individual organs and divided shells of sea water clam by atomic absorption spectrometry with a carbon tube atomizer  

International Nuclear Information System (INIS)

Cadmium contents in individual organs and divided shells of sea water clam were estimated by atomic absorption with a carbon tube atomizer. After samples were digested with nitric acid, cadmium was separated from the interfering sample matrices by extracting it into diisobutyl ketone as diethyldithiocarbamate. By this method, 0.06 -- 0.75 ppb of cadmium was found in the divided shells. In the shellfish, cadmium was enriched to a very high extent in the kidney, to some degree in the organ of Keber. (author)

33

Anisotropic random resistor networks a model for piezoresistive response of thick-film resistors  

CERN Document Server

A number of evidences suggests that thick-film resistors are close to a metal-insulator transition and that tunneling processes between metallic grains are the main source of resistance. We consider as a minimal model for description of transport properties in thick-film resistors a percolative resistor network, with conducting elements governed by tunneling. For both oriented and randomly oriented networks, we show that the piezoresistive response to an applied strain is model dependent when the system is far away from the percolation thresold, while in the critical region it acquires universal properties. In particular close to the metal-insulator transition, the piezoresistive anisotropy show a power law behavior. Within this region, there exists a simple and universal relation between the conductance and the piezoresistive anisotropy, which could be experimentally tested by common cantilever bar measurements of thick-film resistors.

Grimaldi, C; Strässler, S

2002-01-01

34

Process for forming synapses in neural networks and resistor therefor  

Science.gov (United States)

Customizable neural network in which one or more resistors form each synapse. All the resistors in the synaptic array are identical, thus simplifying the processing issues. Highly doped, amorphous silicon is used as the resistor material, to create extremely high resistances occupying very small spaces. Connected in series with each resistor in the array is at least one severable conductor whose uppermost layer has a lower reflectivity of laser energy than typical metal conductors at a desired laser wavelength.

Fu, Chi Y. (San Francisco, CA)

1996-01-01

35

Simulation study of resistor networks applied to an array of 256 SiPMs  

OpenAIRE

In this work we describe a procedure to reduce the number of signals detected by an array of 256 Silicon Photo-multipliers (SiPMs) using a resistor network to divide the signal charge into few readout channels. Several configurations were modeled, and the pulsed signal at the readout contacts were simulated. These simulation results were experimentally tested on a specifically designed and manufactured set of printed circuit boards. Three network configurations were modeled. The modeling prov...

Gonza?lez Marti?nez, Antonio Javier; Moreno, Manuel; Barbera?, Julio; Conde Castellanos, Pablo Eloy; Herna?ndez Herna?ndez, Liczandro; Moliner Marti?nez, Laura; Monzo? Ferrer, Jose? Mari?a; Orero Palomares, Abel; Peiro? Cloquell, Antonio; Polo, Ramiro; Rodri?guez A?lvarez, Mari?a Jose?; Ros Garci?a, Ana; Sa?nchez Marti?nez, Filomeno; Soriano Asensi, Antonio; Vidal San Sebastian, Luis Fernando

2013-01-01

36

Development of resistor assemblies at 14 UD pelletron accelerator facility BARC-TIFR, Mumbai  

International Nuclear Information System (INIS)

An important consideration in high voltage design of an electrostatic accelerator is the potential grading system used to divide the terminal potential equitably (or as required) across the column or tube electrode gaps. This is generally accomplished by tapping the electrode potentials from across a resistor-chain or from a series of corona gaps as in the Pelletron Accelerator. However, each potential grading system has its own set of advantages and disadvantages

37

Rational and irrational numbers from unit resistors  

Science.gov (United States)

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

Kasperski, Maciej; K?obus, Waldemar

2014-01-01

38

FGMOS Based Voltage-Controlled Grounded Resistor  

Directory of Open Access Journals (Sweden)

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

R. Pandey

2010-09-01

39

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

40

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

International Nuclear Information System (INIS)

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

41

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

42

Noise characteristics of silicon thin-film resistors  

Energy Technology Data Exchange (ETDEWEB)

The results of studies of the spectral density and energy equivalent of the noise of thin-film resistors based on amorphous silicon and of stock high-value KIM and KVM resistors are reported. It is shown that the main source of excess resistor noise is dependence of the resistive component of impedance on frequency. The dependence of the spectral density of the noise voltage of the current noise of silicon resistors on the applied voltage is described by the formula S/sub c/ = Bv/sup 2//f/sup 1,6/ with B = (1.4-1.7) x 10/sup -12/ Hz/sup 0.6/. Silicon resistors have considerably better noise characteristics than do stock resistors.

Belogurov, S.V.; Gostilo, V.V.; Yurov, A.S.

1987-06-01

43

Noise characteristics of silicon thin-film resistors  

International Nuclear Information System (INIS)

The results of studies of the spectral density and energy equivalent of the noise of thin-film resistors based on amorphous silicon and of stock high-value KIM and KVM resistors are reported. It is shown that the main source of excess resistor noise is dependence of the resistive component of impedance on frequency. The dependence of the spectral density of the noise voltage of the current noise of silicon resistors on the applied voltage is described by the formula S/sub c/ = Bv2/f/sup 1,6/ with B = (1.4-1.7) x 10-12 Hz/sup 0.6/. Silicon resistors have considerably better noise characteristics than do stock resistors

44

Plan for study of water and its relation to economic development in the Green River and Great Divide basins in Wyoming  

Energy Technology Data Exchange (ETDEWEB)

Development of extensive coal, oil, gas, trona, and oil-shale resources as well as other developments in the Green River and Great Divide basins will require a projected increase in water consumption of 490,000 acre-ft (600 cu hm) per year by 2020. Developments of energy resources in other parts of Wyoming also will require large amounts of water; transbasin diversion of Green River water to other areas could total an additional 270,000-acre-ft (330 cu hm) per year. In anticipation of this increased demand, water planners and managers need much more information about available ground and surface waters, present quality of the waters, and hydrologic effects that would be caused by development of energy resources. The U.S. Geological Survey is conducting an extensive hydrologic study of the basins. This report summarizes the study plan and discusses particular methods of approach that would be utilized in the study. The principal objectives of the study are given. (73 refs.)

Lowham, H.W.; De Long, L.L.; Peter, K.D.; Wangsness, D.J.; Head, W.J.

1976-05-01

45

Studies of tantalum nitride thin film resistors  

International Nuclear Information System (INIS)

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

46

A model of transport nonuniversality in thick-film resistors  

CERN Document Server

We propose a model of transport in thick-film resistors which naturally explains the observed nonuniversal values of the conductance exponent t extracted in the vicinity of the percolation transition. Essential ingredients of the model are the segregated microstructure typical of thick-film resistors and tunneling between the conducting grains. Nonuniversality sets in as consequence of wide distribution of interparticle tunneling distances.

Grimaldi, C; Ryser, P; Strässler, S

2003-01-01

47

Multifractal Properties of the Random Resistor Network  

CERN Document Server

We study the multifractal spectrum of the current in the two-dimensionalrandom resistor network at the percolation threshold. We consider two ways ofapplying the voltage difference: (i) two parallel bars, and (ii) two points.Our numerical results suggest that in the infinite system limit, theprobability distribution behaves for small current i as P(i) ~ 1/i. As aconsequence, the moments of i of order q

Barthelemy, M; Havlin, S; Stanley, H E

2000-01-01

48

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

Science.gov (United States)

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

Pfister, Hans

2014-05-01

49

Two types of photomultiplier voltage dividers for high and changing count rates  

International Nuclear Information System (INIS)

We report on the design of two types of voltage distribution circuits for high stability photomultiplier operation. 'Type A' voltage divider is an ohmic voltage divider with high bleeder current (up to 10 mA) and the resistor chain split at one of the last dynodes, usually the dynode where the analog signal is derived from. This simple constructive measure improves the stability of the dynode voltage by a factor of 5 compared with an unsplit conventional resistor chain. 'Type B' is a novel active voltage divider using cold cathode tubes ar regulating elements. This voltage divider exhibits excellent temperature stability (about 10-4/0C). With 'type B' an equal stability compared with conventional ohmic dividers can be achieved at a bleeder current smaller by one order of magnitude. Of course both concepts, 'type A' and 'type B', can be combined. (orig.)

50

Divided executives and democratisation  

OpenAIRE

This article examines the effect of a divided executive on democratisation in mixed systems where presidents are directly elected and prime ministers are responsible to the legislature. A divided executive is where the president and prime minister are not from the same party. The importance of a divided executive is hypothesised to vary according to the relative powers of the president and prime minister. In mixed systems where either the president or the prime minister is the dominant act...

Elgie, Robert; Mcmenamin, Iain

2006-01-01

51

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

52

¿Agua dividida, agua compartida? Acuiferos transfronterizos en Sudamérica, una aproximación / Divided Water, Shared Water? An Approach to Cross-border Aquifers in South America  

Scientific Electronic Library Online (English)

Full Text Available SciELO Colombia | Language: Spanish Abstract in spanish Este artículo aborda la política fronteriza del agua en Sudamérica, con una discusión específica sobre la frontera Colombia-Venezuela. Con una perspectiva comparativa, la autora aborda el impacto de los procesos políticos en la distribución y acceso al agua en regiones fronterizas. La autora señala [...] que la internacionalización del manejo del agua en zonas fronterizas debilita la participación pública debido al limitado conocimiento de la agenda ambiental de los macro esfuerzos regionales como la Comunidad Andina y sus instituciones. Los ríos o acuíferos compartidos son recursos ''invisibles'' para el común de los ciudadanos en Sudamérica, que pueden convertirse en fuente potencial de conflictos o de cooperación e integración regional. La cooperación es definitivamente necesaria en estos casos. Pocos esfuerzos se han registrado recientemente en Latinoamérica. Entre estos, destaca el programa Acuíferos Transfronterizos de las Américas (ISARM en Inglés), creado en 2002 por la UNESCO. Es particularmente importante poner atención en la falta de acuerdos trasnacionales sobre acuíferos transfronterizos en Sudamérica para compartir responsabilidades y toma de decisiones sobre el manejo de estas aguas. La autora señala el caso particular del acuífero transfronterizo Cúcuta-San Antonio sin un aparente manejo binacional entre Colombia y Venezuela. Abstract in english This article focuses on border water politics in South America with specific discussion of the Colombia-Venezuela Border. Through a comparative perspective, the author analyzes the impact of political decision-making on water access and distribution in border contexts. The author argues that the int [...] ernationalization of water management in these border regions weakens public participation due to limited public knowledge of the environmental agendas of regional organizations, such as the Andean Community and its institutions. Shared driver basins or aquifers are invisible resources for all citizens in South America which can be transformed into potential sources of conflict or cooperation and regional integration. Cooperation is definitely necessary in these cases. A few efforts have been noted recently in Latin America. Amongst them is one by conducted by UNESCO called ISARM (International Shared Aquifer Resource Management), created in 2002. It is particularly important to place attention on the lack of transnational agreements on South American water borders on the sharing of responsibilities, decisions and the management of transboundary waters. The author highlights the case of the Cúcuta-San Antonio aquifer between Colombia and Venezuela, which lacks clear bi-national management.

Carmen, Maganda.

2008-06-01

53

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

54

Dynamic Systems Model for Filamentary Mem-Resistors  

OpenAIRE

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

Mouttet, Blaise

2011-01-01

55

Experimental Research on Properties of Materials of Grounding Resistor  

OpenAIRE

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

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

2013-01-01

56

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

International Nuclear Information System (INIS)

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

57

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

CERN Document Server

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

Kolek, A; Dziedzic, A

2003-01-01

58

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

Science.gov (United States)

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

Pfister, Hans

2014-01-01

59

An integrated power divider implemented in GaAs technology  

Science.gov (United States)

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

Zebao, Du; Hao, Yang; Haiying, Zhang; Min, Zhu

2014-04-01

60

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

61

Experimental study of Evanohm thin film resistors at subkelvin temperatures  

International Nuclear Information System (INIS)

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

62

TI--CR--AL--O thin film resistors  

Science.gov (United States)

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

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

2000-01-01

63

Electrochemical Migration on Electronic Chip Resistors in Chloride Environments  

DEFF Research Database (Denmark)

Electrochemical migration behavior of end terminals on ceramic chip resistors (CCRs) was studied using a novel experimental setup in varying sodium chloride concentrations from 0 to 1000 ppm. The chip resistor used for the investigation was 10-k? CCR size 0805 with end terminals made of 97Sn3Pb alloy. Anodic polarization behavior of the electrode materials was investigated using a microelectrochemical setup. Material makeup of the chip resistor was investigated using scanning electron microscopy (SEM)/energy dispersive spectroscopy and focused-ion-beam SEM. Results showed that the dissolution rate of the Sn and stability of Sn ions in the solution layer play a significant role in the formation of dendrites, which is controlled by chloride concentration and potential bias. Morphology, composition, and resistance of the dendrites were dependent on chloride concentration and potential.

Minzari, Daniel; Jellesen, Morten Stendahl

2009-01-01

64

Surface scattering mechanisms of tantalum nitride thin film resistor  

OpenAIRE

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

Chen, Huey-ru; Chen, Ying-chung; Chang, Ting-chang; Chang, Kuan-chang; Tsai, Tsung-ming; Chu, Tian-jian; Shih, Chih-cheng; Chuang, Nai-chuan; Wang, Kao-yuan

2014-01-01

65

The characterization of thick-film resistors on different substrates  

International Nuclear Information System (INIS)

Thick film resistors (2041, 10 kohm/sq, Du Pont) that were developed for firing on alumina substrates have been evaluated in terms of their compatibility with ZrO2 and with dielectric-covered stainless-steel substrates. Possible interactions between the dielectric materials and the steel were investigated with scanning electron microscopy and with energy dispersive X-ray analysis. Sheet resistivities, temperature coefficients of resistivity, current noise and gauge factors were measured. The results indicate that the evaluated thick-film resistors are compatible with zirconia ceramics and dielectric-on-steel substrates. (author)

66

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

67

Resistor Loaded EBG Surfaces for Slot Antenna Design  

Directory of Open Access Journals (Sweden)

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

Shenyi Cao

2013-07-01

68

Ruthenium oxide resistors as sensitive elements of composite bolometers  

International Nuclear Information System (INIS)

Bolometers for particle detection made with Ruthenium oxide thermistors could be produced by means of a simple technique on a variety of different materials as substrata. Preliminary results on alpha particle detection with devices realized using commercial RuO2 thick film resistor (Tfr) are considered positive for devices operating between. 3 and .1 k and determined us to pursue further the idea. Ruthenium oxide resistors on sapphire at the moment are being prepared. The behaviour of these devices st temperatures lower than .1 k has to be investigated in more detail

69

Ti-Cr-Al-O Thin Film Resistors  

Energy Technology Data Exchange (ETDEWEB)

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

Jankowski, A F; Hayes, J P

2002-03-21

70

Electrostatic Discharge (ESD) Failures in Thin Film Resistors  

Science.gov (United States)

Field failures of nichrome thin film resistors have been investigated recently for several pieces of space flight hardware. These failures have involved resistance shifts ranging from a few percent to complete open circuits. Failure analysis and duplication of these failures have revealed that the failures were caused by electrostatic discharge. The failure characteristics and the circuit conditions necessary for failure have been studied for several types of thin film resistors including nichrome and tantalum nitride resistive elements. The effects of latent damage and resistive pattern design will also be discussed.

Hull, Scott M.

1999-01-01

71

Monitoring the Digital Divide  

CERN Document Server

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

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

2003-01-01

72

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. PMID:25362455

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

2014-10-01

73

Air-cooled fast discharge resistors for ITER magnets  

Energy Technology Data Exchange (ETDEWEB)

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

Tanchuk, Victor, E-mail: tanchuv@sintez.niiefa.spb.su [D.V. Efremov SRIEA, 3 Doroga na Metallostroy, RUS-196641 St. Petersburg (Russian Federation); Grigoriev, Sergey; Lokiev, Vladimir; Roshal, Alexander [D.V. Efremov SRIEA, 3 Doroga na Metallostroy, RUS-196641 St. Petersburg (Russian Federation); Song, Inho [ITER Organization, CS 90 046, 13067 St. Paul lez Durance Cedex (France); Buzykin, Oleg [CAE-Services, 107497 Moscow (Russian Federation)

2011-10-15

74

Frequency dependence of resistive component of impedance of silicon thin-film resistors  

Energy Technology Data Exchange (ETDEWEB)

A high-value resistor based on silicon thin film is described whose noise and frequency characteristics considerably surpass those of manufactured resistors. The frequency dependence of the resistive component of impedance is studied to determine the noise and frequency characteristics of the silicon thin-film resistors. The results permit calculation of the energy equivalent of the noise of resistors in nuclear-radiation detection units at any temperature from their frequency characteristic at room temperature.

Belogurov, S.V.; Gostilo, V.V.; Yurov, A.S.

1988-02-01

75

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

76

Monitoring the digital divide  

International Nuclear Information System (INIS)

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

77

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

International Nuclear Information System (INIS)

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

78

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

79

Spin dependent trapping in a polycrystalline silicon integrated circuit resistor  

International Nuclear Information System (INIS)

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

80

Electrical Switching of Perovskite Thin-Film Resistors  

Science.gov (United States)

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

Liu, Shangqing; Wu, Juan; Ignatiev, Alex

2010-01-01

81

An automated resistor network to inspect the linearity of resistance-thermometry measurements  

International Nuclear Information System (INIS)

This note describes a resistor network that enables automated linearity checks of resistance-thermometry measurements. The network is made in such a manner that the voltages across any number of resistors in a resistor series are read to get separate four-terminal values interrelated by the formula for the series connection. Linearity tests of resistance bridges show that the network can resolve deviations from linearity down to ±20 ?? for resistance measurements from 32 to 284 ?. (technical design note)

82

Testing method for measuring corrosion resistance of surface mount chip resistors  

OpenAIRE

Surface mount chip resistors are amongst the simplest and most inexpensive of all components used in electronic circuits and systems. Typically, resistor failure modes include open circuits, resistive shorts or variations in resistance indicating parametric drift or intermittent failure, which in some applications result in overall system failure. Corrosion is currently believed to be the number one failure mechanism for chip resistors deployed in developing markets such as Centra...

Reid, M.; Collins, Maurice N.; Dalton, Eric D.; Punch, Jeff; Tanner, D. A.

2012-01-01

83

Simple LabVIEW DC Circuit Simulation With Series Resistors: Overview  

Science.gov (United States)

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

84

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

85

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

OpenAIRE

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

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

2014-01-01

86

Superconductive tunneling junction resistor and method of fabrication  

International Nuclear Information System (INIS)

A superconductive junction device for fabricating Josephson integrated circuits is useful for replacing deposited thin-film resistors. Derived by ''poisoning'' a superconductive electrode of the Josephson junction, the device displays controllable resistive properties at normal superconducting transition temperatures at substantial savings in the space occupied. Methods of fabricating the device using the selective niobium anodization process and conventional lead alloy processes are disclosed. When both upper and lower superconductive electrodes are poisoned, the device has linear properties whose resistance is identical to the normal resistance of unpoisoned junctions

87

Carbon dioxide response of semiconducting oxide gas sensitive resistors  

International Nuclear Information System (INIS)

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

88

Gentilly 2 divider plate replacement  

International Nuclear Information System (INIS)

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

89

Simple LabVIEW DC Circuit Simulation With Parallel Resistors: Overview  

Science.gov (United States)

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

90

An optimized resistor pattern for temperature gradient control in microfluidics  

International Nuclear Information System (INIS)

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

91

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

Science.gov (United States)

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

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

2014-11-01

92

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

International Nuclear Information System (INIS)

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.

93

Implanted Silicon Resistor Layers for Efficient Terahertz Absorption  

Science.gov (United States)

Broadband absorption structures are an essential component of large format bolometer arrays for imaging GHz and THz radiation. We have measured electrical and optical properties of implanted silicon resistor layers designed to be suitable for these absorbers. Implanted resistors offer a low-film-stress, buried absorber that is robust to longterm aging, temperature, and subsequent metals processing. Such an absorber layer is readily integrated with superconducting integrated circuits and standard micromachining as demonstrated by the SCUBA II array built by ROE/NIST (1). We present a complete characterization of these layers, demonstrating frequency regimes in which different recipes will be suitable for absorbers. Single layer thin film coatings have been demonstrated as effective absorbers at certain wavelengths including semimetal (2,3), thin metal (4), and patterned metal films (5,6). Astronomical instrument examples include the SHARC II instrument is imaging the submillimeter band using passivated Bi semimetal films and the HAWC instrument for SOFIA, which employs ultrathin metal films to span 1-3 THz. Patterned metal films on spiderweb bolometers have also been proposed for broadband detection. In each case, the absorber structure matches the impedance of free space for optimal absorption in the detector configuration (typically 157 Ohms per square for high absorption with a single or 377 Ohms per square in a resonant cavity or quarter wave backshort). Resonant structures with -20% bandwidth coupled to bolometers are also under development; stacks of such structures may take advantage of instruments imaging over a wide band. Each technique may enable effective absorbers in imagers. However, thin films tend to age, degrade or change during further processing, can be difficult to reproduce, and often exhibit an intrinsic granularity that creates complicated frequency dependence at THz frequencies. Thick metal films are more robust but the requirement for patterning can limit their absorption at THz frequencies and their heat capacity can be high. patterned absorber structures that offer low heat capacity, absence of aging, and uniform, predictable behavior at THz frequencies. We have correlated DC electrical and THz optical measurements of a series of implanted layers and studied their frequency dependence of optical absorption from .3 to 10 THz at cryogenic temperatures. We have modeled the optical response to determine the suitability of the implanted silicon resistor as a function of resistance in the range 10 Ohms/sq to 300 Ohms/sq.

