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1

Isostables, isochrons, and Koopman spectrum for the action–angle representation of stable fixed point dynamics  

NASA Astrophysics Data System (ADS)

For asymptotically periodic systems, a powerful (phase) reduction of the dynamics is obtained by computing the so-called isochrons, i.e. the sets of points that converge toward the same trajectory on the limit cycle. Motivated by the analysis of excitable systems, a similar reduction has been attempted for non-periodic systems admitting a stable fixed point. In this case, the isochrons can still be defined but they do not capture the asymptotic behavior of the trajectories. Instead, the sets of interest–that we call "isostables"–are defined in the literature as the sets of points that converge toward the same trajectory on a stable slow manifold of the fixed point. However, it turns out that this definition of the isostables holds only for systems with slow–fast dynamics. Also, efficient methods for computing the isostables are missing.

Mauroy, A.; Mezi?, I.; Moehlis, J.

2013-10-01

2

SIX FUNCTIONALS FIXED POINT THEOREM  

Microsoft Academic Search

The Six Functionals Fixed Point Theorem is a generalization of the Five Functionals Fixed Point Theorem as well as the original triple xed point theorem of Leggett-Williams. In the Six Functionals Fixed Point Theorem, none of the functional boundaries are required to map above or below the boundary in the functional sense. As an application, the existence of at least

RICHARD AVERY; JOHNNY HENDERSON

2008-01-01

3

Fixed Points of Analytic Functions.  

National Technical Information Service (NTIS)

A continuous mapping of a simply connected, closed, bounded set of the Euclidean plane into itself is known to have at least one fixed point. It is shown that the usual condition for the fixed point to be unique, and for convergence of the iteration seque...

P. Henrici

1969-01-01

4

Logistic Map Fixed Points Model  

NSDL National Science Digital Library

The Logistic Map Fixed Points Model finds periodic trajectories of the logistic map such that n iterations of the map starting with an initial value x return to that value. The key idea for this model is that for values of the logistic map control parameter r in the chaotic regime, there are periodic but unstable trajectories. This property of the chaotic regime means that if we choose the value of the seed x0 to be precisely equal to a point on an unstable trajectory with period n, the subsequent trajectory will have this period. However, if we choose a value of x0 that differs ever so slightly from this special value, the trajectory will not be periodic. This model shows how to find these special values of x0. The Logistic Map Fixed Points Model was created using the Easy Java Simulations (EJS) modeling tool. It is distributed as a ready-to-run (compiled) Java archive. Double clicking the ejs_chaos_LogisticMapFixedPoints.jar file will run the program if Java is installed.

Christian, Wolfgang

2012-01-29

5

Simple currents, modular invariants and fixed points  

SciTech Connect

This paper reviews the use of simple currents in constructing modular invariant partition functions and the problem of resolving their fixed points. The authors present some new results, in particular regarding fixed point resolution. Additional empirical evidence is provided in support of the conjecture that fixed point conformal field theories for all simply laced and most non-simply laced Kac-Moody algebras, for which the fixed point CFT's turn out to be Kac-Moody algebras themselves. For the remaining non-simply laced ones we obtain spectra that appear to correspond to new non-unitary conformal field theories. The fusion rules of the simplest unidentified example are computed.

Schellekens, A.N. (CERN, 1211 Geneva 23 (CH)); Yankielowicz, S. (School of Physics and Astronomy, Tel-Aviv Univ., Tel-Aviv 69978 (IL))

1990-08-10

6

Branes and six dimensional fixed points  

Microsoft Academic Search

We analyze brane configurations corresponding to non-trivial six dimensional fixed points. Several results previously obtained from a pure field theoretical analysis are rederived in the brane language.

Ilka Brunner; Andreas Karch

1997-01-01

7

The DSP decision: fixed point or floating?  

Microsoft Academic Search

The rapid expansion of the market in applications of the digital signal processor has unloosed a flood of diverse chips. Design engineers are being inundated with altogether too much information to absorb. Still, the problem does become more manageable once it is decided whether a fixed-point or a floating point math unit should be basic to the digital signal processor

C. Inacio; D. Ombres

1996-01-01

8

Fixed Points of the Dissipative Hofstadter Model  

SciTech Connect

The phase diagram of a dissipative particle in a periodic potential and a magnetic field is studied in the weak barrier limit and in the tight binding regime. For the case of half flux per plaquette, and for a wide range of values of the dissipation, the physics of the model is determined by a nontrivial fixed point. A combination of exact and variational results is used to characterize this fixed point. Finally, it is also argued that there is an intermediate energy scale that separates the weak coupling physics from the tight binding solution.

Novais, E. [Department of Physics, Boston University, Boston, Massachusetts 02215 (United States); Department of Physics, Duke University, Durham, North Carolina 27708 (United States); Guinea, F. [Department of Physics, Boston University, Boston, Massachusetts 02215 (United States); Instituto de Ciencia de Materiales de Madrid, CSIC, E-28049 Madrid (Spain); Castro Neto, A.H. [Department of Physics, Boston University, Boston, Massachusetts 02215 (United States)

2005-05-06

9

Infrared fixed point in quantum Einstein gravity  

NASA Astrophysics Data System (ADS)

We performed the renormalization group analysis of the quantum Einstein gravity in the deep infrared regime for different types of extensions of the model. It is shown that an attractive infrared point exists in the broken symmetric phase of the model. It is also shown that due to the Gaussian fixed point the IR critical exponent ? of the correlation length is 1/2. However, there exists a certain extension of the model which gives finite correlation length in the broken symmetric phase. It typically appears in case of models possessing a first order phase transitions as is demonstrated on the example of the scalar field theory with a Coleman-Weinberg potential.

Nagy, S.; Krizsan, J.; Sailer, K.

2012-07-01

10

47 CFR 101.137 - Interconnection of private operational fixed point-to-point microwave stations.  

Code of Federal Regulations, 2010 CFR

...private operational fixed point-to-point microwave stations. 101.137 Section 101...SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Technical Standards § 101...private operational fixed point-to-point microwave stations. Private operational...

2010-10-01

11

47 CFR 101.137 - Interconnection of private operational fixed point-to-point microwave stations.  

Code of Federal Regulations, 2010 CFR

...private operational fixed point-to-point microwave stations. 101.137 Section 101...SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Technical Standards § 101...private operational fixed point-to-point microwave stations. Private operational...

2009-10-01

12

47 CFR 101.137 - Interconnection of private operational fixed point-to-point microwave stations.  

Code of Federal Regulations, 2011 CFR

...private operational fixed point-to-point microwave stations. 101.137 Section 101...SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Technical Standards § 101...private operational fixed point-to-point microwave stations. Private operational...

2011-10-01

13

47 CFR 101.137 - Interconnection of private operational fixed point-to-point microwave stations.  

Code of Federal Regulations, 2012 CFR

...private operational fixed point-to-point microwave stations. 101.137 Section 101...SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Technical Standards § 101...private operational fixed point-to-point microwave stations. Private operational...

2012-10-01

14

New SMU Gallium Fixed-Point Cells  

NASA Astrophysics Data System (ADS)

In the framework of the European research project EURAMET 732, the Slovak Institute of Metrology (SMU) built three primary gallium fixed-point cells of different designs. The cells are designed for the calibration of the long-stem SPRT. In regard to the procedure commonly used at SMU when realizing the gallium point, the cells are designed for use in a stirred liquid bath. This article provides information about the cell designs, materials used, method of filling, and results of the performed experiments. The experiments were focused on the study of the cells' metrological characteristics, some effects that could influence the melting-point temperature and the effect of the melted metal fraction on the immersion profile. New cells were compared with the SMU reference gallium cell.

Ranostaj, Juraj; ?uriš, Stanislav; Knorová, Renáta; Kaskötö, Mariana; Vysko?ilová, Irena

2011-08-01

15

Effects of nondenumerable fixed points in finite dynamical systems  

NASA Astrophysics Data System (ADS)

The motion of a spinning soccer ball brings forth the possible existence of a whole class of finite dynamical systems where there may be a nondenumerably infinite number of fixed points. They defy the very traditional meaning of the fixed point that a point on the fixed point in the phase space should remain there forever, for, a fixed point can evolve as well! Under such considerations one can argue that a free-kicked soccer ball should be nonchaotic.

Chakraborty, Sagar; Bhattacharjee, J. K.

2008-03-01

16

Holographic non-Fermi-liquid fixed points.  

PubMed

Techniques arising from string theory can be used to study assemblies of strongly interacting fermions. Via this 'holographic duality', various strongly coupled many-body systems are solved using an auxiliary theory of gravity. Simple holographic realizations of finite density exhibit single-particle spectral functions with sharp Fermi surfaces, of a form distinct from those of the Landau theory. The self-energy is given by a correlation function in an infrared (IR) fixed-point theory that is represented by a two-dimensional anti de Sitter space (AdS(2)) region in the dual gravitational description. Here, we describe in detail the gravity calculation of this IR correlation function. PMID:21422019

Faulkner, Tom; Iqbal, Nabil; Liu, Hong; McGreevy, John; Vegh, David

2011-04-28

17

Partial Fixed-Point Logic on Infinite Structures  

Microsoft Academic Search

Abstract: We consider an alternative semantics for partial fixed-point logic (PFP). To define the fixed point of a formula in this semantics, the sequence of stages induced by the formula is considered. As soon as this sequence becomes cyclic, the set of elements contained in every stage of the cycle is taken as the fixed point. It is shown that

Stephan Kreutzer; RWTH Aachen

2002-01-01

18

The Fermi liquid as a renormalization group fixed point  

NASA Astrophysics Data System (ADS)

The renormalization-group (RG) method is applied to study interacting fermions at finite temperature. A model based on the psi4-Grassmann effective action with SU(N)-invariant short-range interaction and a rotationally invariant Fermi surface in spatial dimensions d = 2, 3 is studied. We show how the key results of the Landau Fermi liquid theory can be recovered by this finite-temperature RG technique. Applying the RG to response functions, we find the compressibility and the spin susceptibility as solutions of the RG flow equations. We discuss subtleties associated with the symmetry properties of the four-point vertex (the implications of the Pauli principle). We point out distinctions between three quantities: the bare interaction of the low-energy effective action, the Landau function and the forward scattering vertex. The bare interaction of the effective action is not a RG fixed point, but a common starting point of the flow trajectories of two limiting forms of the four-point vertex. We have derived RG equations for the Landau channel that take into account both contributions of the direct (ZS) and the exchange (ZS') particle-hole graphs at one-loop level. The basic quantities of Fermi Liquid theory, the Landau interaction function and the forward scattering vertex, are calculated as fixed points of these flows in terms of the effective action's interaction function. The classic derivations of Fermi Liquid theory applying the Bethe-Salpeter equation and other analogous approaches, tantamount to some sort of RPA-type (decoupled) approximation, neglect the zero-angle singularity in the ZS' graph. As a consequence, the antisymmetry of the forward scattering vertex is not guaranteed in the final result, and the RPA sum rule must be imposed by hand on the components of the Landau function to satisfy the Pauli principle. This sum rule, not indispensable in the original phenomenological formulation of the Landau FLT, is equivalent, from the RG point of view, to a fine tuning of the effective interaction. Our results show that the strong interference of the direct and exchange processes of the particle-hole scattering near zero angle invalidates the RPA (decoupled) approximation in this region, resulting in temperature-dependent narrow-angle anomalies in the Landau function and scattering vertex, revealed by the RG analysis. In the present RG approach the Pauli principle is automatically satisfied. As follows from the RG solution, the amplitude sum rule, being an artefact of the RPA approximation, is not needed to respect statistics and, moreover, is not valid.

Chitov, Guennadi

19

Some fixed point results for multi-valued cyclic mappings  

NASA Astrophysics Data System (ADS)

This paper investigates the fixed points and best proximity points of multivalued cyclic self-mappings in metric spaces under a generalized contractive condition involving Hausdorff distances. Some previous results for cyclic self-mappings or for multivalued self-mappings in metric fixed point theory are extended to cyclic multivalued self-mappings.

De la Sen, M.; Singh, S. L.; Gordji, M. E.

2013-09-01

20

SEQUENCES OF CONTRACTIONS AND CONVERGENCE OF FIXED POINTS  

Microsoft Academic Search

Stability of fixed points of contraction mappings has been studied by Bonsall (cf. (2)) and Nadler (cf. (4)). These authors consider a sequence (Tn) of maps defined on a metric space (X, d) into itself and study the convergence of the sequence of fixed points for uniform or pointwise convergence of (Tn), under contraction assumptions of the maps. We will

Luc Barbet; Khadra Nachi

21

Realization of the Indium Fixed Point by an Adiabatic Technique  

NASA Astrophysics Data System (ADS)

This work investigates the effect of heating techniques on the realization of the ITS-90 fixed points above room temperature. For that purpose, LNE has constructed a new apparatus to realize the indium fixed point under adiabatic conditions using the “calorimetric” method. The adiabatic condition, in general, is established by maintaining a temperature difference between the fixed-point cell and its surroundings that is as small as possible. In this work, the indium fixed-point cell is located within thermally controlled heat shields whose walls also contain indium. Thus, the shields themselves are also indium cells. The experiments realizing the melting and freezing temperatures of indium using the calorimetric method are described. The results revealed the existence of thermal effects in the realization of the indium fixed-point cell by the conventional “continuous heat flux” method. The advantages of the “cell-within-cell” technique are presented.

Morice, R.; Bonnier, G.; Barbaras, J. C.; Fleurence, N.; Le Sant, V.; Ridoux, P.; Filtz, J. R.

2008-10-01

22

Palladium-Carbon Eutectic Fixed Point for Thermocouple Calibration  

NASA Astrophysics Data System (ADS)

A Pd-C eutectic fixed point has been produced using a molybdenum disilicide element, electrically heated furnace that was built in-house. The eutectic fixed point was measured with two Pt/Pd thermocouples calibrated at the fixed points of Sn, Zn, Al, Ag, and Au. An ITS-90 temperature of (1490.69 ± 0.88) °C ( k = 2) was obtained for the inflection point of the melting plateau. Diffusion of Pd into the thermowell and onto the thermocouple protection tube was observed.

Todd, A. D. W.; Gotoh, M.; Woods, D. J.; Hill, K. D.

2011-01-01

23

A new compact fixed-point blackbody furnace  

NASA Astrophysics Data System (ADS)

More and more NMIs are realizing their primary scale themselves with fixed-point blackbodies as their reference standard. However, commercially available fixed-point blackbody furnaces of sufficient quality are not always easy to obtain. CHINO Corp. and NMIJ, AIST jointly developed a new compact fixed-point blackbody furnace. The new furnace has such features as 1) improved temperature uniformity when compared to previous products, enabling better plateau quality, 2) adoption of the hybrid fixed-point cell structure with internal insulation to improve robustness and thereby to extend lifetime, 3) easily ejectable and replaceable heater unit and fixed-point cell design, leading to reduced maintenance cost, 4) interchangeability among multiple fixed points from In to Cu points. The replaceable cell feature facilitates long term maintenance of the scale through management of a group of fixed-point cells of the same type. The compact furnace is easily transportable and therefore can also function as a traveling standard for disseminating the radiation temperature scale, and for maintaining the scale at the secondary level and industrial calibration laboratories. It is expected that the furnace will play a key role of the traveling standard in the anticipated APMP supplementary comparison of the radiation thermometry scale.

Hiraka, K.; Yamada, Y.; Ishii, J.; Oikawa, H.; Shimizu, T.; Kadoya, S.; Kobayashi, T.

2013-09-01

24

Establishment of NIMT Zinc Fixed-Point Cell  

NASA Astrophysics Data System (ADS)

One of the research programs for the Thermometry Metrology Department at the National Institute of Metrology (Thailand), NIMT, is establishment of its own fixed-point cells. Among the fixed-point cells adopted for the realization of the International Temperature Scale of 1990 (ITS-90), NIMT has chosen the zinc fixed point to start the program. The fabrication and the initial evaluation of the zinc fixed-point cell were conducted at the National Metrology Institute of Japan, NMIJ. The cell fabrication was following the design and procedures developed by the NMIJ. In the cell fabrication, a 6N nominal purity zinc metal cylinder ingot was used. The metal ingot was collected in a graphite crucible under an argon gas atmosphere. The new fixed-point cell was compared with the old fixed-point cells already owned by NIMT, namely, one open-type cell and one sealed-type cell by direct cell comparisons. Since the ingot was equipped with a detail impurity element analysis, it is possible to calculate the effect coming from the existence of the impurities based on, for example, the sum of individual estimates (SIE) method. This effect can then be used to correct for the influence impurities on the realization of the temperature fixed point.

Yaokulbodee, C.; Norranim, U.; Widiatmo, J. V.; Yamazawa, K.; Tamba, J.

2010-09-01

25

Fixed-Point Comparison Uncertainties for Two Cell Geometries  

NASA Astrophysics Data System (ADS)

To realize the ITS-90 according to its definition, among others, the melting and freezing temperatures of ideally pure metals are needed. Therefore, many national metrology institutes (NMIs) utilize a group of cells instead of one single cell as the national reference for each temperature. With direct fixed-point cell comparisons on a regular basis, it is feasible to account for the small differences between the individual fixed-point temperatures and to detect possible temperature drifts of the cells. At PTB (the German NMI), in recent years, these groups of national standard cells and the so-called transfer cells for calibrations have been complemented by newly developed slim fixed points. These cells typically contain 75% to 80% less fixed-point material compared with standard cells. Slim cells are used for homogeneity investigations of large batches of fixed-point material, for doping experiments to determine the influence of very small amounts of impurities on the fixed-point temperature with very small uncertainties, and for the investigation of contamination or purification effects after the manufacture of a fixed-point cell. These investigations have shown that the main limitation of slim cells is the quality of the phase boundary. The small dimensions of the cell do not allow the formation of a closed phase boundary (or even two of them). However, this can be compensated using a quasi-adiabatic realization procedure, and in this way, uncertainties comparable to those of standard fixed-point cells can be achieved. In this article, the design of the cells as well as typical measurement results and uncertainties for the direct comparison of fixed-point cells of both types, the standard size and slim design, are presented.

Fahr, M.; Rudtsch, S.; Gerlitzke, A.-K.

2011-12-01

26

Coincidence and fixed points in symmetric spaces under strict contractions  

NASA Astrophysics Data System (ADS)

Some common fixed point theorems due to Aamri and El Moutawakil [M. Aamri, D. El Moutawakil, Some new common fixed point theorems under strict contractive conditions, J. Math. Anal. Appl. 270 (2002) 181-188] and Pant and Pant [R.P. Pant, V. Pant, Common fixed points under strict contractive conditions, J. Math. Anal. Appl. 248 (2000) 327-332] proved for strict contractive mappings in metric spaces are extended to symmetric (semi-metric) spaces under tight conditions. Some related results are derived besides discussing illustrative examples which establish the utility of results proved in this note.

Imdad, M.; Ali, Javid; Khan, Ladlay

2006-08-01

27

Fixed point theory for generalized contractions in cone metric spaces  

NASA Astrophysics Data System (ADS)

In this paper, we prove some fixed point theorems for generalized contractions in cone metric spaces. Our theorems extend some results of Suzuki (2008) [T. Suzuki, A generalized Banach contraction principle that characterizes metric completeness, Proc Amer Math Soc 136(5) (2008), 1861-1869] and Kikkawa and Suzuki (2008) [M. Kikkawa and T. Suzuki, Three fixed point theorems for generalized contractions with constants in complete metric spaces, Nonlinear Anal 69(9) (2008), 2942-2949].

Farajzadeh, A. P.; Amini-Harandi, A.; Baleanu, D.

2012-02-01

28

Further Findings of Impurity Precipitation in Metal Fixed Points  

NASA Astrophysics Data System (ADS)

Impurities are believed to be one of the major issues in realizing the metal fixed-point temperatures of the ITS-90 with a low degree of uncertainty. This has raised interest in the individual effects of impurities on the phase-transition temperature of fixed-point metals. Surprisingly, impurities that do not affect a fixed-point temperature have been found experimentally. A possible explanation for this behavior is the formation of insoluble oxides of the added impurities consuming oxygen already present in the fixed-point cell (mostly as an oxide of the fixed-point metal). This is supported by several recent publications. However, all the results could be coincidental. This article presents more convincing proof for the formation of insoluble compounds born from impurities dissolved in the fixed-point metal. Based on refined doping experiments and using impurities that have not been investigated before, both the impurities' dissolution and the precipitation could be observed as an initial decrease (or increase) of the fixed-point temperature followed by a gradual return to its original value. The selected impurities (gallium and zinc in indium) were found to dissolve within a few days and precipitate out within no more than two weeks. The behavior of iron in indium was investigated as well, but the results are not conclusive. Finally, another series of doping experiments indicates that sulfur does not dissolve in indium in significant amounts, but forms insoluble compounds (probably sulfides) when added to the metal. This supports the general assumption that metal-non-metal compounds might be present in the cell without being noticed.

Fahr, M.; Rudtsch, S.; Aulich, A.

2011-12-01

29

Stray thermal influences in zinc fixed-point cells  

NASA Astrophysics Data System (ADS)

The influence of thermal effects is a major uncertainty contribution to the calibration of Standard Platinum Resistance Thermometers (SPRTs) in fixed-point cells. Axial heat losses strongly depend on the fixed-point temperature, constructional details of cells and SPRTs and the resulting heat transfer between cell, thermometer, furnace and environment. At the zinc point contributions by heat conduction and thermal radiation must be considered. Although the measurement of temperature gradients in the re-entrant well of a fixed-point cell provides very important information about the influence of axial heat losses, further investigations are required for a reliable estimate of the resulting uncertainty contribution. It is shown that specific modifications of a zinc fixed-point cell, following generally accepted principles, may result in systematic deviations of the measured fixed-point temperatures larger than typically stated in the uncertainty budget of National Metrology Institutes (NMIs). The underlying heat transport processes are investigated and the consequences for the construction of zinc cells are discussed.

Rudtsch, S.; Aulich, A.; Monte, C.

2013-09-01

30

Field identification fixed points in the coset construction  

NASA Astrophysics Data System (ADS)

We discuss two related problems in conformal field theory. The first is the construction of the modular transformation matrix S for integer spin modular invariants in which some characters appear with multiplicity larger than 1. The second problem is the relation between the characters and the branching functions in coset theories in which the field identification identifies some fields with themselves (``fixed points''). We find that these problems are closely related, and that the solution is remarkably interesting. The fixed points of any conformal field theory seem always to define a new (not necessarily unitary) conformal field theory whose primary fields are in one-to-one correspondence with the fixed points. The characters of this conformal field theory are needed to modify the coset branching functions. Permanent address: School of Physics and Astronomy, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel-Aviv University, Israel.

Schellekens, A. N.; Yankielowicz, S.

1990-04-01

31

Cobalt-Carbon Eutectic Fixed Point for Contact Thermometry  

NASA Astrophysics Data System (ADS)

Two Co-C eutectic fixed points were constructed for thermocouple calibration. The eutectic fixed points were measured with a Pt/Pd thermocouple calibrated at the freezing temperatures of Sn, Zn, Al, Ag, and Au. A temperature of (1323.99 ± 0.52) °C ( k = 2) was determined via this method. The cell design allowed filling to be accomplished in a single step. Each cell was held above 1300 °C for at least 42 h and was subjected to at least 20 melt/freeze cycles with no mechanical failure occurring.

Todd, A. D. W.; Gotoh, M.; Woods, D. J.; Hill, K. D.

2011-01-01

32

On R-symmetric Fixed Points and Superconformality  

SciTech Connect

An important unanswered question in quantum field theory is to understand precisely under which conditions scale invariance implies invariance under the full conformal group. While the general answer in two dimensions has been known for over 20 years, a precise nonperturbative relation between scale and conformal invariance in higher dimensions has been lacking. In this note, we specialize to four dimensions and give a full quantum mechanical proof that certain unitary R-symmetric fixed points are necessarily superconformal. Among other consequences, this result implies that the infrared fixed points of N=1 supersymmetric quantum chromodynamics are superconformal.

Antoniadis, Ignatios; Buican, Matthew [Department of Physics, CERN Theory Division, CH-1211 Geneva 23 (Switzerland)

2011-05-15

33

Measurement of thermodynamic temperature of high temperature fixed points  

NASA Astrophysics Data System (ADS)

The paper is devoted to VNIIOFI's measurements of thermodynamic temperature of the high temperature fixed points Co-C, Pt-C and Re-C within the scope of the international project coordinated by the Consultative Committee for Thermometry working group 5 "Radiation Thermometry". The melting temperatures of the fixed points were measured by a radiance mode radiation thermometer calibrated against a filter radiometer with known irradiance spectral responsivity via a high temperature black body. This paper describes the facility used for the measurements, the results and estimated uncertainties.

Gavrilov, V. R.; Khlevnoy, B. B.; Otryaskin, D. A.; Grigorieva, I. A.; Samoylov, M. L.; Sapritsky, V. I.

2013-09-01

34

Dynamics of an absolutely rigid body with a fixed point  

Microsoft Academic Search

One hundred forty nine selected papers (published in the twentieth century) which deal with the dynamics of solids having a fixed point are analyzed. The various forms of the respective dynamic and kinematic equations of motion are studied, and their solutions are classified. The principal developmental trends in this field of mechanics are identified and their current status is described.

B. N. Fradlin; V. M. Sliusarenko

1975-01-01

35

Greguš type fixed points for weakly compatible maps  

Microsoft Academic Search

In this paper we prove a common fixed point theorem of Greguš contraction type by using minimal type commutativity without continuity\\u000arequirements. The theorem extends known results on compatible continuous\\u000amaps of [1]-[3], [7], [8] and [9], to a larger class of mappings.

A. Djoudi; L. Nisse

2003-01-01

36

Development of Fixed-Point Cells at the SMU  

NASA Astrophysics Data System (ADS)

One of the research programs realized at the thermometry laboratory of the Slovak Institute of Metrology (SMU) in recent years has focused on the development of fixed-point cells. In the frame of this research, several primary cells for realization of the International Temperature Scale of 1990 (ITS-90) and several secondary cells for industrial thermometer calibrations were built and studied. This article discusses primary cells for the gallium and mercury fixed points and miniature cells for the zinc point that were developed at the SMU. Information about the cell designs is provided, the materials that were used are specified, and the procedures for their manufacture are described. Briefly, the realization of the fixed points of mercury, gallium, and zinc by using these cells is also described. Many experiments were carried out to study the characteristics of these cells. One of the gallium cells was compared with the circulating transfer cell during the key comparison CCT-K3, and it and the mercury cell were used for the EUROMET Project No. 552. The results of the experiments together with the results of the comparisons show the high quality of these cells. Secondary zinc-point cells were compared against SMU primary zinc-point cells. The comparison shows agreement within 0.12 mK.

?uriš, S.; Ranostaj, J.; Palen?ár, R.

2008-06-01

37

New protocol for the realization of the triple points of cryogenic gases as temperature fixed points  

NASA Astrophysics Data System (ADS)

An improved protocol or measurement program is presented for the realization of the triple points of cryogenic gases as temperature fixed points. The protocol contains general recommendations in different directions: determination of the thermal parameters of the fixed-point cells containing the samples and of the apparatus, measurement conditions, series of measurements, reporting of data, establishment of an uncertainty budget, especially the reliable estimation of static and dynamic temperature-measurement errors. Such a detailed protocol is necessary for reaching the highest metrological level due to the special properties of the cryogenic gases as fixed-point substances. Considering the newest developments, the state-of-the-art level of the realization of the low-temperature fixed points is described.

Fellmuth, B.

2013-09-01

38

Gravity Duals of Lifshitz-Like Fixed Points  

SciTech Connect

We find candidate macroscopic gravity duals for scale-invariant but non-Lorentz invariant fixed points, which do not have particle number as a conserved quantity. We compute two-point correlation functions which exhibit novel behavior relative to their AdS counterparts, and find holographic renormalization group flows to conformal field theories. Our theories are characterized by a dynamical critical exponent z, which governs the anisotropy between spatial and temporal scaling t {yields} {lambda}{sup z}t, x {yields} {lambda}x; we focus on the case with z = 2. Such theories describe multicritical points in certain magnetic materials and liquid crystals, and have been shown to arise at quantum critical points in toy models of the cuprate superconductors. This work can be considered a small step towards making useful dual descriptions of such critical points.

Kachru, Shamit; /Stanford U., Phys. Dept. /SLAC; Liu, Xiao; /Perimeter Inst. Theor. Phys.; Mulligan, Michael; /Stanford U., Phys. Dept. /SLAC

2008-11-05

39

Some Curious Results with a Gallium Fixed-Point Cell  

NASA Astrophysics Data System (ADS)

In 2009, most of the gallium fixed-point cells in use in different INRIM laboratories were compared with Italy's national standard. The comparison has uncovered problems with one of the commercial devices, realizing a temperature about 0.7 mK too low which initially was even changing linearly with time. An additional series of measurements was undertaken to find out the reason for this behavior, but not being allowed to open the cell, only a suspicion on the possible cause has remained. A way is suggested that might give users an indication of such misbehavior of their cell. The results underline the importance for those NMIs with only a single cell, for any fixed point, to undertake regular comparisons with another cell as a check on its behavior.

Steur, P. P. M.; Dematteis, R.

2011-01-01

40

Asymptotics of fixed point distributions for inexact Monte Carlo algorithms  

SciTech Connect

We introduce a simple general method for finding the equilibrium distribution for a class of widely used inexact Markov chain Monte Carlo algorithms. The explicit error due to the noncommutativity of the updating operators when numerically integrating Hamilton's equations can be derived using the Baker-Campbell-Hausdorff formula. This error is manifest in the conservation of a shadow Hamiltonian that lies close to the desired Hamiltonian. The fixed point distribution of inexact hybrid algorithms may then be derived taking into account that the fixed point of the momentum heat bath and that of the molecular dynamics do not coincide exactly. We perform this derivation for various inexact algorithms used for lattice QCD calculations.

Clark, M. A.; Kennedy, A. D. [Center for Computational Sciences, Boston University, 3 Cummington Street, Boston, Massachusetts 02215 (United States); School of Physics, University of Edinburgh, Mayfield Road, Edinburgh, EH9 3JZ (United Kingdom)

2007-10-01

41

Overscreened Kondo fixed point in S=1 spin liquid  

NASA Astrophysics Data System (ADS)

We propose a possible realization of the overscreened Kondo impurity problem by a magnetic s=1/2 impurity embedded in a two-dimensional S=1 U(1) spin liquid with a Fermi surface. This problem contains an interesting interplay between non-Fermi-liquid behavior induced by a U(1) gauge field coupled to fermions and a non-Fermi-liquid fixed point in the overscreened Kondo problem. Using a large-N expansion together with an expansion in the dynamical exponent of the gauge field, we find that the coupling to the gauge field leads to weak but observable changes in the physical properties of the system at the overscreened Kondo fixed point. We discuss the extrapolation of this result to a physical case and argue that the realization of overscreened Kondo physics could lead to observations of effects due to gauge fields.

Serbyn, Maksym; Senthil, T.; Lee, Patrick A.

2013-07-01

42

Thermal analysis on the realization of the tin fixed point  

NASA Astrophysics Data System (ADS)

A study on the thermal analysis of a new tin fixed-point open cell within a new three-zone furnace was carried out. The stability at the setting temperatures of liquid-solid coexisting together with some degree Celsius lower and higher than the tin fixed point; and the axial uniformity of furnace while tin is still in solid phase were investigated and analyzed. The impurities effect on the depression in temperature was investigated in terms of ?T (Tobserved-T1/F=0) and the inverse of the melted fraction (1/F) relationship during the melting and the following freezing realizations at various temperature settings of furnace. These thermal analysis results were also compared with those estimated by the CCT-WG1 recommended SIE (sum of individual estimates) method, which leads to a temperature correction along with a corresponding uncertainty through the individual impurity content detected by GDMS (glow discharge mass spectrometry).

Tsai, S. F.

2013-09-01

43

The computational core and fixed point organization in Boolean networks  

NASA Astrophysics Data System (ADS)

In this paper, we analyse large random Boolean networks in terms of a constraint satisfaction problem. We first develop an algorithmic scheme which allows us to prune simple logical cascades and underdetermined variables, returning thereby the computational core of the network. Second, we apply the cavity method to analyse the number and organization of fixed points. We find in particular a phase transition between an easy and a complex regulatory phase, the latter being characterized by the existence of an exponential number of macroscopically separated fixed point clusters. The different techniques developed are reinterpreted as algorithms for the analysis of single Boolean networks, and they are applied in the analysis of and in silico experiments on the gene regulatory networks of baker's yeast (Saccharomyces cerevisiae) and the segment-polarity genes of the fruitfly Drosophila melanogaster.

Correale, L.; Leone, M.; Pagnani, A.; Weigt, M.; Zecchina, R.

2006-03-01

44

On the Fixed-Point Accuracy Analysis of FFT Algorithms  

Microsoft Academic Search

In this paper, we investigate the effect of fixed-point arithmetics with limited precision for different fast Fourier transform (FFT) algorithms. A matrix representation of error propagation model is proposed to analyze the rounding effect. An analytic expression of overall quantization loss due to the arithmetic quantization errors is derived to compare the performance with decimation-in-time (DIT) and decimation-in-frequency (DIF) configurations.

Wei-Hsin Chang; Truong Q. Nguyen

2008-01-01

45

The Dynamics of Multidimensional Secession: Fixed Points and Ideological Condensation  

NASA Astrophysics Data System (ADS)

We explore a generalized, stochastic seceder model of societal dynamics with variable size polling groups and higher-dimensional opinion vectors, revealing its essential modes of self-organized segregation. Renormalizing to a discrete, deterministic version, we pin down the upper critical size of the sampling group and analytically uncover a self-similar hierarchy of dynamically stable, multiple-branch fixed points. In d?3, the evolving, coarsening population suffers collapse to a 2D ideological plane.

Soulier, Arne; Halpin-Healy, Tim

2003-06-01

46

Fixed point structure of quenched, planar quantum electrodynamics  

SciTech Connect

Gauge theories exhibiting a hierarchy of fermion mass scales may contain a pseudo-Nambu-Boldstone boson of spontaneously broken scale invariance. The relation between scale and chiral symmetry breaking is studied analytically in quenched, planar quantum electrodynamics in four dimensions. The model possesses a novel nonperturbative ultraviolet fixed point governing its strong coupling phase which requires the mixing of four fermion operators. 12 refs.

Love, S.T.

1986-07-01

47

Expressive Equivalence of Least and Inflationary Fixed-Point Logic  

Microsoft Academic Search

We study the relationship between least and inflationary fixed-point logic. By results of Gurevich and Shelah from 1986, it has been known that on finite structures both log- ics have the same expressive power. On infinite structures however, the question whether there is a formula inIFP not equivalent to anyLFP-formula was still open. In this paper, we settle the question

Stephan Kreutzer; RWTH Aachen

2002-01-01

48

Pseudocontractions in the intermediate sense: Fixed and best proximity points  

NASA Astrophysics Data System (ADS)

This paper studies a general contractive condition for a class of two-cyclic self-maps on the union of a finite number of subsets of a metric space which are allowed to have a finite number of successive images in the same subsets of its domain. If the space is uniformly convex and the subsets are non-empty, closed and convex then all the iterated sequences are proved to converge to a unique closed limiting finite sequence. Such a sequence contains the best proximity points of adjacent subsets which coincide with a unique fixed point if all such subsets intersect.

De la Sen, Manuel

2013-09-01

49

A common fixed point theorem for a commuting family of nonexpansive mappings  

Microsoft Academic Search

It is shown that if a closed convex subset C of a Banach space has both the fixed point property and the conditional fixed point prop- erty for nonexpansive mappings and C is either weakly compact or bounded and separable, then any commuting family of nonexpansive self-mappings of C has a common fixed point. The set of common fixed points

Ronald E. Bruck

1974-01-01

50

A new orientifold of C2\\/ZN and six-dimensional RG fixed points  

Microsoft Academic Search

We discuss the consistency conditions of a novel orientifold projection of type IIB string theory on C2\\/ZN singularities, in which one mods out by the combined action of world-sheet parity and a geometric operation which exchanges the two complex planes. The field theory on the world-volume of D5-brane probes defines a family of six-dimensional RG fixed points, which had been

A. M. Uranga

2000-01-01

51

A new orientifold of C 2\\/Z N and six-dimensional RG fixed points  

Microsoft Academic Search

We discuss the consistency conditions of a novel orientifold projection of type IIB string theory on C2\\/ZN singularities, in which one mods out by the combined action of world-sheet parity and a geometric operation which exchanges the two complex planes. The field theory on the world-volume of D5-brane probes defines a family of six-dimensional RG fixed points, which had been

Angel M. Uranga

2000-01-01

52

Impurity and thermal modelling of SPRT fixed-points  

NASA Astrophysics Data System (ADS)

Impurities in pure metal fixed points for the calibration of standard platinum resistance thermometers (SPRTs) causes significant variations in the freezing temperature, of the order of sub-mK to several mK. This often represents the largest contribution to the overall uncertainty of the fixed point temperature, and it is therefore of great interest to explore ways of correcting for this effect. The sum of individual estimates (SIE) method, in which the contributions of all the impurities are summed, is the recommended way of determining the correction if one has an accurate knowledge of the impurities present and their low concentration liquidus slopes. However, due to the difficulty in obtaining reliable iningot impurity corrections, it remains useful to investigate the influence of impurities on freezing curves using modeling techniques, and ultimately to parameterize the freezing curve by e.g. least-squares fitting to make corrections to the temperature of the freeze. Some success in analyzing freezing curves has been achieved. When parameterizing experimentally determined freezing curves, it is necessary to reliably determine the freezing end-point, and minimize spurious thermal effects. We outline some methods for meeting these requirements. As the influence of impurities is always convolved with thermal influences it is instructive to construct a model which takes into account both heat and impurity transport. We describe the development of more sophisticated models which take both these effects into account.

Pearce, J. V.; Veltcheva, R. I.; Large, M. J.

2013-09-01

53

Sequential fixed-point ICA based on mutual information minimization.  

PubMed

A new gradient technique is introduced for linear independent component analysis (ICA) based on the Edgeworth expansion of mutual information, for which the algorithm operates sequentially using fixed-point iterations. In order to address the adverse effect of outliers, a robust version of the Edgeworth expansion is adopted, in terms of robust cumulants, and robust derivatives of the Hermite polynomials are used. Also, a new constrained version of ICA is introduced, based on goal programming of mutual information objectives, which is applied to the extraction of the antepartum fetal electrocardiogram from multielectrode cutaneous recordings on the mother's thorax and abdomen. PMID:18085987

Van Hulle, Marc M

2008-05-01

54

Maximal Points of Head's Zone in Fixed Drug Eruption  

PubMed Central

The principles determining the primary localization of lesions in fixed drug eruption (FDE) are still unknown. Studies investigating the predilection areas in FDE have indicated drug-related, trauma-related, or inflammation-related specific site involvement, as well as visceracutaneous reflex-related specific site involvement. The importance of viscerocutaneous reflexes for the location of dermatoses was first recognized in the 1960s. Head's zones are viscerocutaneous reflex projection fields on the skin that extend over certain dermatomes and possess a reflex-associated maximal point. Recently, in a Turkish collective of patients, three women with the primary location of FDE lesions on the maximal points of Head's zones were presented. We also experienced 3 cases with FDE where the lesions were located at specific sites (buttocks), the so-called maximal points of Head's zones, which are known to be the most active dermatomal areas of an underlying visceral pathology. An underlying internal disturbance (ureter stone, pyelonephritis and chronic pelvic inflammatory disease) was found in all 3 patients, corresponding to the organ-related maximal point of Head's zones in each case. In conclusion, the primary location of FDE lesions on the maximal points of Head's zones revealed relevant organ disorders with corresponding projection fields.

Lee, Sang Sin; Hong, Dong Kyun; Im, Myung; Lee, Young; Seo, Young Joon

2011-01-01

55

Twelve years of high temperature fixed point research: A review  

NASA Astrophysics Data System (ADS)

A review of research into high temperature fixed points (HTFPs), since their inception at NMIJ in 1999 until 2011 is given. HTFPs discussed in this paper are those whose transition temperatures are above the freezing point of copper and based on eutectic/peritectic alloys. The paper will begin with an historical overview; including a description of the different types of modern HTFPs. The evolution of construction methods of HTFPs will be elaborated. The performance of the current generation of HTFPs will be compared to that of earlier ones. Current uses of HTFPs will be described. Finally an overview of some remaining research issues will be given including assignment of definitive thermodynamic temperatures and inclusion into the developing mise en pratique for the definition of the kelvin.

Machin, G.

2013-09-01

56

Fate of CPN-1 Fixed Points with q Monopoles  

NASA Astrophysics Data System (ADS)

We present an extensive quantum Monte Carlo study of the Néel to valence-bond solid (VBS) phase transition on rectangular- and honeycomb-lattice SU(N) antiferromagnets in sign-problem-free models. We find that in contrast to the honeycomb lattice and previously studied square-lattice systems, on the rectangular lattice for small N, a first-order Néel-VBS transition is realized. On increasing N?4, we observe that the transition becomes continuous and with the same universal exponents as found on the honeycomb and square lattices (studied here for N=5, 7, 10), providing strong support for a deconfined quantum critical point. Combining our new results with previous numerical and analytical studies, we present a general phase diagram of the stability of CPN-1 fixed points with q monopoles.

Block, Matthew S.; Melko, Roger G.; Kaul, Ribhu K.

2013-09-01

57

Surveying the three-dimensional fixed points of T duality  

NASA Astrophysics Data System (ADS)

We explore the family of fixed points of T-duality transformations in three dimensions. For the simplest nontrivial self-duality conditions it is possible to show that, in addition to the spacelike isometry in which the T-duality transformation is performed, these backgrounds must be necessarily stationary. This allows us to prove that, for nontrivial string coupling, the low energy bosonic string backgrounds, which are additionally self-T-dual along an isometry direction generated by a constant norm Killing vector, are uniquely described by a two-parametric class, including only three nonsingular cases: the charged black string, the exact gravitational wave propagating along the extremal black string, and the flat space with a linear dilaton. Besides, for constant string coupling, the only self-T-dual lower energy string background under the same assumptions corresponds to the Coussaert-Henneaux spacetime. Thus, we identify minimum criteria that yield a classification of these quoted examples and only these. All these T-dual fixed points describe exact backgrounds of string theory.

Ayón-Beato, Eloy; Giribet, Gastón

2007-02-01

58

Infrared fixed points and fixed lines in the top-bottom-tau sector in supersymmetric grand unification  

NASA Astrophysics Data System (ADS)

The two-loop ``top-down'' renormalization group flow for the top, bottom and tau Yukawa couplings, from ? = MGUT ~=O (1016 GeV) to ? ~= mt, is explored in the framework of supersymmetric grand unification; reproduction of the physical bottom and tau masses is required. Instead of following the recent trend of implementing exact Yukawa coupling unification i) a search for infrared (IR) fixed lines and fixed points in the mpolet-tan ? plane is performed and ii) the extent to which these imply approximate Yukawa unification is determined. In the mpolet-tan ? plane two IR fixed lines, intersecting in an IR fixed point, are located. The more attractive fixed line has a branch of almost constant top mass, mpolet ~= 168-180 GeV (close to the experimental value), for the large interval 2.5 <~ tan ? <~ 55; it realizes tau-bottom Yukawa unification atMGUT approximately. The less attractive fixed line as well as the fixed point at mpolet ~= 170 GeV, tan ? ~= 55 implement approximate top-bottom Yukawa unification at all scales ?. The renormalization group flow is attracted towards the IR fixed point by way of the more attractive IR fixed line. The fixed point and lines are distinct from the much quoted effective IR fixed pointmpolet ~= O(200 GeV) sin ?.

Schrempp, Barbara

1995-02-01

59

Epidemiological study of fixed drug eruption in Pointe-Noire.  

PubMed

A prospective study was conducted over a 27 month period in order to determine the epidemiological profile of fixed drug eruption (FDE) observed during a dermatological consultation at Pointe-Noire. During the study period 54 out of 9,070 persons consulting (0.6%) suffered from clinically diagnosed FDE. The variables studied were: age, sex, medicine and point of sale. The average age of onset was 30 years. The frequency of onset was higher in males (38 patients) than in females (16 patients). The incriminated medicines were: the sulfamides (48 patients) including Cotrimoxazole (45 patients ) and Sulfadoxine and Pyremethamine (3 patients) Coartem(®) + Doliprane(®) (1 patient), Chloramphenicol(®) (1 patient), Amidol(®) (1 patient), Duocotexin(®) + Paracetamol(®) (1 patient), Surquina(®) (1 patient), Amodiaquine(®) (1 patient). The point of sale was illicit (peddlers, markets) for 44 patients; for 10 patients it was a lawful outlet (pharmacies). This study shows that cotrimoxazole bought at illicit points of sale is the main etiology of FDE in the department, confirming that these medicines are counterfeit. The involvement of dermatologists in the fight against the illicit sale of medicines should be made a priority. PMID:23210952

Ognongo-Ibiaho, A N; Atanda, H L

2012-11-01

60

Possible large-N fixed points and naturalness for O(N) scalar fields  

NASA Astrophysics Data System (ADS)

We try to use scale invariance and the large-N limit to find a non-trivial 4D O(N) scalar field model with controlled UV behavior and naturally light scalar excitations. The principle is to fix interactions by requiring the effective action for spacetime dependent background fields to be finite and scale invariant when regulators are removed. We find a line of non-trivial UV fixed points in the large-N limit, parameterized by a dimensionless coupling. They reduce to classical ?phi4 theory when planck ? 0. For planck ? 0, neither action nor measure is scale invariant, but the effective action is. Scale invariance makes it natural to set a mass deformation to zero. The model has phases where O(N) invariance is unbroken or spontaneously broken. Masses of the lightest excitations above the unbroken vacuum are found. We derive a nonlinear equation for oscillations about the broken vacuum. The interaction potential is shown to have a locality property at large N. In 3D, our construction reduces to the line of large-N fixed points in |phi|6 theory.

Krishnaswami, Govind S.

2009-08-01

61

An International Star Intercomparison of Low-Temperature Fixed Points Using Sealed Triple-Point Cells  

NASA Astrophysics Data System (ADS)

An overview of the main results of an international star intercomparison of low-temperature fixed points is given. Between 1997 and 2002, 52 sealed triple-point cells (STPCs) of the thirteen laboratories represented by the authors have been investigated at PTB. The STPCs are used to realise the triple points of hydrogen, neon, oxygen, and argon, respectively, as defining fixed points of the International Temperature Scale of 1990, ITS-90. The melting curves of all STPCs have been measured on the same experimental equipment, adhering strictly to a single measurement program. This protocol enables separation of the effects influencing the melting curves and direct comparison of the thermal behaviour of the STPCs, which are quite different with respect to design, age, gas source, and filling technology. In the paper, emphasis is given to the typical properties of the four fixed-point substances and to the spread of the STPC parameters. Connections between the star intercomparison and completed and on-going international activities, including the CIPM Key Comparisons, are also discussed.

Fellmuth, B.; Berger, D.; Wolber, L.; de Groot, M.; Head, D.; Hermier, Y.; Mao, Y. Z.; Nakano, T.; Pavese, F.; Shkraba, V.; Steele, A. G.; Steur, P. P. M.; Szmyrka-Grzebyk, A.; Tew, W. L.; Wang, L.; White, D. R.