Chervenak, J. A.; Abrahams, J.; Allen, C. A.; Benford, D. J.; Henry, R.; Stevenson, T.; Wollack, E.; Moseley, S. H.

2005-01-01

94

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

95

A novel charge sensitive preamplifier without the feedback resistor  

International Nuclear Information System (INIS)

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

96

Uncertainty quantification for electrical impedance tomography with resistor networks  

CERN Document Server

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

Borcea, Liliana; Mamonov, Alexander V

2011-01-01

97

Voltage controlled resistor using quasi-floating-gate MOSFETs  

Directory of Open Access Journals (Sweden)

Full Text Available A voltage controlled resistor (VCR using quasi-floating-gate MOSFETs (QFGMOS suitable for low voltage applications is presented. The performance of the VCR implemented with QFGMOS is compared with its floating-gate MOSFET (FGMOS version. It was found that QFGMOS offers better performance than FGMOS in terms of frequency response, offsets and chip area. The VCR using QFGMOS offers high bandwidth and low power dissipation and yields high value of resistance as compared to its FGMOS counterpart. The workability of the presented circuits was tested by PSpice simulations using level 3 parameters of 0.5?m CMOS technology with supply voltage of ± 0.75V. The simulations results were found to be in accordance with the theoretical predictions.

Susheel Sharma

2013-01-01

98

The exact evaluation of the corner-to-corner resistance of an M × N resistor network: asymptotic expansion  

OpenAIRE

We study the corner-to-corner resistance of an M ×N resistor network with resistors r and s in the two spatial directions, and obtain an asymptotic expansion of its exact expression for large M and N.

Essam, John

2009-01-01

99

Indium Tin Oxide Resistor-Based Nitric Oxide Microsensors  

Science.gov (United States)

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

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

2012-01-01

100

Influences of additives on the electrical properties of lead-free thick film resistors  

International Nuclear Information System (INIS)

Lead-free thick film resistors were prepared by mixing of ruthenium oxide (RuO2) and K2O-CaO-B2O3-SiO2 glass. Sheet resistivities of the thick film resistors prepared with different RuO2/glass ratios in this study were in the range between 0.2 and 100 k?/sq. When RuO2/glass volume ration equaled to 15/85, the sheet resistivity of the resistor was about 1.52 k?/sq. It had temperature coefficient of resistance (TCR) value of 523 ppm/oC. Five metal oxides, such as Nb2O5, MnO2, MoO3, TiO2 and Fe2O3 were used as TCR adjustment agents. Resistivities of the resistor films increased with increasing Nb2O5 contents. The resistivities, however, decreased with increasing Fe2O3 and MnO2 contents. For 15 vol% RuO2 thick film resistor, the TCR value of the resistor became negative, when 4 wt% NB2O3 or MnO2 was added to the glass flint. Additive of MoO3 did not have much influence on the resistivity and TCR value. Both resistivity and TCR value of the resistor decreased with increasing Fe2O3 content. (author)

101

Electrical properties and conduction mechanisms of Ru-based thick-film (cermet) resistors  

International Nuclear Information System (INIS)

This paper presents an experimental study of the electrical conduction mechanisms in thick-film (cermet) resistor. The resistors were made from one custom and three commercially formulated inks with sheet resistivities ranging from 102 to 106 ?/D7Alembertian in decade increments. Their microstructure and composition have been examined using optical and scanning electron microscopy, electron microprobe analysis, x-ray diffraction, and various chemical analyses. This portion of our study shows that the resistors are heterogeneous mixtures of metallic metal oxide particles (approx.4 x 10-5 cm in diameter) and a lead silicate glass. The metal oxide particles are ruthenium containing pyrochlores, and are joined to form a continuous three-dimensional network of chain segments. The principal experimental work reported here is an extensive study of the electrical transport properties of the resistors. The temperature dependence of conductance has been measured from 1.2 to 400 K, and two features common to all resistors are found. There is a pronounced decrease in conductance at low temperatures and a shallow maximum at several hundred Kelvin. Within the same range of temperatures the reversible conductance as a function of electric field from 0 to 28 kV/cm has been studied. The resistors are non-Ohmic at all temperatures, but particularly at cryogenic temperatures for low fields. At higher fields the conductance shows a linear variields the conductance shows a linear variation with electric field. The thick-film resistors are found to have a small dielectric constant and a (nearly) frequency-independent conductance from dc to 50 MHz. The magnetoresistance to 100 kG, the Hall mobility, and the Seebeck coefficient of most of the resistors have been measured and discovered to be quite small. Many of the electrical transport properties have also been determined for the metal oxide particles which were extracted from the fired resistors

102

How Do You Divide Fractions?  

Science.gov (United States)

This five-minute video answers the question "Must one always invert and multiply?" when dividing fractions. An alternative algorithm is presented which works well in certain cases. The video focuses on sense making in using either method, and on judging the reasonableness of answers.

2011-01-01

103

Resistor development for N.E.C. accelerators  

International Nuclear Information System (INIS)

This paper reports on a resistor development program started because of problems that have shown themselves over a period of years with corona points. The main problem found after using corona points for fifteen years is the long term problem associated with corrosive SF6 breakdown products. The program identified that SF6 breakdown, in concentrations of 0.1 ppm caused by corona points, were sufficient to kill the nylon in a chain in several hundred hours. The problem is held in check, but not eliminated. The corrosive products generated by the corona points are not confined to the gas phase where they start, but cause corrosion of all metal and plastic surfaces on which they land. So inside the machine there is a continuous generation of particulates. These particulates are fundamentally incompatible with the operation of the high voltage accelerator. The other thing discovered about corona points is that it is very difficult to control them in such a way that the voltages across successive points in the assembly are all equal

104

Method of calculation of thin-film resistor electrode’s impedance  

Directory of Open Access Journals (Sweden)

Full Text Available The physical and mathematical models of electrode impedance for the thin-film resistors of rectangular and interdigital shapes are presented in this work. The impact of electrode impedance on the manufacturing and temperature errors is estimated.

Spirin V. G.

2009-11-01

105

Conductivity modulation effects in diffused resistors at very high dose rate levels  

International Nuclear Information System (INIS)

Integrated circuits are susceptible to burnout at extremely high dose rate levels. Several IC technologies utilize diffused resistors which are subject to conductivity modulation. These resistors, in some cases, may not provide sufficient current limiting at high dose rate levels to preclude burnout. One solution to this problem is to utilize thin film or thick film resistors, e.g., Nichrome, to provide current limiting. Another solution is one to use diffused resistors in dielectrically isolated tubs. To facilitate this solution, engineering expressions which accurately define conductivity modulation must be developed, and the current limiting which results must be adequately estimated. The problem was previously addressed and this study extends the treatment by considering band-to-band recombination which is the most important basic effect limiting conductivity modulation at high dose rate levels

106

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

107

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

OpenAIRE

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

Mucunguzi-rugwebe, Ericam R. R.; Michael Josiah Mangala

2013-01-01

108

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

Directory of Open Access Journals (Sweden)

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

Ericam R.R. Mucunguzi-Rugwebe

2013-09-01

109

TryEngineering: Using Ohm’s Law to Build a Voltage Divider  

Science.gov (United States)

In this high school lab, students design and build one of the basic circuits of electrical engineering: the voltage divider -- a form of linear circuit capable of producing a wide range of output voltages. The lesson provides scaffolding as students explore the mathematical relationships of parallel and series resistors as they build light emitting diodes. The driving question of the lesson: How do electrical engineers apply Ohm's law in the design of electrical circuits? This lesson provides educators with comprehensive supplemental material, including step-by-step breadboard instructions and matrices of possible voltage outputs. For additional student practice, see Related Materials to download an editor-recommended worksheet on voltage divider electronics (37 problems with answers provided). This resource is part of a collection maintained by the Institute of Electrical and Electronics Engineers (IEEE).

2012-07-30

110

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)

111

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

112

Use of design of experiments techniques to investigate resistance change of chip resistors in MESSENGER  

Science.gov (United States)

A 2 5 full factorial designed experiment was performed in order to investigate the cause of the increase in resistance of various precision resistors used in the MESSENGER spacecraft. Even though the largest increase was less than 5 %, it was troubling because the cause of the resistance change had not been determined other than the usual suspects of ESD, solder tip temperature, environmental stress screening (ESS) or corrosion (disputed by the commercial manufacturer). Because of the need to quickly resolve the root cause of this change, it was decided to study all the variables simultaneously by the use of Design of Experiments (DOE). The five variables studied were the different resistor types, operating voltages, solder tip temperatures, temperature cycling, and the highly accelerated stress test (HAST). The statistically significant findings are: 1) The most probable cause of the increase in resistance is moisture ingress through the old passivation layer inherent with only one chip resistor type. The old passivation coating is not as impervious to moisture as the new passivation coating on the other resistor type. The failure mechanism is therefore a chemical reaction, most probably the oxidation of chromium present in the nichrome resistor element to form a non-conductive chromium sub-oxide. 2) To a much less significant extent, the higher solder tip temperature of 700 F and the higher test voltage (e.g. 40 volts) contribute to a higher resistance change. Materials analyses of the coatings explain the difference in moisture permeation rates.

Uy, Manny; Hardesty, Ronald, Jr.; Fogle, Johnny; Moor, Andrew

2006-08-01

113

A Biased Resistor Network Model for Electromigration Phenomena in Metallic Lines  

CERN Document Server

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

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

2004-01-01

114

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

CERN Document Server

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

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

1998-01-01

115

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

Science.gov (United States)

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

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

2001-01-01

116

Gauge factor of thick film resistors outcomes of the variable range hopping model  

CERN Document Server

Despite a large amount of data and numerous theoretical proposals, the microscopic mechanism of transport in thick film resistors remains unclear. However, recent low temperature measurements point toward a possible variable range hopping mechanism of transport. Here we examine how such a mechanism affects the gauge factor of thick film resistors. We find that at sufficiently low temperatures $T$, for which the resistivity follows the Mott's law $R(T)\\sim \\exp(T_0/T)^{1/4}$, the gauge factor GF is proportional to $(T_0/T)^{1/4}$. Moreover, the inclusion of Coulomb gap effects leads to ${\\rm GF}\\sim (T_0'/T)^{1/2}$ at lower temperatures. In addition, we study a simple model which generalizes the variable range hopping mechanism by taking into account the finite mean inter-grain spacing. Our results suggest a possible experimental verification of the validity of the variable range hopping in thick film resistors.

Grimaldi, C; Strässler, S

2000-01-01

117

Split-cross-bridge resistor for testing for proper fabrication of integrated circuits  

Science.gov (United States)

An electrical testing structure and method is described whereby a test structure is fabricated on a large scale integrated circuit wafer along with the circuit components and has a van der Pauw cross resistor in conjunction with a bridge resistor and a split bridge resistor, the latter having two channels each a line width wide, corresponding to the line width of the wafer circuit components, and with the two channels separated by a space equal to the line spacing of the wafer circuit components. The testing structure has associated voltage and current contact pads arranged in a two by four array for conveniently passing currents through the test structure and measuring voltages at appropriate points to calculate the sheet resistance, line width, line spacing, and line pitch of the circuit components on the wafer electrically.

Buehler, M. G. (inventor)

1985-01-01

118

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)

119

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

120

Anode dependence of set voltage in resistive switching of metal/HfO2/metal resistors  

Science.gov (United States)

The anode dependence of set voltage in resistive switching behaviors of metal/HfO2/metal resistors is investigated by applying positive and negative voltage polarity, and by changing the location of the electrodes made of various metals including Al, Pt, Mo, and Ru. When the same anode is applied to resistors whatever cathodes are, their set voltages in high resistance state are very similar. The strong anode dependence on set voltage is related to the potential near the anode domain owing to the partial rupture of the conducting filament. This rupture of filaments makes the thick insulator film thinner with a small potential barrier.

Park, In-Sung; Jung, Yong Chan; Ahn, Jinho

2014-12-01

121

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.

122

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

123

Divided power structures and chain complexes  

OpenAIRE

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

124

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

125

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

126

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

International Nuclear Information System (INIS)

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

127

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

CERN Document Server

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

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

2013-01-01

128

Construction of the JFT-2M Tokamak(3) --- development of semiconductor shunt resistor ---  

International Nuclear Information System (INIS)

A new type of toroidal shunt (by-pass) resistors have been successfully developed for the JFT-2M vacuum vessel. Since the vacuum vessel is electrically insulated at two toroidal positions with organic insulators, in-vacuum shunt resistors are required in order to prevent arc discharge at the insulated vessel joint and to protect the in-vessel magnetic probes and the poloidal field (PF) coils in case of plasma disruptions or misfire. Approximately 10 m? toroidal resistance is necessary based on the PF coils and power supply design conditions. For the resistors, metals can not be used because of their higher electric conductivity and small heat capability, and finally newly developed SiC ceramic has been chosen due to its moderate electric conductivity, high thermal conductivity and sufficient mechanical strength. Fifty-two cylindrical SiC pieces are built in the fastening bolts for each of the insulated vessel joints. The SiC ceramic used here has Zennercharacteristics, i.e., its conductivity rapidly decreases with the increment of applied voltage, thus it presents preferable performances in terms of providing a high toroidal resistance at plasma start-up and a lower one at disruptive plasma behavior. The plasma operation of about 4900 discharges performed so far has shown the effectiveness and applicability of this type of shunt resistors. This work has been done under the contract from JAERI and provided with a number of useful advices and suggestions by JAERI membeul advices and suggestions by JAERI members

129

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

International Nuclear Information System (INIS)

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

130

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

131

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

Science.gov (United States)

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

Kamata, Masahiro; Abe, Mayumi

2012-01-01

132

30 CFR 77.802 - Protection of high-voltage circuits; neutral grounding resistors; disconnecting devices.  

Science.gov (United States)

...Surface High-Voltage Distribution § 77.802 Protection...resistor at the source transformers, and a grounding circuit...extend along with the power conductors and serve...high-voltage equipment supplied power from that circuit...observation that the power is...

2010-07-01

133

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

134

Measurement of small ion beams by thermal ionisation mass spectrometry using new 1013 Ohm resistors  

International Nuclear Information System (INIS)

Highlights: • First data are presented using 1013 Ohm resistors connected to Faraday collectors. • 5 prototype 1013 Ohm resistors were installed in a TRITON-Plus TIMS. • Performance was tested by measuring Sr and Nd isotope ratios on?13 Ohm resistors perform better than ion counting and 1011 Ohm resistors. • Fourth decimal variability can be resolved for Nd isotope ratios on 10 pg samples. - Abstract: We tested 5 newly manufactured – prototype – 1013 Ohm resistors in the feedback loop of Faraday cup amplifiers to measure small ion beams by Thermal Ionisation Mass Spectrometry (TIMS). The high Ohmic resistors installed in the TRITON Plus at the VU University Amsterdam theoretically have 10 times lower noise levels relative to the default 1011 Ohm resistors. To investigate the precision and accuracy of analyses using these new amplifiers we measured Sr and Nd isotopes of reference standards at a range of ion currents (3.2 × 10?16 to 1 × 10?12 A, corresponding to intensities of 32 ?V to 100 mV on a default 1011 Ohm amplifier) and on small amounts of material (100 and 10 pg). Internal precision and external reproducibility for Sr and Nd isotope ratios are both better when collected on 1013 compared 1012 Ohm resistors and to the default 1011 Ohm resistors. At an 87Sr ion current of 3 × 10?14 A (3 mV on a 1011 Ohm amplifier) the internal precision (2?SE) of 87Sr/86Sr is 5 times better for 1013 Ohm resistors compared to 1011 Ohm resistors. The external reproducibility (2?SD) at this beam intensity is 9 times better. Multiple 100 and 10 pg Sr standards, ran to exhaustion, yielded low 87Sr/86Sr compared to the long term average (e.g. 10 pg average = 0.710083 ± 164 (n = 11) instead of 0.710244 ± 12, n = 73). The average off-set for 10 pg standards can be explained by a loading blank contribution of 1.3 pg. In contrast, Nd data on 100 pg and 10 pg samples are accurate suggesting that Nd loading blanks do not compromise the data. The external reproducibility of 143Nd/144Nd on 100 pg samples is 125 ppm and 3.3‰ on 10 pg samples (2?RSD = relative standard deviation, n = 10). Thus, variability in Nd and Sr isotope ratios in the 4th decimal place, e.g. 143Nd/144Nd 0.5110–0.5119 or 87Sr/86Sr 0.7100–0.7109, can be resolved in 10 to 100 pg samples provided that the procedural blanks and chemical separation are optimal. For measurements in the beam intensity range usually covered by ion counting (5 cps) we obtain a 143Nd/144Nd internal precision (2?SE) of 480 ppm for a 143Nd intensity of 6.25 × 104 cps (1 mV) and 1% at an intensity of 2 × 103 cps (32 ?V on a 1011 Ohm amplifier). We find that at intensities higher than 2 × 104 cps the precision using the 1013 Ohm resistors is better than for ion counting owing to instability and non-linearity behaviour of the ion counting system. Our results indicate that between 2 × 104 cps and an ion current of 2 × 10?13 A (20 mV on a 1011 Ohm amplifier) it is beneficial to use the high gain amplifiers instead of (multi) ion counting or Faraday cups equipped with the standard 1011 Ohm resistors. This finding suggests that the newly developed high gain resistors could potentially be valuable in applications that currently use (multiple) ion counting to measure small ion beams (e.g. U-series, Re-Os, Pu, Pb). In addition to improved precision, the use of Faraday cups equipped with high resistance amplifiers is more practical in terms of the required calibration procedure and in the flexibility in the collector set-up compared to using multiple ion counting arrays

135

Quasi-Random Resistor Network Model for Linear Magnetoresistance of Metal–Semiconductor Composite  

International Nuclear Information System (INIS)

A new model for the linear magentoresistance (MR) of the Ag2+?Se and Ag2+?Te thin films is proposed. The thin him is considered as a metal-semiconductor composite and dispersed into an N – N quasi-random resistor network. The network is constructed from four-terminal resistors and the mobility of carries ? within the network has a quasi-random distribution, i.e. a Gaussian distribution with two constraint conditions. The model predicts that the MR increases with the increasing magnetic fields, and increases linearly at high field. Moreover, the MR decreases with the increasing temperatures. A good agreement between the theoretical MR and the available experimental data is found. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

136

Nanoporous carbon tunable resistor/transistor and methods of production thereof  

Science.gov (United States)

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

137

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)

138

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

139

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

Science.gov (United States)

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

Tan, Zhi-Zhong

2015-02-01

140

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

International Nuclear Information System (INIS)

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

141

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)

142

Water Homeostasis: Evolutionary Medicine  

OpenAIRE

As a major component of homeostasis, all organisms regulate the water composition of various compartments. Through the selective use of barrier membranes and surface glycoproteins, as well as aquaporin water channels, organisms ranging from Archaebacteria to humans can vary water permeabilities across their cell membranes by 4 to 5 orders of magnitude. In barrier epithelia the outer, or exofacial, leaflet acts as the main resistor to water flow; this leaflet restricts water flow by minimizing...

Zeidel, Mark L.

2012-01-01

143

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

OpenAIRE

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 ...

Engheta, Nader; Salandrino, Alessandro; Alu, Andrea

2004-01-01

144

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

145

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

OpenAIRE

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

146

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

OpenAIRE

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

147

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

148

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

Science.gov (United States)

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

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

2005-05-01

149

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

International Nuclear Information System (INIS)

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

150

Transonic divider for gas chromatograph effluents  

Science.gov (United States)

Transonic effluent divider system was developed which permits varying mass input of gas chromatographic effluent into mass spectrometer without affecting performance of gas chromatograph. Mechanisms of operation are described.

Wellman, J. B.

1972-01-01

151

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 needvider 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)

152

Implementation of Non Restoring Interval Divider unit  

Directory of Open Access Journals (Sweden)

Full Text Available Interval arithmetic provides a general methodology for bounding errors. Interval arithmetic provides reliability and accuracy by computing a lower and upper bound in which each result is guaranteed to reside. An interval’s width ensures the maximum possible error. The approaches consisted on developing hardware support for interval arithmetic division unit by incorporating existing conventional floating point units. This unit requires slightly more area than a conventional floating point divider. It provides a significant performance improvement over software implementations of interval divider. This paper presents the implementation of non restoring interval division algorithm for double precision binary data.