2003-09-01

62

A methodology and design environment for DSP ASIC fixed point refinement  

Microsoft Academic Search

Complex signal processing algorithms are specified in floating point precision. When their hardware implemen- tation requires fixed point precision, type refinement is needed. The paper presents a methodology and design en- vironment for this quantization process. The method uses independent strategies for fixing MSB and LSB weights of fixed point signals. It enables short de- sign cycles by combining the

Radim Cmar; Luc Rijnders; Patrick Schaumont; Serge Vernalde; Ivo Bolsens

1999-01-01

63

24 CFR 50.16 - Decision points for policy actions.  

Code of Federal Regulations, 2010 CFR

... 2009-04-01 2009-04-01 false Decision points for policy actions. 50.16 Section 50...OF ENVIRONMENTAL QUALITY General Policy: Decision Points § 50.16 Decision points for policy actions. Either an EA...

2009-04-01

64

24 CFR 50.16 - Decision points for policy actions.  

Code of Federal Regulations, 2010 CFR

... 2010-04-01 2010-04-01 false Decision points for policy actions. 50.16 Section 50...OF ENVIRONMENTAL QUALITY General Policy: Decision Points § 50.16 Decision points for policy actions. Either an EA...

2010-04-01

65

24 CFR 50.16 - Decision points for policy actions.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 false Decision points for policy actions. 50.16 Section 50.16 ...ENHANCEMENT OF ENVIRONMENTAL QUALITY General Policy: Decision Points § 50.16 Decision points for policy actions. Either an EA and FONSI or...

2013-04-01

66

Tin-filled multi-entrance fixed point  

NASA Astrophysics Data System (ADS)

In this paper, the advantages, design possibilities, performance of the Multi-Entrance Fixed Point (MEFP) concept are described. The purpose of MEFP is to replace equalizing blocks in any temperature-controlled zone with phase transition of matter during melting or freezing. The phase transition in such a calibration is not intended to be the temperature standard itself, but only provides for spatial thermal homogeneity and temporal stability during comparison calibration. Knowing that some of the main uncertainty components in the uncertainty budget of the comparison calibrated thermometer are the radial and axial gradients in the isothermal zone and knowing that comparisons comprise by far the majority of all calibrations, the improvement of speed and quality of calibration is of significant importance. The tin-filled MEFP with multiple entrance tubes, designed in the Laboratory for Process Measurements allows for simultaneous calibration of several thermometers against a standard thermometer. MEFP prototypes filled with other materials and with other design characteristics are pending production. This concept allows the use of modest purity materials to fill the cell, since a standard thermometer is used as the calibration reference. During this investigation, thermometers were calibrated against a standard in the same furnace, using both the standard equalizing block and the MEFP. The measurement results indicate that the use of MEFP decreases the uncertainty contributions from temperature gradients and the stability of the bath by an order of magnitude, compared to the standard equalizing block.

Zvizdi?, D.; Šestan, D.

2013-09-01

67

Fermi Surfaces in General Codimension and a New Controlled Nontrivial Fixed Point  

NASA Astrophysics Data System (ADS)

The energy of a d-dimensional Fermi system typically varies only along dc=1 (“radial”) dimensions. We consider dc=1+? and study a transition to superconductivity in an ? expansion. The nontrivial fixed point describes a scale invariant theory with an effective space-time dimension D=dc+1. Remarkably, the results can be reproduced by the Hertz-Millis action for the superconducting order parameter in higher effective space-time dimensions. We consider possible realizations of the transition at ?=1, which corresponds to a linear Fermi surface in d=3.

Senthil, T.; Shankar, R.

2009-01-01

68

Phase diagram and fixed-point structure of two-dimensional N=1 Wess-Zumino models  

SciTech Connect

We study the phases and fixed-point structure of two-dimensional supersymmetric Wess-Zumino models with one supercharge. Our work is based on the functional renormalization group (RG) formulated in terms of a manifestly off-shell supersymmetric flow equation for the effective action. Within the derivative expansion, we solve the flow of the superpotential also including the anomalous dimension of the superfield. The models exhibit a surprisingly rich fixed-point structure with a discrete number of fixed-point superpotentials. Each fixed-point superpotential is characterized by its number of nodes and by the number of RG-relevant directions. In limiting cases, we find periodic superpotentials and potentials which confine the fields to a compact target space. The maximally IR-attractive fixed point has one relevant direction, the tuning of which distinguishes between supersymmetric and broken phases. For the Wess-Zumino model defined near the Gaussian fixed point, we determine the phase diagram and compute the corresponding ground-state masses.

Synatschke, Franziska; Gies, Holger; Wipf, Andreas [Theoretisch-Physikalisches Institut, Friedrich-Schiller-Universitaet Jena, Max-Wien-Platz 1, D-07743 Jena (Germany)

2009-10-15

69

Common fixed point theorems of Gregus type for weakly compatible mappings satisfying generalized contractive conditions  

NASA Astrophysics Data System (ADS)

We prove a common fixed point theorem of Gregus type for four mappings satisfying a generalized contractive condition in metric spaces using the concept of weak compatibility which generalizes theorems of [I. Altun, D. Turkoglu, B.E. Rhoades, Fixed points of weakly compatible mappings satisfying a general contractive condition of integral type, Fixed Point Theory Appl. 2007 (2007), article ID 17301; A. Djoudi, L. Nisse, Gregus type fixed points for weakly compatible mappings, Bull. Belg. Math. Soc. 10 (2003) 369-378; A. Djoudi, A. Aliouche, Common fixed point theorems of Gregus type for weakly compatible mappings satisfying contractive conditions of integral type, J. Math. Anal. Appl. 329 (1) (2007) 31-45; P. Vijayaraju, B.E. Rhoades, R. Mohanraj, A fixed point theorem for a pair of maps satisfying a general contractive condition of integral type, Int. J. Math. Math. Sci. 15 (2005) 2359-2364; X. Zhang, Common fixed point theorems for some new generalized contractive type mappings, J. Math. Anal. Appl. 333 (2) (2007) 780-786]. We prove also a common fixed point theorem which generalizes Theorem 3.5 of [H.KE Pathak, M.S. Khan, T. Rakesh, A common fixed point theorem and its application to nonlinear integral equations, Comput. Math. Appl. 53 (2007) 961-971] and common fixed point theorems of Gregus type using a strict generalized contractive condition, a property (E.A) and a common property (E.A).

Aliouche, A.

2008-05-01

70

Fixed-Radius Point Counts in Forests: Factors Influencing ...  

Treesearch

... Petit, Lisa J.; Saab,Victoria A.; Martin, Thomas E. Subject: Uncontrolled Keywords: ... A single visit detected approximately 70 percent, and two visits 90 percent, ... Moreover, fixed-radius plots may allow for greater flexibility in study design ...

71

Comparison of three Co-C fixed points constructed using different crucible lining materials  

NASA Astrophysics Data System (ADS)

The melting plateaus of three Co-C fixed points for radiation thermometry with different constructions were measured and compared. Two of the fixed points were of the hybrid type and contained either carbon composite cloth or pyrolytic graphite sheet between the graphite sleeve and the crucible wall. The third fixed point contained only the graphite sleeve. Little difference was found in the shapes of the melting curves between the fixed points. Given a comparison uncertainty of 37 mK (k = 1), there were, however, significant differences in the melting temperatures determined for each of the fixed points. Over three days of measurement, the melting temperature of the fixed point filled using the pyrolytic sheet drifted up by nearly 140 mK.

Todd, A. D. W.; Woods, D. J.

2013-09-01

72

On Extraneous Fixed-Points of the Basic Family of Iteration Functions  

Microsoft Academic Search

Let K denote either the reals or the complex numbers. Consider the root-finding problem for an analytic function f from K into itself via an iteration function F. An extraneous fixed-point of F is a fixed-point different than a root of f. We prove that all extraneous fixed-points of any member of an infinite family of iteration functions, called the

B. Kalantari; Y. Jin

2003-01-01

73

A Fast Fixed-Point Method for Solving Magnetic Field Problems in Media of Hysteresis  

Microsoft Academic Search

The paper proposes a new fixed-point method for solving time-stepping hysteretic field problems. The method is aimed to speed up the convergence of the fixed-point solution and enhance the applicability of the fixed-point iteration. The method makes use of the differential reluctivity and produces a locally convergent solution. A 1-D finite-element procedure is performed to test the method by computing

Emad Dlala; Anouar Belahcen; Antero Arkkio

2008-01-01

74

Homotopy fixed point spectra for closed subgroups of the Morava stabilizer groups  

Microsoft Academic Search

Let G be a closed subgroup of the semi-direct product of the nth Morava stabilizer group Sn with the Galois group of the field extension Fpn\\/Fp. We construct a “homotopy fixed point spectrum” EnhG whose homotopy fixed point spectral sequence involves the continuous cohomology of G. These spectra have the expected functorial properties and agree with the Hopkins-Miller fixed point

Ethan S. Devinatz; Michael J. Hopkins

2004-01-01

75

Improved Thermal Model for the Realization of the Triple Points of Cryogenic Gases as Temperature Fixed Points  

NASA Astrophysics Data System (ADS)

The realization of the triple points of the cryogenic gases hydrogen, neon, oxygen, and argon as temperature fixed points at the highest level of accuracy requires consideration of the special properties of these fixed-point substances, as done in a general measurement protocol published elsewhere. The protocol is applied to the apparatus and methodology used for an international star intercomparison of sealed fixed-point cells. A generalized thermal model is developed to include the coexistence of different solid-liquid interfaces and various thermal resistances. This results in further components in the detailed uncertainty budget for the correction of the measuring power of the thermometer and for the extrapolation to the liquidus point. As a basis for an optimum fixed-point realization, especially an explanation is given why extremely long time periods may be necessary for the thermal recovery after pulses of the intermittent heating used for the calorimetric method.

Wolber, L.; Fellmuth, B.

2011-01-01

76

Triple point of e-deuterium as an accurate thermometric fixed point  

SciTech Connect

The triple point of deuterium (18.7/sup 0/K) is the only possibility for excluding vapor pressure measurements in the definition of a temperature scale based on fixed points between 13.81 and 24.562/sup 0/K. This paper reports an investigation made at the Istituto di Metrologia and Mound Laboratory, using extremely pure deuterium directly sealed at the production plant into small metal cells. The large contamination by HD of commercially available gas, that cannot be accounted and corrected for due to its increase in handling, was found to be very stable with time after sealing in IMGC cells. HD contamination can be limited to less than 100 ppM in Monsanto cells, both with n-D/sub 2/ and e-D/sub 2/, when filled directly from the thermal diffusion column and sealed at the factory. e-D/sub 2/ requires a special deuterated catalyst. The triple point temperature of e-D/sub 2/ has been determined to be: T(NPL-IPTS-68) = 18.7011 +- 0.002/sup 0/K. 20 refs., 3 figs., 2 tabs.

Pavese, F.; McConville, G.T.

1986-01-01

77

On the Use of the Co C Fixed Point for Calibration of Pt/Pd Thermocouples  

NASA Astrophysics Data System (ADS)

At INRIM, different Co C fixed-point cells have been constructed and investigated. Two cells of different design and volume and filled with highly pure cobalt (99.998%) were used to extend the fixed-point calibration of five Pt/Pd thermocouples that had been previously calibrated at the triple point of water and at the fixed points of In, Sn, Zn, Al, and Ag. The calibration at the Cu point was also added during this exercise. Because a previous calibration from 962 °C up to 1,500°C against the local standard radiation thermometer was available, a comparison was possible with the Co C fixed-point calibration. Agreement within 0.10 °C was found when the value of 1,324.0 °C, the same value proposed for the Co C point to be included as a secondary reference point of the ITS-90, was assumed.

Astrua, M.; Battuello, M.; Girard, F.

2008-02-01

78

FIXED POINTS FOR SOME NON-OBVIOUSLY CONTRACTIVE OPERATORS  

Microsoft Academic Search

Abstract. The use of K-normed spaces gives us the possibility to prove that a,xed point theorem due to B. Luo is equivalent to the Banach Contraction Principle. This conrms,the conspiracy among,xed point theorems. Moreover the theorem,of Lou is improved and extended to dierent,contexts. A coun- terexample about the,xed points of the sum of a contraction and an integral operator is

E. De Pascale; L. De Pascale

79

The succinonitrile triple-point standard: a fixed point to improve the accuracy of temperature measurements in the clinical laboratory.  

PubMed

In an investigation of the melting and freezing behavior of succinonitrile, the triple-point temperature was determined to be 58.0805 degrees C, with an estimated uncertainty of +/- 0.0015 degrees C relative to the International Practical Temperature Scale of 1968 (IPTS-68). The triple-point temperature of this material is evaluated as a temperature-fixed point, and some clinical laboratory applications of this fixed point are proposed. In conjunction with the gallium and ice points, the availability of succinonitrile permits thermistor thermometers to be calibrated accurately and easily on the IPTS-68. PMID:6861344

Mangum, B W

1983-07-01

80

Common fixed point theorems for maps under a contractive condition of integral type  

Microsoft Academic Search

Two common fixed point theorems for mapping of complete metric space under a general contractive inequality of integral type and satisfying minimal commutativity conditions are proved. These results extend and improve several previous results, particularly Theorem 4 of Rhoades [B.E. Rhoades, Two fixed point theorems for mappings satisfying a general contractive condition of integral type, Int. J. Math. Math. Sci.

A. Djoudi; F. Merghadi

2008-01-01

81

Comparison of realizations of Re-C fixed points filled and measured at NPL and NRC  

NASA Astrophysics Data System (ADS)

A Re-C fixed point was filled at the National Physical Laboratory (NPL), UK and its melting temperature compared to a fixed point that had been filled previously at NPL. Both of these fixed points were of the hybrid type and used a purified graphite foil between the sacrificial graphite sleeve and the outer crucible. The melting temperatures of these two fixed points were compared and found to agree within the comparison uncertainties. Another Re-C fixed point was filled at the National Research Council (NRC), Canada. This fixed point was also of the hybrid type but contained carbon-composite sheet as the liner between the sleeve and the outer crucible. The melting temperatures of the fixed point filled at NPL and the one filled at NRC were compared and found to agree within the uncertainties of the comparison. When the ITS-90 temperatures at the Re-C melting point (~ 2474 °C) measured at NPL were compared to those measured at NRC they were also found to agree within the uncertainties of their respective scales.

Todd, A. D. W.; Lowe, D. H.; Dong, W.; Woods, D. J.

2013-09-01

82

Gauge invariant and gauge fixed actions for various higher-spin fields from string field theory  

NASA Astrophysics Data System (ADS)

We propose a systematic procedure for extracting gauge invariant and gauge fixed actions for various higher-spin gauge field theories from covariant bosonic open string field theory. By identifying minimal gauge invariant part for the original free string field theory action, we explicitly construct a class of covariantly gauge fixed actions with BRST and anti-BRST invariance. By expanding the actions with respect to the level N of string states, the actions for various massive fields including higher-spin fields are systematically obtained. As illustrating examples, we explicitly investigate the level N?3 part and obtain the consistent actions for massive graviton field, massive 3rd rank symmetric tensor field, or anti-symmetric field. We also investigate the tensionless limit of the actions and explicitly derive the gauge invariant and gauge fixed actions for general rank n symmetric and anti-symmetric tensor fields.

Asano, Masako

2013-03-01

83

New Filling Technique and Performance Evaluations of the Cr3C2-C Peritectic Fixed Point  

Microsoft Academic Search

The Cr3C2-C peritectic fixed point was investigated to test its capability to serve as a practical high-temperature fixed point. An improved filling technique where C\\/C sheet works as a wick and graphite paper as a hopper was applied successfully, and the long-term stability of the peritectic cell was evaluated by means of radiation thermometry. The repeatability of the melting point

N. Sasajima; D. Lowe; C. Bai; Y. Yamada; C. Ara

2011-01-01

84

Fixed Points of Type Constructors and Primitive Recursion  

Microsoft Academic Search

For nested or heterogeneous datatypes, terminating recur- sion schemes considered so far have been instances of iteration, exclud- ing ecien t denitions of xed-p oint unfolding. Two solutions of this problem are proposed: The rst one is a system with equi-recursive non- strictly positive type constructors of arbitrary nite kinds, where xed- point unfolding is computationally invisible due to its

Andreas Abel; Ralph Matthes

2004-01-01

85

High-temperature fixed points for pre-launch calibration of earth observing sensors  

NASA Astrophysics Data System (ADS)

High-temperature fixed points of metal-carbon systems, currently the target of a project in the international thermometry standards community, is also of high interest for pre-launch radiometric calibration of hyperspectral earth observing sensor in the blue wavelengths, where the conventional copper fixed point fails to supply sufficient radiance. For such a calibration, a fixed-point possibly around 2000 K is desired. One requirement for application of the high-temperature blackbody fixed-point cell to remote sensor calibration is to increase the radiating source aperture diameter to a size large enough to target with a radiance comparator based on a grating monochromator. In this presentation, a fixed-point cell of Co-C eutectic (1597 K) for remote sensor calibration application is described. An enlarged 7-mm aperture design is employed for the fixed-point cell while at the same time retaining the outer dimension to fit in existing fixed-point furnaces. The observed plateaux showed temperature and repeatability comparable to conventional 3-mm aperture cells, while cavity breakages indicates the need for improved robustness in the crucible design. Extension of the technique to Pt-C eutectic (2011 K) or Cr3C2-C peritectic (2100 K) systems, and subsequent application to calibration of the HISUI sensor is envisaged.

Yamada, Yoshiro; Ishii, Juntaro

2011-09-01

86

A fixed-point framework for launch vehicle ascent guidance  

Microsoft Academic Search

Recent interests in responsive launch have highlighted the need for rapid and fully automated ascent guidance planning and guidance parameter generation for launch vehicles. This dissertation aims at developing methodology and algorithms for on-demand generation of optimal launch vehicle ascent trajectories from lift-off to achieving targeting conditions outside the atmosphere. The entire ascent trajectory from lift-off to final target point

Lijun Zhang

2006-01-01

87

Perceiving depth in point-light actions  

Microsoft Academic Search

The present study investigates how observers assign depth in point-light figures, by manipulating spatiotemporal characteristics\\u000a of the stimuli. Previous research on the perception of point-light walkers revealed bistability (i.e., that a point-light\\u000a walker is perceived as either facing the viewer or facing away from the viewer) and the presence of a perceptual bias (i.e.,\\u000a a tendency to perceive the figure

Jan Vanrie; Karl Verfaillie

2006-01-01

88

Cryogenic Temperature Sealed Fixed Points: a New-Generation of Modular Cells at IMGC  

Microsoft Academic Search

Mainly in the frame of the European Project MULTICELLS, IMGC developed a new generation of sealed temperature fixed-point cells (M-cells), based on the principle of modular elements, each containing one substance, several of which can be mounted in a copper frame of reduced dimensions where thermometers are fitted. The device being modular, the user can select up to six fixed

F. Pavese; D. Ferri; I. Peroni; A. Pugliese; P. P. M. Steur; B. Fellmuth; D. Head; L. Lipinski; A. Peruzzi; A. Szmyrka Grzebyk; L. Wolber

2003-01-01

89

Camera-based investigation of high-temperature fixed points for radiometric application  

NASA Astrophysics Data System (ADS)

A radiance camera was used to investigate the radiation field emitted by high-temperature blackbodies and fixed-point cavities up to temperatures of 3000 K. In a first step the applicability of the camera to measure the spectral radiance at such high temperatures was investigated. In a second step the radiation characteristics of several sources were studied using the camera system, in particular, large area fixed-point blackbodies of Cu, Pt-C and ZrC-C. Especially for the ZrC-C fixed points the radiation field at the cavity opening was found to be non-uniform. This observation explains systematic differences in the plateau shape of large aperture eutectic fixed-point cells for radiometers with different fields of view. Using the two-dimensional radiance distribution measured with the camera system the deviation of the temperatures measured with interference filter radiometers and radiation thermometers was studied.

Anhalt, K.; Lindner, D.; Krüger, U.; Schmidt, F.; Hartmann, J.

2009-08-01

90

Numerical solution of moment-transformed population balance equation with fixed quadrature points  

Microsoft Academic Search

A solution to the moment-transformed population balance equation is presented. The method is based on calculating integrals with fixed quadrature points and corresponding moment-conserving weights. The quadrature points are fixed in the sense that their relative locations along the internal coordinate are determined based on a pre-determined condition. One such condition is choosing them as zeros of orthogonal polynomials. The

Ville Alopaeus; Marko Laakkonen; Juhani Aittamaa

2006-01-01

91

LETTER TO THE EDITOR: Argon pressure is maintained in an aluminium thermometric fixed-point cell  

NASA Astrophysics Data System (ADS)

The argon and helium pressure in two types of temperature fixed-point cell enclosure has been measured for over two weeks. It was found that there was no significant change in the argon pressure over this time, in contrast to the report of Ancsin (2003 Metrologia 40 232-4). Helium was found to diffuse out of the cell as expected. We conclude that argon is a suitable 'back-fill' gas for fixed-point cells.

Petchpong, Patchariya; Head, David I.

2007-12-01

92

Exact finite-difference schemes for first order differential equations having three distinct fixed-points  

Microsoft Academic Search

We construct nonstandard finite-difference (NSFD) schemes that provide exact numerical methods for a first-order differential equation having three distinct fixed-points. An explicit, but also nonexact, NSFD scheme is also constructed. It has the feature of preserving the critical properties of the original differential equation such as the positivity of the solutions and the stability behavior of the three fixed-points.

Lih-Ing W. Roeger; Ronald E. Mickens

2007-01-01

93

Nonstandard finite difference schemes for differential equations with n+1 distinct fixed-points  

Microsoft Academic Search

We construct nonstandard finite-difference schemes that provide explicit numerical methods for a first-order differential equation with n+1 distinct fixed-points that include 0,where 0 = a0 < a1 < a2 < … < an and ? is either 1 or ? 1. The numerical method is explicit and preserves the critical properties of the differential equation such as the positivity of the solutions, the stability behaviour of all fixed-points, and the monotonicity

Lih-Ing W. Roeger

2009-01-01

94

NRG study of a generalized Anderson impurity model with non Fermi liquid fixed point.  

NASA Astrophysics Data System (ADS)

We study with the Wilson numerical renormalization group method the phase diagram of a twofold orbitally degenerate doubly occupied Anderson impurity model. Strikingly, the model presents a non-trivial fixed point, similar to that of the two-impurity Kondo problem, which separates a Kondo-screened regime from a Kondo-unscreened one. This novel fixed point is even more robust than that, since it can only be destabilized by orbital or gauge symmetry breaking. We calculate the impurity spectral function (DOS) which shows quite an interesting behavior across the fixed point. In the Kondo screened regime and close to the fixed point the DOS displays, riding on top of a broader peak, a very narrow resonance at the Fermi level. The resonance shrinks upon approaching the fixed point, and finally disappears at the fixed point. Beyond that, in the Kondo-unscreened regime, the narrow resonance is now replaced by a narrow pseudogap gradually opening up. The doubly occupied model has electron-hole symmetry; however the novel fixed point exists even without that symmetry. In general the DOS pseudogap in the Kondo-unscreened regime gets partly filled in, but will still pin the chemical potential. While this impurity model is interesting per se, we are pursuing its use as a tool to understand, via Dynamical Mean Field Theory, the behavior of a strongly correlated lattice model close to the Mott transition. We argue that this lattice model should encounter the non-trivial fixed point just before the Mott transition and react to its instability by spontaneous generation of a superconducting order parameter.

de Leo, Lorenzo; Fabrizio, Michele

2004-03-01

95

Evaluation of the Pd-C eutectic fixed point and the Pt/Pd thermocouple  

NASA Astrophysics Data System (ADS)

A Pd-C eutectic fixed point cell (1492 °C) was constructed to investigate its utility for thermocouple calibration. The primary aim of the study was to evaluate the long-term stability, immersion characteristics (influence of heat conduction along the thermocouple stem) and robustness of a Pd-C fixed point using a Pt/Pd thermocouple, especially constructed for this purpose. The performance of both devices at this relatively high temperature could therefore be tested. The melting and freezing plateaux at the Pd-C eutectic point were measured using the Pt/Pd thermocouple. The total exposure to the Pd-C melting temperature was about 850 h for the fixed point cell and 550 h for the thermocouple. The standard deviations of the melting and freezing points were 1.03 µV (0.041 °C) and 0.77 µV (0.031 °C) respectively. The emfs of the thermocouple at the melting point were observed to drift by about 0.1 °C. The immersion measurements show that for the current cell design, the measuring junction should be at most 30 mm from the bottom of the thermowell to be properly immersed. The long-term performance and robustness of the fixed point indicate a promising future for its use as a fixed point for calibration of noble metal thermocouples.

Pearce, J. V.; Ogura, H.; Izuchi, M.; Machin, G.

2009-10-01

96

Confronting the IR fixed point cosmology with high-redshift observations  

NASA Astrophysics Data System (ADS)

We use high-redshift type Ia supernova and compact radio source data in order to test the infrared (IR) fixed point model of the late Universe which was proposed recently. It describes a cosmology with a time dependent cosmological constant and Newton constant whose dynamics arises from an underlying renormalization group flow near an IR-attractive fixed point. Without any fine-tuning or quintessence field it yields OmegaM = OmegaLambda = 1/2. Its characteristic t4/3-dependence of the scale factor leads to a distance redshift relation whose predictions are compared both to the supernova and to the radio source data. According to the chi2 test, the fixed point model reproduces the data at least as well as the best-fit (Friedmann Robertson Walker) standard cosmology. Furthermore, we extend the original fixed point model by assuming that the fixed point epoch is preceded by an era with constant G and Lambda. By means of a Monte Carlo simulation we show that the data expected from the forthcoming SNAP satellite mission could detect the transition to the fixed point regime provided it took place at a redshift of less than about 0.5.

Bentivegna, Eloisa; Bonanno, Alfio; Reuter, Martin

2004-01-01

97

Analysis of fixed point FFT for Fourier domain optical coherence tomography systems.  

PubMed

Optical coherence tomography (OCT) is a new imaging modality gaining popularity in the medical community. Its application includes ophthalmology, gastroenterology, dermatology etc. As the use of OCT increases, the need for portable, low power devices also increases. Digital signal processors (DSP) are well suited to meet the signal processing requirements of such a system. These processors usually operate on fixed precision. This paper analyzes the issues that a system implementer faces implementing signal processing algorithms on fixed point processor. Specifically, we show the effect of different fixed point precisions in the implementation of FFT on the sensitivity of Fourier domain OCT systems. PMID:19965018

Ali, Murtaza; Parlapalli, Renuka; Magee, David P; Dasgupta, Udayan

2009-01-01

98

Investigation of low-temperature fixed points by an international star intercomparison of sealed triple-point cells  

NASA Astrophysics Data System (ADS)

An overview of the results of an international star intercomparison of low-temperature fixed points is given. Between 1997 and 2005, 68 sealed triple-point cells (STPCs) of the twelve laboratories represented by the authors were investigated at PTB. The STPCs are used to realize the triple points of hydrogen, neon, oxygen and argon as defining fixed points of the International Temperature Scale of 1990, ITS-90. The melting curves (MCs) of all STPCs have been measured on the same experimental equipment, adhering strictly to a single measurement program. This protocol enables separation of the effects influencing the MCs and direct comparison of the thermal behaviour of the STPCs, which are quite different with respect to design, age, gas source and filling technology. In the paper, special emphasis is given to the spread of the liquidus-point temperatures and to the uncertainty of their determination. Connections between the star intercomparison and completed and ongoing international activities are also discussed.

Fellmuth, B.; Wolber, L.; Head, D. I.; Hermier, Y.; Hill, K. D.; Nakano, T.; Pavese, F.; Peruzzi, A.; Rusby, R. L.; Shkraba, V.; Steele, A. G.; Steur, P. P. M.; Szmyrka-Grzebyk, A.; Tew, W. L.; Wang, L.; White, D. R.

2012-06-01

99

Thermal Analysis of the Heater-Induced Realization of the Tin Fixed Point  

NASA Astrophysics Data System (ADS)

In this article, work concerning the thermal analysis of the tin fixed-point is reported. First, the development of a new fixed-point furnace is described. Improvements in the design of the furnace and in the control system enable measurement of the heater power during the phase change. The furnace is sufficiently thermally insulated to produce excellent uniformity and stability, leading to high quality freeze-initiation and minimal thermal influences on the freezing point. By employing the improved furnace and newly-fabricated tin fixed-point cells, the start and end of the melting plateau and the end of the freezing plateau were accurately determined, enabling reliable evaluation of the liquid fraction during the realization of the tin fixed-point compared to conventional methods. Two open-type tin fixed-point cells were fabricated using high-purity tin that was chemically analyzed for impurity content. Thermal analysis results of freezing-point depression are compared to those based on the chemical analysis.

Yamazawa, K.; Widiatmo, J. V.; Arai, M.

2007-12-01

100

Calibration of Radiation Thermometry Fixed Points Using Au/Pt Thermocouples  

NASA Astrophysics Data System (ADS)

At NMIA, radiation thermometers are calibrated by comparison with a number of reference radiation thermometers which are themselves calibrated using fixed-point cells on the ITS-90 temperature scale (In, Sn, Zn, Al, Ag, and Au). The suitability of NMIA fixed-point cells used for standard platinum resistance thermometers (SPRTs) is evaluated by the comparison of ensembles of cells at each fixed point, and by participation in the international BIPM Key-Comparisons K3 and K4. However, the NMIA fixed-point cells used for radiation thermometry are typically much smaller (only 110 mm in length) and the thermowell length immersed in the metal much shorter (85 mm) than those used for SPRTs. Further, the insulation at the front of the crucible needs to accommodate the F/10 viewing cone of the radiation thermometers, so significant temperature gradients exist near the top of the crucible. As a consequence, the conduction errors obtained using SPRTs are too large to be of practical use. A convenient methodology based on the use of a Au/Pt thermocouple, together with a protective tube assembly to reduce conduction errors, has been developed. This allows the convenient measurement of the phase transition temperature traceable, at the 30 mK level, to the fixed-point cells used at NMIA to realize and maintain the ITS-90 scale. As the measurements are made in situ, the temperature environment, and hence the geometry and formation of the liquid-solid interface during melting and freezing, are similar to that occurring when used with radiation thermometers. Results are presented for ITS-90 fixed points up to Ag, establishing formal traceability of radiation thermometry fixed-point cells to NMIA's primary ITS-90 cells.

Jahan, F.; Ballico, M. J.

2011-01-01

101

Procedure for the Impurity-Related Correction at the Indium Fixed-Point  

NASA Astrophysics Data System (ADS)

Determining the influence of impurities on the fixed-point temperatures of the ITS-90 requires the completion of several tasks. In this paper, the progress made at Physikalisch-Technische Bundesanstalt (PTB) and BAM Federal Institute for Materials Research and Testing is presented and remaining questions are discussed. The projected characterization procedure at PTB, which is based on the established SIE method (sum of the individual estimates), using a new indium fixed-point cell is described as an example. This procedure includes an SI-traceable chemical analysis of the material in the fixed-point cell with sufficiently low uncertainties, the individual experimental determination of the influence of the quantified impurities on the fixed-point temperature, and the establishment of direct links to the phase-transition temperatures of the national standard and of an assumed material of ideal purity. A characteristic difference to the common practice is the chemical analysis of the fixed-point metal being done after determining the cell's freezing temperature. This allows for the detection and consideration of contamination and purification effects due to the filling process, or due to the contact with the carbon crucible and other parts of the fixed-point cell. A chemical analysis of an indium fixed-point was carried out by BAM with relative measurement uncertainties below 30 % which have not been previously achieved. The results provide evidence for the precipitation of some impurities, which is apparently inconsistent with the corresponding binary phase diagrams, but was explained in a recent publication. Implications for the use of the SIE method shall be described briefly at the end.

Rudtsch, S.; Gusarova, T.; Aulich, A.; Fahr, M.; Fischer, J.; Kipphardt, H.; Matschat, R.; Panne, U.

2011-01-01

102

A Concerted International Project to Establish High-Temperature Fixed Points for Primary Thermometry  

NASA Astrophysics Data System (ADS)

Research into high-temperature fixed points above 1,100°C has made significant progress since they were first reported in 1999. In particular, it has been established that single cells are repeatable at the sub-50 mK level, and intra-cell reproducibility at the 100 mK level has been demonstrated even at temperatures as high as 2,500°C. The fixed points have been used to compare temperature and radiometry scales over a wide temperature range, and are being developed and established as secondary references for thermocouple calibrations. However, before they can be fully accepted as primary temperature references, much work remains to be done, namely: (1) Establishment of long-term stability of the fixed-point temperature; (2) Development of robust procedures for the reliable construction of the fixed-point cells (to ensure routine intra-cell reproducibility of 100 mK); (3) Demonstration of long-term robustness of the fixed-point cells; (4) Assignment of thermodynamic temperatures to a selected set of fixed points; (5) Agreement and acceptance of these temperature values by the CCT; (6) Agreed methods on how to take full utility of these new fixed points into any future International Temperature Scale (ITS)—or the current ITS-90 via an addendum to the mise en pratique for the definition of the kelvin. To ensure that this work progresses to completion in a reasonable time frame, a research project, under the auspices of the CCT-WG5, has been formulated and is currently in progress with the aim of achieving the above mentioned targets by 2012. This article will describe this project and detail partner contributions.

Machin, G.; Bloembergen, P.; Hartmann, J.; Sadli, M.; Yamada, Y.

2007-12-01

103

Intercomparison of Copper Fixed-Point Cells by Using Pt/Pd Thermocouples  

NASA Astrophysics Data System (ADS)

The objective of the EUROMET Project No. 844 in the field of thermometry was the intercomparison of the freezing temperatures of the copper fixed-point cells ( t 90 = 1084.62°C) of the participating laboratories by using Pt/Pd thermocouples. For most of the 13 participating laboratories, agreement of the freezing temperatures of the different copper fixed points within ±0.06 K was found. Furthermore, the results of the intercomparison show that Pt/Pd thermocouples are suitable for use as transfer standards for the dissemination of temperatures and to approximate the ITS-90, at least up to the freezing point of copper.

Edler, F.; Anagnostou, M.; Bojkovski, J.; Gaita, S.; García, C.; Grudniewicz, E.; Helgesen, F.; Ivarsson, J.; Pauza, A.; Rosenkranz, P.; Smid, M.; Weckström, T.; Zvizdic, D.

2008-02-01

104

Large- and Small-Aperture Fixed-Point Cells of Cu, Pt C, and Re C  

NASA Astrophysics Data System (ADS)

Extending the application of metal (carbide) carbon eutectic fixed-point cells to radiometry, e.g., for measurements in irradiance mode, requires fixed-point cells with large apertures. In order to make large-aperture cells more readily usable in furnace systems with smaller furnace tubes commonly used for small-aperture fixed-point cells, a novel cell design was developed. For each of Cu, Pt C, and Re C fixed points, two types of fixed-point cells were manufactured, the small- and large-aperture cell. For Pt C and Re C, the large-aperture cells were filled with a hyper-eutectic metal carbon mixture; for the small cells, a hypo-eutectic mixture was used for filling. For each material, the small and large cells were compared with respect to radiometric differences. Whereas plateau shape and melting temperature are in good agreement for the small- and large-aperture Cu cells, a larger difference was observed between small- and large-aperture cells of Pt C and Re C, respectively. The origin of these observations, attributed to the temperature distribution inside the furnace, ingot contamination during manufacture, and non-uniform ingot formation for the larger cells, is discussed. The comparison of measurements by a radiation thermometer and filter radiometer of the Re C and Pt C large-aperture cells showed large differences that could be explained only by a strong radiance distribution across the cavity bottom. Further investigations are envisaged to clarify the cause.

Anhalt, Klaus; Wang, Yunfen; Yamada, Yoshiro; Hartmann, Jürgen

2008-06-01

105

Fixed point theorems for set-valued contractions in complete metric spaces  

NASA Astrophysics Data System (ADS)

The fixed point theory of set-valued contractions which was initiated by Nadler [S.B. Nadler Jr., Multi-valued contraction mappings, Pacific J. Math. 30 (1969) 475-488] was developed in different directions by many authors, in particular, by [S. Reich, Fixed points of contractive functions, Boll. Unione Mat. Ital. 5 (1972) 26-42; N. Mizoguchi, W. Takahashi, Fixed point theorems for multivalued mappings on complete metric spaces, J. Math. Anal. Appl. 141 (1989) 177-188; Y. Feng, S. Liu, Fixed point theorems for multi-valued contractive mappings and multi-valued Caristi type mappings, J. MathE Anal. Appl. 317 (2006) 103-112]. In the present paper, the concept of contraction for set-valued maps in metric spaces is introduced and the conditions guaranteeing the existence of a fixed point for such a contraction are established. One of our results essentially generalizes the Nadler and Feng-Liu theorems and is different from the Mizoguchi-Takahashi result. The second result is different from the Reich and Mizoguchi-Takahashi results. The method used in the proofs of our results is inspired by Mizoguchi-Takahashi and Feng-Liu's ideas. Comparisons and examples are given.

Klim, D.; Wardowski, D.

2007-10-01

106

One-parameter semigroups of analytic functions, fixed points and the Koenigs function  

NASA Astrophysics Data System (ADS)

Analogues of the Berkson-Porta formula for the infinitesimal generator of a one-parameter semigroup of holomorphic maps of the unit disc into itself are obtained in the case when, along with a Denjoy-Wolff point, there also exist other fixed points. With each one-parameter semigroup a so-called Koenigs function is associated, which is a solution, common for all elements of the one-parameter semigroup, of a certain functional equation (Schröder's equation in the case of an interior Denjoy-Wolff point and Abel's equation in the case of a boundary Denjoy-Wolff point). A parametric representation for classes of Koenigs functions that takes account of the Denjoy-Wolff point and other fixed points of the maps in the one-parameter semigroup is presented. Bibliography: 19 titles.

Goryainov, Victor V.; Kudryavtseva, Olga S.

2011-07-01

107

One-parameter semigroups of analytic functions, fixed points and the Koenigs function  

SciTech Connect

Analogues of the Berkson-Porta formula for the infinitesimal generator of a one-parameter semigroup of holomorphic maps of the unit disc into itself are obtained in the case when, along with a Denjoy-Wolff point, there also exist other fixed points. With each one-parameter semigroup a so-called Koenigs function is associated, which is a solution, common for all elements of the one-parameter semigroup, of a certain functional equation (Schroeder's equation in the case of an interior Denjoy-Wolff point and Abel's equation in the case of a boundary Denjoy-Wolff point). A parametric representation for classes of Koenigs functions that takes account of the Denjoy-Wolff point and other fixed points of the maps in the one-parameter semigroup is presented. Bibliography: 19 titles.

Goryainov, Victor V; Kudryavtseva, Olga S [Volzhsky Institute of Humanities, Volgograd Region, Volzhsky (Russian Federation)

2011-07-31

108

Group Action Recognition Using Space-Time Interest Points  

Microsoft Academic Search

Group action recognition is a challenging task in computer vision due to the large complexity induced by multiple motion patterns.\\u000a This paper aims at analyzing group actions in video clips containing several activities. We combine the probability summation\\u000a framework with the space-time (ST) interest points for this task. First, ST interest points are extracted from video clips\\u000a to form the

Qingdi Wei; Xiaoqin Zhang; Yu Kong; Weiming Hu; Haibin Ling

2009-01-01

109

Fe-C eutectic fixed-point cells for contact thermometry: an investigation and comparison  

NASA Astrophysics Data System (ADS)

Five iron-carbon (Fe-C) eutectic fixed-point cells have been constructed between NPL and LNE-Cnam to investigate the robustness and to measure the agreement of their melting temperatures. Each cell was constructed with a different selection of materials sourced by NPL and LNE-Cnam. The measured emfs at the Fe-C fixed-point temperature (~1153 °C), compared between cells, agree within around 1.98 µV (~90 mK), where the most important contribution to the uncertainty of each measurement is the inhomogeneity associated with the measuring Pt/Pd thermocouple. This demonstrates that these cells are suitable for use as secondary fixed-point cells in contact thermometry but the robustness of the presented cells is not found to be sufficient for maintaining their integrity during repeated cycling procedures.

Elliott, C. J.; Pearce, J. V.; Failleau, G.; Deuzé, T.; Briaudeau, S.; Sadli, M.; Machin, G.

2012-02-01

110

Fixed point theorems for multi-valued contractions in complete metric spaces  

NASA Astrophysics Data System (ADS)

In this paper the concept of a contraction for multi-valued mappings in a metric space is introduced and the existence theorems for fixed points of such contractions in a complete metric space are proved. Presented results generalize and improve the recent results of Y. Feng, S. Liu [Y. Feng, S. Liu, Fixed point theorems for multi-valued contractive mappings and multi-valued Caristi type mappings, J. Math. Anal. Appl. 317 (2006) 103-112], D. Klim, D. Wardowski [D. Klim, D. Wardowski, Fixed point theorems for set-valued contractions in complete metric spaces, J. Math. Anal. Appl. 334 (2007) 132-139] and several others. The method used in the proofs of our results is new and is simpler than methods used in the corresponding papers. Two examples are given to show that our results are genuine generalization of the results of Feng and Liu and Klim and Wardowski.

Ciric, Ljubomir

2008-12-01

111

A least-squares fixed-point iterative algorithm for multiple illumination photoacoustic tomography.  

PubMed

The optical absorption of tissues provides important information for clinical and pre-clinical studies. The challenge in recovering optical absorption from photoacoustic images is that the measured pressure depends on absorption and local fluence. One reconstruction approach uses a fixed-point iterative technique based on minimizing the mean-squared error combined with modeling of the light source to determine optical absorption. With this technique, convergence is not guaranteed even with an accurate measure of optical scattering. In this work we demonstrate using simulations that a new multiple illumination least squares fixed-point iteration algorithm improves convergence - even with poor estimates of optical scattering. PMID:24156078

Harrison, Tyler; Shao, Peng; Zemp, Roger J

2013-09-24

112

Luttinger liquid fixed point for a two-dimensional flat Fermi surface  

NASA Astrophysics Data System (ADS)

We consider a system of two-dimensional interacting fermions with a flat Fermi surface. The apparent conflict between Luttinger and non-Luttinger liquid behaviors found through different approximations is resolved by showing the existence of a line of nontrivial fixed points, for the renormalization group (RG) flow, corresponding to Luttinger liquid behavior; the presence of marginally relevant operators can cause flow away from the fixed point. The analysis is nonperturbative and based on the implementation, at each RG iteration, of Ward identities obtained from local phase transformations depending on the Fermi surface side, implying the partial vanishing of the beta function.

Mastropietro, Vieri

2008-05-01

113

Fixed point results of locally contractive mappings in ordered quasi-partial metric spaces.  

PubMed

Fixed point results for a self-map satisfying locally contractive conditions on a closed ball in an ordered 0-complete quasi-partial metric space have been established. Instead of monotone mapping, the notion of dominated mappings is applied. We have used weaker metric, weaker contractive conditions, and weaker restrictions to obtain unique fixed points. An example is given which shows that how this result can be used when the corresponding results cannot. Our results generalize, extend, and improve several well-known conventional results. PMID:24062629

Shoaib, Abdullah; Arshad, Muhammad; Ahmad, Jamshaid

2013-08-25

114

Fixed Point Results of Locally Contractive Mappings in Ordered Quasi-Partial Metric Spaces  

PubMed Central

Fixed point results for a self-map satisfying locally contractive conditions on a closed ball in an ordered 0-complete quasi-partial metric space have been established. Instead of monotone mapping, the notion of dominated mappings is applied. We have used weaker metric, weaker contractive conditions, and weaker restrictions to obtain unique fixed points. An example is given which shows that how this result can be used when the corresponding results cannot. Our results generalize, extend, and improve several well-known conventional results.

Arshad, Muhammad; Ahmad, Jamshaid

2013-01-01

115

A least-squares fixed-point iterative algorithm for multiple illumination photoacoustic tomography  

PubMed Central

The optical absorption of tissues provides important information for clinical and pre-clinical studies. The challenge in recovering optical absorption from photoacoustic images is that the measured pressure depends on absorption and local fluence. One reconstruction approach uses a fixed-point iterative technique based on minimizing the mean-squared error combined with modeling of the light source to determine optical absorption. With this technique, convergence is not guaranteed even with an accurate measure of optical scattering. In this work we demonstrate using simulations that a new multiple illumination least squares fixed-point iteration algorithm improves convergence - even with poor estimates of optical scattering.

Harrison, Tyler; Shao, Peng; Zemp, Roger J.

2013-01-01

116

Reference in Action: Links between Pointing and Language  

ERIC Educational Resources Information Center

|When referring to things in the world, speakers produce utterances that are composites of speech and action. Pointing gestures are a pervasive part of such composite utterances, but many questions remain about exactly how pointing is integrated with speech. In this dissertation I present three strands of research that investigate relations of…

Cooperrider, Kensy Andrew

2011-01-01

117

Bilateral Comparison of Aluminum Fixed-Point Cells Using Standard Platinum Resistance Thermometer  

NASA Astrophysics Data System (ADS)

The objective of Project EURAMET 1114 (Bilateral comparison of a freezing point of aluminum) in the field of thermometry is to compare realization of a freezing point of aluminum (660.323 °C) between the Dutch national laboratory VSL and the Slovenian national laboratory MIRS/UL-FE/LMK using a long-stem 25 ? standard platinum resistance thermometer (SPRT). Both laboratories had participated in a number of inter-comparisons on the level of EURAMET and also on BIPM CCT level (VSL). MIRS/UL-FE/LMK laboratory recently acquired a new fixed-point cell which had to be validated in the process of intercomparison. A quartz-sheathed SPRT was selected and calibrated at MIRS/UL-FE/LMK at the aluminum freezing point and at the water triple point. A second set of measurements was made on the same SPRT and at the same fixed points at VSL (NL). After its return, the SPRT was again recalibrated at MIRS/UL-FE/LMK. In the comparison the W value of the SPRT was used. The results of the internal and external intercomparisons confirmed that the new aluminum cell of the MIRS/UL/FE-LMK realizes a temperature that agrees with the VSL aluminum fixed point within the uncertainty limits of both laboratories. Furthermore, the results of this bilateral-comparison were compared with results that both laboratories achieved in the EURAMET K4 (Project 820) and were found to be in agreement.

Bojkovski, J.; Peruzzi, A.; Bosma, R.; Batagelj, V.

2011-08-01

118

Experimental Investigation of the Cr 3 C 2 –C Peritectic Fixed Point  

Microsoft Academic Search

The Cr3C2–C (1,826°C) peritectic point was investigated for its performance as a high-temperature fixed point. Dependence on the impurity\\u000a content was observed, although it was less severe for the higher of the two equilibrium temperatures obtained with the same\\u000a cell, the Cr3C2–C peritectic point, than for the lower, the Cr7C3–Cr3C2 eutectic point. Thermal history had an effect on the melting

W. Zheng; Y. Yamada; Y. Wang

2008-01-01

119

Fixing the fixed-point system—Applying Dynamic Renormalization Group to systems with long-range interactions  

NASA Astrophysics Data System (ADS)

In this paper, a mode of using the Dynamic Renormalization Group (DRG) method is suggested in order to cope with inconsistent results obtained when applying it to a continuous family of one-dimensional nonlocal models. The key observation is that the correct fixed-point dynamical system has to be identified during the analysis in order to account for all the relevant terms that are generated under renormalization. This is well established for static problems, however poorly implemented in dynamical ones. An application of this approach to a nonlocal extension of the Kardar-Parisi-Zhang equation resolves certain problems in one-dimension. Namely, obviously problematic predictions are eliminated and the existing exact analytic results are recovered.