Milind R. Patel, Prof. Deepali H. Shah

2012-02-01

153

Annealing effect on the electrical properties and microstructure of embedded Ni-Cr thin film resistor  

Energy Technology Data Exchange (ETDEWEB)

Highlights: Black-Right-Pointing-Pointer Annealing effect on the properties of embedded Ni-Cr thin film resistor. Black-Right-Pointing-Pointer A good annealing condition was achieved. Black-Right-Pointing-Pointer The rarely observed hexagonal Ni (0 1 1), (0 0 2) and (1 0 3) were found. Black-Right-Pointing-Pointer The segregation of chromium in thin film can affect the resistivity and TCR. Black-Right-Pointing-Pointer The results obtained would be helpful in achieving a good embedded resistor. - Abstract: Ni-Cr (80/20 at.%) alloy was deposited on the copper foil substrate as embedded thin film resistor (ETFR) materials by DC magnetron sputtering method. Electrical properties and microstructure of Ni-Cr ETFR under different annealing conditions were investigated. Results indicated that the ETFR exhibited the smallest temperature coefficient of resistance (TCR) after annealing at 250 Degree-Sign C for 540 s in N{sub 2}. The structure, stress, composition and surface morphology of ETFR materials were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), energy dispersive spectroscopy (EDS) and atomic force microscopy (AFM). The rarely reported hexagonal Ni (0 1 1), (0 0 2) and (1 0 3) in Ni-Cr thin film were found in Ni-Cr (80/20 at.%) ETFR materials. The chemical states on the surface of the ETFR materials after annealing were mainly Cr{sub 2}O{sub 3}. The segregation of chromium during annealing can affect the resistivity and temperature coefficient of resistance (TCR). The different surface morphology of ETFR in annealing will affect the resistivity.

Lai Lifei [Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055 (China); Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); NingBo University of Technology, Ningbo 315016 (China); Zeng Wenjin; Fu Xianzhu [Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055 (China); Sun Rong, E-mail: rong.sun@siat.ac.cn [Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055 (China); Du Ruxu [Chinese University of Hong Kong, Shatin, Hong Kong (Hong Kong)

2012-10-15

154

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

155

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

156

Static Current-Voltage Characteristics of Silicon n+-i-n+ Resistors at Liquid Helium Temperatures  

OpenAIRE

The behaviour of the (I-V) characteristics is investigated in n+-i-n+ highly compensated Si resistors at temperatures 4.2-45K. The conduction mechanisms are discussed in detail here. The prebreakdown and breakdown regions of I-V characteristics were simulated by a one-dimensional model including the evidence of impurity high compensation and freeze out effects as well as the shallow-dopants impact ionisation by the injected hot carriers into the base. Negative resistance (S-type) phenomena ar...

Tsamakis, D.; Glezos, N.

1996-01-01

157

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

158

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

159

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

160

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

International Nuclear Information System (INIS)

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

161

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

162

Crossing Divides: The Legacy of Graham Nuthall  

Science.gov (United States)

Graham Nuthall's work cuts across methodological and conceptual divides that have worked against the development of a theory of learning and teaching that is at once predictive and practical. The micro-genetic approach to research on learning in classrooms that he developed with Adrienne Alton-Lee successfully transcends the unhelpful dichotomy…

Davis, Alan

2006-01-01

163

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

164

Computing ULV Decomposition by Divide Conquer Method  

Directory of Open Access Journals (Sweden)

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

Hasan Erbay

2005-01-01

165

Divide and Multiply: Baptist Diversity in Appalachia.  

Science.gov (United States)

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

Dorgan, Howard

1996-01-01

166

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

167

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

International Nuclear Information System (INIS)

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

168

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

Science.gov (United States)

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

Olszacki, M.; Maj, C.; Bahri, M. Al; Marrot, J.-C.; Boukabache, A.; Pons, P.; Napieralski, A.

2010-06-01

169

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

170

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

Science.gov (United States)

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

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

2012-04-01

171

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

Science.gov (United States)

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

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

2014-12-01

172

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

International Nuclear Information System (INIS)

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

173

SiMPl—An avalanche diode array with bulk integrated quench resistors for single photon detection  

Science.gov (United States)

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

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

2010-05-01

174

Performance characteristics of thin film resistor arrays for infrared projector applications  

Science.gov (United States)

The thin film resistor array choice of infrared projector technology is characterized by the comparatively large values of pixel fill factor and emissivity that can be attained but is limited by materials and heat transfer constraints. In this paper, the characteristics and limitations of an infrared projector test device based on a 2 X 25 bilinear thin film nichrome resistor array are described. The steady state and transient performance characteristics have each been assessed by use of both analytical and finite element heat transfer techniques. Test devices based on the design that gave the best predicted performance have been fabricated on a silicon wafer substrate by application of the conventional techniques of photolithography, etching and vacuum deposition, each array being comprised of a patterned polyimide insulation layer sandwiched between the substrate and the nichrome heating elements. Initial characterization experiments have demonstrated a 200 degree(s)C operating temperature capability and 10 - 90% rise and fall times of the order of 100 - 200 microsecond(s) . It is shown that the risetime can be improved significantly by application of a tailored drive voltage waveform, as can the falltime of appropriate thermal connection of the substrate to a low temperature heat sink. Modes of device failure are also discussed.

Williams, Owen M.; Reeves, Geoffrey K.; Ong, Gim T.

1992-09-01

175

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

176

Power divider of the MP 10  

International Nuclear Information System (INIS)

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

177

Crossing the phantom divide without phantom matter  

OpenAIRE

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

Chimento, Luis P.; Lazkoz, Ruth; Maartens, Roy; Quiros, Israel

2006-01-01

178

Library outreach: addressing Utah's “Digital Divide”  

OpenAIRE

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 Hea...

Mccloskey, Kathleen M.

2000-01-01

179

DIGITAL DIVIDE IN THE EUROPEAN UNION  

OpenAIRE

This paper aims to demonstrate that income, education and infrastructure play a critical role in shaping the divide. The global challenge for the new millennium is to build a society where everyone can access and shareinformation. A fully integrated digital world has become a reality, and all segments of society must embrace it in order to be contributing partners to future success in the EU. As they are fast becoming an essential tool for economic activity, Information and Communication Tech...

Herman, Radu

2009-01-01

180

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

181

Improvement in the voltage grading (axial and radial) of the generator column of a Van de Graaf generator by the use of a resistor chain  

International Nuclear Information System (INIS)

It is well known that the use of a series of resistors, connected between the equipotential rings of a Van de Graaff generator, improves the axial voltage grading of the generator. The work reported in this paper shows how the resistor chain also improves the radial voltage gradient. The electrolytic field mapping technique was adopted in the present work. (Auth.)

182

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

OpenAIRE

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

183

Recumbent folding of divide arches in response to unsteady ice-divide migration  

Science.gov (United States)

Arches in stratigraphic layers directly under a flow divide (Raymond bumps) are predicted by models of steady ice-sheet flow, and have been observed in several ice domes. Here, we model the evolution of these layers when a formerly stationary divide migrates rapidly to a new position, then again becomes stationary, leaving the arched layers in a flank position. As they are then carried downstream with the flow, these abandoned arches can develop into recumbent folds. These folds can occur over a wide range of divide migration speeds. The shearing flow that produces these recumbent folds also distributes the folded layers over a wide distance downstream from the original divide location. If the divide offset is abrupt, 'pre-cores', or material lines comprising core-relative isochrones, can be used to quickly identify portions of an abandoned Raymond bump that would be overturned at any future ice-core site downstream. If, as appears to be the case in Greenland, the divide is never stable long enough to produce a mature arch, folds of this type would not occur. The most likely place to find such folds might be the flank of an ice ridge bounded by unsteady ice streams.

Jacobson, H. Paul; Waddington, Edwin D.

184

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)

185

Substrate temperature and resistivity of Mn and Mn-MgF2 thin film resistors  

International Nuclear Information System (INIS)

Pure Mn and Mn/MgF2 cermet film resistors, 25, 50 and 100nm thick have been prepared at various substrate temperatures 295-455K. The films contained 100 and 39 Vol% Mn. The evaporant mixtures were evaporated from a single boat evaporation source at a pressure of 10-5 torr. The electrical resistivities of the films were measured at the deposition temperatures and found to be between 110 and 1500??-cm. The films were ohmic, they have a negative temperature coefficient of resistance and a low activation energy for conduction (19-82meV). A possible electronic conduction mechanism in the films was suggested to be thermal activated tunnelling. (author)

186

NiCr thin film resistor integration with InP technology  

International Nuclear Information System (INIS)

We present a study of nickel chromium (NiCr) thin film resistors deposited on InP substrate. In contrast to previously published work, the NiCr film resistance changes by a factor of 2.5 after temperature exposure to 250 °C in air. In order to explain this effect, XPS and SIMS tests were performed on NiCr films as-deposited and with temperature treatment. Annealed samples show strong in and out diffusion of Ni and In, respectively. Interfacial reactions were described explaining the severe resistivity decrease. As a solution, a SiN diffusion barrier between NiCr and InP is proposed and applied

187

Time-dependent behaviour of a force-sensitive resistor plantar pressure measurement insole.  

Science.gov (United States)

Thin pressure-measuring insoles have enabled new clinical studies of in-shoe distribution of plantar pressure. One of these new devices, based on force-sensitive resistor (FSR) technology, exhibits time-varying behaviour due to the mechanical properties of the sensor materials. This has been variously attributed to initial bedding in, wear or time-dependency behaviour. Cyclic and sustained loading were used in laboratory conditions to investigate this phenomenon. The results show that the sensitivity of the sensor varies rapidly over the first minute of loading. There is also a slower long-term effect which reduces over time. From this information, procedures for optimal calibration and use are suggested. PMID:8688116

Pitei, D L; Ison, K; Edmonds, M E; Lord, M

1996-01-01

188

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

189

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

190

DIGITAL DIVIDE IN THE EUROPEAN UNION  

Directory of Open Access Journals (Sweden)

Full Text Available This paper aims to demonstrate that income, education and infrastructure play a critical role in shaping the divide. The global challenge for the new millennium is to build a society where everyone can access and shareinformation. A fully integrated digital world has become a reality, and all segments of society must embrace it in order to be contributing partners to future success in the EU. As they are fast becoming an essential tool for economic activity, Information and Communication Technologies (ICT became a vital engine of economic performance. The problem, however, is that in many countries technological diffusion is obstructed by the limited capacity of networks to carry large amounts of knowledge swiftly and the limited access of individuals even to networks in which knowledge products are minimal.

Radu HERMAN

2009-10-01

191

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

192

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)

193

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 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 predictions indicated a much more frequent water release from root

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

1017-10-01

194

Avaliação de modelo de extração da água do solo por sistemas radiculares divididos entre camadas de solo com propriedades hidráulicas distintas Evaluation of a root-soil water extraction model by root systems divided over soil layers with distinct hydraulic properties  

Directory of Open Access Journals (Sweden)

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

Marlon Gomes da Rocha

2010-08-01

195

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

OpenAIRE

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", ...

Dimitrios Zikos; Matteo Roggero

2013-01-01

196

Voltage-Mode All-Pass Filters Using Universal Voltage Conveyor and MOSFET-Based Electronic Resistors  

Directory of Open Access Journals (Sweden)

Full Text Available The paper presents two novel realizations of voltage-mode first-order all-pass filters. Both circuits use single universal voltage conveyor (UVC, single capacitor, and two grounded resistors. Using the two NMOS transistors-based realizations of the electronic resistor with two symmetrical power supplies, presented all-pass filter circuits can be easily made electronically tunable. Proposed filter structures provide both inverting and non-inverting outputs at the same configuration simultaneously and they have high-input and low-output impedances that are desired for easy cascading in voltage-mode operations. The nonidealities of the proposed circuits are also analyzed and compared. The theoretical results of both circuits are verified by SPICE simulations using TSMC 0.35 ?m CMOS process parameters. Based on the evaluation, the behavior of one of the circuits featuring better performance was also experimentally measured using the UVC-N1C 0520 integrated circuit.

N. Herencsar

2011-04-01

197

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

International Nuclear Information System (INIS)

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

198

Three-dimensional random resistor-network model for solid oxide fuel cell composite electrodes  

International Nuclear Information System (INIS)

A three-dimensional reconstruction of solid oxide fuel cell (SOFC) composite electrodes was developed to evaluate the performance and further investigate the effect of microstructure on the performance of SOFC electrodes. Porosity of the electrode is controlled by adding pore former particles (spheres) to the electrode and ignoring them in analysis step. To enhance connectivity between particles and increase the length of triple-phase boundary (TPB), sintering process is mimicked by enlarging particles to certain degree after settling them inside the packing. Geometrical characteristics such as length of TBP and active contact area as well as porosity can easily be calculated using the current model. Electrochemical process is simulated using resistor-network model and complete Butler-Volmer equation is used to deal with charge transfer process on TBP. The model shows that TPBs are not uniformly distributed across the electrode and location of TPBs as well as amount of electrochemical reaction is not uniform. Effects of electrode thickness, particle size ratio, electron and ion conductor conductivities and rate of electrochemical reaction on overall electrochemical performance of electrode are investigated.

199

Low power, lightweight vapor sensing using arrays of conducting polymer composite chemically-sensitive resistors  

Science.gov (United States)

Arrays of broadly responsive vapor detectors can be used to detect, identify, and quantify vapors and vapor mixtures. One implementation of this strategy involves the use of arrays of chemically-sensitive resistors made from conducting polymer composites. Sorption of an analyte into the polymer composite detector leads to swelling of the film material. The swelling is in turn transduced into a change in electrical resistance because the detector films consist of polymers filled with conducting particles such as carbon black. The differential sorption, and thus differential swelling, of an analyte into each polymer composite in the array produces a unique pattern for each different analyte of interest, Pattern recognition algorithms are then used to analyze the multivariate data arising from the responses of such a detector array. Chiral detector films can provide differential detection of the presence of certain chiral organic vapor analytes. Aspects of the spaceflight qualification and deployment of such a detector array, along with its performance for certain analytes of interest in manned life support applications, are reviewed and summarized in this article.

Ryan, M. A.; Lewis, N. S.

2001-01-01

200

Accurate calibration of resistance ratios between 1 M? and 1 G? using series resistors  

International Nuclear Information System (INIS)

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

201

Circular resistor networks for electrical impedance tomography with partial boundary measurements  

International Nuclear Information System (INIS)

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

202

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.

203

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

204

Circuit proposition for copying the value of a resistor into a memristive device supported by HSPICE simulation  

OpenAIRE

Memristor is the fourth fundamental passive circuit element with potential applications in development of analog memories, artificial brains (with the capacity of hardware training) and neuro-science. In most of these applications the memristance of the device should be set to the desired value, which is currently performed by trial and error. The aim of this paper is to propose a circuit for copying the value of the given resistor into a memristive device. HSPICE simulation...

Merrikh-bayat, Farshad; Mirebrahimi, Nafiseh; Bayat, Farhad

2013-01-01

205

The Digital Divide in the Liberal State: a Canadian Perspective  

OpenAIRE

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

Birdsall, William F.

2000-01-01

206

Design of shielded voltage divider for impulse voltage measurement  

International Nuclear Information System (INIS)

The dividers used for the study of the insulation and electric discharge phenomena in high voltage equipments have the problems of the change of response characteristics owing to adjacent bodies and of induced noise. To improve the characteristics, the enclosed type divider shielded with metal has been investigated, and the divider of excellent response has been obtained by adopting the frequency-separating divider system, which is divided into two parts, resistance divider (lower frequency region) and capacitance divider (higher frequency region), for avoiding to degrade the response. Theoretical analysis was carried out in the cases that residual inductance can be neglected or can not be neglected in the small capacitance divider, and that the connecting wires are added. Next, the structure of the divider and the design of the electric field for the divider manufactured on the basis of the theory are described. The response characteristics were measured. The results show that 1 MV impulse voltage can be measured within the response time of 10 ns. Though this divider aims at the impulse voltage, the duration time of which is about that of standard lightning impulse, in view of the heat capacity because of the input resistance of 10.5 k?, it is expected that the divider can be applied to the voltage of longer duration time by increasing the input resistance in future. (Wakatsuki, Y.)

207

Gentilly-2 and Point Lepreau divider plate replacement  

International Nuclear Information System (INIS)

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

208

Water  

Science.gov (United States)

... to drink more water Other drinks How much water do you need? top Water is very important, ... you probably need more water. What about bottled water? top Some people like bottled water for its ...

209

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)

210

Zones of silence: A framework beyond the digital divide  

OpenAIRE

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

211

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

Energy Technology Data Exchange (ETDEWEB)

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

2014-10-21

212

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

International Nuclear Information System (INIS)

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

213

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

International Nuclear Information System (INIS)

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

214

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

215

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

International Nuclear Information System (INIS)

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

216

Water  

Science.gov (United States)

... it tested. You cannot see, taste, or smell lead in drinking water. Therefore, you must ask your water provider whether ... can also reduce or eliminate your exposure to lead in drinking water by consuming only bottled water or water from ...

217

Electrical properties of sputtered Ni-Cr-Al-Cu thin film resistors with Ni and Cr contents  

International Nuclear Information System (INIS)

In this work, we fabricated thin film resistors using three different Ni-Cr-Al-Cu target compositions by using DC/RF magnetron sputter. The electrical properties, such as the sheet resistance and the TCR (temperature coefficient of resistance) of the Ni-Cr-Al-Cu thin films and the effects of annealing in air up to 400 degree C were examined. In general, the TCR was increased as the annealing temperature was increased. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) analysis of a thin film with a composition of 74 : 18 : 4 : 4 wt% (Ni : Cr : Al : Cu) confirmed that the sharp increase in both the sheet resistance and the TCR of the film annealed at 400 degree C in air was due to the formation of the rhombohedral NiO phase in the film. The TCR of Ni-Cr-Al-Cu thin films decreased as the Ni/Cr ratio was decreased at constant Al and Cu. Above 38 wt% of Cr, the TCR became negative. XRD analysis revealed that the decrease in the TCR of Ni-Cr-Al-Cu thin films with decreasing Ni/Cr ratio was due to microcrystalline structures in these thin films. The optimal composition was determined to be 51 : 41 : 4 : 4 wt% (Ni : Cr : Al : Cu) and the TCR of the 'as-deposited' thin films was -27 ppm/ degree C. Through heat treatment, we obtained thin film resistors with low values of the TCR below ±10 ppm/ degree C

218

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

International Nuclear Information System (INIS)

Optically stimulated luminescence (OSL) and thermoluminescence (TL) of ubiquitous materials continue to draw wider attention for individual dosimetry in nuclear and radiation accidents. Use of ubiquitous objects for radiation dosimetry is preferred because the affected persons in such unexpected events are usually not covered by personal dosimetry services and do not carry personal dosimeters. Often accident sites do not have area monitoring system in place. As the main concern of the dosimetry is health effects, a quick distinction of level of exposures of the affected persons for the required medical care becomes important in all accidents involving radiation. Both in large scale nuclear accidents such Fukushima, Chernobyl or Hiroshima and Nagasaki where large population around the accident site get exposed to radiation (evacuation is based on doses) and in smaller but panicky events, such as misuse of radiological exposure device (RED), radiological dispersive device (RDD: 'Dirty Bomb'), improvised nuclear device (IND) and deliberate dispersal of radioactive contaminants, a need for an ubiquitous personal dosimeter is well recognized. As biological dosimetry systems are yet to become viable for measurements of doses with required accuracy and speed, use of physical dosimeters is often explored. Among the various types of physical dosimetry systems, use of TL and OSL by processing common material such as bricks or tiles and measuring the doses cumulated for long permeasuring 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

219

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

220

On locally divided integral domains and CPI-overrings  

OpenAIRE

It is proved that an integral domain R is locally divided if and only if each CPI-extension of ℬ (in the sense of Boisen and Sheldon) is R-flat (equivalently, if and only if each CPI-extension of R is a localization of R). Thus, each CPI-extension of a locally divided domain is also locally divided. Treed domains are characterized by the going-down behavior of their CPI-extensions. A new class of (not necessarily treed) domains, called CPI-closed domains, is introduced. Examples i...

Dobbs, David E.

1981-01-01

221

All About Circuits: Divider Circuits and Kirchhoffâ??s Laws  

Science.gov (United States)

Tony R. Kuphaldt is the creator of All About Circuits, a collection of online textbooks about circuits and electricity. The site is split into volumes, chapters, and topics to make finding and learning about these subjects convenient. Volume 1, Chapter 6: Divider Circuits and Kirchhoffâ??s Laws uses a series of tables and the application of Ohmâ??s law to explain voltage divider circuits and current divider circuits. Kirchhoffâ??s voltage and current laws are successfully demonstrated through a combination of mathematics, drawing, and written explanation. This is a great resource for educators or students.