Katzav, Eytan

2013-04-01

120

Reduced Functions, Gradients and Hessians from Fixed-Point Iterations for State Equations  

Microsoft Academic Search

In design optimization and parameter identification, the objective, or response function(s) are typically linked to the actually independent variables through equality constraints, which we will refer to as state equations. Our key assumption is that it is impossible to form and factor the corresponding constraint Jacobian, but one has instead some fixed-point algorithm for computing a feasible state, given any

Andreas Griewank; Christèle Faure

2002-01-01

121

Fixed point analysis of a scalar theory with an external field  

SciTech Connect

A momentum dependent projection of the Wegner-Hougton equation is derived for a scalar theory coupled to an external field. This formalism is useful to discuss the phase diagram of the theory. In particular we study some properties of the Gaussian fixed point. {copyright} {ital 1997} {ital The American Physical Society}

Bonanno, A. [Istituto di Astronomia, Universita di Catania, Viale Andrea Doria 6, 95125 Catania (Italy); Zappala, D. [Dipartimento di Fisica, Universita di Catania, and INFN, sezione di Catania, Corso Italia 57, 95129 Catania (Italy)

1997-09-01

122

A Common Fixed Point Theorem through Weak and SemiCompatibility in Fuzzy Metric Space  

NASA Astrophysics Data System (ADS)

In this paper, a common fixed point theorem for six self mappings has been established using the concept of semicompatibility and weak compatibility in Fuzzy metric space, which generalizes the result of Singh B.S., Jain A. and Masoodi A.A. [6

Singh, Deepak; Rathore, M. S.; Sisodia, Krishnapal Singh

2013-03-01

123

Scalar-tensor cosmologies: Fixed points of the Jordan frame scalar field  

SciTech Connect

We study the evolution of homogeneous and isotropic, flat cosmological models within the general scalar-tensor theory of gravity with arbitrary coupling function and potential. After introducing the limit of general relativity we describe the details of the phase space geometry. Using the methods of dynamical systems for the decoupled equation of the Jordan frame scalar field we find the fixed points of flows in two cases: potential domination and matter domination. We present the conditions on the mathematical form of the coupling function and potential which determine the nature of the fixed points (attractor or other). There are two types of fixed points, both are characterized by cosmological evolution mimicking general relativity, but only one of the types is compatible with the Solar System parametrized post-Newtonian (PPN) constraints. The phase space structure should also carry over to the Einstein frame as long as the transformation between the frames is regular which however is not the case for the latter (PPN compatible) fixed point.

Jaerv, Laur; Kuusk, Piret; Saal, Margus [Institute of Physics, University of Tartu, Riia 142, Tartu 51014 (Estonia); Tartu Observatory, Toravere 61602 (Estonia)

2008-10-15

124

Analyzing fixed points of intracellular regulation networks with interrelated feedback topology  

PubMed Central

Background Modeling the dynamics of intracellular regulation networks by systems of ordinary differential equations has become a standard method in systems biology, and it has been shown that the behavior of these networks is often tightly connected to the network topology. We have recently introduced the circuit-breaking algorithm, a method that uses the network topology to construct a one-dimensional circuit-characteristic of the system. It was shown that this characteristic can be used for an efficient calculation of the system’s fixed points. Results Here we extend previous work and show several connections between the circuit-characteristic and the stability of fixed points. In particular, we derive a sufficient condition on the characteristic for a fixed point to be unstable for certain graph structures and demonstrate that the characteristic does not contain the information to decide whether a fixed point is asymptotically stable. All statements are illustrated on biological network models. Conclusions Single feedback circuits and their role for complex dynamic behavior of biological networks have extensively been investigated, but a transfer of most of these concepts to more complex topologies is difficult. In this context, our algorithm is a powerful new approach for the analysis of regulation networks that goes beyond single isolated feedback circuits.

2012-01-01

125

On the Convergence of the Lagged Diffusivity Fixed Point Method in Total Variation Image Restoration  

Microsoft Academic Search

In this paper we show that the lagged diffusivity fixed point algorithm introduced by Vogel and Oman in (SIAM J. Sci. Comput., 17 (1996), pp. 227-238) to solve the problem of total variation denoising, proposed by Rudin, Osher, and Fatemi in (Phys. D, 60 (1992), pp. 259-268), is a particular instance of a class of algorithms introduced by Voss and

Tony F. Chan; Pep Mulet

1999-01-01

126

Parameterization of the three-dimensional motions of a rigid body rotating about a fixed point  

Microsoft Academic Search

An orthogonal attitude matrix is constructed for a rigid body rotating about a fixed point. This matrix specifies the transformation, in a prescribed time period, of the orthogonal basis connected with the body from its initial nonstationary state to a final programmed rotational state. Knowledge of this matrix (whose boundary derivatives correspond to boundary values of the vector of the

Iu. A. Karpachev

1986-01-01

127

Control of transient chaos in tent maps near crisis. I. Fixed point targeting  

Microsoft Academic Search

Combinatorial techniques are applied to the symbolic dynamics representing transient chaotic behavior in tent maps in order to solve the problem of Ott-Grebogi-Yorke control to the nontrivial fixed point occurring in such maps. This approach allows ``preimage overlap'' to be treated exactly. Closed forms for both the probability of control being achieved and the average number of iterations to control

D. K. Arrowsmith

2000-01-01

128

Fixed-point smoothing with a measurement process initiated a posteriori  

Microsoft Academic Search

For discrete linear stochastic systems, a fixed-point smoothing algorithm is given to obtain optimal estimates of the state of the system at timek = i(ifixed) when noisy linear measurements of the state are not available until the timek = j(j > i). An example is included to illustrate smoothing degradation as (j - i) increases.

R. Priemer

1973-01-01

129

Crustal deformation measurements in Central Japan determined by a global positioning system fixed-point network  

Microsoft Academic Search

A Global Positioning System (GPS) fixed-point network has been operating in the Kanto and Tokai districts of central Japan since April 1988 to detect crustal deformation associated with the convergence of the Eurasian. Pacific, North American, and Philippine Sea plates and to monitor the deformation cycles of frequent large interplate and intraplate earthquakes. This 10-station network established by the National

Seiichi Shimada; Yehuda Bock

1992-01-01

130

Fixed point theorems in R -trees with applications to graph theory  

Microsoft Academic Search

It is proved that a commutative family of nonexpansive mappings of a complete R-tree X into itself always has a nonempty common fixed point set if X does not contain a geodesic ray. As a consequence of this, we show that any commuting family of edge preserving mappings of a connected reflexive graph G that contains no cycles or infinite

R. Espínola; W. A. Kirk

2006-01-01

131

Three-element zoom lens with fixed distance between focal points.  

PubMed

This work deals with a theoretical analysis of zoom lenses with a fixed distance between focal points. Equations are derived for the primary (paraxial) design of the basic parameters of a three-element zoom lens. It is shown that the number of optical elements for such a lens must be larger than two. PMID:22739850

Mikš, Antonin; Novák, Ji?í; Novák, Pavel

2012-06-15

132

Development of temperature fixed points applicable to the calibration of thermometers in magnetic fields  

Microsoft Academic Search

Two temperature fixed points, (H2O and Ar) were developed to be used under magnetic fields. They serve as ideal tools to investigate the magnetic field dependence of temperature sensors. The sensors studied are Cernox™, a platinum resistance thermometer, and a thermistor. The magnetic field effect on Cernox was found to be not larger than 5 mK under 15 T at

Koichi Nara

2004-01-01

133

Quantum Corrected Drift-Diffusion Models: Solution Fixed Point Map and Finite Element Approximation  

Microsoft Academic Search

This article deals with the analysis of the functional iteration, denoted Generalized Gummel Map (GGM), proposed in (10) for the decoupled solution of the Quantum Drift-Diffusion (QDD) model. The solution of the problem is characterized as the fixed point of the GGM, which permits the establishment of a close link between the theoretical existence analysis and the implementation of a

Carlo de Falco; Joseph W. Jeromeb; Riccardo Sacco

2008-01-01

134

Comparing fixed points of the ITS90 as realized in Canada, Argentina and Brazil  

Microsoft Academic Search

A set of fixed points maintained by national metrology institutes (NMIs) for calibrating platinum resistance thermometers (PRTs) in Canada (National Research Council, NRC), Argentina (Instituto Nacional de Tecnologia Industrial, INTI) and Brazil (Instituto Nacional de Metrologia, Normalizaçãoe Qualidade Industrial, INMETRO) were compared using two methods. A set of portable cells was used in one method, and in the other a

J Ancsin; M Tischler; S G Petkovic; J F N Santiago

2001-01-01

135

Errors Analysis in GPS Precise Point Positioning: Impact of Ambiguity Fixing  

Microsoft Academic Search

GNSS geodetic positioning using the classical double-difference approach may have some limitations. For example, fixing ambiguities can be challenging for long baselines, while processing short baseline only give the relative displacement between the two stations. In this context and thanks to the continuous improvement of IGS GNSS orbit and clock products, the Precise Point Positioning (PPP) technique appears in the

F. Perosanz; F. Fund; F. Mercier; S. Loyer; H. Capdeville

2010-01-01

136

Remarks on lattice gauge theories with infrared-attractive fixed points  

SciTech Connect

Theories of interacting gauge fields and fermions can possess a running gauge coupling with an infrared-attractive fixed point (IRFP). We present a minimal description of the physics of these systems and comment on some simple expectations for results from lattice simulations done within the basin of attraction of the IRFP in these theories.

DeGrand, Thomas; Hasenfratz, Anna [Department of Physics, University of Colorado, Boulder, Colorado 80309 (United States)

2009-08-01

137

Fixed point controllers and stabilization of the cart-pole system and the rotating pendulum  

Microsoft Academic Search

We consider stabilization of nonlinear systems in a special normal form as the cascade of a nonlinear subsystem and a linear subsystem. These systems do not possess any particular triangular structure. Despite this fact, we show how a backstepping type procedure applied to these systems naturally leads to a fixed point equation in the control input. We give conditions for

Reza Olfati-Saber

1999-01-01

138

Fixed points and stability in linear neutral differential equations with variable delays  

Microsoft Academic Search

In this paper we consider the asymptotic stability of a generalized linear neutral differential equation with variable delays by using the fixed point theory. An asymptotic stability theorem with a necessary and sufficient condition is proved, which improves and generalizes some results due to Burton (2003) [3], Zhang (2005) [14], Raffoul (2004) [13], and Jin and Luo (2008) [12]. Two

Abdelouaheb Ardjouni; Ahcene Djoudi

2011-01-01

139

Bilateral Comparison of Mercury and Gallium Fixed-Point Cells Using Standard Platinum Resistance Thermometer  

NASA Astrophysics Data System (ADS)

The objective of project EURAMET 1127 (Bilateral comparison of triple point of mercury and melting point of gallium) in the field of thermometry is to compare realization of a triple point of mercury (-38.8344 °C) and melting point of gallium (29.7646 °C) between the Slovenian national laboratory MIRS/UL-FE/LMK and the Croatian national laboratory HMI/FSB-LPM using a long-stem 25 ? standard platinum resistance thermometer (SPRT). MIRS/UL/FE-LMK participated in a number of intercomparisons on the level of EURAMET. On the other hand, the HMI/LPM-FSB laboratory recently acquired new fixed-point cells which had to be evaluated in the process of intercomparisons. A quartz-sheathed SPRT has been selected and calibrated at HMI/LPM-FSB at the triple point of mercury, the melting point of gallium, and the water triple point. A second set of measurements was made at MIRS/UL/FE-LMK. After its return, the SPRT was again recalibrated at HMI/LPM-FSB. In the comparison, the W value of the SPRT has been used. Results of the bilateral intercomparison confirmed that the new gallium cell of the HMI/LPM-FSB has a value that is within uncertainty limits of both laboratories that participated in the exercise, while the mercury cell experienced problems. After further research, a small leakage in the mercury fixed-point cell has been found.

Bojkovski, J.; Veliki, T.; Zvizdi?, D.; Drnovšek, J.

2011-08-01

140

Searching for fixed point combinators by using automated theorem proving: A preliminary report  

SciTech Connect

In this report, we establish that the use of an automated theorem- proving program to study deep questions from mathematics and logic is indeed an excellent move. Among such problems, we focus mainly on that concerning the construction of fixed point combinators---a problem considered by logicians to be significant and difficult to solve, and often computationally intensive and arduous. To be a fixed point combinator, THETA must satisfy the equation THETAx = x(THETAx) for all combinators x. The specific questions on which we focus most heavily ask, for each chosen set of combinators, whether a fixed point combinator can be constructed from the members of that set. For answering questions of this type, we present a new, sound, and efficient method, called the kernel method, which can be applied quite easily by hand and very easily by an automated theorem-proving program. For the application of the kernel method by a theorem-proving program, we illustrate the vital role that is played by both paramodulation and demodulation---two of the powerful features frequently offered by an automated theorem-proving program for treating equality as if it is ''understood.'' We also state a conjecture that, if proved, establishes the completeness of the kernel method. From what we can ascertain, this method---which relies on the introduced concepts of kernel and superkernel---offers the first systematic approach for searching for fixed point combinators. We successfully apply the new kernel method to various sets of combinators and, for the set consisting of the combinators B and W, construct an infinite set of fixed point combinators such that no two of the combinators are equal even in the presence of extensionality---a law that asserts that two combinators are equal if they behave the same. 18 refs.

Wos, L.; McCune, W.

1988-09-01

141

Many-body localization in one dimension as a dynamical renormalization group fixed point.  

PubMed

We formulate a dynamical real space renormalization group (RG) approach to describe the time evolution of a random spin-1/2 chain, or interacting fermions, initialized in a state with fixed particle positions. Within this approach we identify a many-body localized state of the chain as a dynamical infinite randomness fixed point. Near this fixed point our method becomes asymptotically exact, allowing analytic calculation of time dependent quantities. In particular, we explain the striking universal features in the growth of the entanglement seen in recent numerical simulations: unbounded logarithmic growth delayed by a time inversely proportional to the interaction strength. This is in striking contrast to the much slower entropy growth as loglogt found for noninteracting fermions with bond disorder. Nonetheless, even the interacting system does not thermalize in the long time limit. We attribute this to an infinite set of approximate integrals of motion revealed in the course of the RG flow, which become asymptotically exact conservation laws at the fixed point. Hence we identify the many-body localized state with an emergent generalized Gibbs ensemble. PMID:23432299

Vosk, Ronen; Altman, Ehud

2013-02-07

142

Indirect Determination of the Thermodynamic Temperature of a Gold Fixed-Point Cell  

NASA Astrophysics Data System (ADS)

Since the value T 90(Au) was fixed on the ITS-90, some determinations of the thermodynamic temperature of the gold point have been performed which form, with other renormalized results of previous measurements by radiation thermometry, the basis for the current best estimates of ( T - T 90)Au = 39.9 mK as elaborated by the CCT-WG4. Such a value, even if consistent with the behavior of T - T 90 differences at lower temperatures, is quite influenced by the low values of T Au as determined with few radiometric measurements. At INRIM, an independent indirect determination of the thermodynamic temperature of gold was performed by means of a radiation thermometry approach. A fixed-point technique was used to realize approximated thermodynamic scales from the Zn point up to the Cu point. A Si-based standard radiation thermometer working at 900 nm and 950 nm was used. The low uncertainty presently associated to the thermodynamic temperature of fixed points and the accuracy of INRIM realizations, allowed scales with an uncertainty lower than 0.03 K in terms of the thermodynamic temperature to be realized. A fixed-point cell filled with gold, 99.999 % in purity, was measured, and its freezing temperature was determined by both interpolation and extrapolation. An average T Au = 1337.395 K was found with a combined standard uncertainty of 23 mK. Such a value is 25 mK higher than the presently available value as derived by the CCT-WG4 value of ( T - T 90)Au = 39.9 mK.

Battuello, M.; Girard, F.; Florio, M.

2010-09-01

143

Bilateral ITS-90 comparison at WC-C peritectic fixed point between NIM and NPL  

NASA Astrophysics Data System (ADS)

The WC-C peritectic fixed point, nominal melting and freezing temperature 2747 °C, shows extremely good metrological potential. Elsewhere, we published a prototype scale comparison of the ITS-90 between NPL, NIM and CEM, using high temperature eutectic fixed points (HTFPs) of Co-C (1324 °C), Pt-C (1738 °C), and Re-C (2474 °C). In this paper we present the further results of the bilateral comparison of the ITS-90 at an even higher temperature, 2747 °C, between NIM and NPL using WC-C peritectic fixed points. A NIM single zone high temperature furnace, model Chino IR-80, was modified to extend its temperature to 2800 °C. Then, an NPL researcher, on secondment to NIM, filled two WC-C cells in the modified furnace in a vertical position. The two WC-C cells were then realized in the same furnace, in an horizontal position. Their melting temperatures, defined by the inflection point of the melting curves, were measured by a linear pyrometer, model NIM-PSP. NIM's ITS-90 scale was assigned to the two cells, which were then transported to NPL. The realization of NPL's ITS-90 was then assigned to the two cells by using a model HT9500 Thermogauge furnace to realize the fixed points and a linear pyrometer, model LP3, to determine their temperature. The difference from the mean value of the NIM and NPL ITS-90 values for the WC-C points was derived. This allowed us to compare ITS-90 as realized by the two institutes and to determine the uncertainty in the scale comparison.

Dong, W.; Lowe, D. H.; Lu, X.; Machin, G.; Yuan, Z.; Wang, T.; Bloembergen, P.; Xiao, C.

2013-09-01

144

Experimental Investigation of the Cr3C2 C Peritectic Fixed Point  

NASA Astrophysics Data System (ADS)

The Cr3C2 C (1,826°C) peritectic point was investigated for its performance as a high-temperature fixed point. Dependence on the impurity content was observed, although it was less severe for the higher of the two equilibrium temperatures obtained with the same cell, the Cr3C2 C peritectic point, than for the lower, the Cr7C3 Cr3C2 eutectic point. Thermal history had an effect on the melting plateau duration, but not on the point-of-inflection temperature nor on the melting range. The melting rate had no apparent effect. The repeatability evaluated as the standard deviation of the repeated melting plateaux within a day was 20 mK for the Cr3C2 C peritectic point, while for the Cr7C3 Cr3C2 eutectic point, this was 210 mK. For both the Cr3C2 C peritectic and the Cr7C3 Cr3C2 eutectic, the freezing plateaux often showed deep supercools, which made them unsuitable for use. The observed good repeatability shows the peritectic-point performance to be comparable to the best MC-eutectic high-temperature fixed points investigated so far. The insensitivity to thermal history constitutes an important and practical advantage. The low price of chromium is a clear benefit as compared to Pt C (1,738°C) or Ru C (1,953°C) eutectic points, the M C eutectic points in this temperature range.

Zheng, W.; Yamada, Y.; Wang, Y.

2008-06-01

145

``MULTICELLS'': A European Project on Cryogenic Temperature Fixed Points in Sealed Cells  

NASA Astrophysics Data System (ADS)

In January 2000 a European Project called ``MULTICELLS'' started, in the field of the realisation of temperature standard fixed points in the range (2.18 to 216.6) K, ending in April 2003. Two lines of cell design were developed for both modular multi-component cells (IMGC and INM down to 13.8 K) and 4He lambda-point cells (IMGC and PTB). The cells were tested mainly by INTiBS, NMi, NPL, and PTB. Studies were performed on the thermal design and to improve the knowledge of the underlying physical chemistry, with the goal of reducing the overall uncertainty budget to less than 0.1 mK. This involved also the comparison of the new modular multi-component cells, which are made of several elements-each realising one different fixed point, e.g., e-H2, Ne, O2, and Ar, but also D2, N2 and CO2- mounted on a common frame where the thermometers are fitted, with the previous-generation cells. The new cells represent a substantial improvement in the state-of-the-art of the realisation of these fixed points and of their use for the realisation of the ITS-90 and for thermometric checkpoints. A self-contained cryogenic-free computer-run cryostat is under development as the final stage of the Project for measuring the modular cells and for thermometer intercomparison.

Pavese, F.; Fellmuth, B.; Head, D.; Hermier, Y.; Peruzzi, A.; Szmyrka Grzebyk, A.; Zanin, L.

2003-09-01

146

Experimental and Numerical Investigation of the Temperature Field of a Fixed-Point Cavity  

NASA Astrophysics Data System (ADS)

The temperature field non-uniformity of a blackbody cavity is one of the components of uncertainty of fixed-point realization. Here a study of the design and opportunities of the temperature furnace used in VNIIM is described. The dependence of the uniformity of a temperature field on various factors is shown by results of numerical calculations of a temperature field of VNIIM's copper and gold fixed-point cells, realized with the software packages Elcut 5.3 and Ansys 11.0. A thermophysical model of the phase transition considered as steady state with convection and radiation heat exchange to an environment is applied. The basic focus is made on calculation of the radiation heat exchange between crucible elements and the environment and a furnace cavity, as a dominating component of the heat transfer. Results using analytically and numerically calculated angular factors of radiation of heat exchange are discussed. The data obtained in measurements of a temperature field of a cavity fixed point during phase transitions of copper and gold by a spectrocomparator with high sensitivity, are also shown here. Both theoretical calculation and experiment were realized at various distributions of temperature along an external surface of a crucible. Good agreement of results between steady-state calculation of a temperature field and the measured data with the best entry conditions is observed. The average value of non-uniformity of a temperature field along a cavity for points of phase transition of copper and gold for an 88 mm long graphite crucible with a 54 mm deep, 8 mm diameter cavity was 40 mK, and the temperature drop across the graphite wall was 20 mK. In this paper the reasons for occurrence of large gradients inside a fixed-point cavity during the phase transition, received during some experimental research, are also discussed.

Fuksov, V. M.; Pohodun, A. I.; Matveyev, M. S.

2011-01-01

147

Cryostat for Fixed-Point Calibration of Capsule-Type SPRTs  

NASA Astrophysics Data System (ADS)

A cryostat for fixed-point calibration of capsule-type SPRTs (standard platinum resistance thermometers) was developed. Using this system, cryogenic fixed points defined on the International Temperature Scale of 1990 (ITS-90) were realized. The cryogenic cells were argon, oxygen, neon, and two equilibrium-hydrogen (e-H2) cells, made by INRiM, Italy. The uncertainty of the realization of each fixed point was estimated to range from 0.53 mK to 0.43 mK ( k = 2). The realizations of the triple point of e-H2 using two sealed cells coincided within 0.1 mK. Therefore, we are able to calibrate capsule-type SPRTs down to 24.5561 K within an uncertainty of 1 mK ( k = 2) by this system. A closed-cycle helium gas refrigerator was used for the cryostat. Each sealed cell was designed so that it could accommodate three sealed cells in the thermometer wells made within the cell. Therefore, the cryostat was designed to accommodate only one sealed cell at a time. The base temperature of this liquid-free cryostat, when one sealed cell and three capsule-type SPRTs were attached for calibration, was ~17 K. For the realization of the triple point of e-H2, we used liquid helium for additional cooling. Adiabatic melting of the triple point was realized by controlling the inner-most radiation shield at a temperature very close to that of the triple point, and by applying a heat pulse by a heater directly wound to the cell. The amount of the heater power and the waiting time for the thermal equilibrium after each heat pulse were chosen in a way that the adiabatic melting could be finished within ~6 h for each cell. The triple point of each cryogenic fixed point was deduced from the equilibrium temperatures between the heat pulses and subsequent extrapolation to the liquidus point. For the oxygen cell, temperatures of two solid-solid transitions ( ?- ? and ?- ? transitions) were also measured, and the results were consistent with values reported in the literature within the designated uncertainty.

Yang, I.; Song, C. H.; Kim, Y.-G.; Gam, K. S.

2011-12-01

148

Rigorous high-precision enclosures of fixed points and their invariant manifolds  

NASA Astrophysics Data System (ADS)

The well established concept of Taylor Models is introduced, which offer highly accurate C0 enclosures of functional dependencies, combining high-order polynomial approximation of functions and rigorous estimates of the truncation error, performed using verified arithmetic. The focus of this work is on the application of Taylor Models in algorithms for strongly non-linear dynamical systems. A method is proposed to extend the existing implementation of Taylor Models in COSY INFINITY from double precision coefficients to arbitrary precision coefficients. Great care is taken to maintain the highest efficiency possible by adaptively adjusting the precision of higher order coefficients in the polynomial expansion. High precision operations are based on clever combinations of elementary floating point operations yielding exact values for round-off errors. An experimental high precision interval data type is developed and implemented. Algorithms for the verified computation of intrinsic functions based on the High Precision Interval datatype are developed and described in detail. The application of these operations in the implementation of High Precision Taylor Models is discussed. An application of Taylor Model methods to the verification of fixed points is presented by verifying the existence of a period 15 fixed point in a near standard Henon map. Verification is performed using different verified methods such as double precision Taylor Models, High Precision intervals and High Precision Taylor Models. Results and performance of each method are compared. An automated rigorous fixed point finder is implemented, allowing the fully automated search for all fixed points of a function within a given domain. It returns a list of verified enclosures of each fixed point, optionally verifying uniqueness within these enclosures. An application of the fixed point finder to the rigorous analysis of beam transfer maps in accelerator physics is presented. Previous work done by Johannes Grote is extended to compute very accurate polynomial approximations to invariant manifolds of discrete maps of arbitrary dimension around hyperbolic fixed points. The algorithm presented allows for automatic removal of resonances occurring during construction. A method for the rigorous enclosure of invariant manifolds of continuous systems is introduced. Using methods developed for discrete maps, polynomial approximations of invariant manifolds of hyperbolic fixed points of ODEs are obtained. These approximations are outfit with a sharp error bound which is verified to rigorously contain the manifolds. While we focus on the three dimensional case, verification in higher dimensions is possible using similar techniques. Integrating the resulting enclosures using the verified COSY VI integrator, the initial manifold enclosures are expanded to yield sharp enclosures of large parts of the stable and unstable manifolds. To demonstrate the effectiveness of this method, we construct enclosures of the invariant manifolds of the Lorenz system and show pictures of the resulting manifold enclosures. To the best of our knowledge, these enclosures are the largest verified enclosures of manifolds in the Lorenz system in existence.

Wittig, Alexander N.

149

Comparison of Co-C eutectic fixed-point cells between VNIIM and VNIIOFI  

NASA Astrophysics Data System (ADS)

Two national metrological institutes of the Russian Federation, VNIIM and VNIIOFI, take part in the international research plan of CCT WG5 for investigation of high-temperature fixed points (HTFP). In the framework of this CCT-WG5 HTFP Research Plan the both institutes have designed and built independently cobalt-carbon (Co-C) eutectic radiation cells. The comparison of the Co-C cells developed by the institutes was carried out with the aim of determination of a difference in the melting temperature due to difference in the constructional characteristics of the cells. The radiance-mode radiation thermometers with central wavelength nearby 650 nm were used for the fixed-point melting temperature measurements. The article presents preliminary results of the comparison, which shows agreement between melting temperature of the compared cells within 20 mK. The details of the comparison are reported.

Sild, Y.; Khlevnoy, B.; Matveyev, M.; Grigorieva, I. A.; Fuksov, V. M.

2013-09-01

150

Symmetries and fixed point stability of stochastic differential equations modeling self-organized criticality  

NASA Astrophysics Data System (ADS)

A stochastic nonlinear partial differential equation is constructed for two different models exhibiting self-organized criticality: the Bak-Tang-Wiesenfeld (BTW) sandpile model [Phys. Rev. Lett. 59, 381 (1987); Phys. Rev. A 38, 364 (1988)] and the Zhang model [Phys. Rev. Lett. 63, 470 (1989)]. The dynamic renormalization group (DRG) enables one to compute the critical exponents. However, the nontrivial stable fixed point of the DRG transformation is unreachable for the original parameters of the models. We introduce an alternative regularization of the step function involved in the threshold condition, which breaks the symmetry of the BTW model. Although the symmetry properties of the two models are different, it is shown that they both belong to the same universality class. In this case the DRG procedure leads to a symmetric behavior for both models, restoring the broken symmetry, and makes accessible the nontrivial fixed point. This technique could also be applied to other problems with threshold dynamics.

Corral, Álvaro; Díaz-Guilera, Albert

1997-03-01

151

Fixed-point vs. floating-point arithmetic comparison for adaptive optics real-time control computation  

NASA Astrophysics Data System (ADS)

Most computers in the past have been equipped with floating point processing capabilities, allowing an easy and brute-force solution for the machine computation errors, not requiring any specific tailoring of the computation in nearly hundred percent of situations. However, the computation needed for the adaptive optics real-time control in 30-50 meter telescopes is big enough to cause trouble to conventional von-Neumann processors, even if Moore's Law is valid for the next years. Field Programmable Gate Array (FPGAs) have been proposed as a viable alternative to cope with such computation needs[1,2], but--at least today's chips--will require fixed-point arithmetic to be used instead. It is then important to evaluate up to what point the accuracy and stability of the control system will be affected by this limitation. This paper presents the simulation and laboratory results of the comparison between both arithmetics, specifically evaluated in an adaptive optics system. The real-time controller has been modeled as black box having as input the wavefront sensor camera digital output data, providing a digital output to the actuators of the deformable mirror, and with the task of internally computing all outputs from the inputs. MATLAB fixed-point library has been used to evaluate the effect of different precision lengths (5-10 fractional bits) in the computation of the Shack-Hartmann subaperture centroid, in comparison with the reference 64-bit floating-point arithmetic and with the noise floor of the real system, concluding that the effect of the limited precision can be overcome by adequately selecting the number of fractional bits used in the representation, and tailoring that number with the needs at every step of the algorithm.

Martín-Hernando, Yolanda; Rodríguez-Ramos, Luis F.; Garcia-Talavera, Marcos R.

2008-07-01

152

Back-reaction of the vacuum and the renormalization group flow from the conformal fixed point  

Microsoft Academic Search

We consider the GUT-like model with two scalar fields which has infinitesimal deviation from the conformal invariant fixed point in the high-energy region. In this case the dominant quantum effect is the conformal trace anomaly and the interaction between the anomaly-generated propagating conformal factor of the metric and the usual dimensional scalar field. This interaction leads to the renormalization group

Guido Cognola; I. L. Shapiro

1998-01-01

153

Comparison of nickel carbon and iron carbon eutectic fixed point cells for the calibration of thermocouples  

Microsoft Academic Search

Three nickel-carbon (Ni-C) and three iron-carbon (Fe-C) eutectic fixed points cells of a new design, meeting the requirements for reliable applications and being suitable for the calibration of thermocouples, were constructed at PTB and Inmetro. Their melting temperatures were compared by using the high-temperature furnace of PTB (HTF-R) and two platinum\\/palladium (Pt\\/Pd) thermocouples. The measured emfs of the Ni-C eutectic

F. Edler; A. C. Baratto

2006-01-01

154

Chaos in a restricted problem of rotation of a rigid body with a fixed point  

Microsoft Academic Search

In this paper, we consider the transition to chaos in the phase portrait of a restricted problem of rotation of a rigid body\\u000a with a fixed point. Two interrelated mechanisms responsible for chaotization are indicated: (1) the growth of the homoclinic\\u000a structure and (2) the development of cascades of period doubling bifurcations. On the zero level of the area integral,

A. V. Borisov; A. A. Kilin; I. S. Mamaev

2008-01-01

155

Paraxial analysis of four-component zoom lens with fixed distance between focal points.  

PubMed

Zoom lenses with a fixed distance between focal points are analyzed. Formulas are derived for the primary design of basic parameters of a four-component zoom lens. It is also demonstrated that a three-component zoom lens can be analyzed using derived formulas. Zoom lenses with such a design can be used in a 4-f system with variable magnification or as a part of a double side telecentric lenses with variable magnification. PMID:22858966

Miks, Antonin; Novak, Jiri

2012-07-20

156

Time-domain fast fixed-point algorithms for convolutive ICA  

Microsoft Academic Search

This letter presents new blind separation methods for moving average (MA) convolutive mixtures of independent MA processes. They consist of time-domain extensions of the FastICA algorithms developed by Hyvarinen and Oja for instantaneous mixtures. They perform a convolutive sphering in order to use parameter-free fast fixed-point algorithms associated with kurtotic or negentropic non-Gaussianity criteria for estimating the source innovation processes.

Johan Thomas; Yannick Deville; Shahram Hosseini

2006-01-01

157

Experimental investigation of Cr3C2-C peritectic fixed point  

Microsoft Academic Search

High-temperature fixed points of metal-carbide carbon peritectics have transition temperatures close to some of the metal (carbide)-carbon eutectics, and act similar to them in the sense that they can be used at high temperature without being contaminated by the graphite crucibles. The performance seems similar, or maybe even better, in terms of repeatability and plateau shape. In this paper, we

Yoshiro Yamada; Yunfen Wang; Naohiko Sasajima

2007-01-01

158

Single current sensor operation with fixed sampling points based on TSPWM  

Microsoft Academic Search

The single current sensor operation (SCSO) is favorable for cost reduction and fault-tolerance purposes in three-phase inverter-driven systems. This paper addresses a SCSO method based on tri-state pulse-width modulation technique (TSPWM). It enables fixed sampling points with minimal hardware and software requirements. Simultaneous three phase currents can be easily computed due to symmetrical sampling. No change to TSPWM is needed

Xiaomeng Cheng; Haifeng Lu; Wenlong Qu

2010-01-01

159

Some notes on the paper “Cone metric spaces and fixed point theorems of contractive mappings”  

Microsoft Academic Search

Huang and Zhang reviewed cone metric spaces in 2007 [Huang Long-Guang, Zhang Xian, Cone metric spaces and fixed point theorems of contractive mappings, J. Math. Anal. Appl. 332 (2007) 1468–1476]. We shall prove that there are no normal cones with normal constant M1 and for each k>1 there are cones with normal constant M>k. Also, by providing non-normal cones and

Sh. Rezapour; R. Hamlbarani

2008-01-01

160

Polynomial fixed-point algorithm applied to the electromagnetic analysis of one-dimensional continuous structures  

Microsoft Academic Search

We develop a general procedure that allows the determination of the spectral transmittance and reflectance at normal incidence for arbitrary one-dimensional continuous materials as well as the analysis of the time-domain propagation of pulses through them. This procedure consists of a generalization of Fresnel equations, and it is supported by an iterative algorithm also developed here: the polynomial fixed-point algorithm

M. Perez-Molina; Luis Carretero-Lopez

2007-01-01

161

A New Method for the Quantification and Correction of Thermal Effects on the Realization of Fixed Points  

NASA Astrophysics Data System (ADS)

The temperature and flatness (shape) of a fixed-point plateau depend on both the amount and nature of specific impurities and on thermal effects that are influenced by the fixed-point cell design and furnace properties. A better understanding and experimental proof of the influence of specific impurities on fixed-point realizations require the separation of impurity influences from thermal effects. In this paper the influence of heat exchange between the thermometer and furnace is quantified via a method based on changing the furnace temperature during the fixed-point measurement. It will be shown that the corresponding correction of this thermal effect has a dominant influence on the plateau shape compared to the influence of impurities. This leads to an explanation for why the maximum of an induced freeze is the most reproducible temperature. A secondary outcome is an explanation of why natural freezes have less flat plateaux compared to induced freezes, resulting in fixed-point temperatures that are too low. Furthermore, the suggested procedure is the basis of the direct and quantitative comparison of fixed-point cells and the detection of weak points within a specific design. It allows optimization of fixed-point cells and furnaces, and helps to deepen the common understanding of the phase transition in fixed-point cells.

Fahr, M.; Rudtsch, S.

2008-02-01

162

Back-reaction of the vacuum and the renormalization group flow from the conformal fixed point  

NASA Astrophysics Data System (ADS)

We consider the GUT-like model with two scalar fields which has infinitesimal deviation from the conformal invariant fixed point in the high-energy region. In this case the dominant quantum effect is the conformal trace anomaly and the interaction between the anomaly-generated propagating conformal factor of the metric and the usual dimensional scalar field. This interaction leads to the renormalization group flow from the conformal point. In the supersymmetric conformal invariant model such an effect produces a very weak violation of sypersymmetry at lower energies.

Cognola, G.; Shapiro, I. L.

1998-11-01

163

A study about the fitting curves for the calibration of the Pt/Rh family thermocouples in fixed points  

NASA Astrophysics Data System (ADS)

The aim of this paper is to study the suitability of the common procedures used to estimate the calibration fitting curves of noble metal thermocouples, namely from the Pt/Rh family, in fixed points. The objective is to find out the best combination and the minimum number of fixed points that allows obtaining a reasonable interpolation uncertainty.

del Campo, D.; García, C.

2013-09-01

164

Common fixed point theorems of Gregus type for weakly compatible mappings satisfying contractive conditions of integral type  

Microsoft Academic Search

We prove a common fixed point theorem of Gregus type for four mappings satisfying a contractive condition of integral type in metric spaces using the concept of weak compatibility which generalizes Theorem 2 of [A. Djoudi, L. Nisse, Gregus type fixed points for weakly compatible mappings, Bull. Belg. Math. Soc. 10 (2003) 369–378] and other papers. We prove also common

A. Djoudi; A. Aliouche

2007-01-01

165

Construction of high-temperature fixed-point cells for thermodynamic temperature assignment  

NASA Astrophysics Data System (ADS)

A multi-partner project is currently being conducted within Working Group 5 (Radiation thermometry) of the CIPM Consultative Committee for Thermometry (CCT), which aims at assigning thermodynamic temperatures to a selected set of high-temperature fixed-points (HTFPs) based on metal-carbon eutectics. A work package of this project (WP2) consists in producing sets of HTFP cells to serve the final phase of the project, assignment of definitive thermodynamic temperatures (WP5). The four fixed-point types are the metal-carbon eutectic points, Re-C (2474 °C), Pt-C (1739 °C), and Co-C (1324 °C), and the Cu point (1084.62 °C). The first phase of the WP2 work treats the construction of HTFP cells, which were carried out by eight National Metrology Institutes (NMIs). The cells were constructed in accordance to instructions laid out in the WP protocol, based on years of experience of WG5 member NMIs. Cells constructed in this way should, in principle, have the required performance in terms of the realized temperature, reproducibility, and long term stability. The constructed cells were then evaluated for their performance in the second phase of the WP. The WP aims at identifying at least four cells of each of the four fixed-point types to be supplied to WP5 of the CCT-WG5 research plan for final thermodynamic temperature assignment. This paper describes the first phase of the WP2. Details of the cell construction conditions and procedures are presented.

Yamada, Y.; Anhalt, K.; Battuello, M.; Bloembergen, P.; Khlevnoy, B.; Machin, G.; Matveyev, M.; Sadli, M.; Wang, T.

2013-09-01

166

Common fixed point theorems of Gregus type for weakly compatible mappings satisfying contractive conditions of integral type  

NASA Astrophysics Data System (ADS)

We prove a common fixed point theorem of Gregus type for four mappings satisfying a contractive condition of integral type in metric spaces using the concept of weak compatibility which generalizes Theorem 2 of [A. Djoudi, L. Nisse, Gregus type fixed points for weakly compatible mappings, Bull. Belg. Math. Soc. 10 (2003) 369-378] and other papers. We prove also common fixed point theorems of Gregus type using a strict contractive condition of integral type, a property (E.A) and a common property (E.A) introduced by [M. Aamri, D. El Moutawakil, Some new common fixed point theorems under strict contractive conditions, J. Math. Anal. Appl. 270 (2002) 181-188] and [W. Liu, J. Wu, Z. Li, Common fixed points of single-valued and multi-valued maps, Int. J. Math. Math. Sci. 19 (2005) 3045-3055], respectively.

Djoudi, A.; Aliouche, A.

2007-05-01

167

SHORT COMMUNICATION: Metal carbide-carbon peritectic systems as high-temperature fixed points in thermometry  

NASA Astrophysics Data System (ADS)

WC-C, Cr3C2-C and Mn7C3-C peritectic systems were investigated for their potential of serving as high-temperature reference points in thermometry. Mixtures of high-purity graphite powder with W, Cr and Mn powder of 99.99%, 99.9% and 99.95% purity by mass, respectively, were placed in graphite blackbody crucibles and melting/freezing plateaus were observed by means of a radiation thermometer. The observed melting temperatures were 2749 °C (WC-C), 1826 °C (Cr3C2-C) and 1331 °C (Mn7C3-C), with a repeatability—in each case—of 0.02 K. The melting range for WC-C and Cr3C2-C peritectics was roughly 0.1 K. WC-C showed a flat freezing plateau that agreed with the melting plateau within the repeatability. The three fixed points are possible candidates, like the metal (carbide)-carbon eutectic fixed points, in the realization of an improved high-temperature scale above the copper point.

Yamada, Y.; Wang, Y.; Sasajima, N.

2006-10-01

168

Presentation functions, fixed points, and a theory of scaling function dynamics  

SciTech Connect

Presentation functions provide the time-ordered points of the forward dynamics of a system as successive inverse images. They generally determine objects constructed on trees, regular or otherwise, and immediately determine a functional form of the transfer matrix of these systems. Presentation functions for regular binary trees determine the associated forward dynamics to be that of a period doubling fixed point. They are generally parametrized by the trajectory scaling function of the dynamics in a natural way. The requirement that the forward dynamics be smooth with a critical point determines a complete set of equations whose solution is the scaling function. These equations are compatible with a dynamics in the space of scalings which is conjectured, with numerical and intuitive support, to possess its solution as a unique, globally attracting fixed point. It is argued that such dynamics is to be sought as a program for the solution of chaotic dynamics. In the course of the exposition new information pertaining to universal mode locking is presented.

Feigenbaum, M.J.

1988-08-01

169

The ? - ? transition of oxygen as a secondary fixed point of the ITS-90  

NASA Astrophysics Data System (ADS)

Oxygen is a substance in which two solid-to-solid phase transitions occur in the low temperature range, in addition to the triple point at ~54 K: the ?-? solid-to-solid transition at ~43.8 K and the ?-? transition at ~23.8 K. The triple point of oxygen is a fixed point of the International Temperature Scale of 1990. The solid-to-solid transitions are included in the list of BIPM - CCT secondary fixed points. In the paper, the thermal properties at the ?-?. transition are presented. The transition is of first order, associated with large structural changes. Measurements were carried out at INTiBS and at INRIM using oxygen sealed cells manufactured and filled at INRIM. Two methods - continuous and pulse heating - were used to determine the oxygen temperature across the transition. A flat plateau was observed for the part of the transition dominated by the ? phase, while, where the ? phase becomes predominant, the transition temperature starts to increase substantially along with the sample time constant.

Szmyrka-Grzebyk, A.; Kowal, A.; Lipi?ski, L.; Manuszkiewicz, H.; Steur, P. P. M.; Pavese, F.

2013-09-01

170

Fixed and unfixed points: Infrared limits in optimized QCD perturbation theory  

NASA Astrophysics Data System (ADS)

Perturbative QCD, when optimized by the principle of minimal sensitivity at fourth order, yields finite results for R(Q) down to Q=0. For two massless flavors (nf=2) this occurs because the couplant "freezes" at a fixed-point of the optimized ? function. However, for larger nf's, between 6.7 and 15.2, the infrared limit arises by a novel mechanism in which the evolution of the optimized ? function with energy Q is crucial. The evolving ? function develops a minimum that, as Q?0, just touches the axis at ap (the "pinch point"), while the infrared limit of the optimized couplant is at a larger value, a? (the "unfixed point"). This phenomenon results in R approaching its infrared limit not as a power law, but as R?R?-const/|. Implications for the phase structure of QCD as a function of nf are briefly considered.

Stevenson, P. M.

2013-10-01

171

Cryogenic Temperature Sealed Fixed Points: a New-Generation of Modular Cells at IMGC  

NASA Astrophysics Data System (ADS)

Mainly in the frame of the European Project MULTICELLS, IMGC developed a new generation of sealed temperature fixed-point cells (M-cells), based on the principle of modular elements, each containing one substance, several of which can be mounted in a copper frame of reduced dimensions where thermometers are fitted. The device being modular, the user can select up to six fixed points to be mounted each time in the device. The paper describes the design of the devices and reports on three years of testing on e-H2, Ne, O2 and Ar elements and on investigations not only at IMGC but also at INTiBS, NMi, NPL and PTB. The results obtained with the new devices are better than those obtained with the previous single-substance IMGC cells. These studies mainly concerned the effect of the geometry of the elements, which are now much smaller in size than the previous IMGC cells, on the thermal behaviour, in order to optimise the thermal response time and minimise the thermal resistance between the solid-liquid interface of the substance and the thermometers. For e-H2, the new elements also allowed investigation of the effect of the isotopic composition on the triple-point temperature.

Pavese, F.; Ferri, D.; Peroni, I.; Pugliese, A.; Steur, P. P. M.; Fellmuth, B.; Head, D.; Lipinski, L.; Peruzzi, A.; Szmyrka Grzebyk, A.; Wolber, L.

2003-09-01

172

Non-Fermi-liquid fixed point in a Wilsonian theory of quantum critical metals  

NASA Astrophysics Data System (ADS)

We study the problem of disorder-free metals near a continuous quantum critical point. We depart from the standard paradigm [Hertz, Phys. Rev. B0556-280510.1103/PhysRevB.14.1165 14, 1165 (1976) and Millis, Phys. Rev. BPRBMDO0163-182910.1103/PhysRevB.48.7183 48, 7183 (1993)] and treat both fermions and bosons (i.e., order parameter fields) on equal footing. We construct a Wilsonian effective field theory that integrates out only high-energy boson and fermion modes. Below the upper critical dimension of the theory (d=3 spatial dimensions), we find new fixed points in which the bosons are described by the Wilson-Fisher fixed point and are coupled to a non-Fermi-liquid metal. We describe subtleties with the renormalization group flow of four-Fermi interactions, which can be surmounted in a controlled large-N limit. In this limit, we find that the theory has no superconducting instability.

Fitzpatrick, A. Liam; Kachru, Shamit; Kaplan, Jared; Raghu, S.

2013-09-01

173

Nonthermal fixed points: effective weak coupling for strongly correlated systems far from equilibrium.  

PubMed

Strongly correlated systems far from equilibrium can exhibit scaling solutions with a dynamically generated weak coupling. We show this by investigating isolated systems described by relativistic quantum field theories for initial conditions leading to nonequilibrium instabilities, such as parametric resonance or spinodal decomposition. The nonthermal fixed points prevent fast thermalization if classical-statistical fluctuations dominate over quantum fluctuations. We comment on the possible significance of these results for the heating of the early Universe after inflation and the question of fast thermalization in heavy-ion collision experiments. PMID:18764319

Berges, Jürgen; Rothkopf, Alexander; Schmidt, Jonas

2008-07-25

174

Uncertainty due to non-linearity in radiation thermometers calibrated by multiple fixed points  

NASA Astrophysics Data System (ADS)

A new method to estimate the uncertainty due to non-linearity is described on the n = 3 scheme basis. The expression of uncertainty is mathematically derived applying the random walk method. The expression is simple and requires only the temperatures of the fixed points and a relative uncertainty value for each flux-doubling derived from the non-linearity measurement. We also present an example of the method, in which the uncertainty of temperature measurement by a radiation thermometer is calculated on the basis of non-linearity measurement.

Yamaguchi, Y.; Yamada, Y.

2013-09-01

175

A non-Gaussian renormalization group fixed point for hierarchical scalar lattice field theories  

NASA Astrophysics Data System (ADS)

A rigorous method is developed to handle the “large field problems” in the Wilson-Kadanoff renormalization group approach to critical lattice systems of unbounded spins. We use this method to study in a hierarchical approximation the non-Gaussian renormalization group fixed point which governs the infrared behaviour of critical lattice field theories in three dimensions. The method is an improvement of the analyticity techniques of Gawedzki and Kupiainen: using Borel summation techniques we are able to incorporate the “large field region” into the “perturbative region” so that the theory is completely described in terms of convergent expansions.

Koch, Hans; Wittwer, Peter

1986-09-01

176

Development of a new radiometer for the thermodynamic measurement of high temperature fixed points  

NASA Astrophysics Data System (ADS)

The National Physical Laboratory (NPL) has developed a new radiometer to measure the thermodynamic melting point temperatures of high temperature fixed points with ultra-low uncertainties. In comparison with the NPL's Absolute Radiation Thermometer (ART), the "THermodynamic Optical Radiometer" (THOR) is more portable and compact, with a much lower size-of-source effect and improved performance in other parameters such as temperature sensitivity. It has been designed for calibration as a whole instrument via the radiance method, removing the need to calibrate the individual subcomponents, as required by ART, and thereby reducing uncertainties. In addition, the calibration approach has been improved through a new integrating sphere that has been designed to have greater uniformity.

Dury, M. R.; Goodman, T. M.; Lowe, D. H.; Machin, G.; Woolliams, E. R.

2013-09-01

177

Investigation of TiC C Eutectic and WC C Peritectic High-Temperature Fixed Points  

NASA Astrophysics Data System (ADS)

TiC C eutectic (2,761°C) and WC C peritectic (2,749°C) fixed points were investigated to compare their potential as high-temperature thermometric reference points. Two TiC C and three WC C fixed-point cells were constructed, and the melting and freezing plateaux were evaluated by means of radiation thermometry. The repeatability of the TiC C eutectic within a day was 60 mK with a melting range roughly 200 mK. The repeatability of the melting temperature of the WC C peritectic within 1 day was 17 mK with a melting range of ˜70 mK. The repeatability of the freezing temperature of the WC C peritectic was 21 mK with a freezing range less than 20 mK. One of the TiC C cells was constructed from a TiC and graphite powder mixture. The filling showed the reaction with the graphite crucible was suppressed and the ingot contained less voids, although the lack of high-purity TiC powder poses a problem. The WC C cells were easily constructed, like metal carbon eutectic cells, without any evident reaction with the crucible. From these results, it is concluded that the WC C peritectic has more potential than the TiC C eutectic as a high-temperature reference point. The investigation of the purification of the TiC C cell during filling and the plateau observation are also reported.

Sasajima, Naohiko; Yamada, Yoshiro

2008-06-01

178

Modeling of Transient Heat Transfer in Zinc Fixed-Point Cell  

NASA Astrophysics Data System (ADS)

The current fixed-point calibration practice relies on furnaces that provide best achievable uniform temperature distribution, limiting the temperature gradients to about 10 mK to 20 mK along the ingot length. This paper outlines a numerical study conducted to further reveal the influences of the temperature gradients on the physical process involved and to bring some estimates for their influence on the plateau behavior. The mathematical model of the physical process is presented, along with the numerical models used through the FLUENT software package: the transient conductive heat transfer model, the discrete ordinates radiative heat transfer model, and the solidification model. The final model is reduced to axial symmetry for the sake of feasibility with the available computational resources. The convective heat transfer is neglected as it was considered to be of minor importance for the process itself. The geometrical model covers the entire fixed-point cell assembly and distinguishes each of its elements. The paper presents six cases, varying the temperature gradients in the boundary conditions and the cold-rodding. Their influence on the physical process is explained through the temperature fields presented. The study shows that a gradient of ±1 K · m-1 influences the plateau solely in its duration by either prolonging or shortening it by approximately 20 min.

Krizmanic, S.; Veliki, T.; Zvizdic, D.

2011-01-01

179

Components of a Variance Model for the Analysis of Repeated Measurements in Fixed-Point Comparisons  

NASA Astrophysics Data System (ADS)

Experimental design is a statistical tool concerned with the planning of experiments to obtain the maximum amount of information from the available resources. This tool may be applied to metrology, especially for the analysis of a large number of repeated measurements (replicates) of short-term repeatability and the medium-term and long-term reproducibilities, enabling the inclusion of these “time-dependent sources of variability” in the uncertainty budget. The realization of the International Temperature Scale of 1990 (ITS-90) scale requires that laboratories usually have more than one cell for each fixed point, for comparison on a regular basis. The calculation of the uncertainty of such comparisons is considered here, taking into account these time-dependent sources of variability. These components of the uncertainty evaluated by a Type A method are obtained by the statistical analysis of the experimental results using the components of a variance model for designs consisting of nested or hierarchical sequences of measurements, as foreseen by the mainstream GUM. An application example of a balanced nested structure in the comparison of two fixed-point cells is presented.

Filipe, Eduarda

2008-06-01

180

Investigation of Furnace Uniformity and its Effect on High-Temperature Fixed-Point Performance  

NASA Astrophysics Data System (ADS)

A large-area furnace BB3500YY was designed and built at the VNIIOFI as a furnace for high-temperature metal (carbide)-carbon (M(C)-C) eutectic fixed points and was then investigated at the NMIJ. The dependence of the temperature uniformity of the furnace on various heater and cell holder arrangements was investigated. After making some improvements, the temperature of the central part of the furnace was uniform to within 2K over a length of 40 mm—the length of the fixed-point cell—at a temperature of 2,500°C. With this furnace, the melting plateaux of Re-C and TiC-C were shown to be better than those observed in other furnaces. For instance, a Re-C cell showed melting plateaux with a 0.1K melting range and a duration of about 40 min. Furthermore, to verify the capability of the furnace to fill cells, one Re-C and one TiC-C cell were made using the BB3500YY. The cells were then compared to a Re-C cell made in a Nagano furnace and a TiC-C cell filled in a BB3200pg furnace. The agreement in plateau shapes demonstrates the capability of the BB3500YY furnace to also function as a filling furnace.

Khlevnoy, B.; Sakharov, M.; Ogarev, S.; Sapritsky, V.; Yamada, Y.; Anhalt, K.

2008-02-01

181

Quantum-corrected drift-diffusion models: Solution fixed point map and finite element approximation  

NASA Astrophysics Data System (ADS)

This article deals with the analysis of the functional iteration, denoted Generalized Gummel Map (GGM), proposed in [C. de Falco, A.L. Lacaita, E. Gatti, R. Sacco, Quantum-Corrected Drift-Diffusion Models for Transport in Semiconductor Devices, J. Comp. Phys. 204 (2) (2005) 533-561] for the decoupled solution of the Quantum Drift-Diffusion (QDD) model. The solution of the problem is characterized as being a fixed point of the GGM, which permits the establishment of a close link between the theoretical existence analysis and the implementation of a numerical tool, which was lacking in previous non-constructive proofs [N.B. Abdallah, A. Unterreiter, On the stationary quantum drift-diffusion model, Z. Angew. Math. Phys. 49 (1998) 251-275, R. Pinnau, A. Unterreiter, The stationary current-voltage characteristics of the quantum drift-diffusion model, SIAM J. Numer. Anal. 37 (1) (1999) 211-245]. The finite element approximation of the GGM is illustrated, and the main properties of the numerical fixed point map (discrete maximum principle and order of convergence) are discussed. Numerical results on realistic nanoscale devices are included to support the theoretical conclusions.

de Falco, Carlo; Jerome, Joseph W.; Sacco, Riccardo

2009-03-01

182

Fixed-point properties of the Ising ferromagnet on the Hanoi networks  

NASA Astrophysics Data System (ADS)

The Ising model with ferromagnetic couplings on the Hanoi networks is analyzed with an exact renormalization group. In particular, the fixed points are determined and the renormalization- flow for certain initial conditions is analyzed. Hanoi networks combine a one-dimensional lattice structure with a hierarchy of long-range bonds to create a mix of geometric and small-world properties. Generically, those small-world bonds result in nonuniversal behavior, i.e., fixed points and scaling exponents that depend on temperature and the initial choice of coupling strengths. It is shown that a diversity of different behaviors can be observed with seemingly small changes in the structure of the networks. Defining interpolating families of such networks, we find tunable transitions between regimes with power-law and certain essential singularities in the critical scaling of the correlation length. These are similar to the so-called inverted Berezinskii-Kosterlitz-Thouless transition previously observed only in scale-free or dense networks.

Boettcher, S.; Brunson, C. T.

2011-02-01

183

Optimization of the thermogauge furnace for realizing high temperature fixed points  

NASA Astrophysics Data System (ADS)

The thermogauge furnace was commonly used in many NMIs as a blackbody source for calibration of the radiation thermometer. It can also be used for realizing the high temperature fixed point(HTFP). According to our experience, when realizing HTFP we need the furnace provide relative good temperature uniformity to avoid the possible damage to the HTFP. To improve temperature uniformity in the furnace, the furnace tube was machined near the tube ends with a help of a simulation analysis by "ansys workbench". Temperature distributions before and after optimization were measured and compared at 1300 °C, 1700°C, 2500 °C, which roughly correspond to Co-C(1324 °C), Pt-C(1738 °C) and Re-C(2474 °C), respectively. The results clearly indicate that through machining the tube the temperature uniformity of the Thermogage furnace can be remarkably improved. A Pt-C high temperature fixed point was realized in the modified Thermogauge furnace subsequently, the plateaus were compared with what obtained using old heater, and the results were presented in this paper.

Wang, T.; Dong, W.; Liu, F.

2013-09-01

184

A Temperature Fixed Point Near 58C: The triple point of ultrapure succinonitrile could be used to calibrate thermometers between 0 and 100C.  

National Technical Information Service (NTIS)

This citation summarizes a one-page announcement of technology available for utilization. A new secondary 'fixed point' for defining the international Practical Temperature Scale has emerged from improved materials-processing methods for the organic subst...

1982-01-01

185

Adaptive array beamforming with fixed-point arithmetic matrix inversion using Givens rotations  

NASA Astrophysics Data System (ADS)

Adaptive array systems require the periodic solution of the well-known w=R1v equation in order to compute optimum adaptive array weights. The covariance matrix R is estimated by forming a product of noise sample matrices X:R=XHX. The operations-count cost of performing the required matrix inversion in real time can be prohibitively high for a high bandwidth system with a large number of sensors. Specialized hardware may be required to execute the requisite computations in real time. The choice of algorithm to perform these computations must be considered in conjunction with the hardware technology used to implement the computation engine. A systolic architecture implementation of the Givens rotation method for matrix inversion was selected to perform adaptive weight computation. The bit-level systolic approach enables a simple ASIC design and a very low power implementation. The bit-level systolic architecture must be implemented with fixed-point arithmetic to simplify the propagation of data through the computation cells. The Givens rotation approach has a highly parallel implementation and is ideally suited for a systolic implementation. Additionally, the adaptive weights are computed directly from the sample matrix X in the voltage domain, thus reducing the required dynamic range needed in carrying out the computations. An analysis was performed to determine the required fixed-point precision needed to compute the weights for an adaptive array system operating in the presence of interference. Based on the analysis results, it was determined that the precision of a floating-point computation can be well approximated with a 13-bit to 19-bit word length fixed point computation for typical system jammer-to-noise levels. This property has produced an order-of-magnitude reduction in required hardware complexity. A synthesis-based ASIC design process was used to generate preliminary layouts. These layouts were used to estimate the area and throughput of the VLSI QR decomposition architecture. The results show that this QR decomposition process, when implemented into a full-custom design, provides a computation time that is two orders of magnitude faster than a state-of-the-art microprocessor.

Rabinkin, Daniel V.; Song, William; Vai, M. Michael; Nguyen, Huy

2001-11-01

186

Assessment of correct fixing rate for precise point positioning ambiguity resolution on a global scale  

NASA Astrophysics Data System (ADS)

Ambiguity resolution (AR) for a single receiver has been a popular topic in Global Positioning System (GPS) recently. Ambiguity-resolution methods for precise point positioning (PPP) have been well documented in recent years, demonstrating that it can improve the accuracy of PPP. However, users are often concerned about the reliability of ambiguity-fixed PPP solution in practical applications. If ambiguities are fixed to wrong integers, large errors would be introduced into position estimates. In this paper, we aim to assess the correct fixing rate (CFR), i.e., number of ambiguities correctly fixing to the total number of ambiguities correctly and incorrectly fixing, for PPP user ambiguity resolution on a global scale. A practical procedure is presented to evaluate the CFR of PPP user ambiguity resolution. GPS data of the first 3 days in each month of 2010 from about 390 IGS stations are used for experiments. Firstly, we use GPS data collected from about 320 IGS stations to estimate global single-differenced (SD) wide-lane and narrow-lane satellite uncalibrated phase delays (UPDs). The quality of UPDs is evaluated. We found that wide-lane UPD estimates have a rather small standard deviation (Std) between 0.003 and 0.004 cycles while most of Std of narrow-lane estimates are from 0.01 to 0.02 cycles. Secondly, many experiments have been conducted to investigate the CFR of integer ambiguity resolution we can achieve under different conditions, including reference station density, observation session length and the ionospheric activity. The results show that the CFR of PPP can exceed 98.0 % with only 1 h of observations for most user stations. No obvious correlation between the CFR and the reference station density is found. Therefore, nearly homogeneous CFR can be achieved in PPP AR for global users. At user end, higher CFR could be achieved with longer observations. The average CFR for 30-min, 1-h, 2-h and 4-h observation is 92.3, 98.2, 99.5 and 99.7 %, respectively. In order to get acceptable CFR, 1 h is a recommended minimum observation time. Furthermore, the CFR of PPP can be affected by diurnal variation and geomagnetic latitude variation in the ionosphere. During one day at the hours when rapid ionospheric variations occur or in low geomagnetic latitude regions where equatorial electron density irregularities are produced relatively frequently, a significant degradation of the CFR is demonstrated.

Zhang, Xiaohong; Li, Pan

2013-06-01

187

Numerical Modeling of Heat Flux in Fixed-Point Cells Due to the Hydrostatic-Head Effect  

Microsoft Academic Search

The article presents the numerical analysis of a particular thermal effect, which occurs during the calibration of standard\\u000a platinum resistance thermometers in fixed-point cells. The temperature within the fixed-point cell varies linearly with the\\u000a immersion depth due to the hydrostatic-head effect, so a quasi-linear temperature gradient in the vertical direction is inherently\\u000a present. If there is a temperature gradient, a

V. Batagelj; J. Bojkovski; J. Drnovšek

188

New Filling Technique and Performance Evaluations of the Cr3C2-C Peritectic Fixed Point  

NASA Astrophysics Data System (ADS)

The Cr3C2-C peritectic fixed point was investigated to test its capability to serve as a practical high-temperature fixed point. An improved filling technique where C/C sheet works as a wick and graphite paper as a hopper was applied successfully, and the long-term stability of the peritectic cell was evaluated by means of radiation thermometry. The repeatability of the melting point in one day was 7 mK with a melting range of approximately 100 mK. The cell was aged for 7 days, and the evaluated 56 melting temperatures during this period all fall within 90 mK, with a standard deviation of 19 mK. X-ray transmission photos showed that the ingot was filled uniformly in the crucible. After the evaluation of long-term stability, no clear degradation of the ingot shape and no leakage of molten metal were observed. From these results, it can be concluded that the Cr3C2-C peritectic cell has good stability and robustness, and the new filling technique was established. The impurity effect on the Cr3C2-C peritectic cell was also investigated by adding tungsten powder to another cell as the impurity component. After the observation of melting and freezing plateaux, the cell was cut in half to analyze the microstructure by means of electron probe microanalysis (EPMA) and laser ablation inductively coupled plasma mass spectrometer (LA-ICP-MS). The high concentration of impurity was observed in the area of the chromium-rich domain (eutectic mixture of Cr7C3 and Cr3C2), which suggests that impurities were rejected from the Cr3C2 peritectic phase during the peritectic freezing and were accumulated in the Cr7C3-Cr3C2 eutectic phase. This explains why the impurity effect is more severe for the Cr7C3-Cr3C2 eutectic point than for the Cr3C2-C peritectic point.

Sasajima, N.; Lowe, D.; Bai, C.; Yamada, Y.; Ara, C.

2011-12-01

189

Fixed-point rubbing fault characteristic analysis of a rotor system based on contact theory  

NASA Astrophysics Data System (ADS)

In this paper, fault characteristics of a single span rotor system with two discs are investigated when the rubbing between a disc and an elastic rod (a fixed limiter) occurs. First, a finite element (FE) model of the rotor system is developed, a point–point contact model is established to simulate the rotor–stator rubbing by simplifying the disc and the rod as two contact points, and then the two models are coupled by contact force. In addition, the augmented Lagrangian method is applied to deal with contact constraint conditions and the coulomb friction model is used to simulate rotor–stator frictional characteristics. The vibration features of the rotor system with rubbing are analyzed with respect to the effects of the gaps between the disc and the rod, the contact stiffnesses under three typical cases with different rotating speeds. The simulation results show that different rotor motions appear, such as period-one motion (P1), P2 and P3 with the increasing rotating speeds, which are in agreement with the experimental measurements. Besides, the gap between the disc and the rod as well as the contact stiffness has a main influence on the vibration intensity and collision rebound forms.

Ma, Hui; Shi, Chaoyang; Han, Qingkai; Wen, Bangchun

2013-07-01

190

Stability analysis for stochastic Volterra-Levin equations with Poisson jumps: Fixed point approach  

NASA Astrophysics Data System (ADS)

This paper is devoted to investigate a class of stochastic Volterra-Levin equations with Poisson jumps. To the best of the authors' knowledge, till now, the stability problem for this class of new systems has not yet been solved since Poisson jumps are considered. The main objective of this paper is to fill the gap. By using the fixed point theory, we first study the existence and uniqueness of the solution as well as the pth moment exponential stability for the considered system. Then based on the well known Borel-Cantelli lemma, we prove that the solution is almost surely pth moment exponentially stable. Our results improve and generalize those given in the previous literature. Finally, two simple examples are provided to illustrate the effectiveness of the obtained results.

Guo, Lifang; Zhu, Quanxin

2011-04-01

191

Self-validating type C thermocouples to 2300 °C using high temperature fixed points  

NASA Astrophysics Data System (ADS)

Above 1500 °C, tungsten-rhenium (W-Re) thermocouples are the most commonly used contact thermometers because they are practical and inexpensive. However in general loss of calibration is very rapid, and, due to their embrittlement at high temperature, it is generally not possible to remove them for recalibration from the process environments in which they are used. Even if removal for recalibration was possible this would be of, at best, very limited use due to large inhomogeneity effects. Ideally, these thermocouples require some mechanism to monitor their drift in-situ. In this study, we describe self-validation of Type C (W5%Re/W26%Re) thermocouples by means of miniature high temperature fixed points comprising crucibles containing respectively Co-C, Pt-C, Ru-C, and Ir-C eutectic alloys. An overview of developments in this area is presented.

Pearce, J. V.; Elliott, C. J.; Machin, G.; Ongrai, O.

2013-09-01

192

Miniature Co-C eutectic fixed-point cells for self-validating thermocouples  

NASA Astrophysics Data System (ADS)

Miniature fixed-point cells have been constructed using ingots of Co-C eutectic alloy, with the aim of constructing self-validating thermocouples for in situ calibration. The design consists of a cylindrical graphite crucible, diameter 6 mm, containing the ingot, integrated into the measuring junction of a type R thermocouple. Two sizes of cell were studied, with internal volumes 124 and 64 mm3 respectively. A detailed study of the characteristics of the two designs shows a correlation between the emf at the melting temperature, and the furnace temperature. This correlation is dramatically reduced for the smaller cell. The correlation is characterized extensively. The smaller cell provides the best overall performance. The repeatability of both cells is of the order of 0.1 °C.

Ongrai, O.; Pearce, J. V.; Machin, G.; Sweeney, S. J.

2011-01-01

193

Thermal modelling comparing high temperature fixed point measurements by contact and non-contact thermometry  

NASA Astrophysics Data System (ADS)

This paper reports thermal modelling that aims to establish if the measurement method - either by a radiation thermometer or by a thermocouple - significantly influences the measured temperature of the high temperature fixed points Co-C, Pd-C and Ru-C. It is clear that both measurement techniques have specific physical characteristics which may affect the temperature measured during the melting plateau. With the radiation thermometer, the radiation heat transfer is directly influenced by the environment because the back-wall is effectively viewing the cold outside environment. In the case of a thermocouple direct viewing of the outside world is blocked so radiation transport is significantly reduced; however, in the case of the thermocouple there is a different component of heat transfer, namely conduction from the thermowell walls in contact with the thermocouple along the thermocouple stem itself.

Castro, P.; Machin, G.; Pearce, J. V.

2013-09-01

194

An experimental verification of saturated salt solution-based humidity fixed points  

NASA Astrophysics Data System (ADS)

The high instability and hysterisis of the relative humidity sensors currently available on the market render necessary simple and economic calibration methodologies that can be used as a secondary of working standards. The chemical equilibrium-type systems based on saturated aqueous salt solutions, even though simple and economical, are not always metrologically satisfactory for calibration. They can, in fact, be unreliable, when some fundamental requirements are neglected: also, unacceptable discrepancies continue to exist in the equilibrium relative humidity reference data of saturated aqueous salt solutions furnished by both literature and standards. To highlight the factors that increase the reliability of calibrations with saturated aqueous salt solutions, the authors of this paper have redetermined the equilibrium relative humidity reference data of 11 saturated aqueous salt solutions at ambient pressure and temperature. The solutions chosen were the ones generally used as fixed points to obtain a relative humidity calibration scale.

Carotenuto, A.; Dell'Isola, M.

1996-11-01

195

Progress report for the CCT-WG5 high temperature fixed point research plan  

NASA Astrophysics Data System (ADS)

An overview of the progress in High Temperature Fixed Point (HTFP) research conducted under the auspices of the CCT-WG5 research plan is reported. In brief highlights are: Provisional long term stability of HTFPs has been demonstrated. Optimum construction methods for HTFPs have been established and high quality HTFPs of Co-C, Pt-C and Re-C have been constructed for thermodynamic temperature assignment. The major sources of uncertainty in the assignment of thermodynamic temperature have been identified and quantified. The status of absolute radiometric temperature measurement has been quantified through the circulation of a set of HTFPs. The measurement campaign to assign low uncertainty thermodynamic temperatures to a selected set of HTFPs will begin in mid-2012. It is envisaged that this will be complete by 2015 leading to HTFPs becoming routine reference standards for radiometry and high temperature metrology.

Machin, G.; Anhalt, K.; Bloembergen, P.; Sadli, M.; Yamada, Y.; Woolliams, E. R.

2013-09-01

196

Fixed points and exponential stability of mild solutions of stochastic partial differential equations with delays  

NASA Astrophysics Data System (ADS)

The fixed-point theory is first used to consider the stability for stochastic partial differential equations with delays. Some conditions for the exponential stability in pth mean as well as in sample path of mild solutions are given. These conditions do not require the monotone decreasing behavior of the delays, which is necessary in [T. Caraballo, K. Liu, Exponential stability of mild solutions of stochastic partial differential equations with delays, Stoch. Anal. Appl. 17 (1999) 743-763; Ruhollan Jahanipur, Stability of stochastic delay evolution equations with monotone nonlinearity, Stoch. Anal. Appl. 21 (2003) 161-181]. Even in this special case, our results also improve the results in [T. Caraballo, K. Liu, Exponential stability of mild solutions of stochastic partial differential equations with delays, Stoch. Anal. Appl. 17 (1999) 743-763].

Luo, Jiaowan

2008-06-01

197

Fixed-point analysis and realization of a blind beamforming algorithm  

NASA Astrophysics Data System (ADS)

We present the fixed-point analysis and realization of a blind beamforming algorithm. This maximum-power beamforming algorithm consists of the computation of a correlation matrix and its dominant eigenvector, and we propose that the later be accomplished by the power method. After analyzing the numerical stability of the power method, we derive a division-free form of the algorithm. Based on a block-Toeplitz assumption, we design an FIR filter based system to realize both the correlation computation and the power method. Our ring processor, which is optimized to implement digital filters, is used as the core of the architecture. A special technique for dynamically switching filter inputs is shown to double the system throughput. Finally we discuss the issue of hardware/software hybrid realization.

Xu, Fan; Fu, Dengwei; Willson, Alan N.

1999-11-01

198

Polynomial fixed-point algorithm applied to the electromagnetic analysis of one-dimensional continuous structures  

NASA Astrophysics Data System (ADS)

We develop a general procedure that allows the determination of the spectral transmittance and reflectance at normal incidence for arbitrary one-dimensional continuous materials as well as the analysis of the time-domain propagation of pulses through them. This procedure consists of a generalization of Fresnel equations, and it is supported by an iterative algorithm also developed here: the polynomial fixed-point algorithm (PFPA). We apply these theoretical results to some concrete examples, such as determining the transmittance and reflectance for an absorptionless photonic crystal, an optical rugate filter, and a photonic crystal with periodic absorption. We also analyze the time-domain propagation of ultrashort Gaussian pulses through different structures.

Perez-Molina, M.; Carretero-Lopez, Luis

2007-06-01

199

Optimization of SPRT measurements of freezing in a zinc fixed-point cell  

NASA Astrophysics Data System (ADS)

A numerical model of solute and heat transport in extremely pure materials is described. Its purpose is to characterize the effect of impurities on the freezing curves of metals containing impurities at the level of less than 1 part per million. It is used to simulate experiments performed using a commercially available zinc fixed-point cell for SPRT calibrations. The aim is to determine the effect of different vertical temperature gradients on the freezing curve and to find out whether a range of conditions could be determined where there was a good fit between theory and experiment. For this fixed-point cell, agreement between the model and experiment improves as the distribution coefficient k ? 0. It is found that the model only agrees with the measured freezing curves over the entire freeze for a narrow range of furnace settings where the temperature profile is most uniform. We suggest that this is because if the furnace settings are not optimized, the solid does not grow uniformly, and freezing may continue in regions remote from the SPRT after the material in the vicinity of the SPRT has finished freezing, so distorting the freezing curve. This effect is not present in the model and so the method presented here enables optimization of the furnace to ensure the SPRT is surrounded by a liquid-solid interface over the entire freezing range. We find that the optimum thermal environment is extremely sensitive to the furnace settings; the optimum thermal environment is found when the temperature is slightly cooler at the top of the cell, as measured in the re-entrant well of the cell. We note that optimizing the freezing process is a necessary step towards using a thermal analysis to correct for the effects of impurities in the sample.

Pearce, J. V.; Veltcheva, R. I.; Lowe, D. H.; Malik, Z.; Hunt, J. D.

2012-06-01

200

FINITE p-GROUPS ADMITTING p-AUTOMORPHISMS WITH FEW FIXED POINTS  

NASA Astrophysics Data System (ADS)

The following theorem is proved: if a finite p-group P admits an automorphism of order p^k having exactly p^n fixed points, then it contains a subgroup of (p,\\, k,\\, n)-bounded index that is solvable of (p,\\,k)-bounded derived length. The proof uses Kreknin's theorem stating that a Lie ring admitting a regular (that is, without nontrivial fixed points) automorphism of finite order m, is solvable of m-bounded derived length f(m). Some techniques from the theory of powerful p-groups are also used, especially, from a recent work of Shalev, who proved that, under the hypothesis of the theorem, the derived length of P is bounded in terms of p, k, and n. The following general proposition is also used (this proposition is proved on the basis of Kreknin's theorem with the help of the Mal'tsev correspondence, given by the Baker-Hausdorff formula): if a nilpotent group G of class c admits an automorphism \\varphi of finite order m, then, for some (c,\\, m)-bounded number N=N(c,\\,m), the derived subgroup (G^N)^{(f(m))} is contained in the normal closure \\langle C_G(\\varphi)^G\\rangle of the centralizer C_G(\\varphi). The scheme of the proof of the theorem is as follows. Standard arguments show that P may be assumed to be a powerful p-group. Next, it is proved that P^{(f(p^k))} is nilpotent of (p,\\, k,\\, n)-bounded class. Then the proposition is applied to P^{(f(p^k))}. There exist explicit upper bounds for the functions from the statement of the theorem.Bibliography: 22 titles.

Khukhro, E. I.

1995-02-01

201

A New Generation of Multicells for Cryogenic Fixed Points at BNM/INM  

NASA Astrophysics Data System (ADS)

In January 2000 a European Project called ``MULTICELLS'' started, in the field of the realisation of low-temperature standards [1]. In the range from 14 K to 234 K, two competing designs of modular multi-compartment cells (multicells) for the realisation of low-temperature fixed points of the ITS-90 were developed and fabricated by two different partners: BNM-INM and IMGC [2]. The multicells device allows the calibration, in the same run, of up to three thermometers at all the ITS-90 triple points in the low-temperature range, including the mercury point. Several secondary reference points could be optionally added to the system. The limitation of the number of elements is mainly due to thermal effects (thermal homogeneity and response time) and to the dimension of the experimental space of the calorimeter used for measuring the melting curves. In order to reduce the response time, the phase-transition interface of each element of the multicell containing the substance must be in close thermal contact with the thermometers to be calibrated, although the different elements must be easily separated. BNM-INM developed and improved the device in co-operation with the testing partners from other institutes represented by the authors. The technical choices leading to the BNM-INM design are presented and justified. Experimental results on the thermal behaviour of the multicells are given. The tests were performed in accordance with a detailed protocol in order to enable a direct comparison of different designs of the multicells.

Hermier, Y.; Pitre, L.; Geneville, C.; Vergé, A.; Bonnier, G.; Head, D. I.; Fellmuth, B.; Wolber, L.; Szmyrka-Grzebyk, A.; Lipinski, L.; de Groot, M. J.; Peruzzi, A.

2003-09-01

202

Bilateral comparison of tin fixed point cells between INMETRO and NPL  

NASA Astrophysics Data System (ADS)

In April 2011, a bilateral comparison of tin fixed point cells (231.928 °C) took place at the facilities of the Temperature group at the National Physical Laboratory (NPL). The comparison was with a standard from the Thermal Metrology Division of the National Institute of Metrology, Quality and Technology (INMETRO). It involved two cells: the test cell was an open one constructed in late 2010 at the INMETRO Thermometry Laboratory as part of an MSc research project; the reference cell was a sealed one, constructed in 2000 at NPL, traceable to the UK national standard tin point. The materials employed in the construction of the cells were from different suppliers. The cell design, dimensions and construction procedures were also different. Three standard platinum resistance thermometers (SPRTs), each different models from different manufacturers, were used to undertake the comparison, one from INMETRO and two from NPL. The comparison was performed in quadruplicate, each combination using a different freezing plateau. The differing self-heating behaviour of the different SPRTs was taken into account. The methodology employed in this comparison is detailed in the present paper.

Silva, R. da; Veltcheva, R. I.; Gray, J.; Pearce, J. V.; Machin, G.; Teixeira, R. N.

2013-09-01

203

Investigation of the Behavior of the Co C Eutectic Fixed Point  

NASA Astrophysics Data System (ADS)

The behavior of the Co C eutectic fixed point was investigated at INRIM. Several cells of different design and volume, and filled with cobalt of different purity were constructed and investigated with both Pt/Pd thermocouples and radiation thermometers. The melting behavior was investigated with respect to the melting rate, the pre-freezing rate, and the annealing time. The melting temperatures, as defined, were not significantly affected by the different testing conditions, even if the shape and duration of the plateaux were influenced. Several tens of melt and freeze cycles were performed with the different cells. The spread in the results for all of the different conditions was very limited in extent, giving rise to a standard deviation of less than 0.04 °C; a repeatability of better than 0.02 °C was found with both Pt/Pd thermocouples and radiation thermometers. The results of our measurements are encouraging and confirm the suitability of Co C as a reference point for the high-temperature range in a possible future temperature scale. Investigations of long-term stability remain ongoing.

Girard, F.; Battuello, M.; Florio, M.

2007-12-01

204

There is no non-zero stable fixed point for dense networks in the homogeneous Kuramoto model  

NASA Astrophysics Data System (ADS)

This paper is concerned with the existence of multiple stable fixed point solutions of the homogeneous Kuramoto model. We develop a necessary condition for the existence of stable fixed points for the general network Kuramoto model. This condition is applied to show that for sufficiently dense n-node networks, with node degrees at least 0.9395(n-1), the homogeneous (equal frequencies) model has only one stable fixed point solution over the full space of phase angles in the range -? to ?. This is the zero fixed point solution defined by all phase angle differences being zero. This result, together with existing research, proves a conjecture of Verwoerd and Mason (2007 Proc. of the American Control Conf. pp 4613-8) that for the complete network and the homogeneous model, the zero fixed point has a basin of attraction consisting of the entire space minus a set of measure zero. The necessary conditions are also tested to see how close to sufficiency they might be by applying them to a class of regular degree networks studied by Wiley et al (2006 Chaos 16 015103).

Taylor, Richard

2012-02-01

205

Performance and accuracy comparison of fixed and floating-point realizations of the Active Power Filter control algorithm  

Microsoft Academic Search

The comparison of performance and accuracy of the active power filter control algorithm realizations has been presented in the paper. The worked out algorithms are based on dq synchronous frame control strategy. The following Texas Instruments digital signal controllers were used for the realization: fixed-point TMS320F2812 and floating-point TMS320F28335. The TMS320F28335 digital signal controller is the first floating-point controller in

Marian Pasko; M. Maciazek; Dawid Bula

2008-01-01

206

Influence of impurities on the fixed-point temperature of zinc: estimations by the SIE method and practical limitations  

NASA Astrophysics Data System (ADS)

This publication deals with the practical challenge of describing the impurity influence on the fixed-point temperature of zinc. For this, the sum of individual estimate (SIE) approach is applied to miniaturized fixed-point cells (MFPC) filled with high-purity zinc that can be used in industrial applications. This includes comparative analyses by glow discharge mass spectroscopy as well as mass spectroscopy with inductive coupled plasma to quantify the impurity concentrations in zinc. Furthermore, the element-specific and concentration-dependent temperature deviations are presented for the fixed-point material zinc. For this, binary phase diagrams as well as thermal calculations and experimental data were analysed to extract the relevant sensitivity coefficients. Besides, results from SIE analyses of MFPCs are presented and their uncertainties are compared. On this basis, practical limits of the SIE method are identified and discussed.

Krapf, G.; Mammen, H.; Blumröder, G.; Fröhlich, T.

2012-07-01

207

Assessment of tungsten/rhenium thermocouples with metal-carbon eutectic fixed points up to 1500°C  

NASA Astrophysics Data System (ADS)

Four Type A thermocouples and two Type C thermocouples were calibrated at the Au fixed point and Co-C and Pd-C eutectic fixed points. The thermocouples were exposed to 1330 °C for a total of 100 hours. The maximum drift due to the exposure was found to be 4.8 °C. The fixed-point calibration EMF of these thermocouples deviated by less than 0.86% from the temperature specified by the standards ASTM E230-2003 for Type C and GOSTR 8.585-2001 for Type A. The length of one of Type A thermocouples A52 is longer than the others by 150mm. Making use of this provision it was possible to place annealed part of A52 to the temperature gradient part of calibration arrangement every time. Therefore observed aging effect was as low as 0.5 °C compared to the other thermocouples.

Gotoh, M.

2013-09-01

208

An InGaAs detector based radiation thermometer and fixed-point blackbodies for temperature scale realization at NIM  

NASA Astrophysics Data System (ADS)

In this paper, we describe an InGaAs detector based radiation thermometer (IRT) and new design of fixed-point blackbodies, including Sn, Zn, Al and Cu, for the establishment of a temperature scale from 200 °C to 1085 °C at the National Institute of Metrology of China. The construction and calibration of the IRT with the four fixed-point blackbodies are described. Characteristics of the IRT, such as the size-of-source effect, the amplifier performance and its stability are determined. The design of the four fixed-points, with 10 mm diameter of aperture and 0.9999 emissivity, is described. The uncertainty of the scale realization is elaborated.

Hao, X.; Yuan, Z.; Wang, J.; Lu, X.

2013-09-01

209

Collective sensing: a fixed-point approach in the metric space  

NASA Astrophysics Data System (ADS)

Conventional wisdom in signal processing heavily relies on the concept of inner product defined in the Hilbert space. Despite the popularity of Hilbert-space formulation, we argue it is overly-structured to account for the complexity of signals arising from the real-world. Inspired by the works on fractal image decoding and nonlocal image processing, we propose to view an image as the fixed-point of some nonexpansive mapping in the metric space in this paper. Recently proposed BM3D-based denoising and nonlocal TV filtering can be viewed as the special cases of nonexpansive mappings while differ on the choice of clustering techniques. The physical interpretation of clustering-based nonexpansive mappings is that they convey organizational principles of the dynamical system underlying the signals of interest. There is an interesting analogy between phases of matters in statistical physics and types of structures in image processing. From this perspective, image reconstruction can be solved by a deterministic-annealing based global optimization approach which collectively exploits the a priori information about unknown image. The potential of this new paradigm, which we call "ollective sensing" is demonstrated on the lossy compression application where significant gain over current state-of-the-art (SPIHT) coding scheme has been achieved.

Li, Xin

2010-07-01

210

Realization of the WC-C peritectic fixed point at NIM and NMIJ  

NASA Astrophysics Data System (ADS)

Three WC-C peritectic fixed point cells, constructed from different sources of tungsten with different nominal purities, were measured at NIM and NMIJ. The three cells were constructed at NMIJ by NIM and NMIJ staffs, and T90 values of the three cells were measured at NMIJ during the period 31 Aug. to 25 Dec. 2009. Thereafter, the three cells were then transported to NIM, and T90 values of these cells were measured from 7 Dec. 2011 to 9 Jan. 2012. The results showed that T90 values of the three cells measured at the two institutes agreed within 0.4 °C with the combined scale comparison uncertainty of 1.7 °C (k = 2). The main component of the uncertainty is not the uncertainty due to impurities of the cells but the scale uncertainty and the stability of the measurement system. From these results it can be concluded that the WC-C cell is stable enough to provide new means of international high-temperature scale comparison above 3000 K.

Wang, T.; Sasajima, N.; Yamada, Y.; Bai, C.; Yuan, Z.; Dong, W.; Ara, C.; Lu, X.

2013-09-01

211

A miniature high-temperature fixed point for self-validation of type C thermocouples  

NASA Astrophysics Data System (ADS)

Reliable high-temperature (>1500 °C) measurement is crucial for a wide range of industrial processes as well as specialized applications, e.g. aerospace. The most common type of sensor used for high-temperature measurement is the thermocouple. At and above 1500 °C, tungsten-rhenium (W-Re) thermocouples are the most commonly used temperature sensors due to their utility up to 2300 °C. However, the achievable accuracy of W-Re thermocouples is seriously limited by the effects of their inhomogeneity, drift and hysteresis. Furthermore, due to their embrittlement at high temperature, the removal of these thermocouples from environments such as nuclear power plants or materials processing furnaces for recalibration is generally not possible. Even if removal for recalibration were possible, this would be of, at best, very limited use due to large inhomogeneity effects. Ideally, these thermocouples require some mechanism to monitor their drift in situ. In this study, we describe a miniature Co-C eutectic fixed-point cell to evaluate the stability of type C (W5%Re/W26%Re) thermocouples by means of in situ calibration.

Ongrai, O.; Pearce, J. V.; Machin, G.; Sweeney, S. J.

2011-10-01

212

Artifact Removal from Biosignal using Fixed Point ICA Algorithm for Pre-processing in Biometric Recognition  

NASA Astrophysics Data System (ADS)

In the modern world of automation, biological signals, especially Electroencephalogram (EEG) and Electrocardiogram (ECG), are gaining wide attention as a source of biometric information. Earlier studies have shown that EEG and ECG show versatility with individuals and every individual has distinct EEG and ECG spectrum. EEG (which can be recorded from the scalp due to the effect of millions of neurons) may contain noise signals such as eye blink, eye movement, muscular movement, line noise, etc. Similarly, ECG may contain artifact like line noise, tremor artifacts, baseline wandering, etc. These noise signals are required to be separated from the EEG and ECG signals to obtain the accurate results. This paper proposes a technique for the removal of eye blink artifact from EEG and ECG signal using fixed point or FastICA algorithm of Independent Component Analysis (ICA). For validation, FastICA algorithm has been applied to synthetic signal prepared by adding random noise to the Electrocardiogram (ECG) signal. FastICA algorithm separates the signal into two independent components, i.e. ECG pure and artifact signal. Similarly, the same algorithm has been applied to remove the artifacts (Electrooculogram or eye blink) from the EEG signal.

Mishra, Puneet; Singla, Sunil Kumar

2013-01-01

213

Infrared fixed point of the 12-fermion SU(3) gauge model based on 2-lattice Monte Carlo renomalization-group matching.  

PubMed

I investigate an SU(3) gauge model with 12 fundamental fermions. The physically interesting region of this strongly coupled system can be influenced by an ultraviolet fixed point due to lattice artifacts. I suggest to use a gauge action with an additional negative adjoint plaquette term that lessens this problem. I also introduce a new analysis method for the 2-lattice matching Monte Carlo renormalization group technique that significantly reduces finite volume effects. The combination of these two improvements allows me to measure the bare step scaling function in a region of the gauge coupling where it is clearly negative, indicating a positive renormalization group ? function and infrared conformality. PMID:22401055

Hasenfratz, Anna

2012-02-08

214

Study on the melting and freezing behaviour of high temperature binary eutectic fixed points using differential scanning calorimetry  

NASA Astrophysics Data System (ADS)

We have measured the heat flux accompanying the melting or freezing of metal (or metalloid)-carbon eutectics, using differential scanning calorimetry (DSC) to identify appropriate binary systems for secondary thermometry fixed points. Well-known alloy systems such as Fe-C and Ni-C showed reproducible endothermic and exothermic peaks that represent melting and freezing reactions in the DSC measurement. Furthermore, a new Si-C system with a eutectic composition showed reproducible melting and freezing peaks in the DSC measurements. Based on the results by DSC, we identified the Si-SiC eutectic point as a possible eutectic fixed point. To confirm this possibility, we made a Si-SiC cell for thermocouple thermometry and measured its melting and freezing characteristics using a Pt/Pd thermocouple. The melting temperature of the Si-SiC eutectic was reproducible to within 0.02 °C (one standard deviation). From the results, we found that Si-SiC has possibility as a new eutectic fixed point at temperatures around 1400 °C. We also concluded that DSC analysis could be used to measure the reproducibility of freezing and melting reactions that are to be used as fixed points for thermometry, because it is a rapid and easy-to-use tool for characterizing the thermal behaviour of materials with only a small sample.

Kwon, Su Yong; Kim, Yong-Gyoo; Yang, Inseok

2010-06-01

215

Infrared Fixed Point in the Strong Running Coupling: Unraveling the ?I = 1/2 Puzzle in K-Decays  

NASA Astrophysics Data System (ADS)

In this paper, we present an explanation for the ?I = 1/2 rule in K-decays based on the premise of an infrared fixed point ?IR in the running coupling ?s of quantum chromodynamics (QCD) for three light quarks u, d, s. At the fixed point, the quark condensate <\\bar {q}q> vac !=q 0 spontaneously breaks scale and chiral SU(3)L×SU(3)R symmetry. Consequently, the low-lying spectrum contains nine Nambu-Goldstone bosons: ?, K, ? and a QCD dilaton ?. We identify ? as the f0(500) resonance and construct a chiral-scale perturbation theory ?PT? for low-energy amplitudes expanded in ?s about ?IR. The ?I = 1/2 rule emerges in the leading order of ?PT? through a ?-pole term KS?????, with a gKS? coupling fixed by data on ????0?0 and KS???. We also determine RIR ?5 for the nonperturbative Drell-Yan ratio at ?IR.

Crewther, R. J.; Tunstall, Lewis C.

2013-08-01

216

Reciprocal Continuity and Common Fixed Point for two Pairs of Self-Maps Satisfying a Generalized Inequality  

NASA Astrophysics Data System (ADS)

We obtain a common fixed point for two pairs of self-maps on a complete metric space, one of which is reciprocally continuous and compatible, while the other weakly compatible, where all the four maps satisfy a generalized inequality. Our result is a significant generalization of that of Singh and Mishra.

Phaneendra, T.; Swatmaram

2012-10-01

217

Stationary point analysis of the one-dimensional lattice Landau gauge fixing functional, aka random phase XY Hamiltonian  

SciTech Connect

Research Highlights: > Exact results for all stationary points of some high-dimensional function are given. > They are interpreted as Gribov copies of a lattice Landau gauge fixing functional. > The Gribov ambiguity and the Neuberger problem in compact U(1) are illustrated. > Stationary points are used to discuss a criterion on the absence of phase transitions. - Abstract: We study the stationary points of what is known as the lattice Landau gauge fixing functional in one-dimensional compact U(1) lattice gauge theory, or as the Hamiltonian of the one-dimensional random phase XY model in statistical physics. An analytic solution of all stationary points is derived for lattices with an odd number of lattice sites and periodic boundary conditions. In the context of lattice gauge theory, these stationary points and their indices are used to compute the gauge fixing partition function, making reference in particular to the Neuberger problem. Interpreted as stationary points of the one-dimensional XY Hamiltonian, the solutions and their Hessian determinants allow us to evaluate a criterion which makes predictions on the existence of phase transitions and the corresponding critical energies in the thermodynamic limit.

Mehta, Dhagash, E-mail: dbmehta@syr.edu [Department of Physics, Syracuse University, Syracuse, NY 13244 (United States); Kastner, Michael, E-mail: kastner@sun.ac.za [National Institute for Theoretical Physics (NITheP), Stellenbosch 7600 (South Africa); Institute of Theoretical Physics, University of Stellenbosch, Stellenbosch 7600 (South Africa)

2011-06-15

218

Crustal deformation measurements in Central Japan determined by a global positioning system fixed-point network  

NASA Astrophysics Data System (ADS)

A Global Positioning System (GPS) fixed-point network has been operating in the Kanto and Tokai districts of central Japan since April 1988 to detect crustal deformation associated with the convergence of the Eurasian. Pacific, North American, and Philippine Sea plates and to monitor the deformation cycles of frequent large interplate and intraplate earthquakes. This 10-station network established by the National Research Institute for Earth Science and Disaster Prevention (NIED) is the first continuously monitoring network of its kind. We determine deformation within the network using two consecutive days of data every 2 weeks for the first 17 months of operations. We use a station and orbit relaxation method which relies exclusively on data collected within the NIED network, except for 1 week of global GPS tracking data which is used to determine initial station positions with respect to the global refrence frame. We detect, relative to a station on the Eurasian plate in central Japan, significant westward motion of 28 mm/yr of the northern tip of the Philippine Sea plate, which is subducting beneath the Eurasian plate at the Suruga trough. Our results support finite element models of collision of the Izu Block with the Eruasian plate based on earthquake focal mechanisms and plate block motions of the Japanese archipelago determined from conventional geodetic measurements over the last century. We detect southwestward motion of 18 mm/yr of the southeastern tip of the Eurasian plate, confirming expected surface extension of the subducted plate parallel to the Suruga trough axis. Significant vertical uplift with a velocity of 20 mm/yr is suggested at a sites inland of the Tokai district located in the Akaishi uplift zone and at a site on Hatsushima Island in Sagami Bay. The general tendency of vertical movements of the other site agrees with vertical velocities obtained from 70 years of geodetic leveling and with Quaternary vertical displacements determined from geomorphological and other geological evidence. We detect no significant crustal motion across the Fossa Magna tectonic zone in central Japan (often considered a plate boundary), across the Tokyo metropolitan area, nor across the Sagami trough associated with the subduction of the Philippine Sea plate beneath northeast Japan. Our results demonstrate the power of regionally based, continuously monitoring GPS networks for obtaining temporally dense meausrements of small horizontal and vertical crustal movements across plate boundary zones.