Kuphaldt, Tony R.

222

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

223

On locally divided integral domains and CPI-overrings  

Directory of Open Access Journals (Sweden)

Full Text Available It is proved that an integral domain R is locally divided if and only if each CPI-extension of ℬ (in the sense of Boisen and Sheldon is R-flat (equivalently, if and only if each CPI-extension of R is a localization of R. Thus, each CPI-extension of a locally divided domain is also locally divided. Treed domains are characterized by the going-down behavior of their CPI-extensions. A new class of (not necessarily treed domains, called CPI-closed domains, is introduced. Examples include locally divided domains, quasilocal domains of Krull dimension 2, and qusilocal domains with the QQR-property. The property of being CPI-closed behaves nicely with respect to the D+M construction, but is not a local property.

David E. Dobbs

1981-03-01

224

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

225

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

226

The Digital Divide: How Wide and How Deep?  

OpenAIRE

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,...

Schloman, Barbara F.

2004-01-01

227

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

OpenAIRE

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

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

2013-01-01

228

Digital divide or digital development?: The Internet in Mexico  

OpenAIRE

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

Curry, James; Kenney, Martin

2006-01-01

229

Digital Divide between Teachers and Students in Urban Bangladesh  

OpenAIRE

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,...

Khalid, Md Saifuddin

2011-01-01

230

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

International Nuclear Information System (INIS)

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

231

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

232

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

233

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.

234

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

Science.gov (United States)

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

Lin, Chun-Hsu; Lee, Ting-Ting

2010-02-01

235

Ouroboros: A Tool for Building Generic, Hybrid, Divide& Conquer Algorithms  

Energy Technology Data Exchange (ETDEWEB)

A hybrid divide and conquer algorithm is one that switches from a divide and conquer to an iterative strategy at a specified problem size. Such algorithms can provide significant performance improvements relative to alternatives that use a single strategy. However, the identification of the optimal problem size at which to switch for a particular algorithm and platform can be challenging. We describe an automated approach to this problem that first conducts experiments to explore the performance space on a particular platform and then uses the resulting performance data to construct an optimal hybrid algorithm on that platform. We implement this technique in a tool, ''Ouroboros'', that automatically constructs a high-performance hybrid algorithm from a set of registered algorithms. We present results obtained with this tool for several classical divide and conquer algorithms, including matrix multiply and sorting, and report speedups of up to six times achieved over non-hybrid algorithms.

Johnson, J R; Foster, I

2003-05-01

236

Constitutional Democracy for Divided Societies: The Indonesian Case  

Directory of Open Access Journals (Sweden)

Full Text Available To build a democracy is to choose a model of democracy. Countries that are building their democracy have often been faced to choose a model of democracy that is suitable to their particular needs. Theoretically and practically, there are some models of democracy. This article discusses the prospect of constitutional democracy for divided societies by putting constitution as a social contract for them. It argues that if a common consensus for a constitution has been reached, then the prospect of a harmonized society can be realized since people have a common platform that binds them legally, politically and socially. By taking Indonesia as a case, it argues that constitutional democracy is relatively able to overcome potential conflict in a divided society. Thus constitutional democracy should be considered as a resolution for divided societies.

Munafrizal Manan

2010-02-01

237

A compact capacitive divider for measuring pulse high voltage  

International Nuclear Information System (INIS)

A compact capacitive divider with response time of 2.8 ns which is used to measure high voltage pulse, is built. It have been applied to measure high voltage pulse and resonant waves of Tesla-transformer-type electron beam accelerator

238

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

Science.gov (United States)

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

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

2012-01-01

239

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

240

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

241

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

Science.gov (United States)

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

Smedley, D A; Rowntree, K M

2012-01-01

242

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

243

Ecuador, the Digital Divide and Small Tourism Enterprises  

Directory of Open Access Journals (Sweden)

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

Stan Karanasios

2014-09-01

244

Integrated power divider/combiner at hybrid orthogonal junctions  

Science.gov (United States)

We propose an integrated power divider/combiner at the interface between silicon nanowire and plasmonic slot waveguide (PSW). The proposed configuration facilitates light access and manipulation in planar nano-plasmonic circuits. The light is incident from a standard silicon nanowire to be accessed by a nano-plasmonic circuit providing subwavelength confinement. The structure overcomes the losses associated with long distance light propagation in nanoplasmonic splitters as coupling and splitting are performed at the same interface with minimal losses. Two PSWs placed orthogonally to the silicon nanowire forming hybrid junctions are exploited for the power dividing/combining functionality. The power splitter has been analyzed using the finite difference time domain (FDTD) numerical method. The ultra-compact proposed device provides wide-band power splitting functionality. A splitting of 34.7%, over most of the wavelength spectrum from 0.8 ?m - 2.5 ?m, is demonstrated.

El Sherif, Mohamed H.; Ahmed, Osman S.; Bakr, Mohamed H.

2014-03-01

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

Preferences for Employment Protection and the Insider-Outsider Divide  

OpenAIRE

Insider-outsider theory suggests that in dual labour markets two groups have opposing preferences regarding protection against dismissals: insiders defend employment protection, because it increases their rents. Outsiders see it as a mobility barrier and demand deregulation. Similar divides are expected for unemployment benefits: as insiders and outsiders have diverging unemployment risks, they should demand different levels of protection. Although these views are influential in the political...

Guillaud, Elvire; Marx, Paul

2013-01-01

247

Job quality in Europe: the North-South divide  

OpenAIRE

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

Cerdeira, Maria Da Conceic?a?o; Kova?cs, Ilona

2008-01-01

248

Crossing of Phantom Divide in $F(R)$ Gravity  

OpenAIRE

An explicit model of $F(R)$ gravity with realizing a crossing of the phantom divide is reconstructed. In particular, it is shown that the Big Rip singularity may appear in the reconstructed model of $F(R)$ gravity. Such a Big Rip singularity could be avoided by adding $R^2$ term or non-singular viable $F(R)$ theory to the model because phantom behavior becomes transient.

Bamba, Kazuharu; Geng, Chao-qiang; Nojiri, Shin Ichi; Odintsov, Sergei D.

2010-01-01

249

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

OpenAIRE

In this paper, we study cyclic stabiliser codes over $\\mathbb{F}_p$ of length dividing $p^t+1$ for some positive integer $t$. We call these $t$-Frobenius codes or just Frobenius codes for short. We give methods to construct them and show that they have efficient decoding algorithms. An important subclass of stabiliser codes are the linear stabiliser codes. For linear Frobenius codes we have stronger results: We completely characterise all linear Frobenius codes. As a consequ...

Dutta, Sagarmoy; Kurur, Piyush P.

2010-01-01

250

Crossing the Phantom Divide Barrier with Scalar Tensor Theories  

OpenAIRE

There is accumulating observational evidence (based on SnIa data) that the dark energy equation of state parameter $w$ may be evolving with time and crossing the phantom divide barrier $w=-1$ at recent times. The confirmation of these indications by future data would indicate that minimally coupled quintessence can not reproduce the observed expansion rate $H(z)$ for any scalar field potential. Here we explicitly demonstrate that scalar tensor theories of gravity (extended q...

Perivolaropoulos, L.

2005-01-01

251

Dividing the Traffic Matrix to Approach Optimal Traffic Engineering  

OpenAIRE

In this paper we propose a new method to approach optimal Traffic Engineering routing. The method consists of dividing the traffic matrix into $N$ sub-matrices, called strata, and route each of these independently. We propose two different implementations of our method in routers. Our method can also be used to compute a very precise approximation of the optimal value of a given objective function for comparison to heuristic Traffic Engineering algorithms. For this application, our algorithm ...

Balon, Simon; Leduc, Guy

2006-01-01

252

Traffic Prediction Based on SVM Training Sample Divided by Time  

OpenAIRE

In recent years, the volume of traffic is rapidly increasing. When vehicles running through the tunnel are more intensive or move slowly, the tunnel environment occurs deteriorated sharply, which affects the normal operation of the vehicle in the tunnel. This paper uses the result of previous mining association rules to select feature items and to establish four training samples divided by time. Then the training samples are utilized to create the SVM classification model. Finally the trained...

Lingli Li; Hongxia Xia; Lin Li; Qingbo Wang

2013-01-01

253

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

254

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

Science.gov (United States)

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

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

2014-04-01

255

Dividing Streamline Formation Channel Confluences by Physical Modeling  

Directory of Open Access Journals (Sweden)

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

Minarni Nur Trilita

2010-02-01

256

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

257

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2014-04-01

258

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

International Nuclear Information System (INIS)

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

259

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

260

Multiple sequence alignment with the Divide-and-Conquer method.  

OpenAIRE

An improved algorithm for the simultaneous alignment of multiple protein and nucleic acid sequences, the Divide-and-Conquer Alignment procedure (DCA), is presented. The basic method described in Tonges,et al. (1996) (Tonges, U., Perrey, S.W., Stoye, J., Dress, A.W.M., 1996. A general method for fast multiple sequence alignment. Gene, 172, GC33-GC41) is generalized to align any number of sequences to work arbitrary (e.g. affine linear) gap penalty functions. Also, the practical efficiency of t...

Stoye, Jens

1998-01-01

261

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

262

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

263

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

Yoh, Tomoaki; Okamura, Ryuji; Nakamura, Yuya; Kobayashi, Atsushi

2014-01-01

264

Divided Saphenectomy for Varicose Vein in Ambulatory Surgery  

OpenAIRE

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 in...

Yoh, Tomoaki; Okamura, Ryuji; Nakamura, Yuya; Kobayashi, Atsushi

2014-01-01

265

CLOBAZAM SINGLE OR DIVIDED DOSE AGAINST DIAZEPAM IN ANXIETY NEUROSIS  

OpenAIRE

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

266

Divide-and-Conquer Learning by Anchoring a Conical Hull  

OpenAIRE

We reduce a broad class of machine learning problems, usually addressed by EM or sampling, to the problem of finding the $k$ extremal rays spanning the conical hull of a data point set. These $k$ "anchors" lead to a global solution and a more interpretable model that can even outperform EM and sampling on generalization error. To find the $k$ anchors, we propose a novel divide-and-conquer learning scheme "DCA" that distributes the problem to $\\mathcal O(k\\log k)$ same-type s...

Zhou, Tianyi; Bilmes, Jeff; Guestrin, Carlos

2014-01-01

267

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2014-04-01

268

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

International Nuclear Information System (INIS)

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

269

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

270

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

271

Efficient Divide-and-Conquer Simulations Of Symmetric FSAs  

CERN Document Server

A finite-state automaton (FSA) is an abstract machine with finite working memory, whose input is a string from a finite alphabet, which reads the input one character at a time, and which has a deterministic transition function. An FSA is symmetric if its output is independent of the order in which the input symbols are read, i.e., if the output is invariant under permutations of the input. We show that, given a symmetric FSA A, there is a deterministic divide-and-conquer process that simulates A whose intermediate results are no larger than the size of A's memory. In comparison, for a general (not necessarily symmetric) FSA, a similar divide-and-conquer implementation has long been known via functional composition but entails an exponential increase in the size of the state space. Our result has applications to parallel processing and to symmetric FSA networks. The first step in the construction is to remove some redundancy in the states of the FSA. The second step is that, assuming the FSA is irredundant, to...

Pritchard, David

2007-01-01

272

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

273

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

274

Universal Service in a Broader Perspective: The European Digital Divide  

Directory of Open Access Journals (Sweden)

Full Text Available Ensuring universal service is a top objective in many countries in order that all the citizens can have access basic communications services. Although the ICT equipment in households and its usage by individuals are essential prerequisites for benefiting from ICTs, the situation in the European Union is far from uniform. This article provides a description of the European information society development scenario using the values reached by the member states in a set of indicators selected for measuring said progress in households. Two tools are used for providing a broader perspective of the digital divide: a composite index and the cluster analysis. Below, a study is provided on what variables are relevant for interpreting the situation that is presented.

Maria Concepcion GARCIA-JIMENEZ

2009-01-01

275

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

276

Operation of a bidirectional voltage-dividing bremsstrahlung diode  

Science.gov (United States)

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.

Harper-Slaboszewicz, V. J.; Lee, J. R.; Hedemann, M. A.; Baldwin, G. T.; Poukey, J. W.; Lorence, L. J., Jr.; Carlson, G. A.; Fowler, W. E.; Faucett, D. L.; Landron, C. O.

1990-04-01

277

Divide and be different: priestly identity in the Persian period  

Scientific Electronic Library Online (English)

Full Text Available SciELO South Africa | Language: English Abstract in english The article focused on the Hebrew root -•” [divide] [bdl] in Priestly and post-Priestly material of the Pentateuch. In Genesis 1 God is the subject of the verb and often enough in the Holiness Code, but in many instances in Leviticus (e.g. 10:10 and 11:47) it is expected of priests to perform the sa [...] me act. It was argued that in this regard priests were to imitate God. The article further argued that these texts helped us to describe Jewish identity in the Persian period as an identity of non-conformity, and they also helped us to describe the priests' own understanding of their role in maintaining this identity.

Esias E., Meyer.

278

Transition state theory in liquids beyond planar dividing surfaces  

International Nuclear Information System (INIS)

The success of transition state theory (TST) in describing the rates of chemical reactions has been less-than-perfect in solution (and sometimes even in the gas phase) because conventional dividing surfaces are only approximately free of recrossings between reactants and products. Recent advances in dynamical systems theory have helped to identify the interconnected manifolds-'superhighways'-leading from reactants to products. The existence of these manifolds has been proven rigorously, and explicit algorithms are available for their calculation. We now show that these extended structures can be used to obtain reaction rates directly in dissipative systems. We also suggest a treatment for the substantially more general case in which the molecular solvent is fully specified by the positions of all its atoms. Specifically, we can construct effective solvent configurations for which the exact TST manifolds can be constructed and used to sample the rates of an open system.

279

Bifurcation in asymmetric plasma divided by a magnetic filter  

Energy Technology Data Exchange (ETDEWEB)

A magnetic filter (MF) reflecting electrons from both sides can separate a low-temperature and low-density subplasma from a high-temperature and high-density main plasma. The one-dimensional numerical simulation by the particle-in-cell code revealed that, depending on the asymmetry, the plasma divided by the MF behaves dynamically or statically [K. Ohi et al., Physics of Plasmas 8, 23 (2001)]. The transition between the two bifurcated states is discontinuous. In the dynamic state, the autonomous potential oscillation in the subplasma is synchronized with the passage of the shock wave structure generated by the modulated ion beam from the main plasma. The stationary phase of the dynamic state appears after the amplitude of the potential oscillation in the subplasma grows exponentially from the thermal noise. In the static state, the system is stable to the growth of the potential oscillation in the subplasma. (author)

Ohi, K.; Naitou, H.; Tauchi, Y.; Fukumasa, O. [Department of Electrical and Electronic Engineering, Yamaguchi Univ., Ube, Yamaguchi (Japan)

2001-05-01

280

Bifurcation in asymmetric plasma divided by a magnetic filter  

International Nuclear Information System (INIS)

A magnetic filter (MF) reflecting electrons from both sides can separate a low-temperature and low-density subplasma from a high-temperature and high-density main plasma. The one-dimensional numerical simulation by the particle-in-cell code revealed that, depending on the asymmetry, the plasma divided by the MF behaves dynamically or statically [K. Ohi et al., Physics of Plasmas 8, 23 (2001)]. The transition between the two bifurcated states is discontinuous. In the dynamic state, the autonomous potential oscillation in the subplasma is synchronized with the passage of the shock wave structure generated by the modulated ion beam from the main plasma. The stationary phase of the dynamic state appears after the amplitude of the potential oscillation in the subplasma grows exponentially from the thermal noise. In the static state, the system is stable to the growth of the potential oscillation in the subplasma. (author)

281

Complex behavior in asymmetric plasma divided by a magnetic filter  

International Nuclear Information System (INIS)

A bifurcation from the static state to the dynamic state in the asymmetric plasma divided by the magnetic filter (MF) is studied by an one-dimensional particles simulation. A low temperature and low density subplasma is in contact with a high temperature and high density main plasma at the MF. In the dynamic state, autonomous oscillation of the electrostatic potential in the subplasma is observed along with the transit of the shock wave structure [K. Ohi, H. Naitou, Y. Tauchi, and O. Fukumasa, Phys. Plasmas 8, 23 (2001)]. By changing the control parameter of B0 very slowly, the existence of the hysteresis in the relation of ??s versus B0 is verified. Here B0 is the strength of the magnetic field at the center of the MF and ??s is twice the amplitude of the self-sustained potential oscillation in the subplasma. (author)

282

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

283

Spike sorting for polytrodes: a divide and conquer approach  

Directory of Open Access Journals (Sweden)

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

Nicholas V. Swindale

2014-02-01

284

Water  

Science.gov (United States)

... just put out with the regular trash are electronics, paints, cleaners, unused medicines, motor oil, and certain ... and leaves. Spills and accidents. Industrial accidents like oil spills can ... (like fruits and vegetables). 6. Of all the earth’s water, how much ...

285

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1997-02-28

286

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

287

Reduced Complexity Divide and Conquer Algorithm for Large Scale TSPs  

Directory of Open Access Journals (Sweden)

Full Text Available The Traveling Salesman Problem (TSP is the problem of finding the shortest path passing through all given cities while only passing by each city once and finishing at the same starting city. This problem has NP-hard complexity making it extremely impractical to get the most optimal path even for problems as small as 20 cities since the number of permutations becomes too high. Many heuristic methods have been devised to reach “good” solutions in reasonable time. In this paper, we present the idea of utilizing a spatial “geographical” Divide and Conquer technique in conjunction with heuristic TSP algorithms specifically the Nearest Neighbor 2-opt algorithm. We have found that the proposed algorithm has lower complexity than algorithms published in the literature. This comes at a lower accuracy expense of around 9%. It is our belief that the presented approach will be welcomed to the community especially for large problems where a reasonable solution could be reached in a fraction of the time.

Hoda A. Darwish

2014-01-01

288

Multidimensional Divide-and-Conquer and Weighted Digital Sums  

CERN Document Server

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

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

2010-01-01

289

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

290

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)

291

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

292

Bridging the transatlantic climate divide. Final project paper. Appendices  

International Nuclear Information System (INIS)

International climate change policy is presently dominated by the different visions of two major blocks, the USA and EU. It is not always realized that a part of these differences is more fundamental than one may expect in view of the historical connections between the populations of the two continents. Socio-cultural aspects like the role of government, the value of individual liberty and the consequences of population density are different in both regions and play an important role in determining what is acceptable policy-wise. Despite the apparent stalemate in formal positions, signs have been detected that indicate that the 'transatlantic divide' on this issue is (slowly) closing. One cause is that bottom-up momentum is building up in the USA, which can eventually push the federal level to initiate a more active policy. Another cause is the finding in the EU that it turns out to be difficult to reach the Kyoto-targets, which results in the development of policy instruments that could be attractive for the USA to endorse or even participate in. Such instruments could have similarities with the Kyoto Protocol. To obtain more insight in the driving forces behind such changes and why they lead to higher or lower acceptability of certain policy instruments, it makes sense to identify attitudinal indicators that signify such changes. By regularly monitoring these attitudinal indicators, e.g., concrete behavior of companies, proportional media attention, formal politicalortional media attention, formal political statements, and relating the value of these indicators to a corresponding set of policy instruments, policy makers at both sides of the Atlantic Ocean have an extra tool at their disposal to frame the issue and identify joint solutions in a way that is acceptable to the other party. This project makes a first attempt to design such a method (dynamic analytic model). It holds promises, and it is recommended to develop this model further in order to support the effectiveness of the climate negotiations

293

National Identity and Xenophobia in an Ethnically Divided Society  

Directory of Open Access Journals (Sweden)

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

Noah Lewin-Epstein

2005-12-01

294

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 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

295

76 FR 55643 - Helena National Forest; Montana; Divide Travel Plan EIS  

Science.gov (United States)

...DEPARTMENT OF AGRICULTURE Forest Service Helena National Forest; Montana; Divide Travel...SUMMARY: The Helena National Forest is preparing an Environmental...ADDRESSES: Send written comments to the Helena National Forest, ATTN: Divide...

2011-09-08

296

Migratory divides and their consequences for dispersal, population size and parasite-host interactions.  