Bock, Yehuda

1992-08-01

219

Permanence of discrete-time Kolmogorov systems for two species and saturated fixed points  

Microsoft Academic Search

This paper considers the dynamics of a discrete-time Kolmogorov system for two-species populations. In particular, permanence of the system is considered. Permanence is one of the concepts to describe the species’ coexistence. By using the method of an average Liapunov function, we have found a simple sufficient condition for permanence of the system. That is, nonexistence of saturated boundary fixed

Ryusuke Kon

2004-01-01

220

A fixed-point iterative schema for error minimization in k-sparse decomposition  

Microsoft Academic Search

Analogously to the well known greedy strategy called Orthogonal Matching Pursuit (OMP), we present a new algorithm to solve the sparse approximation problem over redundant dictionaries where the input signal is restricted to be a linear combination of k atoms or fewer from a fixed dictionary. The basic strategy of our method rests on a family of nonlinear mappings which

Alessandro Adamo; Giuliano Grossi

2011-01-01

221

Investigation of differently designed Pd-C eutectic fixed-point cells for the calibration of thermocouples  

NASA Astrophysics Data System (ADS)

An interlaboratory comparison of the melting temperatures of three palladium-carbon (Pd-C) eutectic fixed-point cells of different designs and usable for the calibration of thermocouples was performed at NIM. Two Pt/Pd thermocouples were constructed for this particular purpose. One of the Pd-C eutectic cells is of conventional design and size; the two other cells are miniature fixed-point cells of different designs. The melting temperature of the conventional cell, PdC1-NIM, was slightly higher than the melting temperatures of the miniature cells by about 160 mK (PdCM2 of PTB) and 290 mK (PdC2-NIM). The melting temperatures of the two miniature Pd-C cells agree within their measurement uncertainties for k = 2 of about 135 mK. Furthermore, a new aspect of leakage effects often observed in the use of Pd-C cells is presented.

Edler, F.; Zheng, W.

2011-10-01

222

Constraints on “SECOND-ORDER Fixed POINT” QCD from the Ccfr Data on Deep Inelastic Neutrino-Nucleon Scattering  

NASA Astrophysics Data System (ADS)

The results of LO fixed point QCD (FP-QCD) analysis of the CCFR data for the nucleon structure function xF3(x, Q2) are presented. The predictions of FP-QCD, in which the Callan—Symanzik ?-function admits a second-order ultraviolet zero at ?=?0 are in good agreement with the data. Constraints for the possible values of the ?-function parameter b regulating how fast ?s(Q2) tends to its asymptotic value ?0?0 are found from the data. The corresponding values of ?0 are also determined. Having in mind our recent “first-order fixed point” QCD fit to the same data we conclude that despite the high precision and the large (x, Q2) kinematic range of the CCFR data they cannot discriminate between QCD and FP-QCD predictions for xF3(x, Q2).

Sidorov, Aleksander V.; Stamenov, Dimiter B.

223

The asymptotics of the return map of a singular point with fixed Newton diagram  

Microsoft Academic Search

We exhibit a large class of nondegenerate singular points in which necessary and sufficient conditions are given for monodromy. We compute the generalized first Lyapunov value, which is expressed in terms of the Newton diagram of the singular point. The computational algorithm proposed is based on writing the return map as the composition of transition mappings constructed using the diagram.

F. S. Berezovskaya; N. B. Medvedeva

1992-01-01

224

Two-stage fixed-bed gasifier with selectable middle gas off-take point  

DOEpatents

A two-stage fixed bed coal gasifier wherein an annular region is in registry with a gasification zone underlying a devolatilization zone for extracting a side stream of high temperature substantially tar-free gas from the gasifier. A vertically displaceable skirt means is positioned within the gasifier to define the lower portion of the annular region so that vertical displacement of the skirt means positions the inlet into the annular region in a selected location within or in close proximity to the gasification zone for providing a positive control over the composition of the side stream gas.

Strickland, L.D.; Bissett, L.A.

1991-12-31

225

On the orbital stability of pendulum-like oscillations and rotations of a symmetric rigid body with a fixed point  

NASA Astrophysics Data System (ADS)

We deal with the problem of orbital stability of planar periodic motions of a dynamically symmetric heavy rigid body with a fixed point. We suppose that the center of mass of the body lies in the equatorial plane of the ellipsoid of inertia. Unperturbed periodic motions are planar pendulum-like oscillations or rotations of the body around a principal axis keeping a fixed horizontal position. Local coordinates are introduced in a neighborhood of the unperturbed periodic motion and equations of the perturbed motion are obtained in Hamiltonian form. Regions of orbital instability are established by means of linear analysis. Outside the above-mentioned regions, nonlinear analysis is performed taking into account terms up to degree 4 in the expansion of the Hamiltonian in a neighborhood of unperturbed motion. The nonlinear problem of orbital stability is reduced to analysis of stability of a fixed point of the symplectic map generated by the equations of the perturbed motion. The coefficients of the symplectic map are determined numerically. Rigorous results on the orbital stability or instability of unperturbed motion are obtained by analyzing these coefficients. The orbital stability is investigated analytically in two limiting cases: small amplitude oscillations and rotations with large angular velocities when a small parameter can be introduced.

Bardin, Boris S.; Savin, Alexander A.

2012-05-01

226

Superconducting vortex profile from fixed point measurements the ``Lazy Fisherman'' tunneling microscopy method  

NASA Astrophysics Data System (ADS)

We introduce a mode of operation for studying the vortex phase in superconductors using scanning tunneling microscopy (STM). While in the conventional STM method, the tip is scanned over a sample in which a fixed vortex pattern is prepared, in our ``Lazy Fisherman'' method the STM tip is kept fixed at a selected location while the vortices are being moved by varying the applied magnetic field. By continuously acquiring the local tunneling conductance spectra, dI/dV(V), we detect the changes in the local density of states under the tip due to the vortex motion. With no need for scanning, the method permits one to extend the study of vortices to samples in which scanning is difficult or even impossible due to surface nonuniformity and allows one to study vortex dynamics. Using a statistical analysis of the spectra, we reconstruct the single vortex zero bias conductance profile. We apply the method to the c-axis face of a MgB2 single crystal sample and obtain a vortex profile with a coherence length, ? of 57+/-2 nm.

Kohen, A.; Cren, T.; Proslier, Th.; Noat, Y.; Sacks, W.; Roditchev, D.; Giubileo, F.; Bobba, F.; Cucolo, A. M.; Zhigadlo, N.; Kazakov, S. M.; Karpinski, J.

2005-05-01

227

CORRECTIVE ACTION DECISION DOCUMENT FOR CORRECTIVE ACTION UNIT 423: BUILDING 03-60 UNDERGROUND DISCHARGE POINT, TONOPAH TEST RANGE, NEVADA, REVISION 0, JUNE 1998.  

National Technical Information Service (NTIS)

This Corrective Action Decision Document has been prepared for the Area 3 Building 03-60 Underground Discharge Point (Corrective Action Unit 423) in accordance with the Federal Facility Agreement and Consent Order of 1996 (FFACO, 1996). Corrective Action ...

1998-01-01

228

Criticality governed by the stable renormalization fixed point of the Ising model in the hierarchical small-world network  

NASA Astrophysics Data System (ADS)

We study the Ising model in a hierarchical small-world network by renormalization group analysis and find a phase transition between an ordered phase and a critical phase, which is driven by the coupling strength of the shortcut edges. Unlike ordinary phase transitions, which are related to unstable renormalization fixed points (FPs), the singularity in the ordered phase of the present model is governed by the FP that coincides with the stable FP of the ordered phase. The weak stability of the FP yields peculiar criticalities, including logarithmic behavior. On the other hand, the critical phase is related to a nontrivial FP, which depends on the coupling strength and is continuously connected to the ordered FP at the transition point. We show that this continuity indicates the existence of a finite correlation-length-like quantity inside the critical phase, which diverges upon approaching the transition point.

Nogawa, Tomoaki; Hasegawa, Takehisa; Nemoto, Koji

2012-09-01

229

Evaluation of antiulcer and antisecretory potential of Linum usitatissimum fixed oil and possible mechanism of action.  

PubMed

The aim of the study was to evaluate the antiulcer activity of Linum usitatissimum fixed oil against aspirin-, indomethacin-, ethanol-, reserpine-, serotonin- and stress-induced gastric ulceration in rats and histamine-induced gastric ulceration in guinea pigs. Attempts were also made to evaluate the in vitro anticholinergic and antihistaminic activity and in vivo antisecretary and antiulcer activity of oil following pylorus ligation in rats. L. usitatissimum fixed oil exhibited significant antiulcer activity against different ulcerogens in experimental animal models. The fixed oil significantly inhibited acetylcholine- and histamine-induced contraction of guinea pig and rat ileums, respectively, suggesting its anticholinergic and antihistaminic activity. The oil also exhibited significant inhibitory effect on gastric secretion/total acidity and aspirin-induced gastric ulceration in pylorus-ligated rats. The lipoxygenase inhibitory, histamine antagonistic and antisecretory (anticholinergic) effects of the oil could probably have contributed towards antiulcer activity. L. usitatissimum fixed oil may be considered to be a drug of natural origin which possesses significant antiulcer activity. The present observation is the first experimental data showing antiulcer activity of L. usitatissimum fixed oil. PMID:20405222

Kaithwas, Gaurav; Majumdar, Dipak K

2010-04-20

230

Investigations on Two Co-C Fixed-Point Cells Prepared at INRIM and LNE-Cnam  

NASA Astrophysics Data System (ADS)

INRIM and LNE-Cnam agreed to undertake a collaboration aimed to verify, through the use of metal-carbon eutectic fixed-point cells, methods and facilities used for defining the transition temperature of eutectic fixed points and manufacturing procedures of cells. To this purpose and as a first step of the cooperation, a Co-C cell manufactured at LNE-Cnam was measured at INRIM and compared with a local cell. The two cells were of different designs: the INRIM cell of 10 cm3 inner volume and the LNE-Cnam one of 3.9 cm3. The external dimensions of the two cells were noticeably different, namely, 40 mm in length and 24 mm in diameter for the LNE-Cnam cell 3Co4 and 110 mm in length and 42 mm in diameter for the INRIM cell. Consequently, the investigation of the effect of temperature distributions in the heating furnace was undertaken by implementing the cells inside single-zone and three-zone furnaces. The transition temperature of the cell was determined at the two institutes making use of different techniques: at INRIM radiation scales at 900 nm, 950 nm, and 1.6 ?m were realized from In to Cu and then used to define T 90(Co-C) by extrapolation. At LNE-Cnam, a radiance comparator based on a grating monochromator was used for the extrapolation from the Cu fixed point. This paper presents a comparative description of the cells and the manufacturing methods and the results in terms of equivalence between the two cells and melting temperatures determined at INRIM and LNE-Cnam.

Battuello, M.; Florio, M.; Sadli, M.; Bourson, F.

2011-08-01

231

Control of transient chaos in tent maps near crisis.??I.??Fixed point targeting  

Microsoft Academic Search

Combinatorial techniques are applied to the symbolic dynamics representing tran- sient chaotic behaviour in tent maps in order to solve the problem of OGY control to the non-trivial xed point occurring in such maps. This approach allows 'pre-image overlap' to be treated exactly. Closed forms for both the probability of control being achieved and the average number of iterations to

D. K. Arrowsmith

2000-01-01

232

Computing the Least Fix-point Semantics of Denite Logic Programs Using BDDs  

Microsoft Academic Search

We present the semantic foundations for computing the least x-point semantics of denite logic programs using only standard operations over boolean functions. More precisely, we propose a representation of sets of rst-order terms by boolean functions and a provably sound formulation of intersection, union, and projection (an operation similar to restriction in relational databases) using conjunction, disjunction, and existential quantication.

Thomas Jensen; Tiphaine Turpin

2009-01-01

233

COMMON FIXED POINT THEOREMS FOR MAPPINGS SATISFYING AN IMPLICIT RELATION WITHOUT DECREASING ASSUMPTION  

Microsoft Academic Search

The authors prove common flxed point theorems in metric spaces for four mappings satisfying an implicit relation, without decreasing as- sumption, using the concept of weak compatibility. These generalize two theorems of V. Popa, a theorem of M. Imdad, S. Kumar and M. S. Khan, a theorem of H. Bouhadjera and a theorem of A. Djoudi and A. Aliouche, respectively.

Abdelkrim Aliouche; Ahcene Djoudi

2007-01-01

234

Accélération avec des conditions de transpiration d'un algorithme de point fixe en interaction fluide structure  

NASA Astrophysics Data System (ADS)

In this work, we address the numerical solution of some non-linear problems arising in the time discretization of fluid-structure interaction problems with fully implicit schemes. At each time step, we have to solve a highly non-linear coupled system, since the fluid domain depends on the unknown displacement of the structure. We propose a modified fixed-point algorithm which combines the Block-Gauss-Seidel iterations with a transpiration formulation. Numerical experiments show the great improvement in computing time with respect to the standard method. To cite this article: S. Deparis et al., C. R. Mecanique 331 (2003).

Deparis, Simone; Fernández, Miguel Ángel; Formaggia, Luca; Nobile, Fabio

2003-08-01

235

Fixed-point theorems for a controlled withdrawal of the convexity of the values of a set-valued map  

SciTech Connect

The question of the extent of the possible weakening of the convexity condition for the values of set-valued maps in the classical fixed-point theorems of Kakutani, Bohnenblust-Karlin, and Gliksberg is discussed. For an answer, one associates with each closed subset P of a Banach space a numerical function {alpha}{sub P}:(0,{infinity}){yields}[0,{infinity}), which is called the function of non-convexity of P. The closer {alpha}{sub P} is to zero, the 'more convex' is P. The equality {alpha}{sub P}{identical_to}0 is equivalent to the convexity of P. Results on selections, approximations, and fixed points for set-valued maps F of finite- and infinite-dimensional paracompact sets are established in which the equality {alpha}{sub F(x)}{identical_to}0 is replaced by conditions of the kind: {sup {alpha}}{sub F(x)} is less than 1{sup .} Several formalizations of the last condition are compared and the topological stability of constraints of this type is shown.

Semenov, P V [Moscow Pedagogical University, Moscow (Russian Federation)

1998-04-30

236

Audio video based fast fixed-point independent vector analysis for multisource separation in a room environment  

NASA Astrophysics Data System (ADS)

Fast fixed-point independent vector analysis (FastIVA) is an improved independent vector analysis (IVA) method, which can achieve faster and better separation performance than original IVA. As an example IVA method, it is designed to solve the permutation problem in frequency domain independent component analysis by retaining the higher order statistical dependency between frequencies during learning. However, the performance of all IVA methods is limited due to the dimensionality of the parameter space commonly encountered in practical frequency-domain source separation problems and the spherical symmetry assumed with the source model. In this article, a particular permutation problem encountered in using the FastIVA algorithm is highlighted, namely the block permutation problem. Therefore a new audio video based fast fixed-point independent vector analysis algorithm is proposed, which uses video information to provide a smart initialization for the optimization problem. The method cannot only avoid the ill convergence resulting from the block permutation problem but also improve the separation performance even in noisy and high reverberant environments. Different multisource datasets including the real audio video corpus AV16.3 are used to verify the proposed method. For the evaluation of the separation performance on real room recordings, a new pitch based evaluation criterion is also proposed.

Liang, Yanfeng; Naqvi, Syed Mohsen; Chambers, Jonathon A.

2012-12-01

237

Corrective Action Decision Document for Corrective Action Unit 516: Septic Systems and Discharge Points, Nevada Test Site, Nevada: Revision 1  

SciTech Connect

This Corrective Action Decision Document (CADD) identifies and rationalizes the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office's selection of a recommended corrective action alternative appropriate to facilitate the closure of Corrective Action Unit (CAU) 516: Septic Systems and Discharge Points, Nevada Test Site (NTS), Nevada, under the Federal Facility Agreement and Consent Order. Located in Areas 3, 6, and 22 on the NTS, CAU 516 includes six Corrective Action Sites (CASs) consisting of two septic systems, a sump and piping, a clean-out box and piping, dry wells, and a vehicle decontamination area. Corrective action investigation activities were performed from July 22 through August 14, 2003, with supplemental sampling conducted in late 2003 and early 2004. The potential exposure pathways for any contaminants of concern (COCs) identified during the development of the DQOs at CAU 516 gave rise to the following objectives: (1) prevent or mitigate exposure to media containing COCs at concentrations exceeding PALs as defined in the corrective action investigation plan; and (2) prevent the spread of COCs beyond each CAS. The following alternatives have been developed for consideration at CAU 516: Alternative 1 - No Further Action; Alternative 2 - Clean Closure; and Alternative 3 - Closure in Place with Administrative Controls. Alternative 1, No Further Action, is the preferred corrective action for two CASs (06-51-02 and 22-19-04). Alternative 2, Clean Closure, is the preferred corrective action for four CASs (03-59-01, 03-59-02, 06-51-01, and 06-51-03). The selected alternatives were judged to meet all requirements for the technical components evaluated, as well as meeting all applicable state and federal regulations for closure of the site and will further eliminate the contaminated media at CAU 516.

U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office

2004-04-28

238

Thermal Characteristics of the NIST Fixed-Point Cells, Furnaces, and Maintenance Baths Over the Temperature Range from 83.8058 K to 1234.93K.  

National Technical Information Service (NTIS)

The optimal realization of an International Temperature Scale of 1990 (ITS-90) defining fixed-point temperature, for an accurate calibration of a (high-temperature) standard platinum resistance thermometer ((HT)SPRT), critically depends on the thermal cha...

G. F. Strouse G. T. Furukawa

2008-01-01

239

Numerical Modeling of Heat Flux in Fixed-Point Cells Due to the Hydrostatic-Head Effect  

NASA Astrophysics Data System (ADS)

The article presents the numerical analysis of a particular thermal effect, which occurs during the calibration of standard platinum resistance thermometers in fixed-point cells. The temperature within the fixed-point cell varies linearly with the immersion depth due to the hydrostatic-head effect, so a quasi-linear temperature gradient in the vertical direction is inherently present. If there is a temperature gradient, a resulting heat flux will appear. This heat flux flows across the thermal conductivities, which change with depth, so the resulting temperature field is distorted. The key issue that is tackled in this article is the magnitude of these temperature deviations and their influence on the measurement accuracy. This effect should not be confused with the perturbing heat exchange toward the thermal enclosure and ambient. These are independent effects that are in real systems superimposed on each other. To get a better insight into this phenomenon, a numerical model based on a finite-difference method was developed. The model allows the simulation of the measurement of the thermometer immersion profile and of the use of different bushings, as two of the methods for assessing the thermal effects. The results of the modeling showed that there is an inherent difference between the temperature measured by the thermometer sensor and the temperature at the point of the phase transition, even if the immersion depth was infinite and there was no perturbing heat exchange toward the thermal enclosure and ambient. Nevertheless, in several cases the thermometer would still almost perfectly follow the immersion-profile curve. The only exception is near the bottom of the cell, where a small deviation from the immersion profile was observed. This is in agreement with previously presented experimental results, where this behavior was noticed, but never satisfactorily explained.

Batagelj, V.; Bojkovski, J.; Drnovšek, J.

2011-12-01

240

Newton-Raphson method and fixed-point technique in finite element computation of magnetic field problems in media with hysteresis  

Microsoft Academic Search

A comparison between the Newton-Raphson method and the fixed-point technique in hysteretic magnetic field problems is presented. Four different approaches are studied and contrast between them in terms of the convergence rate and computation time consumption is highlighted. The Newton-Raphson-based approaches are found better than the iteration schemes associated with the fixed-point technique for a model problem

Jlilius Saitz

1999-01-01

241

Corrective Action Decision Document for Corrective Action Unit 423: Building 03-60 Underground Discharge Point, Tonopah Test Range, Nevada  

SciTech Connect

This Corrective Action Decision Document (CADD) has been prepared for Corrective Action Unit (CAU) 423, Building 03-60 Underground Discharge Point (UDP) in accordance with the Federal Facility Agreement and Consent Order (FFACO) of 1996 that was agreed to by the US Department of Energy, Nevada Operations Office (DOE/NV); the Nevada Division of Environmental Protection (NDEP); and the U.S Department of Defense (FFACO, 1996). The CADD provides or references the specific information necessary to recommend a preferred corrective action for the single Corrective Action Site (CAS), 03-02-002-0308, within CAU 423. Corrective Action Unit 423 is located at the Tonopah Test Range (TTR), Nevada. The TTR is approximately 255 kilometers (km) (140 miles[mi]) northwest of Las Vegas, Nevada. The UDP is approximately 73 meters (m) (240 feet [ft]) northwest of the northwest corner of Building 03-60, the Auto Maintenance Shop. Corrective Action Unit 423 is comprised of the UDP and an associated discharge line extending from Building 03-60. The UDP received waste oil products from the Auto Maintenance Shop, a light-duty fleet maintenance shop in the Area 3 compound, from 1965 to 1989 or 1990 (DOE/NV, 1997).

DOE /NV

1999-06-19

242

Humans Anticipate the Goal of other People's Point-Light Actions  

PubMed Central

This eye tracking study investigated the degree to which biological motion information from manual point-light displays provides sufficient information to elicit anticipatory eye movements. We compared gaze performance of adults observing a biological motion point-light display of a hand reaching for a goal object or a non-biological version of the same event. Participants anticipated the goal of the point-light action in the biological motion condition but not in a non-biological control condition. The present study demonstrates that kinematic information from biological motion can be used to anticipate the goal of other people’s point-light actions and that the presence of biological motion is sufficient for anticipation to occur.

Elsner, Claudia; Falck-Ytter, Terje; Gredeback, Gustaf

2012-01-01

243

CORRECTIVE ACTION PLAN FOR CORRECTIVE ACTION UNIT 516: SEPTIC SYSTEMS AND DISCHARGE POINTS, NEVADA TEST SITE, NEVADA  

SciTech Connect

Corrective Action Unit (CAU) 516, Septic Systems and Discharge Points, is listed in the ''Federal Facility Agreement and Consent Order'' (FFACO) of 1996 (FFACO, 1996). CAU 516 consists of six Corrective Action Sites (CASs) located in Areas 3, 6, and 22 of the Nevada Test Site (NTS), which is located approximately 65 miles northwest of Las Vegas, Nevada (Figure 1). CAU 516 is comprised of the following six CASs: (1) 03-59-01 Building 3C-36 Septic System; (2) 03-59-02 Building 3C-45 Septic System; (3) 06-51-01 Sump and Piping; (4) 06-51-02 Clay Pipe and Debris; (5) 06-51-03 Clean-Out Box and Piping; and (6) 22-19-04 Vehicle Decontamination Area. Details on site history and site characterization results for CAU 516 are provided in the approved Corrective Action Investigation Plan (CAIP), (U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office [NNSA/NSO], 2003), and the approved Corrective Action Decision Document (CADD) (NNSA/NSO, 2004).

BECHTEL NEVADA; U.S. DEPARTMENT OF ENERGY, NATIONAL NUCLEAR SECURITY ADMINISTRATION NEVADA SITE OFFICE

2005-08-01

244

A study of the stability of the pendulum-like oscillations of a heavy rigid body with a single fixed point  

NASA Astrophysics Data System (ADS)

The stability of the plane-parallel oscillations of a heavy rigid body with a single fixed point are analyzed without the assumption of a sufficiently large distance between the fixed point and the center of mass of the body. In particular, it is shown that, for the simplest friction law, the oscillations of the body are asymptotically stable if, among the main moments of inertia of the body, A, B, and C, relative to the fixed point, the moment A relative to the oscillation axis is the greatest. The nonasymptotic stability of the plane-parallel of oscillations of the body in the absence of friction is investigated for the case where the moment of inertia A is arbitrary and moments B and C are equal.

Ishlinskii, A. Iu.; Storozhenko, V. A.; Temchenko, M. E.

1986-02-01

245

Asymptotically free four-Fermi theory in 4 dimensions at the z=3 Lifshitz-like fixed point  

SciTech Connect

We show that a Nambu-Jona-Lasinio type four-fermion coupling at the z=3 Lifshitz-like fixed point in 3+1 dimensions is asymptotically free and generates a mass scale dynamically. This result is nonperturbative in the limit of a large number of fermion species. The theory is ultraviolet complete and at low energies exhibits Lorentz invariance as an emergent spacetime symmetry. Many of our results generalize to z=d in odd d spatial dimensions; z=d=1 corresponds to the Gross-Neveu model. The above mechanism of mass generation has potential applications to the fermion mass problem and to dynamical electroweak symmetry breaking. We present a scenario in which a composite Higgs field arises from a condensate of these fermions, which then couples to quarks and leptons of the standard model. Such a scenario could eliminate the need for the Higgs potential and the associated hierarchy problem. We also show that the axial anomaly formula at z=3 coincides with the usual one in the relativistic domain.

Dhar, Avinash; Mandal, Gautam [Department of Theoretical Physics, Tata Institute of Fundamental Research, Mumbai 400 005 (India); Wadia, Spenta R. [Department of Theoretical Physics, Tata Institute of Fundamental Research, Mumbai 400 005 (India); International Centre for Theoretical Sciences, Tata Institute of Fundamental Research, Mumbai 400 005 (India)

2009-11-15

246

New Method of Filling of High-Temperature Fixed-Point Cells Based on Metal-Carbon Eutectics/Peritectics  

NASA Astrophysics Data System (ADS)

A new method of filling of high-temperature fixed-point cells based on metal-carbon eutectics and peritectics is suggested and tested. In this method a metal and carbon powder mixture is introduced not directly into the crucible, but into an additional container located just above the crucible. The mixture melts inside the container, and the already molten eutectic drops through a small hole in the bottom of the container and fills the crucible drop by drop. The method can be used to obtain a uniform ingot without porous or foundry cavities, to minimize the risk of contamination, and to avoid some other disadvantages. The method was applied to fabricate Re-C and WC-C cells using 5N purity materials. The cells demonstrated a good plateau shape with melting ranges of 0.2 K and 80 mK for Re-C and WC-C, respectively. The Re-C cell was compared with a cell built at NMIJ and showed good agreement with a difference of melting temperatures of only 45 mK.

Khlevnoy, B. B.; Grigoryeva, I. A.; Ibragimov, N. A.

2011-08-01

247

Pointing losses in single-axis and fixed-mount earth-station antennas due to satellite movement  

NASA Astrophysics Data System (ADS)

There are substantial cost advantages in the use of single-axis or fixed-mount earth-station antennas, thus reducing or eliminating the need for autotracking in earth-stations operating with quasi-stationary satellites. Such cost advantages are more relevant in small antennas where the tracking system represents a larger percentage of the overall cost. In addition, small antennas are particularly suitable to be operated without autotracking, owing to their wider half-power beamwidth. This paper describes a model for calculating the antenna pointing loss as a function of the antenna diameter, operating frequency band, satellite station-keeping tolerances, and the relative geometry between the earth-station and the satellite. The model has been extensively used in the development of Intelsat's IBS and VISTA services as well as in domestic leases. Although the model has been developed based on orbital mechanics equations, its emphasis is towards earth-station and systems engineering applications. Some example calculations and results obtained through an HP-41 CV programmable calculator are also provided.

Buchsbaum, L. M.

1986-06-01

248

CORRECTIVE ACTION DECISION DOCUMENT FOR CORRECTIVE ACTION UNIT 423: BUILDING 03-60 UNDERGROUND DISCHARGE POINT, TONOPAH TEST RANGE, NEVADA, REVISION 0, JUNE 1998  

SciTech Connect

This Corrective Action Decision Document has been prepared for the Area 3 Building 03-60 Underground Discharge Point (Corrective Action Unit 423) in accordance with the Federal Facility Agreement and Consent Order of 1996 (FFACO, 1996). Corrective Action Unit 423 is located at the Tonopah Test Range and is comprised of Corrective Action Site 03-02-002-0308. The purpose of this Corrective Action Decision Document is to identify and provide a rationale for the selection of a recommended corrective action alternative for Corrective Action Unit 423. The scope of this Correction Action Decision Document consists of the following: ? Develop corrective action objectives. ? Identify corrective action alternative screening criteria. ? Develop corrective action alternatives. ? Perform detailed and comparative evaluations of the corrective action alternatives in relation to the corrective action objectives and screening criteria. ? Recommend and justify a preferred corrective action alternative for the Corrective Action Unit. In January 1998, a corrective action investigation was performed as set forth in the Corrective Action Investigation Plan for Corrective Action Unit No. 423: Building 03-60 Underground Discharge Point, Tonopah Test Range, Nevada (DOE/NV, 1997). A hydrocarbon plume was found to emanate from near the bottom of the Underground Discharge Point to the west. The plume encompasses approximately 65 square meters (700 square feet). The highest total petroleum hydrocarbon level detected was 2,400 milligrams per kilogram. No other contaminants were detected above preliminary action levels. Details of the investigation can be found in Appendix A of this document. Based on the potential exposure pathways identified during the Data Quality Objectives process, the following corrective action objectives have been identified for Corrective Action Unit 423: ? Prevent or mitigate human exposure to subsurface soil containing contaminants of concern. ? Prevent adverse impacts to groundwater quality. Based on the review of existing data, future land use assumption, and current operations at the Tonopah Test Range, the following alternatives were developed for consideration at the Building 03-60 Underground Discharge Point: ? Alternative 1 - No Action ? Alternative 2 - Closure in Place with Administrative Controls ? Alternative 3 - Partial Excavation, Disposal, and Administrative Controls ? Alternative 4 - In Situ Bioremediation The corrective action alternatives were evaluated based on four general corrective action standards and five remedy selection decision factors. Based on the results of this evaluation, the preferred alternative for Corrective Action Unit 423 is Alternative 2, Closure in Place with Administrative Controls. The preferred corrective action alternative was evaluated on technical merit, focusing on performance, reliability, feasibility, and safety. The alternative was judged to meet all requirements for the technical components evaluated. The alternative also meets all applicable state and federal regulations for closure of the site and will reduce potential future exposure pathways to the contaminated soils.

NONE

1998-06-01

249

Post-Minkowski action for point particles and a helically symmetric binary solution  

SciTech Connect

Two Fokker actions and corresponding equations of motion are obtained for two point particles in a post-Minkowski framework, in which the field of each particle is given by the half-retarded + half-advanced solution to the linearized Einstein equations. The first action is parametrization invariant, the second a generalization of the affinely parametrized quadratic action for a relativistic particle. Expressions for a conserved 4-momentum and angular momentum tensor are obtained in terms of the particles' trajectories in this post-Minkowski approximation. A formal solution to the equations of motion is found for a binary system with circular orbits. For a bound system of this kind, the post-Minkowski solution is a toy model that omits nonlinear terms of relevant post-Newtonian order; and we also obtain a Fokker action that is accurate to first post-Newtonian order, by adding to the post-Minkowski action a term cubic in the particle masses. Curiously, the conserved energy and angular momentum associated with the Fokker action are each finite and well-defined for this bound 2-particle system despite the fact that the total energy and angular momentum of the radiation field diverge. Corresponding solutions and conserved quantities are found for two scalar charges (for electromagnetic charges we exhibit the solution found by Schild). For a broad class of parametrization-invariant Fokker actions and for the affinely parametrized action, binary systems with circular orbits satisfy the relation dE={omega}dL (a form of the first law of thermodynamics), relating the energy, angular velocity and angular momentum of nearby equilibrium configurations.

Friedman, John L. [Department of Physics, University of Wisconsin-Milwaukee, P.O. Box 413, Milwaukee, Wisconsin 53201 (United States); Uryu, Koji [Department of Physics, University of Wisconsin-Milwaukee, P.O. Box 413, Milwaukee, Wisconsin 53201 (United States); SISSA, via Beirut 4, 34014 Trieste (Italy)

2006-05-15

250

Current Work on Furnaces and Data Analysis to Improve the Uniformity and Noise Levels for Metal Fixed Points  

NASA Astrophysics Data System (ADS)

Ongoing work to improve the uniformity of vertically mounted furnaces, manufactured by Carbolite (e.g., Type TZF12/75—three-zone furnace capable of 1200 °C, with 75 mm inner bore) along the axis and across the working tube and/or equalizing block is reported. This involves adjusting the size of the end zones, the position of the control thermometers, and the use of cascade-control methods. Means regularly used at NPL to reduce electrical noise in some commercially available ac furnaces through a reduction in the voltage used to “fire” the heaters, and better use of thyristor controllers (by extending their cycle time) are described. The need to shield the controllers from local magnetic fields is described. With these measures, the electrical noise from ac furnaces can approach that of dc furnaces, without the large cost of a dc power supply. The application of new data analysis techniques (Allan deviation) will be shown to improve the representation of uninterrupted fixed-point traces (as used in ingot verification rather than PRT calibration). Reduction of statistical noise on the temperature measurements has been achieved for data on the freezing plateau by determining the statistically optimum averaging time. This shows that the statistical uncertainty in the determination of the temperature of a particular freezing plateau is less than 25 ?K and that noise (drift) from other sources, possibly due to variations in room temperature, starts to become appreciable over periods longer than a few tens of minutes. The measurement of freezing and melting plateaux at this level is aided by the introduction of new ASL-F900 bridge(s), and quieter/larger standard resistor baths.

Head, D. I.; Gray, J.; de Podesta, M.

2009-02-01

251

Application of Avery-Peterson fixed point theorem to nonlinear boundary value problem of fractional differential equation with the Caputo's derivative  

NASA Astrophysics Data System (ADS)

In this paper, by means of the Avery-Peterson fixed point theorem, we establish the existence result of at least triple positive solutions of four-point boundary value problem of nonlinear differential equation with Caputo's fractional order derivative. An example illustrating our main result is given. Our results complements previous work in the area of boundary value problems of nonlinear fractional differential equations.

Liu, Yang

2012-12-01

252

Analogies between the Torque-Free Motion of a Rigid Body about a Fixed Point and Light Propagation in Anisotropic Media  

ERIC Educational Resources Information Center

|An apparently unnoticed analogy between the torque-free motion of a rotating rigid body about a fixed point and the propagation of light in anisotropic media is stated. First, a new plane construction for visualizing this torque-free motion is proposed. This method uses an intrinsic representation alternative to angular momentum and independent…

Bellver-Cebreros, Consuelo; Rodriguez-Danta, Marcelo

2009-01-01

253

Closure Report for Corrective Action Unit 516: Septic Systems and Discharge Points  

SciTech Connect

Corrective Action Unit (CAU) 516 is located in Areas 3, 6, and 22 of the Nevada Test Site. CAU 516 is listed in the Federal Facility Agreement and Consent Order of 1996 as Septic Systems and Discharge Points, and is comprised of six Corrective Action Sites (CASs): {sm_bullet} CAS 03-59-01, Bldg 3C-36 Septic System {sm_bullet} CAS 03-59-02, Bldg 3C-45 Septic System {sm_bullet} CAS 06-51-01, Sump and Piping {sm_bullet} CAS 06-51-02, Clay Pipe and Debris {sm_bullet} CAS 06-51-03, Clean Out Box and Piping {sm_bullet} CAS 22-19-04, Vehicle Decontamination Area The Nevada Division of Environmental Protection (NDEP)-approved corrective action alternative for CASs 06-51-02 and 22-19-04 is no further action. The NDEP-approved corrective action alternative for CASs 03-59-01, 03-59-02, 06-51-01, and 06-51-03 is clean closure. Closure activities included removing and disposing of total petroleum hydrocarbon (TPH)-impacted septic tank contents, septic tanks, distribution/clean out boxes, and piping. CAU 516 was closed in accordance with the NDEP-approved CAU 516 Corrective Action Plan (CAP). The closure activities specified in the CAP were based on the recommendations presented in the CAU 516 Corrective Action Decision Document (U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office, 2004). This Closure Report documents CAU 516 closure activities. During closure activities, approximately 186 tons of hydrocarbon waste in the form of TPH-impacted soil and debris, as well as 89 tons of construction debris, were generated and managed and disposed of appropriately. Waste minimization techniques, such as field screening of soil samples and the utilization of laboratory analysis to characterize and classify waste streams, were employed during the performance of closure work.

NSTec Environmental Restoration

2007-02-01

254

Spectral and Total Effective Emissivity of a High-Temperature Fixed-Point Radiator Considered in Relation to the Temperature Drop Across its Back Wall  

NASA Astrophysics Data System (ADS)

In this article, calculations of the spectral and total cavity emissivity of a high-temperature fixed-point radiator by means of the Monte Carlo technique in conjunction with calculations of the temperature drop across its back wall using the finite-element approach are presented. The temperature drop across the back wall of a fixed-point cavity radiator is influenced by the heat exchange within the cavity and between the cavity and the front end of the associated furnace. The special effects of these influences were virtually neglected in earlier estimates of the temperature drop for high-temperature fixed-point radiators, resulting in an overestimation of the value of this parameter. These same effects have a non-negligible influence on the cavity emissivity. Even though the heat exchange between the furnace and cavity enhances the temperature uniformity within the cavity, it appears that the cavity cannot be assumed to be isothermal for the case considered, as is usually taken for granted when dealing with fixed-point cavity radiators. Since the temperature drop and total emissivity are affected by the same thermophysical processes, there exists a correlation between these parameters, which might find practical application. To provide experimental evidence to the findings inferred from the calculations, results of measurements of the cavity radiance-temperature of two high-temperature fixed-point cells are presented, enclosing an ingot of eutectic Re-C, for which the cavities are provided with different apertures. For ? = 650 nm, the measured differences in cavity radiance-temperature are shown to be compatible with the differences in radiance temperature calculated for these cavities.

Bloembergen, P.; Khlevnoy, B. B.; Jimeno Largo, P.; Yamada, Y.

2008-02-01

255

Modification and fixed-point analysis of a Kalman filter for orientation estimation based on 9D inertial measurement unit data.  

PubMed

A common approach for high accuracy sensor fusion based on 9D inertial measurement unit data is Kalman filtering. State of the art floating-point filter algorithms differ in their computational complexity nevertheless, real-time operation on a low-power microcontroller at high sampling rates is not possible. This work presents algorithmic modifications to reduce the computational demands of a two-step minimum order Kalman filter. Furthermore, the required bit-width of a fixed-point filter version is explored. For evaluation real-world data captured using an Xsens MTx inertial sensor is used. Changes in computational latency and orientation estimation accuracy due to the proposed algorithmic modifications and fixed-point number representation are evaluated in detail on a variety of processing platforms enabling on-board processing on wearable sensor platforms. PMID:24110597

Bruckner, Hans-Peter; Spindeldreier, Christian; Blume, Holger

2013-07-01

256

Post-Minkowski action for point-particles and a helically symmetric binary solution  

NASA Astrophysics Data System (ADS)

A Fokker action and equations of motion are obtained for two point particles in a post-Minkowski framework, in which the field of each particle is given by the half-retarded + half- advanced solution to the linearized Einstein equations. Expressions for the conserved four-momentum and the angular momentum tensor are obtained in terms of the particles' trajectories in this post-Minkowski approximation. A formal solution to the equations of motion is found for a binary system with circular orbits, the analog of a solution found independently by Schonberg and by Schild in the electromagnetic case. For a bound system of this kind, the post-Minkowski solution is a toy model that omits nonlinear terms of relevant post-Newtonian order; by adding to the action a post-Newtonian correction term, one obtains an innermost stable circular orbit.

Friedman, John; Uryu, Koji

2005-04-01

257

Integrating Biological Motion: The Role of Grouping in the Perception of Point-Light Actions  

PubMed Central

The human visual system is highly sensitive to biological motion and manages to organize even a highly reduced point-light stimulus into a vivid percept of human action. The current study investigated to what extent the origin of this saliency of point-light displays is related to its intrinsic Gestalt qualities. In particular, we studied whether biological motion perception is facilitated when the elements can be grouped according to good continuation and similarity as Gestalt principles of perceptual organization. We found that both grouping principles enhanced biological motion perception but their effects differed when stimuli were inverted. These results provide evidence that Gestalt principles of good continuity and similarity also apply to more complex and dynamic meaningful stimuli.

Poljac, Ervin; Verfaillie, Karl; Wagemans, Johan

2011-01-01

258

First measurement using three-in-one cell: a new design of the fixed-point cell for the calibration of thermometers  

NASA Astrophysics Data System (ADS)

A new design of the fixed-point cell that contains multiple metal elements in a single crucible has been introduced for fixed-point calibration of secondary thermometers such as thermocouples. A multicell with aluminium, silver and copper was fabricated and used for the calibration of a Pt/Pd thermocouple. The expanded uncertainties (k = 2) of the realization of the multicell were 0.07 °C, 0.12 °C and 0.24 °C, plus an additional term from the inhomogeneity of the thermocouple, for aluminium, silver and copper, respectively. These uncertainties are considerably smaller than those obtained from the method of calibration by comparison in similar temperature ranges. This proves the suitability of the metal multicells for the calibration of secondary thermometers.

Kim, Yong-Gyoo; Gam, Kee Sool; Yang, Inseok

2008-06-01

259

Application of interim fixed reference points to maintain the occlusal vertical dimension: a technique for immediate loading protocols in the edentulous mandible.  

PubMed

This article describes a technique for the clinical insertion and use of specially designed screws as fixed intraoral reference and attachment points in implant dentistry. After insertion, these screws serve to stabilize radiographic and surgical templates in the completely edentulous patient. This approach provides the advantage of guiding maintenance of the correct occlusal vertical dimension and ensuring accuracy and stability during subsequent phases of treatment. PMID:16911891

Holst, Stefan; Blatz, Markus B; Bergler, Michael; Wichmann, Manfred

2006-08-01

260

A 231MHz, 2.18mW 32-bit Logarithmic Arithmetic Unit for Fixed-Point 3-D Graphics System  

Microsoft Academic Search

A 32-bit fixed-point logarithmic arithmetic unit is proposed for the possible application to mobile three-dimensional (3-D) graphics system. The proposed logarithmic arithmetic unit performs division, reciprocal, square-root, reciprocal-square-root and square operations in two clock cycles and powering operation in four clock cycles. It can program its number range for accurate computation flexibility of 3-D graphics pipeline and eight -region piecewise

Hyejung Kim; Byeong-Gyu Nam; Ju-Ho Sohn; Jeong-Ho Woo; Hoi-Jun Yoo

2006-01-01

261

Event-Related Potentials to Point-Light Displays of Human Actions in 5-month-old Infants  

Microsoft Academic Search

Five-month-old infants viewed point-light displays depicting the human actions of walking, kicking, throwing, and running. These actions were presented as upright canonical displays and spatially scrambled displays in which the global form of the action was disrupted. Significant differences were observed between event-related potential (ERP) waveforms to the canonical and scrambled displays at mid-parietal, lateral parietal, temporal, and occipital electrode

Peter J. Marshall; Thomas F. Shipley

2009-01-01

262

Point Estimation Techniques in Psychological Research: Studies on the Role of Meaning in Self-Determined Action.  

ERIC Educational Resources Information Center

|Demonstrates how, by adopting active agent model of humans and several associated research methodologies, one can conduct research using point estimation. Presents two studies that establish link between meaningfulness of action and subject's ability to self-determine actions in that domain. Agentic models are shown to greatly enhance explanatory…

Howard, George S.; And Others

1991-01-01

263

A Narrative of an Action Research Study in Preschool: Choice Points and Their Implications for Professional and Organisational Development  

ERIC Educational Resources Information Center

|Against the background of Swedish preschool's historical and traditional functions in Swedish society, this article focuses on some of the choice points and their implications for professional and organisational development in preschool. By combining feminist pragmatism and feminist action research, some analytical points are made regarding the…

Gillberg, Claudia

2011-01-01

264

Point Estimation Techniques in Psychological Research: Studies on the Role of Meaning in Self-Determined Action  

Microsoft Academic Search

Meehl (1978, 1990a, 1990b) and others have called for point estimation techniques to be used in psychological research. This article demonstrates how, by adopting an active agent model of humans and several associated research methodologies, one can easily conduct research using point estimation with great success. Two studies are presented that establish a link between the meaningfulness of an action

George S. Howard; Thomas D. Curtin; Andy J. Johnson

1991-01-01

265

Patterns of hypermetria and terminal cocontraction during point-to-point movements demonstrate independent action of trajectory and postural controllers  

PubMed Central

We examined elbow muscle activities and movement kinematics to determine how subjects combine elementary control actions in performing movements with one and two trajectory segments. In reaching, subjects made a rapid elbow flexion to a visual target before stabilizing the limb with either a low or a higher level of elbow flexor/extensor coactivity (CoA), which was cued by target diameter. Cursor diameter provided real-time biofeedback of actual muscle CoA. In reversing, the limb was to reverse direction within the target and return to the origin with minimal CoA. We previously reported that subjects overshoot the goal when attempting a reversal after first having learned to reach accurately to the same target. Here we test the hypothesis that this hypermetria results because reversals co-opt the initial feedforward control action from the preceding trained reach, thereby failing to account for task-dependent changes in limb impedance induced by differences in flexor/extensor coactivity as the target is acquired (higher in reaching than reversing). Instructed increases in elbow CoA began mid-reach, thus increasing elbow impedance and reducing transient oscillations present in low CoA movments. Flexor EMG alone increased at movement onset. Test reversals incorporated the initial agonist activity of previous reaches but not the increased coactivity at the target, thus leading to overshoot. Moreover, we observed elevated coactivity in reversals upon returning to the origin even though coactivity in reaching was centered at the goal target. These findings refute the idea that the brain necessarily invokes distinct unitary control actions for reaches and reversals made to the same target. Instead, reaches and reversals share a common control action that initiates trajectories toward their target and another later control action that terminates movement and stabilizes the limb about its final resting posture, which differs in the two tasks.

Ghez, Claude; Asnani, Supriya

2011-01-01

266

Corrective Action Investigation Plan for Corrective Action Unit 516: Septic Systems and Discharge Points, Nevada Test Site, Nevada, Rev. 0, Including Record of Technical Change No. 1  

SciTech Connect

This Corrective Action Investigation Plan (CAIP) contains the U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Sites Office's (NNSA/NSO's) approach to collect the data necessary to evaluate corrective action alternatives appropriate for the closure of Corrective Action Unit (CAU) 516, Septic Systems and Discharge Points, Nevada Test Site (NTS), Nevada, under the Federal Facility Agreement and Consent Order. CAU 516 consists of six Corrective Action Sites: 03-59-01, Building 3C-36 Septic System; 03-59-02, Building 3C-45 Septic System; 06-51-01, Sump Piping, 06-51-02, Clay Pipe and Debris; 06-51-03, Clean Out Box and Piping; and 22-19-04, Vehicle Decontamination Area. Located in Areas 3, 6, and 22 of the NTS, CAU 516 is being investigated because disposed waste may be present without appropriate controls, and hazardous and/or radioactive constituents may be present or migrating at concentrations and locations that could potentially pose a threat to human health and the environment. Existing information and process knowledge on the expected nature and extent of contamination of CAU 516 are insufficient to select preferred corrective action alternatives; therefore, additional information will be obtained by conducting a corrective action investigation. The results of this field investigation will support a defensible evaluation of corrective action alternatives in the corrective action decision document. Record of Technical Change No. 1 is dated 3/2004.

U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Sites Office

2003-04-28

267

Corrective Action Decision Document for Corrective Action Unit 516: Septic Systems and Discharge Points, Nevada Test Site, Nevada, Rev. No.: 1 with ROTC 1  

SciTech Connect

This Corrective Action Decision Document (CADD) has been prepared for Corrective Action Unit (CAU) 516, Septic Systems and Discharge Points, Nevada Test Site, Nevada, in accordance with the ''Federal Facility Agreement and Consent Order'' (1996). Corrective Action Unit 516 is comprised of the following Corrective Action Sites (CASs): (1) 03-59-01 - Bldg 3C-36 Septic System; (2) 03-59-02 - Bldg 3C-45 Septic System; (3) 06-51-01 - Sump and Piping; (4) 06-51-02 - Clay Pipe and Debris; (5) 06-51-03 - Clean Out Box and Piping; and (7) 22-19-04 - Vehicle Decontamination Area. The purpose of this CADD is to identify and provide the rationale for the recommendation of an acceptable corrective action alternative for each CAS within CAU 516. Corrective action investigation activities were performed between July 22 and August 14, 2003, as set forth in the Corrective Action Investigation Plan. Supplemental sampling was conducted in late 2003 and early 2004.

Alfred N. Wickline

2004-04-01

268

A Mid-IR Pyrometer Calibrated with High-Temperature Fixed Points for Improved Scale Realization to 2,500°C  

NASA Astrophysics Data System (ADS)

Glass surface temperature can be measured using a radiation thermometer operating at a mid-IR wavelength, typically the 3 5 ?m band, where the glass is opaque. For optical fiber preforms, the temperature measurement requirement may exceed 2,200°C. Scale realization at national measurement institutes at these temperatures is usually carried out at short wavelengths, typically less than 1 ?m. The mismatch in wavelength can lead to significant uncertainties when calibrating a radiation thermometer working at 3 5 ?m. To overcome this, a narrow band 3.95 ?m radiation thermometer has been built that is designed to be used from 1,000 to 2,500°C. It is calibrated by measurement of high-temperature metal carbon eutectic fixed-points. The instrument is based on silicon lenses, with a liquid nitrogen (LN2)-cooled InSb detector, and narrow-band interference filter. An anti-reflection coated objective lens/aperture stop focuses onto a field stop giving a 1 mm target, then a collimating lens, and glare stop. All parts visible to the detector, other than the target area, are either at LN2 temperature or are part of a temperature-stabilized housing. A relay-operated shutter that blocks the field stop is used to subtract the background. The size-of-source effect of the instrument has been measured. Gold-point measurements have been made to assess the stability. The device has been calibrated using high-temperature fixed points. A three-parameter fit has been applied and the resultant scale compared to an ITS-90 realization.

Lowe, David; McEvoy, H. C.; Owen, M.

2007-12-01

269

Corrective Action Plan for Corrective Action Unit 423: Area 3 Building 03-60 Underground Discharge Point, Tonopah Test Range, Nevada  

SciTech Connect

The Corrective Action Plan provides the closure methods for Corrective Action Unit (CAU) 423: Area 3 Building 03-60 Underground Discharge Point (UDP), Tonoopah Test Range, Nevada. CAU 423 consists of the UDP and an associated discharge pipeline extending from Building 03-60. Corrective action investigations were completed in January 1998, and are documented in the Corrective Action Decision Document (US DOE, 1998). Results indicate an asymmetrical hydrocarbon plume, measuring 11 meters (m) 35 ft in length, 6 m (20 ft) in width, and 4 to 20 m (14 to 65 ft) in depth, has formed beneath the UDP and migrated westward. Petroleum hydrocarbon levels were identified above the 100 miligrams per kilogram (mg/kg) action level specified in Nevada Administrative Code (NAC) 445A (NAC 1996). The highest petroleum hydrocarbon concentration detected was 2,4000 mg/kg at 6 m, 20 ft, below surface grade as diesel. Corrective actions will consist of administrative controls and in place closure of th e UDP and its associated discharge pipeline.

Bechtel Nevada

1998-10-31

270

Addendum to the Corrective Action Decision Document\\/Closure Report for Corrective Action Unit 406: Area 3 Building 03-74 & Building 03-58 Underground Discharge Points and Corrective Action Unit 429: Area 3 Building 03-55 & Area 9 Building 09-52 Underground Discharge Points, Tonopah Test Range, Nevada, Revision 0  

Microsoft Academic Search

This document constitutes an addendum to the March 2000, Corrective Action Decision Document \\/ Closure Report for Corrective Action Unit 406: Area 3 Building 03-74 & 03-58 Underground Discharge Points and Corrective Action Unit 429: Area 3 Building 03-55 & Area 9 Building 09-52 Underground Discharge Points (TTR) as described in the document Recommendations and Justifications for Modifications for Use

Lynn Kidman

2008-01-01

271

Corrective Action Decision Document/ Closure Report for Corrective Action Unit 556: Dry Wells and Surface Release Points, Nevada Test Site, Nevada with Errata Sheet, Revision 0  

SciTech Connect

This Corrective Action Decision Document (CADD)/Closure Report (CR) has been prepared for Corrective Action Unit 556, Dry Wells and Surface Release Points, located at the Nevada Test Site, Nevada, in accordance with the Federal Facility Agreement and Consent Order (FFACO, 1996; as amended February 2008). Corrective Action Unit (CAU) 556 is comprised of four corrective action sites (CASs): • 06-20-04, National Cementers Dry Well • 06-99-09, Birdwell Test Hole • 25-60-03, E-MAD Stormwater Discharge and Piping • 25-64-01, Vehicle Washdown and Drainage Pit The purpose of this CADD/CR is to provide justification and documentation supporting the recommendation for closure of CAU 556 with no further corrective action. To achieve this, corrective action investigation (CAI) activities began on February 7 and were completed on June 19, 2008, as set forth in the Corrective Action Investigation Plan for Corrective Action Unit 556: Dry Wells and Surface Release Points, Nevada Test Site, Nevada (NNSA/NSO, 2007). The purpose of the CAI was to fulfill the following data needs as defined during the data quality objective (DQO) process: • Determine whether contaminants of concern (COCs) are present. • If COCs are present, determine their nature and extent. • Provide sufficient information and data to complete appropriate corrective actions. The CAU 556 data were evaluated based on the data quality assessment process, which demonstrated the quality and acceptability of the data for use in fulfilling the DQO data needs. Analytes detected during the CAI were evaluated against appropriate final action levels (FALs) to identify the COCs for each CAS. The results of the CAI identified COCs at one of the four CASs in CAU 556 that required the completion of a corrective action. Assessment of the data generated from investigation activities conducted at CAU 556 revealed the following: • Corrective Action Sites 06-20-04, 06-99-09, and 25-64-01 do not contain contamination at concentrations exceeding the FALs. • Polychlorinated biphenyl (PCB) contamination above the FAL was identified in the surface and/or shallow subsurface soils at the outfall and around Catch Basin 2, and in soils contained within the catch basins and the manhole at CAS 25-60-03. A corrective action of close in place with a soil removal action and use restriction (UR) was completed at CAS 25-60-03. The PCB-contaminated soils were removed from the outfall area and around Catch Basin 2, and disposed of at a Nevada Test Site landfill as part of a removal action. The catch basins and the manhole were sealed shut by filling them with grout. The end of the outfall pipe was plugged using grout, covered with soil, and the area was regraded. A UR was applied to the entire stormwater system at CAS 25-60-03, which includes the three catch basins, manhole, and associated piping. No further action is the corrective action for CASs 06-20-04, 06-99-09, and 25-64-01. The liquids in the test holes at CAS 06-99-09 were removed for disposal and the features were filled with grout as a best management practice. The drainage pipe between the vehicle washdown pad and the drainage pit at CAS 25-64-01 was sealed at each end as a best management practice. The corrective actions were evaluated on technical merit focusing on performance, reliability, feasibility, safety, and cost. They were judged to meet all requirements for the technical components evaluated. The corrective actions meet all applicable federal and state regulations for closure of the site and will reduce potential exposure pathways to the contaminated media to an acceptable level at CAU 556. Therefore, the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office provides the following recommendations: • Maintain a UR for the entire stormwater drainage system (i.e., three catch basins, one manhole, and associated piping) at CAS 25-60-03. • No further corrective action for CAU 556. • A Notice of Completion to the U.S. Department of Energy, National Nuclear Security Administration Nevada

Grant Evenson

2008-09-01

272

Decision points in child welfare: An action research model to address disproportionality  

Microsoft Academic Search

Researchers conduct secondary analysis of data collected in community-based focus groups convened to analyze key decision points where racial disproportionality grew wider in child welfare. Analysis confirms findings of other research pointing to referral bias, unclear or problematic policies related to engaging kin, the confounding role of poverty, and racial disparities in the availability of services to ameliorate family problems.

Marian S. Harris; Wanda Hackett

2008-01-01

273

Medial-point description of shape: a representation for action coding and its psychophysical correlates.  

PubMed

We describe a region-based shape representation that might be particularly useful from a biological perspective because it promotes the localization of objects, and object parts relative to each other. The proposed medial-point representation is similar to medial-axis type representations, but it is more compact. The medial points are those points along the medial axis that are equidistant from the longest segments of the boundary, therefore they represent the largest amount of edge information. The main advantage is that the original image can be reduced to a small number of points. We also provide psychophysical correlates of the representation for shapes with increasing complexity. Using a reverse mapping technique, we find that variations of contrast sensitivity within figures are defined by the shape of the bounding contour, and the peaks in the sensitivity maps correspond to the medial points of the proposed representation. PMID:9798002

Kovács, I; Fehér, A; Julesz, B

1998-08-01

274

Does Pointing Comprehension Disturb Controlling Action? :Evidence from 2-year-old children  

Microsoft Academic Search

This study investigated whether 2-year-old children failed to control actions when they were given wrong social cues by another person in a searching task. In a control session, children observed an experimenter hid a toy in one of three cups. Then they were allowed to search a toy. In a test session, children observed a toy was hidden in one

Yusuke Moriguchi; Shoji Itakura

2005-01-01

275

Non-equilibrium Charge Fluctuations as a Source of Inelastic Back-action in Quantum Point Contact Qubit Detectors  

NASA Astrophysics Data System (ADS)

Many recent experiments make use of a quantum point contact (QPC) as a qubit readout (e.g., of a double quantum dot (DQD) qubit). It has long been realized that QPC current fluctuations can give rise to inelastic back-action effects on the DQD [1] [2]. In contrast, the role of QPC charge fluctuations in generating inelastic back-action has not been fully studied, despite the fact that this is a more fundamental mechanism. We provide a full theoretical study of charge-noise induced inelastic back-action effects in a QPC plus DQD system, showing that these effects should be appreciable in typical experimental setups. We also discuss a novel contribution to the charge noise associated with the physics of Friedel oscillations. Finally, we discuss how the effects of charge noise back-action can be distinguished from current noise back-action in experiment. [1] S. Gustavsson et al., Phys. Rev. Lett., 99, 206804 (2007).[2] R. Aguado and L.P. Kouwenhoven, Phys. Rev. Lett., 84, 091987 (2000).

Young, Carolyn; Clerk, Aashish

2009-03-01

276

Nonperturbative Saddle Point for the Effective Action of Disordered and Interacting Electrons in 2D  

NASA Astrophysics Data System (ADS)

We find a nonperturbative saddle-point solution for the nonlinear sigma model proposed by Finkelstein for interacting and disordered electronic systems. Spin rotation symmetry, present in the original saddle-point solution, is spontaneously broken at one loop, as in the Coleman-Weinberg mechanism. The new solution is singular in both the disorder and triplet interaction strengths, and it also explicitly demonstrates that a nontrivial ferromagnetic state appears in a theory where the disorder average is carried out from the outset.

Chamon, Claudio; Mucciolo, Eduardo R.

2000-12-01

277

Application of Fixed Scale Approach to Static Quark Free Energies in Quenched and 2+1 Flavor Lattice QCD with Improved Wilson Quark Action  

NASA Astrophysics Data System (ADS)

The free energies of static quarks and the Debye screening masses in the quark gluon plasma are studied using Polyakov-line correlation functions in lattice QCD adopting the fixed-scale approach in which temperature is varied without changing the spatial volume and the renormalization factors. We calculate static-quark free energies in various color channels in the high temperature phase up to about 3.5 times the (pseudo-)critical temperature, performing lattice simulations both in quenched and 2 + 1 flavor QCD. For the quenched simulations, we adopt the plaquette gauge action on anisotropic 20^3 × N_t lattices with N_t = 8-26 at the renormalized anisotropy a_s / a_t ? 4. For 2 + 1 flavor QCD, we adopt the renormalization-group improved Iwasaki gluon action and the non-perturbatively O(a)-improved Wilson quark action on isotropic 32^3 × N_t lattices with N_t = 4-12 at m_{PS}/m_{V} = 0.63 (0.74) for the light (strange) flavors. We find that the color-singlet free energies at high temperatures converge to the zero-temperature static-quark potential evaluated from the Wilson-loop at short distances. This is in accordance with the theoretical expectation that the short distance physics is insensitive to the temperature. At long distances, the free energies approach twice the single-quark free energies, implying that the interaction between static quarks is fully screened. We find that the static-quark free energies for various color channels turn out to be well described by the screened Coulomb form, and the color-channel dependence of the inter-quark interaction can be described by the kinetic Casimir factor inspired from the lowest order perturbation theory. We also discuss comparison with a prediction of the thermal perturbation theory and flavor dependence of the screening masses.

Maezawa, Y.; Umeda, T.; Aoki, S.; Ejiri, S.; Hatsuda, T.; Kanaya, K.; Ohno, H.; WHOT-QCD Collaboration

2012-11-01

278

How does action resist visual illusion? Uncorrected oculomotor information does not account for accurate pointing in peripersonal space.  

PubMed

Using spatially identical displays (variants of the Müller-Lyer illusion), we compared the accuracy of spatial verbal judgments with that of saccadic (eye) and pointing (hand) movements. Verbal judgments showed a clear effect of the illusion. The amplitude of the primary saccade from one endpoint of the pattern (at fixation) to the other also showed an effect of the illusion. Conversely, movement amplitudes when pointing from one endpoint (initial finger position) to the other were significantly more accurate than both saccades and verbal responses. In a control experiment in which the viewing conditions between the saccade and pointing experiments were equalized, saccade amplitude was again affected by the illusion. In several studies, systematic biases in conscious spatial judgments have been contrasted with accurate open-loop pointing in peripersonal space. It has been proposed that such seeming dissociations between vision-for-action and vision-for-consciousness might in fact be because of a simple oculomotor strategy: saccade to the target before it disappears, then use the efference copy of the (accurate) saccadic movement to drive pointing. The present data do not support the hypothesis in this simple form. PMID:15791463

Bernardis, Paolo; Knox, Paul; Bruno, Nicola

2004-12-10

279

Closure Report for Corrective Action Unit 262: Area 25 Septic Systems and Underground Discharge Point, Nevada Test Site, Nevada  

SciTech Connect

This Closure Report (CR) documents the activities undertaken to close Corrective Action Unit (CAU) 262: Area 25 Septic Systems and Underground Discharge Point, in accordance with the Federal Facility Agreement and Consent Order (FFACO) of 1996. Site closure was performed in accordance with the Nevada Division of Environmental Protection (NDEP)-approved Corrective Action Plan (CAP) for CAU 262 (U.S. Department of Energy, National Nuclear Security Administration Nevada Operations Office [NNSA/NV, 2002a]). CAU 262 is located at the Nevada Test Site (NTS) approximately 105 kilometers (65 miles) northwest of Las Vegas, Nevada. CAU 262 consists of the following nine Corrective Action Sites (CASs) located in Area 25 of the NTS: CAS 25-02-06, Underground Storage tank CAS 25-04-06, Septic Systems A and B CAS 25-04-07, Septic System CAS 25-05-03, Leachfield CAS 25-05-05, Leachfield CAS 25-05-06, Leachfield CAS 25-05-08, Radioactive Leachfield CAS 25-05-12, Leachfield CAS 25-51-01, Dry Well.

D. S. Tobiason

2003-07-01

280

Dissemination of developed in VNIIOFI high temperature Fix-points based on Metal-Carbon Eutectics for Space Applications of ultra-precise Radiometry and Spectral Radiation Thermometry Measurements  

NASA Astrophysics Data System (ADS)

Several fixed-point cells (with 2 and 4 mm apertures for spectral-radiance application, and with 8 and 10 mm apertures (for the spectral irradiance measurements) have been designed and investigated at VNIIOFI consisted of a high- purity graphite crucibles containing Re-C ingots with nominal total impurity levels of 5,5N at the eutectic composition(s). It was investigated that fix-point reproducibility (freezing plateau level for all measured cells) was up to 0.01...0.02% between series of measurements / crucibles, and 0.002...0.004% within a sample measurement session, i.e. better than 100 mK. Measurements of high-temperature fixed points blackbodies based on Ir-C and Re-C eutectics were carried out to investigate their applicability as radiation sources for precision photometry and radiometry, in particular for astronomy and space applications, like long-term measurements of solar variability, etc. The measurement results encourage that the utilization of a new series of a high-temperature fix-point sources hand in hand with cryo-radiometer detector could cardinally change the situation in reproduction of spectral radiance, irradiance and temperature international scales. Several more high-temperature eutectics (e.g. TiC-C metal- carbon eutectics with T = 3057 C) are being investigated further for use as high- temperature fixed-point radiance and irradiance sources in o der to increase ther accuracy of radiometric and radiance-temperature scales above the conventionally assigned values of temperatures of ITS-90.

Sapritsky, V.; Ogarev, S.; Khlevnoy, B.

281

Determination of growth inhibitory action point of interferon ? on WISH cells in cell cycle progression and the window of responsiveness of the cells to the interferon  

Microsoft Academic Search

We had earlier shown that human foetal epithelial cells (WISH), growth-inhibited by interferon ? (IFN?), were reversibly detained at a point prior to DNA synthesis. In the present study, we determined the window of action of IFN? in the G1 phase duration and the exact point of detention of WISH cells in cell cycle progression with respect to the known

Surabhi Vashistha; Supriya Patil; Chirag Joshi; Parthasarathi Ajitkumar

2007-01-01

282

Computational fluid dynamics simulations of fluid flow and heat transfer at the wall–particle contact points in a fixed-bed reactor  

Microsoft Academic Search

An accurate description of the fluid flow and heat transfer within a fixed-bed reactor is desirable. The prevailing models of fluid flow invoke either a constant velocity (plug-flow) profile, or make use of a single axial velocity component with radial variation across the tube diameter. However, difficulties in predicting reactor performance and the wide disagreement between effective heat transfer coefficients

S. A. Logtenberg; M. Nijemeisland; A. G. Dixon

1999-01-01

283

D2AM, a beamline with a high-intensity point-focusing fixed-exit monochromator for multiwavelength anomalous diffraction experiments.  

PubMed

D2AM is a french CRG beamline installed at the ESRF (European Synchrotron Radiation Facility) in Grenoble, with half of the time dedicated to biological macromolecule crystallography and half to materials science studies (diffraction, wide-angle and small-angle scattering). It is constructed at the front-end BM02 of the ESRF storage ring, using the X-ray beam from a 0.8 T bending magnet. D2AM entered into routine operation at the end of 1994, and is used either for single-wavelength or for multiwavelength anomalous diffraction studies. The beam is monochromated by an Si[111] two-crystal monochromator with a resolution of about 2 x 10(-4). The first crystal is water cooled. The X-ray photon energy covers the range between 6.5 keV (lambda approximately 1.9 A) and 17 keV (lambda approximately 0.7 A), a domain of energy with many K or L absorption edges of heavy atoms of interest for biological macromolecules studies and in materials science. The X-ray beam is focused in the vertical plane by two long curved mirrors and in the horizontal plane by the second crystal of the monochromator which is given an adjustable sagittal curvature. A spot size of 0.3 x 0.1 mm (FWHM) is measured at the sample position. Both mirrors are cut out of a 6"-diameter 1.1 m-long Si single crystal, polished and coated with a 400 A Pt thin film. The rugosity is better than 4 A r.m.s. and the longitudinal slope error is better than 5 x 10(-6) rad r.m.s. The first mirror is water cooled, the second is not. The beam intensity on the sample is about 10(11) photon s(-1) on a 0.3 x 0.3 mm focus area at 100 mA in the storage ring of the ESRF. The harmonic rejection ratio obtained with the two mirrors is better than 10(-5) for lambda/3. The combined optical system, mirror/monochromating-crystals/mirror, used on D2AM constitutes altogether a high-intensity point-focusing fixed-exit monochromator, which has the additional property that the energy resolution is not dependent on the beam divergence in use. Its stability and resolution are perfectly adapted to multiwavelength anomalous diffraction studies. The alignment of the mirrors and the monochromator is fully automated, taking 5 min, with the exception of the adjustment of the sagittal focusing. During multiwavelength diffraction experiments the wavelength is changed by a fast single monochromator rotation. Neither realignment of the mirrors nor readjustment of the beam focusing are necessary. The stability and reproducibility of the selected X-ray photon energy is better than 0.5 eV. PMID:16687847

Ferrer, J L; Simon, J P; Bérar, J F; Caillot, B; Fanchon, E; Kaïkati, O; Arnaud, S; Guidotti, M; Pirocchi, M; Roth, M

1998-11-01

284

Corrective Action Investigation Plan for Corrective Action Unit 406: Area 3 Building 03-74 and Building 03-58 Under ground Discharge Points and Corrective Action Unit 429: Area 3 Building 03-55 and Area 9 Building 09-52 Underground Discharge Points, Tonopah Test Range, Nevada  

SciTech Connect

This Corrective Action Investigation Plan (CAIP) has been developed in accordance with the Federal Facility Agreement and Consent Order (FFACO) that was agreed to by the US Department of Energy, Nevada Operations Office (DOE/NV); the State of Nevada Division of Environmental Protection (NDEP); and the US Department of Defense (FFACO, 1996). The CAIP is a document that provides or references all of the specific information for investigation activities associated with Corrective Action Units (CAUs) or Corrective Action Sites (CASs). According to the FFACO (1996), CASs are sites potentially requiring corrective action(s) and may include solid waste management units or individual disposal or release sites. Corrective Action Units consist of one or more CASs grouped together based on geography, technical similarity, or agency responsibility for the purpose of determining corrective actions. This CAIP contains the environmental sample collection objectives and the criteria for conducting site investigation activities at the Underground Discharge Points (UDPs) included in both CAU 406 and CAU 429. The CAUs are located in Area 3 and Area 9 of the Tonopah Test Range (TTR). The TTR, included in the Nellis Air Force Range, is approximately 255 kilometers (km) (140 miles [mi]) northwest of Las Vegas, Nevada.

DOE /NV

1999-05-20

285

Addendum to the Corrective Action Decision Document/Closure Report for Corrective Action Unit 406: Area 3 Building 03-74 & Building 03-58 Underground Discharge Points and Corrective Action Unit 429: Area 3 Building 03-55 & Area 9 Building 09-52 Underground Discharge Points, Tonopah Test Range, Nevada, Revision 0  

SciTech Connect

This document constitutes an addendum to the March 2000, Corrective Action Decision Document / Closure Report for Corrective Action Unit 406: Area 3 Building 03-74 & 03-58 Underground Discharge Points and Corrective Action Unit 429: Area 3 Building 03-55 & Area 9 Building 09-52 Underground Discharge Points (TTR) as described in the document Recommendations and Justifications for Modifications for Use Restrictions Established under the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office Federal Facility Agreement and Consent Order (UR Modification document) dated February 2008. The UR Modification document was approved by NDEP on February 26, 2008. The approval of the UR Modification document constituted approval of each of the recommended UR modifications. In conformance with the UR Modification document, this addendum consists of: • This cover page that refers the reader to the UR Modification document for additional information • The cover and signature pages of the UR Modification document • The NDEP approval letter • The corresponding section of the UR Modification document This addendum provides the documentation justifying the cancellation of the UR for CAS 03-51-001-0355 – Photo Shop UDP, Drains in CAU 429. It should be noted that there are no changes to CAU 406. This UR was established as part of a Federal Facility Agreement and Consent Order (FFACO) corrective action and is based on the presence of contaminants at concentrations greater than the action levels established at the time of the initial investigation (FFACO, 1996; as amended August 2006). Since this UR was established, practices and procedures relating to the implementation of risk-based corrective actions (RBCA) have changed. Therefore, this UR was re-evaluated against the current RBCA criteria as defined in the Industrial Sites Project Establishment of Final Action Levels (NNSA/NSO, 2006c). This re-evaluation consisted of comparing the original data (used to define the need for the UR) to risk-based final action levels (FALs) developed using the current Industrial Sites RBCA process. The re-evaluation resulted in a recommendation to remove the UR because contamination is not present at the site above the risk-based FALs. Requirements for inspecting and maintaining this UR will be canceled, and the postings and signage at this site will be removed. Fencing and posting may be present at this site that are unrelated to the FFACO UR such as for radiological control purposes as required by the NV/YMP Radiological Control Manual (NNSA/NSO, 2004f). This modification will not affect or modify any non-FFACO requirements for fencing, posting, or monitoring at this site.

Lynn Kidman

2008-10-01

286

Spike-Timing-Dependent Plasticity: The Relationship to Rate-Based Learning for Models with Weight Dynamics Determined by a Stable Fixed Point  

Microsoft Academic Search

Experimental evidence indicates that synaptic modiflcation depends upon the timing relationship between the presynaptic inputs and the output spikes that they generate. In this paper results are presented for models of spike timing- dependent plasticity (STDP) whose weight dynamics is determined by a stable flxed-point. Four classes of STDP are identifled on the basis of the time-extent of their input-output

Anthony N. Burkitt; Hamish Meffin; David. B. Grayden

2004-01-01

287

Corrective Action Investigation Plan for Corrective Action Unit 262: Area 25 Septic Systems and Underground Discharge Point, Nevada Test Site, Nevada, Revision No. 1 (9/2001)  

SciTech Connect

This corrective action investigation plan contains the U.S. Department of Energy, Nevada Operations Office's approach to collect data necessary to evaluate corrective action alternatives appropriate for the closure of Corrective Action Unit (CAU) 262 under the Federal Facility Agreement and Consent Order. Corrective Action Unit 262 consists of nine Corrective Action Sites (CASs): Underground Storage Tank (25-02-06), Septic Systems A and B (25-04-06), Septic System (25-04-07), Leachfield (25-05-03), Leachfield (25-05-05), Leachfield (25-05-06), Radioactive Leachfield (25-05-08), Leachfield (25-05-12), and Dry Well (25-51-01). Situated in Area 25 at the Nevada Test Site (NTS), sites addressed by CAU 262 are located at the Reactor-Maintenance, Assembly, and Disassembly (R-MAD); Test Cell C; and Engine-Maintenance, Assembly, and Disassembly (E-MAD) facilities. The R-MAD, Test Cell C, and E-MAD facilities supported nuclear rocket reactor and engine testing as part of the Nuclear Rocket Development Station. The activities associated with the testing program were conducted between 1958 and 1973. Based on site history collected to support the Data Quality Objectives process, contaminants of potential concern (COPCs) for the site include oil/diesel-range total petroleum hydrocarbons, volatile organic compounds, semivolatile organic compounds, polychlorinated biphenyls, Resource Conservation and Recovery Act metals, and gamma-emitting radionuclides, isotopic uranium, isotopic plutonium, strontium-90, and tritium. The scope of the corrective action field investigation at the CAU will include the inspection of portions of the collection systems, sampling the contents of collection system features in situ of leachfield logging materials, surface soil sampling, collection of samples of soil underlying the base of inlet and outfall ends of septic tanks and outfall ends of diversion structures and distribution boxes, collection of soil samples from biased or a combination of biased and random locations within the boundaries of the leachfields, collection of soil samples at stepout locations (where needed) to further define lateral and vertical extent of contamination, conduction of discrete field screening, and logging of soil borings and collection of geotechnical samples to assess soil characteristics. Historical information indicates that significant quantities of radioactive material were produced during the rocket engine testing program, some of which was disposed of in radioactive waste disposal systems (posted leachfields) at each of these locations. Process and sanitary effluents were generated and disposed of in other leachfields. The results of this field investigation will be used to develop and evaluate corrective action alternatives for these CASs.

NNSA /NV

2000-07-20

288

Sequential super-stereotypy of an instinctive fixed action pattern in hyper-dopaminergic mutant mice: a model of obsessive compulsive disorder and Tourette's  

Microsoft Academic Search

BACKGROUND: Excessive sequential stereotypy of behavioral patterns (sequential super-stereotypy) in Tourette's syndrome and obsessive compulsive disorder (OCD) is thought to involve dysfunction in nigrostriatal dopamine systems. In sequential super-stereotypy, patients become trapped in overly rigid sequential patterns of action, language, or thought. Some instinctive behavioral patterns of animals, such as the syntactic grooming chain pattern of rodents, have sufficiently complex

Kent C Berridge; J Wayne Aldridge; Kimberly R Houchard; Xiaoxi Zhuang

2005-01-01

289

To fix or not to fix? How corruptors decide to fix football matches  

Microsoft Academic Search

This paper examines the decisions of the internal corruptors in fixing football games. The methodology is a mixture of interviews, database analysis and examination of a specific series of taped phone calls of a corrupt Russian football official. It finds that generally, this type of match-fixing occurs only after a specific point in the season. There are five implicit questions

Declan Hill

2009-01-01

290

Determination of growth inhibitory action point of interferon gamma on WISH cells in cell cycle progression and the window of responsiveness of the cells to the interferon.  

PubMed

We had earlier shown that human foetal epithelial cells (WISH), growth-inhibited by interferon gamma (IFNgamma), were reversibly detained at a point prior to DNA synthesis. In the present study, we determined the window of action of IFNgamma in the G1 phase duration and the exact point of detention of WISH cells in cell cycle progression with respect to the known points of detention by the inhibitors of DNA replication initiation (aphidicolin and carbonyl diphosphonate) and of activation of replication protein A (6-dimethylaminopurine), of which RPA activation being the earlier event compared to DNA replication initiation in cell cycle progression. WISH cells, which were released from IFNgamma-induced arrest, permeabilised and exposed independently to these inhibitors show that IFNgamma detains WISH cells prior to initiation of DNA synthesis. Further, exposure of IFNalpha-synchronized (at G0/G1) or mimosine-synchronized (at G1/S) WISH cells to IFNgamma, which was added at different time points post-release from the synchronizing agent, showed that the cells were promptly responsive to the growth inhibitory action of IFNgamma only during the first 11h in G1 phase. Taken together, these results suggest that IFNgamma inhibits growth of WISH cells by detaining them at a point prior to initiation of DNA synthesis and that the IFN acts within the first 11h in G1 phase of the cell cycle. PMID:17449270

Vashistha, Surabhi; Patil, Supriya; Joshi, Chirag; Ajitkumar, Parthasarathi

2007-04-20

291

Methods for the assessment of correction for chemical-impurity effects and related uncertainty in ITS-90 fixed points, namely of e-H2, Ne, O2 and Ar  

NASA Astrophysics Data System (ADS)

The expression of uncertainty in the field of metrology is based, since 1993, on the Guide to the Expression of Uncertainty in Measurement. According to this, 'it is assumed that the results of a measurement have been corrected for all recognized significant systematic effects'. Since the International Temperature Scale of 1990 considers the substances used for the realization of the 'fixed points' to be ideally pure, to fully implement the intent of the GUM corrections should be applied for any chemical impurities that affect the value of the measurand. The present paper aims at reviewing an aspect that must be tackled to arrive to reliable and scientifically sound corrections: the use of an appropriate statistical method. In addition to the SIE, OME and hybrid methods recommended by the CCT, two new approaches are proposed in this paper, called one-sided OME and Average Overall Estimate (AOE). They are illustrated and their merits compared with the previous one, by applying them for the correction of the measured values of the triple-point temperature of the four gaseous substances (hydrogen, neon, oxygen and argon) used for the realization of the ITS-90 reference points in the range 13.8 K to 273.16 K. Some suggestions are drawn from the resulting evidence.

Pavese, Franco

2011-10-01

292

United States Air Force 611th Air Support Group/Civil Engineering Squadron Elmendorf AFB, Alaska. Decision document for no further response action planned: Bullen Point Radar Installation, Alaska. Final report  

SciTech Connect

This Decision Document discusses the selection of no further action as the recommended action for two sites located at the Bullen Point radar installation. The United States Air Force (Air Force) completed a Remedial Investigation/Feasibility Study and a Risk Assessment for the five sites located at the Bullen Point installation (U.S. Air Force 1996a,b). Based on the findings of these activities, two sites are recommended for no further action. Sites at the Bullen Point radar installation recommended for no further action are: Old Landfill/Dump Site East (LF06) and Drum Storage Area (SS10).

Karmi, S.

1996-05-24

293

Calculation of Hirzebruch genera for manifolds acted on by the group Z/p via invariants of the action  

NASA Astrophysics Data System (ADS)

We obtain general formulae expressing Hirzebruch genera of a manifold with Z/p-action in terms of invariants of this action (the sets of weights of fixed points). As an illustration, we consider numerous particular cases of well-known genera, in particular, the elliptic genus. We also describe the connection with the so-called Conner-Floyd equations for the weights of fixed points.

Panov, T. E.

1998-06-01

294

United States Air Force 611th Air Support Group/Civil Engineering Squadron, Elmendorf AFB, Alaska. Decision document for no further response action planned Oliktok Point Radar Installation, Alaska. Final report  

SciTech Connect

This Decision Document discusses the selection of no further action as the recommended action for four sites located at the Oliktok Point radar installation. The United States Air Force (Air Force) completed a Remedial Investigation/Feasibility Study and a Risk Assessment for the eight sites located at the Oliktok Point installation (U.S. Air Force 1996a,b). Based on the findings of these activities, four sites are recommended for no further action.

Karmi, S.

1996-06-03

295

Alarm points for fixed oxygen monitors  

SciTech Connect

Oxygen concentration monitors were installed in a vault where numerous pipes carried inert cryogens and gases to the Mirror Fusion Test Facility (MFTF-B) experimental vessel at Lawrence Livermore National Laboratory (LLNL). The problems associated with oxygen-monitoring systems and the reasons why such monitors were installed were reviewed. As a result of this review, the MFTF-B monitors were set to sound an evacuation alarm when the oxygen concentration fell below 18%. We chose the 18% alarm criterion to minimize false alarms and to allow time for personnel to escape in an oxygen-deficient environment.

Miller, G.C.

1987-05-01

296

Fix point theorems in metric spaces  

Microsoft Academic Search

In this paper results similar to the well-known contraction theorems of BA~ACH are obtained*). These classical theorems, our mentioned similar results and theorems of K~N.~, EDELSTE~ and Sr~GH are all, in fact, corollaries of a few more general theorems, as we shall see. Theorem 1. Let M be a co~plete metric space, ~., 8, 7 real numbers with ~. <

Tudor Zamfirescu

1972-01-01

297

Addendum to the Closure Report for Corrective Action Unit 262: Area 25 Septic Systems and Underground Discharge Point, Nevada Test Site, Nevada  

SciTech Connect

This document constitutes an addendum to the July 2003, Closure Report for Corrective Action Unit 262: Area 25 Septic Systems and Underground Discharge Point as described in the document Recommendations and Justifications for Modifications for Use Restrictions Established under the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office Federal Facility Agreement and Consent Order (UR Modification document) dated February 2008. The UR Modification document was approved by NDEP on February 26, 2008. The approval of the UR Modification document constituted approval of each of the recommended UR modifications.

Lynn Kidman

2008-10-01

298

Addendum to the Closure Report for Corrective Action Unit 423: Area 3 Building 03-60 Underground Discharge Point, Tonopah Test Range, Nevada, Revision 0  

SciTech Connect

This document constitutes an addendum to the July 1999, Closure Report for Corrective Action Unit 423: Area 3 Building 0360 Underground Discharge Point, Tonopah Test Range, Nevada as described in the document Recommendations and Justifications for Modifications for Use Restrictions Established under the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office Federal Facility Agreement and Consent Order (UR Modification document) dated February 2008. The UR Modification document was approved by NDEP on February 26, 2008. The approval of the UR Modification document constituted approval of each of the recommended UR modifications. In conformance with the UR Modification document, this addendum consists of: • This cover page that refers the reader to the UR Modification document for additional information • The cover and signature pages of the UR Modification document • The NDEP approval letter • The corresponding section of the UR Modification document This addendum provides the documentation justifying the cancellation of the UR for CAS 03-02-002-0308, Underground Discharge Point. This UR was established as part of a Federal Facility Agreement and Consent Order (FFACO) corrective action and is based on the presence of contaminants at concentrations greater than the action levels established at the time of the initial investigation (FFACO, 1996; as amended August 2006). Since this UR was established, practices and procedures relating to the implementation of risk-based corrective actions (RBCA) have changed. Therefore, this UR was re-evaluated against the current RBCA criteria as defined in the Industrial Sites Project Establishment of Final Action Levels (NNSA/NSO, 2006c). This re-evaluation consisted of comparing the original data (used to define the need for the UR) to risk-based final action levels (FALs) developed using the current Industrial Sites RBCA process. The re-evaluation resulted in a recommendation to remove the UR because contamination is not present at the site above the risk-based FALs. Requirements for inspecting and maintaining this UR will be canceled, and the postings and signage at this site will be removed. Fencing and posting may be present at this site that are unrelated to the FFACO UR such as for radiological control purposes as required by the NV/YMP Radiological Control Manual (NNSA/NSO, 2004f). This modification will not affect or modify any non-FFACO requirements for fencing, posting, or monitoring at this site.

Lynn Kidman

2008-10-01

299

Algorithmic-Reducibility = Renormalization-Group Fixed-Points; "Noise"-Induced Phase-Transitions (NITs) to Accelerate Algorithmics ("NIT-Picking") Replacing CRUTCHES!!!: Gauss Modular/Clock-Arithmetic Congruences = Signal X Noise PRODUCTS. .  

NASA Astrophysics Data System (ADS)

Cook-Levin computational-"complexity"(C-C) algorithmic-equivalence reduction-theorem reducibility equivalence to renormalization-(semi)-group phase-transitions critical-phenomena statistical-physics universality-classes fixed-points, is exploited with Gauss modular/clock-arithmetic/model congruences = signal X noise PRODUCT reinterpretation. Siegel-Baez FUZZYICS=CATEGORYICS(SON of "TRIZ"): Category-Semantics(C-S) tabular list-format truth-table matrix analytics predicts and implements "noise"-induced phase-transitions (NITs) to accelerate versus to decelerate Harel [Algorithmics(1987)]-Sipser[Intro. Theory Computation(1997) algorithmic C-C: "NIT-picking" to optimize optimization-problems optimally(OOPO). Versus iso-"noise" power-spectrum quantitative-only amplitude/magnitude-only variation stochastic-resonance, this "NIT-picking" is "noise" power-spectrum QUALitative-type variation via quantitative critical-exponents variation. Computer-"science" algorithmic C-C models: Turing-machine, finite-state-models/automata, are identified as early-days once-workable but NOW ONLY LIMITING CRUTCHES IMPEDING latter-days new-insights!!!

Siegel, J.; Carl-Ludwig Siegel, Edward

2011-03-01

300

Opposing Action of Nuclear Factor ?B and Polo-like Kinases Determines a Homeostatic End Point for Excitatory Synaptic Adaptation.  

PubMed

Homeostatic responses critically adjust synaptic strengths to maintain stability in neuronal networks. Compensatory adaptations to prolonged excitation include induction of Polo-like kinases (Plks) and degradation of spine-associated Rap GTPase-activating protein (SPAR) to reduce synaptic excitation, but mechanisms that limit overshooting and allow refinement of homeostatic adjustments remain poorly understood. We report that Plks produce canonical pathway-mediated activation of the nuclear factor ?B (NF-?B) transcription factor in a process that requires the kinase activity of Plks. Chronic elevated activity, which induces Plk expression, also produces Plk-dependent activation of NF-?B. Deficiency of NF-?B, in the context of exogenous Plk2 expression or chronic elevated neuronal excitation, produces exaggerated homeostatic reductions in the size and density of dendritic spines, synaptic AMPA glutamate receptor levels, and excitatory synaptic currents. During the homeostatic response to chronic elevated activity, NF-?B activation by Plks subsequently opposes Plk-mediated SPAR degradation by transcriptionally upregulating SPAR in mouse hippocampal neurons in vitro and in vivo. Exogenous SPAR expression can rescue the overshooting of homeostatic reductions at excitatory synapses in NF-?B-deficient neurons responding to elevated activity. Our data establish an integral feedback loop involving NF-?B, Plks, and SPAR that regulates the end point of homeostatic synaptic adaptation to elevated activity and are the first to implicate a transcription factor in the regulation of homeostatic synaptic responses. PMID:24133254

Mihalas, Anca B; Araki, Yoichi; Huganir, Richard L; Meffert, Mollie K

2013-10-16

301

Wide-range visualization of compound nerve action magnetic fields in the human median and ulnar nerves from the forearm to Erb's point.  

PubMed

We successfully visualized the compound nerve action magnetic fields (CAFs) in the human median and ulnar nerves from the forearm to Erb's point. To observe the CAFs, we used a superconducting quantum interference device gradiometer system that was developed for human peripheral nerves. The CAFs were visualized as a quadrupole pattern consisting of leading and trailing dipoles. The CAFs propagated along the anatomical pathway and extended longitudinally in the proximal segment. The most reasonable explanation is that the peak separation in the trailing dipole appeared when the leading dipole reached the proximal segment after stimulation of the median nerve at the wrist. A temporal dispersion of the CAFs was suggested to be visualized. PMID:14746886

Nakanishi, Kazuyoshi; Mashiko, Takunori; Fujimoto, Yoshinori; Tanaka, Nobuhiro; Iwase, Yoshiyuki; Ishida, Osamu; Ochi, Mitsuo

2004-02-12

302

Potentiation of E-4031-induced torsade de pointes by HMR1556 or ATX-II is not predicted by action potential short-term variability or triangulation  

PubMed Central

Background and purpose: Torsade de pointes (TdP) can be induced by a reduction in cardiac repolarizing capacity. The aim of this study was to assess whether I Ks blockade or enhancement of I Na could potentiate TdP induced by I Kr blockade and to investigate whether short-term variability (STV) or triangulation of action potentials preceded TdP. Experimental approach: Experiments were performed in open-chest, pentobarbital-anaesthetized, ?1-adrenoceptor-stimulated, male New Zealand White rabbits, which received three consecutive i.v. infusions of either the I Kr blocker E-4031 (1, 3 and 10?nmol kg?1 min?1), the I Ks blocker HMR1556 (25, 75 and 250 nmol kg?1 min?1) or E-4031 and HMR1556 combined. In a second study rabbits received either the same doses of E-4031, the I Na enhancer, ATX-II (0.4, 1.2 and 4.0 nmol kg?1) or both of these drugs. ECGs and epicardial monophasic action potentials were recorded. Key results: HMR1556 alone did not cause TdP but increased E-4031-induced TdP from 25 to 80%. ATX-II alone caused TdP in 38% of rabbits, as did E-4031; 75% of rabbits receiving both drugs had TdP. QT intervals were prolonged by all drugs but the extent of QT prolongation was not related to the occurrence of TdP. No changes in STV were detected and triangulation was only increased after TdP occurred. Conclusions and implications: Giving modulators of ion channels in combination substantially increased TdP but, in this model, neither STV nor triangulation of action potentials could predict TdP.

Michael, G; Dempster, J; Kane, K A; Coker, S J

2007-01-01

303

Sphingosine-1-phosphate-mediated osteoclast precursor monocyte migration is a critical point of control in antibone-resorptive action of active vitamin D.  

PubMed

The migration and positioning of osteoclast precursor monocytes are controlled by the blood-enriched lipid mediator sphingosine-1-phosphate (S1P) and have recently been shown to be critical points of control in osteoclastogenesis and bone homeostasis. Here, we show that calcitriol, which is the hormonally active form of vitamin D, and its therapeutically used analog, eldecalcitol, inhibit bone resorption by modulating this mechanism. Vitamin D analogs have been used clinically for treating osteoporosis, although the mode of its pharmacologic action remains to be fully elucidated. In this study, we found that active vitamin D reduced the expression of S1PR2, a chemorepulsive receptor for blood S1P, on circulating osteoclast precursor monocytes both in vitro and in vivo. Calcitriol- or eldecalcitol-treated monocytoid RAW264.7 cells, which display osteoclast precursor-like properties, migrated readily to S1P. Concordantly, the mobility of circulating CX3CR1(+) osteoclast precursor monocytes was significantly increased on systemic administration of active vitamin D. These results show a mechanism for active vitamin D in controlling the migratory behavior of circulating osteoclast precursors, and this action should be conducive to limiting osteoclastic bone resorption in vivo. PMID:23569273

Kikuta, Junichi; Kawamura, Shunsuke; Okiji, Fumie; Shirazaki, Mai; Sakai, Sadaoki; Saito, Hitoshi; Ishii, Masaru

2013-04-08

304

Sphingosine-1-phosphate-mediated osteoclast precursor monocyte migration is a critical point of control in antibone-resorptive action of active vitamin D  

PubMed Central

The migration and positioning of osteoclast precursor monocytes are controlled by the blood-enriched lipid mediator sphingosine-1-phosphate (S1P) and have recently been shown to be critical points of control in osteoclastogenesis and bone homeostasis. Here, we show that calcitriol, which is the hormonally active form of vitamin D, and its therapeutically used analog, eldecalcitol, inhibit bone resorption by modulating this mechanism. Vitamin D analogs have been used clinically for treating osteoporosis, although the mode of its pharmacologic action remains to be fully elucidated. In this study, we found that active vitamin D reduced the expression of S1PR2, a chemorepulsive receptor for blood S1P, on circulating osteoclast precursor monocytes both in vitro and in vivo. Calcitriol- or eldecalcitol-treated monocytoid RAW264.7 cells, which display osteoclast precursor-like properties, migrated readily to S1P. Concordantly, the mobility of circulating CX3CR1+ osteoclast precursor monocytes was significantly increased on systemic administration of active vitamin D. These results show a mechanism for active vitamin D in controlling the migratory behavior of circulating osteoclast precursors, and this action should be conducive to limiting osteoclastic bone resorption in vivo.

Kikuta, Junichi; Kawamura, Shunsuke; Okiji, Fumie; Shirazaki, Mai; Sakai, Sadaoki; Saito, Hitoshi; Ishii, Masaru

2013-01-01

305

Serial floating point formatter  

SciTech Connect

A floating point formatter for changing fixed point serial digital data, such as that received by a seismic data acquisition system, is disclosed wherein fixed point serial digital data is received and scaled to remove any bias added by preamplification. The scaled data is shifted a predetermined number of bits and a resulting exponent is calculated. The shifted data signal and corresponding exponent are combined and further scaled to permit stacking the data without exceeding the system capacity.

Peterson, R. D.; Penner, W. A.

1985-11-12

306

An effective action for asymptotically safe gravity  

NASA Astrophysics Data System (ADS)

Asymptotically safe theories of gravitation have received great attention in recent times. In this framework an effective action embodying the basic features of the renormalized flow around the non-Gaussian fixed-point is derived and its implications for the early universe are discussed. In particular, a landscape of a countably infinite number of cosmological inflationary solutions characterized by an unstable de Sitter phase lasting for a large enough number of e-folds is found.

Bonanno, Alfio

2012-04-01

307

STAR as a fixed target experiment?  

NASA Astrophysics Data System (ADS)

Collisions between gold or copper ions in the RHIC beam with aluminum nuclei in the beam pipe allow us to analyze fixed target interactions with the STAR detector at RHIC. These lower energy fixed target collisions may allow us to extend the low energy reach of the RHIC beam energy scan and possibly improve the chance of finding the critical point of the hadronic to quark matter phase boundary. In this talk, we will present preliminary results of spectra analysis for the fixed target collisions from various low energy test runs. Moreover, the viability of doing fixed target experiments with a collider detector will be discussed.

Haag, Brooke; Cebra, Daniel; Reed, Rosi

2009-11-01

308

Corrective Action Investigation Plan for Corrective Action Unit 406: Area 3 Building 03-74 and Building 03-58 Under ground Discharge Points and Corrective Action Unit 429: Area 3 Building 03-55 and Area 9 Building 09-52 Underground Discharge Points, Tonopah Test Range, Nevada  

Microsoft Academic Search

This Corrective Action Investigation Plan (CAIP) has been developed in accordance with the Federal Facility Agreement and Consent Order (FFACO) that was agreed to by the US Department of Energy, Nevada Operations Office (DOE\\/NV); the State of Nevada Division of Environmental Protection (NDEP); and the US Department of Defense (FFACO, 1996). The CAIP is a document that provides or references

1999-01-01

309

Ethical Aspects on Nuclear Waste. Some Salient Points Discussed at a Seminar on Ethical Action in the Face of Uncertainty in Stockholm, Sweden, September 8-9, 1987.  

National Technical Information Service (NTIS)

This is the translation of the outline of some salient points at the seminar in Swedish published in KASAM's annual report 1987. The chapters are as follows: Starting points; Different types of uncertainty - mankind's built-in limitations - Uncertainty ab...