Science.gov (United States)

Populations of migratory birds differ in their direction of migration with neighbouring populations often migrating in divergent directions separated by migratory divides. A total of 26% of 103 passerine bird species in Europe had migratory divides that were located disproportionately often along a longitudinal gradient in Central Europe, consistent with the assumption of a Quaternary glacial origin of such divides in the Iberian and Balkan peninsulas followed by recolonization. Given that studies have shown significant genetic differentiation and reduced gene flow across migratory divides, we hypothesized that an absence of migratory divides would result in elevated rates of gene flow and hence a reduced level of local adaptation. In a comparative study, species with migratory divides had larger population sizes and population densities and longer dispersal distances than species without migratory divides. Species with migratory divides tended to be habitat generalists. Bird species with migratory divides had higher richness of blood parasites and higher growth rates of Staphylococcus on their eggs during the incubation period. There was weaker cell-mediated immunity in adults and stronger cell lysis in species with migratory divides. These findings may suggest that migratory divides constitute barriers to dispersal with consequences for ecology and evolution of distributions, population sizes, habitats and parasite-host interactions. They also suggest that migratory divides may play a role in local adaptation in host-parasite interactions. PMID:21599774

Møller, A P; Garamszegi, L Z; Peralta-Sánchez, J M; Soler, J J

2011-08-01

297

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

298

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 × 10(6)-atom SiC system. As a test of production runs, LDC-DFT-based QMD simulation involving 16?661 atoms is performed on the Blue Gene/Q to study on-demand production of hydrogen gas from water using LiAl alloy particles. As an example of the recombine phase, LDC-DFT electronic structures are used as a basis set to describe global photoexcitation dynamics with nonadiabatic QMD (NAQMD) and kinetic Monte Carlo (KMC) methods. The NAQMD simulations are based on the linear response time-dependent density functional theory to describe electronic excited states and a surface-hopping approach to describe transitions between the excited states. A series of techniques are employed for efficiently calculating the long-range exact exchange correction and excited-state forces. The NAQMD trajectories are analyzed to extract the rates of various excitonic processes, which are then used in KMC simulation to study the dynamics of the global exciton flow network. This has allowed the study of large-scale photoexcitation dynamics in 6400-atom amorphous molecular solid, reaching the experimental time scales. PMID:24832337

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

2014-05-14

299

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

International Nuclear Information System (INIS)

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

300

Experimental study of phase separation in dividing two phase flow  

International Nuclear Information System (INIS)

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

301

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 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.

302

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

303

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)

304

Crossing the Phantom Divide in Extended Dvali-Gabadadze-Porrati Gravity  

OpenAIRE

We propose a phantom crossing Dvali--Gabadadze--Porrati (DGP) model. In our model, the effective equation of state of the DGP gravity crosses the phantom divide line. We demonstrate crossing of the phantom divide does not occur within the framework of the original DGP model or the DGP model developed by Dvali and Turner. By extending their model, we construct a model that realizes crossing of the phantom divide. We find that the smaller the value of the new introduced parame...

Hirano, Koichi; Komiya, Zen

2009-01-01

305

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

OpenAIRE

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

306

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.

307

Computer and Video Games in Family Life: The Digital Divide as a Resource in Intergenerational Interactions  

Science.gov (United States)

In this ethnographic study of family life, intergenerational video and computer game activities were videotaped and analysed. Both children and adults invoked the notion of a digital divide, i.e. a generation gap between those who master and do not master digital technology. It is argued that the digital divide was exploited by the children to…

Aarsand, Pal Andre

2007-01-01

308

The Digital Divide as Cultural Practice: A Cognitive Anthropological Exploration of Japan as an "Information Society"  

Science.gov (United States)

The objective of this dissertation is to explore the socio-cultural contextualization of the digital divide in Japanese society. I undertake this task by developing a theoretical and methodological framework based on the notion of "culture as models," while explicating the cultural dimensions of the digital divide and the dynamics of ICTs,…

Kimura, Tadamasa

2010-01-01

309

Great Divides: The Cultural, Cognitive, and Social Bases of the Global Subordination of Women  

Science.gov (United States)

Categorization based on sex is the most basic social divide. It is the organizational basis of most major institutions, including the division of labor in the home, the workforce, politics, and religion. Globally, women's gendered roles are regarded as subordinate to men's. The gender divide enforces women's roles in reproduction and support…

Epstein, Cynthia Fuchs

2007-01-01

310

Healing the Physical/Spiritual Divide through a Holistic and Hermeneutic Approach to Education  

Science.gov (United States)

In this special edition of the journal, attention is being given to the two dimensions of spirituality and physicality. In this particular paper I argue that there is an unhelpful divide that is often assumed to exist between these two dimensions and that this divide can be transcended or "healed" through a holistic and hermeneutic approach to…

Webster, R. Scott

2013-01-01

311

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

312

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)

313

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.)

314

Measuring Low Concentrations of Liquid Water in Soil  

Science.gov (United States)

An apparatus has been developed for measuring the low concentrations of liquid water and ice in relatively dry soil samples. Designed as a prototype of instruments for measuring the liquidwater and ice contents of Lunar and Martian soils, the apparatus could also be applied similarly to terrestrial desert soils and sands. The apparatus is a special-purpose impedance spectrometer: Its design is based on the fact that the electrical behavior of a typical soil sample is well approximated by a network of resistors and capacitors in which resistances decrease and capacitances increase (and, hence, the magnitude of impedance decreases) with increasing water content.

Buehler, Martin

2009-01-01

315

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.

316

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

317

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

Directory of Open Access Journals (Sweden)

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

Surya Singh

2015-03-01

318

Development of a one-chip quantized Hall resistance voltage divider  

Science.gov (United States)

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

Domae, Atsushi; Oe, Takehiko; Matsuhiro, Kenjiro; Kiryu, Syogo; Kaneko, Nobu-hisa

2012-12-01

319

Millimeter-wave Si/SiGe HBT frequency divider using dynamic and static division stages  

OpenAIRE

In this paper, the authors present a fully integrated frequency divider with a divide ratio of 32, using a 0.8 um Si/SiGe HBT technology. The divider operates at least up to 40 GHz and shows outstanding performance such as broad frequency of operation, compact die area (1130 x 460 um2), reasonable power consumption (150 mA at 5 V supply voltage or 110 mA at 4 V with slightly degraded performance) and excellent sensitivity. The integrated circuit combines the advantages of the dynamic topol...

Chartier, Se?bastien; So?nmez, Ertugrul; Dederer, Jochen; Schleicher, Bernd; Schumacher, Hermann

2008-01-01

320

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.)

321

Defining and dividing the greater Caribbean: insights from the biogeography of shorefishes.  

Science.gov (United States)

The Greater Caribbean biogeographic region is the high-diversity heart of the Tropical West Atlantic, one of four global centers of tropical marine biodiversity. The traditional view of the Greater Caribbean is that it is limited to the Caribbean, West Indies, southwest Gulf of Mexico and tip of Florida, and that, due to its faunal homogeneity, lacks major provincial subdivisions. In this scenario the northern 2/3 of the Gulf of Mexico and southeastern USA represent a separate temperate, "Carolinian" biogeographic region. We completed a comprehensive re-assessment of the biogeography of the Greater Caribbean by comparing the distributions of 1,559 shorefish species within 45 sections of shelf waters of the Greater Caribbean and adjacent areas. This analysis shows that that the Greater Caribbean occupies a much larger area than usually thought, extending south to at least Guyana, and north to encompass the entire Carolinian area. Rather than being homogenous, the Greater Caribbean is divided into three major provinces, each with a distinctive, primarily tropical fauna: (1) a central, tropical province comprising the West Indies, Bermuda and Central America; (2) a southern, upwelling-affected province spanning the entire continental shelf of northern South America; and (iii) a northern, subtropical province that includes all of the Gulf of Mexico, Florida and southeastern USA. This three-province pattern holds for both reef- and soft bottom fishes, indicating a general response by demersal fishes to major variation in provincial shelf environments. Such environmental differences include latitudinal variation in sea temperature, availability of major habitats (coral reefs, soft bottom shorelines, and mangroves), and nutrient additions from upwelling areas and large rivers. The three-province arrangement of the Greater Caribbean broadly resembles and has a similar environmental basis to the provincial arrangement of its sister biogeographic region, the Tropical Eastern Pacific. PMID:25054225

Robertson, D Ross; Cramer, Katie L

2014-01-01

322

75 FR 54085 - Divide Ranger District, Rio Grande National Forest; Colorado; Big Moose Vegetation Management...  

Science.gov (United States)

...DEPARTMENT OF AGRICULTURE Forest Service Divide Ranger District, Rio Grande National Forest; Colorado; Big Moose Vegetation Management Project AGENCY: Forest Service, Rio Grande National Forest, USDA. ACTION: Corrected Notice of Intent to...

2010-09-03

323

DCA: an efficient implementation of the divide-and-conquer approach to simultaneous multiple sequence alignment  

OpenAIRE

MOTIVATION: DCA is a new computer program for multiple sequence alignment which utilizes a 'divide-and-conquer' type of heuristic approach. AVAILABILITY: The algorithm is freely available from http://bibiserv.TechFak.Uni-Bielefeld.DE/dca/.

Stoye, Jens; Moulton, Vincent; Dress, Andreas

1997-01-01

324

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)

325

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

326

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

OpenAIRE

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,...

Schloman, B.

2004-01-01

327

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

OpenAIRE

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

Curry, James; Kenney, Martin

2007-01-01

328

Integrative tracking methods elucidate the evolutionary dynamics of a migratory divide  

OpenAIRE

Migratory divides, the boundary between adjacent bird populations that migrate in different directions, are of considerable interest to evolutionary biologists because of their alleged role in speciation of migratory birds. However, the small size of many passerines has traditionally limited the tools available to track populations and as a result, restricted our ability to study how reproductive isolation might occur across a divide. Here, we integrate multiple approaches by using genetic, g...

Alvarado, Allison H.; Fuller, Trevon L.; Smith, Thomas B.

2014-01-01

329

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.

330

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

CERN Document Server

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

López Peláez, Antonio

2013-01-01

331

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

OpenAIRE

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

Gurstein, Michael

2007-01-01

332

Exploring the Future of the Digital Divide through Ethnographic Futures Research  

OpenAIRE

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

333

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)

334

Marketing mix of chosen Slovak mineral water  

OpenAIRE

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

335

A high-frequency divider in 0.18 µm SiGe BiCMOS technology  

Science.gov (United States)

High speed frequency dividers are critical parts of frequency synthesisers in wireless systems. These dividers allow the output frequency from a voltage controlled oscillator to be compared with a much lower external reference frequency that is commonly used in these synthesisers. Common trade-offs in high frequency dividers are speed of division, power consumption, real estate area, and output signal dynamic range. In this paper we demonstrate the design of a high frequency, low power divider in 0.18 µm SiGe BiCMOS technology. Three dividers are presented, which are a regenerative divider, a master-slave divider, and a combination of regenerative and master-slave dividers to perform a divide-by-8 chain. The dividers are used as part of a 60 GHz frequency synthesizer. The simulation results are in agreement with measured performance of the regenerative divider. At 48 GHz the divider consumes 18 mW from a 1.8 V supply voltage. The master-slave divider operates up to 36 GHz from a very low supply voltage, 1.8 V. The divide-by-8 operates successfully from 40 GHz to 50 GHz.

Kamal, Noorfazila; Zhu, Yingbo; Hall, Leonard T.; Al-Sarawi, Said F.; Burnet, Craig; Holland, Ian; Khan, Adnan; Pollok, Andre; Poyner, Justin; Boers, Micheal; Howarth, James A.; Lauterbach, Adam; Harrison, Jeffrey; Rathmell, James; Batty, Michael; Parker, Anthony; Davis, Linda M.; Cowley, William G.; Weste, Neil H. E.; Abbott, Derek

2007-01-01

336

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

337

Water watch  

International Nuclear Information System (INIS)

This issue of open-quotes Water Watchclose quotes focuses on summer streamflow. In addition, a summary of streamflow, soil moisture, and water supply conditions through the end of May is presented. In addition, short-term streamflow forecasts are given. Forecasts are based on the National Weather Service US Climate Analysis Center's 90-day outlook. Temperature and precipitation probability estimates given in the outlook are based primarily on the average of monthly forecasts since 1974 and seasonal forecasts since 1959 at 100 US weather reporting stations. Regional analyses are based on reports and data provided by the National Weather Service Office of Hydrology and River Forecast Centers, the US Department of Agriculture, the Bureau of Reclamation, the Soil Conservation Service, the California Department of Water Resources, and the US Geological Survey. For purposes of reporting, the US is divided into six regions. The data presented can be used to observe how weather conditions affect hydro generation in April

338

Unique dynamic behaviors of ice divides: Siple Dome and the rheological properties of ice  

Science.gov (United States)

The constitutive relationship between applied stress and deformation rate of ice controls the dynamic behavior of the divide regions of ice sheets. I use finite-element modelling to explore three aspects of flow near a divide: (1) the increased relative activity of linear creep mechanisms at low stress, (2) the impact of sliding on stratigraphy, and (3) the role of crystal fabric in deformation. Raymond (1983) showed that a special flow pattern emerges near an ice divide when ice is modelled using Glen's flow law. I show that the dominance of linear creep mechanisms at low stress tends to decrease the prominence of the special divide flow pattern. No Raymond bump forms in the isochrones, and younger ice appears deeper in the ice column, when compared to a more conventional Glen divide. When nonlinear rheological properties are coupled with a strongly anisotropic fabric, the special divide flow pattern is enhanced. Crystal fabric has little effect when the linear term dominates deformation rate. Finally, my model results show that basal sliding tends to redistribute the longitudinal stresses within the ice such that the special divide flow pattern is suppressed. I use these results and available data to study Siple Dome, West Antarctica. The divide region of Siple Dome is presently in steady state, it has thinned at most 40 meters in the last 2000 years, and has been an elevated dome-like feature for much of Holocene. This contrasts with other sites around the Ross Sea Embayment with show modern thinning. Using unique measurements of vertical strain throughout the depth of Siple Dome together with a finite-element flow model, I assess the relative importance of the linear term in the flow law compared to the effect crystal fabric. The linear term does contribute to flow at Siple Dome; the crossover stress is k = 0.22 bar. The band of strong crystal fabric around 750 m depth modifies the divide flow pattern, and, on the flanks, shear strain is concentrated within this layer, rather than in the deeper basal ice, creating a false-bed effect.

Pettit, Erin C.

339

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, David

2010-01-01

340

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

Science.gov (United States)

Using functional magnetic resonance imaging (fMRI), we measured brain activity of human participants while they performed a sentence congruence judgment task in either the visual or auditory modality separately, or in both modalities simultaneously. Significant performance decrements were observed when attention was divided between the two modalities compared with when one modality was selectively attended. Compared with selective attention (i.e., single tasking), divided attention (i.e., dual-tasking) did not recruit additional cortical regions, but resulted in increased activity in medial and lateral frontal regions which were also activated by the component tasks when performed separately. Areas involved in semantic language processing were revealed predominantly in the left lateral prefrontal cortex by contrasting incongruent with congruent sentences. These areas also showed significant activity increases during divided attention in relation to selective attention. In the sensory cortices, no crossmodal inhibition was observed during divided attention when compared with selective attention to one modality. Our results suggest that the observed performance decrements during dual-tasking are due to interference of the two tasks because they utilize the same part of the cortex. Moreover, semantic dual-tasking did not appear to recruit additional brain areas in comparison with single tasking, and no crossmodal inhibition was observed during intermodal divided attention. PMID:25745395

Moisala, Mona; Salmela, Viljami; Salo, Emma; Carlson, Synnöve; Vuontela, Virve; Salonen, Oili; Alho, Kimmo

2015-01-01

341

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

342

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

Directory of Open Access Journals (Sweden)

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

Cristina Richichi

2013-07-01

343

Versatile element for free-space dividing and redirecting neutral-atom clouds  

International Nuclear Information System (INIS)

We introduce a tunnel lock that can be exploited to divide, delay, and alter the direction of traveling clouds of cold atoms. This versatile free-space element is implemented by crossing two atom tunnels formed by low-intensity, blue-detuned dark-hollow (Bessel mode) laser beams. We show that clouds of cold Rb atoms initially moving within one tunnel can be transferred to the other without heating by gating the intensities of the two tunnels--a tunnel lock--with an efficiency limited by the overlap volume. The element also can be used to divide a single cloud into smaller clouds, each having a distinct momentum

344

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

345

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

OpenAIRE

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

Livingstone, Sonia; Helsper, Ellen

2007-01-01

346

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)

347

Optimal choice of dividing surface for the computation of quantum reaction rates  

CERN Document Server

We consider the calculation of quantum mechanical rate constants for chemical reactions via algorithms that utilize short time values of the symmetrized flux-flux correlation function. We argue that the dividing surface that makes optimal use of the short time quantum information is the surface that minimizes the value at the origin of the symmetrized flux-flux correlation function. We also demonstrate that, in the classical limit, this quantum variational criterion produces the same dividing surface as Wigner's variational principle. Finally, we argue that the quantum variational criterion behaves in a nearly optimal fashion with respect to the minimization of the extent of re-crossing flux.

Predescu, C; Predescu, Cristian; Miller, William H.

2004-01-01

348

The Racial Divide in Support for the Death Penalty: Does White Racism Matter?  

Science.gov (United States)

Using data from the 2000 National Election Study, this research investigates the sources of the racial divide in support for capital punishment with a specific focus on white racism. After delineating a measure of white racism, we explore whether it can account for why a majority of African Americans oppose the death penalty while most whites…

Unnever, James D.; Cullen, Francis T.

2007-01-01

349

Bridging the Divide with a Question and a Kaleidoscope: Designing an Enquiry in a Challenging Setting  

Science.gov (United States)

The Association for Historical Dialogue and Research (AHDR) is a Cyprus-based organization that works to foster dialogue among history teachers and other educators across the divide in Cyprus. In one of their UN-funded projects, AHDR members worked with UK colleagues to shape a lesson sequence and resources on the Ottoman period in Cyprus. Here…

Counsell, Christine; Foster, Rachel; Georgiou, Maria; Mavrada, Maria; Onurkan, Meltem; Partridge, Mary; Samani, Hasan

2012-01-01

350

The Divide and Conquer Exercise: Finding the Essence of Difficult Readings  

Science.gov (United States)

Objective: In this exercise, students collectively summarize a long and perhaps difficult reading into a shorter, more condensed version of itself; in the process, students experience the virtues of teamwork (the divide and conquer approach), gain valuable reading and note-taking skills, and collectively distill the essence of a reading in class.…

Peterson, Valerie V.

2006-01-01

351

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

352

An improved fully integrated, high-speed, dual-modulus divider  

Science.gov (United States)

A fully integrated 2n/2n+1 dual-modulus divider in GHz frequency range is presented. The improved structure can make all separated logic gates embed into correlative D flip—flops completely. In this way, the complex logic functions can be performed with a minimum number of devices and with maximum speed, so that lower power consumption and faster speed are obtained. In addition, the low-voltage bandgap reference needed by the frequency divider is specifically designed to provide a 1.0 V output. According to the design demand, the circuit is fabricated in 0.18 ?m standard CMOS process, and the measured results show that its operating frequency range is 1.1–2.5 GHz. The dual-modulus divider dissipates 1.1 mA from a 1.8 V power supply. The temperature coefficient of the reference voltage circuit is 8.3 ppm/°C when the temperature varies from ?40 to +125 °C. By comparison, the dual-modulus divide designed in this paper can possess better performance and flexibility.

Zheng, Sun; Yong, Xu; Guangyan, Ma; Hui, Shi; Fei, Zhao; Ying, Lin

2014-11-01

353

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

OpenAIRE

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

354

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

OpenAIRE

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

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

2012-01-01

355

Divided Loyalists or Conditional Cooperators? Creating Consensus about Cooperation in Multiple Simultaneous Social Dilemmas  

OpenAIRE

The current social dilemma literature lacks theoretical consensus regarding how individuals behave when facing multiple simultaneous social dilemmas. The divided-loyalty hypothesis, from organizational theory, predicts that cooperation will decline as individuals experience multiple social dilemmas with different compared to the same group members. The conditional-cooperation hypothesis, from behavioral economics, predicts that cooperation will increase as individuals experience multiple soci...

Mccarter, Matthew; Samek, Anya; Sheremeta, Roman

2014-01-01

356

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2008-09-18

357

The Indonesian Digital Library Network Is Born To Struggle with the Digital Divide.  

Science.gov (United States)

Describes the Indonesian Digital Library Network that is designed to develop Indonesia as a knowledge-based society. Highlights include the digital divide; problems in a developing country, including Internet accessibility, bandwidth capacity, and network delays; gathering information about national assets; information infrastructure; data…

Fahmi, Ismail

2002-01-01

358

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.

359

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

360

Comments on John Willinsky's Learning to Divide the World: Education at Empire's End  

Science.gov (United States)

John Willinsky's view that imperialism and its legacy remain the driving force that divides the world into "superior" and "inferior" cultures fails to take into account other forces that also encourage peoples of different cultures to emphasize the differences between themselves. He is correct in noting that imperialism led to much injustice and…

Wang, Tsung Juang

2006-01-01

361

A Nonstationary Halley’s Iteration Method by Using Divided Differences Formula  

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents a new nonstationary iterative method for solving non linear algebraic equations that does not require the use of any derivative. The study uses only the Newton’s divided differences of first and second orders instead of the derivatives of (1.

Nasr Al Din Ide

2012-02-01

362

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

363

Mapping the Digital Divide in Britain: Implications for Learning and Education  

Science.gov (United States)

The internet presents many potential opportunities for people to learn for both formal and informal purposes. However, not everyone is able to make the most of the internet for learning. This paper utilises quantitative nationally representative survey data of internet use in Britain in order to explore the digital divide in relation to learning…

Eynon, Rebecca

2009-01-01

364

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

365

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

366

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 irescine 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

367

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.

368

Toxicological aspects of water  

International Nuclear Information System (INIS)

Different toxicological aspects of water have been studied, remarking the activity of various chemical substances in the organism. These substances are divided in: trace metals (Sb, As, Cd, Zn, Cu, Cr, Fe, Mn, Hg, Ni, Pb, Se), other contaminants (CN-, polycyclic aromatic hydrocarbons, phenols, pesticides, detergents) and radioactivity. Finally, some considerations on this subject are made

369

The USGS Water Science School  

Science.gov (United States)

Chock full of information about water, the US Geological Survey's (USGS) Water Science for Schools is an enjoyable site for educators and students alike. From Water Basics to Special Topics, this easily navigable site teaches students about the importance of water in their everyday lives. Visitors confused about terminology can refer to the glossary, a tool that defines terms used within the site and in the water field in general. An activity center allows educators and students to apply their newly-gained knowledge. The picture gallery, which is divided into four categories for easy browsing, shows water in action as well as human and animal interactions with water.

370

The quantum divide why Schrödinger's cat is either dead or alive  

CERN Document Server

Using a selection of key experiments performed over the past 30 years or so, we present a discussion of the strikingly counter-intuitive phenomena of the quantum world that defy explanation in terms of everyday "common sense" reasoning, and we provide the corresponding quantum mechanical explanations with a very elementary use of associated formalism. Most, but certainly not all, of the experiments we describe are optical experiments involving a very small number of photons (particles of light). We begin with experiments on the wave-particle duality of electrons, proceed to experiments on the particle nature of light and single photon interference, delayed choice experiments and interaction-free detection, then go on to experiments involving the interference of two photons, quantum entanglement and Bell's Theorem, quantum teleportation, large-scale quantum effects and the divide between the classical and quantum worlds, addressing the question as to whether or not there is such a divide.

Gerry, Christopher C

2013-01-01

371

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

Directory of Open Access Journals (Sweden)

Full Text Available This paper examines the political implications of dividing the commons through the case study of private fishing lots in the Tonle Sap Great Lake of Cambodia. The de facto private property in Tonle Sap lasted for over 100 years until the government abolished the system completely in March 2012. Unlike conventional studies of the commons which assume away the question of divisibility as too costly to be realistic, we argue that divided management occurs even when the cost is very high. This “cost” is not merely economic, but also political. Our case study illustrates how this political cost is channeled through a network of influential people to maintain the resource system and how a private property on the commons can be demolished, also for political reasons.

Thol Dina

2015-03-01

372

Divide sampling-based hybrid temporal-spatial prediction coding for H.264/AVC  

Science.gov (United States)

A divide sampling-based hybrid temporal-spatial prediction coding algorithm is designed to further improve the coding performance of the conventional H.264/AVC coding. In the proposed algorithm, a frame is first divided into four equal-sized subframes, and the first subframe is coded using the rate distortion optimization model with inter- or intraprediction adaptively. Then, the optimal prediction method of the macroblock in other subframes is selected flexibly and reasonably from intraprediction, the fast interprediction, and the spatial interpolation prediction. The simulation results show that compared with the conventional H.264/AVC coding, the average bit rate is reduced by 6.15% under the same peak signal-to-noise ratio (PSNR), the average PSNR is increased by 0.22 dB under the same bit rate, and the average coding time is saved by 12.40% in the proposed algorithm.

Li, Hongwei; Song, Rui; Wu, Chengke; Zhang, Jie

2011-11-01

373

ESTADO DEL ARTE EN LAS IMPLEMENTACIONES PARALELAS DE DIVIDE Y VENCERÁS  

Directory of Open Access Journals (Sweden)

Full Text Available

Divide y Vencerás, es una técnica de diseño de algoritmos ampliamente utilizada en la solución de problemas. Su implementación en paralelo resulta natural. En este trabajo se realiza una revisión bibliográfica acerca del desarrolo de algoritmos paralelos con este paradigma. En ambientes paralelos heterogéneos se mejoran las prestaciones, si en el diseño de algoritmos se tienen en cuenta las características de los procesadores utilizados y de las comunicaciones entre elos. Los trabajos analizados desarrolan implementaciones paralelas de algoritmos basados en "Divide y Vencerás" solamente en sistemas homogéneos. Resulta imprescindible el estudio y desarrollo de este paradigma en ambientes heterogéneos.

Ernesto Carbonell Rigores

2006-04-01

374

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

Science.gov (United States)

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

Che, Jian; Tian, Wei-zhu

2005-04-01

375

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

376

Water Foundations Teachers Guide. The Science of Florida's Water Resources: Lesson Plans for Teachers and Students.  

Science.gov (United States)

This document features lesson plans for teachers and students on Florida's water resources. The guide is divided into four grade levels: K-2, 3-5, 6-8, and 9-12. Each grade level includes objectives, guides, and five lesson plans. K-2 lesson plans include: (1) "We Are Water"; (2) "Why Water is Extra Special"; (3) "Water's Changing Shapes"; (4)…

2001

377

Minimum Requirements for Efficient Transduction of Dividing and Nondividing Cells by Feline Immunodeficiency Virus Vectors  

OpenAIRE

The development of gene delivery vectors based on feline immunodeficiency virus (FIV) is an attractive alternative to vectors based on primate sources for the delivery of genes into humans. To investigate the requirements for efficient transduction of dividing and nondividing cells by vector particles based on FIV, a series of packaging and vector constructs was generated for which viral gene expression was minimized and from which unnecessary cis-acting sequences were deleted. Pseudotyped ve...

Johnston, Julie C.; Gasmi, Mehdi; Lim, Leland E.; Elder, John H.; Yee, Jiing-kuan; Jolly, Douglas J.; Campbell, Kevin P.; Davidson, Beverly L.; Sauter, Sybille L.

1999-01-01

378

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

OpenAIRE

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 f...

Rapatzikou, Tatiani G.

2012-01-01

379

Digital Divides and the 'First Mile': Framing First Nations Broadband Development in Canada  

OpenAIRE

Across Canada, rural and remote First Nations face a significant 'digital divide'. As self-determining autonomous nations in Canada, these communities are building broadband systems to deliver public services to their members and residents. To address this challenge, First Nations are working towards a variety of innovative, locally driven broadband development initiatives. This paper contributes a theoretical discussion that frames our understanding of these initiatives by drawing on the par...

Rob McMahon; Donnell, Susan O.; Richard Smith; Brian Walmark; Brian Beaton; Jason Simmonds

2011-01-01

380

Pharmacokinetics of carboplatin at a dose of 750 mg m-2 divided over three consecutive days.  

OpenAIRE

Pharmacokinetics of the cisplatin analogue carboplatin were studied in patients with disseminated ovarian and testicular cancer. Carboplatin 750 mg m-2 divided over three consecutive days was given as part of an ablative combination regimen followed by autologous bone marrow transplantation. Platinum (Pt) in plasma, plasma ultrafiltrate and urine was determined up to 96 h after the last drug dose by atomic absorption spectrometry. Carboplatin was measured by high performance liquid chromatogr...

Mulder, P. O.; Vries, E. G.; Uges, D. R.; Scaf, A. H.; Sleijfer, D. T.; Mulder, N. H.

1990-01-01

381

An improved capacitive divider probe for plasma potential measurements in the Phaedrus tokamak  

International Nuclear Information System (INIS)

High bandwidth capacitive probes are useful tools for potentials measurements in the tokamak scrape off layer. An improved capacitive divider probe design with very high frequency bandwidth is shown. The gain of this system is between 0 and -8 dB for frequencies from 0.1 Hz to more than 100 MHz, with the -3 dB point at approximately 40 MHz. The probe structure, circuits, performance, and experimental results from the Phaedrus-T tokamak are given

382

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

OpenAIRE

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 reconciliation, which could be described by four major indicators: recruiting policy, civil-military mutual support movement, the private sector’s engagement in military procurement and private employers’ participation i...

Yongchang Wang

2009-01-01

383

Divided Attention Improves Delayed, but Not Immediate Retrieval of a Consolidated Memory  

OpenAIRE

A well-documented dissociation between memory encoding and retrieval concerns the role of attention in the two processes. The typical finding is that divided attention (DA) during encoding impairs future memory, but retrieval is relatively robust to attentional manipulations. However, memory research in the past 20 years had demonstrated that retrieval is a memory-changing process, in which the strength and availability of information are modified by various characteristics of the retrieval p...

Kessler, Yoav; Vandermorris, Susan; Gopie, Nigel; Daros, Alexander; Winocur, Gordon; Moscovitch, Morris

2014-01-01

384

Genetic modification of dividing cells using episomally maintained S/MAR DNA vectors  

OpenAIRE

The development of episomally maintained DNA vectors to genetically modify dividing cells efficiently and stably, without the risk of integration-mediated genotoxicity, should prove to be a valuable tool in genetic research. In this study, we demonstrate the utility of Scaffold/Matrix Attachment Region (S/MAR) DNA vectors to model the restoration of a functional wild-type copy of the gene folliculin (FLCN) implicated in the renal cancer Birt-Hogg-Dubé (BHD). Inactivation of FLCN has been sho...

Wong, Suet-ping; Harbottle, Richard Paul

2013-01-01

385

Asteroid Lightcurve Analysis at CS3-Palmer Divide Station: 2014 October-December  

Science.gov (United States)

Lightcurves for 18 main-belt asteroids were obtained at the Center for Solar System Studies-Palmer Divide Station (CS3-PDS) from 2014 October through December. All but one of the asteroids were a member of the Hungaria orbital group or collisional family, observed as follow-up to previous apparitions to check for undiscovered satellites, to improve previous binary discovery parameters, or to obtain data for spin axis and shape modeling.

Warner, Brian D.

2015-04-01

386

Bridging the Divide: Tensions Between the Biophysical and Social Sciences in An Interdisciplinary Sustainability Science Project  

OpenAIRE

Interdisciplinary research has gained tremendous popularity in higher education over the past several decades and funding for such efforts through federal agencies has underscored its relevance. In sustainability science, in particular, interdisciplinarity is seen as integral to the research endeavor. However, a paucity of empirical evidence exists regarding the process of interdisciplinary endeavors, particularly those that cross the social-biophysical science divide. The current study incor...

Gardner, Susan K.

2014-01-01

387

Background of the Analysis of a Fully-Scalable Digital Fractional Clock Divider  

OpenAIRE

It was previously shown that the BRESENHAM algorithm is well-suited for digital fractional clock generation. Specifically, it proved to be the optimal approximation of a desired clock in terms of the switching edges provided by an available reference clock. Moreover, some synthesis results for hardwired dividers on Altera FPGAs showed that this technique for clock division achieves a high performance often at or close to the maximum frequency supported by the devices for moderate bit widths o...

Preußer, Thomas B.

2012-01-01

388

Application of the hybrid multiobjective optimization methods on the capacitive voltage divider  

OpenAIRE

This paper presents application of multiobjective optimization methods on a capacitive divider finite element model. Modeling is based on the differential evolution algorithm (DE), including the concept of the Pareto nondominance. Through calculations, this concept allows differential evolution algorithm variation in order to achieve uniformly distributed results on the Pareto front, including the lowest population size as possible. Selection step, as a part of the differential evolution meth...

Kitak, Peter; Tic?ar, Igor; Pihler, Joz?e; Glotic?, Adnan; Popovic?, Jelena; Biro?, Oszkar; Preis, Kurt

2012-01-01

389

Book review: Divided nations: why global governance is failing and what we can do about it  

OpenAIRE

"Divided Nations: Why Global Governance is Failing and What We Can Do About It." Ian Goldin. Oxford University Press. March 2013. --- Humanity today faces a number of international challenges which spill over national boundaries: climate change, finance, pandemics, cyber security, and migration. It is becoming increasingly apparent that bodies created to assist in global governance – those such as the UN, the IMF, and the World Bank – are inadequate for the task of managing such risk i...

Hearson, Martin

2013-01-01

390

Maintenance of sealing surfaces of the main dividing plane of reactor  

International Nuclear Information System (INIS)

Pressure components of the primary and the secondary circuit of nuclear power plant are exposed to high super-load, straining and degradation influences, for e.g. fatigue, irradiation embrittlement of pressure vessel of the reactor, ageing and likewise. In this paper maintenance of sealing surfaces of the main dividing plane of reactor of the V-1 NPP in Jaslovske Bohunice is described. (author)

391

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

OpenAIRE

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

Ojo, Bamidele A.

2009-01-01

392

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

OpenAIRE

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...

Rachid Belhaj; Mohamed Tkiouat

2013-01-01

393

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

OpenAIRE

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 o...

Babeesh Kumar; Sushila Vikas Maheshkar; Ankur Singh Bist

2014-01-01

394

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

Directory of Open Access Journals (Sweden)

Full Text Available 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.

Mahmoud Z. Iskandarani

2008-01-01

395

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

OpenAIRE

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

396

OMCVD on Fluidized Divided Substrates : a Potential Method for the Preparation of Catalysts  

OpenAIRE

The OMCVD method has been used to deposit highly pure metal particles on porous divided substrates in order to prepare metal supported catalysts. A fluidized bed reactor has been especially designed and the requirements of CVD and fluidization have been taken into account to select convenient experimental conditions. Three organometallic compounds of rhodium have been selected and their thermal decomposition under He and He/H2 mixtures studied by infrared spectroscopy and on-line mass spectro...

Feurer, R.; Reynes, A.; Serp, P.; Kalck, P.; Morancho, R.

1995-01-01

397

The thermal vacuum process features of continuous production of finely-divided materials  

Directory of Open Access Journals (Sweden)

Full Text Available The scientific and technical development of energy-efficient techniques of drying and pulverizing of dispersed materials is conducted. Drying duration and pulverizing is measured in seconds due to the maximum evaporation surface, rapid heating of the dried material, reducing the environment pressure. It is shown a diagram of thermal vacuum unit construction, allowing accelerate the drying process of dispersed materials and simultaneously obtain a finely-divided powder.

????? ?????????? ?????

2014-12-01

398

Divide & Concur and Difference-Map BP Decoders for LDPC Codes  

OpenAIRE

The "Divide and Concur'' (DC) algorithm, recently introduced by Gravel and Elser, can be considered a competitor to the belief propagation (BP) algorithm, in that both algorithms can be applied to a wide variety of constraint satisfaction, optimization, and probabilistic inference problems. We show that DC can be interpreted as a message-passing algorithm on a constraint graph, which helps make the comparison with BP more clear. The "difference-map'' dynamics of the DC algor...

Yedidia, Jonathan S.; Wang, Yige; Draper, Stark C.

2010-01-01

399

A Countryside Perspective of Queer : - queering the city/countryside divide  

OpenAIRE

This thesis contributes with a countryside perspective to queer research by highlighting the countryside as a context where queer lives are lived. In the thesis I problematize the city/countryside divide with a view of the concept of queer as dependent on space and time.  The empirical materials are generated through a workshop on queerness, gathering people living within a countryside context; the materials consist of a discussion and written responses to questions on queerness and the city...

Gagnesjo?, Sara

2014-01-01

400

Mobile Phones Bridging the Digital Divide for Teens in the US?  

OpenAIRE

In 2009, just 27% of American teens with mobile phones reported using their devices to access the internet. However, teens from lower income families and minority teens were significantly more likely to use their phones to go online. Together, these surprising trends suggest a potential narrowing of the digital divide, offering internet access to those without other means of going online. This is an important move, as, in today’s society, internet access is central to active citizenship in ...

Katie Brown; Campbell, Scott W.; Rich Ling

2011-01-01

401

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

402

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

Science.gov (United States)

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

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

2013-01-01

403

Mild traumatic brain injury and its sequelae: characterisation of divided attention deficits.  

Science.gov (United States)

Deficits in divided attention occur after a mild traumatic brain injury (MTBI) but many extant tasks lack sensitivity for detecting subtle cognitive difficulties. We use the Test d'Attention Partagee Informatise (TAPI), a novel dual-task paradigm, to investigate the impact of MTBI on the ability to divide attention between two stimuli sources. Individuals with MTBI (n=37) were evaluated within the first week following head trauma and at three months post-injury. A healthy control (HC) group (n=79) was also assessed. The primary outcome was reaction time and there were three different conditions that included visual target detection and auditory digit span tasks. Analyses utilised repeated measures ANOVA and ANCOVA models that adjusted for relevant variables including post-concussive and affective symptoms. Results indicated that at both baseline and follow-up, the MTBI group had significantly slower reaction time than the HC group. Also, both the MTBI and HC groups had slower reaction times as participants progressed through each of the more challenging TAPI conditions. This study supports the usefulness of this novel instrument and allows clinicians and researchers to assess for subtle divided attention deficits that may persist in those with MTBI even three months post-injury. PMID:18609010

Paré, Nadia; Rabin, Laura A; Fogel, Joshua; Pépin, Michel

2009-01-01

404

Healing psychiatry: a pragmatic approach to bridging the science/humanism divide.  

Science.gov (United States)

Competing urges to think of human mental suffering as comprehensible and susceptible to scientific formulation, or as deeply complex and beyond the reach of scientific analysis, have torn at the fabric of psychiatry for many years and have left the field conceptually divided between science and humanism. Conceptual reparation of psychiatry is now a core mission of a field that is trying to heal itself so that it is equipped to heal the patients it serves. To formulate their cases comprehensively and provide patients with cutting-edge care, psychiatrists must heal the conceptual wounds that have resulted from dividing the human individual into an object of scientific scrutiny and a subject of personal experience. They must synthesize science and humanism in order to generate new understanding of mental disorders and to train future clinicians and researchers. Principles of classical American pragmatism, I argue in this article, can help to transcend the science/humanism divide in psychiatry. Clinical pragmatism focuses on favorable treatment outcomes by respecting the practical, pluralistic, participatory, and provisional aspects of psychiatric care. It demands that psychiatrists have the skill and flexibility to use multiple explanatory concepts in a collaborative, open-ended process with their patients. These themes are explored from the perspectives of contemporary psychiatric treatment, training, and research. PMID:15371070

Brendel, David

2004-01-01

405

Crossing the phantom divide in brane cosmology with curvature corrections and brane-bulk energy transfer  

International Nuclear Information System (INIS)

We consider the Randall-Sundrum brane-world model with bulk-brane energy transfer where the Einstein-Hilbert action is modified by curvature correction terms: a four-dimensional scalar curvature from induced gravity on the brane, and a five-dimensional Gauss-Bonnet curvature term. It is remarkable that these curvature terms will not change the dynamics of the brane universe at low energy. Parameterizing the energy transfer and taking the dark radiation term into account, we find that the phantom divide of the equation of state of effective dark energy could be crossed, without the need of any new dark energy components. Fitting the two most reliable and robust SNIa datasets, the 182 Gold dataset and the Supernova Legacy Survey (SNLS), our model indeed has a small tendency of phantom divide crossing for the Gold dataset, but not for the SNLS dataset. Furthermore, combining the recent detection of the SDSS baryon acoustic oscillations peak (BAO) with lower matter density parameter prior, we find that the SNLS dataset also mildly favors phantom divide crossing

406

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

407

77 FR 73049 - Notice of Availability of the Draft Environmental Impact Statement for the Continental Divide...  

Science.gov (United States)

...8,950 additional natural gas wells, including 100 to 500 coal bed natural gas wells, using a combination...would include well pads, gas and water collection pipelines, compressor stations, water disposal...

2012-12-07

408

Move of ground water  

International Nuclear Information System (INIS)

As a ground water flow which is difficult to explain by Darcy's theory, there is stagnant water in strata, which moves by pumping and leads to land subsidence. This is now a major problem in Japan. Such move on an extensive scale has been investigated in detail by means of 3H such as from rainfall in addition to ordinary measurement. The move of ground water is divided broadly into that in an unsaturated stratum from ground surface to water-table and that in a saturated stratum below the water-table. The course of the analyses made so far by 3H contained in water, and the future trend of its usage are described. A flow model of regarding water as plastic fluid and its flow as channel assembly may be available for some flow mechanism which is not possible to explain with Darcy's theory. (Mori, K.)

409

Uranium and radon in the ground water  

International Nuclear Information System (INIS)

The uranium (U) and the radon (Rn) concentrations in the Finnish groundwaters were studied and the results of the investigation are discussed in this article. The investigation comprises more than 10 000 water samples taken from drilled wells all over the country. The waters were divided into different groups by dominant rock type to establish the influence of the geological environment of the water

410

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

411

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.