1988-01-01

310

Analysis of formation of primary radiation-induced point defects in graphite under action of secondary neutrons and {pi}{sup -}-mesons generated in various channels of nuclear reactions upon graphite irradiation by 450-GeV protons  

SciTech Connect

A theoretical model is constructed and the rates of formation are calculated for primary radiation-induced point defects in graphite by secondary neutrons and {pi}{sup -}-mesons generated in various nuclear reaction channels upon irradiation of graphite by a 450-GeV proton beam. Calculations are performed using the ENDF-VII nuclear data base for energies of secondary particles lower than 150 MeV. It is shown that neutrons produce the highest generation rate of point radiation-induced defects in graphite (the rate of formation of defects under the action of neutrons is an order of magnitude higher than the corresponding value for {pi}{sup -}-mesons).

Ryazanov, A. I., E-mail: alexander.ryazanov@cern.ch; Semenov, E. V. [Russian Research Center Kurchatov Institute (Russian Federation)

2010-09-15

311

Analysis of formation of primary radiation-induced point defects in graphite under action of secondary neutrons and ?--mesons generated in various channels of nuclear reactions upon graphite irradiation by 450-GeV protons  

NASA Astrophysics Data System (ADS)

A theoretical model is constructed and the rates of formation are calculated for primary radiation-induced point defects in graphite by secondary neutrons and ?--mesons generated in various nuclear reaction channels upon irradiation of graphite by a 450-GeV proton beam. Calculations are performed using the ENDF-VII nuclear data base for energies of secondary particles lower than 150 MeV. It is shown that neutrons produce the highest generation rate of point radiation-induced defects in graphite (the rate of formation of defects under the action of neutrons is an order of magnitude higher than the corresponding value for ?--mesons).

Ryazanov, A. I.; Semenov, E. V.

2010-09-01

312

Labeling Points with Weights  

Microsoft Academic Search

Abstract. Annotating maps, graphs, and diagrams with pieces of text is an important step in information visualization that is usually referred to as label placement. We define nine label-placement models for labeling points with axis-parallel rectangles given a weight for each point. There are two groups; fixed-position models and slider models. We aim to maximize,the weight sum of those points

Sheung-hung Poon; Chan-su Shin; Tycho Strijk; Takeaki Uno; Alexander Wolff

2003-01-01

313

Photographic Fixing Bath.  

National Technical Information Service (NTIS)

The fixing bath has any desired composition of chemicals including sodium thiosulphate as the main dissolving agent for the undeveloped silver halide in the sensitive emulsion. The bath may also include control chemicals such as acetic acid, sodium sulphi...

M. Levy

1965-01-01

314

U Fix It  

NSDL National Science Digital Library

Ziff needs you to help him fix his buildings! With your tool bag, you will fix windows, doors, and roofs. Sounds easy right? It may not be as easy as you may think. You will need to use what you have learned in math class to make new ones that fit just right. You will get your own Cyberchase Master Builder certificate when the job is done!

2008-01-01

315

The Gallium Melting-Point Standard.  

National Technical Information Service (NTIS)

This Special Publication contains a series of papers published in Clinical Chemistry concerning the Bureau's temperature measurement system, the gallium melting-point as a thermometric fixed-point, how the gallium melting-point fits into the measurement s...

B. W. Mangum D. D. Thornton

1977-01-01

316

Could the relief of myofascial and\\/or low back pain by magnetic fields be explained by their action on trigger points  

Microsoft Academic Search

It is well recognized that a trigger point is a functional, rather than an anatomical, entity. It is known that a significant\\u000a fraction of both acute and chronic pain experience is myofascial in nature. This paper is aimed to discuss the potential of\\u000a using permanent magnets placed over the trigger points, which are associated with that referred pain, to be

Carlton F. Hazlewood; Marko S. Markov

2007-01-01

317

Study of the noise-induced transition and the exploration of the phase space for the Kuramoto-Sivashinsky equation using the minimum action method  

NASA Astrophysics Data System (ADS)

Noise-induced transition in the solutions of the Kuramoto-Sivashinsky (K-S) equation is investigated using the minimum action method derived from the large deviation theory. This is then used as a starting point for exploring the configuration space of the K-S equation. The particular example considered here is the transition between a stable fixed point and a stable travelling wave. Five saddle points, up to constants due to translational invariance, are identified based on the information given by the minimum action path. Heteroclinic orbits between the saddle points are identified. Relations between noise-induced transitions and the saddle points are examined.

Wan, X.; Zhou, X.; E, W.

2010-03-01

318

Fixed-ratio punishment.  

PubMed

Responses were maintained by a variable-interval schedule of food reinforcement. At the same time, punishment was delivered following every nth response (fixed-ratio punishment). The introduction of fixed-ratio punishment produced an initial phase during which the emission of responses was positively accelerated between punishments. Eventually, the degree of positive acceleration was reduced and a uniform but reduced rate of responding emerged. Large changes in the over-all level of responding were produced by the intensity of punishment, the value of the punishment ratio, and the level of food deprivation. The uniformity of response rate between punishments was invariant in spite of these changes in over-all rate and contrary to some plausible a priori theoretical considerations. Fixed-ratio punishment also produced phenomena previously observed under continuous punishment: warm-up effect and a compensatory increase. This type of intermittent punishment produced less rapid and less complete suppression than did continuous punishment. PMID:13965779

AZRIN, N H; HOLZ, W C; HAKE, D F

1963-04-01

319

Cannabidiol As a Putative Novel Therapy for Diabetic Retinopathy: A Postulated Mechanism of Action as an Entry Point for Biomarker-Guided Clinical Development  

PubMed Central

Diabetic retinopathy is a leading cause of blindness in the Western world. However, treatment options for diabetic retinopathy are limited and display poor efficacy with marked patient-to-patient variation in therapeutic outcomes. Discovery of new molecular entities acting on mechanistically novel biological pathways remains as one of the key research priorities in diabetic retinopathy. Moreover, given the variable success of the existing treatment modalities, a targeted and personalized drug development strategy could be more fruitful for rational and successful transition of preclinical discoveries to the clinical realm. This review is focused on cannabidiol, a non-psychoactive native cannabinoid, as an emerging and novel therapeutic modality based on systematic studies in animal models of inflammatory retinal diseases including diabetic retinopathy - one of the retinal diseases associated with vascular neuroinflammation. We present the postulated and preclinically documented novel mechanisms that may underlie cannabidiol mode of action in diabetic retinopathy. We discuss the interindividual variation in pharmacokinetic pathways as well as in the SLC29A1 gene, a molecular target for cannabidiol. We emphasize that the novel mode of action of cannabidiol and the previous failures with nontargeted interventions in diabetic retinopathy collectively demand a more rational and personalized clinical development strategy for compounds that have shown promise at the preclinical stage. Moreover, it is noteworthy that ophthalmology, as a medical specialty, has fewer examples (e.g., compared to oncology) of personalized medicine and biomarker applications thus far. Understanding the biological action of cannabidiol in preclinical studies is therefore a rational first step to proactively map the pertinent biomarker strategies in clinical proof of concept studies in diabetic retinopathy, and to allow advances at the hitherto neglected intersection of personalized medicine and ophthalmology.

Liou, GI; El-Remessy, AB; Ibrahim, AS; Caldwell, RB; Khalifa, YM; Gunes, A; Nussbaum, JJ

2010-01-01

320

Fixed site hydrogen storage. I - Applications impact  

Microsoft Academic Search

The potential applications and requirements for fixed site storage in a scenario of wide spread hydrogen use are examined and quantified. An envisioned hydrogen production\\/distribution\\/end-use cycle is scrutinized to identify the storage needs for both continuous and intermittent sources including solar. The most pressing need for storage is found to be at the distribution point, in concurrence with current natural

J. J. Iannucci; S. L. Robinson

1981-01-01

321

Fixed site hydrogen storage. 1: Applications impact  

Microsoft Academic Search

The potential applications and requirements for fixed site storage in a scenario of wide spread hydrogen use are examined and quantified. An envisioned hydrogen production\\/distribution\\/end-use cycle is scrutinized to identify the storage needs for both continuous and intermittent sources including solar. The most pressing need for storage is found to be at the distribution point, in concurrence with current natural

J. J. Iannucci; S. L. Robinson

1979-01-01

322

Applications analysis of fixed site hydrogen storage  

Microsoft Academic Search

The potential applications and requirements for fixed site storage in a scenario of wide spread hydrogen use are examined and quantified. An envisioned hydrogen production\\/distribution\\/end-use cycle is scrutinized to identify the storage needs for both continuous and intermittent sources including solar. The most pressing need for storage is found to be at the distribution point, in concurrence with current natural

J. J. Iannucci; S. L. Robinson

1979-01-01

323

Point specificity in acupuncture  

PubMed Central

The existence of point specificity in acupuncture is controversial, because many acupuncture studies using this principle to select control points have found that sham acupoints have similar effects to those of verum acupoints. Furthermore, the results of pain-related studies based on visual analogue scales have not supported the concept of point specificity. In contrast, hemodynamic, functional magnetic resonance imaging and neurophysiological studies evaluating the responses to stimulation of multiple points on the body surface have shown that point-specific actions are present. This review article focuses on clinical and laboratory studies supporting the existence of point specificity in acupuncture and also addresses studies that do not support this concept. Further research is needed to elucidate the point-specific actions of acupuncture.

2012-01-01

324

Point specificity in acupuncture.  

PubMed

The existence of point specificity in acupuncture is controversial, because many acupuncture studies using this principle to select control points have found that sham acupoints have similar effects to those of verum acupoints. Furthermore, the results of pain-related studies based on visual analogue scales have not supported the concept of point specificity. In contrast, hemodynamic, functional magnetic resonance imaging and neurophysiological studies evaluating the responses to stimulation of multiple points on the body surface have shown that point-specific actions are present. This review article focuses on clinical and laboratory studies supporting the existence of point specificity in acupuncture and also addresses studies that do not support this concept. Further research is needed to elucidate the point-specific actions of acupuncture. PMID:22373514

Choi, Emma M; Jiang, Fang; Longhurst, John C

2012-02-28

325

Angular maneuver, an optimum one from the point of its quick action maximum for a case of a flat turn around the spatial axis  

NASA Astrophysics Data System (ADS)

The paper deals with the problem of optimizing a non-linear control system cum non-zero initial and final conditions and, in particular the problem of obtaining analytical interrelationships determining the phase trajectories and working moments of control. Here, the optimality shall be understood in the sense of quick action or a minimum of energy expenditure. As a controlled body, a flying spacecraft of the 'HOPE' type is considered. A case of a flat turn around the spatial axis, which provides for new possibilities of improving the qualitative indexes of the angular maneuver control system is scrutinized. The approaches described here for solving the problem of time-optimal control can be adapted to systems having fuel-conserving requirements. The paper offers methods of solving fuel-conserving or time-optimal problems when switching the spacecraft from an arbitrary initial position to the arbitrary final one by angle and angular velocity. The results of modeling are cited.

Mitroshin, Edward; Gorbatenko, Valery; Kostenko, Marina; Makovlev, Vyacheslav

326

Fixed Resistor Placement  

NSDL National Science Digital Library

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.

2012-10-02

327

23. DETAIL VIEW OF FIXED SPAN SUBSTRUCTURE, EAST SPAN, SHOWING ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

23. DETAIL VIEW OF FIXED SPAN SUBSTRUCTURE, EAST SPAN, SHOWING CONDITION OF GRANITE PIERS AND PILES OF ADJACENT PIER, LOOKING SOUTHEAST - Congress Street Bascule Bridge, Spanning Fort Point Channel at Congress Street, Boston, Suffolk County, MA

328

Fixed target facility at the SSC  

SciTech Connect

The question of whether a facility for fixed target physics should be provided at the SSC must be answered before the final technical design of the SSC can be completed, particularly if the eventual form of extraction would influence the magnet design. To this end, an enthusiastic group of experimentalists, theoreticians and accelerator specialists have studied this point. The accelerator physics issues were addressed by a group led by E. Colton whose report is contained in these proceedings. The physics addressable by fixed target was considered by many of the Physics area working groups and in particular by the Structure Function Group. This report is the summary of the working group which considered various SSC fixed target experiments and determined which types of beams and detectors would be required. 13 references, 5 figures.

Loken, S.C.; Morfin, J.G.

1985-01-01

329

Comprehensive assessment of the regulons controlled by the FixLJ-FixK2-FixK1 cascade in Bradyrhizobium japonicum.  

PubMed

Symbiotic N(2) fixation in Bradyrhizobium japonicum is controlled by a complex transcription factor network. Part of it is a hierarchically arranged cascade in which the two-component regulatory system FixLJ, in response to a moderate decrease in oxygen concentration, activates the fixK(2) gene. The FixK(2) protein then activates not only a number of genes essential for microoxic respiration in symbiosis (fixNOQP and fixGHIS) but also further regulatory genes (rpoN(1), nnrR, and fixK(1)). The results of transcriptome analyses described here have led to a comprehensive and expanded definition of the FixJ, FixK(2), and FixK(1) regulons, which, respectively, consist of 26, 204, and 29 genes specifically regulated in microoxically grown cells. Most of these genes are subject to positive control. Particular attention was addressed to the FixK(2)-dependent genes, which included a bioinformatics search for putative FixK(2) binding sites on DNA (FixK(2) boxes). Using an in vitro transcription assay with RNA polymerase holoenzyme and purified FixK(2) as the activator, we validated as direct targets eight new genes. Interestingly, the adjacent but divergently oriented fixK(1) and cycS genes shared the same FixK(2) box for the activation of transcription in both directions. This recognition site may also be a direct target for the FixK(1) protein, because activation of the cycS promoter required an intact fixK(1) gene and either microoxic or anoxic, denitrifying conditions. We present evidence that cycS codes for a c-type cytochrome which is important, but not essential, for nitrate respiration. Two other, unexpected results emerged from this study: (i) specifically FixK(1) seemed to exert a negative control on genes that are normally activated by the N(2) fixation-specific transcription factor NifA, and (ii) a larger number of genes are expressed in a FixK(2)-dependent manner in endosymbiotic bacteroids than in culture-grown cells, pointing to a possible symbiosis-specific control. PMID:18689489

Mesa, Socorro; Hauser, Felix; Friberg, Markus; Malaguti, Emmanuelle; Fischer, Hans-Martin; Hennecke, Hauke

2008-08-08

330

Event parameters - fixed target  

SciTech Connect

This subgroup has focussed on detectors for fixed target experiments which have full azimuthal coverage. The general scope of the working group was to consider (1) the configuration of an idealized detector, and (2) various configurations of practical detectors that could be implemented on a relatively short time scale. The second category includes possible upgrades and modifications of existing experimental facilities. Beams of both 15 GeV/A sulphur at the AGS and 200 GeV/A oxygen at the SPS were considered.

Poskanzer, A.; Ritter, H.G.; Ludewigt, B.; Foley, K.; Borenstein, S.; Platner, E.; Love, W.; Keane, D.; Plasil, F.

1984-06-15

331

A Fast Fixed-Point Algorithm for Independent Component Analysis  

Microsoft Academic Search

We introduce a novel fast algorithm for independent component analysis, which can be used for blind source separation and feature extraction. We show how a neural network learning rule can be transformed into a fixedpoint iteration, which provides an algorithm that is very simple, does not depend on any user-defined parameters, and is fast to converge to the most accurate

Aapo Hyvärinen; Erkki Oja

1997-01-01

332

A new wide dynamic range fixed point ADC for FPAs  

Microsoft Academic Search

CMOS image sensor system has several clear advantages over CCD image sensor system: selective readout, low power, small size, high frame rate, on-chip functionality, and low cost. However CCD image system still dominates over digital camera market, because the CMOS image system has a poor dynamic range (DR) and peak signal-to-noise ratio (SNR). In this paper, we propose a new

Jehyuk Rhee; Youngjoong Joo

2002-01-01

333

Globally attracting fixed points in higher order discrete population models  

Microsoft Academic Search

We address the global stability properties of the positive equilibrium in a general delayed discrete population model. Our results are used to investigate in detail a well-known model for baleen whale populations.

Hassan A. El-Morshedy; Eduardo Liz

2006-01-01

334

Globally attracting fixed points in higher order discrete population models.  

PubMed

We address the global stability properties of the positive equilibrium in a general delayed discrete population model. Our results are used to investigate in detail a well-known model for baleen whale populations. PMID:16865365

El-Morshedy, Hassan A; Liz, Eduardo

2006-07-25

335

Infrared Behavior and Fixed Points in Landau-Gauge QCD  

NASA Astrophysics Data System (ADS)

We investigate the infrared behavior of gluon and ghost propagators in Landau-gauge QCD by means of an exact renormalization group equation. We explain how, in general, the infrared momentum structure of Green functions can be extracted within this approach. An optimization procedure is devised to remove residual regulator dependences. In Landau-gauge QCD this framework is used to determine the infrared leading terms of the propagators. The results support the Kugo-Ojima confinement scenario. Possible extensions are discussed.

Pawlowski, Jan M.; Litim, Daniel F.; Nedelko, Sergei; von Smekal, Lorenz

2004-10-01

336

Fixed point Dual Carrier Modulation performance for wireless USB  

Microsoft Academic Search

Dual Carrier Modulation (DCM) is currently used as the higher data rate modulation scheme for Multiband Orthogonal Frequency Division Multiplexing (MB-OFDM) in the ECMA-368 defined Ultra-Wideband (UWB) radio platform. ECMA-368 has been chosen as the physical radio platform for many systems including Wireless USB (W-USB), Bluetooth 3.0 and Wireless HDMI; hence ECMA-368 is an important issue to consumer electronics and

Runfeng Yang; R. Simon Sherratt

2009-01-01

337

On the complexity of 2D discrete fixed point problem  

Microsoft Academic Search

We study a computational complexity version of the 2D Sperner problem, which states that any three coloring of vertices of a triangulated triangle, satisfying some boundary conditions, will have a trichromatic triangle. In introducing a complexity class PPAD, Papadimitriou [C.H. Papadimitriou, On graph-theoretic lemmata and complexity classes, in: Proceedings of the 31st Annual Symposium on Foundations of Computer Science, 1990,

Xi Chen; Xiaotie Deng

2009-01-01

338

Final coalgebras as greatest fixed points in ZF set theory  

Microsoft Academic Search

A special final coalgebra theorem, in the style of Aczel (1988), is proved within standard Zermelo-Fraenkel set theory. Aczel's Anti-Foundation Axiom is replaced by a variant definition of function that admits non-well-founded constructions. Variant ordered pairs and tuples, of possibly infinite length, are special cases of variant functions. Analogues of Aczel's solution and substitution lemmas are proved in the style

Lawrence C. Paulson

1999-01-01

339

Covering mappings in metric spaces and fixed points  

Microsoft Academic Search

We consider metric spaces X and Y with metrics ? X and ? Y , respectively. Before stating the main results of this paper, we recall two known assertions. The first of them is the contraction mapping principle, which says that if a space X is complete, then any self-mapping of X satisfying the Lipschitz condition with Lipschitz constant less

A. V. Arutyunov

2007-01-01

340

How to read floating point numbers accurately  

Microsoft Academic Search

Converting decimal scientific notation into binary floating point is nontrivial, but this conversion can be performed with the best possible accuracy without sacrificing efficiency.Consider the problem of converting decimal scientific notation for a number into the best binary floating point approximation to that number, for some fixed precision. This problem cannot be solved using arithmetic of any fixed precision. Hence

William D. Clinger

2004-01-01

341

How to read floating point numbers accurately  

Microsoft Academic Search

Consider the problem of converting decimal scientific notation for a number into the best binary floating point approximation to that number, for some fixed precision. This problem cannot be solved using arithmetic of any fixed precision. Hence the IEEE Standard for Binary Floating-Point Arithmetic does not require the result of such a conversion to be the best approximation.This paper presents

William D. Clinger

1990-01-01

342

Colligative Properties of Solutions: I. Fixed Concentrations  

Microsoft Academic Search

Using the formalism of rigorous statistical mechanics, we study the phenomena of phase separation and freezing-point depression upon freezing of solutions. Specifically, we devise an Ising-based model of a solvent--solute system and show that, in the ensemble with a fixed amount of solute, a macroscopic phase separation occurs in an interval of values of the chemical potential of the solvent.

Kenneth S. Alexander; Marek Biskup; Lincoln Chayes

2005-01-01

343

Standard Reference Material 1744: Aluminum Freezing-Point Standard.  

National Technical Information Service (NTIS)

The freezing point of aluminum (660.323 deg. C) is a defining fixed point of the International Temperature Scale of 1990 (ITS-90). Realization of this freezing point is performed using a fixed-point cell containing high purity (greater than or equal to 99...

G. F. Strouse

1995-01-01

344

Understanding affirmative action.  

PubMed

Affirmative action is a controversial and often poorly understood policy. It is also a policy that has been widely studied by social scientists. In this review, we outline how affirmative action operates in employment and education settings and consider the major points of controversy. In addition, we detail the contributions of psychologists and other social scientists in helping to demonstrate why affirmative action is needed; how it can have unintended negative consequences; and how affirmative action programs can be most successful. We also review how psychologists have examined variations in people's attitudes toward affirmative action, in part as a means for testing different theories of social behavior. PMID:16318608

Crosby, Faye J; Iyer, Aarti; Sincharoen, Sirinda

2006-01-01

345

Active microrheology: Fixed-velocity versus fixed-force  

NASA Astrophysics Data System (ADS)

In active microrheology, a probe particle is driven by an external force through a complex medium and its motion studied in order to infer properties of the embedding material. It is conducted in two limiting forms: either the probe is propelled by a fixed force, as with magnetic tweezers, or it is driven at a fixed velocity, as with optical tweezers. Recent work has shown that the mean probe motion can be interpreted as an effective material viscosity, but that this viscosity depends on whether the fixed-force or fixed-velocity mode is employed. We compute the effective viscosity probed by fixed-velocity active microrheology of a dilute colloidal dispersion. A comparison is made between this new result and the effective viscosity probed in the fixed-force mode. In the absence of hydrodynamic interactions, the particle-phase contributions to the effective viscosity for the two modes differ by exactly a factor of two. A simple scaling argument has been previously advanced to rationalize this difference: in the fixed-force mode, the probe is free to diffuse, and thus the relaxation time scale is set by the relative diffusivity between probe and bath. However, in the fixed-velocity mode, thermal motion of the probe particle is ``frozen out'' because the probe cannot diffuse; the relaxation rate is thus halved. The ratio of the two rates is independent of how quickly the probe particle is driven through the suspension--the extent and shape of microstructural deformation is the same for the two cases. In contrast, when the suspended particles interact hydrodynamically, the distortions to the suspension microstructure in the fixed-velocity versus fixed-force modes differ. We show that, depending on the strength of the hydrodynamic interactions, the ratio of the fixed-velocity to the fixed-force microstructural contributions to the effective viscosity may be as small as 1.3, and only approaches 2.0 when hydrodynamic interactions among the particles are negligibly weak. While this ratio varies both as a function of the strength of the deformation imposed and of the strength of hydrodynamic interactions, the fixed-velocity effective viscosity agrees qualitatively with that already measured for the fixed-force mode: the colloidal dispersion thins in the limit of weak hydrodynamic interactions; and it first thins and then thickens in the limit of strong hydrodynamic interactions, as the strength of deformation increases, recovering characteristics of shear-(force-) thinning and thickening well known in colloidal dispersions. The agreement between the two, and with traditional macrorheological approaches, shows that both fixed-force and fixed-velocity provide a useful tool for the interrogation of complex fluids.

Swan, James W.; Zia, Roseanna N.

2013-08-01

346

Fixed-Lag Smoothing using Sequential Importance Sampling1  

Microsoft Academic Search

SUMMARY In this paper we present methods for fixed-lag smoothing using Sequential Importance sampling (SIS) for state space models with unknown parameters. Sequential processing using Monte Carlo simulation is an area of growing interest for many engineering and statistical applicatio ns where data arrive point by point rather than in a batch. The methods presented here are related to the

TIM C. CLAPP; SIMON J. GODSILL

1999-01-01

347

U Fix It with Ziff  

NSDL National Science Digital Library

In this online math game from Cyberchase, learners use measurement to help Ziff fix up his house. Learners use a ruler to make measurements and then cut new windows, doors, etc. to make fixes to the house. There are six rounds in this game.

Wnet.org

2011-01-01

348

Fixed series compensation monitoring system  

Microsoft Academic Search

Fixed Series Compensation (FSC) employs capacitors to compensate the inductive reactance of transmission lines, being a highly effective and economical means of improving power transfer. A Fixed Series Compensation Monitoring System has as objective the knowledge of the actual physical state of this FACTS (Flexible AC Transmission Systems) system and diagnose the evolution of components damage, so that it is

A. L. P. de Oliveira

2008-01-01

349

Gauge fixing of stringlike models via OSp(D/2)  

SciTech Connect

Within the formalism of OSrho(D/2) supersymmetry, wherein extended BRST transformations correspond to supertranslations, the authors fix the gauge of bosonic stringlike models in the form, par. deltag = 0, ..sqrt..g = rho. The action has no propagating or interacting conformal ghosts and the Srho(2) symmetry between the ghosts is manifest.

Delbourgo, R.; Jarvis, P.D.; Zhang, R.B.; Thompson, G.

1988-02-01

350

Total effective dose equivalent associated with fixed uranium surface contamination  

SciTech Connect

This report provides the technical basis for establishing a uranium fixed-contamination action level, a fixed uranium surface contamination level exceeding the total radioactivity values of Appendix D of Title 10, Code of Federal Regulations, part 835 (10CFR835), but below which the monitoring, posting, and control requirements for Radiological Areas are not required for the area of the contamination. An area of fixed uranium contamination between 1,000 dpm/100 cm{sup 2} and that level corresponding to an annual total effective dose equivalent (TEDE) of 100 mrem requires only routine monitoring, posting to alert personnel of the contamination, and administrative control. The more extensive requirements for monitoring, posting, and control designated by 10CFR835 for Radiological Areas do not have to be applied for these intermediate fixed-contamination levels.

Bogard, J.S.; Hamm, R.N.; Ashley, J.C.; Turner, J.E.; England, C.A.; Swenson, D.E.; Brown, K.S.

1997-04-01

351

Action Theory and Literary Interpretation  

Microsoft Academic Search

This article relates the logic of literary interpretation to the logic of administrative action theory. It offers criteria for validating interpretations of administrative action. It shows how action theory can be rescued from misplaced claims of subjectivism by locating the meaning of an act with the intention of the actor. It also points out that both the meaning and the

Jay D. White

1987-01-01

352

CP{sup N-1} models at a Lifshitz point  

SciTech Connect

We consider CP{sup N-1} models in d+1 dimensions around Lifshitz fixed points with dynamical critical exponent z, in the large-N expansion. It is shown that these models are asymptotically free and dynamically generate a mass for the CP{sup N-1} fields for all d=z. We demonstrate that, for z=d=2, the initially nondynamical gauge field acquires kinetic terms in a way similar to usual CP{sup N-1} models in 1+1 dimensions. Lorentz invariance emerges generically in the low-energy electrodynamics, with a nontrivial dielectric constant given by the inverse mass gap and a magnetic permeability which has a logarithmic dependence on scale. At a special multicritical point, the low-energy electrodynamics also has z=2, and an essentially singular dependence of the effective action on B={epsilon}{sub ij}{partial_derivative}{sub i}A{sub j}.

Das, Sumit R.; Murthy, Ganpathy [Department of Physics and Astronomy, University of Kentucky, Lexington, Kentucky 40506 (United States)

2009-09-15

353

Fixing structure of battery module  

US Patent & Trademark Office Database

A fixing structure of battery module for fixing a battery module in an electronic device is proposed. The fixing structure includes a first lid and a second lid, which are formed on a surface of the electronic device, wherein the first lid is formed with a first fastening part, and the second lid is formed with a second fastening part for being engaged with the first fastening part; a mounting cavity formed in the electronic device at a position corresponding to the second lid; a first locking part formed on the second lid; and a second locking part formed on the battery module, for being coupled to the first locking part so as to fasten the battery module to the second lid. When the first and second lids are coupled together by the first and second fastening parts, the battery module fastened to the second lid is received in the mounting cavity and fixed in the electronic device.

Hsu; Cheng-Chung (Taipei, TW); Lee; Chin-Cheng (Taipei, TW)

2010-05-11

354

75 FR 70704 - Federal Copyright Protection of Sound Recordings Fixed Before February 15, 1972  

Federal Register 2010, 2011, 2012, 2013

...LIBRARY OF CONGRESS Copyright Office [Docket No. 2010-4] Federal Copyright Protection of Sound Recordings Fixed Before February 15, 1972 AGENCY: Copyright Office, Library of Congress. ACTION: Notice...

2010-11-18

355

76 FR 26769 - Federal Copyright Protection of Sound Recordings Fixed Before February 15, 1972  

Federal Register 2010, 2011, 2012, 2013

...LIBRARY OF CONGRESS Copyright Office [Docket No. 2010-4] Federal Copyright Protection of Sound Recordings Fixed Before February 15, 1972 AGENCY: Copyright Office, Library of Congress. ACTION: Notice...

2011-05-09

356

75 FR 74749 - Federal Copyright Protection of Sound Recordings Fixed Before February 15, 1972  

Federal Register 2010, 2011, 2012, 2013

...LIBRARY OF CONGRESS Copyright Office [Docket No. 2010-4] Federal Copyright Protection of Sound Recordings Fixed Before February 15, 1972 AGENCY: Copyright Office, Library of Congress. ACTION: Notice...

2010-12-01

357

The triple point of krypton  

NASA Astrophysics Data System (ADS)

Phase transitions of pure substances provide the key reference temperatures, otherwise known as "defining fixed points", of the International Temperature Scale. At temperatures below the triple point of mercury (234.3156 K), the substances involved are gases at room temperature and include the triple points of hydrogen (13.8033 K), neon (24.5561 K), oxygen (54.3584 K) and argon (83.8058 K). The Consultative Committee for Thermometry also provides a list of "secondary reference points" whose quality approaches (or is equivalent to) that of the defining fixed points of the ITS Here, we report direct measurements of the triple point of krypton on the ITS-90, review the historical measurements that CCT WG2 relied upon for its 1996 assessment, and demonstrate that the triple point of krypton is a "first quality" secondary reference point. Based on our measurements, the temperature of the triple point of krypton is 115.7755 K +/- 0.3 mK (k=1).

Hill, K. D.

2013-09-01

358

Point Groups  

NSDL National Science Digital Library

This exercise involves identifying symmetry in crystals and using that information to assign crystals to crystal systems and point groups. Students examine cardboard models and wooden blocks and fill their symmetry elements into a table. Then they figure out what what crystal system and point group each sample belongs to and fill in another table.

Perkins, Dexter

359

Cytological and biochemical characterization of the in situ endonuclease digestion of fixed Tenebrio molitor chromosomes  

Microsoft Academic Search

Cytological and biochemical experiments were undertaken in order to characterize the action of several restriction enzymes on fixed chromosomes of Tenebrio molitor (Coleoptera). EcoRI cuts the satellite DNA of this organism into suunit monomers of 142 bp in naked DNA and acts on fixed chromosomes cleaving and extracting these tandemly repeated sequences present in median centromeric heterochromatin. AluI, in contrast,

Carlos Juan; Jaime Gosfilvez; Roberto Mezzanotte; Eduard Petitpierre

1991-01-01

360

Procrastination by pigeons with fixed-interval response requirements.  

PubMed

Two experiments studied the phenomenon of procrastination, in which pigeons chose a larger, more delayed response requirement over a smaller, more immediate response requirement. The response requirements were fixed-interval schedules that did not lead to an immediate food reinforcer, but that interrupted a 55-s period in which food was delivered at random times. The experiments used an adjusting-delay procedure in which the delay to the start of one fixed-interval requirement was varied over trials to estimate an indifference point--a delay at which the two alternatives were chosen about equally often. Experiment 1 found that as the delay to a shorter fixed-interval requirement was increased, the adjusting delay to a longer fixed-interval requirement also increased, and the rate of increase depended on the duration of the longer fixed-interval requirement. Experiment 2 found a strong preference for a fixed delay of 10 s to the start of a fixed-interval requirement compared to a mixed delay of either 0 or 20 s. The results help to distinguish among different equations that might describe the decreasing effectiveness of a response requirement with increasing delay, and they suggest that delayed reinforcers and delayed response requirements have symmetrical but opposite effects on choice. PMID:9540230

Mazur, J E

1998-03-01

361

Procrastination by pigeons with fixed-interval response requirements.  

PubMed Central

Two experiments studied the phenomenon of procrastination, in which pigeons chose a larger, more delayed response requirement over a smaller, more immediate response requirement. The response requirements were fixed-interval schedules that did not lead to an immediate food reinforcer, but that interrupted a 55-s period in which food was delivered at random times. The experiments used an adjusting-delay procedure in which the delay to the start of one fixed-interval requirement was varied over trials to estimate an indifference point--a delay at which the two alternatives were chosen about equally often. Experiment 1 found that as the delay to a shorter fixed-interval requirement was increased, the adjusting delay to a longer fixed-interval requirement also increased, and the rate of increase depended on the duration of the longer fixed-interval requirement. Experiment 2 found a strong preference for a fixed delay of 10 s to the start of a fixed-interval requirement compared to a mixed delay of either 0 or 20 s. The results help to distinguish among different equations that might describe the decreasing effectiveness of a response requirement with increasing delay, and they suggest that delayed reinforcers and delayed response requirements have symmetrical but opposite effects on choice.

Mazur, J E

1998-01-01

362

Fixed-ratio punishment1  

PubMed Central

Responses were maintained by a variable-interval schedule of food reinforcement. At the same time, punishment was delivered following every nth response (fixed-ratio punishment). The introduction of fixed-ratio punishment produced an initial phase during which the emission of responses was positively accelerated between punishments. Eventually, the degree of positive acceleration was reduced and a uniform but reduced rate of responding emerged. Large changes in the over-all level of responding were produced by the intensity of punishment, the value of the punishment ratio, and the level of food deprivation. The uniformity of response rate between punishments was invariant in spite of these changes in over-all rate and contrary to some plausible a priori theoretical considerations. Fixed-ratio punishment also produced phenomena previously observed under continuous punishment: warm-up effect and a compensatory increase. This type of intermittent punishment produced less rapid and less complete suppression than did continuous punishment.

Azrin, N. H.; Holz, W. C.; Hake, D. F.

1963-01-01

363

Mac FixIt Guides  

NSDL National Science Digital Library

The iFixIt guides are extremely helpful to computer repair technicians who would like to be able to fix Apple brand computers as well as PCs. The guides included on the site are mainly dedicated to Apple laptops, including MacBooks, PowerBooks, and iBooks, but also include a few guides pertaining to the Mac Mini. There are numerous guides to choose from, all organized by computer type, computer specifications, and what the repairperson would like to accomplish. The guides are extremely easy to follow and contain detailed pictures and diagrams, which are very helpful. Most of the guides are also downloadable. The guides include lists of tools and links to purchase the tools if the user doesn�t have them. All of the information on iFixIt is free and no login is required.

2006-12-31

364

Fixative for fixing biological materials  

US Patent & Trademark Office Database

A fixative for fixing biological materials contains a depot agent, preferably a polyamine and especially hexamethylenetetramine, which reacts chemically with positively charged ions, especially H+ from an acid, while forming a fixative, where the fixative is an aldehyde and especially formaldehyde, which in turn reacts chemically with the biological material to be fixed in order to fix it and is consumed in doing so. By adjusting the pH of a solution containing the depot agent, a chemical equilibrium reaction occurs between the depot agent, fixative and biological material, so that just as much fixative is continuously formed as can be immediately consumed by the biological material. With that, the fixative, and especially the hazardous formaldehyde, cannot escape. Thus, an externally formaldehyde-free fixative that at the same time has the excellent fixative properties of formaldehyde is created.

Szabados; Andreas (Grunwald, DE); Gerigk; Roberto (Muhldorf a. Inn, DE)

2011-03-29

365

Fixed Schedules Can Support 21st-Century Skills  

ERIC Educational Resources Information Center

The common belief among school librarians is that a flexibly scheduled school library program as opposed to a fixed schedule program is the best choice. After all, there are distinct advantages to the flexible program: students are served at the point of need, skills are not taught in isolation, and collaborative lessons are developed with…

Formanack, Gail; Pietsch, Laura

2011-01-01

366

Accuracy analysis of fixed voltage setpoint indices for voltage stability  

Microsoft Academic Search

There are many voltage stability indices for voltage security assessment and calculating stable margins from operating points to voltage instability at each load bus. Among them, one type of indices based on fixed voltage setpoint is applied in practice. Previous research has proved inaccuracy of these indices with the P-V curve method. This paper aims to verify the accuracy of

Sun Huadong; Tang Yong; Bu Guangquan

2010-01-01

367

Response of Fixed Speed Wind Turbines to System Frequency Disturbances  

Microsoft Academic Search

This paper analyzes the impact of system frequency variations on the steady-state operation point of fixed speed induction generators used in wind turbine generation systems (WTGS). An analytic method to predict the values of angular speed, torque and current during and after a frequency disturbance is presented. The proposed method as well permits to establish the operation limits in order

Andreas Sumper; Oriol Gomis-Bellmunt; Antoni Sudria-Andreu; Roberto Villafafila-Robles; Joan Rull-Duran

2009-01-01

368

14. DETAIL VIEW, LOOKING SOUTHEAST, OF FIXED SPAN SUPERSTRUCTURE AT ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

14. DETAIL VIEW, LOOKING SOUTHEAST, OF FIXED SPAN SUPERSTRUCTURE AT FENDER SYSTEM, SHOWING MOVABLE SPAN LOCKS IN CLOSED POSITION; NOTE CHANNEL LIGHT, CENTER LOCKING POINT AND SLIDER TO LEFT OF IT (taken in March 1984) - Sharptown Bridge, Spanning Nanticoke River, State Route 313, Sharptown, Wicomico County, MD

369

[Orthodontic fixed retainer: fix or not fix? that is the question].  

PubMed

Orthodontic fixed retainer is widely used, as an orthodontic retention appliance, for nearly four decades. It answers the need for prolonged retention with minimum patient compliance. The effectiveness of fixed retainers was compared to other retention devices in several studies, and was found as effective as removable appliances. But, further high quality research is still needed. A bonded fixed retainer was suspected as an obstacle that impedes the patient's ability to keep satisfactory oral hygiene. But research failed to prove the influence of fixed retainers on periodontal health or white spot lesion occurrence as clinically significant. The definite downsides of fixed retainer are the risk of retainer breakage, and unwanted tooth movements. A typical tooth movement can appear even without a retainer breakage, including a change of torque of a mandibular incisor or skewing of the anterior mandibular arch segment. Both the dentist and the orthodontist are encouraged to be familiarized with these possible side effects, recognized them as soon as possible, and consider changing the retention protocol, when appropriate. PMID:23256395

Yitschaky, O; Yitschaky, M; Sagi, H Katz

2012-07-01

370

Braid group action and quantum affine algebras  

Microsoft Academic Search

We lift the lattice of translations in the extended affine Weyl group to a braid group action on the quantum affine algebra. This action fixes the Heisenberg subalgebra pointwise. Loop-like generators of the algebra are obtained which satisfy the relations of Drinfel'd's new realization. Coproduct formulas are given and a PBW type basis is constructed.

Jonathan Beck

1994-01-01

371

Identifying Linux bug fixing patches  

Microsoft Academic Search

In the evolution of an operating system there is a continuing tension between the need to develop and test new features, and the need to provide a stable and secure execution environment to users. A compromise, adopted by the developers of the Linux kernel, is to release new versions, including bug fixes and new features, frequently, while maintaining some older

Yuan Tian; Julia Lawall; David Lo

2012-01-01

372

Fixed drug eruption to tartrazine.  

PubMed

An 11-year-old girl with a recurrent fixed drug eruption to tartrazine on the dorsum of the left hand is presented. Oral provocation tests to both the suspected food, an artificially coloured cheese crisp, and to tartrazine were positive. This case highlights fire need to consider artificial flavours, colours and preservatives as potential culprits in classic drug eruptions. PMID:9431719

Orchard, D C; Varigos, G A

1997-11-01

373

Fixed Costs and Hours Constraints  

ERIC Educational Resources Information Center

|Hours constraints are typically identified by worker responses to questions asking whether they would prefer a job with more hours and more pay or fewer hours and less pay. Because jobs with different hours but the same rate of pay may be infeasible when there are fixed costs of employment or mandatory overtime premia, the constraint in those…

Johnson, William R.

2011-01-01

374

Fixed Costs and Hours Constraints  

ERIC Educational Resources Information Center

Hours constraints are typically identified by worker responses to questions asking whether they would prefer a job with more hours and more pay or fewer hours and less pay. Because jobs with different hours but the same rate of pay may be infeasible when there are fixed costs of employment or mandatory overtime premia, the constraint in those…

Johnson, William R.

2011-01-01

375

Dew Point  

NSDL National Science Digital Library

Determine the dew point temperature for your classroom through a hands-on experiment. Use humidity and temperature probes to investigate the temperature at which it would rain in your classroom! Learn about water density and the conditions necessary to produce fog or rain.

Consortium, The C.

2011-12-13

376

Impurity Effect in Silver-Point Realization  

NASA Astrophysics Data System (ADS)

CCT-WG1 has recommended the sum of individual estimates (SIE) method to correct for the influence of impurities on the realization of temperature fixed points when a detailed impurity analysis is available. The method to estimate the uncertainty of the SIE has also been reported. On the other hand, most cells are fabricated from commercial fixed-point metals that often have no detailed impurity analysis, so the SIE calculation is impossible in that case. Due to this circumstance, and with the focus on the silver fixed point, a new fixed-point cell was fabricated in such a way that a portion of the silver ingot used was extractable during the silver casting. This portion was then analyzed by glow discharge mass spectrometry (GDMS), and the result used to calculate the SIE correction and its uncertainty. Temperature measurements during melting and freezing were collected using new and existing silver fixed-point cells under various conditions. These measurements were used to derive the slope of the silver freezing curve, from which the effect of impurities was evaluated by thermal analysis. The difference between the SIE and the thermal analysis method was evaluated to check the inaccuracy of the thermal analysis from the SIE point of view.

Widiatmo, J. V.; Harada, K.; Yamazawa, K.; Arai, M.

2008-02-01

377

Integrating assist feature print fixing with OPC  

NASA Astrophysics Data System (ADS)

A challenge in model-based assist feature placement is to find optimal placements while satisfying mask rules and preventing AF printing. There are numerous strategies for achieving this ranging from fully rule-based methods to pixel-based inversion. Our proposed solution is to identify the optimal locations of assist features using modeling information based strictly on optics and resist stack optical characteristics. Once these positions have been found, preliminary AFs can be placed. At this point suggested sizes and shapes can be identified, although these can later be modified. In a later step, MRC cleanup, printability fixing, and main-pattern OPC can be performed simultaneously. This has the advantage of allowing the use of the full process model to predict the location of OPC edges accurately, and use calibrated or 3d mask models to determine assist feature printing behavior. This correction is done while maintaining MRC constraints. In this flow, an AF placement field, generated from the pre-OPC target patterns, can be used to provide accurate guidance on how to move assist features to get the most benefit while keeping other constraints in mind. Using this method, a range of printability fixing strategies, guided by placement benefits, is available. We present data showing that the benefit of AF placements can be determined from optical parameters, on target (non-OPC) data, and that this method leads to beneficial yet compliant masks.

Barnes, Levi D.; Poonawala, Amyn; Painter, Benjamin D.; Jost, Andrew M.; Takei, Tj; Li, Yong

2009-03-01

378

New NIST Mercury Triple-Point Cells.  

National Technical Information Service (NTIS)

Six new Hg triple-point (TP) cells (234.3156 K) were manufactured in the NIST PRT Laboratory for use in the realization of the International Temperature Scale of 1990 (ITS-90). The fixed-point cells consisted of both glass and stainless steel designs with...

G. F. Strouse J. Lippiatt

2008-01-01

379

The L1 Lagrangian Point  

NSDL National Science Digital Library

Lagrangian points of the Sun-Earth system are points in space where a spacecraft may maintain a fixed position relative to them (the Earth-Moon system also has such points). The L1 point, sunward of Earth by about 4 times the distance of the Moon, has been used by several NASA spacecraft. The L2 point, equally far on the nightward side, is where the "Microwave Anisotropy Probe" (launched 6.30.2001) and the "Next Generation Space Telescope" are to be placed, and L4 and L5 also have interesting uses. Calculations of these equilibria for L1 are given here; the one for L2 is similar - no calculus, but a great deal of algebra!

Stern, David

2002-06-30

380

Variable delivery, fixed displacement pump  

DOEpatents

A variable delivery, fixed displacement pump comprises a plurality of pistons reciprocated within corresponding cylinders in a cylinder block. The pistons are reciprocated by rotation of a fixed angle swash plate connected to the pistons. The pistons and cylinders cooperate to define a plurality of fluid compression chambers each have a delivery outlet. A vent port is provided from each fluid compression chamber to vent fluid therefrom during at least a portion of the reciprocal stroke of the piston. Each piston and cylinder combination cooperates to close the associated vent port during another portion of the reciprocal stroke so that fluid is then pumped through the associated delivery outlet. The delivery rate of the pump is varied by adjusting the axial position of the swash plate relative to the cylinder block, which varies the duration of the piston stroke during which the vent port is closed.

Sommars, Mark F. (Sparland, IL)

2001-01-01

381

Graphing Points  

NSDL National Science Digital Library

Let's learn how to use the lines on graphs (the x & y axis) to plot information. Choose any of the activities below to test your knowledge of identifying the coordinates correctly. Meteoroid Coordinates Soccer Coordinates Donut Coordinates Graphing Points Save the Zogs!-Using Linear Equations Using your coordinate plane knowledge and linear equations help to rescue the Zogs! Can you find the axis for these problems too? What have you noticed about linear equations? What do the lines in linear equations look ...

Izzy

2012-02-07

382

Standard Reference Materials: Tin Freezing-Point Standard: SRM 741a.  

National Technical Information Service (NTIS)

The freezing point of tin (231.928 degrees C) is a defining fixed point of the International Temperature Scale of 1990 (ITS-90). Realization of this freezing point is performed using a fixed-point cell containing high-purity (> or = 99.9999% pure) tin. A ...

G. F. Strouse N. P. Moiseeva

1999-01-01

383

Comparison of slurry versus fixed-bed reactor costs for indirect liquefaction applications  

SciTech Connect

This work is a comparative evaluation of slurry reactors and fixed-bed reactors, with special emphasis on cost. Relative differences between slurry reactors and fixed-bed reactors have been pointed out in previous reviews; the differences pertinent to indirect liquefaction are summarized here. Design of both types is outlined.

Prakash, A.; Bendale, P.G.

1991-12-01

384

32 CFR 634.46 - Point system procedures.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Point system procedures. 634.46 ...Records and the Traffic Point System § 634.46 Point system procedures. (a...taken (including action by a U.S. Magistrate Court on DD Form 1805),...

2013-07-01

385

40 CFR 280.66 - Corrective action plan.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Corrective action plan. 280.66 Section 280.66...Substances § 280.66 Corrective action plan. (a) At any point after...develop and submit a corrective action plan for responding to...

2013-07-01

386

47 CFR 78.108 - Minimum path lengths for fixed links.  

Code of Federal Regulations, 2012 CFR

...BROADCAST RADIO SERVICES CABLE TELEVISION RELAY SERVICE Technical...distance between end points of a fixed link must equal or exceed the value set forth in the table...the Table in § 74.636 of this part. A =...

2012-10-01

387

47 CFR 78.108 - Minimum path lengths for fixed links.  

Code of Federal Regulations, 2011 CFR

...BROADCAST RADIO SERVICES CABLE TELEVISION RELAY SERVICE Technical...distance between end points of a fixed link must equal or exceed the value set forth in the table...the Table in § 74.636 of this part. A =...

2011-10-01

388

Action Learning.  

ERIC Educational Resources Information Center

|These four papers were presented at a symposium on action learning moderated by Lex Dilworth at the 1996 conference of the Academy of Human Resource Development. "Developing an Infrastructure for Individual and Organizational Change: Transfer of Learning from an Action Reflection Learning (ARL) Program" (ARL Inquiry) reports findings from a study…

1996

389

Co-Channel Interference Analysis of Point to Point mm-Wave Radio Links  

Microsoft Academic Search

Point to point mm-wave radio links are being increasingly deployed because of the expansion of commercial wireless services. Providers of wireless services continue to demand systems with higher data rate and higher carrier frequency. In order to fulfill the demand unlicensed mm-wave bands have been investigated for fixed point-to-point outdoor radio ap- plications. An analytical method is developed in this

Mingdong Xu; Peter Nuechter

2006-01-01

390

Surgical Correction of Fixed Kyphosis  

PubMed Central

Study Design A retrospective review was carried out on 23 patients with rigid fixed kyphosis who underwent surgical correction for their deformity. Purpose To report the results of surgical correction of fixed kyphosis according to the surgical approaches or methods. Overview of Literature Surgical correction of fixed kyphosis is more dangerous than the correction of any other spinal deformity because of the high incidence of paraplegia. Methods There were 12 cases of acute angular kyphosis (6 congenital, 6 healed tuberculosis) and 11 cases of round kyphosis (10 ankylosing spondylitis, 1 Scheuermann's kyphosis). Patients were excluded if their kyphosis was due to active tuberculosis, fractures, or degenerative lumbar changes. Operative procedures consisted of anterior, posterior and combined approaches with or without total vertebrectomy. Anterior procedure only was performed in 2 cases, while posterior procedure only was performed in 8 cases. Combined procedures were used in 13 cases, including 4 total vertebrectomies. Results The average kyphotic angle was 71.8° preoperatively, 31.0° postoperatively, and the average final angle was 39.2°. Thus, the correction rate was 57% and the correction loss rate was 12%. In acute angular kyphosis, correction rate of an anterior procedure only was 71%, correction rate of the combined procedures without total vertebrectomy was 49% and correction rate of the combined procedures with total vertebrectomy was 60%. In round kyphosis, correction rate of posterior procedure only was 65% and correction rate of combined procedures was 59%. The clinical results according to the Kirkaldy-Willis scale demonstrated 17 excellent outcomes, 5 good outcomes and one poor outcome. Conclusions Our data indicates that the combined approach and especially the total vertebrectomy showed the safety and the greatest correction rate if acute angular kyphosis was greater than 60 degrees.

Cho, Woo-Jin; Kang, Chang-Nam; Park, Ye-Soo; Kim, Hyoung-Jin

2007-01-01

391

8.EE Fixing the Furnace  

NSDL National Science Digital Library

This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important asects of the task and its potential use. Here are the first few lines of the commentary for this task: Ivan�s furnace has quit working during the coldest part of the year, and he is eager to get it fixed. He decides to call some mechanics and furnace spe...

392

How to print floating-point numbers accurately  

Microsoft Academic Search

We present algorithms for accurately converting floating-point numbers to decimal representation. The key idea is to carry along with the computation an explicit representation of the required rounding accuracy.We begin with the simpler problem of converting fixed-point fractions. A modification of the well-known algorithm for radix-conversion of fixed-point fractions by multiplication explicitly determines when to terminate the conversion process; a

Guy L. Steele Jr.; Jon L. White

1990-01-01

393

How to print floating-point numbers accurately  

Microsoft Academic Search

We present algorithms for accurately converting floating-point numbers to decimal representation. The key idea is to carry along with the computation an explicit representation of the required rounding accuracy.We begin with the simpler problem of converting fixed-point fractions. A modification of the well-known algorithm for radix-conversion of fixed-point fractions by multiplication explicitly determines when to terminate the conversion process; a

Guy L. Steele Jr; Jon L. White

2004-01-01

394

Point Defects  

NASA Astrophysics Data System (ADS)

Point defects are pervasive. They are present in all materials, as a result of the intrinsic thermodynamic equilibrium and of the inevitable levels of impurities. Indeed, elementary chemical thermodynamics shows that if a defect formation reaction (e.g., Frenkel or Schottky formation as discussed below) is associated with a free energy gD, then the equilibrium mole fraction, xD, of defects is given by: x_D = exp ( { - {g_D }/{{nkT} ), where n is the number of defects created in the defect formation process. The equation shows that xd > 0 for T > 0, and also demonstrates that properties dependent on defects will show "Arrhenius"-like temperature dependence.

Catlow, C. R. A.

395

Geotechnics of Fixed Offshore Drilling Platforms.  

National Technical Information Service (NTIS)

Fixed offshore-structures are widely used for exploration and exploitation of undersea oil and gas resources. The object of this report is to survey the general geotechnical design principles and foundation technics of fixed offshore-structures. Additiona...

J. Toernqvist

1984-01-01

396

Fixed-dose combination therapy in hypertension: cons.  

PubMed

The goal of antihypertensive therapy is to reduce the risk associated with blood pressure elevation. Although the choice of first-line drug therapy may exert some effects on different long-term cardiovascular endpoints, randomized clinical trials and meta-analyses demonstrated that blood pressure reduction per se is the primary determinant in primary and secondary prevention. Numerous analyses carried out over the last years have repeatedly shown that many patients require the combination of two or more drugs to reach the recommended level of blood pressure control. Within this context, combination therapy with separate agents or fixed-dose combination pills offers an attractive ability to lower blood pressure more quickly, decrease adverse effects and reach blood pressure target. It is not clear whether fixed combinations of antihypertensive agents in a single tablet provide a greater benefit than the corresponding components given separately. In other words, it is not clear if the use of fixed combinations translates into a clearly improved blood pressure control and cardiovascular prevention in clinical practice. Fixed-dose combinations may simplify the treatment regimen by reducing the number of pills and may be attractive for many hypertensive patients. However, single-pill (fixed) drug combinations have some disadvantages: (i) branded fixed combinations may be more expensive than equivalent free combinations; (ii) the duration of action of individual components may not be equivalent, and this may not justify a single daily dosing of the combination; and (iii) the use of fixed combinations implies less flexibility in modifying the doses of individual components and the exposure of patients to unnecessary therapy. Moreover, should a patient develop side effects to one component, the entire combination should be discontinued and replaced by free drugs. The following three types of fixed-dose tablets have been recently proposed to give additional flexibility: (i) tablet manufactured so that each of the two drugs is placed at opposite ends of the tablet with a drug-free (inactive) layer placed in between; (ii) tablet with the combination of drugs at each end with the inactive zone in between; and (iii) tablet divided into discrete, separate segments (the two drugs are combined uniformly), which provides benefits for initial close titration and dosage adjustments. Currently, none of the fixed-dose tablets available on the market have these characteristics and, consequently, are unable to be broken to allow sufficient flexibility. PMID:22867089

Angeli, Fabio; Reboldi, Gianpaolo; Mazzotta, Giovanni; Garofoli, Marta; Ramundo, Elisa; Poltronieri, Cristina; Verdecchia, Paolo

2012-06-01

397

Antisymmetric string actions  

NASA Astrophysics Data System (ADS)

An action is presented for the free bosonic string on external flat space in terms of an antisymmetric second-rank string background tensor which is classically equivalent to the Nambu-Goto action. Both action and field equations are entirely described in terms of 2D world-sheet forms, without any reference to a 2D metric tensor background. The analysis of its canonical formulation shows how the quadratic Virasoro constraints are generated in this case and what their connection with the Bianchi identities are. Since in the orthonormal gauge the reduced action coincides with the standard one, it has the same critical dimension D = 26. The existence of an interaction term of a purely geometric structure stemming in the extrinsic curvature is pointed out. Its action and the new string field equations are then derived. This polynomial antisymmetric string action is uniformly generalized in order to describe d < D-dimensional extended objects in D-dimensional flat space. On leave of absence from Departamento de Física, Universidad Simon Bolívar, Apartado 80659, Caracas 1080A, Venezuela.

Aragone, C.

1986-12-01

398

Realization of the Temperature Scale in the Range from 234.3 K (Hg Triple Point) to 1084.62°C (Cu Freezing Point) in Croatia  

NASA Astrophysics Data System (ADS)

This article describes the realization of the International Temperature Scale in the range from 234.3 K (mercury triple point) to 1084.62°C (copper freezing point) at the Laboratory for Process Measurement (LPM), Faculty of Mechanical Engineering and Naval Architecture (FSB), University of Zagreb. The system for the realization of the ITS-90 consists of the sealed fixed-point cells (mercury triple point, water triple point and gallium melting point) and the apparatus designed for the optimal realization of open fixed-point cells which include the gallium melting point, tin freezing point, zinc freezing point, aluminum freezing point, and copper freezing point. The maintenance of the open fixed-point cells is described, including the system for filling the cells with pure argon and for maintaining the pressure during the realization.

Zvizdic, Davor; Veliki, Tomislav; Grgec Bermanec, Lovorka

2008-06-01

399

Relative Critical Points  

NASA Astrophysics Data System (ADS)

Relative equilibria of Lagrangian and Hamiltonian systems with symmetry are critical points of appropriate scalar functions parametrized by the Lie algebra (or its dual) of the symmetry group. Setting aside the structures - symplectic, Poisson, or variational - generating dynamical systems from such functions highlights the common features of their construction and analysis, and supports the construction of analogous functions in non-Hamiltonian settings. If the symmetry group is nonabelian, the functions are invariant only with respect to the isotropy subgroup of the given parameter value. Replacing the parametrized family of functions with a single function on the product manifold and extending the action using the (co)adjoint action on the algebra or its dual yields a fully invariant function. An invariant map can be used to reverse the usual perspective: rather than selecting a parametrized family of functions and finding their critical points, conditions under which functions will be critical on specific orbits, typically distinguished by isotropy class, can be derived. This strategy is illustrated using several well-known mechanical systems - the Lagrange top, the double spherical pendulum, the free rigid body, and the Riemann ellipsoids - and generalizations of these systems.

Lewis, Debra

2013-05-01

400

Action Research  

NSDL National Science Digital Library

Defined as "any systemic inquiry conducted by teachers� for the purpose of gathering information about how their particular schools operate, how they teach, and how their students learn" (Mertler, 2009), action research is empowering and professi

Beran, Becky; Milton-Brkich, Katie L.; Shumbera, Kristen

2010-07-01

401

Mass action  

NSDL National Science Digital Library

In the first part of this video, we derive the law of mass action from one example of a picture of molecular collisions. For this course, we use the "law of mass action" to refer to an idea that chemical reaction kinetic rates can be expressed using products of the abundances of reactants raised to exponents. Studying cooperativity and Hill functions in the second part of the video allows us to investigate a simple example of bistability in the third video segment.

Liao, David

402

Enzyme Action  

NSDL National Science Digital Library

In this activity that can be used as a lab or demonstration, learners use Lactaid® and lactose to demonstrate the concept of enzyme action. Learners test a drop of milk and Lactaid® for the presence of glucose using glucose test paper. Learners also discover the color range of glucose test paper readings. In addition, learners construct paper models to help visualize enzyme action.

Crumlish, Jane

2009-01-01

403

THE USE OF FIXED ANTENNAS FOR DATA COMMUNICATIONS WITH TDRS  

Microsoft Academic Search

The use of the TDRS to provide space-to-ground communications by satellites with fixed-pointed antennas is investigated using simulations and experiments with satellites. The user environment for these techniques is considered to be the low-power, low-data- rate class of satellites typically using proprietary ground stations. The simulation studies found that 3 to 13 contacts per day per TDRS are possible, depending

Stephen Horan

404

Effects of clenbuterol and prenalterol on behavior maintained under a multiple fixed-interval, fixed-ratio schedule.  

PubMed

The results of a number of studies have implicated beta adrenergic receptors in the brain in the actions of proven antidepressant drugs. This suspected involvement of central beta adrenergic receptors made it of interest to characterize the behavioral effects of centrally acting beta adrenergic agonists. Clenbuterol and prenalterol, unlike most beta adrenergic agonists, penetrate into the central nervous system after peripheral administration. In the present study, the effects of these agonists on behavior maintained under a multiple fixed-interval 5-min, fixed-ratio 30-response schedule were determined. Both compounds, in a dose-dependent manner, reduced response rate under both components of the multiple schedule. Under the fixed-interval component, clenbuterol and prenalterol altered the temporal pattern of responding. At no dose tested was there evidence for any stimulant action of either of the drugs. The effects of clenbuterol and prenalterol on behavior maintained under the multiple schedule appeared to be a result of an interaction of the agonists with beta adrenergic receptors. This was evidenced by the ability of the beta adrenergic antagonist propranolol to block the effects of the agonists. The behavioral effects of clenbuterol and prenalterol appear, in general, to be similar to effects reported previously for tricyclic and monoamine oxidase inhibiting antidepressant drugs. PMID:2886645

O'Donnell, J M

1987-08-01

405

Final consolidated action plan to Tiger Team  

SciTech Connect

This document contains the planned actions to correct the deficiences identified in the Tiger Team Assessments of Sandia California (August 1990) and Sandia New Mexico (May 1991). Information is also included on the management structures, estimated costs, root causes, prioritization and schedules for the Action Plan. This Plan is an integration of the two individual Action Plans to provide a cost effective, integrated program for implementation by Sandia and monitoring by DOE. This volume (I) contains the findings and actions concerning the environment. Tables 4.2 and 4.7 summarize the annual costs estimated for completing the actions. The total costs for completion of all the actions are estimated to be $283 million over a 12 year period; the majority of the actions to be completed and costs incurred in the first five years. Resources are provided from DOE-ER/WM, the DOE/DP landlord funds (one time, physical fixes), and from the Sandia Indirect Budget.

Not Available

1992-10-01

406

Analysis of formation of primary radiation-induced point defects in graphite under action of secondary neutrons and ? ? -mesons generated in various channels of nuclear reactions upon graphite irradiation by 450GeV protons  

Microsoft Academic Search

A theoretical model is constructed and the rates of formation are calculated for primary radiation-induced point defects in\\u000a graphite by secondary neutrons and ??-mesons generated in various nuclear reaction channels upon irradiation of graphite by a 450-GeV proton beam. Calculations\\u000a are performed using the ENDF-VII nuclear data base for energies of secondary particles lower than 150 MeV. It is shown

A. I. Ryazanov; E. V. Semenov

2010-01-01

407

A CMOS floating point multiplier  

NASA Astrophysics Data System (ADS)

This paper describes a 32-bit CMOS floating point multiplier. The chip can perform 32-bit floating point multiplication (based on the proposed IEEE Standard format) and 24-bit fixed point multiplication (two's complement format) in less than 78.7 and 71.1 ns, respectively, and the typical power dissipation is 195 mW at 10 million operations per second. High-speed multiplication techniques - a modified Booth's allgorithm, a carry save adder scheme, a high-speed CMOS full adder, and a modified carry select adder - are used to achieve the above high performance. The chip is designed for compatibility with 16-bit microcomputer systems, and is fabricated in 2 micron n-well CMOS technology; it contains about 23000 transistors of 5.75 x 5.67 sq mm in size.

Uya, M.; Kaneko, K.; Yasui, J.

1984-10-01

408

Action, human.  

PubMed

The term "human action" designates the intentional and deliberate movement that is proper and exclusive to mankind. Human action is a unified structure: knowledge, intention or volition, deliberation, decision or choice of means and execution. The integration between these dimensions appears as a task that demands strength of will to achieve the synthesis of self-possession and self-control that enables full personal realisation. Recently, the debate about the dynamism of human action has been enriched by the contribution of neurosciences. Thanks to techniques of neuroimaging, neurosciences have expanded the field of investigation to the nature of volition, to the role of the brain in decision-making processes and to the notion of freedom and responsibility. PMID:20393686

Russo, M T

2010-01-01

409

Conjunctive schedules of reinforcement: III. A fixed-interval adjusting fixed-ratio schedule1  

PubMed Central

Key pecking of three pigeons was studied under a conjunctive schedule that specified both a fixed-interval and an adjusting fixed-ratio requirement. The fixed-interval schedule was 6 min for one pigeon and 3 min for the other two. The size of the ratio requirement was determined within each cycle of the fixed interval by the duration of the pause before responding began. The fixed-ratio value was at maximum at the start of each fixed interval and decreased linearly until the first response occurred (adjusting fixed-ratio schedule). A peck produced food when the number of responses remaining on the fixed-ratio schedule was completed and when the fixed interval had elapsed. If no response occurred during the interval, the fixed-ratio requirement decreased to one and a single response after the interval elapsed produced food. The initial value of the adjusting fixed-ratio schedule was studied over a range of 0 to 900. Increases in the adjusting fixed-ratio schedule to about 300 responses increased both pause duration and running response rate and also modified the pattern of responding from that obtained under the fixed-interval schedule. Higher values of the adjusting fixed ratio generally decreased pause duration and running response rate and also disrupted responding. Interreinforcement time under the conjunctive schedule was increased substantially when the adjusting fixed-ratio size exceeded 300 responses.

Barrett, James E.

1976-01-01

410

Council actions  

NASA Astrophysics Data System (ADS)

The AGU Council and Executive Committee met on May 19, 1987, in Baltimore, Md., during the 1987 AGU Spring Meeting. All Council members except the Foreign Secretary were present. A number of section secretaries, committee chairmen, editors, interested members, and staff also attended. The primary actions of Council are outlined below.

411

High-Throughput Detection of Actionable Genomic Alterations in Clinical Tumor Samples by Targeted, Massively Parallel Sequencing  

PubMed Central

Knowledge of “actionable” somatic genomic alterations present in each tumor (e.g., point mutations, small insertions/deletions, and copy number alterations that direct therapeutic options) should facilitate individualized approaches to cancer treatment. However, clinical implementation of systematic genomic profiling has rarely been achieved beyond limited numbers of oncogene point mutations. To address this challenge, we utilized a targeted, massively parallel sequencing approach to detect tumor genomic alterations in formalin-fixed, paraffin embedded (FFPE) tumor samples. Nearly 400-fold mean sequence coverage was achieved, and single nucleotide sequence variants, small insertions/deletions, and chromosomal copy number alterations were detected simultaneously with high accuracy compared to other methods in clinical use. Putatively actionable genomic alterations, including those that predict sensitivity or resistance to established and experimental therapies, were detected in each tumor sample tested. Thus, targeted deep sequencing of clinical tumor material may enable mutation-driven clinical trials and, ultimately, ”personalized” cancer treatment.

Wagle, Nikhil; Berger, Michael F.; Davis, Matthew J.; Blumenstiel, Brendan; DeFelice, Matthew; Pochanard, Panisa; Ducar, Matthew; Van Hummelen, Paul; MacConaill, Laura E.; Hahn, William C.; Meyerson, Matthew; Gabriel, Stacey B.; Garraway, Levi A.

2011-01-01

412

Rips Complexes of Planar Point Sets  

Microsoft Academic Search

Fix a finite set of points in Euclidean $n$-space $\\\\euc^n$, thought of as a point-cloud sampling of a certain domain $D\\\\subset\\\\euc^n$. The Rips complex is a combinatorial simplicial complex based on proximity of neighbors that serves as an easily-computed but high-dimensional approximation to the homotopy type of $D$. There is a natural ``shadow'' projection map from the Rips complex to

Erin W. Chambers; Vin de Silva; Jeff Erickson; Robert Ghrist

2007-01-01

413

The conformal points of the generalized Thirring model  

Microsoft Academic Search

The conformal fixed points of the generalized Thirring model are investigated with the help of bosonization, the large-N limit and the operator product expansion. Necessary conditions on the coupling constants for conformal invariance are derived.

Korkut Bardakci; Luis M. Bernardo

1994-01-01

414

77 FR 38495 - Safety Zone; Village of Sodus Point Fireworks Display, Sodus Bay, Sodus Point, NY  

Federal Register 2010, 2011, 2012, 2013

...Fireworks Display, Sodus Bay, Sodus Point, NY AGENCY: Coast Guard, DHS. ACTION: Temporary...safety zone on Sodus Bay, Sodus Point, NY. This safety zone is intended to restrict...be held on Sodus Bay near Sodus Point, NY. The Captain of the Port Buffalo has...

2012-06-28

415

ON LYAPUNOV FAMILIES AROUND COLLINEAR LIBRATION POINTS  

SciTech Connect

Evolution details of the planar and vertical Lyapunov families around the three collinear libration points in the restricted three-body problem were studied. Researches before were generally restricted to be within the colliding orbits with the primaries and for fixed mass parameters {mu}. In this paper, members after colliding orbits were computed. With increasing {mu}, how these families evolve was studied.

Hou, X. Y.; Liu, L. [Astronomy Department, Nanjing University, Nanjing 210093 (China)], E-mail: lliu@nju.edu.cn

2009-06-15

416

Fixing the national laboratory system  

SciTech Connect

Over the past 20 years, there have been numerous studies of the Department of Energy (DOE) national laboratories. Having reviewed numerous recommendations of outsiders, the Department of Energy responds with a plan of action. Having reviewed these, we find that there is much merit in the criticisms and much good intention in the proposals to change the governance and focus of the laboratories. But we believe that the proposals either attack the wrong problems or are simply unlikely to succeed. We have developed instead what we believe is a comprehensive and practical strategy to manage the national laboratory system to achieve national goals and to make it once again an essential, cost-effective, and well-managed element of the nation`s R&D enterprise. We believe that this approach, unlike others tried over the past two decades, is demonstrably working and should be continued. This paper outlines these proposals.

Curtis, C.B.; McTague. J.P.; Cheney, D.W.

1997-11-01

417

Simplifying fixed implant dental prosthetics.  

PubMed

Through following the FPPD protocol for multiple adjacent implants, and delivering final abutments, picking up the metal framework, and delivering provisionals, many benefits are gained. The benefits of following the FPPD protocol are as follows: The restorative dentist is trying-in and delivering the final abutments in one visit as opposed to removing them and placing them multiple times. This requires less chair time and time for the patient. It also reduces the mechanical stress on the abutment screw and implant body due to the elimination of multiple try-in appointments. When the metal framework is tried-in and verified for fit, the restorative dentist has the opportunity check the retention, check the margins, and make any corrections that might be needed. The abutments will be staying in the mouth when the framework is picked up. This metal try-in allows for a verification of the bite to be given to the dental lab. The delivery of provisionals manufactured by the dental laboratory offers many advantages in the FPPD technique. The patient has a form of tooth much earlier in the traditional appointment sequence. The patient can now offer feedback to the doctor and laboratory for fabrication of the permanent prosthesis with regards to shape and color. The laboratory-fabricated provisionals offer progressive loading to the implants through having a reduced occlusion yet allowing food to stimulate the implants. Overall, the FPPD technique offers shorter appointment times, more rapid delivery of fixed supported teeth, improved doctor-technician communication, and less mechanical wear on the implant parts. PMID:21306074

Tischler, Michael

2011-01-01

418

"Hedgehog Point" feature point matching based on point structure information  

NASA Astrophysics Data System (ADS)

Based on points structure information, this paper presents a new method called "hedgehog point" matching, a fast algorithm for point pattern matching is proposed to effectively solve the problems of optimal matches between two point pattern under geometrical transformation and correctly identify the missing or spurious points of patterns. Theorems and algorithms are developed to determine the matching pairs support of each point pair and its transformation parameters (scaling S and rotation ?) on a two-parameter space (S, ?). Experiments are conducted both on real and synthetic data. The experimental results show that the proposed matching algorithm can handle translation, rotation, and scaling differences under noisy or distorted condition.

Xu, Yi-Dan; Zhu, Xian-Wei; Yu, Qi-Feng

2009-07-01

419

Evolutionary quantum cosmology in a gauge-fixed picture  

SciTech Connect

We study the classical and quantum models of a flat Friedmann-Robertson-Walker space-time, coupled to a perfect fluid, in the context of the consensus and a gauge-fixed Lagrangian frameworks. It is shown that, either in the usual or in the gauge-fixed actions, the evolution of the Universe based on the classical cosmology represents a late time power law expansion, coming from a big-bang singularity in which the scale factor goes to zero for the standard matter, and tending towards a big-rip singularity in which the scale factor diverges for the phantom fluid. We then employ the familiar canonical quantization procedure in the given cosmological setting to find the cosmological wave functions in the corresponding minisuperspace. Using a gauge-fixed (reduced) Lagrangian, we show that it may lead to a Schroedinger equation for the quantum-mechanical description of the model under consideration, the eigenfunctions of which can be used to construct the time dependent wave function of the Universe. We use the resulting wave function in order to investigate the possibility of the avoidance of classical singularities due to quantum effects by means of the many-worlds and ontological interpretation of quantum cosmology.

Vakili, Babak [Department of Physics, Islamic Azad University (IAU), Chalous Branch, P. O. Box 46615-397, Chalous (Iran, Islamic Republic of)

2011-05-15

420

Extraction, Fixed Costs and the Hotelling Rule.  

National Technical Information Service (NTIS)

Starting from the matter of fact that in the extracting industry large-scale investments and fixed costs play an important role the influence of fixed extraction costs and a convex curve on the time path of extraction is investigated. Moreover the time pa...

H. Siebert

1981-01-01

421

Statistical analysis of fixed income market  

NASA Astrophysics Data System (ADS)

We present cross and time series analysis of price fluctuations in the US Treasury fixed income market. Bonds have been classified according to a suitable metric based on the correlation among them. The classification shows how the correlation among fixed income securities depends strongly on their maturity. We study also the structure of price fluctuations for single time series.

Bernaschi, Massimo; Grilli, Luca; Vergni, Davide

2002-05-01

422

Digital Design of Fixed Bridge Framework  

Microsoft Academic Search

The fixed bridge framework is an important part of prosthodontics. We design a fixed bridge framework in computer with our own original dental CAD software. The 3D data of the abutment teeth is measured by ATOS II 3D scanner. Then the coping crowns are designed based on the implicit surfaces. An algorithm is presented to deform the bridge based on

An Tao; Dai Ning; Cheng Xiaosheng; Lu Peijun; Wang Yong

2008-01-01

423

Automatically fixing security vulnerabilities in Java code  

Microsoft Academic Search

Most kinds of security vulnerabilities in web applications can be fixed by adding appropriate sanitization methods. Finding the correct place for the sanitizers can be difficult due to complicated data and control flow. Fixing SQL injection vulnerabilities may require more complex transformations, such as replacing uses of Statement by PreparedStatement, which could include some code motion. We have developed algorithms

Aharon Abadi; Ran Ettinger; Yishai A. Feldman; Mati Shomrat

2011-01-01

424

Understanding the Point of Chimpanzee Pointing  

PubMed Central

Pointing has long been considered to be a uniquely human, universal, and biologically based gesture. However, pointing emerges spontaneously, without explicit training, in captive chimpanzees. Because pointing is commonplace in captive chimpanzees and virtually absent in wild chimpanzees, and because both captive and wild chimpanzees are sampled from the same gene pool, pointing by captive apes is attributable to environmental influences on communicative development. If pointing by captive chimpanzees is so variably expressed in different rearing environments, this suggests that pointing by humans may also be attributable to situational factors that make pointing effective in certain developmental contexts.

Leavens, David A.; Hopkins, William D.; Bard, Kim A.

2007-01-01

425

Effects of nonperturbatively improved dynamical fermions in QCD at fixed lattice spacing  

Microsoft Academic Search

We present results for the static interquark potential, lightest glueballs, light hadron spectrum, and topological susceptibility using a nonperturbatively improved action on a 163×32 lattice at a set of values of the bare gauge coupling and bare dynamical quark mass chosen to keep the lattice size fixed in physical units (~1.7 fm). By comparing these measurements with a matched quenched

C. R. Allton; S. P. Booth; K. C. Bowler; J. Garden; A. Hart; D. Hepburn; A. C. Irving; B. Joó; R. D. Kenway; C. M. Maynard; C. McNeile; C. Michael; S. M. Pickles; J. C. Sexton; K. J. Sharkey; Z. Sroczynski; M. Talevi; M. Teper; H. Wittig

2002-01-01

426

Point Set Registration: Coherent Point Drift  

Microsoft Academic Search

Point set registration is a key component in many computer vision tasks. The\\u000agoal of point set registration is to assign correspondences between two sets of\\u000apoints and to recover the transformation that maps one point set to the other.\\u000aMultiple factors, including an unknown non-rigid spatial transformation, large\\u000adimensionality of point set, noise and outliers, make the point set

Andriy Myronenko; Xubo B. Song

2010-01-01

427

Action Learning: Avoiding Conflict or Enabling Action  

ERIC Educational Resources Information Center

|Action learning is based on the premise that action and learning are inextricably entwined and it is this potential, to enable action, which has contributed to the growth of action learning within education and management development programmes. However has this growth in action learning lead to an evolution or a dilution of Revan's classical…

Corley, Aileen; Thorne, Ann

2006-01-01

428

A Worked Function Point model for effective software project size evaluation  

Microsoft Academic Search

This work explains the Worked Function Point model for effective software project size evaluation. This model was originally proposed in a contractual framework of fixed cost per function point, in order to achieve a more significant \\

Luca Santillo; Italo Della Noce

429

Instant Attraction: Immediate Action-Effect Bindings Occur for Both, Stimulus- and Goal-Driven Actions  

PubMed Central

Flexible behavior is only possible if contingencies between own actions and following environmental effects are acquired as quickly as possible; and recent findings indeed point toward an immediate formation of action-effect bindings already after a single coupling of an action and its effect. The present study explored whether these short-term bindings occur for both, stimulus- and goal-driven actions (“forced-choice actions” vs. “free-choice actions”). Two experiments confirmed that immediate action-effect bindings are formed for both types of actions and affect upcoming behavior. These findings support the view that action-effect binding is a ubiquitous phenomenon which occurs for any type of action.

Janczyk, Markus; Heinemann, Alexander; Pfister, Roland

2012-01-01

430

Holography in action  

SciTech Connect

The Einstein-Hilbert action and its natural generalizations to higher dimensions (like the Lanczos-Lovelock action) have certain peculiar features. All of them can be separated into a bulk and a surface term, with a specific (''holographic'') relationship between the two, so that either term can be used to extract information about the other. Further, the surface term leads to entropy of the horizons on shell. It has been argued in the past that these features are impossible to understand in the conventional approach but find a natural explanation if we consider gravity as an emergent phenomenon. We provide further support for this point of view in this paper. We describe an alternative decomposition of the Einstein-Hilbert action and the Lanczos-Lovelock action into a new pair of surface and bulk terms, such that the surface term becomes the Wald entropy on a horizon and the bulk term is the energy density (which is the Arnowitt-Deser-Misner Hamiltonian density for Einstein gravity). We show that this new pair also obeys a holographic relationship, and we give a thermodynamic interpretation of this relation in this context. Since the bulk and surface terms, in this decomposition, are related to the energy and entropy, the holographic condition can be thought of as analogous to inverting the expression for entropy given as a function of energy S=S(E,V) to obtain the energy E=E(S,V) in terms of the entropy in a normal thermodynamic system. Thus the holographic nature of the action allows us to relate the descriptions of the same system in terms of two different thermodynamic potentials. Some further possible generalizations and implications are discussed.

Kolekar, Sanved; Padmanabhan, T. [IUCAA, Post Bag 4, Ganeshkhind, Pune 411 007 (India)

2010-07-15

431

Fixed target issues for the Tevatron Upgrade  

SciTech Connect

The Tevatron Upgrade poses some interesting prospects for the Fixed-Target program if an option to extract the high energy proton beam is preserved. This paper presents a summary of the advantages of increased energy for fixed target experiments, and evaluates some of the more challenging technical issues. In particular, Bottom production, muon and neutrino interactions, and polarized /bar p/ experiments would benefit substantially from a higher energy primary beam. The new Main Injector will also be important for fixed target experiments as a source for test beams and intense kaon and neutrino beams. 4 refs., 2 tabs.

Stefanski, R.

1988-08-29

432

The 1994 Fermilab Fixed Target Program  

SciTech Connect

This paper highlights the results of the Fermilab Fixed Target Program that were announced between October, 1993 and October, 1994. These results are drawn from 18 experiments that took data in the 1985, 1987 and 1990/91 fixed target running periods. For this discussion, the Fermilab Fixed Target Program is divided into 5 major topics: hadron structure, precision electroweak measurements, heavy quark production, polarization and magnetic moments, and searches for new phenomena. However, it should be noted that most experiments span several subtopics. Also, measurements within each subtopic often affect the results in other subtopics. For example, parton distributions from hadron structure measurements are used in the studies of heavy quark production.

Conrad, J. [Fermi National Accelerator Lab., Batavia, IL (United States)]|[Columbia Univ., New York, NY (United States)

1994-11-01

433

Bipolar versus fixed-head hip arthroplasty for femoral neck fractures in elderly patients.  

PubMed

Between 2002 and 2007, fifty elderly patients with displaced femoral neck fractures were treated with hip replacement at Emergency Hospital, Mansoura University. Patients were randomly selected, 25 patients had either cemented or cementless bipolar prosthesis, and another 25 patients had either cemented or cementless fixed-head prosthesis. There were 34 women and 16 men with an average age of 63.5 years (range between 55 and 72 years). All patients were followed up both clinically and radiologically for an average 4.4 years (range between 2 and 6 years). At the final follow-up, the average Harris hip score among the bipolar group was 92 points (range between 72 and 97 points), while the fixed-head group was 84 points (range between 65 and 95 points). Radiologically, joint space narrowing more than 2 mm was found in only 8% (2 patients) among the bipolar group, and in 28% (7 patients) of the fixed-head group. Through the follow-up period, total hip replacement was needed in two cases of the bipolar group and seven cases of the fixed-head group. Bipolar hemiarthroplasty offered a better range of movement with less pain and more stability than the fixed-head hemiarthroplasty in elderly patients with displaced femoral neck fractures. PMID:21589675

Abdelkhalek, Mostafa; Abdelwahab, Mohamed; Ali, Ayman M

2011-01-22

434

Exposure Measurement Action Level and Occupational Environmental Variability.  

National Technical Information Service (NTIS)

The proposed Occupational Safety and Health Administration Health Standards define an exposure measurement action level as one half of the current permissible exposure limits. The action level is the point at which certain provisions of the proposed stand...

N. A. Leidel K. A. Busch W. E. Crouse

1975-01-01

435

N = 4 SYM low-energy effective action in N = 4 harmonic superspace  

NASA Astrophysics Data System (ADS)

We apply the N = 4 harmonic superspace with USp(4) harmonic variables for describing the N = 4 SYM low-energy effective action. Scale invariance and gauge symmetry fix the leading term in the low-energy effective action uniquely, up to a constant. The value of the remaining constant can be fixed by the topological quantization condition for the Wess-Zumino term which is present in the component structure of this action.

Samsonov, I. B.

2012-09-01

436

Applications of fixed-time flow cytometry in cell biology  

NASA Astrophysics Data System (ADS)

Flow cytometric (FCM) measurement of intracellular free calcium [Ca2+]i, transients is usually done by two methods: (a) after a short prerun period to assess the baseline the measurement is stopped, stimulus is added and the measurement continued or (b) stimulus is injected during measurement and the sample pressure briefly increased to deliver cells rapidly to the detection point. In (a) measurement of very short transients [Ca2+]i is impeded by the lag time between stimulus addition and restart of acquisition. In (b) response of pressure sensitive cells is hard to analyze. Furthermore, (a) and (b) do not allow to quantify and sort rare responders. A simple Fixed- Time device has been developed. Ca2+ sensitive fluorescent dye labeled cells and a stimulus are placed in different vials. Both fluids are forced by the same pressure through tubing that merges into a T-junction where they mix and are delivered through a connecting tube to the FCM: [Ca2+]i is measured at a certain time after stimulation that is adjusted by sample flow rate and length of the connecting tube. With Fixed-Time, the pressure sensitive neuronal NH15-CA2 cell was analyzed. Furthermore, rare neurotransmitter responsive fibroblast from normal and transfected cultures were sorted and cloned and their dose response characterized. The results demonstrate that fixed- time FCM is an important tool for the analysis of the cells physiology and the preparation of responders.

Tarnok, Atilla

1998-04-01

437

Flight demonstration of image fix-taking with SAR  

NASA Astrophysics Data System (ADS)

Airborne synthetic aperture radar (SAR) uses coherent radar processing techniques to image ground reflectors. After processing, range and Doppler can be associated with any feature of interest in the final image. The location of any imaged feature can be estimated using a Kalman filter to combine these data with GPS and INS navigation data. This paper reports on the results of a flight demonstration of such a system, using an airborne SAR developed at Sandia. Collected data consisted of multiple SAR images containing surveyed reflectors, GPS/INS output taken aboard the aircraft, and GPS output recorded at surveyed ground stations. These data were post-processed at Sandia and at Draper Laboratory to obtain a navigation solution based on differential GPS and to demonstrate SAR fix-taking performance. This study successfully demonstrates accuracy of about one meter for fixing the position of a point imaged with SAR from an airborne platform. Because differential GPS was used, the navigation error was of about the same magnitude as the SAR range measurement error. Consequently, the measurements served primarily to fix the SAR image rather than to update the navigator.

Gibbs, Richard; Bottkol, Matthew; Owen, Todd

1993-06-01

438

Fluconazole-induced Fixed Drug Eruption.  

PubMed

Triazole antifungals are commonly used in the treatment of oral, esophageal, and vaginal candidiasis. Fluconazole is frequently prescribed as the therapy modality for vaginal fungal infections. On rare occasions, fluconazole has been shown to cause fixed drug eruptions. Lesions of fixed drug eruptions vary in size and number, but have the same general appearance and symptoms. The authors report a case of fluconazole-induced fixed drug eruption in a 24-year-old woman with recurrent vaginal candidiasis. The lesion was initially diagnosed as a spider bite. Topical and oral provocation tests with fluconazole were performed. Topical provocation with petroleum/fluconazole and dimethyl sulfoxide/fluonazole were both negative. Oral provocation was positive, thus confirming the diagnosis of fluconazole-induced fixed drug eruption. PMID:23556037

Gaiser, Cory Allen; Sabatino, Dominick

2013-03-01

439

Fluconazole-induced Fixed Drug Eruption  

PubMed Central

Triazole antifungals are commonly used in the treatment of oral, esophageal, and vaginal candidiasis. Fluconazole is frequently prescribed as the therapy modality for vaginal fungal infections. On rare occasions, fluconazole has been shown to cause fixed drug eruptions. Lesions of fixed drug eruptions vary in size and number, but have the same general appearance and symptoms. The authors report a case of fluconazole-induced fixed drug eruption in a 24-year-old woman with recurrent vaginal candidiasis. The lesion was initially diagnosed as a spider bite. Topical and oral provocation tests with fluconazole were performed. Topical provocation with petroleum/fluconazole and dimethyl sulfoxide/fluonazole were both negative. Oral provocation was positive, thus confirming the diagnosis of fluconazole-induced fixed drug eruption.

Sabatino, Dominick

2013-01-01

440

Coagulation Factor IX (Recombinant) (BeneFIX)  

Center for Biologics Evaluation and Research (CBER)

... According to its FDA-approved professional labeling (PI), BeneFIX is a purified protein produced by recombinant DNA technology and is indicated ... More results from www.fda.gov/biologicsbloodvaccines/guidancecomplianceregulatoryinformation/complianceactivities

441

Fixed-Dried Red Blood Cells.  

National Technical Information Service (NTIS)

Fixed-dried red blood cells (RBCs), and processes for preparing the same are disclosed. The red blood cells, upon reconstitution with distilled water or appropriate buffer: bind oxygen with native affinities, have partial deformability, present minimal th...

A. P. Bode M. S. Read T. C. Nichols T. H. Fischer

2005-01-01

442

Four-point amplitude from open superstring field theory  

Microsoft Academic Search

An open superstring field theory action has been proposed which does not suffer from contact term divergences. In this paper, we compute the on-shell four-point tree amplitude from this action using the Giddings map. After including contributions from the quartic term in the action, the resulting amplitude agrees with the first-quantized prescription.

Nathan Berkovits; Carlos Tello Echevarria

2000-01-01

443

Metal release from simulated fixed orthodontic appliances  

Microsoft Academic Search

Most orthodontic appliances and archwires are stainless steel or nickel-titanium (NiTi) alloys that can release metal ions, with saliva as the medium. To measure metal released from the fixed orthodontic appliances currently in use, we fabricated simulated fixed orthodontic appliances that corresponded to half of the maxillary arch and soaked them in 50 mL of artificial saliva (pH 6.75 ±

Chung-Ju Hwang; Ji-Soo Shin; Jung-Yul Cha

2001-01-01

444

Indexing Objects Moving on Fixed Networks  

Microsoft Academic Search

The development of a spatiotemporal access method suitable for ob- jects moving on fixed networks is a very attractive challenge due to the great number of real-world spatiotemporal database applications and fleet manage- ment systems dealing with this type of objects. In this work, a new indexing technique, named Fixed Network R-Tree (FNR-Tree), is proposed for objects constrained to move

Elias Frentzos

2003-01-01

445

Biohydrogen production with fixed-bed bioreactors  

Microsoft Academic Search

An investigation on anaerobic hydrogen production was conducted in fixed-bed bioreactors containing hydrogen-producing bacteria originated from domestic sewage sludge. Three porous materials, loofah sponge (LS), expanded clay (EC) and activated carbon (AC), were used as the support matrix to allow retention of the hydrogen-producing bacteria within the fixed-bed bioreactors. The carriers were assessed for their effectiveness in biofilm formation and

Jo-Shu Chang; Kuo-Shing Lee; Pin-Jei Lin

2002-01-01

446

9 CFR 417.3 - Corrective actions.  

Code of Federal Regulations, 2013 CFR

...ACT AND THE POULTRY PRODUCTS INSPECTION ACT HAZARD ANALYSIS AND CRITICAL CONTROL POINT (HACCP) SYSTEMS § 417.3 Corrective...action to be followed in response to a deviation from a critical limit. The HACCP plan shall describe the...

2013-01-01

447

Vietoris-Rips Complexes of Planar Point Sets  

Microsoft Academic Search

Fix a finite set of points in Euclidean n-space En, thought of as a point-cloud sampling of a certain domain DEn. The Vietoris- Rips complex is a combinatorial simplicial complex based on proximity of neighbors that serves as an easily-computed but high-dimensional ap- proximation to the homotopy type of D. There is a natural \\

Erin W. Chambers; Vin de Silva; Jeff Erickson; Robert Ghrist

2010-01-01

448

Step-down maximum power point tracker for photovoltaic systems  

Microsoft Academic Search

A design of a simple, inexpensive, and efficient maximum power point tracker (MPPT) is presented. This design calls for a fixed voltage and a pilot cell to track the maximum power point voltage (V{sub mp}). The tracking is done by changing the duty cycle of a step-down chopper, which is controlled by a direct feedback analog circuit. The control voltage

Z. M. Salameh; F. Dagher; W. A. Lynch

1991-01-01

449

Practical extensions of point labeling in the slider model  

Microsoft Academic Search

This paper extends on research by the authors together with Alexan- der Wolff on point label placement using a model where labels can be placed at any position that touches the point (the slider model). Such models have been shown to perform better than methods that allow only a fixed number of positions per label. The novelties in this paper

Tycho Strijk; Marc J. van Kreveld

1999-01-01

450

Situated action in the development of activity  

Microsoft Academic Search

After briefly attempting to describe situated action and distributed cogni- tion, we examine their contributions from the point of view of activity theories and more specifically based on the relations between the functio- ning and development of activity. We argue that situated action identifies a limit in cognitive psychology in seeking to bring the subject back into the situation and

Pascal Béguin; Yves Clot

451

Affirmative Action Is an International Issue  

ERIC Educational Resources Information Center

|This article contains comments on the article by Vasquez and Jones (see record 2006-01690-003), which focuses on diversity and begins with a discussion of affirmative action. The current author discusses his own three related points: first, it is virtually impossible, in our current culture, to agree on what constitutes affirmative action and…

Pipes, Randolph B.

2007-01-01

452

Diesel Particulate Oxidation Model: Combined Effects of Volatiles and Fixed Carbon Combustion  

SciTech Connect

Diesel particulate samples were collected from a light duty engine operated at a single speed-load point with a range of biodiesel and conventional fuel blends. The oxidation reactivity of the samples was characterized in a laboratory reactor, and BET surface area measurements were made at several points during oxidation of the fixed carbon component of both types of particulate. The fixed carbon component of biodiesel particulate has a significantly higher surface area for the initial stages of oxidation, but the surface areas for the two particulates become similar as fixed carbon oxidation proceeds beyond 40%. When fixed carbon oxidation rates are normalized to total surface area, it is possible to describe the oxidation rates of the fixed carbon portion of both types of particulates with a single set of Arrhenius parameters. The measured surface area evolution during particle oxidation was found to be inconsistent with shrinking sphere oxidation. When the oxidation model for the fixed carbon was combined with a first-order model for the release and oxidation of volatiles, it was possible to obtain good agreement with the observed oxidation rates for both types of nascent (non-devolatilized) particulates. Additional studies are underway to confirm that intermediate fuel blends behave consistently with these limiting cases.

Strzelec, Andrea [ORNL; Toops, Todd J [ORNL; Daw, C Stuart [ORNL; Foster, Prof. Dave [University of Wisconsin; Rutland, Prof. Christopher J. [University of Wisconsin

2010-01-01

453

Predicting others' actions: evidence for a constant time delay in action simulation.  

PubMed

Recent evidence indicates that humans can precisely predict the outcome of occluded actions. It has been suggested that these predictions arise from a mental simulation which might run in real-time. The present experiments aimed to specify the time course of this simulation process. Participants watched transiently occluded point-light actions and the temporal outcome after occlusion was manipulated. Participants were instructed to judge the temporal coherence of the action after a short (Experiment 1) and a long occlusion period (Experiment 2). Both experiments revealed a comparable negative point of subjective equality (PSE), indicating that action simulation took constantly longer than the observed action itself. Such a temporal error was not present when inverted actions were used, (Experiment 3) ruling out a pure visually driven effect. The results suggest that the temporal error is due to costs arising from a switch from action perception to an internal simulation process involving motor representations. PMID:21365343

Sparenberg, Peggy; Springer, Anne; Prinz, Wolfgang

2011-03-02

454

A comparison of carbide fracture during fixed depth and fixed load scratch tests  

SciTech Connect

In order to simulate abrasion of dual-phase materials containing large carbides under fixed depth conditions an apparatus has been designed and used to perform scratch tests at a fixed depth of cut on such materials. The scratch test consists of two support arms tipped with small steel balls held in contact with surface by /sup 700/ g, while the scratch tool is mounted on the tip of a central arm whose adjustable length allow control of the depth of cut. The scratch tool does not deflect significant when it encounters a large carbide. Scratch tests with the new apparatus have been performed on Co-base Stellite alloys containing large Cr-rich carbides, using individual particles of alumina as scratch tools to generate fixed depth scratches. A in situ SEM scratch test apparatus has also been used to genrate fixed load scratches. Comparison of the scratches shows that for comparable average scratch depths, under fixed load conditions the scratch tool deflects over the carbides without causing fracture, but that since it cannot deflect under fixed depth conditions it induces gross carbide fracture. Results suggest that the fixed depth scratch test can be successfully employed to simulate fixed depth abrasion, which has been previously shown to generate gross carbide fracture in these alloys. The in situ SEM scratch test simulates fixed load abrasion conditions such as those which occur in rubber wheel abrasion tests. 12 refs., 9 figs

Prasad, S.V.; Kosel, T.H.

1985-01-01