412

Regional ground-water system  

International Nuclear Information System (INIS)

The Containment and Isolation Working Group considered issues related to the postclosure behavior of repositories in crystalline rock. This working group was further divided into subgroups to consider the progress since the 1978 GAIN Symposium and identify research needs in the individual areas of regional ground-water flow, ground-water travel time, fractional release, and cumulative release. The analysis and findings of the Ground-Water Regime Subgroup are presented

413

Asteroid Lightcurve Analysis at the Palmer Divide Observatory: 2011 March - July  

Science.gov (United States)

Lightcurves for 24 asteroids were obtained at the Palmer Divide Observatory (PDO) from 2011 March to July: 1355 Magoeba, 1727 Mette, 2048 Dwornik, 3022 Dobermann, (5639) 1989 PE, 6296 Cleveland, 6310 Jankonke, (6394) 1990 QM2, 6435 Daveross, 6859 Datemasamune, 10159 Tokara, (29242) 1992 HB4, (33324) 1998 QE56, (33679) 1999 JY107, (38047) 1998 TC3, (38048) 1998 UL18, (41424) 2000 CK40, (55854) 1996 VS1, (57784) 2001 VW85, (60335) 2000 AR42, (95147) 2002 AP166, (96327) 1997 EJ50, (97649) 2000 FK1, and (104998) 2000 KT2.

Warner, Brian D.

2011-10-01

414

Comparing Perception of Stroop Stimuli in Focused versus Divided Attention Paradigms: Evidence for Dramatic Processing Differences  

OpenAIRE

A huge set of focused attention experiments show that when presented with color words printed in color, observers report the ink color faster if the carrier word is the name of the color rather than the name of an alternative color, the Stroop effect. There is also a large number (although not so numerous as the Stroop task) of so-called “redundant targets studies” that are based on divided attention instructions. These almost always indicate that observers report the presence of a visual...

Eidels, Ami; Townsend, James T.; Algom, Daniel

2009-01-01

415

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)

416

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

417

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

Energy Technology Data Exchange (ETDEWEB)

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

Barton, C.E.; /Australian Natl. U., Canberra; Amory-Mazaudier, C.; /Lab.Phys.Plasmas, Saint Maur des Fosses; Barry, B.; /Assoc.African Univ., Accra; Chukwuma; /Olabisi Onabanjo U.; Cottrell, R.L.; /SLAC; Kalim, U.; /Pakistan Natl. U.; Mebrahtu, A.; /Mekelle U.; Petitdidier, M.; /Lab. d' Atmos., Velizy; Rabiu, B.; /Federal Tech. U., Akure; Reeves, C.; /Earthworks bv, Delft

2010-06-16

418

Penetration of a divided cystoperitoneal shunt catheter into the transverse colon inducing acute mastitis  

OpenAIRE

We report a rare case of acute mastitis caused by enteric organisms passing through a cystoperitoneal shunt catheter, which had penetrated into the colon. The patient is a 56-year-old woman who underwent shunt placement for cyst formation after surgery for meningioma at the age of 29. After 26 years, she suffered from a brain abscess and an attempt was made to surgically remove the indwelling catheter. Only part of the catheter could be removed, leaving a divided and ligated catheter in situ....

Shimodaira, Kentaro; Miyakura, Yasuyuki; Sadatomo, Ai; Miyazaki, Chieko; Sasanuma, Hideki; Koinuma, Koji; Horie, Hisanaga; Hozumi, Yasuo; Lefor, Alan T.; Yasuda, Yoshikazu

2013-01-01

419

Asteroid Lightcurve Analysis at the Palmer Divide Observatory: 2008 December - 2009 March  

Science.gov (United States)

Lightcurves for 34 asteroids were obtained at the Palmer Divide Observatory from 2008 December through 2009 March: 91 Aegina, 261 Prymno, 359 Georgia, 402 Chloe, 497 Iva, 506 Marion, 660 Crescentia, 691 Lehigh, 731 Sorga, 779 Nina, 802 Epyaxa, 908 Buda, 1015 Christa, 1518 Rovaniemi, 1600 Vyssotsky, 1656 Suomi, 2000 Herschel, 2735 Ellen, 3169 Ostro, 3854 George, 3940 Larion, (5558) 1989 WL2, (5747) 1991 CO3, 6517 Buzzi, (11304) 1993 DJ, (22195) 3509 P-L, (26383) 1999 MA2, (29780) 1999 CJ50, (45878) 2000 WX29, (45898) 2000 XQ49, (76800) 2000 OQ35, (76929) 2001 AX34, (87343) 2000 QH25, and (207398) 2006 AS2.

Warner, Brian D.

2009-07-01

420

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

421

Using a Divided Bar Apparatus to Measure Thermal Conductivity of Samples of Odd Sizes and Shapes  

Science.gov (United States)

Standard procedure for measuring thermal conductivity using a divided bar apparatus requires a sample that has the same surface dimensions as the heat sink/source surface in the divided bar. Heat flow is assumed to be constant throughout the column and thermal conductivity (K) is determined by measuring temperatures (T) across the sample and across standard layers and using the basic relationship Ksample=(Kstandard*(?T1+?T2)/2)/(?Tsample). Sometimes samples are not large enough or of correct proportions to match the surface of the heat sink/source, however using the equations presented here the thermal conductivity of these samples can still be measured with a divided bar. Measurements were done on the UND Geothermal Laboratories stationary divided bar apparatus (SDB). This SDB has been designed to mimic many in-situ conditions, with a temperature range of -20C to 150C and a pressure range of 0 to 10,000 psi for samples with parallel surfaces and 0 to 3000 psi for samples with non-parallel surfaces. The heat sink/source surfaces are copper disks and have a surface area of 1,772 mm2 (2.74 in2). Layers of polycarbonate 6 mm thick with the same surface area as the copper disks are located in the heat sink and in the heat source as standards. For this study, all samples were prepared from a single piece of 4 inch limestone core. Thermal conductivities were measured for each sample as it was cut successively smaller. The above equation was adjusted to include the thicknesses (Th) of the samples and the standards and the surface areas (A) of the heat sink/source and of the sample Ksample=(Kstandard*Astandard*Thsample*(?T1+?T3))/(?Tsample*Asample*2*Thstandard). Measuring the thermal conductivity of samples of multiple sizes, shapes, and thicknesses gave consistent values for samples with surfaces as small as 50% of the heat sink/source surface, regardless of the shape of the sample. Measuring samples with surfaces smaller than 50% of the heat sink/source surface resulted in thermal conductivity values which were too high. The cause of the error with the smaller samples is being examined as is the relationship between the amount of error in the thermal conductivity and the difference in surface areas. As more measurements are made an equation to mathematically correct for the error is being developed on in case a way to physically correct the problem cannot be determined.

Crowell, J. "; Gosnold, W. D.

2012-12-01

422

Crossing Boundaries : The Ethics of the Pubic/Private Divide in Migrant Domestic Work in Europe  

OpenAIRE

  The central objective of this thesis is to demonstrate how the concept—or concepts—of the public/private divide actively shapes the conditions of migrant domestic work in Europe. In doing so, I aim to show how European states’ current treatment of migrant domestic work is ethically problematic, and that a sufficient moral response to this dilemma entails a re-evaluation of any operative notions of the public/private distinction. The premise of my thesis is that migrants working as do...

Dios, Anjeline Eloisa J.

2009-01-01

423

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

424

A CRITICAL EVALUATION OF INDIAN GOVERNMENT’S STRATEGIES TO BRIDGE DIGITAL DIVIDE  

OpenAIRE

Emergence of Information and Communication Technology (ICT) has been a landmark for India. In one way, this sunshine sector has been instrumental in the economic growth of country and has glorified its image in the whole world but on the other end, it has also created a digital divide in our society. BBC's Jill McGivering reports that the IT revolution is only changing some lives in the world's largest democracy. (Bagla,2005) A small section of society is harnessing it fully for their advanta...

Bhatt, Nityesh

2006-01-01

425

High-impedance capacitive divider probe for potential measurements in plasmas  

International Nuclear Information System (INIS)

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

426

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

OpenAIRE

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 t...

Sebastian, A. J.

2009-01-01

427

Effects of nonlinear rheology, temperature and anisotropy on the relationship between age and depth at ice divides  

Directory of Open Access Journals (Sweden)

Full Text Available Ice flow in divide areas is strongly anisotropic. The evolution of ice fabric, from the onset of divide flow towards steady-state with a fully-developed fabric, has been shown to profoundly affect both the stratigraphy and surface topography of ice divides. Here, we investigate the effects of ice flow on the age-versus-depth relationship at ice divides by using a full Stokes thermomechanical model with a non-linear anisotropic constitutive relation between stress and strain rates. We compare our results with analytical approximations commonly employed in age–depth predictions such as the Dansgaard and Lliboutry approximations. We show that these approximations systematically underestimate the age of ice at fully-developed divides by as much as one order of magnitude. We also show that divides with fully-developed fabric are ideal locations for ice-core extraction because ice under them can be up to one order of magnitude older than ice at the same depth at the flanks. In addition, these divides have a distinctive morphological structure that allows them to be clearly identified from satellite imagery or ground-penetrating radar data. Our results are particularly relevant in coastal areas of Antarctica where divides with fully-developed ice fabric are widespread.

C. Martín

2012-06-01

428

Structure and fluid migration in a Late Cenozoic duplex system forming the Main Divide in the central Southern Alps, New Zealand  

International Nuclear Information System (INIS)

The Alpine Schist immediately west of the Main Divide of the Southern Alps is a west-dipping duplex system consisting of an imbricated stack of rock slabs, each c. 250-1000 m thick. The imbricated stack has low grade, little deformed pumpellyite-actinolite facies semischists at the base, overlain by progressively higher grade and more deformed schists. The structurally highest slab mapped consists of multiply-deformed biotite zone schist. The duplex lies on the hanging wall of the northwest-dipping Main Divide Fault Zone, which separates semischist from structurally underlying greywacke. Rock slabs are internally disrupted by faults subparallel to layering, and consist of lozenge-shaped blacks of 10-100 m. Fault zones separating rock slabs consist of 18O(SMOW) between 11.4 and 26.1 per thousand, and ?13C(PDB) between -.6 and -11.4 per thousand. Calculated isotopic ratios for the mineralising fluids show little evidence for meteoric origin. The fluid may be meteoric water which has undergone isotopic exchange with host rocks, metamorphic water, or a mixture of these, and mineralisation occurred during rise of the fluids from depth. (author). 56 refs., 12 figs., 3 tabs

429

Global digital divide: determinants of cross-country ICT development with special reference to Southeast Asia  

Directory of Open Access Journals (Sweden)

Full Text Available Information and communication technology (ICT tools are regarded as imperative not only for enabling the economy to grow at a healthy rate, but also for elevating the socioeconomic conditions and standards of the society. In concurrence with the widespread diffusion of ICT, lies the phenomenon called digital divide – a complex issue pertaining to unequal access, use and applications of ICT among countries and peoples. This paper attempts to measure the contribution of conventional factors such as affordability, infrastructure, trade openness and urbanization, with added emphasis on the role of financial development in explaining cross-country development of ICT among Southeast Asian countries. Using panel data for 4 countries for the period 1994 – 2011, findings of this study revealed that GDP is the most significant determinant in explaining digital divide – consistent with findings from previous research efforts. Financial development also appear significant in most models adopted in all three ICT tools, implying the need for these countries to improve their financial markets to avoid falling further behind in promoting a digitally inclusive society.

Debbra Toria Nipo

2014-09-01

430

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

Directory of Open Access Journals (Sweden)

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

Yan Liu

2013-07-01

431

Information Resources Column: "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.

Schloman, B

2004-05-01

432

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

Science.gov (United States)

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

Rohaly, Ann M.; Karsh, Robert

1998-07-01

433

Ensemble Kalman Filtering with a Divided State-Space Strategy for Coupled Data Assimilation Problems*  

Science.gov (United States)

This study considers the data assimilation problem in coupled systems, which consists of two components (sub-systems) interacting with each other through certain coupling terms. A straightforward way to tackle the assimilation problem in such systems is to concatenate the states of the sub-systems into one augmented state vector, so that a standard ensemble Kalman filter (EnKF) can be directly applied. In this work we present a divided state-space estimation strategy, in which data assimilation is carried out with respect to each individual sub-system, involving quantities from the sub-system itself and correlated quantities from other coupled sub-systems. On top of the divided state-space estimation strategy, we also consider the possibility to run the sub-systems separately. Combining these two ideas, a few variants of the EnKF are derived. The introduction of these variants is mainly inspired by the current status and challenges in coupled data assimilation problems, and thus might be of interest from a practical point of view. Numerical experiments with a multi-scale Lorentz 96 model are conducted to evaluate the performance of these variants against that of the conventional EnKF. In addition, specific for coupled data assimilation problems, two prototypes of extensions of the presented methods are also developed in order to achieve a trade-off between efficiency and accuracy.

Luo, Xiaodong; Hoteit, Ibrahim

2014-12-01

434

Action spectra for killing non-dividing normal human and Xeroderma pigmentosum cells  

International Nuclear Information System (INIS)

Non-dividing human cells degenerate and eventually detach from a culture vessel surface when exposed to UV light. Action spectra for this kind of cell inactivation were determined using eight monochromatic wavelengths from 240 to 313 nm and both a normal DNA excision-repair-proficient strain and repair-deficient Xeroderma pigmentosum (XP12BE) strain. The action spectra for both strains have similar shapes with a broad peak between 254 and 280 nm followed by a steep decline at wavelengths greater than 280 nm. The relative action spectra are similar to those for inactivation of reproductive capacity and pyrimidine dimer formation in rodent cells suggesting that the critical target and critical damage for inactivation of non-dividing human cells is DNA and damage to DNA, respectively. Normal repair-proficient cells are 5-7 times more resistant at all wavelengths, based on a comparison of Dsub(o) values, than repair-deficient XP12BE cells, supporting the conclusion that the inactivating damage at all wavelengths is to DNA. (author)

435

Using Photobleaching to Measure Spindle Microtubule Dynamics in Primary Cultures of Dividing Drosophila Meiotic Spermatocytes  

Science.gov (United States)

In dividing animal cells, a microtubule (MT)-based bipolar spindle governs chromosome movement. Current models propose that the spindle facilitates and/or generates translocating forces by regionally depolymerizing the kinetochore fibers (k-fibers) that bind each chromosome. It is unclear how conserved these sites and the resultant chromosome-moving mechanisms are between different dividing cell types because of the technical challenges of quantitatively studying MTs in many specimens. In particular, our knowledge of MT kinetics during the sperm-producing male meiotic divisions remains in its infancy. In this study, I use an easy-to-implement photobleaching-based assay for measuring spindle MT dynamics in primary cultures of meiotic spermatocytes isolated from the fruit fly Drosophila melanogaster. By use of standard scanning confocal microscopy features, fiducial marks were photobleached on fluorescent protein (FP)-tagged MTs. These were followed by time-lapse imaging during different division stages, and their displacement rates were calculated using public domain software. I find that k-fibers continually shorten at their poles during metaphase and anaphase A through the process of MT flux. Anaphase chromosome movement is complemented by Pac-Man, the shortening of the k-fiber at its chromosomal interface. Thus, Drosophila spermatocytes share the sites of spindle dynamism and mechanisms of chromosome movement with mitotic cells. The data reveal the applicability of the photobleaching assay for measuring MT dynamics in primary cultures. This approach can be readily applied to other systems. PMID:25802491

2015-01-01

436

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

International Nuclear Information System (INIS)

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

437

Novel single-mode asymmetric Y-branches for 3-dB power divider  

Science.gov (United States)

A wide-angle single-mode 3-dB asymmetric Y-junction with a microprism is proposed. Symmetric Y-branches, useful for equal power splitting, have been widely investigated by various authors. Asymmetric Y-branches, however, are not as well studied as their symmetric counterparts. In this paper, the phase front mismatch caused by asymmetric branching will be discussed. The microprism is designed by its phase compensation rule (PCR), the phase front mismatch at the branching point is greatly eliminated, and the structure of the microprism can be varied in fixed microprism length or fixed index. By utilizing the PCR we proposed, each branch arm will have equal power. A conventional asymmetric Y-branch can be utilized as a 3-dB divider only under small and specific branching angles. To remove this disadvantage, a novel asymmetric Y-branch with microprism is proposed. This structure can divide the optical power almost equally into output branches under large-angle. Because the difference between the index of the film and the index of the substrate is very small, the proposed structure is weakly guiding. Therefore, device performance examined numerically by the semivectorial finite difference beam propagation method (SVFD- BPM) should be acceptable and always kept at satisfactory levels in this paper.

Lien, June-Hung; Lin, Han-Bin; Chang, Wen-Ching; Tsai, Pei-Shan

2000-10-01

438

Controlling hollow relativistic electron beam orbits with an inductive current divider  

Science.gov (United States)

A passive method for controlling the trajectory of an intense, hollow electron beam is proposed using a vacuum structure that inductively splits the beam's return current. A central post carries a portion of the return current (I1), while the outer conductor carries the remainder (I2). An envelope equation appropriate for a hollow electron beam is derived and applied to the current divider. The force on the beam trajectory is shown to be proportional to (I2-I1), while the average force on the envelope (the beam width) is proportional to the beam current Ib = (I2 + I1). The values of I1 and I2 depend on the inductances in the return-current path geometries. Proper choice of the return-current geometries determines these inductances and offers control over the beam trajectory. Solutions using realistic beam parameters show that, for appropriate choices of the return-current-path geometry, the inductive current divider can produce a beam that is both pinched and straightened so that it approaches a target at near-normal incidence with a beam diameter that is on the order of a few mm.

Swanekamp, S. B.; Richardson, A. S.; Angus, J. R.; Cooperstein, G.; Hinshelwood, D. D.; Ottinger, P. F.; Rittersdorf, I. M.; Schumer, J. W.; Weber, B. V.; Zier, J. C.

2015-02-01

439

Handling zone dividing method in packed bed liquid desiccant dehumidification/regeneration process  

International Nuclear Information System (INIS)

Dehumidifier and regenerator are the most significant components in liquid desiccant air-conditioning systems, in which air directly contacts liquid desiccant and heat and mass transfer process occurs between the two fluids. Heat transfer process and mass transfer process within dehumidifier/regenerator influence each other and should not be separately considered. Based on the previous reachable handling region analysis, a zonal method is proposed in present study. Four zones are divided in the psychrometric chart according to the relative position of inlet air to inlet desiccant including two dehumidification zones, zone A and zone D, and two regeneration zones, zone B and zone C. In zone A or C, mass transfer is key process, and counter-flow configuration has the best mass transfer performance and parallel-flow is the poorest in the same operating conditions. In zone B or D, heat transfer is governing process, parallel-flow has the best mass transfer performance and counter-flow is the poorest. In order to obtain better mass transfer performance, liquid desiccant should be cooled (in zone A) rather than air (in zone D) in dehumidifier, and liquid desiccant should be heated (in zone C) rather than air (in zone B) in regenerator. The divided zones and the corresponding zonal properties will be helpful to the design and optimization of dehumidifiers and regenerators.

440

Clinical psychology and disability studies: bridging the disciplinary divide on mental health and disability.  

Science.gov (United States)

Abstract Purpose: Clinical psychology and disability studies have traditionally occupied very different academic, philosophical and political spaces. However, this paper aims to illustrate the positive consequences and implications of attempts to understand and bridge this disciplinary divide. Method: A narrative review format was used with evidence selected pragmatically as opposed to systematically. The construction of the argument determined the evidence selected. Results: The concept of psycho-emotional disablism, which originated within disability studies, is argued to be a useful concept to bridge the divide between understandings of distress from both disability studies and clinical psychology perspectives. However, this can be usefully augmented by psychological research on the mechanisms through which disablism can affect individuals. Conclusion: Perspectives from both disability studies and clinical psychology can be usefully combined to bring important new perspectives; combined, these perspectives should help - on theoretical, service and social levels - to improve the mental health of disabled people. Implications for Rehabilitation Mental health is an important determinant of overall health-related quality of life and psychological therapy should be available for those disabled people who would value it. Psychological therapists working with disabled people should be more aware of the challenging social context in which disabled people live. Understandings of distress should not just include individual factors but also incorporate the psychological impact of stresses caused by societal barriers preventing inclusion. Psychologists should be more willing to work and engage at a societal and political level to influence change. PMID:25243770

Simpson, Jane; Thomas, Carol

2014-09-22

441

Sector Dividing Method in Enroute Radar Airspace with Unbalanced Traffic Distribution  

Directory of Open Access Journals (Sweden)

Full Text Available In order to effectively meet the traffic demand changes in time and space, based on the multi-controller team, an adaptive airspace sector boundaries dividing method was proposed.First,the target airspace was processed with grid.Statistics of average distribution of the aircraft number for each grid, revised by adding the distribution coefficients of aircraft number which measure the (Air Traffic ControllerATC additional workload associating with coordinating, handover and resolve conflicts, alluding to each grid.the multi Huolang backpack method was used to group grids.This method ensure that the aircraft count does not exceed the monitor alert parameter(MAP.On this basis, rules which try to avoid increasing ATC workload was used to divide sector boundaries. Monitor alert parameters taking a value which is much bigger than median ensure that the the foundation sectors have more adaptability and security,as well controllers will not need additional training to adapt to changes in the sector range. The dynamic reaction logic control designed effective monitoring could effectively monitor MAP in plan time.Test results show that the higher the frequency of the dynamic response, the average number of aircraft in the sector of 15 minutes will be more closer MAP.

Zhijian Ye

2013-06-01

442

E-GOVERNMENT AND GENDER DIGITAL DIVIDE: THE CASE OF JORDAN  

Directory of Open Access Journals (Sweden)

Full Text Available There is an indicator that e-Government projects have gabs in dealing with gender digital divide especially in developing countries and rural areas in industrialized countries. This research aims to review experiences on integration of gender equality issues with e-Government projects all over the world, and introduce justifications for the need of poor women to access e-Government information and services. Jordan embarked on many initiatives that are related to women and rural areas development and support. This research explores all previously mentioned initiatives to suggest how e-Government project in Jordan can empower poor women in rural areas with minimal or no ICT skills, and with no computers or Internet at their homes. This study interviewed fifty women who utilized support from previously mentioned foundations and concluded that e-Government project in Jordan did not reach the required level of service towards helping in bridging the gender divide and help poor women improve their lives. Conclusions and future work are stated at the end.

Boran A. AL-Rababah

2010-01-01

443

The influence of thematic congruency, typicality and divided attention on memory for radio advertisements.  

Science.gov (United States)

We examined the effects of the thematic congruence between ads and the programme in which they are embedded. We also studied the typicality of the to-be-remembered information (high- and low-typicality elements), and the effect of divided attention in the memory for radio ad contents. Participants listened to four radio programmes with thematically congruent and incongruent ads embedded, and completed a true/false recognition test indicating the level of confidence in their answer. Half of the sample performed an additional task (divided attention group) while listening to the radio excerpts. In general, recognition memory was better for incongruent ads and low-typicality statements. Confidence in hits was higher in the undivided attention group, although there were no differences in performance. Our results suggest that the widespread idea of embedding ads into thematic-congruent programmes negatively affects memory for ads. In addition, low-typicality features that are usually highlighted by advertisers were better remembered than typical contents. Finally, metamemory evaluations were influenced by the inference that memory should be worse if we do several things at the same time. PMID:23947823

Martín-Luengo, Beatriz; Luna, Karlos; Migueles, Malen

2014-01-01

444

Metacognition of multitasking: How well do we predict the costs of divided attention?  

Science.gov (United States)

Risky multitasking, such as texting while driving, may occur because people misestimate the costs of divided attention. In two experiments, participants performed a computerized visual-manual tracking task in which they attempted to keep a mouse cursor within a small target that moved erratically around a circular track. They then separately performed an auditory n-back task. After practicing both tasks separately, participants received feedback on their single-task tracking performance and predicted their dual-task tracking performance before finally performing the 2 tasks simultaneously. Most participants correctly predicted reductions in tracking performance under dual-task conditions, with a majority overestimating the costs of dual-tasking. However, the between-subjects correlation between predicted and actual performance decrements was near 0. This combination of results suggests that people do anticipate costs of multitasking, but have little metacognitive insight on the extent to which they are personally vulnerable to the risks of divided attention, relative to other people. PMID:24490818

Finley, Jason R; Benjamin, Aaron S; McCarley, Jason S

2014-06-01

445

Randomly dividing homologous samples leads to overinflated accuracies for emotion recognition.  

Science.gov (United States)

There are numerous studies measuring the brain emotional status by analyzing EEGs under the emotional stimuli that have occurred. However, they often randomly divide the homologous samples into training and testing groups, known as randomly dividing homologous samples (RDHS), despite considering the impact of the non-emotional information among them, which would inflate the recognition accuracy. This work proposed a modified method, the integrating homologous samples (IHS), where the homologous samples were either used to build a classifier, or to be tested. The results showed that the classification accuracy was much lower for the IHS than for the RDHS. Furthermore, a positive correlation was found between the accuracy and the overlapping rate of the homologous samples. These findings implied that the overinflated accuracy did exist in those previous studies where the RDHS method was employed for emotion recognition. Moreover, this study performed a feature selection for the IHS condition based on the support vector machine-recursive feature elimination, after which the average accuracies were greatly improved to 85.71% and 77.18% in the picture-induced and video-induced tasks, respectively. PMID:25712913

Liu, Shuang; Zhang, Di; Xu, Minpeng; Qi, Hongzhi; He, Feng; Zhao, Xin; Zhou, Peng; Zhang, Lixin; Ming, Dong

2015-04-01

446

The Digital Health Divide: Evaluating Online Health Information Access and Use Among Older Adults  

Science.gov (United States)

Objective Innovations in health information technology (HIT) provide opportunities to reduce health care spending, improve quality of care, and improve health outcomes for older adults. However, concerns relating to older adults’ limited access and use of HIT, including use of the Internet for health information, fuel the digital health divide debate. This study evaluated the potential digital health divide in relation to characteristic and belief differences between older adult users and nonusers of online health information sources. Methods A cross-sectional survey design was conducted using a random sample of older adults. A total of 225 older adults (age range = 50–92 years, M = 68.9 years, SD = 10.4) participated in the study. Results Seventy-six percent of all respondents had Internet access. Users and nonusers of online health information differed significantly on age (M = 66.29 vs. M = 71.13), education, and previous experience with the health care system. Users and nonusers of online health information also differed significantly on Internet and technology access, however, a large percentage of nonusers had Internet access (56.3%), desktop computers (55.9%), and laptop computers or netbooks (43.2%). Users of online health information had higher mean scores on the Computer Self-Efficacy Measure than nonusers, t(159) = ?7.29, p education programs to promote HIT use among older adults. PMID:25156311

Hall, Amanda K.; Bernhardt, Jay M.; Dodd, Virginia; Vollrath, Morgan W.

2015-01-01

447

Ensemble Kalman Filtering with a Divided State-Space Strategy for Coupled Data Assimilation Problems  

KAUST Repository

This study considers the data assimilation problem in coupled systems, which consists of two components (subsystems) interacting with each other through certain coupling terms. A straightforward way to tackle the assimilation problem in such systems is to concatenate the states of the subsystems into one augmented state vector, so that a standard ensemble Kalman filter (EnKF) can be directly applied. This work presents a divided state-space estimation strategy, in which data assimilation is carried out with respect to each individual subsystem, involving quantities from the subsystem itself and correlated quantities from other coupled subsystems. On top of the divided state-space estimation strategy, the authors also consider the possibility of running the subsystems separately. Combining these two ideas, a few variants of the EnKF are derived. The introduction of these variants is mainly inspired by the current status and challenges in coupled data assimilation problems and thus might be of interest from a practical point of view. Numerical experiments with a multiscale Lorenz 96 model are conducted to evaluate the performance of these variants against that of the conventional EnKF. In addition, specific for coupled data assimilation problems, two prototypes of extensions of the presented methods are also developed in order to achieve a trade-offbetween efficiency and accuracy.

Luo, Xiaodong

2014-12-01

448

Ensemble Kalman filtering with a divided state-space strategy for coupled data assimilation problems  

CERN Document Server

This study considers the data assimilation problem in coupled systems, which consists of two components (sub-systems) interacting with each other through certain coupling terms. A straightforward way to tackle the assimilation problem in such systems is to concatenate the states of the sub-systems into one augmented state vector, so that a standard ensemble Kalman filter (EnKF) can be directly applied. In this work we present a divided state-space estimation strategy, in which data assimilation is carried out with respect to each individual sub-system, involving quantities from the sub-system itself and correlated quantities from other coupled sub-systems. On top of the divided state-space estimation strategy, we also consider the possibility to run the sub-systems separately. Combining these two ideas, a few variants of the EnKF are derived. The introduction of these variants is mainly inspired by the current status and challenges in coupled data assimilation problems, and thus might be of interest from a pr...

Luo, Xiaodong

2014-01-01

449

Application of partially diabatic divided wall column to floating liquefied natural gas plant  

International Nuclear Information System (INIS)

The offshore operation of chemical plant requires the compactness of process equipments due to its harsh environment. A DWC (divided wall column), a compact ternary separator, is a good candidate for distillation process in the offshore operation. In this study the DWC is applied to the offshore FLNG (floating liquefied natural gas) plant, but high utility cost is required in the application because of the large difference of boiling points among feed components. A partially diabatic DWC is proposed for the reduction of the operating cost here, and its design procedure is presented along with performance and economic evaluations and the examination of thermodynamic efficiency as well. The heating duty of the proposed DWC including tray heat transfer is 35% less than that of the conventional system, and the cooling duty is 18% less. The evaluation indicates that some 16% less utility cost is used in the DWC compared with the conventional system, though 7% more investment is required. The exergy loss is reduced by 12%, and the thermodynamic efficiency is improved by 3.3 percentage point over the conventional system. - Highlights: • Diabatic divided wall column for FLNG (floating liquefied natural gas) plant. • Compact column for offshore operation. • 35% less heating duty required. • 16% lower utility necessary. • Exergy loss reduced by 12%

450

A high linearity current mode multiplier/divider with a wide dynamic range  

International Nuclear Information System (INIS)

A high linearity current mode multiplier/divider (CMM/D) with a wide dynamic range is presented. The proposed CMM/D is based on the voltage—current characteristic of the diode, thus wide dynamic range is achieved. In addition, high linearity is achieved because high accuracy current mirrors are adopted and the output current is insensitive to the temperature and device parameters of the fabrication process. Furthermore, no extra bias current for all input signals is required and thus power saving is realized. With proper selection of establishing the input terminal, the proposed circuit can perform as a multifunction circuit to be operated as a multiplier/divider, without changing its topology. The proposed circuit is implemented in a 0.25 ?m BCD process and the chip area is 0.26 × 0.24 mm2. The simulation and measurement results show that the maximum static linearity error is ±1.8% and the total harmonic distortion is 0.4% while the input current ranges from 0 to 200 ?A. (semiconductor integrated circuits)

451

Dividing by four CO2 releases due to energy: the Negatep scenario  

International Nuclear Information System (INIS)

The Negatep scenario aims at dividing CO2 releases by 4, which means, more or less, dividing the consumption of fossil energies by the same factor, in order to comply with the French 2005 energy act. After a description of the situation in 2006, of trends, and a recall of the objectives defined by the 'Grenelle de l'Environnement' regarding energy savings and renewable energies, the authors show that reaching such a reduction requires to: decrease to nearly zero oil and gas in the residential and tertiary sectors, reduce significantly the use of oil in the transport sector, reduce significantly the use of fossil fuels in industry, increase massively the share of electricity in the energy mix, maintain the share of nuclear in the electricity generation and, as long as the storage of electricity is not developed, limit the share of intermittent energies to a level compatible with that of gas turbines. The study shows that the proposed measures can fulfill the objectives for 2020 proposed by the 'Grenelle de l'Environnement'

452

Decolorization and mineralization of Orange G azo dye solutions by anodic oxidation with a boron-doped diamond anode in divided and undivided tank reactors  

International Nuclear Information System (INIS)

Highlights: • Acidic Orange G azo dye solutions completely degraded by anodic oxidation with BDD. • Quicker decolorization and mineralization in a divided than an undivided cell. • Similar time needed for total decolorization and disappearance of Orange G. • Maleic, tartronic, acetic, formic, oxalic and oxamic acids as generated carboxylic acids. • Ammonium and sulfate as main inorganic ions released during dye mineralization. - Abstract: The decolorization and mineralization of 100 cm3 of 0.52-6.34 mmol dm?3 Orange G azo dye solutions at pH 3.0 and current density between 33.3 and 150 mA cm?2 have been studied by anodic oxidation (AO) using a divided or undivided tank reactor with a boron-doped diamond (BDD) anode and a stainless steel cathode. In both systems, organics were destroyed by hydroxyl radicals generated at the BDD anode from water oxidation. Solutions with 0.52 mmol dm?3 of the dye were completely decolorized in both cells, more rapidly at greater current density. The divided cell always gave faster decolorization than the undivided one. Overall mineralization in the divided tank reactor was attained in less than 330 min operating at current densities ? 66.7 mA cm?2, whereas in the undivided cell, this was feasible at times as long as 420 min for 150 mA cm?2. For Orange G contents up to 6.34 mmol dm?3, total mineralization at 100 mA cm?2 was also more easily reached in the divided cell. The mineralization current efficiency always rose at lower current density and higher dye content. The dye decayed obeying a pseudo-first-order kinetics and its apparent rate constant increased at higher current density. A similar electrolysis time was required for total decolorization and disappearance of Orange G, indicating that aromatic by-products were rapidly destroyed and did not accumulate in the medium. Final carboxylic acids like maleic, tartronic, acetic, formic, oxalic and oxamic were generated, whereas ammonium and sulfate were the main inorganic ions released during Orange G mineralization

453

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

Directory of Open Access Journals (Sweden)

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

Segarani Naidoo

2012-12-01

454

Gold mineralisation near the Main Divide, upper Wilberforce valley, Southern Alps, New Zealand  

International Nuclear Information System (INIS)

Veins up to 8 m wide fill extensional fractures in Torlesse Terrane metasediments near the Main Divide in the upper Wilberforce valley, Canterbury, New Zealand. The upper Wilberforce veins are part of a prominent 40 km long, NNE-trending swarm of gold-bearing veins formed across the Main Divide during the Late Cenozoic rise of the Southern Alps. The veins occur within, and near, a prominent set of faults which constitute the Main Divide Fault Zone. The veins are irregular in shape due to contrasting host rock properties, and have been only weakly sheared and deformed. Veins cut across greywacke beds and follow irregularly along argillite beds, on the 1-10 m scale. Quartz dominates vein mineralogy, but albite forms up to 45% of some veins, and minor chlorite, pyrite, arsenopyrite, chalcopyrite, and gold occur sporadically, especially in breccias near vein margins. Fluid inclusions in vein quartz homogenise at 180-253 degrees C, and arsenopyrite composition (28.3-30.8 at.% As) suggest formation temperatures of 250-350 degrees C. Elevated arsenic levels (up to 200 ppm above a background of 10 ppm) in some host greywackes and argellites suggest that hydrothermal activity pervaded host rocks as well as forming veins, but there is no textural evidence for this fluid flow. Late-stage carbonates in faults adjacent to the quartz veins, but which postdate the quartz veins, have ?18O ranging from 11.1 to 25.6 per thousand, and ?13C ranging from -12.5 to - ?13C ranging from -12.5 to -1.1 per thousand. These carbonates were deposited by a mixture of meteoric and crustally isotopically exchanged fluid as a shallow-level manifestation of the same hydrothermal system which deposited the quartz veins. The upper Wilberforce veins structurally and mineralogically resemble some Late Cenozoic gold-bearing vein systems in the Mt Cook area, 100 km to the southwest along the Southern Alps. (author). 52 refs., 9 figs., 3 tabs

455

New Frontiers in the Digital Divide : Revisiting Policy for Digital Inclusion  

DEFF Research Database (Denmark)

In a new strategy for e-government, the Danish government set the goal that in 2015 all contacts between citizens and public authorities must be conducted electronically. In accordance with EU’s strategy for e-government every citizen ought to have equal access to public services, hence the question is: How to form a policy for digital inclusion where nobody is left behind? In continuation of the EU policy it seems reasonable to argue that the public authorities now has an obligation to ‘dress up’ the citizens to serve themselves through the public e-services. Hence, policies and actions for digital inclusion becomes a central theme for the implementation of the new e-government strategy. Until now it has been voluntary whether or not citizens want to use ICT and a lot of especially senior citizens have chosen not to use the technology. However, senior citizens are not the only group affected of the e-government strategy. New frontiers in the digital divide are opening and a new group of excluded become visible: the youngsters. In this way, one of the leading Danish newspapers reports that young people lines up in town halls to get help to fill out forms, which are already available on the internet. The analysis in this paper is based on a multidisciplinary theoretical approach drawing on theories of the digital divide, theories of domestication of technology, and theories about the interplay between users and technology developed in the field of STS (Science, Technology and Society). In continuation of this theoretical framework the analysis is conducted as a mixed methods research where different kinds of knowledge are included. Hence, to analyze the Danish digital divide I draw on statistics developed by Statistics Denmark – the national agency for statistic – as well as a comprehensive qualitative study of senior citizens’ usage of ICT (Jæger, 2005). For the analysis of the policy I draw on a literature study of policy papers (Jæger & Löfgren 2010) as well as six qualitative interviews with key politicians – including the Minister of Science and Technology – and key civil servant.

Jæger, Birgit

456

Effects of nonlinear rheology, temperature and anisotropy on the relationship between age and depth at ice divides  

Directory of Open Access Journals (Sweden)

Full Text Available Ice flow in divide areas is strongly anisotropic. The evolution of ice fabric, from the onset of divide flow towards steady state with a fully developed fabric, has been shown to profoundly affect both the stratigraphy and surface topography of ice divides. Here, we investigate the effects of ice flow on the age-versus-depth relationship at ice divides by using a full Stokes thermomechanical model with a non-linear anisotropic constitutive relation between stress and strain rates. We compare our results with analytical approximations commonly employed in age–depth predictions, such as the Dansgaard and Lliboutry approximations. We show that these approximations systematically underestimate the age of ice at fully developed divides by as much as one order of magnitude. We also show that divides with fully developed fabric are ideal locations for ice-core extraction because ice under them can be up to one order of magnitude older than ice at the same depth at the flanks. In addition, these divides have a distinctive morphological structure that allows them to be clearly identified from satellite imagery or ground-penetrating radar data.

C. Martín

2012-10-01

457

[Spectral baseline correction by piecewise dividing in Fourier transform infrared gas analysis].  

Science.gov (United States)

Aimed at the problem that baseline drift or distortion often appears in Fourier transform spectra after spectrometer has continuously worked for a long time, baseline variation caused by IR source temperature drift and fluctuation, tilt of moving mirror, performance parameter change of beam splitter and lateral shift of detector were studied by simulating using MATLAB. Simulation results show that spectral baseline drift is approximately linear. On this basis, a novel method named spectral baseline correction by piecewise dividing (SBCPD) is proposed to correct spectral baseline in the present work By comparing peak height of simulated spectra, it was found that performance of SBCPD is better than that of common methods of polynomial fitting, air-PLS (adaptive iteratively reweighted Penalized Least Squares). And the application in gas well-logging showed that prediction accuracy of SBCPD is also higher. Additionally, this method is reliable and of less calculation, and is suitable for engineering application. PMID:23697106

Tang, Xiao-Jun; Wang, Jin; Zhang, Lei; Guan, Jin-Feng; Zhang, Yong; Liu, Jun-Hua

2013-02-01

458

Spectroscopic measurements with a silicon drift detector having a continuous implanted drift cathode-voltage divider  

International Nuclear Information System (INIS)

A silicon drift detector (SDD) prototype where the drift electrode also plays the role of a high-voltage divider has been realised and characterised for spectroscopic applications at near-room temperatures. Among the advantages of this design, is the absence of metal on the sensitive surface which makes this detector interesting for soft X-rays. The detector prototype has a large sensitive area (2x130 mm2) and the charge is collected by two anodes (butterfly-like detector). The energy resolution of a such a detector has been investigated at near-room temperatures using a commercial, hybrid, low-noise charge-sensitive preamplifier. The results obtained for the X-ray lines from 55Fe and 241Am are presented

459

Spectroscopic measurements with a silicon drift detector having a continuous implanted drift cathode-voltage divider  

Energy Technology Data Exchange (ETDEWEB)

A silicon drift detector (SDD) prototype where the drift electrode also plays the role of a high-voltage divider has been realised and characterised for spectroscopic applications at near-room temperatures. Among the advantages of this design, is the absence of metal on the sensitive surface which makes this detector interesting for soft X-rays. The detector prototype has a large sensitive area (2x130 mm{sup 2}) and the charge is collected by two anodes (butterfly-like detector). The energy resolution of a such a detector has been investigated at near-room temperatures using a commercial, hybrid, low-noise charge-sensitive preamplifier. The results obtained for the X-ray lines from {sup 55}Fe and {sup 241}Am are presented.

Bonvicini, V. E-mail: bonvicini@trieste.infn.it; Burger, P.; D' Acunto, L.; Franck, D.; Gregorio, A.; Pihet, P.; Rashevsky, A.; Vacchi, A.; Vinogradov, L.; Zampa, N

2000-01-11

460

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

Science.gov (United States)

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

Warner, Brian D.

2013-04-01

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